Sample records for horizontally polarized brightness

  1. IRTM brightness temperature maps of the Martian south polar region during the polar night: The cold spots don't move

    NASA Technical Reports Server (NTRS)

    Paige, D. A.; Crisp, D.; Santee, M. L.; Richardson, M. I.

    1993-01-01

    A series of infrared thermal mapper (IRTM) south polar brightness temperature maps obtained by Viking Orbiter 2 during a 35-day period during the southern fall season in 1978 was examined. The maps show a number of phenomena that have been identified in previous studies, including day to day brightness temperature variations in individual low temperature regions and the tendency for IRTM 11-micron channel brightness temperatures to also decrease in regions where low 20-micron channel brightness temperatures are observed. The maps also show new phenomena, the most striking of which is a clear tendency for the low brightness temperature regions to occur at fixed geographic regions. During this season, the coldest low brightness temperatures appear to be concentrated in distinct regions, with spatial scales ranging from 50 to 300 km. There are approximately a dozen of these concentrations, with the largest centered near the location of the south residual polar cap. Other concentrations are located at Cavi Angusti and close to the craters Main, South, Lau, and Dana. Broader, less intense regions appear to be well correlated with the boundaries of the south polar layered deposits and the Mountains of Mitchell. No evidence for horizontal motion of any of these regions has been detected.

  2. Long-delayed bright dancing sprite with large Horizontal displacement from its parent flash

    NASA Astrophysics Data System (ADS)

    Yang, Jing; Lu, Gaopeng; Lee, Li-Jou; Feng, Guili

    2015-07-01

    We reported in this paper the observation of a very bright long-delayed dancing sprite with distinct horizontal displacement from its parent stroke. The dancing sprite lasted only 60 ms, and the morphology consisted of three fields with two slim dim sprite elements in the first two fields and a very bright large element in the third field, different from other observations where the dancing sprites usually contained multiple elements over a longer time interval, and the sprite shape and brightness in the video field are often similar to the previous fields. The bright sprite was displaced at least 38 km from its parent cloud-to-ground (CG) stroke and occurred over comparatively higher cloud top region. The parent flash of this compact dancing sprite was of positive polarity, with only one return stroke (approximately +24 kA) and obvious continuing current process, and the charge moment change of stroke was small (barely above the threshold for sprite production). All the sprite elements occurred during the continuing current stage, and the bright long-delayed sprite element induced a considerable current pulse. The dancing feature of this sprite may be linked to the electrical charge structure, dynamics and microphysics of parent storm, and the inferred development of parent CG flash was consistent with previous very high-frequency (VHF) observations of lightning in the same region.

  3. Polarization signatures and brightness temperatures caused by horizontally oriented snow particles at microwave bands: Effects of atmospheric absorption

    NASA Astrophysics Data System (ADS)

    Xie, Xinxin; Crewell, Susanne; Löhnert, Ulrich; Simmer, Clemens; Miao, Jungang

    2015-06-01

    This study analyzes the effects of atmospheric absorption and emission on the polarization difference (PD) and brightness temperature (TB) generated by horizontally oriented snow particles. A three-layer plane-parallel atmosphere model is used in conjunction with a simplified radiative transfer (RT) scheme to illustrate the combined effects of dichroic and nondichroic media on microwave signatures observed by ground-based and spaceborne sensors. Based on idealized scenarios which encompass a dichroic snow layer and adjacent nondichroic layers composed of supercooled liquid water (SCLW) droplets and water vapor, we demonstrate that the presence of atmospheric absorption/emission enhances TB and damps PD when observed from the ground. From a spaceborne perspective, however, TB can be reduced or enhanced by an absorbing/emitting layer above the snow layer, while a strong absorbing/emitting layer below the dichroic snow layer may even enhance PD. The induced PD and TB, which rely on snow microphysical assumptions, can vary up to 2 K and 10 K, respectively, due to the temperature-dependent absorption of SCLW. RT calculations based on 223 snowfall profiles selected from European Centre for Medium-Range Weather Forecasts data sets indicate that the existence of SCLW has a noticeable impact on PD and TB at three window frequencies (150 GHz, 243 GHz, and 664 GHz) during snowfall. Our results imply that while polarimetric channels at the three window channels have the potential for snowfall characterization, accurate information on liquid water is required to correctly interpret the polarimetric observations.

  4. [Study of the electrical properties of retinal horizontal cell syncytia by the technic of uniform polarization].

    PubMed

    Shura-Bura, T M; Trifonov, Iu A

    1980-01-01

    For uniform polarization of syncytial or cable structures at a large area with current passed via extracellular electrodes the extracellular longitudinal gradient of potential must be proportional to distance from the edge of preparation. In this paper the profile of conducting plate was found analytically which allows to obtain such a distribution of potentials. The profile is formed by hyperbola and its orthogonal asymptotes. Two polarizing electrodes are applied to places where the hyperbola is near to asymptotes. On the surfaces formed by asymptotes the gradient of potential is proportional to distance from intersection of these surfaces. Such a conducting plate was made as cavity in plexiglas filled by Ringer solution in agar. The plate was used for obtaining the voltage-current curves of horizontal cell membrane in gold fish retina. The area of uniform polarization was 4-5 mm long. Measurements inside this area allowed to determine the space constant of horizontal cell layer. The space constant measured in bright light (when resistance of subsynaptic membrane is high) depends on the membrane potential, being high (approximately 1,5 mm) during depolarization and low (0,2-0,4 mm) during hyperpolarization.

  5. Experimental generation of tripartite polarization entangled states of bright optical beams

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, Liang; Liu, Yanhong; Deng, Ruijie

    The multipartite polarization entangled states of bright optical beams directly associating with the spin states of atomic ensembles are one of the essential resources in the future quantum information networks, which can be conveniently utilized to transfer and convert quantum states across a network composed of many atomic nodes. In this letter, we present the experimental demonstration of tripartite polarization entanglement described by Stokes operators of optical field. The tripartite entangled states of light at the frequency resonant with D1 line of Rubidium atoms are transformed into the continuous variable polarization entanglement among three bright optical beams via an opticalmore » beam splitter network. The obtained entanglement is confirmed by the extended criterion for polarization entanglement of multipartite quantized optical modes.« less

  6. Polarotactic tabanids find striped patterns with brightness and/or polarization modulation least attractive: an advantage of zebra stripes.

    PubMed

    Egri, Adám; Blahó, Miklós; Kriska, György; Farkas, Róbert; Gyurkovszky, Mónika; Akesson, Susanne; Horváth, Gábor

    2012-03-01

    The characteristic striped appearance of zebras has provoked much speculation about its function and why the pattern has evolved, but experimental evidence is scarce. Here, we demonstrate that a zebra-striped horse model attracts far fewer horseflies (tabanids) than either homogeneous black, brown, grey or white equivalents. Such biting flies are prevalent across Africa and have considerable fitness impact on potential mammalian hosts. Besides brightness, one of the likely mechanisms underlying this protection is the polarization of reflected light from the host animal. We show that the attractiveness of striped patterns to tabanids is also reduced if only polarization modulations (parallel stripes with alternating orthogonal directions of polarization) occur in horizontal or vertical homogeneous grey surfaces. Tabanids have been shown to respond strongly to linearly polarized light, and we demonstrate here that the light and dark stripes of a zebra's coat reflect very different polarizations of light in a way that disrupts the attractiveness to tabanids. We show that the attractiveness to tabanids decreases with decreasing stripe width, and that stripes below a certain size are effective in not attracting tabanids. Further, we demonstrate that the stripe widths of zebra coats fall in a range where the striped pattern is most disruptive to tabanids. The striped coat patterns of several other large mammals may also function in reducing exposure to tabanids by similar mechanisms of differential brightness and polarization of reflected light. This work provides an experimentally supported explanation for the underlying mechanism leading to the selective advantage of a black-and-white striped coat pattern.

  7. Skylab experiment SO73: Gegenschein/zodiacal light. [electrophotometry of surface brightness and polarization

    NASA Technical Reports Server (NTRS)

    Weinberg, J. L.

    1976-01-01

    A 10 color photoelectric polarimeter was used to measure the surface brightness and polarization associated with zodiacal light, background starlight, and spacecraft corona during each of the Skylab missions. Fixed position and sky scanning observations were obtained during Skylab missions SL-2 and SL-3 at 10 wavelenghts between 4000A and 8200A. Initial results from the fixed-position data are presented on the spacecraft corona and on the polarized brightness of the zodiacal light. Included among the fixed position regions that were observed are the north celestial pole, south ecliptic pole, two regions near the north galactic pole, and 90 deg from the sun in the ecliptic. The polarized brightness of the zodiacal light was found to have the color of the sun at each of these positions. Because previous observations found the total brightness to have the color of the sun from the near ultraviolet out to 2.4 micrometers, the degree of polarization of the zodiacal light is independent of wavelength from 4000A to 8200A.

  8. Long-delayed bright dancing sprite with large horizontal displacement from its parent flash

    NASA Astrophysics Data System (ADS)

    Yang, J.; Lu, G.; Lee, L. J.; Feng, G.

    2015-12-01

    A long-delayed very bright dancing sprite with large horizontal displacement from its parent flash was observed. The dancing sprite lasted only 60 ms, and the morphology consisted of three fields with two slim dim sprite elements in the first two fields and a very bright large sprite element in the third field, different from other observations. The bright sprite displaced at least 38 km from its parent flash and occurred over comparatively higher cloud top region. The parent flash was positive, with only one return stroke (~24 kA) and obvious continuing current process, and the charge moment change of the stroke was small (roughly the threshold for sprite production). All of the sprite elements occurred during the continuing current period, and the bright sprite induced considerable current. The sprite dancing features may be linked to parent storm electrical structure, dynamics and microphysics, and the parent CG discharge process which was consistent with VHF observations.

  9. A technique for measuring vertically and horizontally polarized microwave brightness temperatures using electronic polarization-basis rotation

    NASA Technical Reports Server (NTRS)

    Gasiewski, Albin J.

    1992-01-01

    This technique for electronically rotating the polarization basis of an orthogonal-linear polarization radiometer is based on the measurement of the first three feedhorn Stokes parameters, along with the subsequent transformation of this measured Stokes vector into a rotated coordinate frame. The technique requires an accurate measurement of the cross-correlation between the two orthogonal feedhorn modes, for which an innovative polarized calibration load was developed. The experimental portion of this investigation consisted of a proof of concept demonstration of the technique of electronic polarization basis rotation (EPBR) using a ground based 90-GHz dual orthogonal-linear polarization radiometer. Practical calibration algorithms for ground-, aircraft-, and space-based instruments were identified and tested. The theoretical effort consisted of radiative transfer modeling using the planar-stratified numerical model described in Gasiewski and Staelin (1990).

  10. Calculations of microwave brightness temperature of rough soil surfaces: Bare field

    NASA Technical Reports Server (NTRS)

    Mo, T.; Schmugge, T. J.; Wang, J. R.

    1985-01-01

    A model for simulating the brightness temperatures of soils with rough surfaces is developed. The surface emissivity of the soil media is obtained by the integration of the bistatic scattering coefficients for rough surfaces. The roughness of a soil surface is characterized by two parameters, the surface height standard deviation sigma and its horizontal correlation length l. The model calculations are compared to the measured angular variations of the polarized brightness temperatures at both 1.4 GHz and 5 GHz frequences. A nonlinear least-squares fitting method is used to obtain the values of delta and l that best characterize the surface roughness. The effect of shadowing is incorporated by introducing a function S(theta), which represents the probability that a point on a rough surface is not shadowed by other parts of the surface. The model results for the horizontal polarization are in excellent agreement with the data. However, for the vertical polarization, some discrepancies exist between the calculations and data, particularly at the 1.4 GHz frequency. Possible causes of the discrepancy are discussed.

  11. Bright high-order harmonic generation with controllable polarization from a relativistic plasma mirror

    PubMed Central

    Chen, Zi-Yu; Pukhov, Alexander

    2016-01-01

    Ultrafast extreme ultraviolet (XUV) sources with a controllable polarization state are powerful tools for investigating the structural and electronic as well as the magnetic properties of materials. However, such light sources are still limited to only a few free-electron laser facilities and, very recently, to high-order harmonic generation from noble gases. Here we propose and numerically demonstrate a laser–plasma scheme to generate bright XUV pulses with fully controlled polarization. In this scheme, an elliptically polarized laser pulse is obliquely incident on a plasma surface, and the reflected radiation contains pulse trains and isolated circularly or highly elliptically polarized attosecond XUV pulses. The harmonic polarization state is fully controlled by the laser–plasma parameters. The mechanism can be explained within the relativistically oscillating mirror model. This scheme opens a practical and promising route to generate bright attosecond XUV pulses with desirable ellipticities in a straightforward and efficient way for a number of applications. PMID:27531047

  12. Mesopause Horizontal wind estimates based on AIM CIPS polar mesospheric cloud pattern matching

    NASA Astrophysics Data System (ADS)

    Rong, P.; Yue, J.; Russell, J. M.; Gong, J.; Wu, D. L.; Randall, C. E.

    2013-12-01

    A cloud pattern matching approach is used to estimate horizontal winds in the mesopause region using Polar Mesospheric Cloud (PMC) albedo data measured by the Cloud Imaging and Particle Size instrument on the AIM satellite. Measurements for all 15 orbits per day throughout July 2007 are used to achieve statistical significance. For each orbit, eighteen out of the twenty-seven scenes are used for the pattern matching operation. Some scenes at the lower latitudes are not included because there is barely any cloud coverage for these scenes. The frame-size chosen is about 12 degrees in longitude and 3 degrees in latitude. There is no strict criterion in choosing the frame size since PMCs are widespread in the polar region and most local patterns do not have a clearly defined boundary. The frame moves at a step of 1/6th of the frame size in both the longitudinal and latitudinal directions to achieve as many 'snap-shots' as possible. A 70% correlation is used as a criterion to define an acceptable match between two patterns at two time frames; in this case the time difference is about 3.6 minutes that spans every 5 'bowtie' scenes. A 70% criterion appears weak if the chosen pattern is expected to act like a tracer. It is known that PMC brightness varies rapidly with a changing temperature and water vapor environment or changing nucleation conditions, especially on smaller spatial scales; therefore PMC patterns are not ideal tracers. Nevertheless, within a short time span such as 3.6 minutes a 70% correlation is sufficient to identify two cloud patterns that come from the same source region, although the two patterns may exhibit a significant difference in the actual brightness. Analysis of a large number of matched cloud patterns indicates that over the 3.6-minute time span about 70% of the patterns remain in the same locations. Given the 25-km2 horizontal resolution of CIPS data, this suggests that the overall magnitude of horizontal wind at PMC altitudes (~80-87 km) in

  13. Microwave brightness temperature of a windblown sea

    NASA Technical Reports Server (NTRS)

    Hall, F. G.

    1972-01-01

    A mathematical model is developed for the apparent temperature of the sea at all microwave frequencies. The model is a numerical model in which both the clear water structure and white water are accounted for as a function of wind speed. The model produces results similar to Stogryn's model at 19.35 GHz for wind speeds less than 8 m/sec; it can use radiosonde data to calculate atmospheric effects and can incorporate an empirically determined antenna gain pattern. The corresponding computer program is of modular design and the logic of the main program is capable of treating a horizontally inhomogeneous surface or atmosphere. It is shown that a variation of microwave brightness temperature with zenith angle is necessary to produce the wind sensitivity of the horizontally polarized brightness temperature; the variation of sky temperature with frequency is sufficient to produce a frequency dependent wind sensitivity.

  14. Polarization switching of sodium guide star laser for brightness enhancement

    NASA Astrophysics Data System (ADS)

    Fan, Tingwei; Zhou, Tianhua; Feng, Yan

    2016-07-01

    The efficiency of optical pumping that enhances the brightness of sodium laser guide star with circularly polarized light is reduced substantially due to the precession of sodium atoms in geomagnetic field. Switching the laser between left and right circular polarization at the Larmor frequency is proposed to improve the photon return. With ESO's cw laser guide star system at Paranal as example, numerical simulation for both square-wave and sine-wave polarization modulation is conducted. For the square-wave switching case, the return flux is increased when the angle between geomagnetic field and laser beam is larger than 60°, as much as 40% at 90°. The method can also be applied for remote measurement of magnetic field with available cw guide star laser.

  15. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism.

    PubMed

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J; Mancuso, Christopher A; Hogle, Craig W; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L; Dorney, Kevin M; Chen, Cong; Shpyrko, Oleg G; Fullerton, Eric E; Cohen, Oren; Oppeneer, Peter M; Milošević, Dejan B; Becker, Andreas; Jaroń-Becker, Agnieszka A; Popmintchev, Tenio; Murnane, Margaret M; Kapteyn, Henry C

    2015-11-17

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform.

  16. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism

    PubMed Central

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D.; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J.; Mancuso, Christopher A.; Hogle, Craig W.; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L.; Dorney, Kevin M.; Chen, Cong; Shpyrko, Oleg G.; Fullerton, Eric E.; Cohen, Oren; Oppeneer, Peter M.; Milošević, Dejan B.; Becker, Andreas; Jaroń-Becker, Agnieszka A.; Popmintchev, Tenio; Murnane, Margaret M.; Kapteyn, Henry C.

    2015-01-01

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform. PMID:26534992

  17. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism

    DOE PAGES

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; ...

    2015-11-03

    Here, we demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantummore » trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N 4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform.« less

  18. Improving sodium laser guide star brightness by polarization switching

    PubMed Central

    Fan, Tingwei; Zhou, Tianhua; Feng, Yan

    2016-01-01

    Optical pumping with circularly polarized light has been used to enhance the brightness of sodium laser guide star. But the benefit is reduced substantially due to the precession of sodium atoms in geomagnetic field. Switching the laser between left and right circular polarization at the Larmor frequency is proposed to improve the return. With ESO’s laser guide star system at Paranal as example, numerical simulation shows that the return flux is increased when the angle between geomagnetic field and laser beam is larger than 60°, as much as 50% at 90°. The proposal is significant since most astronomical observation is at angle between 60° and 90° and it only requires a minor addition to the delivery optics of present laser system. PMID:26797503

  19. Formation of a Bright Polar Hood over the Summer North Pole of Saturn in 2016

    NASA Astrophysics Data System (ADS)

    Sayanagi, Kunio M.; Blalock, John J.; Ingersoll, Andrew P.; Dyudina, Ulyana A.; Ewald, Shawn P.

    2016-10-01

    We report that a bright polar hood has formed over the north pole of Saturn, seen first in images captured by the Cassini ISS camera in 2016. When the north pole was observed during the previous period of Cassini spacecraft's high-inclination orbits in 2012-2013, the concentration of light-scattering aerosols within 2-degree latitude of the north pole appeared to be less than that of the surrounding region, and appeared as a dark hole in all ISS filters, in particular in the shorter wavelength filters BL1 (460 nm), and VIO (420 nm). The north pole's appearance in 2012 was in contrast to that of the south pole in 2007, when the south pole had a bright polar hood in those short wavelengths; the south pole appeared dark in all other ISS filters in 2007. The difference between the south pole in 2007 and the north pole in 2012 was interpreted to be seasonal; in 2007, Saturn was approaching the equinox of 2009 and the south pole had been continuously illuminated since the previous equinox in 1995. In 2012, the north pole had been illuminated for only ~3 years after the long winter polar night. The bright hood over the summer south pole in 2007 was hypothesized to consist of aerosols produced by ultraviolet photodissociation of hydrocarbon molecules. Fletcher et al (2015) predicted that a similar bright hood should form over the north pole as Saturn approaches the 2017 solstice. In 2016, the Cassini spacecraft raised its orbital inclination again in preparation for its Grande Finale phase of the mission, from where it has a good view of the north pole. New images captured in 2016 show that the north pole has developed a bright polar hood. We present new images of the north polar region captured in 2016 that show the north pole, and other seasonally evolving high-latitude features including the northern hexagon. Our research has been supported by the Cassini Project, NASA grants OPR NNX11AM45G, CDAPS NNX15AD33G PATM NNX14AK07G, and NSF grant AAG 1212216.

  20. A numerical assessment of rough surface scattering theories. I - Horizontal polarization. II - Vertical polarization

    NASA Technical Reports Server (NTRS)

    Rodriguez, Ernesto; Kim, Yunjin; Durden, Stephen L.

    1992-01-01

    A numerical evaluation is presented of the regime of validity for various rough surface scattering theories against numerical results obtained by employing the method of moments. The contribution of each theory is considered up to second order in the perturbation expansion for the surface current. Considering both vertical and horizontal polarizations, the unified perturbation method provides best results among all theories weighed.

  1. Plasmonic EIT-like switching in bright-dark-bright plasmon resonators.

    PubMed

    Chen, Junxue; Wang, Pei; Chen, Chuncong; Lu, Yonghua; Ming, Hai; Zhan, Qiwen

    2011-03-28

    In this paper we report the study of the electromagnetically induced transparency (EIT)-like transmission in the bright-dark-bright plasmon resonators. It is demonstrated that the interferences between the dark plasmons excited by two bright plasmon resonators can be controlled by the incident light polarization. The constructive interference strengthens the coupling between the bright and dark resonators, leading to a more prominent EIT-like transparency window of the metamaterial. In contrary, destructive interference suppresses the coupling between the bright and dark resonators, destroying the interference pathway that forms the EIT-like transmission. Based on this observation, the plasmonic EIT switching can be realized by changing the polarization of incident light. This phenomenon may find applications in optical switching and plasmon-based information processing.

  2. Energy-exchange collisions of dark-bright-bright vector solitons.

    PubMed

    Radhakrishnan, R; Manikandan, N; Aravinthan, K

    2015-12-01

    We find a dark component guiding the practically interesting bright-bright vector one-soliton to two different parametric domains giving rise to different physical situations by constructing a more general form of three-component dark-bright-bright mixed vector one-soliton solution of the generalized Manakov model with nine free real parameters. Moreover our main investigation of the collision dynamics of such mixed vector solitons by constructing the multisoliton solution of the generalized Manakov model with the help of Hirota technique reveals that the dark-bright-bright vector two-soliton supports energy-exchange collision dynamics. In particular the dark component preserves its initial form and the energy-exchange collision property of the bright-bright vector two-soliton solution of the Manakov model during collision. In addition the interactions between bound state dark-bright-bright vector solitons reveal oscillations in their amplitudes. A similar kind of breathing effect was also experimentally observed in the Bose-Einstein condensates. Some possible ways are theoretically suggested not only to control this breathing effect but also to manage the beating, bouncing, jumping, and attraction effects in the collision dynamics of dark-bright-bright vector solitons. The role of multiple free parameters in our solution is examined to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation of our solution. It is interesting to note that the polarization vector of our mixed vector one-soliton evolves in sphere or hyperboloid depending upon the initial parametric choices.

  3. Doubling transmission capacity in optical wireless system by antenna horizontal- and vertical-polarization multiplexing.

    PubMed

    Li, Xinying; Yu, Jianjun; Zhang, Junwen; Dong, Ze; Chi, Nan

    2013-06-15

    We experimentally demonstrate 2×56 Gb/s two-channel polarization-division-multiplexing quadrature-phase-shift-keying signal delivery over 80 km single-mode fiber-28 and 2 m Q-band (33-50 GHz) wireless link, adopting antenna horizontal- (H-) and vertical-polarization (V-polarization) multiplexing. At the wireless receiver, classic constant-modulus-algorithm equalization based on digital signal processing can realize polarization demultiplexing and remove the crosstalk at the same antenna polarization. By adopting antenna polarization multiplexing, the signal baud rate and performance requirements for optical and wireless devices can be reduced but at the cost of double antennas and devices, while wireless transmission capacity can also be increased but at the cost of stricter requirements for V-polarization. The isolation is only about 19 dB when V-polarization deviation approaches 10°, which will affect high-speed (>50 Gb/s) wireless delivery.

  4. Calculation of gyrosynchrotron radiation brightness temperature for outer bright loop of ICME

    NASA Astrophysics Data System (ADS)

    Sun, Weiying; Wu, Ji; Wang, C. B.; Wang, S.

    :Solar polar orbit radio telescope (SPORT) is proposed to detect the high density plasma clouds of outer bright loop of ICMEs from solar orbit with large inclination. Of particular interest is following the propagation of the plasma clouds with remote sensor in radio wavelength band. Gyrosynchrotron emission is a main radio radiation mechanism of the plasma clouds and can provide information of interplanetary magnetic field. In this paper, we statistically analyze the electron density, electron temperature and magnetic field of background solar wind in time of quiet sun and ICMEs propagation. We also estimate the fluctuation range of the electron density, electron temperature and magnetic field of outer bright loop of ICMEs. Moreover, we calculate and analyze the emission brightness temperature and degree of polarization on the basis of the study of gyrosynchrotron emission, absorption and polarization characteristics as the optical depth is less than or equal to 1.

  5. Spatial variations of brightness, colour and polarization of dust in comet 67P/Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    Rosenbush, Vera K.; Ivanova, Oleksandra V.; Kiselev, Nikolai N.; Kolokolova, Ludmilla O.; Afanasiev, Viktor L.

    2017-07-01

    We present post-perihelion photometric and polarimetric observations of comet 67P/Churyumov-Gerasimenko performed at the 6-m telescope of the SAO RAS in the g-sdss (465/65 nm), r-sdss (620/60 nm) and R filters. Observations in November and December 2015 and April 2016 covered the range of heliocentric distance 1.62-2.72 au and phase angle 33.2°-10.4°. The comet was very active. Two persistent jets and long dust tail were observed during the whole observing period; one more jet was detected only in December. The radial profiles of surface brightness, colour and polarization significantly differed for the coma, jets and tail, and changed with increasing heliocentric distance. The dust production Afρ decreased from 162 cm at r = 1.62 au to 51 cm at r = 2.72 au. The dust colour (g-r) gradually changed from 0.8 mag in the innermost coma to about 0.4 mag in the outer coma. The spectral slope was 8.2 ± 1.7 per cent/100 nm in the 465 to 620 nm wavelength domain. In November and December, the polarization in the near-nucleus area was about 8 per cent, dropped sharply to 2 per cent at the distance above 5000 km and then gradually increased with distance from the nucleus, reaching ˜8 per cent at 40 000 km. In April, at a phase angle 10.4°, the polarization varied between -0.6 per cent in the near-nucleus area and -4 per cent in the outer coma. Circular polarization was not detected in the comet. The spatial variations of brightness, colour and polarization in different structural features suggest some evolution of particle properties, most likely decreasing the size of dust particles.

  6. Ventral polarization vision in tabanids: horseflies and deerflies (Diptera: Tabanidae) are attracted to horizontally polarized light

    NASA Astrophysics Data System (ADS)

    Horváth, Gábor; Majer, József; Horváth, Loránd; Szivák, Ildikó; Kriska, György

    2008-11-01

    Adult tabanid flies (horseflies and deerflies) are terrestrial and lay their eggs onto marsh plants near bodies of fresh water because the larvae develop in water or mud. To know how tabanids locate their host animals, terrestrial rendezvous sites and egg-laying places would be very useful for control measures against them, because the hematophagous females are primary/secondary vectors of some severe animal/human diseases/parasites. Thus, in choice experiments performed in the field we studied the behavior of tabanids governed by linearly polarized light. We present here evidence for positive polarotaxis, i.e., attraction to horizontally polarized light stimulating the ventral eye region, in both males and females of 27 tabanid species. The novelty of our findings is that positive polarotaxis has been described earlier only in connection with the water detection of some aquatic insects ovipositing directly into water. A further particularity of our discovery is that in the order Diptera and among blood-sucking insects the studied tabanids are the first known species possessing ventral polarization vision and definite polarization-sensitive behavior with known functions. The polarotaxis in tabanid flies makes it possible to develop new optically luring traps being more efficient than the existing ones based on the attraction of tabanids by the intensity and/or color of reflected light.

  7. Ventral polarization vision in tabanids: horseflies and deerflies (Diptera: Tabanidae) are attracted to horizontally polarized light.

    PubMed

    Horváth, Gábor; Majer, József; Horváth, Loránd; Szivák, Ildikó; Kriska, György

    2008-11-01

    Adult tabanid flies (horseflies and deerflies) are terrestrial and lay their eggs onto marsh plants near bodies of fresh water because the larvae develop in water or mud. To know how tabanids locate their host animals, terrestrial rendezvous sites and egg-laying places would be very useful for control measures against them, because the hematophagous females are primary/secondary vectors of some severe animal/human diseases/parasites. Thus, in choice experiments performed in the field we studied the behavior of tabanids governed by linearly polarized light. We present here evidence for positive polarotaxis, i.e., attraction to horizontally polarized light stimulating the ventral eye region, in both males and females of 27 tabanid species. The novelty of our findings is that positive polarotaxis has been described earlier only in connection with the water detection of some aquatic insects ovipositing directly into water. A further particularity of our discovery is that in the order Diptera and among blood-sucking insects the studied tabanids are the first known species possessing ventral polarization vision and definite polarization-sensitive behavior with known functions. The polarotaxis in tabanid flies makes it possible to develop new optically luring traps being more efficient than the existing ones based on the attraction of tabanids by the intensity and/or color of reflected light.

  8. Out of the blue: the evolution of horizontally polarized signals in Haptosquilla (Crustacea, Stomatopoda, Protosquillidae).

    PubMed

    How, Martin J; Porter, Megan L; Radford, Andrew N; Feller, Kathryn D; Temple, Shelby E; Caldwell, Roy L; Marshall, N Justin; Cronin, Thomas W; Roberts, Nicholas W

    2014-10-01

    The polarization of light provides information that is used by many animals for a number of different visually guided behaviours. Several marine species, such as stomatopod crustaceans and cephalopod molluscs, communicate using visual signals that contain polarized information, content that is often part of a more complex multi-dimensional visual signal. In this work, we investigate the evolution of polarized signals in species of Haptosquilla, a widespread genus of stomatopod, as well as related protosquillids. We present evidence for a pre-existing bias towards horizontally polarized signal content and demonstrate that the properties of the polarization vision system in these animals increase the signal-to-noise ratio of the signal. Combining these results with the increase in efficacy that polarization provides over intensity and hue in a shallow marine environment, we propose a joint framework for the evolution of the polarized form of these complex signals based on both efficacy-driven (proximate) and content-driven (ultimate) selection pressures. © 2014. Published by The Company of Biologists Ltd.

  9. Is the zodiacal light intensity steady. [cloud surface brightness and polarization from OSO-5 data

    NASA Technical Reports Server (NTRS)

    Burnett, G. B.; Sparrow, J. G.; Ney, E. P.

    1974-01-01

    It is pointed out that conclusions reported by Sparrow and Ney (1972, 1973) could be confirmed in an investigation involving the refinement of OSO-5 data on zodiacal light. It had been found by Sparrow and Ney that the absolute value of both the surface brightness and polarization of the zodiacal cloud varied by less than 10% over the 4-yr period from January 1969 to January 1973.

  10. Preliminary results of radiometric measurements of clear air and cloud brightness (antenna) temperatures at 37GHz

    NASA Astrophysics Data System (ADS)

    Arakelyan, A. K.; Hambaryan, A. K.; Arakelyan, A. A.

    2012-05-01

    In this paper the results of polarization measurements of clear air and clouds brightness temperatures at 37GHz are presented. The results were obtained during the measurements carried out in Armenia from the measuring complex built under the framework of ISTC Projects A-872 and A-1524. The measurements were carried out at vertical and horizontal polarizations, under various angles of sensing by Ka-band combined scatterometric-radiometric system (ArtAr-37) developed and built by ECOSERV Remote Observation Centre Co.Ltd. under the framework of the above Projects. In the paper structural and operational features of the utilized system and the whole measuring complex will be considered and discussed as well.

  11. Scale Dependence of Cirrus Horizontal Heterogeneity Effects on TOA Measurements. Part I; MODIS Brightness Temperatures in the Thermal Infrared

    NASA Technical Reports Server (NTRS)

    Fauchez, Thomas; Platnick, Steven; Meyer, Kerry; Cornet, Celine; Szczap, Frederic; Varnai, Tamas

    2017-01-01

    This paper presents a study on the impact of cirrus cloud heterogeneities on MODIS simulated thermal infrared (TIR) brightness temperatures (BTs) at the top of the atmosphere (TOA) as a function of spatial resolution from 50 meters to 10 kilometers. A realistic 3-D (three-dimensional) cirrus field is generated by the 3DCLOUD model (average optical thickness of 1.4, cloudtop and base altitudes at 10 and 12 kilometers, respectively, consisting of aggregate column crystals of D (sub eff) equals 20 microns), and 3-D thermal infrared radiative transfer (RT) is simulated with the 3DMCPOL (3-D Monte Carlo Polarized) code. According to previous studies, differences between 3-D BT computed from a heterogenous pixel and 1-D (one-dimensional) RT computed from a homogeneous pixel are considered dependent at nadir on two effects: (i) the optical thickness horizontal heterogeneity leading to the plane-parallel homogeneous bias (PPHB); and the (ii) horizontal radiative transport (HRT) leading to the independent pixel approximation error (IPAE). A single but realistic cirrus case is simulated and, as expected, the PPHB mainly impacts the low-spatial resolution results (above approximately 250 meters), with averaged values of up to 5-7 K (thousand), while the IPAE mainly impacts the high-spatial resolution results (below approximately 250 meters) with average values of up to 1-2 K (thousand). A sensitivity study has been performed in order to extend these results to various cirrus optical thicknesses and heterogeneities by sampling the cirrus in several ranges of parameters. For four optical thickness classes and four optical heterogeneity classes, we have found that, for nadir observations, the spatial resolution at which the combination of PPHB and HRT effects is the smallest, falls between 100 and 250 meters. These spatial resolutions thus appear to be the best choice to retrieve cirrus optical properties with the smallest cloud heterogeneity-related total bias in the thermal

  12. High Velocity Horizontal Motions at the Edge of Sunspot Penumbrae

    NASA Astrophysics Data System (ADS)

    Hagenaar-Daggett, Hermance J.; Shine, R.

    2010-05-01

    The outer edges of sunspot penumbrae have long been noted as a region of interesting dynamics including formation of MMFs, extensions and retractions of the penumbral tips, fast moving (2-3 km/s) bright features dubbed"streakers", and localized regions of high speed downflows interpreted as Evershed "sinks". Using 30s cadence movies of high spatial resolution G band and Ca II H images taken by the Hinode SOT/FPP instrument from 5-7 Jan 2007, we have been investigating the penumbra around a sunspot in AR 10933. In addition to the expected phenomena, we also see occasional small dark crescent-shaped features with high horizontal velocities (6.5 km/s) in G band movies. These appear to be emitted from penumbral tips. They travel about 1.5 Mm developing a bright wake that evolves into a slower moving (1-2 km/s) bright feature. In some cases, there may be an earlier outward propagating disturbance within the penumbra. We have also analyzed available Fe 6302 Stokes V images to obtain information on the magnetic field. Although only lower resolution 6302 images made with a slower cadence are available for these particular data sets, we can establish that the features have the opposite magnetic polarity of the sunspot. This observation may be in agreement with simulations showing that a horizontal flux tube develops crests that move outward with a velocity as large as 10 km/s. This work was supported by NASA contract NNM07AA01C.

  13. SMMR data set development for GARP. [impact of cross polarization and Faraday rotation on SMMR derived brightness temperatures

    NASA Technical Reports Server (NTRS)

    Kogut, J.

    1981-01-01

    The NIMBUS 7 Scanning Multichannel Microwave Radiometer (SMMR) data are analyzed. The impact of cross polarization and Faraday rotation on SMMR derived brightness temperatures is evaluated. The algorithms used to retrieve the geophysical parameters are tested, refined, and compared with values derived by other techniques. The technical approach taken is described and the results presented.

  14. A dual polarized antenna system using a meanderline polarizer

    NASA Technical Reports Server (NTRS)

    Burger, H. A.

    1978-01-01

    Certain applications of synthetic aperture radars require transmitting on one linear polarization and receiving on two orthogonal linear polarizations for adequate characterization of the surface. To meet the current need at minimum cost, it was desirable to use two identical horizontally polarized shaped beam antennas and to change the polarization of one of them by a polarization conversion plate. The plate was realized as a four-layer meanderline polarizer designed to convert horizontal polarization to vertical.

  15. L Band Brightness Temperature Observations over a Corn Canopy during the Entire Growth Cycle

    PubMed Central

    Joseph, Alicia T.; van der Velde, Rogier; O’Neill, Peggy E.; Choudhury, Bhaskar J.; Lang, Roger H.; Kim, Edward J.; Gish, Timothy

    2010-01-01

    During a field campaign covering the 2002 corn growing season, a dual polarized tower mounted L-band (1.4 GHz) radiometer (LRAD) provided brightness temperature (TB) measurements at preset intervals, incidence and azimuth angles. These radiometer measurements were supported by an extensive characterization of land surface variables including soil moisture, soil temperature, vegetation biomass, and surface roughness. In the period May 22 to August 30, ten days of radiometer and ground measurements are available for a corn canopy with a vegetation water content (W) range of 0.0 to 4.3 kg m−2. Using this data set, the effects of corn vegetation on surface emissions are investigated by means of a semi-empirical radiative transfer model. Additionally, the impact of roughness on the surface emission is quantified using TB measurements over bare soil conditions. Subsequently, the estimated roughness parameters, ground measurements and horizontally (H)-polarized TB are employed to invert the H-polarized transmissivity (γh) for the monitored corn growing season. PMID:22163585

  16. South Polar Ar Enhancement as a Tracer for Southern Winter Horizontal Meridional Mixing

    NASA Technical Reports Server (NTRS)

    Sprague, A. L.; Boynton, W. V.; Kim, K.; Reedy, R.; Kerry, K.; Janes, D.

    2004-01-01

    Measurements made by the Gamma Ray Spectrometer (GRS) on Mars Odyssey during 2002 and 2003 show an obvious increase in the gamma flux of 1294 keV gamma rays resulting from the decay of (41)Ar. (41)Ar is made by the capture of thermal neutrons by atmospheric (40)Ar. The increase measured above the southern polar region has permitted calculation of the increase in mixing ratio of Ar from L(sub s) 8 to 100 between latitudes 75 S and 90 S. The peak in Ar enhancement occurs about 200 Earth days after CO2 freeze-out has begun, indicating that up to this time equatorward meridional mixing is rapid enough to move enhanced Ar from the polar regions northward. Although the CO2 frost depth continues to increase from L(sub s) 110 deg to 190 deg, the Ar enhancement steadily decreases to its baseline value reached at about L(sub s) 200 deg. Our data permit an estimate of the horizontal eddy mixing coefficient useful for constraining equatorward meridional mixing during southern winter and a characteristic mixing time for the polar southern winter atmosphere. Also, using the drop in excess Ar measured by the GRS from L(sub s) 110 deg to 200 deg, we estimate an eddy coefficient appropriate for meridional mixing of the entire Ar excess back to the baseline value. The horizontal eddy mixing coefficients are derived using Ar as a tracer much as the vertical eddy mixing coefficient for the Earth's troposphere is derived using CH4 as a minor constituent tracer. The estimation of meridional mixing for high latitudes at Mars is important for constraining parameters used in atmospheric modeling and predicting seasonal and daily behavior. The calculations are order of magnitude estimates that should improve as the data set becomes more robust and improves our models.

  17. Substituting the polarizer mechanism with a polarization camera - an experiment to confirm its capability

    NASA Astrophysics Data System (ADS)

    Reginald, Nelson Leslie; Gopalswamy, Natchimuthuk; Guhathakurta, Madhulika; Yashiro, Seiji

    2016-05-01

    Experiments that require polarized brightness measurements, traditionally have done so by taking three successive images through a polarizer that is rotated through three well-defined angles. With the advent of the polarization camera, the polarized brightness can be measured from a single image. This also eliminates the need for a polarizer and the associated rotator mechanisms and can contribute towards less weight, size, less power requirements, and importantly higher temporal resolution. We intend to demonstrate the capabilities of the polarization camera by conducting a field experiment in conjunction with the total solar eclipse of 21 August 2017 using the Imaging Spectrograph of Coronal Electrons (ISCORE) instrument (Reginald et. al., solar physics, 2009, 260, 347-361). In this instrumental concept four K-coronal images of the corona through four filters centered at 385.0, 398.7, 410.0, 423.3 nm with a bandpass of 4 nm are expected to allow us to determine the coronal electron temperature and electron speed all around the corona. In order to determine the K-coronal brightness through each filter, we would have to take three images by rotating a polarizer through three angles for each of the filters, and it is not feasible owing to the short durations of total solar eclipses. Therefore, in the past we have assumed the total brightness (F + K) measured by each of the four filters to represent K-coronal brightness, which is true in low solar corona. However, with the advent of the polarization camera we can now measure the Stokes Polarization Parameters on a pixel by pixel basis for every image taken by the polarization camera. This allows us to independently quantify the total brightness (K+F) and polarized brightness (K). Also in addition to the four filter images that allow us to measure the electron temperature and electron speed, taking an additional image without a filter will give us enough information to determine the electron density. This instrumental

  18. L Band Brightness Temperature Observations Over a Corn Canopy During the Entire Growth Cycle

    NASA Technical Reports Server (NTRS)

    Joseph, Alicia T.; O'Neill, Peggy E.; Choudhury, Bhaskar J.; vanderVelde, Rogier; Lang, Roger H.; Gish, Timothy

    2011-01-01

    During a field campaign covering the 2002 corn growing season, a dual polarized tower mounted L-band (1.4 GHz) radiometer (LRAD) provided brightness temperature (T(sub B)) measurements at preset intervals, incidence and azimuth angles. These radiometer measurements were supported by an extensive characterization of land surface variables including soil moisture, soil temperature, vegetation biomass, and surface roughness. During the period from May 22, 2002 to August 30, 2002 a range of vegetation water content (W) of 0.0 to 4.3 kg/square m, ten days of radiometer and ground measurements were available. Using this data set, the effects of corn vegetation on surface emissions are investigated by means of a semi-empirical radiative transfer model. Additionally, the impact of roughness on the surface emission is quantified using T(sub B) measurements over bare soil conditions. Subsequently, the estimated roughness parameters, ground measurements and horizontally (H)-polarized T(sub B) are employed to invert the H-polarized transmissivity (gamma-h) for the monitored corn growing season.

  19. SeaWinds - Oceans, Land, Polar Regions

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The SeaWinds scatterometer on the QuikScat satellite makes global radar measurements -- day and night, in clear sky and through clouds. The radar data over the oceans provide scientists and weather forecasters with information on surface wind speed and direction. Scientists also use the radar measurements directly to learn about changes in vegetation and ice extent over land and polar regions.

    This false-color image is based entirely on SeaWinds measurements obtained over oceans, land, and polar regions. Over the ocean, colors indicate wind speed with orange as the fastest wind speeds and blue as the slowest. White streamlines indicate the wind direction. The ocean winds in this image were measured by SeaWinds on September 20, 1999. The large storm in the Atlantic off the coast of Florida is Hurricane Gert. Tropical storm Harvey is evident as a high wind region in the Gulf of Mexico, while farther west in the Pacific is tropical storm Hilary. An extensive storm is also present in the South Atlantic Ocean near Antarctica.

    The land image was made from four days of SeaWinds data with the aid of a resolution enhancement algorithm developed by Dr. David Long at Brigham Young University. The lightest green areas correspond to the highest radar backscatter. Note the bright Amazon and Congo rainforests compared to the dark Sahara desert. The Amazon River is visible as a dark line running horizontally though the bright South American rain forest. Cities appear as bright spots on the images, especially in the U.S. and Europe.

    The image of Greenland and the north polar ice cap was generated from data acquired by SeaWinds on a single day. In the polar region portion of the image, white corresponds to the largest radar return, while purple is the lowest. The variations in color in Greenland and the polar ice cap reveal information about the ice and snow conditions present.

    NASA's Earth Science Enterprise is a long-term research and technology program designed to

  20. Inferring Land Surface Model Parameters for the Assimilation of Satellite-Based L-Band Brightness Temperature Observations into a Soil Moisture Analysis System

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf H.; De Lannoy, Gabrielle J. M.

    2012-01-01

    The Soil Moisture and Ocean Salinity (SMOS) satellite mission provides global measurements of L-band brightness temperatures at horizontal and vertical polarization and a variety of incidence angles that are sensitive to moisture and temperature conditions in the top few centimeters of the soil. These L-band observations can therefore be assimilated into a land surface model to obtain surface and root zone soil moisture estimates. As part of the observation operator, such an assimilation system requires a radiative transfer model (RTM) that converts geophysical fields (including soil moisture and soil temperature) into modeled L-band brightness temperatures. At the global scale, the RTM parameters and the climatological soil moisture conditions are still poorly known. Using look-up tables from the literature to estimate the RTM parameters usually results in modeled L-band brightness temperatures that are strongly biased against the SMOS observations, with biases varying regionally and seasonally. Such biases must be addressed within the land data assimilation system. In this presentation, the estimation of the RTM parameters is discussed for the NASA GEOS-5 land data assimilation system, which is based on the ensemble Kalman filter (EnKF) and the Catchment land surface model. In the GEOS-5 land data assimilation system, soil moisture and brightness temperature biases are addressed in three stages. First, the global soil properties and soil hydraulic parameters that are used in the Catchment model were revised to minimize the bias in the modeled soil moisture, as verified against available in situ soil moisture measurements. Second, key parameters of the "tau-omega" RTM were calibrated prior to data assimilation using an objective function that minimizes the climatological differences between the modeled L-band brightness temperatures and the corresponding SMOS observations. Calibrated parameters include soil roughness parameters, vegetation structure parameters

  1. Quantifying spatial and temporal variabilities of microwave brightness temperature over the U.S. Southern Great Plains

    NASA Technical Reports Server (NTRS)

    Choudhury, B. J.; Owe, M.; Ormsby, J. P.; Chang, A. T. C.; Wang, J. R.; Goward, S. N.; Golus, R. E.

    1987-01-01

    Spatial and temporal variabilities of microwave brightness temperature over the U.S. Southern Great Plains are quantified in terms of vegetation and soil wetness. The brightness temperatures (TB) are the daytime observations from April to October for five years (1979 to 1983) obtained by the Nimbus-7 Scanning Multichannel Microwave Radiometer at 6.6 GHz frequency, horizontal polarization. The spatial and temporal variabilities of vegetation are assessed using visible and near-infrared observations by the NOAA-7 Advanced Very High Resolution Radiometer (AVHRR), while an Antecedent Precipitation Index (API) model is used for soil wetness. The API model was able to account for more than 50 percent of the observed variability in TB, although linear correlations between TB and API were generally significant at the 1 percent level. The slope of the linear regression between TB and API is found to correlate linearly with an index for vegetation density derived from AVHRR data.

  2. Brightness and magnetic evolution of solar coronal bright points

    NASA Astrophysics Data System (ADS)

    Ugarte-Urra, I.

    2004-12-01

    This thesis presents a study of the brightness and magnetic evolution of several Extreme ultraviolet (EUV) coronal bright points (hereafter BPs). BPs are loop-like features of enhanced emission in the coronal EUV and X-ray images of the Sun, that are associated to the interaction of opposite photospheric magnetic polarities with magnetic fluxes of ≈1018 - 1019 Mx. The study was carried out using several instruments on board the Solar and Heliospheric Observatory (SOHO): the Extreme Ultraviolet Imager (EIT), the Coronal Diagnostic Spectrometer (CDS) and the Michelson Doppler Imager (MDI), supported by the high resolution imaging from the Transition Region And Coronal Explorer (TRACE). The results confirm that, down to 1'' (i.e. ~715 km) resolution, BPs are made of small loops with lengths of ~6 Mm and cross-sections of ~2 Mm. The loops are very dynamic, evolving in time scales as short as 1 - 2 minutes. This is reflected in a highly variable EUV response with fluctuations highly correlated in spectral lines at transition region temperatures (in the range 3.2x10^4 - 3.5x10^5 K), but not always at coronal temperatures. A wavelet analysis of the intensity variations reveals, for the first time, the existence of quasi-periodic oscillations with periods ranging 400 -- 1000 s, in the range of periods characteristic of the chromospheric network. The link between BPs and network bright points is discussed, as well as the interpretation of the oscillations in terms of global acoustic modes of closed magnetic structures. A comparison of the magnetic flux evolution of the magnetic polarities to the EUV flux changes is also presented. Throughout their lifetime, the intrinsic EUV emission of BPs is found to be dependent on the total magnetic flux of the polarities. In short time scales, co-spatial and co-temporal TRACE and MDI images, reveal the signature of heating events that produce sudden EUV brightenings simultaneous to magnetic flux cancellations. This is interpreted in

  3. Bright Linearly and Circularly Polarized Extreme Ultraviolet and Soft X-ray High Harmonics for Absorption Spectroscopy

    NASA Astrophysics Data System (ADS)

    Fan, Tingting

    High harmonic generation (HHG) is an extreme nonlinear optical process. When implemented in a phase-matched geometry, HHG coherent upconverts femtosecond laser light into coherent "X-ray laser" beams, while retaining excellent spatial and temporal coherence, as well as the polarization state of the driving laser. HHG has a tabletop footprint, with femtosecond to attosecond time resolution, combined with nanometer spatial resolution. As a consequence of these unique capabilities, HHG is now being widely adopted for use in molecular spectroscopy and imaging, materials science, as well as nanoimaging in general. In the first half of this thesis, I demonstrate high flux linearly polarized soft X-ray HHG, driven by a single-stage 10-mJ Ti:sapphire regenerative amplifier at a repetition rate of 1 kHz. I first down-converted the laser to 1.3 mum using an optical parametric amplifier, before up-converting it into the soft X-ray region using HHG in a high-pressure, phase-matched, hollow waveguide geometry. The resulting optimally phase-matched broadband spectrum extends to 200 eV, with a soft X-ray photon flux of > 106 photons/pulse/1% bandwidth at 1 kHz, corresponding to > 109 photons/s/1% bandwidth, or approximately a three orders-of-magnitude increase compared with past work. Using this broad bandwidth X-ray source, I demonstrated X-ray absorption spectroscopy of multiple elements and transitions in molecules in a single spectrum, with a spectral resolution of 0.25 eV, and with the ability to resolve the near edge fine structure. In the second half of this thesis, I discuss how to generate the first bright circularly polarized (CP) soft X-ray HHG and also use them to implement the first tabletop X-ray magnetic circular dichroism (XMCD) measurements. Using counter-rotating CP lasers at 1.3 mum and 0.79 mum, I generated CPHHG with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right CP peaks, with energies

  4. Brightness and magnetic evolution of solar coronal bright points

    NASA Astrophysics Data System (ADS)

    Ugarte Urra, Ignacio

    This thesis presents a study of the brightness and magnetic evolution of several Extreme ultraviolet (EUV) coronal bright points (hereafter BPs). The study was carried out using several instruments on board the Solar and Heliospheric Observatory, supported by the high resolution imaging from the Transition Region And Coronal Explorer. The results confirm that, down to 1" resolution, BPs are made of small loops with lengths of [approximate]6 Mm and cross-sections of ≈2 Mm. The loops are very dynamic, evolving in time scales as short as 1 - 2 minutes. This is reflected in a highly variable EUV response with fluctuations highly correlated in spectral lines at transition region temperatures, but not always at coronal temperatures. A wavelet analysis of the intensity variations reveals the existence of quasi-periodic oscillations with periods ranging 400--1000s, in the range of periods characteristic of the chromospheric network. The link between BPs and network bright points is discussed, as well as the interpretation of the oscillations in terms of global acoustic modes of closed magnetic structures. A comparison of the magnetic flux evolution of the magnetic polarities to the EUV flux changes is also presented. Throughout their lifetime, the intrinsic EUV emission of BPs is found to be dependent on the total magnetic flux of the polarities. In short time scales, co-spatial and co-temporal coronal images and magnetograms, reveal the signature of heating events that produce sudden EUV brightenings simultaneous to magnetic flux cancellations. This is interpreted in terms of magnetic reconnection events. Finally, a electron density study of six coronal bright points produces values of ≈1.6×10 9 cm -3 , closer to active region plasma than to quiet Sun. The analysis of a large coronal loop (half length of 72 Mm) introduces the discussion on the prospects of future plasma diagnostics of BPs with forthcoming solar missions.

  5. The ultraviolet-bright stars of Omega Centauri, M3, and M13

    NASA Technical Reports Server (NTRS)

    Landsman, Wayne B.; O'Connell, Robert W.; Whitney, Jonathan H.; Bohlin, Ralph C.; Hill, Robert S.; Maran, Stephen P.; Parise, Ronald A.; Roberts, Morton S.; Smith, Andrew A.; Stecher, Theodore P.

    1992-01-01

    Two new UV-bright stars detected within 2 arcmin of the center of Omega Cen are spectroscopically investigated with the short-wavelength spectrograph of the IUE. The IUE spectra of the UV-bright stars UIT-1 and UIT-2 in the core of Omega Cen superficially resemble those of Population I mid-B stars. The absorption lines of the core UV-bright stars are significantly weaker than in Population I stars, consistent with their membership in the cluster. Synthetic spectra calculated from low-metallicity Kurucz model stellar atmospheres are compared with the spectra. These objects are insufficiently luminous to be classical hydrogen-burning post-AGB stars. They may be evolved hot horizontal branch stars which have been brightened by more than 3 mag since leaving the zero-age horizontal branch. It is inferred from the spectra and luminosity of the core UV-bright stars that similar objects could provide the source of the UV light in elliptical galaxies.

  6. Production, formation, and transport of high-brightness atomic hydrogen beam studies for the relativistic heavy ion collider polarized source upgrade.

    PubMed

    Kolmogorov, A; Atoian, G; Davydenko, V; Ivanov, A; Ritter, J; Stupishin, N; Zelenski, A

    2014-02-01

    The RHIC polarized H(-) ion source had been successfully upgraded to higher intensity and polarization by using a very high brightness fast atomic beam source developed at BINP, Novosibirsk. In this source the proton beam is extracted by a four-grid multi-aperture ion optical system and neutralized in the H2 gas cell downstream from the grids. The proton beam is extracted from plasma emitter with a low transverse ion temperature of ∼0.2 eV which is formed by plasma jet expansion from the arc plasma generator. The multi-hole grids are spherically shaped to produce "geometrical" beam focusing. Proton beam formation and transport of atomic beam were experimentally studied at test bench.

  7. Bright-dark soliton pairs in a self-mode locking fiber laser

    NASA Astrophysics Data System (ADS)

    Meng, Yichang; Zhang, Shumin; Li, Hongfei; Du, Juan; Hao, Yanping; Li, Xingliang

    2012-06-01

    We have experimentally observed bright-dark soliton pairs in an erbium-doped fiber ring laser for the first time. This approach is different from the vector dark domain wall solitons which separate the two orthogonal linear polarization eigenstates of the laser emission. In our laser, the bright-dark soliton pairs can co-exist in any one polarization state. Numerical simulations based on the coupled complex Ginzburg-Landau equations have confirmed the experimental results.

  8. Generalized dark-bright vector soliton solution to the mixed coupled nonlinear Schrödinger equations.

    PubMed

    Manikandan, N; Radhakrishnan, R; Aravinthan, K

    2014-08-01

    We have constructed a dark-bright N-soliton solution with 4N+3 real parameters for the physically interesting system of mixed coupled nonlinear Schrödinger equations. Using this as well as an asymptotic analysis we have investigated the interaction between dark-bright vector solitons. Each colliding dark-bright one-soliton at the asymptotic limits includes more coupling parameters not only in the polarization vector but also in the amplitude part. Our present solution generalizes the dark-bright soliton in the literature with parametric constraints. By exploiting the role of such coupling parameters we are able to control certain interaction effects, namely beating, breathing, bouncing, attraction, jumping, etc., without affecting other soliton parameters. Particularly, the results of the interactions between the bound state dark-bright vector solitons reveal oscillations in their amplitudes under certain parametric choices. A similar kind of effect was also observed experimentally in the BECs. We have also characterized the solutions with complicated structure and nonobvious wrinkle to define polarization vector, envelope speed, envelope width, envelope amplitude, grayness, and complex modulation. It is interesting to identify that the polarization vector of the dark-bright one-soliton evolves on a spherical surface instead of a hyperboloid surface as in the bright-bright case of the mixed coupled nonlinear Schrödinger equations.

  9. Si III OV Bright Line of Scattering Polarized Light That Has Been Observed in the CLASP and Its Center-to-Limb Variation

    NASA Technical Reports Server (NTRS)

    Katsukawa, Yukio; Ishikawa, Ryoko; Kano, Ryohei; Kubo, Masahito; Noriyuki, Narukage; Kisei, Bando; Hara, Hirohisa; Yoshiho, Suematsu; Goto, Motouji; Ishikawa, Shinnosuke; hide

    2017-01-01

    The CLASP (Chromospheric Lyman-Alpha Spectro- Polarimeter) rocket experiment, in addition to the ultraviolet region of the Ly alpha emission line (121.57 nm), emission lines of Si III (120.65 nm) and OV (121.83 nm) is can be observed. These are optically thin line compared to a Ly alpha line, if Rarere captured its polarization, there is a possibility that dripping even a new physical diagnosis chromosphere-transition layer. In particular, OV bright light is a release from the transition layer, further, three P one to one S(sub 0) is a forbidden line (cross-triplet transition between lines), it was not quite know whether to polarization.

  10. The Skylab ten color photoelectric polarimeter. [sky brightness

    NASA Technical Reports Server (NTRS)

    Weinberg, J. L.; Hahn, R. C.; Sparrow, J. G.

    1975-01-01

    A 10-color photoelectric polarimeter was used during Skylab missions SL-2 and SL-3 to measure sky brightness and polarization associated with zodiacal light, background starlight, and the spacecraft corona. A description is given of the instrument and observing routines together with initial results on the spacecraft corona and polarization of the zodiacal light.

  11. Effect of horizontal displacements due to ocean tide loading on the determination of polar motion and UT1

    NASA Astrophysics Data System (ADS)

    Scherneck, Hans-Georg; Haas, Rüdiger

    We show the influence of horizontal displacements due to ocean tide loading on the determination of polar motion and UT1 (PMU) on the daily and subdaily timescale. So called ‘virtual PMU variations’ due to modelling errors of ocean tide loading are predicted for geodetic Very Long Baseline Interferometry (VLBI) networks. This leads to errors of subdaily determination of PMU. The predicted effects are confirmed by the analysis of geodetic VLBI observations.

  12. Natural vibration frequencies of horizontal tubes partially filled with liquid

    NASA Astrophysics Data System (ADS)

    Santisteban Hidalgo, Juan Andrés; Gama, Antonio Lopes; Moreira, Roger Matsumoto

    2017-11-01

    This work presents an experimental and numerical study on the flexural vibration of horizontal circular tubes partially filled with liquid. The tube is configured as a free-free beam with attention being directed to the case of small amplitudes of transverse oscillation whereas the axial movements of the tube and liquid are disregarded. At first vertical and horizontal polarizations of the flexural tube are investigated experimentally for different amounts of filling liquid. In contrast with the empty and fully-filled tubes, it is observed that natural frequencies of the vertical and horizontal polarizations are different due to asymmetry induced by the liquid layer, which acts like an added mass. Less mass of liquid is added to the tube when oscillating horizontally; as a consequence, eigenfrequencies for the horizontal polarization are found to be greater than the case of the vertically polarized tube. A simple method to calculate the natural vibration frequencies using coefficients of added mass of liquid is proposed. It is shown that the added mass coefficient increases with the liquid's level and viscosity. At last a numerical investigation of the interaction between the liquid and the tube is carried out by solving in two-dimensions the full Navier-Stokes equations via a finite volume method, with the free-surface flow being modeled with a homogeneous multiphase Eulerian-Eulerian fluid approach. Vertical and horizontal polarizations are imposed to the tube with pressure and shear stresses being determined numerically to assess the liquid's forcing onto the tube's wall. The coefficient of added mass of liquid is then estimated by the ratio between the resulting force and the acceleration imposed to the wall. A good agreement is found between experimental and numerical results, especially for the horizontally oscillating tube. It is also shown that viscosity can noticeably affect the added mass coefficients, particularly at low filling levels.

  13. Auroral bright spot in Jupiter’s active region in corresponding to solar wind dynamic

    NASA Astrophysics Data System (ADS)

    Haewsantati, K.; Wannawichian, S.; Clarke, J. T.; Nichols, J. D.

    2017-09-01

    Jupiter’s polar emission has brightness whose behavior appears to be unstable. This work focuses on the bright spot in active region which is a section of Jupiter’s polar emission. Images of the aurora were taken by Advanced Camera for Surveys (ACS) onboard the Hubble Space Telescope (HST). Previously, two bright spots, which were found on 13 th May 2007, were suggested to be fixed on locations described by system III longitude. The bright spot’s origin in equatorial plane was proposed to be at distance 80-90 Jovian radii and probably associated with the solar wind properties. This study analyzes additional data on May 2007 to study long-term variation of brightness and locations of bright spots. The newly modified magnetosphere-ionosphere mapping based on VIP4 and VIPAL model is used to locate the origin of bright spot in magnetosphere. Furthermore, the Michigan Solar Wind Model or mSWiM is also used to study the variation of solar wind dynamic pressure during the time of bright spot’s observation. We found that the bright spots appear in similar locations which correspond to similar origins in magnetosphere. In addition, the solar wind dynamic pressure should probably affect the bright spot’s variation.

  14. Polar Chromospheric Signatures of the Subdued Cycle 23/24 Solar Minimum

    NASA Technical Reports Server (NTRS)

    Gopalswamy, N.; Yashiro, S.; Makela, P.; Shibasaki, K.; Hathaway, D.

    2010-01-01

    Coronal holes appear brighter than the quiet Sun in microwave images, with a brightness enhancement of 500 to 2000 K. The brightness enhancement corresponds to the upper chromosphere, where the plasma temperature is about 10000 K. We constructed a microwave butterfly diagram using the synoptic images obtained by the Nobeyama radioheliograph (NoRH) showing the evolution of the polar and low latitude brightness temperature. While the polar brightness reveals the chromospheric conditions, the low latitude brightness is attributed to active regions in the corona. When we compared the microwave butterfly diagram with the magnetic butterfly diagram, we found a good correlation between the microwave brightness enhancement and the polar field strength. The microwave butterfly diagram covers part of solar cycle 22, whole of cycle 23, and part of cycle 24, thus enabling comparison between the cycle 23/24 and cycle 22/23 minima. The microwave brightness during the cycle 23/24 minimum was found to be lower than that during the cycle 22/23 minimum by approximately 250 K. The reduced brightness temperature is consistent with the reduced polar field strength during the cycle 23/24 minimum seen in the magnetic butterfly diagram. We suggest that the microwave brightness at the solar poles is a good indicator of the speed of the solar wind sampled by Ulysses at high latitudes.

  15. 35 GHz Measurements of CO2 Crystals for Simulating Observations of the Martian Polar Caps

    NASA Technical Reports Server (NTRS)

    Foster, J. L.; Chang, A. T. C.; Hall, D. K.; Tait, A. B.; Barton, J. S.

    1998-01-01

    In order to learn more about the Martian polar caps, it is important to compare and contrast the behavior of both frozen H2O and CO2 in different parts of the electromagnetic spectrum. Relatively little attention has been given, thus far, to observing the thermal microwave part of the spectrum. In this experiment, passive microwave radiation emanating from within a 33 cm snowpack was measured with a 35 GHz hand-held radiometer, and in addition to the natural snow measurements, the radiometer was used to measure the microwave emission and scattering from layers of manufactured CO2 (dry ice). A 1 m x 2 m plate of aluminum sheet metal was positioned beneath the natural snow so that microwave emissions from the underlying soil layers would be minimized. Compared to the natural snow crystals, results for the dry ice layers exhibit lower' microwave brightness temperatures for similar thicknesses, regardless of the incidence angle of the radiometer. For example, at 50 degree H (horizontal polarization) and with a covering of 21 cm of snow and 18 cm of dry ice, the brightness temperatures were 150 K and 76 K, respectively. When the snow depth was 33 cm, the brightness temperature was 144 K, and when the total thickness of the dry ice was 27 cm, the brightness temperature was 86 K. The lower brightness temperatures are due to a combination of the lower physical temperature and the larger crystal sizes of the commercial CO2 Crystals compared to the snow crystals. As the crystal size approaches the size of the microwave wavelength, it scatters microwave radiation more effectively, thus lowering the brightness temperature. The dry ice crystals in this experiment were about an order of magnitude larger than the snow crystals and three orders of magnitude larger than the CO2 Crystals produced in the cold stage of a scanning electron microscope. Spreading soil, approximately 2 mm in thickness, on the dry ice appeared to have no effect on the brightness temperatures.

  16. Polar UVI observations of dayside auroral transient events

    NASA Astrophysics Data System (ADS)

    Vorobjev, V. G.; Yagodkina, O. I.; Sibeck, D. G.; Liou, K.; Meng, C.-I.

    2001-12-01

    We analyze Polar Ultraviolet Imager (UVI) observations of auroral transient events (ATEs) in the dayside Northern Hemisphere. During 5 winter months in 1996 and 1997, we found 31 prenoon ATEs but only 13 afternoon events. Prenoon and afternoon event characteristics differ. Prenoon ATEs generally appear as bright spots of auroral luminosity in the area from 0800 to 1000 magnetic local time (MLT) and 74.5° and 76.5° corrected geomagnetic latitude (CGL). Bright aurorae then quickly expand westward and poleward, accompanied by high-latitude magnetic impulsive events (MIE) and traveling convection vortices (TCV). Afternoon ATEs usually appear as a sudden intensification of aurorae in the area from 1400 to 1600 MLT and 75.5° to 78.5° CGL. Within 15-20 min the bright band of luminosity extends eastward to reach 2000-2100 MLT at 70°-72° CGL. Although midlatitude and low-latitude ground magnetograms in the evening sector record increases in the horizontal component of the magnetic field, no corresponding features occur at stations in the morning sector. Afternoon ATEs correspond to abrupt changes in the interplanetary magnetic field (IMF) orientation, but not to significant variations of the solar wind dynamic pressure, indicating that the auroral transient events occur as part of the magnetospheric response to abrupt changes in the foreshock geometry.

  17. Helicity-Selective Enhancement and Polarization Control of Attosecond High Harmonic Waveforms Driven by Bichromatic Circularly Polarized Laser Fields.

    PubMed

    Dorney, Kevin M; Ellis, Jennifer L; Hernández-García, Carlos; Hickstein, Daniel D; Mancuso, Christopher A; Brooks, Nathan; Fan, Tingting; Fan, Guangyu; Zusin, Dmitriy; Gentry, Christian; Grychtol, Patrik; Kapteyn, Henry C; Murnane, Margaret M

    2017-08-11

    High harmonics driven by two-color counterrotating circularly polarized laser fields are a unique source of bright, circularly polarized, extreme ultraviolet, and soft x-ray beams, where the individual harmonics themselves are completely circularly polarized. Here, we demonstrate the ability to preferentially select either the right or left circularly polarized harmonics simply by adjusting the relative intensity ratio of the bichromatic circularly polarized driving laser field. In the frequency domain, this significantly enhances the harmonic orders that rotate in the same direction as the higher-intensity driving laser. In the time domain, this helicity-dependent enhancement corresponds to control over the polarization of the resulting attosecond waveforms. This helicity control enables the generation of circularly polarized high harmonics with a user-defined polarization of the underlying attosecond bursts. In the future, this technique should allow for the production of bright highly elliptical harmonic supercontinua as well as the generation of isolated elliptically polarized attosecond pulses.

  18. New kind of polarotaxis governed by degree of polarization: attraction of tabanid flies to differently polarizing host animals and water surfaces.

    PubMed

    Egri, Ádám; Blahó, Miklós; Sándor, András; Kriska, György; Gyurkovszky, Mónika; Farkas, Róbert; Horváth, Gábor

    2012-05-01

    Aquatic insects find their habitat from a remote distance by means of horizontal polarization of light reflected from the water surface. This kind of positive polarotaxis is governed by the horizontal direction of polarization (E-vector). Tabanid flies also detect water by this kind of polarotaxis. The host choice of blood-sucking female tabanids is partly governed by the linear polarization of light reflected from the host's coat. Since the coat-reflected light is not always horizontally polarized, host finding by female tabanids may be different from the established horizontal E-vector polarotaxis. To reveal the optical cue of the former polarotaxis, we performed choice experiments in the field with tabanid flies using aerial and ground-based visual targets with different degrees and directions of polarization. We observed a new kind of polarotaxis being governed by the degree of polarization rather than the E-vector direction of reflected light. We show here that female and male tabanids use polarotaxis governed by the horizontal E-vector to find water, while polarotaxis based on the degree of polarization serves host finding by female tabanids. As a practical by-product of our studies, we explain the enigmatic attractiveness of shiny black spheres used in canopy traps to catch tabanids.

  19. New kind of polarotaxis governed by degree of polarization: attraction of tabanid flies to differently polarizing host animals and water surfaces

    NASA Astrophysics Data System (ADS)

    Egri, Ádám; Blahó, Miklós; Sándor, András; Kriska, György; Gyurkovszky, Mónika; Farkas, Róbert; Horváth, Gábor

    2012-05-01

    Aquatic insects find their habitat from a remote distance by means of horizontal polarization of light reflected from the water surface. This kind of positive polarotaxis is governed by the horizontal direction of polarization (E-vector). Tabanid flies also detect water by this kind of polarotaxis. The host choice of blood-sucking female tabanids is partly governed by the linear polarization of light reflected from the host's coat. Since the coat-reflected light is not always horizontally polarized, host finding by female tabanids may be different from the established horizontal E-vector polarotaxis. To reveal the optical cue of the former polarotaxis, we performed choice experiments in the field with tabanid flies using aerial and ground-based visual targets with different degrees and directions of polarization. We observed a new kind of polarotaxis being governed by the degree of polarization rather than the E-vector direction of reflected light. We show here that female and male tabanids use polarotaxis governed by the horizontal E-vector to find water, while polarotaxis based on the degree of polarization serves host finding by female tabanids. As a practical by-product of our studies, we explain the enigmatic attractiveness of shiny black spheres used in canopy traps to catch tabanids.

  20. Dark and Bright Terrains of Pluto

    NASA Image and Video Library

    2015-07-10

    These circular maps shows the distribution of Pluto's dark and bright terrains as revealed by NASA's New Horizons mission prior to July 4, 2015. Each map is an azimuthal equidistant projection centered on the north pole, with latitude and longitude indicated. Both a gray-scale and color version are shown. The gray-scale version is based on 7 days of panchromatic imaging from the Long Range Reconnaissance Imager (LORRI), whereas the color version uses the gray-scale base and incorporates lower-resolution color information from the Multi-spectral Visible Imaging Camera (MVIC), part of the Ralph instrument. The color version is also shown in a simple cylindrical projection in PIA19700. In these maps, the polar bright terrain is surrounded by a somewhat darker polar fringe, one whose latitudinal position varies strongly with longitude. Especially striking are the much darker regions along the equator. A broad dark swath ("the whale") stretches along the equator from approximately 20 to 160 degrees of longitude. Several dark patches appear in a regular sequence centered near 345 degrees of longitude. A spectacular bright region occupies Pluto's mid-latitudes near 180 degrees of longitude, and stretches southward over the equator. New Horizons' closest approach to Pluto will occur near this longitude, which will permit high-resolution visible imaging and compositional mapping of these various regions. http://photojournal.jpl.nasa.gov/catalog/PIA19706

  1. Photometry of Polar-Ring Galaxies

    NASA Astrophysics Data System (ADS)

    Godínez-Martínez, A.; Watson, A. M.; Matthews, L. D.; Sparke, L. S.

    2007-10-01

    We have obtained photometry in B and R for seven confirmed or probable polar-ring galaxies from the Polar-Ring Catalog of Whitmore et al. (1990). The rings show a range of colors from B - R ≈ 0.6 to B - R ≈ 1.7. The bluest rings have bright H II regions, which are direct evidence for recent star formation. The minimum age of the reddest ring, that in PRC B-20, is somewhat uncertain because of a lack of knowledge of the internal reddening and metallicity, but appears to be at least 1.2 Gyr. As such, this ring is likely to be stable for at least several rotation periods. This ring is an excellent candidate for future studies that might better determine if it is truly old.

  2. Quantitative analysis of frequency-domain induced polarization soundings over horizontal beds

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Patella, D.; Schiavone, D.

    1976-06-01

    Following up a recent study of an indirect procedure for the practical determination of the maximum frequency-effect, defined as fe = I - rho/sub infinity//rho/sub dc/ with rho/sub infinity/ the resistivity at infinite frequency, it is shown at first how, through the Laplace transform theory, rho/sub infinity/ can be related to stationary field vectors in the simple form of Ohm's law. Then applying the equation of continuity for stationary currents with a suitable set of boundary conditions, the integral expression of the apparent resistivity at infinite frequency is derived rho/sub infinity,a/ in the case of a horizontally layered earth. Finally,more » from the definition of the maximum apparent frequency-effect, analytical expressions of fe/sub a/ are obtained for both Schlumberger and dipole arrays placed on the surface of the multi-layered earth section in the most general situation of vertical changes in induced polarization together with dc resistivity variations not at the same interfaces. Direct interpretation procedures are suggested for obtaining the layering parameters directly from the analysis of the sounding curves.« less

  3. Derivation of the horizontal wind field in the polar mesopause region by using successive images of noctilucent clouds observed by a color digital camera in Iceland

    NASA Astrophysics Data System (ADS)

    Suzuki, H.; Yamashita, R.

    2017-12-01

    It is important to quantify amplitude of turbulent motion to understand the energy and momentum budgets and distribution of minor constituents in the upper mesosphere. In particular, to know the eddy diffusion coefficient of minor constituents which are locally and impulsively produced by energetic particle precipitations in the polar mesopause is one of the most important subjects in the upper atmospheric science. One of the straight methods to know the amplitude of the eddy motion is to measure the wind field with both spatial and temporal domain. However, observation technique satisfying such requirements is limited in this region. In this study, derivation of the horizontal wind field in the polar mesopause region by tracking the motion of noctilucent clouds (NLCs) is performed. NLC is the highest cloud in the Earth which appears in a mesopause region during summer season in both polar regions. Since the vertical structure of the NLC is sufficiently thin ( within several hundred meters in typical), the apparent horizontal motion observed from ground can be regarded as the result of transportation by the horizontal winds at a single altitude. In this presentation, initial results of wind field derivation by tracking a motion of noctilucent clouds (NLC) observed by a ground-based color digital camera in Iceland is reported. The procedure for wind field estimation consists with 3 steps; (1) projects raw images to a geographical map (2) enhances NLC structures by using FFT method (3) determines horizontal velocity vectors by applying template matching method to two sequential images. In this talk, a result of the wind derivation by using successive images of NLC with 3 minutes interval and 1.5h duration observed on the night of Aug 1st, 2013 will be reported as a case study.

  4. Bright Points and Subflares in Ultraviolet Lines and X-Rays

    NASA Technical Reports Server (NTRS)

    Rovira, M.; Schmieder, B.; Demoulin, P.; Simnett, G. M.; Hagyard, M. J.; Reichmann, E.; Reichmann, E.; Tandberg-Hanssen, E.

    1999-01-01

    We have analyzed an active region which was observed in H.alpha (Multichannel Subtractive Double Pass Spectrograph), in UV lines (SMM/UVSP), and in X-rays (SMM/HXIS). In this active region there were only a few subflares and many small bright points visible in UV and in X-rays. Using an extrapolation based on the Fourier transform, we have computed magnetic field lines connecting different photospheric magnetic polarities from ground-based magnetograms. Along the magnetic inversion lines we find two different zones: (1) a high-shear region (> 70 deg) where subflares occur, and (2) a low-shear region along the magnetic inversion line where UV bright points are observed. In these latter regions the magnetic topology is complex with a mixture of polarities. According to the velocity field observed in the Si IV lamda.1402 line and the extrapolation of the magnetic field, we notice that each UV bright point is consistent with emission from low-rising loops with downflows at both ends. We notice some hard X-ray emissions above the bright-point regions with temperatures up to 8 x 10(exp 6) K, which suggests some induced reconnection due to continuous emergence of new flux. This reconnection is also enhanced by neighboring subflares.

  5. Circularly-Polarized Microstrip Antenna

    NASA Technical Reports Server (NTRS)

    Stanton, P. H.

    1985-01-01

    Microstrip construction compact for mobile applications. Circularly polarized microstrip antenna made of concentric cylindrical layers of conductive and dielectric materials. Coaxial cable feedlines connected to horizontal and vertical subelements from inside. Vertical subelement acts as ground for horizontal subelement.

  6. North Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

    In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

    The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

    Image information: VIS instrument. Latitude 86.5, Longitude 64.5 East (295.5 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation

  7. North Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

    In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

    The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

    Image information:VIS instrument. Latitude 86.5, longitude 57.4 East (302.6 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is

  8. North Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

    In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

    The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

    Image information: VIS instrument. Latitude 84.3, Longitude 314.4 East (45.6 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation

  9. North Polar Cap

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    This week we will be looking at five examples of laminar wind flow on the north polar cap. On Earth, gravity-driven south polar cap winds are termed 'catabatic' winds. Catabatic winds begin over the smooth expanse of the cap interior due to temperature differences between the atmosphere and the surface. Once begun, the winds sweep outward along the surface of the polar cap toward the sea. As the polar surface slopes down toward sealevel, the wind speeds increase. Catabatic wind speeds in the Antartic can reach several hundreds of miles per hour.

    In the images of the Martian north polar cap we can see these same type of winds. Notice the streamers of dust moving downslope over the darker trough sides, these streamers show the laminar flow regime coming off the cap. Within the trough we see turbulent clouds of dust, kicked up at the trough base as the winds slow down and enter a chaotic flow regime.

    The horizontal lines in these images are due to framelet overlap and lighting conditions over the bright polar cap.

    Image information: VIS instrument. Latitude 84.2, Longitude 57.4 East (302.6 West). 40 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation

  10. DIVERGENT HORIZONTAL SUB-SURFACE FLOWS WITHIN ACTIVE REGION 11158

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jain, Kiran; Tripathy, S. C.; Hill, F., E-mail: kjain@nso.edu, E-mail: stripathy@nso.edu, E-mail: fhill@nso.edu

    We measure the horizontal subsurface flow in a fast emerging active region (AR; NOAA 11158) using the ring-diagram technique and the Helioseismic and Magnetic Imager high spatial resolution Dopplergrams. This AR had a complex magnetic structure and displayed significant changes in morphology during its disk passage. Over a period of six days from 2011 February 11 to 16, the temporal variation in the magnitude of the total velocity is found to follow the trend of magnetic field strength. We further analyze regions of individual magnetic polarity within AR 11158 and find that the horizontal velocity components in these sub-regions havemore » significant variation with time and depth. The leading and trailing polarity regions move faster than the mixed-polarity region. Furthermore, both zonal and meridional components have opposite signs for trailing and leading polarity regions at all depths showing divergent flows within the AR. We also find a sharp decrease in the magnitude of total horizontal velocity in deeper layers around major flares. It is suggested that the re-organization of magnetic fields during flares, combined with the sunspot rotation, decreases the magnitude of horizontal flows or that the flow kinetic energy has been converted into the energy released by flares. After the decline in flare activity and sunspot rotation, the flows tend to follow the pattern of magnetic activity. We also observe less variation in the velocity components near the surface but these tend to increase with depth, further demonstrating that the deeper layers are more affected by the topology of ARs.« less

  11. Magnetic topological analysis of coronal bright points

    NASA Astrophysics Data System (ADS)

    Galsgaard, K.; Madjarska, M. S.; Moreno-Insertis, F.; Huang, Z.; Wiegelmann, T.

    2017-10-01

    Context. We report on the first of a series of studies on coronal bright points which investigate the physical mechanism that generates these phenomena. Aims: The aim of this paper is to understand the magnetic-field structure that hosts the bright points. Methods: We use longitudinal magnetograms taken by the Solar Optical Telescope with the Narrowband Filter Imager. For a single case, magnetograms from the Helioseismic and Magnetic Imager were added to the analysis. The longitudinal magnetic field component is used to derive the potential magnetic fields of the large regions around the bright points. A magneto-static field extrapolation method is tested to verify the accuracy of the potential field modelling. The three dimensional magnetic fields are investigated for the presence of magnetic null points and their influence on the local magnetic domain. Results: In nine out of ten cases the bright point resides in areas where the coronal magnetic field contains an opposite polarity intrusion defining a magnetic null point above it. We find that X-ray bright points reside, in these nine cases, in a limited part of the projected fan-dome area, either fully inside the dome or expanding over a limited area below which typically a dominant flux concentration resides. The tenth bright point is located in a bipolar loop system without an overlying null point. Conclusions: All bright points in coronal holes and two out of three bright points in quiet Sun regions are seen to reside in regions containing a magnetic null point. An as yet unidentified process(es) generates the brigh points in specific regions of the fan-dome structure. The movies are available at http://www.aanda.org

  12. High-intensity polarized H- ion source for the RHIC SPIN physics

    NASA Astrophysics Data System (ADS)

    Zelenski, A.; Atoian, G.; Raparia, D.; Ritter, J.; Kolmogorov, A.; Davydenko, V.

    2017-08-01

    A novel polarization technique had been successfully implemented for the RHIC polarized H- ion source upgrade to higher intensity and polarization. In this technique a proton beam inside the high magnetic field solenoid is produced by ionization of the atomic hydrogen beam (from external source) in the He-gas ionizer cell. Further proton polarization is produced in the process of polarized electron capture from the optically-pumped Rb vapour. The use of high-brightness primary beam and large cross-sections of charge-exchange cross-sections resulted in production of high intensity H- ion beam of 85% polarization. High beam brightness and polarization resulted in 75% polarization at 23 GeV out of AGS and 60-65% beam polarization at 100-250 GeV colliding beams in RHIC. The status of un-polarized magnetron type (Cs-vapour loaded) BNL source is also discussed.

  13. Skylab floating ice experiment

    NASA Technical Reports Server (NTRS)

    Campbell, W. J. (Principal Investigator); Ramseier, R. O.; Weaver, R. J.; Weeks, W. F.

    1975-01-01

    The author has identified the following significant results. Coupling of the aircraft data with the ground truth observations proved to be highly successful with interesting results being obtained with IR and SLAR passive microwave techniques, and standard photography. Of particular interest were the results of the PMIS system which operated at 10.69 GHz with both vertical and horizontal polarizations. This was the first time that dual polarized images were obtained from floating ice. In both sea and lake ice, it was possible to distinguish a wide variety of thin ice types because of their large differences in brightness temperatures. It was found that the higher brightness temperature was invariably obtained in the vertically polarized mode, and as the age of the ice increases the brightness temperature increases in both polarizations. Associated with this change in age, the difference in temperature was observed as the different polarizations decreased. It appears that the horizontally polarized data is the most sensitive to variations in ice type for both fresh water and sea ice. The study also showed the great amount of information on ice surface roughness and deformation patterns that can be obtained from X-band SLAR observations.

  14. Polarization due to rotational distortion in the bright star Regulus

    NASA Astrophysics Data System (ADS)

    Cotton, Daniel V.; Bailey, Jeremy; Howarth, Ian D.; Bott, Kimberly; Kedziora-Chudczer, Lucyna; Lucas, P. W.; Hough, J. H.

    2017-10-01

    Polarization in stars was first predicted by Chandrasekhar1, who calculated a substantial linear polarization at the stellar limb for a pure electron-scattering atmosphere. This polarization will average to zero when integrated over a spherical star but could be detected if the symmetry was broken, for example, by the eclipse of a binary companion. Nearly 50 years ago, Harrington and Collins2 modelled another way of breaking the symmetry and producing net polarization—the distortion of a rapidly rotating hot star. Here we report the first detection of this effect. Observations of the linear polarization of Regulus, with two different high-precision polarimeters, range from +42 ppm at a wavelength of 741 nm to -22 ppm at 395 nm. The reversal from red to blue is a distinctive feature of rotation-induced polarization. Using a new set of models for the polarization of rapidly rotating stars, we find that Regulus is rotating at 96.5-0.8+0.6% of its critical angular velocity for break-up, and has an inclination greater than 76.5°. The rotation axis of the star is at a position angle of 79.5 ± 0.7°. The conclusions are independent of, but in good agreement with, the results of previously published interferometric observations of Regulus3. The accurate measurement of rotation in early-type stars is important for understanding their stellar environments4 and the course of their evolution5.

  15. High-power laser diodes with high polarization purity

    NASA Astrophysics Data System (ADS)

    Rosenkrantz, Etai; Yanson, Dan; Peleg, Ophir; Blonder, Moshe; Rappaport, Noam; Klumel, Genady

    2017-02-01

    Fiber-coupled laser diode modules employ power scaling of single emitters for fiber laser pumping. To this end, techniques such as geometrical, spectral and polarization beam combining (PBC) are used. For PBC, linear polarization with high degree of purity is important, as any non-perfectly polarized light leads to losses and heating. Furthermore, PBC is typically performed in a collimated portion of the beams, which also cancels the angular dependence of the PBC element, e.g., beam-splitter. However, we discovered that single emitters have variable degrees of polarization, which depends both on the operating current and far-field divergence. We present data to show angle-resolved polarization measurements that correlate with the ignition of high-order modes in the slow-axis emission of the emitter. We demonstrate that the ultimate laser brightness includes not only the standard parameters such as power, emitting area and beam divergence, but also the degree of polarization (DoP), which is a strong function of the latter. Improved slow-axis divergence, therefore, contributes not only to high brightness but also high beam combining efficiency through polarization.

  16. How much material do the radar-bright craters at the Mercurian poles contain?

    NASA Astrophysics Data System (ADS)

    Vilas, Faith; Cobian, Paul S.; Barlow, Nadine G.; Lederer, Susan M.

    2005-12-01

    The depth-to-diameter (d/D) ratios were determined for 12 craters located near the Mercurian north pole that were identified by Harmon et al. (2001, Icarus 149) as having strong depolarized radar echos. We find that the mean d/D value of these radar-bright craters is {2}/{3} the mean d/D value of the general population of non-radar-bright craters in the surrounding north polar region. Previous studies, however, show no difference between d/D values of Mercurian polar and equatorial crater populations, suggesting that no terrain softening which could modify crater structure exists at the Mercurian poles (Barlow et al., 1999, 194, Icarus 141). Thus, the change in d/D is governed by a change in crater depth, probably due to deposition of material inside the crater. The volume of infilling material, including volatiles, in the radar-bright craters is significantly greater than predicted by proposed mechanisms for the emplacement of either water ice or sulfur.

  17. Effects of cloud size and cloud particles on satellite-observed reflected brightness

    NASA Technical Reports Server (NTRS)

    Reynolds, D. W.; Mckee, T. B.; Danielson, K. S.

    1978-01-01

    Satellite observations allowed obtaining data on the visible brightness of cumulus clouds over South Park, Colorado, while aircraft observations were made in cloud to obtain the drop size distributions and liquid water content of the cloud. Attention is focused on evaluating the relationship between cloud brightness, horizontal dimension, and internal microphysical structure. A Monte Carlo cloud model for finite clouds was run using different distributions of drop sizes and numbers, while varying the cloud depth and width to determine how theory would predict what the satellite would view from its given location in space. Comparison of these results to the satellite observed reflectances is presented. Theoretical results are found to be in good agreement with observations. For clouds of optical thickness between 20 and 60, monitoring cloud brightness changes in clouds of uniform depth and variable width gives adequate information about a cloud's liquid water content. A cloud having a 10:1 width to depth ratio is almost reaching its maximum brightness for a specified optical thickness.

  18. Polarized organic light-emitting device on a flexible giant birefringent optical reflecting polarizer substrate.

    PubMed

    Park, Byoungchoo; Park, Chan Hyuk; Kim, Mina; Han, Mi-Young

    2009-06-08

    We present the results of a study of highly linear polarized light emissions from an Organic Light-Emitting Device (OLED) that consisted of a flexible Giant Birefringent Optical (GBO) multilayer polymer reflecting polarizer substrate. Luminous Electroluminescent (EL) emissions over 4,500 cd/m(2) were produced from the polarized OLED with high peak efficiencies in excess of 6 cd/A and 2 lm/W at relatively low operating voltages. The direction of polarization for the emitted EL light corresponded to the passing (ordinary) axis of the GBO-reflecting polarizer. Furthermore, the estimated polarization ratio between the brightness of two linearly polarized EL emissions parallel and perpendicular to the passing axis could be as high as 25 when measured over the whole emitted luminance range.

  19. Three-dimensional vortex-bright solitons in a spin-orbit-coupled spin-1 condensate

    NASA Astrophysics Data System (ADS)

    Gautam, Sandeep; Adhikari, S. K.

    2018-01-01

    We demonstrate stable and metastable vortex-bright solitons in a three-dimensional spin-orbit-coupled three-component hyperfine spin-1 Bose-Einstein condensate (BEC) using numerical solution and variational approximation of a mean-field model. The spin-orbit coupling provides attraction to form vortex-bright solitons in both attractive and repulsive spinor BECs. The ground state of these vortex-bright solitons is axially symmetric for weak polar interaction. For a sufficiently strong ferromagnetic interaction, we observe the emergence of a fully asymmetric vortex-bright soliton as the ground state. We also numerically investigate moving solitons. The present mean-field model is not Galilean invariant, and we use a Galilean-transformed mean-field model for generating the moving solitons.

  20. A NOTE ON THE RELATIVE PHOTOSENSORY EFFECT OF POLARIZED LIGHT

    PubMed Central

    Crozier, W. J.; Mangelsdorf, A. F.

    1924-01-01

    Experiments were made to compare the stimulating effectiveness of vertically and horizontally polarized lights and non-polarized lights of equal intensity upon phototropic movements of the beetle Tetraopes tetraopthalmus; and to compare the effectiveness of two light beams polarized at right angles to one another upon phototropic orientation of the land isopod Cylisticus convexus. Tetraopes is positively, and Cylisticus, negatively phototropic. Tests were also made of the intensities of horizontally and of vertically polarized light required to inhibit stereotropism in larvæ of Tenebrio. Under the conditions of the tests, no certain qualitative effect connected with polarization could be detected. PMID:19872110

  1. Transient bright "halos" on the South Polar Residual Cap of Mars: Implications for mass-balance

    NASA Astrophysics Data System (ADS)

    Becerra, Patricio; Byrne, Shane; Brown, Adrian J.

    2015-05-01

    Spacecraft imaging of Mars' south polar region during mid-southern summer of Mars year 28 (2007) observed bright halo-like features surrounding many of the pits, scarps and slopes of the heavily eroded carbon dioxide ice of the South Polar Residual Cap (SPRC). These features had not been observed before, and have not been observed since. We report on the results of an observational study of these halos, and spectral modeling of the SPRC surface at the time of their appearance. Image analysis was performed using data from MRO's Context Camera (CTX), and High Resolution Imaging Science Experiment (HiRISE), as well as images from Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC). Data from MRO's Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) were used for the spectral analysis of the SPRC ice at the time of the halos. These data were compared with a Hapke reflectance model of the surface to constrain their formation mechanism. We find that the unique appearance of the halos is intimately linked to a near-perihelion global dust storm that occurred shortly before they were observed. The combination of vigorous summertime sublimation of carbon dioxide ice from sloped surfaces on the SPRC and simultaneous settling of dust from the global storm, resulted in a sublimation wind that deflected settling dust particles away from the edges of these slopes, keeping these areas relatively free of dust compared to the rest of the cap. The fact that the halos were not exhumed in subsequent years indicates a positive mass-balance for flat portions of the SPRC in those years. A net accumulation mass-balance on flat surfaces of the SPRC is required to preserve the cap, as it is constantly being eroded by the expansion of the pits and scarps that populate its surface.

  2. A horizontally polarizing liquid trap enhances the tabanid-capturing efficiency of the classic canopy trap.

    PubMed

    Egri, Á; Blahó, M; Száz, D; Kriska, G; Majer, J; Herczeg, T; Gyurkovszky, M; Farkas, R; Horváth, G

    2013-12-01

    Host-seeking female tabanid flies, that need mammalian blood for the development of their eggs, can be captured by the classic canopy trap with an elevated shiny black sphere as a luring visual target. The design of more efficient tabanid traps is important for stock-breeders to control tabanids, since these blood-sucking insects can cause severe problems for livestock, especially for horse- and cattle-keepers: reduced meat/milk production in cattle farms, horses cannot be ridden, decreased quality of hides due to biting scars. We show here that male and female tabanids can be caught by a novel, weather-proof liquid-filled black tray laid on the ground, because the strongly and horizontally polarized light reflected from the black liquid surface attracts water-seeking polarotactic tabanids. We performed field experiments to reveal the ideal elevation of the liquid trap and to compare the tabanid-capturing efficiency of three different traps: (1) the classic canopy trap, (2) the new polarization liquid trap, and (3) the combination of the two traps. In field tests, we showed that the combined trap captures 2.4-8.2 times more tabanids than the canopy trap alone. The reason for the larger efficiency of the combined trap is that it captures simultaneously the host-seeking female and the water-seeking male and female tabanids. We suggest supplementing the traditional canopy trap with the new liquid trap in order to enhance the tabanid-capturing efficiency.

  3. Omnidirectional, circularly polarized, cylindrical microstrip antenna

    NASA Technical Reports Server (NTRS)

    Stanton, Philip H. (Inventor)

    1985-01-01

    A microstrip cylindrical antenna comprised of two concentric subelements on a ground cylinder, a vertically polarized (E-field parallel to the axis of the antenna cylinder) subelement on the inside and a horizontally polarized (E-field perpendicular to the axis) subelement on the outside. The vertical subelement is a wraparound microstrip radiator. A Y-shaped microstrip patch configuration is used for the horizontally polarized radiator that is wrapped 1.5 times to provide radiating edges on opposite sides of the cylindrical antenna for improved azimuthal pattern uniformity. When these subelements are so fed that their far fields are equal in amplitude and phased 90.degree. from each other, a circularly polarized EM wave results. By stacking a plurality of like antenna elements on the ground cylinder, a linear phased array antenna is provided that can be beam steered to the desired elevation angle.

  4. Bright-dark rogue wave in mode-locked fibre laser (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kbashi, Hani; Kolpakov, Stanislav; Martinez, Amós; Mou, Chengbo; Sergeyev, Sergey V.

    2017-05-01

    Bright-Dark Rogue Wave in Mode-Locked Fibre Laser Hani Kbashi1*, Amos Martinez1, S. A. Kolpakov1, Chengbo Mou, Alex Rozhin1, Sergey V. Sergeyev1 1Aston Institute of Photonic Technologies, School of Engineering and Applied Science Aston University, Birmingham, B4 7ET, UK kbashihj@aston.ac.uk , 0044 755 3534 388 Keywords: Optical rogue wave, Bright-Dark rogue wave, rogue wave, mode-locked fiber laser, polarization instability. Abstract: Rogue waves (RWs) are statistically rare localized waves with high amplitude that suddenly appear and disappear in oceans, water tanks, and optical systems [1]. The investigation of these events in optics, optical rogue waves, is of interest for both fundamental research and applied science. Recently, we have shown that the adjustment of the in-cavity birefringence and pump polarization leads to emerge optical RW events [2-4]. Here, we report the first experimental observation of vector bright-dark RWs in an erbium-doped stretched pulse mode-locked fiber laser. The change of induced in-cavity birefringence provides an opportunity to observe RW events at pump power is a little higher than the lasing threshold. Polarization instabilities in the laser cavity result in the coupling between two orthogonal linearly polarized components leading to the emergence of bright-dark RWs. The observed clusters belongs to the class of slow optical RWs because their lifetime is of order of a thousand of laser cavity roundtrip periods. References: 1. D. R. Solli, C. Ropers, P. Koonath,and B. Jalali, Optical rogue waves," Nature, 450, 1054-1057, 2007. 2. S. V. Sergeyev, S. A. Kolpakov, C. Mou, G. Jacobsen, S. Popov, and V. Kalashnikov, "Slow deterministic vector rogue waves," Proc. SPIE 9732, 97320K (2016). 3. S. A. Kolpakov, H. Kbashi, and S. V. Sergeyev, "Dynamics of vector rogue waves in a fiber laser with a ring cavity," Optica, 3, 8, 870, (2016). 5. S. Kolpakov, H. Kbashi, and S. Sergeyev, "Slow optical rogue waves in a unidirectional fiber laser

  5. Some Activities with Polarized Light from a Laptop LCD Screen

    ERIC Educational Resources Information Center

    Fakhruddin, Hasan

    2008-01-01

    The LCD screen of a laptop computer provides a broad, bright, and extended source of polarized light. A number of demonstrations on the properties of polarized light from a laptop computer screens are presented here.

  6. Independent control of differently-polarized waves using anisotropic gradient-index metamaterials

    PubMed Central

    Ma, Hui Feng; Wang, Gui Zhen; Jiang, Wei Xiang; Cui, Tie Jun

    2014-01-01

    We propose a kind of anisotropic gradient-index (GRIN) metamaterials, which can be used to control differently-polarized waves independently. We show that two three- dimensional (3D) planar lenses made of such anisotropic GRIN metamaterials are able to make arbitrary beam deflections for the vertical (or horizontal) polarization but have no response to the horizontal (or vertical) polarization. Then the vertically- and horizontally-polarized waves are separated and controlled independently to deflect to arbitrarily different directions by designing the anisotropic GRIN planar lenses. We make experimental verifications of the lenses using such a special metamaterial, which has both electric and magnetic responses simultaneously to reach approximately equal permittivity and permeability. Hence excellent impedance matching is obtained between the GRIN planar lenses and the air. The measurement results demonstrate good performance on the independent controls of differently-polarized waves, as observed in the numerical simulations. PMID:25231412

  7. Arecibo radar imagery of Mars: II. Chryse-Xanthe, polar caps, and other regions

    NASA Astrophysics Data System (ADS)

    Harmon, John K.; Nolan, Michael C.

    2017-01-01

    other ice processes in the dichotomy boundary region. The first delay-Doppler images of the radar-bright features from the north and south polar icecaps are presented. Both poles show the circular polarization inversion and high reflectivity characteristic of coherent volume backscatter from relatively clean ice. The south polar feature is primarily backscatter from the residual CO2 icecap (with a lesser contribution from the polar layered deposits), whose finite optical depth probably accounts for the feature's strong S/X-band wavelength dependence. Conversely, the north polar radar feature appears to be mostly backscatter from the H2O-ice-rich polar layered deposits rather than from the thin residual H2O cap. The north polar region shows additional radar-bright features from Korolev Crater and a few other outlying circumpolar ice deposits.

  8. Low-frequency polarization measurements of the diffuse radio emission of the galaxy

    NASA Astrophysics Data System (ADS)

    Vinyaikin, E. N.; Paseka, A. M.

    2015-07-01

    Polarization measurements of diffuse Galactic radio emission at 151.5, 198, 217, 237, and 290 MHz have been carried out in the direction of the North Celestial Pole, North Galactic Pole, one region of the North Polar Spur, minimum radio brightness of the Northern sky ( l = 190°, b = 50°), and in the direction l = 147°, b = 9° in the so-called FAN region with enhanced polarization. The results obtained testify to the presence of low spatial frequencies in the angular distribution of the Stokes parameters Q and U of the diffuse Galactic synchrotron emission that are not detectable in interferometric observations. The spectra of the brightness temperature of the polarized component, rotation measures, and intrinsic polarization position angles of the radio emission in the studied regions are presented.

  9. How thick are Mercury's polar water ice deposits?

    NASA Astrophysics Data System (ADS)

    Eke, Vincent R.; Lawrence, David J.; Teodoro, Luís F. A.

    2017-03-01

    An estimate is made of the thickness of the radar-bright deposits in craters near to Mercury's north pole. To construct an objective set of craters for this measurement, an automated crater finding algorithm is developed and applied to a digital elevation model based on data from the Mercury Laser Altimeter onboard the MESSENGER spacecraft. This produces a catalogue of 663 craters with diameters exceeding 4 km, northwards of latitude +55∘ . A subset of 12 larger, well-sampled and fresh polar craters are selected to search for correlations between topography and radar same-sense backscatter cross-section. It is found that the typical excess height associated with the radar-bright regions within these fresh polar craters is (50 ± 35) m. This puts an approximate upper limit on the total polar water ice deposits on Mercury of ∼ 3 × 1015 kg.

  10. Polarization domain wall pulses in a microfiber-based topological insulator fiber laser

    PubMed Central

    Liu, Jingmin; Li, Xingliang; Zhang, Shumin; Zhang, Han; Yan, Peiguang; Han, Mengmeng; Pang, Zhaoguang; Yang, Zhenjun

    2016-01-01

    Topological insulators (TIs), are novel two-dimension materials, which can act as effective saturable absorbers (SAs) in a fiber laser. Moreover, based on the evanescent wave interaction, deposition of the TI on microfiber would create an effective SA, which has combined advantages from the strong nonlinear optical response in TI material together with the sufficiently-long-range interaction length in fiber taper. By using this type of TI SA, various scalar solitons have been obtained in fiber lasers. However, a single mode fiber always exhibits birefringence, and hence can support two orthogonal degenerate modes. Here we investigate experimentally the vector characters of a TI SA fiber laser. Using the saturated absorption and the high nonlinearity of the TI SA, a rich variety of dynamic states, including polarization-locked dark pulses and their harmonic mode locked counterparts, polarization-locked noise-like pulses and their harmonic mode locked counterparts, incoherently coupled polarization domain wall pulses, including bright square pulses, bright-dark pulse pairs, dark pulses and bright square pulse-dark pulse pairs are all observed with different pump powers and polarization states. PMID:27381942

  11. Polarization domain wall pulses in a microfiber-based topological insulator fiber laser

    NASA Astrophysics Data System (ADS)

    Liu, Jingmin; Li, Xingliang; Zhang, Shumin; Zhang, Han; Yan, Peiguang; Han, Mengmeng; Pang, Zhaoguang; Yang, Zhenjun

    2016-07-01

    Topological insulators (TIs), are novel two-dimension materials, which can act as effective saturable absorbers (SAs) in a fiber laser. Moreover, based on the evanescent wave interaction, deposition of the TI on microfiber would create an effective SA, which has combined advantages from the strong nonlinear optical response in TI material together with the sufficiently-long-range interaction length in fiber taper. By using this type of TI SA, various scalar solitons have been obtained in fiber lasers. However, a single mode fiber always exhibits birefringence, and hence can support two orthogonal degenerate modes. Here we investigate experimentally the vector characters of a TI SA fiber laser. Using the saturated absorption and the high nonlinearity of the TI SA, a rich variety of dynamic states, including polarization-locked dark pulses and their harmonic mode locked counterparts, polarization-locked noise-like pulses and their harmonic mode locked counterparts, incoherently coupled polarization domain wall pulses, including bright square pulses, bright-dark pulse pairs, dark pulses and bright square pulse-dark pulse pairs are all observed with different pump powers and polarization states.

  12. Flux and polarization signals of spatially inhomogeneous gaseous exoplanets

    NASA Astrophysics Data System (ADS)

    Karalidi, T.; Stam, D. M.; Guirado, D.

    2013-07-01

    Aims: We present numerically calculated, disk-integrated, spectropolarimetric signals of starlight that is reflected by vertically and horizontally inhomogeneous gaseous exoplanets. We include various spatial features that are present on Solar System's gaseous planets: belts and zones, cyclonic spots, and polar hazes, to test whether such features leave traces in the disk-integrated fux and polarization signals. Methods: Broadband flux and polarization signals of starlight that is reflected by gaseous exoplanets are calculated using an efficient, adding-doubling radiative transfer code, that fully includes single and multiple scattering and polarization. The planetary model atmospheres are vertically inhomogeneous and can be horizontally inhomogeneous, and contain gas molecules and/or cloud and/or aerosol particles. Results: The broadband flux and polarization signals are sensitive to cloud top pressures, although in the presence of local pressure differences, such as in belts and clouds, the flux and polarization phase functions have similar shapes as those of horizontally homogeneous planets. Fitting flux phase functions of a planet with belts and zones using a horizontally homogeneous planet could theoretically yield cloud top pressures that differ by a few hundred mbar from those derived from fitting polarization phase functions. In practice, however, observational errors and uncertainties in cloud properties would make such a fit unreliable. A cyclonic spot like Jupiter's Great Red Spot, covering a few percent of the disk, located in equatorial regions, and rotating in and out of the observer's view yields a temporal variation of a few percent in the broadband flux and a few percent in the degree of polarization. Polar hazes leave strong traces in the polarization of reflected starlight in spatially resolved observations, especially seen at phase angles near 90°. Integrated across the planetary disk, polar hazes that cover only part of the planetary disk

  13. Influence of interplanetary magnetic field and solar wind on auroral brightness in different regions

    NASA Astrophysics Data System (ADS)

    Yang, Y. F.; Lu, J. Y.; Wang, J.-S.; Peng, Z.; Zhou, L.

    2013-01-01

    Abstract<p label="1">By integrating and averaging the auroral <span class="hlt">brightness</span> from <span class="hlt">Polar</span> Ultraviolet Imager auroral images, which have the whole auroral ovals, and combining the observation data of interplanetary magnetic field (IMF) and solar wind from NASA Operating Missions as a Node on the Internet (OMNI), we investigate the influence of IMF and solar wind on auroral activities, and analyze the separate roles of the solar wind dynamic pressure, density, and velocity on aurora, respectively. We statistically analyze the relations between the interplanetary conditions and the auroral <span class="hlt">brightness</span> in dawnside, dayside, duskside, and nightside. It is found that the three components of the IMF have different effects on the auroral <span class="hlt">brightness</span> in the different regions. Different from the nightside auroral <span class="hlt">brightness</span>, the dawnside, dayside, and duskside auroral <span class="hlt">brightness</span> are affected by the IMF Bx, and By components more significantly. The IMF Bx and By components have different effects on these three regional auroral <span class="hlt">brightness</span> under the opposite <span class="hlt">polarities</span> of the IMF Bz. As expected, the nightside aurora is mainly affected by the IMF Bz, and under southward IMF, the larger the |Bz|, the brighter the nightside aurora. The IMF Bx and By components have no visible effects. On the other hand, it is also found that the aurora is not intensified singly with the increase of the solar wind dynamic pressure: when only the dynamic pressure is high, but the solar wind velocity is not very fast, the aurora will not necessarily be intensified significantly. These results can be used to qualitatively predict the auroral activities in different regions for various interplanetary conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptCo.412....1P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptCo.412....1P"><span>Electromagnetic near-field coupling induced <span class="hlt">polarization</span> conversion and asymmetric transmission in plasmonic metasurfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peng, Yu-Xiang; Wang, Kai-Jun; He, Meng-Dong; Luo, Jian-Hua; Zhang, Xin-Min; Li, Jian-Bo; Tan, Shi-Hua; Liu, Jian-Qiang; Hu, Wei-Da; Chen, Xiaoshuang</p> <p>2018-04-01</p> <p>In this paper, we demonstrate the effect of <span class="hlt">polarization</span> conversion in a plasmonic metasurface structure, in which each unit cell consists of a metal bar and four metal split-ring resonators (SRRs). Such effect is attributed to the fact that the dark plasmon mode of SRRs (bar), which radiates cross-<span class="hlt">polarized</span> component, is induced by the <span class="hlt">bright</span> plasmon mode of bar (SRRs) due to the electromagnetic near-field coupling between bar and SRRs. We find that there are two ways to achieve a large cross-<span class="hlt">polarized</span> component in our proposed metasurface structure. The first way is realized when the dark plasmon mode of bar (SRRs) is in resonance, while at this time the <span class="hlt">bright</span> plasmon mode of SRRs (bar) is not at resonant state. The second way is realized when the <span class="hlt">bright</span> plasmon mode of SRRs (bar) is resonantly excited, while the dark plasmon mode of bar (SRRs) is at nonresonant state. It is also found that the linearly <span class="hlt">polarized</span> light can be rotated by 56.50 after propagation through the metasurface structure. Furthermore, our proposed metasurface structure exhibits an asymmetric transmission for circularly <span class="hlt">polarized</span> light. Our findings take a further step in developing integrated metasurface-based photonics devices for <span class="hlt">polarization</span> manipulation and modulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19930040351&hterms=SSM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DSSM','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19930040351&hterms=SSM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DSSM"><span>Atmospheric effects on SMMR and SSM/I 37 GHz <span class="hlt">polarization</span> difference over the Sahel</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Choudhury, B. J.; Major, E. R.; Smith, E. A.; Becker, F.</p> <p>1992-01-01</p> <p>The atmospheric effects on the difference of vertically and <span class="hlt">horizontally</span> <span class="hlt">polarized</span> <span class="hlt">brightness</span> temperatures, Delta(T) observed at 37 GHz frequency of the SMMR on board the Nimbus-7 satellite and SSM/I on board the DMSP-F8 satellite are studied over two 2.5 by 2.5 deg regions within the Sahel and Sudan zones of Africa from January 1985 to December 1986 through radiative transfer analysis using surface temperature, atmospheric water vapor, and cloud optical thickness. It is found that atmospheric effects alone cannot explain the observed temporal variation of Delta(T), although the atmosphere introduces important modulations on the observed seasonal variations of Delta(T) due to rather significant seasonal variation of precipitable water vapor. These Delta(T) data should be corrected for atmospheric effects before any quantitative analysis of land surface change over the Sahel and Sudan zones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8798E..0OG','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8798E..0OG"><span>An ultra-<span class="hlt">bright</span> white LED based non-contact skin cancer imaging system with <span class="hlt">polarization</span> control</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Günther, A.; Basu, C.; Roth, B.; Meinhardt-Wollweber, M.</p> <p>2013-06-01</p> <p>Early detection and excision of melanoma skin cancer is crucial for a successful therapy. Dermoscopy in direct contact with the skin is routinely used for inspection, but screening is time consuming for high-risk patients with a large number of nevi. Features like symmetry, border, color and most importantly changes like growth or depigmentation of a nevus may indicate malignancy. We present a non-contact remote imaging system for human melanocytic nevi with homogenous illumination by an ultra-<span class="hlt">bright</span> white LED. The advantage compared to established dermoscopy systems requiring direct skin contact is that deformation of raised nevi is avoided and full-body scans of the patients may time-efficiently be obtained while they are in a lying, comfortable position. This will ultimately allow for automated screening in the future. In addition, calibration of true color rendering, which is essential for distinguishing between benign and malignant lesions and to ensure reproducibility and comparison between individual check-ups in order to follow nevi evolution is implemented as well as suppression of specular highlights on the skin surface by integration of <span class="hlt">polarizing</span> filters. Important features of the system which will be crucial for future integration into automated systems are the possibility to record images without artifacts in combination with short exposure times which both reduce image blurring caused by patient motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA02880&hterms=Polarized&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D60%26Ntt%3DPolarized','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA02880&hterms=Polarized&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D60%26Ntt%3DPolarized"><span><span class="hlt">Polarized</span> Light from Jupiter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2001-01-01</p> <p><p/>These images taken through the wide angle camera near closest approach in the deep near-infrared methane band, combined with filters which sense electromagnetic radiation of orthogonal <span class="hlt">polarization</span>, show that the light from the poles is <span class="hlt">polarized</span>. That is, the poles appear <span class="hlt">bright</span> in one image, and dark in the other. <span class="hlt">Polarized</span> light is most readily scattered by aerosols. These images indicate that the aerosol particles at Jupiter's poles are small and likely consist of aggregates of even smaller particles, whereas the particles at the equator and covering the Great Red Spot are larger. Images like these will allow scientists to ascertain the distribution, size and shape of aerosols, and consequently, the distribution of heat, in Jupiter's atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA02301.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA02301.html"><span>Defrosting <span class="hlt">Polar</span> Dunes -- "The Snow Leopard"</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2000-05-16</p> <p>The patterns created by dark spots on defrosting south <span class="hlt">polar</span> dunes are often strange and beautiful. This picture, which the Mars Orbiter Camera team has dubbed, "the snow leopard," shows a dune field located at 61.5°S, 18.9°W, as it appeared on July 1, 1999. The spots are areas where dark sand has been exposed from beneath <span class="hlt">bright</span> frost as the south <span class="hlt">polar</span> winter cap begins to retreat. Many of the spots have a diffuse, <span class="hlt">bright</span> ring around them this is thought to be fresh frost that was re-precipitated after being removed from the dark spot. The spots seen on defrosting <span class="hlt">polar</span> dunes are a new phenomenon that was not observed by previous spacecraft missions to Mars. Thus, there is much about these features that remains unknown. For example, no one yet knows why the dunes become defrosted by forming small spots that grow and grow over time. No one knows for sure if the <span class="hlt">bright</span> rings around the dark spots are actually composed of re-precipitated frost. And no one knows for sure why some dune show spots that appear to be "lined-up" (as they do in the picture shown here). This Mars Global Surveyor Mars Orbiter Camera image is illuminated from the upper left. North is toward the upper right. The scale bar indicates a distance of 200 meters (656 feet). http://photojournal.jpl.nasa.gov/catalog/PIA02301</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930001663','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930001663"><span>Morning-evening differences in global and regional oceanic precipitation as observed by the SSM/I</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Petty, Grant W.; Katsaros, Kristina B.</p> <p>1992-01-01</p> <p>For the present preliminary analysis of oceanic rainfall statistics, global oceanic SSM/I data were simply scanned for pixels which exhibited a 37 GHz <span class="hlt">polarization</span> difference (vertically <span class="hlt">polarized</span> <span class="hlt">brightness</span> temperatures minus <span class="hlt">horizontally</span> <span class="hlt">polarized</span> <span class="hlt">brightness</span> temperatures) of less than 15 K. Such a low <span class="hlt">polarization</span> difference over the open ocean is a completely unambiguous indication of moderate to intense precipitation. Co-located <span class="hlt">brightness</span> temperatures from all seven channels of the SSM/I were saved for each pixel so identified. Bad scans and geographically mislocated block of data were objectively identified and removed from the resulting data base. We collected global oceanic rainfall data for two time periods, each one month in length. The first period (20 July-19 August 1987) coincides with the peak of the Northern Hemisphere summer. The second period (13 January-12 February 1988) coincides with the Northern Hemisphere winter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29041617','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29041617"><span><span class="hlt">Polarization</span> independent subtractive color printing based on ultrathin hexagonal nanodisk-nanohole hybrid structure arrays.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhao, Jiancun; Yu, Xiaochang; Yang, Xiaoming; Xiang, Quan; Duan, Huigao; Yu, Yiting</p> <p>2017-09-18</p> <p>Structural color printing based on plasmonic metasurfaces has been recognized as a promising alternative to the conventional dye colorants, though the color <span class="hlt">brightness</span> and <span class="hlt">polarization</span> tolerance are still a great challenge for practical applications. In this work, we report a novel plasmonic metasurface for subtractive color printing employing the ultrathin hexagonal nanodisk-nanohole hybrid structure arrays. Through both the experimental and numerical investigations, the subtractive color thus generated taking advantages of extraordinary low transmission (ELT) exhibits high <span class="hlt">brightness</span>, <span class="hlt">polarization</span> independence and wide color tunability by varying key geometrical parameters. In addition, other regular patterns including square, pentagonal and circular shapes are also surveyed, and reveal a high color <span class="hlt">brightness</span>, wide gamut and <span class="hlt">polarization</span> independence as well. These results indicate that the demonstrated plasmonic metasurface has various potential applications in high-definition displays, high-density optical data storage, imaging and filtering technologies.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRE..123..666C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRE..123..666C"><span>Investigating Mercury's South <span class="hlt">Polar</span> Deposits: Arecibo Radar Observations and High-Resolution Determination of Illumination Conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chabot, Nancy L.; Shread, Evangela E.; Harmon, John K.</p> <p>2018-02-01</p> <p>There is strong evidence that Mercury's <span class="hlt">polar</span> deposits are water ice hosted in permanently shadowed regions. In this study, we present new Arecibo radar observations of Mercury's south pole, which reveal numerous radar-<span class="hlt">bright</span> deposits and substantially increase the radar imaging coverage. We also use images from MESSENGER's full mission to determine the illumination conditions of Mercury's south <span class="hlt">polar</span> region at the same spatial resolution as the north <span class="hlt">polar</span> region, enabling comparisons between the two poles. The area of radar-<span class="hlt">bright</span> deposits in Mercury's south is roughly double that found in the north, consistent with the larger permanently shadowed area in the older, cratered terrain at the south relative to the younger smooth plains at the north. Radar-<span class="hlt">bright</span> features are strongly associated with regions of permanent shadow at both poles, consistent with water ice being the dominant component of the deposits. However, both of Mercury's <span class="hlt">polar</span> regions show that roughly 50% of permanently shadowed regions lack radar-<span class="hlt">bright</span> deposits, despite some of these locations having thermal environments that are conducive to the presence of water ice. The observed uneven distribution of water ice among Mercury's <span class="hlt">polar</span> cold traps may suggest that the source of Mercury's water ice was not a steady, regular process but rather that the source was an episodic event, such as a recent, large impact on the innermost planet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980219468','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980219468"><span><span class="hlt">Bright</span> Points and Subflares in UV Lines and in X-Rays</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rovira, M.; Schmieder, B.; Demoulin, P.; Simnett, G. M.; Hagyard, M. J.; Reichmann, E.; Tandberg-Hanssen, E.</p> <p>1998-01-01</p> <p>We have analysed an active region which was observed in Halpha (MSDP), UV lines (SMM/UVSP), and in X rays (SMM/HXIS). In this active region there were only a few subflares and many small <span class="hlt">bright</span> points visible in UV and in X rays. Using an extrapolation based on the Fourier transform we have computed magnetic field lines connecting different photospheric magnetic <span class="hlt">polarities</span> from ground-based magnetograms. Along the magnetic inversion lines we find 2 different zones: 1. a high shear region (less than 70 degrees) where subflares occur 2. a low shear region along the magnetic inversion line where UV <span class="hlt">bright</span> points are observed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29396620','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29396620"><span><span class="hlt">Polarization</span>-Insensitive Surface Plasmon <span class="hlt">Polarization</span> Electro-Absorption Modulator Based on Epsilon-Near-Zero Indium Tin Oxide.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jin, Lin; Wen, Long; Liang, Li; Chen, Qin; Sun, Yunfei</p> <p>2018-02-03</p> <p>CMOS-compatible plasmonic modulators operating at the telecom wavelength are significant for a variety of on-chip applications. Relying on the manipulation of the transverse magnetic (TM) mode excited on the metal-dielectric interface, most of the previous demonstrations are designed to response only for specific <span class="hlt">polarization</span> state. In this case, it will lead to a high <span class="hlt">polarization</span> dependent loss, when the <span class="hlt">polarization</span>-sensitive modulator integrates to a fiber with random <span class="hlt">polarization</span> state. Herein, we propose a plasmonic modulator utilizing a metal-oxide indium tin oxide (ITO) wrapped around the silicon waveguide and investigate its optical modulation ability for both the vertical and <span class="hlt">horizontal</span> <span class="hlt">polarized</span> guiding light by tuning electro-absorption of ITO with the field-induced carrier injection. The electrically biased modulator with electron accumulated at the ITO/oxide interface allows for epsilon-near-zero (ENZ) mode to be excited at the top or lateral portion of the interface depending on the <span class="hlt">polarization</span> state of the guiding light. Because of the high localized feature of ENZ mode, efficient electro-absorption can be achieved under the "OFF" state of the device, thus leading to large extinction ratio (ER) for both <span class="hlt">polarizations</span> in our proposed modulator. Further, the <span class="hlt">polarization</span>-insensitive modulation is realized by properly tailoring the thickness of oxide in two different stacking directions and therefore matching the ER values for device operating at vertical and <span class="hlt">horizontal</span> <span class="hlt">polarized</span> modes. For the optimized geometry configuration, the difference between the ER values of two <span class="hlt">polarization</span> modes, i.e., the ΔER, as small as 0.01 dB/μm is demonstrated and, simultaneously with coupling efficiency above 74%, is obtained for both <span class="hlt">polarizations</span> at a wavelength of 1.55 μm. The proposed plasmonic-combined modulator has a potential application in guiding and processing of light from a fiber with a random <span class="hlt">polarization</span> state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NRL....13...39J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NRL....13...39J"><span><span class="hlt">Polarization</span>-Insensitive Surface Plasmon <span class="hlt">Polarization</span> Electro-Absorption Modulator Based on Epsilon-Near-Zero Indium Tin Oxide</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, Lin; Wen, Long; Liang, Li; Chen, Qin; Sun, Yunfei</p> <p>2018-02-01</p> <p>CMOS-compatible plasmonic modulators operating at the telecom wavelength are significant for a variety of on-chip applications. Relying on the manipulation of the transverse magnetic (TM) mode excited on the metal-dielectric interface, most of the previous demonstrations are designed to response only for specific <span class="hlt">polarization</span> state. In this case, it will lead to a high <span class="hlt">polarization</span> dependent loss, when the <span class="hlt">polarization</span>-sensitive modulator integrates to a fiber with random <span class="hlt">polarization</span> state. Herein, we propose a plasmonic modulator utilizing a metal-oxide indium tin oxide (ITO) wrapped around the silicon waveguide and investigate its optical modulation ability for both the vertical and <span class="hlt">horizontal</span> <span class="hlt">polarized</span> guiding light by tuning electro-absorption of ITO with the field-induced carrier injection. The electrically biased modulator with electron accumulated at the ITO/oxide interface allows for epsilon-near-zero (ENZ) mode to be excited at the top or lateral portion of the interface depending on the <span class="hlt">polarization</span> state of the guiding light. Because of the high localized feature of ENZ mode, efficient electro-absorption can be achieved under the "OFF" state of the device, thus leading to large extinction ratio (ER) for both <span class="hlt">polarizations</span> in our proposed modulator. Further, the <span class="hlt">polarization</span>-insensitive modulation is realized by properly tailoring the thickness of oxide in two different stacking directions and therefore matching the ER values for device operating at vertical and <span class="hlt">horizontal</span> <span class="hlt">polarized</span> modes. For the optimized geometry configuration, the difference between the ER values of two <span class="hlt">polarization</span> modes, i.e., the ΔER, as small as 0.01 dB/μm is demonstrated and, simultaneously with coupling efficiency above 74%, is obtained for both <span class="hlt">polarizations</span> at a wavelength of 1.55 μm. The proposed plasmonic-combined modulator has a potential application in guiding and processing of light from a fiber with a random <span class="hlt">polarization</span> state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16855654','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16855654"><span>Celestial <span class="hlt">polarization</span> patterns during twilight.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cronin, Thomas W; Warrant, Eric J; Greiner, Birgit</p> <p>2006-08-01</p> <p>Scattering of sunlight produces patterns of partially linearly <span class="hlt">polarized</span> light in the sky throughout the day, and similar patterns appear at night when the Moon is <span class="hlt">bright</span>. We studied celestial <span class="hlt">polarization</span> patterns during the period of twilight, when the Sun is below the horizon, determining the degree and orientation of the <span class="hlt">polarized</span>-light field and its changes before sunrise and after sunset. During twilight, celestial <span class="hlt">polarized</span> light occurs in a wide band stretching perpendicular to the location of the hidden Sun and reaching typical degrees of <span class="hlt">polarization</span> near 80% at wavelengths >600 nm. In the tropics, this pattern appears approximately 1 h before local sunrise or disappears approximately 1 h after local sunset (within 10 min. after the onset of astronomical twilight at dawn, or before its end at dusk) and extends with little change through the entire twilight period.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA619293','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA619293"><span>Generation of <span class="hlt">Bright</span> Phase-matched Circularly-<span class="hlt">polarized</span> Extreme Ultraviolet High Harmonics</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-12-08</p> <p>circularly-<span class="hlt">polarized</span> laser pulses field-ionize a gas in a hollow - core waveguide. We use this new light source for magnetic circular dichroism...<span class="hlt">polarized</span> with opposite helicity in a gas-filled hollow waveguide (see Supplementary Section 6 for details on the important features of this source...mJ/pulse) driving lasers are focused into a 150-µm-diameter, 2-cm-long gas-filled hollow waveguide using lenses with focal lengths of 50 cm and 75 cm</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070032041','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070032041"><span>The Physical Nature of <span class="hlt">Polar</span> Broad Absorption Line Quasars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ghost, Kajal; Punsly, Brian</p> <p>2007-01-01</p> <p>It has been shown based on radio variability arguments that some BALQSOs (broad absorption line quasars) are viewed along the <span class="hlt">polar</span> axis (o rthogonal to accretion disk) in the recent article of Zhou et a. Thes e arguments are based on the <span class="hlt">brightness</span> temperature, T(sub b) exceedi ng 10(exp 12) K which leads to the well-known inverse Compton catastr ophe unless the radio jet is relativistic and is viewed along its axi s. In this letter, we expand the Zhou et al sample of <span class="hlt">polar</span> BALQSOs u sing their techniques applied to SDSS DR5. In the process, we clarify a mistake in their calculation of <span class="hlt">brightness</span> temperature. The expanded sample of high T(sub b) BALQSOS, has an inordinately large fraction of LoBALQSOs (low ionization BALQSOs). We consider this an important clue to understanding the nature of the <span class="hlt">polar</span> BALQSOs. This is expec ted in the <span class="hlt">polar</span> BALQSO analytical/numerical models of Punsly that pr edicted that LoBALQSOs occur when the line of sight is very close to the <span class="hlt">polar</span> axis, where the outflow density is the highest.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=earths+AND+orbit&pg=6&id=EJ278584','ERIC'); return false;" href="https://eric.ed.gov/?q=earths+AND+orbit&pg=6&id=EJ278584"><span><span class="hlt">Polar</span> Views of Planet Earth.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brochu, Michel</p> <p>1983-01-01</p> <p>In August, 1981, National Aeronautics and Space Administration launched Dynamics Explorer 1 into <span class="hlt">polar</span> orbit equipped with three cameras built to view the Northern Lights. The cameras can photograph aurora borealis' faint light without being blinded by the earth's <span class="hlt">bright</span> dayside. Photographs taken by the satellite are provided. (JN)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptCo.414...29Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptCo.414...29Y"><span>The <span class="hlt">bright-bright</span> and <span class="hlt">bright</span>-dark mode coupling-based planar metamaterial for plasmonic EIT-like effect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yu, Wei; Meng, Hongyun; Chen, Zhangjie; Li, Xianping; Zhang, Xing; Wang, Faqiang; Wei, Zhongchao; Tan, Chunhua; Huang, Xuguang; Li, Shuti</p> <p>2018-05-01</p> <p>In this paper, we propose a novel planar metamaterial structure for the electromagnetically induced transparency (EIT)-like effect, which consists of a split-ring resonator (SRR) and a pair of metal strips. The simulated results indicate that a single transparency window can be realized in the symmetry situation, which originates from the <span class="hlt">bright-bright</span> mode coupling. Further, a dual-band EIT-like effect can be achieved in the asymmetry situation, which is due to the <span class="hlt">bright-bright</span> mode coupling and <span class="hlt">bright</span>-dark mode coupling, respectively. Different EIT-like effect can be simultaneously achieved in the proposed structure with the different situations. It is of certain significance for the study of EIT-like effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA01058&hterms=Dark+web&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DDark%2Bweb','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA01058&hterms=Dark+web&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DDark%2Bweb"><span><span class="hlt">Bright</span> and Dark Slopes on Ganymede</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1997-01-01</p> <p>Ridges on the edge of Ganymede's north <span class="hlt">polar</span> cap show <span class="hlt">bright</span> east-facing slopes and dark west-facing slopes with troughs of darker material below the larger ridges. North is to the top. The <span class="hlt">bright</span> slopes may be due to grain size differences, differences in composition between the original surface and the underlying material, frost deposition, or illumination effects. The large 2.4 kilometer (1.5 mile) diameter crater in this image shows frost deposits located on the north-facing rim slope, away from the sun. A smaller 675 meter (2200 foot) diameter crater in the center of the image is surrounded by a <span class="hlt">bright</span> deposit which may be ejecta from the impact. Ejecta deposits such as this are uncommon for small craters on Ganymede. This image measures 18 by 19 kilometers (11 by 12 miles) and has a resolution of 45 meters (148 feet) per pixel. NASA's Galileo spacecraft obtained this image on September 6, 1996 during its second orbit around Jupiter.<p/>The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).<p/>This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA07354&hterms=polygons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dpolygons','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA07354&hterms=polygons&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dpolygons"><span><span class="hlt">Polar</span> Polygons</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2005-01-01</p> <p><p/>13 February 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows polygons formed in ice-rich material in the north <span class="hlt">polar</span> region of Mars. The <span class="hlt">bright</span> surfaces in this image are covered by a thin water ice frost. <p/> <i>Location near</i>: 79.8oN, 344.8oW <i>Image width</i>: 1.5 km (1.9 mi) <i>Illumination from</i>: lower left <i>Season</i>: Northern Summer</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20000110455&hterms=geology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dgeology','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20000110455&hterms=geology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dgeology"><span>South <span class="hlt">Polar</span> Region of Mars: Topography and Geology</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schenk, P. M.; Moore, J. M.</p> <p>1999-01-01</p> <p>The <span class="hlt">polar</span> layered deposits of Mars represent potentially important volatile reservoirs and tracers for the planet's geologically recent climate history. Unlike the north <span class="hlt">polar</span> cap, the uppermost surface of the <span class="hlt">bright</span> residual south <span class="hlt">polar</span> deposit is probably composed of carbon dioxide ice. It is unknown whether this ice extends through the entire thickness of the deposit. The Mars <span class="hlt">Polar</span> Lander (MPL), launched in January 1999, is due to arrive in December 1999 to search for water and carbon dioxide on layered deposits near the south pole (SP) of Mars. Additional information is contained in the original extended abstract.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19780030814&hterms=bright+hour&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbright%2Bhour','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19780030814&hterms=bright+hour&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbright%2Bhour"><span><span class="hlt">Bright</span> X-ray arcs and the emergence of solar magnetic flux</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chapman, G. A.; Broussard, R. M.</p> <p>1977-01-01</p> <p>The Skylab S-056 and S-082A experiments and ground-based magnetograms have been used to study the role of <span class="hlt">bright</span> X-ray arcs and the emergence of solar magnetic flux in the McMath region 12476. The S-056 X-ray images show a system of one or sometimes two <span class="hlt">bright</span> arcs within a diffuse emitting region. The arcs seem to directly connect regions of opposite magnetic <span class="hlt">polarity</span> in the photosphere. Magnetograms suggest the possible emergence of a magnetic flux. The width of the main arc is approximately 6 arcsec when most clearly defined, and the length is approximately 30-50 arcsec. Although the arc system is observed to vary in <span class="hlt">brightness</span> over a period exceeding 24 hours, it remains fixed in orientation. The temperature of the main arc is approximately 3 x 10 to the 6th K. It is suggested that merging magnetic fields may provide the primary energy source, perhaps accompanied by resistive heating from a force-free current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PASP..118..489K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PASP..118..489K"><span>A Review of Optical Sky <span class="hlt">Brightness</span> and Extinction at Dome C, Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kenyon, S. L.; Storey, J. W. V.</p> <p>2006-03-01</p> <p>The recent discovery of exceptional seeing conditions at Dome C, Antarctica, raises the possibility of constructing an optical observatory there with unique capabilities. However, little is known from an astronomer's perspective about the optical sky <span class="hlt">brightness</span> and extinction at Antarctic sites. We review the contributions to sky <span class="hlt">brightness</span> at high-latitude sites and calculate the amount of usable dark time at Dome C. We also explore the implications of the limited sky coverage of high-latitude sites and review optical extinction data from the South Pole. Finally, we examine the proposal of Baldry & Bland-Hawthorn to extend the amount of usable dark time through the use of <span class="hlt">polarizing</span> filters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3049001','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3049001"><span>Navigation by light <span class="hlt">polarization</span> in clear and turbid waters</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lerner, Amit; Sabbah, Shai; Erlick, Carynelisa; Shashar, Nadav</p> <p>2011-01-01</p> <p>Certain terrestrial animals use sky <span class="hlt">polarization</span> for navigation. Certain aquatic species have also been shown to orient according to a <span class="hlt">polarization</span> stimulus, but the correlation between underwater <span class="hlt">polarization</span> and Sun position and hence the ability to use underwater <span class="hlt">polarization</span> as a compass for navigation is still under debate. To examine this issue, we use theoretical equations for per cent <span class="hlt">polarization</span> and electric vector (e-vector) orientation that account for the position of the Sun, refraction at the air–water interface and Rayleigh single scattering. The <span class="hlt">polarization</span> patterns predicted by these theoretical equations are compared with measurements conducted in clear and semi-turbid coastal sea waters at 2 m and 5 m depth over sea floors of 6 m and 28 m depth. We find that the per cent <span class="hlt">polarization</span> is correlated with the Sun's elevation only in clear waters. We furthermore find that the maximum value of the e-vector orientation angle equals the angle of refraction only in clear waters, in the <span class="hlt">horizontal</span> viewing direction, over the deeper sea floor. We conclude that navigation by use of underwater <span class="hlt">polarization</span> is possible under restricted conditions, i.e. in clear waters, primarily near the <span class="hlt">horizontal</span> viewing direction, and in locations where the sea floor has limited effects on the light's <span class="hlt">polarization</span>. PMID:21282170</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=257635','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=257635"><span>L band <span class="hlt">brightness</span> temperature observations over a corn canopy during the entire growth cycle</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>During a field campaign covering the 2002 corn growing season, a dual <span class="hlt">polarized</span> tower mounted L-band (1.4 GHz) radiometer (LRAD) provided <span class="hlt">brightness</span> temperature (T¬B) measurements at preset intervals, incidence and azimuth angles. These radiometer measurements were supported by an extensive characte...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017yCat..17890135W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017yCat..17890135W"><span>VizieR Online Data Catalog: Gamma-ray <span class="hlt">bright</span> blazars spectrophotometry (Williamson+, 2014)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Williamson, K. E.; Jorstad, S. G.; Marscher, A. P.; Larionov, V. M.; Smith, P. S.; Agudo, I.; Arkharov, A. A.; Blinov, D. A.; Casadio, C.; Efimova, N. V.; Gomez, J. L.; Hagen-Thorn, V. A.; Joshi, M.; Konstantinova, T. S.; Kopatskaya, E. N.; Larionova, E. G.; Larionova, L. V.; Malmrose, M. P.; McHardy, I. M.; Molina, S. N.; Morozova, D. A.; Schmidt, G. D.; Taylor, B. W.; Troitsky, I. S.</p> <p>2017-03-01</p> <p>Since 2007, we have been collecting multi-waveband fluxes, <span class="hlt">polarization</span> measurements, and radio images of blazars to provide the data for understanding the physics of the jets (see, e.g., Marscher 2012, arXiv:1201.5402). This study includes 28 of the original 30 objects selected for the monitoring campaign, confirmed as γ-ray sources by EGRET (Energetic γ-Ray Experiment Telescope) on the Compton Gamma Ray Observatory, have an R-band <span class="hlt">brightness</span> exceeding 18 mag (<span class="hlt">bright</span> enough for optical <span class="hlt">polarization</span> measurements at a 1-2 m class optical telescope without needing excessive amounts of telescope time), exceed 0.5 Jy at 43 GHz, and have a declination accessible to the collaboration's observatories (> - 30°). Three additional BL Lacs (1055+018, 1308+326, and 1749+096) and two FSRQs (3C345 and 3C446) included in this analysis were among those added when they were detected as γ-ray sources by the Fermi LAT (Abdo et al. 2009, J/ApJ/700/597). (4 data files).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...591A.119A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...591A.119A"><span>Discovery of a complex linearly <span class="hlt">polarized</span> spectrum of Betelgeuse dominated by depolarization of the continuum</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aurière, M.; López Ariste, A.; Mathias, P.; Lèbre, A.; Josselin, E.; Montargès, M.; Petit, P.; Chiavassa, A.; Paletou, F.; Fabas, N.; Konstantinova-Antova, R.; Donati, J.-F.; Grunhut, J. H.; Wade, G. A.; Herpin, F.; Kervella, P.; Perrin, G.; Tessore, B.</p> <p>2016-06-01</p> <p>Context. Betelgeuse is an M supergiant that harbors spots and giant granules at its surface and presents linear <span class="hlt">polarization</span> of its continuum. Aims: We have previously discovered linear <span class="hlt">polarization</span> signatures associated with individual lines in the spectra of cool and evolved stars. Here, we investigate whether a similar linearly <span class="hlt">polarized</span> spectrum exists for Betelgeuse. Methods: We used the spectropolarimeter Narval, combining multiple polarimetric sequences to obtain high signal-to-noise ratio spectra of individual lines, as well as the least-squares deconvolution (LSD) approach, to investigate the presence of an averaged linearly <span class="hlt">polarized</span> profile for the photospheric lines. Results: We have discovered the existence of a linearly <span class="hlt">polarized</span> spectrum for Betelgeuse, detecting a rather strong signal (at a few times 10-4 of the continuum intensity level), both in individual lines and in the LSD profiles. Studying its properties and the signal observed for the resonant Na I D lines, we conclude that we are mainly observing depolarization of the continuum by the absorption lines. The linear <span class="hlt">polarization</span> of the Betelgeuse continuum is due to the anisotropy of the radiation field induced by <span class="hlt">brightness</span> spots at the surface and Rayleigh scattering in the atmosphere. We have developed a geometrical model to interpret the observed <span class="hlt">polarization</span>, from which we infer the presence of two <span class="hlt">brightness</span> spots and their positions on the surface of Betelgeuse. We show that applying the model to each velocity bin along the Stokes Q and U profiles allows the derivation of a map of the <span class="hlt">bright</span> spots. We use the Narval linear <span class="hlt">polarization</span> observations of Betelgeuse obtained over a period of 1.4 yr to study the evolution of the spots and of the atmosphere. Conclusions: Our study of the linearly <span class="hlt">polarized</span> spectrum of Betelgeuse provides a novel method for studying the evolution of <span class="hlt">brightness</span> spots at its surface and complements quasi-simultaneous observations obtained with PIONIER at the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014A%26A...564A.104S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014A%26A...564A.104S"><span>Proper <span class="hlt">horizontal</span> photospheric flows in a filament channel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schmieder, B.; Roudier, T.; Mein, N.; Mein, P.; Malherbe, J. M.; Chandra, R.</p> <p>2014-04-01</p> <p>Context. An extended filament in the central part of the active region NOAA 11106 crossed the central meridian on Sept. 17, 2010 in the southern hemisphere. It has been observed in Hα with the THEMIS telescope in the Canary Islands and in 304 Å with the EUV imager (AIA) onboard the Solar Dynamic Observatory (SDO). Counterstreaming along the Hα threads and <span class="hlt">bright</span> moving blobs (jets) along the 304 Å filament channel were observed during 10 h before the filament erupted at 17:03 UT. Aims: The aim of the paper is to understand the coupling between magnetic field and convection in filament channels and relate the <span class="hlt">horizontal</span> photospheric motions to the activity of the filament. Methods: An analysis of the proper photospheric motions using SDO/HMI continuum images with the new version of the coherent structure tracking (CST) algorithm developed to track granules, as well as the large scale photospheric flows, was performed for three hours. Using corks, we derived the passive scalar points and produced a map of the cork distribution in the filament channel. Averaging the velocity vectors in the southern hemisphere in each latitude in steps of 3.5 arcsec, we defined a profile of the differential rotation. Results: Supergranules are clearly identified in the filament channel. Diverging flows inside the supergranules are similar in and out of the filament channel. Converging flows corresponding to the accumulation of corks are identified well around the Hα filament feet and at the edges of the EUV filament channel. At these convergence points, the <span class="hlt">horizontal</span> photospheric velocity may reach 1 km s-1, but with a mean velocity of 0.35 km s-1. In some locations, <span class="hlt">horizontal</span> flows crossing the channel are detected, indicating eventually large scale vorticity. Conclusions: The coupling between convection and magnetic field in the photosphere is relatively strong. The filament experienced the convection motions through its anchorage points with the photosphere, which are</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.C14B..08B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.C14B..08B"><span>Aquarius for the <span class="hlt">polar</span> regions: a new gridded product and its analysis over the cryosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brucker, L.; Dinnat, E.; Koenig, L.; Hakkinen, S. M.; Picard, G.; Vernières, G.; Borovikov, A.; Kovach, R.; Champollion, N.</p> <p>2013-12-01</p> <p>Microwave radiometers used to monitor the Earth's <span class="hlt">polar</span> regions typically operate in the frequency range 6-150 GHz. Recent radiometers, like those onboard SMOS and Aquarius/SAC-D spacecrafts, provide measurements at a lower frequency (~1.4 GHz, L-band), bringing new capabilities to monitor the state of the ice sheets, sea ice cover, and <span class="hlt">polar</span> oceans. We present a gridded weekly product of Aquarius measured <span class="hlt">brightness</span> temperature (TB) and backscatter, and of retrieved Sea Surface Salinity (SSS), for the northern and southern high latitudes. This product, specifically designed for the <span class="hlt">polar</span> regions, is distributed on the Equal-Area Scalable Earth Grid (EASE2.0) at 36-km resolution. This data set aims to increase the use of Aquarius measurements for cryospheric applications, and to improve our understanding of L-band measurements of ice sheet and sea ice. We describe it with a focus on the Greenland and Antarctic ice sheets. We also highlight the influence of the azimuth angle (~1 K for a 1.5o angle variation), and the variation within a grid cell (up to 1.5 K in locations where measurements are made 25+ times per one-week orbit cycle). This knowledge is of interest for geophysical property retrievals, and satellite intercalibration. In addition, we present an analysis of Aquarius measurements over the Antarctic Plateau, a potential target for intercalibration of spaceborne L-band radiometers. At Dome C, the mean annual TB is 181.2×0.7 K and 209.4×0.3 K for beam 3 at <span class="hlt">horizontal</span> and vertical <span class="hlt">polarizations</span>, respectively. While the annual standard deviation appears small, it is higher than the sensor accuracy of 0.2 K, especially at <span class="hlt">horizontal</span> <span class="hlt">polarization</span>. A careful analysis of the TB variations reveals an interesting correlation with the presence/absence of surface hoar (large grains) identified with autonomous daily infrared photographs of the snow surface. An additional correlation was found with the grain index retrieved from a combination of high microwave</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004Natur.428..627B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004Natur.428..627B"><span>Perennial water ice identified in the south <span class="hlt">polar</span> cap of Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bibring, Jean-Pierre; Langevin, Yves; Poulet, François; Gendrin, Aline; Gondet, Brigitte; Berthé, Michel; Soufflot, Alain; Drossart, Pierre; Combes, Michel; Bellucci, Giancarlo; Moroz, Vassili; Mangold, Nicolas; Schmitt, Bernard; OMEGA Team; Erard, S.; Forni, O.; Manaud, N.; Poulleau, G.; Encrenaz, T.; Fouchet, T.; Melchiorri, R.; Altieri, F.; Formisano, V.; Bonello, G.; Fonti, S.; Capaccioni, F.; Cerroni, P.; Coradini, A.; Kottsov, V.; Ignatiev, N.; Titov, D.; Zasova, L.; Pinet, P.; Sotin, C.; Hauber, E.; Hoffman, H.; Jaumann, R.; Keller, U.; Arvidson, R.; Mustard, J.; Duxbury, T.; Forget, F.</p> <p>2004-04-01</p> <p>The inventory of water and carbon dioxide reservoirs on Mars are important clues for understanding the geological, climatic and potentially exobiological evolution of the planet. From the early mapping observation of the permanent ice caps on the martian poles, the northern cap was believed to be mainly composed of water ice, whereas the southern cap was thought to be constituted of carbon dioxide ice. However, recent missions (NASA missions Mars Global Surveyor and Odyssey) have revealed surface structures, altimetry profiles, underlying buried hydrogen, and temperatures of the south <span class="hlt">polar</span> regions that are thermodynamically consistent with a mixture of surface water ice and carbon dioxide. Here we present the first direct identification and mapping of both carbon dioxide and water ice in the martian high southern latitudes, at a resolution of 2km, during the local summer, when the extent of the <span class="hlt">polar</span> ice is at its minimum. We observe that this south <span class="hlt">polar</span> cap contains perennial water ice in extended areas: as a small admixture to carbon dioxide in the <span class="hlt">bright</span> regions; associated with dust, without carbon dioxide, at the edges of this <span class="hlt">bright</span> cap; and, unexpectedly, in large areas tens of kilometres away from the <span class="hlt">bright</span> cap.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25969112','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25969112"><span>Different <span class="hlt">polarization</span> dynamic states in a vector Yb-doped fiber laser.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Xingliang; Zhang, Shumin; Han, Huiyun; Han, Mengmeng; Zhang, Huaxing; Zhao, Luming; Wen, Fang; Yang, Zhenjun</p> <p>2015-04-20</p> <p>Different <span class="hlt">polarization</span> dynamic states in an unidirectional, vector, Yb-doped fiber ring laser have been observed. A rich variety of dynamic states, including group velocity locked <span class="hlt">polarization</span> domains and their splitting into regularly distributed multiple domains, <span class="hlt">polarization</span> locked square pulses and their harmonic mode locking counterparts, and dissipative soliton resonances have all been observed with different operating parameters. We have also shown experimentally details of the conditions under which <span class="hlt">polarization</span>-domain-wall dark pulses and <span class="hlt">bright</span> square pulses form.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5853133','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5853133"><span>Investigating Mercury’s South <span class="hlt">Polar</span> Deposits: Arecibo Radar Observations and High-resolution Determination of Illumination Conditions</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chabot, Nancy L.; Shread, Evangela E.; Harmon, John K.</p> <p>2018-01-01</p> <p>There is strong evidence that Mercury’s <span class="hlt">polar</span> deposits are water ice hosted in permanently shadowed regions. In this study, we present new Arecibo radar observations of Mercury’s south pole, which reveal numerous radar-<span class="hlt">bright</span> deposits and substantially increase the radar imaging coverage. We also use images from MESSENGER’s full mission to determine the illumination conditions of Mercury’s south <span class="hlt">polar</span> region at the same spatial resolution as the north <span class="hlt">polar</span> region, enabling comparisons between the two poles. The area of radar-<span class="hlt">bright</span> deposits in Mercury’s south is roughly double that found in the north, consistent with the larger permanently shadowed area in the older, cratered terrain at the south relative to the younger smooth plains at the north. Radar-<span class="hlt">bright</span> features are strongly associated with regions of permanent shadow at both poles, consistent with water ice being the dominant component of the deposits. However, both of Mercury’s <span class="hlt">polar</span> regions show that roughly 50% of permanently shadowed regions lack radar-<span class="hlt">bright</span> deposits, despite some of these locations having thermal environments that are conducive to the presence of water ice. The observed uneven distribution of water ice among Mercury’s <span class="hlt">polar</span> cold traps may suggest that the source of Mercury’s water ice was not a steady, regular process but rather that the source was an episodic event, such as a recent, large impact on the innermost planet. PMID:29552436</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AIPC.1363..145I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AIPC.1363..145I"><span>Interferometric weak measurement of photon <span class="hlt">polarization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iinuma, Masataka; Suzuki, Yutaro; Taguchi, Gen; Kadoya, Yutaka; Hofmann, Holger F.</p> <p>2011-10-01</p> <p>We realize a minimum back-action quantum non-demolition measurement of variable strength on photon <span class="hlt">polarization</span> in the diagonal(PM) basis by two-mode path interference. This method uses the phase difference between the positive (P) and negative (M) superpositions in the interference between the <span class="hlt">horizontal</span> (H) and vertical (V) <span class="hlt">polarized</span> paths in the input beam. Although the interference can not occur when the H and V <span class="hlt">polarizations</span> are distinguishable, a well-controlled amount of interference is induced by erasing the H and V information using a coherent rotation of <span class="hlt">polarization</span> toward a common diagonal <span class="hlt">polarization</span>. This method is particularly suitable for the realization of weak measurements, where the control of the back-action is essential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFMSH13B2477B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFMSH13B2477B"><span><span class="hlt">Polarization</span> Observations of the Total Solar Eclipse of August 21, 2017</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Burkepile, J.; Boll, A.; Casini, R.; de Toma, G.; Elmore, D. F.; Gibson, K. L.; Judge, P. G.; Mitchell, A. M.; Penn, M.; Sewell, S. D.; Tomczyk, S.; Yanamandra-Fisher, P. A.</p> <p>2017-12-01</p> <p>A total solar eclipse offers ideal sky conditions for viewing the solar corona. Light from the corona is composed of three components: the E-corona, made up of spectral emission lines produced by ionized elements in the corona; the K-corona, produced by photospheric light that is Thomson scattered by coronal electrons; and the F-corona, produced by sunlight scattered from dust particles in the near Sun environment and in interplanetary space. <span class="hlt">Polarized</span> white light observations of the corona provide a way of isolating the K-corona to determine its structure, <span class="hlt">brightness</span>, and density. This work focuses on broadband white light <span class="hlt">polarization</span> observations of the corona during the upcoming solar eclipse from three different instruments. We compare coronal <span class="hlt">polarization</span> <span class="hlt">brightness</span> observations of the August 21, 2017 total solar eclipse from the NCAR/High Altitude Observatory (HAO) Rosetta Stone experiment using the 4-D Technology <span class="hlt">Polar</span>Cam camera with the two Citizen PACA_CATE17Pol telescopes that will acquire linear <span class="hlt">polarization</span> observations of the eclipse and the NCAR/HAO K-Cor white light coronagraph observations from the Mauna Loa Solar Observatory in Hawaii. This comparison includes a discussion of the cross-calibration of the different instruments and reports the results of the coronal <span class="hlt">polarization</span> <span class="hlt">brightness</span> and electron density of the corona. These observations will be compared with results from previous coronal measurements taken at different phases of the solar cycle. In addition, we report on the performance of the three different polarimeters. The 4-D <span class="hlt">Polar</span>Cam uses a linear <span class="hlt">polarizer</span> array, PACA_CATE17Pol uses a nematic liquid crystal retarder in a single beam configuration and K-Cor uses a pair of ferroelectric liquid crystal retarders in a dual-beam configuration. The use of the 4-D <span class="hlt">Polar</span>Cam camera in the Rosetta Stone experiment is to demonstrate the technology for acquiring high cadence <span class="hlt">polarization</span> measurements. The Rosetta Stone experiment is funded through</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810017363','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810017363"><span>Observations of <span class="hlt">polar</span> aurora on Jupiter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lane, A. L.; Clarke, J. T.; Moos, H. W.; Atreya, S. K.</p> <p>1981-01-01</p> <p>North-south spatial maps of Jupiter were obtained with the SWP camera in IUE observations of 10 December 1978, 19 May 1979, and 7 June 1979. <span class="hlt">Bright</span> auroral emissions were detected from the north and south <span class="hlt">polar</span> regions at H Ly alpha (1216 A) and in the H2 Lyman bands (1250-1608 A) on 19 May 1979; yet no enhanced <span class="hlt">polar</span> emission was detected on the other days. The relationship between the IUE observing geometry and the geometry of the Jovian magnetosphere is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JOpt...20c5101R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JOpt...20c5101R"><span>3D printed <span class="hlt">polarizing</span> grids for IR-THz synchrotron radiation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ryu, Meguya; Linklater, Denver; Hart, William; Balčytis, Armandas; Skliutas, Edvinas; Malinauskas, Mangirdas; Appadoo, Dominique; Tan, Yaw-Ren Eugene; Ivanova, Elena P.; Morikawa, Junko; Juodkazis, Saulius</p> <p>2018-03-01</p> <p>Grid polarisers 3D-printed out of commercial acrilic resin were tested for the polariser function and showed spectral regions where the dichroic ratio {D}R> 1 and < 1 implying importance of molecular and/or stress induced anisotropy. Metal-coated 3D-printed THz optical elements can find a range of applications in intensity and <span class="hlt">polarization</span> control of IR-THz beams. The used 3D printing method allows for fabrication of an arbitrary high aspect ratio grid polarisers. <span class="hlt">Polarization</span> analysis of synchrotron THz radiation was carried out with a standard stretched polyethylene polariser and revealed that the linearly <span class="hlt">polarized</span> (<span class="hlt">horizontal</span>) component contributes up to 22% ± 5% to the circular <span class="hlt">polarized</span> synchrotron emission extracted by a gold-coated mirror with a <span class="hlt">horizontal</span> slit inserted near the bending magnet edge. Comparison with theoretical predictions shows a qualitative match with dominance of the edge radiation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22092155-observations-magnetic-field-modeling-solar-polar-crown-prominence','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22092155-observations-magnetic-field-modeling-solar-polar-crown-prominence"><span>OBSERVATIONS AND MAGNETIC FIELD MODELING OF A SOLAR <span class="hlt">POLAR</span> CROWN PROMINENCE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Su Yingna; Van Ballegooijen, Adriaan, E-mail: ynsu@head.cfa.harvard.edu</p> <p>2012-10-01</p> <p>We present observations and magnetic field modeling of the large <span class="hlt">polar</span> crown prominence that erupted on 2010 December 6. Combination of Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA) and STEREO{sub B}ehind/EUVI allows us to see the fine structures of this prominence both at the limb and on the disk. We focus on the structures and dynamics of this prominence before the eruption. This prominence contains two parts: an active region part containing mainly <span class="hlt">horizontal</span> threads and a quiet-Sun part containing mainly vertical threads. On the northern side of the prominence channel, both AIA and EUVI observe <span class="hlt">bright</span> features which appearmore » to be the lower legs of loops that go above then join in the filament. Filament materials are observed to frequently eject <span class="hlt">horizontally</span> from the active region part to the quiet-Sun part. This ejection results in the formation of a dense-column structure (concentration of dark vertical threads) near the border between the active region and the quiet Sun. Using the flux rope insertion method, we create nonlinear force-free field models based on SDO/Helioseismic and Magnetic Imager line-of-sight magnetograms. A key feature of these models is that the flux rope has connections with the surroundings photosphere, so its axial flux varies along the filament path. The height and location of the dips of field lines in our models roughly replicate those of the observed prominence. Comparison between model and observations suggests that the <span class="hlt">bright</span> features on the northern side of the channel are the lower legs of the field lines that turn into the flux rope. We suggest that plasma may be injected into the prominence along these field lines. Although the models fit the observations quiet well, there are also some interesting differences. For example, the models do not reproduce the observed vertical threads and cannot explain the formation of the dense-column structure.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170003070&hterms=cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcycles','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170003070&hterms=cycles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcycles"><span>Unusual <span class="hlt">Polar</span> Conditions in Solar Cycle 24 and Their Implications for Cycle 25</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gopalswamy, Nat; Yashiro, Seiji; Akiyama, Sachiko</p> <p>2016-01-01</p> <p>We report on the prolonged solar-maximum conditions until late 2015 at the north-<span class="hlt">polar</span> region of the Sun indicated by the occurrence of high-latitude prominence eruptions (PEs) and microwave <span class="hlt">brightness</span> temperature close to the quiet-Sun level. These two aspects of solar activity indicate that the <span class="hlt">polarity</span> reversal was completed by mid-2014 in the south and late 2015 in the north. The microwave <span class="hlt">brightness</span> in the south-<span class="hlt">polar</span> region has increased to a level exceeding the level of the Cycle 23/24 minimum, but just started to increase in the north. The northsouth asymmetry in the <span class="hlt">polarity</span> reversal has switched from that in Cycle 23. These observations lead us to the hypothesis that the onset of Cycle 25 in the northern hemisphere is likely to be delayed with respect to that in the southern hemisphere. We find that the unusual condition in the north is a direct consequence of the arrival of poleward surges of opposite <span class="hlt">polarity</span> from the active region belt. We also find that multiple rush-to-the-pole episodes were indicated by the PE locations that lined up at the boundary between opposite-<span class="hlt">polarity</span> surges. The high-latitude PEs occurred in the boundary between the incumbent <span class="hlt">polar</span> flux and the insurgent flux of opposite <span class="hlt">polarity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RaSc...52.1544S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RaSc...52.1544S"><span>High-Isolation Low Cross-<span class="hlt">Polarization</span> Phased-Array Antenna for MPAR Application</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saeidi-Manesh, Hadi; Karimkashi, Shaya; Zhang, Guifu; Doviak, Richard J.</p> <p>2017-12-01</p> <p>The design and analysis of 12 × 12-element planar array of a dual-<span class="hlt">polarized</span> aperture-coupled microstrip patch antenna operating in the frequency band of 2.7 GHz to 3.0 GHz for multifunction applications are presented. High-isolation between <span class="hlt">horizontal</span> and vertical <span class="hlt">polarization</span> ports and low cross-<span class="hlt">polarization</span> are achieved through an aperture-coupled feed. The reflection coefficient and the isolation of <span class="hlt">horizontal</span> and vertical ports at different scan angles are examined. The array antenna is fabricated and its radiation patterns are measured in the far-field and near-field chambers. The embedded element pattern of designed element is measured in the near-field chamber and is used for calculating the array scanning radiation pattern.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MS%26E..274a2018Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MS%26E..274a2018Z"><span>Study on Low Illumination Simultaneous <span class="hlt">Polarization</span> Image Registration Based on Improved SURF Algorithm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Wanjun; Yang, Xu</p> <p>2017-12-01</p> <p>Registration of simultaneous <span class="hlt">polarization</span> images is the premise of subsequent image fusion operations. However, in the process of shooting all-weather, the <span class="hlt">polarized</span> camera exposure time need to be kept unchanged, sometimes <span class="hlt">polarization</span> images under low illumination conditions due to too dark result in SURF algorithm can not extract feature points, thus unable to complete the registration, therefore this paper proposes an improved SURF algorithm. Firstly, the luminance operator is used to improve overall <span class="hlt">brightness</span> of low illumination image, and then create integral image, using Hession matrix to extract the points of interest to get the main direction of characteristic points, calculate Haar wavelet response in X and Y directions to get the SURF descriptor information, then use the RANSAC function to make precise matching, the function can eliminate wrong matching points and improve accuracy rate. And finally resume the <span class="hlt">brightness</span> of the <span class="hlt">polarized</span> image after registration, the effect of the <span class="hlt">polarized</span> image is not affected. Results show that the improved SURF algorithm can be applied well under low illumination conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840019187','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840019187"><span>Crop moisture estimation over the southern Great Plains with dual <span class="hlt">polarization</span> 1.66 centimeter passive microwave data from Nimbus 7</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mcfarland, M. J.; Harder, P. H., II; Wilke, G. D.; Huebner, G. L., Jr.</p> <p>1984-01-01</p> <p>Moisture content of snow-free, unfrozen soil is inferred using passive microwave <span class="hlt">brightness</span> temperatures from the scanning multichannel microwave radiometer (SMMR) on Nimbus-7. Investigation is restricted to the two <span class="hlt">polarizations</span> of the 1.66 cm wavelength sensor. Passive microwave estimates of soil moisture are of two basic categories; those based upon soil emissivity and those based upon the <span class="hlt">polarization</span> of soil emission. The two methods are compared and contrasted through the investigation of 54 potential functions of <span class="hlt">polarized</span> <span class="hlt">brightness</span> temperatures and, in some cases, ground-based temperature measurements. Of these indices, three are selected for the estimated emissivity, the difference between <span class="hlt">polarized</span> <span class="hlt">brightness</span> temperatures, and the normalized <span class="hlt">polarization</span> difference. Each of these indices is about equally effective for monitoring soil moisture. Using an antecedent precipitation index (API) as ground control data, temporal and spatial analyses show that emissivity data consistently give slightly better soil moisture estimates than depolarization data. The difference, however, is not statistically significant. It is concluded that <span class="hlt">polarization</span> data alone can provide estimates of soil moisture in areas where the emissivity cannot be inferred due to nonavailability of surface temperature data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JVSJ...55...50T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JVSJ...55...50T"><span>Advanced Laser Technologies for High-<span class="hlt">brightness</span> Photocathode Electron Gun</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tomizawa, Hiromitsu</p> <p></p> <p>A laser-excited photocathode RF gun is one of the most reliable high-<span class="hlt">brightness</span> electron beam sources for XFELs. Several 3D laser shaping methods have been developed as ideal photocathode illumination sources at SPring-8 since 2001. To suppress the emittance growth caused by nonlinear space-charge forces, the 3D cylindrical UV-pulse was optimized spatially as a flattop and temporally as squarely stacked chirped pulses. This shaping system is a serial combination of a deformable mirror that adaptively shapes the spatial profile with a genetic algorithm and a UV-pulse stacker that consists of four birefringent α-BBO crystal rods for temporal shaping. Using this 3D-shaped pulse, a normalized emittance of 1.4 π mm mrad was obtained in 2006. Utilizing laser's Z-<span class="hlt">polarization</span>, Schottky-effect-gated photocathode gun was proposed in 2006. The cathode work functions are reduced by a laser-induced Schottky effect. As a result of focusing a radially <span class="hlt">polarized</span> laser pulse with a hollow lens in vacuum, the Z-field (Z-<span class="hlt">polarization</span>) is generated at the cathode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018Icar..308..197S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018Icar..308..197S"><span>Katabatic jumps in the Martian northern <span class="hlt">polar</span> regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spiga, Aymeric; Smith, Isaac</p> <p>2018-07-01</p> <p>Martian <span class="hlt">polar</span> regions host active regional wind circulations, such as the downslope katabatic winds which develop owing to near-surface radiative cooling and sloped topography. Many observations (stratigraphy from radar profiling, frost streaks, spectral analysis of ices) concur to show that aeolian processes play a key role in glacial processes in Martian <span class="hlt">polar</span> regions. A spectacular manifestation of this resides in elongated clouds that forms within the <span class="hlt">polar</span> spiral troughs, a series of geological depressions in Mars' <span class="hlt">polar</span> caps. Here we report mesoscale atmospheric modeling in Martian <span class="hlt">polar</span> regions making use of five nested domains operating a model downscaling from <span class="hlt">horizontal</span> resolutions of twenty kilometers to 200 m in a typical <span class="hlt">polar</span> trough. We show that strong katabatic jumps form at the bottom of <span class="hlt">polar</span> troughs with an <span class="hlt">horizontal</span> morphology and location similar to trough clouds, large vertical velocity (up to +3 m/s) and temperature perturbations (up to 20 K) propitious to cloud formation. This strongly suggests that trough clouds on Mars are caused by katabatic jumps forming within <span class="hlt">polar</span> troughs. This phenomena is analogous to the terrestrial Loewe phenomena over Antarctica's slopes and coastlines, resulting in a distinctive "wall of snow" during katabatic events. Our mesoscale modeling results thereby suggest that trough clouds might be present manifestations of the ice migration processes that yielded the internal cap structure discovered by radar observations, as part of a "cyclic step" process. This has important implications for the stability and possible migration over geological timescales of water ice surface reservoirs-and, overall, for the evolution of Mars' <span class="hlt">polar</span> caps over geological timescales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA04151&hterms=polygons&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpolygons','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA04151&hterms=polygons&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpolygons"><span><span class="hlt">Polar</span> Polygons</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2005-01-01</p> <p><p/> 18 August 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark-outlined polygons on a frost-covered surface in the south <span class="hlt">polar</span> region of Mars. In summer, this surface would not be <span class="hlt">bright</span> and the polygons would not have dark outlines--these are a product of the presence of seasonal frost. <p/> <i>Location near</i>: 77.2oS, 204.8oW <i>Image width</i>: width: 3 km (1.9 mi) <i>Illumination from</i>: upper left <i>Season</i>: Southern Spring</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA02301&hterms=snow+leopard&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsnow%2Bleopard','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA02301&hterms=snow+leopard&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsnow%2Bleopard"><span>Defrosting <span class="hlt">Polar</span> Dunes--'The Snow Leopard'</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1999-01-01</p> <p><p/>The patterns created by dark spots on defrosting south <span class="hlt">polar</span> dunes are often strange and beautiful. This picture, which the Mars Orbiter Camera team has dubbed, 'the snow leopard,' shows a dune field located at 61.5oS, 18.9oW, as it appeared on July 1, 1999. The spots are areas where dark sand has been exposed from beneath <span class="hlt">bright</span> frost as the south <span class="hlt">polar</span> winter cap begins to retreat. Many of the spots have a diffuse, <span class="hlt">bright</span> ring around them this is thought to be fresh frost that was re-precipitated after being removed from the dark spot. The spots seen on defrosting <span class="hlt">polar</span> dunes are a new phenomenon that was not observed by previous spacecraft missions to Mars. Thus, there is much about these features that remains unknown. For example, no one yet knows why the dunes become defrosted by forming small spots that grow and grow over time. No one knows for sure if the <span class="hlt">bright</span> rings around the dark spots are actually composed of re-precipitated frost. And no one knows for sure why some dune show spots that appear to be 'lined-up' (as they do in the picture shown here). <p/>This Mars Global Surveyor Mars Orbiter Camera image is illuminated from the upper left. North is toward the upper right. The scale bar indicates a distance of 200 meters (656 feet). <p/>Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JPhCS.992a2056M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JPhCS.992a2056M"><span><span class="hlt">Polarization</span> holographic gratings in PAZO azopolymer recorded with different recording-beams <span class="hlt">polarizations</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mateev, G.; Nedelchev, L.; Ivanov, D.; Tomova, R.; Petrova, P.; Strijkova, V.; Berberova, N.; Nazarova, D.</p> <p>2018-03-01</p> <p><span class="hlt">Polarization</span> holographic gratings (PHG) were recorded using a laser emitting a wavelength of 491 nm in thin films of the (poly[1-[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfonamido]-1,2-ethanediyl, sodium salt]) azopolymer, shortly denoted as PAZO. Thin azopolymer films with various thicknesses were spin-coated on plastic and glass substrates. Four different <span class="hlt">polarization</span> states of the recording beams were used, and the results compared: a) two vertical linear <span class="hlt">polarizations</span>, b) <span class="hlt">horizontal</span> and vertical linear <span class="hlt">polarizations</span>, c) linear <span class="hlt">polarizations</span> at +45° and –45° relative to the recording plane, and d) two orthogonal circular <span class="hlt">polarizations</span> – left- and right-handed (LCP and RCP). The diffraction efficiency in the +1 diffraction order was monitored in real time by a probing laser beam at the wavelength of 635 nm. The results indicate that the highest diffraction efficiency is achieved when recording with orthogonal <span class="hlt">polarizations</span> – linear at ±45° or left and right circular. This is explained by the ability of the azopolymer material to record the variations in the <span class="hlt">polarization</span> state of light better than the variations in its intensity. The holographic gratings obtained can be used to enhance the light-extraction efficiency of an OLED device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27586611','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27586611"><span>Rogue-pair and dark-<span class="hlt">bright</span>-rogue waves of the coupled nonlinear Schrödinger equations from inhomogeneous femtosecond optical fibers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yomba, Emmanuel; Zakeri, Gholam-Ali</p> <p>2016-08-01</p> <p>The coupled inhomogeneous Schrödinger equations with a wide range of applications describing a field of pluses with the right and the left <span class="hlt">polarizations</span> that take into account cross-phase modulations, stimulated Ramani scattering, and absorption effects are investigated. A combination of several different approaches is used in a novel way to obtain the explicit expressions for the rogue-pair and dark-<span class="hlt">bright</span>-rogue waves. We study the dynamics of these structurally stable rogues and analyze the effects of a parameter that controls the region of stability that intrinsically connects the cross-phase modulation and other Kerr nonlinearity factors. The effects of the right and left <span class="hlt">polarizations</span> on the shape of the rogue-pair and other solitary rogue waves are graphically analyzed. These rogue-pair waves are studied on periodic and non-periodic settings. We observe that rogue-pair wave from the right and left <span class="hlt">polarizations</span> has a similar structure while the dark-<span class="hlt">bright</span>-rogue waves have quite different intensity profiles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005ASPC..337..265M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005ASPC..337..265M"><span>The <span class="hlt">Polarization</span> of Achernar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McDavid, D.</p> <p>2005-11-01</p> <p>Recent near-infrared measurements of the angular diameter of Achernar (the <span class="hlt">bright</span> Be star alpha Eridani) with the ESO VLT interferometer have been interpreted as the detection of an extremely oblate photosphere, with a ratio of equatorial to <span class="hlt">polar</span> radius of at least 1.56 ± 0.05 and a minor axis orientation of 39° ± 1° (from North to East). The optical linear <span class="hlt">polarization</span> of this star during an emission phase in 1995 September was 0.12 ± 0.02% at position angle 37° ± 8° (in equatorial coordinates), which is the direction of the projection of the rotation axis on the plane of the sky according to the theory of <span class="hlt">polarization</span> by electron scattering in an equatorially flattened circumstellar disk. These two independent determinations of the orientation of the rotation axis are therefore in agreement. The observational history of correlations between Hα emission and <span class="hlt">polarization</span> as found in the literature is that of a typical Be star, with the exception of an interesting question raised by the contrast between Schröder's measurement of a small <span class="hlt">polarization</span> perpendicular to the projected rotation axis in 1969--70 and Tinbergen's measurement of zero <span class="hlt">polarization</span> in 1974.5, both at times when emission was reportedly absent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...848...47N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...848...47N"><span>Constraining <span class="hlt">Polarized</span> Foregrounds for EoR Experiments. II. <span class="hlt">Polarization</span> Leakage Simulations in the Avoidance Scheme</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nunhokee, C. D.; Bernardi, G.; Kohn, S. A.; Aguirre, J. E.; Thyagarajan, N.; Dillon, J. S.; Foster, G.; Grobler, T. L.; Martinot, J. Z. E.; Parsons, A. R.</p> <p>2017-10-01</p> <p>A critical challenge in the observation of the redshifted 21 cm line is its separation from <span class="hlt">bright</span> Galactic and extragalactic foregrounds. In particular, the instrumental leakage of <span class="hlt">polarized</span> foregrounds, which undergo significant Faraday rotation as they propagate through the interstellar medium, may harmfully contaminate the 21 cm power spectrum. We develop a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra measured with redundant arrays, extending the delay-spectrum approach presented in Parsons et al. We construct <span class="hlt">polarized</span> sky models and propagate them through the instrument model to simulate realistic full-sky observations with the Precision Array to Probe the Epoch of Reionization. We find that the leakage due to a population of <span class="hlt">polarized</span> point sources is expected to be higher than diffuse Galactic <span class="hlt">polarization</span> at any k mode for a 30 m reference baseline. For the same reference baseline, a foreground-free window at k > 0.3 h Mpc-1 can be defined in terms of leakage from diffuse Galactic <span class="hlt">polarization</span> even under the most pessimistic assumptions. If measurements of <span class="hlt">polarized</span> foreground power spectra or a model of <span class="hlt">polarized</span> foregrounds are given, our method is able to predict the <span class="hlt">polarization</span> leakage in actual 21 cm observations, potentially enabling its statistical subtraction from the measured 21 cm power spectrum.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996JGR...101.5075L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996JGR...101.5075L"><span>Relationship between large <span class="hlt">horizontal</span> electric fields and auroral arc elements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lanchester, B. S.; Kailá, K.; McCrea, I. W.</p> <p>1996-03-01</p> <p>High time resolution optical measurements in the magnetic zenith are compared with European Incoherent Scatter (EISCAT) field-aligned measurements of electron density at 0.2-s resolution and with <span class="hlt">horizontal</span> electric field measurements made at 278 km with resolution of 9 s. In one event, 20 min after a spectacular auroral breakup, a system of narrow and active arc elements moved southward into the magnetic zenith, where it remained for several minutes. During a 30-s interval of activity in a narrow arc element very close to the radar beam, the electric field vectors at 3-s resolution were found to be extremely large (up to 400 mVm-1) and to point toward the <span class="hlt">bright</span> optical features in the arc, which moved along its length. It is proposed that the large electric fields are short-lived and are directly associated with the particle precipitation that causes the <span class="hlt">bright</span> features in auroral arc elements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=252606','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=252606"><span>Passive Polarimetric Microwave Signatures Observed Over Antarctica</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>WindSat satellite-based fully polarimetric passive microwave observations, expressed in the form of the Stokes vector, were analyzed over the Antarctic ice sheet. The vertically and <span class="hlt">horizontally</span> <span class="hlt">polarized</span> <span class="hlt">brightness</span> temperatures (first two Stokes components) from WindSat are shown to be consistent w...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-s30-86-021.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-s30-86-021.html"><span><span class="hlt">Polarized</span> Light Experiment, Presa Don Martin, Mexico</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1989-05-08</p> <p>This is a single scene from a pair (frames 021 & 024) to study the effects of <span class="hlt">polarized</span> light in Earth Observations. One scene was exposed with vertically <span class="hlt">polarized</span> light, the other, <span class="hlt">horizontally</span>. The subject in this study, is a lake behind Presa (dam) Don Martin (27.5N, 100.5W) on thge edge of the Rio Grande Plain near it's boundry with the Sierra Madre Oriental in Coahuila, Mexico.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19830039005&hterms=soybeans+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsoybeans%2Bfield','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19830039005&hterms=soybeans+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsoybeans%2Bfield"><span>A model for microwave emission from vegetation-covered fields</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mo, T.; Choudhury, B. J.; Schmugge, T. J.; Wang, J. R.; Jackson, T. J.</p> <p>1982-01-01</p> <p>The measured <span class="hlt">brightness</span> temperatures over vegetation-covered fields are simulated by a radiative transfer model which treats the vegetation as a uniform canopy with a constant temperature, over a moist soil which emits <span class="hlt">polarized</span> microwave radiation. The analytic formula for the microwave emission has four parameters: roughness height, <span class="hlt">polarization</span> mixing factor, effective canopy optical thickness, and single scattering albedo. A good representation has been obtained with the model for both the <span class="hlt">horizontally</span> and vertically <span class="hlt">polarized</span> <span class="hlt">brightness</span> temperatures at 1.4 and 5 GHz frequencies, over fields covered with grass, soybean and corn. A directly proportional relation is found between effective canopy optical thickness and the amount of water present in the vegetation canopy. The effective canopy single scattering albedo depends on vegetation type.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17363631','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17363631"><span>Early optical <span class="hlt">polarization</span> of a gamma-ray burst afterglow.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mundell, Carole G; Steele, Iain A; Smith, Robert J; Kobayashi, Shiho; Melandri, Andrea; Guidorzi, Cristiano; Gomboc, Andreja; Mottram, Chris J; Clarke, David; Monfardini, Alessandro; Carter, David; Bersier, David</p> <p>2007-03-30</p> <p>We report the optical <span class="hlt">polarization</span> of a gamma-ray burst (GRB) afterglow, obtained 203 seconds after the initial burst of gamma-rays from GRB 060418, using a ring polarimeter on the robotic Liverpool Telescope. Our robust (2sigma) upper limit on the percentage of <span class="hlt">polarization</span>, less than 8%, coincides with the fireball deceleration time at the onset of the afterglow. The combination of the rate of decay of the optical <span class="hlt">brightness</span> and the low <span class="hlt">polarization</span> at this critical time constrains standard models of GRB ejecta, ruling out the presence of a large-scale ordered magnetic field in the emitting region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AAS...198.2103C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AAS...198.2103C"><span><span class="hlt">Polarization</span> Observations with the Cosmic Background Imager</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cartwright, J. K.; Padin, S.; Pearson, T. J.; Readhead, A. C. S.; Shepherd, M. C.; Taylor, G. B.</p> <p>2001-05-01</p> <p>We describe <span class="hlt">polarization</span> observations of the CMBR with the Cosmic Background Imager, a 13 element interferometer which operates in the 26-36 GHz band from a site at 5000m in northern Chile. The array consists of 90-cm Cassegrain antennas mounted on a single, fully steerable platform; this platform can be rotated about the optical axis to facilitate <span class="hlt">polarization</span> observations. The CBI employs single mode circularly <span class="hlt">polarized</span> receivers, of which 12 are configured for LCP and one is configured for RCP. The 12 cross <span class="hlt">polarized</span> baselines sample multipoles from l 600 to l 3500. The instrumental <span class="hlt">polarization</span> of the CBI was calibrated with observations of 3C279, a <span class="hlt">bright</span> <span class="hlt">polarized</span> source which is unresolved by the CBI. Because the centimeter flux of 3C279 is variable, it was monitored twice per month for 8 months in 2000 with the VLA at 22 and 43 GHz. These observations also established the stability of the <span class="hlt">polarization</span> characteristics of the CBI. This work was made possible by NSF grant AST-9802989</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26125371','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26125371"><span><span class="hlt">Polarization</span> changes in light beams trespassing anisotropic turbulence.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Korotkova, Olga</p> <p>2015-07-01</p> <p>The <span class="hlt">polarization</span> properties of deterministic or random light with isotropic source correlations propagating in anisotropic turbulence along <span class="hlt">horizontal</span> paths are considered for the first time and predicted to change on the basis of the second-order coherence theory of beam-like fields and the extended Huygens-Fresnel integral. Our examples illustrate that the beams whose degree of <span class="hlt">polarization</span> is unaffected by free-space propagation or isotropic turbulence can either decrease or increase on traversing the anisotropic turbulence, depending on the <span class="hlt">polarization</span> state of the source.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8939852','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8939852"><span><span class="hlt">Bright</span> Spots, Structure, and Magmatism in Southern Tibet from INDEPTH Seismic Reflection Profiling</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brown; Zhao; Nelson; Hauck; Alsdorf; Ross; Cogan; Clark; Liu; Che</p> <p>1996-12-06</p> <p>INDEPTH seismic reflection profiling shows that the decollement beneath which Indian lithosphere underthrusts the Himalaya extends at least 225 kilometers north of the Himalayan deformation front to a depth of approximately 50 kilometers. Prominent reflections appear at depths of 15 to 18 kilometers near where the decollement reflector apparently terminates. These reflections extend north of the Zangbo suture to the Damxung graben of the Tibet Plateau. Some of these reflections have locally anomalous amplitudes (<span class="hlt">bright</span> spots) and coincident negative <span class="hlt">polarities</span> implying that they are produced by fluids in the crust. The presence of geothermal activity and high heat flow in the regions of these reflections and the tectonic setting suggest that the <span class="hlt">bright</span> spots mark granitic magmas derived by partial melting of the tectonically thickened crust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130001619','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130001619"><span>Characterization of the Morphometry of Impact Craters Hosting <span class="hlt">Polar</span> Deposits in Mercury's North <span class="hlt">Polar</span> Region</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Talpe Matthieu; Zuber, Maria T.; Yang, Di; Neumann, Gregory A.; Solomon, Sean C.; Mazarico, Erwan; Vilas, Faith</p> <p>2012-01-01</p> <p>Earth-based radar images of Mercury show radar-<span class="hlt">bright</span> material inside impact craters near the planet s poles. A previous study indicated that the <span class="hlt">polar</span>-deposit-hosting craters (PDCs) at Mercury s north pole are shallower than craters that lack such deposits. We use data acquired by the Mercury Laser Altimeter on the MESSENGER spacecraft during 11 months of orbital observations to revisit the depths of craters at high northern latitudes on Mercury. We measured the depth and diameter of 537 craters located poleward of 45 N, evaluated the slopes of the northern and southern walls of 30 PDCs, and assessed the floor roughness of 94 craters, including nine PDCs. We find that the PDCs appear to have a fresher crater morphology than the non-PDCs and that the radar-<span class="hlt">bright</span> material has no detectable influence on crater depths, wall slopes, or floor roughness. The statistical similarity of crater depth-diameter relations for the PDC and non-PDC populations places an upper limit on the thickness of the radar-<span class="hlt">bright</span> material (< 170 m for a crater 11 km in diameter) that can be refined by future detailed analysis. Results of the current study are consistent with the view that the radar-<span class="hlt">bright</span> material constitutes a relatively thin layer emplaced preferentially in comparatively young craters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140017105','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140017105"><span>Weekly Gridded Aquarius L-band Radiometer-Scatterometer Observations and Salinity Retrievals over the <span class="hlt">Polar</span> Regions - Part 2: Initial Product Analysis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brucker, L.; Dinnat, E. P.; Koenig, L. S.</p> <p>2014-01-01</p> <p>Following the development and availability of Aquarius weekly <span class="hlt">polar</span>-gridded products, this study presents the spatial and temporal radiometer and scatterometer observations at L band (frequency1.4 GHz) over the cryosphere including the Greenland and Antarctic ice sheets, sea ice in both hemispheres, and over sub-Arctic land for monitoring the soil freeze-thaw state. We provide multiple examples of scientific applications for the L-band data over the cryosphere. For example, we show that over the Greenland Ice Sheet, the unusual 2012 melt event lead to an L-band <span class="hlt">brightness</span> temperature (TB) sustained decrease of 5 K at <span class="hlt">horizontal</span> <span class="hlt">polarization</span>. Over the Antarctic ice sheet, normalized radar cross section (NRCS) observations recorded during ascending and descending orbits are significantly different, highlighting the anisotropy of the ice cover. Over sub-Arctic land, both passive and active observations show distinct values depending on the soil physical state (freeze-thaw). Aquarius sea surface salinity (SSS) retrievals in the <span class="hlt">polar</span> waters are also presented. SSS variations could serve as an indicator of fresh water input to the ocean from the cryosphere, however the presence of sea ice often contaminates the SSS retrievals, hindering the analysis. The weekly grided Aquarius L-band products used a redistributed by the US Snow and Ice Data Center at http:nsidc.orgdataaquariusindex.html, and show potential for cryospheric studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22679766-constraining-polarized-foregrounds-eor-experiments-ii-polarization-leakage-simulations-avoidance-scheme','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22679766-constraining-polarized-foregrounds-eor-experiments-ii-polarization-leakage-simulations-avoidance-scheme"><span>Constraining <span class="hlt">Polarized</span> Foregrounds for EoR Experiments. II. <span class="hlt">Polarization</span> Leakage Simulations in the Avoidance Scheme</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Nunhokee, C. D.; Bernardi, G.; Foster, G.</p> <p></p> <p>A critical challenge in the observation of the redshifted 21 cm line is its separation from <span class="hlt">bright</span> Galactic and extragalactic foregrounds. In particular, the instrumental leakage of <span class="hlt">polarized</span> foregrounds, which undergo significant Faraday rotation as they propagate through the interstellar medium, may harmfully contaminate the 21 cm power spectrum. We develop a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra measured with redundant arrays, extending the delay-spectrum approach presented in Parsons et al. We construct <span class="hlt">polarized</span> sky models and propagate them through the instrument model to simulate realistic full-sky observations with the Precision Arraymore » to Probe the Epoch of Reionization. We find that the leakage due to a population of <span class="hlt">polarized</span> point sources is expected to be higher than diffuse Galactic <span class="hlt">polarization</span> at any k mode for a 30 m reference baseline. For the same reference baseline, a foreground-free window at k > 0.3 h Mpc{sup −1} can be defined in terms of leakage from diffuse Galactic <span class="hlt">polarization</span> even under the most pessimistic assumptions. If measurements of <span class="hlt">polarized</span> foreground power spectra or a model of <span class="hlt">polarized</span> foregrounds are given, our method is able to predict the <span class="hlt">polarization</span> leakage in actual 21 cm observations, potentially enabling its statistical subtraction from the measured 21 cm power spectrum.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.C51C0996R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.C51C0996R"><span>Testing Snow Melt Algorithms in High Relief Topography Using Calibrated Enhanced-Resolution <span class="hlt">Brightness</span> Temperatures, Hunza River Basin, Pakistan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramage, J. M.; Brodzik, M. J.; Hardman, M.; Troy, T. J.</p> <p>2017-12-01</p> <p>Snow is a vital part of the terrestrial hydrological cycle, a crucial resource for people and ecosystems. In mountainous regions snow is extensive, variable, and challenging to document. Snow melt timing and duration are important factors affecting the transfer of snow mass to soil moisture and runoff. Passive microwave <span class="hlt">brightness</span> temperature (Tb) changes at 36 and 18 GHz are a sensitive way to detect snow melt onset due to their sensitivity to the abrupt change in emissivity. They are widely used on large icefields and high latitude watersheds. The coarse resolution ( 25 km) of historically available data has precluded effective use in high relief, heterogeneous regions, and gaps between swaths also create temporal data gaps at lower latitudes. New enhanced resolution data products generated from a scatterometer image reconstruction for radiometer (rSIR) technique are available at the original frequencies. We use these Calibrated Enhanced-resolution <span class="hlt">Brightness</span> (CETB) Temperatures Earth System Data Records (ESDR) to evaluate existing snow melt detection algorithms that have been used in other environments, including the cross <span class="hlt">polarized</span> gradient ratio (XPGR) and the diurnal amplitude variations (DAV) approaches. We use the 36/37 GHz (3.125 km resolution) and 18/19 GHz (6.25 km resolution) vertically and <span class="hlt">horizontally</span> <span class="hlt">polarized</span> datasets from the Special Sensor Microwave Imager (SSM/I) and Advanced Microwave Radiometer for EOS (AMSR-E) and evaluate them for use in this high relief environment. The new data are used to assess glacier and snow melt records in the Hunza River Basin [area 13,000 sq. km, located at 36N, 74E], a tributary to the Upper Indus Basin, Pakistan. We compare the melt timing results visually and quantitatively to the corresponding EASE-Grid 2.0 25-km dataset, SRTM topography, and surface temperatures from station and reanalysis data. The new dataset is coarser than the topography, but is able to differentiate signals of melt/refreeze timing for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27103935','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27103935"><span>Circadian Phase-Shifting Effects of <span class="hlt">Bright</span> Light, Exercise, and <span class="hlt">Bright</span> Light + Exercise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Youngstedt, Shawn D; Kline, Christopher E; Elliott, Jeffrey A; Zielinski, Mark R; Devlin, Tina M; Moore, Teresa A</p> <p>2016-02-26</p> <p>Limited research has compared the circadian phase-shifting effects of <span class="hlt">bright</span> light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night <span class="hlt">bright</span> light, late night exercise, and late evening <span class="hlt">bright</span> light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) <span class="hlt">bright</span> light alone (5,000 lux) from 2210-2340 h, (2) treadmill exercise alone from 2210-2340 h, or (3) <span class="hlt">bright</span> light (2210-2340 h) followed by exercise from 0410-0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of <span class="hlt">bright</span> light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following <span class="hlt">bright</span> light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night <span class="hlt">bright</span> light followed by early morning exercise can have an additive circadian phase-shifting effect.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26424464','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26424464"><span>Naturally together: pitch-height and <span class="hlt">brightness</span> as coupled factors for eliciting the SMARC effect in non-musicians.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pitteri, Marco; Marchetti, Mauro; Priftis, Konstantinos; Grassi, Massimo</p> <p>2017-01-01</p> <p>Pitch-height is often labeled spatially (i.e., low or high) as a function of the fundamental frequency of the tone. This correspondence is highlighted by the so-called Spatial-Musical Association of Response Codes (SMARC) effect. However, the literature suggests that the <span class="hlt">brightness</span> of the tone's timbre might contribute to this spatial association. We investigated the SMARC effect in a group of non-musicians by disentangling the role of pitch-height and the role of tone-<span class="hlt">brightness</span>. In three experimental conditions, participants were asked to judge whether the tone they were listening to was (or was not) modulated in amplitude (i.e., vibrato). Participants were required to make their response in both the <span class="hlt">horizontal</span> and the vertical axes. In a first condition, tones varied coherently in pitch (i.e., manipulation of the tone's F0) and <span class="hlt">brightness</span> (i.e., manipulation of the tone's spectral centroid); in a second condition, pitch-height varied whereas <span class="hlt">brightness</span> was fixed; in a third condition, pitch-height was fixed whereas <span class="hlt">brightness</span> varied. We found the SMARC effect only in the first condition and only in the vertical axis. In contrast, we did not observe the effect in any of the remaining conditions. The present results suggest that, in non-musicians, the SMARC effect is not due to the manipulation of the pitch-height alone, but arises because of a coherent change of pitch-height and <span class="hlt">brightness</span>; this effect emerges along the vertical axis only.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160013720&hterms=Physical&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DPhysical','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160013720&hterms=Physical&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DPhysical"><span>Physical Models of Layered <span class="hlt">Polar</span> Firn <span class="hlt">Brightness</span> Temperatures from 0.5 to 2 GHz</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tan, Shurun; Aksoy, Mustafa; Brogioni, Marco; Macelloni, Giovanni; Durand, Michael; Jezek, Kenneth C.; Wang, Tian-Lin; Tsang, Leung; Johnson, Joel T.; Drinkwater, Mark R.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20160013720'); toggleEditAbsImage('author_20160013720_show'); toggleEditAbsImage('author_20160013720_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20160013720_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20160013720_hide"></p> <p>2015-01-01</p> <p>We investigate physical effects influencing 0.5-2 GHz <span class="hlt">brightness</span> temperatures of layered <span class="hlt">polar</span> firn to support the Ultra Wide Band Software Defined Radiometer (UWBRAD) experiment to be conducted in Greenland and in Antarctica. We find that because ice particle grain sizes are very small compared to the 0.5-2 GHz wavelengths, volume scattering effects are small. Variations in firn density over cm- to m-length scales, however, cause significant effects. Both incoherent and coherent models are used to examine these effects. Incoherent models include a 'cloud model' that neglects any reflections internal to the ice sheet, and the DMRT-ML and MEMLS radiative transfer codes that are publicly available. The coherent model is based on the layered medium implementation of the fluctuation dissipation theorem for thermal microwave radiation from a medium having a nonuniform temperature. Density profiles are modeled using a stochastic approach, and model predictions are averaged over a large number of realizations to take into account an averaging over the radiometer footprint. Density profiles are described by combining a smooth average density profile with a spatially correlated random process to model density fluctuations. It is shown that coherent model results after ensemble averaging depend on the correlation lengths of the vertical density fluctuations. If the correlation length is moderate or long compared with the wavelength (approximately 0.6x longer or greater for Gaussian correlation function without regard for layer thinning due to compaction), coherent and incoherent model results are similar (within approximately 1 K). However, when the correlation length is short compared to the wavelength, coherent model results are significantly different from the incoherent model by several tens of kelvins. For a 10-cm correlation length, the differences are significant between 0.5 and 1.1 GHz, and less for 1.1-2 GHz. Model results are shown to be able to match the v</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000AAS...197.5502C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000AAS...197.5502C"><span><span class="hlt">Polarization</span> Observations with the Cosmic Background Imager</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cartwright, J. K.; Padin, S.; Pearson, T. J.; Readhead, A. C. S.; Shepherd, M. C.; Taylor, G. B.</p> <p>2000-12-01</p> <p>The linear <span class="hlt">polarization</span> of the Cosmic Microwave Background Radiation is a fundamental prediction of the standard model. We report a limit on the <span class="hlt">polarization</span> of the CMBR for l ~660. This limit was obtained with the Cosmic Background Imager, a 13 element interferometer which operates in the 26-36 GHz band from a site at 5000m in northern Chile. The array consists of 90-cm Cassegrain antennas mounted on a single, fully steerable platform; this platform can be rotated about the optical axis to facilitate <span class="hlt">polarization</span> observations. The CBI employs single mode circularly <span class="hlt">polarized</span> receivers, of which 12 are configured for LCP and one is configured for RCP. The 12 cross <span class="hlt">polarized</span> baselines sample multipoles from l ~600 to l ~3500. The instrumental <span class="hlt">polarization</span> of the CBI was calibrated with observations of 3C279, a <span class="hlt">bright</span> <span class="hlt">polarized</span> source which is unresolved by the CBI. Because the centimeter flux of 3C279 is variable, it was monitored twice per month for 8 months in '00 with the VLA at 22 and 43 GHz. These observations also established the stability of the <span class="hlt">polarization</span> characteristics of the CBI. This work was made possible by NSF grant AST-9802989</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhLA..381.3000L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhLA..381.3000L"><span>Tailoring <span class="hlt">polarization</span> of electromagnetically induced transparency based on non-centrosymmetric metasurfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Hai-ming; Xue, Feng</p> <p>2017-09-01</p> <p>In this manuscript, tailoring <span class="hlt">polarization</span> of analogy of electromagnetically induced transparency (EIT-like) based on non-centrosymmetric metasurfaces has been numerically and experimentally demonstrated. The EIT-like metamaterial is composed of a rectangle ring and two cut wires. The rectangle ring and the cut wire are chosen as the <span class="hlt">bright</span> mode and the quasi-dark mode, respectively. Under the incident electromagnetic wave excitation, a <span class="hlt">polarization</span> insensitive EIT-like transmission window can be observed at specific <span class="hlt">polarization</span> angles. Within the transmission window, the phase steeply changes, which leads to the large group index. Tailoring <span class="hlt">polarization</span> of EIT-like metamaterial with large group index at specific <span class="hlt">polarization</span> angles may have potential application in slow light devices.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA06801&hterms=CAPS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DCAPS','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA06801&hterms=CAPS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DCAPS"><span><span class="hlt">Polar</span> Cap Retreat</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2004-01-01</p> <p><p/> 13 August 2004 This red wide angle Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a view of the retreating seasonal south <span class="hlt">polar</span> cap in the most recent spring in late 2003. <span class="hlt">Bright</span> areas are covered with frost, dark areas are those from which the solid carbon dioxide has sublimed away. The center of this image is located near 76.5oS, 28.2oW. The scene is large; it covers an area about 250 km (155 mi) across. The scene is illuminated by sunlight from the upper left.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28488591','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28488591"><span>Red-emission phosphor's <span class="hlt">brightness</span> deterioration by x-ray and <span class="hlt">brightness</span> recovery phenomenon by heating.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nakamura, Masaaki; Chida, Koichi; Inaba, Yohei; Kobayashi, Ryota; Zuguchi, Masayuki</p> <p>2017-06-26</p> <p>There are no feasible real-time and direct skin dosimeters for interventional radiology. One would be available if there were x-ray phosphors that had no <span class="hlt">brightness</span> change caused by x-ray irradiation, but the emission of the Y 2 O 3 :Eu, (Y, Gd, Eu)BO 3 , and YVO 4 :Eu phosphors investigated in our previous study was reduced by x-ray irradiation. We found that the <span class="hlt">brightness</span> of those phosphors recovered, and the purpose of this study is to investigate their recovery phenomena. It is expected that more kinds of phosphors could be used in x-ray dosimeters if the <span class="hlt">brightness</span> changes caused by x-rays are elucidated and prevented. Three kinds of phosphors-Y 2 O 3 :Eu, (Y, Gd, Eu)BO 3 , and YVO 4 :Eu-were irradiated by x-rays (2 Gy) to reduce their <span class="hlt">brightness</span>. After the irradiation, <span class="hlt">brightness</span> changes occurring at room temperature and at 80 °C were investigated. The irradiation reduced the <span class="hlt">brightness</span> of all the phosphors by 5%-10%, but the <span class="hlt">brightness</span> of each recovered immediately both at room temperature and at 80 °C. The recovery at 80 °C was faster than that at room temperature, and at both temperatures the recovered <span class="hlt">brightness</span> remained at 95%-98% of the <span class="hlt">brightness</span> before the x-ray irradiation. The <span class="hlt">brightness</span> recovery phenomena of Y 2 O 3 :Eu, (Y, Gd, Eu)BO 3 , and YVO 4 :Eu phosphors occurring after <span class="hlt">brightness</span> deterioration due to x-ray irradiation were found to be more significant at 80 °C than at room temperature. More kinds of phosphors could be used in x-ray scintillation dosimeters if the reasons for the <span class="hlt">brightness</span> changes caused by x-rays were elucidated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70022934','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70022934"><span>Surface properties of Mars' <span class="hlt">polar</span> layered deposits and <span class="hlt">polar</span> landing sites</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Vasavada, Ashwin R.; Williams, Jean-Pierre; Paige, David A.; Herkenhoff, Ken E.; Bridges, Nathan T.; Greeley, Ronald; Murray, Bruce C.; Bass, Deborah S.; McBride, Karen S.</p> <p>2000-01-01</p> <p>On December 3, 1999, the Mars <span class="hlt">Polar</span> Lander and Mars Microprobes will land on the planet's south <span class="hlt">polar</span> layered deposits near (76°S, 195°W) and conduct the first in situ studies of the planet's <span class="hlt">polar</span> regions. The scientific goals of these missions address several poorly understood and globally significant issues, such as <span class="hlt">polar</span> meteorology, the composition and volatile content of the layered deposits, the erosional state and mass balance of their surface, their possible relationship to climate cycles, and the nature of <span class="hlt">bright</span> and dark aeolian material. Derived thermal inertias of the southern layered deposits are very low (50-100 J m-2 s-1/2 K-1), suggesting that the surface down to a depth of a few centimeters is generally fine grained or porous and free of an appreciable amount of rock or ice. The landing site region is smoother than typical cratered terrain on ∼1 km pixel-1 Viking Orbiter images but contains low-relief texture on ∼5 to 100 m pixel-1 Mariner 9 and Mars Global Surveyor images. The surface of the southern deposits is older than that of the northern deposits and appears to be modified by aeolian erosion or ablation of ground ice.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-s30-86-024.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-s30-86-024.html"><span><span class="hlt">Polarized</span> Light Experiment, Presa Don Martin, Coahuila, Mexico</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>1989-05-08</p> <p>This is a single scene from a pair (frames 021 & 024) to study the effects of <span class="hlt">polarized</span> light in Earth Observations. One scene was exposed with vertically <span class="hlt">polarized</span> light, the other, <span class="hlt">horizontally</span>. The subject in this study, is a lake behind Presa (dam) Don Martin (27.5N, 100.5W) on the edge of the Rio Grande Plain near it's boundry with the Sierra Madre Orientral in Coahuila, Mexico.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000prat.conf..323H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000prat.conf..323H"><span>Self-Calibration in the Ska: Dealing with Inherently Strong Instrumental <span class="hlt">Polarization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hamaker, Johan</p> <p></p> <p>The <span class="hlt">polarization</span> properties of a phased-array SKA will depart radically from those we are familiar with. The E- and H-plane beams of a linear or planar dipole are very different and the primary beam formed by arrays of such dipoles is strongly <span class="hlt">polarized</span>. The customary quasi-scalar description is inadequate: <span class="hlt">Polarization</span> must be accounted for in a fundamental way. Once this is done, we must investigate whether or not a phased-array SKA will in principle be capable of achievements comparable to those of conventional synthesis arrays. Selfcal is crucial to these achievements. In this paper I address the vital question of its viability in the presence of arbitrary instrumental <span class="hlt">polarization</span>. I introduce an interferometer description based on 2x2 matrices. I then propose a matrix-based self-calibration method that is entirely analogous to the scalar one. I show that the standard selfcal assumptions suppress spatial scattering in matrix selfcal like they do in scalar selfcal: Thus the basic condition for obtaining images with a high dynamic range is satisfied. However, matrix selfcal alone cannot guarantee the polarimetric fidelity of the image: It introduces an unknown polrotation of the Stokes (Q,U,V) <span class="hlt">brightness</span> vector and an unknown polconversion between unpolarized and <span class="hlt">polarized</span> <span class="hlt">brightness</span>. Methods similar to those currently applied in quasi-scalar polarimetry must be applied to reduce these poldistorsions to an acceptable level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4834751','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4834751"><span>Circadian Phase-Shifting Effects of <span class="hlt">Bright</span> Light, Exercise, and <span class="hlt">Bright</span> Light + Exercise</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kline, Christopher E.; Elliott, Jeffrey A.; Zielinski, Mark R.; Devlin, Tina M.; Moore, Teresa A.</p> <p>2016-01-01</p> <p>Limited research has compared the circadian phase-shifting effects of <span class="hlt">bright</span> light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night <span class="hlt">bright</span> light, late night exercise, and late evening <span class="hlt">bright</span> light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) <span class="hlt">bright</span> light alone (5,000 lux) from 2210–2340 h, (2) treadmill exercise alone from 2210–2340 h, or (3) <span class="hlt">bright</span> light (2210–2340 h) followed by exercise from 0410–0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of <span class="hlt">bright</span> light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following <span class="hlt">bright</span> light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night <span class="hlt">bright</span> light followed by early morning exercise can have an additive circadian phase-shifting effect. PMID:27103935</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9348E..0VL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9348E..0VL"><span>High-<span class="hlt">brightness</span> 9xxnm fiber coupled diode lasers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Rui; Jiang, Xiaochen; Yang, Thomas; He, Xiaoguang; Gao, Yanyan; Zhu, Jing; Zhang, Tujia; Guo, Weirong; Wang, Baohua; Guo, Zhijie; Zhang, Luyan; Chen, Louisa</p> <p>2015-03-01</p> <p>We developed a high <span class="hlt">brightness</span> fiber coupled diode laser module providing more than 140W output power from a 105μm NA 0.15 fiber at the wavelength of 915nm.The high <span class="hlt">brightness</span> module has an electrical to optical efficiency better than 45% and power enclosure more than 90% within NA 0.13. It is based on multi-single emitters using optical and <span class="hlt">polarization</span> beam combining and fiber coupling technique. With the similar technology, over 100W of optical power into a 105μm NA 0.15 fiber at 976nm is also achieved which can be compatible with the volume Bragg gratings to receive narrow and stabilized spectral linewidth. The light within NA 0.12 is approximately 92%. The reliability test data of single and multiple single emitter laser module under high optical load are also presented and analyzed using a reliability model with an emitting aperture optimized for coupling into 105μm core fiber. The total MTTF shows exceeding 100,000 hours within 60% confidence level. The packaging processes and optical design are ready for commercial volume production.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28533509','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28533509"><span>Vector Beam <span class="hlt">Polarization</span> State Spectrum Analyzer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Moreno, Ignacio; Davis, Jeffrey A; Badham, Katherine; Sánchez-López, María M; Holland, Joseph E; Cottrell, Don M</p> <p>2017-05-22</p> <p>We present a proof of concept for a vector beam <span class="hlt">polarization</span> state spectrum analyzer based on the combination of a <span class="hlt">polarization</span> diffraction grating (PDG) and an encoded harmonic q-plate grating (QPG). As a result, a two-dimensional <span class="hlt">polarization</span> diffraction grating is formed that generates six different q-plate channels with topological charges from -3 to +3 in the <span class="hlt">horizontal</span> direction, and each is split in the vertical direction into the six <span class="hlt">polarization</span> channels at the cardinal points of the corresponding higher-order Poincaré sphere. Consequently, 36 different channels are generated in parallel. This special <span class="hlt">polarization</span> diffractive element is experimentally demonstrated using a single phase-only spatial light modulator in a reflective optical architecture. Finally, we show that this system can be used as a vector beam <span class="hlt">polarization</span> state spectrum analyzer, where both the topological charge and the state of <span class="hlt">polarization</span> of an input vector beam can be simultaneously determined in a single experiment. We expect that these results would be useful for applications in optical communications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9876E..1DK','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9876E..1DK"><span>Impact of <span class="hlt">horizontal</span> and vertical localization scales on microwave sounder SAPHIR radiance assimilation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krishnamoorthy, C.; Balaji, C.</p> <p>2016-05-01</p> <p>In the present study, the effect of <span class="hlt">horizontal</span> and vertical localization scales on the assimilation of direct SAPHIR radiances is studied. An Artificial Neural Network (ANN) has been used as a surrogate for the forward radiative calculations. The training input dataset for ANN consists of vertical layers of atmospheric pressure, temperature, relative humidity and other hydrometeor profiles with 6 channel <span class="hlt">Brightness</span> Temperatures (BTs) as output. The best neural network architecture has been arrived at, by a neuron independence study. Since vertical localization of radiance data requires weighting functions, a ANN has been trained for this purpose. The radiances were ingested into the NWP using the Ensemble Kalman Filter (EnKF) technique. The <span class="hlt">horizontal</span> localization has been taken care of, by using a Gaussian localization function centered around the observed coordinates. Similarly, the vertical localization is accomplished by assuming a function which depends on the weighting function of the channel to be assimilated. The effect of both <span class="hlt">horizontal</span> and vertical localizations has been studied in terms of ensemble spread in the precipitation. Aditionally, improvements in 24 hr forecast from assimilation are also reported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29650753','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29650753"><span><span class="hlt">Polarized</span> object detection in crabs: a two-channel system.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Basnak, Melanie Ailín; Pérez-Schuster, Verónica; Hermitte, Gabriela; Berón de Astrada, Martín</p> <p>2018-05-25</p> <p>Many animal species take advantage of <span class="hlt">polarization</span> vision for vital tasks such as orientation, communication and contrast enhancement. Previous studies have suggested that decapod crustaceans use a two-channel <span class="hlt">polarization</span> system for contrast enhancement. Here, we characterize the <span class="hlt">polarization</span> contrast sensitivity in a grapsid crab . We estimated the <span class="hlt">polarization</span> contrast sensitivity of the animals by quantifying both their escape response and changes in heart rate when presented with <span class="hlt">polarized</span> motion stimuli. The motion stimulus consisted of an expanding disk with an 82 deg <span class="hlt">polarization</span> difference between the object and the background. More than 90% of animals responded by freezing or trying to avoid the <span class="hlt">polarized</span> stimulus. In addition, we co-rotated the electric vector (e-vector) orientation of the light from the object and background by increments of 30 deg and found that the animals' escape response varied periodically with a 90 deg period. Maximum escape responses were obtained for object and background e-vectors near the vertical and <span class="hlt">horizontal</span> orientations. Changes in cardiac response showed parallel results but also a minimum response when e-vectors of object and background were shifted by 45 deg with respect to the maxima. These results are consistent with an orthogonal receptor arrangement for the detection of <span class="hlt">polarized</span> light, in which two channels are aligned with the vertical and <span class="hlt">horizontal</span> orientations. It has been hypothesized that animals with object-based <span class="hlt">polarization</span> vision rely on a two-channel detection system analogous to that of color processing in dichromats. Our results, obtained by systematically varying the e-vectors of object and background, provide strong empirical support for this theoretical model of <span class="hlt">polarized</span> object detection. © 2018. Published by The Company of Biologists Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000PhRvB..62.2271Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000PhRvB..62.2271Z"><span>Evidence for a shear <span class="hlt">horizontal</span> resonance in supported thin films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, X.; Manghnani, M. H.; Every, A. G.</p> <p>2000-07-01</p> <p>We report evidence for a different type of acoustic film excitation, identified as a shear <span class="hlt">horizontal</span> resonance, in amorphous silicon oxynitride films on GaAs substrate. Observation of this excitation has been carried out using surface Brillouin scattering of light. A Green's function formalism is used for analyzing the experimental spectra, and successfully simulates the spectral features associated with this mode. The attributes of this mode are described; these include its phase velocity which is nearly equal to that of a bulk shear wave propagating parallel to the surface and is almost independent of film thickness and scattering angle, its localization mainly in the film, and its <span class="hlt">polarization</span> in the shear <span class="hlt">horizontal</span> direction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910069806&hterms=gaines&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dk.%2Bgaines','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910069806&hterms=gaines&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dk.%2Bgaines"><span><span class="hlt">Horizontal</span> wind fluctuations in the stratosphere during large-scale cyclogenesis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chan, K. R.; Scott, S. G.; Danielsen, Edwin F.; Pfister, L.; Bowen, S. W.; Gaines, Steven E.</p> <p>1991-01-01</p> <p>The meteorological measurement system (MMS) on the U-2 aircraft measured pressure, temperature, and the <span class="hlt">horizontal</span> wind during a cyclogenesis event over western United States on April 20, 1984. The mean <span class="hlt">horizontal</span> wind in the stratosphere decreases monotonically with altitude. Superimposed on the mean stratospheric wind is a perturbation wind vector, which is an elliptically <span class="hlt">polarized</span> wave with an amplitude of 4 to 10 m/s and a vertical wavelength of 2 to 3 km. The perturbation wind vector rotates anticyclonically (clockwise) with altitude and produces alternating advection in the plane of the aircraft flight path. This differential advection folds surfaces of constant tracer mixing ratio and contributes to the observed tracer laminar structures and inferred cross-jet transport.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27554649','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27554649"><span><span class="hlt">Polarization</span> vision seldom increases the sighting distance of silvery fish.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Johnsen, Sönke; Gagnon, Yakir L; Marshall, N Justin; Cronin, Thomas W; Gruev, Viktor; Powell, Samuel</p> <p>2016-08-22</p> <p>Although the function of <span class="hlt">polarization</span> vision, the ability to discern the <span class="hlt">polarization</span> characteristics of light, is well established in many terrestrial and benthic species, its purpose in pelagic species (squid and certain fish and crustaceans) is poorly understood [1]. A long-held hypothesis is that <span class="hlt">polarization</span> vision in open water is used to break the mirror camouflage of silvery fish, as biological mirrors can change the <span class="hlt">polarization</span> of reflected light [2,3]. Although, the addition of <span class="hlt">polarization</span> information may increase the conspicuousness of silvery fish at close range, direct evidence that silvery fish - or indeed any pelagic animal - are visible at longer distances using <span class="hlt">polarization</span> vision rather than using radiance (i.e. <span class="hlt">brightness</span>) vision is lacking. Here we show, using in situ <span class="hlt">polarization</span> imagery and a new visual detection model, that <span class="hlt">polarization</span> vision does not in fact appear to allow viewers to see silvery fish at greater distances. Copyright © 2016 Elsevier Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870005717','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870005717"><span>Ephemeral active regions and coronal <span class="hlt">bright</span> points: A solar maximum Mission 2 guest investigator study</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Harvey, K. L.; Tang, F. Y. C.; Gaizauskas, V.; Poland, A. I.</p> <p>1986-01-01</p> <p>A dominate association of coronal <span class="hlt">bright</span> points (as seen in He wavelength 10830) was confirmed with the approach and subsequent disappearance of opposite <span class="hlt">polarity</span> magnetic network. While coronal <span class="hlt">bright</span> points do occur with ephemeral regions, this association is a factor of 2 to 4 less than with sites of disappearing magnetic flux. The intensity variations seen in He I wavelength 10830 are intermittent and often rapid, varying over the 3 minute time resolution of the data; their <span class="hlt">bright</span> point counterparts in the C IV wavelength 1548 and 20 cm wavelength show similar, though not always coincident time variations. Ejecta are associated with about 1/3 of the dark points and are evident in the C IV and H alpha data. These results support the idea that the anti-correlation of X-ray <span class="hlt">bright</span> points with the solar cycle can be explained by the correlation of these coronal emission structures with sites of cancelling flux, indicating that, in some cases, the process of magnetic flux removal results in the release of energy. That the intensity variations are rapid and variable suggests that this process works intermittently.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171254','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171254"><span>Note on the Effect of <span class="hlt">Horizontal</span> Gradients for Nadir-Viewing Microwave and Infrared Sounders</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Joiner, J.; Poli, P.</p> <p>2004-01-01</p> <p>Passive microwave and infrared nadir sounders such as the Advanced Microwave Sounding Unit A (AMSU-A) and the Atmospheric InfraRed Sounder (AIRS), both flying on NASA s EOS Aqua satellite, provide information about vertical temperature and humidity structure that is used in data assimilation systems for numerical weather prediction and climate applications. These instruments scan cross track so that at the satellite swath edges, the satellite zenith angles can reach approx. 60 deg. The emission path through the atmosphere as observed by the satellite is therefore slanted with respect to the satellite footprint s zenith. Although radiative transfer codes currently in use at operational centers use the appropriate satellite zenith angle to compute <span class="hlt">brightness</span> temperature, the input atmospheric fields are those from the vertical profile above the center of the satellite footprint. If <span class="hlt">horizontal</span> gradients are present in the atmospheric fields, the use of a vertical atmospheric profile may produce an error. This note attempts to quantify the effects of <span class="hlt">horizontal</span> gradients on AIRS and AMSU-A channels by computing <span class="hlt">brightness</span> temperatures with accurate slanted atmospheric profiles. We use slanted temperature, water vapor, and ozone fields from data assimilation systems. We compare the calculated slanted and vertical <span class="hlt">brightness</span> temperatures with AIRS and AMSU-A observations. We show that the effects of <span class="hlt">horizontal</span> gradients on these sounders are generally small and below instrument noise. However, there are cases where the effects are greater than the instrument noise and may produce erroneous increments in an assimilation system. The majority of the affected channels have weighting functions that peak in the upper troposphere (water vapor sensitive channels) and above (temperature sensitive channels) and are unlikely t o significantly impact tropospheric numerical weather prediction. However, the errors could be significant for other applications such as stratospheric</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890016904','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890016904"><span><span class="hlt">Polar</span> microwave <span class="hlt">brightness</span> temperatures from Nimbus-7 SMMR: Time series of daily and monthly maps from 1978 to 1987</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Comiso, Josefino C.; Zwally, H. Jay</p> <p>1989-01-01</p> <p>A time series of daily <span class="hlt">brightness</span> temperature gridded maps (October 25, 1978 through August 15, 1987) were generated from all ten channels of the Nimbus-7 Scanning Multichannel Microwave Radiometer orbital data. This unique data set can be utilized in a wide range of applications including heat flux, ocean circulation, ice edge productivity, and climate studies. Two sets of data in <span class="hlt">polar</span> stereographic format are created for the Arctic region: one with a grid size of about 30 km on a 293 by 293 array similar to that previously utilized for the Nimbus-5 Electrically Scanning Microwave Radiometer, while the other has a grid size of about 25 km on a 448 by 304 array identical to what is now being used for the DMSP Scanning Multichannel Microwave Imager. Data generated for the Antaractic region are mapped using the 293 by 293 grid only. The general technique for mapping, and a quality assessment of the data set are presented. Monthly and yearly averages are also generated from the daily data and sample geophysical ice images and products derived from the data are given. Contour plots of monthly ice concentrations derived from the data for October 1978 through August 1987 are presented to demonstrate spatial and temporal detail which this data set can offer, and to show potential research applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.8121L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.8121L"><span>Relative importance of <span class="hlt">horizontal</span> and vertical transports to the formation of ionospheric storm-enhanced density and <span class="hlt">polar</span> tongue of ionization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Jing; Wang, Wenbin; Burns, Alan; Solomon, Stanley C.; Zhang, Shunrong; Zhang, Yongliang; Huang, Chaosong</p> <p>2016-08-01</p> <p>There are still uncertainties regarding the formation mechanisms for storm-enhanced density (SED) in the high and subauroral latitude ionosphere. In this work, we deploy the Thermosphere Ionosphere Electrodynamic General Circulation Model (TIEGCM) and GPS total electron content (TEC) observations to identify the principle mechanisms for SED and the tongue of ionization (TOI) through term-by-term analysis of the ion continuity equation and also identify the advantages and deficiencies of the TIEGCM in capturing high-latitude and subauroral latitude ionospheric fine structures for the two geomagnetic storm events occurring on 17 March 2013 and 2015. Our results show that in the topside ionosphere, upward E × B ion drifts are most important in SED formation and are offset by antisunward neutral winds and downward ambipolar diffusion effects. In the bottomside F region ionosphere, neutral winds play a major role in generating SEDs. SED signature in TEC is mainly caused by upward E × B ion drifts that lift the ionosphere to higher altitudes where chemical recombination is slower. <span class="hlt">Horizontal</span> E × B ion drifts play an essential role in transporting plasma from the dayside convection throat region to the <span class="hlt">polar</span> cap to form TOIs. Inconsistencies between model results and GPS TEC data were found: (1) GPS relative TEC difference between storm time and quiet time has "holes" in the dayside ion convection entrance region, which do not appear in the model results. (2) The model tends to overestimate electron density enhancements in the <span class="hlt">polar</span> region. Possible causes for these inconsistencies are discussed in this article.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SPIE.5888...86F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SPIE.5888...86F"><span>Use of <span class="hlt">polarization</span> to improve signal to clutter ratio in an outdoor active imaging system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fontoura, Patrick F.; Giles, Michael K.; Padilla, Denise D.</p> <p>2005-08-01</p> <p>This paper describes the methodology and presents the results of the design of a <span class="hlt">polarization</span>-sensitive system used to increase the signal-to-clutter ratio in a robust outdoor structured lighting sensor that uses standard CCD camera technology. This lighting sensor is intended to be used on an autonomous vehicle, looking down to the ground and <span class="hlt">horizontal</span> to obstacles in an 8 foot range. The kinds of surfaces to be imaged are natural and man-made, such as asphalt, concrete, dirt and grass. The main problem for an outdoor eye-safe laser imaging system is that the reflected energy from background clutter tends to be brighter than the reflected laser energy. A narrow-band optical filter does not reduce significantly the background clutter in <span class="hlt">bright</span> sunlight, and problems also occur when the surface is highly absorptive, like asphalt. Therefore, most of applications are limited to indoor and controlled outdoor conditions. A series of measurements was made for each of the materials studied in order to find the best configuration for the <span class="hlt">polarizing</span> system and also to find out the potential improvement in the signal-to-clutter ratio (STC). This process was divided into three parts: characterization of the reflected sunlight, characterization of the reflected laser light, and measurement of the improvement in the STC. The results show that by using <span class="hlt">polarization</span> properties it is possible to design an optical system that is able to increase the signal-to-clutter ratio from approximately 30% to 100% in the imaging system, depending on the kind of surface and on the incidence angle of the sunlight. The technique was also analyzed for indoor use, with the background clutter being the room illumination. For this specific case, <span class="hlt">polarization</span> did not improve the signal-to-clutter ratio.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19243743','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19243743"><span>A selective deficit in the appreciation and recognition of <span class="hlt">brightness</span>: <span class="hlt">brightness</span> agnosia?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nijboer, Tanja C W; Nys, Gudrun M S; van der Smagt, Maarten J; de Haan, Edward H F</p> <p>2009-01-01</p> <p>We report a patient with extensive brain damage in the right hemisphere who demonstrated a severe impairment in the appreciation of <span class="hlt">brightness</span>. Acuity, contrast sensitivity as well as luminance discrimination were normal, suggesting her <span class="hlt">brightness</span> impairment is not a mere consequence of low-level sensory impairments. The patient was not able to indicate the darker or the lighter of two grey squares, even though she was able to see that they differed. In addition, she could not indicate whether the lights in a room were switched on or off, nor was she able to differentiate between normal greyscale images and inverted greyscale images. As the patient recognised objects, colours, and shapes correctly, the impairment is specific for <span class="hlt">brightness</span>. As low-level, sensory processing is normal, this specific deficit in the recognition and appreciation of <span class="hlt">brightness</span> appears to be of a higher, cognitive level, the level of semantic knowledge. This appears to be the first report of '<span class="hlt">brightness</span> agnosia'.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApJ...856..156E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApJ...856..156E"><span>Unlocking the Full Potential of Extragalactic Lyα through Its <span class="hlt">Polarization</span> Properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Eide, Marius B.; Gronke, Max; Dijkstra, Mark; Hayes, Matthew</p> <p>2018-04-01</p> <p>Lyα is a powerful astrophysical probe. Not only is it ubiquitous at high redshifts, it is also a resonant line, making Lyα photons scatter. This scattering process depends on the physical conditions of the gas through which Lyα propagates, and these conditions are imprinted on observables such as the Lyα spectrum and its surface <span class="hlt">brightness</span> profile. In this work, we focus on a less-used observable capable of probing any scattering process: <span class="hlt">polarization</span>. We implement the density matrix formalism of <span class="hlt">polarization</span> into the Monte Carlo radiative transfer code tlac. This allows us to treat it as a quantum mechanical process where single photons develop and lose <span class="hlt">polarization</span> from scatterings in arbitrary gas geometries. We explore static and expanding ellipsoids, biconical outflows, and clumpy multiphase media. We find that photons become increasingly <span class="hlt">polarized</span> as they scatter and diffuse into the wings of the line profiles, making scattered Lyα <span class="hlt">polarized</span> in general. The degree and orientation of Lyα <span class="hlt">polarization</span> depends on the kinematics and distribution of the scattering H I gas. We find that it generally probes spatial or velocity space asymmetries and aligns itself tangentially to the emission source. We show that the mentioned observables, when studied separately, can leave similar signatures for different source models. We conclude by revealing how a joint analysis of the Lyα spectra, surface <span class="hlt">brightness</span> profiles, and <span class="hlt">polarization</span> can break these degeneracies and help us extract unique physical information on galaxies and their environments from their strongest, most prominent emission line.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999AdSpR..23.2033M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999AdSpR..23.2033M"><span>Auxin <span class="hlt">polar</span> transport in arabidopsis under simulated microgravity conditions - relevance to growth and development</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miyamoto, K.; Oka, M.; Yamamoto, R.; Masuda, Y.; Hoson, T.; Kamisaka, S.; Ueda, J.</p> <p>1999-01-01</p> <p>Activity of auxin <span class="hlt">polar</span> transport in inflorescence axes of Arabidopsis thaliana grown under simulated microgravity conditions was studied in relation to the growth and development. Seeds were germinated and allowed to grow on an agar medium in test tubes on a <span class="hlt">horizontal</span> clinostat. <span class="hlt">Horizontal</span> clinostat rotation substantially reduced the growth of inflorescence axes and the productivity of seeds of Arabidopsis thaliana (ecotypes Landsberg erecta and Columbia), although it little affected seed germination, development of rosette leaves and flowering. The activity of auxin <span class="hlt">polar</span> transport in inflorescence axes decreased when Arabidopsis plants were grown on a <span class="hlt">horizontal</span> clinostat from germination stage, being ca. 60% of 1 g control. On the other hand, the auxin <span class="hlt">polar</span> transport in inflorescence axes of Arabidopsis grown in 1 g conditions was not affected when the segments were exposed to various gravistimuli, including 3-dimensional clinorotation, during transport experiments. Pin-formed mutant of Arabidopsis, having a unique structure of the inflorescence axis with no flower and extremely low levels of the activity of auxin <span class="hlt">polar</span> transport in inflorescence axes and endogenous auxin, did not continue its vegetative growth under clinostat rotation. These facts suggest that the development of the system of auxin <span class="hlt">polar</span> transport in Arabidopsis is affected by microgravity, resulting in the inhibition of growth and development, especially during reproductive growth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017Galax...5...93P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017Galax...5...93P"><span>Linear <span class="hlt">Polarization</span> Properties of Parsec-Scale AGN Jets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pushkarev, Alexander; Kovalev, Yuri; Lister, Matthew; Savolainen, Tuomas; Aller, Margo; Aller, Hugh; Hodge, Mary</p> <p>2017-12-01</p> <p>We used 15 GHz multi-epoch Very Long Baseline Array (VLBA) <span class="hlt">polarization</span> sensitive observations of 484 sources within a time interval 1996--2016 from the MOJAVE program, and also from the NRAO data archive. We have analyzed the linear <span class="hlt">polarization</span> characteristics of the compact core features and regions downstream, and their changes along and across the parsec-scale active galactic nuclei (AGN) jets. We detected a significant increase of fractional <span class="hlt">polarization</span> with distance from the radio core along the jet as well as towards the jet edges. Compared to quasars, BL Lacs have a higher degree of <span class="hlt">polarization</span> and exhibit more stable electric vector position angles (EVPAs) in their core features and a better alignment of the EVPAs with the local jet direction. The latter is accompanied by a higher degree of linear <span class="hlt">polarization</span>, suggesting that compact <span class="hlt">bright</span> jet features might be strong transverse shocks, which enhance magnetic field regularity by compression.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950029679&hterms=peak+detectioN&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dpeak%2BdetectioN','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950029679&hterms=peak+detectioN&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dpeak%2BdetectioN"><span>Detection of 17 GHz radio emission from X-ray-<span class="hlt">bright</span> points</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kundu, M. R.; Shibasaki, K.; Enome, S.; Nitta, N.</p> <p>1994-01-01</p> <p>Using observations made with the Nobeyama radio heliograph (NRH) at 17 GHz and the Yohkoh/SXT experiment, we report the first detection of 17 GHz signatures of coronal X-ray-<span class="hlt">bright</span> points (XBPs). This is also the first reported detection of flaring <span class="hlt">bright</span> points in microwaves. We have detected four BPs at 17 GHz out of eight identified in SXT data on 1992 July 31, for which we looked for 17 GHz emission. For one XBP located in a quiet mixed-<span class="hlt">polarity</span> region, the peak times at 17 GHz and X-rays are very similar, and both are long-lasting-about 2 hr in duration. There is a second BP (located near an active region) which is most likely flaring also, but the time profiles in the two spectral domains are not similar. The other two 17 GHz BPs are quiescent with fluctuations superposed upon them. For the quiet region XBP, the gradual, long-lasting, and unpolarized emission suggests that the 17 GHz emission is thermal.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140012069','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140012069"><span>Optimization of a Radiative Transfer Forward Operator for Simulating SMOS <span class="hlt">Brightness</span> Temperatures over the Upper Mississippi Basin, USA</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lievens, H.; Verhoest, N. E. C.; Martens, B.; VanDenBerg, M. J.; Bitar, A. Al; Tomer, S. Kumar; Merlin, O.; Cabot, F.; Kerr, Y.; DeLannoy, G. J. M.; <a style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20140012069'); toggleEditAbsImage('author_20140012069_show'); toggleEditAbsImage('author_20140012069_hide'); "> <img style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20140012069_show"> <img style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20140012069_hide"></p> <p>2014-01-01</p> <p>The Soil Moisture and Ocean Salinity (SMOS) satellite mission is routinely providing global multi-angular observations of <span class="hlt">brightness</span> temperature (TB) at both <span class="hlt">horizontal</span> and vertical <span class="hlt">polarization</span> with a 3-day repeat period. The assimilation of such data into a land surface model (LSM) may improve the skill of operational flood forecasts through an improved estimation of soil moisture (SM). To accommodate for the direct assimilation of the SMOS TB data, the LSM needs to be coupled with a radiative transfer model (RTM), serving as a forward operator for the simulation of multi-angular and multi-<span class="hlt">polarization</span> top of atmosphere TBs. This study investigates the use of the Variable Infiltration Capacity (VIC) LSM coupled with the Community Microwave Emission Modelling platform (CMEM) for simulating SMOS TB observations over the Upper Mississippi basin, USA. For a period of 2 years (2010-2011), a comparison between SMOS TBs and simulations with literature-based RTM parameters reveals a basin averaged bias of 30K. Therefore, time series of SMOS TB observations are used to investigate ways for mitigating these large biases. Specifically, the study demonstrates the impact of the LSM soil moisture climatology in the magnitude of TB biases. After CDF matching the SM climatology of the LSM to SMOS retrievals, the average bias decreases from 30K to less than 5K. Further improvements can be made through calibration of RTM parameters related to the modeling of surface roughness and vegetation. Consequently, it can be concluded that SM rescaling and RTM optimization are efficient means for mitigating biases and form a necessary preparatory step for data assimilation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22660931-systematic-study-gamma-ray-bright-blazars-optical-polarization-gamma-ray-variability','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22660931-systematic-study-gamma-ray-bright-blazars-optical-polarization-gamma-ray-variability"><span>SYSTEMATIC STUDY OF GAMMA-RAY-<span class="hlt">BRIGHT</span> BLAZARS WITH OPTICAL <span class="hlt">POLARIZATION</span> AND GAMMA-RAY VARIABILITY</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Itoh, Ryosuke; Fukazawa, Yasushi; Kanda, Yuka</p> <p></p> <p>Blazars are highly variable active galactic nuclei that emit radiation at all wavelengths from radio to gamma rays. <span class="hlt">Polarized</span> radiation from blazars is one key piece of evidence for synchrotron radiation at low energies, and it also varies dramatically. The <span class="hlt">polarization</span> of blazars is of interest for understanding the origin, confinement, and propagation of jets. However, even though numerous measurements have been performed, the mechanisms behind jet creation, composition, and variability are still debated. We performed simultaneous gamma-ray and optical photopolarimetry observations of 45 blazars between 2008 July and 2014 December to investigate the mechanisms of variability and search formore » a basic relation between the several subclasses of blazars. We identify a correlation between the maximum degree of optical linear <span class="hlt">polarization</span> and the gamma-ray luminosity or the ratio of gamma-ray to optical fluxes. Since the maximum <span class="hlt">polarization</span> degree depends on the condition of the magnetic field (chaotic or ordered), this result implies a systematic difference in the intrinsic alignment of magnetic fields in parsec-scale relativistic jets between different types of blazars (flat-spectrum radio quasars vs. BL Lacs) and consequently between different types of radio galaxies (FR I versus FR II).« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4788484','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4788484"><span>Tomographic reconstruction of circularly <span class="hlt">polarized</span> high-harmonic fields: 3D attosecond metrology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chen, Cong; Tao, Zhensheng; Hernández-García, Carlos; Matyba, Piotr; Carr, Adra; Knut, Ronny; Kfir, Ofer; Zusin, Dimitry; Gentry, Christian; Grychtol, Patrik; Cohen, Oren; Plaja, Luis; Becker, Andreas; Jaron-Becker, Agnieszka; Kapteyn, Henry; Murnane, Margaret</p> <p>2016-01-01</p> <p><span class="hlt">Bright</span>, circularly <span class="hlt">polarized</span>, extreme ultraviolet (EUV) and soft x-ray high-harmonic beams can now be produced using counter-rotating circularly <span class="hlt">polarized</span> driving laser fields. Although the resulting circularly <span class="hlt">polarized</span> harmonics consist of relatively simple pairs of peaks in the spectral domain, in the time domain, the field is predicted to emerge as a complex series of rotating linearly <span class="hlt">polarized</span> bursts, varying rapidly in amplitude, frequency, and <span class="hlt">polarization</span>. We extend attosecond metrology techniques to circularly <span class="hlt">polarized</span> light by simultaneously irradiating a copper surface with circularly <span class="hlt">polarized</span> high-harmonic and linearly <span class="hlt">polarized</span> infrared laser fields. The resulting temporal modulation of the photoelectron spectra carries essential phase information about the EUV field. Utilizing the <span class="hlt">polarization</span> selectivity of the solid surface and by rotating the circularly <span class="hlt">polarized</span> EUV field in space, we fully retrieve the amplitude and phase of the circularly <span class="hlt">polarized</span> harmonics, allowing us to reconstruct one of the most complex coherent light fields produced to date. PMID:26989782</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26560762','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26560762"><span>High <span class="hlt">brightness</span> laser-diode device emitting 160 watts from a 100 μm/NA 0.22 fiber.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yu, Junhong; Guo, Linui; Wu, Hualing; Wang, Zhao; Tan, Hao; Gao, Songxin; Wu, Deyong; Zhang, Kai</p> <p>2015-11-10</p> <p>A practical method of achieving a high-<span class="hlt">brightness</span> and high-power fiber-coupled laser-diode device is demonstrated both by experiment and ZEMAX software simulation, which is obtained by a beam transformation system, free-space beam combining, and <span class="hlt">polarization</span> beam combining based on a mini-bar laser-diode chip. Using this method, fiber-coupled laser-diode module output power from the multimode fiber with 100 μm core diameter and 0.22 numerical aperture (NA) could reach 174 W, with equalizing <span class="hlt">brightness</span> of 14.2  MW/(cm2·sr). By this method, much wider applications of fiber-coupled laser-diodes are anticipated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EPSC...11..388G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPSC...11..388G"><span>Juno-UVS and Chandra Observations of Jupiter's <span class="hlt">Polar</span> Auroral Emissions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gladstone, G. R.; Kammer, J. A.; Versteeg, M. H.; Greathouse, T. K.; Hue, V.; Gérard, J.-C.; Grodent, D.; Bonfond, B.; Jackman, C.; Branduardi-Raymont, G.; Kraft, R. P.; Dunn, W. R.; Bolton, S. J.; Connerney, J. E. P.; Levin, S. M.; Mauk, B. H.; Valek, P.; Adriani, A.; Kurth, W. S.; Orton, G. S.</p> <p>2017-09-01</p> <p>New results are presented comparing Jupiter's auroras at far-ultraviolet and x-ray wavelengths, using data acquired by Juno-UVS and Chandra. The highly variable <span class="hlt">polar</span> auroras (which are located within the main auroral oval) track each other quite well in <span class="hlt">brightness</span> at these two wavelengths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018SPIE10514E..0YH','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018SPIE10514E..0YH"><span>Advanced chip designs and novel cooling techniques for <span class="hlt">brightness</span> scaling of industrial, high power diode laser bars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heinemann, S.; McDougall, S. D.; Ryu, G.; Zhao, L.; Liu, X.; Holy, C.; Jiang, C.-L.; Modak, P.; Xiong, Y.; Vethake, T.; Strohmaier, S. G.; Schmidt, B.; Zimer, H.</p> <p>2018-02-01</p> <p>The advance of high power semiconductor diode laser technology is driven by the rapidly growing industrial laser market, with such high power solid state laser systems requiring ever more reliable diode sources with higher <span class="hlt">brightness</span> and efficiency at lower cost. In this paper we report simulation and experimental data demonstrating most recent progress in high <span class="hlt">brightness</span> semiconductor laser bars for industrial applications. The advancements are in three principle areas: vertical laser chip epitaxy design, lateral laser chip current injection control, and chip cooling technology. With such improvements, we demonstrate disk laser pump laser bars with output power over 250W with 60% efficiency at the operating current. Ion implantation was investigated for improved current confinement. Initial lifetime tests show excellent reliability. For direct diode applications <1 um smile and >96% <span class="hlt">polarization</span> are additional requirements. Double sided cooling deploying hard solder and optimized laser design enable single emitter performance also for high fill factor bars and allow further power scaling to more than 350W with 65% peak efficiency with less than 8 degrees slow axis divergence and high <span class="hlt">polarization</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70022977','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70022977"><span>TES premapping data: Slab ice and snow flurries in the Martian north <span class="hlt">polar</span> night</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Titus, T.N.; Kieffer, H.H.; Mullins, K.F.; Christensen, P.R.</p> <p>2001-01-01</p> <p>In the 1970s, Mariner and Viking spacecraft observations of the north <span class="hlt">polar</span> region of Mars revealed <span class="hlt">polar</span> <span class="hlt">brightness</span> temperatures that were significantly below the expected kinetic temperatures for CO2 sublimation. For the past few decades, the scientific community has speculated as to the nature of these Martian <span class="hlt">polar</span> cold spots. Thermal Emission Spectrometer (TES) thermal spectral data have shown these cold spots to result largely from fine-grained, CO2 and have constrained most of these cold spots to the surface (or near-surface). Cold spot formation is strongly dependent on topography, forming preferentially near craters and on <span class="hlt">polar</span> slopes. TES data, combined with Mars Orbiter Laser Altimeter (MOLA) cloud data, suggest atmospheric condensates form a small fraction of the observed cold spots. TES observations of spectra close to a blackbody indicate that another major component of the <span class="hlt">polar</span> cap is slab CO2 ice; these spectrally bland regions commonly have a low albedo. The cause is uncertain but may result from most of the light being reflected toward the specular direction, from the slab ice being intrinsically dark, or from it being transparent. Regions of the cap where the difference between the <span class="hlt">brightness</span> temperatures at 18 ??m (T18) and 25 ??m (T25) is less than 5?? are taken to indicate deposits of slab ice. Slab ice is the dominant component of the <span class="hlt">polar</span> cap at latitudes outside of the <span class="hlt">polar</span> night. Copyright 2001 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014TCry....8..915B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014TCry....8..915B"><span>Weekly gridded Aquarius L-band radiometer/scatterometer observations and salinity retrievals over the <span class="hlt">polar</span> regions - Part 2: Initial product analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brucker, L.; Dinnat, E. P.; Koenig, L. S.</p> <p>2014-05-01</p> <p>Following the development and availability of Aquarius weekly <span class="hlt">polar</span>-gridded products, this study presents the spatial and temporal radiometer and scatterometer observations at L band (frequency ~1.4 GHz) over the cryosphere including the Greenland and Antarctic ice sheets, sea ice in both hemispheres, and over sub-Arctic land for monitoring the soil freeze/thaw state. We provide multiple examples of scientific applications for the L-band data over the cryosphere. For example, we show that over the Greenland Ice Sheet, the unusual 2012 melt event lead to an L-band <span class="hlt">brightness</span> temperature (TB) sustained decrease of ~5 K at <span class="hlt">horizontal</span> <span class="hlt">polarization</span>. Over the Antarctic ice sheet, normalized radar cross section (NRCS) observations recorded during ascending and descending orbits are significantly different, highlighting the anisotropy of the ice cover. Over sub-Arctic land, both passive and active observations show distinct values depending on the soil physical state (freeze/thaw). Aquarius sea surface salinity (SSS) retrievals in the <span class="hlt">polar</span> waters are also presented. SSS variations could serve as an indicator of fresh water input to the ocean from the cryosphere, however the presence of sea ice often contaminates the SSS retrievals, hindering the analysis. The weekly grided Aquarius L-band products used are distributed by the US Snow and Ice Data Center at <a href=" http://nsidc.org/data/aquarius/index.html "target="_blank"> http://nsidc.org/data/aquarius/index.html </a> , and show potential for cryospheric studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ApJ...796...73H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ApJ...796...73H"><span>Coronal <span class="hlt">Bright</span> Points Associated with Minifilament Eruptions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hong, Junchao; Jiang, Yunchun; Yang, Jiayan; Bi, Yi; Li, Haidong; Yang, Bo; Yang, Dan</p> <p>2014-12-01</p> <p>Coronal <span class="hlt">bright</span> points (CBPs) are small-scale, long-lived coronal brightenings that always correspond to photospheric network magnetic features of opposite <span class="hlt">polarity</span>. In this paper, we subjectively adopt 30 CBPs in a coronal hole to study their eruptive behavior using data from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory. About one-quarter to one-third of the CBPs in the coronal hole go through one or more minifilament eruption(s) (MFE(s)) throughout their lifetimes. The MFEs occur in temporal association with the <span class="hlt">brightness</span> maxima of CBPs and possibly result from the convergence and cancellation of underlying magnetic dipoles. Two examples of CBPs with MFEs are analyzed in detail, where minifilaments appear as dark features of a cool channel that divide the CBPs along the neutral lines of the dipoles beneath. The MFEs show the typical rising movements of filaments and mass ejections with brightenings at CBPs, similar to large-scale filament eruptions. Via differential emission measure analysis, it is found that CBPs are heated dramatically by their MFEs and the ejected plasmas in the MFEs have average temperatures close to the pre-eruption BP plasmas and electron densities typically near 109 cm-3. These new observational results indicate that CBPs are more complex in dynamical evolution and magnetic structure than previously thought.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000070468','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000070468"><span>Forward Monte Carlo Computations of <span class="hlt">Polarized</span> Microwave Radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Battaglia, A.; Kummerow, C.</p> <p>2000-01-01</p> <p>Microwave radiative transfer computations continue to acquire greater importance as the emphasis in remote sensing shifts towards the understanding of microphysical properties of clouds and with these to better understand the non linear relation between rainfall rates and satellite-observed radiance. A first step toward realistic radiative simulations has been the introduction of techniques capable of treating 3-dimensional geometry being generated by ever more sophisticated cloud resolving models. To date, a series of numerical codes have been developed to treat spherical and randomly oriented axisymmetric particles. Backward and backward-forward Monte Carlo methods are, indeed, efficient in this field. These methods, however, cannot deal properly with oriented particles, which seem to play an important role in <span class="hlt">polarization</span> signatures over stratiform precipitation. Moreover, beyond the <span class="hlt">polarization</span> channel, the next generation of fully polarimetric radiometers challenges us to better understand the behavior of the last two Stokes parameters as well. In order to solve the vector radiative transfer equation, one-dimensional numerical models have been developed, These codes, unfortunately, consider the atmosphere as <span class="hlt">horizontally</span> homogeneous with <span class="hlt">horizontally</span> infinite plane parallel layers. The next development step for microwave radiative transfer codes must be fully <span class="hlt">polarized</span> 3-D methods. Recently a 3-D <span class="hlt">polarized</span> radiative transfer model based on the discrete ordinate method was presented. A forward MC code was developed that treats oriented nonspherical hydrometeors, but only for plane-parallel situations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012LPI....43.2513B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012LPI....43.2513B"><span>CO_2 Frost Halos on the South <span class="hlt">Polar</span> Residual Cap of Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Becerra, P.; Byrne, S.; HiRISE Team</p> <p>2012-03-01</p> <p>We present observational analysis, and a numerical model to explain the formation of <span class="hlt">bright</span> CO_2 frost halos seen by HiRISE on the edges of scarps and "swiss cheese" features in the south <span class="hlt">polar</span> residual cap of Mars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29495806','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29495806"><span>A variable partially <span class="hlt">polarizing</span> beam splitter.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Flórez, Jefferson; Carlson, Nathan J; Nacke, Codey H; Giner, Lambert; Lundeen, Jeff S</p> <p>2018-02-01</p> <p>We present designs for variably <span class="hlt">polarizing</span> beam splitters. These are beam splitters allowing the complete and independent control of the <span class="hlt">horizontal</span> and vertical <span class="hlt">polarization</span> splitting ratios. They have quantum optics and quantum information applications, such as quantum logic gates for quantum computing and non-local measurements for quantum state estimation. At the heart of each design is an interferometer. We experimentally demonstrate one particular implementation, a displaced Sagnac interferometer configuration, that provides an inherent instability to air currents and vibrations. Furthermore, this design does not require any custom-made optics but only common components which can be easily found in an optics laboratory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018RScI...89b3108F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018RScI...89b3108F"><span>A variable partially <span class="hlt">polarizing</span> beam splitter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flórez, Jefferson; Carlson, Nathan J.; Nacke, Codey H.; Giner, Lambert; Lundeen, Jeff S.</p> <p>2018-02-01</p> <p>We present designs for variably <span class="hlt">polarizing</span> beam splitters. These are beam splitters allowing the complete and independent control of the <span class="hlt">horizontal</span> and vertical <span class="hlt">polarization</span> splitting ratios. They have quantum optics and quantum information applications, such as quantum logic gates for quantum computing and non-local measurements for quantum state estimation. At the heart of each design is an interferometer. We experimentally demonstrate one particular implementation, a displaced Sagnac interferometer configuration, that provides an inherent instability to air currents and vibrations. Furthermore, this design does not require any custom-made optics but only common components which can be easily found in an optics laboratory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017A%26A...607A..42S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017A%26A...607A..42S"><span><span class="hlt">Polarized</span> scattered light from self-luminous exoplanets. Three-dimensional scattering radiative transfer with ARTES</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stolker, T.; Min, M.; Stam, D. M.; Mollière, P.; Dominik, C.; Waters, L. B. F. M.</p> <p>2017-11-01</p> <p>Context. Direct imaging has paved the way for atmospheric characterization of young and self-luminous gas giants. Scattering in a <span class="hlt">horizontally</span>-inhomogeneous atmosphere causes the disk-integrated <span class="hlt">polarization</span> of the thermal radiation to be linearly <span class="hlt">polarized</span>, possibly detectable with the newest generation of high-contrast imaging instruments. Aims: We aim to investigate the effect of latitudinal and longitudinal cloud variations, circumplanetary disks, atmospheric oblateness, and cloud particle properties on the integrated degree and direction of <span class="hlt">polarization</span> in the near-infrared. We want to understand how 3D atmospheric asymmetries affect the <span class="hlt">polarization</span> signal in order to assess the potential of infrared polarimetry for direct imaging observations of planetary-mass companions. Methods: We have developed a three-dimensional Monte Carlo radiative transfer code (ARTES) for scattered light simulations in (exo)planetary atmospheres. The code is applicable to calculations of reflected light and thermal radiation in a spherical grid with a parameterized distribution of gas, clouds, hazes, and circumplanetary material. A gray atmosphere approximation is used for the thermal structure. Results: The disk-integrated degree of <span class="hlt">polarization</span> of a <span class="hlt">horizontally</span>-inhomogeneous atmosphere is maximal when the planet is flattened, the optical thickness of the equatorial clouds is large compared to the <span class="hlt">polar</span> clouds, and the clouds are located at high altitude. For a flattened planet, the integrated <span class="hlt">polarization</span> can both increase or decrease with respect to a spherical planet which depends on the <span class="hlt">horizontal</span> distribution and optical thickness of the clouds. The direction of <span class="hlt">polarization</span> can be either parallel or perpendicular to the projected direction of the rotation axis when clouds are zonally distributed. Rayleigh scattering by submicron-sized cloud particles will maximize the polarimetric signal whereas the integrated degree of <span class="hlt">polarization</span> is significantly reduced with micron</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RMxAA..53...37B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RMxAA..53...37B"><span>SNR radio spectral index distribution and its correlation with <span class="hlt">polarization</span>. a case study: the Lupus Loop</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Borka Jovanović, V.; Jovanović, P.; Borka, D.</p> <p>2017-04-01</p> <p>We use radio-continuum all-sky surveys at 1420 and 408 MHz with the aim to investigate properties of the Galactic radio source Lupus Loop. The survey data at 1435 MHz, with the linear <span class="hlt">polarization</span> of the southern sky, are also used. We calculate properties of this supernova remnant: the <span class="hlt">brightness</span> temperature, surface <span class="hlt">brightness</span> and radio spectral index. To determine its borders and to calculate its properties, we use the method we have developed. The non-thermal nature of its radiation is confirmed. The distribution of spectral index over its area is also given. A significant correlation between the radio spectral index distribution and the corresponding <span class="hlt">polarized</span> intensity distribution inside the loop borders is found, indicating that the <span class="hlt">polarization</span> maps could provide us information about the distribution of the interstellar medium, and thus could represent one additional way to search for new Galactic loops.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110009951','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110009951"><span>Surface and Atmospheric Contributions to Passive Microwave <span class="hlt">Brightness</span> Temperatures</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jackson, Gail Skofronick; Johnson, Benjamin T.</p> <p>2010-01-01</p> <p>Physically-based passive microwave precipitation retrieval algorithms require a set of relationships between satellite observed <span class="hlt">brightness</span> temperatures (TB) and the physical state of the underlying atmosphere and surface. These relationships are typically non-linear, such that inversions are ill-posed especially over variable land surfaces. In order to better understand these relationships, this work presents a theoretical analysis using <span class="hlt">brightness</span> temperature weighting functions to quantify the percentage of the TB resulting from absorption/emission/reflection from the surface, absorption/emission/scattering by liquid and frozen hydrometeors in the cloud, the emission from atmospheric water vapor, and other contributors. The results are presented for frequencies from 10 to 874 GHz and for several individual precipitation profiles as well as for three cloud resolving model simulations of falling snow. As expected, low frequency channels (<89 GHz) respond to liquid hydrometeors and the surface, while the higher frequency channels become increasingly sensitive to ice hydrometeors and the water vapor sounding channels react to water vapor in the atmosphere. Low emissivity surfaces (water and snow-covered land) permit energy downwelling from clouds to be reflected at the surface thereby increasing the percentage of the TB resulting from the hydrometeors. The slant path at a 53deg viewing angle increases the hydrometeor contributions relative to nadir viewing channels and show sensitivity to surface <span class="hlt">polarization</span> effects. The TB percentage information presented in this paper answers questions about the relative contributions to the <span class="hlt">brightness</span> temperatures and provides a key piece of information required to develop and improve precipitation retrievals over land surfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19770065847&hterms=EFFECTS+BLACK+CARBON&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEFFECTS%2BOF%2BBLACK%2BCARBON','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19770065847&hterms=EFFECTS+BLACK+CARBON&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEFFECTS%2BOF%2BBLACK%2BCARBON"><span>Measured backscatter and attenuation properties, including <span class="hlt">polarization</span> effects, of various dispersions at 0.9 micron</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kohl, R. H.; Flaherty, M. I.; Partin, R. L.</p> <p>1977-01-01</p> <p>The optical properties of a wide variety of atmospheric dispersions were studied using a 0.9-micron lidar system which included a GaAs laser stack transmitter emitting a <span class="hlt">horizontally</span> <span class="hlt">polarized</span> beam of 4 milliradians vertical divergence and 1.5 milliradians <span class="hlt">horizontal</span> divergence. A principal means for assessing optical properties was the <span class="hlt">polarization</span> ratio, that is, the backscattered radiation power perpendicular to the transmitter beam divided by the backscattered radiation power parallel to the beam <span class="hlt">polarization</span>. The ratio of the backscattered fraction to the attenuation coefficient was also determined. Data on the dispersion properties of black carbon smoke, road dust, fog, fair-weather cumulus clouds, snow and rain were obtained; the adverse effects of sunlight-induced background noise on the readings is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4216005','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4216005"><span>Intermittent Episodes of <span class="hlt">Bright</span> Light Suppress Myopia in the Chicken More than Continuous <span class="hlt">Bright</span> Light</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lan, Weizhong; Feldkaemper, Marita; Schaeffel, Frank</p> <p>2014-01-01</p> <p>Purpose <span class="hlt">Bright</span> light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of <span class="hlt">bright</span> light are the most potent in suppressing deprivation myopia in chickens. Methods Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8) was kept under office-like illuminance (500 lux) at a 10∶14 light∶dark cycle. Episodes of <span class="hlt">bright</span> light (15 000 lux) were super-imposed on this background as follows. Paradigm I: exposure to constant <span class="hlt">bright</span> light for either 1 hour (n = 5), 2 hours (n = 5), 5 hours (n = 4) or 10 hours (n = 4). Paradigm II: exposure to repeated cycles of <span class="hlt">bright</span> light with 50% duty cycle and either 60 minutes (n = 7), 30 minutes (n = 8), 15 minutes (n = 6), 7 minutes (n = 7) or 1 minute (n = 7) periods, provided for 10 hours. Refraction and axial length were measured prior to and immediately after the 5-day experiment. Relative changes were analyzed by paired t-tests, and differences among groups were tested by one-way ANOVA. Results Compared with the reference group, exposure to continuous <span class="hlt">bright</span> light for 1 or 2 hours every day had no significant protective effect against deprivation myopia. Inhibition of myopia became significant after 5 hours of <span class="hlt">bright</span> light exposure but extending the duration to 10 hours did not offer an additional benefit. In comparison, repeated cycles of 1∶1 or 7∶7 minutes of <span class="hlt">bright</span> light enhanced the protective effect against myopia and could fully suppress its development. Conclusions The protective effect of <span class="hlt">bright</span> light depends on the exposure duration and, to the intermittent form, the frequency cycle. Compared to the saturation effect of continuous <span class="hlt">bright</span> light, low frequency cycles of <span class="hlt">bright</span> light (1∶1 min) provided the strongest inhibition effect. However, our quantitative results probably might not be directly translated into humans, but rather need further amendments in clinical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25360635','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25360635"><span>Intermittent episodes of <span class="hlt">bright</span> light suppress myopia in the chicken more than continuous <span class="hlt">bright</span> light.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lan, Weizhong; Feldkaemper, Marita; Schaeffel, Frank</p> <p>2014-01-01</p> <p><span class="hlt">Bright</span> light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of <span class="hlt">bright</span> light are the most potent in suppressing deprivation myopia in chickens. Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8) was kept under office-like illuminance (500 lux) at a 10:14 light:dark cycle. Episodes of <span class="hlt">bright</span> light (15 000 lux) were super-imposed on this background as follows. Paradigm I: exposure to constant <span class="hlt">bright</span> light for either 1 hour (n = 5), 2 hours (n = 5), 5 hours (n = 4) or 10 hours (n = 4). Paradigm II: exposure to repeated cycles of <span class="hlt">bright</span> light with 50% duty cycle and either 60 minutes (n = 7), 30 minutes (n = 8), 15 minutes (n = 6), 7 minutes (n = 7) or 1 minute (n = 7) periods, provided for 10 hours. Refraction and axial length were measured prior to and immediately after the 5-day experiment. Relative changes were analyzed by paired t-tests, and differences among groups were tested by one-way ANOVA. Compared with the reference group, exposure to continuous <span class="hlt">bright</span> light for 1 or 2 hours every day had no significant protective effect against deprivation myopia. Inhibition of myopia became significant after 5 hours of <span class="hlt">bright</span> light exposure but extending the duration to 10 hours did not offer an additional benefit. In comparison, repeated cycles of 1:1 or 7:7 minutes of <span class="hlt">bright</span> light enhanced the protective effect against myopia and could fully suppress its development. The protective effect of <span class="hlt">bright</span> light depends on the exposure duration and, to the intermittent form, the frequency cycle. Compared to the saturation effect of continuous <span class="hlt">bright</span> light, low frequency cycles of <span class="hlt">bright</span> light (1:1 min) provided the strongest inhibition effect. However, our quantitative results probably might not be directly translated into humans, but rather need further amendments in clinical studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26698061','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26698061"><span>Investigation of the <span class="hlt">polarization</span> state of dual APPLE-II undulators.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hand, Matthew; Wang, Hongchang; Dhesi, Sarnjeet S; Sawhney, Kawal</p> <p>2016-01-01</p> <p>The use of an APPLE II undulator is extremely important for providing a high-brilliance X-ray beam with the capability to switch between various photon beam <span class="hlt">polarization</span> states. A high-precision soft X-ray polarimeter has been used to systematically investigate the <span class="hlt">polarization</span> characteristics of the two helical APPLE II undulators installed on beamline I06 at Diamond Light Source. A simple data acquisition and processing procedure has been developed to determine the Stokes <span class="hlt">polarization</span> parameters for light <span class="hlt">polarized</span> at arbitrary linear angles emitted from a single undulator, and for circularly <span class="hlt">polarized</span> light emitted from both undulators in conjunction with a single-period undulator phasing unit. The purity of linear <span class="hlt">polarization</span> is found to deteriorate as the <span class="hlt">polarization</span> angle moves away from the <span class="hlt">horizontal</span> and vertical modes. Importantly, a negative correlation between the degree of circular <span class="hlt">polarization</span> and the photon flux has been found when the phasing unit is used.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1634927','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1634927"><span>Why do red and dark-coloured cars lure aquatic insects? The attraction of water insects to car paintwork explained by reflection–<span class="hlt">polarization</span> signals</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kriska, György; Csabai, Zoltán; Boda, Pál; Malik, Péter; Horváth, Gábor</p> <p>2006-01-01</p> <p>We reveal here the visual ecological reasons for the phenomenon that aquatic insects often land on red, black and dark-coloured cars. Monitoring the numbers of aquatic beetles and bugs attracted to shiny black, white, red and yellow <span class="hlt">horizontal</span> plastic sheets, we found that red and black reflectors are equally highly attractive to water insects, while yellow and white reflectors are unattractive. The reflection–<span class="hlt">polarization</span> patterns of black, white, red and yellow cars were measured in the red, green and blue parts of the spectrum. In the blue and green, the degree of linear <span class="hlt">polarization</span> p of light reflected from red and black cars is high and the direction of <span class="hlt">polarization</span> of light reflected from red and black car roofs, bonnets and boots is nearly <span class="hlt">horizontal</span>. Thus, the <span class="hlt">horizontal</span> surfaces of red and black cars are highly attractive to red-blind polarotactic water insects. The p of light reflected from the <span class="hlt">horizontal</span> surfaces of yellow and white cars is low and its direction of <span class="hlt">polarization</span> is usually not <span class="hlt">horizontal</span>. Consequently, yellow and white cars are unattractive to polarotactic water insects. The visual deception of aquatic insects by cars can be explained solely by the reflection–polarizational characteristics of the car paintwork. PMID:16769639</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19810032372&hterms=MOOS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DMOOS','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19810032372&hterms=MOOS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DMOOS"><span>Observations from earth orbit and variability of the <span class="hlt">polar</span> aurora on Jupiter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Clarke, J. T.; Moos, H. W.; Atreya, S. K.; Lane, A. L.</p> <p>1980-01-01</p> <p>Spatially resolved spectra of Jupiter taken with the International Ultraviolet Explorer satellite show enhanced emissions from the <span class="hlt">polar</span> regions at H L-alpha (1216 A) and in the Lyman and Werner bands of H2 (1175-1650 A). Two types of variability in emission <span class="hlt">brightness</span> have been observed in these aurorae: an increase in the observed emission as the auroral oval rotates with Jupiter's magnetic pole to face toward the earth and a general variation in <span class="hlt">brightness</span> of more than an order of magnitude under nearly identical observing conditions. In addition, the spectral character of these aurorae (determined by the ratio of H L-alpha to H2 <span class="hlt">brightnesses</span>) appears variable, indicating that the depth of penetration of the auroral particles is not constant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7840E..25L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7840E..25L"><span>Study of the model of calibrating differences of <span class="hlt">brightness</span> temperature from geostationary satellite generated by time zone differences</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Weidong; Shan, Xinjian; Qu, Chunyan</p> <p>2010-11-01</p> <p>In comparison with <span class="hlt">polar</span>-orbiting satellites, geostationary satellites have a higher time resolution and wider field of visions, which can cover eleven time zones (an image covers about one third of the Earth's surface). For a geostationary satellite panorama graph at a point of time, the <span class="hlt">brightness</span> temperature of different zones is unable to represent the thermal radiation information of the surface at the same point of time because of the effect of different sun solar radiation. So it is necessary to calibrate <span class="hlt">brightness</span> temperature of different zones with respect to the same point of time. A model of calibrating the differences of the <span class="hlt">brightness</span> temperature of geostationary satellite generated by time zone differences is suggested in this study. A total of 16 curves of four positions in four different stages are given through sample statistics of <span class="hlt">brightness</span> temperature of every 5 days synthetic data which are from four different time zones (time zones 4, 6, 8, and 9). The above four stages span January -March (winter), April-June (spring), July-September (summer), and October-December (autumn). Three kinds of correct situations and correct formulas based on curves changes are able to better eliminate <span class="hlt">brightness</span> temperature rising or dropping caused by time zone differences.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890033162&hterms=bright+hour&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbright%2Bhour','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890033162&hterms=bright+hour&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbright%2Bhour"><span>Coronal <span class="hlt">bright</span> points in microwaves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kundu, M. R.; Nitta, N.</p> <p>1988-01-01</p> <p>An excellent map of the quiet sun showing coronal <span class="hlt">bright</span> points at 20-cm wavelength was produced using the VLA on February 13, 1987. The locations of <span class="hlt">bright</span> points (BPs) were studied relative to features on the photospheric magnetogram and Ca K spectroheliogram. Most <span class="hlt">bright</span> points appearing in the full 5-hour synthesized map are associated with small bipolar structures on the photospheric magnetogram; and the brightest part of a BP tends to lie on the boundary of a supergranulation network. The <span class="hlt">bright</span> points exhibit rapid variations in intensity superposed on an apparently slow variation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010A%26A...519A..58T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010A%26A...519A..58T"><span><span class="hlt">Horizontal</span> supergranule-scale motions inferred from TRACE ultraviolet observations of the chromosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tian, H.; Potts, H. E.; Marsch, E.; Attie, R.; He, J.-S.</p> <p>2010-09-01</p> <p>Aims: We study <span class="hlt">horizontal</span> supergranule-scale motions revealed by TRACE observation of the chromospheric emission, and investigate the coupling between the chromosphere and the underlying photosphere. Methods: A highly efficient feature-tracking technique called balltracking has been applied for the first time to the image sequences obtained by TRACE (transition region and coronal explorer) in the passband of white light and the three ultraviolet passbands centered at 1700 Å, 1600 Å, and 1550 Å. The resulting velocity fields have been spatially smoothed and temporally averaged in order to reveal <span class="hlt">horizontal</span> supergranule-scale motions that may exist at the emission heights of these passbands. Results: We find indeed a high correlation between the <span class="hlt">horizontal</span> velocities derived in the white-light and ultraviolet passbands. The <span class="hlt">horizontal</span> velocities derived from the chromospheric and photospheric emission are comparable in magnitude. Conclusions: The <span class="hlt">horizontal</span> motions derived in the UV passbands might indicate the existence of a supergranule-scale magneto-convection in the chromosphere, which may shed new light on the study of mass and energy supply to the corona and solar wind at the height of the chromosphere. However, it is also possible that the apparent motions reflect the chromospheric <span class="hlt">brightness</span> evolution as produced by acoustic shocks which might be modulated by the photospheric granular motions in their excitation process, or advected partly by the supergranule-scale flow towards the network while propagating upward from the photosphere. To reach a firm conclusion, it is necessary to investigate the role of granular motions in the excitation of shocks through numerical modeling, and future high-cadence chromospheric magnetograms must be scrutinized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97t5413C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97t5413C"><span><span class="hlt">Polarized</span> excitons and optical activity in single-wall carbon nanotubes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chang, Yao-Wen; Jin, Bih-Yaw</p> <p>2018-05-01</p> <p>The <span class="hlt">polarized</span> excitons and optical activity of single-wall carbon nanotubes (SWNTs) are studied theoretically by π -electron Hamiltonian and helical-rotational symmetry. By taking advantage of the symmetrization, the single-particle energy and properties of a SWNT are characterized with the corresponding helical band structure. The dipole-moment matrix elements, magnetic-moment matrix elements, and the selection rules can also be derived. Based on different selection rules, the optical transitions can be assigned as the parallel-<span class="hlt">polarized</span>, left-handed circularly-<span class="hlt">polarized</span>, and right-handed circularly-<span class="hlt">polarized</span> transitions, where the combination of the last two gives the cross-<span class="hlt">polarized</span> transition. The absorption and circular dichroism (CD) spectra are simulated by exciton calculation. The calculated results are well comparable with the reported measurements. Built on the foundation, magnetic-field effects on the <span class="hlt">polarized</span> excitons and optical activity of SWNTs are studied. Dark-<span class="hlt">bright</span> exciton splitting and interband Faraday effect in the CD spectrum of SWNTs under an axial magnetic field are predicted. The Faraday rotation dispersion can be analyzed according to the selection rules of circular <span class="hlt">polarizations</span> and the helical band structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA12525.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA12525.html"><span>Faint Ring, <span class="hlt">Bright</span> Arc</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2010-01-12</p> <p>In this image taken by NASA Cassini spacecraft, the <span class="hlt">bright</span> arc in Saturn faint G ring contains a little something special. Although it cant be seen here, the tiny moonlet Aegaeon orbits within the <span class="hlt">bright</span> arc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19699746','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19699746"><span>Degrees of <span class="hlt">polarization</span> of reflected light eliciting polarotaxis in dragonflies (Odonata), mayflies (Ephemeroptera) and tabanid flies (Tabanidae).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kriska, György; Bernáth, Balázs; Farkas, Róbert; Horváth, Gábor</p> <p>2009-12-01</p> <p>With few exceptions insects whose larvae develop in freshwater possess positive polarotaxis, i.e., are attracted to sources of <span class="hlt">horizontally</span> <span class="hlt">polarized</span> light, because they detect water by means of the <span class="hlt">horizontal</span> <span class="hlt">polarization</span> of light reflected from the water surface. These insects can be deceived by artificial surfaces (e.g. oil lakes, asphalt roads, black plastic sheets, dark-coloured cars, black gravestones, dark glass surfaces, solar panels) reflecting highly and <span class="hlt">horizontally</span> <span class="hlt">polarized</span> light. Apart from the surface characteristics, the extent of such a '<span class="hlt">polarized</span> light pollution' depends on the illumination conditions, direction of view, and the threshold p* of <span class="hlt">polarization</span> sensitivity of a given aquatic insect species. p* means the minimum degree of linear <span class="hlt">polarization</span> p of reflected light that can elicit positive polarotaxis from a given insect species. Earlier there were no quantitative data on p* in aquatic insects. The aim of this work is to provide such data. Using imaging polarimetry in the red, green and blue parts of the spectrum, in multiple-choice field experiments we measured the threshold p* of ventral <span class="hlt">polarization</span> sensitivity in mayflies, dragonflies and tabanid flies, the positive polarotaxis of which has been shown earlier. In the blue (450nm) spectral range, for example, we obtained the following thresholds: dragonflies: Enallagma cyathigerum (0%<p*< or =17%), Ischnura elegans (17%< or =p*< or =24%). Mayflies: Baetis rhodani (32%< or =p*< or =55%), Ephemera danica, Epeorus silvicola, Rhithrogena semicolorata (55%< or =p*< or =92%). Tabanids: Tabanus bovinus, Tabanus tergestinus (32%< or =p*< or =55%), Tabanus maculicornis (55%< or =p*< or =92%).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28943677','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28943677"><span>Imaging Mercury's <span class="hlt">Polar</span> Deposits during MESSENGER's Low-altitude Campaign.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chabot, Nancy L; Ernst, Carolyn M; Paige, David A; Nair, Hari; Denevi, Brett W; Blewett, David T; Murchie, Scott L; Deutsch, Ariel N; Head, James W; Solomon, Sean C</p> <p>2016-09-28</p> <p>Images obtained during MESSENGER's low-altitude campaign in the final year of the mission provide the highest-spatial-resolution views of Mercury's <span class="hlt">polar</span> deposits. Images for distinct areas of permanent shadow within 35 north <span class="hlt">polar</span> craters were successfully captured during the campaign. All of these regions of permanent shadow were found to have low-reflectance surfaces with well-defined boundaries. Additionally, <span class="hlt">brightness</span> variations across the deposits correlate with variations in the biannual maximum surface temperature across the permanently shadowed regions, supporting the conclusion that multiple volatile organic compounds are contained in Mercury's <span class="hlt">polar</span> deposits, in addition to water ice. A recent large impact event or ongoing bombardment by micrometeoroids could deliver water as well as many volatile organic compounds to Mercury. Either scenario is consistent with the distinctive reflectance properties and well-defined boundaries of Mercury's <span class="hlt">polar</span> deposits and the presence of volatiles in all available cold traps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70187697','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70187697"><span>Ethylene glycol (antifreeze) poisoning in a free-ranging <span class="hlt">polar</span> bear</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Amstrup, Steven C.; Gardner, Craig L.; Myers, Kevin C.; Oehme, Frederick W.</p> <p>1989-01-01</p> <p>The <span class="hlt">bright</span>, fluorescent pink-colored remains of a <span class="hlt">polar</span> bear were found on an Alaskan island with the gravel and snow adjacent to the bear colored <span class="hlt">bright</span> purple. Traces of fox urine and feces found nearby were also pink. The punk and purple colors were due to rhodamine B, and ethylene glycol (EG) was present in the soil under the carcass. Evidence is given to suggest the bear consumed a mixture of rhodamine B and EG commonly used to mark roads and runways during snow and ice periods. Such wildlife losses could be prevented by substituting propylene glycol for the EG in such mixtures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007ApJ...668L..59V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007ApJ...668L..59V"><span>CPD -20 1123 (Albus 1) Is a <span class="hlt">Bright</span> He-B Subdwarf</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vennes, Stéphane; Kawka, Adéla; Smith, J. Allyn</p> <p>2007-10-01</p> <p>Based on photometric and astrometric data it has been proposed that Albus 1 (also known as CPD -20 1123) might be a hot white dwarf similar to G191-B2B or, alternatively, a hot subdwarf. We obtained a series of optical spectra showing that CPD -20 1123 is a <span class="hlt">bright</span> He-B subdwarf. We analyzed the H I Balmer and He I line spectra and measured Teff = 19,800 +/- 400 K, logg=4.55+/-0.10, and logN(He)/N(H)=0.15+/-0.15. This peculiar object belongs to a family of evolved helium-rich stars that may be the products of double-degenerate mergers, or, alternatively, the products of post <span class="hlt">horizontal</span>- or giant-branch evolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840013224','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840013224"><span><span class="hlt">Polarization</span> radiation in the planetary atmosphere delimited by a heterogeneous diffusely reflecting surface</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Strelkov, S. A.; Sushkevich, T. A.</p> <p>1983-01-01</p> <p>Spatial frequency characteristics (SFC) and the scattering functions were studied in the two cases of a uniform <span class="hlt">horizontal</span> layer with absolutely black bottom, and an isolated layer. The mathematical model for these examples describes the <span class="hlt">horizontal</span> heterogeneities in a light field with regard to radiation <span class="hlt">polarization</span> in a three dimensional planar atmosphere, delimited by a heterogeneous surface with diffuse reflection. The perturbation method was used to obtain vector transfer equations which correspond to the linear and nonlinear systems of <span class="hlt">polarization</span> radiation transfer. The boundary value tasks for the vector transfer equation that is a parametric set and one dimensional are satisfied by the SFC of the nonlinear system, and are expressed through the SFC of linear approximation. As a consequence of the developed theory, formulas were obtained for analytical calculation of albedo in solving the task of dissemination of <span class="hlt">polarization</span> radiation in the planetary atmosphere with uniform Lambert bottom.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22370183-coronal-bright-points-associated-minifilament-eruptions','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22370183-coronal-bright-points-associated-minifilament-eruptions"><span>Coronal <span class="hlt">bright</span> points associated with minifilament eruptions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Hong, Junchao; Jiang, Yunchun; Yang, Jiayan</p> <p>2014-12-01</p> <p>Coronal <span class="hlt">bright</span> points (CBPs) are small-scale, long-lived coronal brightenings that always correspond to photospheric network magnetic features of opposite <span class="hlt">polarity</span>. In this paper, we subjectively adopt 30 CBPs in a coronal hole to study their eruptive behavior using data from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory. About one-quarter to one-third of the CBPs in the coronal hole go through one or more minifilament eruption(s) (MFE(s)) throughout their lifetimes. The MFEs occur in temporal association with the <span class="hlt">brightness</span> maxima of CBPs and possibly result from the convergence and cancellationmore » of underlying magnetic dipoles. Two examples of CBPs with MFEs are analyzed in detail, where minifilaments appear as dark features of a cool channel that divide the CBPs along the neutral lines of the dipoles beneath. The MFEs show the typical rising movements of filaments and mass ejections with brightenings at CBPs, similar to large-scale filament eruptions. Via differential emission measure analysis, it is found that CBPs are heated dramatically by their MFEs and the ejected plasmas in the MFEs have average temperatures close to the pre-eruption BP plasmas and electron densities typically near 10{sup 9} cm{sup –3}. These new observational results indicate that CBPs are more complex in dynamical evolution and magnetic structure than previously thought.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8873E..0IT','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8873E..0IT"><span>Using linear <span class="hlt">polarization</span> for LWIR hyperspectral sensing of liquid contaminants</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thériault, Jean-Marc; Fortin, Gilles; Lacasse, Paul; Bouffard, François; Lavoie, Hugo</p> <p>2013-09-01</p> <p>We report and analyze recent results obtained with the MoDDIFS sensor (Multi-option Differential Detection and Imaging Fourier Spectrometer) for the passive <span class="hlt">polarization</span> sensing of liquid contaminants in the long wave infrared (LWIR). Field measurements of <span class="hlt">polarized</span> spectral radiance done on ethylene glycol and SF96 probed at distances of 6.5 and 450 meters, respectively, have been used to develop and test a GLRT-type detection algorithm adapted for liquid contaminants. The GLRT detection results serve to establish the potential and advantage of probing the vertical and <span class="hlt">horizontal</span> linear hyperspectral <span class="hlt">polarization</span> components for improving liquid contaminants detection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21716433','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21716433"><span>Femtosecond laser fabrication of birefringent directional couplers as <span class="hlt">polarization</span> beam splitters in fused silica.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fernandes, Luís A; Grenier, Jason R; Herman, Peter R; Aitchison, J Stewart; Marques, Paulo V S</p> <p>2011-06-20</p> <p>Integrated <span class="hlt">polarization</span> beam splitters based on birefringent directional couplers are demonstrated. The devices are fabricated in bulk fused silica glass by femtosecond laser writing (300 fs, 150 nJ at 500 kHz, 522 nm). The birefringence was measured from the spectral splitting of the Bragg grating resonances associated with the vertically and <span class="hlt">horizontally</span> <span class="hlt">polarized</span> modes. <span class="hlt">Polarization</span> splitting directional couplers were designed and demonstrated with 0.5 dB/cm propagation losses and -19 dB and -24 dB extinction ratios for the <span class="hlt">polarization</span> splitting.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140007394','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140007394"><span>Cassini Returns to Saturn's Poles: Seasonal Change in the <span class="hlt">Polar</span> Vortices</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fletcher, Leigh N.; Orton, G. S.; Irwin, P. G. J.; Sinclair, J. A.; Hesman, B. E.; Hurley, J.; Bjoraker, G. L.; Simon-Miller, A. A.</p> <p>2013-01-01</p> <p>High inclination orbits during Cassini's solstice mission (2012) are providing us with our first observations of Saturn's high latitudes since the prime mission (2007). Since that time, the northern spring pole has emerged into sunlight and the southern autumn pole has disappeared into winter darkness, allowing us to study the seasonal changes occurring within the <span class="hlt">polar</span> vortices in response to these dramatic insolation changes. Observations from the Cassini Composite Infrared Spectrometer] have revealed (i) the continued presence of small, cyclonic <span class="hlt">polar</span> hotspots at both spring and autumn poles; and (ii) the emergence of an infrared-<span class="hlt">bright</span> <span class="hlt">polar</span> vortex at the north pole, consistent with the historical record of Saturn observations from the 1980s (previous northern spring).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AGUFM.C11F..03M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AGUFM.C11F..03M"><span>Effect of Different Tree canopies on the <span class="hlt">Brightness</span> Temperature of Snowpack</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mousavi, S.; De Roo, R. D.; Brucker, L.</p> <p>2017-12-01</p> <p>Snow stores the water we drink and is essential to grow food that we eat. But changes in snow quantities such as snow water equivalent (SWE) are underway and have serious consequences. So, effective management of the freshwater reservoir requires to monitor frequently (weekly or better) the spatial distribution of SWE and snowpack wetness. Both microwave radar and radiometer systems have long been considered as relevant remote sensing tools in retrieving globally snow physical parameters of interest thanks to their all-weather operation capability. However, their observations are sensitive to the presence of tree canopies, which in turns impacts SWE estimation. To address this long-lasting challenge, we parked a truck-mounted microwave radiometer system for an entire winter in a rare area where it exists different tree types in the different cardinal directions. We used dual-<span class="hlt">polarization</span> microwave radiometers at three different frequencies (1.4, 19, and 37 GHz), mounted on a boom truck to observe continuously the snowpack surrounding the truck. Observations were recorded at different incidence angles. These measurements have been collected in Grand Mesa National Forest, Colorado as part of the NASA SnowEx 2016-17. In this presentation, the effect of Engelmann Spruce and Aspen trees on the measured <span class="hlt">brightness</span> temperature of snow is discussed. It is shown that Engelmann Spruce trees increases the <span class="hlt">brightness</span> temperature of the snowpack more than Aspen trees do. Moreover, the elevation angular dependence of the measured <span class="hlt">brightness</span> temperatures of snowpack with and without tree canopies is investigated in the context of SWE retrievals. A time-lapse camera was monitoring a snow post installed in the sensors' field of view to characterize the <span class="hlt">brightness</span> temperature change as snow depth evolved. Also, our study takes advantage of the snowpit measurements that were collected near the radiometers' field of view.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ApJ...642L.115H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ApJ...642L.115H"><span>Intrinsic <span class="hlt">Brightness</span> Temperatures of AGN Jets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Homan, D. C.; Kovalev, Y. Y.; Lister, M. L.; Ros, E.; Kellermann, K. I.; Cohen, M. H.; Vermeulen, R. C.; Zensus, J. A.; Kadler, M.</p> <p>2006-05-01</p> <p>We present a new method for studying the intrinsic <span class="hlt">brightness</span> temperatures of the parsec-scale jet cores of active galactic nuclei (AGNs). Our method uses observed superluminal motions and observed <span class="hlt">brightness</span> temperatures for a large sample of AGNs to constrain the characteristic intrinsic <span class="hlt">brightness</span> temperature of the sample as a whole. To study changes in intrinsic <span class="hlt">brightness</span> temperature, we assume that the Doppler factors of individual jets are constant in time, as justified by their relatively small changes in observed flux density. We find that in their median-low <span class="hlt">brightness</span> temperature state, the sources in our sample have a narrow range of intrinsic <span class="hlt">brightness</span> temperatures centered on a characteristic temperature, Tint~=3×1010 K, which is close to the value expected for equipartition, when the energy in the radiating particles equals the energy stored in the magnetic fields. However, in their maximum <span class="hlt">brightness</span> state, we find that sources in our sample have a characteristic intrinsic <span class="hlt">brightness</span> temperature greater than 2×1011 K, which is well in excess of the equipartition temperature. In this state, we estimate that the energy in radiating particles exceeds the energy in the magnetic field by a factor of ~105. We suggest that the excess of particle energy when sources are in their maximum <span class="hlt">brightness</span> state is due to injection or acceleration of particles at the base of the jet. Our results suggest that the common method of estimating jet Doppler factors by using a single measurement of observed <span class="hlt">brightness</span> temperature, the assumption of equipartition, or both may lead to large scatter or systematic errors in the derived values.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9452E..0AS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9452E..0AS"><span>Simulation of a <span class="hlt">polarized</span> laser beam reflected at the sea surface: modeling and validation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schwenger, Frédéric</p> <p>2015-05-01</p> <p> meteorological data) was analyzed. An infrared laser, with or without a mounted <span class="hlt">polarizer</span>, produced laser beam reflection at the water surface and images were recorded by a camera equipped with a <span class="hlt">polarizer</span> with <span class="hlt">horizontal</span> or vertical alignment. The validation is done by numerical comparison of measured total laser power extracted from recorded images with the corresponding simulation results. The results of the comparison are presented for different incident (zenith/azimuth) angles of the laser beam and different alignment for the laser <span class="hlt">polarizers</span> (vertical/<span class="hlt">horizontal</span>/without) and the camera (vertical/<span class="hlt">horizontal</span>).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PApGe.174.1399C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PApGe.174.1399C"><span>Determining the Depth of Infinite <span class="hlt">Horizontal</span> Cylindrical Sources from Spontaneous <span class="hlt">Polarization</span> Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cooper, G. R. J.; Stettler, E. H.</p> <p>2017-03-01</p> <p>Previously published semi-automatic interpretation methods that use ratios of analytic signal amplitudes of orders that differ by one to determine the distance to potential field sources are shown also to apply to self-potential (S.P.) data when the source is a <span class="hlt">horizontal</span> cylinder. Local minima of the distance (when it becomes closest to zero) give the source depth. The method was applied to an S.P. anomaly from the Bourkes Luck potholes district in Mpumalanga Province, South Africa, and gave results that were confirmed by drilling.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1332904-polarization-control-ray-free-electron-laser','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1332904-polarization-control-ray-free-electron-laser"><span><span class="hlt">Polarization</span> control in an X-ray free-electron laser</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Lutman, Alberto A.; MacArthur, James P.; Ilchen, Markus; ...</p> <p>2016-05-09</p> <p>X-ray free-electron lasers are unique sources of high-<span class="hlt">brightness</span> coherent radiation. However, existing devices supply only linearly <span class="hlt">polarized</span> light, precluding studies of chiral dynamics. A device called the Delta undulator has been installed at the Linac Coherent Light Source (LCLS) to provide tunable <span class="hlt">polarization</span>. With a reverse tapered planar undulator line to pre-microbunch the beam and the novel technique of beam diverting, hundreds of microjoules of circularly <span class="hlt">polarized</span> X-ray pulses are produced at 500–1,200 eV. These X-ray pulses are tens of femtoseconds long, have a degree of circular <span class="hlt">polarization</span> of 0.98 –0.04 +0.02 at 707 eV and may be scanned inmore » energy. We also present a new two-colour X-ray pump–X-ray probe operating mode for the LCLS. As a result, energy differences of ΔE/E = 2.4% are supported, and the second pulse can be adjusted to any elliptical <span class="hlt">polarization</span>. In this mode, the pointing, timing, intensity and wavelength of the two pulses can be modified.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...847...37C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...847...37C"><span>Do Low Surface <span class="hlt">Brightness</span> Galaxies Host Stellar Bars?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cervantes Sodi, Bernardo; Sánchez García, Osbaldo</p> <p>2017-09-01</p> <p>With the aim of assessing if low surface <span class="hlt">brightness</span> galaxies host stellar bars and by studying the dependence of the occurrence of bars as a function of surface <span class="hlt">brightness</span>, we use the Galaxy Zoo 2 data set to construct a large volume-limited sample of galaxies and then segregate these galaxies as having low or high surface <span class="hlt">brightness</span> in terms of their central surface <span class="hlt">brightness</span>. We find that the fraction of low surface <span class="hlt">brightness</span> galaxies hosting strong bars is systematically lower than that found for high surface <span class="hlt">brightness</span> galaxies. The dependence of the bar fraction on the central surface <span class="hlt">brightness</span> is mostly driven by a correlation of the surface <span class="hlt">brightness</span> with the spin and the gas richness of the galaxies, showing only a minor dependence on the surface <span class="hlt">brightness</span>. We also find that the length of the bars is strongly dependent on the surface <span class="hlt">brightness</span>, and although some of this dependence is attributed to the gas content, even at a fixed gas-to-stellar mass ratio, high surface <span class="hlt">brightness</span> galaxies host longer bars than their low surface <span class="hlt">brightness</span> counterparts, which we attribute to an anticorrelation of the surface <span class="hlt">brightness</span> with the spin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22679825-do-low-surface-brightness-galaxies-host-stellar-bars','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22679825-do-low-surface-brightness-galaxies-host-stellar-bars"><span>Do Low Surface <span class="hlt">Brightness</span> Galaxies Host Stellar Bars?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cervantes Sodi, Bernardo; Sánchez García, Osbaldo, E-mail: b.cervantes@irya.unam.mx, E-mail: o.sanchez@irya.unam.mx</p> <p></p> <p>With the aim of assessing if low surface <span class="hlt">brightness</span> galaxies host stellar bars and by studying the dependence of the occurrence of bars as a function of surface <span class="hlt">brightness</span>, we use the Galaxy Zoo 2 data set to construct a large volume-limited sample of galaxies and then segregate these galaxies as having low or high surface <span class="hlt">brightness</span> in terms of their central surface <span class="hlt">brightness</span>. We find that the fraction of low surface <span class="hlt">brightness</span> galaxies hosting strong bars is systematically lower than that found for high surface <span class="hlt">brightness</span> galaxies. The dependence of the bar fraction on the central surface <span class="hlt">brightness</span> ismore » mostly driven by a correlation of the surface <span class="hlt">brightness</span> with the spin and the gas richness of the galaxies, showing only a minor dependence on the surface <span class="hlt">brightness</span>. We also find that the length of the bars is strongly dependent on the surface <span class="hlt">brightness</span>, and although some of this dependence is attributed to the gas content, even at a fixed gas-to-stellar mass ratio, high surface <span class="hlt">brightness</span> galaxies host longer bars than their low surface <span class="hlt">brightness</span> counterparts, which we attribute to an anticorrelation of the surface <span class="hlt">brightness</span> with the spin.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870060839&hterms=Resonance+magnetic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DResonance%2Bmagnetic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870060839&hterms=Resonance+magnetic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DResonance%2Bmagnetic"><span>Magnetic elliptical <span class="hlt">polarization</span> of Schumann resonances</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sentman, D. D.</p> <p>1987-01-01</p> <p>Measurements of orthogonal, <span class="hlt">horizontal</span> components of the magnetic field in the ELF range obtained during September 1985 show that the Schumann resonance eigenfrequencies determined separately for the north-south and east-west magnetic components differ by as much as 0.5 Hz, suggesting that the underlying magnetic signal is not linearly <span class="hlt">polarized</span> at such times. The high degree of magnetic ellipticity found suggests that the side multiplets of the Schumann resonances corresponding to azimuthally inhomogeneous normal modes are strongly excited in the highly asymmetric earth-ionosphere cavity. The dominant sense of <span class="hlt">polarization</span> over the measurement passband is found to be right-handed during local daylight hours, and to be left-handed during local nighttime hours.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA21914.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA21914.html"><span>Map of Ceres' <span class="hlt">Bright</span> Spots</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2017-12-12</p> <p>This map from NASA's Dawn mission shows locations of <span class="hlt">bright</span> material on dwarf planet Ceres. There are more than 300 <span class="hlt">bright</span> areas, called "faculae," on Ceres. Scientists have divided them into four categories: <span class="hlt">bright</span> areas on the floors of crater (red), on the rims or walls of craters (green), in the ejecta blankets of craters (blue), and on the flanks of the mountain Ahuna Mons (yellow). https://photojournal.jpl.nasa.gov/catalog/PIA21914</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AstBu..73..241A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AstBu..73..241A"><span>Observations of Near-Earth Asteroids in <span class="hlt">Polarized</span> Light</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Afanasiev, V. L.; Ipatov, A. V.</p> <p>2018-04-01</p> <p>We report the results of position, photometric, and polarimetric observations of two near-Earth asteroids made with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. 1.2-hour measurements of the photometric variations of the asteroid 2009 DL46 made onMarch 8, 2016 (approximately 20m at a distance of about 0.23 AU from the Earth) showed a 0.m2-amplitude flash with a duration of about 20 minutes. During this time the <span class="hlt">polarization</span> degree increased from the average level of 2-3% to 14%. The angle of the <span class="hlt">polarization</span> plane and the phase angle were equal to 113° ± 1° and 43°, respectively. Our result indicates that the surface of the rotating asteroid (the rotation period of about 2.5 hours) must be non-uniformly rough. Observations of another asteroid—1994 UG—whose <span class="hlt">brightness</span> was of about 17m and which was located at a geocentric distance of 0.077 AU, were carried out during the night of March 6/7, 2016 in two modes: photometric and spectropolarimetric. According to the results of photometric observations in Johnson's B-, V-, and R-band filters, over one hour the <span class="hlt">brightness</span> of the asteroid remained unchanged within the measurement errors (about 0.m02). Spectropolarimetric observations in the 420-800 nm wavelength interval showed the <span class="hlt">polarization</span> degree to decrease from 8% in the blue part of the spectrum to 2% in the red part with the phase angle equal to 44°, which is typical for S-type near-Earth asteroids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009913','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009913"><span>Dark Material at the Surface of <span class="hlt">Polar</span> Crater Deposits on Mercury</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Neumann, Gregory A.; Cavanaugh, John F.; Sun, Xiaoli; Mazarico, Erwan; Smith, David E.; Zuber, Maria T.; Solomon, Sean C.; Paige, Daid A.</p> <p>2012-01-01</p> <p>Earth-based radar measurements [1-3] have yielded images of radar-<span class="hlt">bright</span> material at the poles of Mercury postulated to be near-surface water ice residing in cold traps on the permanently shadowed floors of <span class="hlt">polar</span> impact craters. The Mercury Laser Altimeter (MLA) on board the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft has now mapped much of the north <span class="hlt">polar</span> region of Mercury [4] (Fig. 1). Radar-<span class="hlt">bright</span> zones lie within <span class="hlt">polar</span> craters or along poleward-facing scarps lying mainly in shadow. Calculations of illumination with respect to solid-body motion [5] show that at least 0.5% of the surface area north of 75deg N lies in permanent shadow, and that most such permanently shadowed regions (PSRs) coincide with radar-<span class="hlt">bright</span> regions. MLA transmits a 1064-nm-wavelength laser pulse at 8 Hz, timing the leading and trailing edges of the return pulse. MLA can in some cases infer energy and thereby surface reflectance at the laser wavelength from the returned pulses. Surficial exposures of water ice would be optically brighter than the surroundings, but persistent surface water ice would require temperatures over all seasons to remain extremely low (<110 K). Thermal models [6,7] incorporating direct and scattered radiation, Mercury s eccentric orbit, 3:2 spin-orbit resonance, and near-zero obliquity generally do not support such conditions in all permanently shadowed craters but suggest that water ice buried near the surface (<0.5 m depth) could survive for > 1 Gy. We describe measurements of reflectivity derived from MLA pulse returns. These reflectivity data show that surface materials in the shadowed regions are darker than their surroundings, enough to strongly attenuate or extinguish laser returns. Such measurements appear to rule out widespread surface exposures of water ice. We consider explanations for the apparent low reflectivity of these regions involving other types of volatile deposit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23122008G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23122008G"><span>Physical Conditions in the Solar Corona Derived from the Total Solar Eclipse Observations obtained on 2017 August 21 Using a <span class="hlt">Polarization</span> Camera</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gopalswamy, N.; Yashiro, Seiji; Reginald, Nelson; Thakur, Neeharika; Thompson, Barbara J.; Gong, Qian</p> <p>2018-01-01</p> <p>We present preliminary results obtained by observing the solar corona during the 2017 August 21 total solar eclipse using a <span class="hlt">polarization</span> camera mounted on an eight-inch Schmidt-Cassegrain telescope. The observations were made from Madras Oregon during 17:19 to 17:21 UT. Total and <span class="hlt">polarized</span> <span class="hlt">brightness</span> images were obtained at four wavelengths (385, 398.5, 410, and 423 nm). The <span class="hlt">polarization</span> camera had a <span class="hlt">polarization</span> mask mounted on a 2048x2048 pixel CCD with a pixel size of 7.4 microns. The resulting images had a size of 975x975 pixels because four neighboring pixels were summed to yield the <span class="hlt">polarization</span> and total <span class="hlt">brightness</span> images. The ratio of 410 and 385 nm images is a measure of the coronal temperature, while that at 423 and 398.5 nm images is a measure of the coronal flow speed. We compared the temperature map from the eclipse observations with that obtained from the Solar Dynamics Observatory’s Atmospheric Imaging Assembly images at six EUV wavelengths, yielding consistent temperature information of the corona.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002KosNT...8a..96P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002KosNT...8a..96P"><span><span class="hlt">Polarity</span> of Spore Germination in Funaria hygrometrica Hedw.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pundyak, O. I.; Demkiv, O. T.; Khorkavtsiv, O. Ya; Bagrii, B. B.</p> <p></p> <p>It is shown that in darkness the spores of moss Funaria hygrometrica Hedw. germinated <span class="hlt">polarly</span> under the influence of gravity. At the beginning the rhizoids appeared. They grew downwards. Then future chloronematical stolons started to form a germination spore. Usually, they grew upwards. Clinorotation or <span class="hlt">horizontal</span> placing of Petry dishes could discoordinate such a gravisensitivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22391965-coherence-spin-polarized-electron-beam-emitted-from-semiconductor-photocathode-transmission-electron-microscope','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22391965-coherence-spin-polarized-electron-beam-emitted-from-semiconductor-photocathode-transmission-electron-microscope"><span>Coherence of a spin-<span class="hlt">polarized</span> electron beam emitted from a semiconductor photocathode in a transmission electron microscope</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kuwahara, Makoto, E-mail: kuwahara@esi.nagoya-u.ac.jp; Saitoh, Koh; Tanaka, Nobuo</p> <p>2014-11-10</p> <p>The <span class="hlt">brightness</span> and interference fringes of a spin-<span class="hlt">polarized</span> electron beam extracted from a semiconductor photocathode excited by laser irradiation are directly measured via its use in a transmission electron microscope. The <span class="hlt">brightness</span> was 3.8 × 10{sup 7 }A cm{sup −2 }sr{sup −1} for a 30-keV beam energy with the <span class="hlt">polarization</span> of 82%, which corresponds to 3.1 × 10{sup 8 }A cm{sup −2 }sr{sup −1} for a 200-keV beam energy. The resulting electron beam exhibited a long coherence length at the specimen position due to the high parallelism of (1.7 ± 0.3) × 10{sup −5 }rad, which generated interference fringes representative of a first-order correlation using an electron biprism. The beam also had amore » high degeneracy of electron wavepacket of 4 × 10{sup −6}. Due to the high <span class="hlt">polarization</span>, the high degeneracy and the long coherence length, the spin-<span class="hlt">polarized</span> electron beam can enhance the antibunching effect.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005ACP.....5..547K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005ACP.....5..547K"><span>Climatological features of stratospheric streamers in the FUB-CMAM with increased <span class="hlt">horizontal</span> resolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krüger, K.; Langematz, U.; Grenfell, J. L.; Labitzke, K.</p> <p>2005-01-01</p> <p>The purpose of this study is to investigate <span class="hlt">horizontal</span> transport processes in the winter stratosphere using data with a resolution relevant for chemistry and climate modeling. For this reason the Freie Universität Berlin Climate Middle Atmosphere Model (FUB-CMAM) with its model top at 83 km altitude, increased <span class="hlt">horizontal</span> resolution T42 and the semi-Lagrangian transport scheme for advecting passive tracers is used. <P style="line-height: 20px;"> A new approach of this paper is the classification of specific transport phenomena within the stratosphere into tropical-subtropical streamers (e.g. Offermann et al., 1999) and <span class="hlt">polar</span> vortex extrusions hereafter called <span class="hlt">polar</span> vortex streamers. To investigate the role played by these large-scale structures on the inter-annual and seasonal variability of transport processes in northern mid-latitudes, the global occurrence of such streamers was calculated based on a 10-year model climatology, concentrating on the existence of the Arctic <span class="hlt">polar</span> vortex. For the identification and counting of streamers, the new method of zonal anomaly was chosen. The analysis of the months October-May yielded a maximum occurrence of tropical-subtropical streamers during Arctic winter and spring in the middle and upper stratosphere. Synoptic maps revealed highest intensities in the subtropics over East Asia with a secondary maximum over the Atlantic in the northern hemisphere. Furthermore, tropical-subtropical streamers exhibited a higher occurrence than <span class="hlt">polar</span> vortex streamers, indicating that the subtropical barrier is more permeable than the <span class="hlt">polar</span> vortex barrier (edge) in the model, which is in good correspondence with observations (e.g. Plumb, 2002; Neu et al., 2003). Interesting for the total ozone decrease in mid-latitudes is the consideration of the lower stratosphere for tropical-subtropical streamers and the stratosphere above ~20 km altitude for <span class="hlt">polar</span> vortex streamers, where strongest ozone depletion is observed at <span class="hlt">polar</span> latitudes (WMO, 2003</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA18300.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA18300.html"><span>Little <span class="hlt">Bright</span> Spot</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2015-01-12</p> <p>A <span class="hlt">bright</span> spot can be seen on the left side of Rhea in this image. The spot is the crater Inktomi, named for a Lakota spider spirit. Inktomi is believed to be the youngest feature on Rhea (949 miles or 1527 kilometers across). The relative youth of the feature is evident by its <span class="hlt">brightness</span>. Material that is newly excavated from below the moon's surface and tossed across the surface by a cratering event, appears <span class="hlt">bright</span>. But as the newly exposed surface is subjected to the harsh space environment, it darkens. This is one technique scientists use to date features on surfaces. This view looks toward the trailing hemisphere of Rhea. North on Rhea is up and rotated 21 degrees to the left. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on July 29, 2013. The view was obtained at a distance of approximately 1.0 million miles (1.6 million kilometers) fro http://photojournal.jpl.nasa.gov/catalog/PIA18300</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001ApJS..132..129M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001ApJS..132..129M"><span>An Ultraviolet/Optical Atlas of <span class="hlt">Bright</span> Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marcum, Pamela M.; O'Connell, Robert W.; Fanelli, Michael N.; Cornett, Robert H.; Waller, William H.; Bohlin, Ralph C.; Neff, Susan G.; Roberts, Morton S.; Smith, Andrew M.; Cheng, K.-P.; Collins, Nicholas R.; Hennessy, Gregory S.; Hill, Jesse K.; Hill, Robert S.; Hintzen, Paul; Landsman, Wayne B.; Ohl, Raymond G.; Parise, Ronald A.; Smith, Eric P.; Freedman, Wendy L.; Kuchinski, Leslie E.; Madore, Barry; Angione, Ronald; Palma, Christopher; Talbert, Freddie; Stecher, Theodore P.</p> <p>2001-02-01</p> <p>We present wide-field imagery and photometry of 43 selected nearby galaxies of all morphological types at ultraviolet and optical wavelengths. The ultraviolet (UV) images, in two broad bands at 1500 and 2500 Å, were obtained using the Ultraviolet Imaging Telescope (UIT) during the Astro-1 Spacelab mission. The UV images have ~3" resolution, and the comparison sets of ground-based CCD images (in one or more of B, V, R, and Hα) have pixel scales and fields of view closely matching the UV frames. The atlas consists of multiband images and plots of UV/optical surface <span class="hlt">brightness</span> and color profiles. Other associated parameters, such as integrated photometry and half-light radii, are tabulated. In an appendix, we discuss the sensitivity of different wavebands to a galaxy's star formation history in the form of ``history weighting functions'' and emphasize the importance of UV observations as probes of evolution during the past 10-1000 Myr. We find that UV galaxy morphologies are usually significantly different from visible band morphologies as a consequence of spatially inhomogeneous stellar populations. Differences are quite pronounced for systems in the middle range of Hubble types, Sa through Sc, but less so for ellipticals or late-type disks. Normal ellipticals and large spiral bulges are fainter and more compact in the UV. However, they typically exhibit smooth UV profiles with far-UV/optical color gradients which are larger than any at optical/IR wavelengths. The far-UV light in these cases is probably produced by extreme <span class="hlt">horizontal</span> branch stars and their descendants in the dominant, low-mass, metal-rich population. The cool stars in the large bulges of Sa and Sb spirals fade in the UV while hot OB stars in their disks brighten, such that their Hubble classifications become significantly later. In the far-UV, early-type spirals often appear as peculiar, ringlike systems. In some spiral disks, UV-<span class="hlt">bright</span> structures closely outline the spiral pattern; in others, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870037740&hterms=mass+wasting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dmass%2Bwasting','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870037740&hterms=mass+wasting&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dmass%2Bwasting"><span>Lunar and Venusian radar <span class="hlt">bright</span> rings</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thompson, T. W.; Saunders, R. S.; Weissman, D. E.</p> <p>1986-01-01</p> <p>Twenty-one lunar craters have radar <span class="hlt">bright</span> ring appearances which are analogous to eleven complete ring features in the earth-based 12.5 cm observations of Venus. Radar ring diameters and widths for the lunar and Venusian features overlap for sizes from 45 to 100 km. Radar <span class="hlt">bright</span> areas for the lunar craters are associated with the slopes of the inner and outer rim walls, while level crater floors and level ejecta fields beyond the raised portion of the rim have average radar backscatter. It is proposed that the radar <span class="hlt">bright</span> areas of the Venusian rings are also associated with the slopes on the rims of craters. The lunar craters have evolved to radar <span class="hlt">bright</span> rings via mass wasting of crater rim walls and via post-impact flooding of crater floors. Aeolian deposits of fine-grained material on Venusian crater floors may produce radar scattering effects similar to lunar crater floor flooding. These Venusian aeolian deposits may preferentially cover blocky crater floors producing a radar <span class="hlt">bright</span> ring appearance. It is proposed that the Venusian features with complete <span class="hlt">bright</span> ring appearances and sizes less than 100 km are impact craters. They have the same sizes as lunar craters and could have evolved to radar <span class="hlt">bright</span> rings via analogous surface processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.A13D0289D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.A13D0289D"><span>Understanding Climate Trends Using IR <span class="hlt">Brightness</span> Temperature Spectra from AIRS, IASI and CrIS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deslover, D. H.; Nikolla, E.; Knuteson, R. O.; Revercomb, H. E.; Tobin, D. C.</p> <p>2016-12-01</p> <p>NASA's Atmospheric Infrared Sounder (AIRS) provides a data record that extends from its 2002 launch to the present. The Infrared Atmospheric Sounding Interferometer (IASI) onboard Metop- (A launched in 2006, B in 2012), as well as the Joint <span class="hlt">Polar</span> Satellite System (JPSS) Cross-track Infrared Sounder (CrIS) launched in 2011, complement this data record. Future infrared sounders with similar capabilities will augment these measurements into the near future. We have created a global data set from these infrared measurements, using the nadir-most observations for each of the aforementioned instruments. We can filter the data based upon spatial, diurnal and seasonal properties to discern trends for a given spectral channel and, therefore, a specific atmospheric layer. Subtle differences between spectral sampling among the three instruments can lead significant differences in the resultant probability distribution functions for similar spectral channels. We take advantage of the higher (0.25 cm-1) IASI spectral resolution to subsample the IASI spectra onto AIRS and CrIS spectral grids to better compare AIRS/IASI and CrIS/IASI trends in the <span class="hlt">brightness</span> temperature anomalies. To better understand the dependance of trace gases on the measured <span class="hlt">brightness</span> temperature spectral time-series, a companion study has utilized coincident vertical profiles of stratospheric carbon dioxide, water vapor and ozone concentration are used to infer a correlation with the CrIS <span class="hlt">brightness</span> temperatures. The goal was to investigate the role of ozone heating and carbon dioxide cooling on the observed <span class="hlt">brightness</span> temperature spectra. Results from that study will be presented alongside the climate trend analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23187469','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23187469"><span>Design of LED fish lighting attractors using <span class="hlt">horizontal</span>/vertical LIDC mapping method.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shen, S C; Huang, H J</p> <p>2012-11-19</p> <p>This study employs a sub-module concept to develop high-<span class="hlt">brightness</span> light-emitting diode (HB-LED) fishing light arrays to replace traditional fishing light attractors. The <span class="hlt">horizontal</span>/vertical (H/V) plane light intensity distribution curve (LIDC) of a LED light source are mapped to assist in the design of a non-axisymmetric lens with a fish-attracting light pattern that illuminates sufficiently large areas and alternates between <span class="hlt">bright</span> and dark. These LED fishing light attractors are capable of attracting schools of fish toward the perimeter of the luminous zone surrounding fishing boats. Three CT2 boats (10 to 20 ton capacity) were recruited to conduct a field test for 1 y on the sea off the southwestern coast of Taiwan. Field tests show that HB-LED fishing light array installed 5 m above the boat deck illuminated a sea surface of 5 × 12 m and achieved an illuminance of 2000 lx. The test results show that the HB-LED fishing light arrays increased the mean catch of the three boats by 5% to 27%. In addition, the experimental boats consumed 15% to 17% less fuel than their counterparts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23232206O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23232206O"><span>A Very Large Array Survey of <span class="hlt">Polar</span> BAL Quasar Candidates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Olson, Kianna Alexandra; Brotherton, Michael S.; DiPompeo, Michael; Maithil, Jaya</p> <p>2018-06-01</p> <p><span class="hlt">Polar</span> broad absorption line quasars posses flat radio spectra and jets seen at small angles to the line of sight. Using the VLA we observed twelve <span class="hlt">polar</span> broad absorption line quasar candidates at L (1.5GHz), C (4.5-5.5GHz), and X (8.5-9.5GHz) bands, and found that their cores display flat spectra. Compared to previous observations in the NVSS and First surveys, the peak flux densities all show significant variation σvar > 3, and <span class="hlt">brightness</span> temperatures TB ≥ 1012K. Based on these findings, our quasars have the properties expected for objects that posses jets seen nearly pole on.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10407E..12X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10407E..12X"><span>Active <span class="hlt">polarization</span> imaging system based on optical heterodyne balanced receiver</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Qian; Sun, Jianfeng; Lu, Zhiyong; Zhou, Yu; Luan, Zhu; Hou, Peipei; Liu, liren</p> <p>2017-08-01</p> <p>Active <span class="hlt">polarization</span> imaging technology has recently become the hot research field all over the world, which has great potential application value in the military and civil area. By introducing active light source, the Mueller matrix of the target can be calculated according to the incident light and the emitted or reflected light. Compared with conventional direct detection technology, optical heterodyne detection technology have higher receiving sensitivities, which can obtain the whole amplitude, frequency and phase information of the signal light. In this paper, an active <span class="hlt">polarization</span> imaging system will be designed. Based on optical heterodyne balanced receiver, the system can acquire the <span class="hlt">horizontal</span> and vertical <span class="hlt">polarization</span> of reflected optical field simultaneously, which contain the <span class="hlt">polarization</span> characteristic of the target. Besides, signal to noise ratio and imaging distance can be greatly improved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013OptCo.296...95Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013OptCo.296...95Z"><span>Tight focusing properties of the azimuthal discrete phase modulated radially <span class="hlt">polarized</span> LG11* beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Jiang; Li, Bo; Zhao, Heng; Hu, Yi; Wang, Wenjin; Wang, Youqing</p> <p>2013-06-01</p> <p>An novel method for generating an annual periodic optical chain by tight focusing the rotational symmetric π/0 phase plate modulated first order radially <span class="hlt">polarized</span> Laguerre Gaussian (LG11*) beam with a high-NA lens is proposed. The optical chain is composed of either <span class="hlt">bright</span> spots or dark spots. Vector diffraction numerical calculation method is employed to analyze the tight focus properties. The analyses indicate that the properties of the optical chains are closely related to the number of phase plate sectors, beam width of radially <span class="hlt">polarized</span> LG11* beam and the numerical aperture of focusing lens. Furthermore, the average Full Width at Half Maximum (FWHM) of hollow dark spots or <span class="hlt">bright</span> spots in optical chain is breaking the diffraction limit. These kinds of annular optical chains are expected to be applied in trapping or arranging multiple bar-like micro particles whose refractive index are either higher or lower than that of the ambient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=343212','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=343212"><span>Wavelength and <span class="hlt">polarization</span> affect phototaxis of the Asian citrus psyllid</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>The Asian citrus psyllid, D. citri, is a primary pest for citrus production due to its status as a vector of the citrus disease, huanglongbing. We investigated phototactic behavior of D. citri to evaluate effects of light of specific wavelength or <span class="hlt">polarization</span> using a <span class="hlt">horizontal</span> bioassay arena. Wave...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRA..123..901G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRA..123..901G"><span><span class="hlt">Polarization</span> of Narrowband VLF Transmitter Signals as an Ionospheric Diagnostic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gross, N. C.; Cohen, M. B.; Said, R. K.; Gołkowski, M.</p> <p>2018-01-01</p> <p>Very low frequency (VLF, 3-30 kHz) transmitter remote sensing has long been used as a simple yet useful diagnostic for the D region ionosphere (60-90 km). All it requires is a VLF radio receiver that records the amplitude and/or phase of a beacon signal as a function of time. During both ambient and disturbed conditions, the received signal can be compared to predictions from a theoretical model to infer ionospheric waveguide properties like electron density. Amplitude and phase have in most cases been analyzed each as individual data streams, often only the amplitude is used. Scattered field formulation combines amplitude and phase effectively, but does not address how to combine two magnetic field components. We present <span class="hlt">polarization</span> ellipse analysis of VLF transmitter signals using two <span class="hlt">horizontal</span> components of the magnetic field. The shape of the <span class="hlt">polarization</span> ellipse is unchanged as the source phase varies, which circumvents a significant problem where VLF transmitters have an unknown source phase. A synchronized two-channel MSK demodulation algorithm is introduced to mitigate 90° ambiguity in the phase difference between the <span class="hlt">horizontal</span> magnetic field components. Additionally, the synchronized demodulation improves phase measurements during low-SNR conditions. Using the <span class="hlt">polarization</span> ellipse formulation, we take a new look at diurnal VLF transmitter variations, ambient conditions, and ionospheric disturbances from solar flares, lightning-ionospheric heating, and lightning-induced electron precipitation, and find differing signatures in the <span class="hlt">polarization</span> ellipse.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE10255E..14L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE10255E..14L"><span>Fabrication of the <span class="hlt">polarization</span> independent spectral beam combining grating</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Quan; Jin, Yunxia; Wu, Jianhong; Guo, Peiliang</p> <p>2016-03-01</p> <p>Owing to damage, thermal issues, and nonlinear optical effects, the output power of fiber laser has been proven to be limited. Beam combining techniques are the attractive solutions to achieve high-power high-<span class="hlt">brightness</span> fiber laser output. The spectral beam combining (SBC) is a promising method to achieve high average power output without influencing the beam quality. A <span class="hlt">polarization</span> independent spectral beam combining grating is one of the key elements in the SBC. In this paper the diffraction efficiency of the grating is investigated by rigorous coupled-wave analysis (RCWA). The theoretical -1st order diffraction efficiency of the grating is more than 95% from 1010nm to 1080nm for both TE and TM <span class="hlt">polarizations</span>. The fabrication tolerance is analyzed. The <span class="hlt">polarization</span> independent spectral beam combining grating with the period of 1.04μm has been fabricated by holographic lithography - ion beam etching, which are within the fabrication tolerance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18653259','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18653259"><span><span class="hlt">Bright</span>Stat.com: free statistics online.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stricker, Daniel</p> <p>2008-10-01</p> <p>Powerful software for statistical analysis is expensive. Here I present <span class="hlt">Bright</span>Stat, a statistical software running on the Internet which is free of charge. <span class="hlt">Bright</span>Stat's goals, its main capabilities and functionalities are outlined. Three different sample runs, a Friedman test, a chi-square test, and a step-wise multiple regression are presented. The results obtained by <span class="hlt">Bright</span>Stat are compared with results computed by SPSS, one of the global leader in providing statistical software, and VassarStats, a collection of scripts for data analysis running on the Internet. Elementary statistics is an inherent part of academic education and <span class="hlt">Bright</span>Stat is an alternative to commercial products.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19940020407&hterms=CO2+H2O&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DCO2%2BH2O','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19940020407&hterms=CO2+H2O&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DCO2%2BH2O"><span>Impact of the CO2 and H2O clouds of the Martian <span class="hlt">polar</span> hood on the <span class="hlt">polar</span> energy balance</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Forget, Francois; Pollack, James B.</p> <p>1993-01-01</p> <p>Clouds covering extensive areas above the martian <span class="hlt">polar</span> caps have regularly been observed during the fall and winter seasons of each hemisphere. These '<span class="hlt">polar</span> hoods' are thought to be made of H2O and CO2. In particular, the very cold temperatures observed during the <span class="hlt">polar</span> night by Viking and Mariner 9 around both poles have been identified as CO2 clouds and several models, including GCM, have indicated that the CO2 can condense in the atmosphere at all <span class="hlt">polar</span> latitudes. Estimating the impact of the <span class="hlt">polar</span> hood clouds on the energy balance of the <span class="hlt">polar</span> regions is necessary to model the CO2 cycle and address puzzling problems like the <span class="hlt">polar</span> caps assymetry. For example, by altering the thermal radiation emitted to space, CO2 clouds alter the amount of CO2 that condenses during the fall and winter season. The complete set of Viking IRTM data was analyzed to define the spatial and temporal properties of the <span class="hlt">polar</span> hoods, and how their presence affects the energy radiated by the atmosphere/caps system to space was estimated. The IRTM observations provide good spatial and temporal converage of both <span class="hlt">polar</span> regions during fall, winter, and spring, when a combination of the first and the second Viking year is used. Only the IRTM <span class="hlt">brightness</span> temperatures at 11, 15, and 20 microns are reliable at martian <span class="hlt">polar</span> temperatures. To recover the integrated thermal fluxes from the IRTM data, a simple model of the <span class="hlt">polar</span> hood, thought to consist of 'warm' H2O clouds lying above colder and opaque CO2 clouds was developed. Such a model is based on the analysis of the IRIS spectra, and is consistent with the IRTM data used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28790325','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28790325"><span><span class="hlt">Horizontal</span> mantle flow controls subduction dynamics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ficini, E; Dal Zilio, L; Doglioni, C; Gerya, T V</p> <p>2017-08-08</p> <p>It is generally accepted that subduction is driven by downgoing-plate negative buoyancy. Yet plate age -the main control on buoyancy- exhibits little correlation with most of the present-day subduction velocities and slab dips. "West"-directed subduction zones are on average steeper (~65°) than "East"-directed (~27°). Also, a "westerly"-directed net rotation of the lithosphere relative to the mantle has been detected in the hotspot reference frame. Thus, the existence of an "easterly"-directed <span class="hlt">horizontal</span> mantle wind could explain this subduction asymmetry, favouring steepening or lifting of slab dip angles. Here we test this hypothesis using high-resolution two-dimensional numerical thermomechanical models of oceanic plate subduction interacting with a mantle flow. Results show that when subduction <span class="hlt">polarity</span> is opposite to that of the mantle flow, the descending slab dips subvertically and the hinge retreats, thus leading to the development of a back-arc basin. In contrast, concordance between mantle flow and subduction <span class="hlt">polarity</span> results in shallow dipping subduction, hinge advance and pronounced topography of the overriding plate, regardless of their age-dependent negative buoyancy. Our results are consistent with seismicity data and tomographic images of subduction zones. Thus, our models may explain why subduction asymmetry is a common feature of convergent margins on Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19970027529&hterms=physical+activity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dphysical%2Bactivity','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19970027529&hterms=physical+activity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dphysical%2Bactivity"><span>Physical Retrievals of Over-Ocean Rain Rate from Multichannel Microwave Imagery. Part 1; Theoretical Characteristics of Normalized <span class="hlt">Polarization</span> and Scattering Indices</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Petty, G. W.</p> <p>1994-01-01</p> <p>Microwave rain rate retrieval algorithms have most often been formulated in terms of the raw <span class="hlt">brightness</span> temperatures observed by one or more channels of a satellite radiometer. Taken individually, single-channel <span class="hlt">brightness</span> temperatures generally represent a near-arbitrary combination of positive contributions due to liquid water emission and negative contributions due to scattering by ice and/or visibility of the radiometrically cold ocean surface. Unfortunately, for a given rain rate, emission by liquid water below the freezing level and scattering by ice particles above the freezing level are rather loosely coupled in both a physical and statistical sense. Furthermore, microwave <span class="hlt">brightness</span> temperatures may vary significantly (approx. 30-70 K) in response to geophysical parameters other than liquid water and precipitation. Because of these complications, physical algorithms which attempt to directly invert observed <span class="hlt">brightness</span> temperatures have typically relied on the iterative adjustment of detailed micro-physical profiles or cloud models, guided by explicit forward microwave radiative transfer calculations. In support of an effort to develop a significantly simpler and more efficient inversion-type rain rate algorithm, the physical information content of two linear transformations of single-frequency, dual-<span class="hlt">polarization</span> <span class="hlt">brightness</span> temperatures is studied: the normalized <span class="hlt">polarization</span> difference P of Petty and Katsaros (1990, 1992), which is intended as a measure of footprint-averaged rain cloud transmittance for a given frequency; and a scattering index S (similar to the <span class="hlt">polarization</span> corrected temperature of Spencer et al.,1989) which is sensitive almost exclusively to ice. A reverse Monte Carlo radiative transfer model is used to elucidate the qualitative response of these physically distinct single-frequency indices to idealized 3-dimensional rain clouds and to demonstrate their advantages over raw <span class="hlt">brightness</span> temperatures both as stand-alone indices of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptCo.416....1H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptCo.416....1H"><span>Generation of <span class="hlt">polarization</span> squeezed light with an optical parametric amplifier at 795 nm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Han, Yashuai; Wen, Xin; Liu, Jinyu; He, Jun; Wang, Junmin</p> <p>2018-06-01</p> <p>We report the experimental demonstration of <span class="hlt">polarization</span> squeezed beam at 795 nm by combining a quadrature amplitude squeezed beam with an in-phase <span class="hlt">bright</span> coherent beam. The quadrature amplitude squeezed beam is generated by a degenerate optical parametric amplifier based on a PPKTP crystal. Stokes operators Sˆ2 squeezing of -3.8 dB and Sˆ3 anti-squeezing of +5.0 dB have been observed. This <span class="hlt">polarization</span> squeezed beam resonant to rubidium D1 line has potential applications in quantum information networks and precision measurement beyond the shot noise limit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21044607','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21044607"><span>Characterization of <span class="hlt">brightness</span> and stoichiometry of <span class="hlt">bright</span> particles by flow-fluorescence fluctuation spectroscopy.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Johnson, Jolene; Chen, Yan; Mueller, Joachim D</p> <p>2010-11-03</p> <p>Characterization of <span class="hlt">bright</span> particles at low concentrations by fluorescence fluctuation spectroscopy (FFS) is challenging, because the event rate of particle detection is low and fluorescence background contributes significantly to the measured signal. It is straightforward to increase the event rate by flow, but the high background continues to be problematic for fluorescence correlation spectroscopy. Here, we characterize the use of photon-counting histogram analysis in the presence of flow. We demonstrate that a photon-counting histogram efficiently separates the particle signal from the background and faithfully determines the <span class="hlt">brightness</span> and concentration of particles independent of flow speed, as long as undersampling is avoided. <span class="hlt">Brightness</span> provides a measure of the number of fluorescently labeled proteins within a complex and has been used to determine stoichiometry of protein complexes in vivo and in vitro. We apply flow-FFS to determine the stoichiometry of the group specific antigen protein within viral-like particles of the human immunodeficiency virus type-1 from the <span class="hlt">brightness</span>. Our results demonstrate that flow-FFS is a sensitive method for the characterization of complex macromolecular particles at low concentrations. Copyright © 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFM.C13D0859R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFM.C13D0859R"><span>Glacier Melt Detection in Complex Terrain Using New AMSR-E Calibrated Enhanced Daily EASE-Grid 2.0 <span class="hlt">Brightness</span> Temperature (CETB) Earth System Data Record</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramage, J. M.; Brodzik, M. J.; Hardman, M.</p> <p>2016-12-01</p> <p>Passive microwave (PM) 18 GHz and 36 GHz <span class="hlt">horizontally</span>- and vertically-<span class="hlt">polarized</span> <span class="hlt">brightness</span> temperatures (Tb) channels from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) have been important sources of information about snow melt status in glacial environments, particularly at high latitudes. PM data are sensitive to the changes in near-surface liquid water that accompany melt onset, melt intensification, and refreezing. Overpasses are frequent enough that in most areas multiple (2-8) observations per day are possible, yielding the potential for determining the dynamic state of the snow pack during transition seasons. AMSR-E Tb data have been used effectively to determine melt onset and melt intensification using daily Tb and diurnal amplitude variation (DAV) thresholds. Due to mixed pixels in historically coarse spatial resolution Tb data, melt analysis has been impractical in ice-marginal zones where pixels may be only fractionally snow/ice covered, and in areas where the glacier is near large bodies of water: even small regions of open water in a pixel severely impact the microwave signal. We use the new enhanced-resolution Calibrated Passive Microwave Daily EASE-Grid 2.0 <span class="hlt">Brightness</span> Temperature (CETB) Earth System Data Record product's twice daily obserations to test and update existing snow melt algorithms by determining appropriate melt thresholds for both Tb and DAV for the CETB 18 and 36 GHz channels. We use the enhanced resolution data to evaluate melt characteristics along glacier margins and melt transition zones during the melt seasons in locations spanning a wide range of melt scenarios, including the Patagonian Andes, the Alaskan Coast Range, and the Russian High Arctic icecaps. We quantify how improvement of spatial resolution from the original 12.5 - 25 km-scale pixels to the enhanced resolution of 3.125 - 6.25 km improves the ability to evaluate melt timing across boundaries and transition zones in diverse glacial environments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA12753.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA12753.html"><span><span class="hlt">Bright</span> Enceladus</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2011-02-14</p> <p>Saturn moon Enceladus reflects sunlight <span class="hlt">brightly</span> while the planet and its rings fill the background in this view from NASA Cassini spacecraft. Enceladus is one of the most reflective bodies in the solar system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760017595','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760017595"><span>Results of soil moisture flights during April 1974</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schmugge, T. J.; Blanchard, B. J.; Burke, W. J.; Paris, J. F.; Swang, J. R.</p> <p>1976-01-01</p> <p>The results presented here are derived from measurements made during the April 5 and 6, 1974 flights of the NASA P-3A aircraft over the Phoenix, Arizona agricultural test site. The purpose of the mission was to study the use of microwave techniques for the remote sensing of soil moisture. These results include infrared (10-to 12 micrometers) 2.8-cm and 21-cm <span class="hlt">brightness</span> temperatures for approximately 90 bare fields. These <span class="hlt">brightness</span> temperatures are compared with surface measurements of the soil moisture made at the time of the overflights. These data indicate that the combination of the sum and difference of the vertically and the <span class="hlt">horizontally</span> <span class="hlt">polarized</span> <span class="hlt">brightness</span> temperatures yield information on both the soil moisture and surface roughness conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...842...41F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...842...41F"><span>The O2 A-Band in the Fluxes and <span class="hlt">Polarization</span> of Starlight Reflected by Earth-Like Exoplanets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fauchez, Thomas; Rossi, Loic; Stam, Daphne M.</p> <p>2017-06-01</p> <p>Earth-like, potentially habitable exoplanets are prime targets in the search for extraterrestrial life. Information about their atmospheres and surfaces can be derived by analyzing the light of the parent star reflected by the planet. We investigate the influence of the surface albedo A s, the optical thickness b cloud, the altitude of water clouds, and the mixing ratio of biosignature O2 on the strength of the O2 A-band (around 760 nm) in the flux and <span class="hlt">polarization</span> spectra of starlight reflected by Earth-like exoplanets. Our computations for <span class="hlt">horizontally</span> homogeneous planets show that small mixing ratios (η < 0.4) will yield moderately deep bands in flux and moderate-to-small band strengths in <span class="hlt">polarization</span>, and that clouds will usually decrease the band depth in flux and the band strength in <span class="hlt">polarization</span>. However, cloud influence will be strongly dependent on properties such as optical thickness, top altitude, particle phase, coverage fraction, and <span class="hlt">horizontal</span> distribution. Depending on the surface albedo and cloud properties, different O2 mixing ratios η can give similar absorption-band depths in flux and band strengths in <span class="hlt">polarization</span>, especially if the clouds have moderate-to-high optical thicknesses. Measuring both the flux and the <span class="hlt">polarization</span> is essential to reduce the degeneracies, although it will not solve them, especially not for <span class="hlt">horizontally</span> inhomogeneous planets. Observations at a wide range of phase angles and with a high temporal resolution could help to derive cloud properties and, once those are known, the mixing ratio of O2 or any other absorbing gas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20833931','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20833931"><span><span class="hlt">Polarization</span> sensitivity and retinal topography of the striped pyjama squid (Sepioloidea lineolata - Quoy/Gaimard 1832).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Talbot, Christopher M; Marshall, Justin</p> <p>2010-10-01</p> <p>Coleoid cephalopods (octopus, cuttlefish and squid) potentially possess <span class="hlt">polarization</span> sensitivity (PS) based on photoreceptor structure, but this idea has rarely been tested behaviourally. Here, we use a <span class="hlt">polarized</span>, striped optokinetic stimulus to demonstrate PS in the striped pyjama squid, Sepioloidea lineolata. This species displayed strong, consistent optokinetic nystagmic eye movements in response to a drum with stripes producing e-vectors set to 0 deg, 45 deg, 90 deg and 135 deg that would only be visible to an animal with PS. This is the first behavioural demonstration of a <span class="hlt">polarized</span> optokinetic response in any species of cephalopod. This species, which typically sits beneath the substrate surface looking upwards for potential predators and prey, possesses a dorsally shifted <span class="hlt">horizontal</span> pupil slit. Accordingly, it was found to possess a <span class="hlt">horizontal</span> strip of high-density photoreceptors shifted ventrally in the retina, suggesting modifications such as a change in sensitivity or resolution to the dorsal visual field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23798032','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23798032"><span><span class="hlt">Brightness</span> and transparency in the early visual cortex.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Salmela, Viljami R; Vanni, Simo</p> <p>2013-06-24</p> <p>Several psychophysical studies have shown that transparency can have drastic effects on <span class="hlt">brightness</span> and lightness. However, the neural processes generating these effects have remained unresolved. Several lines of evidence suggest that the early visual cortex is important for <span class="hlt">brightness</span> perception. While single cell recordings suggest that surface <span class="hlt">brightness</span> is represented in the primary visual cortex, the results of functional magnetic resonance imaging (fMRI) studies have been discrepant. In addition, the location of the neural representation of transparency is not yet known. We investigated whether the fMRI responses in areas V1, V2, and V3 correlate with <span class="hlt">brightness</span> and transparency. To dissociate the blood oxygen level-dependent (BOLD) response to <span class="hlt">brightness</span> from the response to local border contrast and mean luminance, we used variants of White's <span class="hlt">brightness</span> illusion, both opaque and transparent, in which luminance increments and decrements cancel each other out. The stimuli consisted of a target surface and a surround. The surround luminance was always sinusoidally modulated at 0.5 Hz to induce <span class="hlt">brightness</span> modulation to the target. The target luminance was constant or modulated in counterphase to null <span class="hlt">brightness</span> modulation. The mean signal changes were calculated from the voxels in V1, V2, and V3 corresponding to the retinotopic location of the target surface. The BOLD responses were significantly stronger for modulating <span class="hlt">brightness</span> than for stimuli with constant <span class="hlt">brightness</span>. In addition, the responses were stronger for transparent than for opaque stimuli, but there was more individual variation. No interaction between <span class="hlt">brightness</span> and transparency was found. The results show that the early visual areas V1-V3 are sensitive to surface <span class="hlt">brightness</span> and transparency and suggest that <span class="hlt">brightness</span> and transparency are represented separately.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760060742&hterms=sparrow&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsparrow','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760060742&hterms=sparrow&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsparrow"><span><span class="hlt">Polarization</span> of the zodiacal light - First results from Skylab</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sparrow, J. G.; Weinberg, J. L.; Hahn, R. C.</p> <p>1976-01-01</p> <p>A brief description is given of the Skylab ten color photoelectric photometer and the programs of measurements made during Skylab missions SL-2 and SL-3. Results obtained on the <span class="hlt">polarized</span> <span class="hlt">brightness</span> of zodiacal light at five points on the antisolar hemisphere are discussed and compared with other published data for the north celestial pole, south ecliptic pole, at elongation 90 degrees on the ecliptic, and at two places near the north galactic pole.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/6183986-structural-interpretation-from-horizontal-seismic-sections','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/6183986-structural-interpretation-from-horizontal-seismic-sections"><span>Structural interpretation from <span class="hlt">horizontal</span> seismic sections</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Brown, A.R.</p> <p>1983-03-01</p> <p>The interpreter of a 3D survey must use a data volume. <span class="hlt">Horizontal</span> slices through a data volume, called Seiscrop sections, have unique properties and structural interpretation from them is fast, convenient, and effective. An event on a Seiscrop section displays local strike, a property which permits direct contouring of a structural surface without any timing and posting. The width of an event on a Seiscrop section is a composition of the frequency of the data and the structural dip. Event terminations indicate faults or other discontinuities when they are transverse to structural strike. Faults parallel to structural strike are muchmore » less evident on a single Seiscrop section but become apparent with the relative movement of events from section to section. In practical mapping, we normally contour one fault block before proceeding to the next with the correlation between them being established from the vertical sections. With dual <span class="hlt">polarity</span> variable area displays, the interpreter can perceive five amplitude levels and normally picks the edge of a trough. With color amplitude Seiscrop sections, it is possible to pick on the crest of any event. With color phase sections the interpreter can pick at any arbitrary but consistent point on the seismic waveform. Subtle structural features are commonly revealed on <span class="hlt">horizontal</span> sections which may never have been noticed if working from vertical sections alone.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EL....12030001Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EL....12030001Y"><span><span class="hlt">Bright</span>-dark solitons for a set of the general coupled nonlinear Schrödinger equations in a birefringent fiber</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yuan, Yu-Qiang; Tian, Bo; Liu, Lei; Sun, Yan</p> <p>2017-11-01</p> <p>Under investigation in this paper is the coupled nonlinear Schrödinger equations with the four-wave mixing term, which describe the optical solitons in a birefringent fiber. Via the Kadomtsev-Petviashvili hierarchy reduction, we obtain the N-<span class="hlt">bright</span>-dark soliton solutions in terms of the Gram determinant. Propagation and interaction of the solitons corresponding to the electric fields in the two orthogonal <span class="hlt">polarizations</span> are discussed and presented graphically. We find that the one <span class="hlt">bright</span>-dark soliton possesses the periodic oscillation and exhibits the breather-like profile, which is different from that in the previous literature. Besides, for the one soliton, we observe that the larger velocity leads to the fiercer oscillation. Elastic interactions including the head-on and overtaking interactions between the two <span class="hlt">bright</span>-dark solitons are demonstrated. Particularly, we find the oblique inelastic interaction between the two <span class="hlt">bright</span>-dark solitons, which possess the V-shape profile in the zero background component and the Y-shape profile in the nonzero background component. Besides, we present two cases of the bound-state solitons. For the one case, the two solitons interact with each other all the time along a direction and for the other case, the resonance phenomenon is raised.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9730E..0CH','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9730E..0CH"><span>Teradiode's high <span class="hlt">brightness</span> semiconductor lasers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, Robin K.; Chann, Bien; Burgess, James; Lochman, Bryan; Zhou, Wang; Cruz, Mike; Cook, Rob; Dugmore, Dan; Shattuck, Jeff; Tayebati, Parviz</p> <p>2016-03-01</p> <p>TeraDiode is manufacturing multi-kW-class ultra-high <span class="hlt">brightness</span> fiber-coupled direct diode lasers for industrial applications. A fiber-coupled direct diode laser with a power level of 4,680 W from a 100 μm core diameter, <0.08 numerical aperture (NA) output fiber at a single center wavelength was demonstrated. Our TeraBlade industrial platform achieves world-record <span class="hlt">brightness</span> levels for direct diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 3.5 mm-mrad and is the lowest BPP multi-kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 4-kW fiber-coupled direct diode laser has comparable <span class="hlt">brightness</span> to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers. We have also demonstrated novel high peak power lasers and high <span class="hlt">brightness</span> Mid-Infrared Lasers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20372659','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20372659"><span>Design of miniaturized silicon wire and slot waveguide <span class="hlt">polarization</span> splitterbased on a resonant tunneling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Komatsu, Masa-Aki; Saitoh, Kunimasa; Koshiba, Masanori</p> <p>2009-10-12</p> <p>We propose an ultra-small <span class="hlt">polarization</span> splitter based on a resonant tunneling phenomenon. This <span class="hlt">polarization</span> splitter consists of two identical <span class="hlt">horizontally</span> oblong silicon wire waveguides separated by a vertical slot waveguide. The structural parameters of the central resonant slot waveguide are designed to couple only the TM-like mode between the left and right side silicon wire waveguides. Results from numerical simulation with the full-vectorial beam propagation method show that a 16-mum-long <span class="hlt">polarization</span> splitter with extinction ratio better than -20 dB on the entire C-band is achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018OptEn..57c7104S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018OptEn..57c7104S"><span>Broadband transverse magnetic pass <span class="hlt">polarizer</span> with low insertion loss based on silicon nitride waveguide</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sharma, Tarun Kumar; Ranganath, Praveen; Nambiar, Siddharth; Selvaraja, Shankar Kumar</p> <p>2018-03-01</p> <p>A <span class="hlt">horizontally</span> asymmetric transverse magnetic (TM) pass <span class="hlt">polarizer</span> is presented. The device passes only TM mode and rejects transverse electric (TE) mode. The proposed device has an asymmetricity in the <span class="hlt">horizontal</span> direction comprising a direction coupler region with a silicon waveguide, silicon nitride waveguide, and an air gap, all residing on silica. Between three equal width Si waveguides, we have one region filled with air and the other with SiN with unequal optimized widths. The device with its optimal dimensions yields an extremely low insertion loss (IL) of 0.16 dB for TM→TM, while TE is rejected by an IL of >48 dB. The proposed <span class="hlt">polarizer</span> is operated between C&L bands with a high extinction ratio and broadband width of about 110 nm.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApJ...763..138W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApJ...763..138W"><span>The Effect of Systematics on <span class="hlt">Polarized</span> Spectral Indices</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wehus, I. K.; Fuskeland, U.; Eriksen, H. K.</p> <p>2013-02-01</p> <p>We study four particularly <span class="hlt">bright</span> <span class="hlt">polarized</span> compact objects (Tau A, Vir A, 3C 273, and For A) in the 7 year Wilkinson Microwave Anisotropy Probe (WMAP) sky maps, with the goal of understanding potential systematics involved in the estimation of foreground spectral indices. First, we estimate the spectral index, the <span class="hlt">polarization</span> angle, the <span class="hlt">polarization</span> fraction, and the apparent size and shape of these objects when smoothed to a nominal resolution of 1° FWHM. Second, we compute the spectral index as a function of <span class="hlt">polarization</span> orientation, α. Because these objects are approximately point sources with constant <span class="hlt">polarization</span> angle, this function should be constant in the absence of systematics. However, for the K and Ka band WMAP data we find strong index variations for all four sources. For Tau A, we find a spectral index of β = -2.59 ± 0.03 for α = 30°, and β = -2.03 ± 0.01 for α = 50°. On the other hand, the spectral index between the Ka and Q bands is found to be stable. A simple elliptical Gaussian toy model with parameters matching those observed in Tau A reproduces the observed signal, and shows that the spectral index is particularly sensitive to the detector <span class="hlt">polarization</span> angle. Based on these findings, we first conclude that estimation of spectral indices with the WMAP K band <span class="hlt">polarization</span> data at 1° scales is not robust. Second, we note that these issues may be of concern for ground-based and sub-orbital experiments that use the WMAP <span class="hlt">polarization</span> measurements of Tau A for calibration of gain and <span class="hlt">polarization</span> angles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.loc.gov/pictures/collection/hh/item/in0213.sheet.00006a/','SCIGOV-HHH'); return false;" href="https://www.loc.gov/pictures/collection/hh/item/in0213.sheet.00006a/"><span><span class="hlt">Horizontal</span> Cross Bracing Detail, Vertical Cross Bracing Detail, <span class="hlt">Horizontal</span> Cross ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p><span class="hlt">Horizontal</span> Cross Bracing Detail, Vertical Cross Bracing Detail, <span class="hlt">Horizontal</span> Cross Bracing Detail, Vertical Cross Bracing-End Detail - Cumberland Covered Bridge, Spanning Mississinewa River, Matthews, Grant County, IN</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997DPS....29.2409C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997DPS....29.2409C"><span>Jupiter's <span class="hlt">Polar</span> Haze</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carlson, B. E.</p> <p>1997-07-01</p> <p>The nature and distribution of stratospheric aerosols in the <span class="hlt">polar</span> regions of Jupiter are investigated using a combination of ground-based, Hubble Space Telescope (HST), and Voyager IRIS measurements. Of particular interest are the connections between the enhanced UV absorption in the <span class="hlt">polar</span> regions and the <span class="hlt">bright</span> <span class="hlt">polar</span> hoods evident in methane band images and the connections between the aerosol, the infrared "hot spot", and the auroras. Spatial maps of the hydrocarbon emissions constructed from the Voyager IRIS measurements reveal enhanced acetylene emission coincident with the region of enhanced methane emission but morphologically distinct from the region of enhanced ethane emission. This finding confirms the existence of altitude- dependent hydrocarbon chemistry. Ground-based and HST data reveal the presence of longitudinal structure in the latitudinal distribution of the aerosols (i.e., break-down in zonal symmetry) apparently associated with circulation anomalies induced by the <span class="hlt">polar</span> hot spot. In addition, the HST data reveal a change in the aerosol properties (e.g., phase function) in the vicinity of the hot spot while ruling out changes in their height and/or optical depth distribution. The HST data also reveal differential UV absorption coincident with the aurora strengthening the connection between aerosol formation/hydrocarbon chemistry and the aurora. The spectral dependence of this absorption suggests enhancements of the higher order hydrocarbons (e.g., benzene). The mismatch in spatial resolution between infrared (Voyager IRIS/ground-based IRTF) and HST measurements coupled with the change in morphology of the hot spot as revealed by the structure of the methane/acetylene emission versus that of the ethane emission suggests the existence of more complex spatial structure and additional thermal emission anomalies associated with auroral processes unresolved by current infrared measurements</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24323112','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24323112"><span><span class="hlt">Brightness</span> perception of unrelated self-luminous colors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Withouck, Martijn; Smet, Kevin A G; Ryckaert, Wouter R; Pointer, Michael R; Deconinck, Geert; Koenderink, Jan; Hanselaer, Peter</p> <p>2013-06-01</p> <p>The perception of <span class="hlt">brightness</span> of unrelated self-luminous colored stimuli of the same luminance has been investigated. The Helmholtz-Kohlrausch (H-K) effect, i.e., an increase in <span class="hlt">brightness</span> perception due to an increase in saturation, is clearly observed. This <span class="hlt">brightness</span> perception is compared with the calculated <span class="hlt">brightness</span> according to six existing vision models, color appearance models, and models based on the concept of equivalent luminance. Although these models included the H-K effect and half of them were developed to work with unrelated colors, none of the models seemed to be able to fully predict the perceived <span class="hlt">brightness</span>. A tentative solution to increase the prediction accuracy of the color appearance model CAM97u, developed by Hunt, is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA21398.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA21398.html"><span>Occator <span class="hlt">Bright</span> Spots in 3-D</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2017-03-09</p> <p>This 3-D image, or anaglyph, shows the center of Occator Crater, the brightest area on dwarf planet Ceres, using data from NASA's Dawn mission. The <span class="hlt">bright</span> central area, including a dome that is 0.25 miles (400 meters) high, is called Cerealia Facula. The secondary, scattered <span class="hlt">bright</span> areas are called Vinalia Faculae. A 2017 study suggests that the central <span class="hlt">bright</span> area is significantly younger than Occator Crater. Estimates put Cerealia Facula at 4 million years old, while Occator Crater is approximately 34 million years old. The reflective material that appears so <span class="hlt">bright</span> in this image is made of carbonate salts, according to Dawn researchers. The Vinalia Faculae seem to be composed of carbonates mixed with dark material. http://photojournal.jpl.nasa.gov/catalog/PIA21398</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvS..21c2802T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvS..21c2802T"><span>Time-resolved <span class="hlt">brightness</span> measurements by streaking</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Torrance, Joshua S.; Speirs, Rory W.; McCulloch, Andrew J.; Scholten, Robert E.</p> <p>2018-03-01</p> <p><span class="hlt">Brightness</span> is a key figure of merit for charged particle beams, and time-resolved <span class="hlt">brightness</span> measurements can elucidate the processes involved in beam creation and manipulation. Here we report on a simple, robust, and widely applicable method for the measurement of beam <span class="hlt">brightness</span> with temporal resolution by streaking one-dimensional pepperpots, and demonstrate the technique to characterize electron bunches produced from a cold-atom electron source. We demonstrate <span class="hlt">brightness</span> measurements with 145 ps temporal resolution and a minimum resolvable emittance of 40 nm rad. This technique provides an efficient method of exploring source parameters and will prove useful for examining the efficacy of techniques to counter space-charge expansion, a critical hurdle to achieving single-shot imaging of atomic scale targets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20150006626&hterms=CAPS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCAPS','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20150006626&hterms=CAPS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCAPS"><span>Variations in Surface Texture of the North <span class="hlt">Polar</span> Residual Cap of Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Milkovich, S. M.; Byrne, S.; Russell, P. S.</p> <p>2011-01-01</p> <p>The northern <span class="hlt">polar</span> residual cap (NPRC) of Mars is a water ice deposit with a rough surface made up of pits, knobs, and linear depressions on scales of tens of meters. This roughness manifests as a series of <span class="hlt">bright</span> mounds and dark hollows in visible images; these <span class="hlt">bright</span> and dark patches have a characteristic wavelength and orientation. Spectral data indicate that the surface of the NPRC is composed of large-grained (and therefore old) water ice. Due to the presence of this old ice, it is thought that the NPRC is in a current state of net loss of material a result potentially at odds with impact crater statistics, which suggest ongoing deposition over the past 10-20 Kyr.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29041173','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29041173"><span>Non-sky <span class="hlt">polarization</span>-based dehazing algorithm for non-specular objects using <span class="hlt">polarization</span> difference and global scene feature.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qu, Yufu; Zou, Zhaofan</p> <p>2017-10-16</p> <p>Photographic images taken in foggy or hazy weather (hazy images) exhibit poor visibility and detail because of scattering and attenuation of light caused by suspended particles, and therefore, image dehazing has attracted considerable research attention. The current <span class="hlt">polarization</span>-based dehazing algorithms strongly rely on the presence of a "sky area", and thus, the selection of model parameters is susceptible to external interference of high-<span class="hlt">brightness</span> objects and strong light sources. In addition, the noise of the restored image is large. In order to solve these problems, we propose a <span class="hlt">polarization</span>-based dehazing algorithm that does not rely on the sky area ("non-sky"). First, a linear <span class="hlt">polarizer</span> is used to collect three <span class="hlt">polarized</span> images. The maximum- and minimum-intensity images are then obtained by calculation, assuming the <span class="hlt">polarization</span> of light emanating from objects is negligible in most scenarios involving non-specular objects. Subsequently, the <span class="hlt">polarization</span> difference of the two images is used to determine a sky area and calculate the infinite atmospheric light value. Next, using the global features of the image, and based on the assumption that the airlight and object radiance are irrelevant, the degree of <span class="hlt">polarization</span> of the airlight (DPA) is calculated by solving for the optimal solution of the correlation coefficient equation between airlight and object radiance; the optimal solution is obtained by setting the right-hand side of the equation to zero. Then, the hazy image is subjected to dehazing. Subsequently, a filtering denoising algorithm, which combines the <span class="hlt">polarization</span> difference information and block-matching and 3D (BM3D) filtering, is designed to filter the image smoothly. Our experimental results show that the proposed <span class="hlt">polarization</span>-based dehazing algorithm does not depend on whether the image includes a sky area and does not require complex models. Moreover, the dehazing image except specular object scenarios is superior to those obtained by Tarel</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950029339&hterms=Open+Field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DOpen%2BField','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950029339&hterms=Open+Field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DOpen%2BField"><span>A coronal magnetic field model with <span class="hlt">horizontal</span> volume and sheet currents</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhao, Xuepu; Hoeksema, J. Todd</p> <p>1994-01-01</p> <p>When globally mapping the observed photospheric magnetic field into the corona, the interaction of the solar wind and magnetic field has been treated either by imposing source surface boundary conditions that tacitly require volume currents outside the source surface or by limiting the interaction to thin current sheets between oppositely directed field regions. Yet observations and numerical Magnetohydrodynamic (MHD) calculations suggest the presence of non-force-free volume currents throughout the corona as well as thin current sheets in the neighborhoods of the interfaces between closed and open field lines or between oppositely directed open field lines surrounding coronal helmet-streamer structures. This work presents a model including both <span class="hlt">horizontal</span> volume currents and streamer sheet currents. The present model builds on the magnetostatic equilibria developed by Bogdan and Low and the current-sheet modeling technique developed by Schatten. The calculation uses synoptic charts of the line-of-sight component of the photospheric magnetic field measured at the Wilcox Solar Observatory. Comparison of an MHD model with the calculated model results for the case of a dipole field and comparison of eclipse observations with calculations for CR 1647 (near solar minimum) show that this <span class="hlt">horizontal</span> current-current-sheet model reproduces <span class="hlt">polar</span> plumes and axes of corona streamers better than the source-surface model and reproduces <span class="hlt">polar</span> plumes and axes of corona streamers better than the source-surface model and reproduces coro nal helmet structures better than the current-sheet model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23499321','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23499321"><span>Eye contrast <span class="hlt">polarity</span> is critical for face recognition by infants.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Otsuka, Yumiko; Motoyoshi, Isamu; Hill, Harold C; Kobayashi, Megumi; Kanazawa, So; Yamaguchi, Masami K</p> <p>2013-07-01</p> <p>Just as faces share the same basic arrangement of features, with two eyes above a nose above a mouth, human eyes all share the same basic contrast <span class="hlt">polarity</span> relations, with a sclera lighter than an iris and a pupil, and this is unique among primates. The current study examined whether this <span class="hlt">bright</span>-dark relationship of sclera to iris plays a critical role in face recognition from early in development. Specifically, we tested face discrimination in 7- and 8-month-old infants while independently manipulating the contrast <span class="hlt">polarity</span> of the eye region and of the rest of the face. This gave four face contrast <span class="hlt">polarity</span> conditions: fully positive condition, fully negative condition, positive face with negated eyes ("negative eyes") condition, and negated face with positive eyes ("positive eyes") condition. In a familiarization and novelty preference procedure, we found that 7- and 8-month-olds could discriminate between faces only when the contrast <span class="hlt">polarity</span> of the eyes was preserved (positive) and that this did not depend on the contrast <span class="hlt">polarity</span> of the rest of the face. This demonstrates the critical role of eye contrast <span class="hlt">polarity</span> for face recognition in 7- and 8-month-olds and is consistent with previous findings for adults. Copyright © 2013 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22649284-su-brb-polarity-effects-small-volume-ionization-chambers-small-fields','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22649284-su-brb-polarity-effects-small-volume-ionization-chambers-small-fields"><span>SU-G-BRB-12: <span class="hlt">Polarity</span> Effects in Small Volume Ionization Chambers in Small Fields</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Arora, V; Parsai, E; Mathew, D</p> <p>2016-06-15</p> <p>Purpose: Dosimetric quantities such as the <span class="hlt">polarity</span> correction factor (Ppol) are important parameters for determining the absorbed dose and can influence the choice of dosimeter. Ppol has been shown to depend on beam energy, chamber design, and field size. This study is to investigate the field size and detector orientation dependence of Ppol in small fields for several commercially available micro-chambers. Methods: We evaluate the Exradin A26, Exradin A16, PTW 31014, PTW 31016, and two prototype IBA CC-01 micro-chambers in both <span class="hlt">horizontal</span> and vertical orientations. Measurements were taken at 10cm depth and 100cm SSD in a Wellhofer BluePhantom2. Measurements weremore » made at square fields of 0.6, 0.8, 1.0, 1.2, 1.4, 2.0, 2.4, 3.0, and 5.0 cm on each side using 6MV with both ± 300VDC biases. PPol was evaluated as described in TG-51, reported using −300VDC bias for Mraw. Ratios of PPol measured in the clinical field to the reference field are presented. Results: A field size dependence of Ppol was observed for all chambers, with increased variations when mounted vertically. The maximum variation observed in PPol over all chambers mounted <span class="hlt">horizontally</span> was <1%, and occurred at different field sizes for different chambers. Vertically mounted chambers demonstrated variations as large as 3.2%, always at the smallest field sizes. Conclusion: Large variations in Ppol were observed for vertically mounted chambers compared to <span class="hlt">horizontal</span> mountings. <span class="hlt">Horizontal</span> mountings demonstrated a complicated relationship between <span class="hlt">polarity</span> variation and field size, probably relating to differing details in each chambers construction. Vertically mounted chambers consistently demonstrated the largest PPol variations for the smallest field sizes. Measurements obtained with a <span class="hlt">horizontal</span> mounting appear to not need significant <span class="hlt">polarity</span> corrections for relative measurements, while those obtained using a vertical mounting should be corrected for variations in PPol.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910013681','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910013681"><span>Weathering and erosion of the <span class="hlt">polar</span> layered deposits on Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Herkenhoff, K. E.</p> <p>1990-01-01</p> <p>The Martial <span class="hlt">polar</span> layered deposits are widely believed to be composed of water ice and silicates, but the relative amount of each component is unknown. The conventional wisdom among Mars researchers is that the deposits were formed by periodic variations in the deposition of dust and ice caused by climate changes over the last 10 to 100 million years. It is assumed here that water ice is an important constituent of the layered deposits, that the deposits were formed by eolian processes, and that the origin and evolution of the north and south <span class="hlt">polar</span> deposits were similar. Weathering of the layered deposits by sublimation of water ice can account for the geologic relationships in the <span class="hlt">polar</span> regions. The nonvolatile components of the layered deposits appears to consist mainly of <span class="hlt">bright</span> red dust, with small amounts of dark dust or sand. Dark dust, perhaps similar to the magnetic material found at the Viking Lander sites, may perferentially form filamentary residue particles upon weathering of the deposits. Once eroded, these particles may saltate to form the dark dunes found in both <span class="hlt">polar</span> regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvB..97o5403Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvB..97o5403Y"><span>Electromagnetically induced transparency control in terahertz metasurfaces based on <span class="hlt">bright-bright</span> mode coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yahiaoui, R.; Burrow, J. A.; Mekonen, S. M.; Sarangan, A.; Mathews, J.; Agha, I.; Searles, T. A.</p> <p>2018-04-01</p> <p>We demonstrate a classical analog of electromagnetically induced transparency (EIT) in a highly flexible planar terahertz metamaterial (MM) comprised of three-gap split-ring resonators. The keys to achieve EIT in this system are the frequency detuning and hybridization processes between two <span class="hlt">bright</span> modes coexisting in the same unit cell as opposed to <span class="hlt">bright</span>-dark modes. We present experimental verification of two <span class="hlt">bright</span> modes coupling for a terahertz EIT-MM in the context of numerical results and theoretical analysis based on a coupled Lorentz oscillator model. In addition, a hybrid variation of the EIT-MM is proposed and implemented numerically to dynamically tune the EIT window by incorporating photosensitive silicon pads in the split gap region of the resonators. As a result, this hybrid MM enables the active optical control of a transition from the on state (EIT mode) to the off state (dipole mode).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.loc.gov/pictures/collection/hh/item/in0159.sheet.00006a/','SCIGOV-HHH'); return false;" href="https://www.loc.gov/pictures/collection/hh/item/in0159.sheet.00006a/"><span><span class="hlt">Horizontal</span> Cross Bracing Detail, Vertical Cross Bracing Detail, <span class="hlt">Horizontal</span> Cross ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p><span class="hlt">Horizontal</span> Cross Bracing Detail, Vertical Cross Bracing Detail, <span class="hlt">Horizontal</span> Cross Bracing Joint, Vertical Cross Bracing End Detail - Ceylon Covered Bridge, Limberlost Park, spanning Wabash River at County Road 900 South, Geneva, Adams County, IN</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...808L..16A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...808L..16A"><span>Faint Luminescent Ring over Saturn’s <span class="hlt">Polar</span> Hexagon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adriani, Alberto; Moriconi, Maria Luisa; D'Aversa, Emiliano; Oliva, Fabrizio; Filacchione, Gianrico</p> <p>2015-07-01</p> <p>Springtime insolation is presently advancing across Saturn's north <span class="hlt">polar</span> region. Early solar radiation scattered through the gaseous giant's atmosphere gives a unique opportunity to sound the atmospheric structure at its upper troposphere/lower stratosphere at high latitudes. Here, we report the detection of a tenuous <span class="hlt">bright</span> structure in Saturn's northern <span class="hlt">polar</span> cap corresponding to the hexagon equatorward boundary, observed by Cassini Visual and Infrared Mapping Spectrometer on 2013 June. The structure is spectrally characterized by an anomalously enhanced intensity in the 3610-3730 nm wavelength range and near 2500 nm, pertaining to relatively low opacity windows between strong methane absorption bands. Our first results suggest that a strong forward scattering by tropospheric clouds, higher in respect to the surrounding cloud deck, can be responsible for the enhanced intensity of the feature. This can be consistent with the atmospheric dynamics associated with the jet stream embedded in the <span class="hlt">polar</span> hexagon. Further investigations at higher spectral resolution are needed to better assess the vertical distribution and microphysics of the clouds in this interesting region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003SPIE.5158...71Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003SPIE.5158...71Y"><span>Bio-inspired display of <span class="hlt">polarization</span> information using selected visual cues</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yemelyanov, Konstantin M.; Lin, Shih-Schon; Luis, William Q.; Pugh, Edward N., Jr.; Engheta, Nader</p> <p>2003-12-01</p> <p>For imaging systems the <span class="hlt">polarization</span> of electromagnetic waves carries much potentially useful information about such features of the world as the surface shape, material contents, local curvature of objects, as well as about the relative locations of the source, object and imaging system. The imaging system of the human eye however, is "<span class="hlt">polarization</span>-blind", and cannot utilize the <span class="hlt">polarization</span> of light without the aid of an artificial, <span class="hlt">polarization</span>-sensitive instrument. Therefore, <span class="hlt">polarization</span> information captured by a man-made polarimetric imaging system must be displayed to a human observer in the form of visual cues that are naturally processed by the human visual system, while essentially preserving the other important non-<span class="hlt">polarization</span> information (such as spectral and intensity information) in an image. In other words, some forms of sensory substitution are needed for representing <span class="hlt">polarization</span> "signals" without affecting other visual information such as color and <span class="hlt">brightness</span>. We are investigating several bio-inspired representational methodologies for mapping <span class="hlt">polarization</span> information into visual cues readily perceived by the human visual system, and determining which mappings are most suitable for specific applications such as object detection, navigation, sensing, scene classifications, and surface deformation. The visual cues and strategies we are exploring are the use of coherently moving dots superimposed on image to represent various range of <span class="hlt">polarization</span> signals, overlaying textures with spatial and/or temporal signatures to segregate regions of image with differing <span class="hlt">polarization</span>, modulating luminance and/or color contrast of scenes in terms of certain aspects of <span class="hlt">polarization</span> values, and fusing <span class="hlt">polarization</span> images into intensity-only images. In this talk, we will present samples of our findings in this area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160008397','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160008397"><span>Comparison of Areas in Shadow from Imaging and Altimetry in the North <span class="hlt">Polar</span> Region of Mercury and Implications for <span class="hlt">Polar</span> Ice Deposits</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deutsch, Ariel N.; Chabot, Nancy L.; Mazarico, Erwan; Ernst, Carolyn M.; Head, James W.; Neumann, Gregory A.; Solomon, Sean C.</p> <p>2016-01-01</p> <p>Earth-based radar observations and results from the MESSENGER mission have provided strong evidence that permanently shadowed regions near Mercury's poles host deposits of water ice. MESSENGER's complete orbital image and topographic datasets enable Mercury's surface to be observed and modeled under an extensive range of illumination conditions. The shadowed regions of Mercury's north <span class="hlt">polar</span> region from 65 deg N to 90 deg N were mapped by analyzing Mercury Dual Imaging System (MDIS) images and by modeling illumination with Mercury Laser Altimeter (MLA) topographic data. The two independent methods produced strong agreement in identifying shadowed areas. All large radar-<span class="hlt">bright</span> deposits, those hosted within impact craters greater than or equal to 6 km in diameter, collocate with regions of shadow identified by both methods. However, only approximately 46% of the persistently shadowed areas determined from images and approximately 43% of the permanently shadowed areas derived from altimetry host radar-<span class="hlt">bright</span> materials. Some sizable regions of shadow that do not host radar-<span class="hlt">bright</span> deposits experience thermal conditions similar to those that do. The shadowed craters that lack radar-<span class="hlt">bright</span> materials show a relation with longitude that is not related to the thermal environment, suggesting that the Earth-based radar observations of these locations may have been limited by viewing geometry, but it is also possible that water ice in these locations is insulated by anomalously thick lag deposits or that these shadowed regions do not host water ice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5761734','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5761734"><span>Comparison of areas in shadow from imaging and altimetry in the north <span class="hlt">polar</span> region of Mercury and implications for <span class="hlt">polar</span> ice deposits</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Deutsch, Ariel N.; Chabot, Nancy L.; Mazarico, Erwan; Ernst, Carolyn M.; Head, James W.; Neumann, Gregory A.; Solomon, Sean C.</p> <p>2017-01-01</p> <p>Earth-based radar observations and results from the MESSENGER mission have provided strong evidence that permanently shadowed regions near Mercury's poles host deposits of water ice. MESSENGER's complete orbital image and topographic datasets enable Mercury's surface to be observed and modeled under an extensive range of illumination conditions. The shadowed regions of Mercury's north <span class="hlt">polar</span> region from 65°N to 90°N were mapped by analyzing Mercury Dual Imaging System (MDIS) images and by modeling illumination with Mercury Laser Altimeter (MLA) topographic data. The two independent methods produced strong agreement in identifying shadowed areas. All large radar-<span class="hlt">bright</span> deposits, those hosted within impact craters ≥6 km in diameter, collocate with regions of shadow identified by both methods. However, only ∼46% of the persistently shadowed areas determined from images and ∼43% of the permanently shadowed areas derived from altimetry host radar-<span class="hlt">bright</span> materials. Some sizable regions of shadow that do not host radar-<span class="hlt">bright</span> deposits experience thermal conditions similar to those that do. The shadowed craters that lack radar-<span class="hlt">bright</span> materials show a relation with longitude that is not related to the thermal environment, suggesting that the Earth-based radar observations of these locations may have been limited by viewing geometry, but it is also possible that water ice in these locations is insulated by anomalously thick lag deposits or that these shadowed regions do not host water ice. PMID:29332948</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ApJ...855...92C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ApJ...855...92C"><span>ALMA’s <span class="hlt">Polarized</span> View of 10 Protostars in the Perseus Molecular Cloud</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cox, Erin G.; Harris, Robert J.; Looney, Leslie W.; Li, Zhi-Yun; Yang, Haifeng; Tobin, John J.; Stephens, Ian</p> <p>2018-03-01</p> <p>We present 870 μm ALMA dust <span class="hlt">polarization</span> observations of 10 young Class 0/I protostars in the Perseus Molecular Cloud. At ∼0.″35 (80 au) resolution, all of our sources show some degree of <span class="hlt">polarization</span>, with most (9/10) showing significantly extended emission in the <span class="hlt">polarized</span> continuum. Each source has incredibly intricate <span class="hlt">polarization</span> signatures. In particular, all three disk-candidates have <span class="hlt">polarization</span> vectors roughly along the minor axis, which is indicative of <span class="hlt">polarization</span> produced by dust scattering. On ∼100 au scales, the <span class="hlt">polarization</span> is at a relatively low level (≲1%) and is quite ordered. In sources with significant envelope emission, the envelope is typically <span class="hlt">polarized</span> at a much higher (≳5%) level and has a far more disordered morphology. We compute the cumulative probability distributions for both the small (disk-scale) and large (envelope-scale) <span class="hlt">polarization</span> percentage. We find that the two are intrinsically different, even after accounting for the different detection thresholds in the high/low surface <span class="hlt">brightness</span> regions. We perform Kolmogorov–Smirnov and Anderson–Darling tests on the distributions of angle offsets of the <span class="hlt">polarization</span> from the outflow axis. We find disk-candidate sources are different from the non-disk-candidate sources. We conclude that the <span class="hlt">polarization</span> on the 100 au scale is consistent with the signature of dust scattering for disk-candidates and that the <span class="hlt">polarization</span> on the envelope-scale in all sources may come from another mechanism, most likely magnetically aligned grains.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JQSRT.209...19E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JQSRT.209...19E"><span>IPRT <span class="hlt">polarized</span> radiative transfer model intercomparison project - Three-dimensional test cases (phase B)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Emde, Claudia; Barlakas, Vasileios; Cornet, Céline; Evans, Frank; Wang, Zhen; Labonotte, Laurent C.; Macke, Andreas; Mayer, Bernhard; Wendisch, Manfred</p> <p>2018-04-01</p> <p>Initially unpolarized solar radiation becomes <span class="hlt">polarized</span> by scattering in the Earth's atmosphere. In particular molecular scattering (Rayleigh scattering) <span class="hlt">polarizes</span> electromagnetic radiation, but also scattering of radiation at aerosols, cloud droplets (Mie scattering) and ice crystals <span class="hlt">polarizes</span>. Each atmospheric constituent produces a characteristic <span class="hlt">polarization</span> signal, thus spectro-polarimetric measurements are frequently employed for remote sensing of aerosol and cloud properties. Retrieval algorithms require efficient radiative transfer models. Usually, these apply the plane-parallel approximation (PPA), assuming that the atmosphere consists of <span class="hlt">horizontally</span> homogeneous layers. This allows to solve the vector radiative transfer equation (VRTE) efficiently. For remote sensing applications, the radiance is considered constant over the instantaneous field-of-view of the instrument and each sensor element is treated independently in plane-parallel approximation, neglecting <span class="hlt">horizontal</span> radiation transport between adjacent pixels (Independent Pixel Approximation, IPA). In order to estimate the errors due to the IPA approximation, three-dimensional (3D) vector radiative transfer models are required. So far, only a few such models exist. Therefore, the International <span class="hlt">Polarized</span> Radiative Transfer (IPRT) working group of the International Radiation Commission (IRC) has initiated a model intercomparison project in order to provide benchmark results for <span class="hlt">polarized</span> radiative transfer. The group has already performed an intercomparison for one-dimensional (1D) multi-layer test cases [phase A, 1]. This paper presents the continuation of the intercomparison project (phase B) for 2D and 3D test cases: a step cloud, a cubic cloud, and a more realistic scenario including a 3D cloud field generated by a Large Eddy Simulation (LES) model and typical background aerosols. The commonly established benchmark results for 3D <span class="hlt">polarized</span> radiative transfer are available at the IPRT website (http</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006DPS....38.6705B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006DPS....38.6705B"><span>Goldstone/VLA 3.5cm Mars Radar Observations - "Stealths" and South <span class="hlt">Polar</span> Regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Butler, Bryan; Chizek, M. R.; Slade, M. A.; Haldemann, A. F.; Muhleman, D. O.; Mao, T. F.</p> <p>2006-09-01</p> <p>The opposition of Mars in 2003 provided a fantastic opportunity to use the combined Goldstone/VLA radar to probe the surface with the highest resolution ever obtained on Mars with that instrument (as good as 70 km). Observations were made on August 11, 19, 28, and September 8. Details of data reduction and analysis of the radar echoes from the volcanic regions of the planet are presented in a companion paper in these proceedings (Chizek et al.). We will present results related to "Stealth" (and other radar-dark regions of the planet, including the Argyre and Hellas Planitiae, and a region to the west of the Elysium Mons caldera), and the south <span class="hlt">polar</span> residual and seasonal ice caps. The size, shape, and reflectivity characteristics of Stealth and "mega-Stealth" (Edgett et al. 1997) are reaffirmed, with a better viewing geometry of the western extent of the feature than had been obtained previously. It had been speculated previously that Hellas Planitia should also be radar dark - this is confirmed by our imaging, though the reflectivity is not as low as for Stealth. We find a new radar dark area to the west of Elysium Mons, which is likely an ash fall from that volcano (similar to the relationship between Stealth and the Tharsis volcanoes). The south <span class="hlt">polar</span> residual ice cap is a very <span class="hlt">bright</span> reflector, as seen previously, but we now also see a very <span class="hlt">bright</span> reflection from the seasonal cap, not seen previously. The cap is not uniformly <span class="hlt">bright</span>, however, and the extent of the <span class="hlt">bright</span> reflection does not correspond to that expected from the retreat of the cap as measured either from albedo or thermal emission characteristics. The NRAO is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JQSRT.189..149K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JQSRT.189..149K"><span>Canopy <span class="hlt">polarized</span> BRDF simulation based on non-stationary Monte Carlo 3-D vector RT modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kallel, Abdelaziz; Gastellu-Etchegorry, Jean Philippe</p> <p>2017-03-01</p> <p>Vector radiative transfer (VRT) has been largely used to simulate <span class="hlt">polarized</span> reflectance of atmosphere and ocean. However it is still not properly used to describe vegetation cover <span class="hlt">polarized</span> reflectance. In this study, we try to propose a 3-D VRT model based on a modified Monte Carlo (MC) forward ray tracing simulation to analyze vegetation canopy reflectance. Two kinds of leaf scattering are taken into account: (i) Lambertian diffuse reflectance and transmittance and (ii) specular reflection. A new method to estimate the condition on leaf orientation to produce reflection is proposed, and its probability to occur, Pl,max, is computed. It is then shown that Pl,max is low, but when reflection happens, the corresponding radiance Stokes vector, Io, is very high. Such a phenomenon dramatically increases the MC variance and yields to an irregular reflectance distribution function. For better regularization, we propose a non-stationary MC approach that simulates reflection for each sunny leaf assuming that its orientation is randomly chosen according to its angular distribution. It is shown in this case that the average canopy reflection is proportional to Pl,max ·Io which produces a smooth distribution. Two experiments are conducted: (i) assuming leaf light <span class="hlt">polarization</span> is only due to the Fresnel reflection and (ii) the general <span class="hlt">polarization</span> case. In the former experiment, our results confirm that in the forward direction, canopy <span class="hlt">polarizes</span> <span class="hlt">horizontally</span> light. In addition, they show that in inclined forward direction, diagonal <span class="hlt">polarization</span> can be observed. In the latter experiment, <span class="hlt">polarization</span> is produced in all orientations. It is particularly pointed out that specular <span class="hlt">polarization</span> explains just a part of the forward <span class="hlt">polarization</span>. Diffuse scattering <span class="hlt">polarizes</span> light <span class="hlt">horizontally</span> and vertically in forward and backward directions, respectively. Weak circular <span class="hlt">polarization</span> signal is also observed near the backscattering direction. Finally, validation of the non-<span class="hlt">polarized</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007Icar..191...52P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007Icar..191...52P"><span>Thermal behavior of <span class="hlt">horizontally</span> mixed surfaces on Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Putzig, Nathaniel E.; Mellon, Michael T.</p> <p>2007-11-01</p> <p>Current methods for deriving thermal inertia from spacecraft observations of planetary <span class="hlt">brightness</span> temperature generally assume that surface properties are uniform for any given observation or co-located set of observations. As a result of this assumption and the nonlinear relationship between temperature and thermal inertia, sub-pixel <span class="hlt">horizontal</span> heterogeneity may yield different apparent thermal inertia at different times of day or seasons. We examine the effects of <span class="hlt">horizontal</span> heterogeneity on Mars by modeling the thermal behavior of various idealized mixed surfaces containing differing proportions of either dust, sand, duricrust, and rock or slope facets at different angles and azimuths. Latitudinal effects on mixed-surface thermal behavior are also investigated. We find large (several 100 J m -2 K -1 s -1/2) diurnal and seasonal variations in apparent thermal inertia even for small (˜10%) admixtures of materials with moderately contrasting thermal properties or slope angles. Together with similar results for layered surfaces [Mellon, M.T., Putzig, N.E., 2007. Lunar Planet. Sci. XXXVIII. Abstract 2184], this work shows that the effects of heterogeneity on the thermal behavior of the martian surface are substantial and may be expected to result in large variations in apparent thermal inertia as derived from spacecraft instruments. While our results caution against the over-interpretation of thermal inertia taken from median or average maps or derived from single temperature measurements, they also suggest the possibility of using a suite of apparent thermal inertia values derived from single observations over a range of times of day and seasons to constrain the heterogeneity of the martian surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970022610','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970022610"><span>New Observations of Subarcsecond Photospheric <span class="hlt">Bright</span> Points</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Berger, T. E.; Schrijver, C. J.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Scharmer, G.</p> <p>1995-01-01</p> <p>We have used an interference filter centered at 4305 A within the bandhead of the CH radical (the 'G band') and real-time image selection at the Swedish Vacuum Solar Telescope on La Palma to produce very high contrast images of subarcsecond photospheric <span class="hlt">bright</span> points at all locations on the solar disk. During the 6 day period of 1993 September 15-20 we observed active region NOAA 7581 from its appearance on the East limb to a near-disk-center position on September 20. A total of 1804 <span class="hlt">bright</span> points were selected for analysis from the disk center image using feature extraction image processing techniques. The measured Full Width at Half Maximum (FWHM) distribution of the <span class="hlt">bright</span> points in the image is lognormal with a modal value of 220 km (0 sec .30) and an average value of 250 km (0 sec .35). The smallest measured <span class="hlt">bright</span> point diameter is 120 km (0 sec .17) and the largest is 600 km (O sec .69). Approximately 60% of the measured <span class="hlt">bright</span> points are circular (eccentricity approx. 1.0), the average eccentricity is 1.5, and the maximum eccentricity corresponding to filigree in the image is 6.5. The peak contrast of the measured <span class="hlt">bright</span> points is normally distributed. The contrast distribution variance is much greater than the measurement accuracy, indicating a large spread in intrinsic <span class="hlt">bright</span>-point contrast. When referenced to an averaged 'quiet-Sun' area in the image, the modal contrast is 29% and the maximum value is 75%; when referenced to an average intergranular lane <span class="hlt">brightness</span> in the image, the distribution has a modal value of 61% and a maximum of 119%. The bin-averaged contrast of G-band <span class="hlt">bright</span> points is constant across the entire measured size range. The measured area of the <span class="hlt">bright</span> points, corrected for pixelation and selection effects, covers about 1.8% of the total image area. Large pores and micropores occupy an additional 2% of the image area, implying a total area fraction of magnetic proxy features in the image of 3.8%. We discuss the implications of this</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970023731','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970023731"><span>New Observations of Subarcsecond Photospheric <span class="hlt">Bright</span> Points</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Berger, T. E.; Schrijver, C. J.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Scharmer, G.</p> <p>1995-01-01</p> <p>We have used an interference filter centered at 4305 A within the bandhead of the CH radical (the 'G band') and real-time image selection at the Swedish Vacuum Solar Telescope on La Palma to produce very high contrast images of subarcsecond photospheric <span class="hlt">bright</span> points at all locations on the solar disk. During the 6 day period of 15-20 Sept. 1993 we observed active region NOAA 7581 from its appearance on the East limb to a near-disk-center position on 20 Sept. A total of 1804 <span class="hlt">bright</span> points were selected for analysis from the disk center image using feature extraction image processing techniques. The measured FWHM distribution of the <span class="hlt">bright</span> points in the image is lognormal with a modal value of 220 km (0.30 sec) and an average value of 250 km (0.35 sec). The smallest measured <span class="hlt">bright</span> point diameter is 120 km (0.17 sec) and the largest is 600 km (O.69 sec). Approximately 60% of the measured <span class="hlt">bright</span> points are circular (eccentricity approx. 1.0), the average eccentricity is 1.5, and the maximum eccentricity corresponding to filigree in the image is 6.5. The peak contrast of the measured <span class="hlt">bright</span> points is normally distributed. The contrast distribution variance is much greater than the measurement accuracy, indicating a large spread in intrinsic <span class="hlt">bright</span>-point contrast. When referenced to an averaged 'quiet-Sun' area in the image, the modal contrast is 29% and the maximum value is 75%; when referenced to an average intergranular lane <span class="hlt">brightness</span> in the image, the distribution has a modal value of 61% and a maximum of 119%. The bin-averaged contrast of G-band <span class="hlt">bright</span> points is constant across the entire measured size range. The measured area of the <span class="hlt">bright</span> points, corrected for pixelation and selection effects, covers about 1.8% of the total image area. Large pores and micropores occupy an additional 2% of the image area, implying a total area fraction of magnetic proxy features in the image of 3.8%. We discuss the implications of this area fraction measurement in the context of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009914','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009914"><span>Thermal Stability of Frozen Volatiles in the North <span class="hlt">Polar</span> Region of Mercury</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Paige, David A.; Siegler, Matthew A.; Harmon, John K.; Smith, David E.; Zuber, Maria T.; Neumann, Gregory A.; Solomon, Sean C.</p> <p>2012-01-01</p> <p>Earth-based radar observations have revealed the presence on Mercury of anomalously <span class="hlt">bright</span>, depolarizing features that appear to be localized in the permanently shadowed regions of high-latitude impact craters [1]. Observations of similar radar signatures over a range of radar wavelengths implies that they correspond to deposits that are highly transparent at radar wavelengths and extend to depths of several meters below the surface [1]. Thermal models using idealized crater topographic profiles have predicted the thermal stability of surface and subsurface water ice at these same latitudes [2]. One of the major goals of the MESSENGER mission is to characterize the nature of radar-<span class="hlt">bright</span> craters and presumed associated frozen volatile deposits at the poles of Mercury through complementary orbital observations by a suite of instruments [3]. Here we report on an examination of the thermal stability of water ice and other frozen volatiles in the north <span class="hlt">polar</span> region of Mercury using topographic profiles obtained by the Mercury Laser Altimeter (MLA) instrument [4] in conjunction with a three-dimensional ray-tracing thermal model previously used to study the thermal environment of <span class="hlt">polar</span> craters on the Moon [5].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011EPJD...64..103G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011EPJD...64..103G"><span>Subwavelength dark hollow focus of spirally <span class="hlt">polarized</span> axisymmetric Bessel-modulated Gaussian beam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, X. M.; Zhan, Q. F.; Wang, Q.; Yun, M. J.; Guo, H. M.; Zhuang, S. L.</p> <p>2011-09-01</p> <p>Dark hollow focus plays an important role in many optical systems. In this paper, dark hollow focal shaping of spirally <span class="hlt">polarized</span> axisymmetric Bessel-modulated Gaussian beam is investigated by vector diffraction theory in detail. Results show that the dark hollow focus can be altered considerably by beam parameter and spiral parameter that indicates <span class="hlt">polarization</span> spiral degree. One dark hollow focus and two dark hollow foci pattern may occur for certain spiral parameter, and the transverse size of dark hollow focus can be less than the diffraction limit size of <span class="hlt">bright</span> focus. In addition, there may also appear two triangle dark hollow foci that are connected by one dark line focus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870014106','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870014106"><span>Stratigraphy of the south <span class="hlt">polar</span> region of Ganymede</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dehon, R. A.</p> <p>1987-01-01</p> <p>A preliminary assessment is made of the stratigraphy and geology in the south <span class="hlt">polar</span> region of the Jovian satellite, Ganymede. Geologic mapping is based on inspection of Voyager images and compilation on an airbrush base map at a scale of 1:5M. Illumination and resolution vary greatly in the region. Approximately half of the quadripole is beyond the terminator. Low angle illumination over a large part of the area precludes distinction of some units by albedo characteristics. Several types of grooved terrain and groove related terrain occur in the southern <span class="hlt">polar</span> region. Grooves typically occur in straight to curvilinear sets or lanes. <span class="hlt">Bright</span> lanes and grooved lanes intersect at high angles outlining polygons of dark cratered terrain. Groove sets exhibit a range of ages as shown by superposition or truncation and by crater superposition ages.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ACP....18..883R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ACP....18..883R"><span>Universal power law of the gravity wave manifestation in the AIM CIPS <span class="hlt">polar</span> mesospheric cloud images</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rong, Pingping; Yue, Jia; Russell, James M., III; Siskind, David E.; Randall, Cora E.</p> <p>2018-01-01</p> <p>We aim to extract a universal law that governs the gravity wave manifestation in <span class="hlt">polar</span> mesospheric clouds (PMCs). Gravity wave morphology and the clarity level of display vary throughout the wave population manifested by the PMC albedo data. Higher clarity refers to more distinct exhibition of the features, which often correspond to larger variances and a better-organized nature. A gravity wave tracking algorithm based on the continuous Morlet wavelet transform is applied to the PMC albedo data at 83 km altitude taken by the Aeronomy of Ice in the Mesosphere (AIM) Cloud Imaging and Particle Size (CIPS) instrument to obtain a large ensemble of the gravity wave detections. The <span class="hlt">horizontal</span> wavelengths in the range of ˜ 20-60 km are the focus of the study. It shows that the albedo (wave) power statistically increases as the background gets brighter. We resample the wave detections to conform to a normal distribution to examine the wave morphology and display clarity beyond the cloud <span class="hlt">brightness</span> impact. Sample cases are selected at the two tails and the peak of the normal distribution to represent the full set of wave detections. For these cases the albedo power spectra follow exponential decay toward smaller scales. The high-albedo-power category has the most rapid decay (i.e., exponent = -3.2) and corresponds to the most distinct wave display. The wave display becomes increasingly blurrier for the medium- and low-power categories, which hold the monotonically decreasing spectral exponents of -2.9 and -2.5, respectively. The majority of waves are straight waves whose clarity levels can collapse between the different <span class="hlt">brightness</span> levels, but in the brighter background the wave signatures seem to exhibit mildly turbulent-like behavior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060053989&hterms=leaves&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dleaves','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060053989&hterms=leaves&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dleaves"><span><span class="hlt">Polarization</span> of Light by Leaves and Plant Canopies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vanderbilt, V. C.</p> <p>2006-01-01</p> <p>This talk will focus first on the information contained in the surface-scattered light from leaves, plant canopies and surface waters. This light is in general <span class="hlt">polarized</span> and depends upon surface roughness. Thus, for example, - The surface reflection from shiny green leaves measured in the specular direction shows no chlorophyll absorption bands, no 'red edge.' - Conversely, the degree of linear <span class="hlt">polarization</span> of such light displays marked variation with wavelength having local maxima in the chlorophyll absorption bands and an inverted red edge. - Plant canopies with shiny leaves distributed in angle like the area on a sphere, specularly reflect sunlight in the subsolar or specular direction- but also in every other view direction. - Canopies of green plants may appear white not green when viewed obliquely toward the sun. - In a light to moderate wind, the often blindingly <span class="hlt">bright</span> glitter of sunlight off smooth water surfaces provides a strong, angularly narrow signature reflection characteristic of inundated vegetated areas that are big sources of atmospheric methane, a climatically important greenhouse gas. (Conversely, a blindingly <span class="hlt">bright</span> glitter-type reflection is uncharacteristic of upland or wind ruffled open water areas that are poor sources of atmospheric methane.) Because some of these results may be 'head scratchers,' it's always important to properly calibrate ones instruments. Indeed, as the second portion of the talk will show, the characteristics of the light measuring instrument, particularly its entrance aperture, may affect the results and should be taken into account during across-instrument data comparisons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22365802-larger-planet-radii-inferred-from-stellar-flicker-brightness-variations-bright-planet-host-stars','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22365802-larger-planet-radii-inferred-from-stellar-flicker-brightness-variations-bright-planet-host-stars"><span>LARGER PLANET RADII INFERRED FROM STELLAR ''FLICKER'' <span class="hlt">BRIGHTNESS</span> VARIATIONS OF <span class="hlt">BRIGHT</span> PLANET-HOST STARS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Bastien, Fabienne A.; Stassun, Keivan G.; Pepper, Joshua</p> <p>2014-06-10</p> <p>Most extrasolar planets have been detected by their influence on their parent star, typically either gravitationally (the Doppler method) or by the small dip in <span class="hlt">brightness</span> as the planet blocks a portion of the star (the transit method). Therefore, the accuracy with which we know the masses and radii of extrasolar planets depends directly on how well we know those of the stars, the latter usually determined from the measured stellar surface gravity, log g. Recent work has demonstrated that the short-timescale <span class="hlt">brightness</span> variations ({sup f}licker{sup )} of stars can be used to measure log g to a high accuracymore » of ∼0.1-0.2 dex. Here, we use flicker measurements of 289 <span class="hlt">bright</span> (Kepmag < 13) candidate planet-hosting stars with T {sub eff} = 4500-6650 K to re-assess the stellar parameters and determine the resulting impact on derived planet properties. This re-assessment reveals that for the brightest planet-host stars, Malmquist bias contaminates the stellar sample with evolved stars: nearly 50% of the <span class="hlt">bright</span> planet-host stars are subgiants. As a result, the stellar radii, and hence the radii of the planets orbiting these stars, are on average 20%-30% larger than previous measurements had suggested.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011LPI....42.2252B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011LPI....42.2252B"><span>Modeling the Formation of CO2 Frost Halos on the South <span class="hlt">Polar</span> Residual Cap of Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Becerra, P.; Byrne, S.; HiRISE Team</p> <p>2011-03-01</p> <p>We introduce a model for the formation of <span class="hlt">bright</span> halos seen by HiRISE on the edges of scarps and "swiss cheese" features in the south <span class="hlt">polar</span> residual cap of Mars. We propose that they are formed from differences between the sublimation rates of sloped and flat surfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...835..275R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...835..275R"><span>Flux and <span class="hlt">Polarization</span> Variability of OJ 287 during the Early 2016 Outburst</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rakshit, Suvendu; Stalin, C. S.; Muneer, S.; Neha, S.; Paliya, Vaidehi S.</p> <p>2017-02-01</p> <p>The gamma-ray blazar OJ 287 was in a high activity state during 2015 December-2016 February. Coinciding with this high <span class="hlt">brightness</span> state, we observed this source for photometry on 40 nights in R-band and for polarimetry on nine epochs in UBV RI bands. During the period of our observations, the source <span class="hlt">brightness</span> varied from 13.20 ± 0.04 mag to 14.98 ± 0.04 mag and the degree of <span class="hlt">polarization</span> (P) fluctuated between 6.0% ± 0.3% and 28.3% ± 0.8% in R-band. Focusing on intranight optical variability (INOV), we find a duty cycle of about 71% using χ2-statistics, similar to that known for blazars. From INOV data, the shortest variability timescale is estimated to be 142 ± 38 minutes, yielding a lower limit of the observed Doppler factor δ0 = 1.17, the magnetic field strength B ≤ 3.8 G, and the size of the emitting region Rs < 2.28 × 1014 cm. On internight timescales, a significant anticorrelation between R-band flux and P is found. The observed P at U-band is generally larger than that observed at longer-wavelength bands, suggesting a wavelength-dependent <span class="hlt">polarization</span>. Using V-band photometric and polarimetric data from Steward Observatory obtained during our monitoring period, we find a varied correlation between P and V-band <span class="hlt">brightness</span>. While an anticorrelation is sometimes seen between P and V-band magnitude, no correlation is seen at other times, thereby suggesting the presence of more than one short-lived shock component in the jet of OJ 287.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AAS...21330108M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AAS...21330108M"><span>Network based sky <span class="hlt">Brightness</span> Monitor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McKenna, Dan; Pulvermacher, R.; Davis, D. R.</p> <p>2009-01-01</p> <p>We have developed and are currently testing an autonomous 2 channel photometer designed to measure the night sky <span class="hlt">brightness</span> in the visual wavelengths over a multi-year campaign. The photometer uses a robust silicon sensor filtered with Hoya CM500 glass. The Sky <span class="hlt">brightness</span> is measured every minute at two elevation angles typically zenith and 20 degrees to monitor <span class="hlt">brightness</span> and transparency. The Sky <span class="hlt">Brightness</span> monitor consists of two units, the remote photometer and a network interface. Currently these devices use 2.4 Ghz transceivers with a free space range of 100 meters. The remote unit is battery powered with day time recharging using a solar panel. Data received by the network interface transmits data via standard POP Email protocol. A second version is under development for radio sensitive areas using an optical fiber for data transmission. We will present the current comparison with the National Park Service sky monitoring camera. We will also discuss the calibration methods used for standardization and temperature compensation. This system is expected to be deployed in the next year and be operated by the International Dark Sky Association SKYMONITOR project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24076544','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24076544"><span><span class="hlt">Bright</span> light induces choroidal thickening in chickens.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lan, Weizhong; Feldkaemper, Marita; Schaeffel, Frank</p> <p>2013-11-01</p> <p><span class="hlt">Bright</span> light is a potent inhibitor of myopia development in animal models. Because development of refractive errors has been linked to changes in choroidal thickness, we have studied in chickens whether <span class="hlt">bright</span> light may exert its effects on myopia also through changes in choroidal thickness. Three-day-old chickens were exposed to "<span class="hlt">bright</span> light" (15,000 lux; n = 14) from 10 AM to 4 PM but kept under "normal light" (500 lux) during the remaining time of the light phase for 5 days (total duration of light phase 8 AM to 6 PM). A control group (n = 14) was kept under normal light during the entire light phase. Choroidal thickness was measured in alert, hand-held animals with optical coherence tomography at 10 AM, 4 PM, and 8 PM every day. Complete data sets were available for 12 chicks in <span class="hlt">bright</span> light group and nine in normal light group. The striking inter-individual variability in choroidal thickness (coefficient of variance: 23%) made it necessary to normalize changes to the individual baseline thickness of the choroid. During the 6 hours of exposure to <span class="hlt">bright</span> light, choroidal thickness decreased by -5.2 ± 4.0% (mean ± SEM). By contrast, in the group kept under normal light, choroidal thickness increased by +15.4 ± 4.7% (difference between both groups p = 0.003). After an additional 4 hours, choroidal thickness increased also in the "<span class="hlt">bright</span> light group" by +17.8 ± 3.5%, while there was little further change (+0.6 ± 4.0%) in the "normal light group" (difference p = 0.004). Finally, the choroid was thicker in the "<span class="hlt">bright</span> light group" (+7.6 ± 26.0%) than in the "normal light group" (day 5: -18.6 ± 26.9%; difference p = 0.036). <span class="hlt">Bright</span> light stimulates choroidal thickening in chickens, although the response is smaller than with experimentally imposed myopic defocus, and it occurs with some time delay. It nevertheless suggests that choroidal thickening is also involved in myopia inhibition by <span class="hlt">bright</span> light.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22663516-sub-band-fluxes-polarization-starlight-reflected-earth-like-exoplanets','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22663516-sub-band-fluxes-polarization-starlight-reflected-earth-like-exoplanets"><span>The O{sub 2} A-Band in the Fluxes and <span class="hlt">Polarization</span> of Starlight Reflected by Earth-Like Exoplanets</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Fauchez, Thomas; Rossi, Loic; Stam, Daphne M.</p> <p></p> <p>Earth-like, potentially habitable exoplanets are prime targets in the search for extraterrestrial life. Information about their atmospheres and surfaces can be derived by analyzing the light of the parent star reflected by the planet. We investigate the influence of the surface albedo A {sub s}, the optical thickness b {sub cloud}, the altitude of water clouds, and the mixing ratio of biosignature O{sub 2} on the strength of the O{sub 2} A-band (around 760 nm) in the flux and <span class="hlt">polarization</span> spectra of starlight reflected by Earth-like exoplanets. Our computations for <span class="hlt">horizontally</span> homogeneous planets show that small mixing ratios ( ηmore » < 0.4) will yield moderately deep bands in flux and moderate-to-small band strengths in <span class="hlt">polarization</span>, and that clouds will usually decrease the band depth in flux and the band strength in <span class="hlt">polarization</span>. However, cloud influence will be strongly dependent on properties such as optical thickness, top altitude, particle phase, coverage fraction, and <span class="hlt">horizontal</span> distribution. Depending on the surface albedo and cloud properties, different O{sub 2} mixing ratios η can give similar absorption-band depths in flux and band strengths in <span class="hlt">polarization</span>, especially if the clouds have moderate-to-high optical thicknesses. Measuring both the flux and the <span class="hlt">polarization</span> is essential to reduce the degeneracies, although it will not solve them, especially not for <span class="hlt">horizontally</span> inhomogeneous planets. Observations at a wide range of phase angles and with a high temporal resolution could help to derive cloud properties and, once those are known, the mixing ratio of O{sub 2} or any other absorbing gas.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29895755','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29895755"><span>Piezo-Potential Generation in Capacitive Flexible Sensors Based on GaN <span class="hlt">Horizontal</span> Wires.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>El Kacimi, Amine; Pauliac-Vaujour, Emmanuelle; Delléa, Olivier; Eymery, Joël</p> <p>2018-06-12</p> <p>We report an example of the realization of a flexible capacitive piezoelectric sensor based on the assembly of <span class="hlt">horizontal</span> c¯-<span class="hlt">polar</span> long Gallium nitride (GaN) wires grown by metal organic vapour phase epitaxy (MOVPE) with the Boostream ® technique spreading wires on a moving liquid before their transfer on large areas. The measured signal (<0.6 V) obtained by a punctual compression/release of the device shows a large variability attributed to the dimensions of the wires and their in-plane orientations. The cause of this variability and the general operating mechanisms of this flexible capacitive device are explained by finite element modelling simulations. This method allows considering the full device composed of a metal/dielectric/wires/dielectric/metal stacking. We first clarify the mechanisms involved in the piezo-potential generation by mapping the charge and piezo-potential in a single wire and studying the time-dependent evolution of this phenomenon. GaN wires have equivalent dipoles that generate a tension between metallic electrodes only when they have a non-zero in-plane projection. This is obtained in practice by the conical shape occurring spontaneously during the MOVPE growth. The optimal aspect ratio in terms of length and conicity (for the usual MOVPE wire diameter) is determined for a bending mechanical loading. It is suggested to use 60⁻120 µm long wires (i.e., growth time less than 1 h). To study further the role of these dipoles, we consider model systems with in-plane 1D and 2D regular arrays of <span class="hlt">horizontal</span> wires. It is shown that a strong electrostatic coupling and screening occur between neighbouring <span class="hlt">horizontal</span> wires depending on <span class="hlt">polarity</span> and shape. This effect, highlighted here only from calculations, should be taken into account to improve device performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995AJ....110..573M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995AJ....110..573M"><span>Galaxy Selection and the Surface <span class="hlt">Brightness</span> Distribution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McGaugh, Stacy S.; Bothun, Gregory D.; Schombert, James M.</p> <p>1995-08-01</p> <p>Optical surveys for galaxies are biased against the inclusion of low surface <span class="hlt">brightness</span> (LSB) galaxies. Disney [Nature, 263,573(1976)] suggested that the constancy of disk central surface <span class="hlt">brightness</span> noticed by Freeman [ApJ, 160,811(1970)] was not a physical result, but instead was an artifact of sample selection. Since LSB galaxies do exist, the pertinent and still controversial issue is if these newly discovered galaxies constitute a significant percentage of the general galaxy population. In this paper, we address this issue by determining the space density of galaxies as a function of disk central surface <span class="hlt">brightness</span>. Using the physically reasonable assumption (which is motivated by the data) that central surface <span class="hlt">brightness</span> is independent of disk scale length, we arrive at a distribution which is roughly flat (i.e., approximately equal numbers of galaxies at each surface <span class="hlt">brightness</span>) faintwards of the Freeman (1970) value. Brightwards of this, we find a sharp decline in the distribution which is analogous to the turn down in the luminosity function at L^*^. An intrinsically sharply peaked "Freeman law" distribution can be completely ruled out, and no Gaussian distribution can fit the data. Low surface <span class="hlt">brightness</span> galaxies (those with central surface <span class="hlt">brightness</span> fainter than 22 B mag arcsec^-2^) comprise >~ 1/2 the general galaxy population, so a representative sample of galaxies at z = 0 does not really exist at present since past surveys have been insensitive to this component of the general galaxy population.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3152653','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3152653"><span>Spatiotemporal analysis of <span class="hlt">brightness</span> induction</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>McCourt, Mark E.</p> <p>2011-01-01</p> <p><span class="hlt">Brightness</span> induction refers to a class of visual illusions in which the perceived intensity of a region of space is influenced by the luminance of surrounding regions. These illusions are significant because they provide insight into the neural organization of the visual system. A novel quadrature-phase motion cancelation technique was developed to measure the magnitude of the grating induction <span class="hlt">brightness</span> illusion across a wide range of spatial frequencies, temporal frequencies and test field heights. Canceling contrast is greatest at low frequencies and declines with increasing frequency in both dimensions, and with increasing test field height. Canceling contrast scales as the product of inducing grating spatial frequency and test field height (the number of inducing grating cycles per test field height). When plotted using a spatial axis which indexes this product, the spatiotemporal induction surfaces for four test field heights can be described as four partially overlapping sections of a single larger surface. These properties of <span class="hlt">brightness</span> induction are explained in the context of multiscale spatial filtering. The present study is the first to measure the magnitude of grating induction as a function of temporal frequency. Taken in conjunction with several other studies (Blakeslee & McCourt, 2008; Robinson & de Sa, 2008; Magnussen & Glad, 1975) the results of this study illustrate that at least one form of <span class="hlt">brightness</span> induction is very much faster than that reported by DeValois et al. (1986) and Rossi and Paradiso (1996), and are inconsistent with the proposition that <span class="hlt">brightness</span> induction results from a slow “filling in” process. PMID:21763339</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22564663','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22564663"><span>How can horseflies be captured by solar panels? A new concept of tabanid traps using light <span class="hlt">polarization</span> and electricity produced by photovoltaics.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Blahó, Miklós; Egri, Ádám; Barta, András; Antoni, Györgyi; Kriska, György; Horváth, Gábor</p> <p>2012-10-26</p> <p>Horseflies (Diptera: Tabanidae) can cause severe problems for humans and livestock because of the continuous annoyance performed and the diseases vectored by the haematophagous females. Therefore, effective horsefly traps are in large demand, especially for stock-breeders. To catch horseflies, several kinds of traps have been developed, many of them attracting these insects visually with the aid of a black ball. The recently discovered positive polarotaxis (attraction to <span class="hlt">horizontally</span> <span class="hlt">polarized</span> light) in several horsefly species can be used to design traps that capture female and male horseflies. The aim of this work is to present the concept of such a trap based on two novel principles: (1) the visual target of the trap is a <span class="hlt">horizontal</span> solar panel (photovoltaics) attracting polarotactic horseflies by means of the highly and <span class="hlt">horizontally</span> <span class="hlt">polarized</span> light reflected from the photovoltaic surface. (2) The horseflies trying to touch or land on the photovoltaic trap surface are perished by the mechanical hit of a wire rotated quickly with an electromotor supplied by the photovoltaics-produced electricity. Thus, the photovoltaics is bifunctional: its <span class="hlt">horizontally</span> <span class="hlt">polarized</span> reflected light signal attracts water-seeking, polarotactic horseflies, and it produces the electricity necessary to rotate the wire. We describe here the concept and design of this new horsefly trap, the effectiveness of which was demonstrated in field experiments. The advantages and disadvantages of the trap are discussed. Using imaging polarimetry, we measured the reflection-<span class="hlt">polarization</span> characteristics of the photovoltaic trap surface demonstrating the optical reason for the polarotactic attractiveness to horseflies. Copyright © 2012 Elsevier B.V. All rights reserved.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MNRAS.468.3024M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MNRAS.468.3024M"><span>Testing the existence of optical linear <span class="hlt">polarization</span> in young brown dwarfs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Manjavacas, E.; Miles-Páez, P. A.; Zapatero-Osorio, M. R.; Goldman, B.; Buenzli, E.; Henning, T.; Pallé, E.; Fang, M.</p> <p>2017-07-01</p> <p>Linear <span class="hlt">polarization</span> can be used as a probe of the existence of atmospheric condensates in ultracool dwarfs. Models predict that the observed linear <span class="hlt">polarization</span> increases with the degree of oblateness, which is inversely proportional to the surface gravity. We aimed to test the existence of optical linear <span class="hlt">polarization</span> in a sample of <span class="hlt">bright</span> young brown dwarfs, with spectral types between M6 and L2, observable from the Calar Alto Observatory, and cataloged previously as low gravity objects using spectroscopy. Linear polarimetric images were collected in I and R band using CAFOS at the 2.2-m telescope in Calar Alto Observatory (Spain). The flux ratio method was employed to determine the linear <span class="hlt">polarization</span> degrees. With a confidence of 3σ, our data indicate that all targets have a linear polarimetry degree in average below 0.69 per cent in the I band, and below 1.0 per cent in the R band, at the time they were observed. We detected significant (I.e. P/σ ≥ 3) linear <span class="hlt">polarization</span> for the young M6 dwarf 2MASS J04221413+1530525 in the R band, with a degree of p* = 0.81 ± 0.17 per cent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013RScI...84h3703N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013RScI...84h3703N"><span>A <span class="hlt">brightness</span> exceeding simulated Langmuir limit</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakasuji, Mamoru</p> <p>2013-08-01</p> <p>When an excitation of the first lens determines a beam is parallel beam, a <span class="hlt">brightness</span> that is 100 times higher than Langmuir limit is measured experimentally, where Langmuir limits are estimated using a simulated axial cathode current density which is simulated based on a measured emission current. The measured <span class="hlt">brightness</span> is comparable to Langmuir limit, when the lens excitation is such that an image position is slightly shorter than a lens position. Previously measured values of <span class="hlt">brightness</span> for cathode apical radii of curvature 20, 60, 120, 240, and 480 μm were 8.7, 5.3, 3.3, 2.4, and 3.9 times higher than their corresponding Langmuir limits, respectively, in this experiment, the lens excitation was such that the lens and the image positions were 180 mm and 400 mm, respectively. From these measured <span class="hlt">brightness</span> for three different lens excitation conditions, it is concluded that the <span class="hlt">brightness</span> depends on the first lens excitation. For the electron gun operated in a space charge limited condition, some of the electrons emitted from the cathode are returned to the cathode without having crossed a virtual cathode. Therefore, method that assumes a Langmuir limit defining method using a Maxwellian distribution of electron velocities may need to be revised. For the condition in which the values of the exceeding the Langmuir limit are measured, the simulated trajectories of electrons that are emitted from the cathode do not cross the optical axis at the crossover, thus the law of sines may not be valid for high <span class="hlt">brightness</span> electron beam systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070034151','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070034151"><span>Thin Sea-Ice Thickness as Inferred from Passive Microwave and In Situ Observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Naoki, Kazuhiro; Ukita, Jinro; Nishio, Fumihiko; Nakayama, Masashige; Comiso, Josefino C.; Gasiewski, Al</p> <p>2007-01-01</p> <p>Since microwave radiometric signals from sea-ice strongly reflect physical conditions of a layer near the ice surface, a relationship of <span class="hlt">brightness</span> temperature with thickness is possible especially during the early stages of ice growth. Sea ice is most saline during formation stage and as the salinity decreases with time while at the same time the thickness of the sea ice increases, a corresponding change in the dielectric properties and hence the <span class="hlt">brightness</span> temperature may occur. This study examines the extent to which the relationships of thickness with <span class="hlt">brightness</span> temperature (and with emissivity) hold for thin sea-ice, approximately less than 0.2 -0.3 m, using near concurrent measurements of sea-ice thickness in the Sea of Okhotsk from a ship and passive microwave <span class="hlt">brightness</span> temperature data from an over-flying aircraft. The results show that the <span class="hlt">brightness</span> temperature and emissivity increase with ice thickness for the frequency range of 10-37 GHz. The relationship is more pronounced at lower frequencies and at the <span class="hlt">horizontal</span> <span class="hlt">polarization</span>. We also established an empirical relationship between ice thickness and salinity in the layer near the ice surface from a field experiment, which qualitatively support the idea that changes in the near-surface brine characteristics contribute to the observed thickness-<span class="hlt">brightness</span> temperature/emissivity relationship. Our results suggest that for thin ice, passive microwave radiometric signals contain, ice thickness information which can be utilized in <span class="hlt">polar</span> process studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SPIE.8566E..05B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SPIE.8566E..05B"><span><span class="hlt">Polarization</span> sensitive camera for the in vitro diagnostic and monitoring of dental erosion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bossen, Anke; Rakhmatullina, Ekaterina; Lussi, Adrian; Meier, Christoph</p> <p></p> <p>Due to a frequent consumption of acidic food and beverages, the prevalence of dental erosion increases worldwide. In an initial erosion stage, the hard dental tissue is softened due to acidic demineralization. As erosion progresses, a gradual tissue wear occurs resulting in thinning of the enamel. Complete loss of the enamel tissue can be observed in severe clinical cases. Therefore, it is essential to provide a diagnosis tool for an accurate detection and monitoring of dental erosion already at early stages. In this manuscript, we present the development of a <span class="hlt">polarization</span> sensitive imaging camera for the visualization and quantification of dental erosion. The system consists of two CMOS cameras mounted on two sides of a <span class="hlt">polarizing</span> beamsplitter. A <span class="hlt">horizontal</span> linearly <span class="hlt">polarized</span> light source is positioned orthogonal to the camera to ensure an incidence illumination and detection angles of 45°. The specular reflected light from the enamel surface is collected with an objective lens mounted on the beam splitter and divided into <span class="hlt">horizontal</span> (H) and vertical (V) components on each associate camera. Images of non-eroded and eroded enamel surfaces at different erosion degrees were recorded and assessed with diagnostic software. The software was designed to generate and display two types of images: distribution of the reflection intensity (V) and a <span class="hlt">polarization</span> ratio (H-V)/(H+V) throughout the analyzed tissue area. The measurements and visualization of these two optical parameters, i.e. specular reflection intensity and the <span class="hlt">polarization</span> ratio, allowed detection and quantification of enamel erosion at early stages in vitro.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910017762','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910017762"><span>Thermal and albedo mapping of the north and south <span class="hlt">polar</span> regions of Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Paige, D. A.; Keegan, K. D.</p> <p>1991-01-01</p> <p>The first maps are presented of the north and south <span class="hlt">polar</span> regions of Mars. The thermal properties of the midlatitude regions from -60 deg to +60 deg latitude were mapped in previous studies. The presented maps complete the mapping of entire planet. The maps for the north and south <span class="hlt">polar</span> regions were derived from Viking Infrared Thermal Mapper (IRTM) observations. Best fit thermal inertias were determined by comparing the available IRTM 20 micron channel <span class="hlt">brightness</span> within a given region to surface temperatures computed by a diurnal and seasonal thermal model. The model assumes no atmospheric contributions to the surface heat balance. The resulting maps of apparent thermal inertia and average IRTM measured solar channel lambert albedo for the north and south <span class="hlt">polar</span> regions from the poles to +/- 60 deg latitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1990STIN...9125315T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1990STIN...9125315T"><span>Is cepstrum averaging applicable to circularly <span class="hlt">polarized</span> electric-field data?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tunnell, T.</p> <p>1990-04-01</p> <p>In FY 1988 a cepstrum averaging technique was developed to eliminate the ground reflections from charged particle beam (CPB) electromagnetic pulse (EMP) data. The work was done for the Los Alamos National Laboratory Project DEWPOINT at SST-7. The technique averages the cepstra of <span class="hlt">horizontally</span> and vertically <span class="hlt">polarized</span> electric field data (i.e., linearly <span class="hlt">polarized</span> electric field data). This cepstrum averaging technique was programmed into the FORTRAN codes CEP and CEPSIM. Steve Knox, the principal investigator for Project DEWPOINT, asked the authors to determine if the cepstrum averaging technique could be applied to circularly <span class="hlt">polarized</span> electric field data. The answer is, Yes, but some modifications may be necessary. There are two aspects to this answer that we need to address, namely, the Yes and the modifications. First, regarding the Yes, the technique is applicable to elliptically <span class="hlt">polarized</span> electric field data in general: circular <span class="hlt">polarization</span> is a special case of elliptical <span class="hlt">polarization</span>. Secondly, regarding the modifications, greater care may be required in computing the phase in the calculation of the complex logarithm. The calculation of the complex logarithm is the most critical step in cepstrum-based analysis. This memorandum documents these findings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009642','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009642"><span>Characterization of the Morphometry of Impact Craters Hosting <span class="hlt">Polar</span> Deposits in Mercury's North <span class="hlt">Polar</span> Region</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Talpe, Matthieu, J.; Zuber, Maria T.; Neumann, Gregory A.; Mazarico, Erwan; Solomon, Sean C.; Vilas, Faith</p> <p>2012-01-01</p> <p>Earth-based radar images dating back two decades show that the floors of some <span class="hlt">polar</span> craters on Mercury host radar-<span class="hlt">bright</span> deposits that have been proposed to consist of frozen volatiles. Several hypotheses have been put forth to explain their source, including volcanic outgassing, chemical sputtering, and deposition of exogenous water ice. Calculations show that volatiles are thermally stable in permanently shadowed areas. An earlier study of the depths of north <span class="hlt">polar</span> craters determined with photoclinometric techniques applied to Mariner 10 images yielded the conclusion that the mean ratio of crater depth d to rim-crest diameter D for craters hosting <span class="hlt">polar</span> deposits is two-thirds that of the mean ratio for a comparable population of neighboring craters lacking such deposits. This result could be explained by (though doesn't require) the presence of a thick layer of volatiles within the <span class="hlt">polar</span> deposit-hosting craters. Here we use altimetric profiles and topographic maps obtained by the Mercury Laser Altimeter (MLA) to revisit this analysis. MLA is an instrument on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, which has been orbiting Mercury since March 2011. MLA transmits a 1064-nm laser pulse at 8 Hz during MESSENGER's trajectory over Mercury s surface. The MLA illuminates surface areas averaging between 15 m and 100 m in diameter, spaced approx 400 m apart along the spacecraft ground track. The radial precision of individual measurements is <1 m, and the current accuracy with respect to Mercury s center of mass is better than 20 m. As of mid-December 2011, MLA coverage had reached to 15 S and has yielded a comprehensive map of the topography of Mercury s northern hemisphere. The MLA data are used here to quantify the shapes of craters in the north <span class="hlt">polar</span> region and to avoid the shadowing bias of photoclinometric techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11837952','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11837952"><span><span class="hlt">Bright</span>-light mask treatment of delayed sleep phase syndrome.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cole, Roger J; Smith, Julian S; Alcalá, Yvonne C; Elliott, Jeffrey A; Kripke, Daniel F</p> <p>2002-02-01</p> <p>We treated delayed sleep phase syndrome (DSPS) with an illuminated mask that provides light through closed eyelids during sleep. Volunteers received either <span class="hlt">bright</span> white light (2,700 lux, n = 28) or dim red light placebo (0.1 lux, n = 26) for 26 days at home. Mask lights were turned on (< 0.01 lux) 4 h before arising, ramped up for 1 h, and remained on at full <span class="hlt">brightness</span> until arising. Volunteers also attempted to systematically advance sleep time, avoid naps, and avoid evening <span class="hlt">bright</span> light. The light mask was well tolerated and produced little sleep disturbance. The acrophase of urinary 6-sulphatoxymelatonin (6-SMT) excretion advanced significantly from baseline in the <span class="hlt">bright</span> group (p < 0.0006) and not in the dim group, but final phases were not significantly earlier in the <span class="hlt">bright</span> group (ANCOVA ns). <span class="hlt">Bright</span> treatment did produce significantly earlier phases, however, among volunteers whose baseline 6-SMT acrophase was later than the median of 0602 h (<span class="hlt">bright</span> shift: 0732-0554 h, p < 0.0009; dim shift: 0746-0717 h, ns; ANCOVA p = 0.03). In this subgroup, sleep onset advanced significantly only with <span class="hlt">bright</span> but not dim treatment (sleep onset shift: <span class="hlt">bright</span> 0306-0145 h, p < 0.0002; dim 0229-0211 h, ns; ANCOVA p < .05). Despite equal expectations at baseline, participants rated <span class="hlt">bright</span> treatment as more effective than dim treatment (p < 0.04). We conclude that <span class="hlt">bright</span>-light mask treatment advances circadian phase and provides clinical benefit in DSPS individuals whose initial circadian delay is relatively severe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020078396','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020078396"><span>HST NICMOS Observations of the <span class="hlt">Polarization</span> of NGC 1068</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simpson, Janet P.; Colgan, Sean W. J.; Erickson, Edwin F.; Hines, Dean C.; Schultz, A. S. B.; Trammell, Susan R.; DeVincenzi, D. (Technical Monitor)</p> <p>2002-01-01</p> <p>We have observed the <span class="hlt">polarized</span> light at 2 microns in the center of NGC 1068 with HST (Hubble Space Telescope) NICMOS (Near Infrared Camera Multi Object Spectrometer) Camera 2. The nucleus is dominated by a <span class="hlt">bright</span>, unresolved source, <span class="hlt">polarized</span> at a level of 6.0 +/- 1.2% with a position angle of 122 degrees +/- 1.5 degrees. There are two <span class="hlt">polarized</span> lobes extending tip to 8" northeast and southwest of the nucleus. The <span class="hlt">polarized</span> flux in both lobes is quite clumpy, with the maximum <span class="hlt">polarization</span> occurring in the southwest lobe at a level of 17% when smoothed to 0.23" resolution. The perpendiculars to the <span class="hlt">polarization</span> vectors in these two lobes point back to the intense unresolved nuclear source to within one 0.076" Camera 2 pixel, thereby confirming that this source is the origin of the scattered light and therefore the probable AGN (Active Galactic Nuclei) central engine. Whereas the <span class="hlt">polarization</span> of the nucleus is probably caused by dichroic absorption, the <span class="hlt">polarization</span> in the lobes is almost certainly caused by scattering, with very little contribution from dichroic absorption. Features in the <span class="hlt">polarized</span> lobes include a gap at a distance of about 1" from the nucleus toward the southwest lobe and a "knot" of emission about 5" northwest of the nucleus. Both features had been discussed by groundbased observers, but they are much better defined with the high spatial resolution of NICMOS. The northeast knot may be the side of a molecular cloud that is facing the nucleus, which cloud may be preventing the expansion of the northeast radio lobe at the head of the radio synchrotron-radiation-emitting jet. We also report the presence of two ghosts in the Camera 2 <span class="hlt">polarizers</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1354926-robopol-first-season-rotations-optical-polarization-plane-blazars','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1354926-robopol-first-season-rotations-optical-polarization-plane-blazars"><span>RoboPol: first season rotations of optical <span class="hlt">polarization</span> plane in blazars</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Blinov, D.; Pavlidou, V.; Papadakis, I.; ...</p> <p>2015-08-26</p> <p>Here, we present first results on <span class="hlt">polarization</span> swings in optical emission of blazars obtained by RoboPol, a monitoring programme of an unbiased sample of gamma-ray <span class="hlt">bright</span> blazars specially designed for effective detection of such events. A possible connection of <span class="hlt">polarization</span> swing events with periods of high activity in gamma-rays is investigated using the data set obtained during the first season of operation. It was found that the brightest gamma-ray flares tend to be located closer in time to rotation events, which may be an indication of two separate mechanisms responsible for the rotations. Blazars with detected rotations during non-rotating periodsmore » have significantly larger amplitude and faster variations of <span class="hlt">polarization</span> angle than blazars without rotations. Our simulations show that the full set of observed rotations is not a likely outcome (probability ≤1.5 × 10 -2) of a random walk of the <span class="hlt">polarization</span> vector simulated by a multicell model. Furthermore, it is highly unlikely (~5 × 10 -5) that none of our rotations is physically connected with an increase in gamma-ray activity.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25818045','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25818045"><span><span class="hlt">Brightness</span> masking is modulated by disparity structure.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pelekanos, Vassilis; Ban, Hiroshi; Welchman, Andrew E</p> <p>2015-05-01</p> <p>The luminance contrast at the borders of a surface strongly influences surface's apparent <span class="hlt">brightness</span>, as demonstrated by a number of classic visual illusions. Such phenomena are compatible with a propagation mechanism believed to spread contrast information from borders to the interior. This process is disrupted by masking, where the perceived <span class="hlt">brightness</span> of a target is reduced by the brief presentation of a mask (Paradiso & Nakayama, 1991), but the exact visual stage that this happens remains unclear. In the present study, we examined whether <span class="hlt">brightness</span> masking occurs at a monocular-, or a binocular-level of the visual hierarchy. We used backward masking, whereby a briefly presented target stimulus is disrupted by a mask coming soon afterwards, to show that <span class="hlt">brightness</span> masking is affected by binocular stages of the visual processing. We manipulated the 3-D configurations (slant direction) of the target and mask and measured the differential disruption that masking causes on <span class="hlt">brightness</span> estimation. We found that the masking effect was weaker when stimuli had a different slant. We suggest that <span class="hlt">brightness</span> masking is partly mediated by mid-level neuronal mechanisms, at a stage where binocular disparity edge structure has been extracted. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016RScI...87k3704D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016RScI...87k3704D"><span>A simple approach to spectrally resolved fluorescence and <span class="hlt">bright</span> field microscopy over select regions of interest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dahlberg, Peter D.; Boughter, Christopher T.; Faruk, Nabil F.; Hong, Lu; Koh, Young Hoon; Reyer, Matthew A.; Shaiber, Alon; Sherani, Aiman; Zhang, Jiacheng; Jureller, Justin E.; Hammond, Adam T.</p> <p>2016-11-01</p> <p>A standard wide field inverted microscope was converted to a spatially selective spectrally resolved microscope through the addition of a <span class="hlt">polarizing</span> beam splitter, a pair of <span class="hlt">polarizers</span>, an amplitude-mode liquid crystal-spatial light modulator, and a USB spectrometer. The instrument is capable of simultaneously imaging and acquiring spectra over user defined regions of interest. The microscope can also be operated in a <span class="hlt">bright</span>-field mode to acquire absorption spectra of micron scale objects. The utility of the instrument is demonstrated on three different samples. First, the instrument is used to resolve three differently labeled fluorescent beads in vitro. Second, the instrument is used to recover time dependent bleaching dynamics that have distinct spectral changes in the cyanobacteria, Synechococcus leopoliensis UTEX 625. Lastly, the technique is used to acquire the absorption spectra of CH3NH3PbBr3 perovskites and measure differences between nanocrystal films and micron scale crystals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27910631','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27910631"><span>A simple approach to spectrally resolved fluorescence and <span class="hlt">bright</span> field microscopy over select regions of interest.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dahlberg, Peter D; Boughter, Christopher T; Faruk, Nabil F; Hong, Lu; Koh, Young Hoon; Reyer, Matthew A; Shaiber, Alon; Sherani, Aiman; Zhang, Jiacheng; Jureller, Justin E; Hammond, Adam T</p> <p>2016-11-01</p> <p>A standard wide field inverted microscope was converted to a spatially selective spectrally resolved microscope through the addition of a <span class="hlt">polarizing</span> beam splitter, a pair of <span class="hlt">polarizers</span>, an amplitude-mode liquid crystal-spatial light modulator, and a USB spectrometer. The instrument is capable of simultaneously imaging and acquiring spectra over user defined regions of interest. The microscope can also be operated in a <span class="hlt">bright</span>-field mode to acquire absorption spectra of micron scale objects. The utility of the instrument is demonstrated on three different samples. First, the instrument is used to resolve three differently labeled fluorescent beads in vitro. Second, the instrument is used to recover time dependent bleaching dynamics that have distinct spectral changes in the cyanobacteria, Synechococcus leopoliensis UTEX 625. Lastly, the technique is used to acquire the absorption spectra of CH 3 NH 3 PbBr 3 perovskites and measure differences between nanocrystal films and micron scale crystals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24776800','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24776800"><span>Circular <span class="hlt">polarization</span> in the optical afterglow of GRB 121024A.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wiersema, K; Covino, S; Toma, K; van der Horst, A J; Varela, K; Min, M; Greiner, J; Starling, R L C; Tanvir, N R; Wijers, R A M J; Campana, S; Curran, P A; Fan, Y; Fynbo, J P U; Gorosabel, J; Gomboc, A; Götz, D; Hjorth, J; Jin, Z P; Kobayashi, S; Kouveliotou, C; Mundell, C; O'Brien, P T; Pian, E; Rowlinson, A; Russell, D M; Salvaterra, R; di Serego Alighieri, S; Tagliaferri, G; Vergani, S D; Elliott, J; Fariña, C; Hartoog, O E; Karjalainen, R; Klose, S; Knust, F; Levan, A J; Schady, P; Sudilovsky, V; Willingale, R</p> <p>2014-05-08</p> <p>Gamma-ray bursts (GRBs) are most probably powered by collimated relativistic outflows (jets) from accreting black holes at cosmological distances. <span class="hlt">Bright</span> afterglows are produced when the outflow collides with the ambient medium. Afterglow <span class="hlt">polarization</span> directly probes the magnetic properties of the jet when measured minutes after the burst, and it probes the geometric properties of the jet and the ambient medium when measured hours to days after the burst. High values of optical <span class="hlt">polarization</span> detected minutes after the burst of GRB 120308A indicate the presence of large-scale ordered magnetic fields originating from the central engine (the power source of the GRB). Theoretical models predict low degrees of linear <span class="hlt">polarization</span> and no circular <span class="hlt">polarization</span> at late times, when the energy in the original ejecta is quickly transferred to the ambient medium and propagates farther into the medium as a blast wave. Here we report the detection of circularly <span class="hlt">polarized</span> light in the afterglow of GRB 121024A, measured 0.15 days after the burst. We show that the circular <span class="hlt">polarization</span> is intrinsic to the afterglow and unlikely to be produced by dust scattering or plasma propagation effects. A possible explanation is to invoke anisotropic (rather than the commonly assumed isotropic) electron pitch-angle distributions, and we suggest that new models are required to produce the complex microphysics of realistic shocks in relativistic jets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016NJPh...18j3045S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016NJPh...18j3045S"><span>Observation of non-classical correlations in sequential measurements of photon <span class="hlt">polarization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suzuki, Yutaro; Iinuma, Masataka; Hofmann, Holger F.</p> <p>2016-10-01</p> <p>A sequential measurement of two non-commuting quantum observables results in a joint probability distribution for all output combinations that can be explained in terms of an initial joint quasi-probability of the non-commuting observables, modified by the resolution errors and back-action of the initial measurement. Here, we show that the error statistics of a sequential measurement of photon <span class="hlt">polarization</span> performed at different measurement strengths can be described consistently by an imaginary correlation between the statistics of resolution and back-action. The experimental setup was designed to realize variable strength measurements with well-controlled imaginary correlation between the statistical errors caused by the initial measurement of diagonal <span class="hlt">polarizations</span>, followed by a precise measurement of the <span class="hlt">horizontal</span>/vertical <span class="hlt">polarization</span>. We perform the experimental characterization of an elliptically <span class="hlt">polarized</span> input state and show that the same complex joint probability distribution is obtained at any measurement strength.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20551588','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20551588"><span>Effect of evening exposure to <span class="hlt">bright</span> or dim light after daytime <span class="hlt">bright</span> light on absorption of dietary carbohydrates the following morning.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hirota, Naoko; Sone, Yoshiaki; Tokura, Hiromi</p> <p>2010-01-01</p> <p>We had previously reported on the effect of exposure to light on the human digestive system: daytime <span class="hlt">bright</span> light exposure has a positive effect, whereas, evening <span class="hlt">bright</span> light exposure has a negative effect on the efficiency of dietary carbohydrate absorption from the evening meal. These results prompted us to examine whether the light intensity to which subjects are exposed in the evening affects the efficiency of dietary carbohydrate absorption the following morning. In this study, subjects were exposed to either 50 lux (dim light conditions) or 2,000 lux (<span class="hlt">bright</span> light conditions) in the evening for 9 h (from 15:00 to 24:00) after staying under <span class="hlt">bright</span> light in the daytime (under 2,000 lux from 07:00 to 15:00). We measured unabsorbed dietary carbohydrates using the breath-hydrogen test the morning after exposure to either <span class="hlt">bright</span> light or dim light the previous evening. Results showed that there was no significant difference between the two conditions in the amount of breath hydrogen. This indicates that evening exposure to <span class="hlt">bright</span> or dim light after <span class="hlt">bright</span> light exposure in the daytime has no varying effect on digestion or absorption of dietary carbohydrates in the following morning's breakfast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017A%26A...607A..90E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017A%26A...607A..90E"><span>The HIP 79977 debris disk in <span class="hlt">polarized</span> light</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Engler, N.; Schmid, H. M.; Thalmann, Ch.; Boccaletti, A.; Bazzon, A.; Baruffolo, A.; Beuzit, J. L.; Claudi, R.; Costille, A.; Desidera, S.; Dohlen, K.; Dominik, C.; Feldt, M.; Fusco, T.; Ginski, C.; Gisler, D.; Girard, J. H.; Gratton, R.; Henning, T.; Hubin, N.; Janson, M.; Kasper, M.; Kral, Q.; Langlois, M.; Lagadec, E.; Ménard, F.; Meyer, M. R.; Milli, J.; Mouillet, D.; Olofsson, J.; Pavlov, A.; Pragt, J.; Puget, P.; Quanz, S. P.; Roelfsema, R.; Salasnich, B.; Siebenmorgen, R.; Sissa, E.; Suarez, M.; Szulagyi, J.; Turatto, M.; Udry, S.; Wildi, F.</p> <p>2017-11-01</p> <p>Context. Debris disks are observed around 10 to 20% of FGK main-sequence stars as infrared excess emission. They are important signposts for the presence of colliding planetesimals and therefore provide important information about the evolution of planetary systems. Direct imaging of such disks reveals their geometric structure and constrains their dust-particle properties. Aims: We present observations of the known edge-on debris disk around HIP 79977 (HD 146897) taken with the ZIMPOL differential polarimeter of the SPHERE instrument. We measure the observed <span class="hlt">polarization</span> signal and investigate the diagnostic potential of such data with model simulations. Methods: SPHERE-ZIMPOL polarimetric data of the 15 Myr-old F star HIP 79977 (Upper Sco, 123 pc) were taken in the Very Broad Band (VBB) filter (λc = 735 nm, Δλ = 290 nm) with a spatial resolution of about 25 mas. Imaging polarimetry efficiently suppresses the residual speckle noise from the AO system and provides a differential signal with relatively small systematic measuring uncertainties. We measure the <span class="hlt">polarization</span> flux along and perpendicular to the disk spine of the highly inclined disk for projected separations between 0.2'' (25 AU) and 1.6'' (200 AU). We perform model calculations for the <span class="hlt">polarized</span> flux of an optically thin debris disk which are used to determine or constrain the disk parameters of HIP 79977. Results: We measure a <span class="hlt">polarized</span> flux contrast ratio for the disk of (Fpol)disk/F∗ = (5.5 ± 0.9) × 10-4 in the VBB filter. The surface <span class="hlt">brightness</span> of the <span class="hlt">polarized</span> flux reaches a maximum of SBmax = 16.2 mag arcsec-2 at a separation of 0.2''-0.5'' along the disk spine with a maximum surface <span class="hlt">brightness</span> contrast of 7.64 mag arcsec-2. The <span class="hlt">polarized</span> flux has a minimum near the star <0.2'' because no or only little <span class="hlt">polarization</span> is produced by forward or backward scattering in the disk section lying in front of or behind the star. The width of the disk perpendicular to the spine shows a systematic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990023305','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990023305"><span>Microwave <span class="hlt">Brightness</span> Temperatures of Tilted Convective Systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hong, Ye; Haferman, Jeffrey L.; Olson, William S.; Kummerow, Christian D.</p> <p>1998-01-01</p> <p>Aircraft and ground-based radar data from the Tropical Ocean and Global Atmosphere Coupled-Ocean Atmosphere Response Experiment (TOGA COARE) show that convective systems are not always vertical. Instead, many are tilted from vertical. Satellite passive microwave radiometers observe the atmosphere at a viewing angle. For example, the Special Sensor Microwave/Imager (SSM/I) on Defense Meteorological Satellite Program (DMSP) satellites and the Tropical Rainfall Measurement Mission (TRMM) Microwave Imager (TMI) on the TRMM satellite have an incident angle of about 50deg. Thus, the <span class="hlt">brightness</span> temperature measured from one direction of tilt may be different than that viewed from the opposite direction due to the different optical depth. This paper presents the investigation of passive microwave <span class="hlt">brightness</span> temperatures of tilted convective systems. To account for the effect of tilt, a 3-D backward Monte Carlo radiative transfer model has been applied to a simple tilted cloud model and a dynamically evolving cloud model to derive the <span class="hlt">brightness</span> temperature. The radiative transfer results indicate that <span class="hlt">brightness</span> temperature varies when the viewing angle changes because of the different optical depth. The tilt increases the displacements between high 19 GHz <span class="hlt">brightness</span> temperature (Tb(sub 19)) due to liquid emission from lower level of cloud and the low 85 GHz <span class="hlt">brightness</span> temperature (Tb(sub 85)) due to ice scattering from upper level of cloud. As the resolution degrades, the difference of <span class="hlt">brightness</span> temperature due to the change of viewing angle decreases dramatically. The dislocation between Tb(sub 19) and Tb(sub 85), however, remains prominent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22034600-evidence-polar-ray-jets-sources-microstream-peaks-solar-wind','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22034600-evidence-polar-ray-jets-sources-microstream-peaks-solar-wind"><span>EVIDENCE FOR <span class="hlt">POLAR</span> X-RAY JETS AS SOURCES OF MICROSTREAM PEAKS IN THE SOLAR WIND</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Neugebauer, Marcia, E-mail: mneugeb@lpl.arizona.edu</p> <p>2012-05-01</p> <p>It is proposed that the interplanetary manifestations of X-ray jets observed in solar <span class="hlt">polar</span> coronal holes during periods of low solar activity are the peaks of the so-called microstreams observed in the fast <span class="hlt">polar</span> solar wind. These microstreams exhibit velocity fluctuations of {+-}35 km s{sup -1}, higher kinetic temperatures, slightly higher proton fluxes, and slightly higher abundances of the low-first-ionization-potential element iron relative to oxygen ions than the average <span class="hlt">polar</span> wind. Those properties can all be explained if the fast microstreams result from the magnetic reconnection of <span class="hlt">bright</span>-point loops, which leads to X-ray jets which, in turn, result in solarmore » <span class="hlt">polar</span> plumes. Because most of the microstream peaks are bounded by discontinuities of solar origin, jets are favored over plumes for the majority of the microstream peaks.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ApJ...835...12J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ApJ...835...12J"><span>Gaps in Protoplanetary Disks as Signatures of Planets. III. <span class="hlt">Polarization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jang-Condell, Hannah</p> <p>2017-01-01</p> <p>Polarimetric observations of T Tauri and Herbig Ae/Be stars are a powerful way to image protoplanetary disks. However, interpretation of these images is difficult because the degree of <span class="hlt">polarization</span> is highly sensitive to the angle of scattering of stellar light off the disk surface. We examine how disks with and without gaps created by planets appear in scattered <span class="hlt">polarized</span> light as a function of inclination angle. Isophotes of inclined disks without gaps are distorted in <span class="hlt">polarized</span> light, giving the appearance that the disks are more eccentric or more highly inclined than they truly are. Apparent gap locations are unaffected by <span class="hlt">polarization</span>, but the gap contrast changes. In face-on disks with gaps, we find that the brightened far edge of the gap scatters less <span class="hlt">polarized</span> light than the rest of the disk, resulting in slightly decreased contrast between the gap trough and the brightened far edge. In inclined disks, gaps can take on the appearance of being localized “holes” in <span class="hlt">brightness</span> rather than full axisymmetric structures. Photocenter offsets along the minor axis of the disk in both total intensity and <span class="hlt">polarized</span> intensity images can be readily explained by the finite thickness of the disk. Alone, <span class="hlt">polarized</span> scattered light images of disks do not necessarily reveal intrinsic disk structure. However, when combined with total intensity images, the orientation of the disk can be deduced and much can be learned about disk structure and dust properties.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22664020-gaps-protoplanetary-disks-signatures-planets-iii-polarization','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22664020-gaps-protoplanetary-disks-signatures-planets-iii-polarization"><span>GAPS IN PROTOPLANETARY DISKS AS SIGNATURES OF PLANETS. III. <span class="hlt">POLARIZATION</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Jang-Condell, Hannah</p> <p>2017-01-20</p> <p>Polarimetric observations of T Tauri and Herbig Ae/Be stars are a powerful way to image protoplanetary disks. However, interpretation of these images is difficult because the degree of <span class="hlt">polarization</span> is highly sensitive to the angle of scattering of stellar light off the disk surface. We examine how disks with and without gaps created by planets appear in scattered <span class="hlt">polarized</span> light as a function of inclination angle. Isophotes of inclined disks without gaps are distorted in <span class="hlt">polarized</span> light, giving the appearance that the disks are more eccentric or more highly inclined than they truly are. Apparent gap locations are unaffected bymore » <span class="hlt">polarization</span>, but the gap contrast changes. In face-on disks with gaps, we find that the brightened far edge of the gap scatters less <span class="hlt">polarized</span> light than the rest of the disk, resulting in slightly decreased contrast between the gap trough and the brightened far edge. In inclined disks, gaps can take on the appearance of being localized “holes” in <span class="hlt">brightness</span> rather than full axisymmetric structures. Photocenter offsets along the minor axis of the disk in both total intensity and <span class="hlt">polarized</span> intensity images can be readily explained by the finite thickness of the disk. Alone, <span class="hlt">polarized</span> scattered light images of disks do not necessarily reveal intrinsic disk structure. However, when combined with total intensity images, the orientation of the disk can be deduced and much can be learned about disk structure and dust properties.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22518616-pds-circumstellar-disk-seen-polarized-light-gemini-planet-imager','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22518616-pds-circumstellar-disk-seen-polarized-light-gemini-planet-imager"><span>THE PDS 66 CIRCUMSTELLAR DISK AS SEEN IN <span class="hlt">POLARIZED</span> LIGHT WITH THE GEMINI PLANET IMAGER</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wolff, Schuyler G.; Greenbaum, Alexandra Z.; Perrin, Marshall</p> <p>2016-02-10</p> <p>We present H- and K-band imaging polarimetry for the PDS 66 circumstellar disk obtained during the commissioning of the Gemini Planet Imager (GPI). <span class="hlt">Polarization</span> images reveal a clear detection of the disk in to the 0.″12 inner working angle (IWA) in the H band, almost three times closer to the star than the previous Hubble Space Telescope (HST) observations with NICMOS and STIS (0.″35 effective IWA). The centro-symmetric <span class="hlt">polarization</span> vectors confirm that the <span class="hlt">bright</span> inner disk detection is due to circumstellar scattered light. A more diffuse disk extends to a <span class="hlt">bright</span> outer ring centered at 80 AU. We discuss several physicalmore » mechanisms capable of producing the observed ring + gap structure. GPI data confirm enhanced scattering on the east side of the disk that is inferred to be nearer to us. We also detect a lateral asymmetry in the south possibly due to shadowing from material within the IWA. This likely corresponds to a temporally variable azimuthal asymmetry observed in HST/STIS coronagraphic imaging.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22521597-magnetic-flux-supplement-coronal-bright-points','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22521597-magnetic-flux-supplement-coronal-bright-points"><span>MAGNETIC FLUX SUPPLEMENT TO CORONAL <span class="hlt">BRIGHT</span> POINTS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Mou, Chaozhou; Huang, Zhenghua; Xia, Lidong</p> <p></p> <p>Coronal <span class="hlt">bright</span> points (BPs) are associated with magnetic bipolar features (MBFs) and magnetic cancellation. Here we investigate how BP-associated MBFs form and how the consequent magnetic cancellation occurs. We analyze longitudinal magnetograms from the Helioseismic and Magnetic Imager to investigate the photospheric magnetic flux evolution of 70 BPs. From images taken in the 193 Å passband of the Atmospheric Imaging Assembly (AIA) we dermine that the BPs’ lifetimes vary from 2.7 to 58.8 hr. The formation of the BP MBFs is found to involve three processes, namely, emergence, convergence, and local coalescence of the magnetic fluxes. The formation of anmore » MBF can involve more than one of these processes. Out of the 70 cases, flux emergence is the main process of an MBF buildup of 52 BPs, mainly convergence is seen in 28, and 14 cases are associated with local coalescence. For MBFs formed by bipolar emergence, the time difference between the flux emergence and the BP appearance in the AIA 193 Å passband varies from 0.1 to 3.2 hr with an average of 1.3 hr. While magnetic cancellation is found in all 70 BPs, it can occur in three different ways: (I) between an MBF and small weak magnetic features (in 33 BPs); (II) within an MBF with the two <span class="hlt">polarities</span> moving toward each other from a large distance (34 BPs); (III) within an MBF whose two main <span class="hlt">polarities</span> emerge in the same place simultaneously (3 BPs). While an MBF builds up the skeleton of a BP, we find that the magnetic activities responsible for the BP heating may involve small weak fields.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2659800','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2659800"><span>The <span class="hlt">Brightness</span> of Colour</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Corney, David; Haynes, John-Dylan; Rees, Geraint; Lotto, R. Beau</p> <p>2009-01-01</p> <p>Background The perception of <span class="hlt">brightness</span> depends on spatial context: the same stimulus can appear light or dark depending on what surrounds it. A less well-known but equally important contextual phenomenon is that the colour of a stimulus can also alter its <span class="hlt">brightness</span>. Specifically, stimuli that are more saturated (i.e. purer in colour) appear brighter than stimuli that are less saturated at the same luminance. Similarly, stimuli that are red or blue appear brighter than equiluminant yellow and green stimuli. This non-linear relationship between stimulus intensity and <span class="hlt">brightness</span>, called the Helmholtz-Kohlrausch (HK) effect, was first described in the nineteenth century but has never been explained. Here, we take advantage of the relative simplicity of this ‘illusion’ to explain it and contextual effects more generally, by using a simple Bayesian ideal observer model of the human visual ecology. We also use fMRI brain scans to identify the neural correlates of <span class="hlt">brightness</span> without changing the spatial context of the stimulus, which has complicated the interpretation of related fMRI studies. Results Rather than modelling human vision directly, we use a Bayesian ideal observer to model human visual ecology. We show that the HK effect is a result of encoding the non-linear statistical relationship between retinal images and natural scenes that would have been experienced by the human visual system in the past. We further show that the complexity of this relationship is due to the response functions of the cone photoreceptors, which themselves are thought to represent an efficient solution to encoding the statistics of images. Finally, we show that the locus of the response to the relationship between images and scenes lies in the primary visual cortex (V1), if not earlier in the visual system, since the <span class="hlt">brightness</span> of colours (as opposed to their luminance) accords with activity in V1 as measured with fMRI. Conclusions The data suggest that perceptions of <span class="hlt">brightness</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24671223','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24671223"><span>Phototaxis and polarotaxis hand in hand: night dispersal flight of aquatic insects distracted synergistically by light intensity and reflection <span class="hlt">polarization</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Boda, Pál; Horváth, Gábor; Kriska, György; Blahó, Miklós; Csabai, Zoltán</p> <p>2014-05-01</p> <p>Based on an earlier observation in the field, we hypothesized that light intensity and <span class="hlt">horizontally</span> <span class="hlt">polarized</span> reflected light may strongly influence the flight behaviour of night-active aquatic insects. We assumed that phototaxis and polarotaxis together have a more harmful effect on the dispersal flight of these insects than they would have separately. We tested this hypothesis in a multiple-choice field experiment using <span class="hlt">horizontal</span> test surfaces laid on the ground. We offered simultaneously the following visual stimuli for aerial aquatic insects: (1) lamplit matte black canvas inducing phototaxis alone, (2) unlit shiny black plastic sheet eliciting polarotaxis alone, (3) lamplit shiny black plastic sheet inducing simultaneously phototaxis and polarotaxis, and (4) unlit matte black canvas as a visually unattractive control. The unlit matte black canvas trapped only a negligible number (13) of water insects. The sum (16,432) of the total numbers of water beetles and bugs captured on the lamplit matte black canvas (7,922) and the unlit shiny black plastic sheet (8,510) was much smaller than the total catch (29,682) caught on the lamplit shiny black plastic sheet. This provides experimental evidence for the synergistic interaction of phototaxis (elicited by the unpolarized direct lamplight) and polarotaxis (induced by the strongly and <span class="hlt">horizontally</span> <span class="hlt">polarized</span> plastic-reflected light) in the investigated aquatic insects. Thus, <span class="hlt">horizontally</span> <span class="hlt">polarizing</span> artificial lamplit surfaces can function as an effective ecological trap due to this synergism of optical cues, especially in the urban environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NW....101..385B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NW....101..385B"><span>Phototaxis and polarotaxis hand in hand: night dispersal flight of aquatic insects distracted synergistically by light intensity and reflection <span class="hlt">polarization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boda, Pál; Horváth, Gábor; Kriska, György; Blahó, Miklós; Csabai, Zoltán</p> <p>2014-05-01</p> <p>Based on an earlier observation in the field, we hypothesized that light intensity and <span class="hlt">horizontally</span> <span class="hlt">polarized</span> reflected light may strongly influence the flight behaviour of night-active aquatic insects. We assumed that phototaxis and polarotaxis together have a more harmful effect on the dispersal flight of these insects than they would have separately. We tested this hypothesis in a multiple-choice field experiment using <span class="hlt">horizontal</span> test surfaces laid on the ground. We offered simultaneously the following visual stimuli for aerial aquatic insects: (1) lamplit matte black canvas inducing phototaxis alone, (2) unlit shiny black plastic sheet eliciting polarotaxis alone, (3) lamplit shiny black plastic sheet inducing simultaneously phototaxis and polarotaxis, and (4) unlit matte black canvas as a visually unattractive control. The unlit matte black canvas trapped only a negligible number (13) of water insects. The sum (16,432) of the total numbers of water beetles and bugs captured on the lamplit matte black canvas (7,922) and the unlit shiny black plastic sheet (8,510) was much smaller than the total catch (29,682) caught on the lamplit shiny black plastic sheet. This provides experimental evidence for the synergistic interaction of phototaxis (elicited by the unpolarized direct lamplight) and polarotaxis (induced by the strongly and <span class="hlt">horizontally</span> <span class="hlt">polarized</span> plastic-reflected light) in the investigated aquatic insects. Thus, <span class="hlt">horizontally</span> <span class="hlt">polarizing</span> artificial lamplit surfaces can function as an effective ecological trap due to this synergism of optical cues, especially in the urban environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AIPC..879..428O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AIPC..879..428O"><span>Orbit Correction for the Newly Developed <span class="hlt">Polarization</span>-Switching Undulator</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Obina, Takashi; Honda, Tohru; Shioya, Tatsuro; Kobayashi, Yukinori; Tsuchiya, Kimichika; Yamamoto, Shigeru</p> <p>2007-01-01</p> <p>A new scheme of undulator magnet arrangements has been proposed and developed as a <span class="hlt">polarization</span>-switching radiation source, and its test-stand was installed in the 2.5-GeV Photon Factory storage ring (PF ring) in order to investigate the effects on the beam orbit. The closed orbit distortion (COD) over 200 μm was produced in a vertical direction when we switched the <span class="hlt">polarization</span> of the radiation from the test-stand. In a <span class="hlt">horizontal</span> direction, the COD was less than 50μm. The results agreed well with the predictions from the magnetic-field measurement on the bench. In order to suppress the CODs and realize a stable operation of the ring with the <span class="hlt">polarization</span>-switching, we developed an orbit correction system which consists of an encoder to detect motion of magnets, a pair of beam position monitors (BPMs), signal processing parts, and a pair of steering magnets. We succeeded in suppressing the CODs to the level below 3μm using the system even when we switch the <span class="hlt">polarization</span> at a maximum frequency of 0.8 Hz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996SPIE.2842..501M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996SPIE.2842..501M"><span>Pattern and <span class="hlt">polarization</span> measurements of integrated-circuit spiral antennas at 10-μm wavelength</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>MacDonald, Michael E.; Grossman, Erich N.</p> <p>1996-12-01</p> <p>Radiation patterns are presented for planar equiangular spiral antennas at wavelengths of approximately 10 micrometers . These antennas are fabricated using integrated-circuit processes on silicon substrates and are coupled through dielectric lenses. Patterns are presented over a full 2D scan for orthogonal linear <span class="hlt">polarizations</span>, and for left- circular (LCP) and right-circular (RCP) <span class="hlt">polarizations</span>. The antennas respond preferentially to left-circularly <span class="hlt">polarized</span> radiation, as expected for the left-handed sense of the spiral arms. Cross-<span class="hlt">polarization</span> ratios as large as 10 dB in circular <span class="hlt">polarization</span> are obtained, corresponding to an axial ratio of 1.2. No difference in response between <span class="hlt">horizontally</span> and vertically <span class="hlt">polarized</span> radiation is observed, as expected for circularly <span class="hlt">polarized</span> antennas. Directivities as large as 14 dB in left-circular <span class="hlt">polarization</span> have been obtained. The cross-<span class="hlt">polarized</span> directivity is considerably lower than the co-<span class="hlt">polarized</span> directivity. All patterns are approximately circularly symmetric about the (theta) equals 0 axis. The cross-<span class="hlt">polarization</span> ratio and pattern symmetry strongly depend on the alignment of the antenna and detector response is antenna coupled, even at radiation wavelength of the same order of magnitude as the resolution limit of the optical lithography used to define the antenna geometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770004323','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770004323"><span>Airborne antenna <span class="hlt">polarization</span> study for the microwave landing system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gilreath, M. C.</p> <p>1976-01-01</p> <p>The feasibility of the microwave landing system (MLS) airborne antenna pattern coverage requirements are investigated for a large commercial aircraft using a single omnidirectional antenna. Omnidirectional antennas having vertical and <span class="hlt">horizontal</span> <span class="hlt">polarizations</span> were evaluated at several different station locations on a one-eleventh scale model Boeing 737 aircraft. The results obtained during this experimental program are presented which include principal plane antenna patterns and complete volumetric coverage plots.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29809046','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29809046"><span>Exposure to <span class="hlt">bright</span> light biases effort-based decisions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bijleveld, Erik; Knufinke, Melanie</p> <p>2018-06-01</p> <p>Secreted in the evening and the night, melatonin suppresses activity of the mesolimbic dopamine pathway, a brain pathway involved in reward processing. However, exposure to <span class="hlt">bright</span> light diminishes-or even prevents-melatonin secretion. Thus, we hypothesized that reward processing, in the evening, is more pronounced in <span class="hlt">bright</span> light (vs. dim light). Healthy human participants carried out three tasks that tapped into various aspects of reward processing (effort expenditure for rewards task [EEfRT]; two-armed bandit task [2ABT]; balloon analogue risk task [BART). <span class="hlt">Brightness</span> was manipulated within-subjects (<span class="hlt">bright</span> vs. dim light), in separate evening sessions. During the EEfRT, participants used reward-value information more strongly when they were exposed to <span class="hlt">bright</span> light (vs. dim light). This finding supported our hypothesis. However, exposure to <span class="hlt">bright</span> light did not significantly affect task behavior on the 2ABT and the BART. While future research is necessary (e.g., to zoom in on working mechanisms), these findings have potential implications for the design of physical work environments. (PsycINFO Database Record (c) 2018 APA, all rights reserved).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/863039','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/863039"><span><span class="hlt">Horizontal</span> baffle for nuclear reactors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Rylatt, John A.</p> <p>1978-01-01</p> <p>A <span class="hlt">horizontal</span> baffle disposed in the annulus defined between the core barrel and the thermal liner of a nuclear reactor thereby physically separating the outlet region of the core from the annular area below the <span class="hlt">horizontal</span> baffle. The <span class="hlt">horizontal</span> baffle prevents hot coolant that has passed through the reactor core from thermally damaging apparatus located in the annulus below the <span class="hlt">horizontal</span> baffle by utilizing the thermally induced bowing of the <span class="hlt">horizontal</span> baffle to enhance sealing while accommodating lateral motion of the baffle base plate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16271158','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16271158"><span>Reviving a neglected celestial underwater <span class="hlt">polarization</span> compass for aquatic animals.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Waterman, Talbot H</p> <p>2006-02-01</p> <p>Substantial in situ measurements on clear days in a variety of marine environments at depths in the water down to 200 m have demonstrated the ubiquitous daytime presence of sun-related e-vector (=plane of <span class="hlt">polarization</span>) patterns. In most lines of sight the e-vectors tilt from <span class="hlt">horizontal</span> towards the sun at angles equal to the apparent underwater refracted zenith angle of the sun. A maximum tilt-angle of approximately 48.5 degrees , is reached in <span class="hlt">horizontal</span> lines of sight at 90 degrees to the sun's bearing (the plane of incidence). This tilt limit is set by Snell's window, when the sun is on the horizon. The biological literature since the 1980s has been pervaded with assumptions that daytime aquatic e-vectors are mainly <span class="hlt">horizontal</span>. This review attempts to set the record straight concerning the potential use of underwater e-vectors as a visual compass and to reopen the field to productive research on aquatic animals' orientation and navigation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013KPCB...29..228M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013KPCB...29..228M"><span>Shadow mechanism and the opposition effect of <span class="hlt">brightness</span> of atmosphereless celestial bodies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morozhenko, A. V.; Vidmachenko, A. P.</p> <p>2013-09-01</p> <p>We consider the Irvine-Yanovistkii modification of the shadow model developed by Hapke for the opposition effect of <span class="hlt">brightness</span>. The relation between the single scattering albedo ω and the transparency coefficient of particles κ is suggested to be used in the form κ = (1 - ω) n, which allows the number of unknowns in the model to be reduced to two parameters (the packing density of particles g and ω) and the single-scattering phase function Ξ(α). The analysis of spectrophotometric measurements of the moon and Mars showed that the data on the observed opposition effect and the changes in the color index with the phase angle α well agree if the values of n = 0.25 and g = 0.4 (the moon) and 0.6 (Mars) are assumed in calculations. When being applied to asteroids of several types, this method also yielded a satisfactory agreement. For the E-type asteroids, the sets of parameters are [g = 0.6, ω = 0.6, A g = 0.21, and q = 0.83] or [g = 0.3, ω = 0.4, A g = 0.15, and q = 0.71] under the Martian single-scattering phase function; for the M-type asteroids, it is [g = 0.4, ω ≤ 0.1, A g ≤ 0.075, and q ≤ 0.42] under the lunar single-scattering phase function; for the S-type asteroids, it is [g = 0.4, ω = 0.4, A g = 0.28, and q = 0.49] under the lunar single-scattering phase function; and for the C-type asteroids, it is [g = 0.6, ω ≤ 0.1, A g ≤ 0.075, and q = 0.43] under the modified lunar single-scattering phase function. The <span class="hlt">polarization</span> measurements fulfilled by Gehrels et al. (1964) for the <span class="hlt">bright</span> feature on the lunar surface, Copernicus (L = -20°08', φ = +10°11'), at a phase angle α = 1.6° revealed the deviations in the position of the <span class="hlt">polarization</span> plane from that typical for the negative branch. They were 22° and 12° in the G and I filters, respectively. At the same time, the deviation was within the error (±3° in the U filter and for the dark feature Plato (L = -10°32', φ = +51°25'), which can be caused by the coherent mechanism of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008SPIE.6621E..1KW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008SPIE.6621E..1KW"><span>Endoscopic spectral-domain <span class="hlt">polarization</span>-sensitive optical coherence tomography system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Yi; Chen, Xiaodong; Hu, Zhiqiang; Li, Qiao; Yu, Daoyin</p> <p>2008-02-01</p> <p>In this paper, we introduced a fiber-based endoscopic Spectral-domain <span class="hlt">Polarization</span>-sensitive OCT (SD-PS-OCT) experimental scheme for detecting the internal organ disease, which is based on low-coherence interferometer and two spectrometers. The SD-PS-OCT has the advantages of both Spectral-domain OCT (SD-OCT) and <span class="hlt">Polarization</span>-sensitive OCT (PS-OCT). It is able to get the real-time image of reflectivity and birefringence distribution of tissue at the same time. The usage of SD-PS-OCT in endoscopic diagnosing system provides it the possibility to detect the internal organ disease. Since SD-PS-OCT can image the pathological changes of biological tissue below surface (1-3mm) with high resolution (1-15μm), it is able to help diagnosing early diseases of internal organs, which makes it a biomedical technology with <span class="hlt">bright</span> future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoJI.204..968J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoJI.204..968J"><span>Quantifying the similarity of seismic <span class="hlt">polarizations</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jones, Joshua P.; Eaton, David W.; Caffagni, Enrico</p> <p>2016-02-01</p> <p>Assessing the similarities of seismic attributes can help identify tremor, low signal-to-noise (S/N) signals and converted or reflected phases, in addition to diagnosing site noise and sensor misalignment in arrays. <span class="hlt">Polarization</span> analysis is a widely accepted method for studying the orientation and directional characteristics of seismic phases via computed attributes, but similarity is ordinarily discussed using qualitative comparisons with reference values or known seismic sources. Here we introduce a technique for quantitative <span class="hlt">polarization</span> similarity that uses weighted histograms computed in short, overlapping time windows, drawing on methods adapted from the image processing and computer vision literature. Our method accounts for ambiguity in azimuth and incidence angle and variations in S/N ratio. Measuring <span class="hlt">polarization</span> similarity allows easy identification of site noise and sensor misalignment and can help identify coherent noise and emergent or low S/N phase arrivals. Dissimilar azimuths during phase arrivals indicate misaligned <span class="hlt">horizontal</span> components, dissimilar incidence angles during phase arrivals indicate misaligned vertical components and dissimilar linear <span class="hlt">polarization</span> may indicate a secondary noise source. Using records of the Mw = 8.3 Sea of Okhotsk earthquake, from Canadian National Seismic Network broad-band sensors in British Columbia and Yukon Territory, Canada, and a vertical borehole array at Hoadley gas field, central Alberta, Canada, we demonstrate that our method is robust to station spacing. Discrete wavelet analysis extends <span class="hlt">polarization</span> similarity to the time-frequency domain in a straightforward way. Time-frequency <span class="hlt">polarization</span> similarities of borehole data suggest that a coherent noise source may have persisted above 8 Hz several months after peak resource extraction from a `flowback' type hydraulic fracture.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900042461&hterms=bright+hour&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbright%2Bhour','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900042461&hterms=bright+hour&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbright%2Bhour"><span>Coronal <span class="hlt">bright</span> points at 6cm wavelength</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fu, Qijun; Kundu, M. R.; Schmahl, E. J.</p> <p>1988-01-01</p> <p>Results are presented from observations of <span class="hlt">bright</span> points at a wavelength of 6-cm using the VLA with a spatial resolution of 1.2 arcsec. During two hours of observations, 44 sources were detected with <span class="hlt">brightness</span> temperatures between 2000 and 30,000 K. Of these sources, 27 are associated with weak dark He 10830 A features at distances less than 40 arcsecs. Consideration is given to variations in the source parameters and the relationship between ephemeral regions and <span class="hlt">bright</span> points.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AIPC.1429..140H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AIPC.1429..140H"><span>Optical <span class="hlt">polarization</span> observations of epsilon Aurigae during the 2009-2011 eclipse</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Henson, Gary D.; Burdette, John; Gray, Sharon</p> <p>2012-05-01</p> <p><span class="hlt">Polarization</span> observations of the unique eclipsing binary, Epsilon Aurigae, are being carried out using a new dual beam imaging polarimeter on the 0.36m telescope of the Harry D. Powell Observatory. This <span class="hlt">bright</span> binary system has a 27.1 year period with an eclipse duration of nearly two years. The primary is known to be a pulsating F0 supergiant with the secondary a large and essentially opaque disk. We report here on the characteristics of the polarimeter and on the status of V-band observations that are being obtained to better understand the system's geometry and the nature of its two components. In particular, the characteristics of the secondary disk remain a puzzle. Results are compared to <span class="hlt">polarization</span> observations from the 1982-1984 eclipse.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850007251&hterms=tinbergen&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtinbergen','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850007251&hterms=tinbergen&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtinbergen"><span>Optical <span class="hlt">Polarization</span> as a Probe of the Local Interstellar Medium</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tinbergen, J.</p> <p>1984-01-01</p> <p>The use of interstellar <span class="hlt">polarization</span> as a tool for measuring interstellar dust is discussed. Problems resulting from dust and magnetic field configurations becoming mixed up are discussed, as is the availability of sufficiently <span class="hlt">bright</span> stars to obtain the photons needed for precision measurements. It is proposed that: (1) on the scale of several hundred parsec, there is a preferential magnetic field direction, as evidenced by observations at the Galactic poles and selected longitudes in the Galactic plane; (2) the local (r 50 pc) region is devoid of dust, as evidenced by the mean square degree of <span class="hlt">polarization</span> as a function of distance; and, less certainly, that (3) at a distance of less than 5 pc, there is a patch of dust which may be of interest in connection with cloud models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ATel11688....1F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ATel11688....1F"><span>The ZTF <span class="hlt">Bright</span> Transient Survey</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fremling, C.; Sharma, Y.; Kulkarni, S. R.; Miller, A. A.; Taggart, K.; Perley, D. A.; Gooba, A.</p> <p>2018-06-01</p> <p>As a supplement to the Zwicky Transient Facility (ZTF; ATel #11266) public alerts (ATel #11685) we plan to report (following ATel #11615) <span class="hlt">bright</span> probable supernovae identified in the raw alert stream from the ZTF Northern Sky Survey ("Celestial Cinematography"; see Bellm & Kulkarni, 2017, Nature Astronomy 1, 71) to the Transient Name Server (https://wis-tns.weizmann.ac.il) on a daily basis; the ZTF <span class="hlt">Bright</span> Transient Survey (BTS; see Kulkarni et al., 2018; arXiv:1710.04223).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19760035678&hterms=mcdonald&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmcdonald','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19760035678&hterms=mcdonald&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmcdonald"><span>The night sky <span class="hlt">brightness</span> at McDonald Observatory</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kalinowski, J. K.; Roosen, R. G.; Brandt, J. C.</p> <p>1975-01-01</p> <p>Baseline observations of the night sky <span class="hlt">brightness</span> in B and V are presented for McDonald Observatory. In agreement with earlier work by Elvey and Rudnick (1937) and Elvey (1943), significant night-to-night and same-night variations in sky <span class="hlt">brightness</span> are found. Possible causes for these variations are discussed. The largest variation in sky <span class="hlt">brightness</span> found during a single night is approximately a factor of two, a value which corresponds to a factor-of-four variation in airglow <span class="hlt">brightness</span>. The data are used to comment on the accuracy of previously published surface photometry of M 81.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SpWea..15.1373E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SpWea..15.1373E"><span>Possible Cause of Extremely <span class="hlt">Bright</span> Aurora Witnessed in East Asia on 17 September 1770</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ebihara, Yusuke; Hayakawa, Hisashi; Iwahashi, Kiyomi; Tamazawa, Harufumi; Kawamura, Akito Davis; Isobe, Hiroaki</p> <p>2017-10-01</p> <p>Extremely <span class="hlt">bright</span> aurora was witnessed in East Asia on 17 September 1770, according to historical documents. The aurora was described as "as <span class="hlt">bright</span> as a night with full moon" at magnetic latitude of 25°. The aurora was dominated by red color extending from near the horizon up beyond the <span class="hlt">polar</span> star (corresponding to elevation angle of 35°). We performed a two-stream electron transport code to calculate the volume emission rates at 557.7 nm (OI) and 630.0 nm (OI). Two types of distribution of precipitating electrons were assumed. The first one is based on the unusually intense electron flux measured by the DMSP satellite in the March 1989 storm. The distribution consists of hot (peaking at 3 keV) and cold (peaking at 71 eV) components. The second one is the same as the first one, but the hot component is removed. We call this high-intensity low-energy electrons (HILEEs). The first spectrum results in an auroral display with a <span class="hlt">bright</span>, lower green border. The second one results in red-dominated aurora extending up to the elevation angle of 35° when the equatorward boundary of the electron precipitation is located at 32° invariant latitude. The poleward boundary of the precipitation would be 42° invariant latitude or greater to explain the auroral display extending from near the horizon. The origin of the HILEEs is probably the plasma sheet or the plasmasphere that is transported earthward to L 1.39 due to enhanced magnetospheric convection. Local heating or acceleration is also plausible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22364707-near-ir-imaging-polarimetry-toward-bright-rimmed-cloud-magnetic-field-sfo','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22364707-near-ir-imaging-polarimetry-toward-bright-rimmed-cloud-magnetic-field-sfo"><span>NEAR-IR IMAGING POLARIMETRY TOWARD A <span class="hlt">BRIGHT</span>-RIMMED CLOUD: MAGNETIC FIELD IN SFO 74</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Kusune, Takayoshi; Sugitani, Koji; Miao, Jingqi</p> <p>2015-01-01</p> <p>We have made near-infrared (JHK {sub s}) imaging polarimetry of a <span class="hlt">bright</span>-rimmed cloud (SFO 74). The <span class="hlt">polarization</span> vector maps clearly show that the magnetic field in the layer just behind the <span class="hlt">bright</span> rim is running along the rim, quite different from its ambient magnetic field. The direction of the magnetic field just behind the tip rim is almost perpendicular to that of the incident UV radiation, and the magnetic field configuration appears to be symmetric as a whole with respect to the cloud symmetry axis. We estimated the column and number densities in the two regions (just inside and farmore » inside the tip rim) and then derived the magnetic field strength, applying the Chandrasekhar-Fermi method. The estimated magnetic field strength just inside the tip rim, ∼90 μG, is stronger than that far inside, ∼30 μG. This suggests that the magnetic field strength just inside the tip rim is enhanced by the UV-radiation-induced shock. The shock increases the density within the top layer around the tip and thus increases the strength of the magnetic field. The magnetic pressure seems to be comparable to the turbulent one just inside the tip rim, implying a significant contribution of the magnetic field to the total internal pressure. The mass-to-flux ratio was estimated to be close to the critical value just inside the tip rim. We speculate that the flat-topped <span class="hlt">bright</span> rim of SFO 74 could be formed by the magnetic field effect.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-GSFC_20171208_Archive_e002110.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-GSFC_20171208_Archive_e002110.html"><span><span class="hlt">Bright</span> Solar Flare</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2017-12-08</p> <p>A <span class="hlt">bright</span> solar flare is captured by the EIT 195Å instrument on 1998 May 2. A solar flare (a sudden, rapid, and intense variation in <span class="hlt">brightness</span>) occurs when magnetic energy that has built up in the solar atmosphere is suddenly released, launching material outward at millions of km per hour. The Sun’s magnetic fields tend to restrain each other and force the buildup of tremendous energy, like twisting rubber bands, so much that they eventually break. At some point, the magnetic lines of force merge and cancel in a process known as magnetic reconnection, causing plasma to forcefully escape from the Sun. Credit: NASA/GSFC/SOHO/ESA To learn more go to the SOHO website: sohowww.nascom.nasa.gov/home.html To learn more about NASA's Sun Earth Day go here: sunearthday.nasa.gov/2010/index.php</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790002500','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790002500"><span>A statistical technique for determining rainfall over land employing Nimbus-6 ESMR measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rodgers, E.; Siddalingaiah, H.; Chang, A. T. C.; Wilheit, T. T.</p> <p>1978-01-01</p> <p>At 37 GHz, the frequency at which the Nimbus 6 Electrically Scanning Microwave Radiometer (ESMR 6) measures upwelling radiance, it was shown theoretically that the atmospheric scattering and the relative independence on electromagnetic <span class="hlt">polarization</span> of the radiances emerging from hydrometers make it possible to monitor remotely active rainfall over land. In order to verify experimentally these theoretical findings and to develop an algorithm to monitor rainfall over land, the digitized ESMR 6 measurements were examined statistically. <span class="hlt">Horizontally</span> and vertically <span class="hlt">polarized</span> <span class="hlt">brightness</span> temperature pairs (TH, TV) from ESMR 6 were sampled for areas of rainfall over land as determined from the rain recording stations and the WSR 57 radar, and areas of wet and dry ground (whose thermodynamic temperatures were greater than 5 C) over the Southeastern United States. These three categories of <span class="hlt">brightness</span> temperatures were found to be significantly different in the sense that the chances that the mean vectors of any two populations coincided were less than 1 in 100.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..DMP.Q1100K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..DMP.Q1100K"><span>Dark-<span class="hlt">Bright</span> Soliton Dynamics Beyond the Mean-Field Approximation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Katsimiga, Garyfallia; Koutentakis, Georgios; Mistakidis, Simeon; Kevrekidis, Panagiotis; Schmelcher, Peter; Theory Group of Fundamental Processes in Quantum Physics Team</p> <p>2017-04-01</p> <p>The dynamics of dark <span class="hlt">bright</span> solitons beyond the mean-field approximation is investigated. We first examine the case of a single dark-<span class="hlt">bright</span> soliton and its oscillations within a parabolic trap. Subsequently, we move to the setting of collisions, comparing the mean-field approximation to that involving multiple orbitals in both the dark and the <span class="hlt">bright</span> component. Fragmentation is present and significantly affects the dynamics, especially in the case of slower solitons and in that of lower atom numbers. It is shown that the presence of fragmentation allows for bipartite entanglement between the distinguishable species. Most importantly the interplay between fragmentation and entanglement leads to the decay of each of the initial mean-field dark-<span class="hlt">bright</span> solitons into fast and slow fragmented dark-<span class="hlt">bright</span> structures. A variety of excitations including dark-<span class="hlt">bright</span> solitons in multiple (concurrently populated) orbitals is observed. Dark-antidark states and domain-wall-<span class="hlt">bright</span> soliton complexes can also be observed to arise spontaneously in the beyond mean-field dynamics. Deutsche Forschungsgemeinschaft (DFG) in the framework of the SFB 925 ``Light induced dynamics and control of correlated quantum systems''.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999AIPC..475..877S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999AIPC..475..877S"><span>A high-<span class="hlt">brightness</span>, electron-based source of <span class="hlt">polarized</span> photons and neutrons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spencer, J. E.</p> <p>1999-06-01</p> <p>A compact and comparatively inexpensive system that is practical for universities is described based on a low-energy, electron storage ring with at least one undulator based oscillator to store photons. If the oscillator cavity length is relativistically corrected to be an harmonic of the ring circumference (LC=βLRn/nB with nB the number of bunches), higher-energy, secondary photons from Compton backscattering may become significant. Then, besides synchrotron radiation from the ring dipoles and damping wigglers as well as undulator photons, there are frequency upshifted Compton photons and photoneutrons from low Q-value targets such as Beryllium (Qn=-1.66) or Deuterium (Qn=-2.22 MeV). For 100 MeV electron bunches, an adjustable-phase, planar, helical undulator can be made to produce circularly <span class="hlt">polarized</span> UV photons having a fundamental ɛγ1=11.1 eV. If these photons are stored in a multimode, hole-coupled resonator they produce a Compton endpoint energy up to ɛγ2=1.7 MeV. When incident on a Be conversion target these secondary photons make unmoderated, epithermal neutrons having mean energy ɛn=24.8±6.8 keV from the two-body reaction Be9+γ→n+Be8(→2α)with negligible, residual radioactivity. The system is shown in Fig. 1. When the target is unpolarized, one expects neutron rates of 1011 epithermal n/s for 1015 Comptons/s and a circulating current of 1 A with <span class="hlt">polarizations</span> PRHC(n⃗)=-0.5, PLHC(n⃗)=0.5, both with reduced flux, and PLin(n⃗)=0. With a 1 cm thick cylindrical tungsten sheath surrounding the Be to attenuate scattered photons exiting at 90° to the incident photons, there is a peak neutron flux of ≈109 epithermal n/s/cm2 cylindrically symmetric around the surface. No attempt was made to optimize this because there is still no accepted treatment protocol (dose rates or preferred neutron energy distribution). Although these factors depend on the individual case, several thousand BNCT treatments per year appear feasible. A potential clinical</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JGRD..11122311A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JGRD..11122311A"><span>Ozone decrease outside Arctic <span class="hlt">polar</span> vortex due to <span class="hlt">polar</span> vortex processing in 1997</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Akiyoshi, H.; Sugata, S.; Yoshiki, M.; Sugita, T.</p> <p>2006-11-01</p> <p>We examine the effect of <span class="hlt">polar</span> vortex processing on ozone concentrations outside the 1997 Arctic <span class="hlt">polar</span> vortex. The Arctic vortex in this year was well isolated, cold, and circumpolar, and it broke up unusually late. However, time threshold diagnostics (TTD) analysis using a middle vortex boundary defined by the first derivative of the equivalent latitude gradient of potential vorticity and calculations using the nudging chemical transport model (CTM) of the Center for Climate System Research/National Institute for Environmental Studies (CCSR/NIES) show that there were intermittently several relatively large transport events from the vortex to the outside region in the lower stratosphere, with timescales and spatial scales that can be resolved at T42 CTM <span class="hlt">horizontal</span> resolution (2.8° by 2.8° grid). These intermittent outflow events of <span class="hlt">polar</span> air are also identified in TTD analysis using an outer vortex boundary defined by the second derivative of potential vorticity and a boundary defined by the N2O concentration. These intermittent events had a significant effect on the ozone concentration outside the vortex near the boundary in this year. A CTM calculation with a <span class="hlt">polar</span> chemical ozone tracer shows that the effect on the ozone concentration outside the <span class="hlt">polar</span> vortex near the vortex boundary in the equivalent latitude band of 55°-65°N and 450 K is 0.3 ppmv (15-20% of the ozone concentration at this height) and that on the total ozone is 12-15 Dobson units (1 DU = 0.001 atm cm) (3-4% of the total ozone) by the end of April just before the final vortex breakup. The effect in the equivalent latitude band of 30°-60°N is much smaller, with a reduction of 2 DU at the end of March and 4 DU by the end of April (less than 1% of the total ozone). The effect is about the half if we use the inner boundary or a boundary of 73°N equivalent latitude for the <span class="hlt">polar</span> tracer calculations. The CTM calculations also show that these <span class="hlt">polar</span> vortex processing effects might be masked at</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5135713','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5135713"><span>A simple approach to spectrally resolved fluorescence and <span class="hlt">bright</span> field microscopy over select regions of interest</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dahlberg, Peter D.; Boughter, Christopher T.; Faruk, Nabil F.; Hong, Lu; Koh, Young Hoon; Reyer, Matthew A.; Sherani, Aiman; Hammond, Adam T.</p> <p>2016-01-01</p> <p>A standard wide field inverted microscope was converted to a spatially selective spectrally resolved microscope through the addition of a <span class="hlt">polarizing</span> beam splitter, a pair of <span class="hlt">polarizers</span>, an amplitude-mode liquid crystal-spatial light modulator, and a USB spectrometer. The instrument is capable of simultaneously imaging and acquiring spectra over user defined regions of interest. The microscope can also be operated in a <span class="hlt">bright</span>-field mode to acquire absorption spectra of micron scale objects. The utility of the instrument is demonstrated on three different samples. First, the instrument is used to resolve three differently labeled fluorescent beads in vitro. Second, the instrument is used to recover time dependent bleaching dynamics that have distinct spectral changes in the cyanobacteria, Synechococcus leopoliensis UTEX 625. Lastly, the technique is used to acquire the absorption spectra of CH3NH3PbBr3 perovskites and measure differences between nanocrystal films and micron scale crystals. PMID:27910631</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26191867','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26191867"><span>Interferometric characterization of the structured <span class="hlt">polarized</span> light beam produced by the conical refraction phenomenon.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Peinado, Alba; Turpin, Alex; Iemmi, Claudio; Márquez, Andrés; Kalkandjiev, Todor K; Mompart, Jordi; Campos, Juan</p> <p>2015-07-13</p> <p>The interest on the conical refraction (CR) phenomenon in biaxial crystals has revived in the last years due to its prospective for generating structured <span class="hlt">polarized</span> light beams, i.e. vector beams. While the intensity and the <span class="hlt">polarization</span> structure of the CR beams are well known, an accurate experimental study of their phase structure has not been yet carried out. We investigate the phase structure of the CR rings by means of a Mach-Zehnder interferometer while applying the phase-shifting interferometric technique to measure the phase at the focal plane. In general the two beams interfering correspond to different states of <span class="hlt">polarization</span> (SOP) which locally vary. To distinguish if there is an additional phase added to the geometrical one we have derived the appropriate theoretical expressions using the Jones matrix formalism. We demonstrate that the phase of the CR rings is equivalent to that one introduced by an azimuthally segmented <span class="hlt">polarizer</span> with CR-like <span class="hlt">polarization</span> distribution. Additionally, we obtain direct evidence that the Poggendorff dark ring is an annular singularity, with a π phase change between the inner and outer <span class="hlt">bright</span> rings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://rosap.ntl.bts.gov/view/dot/9222','DOTNTL'); return false;" href="https://rosap.ntl.bts.gov/view/dot/9222"><span><span class="hlt">Horizontal</span> Collision Avoidance Systems Study</span></a></p> <p><a target="_blank" href="http://ntlsearch.bts.gov/tris/index.do">DOT National Transportation Integrated Search</a></p> <p></p> <p>1973-12-01</p> <p>This report presents the results of an analytical study of the merits and mechanization requirements of <span class="hlt">horizontal</span> collision avoidance systems (CAS). The <span class="hlt">horizontal</span> and combined <span class="hlt">horizontal</span>/vertical maneuvers which provide adequate miss distance with ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1215438-control-polarization-vacuum-ultraviolet-high-gain-free-electron-laser','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1215438-control-polarization-vacuum-ultraviolet-high-gain-free-electron-laser"><span>Control of the <span class="hlt">polarization</span> of a vacuum-ultraviolet, high-gain, free-electron laser</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Allaria, Enrico; Diviacco, Bruno; Callegari, Carlo; ...</p> <p>2014-12-02</p> <p>The two single-pass, externally seeded free-electron lasers (FELs) of the FERMI user facility are designed around Apple-II-type undulators that can operate at arbitrary <span class="hlt">polarization</span> in the vacuum ultraviolet-to-soft x-ray spectral range. Furthermore, within each FEL tuning range, any output wavelength and <span class="hlt">polarization</span> can be set in less than a minute of routine operations. We report the first demonstration of the full output <span class="hlt">polarization</span> capabilities of FERMI FEL-1 in a campaign of experiments where the wavelength and nominal <span class="hlt">polarization</span> are set to a series of representative values, and the <span class="hlt">polarization</span> of the emitted intense pulses is thoroughly characterized by three independentmore » instruments and methods, expressly developed for the task. The measured radiation <span class="hlt">polarization</span> is consistently >90% and is not significantly spoiled by the transport optics; differing, relative transport losses for <span class="hlt">horizontal</span> and vertical <span class="hlt">polarization</span> become more prominent at longer wavelengths and lead to a non-negligible ellipticity for an originally circularly <span class="hlt">polarized</span> state. The results from the different polarimeter setups validate each other, allow a cross-calibration of the instruments, and constitute a benchmark for user experiments.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018PhRvA..97d3623K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018PhRvA..97d3623K"><span>Dark-<span class="hlt">bright</span> soliton pairs: Bifurcations and collisions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Katsimiga, G. C.; Kevrekidis, P. G.; Prinari, B.; Biondini, G.; Schmelcher, P.</p> <p>2018-04-01</p> <p>The statics, stability, and dynamical properties of dark-<span class="hlt">bright</span> soliton pairs are investigated here, motivated by applications in a homogeneous two-component repulsively interacting Bose-Einstein condensate. One of the intraspecies interaction coefficients is used as the relevant parameter controlling the deviation from the integrable Manakov limit. Two different families of stationary states are identified consisting of dark-<span class="hlt">bright</span> solitons that are either antisymmetric (out-of-phase) or asymmetric (mass imbalanced) with respect to their <span class="hlt">bright</span> soliton. Both of the above dark-<span class="hlt">bright</span> configurations coexist at the integrable limit of equal intra and interspecies repulsions and are degenerate in that limit. However, they are found to bifurcate from it in a transcritical bifurcation. This bifurcation interchanges the stability properties of the bound dark-<span class="hlt">bright</span> pairs rendering the antisymmetric states unstable and the asymmetric ones stable past the associated critical point (and vice versa before it). Finally, on the dynamical side, it is found that large kinetic energies and thus rapid soliton collisions are essentially unaffected by the intraspecies variation, while cases involving near equilibrium states or breathing dynamics are significantly modified under such a variation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JPCM...17S1415Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JPCM...17S1415Y"><span>Photo electron emission microscopy of <span class="hlt">polarity</span>-patterned materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, W.-C.; Rodriguez, B. J.; Gruverman, A.; Nemanich, R. J.</p> <p>2005-04-01</p> <p>This study presents variable photon energy photo electron emission microscopy (PEEM) of <span class="hlt">polarity</span>-patterned epitaxial GaN films, and ferroelectric LiNbO3 (LNO) single crystals and PbZrTiO3 (PZT) thin films. The photo electrons were excited with spontaneous emission from the tunable UV free electron laser (FEL) at Duke University. We report PEEM observation of <span class="hlt">polarity</span> contrast and measurement of the photothreshold of each <span class="hlt">polar</span> region of the materials. For a cleaned GaN film with laterally patterned Ga- and N-face <span class="hlt">polarities</span>, we found a higher photoelectric yield from the N-face regions compared with the Ga-face regions. Through the photon energy dependent contrast in the PEEM images of the surfaces, we can deduce that the threshold of the N-face region is less than ~4.9 eV while that of the Ga-face regions is greater than 6.3 eV. In both LNO and PZT, <span class="hlt">bright</span> emission was detected from the negatively poled domains, indicating that the emission threshold of the negative domain is lower than that of the positive domain. For LNO, the measured photothreshold was ~4.6 eV at the negative domain and ~6.2 eV at the positive domain, while for PZT, the threshold of the negative domain was less than 4.3 eV. Moreover, PEEM observation of the PZT surface at elevated temperatures displayed that the domain contrast disappeared near the Curie temperature of ~300 °C. The PEEM <span class="hlt">polarity</span> contrast of the <span class="hlt">polar</span> materials is discussed in terms of internal screening from free carriers and defects and the external screening due to adsorbed ions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013RAA....13.1255Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013RAA....13.1255Y"><span>Moon night sky <span class="hlt">brightness</span> simulation for the Xinglong station</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yao, Song; Zhang, Hao-Tong; Yuan, Hai-Long; Zhao, Yong-Heng; Dong, Yi-Qiao; Bai, Zhong-Rui; Deng, Li-Cai; Lei, Ya-Juan</p> <p>2013-10-01</p> <p>Using a sky <span class="hlt">brightness</span> monitor at the Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences, we collected data from 22 dark clear nights and 90 moon nights. We first measured the sky <span class="hlt">brightness</span> variation with time for dark nights and found a clear correlation between sky <span class="hlt">brightness</span> and human activity. Then with a modified sky <span class="hlt">brightness</span> model of moon nights and data from these nights, we derived the typical value for several important parameters in the model. With these results, we calculated the sky <span class="hlt">brightness</span> distribution under a given moon condition for the Xinglong station. Furthermore, we simulated the sky <span class="hlt">brightness</span> distribution of a moon night for a telescope with a 5° field of view (such as LAMOST). These simulations will be helpful for determining the limiting magnitude and exposure time, as well as planning the survey for LAMOST during moon nights.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050167018','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050167018"><span>Effects of Atmospheric Dust on Residual South <span class="hlt">Polar</span> Cap Stability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bonrv, B. P.; Bjorkman, J. E.; Hansen, G. B.; James, P. B.; Wolff, M. J.</p> <p>2005-01-01</p> <p>The Martian <span class="hlt">polar</span> caps have been studied from the time of Herschel. Neither <span class="hlt">polar</span> cap normally disappears in summer. The Residual North <span class="hlt">Polar</span> Cap (portion that remains through summer) is composed of a mixture of water ice and dust, and its interannual stability is due to its low sublimation rate at the summer temperatures in the North <span class="hlt">Polar</span> Region. The Residual South <span class="hlt">Polar</span> Cap (RSPC) is more enigmatic, surviving the relatively hot perihelic summer season despite being composed of much more volatile CO2. It is able to do so because of its unusually high albedo, which is larger than that of other <span class="hlt">bright</span> regions in the seasonal cap (e.g. Mountains of Mitchel). The proximity of the albedo of the RSPC to the critical albedo for stability raises the question of whether the RSPC exists in every Martian year. The ground based record is somewhat ambivalent. Douglass and Lowell reported that RSPC suddenly vanished at Ls=297deg in 1894 and did not reappear until Ls=0deg [1], and Kuiper reported that it disappeared in 1956 [2]; but both observations were questioned by contemporaries, who tended to attribute them to obscuring dust. Barker [3] reported a large amount of water vapor over the south <span class="hlt">polar</span> cap in 1969 that could be attributed to exposure of near surface water ice during partial removal of the CO2 in the RSPC in 1969.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JEI....23b3011W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JEI....23b3011W"><span>Color constancy using <span class="hlt">bright</span>-neutral pixels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Yanfang; Luo, Yupin</p> <p>2014-03-01</p> <p>An effective illuminant-estimation approach for color constancy is proposed. <span class="hlt">Bright</span> and near-neutral pixels are selected to jointly represent the illuminant color and utilized for illuminant estimation. To assess the representing capability of pixels, <span class="hlt">bright</span>-neutral strength (BNS) is proposed by combining pixel chroma and <span class="hlt">brightness</span>. Accordingly, a certain percentage of pixels with the largest BNS is selected to be the representative set. For every input image, a proper percentage value is determined via an iterative strategy by seeking the optimal color-corrected image. To compare various color-corrected images of an input image, image color-cast degree (ICCD) is devised using means and standard deviations of RGB channels. Experimental evaluation on standard real-world datasets validates the effectiveness of the proposed approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017npjQI...3....5S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017npjQI...3....5S"><span>A two-channel, spectrally degenerate <span class="hlt">polarization</span> entangled source on chip</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sansoni, Linda; Luo, Kai Hong; Eigner, Christof; Ricken, Raimund; Quiring, Viktor; Herrmann, Harald; Silberhorn, Christine</p> <p>2017-12-01</p> <p>Integrated optics provides the platform for the experimental implementation of highly complex and compact circuits for quantum information applications. In this context integrated waveguide sources represent a powerful resource for the generation of quantum states of light due to their high <span class="hlt">brightness</span> and stability. However, the confinement of the light in a single spatial mode limits the realization of multi-channel sources. Due to this challenge one of the most adopted sources in quantum information processes, i.e. a source which generates spectrally indistinguishable <span class="hlt">polarization</span> entangled photons in two different spatial modes, has not yet been realized in a fully integrated platform. Here we overcome this limitation by suitably engineering two periodically poled waveguides and an integrated <span class="hlt">polarization</span> splitter in lithium niobate. This source produces <span class="hlt">polarization</span> entangled states with fidelity of F = 0.973 ±0.003 and a test of Bell's inequality results in a violation larger than 14 standard deviations. It can work both in pulsed and continuous wave regime. This device represents a new step toward the implementation of fully integrated circuits for quantum information applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040112701&hterms=pacemaker&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpacemaker','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040112701&hterms=pacemaker&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpacemaker"><span>Dynamic resetting of the human circadian pacemaker by intermittent <span class="hlt">bright</span> light</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rimmer, D. W.; Boivin, D. B.; Shanahan, T. L.; Kronauer, R. E.; Duffy, J. F.; Czeisler, C. A.</p> <p>2000-01-01</p> <p>In humans, experimental studies of circadian resetting typically have been limited to lengthy episodes of exposure to continuous <span class="hlt">bright</span> light. To evaluate the time course of the human endogenous circadian pacemaker's resetting response to brief episodes of intermittent <span class="hlt">bright</span> light, we studied 16 subjects assigned to one of two intermittent lighting conditions in which the subjects were presented with intermittent episodes of <span class="hlt">bright</span>-light exposure at 25- or 90-min intervals. The effective duration of <span class="hlt">bright</span>-light exposure was 31% or 63% compared with a continuous 5-h <span class="hlt">bright</span>-light stimulus. Exposure to intermittent <span class="hlt">bright</span> light elicited almost as great a resetting response compared with 5 h of continuous <span class="hlt">bright</span> light. We conclude that exposure to intermittent <span class="hlt">bright</span> light produces robust phase shifts of the endogenous circadian pacemaker. Furthermore, these results demonstrate that humans, like other species, exhibit an enhanced sensitivity to the initial minutes of <span class="hlt">bright</span>-light exposure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19547213','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19547213"><span>Dark-<span class="hlt">bright</span> soliton pairs in nonlocal nonlinear media.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Yuan Yao; Lee, Ray-Kuang</p> <p>2007-07-09</p> <p>We study the formation of dark-<span class="hlt">bright</span> vector soliton pairs in nonlocal Kerr-type nonlinear medium. We show, by analytical analysis and direct numerical calculation, that in addition to stabilize of vector soliton pairs nonlocal nonlinearity also helps to reduce the threshold power for forming a guided <span class="hlt">bright</span> soliton. With help of the nonlocality, it is expected that the observation of dark-<span class="hlt">bright</span> vector soliton pairs in experiments becomes more workable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JASTP.167...66B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JASTP.167...66B"><span>Making limb and nadir measurements comparable: A common volume study of PMC <span class="hlt">brightness</span> observed by Odin OSIRIS and AIM CIPS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benze, Susanne; Gumbel, Jörg; Randall, Cora E.; Karlsson, Bodil; Hultgren, Kristoffer; Lumpe, Jerry D.; Baumgarten, Gerd</p> <p>2018-01-01</p> <p>Combining limb and nadir satellite observations of <span class="hlt">Polar</span> Mesospheric Clouds (PMCs) has long been recognized as problematic due to differences in observation geometry, scattering conditions, and retrieval approaches. This study offers a method of comparing PMC <span class="hlt">brightness</span> observations from the nadir-viewing Aeronomy of Ice in the Mesosphere (AIM) Cloud Imaging and Particle Size (CIPS) instrument and the limb-viewing Odin Optical Spectrograph and InfraRed Imaging System (OSIRIS). OSIRIS and CIPS measurements are made comparable by defining a common volume for overlapping OSIRIS and CIPS observations for two northern hemisphere (NH) PMC seasons: NH08 and NH09. We define a scattering intensity quantity that is suitable for either nadir or limb observations and for different scattering conditions. A known CIPS bias is applied, differences in instrument sensitivity are analyzed and taken into account, and effects of cloud inhomogeneity and common volume definition on the comparison are discussed. Not accounting for instrument sensitivity differences or inhomogeneities in the PMC field, the mean relative difference in cloud <span class="hlt">brightness</span> (CIPS - OSIRIS) is -102 ± 55%. The differences are largest for coincidences with very inhomogeneous clouds that are dominated by pixels that CIPS reports as non-cloud points. Removing these coincidences, the mean relative difference in cloud <span class="hlt">brightness</span> reduces to -6 ± 14%. The correlation coefficient between the CIPS and OSIRIS measurements of PMC <span class="hlt">brightness</span> variations in space and time is remarkably high, at 0.94. Overall, the comparison shows excellent agreement despite different retrieval approaches and observation geometries.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012ACP....12.4143D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012ACP....12.4143D"><span>Lidar and radar measurements of the melting layer: observations of dark and <span class="hlt">bright</span> band phenomena</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Di Girolamo, P.; Summa, D.; Cacciani, M.; Norton, E. G.; Peters, G.; Dufournet, Y.</p> <p>2012-05-01</p> <p>Multi-wavelength lidar measurements in the melting layer revealing the presence of dark and <span class="hlt">bright</span> bands have been performed by the University of BASILicata Raman lidar system (BASIL) during a stratiform rain event. Simultaneously radar measurements have been also performed from the same site by the University of Hamburg cloud radar MIRA 36 (35.5 GHz), the University of Hamburg dual-<span class="hlt">polarization</span> micro rain radar (24.15 GHz) and the University of Manchester UHF wind profiler (1.29 GHz). Measurements from BASIL and the radars are illustrated and discussed in this paper for a specific case study on 23 July 2007 during the Convective and Orographically-induced Precipitation Study (COPS). Simulations of the lidar dark and <span class="hlt">bright</span> band based on the application of concentric/eccentric sphere Lorentz-Mie codes and a melting layer model are also provided. Lidar and radar measurements and model results are also compared with measurements from a disdrometer on ground and a two-dimensional cloud (2DC) probe on-board the ATR42 SAFIRE. Measurements and model results are found to confirm and support the conceptual microphysical/scattering model elaborated by Sassen et al. (2005).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5840641-horizontal-edna-miner','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5840641-horizontal-edna-miner"><span><span class="hlt">Horizontal</span> EDNA miner</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Justice, J.C.; Delli-Gatti, F.A.</p> <p>1985-12-03</p> <p>A mining machine is utilized for making original generally <span class="hlt">horizontal</span> bores in coal seams, and for enlarging preexisting bores. A single cutting head is mounted for rotation about a first <span class="hlt">horizontal</span> axis generally perpendicular to the dimension of elongation of the <span class="hlt">horizontal</span> bore, and is pivotal about a second <span class="hlt">horizontal</span> axis, parallel to the first axis, to change its cutting, vertical position within the bore. A non-rotatable body member, with side wall supports, is mounted posteriorly of the cutting head, and includes a conveyor mechanism and a power mechanism operatively connected to it. The machine can be sumped into amore » bore and then the cutting head rotated about the second axis to change the vertical position thereof, and then moved rearwardly, any cut material being continuously conveyed to the bore mouth by the conveyor mechanism. The amount of vertical movement during the pivoting action about the second axis is controlled in response to the automatic sensing of the thickness of the coal seam in which the machine operates.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920040060&hterms=textural+features&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dtextural%2Bfeatures','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920040060&hterms=textural+features&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dtextural%2Bfeatures"><span>Pattern recognition analysis of <span class="hlt">polar</span> clouds during summer and winter</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ebert, Elizabeth E.</p> <p>1992-01-01</p> <p>A pattern recognition algorithm is demonstrated which classifies eighteen surface and cloud types in high-latitude AVHRR imagery based on several spectral and textural features, then estimates the cloud properties (fractional coverage, albedo, and <span class="hlt">brightness</span> temperature) using a hybrid histogram and spatial coherence technique. The summertime version of the algorithm uses both visible and infrared data (AVHRR channels 1-4), while the wintertime version uses only infrared data (AVHRR channels 3-5). Three days of low-resolution AVHRR imagery from the Arctic and Antarctic during January and July 1984 were analyzed for cloud type and fractional coverage. The analysis showed significant amounts of high cloudiness in the Arctic during one day in winter. The Antarctic summer scene was characterized by heavy cloud cover in the southern ocean and relatively clear conditions in the continental interior. A large region of extremely low <span class="hlt">brightness</span> temperatures in East Antarctica during winter suggests the presence of <span class="hlt">polar</span> stratospheric cloud.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870020588','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870020588"><span>Satellite-derived ice data sets no. 2: Arctic monthly average microwave <span class="hlt">brightness</span> temperatures and sea ice concentrations, 1973-1976</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Parkinson, C. L.; Comiso, J. C.; Zwally, H. J.</p> <p>1987-01-01</p> <p>A summary data set for four years (mid 70's) of Arctic sea ice conditions is available on magnetic tape. The data include monthly and yearly averaged Nimbus 5 electrically scanning microwave radiometer (ESMR) <span class="hlt">brightness</span> temperatures, an ice concentration parameter derived from the <span class="hlt">brightness</span> temperatures, monthly climatological surface air temperatures, and monthly climatological sea level pressures. All data matrices are applied to 293 by 293 grids that cover a <span class="hlt">polar</span> stereographic map enclosing the 50 deg N latitude circle. The grid size varies from about 32 X 32 km at the poles to about 28 X 28 km at 50 deg N. The ice concentration parameter is calculated assuming that the field of view contains only open water and first-year ice with an ice emissivity of 0.92. To account for the presence of multiyear ice, a nomogram is provided relating the ice concentration parameter, the total ice concentration, and the fraction of the ice cover which is multiyear ice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22130678-dense-optical-near-infrared-monitoring-cta-during-high-state-oister-detection-intra-night-orphan-polarized-flux-flare','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22130678-dense-optical-near-infrared-monitoring-cta-during-high-state-oister-detection-intra-night-orphan-polarized-flux-flare"><span>DENSE OPTICAL AND NEAR-INFRARED MONITORING OF CTA 102 DURING HIGH STATE IN 2012 WITH OISTER: DETECTION OF INTRA-NIGHT ''ORPHAN <span class="hlt">POLARIZED</span> FLUX FLARE''</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Itoh, Ryosuke; Fukazawa, Yasushi; Tanaka, Yasuyuki T.</p> <p>2013-05-10</p> <p>CTA 102, classified as a flat spectrum radio quasar at z = 1.037, produced an exceptionally <span class="hlt">bright</span> optical flare in 2012 September. Following the Fermi Large Area Telescope detection of enhanced {gamma}-ray activity, we closely monitored this source in the optical and near-infrared bands for the 10 subsequent nights using 12 telescopes in Japan and South Africa. On MJD 56197 (2012 September 27, four to five days after the peak of <span class="hlt">bright</span> {gamma}-ray flare), <span class="hlt">polarized</span> flux showed a transient increase, while total flux and <span class="hlt">polarization</span> angle (PA) remained almost constant during the ''orphan <span class="hlt">polarized</span>-flux flare.'' We also detected an intra-nightmore » and prominent flare on MJD 56202. The total and <span class="hlt">polarized</span> fluxes showed quite similar temporal variations, but the PA again remained constant during the flare. Interestingly, the PAs during the two flares were significantly different from the jet direction. The emergence of a new emission component with a high <span class="hlt">polarization</span> degree (PD) up to 40% would be responsible for the observed two flares, and such a high PD indicates the presence of a highly ordered magnetic field at the emission site. We argue that the well-ordered magnetic field and even the observed directions of the PA, which is grossly perpendicular to the jet, are reasonably accounted for by transverse shock(s) propagating down the jet.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170002426','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170002426"><span>Constraining the Depth of <span class="hlt">Polar</span> Ice Deposits and Evolution of Cold Traps on Mercury with Small Craters in Permanently Shadowed Regions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Deutsch, Ariel N.; Head, James W.; Neumann, Gregory A.; Chabot, Nancy L.</p> <p>2017-01-01</p> <p>Earth-based radar observations revealed highly reflective deposits at the poles of Mercury [e.g., 1], which collocate with permanently shadowed regions (PSRs) detected from both imagery and altimetry by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft [e.g., 2]. MESSENGER also measured higher hydrogen concentrations at the north <span class="hlt">polar</span> region, consistent with models for these deposits to be composed primarily of water ice [3]. Enigmatic to the characterization of ice deposits on Mercury is the thickness of these radar-<span class="hlt">bright</span> features. A current minimum bound of several meters exists from the radar measurements, which show no drop in the radar cross section between 13- and 70-cm wavelength observations [4, 5]. A maximum thickness of 300 m is based on the lack of any statistically significant difference between the height of craters that host radar-<span class="hlt">bright</span> deposits and those that do not [6]. More recently, this upper limit on the depth of a typical ice deposit has been lowered to approximately 150 m, in a study that found a mean excess thickness of 50 +/- 35 m of radar-<span class="hlt">bright</span> deposits for 6 craters [7]. Refining such a constraint permits the derivation of a volumetric estimate of the total <span class="hlt">polar</span> ice on Mercury, thus providing insight into possible sources of water ice on the planet. Here, we take a different approach to constrain the thickness of water-ice deposits. Permanently shadowed surfaces have been resolved in images acquired with the broadband filter on MESSENGER's wide-angle camera (WAC) using low levels of light scattered by crater walls and other topography [8]. These surfaces are not featureless and often host small craters (less than a few km in diameter). Here we utilize the presence of these small simple craters to constrain the thickness of the radar-<span class="hlt">bright</span> ice deposits on Mercury. Specifically, we compare estimated depths made from depth-to-diameter ratios and depths from individual Mercury Laser Altimeter (MLA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70037047','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70037047"><span>First high-resolution stratigraphic column of the Martian north <span class="hlt">polar</span> layered deposits</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Fishbaugh, K.E.; Hvidberg, C.S.; Byrne, S.; Russell, P.S.; Herkenhoff, K. E.; Winstrup, M.; Kirk, R.</p> <p>2010-01-01</p> <p>This study achieves the first high-spatial-resolution, layer-scale, measured stratigraphic column of the Martian north <span class="hlt">polar</span> layered deposits using a 1m-posting DEM. The marker beds found throughout the upper North <span class="hlt">Polar</span> Layered Deposits range in thickness from 1.6 m-16.0 m +/-1.4 m, and 6 of 13 marker beds are separated by ???25-35 m. Thin-layer sets have average layer separations of 1.6 m. These layer separations may account for the spectral-power-peaks found in previous <span class="hlt">brightness</span>-profile analyses. Marker-bed layer thicknesses show a weak trend of decreasing thickness with depth that we interpret to potentially be the result of a decreased accumulation rate in the past, for those layers. However, the stratigraphic column reveals that a simple rhythmic or bundled layer sequence is not immediately apparent throughout the column, implying that the relationship between <span class="hlt">polar</span> layer formation and cyclic climate forcing is quite complex. Copyright ?? 2010 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29726531','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29726531"><span>Wafer defect detection by a <span class="hlt">polarization</span>-insensitive external differential interference contrast module.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nativ, Amit; Feldman, Haim; Shaked, Natan T</p> <p>2018-05-01</p> <p>We present a system that is based on a new external, <span class="hlt">polarization</span>-insensitive differential interference contrast (DIC) module specifically adapted for detecting defects in semiconductor wafers. We obtained defect signal enhancement relative to the surrounding wafer pattern when compared with <span class="hlt">bright</span>-field imaging. The new DIC module proposed is based on a shearing interferometer that connects externally at the output port of an optical microscope and enables imaging thin samples, such as wafer defects. This module does not require <span class="hlt">polarization</span> optics (such as Wollaston or Nomarski prisms) and is insensitive to <span class="hlt">polarization</span>, unlike traditional DIC techniques. In addition, it provides full control of the DIC shear and orientation, which allows obtaining a differential phase image directly on the camera (with no further digital processing) while enhancing defect detection capabilities, even if the size of the defect is smaller than the resolution limit. Our technique has the potential of future integration into semiconductor production lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010GeoRL..37.7201F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010GeoRL..37.7201F"><span>First high-resolution stratigraphic column of the Martian north <span class="hlt">polar</span> layered deposits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fishbaugh, Kathryn E.; Hvidberg, Christine S.; Byrne, Shane; Russell, Patrick S.; Herkenhoff, Kenneth E.; Winstrup, Mai; Kirk, Randolph</p> <p>2010-04-01</p> <p>This study achieves the first high-spatial-resolution, layer-scale, measured stratigraphic column of the Martian north <span class="hlt">polar</span> layered deposits using a 1m-posting DEM. The marker beds found throughout the upper North <span class="hlt">Polar</span> Layered Deposits range in thickness from 1.6 m-16.0 m +/- 1.4 m, and 6 of 13 marker beds are separated by ˜25-35 m. Thin-layer sets have average layer separations of 1.6 m. These layer separations may account for the spectral-power-peaks found in previous <span class="hlt">brightness</span>-profile analyses. Marker-bed layer thicknesses show a weak trend of decreasing thickness with depth that we interpret to potentially be the result of a decreased accumulation rate in the past, for those layers. However, the stratigraphic column reveals that a simple rhythmic or bundled layer sequence is not immediately apparent throughout the column, implying that the relationship between <span class="hlt">polar</span> layer formation and cyclic climate forcing is quite complex.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19800042207&hterms=Frost&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DFrost','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19800042207&hterms=Frost&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DFrost"><span>Mars south <span class="hlt">polar</span> spring and summer temperatures - A residual CO2 frost</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kieffer, H. H.</p> <p>1979-01-01</p> <p>Viking infrared thermal mapper (IRTM) energy measurements over the Mars south <span class="hlt">polar</span> cap throughout the Martian spring and summer revealed complex spatial, spectral, and temporal variations. High albedos did not directly correspond with low temperatures, and as the cap shrank to its residual position, it maintained large differences in <span class="hlt">brightness</span> temperature between the four IRTM surface-sensing bands at 7, 9, 11, and 20 microns. The late summer infrared spectral pattern can be matched by a surface consisting of CO2 frost with 20 micron emissivity of 0.8 and about 6% dark, warm soil under a dusty atmosphere of moderate infrared opacity and spectral properties similar to those measured for the Martian global dust storms. Low temperature, the absence of appreciable water vapor in the south <span class="hlt">polar</span> atmosphere, and the absence of surface warming expected if H2O were to become exposed, all imply that the residual south <span class="hlt">polar</span> cap was covered by solid CO2.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21850104','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21850104"><span>Central powering of the largest Lyman-α nebula is revealed by <span class="hlt">polarized</span> radiation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hayes, Matthew; Scarlata, Claudia; Siana, Brian</p> <p>2011-08-17</p> <p>High-redshift Lyman-α (Lyα) blobs are extended, luminous but rare structures that seem to be associated with the highest peaks in the matter density of the Universe. Their energy output and morphology are similar to those of powerful radio galaxies, but the source of the luminosity is unclear. Some blobs are associated with ultraviolet or infrared <span class="hlt">bright</span> galaxies, suggesting an extreme starburst event or accretion onto a central black hole. Another possibility is gas that is shock-excited by supernovae. But not all blobs are associated with galaxies, and these ones may instead be heated by gas falling into a dark-matter halo. The <span class="hlt">polarization</span> of the Lyα emission can in principle distinguish between these options, but a previous attempt to detect this signature returned a null detection. Here we report observations of <span class="hlt">polarized</span> Lyα from the blob LAB1 (ref. 2). Although the central region shows no measurable <span class="hlt">polarization</span>, the <span class="hlt">polarized</span> fraction (P) increases to ∼20 per cent at a radius of 45 kiloparsecs, forming an almost complete <span class="hlt">polarized</span> ring. The detection of <span class="hlt">polarized</span> radiation is inconsistent with the in situ production of Lyα photons, and we conclude that they must have been produced in the galaxies hosted within the nebula, and re-scattered by neutral hydrogen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007pahb.conf.....P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007pahb.conf.....P"><span>The Physics and Applications of High <span class="hlt">Brightness</span> Electron Beams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Palumbo, Luigi; Rosenzweig, J.; Serafini, Luca</p> <p>2007-09-01</p> <p> <span class="hlt">brightness</span> photoinjector / M. Ferrario, V. Fusco, M. Migliorati and L. Palumbo. Simulations of coherent synchroton radiation effects in electron machines / M. Migliorati, A, Schiavi and G. Dattoli. QFEL: A numerical code for multi-dimensional simulation of free electron lasers in the quantum regime / A. Schiavi ... [et al.]. First simulations results on laser pulse jitter and microbunching instability at Saprxino / M. Boscolo ... [et al.]. -- Working Group 4. Working group 4 summary: applications of high <span class="hlt">brightness</span> beams to advanced accelerators and light sources / M. Uesaka and A. Rossi. Study of transverse effects in the production of X-rays with free-electron laser based on an optical ondulator / A. Bacci ... [et al.]. Channeling projects at LNF: from crystal undulators to capillary waveguides / S.B. Dabagov ... [et al.]. Mono-Energetic electron generation and plasma diagnosis experiments in a laser plasma cathode / K. Kinoshita ... [et al.]. A high-density electron beam and quad-scan measurements at Pleiades Thompson X-ray source / J.K. Lim ... [et al.]. Laser pulse circulation system for compact monochromatic tunable hard X-ray source / H. Ogino ... [et al.]. Limits on production of narrow band photons from inverse compton scattering / J. Rosenzweig and O. Williams. Preliminary results from the UCLA/SLAC ultra-high gradient Cerenkov wakefield accelerator experiment / M.C. Thompson ... [et al.]. Status of the <span class="hlt">polarized</span> nonlinear inverse compton scattering experiment at UCLA / O. Williams... [et al.]. Coupling laser power into a slab-symmetric accelerator structure / R.B. Yoder and J.B. Rosenzweig.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JGR...10621917S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JGR...10621917S"><span>Upper mantle anisotropy from long-period P <span class="hlt">polarization</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schulte-Pelkum, Vera; Masters, Guy; Shearer, Peter M.</p> <p>2001-10-01</p> <p>We introduce a method to infer upper mantle azimuthal anisotropy from the <span class="hlt">polarization</span>, i.e., the direction of particle motion, of teleseismic long-period P onsets. The <span class="hlt">horizontal</span> <span class="hlt">polarization</span> of the initial P particle motion can deviate by >10° from the great circle azimuth from station to source despite a high degree of linearity of motion. Recent global isotropic three-dimensional mantle models predict effects that are an order of magnitude smaller than our observations. Stations within regional distances of each other show consistent azimuthal deviation patterns, while the deviations seem to be independent of source depth and near-source structure. We demonstrate that despite this receiver-side spatial coherence, our <span class="hlt">polarization</span> data cannot be fit by a large-scale joint inversion for whole mantle structure. However, they can be reproduced by azimuthal anisotropy in the upper mantle and crust. Modeling with an anisotropic reflectivity code provides bounds on the magnitude and depth range of the anisotropy manifested in our data. Our method senses anisotropy within one wavelength (250 km) under the receiver. We compare our inferred fast directions of anisotropy to those obtained from Pn travel times and SKS splitting. The results of the comparison are consistent with azimuthal anisotropy situated in the uppermost mantle, with SKS results deviating from Pn and Ppol in some regions with probable additional deeper anisotropy. Generally, our fast directions are consistent with anisotropic alignment due to lithospheric deformation in tectonically active regions and to absolute plate motion in shield areas. Our data provide valuable additional constraints in regions where discrepancies between results from different methods exist since the effect we observe is local rather than cumulative as in the case of travel time anisotropy and shear wave splitting. Additionally, our measurements allow us to identify stations with incorrectly oriented <span class="hlt">horizontal</span> components.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100028440&hterms=convection&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dconvection','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100028440&hterms=convection&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dconvection"><span>Mobile Lid Convection Beneath Enceladus' South <span class="hlt">Polar</span> Terrain</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Barr, Amy C.</p> <p>2008-01-01</p> <p>Enceladus' south <span class="hlt">polar</span> region has a large heat flux, 55-110 milliwatts per square meter (or higher), that is spatially associated with cryovolcanic and tectonic activity. Tidal dissipation and vigorous convection in the underlying ice shell are possible sources of heat; however, prior predictions of the heat flux carried by stagnant lid convection range from F(sub conv) 15 to 30 milliwatts per square meter, too low to explain the observed heat flux. The high heat flux and increased cryovolcanic and tectonic activity suggest that near-surface ice in the region has become rheologically and mechanically weakened enough to permit convective plumes to reach close to the surface. If the yield strength of Enceladus' lithosphere is less than 1-10 kPa, convection may instead occur in the mobile lid" regime, which is characterized by large heat fluxes and large <span class="hlt">horizontal</span> velocities in the near-surface ice. I show that model ice shells with effective surface viscosities between 10(exp 16) and 10(exp 17) Pa s and basal viscosities between 10(exp 13) and 10(exp 15) Pa s have convective heat fluxes comparable to that observed by the Cassini Composite Infrared Spectrometer. If this style of convection is occurring, the south <span class="hlt">polar</span> terrain should be spreading <span class="hlt">horizontally</span> with v1-10 millimeter per year and should be resurfaced in 0.1-10 Ma. On the basis of Cassini imaging data, the south <span class="hlt">polar</span> terrain is 0.5 Ma old, consistent with the mobile lid hypothesis. Maxwell viscoelastic tidal dissipation in such ice shells is not capable of generating enough heat to balance convective heat transport. However, tidal heat may also be generated in the near-surface along faults as suggested by Nimmo et al. and/or viscous dissipation within the ice shell may occur by other processes not accounted for by the canonical Maxwell dissipation model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018ATel11615....1F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018ATel11615....1F"><span><span class="hlt">Bright</span> ZTF transients</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fremling, C.; Kulkarni, S. R.; Taggart, K.; Perley, D.</p> <p>2018-05-01</p> <p>As a part of ongoing commissioning of the Zwicky Transient Facility (ZTF; ATel #11266) Alert Infrastructure, here we report <span class="hlt">bright</span> probable supernovae identified in the raw alert stream resulting from the public ZTF Northern Sky Survey ("Celestial Cinematagrophy"; see Bellm & Kulkarni, Nature Astronomy 1, 71, 2017).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29229952','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29229952"><span>Ultra-<span class="hlt">bright</span> γ-ray emission and dense positron production from two laser-driven colliding foils.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Han-Zhen; Yu, Tong-Pu; Liu, Jin-Jin; Yin, Yan; Zhu, Xing-Long; Capdessus, Remi; Pegoraro, Francesco; Sheng, Zheng-Ming; McKenna, Paul; Shao, Fu-Qiu</p> <p>2017-12-11</p> <p>Matter can be transferred into energy and the opposite transformation is also possible by use of high-power lasers. A laser pulse in plasma can convert its energy into γ-rays and then e - e + pairs via the multi-photon Breit-Wheeler process. Production of dense positrons at GeV energies is very challenging since extremely high laser intensity ~10 24  Wcm -2 is required. Here we propose an all-optical scheme for ultra-<span class="hlt">bright</span> γ-ray emission and dense positron production with lasers at intensity of 10 22-23  Wcm -2 . By irradiating two colliding elliptically-<span class="hlt">polarized</span> lasers onto two diamondlike carbon foils, electrons in the focal region of one foil are rapidly accelerated by the laser radiation pressure and interact with the other intense laser pulse which penetrates through the second foil due to relativistically induced foil transparency. This symmetric configuration enables efficient Compton back-scattering and results in ultra-<span class="hlt">bright</span> γ-photon emission with <span class="hlt">brightness</span> of ~10 25 photons/s/mm 2 /mrad 2 /0.1%BW at 15 MeV and intensity of 5 × 10 23  Wcm -2 . Our first three-dimensional simulation with quantum-electrodynamics incorporated shows that a GeV positron beam with density of 2.5 × 10 22 cm -3 and flux of 1.6 × 10 10 /shot is achieved. Collective effects of the pair plasma may be also triggered, offering a window on investigating laboratory astrophysics at PW laser facilities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA02300.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA02300.html"><span>Defrosting <span class="hlt">Polar</span> Dunes--"They Look Like Bushes!"</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2000-05-26</p> <p>"They look like bushes!" That's what almost everyone says when they see the dark features found in pictures taken of sand dunes in the <span class="hlt">polar</span> regions as they are beginning to defrost after a long, cold winter. It is hard to escape the fact that, at first glance, these images acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) over both <span class="hlt">polar</span> regions during the spring and summer seasons, do indeed resemble aerial photographs of sand dune fields on Earth -- complete with vegetation growing on and around them! Of course, this is not what the features are, as we describe below and in related picture captions. Still, don't they look like vegetation to you? Shown here are two views of the same MGS MOC image. On the left is the full scene, on the right is an expanded view of a portion of the scene on the left. The <span class="hlt">bright</span>, smooth surfaces that are dotted with occasional, nearly triangular dark spots are sand dunes covered by winter frost. The MGS MOC has been used over the past several months (April-August 1999) to monitor dark spots as they form and evolve on <span class="hlt">polar</span> dune surfaces. The dark spots typically appear first along the lower margins of a dune -- similar to the position of bushes and tufts of grass that occur in and among some sand dunes on Earth. Because the martian air pressure is very low -- 100 times lower than at Sea Level on Earth -- ice on Mars does not melt and become liquid when it warms up. Instead, ice sublimes -- that is, it changes directly from solid to gas, just as "dry ice" does on Earth. As <span class="hlt">polar</span> dunes emerge from the months-long winter night, and first become exposed to sunlight, the <span class="hlt">bright</span> winter frost and snow begins to sublime. This process is not uniform everywhere on a dune, but begins in small spots and then over several months it spreads until the entire dune is spotted like a leopard. The early stages of the defrosting process -- as in the picture shown here -- give the impression that something is "growing" on the dunes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.A42A..02Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.A42A..02Z"><span>How well do Reanalysis represent <span class="hlt">polar</span> lows?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zappa, G.; Shaffrey, L.; Hodges, K.</p> <p>2013-12-01</p> <p><span class="hlt">Polar</span> lows are intense maritime mesocyclones forming at high latitudes during <span class="hlt">polar</span> air outbreaks. The associated high surface winds can be an important cause of coastal damage.They also seem to play a relevant role in the climate system by modulating the oceanic surface heat fluxes. This creates strong interest in understanding whether modern reanalysis datasets are able to represent <span class="hlt">polar</span> lows, as well as how their representation may be sensitive to the model resolution. In this talk we investigate how ERA-Interim reanalysis represents the <span class="hlt">polar</span> lows identified by the Norwegian meteorological services and listed in the STARS (Combination of Sea Surface Temperature and AltimeteR Synergy) dataset for the period 2002-2011. The sensitivity to resolution is explored by comparing ERA-Interim to the ECMWF operational analyses (2008-2011), which have three times higher <span class="hlt">horizontal</span> resolution compared to ERA-Interim. We show that ERAI-Interim has excellent ability to capture the observed <span class="hlt">polar</span> lows events with up to 90% of the observed events being found in the reanalysis. However, ERA-Interim tends to have <span class="hlt">polar</span> lows of weaker dynamical intensity, in terms of both winds and vorticity, and with less spatial structure than in the ECMWF operational analyses (See Fig 1). Furthermore, we apply an objective feature tracking algorithm to the 3 hourly vorticity at 850 hPa with constraints on vorticity intensity and atmospheric static stability to objectively identify <span class="hlt">polar</span> lows in the ERA-Interim reanalysis. We show that for the stronger <span class="hlt">polar</span> lows the objective climatology shows good agreement with the STARS dataset over the 2002-2011 period. This allows us to extend the <span class="hlt">polar</span> lows climatology over the whole ERA Interim period. Differences with another reanalysis product (NCEP-CFSR) will be also discussed. Fig 1: Composite of the tangential wind speed at 925 hPa for 34 <span class="hlt">polar</span> lows observed in the Norwegian sea between 2008-2010 as represented by the ERA-Interim reanalysis (left</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT........35B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT........35B"><span>Creation of vector beams from a <span class="hlt">polarization</span> diffraction grating using a programmable liquid crystal spatial light modulator and a q-plate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Badham, Katherine Emily</p> <p></p> <p>This thesis presents the ability of complete <span class="hlt">polarization</span> control of light to create a <span class="hlt">polarization</span> diffraction grating (PDG). This system has the ability to create diffracted light with each order having a separate high-order <span class="hlt">polarization</span> state in one location on the optical axis. First, an external Excel program is used to create a grating phase profile from userspecified target diffraction orders. High-order vector beams in this PDG are created using a combination of two devices---a liquid crystal spatial light modulator (LC-SLM) manufactured by Seiko Epson, and a tunable q -plate from Citizen Holdings Co. The transmissive SLM is positioned in an optical setup with a reflective architecture allowing control over both the <span class="hlt">horizontal</span> and vertical components of the laser beam. The SLM has its LC director oriented vertically only affecting the vertically <span class="hlt">polarized</span> state, however, the optical setup allows modulation of both vertical and <span class="hlt">horizontal</span> components by the use of a quarter-wave plate (QWP) and a mirror to rotate the <span class="hlt">polarizations</span> 90 degrees. Each half of the SLM is encoded with an anisotropic phase-only diffraction grating which are superimposed to create a select number of orders with the desired <span class="hlt">polarization</span> states and equally distributed intensity. The technique of polarimetry is used to confirm the <span class="hlt">polarization</span> state of each diffraction order. The q-plate is an inhomogeneous birefringent waveplate which has the ability to convert zero-order vector beams into first-order vector beams. The physical placement of this device into the system converts the orders with zero-order <span class="hlt">polarization</span> states to first-order <span class="hlt">polarization</span> states. The light vector patterns of each diffraction order confirm which first-order <span class="hlt">polarization</span> state of is produced. A specially made PDG sextuplicator is encoded onto the SLM to generate six diffraction orders with separate states of <span class="hlt">polarization</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhRvA..96f3404H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhRvA..96f3404H"><span>Generation of circularly <span class="hlt">polarized</span> XUV and soft-x-ray high-order harmonics by homonuclear and heteronuclear diatomic molecules subject to bichromatic counter-rotating circularly <span class="hlt">polarized</span> intense laser fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heslar, John; Telnov, Dmitry A.; Chu, Shih-I.</p> <p>2017-12-01</p> <p>Recently, studies of <span class="hlt">bright</span> circularly <span class="hlt">polarized</span> high-harmonic beams from atoms in the soft-x-ray region as a source for x-ray magnetic circular dichroism measurement in a tabletop-scale setup have received considerable attention. In this paper, we address the problem with molecular targets and perform a detailed quantum study of H2 +, CO, and N2 molecules in bichromatic counter-rotating circularly <span class="hlt">polarized</span> laser fields where we adopt wavelengths (1300 and 790 nm) and intensities (2 ×1014W /cm2 ) reported in a recent experiment [Proc. Natl. Acad. Sci. USA 112, 14206 (2015), 10.1073/pnas.1519666112]. Our treatment of multiphoton processes in homonuclear and heteronuclear diatomic molecules is nonperturbative and based on the time-dependent density-functional theory for multielectron systems. The calculated radiation spectrum contains doublets of left and right circularly <span class="hlt">polarized</span> harmonics with high-energy photons in the XUV and soft-x-ray ranges. Our results reveal intriguing and substantially different nonlinear optical responses for homonuclear and heteronuclear diatomic molecules subject to circularly <span class="hlt">polarized</span> intense laser fields. We study in detail the below- and above-threshold harmonic regions and analyze the ellipticity and phase of the generated harmonic peaks.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=phi&pg=4&id=EJ838375','ERIC'); return false;" href="https://eric.ed.gov/?q=phi&pg=4&id=EJ838375"><span>Does Stevens's Power Law for <span class="hlt">Brightness</span> Extend to Perceptual <span class="hlt">Brightness</span> Averaging?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Bauer, Ben</p> <p>2009-01-01</p> <p>Stevens's power law ([Psi][infinity][Phi][beta]) captures the relationship between physical ([Phi]) and perceived ([Psi]) magnitude for many stimulus continua (e.g., luminance and <span class="hlt">brightness</span>, weight and heaviness, area and size). The exponent ([beta]) indicates whether perceptual magnitude grows more slowly than physical magnitude ([beta] less…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ChPhB..25l8102G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ChPhB..25l8102G"><span>Ultra-wideband circular-<span class="hlt">polarization</span> converter with micro-split Jerusalem-cross metasurfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Xi; Yu, Xing-Yang; Cao, Wei-Ping; Jiang, Yan-Nan; Yu, Xin-Hua</p> <p>2016-12-01</p> <p>An ultrathin micro-split Jerusalem-cross metasurface is proposed in this paper, which can efficiently convert the linear <span class="hlt">polarization</span> of electromagnetic (EM) wave into the circular <span class="hlt">polarization</span> in ultra-wideband. By symmetrically employing two micro-splits on the <span class="hlt">horizontal</span> arm (in the x direction) of the Jerusalem-cross structure, the bandwidth of the proposed device is significantly extended. Both simulated and experimental results show that the proposed metasurface is able to convert linearly <span class="hlt">polarized</span> waves into circularly <span class="hlt">polarized</span> waves in a frequency range from 12.4 GHz to 21 GHz, with an axis ratio better than 1 dB. The simulated results also show that such a broadband and high-performance are maintained over a wide range of incident angle. The presented <span class="hlt">polarization</span> converter can be used in a number of areas, such as spectroscopy and wireless communications. Project supported by the National Natural Science Foundation of China (Grant Nos. 61461016 and 61661012), the Natural Science Foundation of Guangxi Zhuang Autonomous Region, China (Grant Nos. 2014GXNSFAA118366, 2014GXNSFAA118283, and 2015jjBB7002), and the Innovation Project of Graduate Education of Guilin University of Electronic Technology, China (Grant No. 2016YJCX82).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatAs...1..612S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatAs...1..612S"><span>The nature of solar <span class="hlt">brightness</span> variations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shapiro, A. I.; Solanki, S. K.; Krivova, N. A.; Cameron, R. H.; Yeo, K. L.; Schmutz, W. K.</p> <p>2017-09-01</p> <p>Determining the sources of solar <span class="hlt">brightness</span> variations1,2, often referred to as solar noise3, is important because solar noise limits the detection of solar oscillations3, is one of the drivers of the Earth's climate system4,5 and is a prototype of stellar variability6,7—an important limiting factor for the detection of extrasolar planets. Here, we model the magnetic contribution to solar <span class="hlt">brightness</span> variability using high-cadence8,9 observations from the Solar Dynamics Observatory (SDO) and the Spectral And Total Irradiance REconstruction (SATIRE)10,11 model. The <span class="hlt">brightness</span> variations caused by the constantly evolving cellular granulation pattern on the solar surface were computed with the Max Planck Institute for Solar System Research (MPS)/University of Chicago Radiative Magnetohydrodynamics (MURaM)12 code. We found that the surface magnetic field and granulation can together precisely explain solar noise (that is, solar variability excluding oscillations) on timescales from minutes to decades, accounting for all timescales that have so far been resolved or covered by irradiance measurements. We demonstrate that no other sources of variability are required to explain the data. Recent measurements of Sun-like stars by the COnvection ROtation and planetary Transits (CoRoT)13 and Kepler14 missions uncovered <span class="hlt">brightness</span> variations similar to that of the Sun, but with a much wider variety of patterns15. Our finding that solar <span class="hlt">brightness</span> variations can be replicated in detail with just two well-known sources will greatly simplify future modelling of existing CoRoT and Kepler as well as anticipated Transiting Exoplanet Survey Satellite16 and PLAnetary Transits and Oscillations of stars (PLATO)17 data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950054383&hterms=Keegan&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DKeegan','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950054383&hterms=Keegan&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DKeegan"><span>Thermal and albedo mapping of the <span class="hlt">polar</span> regions of Mars using Viking thermal mapper observations: 2. South <span class="hlt">polar</span> region</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Paige, David A.; Keegan, Kenneth D.</p> <p>1994-01-01</p> <p>We present the first maps of the apparent thermal inertia and albedo of the south <span class="hlt">polar</span> region of Mars. The observations used to create these maps were acquired by the infrared thermal mapper (IRTM) instruments on the two Viking Orbiters over a 30-day period in 1977 during the Martian late southern summer season. The maps cover the region from 60 deg S to the south pole at a spatial resolution of 1 deg of latitude, thus completing the initial thermal mapping of the entire planet. The analysis and interpretation of these maps is aided by the results of a one-dimensional radiative convective model, which is used to calculate diurnal variations in surface and atmospheric temperatures, and <span class="hlt">brightness</span> temperatures at the top of the atmosphere for a range of assumptions concerning dust optical properties and dust optical depths. The maps show that apparent thermal inertias of bare ground regions decrease systematically from 60 deg S to the south pole. In unfrosted regions close to the south pole, apparent thermal inertias are among the lowest observed anywhere on the planet. On the south residual cap, apparent thermal inertias are very high due to the presence of CO2 frost. In most other regions of Mars, best fit apparent albedos based on thermal emission measurements are generally in good agreement with actual surface albedos based on broadband solar reflectance measurements. The one-dimensional atmospheric model calculations also predict anomalously cold <span class="hlt">brightness</span> temperatures close to the pole during late summer, and after considering a number of alternatives, it is concluded that the net surface cooling due to atmospheric dust is the best explanation for this phenomenon. The region of lowest apparent thermal inertia close to the pole, which includes the south <span class="hlt">polar</span> layered deposits, is interpreted to be mantled by a continuous layer of aeolian material that must be at least a few millimeters thick. The low thermal inertias mapped in the south <span class="hlt">polar</span> region imply an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...589A..46S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...589A..46S"><span>Are solar <span class="hlt">brightness</span> variations faculae- or spot-dominated?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shapiro, A. I.; Solanki, S. K.; Krivova, N. A.; Yeo, K. L.; Schmutz, W. K.</p> <p>2016-05-01</p> <p>Context. Regular spaceborne measurements have revealed that solar <span class="hlt">brightness</span> varies on multiple timescales, variations on timescales greater than a day being attributed to a surface magnetic field. Independently, ground-based and spaceborne measurements suggest that Sun-like stars show a similar, but significantly broader pattern of photometric variability. Aims: To understand whether the broader pattern of stellar variations is consistent with the solar paradigm, we assess relative contributions of faculae and spots to solar magnetically-driven <span class="hlt">brightness</span> variability. We investigate how the solar <span class="hlt">brightness</span> variability and its facular and spot contributions depend on the wavelength, timescale of variability, and position of the observer relative to the ecliptic plane. Methods: We performed calculations with the SATIRE model, which returns solar <span class="hlt">brightness</span> with daily cadence from solar disc area coverages of various magnetic features. We took coverages as seen by an Earth-based observer from full-disc SoHO/MDI and SDO/HMI data and projected them to mimic out-of-ecliptic viewing by an appropriate transformation. Results: Moving the observer away from the ecliptic plane increases the amplitude of 11-year variability as it would be seen in Strömgren (b + y)/2 photometry, but decreases the amplitude of the rotational <span class="hlt">brightness</span> variations as it would appear in Kepler and CoRoT passbands. The spot and facular contributions to the 11-year solar variability in the Strömgren (b + y)/2 photometry almost fully compensate each other so that the Sun appears anomalously quiet with respect to its stellar cohort. Such a compensation does not occur on the rotational timescale. Conclusions: The rotational solar <span class="hlt">brightness</span> variability as it would appear in the Kepler and CoRoT passbands from the ecliptic plane is spot-dominated, but the relative contribution of faculae increases for out-of-ecliptic viewing so that the apparent <span class="hlt">brightness</span> variations are faculae-dominated for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA08518&hterms=images+MODIS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dimages%2BMODIS','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA08518&hterms=images+MODIS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dimages%2BMODIS"><span>CloudSat Image of a <span class="hlt">Polar</span> Night Storm Near Antarctica</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2006-01-01</p> <p><p/> [figure removed for brevity, see original site] Figure 1 <p/> CloudSat image of a <span class="hlt">horizontal</span> cross-section of a <span class="hlt">polar</span> night storm near Antarctica. Until now, clouds have been hard to observe in <span class="hlt">polar</span> regions using remote sensing, particularly during the <span class="hlt">polar</span> winter or night season. The red colors are indicative of highly reflective particles such as water (rain) or ice crystals, while the blue indicates thinner clouds (such as cirrus). The flat green/blue lines across the bottom represent the ground signal. The vertical scale on the CloudSat Cloud Profiling Radar image is approximately 30 kilometers (19 miles). The blue line below the Cloud Profiling Radar image indicates that the data were taken over water; the brown line below the image indicates the relative elevation of the land surface. The inset image shows the CloudSat track relative to a Moderate Resolution Imaging Spectroradiometer (MODIS) infrared image taken at nearly the same time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22370490-rotation-optical-polarization-angle-associated-ray-flare-blazar-comae','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22370490-rotation-optical-polarization-angle-associated-ray-flare-blazar-comae"><span>Rotation of the optical <span class="hlt">polarization</span> angle associated with the 2008 γ-ray flare of blazar W Comae</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Sorcia, Marco; Benítez, Erika; Cabrera, José I.</p> <p>2014-10-10</p> <p>An R-band photopolarimetric variability analysis of the TeV <span class="hlt">bright</span> blazar W Comae between 2008 February 28 and 2013 May 17 is presented. The source showed a gradual tendency to decrease its mean flux level with a total change of 3 mJy. A maximum and minimum <span class="hlt">brightness</span> states in the R band of 14.25 ± 0.04 and 16.52 ± 0.1 mag, respectively, were observed, corresponding to a maximum variation of ΔF = 5.40 mJy. We estimated a minimum variability timescale of Δt = 3.3 days. A maximum <span class="hlt">polarization</span> degree P = 33.8% ± 1.6%, with a maximum variation of ΔP =more » 33.2%, was found. One of our main results is the detection of a large rotation of the <span class="hlt">polarization</span> angle from 78° to 315° (Δθ ∼ 237°) that coincides in time with the γ-ray flare observed in 2008 June. This result indicates that both optical and γ-ray emission regions could be co-spatial. During this flare, a correlation between the R-band flux and <span class="hlt">polarization</span> degree was found with a correlation coefficient of r {sub F} {sub –} {sub p} = 0.93 ± 0.11. From the Stokes parameters, we infer the existence of two optically thin synchrotron components that contribute to the <span class="hlt">polarized</span> flux. One of them is stable with a constant <span class="hlt">polarization</span> degree of 11%. Assuming a shock-in jet model during the 2008 flare, we estimated a maximum Doppler factor δ {sub D} ∼ 27 and a minimum of δ {sub D} ∼ 16; a minimum viewing angle of the jet ∼2.°0; and a magnetic field B ∼ 0.12 G.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoJI.207.1456C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoJI.207.1456C"><span>Teleseismic P-wave <span class="hlt">polarization</span> analysis at the Gräfenberg array</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cristiano, L.; Meier, T.; Krüger, F.; Keers, H.; Weidle, C.</p> <p>2016-12-01</p> <p>P-wave <span class="hlt">polarization</span> at the Gräfenberg array (GRF) in southern Germany is analysed in terms of azimuthal deviations and deviations in the vertical <span class="hlt">polarization</span> using 20 yr of broad-band recordings. An automated procedure for estimating P-wave <span class="hlt">polarization</span> parameters is suggested, based on the definition of a characteristic function, which evaluates the <span class="hlt">polarization</span> angles and their time variability as well as the amplitude, linearity and the signal-to-noise ratio of the P wave. P-wave <span class="hlt">polarization</span> at the GRF array is shown to depend mainly on frequency and backazimuth and only slightly on epicentral distance indicating depth-dependent local anisotropy and lateral heterogeneity. A harmonic analysis is applied to the azimuthal anomalies to analyse their periodicity as a function of backazimuth. The dominant periods are 180° and 360°. At low frequencies, between 0.03 and 0.1 Hz, the observed fast directions of azimuthal anisotropy inferred from the 180° periodicity are similar across the array. The average fast direction of azimuthal anisotropy at these frequencies is N20°E with an uncertainty of about 8° and is consistent with fast directions of Pn-wave propagation. Lateral velocity gradients determined for the low-frequency band are compatible with the Moho topography of the area. A more complex pattern in the <span class="hlt">horizontal</span> fast axis orientation beneath the GRF array is observed in the high-frequency band between 0.1 and 0.5 Hz, and is attributed to anisotropy in the upper crust. A remarkable rotation of the <span class="hlt">horizontal</span> fast axis orientation across the suture between the geological units Moldanubicum and Saxothuringicum is observed. In contrast, the 360° periodicity at high frequencies is rather consistent across the array and may either point to lower velocities in the upper crust towards the Bohemian Massif and/or to anisotropy dipping predominantly in the NE-SW direction. Altogether, P-wave <span class="hlt">polarization</span> analysis indicates the presence of layered lithospheric</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.P32B..05H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.P32B..05H"><span>HiRISE Observations of the <span class="hlt">Polar</span> Regions of Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herkenhoff, K. E.; Byrne, S.; Fishbaugh, K.; Russell, P.; Fortezzo, C.; McEwen, A.</p> <p>2008-12-01</p> <p>Digital elevation models (DEMs) derived from MRO HiRISE stereo images allow meter-scale topographic measurements in the north <span class="hlt">polar</span> layered deposits (NPLD) and distinction of slope vs. albedo effects on apparent <span class="hlt">brightness</span> of individual layers. HiRISE images do not show thin layers at the limit of resolution. Rather, fine layering, if it exists, appears to have been obscured by a more dust-rich mantling deposit which shows signs of eolian erosion and slumping. Stratigraphic sequences within the NPLD appear to be repeated within exposures observed by HiRISE, indicative of a record of periodic climate changes. Granular flows sourced from within the dark, basal unit are suggestive of, but do not require, the presence of water during their formation. Active mass wasting of frost and dust has been observed on steep NPLD scarps in early spring, similar to dry, loose snow avalanches on terrestrial slopes. <span class="hlt">Bright</span> and dark streaks are seen to evolve during the northern summer, evidence for active eolian redistribution of frost and perhaps dark (non- volatile) material. Relatively dark reddish patches observed within the north <span class="hlt">polar</span> residual cap during the summer indicate that the cap is very thin (<1 m) or more transparent in places. HiRISE images of exposures of the south <span class="hlt">polar</span> layered deposits (SPLD) show rectilinear fractures that are continuous across several layers and whose orientation is not affected by the topography of the exposure, suggesting that they were formed before erosion of the SPLD. They appear to extend laterally and vertically through the SPLD, like a joint set. While NPLD tectonism appears limited to isolated grabens, several faults have been observed by HiRISE in the SPLD, showing structural details including reverse fault splays that merge into bedding planes and possible evidence for thrust duplication. The faults may be the result of basal sliding (decollements) ramping into thrust faults near the margin of the SPLD.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970022376','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970022376"><span>Gravity Waves Near 300 km Over the <span class="hlt">Polar</span> Caps</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Johnson, F. S.; Hanson, W. B.; Hodges, R. R.; Coley, W. R.; Carignan, G. R.; Spencer, N. W.</p> <p>1995-01-01</p> <p>Distinctive wave forms in the distributions of vertical velocity and temperature of both neutral particles and ions are frequently observed from Dynamics Explorer 2 at altitudes above 250 km over the <span class="hlt">polar</span> caps. These are interpreted as being due to internal gravity waves propagating in the neutral atmosphere. The disturbances characterized by vertical velocity perturbations of the order of 100 m/s and <span class="hlt">horizontal</span> wave lengths along the satellite path of about 500 km. They often extend across the entire <span class="hlt">polar</span> cap. The associated temperature perturbations indicate that the <span class="hlt">horizontal</span> phase progression is from the nightside to the dayside. Vertical displacements are inferred to be of the order of 10 km and the periods to be of the order of 10(exp 3) s. The waves must propagate in the neutral atmosphere, but they usually are most clearly recognizable in the observations of ion vertical velocity and ion temperature. By combining the neutral pressure calculated from the observed neutral concentration and temperature with the vertical component of the neutral velocity, an upward energy flux of the order of 0.04 erg/sq cm-s at 250 km has been calculated, which is about equal to the maximum total solar ultraviolet heat input above that altitude. Upward energy fluxes calculated from observations on orbital passes at altitudes from 250 to 560 km indicate relatively little attenuation with altitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/21394430-characterization-millimeter-wave-polarization-centaurus-quad','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/21394430-characterization-millimeter-wave-polarization-centaurus-quad"><span>CHARACTERIZATION OF THE MILLIMETER-WAVE <span class="hlt">POLARIZATION</span> OF CENTAURUS A WITH QUaD</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Zemcov, M.; Bock, J.; Leitch, E.</p> <p>2010-02-20</p> <p>Centaurus (Cen) A represents one of the best candidates for an isolated, compact, highly <span class="hlt">polarized</span> source that is <span class="hlt">bright</span> at typical cosmic microwave background (CMB) experiment frequencies. We present measurements of the 4{sup 0} x 2{sup 0} region centered on Cen A with QUaD, a CMB polarimeter whose absolute <span class="hlt">polarization</span> angle is known to an accuracy of 0.{sup 0}5. Simulations are performed to assess the effect of misestimation of the instrumental parameters on the final measurement and systematic errors due to the field's background structure and temporal variability from Cen A's nuclear region are determined. The total (Q, U) ofmore » the inner lobe region is (1.00 +- 0.07(stat.) +- 0.04(sys.), - 1.72 +- 0.06 +- 0.05) Jy at 100 GHz and (0.80 +- 0.06 +- 0.06, - 1.40 +- 0.07 +- 0.08) Jy at 150 GHz, leading to <span class="hlt">polarization</span> angles and total errors of -30.{sup 0}0 +- 1.{sup 0}1 and -29.{sup 0}1 +- 1.{sup 0}7. These measurements will allow the use of Cen A as a <span class="hlt">polarized</span> calibration source for future millimeter experiments.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA02001&hterms=Frost&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DFrost','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA02001&hterms=Frost&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DFrost"><span><span class="hlt">Polar</span> Dunes In Summer Exhibit Frost Patches, Wind Streaks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1999-01-01</p> <p><p/>Mars Global Surveyor passes over the north <span class="hlt">polar</span> region of the red planet twelve times each day, offering many opportunities to observe how the <span class="hlt">polar</span> cap frosts and dunes are changing as the days goby. Right now it is summer in the north. This picture, taken the second week of April 1999, shows darks and dunes and remnant patches of <span class="hlt">bright</span> frost left over from the winter that ended in July 1998. Dark streaks indicate recent movement of sand. The picture covers an area only 1.4 kilometers (0.9 miles)across and is illuminated from the upper right. <p/>Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA13301.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA13301.html"><span><span class="hlt">Bright</span> Lights, Green City</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2010-07-28</p> <p>Two extremely <span class="hlt">bright</span> stars illuminate a greenish mist in this image from the new GLIMPSE360 survey from NASA Spitzer Space Telescope. The fog is comprised of hydrogen and carbon compounds called polycyclic aromatic hydrocarbons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24720603','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24720603"><span>p-GaN/n-ZnO heterojunction nanowires: optoelectronic properties and the role of interface <span class="hlt">polarity</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schuster, Fabian; Laumer, Bernhard; Zamani, Reza R; Magén, Cesar; Morante, Joan Ramon; Arbiol, Jordi; Stutzmann, Martin</p> <p>2014-05-27</p> <p>In this work, simulations of the electronic band structure of a p-GaN/n-ZnO heterointerface are presented. In contrast to homojunctions, an additional energy barrier due to the type-II band alignment hinders the flow of majority charge carriers in this heterojunction. Spontaneous <span class="hlt">polarization</span> and piezoelectricity are shown to additionally affect the band structure and the location of the recombination region. Proposed as potential UV-LEDs and laser diodes, p-GaN/n-ZnO heterojunction nanowires were fabricated by plasma-assisted molecular beam epitaxy (PAMBE). Atomic resolution annular <span class="hlt">bright</span> field scanning transmission electron microscopy (STEM) studies reveal an abrupt and defect-free heterointerface with a <span class="hlt">polarity</span> inversion from N-<span class="hlt">polar</span> GaN to Zn-<span class="hlt">polar</span> ZnO. Photoluminescence measurements show strong excitonic UV emission originating from the ZnO-side of the interface as well as stimulated emission in the case of optical pumping above a threshold of 55 kW/cm(2).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70032652','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70032652"><span>Seasonally active frost-dust avalanches on a north <span class="hlt">polar</span> scarp of Mars captured by HiRISE</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Russell, P.; Thomas, N.; Byrne, S.; Herkenhoff, K.; Fishbaugh, K.; Bridges, N.; Okubo, C.; Milazzo, M.; Daubar, I.; Hansen, C.; McEwen, A.</p> <p>2008-01-01</p> <p>North-<span class="hlt">polar</span> temporal monitoring by the High Resolution Imaging Science Experiment (HiRISE) orbiting Mars has discovered new, dramatic examples that Mars1 CO2-dominated seasonal volatile cycle is not limited to quiet deposition and sublimation of frost. In early northern martian spring, 2008, HiRISE captured several cases of CO2 frost and dust cascading down a steep, <span class="hlt">polar</span> scarp in discrete clouds. Analysis of morphology and process reveals these events to be similar to terrestrial powder avalanches, sluffs, and falls of loose, dry snow. Potential material sources and initiating mechanisms are discussed in the context of the Martian <span class="hlt">polar</span> spring environment and of additional, active, aeolian processes observed on the plateau above the scarp. The scarp events are identified as a trigger for mass wasting of <span class="hlt">bright</span>, fractured layers within the basal unit, and may indirectly influence the retreat rate of steep <span class="hlt">polar</span> scarps in competing ways. Copyright 2008 by the American Geophysical Union.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24516662','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24516662"><span><span class="hlt">Polarized</span> light sensitivity and orientation in coral reef fish post-larvae.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Berenshtein, Igal; Kiflawi, Moshe; Shashar, Nadav; Wieler, Uri; Agiv, Haim; Paris, Claire B</p> <p>2014-01-01</p> <p>Recent studies of the larvae of coral-reef fishes reveal that these tiny vertebrates possess remarkable swimming capabilities, as well as the ability to orient to olfactory, auditory, and visual cues. While navigation according to reef-generated chemicals and sounds can significantly affect dispersal, the effect is limited to the vicinity of the reef. Effective long-distance navigation requires at least one other capacity-the ability to maintain a bearing using, for example, a sun compass. Directional information in the sun's position can take the form of <span class="hlt">polarized</span>-light related cues (i.e., e-vector orientation and percent <span class="hlt">polarization</span>) and/or non-<span class="hlt">polarized</span>-light related cues (i.e., the direct image of the sun, and the <span class="hlt">brightness</span> and spectral gradients). We examined the response to both types of cues using commercially-reared post-larvae of the spine-cheeked anemonefish Premnas biaculeatus. Initial optomotor trials indicated that the post-larval stages are sensitive to linearly <span class="hlt">polarized</span> light. Swimming directionality was then tested using a Drifting In-Situ Chamber (DISC), which allowed us to examine the response of the post-larvae to natural variation in light conditions and to manipulated levels of light <span class="hlt">polarization</span>. Under natural light conditions, 28 of 29 post-larvae showed significant directional swimming (Rayleigh's test p<0.05, R = 0.74±0.23), but to no particular direction. Swimming directionality was positively affected by sky clarity (absence of clouds and haze), which explained 38% of the observed variation. Moreover, post-larvae swimming under fully <span class="hlt">polarized</span> light exhibited a distinct behavior of tracking the <span class="hlt">polarization</span> axis, as it rotated along with the DISC. This behavior was not observed under partially-<span class="hlt">polarized</span> illumination. We view these findings as an indication for the use of sun-related cues, and <span class="hlt">polarized</span> light signal in specific, by orienting coral-reef fish larvae.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3917914','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3917914"><span><span class="hlt">Polarized</span> Light Sensitivity and Orientation in Coral Reef Fish Post-Larvae</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Berenshtein, Igal; Kiflawi, Moshe; Shashar, Nadav; Wieler, Uri; Agiv, Haim; Paris, Claire B.</p> <p>2014-01-01</p> <p>Recent studies of the larvae of coral-reef fishes reveal that these tiny vertebrates possess remarkable swimming capabilities, as well as the ability to orient to olfactory, auditory, and visual cues. While navigation according to reef-generated chemicals and sounds can significantly affect dispersal, the effect is limited to the vicinity of the reef. Effective long-distance navigation requires at least one other capacity–the ability to maintain a bearing using, for example, a sun compass. Directional information in the sun’s position can take the form of <span class="hlt">polarized</span>-light related cues (i.e., e-vector orientation and percent <span class="hlt">polarization</span>) and/or non-<span class="hlt">polarized</span>-light related cues (i.e., the direct image of the sun, and the <span class="hlt">brightness</span> and spectral gradients). We examined the response to both types of cues using commercially-reared post-larvae of the spine-cheeked anemonefish Premnas biaculeatus. Initial optomotor trials indicated that the post-larval stages are sensitive to linearly <span class="hlt">polarized</span> light. Swimming directionality was then tested using a Drifting In-Situ Chamber (DISC), which allowed us to examine the response of the post-larvae to natural variation in light conditions and to manipulated levels of light <span class="hlt">polarization</span>. Under natural light conditions, 28 of 29 post-larvae showed significant directional swimming (Rayleigh’s test p<0.05, R = 0.74±0.23), but to no particular direction. Swimming directionality was positively affected by sky clarity (absence of clouds and haze), which explained 38% of the observed variation. Moreover, post-larvae swimming under fully <span class="hlt">polarized</span> light exhibited a distinct behavior of tracking the <span class="hlt">polarization</span> axis, as it rotated along with the DISC. This behavior was not observed under partially-<span class="hlt">polarized</span> illumination. We view these findings as an indication for the use of sun-related cues, and <span class="hlt">polarized</span> light signal in specific, by orienting coral-reef fish larvae. PMID:24516662</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Solar+AND+still&pg=2&id=ED525072','ERIC'); return false;" href="https://eric.ed.gov/?q=Solar+AND+still&pg=2&id=ED525072"><span>A Radiative Analysis of Angular Signatures and Oblique Radiance Retrievals over the <span class="hlt">Polar</span> Regions from the Multi-Angle Imaging Spectroradiometer</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wilson, Michael Jason</p> <p>2009-01-01</p> <p>This dissertation studies clouds over the <span class="hlt">polar</span> regions using the Multi-angle Imaging SpectroRadiometer (MISR) on-board EOS-Terra. Historically, low thin clouds have been problematic for satellite detection, because these clouds have similar <span class="hlt">brightness</span> and temperature properties to the surface they overlay. However, the oblique angles of MISR…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930010621','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930010621"><span>The <span class="hlt">polar</span> layered deposits on Mars: Inference from thermal inertia modeling and geologic studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Herkenhoff, K. E.</p> <p>1992-01-01</p> <p>It is widely believed that the Martian <span class="hlt">polar</span> layered deposits record climate variations over at least the last 10 to 100 m.y., but the details of the processes involved and their relative roles in layer formation and evolution remain obscure. Weathering of the Martian layered deposits by sublimation of water ice can account for the thermal inertias, water vapor abundances, and geologic relationships observed in the Martian <span class="hlt">polar</span> regions. The nonvolatile components of the layered deposits appears to consist mainly of <span class="hlt">bright</span> red dust, with small amounts of dark dust. Dark dust, perhaps similar to the magnetic material found at the Viking Lander sites, may preferentially form filamentary residue particles upon weathering of the deposits. Once eroded, these particles may saltate to form the dark dunes found in both <span class="hlt">polar</span> regions. This scenario for the origin and evolution of the dark material within the <span class="hlt">polar</span> layered deposits is consistent with the available imaging and thermal data. Further experimental measurements of the thermophysical properties of magnetite and maghemite under Martian conditions are needed to better test this hypothesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22370436-investigation-moving-structures-coronal-bright-point','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22370436-investigation-moving-structures-coronal-bright-point"><span>Investigation of the moving structures in a coronal <span class="hlt">bright</span> point</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ning, Zongjun; Guo, Yang, E-mail: ningzongjun@pmo.ac.cn</p> <p>2014-10-10</p> <p>We have explored the moving structures in a coronal <span class="hlt">bright</span> point (CBP) observed by the Solar Dynamic Observatory Atmospheric Imaging Assembly (AIA) on 2011 March 5. This CBP event has a lifetime of ∼20 minutes and is <span class="hlt">bright</span> with a curved shape along a magnetic loop connecting a pair of negative and positive fields. AIA imaging observations show that a lot of <span class="hlt">bright</span> structures are moving intermittently along the loop legs toward the two footpoints from the CBP <span class="hlt">brightness</span> core. Such moving <span class="hlt">bright</span> structures are clearly seen at AIA 304 Å. In order to analyze their features, the CBP ismore » cut along the motion direction with a curved slit which is wide enough to cover the bulk of the CBP. After integrating the flux along the slit width, we get the spacetime slices at nine AIA wavelengths. The oblique streaks starting from the edge of the CBP <span class="hlt">brightness</span> core are identified as moving <span class="hlt">bright</span> structures, especially on the derivative images of the <span class="hlt">brightness</span> spacetime slices. They seem to originate from the same position near the loop top. We find that these oblique streaks are bi-directional, simultaneous, symmetrical, and periodic. The average speed is about 380 km s{sup –1}, and the period is typically between 80 and 100 s. Nonlinear force-free field extrapolation shows the possibility that magnetic reconnection takes place during the CBP, and our findings indicate that these moving <span class="hlt">bright</span> structures could be the observational outflows after magnetic reconnection in the CBP.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24787595','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24787595"><span>Zernike analysis of all-sky night <span class="hlt">brightness</span> maps.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bará, Salvador; Nievas, Miguel; Sánchez de Miguel, Alejandro; Zamorano, Jaime</p> <p>2014-04-20</p> <p>All-sky night <span class="hlt">brightness</span> maps (calibrated images of the night sky with hemispherical field-of-view (FOV) taken at standard photometric bands) provide useful data to assess the light pollution levels at any ground site. We show that these maps can be efficiently described and analyzed using Zernike circle polynomials. The relevant image information can be compressed into a low-dimensional coefficients vector, giving an analytical expression for the sky <span class="hlt">brightness</span> and alleviating the effects of noise. Moreover, the Zernike expansions allow us to quantify in a straightforward way the average and zenithal sky <span class="hlt">brightness</span> and its variation across the FOV, providing a convenient framework to study the time course of these magnitudes. We apply this framework to analyze the results of a one-year campaign of night sky <span class="hlt">brightness</span> measurements made at the UCM observatory in Madrid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1183850','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1183850"><span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Huang, H.; Meot, F.; Ptitsyn, V.</p> <p></p> <p>RHIC has provided <span class="hlt">polarized</span> proton collisions from 31 GeV to 255 GeV in the past decade. To preserve <span class="hlt">polarization</span> through numerous depolarizing resonances through the whole accelerator chain, harmonic orbit correction, partial snakes, <span class="hlt">horizontal</span> tune jump system and full snakes have been used. In addition, close attentions have been paid to betatron tune control, orbit control and beam line alignment. The <span class="hlt">polarization</span> of 60% at 255 GeV has been delivered to experiments with 1.8×10 11 bunch intensity. For the eRHIC era, the beam <span class="hlt">brightness</span> has to be maintained to reach the desired luminosity. Since we only have one hadron ringmore » in the eRHIC era, existing spin rotator and snakes can be converted to six snake configuration for one hadron ring. With properly arranged six snakes, the <span class="hlt">polarization</span> can be maintained at 70% at 250 GeV. This paper summarizes the effort and plan to reach high <span class="hlt">polarization</span> with small emittance for eRHIC.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003ChPhy..12.1124L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003ChPhy..12.1124L"><span>Self-deflection of a <span class="hlt">bright</span> soliton in a separate <span class="hlt">bright</span>-dark spatial soliton pair based on a higher-order space charge field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Jin-Song; Hao, Zhong-Hua</p> <p>2003-10-01</p> <p>The self-deflection of a <span class="hlt">bright</span> solitary beam can be controlled by a dark solitary beam via a parametric coupling effect between the <span class="hlt">bright</span> and dark solitary beams in a separate <span class="hlt">bright</span>-dark spatial soliton pair supported by an unbiased series photorefractive crystal circuit. The spatial shift of the <span class="hlt">bright</span> solitary beam centre as a function of the input intensity of the dark solitary beam (hat rho) is investigated by taking into account the higher-order space charge field in the dynamics of the <span class="hlt">bright</span> solitary beam via both numerical and perturbation methods under steady-state conditions. The deflection amount (Deltas0), defined as the value of the spatial shift at the output surface of the crystal, is a monotonic and nonlinear function of hat rho. When hat rho is weak or strong enough, Deltas0 is, in fact, unchanged with hat rho, whereas Deltas0 increases or decreases monotonically with hat rho in a middle range of hat rho. The corresponding variation range (deltas) depends strongly on the value of the input intensity of the <span class="hlt">bright</span> solitary beam (r). There are some peak and valley values in the curve of deltas versus r under some conditions. When hat rho increases, the <span class="hlt">bright</span> solitary beam can scan toward both the direction same as and opposite to the crystal's c-axis. Whether the direction is the same as or opposite to the c-axis depends on the parameter values and configuration of the crystal circuit, as well as the value of r. Some potential applications are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820063972&hterms=sass&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsass','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820063972&hterms=sass&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsass"><span>Dependence of sea-surface microwave emissivity on friction velocity as derived from SMMR/SASS</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wentz, F. J.; Christensen, E. J.; Richardson, K. A.</p> <p>1981-01-01</p> <p>The sea-surface microwave emissivity is derived using SMMR <span class="hlt">brightness</span> temperatures and SASS inferred friction velocities for three North Pacific Seasat passes. The results show the emissivity increasing linearly with friction velocity with no obvious break between the foam-free and foam regimes up to a friction velocity of about 70 cm/sec (15 m/sec wind speed). For <span class="hlt">horizontal</span> <span class="hlt">polarization</span> the sensitivity of emissivity to friction velocity greatly increases with frequency, while for vertical <span class="hlt">polarization</span> the sensitivity is much less and is independent of frequency. This behavior is consistent with two-scale scattering theory. A limited amount of high friction velocity data above 70 cm/sec suggests an additional increase in emissivity due to whitecapping.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28490728','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28490728"><span><span class="hlt">Bright</span> nanoscale source of deterministic entangled photon pairs violating Bell's inequality.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jöns, Klaus D; Schweickert, Lucas; Versteegh, Marijn A M; Dalacu, Dan; Poole, Philip J; Gulinatti, Angelo; Giudice, Andrea; Zwiller, Val; Reimer, Michael E</p> <p>2017-05-10</p> <p>Global, secure quantum channels will require efficient distribution of entangled photons. Long distance, low-loss interconnects can only be realized using photons as quantum information carriers. However, a quantum light source combining both high qubit fidelity and on-demand <span class="hlt">bright</span> emission has proven elusive. Here, we show a <span class="hlt">bright</span> photonic nanostructure generating <span class="hlt">polarization</span>-entangled photon pairs that strongly violates Bell's inequality. A highly symmetric InAsP quantum dot generating entangled photons is encapsulated in a tapered nanowire waveguide to ensure directional emission and efficient light extraction. We collect ~200 kHz entangled photon pairs at the first lens under 80 MHz pulsed excitation, which is a 20 times enhancement as compared to a bare quantum dot without a photonic nanostructure. The performed Bell test using the Clauser-Horne-Shimony-Holt inequality reveals a clear violation (S CHSH  > 2) by up to 9.3 standard deviations. By using a novel quasi-resonant excitation scheme at the wurtzite InP nanowire resonance to reduce multi-photon emission, the entanglement fidelity (F = 0.817 ± 0.002) is further enhanced without temporal post-selection, allowing for the violation of Bell's inequality in the rectilinear-circular basis by 25 standard deviations. Our results on nanowire-based quantum light sources highlight their potential application in secure data communication utilizing measurement-device-independent quantum key distribution and quantum repeater protocols.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JAG...150..208Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JAG...150..208Z"><span>Applying TM-<span class="hlt">polarization</span> geoelectric exploration for study of low-contrast three-dimensional targets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zlobinskiy, Arkadiy; Mogilatov, Vladimir; Shishmarev, Roman</p> <p>2018-03-01</p> <p>With using new field and theoretical data, it has been shown that applying the electromagnetic field of transverse magnetic (TM) <span class="hlt">polarization</span> will give new opportunities for electrical prospecting by the method of transient processes. Only applying a pure field of the TM <span class="hlt">polarization</span> permits poor three-dimensional objects (required metalliferous deposits) to be revealed in a host <span class="hlt">horizontally</span>-layered medium. This position has good theoretical grounds. There is given the description of the transient electromagnetic method, that uses only the TM <span class="hlt">polarization</span> field. The pure TM mode is excited by a special source, which is termed as a circular electric dipole (CED). The results of three-dimensional simulation (by the method of finite elements) are discussed for three real geological situations for which applying electromagnetic fields of transverse electric (TE) and transverse magnetic (TM) <span class="hlt">polarizations</span> are compared. It has been shown that applying the TE mode gives no positive results, while applying the TM <span class="hlt">polarization</span> field permits the problem to be tackled. Finally, the results of field works are offered, which showed inefficiency of application of the classical TEM method, whereas in contrast, applying the field of TM <span class="hlt">polarization</span> makes it easy to identify the target.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017SPIE10426E..0IJ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017SPIE10426E..0IJ"><span>The effect of precipitation on measuring sea surface salinity from space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, Xuchen; Pan, Delu; He, Xianqiang; Wang, Difeng; Zhu, Qiankun; Gong, Fang</p> <p>2017-10-01</p> <p>The sea surface salinity (SSS) can be measured from space by using L-band (1.4 GHz) microwave radiometers. The L-band has been chosen for its sensitivity of <span class="hlt">brightness</span> temperature to the change of salinity. However, SSS remote sensing is still challenging due to the low sensitivity of <span class="hlt">brightness</span> temperature to SSS variation: for the vertical <span class="hlt">polarization</span>, the sensitivity is about 0.4 to 0.8 K/psu with different incident angles and sea surface temperature; for <span class="hlt">horizontal</span> <span class="hlt">polarization</span>, the sensitivity is about 0.2 to 0.6 K/psu. It means that we have to make radiometric measurements with accuracy better than 1K even for the best sensitivity of <span class="hlt">brightness</span> temperature to SSS. Therefore, in order to retrieve SSS, the measured <span class="hlt">brightness</span> temperature at the top of atmosphere (TOA) needs to be corrected for many sources of error. One main geophysical source of error comes from atmosphere. Currently, the atmospheric effect at L-band is usually corrected by absorption and emission model, which estimate the radiation absorbed and emitted by atmosphere. However, the radiation scattered by precipitation is neglected in absorption and emission models, which might be significant under heavy precipitation. In this paper, a vector radiative transfer model for coupled atmosphere and ocean systems with a rough surface is developed to simulate the <span class="hlt">brightness</span> temperature at the TOA under different precipitations. The model is based on the adding-doubling method, which includes oceanic emission and reflection, atmospheric absorption and scattering. For the ocean system with a rough surface, an empirical emission model established by Gabarro and the isotropic Cox-Munk wave model considering shadowing effect are used to simulate the emission and reflection of sea surface. For the atmospheric attenuation, it is divided into two parts: For the rain layer, a Marshall-Palmer distribution is used and the scattering properties of the hydrometeors are calculated by Mie theory (the scattering</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017RAA....17...37R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017RAA....17...37R"><span>Spatial Model of Sky <span class="hlt">Brightness</span> Magnitude in Langkawi Island, Malaysia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Redzuan Tahar, Mohammad; Kamarudin, Farahana; Umar, Roslan; Khairul Amri Kamarudin, Mohd; Sabri, Nor Hazmin; Ahmad, Karzaman; Rahim, Sobri Abdul; Sharul Aikal Baharim, Mohd</p> <p>2017-03-01</p> <p>Sky <span class="hlt">brightness</span> is an essential topic in the field of astronomy, especially for optical astronomical observations that need very clear and dark sky conditions. This study presents the spatial model of sky <span class="hlt">brightness</span> magnitude in Langkawi Island, Malaysia. Two types of Sky Quality Meter (SQM) manufactured by Unihedron are used to measure the sky <span class="hlt">brightness</span> on a moonless night (or when the Moon is below the horizon), when the sky is cloudless and the locations are at least 100 m from the nearest light source. The selected locations are marked by their GPS coordinates. The sky <span class="hlt">brightness</span> data obtained in this study were interpolated and analyzed using a Geographic Information System (GIS), thus producing a spatial model of sky <span class="hlt">brightness</span> that clearly shows the dark and <span class="hlt">bright</span> sky areas in Langkawi Island. Surprisingly, our results show the existence of a few dark sites nearby areas of high human activity. The sky <span class="hlt">brightness</span> of 21.45 mag arcsec{}-2 in the Johnson-Cousins V-band, as the average of sky <span class="hlt">brightness</span> equivalent to 2.8 × {10}-4{cd} {{{m}}}-2 over the entire island, is an indication that the island is, overall, still relatively dark. However, the amount of development taking place might reduce the number in the near future as the island is famous as a holiday destination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA15454.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA15454.html"><span>Apparent <span class="hlt">Brightness</span> and Topography Images of Vibidia Crater</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2012-03-09</p> <p>The left-hand image from NASA Dawn spacecraft shows the apparent <span class="hlt">brightness</span> of asteroid Vesta surface. The right-hand image is based on this apparent <span class="hlt">brightness</span> image, with a color-coded height representation of the topography overlain onto it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018BSRSL..87..365M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018BSRSL..87..365M"><span>Giant Low Surface <span class="hlt">Brightness</span> Galaxies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mishra, Alka; Kantharia, Nimisha G.; Das, Mousumi</p> <p>2018-04-01</p> <p>In this paper, we present radio observations of the giant low surface <span class="hlt">brightness</span> (LSB) galaxies made using the Giant Metrewave Radio Telescope (GMRT). LSB galaxies are generally large, dark matter dominated spirals that have low star formation efficiencies and large HI gas disks. Their properties suggest that they are less evolved compared to high surface <span class="hlt">brightness</span> galaxies. We present GMRT emission maps of LSB galaxies with an optically-identified active nucleus. Using our radio data and archival near-infrared (2MASS) and near-ultraviolet (GALEX) data, we studied morphology and star formation efficiencies in these galaxies. All the galaxies show radio continuum emission mostly associated with the centre of the galaxy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016A%26A...592A.114W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016A%26A...592A.114W"><span>X-ray and optical observations of four <span class="hlt">polars</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Worpel, H.; Schwope, A. D.; Granzer, T.; Reinsch, K.; Schwarz, R.; Traulsen, I.</p> <p>2016-08-01</p> <p>Aims: We investigate the temporal and spectral behaviour of four <span class="hlt">polar</span> cataclysmic variables from the infrared to X-ray regimes, refine our knowledge of the physical parameters of these systems at different accretion rates, and search for a possible excess of soft X-ray photons. Methods: We obtained and analysed four XMM-Newton X-ray observations of three of the sources, two of them discovered with the SDSS and one in the RASS. The X-ray data were complemented by optical photometric and spectroscopic observations and, for two sources, archival Swift observations. Results: SDSSJ032855.00+052254.2 was X-ray <span class="hlt">bright</span> in two XMM-Newton and two Swift observations, and shows transitions from high and low accretion states on a timescale of a few months. The source shows no significant soft excess. We measured the magnetic field strength at the main accreting pole to be 39 MG and the inclination to be 45° ≤ I ≤ 77°, and we refined the long-term ephemeris. SDSSJ133309.20+143706.9 was X-ray faint. We measured a faint phase X-ray flux and plasma temperature for this source, which seems to spend almost all of its time accreting at a low level. Its inclination is less than about 76°. 1RXSJ173006.4+033813 was X-ray <span class="hlt">bright</span> in the XMM-Newton observation. Its spectrum contained a modest soft blackbody component, not luminous enough to be considered a significant soft excess. We inferred a magnetic field strength at the main accreting pole of 20 to 25 MG, and that the inclination is less than 77° and probably less than 63°. V808 Aur, also known as CSS081231:J071126+440405, was X-ray faint in the Swift observation, but there is nonetheless strong evidence for <span class="hlt">bright</span> and faint phases in X-rays and perhaps in UV. Residual X-ray flux from the faint phase is difficult to explain by thermal emission from the white dwarf surface, or by accretion onto the second pole. We present a revised distance estimate of 250 pc. Conclusions: The three systems we were able to study in detail</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18480819','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18480819"><span>True <span class="hlt">polar</span> wander on Europa from global-scale small-circle depressions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schenk, Paul; Matsuyama, Isamu; Nimmo, Francis</p> <p>2008-05-15</p> <p>The tectonic patterns and stress history of Europa are exceedingly complex and many large-scale features remain unexplained. True <span class="hlt">polar</span> wander, involving reorientation of Europa's floating outer ice shell about the tidal axis with Jupiter, has been proposed as a possible explanation for some of the features. This mechanism is possible if the icy shell is latitudinally variable in thickness and decoupled from the rocky interior. It would impose high stress levels on the shell, leading to predictable fracture patterns. No satisfactory match to global-scale features has hitherto been found for <span class="hlt">polar</span> wander stress patterns. Here we describe broad arcuate troughs and depressions on Europa that do not fit other proposed stress mechanisms in their current position. Using imaging from three spacecraft, we have mapped two global-scale organized concentric antipodal sets of arcuate troughs up to hundreds of kilometres long and 300 m to approximately 1.5 km deep. An excellent match to these features is found with stresses caused by an episode of approximately 80 degrees true <span class="hlt">polar</span> wander. These depressions also appear to be geographically related to other large-scale <span class="hlt">bright</span> and dark lineaments, suggesting that many of Europa's tectonic patterns may also be related to true <span class="hlt">polar</span> wander.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3026033','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3026033"><span>Transmittance tuning by particle chain <span class="hlt">polarization</span> in electrowetting-driven droplets</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fan, Shih-Kang; Chiu, Cheng-Pu; Huang, Po-Wen</p> <p>2010-01-01</p> <p>A tiny droplet containing nano∕microparticles commonly handled in digital microfluidic lab-on-a-chip is regarded as a micro-optical component with tunable transmittance at programmable positions for the application of micro-opto-fluidic-systems. Cross-scale electric manipulations of droplets on a millimeter scale as well as suspended particles on a micrometer scale are demonstrated by electrowetting-on-dielectric (EWOD) and particle chain <span class="hlt">polarization</span>, respectively. By applying electric fields at proper frequency ranges, EWOD and <span class="hlt">polarization</span> can be selectively achieved in designed and fabricated parallel plate devices. At low frequencies, the applied signal generates EWOD to pump suspension droplets. The evenly dispersed particles reflect and∕or absorb the incident light to exhibit a reflective or dark droplet. When sufficiently high frequencies are used on to the nonsegmented parallel electrodes, a uniform electric field is established across the liquid to <span class="hlt">polarize</span> the dispersed neutral particles. The induced dipole moments attract the particles each other to form particle chains and increase the transmittance of the suspension, demonstrating a transmissive or <span class="hlt">bright</span> droplet. In addition, the reflectance of the droplet is measured at various frequencies with different amplitudes. PMID:21267088</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990103167&hterms=Jason+Moore&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DJason%2BMoore','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990103167&hterms=Jason+Moore&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DJason%2BMoore"><span>On Heating Large <span class="hlt">Bright</span> Coronal Loops by Magnetic Microexplosions at their Feet</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moore, Ronald L; Falconer, D. A.; Porter, Jason G.</p> <p>1999-01-01</p> <p>In previous work, by registering Yohkoh SXT coronal X-ray images with MSFC vector magnetograms, we found that: (1) many of the larger <span class="hlt">bright</span> coronal loops rooted at one or both ends in an active region are rooted around magnetic islands of included <span class="hlt">polarity</span>, (2) the core field encasing the neutral line encircling the island is strongly sheared, and (3) this sheared core field is the seat of frequent microflares. This suggests that the coronal heating in these extended <span class="hlt">bright</span> loops is driven by many small explosive releases of stored magnetic energy from the sheared core field at their feet, some of which magnetic microexplosions also produce the microflare heating in the core fields. In this paper, we show that this scenario is feasible in terms of the energy Abstract: required for the observed coronal heating and the magnetic energy available in the observed sheared core fields. In a representative active region, from the X-ray and vector field data, we estimate the coronal heating consumption by a selected typical large <span class="hlt">bright</span> loop, the coronal heating consumption by a typical microflare at the foot of this loop, the frequency of microflares at the foot, and the available magnetic energy in the microflaring core field. We find that: (1) the rate of magnetic energy release to power the microflares at the foot (approx. 6 x 10(ext 25)erg/s) is enough to also power the coronal heating in the body of the extended loop (approx. 2 x l0(exp 25 erg/s), and (2) there is enough stored magnetic energy in the sheared core field to sustain the microflaring and extended loop heating for about a day, which is a typical time for buildup of neutral-line magnetic shear in an active region. This work was funded by the Solar Physics Branch of NASA's Office of Space Science through the SR&T Program and the SEC Guest Investigator Program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA01829&hterms=parliament&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dparliament','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA01829&hterms=parliament&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dparliament"><span>Space Radar Image of Canberra, Australia</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1994-01-01</p> <p>Australia's capital city, Canberra, is shown in the center of this spaceborne radar image. Images like this can help urban planners assess land use patterns. Heavily developed areas appear in <span class="hlt">bright</span> patchwork patterns of orange, yellow and blue. Dense vegetation appears <span class="hlt">bright</span> green, while cleared areas appear in dark blue or black. Located in southeastern Australia, the site of Canberra was selected as the capital in 1901 as a geographic compromise between Sydney and Melbourne. Design and construction of the city began in 1908 under the supervision of American architect Walter Burley-Griffin. Lake Burley-Griffin is located above and to the left of the center of the image. The <span class="hlt">bright</span> pink area is the Parliament House. The city streets, lined with government buildings, radiate like spokes from the Parliament House. The <span class="hlt">bright</span> purple cross in the lower left corner of the image is a reflection from one of the large dish-shaped radio antennas at the Tidbinbilla, Canberra Deep Space Network Communication Complex, operated jointly by NASA and the Australian Space Office. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) on April 10, 1994, onboard the space shuttle Endeavour. The image is 28 kilometers by 25 kilometers (17 miles by 15 miles) and is centered at 35.35 degrees south latitude, 149.17 degrees east longitude. North is toward the upper left. The colors are assigned to different radar frequencies and <span class="hlt">polarizations</span> as follows: red is L-band, <span class="hlt">horizontally</span> transmitted and received; green is L-band, <span class="hlt">horizontally</span> transmitted and vertically received; and blue is C-band, <span class="hlt">horizontally</span> transmitted and vertically received. SIR-C/X-SAR, a joint mission of the German, Italian, and United States space agencies, is part of NASA's Office of Mission to Planet Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatAs...1..823H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatAs...1..823H"><span>Stunningly <span class="hlt">bright</span> optical emission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heinke, Craig O.</p> <p>2017-12-01</p> <p>The detection of <span class="hlt">bright</span>, rapid optical pulsations from pulsar PSR J1023+0038 have provided a surprise for researchers working on neutron stars. This discovery poses more questions than it answers and will spur on future work and instrumentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ACPD...1130949D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ACPD...1130949D"><span>Lidar and radar measurements of the melting layer in the frame of the Convective and Orographically-induced Precipitation Study: observations of dark and <span class="hlt">bright</span> band phenomena</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>di Girolamo, P.; Summa, D.; Bhawar, R.; di Iorio, T.; Norton, E. G.; Peters, G.; Dufournet, Y.</p> <p>2011-11-01</p> <p>During the Convective and Orographically-induced Precipitation Study (COPS), lidar dark and <span class="hlt">bright</span> bands were observed by the University of BASILicata Raman lidar system (BASIL) during several intensive (IOPs) and special (SOPs) observation periods (among others, 23 July, 15 August, and 17 August 2007). Lidar data were supported by measurements from the University of Hamburg cloud radar MIRA 36 (36 GHz), the University of Hamburg dual-<span class="hlt">polarization</span> micro rain radars (24.1 GHz) and the University of Manchester UHF wind profiler (1.29 GHz). Results from BASIL and the radars for 23 July 2007 are illustrated and discussed to support the comprehension of the microphysical and scattering processes responsible for the appearance of the lidar and radar dark and <span class="hlt">bright</span> bands. Simulations of the lidar dark and <span class="hlt">bright</span> band based on the application of concentric/eccentric sphere Lorentz-Mie codes and a melting layer model are also provided. Lidar and radar measurements and model results are also compared with measurements from a disdrometer on ground and a two-dimensional cloud (2DC) probe on-board the ATR42 SAFIRE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28612080','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28612080"><span>Color and emotion: effects of hue, saturation, and <span class="hlt">brightness</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wilms, Lisa; Oberfeld, Daniel</p> <p>2017-06-13</p> <p>Previous studies on emotional effects of color often failed to control all the three perceptual dimensions of color: hue, saturation, and <span class="hlt">brightness</span>. Here, we presented a three-dimensional space of chromatic colors by independently varying hue (blue, green, red), saturation (low, medium, high), and <span class="hlt">brightness</span> (dark, medium, <span class="hlt">bright</span>) in a factorial design. The 27 chromatic colors, plus 3 <span class="hlt">brightness</span>-matched achromatic colors, were presented via an LED display. Participants (N = 62) viewed each color for 30 s and then rated their current emotional state (valence and arousal). Skin conductance and heart rate were measured continuously. The emotion ratings showed that saturated and <span class="hlt">bright</span> colors were associated with higher arousal. The hue also had a significant effect on arousal, which increased from blue and green to red. The ratings of valence were the highest for saturated and <span class="hlt">bright</span> colors, and also depended on the hue. Several interaction effects of the three color dimensions were observed for both arousal and valence. For instance, the valence ratings were higher for blue than for the remaining hues, but only for highly saturated colors. Saturated and <span class="hlt">bright</span> colors caused significantly stronger skin conductance responses. Achromatic colors resulted in a short-term deceleration in the heart rate, while chromatic colors caused an acceleration. The results confirm that color stimuli have effects on the emotional state of the observer. These effects are not only determined by the hue of a color, as is often assumed, but by all the three color dimensions as well as their interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27835724','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27835724"><span>A Systematic Review of <span class="hlt">Bright</span> Light Therapy for Eating Disorders.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Beauchamp, Marshall T; Lundgren, Jennifer D</p> <p>2016-10-27</p> <p><span class="hlt">Bright</span> light therapy is a noninvasive biological intervention for disorders with nonnormative circadian features. Eating disorders, particularly those with binge-eating and night-eating features, have documented nonnormative circadian eating and mood patterns, suggesting that <span class="hlt">bright</span> light therapy may be an efficacious stand-alone or adjunctive intervention. The purpose of this systematic literature review, using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, was (1) to evaluate the state of the empirical treatment outcome literature on <span class="hlt">bright</span> light therapy for eating disorders and (2) to explore the timing of eating behavior, mood, and sleep-related symptom change so as to understand potential mechanisms of <span class="hlt">bright</span> light therapy action in the context of eating disorder treatment. A comprehensive literature search using PsycInfo and PubMed/MEDLINE was conducted in April 2016 with no date restrictions to identify studies published using <span class="hlt">bright</span> light therapy as a treatment for eating disorders. Keywords included combinations of terms describing disordered eating (eating disorder, anorexia nervosa, bulimia nervosa, binge eating, binge, eating behavior, eating, and night eating) and the use of <span class="hlt">bright</span> light therapy (<span class="hlt">bright</span> light therapy, light therapy, phototherapy). After excluding duplicates, 34 articles were reviewed for inclusion. 14 published studies of <span class="hlt">bright</span> light therapy for eating disorders met inclusion criteria (included participants with an eating disorder/disordered-eating behaviors; presented as a case study, case series, open-label clinical trial, or randomized/nonrandomized controlled trial; written in English; and published and available by the time of manuscript review). Results suggest that <span class="hlt">bright</span> light therapy is potentially effective at improving both disordered-eating behavior and mood acutely, although the timing of symptom response and the duration of treatment effects remain unknown. Future research should</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880043877&hterms=stroke&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dstroke','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880043877&hterms=stroke&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dstroke"><span><span class="hlt">Horizontal</span> electric fields from lightning return strokes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thomson, E. M.; Medelius, P. J.; Rubinstein, M.; Uman, M. A.; Johnson, J.</p> <p>1988-01-01</p> <p>An experiment to measure simultaneously the wideband <span class="hlt">horizontal</span> and vertical electric fields from lightning return strokes is described. Typical wave shapes of the measured <span class="hlt">horizontal</span> and vertical fields are presented, and the <span class="hlt">horizontal</span> fields are characterized. The measured <span class="hlt">horizontal</span> fields are compared with calculated <span class="hlt">horizontal</span> fields obtained by applying the wavetilt formula to the vertical fields. The limitations and sources of error in the measurement technique are discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17990214','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17990214"><span><span class="hlt">Bright</span> light and thermoregulatory responses to exercise.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Atkinson, G; Barr, D; Chester, N; Drust, B; Gregson, W; Reilly, T; Waterhouse, J</p> <p>2008-03-01</p> <p>The thermoregulatory responses to morning exercise after exposure to different schedules of <span class="hlt">bright</span> light were examined. At 07:00 h, six males ran on two occasions in an environmental chamber (temperature = 31.4 +/- 1.0 degrees C, humidity = 66 +/- 6 %) for 40 min at 60 % of maximal oxygen uptake. Participants were exposed to <span class="hlt">bright</span> light (10,000 lux) either between 22:00 - 23:00 h (BT (low)) or 06:00 - 07:00 h (BT (high)). Otherwise, participants remained in dim light (< 50 lux). It was hypothesized that BT (low) attenuates core temperature during morning exercise via the phase-delaying properties of evening <span class="hlt">bright</span> light and by avoiding <span class="hlt">bright</span> light in the morning. Evening <span class="hlt">bright</span> light in BT (low) suppressed (p = 0.037) the increase in melatonin compared to dim light (1.1 +/- 11.4 vs. 15.2 +/- 19.7 pg x ml (-1)) and delayed (p = 0.034) the core temperature minimum by 1.46 +/- 1.24 h. Core temperature was 0.20 +/- 0.17 degrees C lower in BT (low) compared to BT (high) during the hour before exercise (p = 0.036), with evidence (p = 0.075) that this difference was maintained during exercise. Conversely, mean skin temperature was 1.0 +/- 1.7 degrees C higher during the first 10 min of exercise in BT (low) than in BT (high) (p = 0.030). There was evidence that the increase in perceived exertion was attenuated in BT (low) (p = 0.056). A chronobiologically-based light schedule can lower core temperature before and during morning exercise in hot conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9134E..0UF','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9134E..0UF"><span>Generating a high <span class="hlt">brightness</span> multi-kilowatt laser by dense spectral combination of VBG stabilized single emitter laser diodes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fritsche, H.; Koch, Ralf; Krusche, B.; Ferrario, F.; Grohe, Andreas; Pflueger, S.; Gries, W.</p> <p>2014-05-01</p> <p>Generating high power laser radiation with diode lasers is commonly realized by geometrical stacking of diode bars, which results in high output power but poor beam parameter product (BPP). The accessible <span class="hlt">brightness</span> in this approach is limited by the fill factor, both in slow and fast axis. By using a geometry that accesses the BPP of the individual diodes, generating a multi kilowatt diode laser with a BPP comparable to fiber lasers is possible. We will demonstrate such a modular approach for generating multi kilowatt lasers by combining single emitter diode lasers. Single emitter diodes have advantages over bars, mainly a simplified cooling, better reliability and a higher <span class="hlt">brightness</span> per emitter. Additionally, because single emitters can be arranged in many different geometries, they allow building laser modules where the <span class="hlt">brightness</span> of the single emitters is preserved. In order to maintain the high <span class="hlt">brightness</span> of the single emitter we developed a modular laser design which uses single emitters in a staircase arrangement, then coupling two of those bases with <span class="hlt">polarization</span> combination which is our basic module. Those modules generate up to 160 W with a BPP better than 7.5 mm*mrad. For further power scaling wavelength stabilization is crucial. The wavelength is stabilized with only one Volume Bragg Grating (VBG) in front of a base providing the very same feedback to all of the laser diodes. This results in a bandwidth of < 0.5 nm and a wavelength stability of better than 250 MHz over one hour. Dense spectral combination with dichroic mirrors and narrow channel spacing allows us to combine multiple wavelength channels, resulting in a 2 kW laser module with a BPP better than 7.5 mm*mrad, which can easily coupled into a 100 μm fiber and 0.15 NA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA00348&hterms=asphalt&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dasphalt','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA00348&hterms=asphalt&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dasphalt"><span>Iapetus <span class="hlt">Bright</span> and Dark Terrains</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1990-01-01</p> <p>Saturn's outermost large moon, Iapetus, has a <span class="hlt">bright</span>, heavily cratered icy terrain and a dark terrain, as shown in this Voyager 2 image taken on August 22, 1981. Amazingly, the dark material covers precisely the side of Iapetus that leads in the direction of orbital motion around Saturn (except for the poles), whereas the <span class="hlt">bright</span> material occurs on the trailing hemisphere and at the poles. The <span class="hlt">bright</span> terrain is made of dirty ice, and the dark terrain is surfaced by carbonaceous molecules, according to measurements made with Earth-based telescopes. Iapetus' dark hemisphere has been likened to tar or asphalt and is so dark that no details within this terrain were visible to Voyager 2. The <span class="hlt">bright</span> icy hemisphere, likened to dirty snow, shows many large impact craters. The closest approach by Voyager 2 to Iapetus was a relatively distant 600,000 miles, so that our best images, such as this, have a resolution of about 12 miles. The dark material is made of organic substances, probably including poisonous cyano compounds such as frozen hydrogen cyanide polymers. Though we know a little about the dark terrain's chemical nature, we do not understand its origin. Two theories have been developed, but neither is fully satisfactory--(1) the dark material may be organic dust knocked off the small neighboring satellite Phoebe and 'painted' onto the leading side of Iapetus as the dust spirals toward Saturn and Iapetus hurtles through the tenuous dust cloud, or (2) the dark material may be made of icy-cold carbonaceous 'cryovolcanic' lavas that were erupted from Iapetus' interior and then blackened by solar radiation, charged particles, and cosmic rays. A determination of the actual cause, as well as discovery of any other geologic features smaller than 12 miles across, awaits the Cassini Saturn orbiter to arrive in 2004.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhRvB..80e2302Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhRvB..80e2302Z"><span>Observation of <span class="hlt">polarization</span> domain wall solitons in weakly birefringent cavity fiber lasers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, H.; Tang, D. Y.; Zhao, L. M.; Wu, X.</p> <p>2009-08-01</p> <p>We report on the experimental observation of two types of phase-locked vector soliton in weakly birefringent cavity erbium-doped fiber lasers. While a phase-locked dark-dark vector soliton was only observed in fiber lasers of positive dispersion, a phase-locked dark-<span class="hlt">bright</span> vector soliton was obtained in fiber lasers of either positive or negative dispersion. Numerical simulations confirmed the experimental observations and further showed that the observed vector solitons are the two types of phase-locked <span class="hlt">polarization</span> domain wall solitons theoretically predicted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/5722568-chalk-play-tops-gulf-coast-horizontal-scene','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/5722568-chalk-play-tops-gulf-coast-horizontal-scene"><span>Chalk play tops Gulf Coast <span class="hlt">horizontal</span> scene</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Not Available</p> <p>1991-11-18</p> <p>This paper reports on <span class="hlt">horizontal</span> drilling in the Cretaceous Austin chalk of Texas which dominates news of U.S. Gulf Coast <span class="hlt">horizontal</span> action. In spite of a significant decline in <span class="hlt">horizontal</span> drilling in Texas-the Texas Railroad Commission reported a 15 unit decline in the number of permits to drill <span class="hlt">horizontal</span> wells during the third quarter-operators in East and South Texas continue to expand plays and develop new ones. The Cretaceous Bruda may be gaining some respect as a <span class="hlt">horizontal</span> target in Texas. Elsewhere on the Gulf Coast, Mississippi soon will see more action on the <span class="hlt">horizontal</span> drilling front.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29757242','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29757242"><span>Hybrid Transverse <span class="hlt">Polar</span> Navigation for High-Precision and Long-Term INSs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Ruonan; Wu, Qiuping; Han, Fengtian; Zhang, Rong; Hu, Peida; Li, Haixia</p> <p>2018-05-12</p> <p>Transverse navigation has been proposed to help inertial navigation systems (INSs) fill the gap of <span class="hlt">polar</span> navigation ability. However, as the transverse system does not have the ability of navigate globally, a complicated switch between the transverse and the traditional algorithms is necessary when the system moves across the <span class="hlt">polar</span> circles. To maintain the inner continuity and consistency of the core algorithm, a hybrid transverse <span class="hlt">polar</span> navigation is proposed in this research based on a combination of Earth-fixed-frame mechanization and transverse-frame outputs. Furthermore, a thorough analysis of kinematic error characteristics, proper damping technology and corresponding long-term contributions of main error sources is conducted for the high-precision INSs. According to the analytical expressions of the long-term navigation errors in <span class="hlt">polar</span> areas, the 24-h period symmetrical oscillation with a slowly divergent amplitude dominates the transverse <span class="hlt">horizontal</span> position errors, and the first-order drift dominates the transverse azimuth error, which results from the gyro drift coefficients that occur in corresponding directions. Simulations are conducted to validate the theoretical analysis and the deduced analytical expressions. The results show that the proposed hybrid transverse navigation can ensure the same accuracy and oscillation characteristics in <span class="hlt">polar</span> areas as the traditional algorithm in low and mid latitude regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5982164','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5982164"><span>Hybrid Transverse <span class="hlt">Polar</span> Navigation for High-Precision and Long-Term INSs</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wu, Qiuping; Zhang, Rong; Hu, Peida; Li, Haixia</p> <p>2018-01-01</p> <p>Transverse navigation has been proposed to help inertial navigation systems (INSs) fill the gap of <span class="hlt">polar</span> navigation ability. However, as the transverse system does not have the ability of navigate globally, a complicated switch between the transverse and the traditional algorithms is necessary when the system moves across the <span class="hlt">polar</span> circles. To maintain the inner continuity and consistency of the core algorithm, a hybrid transverse <span class="hlt">polar</span> navigation is proposed in this research based on a combination of Earth-fixed-frame mechanization and transverse-frame outputs. Furthermore, a thorough analysis of kinematic error characteristics, proper damping technology and corresponding long-term contributions of main error sources is conducted for the high-precision INSs. According to the analytical expressions of the long-term navigation errors in <span class="hlt">polar</span> areas, the 24-h period symmetrical oscillation with a slowly divergent amplitude dominates the transverse <span class="hlt">horizontal</span> position errors, and the first-order drift dominates the transverse azimuth error, which results from the g0 gyro drift coefficients that occur in corresponding directions. Simulations are conducted to validate the theoretical analysis and the deduced analytical expressions. The results show that the proposed hybrid transverse navigation can ensure the same accuracy and oscillation characteristics in <span class="hlt">polar</span> areas as the traditional algorithm in low and mid latitude regions. PMID:29757242</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SPIE.6751E..0YQ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SPIE.6751E..0YQ"><span><span class="hlt">Polarization</span> transformation as an algorithm for automatic generalization and quality assessment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qian, Haizhong; Meng, Liqiu</p> <p>2007-06-01</p> <p>Since decades it has been a dream of cartographers to computationally mimic the generalization processes in human brains for the derivation of various small-scale target maps or databases from a large-scale source map or database. This paper addresses in a systematic way the <span class="hlt">polarization</span> transformation (PT) - a new algorithm that serves both the purpose of automatic generalization of discrete features and the quality assurance. By means of PT, two dimensional point clusters or line networks in the Cartesian system can be transformed into a <span class="hlt">polar</span> coordinate system, which then can be unfolded as a single spectrum line r = f(α), where r and a stand for the <span class="hlt">polar</span> radius and the <span class="hlt">polar</span> angle respectively. After the transformation, the original features will correspond to nodes on the spectrum line delimited between 0° and 360° along the <span class="hlt">horizontal</span> axis, and between the minimum and maximum <span class="hlt">polar</span> radius along the vertical axis. Since PT is a lossless transformation, it allows a straighforward analysis and comparison of the original and generalized distributions, thus automatic generalization and quality assurance can be down in this way. Examples illustrate that PT algorithm meets with the requirement of generalization of discrete spatial features and is more scientific.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SPIE.7495E..48H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SPIE.7495E..48H"><span>Automatic <span class="hlt">brightness</span> control of laser spot vision inspection system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Han, Yang; Zhang, Zhaoxia; Chen, Xiaodong; Yu, Daoyin</p> <p>2009-10-01</p> <p>The laser spot detection system aims to locate the center of the laser spot after long-distance transmission. The accuracy of positioning laser spot center depends very much on the system's ability to control <span class="hlt">brightness</span>. In this paper, an automatic <span class="hlt">brightness</span> control system with high-performance is designed using the device of FPGA. The <span class="hlt">brightness</span> is controlled by combination of auto aperture (video driver) and adaptive exposure algorithm, and clear images with proper exposure are obtained under different conditions of illumination. Automatic <span class="hlt">brightness</span> control system creates favorable conditions for positioning of the laser spot center later, and experiment results illuminate the measurement accuracy of the system has been effectively guaranteed. The average error of the spot center is within 0.5mm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120002989','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120002989"><span>Visible Color and Photometry of <span class="hlt">Bright</span> Materials on Vesta</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schroder, S. E.; Li, J. Y.; Mittlefehldt, D. W.; Pieters, C. M.; De Sanctis, M. C.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.; Keller, H. U.</p> <p>2012-01-01</p> <p>The Dawn Framing Camera (FC) collected images of the surface of Vesta at a pixel scale of 70 m in the High Altitude Mapping Orbit (HAMO) phase through its clear and seven color filters spanning from 430 nm to 980 nm. The surface of Vesta displays a large diversity in its <span class="hlt">brightness</span> and colors, evidently related to the diverse geology [1] and mineralogy [2]. Here we report a detailed investigation of the visible colors and photometric properties of the apparently <span class="hlt">bright</span> materials on Vesta in order to study their origin. The global distribution and the spectroscopy of <span class="hlt">bright</span> materials are discussed in companion papers [3, 4], and the synthesis results about the origin of Vestan <span class="hlt">bright</span> materials are reported in [5].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA01815&hterms=image+alignment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dimage%2Balignment','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA01815&hterms=image+alignment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dimage%2Balignment"><span>Space Radar Image of Washington D.C.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1994-01-01</p> <p>The city of Washington, D.C., is shown is this space radar image. Images like these are useful tools for urban planners and managers, who use them to map and monitor land use patterns. Downtown Washington is the <span class="hlt">bright</span> area between the Potomac (upper center to lower left) and Anacostia (middle right) rivers. The dark cross shape that is formed by the National Mall, Tidal Basin, the White House and Ellipse is seen in the center of the image. Arlington National Cemetery is the dark blue area on the Virginia (left) side of the Potomac River near the center of the image. The Pentagon is visible in <span class="hlt">bright</span> white and red, south of the cemetery. Due to the alignment of the radar and the streets, the avenues that form the boundary between Washington and Maryland appear as <span class="hlt">bright</span> red lines in the top, right and bottom parts of the image, parallel to the image borders. This image is centered at 38.85 degrees north latitude, 77.05 degrees west longitude. North is toward the upper right. The area shown is approximately 29 km by 26 km (18 miles by 16 miles). Colors are assigned to different frequencies and <span class="hlt">polarizations</span> of the radar as follows: Red is the L-band <span class="hlt">horizontally</span> transmitted, <span class="hlt">horizontally</span> received; green is the L-band <span class="hlt">horizontally</span> transmitted, vertically received; blue is the C-band <span class="hlt">horizontally</span> transmitted, vertically received. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture (SIR-C/X-SAR) imaging radar when it flew aboard the space shuttle Endeavour on April 18, 1994. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA02375&hterms=swiss+cheese&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dswiss%2Bcheese','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA02375&hterms=swiss+cheese&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dswiss%2Bcheese"><span>Complex Burial and Exhumation of South <span class="hlt">Polar</span> Cap Pitted Terrain</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p>This image is illuminated by sunlight from the upper left. The two prominent <span class="hlt">bright</span> stripes at the left/center of the image are covered with <span class="hlt">bright</span> frost and thus create the illusion that they are sunlit from the lower left.<p/>The large pits, troughs, and 'swiss cheese' of the south <span class="hlt">polar</span> residual cap appear to have been formed in the upper 4 or 5 layers of the <span class="hlt">polar</span> material. Each layer is approximately 2 meters (6.6 feet) thick. Some Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images of this terrain show examples in which older pitted and eroded layers have been previously buried and are now being exhumed. The example shown here includes two narrow, diagonal slopes that trend from upper left toward lower right at the left/center portion of the frame. Along the bottoms of these slopes are revealed a layer that underlies them in which there are many more pits and troughs than in the upper layer. It is likely in this case that the lower layer formed its pits and troughs before it was covered by the upper layer. This observation suggests that the troughs, pits, and 'swiss cheese' features of the south <span class="hlt">polar</span> cap are very old and form over long time scales.<p/>The picture is located near 84.6oS, 45.1oW, and covers an area 3 km by 5 km (1.9 x 3.1 mi) at a resolution of about 3.8 meters (12 ft) per pixel. The image was taken during southern spring on August 29, 1999.<p/>Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NIMPA.865...95K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NIMPA.865...95K"><span>Ultrashort high-<span class="hlt">brightness</span> pulses from storage rings</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khan, Shaukat</p> <p>2017-09-01</p> <p>The <span class="hlt">brightness</span> of short-wavelength radiation from accelerator-based sources can be increased by coherent emission in which the radiation intensity scales with the number of contributing electrons squared. This requires a microbunched longitudinal electron distribution, which is the case in free-electron lasers. The <span class="hlt">brightness</span> of light sources based on electron storage rings was steadily improved, but could profit further from coherent emission. The modulation of the electron energy by a continuous-wave laser field may provide steady-state microbunching in the infrared regime. For shorter wavelengths, the energy modulation can be converted into a temporary density modulation by a dispersive chicane. One particular goal is coherent emission from a very short "slice" within an electron bunch in order to produce ultrashort radiation pulses with high <span class="hlt">brightness</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA12605.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA12605.html"><span><span class="hlt">Bright</span> Spokes, Dark Shadow</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2010-04-06</p> <p><span class="hlt">Bright</span> spokes and the shadow of a moon grace Saturn B ring in this NASA Cassini spacecraft image. Spokes are radial markings scientists continue to study, and they can be seen here stretching from the far left to upper right of the image.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060015683','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060015683"><span>Hubble Space Telescope NICMOS <span class="hlt">Polarization</span> Measurements of OMC-1</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Simpson, Janet P.; Colgan, Sean W. J.; Erickson, Edwin F.; Burton, Michael G.; Schultz, A. S. B.</p> <p>2006-01-01</p> <p>We present 2 micrometer <span class="hlt">polarization</span> measurements of positions in the BN region of the Orion Molecular Cloud (OMC-1) made with NICMOS Camera 2 (0.2" resolution) on Hubble Space Telescope. Our goals are to seek the sources of heating for IRc2, 3, 4, and 7, identify possible young stellar objects (YSOs), and characterize the grain alignment in the dust clouds along the lines-of-sight to the stars. Our results are as follows: BN is approximately 29% <span class="hlt">polarized</span> by dichroic absorption and appears to be the illuminating source for most of the nebulosity to its north and up to approximately 5" to its south. Although the stars are probably all <span class="hlt">polarized</span> by dichroic absorption, there are a number of compact, but non-point-source, objects that could be <span class="hlt">polarized</span> by a combination of both dichroic absorption and local scattering of star light. We identify several candidate YSOs, including an approximately edge-on bipolar YSO 8.7" east of BN, and a deeply-embedded IRc7, all of which are obviously self-luminous at mid-infrared wavelengths and may be YSOs. None of these is a reflection nebula illuminated by a star located near radio source I, as was previously suggested. Other IRc sources are clearly reflection nebulae: IRc3 appears to be illuminated by IRc2-B or a combination of the IRc2 sources, and IRc4 and IRc5 appear to be illuminated by an unseen star in the vicinity of radio source I, or by Star n or IRc2-A. Trends in the magnetic field direction are inferred from the <span class="hlt">polarization</span> of the 26 stars that are <span class="hlt">bright</span> enough to be seen as NICMOS point sources. Their <span class="hlt">polarization</span> ranges from N less than or equal to 1% (all stars with this low <span class="hlt">polarization</span> are optically visible) to greater than 40%. The most <span class="hlt">polarized</span> star has a <span class="hlt">polarization</span> position angle different from its neighbors by approximately 40 degrees, but in agreement with the grain alignment inferred from millimeter <span class="hlt">polarization</span> measurements of the cold dust cloud in the southern part of OMC-1. The <span class="hlt">polarization</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150002873','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150002873"><span>Extremely Low Passive Microwave <span class="hlt">Brightness</span> Temperatures Due to Thunderstorms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cecil, Daniel J.</p> <p>2015-01-01</p> <p>Extreme events by their nature fall outside the bounds of routine experience. With imperfect or ambiguous measuring systems, it is appropriate to question whether an unusual measurement represents an extreme event or is the result of instrument errors or other sources of noise. About three weeks after the Tropical Rainfall Measuring Mission (TRMM) satellite began collecting data in Dec 1997, a thunderstorm was observed over northern Argentina with 85 GHz <span class="hlt">brightness</span> temperatures below 50 K and 37 GHz <span class="hlt">brightness</span> temperatures below 70 K (Zipser et al. 2006). These values are well below what had previously been observed from satellite sensors with lower resolution. The 37 GHz <span class="hlt">brightness</span> temperatures are also well below those measured by TRMM for any other storm in the subsequent 16 years. Without corroborating evidence, it would be natural to suspect a problem with the instrument, or perhaps an irregularity with the platform during the first weeks of the satellite mission. Automated quality control flags or other procedures in retrieval algorithms could treat these measurements as errors, because they fall outside the expected bounds. But the TRMM satellite also carries a radar and a lightning sensor, both confirming the presence of an intense thunderstorm. The radar recorded 40+ dBZ reflectivity up to about 19 km altitude. More than 200 lightning flashes per minute were recorded. That same storm's 19 GHz <span class="hlt">brightness</span> temperatures below 150 K would normally be interpreted as the result of a low-emissivity water surface (e.g., a lake, or flood waters) if not for the simultaneous measurements of such intense convection. This paper will examine records from TRMM and related satellite sensors including SSMI, AMSR-E, and the new GMI to find the strongest signatures resulting from thunderstorms, and distinguishing those from sources of noise. The lowest <span class="hlt">brightness</span> temperatures resulting from thunderstorms as seen by TRMM have been in Argentina in November and December. For</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013MNRAS.435.2793R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013MNRAS.435.2793R"><span>A 20 GHz <span class="hlt">bright</span> sample for δ > 72° - II. Multifrequency follow-up</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ricci, R.; Righini, S.; Verma, R.; Prandoni, I.; Carretti, E.; Mack, K.-H.; Massardi, M.; Procopio, P.; Zanichelli, A.; Gregorini, L.; Mantovani, F.; Gawroński, M. P.; Peel, M. W.</p> <p>2013-11-01</p> <p>We present follow-up observations at 5, 8 and 30 GHz of the K-band Northern Wide Survey (KNoWS) 20 GHz <span class="hlt">Bright</span> Sample, performed with the 32-m Medicina radio telescope and the 32-m Toruń radio telescope. The KNoWS sources were selected in the Northern <span class="hlt">Polar</span> Cap (δ > 72°) and have a flux density limit S20 GHz = 115 mJy. We include NRAO-VLA Sky Survey 1.4 GHz measurements to derive the source radio spectra between 1.4 and 30 GHz. Based on optical identifications, 68 per cent of the sources are quasars and 27 per cent are radio galaxies. A redshift measurement is available for 58 per cent of the sources. The radio spectral properties of the different source populations are found to be in agreement with those of other high-frequency-selected samples.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018JGRA..123.4026G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018JGRA..123.4026G"><span>Effect of Small-Scale Gravity Waves on <span class="hlt">Polar</span> Mesospheric Clouds Observed From CIPS/AIM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gao, Haiyang; Li, Licheng; Bu, Lingbing; Zhang, Qilin; Tang, Yuanhe; Wang, Zhen</p> <p>2018-05-01</p> <p>Data from the Cloud Imaging and Particle Size experiment on the Aeronomy of Ice in the Mesosphere (AIM) satellite are employed to study the impact of small-scale gravity wave (GW) on albedo, ice water content (IWC), and particle radius (PR) of <span class="hlt">polar</span> mesospheric clouds. Overall, 23,987 eligible GW events, with a <span class="hlt">horizontal</span> wavelength of 20-150 km are eventually extracted from Cloud Imaging and Particle Size level 2 orbit albedo maps during 2007-2011. The overall statistical results show that when small-scale GWs travel <span class="hlt">horizontally</span> in <span class="hlt">polar</span> mesospheric clouds, they can amplify the albedo and IWC by a rate of 10.0-22.6%, while reducing the PR by as much as -7.01%. Owing to the strong temporal and spatial dependences, the albedo and IWC variations are larger on an average during the core of the season, while they decrease during the initial and final periods of the season. The obvious zonal asymmetries are also found. The albedo variations show a positive linear relation with the GW amplitudes in albedo, as opposed to a negative linear relation with GW <span class="hlt">horizontal</span> wavelengths. In most of the GW events, the periodic variation in the trend of albedo exhibits an anticorrelation with that of PR. Combining previous research studies with our results, we deduce that the rapid change in particle concentration and the upward movement of water vapor by GWs may be very important aspects for explaining the influence mechanism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1376610','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1376610"><span>Role of flexoelectric coupling in <span class="hlt">polarization</span> rotations at the a-c domain walls in ferroelectric perovskites</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Cao, Ye; Chen, Long-Qing; Kalinin, Sergei V.</p> <p></p> <p>Ferroelectric and ferroelastic domain walls play important roles in ferroelectric properties. However, their couplings with flexoelectricity have been less understood. Here, we applied phase-field simulation to investigate the flexoelectric coupling with ferroelectric a/c twin structures in lead ziconate titanate thin films. Local stress gradients were found to exist near twin walls that created both lateral and vertical electric fields through the flexoelectric effect, resulting in <span class="hlt">polarization</span> inclinations from either <span class="hlt">horizontal</span> or normal orientation, <span class="hlt">polarization</span> rotation angles deviated from 90°, and consequently highly asymmetric a/c twin walls. Furthermore, by tuning the flexoelectric strengths in a reasonable range from first-principles calculations, wemore » found that the transverse flexoelectric coefficient has a larger influence on the <span class="hlt">polarization</span> rotation than longitudinal and shear coefficients. And as <span class="hlt">polar</span> rotations that commonly occur at compositional morphotropic phase boundaries contribute to the piezoelectric enhancement, this work calls for further exploration of alternative strain-engineered <span class="hlt">polar</span> rotations via flexoelectricity in ferroelectric thin films.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1376610-role-flexoelectric-coupling-polarization-rotations-domain-walls-ferroelectric-perovskites','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1376610-role-flexoelectric-coupling-polarization-rotations-domain-walls-ferroelectric-perovskites"><span>Role of flexoelectric coupling in <span class="hlt">polarization</span> rotations at the a-c domain walls in ferroelectric perovskites</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Cao, Ye; Chen, Long-Qing; Kalinin, Sergei V.</p> <p>2017-05-16</p> <p>Ferroelectric and ferroelastic domain walls play important roles in ferroelectric properties. However, their couplings with flexoelectricity have been less understood. Here, we applied phase-field simulation to investigate the flexoelectric coupling with ferroelectric a/c twin structures in lead ziconate titanate thin films. Local stress gradients were found to exist near twin walls that created both lateral and vertical electric fields through the flexoelectric effect, resulting in <span class="hlt">polarization</span> inclinations from either <span class="hlt">horizontal</span> or normal orientation, <span class="hlt">polarization</span> rotation angles deviated from 90°, and consequently highly asymmetric a/c twin walls. Furthermore, by tuning the flexoelectric strengths in a reasonable range from first-principles calculations, wemore » found that the transverse flexoelectric coefficient has a larger influence on the <span class="hlt">polarization</span> rotation than longitudinal and shear coefficients. And as <span class="hlt">polar</span> rotations that commonly occur at compositional morphotropic phase boundaries contribute to the piezoelectric enhancement, this work calls for further exploration of alternative strain-engineered <span class="hlt">polar</span> rotations via flexoelectricity in ferroelectric thin films.« less</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19880000194&hterms=boring&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dboring','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19880000194&hterms=boring&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dboring"><span>Portable <span class="hlt">Horizontal</span>-Drilling And Positioning Device</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smigocki, Edmund; Johnson, Clarence</p> <p>1988-01-01</p> <p>Portable <span class="hlt">horizontal</span>-drilling and positioning device, constructed mainly of off-the-shelf components, accurately drills <span class="hlt">horizontal</span> small holes in irregularly shaped objects. Holes precisely placed and drilled in objects that cannot be moved to shop area. New device provides three axes of movement while maintaining <span class="hlt">horizontal</span> drilling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20052243','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20052243"><span>Three-color Sagnac source of <span class="hlt">polarization</span>-entangled photon pairs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hentschel, Michael; Hübel, Hannes; Poppe, Andreas; Zeilinger, Anton</p> <p>2009-12-07</p> <p>We demonstrate a compact and stable source of <span class="hlt">polarization</span>-entangled pairs of photons, one at 810 nm wavelength for high detection efficiency and the other at 1550 nm for long-distance fiber communication networks. Due to a novel Sagnac-based design of the interferometer no active stabilization is needed. Using only one 30 mm ppKTP bulk crystal the source produces photons with a spectral <span class="hlt">brightness</span> of 1.13 x 10(6) pairs/s/mW/THz with an entanglement fidelity of 98.2%. Both photons are single-mode fiber coupled and ready to be used in quantum key distribution (QKD) or transmission of photonic quantum states over large distances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27416586','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27416586"><span>Autofocusing and <span class="hlt">Polar</span> Body Detection in Automated Cell Manipulation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Zenan; Feng, Chen; Ang, Wei Tech; Tan, Steven Yih Min; Latt, Win Tun</p> <p>2017-05-01</p> <p>Autofocusing and feature detection are two essential processes for performing automated biological cell manipulation tasks. In this paper, we have introduced a technique capable of focusing on a holding pipette and a mammalian cell under a <span class="hlt">bright</span>-field microscope automatically, and a technique that can detect and track the presence and orientation of the <span class="hlt">polar</span> body of an oocyte that is rotated at the tip of a micropipette. Both algorithms were evaluated by using mouse oocytes. Experimental results show that both algorithms achieve very high success rates: 100% and 96%. As robust and accurate image processing methods, they can be widely applied to perform various automated biological cell manipulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120013214','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120013214"><span>Synthesizing SMOS Zero-Baselines with Aquarius <span class="hlt">Brightness</span> Temperature Simulator</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Colliander, A.; Dinnat, E.; Le Vine, D.; Kainulainen, J.</p> <p>2012-01-01</p> <p>SMOS [1] and Aquarius [2] are ESA and NASA missions, respectively, to make L-band measurements from the Low Earth Orbit. SMOS makes passive measurements whereas Aquarius measures both passive and active. SMOS was launched in November 2009 and Aquarius in June 2011.The scientific objectives of the missions are overlapping: both missions aim at mapping the global Sea Surface Salinity (SSS). Additionally, SMOS mission produces soil moisture product (however, Aquarius data will eventually be used for retrieving soil moisture too). The consistency of the <span class="hlt">brightness</span> temperature observations made by the two instruments is essential for long-term studies of SSS and soil moisture. For resolving the consistency, the calibration of the instruments is the key. The basis of the SMOS <span class="hlt">brightness</span> temperature level is the measurements performed with the so-called zero-baselines [3]; SMOS employs an interferometric measurement technique which forms a <span class="hlt">brightness</span> temperature image from several baselines constructed by combination of multiple receivers in an array; zero-length baseline defines the overall <span class="hlt">brightness</span> temperature level. The basis of the Aquarius <span class="hlt">brightness</span> temperature level is resolved from the <span class="hlt">brightness</span> temperature simulator combined with ancillary data such as antenna patterns and environmental models [4]. Consistency between the SMOS zero-baseline measurements and the simulator output would provide a robust basis for establishing the overall comparability of the missions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26863420','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26863420"><span>Music for a Brighter World: <span class="hlt">Brightness</span> Judgment Bias by Musical Emotion.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bhattacharya, Joydeep; Lindsen, Job P</p> <p>2016-01-01</p> <p>A prevalent conceptual metaphor is the association of the concepts of good and evil with <span class="hlt">brightness</span> and darkness, respectively. Music cognition, like metaphor, is possibly embodied, yet no study has addressed the question whether musical emotion can modulate <span class="hlt">brightness</span> judgment in a metaphor consistent fashion. In three separate experiments, participants judged the <span class="hlt">brightness</span> of a grey square that was presented after a short excerpt of emotional music. The results of Experiment 1 showed that short musical excerpts are effective emotional primes that cross-modally influence <span class="hlt">brightness</span> judgment of visual stimuli. Grey squares were consistently judged as brighter after listening to music with a positive valence, as compared to music with a negative valence. The results of Experiment 2 revealed that the bias in <span class="hlt">brightness</span> judgment does not require an active evaluation of the emotional content of the music. By applying a different experimental procedure in Experiment 3, we showed that this <span class="hlt">brightness</span> judgment bias is indeed a robust effect. Altogether, our findings demonstrate a powerful role of musical emotion in biasing <span class="hlt">brightness</span> judgment and that this bias is aligned with the metaphor viewpoint.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ASPC..486...65P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ASPC..486...65P"><span>IC 5181: An S0 Galaxy with Ionized Gas on <span class="hlt">Polar</span> Orbits</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pizzella, A.; Morelli, L.; Corsini, E. M.; Dalla Bontá, E.; Cesetti, M.</p> <p>2014-05-01</p> <p>The nearby S0 galaxy IC 5181 is studied to address the origin of the ionized gas component that orbits the galaxy on <span class="hlt">polar</span> orbit. We perform detailed photometric and spectroscopic observations measuring the surface <span class="hlt">brightness</span> distribution of the stars (I band), ionized gas of IC 5181 (Hα narrow band), the ionized-gas and stellar kinematics along both the major and minor axis, and the corresponding line strengths of the Lick indices. We conclude that the galaxy hosts a geometrically and kinematically decoupled component of ionized gas. It is elongated along the galaxy minor axis and in orthogonal rotation with respect to the galaxy disk. The result is suggesting that the gas component is not related to the stars having an external origin. The gas was accreted by IC 5181 on <span class="hlt">polar</span> orbits from the surrounding environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.791a2002H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.791a2002H"><span>Present and future experiments using <span class="hlt">bright</span> low-energy positron beams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hugenschmidt, Christoph</p> <p>2017-01-01</p> <p><span class="hlt">Bright</span> slow positron beams enable not only experiments with drastically reduced measurement time and improved signal-to-noise ratio but also the realization of novel experimental techniques. In solid state physics and materials science positron beams are usually applied for the depth dependent analysis of vacancy-like defects and their chemical surrounding using positron lifetime and (coincident) Doppler broadening spectroscopy. For surface studies, annihilation induced Auger-electron spectroscopy allows the analysis of the elemental composition in the topmost atomic layer, and the atomic positions at the surface can be determined by positron diffraction with outstanding accuracy. In fundamental research low-energy positron beams are used for the production of e.g. cold positronium or positronium negative ions. All the aforementioned experiments benefit from the high intensity of present positron beam facilities. In this paper, we scrutinize the technical constraints limiting the achievable positron intensity and the available kinetic energy at the sample position. Current efforts and future developments towards the generation of high intensity spin-<span class="hlt">polarized</span> slow positron beams paving the way for new positron experiments are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3283774','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3283774"><span>Excitation Spectra and <span class="hlt">Brightness</span> Optimization of Two-Photon Excited Probes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mütze, Jörg; Iyer, Vijay; Macklin, John J.; Colonell, Jennifer; Karsh, Bill; Petrášek, Zdeněk; Schwille, Petra; Looger, Loren L.; Lavis, Luke D.; Harris, Timothy D.</p> <p>2012-01-01</p> <p>Two-photon probe excitation data are commonly presented as absorption cross section or molecular <span class="hlt">brightness</span> (the detected fluorescence rate per molecule). We report two-photon molecular <span class="hlt">brightness</span> spectra for a diverse set of organic and genetically encoded probes with an automated spectroscopic system based on fluorescence correlation spectroscopy. The two-photon action cross section can be extracted from molecular <span class="hlt">brightness</span> measurements at low excitation intensities, while peak molecular <span class="hlt">brightness</span> (the maximum molecular <span class="hlt">brightness</span> with increasing excitation intensity) is measured at higher intensities at which probe photophysical effects become significant. The spectral shape of these two parameters was similar across all dye families tested. Peak molecular <span class="hlt">brightness</span> spectra, which can be obtained rapidly and with reduced experimental complexity, can thus serve as a first-order approximation to cross-section spectra in determining optimal wavelengths for two-photon excitation, while providing additional information pertaining to probe photostability. The data shown should assist in probe choice and experimental design for multiphoton microscopy studies. Further, we show that, by the addition of a passive pulse splitter, nonlinear bleaching can be reduced—resulting in an enhancement of the fluorescence signal in fluorescence correlation spectroscopy by a factor of two. This increase in fluorescence signal, together with the observed resemblance of action cross section and peak <span class="hlt">brightness</span> spectra, suggests higher-order photobleaching pathways for two-photon excitation. PMID:22385865</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PASP..129c5003P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PASP..129c5003P"><span>Night Sky <span class="hlt">Brightness</span> at San Pedro Martir Observatory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Plauchu-Frayn, I.; Richer, M. G.; Colorado, E.; Herrera, J.; Córdova, A.; Ceseña, U.; Ávila, F.</p> <p>2017-03-01</p> <p>We present optical UBVRI zenith night sky <span class="hlt">brightness</span> measurements collected on 18 nights during 2013 to 2016 and SQM measurements obtained daily over 20 months during 2014 to 2016 at the Observatorio Astronómico Nacional on the Sierra San Pedro Mártir (OAN-SPM) in México. The UBVRI data is based upon CCD images obtained with the 0.84 m and 2.12 m telescopes, while the SQM data is obtained with a high-sensitivity, low-cost photometer. The typical moonless night sky <span class="hlt">brightness</span> at zenith averaged over the whole period is U = 22.68, B = 23.10, V = 21.84, R = 21.04, I = 19.36, and SQM = 21.88 {mag} {{arcsec}}-2, once corrected for zodiacal light. We find no seasonal variation of the night sky <span class="hlt">brightness</span> measured with the SQM. The typical night sky <span class="hlt">brightness</span> values found at OAN-SPM are similar to those reported for other astronomical dark sites at a similar phase of the solar cycle. We find a trend of decreasing night sky <span class="hlt">brightness</span> with decreasing solar activity during period of the observations. This trend implies that the sky has become darker by Δ U = 0.7, Δ B = 0.5, Δ V = 0.3, Δ R=0.5 mag arcsec-2 since early 2014 due to the present solar cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010002506&hterms=Viking&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DViking','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010002506&hterms=Viking&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DViking"><span>Martian North <span class="hlt">Polar</span> Water-Ice Clouds During the Viking Era</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tamppari, L. K.; Bass, D. S.</p> <p>2000-01-01</p> <p>The Viking Orbiters determined that the surface of Mars' northern residual cap consists of water ice. Observed atmospheric water vapor abundances in the equatorial regions have been related to seasonal exchange between reservoirs such as the <span class="hlt">polar</span> caps, the regolith and between different phases in the atmosphere. Kahn modeled the physical characteristics of ice hazes seen in Viking Orbiter imaging limb data, hypothesizing that ice hazes provide a method for scavenging water vapor from the atmosphere and accumulating it into ice particles. Given that Jakosky found that these particles had sizes such that fallout times were of order one Martian sol, these water-ice hazes provided a method for returning more water to the regolith than that provided by adsorption alone. These hazes could also explain the rapid hemispheric decrease in atmospheric water in late northern summer as well as the increase during the following early spring. A similar comparison of water vapor abundance versus <span class="hlt">polar</span> cap <span class="hlt">brightness</span> has been done for the north <span class="hlt">polar</span> region. They have shown that water vapor decreases steadily between L(sub s) = 100-150 deg while <span class="hlt">polar</span> cap albedo increases during the same time frame. As a result, they suggested that late summer water-ice deposition onto the ice cap may be the cause of the cap brightening. This deposition could be due to adsorption directly onto the cap surface or to snowfall. Thus, an examination of north <span class="hlt">polar</span> waterice clouds could lend insight into the fate of the water vapor during this time period. Additional information is contained in the original extended abstract.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20939322','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20939322"><span>[Detection of oil spills on water by differential <span class="hlt">polarization</span> FTIR spectrometry].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yuan, Yue-ming; Xiong, Wei; Fang, Yong-hua; Lan, Tian-ge; Li, Da-cheng</p> <p>2010-08-01</p> <p>Detection of oil spills on water, by traditional thermal remote sensing, is based on the radiance contrast between the large area of clean water and the polluted area of water. And the categories of oil spills can not be identified by analysing the thermal infrared image. In order to find out the extent of pollution and identify the oil contaminants, an approach to the passive detection of oil spills on water by differential <span class="hlt">polarization</span> FTIR spectrometry is proposed. This approach can detect the contaminants by obtaining and analysing the subtracted spectrum of <span class="hlt">horizontal</span> and vertical <span class="hlt">polarization</span> intensity spectrum. In the present article, the radiance model of differential <span class="hlt">polarization</span> FTIR spectrometry is analysed, and an experiment about detection of No. O diesel and SF96 film on water by this method is presented. The results of this experiment indicate that this method can detect the oil contaminants on water without radiance contrast with clean water, and it also can identify oil spills by analysing the spectral characteristic of differential <span class="hlt">polarization</span> FTIR spectrum. So it well makes up for the shortage of traditional thermal remote sensing on detecting oil spills on water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3311899','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3311899"><span>Simultaneous <span class="hlt">brightness</span> contrast of foraging Papilio butterflies</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kinoshita, Michiyo; Takahashi, Yuki; Arikawa, Kentaro</p> <p>2012-01-01</p> <p>This study focuses on the sense of <span class="hlt">brightness</span> in the foraging Japanese yellow swallowtail butterfly, Papilio xuthus. We presented two red discs of different intensity on a grey background to butterflies, and trained them to select one of the discs. They were successfully trained to select either a high intensity or a low intensity disc. The trained butterflies were tested on their ability to perceive <span class="hlt">brightness</span> in two different protocols: (i) two orange discs of different intensity presented on the same intensity grey background and (ii) two orange discs of the same intensity separately presented on a grey background that was either higher or lower in intensity than the training background. The butterflies trained to high intensity red selected the orange disc of high intensity in protocol 1, and the disc on the background of low intensity grey in protocol 2. We obtained similar results in another set of experiments with purple discs instead of orange discs. The choices of the butterflies trained to low intensity red were opposite to those just described. Taken together, we conclude that Papilio has the ability to learn <span class="hlt">brightness</span> and darkness of targets independent of colour, and that they have the so-called simultaneous <span class="hlt">brightness</span> contrast. PMID:22179808</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130000446','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130000446"><span>Near-term <span class="hlt">Horizontal</span> Launch for Flexible Operations: Results of the DARPA/NASA <span class="hlt">Horizontal</span> Launch Study</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bartolotta, Paul A.; Wilhite, Alan W.; Schaffer, Mark G.; Huebner, Lawrence D.; Voland, Randall T.; Voracek, David F.</p> <p>2012-01-01</p> <p><span class="hlt">Horizontal</span> launch has been investigated for 60 years by over 130 different studies. During this time only one concept, Pegasus, has ever been in operation. The attractiveness of <span class="hlt">horizontal</span> launch is the capability to provide a "mobile launch pad" that can use existing aircraft runways, cruise above weather, loiter for mission instructions, and provide precise placement for orbital intercept, rendezvous, or reconnaissance. A jointly sponsored study by DARPA and NASA, completed in 2011, explored the trade space of <span class="hlt">horizontal</span> launch system concepts which included an exhaustive literature review of the past 70 years. The <span class="hlt">Horizontal</span> Launch Study identified potential near- and mid-term concepts capable of delivering 15,000 lb payloads to a 28.5 due East inclination, 100 nautical-mile low-Earth orbit. Results are presented for a range of near-term system concepts selected for their availability and relatively low design, development, test, and evaluation (DDT&E) costs. This study identified a viable low-cost development path forward to make a robust and resilient <span class="hlt">horizontal</span> launch capability a reality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3985985','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3985985"><span>Motion-artifact-robust, <span class="hlt">polarization</span>-resolved second-harmonic-generation microscopy based on rapid <span class="hlt">polarization</span> switching with electro-optic Pockells cell and its application to in vivo visualization of collagen fiber orientation in human facial skin</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tanaka, Yuji; Hase, Eiji; Fukushima, Shuichiro; Ogura, Yuki; Yamashita, Toyonobu; Hirao, Tetsuji; Araki, Tsutomu; Yasui, Takeshi</p> <p>2014-01-01</p> <p><span class="hlt">Polarization</span>-resolved second-harmonic-generation (PR-SHG) microscopy is a powerful tool for investigating collagen fiber orientation quantitatively with low invasiveness. However, the waiting time for the mechanical <span class="hlt">polarization</span> rotation makes it too sensitive to motion artifacts and hence has hampered its use in various applications in vivo. In the work described in this article, we constructed a motion-artifact-robust, PR-SHG microscope based on rapid <span class="hlt">polarization</span> switching at every pixel with an electro-optic Pockells cell (PC) in synchronization with step-wise raster scanning of the focus spot and alternate data acquisition of a vertical-<span class="hlt">polarization</span>-resolved SHG signal and a <span class="hlt">horizontal-polarization</span>-resolved one. The constructed PC-based PR-SHG microscope enabled us to visualize orientation mapping of dermal collagen fiber in human facial skin in vivo without the influence of motion artifacts. Furthermore, it implied the location and/or age dependence of the collagen fiber orientation in human facial skin. The robustness to motion artifacts in the collagen orientation measurement will expand the application scope of SHG microscopy in dermatology and collagen-related fields. PMID:24761292</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890031691&hterms=bright+hour&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbright%2Bhour','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890031691&hterms=bright+hour&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbright%2Bhour"><span>A study of coronal <span class="hlt">bright</span> points at 20 cm wavelength</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nitta, N.; Kundu, M. R.</p> <p>1988-01-01</p> <p>The paper presents the results of a study of coronal <span class="hlt">bright</span> points observed at 20 cm with the VLA on a day when the sun was exceptionally quiet. Microwave maps of <span class="hlt">bright</span> points were obtained using data for the entire observing period of 5 hours, as well as for shorter periods of a few minutes. Most <span class="hlt">bright</span> points, especially those appearing in the full-period maps, appear to be associated with small bipolar structures on the photospheric magnetogram. Overlays of <span class="hlt">bright</span> point (BP) maps on the Ca(+) K picture, show that the brightest part of BP tends to lie on the boundary of a supergranulation network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19990116038&hterms=EIT&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DEIT','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19990116038&hterms=EIT&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DEIT"><span>Micro Coronal <span class="hlt">Bright</span> Points Observed in the Quiet Magnetic Network by SOHO/EIT</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Falconer, D. A.; Moore, R. L.; Porter, J. G.</p> <p>1997-01-01</p> <p>When one looks at SOHO/EIT Fe XII images of quiet regions, one can see the conventional coronal <span class="hlt">bright</span> points (> 10 arcsec in diameter), but one will also notice many smaller faint enhancements in <span class="hlt">brightness</span> (Figure 1). Do these micro coronal <span class="hlt">bright</span> points belong to the same family as the conventional <span class="hlt">bright</span> points? To investigate this question we compared SOHO/EIT Fe XII images with Kitt Peak magnetograms to determine whether the micro <span class="hlt">bright</span> points are in the magnetic network and mark magnetic bipoles within the network. To identify the coronal <span class="hlt">bright</span> points, we applied a picture frame filter to the Fe XII images; this brings out the Fe XII network and <span class="hlt">bright</span> points (Figure 2) and allows us to study the <span class="hlt">bright</span> points down to the resolution limit of the SOHO/EIT instrument. This picture frame filter is a square smoothing function (hlargelyalf a network cell wide) with a central square (quarter of a network cell wide) removed so that a <span class="hlt">bright</span> point's intensity does not effect its own background. This smoothing function is applied to the full disk image. Then we divide the original image by the smoothed image to obtain our filtered image. A <span class="hlt">bright</span> point is defined as any contiguous set of pixels (including diagonally) which have enhancements of 30% or more above the background; a micro <span class="hlt">bright</span> point is any <span class="hlt">bright</span> point 16 pixels or smaller in size. We then analyzed the <span class="hlt">bright</span> points that were fully within quiet regions (0.6 x 0.6 solar radius) centered on disk center on six different days.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014A%26A...568A..13R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014A%26A...568A..13R"><span>Comparison of solar photospheric <span class="hlt">bright</span> points between Sunrise observations and MHD simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Riethmüller, T. L.; Solanki, S. K.; Berdyugina, S. V.; Schüssler, M.; Martínez Pillet, V.; Feller, A.; Gandorfer, A.; Hirzberger, J.</p> <p>2014-08-01</p> <p><span class="hlt">Bright</span> points (BPs) in the solar photosphere are thought to be the radiative signatures (small-scale <span class="hlt">brightness</span> enhancements) of magnetic elements described by slender flux tubes or sheets located in the darker intergranular lanes in the solar photosphere. They contribute to the ultraviolet (UV) flux variations over the solar cycle and hence may play a role in influencing the Earth's climate. Here we aim to obtain a better insight into their properties by combining high-resolution UV and spectro-polarimetric observations of BPs by the Sunrise Observatory with 3D compressible radiation magnetohydrodynamical (MHD) simulations. To this end, full spectral line syntheses are performed with the MHD data and a careful degradation is applied to take into account all relevant instrumental effects of the observations. In a first step it is demonstrated that the selected MHD simulations reproduce the measured distributions of intensity at multiple wavelengths, line-of-sight velocity, spectral line width, and <span class="hlt">polarization</span> degree rather well. The simulated line width also displays the correct mean, but a scatter that is too small. In the second step, the properties of observed BPs are compared with synthetic ones. Again, these are found to match relatively well, except that the observations display a tail of large BPs with strong <span class="hlt">polarization</span> signals (most likely network elements) not found in the simulations, possibly due to the small size of the simulation box. The higher spatial resolution of the simulations has a significant effect, leading to smaller and more numerous BPs. The observation that most BPs are weakly <span class="hlt">polarized</span> is explained mainly by the spatial degradation, the stray light contamination, and the temperature sensitivity of the Fe i line at 5250.2 Å. Finally, given that the MHD simulations are highly consistent with the observations, we used the simulations to explore the properties of BPs further. The Stokes V asymmetries increase with the distance to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5228668','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5228668"><span>Life-threatening motor vehicle crashes in <span class="hlt">bright</span> sunlight</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Redelmeier, Donald A.; Raza, Sheharyar</p> <p>2017-01-01</p> <p>Abstract <span class="hlt">Bright</span> sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in <span class="hlt">bright</span> sunlight. This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with <span class="hlt">bright</span> sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later. The majority of patients (n = 6962) were injured during daylight hours and <span class="hlt">bright</span> sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during <span class="hlt">bright</span> sunlight than normal weather (95% confidence interval: 9–24, P < 0.001). The increased risk was accentuated in the early afternoon, disappeared at night, extended to patients with different characteristics, involved crashes with diverse features, not apparent with cloudy weather, and contributed to about 5000 additional patient-days in hospital. The increased risk extended to patients with high crash severity as indicated by ambulance involvement, surgical procedures, length of hospital stay, intensive care unit admission, and patient mortality. The increased risk was not easily attributed to differences in alcohol consumption, driving distances, or anomalies of adverse weather. <span class="hlt">Bright</span> sunlight is associated with an increased risk of a life-threatening motor vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash. Level of evidence: Epidemiologic Study, level III. PMID:28072708</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28072708','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28072708"><span>Life-threatening motor vehicle crashes in <span class="hlt">bright</span> sunlight.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Redelmeier, Donald A; Raza, Sheharyar</p> <p>2017-01-01</p> <p><span class="hlt">Bright</span> sunlight may create visual illusions that lead to driver error, including fallible distance judgment from aerial perspective. We tested whether the risk of a life-threatening motor vehicle crash was increased when driving in <span class="hlt">bright</span> sunlight.This longitudinal, case-only, paired-comparison analysis evaluated patients hospitalized because of a motor vehicle crash between January 1, 1995 and December 31, 2014. The relative risk of a crash associated with <span class="hlt">bright</span> sunlight was estimated by evaluating the prevailing weather at the time and place of the crash compared with the weather at the same hour and location on control days a week earlier and a week later.The majority of patients (n = 6962) were injured during daylight hours and <span class="hlt">bright</span> sunlight was the most common weather condition at the time and place of the crash. The risk of a life-threatening crash was 16% higher during <span class="hlt">bright</span> sunlight than normal weather (95% confidence interval: 9-24, P < 0.001). The increased risk was accentuated in the early afternoon, disappeared at night, extended to patients with different characteristics, involved crashes with diverse features, not apparent with cloudy weather, and contributed to about 5000 additional patient-days in hospital. The increased risk extended to patients with high crash severity as indicated by ambulance involvement, surgical procedures, length of hospital stay, intensive care unit admission, and patient mortality. The increased risk was not easily attributed to differences in alcohol consumption, driving distances, or anomalies of adverse weather.<span class="hlt">Bright</span> sunlight is associated with an increased risk of a life-threatening motor vehicle crash. An awareness of this risk might inform driver education, trauma staffing, and safety warnings to prevent a life-threatening motor vehicle crash. Epidemiologic Study, level III.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4749205','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4749205"><span>Music for a Brighter World: <span class="hlt">Brightness</span> Judgment Bias by Musical Emotion</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2016-01-01</p> <p>A prevalent conceptual metaphor is the association of the concepts of good and evil with <span class="hlt">brightness</span> and darkness, respectively. Music cognition, like metaphor, is possibly embodied, yet no study has addressed the question whether musical emotion can modulate <span class="hlt">brightness</span> judgment in a metaphor consistent fashion. In three separate experiments, participants judged the <span class="hlt">brightness</span> of a grey square that was presented after a short excerpt of emotional music. The results of Experiment 1 showed that short musical excerpts are effective emotional primes that cross-modally influence <span class="hlt">brightness</span> judgment of visual stimuli. Grey squares were consistently judged as brighter after listening to music with a positive valence, as compared to music with a negative valence. The results of Experiment 2 revealed that the bias in <span class="hlt">brightness</span> judgment does not require an active evaluation of the emotional content of the music. By applying a different experimental procedure in Experiment 3, we showed that this <span class="hlt">brightness</span> judgment bias is indeed a robust effect. Altogether, our findings demonstrate a powerful role of musical emotion in biasing <span class="hlt">brightness</span> judgment and that this bias is aligned with the metaphor viewpoint. PMID:26863420</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018eMetN...3...51K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018eMetN...3...51K"><span>Two <span class="hlt">bright</span> fireballs over Great Britain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koukal, Jakub; Káčerek, Richard</p> <p>2018-02-01</p> <p>On November 24, 2017 shortly before midnight and on November 25, 2017 shortly before sunrise, two very <span class="hlt">bright</span> fireballs lit up the sky over the United Kingdom. The UKMON (United Kingdom Meteor Observation Network) cameras and onboard cameras in the automobiles recorded their flight. The fireballs paths in the Earth's atmosphere were calculated, as well as the orbits of bodies in the Solar System. The flight of both bodies, the absolute magnitude of which approached the <span class="hlt">brightness</span> of the full Moon, was also observed by numerous random observers from the public in Great Britain, Ireland and France.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.771a2033H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.771a2033H"><span>Sky <span class="hlt">brightness</span> and twilight measurements at Jogyakarta city, Indonesia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Herdiwijaya, Dhani</p> <p>2016-11-01</p> <p>The sky <span class="hlt">brightness</span> measurements were performed using a portable photometer. A pocket-sized and low-cost photometer has 20 degree area measurement, and spectral ranges between 320-720 nm with output directly in magnitudes per arc second square (mass) unit. The sky <span class="hlt">brightness</span> with 3 seconds temporal resolutions was recorded at Jogyakarta city (110° 25’ E; 70° 52’ S; elevation 100 m) within 136 days in years from 2014 to 2016. The darkest night could reach 22.61 mpass only in several seconds, with mean value 18.8±0.7 mpass and temperature variation 23.1±1.2 C. The difference of mean sky <span class="hlt">brightness</span> between before and after midnight was about -0.76 mpass or 2.0 times brighter. Moreover, the sky <span class="hlt">brightness</span> and temperature fluctuations were more stable in after midnight than in before midnight. It is suggested that city light pollution affects those variations, and subsequently duration of twilight. By comparing twilight <span class="hlt">brightness</span> for several places, we also suggest a 17° solar dip or about 66 minutes before sunrise for new time of Fajr prayer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870044139&hterms=senior&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsenior','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870044139&hterms=senior&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsenior"><span>Relating <span class="hlt">polarization</span> phase difference of SAR signals to scene properties</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ulaby, Fawwaz T.; Dobson, Myron C.; Mcdonald, Kyle C.; Senior, Thomas B. A.; Held, Daniel</p> <p>1987-01-01</p> <p>This paper examines the statistical behavior of the phase difference Delta-phi between the HH-<span class="hlt">polarized</span> and VV-<span class="hlt">polarized</span> backscattered signals recorded by an L-band SAR over an agricultural test site in Illinois. <span class="hlt">Polarization</span>-phase difference distributions were generated for about 200 agricultural fields for which ground information had been acquired in conjunction with the SAR mission. For the overwhelming majority of cases, the Delta-phi distribution is symmetric and has a single major lobe centered at the mean value of the distribution Delta-phi. Whereas the mean Delta-phi was found to be close to zero degrees for bare soil, cut vegetation, alfalfa, soybeans, and clover, a different pattern was observed for the corn fields; the mean Delta-phi increased with increasing incidence angle Theta = 35 deg. The explanation proposed for this variation is that the corn canopy, most of whose mass is contained in its vertical stalks, acts like a uniaxial crystal characterized by different velocities of propagation for waves with <span class="hlt">horizontal</span> and vertical <span class="hlt">polarization</span>. Thus, it is hypothesized that the observed backscatter is contributed by a combination of propagation delay, forward scatter by the soil surface, and specular bistatic reflection by the stalks. Model calculations based on this assumption were found to be in general agreement with the phase observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AAS...23115026M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AAS...23115026M"><span>Simulations of <span class="hlt">Polarization</span> Leakage and Ionospheric Attenuation in Visibility Measurements for the HERA and PAPER Experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martinot, Zachary; Kohn, Saul; Aguirre, James; Washington, Immanuel; HERA Collaboration, PAPER Collaboration</p> <p>2018-01-01</p> <p>The HERA and PAPER experiments that aim to detect the power spectrum of the 21cm <span class="hlt">brightness</span> temperature during the Epoch of Reionization (EoR) are planned with the expectation that foregrounds will be separated from the cosmological signal by a clearly demarcated boundary in Fourier space. <span class="hlt">Polarized</span> foregrounds with complex frequency structure present a potential systematic as their mixing into unpolarized signal by the <span class="hlt">polarized</span> response of an instrument's beam may be confused for the unpolarized EoR signal. There are two factors we believe will mitigate this systematic to the point that it will not impede the detection of the cosmological power spectrum in the foreground avoidance scheme. First, variation in the ionospheric plasma density observed between different days produces attenuation of the effective <span class="hlt">polarized</span> power on the sky when visibilities are averaged coherently over many days. Second, the absolute level of <span class="hlt">polarization</span> leakage can be suppressed through careful design of the instrument. We have performed detailed visibility simulations to investigate both effects, and present the results of these simulations for both the HERA and PAPER instruments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/9045484','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/9045484"><span>[The possibility for using the phenomenon of <span class="hlt">polarized</span> light interference in treating amblyopia].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abramov, V G; Vakurina, A E; Kashchenko, T P; Pargina, N M</p> <p>1996-01-01</p> <p>A new method for treating amblyopia is proposed, making use of the phenomenon of <span class="hlt">polarized</span> light interference. It helps act simultaneously on the <span class="hlt">brightness</span>, contrast frequency, and color sensitivity in response to patterns. The method was used in the treatment of 36 children. In group 1 (n = 20) it was combined with the traditional methods. Such treatment was more effective than in controls treated routinely. Group 2 consisted of 16 children in whom previous therapy was of no avail. Visual function was improved in 7 of them.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1193632-double-spin-asymmetries-inclusive-hadron-electroproductions-from-transversely-polarized-he-target','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1193632-double-spin-asymmetries-inclusive-hadron-electroproductions-from-transversely-polarized-he-target"><span>Double spin asymmetries of inclusive hadron electroproductions from a transversely <span class="hlt">polarized</span> ³He target</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Zhao, Yuxiang X.</p> <p>2015-07-14</p> <p>We report the measurement of beam-target double-spin asymmetries A LT in the inclusive production of identified hadrons, e +³He ↑ → h + X, using a longitudinally <span class="hlt">polarized</span> 5.9 GeV electron beam and a transversely <span class="hlt">polarized</span> ³He target. Hadrons (π ±, K ± and proton) were detected at 16° with an average momentum h>=2.35 GeV/c and a transverse momentum (p T) coverage from 0.60 to 0.68 GeV/c. Asymmetries from the ³He target were observed to be non-zero for π ± production when the target was <span class="hlt">polarized</span> transversely in the <span class="hlt">horizontal</span> plane. The π⁺ and π⁻ asymmetries have opposite signs, analogousmore » to the behavior of A LT in semi-inclusive deep-inelastic scattering.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/biblio/22518571-ubiquitous-presence-looplike-fine-structure-inside-solar-active-regions','SCIGOV-STC'); return false;" href="https://www.osti.gov/biblio/22518571-ubiquitous-presence-looplike-fine-structure-inside-solar-active-regions"><span>THE UBIQUITOUS PRESENCE OF LOOPLIKE FINE STRUCTURE INSIDE SOLAR ACTIVE REGIONS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Wang, Y.-M., E-mail: yi.wang@nrl.navy.mil</p> <p></p> <p>Although most of the solar surface outside active regions (ARs) is pervaded by small-scale fields of mixed <span class="hlt">polarity</span>, this magnetic “carpet” or “junkyard” is thought to be largely absent inside AR plages and strong network. However, using extreme-ultraviolet images and line-of-sight magnetograms from the Solar Dynamics Observatory, we find that unipolar flux concentrations, both inside and outside ARs, often have small, loop-shaped Fe ix 17.1 and Fe xii 19.3 nm features embedded within them, even though no minority-<span class="hlt">polarity</span> flux is visible in the corresponding magnetograms. Such looplike structures, characterized by <span class="hlt">horizontal</span> sizes of ∼3–5 Mm and varying on timescales ofmore » minutes or less, are seen inside <span class="hlt">bright</span> 17.1 nm moss, as well as in fainter moss-like regions associated with weaker network outside ARs. We also note a tendency for <span class="hlt">bright</span> coronal loops to show compact, looplike features at their footpoints. Based on these observations, we suggest that present-day magnetograms may be substantially underrepresenting the amount of minority-<span class="hlt">polarity</span> flux inside plages and strong network, and that reconnection between small bipoles and the overlying large-scale field could be a major source of coronal heating both in ARs and in the quiet Sun.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760003464','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760003464"><span>A radiative transfer model for microwave emissions from bare agricultural soils</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burke, W. J.; Paris, J. F.</p> <p>1975-01-01</p> <p>A radiative transfer model for microwave emissions from bare, stratified agricultural soils was developed to assist in the analysis of data gathered in the joint soil moisture experiment. The predictions of the model were compared with preliminary X band (2.8 cm) microwave and ground based observations. Measured <span class="hlt">brightness</span> temperatures at vertical and <span class="hlt">horizontal</span> <span class="hlt">polarizations</span> can be used to estimate the moisture content of the top centimeter of soil with + or - 1 percent accuracy. It is also shown that the Stokes parameters can be used to distinguish between moisture and surface roughness effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100001361','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100001361"><span>Low-Profile, Dual-Wavelength, Dual-<span class="hlt">Polarized</span> Antenna</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Carswell, James R.</p> <p>2010-01-01</p> <p>A single-aperture, low-profile antenna design has been developed that supports dual-<span class="hlt">polarization</span> and simultaneous operation at two wavelengths. It realizes multiple beams in the elevation plane, and supports radiometric, radar, and conical scanning applications. This antenna consists of multiple azimuth sticks, with each stick being a multilayer, hybrid design. Each stick forms the h-plane pattern of the C and Ku-band vertically and <span class="hlt">horizontally</span> <span class="hlt">polarized</span> antenna beams. By combining several azimuth sticks together, the elevation beam is formed. With a separate transceiver for each stick, the transmit phase and amplitude of each stick can be controlled to synthesize a beam at a specific incidence angle and to realize a particular side-lobe pattern. By changing the transmit phase distribution through the transceivers, the transmit antenna beam can be steered to different incidence angles. By controlling the amplitude distribution, different side lobe patterns and efficiencies can be realized. The receive beams are formed using digital beam synthesis techniques, resulting in very little loss in the receive path, thus enabling a very-low loss receive antenna to support passive measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040085680','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040085680"><span>Interannual Comparison of Water Vapor in the North <span class="hlt">Polar</span> Region of Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tamppari, L. K.; Smith, M. D.; Hale, A. S.; Bass, D. S.</p> <p>2003-01-01</p> <p>In order to better understand the current climate of Mars, we seek to understand atmospheric water in the north <span class="hlt">polar</span> region. Our approach is to examine the water transport and cycling issues within the north <span class="hlt">polar</span> region and in/out of the region on seasonal and annual timescales. Viking Mars Atmospheric Water Detector (MAWD) data showed that water vapor increased as the northern summer season progressed and temperatures increased, and that vapor appeared to be transported southward . However, there has been uncertainty about the amount of water cycling in and out of the north <span class="hlt">polar</span> region, as evidenced by residual <span class="hlt">polar</span> cap visible <span class="hlt">brightness</span> changes between one Martian year (Mariner 9 data) and a subsequent year (Viking data). These changes were originally thought to be interannual variations in the amount of frost sublimed based on global dust storm activity . However, Viking thermal and imaging data were re-examined and it was found that 14-35 pr m of water -ice appeared to be deposited on the cap later in the summer season, indicating that some water may be retained and redistributed within the <span class="hlt">polar</span> cap region. This late summer deposition could be due to adsorption directly onto the cap surface or due to snowfall. We seek to understand what happens to the water on seasonal and interannual timescales. We address these issues by examining water vapor in the north <span class="hlt">polar</span> region of Mars during the north spring and summer period from MGS TES data and by comparing these results to the Viking MAWD results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100022073&hterms=dynamo&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddynamo','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100022073&hterms=dynamo&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddynamo"><span><span class="hlt">Polar</span> Coronal Hole Ephemeral Regions, the Fast Solar Wind and the Global Magnetic Dynamo</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cirtain, Jonathan W.</p> <p>2010-01-01</p> <p>The X-Ray Telescope aboard Hinode has been regularly observing both the north and south solar <span class="hlt">polar</span> coronal holes from November 2006 through March 2009. We use the observations of emerged flux regions within the coronal hole as evidenced by small x-ray <span class="hlt">bright</span> points to study the physical properties of these regions. The width of the emerged flux region loop footpoints, the duration of the x-ray emission lifetime for the emerged flux region, the latitude of formation and whether an x-ray or EUV jet was observed were all recorded. In the present work we detail these observations and show a dependence on the width of the emerged flux region (<span class="hlt">bright</span> point) to the number of x-ray jets observed. The distribution of base width is then related to a power law for number of emerged flux regions as a function of base width.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018MNRAS.tmp.1426P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018MNRAS.tmp.1426P"><span>Asynchronous <span class="hlt">polar</span> V1500 Cyg: orbital, spin and beat periods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pavlenko, E. P.; Mason, P. A.; Sosnovskij, A. A.; Shugarov, S. Yu; Babina, Ju V.; Antonyuk, K. A.; Andreev, M. V.; Pit, N. V.; Antonyuk, O. I.; Baklanov, A. V.</p> <p>2018-06-01</p> <p>The <span class="hlt">bright</span> Nova Cygni 1975 is a rare nova on a magnetic white dwarf (WD). Later it was found to be an asynchronous <span class="hlt">polar</span>, now called V1500 Cyg. Our multisite photometric campaign occurring 40 years post eruption covered 26-nights (2015-2017). The reflection effect from the heated donor has decreased, but still dominates the optical radiation with an amplitude ˜1m.5. The 0m.3 residual reveals cyclotron emission and ellipsoidal variations. Mean <span class="hlt">brightness</span> modulation from night-to-night is used to measure the 9.6-d spin-orbit beat period that is due to changing accretion geometry including magnetic pole-switching of the flow. By subtracting the orbital and beat frequencies, spin-phase dependent light curves are obtained. The amplitude and profile of the WD spin light curves track the cyclotron emitting accretion regions on the WD and they vary systematically with beat phase. A weak intermittent signal at 0.137613-d is likely the spin period, which is 1.73(1) min shorter than the orbital period. The O-C diagram of light curve maxima displays phase jumps every one-half beat period, a characteristic of asynchronous <span class="hlt">polars</span>. The first jump we interpret as pole switching between regions separated by 180°. Then the spot drifts during ˜ 0.1 beat phase before undergoing a second phase jump between spots separated by less than 180°. We trace the cooling of the still hot WD as revealed by the irradiated companion. The post nova evolution and spin-orbit asynchronism of V1500 Cyg continues to be a powerful laboratory for accretion flows onto magnetic white dwarfs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.P24A..05T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.P24A..05T"><span><span class="hlt">Bright</span> Fans in Mars Cryptic Region Caused by Adiabatic Cooling of CO2 Gas Jets.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Titus, T. N.; Kieffer, H. H.; Langevin, Y.; Murchie, S.; Seelos, F.; Vincendon, M.</p> <p>2007-12-01</p> <p>Over the last decade, observations of the retreat of the southern seasonal cap of Mars have revealed the presence of exotic processes within an area now informally referred to as the cryptic region. The appearance of dark spots, fans, blotches, and halos have been a "hot" topic of scientific discussion since they were first observed by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) [Malin et al., 1998]. Further observations by the Mars Odyssey (ODY) Thermal Emission Imaging System (THEMIS) showed that the dark features remained cold throughout the early-to-mid spring, suggesting that these features were either CO2 ice or were in thermal contact with CO2 ice [Kieffer et al., 2006]. In this paper, we present observations in the near-infrared at spatial resolutions that have previously been unavailable. We present further evidence that many of these features in the cryptic region are the result of cold jets, as first described by Kieffer [2000, 2007]. The adiabatic cooling of gas spewing downwind from the jets produces CO2 frost, thus forming the <span class="hlt">bright</span> fans. The <span class="hlt">bright</span> fans appear to be devoid of H2O ice, thus further supporting the hypothesis that they are formed from the downwind settling of CO2 frost. In some areas, the <span class="hlt">bright</span> fans are adjacent to dark fans and appear to start from common vertices, while in other areas, <span class="hlt">bright</span> fan-like deposits occur without the strong presence of dark fans. References: Kieffer, H.H. (2000) Annual Punctuated CO2 Slab-Ice and Jets on Mars, International Conference on Mars <span class="hlt">Polar</span> Science and Exploration, p. 93. Kieffer, H.H. et al. (2006) Nature, 442,793-796. Kieffer, H.H. (2007) JGR, in press. Malin, M.C., M.H. Carr, G.E. Danielson, M.E. Davies, W.K. Hartmann, A.P. Ingersoll, P.B. James, H. Masursky, A.S. McEwen, L.A. Soderblom, P. Thomas, J. Veverka, M.A. Caplinger, M.A. Ravine, and T.A. Soulanille (1998) Early views of the Martian surface from the Mars orbiter camera of Mars global surveyor, Science, 279, 1681-1685.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970022296','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970022296"><span>Adaptive Identification and Characterization of <span class="hlt">Polar</span> Ionization Patches</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coley, W. R.; Heelis, R. A.</p> <p>1995-01-01</p> <p>Dynamics Explorer 2 (DE 2) spacecraft data are used to detect and characterize <span class="hlt">polar</span> cap 'ionization patches' loosely defined as large-scale (greater than 100 km) regions where the F region plasma density is significantly enhanced (approx greater than 100%) above the background level. These patches are generally believed to develop in or equatorward of the dayside cusp region and then drift in an antisunward direction over the <span class="hlt">polar</span> cap. We have developed a flexible algorithm for the identification and characterization of these structures, as a function of scale-size and density enhancement, using data from the retarding potential analyzer, the ion drift meter, and the langmuir probe on board the DE 2 satellite. This algorithm was used to study the structure and evolution of ionization patches as they cross the <span class="hlt">polar</span> cap. The results indicate that in the altitude region from 240 to 950 km ion density enhancements greater than a factor of 3 above the background level are relatively rare. Further, the ionization patches show a preferred <span class="hlt">horizontal</span> scale size of 300-400 km. There exists a clear seasonal and universal time dependence to the occurrence frequency of patches with a northern hemisphere maximum centered on the winter solstice and the 1200-2000 UT interval.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AAS...20915406C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AAS...20915406C"><span>A New Sky <span class="hlt">Brightness</span> Monitor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crawford, David L.; McKenna, D.</p> <p>2006-12-01</p> <p>A good estimate of sky <span class="hlt">brightness</span> and its variations throughout the night, the months, and even the years is an essential bit of knowledge both for good observing and especially as a tool in efforts to minimize sky <span class="hlt">brightness</span> through local action. Hence a stable and accurate monitor can be a valuable and necessary tool. We have developed such a monitor, with the financial help of Vatican Observatory and Walker Management. The device is now undergoing its Beta test in preparation for production. It is simple, accurate, well calibrated, and automatic, sending its data directly to IDA over the internet via E-mail . Approximately 50 such monitors will be ready soon for deployment worldwide including most major observatories. Those interested in having one should enquire of IDA about details.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24329024','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24329024"><span>Normal dimensions of the posterior pituitary <span class="hlt">bright</span> spot on magnetic resonance imaging.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Côté, Martin; Salzman, Karen L; Sorour, Mohammad; Couldwell, William T</p> <p>2014-02-01</p> <p>The normal pituitary <span class="hlt">bright</span> spot seen on unenhanced T1-weighted MRI is thought to result from the T1-shortening effect of the vasopressin stored in the posterior pituitary. Individual variations in its size may be difficult to differentiate from pathological conditions resulting in either absence of the pituitary <span class="hlt">bright</span> spot or in T1-hyperintense lesions of the sella. The objective of this paper was to define a range of normal dimensions of the pituitary <span class="hlt">bright</span> spot and to illustrate some of the most commonly encountered pathologies that result in absence or enlargement of the pituitary <span class="hlt">bright</span> spot. The authors selected normal pituitary MRI studies from 106 patients with no pituitary abnormality. The size of each pituitary <span class="hlt">bright</span> spot was measured in the longest axis and in the dimension perpendicular to this axis to describe the typical dimensions. The authors also present cases of patients with pituitary abnormalities to highlight the differences and potential overlap between normal and pathological pituitary imaging. All of the studies evaluated were found to have pituitary <span class="hlt">bright</span> spots, and the mean dimensions were 4.8 mm in the long axis and 2.4 mm in the short axis. The dimension of the pituitary <span class="hlt">bright</span> spot in the long axis decreased with patient age. The distribution of dimensions of the pituitary <span class="hlt">bright</span> spot was normal, indicating that 99.7% of patients should have a pituitary <span class="hlt">bright</span> spot measuring between 1.2 and 8.5 mm in its long axis and between 0.4 and 4.4 mm in its short axis, an interval corresponding to 3 standard deviations below and above the mean. In cases where the dimension of the pituitary <span class="hlt">bright</span> spot is outside this range, pathological conditions should be considered. The pituitary <span class="hlt">bright</span> spot should always be demonstrated on T1-weighted MRI, and its dimensions should be within the identified normal range in most patients. Outside of this range, pathological conditions affecting the pituitary <span class="hlt">bright</span> spot should be considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25339931','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25339931"><span>Effects of saturation and contrast <span class="hlt">polarity</span> on the figure-ground organization of color on gray.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dresp-Langley, Birgitta; Reeves, Adam</p> <p>2014-01-01</p> <p>Poorly saturated colors are closer to a pure gray than strongly saturated ones and, therefore, appear less "colorful."Color saturation is effectively manipulated in the visual arts for balancing conflicting sensations and moods and for inducing the perception of relative distance in the pictorial plane. While perceptual science has proven quite clearly that the luminance contrast of any hue acts as a self-sufficient cue to relative depth in visual images, the role of color saturation in such figure-ground organization has remained unclear. We presented configurations of colored inducers on gray "test" backgrounds to human observers. Luminance and saturation of the inducers was uniform on each trial, but varied across trials. We ran two separate experimental tasks. In the relative background <span class="hlt">brightness</span> task, perceptual judgments indicated whether the apparent <span class="hlt">brightness</span> of the gray test background contrasted with, assimilated to, or appeared equal (no effect) to that of a comparison background with the same luminance contrast. Contrast <span class="hlt">polarity</span> and its interaction with color saturation affected response proportions for contrast, assimilation and no effect. In the figure-ground task, perceptual judgments indicated whether the inducers appeared to lie in front of, behind, or in the same depth with the background. Strongly saturated inducers produced significantly larger proportions of foreground effects indicating that these inducers stand out as figure against the background. Weakly saturated inducers produced significantly larger proportions of background effects, indicating that these inducers are perceived as lying behind the backgrounds. We infer that color saturation modulates figure-ground organization, both directly by determining relative inducer depth, and indirectly, and in interaction with contrast <span class="hlt">polarity</span>, by affecting apparent background <span class="hlt">brightness</span>. The results point toward a hitherto undocumented functional role of color saturation in the genesis of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4187611','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4187611"><span>Effects of saturation and contrast <span class="hlt">polarity</span> on the figure-ground organization of color on gray</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dresp-Langley, Birgitta; Reeves, Adam</p> <p>2014-01-01</p> <p>Poorly saturated colors are closer to a pure gray than strongly saturated ones and, therefore, appear less “colorful.”Color saturation is effectively manipulated in the visual arts for balancing conflicting sensations and moods and for inducing the perception of relative distance in the pictorial plane. While perceptual science has proven quite clearly that the luminance contrast of any hue acts as a self-sufficient cue to relative depth in visual images, the role of color saturation in such figure-ground organization has remained unclear. We presented configurations of colored inducers on gray “test” backgrounds to human observers. Luminance and saturation of the inducers was uniform on each trial, but varied across trials. We ran two separate experimental tasks. In the relative background <span class="hlt">brightness</span> task, perceptual judgments indicated whether the apparent <span class="hlt">brightness</span> of the gray test background contrasted with, assimilated to, or appeared equal (no effect) to that of a comparison background with the same luminance contrast. Contrast <span class="hlt">polarity</span> and its interaction with color saturation affected response proportions for contrast, assimilation and no effect. In the figure-ground task, perceptual judgments indicated whether the inducers appeared to lie in front of, behind, or in the same depth with the background. Strongly saturated inducers produced significantly larger proportions of foreground effects indicating that these inducers stand out as figure against the background. Weakly saturated inducers produced significantly larger proportions of background effects, indicating that these inducers are perceived as lying behind the backgrounds. We infer that color saturation modulates figure-ground organization, both directly by determining relative inducer depth, and indirectly, and in interaction with contrast <span class="hlt">polarity</span>, by affecting apparent background <span class="hlt">brightness</span>. The results point toward a hitherto undocumented functional role of color saturation in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24672472','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24672472"><span><span class="hlt">Polarity</span>-specific high-level information propagation in neural networks.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lin, Yen-Nan; Chang, Po-Yen; Hsiao, Pao-Yueh; Lo, Chung-Chuan</p> <p>2014-01-01</p> <p>Analyzing the connectome of a nervous system provides valuable information about the functions of its subsystems. Although much has been learned about the architectures of neural networks in various organisms by applying analytical tools developed for general networks, two distinct and functionally important properties of neural networks are often overlooked. First, neural networks are endowed with <span class="hlt">polarity</span> at the circuit level: Information enters a neural network at input neurons, propagates through interneurons, and leaves via output neurons. Second, many functions of nervous systems are implemented by signal propagation through high-level pathways involving multiple and often recurrent connections rather than by the shortest paths between nodes. In the present study, we analyzed two neural networks: the somatic nervous system of Caenorhabditis elegans (C. elegans) and the partial central complex network of Drosophila, in light of these properties. Specifically, we quantified high-level propagation in the vertical and <span class="hlt">horizontal</span> directions: the former characterizes how signals propagate from specific input nodes to specific output nodes and the latter characterizes how a signal from a specific input node is shared by all output nodes. We found that the two neural networks are characterized by very efficient vertical and <span class="hlt">horizontal</span> propagation. In comparison, classic small-world networks show a trade-off between vertical and <span class="hlt">horizontal</span> propagation; increasing the rewiring probability improves the efficiency of <span class="hlt">horizontal</span> propagation but worsens the efficiency of vertical propagation. Our result provides insights into how the complex functions of natural neural networks may arise from a design that allows them to efficiently transform and combine input signals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3955877','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3955877"><span><span class="hlt">Polarity</span>-specific high-level information propagation in neural networks</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lin, Yen-Nan; Chang, Po-Yen; Hsiao, Pao-Yueh; Lo, Chung-Chuan</p> <p>2014-01-01</p> <p>Analyzing the connectome of a nervous system provides valuable information about the functions of its subsystems. Although much has been learned about the architectures of neural networks in various organisms by applying analytical tools developed for general networks, two distinct and functionally important properties of neural networks are often overlooked. First, neural networks are endowed with <span class="hlt">polarity</span> at the circuit level: Information enters a neural network at input neurons, propagates through interneurons, and leaves via output neurons. Second, many functions of nervous systems are implemented by signal propagation through high-level pathways involving multiple and often recurrent connections rather than by the shortest paths between nodes. In the present study, we analyzed two neural networks: the somatic nervous system of Caenorhabditis elegans (C. elegans) and the partial central complex network of Drosophila, in light of these properties. Specifically, we quantified high-level propagation in the vertical and <span class="hlt">horizontal</span> directions: the former characterizes how signals propagate from specific input nodes to specific output nodes and the latter characterizes how a signal from a specific input node is shared by all output nodes. We found that the two neural networks are characterized by very efficient vertical and <span class="hlt">horizontal</span> propagation. In comparison, classic small-world networks show a trade-off between vertical and <span class="hlt">horizontal</span> propagation; increasing the rewiring probability improves the efficiency of <span class="hlt">horizontal</span> propagation but worsens the efficiency of vertical propagation. Our result provides insights into how the complex functions of natural neural networks may arise from a design that allows them to efficiently transform and combine input signals. PMID:24672472</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/825354','DOE-PATENT-XML'); return false;" href="https://www.osti.gov/servlets/purl/825354"><span><span class="hlt">Horizontal</span> Advanced Tensiometer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Hubbell, Joel M.; Sisson, James B.</p> <p>2004-06-22</p> <p>An <span class="hlt">horizontal</span> advanced tensiometer is described that allows the monitoring of the water pressure of soil positions, particularly beneath objects or materials that inhibit the use of previous monitoring wells. The tensiometer includes a porous cup, a pressure transducer (with an attached gasket device), an adaptive chamber, at least one outer guide tube which allows access to the desired <span class="hlt">horizontal</span> position, a transducer wire, a data logger and preferably an inner guide tube and a specialized joint which provides pressure on the inner guide tube to maintain the seal between the gasket of the transducer and the adaptive chamber.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21196966','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21196966"><span><span class="hlt">Brightness</span> field distributions of microlens arrays using micro molding.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cheng, Hsin-Chung; Huang, Chiung-Fang; Lin, Yi; Shen, Yung-Kang</p> <p>2010-12-20</p> <p>This study describes the <span class="hlt">brightness</span> field distributions of microlens arrays fabricated by micro injection molding (μIM) and micro injection-compression molding (μICM). The process for fabricating microlens arrays used room-temperature imprint lithography, photoresist reflow, electroforming, μIM, μICM, and optical properties measurement. Analytical results indicate that the <span class="hlt">brightness</span> field distribution of the molded microlens arrays generated by μICM is better than those made using μIM. Our results further demonstrate that mold temperature is the most important processing parameter for <span class="hlt">brightness</span> field distribution of molded microlens arrays made by μIM or μICM.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=cross+AND+cultural+AND+social+AND+skills&pg=7&id=EJ777087','ERIC'); return false;" href="https://eric.ed.gov/?q=cross+AND+cultural+AND+social+AND+skills&pg=7&id=EJ777087"><span>Star<span class="hlt">Bright</span> Learning Exchange</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kalinowski, Michael</p> <p>2007-01-01</p> <p>This article features Star<span class="hlt">Bright</span> Learning Exchange, a program that provides a cross-cultural exchange between Australian and South African early childhood educators. The program was originated when its president, Carol Allen, and her colleague, Karen Williams, decided that they could no longer sit by and watch the unfolding social catastrophe that…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/1342752','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/1342752"><span>High <span class="hlt">Brightness</span> OLED Lighting</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Spindler, Jeffrey; Kondakova, Marina; Boroson, Michael</p> <p>2016-05-25</p> <p>In this work we describe the technology developments behind our current and future generations of high <span class="hlt">brightness</span> OLED lighting panels. We have developed white and amber OLEDs with excellent performance based on the stacking approach. Current products achieve 40-60 lm/W, while future developments focus on achieving 80 lm/W or higher.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/29698847','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/29698847"><span>The universal and automatic association between <span class="hlt">brightness</span> and positivity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Specker, Eva; Leder, Helmut; Rosenberg, Raphael; Hegelmaier, Lisa Mira; Brinkmann, Hanna; Mikuni, Jan; Kawabata, Hideaki</p> <p>2018-05-01</p> <p>The present study investigates the hypothesis that <span class="hlt">brightness</span> of colors is associated with positivity, postulating that this is an automatic and universal effect. The Implicit Association Test (IAT; Greenwald, McGhee, & Schwartz, 1998) was used in all studies. Study 1 used color patches varying on <span class="hlt">brightness</span>, Study 2 used achromatic stimuli to eliminate the potential confounding effects of hue and saturation. Study 3 replicated Study 2 in a different cultural context (Japan vs. Austria), both studies also included a measure of explicit association. All studies confirmed the hypothesis that <span class="hlt">brightness</span> is associated with positivity, at a significance level of p < .001 and Cohen's D varying from 0.90 to 3.99. Study 1-3 provided support for the notion that this is an automatic effect. Additionally, Study 2 and Study 3 showed that people also have an explicit association of <span class="hlt">brightness</span> with positivity. However, as expected, our results also show that the implicit association was stronger than the explicit association. Study 3 shows clear support for the universality of our effects. In sum, our results support the idea that <span class="hlt">brightness</span> is associated with positivity and that these associations are automatic and universal. Copyright © 2018 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JPhCS.425c2011L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JPhCS.425c2011L"><span>Developments in <span class="hlt">Polarization</span> and Energy Control of APPLE-II Undulators at Diamond Light Source</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Longhi, E. C.; Bencok, P.; Dobrynin, A.; Rial, E. C. M.; Rose, A.; Steadman, P.; Thompson, C.; Thomson, A.; Wang, H.</p> <p>2013-03-01</p> <p>A pair of 2m long APPLE-II type undulators have been built for the I10 BLADE beamline at Diamond Light Source. These 48mm period devices have gap as well as four moveable phase axes which provide the possibility to produce the full range of elliptical <span class="hlt">polarizations</span> as well as linear <span class="hlt">polarization</span> tilted through a full 180deg. The mechanical layout chosen has a 'master and slave' arrangement of the phase axes on the top and bottom. This arrangement allows the use of symmetries to provide operational ease for both changing energy using only the master phase while keeping fixed linear <span class="hlt">horizontal</span> or circular <span class="hlt">polarization</span>, as well as changing linear <span class="hlt">polarization</span> angle while keeping fixed energy [1]. The design allows very fast motion of the master phase arrays, without sacrifice of accuracy, allowing the possibility of mechanical <span class="hlt">polarization</span> switching at 1Hz for dichroism experiments. We present the mechanical design features of these devices, as well as the results of magnetic measurements and shimming from before installation. Finally, we present the results of characterization of these devices by the beamline, including polarimetry, which has been done on the various modes of motion to control energy and <span class="hlt">polarization</span>. These modes of operation have been available to users since 2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA02300&hterms=snow+leopard&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsnow%2Bleopard','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA02300&hterms=snow+leopard&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsnow%2Bleopard"><span>Defrosting <span class="hlt">Polar</span> Dunes--'They Look Like Bushes!'</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1999-01-01</p> <p><p/>'They look like bushes!' That's what almost everyone says when they see the dark features found in pictures taken of sand dunes in the <span class="hlt">polar</span> regions as they are beginning to defrost after a long, cold winter. It is hard to escape the fact that, at first glance, these images acquired by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) over both <span class="hlt">polar</span> regions during the spring and summer seasons, do indeed resemble aerial photographs of sand dune fields on Earth--complete with vegetation growing on and around them! Of course, this is not what the features are, as we describe below and in related picture captions. Still, don't they look like vegetation to you? Shown here are two views of the same MGS MOC image. On the left is the full scene, on the right is an expanded view of a portion of the scene on the left. The <span class="hlt">bright</span>, smooth surfaces that are dotted with occasional, nearly triangular dark spots are sand dunes covered by winter frost. <p/>The MGS MOC has been used over the past several months (April-August 1999) to monitor dark spots as they form and evolve on <span class="hlt">polar</span> dune surfaces. The dark spots typically appear first along the lower margins of a dune--similar to the position of bushes and tufts of grass that occur in and among some sand dunes on Earth. <p/>Because the martian air pressure is very low--100 times lower than at Sea Level on Earth--ice on Mars does not melt and become liquid when it warms up. Instead, ice sublimes--that is, it changes directly from solid to gas, just as 'dry ice' does on Earth. As <span class="hlt">polar</span> dunes emerge from the months-long winter night, and first become exposed to sunlight, the <span class="hlt">bright</span> winter frost and snow begins to sublime. This process is not uniform everywhere on a dune, but begins in small spots and then over several months it spreads until the entire dune is spotted like a leopard. <p/>The early stages of the defrosting process--as in the picture shown here--give the impression that something is 'growing' on the dunes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900038306&hterms=Frost&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DFrost','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900038306&hterms=Frost&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DFrost"><span>Mariner 9 observations of the south <span class="hlt">polar</span> cap of Mars - Evidence for residual CO2 frost</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Paige, D. A.; Herkenhoff, K. E.; Murray, B. C.</p> <p>1990-01-01</p> <p>The first spacecraft observations of the south residual <span class="hlt">polar</span> cap of Mars were obtained by the Mariner 9 orbiter during the Martian southern summer season, 1971-1972. Analyses of Viking orbiter observations obtained 3 Mars years later have shown that residual carbon dioxide frost was present at the south <span class="hlt">polar</span> cap in 1977. In this study, Mariner 9 infrared interferometer spectrometer spectra and television camera images are used in conjuction with multispectral thermal emission models to constrain the temperatures of dark bare ground and <span class="hlt">bright</span> frost regions within the south residual cap. The results provide strong evidence that carbon dioxide frost was present throughout the summer season despite the fact that the residual frost deposits observed by Mariner 9 were less extensive than those observed by Viking.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160014831','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160014831"><span>Evaluation of the Minifilament-Eruption Scenario for Solar Coronal Jets in <span class="hlt">Polar</span> Coronal Holes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Baikie, Tomi K.; Sterling, Alphonse C.; Falconer, David; Moore, Ronald L.; Savage, Sabrina L.</p> <p>2016-01-01</p> <p>Solar coronal jets are suspected to result from magnetic reconnection low in the Sun's atmosphere. Sterling et al. (2015) looked as 20 jets in <span class="hlt">polar</span> coronal holes, using X-ray images from the Hinode/X-Ray Telescope (XRT) and EUV images from the Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA). They suggested that each jet was driven by the eruption of twisted closed magnetic field carrying a small-scale filament, which they call a 'minifilament', and that the jet was produced by reconnection of the erupting field with surrounding open field. In this study, we carry out a more extensive examination of <span class="hlt">polar</span> coronal jets. From 180 hours of XRT <span class="hlt">polar</span> coronal hole observations spread over two years (2014-2016), we identified 130 clearly-identifiable X-ray jet events and thus determined an event rate of over 17 jets per day per in the Hinode/XRT field of view. From the broader set, we selected 25 of the largest and brightest events for further study in AIA 171, 193, 211, and 304 Angstrom images. We find that at least the majority of the jets follow the minifilament-eruption scenario, although for some cases the evolution of the minifilament in the onset of its eruption is more complex than presented in the simplified schematic of Sterling et al. (2015). For all cases in which we could make a clear determination, the spire of the X-ray jet drifted laterally away from the jet-base-edge <span class="hlt">bright</span> point; this spire drift away from the <span class="hlt">bright</span> point is consistent with expectations of the minifilament-eruption scenario for coronal-jet production. This work was supported with funding from the NASA/MSFC Hinode Project Office, and from the NASA HGI program.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/servlets/purl/111434','SCIGOV-STC'); return false;" href="https://www.osti.gov/servlets/purl/111434"><span><span class="hlt">Horizontal</span> steam generator thermal-hydraulics</span></a></p> <p><a target="_blank" href="http://www.osti.gov/search">DOE Office of Scientific and Technical Information (OSTI.GOV)</a></p> <p>Ubra, O.; Doubek, M.</p> <p>1995-09-01</p> <p><span class="hlt">Horizontal</span> steam generators are typical components of nuclear power plants with pressure water reactor type VVER. Thermal-hydraulic behavior of <span class="hlt">horizontal</span> steam generators is very different from the vertical U-tube steam generator, which has been extensively studied for several years. To contribute to the understanding of the <span class="hlt">horizontal</span> steam generator thermal-hydraulics a computer program for 3-D steady state analysis of the PGV-1000 steam generator has been developed. By means of this computer program, a detailed thermal-hydraulic and thermodynamic study of the <span class="hlt">horizontal</span> steam generator PGV-1000 has been carried out and a set of important steam generator characteristics has been obtained. Themore » 3-D distribution of the void fraction and 3-D level profile as functions of load and secondary side pressure have been investigated and secondary side volumes and masses as functions of load and pressure have been evaluated. Some of the interesting results of calculations are presented in the paper.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018NJPh...20c3009H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018NJPh...20c3009H"><span>Quantum noise in <span class="hlt">bright</span> soliton matterwave interferometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haine, Simon A.</p> <p>2018-03-01</p> <p>There has been considerable recent interest in matterwave interferometry with <span class="hlt">bright</span> solitons in quantum gases with attractive interactions, for applications such as rotation sensing. We model the quantum dynamics of these systems and find that the attractive interactions required for the presence of <span class="hlt">bright</span> solitons causes quantum phase-diffusion, which severely impairs the sensitivity. We propose a scheme that partially restores the sensitivity, but find that in the case of rotation sensing, it is still better to work in a regime with minimal interactions if possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2018AnPhy.390..180W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2018AnPhy.390..180W"><span>Dynamics of <span class="hlt">bright-bright</span> solitons in Bose-Einstein condensate with Raman-induced one-dimensional spin-orbit coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wen, Lin; Zhang, Xiao-Fei; Hu, Ai-Yuan; Zhou, Jing; Yu, Peng; Xia, Lei; Sun, Qing; Ji, An-Chun</p> <p>2018-03-01</p> <p>We investigate the dynamics of <span class="hlt">bright-bright</span> solitons in one-dimensional two-component Bose-Einstein condensates with Raman-induced spin-orbit coupling, via the variational approximation and the numerical simulation of Gross-Pitaevskii equations. For the uniform system without trapping potential, we obtain two population balanced stationary solitons. By performing the linear stability analysis, we find a Goldstone eigenmode and an oscillation eigenmode around these stationary solitons. Moreover, we derive a general dynamical solution to describe the center-of-mass motion and spin evolution of the solitons under the action of spin-orbit coupling. The effects of a harmonic trap have also been discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900013552','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900013552"><span>The analysis of <span class="hlt">polar</span> clouds from AVHRR satellite data using pattern recognition techniques</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, William L.; Ebert, Elizabeth</p> <p>1990-01-01</p> <p>The cloud cover in a set of summertime and wintertime AVHRR data from the Arctic and Antarctic regions was analyzed using a pattern recognition algorithm. The data were collected by the NOAA-7 satellite on 6 to 13 Jan. and 1 to 7 Jul. 1984 between 60 deg and 90 deg north and south latitude in 5 spectral channels, at the Global Area Coverage (GAC) resolution of approximately 4 km. This data embodied a <span class="hlt">Polar</span> Cloud Pilot Data Set which was analyzed by a number of research groups as part of a <span class="hlt">polar</span> cloud algorithm intercomparison study. This study was intended to determine whether the additional information contained in the AVHRR channels (beyond the standard visible and infrared bands on geostationary satellites) could be effectively utilized in cloud algorithms to resolve some of the cloud detection problems caused by low visible and thermal contrasts in the <span class="hlt">polar</span> regions. The analysis described makes use of a pattern recognition algorithm which estimates the surface and cloud classification, cloud fraction, and surface and cloudy visible (channel 1) albedo and infrared (channel 4) <span class="hlt">brightness</span> temperatures on a 2.5 x 2.5 deg latitude-longitude grid. In each grid box several spectral and textural features were computed from the calibrated pixel values in the multispectral imagery, then used to classify the region into one of eighteen surface and/or cloud types using the maximum likelihood decision rule. A slightly different version of the algorithm was used for each season and hemisphere because of differences in categories and because of the lack of visible imagery during winter. The classification of the scene is used to specify the optimal AVHRR channel for separating clear and cloudy pixels using a hybrid histogram-spatial coherence method. This method estimates values for cloud fraction, clear and cloudy albedos and <span class="hlt">brightness</span> temperatures in each grid box. The choice of a class-dependent AVHRR channel allows for better separation of clear and cloudy pixels than</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009076','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009076"><span>L-Band H <span class="hlt">Polarized</span> Microwave Emission During the Corn Growth Cycle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Joseph, A. T.; va der Velde, R.; O'Neill, P. E.; Kim, E.; Lang, R. H.; Gish, T.</p> <p>2012-01-01</p> <p>Hourly L-band (1.4 GHz) <span class="hlt">horizontally</span> (H) <span class="hlt">polarized</span> <span class="hlt">brightness</span> temperatures (T(sub B))'s measured during five episodes (more than two days of continuous measurements) of the 2002 corn growth cycle are analyzed. These T(sub B)'s measurements were acquired as a part of a combined active/passive microwave field campaign, and were obtained at five incidence and three azimuth angles relative to the row direction. In support of this microwave data collection, intensive ground sampling took place once a week. Moreover, the interpretation of the hourly T(sub B)'s could also rely on the data obtained using the various automated instruments installed in the same field. In this paper, the soil moisture and temperature measured at fixed time intervals have been employed as input for the tau-omega model to reproduce the hourly T(sub B). Through the calibration of the vegetation and surface roughness parameterizations, the impact of the vegetation morphological changes on the microwave emission and the dependence of the soil surface roughness parameter, h(sub r), on soil moisture are investigated. This analysis demonstrates that the b parameter, appearing in the representation of the canopy opacity, has an angular dependence that varies throughout the growing period and also that the parameter hr increases as the soil dries in a portion of the dry-down cycle. The angular dependence of the b parameter imposes the largest uncertainty on T(sub B) simulations near senescence as the response of b to the incidence is also affected by the crop row orientation. On the other hand, the incorporation of a soil moisture dependent h(sub r) parameterization was responsible for the largest error reduction of T(sub B) simulations in the early growth cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PASP..128k5006D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PASP..128k5006D"><span>Gain and <span class="hlt">Polarization</span> Properties of a Large Radio Telescope from Calculation and Measurement: The John A. Galt Telescope</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Du, X.; Landecker, T. L.; Robishaw, T.; Gray, A. D.; Douglas, K. A.; Wolleben, M.</p> <p>2016-11-01</p> <p>Measurement of the <span class="hlt">brightness</span> temperature of extended radio emission demands knowledge of the gain (or aperture efficiency) of the telescope and measurement of the <span class="hlt">polarized</span> component of the emission requires correction for the conversion of unpolarized emission from sky and ground to apparently <span class="hlt">polarized</span> signal. Radiation properties of the John A. Galt Telescope at the Dominion Radio Astrophysical Observatory were studied through analysis and measurement in order to provide absolute calibration of a survey of <span class="hlt">polarized</span> emission from the entire northern sky from 1280 to 1750 MHz, and to understand the <span class="hlt">polarization</span> performance of the telescope. Electromagnetic simulation packages CST and GRASP-10 were used to compute complete radiation patterns of the telescope in all Stokes parameters, and thereby to establish gain and aperture efficiency. Aperture efficiency was also evaluated using geometrical optics and ray tracing analysis and was measured based on the known flux density of Cyg A. Measured aperture efficiency varied smoothly with frequency between values of 0.49 and 0.54; GRASP-10 yielded values 6.5% higher but with closely similar variation with frequency. Overall error across the frequency band is 3%, but values at any two frequencies are relatively correct to ˜1%. Dominant influences on aperture efficiency are the illumination taper of the feed radiation pattern and the shadowing of the reflector from the feed by the feed-support struts. A model of emission from the ground was developed based on measurements and on empirical data obtained from remote sensing of the Earth from satellite-borne telescopes. This model was convolved with the computed antenna response to estimate conversion of ground emission into spurious <span class="hlt">polarized</span> signal. The computed spurious signal is comparable to measured values, but is not accurate enough to be used to correct observations. A simpler model, in which the ground is considered as an unpolarized emitter with a <span class="hlt">brightness</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.er.usgs.gov/publication/70159370','USGSPUBS'); return false;" href="https://pubs.er.usgs.gov/publication/70159370"><span>The impact of bottom <span class="hlt">brightness</span> on spectral reflectance of suspended sediments</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Tolk, Brian L.; Han, L.; Rundquist, D. C.</p> <p>2000-01-01</p> <p>Two experiments were conducted outdoors to investigate how bottom <span class="hlt">brightness</span> impacts the spectral response of a water column under varied suspended sediment concentrations. A white aluminum panel placed at the bottom of the tank was used as the <span class="hlt">bright</span> bottom, and a flat-black tank liner served as the dark bottom. Sixteen levels of suspended sediment from 25 to 400 mg litre -1 were used in each experiment. Spectral data were collected using a Spectron SE-590 spectroradiometer. The major findings include the following: the <span class="hlt">bright</span> bottom had the greatest impact at visible wavelengths; when suspended sediment concentrations exceeded 100 mg litre -1, the <span class="hlt">bright</span> bottom response was found to be negligible; and, substrate <span class="hlt">brightness</span> has minimal impact between 740 and 900 nm, suggesting that these wavelengths are best for measuring suspended sediment concentrations by means of remote sensing.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009RELEA...8...51R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009RELEA...8...51R"><span>Study of the Local Horizon. (Spanish Title: Estudio del <span class="hlt">Horizonte</span> Local.) Estudo do <span class="hlt">Horizonte</span> Local</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ros, Rosa M.</p> <p>2009-12-01</p> <p>The study of the horizon is fundamental to easy the first observations of the students at any education center. A simple model, to be developed in each center, allows to easy the study and comprehension of the rudiments of astronomy. The constructed model is presented in turn as a simple equatorial clock, other models (<span class="hlt">horizontal</span> and vertical) may be constructed starting from it. El estudio del <span class="hlt">horizonte</span> es fundamental para poder facilitar las primeras observaciones de los alumnos en un centro educativo. Un simple modelo, que debe realizarse para cada centro, nos permite facilitar el estudio y la comprensión de los primeros rudimentos astronómicos. El modelo construido se presenta a su vez como un sencillo modelo de reloj ecuatorial y a partir de él se pueden construir otros modelos (<span class="hlt">horizontal</span> y vertical). O estudo do <span class="hlt">horizonte</span> é fundamental para facilitar as primeiras observações dos alunos num centro educativo. Um modelo simples, que deve ser feito para cada centro, permite facilitar o estudo e a compreensão dos primeiros rudimentos astronômicos. O modelo construído apresenta-se, por sua vez, como um modelo simples de relógio equatorial e a partir dele pode-se construir outros modelos (<span class="hlt">horizontal</span> e vertical)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25620199','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25620199"><span>Phase advancing human circadian rhythms with morning <span class="hlt">bright</span> light, afternoon melatonin, and gradually shifted sleep: can we reduce morning <span class="hlt">bright</span>-light duration?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Crowley, Stephanie J; Eastman, Charmane I</p> <p>2015-02-01</p> <p>Efficient treatments to phase-advance human circadian rhythms are needed to attenuate circadian misalignment and the associated negative health outcomes that accompany early-morning shift work, early school start times, jet lag, and delayed sleep phase disorder. This study compared three morning <span class="hlt">bright</span>-light exposure patterns from a single light box (to mimic home treatment) in combination with afternoon melatonin. Fifty adults (27 males) aged 25.9 ± 5.1 years participated. Sleep/dark was advanced 1 h/day for three treatment days. Participants took 0.5 mg of melatonin 5 h before the baseline bedtime on treatment day 1, and an hour earlier each treatment day. They were exposed to one of three <span class="hlt">bright</span>-light (~5000 lux) patterns upon waking each morning: four 30-min exposures separated by 30 min of room light (2-h group), four 15-min exposures separated by 45 min of room light (1-h group), and one 30-min exposure (0.5-h group). Dim-light melatonin onsets (DLMOs) before and after treatment determined the phase advance. Compared to the 2-h group (phase shift = 2.4 ± 0.8 h), smaller phase-advance shifts were seen in the 1-h (1.7 ± 0.7 h) and 0.5-h (1.8 ± 0.8 h) groups. The 2-h pattern produced the largest phase advance; however, the single 30-min <span class="hlt">bright</span>-light exposure was as effective as 1 h of <span class="hlt">bright</span> light spread over 3.25 h, and it produced 75% of the phase shift observed with 2 h of <span class="hlt">bright</span> light. A 30-min morning <span class="hlt">bright</span>-light exposure with afternoon melatonin is an efficient treatment to phase-advance human circadian rhythms. Copyright © 2014 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4344919','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4344919"><span>Phase advancing human circadian rhythms with morning <span class="hlt">bright</span> light, afternoon melatonin, and gradually shifted sleep: can we reduce morning <span class="hlt">bright</span> light duration?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Crowley, Stephanie J.; Eastman, Charmane I.</p> <p>2015-01-01</p> <p>OBJECTIVE Efficient treatments to phase advance human circadian rhythms are needed to attenuate circadian misalignment and the associated negative health outcomes that accompany early morning shift work, early school start times, jet lag, and delayed sleep phase disorder. This study compared three morning <span class="hlt">bright</span> light exposure patterns from a single light box (to mimic home treatment) in combination with afternoon melatonin. METHODS Fifty adults (27 males) aged 25.9±5.1 years participated. Sleep/dark was advanced 1 hour/day for 3 treatment days. Participants took 0.5 mg melatonin 5 hours before baseline bedtime on treatment day 1, and an hour earlier each treatment day. They were exposed to one of three <span class="hlt">bright</span> light (~5000 lux) patterns upon waking each morning: four 30-minute exposures separated by 30 minutes of room light (2 h group); four 15-minute exposures separated by 45 minutes of room light (1 h group), and one 30-minute exposure (0.5 h group). Dim light melatonin onsets (DLMOs) before and after treatment determined the phase advance. RESULTS Compared to the 2 h group (phase shift=2.4±0.8 h), smaller phase advance shifts were seen in the 1 h (1.7±0.7 h) and 0.5 h (1.8±0.8 h) groups. The 2-hour pattern produced the largest phase advance; however, the single 30-minute <span class="hlt">bright</span> light exposure was as effective as 1 hour of <span class="hlt">bright</span> light spread over 3.25 h, and produced 75% of the phase shift observed with 2 hours of <span class="hlt">bright</span> light. CONCLUSIONS A 30-minute morning <span class="hlt">bright</span> light exposure with afternoon melatonin is an efficient treatment to phase advance human circadian rhythms. PMID:25620199</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4376897','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4376897"><span>Lamp-Lit Bridges as Dual Light-Traps for the Night-Swarming Mayfly, Ephoron virgo: Interaction of <span class="hlt">Polarized</span> and Unpolarized Light Pollution</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Szaz, Denes; Horvath, Gabor; Barta, Andras; Robertson, Bruce A.; Farkas, Alexandra; Egri, Adam; Tarjanyi, Nikolett; Racz, Gergely; Kriska, Gyorgy</p> <p>2015-01-01</p> <p>Ecological photopollution created by artificial night lighting can alter animal behavior and lead to population declines and biodiversity loss. <span class="hlt">Polarized</span> light pollution is a second type of photopollution that triggers water-seeking insects to ovisposit on smooth and dark man-made objects, because they simulate the <span class="hlt">polarization</span> signatures of natural water bodies. We document a case study of the interaction of these two forms of photopollution by conducting observations and experiments near a lamp-lit bridge over the river Danube that attracts mass swarms of the mayfly Ephoron virgo away from the river to oviposit on the asphalt road of the bridge. Millions of mayflies swarmed near bridge-lights for two weeks. We found these swarms to be composed of 99% adult females performing their upstream compensatory flight and were attracted upward toward unpolarized bridge-lamp light, and away from the <span class="hlt">horizontally</span> <span class="hlt">polarized</span> light trail of the river. Imaging polarimetry confirmed that the asphalt surface of the bridge was strongly and <span class="hlt">horizontally</span> <span class="hlt">polarized</span>, providing a supernormal ovipositional cue to Ephoron virgo, while other parts of the bridge were poor <span class="hlt">polarizers</span> of lamplight. Collectively, we confirm that Ephoron virgo is independently attracted to both unpolarized and <span class="hlt">polarized</span> light sources, that both types of photopollution are being produced at the bridge, and that spatial patterns of swarming and oviposition are consistent with evolved behaviors being triggered maladaptively by these two types of light pollution. We suggest solutions to bridge and lighting design that should prevent or mitigate the impacts of such scenarios in the future. The detrimental impacts of such scenarios may extend beyond Ephoron virgo. PMID:25815748</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <div class="footer-extlink text-muted" style="margin-bottom:1rem; text-align:center;">Some links on this page may take you to non-federal websites. 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