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Sample records for absorption features arising

  1. Special Issue featuring invited articles arising from UK Semiconductors 2012

    NASA Astrophysics Data System (ADS)

    Clarke, Edmund; Wada, Osamu

    2013-07-01

    Semiconductor research has formed the basis of many technological advances over the past 50 years, and the field is still highly active, as new material systems and device concepts are developed to address new applications or operating conditions. In addition to the development of traditional semiconductor devices, the wealth of experience with these materials also allows their use as an ideal environment for testing new physics, leading to new classes of devices exploiting quantum mechanical effects that can also benefit from the advantages of existing semiconductor technology in scalability, compactness and ease of mass production. This special issue features papers arising from the UK Semiconductors 2012 Conference, held at the University of Sheffield. The annual conference covers all aspects of semiconductor research, from crystal growth, through investigations of the physics of semiconductor structures to realization of semiconductor devices and their application in emerging technologies. The 2012 conference featured over 150 presentations, including plenary sessions on interband cascade lasers for the 3-6 µm spectral band, efficient single photon sources based on InAs quantum dots embedded in GaAs photonic nanowires, nitride-based quantum dot visible lasers and single photon sources, and engineering of organic light-emitting diodes. The seven papers collected here highlight current research advances, taken from across the scope of the conference. The papers feature growth of novel nitride-antimonide material systems for mid-infrared sources and detectors, use of semiconductor nanostructures for charge-based memory and visible lasers, optimization of device structures either to reduce losses in solar cells or achieve low noise amplification in transistors, design considerations for surface-emitting lasers incorporating photonic crystals and an assessment of laser power convertors for power transfer. The editors of this special issue and the conference

  2. Absorption Features in Soil Spectra Assessment.

    PubMed

    Vašát, Radim; Kodešová, Radka; Borůvka, Luboš; Jakšík, Ondřej; Klement, Aleš; Drábek, Ondřej

    2015-12-01

    From a wide range of techniques appropriate to relate spectra measurements with soil properties, partial least squares (PLS) regression and support vector machines (SVM) are most commonly used. This is due to their predictive power and the availability of software tools. Both represent exclusively statistically based approaches and, as such, benefit from multiple responses of soil material in the spectrum. However, physical-based approaches that focus only on a single spectral feature, such as simple linear regression using selected continuum-removed spectra values as a predictor variable, often provide accurate estimates. Furthermore, if this approach extends to multiple cases by taking into account three basic absorption feature parameters (area, width, and depth) of all occurring features as predictors and subjecting them to best subset selection, one can achieve even higher prediction accuracy compared with PLS regression. Here, we attempt to further extend this approach by adding two additional absorption feature parameters (left and right side area), as they can be important diagnostic markers, too. As a result, we achieved higher prediction accuracy compared with PLS regression and SVM for exchangeable soil pH, slightly higher or comparable for dithionite-citrate and ammonium oxalate extractable Fe and Mn forms, but slightly worse for oxidizable carbon content. Therefore, we suggest incorporating the multiple linear regression approach based on absorption feature parameters into existing working practices. PMID:26555184

  3. Absorption Features in Soil Spectra Assessment.

    PubMed

    Vašát, Radim; Kodešová, Radka; Borůvka, Luboš; Jakšík, Ondřej; Klement, Aleš; Drábek, Ondřej

    2015-12-01

    From a wide range of techniques appropriate to relate spectra measurements with soil properties, partial least squares (PLS) regression and support vector machines (SVM) are most commonly used. This is due to their predictive power and the availability of software tools. Both represent exclusively statistically based approaches and, as such, benefit from multiple responses of soil material in the spectrum. However, physical-based approaches that focus only on a single spectral feature, such as simple linear regression using selected continuum-removed spectra values as a predictor variable, often provide accurate estimates. Furthermore, if this approach extends to multiple cases by taking into account three basic absorption feature parameters (area, width, and depth) of all occurring features as predictors and subjecting them to best subset selection, one can achieve even higher prediction accuracy compared with PLS regression. Here, we attempt to further extend this approach by adding two additional absorption feature parameters (left and right side area), as they can be important diagnostic markers, too. As a result, we achieved higher prediction accuracy compared with PLS regression and SVM for exchangeable soil pH, slightly higher or comparable for dithionite-citrate and ammonium oxalate extractable Fe and Mn forms, but slightly worse for oxidizable carbon content. Therefore, we suggest incorporating the multiple linear regression approach based on absorption feature parameters into existing working practices.

  4. Absorption Features in Spectra of Magnetized Neutron Stars

    SciTech Connect

    Suleimanov, V.; Hambaryan, V.; Neuhaeuser, R.; Potekhin, A. Y.; Pavlov, G. G.; Adelsberg, M. van; Werner, K.

    2011-09-21

    The X-ray spectra of some magnetized isolated neutron stars (NSs) show absorption features with equivalent widths (EWs) of 50-200 eV, whose nature is not yet well known.To explain the prominent absorption features in the soft X-ray spectra of the highly magnetized (B{approx}10{sup 14} G) X-ray dim isolated NSs (XDINSs), we theoretically investigate different NS local surface models, including naked condensed iron surfaces and partially ionized hydrogen model atmospheres, with semi-infinite and thin atmospheres above the condensed surface. We also developed a code for computing light curves and integral emergent spectra of magnetized neutron stars with various temperature and magnetic field distributions over the NS surface. We compare the general properties of the computed and observed light curves and integral spectra for XDINS RBS 1223 and conclude that the observations can be explained by a thin hydrogen atmosphere above the condensed iron surface, while the presence of a strong toroidal magnetic field component on the XDINS surface is unlikely.We suggest that the harmonically spaced absorption features in the soft X-ray spectrum of the central compact object (CCO) 1E 1207.4-5209 (hereafter 1E 1207) correspond to peaks in the energy dependence of the free-free opacity in a quantizing magnetic field, known as quantum oscillations. To explore observable properties of these quantum oscillations, we calculate models of hydrogen NS atmospheres with B{approx}10{sup 10}-10{sup 11} G(i.e., electron cyclotron energy E{sub c,e}{approx}0.1-1 keV) and T{sub eff} = 1-3 MK. Such conditions are thought to be typical for 1E 1207. We show that observable features at the electron cyclotron harmonics with EWs {approx_equal}100-200 eV can arise due to these quantum oscillations.

  5. Random Photon Absorption Model Elucidates How Early Gain Control in Fly Photoreceptors Arises from Quantal Sampling.

    PubMed

    Song, Zhuoyi; Zhou, Yu; Juusola, Mikko

    2016-01-01

    Many diurnal photoreceptors encode vast real-world light changes effectively, but how this performance originates from photon sampling is unclear. A 4-module biophysically-realistic fly photoreceptor model, in which information capture is limited by the number of its sampling units (microvilli) and their photon-hit recovery time (refractoriness), can accurately simulate real recordings and their information content. However, sublinear summation in quantum bump production (quantum-gain-nonlinearity) may also cause adaptation by reducing the bump/photon gain when multiple photons hit the same microvillus simultaneously. Here, we use a Random Photon Absorption Model (RandPAM), which is the 1st module of the 4-module fly photoreceptor model, to quantify the contribution of quantum-gain-nonlinearity in light adaptation. We show how quantum-gain-nonlinearity already results from photon sampling alone. In the extreme case, when two or more simultaneous photon-hits reduce to a single sublinear value, quantum-gain-nonlinearity is preset before the phototransduction reactions adapt the quantum bump waveform. However, the contribution of quantum-gain-nonlinearity in light adaptation depends upon the likelihood of multi-photon-hits, which is strictly determined by the number of microvilli and light intensity. Specifically, its contribution to light-adaptation is marginal (≤ 1%) in fly photoreceptors with many thousands of microvilli, because the probability of simultaneous multi-photon-hits on any one microvillus is low even during daylight conditions. However, in cells with fewer sampling units, the impact of quantum-gain-nonlinearity increases with brightening light. PMID:27445779

  6. Random Photon Absorption Model Elucidates How Early Gain Control in Fly Photoreceptors Arises from Quantal Sampling

    PubMed Central

    Song, Zhuoyi; Zhou, Yu; Juusola, Mikko

    2016-01-01

    Many diurnal photoreceptors encode vast real-world light changes effectively, but how this performance originates from photon sampling is unclear. A 4-module biophysically-realistic fly photoreceptor model, in which information capture is limited by the number of its sampling units (microvilli) and their photon-hit recovery time (refractoriness), can accurately simulate real recordings and their information content. However, sublinear summation in quantum bump production (quantum-gain-nonlinearity) may also cause adaptation by reducing the bump/photon gain when multiple photons hit the same microvillus simultaneously. Here, we use a Random Photon Absorption Model (RandPAM), which is the 1st module of the 4-module fly photoreceptor model, to quantify the contribution of quantum-gain-nonlinearity in light adaptation. We show how quantum-gain-nonlinearity already results from photon sampling alone. In the extreme case, when two or more simultaneous photon-hits reduce to a single sublinear value, quantum-gain-nonlinearity is preset before the phototransduction reactions adapt the quantum bump waveform. However, the contribution of quantum-gain-nonlinearity in light adaptation depends upon the likelihood of multi-photon-hits, which is strictly determined by the number of microvilli and light intensity. Specifically, its contribution to light-adaptation is marginal (≤ 1%) in fly photoreceptors with many thousands of microvilli, because the probability of simultaneous multi-photon-hits on any one microvillus is low even during daylight conditions. However, in cells with fewer sampling units, the impact of quantum-gain-nonlinearity increases with brightening light. PMID:27445779

  7. Wavelength calibration of imaging spectrometer using atmospheric absorption features

    NASA Astrophysics Data System (ADS)

    Zhou, Jiankang; Chen, Yuheng; Chen, Xinhua; Ji, Yiqun; Shen, Weimin

    2012-11-01

    Imaging spectrometer is a promising remote sensing instrument widely used in many filed, such as hazard forecasting, environmental monitoring and so on. The reliability of the spectral data is the determination to the scientific communities. The wavelength position at the focal plane of the imaging spectrometer will change as the pressure and temperature vary, or the mechanical vibration. It is difficult for the onboard calibration instrument itself to keep the spectrum reference accuracy and it also occupies weight and the volume of the remote sensing platform. Because the spectral images suffer from the atmospheric effects, the carbon oxide, water vapor, oxygen and solar Fraunhofer line, the onboard wavelength calibration can be processed by the spectral images themselves. In this paper, wavelength calibration is based on the modeled and measured atmospheric absorption spectra. The modeled spectra constructed by the atmospheric radiative transfer code. The spectral angle is used to determine the best spectral similarity between the modeled spectra and measured spectra and estimates the wavelength position. The smile shape can be obtained when the matching process across all columns of the data. The present method is successful applied on the Hyperion data. The value of the wavelength shift is obtained by shape matching of oxygen absorption feature and the characteristics are comparable to that of the prelaunch measurements.

  8. The origin of blueshifted absorption features in the X-ray spectrum of PG 1211+143: outflow or disc

    NASA Astrophysics Data System (ADS)

    Gallo, L. C.; Fabian, A. C.

    2013-07-01

    In some radio-quiet active galactic nuclei (AGN), high-energy absorption features in the X-ray spectra have been interpreted as ultrafast outflows (UFOs) - highly ionized material (e.g. Fe XXV and Fe XXVI) ejected at mildly relativistic velocities. In some cases, these outflows can carry energy in excess of the binding energy of the host galaxy. Needless to say, these features demand our attention as they are strong signatures of AGN feedback and will influence galaxy evolution. For the same reason, alternative models need to be discussed and refuted or confirmed. Gallo and Fabian proposed that some of these features could arise from resonance absorption of the reflected spectrum in a layer of ionized material located above and corotating with the accretion disc. Therefore, the absorbing medium would be subjected to similar blurring effects as seen in the disc. A priori, the existence of such plasma above the disc is as plausible as a fast wind. In this work, we highlight the ambiguity by demonstrating that the absorption model can describe the ˜7.6 keV absorption feature (and possibly other features) in the quasar PG 1211+143, an AGN that is often described as a classic example of a UFO. In this model, the 2-10 keV spectrum would be largely reflection dominated (as opposed to power law dominated in the wind models) and the resonance absorption would be originating in a layer between about 6 and 60 gravitational radii. The studies of such features constitute a cornerstone for future X-ray observatories like Astro-H and Athena+. Should our model prove correct, or at least important in some cases, then absorption will provide another diagnostic tool with which to probe the inner accretion flow with future missions.

  9. High-Velocity Absorption Features in FUSE Spectra of Eta Carinae

    NASA Astrophysics Data System (ADS)

    Sonneborn, G.; Iping, R. C.; Gull, T. R.; Vieira, G.

    2002-12-01

    Numerous broad (200 to 1000 km/sec) features in the FUSE spectrum (905-1187 A) of eta Carinae are identified as absorption by a forest of high-velocity narrow lines formed in the expanding circumstellar envelope. These features were previously thought to be P-Cygni lines arising in the wind of the central star. The features span a heliocentric velocity range of -140 to -580 km/sec and are seen prominently in low-ionization ground-state transitions (e.g. N I 1134-35, Fe II 1145-42, 1133, 1127-22, P II 1153, C I 1158) in addition to C III] 1176 A. The high-velocity components of the FUSE transitions have depths about 50% below the continuum. The identifications are consistent with the complex velocity structures seen in ground- and excited-state transitions of Mg I, Mg II, Fe II, V II, etc observed in STIS/E230H spectra (see accompanying posters by Gull, Vieira, and Danks). The origin of other broad features of similar width and depth in the FUSE spectrum, but without low-velocity ISM absorption, are unidentified. However, they are suspected of being absorption of singly-ionized iron-peak elements (e.g. Fe II, V II, Cr II) out of excited levels 1,000 to 20,000 cmE-1 above the ground state. The high-velocity features seen in Fe II 1145 are also present in Fe II 1608 (STIS/E140M), but are highly saturated in the latter. Since these transitions have nearly identical log (flambda) (1.998 vs. 2.080), the differences in the profiles are attributable to the different aperture sizes used (30x30 arcsec for FUSE, 0.2x0.2 arcsec for STIS/E140M). The high-velocity gas appears to be very patchy or has a small covering factor near the central star. Eta Carinae has been observed several times by FUSE over the past three years. The FUSE flux levels and spectral features in eta Car are essentially unchanged over the 2000 March to June 2002 period, establishing a baseline far-UV spectrum in advance of the predicted spectroscopic miniumum in 2003.

  10. High-Velocity Absorption Features in FUSE Spectra of Eta Carinae

    NASA Technical Reports Server (NTRS)

    Sonneborn, G.; Iping, R. C.; Gull, T. R.; Vieira, G.

    2003-01-01

    Numerous broad (200 to 1000 km/sec) features in the FUSE spectrum (905-1187 A) of eta Carinae are identified as absorption by a forest of high-velocity narrow lines formed in the expanding circumstellar envelope. These features were previously thought to be P-Cygni lines arising in the wind of the central star. The features span a heliocentric velocity range of -140 to -580 km/sec and are seen prominently in low-ionization ground-state transitions (e.g. N I 1134-35, Fe II 1145-42, 1133, 1127- 22, P II 1153, C I 1158) in addition to C III] 1176 A. The high-velocity components of the FUSE transitions have depths about 50% below the continuum. The identifications are consistent with the complex velocity structures seen in ground- and excited-state transitions of Mg I, Mg 11, Fe II, V II, etc observed in STIS/E230H spectra. The origin of other broad features of similar width and depth in the FUSE spectrum, but without low-velocity ISM absorption, are unidentified. However, they are suspected of being absorption of singly-ionized iron-peak elements (e.g. Fe II, V II, Cr II) out of excited levels 1,000 to 20,000 cmE-l above the ground state. The high-velocity features seen in Fe II 1145 are also present in Fe II 1608 (STIS/E140M), but are highly saturated in the latter. Since these transitions have nearly identical log (flambda) (1.998 vs. 2.080), the differences in the profiles are attributable to the different aperture sizes used (30 x 30 arcsec for FUSE, 0.2 x 0.2 arcsec for STIS/E140M). The high-velocity gas appears to be very patchy or has a small covering factor near the central star. Eta Carinae has been observed several times by FUSE over the past three years. The FUSE flux levels and spectral features in eta Car are essentially unchanged over the 2000 March to June 2002 period, establishing a baseline far-UV spectrum in advance of the predicted spectroscopic minimum in 2003.

  11. On the nature of absorption features toward nearby stars

    NASA Astrophysics Data System (ADS)

    Kohl, S.; Czesla, S.; Schmitt, J. H. M. M.

    2016-06-01

    Context. Diffuse interstellar absorption bands (DIBs) of largely unknown chemical origin are regularly observed primarily in distant early-type stars. More recently, detections in nearby late-type stars have also been claimed. These stars' spectra are dominated by stellar absorption lines. Specifically, strong interstellar atomic and DIB absorption has been reported in τ Boo. Aims: We test these claims by studying the strength of interstellar absorption in high-resolution TIGRE spectra of the nearby stars τ Boo, HD 33608, and α CrB. Methods: We focus our analysis on a strong DIB located at 5780.61 Å and on the absorption of interstellar Na. First, we carry out a differential analysis by comparing the spectra of the highly similar F-stars, τ Boo and HD 33608, whose light, however, samples different lines of sight. To obtain absolute values for the DIB absorption, we compare the observed spectra of τ Boo, HD 33608, and α CrB to PHOENIX models and carry out basic spectral modeling based on Voigt line profiles. Results: The intercomparison between τ Boo and HD 33608 reveals that the difference in the line depth is 6.85 ± 1.48 mÅ at the DIB location which is, however, unlikely to be caused by DIB absorption. The comparison between PHOENIX models and observed spectra yields an upper limit of 34.0 ± 0.3 mÅ for any additional interstellar absorption in τ Boo; similar results are obtained for HD 33608 and α CrB. For all objects we derive unrealistically large values for the radial velocity of any presumed interstellar clouds. In τ Boo we find Na D absorption with an equivalent width of 0.65 ± 0.07 mÅ and 2.3 ± 0.1 mÅ in the D2 and D1 lines. For the other Na, absorption of the same magnitude could only be detected in the D2 line. Our comparisons between model and data show that the interstellar absorption toward τ Boo is not abnormally high. Conclusions: We find no significant DIB absorption in any of our target stars. Any differences between modeled and

  12. Empathic Features and Absorption in Fantasy Role-Playing.

    PubMed

    Rivers, Anissa; Wickramasekera, Ian E; Pekala, Ronald J; Rivers, Jennifer A

    2016-01-01

    This study examined the levels of empathy and absorption of individuals who regularly play fantasy and science fiction role-playing games. A hypothesis was developed that higher levels of empathy would be found in individuals who fantasy role-play based upon previous research in hypnosis such as J. R. Hilgard's (1970) imaginative involvement hypothesis, research into the "fantasy prone" personality type (Wilson & Barber, 1981), and the empathic involvement hypothesis (Wickramasekera II & Szlyk, 2003). The participants in the current study were 127 fantasy role-players who volunteered and completed the Davis Interpersonal Reactivity Index (empathy) and the Tellegen Absorption Scale (absorption). The results demonstrated that those who play fantasy role-playing games scored significantly higher than the comparison group on the IRI scale of empathy, confirming the hypothesis that fantasy role-players report experiencing higher levels of empathic involvement with others. Correlational analysis between the measures demonstrated a significant positive correlation between empathy and absorption (r = .43, p < .001). These results collectively suggest that fantasy role-players have a uniquely empathically-imaginative style. The results also confirm and extend previous findings on the relationship between empathy and absorption as predicted by the Empathic Involvement Hypothesis (Wickramasekera II & Szlyk, 2003).

  13. Modelling of the X-ray broad absorption features in Narrow-Line Seyfert 1s

    NASA Astrophysics Data System (ADS)

    Porquet, Delphine; Mouchet, Martine; Dumont Anne-Marie

    2000-09-01

    We investigate the origin of the broad absorption features detected near 1-1.4 keV in several Narrow-Line Seyfert 1 galaxies, by modelling the absorbing medium with various physical parameters, using the ionization code PEGAS. The observed properties of the X-ray absorption features can be reproduced by taking into account the peculiar soft X-ray excess which is well fitted by a blackbody plus an underlying power law. We equally stress that the emission coming from the absorbing medium (related to the covering factor) has a strong influence on the resulting X-ray spectrum, in particular on the apparent position and depth of the absorption features. A non-solar iron abundance may be required to explain the observed deep absorption. We also investigate the influence of an additional collisional ionization process ("hybrid case") on the predicted absorption features.

  14. External Cavity Quantum Cascade Laser for Quartz Tuning Fork Photoacoustic Spectroscopy of Broad Absorption Features

    SciTech Connect

    Phillips, Mark C.; Myers, Tanya L.; Wojcik, Michael D.; Cannon, Bret D.

    2007-05-01

    We demonstrate mid-infrared spectroscopy of large molecules with broad absorption features using a tunable external cavity quantum cascade laser. Absorption spectra for two different Freons are measured over the range 1130-1185 cm-1 with 0.2 cm-1 resolution via laser photoacoustic spectroscopy with quartz tuning forks as acoustic transducers. The measured spectra are in excellent agreement with published reference absorption spectra.

  15. Using high spectral resolution spectrophotometry to study broad mineral absorption features on Mars

    NASA Technical Reports Server (NTRS)

    Blaney, D. L.; Crisp, D.

    1993-01-01

    Traditionally telescopic measurements of mineralogic absorption features have been made using relatively low to moderate (R=30-300) spectral resolution. Mineralogic absorption features tend to be broad so high resolution spectroscopy (R greater than 10,000) does not provide significant additional compositional information. Low to moderate resolution spectroscopy allows an observer to obtain data over a wide wavelength range (hundreds to thousands of wavenumbers) compared to the several wavenumber intervals that are collected using high resolution spectrometers. However, spectrophotometry at high resolution has major advantages over lower resolution spectroscopy in situations that are applicable to studies of the Martian surface, i.e., at wavelengths where relatively weak surface absorption features and atmospheric gas absorption features both occur.

  16. Spectral calibration of hyperspectral imagery using atmospheric absorption features.

    PubMed

    Guanter, Luis; Richter, Rudolf; Moreno, José

    2006-04-01

    One of the initial steps in the preprocessing of remote sensing data is the atmospheric correction of the at-sensor radiance images, i.e., radiances recorded at the sensor aperture. Apart from the accuracy in the estimation of the concentrations of the main atmospheric species, the retrieved surface reflectance is also influenced by the spectral calibration of the sensor, especially in those wavelengths mostly affected by gaseous absorptions. In particular, errors in the surface reflectance appear when a systematic shift in the nominal channel positions occurs. A method to assess the spectral calibration of hyperspectral imaging spectrometers from the acquired imagery is presented in this paper. The fundamental basis of the method is the calculation of the value of the spectral shift that minimizes the error in the estimates of surface reflectance. This is performed by an optimization procedure that minimizes the deviation between a surface reflectance spectrum and a smoothed one resulting from the application of a low-pass filter. A sensitivity analysis was performed using synthetic data generated with the MODTRAN4 radiative transfer code for several values of the spectral shift and the water vapor column content. The error detected in the retrieval is less than +/- 0.2 nm for spectral shifts smaller than 2 nm, and less than +/- 1.0 nm for extreme spectral shifts of 5 nm. A low sensitivity to uncertainties in the estimation of water vapor content was found, which reinforces the robustness of the algorithm. The method was successfully applied to data acquired by different hyperspectral sensors. PMID:16608005

  17. Phyllosilicate absorption features in main-belt and outer-belt asteroid reflectance spectra.

    PubMed

    Vilas, F; Gaffey, M J

    1989-11-10

    Absorption features having depths up to 5% are identified in high-quality, high-resolution reflectance spectra of 16 dark asteroids in the main belt and in the Cybele and Hilda groups. Analogs among the CM2 carbonaceous chondrite meteorites exist for some of these asteroids, suggesting that these absorptions are due to iron oxides in phyllosilicates formed on the asteroidal surfaces by aqueous alteration processes. Spectra of ten additional asteroids, located beyond the outer edge of the main belt, show no discernible absorption features, suggesting that aqueous alteration did not always operate at these heliocentric distances.

  18. ARISE antenna

    NASA Astrophysics Data System (ADS)

    Chmielewski, Arthur B.; Noca, Muriel; Ulvestad, James

    2000-03-01

    Supermassive black holes are among the most spectacular objects in the Universe, and are laboratories for physics in extreme conditions. Understanding the physics of massive black holes and related phenomena is a primary goal of the ARISE mission. The scientific goals of the mission are described in detail on the ARISE web site http://arise.ipl.nasa.gov and in the ARISE Science Goals document. The following paper, as the title suggests, is not intended to be a comprehensive description of ARISE, but deals only with one aspect of the ARISE mission-the inflatable antenna which is the key element of the ARISE spacecraft. This spacecraft,due to the extensive reliance on inflatables, may be considered as the first generation Gossamer spacecraft

  19. Spatially Resolved HCN Absorption Features in the Circumnuclear Region of NGC 1052

    NASA Astrophysics Data System (ADS)

    Sawada-Satoh, Satoko; Roh, Duk-Gyoo; Oh, Se-Jin; Lee, Sang-Sung; Byun, Do-Young; Kameno, Seiji; Yeom, Jae-Hwan; Jung, Dong-Kyu; Kim, Hyo-Ryoung; Hwang, Ju-Yeon

    2016-10-01

    We present the first VLBI detection of HCN molecular absorption in the nearby active galactic nucleus NGC 1052. Utilizing the 1 mas resolution achieved by the Korean VLBI Network, we have spatially resolved the HCN absorption against a double-sided nuclear jet structure. Two velocity features of HCN absorption are detected significantly at the radial velocity of 1656 and 1719 km s‑1, redshifted by 149 and 212 km s‑1 with respect to the systemic velocity of the galaxy. The column density of the HCN molecule is estimated to be 1015–1016 cm‑2, assuming an excitation temperature of 100–230 K. The absorption features show high optical depth localized on the receding jet side, where the free–free absorption occurred due to the circumnuclear torus. The size of the foreground absorbing molecular gas is estimated to be on approximately one-parsec scales, which agrees well with the approximate size of the circumnuclear torus. HCN absorbing gas is likely to be several clumps smaller than 0.1 pc inside the circumnuclear torus. The redshifted velocities of the HCN absorption features imply that HCN absorbing gas traces ongoing infall motion inside the circumnuclear torus onto the central engine.

  20. Plant phenolics and absorption features in vegetation reflectance spectra near 1.66 μm

    NASA Astrophysics Data System (ADS)

    Kokaly, Raymond F.; Skidmore, Andrew K.

    2015-12-01

    Past laboratory and field studies have quantified phenolic substances in vegetative matter from reflectance measurements for understanding plant response to herbivores and insect predation. Past remote sensing studies on phenolics have evaluated crop quality and vegetation patterns caused by bedrock geology and associated variations in soil geochemistry. We examined spectra of pure phenolic compounds, common plant biochemical constituents, dry leaves, fresh leaves, and plant canopies for direct evidence of absorption features attributable to plant phenolics. Using spectral feature analysis with continuum removal, we observed that a narrow feature at 1.66 μm is persistent in spectra of manzanita, sumac, red maple, sugar maple, tea, and other species. This feature was consistent with absorption caused by aromatic Csbnd H bonds in the chemical structure of phenolic compounds and non-hydroxylated aromatics. Because of overlapping absorption by water, the feature was weaker in fresh leaf and canopy spectra compared to dry leaf measurements. Simple linear regressions of feature depth and feature area with polyphenol concentration in tea resulted in high correlations and low errors (% phenol by dry weight) at the dry leaf (r2 = 0.95, RMSE = 1.0%, n = 56), fresh leaf (r2 = 0.79, RMSE = 2.1%, n = 56), and canopy (r2 = 0.78, RMSE = 1.0%, n = 13) levels of measurement. Spectra of leaves, needles, and canopies of big sagebrush and evergreens exhibited a weak absorption feature centered near 1.63 μm, short ward of the phenolic compounds, possibly consistent with terpenes. This study demonstrates that subtle variation in vegetation spectra in the shortwave infrared can directly indicate biochemical constituents and be used to quantify them. Phenolics are of lesser abundance compared to the major plant constituents but, nonetheless, have important plant functions and ecological significance. Additional research is needed to advance our understanding of the spectral influences

  1. Where’s the Noise? Key Features of Spontaneous Activity and Neural Variability Arise through Learning in a Deterministic Network

    PubMed Central

    Hartmann, Christoph; Lazar, Andreea; Nessler, Bernhard; Triesch, Jochen

    2015-01-01

    Even in the absence of sensory stimulation the brain is spontaneously active. This background “noise” seems to be the dominant cause of the notoriously high trial-to-trial variability of neural recordings. Recent experimental observations have extended our knowledge of trial-to-trial variability and spontaneous activity in several directions: 1. Trial-to-trial variability systematically decreases following the onset of a sensory stimulus or the start of a motor act. 2. Spontaneous activity states in sensory cortex outline the region of evoked sensory responses. 3. Across development, spontaneous activity aligns itself with typical evoked activity patterns. 4. The spontaneous brain activity prior to the presentation of an ambiguous stimulus predicts how the stimulus will be interpreted. At present it is unclear how these observations relate to each other and how they arise in cortical circuits. Here we demonstrate that all of these phenomena can be accounted for by a deterministic self-organizing recurrent neural network model (SORN), which learns a predictive model of its sensory environment. The SORN comprises recurrently coupled populations of excitatory and inhibitory threshold units and learns via a combination of spike-timing dependent plasticity (STDP) and homeostatic plasticity mechanisms. Similar to balanced network architectures, units in the network show irregular activity and variable responses to inputs. Additionally, however, the SORN exhibits sequence learning abilities matching recent findings from visual cortex and the network’s spontaneous activity reproduces the experimental findings mentioned above. Intriguingly, the network’s behaviour is reminiscent of sampling-based probabilistic inference, suggesting that correlates of sampling-based inference can develop from the interaction of STDP and homeostasis in deterministic networks. We conclude that key observations on spontaneous brain activity and the variability of neural responses can be

  2. Where's the Noise? Key Features of Spontaneous Activity and Neural Variability Arise through Learning in a Deterministic Network.

    PubMed

    Hartmann, Christoph; Lazar, Andreea; Nessler, Bernhard; Triesch, Jochen

    2015-12-01

    Even in the absence of sensory stimulation the brain is spontaneously active. This background "noise" seems to be the dominant cause of the notoriously high trial-to-trial variability of neural recordings. Recent experimental observations have extended our knowledge of trial-to-trial variability and spontaneous activity in several directions: 1. Trial-to-trial variability systematically decreases following the onset of a sensory stimulus or the start of a motor act. 2. Spontaneous activity states in sensory cortex outline the region of evoked sensory responses. 3. Across development, spontaneous activity aligns itself with typical evoked activity patterns. 4. The spontaneous brain activity prior to the presentation of an ambiguous stimulus predicts how the stimulus will be interpreted. At present it is unclear how these observations relate to each other and how they arise in cortical circuits. Here we demonstrate that all of these phenomena can be accounted for by a deterministic self-organizing recurrent neural network model (SORN), which learns a predictive model of its sensory environment. The SORN comprises recurrently coupled populations of excitatory and inhibitory threshold units and learns via a combination of spike-timing dependent plasticity (STDP) and homeostatic plasticity mechanisms. Similar to balanced network architectures, units in the network show irregular activity and variable responses to inputs. Additionally, however, the SORN exhibits sequence learning abilities matching recent findings from visual cortex and the network's spontaneous activity reproduces the experimental findings mentioned above. Intriguingly, the network's behaviour is reminiscent of sampling-based probabilistic inference, suggesting that correlates of sampling-based inference can develop from the interaction of STDP and homeostasis in deterministic networks. We conclude that key observations on spontaneous brain activity and the variability of neural responses can be

  3. Where's the Noise? Key Features of Spontaneous Activity and Neural Variability Arise through Learning in a Deterministic Network.

    PubMed

    Hartmann, Christoph; Lazar, Andreea; Nessler, Bernhard; Triesch, Jochen

    2015-12-01

    Even in the absence of sensory stimulation the brain is spontaneously active. This background "noise" seems to be the dominant cause of the notoriously high trial-to-trial variability of neural recordings. Recent experimental observations have extended our knowledge of trial-to-trial variability and spontaneous activity in several directions: 1. Trial-to-trial variability systematically decreases following the onset of a sensory stimulus or the start of a motor act. 2. Spontaneous activity states in sensory cortex outline the region of evoked sensory responses. 3. Across development, spontaneous activity aligns itself with typical evoked activity patterns. 4. The spontaneous brain activity prior to the presentation of an ambiguous stimulus predicts how the stimulus will be interpreted. At present it is unclear how these observations relate to each other and how they arise in cortical circuits. Here we demonstrate that all of these phenomena can be accounted for by a deterministic self-organizing recurrent neural network model (SORN), which learns a predictive model of its sensory environment. The SORN comprises recurrently coupled populations of excitatory and inhibitory threshold units and learns via a combination of spike-timing dependent plasticity (STDP) and homeostatic plasticity mechanisms. Similar to balanced network architectures, units in the network show irregular activity and variable responses to inputs. Additionally, however, the SORN exhibits sequence learning abilities matching recent findings from visual cortex and the network's spontaneous activity reproduces the experimental findings mentioned above. Intriguingly, the network's behaviour is reminiscent of sampling-based probabilistic inference, suggesting that correlates of sampling-based inference can develop from the interaction of STDP and homeostasis in deterministic networks. We conclude that key observations on spontaneous brain activity and the variability of neural responses can be

  4. Measurement of Broad Absorption Features Using a Tunable External Cavity Quantum Cascade Laser

    SciTech Connect

    Phillips, Mark C.; Myers, Tanya L.; Wojcik, Michael D.; Cannon, Bret D.; Taubman, Matthew S.; Scott, David C.

    2007-09-25

    We demonstrate the use of a tunable external cavity quantum cascade laser system for measurement of broad absorption features in the mid-infrared spectral region. The thermoelectrically cooled external cavity laser was tuned over a 65 cm-1 range centered at 8.7 microns using stepper motor control. Pulsing the laser at a high duty cycle provided 3-5 mW average output power over the tuning range, and enabled phase-sensitive detection of amplitude-modulated signals. We used the laser system to measure the absorption spectra of Freon-125 using a Herriott cell. In addition, the absorption spectrum of water in the laboratory air was measured. The measurements showed excellent agreement with reference spectra, in both wavelength and amplitude. The measured scan resolution of 0.14 cm-1 is suitable for measurement of the absorption features of complex molecules as well as simple molecules with atmospherically broadened lines. We discuss the limits to the scan resolution due to effects of spectral chirp and mode-hops during pulsed operation.

  5. Measurement of broad absorption features using a tunable external cavity quantum cascade laser

    NASA Astrophysics Data System (ADS)

    Phillips, Mark C.; Myers, Tanya L.; Wojcik, Michael D.; Cannon, Bret D.; Taubman, Matthew S.; Scott, David C.

    2007-09-01

    We demonstrate the use of a tunable external cavity quantum cascade laser system for measurement of broad absorption features in the mid-infrared spectral region. The thermoelectrically cooled external cavity laser was tuned over a 65 cm -1range centered at 8.7 microns using stepper motor control. Pulsing the laser at a high duty cycle provided 2-4.5 mW average output power over the tuning range, and enabled phase-sensitive detection of amplitude-modulated signals. We used the laser system to measure the absorption spectra of Freon-125 using a Herriott cell. In addition, the absorption spectrum of water in the laboratory air was measured. The measurements showed excellent agreement with reference spectra, in both wavelength and amplitude. The measured scan resolution of 0.14 cm -1 is suitable for measurement of the absorption features of complex molecules as well as simple molecules with atmospherically broadened lines. We discuss the limits to the scan resolution due to effects of spectral chirp and mode-hops during pulsed operation.

  6. Investigations on the 1.7 micron residual absorption feature in the vegetation reflection spectrum

    NASA Technical Reports Server (NTRS)

    Verdebout, J.; Jacquemoud, S.; Andreoli, G.; Hosgood, B.; Sieber, A.

    1993-01-01

    The detection and interpretation of the weak absorption features associated with the biochemical components of vegetation is of great potential interest to a variety of applications ranging from classification to global change studies. This recent subject is also challenging because the spectral signature of the biochemicals is only detectable as a small distortion of the infrared spectrum which is mainly governed by water. Furthermore, the interpretation is complicated by complexity of the molecules (lignin, cellulose, starch, proteins) which contain a large number of different and common chemical bonds. In this paper, we present investigations on the absorption feature centered at 1.7 micron; these were conducted both on AVIRIS data and laboratory reflectance spectra of leaves.

  7. Plant phenolics and absorption features in vegetation reflectance spectra near 1.66 μm

    USGS Publications Warehouse

    Kokaly, Raymond F.; Skidmore, Andrew K

    2015-01-01

    Past laboratory and field studies have quantified phenolic substances in vegetative matter from reflectance measurements for understanding plant response to herbivores and insect predation. Past remote sensing studies on phenolics have evaluated crop quality and vegetation patterns caused by bedrock geology and associated variations in soil geochemistry. We examined spectra of pure phenolic compounds, common plant biochemical constituents, dry leaves, fresh leaves, and plant canopies for direct evidence of absorption features attributable to plant phenolics. Using spectral feature analysis with continuum removal, we observed that a narrow feature at 1.66 μm is persistent in spectra of manzanita, sumac, red maple, sugar maple, tea, and other species. This feature was consistent with absorption caused by aromatic C-H bonds in the chemical structure of phenolic compounds and non-hydroxylated aromatics. Because of overlapping absorption by water, the feature was weaker in fresh leaf and canopy spectra compared to dry leaf measurements. Simple linear regressions of feature depth and feature area with polyphenol concentration in tea resulted in high correlations and low errors (% phenol by dry weight) at the dry leaf (r2 = 0.95, RMSE = 1.0%, n = 56), fresh leaf (r2 = 0.79, RMSE = 2.1%, n = 56), and canopy (r2 = 0.78, RMSE = 1.0%, n = 13) levels of measurement. Spectra of leaves, needles, and canopies of big sagebrush and evergreens exhibited a weak absorption feature centered near 1.63 μm, short ward of the phenolic compounds, possibly consistent with terpenes. This study demonstrates that subtle variation in vegetation spectra in the shortwave infrared can directly indicate biochemical constituents and be used to quantify them. Phenolics are of lesser abundance compared to the major plant constituents but, nonetheless, have important plant functions and ecological significance. Additional research is needed to advance our understanding of the

  8. Absorption features in the 5-8 micron spectra of protostars

    NASA Technical Reports Server (NTRS)

    Tielens, A. G. G. M.; Allamandola, L. J.; Bregman, J.; Goebel, J.; Witteborn, F. C.; Dhendecourt, L. B.

    1984-01-01

    High signal-to-noise ratio spectra in the range of 5-8 microns of four sources embedded in molecular clouds are examined using low-temperature laboratory measurements of the 5-8-micron spectra of simple molecules and their mixtures. The absorption, apparent in all four sources, is characterized by highly distinct features ranging from two relatively narrow bands at 6.0 and 6.8 microns in W33A to a broad, shallow, and partially structured feature extending from 5.2 to 7.8 microns in Mon R2-IRS2, BN, and NGC2264. The first feature (W33A) is explained by the OH bending mode in H2O and the CH deformation modes in saturated hydrocarbons; while the second feature (Mon R2-IRS2-type) is explained by the presence of a mixture of saturated and unsaturated hydrocarbons possibly containing strongly electronegative groups.

  9. Iron K Features in the Quasar E 1821+643: Evidence for Gravitationally Redshifted Absorption?

    NASA Technical Reports Server (NTRS)

    Yaqoob, Tahir; Serlemitsos, Peter

    2005-01-01

    We report a Chandra high-energy grating detection of a narrow, redshifted absorption line superimposed on the red wing of a broad Fe K line in the z = 0.297 quasar E 1821+643. The absorption line is detected at a confidence level, estimated by two different methods, in the range approx. 2 - 3 sigma. Although the detection significance is not high enough to exclude a non-astrophysical origin, accounting for the absorption feature when modeling the X-ray spectrum implies that the Fe-K emission line is broad, and consistent with an origin in a relativistic accretion disk. Ignoring the apparent absorption feature leads to the conclusion that the Fe-K emission line is narrower, and also affects the inferred peak energy of the line (and hence the inferred ionization state of Fe). If the absorption line (at approx. 6.2 keV in the quasar frame) is real, we argue that it could be due to gravitationally redshifted Fe XXV or Fe XXVI resonance absorption within approx. 10 - 20 gravitational radii of the putative central black hole. The absorption line is not detected in earlier ASCA and Chandra low-energy grating observations, but the absorption line is not unequivocally ruled out by these data. The Chandra high-energy grating Fe-K emission line is consistent with an origin predominantly in Fe I-XVII or so. In an ASCA observation eight years earlier, the Fe-K line peaked at approx. 6.6 keV, closer to the energies of He-like Fe triplet lines. Further, in a Chandra low-energy grating observation the Fe-K line profile was double-peaked, one peak corresponding to Fe I-XVII or so, the other peak to Fe XXVI Ly alpha. Such a wide range in ionization state of Fe is not ruled out by the HEG and ASCA data either, and is suggestive of a complex structure for the line-emitter.

  10. Detection of Variable Gaseous Absorption Features in the Debris Disks Around Young A-type Stars

    NASA Astrophysics Data System (ADS)

    Montgomery, Sharon L.; Welsh, Barry Y.

    2012-10-01

    We present medium resolution (R = 60,000) absorption measurements of the interstellar Ca II K line observed towards five nearby A-type stars (49 Ceti, 5 Vul, ι Cyg, 2 And, and HD 223884) suspected of possessing circumstellar gas debris disks. The stars were observed on a nightly basis during a six night observing run on the 2.1-meter Otto Struve telescope at the McDonald Observatory, Texas. We have detected nightly changes in the absorption strength of the Ca II K line observed near the stellar radial velocity in three of the stars (49 Ceti, i Cyg and HD 223884). Such changes in absorption suggest the presence of a circumstellar (atomic) gas disk around these stars. In addition to the absorption changes in the main Ca II K line profile, we have also observed weak transient absorption features that randomly appear at redshifted velocities in the spectra of 49 Ceti, 5 Vul, and 2 And. These absorption features are most probably associated with the presence of falling evaporated bodies (exo-comets) that liberate evaporating gas on their approach to the central star. This now brings the total number of systems in which exocomet activity has been observed at Ca II or Na I wavelengths on a nightly basis to seven (β Pic, HR 10, HD 85905, β Car, 49 Ceti, 5 Vul, and 2 And), with 2 And exhibiting weaker and less frequent changes. All of the disk systems presently known to exhibit either type of short-term variability in Ca II K line absorption are rapidly rotating A-type stars (V sin i > 120 km s-1). Most exhibit mid-IR excesses, and many of them are very young (< 20 Myr), thus supporting the argument that many of them are transitional objects between Herbig Ae and "Vega-like" A-type stars with more tenuous circumstellar disks. No mid-IR excess (due to the presence of a dust disk) has yet been detected around either 2 And or HD 223884, both of which have been classified as λ Boötis-type stars. This may indicate that the observed changes in gas absorption for these two

  11. Detection of the 2175 Å Dust Feature in Mg II Absorption Systems

    NASA Astrophysics Data System (ADS)

    Malhotra, Sangeeta

    1997-10-01

    The broad absorption bump at 2175 Å due to dust, which is ubiquitous in the Galaxy and is seen in the Magellanic clouds, is also seen in a composite spectrum of Mg II absorbers. The composite absorber spectrum is obtained by taking the geometric mean of 92 quasar spectra after aligning them in the rest frame of 96 absorbers. By aligning the spectra according to absorber redshifts, we reinforce the spectral features of the absorbers and smooth over possible bumps and wiggles in the emission spectra as well as small features in the flat-fielding of the spectra. The width of the observed absorption feature is 200-300 Å (FWHM), or 0.4-0.6 μm-1, and the central wavelength is 2240 Å. These are somewhat different from the central wavelength of 2176 Å and FWHM = 0.8-1.25 μm-1 found in the Galaxy. Simulations show that this discrepancy between the properties of the 2175 Å feature in Mg II absorbers and the Galactic interstellar medium can be mostly explained by the different methods used to measure them.

  12. Absorption features in the x-ray spectrum of an ordinary radio pulsar.

    PubMed

    Kargaltsev, Oleg; Durant, Martin; Misanovic, Zdenka; Pavlov, George G

    2012-08-24

    The vast majority of known nonaccreting neutron stars (NSs) are rotation-powered radio and/or γ-ray pulsars. So far, their multiwavelength spectra have all been described satisfactorily by thermal and nonthermal continuum models, with no spectral lines. Spectral features have, however, been found in a handful of exotic NSs and were thought to be a manifestation of their unique traits. Here, we report the detection of absorption features in the x-ray spectrum of an ordinary rotation-powered radio pulsar, J1740+1000. Our findings bridge the gap between the spectra of pulsars and other, more exotic, NSs, suggesting that the features are more common in the NS spectra than they have been thought so far.

  13. Changes on image texture features of breakfast flakes cereals during water absorption.

    PubMed

    Medina, Wenceslao T; Quevedo, Roberto A; Aguilera, José M

    2013-02-01

    Normally breakfast cereal flakes are consumed by pouring them into a bowl and covering them with fresh or cold milk. During this process the liquid uptake causes changes in the surface and internal matrix of breakfast cereals that influence texture and integrity. Some breakfast cereal as flakes have a translucent structure that could provide information about the solid matrix and air cells and how they change during liquid absorption. The objective of the study was to assess the image texture changes of corn flakes and frosted flakes during water absorption at 5, 15 and 25 °C, employing 11 image feature textures extracted from grey-level co-occurrence matrix and grey-level run length matrix (at three directions) and to relate the fractal dimension (FD) of images with rupture force (RF) reduction during soaking of both flakes at 5 °C. The most relevant result from principal component analysis calculated with a matrix of 54 (soaking times) × 22 (texture features), shows that it was possible to distinguish an isolated group consisting of different soaking times at the same water temperature in each breakfast cereal flakes evaluated, corroborating that superficial liquid imbibition is important during the liquid absorption process when flakes are soaked. Furthermore, standardized FD could be related to RF in the period when samples tend to search for an equilibrium state.

  14. Changes on image texture features of breakfast flakes cereals during water absorption.

    PubMed

    Medina, Wenceslao T; Quevedo, Roberto A; Aguilera, José M

    2013-02-01

    Normally breakfast cereal flakes are consumed by pouring them into a bowl and covering them with fresh or cold milk. During this process the liquid uptake causes changes in the surface and internal matrix of breakfast cereals that influence texture and integrity. Some breakfast cereal as flakes have a translucent structure that could provide information about the solid matrix and air cells and how they change during liquid absorption. The objective of the study was to assess the image texture changes of corn flakes and frosted flakes during water absorption at 5, 15 and 25 °C, employing 11 image feature textures extracted from grey-level co-occurrence matrix and grey-level run length matrix (at three directions) and to relate the fractal dimension (FD) of images with rupture force (RF) reduction during soaking of both flakes at 5 °C. The most relevant result from principal component analysis calculated with a matrix of 54 (soaking times) × 22 (texture features), shows that it was possible to distinguish an isolated group consisting of different soaking times at the same water temperature in each breakfast cereal flakes evaluated, corroborating that superficial liquid imbibition is important during the liquid absorption process when flakes are soaked. Furthermore, standardized FD could be related to RF in the period when samples tend to search for an equilibrium state. PMID:23345324

  15. Ultrafast transient absorption revisited: Phase-flips, spectral fingers, and other dynamical features.

    PubMed

    Cina, Jeffrey A; Kovac, Philip A; Jumper, Chanelle C; Dean, Jacob C; Scholes, Gregory D

    2016-05-01

    We rebuild the theory of ultrafast transient-absorption/transmission spectroscopy starting from the optical response of an individual molecule to incident femtosecond pump and probe pulses. The resulting description makes use of pulse propagators and free molecular evolution operators to arrive at compact expressions for the several contributions to a transient-absorption signal. In this alternative description, which is physically equivalent to the conventional response-function formalism, these signal contributions are conveniently expressed as quantum mechanical overlaps between nuclear wave packets that have undergone different sequences of pulse-driven optical transitions and time-evolution on different electronic potential-energy surfaces. Using this setup in application to a simple, multimode model of the light-harvesting chromophores of PC577, we develop wave-packet pictures of certain generic features of ultrafast transient-absorption signals related to the probed-frequency dependence of vibrational quantum beats. These include a Stokes-shifting node at the time-evolving peak emission frequency, antiphasing between vibrational oscillations on opposite sides (i.e., to the red or blue) of this node, and spectral fingering due to vibrational overtones and combinations. Our calculations make a vibrationally abrupt approximation for the incident pump and probe pulses, but properly account for temporal pulse overlap and signal turn-on, rather than neglecting pulse overlap or assuming delta-function excitations, as are sometimes done. PMID:27155654

  16. FE K EMISSION AND ABSORPTION FEATURES IN THE XMM-EPIC SPECTRUM OF THE SEYFERT GALAXY IC 4329A

    NASA Technical Reports Server (NTRS)

    Markowitz, A.; Reeves, J. N.; Braito, V.

    2001-01-01

    We present a re-analysis of the XMM-Newton long-look of the X-ray bright Seyfert galaxy IC 4329a. The Fe K bandpass is dominated by two peaks, consistent with emission from neutral or near-neutral Fe Ka and KP. A relativistic diskline model whereby both peaks are the result of one doubly-peaked diskline profile is found to be a poor description of the data. Models using two relativistic disklines are found to describe the emission profile well. A low-inclination, moderately-relativistic dual-diskline model is possible if the contribution from narrow components, due to distant material, is small or absent. A high-inclination, moderately relativistic profile for each peak is possible if there are roughly equal contributions from both the broad and narrow components. Upper limits on Fe XXV and Fe XXVI emission and absorption at the systemic velocity of IC 4329a are obtained. We also present the results of RXTE monitoring of this source obtained so far; the combined XMM-Newton and RXTE data sets allow us to explore the time-resolved spectral behavior of this source on time scales ranging from hours to 2 years. We find no strong evidence for variability of the Fe Ka emission line on any time scale probed, likely due to the minimal level of continuum variability. We detect a narrow absorption line, at a energy of 7.68 keV in the rest frame of the source; its significance has been confirmed using Monte Carlo simulations. This feature is most likely due to absorption from Fe XXVI blueshifted to approximately 0.1c relative to the systemic velocity, making IC 4329a the lowest-redshift AGN known with a high-velocity, highly-ionized outflow component. As is often the case with similar outflows seen in high-luminosity quasars, the estimated mass outflow rate is larger than the inflow accretion rate, signaling that the outflow represents a substantial portion of the total energy budget of the AGN. The outflow could arise from a radiatively-driven disk wind, or it may be in the

  17. Studying Absorption Line Feature in the Relativistic Jet Source GRS 1915+105

    NASA Technical Reports Server (NTRS)

    Tavani, Marco

    1998-01-01

    The galactic superluminal source GRS 1915+105 is among the most interesting objects in our Galaxy. It is subject to erratic accretion instabilities with energization of relativistic jets producing X-ray, optical and radio emission. This source was observed by ASCA on Sept. 27, 1994, April 20, 1995, October 23, 1996 and April 25, 1997 as part of a long timescale investigation. We detected strong variability of the source, and in particular the existence of burst/dip structure in October 1996 and April 1997. Clear evidence of transient absorption features at 6.7, 7.0 and 8.0 keV was obtained for the first time in September 1994 and April 1995. Given the phenomenology of plasmoid energization and ejection, these transient spectral features might be produced by material entrained in the radio jets or in other high-velocity outflows. Our contribution to the interpretation is to incorporate these observations into a overall theoretical picture for GRS 1915+105 also taking into account other observations by XTE and BSAX. The emerging picture is complex. The central source is subject to (most likely) super-Eddington instabilities mediated by magnetic field build-up, reconnection and dissipation in the form of blobs that eventually leads to the formation of transient spectral features from the surrounding of the plasmoid emitting region. A comprehensive theoretical investigation is in progress.

  18. Dark Hearts in the Perseus Cluster Galaxies: A Study of Dust Absorption Features

    NASA Astrophysics Data System (ADS)

    Hooper, Eric Jon; Wojtaszek, M.; Gallagher, J. S.

    2013-01-01

    Indicators of a cool interstellar medium, such as dust features and HI emission, are more prevalent in early type galaxies than once thought. Yet it is still difficult to understand their presence in the cores of massive clusters. The hot intracluster medium can strip low-density gas from infalling galaxies via ram pressure or can heat the gas past its escape velocity. Nevertheless, galaxies with cool ISM in the form of dust do exist in the Coma Cluster. Here we report on several such systems observed near the core of the Perseus Cluster, the nearest massive cluster of galaxies (D = 70 Mpc). Perseus is an optically unrelaxed cluster with an extensive hot ICM. It also contains several high-velocity galaxies, including a system infalling towards NGC 1275 at a relative speed of ~3000 km/sec, which suggests a continued accretion of systems from the cluster's surroundings. We detect dust features in early-type galaxies through the presence of optical absorption, visible in the form of very circular rings, dark spiral arms and disk systems, or both. These features range in size from 50 to 1700 parsecs. We suggest that these components may be remnants of evolutionary pre-processing in groups that occurs as objects fall into the Perseus cluster. We also discuss their existence in terms of survival time scales for cold ISM in the early-type members of a rich galaxy cluster.

  19. Effect of cell-size on the energy absorption features of closed-cell aluminium foams

    NASA Astrophysics Data System (ADS)

    Nammi, S. K.; Edwards, G.; Shirvani, H.

    2016-11-01

    The effect of cell-size on the compressive response and energy absorption features of closed-cell aluminium (Al) foam were investigated by finite element method. Micromechanical models were constructed with a repeating unit-cell (RUC) which was sectioned from tetrakaidecahedra structure. Using this RUC, three Al foam models with different cell-sizes (large, medium and small) and all of same density, were built. These three different cell-size pieces of foam occupy the same volume and their domains contained 8, 27 and 64 RUCs respectively. However, the smaller cell-size foam has larger surface area to volume ratio compared to other two. Mechanical behaviour was modelled under uniaxial loading. All three aggregates (3D arrays of RUCs) of different cell-sizes showed an elastic region at the initial stage, then followed by a plateau, and finally, a densification region. The smaller cell size foam exhibited a higher peak-stress and a greater densification strain comparing other two cell-sizes investigated. It was demonstrated that energy absorption capabilities of smaller cell-size foams was higher compared to the larger cell-sizes examined.

  20. Old stellar populations. 5: Absorption feature indices for the complete LICK/IDS sample of stars

    NASA Technical Reports Server (NTRS)

    Worthey, Guy; Faber, S. M.; Gonzalez, J. Jesus; Burstein, D.

    1994-01-01

    Twenty-one optical absorption features, 11 of which have been previously defined, are automatically measured in a sample of 460 stars. Following Gorgas et al., the indices are summarized in fitting functions that give index strengths as functions of stellar temperature, gravity, and (Fe/H). This project was carried out with the purpose of predicting index strengths in the integrated light of stellar populations of different ages and metallicities, but the data should be valuable for stellar studies in the Galaxy as well. Several of the new indices appear to be promising indicators of metallicity for old stellar populations. A complete list of index data and atmospheric parameters is available in computer-readable form.

  1. Characterization of fine resolution field spectrometers using solar Fraunhofer lines and atmospheric absorption features.

    PubMed

    Meroni, Michele; Busetto, Lorenzo; Guanter, Luis; Cogliati, Sergio; Crosta, Giovanni Franco; Migliavacca, Mirco; Panigada, Cinzia; Rossini, Micol; Colombo, Roberto

    2010-05-20

    The accurate spectral characterization of high-resolution spectrometers is required for correctly computing, interpreting, and comparing radiance and reflectance spectra acquired at different times or by different instruments. In this paper, we describe an algorithm for the spectral characterization of field spectrometer data using sharp atmospheric or solar absorption features present in the measured data. The algorithm retrieves systematic shifts in channel position and actual full width at half-maximum (FWHM) of the instrument by comparing data acquired during standard field spectroscopy measurement operations with a reference irradiance spectrum modeled with the MODTRAN4 radiative transfer code. Measurements from four different field spectrometers with spectral resolutions ranging from 0.05 to 3.5nm are processed and the results validated against laboratory calibration. An accurate retrieval of channel position and FWHM has been achieved, with an average error smaller than the instrument spectral sampling interval.

  2. Detection of a deep 3-microm absorption feature in the spectrum of Amalthea (JV).

    PubMed

    Takato, Naruhisa; Bus, Schelte J; Terada, Hiroshi; Pyo, Tae-Soo; Kobayashi, Naoto

    2004-12-24

    Near-infrared spectra of Jupiter's small inner satellites Amalthea and Thebe are similar to those of D-type asteroids in the 0.8- to 2.5-micrometer wavelength range. A deep absorption feature is detected at 3 micrometers in the spectra of the trailing side of Amalthea, which is similar to that of the non-ice components of Callisto and can be attributed to hydrous minerals. These surface materials cannot be explained if the satellite formed at its present orbit by accreting from a circumjovian nebula. Amalthea and Thebe may be the remnants of Jupiter's inflowing building blocks that formed in the outer part or outside of the circumjovian nebula.

  3. Detection of a Deep 3-μm Absorption Feature in the Spectrum of Amalthea (JV)

    NASA Astrophysics Data System (ADS)

    Takato, Naruhisa; Bus, Schelte J.; Terada, Hiroshi; Pyo, Tae-Soo; Kobayashi, Naoto

    2004-12-01

    Near-infrared spectra of Jupiter's small inner satellites Amalthea and Thebe are similar to those of D-type asteroids in the 0.8- to 2.5-micrometer wavelength range. A deep absorption feature is detected at 3 micrometers in the spectra of the trailing side of Amalthea, which is similar to that of the non-ice components of Callisto and can be attributed to hydrous minerals. These surface materials cannot be explained if the satellite formed at its present orbit by accreting from a circumjovian nebula. Amalthea and Thebe may be the remnants of Jupiter's inflowing building blocks that formed in the outer part or outside of the circumjovian nebula.

  4. Detection of a deep 3-microm absorption feature in the spectrum of Amalthea (JV).

    PubMed

    Takato, Naruhisa; Bus, Schelte J; Terada, Hiroshi; Pyo, Tae-Soo; Kobayashi, Naoto

    2004-12-24

    Near-infrared spectra of Jupiter's small inner satellites Amalthea and Thebe are similar to those of D-type asteroids in the 0.8- to 2.5-micrometer wavelength range. A deep absorption feature is detected at 3 micrometers in the spectra of the trailing side of Amalthea, which is similar to that of the non-ice components of Callisto and can be attributed to hydrous minerals. These surface materials cannot be explained if the satellite formed at its present orbit by accreting from a circumjovian nebula. Amalthea and Thebe may be the remnants of Jupiter's inflowing building blocks that formed in the outer part or outside of the circumjovian nebula. PMID:15618511

  5. Revealing spectral features in two-photon absorption spectrum of Hoechst 33342: a combined experimental and quantum-chemical study.

    PubMed

    Olesiak-Banska, Joanna; Matczyszyn, Katarzyna; Zaleśny, Robert; Murugan, N Arul; Kongsted, Jacob; Ågren, Hans; Bartkowiak, Wojciech; Samoc, Marek

    2013-10-10

    We present the results of wide spectral range Z-scan measurements of the two-photon absorption (2PA) spectrum of the Hoechst 33342 dye. The strongest 2PA of the dye in aqueous solution is found at 575 nm, and the associated two-photon absorption cross section is 245 GM. A weak but clearly visible 2PA band at ∼850 nm is also observed, a feature that could not be anticipated from the one-photon absorption spectrum. On the basis of the results of hybrid quantum mechanics/molecular mechanics calculations, we put forward a notion that the long-wavelength feature observed in the two-photon absorption spectrum of Hoechst 33342 is due to the formation of dye aggregates. PMID:24016295

  6. Search for QSOS Suitable for Subsequent Observation of he II 304 Absorption Arising in the IGM, Ly-Alpha and ... PART2

    NASA Astrophysics Data System (ADS)

    Tytler, David

    1991-07-01

    THIS IS PART TWO OF PROPOSAL 3801, CONTAINING 55 TARGETS OF PRIORITY 7,8 AND 9. EXCEPT FOR TARGETS, THIS PROPOSAL IS IDENTICAL TO 3801, WHICH HAS 87 TARGETS OF PRIORITY 3,4,5 AND 6. Ultraviolet images will be obtained in snapshot mode of the 500 known high-redshift (z > 2.8) QSOs in order to identify the few (about 20) targets which have sufficient ultraviolet flux for subsequent FOC/FOS or GHRS observations of He II 304. The detection of absorption by the Helium II Lyman-alpha line at 304 A, one of the most exciting prospects of the HST, will provide the first direct detection of the diffuse intergalactic medium (IGM). The absence of Gunn-Peterson H I 1215 absorption shows that the IGM is hot and/or of very low density, thus He I 584 is not expected to be observable. He II 304--the most promising line--should be observable from three sources: the diffuse IGM, the discrete Ly-alpha clouds, and the much rarer metal line absorption systems. The Gunn-Peterson continuum optical depth is not well constrained by models (range 0.3-3000). The mere detection of only one QSO below 304 A would rule out many models, limiting the IGM density, temperature, and ionization mechanisms. Similarly the total absence of flux from several targets would rule out other models.

  7. Search for QSOS Suitable for Subsequent Observation of he II 304 Absorption Arising in the IGM, Ly-Alpha and ... PART3

    NASA Astrophysics Data System (ADS)

    Tytler, David

    1991-07-01

    THIS IS PART Three OF PROPOSAL 3801. IT CONTAINS 40 TARGETS OF HIGH PRIORITY. EXCEPT FOR TARGETS, THIS PROPOSAL IS IDENTICAL TO 3801. Targets are in order of decreasing priority. Priority matters a lot. Best targets are listed first. Ultraviolet images will be obtained in snapshot mode of the 500 known high-redshift (z > 2.8) QSOs in order to identify the few (about 20) targets which have sufficient ultraviolet flux for subsequent FOC/FOS or GHRS observations of He II 304. The detection of absorption by the Helium II Lyman-alpha line at 304 A, one of the most exciting prospects of the HST, will provide the first direct detection of the diffuse intergalactic medium (IGM). The absence of Gunn-Peterson H I 1215 absorption shows that the IGM is hot and/or of very low density, thus He I 584 is not expected to be observable. He II 304--the most promising line--should be observable from three sources: the diffuse IGM, the discrete Ly-alpha clouds, and the much rarer metal line absorption systems. The Gunn-Peterson continuum optical depth is not well constrained by models (range 0.3-3000). The mere detection of only one QSO below 304 A would rule out many models, limiting the IGM density, temperature, and ionization mechanisms. Similarly the total absence of flux from several targets would rule out other models.

  8. A universal feature in the optical absorption spectrum associated with hydrogenated amorphous silicon: A dimensionless joint density of states analysis

    NASA Astrophysics Data System (ADS)

    Thevaril, Jasmin J.; O'Leary, Stephen K.

    2016-10-01

    Using a dimensionless joint density of states formalism for the quantitative characterization of the optical response associated with hydrogenated amorphous silicon, a critical comparative analysis of a large number of different optical absorption data sets is considered. When these data sets are cast into this dimensionless framework, we observe a trend that is almost completely coincident for all of the data sets considered. This suggests that there is a universal feature associated with the optical absorption spectrum of hydrogenated amorphous silicon.

  9. A search for ultraviolet circumstellar gas absorption features in alpha Piscis Austrinus (Fomalhaut), a possible Beta Pictoris-like system

    NASA Technical Reports Server (NTRS)

    Cheng, K.-P.; Bruhweiler, Fred C.; Kondo, Yoji

    1994-01-01

    Archival high-dispersion International Ultraviolet Explorer (IUE) spectra have been used to search for circumstellar gas absorption features in alpha PsA (A3 V), a nearby (6.7 pc) proto-planetary system candidate. Recent sub-millimeter mapping observations around the region of alpha PsA indicate a spatially resolved dust disk like the one seen around Beta Pic. To determine how closely this putative disk resembles that of Beta Pic, we have searched for signatures of circumstellar gaseous absorption in all the available IUE high-dispersion data of alpha PsA. Examination of co-added IUE spectra shows weak circumstellar absorptions from excited levels in the resonance multiplet of Fe II near 2600 A. We also conclude that the sharp C I feature near 1657 A, previously identified as interstellar absorption toward alpha PsA, likely has a circumstellar origin. However, because the weakness of these absorption features, we will consider the presence of circumstellar gas as tentative and should be verified by using the Goddard High-Resolution Spectrograph aboard the Hubble Space Telescope. No corresponding circumstellar absorption is detected in higher ionization Fe III and Al III. Since the collisionally ionized nonphotospheric Al III resonance absorption seen in Beta Pic is likely formed close to the stellar surface, its absence in the UV spectra of alpha PsA could imply that, in contrast with Beta Pic, there is no active gaseous disk infall onto the central star. In the alpha PsA gaseous disk, if we assume a solar abundance for iron and all the iron is in the form of Fe II, plus a disk temperature of 5000 K, the Fe II UV1 absorption at 2611.8743 A infers a total hydrogen column density along the line of sight through the circumstellar disk of N(H) approximately equals 3.8 x 10(exp 17)/cm.

  10. A search for absorption features in the afterglow of the unusual GRB 130925A

    NASA Astrophysics Data System (ADS)

    Bellm, Eric

    2012-09-01

    GRB 130925A produced several emission episodes triggering Swift-BAT, Fermi-GBM, and MAXI. The extraordinary length of this emission--over 10^4 seconds--would give GRB 130925A one of the highest total durations ever observed for a gamma-ray burst. While the initial bursting phase was similar to that of the the relativistic tidal disruption event Swift J1644+57, starting at 10^4 seconds after the trigger this event has entered a steady decay phase without new bursts (www.swift.ac.uk/xrt_curves/00571830/). Its classification is thus uncertain, as neither the long GRB class nor Swift J1644 provide direct parallels. Our NuSTAR spectroscopy during the decay phase has revealed evidence for a broad absorption feature never previously observed for either GRB afterglows or for tidal disruption events. Chandra observations will enable searches for lower-energy lines which may constrain the ionization state of this unprecedented event.

  11. A variable absorption feature in the X-ray spectrum of a magnetar.

    PubMed

    Tiengo, Andrea; Esposito, Paolo; Mereghetti, Sandro; Turolla, Roberto; Nobili, Luciano; Gastaldello, Fabio; Götz, Diego; Israel, Gian Luca; Rea, Nanda; Stella, Luigi; Zane, Silvia; Bignami, Giovanni F

    2013-08-15

    Soft-γ-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are slowly rotating, isolated neutron stars that sporadically undergo episodes of long-term flux enhancement (outbursts) generally accompanied by the emission of short bursts of hard X-rays. This behaviour can be understood in the magnetar model, according to which these sources are mainly powered by their own magnetic energy. This is supported by the fact that the magnetic fields inferred from several observed properties of SGRs and AXPs are greater than-or at the high end of the range of-those of radio pulsars. In the peculiar case of SGR 0418+5729, a weak dipole magnetic moment is derived from its timing parameters, whereas a strong field has been proposed to reside in the stellar interior and in multipole components on the surface. Here we show that the X-ray spectrum of SGR 0418+5729 has an absorption line, the properties of which depend strongly on the star's rotational phase. This line is interpreted as a proton cyclotron feature and its energy implies a magnetic field ranging from 2 × 10(14) gauss to more than 10(15) gauss. PMID:23955229

  12. A variable absorption feature in the X-ray spectrum of a magnetar.

    PubMed

    Tiengo, Andrea; Esposito, Paolo; Mereghetti, Sandro; Turolla, Roberto; Nobili, Luciano; Gastaldello, Fabio; Götz, Diego; Israel, Gian Luca; Rea, Nanda; Stella, Luigi; Zane, Silvia; Bignami, Giovanni F

    2013-08-15

    Soft-γ-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are slowly rotating, isolated neutron stars that sporadically undergo episodes of long-term flux enhancement (outbursts) generally accompanied by the emission of short bursts of hard X-rays. This behaviour can be understood in the magnetar model, according to which these sources are mainly powered by their own magnetic energy. This is supported by the fact that the magnetic fields inferred from several observed properties of SGRs and AXPs are greater than-or at the high end of the range of-those of radio pulsars. In the peculiar case of SGR 0418+5729, a weak dipole magnetic moment is derived from its timing parameters, whereas a strong field has been proposed to reside in the stellar interior and in multipole components on the surface. Here we show that the X-ray spectrum of SGR 0418+5729 has an absorption line, the properties of which depend strongly on the star's rotational phase. This line is interpreted as a proton cyclotron feature and its energy implies a magnetic field ranging from 2 × 10(14) gauss to more than 10(15) gauss.

  13. THE 3-5 {mu}m SPECTRUM OF NGC 1068 AT HIGH ANGULAR RESOLUTION: DISTRIBUTION OF EMISSION AND ABSORPTION FEATURES ACROSS THE NUCLEAR CONTINUUM SOURCE

    SciTech Connect

    Geballe, T. R.; Mason, R. E.; Rodriguez-Ardila, A.; Axon, D. J.

    2009-08-20

    We report moderate resolution 3-5 {mu}m spectroscopy of the nucleus of NGC 1068 obtained at 0.''3 (20 pc) resolution with the spectrograph slit aligned approximately along the ionization cones of the active galactic nucleus. The deconvolved full width at half-maximum of the nuclear continuum source in this direction is 0.''3. Four coronal lines of widely different excitations were detected; the intensity of each peaks near radio knot C, approximately 0.''3 north of the infrared continuum peak, where the radio jet changes direction. Together with the broadened line profiles observed near that location, this suggests that shock ionization is the dominant excitation mechanism of the coronal lines. The depth of the 3.4 {mu}m hydrocarbon absorption is maximum at and just south of the continuum peak, similar to the 10 {mu}m silicate absorption. That and the similar and rapid variations of the optical depths of both features across the nucleus suggest that substantial portions of both arise in a dusty environment just in front of the continuum source(s). A new and tighter limit is set on the column density of CO. Although clumpy models of the dust screen might explain the shallowness of the silicate feature, the presence of the 3.4 {mu}m feature and the absence of CO are strongly reminiscent of Galactic diffuse cloud environments and a consistent explanation for them and the observed silicate feature is found if all three phenomena occur in such an environment, existing as close as 10 pc to the central engine.

  14. The initial mass functions of M31 and M32 through far red stellar absorption features

    NASA Astrophysics Data System (ADS)

    Zieleniewski, Simon; Houghton, Ryan C. W.; Thatte, Niranjan; Davies, Roger L.

    2015-09-01

    Using the Oxford Short Wavelength Integral Field specTrograph, we investigate radial variations of several initial mass function (IMF) dependent absorption features in M31 and M32. We obtain high signal-to-noise spectra at six pointings along the major axis of M31 out to ˜700 arcsec (2.7 kpc) and a single pointing of the central 10 pc for M32. In M31 the sodium Na I λ8190 index shows a flat equivalent width profile at ˜0.4 Å through the majority of the bulge, with a strong gradient up to 0.8 Å in the central 10 arcsec (38 pc); the Wing-Ford FeH λ9916 index is measured to be constant at 0.4 Å for all radii; and calcium triplet CaT λλ8498, 8542, 8662 shows a gradual increase through the bulge towards the centre. M32 displays flat profiles for all three indices, with FeH at ˜0.5 Å, very high CaT at ˜0.8 Å and low Na I at ˜0.1 Å. We analyse these data using stellar population models. We find that M31 is well described on all scales by a Chabrier IMF, with a gradient in sodium enhancement of [Na/Fe] ˜ +0.3 dex in the outer bulge, rising within the central 10 arcsec to perhaps [Na/Fe] ˜ +1.0 dex in the nuclear region. We find M32 is described by a Chabrier IMF and young stellar age in line with other studies. Models show that CaT is much more sensitive to metallicity and [α/Fe] than to IMF. We note that the centres of M31 and M32 have very high stellar densities and yet we measure Chabrier IMFs in these regions.

  15. [Study on intestinal absorption features of oligosaccharides in Morinda officinalis How. with sigle-pass perfusion].

    PubMed

    Deng, Shao-Dong; Zhang, Peng; Lin, Li; Xiao, Feng-Xia; Lin, Jing-Ran

    2015-01-01

    To study the in situ intestinal absorption of five oligosaccharides contained in Morinda officinalis How. (sucrose, kestose, nystose, 1F-Fructofuranosyinystose and Bajijiasu). The absorption of the five oligosaccharides in small intestine (duodenum, jejunum and ileum) and colon of rats and their contents were investigated by using in situ single-pass perfusion model and HPLC-ELSD. The effects of drug concentration, pH in perfusate and P-glycoprotein inhibitor on the intestinal absorption were investigated to define the intestinal absorption mechanism of the five oligosaccharides in rats. According to the results, all of the five oligosaccharides were absorbed in the whole intestine, and their absorption rates were affected by the pH of the perfusion solution, drug concentration and intestinal segments. Verapamil Hydrochloride could significantly increase the absorptive amount of sucrose and Bajijiasu, suggesting sucrose and Bajijiasu are P-gp's substrate. The five oligosaccharides are absorbed mainly through passive diffusion in the intestinal segments, without saturated absorption. They are absorbed well in all intestines and mainly in duodenum and jejunum.

  16. Measurement and feature analysis of absorption spectra of four algal species

    NASA Astrophysics Data System (ADS)

    Zhu, Jianhua; Zhou, Hongli; Han, Bing; Li, Tongji

    2016-04-01

    Two methods for particulate pigments (i.e., quantitative filter technique, QFT, and in vivo measurement, InVivo, respectively) and two methods for dissolved pigments (i.e., Acetone Extracts, AceEx, and high-performance liquid chromatography, HPLC, respectively) were used to obtain the optical absorption coefficient spectra for cultures of four typical algal species. Through normalization and analysis of the spectra, it is shown that (1) the four methods are able to measure optical absorption spectra of particulate and/or dissolved pigments; (2) that the optical absorption spectra of particulate and dissolved pigments were consistent in terms of the peak position in the blue wavelength, and the difference of the peak position in the near infrared wavelength was ~10 nm between each other; and (3) that the leveling effect of the absorption spectra of particulate pigments was significant. These four methods can all effectively measure the absorption coefficients of phytoplankton pigments, while each one has its unique advantages in different applications. Therefore, appropriate method should be carefully selected for various application due to their intrinsic difference.

  17. 4.6 micron absorption features due to solid phase CO and cyano group molecules toward compact infrared sources

    NASA Technical Reports Server (NTRS)

    Lacy, J. H.; Baas, F.; Allamandola, L. J.; Van De Bult, C. E. P.; Persson, S. E.; Mcgregor, P. J.; Lonsdale, C. J.; Geballe, T. R.

    1984-01-01

    Spectra obtained at a resolving power of 840, for seven protostellar sources in the region of the 4.67-micron fundamental vibrational band of CO, indicate that the deep absorption feature in W33A near 4.61 microns consists of three features which are seen in other sources, but with varying relative strength. UV-irradiation laboratory experiments with 'dirty ice' temperature cycling allow the identification of two of the features cited with solid CO and CO complexed to other molecules. Cyano group-containing molecules have a lower vapor pressure than CO, and can therefore survive in much warmer environments. The formation and location of the CO- and CN-bearing grain mantles and sources of UV irradiation in cold molecular clouds are discussed. Plausible UV light sources can produce the observed cyano group features, but only under conditions in which local heat sources do not cause evaporation of the CO molecules prior to their photoprocessing.

  18. Preparation of Honeycomb SnO₂ Foams and Configuration-Dependent Microwave Absorption Features.

    PubMed

    Zhao, Biao; Fan, Bingbing; Xu, Yawei; Shao, Gang; Wang, Xiaodong; Zhao, Wanyu; Zhang, Rui

    2015-12-01

    Ordered honeycomb-like SnO2 foams were successfully synthesized by means of a template method. The honeycomb SnO2 foams were analyzed by X-ray diffraction (XRD), thermogravimetric and differential scanning calorimetry (TG-DSC), laser Raman spectra, scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR). It can be found that the SnO2 foam configurations were determined by the size of polystyrene templates. The electromagnetic properties of ordered SnO2 foams were also investigated by a network analyzer. The results reveal that the microwave absorption properties of SnO2 foams were dependent on their configuration. The microwave absorption capabilities of SnO2 foams were increased by increasing the size of pores in the foam configuration. Furthermore, the electromagnetic wave absorption was also correlated with the pore contents in SnO2 foams. The large and high amounts pores can bring about more interfacial polarization and corresponding relaxation. Thus, the perfect ordered honeycomb-like SnO2 foams obtained in the existence of large amounts of 322 nm polystyrene spheres showed the outstanding electromagnetic wave absorption properties. The minimal reflection loss (RL) is -37.6 dB at 17.1 GHz, and RL less than -10 dB reaches 5.6 GHz (12.4-18.0 GHz) with thin thickness of 2.0 mm. The bandwidth (<-10 dB, 90% microwave dissipation) can be monitored in the frequency regime of 4.0-18.0 GHz with absorber thickness of 2.0-5.0 mm. The results indicate that these ordered honeycomb SnO2 foams show the superiorities of wide-band, high-efficiency absorption, multiple reflection and scatting, high antioxidation, lightweight, and thin thickness.

  19. Features in optical absorption and photocurrent spectra of organic solar cells due to organic/organic interface

    NASA Astrophysics Data System (ADS)

    Ismail, Yasser A. M.; Soga, Tetsuo; Jimbo, Takashi

    2011-05-01

    We surprisingly found that, organic/organic interface had a direct and pronounced impact on optical absorption and photocurrent spectra of organic solar cell at a favorable wavelength region of the visible solar spectrum. The organic/organic interface was formed as a result of connection between coumarin 6 (C6): [6,6]-phenyl-C61 butyric acid methyl ester (PCBM) blend films and indium-tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS) electrode. Optical absorption measurement was carried out for ITO/PEDOT:PSS/C6:PCBM films, while external quantum efficiency measurement was carried out for ITO/PEDOT:PSS/C6:PCBM/Al solar cells, with varying C6:PCBM blend concentration. We found that, the C6:PCBM blend in the ITO/PEDOT:PSS/C6:PCBM films had an additional feature in the absorption spectra at the wavelength range of 520-800 nm, at which the C6 dye, PCBM, PEDOT:PSS, and ITO were transparent. An additional feature, also, appeared in photocurrent spectra of the C6:PCBM films in the ITO/PEDOT:PSS/C6:PCBM/Al solar cells at the same wavelength range. The new features in the optical absorption and photocurrent spectra of the investigated solar cells originated, in all probability, due to optically induced sup-band transitions in the C6:PCBM blend films at the interface with ITO/PEDOT:PSS electrode. Thus, the C6:PCBM blend films produced a charge carrier generation interface due to connection with ITO/PEDOT:PSS electrode. As a result of this charge carrier generation interface, the power conversion efficiency of the corresponding solar cell is improved. Taking into consideration these new findings, the high-band-gap organic materials will take more importance as sensitizers in organic optoelectronic applications.

  20. Determination of the in-flight spectral calibration of AVIRIS using atmospheric absorption features

    NASA Technical Reports Server (NTRS)

    Green, Robert O.

    1995-01-01

    Spectral calibration of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) as data are acquired in flight is essential to quantitative analysis of the measured upwelling spectral radiance. In each spectrum measured by AVIRIS in flight, there are numerous atmospheric gas absorption bands that drive this requirement for accurate spectral calibration. If the surface and atmospheric properties are measured independently, these atmospheric absorption bands may be used to deduce the in-flight spectral calibration of an imaging spectrometer. Both the surface and atmospheric characteristics were measured for a calibration target during an in-flight calibration experiment held at Lunar Lake, Nevada on April 5, 1994. This paper uses upwelling spectral radiance predicted for the calibration target with the MODTRAN radiative transfer code to validate the spectral calibration of AVIRIS in flight.

  1. Specific features of optical absorption in rare-earth orthoaluminate DyAlO3

    NASA Astrophysics Data System (ADS)

    Valiev, U. V.; Gruber, J. B.; Rakhimov, Sh. A.

    2003-04-01

    Polarization spectra of optical absorption of the 4 f-4 f transition 6 H 15/2 → 6 F 3/2 in the rare-earth orthoaluminate DyAlO3 are theoretically and experimentally studied at the temperature T=78 K. It is shown that the nontrivial character of the anisotropy of the polarization absorption spectra at low temperatures can be explained by the J-J mixing of excited multiplets of the 4 f 9 configuration of Dy3+ ions in a low-symmetry crystal field of the orthoaluminate structure. The energy and wave functions of the Stark sublevels within the excited 6 F 5/2 multiplet in the 4 f 9 configuration of the Dy3+ rare-earth ion in the crystal field of C s symmetry are numerically calculated.

  2. Strength of mineral absorption features in the transmitted component of near-infrared reflected light - First results from RELAB

    NASA Astrophysics Data System (ADS)

    Pieters, C. M.

    1983-11-01

    Bidirectional reflectance measurements are the only type of reflectance data available to the remote observer. For compositional interpretations, data are desired not only for identification of possible mineral components but also for modal abundance. The latter requires detailed information about the strength of absorption features. Using a new laboratory facility, the RELAB, laboratory data in the near infrared are presented that document effects of particle size, mineral mixtures, and viewing geometry for selected materials with well-developed absorption bands. The commonly observed increase in reflectance with decrease in particle size is also observed for absorption bands as well as a related decrease in absorption strength. For small particles in parts of the spectrum of maximum reflectance, however, a minor decrease in reflectance with a decrese in particle size is sometimes observed. Small particles dominate the observed characteristics of particulate surfaces, which contain a range of particle sizes. The mean optical path length (transmission through particles) of reflected radiation measured for a variety of particle sizes has an apparent upper limit of about 2 mm for particles of less than 250 microns. The typical number of particles involved in the optical path is less than 50.

  3. High-velocity ultraviolet iron, silicon, oxygen, and sulfur absorption features associated with the remnant of SN 1006

    NASA Technical Reports Server (NTRS)

    Fesen, Robert A.; Wu, Chi-Chao; Leventhal, Marvin; Hamilton, Andrew J. S.

    1988-01-01

    New low-dispersion IUE spectra of a faint sdOb star located in a direction near the center of the SN 1006 remnant are presented. The UV spectrum of the star exhibits several strong absorption features which are uncharacteristic of its optical sdOB star classification. The identification by Wu et al. (1983) of very broad absorption features at 1610, 2370, 2600 A as Fe II gas associated with the SN 1006 remnant is supported. The observed Fe II line profiles indicate a concentration of Fe(+) toward the remnant's center with a radial velocity range on the order of + or - 5000 km/s. Strong absorption lines at 1281, 1331, and 1420 A are interpreted as originating from clumps of O-, Si- and S-rich ejecta with central radial velocities in the range 5000-6500 km/s. The presence in the SN 1006 remnant of an expanding sphere of iron-rich ejecta interior to O-, Si-, and S-rich clumps of ejecta having velocities over the maximum seen for the Fe II absorbing gas is consistent with type Ia Sn observations and carbon deflagration models.

  4. Features of Pc5 pulsations in the geomagnetic field, auroral luminosity, and Riometer absorption

    NASA Astrophysics Data System (ADS)

    Belakhovsky, V. B.; Pilipenko, V. A.; Samsonov, S. N.; Lorentsen, D.

    2016-01-01

    Simultaneous morning Pc5 pulsations ( f ~ 3-5 mHz) in the geomagnetic field, aurora intensities (in the 557.7 and 630.0 nm oxygen emissions and the 471.0 nm nitrogen emission), and riometer absorption, were studied based on the CARISMA, CANMOS, and NORSTAR network data for the event of January 1, 2000. According to the GOES-8 satellite observations, these Pc5 geomagnetic pulsations are observed as incompressible Alfvén waves with toroidal polarization in the magnetosphere. Although the Pc5 pulsation frequencies in auroras, the geomagnetic field, and riometer absorption are close to one another, stable phase relationships are not observed between them. Far from all trains of geomagnetic Pc5 pulsations are accompanied by corresponding auroral pulsations; consequently, geomagnetic pulsations are primary with respect to auroral pulsations. Both geomagnetic and auroral pulsations propagate poleward, and the frequency decreases with increasing geomagnetic latitude. When auroral Pc5 pulsations appear, the ratio of the 557.7/630.0 nm emission intensity sharply increases, which indicates that auroral pulsations result from not simply modulated particle precipitation but also an additional periodic acceleration of auroral electrons by the wave field. A high correlation is not observed between Pc5 pulsations in auroras and the riometer absorption, which indicates that these pulsations have a common source but different generation mechanisms. Auroral luminosity modulation is supposedly related to the interaction between Alfvén waves and the region with the field-aligned potential drop above the auroral ionosphere, and riometer absorption modulation is caused by the scattering of energetic electrons by VLF noise pulsations.

  5. Cryptography based on the absorption/emission features of multicolor semiconductor nanocrystal quantum dots.

    PubMed

    Zhou, Ming; Chang, Shoude; Grover, Chander

    2004-06-28

    Further to the optical coding based on fluorescent semiconductor quantum dots (QDs), a concept of using mixtures of multiple single-color QDs for creating highly secret cryptograms based on their absorption/emission properties was demonstrated. The key to readout of the optical codes is a group of excitation lights with the predetermined wavelengths programmed in a secret manner. The cryptograms can be printed on the surfaces of different objects such as valuable documents for security purposes.

  6. Remote sensing of forage nutrients: Combining ecological and spectral absorption feature data

    NASA Astrophysics Data System (ADS)

    Knox, Nichola M.; Skidmore, Andrew K.; Prins, Herbert H. T.; Heitkönig, Ignas M. A.; Slotow, Rob; van der Waal, Cornelis; de Boer, William F.

    2012-08-01

    Forage quality in grassland-savanna ecosystems support high biomass of both wild ungulates and domestic livestock. Forage quality is however variable in both space and time. In this study findings from ecological and laboratory studies, focused on assessing forage quality, are combined to evaluate the feasibility of a remote sensing approach for predicting the spatial and temporal variations in forage quality. Spatially available ecological findings (ancillary data), and physically linked spectral data (absorption data) are evaluated in this study and combined to create models which predict forage quality (nitrogen, phosphorus and fibre concentrations) of grasses collected in the Kruger National Park, South Africa, and analysed in both dry and wet seasons. Models were developed using best subsets regression modelling. Ancillary data alone, could predict forage components, with a higher goodness of fit and predictive capability, than absorption data (Ancillary: Radj2=0.42-0.74 compared with absorption: Radj2=0.11-0.51, and lower RMSE values for each nutrient produced by the ancillary models). Plant species and soil classes were found to be ecological variables most frequently included in prediction models of ancillary data. Models in which both ancillary and absorption variables were included, had the highest predictive capabilities ( Radj2=0.49-0.74 and lowest RMSE values) compared to models where data sources were derived from only one of the two groups. This research provides an important step in the process of creating biochemical models for mapping forage nutrients in savanna systems that can be generalised seasonally over large areas.

  7. Time variations of an absorption feature in the spectrum of the gamma-ray burst on 1980 April 19

    NASA Technical Reports Server (NTRS)

    Dennis, B. R.; Frost, K. J.; Kiplinger, A. L.; Orwig, L. E.; Desai, U.; Cline, T. L.

    1982-01-01

    The photon number spectrum integrated over the impulsive part of the event is shown to fit a thermal bremsstrahlung function with a temperature of 330 + or - 70 keV at energies between 151 and 487 keV. At lower energies, the data points lie considerably below this function, indicating a broad absorption feature extending down to values less than or equal to 28 keV, the lowest energy measured. The upper energy of this absorption feature varies from 100 to 150 keV on a time scale less than or equal to 0.5 s. This event is interpreted as a typical gamma ray burst, even though it is still considered remotely possible that it is of solar origin. The spectral features, together with their variability, are interpreted in terms of electron interactions at the cyclotron resonance frequency in magnetic fields of 10 to the 12th - 10 to the 13th gauss close to the surface of a neutron star.

  8. Mapping vegetation types with the multiple spectral feature mapping algorithm in both emission and absorption

    NASA Technical Reports Server (NTRS)

    Clark, Roger N.; Swayze, Gregg A.; Koch, Christopher; Ager, Cathy

    1992-01-01

    Vegetation covers a large portion of the Earth's land surface. Remotely sensing quantitative information from vegetation has proven difficult because in a broad sense, all vegetation is similar from a chemical viewpoint, and most healthy plants are green. Plant species are generally characterized by the leaf and flower or fruit morphology, not by remote sensing spectral signatures. But to the human eye, many plants show varying shades of green, so there is direct evidence for spectral differences between plant types. Quantifying these changes in a predictable manner has not been easy. The Clark spectral features mapping algorithm was applied to mapping spectral features in vegetation species.

  9. Magnetic feature and near-infrared absorption of a [Pt(mnt)2]--based H-bond supramolecular crystal

    NASA Astrophysics Data System (ADS)

    Li, Cui-Ping; Nie, Li; Pei, Wen-Bo; Li, Li; Tian, Zheng-Fang; Liu, Jian-Lan; Gao, Xu-Sheng; Ren, Xiao-Ming

    2016-11-01

    A new salt [H2DABCO][Pt(mnt)2]2 (1) (mnt2-=maleonitriledithiolate and H2DABCO2+ is diprotonated 1,4-diazabicyclo[2.2.2]octane) has been synthesized; its crystal structure, magnetic and near-IR absorption properties have been investigated. Two different [Pt(mnt)2]- anions form the strong π-dimers, labeled as Pt(1)-dimer and Pt(2)-dimer, with quite shorter Pt…Pt and S…S distances and molecular plane-to-plane distance (<3.5 Å) within a dimer. The [Pt(mnt)2]22- π-dimers are connected through the cations in the strong H-bond manner to form three-dimensional H-bond supramolecular crystal. The salt shows weak paramagnetism in 1.99-300 K and this is due to the existence of strong antiferromagnetic coupling within a π-dimer. In addition, a small thermal hysteresis loop is observed at ca. 120 K, indicating that a phase transition probably occurs that is further confirmed by variable-temperature IR spectra. Another fascinating functionality of 1 is the intense near-IR absorption in the region of 750-2500 nm, and this near-IR absorption feature makes it to be a promising optical material.

  10. Automated extraction of absorption features from Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and Geophysical and Environmental Research Imaging Spectrometer (GERIS) data

    NASA Technical Reports Server (NTRS)

    Kruse, Fred A.; Calvin, Wendy M.; Seznec, Olivier

    1988-01-01

    Automated techniques were developed for the extraction and characterization of absorption features from reflectance spectra. The absorption feature extraction algorithms were successfully tested on laboratory, field, and aircraft imaging spectrometer data. A suite of laboratory spectra of the most common minerals was analyzed and absorption band characteristics tabulated. A prototype expert system was designed, implemented, and successfully tested to allow identification of minerals based on the extracted absorption band characteristics. AVIRIS spectra for a site in the northern Grapevine Mountains, Nevada, have been characterized and the minerals sericite (fine grained muscovite) and dolomite were identified. The minerals kaolinite, alunite, and buddingtonite were identified and mapped for a site at Cuprite, Nevada, using the feature extraction algorithms on the new Geophysical and Environmental Research 64 channel imaging spectrometer (GERIS) data. The feature extraction routines (written in FORTRAN and C) were interfaced to the expert system (written in PROLOG) to allow both efficient processing of numerical data and logical spectrum analysis.

  11. Evidence for cyclotron absorption from spectral features in gamma-ray bursts seen with Ginga

    NASA Technical Reports Server (NTRS)

    Murakami, T.; Fujii, M.; Hayashida, K.; Itoh, M.; Nishimura, J.

    1988-01-01

    New observations by the gamma-ray burst detector on board the Ginga satellite, which has two well-calibrated detectors covering a wide energy range of 1.5 to 375 keV, are reported. The spectral features obtained are consistent with first and second cyclotron harmonics. This finding is taken as strong evidence for the magnetized neutron star model of gamma-ray bursts.

  12. THE 217.5 nm BAND, INFRARED ABSORPTION, AND INFRARED EMISSION FEATURES IN HYDROGENATED AMORPHOUS CARBON NANOPARTICLES

    SciTech Connect

    Duley, W. W.; Hu, Anming E-mail: a2hu@uwaterloo.ca

    2012-12-20

    We report on the preparation of hydrogenated amorphous carbon nanoparticles whose spectral characteristics include an absorption band at 217.5 nm with the profile and characteristics of the interstellar 217.5 nm feature. Vibrational spectra of these particles also contain the features commonly observed in absorption and emission from dust in the diffuse interstellar medium. These materials are produced under ''slow'' deposition conditions by minimizing the flux of incident carbon atoms and by reducing surface mobility. The initial chemistry leads to the formation of carbon chains, together with a limited range of small aromatic ring molecules, and eventually results in carbon nanoparticles having an sp {sup 2}/sp {sup 3} ratio Almost-Equal-To 0.4. Spectroscopic analysis of particle composition indicates that naphthalene and naphthalene derivatives are important constituents of this material. We suggest that carbon nanoparticles with similar composition are responsible for the appearance of the interstellar 217.5 nm band and outline how these particles can form in situ under diffuse cloud conditions by deposition of carbon on the surface of silicate grains. Spectral data from carbon nanoparticles formed under these conditions accurately reproduce IR emission spectra from a number of Galactic sources. We provide the first detailed fits to observational spectra of Type A and B emission sources based entirely on measured spectra of a carbonaceous material that can be produced in the laboratory.

  13. Far-IR Absorption Features of Titan Aerosol Analogs Produced from Aromatic Precursors

    NASA Astrophysics Data System (ADS)

    Sebree, Joshua; Trainer, M. G.; Anderson, C. M.; Loeffler, M. J.

    2012-10-01

    The arrival of the Cassini spacecraft in orbit around Saturn has led to the discovery of benzene (C6H6) at ppm levels, as well as large positive ions in Titan’s atmosphere, tentatively identified as polycyclic aromatic hydrocarbons (PAHs).[1] The presence of aromatic molecules, which are photolytically active in the ultraviolet, may be an important part of the formation of aerosol particles in Titan’s haze layers, even at these low concentrations. To date, there have been no laboratory experiments in the literature exploring this area of study. The analysis of data from the Composite Infrared Spectrometer (CIRS) on-board Cassini has recently uncovered a broad emission feature centered at 140 cm-1 in the far-IR that is unique to the aerosol layers of Titan’s atmosphere.[2] Current optical constants from laboratory-generated aerosol analogs have been unable to reproduce this feature.[3,4] From the broadness of this feature, we speculate that the emission is a blended composite of low-energy vibrations of large molecules such as PAHs and their nitrogen containing counterparts, polycyclic aromatic nitrogen heterocycles (PANHs). We hypothesize that the inclusion of trace amounts of aromatic precursors will aid in the production of these large structures in the laboratory-generated aerosols. In this study, we perform UV irradiation of several aromatic precursors, both with and without nitrogen heteroatoms, to understand their influence on the observable characteristics of the aerosol. Measured optical and chemical properties will be compared to those formed from CH4/N2 mixtures [5,6] as well as to those from Cassini observations. [1] Waite, J. H., et al. (2007) Science 316 870-875. [2] Anderson, C.M, et al. (2011) Icarus 212 762-778. [3] Khare, B.N., et al. (1984) Icarus 60 127-137. [4] Imanaka, H., et al. (2012) Icarus 218 247-261. [5] Trainer, M.G., et al. (2006) PNAS 103 18035-18042. [6] Trainer, M.G., et al. (2012) Astrobiology 12 315-326.

  14. Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the QSO PG 1351+641. 2.5

    NASA Technical Reports Server (NTRS)

    Zheng, W.; Kriss, G. A.; Wang, J. X.; Brotherton, M.; Oegerle, W. R.; Blair, W. P.; Davidsen, A. F.; Green, R. F.; Hutchings, J. B.; Kaiser, M. E.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    We present a moderate-resolution (approximately 20 km/s) spectrum of the broad-absorption line QSO PG 1351+64 between 915-1180 angstroms, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). Additional low-resolution spectra at longer wavelengths were also obtained with the Hubble Space Telescope (HST) and ground-based telescopes. Broad absorption is present on the blue wings of C III lambda977, Ly-beta, O VI lambda-lambda-1032,1038, Ly-alpha, N V lambda-lambda-1238,1242, Si IV lambda-lambda-1393,1402, and C IV lambda-lambda-1548,1450. The absorption profile can be fitted with five components at velocities of approximately -780, -1049, -1629, -1833, and -3054 km/s with respect to the emission-line redshift of z = 0.088. All the absorption components cover a large fraction of the continuum source as well as the broad-line region. The O VI emission feature is very weak, and the O VI/Ly-alpha flux ratio is 0.08, one of the lowest among low-redshift active galaxies and QSOs. The ultraviolet continuum shows a significant change in slope near 1050 angstroms in the restframe. The steeper continuum shortward of the Lyman limit extrapolates well to the observed weak X-ray flux level. The absorbers' properties are similar to those of high-redshift broad absorption-line QSOs. The derived total column density of the UV absorbers is on the order of 10(exp 21)/s, unlikely to produce significant opacity above 1 keV in the X-ray. Unless there is a separate, high-ionization X-ray absorber, the QSO's weak X-ray flux may be intrinsic. The ionization level of the absorbing components is comparable to that anticipated in the broad-line region, therefore the absorbers may be related to broad-line clouds along the line of sight.

  15. Ultraviolet Broad Absorption Features and the Spectral Energy Distribution of the QSO PG 1351+64. 3.1

    NASA Technical Reports Server (NTRS)

    Zheng, W.; Kriss, G. A.; Wang, J. X.; Brotherton, M.; Oegerle, W. R.; Blair, W. P.; Davidsen, A. F.; Green, R. F.; Hutchings, J. B.; Kaiser, M. E.; Fisher, R. (Technical Monitor)

    2001-01-01

    We present a moderate-resolution (approximately 20 km s(exp -1) spectrum of the mini broad absorption line QSO PG 1351+64 between 915-1180 A, obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE). Additional low-resolution spectra at longer wavelengths were also obtained with the Hubble Space Telescope (HST) and ground-based telescopes. Broad absorption is present on the blue wings of C III (lambda)977, Ly(beta), O VI (lambda)(lambda)1032,1038, Ly(alpha), N V (lambda)(lambda)1238,1242, Si IV (lambda)(lambda)1393,1402, and C IV (lambda)(lambda)1548,1450. The absorption profile can be fitted with five components at velocities of approximately -780, -1049, -1629, -1833, and -3054 km s(exp -1) with respect to the emission-line redshift of z = 0.088. All the absorption components cover a large fraction of the continuum source as well as the broad-line region. The O VI emission feature is very weak, and the O VI/Ly(alpha) flux ratio is 0.08, one of the lowest among low-redshift active galaxies and QSOs. The UV (ultraviolet) continuum shows a significant change in slope near 1050 A in the restframe. The steeper continuum shortward of the Lyman limit extrapolates well to the observed weak X-ray flux level. The absorbers' properties are similar to those of high-redshift broad absorption-line QSOs. The derived total column density of the UV absorbers is on the order of 10(exp 21) cm(exp -2), unlikely to produce significant opacity above 1 keV in the X-ray. Unless there is a separate, high-ionization X-ray absorber, the QSO's weak X-ray flux may be intrinsic. The ionization level of the absorbing components is comparable to that anticipated in the broad-line region, therefore the absorbers may be related to broad-line clouds along the line of sight.

  16. On the Putative Detection of z > 0 X-Ray Absorption Features in the Spectrum of Mrk 421

    NASA Astrophysics Data System (ADS)

    Rasmussen, Andrew P.; Kahn, Steven M.; Paerels, Frits; Herder, Jan Willem den; Kaastra, Jelle; de Vries, Cor

    2007-02-01

    In a series of papers, Nicastro et al. have reported the detection of z>0 O VII absorption features in the spectrum of Mrk 421 obtained with the Chandra Low Energy Transmission Grating Spectrometer (LETGS). We evaluate this result in the context of a high-quality spectrum of the same source obtained with the Reflection Grating Spectrometer (RGS) on XMM-Newton. The data comprise over 955 ks of usable exposure time and more than 2.6×104 counts per 50 mÅ at 21.6 Å. We concentrate on the spectrally clean region (21.3 <λ<22.5 ), where sharp features due to the astrophysically abundant O VII may reveal an intervening, warm-hot intergalactic medium (WHIM). We do not confirm detection of any of the intervening systems claimed to date. Rather, we detect only three unsurprising, astrophysically expected features down to the log(Ni)~14.6 (3 σ) sensitivity level. Each of the two purported WHIM features is rejected with a statistical confidence that exceeds that reported for its initial detection. While we cannot rule out the existence of fainter, WHIM related features in these spectra, we suggest that previous discovery claims were premature. A more recent paper by Williams et al. claims to have demonstrated that the RGS data we analyze here do not have the resolution or statistical quality required to confirm or deny the LETGS detections. We show that our analysis resolves the issues encountered by Williams et al. and recovers the full resolution and statistical quality of the RGS data. We highlight the differences between our analysis and those published by Williams et al. as this may explain our disparate conclusions.

  17. Detection of narrow C 4 and Si 4 absorption features in spectra of stars within 200 pc f the Sun

    NASA Technical Reports Server (NTRS)

    Molaro, P.; Beckman, J. E.; Franco, M.; Morossi, C.; Ramella, M.

    1984-01-01

    Detection of narrow (Beta lambda 0.5 A) absorption features in C 4 at lambda lambda 1548 and 1550 have been made in the spectra of 4 late B dwarfs within 200 pc of the Sun; the Si4 doublet at lambda lambda 1393 and 1403 shows up in two of them. It is argued that it is difficult to account for the strengths, widths, shapes, and C IV/Si IV ratios in terms consistent with a circumstellar origin except possibly for an asymmetric C IV component in one star (HD 185037). The most probable source is semi-torrid gas in the 50,000 K range forming the interfaces between cooler H 1 clouds and the ambient medium at coronal temperatures. Late B rapid rotators are used for local interstellar medium probing of this kind.

  18. Spectroscopic determination of leaf biochemistry using band-depth analysis of absorption features and stepwise multiple linear regression

    USGS Publications Warehouse

    Kokaly, R.F.; Clark, R.N.

    1999-01-01

    We develop a new method for estimating the biochemistry of plant material using spectroscopy. Normalized band depths calculated from the continuum-removed reflectance spectra of dried and ground leaves were used to estimate their concentrations of nitrogen, lignin, and cellulose. Stepwise multiple linear regression was used to select wavelengths in the broad absorption features centered at 1.73 ??m, 2.10 ??m, and 2.30 ??m that were highly correlated with the chemistry of samples from eastern U.S. forests. Band depths of absorption features at these wavelengths were found to also be highly correlated with the chemistry of four other sites. A subset of data from the eastern U.S. forest sites was used to derive linear equations that were applied to the remaining data to successfully estimate their nitrogen, lignin, and cellulose concentrations. Correlations were highest for nitrogen (R2 from 0.75 to 0.94). The consistent results indicate the possibility of establishing a single equation capable of estimating the chemical concentrations in a wide variety of species from the reflectance spectra of dried leaves. The extension of this method to remote sensing was investigated. The effects of leaf water content, sensor signal-to-noise and bandpass, atmospheric effects, and background soil exposure were examined. Leaf water was found to be the greatest challenge to extending this empirical method to the analysis of fresh whole leaves and complete vegetation canopies. The influence of leaf water on reflectance spectra must be removed to within 10%. Other effects were reduced by continuum removal and normalization of band depths. If the effects of leaf water can be compensated for, it might be possible to extend this method to remote sensing data acquired by imaging spectrometers to give estimates of nitrogen, lignin, and cellulose concentrations over large areas for use in ecosystem studies.We develop a new method for estimating the biochemistry of plant material using

  19. Spectroscopic Character and Spatial Distribution of Hydroxyl and Water Absorption Features Measured on the Lunar Surface by the Moon Mineralogy Mapper Imaging Spectrometer on Chandrayaan-1

    NASA Astrophysics Data System (ADS)

    Green, R. O.; Pieters, C. M.; Goswami, J.; Clark, R. N.; Annadurai, M.; Boardman, J. W.; Buratti, B. J.; Combe, J.; Dyar, M. D.; Head, J. W.; Hibbitts, C.; Hicks, M.; Isaacson, P.; Klima, R. L.; Kramer, G. Y.; Kumar, S.; Livo, K. E.; Lundeen, S.; Malaret, E.; McCord, T. B.; Mustard, J. F.; Nettles, J. W.; Petro, N. E.; Runyon, C. J.; Staid, M.; Sunshine, J. M.; Taylor, L. A.; Tompkins, S.; Varanasi, P.

    2009-12-01

    The Moon Mineralogy Mapper imaging spectrometer on Chandrayaan-1 has a broad spectral range from 430 to 3000 nm. By design, the range was specified to extend to 3000 nm to allow for possible detection of trace volatile compounds that possess absorption bands near 3000 nm. Soon after acquisition and calibration of a large fraction of the lunar surface in early February 2009, absorption features in the 2700 to 3000 nm region were detected over unexpectedly large regional areas. This extraordinary discovery has withstood extensive re-analysis and falsification efforts. We have concluded these absorption features are fundamentally present in the M3 measurements and are indicators of extensive hydroxyl and water-bearing materials occurring on the surface of the Moon. Based on current analyses, these absorption features appear strongest at high latitudes, but also occur in association with several fresh feldspathic craters. Interestingly, the distribution of these absorption features are not directly correlated with existing neutron spectrometer hydrogen abundance data for the sunlight surface. This may indicate that the formation and retention of hydroxyl and water is an active process largely restricted to the upper most surface. We present the detailed spectroscopic character of these absorption features in the 2700 to 3000 nm spectral region, including selected examples through all levels of measurement processing from raw data to calibrated apparent surface reflectance. In summary we show the measured strength and latitudinal distribution of the absorptions as well as selected localized occurrences in association with fresh feldspathic craters. The presence of hydroxyl and water bearing material over extensive regions of the lunar surface provides a new and unexpected source of volatiles. Options for harvesting these elements directly from the regolith may provide an alternate supply of volatiles for long term human exploration objectives.

  20. Radial Trends in IMF-sensitive Absorption Features in Two Early-type Galaxies: Evidence for Abundance-driven Gradients

    NASA Astrophysics Data System (ADS)

    McConnell, Nicholas J.; Lu, Jessica R.; Mann, Andrew W.

    2016-04-01

    Samples of early-type galaxies show a correlation between stellar velocity dispersion and the stellar initial mass function (IMF) as inferred from gravity-sensitive absorption lines in the galaxies’ central regions. To search for spatial variations in the IMF, we have observed two early-type galaxies with Keck/LRIS and measured radial gradients in the strengths of absorption features from 4000-5500 Å and 8000-10000 Å. We present spatially resolved measurements of the dwarf-sensitive spectral indices {Na} {{I}} (8190 Å) and Wing-Ford {{FeH}} (9915 Å), as well as indices for species of H, C2, CN, Mg, Ca, {{TiO}}, and Fe. Our measurements show a metallicity gradient in both objects, and Mg/Fe consistent with a shallow gradient in α-enhancement, matching widely observed trends for massive early-type galaxies. The {Na} {{I}} index and the CN1 index at 4160 Å exhibit significantly steeper gradients, with a break at r˜ 0.1 {r}{{eff}} (r˜ 300 pc). Inside this radius, {Na} {{I}} strength increases sharply toward the galaxy center, consistent with a rapid central rise in [Na/Fe]. In contrast, the ratio of the {{FeH}} to Fe index strength decreases toward the galaxy center. This behavior cannot be reproduced by a steepening IMF inside of 0.1 {r}{{eff}} if the IMF is a single power law. While gradients in the mass function above ˜ 0.4 {M}⊙ may occur, exceptional care is required to disentangle these IMF variations from the extreme variations in individual element abundances near the galaxies’ centers.

  1. Variability, absorption features, and parent body searches in "spectrally featureless" meteorite reflectance spectra: Case study - Tagish Lake

    NASA Astrophysics Data System (ADS)

    Izawa, M. R. M.; Craig, M. A.; Applin, D. M.; Sanchez, J. A.; Reddy, V.; Le Corre, L.; Mann, P.; Cloutis, E. A.

    2015-07-01

    Reflectance spectra of many asteroids and other Solar System bodies are commonly reported as "featureless". Here, we show that weak but consistently detectable absorption bands are observable in 200-2500 nm spectra of the Tagish Lake meteorite, a likely compositional and spectral analogue for low-albedo, "spectrally-featureless" asteroids. Tagish Lake presents a rare opportunity to study multiple lithologies within a single meteorite. Reflectance spectra of Tagish Lake display significant variation between different lithologies. The spectral variations are due in part to mineralogical variations between different Tagish Lake lithologies. Ultraviolet reflectance spectra (200-400 nm), few of which have been reported in the literature to date, reveal albedo and spectral ratio variations as a function of mineralogy. Similarly visible-near infrared reflectance spectra reveal variations in albedo, spectral slope, and the presence of weak absorption features that persist across different lithologies and can be attributed to various phases present in Tagish Lake. These observations demonstrate that significant spectral variability may exist between different lithologies of Tagish Lake, which may affect the interpretation of potential source body spectra. It is also important to consider the spectral variability within the meteorite before excluding compositional links between possible parent bodies in the main belt and Tagish Lake. Tagish Lake materials may also be spectral-compositional analogues for materials on the surfaces of other dark asteroids, including some that are targets of upcoming spacecraft missions. Tagish Lake has been proposed as a spectral match for 'ultra-primitive' D or P-type asteroids, and the variability reported here may be reflected in spatially or rotationally-resolved spectra of possible Tagish Lake parent bodies and source objects in the Near-Earth Asteroid population. A search for objects with spectra similar to Tagish Lake has been carried

  2. Absolute calibration and atmospheric versus mineralogic origin of absorption features in 2.0 to 2.5 micron Mars spectra obtained during 1993

    NASA Technical Reports Server (NTRS)

    Bell, James F., III; Pollack, James B.; Geballe, Thomas R.; Cruikshank, Dale P.; Freedman, Richard

    1994-01-01

    We obtained new high resolution reflectance spectra of Mars during the 1993 opposition from Mauna Kea Observatory using the UKIRT CGS4 spectrometer. Fifty spectra of 1600-2000 km surface regions and a number of standard star spectra were obtained in the 2.04 to 2.44 micron wavelength region on 4 February 1993 UT. Near-simultaneous observations of bright standard stars were used to perform terrestrial atmospheric corrections and an absolute flux calibration. Using the known magnitude of the stars and assuming blackbody continuum behavior, the flux from Mars could be derived. A radiative transfer model and the HITRAN spectral line data base were used to compute atmospheric transmission spectra for Mars and the Earth in order to simulate the contributions of these atmospheres to our observed data. Also, we examined the ATMOS solar spectrum in the near-IR to try to identify absorption features in the spectrum of the Sun that could be misinterpreted as Mars features. Eleven absorption features were detected in our Mars spectra. Our data provide no conclusive identification of the mineralogy responsible for the absorption features we detected. However, examination of terrestrial spectral libraries and previous high spectral resolution mineral studies indicates that the most likely origin of these features is either CO3(sup 2-), HCO3(-), or HSO4(-) anions in framework silicates or possibly (Fe, Mg)-OH bonds in sheet silicates.

  3. Measurement of atmospheric NO3 1. Improved removal of water vapour absorption features in the analysis for NO3

    NASA Astrophysics Data System (ADS)

    Aliwell, S. R.; Jones, R. L.

    Atmospheric measurements of the nitrate radical generally detect its absorption of visible radiation in the band near 662 nm. This band is negatively correlated with strong absorptions due to tropospheric water vapour which must therefore be fitted in the spectral analysis to reduce the spectral residual to the level at which sufficient sensitivity to NO3 can be obtained. Previously this had been fitted using a cross-section typically derived from spectra obtained just before sunset or just after sunrise which took no account of the diurnal variation in temperature and water vapour column amounts. An improved method of accounting for water vapour absorptions is presented here. When fitted together with their temperature dependence, water vapour cross-sections calculated using a line-by-line approach gave a more accurate fitting of water vapour absorptions, thus improving the analysis for NO3.

  4. Strength of mineral absorption features in the transmitted component of near-infrared reflected light - First results from RELAB. [spectrogoniometer for planetary and lunar surface composition experiments

    NASA Technical Reports Server (NTRS)

    Pieters, C. M.

    1983-01-01

    Bidirectional reflectance measurements are the only type of reflectance data available to the remote observer. For compositional interpretations, data are desired not only for identification of possible mineral components but also for modal abundance. The latter requires detailed information about the strength of absorption features. Using a new laboratory facility, the RELAB, laboratory data in the near infrared are presented that document effects of particle size, mineral mixtures, and viewing geometry for selected materials with well-developed absorption bands. The commonly observed increase in reflectance with decrease in particle size is also observed for absorption bands as well as a related decrease in absorption strength. For small particles in parts of the spectrum of maximum reflectance, however, a minor decrease in reflectance with a decrese in particle size is sometimes observed. Small particles dominate the observed characteristics of particulate surfaces, which contain a range of particle sizes. The mean optical path length (transmission through particles) of reflected radiation measured for a variety of particle sizes has an apparent upper limit of about 2 mm for particles of less than 250 microns. The typical number of particles involved in the optical path is less than 50.

  5. Lanthanides and other spectral oddities in a Centauri. Ce III, Nd III, Kr II, and broad absorption features

    NASA Astrophysics Data System (ADS)

    Cowley, C. R.; Hubrig, S.; González, J. F.

    2010-11-01

    Context. There is considerable interest in the helium variable a Cen as a bridge between helium-weak and helium-strong CP stars. Aims: We investigate Ce iii and other possible lanthanides in the spectrum the of hottest chemically peculiar (CP) star in which these elements have been found. A Kr ii line appears within a broad absorption which we suggest may be due to a high-level transition in C ii. Methods: Wavelengths and equivalent widths are measured on high-resolution UVES spectra, analyzed, and their phase-variations investigated. Results: New, robust identifications of Ce iii and Kr ii are demonstrated. Nd iii is likely present. A broad absorption near λ4619 is present at all phases of a Cen, and in some other early B stars. Conclusions: The presence of lanthanides in a Cen strengthens the view that this star is a significant link between the cooler CP stars and the hotter helium-peculiar stars. Broad absorptions in a Cen are not well explained. Based on observations collected at the European Southern Observatory, Paranal, Chile (ESO programmes 65.L-0316(A), 073.D-0504(A), and 076.B-0055(A)).

  6. FIRST ULTRAVIOLET REFLECTANCE SPECTRA OF PLUTO AND CHARON BY THE HUBBLE SPACE TELESCOPE COSMIC ORIGINS SPECTROGRAPH: DETECTION OF ABSORPTION FEATURES AND EVIDENCE FOR TEMPORAL CHANGE

    SciTech Connect

    Stern, S. A.; Spencer, J. R.; Shinn, A.; Cunningham, N. J.; Hain, M. J.

    2012-01-15

    We have observed the mid-UV spectra of both Pluto and its large satellite, Charon, at two rotational epochs using the Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS) in 2010. These are the first HST/COS measurements of Pluto and Charon. Here we describe the observations and our reduction of them, and present the albedo spectra, average mid-UV albedos, and albedo slopes we derive from these data. These data reveal evidence for a strong absorption feature in the mid-UV spectrum of Pluto; evidence for temporal change in Pluto's spectrum since the 1990s is reported, and indirect evidence for a near-UV spectral absorption on Charon is also reported.

  7. High sensitivity liquid phase measurements using broadband cavity enhanced absorption spectroscopy (BBCEAS) featuring a low cost webcam based prism spectrometer.

    PubMed

    Qu, Zhechao; Engstrom, Julia; Wong, Donald; Islam, Meez; Kaminski, Clemens F

    2013-11-01

    Cavity enhanced techniques enable high sensitivity absorption measurements in the liquid phase but are typically more complex, and much more expensive, to perform than conventional absorption methods. The latter attributes have so far prevented a wide spread use of these methods in the analytical sciences. In this study we demonstrate a novel BBCEAS instrument that is sensitive, yet simple and economical to set up and operate. We use a prism spectrometer with a low cost webcam as the detector in conjunction with an optical cavity consisting of two R = 0.99 dielectric mirrors and a white light LED source for illumination. High sensitivity liquid phase measurements were made on samples contained in 1 cm quartz cuvettes placed at normal incidence to the light beam in the optical cavity. The cavity enhancement factor (CEF) with water as the solvent was determined directly by phase shift cavity ring down spectroscopy (PS-CRDS) and also by calibration with Rhodamine 6G solutions. Both methods yielded closely matching CEF values of ~60. The minimum detectable change in absorption (αmin) was determined to be 6.5 × 10(-5) cm(-1) at 527 nm and was limited only by the 8 bit resolution of the particular webcam detector used, thus offering scope for further improvement. The instrument was used to make representative measurements on dye solutions and in the determination of nitrite concentrations in a variation of the widely used Griess Assay. Limits of detection (LOD) were ~850 pM for Rhodamine 6G and 3.7 nM for nitrite, respectively. The sensitivity of the instrument compares favourably with previous cavity based liquid phase studies whilst being achieved at a small fraction of the cost hitherto reported, thus opening the door to widespread use in the community. Further means of improving sensitivity are discussed in the paper. PMID:24049768

  8. High sensitivity liquid phase measurements using broadband cavity enhanced absorption spectroscopy (BBCEAS) featuring a low cost webcam based prism spectrometer.

    PubMed

    Qu, Zhechao; Engstrom, Julia; Wong, Donald; Islam, Meez; Kaminski, Clemens F

    2013-11-01

    Cavity enhanced techniques enable high sensitivity absorption measurements in the liquid phase but are typically more complex, and much more expensive, to perform than conventional absorption methods. The latter attributes have so far prevented a wide spread use of these methods in the analytical sciences. In this study we demonstrate a novel BBCEAS instrument that is sensitive, yet simple and economical to set up and operate. We use a prism spectrometer with a low cost webcam as the detector in conjunction with an optical cavity consisting of two R = 0.99 dielectric mirrors and a white light LED source for illumination. High sensitivity liquid phase measurements were made on samples contained in 1 cm quartz cuvettes placed at normal incidence to the light beam in the optical cavity. The cavity enhancement factor (CEF) with water as the solvent was determined directly by phase shift cavity ring down spectroscopy (PS-CRDS) and also by calibration with Rhodamine 6G solutions. Both methods yielded closely matching CEF values of ~60. The minimum detectable change in absorption (αmin) was determined to be 6.5 × 10(-5) cm(-1) at 527 nm and was limited only by the 8 bit resolution of the particular webcam detector used, thus offering scope for further improvement. The instrument was used to make representative measurements on dye solutions and in the determination of nitrite concentrations in a variation of the widely used Griess Assay. Limits of detection (LOD) were ~850 pM for Rhodamine 6G and 3.7 nM for nitrite, respectively. The sensitivity of the instrument compares favourably with previous cavity based liquid phase studies whilst being achieved at a small fraction of the cost hitherto reported, thus opening the door to widespread use in the community. Further means of improving sensitivity are discussed in the paper.

  9. L-asparagine crystals with wide gap semiconductor features: Optical absorption measurements and density functional theory computations

    SciTech Connect

    Zanatta, G.; Gottfried, C.; Silva, A. M.; Caetano, E. W. S.; Sales, F. A. M.; Freire, V. N.

    2014-03-28

    Results of optical absorption measurements are presented together with calculated structural, electronic, and optical properties for the anhydrous monoclinic L-asparagine crystal. Density functional theory (DFT) within the generalized gradient approximation (GGA) including dispersion effects (TS, Grimme) was employed to perform the calculations. The optical absorption measurements revealed that the anhydrous monoclinic L-asparagine crystal is a wide band gap material with 4.95 eV main gap energy. DFT-GGA+TS simulations, on the other hand, produced structural parameters in very good agreement with X-ray data. The lattice parameter differences Δa, Δb, Δc between theory and experiment were as small as 0.020, 0.051, and 0.022 Å, respectively. The calculated band gap energy is smaller than the experimental data by about 15%, with a 4.23 eV indirect band gap corresponding to Z → Γ and Z → β transitions. Three other indirect band gaps of 4.30 eV, 4.32 eV, and 4.36 eV are assigned to α3 → Γ, α1 → Γ, and α2 → Γ transitions, respectively. Δ-sol computations, on the other hand, predict a main band gap of 5.00 eV, just 50 meV above the experimental value. Electronic wavefunctions mainly originating from O 2p–carboxyl, C 2p–side chain, and C 2p–carboxyl orbitals contribute most significantly to the highest valence and lowest conduction energy bands, respectively. By varying the lattice parameters from their converged equilibrium values, we show that the unit cell is less stiff along the b direction than for the a and c directions. Effective mass calculations suggest that hole transport behavior is more anisotropic than electron transport, but the mass values allow for some charge mobility except along a direction perpendicular to the molecular layers of L-asparagine which form the crystal, so anhydrous monoclinic L-asparagine crystals could behave as wide gap semiconductors. Finally, the calculations point to a high degree of optical

  10. Atmospheric Profiling Combining the Features of GPS ro & Mls: Satellite to Satellite Occultations Near Water & Ozone Absorption Lines

    NASA Astrophysics Data System (ADS)

    Kursinski, E. R.; Ward, D.; Otarola, A. C.; McGhee, J.; Reed, H.; Erickson, D.

    2015-12-01

    Assessing climate models & their predictions requires observations that determine the state of the real climate system precisely and unambiguously, independently from models. For this purpose, we have been developing a new orbiting remote sensing system called the Active Temperature, Ozone & Moisture Microwave Spectrometer (ATOMMS) which is a cross between GPS RO and the Microwave Limb Sounder. ATOMMS actively probes water vapor, ozone & other absorption lines at cm & mm wavelengths in a satellite to satellite occultation geometry to simultaneously profile temperature, pressure, water vapor and ozone as well as other important constituents. Individual profiles of water vapor, temperature & pressure heights will extend from near the surface into the mesosphere with ~1%, 0.4K and 10 m precision respectively and still better accuracy, with 100 m vertical resolution. Ozone profiles will extend upward from the upper troposphere. Line of sight wind profiles will extend upwards from the mid-stratosphere. ATOMMS is a doubly differential absorption system which eliminates drift and both sees clouds and sees thru them, to deliver performance in clouds within a factor of 2 of the performance in clear skies. This all-weather sampling combined with insensitivity to surface emissivity avoids sampling biases that limit most existing satellite records. ATOMMS will profile slant liquid water in clouds & rain and as well as turbulence via scintillations ("twinkling of a star"). Using prototype ATOMMS instrumentation that we developed with funding from NSF, several ATOMMS ground field campaigns precisely measured water vapor, cloud amount, rainfall, turbulence and absorption line spectroscopy. ATOMMS's dynamic range was demonstrated as water vapor was derived to 1% precision in optical depths up to 17. We are developing high altitude aircraft to aircraft instrumentation to further demonstrate ATOMMS performance, refine spectroscopy & support future field campaigns. Our vision is a

  11. L-Asparagine crystals with wide gap semiconductor features: optical absorption measurements and density functional theory computations.

    PubMed

    Zanatta, G; Gottfried, C; Silva, A M; Caetano, E W S; Sales, F A M; Freire, V N

    2014-03-28

    Results of optical absorption measurements are presented together with calculated structural, electronic, and optical properties for the anhydrous monoclinic L-asparagine crystal. Density functional theory (DFT) within the generalized gradient approximation (GGA) including dispersion effects (TS, Grimme) was employed to perform the calculations. The optical absorption measurements revealed that the anhydrous monoclinic L-asparagine crystal is a wide band gap material with 4.95 eV main gap energy. DFT-GGA+TS simulations, on the other hand, produced structural parameters in very good agreement with X-ray data. The lattice parameter differences Δa, Δb, Δc between theory and experiment were as small as 0.020, 0.051, and 0.022 Å, respectively. The calculated band gap energy is smaller than the experimental data by about 15%, with a 4.23 eV indirect band gap corresponding to Z → Γ and Z → β transitions. Three other indirect band gaps of 4.30 eV, 4.32 eV, and 4.36 eV are assigned to α3 → Γ, α1 → Γ, and α2 → Γ transitions, respectively. Δ-sol computations, on the other hand, predict a main band gap of 5.00 eV, just 50 meV above the experimental value. Electronic wavefunctions mainly originating from O 2p-carboxyl, C 2p-side chain, and C 2p-carboxyl orbitals contribute most significantly to the highest valence and lowest conduction energy bands, respectively. By varying the lattice parameters from their converged equilibrium values, we show that the unit cell is less stiff along the b direction than for the a and c directions. Effective mass calculations suggest that hole transport behavior is more anisotropic than electron transport, but the mass values allow for some charge mobility except along a direction perpendicular to the molecular layers of L-asparagine which form the crystal, so anhydrous monoclinic L-asparagine crystals could behave as wide gap semiconductors. Finally, the calculations point to a high degree of optical

  12. Features of the absorption of 2-to 40-TeV cosmic-ray hadrons in lead

    SciTech Connect

    Sveshnikova, L. G. Yakovlev, V. I.; Turundaevskii, A. N.; Galkin, V. I.; Nazarov, S. I.; Podorozhnyi, D. M.; Popova, N. S.; Roganova, T. M.

    2006-02-15

    For the first time, experimental data on 2-to 40-TeV hadronic cascades recorded by a lead ionization calorimeter at the Tien-Shan mountain station of the Lebedev Institute of Physics (Moscow) are compared with the results of a present-day simulation based on the GEANT 3.21 code and performed with allowance for the detection procedure. The conclusion that along-flying component appears in high-energy hadronic cascades was drawn previously on the basis of these data. Some special features of the procedure for recording TeV-range hadrons in the calorimeter are considered. It is shown that the averaged hadronic cascades and various features of single cascades having energies below 10 TeV are simulated adequately by using the QGSJET + FLUKA generators of nuclear interactions, but that they are not described by using the GHEISHA generator at lower energies. Some features of the experimentally observed cascades could not be described for cascade energies above 10 TeV.

  13. Absorption features in the quasar HS 1603 + 3820 II. Distance to the absorber obtained from photoionisation modelling

    NASA Astrophysics Data System (ADS)

    Różańska, A.; Nikołajuk, M.; Czerny, B.; Dobrzycki, A.; Hryniewicz, K.; Bechtold, J.; Ebeling, H.

    2014-04-01

    We present the photoionisation modelling of the intrinsic absorber in the bright quasar HS 1603 + 3820. We constructed the broad-band spectral energy distribution using the optical/UV/X-ray observations from different instruments as inputs for the photoionisation calculations. The spectra from the Keck telescope show extremely high CIV to HI ratios, for the first absorber in system A, named A1. This value, together with high column density of CIV ion, place strong constraints on the photoionisation model. We used two photoionisation codes to derive the hydrogen number density at the cloud illuminated surface. By estimating bolometric luminosity of HS 1603 + 3820 using the typical formula for quasars, we calculated the distance to A1. We could find one photoionization solution, by assuming either a constant density cloud (which was modelled using CLOUDY), or a stratified cloud (which was modelled using TITAN), as well as the solar abundances. This model explained both the ionic column density of CIV and the high CIV to HI ratio. The location of A1 is 0.1 pc, and it is situated even closer to the nucleus than the possible location of the Broad Line Region in this object. The upper limit of the distance is sensitive to the adopted covering factor and the carbon abundance. Photoionisation modelling always prefers dense clouds with the number density n0 = 1010 - 1012 cm-3, which explains intrinsic absorption in HS 1603 + 3820. This number density is of the same order as that in the disk atmosphere at the implied distance of A1. Therefore, our results show that the disk wind that escapes from the outermost accretion disk atmosphere can build up dense absorber in quasars.

  14. Modelling the Emission And/or Absorption Features in the High Resolution Spectra of the Southern Binary System: HH Car

    NASA Astrophysics Data System (ADS)

    Koseoglu, Dogan; Bakış, Hicran

    2016-07-01

    High-resolution spectra (R=48000) of the southern close binary system, HH Car, has been analyzed with modern analysis techniques. Precise absolute parameters were derived from the simultaneous solution of the radial velocity, produced in this study and the light curves, published. According to the results of these analyses, the primary component is an O9 type main sequence star while the secondary component is a giant/subgiant star with a spectral type of B0. Hα emissions can be seen explicitly in the spectra of HH Car. These features were modelled using the absolute parameters of the components. Since components of HH Car are massive early-type stars, mass loss through stellar winds can be expected. This study revealed that the components of HH Car have stellar winds and the secondary component loses mass to the primary. Stellar winds and the gas stream between the components were modelled as a hot shell around the system. It is determined that the interaction between the winds and the gas stream leads to formation of a high temperature impact region.

  15. The soft gamma-ray spectrum of A0535+26: Detection of an absorption feature at 110 keV by OSSE

    NASA Technical Reports Server (NTRS)

    Grove, J. E.; Strickman, M. S.; Johnson, W. N.; Kurfess, J. D.; Kinzer, R. L.; Starr, C. H.; Jung, G. V.; Kendziorra, E.; Maisack, M.; Staubert, R.

    1995-01-01

    We present soft gamma-ray observations by the Oriented Scintillation Spectrometer Experiment (OSSE) on the Compton Gamma Ray Observatory (GRO) of the transient X-ray binary pulsar A0535+26. The observations were made 1994 February 8-17, immediately prior to the peak of a giant outburst. The phase averaged spectrum is complex and cannot be described by a single-component model. We find that structure in the spectrum above 100 keV can best be modeled by an absorption feature near 110 keV, which we interepret as the signature of cyclotron resonant scattering. Because of OSSE's 45 keV threshold, we are unable to make a definitive statement on the presence of a 55 keV absorption line; however, we can conclude that if this line does exist, it must have a smaller optical depth than the line at 110 keV. A first harmonic (=fundamental) cyclotron resonance at 110 keV corresponds to a magnetic field strength at the surface of the neutron star of approximately 1 x 10(exp 13) G (approximately 5 x 10(exp 12) G if the first harmonic is at 55 keV).

  16. Clear cell chondrosarcomas arising from rare sites.

    PubMed

    Ogose, A; Motoyama, T; Hotta, T; Emura, I; Inoue, Y; Morita, T; Watanabe, H

    1995-09-01

    Three cases are reported of clear cell chondrosarcoma arising from unusual sites: talus, rib and vertebra. Radiographically, two tumors showed osteolytic features and the vertebral tumor showed osteoplastic change. Histologically, all tumors consisted of clear cells that had a centrally placed nucleus surrounded by clear cytoplasm, osteoclast-like giant cells, areas of conventional chondrosarcoma, and various amounts of reactive bone. The tumor in the talus was initially diagnosed as benign chondroblastoma, but it recurred. The rib tumor showed marked cystic formation stimulating aneurysmal bone cyst. The osteoplastic radiographic feature in vertebral tumor was considered to be due to the abundant bone formation. PMID:8548042

  17. Adenocarcinoma arising in a gastrocystoplasty

    PubMed Central

    Balachandra, B; Swanson, P E; Upton, M P; Yeh, M M

    2007-01-01

    Gastrocystoplasty is a form of surgical bladder augmentation or neobladder used to restore bladder capacity and compliance in children and in patients with neurogenic bladder. Other forms of bladder augmentation include ileocystoplasty and colocystoplasty. Reported complications of gastrocystoplasty include post‐operative bleeding, haematuria, stricture, metabolic alkalosis and rupture of the gastric segment. There are reports of adenocarcinomas arising in the setting of ileocystoplasty and colocystoplasty. However, the first case of adenocarcinoma arising in the setting of a gastrocystoplasty is reported. PMID:17213351

  18. Adenocarcinoma arising in a gastrocystoplasty.

    PubMed

    Balachandra, B; Swanson, P E; Upton, M P; Yeh, M M

    2007-01-01

    Gastrocystoplasty is a form of surgical bladder augmentation or neobladder used to restore bladder capacity and compliance in children and in patients with neurogenic bladder. Other forms of bladder augmentation include ileocystoplasty and colocystoplasty. Reported complications of gastrocystoplasty include post-operative bleeding, haematuria, stricture, metabolic alkalosis and rupture of the gastric segment. There are reports of adenocarcinomas arising in the setting of ileocystoplasty and colocystoplasty. However, the first case of adenocarcinoma arising in the setting of a gastrocystoplasty is reported.

  19. Schwannoma arising from intramasseteric region.

    PubMed

    He, Yue; Fu, Hong Hai; He, Jie; Zhu, Han Guang; Zhang, Zhi Yuan

    2010-11-01

    Schwannoma in the head and neck is usually arising in the parapharyngeal space, but intramasseteric schwannoma is very rare. We report a schwannoma arising from masseter muscle in a middle-aged woman, who presented with a history of a painless right cheek mass for 3 years. Computed tomography scan suggested that the mass was located within the masseter muscle. Fine-needle aspiration was performed and showed spindle neoplastic cells, which were suspected to be of mesenchymal tissue origin. The mass was completely resected under general anesthesia. It was a well-circumscribed and lobulated mass, 4 × 3 × 2 cm in size. Histological examination gave the diagnosis of schwannoma, which was also confirmed by immunohistochemical stainings for S-100 and vimentin. Neurologic sequelae and recurrence were not found at 2 years after surgery. PMID:21119484

  20. Intraosseous verrucous carcinoma arising from an orthokeratinized odontogenic keratocyst: A report of a rarest entity

    PubMed Central

    Kamarthi, Nagaraju; Palakshappa, Suhasini Gotur; Wadhwan, Vijay; Mohan, Raviprakash Sasankoti

    2016-01-01

    Intraosseous verrucous carcinomas (VCs) arising from odontogenic cysts are a rare entity. An unusual case of a VC arising from the orthokeratinized odontogenic cyst is described for the first time. The microscopic features of the lesion are presented. PMID:27630514

  1. Intraosseous verrucous carcinoma arising from an orthokeratinized odontogenic keratocyst: A report of a rarest entity.

    PubMed

    Kamarthi, Nagaraju; Palakshappa, Suhasini Gotur; Wadhwan, Vijay; Mohan, Raviprakash Sasankoti

    2016-01-01

    Intraosseous verrucous carcinomas (VCs) arising from odontogenic cysts are a rare entity. An unusual case of a VC arising from the orthokeratinized odontogenic cyst is described for the first time. The microscopic features of the lesion are presented. PMID:27630514

  2. Leiomyosarcoma arising in a lipoleiomyoma.

    PubMed

    Scurry, J; Hack, M

    1990-12-01

    A leiomyosarcoma arising in a uterine lipoleiomyoma is described in a 70-year-old woman. The tumor measured 11 cm and was located in the corpus uteri. It was composed of a mixture of firm, pale tan, whorled tissue and soft, white or hemorrhagic areas. Histologically, the firm tissue was a mixture of bland smooth muscle, fat and fibrous tissue, whereas the soft areas showed a malignant spindle cell tumor with smooth muscle differentiation. Pure sarcoma similar to the malignant portion of the lipoleiomyoma had metastasized to the vaginal wall.

  3. Neutral atomic-carbon quasar absorption-line systems at z> 1.5. Sample selection, H i content, reddening, and 2175 Å extinction feature

    NASA Astrophysics Data System (ADS)

    Ledoux, C.; Noterdaeme, P.; Petitjean, P.; Srianand, R.

    2015-08-01

    We present the results of a search for cold gas at high redshift along quasar lines of sight carried out without any a priori assumption on the neutral atomic-hydrogen content of the absorption-line systems. To do this, we systematically looked for neutral-carbon (C i) λλ1560, 1656 transition lines in 41 696 low-resolution quasar spectra (1.5 < zem < 4.46) from the SDSS-II - Data Release 7 - database. C i absorption lines should indeed probe the shielded gas in the neutral interstellar medium of galaxies more efficiently than traditional tracers such as neutral atomic-hydrogen (H i) damped Lyman-α (DLA) and/or Mg ii systems. We built up a sample of 66 C i absorbers with redshifts in the range 1.5 < z < 3.1 and rest-frame equivalent widths 0.1 21 (atoms cm-2) compared to systematic DLA surveys. Whilst the dust content

  4. Melanoma arising after imiquimod use.

    PubMed

    Paul, Sharad P

    2014-01-01

    Imiquimod belongs to the class of 1H-imidazo-[4,5-c]quinolones-drugs originally developed as nucleoside analogues with the aim of finding new potential antiviral agents (Harrison et al., 1988). Indeed, Imiquimod was first released as treatment for genital warts before its actions against skin cancer were studied. Imiquimod is a relatively small sized molecule (Mr = 240.3) and is hydrophobic, allowing it to penetrate the skin epidermal barrier and therefore making it suitable for topical formulations (Gerster et al., 2005). Imiquimod has shown itself effective against skin cancers and precancerous lesions, especially basal cell cancers and actinic keratosis (Salasche et al., 2002, Beutner et al., 1999). There have been reports of Imiquimod being used as topical treatment against cutaneous metastases of melanoma and some authors have reported its use as first-line therapy against melanoma in situ (Smyth et al., 2011, Gagnon, 2011). We report a case of an invasive malignant melanoma arising de novo at the specific site of application of Imiquimod (Aldara cream 5%) for a biopsy-proven superficial BCC. Therefore while Imiquimod has added to our topical armamentarium against skin cancer, care must be exercised in prescribing this treatment and it is especially important to follow up patients regularly. PMID:25431597

  5. Active Galactic Nuclei Probed by QSO Absorption Lines

    NASA Astrophysics Data System (ADS)

    Misawa, Toru

    2007-07-01

    Quasars are the extremely bright nuclei found in about 10% of galaxies. A variety of absorption features (known collectively as quasar absorption lines) are detected in the rest-frame UV spectra of these objects. While absorption lines that have very broad widths originate in gas that is probably physocally related to the quasars, narrow absorption lines (NALs) were thought to arise in galaxies and/or in the intter-alacttic medium between the quasars and us. Using high-resolution spectra of quasars, it is found that a substantial fraction of NALs arise in gas in the immediate vicinity of the quasars. A dramatically variable, moderately-broad absorption line in the spectrum of the quasar HS 1603+3820l is also found. The variability of this line is monitored in a campaign with Subaru telescope. These observational results are compared to models for outflows from the quasars, specifically, models for accretion disk winds and evaporating obscuring tori. It is quite important to determine the mechanism of outflow because of its cosmological implications. The outflow could expel angular momentum from the accretion disk and enable quasars to accrete and shine. In addition, the outflow may also regulate star formation in the early stages of the assembly of the host galaxy and enrich the interstellar and intergalactic medium with metals.

  6. CAN GROUND-BASED TELESCOPES DETECT THE OXYGEN 1.27 {mu}m ABSORPTION FEATURE AS A BIOMARKER IN EXOPLANETS?

    SciTech Connect

    Kawahara, Hajime; Matsuo, Taro; Takami, Michihiro; Fujii, Yuka; Kotani, Takayuki; Tamura, Motohide; Murakami, Naoshi; Guyon, Olivier

    2012-10-10

    The oxygen absorption line imprinted in the scattered light from Earth-like planets has been considered the most promising metabolic biomarker for exolife. We examine the feasibility of the detection of the 1.27 {mu}m oxygen band from habitable exoplanets, in particular, around late-type stars observed with a future instrument on a 30 m class ground-based telescope. We analyzed the night airglow around 1.27 {mu}m with the IRCS/echelle spectrometer on Subaru and found that the strong telluric emission from atmospheric oxygen molecules declines by an order of magnitude by midnight. By compiling nearby star catalogs combined with the sky background model, we estimate the detectability of the oxygen absorption band from an Earth twin, if it exists, around nearby stars. We find that the most dominant source of photon noise for the oxygen 1.27 {mu}m band detection comes from the night airglow if the contribution of the stellar point-spread function (PSF) halo is suppressed enough to detect the planet. We conclude that the future detectors, for which the detection contrast is limited by photon noise, can detect the oxygen 1.27 {mu}m absorption band of Earth twins for {approx}50 candidates of the late-type star. This paper demonstrates the importance of deploying a small inner working angle as an efficient coronagraph and extreme adaptive optics on extremely large telescopes, and clearly shows that doing so will enable the study of potentially habitable planets.

  7. CONFIRMATION OF ENHANCED DWARF-SENSITIVE ABSORPTION FEATURES IN THE SPECTRA OF MASSIVE ELLIPTICAL GALAXIES: FURTHER EVIDENCE FOR A NON-UNIVERSAL INITIAL MASS FUNCTION

    SciTech Connect

    Van Dokkum, Pieter G.; Conroy, Charlie

    2011-07-01

    We recently found that massive cluster elliptical galaxies have strong Na I {lambda}8183, 8195 and FeH {lambda}9916 Wing-Ford band absorption, indicating the presence of a very large population of stars with masses {approx}< 0.3 M{sub sun}. Here we test this result by comparing the elliptical galaxy spectra to those of luminous globular clusters associated with M31. These globular clusters have similar metallicities, abundance ratios, and ages as massive elliptical galaxies but their low dynamical mass-to-light ratios rule out steep stellar initial mass functions (IMFs). From high-quality Keck spectra we find that the dwarf-sensitive absorption lines in globular clusters are significantly weaker than in elliptical galaxies and consistent with normal IMFs. The differences in the Na I and Wing-Ford indices are 0.027 {+-} 0.007 mag and 0.017 {+-} 0.006 mag, respectively. We directly compare the two classes of objects by subtracting the averaged globular cluster spectrum from the averaged elliptical galaxy spectrum. The difference spectrum is well fit by the difference between a stellar population synthesis model with a bottom-heavy IMF and one with a bottom-light IMF. We speculate that the slope of the IMF may vary with velocity dispersion, although it is not yet clear what physical mechanism would be responsible for such a relation.

  8. Four Different Tumors Arising in a Nevus Sebaceous.

    PubMed

    Namiki, Takeshi; Miura, Keiko; Ueno, Makiko; Arima, Yumi; Nishizawa, Aya; Yokozeki, Hiroo

    2016-01-01

    Nevus sebaceous is known by its association with one or more secondary tumors, but more than three multiple tumors arising from a nevus sebaceous is extremely rare. A 67-year-old female presented with a light brown plaque on the back of her head that contained a dome-shaped black node and an erosive lesion. Histopathological examination showed atypical basaloid cells in the black node. At the periphery of that node, structures resembling follicular germs extruded from interlacing cords in the upper portion and tumor nests with sebocytes were in the lower portion. In the erosive lesion, papillated structures with an apocrine epithelium were observed. In the light brown plaque, enlargement of sebaceous lobules was noted. From those histopathological features, a diagnosis of syringocystadenoma papilliferum, sebaceoma, trichoblastoma and basal cell carcinoma arising from a nevus sebaceous was made. We discuss the rarity of multiple tumors arising from a nevus sebaceous. PMID:27194974

  9. Four Different Tumors Arising in a Nevus Sebaceous

    PubMed Central

    Namiki, Takeshi; Miura, Keiko; Ueno, Makiko; Arima, Yumi; Nishizawa, Aya; Yokozeki, Hiroo

    2016-01-01

    Nevus sebaceous is known by its association with one or more secondary tumors, but more than three multiple tumors arising from a nevus sebaceous is extremely rare. A 67-year-old female presented with a light brown plaque on the back of her head that contained a dome-shaped black node and an erosive lesion. Histopathological examination showed atypical basaloid cells in the black node. At the periphery of that node, structures resembling follicular germs extruded from interlacing cords in the upper portion and tumor nests with sebocytes were in the lower portion. In the erosive lesion, papillated structures with an apocrine epithelium were observed. In the light brown plaque, enlargement of sebaceous lobules was noted. From those histopathological features, a diagnosis of syringocystadenoma papilliferum, sebaceoma, trichoblastoma and basal cell carcinoma arising from a nevus sebaceous was made. We discuss the rarity of multiple tumors arising from a nevus sebaceous. PMID:27194974

  10. Variation of the 3-μm absorption feature on Mars: observations over eastern Valles Marineris by the mariner 6 infrared spectrometer

    USGS Publications Warehouse

    Calvin, Wendy M.

    1997-01-01

    A new approach for calibration of the shortest wavelength channel (1.8 to 6.0 μm) of the Mariner 6 infrared spectrometer was derived. This calibration provides a new description of the instrument response function from 1.8 to 3.7 μm and accounts for the thermal contribution to the signal at longer wavelengths. This allows the two segments from 1.8 to 6 μm to be merged into a single spectrum. The broad water of hydration absorption spans these two segments and is examined in these merged spectra using a method of band integration. Unlike previous analyses which rely on ratios at two wavelengths, the integration method can assess the band strength independently from the albedo in the near infrared. Spectra taken over the eastern end of the Valles Marineris are examined for variations of the band-integrated value, and three distinct clusters are found. Within the estimated uncertainty, two clusters (both low and high albedo) have approximately the same integrated band depth. The third cluster (medium albedo) has an integrated band depth about 10% higher. This difference cannot be systematically attributed to either surface or atmospheric parameters and suggests variation in the amount of water either chemically or physically bound in surface materials. Approximately one-half of the high integrated band depth cluster is associated with chaotic terrain at the source of outflow channels, the other half occurs over lower inertia plains adjacent to chasmata. This suggests both surface physical properties and mineralogy as well as water in exchange with the atmosphere contribute to the 3-μm bound water absorption.

  11. Ultrafast absorption difference spectra of the Fenna-Matthews-Olson protein at 19 K: experiment and simulations.

    PubMed

    Buck, D R; Savikhin, S; Struve, W S

    1997-01-01

    We describe simulations of absorption difference spectra in strongly coupled photosynthetic antennas. In the presence of large resonance couplings, distinctive features arise from excited-state absorption transitions between one- and two-exciton levels. We first outline the theory for the heterodimer and for the general N-pigment system, and we demonstrate the transition between the strong and weak coupling regimes. The theory is applied to Fenna-Matthews-Olson (FMO) bacteriochlorophyll a protein trimers from the green photosynthetic bacterium Prosthecochloris aestuarii and then compared with experimental low-temperature absorption difference spectra of FMO trimers from the green bacterium Chlorobium tepidum.

  12. Canalicular adenoma arising in the esophagus.

    PubMed

    Grimm, Erin E; Rulyak, Stephen J; Sekijima, John H; Yeh, Matthew M

    2007-10-01

    Canalicular adenomas are benign neoplasms that arise from salivary glands and often present as painless enlarging nodules. They have a predilection for upper lip but can be found throughout the oropharynx. To our knowledge, canalicular adenoma arising in the esophagus has never been described in the English literature. Here we report a canalicular adenoma occurring in the esophagus.

  13. Angiosarcoma arising in an ovarian fibroma: a case report.

    PubMed

    Cambruzzi, Eduardo; Pegas, Karla Lais; Milani, Daniel Marini; Cruz, Ricardo Pedrini; Guerra, Enilde Heloena; Ferrari, Márcio Balbinotti

    2010-01-01

    Primary ovarian angiosarcoma is a very rare gynaecological sarcoma, with poor prognosis. These tumors are though to arise from carcinosarcomas, teratomas, or the ovarian vasculature and occur at any age. There are only a few cases reported in the international literature, most commonly associated to surface epithelial-stromal or germ cell tumours. Herein, the authors report the clinicopathologic features of an angiosarcoma arising in an ovarian fibroma. A 65-year-old patient was admitted with a palpable mass in the hypogastrium. Grossly, the removed ovary was completely replaced by a solid tumor mass. On histological analysis, the lesion revealed the typical histological features of angiosarcoma with sinusoidal patterns and anaplastic cells, admixed with spindle-shaped cells arranged in fascicles or in a storiform pattern, compatible with a fibroma. The vascular component was strongly immunopositive for CD31 and CD34. The patient was submitted to chemotherapy, and she was alive for two months after surgical proceedings. PMID:21151524

  14. Myofibroblastoma arising in mammary hamartoma: a case report.

    PubMed

    Uchôa, Diego M; Cruz, Dênnis Baroni; Schaefer, Pedro Guilherme; Pêgas, Karla Laís; Cambruzzi, Eduardo

    2010-01-01

    Myofibroblastoma (MFB) is a rare mesenchymal tumor arising in breast's soft tissue with a great variety of microscopic features that can be mistaken with a wide variety of biphasic lesions. The authors report a rare case of myofibroblastoma of the breast arising in a mammary hamartoma (MH), present a review of the clinicopathological features of these lesions, and make some diagnostic considerations. The tumour consisted of a well-circumscribed nodule. MFB component comprised about fifty percent of the lesion and was made up of bipolar spindle cells arranged in fascicular clusters separated by bands of hyalinized collagen. There were fat cells and several residual hamartoma glands intermingled and distorted in MFB area. MFB component was positive for Desmin, CD34, bcl-2, and Calponin. To the best of our knowledge, MFB has not been reported in MH, neither has any of the reports described mammary glands joined within MFB. PMID:21151720

  15. Nasal solitary fibrous tumor arising from the anterior cranial fossa.

    PubMed

    Hicks, David L; Moe, Kris S

    2004-11-01

    The solitary fibrous tumor (SFT) is a mesenchymal, spindle cell neoplasm that was originally found in pleural tissue. Recently, however, numerous extrapleural sites have been discovered, including the nasal cavity. We present the 15th case of a nasal SFT, and the first such tumor to arise from the cribriform plate and extend into the anterior cranial fossa. In addition to highlighting the aggressive nature of this tumor, we review its clinical features and the diagnostic difficulties posed by SFT.

  16. Io's Non-SO2 Spectral Features

    NASA Astrophysics Data System (ADS)

    Smythe, W. D.; Soderblom, L. A.; Nelson, R. M.

    2003-04-01

    Introduction: Several absorptions have been identified in the Galileo NIMS spectra of Io that are not related to SO_2. [1,2]. These absorptions have band centers at 2.97, 3.15, 3.85, and 3.91 microns. There are also broad absorptions in the regions 1-1.3 and 3-3.4 microns. "Patterning" noise in wavelength registration, arising from the pushbroom imaging and grating motion of the NIMS instrument have previously inhibited reliable mapping of weak absorptions. Recent improvements in techniques to remove the coherent pattern noise from the NIMS dataset have been made by Soderblom. This greatly improves the signal to noise ratio and enables mapping of weak spectral signatures such as the 3.15 micron absorption on Io. The 3.15μ feature: The 3.15μ feature is a very weak band having an apparent band depth of less than 4% of the continuum - in contrast to many of the SO_2 features, which have apparent band depths ranging from 15-70%. The 3.15μ feature is reasonably ubiquitous on the surface of Io so it was seen in global average spectra obtained early in the Galileo mission [2]. The feature has not been identified but has been attributed variously to H_2S, H_2O, or OH stretch [2,3]. A map of this feature shows a variety of correlations. The feature is strongly present at lower latitudes, which suggests that it may be associated with a material less volatile than SO_2. However the absorption does appear above 30 degrees (north and south), suggesting its presence in not strictly a thermal issue. It is interesting that the absorption moves north of the equator above Pele apparently avoiding Pele's large plume deposit, is not present at Culann, yet covers Prometheus completely. The distribution at Prometheus suggests that the material leading to the 3.15μ absorption may be associated with the Prometheus SO_2 reservoir - but it is difficult to reconcile that with the behavior of the absorption about Pele and Culann. There is a reasonably good correlation with visibly white

  17. ARISE: American renaissance in science education

    SciTech Connect

    1998-09-14

    The national standards and state derivatives must be reinforced by models of curricular reform. In this paper, ARISE presents one model based on a set of principles--coherence, integration of the sciences, movement from concrete ideas to abstract ones, inquiry, connection and application, sequencing that is responsive to how people learn.

  18. Epidermoid carcinoma arising in Warthin's tumor.

    PubMed

    Bolat, Filiz; Kayaselcuk, Fazilet; Erkan, Alper Nabi; Cagici, Can Alper; Bal, Nebil; Tuncer, Ilhan

    2004-01-01

    Warthin's tumor is a well-defined salivary gland neoplasm consisting of benign epithelial and lymphoid components. However, malignant transformation is extremely rare and the differential diagnosis of metastasis from an epidermoid carcinoma in Warthin's tumor is important. We present a case with epidermoid carcinoma arising in Warthin's tumor of parotid gland in a 48-year-old woman, and differential diagnosis is discussed.

  19. New challenges of the ARISE project

    NASA Astrophysics Data System (ADS)

    Blanc, Elisabeth

    2015-04-01

    It has been robustly demonstrated that variations in the circulation of the middle atmosphere influence weather and climate throughout the troposphere all the way to the Earth's surface. A key part of the coupling between the troposphere and stratosphere occurs through the propagation and breaking of planetary-scale Rossby waves and gravity waves. Limited observation of the middle atmosphere and these waves in particular limits the ability to faithfully reproduce the dynamics of the middle atmosphere in numerical weather prediction and climate models. The ARISE project combines for the first time international networks with complementary technologies such as infrasound, lidar and airglow. This joint network provided advanced data products that started to be used as benchmarks for weather forecast models. The ARISE network also allows enhanced and detailed monitoring of other extreme events in the Earth system such as erupting volcanoes, magnetic storms, tornadoes and tropical thunderstorms. In order to improve the ability of the network to monitor atmospheric dynamics, ARISE proposes to extend i) the existing network coverage in Africa and the high latitudes, ii) the altitude range in the stratosphere and mesosphere, iii) the observation duration using routine observation modes, and to use complementary existing infrastructures and innovative instrumentations. Data will be collected over the long term to improve weather forecasting to monthly or seasonal timescales, to monitor atmospheric extreme events and climate change. ARISE focuses on the link between models and observations for future assimilation of data by operational weather forecasting models. Among the applications, ARISE2 proposes infrasound remote volcano monitoring to provide notifications to civil aviation.

  20. Ameloblastic Fibrosarcoma Arising in the Maxilla

    PubMed Central

    Pillay, Rachael R.; Bilski, Arthur; Batstone, Martin

    2016-01-01

    Background: Ameloblastic fibrosarcoma (AFS) is a rare odontogenic neoplasm of the jaw that usually arises de novo or through a malignant change in the mesenchymal component of a preexisting or recurrent benign fibroma. The majority of AFS cases reported in the literature arise in the mandible. Case Report: A 35-year-old male presented with an asymptomatic left maxillary mass that on imaging was found to be effacing most of his maxillary sinus. He underwent a left maxillectomy with free-flap reconstruction and adjuvant radiotherapy to the tumor bed. Conclusion: Wide local excision remains the treatment of choice for AFS, given the poor survival rates of patients with recurrent disease. However, long-term studies and follow-up are needed to elucidate the role of adjuvant therapies in the primary treatment of AFS. PMID:27303223

  1. Irregular activity arises as a natural consequence of synaptic inhibition

    SciTech Connect

    Terman, D.; Rubin, J. E.; Diekman, C. O.

    2013-12-15

    Irregular neuronal activity is observed in a variety of brain regions and states. This work illustrates a novel mechanism by which irregular activity naturally emerges in two-cell neuronal networks featuring coupling by synaptic inhibition. We introduce a one-dimensional map that captures the irregular activity occurring in our simulations of conductance-based differential equations and mathematically analyze the instability of fixed points corresponding to synchronous and antiphase spiking for this map. We find that the irregular solutions that arise exhibit expansion, contraction, and folding in phase space, as expected in chaotic dynamics. Our analysis shows that these features are produced from the interplay of synaptic inhibition with sodium, potassium, and leak currents in a conductance-based framework and provides precise conditions on parameters that ensure that irregular activity will occur. In particular, the temporal details of spiking dynamics must be present for a model to exhibit this irregularity mechanism and must be considered analytically to capture these effects.

  2. Origins of optical absorption characteristics of Cu(2+) complexes in aqueous solutions.

    PubMed

    Qiu, S Roger; Wood, Brandon C; Ehrmann, Paul R; Demos, Stavros G; Miller, Philip E; Schaffers, Kathleen I; Suratwala, Tayyab I; Brow, Richard K

    2015-07-15

    Many transition metal complexes exhibit infrared or visible optical absorption arising from d-d transitions that are the key to functionality in technological applications and biological processes. The observed spectral characteristics of the absorption spectra depend on several underlying physical parameters whose relative contributions are still not fully understood. Although conventional arguments based on ligand-field theory can be invoked to rationalize the peak absorption energy, they cannot describe the detailed features of the observed spectral profile such as the spectral width and shape, or unexpected correlations between the oscillator strength and absorption peak position. Here, we combine experimental observations with first-principles simulations to investigate origins of the absorption spectral profile in model systems of aqueous Cu(2+) ions with Cl(-), Br(-), NO2(-) and CH3CO2(-) ligands. The ligand identity and concentration, fine structure in the electronic d-orbitals of Cu(2+), complex geometry, and solvation environment are all found to play key roles in determining the spectral profile. Moreover, similar physiochemical origins of these factors lead to interesting and unexpected correlations in spectral features. The results provide important insights into the underlying mechanisms of the observed spectral features and offer a framework for advancing the ability of theoretical models to predict and interpret the behavior of such systems. PMID:26059193

  3. Ground-state features in the THz spectra of molecular clusters of β-HMX.

    PubMed

    Huang, Lulu; Shabaev, Andrew; Lambrakos, Samuel G; Massa, Lou

    2012-10-01

    We present calculations of absorption spectra arising from molecular vibrations at THz frequencies for molecular clusters of the explosive HMX using density functional theory (DFT). The features of these spectra can be shown to follow from the coupling of vibrational modes. In particular, the coupling among ground-state vibrational modes provides a reasonable molecular-level interpretation of spectral features associated with the vibrational modes of molecular clusters. THz excitation from the ground state is associated with frequencies that characteristically perturb molecular electronic states, in contrast to frequencies, which are usually substantially above the mid-infrared (mid-IR) range, that can induce appreciable electronic-state transition. Owing to this characteristic of THz excitation, one is able to make a direct association between local oscillations about ground-state minima of molecules, either isolated or comprising a cluster, and THz absorption spectra. The DFT software program GAUSSIAN was used for the calculations of the absorption spectra presented here.

  4. Kapteyn series arising in radiation problems

    NASA Astrophysics Data System (ADS)

    Lerche, I.; Tautz, R. C.

    2008-01-01

    In discussing radiation from multiple point charges or magnetic dipoles, moving in circles or ellipses, a variety of Kapteyn series of the second kind arises. Some of the series have been known in closed form for a hundred years or more, others appear not to be available to analytic persuasion. This paper shows how 12 such generic series can be developed to produce either closed analytic expressions or integrals that are not analytically tractable. In addition, the method presented here may be of benefit when one has other Kapteyn series of the second kind to consider, thereby providing an additional reason to consider such series anew.

  5. Boundary estimation problems arising in thermal tomography

    NASA Technical Reports Server (NTRS)

    Banks, H. T.; Kojima, Fumio; Winfree, W. P.

    1989-01-01

    Problems on the identification of two-dimensional spatial domains arising in the detection and characterization of structural flaws in materials are considered. For a thermal diffusion system with external boundary input, observations of the temperature on the surface are used in a output least squares approach. Parameter estimation techniques based on the method of mappings are discussed and approximation schemes are developed based on a finite element Galerkin approach. Theoretical convergence results for computational techniques are given and the results are applied to experimental data for the identification of flaws in the thermal testing of materials.

  6. Eccrine Poroma Arising within Nevus Sebaceous

    PubMed Central

    Girdwichai, Natnicha; Chanprapaph, Kumutnart; Vachiramon, Vasanop

    2016-01-01

    Nevus sebaceous is a congenital, benign hamartomatous lesion, characterized by a yellowish to skin-colored, hairless, verrucous plaque on the head and neck region. In later life, a secondary tumor, either benign or malignant, can develop within nevus sebaceous. Eccrine poroma developing on nevus sebaceous is extremely rare. There are few case reports of eccrine poroma developing within nevus sebaceous. We report a case of a 30-year-old female who presented with a congenital, hairless, verrucous, yellowish lesion on the scalp and an erythematous nodule arising within the yellowish lesion for 8 months. Her clinical presentation and histopathological findings were compatible with nevus sebaceous and eccrine poroma. PMID:27194975

  7. Solitary fibrous tumor arising in gastric serosa.

    PubMed

    Lee, Won-Ae; Lee, Mi-Kyung; Jeen, Yoon Mi; Kie, Jeong-Hae; Chung, Jae-Joon; Yun, Seong Hyeon

    2004-06-01

    The solitary fibrous tumor (SFT) of peritoneum, especially arising in gastric serosa, is extremely rare. A case of SFT arising in gastric serosa of a 70-year-old man is reported. On abdominal computed tomography scan, an approximate 8.0 x 5.3 cm-sized solid mass with multiple nodular calcifications was noted in the omentomesentery of right upper abdomen, which was abutting to the gastric antral wall. At laparotomy the tumor was tightly attached to the gastric serosa and was completely excised by wedge resection of the stomach. The cut surfaces of the tumor were pale brown to pale yellow, firm, with multifocal yellowish, gritty, stony-hard nodules and cystic changes. Microscopically, the tumor was composed of mildly cellular benign-appearing spindle-shaped cells and bands of hyalinized collagen in varying proportions. The tumor revealed predominantly sclerosing pattern with extensive hyalinized fibrosis and multifocal dystrophic calcifications. The tumor was mainly located at the gastric serosa and subserosa, and its growth pattern was expansile with entrapping of muscularis propria and submucosa in the periphery of the tumor. By immunohistochemistry, the tumor cells were diffusely positive for CD34 and vimentin but negative for cytokeratin, desmin, smooth muscle actin, CD99 and c-kit. Although its occurrence is rare, SFT should be considered in the differential diagnosis of mesenchymal tumors of the stomach.

  8. Glioblastoma arising within a mediastinal mature teratoma.

    PubMed

    Liu, Liping; Jentoft, Mark E; Boland, Jennifer M

    2016-10-01

    Herein we present the case of a 42-year-old man who presented with an anterior mediastinal mass, which was found to represent a mature teratoma. Within it, there was a secondary somatic malignant glial neoplasm with mitotic activity and necrosis, compatible with glioblastoma. He experienced early local recurrence and lymph node metastasis, but is alive and well 3 1/2 years after diagnosis. Neither the teratoma nor the glioblastoma components had abnormalities of chromosome 12, which may implicate that this teratoma was more closely related to those arising along the midline of infants and children (type I germ cell tumor) than to the typically malignant testicular examples, which often contain mixed germ cell elements (type II germ cell tumor). PMID:27327191

  9. Melanotic neuroectodermal tumor of infancy arising in the temporal bone.

    PubMed

    Zhang, Jian-guo; Zhao, Rui-jiao; Kong, Ling-fei

    2015-04-01

    Melanotic neuroectodermal tumor of infancy is a rare melanin-containing neoplasm with locally aggressive and rapid expansile growth, usually involving the maxilla, skull, and mandible of early infancy. Radical surgery is critical for a long-term outcome. We present a case of 14-month-old girl with rapid-growing subcutaneous mass arising in the right temporal bone and extending intracranially on computed tomographic scan. Radical surgery was performed. A brownish-black tumor composed of large pigmented epithelioid cells, positive for cytokeratins and HMB-45, and nests of small neuroblast-like cells positive for neuron-specific enolase and synaptophysin, was diagnosed as melanotic neuroectodermal tumor of infancy. The patient remained well without evidence of recurrence for 1 year after surgery. Clinicopathological features, management alternatives and outcome were discussed.

  10. [Chemical hazards arising from shale gas extraction].

    PubMed

    Pakulska, Daria

    2015-01-01

    The development of the shale industry is gaining momentum and hence the analysis of chemical hazards to the environment and health of the local population is extreiely timely and important. Chemical hazards are created during the exploitation of all minerals, but in the case of shale gas production, there is much more uncertainty as regards to the effects of new technologies application. American experience suggests the increasing risk of environmental contamination, mainly groundwater. The greatest, concern is the incomplete knowledge of the composition of fluids used for fracturing shale rock and unpredictability of long-term effects of hydraulic fracturing for the environment and health of residents. High population density in the old continent causes the problem of chemical hazards which is much larger than in the USA. Despite the growing public discontent data on this subject are limited. First of all, there is no epidemiological studies to assess the relationship between risk factors, such as air and water pollution, and health effects in populations living in close proximity to gas wells. The aim of this article is to identify and discuss existing concepts on the sources of environmental contamination, an indication of the environment elements under pressure and potential health risks arising from shale gas extraction.

  11. An organism arises from every nucleus.

    PubMed

    Keklikoglu, Nurullah

    2009-01-01

    The fact that, cloning using somatic cell nuclear transfer (SCNT) method has been performed, opened new horizons for cloning, and changed the way of our understanding and approach to cell and nucleus. The progress in cloning technology, brought the anticipation of the ability to clone an organism from each somatic cell nucleus. Therefore, the 'Cell Theory' is about to take the additional statement as "An organism arises from every nucleus". The development of gene targeting procedures which can be applied with SCNT, showed us that it may be possible to obtain different versions of the original genetic constitution of a cell. Because of this opportunity which is provided by SCNT, in reproductive cloning, it would be possible to clone enhanced organisms which can adapt to different environmental conditions and survive. Furthermore, regaining the genetic characteristics of ancestors or reverse herediter variations would be possible. On the other hand, in therapeutic cloning, more precise and easily obtainable alternatives for cell replacement therapy could be presented. However, while producing healthier or different organisms from a nucleus, it is hard to foresee the side effects influencing natural processes in long term is rather difficult.

  12. [Chemical hazards arising from shale gas extraction].

    PubMed

    Pakulska, Daria

    2015-01-01

    The development of the shale industry is gaining momentum and hence the analysis of chemical hazards to the environment and health of the local population is extreiely timely and important. Chemical hazards are created during the exploitation of all minerals, but in the case of shale gas production, there is much more uncertainty as regards to the effects of new technologies application. American experience suggests the increasing risk of environmental contamination, mainly groundwater. The greatest, concern is the incomplete knowledge of the composition of fluids used for fracturing shale rock and unpredictability of long-term effects of hydraulic fracturing for the environment and health of residents. High population density in the old continent causes the problem of chemical hazards which is much larger than in the USA. Despite the growing public discontent data on this subject are limited. First of all, there is no epidemiological studies to assess the relationship between risk factors, such as air and water pollution, and health effects in populations living in close proximity to gas wells. The aim of this article is to identify and discuss existing concepts on the sources of environmental contamination, an indication of the environment elements under pressure and potential health risks arising from shale gas extraction. PMID:26016049

  13. Chemodectomas arising in temporal bone structures

    SciTech Connect

    Dickens, W.J.; Million, R.R.; Cassisi, N.J.; Singleton, G.T.

    1982-02-01

    Eighteen patients with chemodectomas arising in temporal bone structures were evaluated and treated at the University of Florida. Seventeen patients have each been followed a minimum of 3 years. Patients were retrospectively staged as having ''local'' or ''advanced'' disease, depending on the presence or absence of bone destruction and/or cranial nerve involvement. Fourteen of the patients received radiation therapy as all or part of their therapy; 6 patients were treated with radiation therapy alone, 3 patients were irradiated immediately postoperatively for residual disease, and 5 patients had radiation therapy for recurrence after operation. They were treated with cobalt-60 radiation with doses ranging from 3760 to 5640 rad. All irradiated patients demonstrated evidence of tumor regression, and none have had tumor recurrence with followup of 3-12 years. Of the 8 patients with cranial nerve paralysis prior to therapy, 5 had return of function of 1 or more cranial nerves. One of 6 patients treated initially with radiation therapy had a complication, while 6 of 8 patients irradiated postoperatively had complications. None of the complications were fatal. Three patients treated by operation for early disease limited to the hypotympanum had the disease controlled for 11-12 years. Guidelines for the selection of initial therapy are discussed.

  14. Temperature waves arising due to absorption of electromagnetic radiation in laminated media

    NASA Astrophysics Data System (ADS)

    Khabibullin, I. L.; Konovalova, S. I.; Sadykova, L. A.

    2015-05-01

    Propagation of electromagnetic radiation in a moving three-layer medium is studied. It is shown that travelling temperature waves are formed due to interference of the incident wave with the wave reflected from the interface between the layers with radiation energy dissipation. The frequency, length, and velocity of these waves are found to depend on the electromagnetic radiation frequency, electrophysical and thermophysical parameters of the medium, and velocity of medium motion.

  15. Absorption bands in the spectrum of Io

    NASA Technical Reports Server (NTRS)

    Cruikshank, D. P.; Jones, T. J.; Pilcher, C. B.

    1978-01-01

    Near-infrared spectra of Io in the region from 2.8 to 4.2 microns are reported which show distinct absorption features, the most notable at 4.1 microns. Frozen volatiles or atmospheric gases cannot account for these absorptions, nor do they resemble those seen in common silicate rocks. Several candidate substances, most notably nitrate and carbonate salts, show absorption features in this spectral region; the deepest band in the spectrum may be a nitrate absorption. The satellite surface is shown to be anhydrous, as indicated by the absence of the 3-micron bound water band.

  16. Trigonometric potentials arising from the spheroidal equation: Supersymmetric partners and integral formulas

    NASA Astrophysics Data System (ADS)

    Schulze-Halberg, Axel

    2016-06-01

    We construct supersymmetric partners of a quantum system featuring a class of trigonometric potentials that emerge from the spheroidal equation. Examples of both standard and confluent supersymmetric transformations are presented. Furthermore, we use integral formulas arising from the confluent supersymmetric formalism to derive new representations for single and multiple integrals of spheroidal functions.

  17. ABSORPTION ANALYZER

    DOEpatents

    Brooksbank, W.A. Jr.; Leddicotte, G.W.; Strain, J.E.; Hendon, H.H. Jr.

    1961-11-14

    A means was developed for continuously computing and indicating the isotopic assay of a process solution and for automatically controlling the process output of isotope separation equipment to provide a continuous output of the desired isotopic ratio. A counter tube is surrounded with a sample to be analyzed so that the tube is exactly in the center of the sample. A source of fast neutrons is provided and is spaced from the sample. The neutrons from the source are thermalized by causing them to pass through a neutron moderator, and the neutrons are allowed to diffuse radially through the sample to actuate the counter. A reference counter in a known sample of pure solvent is also actuated by the thermal neutrons from the neutron source. The number of neutrons which actuate the detectors is a function of a concentration of the elements in solution and their neutron absorption cross sections. The pulses produced by the detectors responsive to each neu tron passing therethrough are amplified and counted. The respective times required to accumulate a selected number of counts are measured by associated timing devices. The concentration of a particular element in solution may be determined by utilizing the following relation: T2/Ti = BCR, where B is a constant proportional to the absorption cross sections, T2 is the time of count collection for the unknown solution, Ti is the time of count collection for the pure solvent, R is the isotopic ratlo, and C is the molar concentration of the element to be determined. Knowing the slope constant B for any element and when the chemical concentration is known, the isotopic concentration may be readily determined, and conversely when the isotopic ratio is known, the chemical concentrations may be determined. (AEC)

  18. Movement Timing and Invariance Arise from Several Geometries

    PubMed Central

    Bennequin, Daniel; Fuchs, Ronit; Berthoz, Alain; Flash, Tamar

    2009-01-01

    Human movements show several prominent features; movement duration is nearly independent of movement size (the isochrony principle), instantaneous speed depends on movement curvature (captured by the 2/3 power law), and complex movements are composed of simpler elements (movement compositionality). No existing theory can successfully account for all of these features, and the nature of the underlying motion primitives is still unknown. Also unknown is how the brain selects movement duration. Here we present a new theory of movement timing based on geometrical invariance. We propose that movement duration and compositionality arise from cooperation among Euclidian, equi-affine and full affine geometries. Each geometry posses a canonical measure of distance along curves, an invariant arc-length parameter. We suggest that for continuous movements, the actual movement duration reflects a particular tensorial mixture of these canonical parameters. Near geometrical singularities, specific combinations are selected to compensate for time expansion or compression in individual parameters. The theory was mathematically formulated using Cartan's moving frame method. Its predictions were tested on three data sets: drawings of elliptical curves, locomotion and drawing trajectories of complex figural forms (cloverleaves, lemniscates and limaçons, with varying ratios between the sizes of the large versus the small loops). Our theory accounted well for the kinematic and temporal features of these movements, in most cases better than the constrained Minimum Jerk model, even when taking into account the number of estimated free parameters. During both drawing and locomotion equi-affine geometry was the most dominant geometry, with affine geometry second most important during drawing; Euclidian geometry was second most important during locomotion. We further discuss the implications of this theory: the origin of the dominance of equi-affine geometry, the possibility that the brain

  19. Ultrafast absorption difference spectra of the Fenna-Matthews-Olson protein at 19 K: experiment and simulations.

    PubMed Central

    Buck, D R; Savikhin, S; Struve, W S

    1997-01-01

    We describe simulations of absorption difference spectra in strongly coupled photosynthetic antennas. In the presence of large resonance couplings, distinctive features arise from excited-state absorption transitions between one- and two-exciton levels. We first outline the theory for the heterodimer and for the general N-pigment system, and we demonstrate the transition between the strong and weak coupling regimes. The theory is applied to Fenna-Matthews-Olson (FMO) bacteriochlorophyll a protein trimers from the green photosynthetic bacterium Prosthecochloris aestuarii and then compared with experimental low-temperature absorption difference spectra of FMO trimers from the green bacterium Chlorobium tepidum. Images FIGURE 1 FIGURE 7 FIGURE 8 FIGURE 12 PMID:8994590

  20. Mathematical problems arising in interfacial electrohydrodynamics

    NASA Astrophysics Data System (ADS)

    Tseluiko, Dmitri

    In this work we consider the nonlinear stability of thin films in the presence of electric fields. We study a perfectly conducting thin film flow down an inclined plane in the presence of an electric field which is uniform in its undisturbed state, and normal to the plate at infinity. In addition, the effect of normal electric fields on films lying above, or hanging from, horizontal substrates is considered. Systematic asymptotic expansions are used to derive fully nonlinear long wave model equations for the scaled interface motion and corresponding flow fields. For the case of an inclined plane, higher order terms are need to be retained to regularize the problem in the sense that the long wave approximation remains valid for long times. For the case of a horizontal plane the fully nonlinear evolution equation which is derived at the leading order, is asymptotically correct and no regularization procedure is required. In both physical situations, the effect of the electric field is to introduce a non-local term which arises from the potential region above the liquid film, and enters through the electric Maxwell stresses at the interface. This term is always linearly destabilizing and produces growth rates proportional to the cubic power of the wavenumber - surface tension is included and provides a short wavelength cut-off, that is, all sufficiently short waves are linearly stable. For the case of film flow down an inclined plane, the fully nonlinear equation can produce singular solutions (for certain parameter values) after a finite time, even in the absence of an electric field. This difficulty is avoided at smaller amplitudes where the weakly nonlinear evolution is governed by an extension of the Kuramoto-Sivashinsky (KS) equation. Global existence and uniqueness results are proved, and refined estimates of the radius of the absorbing ball in L2 are obtained in terms of the parameters of the equations for a generalized class of modified KS equations. The

  1. Fibrosarcoma arising from gouty tophi: report of a unique case and review of literature

    PubMed Central

    Wang, Jian-Jun; Wang, Hai-Yan; Cheng, Kai; Wang, Xuan; Yu, Bo; Shi, Shan-Shan; Zhou, Xiao-Jun; Shi, Qun-Li

    2015-01-01

    Fibrosarcoma is a malignant mesenchymal tumor. To the author’s best knowledge, no previous case of fibrosarcoma arising from gouty tophi has been reported. Here we reported the first case of fibrosarcoma arising from gouty tophi. A case of 58-year-old man was presented with a mass with ulcer and infection in the second joint of left middle finger for 2 months, with long standing gouty tophi. The tumor was biopsied and the biopsy showed complete excision of the tumor. With the pathological and immunohistochemical features considered, the diagnosis of fibrosarcoma associated with gouty tophi was made. The clinical findings, pathological characteristics and treatment were described. PMID:26097616

  2. Solitary fibrous tumor with malignant potential arising in sublingual gland.

    PubMed

    Ogawa, Ikuko; Sato, Sunao; Kudo, Yasusei; Miyauchi, Mutsumi; Sugiyama, Masaru; Suei, Yoshikazu; Takata, Takashi

    2003-01-01

    A rare case is described of a solitary fibrous tumor (SFT) with malignant potential arising in the sublingual gland. A 59-year-old man presented with a 4-month history of a slowly enlarging painless mass in the center of the floor of the mouth. The tumor was a well-demarcated, firm mass with a multicystic lesion. The tumor exhibited highly cellular areas of spindle cells with patternless architecture alternating with hypocellular areas. The tumor cells were positive for CD34 and bcl-2 as well as vimentin, and negative for epithelial, myogenic, neurogenic and histiocytic markers. The tumor cells formed multiple satellite nodules around dilated ducts in the multicystic lesion, indicating infiltrative growth. In addition, areas exhibiting higher cellularity with increased mitoses were noticed in the satellite nodules, although cellular atypia was not obvious. These findings led to a final diagnosis of SFT with malignant potential. There has been no recurrence or metastasis for 27 months after the surgery. Solitary fibrous tumor of the salivary gland must be differentiated from various spindle cell neoplasms including myogenic, peripheral nerve sheath, fibroblastic and fibro-histiocytic spindle cell neoplasms, hemangiopericytoma and myoepithelioma. In addition to characteristic morphological features, an immunohistochemical positivity for CD34 and bcl-2 may aid in the diagnosis of SFT.

  3. Mammalian Sleep Dynamics: How Diverse Features Arise from a Common Physiological Framework

    PubMed Central

    Phillips, Andrew J. K.; Robinson, Peter A.; Kedziora, David J.; Abeysuriya, Romesh G.

    2010-01-01

    Mammalian sleep varies widely, ranging from frequent napping in rodents to consolidated blocks in primates and unihemispheric sleep in cetaceans. In humans, rats, mice and cats, sleep patterns are orchestrated by homeostatic and circadian drives to the sleep–wake switch, but it is not known whether this system is ubiquitous among mammals. Here, changes of just two parameters in a recent quantitative model of this switch are shown to reproduce typical sleep patterns for 17 species across 7 orders. Furthermore, the parameter variations are found to be consistent with the assumptions that homeostatic production and clearance scale as brain volume and surface area, respectively. Modeling an additional inhibitory connection between sleep-active neuronal populations on opposite sides of the brain generates unihemispheric sleep, providing a testable hypothetical mechanism for this poorly understood phenomenon. Neuromodulation of this connection alone is shown to account for the ability of fur seals to transition between bihemispheric sleep on land and unihemispheric sleep in water. Determining what aspects of mammalian sleep patterns can be explained within a single framework, and are thus universal, is essential to understanding the evolution and function of mammalian sleep. This is the first demonstration of a single model reproducing sleep patterns for multiple different species. These wide-ranging findings suggest that the core physiological mechanisms controlling sleep are common to many mammalian orders, with slight evolutionary modifications accounting for interspecies differences. PMID:20585613

  4. Periosteal Osteosarcoma Arising from the Rib and Scapula: Imaging Features in Two Cases

    PubMed Central

    Hong, Jae Beom; Choi, Joon Hyuk

    2014-01-01

    Periosteal osteosarcoma is an extremely rare chondroblastic osteosarcoma in the flat bone. There were authors reporting of two cases of periosteal osteosarcoma in the highly unusual sites. One of them arose from the rib, in a 17-year-old male, which appeared as a hypodense juxtacortical mass with periosteal reaction on CT. The other one arose from the scapula, in a 17-year-old female, which showed the intermediate signal intensity (SI) on T1-weighted image (WI), heterogeneous high SI on T2WI, and rim-enhancement on contrast-enhanced T1WI with cortical destruction on MRI. PMID:24843242

  5. Slow light and saturable absorption

    NASA Astrophysics Data System (ADS)

    Selden, A. C.

    2009-06-01

    Quantitative analysis of slow light experiments utilising coherent population oscillation (CPO) in a range of saturably absorbing media, including ruby and alexandrite, Er3+:Y2SiO5, bacteriorhodopsin, semiconductor quantum devices and erbium-doped optical fibres, shows that the observations may be more simply interpreted as saturable absorption phenomena. A basic two-level model of a saturable absorber displays all the effects normally associated with slow light, namely phase shift and modulation gain of the transmitted signal, hole burning in the modulation frequency spectrum and power broadening of the spectral hole, each arising from the finite response time of the non-linear absorption. Only where hole-burning in the optical spectrum is observed (using independent pump and probe beams), or pulse delays exceeding the limits set by saturable absorption are obtained, can reasonable confidence be placed in the observation of slow light in such experiments. Superluminal (“fast light”) phenomena in media with reverse saturable absorption (RSA) may be similarly explained.

  6. Differential diagnosis of BPOP arising in relation to patella

    PubMed Central

    Pal, Jitendra Nath; Kar, Maitreyee; Hazra, Sunit; Basu, Anindya

    2015-01-01

    Introduction: Solitary exostosis is common at the metaphysis of long bones, and rarely may it develop in the lower pole of the patella. Usually it stops growing after skeletal maturity unless complicated. When the growth continues after skeletal maturity, other rare possibilities need to be considered such as bizarre parosteal osteochondromatous proliferation (BPOP). Though solitary exostosis is common at the metaphysis of long bones, very rarely it also develops in lower pole of the patella. Usually they stop growing after skeletal maturity unless complicated. When it starts after skeletal maturity and continues to grow, other rare possibilities like bizarre parostealosteochondromatousproliferation (BPOP) are to be thought of. Case Report: 21 years male student presented with anterior midline painless progressive swelling over right knee joint of one year duration which was hard, non-tender, fixed to patella but mobile with patella. X ray showed midline heterogeneously radio-opaque swelling attached to inferolateral aspect of the anterior surface of patella. Patellar out line is fully maintained except the narrow site of tumour attachment. After exposing through midline incision, the swelling was found to incorporate the patellar tendon completely and an anterior vertical midline cleavage was found. The mass was deliberately detached along the cleavage and from intact patellar tendon. Almost full range of knee movement is obtained in operation table. Immediate post operative 10° quadriceps lag was corrected with quadriceps setting exercises in two weeks time. Histopathological examination demonstrated thin layer of cartilage cover, irregular lamellar bone in deeper zone and spindle cells between them without cytoplasmic atypia. Plenty of cartilage cells in different stages of maturation are seen without column formation. Marrow elements are absent. Periosteum could not be demonstrated and there was no other evidence of malignancy. Features simulate

  7. The HI absorption "Zoo"

    NASA Astrophysics Data System (ADS)

    Geréb, K.; Maccagni, F. M.; Morganti, R.; Oosterloo, T. A.

    2015-03-01

    We present an analysis of the H I 21 cm absorption in a sample of 101 flux-selected radio AGN (S1.4 GHz> 50 mJy) observed with the Westerbork Synthesis Radio Telescope (WSRT). We detect H I absorption in 32 objects (30% of the sample). In a previous paper, we performed a spectral stacking analysis on the radio sources, while here we characterize the absorption spectra of the individual detections using the recently presented busy function. The H I absorption spectra show a broad variety of widths, shapes, and kinematical properties. The full width half maximum (FWHM) of the busy function fits of the detected H I lines lies in the range 32 km s-1absorption (FW20) lies in the range 63 km s-1 200 km s-1). We study the kinematical and radio source properties of each group, with the goal of identifying different morphological structures of H I. Narrow lines mostly lie at the systemic velocity and are likely produced by regularly rotating H I disks or gas clouds. More H I disks can be present among galaxies with lines of intermediate widths; however, the H I in these sources is more unsettled. We study the asymmetry parameter and blueshift/redshift distribution of the lines as a function of their width. We find a trend for which narrow profiles are also symmetric, while broad lines are the most asymmetric. Among the broadest lines, more lines appear blueshifted than redshifted, similarly to what was found by previous studies. Interestingly, symmetric broad lines are absent from the sample. We argue that if a profile is broad, it is also asymmetric and shifted relative to the systemic velocity because it is tracing unsettled H I gas. In particular, besides three of the broadest (up to FW20 = 825 km s-1

  8. 32 CFR 537.19 - Demands arising from maritime claims.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Demands arising from maritime claims. 537.19 Section 537.19 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY CLAIMS AND ACCOUNTS CLAIMS ON BEHALF OF THE UNITED STATES § 537.19 Demands arising from maritime claims. (a) It is essential that Army claims personnel...

  9. Triplet absorption spectroscopy and electromagnetically induced transparency

    NASA Astrophysics Data System (ADS)

    Ghafoor, F.; Nazmitdinov, R. G.

    2016-09-01

    Coherence phenomena in a four-level atomic system, cyclically driven by three coherent fields, are investigated thoroughly at zero and weak magnetic fields. Each strongly interacting atomic state is converted to a triplet due to a dynamical Stark effect. Two dark lines with a Fano-like profile arise in the triplet absorption spectrum with anomalous dispersions. We provide conditions to control the widths of the transparency windows by means of the relative phase of the driving fields and the intensity of the microwave field, which closes the optical system loop. The effect of Doppler broadening on the results of the triplet absorption spectroscopy is analysed in detail.

  10. Gas-Phase Polycyclic Aromatic Hydrocarbons in Absorption toward Protostellar Sources?

    NASA Astrophysics Data System (ADS)

    Bregman, Jesse D.; Temi, Pasquale

    2001-06-01

    One of the major criticisms of identifying the infrared emission bands with polycyclic aromatic hydrocarbon (PAH) molecules has been the lack of a match between laboratory spectra of individual PAHs and the emission features. Part of the difficulty arises from the complexity of modeling the emission mechanism with an a priori unknown mixture of ionized and neutral PAHs. A direct comparison between laboratory spectra of PAHs and astronomical sources is possible for absorption spectra. However, because of poor atmospheric transmission, ground-based spectra of the PAH absorption band in the C-H stretch region are too noisy to make a detailed comparison with laboratory spectra. In this paper we show that ISO Short Wavelength Spectrometer spectra of a few protostars that show a 3.25 μm absorption band can be well matched by laboratory absorption spectra of a mixture of isolated PAHs. Based on observations with ISO, an ESA project with instruments funded by ESA member states (especially the PI countries: France, Germany, the Netherlands, and the United Kingdom), with the participation of ISAS and NASA.

  11. The Surprising Absence of Absorption in the Far-ultraviolet Spectrum of Mrk 231

    NASA Technical Reports Server (NTRS)

    Veilleux, S.; Trippe, M.; Hamann, F.; Rupke, D. S. N.; Tripp, T. M.; Netzer, H.; Lutz, D.; Sembach, K. R.; Krug, H.; Teng, Stacy H.; Genzel, R.; Maiolino, R.; Sturm, E.; Tacconi, L.

    2013-01-01

    Mrk 231, the nearest (z = 0.0422) quasar, hosts both a galactic-scale wind and a nuclear-scale iron low-ionization broad absorption line (FeLoBAL) outflow. We recently obtained a far-ultraviolet (FUV) spectrum of this object covering approx. 1150-1470A with the Cosmic Origins Spectrograph on board the Hubble Space Telescope. This spectrum is highly peculiar, highlighted by the presence of faint (< or approx.2% of predictions based on H(alpha)), broad (> or approx.10,000 km/s at the base), and highly blueshifted (centroid at approx. 3500 km/s) Ly(aplpha) emission. The FUV continuum emission is slightly declining at shorter wavelengths (consistent with F(sub lambda) Alpha Lambda(sup 1.7)) and does not show the presence of any obvious photospheric or wind stellar features. Surprisingly, the FUV spectrum also does not show any unambiguous broad absorption features. It thus appears to be dominated by the AGN, rather than hot stars, and virtually unfiltered by the dusty FeLoBAL screen. The observed Ly(alpha) emission is best explained if it is produced in the outflowing BAL cloud system, while the Balmer lines arise primarily from the standard broad emission line region seen through the dusty (Av approx. 7 mag) broad absorption line region. Two possible geometric models are discussed in the context of these new results.

  12. High-resolution, vacuum-ultraviolet absorption spectrum of boron trifluoride

    SciTech Connect

    Hughes, Patrick P.; Thompson, Alan K.; Vest, Robert E.; Sprague, Matthew K.; Irikura, Karl K.; Beasten, Amy; McComb, Jacob C.; Al-Sheikhly, Mohamad; Coplan, Michael A.; Clark, Charles W.

    2014-11-21

    In the course of investigations of thermal neutron detection based on mixtures of {sup 10}BF{sub 3} with other gases, knowledge was required of the photoabsorption cross sections of {sup 10}BF{sub 3} for wavelengths between 135 and 205 nm. Large discrepancies in the values reported in existing literature led to the absolute measurements reported in this communication. The measurements were made at the SURF III Synchrotron Ultraviolet Radiation Facility at the National Institute of Standards and Technology. The measured absorption cross sections vary from 10{sup −20} cm{sup 2} at 135 nm to less than 10{sup −21} cm{sup 2} in the region from 165 to 205 nm. Three previously unreported absorption features with resolvable structure were found in the regions 135–145 nm, 150–165 nm, and 190–205 nm. Quantum mechanical calculations, using the TD-B3LYP/aug-cc-pVDZ variant of time-dependent density functional theory implemented in Gaussian 09, suggest that the observed absorption features arise from symmetry-changing adiabatic transitions.

  13. Localised fibrous mesothelioma arising in an intralobar pulmonary sequestration.

    PubMed Central

    Paksoy, N; Demircan, A; Altiner, M; Artvinli, M

    1992-01-01

    A localised fibrous mesothelioma arising from an intralobar lung sequestration occurred in a 64 year old Turkish woman. This appears to be the first report of a mesothelioma occurring within a pulmonary sequestration. Images PMID:1481189

  14. Warthin tumor arising from the minor salivary gland.

    PubMed

    Iwai, Toshinori; Baba, Junichi; Murata, Shogo; Mitsudo, Kenji; Maegawa, Jiro; Nagahama, Kiyotaka; Tohnai, Iwai

    2012-09-01

    Warthin tumor (WT) accounts for 4% to 13% of all salivary gland tumors. This benign tumor, which commonly arises in the parotid gland, is the second most common tumor of the salivary gland. WT is multicentric in 12% to 20% of patients and is bilateral in 5% to 14%. The mean age at diagnosis is 62 years (range, 12-92 years), and it rarely presents (<6%) before age 40 years. Extraparotid WT, arising from the submandibular gland or cervical lymph node for example, is very infrequent, with corresponding incidences of 0.4% to 6.9% and 8%, respectively. Moreover, WT arising from the minor salivary gland is extremely rare, with a reported incidence of merely 0.1% to 1.2%. We report here WT arising from the minor salivary gland in the buccal mucosa in a 66-year-old woman and review cases of WT of the minor salivary gland reported in the English literature.

  15. Electric reaction arising in bone subjected to mechanical loadings

    NASA Astrophysics Data System (ADS)

    Murasawa, Go; Cho, Hideo; Ogawa, Kazuma

    2006-03-01

    The aim of present study is the investigation of the electric reaction arising in bone subjected to mechanical loadings. Firstly, specimen was fabricated from femur of cow, and ultrasonic propagation in bone was measured by ultrasonic technique. Secondary, 4-point bending test was conducted up to fracture, and electric reaction arising in bone was measured during loading. Thirdly, cyclic 4-point bending test was conducted to investigate the effect of applied displacement speed on electric reaction.

  16. Thymoma type B1 arising in a giant supradiaphragmatic thymolipoma.

    PubMed

    Kaplan, Tevfik; Han, Serdar; Han, Unsal; Atac, Gokce Kaan; Yanik, Serdar

    2014-11-01

    Thymolipomas are uncommon tumors of the anterior mediastinum. They may extend into, but rarely stem from, the chest cavity. Furthermore, thymoma arising in a thymolipoma is extremely rare. We report a unique case of thymoma type B1 that originated form a giant thymolipoma located in the chest cavity, which was resected by a lateral thoracotomy in a 23-year-old woman. To our knowledge, this is the first reported case of thymoma type B1 arising within a giant thymolipoma.

  17. Pineal region schwannoma arising from the trochlear nerve.

    PubMed

    Chaudhry, Nauman S; Ahmad, Faiz U; Morcos, Jacques J

    2016-10-01

    Schwannomas arising from the trochlear nerve are very rare and to our knowledge, less than 35 histologically documented cases have been reported in the literature. There are no reports of a schwannoma in the pineal region. We report a 24-year-old woman who underwent a para-occipital trans-tentorial approach and gross total excision of a pineal region schwannoma arising from the trochlear nerve. This is the first such reported case. PMID:27496528

  18. DISENTANGLING THE CIRCUMNUCLEAR ENVIRONS OF CENTAURUS A. II. ON THE NATURE OF THE BROAD ABSORPTION LINE

    SciTech Connect

    Espada, D.; Matsushita, S.; Sakamoto, K.; Peck, A. B.; Henkel, C.; Iono, D.; Israel, F. P.; Muller, S.; Petitpas, G.; Pihlstroem, Y.; Taylor, G. B.; Trung, D. V.

    2010-09-01

    We report on atomic gas (H I) and molecular gas (as traced by CO(2-1)) redshifted absorption features toward the nuclear regions of the closest powerful radio galaxy, Centaurus A (NGC 5128). Our H I observations using the Very Long Baseline Array allow us to discern with unprecedented sub-parsec resolution H I absorption profiles toward different positions along the 21 cm continuum jet in the inner 0.''3 (or 5.4 pc). In addition, our CO(2-1) data obtained with the Submillimeter Array probe the bulk of the absorbing molecular gas with little contamination by emission, which was not possible with previous CO single-dish observations. We shed light on the physical properties of the gas in the line of sight with these data, emphasizing the still open debate about the nature of the gas that produces the broad absorption line ({approx}55 km s{sup -1}). First, the broad H I line is more prominent toward the central and brightest 21 cm continuum component than toward a region along the jet at a distance {approx}20 mas (or 0.4 pc) further from the nucleus. This indicates that the broad absorption line arises from gas located close to the nucleus, rather than from diffuse and more distant gas. Second, the different velocity components detected in the CO(2-1) absorption spectrum match well with other molecular lines, such as those of HCO{sup +}(1-0), except the broad absorption line that is detected in HCO{sup +}(1-0) (and most likely related to that of the H I). Dissociation of molecular hydrogen due to the active galactic nucleus seems to be efficient at distances r {approx}< 10 pc, which might contribute to the depth of the broad H I and molecular lines.

  19. Diagnostic pitfall in the diagnosis of mesenchymal chondrosarcoma arising in the central nervous system.

    PubMed

    Lin, Lisa; Varikatt, Winny; Dexter, Mark; Ng, Thomas

    2012-02-01

    Mesenchymal chondrosarcoma is a rare aggressive neoplasm typically affecting the bones of young adults. It may also arise in somatic soft tissue, the CNS and other organs. It has a characteristic biphasic histological pattern composed of highly undifferentiated small round cells and islands of well-differentiated hyaline cartilage. We report a case of mesenchymal chondrosarcoma arising from the right tentorium cerebelli in a 21-year-old woman with symptoms relating to mass effect. Histological examination demonstrated a purely small round cell appearance in a specimen obtained during partial resection at an outside institution, leading to an erroneous diagnosis of Ewing sarcoma/primitive neuroectodermal tumor (PNET). The diagnosis of mesenchymal chondrosarcoma was made only after tissue obtained during a definitive complete macroscopic removal involving the regional tentorium cerebelli, transverse and sigmoid dural venous sinuses which showed a prominent cartilaginous component. We discuss the features of mesenchymal chondrosarcoma arising in the CNS, the important differential diagnoses of small round-cell tumors within the CNS, and the differentiating features of mesenchymal chondrosarcoma from Ewing sarcoma/PNET, medulloblastoma, hemangiopericytoma, monophasic synovial sarcoma and atypical teratoid/rhabdoid tumour. PMID:21615516

  20. Neural regulation of intestinal nutrient absorption.

    PubMed

    Mourad, Fadi H; Saadé, Nayef E

    2011-10-01

    The nervous system and the gastrointestinal (GI) tract share several common features including reciprocal interconnections and several neurotransmitters and peptides known as gut peptides, neuropeptides or hormones. The processes of digestion, secretion of digestive enzymes and then absorption are regulated by the neuro-endocrine system. Luminal glucose enhances its own absorption through a neuronal reflex that involves capsaicin sensitive primary afferent (CSPA) fibres. Absorbed glucose stimulates insulin release that activates hepatoenteric neural pathways leading to an increase in the expression of glucose transporters. Adrenergic innervation increases glucose absorption through α1 and β receptors and decreases absorption through activation of α2 receptors. The vagus nerve plays an important role in the regulation of diurnal variation in transporter expression and in anticipation to food intake. Vagal CSPAs exert tonic inhibitory effects on amino acid absorption. It also plays an important role in the mediation of the inhibitory effect of intestinal amino acids on their own absorption at the level of proximal or distal segment. However, chronic extrinsic denervation leads to a decrease in intestinal amino acid absorption. Conversely, adrenergic agonists as well as activation of CSPA fibres enhance peptides uptake through the peptide transporter PEPT1. Finally, intestinal innervation plays a minimal role in the absorption of fat digestion products. Intestinal absorption of nutrients is a basic vital mechanism that depends essentially on the function of intestinal mucosa. However, intrinsic and extrinsic neural mechanisms that rely on several redundant loops are involved in immediate and long-term control of the outcome of intestinal function.

  1. Enhanced absorption cycle computer model

    NASA Astrophysics Data System (ADS)

    Grossman, G.; Wilk, M.

    1993-09-01

    Absorption heat pumps have received renewed and increasing attention in the past two decades. The rising cost of electricity has made the particular features of this heat-powered cycle attractive for both residential and industrial applications. Solar-powered absorption chillers, gas-fired domestic heat pumps, and waste-heat-powered industrial temperature boosters are a few of the applications recently subjected to intensive research and development. The absorption heat pump research community has begun to search for both advanced cycles in various multistage configurations and new working fluid combinations with potential for enhanced performance and reliability. The development of working absorption systems has created a need for reliable and effective system simulations. A computer code has been developed for simulation of absorption systems at steady state in a flexible and modular form, making it possible to investigate various cycle configurations with different working fluids. The code is based on unit subroutines containing the governing equations for the system's components and property subroutines containing thermodynamic properties of the working fluids. The user conveys to the computer an image of his cycle by specifying the different subunits and their interconnections. Based on this information, the program calculates the temperature, flow rate, concentration, pressure, and vapor fraction at each state point in the system, and the heat duty at each unit, from which the coefficient of performance (COP) may be determined. This report describes the code and its operation, including improvements introduced into the present version. Simulation results are described for LiBr-H2O triple-effect cycles, LiCl-H2O solar-powered open absorption cycles, and NH3-H2O single-effect and generator-absorber heat exchange cycles. An appendix contains the user's manual.

  2. Automatic detection of EEG artefacts arising from head movements using EEG and gyroscope signals.

    PubMed

    O'Regan, Simon; Faul, Stephen; Marnane, William

    2013-07-01

    Contamination of EEG signals by artefacts arising from head movements has been a serious obstacle in the deployment of automatic neurological event detection systems in ambulatory EEG. In this paper, we present work on categorizing these head-movement artefacts as one distinct class and on using support vector machines to automatically detect their presence. The use of additional physical signals in detecting head-movement artefacts is also investigated by means of support vector machines classifiers implemented with gyroscope waveforms. Finally, the combination of features extracted from EEG and gyroscope signals is explored in order to design an algorithm which incorporates both physical and physiological signals in accurately detecting artefacts arising from head-movements.

  3. Identification of Gas Phase PAHs in Absorption Towards Protostellar Sources

    NASA Technical Reports Server (NTRS)

    Bregman, Jesse D.; Temi, Pasquale; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The infrared emission bands (also known as the UIR bands.) have recently been observed in absorption at 3.25 micrometers in the ices surrounding a few proto-stellar objects at 11.2 micrometers in MonR2, and at 6.2 micrometers towards two sources near the galactic center. The UIR bands have been observed in emission for many years, but identifying these bands has proven to be both difficult and contentious as no one has yet found a single material that provides a good match to the features. However, most investigators agree that some form of carbon-based material with aromatic bonds is the most likely candidate, and many arguments favor free molecules (polycyclic aromatic hydrocarbons, PAHs) as the carriers of at least the narrow emission bands. Since the emission arises not from a single molecule but from a family of molecules, identifying which PAHs are contributing to the infrared emission bands is difficult. The identification is further complicated by the fact that the emission at short wavelengths is dominated by small molecules while at long wavelengths it is dominated by large molecules. Thus, for example, the emission at 3.3 micrometers is from a different mix of molecules than those which produce the 11.2 micrometer band. To complicate matters further, the molecular mix includes both neutral and ionic species. In absorption, the same mixture of molecules contributes at all wavelengths and the molecules should be neutral, potentially simplifying comparisons with lab data. Also, absorption strengths measured in the lab are directly applicable to interstellar absorption bands without the need to model an emission spectrum of an unknown mixture of ionized and neutral PAHs. In this paper we show that a mixture of argon matrix isolated PAH molecules can reproduce the 3.25 micrometers absorption band seen in the ISO SWS spectra of four embedded Infrared sources, S140 IRS1, AFGL 2591, Elias 29, and AFGL 989. In section 2 we describe the ISO SWS data analysis and

  4. Primary salivary duct carcinoma arising from the Stensen duct.

    PubMed

    Noda, Kenji; Hirano, Takashi; Okamoto, Tomoyo; Suzuki, Masashi

    2016-09-01

    This report describes a salivary duct carcinoma (SDC) arising from the extraglandular portion of the Stensen duct. The patient was a 56-year-old man who presented with a palpable, elastic, hard mass without tenderness in the right cheek. Computed tomography revealed a tumor of the extraglandular portion of the Stensen duct. Supraomohyoid right neck dissection and total right parotidectomy were performed, and the histologic diagnosis was SDC of the Stensen duct. Postoperatively, the patient received no additional treatment. Neither recurrence nor metastasis was observed during 4 years of follow-up examination. SDC of the Stensen duct is extremely rare. To our knowledge, there is no report that describes primary SDC arising from that location. We also believe this is the first report that describes the clinical course of primary SDC arising from a Stensen duct. PMID:27657321

  5. ON THE 10 mum SILICATE FEATURE IN ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Nikutta, Robert; Elitzur, Moshe; Lacy, Mark E-mail: moshe@pa.uky.ed

    2009-12-20

    The 10 mum silicate feature observed with Spitzer in active galactic nuclei (AGNs) reveals some puzzling behavior. It (1) has been detected in emission in type 2 sources, (2) shows broad, flat-topped emission peaks shifted toward long wavelengths in several type 1 sources, and (3) is not seen in deep absorption in any source observed so far. We solve all three puzzles with our clumpy dust radiative transfer formalism. Addressing (1), we present the spectral energy distribution (SED) of SST1721+6012, the first type 2 quasar observed to show a clear 10 mum silicate feature in emission. Such emission arises in models of the AGN torus easily when its clumpy nature is taken into account. We constructed a large database of clumpy torus models and performed extensive fitting of the observed SED. We find that the cloud radial distribution varies as r {sup -1.5} and the torus contains 2-4 clouds along radial equatorial rays, each with optical depth at visual approx60-80. The source bolometric luminosity is approx3 x 10{sup 12} L{sub sun}. Our modeling suggests that approx<35% of objects with tori sharing these characteristics and geometry would have their central engines obscured. This relatively low obscuration probability can explain the clear appearance of the 10 mum emission feature in SST1721+6012 together with its rarity among other QSO2. Investigating (2), we also fitted the SED of PG1211+143, one of the first type 1 QSOs with a 10 mum silicate feature detected in emission. Together with other similar sources, this QSO appears to display an unusually broadened feature whose peak is shifted toward longer wavelengths. Although this led to suggestions of non-standard dust chemistry in these sources, our analysis fits such SEDs with standard galactic dust; the apparent peak shifts arise from simple radiative transfer effects. Regarding (3), we find additionally that the distribution of silicate feature strengths among clumpy torus models closely resembles the observed

  6. Gastrointestinal Stromal Tumor Arising From a Gastric Duplication Cyst

    PubMed Central

    Machicado, Jorge; Davogustto, Giovanni

    2016-01-01

    Gastric duplication cysts (GDC) are rarely diagnosed in adults, but previous cases have been associated with malignancy. We present a case of gastrointestinal stromal tumor (GIST) arising from a GDC in a 71-year-old woman who presented with 3 years of early satiety, anorexia, abdominal distention, and weight loss. Abdominal CT showed a 9.3 x 5.2 x 9.5-cm well-circumscribed cystic mass arising 3 cm above the gastroduodenal junction. The cyst was resected, and histopathology was consistent with GDC. Future studies are needed to clarify the malignant potential of GDC and the molecular pathways for its development. PMID:27144196

  7. Malignancy arising in endometriosis associated with unopposed estrogen replacement.

    PubMed

    Reimnitz, C; Brand, E; Nieberg, R K; Hacker, N F

    1988-03-01

    Malignant transformation of endometriosis is a well documented phenomenon. Although it occurs most commonly in the ovaries, there have been approximately 50 reported cases of extraovarian malignant transformation of endometriosis. This paper presents two cases of malignancy arising from a dormant focus of endometriosis after total abdominal hysterectomy, bilateral salpingo-oophorectomy, and exogenous estrogen replacement therapy. These malignancies are often well differentiated and may behave similarly to estrogen-induced endometrial carcinomas. After surgical castration of a premenopausal woman with endometriosis, the use of progestins in replacement therapy may reduce the risk of malignancy arising in endometriosis.

  8. Dust in MG II Absorption Systems

    NASA Astrophysics Data System (ADS)

    Malhotra, S.

    The dust absorption feature at 2175 AA is detected in a composite spectrum of Mg II absorbers. The composite absorber spectrum is obtained by taking the geometric mean of 92 quasar spectra after aligning them in the rest-frame of 96 absorbers. By aligning the spectra according to absorber redshifts we reinforce the spectral features of the absorbers, and smooth over possible bumps and wiggles in the emission spectra. The width of the observed absorption feature is 200-300 AA (FWHM), or 0.4-0.6 microns^{-1} and the central wavelength is 2240 AA. The Galactic dust feature has a central wavelength of 2176 AA and FWHM = 0.8-1.25 microns^{-1}. Simulations show that this discrepancy between the properties of the 2175 AA feature in Mg II absorbers and Galactic ISM can be mostly explained by the different methods used to measure them (cf. Malhotra 1997).

  9. Coherent Absorption of N00N States.

    PubMed

    Roger, Thomas; Restuccia, Sara; Lyons, Ashley; Giovannini, Daniel; Romero, Jacquiline; Jeffers, John; Padgett, Miles; Faccio, Daniele

    2016-07-01

    Recent results in deeply subwavelength thickness films demonstrate coherent control and logical gate operations with both classical and single-photon light sources. However, quantum processing and devices typically involve more than one photon and nontrivial input quantum states. Here we experimentally investigate two-photon N00N state coherent absorption in a multilayer graphene film. Depending on the N00N state input phase, it is possible to selectively choose between single- or two-photon absorption of the input state in the graphene film. These results demonstrate that coherent absorption in the quantum regime exhibits unique features, opening up applications in multiphoton spectroscopy and imaging. PMID:27447505

  10. Coherent Absorption of N00N States

    NASA Astrophysics Data System (ADS)

    Roger, Thomas; Restuccia, Sara; Lyons, Ashley; Giovannini, Daniel; Romero, Jacquiline; Jeffers, John; Padgett, Miles; Faccio, Daniele

    2016-07-01

    Recent results in deeply subwavelength thickness films demonstrate coherent control and logical gate operations with both classical and single-photon light sources. However, quantum processing and devices typically involve more than one photon and nontrivial input quantum states. Here we experimentally investigate two-photon N00N state coherent absorption in a multilayer graphene film. Depending on the N00N state input phase, it is possible to selectively choose between single- or two-photon absorption of the input state in the graphene film. These results demonstrate that coherent absorption in the quantum regime exhibits unique features, opening up applications in multiphoton spectroscopy and imaging.

  11. A leiomyoma arising from the deep palmar arterial arch.

    PubMed

    Yagi, K; Hamada, Y; Yasui, N

    2006-12-01

    Vascular leiomyomas, or angioleiomyomas, are benign tumours originating from smooth non-striated muscle. Leiomyomas in the hand are uncommon and their pre-operative diagnosis is difficult. We report a 65 year-old woman who developed a vascular leiomyoma arising from the deep palmar arterial arch.

  12. ARISE: A Challenging 25-m Space Antenna Design

    NASA Technical Reports Server (NTRS)

    Rahmat-Samii, Yahya; Hoferer, Robert A.

    1999-01-01

    ARISE (Advanced Radio Interferometry between Space and Earth). Future scientific and communications missions are conceptualizing using very large reflector antennas in space. The antenna dimensions are targeted from lOm to 25m beyond. Frequencies coveting L-band through W-band are being considered. these challenging missions, one may refer to ARISE (Advanced Radio Interferometry between Space and Earth), which is projected to utilize a 25-m dual Gregorian optics operating from 8 GHz to 86 Gl-lz . An artist's renditions Gregorian antenna concept is shown . The objective of this mission is to create a space-based VLBI system (integrated with ground based antennas) for high resolution mapping of black holes. Successful realization of ARISE necessitates development of several technologies . The most crucial technology is that of the deployable 25-m reflector that must work at frequencies as high as 43 and 86 GHz. The current baseline selection for ARISE is an inflatable antenna, under development for several other applications in communications and remote sensing.

  13. Transcultural Knowledge and Skills Transfer: Issues Arising from Evaluation Processes

    ERIC Educational Resources Information Center

    Green, Anita J.; Holloway, David G.

    2007-01-01

    The transfer of knowledge, policy and practice between nations increasingly involves knowledge of the theory and practice of evaluation. This article examines issues arising from the transcultural evaluation of a drug and alcohol misuse knowledge and skills transfer programme for nurses, nurse teachers and medical staff in the narcology service in…

  14. Errors arising from incorrect orientation of E test strips.

    PubMed Central

    Hamilton-Miller, J M; Shah, S; Yam, T S

    1995-01-01

    Major errors arise if E test strips are placed upside down. Asymmetric zones, or no zone at all, may result. MICs indicated by upside-down tests were almost always considerably higher than true values. This situation differs markedly from that for conventional testing, where orientation of disks is not important. PMID:7665686

  15. Iron Absorption in Drosophila melanogaster

    PubMed Central

    Mandilaras, Konstantinos; Pathmanathan, Tharse; Missirlis, Fanis

    2013-01-01

    The way in which Drosophila melanogaster acquires iron from the diet remains poorly understood despite iron absorption being of vital significance for larval growth. To describe the process of organismal iron absorption, consideration needs to be given to cellular iron import, storage, export and how intestinal epithelial cells sense and respond to iron availability. Here we review studies on the Divalent Metal Transporter-1 homolog Malvolio (iron import), the recent discovery that Multicopper Oxidase-1 has ferroxidase activity (iron export) and the role of ferritin in the process of iron acquisition (iron storage). We also describe what is known about iron regulation in insect cells. We then draw upon knowledge from mammalian iron homeostasis to identify candidate genes in flies. Questions arise from the lack of conservation in Drosophila for key mammalian players, such as ferroportin, hepcidin and all the components of the hemochromatosis-related pathway. Drosophila and other insects also lack erythropoiesis. Thus, systemic iron regulation is likely to be conveyed by different signaling pathways and tissue requirements. The significance of regulating intestinal iron uptake is inferred from reports linking Drosophila developmental, immune, heat-shock and behavioral responses to iron sequestration. PMID:23686013

  16. On the Ammonia Absorption on Saturn

    NASA Astrophysics Data System (ADS)

    Tejfel, Victor G.; Karimov, A. M.; Lyssenko, P. G.; Kharitonova, G. A.

    2015-11-01

    The ammonia absorption bands centered at wavelengths of 645 and 787 nm in the visible spectrum of Saturn are very weak and overlapped with more strong absorption bands of methane. Therefore, the allocation of these bands is extremely difficult. In fact, the NH3 band 787 nm is completely masked by methane. The NH3 645 nm absorption band is superimposed on a relatively weak shortwave wing of CH4 band, in which the absorption maximum lies at the wavelength of 667 nm. In 2009, during the equinox on Saturn we have obtained the series of zonal spectrograms by scanning of the planet disk from the southern to the northern polar limb. Besides studies of latitudinal variation of the methane absorption bands we have done an attempt to trace the behavior of the absorption of ammonia in the band 645 nm. Simple selection of the pure NH3 profile of the band was not very reliable. Therefore, after normalizing to the ring spectrum and to the level of the continuous spectrum for entire band ranging from 630 to 680 nm in the equivalent widths were calculated for shortwave part of this band (630-652 nm), where the ammonia absorption is present, and a portion of the band CH4 652-680 nm. In any method of eliminating the weak part of the methane uptake in the short wing show an increased ammonia absorption in the northern hemisphere compared to the south. This same feature is observed also in the behavior of weak absorption bands of methane in contrast to the more powerful, such as CH4 725 and 787 nm. This is due to the conditions of absorption bands formation in the clouds at multiple scattering. Weak absorption bands of methane and ammonia are formed on the large effective optical depths and their behavior reflects the differences in the degree of uniformity of the aerosol component of the atmosphere of Saturn.

  17. Relative f-values from interstellar absorption lines: advantages and pitfalls

    NASA Astrophysics Data System (ADS)

    Jenkins, Edward B.

    2009-05-01

    Interstellar absorption features seen in the ultraviolet and visible spectra of stars provide opportunities for comparing the strengths of different transitions out of the ground electronic states of atoms, ions and simple molecules. In principle, such measurements are straightforward since the radiative transfer is manifested as a simple exponential absorption law at any given radial velocity. Complications arise when the velocity structures of the lines are not completely resolved, or when the lines are either very strongly saturated or too weak to observe. Dynamic range limitations can compromise the comparisons of two transitions that have very different absorption f-values, but they can be mitigated if there are examples with very different column densities and transitions of intermediate strength that can help to bridge the large gap in line strengths. Attempts to unravel the effects of saturation include the use of a curve of growth when only equivalent widths are available, or the measurements of the 'apparent optical depth' when the line is mostly resolved by the instrument. Unfortunately, the application of the curve of growth for one constituent to that of another can sometimes create systematic errors, since the two may have different velocity structures. Likewise, unresolved fine velocity structures in features that have large optical depths can make the apparent optical depths misrepresent the smoothed versions of the true optical depths. One method to compare the strength of a very weak line to that of a very strong one is to measure the total absorption of the former and compare it with the strength of the damping wings of the latter. However in many circumstances, small amounts of gas at velocities well displaced from the line center can masquerade as damping wings. For this reason, it is important to check that these wings have the proper shape.

  18. Intracranial invasion from a primary adenocarcinoma arising in the middle and external ear.

    PubMed

    McDonald, M; Brophy, B P; Raymond, W

    1995-06-01

    Cerumenal adenocarcinoma is a rare neoplasm arising from the modified sweat glands of the ear. Before the diagnosis of primary tumour is made, a thorough search must be undertaken to exclude the possibility of metastatic disease, which occurs more commonly. Benign adenoma can also occur and this may be identical histologically to the malignant variety. The presence of local invasiveness may be the only differentiating feature. Aggressive local resection followed by postoperative radiotherapy form the cornerstone of management. Individuals treated with radiotherapy alone have a life expectancy of less than 12 months whereas cures have been reported with radical surgery.

  19. Oligodendroglioma arising in a mature cystic ovarian teratoma in a child.

    PubMed

    Büyükka Bay, Sema; Corapcioglu, Funda; Kavurt, Sumru; Müezzinoğlu, Bahar; Anik, Yonca; Tugay, Melih

    2010-11-01

    In childhood mature cystic teratomas are the most common type of ovarian germ cell tumors. Tumors of neuroepithelial origin are extremely rare in mature teratomas. To the authors' knowledge, this is the first case report oligodendroglioma arising in a mature cystic ovarian teratoma in children. A 13-year-old girl presented with a history of pelvic pain for 2 months. An ultrasound examination showed a monolateral multicystic, calcific ovarian mass, measuring approximately 6 x 5 cm, arising in the left over and adnexia, suggesting a teratoma. An exploratorative laparotomy and ooferectomy were performed. On histopatological examination, various samples from cystic areas had mature tissues from all 3 germ cell layers, including skin, bone, bronchial structures, and cerebellum. Sections from solid areas showed uniform population of monotonous, rounded cells with indistinct cytoplasm and having perinuclear halo (fried-egg appearance) on a fibrillary, neuropilic background. Microcalcifications as calcospherites were noted in the stroma. Based on the typical morphological features, the cased was diagnosed as mature cystic teratoma with low-grade oligodendroglioma. To the authors' knowledge, there are a few reports in the literature of an oligodendroglioma arising in an ovarian teratoma in adults and this presented patient is the first case in childhood.

  20. Near-Infrared Localized Surface Plasmon Resonances Arising from Free Carriers in Doped Quantum Dots

    SciTech Connect

    Jain, Prashant K.; Luther, Joey; Ewers, Trevor; Alivisatos, A. Paul

    2010-10-12

    Quantum confinement of electronic wavefunctions in semiconductor quantum dots (QDs) yields discrete atom-like and tunable electronic levels, thereby allowing the engineering of excitation and emission spectra. Metal nanoparticles, on the other hand, display strong resonant interactions with light from localized surface plasmon resonance (LSPR) oscillations of free carriers, resulting in enhanced and geometrically tunable absorption and scattering resonances. The complementary attributes of these nanostructures lends strong interest toward integration into hybrid nanostructures to explore enhanced properties or the emergence of unique attributes arising from their interaction. However, the physicochemical interface between the two components can be limiting for energy transfer and synergistic coupling within such a hybrid nanostructure. Therefore, it is advantageous to realize both attributes, i.e., LSPRs and quantum confinement within the same nanostructure. Here, we describe well-defined LSPRs arising from p-type carriers in vacancy-doped semiconductor quantum dots. This opens up possibilities for light harvesting, non-linear optics, optical sensing and manipulation of solid-state processes in single nanocrystals.

  1. Analysis of the vibratory excitation arising from spiral bevel gears

    NASA Technical Reports Server (NTRS)

    Mark, William D.

    1987-01-01

    Tools required to understand and predict in terms of its underlying causes the vibratory excitation arising from meshing spiral bevel gears are developed. A generalized three component transmission error of meshing spiral bevel gears is defined. Equations are derived that yield the three components of the generalized transmission error in terms of deviations of tooth running surfaces from equispaced perfect spherical involute surfaces and tooth/gearbody elastic deformations arising from the three components of the generalized force transmitted by the meshing gears. A method for incorporating these equations into the equations of motion of a gear system is described. Equations are derived for the three components of the generalized force transmitted by the gears which are valid whenever inertial effects of the meshing gears and their supports are negligible. Bearing offsets from the positions occupied by the shaft centerlines of perfect spherical involute bevel gears and bearing/bearing support flexibilities enter into the computation of these forces.

  2. Adenocarcinoma arising in warthin tumor of the parotid gland.

    PubMed

    Sayar, Hamide; Öztarakçi, Hüseyin; Sayar, Çağdaş; Ağirbaş, Şule

    2012-01-01

    Warthin tumor is a well-defined benign salivary gland neoplasm consisting of both epithelial and lymphoid components. The tumor is the second most common benign tumor next to pleomorphic adenoma. We present a case of adenocarcinoma, not otherwise classified, arising in unilateral Warthin tumor of the parotid gland in a 63-year-old male patient. Carcinomas arising in or from the epithelial component of a preexisting parotid Warthin tumor are rare and differential diagnosis of metastasis from an adenocarcinoma in Warthin tumor is important. The patient underwent a complete and thorough work-up, and no other primary malignant lesion was found. No other primary malignant lesion had manifested at the last one year follow-up period.

  3. In-line absorption sensor based on coiled optical microfiber

    NASA Astrophysics Data System (ADS)

    Lorenzi, Roberto; Jung, Yongmin; Brambilla, Gilberto

    2011-04-01

    We fabricated and tested an evanescent-wave absorption sensor consisting of an optical microfiber coil resonator embedded in fluidic channel walls. Low concentrations of flowing analyte show optical losses in agreement with a modified Beer-Lambert law. Higher concentration causes a limit value of the measured optical losses arising from adsorption mechanisms.

  4. Solitary Osteochondroma Arising from Cervical Spina Bifida Occulta

    PubMed Central

    Ofluoglu, Ali Ender

    2013-01-01

    Solitary osteochondromas are common benign long bone tumors originating from cartilage. They may produce a wide variety of symptoms and complications depending on their spinal location. These may include compressive myelopathy, nerve root compression, pathologic fracture and malignant degeneration, or in some cases only pain. Solitary cervical spine osteochondromas have been reported mostly in the neural arch or vertebral body. This report describes a patient presenting with neck pain, with a benign osteochondroma arising in the right bifid C5 lamina. PMID:24383028

  5. Papillary cystadenoma arising from the upper lip: a case report.

    PubMed

    Matsuzaka, Kenichi; Kokubu, Eitoyo; Takeda, Eizo; Tanaka, Yoichi; Shimono, Masaki; Inoue, Takashi

    2003-11-01

    We report a rare case of a papillary cystadenoma arising from the upper lip. This tumor was not distinctly encapsulated and had proliferated replacing the ductal epithelium. Mast cells were found not only in the stroma but also in the oncocytic epithelial layer. There was a strong immunoreaction with mitochondrial antibody in the epithelial layer. Only one case (0.9%) of papillary cystadenoma has occurred among the 110 benign intraoral salivary gland tumors seen in our hospital from 1966 through September 2003.

  6. Squamous cell carcinoma arising in previously burned or irradiated skin

    SciTech Connect

    Edwards, M.J.; Hirsch, R.M.; Broadwater, J.R.; Netscher, D.T.; Ames, F.C.

    1989-01-01

    Squamous cell carcinoma (SCC) arising in previously burned or irradiated skin was reviewed in 66 patients treated between 1944 and 1986. Healing of the initial injury was complicated in 70% of patients. Mean interval from initial injury to diagnosis of SCC was 37 years. The overwhelming majority of patients presented with a chronic intractable ulcer in previously injured skin. The regional relapse rate after surgical excision was very high, 58% of all patients. Predominant patterns of recurrence were in local skin and regional lymph nodes (93% of recurrences). Survival rates at 5, 10, and 20 years were 52%, 34%, and 23%, respectively. Five-year survival rates in previously burned and irradiated patients were not significantly different (53% and 50%, respectively). This review, one of the largest reported series, better defines SCC arising in previously burned or irradiated skin as a locally aggressive disease that is distinct from SCC arising in sunlight-damaged skin. An increased awareness of the significance of chronic ulceration in scar tissue may allow earlier diagnosis. Regional disease control and survival depend on surgical resection of all known disease and may require radical lymph node dissection or amputation.

  7. Opposite phenotypes of cancer and aging arise from alternative regulation of common signaling pathways.

    PubMed

    Ukraintseva, Svetlana V; Yashin, Anatoly I

    2003-12-01

    Phenotypic features of malignant and senescent cells are in many instances opposite. Cancer cells do not "age"; their metabolic, proliferative, and growth characteristics are opposite to those observed with cellular aging (both replicative and functional). In many such characteristics cancer cells resemble embryonic cells. One can say that cancer manifests itself as a local, uncontrolled "rejuvenation" in an organism. Available evidence from human and animal studies suggests that the opposite phenotypic features of aging and cancer arise from the opposite regulation of genes participating in apoptosis/growth arrest or growth signal transduction pathways in cells. This fact may be applicable in the development of new anti-aging treatments. Genes that are contrarily regulated in cancer and aging cells (e.g., proto-oncogenes or tumor suppressors) could be candidate targets for anti-aging interventions. Their "cancer-like" regulation, if strictly controlled, might help to rejuvenate the human organism. PMID:15033776

  8. Malignant myoepithelioma arising from recurrent pleomorphic adenoma of minor salivary gland.

    PubMed

    Yoshizaki, Tomokazu; Himi, Yuji; Minato, Hiroshi; Ogawa, Ikuko; Nikai, Hiromasa; Furukawa, Mitsuru

    2002-01-01

    Malignant myoepitheliomas of the salivary gland are very rare tumors which may either arise de novo or develop in a pre-existing pleomorphic adenoma. We report a case of malignant myoepithelioma of the minor salivary gland that progressed from benign pleomorphic adenoma. The original pleomorphic adenoma was resected in 1979 (the '79 tumor). The first recurrent tumor was operated in 1995 (the '95 tumor). The '95 tumor was diagnosed as pleomorphic adenoma. Although the myoepithelial tumor component was more prevalent in the '95 tumor, histological features of the first recurrent tumor were similar to the '79 tumor. The second recurrent tumor showed more aggressive clinical features (the '98 tumor). It also showed massive growth of myoepithelial tumor cells with bone invasion, which led to the diagnosis of the '98 tumor as malignant myoepithelioma. With adequate surgical margin, the patient has been free from tumor recurrence for 20 months.

  9. A solitary fibrous tumor arising in the parapharyngeal space, with MRI and FDG-PET findings.

    PubMed

    Wakisaka, Naohiro; Kondo, Satoru; Murono, Shigeyuki; Minato, Hiroshi; Furukawa, Mitsuru; Yoshizaki, Tomokazu

    2009-06-01

    We present the imaging and pathological features of a 38-year-old man in whom a large parapharyngeal solitary fibrous tumor (SFT) on the left side was found. On MRI, the tumor showed a nodule-in-nodule appearance. The inner nodule revealed high signal intensities both on T1- and T2-weighted MR images. The entire tumor showed heterogeneous enhancement on gadolinium-enhanced T1-weighted images. (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) identified heterogeneous radiotracer uptake of FDG in the inner nodule of the tumor. Histologic examinations revealed an admixture of growth patterns, including a "patternless pattern" and "haemangiopericytoma-like pattern". The tumor was positive for CD34. Imaging features of SFT arising in the parapharyngeal space are discussed with a review of literatures. This is the first report of FDG-PET finding of SFT arising in the head and neck. More cases are needed to achieve diagnostic significance from FDG-PET findings of parapharyngeal SFTs.

  10. Time-variable Aluminum Absorption in the Polar AR Ursae Majoris, and an Updated Estimate for the Mass of the White Dwarf

    NASA Astrophysics Data System (ADS)

    Bai, Yu; Justham, Stephen; Liu, JiFeng; Guo, JinCheng; Gao, Qing; Gong, Hang

    2016-09-01

    We present spectra of the extreme polar AR Ursae Majoris (AR UMa), which display a clear Al i absorption doublet, alongside spectra taken less than a year earlier in which that feature is not present. Re-examination of earlier SDSS spectra indicates that the Al i absorption doublet was also present ≈8 years before our first non-detection. We conclude that this absorbing material is unlikely to be on the surface of either the white dwarf (WD) or the donor star. We suggest that this Al i absorption feature arises in circumstellar material, perhaps produced by the evaporation of asteroids as they approach the hot WD. The presence of any remaining reservoir of rocky material in AR UMa might help to constrain the prior evolution of this unusual binary system. We also apply spectral decomposition to find the stellar parameters of the M dwarf companion, and attempt to dynamically measure the mass of the WD in AR UMa by considering both the radial velocity curves of the H β emission line and the Na i absorption line. Thereby we infer a mass range for the WD in AR UMa of 0.91 M ⊙ < M WD < 1.24 M ⊙.

  11. Solar absorption surface panel

    DOEpatents

    Santala, Teuvo J.

    1978-01-01

    A composite metal of aluminum and nickel is used to form an economical solar absorption surface for a collector plate wherein an intermetallic compound of the aluminum and nickel provides a surface morphology with high absorptance and relatively low infrared emittance along with good durability.

  12. Implications of high-velocity interstellar H I absorption features

    NASA Technical Reports Server (NTRS)

    Cowie, L.; York, D. G.; Laurent, C.; Vidal-Madjar, A.

    1979-01-01

    Contributions to the interstellar H I column density at high velocities from immediate postshock gas and from the cooling gas behind a shock are compared. The detection of high-velocity H I in L-epsilon and L-delta for Iota Ori is reported and interpreted as cooling gas behind a shock of 100 km/s velocity. The immediate postshock gas should be observable for shock velocities greater than 200 km/s and permits direct determination of the velocities of adiabatic shocks in the interstellar medium. It is pointed out that interstellar L-alpha and L-beta lines may not have purely Lorentzian profiles if high-velocity H I is a widespread phenomenon.

  13. General features

    SciTech Connect

    Wallace, R.E.

    1990-01-01

    The San Andreas fault system, a complex of faults that display predominantly large-scale strike slip, is part of an even more complex system of faults, isolated segments of the East Pacific Rise, and scraps of plates lying east of the East Pacific Rise that collectively separate the North American plate from the Pacific plate. This chapter briefly describes the San Andreas fault system, its setting along the Pacific Ocean margin of North America, its extent, and the patterns of faulting. Only selected characteristics are described, and many features are left for depictions on maps and figures.

  14. Astronomy (communication arising): black holes, fleas and microlithography.

    PubMed

    Skinner, Gerry; Gorenstein, Paul

    2003-11-20

    Fresnel lenses allow almost perfect imaging in widely different circumstances, but their focus is perfect only for a single wavelength. Wang et al. have shown how the effective bandpass may be widened for X-ray microscopy by using a compound diffractive/refractive lens near to an absorption edge. A compound lens has also been proposed for high-energy astronomy, working well above all absorption edges. Although the scale is very different, we point out here that the principle is the same. Ever since Galileo constructed an astronomical telescope that he was able to reconfigure to study fleas and gnats, astronomy and microscopy have relied on optics that are closely related, but different in detail.

  15. Pedunculated solitary fibrous tumours arising from the pleura.

    PubMed

    Poyraz, A; Kilic, D; Hatipoglu, A; Bakirci, T; Bilezikci, B

    2006-09-01

    Solitary fibrous tumour (SFT) is one of the rare tumours which arise from visceral pleura. Klemperer and Rabin first described SFT as a distinct clinical entity among primary pleural tumoUrs in 1931. Approximately 820 cases have been reported in literature to date. The management of patients with SFT is complete resection of the tumour and follow up of the patient to detect any possible late recurrence. In the present paper, we report two cases of pedunculated solitary fibrous tumours of the pleura that appeared as a wandering chest nodule to which surgical resection undertaken at our hospital. The aim is to summarise our experience in the management of solitary fibrous tumour.

  16. Solitary fibrous tumor arising from the sphenoid sinus.

    PubMed

    Takasaki, Kenji; Watanabe, Takeshi; Hayashi, Tomayoshi; Kinoshita, Naoe; Kumagami, Hidetaka; Takahashi, Haruo

    2009-01-01

    Solitary fibrous tumor (SFT) is an uncommon neoplasm that usually arises from the pleura. To our knowledge, only 30 cases of SFTs in the nasal cavity and paranasal sinuses have been reported in the literature. We describe an SFT that arose from the right sphenoid sinus and extended to the nasal cavity and epipharynx. The tumor was completely removed by endoscopic sinus surgery without complication. The patient is taking an uneventful course without any evidence of recurrence of the disease 8 months after surgery now.

  17. Dealing with uncertainty arising out of probabilistic risk assessment

    SciTech Connect

    Solomon, K.A.; Kastenberg, W.E.; Nelson, P.F.

    1984-03-01

    In addressing the area of safety goal implementation, the question of uncertainty arises. This report suggests that the Nuclear Regulatory Commission (NRC) should examine how other regulatory organizations have addressed the issue. Several examples are given from the chemical industry, and comparisons are made to nuclear power risks. Recommendations are made as to various considerations that the NRC should require in probabilistic risk assessments in order to properly treat uncertainties in the implementation of the safety goal policy. 40 references, 7 figures, 5 tables.

  18. Surprises and pitfalls arising from (pseudo)symmetry

    PubMed Central

    Zwart, Peter H.; Grosse-Kunstleve, Ralf W.; Lebedev, Andrey A.; Murshudov, Garib N.; Adams, Paul D.

    2008-01-01

    It is not uncommon for protein crystals to crystallize with more than a single molecule per asymmetric unit. When more than a single molecule is present in the asymmetric unit, various pathological situations such as twinning, modulated crystals and pseudo translational or rotational symmetry can arise. The presence of pseudosymmetry can lead to uncertainties about the correct space group, especially in the presence of twinning. The background to certain common pathologies is presented and a new notation for space groups in unusual settings is introduced. The main concepts are illustrated with several examples from the literature and the Protein Data Bank. PMID:18094473

  19. Retroesophageal subclavian artery aneurysm arising from Kommerell's diverticulum.

    PubMed

    Sala, F; Bouillane, P J; Francisci, M P; Diaz, F; Lena, P; Kreitmann, P; Batt, M

    2001-11-01

    This report describes a novel technique used for management of retroesophageal subclavian artery aneurysm arising from Kommerell's diverticulum. The procedure consists of endoaortic exclusion of the aneurysmal neck, using a prosthetic patch after sternotomy during circulatory arrest, and antegrade cold blood cerebroplegia. The advantages of this technique are avoidance of hemorrhagic complications during clamping of the aneurysmal neck, limiting of the extent of dissection of the aortic arch, and elimination of the risk of inadvertent left recurrent nerve paralysis. Antegrade cold blood cerebroplegia provides good cerebral protection and decreases the duration and consequences of extracorporeal circulation.

  20. Endoscopic resection of pleomorphic adenoma arising in the nasopharynx.

    PubMed

    Roh, Jong-Lyel; Jung, Bong Jin; Rha, Ki Sang; Park, Chan Ii

    2005-08-01

    Pleomorphic adenoma is the commonest benign tumor of the salivary glands. It has rarely been reported arising in the nasopharynx. A pleomorphic adenoma originating from the left lateral wall of the nasopharynx was found in a 61-year-old female who presented with nasal obstruction and intermittent epistaxis. It was successfully removed by combined transnasal and transoral surgery under endoscopic visualization. Endoscope-guided surgery may be helpful for the complete resection of benign nasopharyngeal tumors whilst minimizing injury to the Eustachian tube openings or velopharynx.

  1. Renal cell carcinoma arising in ipsilateral duplex system.

    PubMed

    Mohan, Harsh; Kundu, Reetu; Dalal, Usha

    2014-09-01

    Congenital anomalies of the kidney and urinary tract are common and include a wide anatomic spectrum. Duplex systems are one of the more common renal anomalies, with the majority being asymptomatic. Little is known about the molecular pathogenesis of these anomalies; however, certain causative genes have been implicated. The finding of renal cell carcinoma arising in a kidney with the duplication of pelvicalyceal system and ureters, as in the present case, is uncommon. The association between a duplex system and renal cell carcinoma may be more than a coincidence, requiring a deeper insight and further elucidation. PMID:26328175

  2. QSO Metal Absorption Systems at High Redshift and the Signature of Hierarchical Galaxy Formation

    NASA Astrophysics Data System (ADS)

    Rauch, Michael; Haehnelt, Martin G.; Steinmetz, Matthias

    1997-05-01

    In a hierarchical cosmogony, galaxies build up by continuous merging of smaller structures. At z = 3, the matter content of a typical present-day galaxy is dispersed over several individual clumps embedded in sheetlike structures, often aligned along filaments. We have used hydrodynamical simulations to investigate the spatial distribution and absorption properties of metal-enriched gas in such regions of ongoing galaxy formation. The metal and hydrogen absorption features produced by the collapsing structures closely resemble observed QSO absorption systems over a wide range in H I column density. Strong C II and Si IV absorption occurs for lines of sight passing the densest regions close to the center of the protogalactic clumps, while C IV is a good tracer of the prominent filamentary structures and O VI becomes the strongest absorption feature for lines of sight passing through low-density regions far away from fully collapsed objects. The observed column density ratios of the different ionic species at z = 3 can be well reproduced if a mean metallicity [Z/H] = -2.5, relative abundances as found in metal-poor stars, a UV background with intensity J-22 = 3 at the Lyman limit, and either a power-law spectrum (J ~ ν-1.5) or the spectral shape proposed by Haardt & Madau are assumed. The observed scatter in [C/H] is about a magnitude larger than that in the simulations, which suggests an inhomogeneous metal distribution. Observed and simulated Doppler parameter distributions of H I and C IV absorption lines are in good agreement, which indicates that shock heating due to gravitational collapse is a second important heating agent in addition to photoionization heating. The large velocity spreads seen in some C IV systems may be due to the occasional alignments of the observer's line of sight with expanding large-scale filaments. Both high-ionization multicomponent heavy-element absorbers and damped Lyα systems can arise from groups of moderately sized protogalactic

  3. [Carbohydrate absorption and malabsorption (author's transl)].

    PubMed

    Caspary, W F

    1977-06-01

    Starch is digested intraluminally by alpha-amylase to maltose, maltotriose, and alpha-limit dextrins. These products, as well as the disaccharides sucrose and lactose, undergo enzymatic hydrolysis to monosaccharides at the brush border surface. The monosaccharides enter the absorbing cell by specific transport mechanisms ("carriers"). Primary carbohydrate (CH) intolerance is characterized by the congenital or acquired absence of individual brush border enzymes or of monosaccharide "carriers" without morphologic abnormalities of the intestinal villus: lactose, sucrose and trehalose intolerance and glucose-galactose malabsorption (brush border diseases). Secondary CH intolerance arises when surface digestion and absorption are reduced due to structural changes of the intestinal mucosa: e.g., decrease or absence of villi with sprue and reduction of the absorbing surface with intestinal resection. Watery diarrhea is the lead symptom. Many drugs delay or interfere with CH absorption. This action may be viewed either as an unwanted side effect or as a welcome therapeutic principle.

  4. O VI absorption in interstellar cloud surfaces

    NASA Technical Reports Server (NTRS)

    Cowie, L. L.; Jenkins, E. B.; Songaila, A.; York, D. G.

    1979-01-01

    The velocity profiles of O VI absorption lines of 24 stars, observed in early Copernicus surveys, have been compared with the line profiles of Si III (1206.51 A) and N II (1083.99 A). The velocity structures of the O VI lines appear to be correlated with those of the material in the lower ionization stages. It is argued that the O VI absorption arises in the coronal gas of the conductive interface between hot gas, responsible for extended, soft X-ray emission, and cooler interstellar clouds. The velocity broadening of both sets of lines is attributed to motions of the cloud surfaces induced by pressure fluctuations in the interstellar medium.

  5. Quasar Absorption Studies

    NASA Technical Reports Server (NTRS)

    Mushotzky, Richard (Technical Monitor); Elvis, Martin

    2004-01-01

    The aim of the proposal is to investigate the absorption properties of a sample of inter-mediate redshift quasars. The main goals of the project are: Measure the redshift and the column density of the X-ray absorbers; test the correlation between absorption and redshift suggested by ROSAT and ASCA data; constrain the absorber ionization status and metallicity; constrain the absorber dust content and composition through the comparison between the amount of X-ray absorption and optical dust extinction. Unanticipated low energy cut-offs where discovered in ROSAT spectra of quasars and confirmed by ASCA, BeppoSAX and Chandra. In most cases it was not possible to constrain adequately the redshift of the absorber from the X-ray data alone. Two possibilities remain open: a) absorption at the quasar redshift; and b) intervening absorption. The evidences in favour of intrinsic absorption are all indirect. Sensitive XMM observations can discriminate between these different scenarios. If the absorption is at the quasar redshift we can study whether the quasar environment evolves with the Cosmic time.

  6. Accelerated Radiation-Damping for Increased Spin Equilibrium (ARISE)

    PubMed Central

    Huang, Susie Y.; Witzel, Thomas; Wald, Lawrence L.

    2008-01-01

    Control of the longitudinal magnetization in fast gradient echo sequences is an important factor enabling the high efficiency of balanced Steady State Free Precession (bSSFP) sequences. We introduce a new method for accelerating the return of the longitudinal magnetization to the +z-axis that is independent of externally applied RF pulses and shows improved off-resonance performance. The Accelerated Radiation damping for Increased Spin Equilibrium (ARISE) method uses an external feedback circuit to strengthen the Radiation Damping (RD) field. The enhanced RD field rotates the magnetization back to the +z-axis at a rate faster than T1 relaxation. The method is characterized in gradient echo phantom imaging at 3T as a function of feedback gain, phase, and duration and compared with results from numerical simulations of the Bloch equations incorporating RD. A short period of feedback (10ms) during a refocused interval of a crushed gradient echo sequence allowed greater than 99% recovery of the longitudinal magnetization when very little T2 relaxation has time to occur. Appropriate applications might include improving navigated sequences. Unlike conventional flip-back schemes, the ARISE “flip-back” is generated by the spins themselves, thereby offering a potentially useful building block for enhancing gradient echo sequences. PMID:18956463

  7. Primary retroperitoneal Müllerian adenocarcinoma arising from endometriosis.

    PubMed

    Tanaka, Kei; Kobayashi, Yoichi; Shibuya, Hiromi; Nishigaya, Yoshiko; Momomura, Mai; Matsumoto, Hironori; Iwashita, Mitsutoshi

    2014-06-01

    Primary retroperitoneal Müllerian adenocarcinoma (PRMA) is an extremely rare tumor and the cause remains unknown. We report a case of PRMA arising from endometriosis. A 52-year-old woman with a history of malignant lymphoma underwent a follow-up computed tomography scan, which revealed a retroperitoneal tumor. Immunohistochemical analysis of tumor resected during laparoscopic surgery showed adenocarcinoma positive for cytokeratin 7 and negative for cytokeratin 20. The patient had undergone hysterectomy and bilateral salpingo-oophorectomy 14 years ago for myoma uteri and endometrial cysts and was treated with estrogen-replacement therapy. The size of the tumor increased and laparotomy was performed. Histopathological examination showed adenocarcinoma resembling endometrial adenocarcinoma, which stained positive for cancer antigen 125, cancer antigen 19-9, estrogen receptor, and progesterone receptor immunohistochemically. The focus of the endometriosis was found at the edge of the tumor, and the stromal cells around the tumor cells were CD10 positive. The patient was diagnosed as having PRMA arising from endometriosis, and treated with adjuvant chemotherapy.

  8. Serous adenocarcinoma of the sigmoid mesentery arising in cystic endosalpingiosis.

    PubMed

    McCoubrey, A; Houghton, O; McCallion, K; McCluggage, W G

    2005-11-01

    This case report describes a Mullerian serous adenocarcinoma arising within a multoloculated cyst lined by ciliated serous-type epithelium located in the sigmoid mesentery. Twenty years previously the patient underwent a hysterectomy, bilateral salpingo-oophorectomy, and omentectomy. The ovaries contained bilateral serous cystadenofibromas, and multiple cysts lined by ciliated serous-type epithelium were present in the omentum. The resection specimen 20 years later contained a 14 cm multiloculated cyst located in the sigmoid mesentery. This was lined largely by benign ciliated serous-type epithelium but a focus of well differentiated serous adenocarcinoma projected into the lumen. Two further peritoneal cysts were present, both of which were lined by ciliated serous-type epithelium. There was a coincidental renal cell carcinoma. This is a unique case of multiple omental, peritoneal, and retroperitoneal cysts (classified as cystic endosalpingiosis), one of which developed a focus of serous adenocarcinoma. Although rarely serous adenocarcinomas, similar to those occurring within the ovary, arise in the retroperitoneum, this is the first reported occurrence in association with a pre-existing benign lesion.

  9. Myoepithelial carcinoma arising in recurrent pleomorphic adenoma in maxillary sinus.

    PubMed

    Gupta, Ashumi; Manipadam, Marie Therese; Michael, Rajiv

    2013-09-01

    Myoepithelial carcinoma is characterized by nearly exclusive myoepithelial differentiation and evidence of malignancy. It may arise de novo or in preexisting benign tumors including pleomorphic adenoma and benign myoepithelioma. A 39-year-old lady presented with painless progressive swelling on the right cheek and right side of palate. On surgery, there was a mass in right maxillary sinus which was surgically excised and diagnosed on histopathology as pleomorphic adenoma. Subsequently, there were two recurrences. The first recurrence was in the right maxilla after 2 years that was removed surgically and diagnosed as pleomorphic adenoma. One year later, she came with rapidly progressive swelling in bilateral cheeks and face. Intraoperatively, there was a large tumor in both maxillary sinuses with extensive local infiltration. Histologically, it was diagnosed as myoepithelial carcinoma. Carcinoma ex pleomorphic adenoma is usually a high grade malignancy. It occurs most commonly in parotid gland followed by submandibular glands, minor salivary glands and occasionally in sublingual gland. To the best of our knowledge, this is the first case of myoepithelial carcinoma arising in a recurrent pleomorphic adenoma in the maxillary sinus.

  10. Potassium emission absorption system. Topical report 12

    SciTech Connect

    Bauman, L.E.

    1995-04-01

    The Potassium Emission Absorption System is one of the advanced optical diagnostics developed at Mississippi State University to provide support for the demonstration of prototype-scale coal-fired combustion magnetohydrodynamic (MHD) electrical power generation. Intended for application in the upstream of an MHD flow, the system directly measures gas temperature and neutral potassium atom number density through spectroscopic emission absorption techniques. From these measurements the electron density can be inferred from a statistical equilibrium calculation and the electron conductivity in the MHD channel found by use of an electron mobility model. The instrument has been utilized for field test measurements on MHD facilities for almost a decade and has been proven to provide useful measurements as designed for MHD nozzle, channel, and diffuser test sections. The theory of the measurements, a system description, its capabilities, and field test measurement results are reported here. During the development and application of the instrument several technical issues arose which when addressed advanced the state of the art in emission absorption measurement. Studies of these issues are also reported here and include: two-wavelength measurements for particle-laden flows, potassium D-line far wing absorption coefficient, bias in emission absorption measurements arising from dirty windows and misalignments, non-coincident multiwavelength emission absorption sampling errors, and lineshape fitting for boundary layer flow profile information. Although developed for NLHD application, the instrument could be applied to any high temperature flow with a resonance line in the 300 to 800 nm range, for instance other types of flames, rocket plumes or low temperature plasmas.

  11. The Hubble Space Telescope quasar absorption line key project. II - Data calibration and absorption-line selection

    NASA Technical Reports Server (NTRS)

    Schneider, Donald P.; Hartig, George F.; Jannuzi, Buell T.; Kirhakos, Sofia; Saxe, David H.; Weymann, Ray J.; Bahcall, John N.; Bergeron, Jacqueline; Boksenberg, Alec; Sargent, W. L. W.

    1993-01-01

    We present the observational and data processing aspects of the Hubble Space Telescope Quasar Absorption Line Key Project. Topics discussed include the observational technique, calibration of the data, software that simulates the data, the automated procedure used to identify and characterize the absorption features, and the determination of the sensitivity limits of the survey.

  12. Absorption heat pump system

    DOEpatents

    Grossman, G.

    1982-06-16

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  13. Absorption heat pump system

    DOEpatents

    Grossman, Gershon

    1984-01-01

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  14. Compounds affecting cholesterol absorption

    NASA Technical Reports Server (NTRS)

    Hua, Duy H. (Inventor); Koo, Sung I. (Inventor); Noh, Sang K. (Inventor)

    2004-01-01

    A class of novel compounds is described for use in affecting lymphatic absorption of cholesterol. Compounds of particular interest are defined by Formula I: ##STR1## or a pharmaceutically acceptable salt thereof.

  15. Vertical Feature Mask Feature Classification Flag Extraction

    Atmospheric Science Data Center

    2013-03-28

      Vertical Feature Mask Feature Classification Flag Extraction This routine demonstrates extraction of the ... in a CALIPSO Lidar Level 2 Vertical Feature Mask feature classification flag value. It is written in Interactive Data Language (IDL) ...

  16. Solar selective absorption coatings

    DOEpatents

    Mahoney, Alan R.; Reed, Scott T.; Ashley, Carol S.; Martinez, F. Edward

    2004-08-31

    A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

  17. Solar selective absorption coatings

    DOEpatents

    Mahoney, Alan R.; Reed, Scott T.; Ashley, Carol S.; Martinez, F. Edward

    2003-10-14

    A new class of solar selective absorption coatings are disclosed. These coatings comprise a structured metallic overlayer such that the overlayer has a sub-micron structure designed to efficiently absorb solar radiation, while retaining low thermal emissivity for infrared thermal radiation. A sol-gel layer protects the structured metallic overlayer from mechanical, thermal, and environmental degradation. Processes for producing such solar selective absorption coatings are also disclosed.

  18. Optical absorption measurement system

    DOEpatents

    Draggoo, Vaughn G.; Morton, Richard G.; Sawicki, Richard H.; Bissinger, Horst D.

    1989-01-01

    The system of the present invention contemplates a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature.

  19. Malignant mixed tumors arising in salivary glands. I. Carcinomas arising in benign mixed tumors: a clinicopathologic study.

    PubMed

    LiVolsi, V A; Perzin, K H

    1977-05-01

    Forty-seven cases of malignant mixed tumor (MMT) arising in major and minor salivary glands are presented. By definition, all these lesions contained both a benign mixed tumor (BMT) as well as a malignant neoplasm, usually a poorly differentiated carcinoma. In some cases, the carcinoma developed in a previously untreated salivary gland mass which was known to have been present for many years, others evolved in a recurrent previously resected BMT and still others originated in a previously undetected BMT. Adverse prognostic factors included: carcinomatous involvement of the resection lines, perineural invasion, metastases in lymph nodes, and origin in a major salivary gland. Lesions arising in the palate had a better prognosis as compared to major salivary gland tumors. Some patients died of locally uncontrollable tumor and others because of metastatic disease. Local recurrences of MMT were seen frequently; 18 patients (38%) had a total of 32 local recurrences. Of patients followed five years or more, seven (35%) had died of tumor, 11 (55%) had no evidence of disease, and two (10%) had died of other causes. Prolonged follow-up is required because recurrences and death from tumor may be seen many years following the diagnosis of MMT. Recommendations for therapy are made. Criteria for differentiating MMT from recurrent BMT and from cylindromatous carcinoma are discussed.

  20. Spontaneous automaticity arising from a successfully ablated Mahaim fiber.

    PubMed

    Strohmer, Bernhard; Schernthaner, Christiana; Hwang, Chun

    2007-11-01

    The authors describe a 22-year-old woman with regular and irregular arrhythmias exhibiting left bundle branch block (LBBB) morphology at various heart rates. An atriofascicular fiber was diagnosed as the underlying mechanism for the antidromic reciprocating tachycardia. In addition, spontaneous automaticity of the Mahaim fiber was present during electrophysiologic study. The accessory pathway was ablated successfully, targeting a Mahaim potential at the supero-anterior tricuspid valve annulus. Relatively slow automatic rhythms with identical LBBB morphology were recorded immediately after ablation, as well as during long-term follow-up in a more sporadic and subclinical form. Abnormal automaticity arising from the distal portions of the remnant pathway was considered to be the origin of the slow ventricular rhythms in this peculiar case.

  1. Cesium vapor thermionic converter anomalies arising from negative ion emission

    NASA Astrophysics Data System (ADS)

    Rasor, Ned S.

    2016-08-01

    Compelling experimental evidence is given that a longstanding limit encountered on cesium vapor thermionic energy converter performance improvement and other anomalies arise from thermionic emission of cesium negative ions. It is shown that the energy that characterizes thermionic emission of cesium negative ions is 1.38 eV and, understandably, is not the electron affinity 0.47 eV determined for the photodetachment threshold of the cesium negative ion. The experimental evidence includes measurements of collector work functions and volt-ampere characteristics in quasi-vacuum cesium vapor thermionic diodes, along with reinterpretation of the classic Taylor-Langmuir S-curve data on electron emission in cesium vapor. The quantitative effects of negative ion emission on performance in the ignited, unignited, and quasi-vacuum modes of cesium vapor thermionic converter operation are estimated.

  2. Lymphatic vessels arise from specialized angioblasts within a venous niche.

    PubMed

    Nicenboim, J; Malkinson, G; Lupo, T; Asaf, L; Sela, Y; Mayseless, O; Gibbs-Bar, L; Senderovich, N; Hashimshony, T; Shin, M; Jerafi-Vider, A; Avraham-Davidi, I; Krupalnik, V; Hofi, R; Almog, G; Astin, J W; Golani, O; Ben-Dor, S; Crosier, P S; Herzog, W; Lawson, N D; Hanna, J H; Yanai, I; Yaniv, K

    2015-06-01

    How cells acquire their fate is a fundamental question in developmental and regenerative biology. Multipotent progenitors undergo cell-fate restriction in response to cues from the microenvironment, the nature of which is poorly understood. In the case of the lymphatic system, venous cells from the cardinal vein are thought to generate lymphatic vessels through trans-differentiation. Here we show that in zebrafish, lymphatic progenitors arise from a previously uncharacterized niche of specialized angioblasts within the cardinal vein, which also generates arterial and venous fates. We further identify Wnt5b as a novel lymphatic inductive signal and show that it also promotes the ‘angioblast-to-lymphatic’ transition in human embryonic stem cells, suggesting that this process is evolutionarily conserved. Our results uncover a novel mechanism of lymphatic specification, and provide the first characterization of the lymphatic inductive niche. More broadly, our findings highlight the cardinal vein as a heterogeneous structure, analogous to the haematopoietic niche in the aortic floor.

  3. Transversely isotropic poroelasticity arising from thin isotropic layers

    SciTech Connect

    Berryman, J.G.

    1996-11-01

    Percolation phenomena play central roles in the field of poroelasticity, where two distinct sets of percolating continua intertwine. A connected solid frame forms the basis of the elastic behavior of a poroelastic medium in the presence of confining forces, while connected pores permit a percolating fluid (if present) to influence the mechanical response of the system from within. The present paper discusses isotropic and anisotropic poroelastic media and establishes general formulas for the behavior of transversely isotropic poroelasticity arising from laminations of isotropic components. The Backus averaging method is shown to provide elementary means of constructing general formulas. The results for confined fluids are then compared with the more general Gassmann formulas that must be satisfied by any anisotropic poroelastic medium and found to be in complete agreement.

  4. Syringocystadenoma Papilliferum of the Scalp Arising from a Nevus Sebaceous

    PubMed Central

    Chandramouli, Mathangi; Sarma, Digvijay; Tejaswy, Kapil; Rodrigues, Gabriel

    2016-01-01

    Syringocystadenoma papilliferum (SCAP) is a rare, benign tumour with varied presentations that arises from the apocrine glands and at times can lead to a diagnostic dilemma. A 53-year-old male presented with a 40-year history of a scalp nodule and a recent 2-year change in its character, and a sanguinopurulent discharge. Examination revealed a 4 cm × 2 cm firm nodule upon left side of the scalp vertex, actively discharging pus and blood. No regional lymph nodes were noticeably palpable. Incision biopsy performed elsewhere showed evidence of a squamous cell carcinoma-in-situ. He underwent a wide local excision with a bilobed flap reconstruction. Histopathologically, the lesion was reported to be SCAP. On follow-up, the patient has since remained asymptomatic with an acceptable cosmetic recovery.

  5. Squamous carcinoma arising in a parotid Warthin's tumour.

    PubMed

    Allevi, Fabiana; Biglioli, Federico

    2014-01-01

    Warthin's tumour is the second most common benign neoplasm to affect the salivary glands. It virtually affects the sole parotid gland. A sudden increase in a tumour's size is usually due to a malignant transformation of the tumour. The transformation of the lymphoid stroma into malignant lymphoma is relatively common, while an epithelial malignancy is extremely rare. In this paper, the authors present a case of squamous cell carcinoma arising in Warthin's tumour. The patient underwent enucleoresection of the tumour. Intraoperative frozen section revealed the presence of a cystic component associated with the squamous cell carcinoma areas. In consideration of the result of the intraoperative consultation, the surgeons decided to enlarge the previous resection by removal of a 30×25 mm cuff from the surrounding parotid tissue. Close follow-up was carried out and 12 months after surgery there was no evidence of recurrence or metastatic neoplasm.

  6. Lymphadenoma arising in the parotid gland: a case report.

    PubMed

    Kwon, Ghee Young; Kim, Eo-Jin; Go, Jai Hyang

    2002-08-01

    We report a case of lymphadenoma arising in the parotid gland. A 53-year-old female patient presented with a mass in the parotid gland. Grossly, it was a well-demarcated solid mass measuring 3 cm in diameter. Microscopic examination revealed many cysts or duct-like structures in the background of the prominent lymphoid stroma, confirming a diagnosis of lymphadenoma. This particular case was thought to have arisen from an intraparotid lymph node. Lymphadenoma is a rare benign neoplasm of the salivary gland with partial resemblance to other salivary gland tumors, such as Warthin's tumor, cystadenoma, sebaceous lymphadenoma or mucoepidermoid carcinoma. Therefore proper recognition of this rare entity is warranted to avoid confusion in the diagnosis.

  7. Estimation of measurement uncertainty arising from manual sampling of fuels.

    PubMed

    Theodorou, Dimitrios; Liapis, Nikolaos; Zannikos, Fanourios

    2013-02-15

    Sampling is an important part of any measurement process and is therefore recognized as an important contributor to the measurement uncertainty. A reliable estimation of the uncertainty arising from sampling of fuels leads to a better control of risks associated with decisions concerning whether product specifications are met or not. The present work describes and compares the results of three empirical statistical methodologies (classical ANOVA, robust ANOVA and range statistics) using data from a balanced experimental design, which includes duplicate samples analyzed in duplicate from 104 sampling targets (petroleum retail stations). These methodologies are used for the estimation of the uncertainty arising from the manual sampling of fuel (automotive diesel) and the subsequent sulfur mass content determination. The results of the three methodologies statistically differ, with the expanded uncertainty of sampling being in the range of 0.34-0.40 mg kg(-1), while the relative expanded uncertainty lying in the range of 4.8-5.1%, depending on the methodology used. The estimation of robust ANOVA (sampling expanded uncertainty of 0.34 mg kg(-1) or 4.8% in relative terms) is considered more reliable, because of the presence of outliers within the 104 datasets used for the calculations. Robust ANOVA, in contrast to classical ANOVA and range statistics, accommodates outlying values, lessening their effects on the produced estimates. The results of this work also show that, in the case of manual sampling of fuels, the main contributor to the whole measurement uncertainty is the analytical measurement uncertainty, with the sampling uncertainty accounting only for the 29% of the total measurement uncertainty.

  8. Seven-effect absorption refrigeration

    DOEpatents

    DeVault, R.C.; Biermann, W.J.

    1989-05-09

    A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit. 1 fig.

  9. Seven-effect absorption refrigeration

    DOEpatents

    DeVault, Robert C.; Biermann, Wendell J.

    1989-01-01

    A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

  10. Htsc and Related Compounds Microwave Absorption Evolution in Multiple Remagnettzation Cycles

    NASA Astrophysics Data System (ADS)

    Shirokov, M. I.

    2000-09-01

    HTSC magnetomodulated microwave absorption hysteresis signal drift during sweep cycling, comparable to the hysteresis amplitude and disappearing at Tc, is found. It is related to Neel-type pair interactions, arising between reversing inhomogenuosly at the field scan turns shielding currents of weak links contours, widely distributed across superconductor surface. Microwave response selforganization features are observed: the signal nonmonotonous saturation, oscillation with decay around new equilibrium position, irregularities points, the shifts pronounced magnetic field anisotropy in isotropic ceramics and the signal high sensitivity to the `field-plane' angle inversion in single crystals (parity violation). The magnetic energy interplay between critical and precritical contours during critical state establishment seems to be the cause. Another picture arises in related magnetic compounds: no relaxation in oxide ferrites, if isolators, and the drift logarithmic-like decay in conducting ones. Strongly sulfur-doped 1-2-3-compounds show giant signal hysteresis only in the first cycle, indicating the magnetic phase. No signal drift was detected in nonsuperconducting oxide 1-2-3-compounds. This is an intrinsic HTSC property, being essential in microwave devices.

  11. Primary ovarian neuroendocrine tumor arising in association with a mature cystic teratoma: A case report.

    PubMed

    Orsi, Nicolas M; Menon, Mini

    2016-08-01

    Primary ovarian carcinoid tumors are exceptionally rare entities accounting for approximately 0.1% of all ovarian neoplasms. This report describes a primary ovarian neuroendocrine tumor arising in association with a mature cystic teratoma in a 65 year-old woman. Macroscopically, the unilateral adnexal tumor was composed of cystic, solid and mucinous elements which resolved into a dual component lesion histologically. The majority of the tumor displayed an organoid architecture with mild to moderate pleomorphism and no discernible mitotic activity, while approximately 10% consisted of sheets and groups of cells with highly pleomorphic nuclei, necrosis and occasional mitoses. Features of a mature cystic teratoma were seen very focally. Immunohistochemistry revealed strong, diffuse positivity for CD56 and synaptophysin. Chromogranin immunonegativity was noted and there was an absence of nuclear β-catenin accumulation. Ki-67 index was 10-12%. Although there is no established diagnostic framework for primary ovarian carcinoid tumors, this case was diagnosed as a well-differentiated neuroendocrine tumor, Grade 2 (intermediate grade), arising in association with a mature cystic teratoma/dermoid cyst. This case highlights the need to develop ovarian diagnostic criteria in this area. PMID:27508272

  12. Mutations associated with carcinomas arising from pleomorphic adenomas of the salivary glands.

    PubMed

    Yamamoto, Y; Kishimoto, Y; Virmani, A K; Smith, A; Vuitch, F; Albores-Saavedra, J; Gazdar, A F

    1996-08-01

    Pleomorphic adenoma (PA) is the most common benign tumor of salivary glands. Carcinomas in pleomorphic adenomas (CPAs) may arise by malignant transformation of the epithelial components of PAs. Occasionally, transitional zones containing cells with histological features intermediate between those of the benign PA and carcinomatous components of CPA are identified. After careful microdissection of archival microslides, the authors studied 12 cases of CPAs and their attendant adenomatous and transitional areas for mutations in the p53, RB, and K-ras genes, and at chromosomal loci 5q and 9p. The authors failed to find mutations in the K-ras gene or 9p locus. A relatively high rate of mutations (loss of heterozygosity [LOH] and microsatellite alterations) at the p53 gene were detected in CPAs (58%), and at somewhat lower frequencies at the RB gene (33%) and chromosomal location 5q (17%). Mutational frequency in the associated transitional and adenomatous areas were slightly lower than in the corresponding CPAs. No mutations were detected in adenomatous or transitional areas unless they also were present in the corresponding CPAs. Mutations of these three genes were absent in four cases of CPA, and in seven PAs without malignant change. These findings indicate that most CPAs arise from adenomas as the result of mutations in the three genes, especially p53. In addition, other, as yet unidentified genes may also be involved both in the development of PA and in its malignant progression to CPA. Mutational analysis of PAs may provide information of prognostic importance.

  13. Epidermoid Cyst Arising in the Buccal Mucosa: Case Report and Literature Review

    PubMed Central

    Costa, Fábio Wildson Gurgel; Chaves, Filipe Nobre; de Almeida, Stephanie; Alves, Ana Paula Negreiros Nunes; Patrocínio, Régia Maria do Socorro Vidal; Sousa, Fabrício Bitu; Pereira, Karuza Maria Alves

    2015-01-01

    Epidermoid cysts are benign subcutaneous lesions, and the large majority of these cysts affect the floor of the mouth; however, the buccal mucosa is not a usual site of occurrence. To date, only 5 articles have been published with 6 cases of epidermoid cysts arising in the buccal mucosa. Therefore, the aim of this study was to describe the clinical, histopathological and immunohistochemical features of a case of epidermoid cyst located in the buccal mucosa. To our knowledge, this is the first report of an oral epidermoid cyst describing an intense foreign body gigantocellular inflammatory reaction against epithelial keratin component. Although the usual diagnosis for epidermoid cysts is based on histopathological findings, this case report addresses novel information regarding to the immunohistochemical pattern that may be found in these lesions.

  14. Electromagnetically induced absorption in a three-resonator metasurface system

    PubMed Central

    Zhang, Xueqian; Xu, Ningning; Qu, Kenan; Tian, Zhen; Singh, Ranjan; Han, Jiaguang; Agarwal, Girish S.; Zhang, Weili

    2015-01-01

    Mimicking the quantum phenomena in metamaterials through coupled classical resonators has attracted enormous interest. Metamaterial analogs of electromagnetically induced transparency (EIT) enable promising applications in telecommunications, light storage, slow light and sensing. Although the EIT effect has been studied extensively in coupled metamaterial systems, excitation of electromagnetically induced absorption (EIA) through near-field coupling in these systems has only been sparsely explored. Here we present the observation of the EIA analog due to constructive interference in a vertically coupled three-resonator metamaterial system that consists of two bright and one dark resonator. The absorption resonance is one of the collective modes of the tripartite unit cell. Theoretical analysis shows that the absorption arises from a magnetic resonance induced by the near-field coupling of the three resonators within the unit cell. A classical analog of EIA opens up opportunities for designing novel photonic devices for narrow-band filtering, absorptive switching, optical modulation, and absorber applications. PMID:26023061

  15. EDITORIAL: Special issue featuring articles arising from the 11th High-Tech Plasma Processes Conference Special issue featuring articles arising from the 11th High-Tech Plasma Processes Conference

    NASA Astrophysics Data System (ADS)

    Bruggeman, Peter; Degrez, Gérard; Delplancke, Marie-Paule; Gleizes, Alain

    2011-05-01

    The 11th High-Tech Plasma Processes Conference (HTPP) was held in Brussels, Belgium, 27 June-2 July, 2010. HTPP started as a thermal plasma conference and gradually expanded to include low-temperature plasmas. The conference was founded by Jacques Amouroux and Pierre Fauchais, and aims to bring together different scientific communities to facilitate contacts between science, technology and industry, providing a platform for the exploration of elementary processes and applications in and by plasmas. The first HTPP was held in Odeillo, France, in 1990. Since then it has been held every other year in different European cities: Paris, Aachen, Athens, Strasbourg, Saint-Petersburg, Patras and Brussels. The 11th HTPP conference was attended by 125 participants from 19 countries. The program involved 14 invited talks, 34 contributed talks, 72 posters and a software demonstration and hands-on session for plasma modelling. The 12th HTPP conference will be held 24-28 June 2012, in Bologna, Italy. A larger part of the contributions to the 11th HTPP has been published in the Journal of Physics: Conference Series (JPCS) volume 275, 2011. All invited speakers and other contributors, as selected by the Steering, Scientific and Organizing Committee, were invited to submit a paper based on their contributions for this special issue which is peer reviewed by the journal. Both this special issue and the JPCS volume aim to bring the 11th HTPP to a wider audience. The publications are a nice example of the broad topic range of the conference. The JPCS volume contains papers covering fundamental aspects on radiative processes of thermal plasmas, modelling of thermal arcs and non-thermal RF plasma jets, plasma diagnostics including flow and heat flux measurements of thermal plasmas, radical density measurements and laser-induced breakdown spectroscopy. The applications-oriented contributions of the JPCS volume include plasma spraying, synthesis of (nano-sized) materials, surface modification, deposition of thin films and bio- and environmental applications. This special issue includes papers on modelling, covering arc and hollow cathode discharges, diffusion in the presence of magnetic fields, coupling techniques for particle-in-cell solvers and Stark broadening of He lines. Experimental work on plasma spraying, coatings and hydrocarbon conversion is also reported. In view of the diversity of the presented research at the conference, no attempt is made to give a full overview. We hope, nevertheless, that the readers enjoy reading the contributions and find them a useful reference for their own research. We are grateful to all participants for their valuable contributions and lively discussions. Our special thanks go to the members of the various committees for their important contributions to the success of the conference. We especially thank Joost van der Mullen who coordinated the scientific part of this conference. Financial support from the conference sponsors is gratefully acknowledged and we are particularly grateful to the Editorial Board of Journal of Physics D: Applied Physics for the publication of this special issue.

  16. Network Structures Arising from Spike-Timing Dependent Plasticity

    NASA Astrophysics Data System (ADS)

    Babadi, Baktash

    Spike-timing dependent plasticity (STDP), a widespread synaptic modification mechanism, is sensitive to correlations between presynaptic spike trains, and organizes neural circuits in functionally useful ways. In this dissertation, I study the structures arising from STDP in a population of synapses with an emphasis on the interplay between synaptic stability and Hebbian competition, explained in Chapter 1. Starting from the simplest description of STDP which relates synaptic modification to the intervals between pairs of pre- and postsynaptic spikes, I show in Chapter 2 that stability and Hebbian competition are incompatible in this class of "pair-based" STDP models, either when hard bounds or soft bounds are imposed to the synapses. In chapter 3, I propose an alternative biophysically inspired method for imposing bounds to synapses, i.e. introducing a small temporal shift in the STDP window. Shifted STDP overcomes the incompatibility of synaptic stability and competition and can implement both Hebbian and anti-Hebbian forms of competitive plasticity. In light of experiments the explored a variety of spike patterns, STDP models have been augmented to account for interactions between multiple pre- and postsynaptic action potentials. In chapter 4, I study the stability/competition interplay in three different proposed multi-spike models of STDP. I show that the "triplet model" leads to a partially steady-state distribution of synaptic weights and induces Hebbian competition. The "suppression model" develops a stable distribution of weights when the average weight is high and shows predominantly anti-Hebbian competition. The "NMDAR-based" model can lead to either stable or partially stable synaptic weight distribution and exhibits both Hebbian and anti-Hebbian competition, depending on the parameters. I conclude that multi-spike STDP models can produce radically different effects at the population level depending on how they implement multi-spike interactions

  17. The impact of alternate weekly collections on waste arisings.

    PubMed

    Williams, I D; Cole, C

    2013-02-15

    Residual waste is commonly collected separately from recyclable and organic materials. Different forms of collection and disposal are used internationally since regional or municipal authorities have to adapt to their own circumstances. Many authorities have adopted an alternate weekly collection (AWC) of residual waste and recyclables to force/encourage householders to recycle; however, the degree to which they achieve waste reduction has yet to be reliably quantified. This study reports on how the introduction of AWCs affects household waste arisings. The paper evaluates single and dual stream collection methods and compares their performance with the previous system. Household waste collection trials were conducted between March and June 2009 in England (Lichfield). The trials examined changes to frequency of collection, type of container issued, amounts of sorting required of residents, household participation and productivity levels. A survey of households was completed before any changes were implemented. The quantity of recyclates collected was examined for 2008/2009 and 2009/2010. The study showed that the AWC scheme positively impacted on recycling rates and household behaviour, with no adverse impacts on public participation, household waste arisings or the local environment. No public health problems were reported. Both trials saw an increase in the quantities of recyclates collected per household during the trial period compared to the same period of time in the previous year. The dual stream performed better than the single stream, collecting an average of 5.94 kg/hh/week compared to an average of 5.63 kg/hh/week. The single stream system showed a greater increase in the weight of material collected (0.53 kg/hh/week vs. 0.48 kg/hh/week). Participation and set-out rates showed an increase during the trial period. The single stream option (comingled materials in one container) outperformed the dual stream service. The reduction in costs and improved

  18. Nebular Hydrogen Absorption in the Ejecta of Eta Carinae

    NASA Technical Reports Server (NTRS)

    Gull, Theodore R.; Ishibashi, K.; Davidson, K.; Fisher, Richard R. (Technical Monitor)

    2000-01-01

    Space Telescope Imaging Spectrograph (STIS) observations of Eta Carinae and immediate ejecta reveal narrow Balmer absorption lines in addition to the nebular-scattered broad P-Cygni absorptions. The narrow absorption correlates with apparent disk structure that separates the two Homunculus lobes. We trace these features about half way up the Northern lobe until the scattered stellar Balmer line doppler-shifts redward beyond the nebular absorption feature. Three-dimensional data cubes, made by mapping the Homunculus at Balmer alpha and Balmer beta with the 52 x 0.1 arcsecond aperture and about 5000 spectral resolving power, demonstrate that the absorption feature changes slowly in velocity with nebular position. We have monitored the stellar Balmer alpha line profile of the central source over the past four years. The equivalent width of the nebular absorption feature changes considerably between observations. The changes do not correlate with measured brightness of Eta Carinae. Likely clumps of neutral hydrogen with a scale size comparable to the stellar disk diameter are passing through the intervening light path on the timescales less than several months. The excitation mechanism involves Lyman alpha radiation (possibly the Lyman series plus Lyman continuum) and collisions leading to populating the 2S metastable state. Before the electron can jump to the ground state by two photon emission (lifetime about 1/8 second), a stellar Balmer photon is absorbed and the electron shifts to an NP level. We see the absorption feature in higher Balmer lines, and but not in Paschen lines. Indeed we see narrow nebular Paschen emission lines. At present, we do not completely understand the details of the absorption. Better understanding should lead to improved insight of the unique conditions around Eta Carinae that leads to these absorptions.

  19. Development of Updated ABsorption SIMulation Software (ABSIM)

    SciTech Connect

    Yang, Zhiyao; Tang, Xin; Qu, Ming; Abdelaziz, Omar; Gluesenkamp, Kyle R

    2014-01-01

    ABsorption SIMulation, ABSIM, was developed for the simulation of absorption systems by The Oak Ridge National Laboratory during 1980s and 1990s. ABSIM provides a platform for users to investigate various cycle configurations and working fluids, to calculate their operating parameters, to predict their performance, and to compare them with each other on a uniform basis. ABSIM is indeed a very useful and accurate tool for researchers to investigate various absorption systems. However, it has not been well maintained: it is incompatible with recent operating systems; the interface needs improved user-friendliness, and the system needs better parameter setting and debugging tools to help achieve convergence. Therefore, it is highly needed to update and improve ABSIM. The paper presents recent efforts to improve ABSIM s compatibility with current operating systems, user interface, and analysis capabilities. The paper details the features and functions of the newly updated ABSIM software. The new ABSIM still uses the previously validated calculation engine of the old ABSIM. The new graphic user interfaces (GUI) were developed in Qt, which is an open source license GUI software based on C++. XML was used as the database for data storage in the new ABSIM. The new ABSIM has been designed to be easily learned and used. It has enhanced editing and construction functions, plus enhanced analysis features including parametric tables, plotting, property plots, and master panels for debugging. A single effect water/LiBr absorption system is used as a case study in this paper to illustrate the features, capabilities, and functions of the new ABSIM. This case study was actually an example system available in the old ABSIM. The new version of ABSIM will be continuously developed to include additional subroutines for the components in liquid desiccant systems. The new ABSIM will be available to public for free. The ultimate goal of the new ABSIM is to allow it to become a simulation

  20. Mycobacterium fortuitum infection arising in a new tattoo.

    PubMed

    Philips, Rebecca C; Hunter-Ellul, Lindsey A; Martin, Julie E; Wilkerson, Michael G

    2014-06-01

    We report an uncommon case of a cutaneous infection with Mycobacterium fortuitum arising in a new tattoo. A 29-year-old man presented with a several month history of a non-pruritic papular eruption within a tattoo; the papules developed 1-to-2 weeks after the tattoo procedure. He denied similar symptoms with previous tattoos. He had been treated unsuccessfully with cephalexin. Histopathologic examination revealed perifollicular chronic and granulomatous inflammation, consistent with chronic folliculitis. Acid-fast bacilli culture identified Mycobacterium fortuitum complex. The patient was treated with a 2-month course of oral trimethoprim-sulfamethoxazole (160mg/800mg twice daily) and ciprofloxacin (250 mg twice daily), with clinical improvement at follow up after three weeks of the antibiotic regimen. Rapidly growing mycobacteria have emerged as a cause of tattoo-associated cutaneous infection in recent years. Diagnosis and treatment can be difficult without clinical suspicion. M. fortuitum and other rapidly growing mycobacteria should be considered in the differential diagnosis of tattoo-associated dermatologic complications. PMID:24945647

  1. A Stochastic Problem Arising in the Storage of Radioactive Waste

    SciTech Connect

    Williams, M.M.R.

    2004-07-15

    Nuclear waste drums can contain a collection of radioactive components of uncertain activity and randomly dispersed in position. This implies that the dose-rate at the surface of different drums in a large assembly of similar drums can have significant variations according to the physical makeup and configuration of the waste components. The present paper addresses this problem by treating the drum, and its waste, as a stochastic medium. It is assumed that the sources in the drum contribute a dose-rate to some external point. The strengths and positions are chosen by random numbers, the dose-rate is calculated and, from several thousand realizations, a probability distribution for the dose-rate is obtained. It is shown that a very close approximation to the dose-rate probability function is the log-normal distribution. This allows some useful statistical indicators, which are of environmental importance, to be calculated with little effort.As an example of a practical situation met in the storage of radioactive waste containers, we study the problem of 'hotspots'. These arise in drums in which most of the activity is concentrated on one radioactive component and hence can lead to the possibility of large surface dose-rates. It is shown how the dose-rate, the variance, and some other statistical indicators depend on the relative activities on the sources. The results highlight the importance of such hotspots and the need to quantify their effect.

  2. Contribution to irradiation creep arising from gas-driven bubbles

    SciTech Connect

    Woo, C.H.; Garner, F.A.

    1998-03-01

    In a previous paper the relationship was defined between void swelling and irradiation creep arising from the interaction of the SIPA and SIG creep-driven deformation and swelling-driven deformation was highly interactive in nature, and that the two contributions could not be independently calculated and then considered as directly additive. This model could be used to explain the recent experimental observation that the creep-swelling coupling coefficient was not a constant as previously assumed, but declined continuously as the swelling rate increased. Such a model thereby explained the creep-disappearance and creep-damping anomalies observed in conditions where significant void swelling occurred before substantial creep deformation developed. At lower irradiation temperatures and high helium/hydrogen generation rates, such as found in light water cooled reactors and some fusion concepts, gas-filled cavities that have not yet exceeded the critical radius for bubble-void conversion should also exert an influence on irradiation creep. In this paper the original concept is adapted to include such conditions, and its predictions then compared with available data. It is shown that a measurable increase in the creep rate is expected compared to the rate found in low gas-generating environments. The creep rate is directly related to the gas generation rate and thereby to the neutron flux and spectrum.

  3. Giant solitary fibrous tumor arising from greater omentum.

    PubMed

    Zong, Liang; Chen, Ping; Wang, Guang-Yao; Zhu, Qun-Shan

    2012-11-28

    Extrathoracic solitary fibrous tumors (SFTs) have been described at almost every anatomic location of human body, but reports of SFT in the abdominal cavity are rare. We herein present a rare case of SFT originating from greater omentum. Computed tomography revealed a 15.8 cm × 21.0 cm solid mass located at superior aspect of stomach. Open laparotomy confirmed its mesenchymal origin. Microscopically, its tissue was composed of non-organized and spindle-shaped cells exhibiting atypical nuclei, which were divided up by branching vessel and collagen bundles. Immunohistochemical staining showed that this tumor was negative for CD117, CD99, CD68, cytokeratin, calretinin, desmin, epithelial membrane antigen, F8 and S-100, but positive for CD34, bcl-2, α-smooth muscle actin and vimentin. The patient presented no evidence of recurrence during follow-up. SFT arising from abdominal cavity can be diagnosed by histological findings and immunohistochemical markers, especially for CD34 and bcl-2 positive cases.

  4. Solitary fibrous tumors arising in abdominal wall hernia sacs.

    PubMed

    Lee, J R; Hancock, S M; Martindale, R G

    2001-06-01

    Solitary fibrous tumor (SFT) of the peritoneum is an unusual spindle-cell neoplasm. SFT was originally described in the pleura; however it is now diagnosed in multiple extrathoracic sites. Most believe that the tumor is of mesenchymal origin and should be classified as a variant of fibroma. SFT of the pleura and peritoneum have also been called fibrous mesothelioma, and the cell of origin is felt to be a pluripotential submesothelial mesenchymal cell. Primary tumors arising in hernia sacs are rare, and we report on two patients with hernia SFT. The first is a 67-year-old man who had a diffusely thickened distal left inguinal hernia sac. Within the sac was copious myxoid material mimicking pseudomyxoma peritonei. Herniorrhaphy and orchiectomy were performed. The second is a 44-year-old woman with a midepigastric mass attached to a ventral hernia. Wide local excision was performed. Both tumors demonstrated plump spindle cells, one with myxoid background and the other with keloidal collagen. Calretinin immunostaining was positive in both tumors, whereas CD34 was negative. This suggests tumor origin from a submesothial pluripotential cell that maintains potential for mesothelial differentiation. Surgical excision is the treatment of choice with the degree of resectability being a powerful predictor of outcome.

  5. Proprioceptive recalibration arises slowly compared to reach adaptation.

    PubMed

    Zbib, Basel; Henriques, Denise Y P; Cressman, Erin K

    2016-08-01

    When subjects reach in a novel visuomotor environment (e.g. while viewing a cursor representing their hand that is rotated from their hand's actual position), they typically adjust their movements (i.e. bring the cursor to the target), thus reducing reaching errors. Additionally, research has shown that reaching with altered visual feedback of the hand results in sensory changes, such that proprioceptive estimates of hand position are shifted in the direction of the visual feedback experienced (Cressman and Henriques in J Neurophysiol 102:3505-3518, 2009). This study looked to establish the time course of these sensory changes. Additionally, the time courses of implicit sensory and motor changes were compared. Subjects reached to a single visual target while seeing a cursor that was either aligned with their hand position (50 trials) or rotated 30° clockwise relative to their hand (150 trials). Reach errors and proprioceptive estimates of felt hand position were assessed following the aligned reach training trials and at seven different times during the rotated reach training trials by having subjects reach to the target without visual feedback, and provide estimates of their hand relative to a visual reference marker, respectively. Results revealed a shift in proprioceptive estimates throughout the rotated reach training trials; however, significant sensory changes were not observed until after 70 trials. In contrast, results showed a greater change in reaches after a limited number of reach training trials with the rotated cursor. These findings suggest that proprioceptive recalibration arises more slowly than reach adaptation.

  6. Sparse Gamma Rhythms Arising through Clustering in Adapting Neuronal Networks

    PubMed Central

    Kilpatrick, Zachary P.; Ermentrout, Bard

    2011-01-01

    Gamma rhythms (30–100 Hz) are an extensively studied synchronous brain state responsible for a number of sensory, memory, and motor processes. Experimental evidence suggests that fast-spiking interneurons are responsible for carrying the high frequency components of the rhythm, while regular-spiking pyramidal neurons fire sparsely. We propose that a combination of spike frequency adaptation and global inhibition may be responsible for this behavior. Excitatory neurons form several clusters that fire every few cycles of the fast oscillation. This is first shown in a detailed biophysical network model and then analyzed thoroughly in an idealized model. We exploit the fact that the timescale of adaptation is much slower than that of the other variables. Singular perturbation theory is used to derive an approximate periodic solution for a single spiking unit. This is then used to predict the relationship between the number of clusters arising spontaneously in the network as it relates to the adaptation time constant. We compare this to a complementary analysis that employs a weak coupling assumption to predict the first Fourier mode to destabilize from the incoherent state of an associated phase model as the external noise is reduced. Both approaches predict the same scaling of cluster number with respect to the adaptation time constant, which is corroborated in numerical simulations of the full system. Thus, we develop several testable predictions regarding the formation and characteristics of gamma rhythms with sparsely firing excitatory neurons. PMID:22125486

  7. Can CP violation arise solely from the gauge sector

    SciTech Connect

    London, D. )

    1992-05-01

    I consider the possibility that the Cabibbo-Kobayashi-Maskawa matrix is real, and that {vert bar}{epsilon}{vert bar}, the {ital CP}-violating parameter in the kaon system, is due indirectly to the existence of anomalous three-gauge-boson couplings which violate {ital CP}. Through these anomalous couplings, {ital CP}-violating interaictions of the {ital W} and quarks can be generated at one loop. The imaginary part of the {ital K}{sup 0-}{ital K{bar 0}} mixing box diagram is calculated using these effective {ital CP}-violating {ital W}-quark couplings. (This is a subset of all two-loop contributions to {vert bar}{epsilon}{vert bar}.) It is found that the values of the anomalous three-gauge-boson couplings required to reproduce the measured value of {vert bar}{epsilon}{vert bar} exceed their unitarity bounds. Thus, this scheme fails, offering compelling evidence that {ital CP} violation cannot arise solely from the gauge sector.

  8. Sound radiation quantities arising from a resilient circular radiator.

    PubMed

    Aarts, Ronald M; Janssen, Augustus J E M

    2009-10-01

    Power series expansions in ka are derived for the pressure at the edge of a radiator, the reaction force on the radiator, and the total radiated power arising from a harmonically excited, resilient, flat, circular radiator of radius a in an infinite baffle. The velocity profiles on the radiator are either Stenzel functions (1-(sigma/a)2)n, with sigma the radial coordinate on the radiator, or linear combinations of Zernike functions Pn(2(sigma/a)2-1), with Pn the Legendre polynomial of degree n. Both sets of functions give rise, via King's integral for the pressure, to integrals for the quantities of interest involving the product of two Bessel functions. These integrals have a power series expansion and allow an expression in terms of Bessel functions of the first kind and Struve functions. Consequently, many of the results in [M. Greenspan, J. Acoust. Soc. Am. 65, 608-621 (1979)] are generalized and treated in a unified manner. A foreseen application is for loudspeakers. The relation between the radiated power in the near-field on one hand and in the far field on the other is highlighted.

  9. Primary seminoma arising in the middle mediastinum: A case report

    PubMed Central

    XU, JING; ZHAO, JINGLAN; GENG, SHAOQING; WANG, QI; WANG, PENGFEI; ZHANG, CHUNLING; ZHU, XIONGZENG; JI, YOUXIN

    2016-01-01

    Primary mediastinal seminoma often occurs in the anterior mediastinum of young males. It is unusual for the tumor to originate in the middle or posterior mediastinum, and such cases have rarely been reported in the English literature. The present study reports the case of a 52-year-old man with a 3.0-cm primary seminoma arising in the middle mediastinum. The patient presented with the symptoms of cough and chest tightness. Fluorine-18 fluorodeoxyglucose-positron emission tomography (18F-FDG-PET) scans revealed unique abnormal FDG uptake in the middle mediastinum. A mediastinoscopy was performed and integral excision was found to be difficult. A biopsy was performed and the histological examination revealed a primary seminoma. Following 4 cycles of a standard bleomycin, etoposide and cisplatin chemotherapy regimen, and chest irradiation at a total dose of 40 Gy in 20 fractions, the tumor exhibited a partial response, decreasing in size, and FDG uptake was no longer observed on 18F-FDG-PET scan. The last follow-up date was April 2016 and the patient has remained disease-free for 20 months. PMID:27347149

  10. Clear cell carcinoma arising from a uterus-like mass.

    PubMed

    Nakakita, Baku; Abiko, Kaoru; Mikami, Yoshiki; Kido, Aki; Baba, Tsukasa; Yoshioka, Yumiko; Yamaguchi, Ken; Matsumura, Noriomi; Konishi, Ikuo

    2014-11-01

    A uterus-like mass is an extrauterine mass with a cavity lined by endometrial tissue and a smooth muscle layer resembling the uterine corpus. It is a rare condition of unknown histogenesis. Herein, we describe a case of clear cell carcinoma arising from a uterus-like mass located in the retroperitoneal space. The patient, a 67-year old nulliparous woman, had been followed with the diagnosis of an ovarian endometriotic cyst for 14 years until ultrasonography and magnetic resonance imaging (MRI) demonstrated an enlargement of the cystic mass with a thickened irregular wall. Suspicion of malignant transformation prompted us to excise the lesion. At laparotomy, the uterus and right ovary appeared normal, and a mass measuring 8 cm was identified in the retroperitoneal space without any connection to the uterus. Grossly, the removed mass was composed of a cyst filled with blackish-brownish fluid and a thick wall resembling uterine myometrium. Microscopically, endometrial tissue inside the cyst, which was diffusely lined by clear cell carcinoma, was identified. Although the histogenesis of a uterus-like mass remains unclear, this case indicates that malignant tumors may occur from a uterus-like mass through the pathway similar to the carcinogenesis of endometriosis-related ovarian neoplasms.

  11. The complex spectrum of forensic issues arising from obesity.

    PubMed

    Byard, Roger W

    2012-12-01

    The increasing numbers of obese and morbidly obese individuals in the community are having a direct effect on forensic facilities. In addition to having to install more robust equipment for handling large bodies, the quality of autopsy examinations may be reduced by the physical difficulties that arise in trying to position bodies correctly so that normal examinations can proceed. Accelerated putrefaction is often an added complication. Metabolic disturbances resulting from obesity increase susceptibility to a range of conditions that are associated with sudden and unexpected death, and surgery may have increased complications. The rates of a number of different malignancies, including lymphoma, leukemia, melanoma and multiple myeloma, and carcinomas of the esophagus, stomach, colon, gallbladder, thyroid, prostate, breast and endometrium, are increased. In addition, obese individuals have higher rates of diabetes mellitus, and sepsis. The unexpected collapse of an obese individual should raise the possibility of a wide range of conditions, many of which may be more difficult to demonstrate at autopsy than in an individual with a normal body mass index. Although sudden cardiac death due to cardiomegaly, pulmonary thromboembolism, or ischemic heart disease may be the most probable diagnosis in an unexpected collapse, the range of possible underlying conditions is extensive and often only determinable after full postmortem examination.

  12. On Bounded Posets Arising from Quantum Mechanical Measurements

    NASA Astrophysics Data System (ADS)

    Dorninger, Dietmar; Länger, Helmut

    2016-10-01

    Let S be a set of states of a physical system. The probabilities p( s) of the occurrence of an event when the system is in different states s ∈ S define a function from S to [0, 1] called a numerical event or, more precisely, an S- probability. If one orders a set P of S-probabilities in respect to the order of functions, further includes the constant functions 0 and 1 and defines p' = 1 - p for every p ∈ P, then one obtains a bounded poset of S-probabilities with an antitone involution. We study these posets in respect to various conditions about the existence of the sum of certain functions within the posets and derive properties from these conditions. In particular, questions of relations between different classes of S-probabilities arising this way are settled, algebraic representations are provided and the property that two S-probabilities commute is characterized which is essential for recognizing a classical physical system.

  13. Exposures to asbestos arising from bandsawing gasket material.

    PubMed

    Fowler, D P

    2000-05-01

    A simulation of bandsawing sheet asbestos gasket material was performed as part of a retrospective exposure evaluation undertaken to assist in determining causation of a case of mesothelioma. The work was performed by bandsawing a chrysotile asbestos (80%)/neoprene gasket sheet with a conventional 16-inch woodworking bandsaw inside a chamber. Measurements of airborne asbestos were made using conventional area and personal sampling methods, with analysis of collected samples by transmission electron microscopy (TEM) and phase contrast microscopy (PCM). These were supplemented by qualitative scanning electron microscopy (SEM) examinations of some of the airborne particles collected on the filters. In contrast with findings from studies examining manual handling (installation and removal) of gaskets, airborne asbestos concentrations from this operation were found to be well above current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) (eight-hour time-weighted average [TWA]) and excursion limit (30-minute) standards. Although some "encapsulation" effect of the neoprene matrix was seen on the particles in the airborne dust, unencapsulated individual fiber bundles were also seen. Suggestions for the implications of the work are given. In summary, the airborne asbestos concentrations arising from this work were quite high, and point to the need for careful observation of common sense precautions when manipulation of asbestos-containing materials (even those believed to have limited emissions potential) may involved machining operations.

  14. Risk analysis for renewable energy projects due to constraints arising

    NASA Astrophysics Data System (ADS)

    Prostean, G.; Vasar, C.; Prostean, O.; Vartosu, A.

    2016-02-01

    Starting from the target of the European Union (EU) to use renewable energy in the area that aims a binding target of 20% renewable energy in final energy consumption by 2020, this article illustrates the identification of risks for implementation of wind energy projects in Romania, which could lead to complex technical implications, social and administrative. In specific projects analyzed in this paper were identified critical bottlenecks in the future wind power supply chain and reasonable time periods that may arise. Renewable energy technologies have to face a number of constraints that delayed scaling-up their production process, their transport process, the equipment reliability, etc. so implementing these types of projects requiring complex specialized team, the coordination of which also involve specific risks. The research team applied an analytical risk approach to identify major risks encountered within a wind farm project developed in Romania in isolated regions with different particularities, configured for different geographical areas (hill and mountain locations in Romania). Identification of major risks was based on the conceptual model set up for the entire project implementation process. Throughout this conceptual model there were identified specific constraints of such process. Integration risks were examined by an empirical study based on the method HAZOP (Hazard and Operability). The discussion describes the analysis of our results implementation context of renewable energy projects in Romania and creates a framework for assessing energy supply to any entity from renewable sources.

  15. Novel ethical dilemmas arising in geriatric clinical practice.

    PubMed

    Calleja-Sordo, Elisa Constanza; de Hoyos, Adalberto; Méndez-Jiménez, Jorge; Altamirano-Bustamante, Nelly F; Islas-Andrade, Sergio; Valderrama, Alejandro; García-Peña, Carmen; Altamirano-Bustamante, Myriam M

    2015-05-01

    The purpose of this study is to determine empirically the state of the art of the medical care, when healthcare personal is confronted with ethical dilemmas related with the care they give to the geriatric population. An observational, longitudinal, prospective and qualitative study was conducted by analyzing the correlation between healthcare personnel-patient relationship, and ethical judgments regarding dilemmas that arise in daily clinical practice with geriatric patients. Mexican healthcare personnel with current active practices were asked to write up an ethical dilemma that arose frequently or that had impacted their medical practice. From the narrative input, we were able to draw up a database with 421 dilemmas, and those corresponding to patients 60 years and older were selected (n = 54, 12.8 %). The axiological analysis of the narrative dilemmas of geriatric patients was made using dialectical empiricism. The axiological analysis values found most frequently were classified into three groups: the impact of healthcare, the roles of the physician, and refusal of therapy; the healthcare role of educator, caring for the patients' life and the risk of imminent death where the values found more often. The persistence and universality of certain dilemmas in geriatrics calls for awareness and requires a good training in the ethical discernment of these dilemmas. This would help to improve substantially the care and the life quality of this population. PMID:25185872

  16. Myoepithelioma arising from the buccal gland: histopathological and immunohistochemical studies.

    PubMed

    Sugiura, R; Kuyama, K; Utsunomiya, T; Morikawa, M; Fukumoto, M; Yamamoto, H

    2000-03-01

    A rare case of myoepithelioma of the buccal gland in a 54-year-old Japanese woman is reported. As the swelling exhibited a normal mucosal color and was relatively well defined, showing no ulcers, a benign salivary gland tumor was suspected upon clinical inspection. Microscopically, the parenchyma of the present case mainly consisted of plasmacytoid cells with round nuclei and eosinophilic cytoplasm, and partial spindle cells with eccentric nuclei. The stroma was composed of fibro-hyalinized or myxoid connective tissue that separated from the parenchyma. Immunohistochemically, the cytoplasm of the plasmacytoid and spindle cells was moderately positive for vimentin and GFAP, whereas the buccal gland adjacent to the tumor was negative for these antibodies. S-100 protein reactivity is strong for both types tumor cells. Actin reactivity was negative for both types of tumor cells, notwithstanding the fact that myoepithelial cells of the buccal gland were positively stained. Anti-cytokeratin reactivity was weak for both types of tumor cells in portions of the plexiform and solid areas; nevertheless, the buccal glands were moderately positive. These results suggest that neoplasmic myoepithelial cells exhibit abnormal differentiation and modification. There have been only two published reports of myoepithelioma arising from the buccal gland in the literature to date.

  17. Absorption heat pump system

    DOEpatents

    Grossman, Gershon; Perez-Blanco, Horacio

    1984-01-01

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  18. Laser Absorption by Over-Critical Plasmas

    NASA Astrophysics Data System (ADS)

    May, J.; Tonge, J.; Fiuza, F.; Fonseca, R. A.; Silva, L. O.; Mori, W. B.

    2015-11-01

    Absorption of high intensity laser light by matter has important applications to emerging sciences and technology, such as Fast Ignition ICF and ion acceleration. As such, understanding the underlying mechanisms of this absorption is key to developing these technologies. Critical features which distinguish the interaction of high intensity light - defined here as a laser field having a normalized vector potential greater than unity - are that the reaction of the material to the fields results in sharp high-density interfaces; and that the movement of the electrons is in general relativistic, both in a fluid and a thermal sense. The results of these features are that the absorption mechanisms are qualitatively distinct from those at lower intensities. We will review previous work, by our group and others, on the absorption mechanisms, and highlight current research. We will show that the standing wave structure of the reflected laser light is key to particle dynamics for normally incident lasers. The authors acknowledge the support of the Department of Energy under contract DE-NA 0001833 and the National Science Foundation under contract ACI 1339893.

  19. Molecular absorption in transition region spectral lines

    NASA Astrophysics Data System (ADS)

    Schmit, D. J.; Innes, D.; Ayres, T.; Peter, H.; Curdt, W.; Jaeggli, S.

    2014-09-01

    Aims: We present observations from the Interface Region Imaging Spectrograph (IRIS) of absorption features from a multitude of cool atomic and molecular lines within the profiles of Si IV transition region lines. Many of these spectral lines have not previously been detected in solar spectra. Methods: We examined spectra taken from deep exposures of plage on 12 October 2013. We observed unique absorption spectra over a magnetic element which is bright in transition region line emission and the ultraviolet continuum. We compared the absorption spectra with emission spectra that is likely related to fluorescence. Results: The absorption features require a population of sub-5000 K plasma to exist above the transition region. This peculiar stratification is an extreme deviation from the canonical structure of the chromosphere-corona boundary. The cool material is not associated with a filament or discernible coronal rain. This suggests that molecules may form in the upper solar atmosphere on small spatial scales and introduces a new complexity into our understanding of solar thermal structure. It lends credence to previous numerical studies that found evidence for elevated pockets of cool gas in the chromosphere. Movies associated to Figs. 1 and 2 are available in electronic form at http://www.aanda.org

  20. Nonlinear absorption of Alfven wave in dissipative plasma

    SciTech Connect

    Taiurskii, A. A. Gavrikov, M. B.

    2015-10-28

    We propose a method for studying absorption of Alfven wave propagation in a homogeneous non-isothermal plasma along a constant magnetic field, and relaxation of electron and ion temperatures in the A-wave. The absorption of a A-wave by the plasma arises due to dissipative effects - magnetic and hydrodynamic viscosities of electrons and ions and their elastic interaction. The method is based on the exact solution of two-fluid electromagnetic hydrodynamics of the plasma, which for A-wave, as shown in the work, are reduced to a nonlinear system of ordinary differential equations.

  1. Feature Extraction Based on Decision Boundaries

    NASA Technical Reports Server (NTRS)

    Lee, Chulhee; Landgrebe, David A.

    1993-01-01

    In this paper, a novel approach to feature extraction for classification is proposed based directly on the decision boundaries. We note that feature extraction is equivalent to retaining informative features or eliminating redundant features; thus, the terms 'discriminantly information feature' and 'discriminantly redundant feature' are first defined relative to feature extraction for classification. Next, it is shown how discriminantly redundant features and discriminantly informative features are related to decision boundaries. A novel characteristic of the proposed method arises by noting that usually only a portion of the decision boundary is effective in discriminating between classes, and the concept of the effective decision boundary is therefore introduced. Next, a procedure to extract discriminantly informative features based on a decision boundary is proposed. The proposed feature extraction algorithm has several desirable properties: (1) It predicts the minimum number of features necessary to achieve the same classification accuracy as in the original space for a given pattern recognition problem; and (2) it finds the necessary feature vectors. The proposed algorithm does not deteriorate under the circumstances of equal class means or equal class covariances as some previous algorithms do. Experiments show that the performance of the proposed algorithm compares favorably with those of previous algorithms.

  2. Absorption mode FTICR mass spectrometry imaging.

    PubMed

    Smith, Donald F; Kilgour, David P A; Konijnenburg, Marco; O'Connor, Peter B; Heeren, Ron M A

    2013-12-01

    Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power for molecular imaging experiments. This high mass resolving power ensures that closely spaced peaks at the same nominal mass are resolved for proper image generation. Typically higher magnetic fields are used to increase mass resolving power. However, a gain in mass resolving power can also be realized by phase correction of the data for absorption mode display. In addition to mass resolving power, absorption mode offers higher mass accuracy and signal-to-noise ratio over the conventional magnitude mode. Here, we present the first use of absorption mode for Fourier transform ion cyclotron resonance mass spectrometry imaging. The Autophaser algorithm is used to phase correct each spectrum (pixel) in the image, and then, these parameters are used by the Chameleon work-flow based data processing software to generate absorption mode "Datacubes" for image and spectral viewing. Absorption mode reveals new mass and spatial features that are not resolved in magnitude mode and results in improved selected ion image contrast.

  3. The Complete Ultraviolet Spectrum of the Archetypal "Wind-dominated" Quasar Mrk 231: Absorption and Emission from a High-speed Dusty Nuclear Outflow

    NASA Astrophysics Data System (ADS)

    Veilleux, S.; Meléndez, M.; Tripp, T. M.; Hamann, F.; Rupke, D. S. N.

    2016-07-01

    New near- and far-ultraviolet (NUV and FUV) Hubble Space Telescope spectra of Mrk 231, the nearest quasar known, are combined with ground-based optical spectra to study the remarkable dichotomy between the FUV and NUV-optical spectral regions in this object. The FUV emission-line features are faint, broad, and highly blueshifted (up to ˜7000 km s-1), with no significant accompanying absorption. In contrast, the profiles of the NUV absorption features resemble those of the optical Na i D, He i, and Ca ii H and K lines, exhibiting broad blueshifted troughs that overlap in velocity space with the FUV emission-line features and indicate a dusty, high-density and patchy broad absorption line (BAL) screen covering ˜90% of the observed continuum source at a distance ≲2-20 pc. The FUV continuum emission does not show the presence of any obvious stellar features and is remarkably flat compared with the steeply declining NUV continuum. The NUV (FUV) features and continuum emission have not varied significantly over the past ˜22 (3) years and are unresolved on scales ˜40 (170) pc. These results favor an active galactic nucleus origin for the NUV-FUV line and continuum emission. The observed FUV line emission is produced in the outflowing BAL cloud system, while the Balmer lines arise primarily from the standard broad line region seen through the dusty BAL screen. Our data are inconsistent with the recently proposed binary black hole model. We argue instead that Mrk 231 is the nearest example of weak-lined “wind-dominated” quasars with high Eddington ratios and geometrically thick (“slim”) accretion disks; these quasars are likely more common in the early universe.

  4. Lipids: Absorption and transport

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the hydrophobic nature of lipids, dietary fat is handled differently than protein or carbohydrate with respect with digestion and absorption. Dietary fats are broken down throughout the gastrointestinal system. A unique group of enzymes and cofactors allows this process to proceed in an eff...

  5. Absorption driven focus shift

    NASA Astrophysics Data System (ADS)

    Harrop, N.; Wolf, S.; Maerten, O.; Dudek, K.; Ballach, S.; Kramer, R.

    2016-03-01

    Modern high brilliance near infrared lasers have seen a tremendous growth in applications throughout the world. Increased productivity has been achieved by higher laser power and increased brilliance of lasers. Positive impacts on the performance and costs of parts are opposed to threats on process stability and quality, namely shift of focus position over time. A high initial process quality will be reduced by contamination of optics, eventually leading to a focus shift or even destruction of the optics. Focus analysis at full power of multi-kilowatt high brilliance lasers is a very demanding task because of high power densities in the spot and the high power load on optical elements. With the newly developed high power projection optics, the High-Power Micro-Spot Monitor High Brilliance (HP-MSM-HB) is able to measure focus diameter as low as 20 μm at power levels up to 10 kW at very low internal focus shift. A main driving factor behind thermally induced focus shift is the absorption level of the optical element. A newly developed measuring system is designed to determine the relative absorption level in reference to a gold standard. Test results presented show a direct correlation between absorption levels and focus shift. The ability to determine the absorption level of optical elements as well as their performance at full processing power before they are put to use, enables a high level of quality assurance for optics manufacturers and processing head manufacturers alike.

  6. Two-Phonon Absorption

    ERIC Educational Resources Information Center

    Hamilton, M. W.

    2007-01-01

    A nonlinear aspect of the acousto-optic interaction that is analogous to multi-photon absorption is discussed. An experiment is described in which the second-order acousto-optically scattered intensity is measured and found to scale with the square of the acoustic intensity. This experiment using a commercially available acousto-optic modulator is…

  7. Cholesterol Absorption and Metabolism.

    PubMed

    Howles, Philip N

    2016-01-01

    Inhibitors of cholesterol absorption have been sought for decades as a means to treat and prevent cardiovascular diseases (CVDs) associated with hypercholesterolemia. Ezetimibe is the one clear success story in this regard, and other compounds with similar efficacy continue to be sought. In the last decade, the laboratory mouse, with all its genetic power, has become the premier experimental model for discovering the mechanisms underlying cholesterol absorption and has become a critical tool for preclinical testing of potential pharmaceutical entities. This chapter briefly reviews the history of cholesterol absorption research and the various gene candidates that have come under consideration as drug targets. The most common and versatile method of measuring cholesterol absorption is described in detail along with important considerations when interpreting results, and an alternative method is also presented. In recent years, reverse cholesterol transport (RCT) has become an area of intense new interest for drug discovery since this process is now considered another key to reducing CVD risk. The ultimate measure of RCT is sterol excretion and a detailed description is given for measuring neutral and acidic fecal sterols and interpreting the results. PMID:27150091

  8. Obesity, the Endocannabinoid System, and Bias Arising from Pharmaceutical Sponsorship

    PubMed Central

    McPartland, John M.

    2009-01-01

    Background Previous research has shown that academic physicians conflicted by funding from the pharmaceutical industry have corrupted evidence based medicine and helped enlarge the market for drugs. Physicians made pharmaceutical-friendly statements, engaged in disease mongering, and signed biased review articles ghost-authored by corporate employees. This paper tested the hypothesis that bias affects review articles regarding rimonabant, an anti-obesity drug that blocks the central cannabinoid receptor. Methods/Principal Findings A MEDLINE search was performed for rimonabant review articles, limited to articles authored by USA physicians who served as consultants for the company that manufactures rimonabant. Extracted articles were examined for industry-friendly bias, identified by three methods: analysis with a validated instrument for monitoring bias in continuing medical education (CME); analysis for bias defined as statements that ran contrary to external evidence; and a tally of misrepresentations about the endocannabinoid system. Eight review articles were identified, but only three disclosed authors' financial conflicts of interest, despite easily accessible information to the contrary. The Takhar CME bias instrument demonstrated statistically significant bias in all the review articles. Biased statements that were nearly identical reappeared in the articles, including disease mongering, exaggerating rimonabant's efficacy and safety, lack of criticisms regarding rimonabant clinical trials, and speculations about surrogate markers stated as facts. Distinctive and identical misrepresentations regarding the endocannabinoid system also reappeared in articles by different authors. Conclusions The findings are characteristic of bias that arises from financial conflicts of interest, and suggestive of ghostwriting by a common author. Resolutions for this scenario are proposed. PMID:19333392

  9. Transversely isotropic elasticity and poroelasticity arising from thin isotropic layers

    SciTech Connect

    Berryman, J.G.

    1997-07-01

    Since the classic work of Postma [1955] and Backus [1962], much has been learned about elastic constants in vertical transversely isotropic (VTI) media when the anisotropy is due to fine layering of isotropic elastic materials. However, new results are still being discovered. For example, the P-wave anisotropy parameter c{sub 11}/c{sub 33} lies in the range 1/4 {<=} c{sub 11}/c{sub 33} {<=} <{lambda}+2{mu}><1/({lambda}+2{mu})>, when the layers are themselves composed of isotropic elastic materials with Lame constants {lambda} and {mu} and the vertical average of the layers is symbolized by <{center_dot}>. The lower bound corrects a result of Postma. For porous layers, a connected solid frame forms the basis of the elastic behavior of a poroelastic medium in the presence of confining forces, while connected pores permit a percolating fluid (if present) to influence the mechanical response of the system from within. For isotropic and anisotropic poroelastic media, we establish general formulas for the behavior of transversely isotropic poroelasticity arising from laminations of isotropic components. The Backus averaging method is shown to provide elementary means of constructing general formulas. The results for confined fluids are then compared with the more general Gassmann [1951] formulas that must be satisfied by any anisotropic poroelastic medium and found to be in complete agreement. Such results are important for applications to oil exploration using AVO (amplitude versus offset) since the presence or absence of a fluid component, as well as the nature of the fluid, is the critical issue and the ways in which the fluid influences seismic reflection data still need to be better understood.

  10. Urban surface water pollution problems arising from misconnections.

    PubMed

    Revitt, D Michael; Ellis, J Bryan

    2016-05-01

    The impacts of misconnections on the organic and nutrient loadings to surface waters are assessed using specific household appliance data for two urban sub-catchments located in the London metropolitan region and the city of Swansea. Potential loadings of biochemical oxygen demand (BOD), soluble reactive phosphorus (PO4-P) and ammoniacal nitrogen (NH4-N) due to misconnections are calculated for three different scenarios based on the measured daily flows from specific appliances and either measured daily pollutant concentrations or average pollutant concentrations for relevant greywater and black water sources obtained from an extensive review of the literature. Downstream receiving water concentrations, together with the associated uncertainties, are predicted from derived misconnection discharge concentrations and compared to existing freshwater standards for comparable river types. Consideration of dilution ratios indicates that these would need to be of the order of 50-100:1 to maintain high water quality with respect to BOD and NH4-N following typical misconnection discharges but only poor quality for PO4-P is likely to be achievable. The main pollutant loading contributions to misconnections arise from toilets (NH4-N and BOD), kitchen sinks (BOD and PO4-P) washing machines (PO4-P and BOD) and, to a lesser extent, dishwashers (PO4-P). By completely eliminating toilet misconnections and ensuring misconnections from all other appliances do not exceed 2%, the potential pollution problems due to BOD and NH4-N discharges would be alleviated but this would not be the case for PO4-P. In the event of a treatment option being preferred to solve the misconnection problem, it is shown that for an area the size of metropolitan Greater London, a sewage treatment plant with a Population Equivalent value approaching 900,000 would be required to efficiently remove BOD and NH4-N to safely dischargeable levels but such a plant is unlikely to have the capacity to deal

  11. Qualia Could Arise from Information Processing in Local Cortical Networks

    PubMed Central

    Orpwood, Roger

    2013-01-01

    Re-entrant feedback, either within sensory cortex or arising from prefrontal areas, has been strongly linked to the emergence of consciousness, both in theoretical and experimental work. This idea, together with evidence for local micro-consciousness, suggests the generation of qualia could in some way result from local network activity under re-entrant activation. This paper explores the possibility by examining the processing of information by local cortical networks. It highlights the difference between the information structure (how the information is physically embodied), and the information message (what the information is about). It focuses on the network’s ability to recognize information structures amongst its inputs under conditions of extensive local feedback, and to then assign information messages to those structures. It is shown that if the re-entrant feedback enables the network to achieve an attractor state, then the message assigned in any given pass of information through the network is a representation of the message assigned in the previous pass-through of information. Based on this ability the paper argues that as information is repeatedly cycled through the network, the information message that is assigned evolves from a recognition of what the input structure is, to what it is like, to how it appears, to how it seems. It could enable individual networks to be the site of qualia generation. The paper goes on to show networks in cortical layers 2/3 and 5a have the connectivity required for the behavior proposed, and reviews some evidence for a link between such local cortical cyclic activity and conscious percepts. It concludes with some predictions based on the theory discussed. PMID:23504586

  12. Water-related absorption in fibrous diamonds

    NASA Astrophysics Data System (ADS)

    Zedgenizov, D. A.; Shiryaev, A. A.; Kagi, H.; Navon, O.

    2003-04-01

    Cubic and coated diamonds from several localities (Brasil, Canada, Yakutia) were investigated using spectroscopic techniques. Special emphasis was put on investigation of water-related features of transmission Infra-red and Raman spectra. Presence of molecular water is inferred from broad absorption bands in IR at 3420 and 1640 cm-1. These bands were observed in many of the investigated samples. It is likely that molecular water is present in microinclusions in liquid state, since no clear indications of solid H_2O (ice VI-VII, Kagi et al., 2000) were found. Comparison of absorption by HOH and OH vibrations shows that diamonds can be separated into two principal groups: those containing liquid water (direct proportionality of OH and HOH absorption) and those with stronger absorption by OH group. Fraction of diamonds in every group depends on their provenance. There might be positive correlation between internal pressure in microinclusions (determined using quartz barometer, Navon et al., 1988) and affiliation with diamonds containing liquid water. In many cases absorption by HOH vibration is considerably lower than absorption by hydroxyl (OH) group. This may be explained if OH groups are partially present in mineral and/or melt inclusions. This hypothesis is supported by following fact: in diamonds with strong absorption by silicates and other minerals shape and position of the OH band differs from that in diamonds with low absorption by minerals. Moreover, in Raman spectra of individual inclusions sometimes the broad band at 3100 cm-1 is observed. This band is OH-related. In some samples water distribution is not homogeneous. Central part of the diamond usually contains more water than outer parts, but this is not a general rule for all the samples. Water absorption usually correlated with absorption of other components (carbonates, silicates and others). At that fibrous diamonds with relatively high content of silicates are characterized by molecular water. OH

  13. Papillary Thyroid Carcinoma Arising in Children and Adolescent Hashimoto's Thyroiditis: Ultrasonographic and Pathologic Findings.

    PubMed

    Jeong, Sun Hye; Hong, Hyun Sook; Lee, Eun Hye; Kwak, Jeong Ja

    2016-01-01

    Objectives. We compared the ultrasonography and pathology features of papillary thyroid carcinoma (PTC) in pediatric and adolescents with Hashimoto's thyroiditis (HT) with those of non-HT patients. Materials and Methods. Eleven patients who were surgically confirmed to have pediatric or adolescent PTC from 2006 to 2014 were included in this study. We retrospectively analyzed the preoperative ultrasonography and pathology features of PTC arising in HT and non-HT patients. Results. On ultrasonography, thyroid gland was lobulated and enlarged, with many scattered microcalcifications in four of five HT patients. Four of six non-HT patients had suspicious masses with calcifications. The diffuse sclerosing variant of PTC (DSVPTC) was found in three of five HT patients, but none in non-HT patients. Macroscopic or microscopic extrathyroidal extension was evident in all of the HT patients and four of the non-HT patients. Neck lymph node metastases were in all HT patients and five of non-HT patients. Conclusions. Three of five PTCs in pediatric and adolescent HT patients were DSVPTC, whereas all PTCs of the non-HT patients were classic type. On ultrasonography, thyroid gland was diffusely enlarged with scattered microcalcifications in four of five HT patients. All five HT cases had aggressive disease, including extrathyroidal extension and cervical lymph node metastases. PMID:26977145

  14. Multiple benefits arising from novel management of agricultural ditches

    NASA Astrophysics Data System (ADS)

    Jonczyk, Jennine; Barber, Nick; Quinn, Paul

    2016-04-01

    The opportunity to modify the function and dynamics of farm ditches is very high. There are many kilometres of ditch that could offer multiple benefits to pollution control and lowering flood risk. However, there is first a perception problem to overcome, in that most farmers wish to remove water from the land quickly and are irritated by the accumulation of sediment. Hence, we have built a series of demonstration ditches where the new operation of the ditch can be shown to trap substantial amounts of sediment and nutrients and also not cause any local flooding or water logging problems. The ditch itself is radically changed in shape and is widened as much as possible and usually has a flat bottom. The ditch will also contain a series of leaky barriers that will retain flow during storm events. In very large events an overflow structure is required. These features do have to be engineered to a good level of safety to avoid failure. Sediment must also be recovered from the ditch frequently (at least annually) which again could be a role fulfilled by the farmer. We will show a number of example ditch designs and the data captured in experiments. One feature typically captures 50% of the suspended sediment, 30% of total phosphorus and 20% of the nitrate in a single storm.

  15. Io's Thermal Regions and Non-SO2 Spectral Features

    NASA Technical Reports Server (NTRS)

    Smythe, W. D.; Soderblom, L. A.; Lopes, R. M. C.

    2003-01-01

    Several absorptions have been identified in the Galileo NIMS spectra of Io that are not related to SO2. [1,2]. These absorptions have band centers at 2.97, 3.15, 3.85, and 3.91 microns. There are also broad absorptions in the regions 1-1.3 and 3- 3.4 microns. Patterning noise in wavelength registration, arising from the pushbroom imaging and grating motion of the NIMS instrument have previously inhibited reliable mapping of weak absorptions. Recent improvements in techniques to remove the coherent pattern noise from the NIMS dataset have been made by Soderblom. This greatly improves the signal to noise ratio and enables mapping of weak spectral signatures such as the 3.15 micron absorption on Io.

  16. 69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    69. INTERIOR VIEW OF THE ABSORPTION TOWER BUILDING, ABSORPTION TOWER UNDER CONSTRUCTION. (DATE UNKNOWN). - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

  17. Exciton-Like Behavior in Low-Energy Absorption Spectra of Simple Alloys

    NASA Astrophysics Data System (ADS)

    Bakshi, Mira Hemendraray

    The valence excitation (ns('2) (--->) nsnp) spectra of Mg, Zn, and Ca impurities at various concentrations in Li have been measured. Polarization modulation ellipsometry was used to determine the impurity-induced changes in real and imaginary parts of the dielectric function simultaneously, together with the differential reflectivity, in the energy range 1.5 - 4.5 eV. The most important result at sufficiently dilute alloy compositions, is that the system investigated display a distinct absorption peak above the Drude background. The height of this peak varies linearly with impurity content. The impurity-specific character of these spectral features points to exciton-like behavior at low-energy, arising from atomic-like excitations in which the electron and the hole linger together at the impurity site. Existing theories of alloy spectra do not explain these effects, because they do not include the Coulomb correlations between the interacting quasiparticles created in the optical event, or the way in which the interacting pair is confined to the impurity site by the mutual field. A remarkable added result of this research is that the exciton-like behavior can be followed with increasing impurity content, all the way to the pure Mg response, when it becomes the interband transition. This has led Kunz and Flynn to reformulate the theory of optical absorption including excited state interactions; and to apply the theory to the spectrum of pure Mg. The Coulomb interaction causes striking effects which are in generally good agreement with experiment. Zn-Li alloys behave differently. At an alloy composition for which Zn-Zn interactions become prevalent, the local, impurity-specific character of the spectrum disappears, leaving only a featureless Drude-like absorption. These results have provoked cluster calculations by Boisvert and Kunz, which predict the spectral shifts, and exhibit qualitatively similar persistence for Mg-Li, and broadening for Zn-Li.

  18. Biomechanics (Communication arising): prey attack by a large theropod dinosaur.

    PubMed

    Frazzetta, T H; Kardong, Kenneth V

    2002-03-28

    Prey-capture strategies in carnivorous dinosaurs have been inferred from the biomechanical features of their tooth structure, the estimated bite force produced, and their diet. Rayfield et al. have used finite-element analysis (FEA) to investigate such structure-function relationships in Allosaurus fragilis, and have found that the skull was designed to bear more stress than could be generated by simple biting. They conclude that this large theropod dinosaur delivered a chop-and-slash 'hatchet' blow to its prey, which it approached with its mouth wide open before driving its upper tooth row downwards. We argue that this mode of predation is unlikely, and that the FEA results, which relate to an 'overengineered' skull, are better explained by the biomechanical demands of prey capture. Understanding the mechanics of predation is important to our knowledge of the feeding habits of carnivorous dinosaurs and for accurate reconstruction their lifestyles.

  19. Vaginal Absorption of Penicillin.

    PubMed

    Rock, J; Barker, R H; Bacon, W B

    1947-01-01

    Except during the last two months of pregnancy, penicillin is easily absorbed from cocoa butter suppositories in the vagina, ordinarily to give therapeutic blood levels for from 4 to 6 hours. Penicillin in the dosage used seems to have a good effect on vaginal infections. In nonpregnant women, during the ovulation phase, considered as including days 14 +/- 2 in the ordinary menstrual cycle of about 28 days, absorption seemed to be somewhat diminished. Higher levels were found in patients who were near the end of their menstrual cycles and in two patients who were menopausal. Patients who were very near term absorbed little or no penicillin, whereas patients 10 days post partum showed excellent absorption.

  20. Photothermal absorption correlation spectroscopy.

    PubMed

    Octeau, Vivien; Cognet, Laurent; Duchesne, Laurence; Lasne, David; Schaeffer, Nicolas; Fernig, David G; Lounis, Brahim

    2009-02-24

    Fluorescence correlation spectroscopy (FCS) is a popular technique, complementary to cell imaging for the investigation of dynamic processes in living cells. Based on fluorescence, this single molecule method suffers from artifacts originating from the poor fluorophore photophysics: photobleaching, blinking, and saturation. To circumvent these limitations we present here a new correlation method called photothermal absorption correlation spectroscopy (PhACS) which relies on the absorption properties of tiny nano-objects. PhACS is based on the photothermal heterodyne detection technique and measures akin FCS, the time correlation function of the detected signals. Application of this technique to the precise determination of the hydrodynamic sizes of different functionalized gold nanoparticles are presented, highlighting the potential of this method. PMID:19236070

  1. THE ABSORPTION OF ADRENALIN

    PubMed Central

    Lyon, D. Murray

    1923-01-01

    1. Adrenalin solution given subcutaneously is usually rapidly absorbed, probably by lymphatic channels. 2. The speed of this process may be influenced by the circulation rate. 3. The relative amounts of adrenalin at any moment unabsorbed at the site of inoculation, carried in the circulating fluids, and taken up by the reacting tissues can be calculated from figures extracted from the curve of the blood pressure changes. The relative rates of transference of adrenalin into the blood and from the circulation into the tissues can also be estimated. 4. When absorption takes place rapidly a large quantity of the drug comes into action at once and the maximum occurs early, the curve of blood pressure reaches a considerable height, and subsides quickly. When absorption is slow the apex appears later and does not reach so high a level. 5. The response to adrenalin bears a logarithmic relationship to the dose employed and a method of allowing for this is indicated. PMID:19868816

  2. UV laser long-path absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    Dorn, Hans-Peter; Brauers, Theo; Neuroth, Rudolf

    1994-01-01

    Long path Differential Optical Absorption Spectroscopy (DOAS) using a picosecond UV laser as a light source was developed in our institute. Tropospheric OH radicals are measured by their rotational absorption lines around 308 nm. The spectra are obtained using a high resolution spectrograph. The detection system has been improved over the formerly used optomechanical scanning device by application of a photodiode array which increased the observed spectral range by a factor of 6 and which utilizes the light much more effectively leading to a considerable reduction of the measurement time. This technique provides direct measurements of OH because the signal is given by the product of the absorption coefficient and the OH concentration along the light path according to Lambert-Beers law. No calibration is needed. Since the integrated absorption coefficient is well known the accuracy of the measurement essentially depends on the extent to which the OH absorption pattern can be detected in the spectra. No interference by self generated OH radicals in the detection lightpath has been observed. The large bandwidth (greater than 0.15 nm) and the high spectral resolution (1.5 pm) allows absolute determination of interferences by other trace gas absorptions. The measurement error is directly accessible from the absorption-signal to baseline-noise ratio in the spectra. The applicability of the method strongly depends on visibility. Elevated concentrations of aerosols lead to considerable attenuation of the laser light which reduces the S/N-ratio. In the moderately polluted air of Julich, where we performed a number of OH measurement spectra. In addition absorption features of unidentified species were frequently detected. A quantitative deconvolution even of the known species is not easy to achieve and can leave residual structures in the spectra. Thus interferences usually increase the noise and deteriorate the OH detection sensitivity. Using diode arrays for sensitive

  3. Relic Neutrino Absorption Spectroscopy

    SciTech Connect

    Eberle, b

    2004-01-28

    Resonant annihilation of extremely high-energy cosmic neutrinos on big-bang relic anti-neutrinos (and vice versa) into Z-bosons leads to sizable absorption dips in the neutrino flux to be observed at Earth. The high-energy edges of these dips are fixed, via the resonance energies, by the neutrino masses alone. Their depths are determined by the cosmic neutrino background density, by the cosmological parameters determining the expansion rate of the universe, and by the large redshift history of the cosmic neutrino sources. We investigate the possibility of determining the existence of the cosmic neutrino background within the next decade from a measurement of these absorption dips in the neutrino flux. As a by-product, we study the prospects to infer the absolute neutrino mass scale. We find that, with the presently planned neutrino detectors (ANITA, Auger, EUSO, OWL, RICE, and SalSA) operating in the relevant energy regime above 10{sup 21} eV, relic neutrino absorption spectroscopy becomes a realistic possibility. It requires, however, the existence of extremely powerful neutrino sources, which should be opaque to nucleons and high-energy photons to evade present constraints. Furthermore, the neutrino mass spectrum must be quasi-degenerate to optimize the dip, which implies m{sub {nu}} 0.1 eV for the lightest neutrino. With a second generation of neutrino detectors, these demanding requirements can be relaxed considerably.

  4. CO2 Capture from Flue Gas by Phase Transitional Absorption

    SciTech Connect

    Liang Hu

    2009-06-30

    A novel absorption process called Phase Transitional Absorption was invented. What is the Phase Transitional Absorption? Phase Transitional Absorption is a two or multi phase absorption system, CO{sub 2} rich phase and CO{sub 2} lean phase. During Absorption, CO{sub 2} is accumulated in CO{sub 2} rich phase. After separating the two phases, CO{sub 2} rich phase is forward to regeneration. After regeneration, the regenerated CO{sub 2} rich phase combines CO{sub 2} lean phase to form absorbent again to complete the cycle. The advantage for Phase Transitional Absorption is obvious, significantly saving on regeneration energy. Because CO{sub 2} lean phase was separated before regeneration, only CO{sub 2} rich phase was forward to regeneration. The absorption system we developed has the features of high absorption rate, high loading and working capacity, low corrosion, low regeneration heat, no toxic to environment, etc. The process evaluation shows that our process is able to save 80% energy cost by comparing with MEA process.

  5. Enhanced absorption cycle computer model. Final report

    SciTech Connect

    Grossman, G.; Wilk, M.

    1993-09-01

    Absorption heat pumps have received renewed and increasing attention in the past two decades. The rising cost of electricity has made the particular features of this heat-powered cycle attractive for both residential and industrial applications. Solar-powered absorption chillers, gas-fired domestic heat pumps, and waste-heat-powered industrial temperatures boosters are a few of the applications recently subjected to intensive research and development. The absorption heat pump research community has begun to search for both advanced cycles in various multistage configurations and new working fluid combinations with potential for enhanced performance and reliability. The development of working absorptions systems has created a need for reliable and effective system simulations. A computer code has been developed for simulation of absorption systems at steady state in a flexible and modular form, making it possible to investigate various cycle configurations with different working fluids. The code is based on unit subroutines containing the governing equations for the system`s components and property subroutines containing thermodynamic properties of the working fluids. The user conveys to the computer an image of his cycle by specifying the different subunits and their interconnections. Based on this information, the program calculates the temperature, flow rate, concentration, pressure, and vapor fraction at each state point in the system, and the heat duty at each unit, from which the coefficient of performance (COP) may be determined. This report describes the code and its operation, including improvements introduced into the present version. Simulation results are described for LiBr-H{sub 2}O triple-effect cycles, LiCl-H{sub 2}O solar-powered open absorption cycles, and NH{sub 3}-H{sub 2}O single-effect and generator-absorber heat exchange cycles. An appendix contains the User`s Manual.

  6. THE tilde{A}-tilde{X} AND tilde{B}-tilde{X} ABSORPTIONS OF NO_3 TRAPPED IN SOLID NEON

    NASA Astrophysics Data System (ADS)

    Jacox, Marilyn E.; Thompson, Warren E.

    2009-06-01

    Absorptions arising from the tilde{A}-tilde{X} transition of normal and isotopically substituted NO_3 have been observed between 7500 and 9500 cm^{-1}. Details of the spectra will be discussed and assignments will be proposed. Absorptions arising from the tilde{B}-tilde{X} transition of NO_3, with band origin near 15 000 cm^{-1}, have also been observed for the normal species and two of its isotopologues which possess D_{3h} symmetry. As in the gas phase, the absorptions are broadened because of predissociation. The observed band structure corresponds closely with that reported for the gas-phase molecule.

  7. Corrosion Problems in Absorption Chillers

    ERIC Educational Resources Information Center

    Stetson, Bruce

    1978-01-01

    Absorption chillers use a lithium bromide solution as the medium of absorption and water as the refrigerant. Discussed are corrosion and related problems, tests and remedies, and cleaning procedures. (Author/MLF)

  8. Protein local conformations arise from a mixture of Gaussian distributions.

    PubMed

    Tendulkar, Ashish V; Ogunnaike, Babatunde; Wangikar, Pramod P

    2007-08-01

    The classical approaches for protein structure prediction rely either on homology of the protein sequence with a template structure or on ab initio calculations for energy minimization. These methods suffer from disadvantages such as the lack of availability of homologous template structures or intractably large conformational search space, respectively. The recently proposed fragment library based approaches first predict the local structures,which can be used in conjunction with the classical approaches of protein structure prediction. The accuracy of the predictions is dependent on the quality of the fragment library. In this work, we have constructed a library of local conformation classes purely based on geometric similarity. The local conformations are represented using Geometric Invariants, properties that remain unchanged under transformations such as translation and rotation, followed by dimension reduction via principal component analysis. The local conformations are then modeled as a mixture of Gaussian probability distribution functions (PDF). Each one of the Gaussian PDF's corresponds to a conformational class with the centroid representing the average structure of that class. We find 46 classes when we use an octapeptide as a unit of local conformation. The protein 3-D structure can now be described as a sequence of local conformational classes. Further, it was of interest to see whether the local conformations can be predicted from the amino acid sequences. To that end,we have analyzed the correlation between sequence features and the conformational classes. PMID:17914232

  9. Spitz nevus arising in the eyelid of a teenager.

    PubMed

    Shields, Patrick W; Jakobiec, Frederick A; Stagner, Anna M; Yoon, Michael K

    2016-01-01

    A 16-year-old boy developed over a 2-month interval a lightly pigmented left upper eyelid lesion measuring 1.5 mm in greatest diameter that, when excised, microscopically was hypercellular and composed almost exclusively of nonpigmented epithelioid cells that created florid, large intraepidermal junctional nests and sheets and nests of subepidermal cells. The diagnosis was a Spitz nevus. HMB-45, MART-1, and microphthalmia-associated transcription factor were all positive and established the melanocytic nature of the benign tumor. The Ki-67 proliferation index (5%) and 2 mitoses/mm(2) were both low; p16 protein was immunohistochemically identified in the nevoid cells. We review the clinical, histopathologic, and other immunohistochemical features of this entity and provide a brief differential diagnosis (including separation from a Spitzoid melanoma). This is only the third eyelid Spitz nevus reported in the literature and is the most fully characterized immunohistochemically. At their present stage of development, contemporary immunohistochemical biomarkers, while providing supplemental information, nonetheless remain less than definitive in terms of reliably distinguishing benign from malignant Spitz lesions.

  10. The emission/absorption FE 2 spectrum of HD 45677

    NASA Technical Reports Server (NTRS)

    Stalio, R.; Selvelli, P. L.

    1981-01-01

    The complex behavior of the emission/absorption spectrum of Fe II is analyzed. The far UV spectrum is characterized almost solely by absorption lines, while, in the near UV, strong emissions are predominant. Radiative excitation from the ground to the highest levels (chi is approximately 10 eV) with re-emission in the near UV, visible and I.R. seems to be the main mechanism capable of explaining the observed spectral features.

  11. Selenoproteins-What unique properties can arise with selenocysteine in place of cysteine?

    SciTech Connect

    Arner, Elias S.J.

    2010-05-01

    The defining entity of a selenoprotein is the inclusion of at least one selenocysteine (Sec) residue in its sequence. Sec, the 21st naturally occurring genetically encoded amino acid, differs from its significantly more common structural analog cysteine (Cys) by the identity of a single atom: Sec contains selenium instead of the sulfur found in Cys. Selenium clearly has unique chemical properties that differ from sulfur, but more striking are perhaps the similarities between the two elements. Selenium was discovered by Joens Jacob Berzelius, a renowned Swedish scientist instrumental in establishing the institution that would become Karolinska Institutet. Written at the occasion of the bicentennial anniversary of Karolinska Institutet, this mini review focuses on the unique selenium-derived properties that may potentially arise in a protein upon the inclusion of Sec in place of Cys. With 25 human genes encoding selenoproteins and in total several thousand selenoproteins yet described in nature, it seems likely that the presence of that single selenium atom of Sec should convey some specific feature, thereby explaining the existence of selenoproteins in spite of demanding and energetically costly Sec-specific synthesis machineries. Nonetheless, most, if not all, of the currently known selenoproteins are also found as Cys-containing non-selenoprotein orthologues in other organisms, wherefore any potentially unique properties of selenoproteins are yet a matter of debate. The pK{sub a} of free Sec (approximately 5.2) being significantly lower than that of free Cys (approximately 8.5) has often been proposed as one of the unique features of Sec. However, as discussed herein, this pK{sub a} difference between Sec and Cys can hardly provide an evolutionary pressure for maintenance of selenoproteins. Moreover, the typically 10- to 100-fold lower enzymatic efficiencies of Sec-to-Cys mutants of selenoprotein oxidoreductases, are also weak arguments for the overall existence

  12. Exciton absorption of entangled photons in semiconductor quantum wells

    NASA Astrophysics Data System (ADS)

    Rodriguez, Ferney; Guzman, David; Salazar, Luis; Quiroga, Luis; Condensed Matter Physics Group Team

    2013-03-01

    The dependence of the excitonic two-photon absorption on the quantum correlations (entanglement) of exciting biphotons by a semiconductor quantum well is studied. We show that entangled photon absorption can display very unusual features depending on space-time-polarization biphoton parameters and absorber density of states for both bound exciton states as well as for unbound electron-hole pairs. We report on the connection between biphoton entanglement, as quantified by the Schmidt number, and absorption by a semiconductor quantum well. Comparison between frequency-anti-correlated, unentangled and frequency-correlated biphoton absorption is addressed. We found that exciton oscillator strengths are highly increased when photons arrive almost simultaneously in an entangled state. Two-photon-absorption becomes a highly sensitive probe of photon quantum correlations when narrow semiconductor quantum wells are used as two-photon absorbers. Research funds from Facultad de Ciencias, Universidad de los Andes

  13. Acoustic Absorption Characteristics of People.

    ERIC Educational Resources Information Center

    Kingsbury, H. F.; Wallace, W. J.

    1968-01-01

    The acoustic absorption characteristics of informally dressed college students in typical classroom seating are shown to differ substantially from data for formally dressed audiences in upholstered seating. Absorption data, expressed as sabins per person or absorption coefficient per square foot, shows that there is considerable variation between…

  14. One to Watch: A Germ Cell Tumor Arising in an Undescended Testicle in Rubinstein-Taybi Syndrome.

    PubMed

    Butler, Grainne H; Boyle, Michael; Lynch, Sally Ann; Ryan, Stephanie; McDermott, Michael; Capra, Michael

    2016-08-01

    A male preterm infant was born with dysmorphic features consistent with Rubinstein-Taybi syndrome (RTS). An undescended right testicle was noted on examination. At 5 months of age he developed a palpable right-sided abdominal mass and an elevated alpha-fetoprotein. Histology revealed a malignant germ cell neoplasm arising within the undescended testis. This is the first reported case of a germ cell tumor occurring in a pediatric patient with RTS. Urologic abnormalities occur in approximately 52% of RTS patients, of which cryptorchidism is the commonest. Given the frequency of undescended testes in this population, closer screening may be warranted.

  15. Malignant mixed tumour arising from minor salivary gland tissue of the right parapharyngeal space with metastasis to the scalp.

    PubMed

    Tan, P H; Chew, C T; Cheah, E S

    1992-05-01

    A case of malignant mixed tumour arising from minor salivary gland tissue in the right parapharyngeal space with metastasis to the scalp is described. Both the clinical presentation and the histological picture were unusual. The simultaneous discovery of the primary parapharyngeal tumour and its scalp metastasis, the relatively young age of the patient (43 years-old), the origin of the tumour in minor salivary gland tissue, and the presence of a benign stromal component in the metastasis are features not commonly described in the three entities covered by the term "malignant mixed tumour". We believe this case represents a distinct variant, whose behaviour and progression have not been previously well documented.

  16. Acetaminophen (paracetamol) oral absorption and clinical influences.

    PubMed

    Raffa, Robert B; Pergolizzi, Joseph V; Taylor, Robert; Decker, John F; Patrick, Jeffrey T

    2014-09-01

    Acetaminophen (paracetamol) is a widely used nonopioid, non-NSAID analgesic that is effective against a variety of pain types, but the consequences of overdose can be severe. Because acetaminophen is so widely available as a single agent and is increasingly being formulated in fixed-ratio combination analgesic products for the potential additive or synergistic analgesic effect and/or reduced adverse effects, accidental cumulative overdose is an emergent concern. This has rekindled interest in the sites, processes, and pharmacokinetics of acetaminophen oral absorption and the clinical factors that can influence these. The absorption of oral acetaminophen occurs primarily along the small intestine by passive diffusion. Therefore, the rate-limiting step is the rate of gastric emptying into the intestines. Several clinical factors can affect absorption per se or the rate of gastric emptying, such as diet, concomitant medication, surgery, pregnancy, and others. Although acetaminophen does not have the abuse potential of opioids or the gastrointestinal bleeding or organ adverse effects of NSAIDs, excess amounts can produce serious hepatic injury. Thus, an understanding of the sites and features of acetaminophen absorption--and how they might be influenced by factors encountered in clinical practice--is important for pain management using this agent. It can also provide insight for design of formulations that would be less susceptible to clinical variables.

  17. Acetaminophen (paracetamol) oral absorption and clinical influences.

    PubMed

    Raffa, Robert B; Pergolizzi, Joseph V; Taylor, Robert; Decker, John F; Patrick, Jeffrey T

    2014-09-01

    Acetaminophen (paracetamol) is a widely used nonopioid, non-NSAID analgesic that is effective against a variety of pain types, but the consequences of overdose can be severe. Because acetaminophen is so widely available as a single agent and is increasingly being formulated in fixed-ratio combination analgesic products for the potential additive or synergistic analgesic effect and/or reduced adverse effects, accidental cumulative overdose is an emergent concern. This has rekindled interest in the sites, processes, and pharmacokinetics of acetaminophen oral absorption and the clinical factors that can influence these. The absorption of oral acetaminophen occurs primarily along the small intestine by passive diffusion. Therefore, the rate-limiting step is the rate of gastric emptying into the intestines. Several clinical factors can affect absorption per se or the rate of gastric emptying, such as diet, concomitant medication, surgery, pregnancy, and others. Although acetaminophen does not have the abuse potential of opioids or the gastrointestinal bleeding or organ adverse effects of NSAIDs, excess amounts can produce serious hepatic injury. Thus, an understanding of the sites and features of acetaminophen absorption--and how they might be influenced by factors encountered in clinical practice--is important for pain management using this agent. It can also provide insight for design of formulations that would be less susceptible to clinical variables. PMID:26013309

  18. Christiansen effect in disperse systems with resonant absorption

    SciTech Connect

    Zimnyakov, D A; Isaeva, Elmira A; Isaeva, A A

    2012-01-31

    We discuss the results of experimental studies of competition of absorption and scattering of laser radiation propagating in dispersive media with resonant absorption. As media under study, use is made of a suspension of polystyrene particles in solutions of rhodamine 6G in ethylene glycol probed by laser light with a wavelength of 532 nm. It is found that an increase in the dye concentration leads to an increase in optical transmittance of suspensions and an increase in speckle modulation of the forward-scattered radiation. We interpret these features as a manifestation of Christiansen effect in disperse systems with resonance absorption.

  19. Vanishing absorption and blueshifted emission in FeLoBAL quasars

    NASA Astrophysics Data System (ADS)

    Rafiee, Alireza; Pirkola, Patrik; Hall, Patrick B.; Galati, Natalee; Rogerson, Jesse; Ameri, Abtin

    2016-07-01

    We study the dramatic decrease in iron absorption strength in the iron low-ionization broad absorption line quasar SDSS J084133.15+200525.8. We report on the continued weakening of absorption in the prototype of this class of variable broad absorption line quasar, FBQS J140806.2+305448. We also report a third example of this class, SDSS J123103.70+392903.6; unlike the other two examples, it has undergone an increase in observed continuum brightness (at 3000 Å rest frame) as well as a decrease in iron absorption strength. These changes could be caused by absorber transverse motion or by ionization variability. We note that the Mg II and UV Fe II lines in several FeLoBAL quasars are blueshifted by thousands of km s-1 relative to the H β emission line peak. We suggest that such emission arises in the outflowing winds normally seen only in absorption.

  20. Absorption heat pumps

    NASA Astrophysics Data System (ADS)

    Huhtinen, M.; Heikkilae, M.; Andersson, R.

    1987-03-01

    The aim of the study was to analyze the technical and economic feasibility of absorption heat pumps in Finland. The work was done as a case study: the technical and economic analyses have been carried out for six different cases, where in each the suitable size and type of the heat pump plant and the auxiliary components and connections were specified. The study also detailed the costs concerning the procurement, installation and test runs of the machinery, as well as the savings in energy costs incurred by the introduction of the plant. Conclusions were drawn of the economic viability of the applications studied. The following cases were analyzed: heat recovery from flue gases and productin of district heat in plants using peat, natural gas, and municipal wastes as a fuel. Heat recovery in the pulp and paper industry for the upgrading of pressure of secondary steam and for the heating of white liquor and combustion and drying the air. Heat recovery in a peat-fulled heat and power plant from flue gases that have been used for the drying of peat. According to the study, the absorption heat pump suits best to the production of district heat, when the heat source is the primary energy is steam produced by the boiler. Included in the flue as condensing is the purification of flue gases. Accordingly, benefit is gained on two levels in thick applications. In heat and power plants the use of absorption heat pumps is less economical, due to the fact that the steam used by the pump reduces the production of electricity, which is rated clearly higher than heat.

  1. Ultraviolet absorption hygrometer

    DOEpatents

    Gersh, Michael E.; Bien, Fritz; Bernstein, Lawrence S.

    1986-01-01

    An ultraviolet absorption hygrometer is provided including a source of pulsed ultraviolet radiation for providing radiation in a first wavelength region where water absorbs significantly and in a second proximate wavelength region where water absorbs weakly. Ultraviolet radiation in the first and second regions which has been transmitted through a sample path of atmosphere is detected. The intensity of the radiation transmitted in each of the first and second regions is compared and from this comparison the amount of water in the sample path is determined.

  2. Ultraviolet absorption hygrometer

    DOEpatents

    Gersh, M.E.; Bien, F.; Bernstein, L.S.

    1986-12-09

    An ultraviolet absorption hygrometer is provided including a source of pulsed ultraviolet radiation for providing radiation in a first wavelength region where water absorbs significantly and in a second proximate wavelength region where water absorbs weakly. Ultraviolet radiation in the first and second regions which has been transmitted through a sample path of atmosphere is detected. The intensity of the radiation transmitted in each of the first and second regions is compared and from this comparison the amount of water in the sample path is determined. 5 figs.

  3. Modular total absorption spectrometer

    NASA Astrophysics Data System (ADS)

    Karny, M.; Rykaczewski, K. P.; Fijałkowska, A.; Rasco, B. C.; Wolińska-Cichocka, M.; Grzywacz, R. K.; Goetz, K. C.; Miller, D.; Zganjar, E. F.

    2016-11-01

    The design and performance of the Modular Total Absorption Spectrometer built and commissioned at the Oak Ridge National Laboratory is presented. The active volume of the detector is approximately one ton of NaI(Tl), which results in very high full γ energy peak efficiency of 71% at 6 MeV and nearly flat efficiency of around 81.5% for low energy γ-rays between 300 keV and 1 MeV. In addition to the high peak efficiency, the modular construction of the detector permits the use of a γ-coincidence technique in data analysis as well as β-delayed neutron observation.

  4. Light absorption properties and absorption budget of Southeast Pacific waters

    NASA Astrophysics Data System (ADS)

    Bricaud, Annick; Babin, Marcel; Claustre, Hervé; Ras, JoséPhine; TièChe, Fanny

    2010-08-01

    Absorption coefficients of phytoplankton, nonalgal particles (NAPs), and colored dissolved organic matter (CDOM), and their relative contributions to total light absorption, are essential variables for bio-optical and biogeochemical models. However, their actual variations in the open ocean remain poorly documented, particularly for clear waters because of the difficulty in measuring very low absorption coefficients. The Biogeochemistry and Optics South Pacific Experiment (BIOSOPE) cruise investigated a large range of oceanic regimes, from mesotrophic waters around the Marquesas Islands to hyperoligotrophic waters in the subtropical gyre and eutrophic waters in the upwelling area off Chile. The spectral absorption coefficients of phytoplankton and NAPs were determined using the filter technique, while the CDOM absorption coefficients were measured using a 2 m capillary waveguide. Over the whole transect, the absorption coefficients of both dissolved and particulate components covered approximately two orders of magnitude; in the gyre, they were among the lowest ever reported for open ocean waters. In the oligotrophic and mesotrophic waters, absorption coefficients of phytoplankton and NAPs were notably lower than those measured in other oceanic areas with similar chlorophyll contents, indicating some deviation from the standard chlorophyll-absorption relationships. The contribution of absorption by NAPs to total particulate absorption showed large vertical and horizontal variations. CDOM absorption coefficients covaried with algal biomass, albeit with a high scatter. The spectral slopes of both NAP and CDOM absorption revealed structured spatial variability in relation with the trophic conditions. The relative contributions of each component to total nonwater absorption were (at a given wavelength) weakly variable over the transect, at least within the euphotic layer.

  5. Overview-absorption/Rankine solar cooling program

    NASA Astrophysics Data System (ADS)

    Wahlig, M.; Heitz, A.; Boyce, B.

    1980-03-01

    The tasks being performed in the absorption and Rankine program areas run the gamut from basic work on fluids to development of chillers and chiller components, to field and reliability testing of complete cooling systems. In the absorption program, there are six current and five essentially completed projects. In the Rankine program, there are five current projects directly supported by DOE, and three projects funded through and managed by NASA/MSFC (Manned Space Flight Center, Huntsville, Alabama). The basic features of these projects are discussed. The systems under development in five of these current projects were selected for field testing in the SOLERAS program, a joint US-Saudi Arabian enterprise. Some technical highlights of the program are presented.

  6. Spectrophotometry of six broad absorption line QSOs

    NASA Technical Reports Server (NTRS)

    Junkkarinen, Vesa T.; Burbidge, E. Margaret; Smith, Harding E.

    1987-01-01

    Spectrophotometric observations of six broad absorption-line QSOs (BALQSOs) are presented. The continua and emission lines are compared with those in the spectra of QSOs without BALs. A statistically significant difference is found in the emission-line intensity ratio for (N V 1240-A)/(C IV 1549-A). The median value of (N V)/(C IV) for the BALQSOs is two to three times the median for QSOs without BALs. The absorption features of the BALQSOs are described, and the column densities and limits on the ionization structure of the BAL region are discussed. If the dominant ionization mechanism is photoionization, then it is likely that either the ionizing spectrum is steep or the abundances are considerably different from solar. Collisional ionization may be a significant factor, but it cannot totally dominate the ionization rate.

  7. Myoepithelial carcinoma arising in a benign myoepithelioma: immunohistochemical, ultrastructural, and flow-cytometrical study.

    PubMed

    Bombí, J A; Alós, L; Rey, M J; Mallofré, C; Cuchi, A; Trasserra, J; Cardesa, A

    1996-01-01

    A case of myoepithelial carcinoma arising in a benign myoepithelioma of the minor salivary gland in a 71-year-old patient is reported. The tumor presented initially on the palate and had been diagnosed as "benign lesion" 40 years before. It recurred 22, 36, and 40 years after initial presentation, and a similar histopathological diagnosis was rendered. One year after the last recurrence, the tumor recurred showing typical changes of malignant transformation, and the diagnosis was malignant myoepithelioma. The light microscopy and ultrastructural features of the initial tumor were typical of plasmocytoid myoepithelioma. There were abundant round cells and rare spindle cells with uniform dispersed filaments, sometimes arranged in parallel streams without evidence of dense bodies. These cells showed micropinocytotic vesicles along the cell membrane with poorly developed intercellular junctions and were surrounded by a basal membrane. The malignant counterpart showed fewer plasmocytoid cells and a rather epithelial pattern with marked nuclear pleomorphism and formation of small, or rarely large, glandular lumina. The immunohistochemical features were similar for the benign and malignant tumors, with positivity for S-100 protein, vimentin, cytokeratins, and CAM 5.2, and were negative for GFAP, muscle-specific actin, CEA, and desmin. Flow cytometry showed a change in the DNA content profile. The benign myoepithelioma had a diploid DNA content with a low S-phase fraction of 3.9% and proliferative index of 9.1%, while the myoepithelial carcinoma had an evident aneuploid DNA stem line and an increased S-phase fraction of 8.3% with a proliferative index of 18.1%.

  8. Congenital Giant Teratoma Arising from the Hard Palate: A Rare Clinical Presentation

    PubMed Central

    Veligandla, Indira; Lakshmi, A.R.Vijaya; Pandey, Vanita

    2016-01-01

    Teratomas are rare tumours which originate from all 3 germs cell layers namely endoderm, mesoderm and ectoderm, with varying proportions of each component. The most common site of teratoma is in the sacro-coccygeal region. Teratomas are generally benign and have well appreciable clinical and histopathological features. Incidence of congenital teratoma is 1 in 4000. In head and neck region congenital teratomas usually associated with other anomalies like cystic hygroma and cleft palate with an incidence of 1 in 400. The approximately reported incidence of palatal teratoma is 1 in 35000 to 40000 live-births. Upper airway difficulty causes anticipated functional problems at hypopharynx. The prognosis of palatal teratoma mostly depends on the risk and extent of neonatal respiratory distress. We present a rare case of congenital teratoma arising from the hard palate in a new born girl. The outcome in this case was bad due to the large mass causing respiratory difficulty and bleeding from the ruptured cystic areas leading to hypovolemic shock. After two hours of delivery, baby expired. PMID:27630855

  9. Congenital Giant Teratoma Arising from the Hard Palate: A Rare Clinical Presentation.

    PubMed

    Kumar, Kandukuri Mahesh; Veligandla, Indira; Lakshmi, A R Vijaya; Pandey, Vanita

    2016-07-01

    Teratomas are rare tumours which originate from all 3 germs cell layers namely endoderm, mesoderm and ectoderm, with varying proportions of each component. The most common site of teratoma is in the sacro-coccygeal region. Teratomas are generally benign and have well appreciable clinical and histopathological features. Incidence of congenital teratoma is 1 in 4000. In head and neck region congenital teratomas usually associated with other anomalies like cystic hygroma and cleft palate with an incidence of 1 in 400. The approximately reported incidence of palatal teratoma is 1 in 35000 to 40000 live-births. Upper airway difficulty causes anticipated functional problems at hypopharynx. The prognosis of palatal teratoma mostly depends on the risk and extent of neonatal respiratory distress. We present a rare case of congenital teratoma arising from the hard palate in a new born girl. The outcome in this case was bad due to the large mass causing respiratory difficulty and bleeding from the ruptured cystic areas leading to hypovolemic shock. After two hours of delivery, baby expired. PMID:27630855

  10. Molecular Profiling of a Rare Rosette-Forming Glioneuronal Tumor Arising in the Spinal Cord

    PubMed Central

    Bidinotto, Lucas Tadeu; Scapulatempo-Neto, Cristovam; Mackay, Alan; de Almeida, Gisele Caravina; Berardinelli, Gustavo Noriz; Torrieri, Raul; Clara, Carlos Afonso; Feltrin, Leonir Terezinha; Viana-Pereira, Marta; Varella-Garcia, Marileila; Jones, Chris; Reis, Rui Manuel

    2015-01-01

    Rosette-forming glioneuronal tumor (RGNT) of the IV ventricle is a rare and recently recognized brain tumor entity. It is histologically composed by two distinct features: a glial component, resembling pilocytic astrocytoma, and a component forming neurocytic rosettes and/or perivascular rosettes. Herein, we describe a 33-year-old man with RGNT arising in the spinal cord. Following an immunohistochemistry validation, we further performed an extensive genomic analysis, using array-CGH (aCGH), whole exome and cancer-related hotspot sequencing, in order to better understand its underlying biology. We observed the loss of 1p and gain of 1q, as well as gain of the whole chromosomes 7, 9 and 16. Local amplifications in 9q34.2 and 19p13.3 (encompassing the gene SBNO2) were identified. Moreover, we observed focal gains/losses in several chromosomes. Additionally, on chromosome 7, we identified the presence of the KIAA1549:BRAF gene fusion, which was further validated by RT-PCR and FISH. Across all mutational analyses, we detected and validated the somatic mutations of the genes MLL2, CNNM3, PCDHGC4 and SCN1A. Our comprehensive molecular profiling of this RGNT suggests that MAPK pathway and methylome changes, driven by KIAA1549:BRAF fusion and MLL2 mutation, respectively, could be associated with the development of this rare tumor entity. PMID:26371886

  11. Squamous Cell Carcinoma Arising from an Oral Lichenoid Lesion: A Case Report

    PubMed Central

    Taghavi Zenouz, Ali; Mehdipour, Masoumeh; Attaran, Rana; Bahramian, Ayla; Emamverdi Zadeh, Paria

    2012-01-01

    Lichenoid reactions represent a family of lesions with different etiologic factors and a common clinical and histologic ap-pearance. Lichen planus is included with lichenoid reactions and is a relatively common chronic mucocutaneous disorder. The most important complication of lichenoid reactions is the possibility of malignant transformation. That is why it has been considered a precancerous condition. Although the malignant transformation rate varies widely in the literature, from 0.4 to 6.5 percent, in most studies it does not exceed 1%. The aim of this paper is to report a rare case of squamous cell car-cinoma (SCC) arising within an oral lichenoid lesion in a 17-year-old woman, where SCC is very uncommon. The patient did not have any risk factors and was healthy. The lesion was located on the border of the tongue. In view of thecommon occurrence of OLP (oral lichen planus) and the unresolved issues regarding its premalignant potential, this case report illus-trates the need for histologic confirmation and a close follow-up of clinical lesions with lichenoid features. PMID:22991632

  12. Langerhans cell sarcoma arising from the root of tongue: a rare case

    PubMed Central

    Ren, Jian-Jun; Zhao, Yu; Liu, Ming-Juan; Liu, Guo; Chen, Fei

    2015-01-01

    Langerhans cell sarcoma (LCS), a rare malignant disease with markedly malignant cytological features and poor outcome, originates from Langerhans cells and most commonly affects the lymph nodes, skin, and bone. This paper presents the case of a 58-year-old female with LCS at the root of her tongue, with neither local recurrence nor distant metastasis observed during 47 months of follow up following radiotherapy for more than one month after complete tumor resection. Histological and immunophenotypic tests revealed that the malignant tumor cells were positive for S-100 protein, CD1a, and LCA, and partially positive for CD3ε. By contrast, the tumor cells were negative for langenin, CD30, HMB45, PCK, CK5/6, and P63. Their Ki-67proliferation index ranged from 30% to 40%. This neoplasm was diagnosed as LCS according to the classification of WHO2008. This work is the first report on LCS arising from the root of tongue. This rare case may serve as a reference for future clinical studies. PMID:26823886

  13. Molecular Profiling of a Rare Rosette-Forming Glioneuronal Tumor Arising in the Spinal Cord.

    PubMed

    Bidinotto, Lucas Tadeu; Scapulatempo-Neto, Cristovam; Mackay, Alan; de Almeida, Gisele Caravina; Scheithauer, Bernd Walter; Berardinelli, Gustavo Noriz; Torrieri, Raul; Clara, Carlos Afonso; Feltrin, Leonir Terezinha; Viana-Pereira, Marta; Varella-Garcia, Marileila; Jones, Chris; Reis, Rui Manuel

    2015-01-01

    Rosette-forming glioneuronal tumor (RGNT) of the IV ventricle is a rare and recently recognized brain tumor entity. It is histologically composed by two distinct features: a glial component, resembling pilocytic astrocytoma, and a component forming neurocytic rosettes and/or perivascular rosettes. Herein, we describe a 33-year-old man with RGNT arising in the spinal cord. Following an immunohistochemistry validation, we further performed an extensive genomic analysis, using array-CGH (aCGH), whole exome and cancer-related hotspot sequencing, in order to better understand its underlying biology. We observed the loss of 1p and gain of 1q, as well as gain of the whole chromosomes 7, 9 and 16. Local amplifications in 9q34.2 and 19p13.3 (encompassing the gene SBNO2) were identified. Moreover, we observed focal gains/losses in several chromosomes. Additionally, on chromosome 7, we identified the presence of the KIAA1549:BRAF gene fusion, which was further validated by RT-PCR and FISH. Across all mutational analyses, we detected and validated the somatic mutations of the genes MLL2, CNNM3, PCDHGC4 and SCN1A. Our comprehensive molecular profiling of this RGNT suggests that MAPK pathway and methylome changes, driven by KIAA1549:BRAF fusion and MLL2 mutation, respectively, could be associated with the development of this rare tumor entity. PMID:26371886

  14. Carcinoma arising in microglandular adenosis of the breast: triple negative phenotype with variable morphology.

    PubMed

    Zhong, Fangfang; Bi, Rui; Yu, Baohua; Cheng, Yufan; Xu, Xiaoli; Shui, Ruohong; Yang, Wentao

    2014-01-01

    Carcinoma arising in microglandular adenosis (MGACA) is an extremely rare subtype of breast carcinoma. In this study, clinicopathological analysis of MGACA from 11 Chinese patients was conducted. Microscopically, all cases showed a spectrum of structure and glandular proliferations ranging from microglandular adenosis (MGA) to atypical MGA (AMGA) to MGACA. Carcinoma components were composed of high grade ductal carcinoma in situ (DCIS) in 1 case and invasive carcinoma in 10 cases. Invasive carcinomas were grade 3 in 10 tumors and grade 2 in 1. Invasive components in 5 of 10 cases were composed of invasive carcinoma of no special type (NST), and 1 case showed partially acinic cell differentiation. In 5 cases, invasive components were mixed of NST and matrix-producing carcinoma (MPC). All epitheliums in 11 cases were triple negative (ER-, PR-, HER2-), and diffuse positive for CK and S-100 protein. No myoepithelial cells were demonstrable from MGA to invasive components with immunohistochemical staining for P63 and calponin. PAS or reticulin stain showed the presence of a basement membrane around glands in MGA, AMGA, DCIS, and its absence in invasive components. Follow-up time ranged from 10 to 64 months. One patient developed a lung metastasis 24 months after surgery, 10 patients have been alive without recurrence. Our study revealed that MGACA is a distinct subset of breast carcinoma, with triple negative phenotype, high grade nuclear and variable morphology. Despite histopathologic and immunohistochemical features usually associated with a poor prognosis, MGACA seems to have a relatively favorable outcome.

  15. Congenital Giant Teratoma Arising from the Hard Palate: A Rare Clinical Presentation

    PubMed Central

    Veligandla, Indira; Lakshmi, A.R.Vijaya; Pandey, Vanita

    2016-01-01

    Teratomas are rare tumours which originate from all 3 germs cell layers namely endoderm, mesoderm and ectoderm, with varying proportions of each component. The most common site of teratoma is in the sacro-coccygeal region. Teratomas are generally benign and have well appreciable clinical and histopathological features. Incidence of congenital teratoma is 1 in 4000. In head and neck region congenital teratomas usually associated with other anomalies like cystic hygroma and cleft palate with an incidence of 1 in 400. The approximately reported incidence of palatal teratoma is 1 in 35000 to 40000 live-births. Upper airway difficulty causes anticipated functional problems at hypopharynx. The prognosis of palatal teratoma mostly depends on the risk and extent of neonatal respiratory distress. We present a rare case of congenital teratoma arising from the hard palate in a new born girl. The outcome in this case was bad due to the large mass causing respiratory difficulty and bleeding from the ruptured cystic areas leading to hypovolemic shock. After two hours of delivery, baby expired.

  16. Ancient schwannoma arising from mental nerve. A case report and review.

    PubMed

    Subhashraj, Krishnaraj; Balanand, Subramanian; Pajaniammalle, Subhashraj

    2009-01-01

    Schwannoma is an intraoral rare, benign neoplasm derived from the nerve sheath of peripheral nerves. "Ancient schwannoma" shows histopathological features, such as degenerative changes and atypical nuclei, and may easily be confused with malignant neoplasms. Ancient schwannoma of the head and neck region is relatively uncommon and very few cases had been reported in the oral cavity. We present a case of ancient schwannoma arising from the mental nerve in a 19 year old male which was of eight months duration. Examination revealed a 30 x 25 mm firm, strawberry-like mass in the periapical region of the left lower first premolar, extending anteriorly to the canine and posteriorly to the first molar, obliterating the buccal vestibule, with an intact overlying mucosa. Ultrasonography showed that the tumor was closely associated with the mental nerve on the left side, suggestive of a peripheral neural sheath tumor. Complete excision of the lesion was done under local anesthesia, preserving the mental nerve. The histological picture was strongly suggestive of ancient schwannoma (Antoni A type). There was no evidence of recurrence 18 months after excision. The clinicopathological aspects of this special case are discussed, and the literature regarding this entity is reviewed. PMID:19114949

  17. Isolated primary central nervous system lymphoma arising from the optic chiasm.

    PubMed

    Vassal, F; Pommier, B; Boutet, C; Forest, F; Campolmi, N; Nuti, C

    2014-12-01

    A 58-year-old previously healthy woman rapidly developed progressive bilateral visual loss. Magnetic resonance imaging revealed a bulging appearance of the optic chiasm, with homogeneous enhancement after gadolinium administration, which suggested an optic glioma or inflammatory disease. In the absence of (para)clinical clues for a specific diagnosis despite extensive investigation, a biopsy of one optic nerve was performed, resulting in a diagnosis of non-Hodgkin B-cell lymphoma. There was no evidence of any other ocular or systemic involvement, therefore the conclusion was that this immunocompetent patient had a primary central nervous system lymphoma isolated in the anterior visual pathway. Treatment included two cycles of polychemotherapy (rituximab, methotrexate, carmustine, etoposide, methylprednisolone), followed by autologous peripheral blood stem cell transplantation and rituximab plus cytarabine consolidation therapy. Subsequently, the patient exhibited significant improvement in vision, and was still disease-free at the 1-year follow-up examination. The aim of the present paper was to provide well-documented clinical, radiological, and intraoperative features of isolated primary malignant lymphoma arising from the anterior visual pathway. A better recognition of this rare pathological entity is necessary for clinicians who may encounter similar presentations, as prompt management is crucial for both a visual and vital prognosis. PMID:25245922

  18. 31 CFR 535.335 - Claim arising out of events in Iran.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Claim arising out of events in Iran... General Definitions § 535.335 Claim arising out of events in Iran. For purposes of § 535.216, a claim is one “arising out of events” of the type specified only if such event is the specific act that is...

  19. 31 CFR 535.335 - Claim arising out of events in Iran.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Claim arising out of events in Iran... General Definitions § 535.335 Claim arising out of events in Iran. For purposes of § 535.216, a claim is one “arising out of events” of the type specified only if such event is the specific act that is...

  20. 31 CFR 535.335 - Claim arising out of events in Iran.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Claim arising out of events in Iran... General Definitions § 535.335 Claim arising out of events in Iran. For purposes of § 535.216, a claim is one “arising out of events” of the type specified only if such event is the specific act that is...

  1. Analyzing Water's Optical Absorption

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A cooperative agreement between World Precision Instruments (WPI), Inc., and Stennis Space Center has led the UltraPath(TM) device, which provides a more efficient method for analyzing the optical absorption of water samples at sea. UltraPath is a unique, high-performance absorbance spectrophotometer with user-selectable light path lengths. It is an ideal tool for any study requiring precise and highly sensitive spectroscopic determination of analytes, either in the laboratory or the field. As a low-cost, rugged, and portable system capable of high- sensitivity measurements in widely divergent waters, UltraPath will help scientists examine the role that coastal ocean environments play in the global carbon cycle. UltraPath(TM) is a trademark of World Precision Instruments, Inc. LWCC(TM) is a trademark of World Precision Instruments, Inc.

  2. Seismic features of Winnipegosis mounds in Saskatchewan

    SciTech Connect

    Gendzwill, D.J.

    1988-07-01

    The Winnipegosis Formation of southern Saskatchewan is characterized by reefs or reeflike mounds in its upper member. Several characteristic features of the mounds permit their identification from seismic-reflection data. These features include reflections from the flanks of the mound, a change in the reflection continuity in the middle and base of the mound, a velocity pullup under the mound, and subsidence of strata over the mound. Dissolution of the salt which surrounds the mounds sometimes occurs, resulting in a drape structure. Some or all of these features may be present at the correct seismic stratigraphic level for Winnipegosis mounds, depending on the local conditions. Subsidence of strata over the mounds indicates compaction and porosity loss from the original mound or possibly the degree of dolomitization or pressure dissolution. Salt-removal features over or adjacent to the mounds indicate fluid movements. Approximate ages can be estimated from stratigraphic thinning and thickening relationships above such features. Complications in identifying Winnipegosis mounds may arise from thin-bed effects if the mounds are not very thick compared to a seismic wavelength. Confusion may also arise from anhydrite, which may encase the mounds or which may form a thick horizontal layer at the tops of the mounds, causing an interfering signal.

  3. Percutaneous absorption in preterm infants.

    PubMed

    West, D P; Halket, J M; Harvey, D R; Hadgraft, J; Solomon, L M; Harper, J I

    1987-11-01

    The skin of preterm infants varies considerably in its level of maturity. To understand skin absorption in premature infants better, we report a technique for the assessment of percutaneous absorption at various gestational and postnatal ages using stable, isotope-labeled (13C6) benzoic acid. Our results indicate that in the preterm infant, this method detects enhanced skin absorption in the first postnatal days, which declines over three weeks to that expected of a full-term infant. This approach also indicates an inverse relationship between gestational age and skin absorption, as well as postnatal age and skin absorption. The reported technique is a safe and noninvasive method using a model skin penetrant for the study of percutaneous absorption in preterm infants from which basic data may be derived to add to our understanding of skin barrier function. PMID:3422856

  4. Broadening of absorption band by coupled gap plasmon resonances in a near-infrared metamaterial absorber

    NASA Astrophysics Data System (ADS)

    Cong, Jiawei; Yao, Hongbing; Gong, Daolei; Chen, Mingyang; Tong, Yanqun; Fu, Yonghong; Ren, Naifei

    2016-07-01

    We propose a strategy to broaden the absorption band of the conventional metamaterial absorber by incorporating alternating metal/dielectric films. Up to 7-fold increase in bandwidth and ∼95% average absorption are achieved arising from the coupling of induced multiple gap plasmon resonances. The resonance coupling is analytically demonstrated using the coupled oscillator model, which reveals that both the optimal coupling strength and the resonance wavelength matching are required for the enhancement of absorption bandwidth. The presented multilayer design is easily fabricated and readily implanted to other absorber configurations, offering a practical avenue for applications in photovoltaic cells and thermal emitters.

  5. Microwave absorption properties of carbon nanocoils coated with highly controlled magnetic materials by atomic layer deposition.

    PubMed

    Wang, Guizhen; Gao, Zhe; Tang, Shiwei; Chen, Chaoqiu; Duan, Feifei; Zhao, Shichao; Lin, Shiwei; Feng, Yuhong; Zhou, Lei; Qin, Yong

    2012-12-21

    In this work, atomic layer deposition is applied to coat carbon nanocoils with magnetic Fe(3)O(4) or Ni. The coatings have a uniform and highly controlled thickness. The coated nanocoils with coaxial multilayer nanostructures exhibit remarkably improved microwave absorption properties compared to the pristine carbon nanocoils. The enhanced absorption ability arises from the efficient complementarity between complex permittivity and permeability, chiral morphology, and multilayer structure of the products. This method can be extended to exploit other composite materials benefiting from its convenient control of the impedance matching and combination of dielectric-magnetic multiple loss mechanisms for microwave absorption applications.

  6. [Plant Spectral Discrimination Based on Phenological Features].

    PubMed

    Zhang, Lei; Zhao, Jian-long; Jia, Kun; Li, Xiao-song

    2015-10-01

    Spectral analysis plays a significant role onplant characteristic identification and mechanism recognition, there were many papers published on the aspects of absorption features in the spectra of chlorophyll and moisture, spectral analysis onvegetation red edge effect, spectra profile feature extraction, spectra profile conversion, vegetation leaf structure and chemical composition impacts on the spectra in past years. However, fewer researches issued on spectral changes caused by plant seasonal changes of life form, chlorophyll, leaf area index. This paper studied on spectral observation of 11 plants of various life form, plant leaf structure and its size, phenological characteristics, they include deciduous forest with broad vertical leaf, needle leaf evergreen forest, needle leaf deciduous forest, deciduous forest with broadflat leaf, high shrub with big leaf, high shrub with little leaf, deciduous forest with broad little leaf, short shrub, meadow, steppe and grass. Field spectral data were observed with SVC-HR768 (Spectra Vista company, USA), the band width covers 350-2 500 nm, spectral resolution reaches 1-4 nm. The features of NDVI, spectral maximum absorption depth in green band, and spectral maximum absorption depth in red band were measured after continuum removal processing, the mean, amplitude and gradient of these features on seasonal change profile were analyzed, meanwhile, separability research on plant spectral feature of growth period and maturation period were compared. The paper presents a calculation method of separability of vegetation spectra which consider feature spatial distances. This index is carried on analysis of the vegetation discrimination. The results show that: the spectral features during plant growth period are easier to distinguish than them during maturation period. With the same features comparison, plant separability of growth period is 3 points higher than it during maturation period. The overall separabilityof vegetation

  7. [Plant Spectral Discrimination Based on Phenological Features].

    PubMed

    Zhang, Lei; Zhao, Jian-long; Jia, Kun; Li, Xiao-song

    2015-10-01

    Spectral analysis plays a significant role onplant characteristic identification and mechanism recognition, there were many papers published on the aspects of absorption features in the spectra of chlorophyll and moisture, spectral analysis onvegetation red edge effect, spectra profile feature extraction, spectra profile conversion, vegetation leaf structure and chemical composition impacts on the spectra in past years. However, fewer researches issued on spectral changes caused by plant seasonal changes of life form, chlorophyll, leaf area index. This paper studied on spectral observation of 11 plants of various life form, plant leaf structure and its size, phenological characteristics, they include deciduous forest with broad vertical leaf, needle leaf evergreen forest, needle leaf deciduous forest, deciduous forest with broadflat leaf, high shrub with big leaf, high shrub with little leaf, deciduous forest with broad little leaf, short shrub, meadow, steppe and grass. Field spectral data were observed with SVC-HR768 (Spectra Vista company, USA), the band width covers 350-2 500 nm, spectral resolution reaches 1-4 nm. The features of NDVI, spectral maximum absorption depth in green band, and spectral maximum absorption depth in red band were measured after continuum removal processing, the mean, amplitude and gradient of these features on seasonal change profile were analyzed, meanwhile, separability research on plant spectral feature of growth period and maturation period were compared. The paper presents a calculation method of separability of vegetation spectra which consider feature spatial distances. This index is carried on analysis of the vegetation discrimination. The results show that: the spectral features during plant growth period are easier to distinguish than them during maturation period. With the same features comparison, plant separability of growth period is 3 points higher than it during maturation period. The overall separabilityof vegetation

  8. X-ray Absorption Spectroscopy

    SciTech Connect

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

    This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

  9. X-ray absorption and emission spectroscopy of Cr(III) (hydr)oxides: analysis of the K-pre-edge region.

    PubMed

    Frommer, Jakob; Nachtegaal, Maarten; Czekaj, Izabela; Weng, Tsu-Chien; Kretzschmar, Ruben

    2009-11-01

    Pre-edge spectral features below the main X-ray absorption K-edge of transition metals show a pronounced chemical sensitivity and are promising sources of structural information. Nevertheless, the use of pre-edge analysis in applied research is limited because of the lack of definite theoretical peak-assignments. The aim of this study was to determine the factors affecting the chromium K-pre-edge features in trivalent chromium-bearing oxides and oxyhydroxides. The selected phases varied in the degree of octahedral polymerization and the degree of iron-for-chromium substitution in the crystal structure. We investigated the pre-edge fine structure by means of high-energy-resolution fluorescence detected X-ray absorption spectroscopy and by 1s2p resonant X-ray emission spectroscopy. Multiplet theory and full multiple-scattering calculations were used to analyze the experimental data. We show that the chromium K-pre-edge contains localized and nonlocalized transitions. Contributions arising from nonlocalized metal-metal transitions are sensitive to the nearest metal type and to the linkage mode between neighboring metal octahedra. Analyzing these transitions opens up new opportunities for investigating the local coordination environment of chromium in poorly ordered solids of environmental relevance.

  10. 31 CFR 535.335 - Claim arising out of events in Iran.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Claim arising out of events in Iran. 535.335 Section 535.335 Money and Finance: Treasury Regulations Relating to Money and Finance... General Definitions § 535.335 Claim arising out of events in Iran. For purposes of § 535.216, a claim...

  11. 31 CFR 535.335 - Claim arising out of events in Iran.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Claim arising out of events in Iran. 535.335 Section 535.335 Money and Finance: Treasury Regulations Relating to Money and Finance... General Definitions § 535.335 Claim arising out of events in Iran. For purposes of § 535.216, a claim...

  12. Gas in scattering media absorption spectroscopy - GASMAS

    NASA Astrophysics Data System (ADS)

    Svanberg, Sune

    2008-09-01

    An overview of the new field of Gas in Scattering Media Absorption Spectroscopy (GASMAS) is presented. GASMAS combines narrow-band diode-laser spectroscopy with diffuse media optical propagation. While solids and liquids have broad absorption features, free gas in pores and cavities in the material is characterized by sharp spectral signatures, typically 10,000 times sharper than those of the host material. Many applications in materials science, food packaging, pharmaceutics and medicine have been demonstrated. So far molecular oxygen and water vapour have been studied around 760 and 935 nm, respectively. Liquid water, an important constituent in many natural materials, such as tissue, has a low absorption at such wavelengths, allowing propagation. Polystyrene foam, wood, fruits, food-stuffs, pharmaceutical tablets, and human sinus cavities have been studied. Transport of gas in porous media can readily be studied by first immersing the material in, e.g., pure nitrogen, and then observing the rate at which normal air, containing oxygen, reinvades the material. The conductance of the sinus connective passages can be measured in this way by flushing the nasal cavity with nitrogen. Also other dynamic processes such as drying of materials can be studied. The techniques have also been extended to remote-sensing applications (LIDAR-GASMAS).

  13. "Stirred, Not Shaken": Vibrational Coherence Can Speed Up Electronic Absorption.

    PubMed

    Chang, Bo Y; Shin, Seokmin; Sola, Ignacio R

    2015-08-27

    We have recently proposed a laser control scheme for ultrafast absorption in multilevel systems by parallel transfer (J. Phys. Chem. Lett. 2015, 6, 1724). In this work we develop an analytical model that better takes into account the main features of electronic absorption in molecules. We show that the initial vibrational coherence in the ground electronic state can be used to greatly enhance the rate and yield of absorption when ultrashort pulses are used, provided that the phases of the coherences are taken into account. On the contrary, the initial coherence plays no role in the opposite limit, when a single long pulse drives the optical transition. The theory is tested by numerical simulations in the first absorption band of Na2.

  14. H I absorption toward cooling flows in clusters of galaxies

    NASA Technical Reports Server (NTRS)

    Mcnamara, Brian R.; O'Connell, Robert W.; Bregman, Joel N.

    1990-01-01

    An H I survey of 14 cooling flow clusters and two noncooling flow clusters was conducted, and H I absorption features were detected against the nuclear radio continuum sources of two cooling flow dominant (CFD) galaxies, 2A 0335 + 096 and MKW3s. The absorption features are broad and redshifted with respect to the stellar absorption-line velocity of the CFDs by 90-225 km/s. This indicates that the H I is falling onto, and is probably gravitationally bound to, the CFDs. The kinematics of the H I clouds suggest a possible kinematic link between the warm and cold phases of the intracluster medium. The clouds are orders of magnitude smaller in radius and mass and larger in density than Galactic H I clouds. The detected CFDs have mass-accretion rates that are about 2.5 times larger than the CFDs that were not detected.

  15. Molecular hydrogen ion /H2+/ absorption in planetary nebulae

    NASA Technical Reports Server (NTRS)

    Feibelman, W. A.; Boggess, A.; Mccracken, C. W.; Hobbs, R. W.

    1981-01-01

    Several IUE spectra of planetary nebulae show an absorption feature shortward of 1500 A which is believed to be due to H2(+). The nebulae are excited by stars of spectral type O3-O7 or continuum, and all but one have double-shell structure.

  16. Subgap Absorption in Conjugated Polymers

    DOE R&D Accomplishments Database

    Sinclair, M.; Seager, C. H.; McBranch, D.; Heeger, A. J; Baker, G. L.

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10{sup {minus}5}, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of transparent'' materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination.

  17. Genomic Instability and DNA Damage Responses in Progeria Arising from Defective Maturation of Prelamin A

    PubMed Central

    Musich, Phillip R.; Zou, Yue

    2009-01-01

    Progeria syndromes have in common a premature aging phenotype and increased genome instability. The susceptibility to DNA damage arises from a compromised repair system, either in the repair proteins themselves or in the DNA damage response pathways. The most severe progerias stem from mutations affecting lamin A production, a filamentous protein of the nuclear lamina. Hutchinson-Gilford progeria syndrome (HGPS) patients are heterozygous for a LMNA gene mutation while Restrictive Dermopathy (RD) individuals have a homozygous deficiency in the processing protease Zmpste24. These mutations generate the mutant lamin A proteins progerin and FC-lamina A, respectively, which cause nuclear deformations and chromatin perturbations. Genome instability is observed even though genome maintenance and repair genes appear normal. The unresolved question is what features of the DNA damage response pathways are deficient in HGPS and RD cells. Here we review and discuss recent findings which resolve some mechanistic details of how the accumulation of progerin/FC-lamin A proteins may disrupt DNA damage response pathways in HGPS and RD cells. As the mutant lamin proteins accumulate they sequester replication and repair factors, leading to stalled replication forks which collapse into DNA double-strand beaks (DSBs). In a reaction unique to HGPS and RD cells these accessible DSB termini bind Xeroderma pigmentosum group A (XPA) protein which excludes normal binding by DNA DSB repair proteins. The bound XPA also signals activation of ATM and ATR, arresting cell cycle progression, leading to arrested growth. In addition, the effective sequestration of XPA at these DSB damage sites makes HGPS and RD cells more sensitive to ultraviolet light and other mutagens normally repaired by the nucleotide excision repair pathway of which XPA is a necessary and specific component. PMID:19851476

  18. Optical absorption of silicon nanowires

    SciTech Connect

    Xu, T.; Lambert, Y.; Krzeminski, C.; Grandidier, B.; Stievenard, D.; Leveque, G.; Akjouj, A.; Pennec, Y.; Djafari-Rouhani, B.

    2012-08-01

    We report on simulations and measurements of the optical absorption of silicon nanowires (NWs) versus their diameter. We first address the simulation of the optical absorption based on two different theoretical methods: the first one, based on the Green function formalism, is useful to calculate the scattering and absorption properties of a single or a finite set of NWs. The second one, based on the finite difference time domain (FDTD) method, is well-adapted to deal with a periodic set of NWs. In both cases, an increase of the onset energy for the absorption is found with increasing diameter. Such effect is experimentally illustrated, when photoconductivity measurements are performed on single tapered Si nanowires connected between a set of several electrodes. An increase of the nanowire diameter reveals a spectral shift of the photocurrent intensity peak towards lower photon energies that allow to tune the absorption onset from the ultraviolet radiations to the visible light spectrum.

  19. [Compatible low target feature coatings].

    PubMed

    Huang, Wei; Gao, Hai-chao; Dai, Song-tao

    2008-09-01

    Indium tin oxide (ITO) film has low reflectance in near infrared band while high reflectance in infrared band, and its dielectric constant can be described by Drude free-electron model. SiO film has very strong absorption at certain infrared wavelength By combining them, certain spectral selectivity can be realized. In the present paper, the authors investigated SiO/ITO films in terms of spectrum selectivity, and discussed the influence of film structure on reflection spectrum. By means of the computation of reflection spectrum with characteristic matrix, the authors found that SiO/ITO film can be used as a compatible infrared low target feature coating by properly adjusting film arrangement and selecting suitable film parameters.

  20. Gas-absorption process

    DOEpatents

    Stephenson, Michael J.; Eby, Robert S.

    1978-01-01

    This invention is an improved gas-absorption process for the recovery of a desired component from a feed-gas mixture containing the same. In the preferred form of the invention, the process operations are conducted in a closed-loop system including a gas-liquid contacting column having upper, intermediate, and lower contacting zones. A liquid absorbent for the desired component is circulated through the loop, being passed downwardly through the column, regenerated, withdrawn from a reboiler, and then recycled to the column. A novel technique is employed to concentrate the desired component in a narrow section of the intermediate zone. This technique comprises maintaining the temperature of the liquid-phase input to the intermediate zone at a sufficiently lower value than that of the gas-phase input to the zone to effect condensation of a major part of the absorbent-vapor upflow to the section. This establishes a steep temperature gradient in the section. The stripping factors below this section are selected to ensure that virtually all of the gases in the downflowing absorbent from the section are desorbed. The stripping factors above the section are selected to ensure re-dissolution of the desired component but not the less-soluble diluent gases. As a result, a peak concentration of the desired component is established in the section, and gas rich in that component can be withdrawn therefrom. The new process provides important advantages. The chief advantage is that the process operations can be conducted in a single column in which the contacting zones operate at essentially the same pressure.

  1. Intestinal Folate Absorption

    PubMed Central

    Olinger, Edward J.; Bertino, Joseph R.; Binder, Henry J.

    1973-01-01

    These studies were designed to determine whether pteroylmonoglutamic acid (PGA) at physiologic concentrations is transported across the small intestine unaltered or is reduced and methylated to the circulating folate form (5-methyltetrahydrofolate [5-MeFH4]) during absorption. [3H]PGA was incubated in vitro on the mucosal side of rat jejunum. Of the folate transferred to the serosal side, the percent identified as 5-MeFH4 by DEAE-Sephadex chromtography was inversely related to the initial mucosa PGA concentration: at 7, 20, and 2,000 nM, 44%, 34%, and 2%, respectively, was converted to 5-MeFH4. In contrast, less than 4% of the folate transferred across ileal mucosa was 5-MeFH4 when the initial mucosa concentration was 20 nM. Specific activity of dihydrofolate (DHF) reductase, the enzyme responsible for converting PGA to tetrahydrofolic acid, was measured in villus homogenates and was significantly greater in the jejunum than in the ileum. 1,000 nM methotrexate (MTX), a DHF reductase inhibitor, markedly inhibited PGA conversion to 5-MeFH4 by the jejunum. Studies of transmural flux, initial rate of mucosal entry (influx) and mucosal accumulation (uptake) of folate were also performed. Although MTX did not alter the influx of PGA, MTX decreased jejunal mucosal uptake but increased transmural movement. Transmural folate movement across ileal mucosa was greater than across jejunal mucosa although mucosal uptake was greater in the jejunum than in the ileum. These results could explain previous studies which have failed to identify conversion of PGA to 5-MeFH4 when intestinal preparations have been exposed to higher and less physiologic concentrations of PGA. Further, these studies suggest that 5-MeFH4 may be retained by the jejunal mucosa. PMID:4727453

  2. On Wolf-Rayet stars with unshifted absorption lines

    NASA Astrophysics Data System (ADS)

    Moffat, A. F. J.; Lamontagne, R.; Shara, M. M.; McAlister, H. A.

    1986-06-01

    The authors examine a sample of 16 galactic Wolf-Rayet stars that exhibit unshifted absorption lines, but for which orbital motion involving the WR star and an O-type companion is either unknown or thought to be absent. If all of these are binaries, this would increase the estimate of the binary frequency for WR stars by about 10%. Speckle interferometry of three bright non-WNL+abs stars in Cygnus fails to reveal any astrometric companions down to a separation of 0.05arcsec. Thus, either the absorption lines are intrinsic to the WR star in these three cases or, more likely, they arise in a bound companion. The search for wide spectroscopic orbits for WR 137 and the WN3+abs star WR 3 is re-examined.

  3. Near-edge X-ray absorption fine-structure spectroscopy of naphthalene diimide-thiophene co-polymers

    SciTech Connect

    Gann, Eliot; McNeill, Christopher R.; Szumilo, Monika; Sirringhaus, Henning; Sommer, Michael; Maniam, Subashani; Langford, Steven J.; Thomsen, Lars

    2014-04-28

    Near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy is an important tool for probing the structure of conjugated polymer films used in organic electronic devices. High-performance conjugated polymers are often donor-acceptor co-polymers which feature a repeat unit with multiple functional groups. To facilitate better application of NEXAFS spectroscopy to the study of such materials, improved understanding of the observed NEXAFS spectral features is required. In order to examine how the NEXAFS spectrum of a donor-acceptor co-polymer relates to the properties of the sub-units, a series of naphthalene diimide-thiophene-based co-polymers have been studied where the nature and length of the donor co-monomer has been systematically varied. The spectra of these materials are compared with that of a thiophene homopolymer and naphthalene diimide monomer enabling peak assignment and the influence of inter-unit electronic coupling to be assessed. We find that while it is possible to attribute peaks within the π* manifold as arising primarily due to the naphthalene diimide or thiophene sub-units, very similar dichroism of these peaks is observed indicating that it may not be possible to separately probe the molecular orientation of the separate sub-units with carbon K-edge NEXAFS spectroscopy.

  4. Gastrointestinal citrate absorption in nephrolithiasis

    NASA Technical Reports Server (NTRS)

    Fegan, J.; Khan, R.; Poindexter, J.; Pak, C. Y.

    1992-01-01

    Gastrointestinal absorption of citrate was measured in stone patients with idiopathic hypocitraturia to determine if citrate malabsorption could account for low urinary citrate. Citrate absorption was measured directly from recovery of orally administered potassium citrate (40 mEq.) in the intestinal lavage fluid, using an intestinal washout technique. In 7 stone patients citrate absorption, serum citrate levels, peak citrate concentration in serum and area under the curve were not significantly different from those of 7 normal subjects. Citrate absorption was rapid and efficient in both groups, with 96 to 98% absorbed within 3 hours. The absorption of citrate was less efficient from a tablet preparation of potassium citrate than from a liquid preparation, probably due to a delayed release of citrate from wax matrix. However, citrate absorption from solid potassium citrate was still high at 91%, compared to 98% for a liquid preparation. Thus, hypocitraturia is unlikely to be due to an impaired gastrointestinal absorption of citrate in stone patients without overt bowel disease.

  5. Percutaneous absorption of Octopirox.

    PubMed

    Black, J G; Kamat, V B

    1988-01-01

    containing 1% Octopirox is 29,400, so that the possibility of systemic effects due to absorption through the skin is remote. PMID:3345970

  6. Carcinoma Arising in Microglandular Adenosis: An Immunohistochemical Analysis of 20 Intraepithelial and Invasive Neoplasms.

    PubMed

    Koenig, Christopher; Dadmanesh, Farnaz; Bratthauer, Gary L.; Tavassoli, Fattaneh A.

    2000-10-01

    useful stains in difficult cases. Except for a single case, ER and PR were negative in all lesions. Cytokeratin 7 (CK 7) was positive, while cytokeratin 20 (CK 20) was negative in all cases. Immunostains for CK903 showed no reactivity in any of the invasive carcinomas, in situ carcinomas, or atypical MGA but was focally present in the associated MGA in 2 of the 8 cases studied. Immunostains for MIB-1 and p53 were semiquantitatively assessed and both were positive in AMGA but tended to show a more intense staining in the carcinomas. Five cases were also studied for immunoexpression of alpha-1 antitrypsin (AAT), alpha-1 antichymotrypsin (ACTP), lysozyme, and salivary gland amylase. All 5 invasive carcinomas were positive for ACTP, though the staining was very focal in about 10% of the cells in a basaloid carcinoma. The in situ carcinoma as well as the AMGA in 4 of the 5 cases were positive for ACTP. Three of the 5 invasive carcinomas were positive for AAT in 10% to 40% of the cells. The most intense positivity for AAT and ACTP was in cells with coarsely granular apocrine appearance evident in 2 of the 5 cases. Four of the 5 invasive carcinomas were positive for lysozyme in 10% to 50% of the cancer cells; the in situ carcinoma and the associated AMGA showed similar immunoreaction in each case. None of the 5 cases showed convincing positivity for salivary gland amylase. The MGA in all 5 cases was negative for AAT and ACTP; the MGA in 1 of the 5 cases was positive for lysozyme. This study confirms the potential of MGA to develop into an invasive carcinoma, more clearly defines the features of AMGA, highlights the importance of AMGA in the evolution of carcinoma from MGA, and expands our knowledge of the immunophenotype of AMGA and the carcinomas arising from it. The diagnostic criteria briefly noted previously for diagnosis of AMGA and carcinoma arising in MGA are expanded and formally proposed. Int J Surg Pathol 8(4):303-315, 2000

  7. Resonant Absorption of Bessel Beams

    NASA Astrophysics Data System (ADS)

    Fan, J.; Parra, E.; Milchberg, H. M.

    1999-11-01

    We report the first observation of enhanced laser-plasma optical absorption in a subcritical density plasma resulting from spatial resonances, here in the laser breakdown of a gas with a Bessel beam. The enhancement in absorption is directly correlated to enhancements both in confinement of laser radiation to the plasma and in its heating. Under certain conditions, azimuthal asymmetry in the laser beam is essential for efficient gas breakdown. Simulations of this absorption consistently explain the experimental observations. This work is supported by the National Science Foundation (PHY-9515509) and the US Department of Energy (DEF G0297 ER 41039).

  8. Light absorption measurements: new techniques.

    PubMed

    Hänel, G; Busen, R; Hillenbrand, C; Schloss, R

    1982-02-01

    A new radiometer is described which simplifies measurement of the radiation supply of solar wavelengths. Two methods of measuring the radiant energy absorbed by aerosol particles are described: A photometric technique is used for particles collected on filters, and a calorimetric technique is used for in situ measurements. Data collected with the radiometer and the light absorption techniques yield the heating rate of the atmosphere due to light absorption by the particles. Sample measurements show substantial atmospheric temperature increases due to absorption, especially in industrial regions.

  9. Diagnostic potential of cosmic-neutrino absorption spectroscopy

    SciTech Connect

    Barenboim, Gabriela; Mena Requejo, Olga; Quigg, Chris; /Fermilab

    2004-12-01

    Annihilation of extremely energetic cosmic neutrinos on the relic-neutrino background can give rise to absorption lines at energies corresponding to formation of the electroweak gauge boson Z{sup 0}. The positions of the absorption dips are set by the masses of the relic neutrinos. Suitably intense sources of extremely energetic (10{sup 21} - 10{sup 25}-eV) cosmic neutrinos might therefore enable the determination of the absolute neutrino masses and the flavor composition of the mass eigenstates. Several factors--other than neutrino mass and composition--distort the absorption lines, however. We analyze the influence of the time-evolution of the relic-neutrino density and the consequences of neutrino decay. We consider the sensitivity of the lineshape to the age and character of extremely energetic neutrino sources, and to the thermal history of the Universe, reflected in the expansion rate. We take into account Fermi motion arising from the thermal distribution of the relic-neutrino gas. We also note the implications of Dirac vs. Majorana relics, and briefly consider unconventional neutrino histories. We ask what kinds of external information would enhance the potential of cosmic-neutrino absorption spectroscopy, and estimate the sensitivity required to make the technique a reality.

  10. Photonic band-edge-induced enhancement in absorption and emission

    NASA Astrophysics Data System (ADS)

    Ummer, Karikkuzhi Variyath; Vijaya, Ramarao

    2015-01-01

    An enhancement in photonic band-edge-induced absorption and emission from rhodamine-B dye doped polystyrene pseudo gap photonic crystals is studied. The band-edge-induced enhancement in absorption is achieved by selecting the incident angle of the excitation beam so that the absorption spectrum of the emitter overlaps the photonic band edge. The band-edge-induced enhancement in emission, on the other hand, is possible with and without an enhancement in band-edge-induced absorption, depending on the collection angle of emission. Through a simple set of measurements with suitably chosen angles for excitation and emission, we achieve a maximum enhancement of 70% in emission intensity with band-edge-induced effects over and above the intrinsic emission in the case of self-assembled opals. This is a comprehensive effort to interpret tunable lasing in opals as well as to predict the wavelength of lasing arising as a result of band-edge-induced distributed feedback effects.

  11. Systemic lymphoma arising from hydroa vacciniforme-like lymphoma: report of two cases with review of literature

    PubMed Central

    Yang, Yu-Qiong; Fan, Lei; Wang, Li; Xu, Ji; Zhang, Run; Ge, Zheng; Li, Jian-Yong; Xu, Wei

    2014-01-01

    Hydroa vacciniforme-like lymphoma (HVLL) is an extremely rare lymphoma described in children that occurs mainly in Asia and Latin American countries. It is an Epstein-Barr virus (EBV)-positive lymphoproliferative disease (LPD) characterized by a monoclonal proliferation of T or NK cells. In this study, we report the clinical and pathological features of two Chinese patients with HVLL showed T-cell phenotype expressing CD4. The two patients generally presented with similar clinical histories of waxing and waning ulcerative blistering lesions for ten years or more until progression to systemic lymphoma. One patient died two months after progression and another is alive with disease. In the two cases, persistence infection of EBV may be attributed to the disease progression, and systemic lymphoma arising from HVLL behaves in an aggressive fashion and is predisposing to chemotherapeutic agent resistance. PMID:25337300

  12. Epithelial Dysplasia in Ameloblastic Fibrosarcoma Arising from Recurrent Ameloblastic Fibroma in a 26-Year-Old Iranian Man

    PubMed Central

    Mohsenifar, Zhaleh; Behrad, Samira; Abbas, Fatemeh Mashhadi

    2015-01-01

    Patient: Male, 26 Final Diagnosis: Ameloblastic fibrosarcoma Symptoms: Swelling Medication: — Clinical Procedure: Hemimandibulectomy Specialty: Dentistry Objective: Rare disease Background: Ameloblastic fibrosarcoma (AFS) is a rare malignant odontogenic tumor with a mesenchymal component, showing sarcomatous features and epithelial nests resembling ameloblastic fibroma (AF). Case Report: We report a case of AFS showing epithelial dysplasia arising in a recurrent AF in the left mandible after 3 years in a 26-year-old man, which is regarded as an uncommon histopathologic finding in AFS. We also emphasize the comprehensive clinical, radiographic, and histopathologic evaluation, and immunohistochemical staining of this patient. Conclusions: We conclude that it is important to consider malignancy alternations in the epithelial component of AFS, along with that of the mesenchymal component, to provide a proper diagnosis and treatment of recurrent AF. PMID:26289384

  13. 32 CFR 536.115 - Claims procedures for claims arising overseas under international agreements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... otherwise allowed under the FCA or MCA. For example, receiving state claims offices in Germany require that....S. involvement. If the filing period is about to expire for claims arising in Germany, have...

  14. 32 CFR 536.115 - Claims procedures for claims arising overseas under international agreements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... otherwise allowed under the FCA or MCA. For example, receiving state claims offices in Germany require that....S. involvement. If the filing period is about to expire for claims arising in Germany, have...

  15. 32 CFR 536.115 - Claims procedures for claims arising overseas under international agreements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... otherwise allowed under the FCA or MCA. For example, receiving state claims offices in Germany require that....S. involvement. If the filing period is about to expire for claims arising in Germany, have...

  16. 32 CFR 536.115 - Claims procedures for claims arising overseas under international agreements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... otherwise allowed under the FCA or MCA. For example, receiving state claims offices in Germany require that....S. involvement. If the filing period is about to expire for claims arising in Germany, have...

  17. 32 CFR 536.115 - Claims procedures for claims arising overseas under international agreements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... otherwise allowed under the FCA or MCA. For example, receiving state claims offices in Germany require that....S. involvement. If the filing period is about to expire for claims arising in Germany, have...

  18. Case report 207: Giant cell reparative granuloma of left femur arising in polyostatic fibrous dysplasia

    SciTech Connect

    De Smet, A.A.; Travers, H.; Neff, J.R.

    1982-08-01

    Diagnosis and differential diagnosis of lytic lesions in the femur are discussed. Roentgenograms, a tomogram and pathological studies of a giant cell reparative granuloma of left femur arising in polyostotic fibrous dysplasia are presented.

  19. Right aortic arch with aberrant left innominate artery arising from Kommerell's diverticulum*

    PubMed Central

    Faistauer, Ângela; Torres, Felipe Soares; Faccin, Carlo Sasso

    2016-01-01

    We report a case of an uncommon thoracic aorta anomaly-right aortic arch with aberrant left innominate artery arising from Kommerell's diverticulum-that went undiagnosed until adulthood. PMID:27777481

  20. A pair of Fibonacci-like polynomials arising from a special mapping

    NASA Astrophysics Data System (ADS)

    Griffiths, Martin; Griffiths, Jonny

    2016-02-01

    We study here a pair of sequences of polynomials that arise from a particular iterated mapping on the plane. We show how these sequences come about, and give some of their interesting mathematical properties.

  1. Variational iteration method for Bratu-like equation arising in electrospinning.

    PubMed

    He, Ji-Huan; Kong, Hai-Yan; Chen, Rou-Xi; Hu, Ming-sheng; Chen, Qiao-ling

    2014-05-25

    This paper points out that the so called enhanced variational iteration method (Colantoni & Boubaker, 2014) for a nonlinear equation arising in electrospinning and vibration-electrospinning process is the standard variational iteration method. An effective algorithm using the variational iteration algorithm-II is suggested for Bratu-like equation arising in electrospinning. A suitable choice of initial guess results in a relatively accurate solution by one or few iteration.

  2. Variations in the Absorption Lines Associated with SN 1006

    NASA Astrophysics Data System (ADS)

    Fesen, Robert A.

    Analysis of 8th year IUE data for a faint sdOB star situated behind the young and suspected Type I supernova remnant of AD 1006 together with a careful re-analysis of earlier IUE spectra (Wu et al. 1983) confirm the presence of several very strong and definitely non-stellar absorption lines in this star's UV spectrum (Fesen, Wu, Leventhal, and Hamilton 1986). Exceedingly broad and strong absorption features at 2370 and 2600 A agree well with the relative strengths and wavelengths of the Fe II 2343, 2382, and 2599 A resonance lines and indicate an Fe II mass of about 0.1 solar mass. Other strong absorption features at 1282, 1331, and 1420 A are identified as redshifted S II (1259, 1254), O I (1302), and Si IV (1393, 1402) respectively with radial velocities of 5000 to 6700 km s^-1. The UV spectra of this sdOB star has provided us with an exciting and invaluable observational probe of the elemental composition and dynamical properties of a young Type I supernova remnant via the line-of-sight interception of the remnant's outer ejecta knots and expanding central iron core. The elements, ionization, and velocities implied by these absorption lines are in good agreement with both optical spectral features seen in Type I SN as well as detailed model calculations predicting the final explosive nucleosynthesis production and expansion velocities. Importantly however, some absorption line variations are seen between the 1982/83 and 1986 IUE spectra. Indeed, if the 1282, 1331, and 1420 A features are really due to knots of ejecta with dimensions similar to those of other remnants (i.e., 0.01 pc), these features cannot persist or remain unchanged over time scales greater than a few years. In order to understand fully the nature of the remnant's ejecta, we propose to monitor these changes in these absorption features over the next two IUE observing seasons (1987/88 and 1988/89). The exposure times are well known with the data reduction and analysis already established and

  3. SELF-ABSORPTION IN THE SOLAR TRANSITION REGION

    SciTech Connect

    Yan, Limei; He, Jiansen; Wang, Linghua; Tu, Chuanyi; Zhang, Lei; Peter, Hardi; Chen, Feng; Barczynski, Krzysztof; Tian, Hui; Xia, Lidong

    2015-09-20

    Transient brightenings in the transition region of the Sun have been studied for decades and are usually related to magnetic reconnection. Recently, absorption features due to chromospheric lines have been identified in transition region emission lines raising the question of the thermal stratification during such reconnection events. We analyze data from the Interface Region Imaging Spectrograph in an emerging active region. Here the spectral profiles show clear self-absorption features in the transition region lines of Si iv. While some indications existed that opacity effects might play some role in strong transition region lines, self-absorption has not been observed before. We show why previous instruments could not observe such self-absorption features, and discuss some implications of this observation for the corresponding structure of reconnection events in the atmosphere. Based on this we speculate that a range of phenomena, such as explosive events, blinkers or Ellerman bombs, are just different aspects of the same reconnection event occurring at different heights in the atmosphere.

  4. Percutaneous nitroglycerin absorption in rats.

    PubMed

    Horhota, S T; Fung, H L

    1979-05-01

    Percutaneous nitroglycerin absorption was studied in shaved rats by monitoring unchanged plasma drug concentrations for up to 4 hr. Drug absorption from the neat liquid state or from an alcoholic solution was considerably poorer than that from a commercial ointment. This observation was unanticipated since the driving force for percutaneous drug absorption was assumed to be drug thermodynamics. Potential artifacts such as drug volatilization from the skin, reduction of surface area through droplet formation, and vehicle occlusion were investigated, but they did not appear to be responsible for the observed results. Two experimental aqueous nitroglycerin gels were prepared with polyethylene glycol 400. One gel contained just sufficient polyethylene glycol to solubilize the nitroglycerin; the other had excess polyethylene glycol to solubilize nitroglycerin far below saturation. Both gels gave extremely low plasma nitroglycerin levels. The composite data suggested that percutaneous nitroglycerin absorption is highly vehicle dependent and that this dependency cannot be explained by simple consideration of drug thermodynamic activity.

  5. Circadian Regulation of Macronutrient Absorption.

    PubMed

    Hussain, M Mahmood; Pan, Xiaoyue

    2015-12-01

    Various intestinal functions exhibit circadian rhythmicity. Disruptions in these rhythms as in shift workers and transcontinental travelers are associated with intestinal discomfort. Circadian rhythms are controlled at the molecular level by core clock and clock-controlled genes. These clock genes are expressed in intestinal cells, suggesting that they might participate in the circadian regulation of intestinal functions. A major function of the intestine is nutrient absorption. Here, we will review absorption of proteins, carbohydrates, and lipids and circadian regulation of various transporters involved in their absorption. A better understanding of circadian regulation of intestinal absorption might help control several metabolic disorders and attenuate intestinal discomfort associated with disruptions in sleep-wake cycles.

  6. A SURVEY OF ALKALI LINE ABSORPTION IN EXOPLANETARY ATMOSPHERES

    SciTech Connect

    Jensen, Adam G.; Redfield, Seth; Endl, Michael; Cochran, William D.; Koesterke, Lars; Barman, Travis S. E-mail: sredfield@wesleyan.edu E-mail: wdc@astro.as.utexas.edu E-mail: barman@lowell.edu

    2011-12-20

    We obtained over 90 hr of spectroscopic observations of four exoplanetary systems with the Hobby-Eberly Telescope. Observations were taken in transit and out of transit, and we analyzed the differenced spectra-i.e., the transmission spectra-to inspect it for absorption at the wavelengths of the neutral sodium (Na I) doublet at {lambda}{lambda}5889, 5895 and neutral potassium (K I) at {lambda}7698. We used the transmission spectrum at Ca I {lambda}6122-which shows strong stellar absorption but is not an alkali metal resonance line that we expect to show significant absorption in these atmospheres-as a control line to examine our measurements for systematic errors. We use an empirical Monte Carlo method to quantify these systematic errors. In a reanalysis of the same data set using a reduction and analysis pipeline that was derived independently, we confirm the previously seen Na I absorption in HD 189733b at a level of (- 5.26 {+-} 1.69) Multiplication-Sign 10{sup -4} (the average value over a 12 A integration band to be consistent with previous authors). Additionally, we tentatively confirm the Na I absorption seen in HD 209458b (independently by multiple authors) at a level of (- 2.63 {+-} 0.81) Multiplication-Sign 10{sup -4}, though the interpretation is less clear. Furthermore, we find Na I absorption of (- 3.16 {+-} 2.06) Multiplication-Sign 10{sup -4} at <3{sigma} in HD 149026b; features apparent in the transmission spectrum are consistent with real absorption and indicate this may be a good target for future observations to confirm. No other results (Na I in HD 147506b and Ca I and K I in all four targets) are significant to {>=}3{sigma}, although we observe some features that we argue are primarily artifacts.

  7. Scramjet Performance Assessment Using Water Absorption Diagnostics (U)

    NASA Technical Reports Server (NTRS)

    Cavolowsky, John A.; Loomis, Mark P.; Deiwert, George

    1995-01-01

    Simultaneous multiple path measurements of temperature and H2O concentration will be presented for the AIMHYE test entries in the NASA Ames 16-Inch Shock Tunnel. Monitoring the progress of high temperature chemical reactions that define scramjet combustor efficiencies is a task uniquely suited to nonintrusive optical diagnostics. One application strategy to overcome the many challenges and limitations of nonintrusive measurements is to use laser absorption spectroscopy coupled with optical fibers. Absorption spectroscopic techniques with rapidly tunable lasers are capable of making simultaneous measurements of mole fraction, temperature, pressure, and velocity. The scramjet water absorption diagnostic was used to measure combustor efficiency and was compared to thrust measurements using a nozzle force balance and integrated nozzle pressures to develop a direct technique for evaluating integrated scramjet performance. Tests were initially performed with a diode laser tuning over a water absorption feature at 1391.7 nm. A second diode laser later became available at a wavelength near 1343.3 nm covering an additional water absorption feature and was incorporated in the system for a two-wavelength technique. Both temperature and mole fraction can be inferred from the lineshape analysis using this approach. Additional high temperature spectroscopy research was conducted to reduce uncertainties in the scramjet application. The lasers are optical fiber coupled to ports at the combustor exit and in the nozzle region. The output from the two diode lasers were combined in a single fiber, and the resultant two-wavelength beam was subsequently split into four legs. Each leg was directed through 60 meters of optical fiber to four combustor exit locations for measurement of beam intensity after absorption by the water within the flow. Absorption results will be compared to 1D combustor analysis using RJPA and nozzle CFD computations as well as to data from a nozzle metric

  8. Transition state region in the A-Band photodissociation of allyl iodide--A femtosecond extreme ultraviolet transient absorption study.

    PubMed

    Bhattacherjee, Aditi; Attar, Andrew R; Leone, Stephen R

    2016-03-28

    Femtosecond extreme ultraviolet (XUV) transient absorption spectroscopy based on a high-harmonic generation source is used to study the 266 nm induced A-band photodissociation dynamics of allyl iodide (CH2 =CHCH2I). The photolysis of the C-I bond at this wavelength produces iodine atoms both in the ground ((2)P3/2, I) and spin-orbit excited ((2)P1/2, I*) states, with the latter as the predominant channel. Using XUV absorption at the iodine N4/5 edge (45-60 eV), the experiments constitute a direct probe of not only the long-lived atomic iodine reaction products but also the fleeting transition state region of the repulsive nIσ(∗) C-I excited states. Specifically, three distinct features are identified in the XUV transient absorption spectrum at 45.3 eV, 47.4 eV, and 48.4 eV (denoted transients A, B, and C, respectively), which arise from the repulsive valence-excited nσ(∗) states and project onto the high-lying core-excited states of the dissociating molecule via excitation of 4d(I) core electrons. Transients A and B originate from 4d(I) → n(I) core-to-valence transitions, whereas transient C is best assigned to a 4d(I) →σ(∗)(C-I) transition. The measured differential absorbance of these new features along with the I/I* branching ratios known from the literature is used to suggest a more definitive assignment, albeit provisional, of the transients to specific dissociative states within the A-band manifold. The transients are found to peak around 55 fs-65 fs and decay completely by 145 fs-185 fs, demonstrating the ability of XUV spectroscopy to map the evolution of reactants into products in real time. The similarity in the energies of transients A and B with analogous features observed in methyl iodide [Attar et al. J. Phys. Chem. Lett. 6, 5072, (2015)] together with the new observation of transient C in the present work provides a more complete picture of the valence electronic structure in the transition state region. The results provide a benchmark

  9. Transition state region in the A-Band photodissociation of allyl iodide—A femtosecond extreme ultraviolet transient absorption study

    NASA Astrophysics Data System (ADS)

    Bhattacherjee, Aditi; Attar, Andrew R.; Leone, Stephen R.

    2016-03-01

    Femtosecond extreme ultraviolet (XUV) transient absorption spectroscopy based on a high-harmonic generation source is used to study the 266 nm induced A-band photodissociation dynamics of allyl iodide (CH2 =CHCH2I). The photolysis of the C—I bond at this wavelength produces iodine atoms both in the ground (2P3/2, I) and spin-orbit excited (2P1/2, I*) states, with the latter as the predominant channel. Using XUV absorption at the iodine N4/5 edge (45-60 eV), the experiments constitute a direct probe of not only the long-lived atomic iodine reaction products but also the fleeting transition state region of the repulsive nIσ∗C—I excited states. Specifically, three distinct features are identified in the XUV transient absorption spectrum at 45.3 eV, 47.4 eV, and 48.4 eV (denoted transients A, B, and C, respectively), which arise from the repulsive valence-excited nσ∗ states and project onto the high-lying core-excited states of the dissociating molecule via excitation of 4d(I) core electrons. Transients A and B originate from 4d(I) → n(I) core-to-valence transitions, whereas transient C is best assigned to a 4d(I) →σ∗(C—I) transition. The measured differential absorbance of these new features along with the I/I* branching ratios known from the literature is used to suggest a more definitive assignment, albeit provisional, of the transients to specific dissociative states within the A-band manifold. The transients are found to peak around 55 fs-65 fs and decay completely by 145 fs-185 fs, demonstrating the ability of XUV spectroscopy to map the evolution of reactants into products in real time. The similarity in the energies of transients A and B with analogous features observed in methyl iodide [Attar et al. J. Phys. Chem. Lett. 6, 5072, (2015)] together with the new observation of transient C in the present work provides a more complete picture of the valence electronic structure in the transition state region. The results provide a benchmark for

  10. Incomplete intestinal absorption of fructose.

    PubMed

    Kneepkens, C M; Vonk, R J; Fernandes, J

    1984-08-01

    Intestinal D-fructose absorption in 31 children was investigated using measurements of breath hydrogen. Twenty five children had no abdominal symptoms and six had functional bowel disorders. After ingestion of fructose (2 g/kg bodyweight), 22 children (71%) showed a breath hydrogen increase of more than 10 ppm over basal values, indicating incomplete absorption: the increase averaged 53 ppm, range 12 to 250 ppm. Four of these children experienced abdominal symptoms. Three of the six children with bowel disorders showed incomplete absorption. Seven children were tested again with an equal amount of glucose, and in three of them also of galactose, added to the fructose. The mean maximum breath hydrogen increases were 5 and 10 ppm, respectively, compared with 103 ppm after fructose alone. In one boy several tests were performed with various sugars; fructose was the only sugar incompletely absorbed, and the effect of glucose on fructose absorption was shown to be dependent on the amount added. It is concluded that children have a limited absorptive capacity for fructose. We speculate that the enhancing effect of glucose and galactose on fructose absorption may be due to activation of the fructose carrier. Apple juice in particular contains fructose in excess of glucose and could lead to abdominal symptoms in susceptible children.

  11. Incomplete intestinal absorption of fructose.

    PubMed Central

    Kneepkens, C M; Vonk, R J; Fernandes, J

    1984-01-01

    Intestinal D-fructose absorption in 31 children was investigated using measurements of breath hydrogen. Twenty five children had no abdominal symptoms and six had functional bowel disorders. After ingestion of fructose (2 g/kg bodyweight), 22 children (71%) showed a breath hydrogen increase of more than 10 ppm over basal values, indicating incomplete absorption: the increase averaged 53 ppm, range 12 to 250 ppm. Four of these children experienced abdominal symptoms. Three of the six children with bowel disorders showed incomplete absorption. Seven children were tested again with an equal amount of glucose, and in three of them also of galactose, added to the fructose. The mean maximum breath hydrogen increases were 5 and 10 ppm, respectively, compared with 103 ppm after fructose alone. In one boy several tests were performed with various sugars; fructose was the only sugar incompletely absorbed, and the effect of glucose on fructose absorption was shown to be dependent on the amount added. It is concluded that children have a limited absorptive capacity for fructose. We speculate that the enhancing effect of glucose and galactose on fructose absorption may be due to activation of the fructose carrier. Apple juice in particular contains fructose in excess of glucose and could lead to abdominal symptoms in susceptible children. PMID:6476870

  12. Plasma absorption evidence via chirped pulse spectral transmission measurements

    SciTech Connect

    Jedrkiewicz, Ottavia; Minardi, Stefano; Couairon, Arnaud; Jukna, Vytautas; Selva, Marco; Di Trapani, Paolo

    2015-06-08

    This work aims at highlighting the plasma generation dynamics and absorption when a Bessel beam propagates in glass. We developed a simple diagnostics allowing us to retrieve clear indications of the formation of the plasma in the material, thanks to transmission measurements in the angular and wavelength domains. This technique featured by the use of a single chirped pulse having the role of pump and probe simultaneously leads to results showing the plasma nonlinear absorption effect on the trailing part of the pulse, thanks to the spectral-temporal correspondence in the measured signal, which is also confirmed by numerical simulations.

  13. Differential optical absorption spectrometer for measurement of tropospheric pollutants

    NASA Astrophysics Data System (ADS)

    Evangelisti, F.; Baroncelli, A.; Bonasoni, P.; Giovanelli, G.; Ravegnani, F.

    1995-05-01

    Our institute has recently developed a differential optical absorption spectrometry system called the gas analyzer spectrometer correlating optical absorption differences (GASCOAD), which features as a detector a linear image sensor that uses an artificial light source for long-path tropospheric-pollution monitoring. The GASCOAD, its method of eliminating interference from background sky light, and subsequent spectral analysis are reported and discussed. The spectrometer was used from 7 to 22 February 1993 in Milan, a heavily polluted metropolitan area, to measure the concentrations of SO2, NO2, O3, and HNO2 averaged over a 1.7-km horizontal light path. The findings are reported and briefly discussed.

  14. Modulation of ganciclovir intestinal absorption in presence of absorption enhancers.

    PubMed

    Shah, Pranav; Jogani, Viral; Mishra, Pushpa; Mishra, Anil Kumar; Bagchi, Tamishraha; Misra, Ambikanandan

    2007-10-01

    The purpose of this investigation was to study the influences of absorption enhancers in increasing oral bioavailability of Ganciclovir (GAN) by assessing the transepithelial permeation across cell monolayers in vitro and bioavailability in rats in vivo. The permeation of GAN across Caco-2 and MDCK cell monolayers in the absence/presence of dimethyl-beta-cyclodextrin (DMbetaCD), chitosan hydrochloride (CH), sodium lauryl sulphate (SLS), and their combinations was studied for a 2-h period. GAN was administered to rats in absence/presence of absorption enhancers and drug contents in plasma were estimated. We found that the apparent permeability coefficient (Papp) of GAN in absence of absorption enhancers (control) were 0.261 +/- 0.072 x 10(-6) and 0.486 +/- 0.063 x 10(-6) cm/s in Caco-2 and MDCK cell monolayers, respectively, whereas in the presence of DMbetaCD, CH, SLS, and their combinations, Papp of GAN increased by 5- to 25-fold and 7- to 33-fold as compared to control in Caco-2 and MDCK cell monolayers, respectively. However, in rats, the maximum enhancement in bioavailability of GAN during coadministration of these absorption enhancers was only fivefold compared to GAN control. To conclude, the absorption enhancers-DMbetaCD, CH, SLS, and their combinations demonstrated significant improvement in transepithelial permeation and bioavailability of GAN.

  15. Converting Sabine absorption coefficients to random incidence absorption coefficients.

    PubMed

    Jeong, Cheol-Ho

    2013-06-01

    Absorption coefficients measured by the chamber method are referred to as Sabine absorption coefficients, which sometimes exceed unity due to the finite size of a sample and non-uniform intensity in the reverberation chambers under test. In this study, conversion methods from Sabine absorption coefficients to random incidence absorption coefficients are proposed. The overestimations of the Sabine absorption coefficient are investigated theoretically based on Miki's model for porous absorbers backed by a rigid wall or an air cavity, resulting in conversion factors. Additionally, three optimizations are suggested: An optimization method for the surface impedances for locally reacting absorbers, the flow resistivity for extendedly reacting absorbers, and the flow resistance for fabrics. With four porous type absorbers, the conversion methods are validated. For absorbers backed by a rigid wall, the surface impedance optimization produces the best results, while the flow resistivity optimization also yields reasonable results. The flow resistivity and flow resistance optimization for extendedly reacting absorbers are also found to be successful. However, the theoretical conversion factors based on Miki's model do not guarantee reliable estimations, particularly at frequencies below 250 Hz and beyond 2500 Hz.

  16. An improved HPLC method overcoming Beer's law deviations arising from supramolecular interactions in tolfenamic acid and cyclodextrins complexes.

    PubMed

    Rozou, S; Antoniadou-Vyza, E

    1998-12-01

    Inclusion complexes of tolfenamic acid (TA), a non-steroidal anti-inflammatory drug, with methyl-beta cyclodextrin and hydroxypropyl-beta cyclodextrin were prepared and characterised. Spectrophotometric, chromatographic (RP-HPLC) and 1H NMR studies of the complexes were conducted. It was observed that cyclodextrins influence TA's molar absorptivity leading to Beer's law deviation. Consequently, the accuracy problem arose, urged for the application of specific chromatographic conditions for the determination of TA in the presence of CDs. A new HPLC method was developed and validated. TA was analysed on a C18 column 5 microm (150 x 4.6 mm), using a column thermostat regulated at 30 degrees C. The mobile phase consisted of methanol-phosphate buffer solution (pH 3.2; 0.07 M) (90:10 v/v) and the flow rate was set at 2.0 ml min(-1). The detector was operated at 286 nm. TA was successfully determined, overcoming the problems arising from the presence of cyclodextrins.

  17. Fat-soluble vitamin intestinal absorption: absorption sites in the intestine and interactions for absorption.

    PubMed

    Goncalves, Aurélie; Roi, Stéphanie; Nowicki, Marion; Dhaussy, Amélie; Huertas, Alain; Amiot, Marie-Josèphe; Reboul, Emmanuelle

    2015-04-01

    The interactions occurring at the intestinal level between the fat-soluble vitamins A, D, E and K (FSVs) are poorly documented. We first determined each FSV absorption profile along the duodenal-colonic axis of mouse intestine to clarify their respective absorption sites. We then investigated the interactions between FSVs during their uptake by Caco-2 cells. Our data show that vitamin A was mostly absorbed in the mouse proximal intestine, while vitamin D was absorbed in the median intestine, and vitamin E and K in the distal intestine. Significant competitive interactions for uptake were then elucidated among vitamin D, E and K, supporting the hypothesis of common absorption pathways. Vitamin A also significantly decreased the uptake of the other FSVs but, conversely, its uptake was not impaired by vitamins D and K and even promoted by vitamin E. These results should be taken into account, especially for supplement formulation, to optimise FSV absorption.

  18. Features of plastics edge cutting machining

    NASA Astrophysics Data System (ADS)

    Handozhko, A. V.; Shcherbakov, A. N.; Zaharov, L. A.; Gavrilenko, T. V.

    2016-04-01

    This article describes the features of pieces from thermoplastic materials in the form of electrical insulators cut by a disk edge tool. The problems in question are possible defects arising during machining and technological conditions that reduce their quantity. The necessity of required machining conditions matching substantiated in accordance with a specific grade of the material which is treated. Equipment and machining attachments, developed for experimental studies, determine the rational conditions of plastic electrical insulators machining. As a result of experiments the dependences of cut face quality parameters of plastics are obtained by machining conditions. The obtained results allowed us to make valid conclusions and recommendations.

  19. [A novel hyperspectra absorption enhancing method based on morphological top-hat transformation].

    PubMed

    Li, Hui; Lin, Qi-zhong; Wang, Qin-jun; Liu, Qing-jie; Chen, Yu

    2010-09-01

    Hyperspectral characteristics analysis of ground features is the basis for applications of high-resolution imaging technology to ground target identification and ground features classification. Based on morphological multi-scale Top-Hat transformation, a novel spectral absorption enhancing algorithms was put forward, which enhanced spectral absorption features while maintaining shape features of the absorption peak bands. Eleven reflectance spectra of different mineral groups were chosen from the mineral spectral library of the United States Geological Survey (USGS), and we used a K-means clustering analysis on both the absorption-enhanced spectra and the original reflectance spectra. Results showed that, firstly, clustering groups of the absorption-enhanced spectra (AES) had better similarity within the same clustering group, and greater difference between different groups, furthermore, they were more consistent with the geological background of these minerals compared with clustering result of the original spectra (OS). Secondly, while all the original spectra were re-sampled to their ASTER spectra and the AES clustering result was displayed in the form of ASTER spectra of the minerals, we could easily describe both the representative spectral feature of each clustering group, and the typical spectral differences between every two groups. These fully demonstrate that the absorption-enhanced spectra have enhanced absorption features of the mineral spectra, and improved the separability of hyper-spectra. Accordingly, feature analysis based on absorption enhanced spectra can be used as reference for information extracting based on multi-spectral remote sensing image data, and it is a very useful method of hyperspectral analysis. PMID:21105412

  20. Enhanced near-infrared absorption in graphene with multilayer metal-dielectric-metal nanostructure.

    PubMed

    Zhang, Lei; Tang, Linlong; Wei, Wei; Cheng, Xinlu; Wang, Wei; Zhang, Hong

    2016-09-01

    A multilayer metal-dielectric-metal nanostructure is proposed to enhance the absorption in graphene in a near-infrared region. The main feature of the structure is the generation of strong magnetic response within the dielectric spacer, which is directly related to absorption enhancement in graphene to over 22 times higher than that of free-standing monolayer graphene. We also show that absorption enhancement in graphene can be easily controlled by adjusting the geometry of the propose structure. The simple structural configuration and the flexible tunability in absorption enhancement are beneficial for practical fabrication and future applications in graphene-based active optoelectronic devices. PMID:27607608

  1. π-Extended "Earring" Porphyrins with Multiple Cavities and Near-Infrared Absorption.

    PubMed

    Rao, Yutao; Kim, Taeyeon; Park, Kyu Hyung; Peng, Fulei; Liu, Lei; Liu, Yunmei; Wen, Bin; Liu, Shubin; Kirk, Steven Robert; Wu, Licheng; Chen, Bo; Ma, Ming; Zhou, Mingbo; Yin, Bangshao; Zhang, Yuexing; Kim, Dongho; Song, Jianxin

    2016-05-23

    β,β-tripyrrin-bridged earring porphyrins were synthesized through Suzuki-Miyaura cross coupling reactions. These porphyrinoids have multiple cavities and can accommodate two or three metal ions per molecule. The structures of the porphyrins have been elucidated by x-ray diffraction analysis, and feature curved π planes. The electronic spectra of the porphyrins exhibit near-infrared (NIR) absorptions and metal insertion leads to red-shifted and intensified absorption features. Electrochemical analysis and transient absorption measurements indicated that the porphyrins exhibit effective electronic communication between their central and peripheral moieties. PMID:27038255

  2. Titan's Ammonia Feature

    NASA Technical Reports Server (NTRS)

    Smythe, W.; Nelson, R.; Boryta, M.; Choukroun, M.

    2011-01-01

    NH3 has long been considered an important component in the formation and evolution of the outer planet satellites. NH3 is particularly important for Titan, since it may serve as the reservoir for atmospheric nitrogen. A brightening seen on Titan starting in 2004 may arise from a transient low-lying fog or surface coating of ammonia. The spectral shape suggests the ammonia is anhydrous, a molecule that hydrates quickly in the presence of water.

  3. Diode laser absorption tomography using data compression techniques

    NASA Astrophysics Data System (ADS)

    Lindstrom, Chad; Tam, Chung-Jen; Givens, Ryan; Davis, Doug; Williams, Skip

    2008-02-01

    Tunable diode laser absorption spectroscopy (TDLAS) shows promise for in situ monitoring in high-speed flows. However, the dynamic nature of typical flows of supersonic combustors, gas turbine engines and augmenters can also lead to inhomogenities that cannot be captured by a single line-of-sight TDLAS measurement. Instead, multiple measurements varied over several spatial locations need to be made. In the current study, shock train structure in the isolator section of the Research Cell 18 supersonic combustion facility at Wright-Patterson AFB is measured. Although only two view angles are available for measurement, multiple absorption features along with a priori computational fluid dynamics (CFD) simulations enable estimates of two dimensional flow features to be formed. Vector quantization/kmeans data clustering is used to identify key flow features from the temporal history of the raw sinograms. Through the use of multiple absorption features that are measured nearly simultaneously, an approximate two-dimensional image can be formed. This image can be further refined through the use of an optimal set of basis functions that can be derived from a set of CFD simulations that describes the flow shapes.

  4. Adaptive feature extraction expert

    SciTech Connect

    Yuschik, M.

    1983-01-01

    The identification of discriminatory features places an upper bound on the recognition rate of any automatic speech recognition (ASR) system. One way to structure the extraction of features is to construct an expert system which applies a set of rules to identify particular properties of the speech patterns. However, these patterns vary for an individual speaker and from speaker to speaker so that another expert is actually needed to learn the new variations. The author investigates the problem by using sets of discriminatory features that are suggested by a feature generation expert, improves the selectivity of these features with a training expert, and finally develops a minimally spanning feature set with a statistical selection expert. 12 references.

  5. Absorption Enhancement in Organic–Inorganic Halide Perovskite Films with Embedded Plasmonic Gold Nanoparticles

    PubMed Central

    2015-01-01

    We report on the numerical analysis of solar absorption enhancement in organic–inorganic halide perovskite films embedding plasmonic gold nanoparticles. The effect of particle size and concentration is analyzed in realistic systems in which random particle location within the perovskite film and the eventual formation of dimers are also taken into account. We find a maximum integrated solar absorption enhancement of ∼10% in perovskite films of 200 nm thickness and ∼6% in 300 nm films, with spheres of radii 60 and 90 nm, respectively, in volume concentrations of around 10% in both cases. We show that the presence of dimers boosts the absorption enhancement up to ∼12% in the thinnest films considered. Absorption reinforcement arises from a double contribution of plasmonic near-field and scattering effects, whose respective weight can be discriminated and evaluated from the simulations. PMID:26500712

  6. [Analysis of UV-visible absorption spectrum on the decolorization of industrial wastewater by disinfection].

    PubMed

    Huang, Xin; Wang, Long-Yong; Gao, Nai-Yun; Li, Wei-Guo

    2012-10-01

    The UV-Visible absorption spectrum of industrial wastewater was explored to introduce a substituting method determining the color of water, and to compare the decolorization efficacy of different disinfectants. The results show that the visible absorption spectrum(350-600 nm), instead of ultraviolet absorption spectrum, should be applied to characterize the color of wastewater. There is a good correlation between the features of visible absorption spectrum and the true color of wastewater. Both ozone and chlorine dioxide has a better decolorization performance than chlorine. However, the color of chlorine dioxide itself has a negative effect on decolorization. The changes in the features of visible absorption spectrum effectively reflect the variations in the color of wastewater after disinfection.

  7. Small quantum absorption refrigerator with reversed couplings

    NASA Astrophysics Data System (ADS)

    Silva, Ralph; Skrzypczyk, Paul; Brunner, Nicolas

    2015-07-01

    Small quantum absorption refrigerators have recently attracted renewed attention. Here we present a missing design of a two-qubit fridge, the main feature of which is that one of the two machine qubits is itself maintained at a temperature colder than the cold bath. This is achieved by "reversing" the couplings to the baths compared to previous designs, where only a transition is maintained cold. We characterize the working regime and the efficiency of the fridge. We demonstrate the soundness of the model by deriving and solving a master equation. Finally, we discuss the performance of the fridge, in particular the heat current extracted from the cold bath. We show that our model performs comparably to the standard three-level quantum fridge and thus appears appealing for possible implementations of nanoscale thermal machines.

  8. Sound absorption in metallic foams

    NASA Astrophysics Data System (ADS)

    Lu, T. J.; Hess, Audrey; Ashby, M. F.

    1999-06-01

    The sound absorption capacity of one type of aluminum alloy foams—trade name Alporas—is studied experimentally. The foam in its as-received cast form contains closed porosities, and hence does not absorb sound well. To make the foam more transparent to air motion, techniques based on either rolling or hole drilling are used. Under rolling, the faces of some of the cells break to form small sharp-edged cracks as observed from a scanning electronic microscope. These cracks become passage ways for the in-and-out movement of air particles, resulting in sound absorption improvement. The best performance is nevertheless achieved via hole drilling where nearly all of the sound can be absorbed at selected frequencies. Combining rolling with hole drilling does not appear to lend additional benefits for sound absorption. Image analysis is carried out to characterize the changes in cell morphologies due to rolling/compression, and the drop in elastic modulus due to the formation of cracks is recorded. The effects of varying the relative foam density and panel thickness on sound absorption are measured, and optimal relative density and thickness of the panel are identified. Analytical models are used to explain the measured increase in sound absorption due to rolling and/or drilling. Sound absorbed by viscous flow across small cracks appears to dominate over that dissipated via other mechanisms.

  9. Influence of absorption on stability of terahertz difference frequency generation.

    PubMed

    Huang, Nan; Liu, Hongjun; Sun, Qibing; Wang, Zhaolu; Li, Shaopeng; Han, Jing

    2016-01-20

    This work presents numerical studies of the stability feature of terahertz difference frequency generation (THz-DFG) with a ZnGeP(2) crystal using two pump wavelengths. We found that the maximum output of a THz wave is located in the unstable output region because of the competitive equilibrium between the absorption and the gain. Furthermore, the output stability is dependent on the pump stability. Different from the results at the pump wavelength of 9.588 μm, there is neither an appropriate stable output region nor gain saturation region at the pump wavelength of 1.064 μm for a larger absorption coefficient. This work demonstrates that the stable output region of the THz wave is difficult to obtain when the pump absorption is excessively large in DFG. PMID:26835915

  10. A method for normalization of X-ray absorption spectra

    SciTech Connect

    Weng, T.-C.; Waldo, G.S.; Penner-Hahn, J.E.

    2010-07-20

    Accurate normalization of X-ray absorption data is essential for quantitative analysis of near-edge features. A method, implemented as the program MBACK, to normalize X-ray absorption data to tabulated mass absorption coefficients is described. Comparison of conventional normalization methods with MBACK demonstrates that the new normalization method is not sensitive to the shape of the background function, thus allowing accurate comparison of data collected in transmission mode with data collected using fluorescence ion chambers or solid-state fluorescence detectors. The new method is shown to have better reliability and consistency and smaller errors than conventional normalization methods. The sensitivity of the new normalization method is illustrated by analysis of data collected during an equilibrium titration.

  11. Excellent microwave absorption property of Graphene-coated Fe nanocomposites

    PubMed Central

    Zhao, Xingchen; Zhang, Zhengming; Wang, Liaoyu; Xi, Kai; Cao, Qingqi; Wang, Dunhui; Yang, Yi; Du, Youwei

    2013-01-01

    Graphene has evoked extensive interests for its abundant physical properties and potential applications. It is reported that the interfacial electronic interaction between metal and graphene would give rise to charge transfer and change the electronic properties of graphene, leading to some novel electrical and magnetic properties in metal-graphene heterostructure. In addition, large specific surface area, low density and high chemical stability make graphene act as an ideal coating material. Taking full advantage of the aforementioned features of graphene, we synthesized graphene-coated Fe nanocomposites for the first time and investigated their microwave absorption properties. Due to the charge transfer at Fe-graphene interface in Fe/G, the nanocomposites show distinct dielectric properties, which result in excellent microwave absorption performance in a wide frequency range. This work provides a novel approach for exploring high-performance microwave absorption material as well as expands the application field of graphene-based materials. PMID:24305606

  12. Cyclotron resonant scattering and absorption. [in gamma ray bursts

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.; Daugherty, Joseph K.

    1991-01-01

    The relativistic cross-sections for first-order absorption and second-order scattering are compared to determine the conditions under which the absorption cross-section is a good approximation to the much more complex scattering cross-section for purposes of modeling cyclotron lines in gamma-ray bursts. Differences in both the cross-sections and the line profiles are presented for a range of field strengths, angles, and electron temperatures. The relative difference of the cross-sections at one line width from resonance was found to increase with field strength and harmonic number. The difference is also strongly dependent on the photon angle to the magnetic field. For the field strength, 1.7 x 10 to the 12th G, and the angle inferred from the Ginga burst features, absorption is an excellent approximation for the profiles at the first and second harmonics.

  13. Osteochondromas in fibrodysplasia ossificans progressiva: a widespread trait with a streaking but overlooked appearance when arising at femoral bone end.

    PubMed

    Morales-Piga, A; Bachiller-Corral, J; González-Herranz, P; Medrano-SanIldelfonso, M; Olmedo-Garzón, J; Sánchez-Duffhues, G

    2015-10-01

    Metaphyseal bony outgrowths are a well-recognized feature of fibrodysplasia ossificans progressiva (FOP) phenotype, but its genuine frequency, topographic distribution, morphological aspect, and potential implications are not fully established. To better ascertain the frequency and characteristics of osteocartilaginous exostoses in FOP disease, we conducted a cross-sectional radiological study based on all the traceable cases identified in a previous comprehensive national research. Metaphyseal exostoses were present in all the 17 cases of FOP studied. Although most often arising from the distal femoral (where metaphyseal exostoses adopt a peculiar not yet reported appearance) and proximal tibial bones, we have found that they are not restricted to these areas, but rather can be seen scattered at a variety of other skeletal sites. Using nuclear magnetic resonance imaging, we show that these exophytic outgrowths are true osteochondromas. As a whole, these results are in agreement with data coming from the literature review. Our study confirms the presence of metaphyseal osteochondromas as a very frequent trait of FOP phenotype and an outstanding feature of its anomalous skeletal developmental component. In line with recent evidences, this might imply that dysregulation of BMP signaling, in addition to promoting exuberant heterotopic ossification, could induce aberrant chondrogenesis and osteochondroma formation. Unveiling the molecular links between these physiopathological pathways could help to illuminate the mechanisms that govern bone morphogenesis. PMID:26049728

  14. Osteochondromas in fibrodysplasia ossificans progressiva: a widespread trait with a streaking but overlooked appearance when arising at femoral bone end.

    PubMed

    Morales-Piga, A; Bachiller-Corral, J; González-Herranz, P; Medrano-SanIldelfonso, M; Olmedo-Garzón, J; Sánchez-Duffhues, G

    2015-10-01

    Metaphyseal bony outgrowths are a well-recognized feature of fibrodysplasia ossificans progressiva (FOP) phenotype, but its genuine frequency, topographic distribution, morphological aspect, and potential implications are not fully established. To better ascertain the frequency and characteristics of osteocartilaginous exostoses in FOP disease, we conducted a cross-sectional radiological study based on all the traceable cases identified in a previous comprehensive national research. Metaphyseal exostoses were present in all the 17 cases of FOP studied. Although most often arising from the distal femoral (where metaphyseal exostoses adopt a peculiar not yet reported appearance) and proximal tibial bones, we have found that they are not restricted to these areas, but rather can be seen scattered at a variety of other skeletal sites. Using nuclear magnetic resonance imaging, we show that these exophytic outgrowths are true osteochondromas. As a whole, these results are in agreement with data coming from the literature review. Our study confirms the presence of metaphyseal osteochondromas as a very frequent trait of FOP phenotype and an outstanding feature of its anomalous skeletal developmental component. In line with recent evidences, this might imply that dysregulation of BMP signaling, in addition to promoting exuberant heterotopic ossification, could induce aberrant chondrogenesis and osteochondroma formation. Unveiling the molecular links between these physiopathological pathways could help to illuminate the mechanisms that govern bone morphogenesis.

  15. The origin of the excess transit absorption in the HD 189733 system: planet or star?

    NASA Astrophysics Data System (ADS)

    Barnes, J. R.; Haswell, C. A.; Staab, D.; Anglada-Escudé, G.

    2016-10-01

    We have detected excess absorption in the emission cores of Ca II H&K during transits of HD 189733b for the first time. Using observations of three transits, we investigate the origin of the absorption, which is also seen in Hα and the Na I D lines. Applying differential spectrophotometry methods to the Ca II H and Ca II K lines combined, using respective passband widths of Δλ = 0.4 and 0.6 Å yields excess absorption of td = 0.0074 ± 0.0044 (1.7σ; Transit 1) and 0.0214 ± 0.0022 (9.8σ; Transit 2). Similarly, we detect excess Hα absorption in a passband of width Δλ = 0.7 Å, with td = 0.0084 ± 0.0016 (5.2σ) and 0.0121 ± 0.0012 (9.9σ). For both lines, Transit 2 is thus significantly deeper. Combining all three transits for the Na I D lines yields excess absorption of td = 0.0041 ± 0.0006 (6.5σ). By considering the time series observations of each line, we find that the excess apparent absorption is best recovered in the stellar reference frame. These findings lead us to postulate that the main contribution to the excess transit absorption in the differential light curves arises because the normalizing continuum bands form in the photosphere, whereas the line cores contain a chromospheric component. We cannot rule out that part of the excess absorption signature arises from the planetary atmosphere, but we present evidence which casts doubt on recent claims to have detected wind motions in the planet's atmosphere in these data.

  16. The detection of a broad interstellar extinction feature near 1700 A

    NASA Technical Reports Server (NTRS)

    Carnochan, David J.

    1989-01-01

    A statistical examination of 126 extinction curves has revealed the presence of a second broad absorption feature similar in nature to the 2200 A feature. The feature is centered on wavelength 1706 A, has a full half-width of 350 A, and a mean central height of 0.21 magnitudes. The strength of the feature increases with E(B-V) supporting an interstellar origin, and on average it is 18 times weaker than the 2200 A feature.

  17. Probing electrons in TiO2 polaronic trap states by IR-absorption: Evidence for the existence of hydrogenic states

    PubMed Central

    Sezen, Hikmet; Buchholz, Maria; Nefedov, Alexei; Natzeck, Carsten; Heissler, Stefan; Di Valentin, Cristiana; Wöll, Christof

    2014-01-01

    An important step in oxide photochemistry, the loading of electrons into shallow trap states, was studied using infrared (IR) spectroscopy on both, rutile TiO2 powders and single-crystal, r-TiO2(110) oriented samples. After UV-irradiation or n-doping by exposure to H-atoms broad IR absorption lines are observed for the powders at around 940 cm−1. For the single crystal substrates, the IR absorption bands arising from an excitation of the trapped electrons into higher-lying final states show additional features not observed in previous work. On the basis of our new, high-resolution data and theoretical studies on the polaron binding energy in rutile we propose that the trap states correspond to polarons and are thus intrinsic in nature. We assign the final states probed by the IR-experiments to hydrogenic states within the polaron potential. Implications of these observations for photochemistry on oxides will be briefly discussed. PMID:24448350

  18. Adenocarcinoma arising from heterotopic pancreas at the third portion of the duodenum.

    PubMed

    Fukino, Nobutada; Oida, Takatsugu; Mimatsu, Kenji; Kuboi, Youichi; Kida, Kazutoshi

    2015-04-01

    A 62-year-old Japanese man presented to our hospital with a history of weight loss of 6 kg in 4 mo. Imaging examinations revealed a tumor located on the third portion of the duodenum with stenosis. We suspected duodenal carcinoma and performed pancreas-preserving segmental duodenectomy. Adenocarcinoma arising from a heterotopic pancreas at the third portion of the duodenum was finally diagnosed by immunohistochemical staining. Malignant transformation in the duodenum arising from a heterotopic pancreas is extremely rare; to our knowledge, only 13 cases have been reported worldwide, including the present case. The most common location of malignancy is the proximal duodenum at the first and descending portion. Herein, we describe the first case of adenocarcinoma arising from a heterotopic pancreas, which was located in the third portion of the duodenum, with a review of the literature.

  19. Osteosarcoma arising from a haemangioma: case report and review of the literature.

    PubMed

    Mallınson, Paul; Coupal, Tyler; Hayes, Malcolm; Clarkson, Paul; Munk, Peter; Ouellette, Hugue

    2014-01-01

    To create awareness of the benign lesions from which osteosarcoma may arise. Osteosarcoma is a rare tumour of bone the etiology of which is poorly understood, but it may arise from benign lesions. Malignant transformation in hemangiomas, in the absence of prior radiation, is exceedingly rare and the resulting neoplasm is usually an angiosarcoma. We report the case of a 30-year-old woman where investigation for thigh pain revealed a distal femoral hemangioma. She represented with pain and mass 18 years later, leading to a confirmed diagnosis of osteosarcoma at the same site. Osteosarcomas may arise from a variety of benign lesions. In this article we report the case of a histologically confirmed hemangioma which subsequently underwent malignant change into an osteosarcoma.

  20. Basal Cell Carcinoma and Syringocystadenoma Papilliferum Arising in Nevus Sebaceous on Face—A Rare Entity

    PubMed Central

    Gupta, Sunil Kumar; Gupta, Vivek

    2015-01-01

    Nevus sebaceus of Jadassohn is a congenital cutaneous hamartoma comprising of multiple skin structures. It has the potential to develop into variety of neoplasms of various epidermal adnexal origins. While multiple tumors may occasionally arise, it is unusual to develop two different types of tumor, benign and malignant, to arise simultaneously within a single sebaceus nevus. Here in, we report a case of a 27-year-old male with two neoplastic proliferations including a syringocystadenoma papilliferum a benign tumor and basal cell carcinoma a malignant tumor arising in a long-standing nevus sebaceus on the face. Neoplastic changes are common in nevus sebaceous present on scalp but our case is unique due to the presence of two different types of neoplasm in a nevus sebaceous which was present on face. PMID:26677302

  1. Adenocarcinoma arising from heterotopic pancreas at the third portion of the duodenum

    PubMed Central

    Fukino, Nobutada; Oida, Takatsugu; Mimatsu, Kenji; Kuboi, Youichi; Kida, Kazutoshi

    2015-01-01

    A 62-year-old Japanese man presented to our hospital with a history of weight loss of 6 kg in 4 mo. Imaging examinations revealed a tumor located on the third portion of the duodenum with stenosis. We suspected duodenal carcinoma and performed pancreas-preserving segmental duodenectomy. Adenocarcinoma arising from a heterotopic pancreas at the third portion of the duodenum was finally diagnosed by immunohistochemical staining. Malignant transformation in the duodenum arising from a heterotopic pancreas is extremely rare; to our knowledge, only 13 cases have been reported worldwide, including the present case. The most common location of malignancy is the proximal duodenum at the first and descending portion. Herein, we describe the first case of adenocarcinoma arising from a heterotopic pancreas, which was located in the third portion of the duodenum, with a review of the literature. PMID:25852297

  2. Dermatofibrosarcoma protuberans arising at a Rho(D) immune globulin injection site.

    PubMed

    Hirano, Stefanie A; Torosky, Cyndi M

    2012-11-01

    Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue tumor arising in the dermis. It is notorious for high rates of local recurrence despite its low metastatic potential. Although the etiology is unknown, DFSP often is considered to arise within scars and at sites of prior vaccination or trauma. Clinically, DFSP can be highly variable and mimic other soft tissue proliferations. We present a case of recurrent DFSP arising at the site of a Rho(D) immune globulin (Rhlg) injection that was administered 7 years prior. We also discuss the diagnostic challenges of DFSP as well as the indolent and locally recurrent nature of the tumor. This case serves to remind dermatologists of the highly variable clinical appearance of DFSP as well as to warn against presumptive diagnoses of lesions that mimic keloids and hypertrophic scars.

  3. Cutaneous horn arising from an area of discoid lupus erythematosus on the scalp.

    PubMed

    Fatani, Mohammad Ibrahim; Hussain, Waleed Mohd; Baltow, Badee; Alsharif, Sahar

    2014-04-03

    A cutaneous horn is a rare clinical condition characterised by a conical projection of hyperkeratotic epidermis. Cutaneous horns most commonly arise from sun-exposed skin in elderly men, but may arise from any part of the body at any age in men and women. When a cutaneous horn forms, it is important to determine the underlying cause. Various skin diseases may present with cutaneous horns including viral warts, actinic keratosis, keratoacanthoma, seborrhoeic keratosis, pyogenic granuloma, discoid lupus erythematosus, verruca vulgaris, Bowen's disease, basal cell carcinoma and squamous cell carcinoma. The underlying pathology is benign in 61.1% of cases, premalignant in 23.2% of cases and malignant in 15.7% of cases. We report a patient with a cutaneous horn arising from an area of discoid lupus erythematosus on the scalp.

  4. Imaging features of spinal tanycytic ependymoma.

    PubMed

    Tomek, Michal; Jayajothi, Anandapadmanabhan; Brandner, Sebastian; Jaunmuktane, Zane; Lee, Cheong Hung; Davagnanam, Indran

    2016-02-01

    Tanycytic ependymoma is an unusual morphological variant of WHO grade II ependymoma, typically arising from the cervical or thoracic spinal cord. Although the literature deals extensively with pathological features of this tumour entity, imaging features have not been well characterised. The purpose of this study was to review magnetic resonance imaging (MRI) features of spinal tanycytic ependymomas reported in the literature to date, exemplified by a case of a patient with tanycytic ependymoma of the conus medullaris presenting to our hospital. A Medline search of the English literature for all previously published cases of spinal tanycytic ependymoma was carried out and the reported MRI features reviewed. The tumours were found to be typically well-demarcated masses, predominantly showing isointensity on T1-weighted signal, and T2-weighted hyperintensity, with variable patterns of contrast enhancement. A cystic component was seen in half of the cases, and in a minority a mural nodule was present within the cyst wall. Associated syrinx formation was observed in one-third of the cases and haemorrhage was rare, which may be helpful pointers in differentiating the lesion from other ependymoma subtypes. In conclusion, MRI characteristics of spinal tanycytic ependymoma are variable and non-specific, and radiological diagnosis thus remains challenging, although certain predominant features are identified in this report. Knowledge of these is important in the diagnostic differentiation from other intramedullary and extramedullary spinal tumours in order to guide appropriate surgical management. PMID:26755489

  5. Absorption-heat-pump system

    DOEpatents

    Grossman, G.; Perez-Blanco, H.

    1983-06-16

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  6. Diabetic lipohypertrophy delays insulin absorption.

    PubMed

    Young, R J; Hannan, W J; Frier, B M; Steel, J M; Duncan, L J

    1984-01-01

    The effect of lipohypertrophy at injection sites on insulin absorption has been studied in 12 insulin-dependent diabetic patients. The clearance of 125I-insulin from sites with lipohypertrophy was significantly slower than from complementary nonhypertrophied sites (% clearance in 3 h, 43.8 +/- 3.5 +/- SEM) control; 35.3 +/- 3.9 lipohypertrophy, P less than 0.05). The degree of the effect was variable but sufficient in several patients to be of clinical importance. Injection-site lipohypertrophy is another factor that modifies the absorption of subcutaneously injected insulin.

  7. Solar powered absorption air conditioning

    NASA Astrophysics Data System (ADS)

    Vardon, J. M.

    1980-04-01

    Artificial means of providing or removing heat from the building are discussed along with the problem of the appropriate building design and construction for a suitable heat climate inside the building. The use of a lithium bromide-water absorption chiller, powered by a hot water store heated by an array of stationary flat collectors, is analyzed. An iterative method of predicting the cooling output from a LiBr-water absorption refrigeration plant having variable heat input is described and a model allowing investigation of the performance of a solar collector and thermal storage system is developed.

  8. Feature mixing rather than feature replacement during perceptual filling-in.

    PubMed

    Hsieh, P-J; Tse, P U

    2009-02-01

    'Filling-in' occurs when a retinally stabilized object subjectively appears to vanish following perceptual fading of its boundaries. The term 'filling-in' literally means that information about the apparently vanished object is lost and replaced solely by information arising from the surrounding background. However, we find evidence that the mechanism of 'filling-in' can actually involve a process of 'feature mixing' rather than 'feature replacement,' whereby features on either side of a perceptually faded boundary merge. Here we investigate the properties of feature mixing and specify certain conditions under which such mixing occurs. Our results show that, when using visual stimuli composed of spatially alternating stripes containing different luminances or motion signals, and when using the neon-color-spreading paradigm, the filled-in luminance, motion, or color is approximately the area and magnitude weighted average of the background and the foreground luminance, motion, or color, respectively. Together, these results demonstrate that, under at least certain conditions, 'filling-in' may involve a process of feature mixing or feature averaging rather than one of feature replacement. PMID:19135078

  9. Transient absorption spectroscopy of laser shocked explosives

    SciTech Connect

    Mcgrane, Shawn D; Dang, Nhan C; Whitley, Von H; Bolome, Cindy A; Moore, D S

    2010-01-01

    Transient absorption spectra from 390-890 nm of laser shocked RDX, PETN, sapphire, and polyvinylnitrate (PVN) at sub-nanosecond time scales are reported. RDX shows a nearly linear increase in absorption with time after shock at {approx}23 GPa. PETN is similar, but with smaller total absorption. A broad visible absorption in sapphire begins nearly immediately upon shock loading but does not build over time. PVN exhibits thin film interference in the absorption spectra along with increased absorption with time. The absorptions in RDX and PETN are suggested to originate in chemical reactions happening on picosecond time scales at these shock stresses, although further diagnostics are required to prove this interpretation.

  10. Osteochondroma arising from a lumbar facet joint in a 16-year-old.

    PubMed

    Hancock, Graeme E; Mariathas, Chrishan; Fernandes, James A; Breakwell, Lee M; Cole, Ashley A; Michael, Antony L R

    2015-05-01

    Osteochondromas are benign tumours of bony or cartilaginous origin, which may be solitary or multiple. They are rare in the axial skeleton and have previously been reported to arise from facet joints only in four cases in the English literature. We report the case of a 16-year-old girl who presented with a palpable bony lump and a short history of back pain. Imaging showed a bony lesion arising from a left-sided facet joint in the lumbar spine. Following excision biopsy, there was complete resolution of symptoms. The literature on the origin and management of spinal osteochondromas is discussed.

  11. Solitary fibrous tumor arising in the mons pubis: a case report.

    PubMed

    Lee, D H

    2016-01-01

    Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms of fibroblastic origin that mainly arise from the pleura. Although SFTs arising at numerous extrapleural locations have been reported, extrapleural soft tissue SFTs are extremely rare. The diagnosis of SFTs is based on histologic findings. However, given the histological variability of SFTs, immunohistochemical examination becomes important in their diagnosis. Complete surgical resection is the only and a very important prognostic factor and is recommended for the treatment of both benign and malignant SFTs with a curative intent. Here, the author reports what he believes to be the first case of an SFT originating in the mons pubis.

  12. Solitary fibrous tumor arising in the mons pubis: a case report.

    PubMed

    Lee, D H

    2016-01-01

    Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms of fibroblastic origin that mainly arise from the pleura. Although SFTs arising at numerous extrapleural locations have been reported, extrapleural soft tissue SFTs are extremely rare. The diagnosis of SFTs is based on histologic findings. However, given the histological variability of SFTs, immunohistochemical examination becomes important in their diagnosis. Complete surgical resection is the only and a very important prognostic factor and is recommended for the treatment of both benign and malignant SFTs with a curative intent. Here, the author reports what he believes to be the first case of an SFT originating in the mons pubis. PMID:27352579

  13. Mixed tumor of the vulva: a report of two cases probably arising in Bartholin's gland.

    PubMed

    Ordóñez, N G; Manning, J T; Luna, M A

    1981-07-01

    A case of benign mixed tumor of the vulva and a case of carcinoma arising in a similar benign mixed tumor of the vulva are reported. Both mixed tumors were of salivary gland type and probably arose in the Bartholin's gland. Only three previous cases of benign mixed tumor of the vulva have been documented in the literature. Two arose in the vestibular glands, and the third arose in cutaneous sweat glands. No case of carcinoma arising in a benign mixed tumor of the vulva has been previously documented.

  14. Optical absorption and luminescence studies of fast neutron-irradiated complex oxides for jewellery applications

    NASA Astrophysics Data System (ADS)

    Mironova-Ulmane, N.; Skvortsova, V.; Popov, A. I.

    2016-07-01

    We studied the optical absorption and luminescence of agate (SiO2), topaz (Al2[SiO4](F,OH)2), beryl (Be3Al2Si6O18), and prehnite (Ca2Al(AlSi3O10)(OH)2) doped with different concentrations of transition metal ions and exposed to fast neutron irradiation. The exchange interaction between the impurity ions and the defects arising under neutron irradiation causes additional absorption as well as bands' broadening in the crystals. These experimental results allow us to suggest the method for obtaining new radiation-defect induced jewellery colors of minerals due to neutron irradiation.

  15. Defeating feature fatigue.

    PubMed

    Rust, Roland T; Thompson, Debora Viana; Hamilton, Rebecca W

    2006-02-01

    Consider a coffeemaker that offers 12 drink options, a car with more than 700 features on the dashboard, and a mouse pad that's also a clock, calculator, and FM radio. All are examples of "feature bloat", or "featuritis", the result of an almost irresistible temptation to load products with lots of bells and whistles. The problem is that the more features a product boasts, the harder it is to use. Manufacturers that increase a product's capability--the number of useful functions it can perform--at the expense of its usability are exposing their customers to feature fatigue. The authors have conducted three studies to gain a better understanding of how consumers weigh a product's capability relative to its usability. They found that even though consumers know that products with more features are harder to use, they initially choose high-feature models. They also pile on more features when given the chance to customize a product for their needs. Once consumers have actually worked with a product, however, usability starts to matter more to them than capability. For managers in consumer products companies, these findings present a dilemma: Should they maximize initial sales by designing high-feature models, which consumers consistently choose, or should they limit the number of features in order to enhance the lifetime value of their customers? The authors' analytical model guides companies toward a happy middle ground: maximizing the net present value of the typical customer's profit stream. The authors also advise companies to build simpler products, help consumers learn which products suit their needs, develop products that do one thing very well, and design market research in which consumers use actual products or prototypes.

  16. Aerosol Absorption Measurements in MILAGRO.

    NASA Astrophysics Data System (ADS)

    Gaffney, J. S.; Marley, N. A.; Arnott, W. P.; Paredes-Miranda, L.; Barnard, J. C.

    2007-12-01

    During the month of March 2006, a number of instruments were used to determine the absorption characteristics of aerosols found in the Mexico City Megacity and nearby Valley of Mexico. These measurements were taken as part of the Department of Energy's Megacity Aerosol Experiment - Mexico City (MAX-Mex) that was carried out in collaboration with the Megacity Interactions: Local and Global Research Observations (MILAGRO) campaign. MILAGRO was a joint effort between the DOE, NSF, NASA, and Mexican agencies aimed at understanding the impacts of a megacity on the urban and regional scale. A super-site was operated at the Instituto Mexicano de Petroleo in Mexico City (designated T-0) and at the Universidad Technologica de Tecamac (designated T-1) that was located about 35 km to the north east of the T-0 site in the State of Mexico. A third site was located at a private rancho in the State of Hidalgo approximately another 35 km to the northeast (designated T-2). Aerosol absorption measurements were taken in real time using a number of instruments at the T-0 and T-1 sites. These included a seven wavelength aethalometer, a multi-angle absorption photometer (MAAP), and a photo-acoustic spectrometer. Aerosol absorption was also derived from spectral radiometers including a multi-filter rotating band spectral radiometer (MFRSR). The results clearly indicate that there is significant aerosol absorption by the aerosols in the Mexico City megacity region. The absorption can lead to single scattering albedo reduction leading to values below 0.5 under some circumstances. The absorption is also found to deviate from that expected for a "well-behaved" soot anticipated from diesel engine emissions, i.e. from a simple 1/lambda wavelength dependence for absorption. Indeed, enhanced absorption is seen in the region of 300-450 nm in many cases, particularly in the afternoon periods indicating that secondary organic aerosols are contributing to the aerosol absorption. This is likely due

  17. Sizeable red-shift of absorption and fluorescence of subporphyrazine induced by peripheral push and pull substitution.

    PubMed

    Liang, Xu; Shimizu, Soji; Kobayashi, Nagao

    2014-11-18

    Peripheral substitution with electron-donating (push) and electron-withdrawing (pull) substituents caused a sizeable red-shift of the Q band absorption and fluorescence of subporphyrazine, and the red-shift was controlled by the push substituents. Control of the chromophore symmetry and inherent molecular chirality arising from the pattern of substitution were also investigated.

  18. Time Varying Feature Data

    NASA Astrophysics Data System (ADS)

    Echterhoff, J.; Simonis, I.; Atkinson, R.

    2012-04-01

    The infrastructure to gather, store and access information about our environment is improving and growing rapidly. The increasing amount of information allows us to get a better understanding of the current state of our environment, historical processes and to simulate and predict the future state of the environment. Finer grained spatial and temporal data and more reliable communications make it easier to model dynamic states and ephemeral features. The exchange of information within and across geospatial domains is facilitated through the use of harmonized information models. The Observations & Measurements (O&M) developed through OGC and standardised by ISO is an example of such a cross-domain information model. It is used in many domains, including meteorology, hydrology as well as the emergency management. O&M enables harmonized representation of common metadata that belong to the act of determining the state of a feature property, whether by sensors, simulations or humans. In addition to the resulting feature property value, information such as the result quality but especially the time that the result applies to the feature property can be represented. Temporal metadata is critical to modelling past and future states of a feature. The features, and the semantics of each property, are defined in domain specific Application Schema using the General Feature Model (GFM) from ISO 19109 and usually encoded following ISO 19136. However, at the moment these standards provide only limited support for the representation and handling of time varying feature data. Features like rivers, wildfires or gas plumes have a defined state - for example geographic extent - at any given point in time. To keep track of changes, a more complex model for example using time-series coverages is required. Furthermore, the representation and management of feature property value changes via the service interfaces defined by OGC and ISO - namely: WFS and WCS - would be rather complex

  19. Label free detection of phospholipids by infrared absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Ahmed, Tahsin; Foster, Erick; Vigil, Genevieve; Khan, Aamir A.; Bohn, Paul; Howard, Scott S.

    2014-08-01

    We present our study on compact, label-free dissolved lipid sensing by combining capillary electrophoresis separation in a PDMS microfluidic chip online with mid-infrared (MIR) absorption spectroscopy for biomarker detection. On-chip capillary electrophoresis is used to separate the biomarkers without introducing any extrinsic contrast agent, which reduces both cost and complexity. The label free biomarker detection could be done by interrogating separated biomarkers in the channel by MIR absorption spectroscopy. Phospholipids biomarkers of degenerative neurological, kidney, and bone diseases are detectable using this label free technique. These phospholipids exhibit strong absorption resonances in the MIR and are present in biofluids including urine, blood plasma, and cerebrospinal fluid. MIR spectroscopy of a 12-carbon chain phosphatidic acid (PA) (1,2-dilauroyl-snglycero- 3-phosphate (sodium salt)) dissolved in N-methylformamide, exhibits a strong amide peak near wavenumber 1660 cm-1 (wavelength 6 μm), arising from the phosphate headgroup vibrations within a low-loss window of the solvent. PA has a similar structure to many important phospholipids molecules like phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and phosphatidylserine (PS), making it an ideal molecule for initial proof-of-concept studies. This newly proposed detection technique can lead us to minimal sample preparation and is capable of identifying several biomarkers from the same sample simultaneously.

  20. Absorption Mode FT-ICR Mass Spectrometry Imaging

    SciTech Connect

    Smith, Donald F.; Kilgour, David P.; Konijnenburg, Marco; O'Connor, Peter B.; Heeren, Ronald M.

    2013-12-03

    Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power for molecular imaging experiments. This high mass resolving power ensures that closely spaced peaks at the same nominal mass are resolved for proper image generation. Typically higher magnetic fields are used to increase mass resolving power. However, a gain in mass resolving power can also be realized by phase correction of the data for absorption mode display. In addition to mass resolving power, absorption mode offers higher mass accuracy and signal-to-noise ratio over the conventional magnitude mode. Here we present the first use of absorption mode for Fourier transform ion cyclotron resonance mass spectrometry imaging. The Autophaser algorithm is used to phase correct each spectrum (pixel) in the image and then these parameters are used by the Chameleon work-flow based data processing software to generate absorption mode ?Datacubes? for image and spectral viewing. Absorption mode reveals new mass and spatial features that are not resolved in magnitude mode and results in improved selected ion image contrast.

  1. Concentration-modulated absorption spectroscopy.

    PubMed

    Langley, A J; Beaman, R A; Baran, J; Davies, A N; Jones, W J

    1985-07-01

    Concentration modulation is demonstrated to be a technique capable of markedly extending sensitivity limits in absorption spectroscopy. The gain generated relates in such a manner to sample transmittance that for the first reported time direct spectroscopic concentration measurements become possible. When concentration modulation is used with picosecond lasers, state lifetimes can be determined to a limit of approximately 20 psec.

  2. Ultraviolet and Light Absorption Spectrometry.

    ERIC Educational Resources Information Center

    Hargis, L. G.; Howell, J. A.

    1984-01-01

    Reviews developments in ultraviolet and light absorption spectrometry from December 1981 through November 1983, focusing on the chemistry involved in developing suitable reagents, absorbing systems, and methods of determination, and on physical aspects of the procedures. Includes lists of spectrophotometric methods for metals, non-metals, and…

  3. Migrant labor absorption in Malaysia.

    PubMed

    Nayagam, J

    1992-01-01

    The use of migrant workers to ease labor shortages caused by rapid industrialization in Malaysia during the twentieth century is examined. "This paper will focus on: (1) the extent, composition and distribution of migrant workers; (2) the labor shortage and absorption of migrant workers; and (3) the role of migrant workers in the government's economic restructuring process."

  4. Migrant labor absorption in Malaysia.

    PubMed

    Nayagam, J

    1992-01-01

    The use of migrant workers to ease labor shortages caused by rapid industrialization in Malaysia during the twentieth century is examined. "This paper will focus on: (1) the extent, composition and distribution of migrant workers; (2) the labor shortage and absorption of migrant workers; and (3) the role of migrant workers in the government's economic restructuring process." PMID:12285766

  5. Phenoxyethanol absorption by polyvinyl chloride.

    PubMed

    Lee, M G

    1984-12-01

    Phenoxyethanol was found to be absorbed by polyvinyl chloride administration sets during continuous irrigation therapy. Depending upon the conditions of administration up to 20% loss of potency could occur. Absorption of the drug by the rigid plastic luer-lock fitting of the set caused softening and decreased rigidity of the plastic.

  6. Upper limits for absorption by water vapor in the near-UV

    NASA Astrophysics Data System (ADS)

    Wilson, Eoin M.; Wenger, John C.; Venables, Dean S.

    2016-02-01

    There are few experimental measurements of absorption by water vapor in the near-UV. Here we report the results of spectral measurements of water vapor absorption at ambient temperature and pressure from 325 nm to 420 nm, covering most tropospherically relevant short wavelengths. Spectra were recorded using a broadband optical cavity in the chemically controlled environment of an atmospheric simulation chamber. No absorption attributable to the water monomer (or the dimer) was observed at the 0.5 nm resolution of our system. Our results are consistent with calculated spectra and recent DOAS field observations, but contradict a report of significant water absorption in the near-UV. Based on the detection limit of our instrument, we report upper limits for the water absorption cross section of less than 5×10-26 cm2 molecule-1 at our instrument resolution. For a typical, indicative slant column density of 4×1023 cm2, we calculate a maximum optical depth of 0.02 arising from absorption of water vapor in the atmosphere at wavelengths between 340 nm and 420 nm, with slightly higher maximum optical depths below 340 nm. The results of this work, together with recent atmospheric observations and computational results, suggest that water vapor absorption across most of the near-UV is small compared to visible and infrared wavelengths.

  7. New features in MEDM.

    SciTech Connect

    Evans, K., Jr.

    1999-04-13

    MEDM, which is derived from Motif Editor and Display Manager, is the primary graphical interface to the EPICS control system. This paper describes new features that have been added to MEDM in the last two years. These features include new editing capabilities, a PV Info dialog box, a means of specifying limits and precision, a new implementation of the Cartesian Plot, new features for several objects, new capability for the Related Display, help, a user-configurable Execute Menu, reconfigured start-up options, and availability for Windows 95/98/NT. Over one hundred bugs have been fixed, and the program is quite stable and in extensive use.

  8. Cellular neurothekeomas arising on a café-au-lait macule.

    PubMed

    Hernández-Martín, Angela; Colmenero, Isabel; Torrelo, Antonio

    2011-01-01

    Neurothekeoma is a tumor probably derived from the nerve sheath, which usually appears during the first 2 decades of life as a solitary papule or nodule; multiple neurothekeomas are very unusual. We present a case of multiple cellular neurothekeomas arising on a café-au-lait macule in a child, a situation that has not been reported to our knowledge.

  9. Exploring Ethical Dilemmas for Principals Arising from Role Conflict with School Counsellors

    ERIC Educational Resources Information Center

    Kimber, Megan; Campbell, Marilyn

    2014-01-01

    Acting in the best interests of students is central to the moral and ethical work of schools. Yet tensions can arise between principals and school counsellors as they work from at times opposing professional paradigms. In this article we report on principals' and counsellors' responses to scenarios covering confidentiality and the law,…

  10. Cyst of the gastric wall arising from heterotopic pancreas: report of a case.

    PubMed

    Cecchini, Stefano; Marchesi, Federico; Caruana, Pietro; Tartamella, Francesco; Mita, Maria Teresa; Rubichi, Francesco; Roncoroni, Luigi

    2016-01-01

    Heterotopia of pancreatic tissue is a common developmental anomaly, affecting predominantly the gastrointestinal tract. The case of a symptomatic cyst arising from the posterior gastric wall in a 40-year-old man is presented, undergoing laparoscopic gastric wedge resection. Pathology report described a cyst of the gastric wall lined by ductal pancreatic epithelium. PMID:27649007

  11. One-Dimensional Infinite Horizon Nonconcave Optimal Control Problems Arising in Economic Dynamics

    SciTech Connect

    Zaslavski, Alexander J.

    2011-12-15

    We study the existence of optimal solutions for a class of infinite horizon nonconvex autonomous discrete-time optimal control problems. This class contains optimal control problems without discounting arising in economic dynamics which describe a model with a nonconcave utility function.

  12. Saliva DHEAS Changes in Patients Suffering from Psychopathological Disorders Arising from Bullying at Work

    ERIC Educational Resources Information Center

    Lac, Gerard; Dutheil, Frederic; Brousse, Georges; Triboulet-Kelly, Celine; Chamoux, Alain

    2012-01-01

    Background: Psychological disorders arising from bullying at work (BW) are common. The relationship between these disorders and putative markers is not well established. Aims: To measure saliva dehydroepiandrosterone sulphate (DHEAS) and saliva cortisol as putative markers in individuals suffering from BW. Methods: Forty one subjects suffering…

  13. 32 CFR 536.116 - Responsibilities as to claims arising overseas under international agreements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for maneuver damage and tort claims classified according to major categories of damage determined by... 32 National Defense 3 2014-07-01 2014-07-01 false Responsibilities as to claims arising overseas... (Continued) DEPARTMENT OF THE ARMY CLAIMS AND ACCOUNTS CLAIMS AGAINST THE UNITED STATES Claims...

  14. 75 FR 19873 - Collection of Administrative Debts; Collection of Debts Arising From Enforcement and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-16

    ... From Enforcement and Administration of Campaign Finance Laws, 75 FR 8274 (February 24, 2010) (the... Collection of Administrative Debts; Collection of Debts Arising From Enforcement and Administration of... collection of debts owed to the United States Government. The Commission is also integrating its...

  15. 75 FR 8274 - Collection of Administrative Debts; Collection of Debts Arising From Enforcement and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-24

    ...; ] FEDERAL ELECTION COMMISSION 11 CFR Parts 8 and 111 Collection of Administrative Debts; Collection of Debts... comments on proposed rules implementing statutory provisions regarding the collection of debts owed to the... debts arising solely from the Administrative Fines program into the new proposed rules. DATES:...

  16. 5 CFR 315.805 - Termination of probationers for conditions arising before appointment.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 1 2012-01-01 2012-01-01 false Termination of probationers for conditions arising before appointment. 315.805 Section 315.805 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CAREER AND CAREER-CONDITIONAL EMPLOYMENT Probation on Initial...

  17. 5 CFR 315.805 - Termination of probationers for conditions arising before appointment.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Termination of probationers for conditions arising before appointment. 315.805 Section 315.805 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CAREER AND CAREER-CONDITIONAL EMPLOYMENT Probation on Initial...

  18. 5 CFR 315.805 - Termination of probationers for conditions arising before appointment.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 1 2013-01-01 2013-01-01 false Termination of probationers for conditions arising before appointment. 315.805 Section 315.805 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CAREER AND CAREER-CONDITIONAL EMPLOYMENT Probation on Initial...

  19. Selective Short-Term Memory Deficits Arise from Impaired Domain-General Semantic Control Mechanisms

    ERIC Educational Resources Information Center

    Hoffman, Paul; Jefferies, Elizabeth; Ehsan, Sheeba; Hopper, Samantha; Lambon Ralph, Matthew A.

    2009-01-01

    Semantic short-term memory (STM) patients have a reduced ability to retain semantic information over brief delays but perform well on other semantic tasks; this pattern suggests damage to a dedicated buffer for semantic information. Alternatively, these difficulties may arise from mild disruption to domain-general semantic processes that have…

  20. 28 CFR 45.2 - Disqualification arising from personal or political relationship.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... political relationship. 45.2 Section 45.2 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMPLOYEE RESPONSIBILITIES § 45.2 Disqualification arising from personal or political relationship. (a) Unless authorized... prosecution if he has a personal or political relationship with: (1) Any person or organization...

  1. 28 CFR 45.2 - Disqualification arising from personal or political relationship.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... political relationship. 45.2 Section 45.2 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMPLOYEE RESPONSIBILITIES § 45.2 Disqualification arising from personal or political relationship. (a) Unless authorized... prosecution if he has a personal or political relationship with: (1) Any person or organization...

  2. 28 CFR 45.2 - Disqualification arising from personal or political relationship.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... political relationship. 45.2 Section 45.2 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMPLOYEE RESPONSIBILITIES § 45.2 Disqualification arising from personal or political relationship. (a) Unless authorized... prosecution if he has a personal or political relationship with: (1) Any person or organization...

  3. 28 CFR 45.2 - Disqualification arising from personal or political relationship.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... political relationship. 45.2 Section 45.2 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMPLOYEE RESPONSIBILITIES § 45.2 Disqualification arising from personal or political relationship. (a) Unless authorized... prosecution if he has a personal or political relationship with: (1) Any person or organization...

  4. 28 CFR 45.2 - Disqualification arising from personal or political relationship.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... political relationship. 45.2 Section 45.2 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) EMPLOYEE RESPONSIBILITIES § 45.2 Disqualification arising from personal or political relationship. (a) Unless authorized... prosecution if he has a personal or political relationship with: (1) Any person or organization...

  5. Where Cognitive Conflict Arises from?: The Structure of Creating Cognitive Conflict

    ERIC Educational Resources Information Center

    Lee, Gyoungho; Yi, Jinseog

    2013-01-01

    In this study, our basic contention was that it is essential for researchers to answer the question, "Where does cognitive conflict really arise from?" with more precision than has heretofore been attempted. First, we examined how the term "cognitive conflict" has been treated in the existing literature and try to pinpoint some difficulties,…

  6. 45 CFR 73.735-1304 - Referral of matters arising under the standards of this part.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Referral of matters arising under the standards of this part. 73.735-1304 Section 73.735-1304 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES... under the standards of this part. (a) The Department Ethics Counselor may refer to the Inspector...

  7. Colonic-type adenocarcinoma arising in a primary retroperitoneal mature cystic teratoma.

    PubMed

    Cheung, Wang L; Cao, Dengfeng

    2008-12-01

    A 47-year-old woman who presented with abdominal pain was found to have a 20 cm cystic retroperitoneal mass. Pathology indicated a colonic-type adenocarcinoma arising in a primary retroperitoneal mature cystic teratoma. The adenocarcinoma was predominantly intracystic with focal superficial invasion into the cyst wall but not beyond the teratoma capsule. Immunohistochemistry showed that the adenocarcinoma cells were diffusely positive for cytokeratin 20 (CK20) and caudal-type homeobox transcription factor-2 (CDX2) but negative for CK7, confirming the colonic phenotype. In addition, the adenocarcinoma was seen adjacent to teratomatous colonic-type mucosa with adenomatous change (i.e. adenoma), suggesting that it was probably arising from a colonic-type adenoma within the teratoma. The carcinoma had a higher Ki-67 proliferation index and had a higher percentage of cells stained for p53 than the adjacent adenomatous lesion. To the authors' knowledge this is the first documented case in which a colonic-type adenocarcinoma was seen arising from a precursor lesion (i.e. a colonic-type adenoma in a primary retroperitoneal mature cystic teratoma) and is the second case of intestinal-type adenocarcinoma arising in a primary retroperitoneal mature cystic teratoma.

  8. Adenocarcinoma arising in retroperitoneal enterogenous cyst presenting as a renal cyst: report of an unusual case.

    PubMed

    Marrogi, A J; Chehval, M; Martin, S A

    1991-06-01

    A single case of an adenocarcinoma, arising in a retroperitoneal enterogenous cyst and which presented as a left renal cyst, is reported. Review of literature showed a total of 13 other reported cases. The prognosis of such patients appears to correlate with the presence of regional lymph node metastasis and the resectability of the tumor.

  9. Adenocarcinoma arising in colonic duplication cysts with calcification: CT findings of two cases.

    PubMed

    Inoue, Y; Nakamura, H

    1998-01-01

    We report the computed tomographic findings of mucinous adenocarcinoma with calcification arising from duplication cyst of the colon in two adult cases. In both cases, serum levels of carcinoembryonic antigen (CEA) were high. Differential diagnosis of intraperitoneal or retroperitoneal cystic tumors with mucinous density includes duplication cyst, and its malignant change should be considered when serum level of CEA is high.

  10. 5 CFR 315.805 - Termination of probationers for conditions arising before appointment.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Termination of probationers for conditions arising before appointment. 315.805 Section 315.805 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CAREER AND CAREER-CONDITIONAL EMPLOYMENT Probation on Initial...

  11. 5 CFR 315.805 - Termination of probationers for conditions arising before appointment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Termination of probationers for conditions arising before appointment. 315.805 Section 315.805 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS CAREER AND CAREER-CONDITIONAL EMPLOYMENT Probation on Initial...

  12. Endocrine tumour in kidney affecting small bowel structure, motility, and absorptive function 1

    PubMed Central

    Gleeson, M. H.; Bloom, S. R.; Polak, J. M.; Henry, K.; Dowling, R. H.

    1971-01-01

    A 44-year-old woman is described with an endocrine tumour arising in the kidney. There were associated abnormalities of small intestinal morphology, motility, and absorptive function. These abnormalities reversed on removal of the tumour. Detailed studies showed that the tumour contained, and was secreting, glucagon. It is postulated that the intestinal abnormalities may have resulted from glucagon itself or another, as yet unidentified, hormone. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6 PMID:4941684

  13. Feature selection in bioinformatics

    NASA Astrophysics Data System (ADS)

    Wang, Lipo

    2012-06-01

    In bioinformatics, there are often a large number of input features. For example, there are millions of single nucleotide polymorphisms (SNPs) that are genetic variations which determine the dierence between any two unrelated individuals. In microarrays, thousands of genes can be proled in each test. It is important to nd out which input features (e.g., SNPs or genes) are useful in classication of a certain group of people or diagnosis of a given disease. In this paper, we investigate some powerful feature selection techniques and apply them to problems in bioinformatics. We are able to identify a very small number of input features sucient for tasks at hand and we demonstrate this with some real-world data.

  14. Volcanic features of Io

    USGS Publications Warehouse

    Carr, M.H.; Masursky, H.; Strom, R.G.; Terrile, R.J.

    1979-01-01

    Volcanic activity is apparently higher on Io than on any other body in the Solar System. Its volcanic landforms can be compared with features on Earth to indicate the type of volcanism present on Io. ?? 1979 Nature Publishing Group.

  15. Simulating Arctic clouds during Arctic Radiation- IceBridge Sea and Ice Experiment (ARISE)

    NASA Astrophysics Data System (ADS)

    Bromwich, D. H.; Hines, K. M.; Wang, S. H.

    2015-12-01

    The representation within global and regional models of the extensive low-level cloud cover over polar oceans remains a critical challenge for quantitative studies and forecasts of polar climate. In response, the polar-optimized version of the Weather Research and Forecasting model (Polar WRF) is used to simulate the meteorology, boundary layer, and Arctic clouds during the September-October 2014 Arctic Radiation- IceBridge Sea and Ice Experiment (ARISE) project. Polar WRF was developed with several adjustments to the sea ice thermodynamics in WRF. ARISE was based out of Eielson Air Force Base near Fairbanks, Alaska and included multiple instrumented C-130 aircraft flights over open water and sea ice of the Beaufort Sea. Arctic boundary layer clouds were frequently observed within cold northeasterly flow over the open ocean and ice. Preliminary results indicate these clouds were primarily liquid water, with characteristics differing between open water and sea ice surfaces. Simulated clouds are compared to ARISE observations. Furthermore, Polar WRF simulations are run for the August-September 2008 Arctic Summer Cloud Ocean Study (ASCOS) for comparison to the ARISE. Preliminary analysis shows that simulated low-level water clouds over the sea ice are too extensive during the the second half of the ASCOS field program. Alternatives and improvements to the Polar WRF cloud schemes are considered. The goal is to use the ARISE and ASCOS observations to achieve an improved polar supplement to the WRF code for open water and sea ice that can be provided to the Polar WRF community.

  16. Feature Characterization Library

    2006-08-03

    FCLib is a data analysis toolkit constructed to meet the needs of data discovery in large-scale, spatio-temporal data such as finite element simulation data. FCLib is a C library toolkit of building blocks that can be assembled into complex analyses. Important features of FCLib include the following: (1) Support of feature-based analysis, (2) minimization of low-oevel processing, (3) ease of use, and (4) applicable to the wide variety of science domains.

  17. Propagation-invariant classification of sounds in channels with dispersion and absorption.

    PubMed

    Okopal, Greg; Loughlin, Patrick J

    2010-11-01

    In a previous paper [G. Okopal et al., J. Acoust. Soc. Am. 123, 832-841 (2008)], a method to obtain features of a wave that are unaffected by dispersion, per mode, was developed for improving classification of underwater sounds (e.g., sonar backscatter). The current paper builds on this work and presents additional contributions. First, it is shown that the dispersion-invariant moments developed previously are not invariant to frequency-dependent attenuation (absorption); consequently, their classification performance degrades in such channels. Second, a feature extraction method is developed to obtain features that are invariant to dispersion, and to two forms of absorption (known a priori): namely, absorption that yields spectral magnitude attenuation (in dB) that is linear with frequency, and linear with log-frequency. Third, the relationship of these absorption- and dispersion-invariant moment (ADIM) features to the cepstrum of the wave is examined, and it is shown that cepstral moments are also invariant to dispersion, and to the first form of absorption for odd-order moments. Finally, simulations are conducted to illustrate the performance of the ADIMs and cepstral moments on classifying the backscatter from steel shells in a dispersive channel with absorption. Receiver operator characteristic curves quantify the superior discriminability of the ADIMs and cepstral moments compared to ordinary moments.

  18. Cosensitization of D-A-π-A quinoxaline organic dye: efficiently filling the absorption valley with high photovoltaic efficiency.

    PubMed

    Pei, Kai; Wu, Yongzhen; Li, Hui; Geng, Zhiyuan; Tian, He; Zhu, Wei-Hong

    2015-03-11

    In the efficient cosensitization, the pure organic sensitizers with high molecular extinction coefficients and long wavelength response are highly preferable since the dye loading amount for each dye in cosensitization is decreased with respect to single dye sensitization. A D-A-π-A featured quinoxaline organic sensitizer IQ21 is specifically designed. The high conjugation building block of 4H-cyclopenta[2,1-b:3,4-b']dithiophene (CPDT) is introduced as the π bridge, instead of the traditional thiophene unit, especially in realizing high molecular extinction coefficients (up to 66 600 M(-1) cm(-1)) and extending the light response wavelength. With respect to the reference dye IQ4, the slightly lower efficiency of IQ21 (9.03%) arises from the decrease of VOC, which offsets the gain in JSC. While cosensitized with a smaller D-π-A dye S2, the efficiency in IQ21 is further improved to 10.41% (JSC = 19.8 mA cm(-2), VOC = 731 mV, FF = 0.72). The large improvement in efficiency is attributed to the well-matched molecular structures and loading amounts of both dyes in the cosensitization system. We also demonstrated that coabsorbent dye S2 can distinctly compensate the inherent drawbacks of IQ21, not only enhancing the response intensity of IPCE, making up the absorption defects around low wavelength region of IPCE, but also repressing the charge recombination rate to some extent.

  19. The hot DOA1 degenerate HZ 21 - A search for circumstellar/photospheric metals and peculiar absorption at He II

    NASA Technical Reports Server (NTRS)

    Fritz, M. L.; Leckenby, H.; Sion, E. M.; Vauclair, G.; Liebert, J.

    1990-01-01

    A high-resolution IUE spectrum of the hot DO1 degenerate HZ 21 was obtained by combining US1 + European 2 low-background observing shifts. The SWP image reveals a rich spectrum of interstellar absorption lines with an average velocity in the line of sight to HZ 21 of -30 km/s. However, there is no clear evidence of any highly or lowly ionized metal features which could be attributed to circumstellar, wind, or photospheric absorption. There is, however, a broad absorption trough at He II (1640) which was not unexpected, given the clear presence of He II (4686) absorption in this star's optical spectrum. The velocity width of He II (1640) appears consistent with photospheric absorption wings which appear to flank the geocoronal Ly-alpha emission feature. The He II (1640) feature reveals what appears to be a broad (310 km/s) emission reversal. Evidence is provided that the emission reversal is probably real.

  20. Monte Carlo Simulation for Quantification of Light Transport Features in Apples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Light interaction with turbid biological materials involves absorption and scattering. Quantitative understanding of light propagation features in the fruit is critical to designing better optical systems for inspection of food quality. This article reports on the quantification of light propagation...

  1. Landing gear energy absorption system

    NASA Technical Reports Server (NTRS)

    Hansen, Christopher P. (Inventor)

    1994-01-01

    A landing pad system is described for absorbing horizontal and vertical impact forces upon engagement with a landing surface where circumferentially arranged landing struts respectively have a clevis which receives a slidable rod member and where the upper portion of a slidable rod member is coupled to the clevis by friction washers which are force fit onto the rod member to provide for controlled constant force energy absorption when the rod member moves relative to the clevis. The lower end of the friction rod is pivotally attached by a ball and socket to a support plate where the support plate is arranged to slide in a transverse direction relative to a housing which contains an energy absorption material for absorbing energy in a transverse direction.

  2. Photodetector with enhanced light absorption

    DOEpatents

    Kane, James

    1985-01-01

    A photodetector including a light transmissive electrically conducting layer having a textured surface with a semiconductor body thereon. This layer traps incident light thereby enhancing the absorption of light by the semiconductor body. A photodetector comprising a textured light transmissive electrically conducting layer of SnO.sub.2 and a body of hydrogenated amorphous silicon has a conversion efficiency about fifty percent greater than that of comparative cells. The invention also includes a method of fabricating the photodetector of the invention.

  3. Cryovolcanic Features on Titan

    NASA Astrophysics Data System (ADS)

    Lopes, R. M. C.; Stofan, E. R.; Kirk, R. L.; Mitchell, K. L.; LeGall, A.; Barnes, J. W.; Hayes, A.; Kargel, J.; Radebaugh, J.; Janssen, M. A.; Neish, C. D.; Wood, C.; Wall, S. D.; Lunine, J. I.; Malaska, M. J.

    2013-09-01

    We present evidence to support the cryovolcanic origin of some features, which includes the deepest pit known on Titan (Sotra Patera) and some of the highest mountains (Doom and Erebor Montes). We interpret this region to be a cryovolcanic complex of multiple cones, craters, and flows. Elsewhere, a circular feature, approximately 100 km across, is morphologically similar to a laccolith, showing a cross pattern interpreted to be extensional fractures. However, we find that some other previously supposed cryovolcanic features were likely formed by other processes. We discuss implications for eruption style and composition of cryovolcanism on Titan. Our analysis shows the great value of combining data sets when interpreting Titan's geology and in particular stresses the value of topographic data.

  4. Three featured plenary sessions

    NASA Astrophysics Data System (ADS)

    2012-07-01

    The conference included three plenary sessions. The plenary on Governance, Security, Economy, and the Ecosystem of the Changing Arctic featured Vera Alexander, president, Arctic Research Consortium of the U.S.; Alan Thornhill, chief environmental officer, U.S. Department of the Interior's Bureau of Ocean Energy Management; and Fran Ulmer, chair, U.S. Arctic Research Commission. A plenary on the U.N. Convention on the Law of the Sea featured Ambassador David Balton, deputy assistant secretary for oceans and fisheries, U.S. Department of State; and Rear Admiral Frederick Kenney Jr., judge advocate general and chief counsel, U.S. Coast Guard. The plenary on Science and the 21st Century featured Phil Keslin, chief technology officer, small lab within Google.

  5. Neuroendocrine tumor arising de novo in the left upper thigh: a case report.

    PubMed

    Păun, Ion; Costin, Andrei; Păun, Mariana; Ţenovici, Mihaela; Georgescu, Claudia Valentina; Georgescu, Corneliu Cristian; Constantin, Vlad Denis

    2015-01-01

    Neuroendocrine tumors (NETs) originate in the neuroendocrine cells of the neural crest (Kulchitsky cells). If neuroendocrine tumors arising in the digestive tract or lung may occasionally result in skin metastases, primary soft tissue or skin NETs are infrequent. The current paper presents the case of an elderly woman patient with neuroendocrine tumors arising de novo in the left upper thigh, accompanied by lymph nodes metastases in the left groin and in the left pelvic sidewall, in close vicinity of the iliac vessels. The diagnosis of NET was performed based on immunohistochemical tests. Such tumors show a slow growth and, generally, have a good prognosis. It is emphasized that complete surgical excision, in some cases associated with adjuvant external radiotherapy is the optimal therapeutic modality in dealing with such lesions. PMID:26429186

  6. Osteochondroma of maxillofacial region: Tumor arising from two different developmental bones

    PubMed Central

    Mohanty, Sujata; Gupta, Himanshu; Dabas, Jitender; Kumar, Priyadarshan

    2016-01-01

    Osteochondromas are benign bony tumors which are commonly believed to originate by the proliferation of epiphyseal cartilage into the surrounding tissues. However, this hypothesis cannot explain the occurrence of this tumor in the intramembranous bones and soft tissue. Since most of the craniofacial bones have intramembranous origin, the occurrence of this lesion in this territory is considered rare. Contrary to the above hypothesis, Lichtenstein proposed that this entity arises from the metaplastic changes in the periosteum which explains the occurrence of this tumor in endochondral as well as intramembranous bones and also in soft tissues. Complying with Lichtenstein's hypothesis, the authors are presenting two cases of osteochondromas with one arising from the endochondral bone (the coronoid process of the mandible) and the other from an intramembranous bone (lateral pterygoid plate of the sphenoid). PMID:27601834

  7. Neuroendocrine tumor arising de novo in the left upper thigh: a case report.

    PubMed

    Păun, Ion; Costin, Andrei; Păun, Mariana; Ţenovici, Mihaela; Georgescu, Claudia Valentina; Georgescu, Corneliu Cristian; Constantin, Vlad Denis

    2015-01-01

    Neuroendocrine tumors (NETs) originate in the neuroendocrine cells of the neural crest (Kulchitsky cells). If neuroendocrine tumors arising in the digestive tract or lung may occasionally result in skin metastases, primary soft tissue or skin NETs are infrequent. The current paper presents the case of an elderly woman patient with neuroendocrine tumors arising de novo in the left upper thigh, accompanied by lymph nodes metastases in the left groin and in the left pelvic sidewall, in close vicinity of the iliac vessels. The diagnosis of NET was performed based on immunohistochemical tests. Such tumors show a slow growth and, generally, have a good prognosis. It is emphasized that complete surgical excision, in some cases associated with adjuvant external radiotherapy is the optimal therapeutic modality in dealing with such lesions.

  8. A case of solitary fibrous tumor arising from the palatine tonsil.

    PubMed

    Kanazawa, Takeharu; Kodama, Kozue; Nokubi, Mitsuhiro; Gotsu, Kazuo; Shinnabe, Akihiro; Hasegawa, Masayo; Kusaka, Gen; Iino, Yukiko

    2015-03-01

    Solitary fibrous tumor (SFT) is a distinctive, relatively uncommon soft-tissue neoplasm that usually arises from the pleura. It occurs at various sites; head and neck lesions are very rare. While most of these tumors have a benign course, a small number have malignant potential. We describe a rare case of SFT arising from the left palatine tonsil in a 66-year-old Japanese woman. The mass was completely resected. Immunohistochemical studies were strongly positive for CD34 and bcl-2, mildly positive for phosphorylated protein kinase B and phosphorylated extracellular signal-regulated kinase 1/2, and negative for platelet-derived growth factor receptor alpha and p53. These findings suggested that this tumor was benign. The patient showed no evidence of recurrence during 2 years of follow-up. We believe that the candidate prognostic marker should be checked to distinguish malignant from benign SFTs.

  9. A case of solitary fibrous tumor arising from the palatine tonsil.

    PubMed

    Kanazawa, Takeharu; Kodama, Kozue; Nokubi, Mitsuhiro; Gotsu, Kazuo; Shinnabe, Akihiro; Hasegawa, Masayo; Kusaka, Gen; Iino, Yukiko

    2015-03-01

    Solitary fibrous tumor (SFT) is a distinctive, relatively uncommon soft-tissue neoplasm that usually arises from the pleura. It occurs at various sites; head and neck lesions are very rare. While most of these tumors have a benign course, a small number have malignant potential. We describe a rare case of SFT arising from the left palatine tonsil in a 66-year-old Japanese woman. The mass was completely resected. Immunohistochemical studies were strongly positive for CD34 and bcl-2, mildly positive for phosphorylated protein kinase B and phosphorylated extracellular signal-regulated kinase 1/2, and negative for platelet-derived growth factor receptor alpha and p53. These findings suggested that this tumor was benign. The patient showed no evidence of recurrence during 2 years of follow-up. We believe that the candidate prognostic marker should be checked to distinguish malignant from benign SFTs. PMID:25738718

  10. Osteochondroma of maxillofacial region: Tumor arising from two different developmental bones.

    PubMed

    Mohanty, Sujata; Gupta, Himanshu; Dabas, Jitender; Kumar, Priyadarshan

    2016-01-01

    Osteochondromas are benign bony tumors which are commonly believed to originate by the proliferation of epiphyseal cartilage into the surrounding tissues. However, this hypothesis cannot explain the occurrence of this tumor in the intramembranous bones and soft tissue. Since most of the craniofacial bones have intramembranous origin, the occurrence of this lesion in this territory is considered rare. Contrary to the above hypothesis, Lichtenstein proposed that this entity arises from the metaplastic changes in the periosteum which explains the occurrence of this tumor in endochondral as well as intramembranous bones and also in soft tissues. Complying with Lichtenstein's hypothesis, the authors are presenting two cases of osteochondromas with one arising from the endochondral bone (the coronoid process of the mandible) and the other from an intramembranous bone (lateral pterygoid plate of the sphenoid). PMID:27601834

  11. Desmoplastic Ameloblastoma Arising in a Dentigerous Cyst – A Case Report and Discussion

    PubMed Central

    Shamsudeen, Shaik Mohamed; Srinivasan, Satish Kumar; Kumar, S. Nalin; Pulikkottil, Tyson Babu

    2016-01-01

    Dentigerous cyst is a fairly common odontogenic cyst with an uncomplicated prognosis. However, reports of odontogenic and non-odontogenic tumors arising from the cysts have been published for many years. Therefore, the importance of thorough histopathological examination and regular follow-up cannot be overemphasized. Here is a case report of a possible development of desmoplastic ameloblastoma from a dentigerous cyst. This case is unique for two main reasons. Firstly, to our knowledge such a case has not been reported previously. Secondly, the tumor seemed to arise from the capsule and not from lining of the dentigerous cyst. Transformation of odontogenic rests into cysts is known to occur in the syndromic cases of odontogenic keratocysts (resulting in recurrent and daughter cysts) but not in dentigerous cysts. This case report may prompt greater interest in the role of the supposedly inactive odontogenic nests in the capsule of these cysts. PMID:27656586

  12. Dual Stent-Assisted Coil Embolization for Fusiform Aneurysm Arising From Persistent Trigeminal Artery

    PubMed Central

    John, Dickinson

    2016-01-01

    Aneurysms of the persistent trigeminal artery (PTA) trunk are exceptionally rare and have a high risk for rupture. Dual stent placement through each internal carotid and basilar artery for endovascular coil embolization of a fusiform aneurysm arising from the PTA has not been described in the literature. A 44-year-old female with a history of chronic headache was identified to have a fusiform aneurysm arising from medially coursing adult type, Saltzman type 3 PTA trunk. Sacrifice of the PTA trunk inclusive of the aneurysm was performed with dual stent placement through each basilar and internal carotid artery across their respective junctions with the PTA. Six-month follow-up angiography showed complete occlusion of the PTA and the aneurysm. The patient's symptoms resolved. Our case demonstrated that the sacrifice of an adult type, Saltzman type 3 PTA inclusive of an associated fusiform aneurysm is feasible with dual stent-assisted coil embolization.

  13. Desmoplastic Ameloblastoma Arising in a Dentigerous Cyst - A Case Report and Discussion.

    PubMed

    Jayanandan, Muruganandhan; Shamsudeen, Shaik Mohamed; Srinivasan, Satish Kumar; Kumar, S Nalin; Pulikkottil, Tyson Babu

    2016-08-01

    Dentigerous cyst is a fairly common odontogenic cyst with an uncomplicated prognosis. However, reports of odontogenic and non-odontogenic tumors arising from the cysts have been published for many years. Therefore, the importance of thorough histopathological examination and regular follow-up cannot be overemphasized. Here is a case report of a possible development of desmoplastic ameloblastoma from a dentigerous cyst. This case is unique for two main reasons. Firstly, to our knowledge such a case has not been reported previously. Secondly, the tumor seemed to arise from the capsule and not from lining of the dentigerous cyst. Transformation of odontogenic rests into cysts is known to occur in the syndromic cases of odontogenic keratocysts (resulting in recurrent and daughter cysts) but not in dentigerous cysts. This case report may prompt greater interest in the role of the supposedly inactive odontogenic nests in the capsule of these cysts. PMID:27656586

  14. Dual Stent-Assisted Coil Embolization for Fusiform Aneurysm Arising From Persistent Trigeminal Artery

    PubMed Central

    John, Dickinson

    2016-01-01

    Aneurysms of the persistent trigeminal artery (PTA) trunk are exceptionally rare and have a high risk for rupture. Dual stent placement through each internal carotid and basilar artery for endovascular coil embolization of a fusiform aneurysm arising from the PTA has not been described in the literature. A 44-year-old female with a history of chronic headache was identified to have a fusiform aneurysm arising from medially coursing adult type, Saltzman type 3 PTA trunk. Sacrifice of the PTA trunk inclusive of the aneurysm was performed with dual stent placement through each basilar and internal carotid artery across their respective junctions with the PTA. Six-month follow-up angiography showed complete occlusion of the PTA and the aneurysm. The patient's symptoms resolved. Our case demonstrated that the sacrifice of an adult type, Saltzman type 3 PTA inclusive of an associated fusiform aneurysm is feasible with dual stent-assisted coil embolization. PMID:27621951

  15. Vesical clear cell adenocarcinoma arising from endometriosis: A mullerian tumor, indistinguishable from ovarian clear cell adenocarcinoma.

    PubMed

    Miller, Eirwen M; Sun, Ying; Richardson, Ingride; Frimer, Marina

    2016-11-01

    Endometriosis is associated with increased rates of ovarian, particularly clear cell, adenocarcinomas. Malignant transformation of ovarian endometriosis is most common but rare cases have been reported in the bladder, abdominal wall, diaphragm, and rectum. We present the case of a 44-year-old female with vesical clear cell adenocarcinoma arising in a background of endometriosis in the absence of other pelvic endometriosis. The malignancy was diagnosed on transurethral resection of bladder tumor and managed with radical surgery. Histology and immunohistochemical findings were consistent mullerian origin and indistinguishable from similar tumors arising in the female genital tract. Extrapolating from the gynecologic literature, the recommendation was made for adjuvant chemotherapy. Further studies are needed to clarify the optimal treatment paradigm for ovarian and bladder clear cell adenocarcinomas. PMID:27660815

  16. Lesions Arising in a Tattoo of an Active Duty US Marine Corps Woman.

    PubMed

    Winn, Aubrey E; Rivard, Shayna C; Green, Brian

    2016-01-01

    Tattoos are ubiquitous in modern society; however, they do not come without risk of medical complications. When complications arise in the military community, a particularly thorough differential diagnosis should be considered based on the increased exposures service members have during deployment and throughout their military career. We present a case of a 38-year-old active duty US Marine Corps woman with worsening skin lesions arising within a tattoo 6 weeks after acquiring the tattoo on her right chest. Given environmental exposures from a recent deployment to the Middle East, a wide differential was considered. Ultimately, a skin biopsy revealed early hypertrophic scar formation responsive to therapy with intralesional triamcinolone acetonide (Kenalog® [ILK]). However, given the Marine had recently deployed and is part of the active duty population, consideration of alternative, albeit rare, etiologies was imperative. PMID:27450611

  17. Dual Stent-Assisted Coil Embolization for Fusiform Aneurysm Arising From Persistent Trigeminal Artery.

    PubMed

    Ajeet, Gordhan; John, Dickinson

    2016-09-01

    Aneurysms of the persistent trigeminal artery (PTA) trunk are exceptionally rare and have a high risk for rupture. Dual stent placement through each internal carotid and basilar artery for endovascular coil embolization of a fusiform aneurysm arising from the PTA has not been described in the literature. A 44-year-old female with a history of chronic headache was identified to have a fusiform aneurysm arising from medially coursing adult type, Saltzman type 3 PTA trunk. Sacrifice of the PTA trunk inclusive of the aneurysm was performed with dual stent placement through each basilar and internal carotid artery across their respective junctions with the PTA. Six-month follow-up angiography showed complete occlusion of the PTA and the aneurysm. The patient's symptoms resolved. Our case demonstrated that the sacrifice of an adult type, Saltzman type 3 PTA inclusive of an associated fusiform aneurysm is feasible with dual stent-assisted coil embolization. PMID:27621951

  18. Complex Population Dynamics in Mussels Arising from Density-Linked Stochasticity

    PubMed Central

    Wootton, J. Timothy; Forester, James D.

    2013-01-01

    Population fluctuations are generally attributed to the deterministic consequences of strong non-linear interactions among organisms, or the effects of random stochastic environmental variation superimposed upon the deterministic skeleton describing population change. Analysis of the population dynamics of the mussel Mytilus californianus taken in 16 plots over 18-years found no evidence that these processes explained observed strong fluctuations. Instead, population fluctuations arose because environmental stochasticity varied with abundance, which we term density-linked stochasticity. This phenomenon arises from biologically relevant mechanisms: recruitment variation and transmission of disturbance among neighboring individuals. Density-linked stochasticity is probably present frequently in populations, as it arises naturally from several general ecological processes, including stage structure variation with density, ontogenetic niche shifts, and local transmission of stochastic perturbations. More thoroughly characterizing and interpreting deviations from the mean behavior of a system will lead to better ecological prediction and improved insight into the important processes affecting populations and ecosystems. PMID:24086617

  19. Osteochondroma of maxillofacial region: Tumor arising from two different developmental bones

    PubMed Central

    Mohanty, Sujata; Gupta, Himanshu; Dabas, Jitender; Kumar, Priyadarshan

    2016-01-01

    Osteochondromas are benign bony tumors which are commonly believed to originate by the proliferation of epiphyseal cartilage into the surrounding tissues. However, this hypothesis cannot explain the occurrence of this tumor in the intramembranous bones and soft tissue. Since most of the craniofacial bones have intramembranous origin, the occurrence of this lesion in this territory is considered rare. Contrary to the above hypothesis, Lichtenstein proposed that this entity arises from the metaplastic changes in the periosteum which explains the occurrence of this tumor in endochondral as well as intramembranous bones and also in soft tissues. Complying with Lichtenstein's hypothesis, the authors are presenting two cases of osteochondromas with one arising from the endochondral bone (the coronoid process of the mandible) and the other from an intramembranous bone (lateral pterygoid plate of the sphenoid).

  20. Delayed luminescence of biological systems arising from correlated many-soliton states

    NASA Astrophysics Data System (ADS)

    Brizhik, Larissa; Scordino, Agata; Triglia, Antonio; Musumeci, Francesco

    2001-09-01

    The kinetics of the delayed luminescence arising from correlated coherent many-soliton states in low-dimensional macromolecular systems, is calculated and shown to be different from the one arising from independent soliton states. The correlation between coherent electron states is essential at relatively high levels of excitation in the presence of very long macromolecules in a system. These conditions can be fulfilled in such biological systems, like algae Acetabularia Acetabulum. The cytoskeleton of this unicellular alga contains macromolecular structures (actin filaments, microtubules, etc.) of the length of several hundreds angstroms and more, in which many-soliton coherent states can exist. Indeed, the correlated coherent model is shown to give better fit of the experimental data for this type of algae in a wide range of intensities of the stimulating light, as compared with the model of noncorrelated solitons. The nonlinearity of the dependence of delayed luminescence intensity on the level of excitation increases with the increase of correlation between solitons.

  1. Detectability of cold streams into high-redshift galaxies by absorption lines

    NASA Astrophysics Data System (ADS)

    Goerdt, Tobias; Dekel, Avishai; Sternberg, Amiel; Gnat, Orly; Ceverino, Daniel

    2012-08-01

    Cold gas streaming along the dark matter filaments of the cosmic web is predicted to be the major source of fuel for disc buildup, violent disc instability and star formation in massive galaxies at high redshift. We investigate to what extent such cold gas is detectable in the extended circumgalactic environment of galaxies via Lyα absorption and selected low-ionization metal absorption lines. We model the expected absorption signatures using high-resolution zoom-in adaptive mesh refinement cosmological simulations. In the post-processing, we distinguish between self-shielded gas and unshielded gas. In the self-shielded gas, which is optically thick to Lyman continuum radiation, we assume pure collisional ionization for species with an ionization potential greater than 13.6 eV. In the optically-thin, unshielded gas, these species are also photoionized by the metagalactic radiation. In addition to absorption of radiation from background quasars, we compute the absorption line profiles of radiation emitted by the galaxy at the centre of the same halo. We predict the strength of the absorption signal for individual galaxies without stacking. We find that the Lyα absorption profiles produced by the streams are consistent with observations of absorption and emission Lyα profiles in high-redshift galaxies. Due to the low metallicities in the streams, and their low covering factors, the metal absorption features are weak and difficult to detect.

  2. Influence of texture modifications in silicon solar cells on absorption in the intrinsic layers

    NASA Astrophysics Data System (ADS)

    Ermes, M.; Bittkau, K.; Carius, R.

    2012-06-01

    The influence of the front texture of an etched transparent conductive oxide with crater-like structures of various sizes on the absorption of a thin amorphous silicon (a-Si:H) layer is investigated by rigorous optical simulations as part of two simplified systems: A simplified single junction device, using a perfect metal as back contact and a top cell of an amorphous/microcrystalline silicon tandem device, using a microcrystalline silicon halfspace adjacent to the amorphous layer. The texture is modified by stretching either in height or laterally and the average absorption in the a-Si:H layer is investigated relative to the original structure. We investigate the average absorption for each wavelength as well as the total absorption, weighted with an AM1.5g spectrum. Furthermore, the local absorption distribution inside the a-Si:H layer is examined to improve the understanding of local texture features and their influence on absorption and cell performance. For both modifications, an optimal point can be found to improve the absorption in the amorphous layer by up to 15% and 6% for a simplified single junction and tandem top cell, respectively. In case of the top cell of the simplified tandem device, it is found that additionally, the transmission into the microcrystalline silicon can be improved. Also, the local absorption distribution shows that there is an optimal size of the surface craters for all modifications, while steeper crater rims in general lead to higher absorption.

  3. Learning trees and rules with set-valued features

    SciTech Connect

    Cohen, W.W.

    1996-12-31

    In most learning systems examples are represented as fixed-length {open_quotes}feature vectors{close_quotes}, the components of which are either real numbers or nominal values. We propose an extension of the feature-vector representation that allows the value of a feature to be a set of strings; for instance, to represent a small white and black dog with the nominal features size and species and the set-valued feature color, one might use a feature vector with size-small, species-canis-familiaris and color-(white, black). Since we make no assumptions about the number of possible set elements, this extension of the traditional feature-vector representation is closely connected to Blum`s {open_quotes}infinite attribute{close_quotes} representation. We argue that many decision tree and rule learning algorithms can be easily extended to set-valued features. We also show by example that many real-world learning problems can be efficiently and naturally represented with set-valued features; in particular, text categorization problems and problems that arise in propositionalizing first-order representations lend themselves to set-valued features.

  4. Incidental findings arising with cone beam computed tomography imaging of the orthodontic patient.

    PubMed

    Rogers, Sheelagh A; Drage, Nicholas; Durning, Peter

    2011-03-01

    Cone beam computed tomography (CBCT) of orthodontic patients is a diagnostic tool used increasingly in hospital and primary care settings. It offers a high-diagnostic yield, short scanning times, and a lower radiation dose than conventional computed tomography. This article reports on four incidental findings-that appear unrelated to the scan's original purpose-arising in patients for whom CBCT was carried out for orthodontic purposes. It underlines the need for complete reporting of the data set. PMID:21208090

  5. Atrial Tachycardias Arising from the Atrial Appendages and Aortic Sinus of Valsalva

    PubMed Central

    Taylor, Colleen M; Samardhi, Himabindu; Haqqani, Haris M

    2015-01-01

    Focal atrial tachycardias arising from the atrial appendages and the aortic sinuses of Valsalva are less frequently encountered in clinical practice. This review article describes the clinical presentation, surface P wave morphology, electrophysiologic characteristics and treatment of these arrhythmias. Catheter ablation of these focal tachycardias has a high success rate. It is however important to be aware of specific anatomic considerations in these locations for optimal treatment outcomes with low complication rates. PMID:25308812

  6. Birefringing arising from the reorientation of the polarizability anisotropy of molecules in collisionless gases

    NASA Technical Reports Server (NTRS)

    Lin, C. H.; Heritage, J. P.; Gustafson, T. K.; Chiao, R. Y.; Mctague, J. P.

    1974-01-01

    The refractive index change in a collisionless gas is evaluated from the Stark shifts of the rotational energy levels that arise from the polarizability anisotropy. For the limit of an extremely short-duration excitation, a multilevel coherent effect resulted in delayed refractive index bursts. Both stationary and transient responses of this birefringence to an optical field were considered for symmetric top molecules, with particular emphasis on the special case of linear molecules.

  7. Dynamics of the middle atmosphere as observed by the ARISE project

    NASA Astrophysics Data System (ADS)

    Blanc, E.

    2015-12-01

    It has been strongly demonstrated that variations in the circulation of the middle atmosphere influence weather and climate all the way to the Earth's surface. A key part of this coupling occurs through the propagation and breaking of planetary and gravity waves. However, limited observations prevent to faithfully reproduce the dynamics of the middle atmosphere in numerical weather prediction and climate models. The main challenge of the ARISE (Atmospheric dynamics InfraStructure in Europe) project is to combine existing national and international observation networks including: the International infrasound monitoring system developed for the CTBT (Comprehensive nuclear-Test-Ban Treaty) verification, the NDACC (Network for the Detection of Atmospheric Composition Changes) lidar network, European observation infrastructures at mid latitudes (OHP observatory), tropics (Maïdo observatory), high latitudes (ALOMAR and EISCAT), infrasound stations which form a dense European network and satellites. The ARISE network is unique by its coverage (polar to equatorial regions in the European longitude sector), its altitude range (from troposphere to mesosphere and ionosphere) and the involved scales both in time (from seconds to tens of years) and space (from tens of meters to thousands of kilometers). Advanced data products are produced with the scope to assimilate data in the Weather Prediction models to improve future forecasts over weeks and seasonal time scales. ARISE observations are especially relevant for the monitoring of extreme events such as thunderstorms, volcanoes, meteors and at larger scales, deep convection and stratospheric warming events for physical processes description and study of long term evolution with climate change. Among the applications, ARISE fosters integration of innovative methods for remote detection of non-instrumented volcanoes including distant eruption characterization to provide notifications with reliable confidence indices to the

  8. ROBUST CIRCUIT RHYTHMS IN SMALL CIRCUITS ARISE FROM VARIABLE CIRCUIT COMPONENTS AND MECHANISMS

    PubMed Central

    Marder, Eve; Goeritz, Marie L.; Otopalik, Adriane G.

    2014-01-01

    Small central pattern generating circuits found in invertebrates have significant advantages for the study of the circuit mechanisms that generate brain rhythms. Experimental and computational studies of small oscillatory circuits reveal that similar rhythms can arise from disparate mechanisms. Animal-to-animal variation in the properties of single neurons and synapses may underly robust circuit performance, and can be revealed by perturbations. Neuromodulation can produce altered circuit performance but also ensure reliable circuit function. PMID:25460072

  9. Novel representation of exponential functions of power series which arise in statistical mechanics and population genetics

    NASA Astrophysics Data System (ADS)

    Ma, W. T.; Sandri, G. vH.; Sarkar, S.

    1991-05-01

    We use the convolution power of infinite sequences to obtain a novel representation of exponential functions of power series which often arise in statistical mechanics. We thus obtain new formulas for the configuration and cluster integrals of pairwise interacting systems of molecules in an imperfect gas. We prove that the asymptotic behaviour of the Luria-Delbrück distribution is pn∼ cn-2. We derive a new, simple and computationally efficient recursion relation for pn.

  10. A Rare Case of Angiofibroma Arising from Inferior Turbinate in a Female

    PubMed Central

    Agarwal, Shilpi; Arora, Rubeena; Doloi, Pankaj; Kumar, Deepak

    2016-01-01

    A rare case of extranasopharyngeal angiofibroma arising from the inferior turbinate in a young female of 28 years is presented. The case is discussed in light of scant contemporary literature on the cited subject. This clinical record highlights the distinct clinical nature of Extranasopharyngeal angiofibroma (ENA) and importance of Immunohistochemistry in diagnosis of such lesions. With this case we report a rare clinical entity which presented in an extremely rare manner. PMID:27190846

  11. Birefringence arising from the reorientation of the polarizability anisotropy of molecules in collisionless gases

    NASA Technical Reports Server (NTRS)

    Lin, C. H.; Heritage, J. P.; Gustafson, T. K.; Chiao, R. Y.; Mctague, J. P.

    1976-01-01

    The refractive-index change in a collisionless gas is evaluated from the Stark shifts of the rotational energy levels that arise from the polarizability anisotropy. In the limit of an extremely-short-duration excitation, a multilevel coherent effect results in delayed refractive-index bursts. Both stationary and transient responses of this birefringence to an optical field are considered for symmetric-top molecules, with particular emphasis on the special case of linear molecules.

  12. Missed Total Occlusion Due to the Occipital Artery Arising from the Internal Carotid Artery

    SciTech Connect

    Ustunsoz, Bahri Gumus, Burcak; Koksal, Ali; Koroglu, Mert; Akhan, Okan

    2007-02-15

    A 56-year-old man was referred for digital subtraction angiography (DSA) with an ultrasound diagnosis of right proximal internal carotid artery (ICA) stenosis for possible carotid artery stenting. DSA revealed total occlusion of the ICA and an occipital artery arising from the stump and simulating continuation of the ICA. An ascending pharyngeal artery also arose from the same occipital artery. This case is of interest because this is a rare variation besides being a cause of misdiagnosis at carotid ultrasound.

  13. Tumoral mass presenting in the nasomalar region arising from the lateral nasal wall: pleomorphic adenoma.

    PubMed

    Uğuz, Mustafa Zafer; Onal, Kazim; Demiray, Utku; Ekinci, Neşe

    2007-11-01

    Pleomorphic adenoma is the most common benign salivary gland tumor. Although the major salivary glands are the most common sites of its origin, it can also occur in the minor salivary glands of the oral cavity and rarely in the neck, ear, nasal cavity and larynx. We report a rare case of intranasal pleomorphic adenoma arising from lateral nasal wall and discuss the clinical presentation, diagnosis and treatment approaches with the review of the literature.

  14. Substation fire protection features

    SciTech Connect

    Hausheer, T.G.

    1995-10-01

    This paper describes Commonwealth Edison`s (ComEd) approach to substation fire protection. Substation fires can have a major operational, financial, as well as political impact on a utility. The overall Company philosophy encompasses both active and passive fire protection features to provide prompt detection, notification, and confinement of fire and its by-products. Conservatively designed smoke detection systems and floor and wall penetration seals form the backbone of this strategy. The Company has implemented a program to install these features in new and existing substations. Thus far these measures have been successful in mitigating the consequences of substation fires.

  15. Escalator design features evaluation

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.; Deshpande, G. K.

    1982-01-01

    Escalators are available with design features such as dual speed (90 and 120 fpm), mat operation and flat steps. These design features were evaluated based on the impact of each on capital and operating costs, traffic flow, and safety. A human factors engineering model was developed to analyze the need for flat steps at various speeds. Mat operation of escalators was found to be cost effective in terms of energy savings. Dual speed operation of escalators with the higher speed used during peak hours allows for efficient operation. A minimum number of flat steps required as a function of escalator speed was developed to ensure safety for the elderly.

  16. Contrast-enhanced ultrasonographic findings of serum amyloid A-positive hepatocellular neoplasm: Does hepatocellular adenoma arise in cirrhotic liver?

    PubMed Central

    Kumagawa, Mariko; Matsumoto, Naoki; Watanabe, Yukinobu; Hirayama, Midori; Miura, Takao; Nakagawara, Hiroshi; Ogawa, Masahiro; Matsuoka, Shunichi; Moriyama, Mitsuhiko; Takayama, Tadatoshi; Sugitani, Masahiko

    2016-01-01

    Hepatocellular adenoma (HCA) was recently classified into four pathological subtypes. There have been few studies describing the findings of contrast-enhanced ultrasonography (CEUS) of each type. Our case concerns a 78-year-old man who had undergone routine medical check-ups for hepatitis C for 11 years. Abdominal ultrasonography showed a 28 mm, hypo-echoic mass in the segment 4 of the liver. His integrating amount of drinking was 670 kg convert into ethanol. CEUS with Sonazoid demonstrated mild uniform hypo-enhancement with inflow of microbubbles from the periphery of the tumor in the arterial phase, and heterogeneously hypo-enhancement in the post vascular phase. Because the mass increased in size within 3 mo, a well differentiated hepatocellular carcinoma was suspected, and hepatic resection was performed. Microscopic findings showed homogeneous cell proliferation with low grade atypia, infiltration of inflammatory cells, ductular reactions, fatty deposit in part, and sinusoidal dilation. Immunohistochemistry revealed geographic positive for serum amyloid A (SAA), focal positive for glutamine synthetase, diffuse and strong positive for C-reactive protein, and positive for liver-type fatty acid binding protein. These pathological features corresponded to that of an inflammatory HCA. However, we could not make a clear diagnosis, because HCAs were defined as not to arise in cirrhotic liver. Finally, this tumor was diagnosed as a SAA positive hepatocellular neoplasm. PMID:27660679

  17. [Cutaneous angiosarcoma arising after radiotherapy treatment of a breast carcinoma. Description of a case and review of the literature].

    PubMed

    Di Tommaso, L; Fabbri, A

    2003-08-01

    Cutaneous angiosarcomas occurring as a complication of radiation therapy for breast cancer are rare. To the best of our knowledge 37 cases have been reported in English literature during the last two decades. We describe a case of angiosarcoma arising in the skin of a breast previously irradiated for breast carcinoma. The patient, a 74-year-old woman, had been treated with conservative surgery and radiotherapy for a pT1N0 infiltrating ductal carcinoma of the left breast in 1993. Nine years later a skin lesion, which was interpreted as a recurrence, arose in the same site. A biopsy obtained from the lesion, and initially considered to be negative for cancer, showed istological features consistent with those of the atypical vascular lesion. Seven months later the same lesion transformed in a 5 x 3 reddish mass which at histological examination was diagnosed as an high grad post-irradiation angiosarcoma of the skin of the breast. Data on previously reported post iradiation angiosarcoma of the breast are reviewed; further consideration on differential diagnosis between those lesions and atypical vascular lesions are presented.

  18. Contrast-enhanced ultrasonographic findings of serum amyloid A-positive hepatocellular neoplasm: Does hepatocellular adenoma arise in cirrhotic liver?

    PubMed

    Kumagawa, Mariko; Matsumoto, Naoki; Watanabe, Yukinobu; Hirayama, Midori; Miura, Takao; Nakagawara, Hiroshi; Ogawa, Masahiro; Matsuoka, Shunichi; Moriyama, Mitsuhiko; Takayama, Tadatoshi; Sugitani, Masahiko

    2016-09-18

    Hepatocellular adenoma (HCA) was recently classified into four pathological subtypes. There have been few studies describing the findings of contrast-enhanced ultrasonography (CEUS) of each type. Our case concerns a 78-year-old man who had undergone routine medical check-ups for hepatitis C for 11 years. Abdominal ultrasonography showed a 28 mm, hypo-echoic mass in the segment 4 of the liver. His integrating amount of drinking was 670 kg convert into ethanol. CEUS with Sonazoid demonstrated mild uniform hypo-enhancement with inflow of microbubbles from the periphery of the tumor in the arterial phase, and heterogeneously hypo-enhancement in the post vascular phase. Because the mass increased in size within 3 mo, a well differentiated hepatocellular carcinoma was suspected, and hepatic resection was performed. Microscopic findings showed homogeneous cell proliferation with low grade atypia, infiltration of inflammatory cells, ductular reactions, fatty deposit in part, and sinusoidal dilation. Immunohistochemistry revealed geographic positive for serum amyloid A (SAA), focal positive for glutamine synthetase, diffuse and strong positive for C-reactive protein, and positive for liver-type fatty acid binding protein. These pathological features corresponded to that of an inflammatory HCA. However, we could not make a clear diagnosis, because HCAs were defined as not to arise in cirrhotic liver. Finally, this tumor was diagnosed as a SAA positive hepatocellular neoplasm. PMID:27660679

  19. Contrast-enhanced ultrasonographic findings of serum amyloid A-positive hepatocellular neoplasm: Does hepatocellular adenoma arise in cirrhotic liver?

    PubMed

    Kumagawa, Mariko; Matsumoto, Naoki; Watanabe, Yukinobu; Hirayama, Midori; Miura, Takao; Nakagawara, Hiroshi; Ogawa, Masahiro; Matsuoka, Shunichi; Moriyama, Mitsuhiko; Takayama, Tadatoshi; Sugitani, Masahiko

    2016-09-18

    Hepatocellular adenoma (HCA) was recently classified into four pathological subtypes. There have been few studies describing the findings of contrast-enhanced ultrasonography (CEUS) of each type. Our case concerns a 78-year-old man who had undergone routine medical check-ups for hepatitis C for 11 years. Abdominal ultrasonography showed a 28 mm, hypo-echoic mass in the segment 4 of the liver. His integrating amount of drinking was 670 kg convert into ethanol. CEUS with Sonazoid demonstrated mild uniform hypo-enhancement with inflow of microbubbles from the periphery of the tumor in the arterial phase, and heterogeneously hypo-enhancement in the post vascular phase. Because the mass increased in size within 3 mo, a well differentiated hepatocellular carcinoma was suspected, and hepatic resection was performed. Microscopic findings showed homogeneous cell proliferation with low grade atypia, infiltration of inflammatory cells, ductular reactions, fatty deposit in part, and sinusoidal dilation. Immunohistochemistry revealed geographic positive for serum amyloid A (SAA), focal positive for glutamine synthetase, diffuse and strong positive for C-reactive protein, and positive for liver-type fatty acid binding protein. These pathological features corresponded to that of an inflammatory HCA. However, we could not make a clear diagnosis, because HCAs were defined as not to arise in cirrhotic liver. Finally, this tumor was diagnosed as a SAA positive hepatocellular neoplasm.

  20. Coexistence of unlimited bipartite and genuine multipartite entanglement: Promiscuous quantum correlations arising from discrete to continuous-variable systems

    SciTech Connect

    Adesso, Gerardo; Ericsson, Marie; Illuminati, Fabrizio

    2007-08-15

    Quantum mechanics imposes 'monogamy' constraints on the sharing of entanglement. We show that, despite these limitations, entanglement can be fully 'promiscuous', i.e., simultaneously present in unlimited two-body and many-body forms in states living in an infinite-dimensional Hilbert space. Monogamy just bounds the divergence rate of the various entanglement contributions. This is demonstrated in simple families of N-mode (N{>=}4) Gaussian states of light fields or atomic ensembles, which therefore enable infinitely more freedom in the distribution of information, as opposed to systems of individual qubits. Such a finding is of importance for the quantification, understanding, and potential exploitation of shared quantum correlations in continuous variable systems. We discuss how promiscuity gradually arises when considering simple families of discrete variable states, with increasing Hilbert space dimension towards the continuous variable limit. Such models are somehow analogous to Gaussian states with asymptotically diverging, but finite, squeezing. In this respect, we find that non-Gaussian states (which in general are more entangled than Gaussian states) exhibit also the interesting feature that their entanglement is more shareable: in the non-Gaussian multipartite arena, unlimited promiscuity can be already achieved among three entangled parties, while this is impossible for Gaussian, even infinitely squeezed states.