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Sample records for depletion width imaging

  1. Modeling of depletion width variation over time in thin film photovoltaics

    NASA Astrophysics Data System (ADS)

    Aldosari, Marouf; Grigoriu, Liliana; Sohrabpoor, Hamed; Gorji, Nima E.

    2016-02-01

    The performance degradation of a hybrid solar cell is modelled considering the variation of depletion width over time. The p-i-n structure of a TiO2/perovskite/HTL photovoltaic is investigated. Several different time-dependent approaches are compared and a new model is introduced based on the variation of defect density over time in depletion region. This phenomenon consequently manifests itself in the device degradation. Our approach leads to rather complicated time-dependent equation for the defect density which takes into account also the non-uniformity of electric field in the depletion region. The thickness of TiO2 nano layer is taken 50 nm and perovskite layer is 330 nm. The nanoscale thickness of TiO2 layer warrants the carrier transport through tunneling mechanism.

  2. Importance of Depletion Width on Charge Transport and Interfacial Recombination in Extremely Thin Absorber Solar Cells

    NASA Astrophysics Data System (ADS)

    Edley, Michael; Jones, Treavor; Baxter, Jason

    The dynamics of charge carrier transport and recombination and their dependence on physical and electrochemical length scales in extremely thin absorber (ETA) solar cells is vital to cell design. We used J-V characterization, transient photocurrent / photovoltage, and electrochemical impedance spectroscopy to study electron transport and interfacial recombination in ETA cell. ETA cells were composed of ZnO nanowires coated with an ultrathin (5 nm) CdS buffer layer and CdSe absorbers with thicknesses of 10 - 40 nm, with polysulfide electrolyte. In thinner absorbers near short circuit, the depletion region can extend radially into the nanowire, inhibiting interfacial recombination rate. However, depleting the periphery of the nanowire reduces the cross sectional area for charge transport, resulting in longer characteristic collection times. Thicker absorbers suffered more significant bias-dependent collection, and we conclude that slight radial penetration of the depletion region into the nanowires enhances charge collection. This work highlights the importance of considering the impact of depletion width on charge transport and interfacial recombination in the design of liquid junction, semiconductor-sensitized solar cells.

  3. Subdiffraction, Luminescence-Depletion Imaging of Isolated, Giant, CdSe/CdS Nanocrystal Quantum Dots

    SciTech Connect

    Lesoine, Michael D.; Bhattacharjee, Ujjal; Guo, Yijun; Vela, Javier; Petrich, Jacob W.; Smith, Emily A.

    2013-01-18

    Subdiffraction spatial resolution luminescence depletion imaging was performed with giant CdSe/14CdS nanocrystal quantum dots (g-NQDs) dispersed on a glass slide. Luminescence depletion imaging used a Gaussian shaped excitation laser pulse overlapped with a depletion pulse, shaped into a doughnut profile, with zero intensity in the center. Luminescence from a subdiffraction volume is collected from the central portion of the excitation spot, where no depletion takes place. Up to 92% depletion of the luminescence signal was achieved. An average full width at half-maximum of 40 ± 10 nm was measured in the lateral direction for isolated g-NQDs at an air interface using luminescence depletion imaging, whereas the average full width at half-maximum was 450 ± 90 nm using diffraction-limited, confocal luminescence imaging. Time-gating of the luminescence depletion data was required to achieve the stated spatial resolution. No observable photobleaching of the g-NQDs was present in the measurements, which allowed imaging with a dwell time of 250 ms per pixel to obtain images with a high signal-to-noise ratio. The mechanism for luminescence depletion is likely stimulated emission, stimulated absorption, or a combination of the two. The g-NQDs fulfill a need for versatile, photostable tags for subdiffraction imaging schemes where high laser powers or long exposure times are used.

  4. Imaging neurotransmitter uptake and depletion in astrocytes

    SciTech Connect

    Tan, W. |; Haydon, P.G.; Yeung, E.S.

    1997-08-01

    An ultraviolet (UV) laser-based optical microscope and charge-coupled device (CCD) detection system was used to obtain chemical images of biological cells. Subcellular structures can be easily seen in both optical and fluorescence images. Laser-induced native fluorescence detection provides high sensitivity and low limits of detection, and it does not require coupling to fluorescent dyes. We were able to quantitatively monitor serotonin that has been taken up into and released from individual astrocytes on the basis of its native fluorescence. Different regions of the cells took up different amounts of serotonin with a variety of uptake kinetics. Similarly, we observed different serotonin depletion dynamics in different astrocyte regions. There were also some astrocyte areas where no serotonin uptake or depletion was observed. Potential applications include the mapping of other biogenic species in cells as well as the ability to image their release from specific regions of cells in response to external stimuli. {copyright} {ital 1997} {ital Society for Applied Spectroscopy}

  5. Autoionization widths by Stieltjes imaging applied to Lanczos pseudospectra

    SciTech Connect

    Kopelke, S.; Gokhberg, K.; Cederbaum, L. S.; Tarantelli, F.; Averbukh, V.

    2011-01-14

    Excited states of atoms and molecules lying above the ionization threshold can decay by electron emission in a process commonly known as autoionization. The autoionization widths can be calculated conveniently using Fano formalism and discretized atomic and molecular spectra by a standard procedure referred to as Stieltjes imaging. The Stieltjes imaging procedure requires the use of the full discretized spectrum of the final states of the autoionization, making its use for poly-atomic systems described by high-quality basis sets impractical. Following our previous work on photoionization cross-sections, here we show that also in the case of autoionization widths, the full diagonalization bottleneck can be overcome by the use of Lanczos pseudospectra. We test the proposed method by calculating the well-documented autoionization widths of inner-valence-excited neon and apply the new technique to autoionizing states of hydrofluoric acid and benzene.

  6. Beam Width Robustness of a 670 GHz Imaging Radar

    NASA Technical Reports Server (NTRS)

    Cooper, K. B.; Llombart, N.; Dengler, R. J.; Siegel, P. H.

    2009-01-01

    Detection of a replica bomb belt concealed on a mannequin at 4 m standoff range is achieved using a 670 GHz imaging radar. At a somewhat larger standoff range of 4.6 m, the radar's beam width increases substantially, but the through-shirt image quality remains good. This suggests that a relatively modest increase in aperture size over the current design will be sufficient to detect person-borne concealed weapons at ranges exceeding 25 meters.

  7. Beam Width Robustness of a 670 GHz Imaging Radar

    NASA Technical Reports Server (NTRS)

    Cooper, K. B.; Llombart, N.; Dengler, R. J.; Siegel, P. H.

    2009-01-01

    Detection of a replica bomb belt concealed on a mannequin at 4 m standoff range is achieved using a 670 GHz imaging radar. At a somewhat larger standoff range of 4.6 m, the radar's beam width increases substantially, but the through-shirt image quality remains good. This suggests that a relatively modest increase in aperture size over the current design will be sufficient to detect person-borne concealed weapons at ranges exceeding 25 meters.

  8. Supercontinuum Stimulated Emission Depletion Fluorescence Lifetime Imaging

    SciTech Connect

    Lesoine, Michael; Bose, Sayantan; Petrich, Jacob; Smith, Emily

    2012-06-13

    Supercontinuum (SC) stimulated emission depletion (STED) fluorescence lifetime imaging is demonstrated by using time-correlated single-photon counting (TCSPC) detection. The spatial resolution of the developed STED instrument was measured by imaging monodispersed 40-nm fluorescent beads and then determining their fwhm, and was 36 ± 9 and 40 ± 10 nm in the X and Y coordinates, respectively. The same beads measured by confocal microscopy were 450 ± 50 and 430 ± 30 nm, which is larger than the diffraction limit of light due to underfilling the microscope objective. Underfilling the objective and time gating the signal were necessary to achieve the stated STED spatial resolution. The same fluorescence lifetime (2.0 ± 0.1 ns) was measured for the fluorescent beads by using confocal or STED lifetime imaging. The instrument has been applied to study Alexa Fluor 594-phalloidin labeled F-actin-rich projections with dimensions smaller than the diffraction limit of light in cultured cells. Fluorescence lifetimes of the actin-rich projections range from 2.2 to 2.9 ns as measured by STED lifetime imaging.

  9. Determination of Acceptor Concentration, Depletion Width, Donor Level Movement and Sensitivity Factor of ZnO on Diamond Heterojunction under UV Illumination

    PubMed Central

    Saw, Kim Guan; Tneh, Sau Siong; Yam, Fong Kwong; Ng, Sha Shiong; Hassan, Zainuriah

    2014-01-01

    The concentration of acceptor carriers, depletion width, magnitude of donor level movement as well as the sensitivity factor are determined from the UV response of a heterojunction consisting of ZnO on type IIb diamond. From the comparison of the I-V measurements in dark condition and under UV illumination we show that the acceptor concentration (∼1017 cm−3) can be estimated from p-n junction properties. The depletion width of the heterojunction is calculated and is shown to extend farther into the ZnO region in dark condition. Under UV illumination, the depletion width shrinks but penetrates both materials equally. The ultraviolet illumination causes the donor level to move closer to the conduction band by about 50 meV suggesting that band bending is reduced to allow more electrons to flow from the intrinsically n-type ZnO. The sensitivity factor of the device calculated from the change of threshold voltages, the ratio of dark and photocurrents and identity factor is consistent with experimental data. PMID:24586707

  10. Fully depleted and backside biased monolithic CMOS image sensor

    NASA Astrophysics Data System (ADS)

    Stefanov, Konstantin D.; Clarke, Andrew S.; Holland, Andrew D.

    2016-07-01

    We are presenting a novel concept for a fully depleted, monolithic, pinned photodiode CMOS image sensor using reverse substrate bias. The principle of operation allows the manufacture of backside illuminated CMOS sensors with active thickness in excess of 100 μm. This helps increase the QE at near-IR and soft X-ray wavelengths, while preserving the excellent characteristics associated with the pinned photodiode sensitive elements. Such sensors are relevant to a wide range of applications, including scientific imaging, astronomy, Earth observation and surveillance. A prototype device with 10 μm and 5.4 μm pixels using this concept has been designed and is being manufactured on a 0.18 μm CMOS image sensor process. Only one additional implantation step has been introduced to the normal manufacturing flow to make this device. The paper discusses the design of the sensor and the challenges that had to be overcome to realise it in practice, and in particular the method of achieving full depletion without parasitic substrate currents. It is expected that this new technology can be competitive with modern backside illuminated thick CCDs for use at visible to near-IR telescopes and synchrotron light sources.

  11. Depth resolution improvement of streak tube imaging lidar using optimal signal width

    NASA Astrophysics Data System (ADS)

    Ye, Guangchao; Fan, Rongwei; Lu, Wei; Dong, Zhiwei; Li, Xudong; He, Ping; Chen, Deying

    2016-10-01

    Streak tube imaging lidar (STIL) is an active imaging system that has a high depth resolution with the use of a pulsed laser transmitter and streak tube receiver to produce three-dimensional (3-D) range images. This work investigates the optimal signal width of the lidar system, which is helpful to improve the depth resolution based on the centroid algorithm. Theoretical analysis indicates that the signal width has a significant effect on the depth resolution and the optimal signal width can be determined for a given STIL system, which is verified by both the simulation and experimental results. An indoor experiment with a planar target was carried out to validate the relation that the range error decreases first and then increases with the signal width, resulting in an optimal signal width of 8.6 pixels. Finer 3-D range images of a cartoon model were acquired by using the optimal signal width and a minimum range error of 5.5 mm was achieved in a daylight environment.

  12. Hybrid pn-junction solar cells based on layers of inorganic nanocrystals and organic semiconductors: optimization of layer thickness by considering the width of the depletion region.

    PubMed

    Saha, Sudip K; Guchhait, Asim; Pal, Amlan J

    2014-03-07

    We report the formation and characterization of hybrid pn-junction solar cells based on a layer of copper diffused silver indium disulfide (AgInS2@Cu) nanoparticles and another layer of copper phthalocyanine (CuPc) molecules. With copper diffusion in the nanocrystals, their optical absorption and hence the activity of the hybrid pn-junction solar cells was extended towards the near-IR region. To decrease the particle-to-particle separation for improved carrier transport through the inorganic layer, we replaced the long-chain ligands of copper-diffused nanocrystals in each monolayer with short-ones. Under illumination, the hybrid pn-junctions yielded a higher short-circuit current as compared to the combined contribution of the Schottky junctions based on the components. A wider depletion region at the interface between the two active layers in the pn-junction device as compared to that of the Schottky junctions has been considered to analyze the results. Capacitance-voltage characteristics under a dark condition supported such a hypothesis. We also determined the width of the depletion region in the two layers separately so that a pn-junction could be formed with a tailored thickness of the two materials. Such a "fully-depleted" device resulted in an improved photovoltaic performance, primarily due to lessening of the internal resistance of the hybrid pn-junction solar cells.

  13. Measurement of magnetic domain wall width using energy-filtered Fresnel images.

    PubMed

    Lloyd, S J; Loudon, J C; Midgley, P A

    2002-08-01

    Magnetic domain walls in Nd2Fe14B have been examined using a series of energy-filtered Fresnel images in the field emission gun transmission electron microscope (FEGTEM). We describe the changes in the intensity distribution of the convergent wall image as a function of defocus, foil thickness and domain wall width. The effect of tilted domain walls and beam convergence on the fringe pattern is also discussed. A comparison of the experimental intensity profile with that from simulations allows the domain wall width to be determined. Measurement of very narrow walls is made possible only by using a relatively thick foil, which necessitates energy-filtering to allow quantitative comparison with simulations. The magnetic domain wall width in Nd2Fe14B was found to be 3 +/- 2 nm.

  14. Pulse-width considerations for nonlinear Raman brain imaging: whither the optimum?

    NASA Astrophysics Data System (ADS)

    Lanin, A. A.; Stepanov, E. A.; Tikhonov, R. A.; Sidorov-Biryukov, D. A.; Fedotov, A. B.; Zheltikov, A. M.

    2015-11-01

    We propose simple, yet efficient strategies of pulse-width optimization applicable for nonlinear Raman brain imaging. With the spectral bandwidth of laser pulses accurately matched against the bandwidth of molecular vibrations, the coherent Raman signal is shown to be radically enhanced, enabling higher sensitivities and higher frame rates in nonlinear Raman brain imaging. As a specific example, we show that subpicosecond pulses offer a powerful tool for the detection of brain tumors using stimulated Raman microscopy, as they provide a strong signal without compromising the molecular specificity.

  15. Radio-Tomographic Images of Post-midnight Equatorial Plasma Depletions

    NASA Astrophysics Data System (ADS)

    Hei, M. A.; Bernhardt, P. A.; Siefring, C. L.; Wilkens, M.; Huba, J. D.; Krall, J.; Valladares, C. E.; Heelis, R. A.; Hairston, M. R.; Coley, W. R.; Chau, J. L.

    2013-12-01

    For the first time, post-midnight equatorial plasma depletions (EPDs) have been imaged in the longitude-altitude plane using radio-tomography. High-resolution (~10 km × 10 km) electron-density reconstructions were created from total electron content (TEC) data using an array of receivers sited in Peru and the Multiplicative Algebraic Reconstruction Technique (MART) inversion algorithm. TEC data were obtained from the 150 and 400 MHz signals transmitted by the CERTO beacon on the C/NOFS satellite. In-situ electron density data from the C/NOFS CINDI instrument and electron density profiles from the UML Jicamarca ionosonde were used to generate an initial guess for the MART inversion, and also to constrain the inversion process. Observed EPDs had widths of 100-1000 km, spacings of 300-900 km, and often appeared 'pinched off' at the bottom. Well-developed EPDs appeared on an evening with a very small (4 m/s) Pre-Reversal-Enhancement (PRE), suggesting that postmidnight enhancements of the vertical plasma drift and/or seeding-induced uplifts (e.g. gravity waves) were responsible for driving the Rayleigh-Taylor Instability into the nonlinear regime on this night. On another night the Jicamarca ISR recorded postmidnight (~0230 LT) Eastward electric fields nearly twice as strong as the PRE fields seven hours earlier. These electric fields lifted the whole ionosphere, including embedded EPDs, over a longitude range ~14° wide. CINDI detected a dawn depletion in exactly the area where the reconstruction showed an uplifted EPD. Strong Equatorial Spread-F observed by the Jicamarca ionosonde during receiver observation times confirmed the presence of ionospheric irregularities.

  16. ESR line width and line shape dependence of Overhauser-enhanced magnetic resonance imaging.

    PubMed

    Meenakumari, V; Utsumi, Hideo; Jawahar, A; Milton Franklin Benial, A

    2016-11-01

    Electron spin resonance and Overhauser-enhanced magnetic resonance imaging studies were carried out for various concentrations of (14) N-labeled 3-carbamoyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl in pure water. Overhauser-enhancement factor attains maxima in the range of 2.5-3 mm concentration. The leakage factor showed an asymptotic increase with increasing agent concentration. The coupling parameter showed the interaction between the electron and nuclear spins to be mainly dipolar in origin. The electron spin resonance parameters, such as the line width, line shape and g-factor, were determined. The line width analysis confirms that the line broadening is proportional to the agent concentration, and also the agent concentration is optimized in the range of 2.5-3 mm. The line shape analysis shows that the observed electron spin resonance line shape is a Voigt line shape, in which the Lorentzian component is dominant. The contribution of Lorentzian component was estimated using the winsim package. The Lorentzian component of the resonance line attains maxima in the range of 2.5-3 mm concentration. Therefore, this study reveals that the agent concentration, line width and Lorentzian component are the important factors in determining the Overhauser-enhancement factor. Hence, the agent concentration was optimized as 2.5-3 mm for in vivo/in vitro electron spin resonance imaging and Overhauser-enhanced magnetic resonance imaging phantom studies. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  17. The impact of the width of the tracking area on speckle tracking parameters-methodological aspects of deformation imaging.

    PubMed

    Stoebe, Stephan; Tarr, Adrienn; Pfeiffer, Dietrich; Hagendorff, Andreas

    2014-05-01

    The aim of this study was to analyze the impact of the tracking area width on myocardial wall motion and deformation parameters in 2D speckle tracking. Standardized apical views were acquired in 30 healthy subjects and 15 patients with left ventricular systolic dysfunction using 2D echocardiography. Longitudinal peak systolic strain (PSS), longitudinal peak systolic strain rate (PSSR), postsystolic index (PSI), peak longitudinal (PLD), and peak transverse displacement (PTD) were determined by 2D speckle tracking to analyze the impact of the tracking area width on global and regional myocardial wall motion and deformation parameters. The dimension of the tracking area has a significant impact on all parameters. With increasing width of the tracking area higher values of PSS, PSSR, PSI, and lower values of PLD and PTD were determined. With increasing width of the tracking area a significant number of segments were not tracked. In summary, especially global PSS is significantly influenced by the width of the tracking area. The strain values determined by 2D speckle tracking are significantly influenced by the tracking area width. The tracking of the subendocardial layers only results in lower global strain values than tracking the complete ventricular wall using the medium or wide tracking area widths. The tracking quality in the far field is worse if the tracking area is too wide. The present data show that standard and reference values of deformation imaging should include detailed information about the position and the width of the tracking area. © 2013, Wiley Periodicals, Inc.

  18. What is the minimum river width for the estimation of water clarity using medium-resolution remote sensing images?

    NASA Astrophysics Data System (ADS)

    Zhao, Dehua; Lv, Meiting; Zou, Xiangxu; Wang, Penghe; Yang, Tangwu; An, Shuqing

    2014-05-01

    Numerous studies have demonstrated the feasibility of remotely sensing water clarity of lakes, reservoirs, and larger rivers using medium-resolution spatial images. However, addressing relatively small rivers or river sections is very challenging due to the adjacency effect from the riverbanks. The objectives of this study are to quantify the minimum river width for water quality remote sensing and to validate the feasibility of using medium-resolution spatial images for estimating the Secchi disk depth (SDD). A methodology was developed to quantify the minimum river width for water quality remote sensing using high-resolution spatial images from WorldView-2 and Pléiades. Our results suggest that the influential distance of the adjacency effect from the riverbank is 17.3 m, i.e., water pixels with a distance of more than 17.3 m from the shoreline experienced a minimal disturbance from the riverbank. For the 30 m spatial resolution HJ-1A image (one of Chinese civilian satellites launched in 2008), the minimum river width is 64.6-98.5 m (the variation was determined according to the river flow direction and the pixel position relative to the shoreline). Using the sections that satisfied the minimum river width requirement, a significant estimation model was established between the spectral reflectance and the SDD (R2 = 0.94), demonstrating that the minimum river width recommended in this study is practical. This work is the first study to quantify the minimum river width for water quality remote sensing and thus provides a valuable reference for remote sensing of relatively small rivers.

  19. Depletion of New Neurons by Image Guided Irradiation

    PubMed Central

    Tan, Y.-F.; Rosenzweig, S.; Jaffray, D.; Wojtowicz, J. M.

    2011-01-01

    Ionizing radiation continues to be a relevant tool in both imaging and the treatment of cancer. Experimental uses of focal irradiation have recently been expanded to studies of new neurons in the adult brain. Such studies have shown cognitive deficits following radiation treatment and raised caution as to possible unintentional effects that may occur in humans. Conflicting outcomes of the effects of irradiation on adult neurogenesis suggest that the effects are either transient or permanent. In this study, we used an irradiation apparatus employed in the treatment of human tumors to assess radiation effects on rat neurogenesis. For subjects we used adult male rats (Sprague-Dawley) under anesthesia. The irradiation beam was directed at the hippocampus, a center for learning and memory, and the site of neurogenic activity in adult brain. The irradiation was applied at a dose-rate 0.6 Gy/min for total single-fraction, doses ranging from 0.5 to 10.0 Gy. The animals were returned to home cages and recovered with no sign of any side effects. The neurogenesis was measured either 1 week or 6 weeks after the irradiation. At 1 week, the number of neuronal progenitors was reduced in a dose-dependent manner with the 50% reduction at 0.78 Gy. The dose–response curve was well fitted by a double exponential suggesting two processes. Examination of the tissue with quantitative immunohistochemistry revealed a dominant low-dose effect on neuronal progenitors resulting in 80% suppression of neurogenesis. This effect was partially reversible, possibly due to compensatory proliferation of the remaining precursors. At higher doses (>5 Gy) there was additional, nearly complete block of neurogenesis without compensatory proliferation. We conclude that notwithstanding the usefulness of irradiation for experimental purposes, the exposure of human subjects to doses often used in radiotherapy treatment could be damaging and cause cognitive impairments. PMID:21541259

  20. Automated Detection and Tracking of Equatorial Plasma Depletions Using Ground-Based Optical Imagers

    NASA Astrophysics Data System (ADS)

    Pedersen, T.; Carrano, C.; Griffin, J.

    2004-12-01

    Optical imaging is one of the few means available for determining space weather parameters simultaneously over large areas, but tropospheric cloud cover presents a significant barrier to operational use of data from ground-based optical instruments. Distributed sensors experiencing different tropospheric conditions but with overlapping fields of view in the upper atmosphere are one possible solution to the cloud cover difficulty, while intelligent processing of imager data to discriminate between clouds and upper atmospheric features is another potential means of providing reliable data output from only a single instrument. We evaluate and discuss a variety of processing algorithms developed or adapted for the purpose of detecting and tracking equatorial plasma depletions in all-sky imager data under realistic conditions including significant cloud cover. Our most successful technique thus far relies on discrimination between depletions and other image features based on their signatures in velocity and correlation space rather than physical coordinates. In addition to allowing identification and tracking of the depletions, accurate knowledge of the velocity allows multiple frames of image data to be processed coherently in the reference frame moving with the depletions. This processing can virtually eliminate cloud effects up to 50 percent cloud cover. With externally provided velocity information (such as from a spaced-antenna scintillation system, for example) or an improved velocity algorithm, useful data can be obtained at even greater cloud cover fractions. A similar motion-based technique can also be applied to the background star field, allowing stars to be easily distinguished from pixel noise and hot pixels for rapid automatic identification of image regions affected by clouds without the need to identify, locate, or track any specific stars.

  1. Poster — Thur Eve — 02: Measurement of CT radiation profile width using Fuji CR imaging plate raw data

    SciTech Connect

    Bjarnason, T A; Yang, C J

    2014-08-15

    Measuring the CT collimation width and assessing the shape of the overall profile is a relatively straightforward quality control (QC) measure that impacts both image quality and patient dose, and is often required at acceptance and routine testing. Most CT facilities have access to computed radiography (CR) systems, so performing CT collimation profile assessments using CR plates requires no additional equipment. Previous studies have shown how to effectively use CR plates to measure the radiation profile width. However, a major limitation of the previous work is that the full dynamic range of CR detector plates are not used, since the CR processing technology reduces the dynamic range of the DICOM output to 2{sup 10}, requiring the sensitivity and latitude settings of CR reader to be adjusted to prevent clipping of the CT profile data. Such adjustments to CR readers unnecessarily complicate the QC procedure. These clipping artefacts hinder the ability to accurately assess CT collimation width because the full-width at half maximum value of the penumbras are not properly determined if the maximum dose of the profile is not available. Furthermore, any inconsistencies in the radiation profile shape are lost if the profile plateau is clipped off. In this work we developed an opensource Matlab script for straightforward CT profile width measurements using raw CR data that also allows assessment of the profile shape without clipping, and applied this approach during CT QC.

  2. Stochastic optical reconstruction microscopy (STORM) in comparison with stimulated emission depletion (STED) and other imaging methods.

    PubMed

    Tam, Johnny; Merino, David

    2015-11-01

    Stochastic optical reconstruction microscopy (STORM) and stimulated emission depletion (STED) microscopy are two super-resolution optical microscopy approaches that have rapidly gained popularity in recent years. Both modalities offer super-resolution imaging capabilities with the potential for imaging in multiple colors, three-dimensions, and the possibility to image in live cells. In this review, we focus on the specific advantages and disadvantages of each technique in the context of each other. STORM has been reported to achieve higher spatial resolution when compared to STED, but a lengthy acquisition may be required. STED utilizes relatively higher laser intensities, but is able to generate a super-resolution image immediately after acquisition without the need for any additional data processing. Ultimately, the choice between STORM and STED will depend not only on the specific application, but also on the users' ability to understand and optimize the various parameters ranging from sample preparation to image acquisition, which determine the quality of the final image. Stochastic optical reconstruction microscopy (STORM) and stimulated emission depletion (STED) are two super-resolution microscopy approaches that have rapidly gained popularity in recent years. STORM is based on the precise localization of a large number of individual molecules that together form a super-resolved image (bottom), whereas STED is based on the scanning of two super-imposed light sources which together allow for a super-resolved spot on the sample to be imaged (top). We discuss the specific advantages and disadvantages of each technique and explain the various parameters that affect image quality, which should be taken into consideration when planning experiments. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  3. Imaging the interaction of atelectasis and overdistension in surfactant-depleted lungs.

    PubMed

    Cereda, Maurizio; Emami, Kiarash; Xin, Yi; Kadlecek, Stephen; Kuzma, Nicholas N; Mongkolwisetwara, Puttisarn; Profka, Harrilla; Pickup, Stephen; Ishii, Masaru; Kavanagh, Brian P; Deutschman, Clifford S; Rizi, Rahim R

    2013-02-01

    Atelectasis and surfactant depletion may contribute to greater distension-and thereby injury-of aerated lung regions; recruitment of atelectatic lung may protect these regions by attenuating such overdistension. However, the effects of atelectasis (and recruitment) on aerated airspaces remain elusive. We tested the hypothesis that during mechanical ventilation, surfactant depletion increases the dimensions of aerated airspaces and that lung recruitment reverses these changes. Prospective imaging study in an animal model. Research imaging facility. Twenty-seven healthy Sprague Dawley rats. Surfactant depletion was obtained by saline lavage in anesthetized, ventilated rats. Alveolar recruitment was accomplished using positive end-expiratory pressure and exogenous surfactant administration. Airspace dimensions were estimated by measuring the apparent diffusion coefficient of He, using diffusion-weighted hyperpolarized gas magnetic resonance imaging. Atelectasis was demonstrated using computerized tomography and by measuring oxygenation. Saline lavage increased atelectasis (increase in nonaerated tissue from 1.2% to 13.8% of imaged area, p < 0.001), and produced a concomitant increase in mean apparent diffusion coefficient (~33%, p < 0.001) vs. baseline; the heterogeneity of the computerized tomography signal and the variance of apparent diffusion coefficient were also increased. Application of positive end-expiratory pressure and surfactant reduced the mean apparent diffusion coefficient (~23%, p < 0.001), and its variance, in parallel to alveolar recruitment (i.e., less computerized tomography densities and heterogeneity, increased oxygenation). Overdistension of aerated lung occurs during atelectasis is detectable using clinically relevant magnetic resonance imaging technology, and could be a key factor in the generation of lung injury during mechanical ventilation. Lung recruitment by higher positive end-expiratory pressure and surfactant administration reduces

  4. Imaging the Interaction of Atelectasis and Overdistention in Surfactant Depleted Lungs

    PubMed Central

    Cereda, Maurizio; Emami, Kiarash; Xin, Yi; Kadlecek, Stephen; Kuzma, Nicholas N.; Mongkolwisetwara, Puttisarn; Profka, Harrilla; Pickup, Stephen; Ishii, Masaru; Kavanagh, Brian P.; Deutschman, Clifford S.; Rizi, Rahim R.

    2012-01-01

    Objective Atelectasis and surfactant depletion may contribute to greater distension – and thereby injury – of aerated lung regions; recruitment of atelectatic lung may protect these regions by attenuating such overdistension. However, the effects of atelectasis (and recruitment) on aerated airspaces remain elusive. We tested the hypothesis that during mechanical ventilation, surfactant depletion increases the dimensions of aerated airspaces and that lung recruitment reverses these changes. Design Prospective imaging study in an animal model. Setting Research imaging facility Subjects 27 healthy Sprague Dawley rats Interventions Surfactant depletion was obtained by saline lavage in anesthetized, ventilated rats. Alveolar recruitment was accomplished using positive end-expiratory pressure (PEEP) and exogenous surfactant administration. Measurements and Main Results Airspace dimensions were estimated by measuring the apparent diffusion coefficient (ADC) of 3He, using diffusion-weighted hyperpolarized gas magnetic resonance imaging (MRI). Atelectasis was demonstrated using computerized tomography (CT) and by measuring oxygenation. Saline lavage increased atelectasis (increase in non-aerated tissue from 1.2 to 13.8% of imaged area, P<0.001), and produced a concomitant increase in mean ADC (~33%, P<0.001) vs. baseline; the heterogeneity of the CT signal and the variance of ADC were also increased. Application of PEEP and surfactant reduced the mean ADC (~23%, P<0.001), and its variance, in parallel to alveolar recruitment (i.e. less CT densities and heterogeneity, increased oxygenation). Conclusions Overdistension of aerated lung occurs during atelectasis, is detectable using clinically relevant MRI technology, and could be a key factor in the generation of lung injury during mechanical ventilation. Lung recruitment by higher PEEP and surfactant administration reduces airspace distension. PMID:23263577

  5. Multi-images deconvolution improves signal-to-noise ratio on gated stimulated emission depletion microscopy

    SciTech Connect

    Castello, Marco; Diaspro, Alberto; Vicidomini, Giuseppe

    2014-12-08

    Time-gated detection, namely, only collecting the fluorescence photons after a time-delay from the excitation events, reduces complexity, cost, and illumination intensity of a stimulated emission depletion (STED) microscope. In the gated continuous-wave- (CW-) STED implementation, the spatial resolution improves with increased time-delay, but the signal-to-noise ratio (SNR) reduces. Thus, in sub-optimal conditions, such as a low photon-budget regime, the SNR reduction can cancel-out the expected gain in resolution. Here, we propose a method which does not discard photons, but instead collects all the photons in different time-gates and recombines them through a multi-image deconvolution. Our results, obtained on simulated and experimental data, show that the SNR of the restored image improves relative to the gated image, thereby improving the effective resolution.

  6. Magnetic Resonance Imaging in Nondependent Pacemaker Patients with Pacemakers and Defibrillators with a Nearly Depleted Battery.

    PubMed

    Okamura, Hideo; Padmanabhan, Deepak; Watson, Robert E; Dalzell, Connie; Acker, Nancy; Jondal, Mary; Romme, Abby L; Cha, Yong-Mei; Asirvatham, Samuel J; Felmlee, Joel P; Friedman, Paul A

    2017-05-01

    Magnetic resonance imaging (MRI) in patients with non-MRI-conditional cardiac implantable electronic devices (CIEDs) has been shown to be safe when performed under closely monitored protocols. However, the safety of MRI in patients with devices with a nearly depleted battery has not been reported. Prospective data were collected between January 2008 and May 2015 in patients with non-MRI-conditional CIEDs undergoing clinically indicated MRI under institutional protocol. Patients who were pacemaker dependent were excluded. Patients whose devices were at elective replacement indicator (ERI) at the time of MRI or close to ERI (ERI or replacement for battery depletion within 3 months of scan) were identified through database review and analyzed for clinical events. MRI scans (n = 569) were performed in 442 patients. Of these, we identified 13 scans performed with a nearly depleted battery in nine patients. All scans with implantable cardioverter defibrillators (ICDs, n = 9) were uneventful. However, two scans with pacemakers close to ERI resulted in a power-on-reset (PoR) event. One scan with a pacemaker close to ERI that was programmed to DOO mode reached ERI during MRI and automatically changed to VVI mode. Additionally, one scan with a pacemaker at ERI did not allow programming. All pacemakers with events were implanted before 2005. Patients with pacemakers and ICDs with a nearly depleted battery can safely undergo MRI when patients are not pacemaker dependent. Attention should be paid because old devices can result in PoR or ERI during MRI, which may lead to oversensing and inhibition of pacing. © 2017 Wiley Periodicals, Inc.

  7. Method for Assessment of Changes in the Width of Cracks in Cement Composites with Use of Computer Image Processing and Analysis

    NASA Astrophysics Data System (ADS)

    Tomczak, Kamil; Jakubowski, Jacek; Fiołek, Przemysław

    2017-06-01

    Crack width measurement is an important element of research on the progress of self-healing cement composites. Due to the nature of this research, the method of measuring the width of cracks and their changes over time must meet specific requirements. The article presents a novel method of measuring crack width based on images from a scanner with an optical resolution of 6400 dpi, subject to initial image processing in the ImageJ development environment and further processing and analysis of results. After registering a series of images of the cracks at different times using SIFT conversion (Scale-Invariant Feature Transform), a dense network of line segments is created in all images, intersecting the cracks perpendicular to the local axes. Along these line segments, brightness profiles are extracted, which are the basis for determination of crack width. The distribution and rotation of the line of intersection in a regular layout, automation of transformations, management of images and profiles of brightness, and data analysis to determine the width of cracks and their changes over time are made automatically by own code in the ImageJ and VBA environment. The article describes the method, tests on its properties, sources of measurement uncertainty. It also presents an example of application of the method in research on autogenous self-healing of concrete, specifically the ability to reduce a sample crack width and its full closure within 28 days of the self-healing process.

  8. Methylene blue- and thiol-based oxygen depletion for super-resolution imaging.

    PubMed

    Schäfer, Philip; van de Linde, Sebastian; Lehmann, Julian; Sauer, Markus; Doose, Sören

    2013-03-19

    Anaerobic conditions are often required in solution-based bionanotechnological applications. Efficient oxygen depletion is essential for increasing photostability, optimizing fluorescence signals, and adjusting kinetics of fluorescence intermittency in single-molecule fluorescence spectroscopy/microscopy, particularly for super-resolution imaging techniques. We characterized methylene blue (MB)- and thiol-based redox reactions with the aim of designing an oxygen scavenger system as an alternative to the established enzyme-based oxygen scavenging systems or purging procedures. Redox reactions of the chromophore methylene blue in aqueous solution, commonly visualized in the blue bottle experiment, deplete molecular oxygen as long as a sacrificial reduction component is present in excess concentrations. We demonstrate that methylene blue in combination with reducing compounds such as β-mercaptoethylamine (MEA) can serve as fast and efficient oxygen scavenger. Efficient oxygen scavenging in aqueous solution is also possible with mere β-mercaptoethylamine at mM concentrations. We present kinetic parameters of the relevant reactions, pH-stability of the MB/MEA-oxygen scavenging system, and its application in single-molecule based super-resolution imaging.

  9. The Number of Accumulated Photons and the Quality of Stimulated Emission Depletion Lifetime Images

    SciTech Connect

    Syed, Aleem; Lesoine, Michael D; Bhattacharjee, Ujjal; Petrich, Jacob W; Smith, Emily A

    2014-03-03

    Time binning is used to increase the number of photon counts in the peak channel of stimulated emission depletion (STED) fluorescence lifetime decay curves to determine how it affects the resulting lifetime image. The fluorescence lifetime of the fluorophore, Alexa Fluor 594 phalloidin, bound to F-actin is probed in cultured S2 cells at a spatial resolution of ~40 nm. This corresponds to a tenfold smaller probe volume compared to confocal imaging, and a reduced number of photons contributing to the signal. Pixel-by-pixel fluorescence lifetime measurements and error analysis show that an average of 40 ± 30 photon counts in the peak channel with a signal-to-noise ratio of 20 is enough to calculate a reliable fluorescence lifetime from a single exponential fluorescence decay. No heterogeneity in the actin cytoskeleton in different regions of the cultured cells was measured in the 40- to 400-nm spatial regime.

  10. Assessment of severity of mitral regurgitation by measuring regurgitant jet width at its origin with transesophageal Doppler color flow imaging.

    PubMed

    Tribouilloy, C; Shen, W F; Quéré, J P; Rey, J L; Choquet, D; Dufossé, H; Lesbre, J P

    1992-04-01

    The ability of transesophageal color Doppler echocardiography to provide high-resolution images of both cardiac structure and blood flow in real time is advantageous for many clinical purposes. This study was performed to determine the utility of the regurgitant jet width at its origin measured by transesophageal Doppler color flow imaging in the assessment of severity of mitral regurgitation. Sixty-three consecutive patients with mitral regurgitation underwent transesophageal color Doppler examination, and the diameter of regurgitant jet at its origin was measured. Both right and left cardiac catheterizations were performed within 24 hours of Doppler studies, and angiographic grading of mitral regurgitation and regurgitant stroke volume were evaluated. There was a close relation between the jet diameter at its origin measured by transesophageal Doppler color flow imaging and the angiographic grade of mitral regurgitation (r = 0.86, p less than 0.001). A jet diameter of 5.5 mm or more identified severe mitral regurgitation (grade III or IV) with a sensitivity of 92%, specificity of 92%, and positive and negative predictive values of 88% and 95%, respectively. In 31 patients with isolated mitral regurgitation, the jet diameter correlated well with the regurgitant stroke volume determined by a combined hemodynamic-angiographic method (r = 0.85, p less than 0.001). A jet diameter of 5.5 mm or more identified a regurgitant stroke volume of 60 ml or more with a sensitivity of 88%, specificity of 93%, and positive and negative predictive values of 94% and 87%, respectively. The regurgitant jet width at its origin measured by transesophageal Doppler color flow imaging provides a simple and useful method of measuring the severity of mitral regurgitation, and it may allow differentiation between mild and severe mitral regurgitation.

  11. Lung volume assessments in normal and surfactant depleted lungs: agreement between bedside techniques and CT imaging.

    PubMed

    Albu, Gergely; Petak, Ferenc; Zand, Tristan; Hallbäck, Magnus; Wallin, Mats; Habre, Walid

    2014-01-01

    Bedside assessment of lung volume in clinical practice is crucial to adapt ventilation strategy. We compared bedside measures of lung volume by helium multiple-breath washout technique (EELVMBW,He) and effective lung volume based on capnodynamics (ELV) to those assessed from spiral chest CT scans (EELVCT) under different PEEP levels in control and surfactant-depleted lungs. Lung volume was assessed in anaesthetized mechanically ventilated rabbits successively by measuring i) ELV by analyzing CO2 elimination traces during the application of periods of 5 consecutive alterations in inspiratory/expiratory ratio (1:2 to 1.5:1), ii) measuring EELVMBW,He by using helium as a tracer gas, and iii) EELVCT from CT scan images by computing the normalized lung density. All measurements were performed at PEEP of 0, 3 and 9 cmH2O in random order under control condition and following surfactant depletion by whole lung lavage. Variables obtained with all techniques followed sensitively the lung volume changes with PEEP. Excellent correlation and close agreement was observed between EELVMBW,He and EELVCT (r = 0.93, p < 0.0001). ELV overestimated EELVMBW,He and EELVCT in normal lungs, whereas this difference was not evidenced following surfactant depletion. These findings resulted in somewhat diminished but still significant correlations between ELV and EELVCT (r = 0.58, p < 0.001) or EELVMBW,He (0.76, p < 0.001) and moderate agreements. Lung volume assessed with bedside techniques allow the monitoring of the changes in the lung aeration with PEEP both in normal lungs and in a model of acute lung injury. Under stable pulmonary haemodynamic condition, ELV allows continuous lung volume monitoring, whereas EELVMBW,He offers a more accurate estimation, but intermittently.

  12. Microanalytical X-ray imaging of depleted uranium speciation in environmentally aged munitions residues.

    PubMed

    Crean, Daniel E; Livens, Francis R; Stennett, Martin C; Grolimund, Daniel; Borca, Camelia N; Hyatt, Neil C

    2014-01-01

    Use of depleted uranium (DU) munitions has resulted in contamination of the near-surface environment with penetrator residues. Uncertainty in the long-term environmental fate of particles produced by impact of DU penetrators with hard targets is a specific concern. In this study DU particles produced in this way and exposed to the surface terrestrial environment for longer than 30 years at a U.K. firing range were characterized using synchrotron X-ray chemical imaging. Two sites were sampled: a surface soil and a disposal area for DU-contaminated wood, and the U speciation was different between the two areas. Surface soil particles showed little extent of alteration, with U speciated as oxides U3O7 and U3O8. Uranium oxidation state and crystalline phase mapping revealed these oxides occur as separate particles, reflecting heterogeneous formation conditions. Particles recovered from the disposal area were substantially weathered, and U(VI) phosphate phases such as meta-ankoleite (K(UO2)(PO4) · 3H2O) were dominant. Chemical imaging revealed domains of contrasting U oxidation state linked to the presence of both U3O7 and meta-ankoleite, indicating growth of a particle alteration layer. This study demonstrates that substantial alteration of DU residues can occur, which directly influences the health and environmental hazards posed by this contamination.

  13. Continuous-Wave Stimulated Emission Depletion Microscope for Imaging Actin Cytoskeleton in Fixed and Live Cells

    PubMed Central

    Neupane, Bhanu; Jin, Tao; Mellor, Liliana F.; Loboa, Elizabeth G.; Ligler, Frances S.; Wang, Gufeng

    2015-01-01

    Stimulated emission depletion (STED) microscopy provides a new opportunity to study fine sub-cellular structures and highly dynamic cellular processes, which are challenging to observe using conventional optical microscopy. Using actin as an example, we explored the feasibility of using a continuous wave (CW)-STED microscope to study the fine structure and dynamics in fixed and live cells. Actin plays an important role in cellular processes, whose functioning involves dynamic formation and reorganization of fine structures of actin filaments. Frequently used confocal fluorescence and STED microscopy dyes were employed to image fixed PC-12 cells (dyed with phalloidin- fluorescein isothiocyante) and live rat chondrosarcoma cells (RCS) transfected with actin-green fluorescent protein (GFP). Compared to conventional confocal fluorescence microscopy, CW-STED microscopy shows improved spatial resolution in both fixed and live cells. We were able to monitor cell morphology changes continuously; however, the number of repetitive analyses were limited primarily by the dyes used in these experiments and could be improved with the use of dyes less susceptible to photobleaching. In conclusion, CW-STED may disclose new information for biological systems with a proper characteristic length scale. The challenges of using CW-STED microscopy to study cell structures are discussed. PMID:26393614

  14. Semiautomatic segmentation of longitudinal computed tomography images in a rat model of lung injury by surfactant depletion

    PubMed Central

    Xin, Yi; Song, Gang; Kadlecek, Stephen; Hamedani, Hooman; Jiang, Yunqing; Rajaei, Jennia; Clapp, Justin; Profka, Harrilla; Meeder, Natalie; Wu, Jue; Tustison, Nicholas J.; Gee, James C.; Rizi, Rahim R.

    2014-01-01

    Quantitative analysis of computed tomography (CT) is essential to the study of acute lung injury. However, quantitative CT is made difficult by poor lung aeration, which complicates the critical step of image segmentation. To overcome this obstacle, this study sought to develop and validate a semiautomated, multilandmark, registration-based scheme for lung segmentation that is effective in conditions of poor aeration. Expiratory and inspiratory CT images were obtained in rats (n = 8) with surfactant depletion of incremental severity to mimic worsening aeration. Trained operators manually delineated the images to provide a comparative landmark. Semiautomatic segmentation originated from a single, previously segmented reference image obtained at healthy baseline. Deformable registration of the target images (after surfactant depletion) was performed using the symmetric diffeomorphic transformation model with B-spline regularization. Registration used multiple landmarks (i.e., rib cage, spine, and lung parenchyma) to minimize the effect of poor aeration. Then target images were automatically segmented by applying the calculated transformation function to the reference image contour. Semiautomatically and manually segmented contours proved to be highly similar in all aeration conditions, including those characterized by more severe surfactant depletion and expiration. The Dice similarity coefficient was over 0.9 in most conditions, confirming high agreement, irrespective of poor aeration. Furthermore, CT density-based measurements of gas volume, tissue mass, and lung aeration distribution were minimally affected by the method of segmentation. Moving forward, multilandmark registration has the potential to streamline quantitative CT analysis by enabling semiautomatic image segmentation of lungs with a broad range of injury severity. PMID:25640150

  15. Short-term repeatability of joint space width measurements using a magnetic resonance imaging compatible knee positioning device.

    PubMed

    Koff, M F; Stanley, D W; Weishaar, P J; Amrami, K K; Kaufman, K R

    2010-01-01

    The purpose of this study was to evaluate a magnetic resonance imaging (MRI) compatible knee positioning device to aid in minimizing intratechnologist and intertechnologist differences of minimum joint space width (JSW) measurements. Five subjects were scanned by two separate technologists, with and without an MRI-compatible positioning device. A semi-automated program calculated the minimum JSW of the tibiofemoral and patellofemoral joints. The scan-to-scan repeatability was evaluated from measurements between serial scans without subject repositioning, and the intratechnologist and intertechnologist repeatabilities were evaluated when the subject was removed from the magnet and repositioned by an individual technologist. The root mean square (RMS) error of the JSW measurements was also calculated. All measures of scan-to-scan repeatability and intratechnologist repeatability were unchanged with the MRI-compatible positioning device. The intertechnologist repeatability decreased from 0.70 to 0.42 mm, and the RMS error was significantly reduced (P = 0.0006) from 0.26 to 0.15 mm for the tibiofemoral joint. The variability of patellofemoral JSW measurements increased when using the positioning device; however, the increases were not statistically significant. The intertechnologist repeatability increased from 1.55 to 1.79 mm, and the RMS error increased from 0.58 to 0.73 mm. The MRI-compatible positioning device was successful at reducing JSW measurement variability at the tibiofemoral joint. The increase in measurement variability at the patellofemoral joint may be due to local incongruities of the articular surfaces. An MRI-compatible positioning device may be beneficial for quantitative longitudinal studies evaluating knee joint health.

  16. The radial width of a Coronal Mass Ejection between 0.1 and 0.4 AU estimated from the Heliospheric Imager on STEREO

    NASA Astrophysics Data System (ADS)

    Savani, N. P.; Rouillard, A. P.; Davies, J. A.; Owens, M. J.; Forsyth, R. J.; Davis, C. J.; Harrison, R. A.

    2009-11-01

    On 15-17 February 2008, a CME with an approximately circular cross section was tracked through successive images obtained by the Heliospheric Imager (HI) instrument onboard the STEREO-A spacecraft. Reasoning that an idealised flux rope is cylindrical in shape with a circular cross-section, best fit circles are used to determine the radial width of the CME. As part of the process the radial velocity and longitude of propagation are determined by fits to elongation-time maps as 252±5 km/s and 70±5° respectively. With the longitude known, the radial size is calculated from the images, taking projection effects into account. The radial width of the CME, S (AU), obeys a power law with heliocentric distance, R, as the CME travels between 0.1 and 0.4 AU, such that S=0.26 R0.6±0.1. The exponent value obtained is compared to published studies based on statistical surveys of in situ spacecraft observations of ICMEs between 0.3 and 1.0 AU, and general agreement is found. This paper demonstrates the new opportunities provided by HI to track the radial width of CMEs through the previously unobservable zone between the LASCO field of view and Helios in situ measurements.

  17. Comparing perceived auditory width to the visual image of a performing ensemble in contrasting bi-modal environmentsa)

    PubMed Central

    Valente, Daniel L.; Braasch, Jonas; Myrbeck, Shane A.

    2012-01-01

    Despite many studies investigating auditory spatial impressions in rooms, few have addressed the impact of simultaneous visual cues on localization and the perception of spaciousness. The current research presents an immersive audiovisual environment in which participants were instructed to make auditory width judgments in dynamic bi-modal settings. The results of these psychophysical tests suggest the importance of congruent audio visual presentation to the ecological interpretation of an auditory scene. Supporting data were accumulated in five rooms of ascending volumes and varying reverberation times. Participants were given an audiovisual matching test in which they were instructed to pan the auditory width of a performing ensemble to a varying set of audio and visual cues in rooms. Results show that both auditory and visual factors affect the collected responses and that the two sensory modalities coincide in distinct interactions. The greatest differences between the panned audio stimuli given a fixed visual width were found in the physical space with the largest volume and the greatest source distance. These results suggest, in this specific instance, a predominance of auditory cues in the spatial analysis of the bi-modal scene. PMID:22280585

  18. The mechanism of anti-CD20–mediated B cell depletion revealed by intravital imaging

    PubMed Central

    Montalvao, Fabricio; Garcia, Zacarias; Celli, Susanna; Breart, Béatrice; Deguine, Jacques; Van Rooijen, Nico; Bousso, Philippe

    2013-01-01

    Anti-CD20 Ab therapy has proven successful for treating B cell malignancies and a number of autoimmune diseases. However, how anti-CD20 Abs operate in vivo to mediate B cell depletion is not fully understood. In particular, the anatomical location, the type of effector cells, and the mechanism underlying anti-CD20 therapy remain uncertain. Here, we found that the liver is a major site for B cell depletion and that recirculation accounts for the decrease in B cell numbers observed in secondary lymphoid organs. Using intravital imaging, we established that, upon anti-CD20 treatment, Kupffer cells (KCs) mediate the abrupt arrest and subsequent engulfment of B cells circulating in the liver sinusoids. KCs were also effective in depleting malignant B cells in a model of spontaneous lymphoma. Our results identify Ab-dependent cellular phagocytosis by KCs as a primary mechanism of anti-CD20 therapy and provide an experimental framework for optimizing the efficacy of therapeutic Abs. PMID:24177426

  19. Single-wavelength two-photon excitation–stimulated emission depletion (SW2PE-STED) superresolution imaging

    PubMed Central

    Bianchini, Paolo; Harke, Benjamin; Galiani, Silvia; Vicidomini, Giuseppe; Diaspro, Alberto

    2012-01-01

    We developed a new class of two-photon excitation–stimulated emission depletion (2PE-STED) optical microscope. In this work, we show the opportunity to perform superresolved fluorescence imaging, exciting and stimulating the emission of a fluorophore by means of a single wavelength. We show that a widely used red-emitting fluorophore, ATTO647N, can be two-photon excited at a wavelength allowing both 2PE and STED using the very same laser source. This fact opens the possibility to perform 2PE microscopy at four to five times STED-improved resolution, while exploiting the intrinsic advantages of nonlinear excitation. PMID:22493221

  20. STED microscopy--super-resolution bio-imaging utilizing a stimulated emission depletion.

    PubMed

    Otomo, Kohei; Hibi, Terumasa; Kozawa, Yuichi; Nemoto, Tomomi

    2015-08-01

    One of the most popular super-resolution microscopies that breaks the diffraction barrier is stimulated emission depletion (STED) microscopy. As the optical set-up of STED microscopy is based on a laser scanning microscopy (LSM) system, it potentially has several merits of LSM like confocal or two-photon excitation LSM. In this article, we first describe the principles of STED microscopy and then describe the features of our newly developed two-photon excitation STED microscopy. On the basis of our recent results and those of other researchers, we conclude by discussing future research and new technologies in this field.

  1. Serotonin 2A Receptors, Citalopram and Tryptophan-Depletion: a Multimodal Imaging Study of their Interactions During Response Inhibition

    PubMed Central

    Macoveanu, Julian; Hornboll, Bettina; Elliott, Rebecca; Erritzoe, David; Paulson, Olaf B; Siebner, Hartwig; Knudsen, Gitte M; Rowe, James B

    2013-01-01

    Poor behavioral inhibition is a common feature of neurological and psychiatric disorders. Successful inhibition of a prepotent response in ‘NoGo' paradigms requires the integrity of both the inferior frontal gyrus (IFG) and the serotonergic system. We investigated individual differences in serotonergic regulation of response inhibition. In 24 healthy adults, we used 18F-altanserin positron emission tomography to assess cerebral 5-HT2A receptors, which have been related to impulsivity. We then investigated the impact of two acute manipulations of brain serotonin levels on behavioral and neural correlates of inhibition using intravenous citalopram and acute tryptophan depletion during functional magnetic resonance imaging. We adapted the NoGo paradigm to isolate effects on inhibition per se as opposed to other aspects of the NoGo paradigm. Successful NoGo inhibition was associated with greater activation of the right IFG compared to control trials with alternative responses, indicating that the IFG is activated with inhibition in NoGo trials rather than other aspects of invoked cognitive control. Activation of the left IFG during NoGo trials was greater with citalopram than acute tryptophan depletion. Moreover, with the NoGo-type of response inhibition, the right IFG displayed an interaction between the type of serotonergic challenge and neocortical 5-HT2A receptor binding. Specifically, acute tryptophan depletion (ATD) produced a relatively larger NoGo response in the right IFG in subjects with low 5-HT2A BPP but reduced the NoGo response in those with high 5-HT2A BPP. These links between serotonergic function and response inhibition in healthy subjects may help to interpret serotonergic abnormalities underlying impulsivity in neuropsychiatric disorders. PMID:23303045

  2. Back-illuminated, fully-depleted CCD image sensors for use in optical and near-IR astronomy

    NASA Astrophysics Data System (ADS)

    Groom, D. E.; Holland, S. E.; Levi, M. E.; Palaio, N. P.; Perlmutter, S.; Stover, R. J.; Wei, M.

    2000-03-01

    Charge-coupled devices (CCDs) of novel design have been fabricated at Lawrence Berkeley National Laboratory (LBNL), and the first large-format science-grade chips for astronomical imaging are now being characterized at Lick Observatory. They are made on 300-/μm thick n-type high-resistivity (~10000Ωcm) silicon wafers, using a technology developed at LBNL to fabricate low-leakage silicon microstrip detectors for high-energy physics. A bias voltage applied via a transparent contact on the back side fully depletes the substrate, making the entire volume photosensitive and ensuring that charge reaches the potential wells with minimal lateral diffusion. The development of a thin, transparent back-side contact compatible with fully depleted operation permits blue response comparable to that obtained with thinned CCDs. Since the entire region is active, high quantum efficiency is maintained to nearly λ=1000nm, above which the silicon band gap effectively truncates photoproduction. Early characterization results indicate a charge transfer efficiency />0.999995, readout noise 4 e's at /-132°C, full well capacity >300000e's, and quantum efficiency />85% at λ=900nm.

  3. The low-resolution imaging spectrograph red channel CCD upgrade: fully depleted, high-resistivity CCDs for Keck

    NASA Astrophysics Data System (ADS)

    Rockosi, C.; Stover, R.; Kibrick, R.; Lockwood, C.; Peck, M.; Cowley, D.; Bolte, M.; Adkins, S.; Alcott, B.; Allen, S. L.; Brown, B.; Cabak, G.; Deich, W.,; Hilyard, D.,; Kassis, M.,; Lanclos, K.,; Lewis, J.,; Pfister, T.,; Phillips, A.,; Robinson, L.,; Saylor, M.,; Thompson, M.,; Ward, J.,; Wei, M.,; Wright, C.,

    2010-07-01

    A mosaic of two 2k x 4k fully depleted, high resistivity CCD detectors was installed in the red channel of the Low Resolution Imaging Spectrograph for the Keck-I Telescope in June, 2009 replacing a monolithic Tektronix/SITe 2k x 2k CCD. These CCDs were fabricated at Lawrence Berkeley National Laboratory (LBNL) and packaged and characterized by UCO/Lick Observatory. Major goals of the detector upgrade were increased throughput and reduced interference fringing at wavelengths beyond 800 nm, as well as improvements in the maintainability and serviceability of the instrument. We report on the main features of the design, the results of optimizing detector performance during integration and testing, as well as the throughput, sensitivity and performance of the instrument as characterized during commissioning.

  4. Cathepsin Activity-Based Probes and Inhibitor for Preclinical Atherosclerosis Imaging and Macrophage Depletion

    PubMed Central

    Abd-Elrahman, Ihab; Kosuge, Hisanori; Wises Sadan, Tommy; Ben-Nun, Yael; Meir, Karen; Rubinstein, Chen; Bogyo, Matthew; McConnell, Michael V.

    2016-01-01

    Background and Purpose Cardiovascular disease is the leading cause of death worldwide, mainly due to an increasing prevalence of atherosclerosis characterized by inflammatory plaques. Plaques with high levels of macrophage infiltration are considered “vulnerable” while those that do not have significant inflammation are considered stable; cathepsin protease activity is highly elevated in macrophages of vulnerable plaques and contributes to plaque instability. Establishing novel tools for non-invasive molecular imaging of macrophages in plaques could aid in preclinical studies and evaluation of therapeutics. Furthermore, compounds that reduce the macrophage content within plaques should ultimately impact care for this disease. Methods We have applied quenched fluorescent cathepsin activity-based probes (ABPs) to a murine atherosclerosis model and evaluated their use for in vivo imaging using fluorescent molecular tomography (FMT), as well as ex vivo fluorescence imaging and fluorescent microscopy. Additionally, freshly dissected human carotid plaques were treated with our potent cathepsin inhibitor and macrophage apoptosis was evaluated by fluorescent microscopy. Results We demonstrate that our ABPs accurately detect murine atherosclerotic plaques non-invasively, identifying cathepsin activity within plaque macrophages. In addition, our cathepsin inhibitor selectively induced cell apoptosis of 55%±10% of the macrophage within excised human atherosclerotic plaques. Conclusions Cathepsin ABPs present a rapid diagnostic tool for macrophage detection in atherosclerotic plaque. Our inhibitor confirms cathepsin-targeting as a promising approach to treat atherosclerotic plaque inflammation. PMID:27532109

  5. Super-resolution stimulated emission depletion imaging of slit diaphragm proteins in optically cleared kidney tissue.

    PubMed

    Unnersjö-Jess, David; Scott, Lena; Blom, Hans; Brismar, Hjalmar

    2016-01-01

    The glomerular filtration barrier, consisting of podocyte foot processes with bridging slit diaphragm, glomerular basement membrane, and endothelium, is a key component for renal function. Previously, the subtlest elements of the filtration barrier have only been visualized using electron microscopy. However, electron microscopy is mostly restricted to ultrathin two-dimensional samples, and the possibility to simultaneously visualize multiple different proteins is limited. Therefore, we sought to implement a super-resolution immunofluorescence microscopy protocol for the study of the filtration barrier in the kidney. Recently, several optical clearing methods have been developed making it possible to image through large volumes of tissue and even whole organs using light microscopy. Here we found that hydrogel-based optical clearing is a beneficial tool to study intact renal tissue at the nanometer scale. When imaging samples using super-resolution STED microscopy, the staining quality was critical in order to assess correct nanoscale information. The signal-to-noise ratio and immunosignal homogeneity were both improved in optically cleared tissue. Thus, STED of slit diaphragms in fluorescently labeled, optically cleared, intact kidney samples is a new tool for studying the glomerular filtration barrier in health and disease.

  6. Analytical estimation of emission zone mean position and width in organic light-emitting diodes from emission pattern image-source interference fringes

    SciTech Connect

    Epstein, Ariel Tessler, Nir Einziger, Pinchas D.; Roberts, Matthew

    2014-06-14

    We present an analytical method for evaluating the first and second moments of the effective exciton spatial distribution in organic light-emitting diodes (OLED) from measured emission patterns. Specifically, the suggested algorithm estimates the emission zone mean position and width, respectively, from two distinct features of the pattern produced by interference between the emission sources and their images (induced by the reflective cathode): the angles in which interference extrema are observed, and the prominence of interference fringes. The relations between these parameters are derived rigorously for a general OLED structure, indicating that extrema angles are related to the mean position of the radiating excitons via Bragg's condition, and the spatial broadening is related to the attenuation of the image-source interference prominence due to an averaging effect. The method is applied successfully both on simulated emission patterns and on experimental data, exhibiting a very good agreement with the results obtained by numerical techniques. We investigate the method performance in detail, showing that it is capable of producing accurate estimations for a wide range of source-cathode separation distances, provided that the measured spectral interval is large enough; guidelines for achieving reliable evaluations are deduced from these results as well. As opposed to numerical fitting tools employed to perform similar tasks to date, our approximate method explicitly utilizes physical intuition and requires far less computational effort (no fitting is involved). Hence, applications that do not require highly resolved estimations, e.g., preliminary design and production-line verification, can benefit substantially from the analytical algorithm, when applicable. This introduces a novel set of efficient tools for OLED engineering, highly important in the view of the crucial role the exciton distribution plays in determining the device performance.

  7. Minimum joint space width (mJSW) of patellofemoral joint on standing "skyline" radiographs: test-retest reproducibility and comparison with quantitative magnetic resonance imaging (qMRI).

    PubMed

    Simoni, Paolo; Jamali, Sanaa; Albert, Adelin; Totterman, Saara; Schreyer, Edward; Tamez-Peña, Jose G; Zobel, Bruno Beomonte; Miezentseva, Victoria Alvarez; Gillet, Philippe

    2013-11-01

    To assess the intraobserver, interobserver, and test-retest reproducibility of minimum joint space width (mJSW) measurement of medial and lateral patellofemoral joints on standing "skyline" radiographs and to compare the mJSW of the patellofemoral joint to the mean cartilage thickness calculated by quantitative magnetic resonance imaging (qMRI). A couple of standing "skyline" radiographs of the patellofemoral joints and MRI of 55 knees of 28 volunteers (18 females, ten males, mean age, 48.5 ± 16.2 years) were obtained on the same day. The mJSW of the patellofemoral joint was manually measured and Kellgren and Lawrence grade (KLG) was independently assessed by two observers. The mJSW was compared to the mean cartilage thickness of patellofemoral joint calculated by qMRI. mJSW of the medial and lateral patellofemoral joint showed an excellent intraobserver agreement (interclass correlation (ICC) = 0.94 and 0.96), interobserver agreement (ICC = 0.90 and 0.95) and test-retest agreement (ICC = 0.92 and 0.96). The mJSW measured on radiographs was correlated to mean cartilage thickness calculated by qMRI (r = 0.71, p < 0.0001 for the medial PFJ and r = 0.81, p < 0.0001 for the lateral PFJ). However, there was a lack of concordance between radiographs and qMRI for extreme values of joint width and KLG. Radiographs yielded higher joint space measures than qMRI in knees with a normal joint space, while qMRI yielded higher joint space measures than radiographs in knees with joint space narrowing and higher KLG. Standing "skyline" radiographs are a reproducible tool for measuring the mJSW of the patellofemoral joint. The mJSW of the patellofemoral joint on radiographs are correlated with, but not concordant with, qMRI measurements.

  8. Tracking the stochastic fate of cells of the renin lineage after podocyte depletion using multicolor reporters and intravital imaging

    PubMed Central

    Eng, Diana G.; Rusiniak, Michael E.; Sequeira-Lopez, Maria Luisa S.; Gomez, R. Ariel; Pippin, Jeffrey W.; Gross, Kenneth W.; Peti-Peterdi, Janos; Shankland, Stuart J.

    2017-01-01

    Podocyte depletion plays a major role in focal segmental glomerular sclerosis (FSGS). Because cells of the renin lineage (CoRL) serve as adult podocyte and parietal epithelial cell (PEC) progenitor candidates, we generated Ren1cCre/R26R-ConfettiTG/WT and Ren1dCre/R26R-ConfettiTG/WT mice to determine CoRL clonality during podocyte replacement. Four CoRL reporters (GFP, YFP, RFP, CFP) were restricted to cells in the juxtaglomerular compartment (JGC) at baseline. Following abrupt podocyte depletion in experimental FSGS, all four CoRL reporters were detected in a subset of glomeruli at day 28, where they co-expressed de novo four podocyte proteins (podocin, nephrin, WT-1 and p57) and two glomerular parietal epithelial cell (PEC) proteins (claudin-1, PAX8). To monitor the precise migration of a subset of CoRL over a 2w period following podocyte depletion, intravital multiphoton microscopy was used. Our findings demonstrate direct visual support for the migration of single CoRL from the JGC to the parietal Bowman’s capsule, early proximal tubule, mesangium and glomerular tuft. In summary, these results suggest that following podocyte depletion, multi-clonal CoRL migrate to the glomerulus and replace podocyte and PECs in experimental FSGS. PMID:28329012

  9. Tracking the stochastic fate of cells of the renin lineage after podocyte depletion using multicolor reporters and intravital imaging.

    PubMed

    Kaverina, Natalya V; Kadoya, Hiroyuki; Eng, Diana G; Rusiniak, Michael E; Sequeira-Lopez, Maria Luisa S; Gomez, R Ariel; Pippin, Jeffrey W; Gross, Kenneth W; Peti-Peterdi, Janos; Shankland, Stuart J

    2017-01-01

    Podocyte depletion plays a major role in focal segmental glomerular sclerosis (FSGS). Because cells of the renin lineage (CoRL) serve as adult podocyte and parietal epithelial cell (PEC) progenitor candidates, we generated Ren1cCre/R26R-ConfettiTG/WT and Ren1dCre/R26R-ConfettiTG/WT mice to determine CoRL clonality during podocyte replacement. Four CoRL reporters (GFP, YFP, RFP, CFP) were restricted to cells in the juxtaglomerular compartment (JGC) at baseline. Following abrupt podocyte depletion in experimental FSGS, all four CoRL reporters were detected in a subset of glomeruli at day 28, where they co-expressed de novo four podocyte proteins (podocin, nephrin, WT-1 and p57) and two glomerular parietal epithelial cell (PEC) proteins (claudin-1, PAX8). To monitor the precise migration of a subset of CoRL over a 2w period following podocyte depletion, intravital multiphoton microscopy was used. Our findings demonstrate direct visual support for the migration of single CoRL from the JGC to the parietal Bowman's capsule, early proximal tubule, mesangium and glomerular tuft. In summary, these results suggest that following podocyte depletion, multi-clonal CoRL migrate to the glomerulus and replace podocyte and PECs in experimental FSGS.

  10. Understanding the impact of 5-HTTLPR, antidepressants, and acute tryptophan depletion on brain activation during facial emotion processing: A review of the imaging literature.

    PubMed

    Raab, Kyeon; Kirsch, Peter; Mier, Daniela

    2016-12-01

    Detecting and evaluating emotional information from facial expressions as a basis for behavioural adaption belong to the core social-cognitive abilities of mankind. Dysfunctions in emotional face processing are observed in several major psychiatric disorders like depression and schizophrenia. In search for psychiatric disease biomarkers using the imaging genetics approach, serotonergic gene polymorphisms have been associated with altered brain circuit activation during emotional face processing. Especially the 5-HTTLPR gene polymorphism has been extensively investigated in association with emotion regulation processes. In this article, imaging genetics literature on emotional face processing, reporting genetic effects of 5-HTTLPR in healthy volunteers is reviewed. Additionally, these results are regarded in relation to pharmacologic challenge (antidepressants, acute tryptophan depletion) imaging studies and discussed in light of recent neurobiological evidence with a focus on serotonin (5-HT1A, 5-HT2C, 5-HT2A) receptor findings. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Stimulated Emission Depletion Microscopy.

    PubMed

    Blom, Hans; Widengren, Jerker

    2017-06-14

    Despite its short history, diffraction-unlimited fluorescence microscopy techniques have already made a substantial imprint in the biological sciences. In this review, we describe how stimulated emission depletion (STED) imaging originally evolved, how it compares to other optical super-resolution imaging techniques, and what advantages it provides compared to previous golden-standards for biological microscopy, such as diffraction-limited optical microscopy and electron microscopy. We outline the prerequisites for successful STED imaging experiments, emphasizing the equally critical roles of instrumentation, sample preparation, and photophysics, and describe major evolving strategies for how to push the borders of STED imaging even further in life science. Finally, we provide examples of how STED nanoscopy can be applied, within three different fields with particular potential for STED imaging experiments: neuroscience, plasma membrane biophysics, and subcellular clinical diagnostics. In these areas, and in many more, STED imaging can be expected to play an increasingly important role in the future.

  12. Super-resolution imaging of ciliary microdomains in isolated olfactory sensory neurons using a custom two-color stimulated emission depletion microscope

    NASA Astrophysics Data System (ADS)

    Meyer, Stephanie A.; Ozbay, Baris N.; Potcoava, Mariana; Salcedo, Ernesto; Restrepo, Diego; Gibson, Emily A.

    2016-06-01

    We performed stimulated emission depletion (STED) imaging of isolated olfactory sensory neurons (OSNs) using a custom-built microscope. The STED microscope uses a single pulsed laser to excite two separate fluorophores, Atto 590 and Atto 647N. A gated timing circuit combined with temporal interleaving of the different color excitation/STED laser pulses filters the two channel detection and greatly minimizes crosstalk. We quantified the instrument resolution to be ˜81 and ˜44 nm, for the Atto 590 and Atto 647N channels. The spatial separation between the two channels was measured to be under 10 nm, well below the resolution limit. The custom-STED microscope is incorporated onto a commercial research microscope allowing brightfield, differential interference contrast, and epifluorescence imaging on the same field of view. We performed immunolabeling of OSNs in mice to image localization of ciliary membrane proteins involved in olfactory transduction. We imaged Ca2+-permeable cyclic nucleotide gated (CNG) channel (Atto 594) and adenylyl cyclase type III (ACIII) (Atto 647N) in distinct cilia. STED imaging resolved well-separated subdiffraction limited clusters for each protein. We quantified the size of each cluster to have a mean value of 88±48 nm and 124±43 nm, for CNG and ACIII, respectively. STED imaging showed separated clusters that were not resolvable in confocal images.

  13. Estrogen Depletion Results in Nanoscale Morphology Changes in Dermal Collagen

    PubMed Central

    Fang, Ming; Liroff, Kaitlin G.; Turner, A. Simon; Les, Clifford M.; Orr, Bradford G.; Holl, Mark M. Banaszak

    2012-01-01

    Tissue cryo-sectioning combined with Atomic Force Microscopy (AFM) imaging reveals that the nanoscale morphology of dermis collagen fibrils, quantified using the metric of D-periodic spacing, changes under the condition of estrogen depletion. Specifically, a new subpopulation of fibrils with D-spacings in the region between 56 and 59 nm is present two years following ovariectomy in ovine dermal samples. In addition, the overall width of the distribution, both values above and below the mean, has increased. The change in width due to an increase in lower values of D-spacings was previously reported for ovine bone; however, this report demonstrates that the effect is also present in non-mineralized collagen fibrils. A non-parametric Kolmogrov-Smirnov test of the cumulative density function indicates a statistical difference in the sham and OVX D-spacing distributions (p < 0.01). PMID:22437310

  14. Diatomic predissociation line widths

    NASA Technical Reports Server (NTRS)

    Child, M. S.

    1973-01-01

    Predissociation by rotation and curve crossing in diatomic molecules is discussed. The pattern of predissociation line widths is seen as providing a highly sensitive yardstick for the determination of unknown potential curves. In addition, the computation of such a pattern for given potential curves is considered a matter of routine, unless the predissociation happens to occur from an adiabatic potential curve. Analytic formulas are used to provide physical insight into the details of the predissociation pattern, to the extent that a direct inversion procedure is developed for determination of the repulsive potential curves for Type 1 predissociations.

  15. Imaging Lung Clearance of Radiolabeled Tumor Cells to Study Mice with Normal, Activated or Depleted Natural Killer (NK) Cells

    NASA Astrophysics Data System (ADS)

    Kulkarni, P. V.; Bennett, M.; Constantinescu, A.; Arora, V.; Viguet, M.; Antich, P.; Parkey, R. W.; Mathews, D.; Mason, R. P.; Oz, O. K.

    2003-08-01

    Lung clearance of 51CR and 125I iododeoxyuridine (IUDR) labeled cancer cells assess NK cell activity. It is desirable to develop noninvasive imaging technique to assess NK activity in mice. We labeled target YAC-1 tumor cells with 125I, 111In, 99mTc, or 67Ga and injected I.V. into three groups of BALB/c mice. Animals were treated with medium (group I), 300mg/kg cyclophosmamide (CY) to kill NK cell (group II), or anti-LY49C/1) (ab')2 mAb to augment NK function (group III). Lungs were removed 15 min or 2 h later for tissue counting. Control and treated mice were imaged every 5 min with a scintillating camera for 1 h after 15 min of infusion of the 111In labeled cells. Lung clearance increased after 15 min (lodging: 60-80%) and (2 h retention: 3-7%). Similar results were obtained with all the isotopes studied. Images distinguished the control and treated mice for lung activity. Cells labeled with 111In, 99mTc or 67Ga are cleared similar to those labeled with 51Cr or 125I. NK cell destruction of tumor cells may be assessed by noninvasive imaging method either by SPECT (99mTc, 111In, 67Ga) or by PET (68Ga).

  16. Imaging Lung Clearance of Radiolabeled Tumor Cells to Study Mice with Normal, Activated or Depleted Natural Killer (NK) Cells

    SciTech Connect

    Kulkarni, P.V.; Bennett, M.; Constantinescu, A.; Arora, V.; Viguet, M.; Antich, P.; Parkey, R.W.; Mathews, D.; Mason, R.P.; Oz, O.K.

    2003-08-26

    Lung clearance of 51CR and 125I iododeoxyuridine (IUDR) labeled cancer cells assess NK cell activity. It is desirable to develop noninvasive imaging technique to assess NK activity in mice. We labeled target YAC-1 tumor cells with 125I, 111In, 99mTc, or 67Ga and injected I.V. into three groups of BALB/c mice. Animals were treated with medium (group I), 300mg/kg cyclophosmamide (CY) to kill NK cell (group II), or anti-LY49C/1) (ab')2 mAb to augment NK function (group III). Lungs were removed 15 min or 2 h later for tissue counting. Control and treated mice were imaged every 5 min with a scintillating camera for 1 h after 15 min of infusion of the 111In labeled cells. Lung clearance increased after 15 min (lodging: 60-80%) and (2 h retention: 3-7%). Similar results were obtained with all the isotopes studied. Images distinguished the control and treated mice for lung activity. Cells labeled with 111In, 99mTc or 67Ga are cleared similar to those labeled with 51Cr or 125I. NK cell destruction of tumor cells may be assessed by noninvasive imaging method either by SPECT (99mTc, 111In, 67Ga) or by PET (68Ga)

  17. Development for Germanium Blocked Impurity Band Far-Infrared Image Sensors with Fully-Depleted Silicon-On-Insulator CMOS Readout Integrated Circuit

    NASA Astrophysics Data System (ADS)

    Wada, T.; Arai, Y.; Baba, S.; Hanaoka, M.; Hattori, Y.; Ikeda, H.; Kaneda, H.; Kochi, C.; Miyachi, A.; Nagase, K.; Nakaya, H.; Ohno, M.; Oyabu, S.; Suzuki, T.; Ukai, S.; Watanabe, K.; Yamamoto, K.

    2016-07-01

    We are developing far-infrared (FIR) imaging sensors for low-background and high-sensitivity applications such as infrared astronomy. Previous FIR monolithic imaging sensors, such as an extrinsic germanium photo-conductor (Ge PC) with a PMOS readout integrated circuit (ROIC) hybridized by indium pixel-to-pixel interconnection, had three difficulties: (1) short cut-off wavelength (120 \\upmu m), (2) large power consumption (10 \\upmu W/pixel), and (3) large mismatch in thermal expansion between the Ge PC and the Si ROIC. In order to overcome these difficulties, we developed (1) a blocked impurity band detector fabricated by a surface- activated bond technology, whose cut-off wavelength is longer than 160 \\upmu m, (2) a fully-depleted silicon-on-insulator CMOS ROIC which works below 4 K with 1 \\upmu W/pixel operating power, and (3) a new concept, Si-supported Ge detector, which shows tolerance to thermal cycling down to 3 K. With these new techniques, we are now developing a 32 × 32 FIR imaging sensor.

  18. The severity of anaemia depletes cerebrovascular dilatory reserve in children with sickle cell disease: a quantitative magnetic resonance imaging study.

    PubMed

    Kosinski, Przemyslaw D; Croal, Paula L; Leung, Jackie; Williams, Suzan; Odame, Isaac; Hare, Gregory M T; Shroff, Manohar; Kassner, Andrea

    2017-01-01

    Overt ischaemic stroke is one of the most devastating complications in children with sickle cell disease (SCD). The compensatory response to anaemia in SCD includes an increase in cerebral blood flow (CBF) by accessing cerebrovascular dilatory reserve. Exhaustion of dilatory reserve secondary to anaemic stress may lead to cerebral ischaemia. The purpose of this study was to investigate CBF and cerebrovascular reactivity (CVR) using magnetic resonance imaging (MRI) in children with SCD and to correlate these with haematological markers of anaemia. Baseline CBF was measured using arterial spin labelling. Blood-oxygen level-dependent MRI in response to a CO2 stimulus was used to acquire CVR. In total, 28 children with SCD (23 not on any disease-modifying treatment, 5 on chronic transfusion) and 22 healthy controls were imaged using MRI. Transfusion patients were imaged at two time points to assess the effect of changes in haematocrit after a transfusion cycle. In children with SCD, CBF was significantly elevated compared to healthy controls, while CVR was significantly reduced. Both measures were significantly correlated with haematocrit. For transfusion patients, CBF decreased and CVR increased following a transfusion cycle. Lastly, a significant correlation was observed between CBF and CVR in both children with SCD and healthy controls. © 2016 John Wiley & Sons Ltd.

  19. Width of nonlinear resonance

    SciTech Connect

    Ohnuma, S.

    1984-03-01

    Two approximations are made, one essential and the other not so essential but convenient to keep the analytical treatment manageable: (1) Only one nonlinear resonance is considered at a time so that the treatment is best suited when the tune is close to one resonance only. To improve this approximation, one must go to the next order which involves a canonical transformation of dynamical variables. Analytical treatment of more than one resonance is not possible for general cases. (2) In the formalism using the action-angle variables, the Hamiltonian can have terms which are independent of the angle variables. These terms are called phase-independent terms or shear terms. The tune is then a function of the oscillation amplitudes. In the lowest-order treatment, the (4N)-pole components but not the (4N + 2)-pole components contribute to this dependence. In deriving the resonance width analytically, one ignores these terms in the Hamiltonian for the sake of simplicity. If these are retained, one needs at least three extra parameters and the analytical treatment becomes rather unwieldy.

  20. The Width of a Proof

    ERIC Educational Resources Information Center

    Hanna, Gila

    2014-01-01

    This paper's aim is to discuss the concept of width of a proof put forward by Timothy Gowers. It explains what this concept means and attempts to show how it relates to other concepts discussed in the existing literature on proof and proving. It also explores how the concept of width of a proof might be used productively in the mathematics…

  1. Phase width reduction project summary

    SciTech Connect

    Clark, D.J.; Xie, Z.Q.; McMahan, M. A.

    1999-11-01

    The purpose of the phase width reduction project, 1993--96, was to reduce the phase width of the 88-Inch Cyclotron beam on target from 5--10 ns to 1--2 ns for certain experiments, such as Gammasphere, which use time-of-flight identification. Since reducing the phase width also reduces beam intensity, tuning should be done to also optimize the transmission. The Multi-turn Collimator slits in the cyclotron center region were used to collimate the early turns radially, thus reducing the phase width from about 5 ns to 1--2 ns FWHM for a Gammasphere beam. The effect of the slits on phase width was verified with a Fast Faraday Cup and with particle and gamma-ray detectors in the external beamline.

  2. Fully depleted back illuminated CCD

    DOEpatents

    Holland, Stephen Edward

    2001-01-01

    A backside illuminated charge coupled device (CCD) is formed of a relatively thick high resistivity photon sensitive silicon substrate, with frontside electronic circuitry, and an optically transparent backside ohmic contact for applying a backside voltage which is at least sufficient to substantially fully deplete the substrate. A greater bias voltage which overdepletes the substrate may also be applied. One way of applying the bias voltage to the substrate is by physically connecting the voltage source to the ohmic contact. An alternate way of applying the bias voltage to the substrate is to physically connect the voltage source to the frontside of the substrate, at a point outside the depletion region. Thus both frontside and backside contacts can be used for backside biasing to fully deplete the substrate. Also, high resistivity gaps around the CCD channels and electrically floating channel stop regions can be provided in the CCD array around the CCD channels. The CCD array forms an imaging sensor useful in astronomy.

  3. Water Depletion Threatens Agriculture

    NASA Astrophysics Data System (ADS)

    Brauman, K. A.; Richter, B. D.; Postel, S.; Floerke, M.; Malsy, M.

    2014-12-01

    Irrigated agriculture is the human activity that has by far the largest impact on water, constituting 85% of global water consumption and 67% of global water withdrawals. Much of this water use occurs in places where water depletion, the ratio of water consumption to water availability, exceeds 75% for at least one month of the year. Although only 17% of global watershed area experiences depletion at this level or more, nearly 30% of total cropland and 60% of irrigated cropland are found in these depleted watersheds. Staple crops are particularly at risk, with 75% of global irrigated wheat production and 65% of irrigated maize production found in watersheds that are at least seasonally depleted. Of importance to textile production, 75% of cotton production occurs in the same watersheds. For crop production in depleted watersheds, we find that one half to two-thirds of production occurs in watersheds that have not just seasonal but annual water shortages, suggesting that re-distributing water supply over the course of the year cannot be an effective solution to shortage. We explore the degree to which irrigated production in depleted watersheds reflects limitations in supply, a byproduct of the need for irrigation in perennially or seasonally dry landscapes, and identify heavy irrigation consumption that leads to watershed depletion in more humid climates. For watersheds that are not depleted, we evaluate the potential impact of an increase in irrigated production. Finally, we evaluate the benefits of irrigated agriculture in depleted and non-depleted watersheds, quantifying the fraction of irrigated production going to food production, animal feed, and biofuels.

  4. Masses, widths, and leptonic widths of the higher upsilon resonances

    NASA Astrophysics Data System (ADS)

    Lovelock, D. M.; Horstkotte, J. E.; Klopfenstein, C.; Lee-Franzini, J.; Romero, L.; Schamberger, R. D.; Youssef, S.; Franzini, P.; Son, D.; Tuts, P. M.; Zhao, T.; Herb, S.; Dietl, H.; Eigen, G.; Fonseca, V.; Lorenz, E.; Mageras, G.; Han, K.; Imlay, R.; Metcalf, W.; Sreedhar, V.

    1985-02-01

    The masses, total widths, and leptonic widths of three triplet s-wave bb¯ states Υ(4S), Υ(5S), and Υ(6S) are determined from measurements of the e+e- annihilation cross section into hadrons for 10.55

  5. Relation between index finger width and hand width anthropometric measures.

    PubMed

    Komandur, Sashidharan; Johnson, Peter W; Storch, Richard L; Yost, Michael G

    2009-01-01

    Measures of hand and finger anthropometry are very important for designing many hand held devices as well as understanding anthropometric effects on the operation of such devices. Many historical datasets have measured and recorded gross hand dimensions but do not often record the finer dimensions of the hand such as finger anthropometry. Knowing the size and mass of fingers across genders can be critical to the design and operation of hand held devices. In this paper we compare two empirical linear models that predicts index finger width at the proximal interphalangeal (PIP) joint (a finger anthropometric measure) based on hand-width (hand anthropometric measure). This will be especially useful for deriving population measures of finger anthropometry from large historical data sets where only gross hand dimensions are available.

  6. Line Width Recovery after Vectorization of Engineering Drawings

    NASA Astrophysics Data System (ADS)

    Gramblička, Matúš; Vaský, Jozef

    2016-12-01

    Vectorization is the conversion process of a raster image representation into a vector representation. The contemporary commercial vectorization software applications do not provide sufficiently high quality outputs for such images as do mechanical engineering drawings. Line width preservation is one of the problems. There are applications which need to know the line width after vectorization because this line attribute carries the important semantic information for the next 3D model generation. This article describes the algorithm that is able to recover line width of individual lines in the vectorized engineering drawings. Two approaches are proposed, one examines the line width at three points, whereas the second uses a variable number of points depending on the line length. The algorithm is tested on real mechanical engineering drawings.

  7. Halo Star Lithium Depletion

    SciTech Connect

    Pinsonneault, M. H.; Walker, T. P.; Steigman, G.; Narayanan, Vijay K.

    1999-12-10

    The depletion of lithium during the pre-main-sequence and main-sequence phases of stellar evolution plays a crucial role in the comparison of the predictions of big bang nucleosynthesis with the abundances observed in halo stars. Previous work has indicated a wide range of possible depletion factors, ranging from minimal in standard (nonrotating) stellar models to as much as an order of magnitude in models that include rotational mixing. Recent progress in the study of the angular momentum evolution of low-mass stars permits the construction of theoretical models capable of reproducing the angular momentum evolution of low-mass open cluster stars. The distribution of initial angular momenta can be inferred from stellar rotation data in young open clusters. In this paper we report on the application of these models to the study of lithium depletion in main-sequence halo stars. A range of initial angular momenta produces a range of lithium depletion factors on the main sequence. Using the distribution of initial conditions inferred from young open clusters leads to a well-defined halo lithium plateau with modest scatter and a small population of outliers. The mass-dependent angular momentum loss law inferred from open cluster studies produces a nearly flat plateau, unlike previous models that exhibited a downward curvature for hotter temperatures in the 7Li-Teff plane. The overall depletion factor for the plateau stars is sensitive primarily to the solar initial angular momentum used in the calibration for the mixing diffusion coefficients. Uncertainties remain in the treatment of the internal angular momentum transport in the models, and the potential impact of these uncertainties on our results is discussed. The 6Li/7Li depletion ratio is also examined. We find that the dispersion in the plateau and the 6Li/7Li depletion ratio scale with the absolute 7Li depletion in the plateau, and we use observational data to set bounds on the 7Li depletion in main-sequence halo

  8. Live-cell imaging reveals sequential oligomerization and local plasma membrane targeting of stromal interaction molecule 1 after Ca2+ store depletion

    PubMed Central

    Liou, Jen; Fivaz, Marc; Inoue, Takanari; Meyer, Tobias

    2007-01-01

    Stromal interaction molecule 1 (STIM1) has recently been identified by our group and others as an endoplasmic reticulum (ER) Ca2+ sensor that responds to ER Ca2+ store depletion and activates Ca2+ channels in the plasma membrane (PM). The molecular mechanism by which STIM1 transduces signals from the ER lumen to the PM is not yet understood. Here we developed a live-cell FRET approach and show that STIM1 forms oligomers within 5 s after Ca2+ store depletion. These oligomers rapidly dissociated when ER Ca2+ stores were refilled. We further show that STIM1 formed oligomers before its translocation within the ER network to ER–PM junctions. A mutant STIM1 lacking the C-terminal polybasic PM-targeting motif oligomerized after Ca2+ store depletion but failed to form puncta at ER–PM junctions. Using fluorescence recovery after photobleaching measurements to monitor STIM1 mobility, we show that STIM1 oligomers translocate on average only 2 μm to reach ER–PM junctions, arguing that STIM1 ER-to-PM signaling is a local process that is suitable for generating cytosolic Ca2+ gradients. Together, our live-cell measurements dissect the STIM1 ER-to-PM signaling relay into four sequential steps: (i) dissociation of Ca2+, (ii) rapid oligomerization, (iii) spatially restricted translocation to nearby ER–PM junctions, and (iv) activation of PM Ca2+ channels. PMID:17517596

  9. Depleted Uranium: Technical Brief

    EPA Pesticide Factsheets

    This technical brief provides accepted data and references to additional sources for radiological and chemical characteristics, health risks and references for both the monitoring and measurement, and applicable treatment techniques for depleted uranium.

  10. Battery depletion monitor

    SciTech Connect

    Lee, Y.S.

    1982-01-26

    A cmos inverter is used to compare pacemaker battery voltage to a referenced voltage. When the reference voltage exceeds the measured battery voltage, the inverter changes state to indicate battery depletion.

  11. Addressing Ozone Layer Depletion

    EPA Pesticide Factsheets

    Access information on EPA's efforts to address ozone layer depletion through regulations, collaborations with stakeholders, international treaties, partnerships with the private sector, and enforcement actions under Title VI of the Clean Air Act.

  12. Testing fully depleted CCD

    NASA Astrophysics Data System (ADS)

    Casas, Ricard; Cardiel-Sas, Laia; Castander, Francisco J.; Jiménez, Jorge; de Vicente, Juan

    2014-08-01

    The focal plane of the PAU camera is composed of eighteen 2K x 4K CCDs. These devices, plus four spares, were provided by the Japanese company Hamamatsu Photonics K.K. with type no. S10892-04(X). These detectors are 200 μm thick fully depleted and back illuminated with an n-type silicon base. They have been built with a specific coating to be sensitive in the range from 300 to 1,100 nm. Their square pixel size is 15 μm. The read-out system consists of a Monsoon controller (NOAO) and the panVIEW software package. The deafualt CCD read-out speed is 133 kpixel/s. This is the value used in the calibration process. Before installing these devices in the camera focal plane, they were characterized using the facilities of the ICE (CSIC- IEEC) and IFAE in the UAB Campus in Bellaterra (Barcelona, Catalonia, Spain). The basic tests performed for all CCDs were to obtain the photon transfer curve (PTC), the charge transfer efficiency (CTE) using X-rays and the EPER method, linearity, read-out noise, dark current, persistence, cosmetics and quantum efficiency. The X-rays images were also used for the analysis of the charge diffusion for different substrate voltages (VSUB). Regarding the cosmetics, and in addition to white and dark pixels, some patterns were also found. The first one, which appears in all devices, is the presence of half circles in the external edges. The origin of this pattern can be related to the assembly process. A second one appears in the dark images, and shows bright arcs connecting corners along the vertical axis of the CCD. This feature appears in all CCDs exactly in the same position so our guess is that the pattern is due to electrical fields. Finally, and just in two devices, there is a spot with wavelength dependence whose origin could be the result of a defectous coating process.

  13. Auto-aligning stimulated emission depletion microscope using adaptive optics.

    PubMed

    Gould, Travis J; Kromann, Emil B; Burke, Daniel; Booth, Martin J; Bewersdorf, Joerg

    2013-06-01

    Stimulated emission depletion (STED) microscopy provides diffraction-unlimited resolution in fluorescence microscopy. Imaging at the nanoscale, however, requires precise alignment of the depletion and excitation laser foci of the STED microscope. We demonstrate here that adaptive optics can be implemented to automatically align STED and confocal images with a precision of 4.3 ± 2.3 nm.

  14. Accurate vessel width measurement from fundus photographs: a new concept.

    PubMed Central

    Rassam, S M; Patel, V; Brinchmann-Hansen, O; Engvold, O; Kohner, E M

    1994-01-01

    Accurate determination of retinal vessel width measurement is important in the study of the haemodynamic changes that accompany various physiological and pathological states. Currently the width at the half height of the transmittance and densitometry profiles are used as a measure of retinal vessel width. A consistent phenomenon of two 'kick points' on the slopes of the transmittance and densitometry profiles near the base, has been observed. In this study, mathematical models have been formulated to describe the characteristic curves of the transmittance and the densitometry profiles. They demonstrate the kick points being coincident with the edges of the blood column. The horizontal distance across the kick points would therefore indicate the actual blood column width. To evaluate this hypothesis, blood was infused through two lengths of plastic tubing of known diameters, and photographed. In comparison with the known diameters, the half height underestimated the blood column width by 7.33% and 6.46%, while the kick point method slightly overestimated it by 1.40% and 0.34%. These techniques were applied to monochromatic fundus photographs. In comparison with the kick point method, the half height underestimated the blood column width in veins by 16.67% and in arteries by 15.86%. The characteristics of the kick points and their practicality have been discussed. The kick point method may provide the most accurate measurement of vessel width possible from these profiles. Images PMID:8110693

  15. Automated width measurements of Martian dust devil tracks

    NASA Astrophysics Data System (ADS)

    Statella, Thiago; Pina, Pedro; da Silva, Erivaldo Antônio

    2016-03-01

    Studying dust devils is important to better understand Mars climate and resurfacing phenomena. This paper presents an automated approach to calculate the width of tracks in orbital images. The method is based on Mathematical Morphology and was applied to a set of 200 HiRISE and MOC images of five Mars quadrangles, which were Aeolis, Argyre, Noachis, Hellas and Eridania. Information obtained by our method was compared with results of manual analysis performed by other authors. In addition, we show that track widths do not follow a normal distribution.

  16. Variation in the Width of Transition Region Network Boundaries

    NASA Astrophysics Data System (ADS)

    Raju, K. P.

    2016-12-01

    The transition region network seen in solar extreme ultraviolet (EUV) lines is the extension of the chromospheric network. The network appears as an irregular web-like pattern over the solar surface outside active regions. The average width of transition region network boundaries is obtained from the two-dimensional autocorrelation function of SOlar and Heliospheric Observatory (SOHO)/ Coronal Diagnostic Spectrometer (CDS) synoptic images of the Sun in two emission lines, He i 586 Å and O v 630 Å during 1996 - 2012. The width of the network boundaries is found to be roughly correlated with the solar cycle variation with a lag of about ten months. A comparison of the widths in the two emission lines shows that they are larger for the He i line. The SOHO/CDS data also show large asymmetry in boundary widths in the horizontal (x) and vertical (y) image directions, which is shown to be caused by image distortions that are due to instrumental effects. Since the network boundary widths are related to the magnetic flux concentration along the boundaries, the results are expected to have implications on the flux transport on the solar surface, solar cycle, and the mass and energy budget of network loops and jets.

  17. Cholesterol depletion induces autophagy

    SciTech Connect

    Cheng, Jinglei; Ohsaki, Yuki; Tauchi-Sato, Kumi; Fujita, Akikazu; Fujimoto, Toyoshi . E-mail: tfujimot@med.nagoya-u.ac.jp

    2006-12-08

    Autophagy is a mechanism to digest cells' own components, and its importance in many physiological and pathological processes is being recognized. But the molecular mechanism that regulates autophagy is not understood in detail. In the present study, we found that cholesterol depletion induces macroautophagy. The cellular cholesterol in human fibroblasts was depleted either acutely using 5 mM methyl-{beta}-cyclodextrin or 10-20 {mu}g/ml nystatin for 1 h, or metabolically by 20 {mu}M mevastatin and 200 {mu}M mevalonolactone along with 10% lipoprotein-deficient serum for 2-3 days. By any of these protocols, marked increase of LC3-II was detected by immunoblotting and by immunofluorescence microscopy, and the increase was more extensive than that caused by amino acid starvation, i.e., incubation in Hanks' solution for several hours. The induction of autophagic vacuoles by cholesterol depletion was also observed in other cell types, and the LC3-positive membranes were often seen as long tubules, >50 {mu}m in length. The increase of LC3-II by methyl-{beta}-cyclodextrin was suppressed by phosphatidylinositol 3-kinase inhibitors and was accompanied by dephosphorylation of mammalian target of rapamycin. By electron microscopy, autophagic vacuoles induced by cholesterol depletion were indistinguishable from those seen after amino acid starvation. These results demonstrate that a decrease in cholesterol activates autophagy by a phosphatidylinositol 3-kinase-dependent mechanism.

  18. 7 CFR 29.1085 - Width.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... Width, as an element of quality, does not apply to tobacco in strip form. (See Elements of Quality Chart... Heavy Fleshy Medium Thin Oil Lean Oily Rich Color intensity Pale Weak Moderate Strong Deep. Width... quality...

  19. 7 CFR 29.1085 - Width.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... Width, as an element of quality, does not apply to tobacco in strip form. (See Elements of Quality Chart... Heavy Fleshy Medium Thin Oil Lean Oily Rich Color intensity Pale Weak Moderate Strong Deep. Width... quality...

  20. Computerized analysis of retinal vessel width and tortuosity in premature infants.

    PubMed

    Wilson, Clare M; Cocker, Kenneth D; Moseley, Merrick J; Paterson, Carl; Clay, Simon T; Schulenburg, William E; Mills, Monte D; Ells, Anna L; Parker, Kim H; Quinn, Graham E; Fielder, Alistair R; Ng, Jeffrey

    2008-08-01

    To determine, with novel software, the feasibility of measuring the tortuosity and width of retinal veins and arteries from digital retinal images of infants at risk of retinopathy of prematurity (ROP). The Computer-Aided Image Analysis of the Retina (CAIAR) program was developed to enable semiautomatic detection of retinal vasculature and measurement of vessel tortuosity and width from digital images. CAIAR was tested for accuracy and reproducibility of tortuosity and width measurements by using computer-generated vessel-like lines of known frequency, amplitude, and width. CAIAR was then tested by using clinical digital retinal images for correlation of vessel tortuosity and width readings compared with expert ophthalmologist grading. When applied to 16 computer-generated sinusoidal vessels, the tortuosity measured by CAIAR correlated very well with the known values. Width measures also increased as expected. When the CAIAR readings were compared with five expert ophthalmologists' grading of 75 vessels on 10 retinal images, moderate correlation was found in 10 of the 14 tortuosity output calculations (Spearman rho = 0.618-0.673). Width was less well correlated (rho = 0.415). The measures of tortuosity and width in CAIAR were validated using sequential model vessel analysis. On comparison of CAIAR output with assessments made by expert ophthalmologists, CAIAR correlates moderately with tortuosity grades, but less well with width grades. CAIAR offers the opportunity to develop an automated image analysis system for detecting the vascular changes at the posterior pole, which are becoming increasingly important in diagnosing treatable ROP.

  1. 14 CFR 121.115 - Route width.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Route width. (a) Routes and route segments over Federal airways, foreign airways, or advisory routes have a width equal to the designated width of those airways or advisory routes. Whenever the... clearance. (2) Minimum en route altitudes. (3) Ground and airborne navigation aids. (4) Air traffic density...

  2. 14 CFR 121.115 - Route width.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Route width. (a) Routes and route segments over Federal airways, foreign airways, or advisory routes have a width equal to the designated width of those airways or advisory routes. Whenever the... clearance. (2) Minimum en route altitudes. (3) Ground and airborne navigation aids. (4) Air traffic density...

  3. 14 CFR 121.115 - Route width.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Route width. (a) Routes and route segments over Federal airways, foreign airways, or advisory routes have a width equal to the designated width of those airways or advisory routes. Whenever the... clearance. (2) Minimum en route altitudes. (3) Ground and airborne navigation aids. (4) Air traffic density...

  4. 14 CFR 121.115 - Route width.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Route width. (a) Routes and route segments over Federal airways, foreign airways, or advisory routes have a width equal to the designated width of those airways or advisory routes. Whenever the... clearance. (2) Minimum en route altitudes. (3) Ground and airborne navigation aids. (4) Air traffic density...

  5. 14 CFR 121.115 - Route width.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Route width. (a) Routes and route segments over Federal airways, foreign airways, or advisory routes have a width equal to the designated width of those airways or advisory routes. Whenever the... clearance. (2) Minimum en route altitudes. (3) Ground and airborne navigation aids. (4) Air traffic density...

  6. 23 CFR 658.15 - Width.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS TRUCK SIZE AND WEIGHT, ROUTE DESIGNATIONS-LENGTH, WIDTH AND WEIGHT LIMITATIONS § 658.15 Width. (a) No State shall impose a width limitation of more or less than 102 inches, or its approximate metric equivalent, 2.6 meters (102.36 inches) on...

  7. A closer look at the `characteristic' width of molecular cloud filaments

    NASA Astrophysics Data System (ADS)

    Panopoulou, G. V.; Psaradaki, I.; Skalidis, R.; Tassis, K.; Andrews, J. J.

    2017-04-01

    Filaments in Herschel molecular cloud images are found to exhibit a 'characteristic width'. This finding is in tension with spatial power spectra of the data, which show no indication of this characteristic scale. We demonstrate that this discrepancy is a result of the methodology adopted for measuring filament widths. First, we perform the previously used analysis technique on artificial scale-free data, and obtain a peaked width distribution of filament-like structures. Next, we repeat the analysis on three Herschel maps and reproduce the narrow distribution of widths found in previous studies - when considering the average width of each filament. However, the distribution of widths measured at all points along a filament spine is broader than the distribution of mean filament widths, indicating that the narrow spread (interpreted as a 'characteristic' width) results from averaging. Furthermore, the width is found to vary significantly from one end of a filament to the other. Therefore, the previously identified peak at 0.1 pc cannot be understood as representing the typical width of filaments. We find an alternative explanation by modelling the observed width distribution as a truncated power-law distribution, sampled with uncertainties. The position of the peak is connected to the lower truncation scale and is likely set by the choice of parameters used in measuring filament widths. We conclude that a 'characteristic' width of filaments is not supported by the available data.

  8. Difference of CBD width on US vs. ERCP.

    PubMed

    Brook, Olga R; Suissa, Alain; Khamaysi, Iyad; Koren, Dorit; Gaitini, Diana

    2007-01-01

    To investigate the relationship between US and ERCP in the measurement of common bile duct (CBD) width after application of Compound and Harmonic imaging on ultrasound. We prospectively evaluated the CBD width as measured on endoscopic retrograde cholangiopancreatography (ERCP) and ultrasonography (US), applying Compound and Harmonic US techniques, on 100 patients. Furthermore, we retrospectively re-examined US and ERCP images of 48 patients who underwent ERCP and US during the same hospitalization period. The average difference in measurements by US compared to ERCP was 2.3 mm (P < 0.01) in the retrospective and 1.9 mm in the prospective study (P < 0.001). The average difference in measurements between US and ERCP in post-cholecystectomy patients was 4.0 mm in the retrospective study (10 patients), and 3.8 in the prospective study (25 patients). The difference between the measurements on both examinations decreased with increasing CBD width. There was a good correlation between ERCP and US measurements of CBD width (r = 0.73 for all patients and r = 0.88 for patients with intact gallbladder, P < 0.001). There is a gap between measurement of CBD width on US and ERCP of about 2 mm. The application of Compound and Harmonic techniques in the prospective study probably enabled a more accurate sonographic measurement.

  9. Quantifying River Widths of North America from Satellite Imagery

    NASA Astrophysics Data System (ADS)

    Allen, G. H.; Pavelsky, T.; Miller, Z.

    2013-12-01

    River width is a fundamental predictor variable in many hydrologic, geomorphic, and biogeochemical models, yet current large-scale models rely on theoretical hydraulic geometry relationships that do not fully capture natural variability in river form. Here we present the first high-resolution dataset of long-term mean width of North American rivers wider than 30 m. The dataset contains 7.93 million georeferenced width measurements derived from Landsat TM and ETM+ imagery that were acquired when rivers were most likely to be at mean discharge. We built the dataset by developing an automated procedure that selects and downloads raw imagery, creates cloud-free normalized difference water index images, histogram balances and mosaics them together, and produces a water mask using a dynamic water-land threshold technique. We then visually inspected and corrected the mask for errors and used RivWidth software to calculate river width at each river centerline pixel. We validated our dataset using >1000 United States Geological Survey and Water Survey of Canada in situ gauge station measurements. Error analysis shows a robust relationship between the remotely sensed widths and in situ gauge measurements with an r 2 = 0.86 (Spearman's = 0.81) and a mean absolute error of 27.5 m. We find that North American river widths lie on logarithmic frequency curve with some notable exceptions at widths <100 m. This dataset can be used to improve our understanding of the water, carbon, and nitrogen cycles, as well as large-scale landscape evolution models. Our results also allow for the characterization of the extent of rivers likely to be observable by the planned Surface Water and Ocean Topography (SWOT) satellite mission.

  10. Energy-discrimination X-ray computed tomography system utilizing a silicon-PIN detector and its application to 2.0-keV-width K-edge imaging

    NASA Astrophysics Data System (ADS)

    Hagiwara, Osahiko; Watanabe, Manabu; Sato, Eiichi; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Nagao, Jiro; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

    2011-05-01

    Demonstration of narrow-energy-width computed tomography (CT) was carried out by means of energy-discrimination. An X-ray CT system is of a first-generation type and consists of an X-ray generator, a turntable, a translation stage, a two-stage controller, a silicon-PIN detector system with amplifiers, a multi-channel analyzer (MCA), a counter card (CC), and a personal computer (PC). CT is accomplished by repeating the translation and the rotation of an object, and projection curves of the object are obtained by the translation of the moving object. Both photon-energy level and energy width are determined by the MCA, and the pulses of the discriminated event signal from the MCA are counted by CC in conjunction with PC. The maximum count rate was approximately 300 cps (counts per second) with energy widths of 2.0 keV, and energy-discrimination CT was carried out with a photon-energy resolution of 0.15 keV. To perform iodine K-edge CT, X-ray photons with an energy range from 33.2 to 35.2 keV were used. Next, to carry out cerium K-edge CT, an energy range from 40.3 to 42.3 keV was selected.

  11. Depletion of Intense Fields

    NASA Astrophysics Data System (ADS)

    Seipt, D.; Heinzl, T.; Marklund, M.; Bulanov, S. S.

    2017-04-01

    The interaction of charged particles and photons with intense electromagnetic fields gives rise to multiphoton Compton and Breit-Wheeler processes. These are usually described in the framework of the external field approximation, where the electromagnetic field is assumed to have infinite energy. However, the multiphoton nature of these processes implies the absorption of a significant number of photons, which scales as the external field amplitude cubed. As a result, the interaction of a highly charged electron bunch with an intense laser pulse can lead to significant depletion of the laser pulse energy, thus rendering the external field approximation invalid. We provide relevant estimates for this depletion and find it to become important in the interaction between fields of amplitude a0˜1 03 and electron bunches with charges of the order of 10 nC.

  12. Quasar 2175 Å dust absorbers - I. Metallicity, depletion pattern and kinematics

    NASA Astrophysics Data System (ADS)

    Ma, Jingzhe; Ge, Jian; Zhao, Yinan; Prochaska, J. Xavier; Zhang, Shaohua; Ji, Tuo; Schneider, Donald P.

    2017-12-01

    We present 13 new 2175 Å dust absorbers at zabs = 1.0-2.2 towards background quasars from the Sloan Digital Sky Survey. These absorbers are examined in detail using data from the Echelle Spectrograph and Imager (ESI) on the Keck II telescope. Many low-ionization lines including Fe ii, Zn ii, Mg ii, Si ii, Al ii, Ni ii, Mn ii, Cr ii, Ti ii and Ca ii are present in the same absorber that gives rise to the 2175 Å bump. The relative metal abundances (with respect to Zn) demonstrate that the depletion patterns of our 2175 Å dust absorbers resemble that of the Milky Way clouds although some are disc-like and some are halo-like. The 2175 Å dust absorbers have significantly higher depletion levels compared to literature damped Lyman α absorbers (DLAs) and sub-DLAs. The dust depletion level indicator [Fe/Zn] tends to anticorrelate with bump strengths. The velocity profiles from the Keck/ESI spectra also provide kinematical information on the dust absorbers. The dust absorbers are found to have multiple velocity components with velocity widths extending from ˜100 to ˜600 km s-1, which are larger than those of most DLAs and sub-DLAs. Assuming the velocity width is a reliable tracer of stellar mass, the host galaxies of 2175 Å dust absorbers are expected to be more massive than DLA/sub-DLA hosts. Not all of the 2175 Å dust absorbers are intervening systems towards background quasars. The absorbers towards quasars J1006+1538 and J1047+3423 are proximate systems that could be associated with the quasar itself or the host galaxy.

  13. Depleted uranium management alternatives

    SciTech Connect

    Hertzler, T.J.; Nishimoto, D.D.

    1994-08-01

    This report evaluates two management alternatives for Department of Energy depleted uranium: continued storage as uranium hexafluoride, and conversion to uranium metal and fabrication to shielding for spent nuclear fuel containers. The results will be used to compare the costs with other alternatives, such as disposal. Cost estimates for the continued storage alternative are based on a life-cycle of 27 years through the year 2020. Cost estimates for the recycle alternative are based on existing conversion process costs and Capital costs for fabricating the containers. Additionally, the recycle alternative accounts for costs associated with intermediate product resale and secondary waste disposal for materials generated during the conversion process.

  14. Tank depletion flow controller

    DOEpatents

    Georgeson, Melvin A.

    1976-10-26

    A flow control system includes two bubbler tubes installed at different levels within a tank containing such as radioactive liquid. As the tank is depleted, a differential pressure transmitter monitors pressure differences imparted by the two bubbler tubes at a remote, shielded location during uniform time intervals. At the end of each uniform interval, balance pots containing a dense liquid are valved together to equalize the pressures. The resulting sawtooth-shaped signal generated by the differential pressure transmitter is compared with a second sawtooth signal representing the desired flow rate during each time interval. Variations in the two signals are employed by a control instrument to regulate flow rate.

  15. Dependence of equilibrium stacking fault width on thickness of Cu thin films: A molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Rohith, P.; Sainath, G.; Choudhary, B. K.

    2017-05-01

    In face centered cubic systems, due to decrease in energy all perfect dislocations dissociates into two Shockley partials separated by stacking fault width. The stacking fault width, which influences the deformation behavior depends on many factors such as composition, stacking fault energy, temperature, surface energy and applied stress. Additionally in thin films, thickness also influences the stacking fault width of dissociated dislocations. In this paper, we investigate the effect of thin film thickness on stacking fault width in Cu using molecular dynamics simulations. The results indicate that with increase in film thickness from 1.25 nm to 11 nm, the stacking fault width increases from 1.6 nm to 3.12 nm. A bi-linear behavior has been observed. Above 11 nm thickness, the width of stacking fault has attained a saturation at higher thickness. This thickness dependent dissociation has been explained using the concept of image dislocations and associated image forces.

  16. Red cell distribution width and nonalcoholic steatohepatitis

    PubMed Central

    Gulcan Kurt, Yasemin; Cayci, Tuncer; Aydin, Fevzi Nuri; Agilli, Mehmet

    2014-01-01

    Red cell distribution width is a measure of deviation of the volume of red blood cells. It is a marker of anisocytosis and often used to evaluate the possible causes of anemia. Elevated red cell distribution width levels are also associated with acute and chronic inflammatory responses. In nonalcoholic steatohepatitis, inflammation is accompanied with steatosis. For assuming red cell distribution width as a marker of nonalcoholic steatohepatitis, intervening factors such as levels of inflammatory markers should also be evaluated. PMID:25473202

  17. Width Criterion For Weld-Seam-Tracking Data

    NASA Technical Reports Server (NTRS)

    Lincir, Mark R.

    1993-01-01

    Image-processing algorithm in "through-torch-vision" (T3V) system developed to guide gas/tungsten arc welding robot along weld seam modified, according to proposal, reducing incidence of inaccurate tracking of weld seam. Developmental system intended to provide closed-loop control of motion of welding robot along weld seam on basis of lines in T3V image identified by use of image-processing algorithm and assumed to coincide with edges of weld seam. Use of width criterion prevents tracking of many false pairs of lines, with consequent decrease in incidence of inaccurate tracking and increase in confidence in weld-tracking capability of robotic welding system.

  18. Depletion of intense fields

    NASA Astrophysics Data System (ADS)

    Bulanov, S. S.; Seipt, D.; Heinzl, T.; Marklund, M.

    2017-03-01

    The problem of backreaction of quantum processes on the properties of the background field still remains on the list of outstanding questions of high intensity particle physics. Usually, photon emission by an electron or positron, photon decay into electron-positron pairs in strong electromagnetic fields, or electron-positron pair production by such fields are described in the framework of the external field approximation. It is assumed that the external field has infinite energy and is not affected by these processes. However, the above-mentioned processes have a multi-photon nature, i.e., they occur with the absorption of a significant number of field photons. As a result, the interaction of an intense electromagnetic field with either a highly charged electron bunch or a fast growing population of electrons, positrons, and gamma photons (as in the case of an electromagnetic cascade) may lead to a depletion of the field energy, thus making the external field approximation invalid. Taking the multi-photon Compton process as an example, we estimate the threshold of depletion and find it to become significant at field strengths (a0˜103) and electron bunch charge of about tens of nC.

  19. 14 CFR 121.95 - Route width.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... (a) Approved routes and route segments over U.S. Federal airways or foreign airways (and advisory... designated width of those airways or routes. Whenever the Administrator finds it necessary to determine the width of other approved routes, he considers the following: (1) Terrain clearance. (2) Minimum en route...

  20. 14 CFR 121.95 - Route width.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... (a) Approved routes and route segments over U.S. Federal airways or foreign airways (and advisory... designated width of those airways or routes. Whenever the Administrator finds it necessary to determine the width of other approved routes, he considers the following: (1) Terrain clearance. (2) Minimum en route...

  1. 14 CFR 121.95 - Route width.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... (a) Approved routes and route segments over U.S. Federal airways or foreign airways (and advisory... designated width of those airways or routes. Whenever the Administrator finds it necessary to determine the width of other approved routes, he considers the following: (1) Terrain clearance. (2) Minimum en route...

  2. 14 CFR 121.95 - Route width.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... (a) Approved routes and route segments over U.S. Federal airways or foreign airways (and advisory... designated width of those airways or routes. Whenever the Administrator finds it necessary to determine the width of other approved routes, he considers the following: (1) Terrain clearance. (2) Minimum en route...

  3. 14 CFR 121.95 - Route width.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... (a) Approved routes and route segments over U.S. Federal airways or foreign airways (and advisory... designated width of those airways or routes. Whenever the Administrator finds it necessary to determine the width of other approved routes, he considers the following: (1) Terrain clearance. (2) Minimum en route...

  4. Ozone Depletion by Hydrofluorocarbons

    NASA Astrophysics Data System (ADS)

    Hurwitz, M.; Fleming, E. L.; Newman, P. A.; Li, F.; Mlawer, E. J.; Cady-Pereira, K. E.; Bailey, R.

    2015-12-01

    Hydrofluorocarbons (HFCs) are second-generation replacements for the chlorofluorocarbons (CFCs), halons and other substances that caused the 'ozone hole'. Atmospheric concentrations of HFCs are projected to increase dramatically in the coming decades. Coupled chemistry-climate simulations forced by these projections show that HFCs will impact the global atmosphere in 2050. As strong radiative forcers, HFCs modulate atmospheric temperature, thereby changing ozone-destroying catalytic cycles and enhancing the stratospheric circulation. These changes lead to a weak depletion of stratospheric ozone. Sensitivity simulations with the NASA Goddard Space Flight Center (GSFC) 2D model show that HFC-125 is the most important contributor to atmospheric change in 2050, as compared with HFC-23, HFC-32, HFC-134a and HFC-143a. Incorporating the interactions between chemistry, radiation and dynamics, for a likely 2050 climate, ozone depletion potentials (ODPs) for HFCs range from 4.3x10-4 to 3.5x10-2; previously HFCs were assumed to have negligible ODPs since these species lack chlorine or bromine atoms. The ozone impacts of HFCs are further investigated with the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM). The GEOSCCM is a three-dimensional, fully coupled ocean-atmosphere model with interactive stratospheric chemistry. Sensitivity simulations in which CO2, CFC-11 and HCFC-22 are enhanced individually are used as proxies for the atmospheric response to the HFC concentrations expected by the mid-21st century. Sensitivity simulations provide quantitative estimates of the impacts of these greenhouse gases on global total ozone, and can be used to assess their effects on the recovery of Antarctic ozone.

  5. The Nature of High Equivalent Width Lyman-α Galaxies

    NASA Astrophysics Data System (ADS)

    Finkelstein, S. L.; Rhoads, J. E.; Malhotra, S.; Pirzkal, N.; Wang, J.

    2005-12-01

    We present new results on the nature of the high equivalent width Lyα lines seen in high-redshift galaxies. These galaxies were identified on the basis of their large equivalent width Lyα emission, beyond the maximum expected for normal stellar populations. To be produced, this strong Lyα emission requires a strong ionizing continuum. Previous X-ray images and optical spectra show that this emission is not powered by active galactic nuclei. The optical colors of these galaxies provide a diagnostic of the stellar populations. The large equivalent widths seen in the Lyα line in these galaxies could be produced via star formation if the stellar photospheres are hotter than normal, which might be expected for star formation in low metallicity galaxies. They could also result from a top-heavy initial mass function. Both of these scenarios might be expected in primitive galaxies. To investigate these galaxies, we have computed stellar population models using the stellar population synthesis code created by Bruzual and Charlot (2003). We will use these models to predict the equivalent width distribution of the Lyα line in these high-redshift galaxies. We will also be able to derive estimates of stellar masses and stellar population ages, and be able to determine if these systems are indeed young and relatively primitive. Furthermore, we are obtaining new deep broadband imaging data on high-redshift galaxies taken from the Large Area Lyman Alpha (LALA) survey. These observations will yield better equivalent width measurements and continuum colors than previous data has allowed. We will compare these colors with the expectations for hot stars. We will also be able to constrain the star-formation rate using the UV continuum light from these galaxies, which will provide a valuable comparison with star-formation rates derived from the Lyα luminosity alone.

  6. Critical comparison of Kramers' fission width with the stationary width from the Langevin equation

    SciTech Connect

    Sadhukhan, Jhilam; Pal, Santanu

    2009-06-15

    It is shown that Kramers' fission width, originally derived for a system with constant inertia, can be extended to systems with a deformation-dependent collective inertia, which is the case for nuclear fission. The predictions of Kramers' width for systems with variable inertia are found to be in very good agreement with the stationary fission widths obtained by solving the corresponding Langevin equations.

  7. Use of the Acoustic Shadow Width to Determine Kidney Stone Size with Ultrasound.

    PubMed

    Dunmire, Barbrina; Harper, Jonathan D; Cunitz, Bryan W; Lee, Franklin C; Hsi, Ryan; Liu, Ziyue; Bailey, Michael R; Sorensen, Mathew D

    2016-01-01

    Ultrasound is known to overestimate kidney stone size. We explored measuring the acoustic shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy. A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the acoustic shadow were measured by 4 operators blinded to the true size of the stone. Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p <0.001) while the sizing error based on the shadow width was independent of depth. Shadow width was a more accurate measure of true stone size than a direct measurement of the stone in the ultrasound image (p <0.0001). The ultrasound imaging modality also impacted the measurement accuracy. All methods performed similarly for shadow size while harmonic imaging was the most accurate stone size modality. Overall 78% of the shadow sizes were accurate to within 1 mm, which is similar to the resolution obtained with clinical computerized tomography. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  8. Terrace width variations in complex lunar craters

    NASA Technical Reports Server (NTRS)

    Pearce, Steven J.; Melosh, H. J.

    1986-01-01

    The widths of terrace structures in complex craters on the moon are compared to existing theoretical models of their origin. Terrace widths in an individual crater increase monotonically outward toward the crater rim. Similarly, the width W of the terraces lying closest to the rim of a crater of diameter D increases monotonically, obeying a least-squares power-law relation WS (km) = 0.09D exp 0.87 km). A simple model of slumping that ignores inertial forces and assumes a constant bedrock yield strength is in good agreement with the observations.

  9. 12. VIEW OF DEPLETED URANIUM INGOT AND MOLDS. DEPLETED URANIUM ...

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

    12. VIEW OF DEPLETED URANIUM INGOT AND MOLDS. DEPLETED URANIUM CASTING OPERATIONS CEASED IN 1988. (11/14/57) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

  10. Estimation of error in bankfull width comparisons from temporally sequenced raw and corrected aerial photographs

    NASA Astrophysics Data System (ADS)

    Mount, N. J.; Louis, J.; Teeuw, R. M.; Zukowskyj, P. M.; Stott, T.

    2003-11-01

    This study investigates the propagation of error through image-to-image comparison of 285 river bankfull width measurements of the Afon Trannon, mid-Wales. Bankfull width is quantified from both aerial photographs analysed as rectified images in ERDAS Imagine OrthoMax and raw images in Paintshop Pro. A method for the robust estimation of bankfull width measurement error through temporal sequences of scanned aerial photographs is presented and the improvement in accuracy achieved using rectified imagery is quantified. Results from this study are placed in the context of previously published rates of bankfull width change, from a wide range of river scales, and the bankfull change rates for robust medium-term analysis using approximately 1:10,000 historical aerial photography are identified.

  11. Analyzing bin-width effect on the computed entropy

    NASA Astrophysics Data System (ADS)

    Purwani, Sri; Nahar, Julita; Twining, Carole

    2017-08-01

    The Shannon entropy is a mathematical expression for quantifying the amount of randomness which can be used to measure information content. It is used in objective function. Mutual Information (MI) uses Shannon entropy in order to determine shared information content of two images. The Shannon entropy, which was originally derived by Shannon in the context of lossless encoding of messages, is also used to define an optimum message length used in the Minimum Description Length (MDL) principle for groupwise registration. Majority of papers used histogram for computing MI, and hence the entropy. We therefore, aim to analyze the effect of bin-width on the computed entropy. We first derived the Shannon entropy from the integral of probability density function (pdf), and found that Gaussian has maximum entropy over all possible distribution. We also show that the entropy of the flat distribution is less than the entropy of the Gaussian distribution with the same variance. We then investigated the bin-width effect on the computed entropy, and analyzed the relationship between the computed entropy and the integral entropy when we vary bin-width, but fix variance and the number of samples. We then found that the value of the computed entropy lies within the theoretical predictions at small and large bin-widths. We also show two types of bias in entropy estimator.

  12. Depleted Uranium in Repositories

    SciTech Connect

    Haire, M.J.; Croff, A.G.

    1997-12-31

    For uranium to be useful in most fission nuclear reactors, it must be enriched (i.e. the concentration of the fissile isotope 235U must be increased). Therefore, depleted uranium (DU)-uranium which has less than naturally occurring concentrations of 235U-is a co-product of the enrichment process. Four to six tons of DU exist for every ton of fresh light water reactor fuel. There were 407,006 MgU 407,000 metric tons (t) of DU stored on U.S. Department of Energy (DOE) sites as of July 1993. If this DU were to be declared surplus, converted to a stable oxide form, and emplaced in a near surface disposal facility, the costs are estimated to be several billion dollars. However, the U.S. Nuclear Regulatory Commission has stated that near surface disposal of large quantities of DU tails is not appropriate. Thus, there is the possibility that disposition via disposal will be in a deep geological repository. One alternative that may significantly reduce the cost of DU disposition is to use it beneficially. In fact, DOE has begun the Beneficial Uses of DU Project to identify large scale uses of DU and to encourage its reuse. Several beneficial uses, many of which involve applications in the repository per se or in managing the wastes to go into the repository, are discussed in this report.

  13. Bipartite Graphs of Large Clique-Width

    NASA Astrophysics Data System (ADS)

    Korpelainen, Nicholas; Lozin, Vadim V.

    Recently, several constructions of bipartite graphs of large clique-width have been discovered in the literature. In the present paper, we propose a general framework for developing such constructions and use it to obtain new results on this topic.

  14. Comparison of tibiofemoral joint space width measurements from standing CT and fixed flexion radiography.

    PubMed

    Segal, Neil A; Frick, Eric; Duryea, Jeffrey; Nevitt, Michael C; Niu, Jingbo; Torner, James C; Felson, David T; Anderson, Donald D

    2016-08-09

    The objective of this project was to determine the relationship between medial tibiofemoral joint space width measured on fixed-flexion radiographs and the three-dimensional joint space width distribution on low-dose, standing CT (SCT) imaging. At the 84-month visit of the Multicenter Osteoarthritis Study, 20 participants were recruited. A commercial SCT scanner for the foot and ankle was modified to image knees while standing. Medial tibiofemoral joint space width was assessed on radiographs at fixed locations from 15-30% of compartment width using validated software and on SCT by mapping the distances between three-dimensional subchondral bone surfaces. Individual joint space width values from radiographs were compared with three-dimensional joint space width values from corresponding sagittal plane locations using paired t-tests and correlation coefficients. For the 4 medial-most tibiofemoral locations, radiographic joint space width values exceeded the minimal joint space width on SCT by a mean of 2.0mm and were approximately equal to the 61st percentile value of the joint space width distribution at each respective sagittal-plane location. Correlation coefficients at these locations were 0.91-0.97 and the offsets between joint space width values from radiographs and SCT measurements were consistent. There were greater offsets and variability in the offsets between modalities closer to the tibial spine. Joint space width measurements on fixed-flexion radiographs are highly correlated with three-dimensional joint space width from SCT. In addition to avoiding bony overlap obscuring the joint, a limitation of radiographs, the current study supports a role for SCT in the evaluation of tibiofemoral OA. This article is protected by copyright. All rights reserved.

  15. Lithium Depletion in the Beta Pictoris Moving Group

    NASA Astrophysics Data System (ADS)

    Yee, Jennifer C.; Jensen, E. L.; Reaser, B. E.

    2006-12-01

    We present a study of lithium depletion in twelve late-type pre-main-sequence stars in the coeval Beta Pictoris Moving Group (BPMG). The age of this group ( 12 Myr) is well constrained because all of the stars in the sample have Hipparcos distances. We have determined Li abundances for these K and M stars using equivalent width measurements of the 6707.8 Angstrom Li I line from new high-resolution, high-S/N echelle spectra, and we compare these abundances to models of pre-main-sequence Li depletion by Baraffe et al. (1998), D'Antona & Mazzitelli (1997, 1998), and Siess, Dufour, & Forestini (2000). Significantly more lithium depletion is observed in the sample than is predicted for a group of this age. In particular, the discrepancy between the predicted and the observed lithium abundances increases with decreasing effective temperature, suggesting a problem with theories describing pre-main-sequence lithium depletion. Our data indicate that M stars deplete lithium more rapidly than predicted, which could make M-type post-T-Tauri stars difficult to identify. In addition, we compare our results to the work of Song, Bessell, & Zuckerman (2002) on HIP 112312. In contrast to that work, we did not observe the lithium depletion boundary of the BPMG; none of the three M4.5 stars in the sample showed evidence of lithium (log N(Li) < -0.5), indicating a lithium depletion boundary later than M4.5, further underscoring the gap between age estimates from lithium depletion and those from theoretical evolutionary tracks. We gratefully acknowledge the support of the National Science Foundation through grant AST-0307830.

  16. The Toxicity of Depleted Uranium

    PubMed Central

    Briner, Wayne

    2010-01-01

    Depleted uranium (DU) is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a clear and defined set of symptoms. Chronic low-dose, or subacute, exposure to depleted uranium alters the appearance of milestones in developing organisms. Adult animals that were exposed to depleted uranium during development display persistent alterations in behavior, even after cessation of depleted uranium exposure. Adult animals exposed to depleted uranium demonstrate altered behaviors and a variety of alterations to brain chemistry. Despite its reduced level of radioactivity evidence continues to accumulate that depleted uranium, if ingested, may pose a radiologic hazard. The current state of knowledge concerning DU is discussed. PMID:20195447

  17. Ego depletion impairs implicit learning.

    PubMed

    Thompson, Kelsey R; Sanchez, Daniel J; Wesley, Abigail H; Reber, Paul J

    2014-01-01

    Implicit skill learning occurs incidentally and without conscious awareness of what is learned. However, the rate and effectiveness of learning may still be affected by decreased availability of central processing resources. Dual-task experiments have generally found impairments in implicit learning, however, these studies have also shown that certain characteristics of the secondary task (e.g., timing) can complicate the interpretation of these results. To avoid this problem, the current experiments used a novel method to impose resource constraints prior to engaging in skill learning. Ego depletion theory states that humans possess a limited store of cognitive resources that, when depleted, results in deficits in self-regulation and cognitive control. In a first experiment, we used a standard ego depletion manipulation prior to performance of the Serial Interception Sequence Learning (SISL) task. Depleted participants exhibited poorer test performance than did non-depleted controls, indicating that reducing available executive resources may adversely affect implicit sequence learning, expression of sequence knowledge, or both. In a second experiment, depletion was administered either prior to or after training. Participants who reported higher levels of depletion before or after training again showed less sequence-specific knowledge on the post-training assessment. However, the results did not allow for clear separation of ego depletion effects on learning versus subsequent sequence-specific performance. These results indicate that performance on an implicitly learned sequence can be impaired by a reduction in executive resources, in spite of learning taking place outside of awareness and without conscious intent.

  18. Stratospheric ozone depletion.

    PubMed

    Rowland, F Sherwood

    2006-05-29

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290-320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime-the 'Antarctic ozone hole'. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules.

  19. Stratospheric ozone depletion

    PubMed Central

    Rowland, F. Sherwood

    2006-01-01

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290–320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime—the ‘Antarctic ozone hole’. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules. PMID:16627294

  20. Comparison of standardized clinical evaluation of wounds using ruler length by width and Scout length by width measure and Scout perimeter trace.

    PubMed

    Langemo, Diane; Spahn, James; Spahn, Thomas; Pinnamaneni, V Chowdry

    2015-03-01

    The study objective was to examine precision in wound measurement using a recently Food and Drug Administration-approved Scout (WoundVision, LLC, Indianapolis, Indiana) device to measure wound length (L) and width (W). Wound perimeter and a ruler measurement of L and W were also made. Images of 40 actual patient wounds were measured using the Scout device. All 3 techniques (length, width, perimeter) demonstrated acceptable within and between reader precision; however, the best precision was in wound perimeter measurement.

  1. Background suppression in fluorescence nanoscopy with stimulated emission double depletion

    NASA Astrophysics Data System (ADS)

    Gao, Peng; Prunsche, Benedikt; Zhou, Lu; Nienhaus, Karin; Nienhaus, G. Ulrich

    2017-01-01

    Stimulated emission depletion (STED) fluorescence nanoscopy is a powerful super-resolution imaging technique based on the confinement of fluorescence emission to the central subregion of an observation volume through de-excitation of fluorophores in the periphery via stimulated emission. Here, we introduce stimulated emission double depletion (STEDD) as a method to selectively remove artificial background intensity. In this approach, a first, conventional STED pulse is followed by a second, delayed Gaussian STED pulse that specifically depletes the central region, thus leaving only background. Thanks to time-resolved detection we can remove this background intensity voxel by voxel by taking the weighted difference of photons collected before and after the second STED pulse. STEDD thus yields background-suppressed super-resolved images as well as STED-based fluorescence correlation spectroscopy data. Furthermore, the proposed method is also beneficial when considering lower-power, less redshifted depletion pulses.

  2. Hyperspectral stimulated emission depletion microscopy and methods of use thereof

    SciTech Connect

    Timlin, Jerilyn A; Aaron, Jesse S

    2014-04-01

    A hyperspectral stimulated emission depletion ("STED") microscope system for high-resolution imaging of samples labeled with multiple fluorophores (e.g., two to ten fluorophores). The hyperspectral STED microscope includes a light source, optical systems configured for generating an excitation light beam and a depletion light beam, optical systems configured for focusing the excitation and depletion light beams on a sample, and systems for collecting and processing data generated by interaction of the excitation and depletion light beams with the sample. Hyperspectral STED data may be analyzed using multivariate curve resolution analysis techniques to deconvolute emission from the multiple fluorophores. The hyperspectral STED microscope described herein can be used for multi-color, subdiffraction imaging of samples (e.g., materials and biological materials) and for analyzing a tissue by Forster Resonance Energy Transfer ("FRET").

  3. [Internal contamination with depleted uranium and health disorders].

    PubMed

    Pranjić, Nurka; Karamehić, Jasenko; Ljuca, Farid; Zigić, Zlata; Ascerić, Mensura

    2002-01-01

    In this review we used the published data on depleted uranium (experimental and epidemiological) from the current literature. Depleted uranium is a toxic heavy metal that in high dose may cause poisoning and health effects as those caused by lead, mercury, and chromium. It is slightly radioactive. The aim of this review was to select, to arrange, to present references of scientific papers, and to summarise the data in order to give a comprehensive image of the results of toxicological studies on depleted uranium that have been done on animals (including carcinogenic activity). We have also used epidemiological posted study results related to occupational and environmental exposure to depleted uranium. The toxicity of uranium has been studied extensively. The results of the studies indicated primarily its chemical toxicity, particularly renal effects, but depleted uranium is not radiological hazard. Uranium is not metal determined to be carcinogenic (the International Agency of Research on Cancer). The military use of depleted uranium will give additional insight into the toxicology of depleted uranium. The present controversy over the radiological and chemical toxicity of depleted uranium used in the Gulf War requests further experimental and clinical investigations of its effects on the biosphere and human beings.

  4. Transequatorial Propagation and Depletion Precursors

    NASA Astrophysics Data System (ADS)

    Miller, E. S.; Bust, G. S.; Kaeppler, S. R.; Frissell, N. A.; Paxton, L. J.

    2014-12-01

    The bottomside equatorial ionosphere in the afternoon and evening sector frequently evolves rapidly from smoothly stratified to violently unstable with large wedges of depleted plasma growing through to the topside on timescales of a few tens of minutes. These depletions have numerous practical impacts on radio propagation, including amplitude scintillation, field-aligned irregularity scatter, HF blackouts, and long-distance transequatorial propagation at frequencies above the MUF. Practical impacts notwithstanding, the pathways and conditions under which depletions form remain a topic of vigorous inquiry some 80 years after their first report. Structuring of the pre-sunset ionosphere---morphology of the equatorial anomalies and long-wavelength undulations of the isodensity contours on the bottomside---are likely to hold some clues to conditions that are conducive to depletion formation. The Conjugate Depletion Experiment is an upcoming transequatorial forward-scatter HF/VHF experiment to investigate pre-sunset undulations and their connection with depletion formation. We will present initial results from the Conjugate Depletion Experiment, as well as a companion analysis of a massive HF propagation data set.

  5. A TEST OF PRE-MAIN-SEQUENCE LITHIUM DEPLETION MODELS

    SciTech Connect

    Yee, Jennifer C.; Jensen, Eric L. N.

    2010-03-01

    Despite the extensive study of lithium depletion during pre-main-sequence (PMS) contraction, studies of individual stars show discrepancies between ages determined from the Hertzsprung-Russell (H-R) diagram and ages determined from lithium depletion, indicating open questions in the PMS evolutionary models. To further test these models, we present high-resolution spectra for members of the beta Pictoris Moving Group (BPMG), which is young and nearby. We measure equivalent widths of the 6707.8 A Li I line in these stars and use them to determine lithium abundances. We combine the lithium abundance with the predictions of PMS evolutionary models in order to calculate a lithium depletion age for each star. We compare this age to the age predicted by the H-R diagram of the same model. We find that the evolutionary models underpredict the amount of lithium depletion for the BPMG given its nominal H-R diagram age of {approx}12 Myr, particularly for the mid-M stars, which have no observable Li I line. This results in systematically older ages calculated from lithium depletion isochrones than from the H-R diagram. We suggest that this discrepancy may be related to the discrepancy between measured M-dwarf radii and the smaller radii predicted by evolutionary models.

  6. Stimulated emission depletion microscopy with optical fibers

    NASA Astrophysics Data System (ADS)

    Yan, Lu

    Imaging at the nanoscale and/or at remote locations holds great promise for studies in fields as disparate as the life sciences and materials sciences. One such microscopy technique, stimulated emission depletion (STED) microscopy, is one of several fluorescence based imaging techniques that offers resolution beyond the diffraction-limit. All current implementations of STED microscopy, however, involve the use of free-space beam shaping devices to achieve the Gaussian- and donut-shaped Orbital Angular Momentum (OAM) carrying beams at the desired colors -- a challenging prospect from the standpoint of device assembly and mechanical stability during operation. A fiber-based solution could address these engineering challenges, and perhaps more interestingly, it may facilitate endoscopic implementation of in vivo STED imaging, a prospect that has thus far not been realized because optical fibers were previously considered to be incapable of transmitting the OAM beams that are necessary for STED. In this thesis, we investigate fiber-based STED systems to enable endoscopic nanoscale imaging. We discuss the design and characteristics of a novel class of fibers supporting and stably propagating Gaussian and OAM modes. Optimization of the design parameters leads to stable excitation and depletion beams propagating in the same fiber in the visible spectral range, for the first time, with high efficiency (>99%) and mode purity (>98%). Using the fabricated vortex fiber, we demonstrate an all-fiber STED system with modes that are tolerant to perturbations, and we obtain naturally self-aligned PSFs for the excitation and depletion beams. Initial experiments of STED imaging using our device yields a 4-fold improvement in lateral resolution compared to confocal imaging. In an experiment in parallel, we show the means of using q-plates as free-space mode converters that yield alignment tolerant STED microscopy systems at wavelengths covering the entire visible spectrum, and hence

  7. Relative Width and Height of Handwritten Letter.

    PubMed

    Lizega Rika, Joseba

    2017-02-28

    This is an exploratory study that analyzes the width and the height of letters in two texts written by each of the 21 writers analyzed. After detrending the linear, text, and allograph trends, we proceeded to comparing the sizes obtained in different texts. The different detrended series were compared by means of correlation and t-test. According to the results regarding the width of letters, the texts of 19 of 21 writers correlated strongly, whereas the texts of two writers did not correlate with the limits of the threshold. With regard to the height of letters, texts written by between 18 and 21 writers of 21 writers correlated strongly, whereas texts that did not correlate were within the threshold value. Regarding both the width and the height of letters, of 21 writers, texts written by between 19 and 21 individuals were found to correlate strongly.

  8. The Variable Line Width of Achernar

    NASA Astrophysics Data System (ADS)

    Rivinius, Th.; Townsend, R. H. D.; Baade, D.; Carciofi, A. C.; Leister, N.; Štefl, S.

    2016-11-01

    Spectroscopic observations of Achernar over the past decades, have shown the photospheric line width, as measured by the rotational parameter v sin i, to vary in correlation with the emission activity. Here we present new observations, covering the most recent activity phase, and further archival data collected from the archives. The v sin i variation is confirmed. On the basis of the available data it cannot be decided with certainty whether the increased line width precedes the emission activity, i.e. is a signature of the ejection mechanism, or postdates it, which would make it a signature of re-accretion of some of the disk-material. However, the observed evidence leans towards the re-accretion hypothesis. Two further stars showing the effect of variable line width in correlation with emission activity, namely 66 Oph and π Aqr, are presented as well.

  9. Equivalent Widths in the Spectrum of Sirius

    NASA Astrophysics Data System (ADS)

    Zhao, G.; Qiu, H. M.; Chen, Y. Q.; Li, Z. W.

    2000-02-01

    The equivalent widths of total 546 lines (26 elements are included) in the spectrum of the bright Am star Sirius from 380 to 930 nm are tabulated. The high-resolution, high signal-to-noise ratio spectrum was obtained with the Coudé Echelle Spectrograph attached to the 2.16 m telescope at Beijing Astronomical Observatory (Xinglong, China). Here we also give the results of the equivalent widths comparison between our measurements and those of Strom et al. and Sadakane & Ueta.

  10. Ego Depletion Impairs Implicit Learning

    PubMed Central

    Thompson, Kelsey R.; Sanchez, Daniel J.; Wesley, Abigail H.; Reber, Paul J.

    2014-01-01

    Implicit skill learning occurs incidentally and without conscious awareness of what is learned. However, the rate and effectiveness of learning may still be affected by decreased availability of central processing resources. Dual-task experiments have generally found impairments in implicit learning, however, these studies have also shown that certain characteristics of the secondary task (e.g., timing) can complicate the interpretation of these results. To avoid this problem, the current experiments used a novel method to impose resource constraints prior to engaging in skill learning. Ego depletion theory states that humans possess a limited store of cognitive resources that, when depleted, results in deficits in self-regulation and cognitive control. In a first experiment, we used a standard ego depletion manipulation prior to performance of the Serial Interception Sequence Learning (SISL) task. Depleted participants exhibited poorer test performance than did non-depleted controls, indicating that reducing available executive resources may adversely affect implicit sequence learning, expression of sequence knowledge, or both. In a second experiment, depletion was administered either prior to or after training. Participants who reported higher levels of depletion before or after training again showed less sequence-specific knowledge on the post-training assessment. However, the results did not allow for clear separation of ego depletion effects on learning versus subsequent sequence-specific performance. These results indicate that performance on an implicitly learned sequence can be impaired by a reduction in executive resources, in spite of learning taking place outside of awareness and without conscious intent. PMID:25275517

  11. "When the going gets tough, who keeps going?" Depletion sensitivity moderates the ego-depletion effect.

    PubMed

    Salmon, Stefanie J; Adriaanse, Marieke A; De Vet, Emely; Fennis, Bob M; De Ridder, Denise T D

    2014-01-01

    Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In three studies, we assessed individual differences in depletion sensitivity, and demonstrate that depletion sensitivity moderates ego-depletion effects. The Depletion Sensitivity Scale (DSS) was employed to assess depletion sensitivity. Study 1 employs the DSS to demonstrate that individual differences in sensitivity to ego-depletion exist. Study 2 shows moderate correlations of depletion sensitivity with related self-control concepts, indicating that these scales measure conceptually distinct constructs. Study 3 demonstrates that depletion sensitivity moderates the ego-depletion effect. Specifically, participants who are sensitive to depletion performed worse on a second self-control task, indicating a stronger ego-depletion effect, compared to participants less sensitive to depletion.

  12. Characterizing Fluoroscopy Based Kinematic Accuracy as a Function of Pulse Width and Velocity

    PubMed Central

    Ellingson, Arin M.; Mozingo, Joseph D.; Magnuson, Dixon J.; Pagnano, Mark W.; Zhao, Kristin D.

    2016-01-01

    Fluoroscopic imaging has become increasingly popular to investigate total knee arthroplasty kinematics non-invasively - 3D implant models are aligned with 2D image projections, and optimized via an edge-contour alignment technique. Previous studies have quantified the accuracy of this approach, however they do not adequately address the impact of image collection parameters. A particularly sensitive parameter is the pulse width, or exposure time per frame At longer pulse widths, a more motion is captured in a single frame; this can lead to image blur and subsequent degradation to image edge quality. Therefore, the comparative accuracy of relative joint kinematics as a function of pulse width and joint velocity needs to be defined. A limits of agreement approach was taken to define the mean differences between optoelectric kinematic measures (gold standard) and fluoroscopic methods at various pulse widths (1, 8, 16ms) and knee velocities (50, 100, 225°/s). The mean absolute differences between the optoelectric and fluoroscopic methods for 1ms pulse width was less than 1.5° and 0.9mm. Comparable rotational differences (1.3°) were observed for the 8ms pulse width but had larger translational differences (1.4mm). The 16ms pulse width yielded the greatest mean differences (2.0° and 1.6mm), which increased with knee flexion velocity. The importance of pulse width and velocity should not be overlooked for future studies - this parameter has proven to be a sensitive metric in the quantification of joint motion via fluoroscopy and must be identified and reported in future studies. PMID:27769514

  13. Commercialisation of full depletion scientific CCDs

    NASA Astrophysics Data System (ADS)

    Jorden, Paul; Ball, Kevin; Bell, Ray; Burt, David; Guyatt, Neil; Hadfield, Kevin; Jerram, Paul; Pool, Peter; Pike, Andrew; Holland, Andrew; Murray, Neil

    2006-06-01

    Following successful manufacture of small-format trial devices we have now designed and manufactured large-format scientific CCDs in high resistivity silicon ('high-rho'). These devices are intended for 'full depletion' operation as backside illuminated sensors for very high red wavelength sensitivity and X-ray imaging spectroscopy at extended energies. Devices of 2k*512 and 2k*4k format, with both single and dual stage output circuits have been manufactured and tested. Design considerations, test results, and commercial manufacturing considerations will be addressed.

  14. An efficient algorithm for equal width

    NASA Astrophysics Data System (ADS)

    Bakodah, Huda. O.; Banaja, Mona. A.

    2016-10-01

    The new modification of Laplace Adomian decomposition method (ADM) to obtain numerical solution of the equal width equation is presented. The performance of the method illustrated by solving some test examples of the problem. By computing the absolute error the results are found in good agreement with exact solution.

  15. Bounding the Higgs boson width through interferometry.

    PubMed

    Dixon, Lance J; Li, Ye

    2013-09-13

    We study the change in the diphoton-invariant-mass distribution for Higgs boson decays to two photons, due to interference between the Higgs resonance in gluon fusion and the continuum background amplitude for gg→γγ. Previously, the apparent Higgs mass was found to shift by around 100 MeV in the standard model in the leading-order approximation, which may potentially be experimentally observable. We compute the next-to-leading-order QCD corrections to the apparent mass shift, which reduce it by about 40%. The apparent mass shift may provide a way to measure, or at least bound, the Higgs boson width at the Large Hadron Collider through "interferometry." We investigate how the shift depends on the Higgs width, in a model that maintains constant Higgs boson signal yields. At Higgs widths above 30 MeV, the mass shift is over 200 MeV and increases with the square root of the width. The apparent mass shift could be measured by comparing with the ZZ* channel, where the shift is much smaller. It might be possible to measure the shift more accurately by exploiting its strong dependence on the Higgs transverse momentum.

  16. Depleting depletion: Polymer swelling in poor solvent mixtures

    NASA Astrophysics Data System (ADS)

    Mukherji, Debashish; Marques, Carlos; Stuehn, Torsten; Kremer, Kurt

    A polymer collapses in a solvent when the solvent particles dislike monomers more than the repulsion between monomers. This leads to an effective attraction between monomers, also referred to as depletion induced attraction. This attraction is the key factor behind standard polymer collapse in poor solvents. Strikingly, even if a polymer exhibits poor solvent condition in two different solvents, it can also swell in mixtures of these two poor solvents. This collapse-swelling-collapse scenario is displayed by poly(methyl methacrylate) (PMMA) in aqueous alcohol. Using molecular dynamics simulations of a thermodynamically consistent generic model and theoretical arguments, we unveil the microscopic origin of this phenomenon. Our analysis suggests that a subtle interplay of the bulk solution properties and the local depletion forces reduces depletion effects, thus dictating polymer swelling in poor solvent mixtures.

  17. High-resolution three-dimensional imaging of a depleted CMOS sensor using an edge Transient Current Technique based on the Two Photon Absorption process (TPA-eTCT)

    NASA Astrophysics Data System (ADS)

    García, Marcos Fernández; Sánchez, Javier González; Echeverría, Richard Jaramillo; Moll, Michael; Santos, Raúl Montero; Moya, David; Pinto, Rogelio Palomo; Vila, Iván

    2017-02-01

    For the first time, the deep n-well (DNW) depletion space of a High Voltage CMOS sensor has been characterized using a Transient Current Technique based on the simultaneous absorption of two photons. This novel approach has allowed to resolve the DNW implant boundaries and therefore to accurately determine the real depleted volume and the effective doping concentration of the substrate. The unprecedented spatial resolution of this new method comes from the fact that measurable free carrier generation in two photon mode only occurs in a micrometric scale voxel around the focus of the beam. Real three-dimensional spatial resolution is achieved by scanning the beam focus within the sample.

  18. Charge depletion in organic heterojunction

    NASA Astrophysics Data System (ADS)

    Ng, T. W.; Lo, M. F.; Lee, S. T.; Lee, C. S.

    2012-03-01

    Until now two types of organic-organic heterojunction (OHJ) have been observed in P-N junctions formed between undoped-organic semiconductors. Charge-transfers across OHJs are either negligible or showing electron transfer from P-type to N-type materials, leading to charges accumulation near the interface. Here, we observed that junction of 4,4',4''-tris(2-methylphenyl-phenylamino)triphenylamine (m-MTDATA)/bathocuproine (BCP) show the third-behavior. Electrons in BCP (N-type) transfer to m-MTDATA (P-type), leading to depletion of mobile majority carriers near the junction. While "depletion junctions" are typical in inorganic semiconductors, there are no reports in undoped-OHJ. Formation mechanism of depletion OHJs and fundamental differences between inorganic and organic HJs are discussed.

  19. K- nuclear states: Binding energies and widths

    NASA Astrophysics Data System (ADS)

    Hrtánková, J.; Mareš, J.

    2017-07-01

    K- optical potentials relevant to calculations of K- nuclear quasibound states were developed within several chiral meson-baryon coupled-channels interaction models. The applied models yield quite different K- binding energies and widths. Then the K- multinucleon interactions were incorporated by a phenomenological optical potential fitted recently to kaonic atom data. Though the applied K- interaction models differ significantly in the K-N subthreshold region, our self-consistent calculations of kaonic nuclei across the periodic table lead to conclusions valid quite generally. Due to K- multinucleon absorption in the nuclear medium, the calculated widths of K- nuclear states are sizable, ΓK-≥90 MeV, and exceed substantially their binding energies in all considered nuclei.

  20. Gain depletion of X-ray framing camera

    NASA Astrophysics Data System (ADS)

    Koga, M.; Shiraga, H.

    2017-08-01

    X-ray imaging is very useful to investigate imploded core plasma in inertial fusion experiments. We can obtain information from X-ray images, such as shape, density, and temperature. An X-ray framing camera (XFC) capable of taking two-dimensional, time-resolved X-ray images is used to capture the images. In previous work, we developed a numerical model of an XFC to analyze its X-ray image. The calculated results agreed qualitatively with experimental results. However, it was not accurate enough to determine the absolute value of the signal. We thought this discrepancy was caused by gain depletion. In high energy laser experiments, high photon flux may cause gain depletion. This is a problem for accurate X-ray measurement. In this paper, we report our new model, including gain depletion. The new model is evaluated by tabletop laser experiments and high energy laser experiments. The results calculated using the new model agree quantitatively with our experimental results. Furthermore, we confirmed that gain depletion occurs in our high energy laser experiments. For quantitatively accurate X-ray intensity measurements, the XFC should be used with limited incident photon flux such that the gain linearity is guaranteed.

  1. Testing Computability by Width Two OBDDs

    NASA Astrophysics Data System (ADS)

    Ron, Dana; Tsur, Gilad

    Property testing is concerned with deciding whether an object (e.g. a graph or a function) has a certain property or is “far” (for some definition of far) from every object with that property. In this paper we give lower and upper bounds for testing functions for the property of being computable by a read-once width-2 Ordered Binary Decision Diagram (OBDD), also known as a branching program, where the order of the variables is known. Width-2 OBDDs generalize two classes of functions that have been studied in the context of property testing - linear functions (over GF(2)) and monomials. In both these cases membership can be tested in time that is linear in 1/ɛ. Interestingly, unlike either of these classes, in which the query complexity of the testing algorithm does not depend on the number, n, of variables in the tested function, we show that (one-sided error) testing for computability by a width-2 OBDD requires Ω(log(n)) queries, and give an algorithm (with one-sided error) that tests for this property and performs tilde{O}(log(n)/ɛ) queries.

  2. Effect of pump depletion and cross-focusing on twisted terahertz radiation generation

    NASA Astrophysics Data System (ADS)

    Sobhani, Hassan; Dehghan, Mehdi; Dadar, Elham

    2017-02-01

    In this paper, the pump depletion and cross-focusing effects on the generation of twisted terahertz radiation are investigated. Based on the beating of two Laguerre-Gaussian lasers in a radial plasma channel, a twisted terahertz radiation can be produced. In the presence of pump depletion, the lasers power is consumed. So, the ponderomotive force nonlinearity decreases and the output terahertz field approaches to a saturation value. Under competition between the diffraction and nonlinearity effects, the amplitude of laser beam width oscillation grows. When the incident laser beams have non-similar topological charge numbers, the normalized generated terahertz amplitude is low and the pump depletion effect on the laser beam width evolution is ignorable.

  3. LADAR Range Image Interpolation Exploiting Pulse Width Expansion

    DTIC Science & Technology

    2012-03-22

    33 3.2. The Gaussian beam upon exiting the laser cavity of the LADAR. 35 3.3. Two Gaussian beams with different beam waists ...g(x, y), is normalized so that the double summation of the squared field is equal to one. The variable ωo is the beam waist , which is described next...Beam waist is a characteristic that is essential in describing a Gaussian beam. The beam waist , represented by ωo in Equation (2.3), describes the

  4. IMAGE EUV Observations and Modeling of the Plasmaspheric Density Trough Associated with the 24 May 2000 Geomagnetic Storm

    NASA Technical Reports Server (NTRS)

    Adrian, M.L.; Gallagher, D. L.; Green, J. L.; Sandel, B. R.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    The IMAGE EUV imager observed a plasmaspheric density trough in association with a geomagnetically active period on 24 May 2000. At EUV wavelengths, this density trough appeared as an Archimedes spiral extending from Earth's shadow to approximately 1800 MLT. We present an analysis of this density trough using simulated EUV images. Observational EUV images are subjected to edge analysis to establish the plasmapause L-shell and the location of the density trough in terms of L-shell, MLT extent, and radial width. The plasmaspheric density distribution is modeled using both static and dynamic models for the plasmasphere. The background plasmasphere is then numerically simulated using the 4-parameter plasmaspheric density model contained within the Global Core Plasma Model (GCPM) [Gallagher et al., 20001 and the Dynamic Global Core Plasma Model (DGCPM). Simulated EUV images of the model plasmasphere are produced once an artificial density depletion, matching the observed MLT extent and width, has been removed. Once the azimuthal extent and width of the trough have been simulated, the depth of the artificial density depletion is iteratively adjusted to produce simulated EUV images that approximate observation. The results of this analysis and discussion of possible origins for this density trough will be presented.

  5. IMAGE EUV Observations and Modeling of the Plasmaspheric Density Trough Associated with the 24 May 2000 Geomagnetic Storm

    NASA Technical Reports Server (NTRS)

    Adrian, M.L.; Gallagher, D. L.; Green, J. L.; Sandel, B. R.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    The IMAGE EUV imager observed a plasmaspheric density trough in association with a geomagnetically active period on 24 May 2000. At EUV wavelengths, this density trough appeared as an Archimedes spiral extending from Earth's shadow to approximately 1800 MLT. We present an analysis of this density trough using simulated EUV images. Observational EUV images are subjected to edge analysis to establish the plasmapause L-shell and the location of the density trough in terms of L-shell, MLT extent, and radial width. The plasmaspheric density distribution is modeled using both static and dynamic models for the plasmasphere. The background plasmasphere is then numerically simulated using the 4-parameter plasmaspheric density model contained within the Global Core Plasma Model (GCPM) [Gallagher et al., 20001 and the Dynamic Global Core Plasma Model (DGCPM). Simulated EUV images of the model plasmasphere are produced once an artificial density depletion, matching the observed MLT extent and width, has been removed. Once the azimuthal extent and width of the trough have been simulated, the depth of the artificial density depletion is iteratively adjusted to produce simulated EUV images that approximate observation. The results of this analysis and discussion of possible origins for this density trough will be presented.

  6. Artifacts for Calibration of Submicron Width Measurements

    NASA Technical Reports Server (NTRS)

    Grunthaner, Frank; Grunthaner, Paula; Bryson, Charles, III

    2003-01-01

    Artifacts that are fabricated with the help of molecular-beam epitaxy (MBE) are undergoing development for use as dimensional calibration standards with submicron widths. Such standards are needed for calibrating instruments (principally, scanning electron microscopes and scanning probe microscopes) for measuring the widths of features in advanced integrated circuits. Dimensional calibration standards fabricated by an older process that involves lithography and etching of trenches in (110) surfaces of single-crystal silicon are generally reproducible to within dimensional tolerances of about 15 nm. It is anticipated that when the artifacts of the present type are fully developed, their critical dimensions will be reproducible to within 1 nm. These artifacts are expected to find increasing use in the semiconductor-device and integrated- circuit industries as the width tolerances on semiconductor devices shrink to a few nanometers during the next few years. Unlike in the older process, one does not rely on lithography and etching to define the critical dimensions. Instead, one relies on the inherent smoothness and flatness of MBE layers deposited under controlled conditions and defines the critical dimensions as the thicknesses of such layers. An artifact of the present type is fabricated in two stages (see figure): In the first stage, a multilayer epitaxial wafer is grown on a very flat substrate. In the second stage, the wafer is cleaved to expose the layers, then the exposed layers are differentially etched (taking advantage of large differences between the etch rates of the different epitaxial layer materials). The resulting structure includes narrow and well-defined trenches and a shelf with thicknesses determined by the thicknesses of the epitaxial layers from which they were etched. Eventually, it should be possible to add a third fabrication stage in which durable, electronically inert artifacts could be replicated in diamondlike carbon from a master made by

  7. Computer-aided system for measuring the mandibular cortical width on panoramic radiographs in osteoporosis diagnosis

    NASA Astrophysics Data System (ADS)

    Arifin, Agus Zainal; Asano, Akira; Taguchi, Akira; Nakamoto, Takashi; Ohtsuka, Masahiko; Tanimoto, Keiji

    2005-04-01

    Osteoporotic fractures are associated with substantial morbidity, increased medical cost and high mortality risk. Several equipments of bone assessment have been developed to identify individuals, especially postmenopausal women, with high risk of osteoporotic fracture; however, a large segment of women with low skeletal bone mineral density (BMD), namely women with high risk of osteoporotic fractures, cannot be identified sufficiently because osteoporosis is asymptomatic. Recent studies have been demonstrating that mandibular inferior cortical width manually measured on panoramic radiographs may be useful for the identification of women with low BMD. Automatic measurement of cortical width may enable us to identify a large number of asymptomatic women with low BMD. The purpose of this study was to develop a computer-aided system for measuring the mandibular cortical width on panoramic radiographs. Initially, oral radiologists determined the region of interest based on the position of mental foramen. Some enhancing image techniques were applied so as to measure the cortical width at the best point. Panoramic radiographs of 100 women who had BMD assessments of the lumbar spine and femoral neck were used to confirm the efficacy of our new system. Cortical width measured with our system was compared with skeletal BMD. There were significant correlation between cortical width measured with our system and skeletal BMD. These correlations were similar with those between cortical width manually measured by the dentist and skeletal BMD. Our results suggest that our new system may be useful for mass screening of osteoporosis.

  8. Swath width study. A simulation assessment of costs and benefits of a sensor system for agricultural application

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Satellites provide an excellent platform from which to observe crops on the scale and frequency required to provide accurate crop production estimates on a worldwide basis. Multispectral imaging sensors aboard these platforms are capable of providing data from which to derive acreage and production estimates. The issue of sensor swath width was examined. The quantitative trade trade necessary to resolve the combined issue of sensor swath width, number of platforms, and their orbits was generated and are included. Problems with different swath width sensors were analyzed and an assessment of system trade-offs of swath width versus number of satellites was made for achieving Global Crop Production Forecasting.

  9. Zn2+ depletion blocks endosome fusion.

    PubMed Central

    Aballay, A; Sarrouf, M N; Colombo, M I; Stahl, P D; Mayorga, L S

    1995-01-01

    Fusion among endosomes is an important step for transport and sorting of internalized macromolecules. Working in a cell-free system, we previously reported that endosome fusion requires cytosol and ATP, and is sensitive to N-ethylmaleimide. Fusion is regulated by monomeric and heterotrimeric GTP-binding proteins. We now report that fusion can proceed at very low Ca2+ concentrations, i.e. < 30 nM. Moreover, fusion is not affected when intravesicular Ca2+ is depleted by preincubation of vesicles with calcium ionophores (5 microM ionomycin or A23187) in the presence of calcium chelators (5 mM EGTA or 60 mM EDTA). The results indicate that fusion can proceed at extremely low concentrations of intravesicular and extravesicular Ca2+. However, BAPTA [1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid], a relatively specific Ca2+ chelator, inhibits fusion. BAPTA binds other metals besides Ca2+. We present evidence that BAPTA inhibition is due not to Ca2+ chelation but to Zn2+ depletion. TPEN [N,N,N',N'-tetrakis-(2-pyridylmethyl) ethylenediamine], another metal-ion chelator with low affinity for Ca2+, also inhibited fusion. TPEN- and BAPTA-inhibited fusions were restored by addition of Zn2+. Zn(2+)-dependent fusion presents the same characteristics as control fusion. In intact cells, TPEN inhibited transport along the endocytic pathway. The results indicate that Zn2+ depletion blocks endosome fusion, suggesting that this ion is necessary for the function of one or more factors involved in the fusion process. Images Figure 1 PMID:8554539

  10. Self-regulatory depletion increases emotional reactivity in the amygdala.

    PubMed

    Wagner, Dylan D; Heatherton, Todd F

    2013-04-01

    The ability to self-regulate can become impaired when people are required to engage in successive acts of effortful self-control, even when self-control occurs in different domains. Here, we used functional neuroimaging to test whether engaging in effortful inhibition in the cognitive domain would lead to putative dysfunction in the emotional domain. Forty-eight participants viewed images of emotional scenes during functional magnetic resonance imaging in two sessions that were separated by a challenging attention control task that required effortful inhibition (depletion group) or not (control group). Compared to the control group, depleted participants showed increased activity in the left amygdala to negative but not to positive or neutral scenes. Moreover, whereas the control group showed reduced amygdala activity to all scene types (i.e. habituation), the depletion group showed increased amygdala activity relative to their pre-depletion baseline; however this was only significant for negative scenes. Finally, depleted participants showed reduced functional connectivity between the left amygdala and ventromedial prefrontal cortex during negative scene processing. These findings demonstrate that consuming self-regulatory resources leads to an exaggerated neural response to emotional material that appears specific to negatively valenced stimuli and further suggests a failure to recruit top-down prefrontal regions involved in emotion regulation.

  11. Self-regulatory depletion increases emotional reactivity in the amygdala

    PubMed Central

    Heatherton, Todd F.

    2013-01-01

    The ability to self-regulate can become impaired when people are required to engage in successive acts of effortful self-control, even when self-control occurs in different domains. Here, we used functional neuroimaging to test whether engaging in effortful inhibition in the cognitive domain would lead to putative dysfunction in the emotional domain. Forty-eight participants viewed images of emotional scenes during functional magnetic resonance imaging in two sessions that were separated by a challenging attention control task that required effortful inhibition (depletion group) or not (control group). Compared to the control group, depleted participants showed increased activity in the left amygdala to negative but not to positive or neutral scenes. Moreover, whereas the control group showed reduced amygdala activity to all scene types (i.e. habituation), the depletion group showed increased amygdala activity relative to their pre-depletion baseline; however this was only significant for negative scenes. Finally, depleted participants showed reduced functional connectivity between the left amygdala and ventromedial prefrontal cortex during negative scene processing. These findings demonstrate that consuming self-regulatory resources leads to an exaggerated neural response to emotional material that appears specific to negatively valenced stimuli and further suggests a failure to recruit top–down prefrontal regions involved in emotion regulation. PMID:22842815

  12. Pulse width modulation inverter with battery charger

    DOEpatents

    Slicker, James M.

    1985-01-01

    An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .theta., where .theta. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.

  13. Finite width of quasistatic shear bands.

    PubMed

    Jagla, E A

    2008-08-01

    I study the average deformation rate of an amorphous material submitted to an external uniform shear strain rate, in the geometry known as the split-bottom configuration. The material is described using a stochastic model of plasticity at a mesoscopic scale. A shear band is observed to start at the split point at the bottom, and widen progressively towards the surface. In a two-dimensional geometry the average statistical properties of the shear band look similar to those of the directed polymer model. In particular, the surface width of the shear band is found to scale with the system height H as H;{alpha} with alpha=0.68+/-0.02 . In more realistic three-dimensional simulations the exponent changes to alpha=0.60+/-0.02 and the bulk profile of the width of the shear band is closer to a quarter of a circle, as it was observed to be the case in recent simulations of granular materials.

  14. Pulse width modulation inverter with battery charger

    NASA Technical Reports Server (NTRS)

    Slicker, James M. (Inventor)

    1985-01-01

    An inverter is connected between a source of DC power and a three-phase AC induction motor, and a microprocessor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .theta., where .theta. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands for electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a flyback DC-DC converter circuit for recharging the battery.

  15. Optical antennas with sinusoidal modulation in width.

    PubMed

    Dikken, Dirk Jan; Segerink, Frans B; Korterik, Jeroen P; Pfaff, Stefan S; Prangsma, Jord C; Herek, Jennifer L

    2016-08-08

    Small metal structures sustaining plasmon resonances in the optical regime are of great interest due to their large scattering cross sections and ability to concentrate light to subwavelength volumes. In this paper, we study the dipolar plasmon resonances of optical antennas with a constant volume and a sinusoidal modulation in width. We experimentally show that by changing the phase of the width-modulation, with a small 10 nm modulation amplitude, the resonance shifts over 160 nm. Using simulations we show how this simple design can create resonance shifts greater than 600 nm. The versatility of this design is further shown by creating asymmetric structures with two different modulation amplitudes, which we experimentally and numerically show to give rise to two resonances. Our results on both the symmetric and asymmetric antennas show the capability to control the localization of the fields outside the antenna, while still maintaining the freedom to change the antenna resonance wavelength. The antenna design we tested combines a large spectral tunability with a small footprint: all the antenna dimensions are factor 7 to 13 smaller than the wavelength, and hold potential as a design element in meta-surfaces for beam shaping.

  16. Investigating Starburst Galaxy Emission Line Equivalent Widths

    NASA Astrophysics Data System (ADS)

    Meskhidze, Helen; Richardson, Chris T.

    2016-01-01

    Modeling star forming galaxies with spectral synthesis codes allows us to study the gas conditions and excitation mechanisms that are necessary to reproduce high ionization emission lines in both local and high-z galaxies. Our study uses the locally optimally-emitting clouds model to develop an atlas of starburst galaxy emission line equivalent widths. Specifically, we address the following question: What physical conditions are necessary to produce strong high ionization emission lines assuming photoionization via starlight? Here we present the results of our photoionization simulations: an atlas spanning 15 orders of magnitude in ionizing flux and 10 orders of magnitude in hydrogen density that tracks over 150 emission lines ranging from the UV to the near IR. Each simulation grid contains ~1.5x104 photoionization models calculated by supplying a spectral energy distribution, grain content, and chemical abundances. Specifically, we will be discussing the effects on the emission line equivalent widths of varying the metallicity of the cloud, Z = 0.2 Z⊙ to Z = 5.0 Z⊙, and varying the star-formation history, using the instantaneous and continuous evolution tracks and the newly released Starburst99 Geneva rotation tracks.

  17. Finite beam-width ray model for geometric spectral broadening.

    PubMed

    Hoskins, P R; Fish, P J; Pye, S D; Anderson, T

    1999-03-01

    The purpose of the study was to compare measured spectral width and maximum frequency with that predicted from ray models of geometric spectral broadening. Zero and finite beam-width models were used. Spectral data were acquired from a string phantom using two commonly-used linear array systems. Beam width and Doppler aperture sizes were measured using a needle hydrophone. The results showed that the experimentally measured data agreed best with the finite beam-width model. The zero beam-width model was in error by up to 50% for calculated spectral width, and up to 10% for maximum frequency. It is concluded that spectral width and maximum frequency are best calculated using the finite beam-width model, and that ultrasound manufacturers could improve the variation in spectral broadening measured at different locations on a single machine by adjusting the aperture size to give a constant subtended angle and beam width.

  18. Comparison of maxillary anterior tooth width and facial dimensions of 3 ethnicities.

    PubMed

    Parciak, Ewa C; Dahiya, Ankur T; AlRumaih, Hamad S; Kattadiyil, Mathew T; Baba, Nadim Z; Goodacre, Charles J

    2017-10-01

    As the cosmetic demands of patients increase, determining the appropriate dimensions of the maxillary anterior teeth has become increasingly relevant. The relationship between facial measurements and tooth size provide guidance for maxillary anterior tooth size selection. However, most publications on this topic have focused on the white population, and more data for tooth sizes and their proportions in other ethnicities are needed. The purpose of this observational study was to investigate the relationship between the mesiodistal dimensions of the 6 maxillary anterior teeth and the bizygomatic width, interpupillary distance, intercanthal distance, interalar width, and intercommissural width of individuals of Asian, African-American, and white ethnicities. Standardized digital images of 360 participants (120 Asian, 120 African-American, and 120 white) were used to measure facial segments. Individual dimensions of the 6 maxillary anterior teeth were measured using stone casts with digital sliding caliper. The combined width of the 6 maxillary anterior teeth on a straight line corresponded to the sum of the anterior tooth width. The means and standard deviations from descriptive measurements were calculated and analyzed for face and maxillary anterior tooth ratios and correlations. Statistical analysis was done using the Kruskal-Wallis procedure to compare facial and tooth parameters among the 3 ethnicities. Appropriate post hoc comparisons that adjusted for multiple testing were conducted when warranted (α=.05). The Spearman rho correlation, a nonparametric correlate of the Pearson correlation, was used to associate the facial and tooth parameters within the strata of sex and ethnicity. No consistent ratios were found among the examined facial dimensions and the mesiodistal dimensions of the 6 maxillary anterior teeth among the 3 ethnicities, except for the central incisor width-to-bizygomatic width ratio. No correlations were found between the facial dimensions

  19. Measurement of width and intensity of particle streaks in turbulent flows

    NASA Astrophysics Data System (ADS)

    Håkansson, Karl M. O.; Kvick, Mathias; Lundell, Fredrik; Prahl Wittberg, Lisa; Söderberg, L. Daniel

    2013-06-01

    Fibre streaks are observed in experiments with fibre suspensions in a turbulent half-channel flow. The preferential concentration methods, most commonly used to quantify preferential particle concentration, are in one dimension found to be concentration dependent. Two different new streak quantification methods are evaluated, one based on Voronoi analysis and the other based on artificial particles with an assigned fixed width. The width of the particle streaks and a measure of the intensity of the streaks, i.e. streakiness, are sought. Both methods are based on the auto-correlation of a signal, generated by summing images in the direction of the streaks. Common for both methods is a severe concentration dependency, verified in experiments keeping the flow conditions constant while the (very dilute) concentration of fibres is altered. The fixed width method is shown to be the most suitable method, being more robust and less computationally expensive. By assuming the concentration dependence to be related to random noise, an expression is derived, which is shown to make the streak width and the streakiness independent of the concentration even at as low concentrations as 0.05 particles per pixel column in an image. The streakiness is obtained by applying an artificial particle width equal to 20 % of the streak width. This artificial particle width is in this study found to be large enough to smoothen the correlation without altering the streakiness nor the streak width. It is concluded that in order to make quantitative comparisons between different experiments or simulations, the evaluation has to be performed with care and be very well documented.

  20. Ozone Depletion from Nearby Supernovae

    NASA Technical Reports Server (NTRS)

    Gehrels, Neil; Laird, Claude M.; Jackman, Charles H.; Cannizzo, John K.; Mattson, Barbara J.; Chen, Wan; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    Estimates made in the 1970's indicated that a supernova occurring within tens of parsecs of Earth could have significant effects on the ozone layer. Since that time improved tools for detailed modeling of atmospheric chemistry have been developed to calculate ozone depletion, and advances have been made also in theoretical modeling of supernovae and of the resultant gamma ray spectra. In addition, one now has better knowledge of the occurrence rate of supernovae in the galaxy, and of the spatial distribution of progenitors to core-collapse supernovae. We report here the results of two-dimensional atmospheric model calculations that take as input the spectral energy distribution of a supernova, adopting various distances from Earth and various latitude impact angles. In separate simulations we calculate the ozone depletion due to both gamma rays and cosmic rays. We find that for the combined ozone depletion from these effects roughly to double the 'biologically active' UV flux received at the surface of the Earth, the supernova must occur at approximately or less than 8 parsecs.

  1. Ozone depletion, paradigms, and politics

    SciTech Connect

    Iman, R.L.

    1993-10-01

    The destruction of the Earth`s protective ozone layer is a prime environmental concern. Industry has responded to this environmental problem by: implementing conservation techniques to reduce the emission of ozone-depleting chemicals (ODCs); using alternative cleaning solvents that have lower ozone depletion potentials (ODPs); developing new, non-ozone-depleting solvents, such as terpenes; and developing low-residue soldering processes. This paper presents an overview of a joint testing program at Sandia and Motorola to evaluate a low-residue (no-clean) soldering process for printed wiring boards (PWBs). Such processes are in widespread use in commercial applications because they eliminate the cleaning operation. The goal of this testing program was to develop a data base that could be used to support changes in the mil-specs. In addition, a joint task force involving industry and the military has been formed to conduct a follow-up evaluation of low-residue processes that encompass the concerns of the tri-services. The goal of the task force is to gain final approval of the low-residue technology for use in military applications.

  2. Retinal vessel width measurement at branchings using an improved electric field theory-based graph approach.

    PubMed

    Xu, Xiayu; Reinhardt, Joseph M; Hu, Qiao; Bakall, Benjamin; Tlucek, Paul S; Bertelsen, Geir; Abràmoff, Michael D

    2012-01-01

    The retinal vessel width relationship at vessel branch points in fundus images is an important biomarker of retinal and systemic disease. We propose a fully automatic method to measure the vessel widths at branch points in fundus images. The method is a graph-based method, in which a graph construction method based on electric field theory is applied which specifically deals with complex branching patterns. The vessel centerline image is used as the initial segmentation of the graph. Branching points are detected on the vessel centerline image using a set of detection kernels. Crossing points are distinguished from branch points and excluded. The electric field based graph method is applied to construct the graph. This method is inspired by the non-intersecting force lines in an electric field. At last, the method is further improved to give a consistent vessel width measurement for the whole vessel tree. The algorithm was validated on 100 artery branchings and 100 vein branchings selected from 50 fundus images by comparing with vessel width measurements from two human experts.

  3. Retinal Vessel Width Measurement at Branchings Using an Improved Electric Field Theory-Based Graph Approach

    PubMed Central

    Xu, Xiayu; Reinhardt, Joseph M.; Hu, Qiao; Bakall, Benjamin; Tlucek, Paul S.; Bertelsen, Geir; Abràmoff, Michael D.

    2012-01-01

    The retinal vessel width relationship at vessel branch points in fundus images is an important biomarker of retinal and systemic disease. We propose a fully automatic method to measure the vessel widths at branch points in fundus images. The method is a graph-based method, in which a graph construction method based on electric field theory is applied which specifically deals with complex branching patterns. The vessel centerline image is used as the initial segmentation of the graph. Branching points are detected on the vessel centerline image using a set of detection kernels. Crossing points are distinguished from branch points and excluded. The electric field based graph method is applied to construct the graph. This method is inspired by the non-intersecting force lines in an electric field. At last, the method is further improved to give a consistent vessel width measurement for the whole vessel tree. The algorithm was validated on 100 artery branchings and 100 vein branchings selected from 50 fundus images by comparing with vessel width measurements from two human experts. PMID:23209588

  4. Device-width dependence of plateau width in quantum Hall states

    NASA Astrophysics Data System (ADS)

    Kawaji, S.; Hirakawa, K.; Nagata, M.

    1993-02-01

    Hall bar type devices having a total length of 2900 μm, a source and drain electrode width of 400 μm and different widths w ranging from 10 to 120 μm in its central 600 μm long part are fabricated from a GaAs/AlGaAs wafer with electron mobility of 21 m 2V -1s -1. The current at which the quantum Hall plateau for i=2 at B=9.7T at T=1.2K disappears is proportional to w. The average critical current density is Jcr=(1.6±0.2) A m -1

  5. Issues in Stratospheric Ozone Depletion.

    NASA Astrophysics Data System (ADS)

    Lloyd, Steven Andrew

    Following the announcement of the discovery of the Antarctic ozone hole in 1985 there have arisen a multitude of questions pertaining to the nature and consequences of polar ozone depletion. This thesis addresses several of these specific questions, using both computer models of chemical kinetics and the Earth's radiation field as well as laboratory kinetic experiments. A coupled chemical kinetic-radiative numerical model was developed to assist in the analysis of in situ field measurements of several radical and neutral species in the polar and mid-latitude lower stratosphere. Modeling was used in the analysis of enhanced polar ClO, mid-latitude diurnal variation of ClO, and simultaneous measurements of OH, HO_2, H_2 O and O_3. Most importantly, such modeling was instrumental in establishing the link between the observed ClO and BrO concentrations in the Antarctic polar vortex and the observed rate of ozone depletion. The principal medical concern of stratospheric ozone depletion is that ozone loss will lead to the enhancement of ground-level UV-B radiation. Global ozone climatology (40^circS to 50^ circN latitude) was incorporated into a radiation field model to calculate the biologically accumulated dosage (BAD) of UV-B radiation, integrated over days, months, and years. The slope of the annual BAD as a function of latitude was found to correspond to epidemiological data for non-melanoma skin cancers for 30^circ -50^circN. Various ozone loss scenarios were investigated. It was found that a small ozone loss in the tropics can provide as much additional biologically effective UV-B as a much larger ozone loss at higher latitudes. Also, for ozone depletions of > 5%, the BAD of UV-B increases exponentially with decreasing ozone levels. An important key player in determining whether polar ozone depletion can propagate into the populated mid-latitudes is chlorine nitrate, ClONO_2 . As yet this molecule is only indirectly accounted for in computer models and field

  6. Direct measurement of the W boson width

    SciTech Connect

    Abazov, V.M.; Abbott, B.; Abolins, M.; Acharya, B.S.; Adams, M.; Adams, T.; Aguilo, E.; Ahsan, M.; Alexeev, G.D.; Alkhazov, G.; Alton, A.; /Michigan U. /Northeastern U.

    2009-09-01

    We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W {yields} e{nu} candidates selected in 1 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron collider in p{bar p} collisions at {radical}s = 1.96 TeV. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 {+-} 0.072 GeV, is in agreement with the predictions of the standard model and is the most precise direct measurement result from a single experiment to date.

  7. Direct measurement of the W boson width.

    PubMed

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Aguilo, E; Ahsan, M; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Ancu, L S; Andeen, T; Anzelc, M S; Aoki, M; Arnoud, Y; Arov, M; Arthaud, M; Askew, A; Asman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Barfuss, A-F; Bargassa, P; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bauer, D; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Benitez, J A; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brock, R; Brooijmans, G; Bross, A; Brown, D; Bu, X B; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calfayan, P; Calpas, B; Calvet, S; Cammin, J; Carrasco-Lizarraga, M A; Carrera, E; Carvalho, W; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Cheu, E; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Cutts, D; Cwiok, M; Das, A; Davies, G; De, K; de Jong, S J; De La Cruz-Burelo, E; DeVaughan, K; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duflot, L; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Escalier, M; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferapontov, A V; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Gadfort, T; Galea, C F; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerber, C E; Gershtein, Y; Gillberg, D; Ginther, G; Golovanov, G; Gómez, B; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Haefner, P; Hagopian, S; Haley, J; Hall, I; Hall, R E; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Hebbeker, T; Hedin, D; Hegeman, J G; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hossain, S; Houben, P; Hu, Y; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jakobs, K; Jamin, D; Jesik, R; Johns, K; Johnson, C; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Juste, A; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kaushik, V; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kirby, M H; Kirsch, M; Klima, B; Kohli, J M; Konrath, J-P; Kozelov, A V; Kraus, J; Kuhl, T; Kumar, A; Kupco, A; Kurca, T; Kuzmin, V A; Kvita, J; Lacroix, F; Lam, D; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, W M; Leflat, A; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Mättig, P; Magaña-Villalba, R; Mal, P K; Malik, S; Malyshev, V L; Maravin, Y; Martin, B; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Mendoza, L; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Mondal, N K; Montgomery, H E; Moore, R W; Moulik, T; Muanza, G S; Mulhearn, M; Mundal, O; Mundim, L; Nagy, E; Naimuddin, M; Narain, M; Neal, H A; Negret, J P; Neustroev, P; Nilsen, H; Nogima, H; Novaes, S F; Nunnemann, T; Obrant, G; Ochando, C; Onoprienko, D; Orduna, J; Oshima, N; Osman, N; Osta, J; Otec, R; Otero y Garzón, G J; Owen, M; Padilla, M; Padley, P; Pangilinan, M; Parashar, N; Park, S-J; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Pétroff, P; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pogorelov, Y; Pol, M-E; Polozov, P; Popov, A V; Prewitt, M; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rakitine, A; Rangel, M S; Ranjan, K; Ratoff, P N; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Robinson, S; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Savage, G; Sawyer, L; Scanlon, T; Schaile, D; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shamim, M; Shary, V; Shchukin, A A; Shivpuri, R K; Siccardi, V; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Stolin, V; Stoyanova, D A; Strandberg, J; Strang, M A; Strauss, E; Strauss, M; Ströhmer, R; Strom, D; Stutte, L; Sumowidagdo, S; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Tiller, B; Titov, M; Tokmenin, V V; Torchiani, I; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Unalan, R; Uvarov, L; Uvarov, S; Uzunyan, S; van den Berg, P J; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vint, P; Vokac, P; Wagner, R; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, G; Weber, M; Wenger, A; Wetstein, M; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zeitnitz, C; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L; Zutshi, V; Zverev, E G

    2009-12-04

    We present a direct measurement of the width of the W boson using the shape of the transverse mass distribution of W --> enu candidate events. Data from approximately 1 fb(-1) of integrated luminosity recorded at square root of s = 1.96 TeV by the D0 detector at the Fermilab Tevatron pp collider are analyzed. We use the same methods and data sample that were used for our recently published W boson mass measurement, except for the modeling of the recoil, which is done with a new method based on a recoil library. Our result, 2.028 +/- 0.072 GeV, is in agreement with the predictions of the standard model.

  8. Red cell distribution width and cancer

    PubMed Central

    Danese, Elisa

    2016-01-01

    Red cell distribution width (RDW) is an index which primarily reflects impaired erythropoiesis and abnormal red blood cell survival. In last years the interest in this marker has considerably grown and now a lot of data are available indicating that this simple and inexpensive parameter is a strong and independent risk factor for death in the general population. Moreover, several investigations have been performed to investigate the role of RDW in cardiovascular and thrombotic disorders. Contrarily, there are relatively few reports focusing on RDW in the area of oncology and to date none review have been performed in this specific field. As such, the aim of this narrative review is to summarize some interesting results obtained in studies performed in patients affected by solid and hematological tumors. Even if larger studies are needed before these preliminary findings can be generalized, it seems plausible to affirm that RDW can be useful by adding prognostic information in patients with oncologic disease. PMID:27867951

  9. In vivo diffusion analysis with quantum dots and dextrans predicts the width of brain extracellular space

    NASA Astrophysics Data System (ADS)

    Thorne, Robert G.; Nicholson, Charles

    2006-04-01

    Diffusion within the extracellular space (ECS) of the brain is necessary for chemical signaling and for neurons and glia to access nutrients and therapeutics; however, the width of the ECS in living tissue remains unknown. We used integrative optical imaging to show that dextrans and water-soluble quantum dots with Stokes-Einstein diameters as large as 35 nm diffuse within the ECS of adult rat neocortex in vivo. Modeling the ECS as fluid-filled "pores" predicts a normal width of 38-64 nm, at least 2-fold greater than estimates from EM of fixed tissue. ECS width falls below 10 nm after terminal ischemia, a likely explanation for the small ECS visualized in electron micrographs. Our results will improve modeling of neurotransmitter spread after spillover and ectopic release and establish size limits for diffusion of drug delivery vectors such as viruses, liposomes, and nanoparticles in brain ECS. drug delivery | integrative optical imaging | nanoparticles | restricted diffusion | somatosensory cortex

  10. Physiological implications of anthropogenic environmental calcium depletion

    Treesearch

    Catherine H. Borer; Paul G. Schaberg; Donald H. DeHayes; Gary J. Hawley

    2001-01-01

    Recent evidence indicates that numerous anthropogenic factors can deplete calcium (Ca) from forested ecosystems. Although it is difficult to quantify the extent of this depletion, some reports indicate that the magnitude of Ca losses may be substantial. The potential for Ca depletion raises important questions about tree health. Only a fraction of foliar Ca is...

  11. Exposure to nature counteracts aggression after depletion.

    PubMed

    Wang, Yan; She, Yihan; Colarelli, Stephen M; Fang, Yuan; Meng, Hui; Chen, Qiuju; Zhang, Xin; Zhu, Hongwei

    2017-08-31

    Acts of self-control are more likely to fail after previous exertion of self-control, known as the ego depletion effect. Research has shown that depleted participants behave more aggressively than non-depleted participants, especially after being provoked. Although exposure to nature (e.g., a walk in the park) has been predicted to replenish resources common to executive functioning and self-control, the extent to which exposure to nature may counteract the depletion effect on aggression has yet to be determined. The present study investigated the effects of exposure to nature on aggression following depletion. Aggression was measured by the intensity of noise blasts participants delivered to an ostensible opponent in a competition reaction-time task. As predicted, an interaction occurred between depletion and environmental manipulations for provoked aggression. Specifically, depleted participants behaved more aggressively in response to provocation than non-depleted participants in the urban condition. However, provoked aggression did not differ between depleted and non-depleted participants in the natural condition. Moreover, within the depletion condition, participants in the natural condition had lower levels of provoked aggression than participants in the urban condition. This study suggests that a brief period of nature exposure may restore self-control and help depleted people regain control over aggressive urges. © 2017 Wiley Periodicals, Inc.

  12. Changing step width alters lower extremity biomechanics during running.

    PubMed

    Brindle, Richard A; Milner, Clare E; Zhang, Songning; Fitzhugh, Eugene C

    2014-01-01

    Step width is a spatiotemporal parameter that may influence lower extremity biomechanics at the hip and knee joint. The purpose of this study was to determine the biomechanical response of the lower extremity joints to step width changes during running. Lower extremity data from 30 healthy runners, half of them male, were collected during running in three step width conditions: preferred, wide, and narrow. Dependent variables and step width were analyzed using a mixed model ANOVA and pairwise t-tests for post hoc comparisons. Step width was successfully altered in the wide and narrow conditions. Generally, frontal plane peak values decreased as step width increased from narrow to preferred to wide. Peak hip adduction and rearfoot eversion angles decreased as step width increased from narrow to wide. Peak knee abduction moment and knee abduction impulse also decreased as step width increased from narrow to wide. Although men and women ran differently, gender only influenced the effect of step width on peak rearfoot inversion moment. In conclusion, step width influences lower extremity biomechanics in healthy runners. When step width increased from narrow to wide, peak values of frontal plane variables decreased. In addition to previously reported changes at the rearfoot, the hip and knee joint biomechanics were also influenced by changes in step width.

  13. The Case of Ozone Depletion

    NASA Technical Reports Server (NTRS)

    Lambright, W. Henry

    2005-01-01

    While the National Aeronautics and Space Administration (NASA) is widely perceived as a space agency, since its inception NASA has had a mission dedicated to the home planet. Initially, this mission involved using space to better observe and predict weather and to enable worldwide communication. Meteorological and communication satellites showed the value of space for earthly endeavors in the 1960s. In 1972, NASA launched Landsat, and the era of earth-resource monitoring began. At the same time, in the late 1960s and early 1970s, the environmental movement swept throughout the United States and most industrialized countries. The first Earth Day event took place in 1970, and the government generally began to pay much more attention to issues of environmental quality. Mitigating pollution became an overriding objective for many agencies. NASA's existing mission to observe planet Earth was augmented in these years and directed more toward environmental quality. In the 1980s, NASA sought to plan and establish a new environmental effort that eventuated in the 1990s with the Earth Observing System (EOS). The Agency was able to make its initial mark via atmospheric monitoring, specifically ozone depletion. An important policy stimulus in many respects, ozone depletion spawned the Montreal Protocol of 1987 (the most significant international environmental treaty then in existence). It also was an issue critical to NASA's history that served as a bridge linking NASA's weather and land-resource satellites to NASA s concern for the global changes affecting the home planet. Significantly, as a global environmental problem, ozone depletion underscored the importance of NASA's ability to observe Earth from space. Moreover, the NASA management team's ability to apply large-scale research efforts and mobilize the talents of other agencies and the private sector illuminated its role as a lead agency capable of crossing organizational boundaries as well as the science-policy divide.

  14. The Large-Scale Plasmaspheric Density Trough Associated With the 24 May 2000 Geomagnetic Storm: IMAGE EUV Observations and Global Core Plasma Modeling

    NASA Technical Reports Server (NTRS)

    Adrian, M. L.; Gallagher, D. L.; Green, J. L.; Sandel, B. R.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    The IMAGE EUV imager observed a plasmaspheric density, trough in association with a geomagnetically active period on 24 May 2000. In EUV, this density, trough appears as an Archimedes spiral extending from Earth's shadow to approximately 1900 MLT. We present an analysis of this density trough using simulated EUV images, Observational EUV images are subjected to edge analysis to establish the plasmapause L-shell and the location of the density trough in terms of L-shell, MLT extent, and radial width. The plasmaspheric density distribution is modeled using both static and dynamic models for the plasmasphere. The background plasmasphere is then numerically simulated using the 4-parameter plasmaspheric density model contained within the Global Core Plasma Model (GCPM) and the Dynamic Global Core Plasma Model (DGCPM). Simulated EUV images of the model plasmasphere are produced once an artificial density, depletion, matching the observed MLT extent and width, has been removed. Once the azimuthal extent and width of the trough have been simulated, the depth of the artificial density depletion is iteratively adjusted to produce simulated EUV images that approximate observation. The results of this analysis and discussion of possible origins for this density trough will be presented.

  15. The Large-Scale Plasmaspheric Density Trough Associated With the 24 May 2000 Geomagnetic Storm: IMAGE EUV Observations and Global Core Plasma Modeling

    NASA Technical Reports Server (NTRS)

    Adrian, M. L.; Gallagher, D. L.; Green, J. L.; Sandel, B. R.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    The IMAGE EUV imager observed a plasmaspheric density, trough in association with a geomagnetically active period on 24 May 2000. In EUV, this density, trough appears as an Archimedes spiral extending from Earth's shadow to approximately 1900 MLT. We present an analysis of this density trough using simulated EUV images, Observational EUV images are subjected to edge analysis to establish the plasmapause L-shell and the location of the density trough in terms of L-shell, MLT extent, and radial width. The plasmaspheric density distribution is modeled using both static and dynamic models for the plasmasphere. The background plasmasphere is then numerically simulated using the 4-parameter plasmaspheric density model contained within the Global Core Plasma Model (GCPM) and the Dynamic Global Core Plasma Model (DGCPM). Simulated EUV images of the model plasmasphere are produced once an artificial density, depletion, matching the observed MLT extent and width, has been removed. Once the azimuthal extent and width of the trough have been simulated, the depth of the artificial density depletion is iteratively adjusted to produce simulated EUV images that approximate observation. The results of this analysis and discussion of possible origins for this density trough will be presented.

  16. Magnetic flux pileup and plasma depletion in Mercury's subsolar magnetosheath

    NASA Astrophysics Data System (ADS)

    Gershman, Daniel J.; Slavin, James A.; Raines, Jim M.; Zurbuchen, Thomas H.; Anderson, Brian J.; Korth, Haje; Baker, Daniel N.; Solomon, Sean C.

    2013-11-01

    from the Fast Imaging Plasma Spectrometer (FIPS) and Magnetometer (MAG) on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft during 40 orbits about Mercury are used to characterize the plasma depletion layer just exterior to the planet's dayside magnetopause. A plasma depletion layer forms at Mercury as a result of piled-up magnetic flux that is draped around the magnetosphere. The low average upstream Alfvénic Mach number (MA ~3-5) in the solar wind at Mercury often results in large-scale plasma depletion in the magnetosheath between the subsolar magnetopause and the bow shock. Flux pileup is observed to occur downstream under both quasi-perpendicular and quasi-parallel shock geometries for all orientations of the interplanetary magnetic field (IMF). Furthermore, little to no plasma depletion is seen during some periods with stable northward IMF. The consistently low value of plasma β, the ratio of plasma pressure to magnetic pressure, at the magnetopause associated with the low average upstream MA is believed to be the cause for the high average reconnection rate at Mercury, reported to be nearly 3 times that observed at Earth. Finally, a characteristic depletion length outward from the subsolar magnetopause of ~300 km is found for Mercury. This value scales among planetary bodies as the average standoff distance of the magnetopause.

  17. Depletion kinetics in the photobleaching trapping reaction inside a flat microchannel

    NASA Astrophysics Data System (ADS)

    Park, Sung Hyun; Peng, Hailin; Kopelman, Raoul; Argyrakis, Panos; Taitelbaum, Haim

    2005-03-01

    The diffusion-limited kinetics of the growth of a depletion zone around a static point trap in a thin, long channel geometry was studied using a laser photobleaching experiment of fluorescein dye inside a flat rectangular capillary. The dynamics of the depletion zone was monitored by the θ distance, defined as the distance from the trap to the point where the reactant concentration has been locally depleted to the specified survival fraction (θ) of its initial bulk value. A dimensional crossover from two dimensions to one dimension, due to the finite width of the reaction zone, was observed. We define a “parallel” and a “perpendicular” θ distance, along the slab long and short dimensions, respectively, and study their time development as a means to study the asymmetrical nature of the slab geometry. For all θ values, the crossover occurs concurrently for both θ distances when the depletion zone touches the boundary for the first time. We derive theoretical expressions for this geometry and compare them with the experimental data. We also obtain important insight from the ratio of the reactant concentration profiles in the parallel and perpendicular directions. Exact enumeration and Monte Carlo simulations support the anomalous depletion scaling results. Nevertheless, the crossover time (τc) is still found to scale with the width (W) of the rectangular reaction zone as τc˜W2 , as expected from the basic Einstein diffusion law.

  18. In-Vivo Measurement Of Subacromial Space Width During Shoulder Elevation

    PubMed Central

    Bey, Michael J.; Brock, Stephanie K.; Beierwaltes, William N.; Zauel, Roger; Kolowich, Patricia A.; Lock, Terrence R.

    2007-01-01

    Background: The shoulder's subacromial space is of significant clinical interest due to its association with rotator cuff disease. Previous studies have estimated the subacromial space width to be 2-17 mm, but no study has measured in-vivo subacromial space width during shoulder motion. The purpose of this study was to measure the in-vivo subacromial space width during shoulder elevation in patients following rotator cuff repair. Methods: Biplane x-ray images were collected during shoulder elevation of 11 patients who had undergone rotator cuff repair. Glenohumeral joint motion was measured from the biplane x-ray images for each subject's repaired and asymptomatic, contralateral shoulders. The joint motion data were combined with subject-specific CT models to measure the subacromial space width during shoulder motion. Findings: Subacromial space width decreased with shoulder elevation, ranging from 2.3-7.4 mm in the repaired shoulder and 1.2-7.1 mm in the contralateral shoulder. Subacromial space width in the repaired shoulder was only 0.5 mm less than the contralateral shoulder when averaged over 10-60 degrees of glenohumeral elevation. Interpretation: The results indicate that the humerus in the repaired shoulder is positioned more cranially on the glenoid than in the contralateral shoulder. It is unclear if these subtle differences in subacromial space width are due to the surgical procedure or post-operative stiffness, or if subacromial impingement contributed to the development of the rotator cuff tear. Future research will ascertain if these results represent a transient response to the surgery or a more fundamental difference in rotator cuff function between repaired and contralateral shoulders. PMID:17560699

  19. Biomedical consequences of ozone depletion

    NASA Astrophysics Data System (ADS)

    Coohill, Thomas P.

    1994-07-01

    It is widely agreed that a portion of the earth's protective stratospheric ozone layer is being depleted. The major effect of this ozone loss will be an increase in the amount of ultraviolet radiation (UV reaching the biosphere. This increase will be completely contained within the UVB (290nm - 320nm). It is imperative that assessments be made of the effects of this additional UVB on living organisms. This requires a detailed knowledge of the UVB photobiology of these life forms. One analytical technique to aid in the approximations is the construction of UV action spectra for such important biological end-points as human skin cancer, cataracts, immune suppression; plant photosynthesis and crop yields; and aquatic organism responses to UVB, especially the phytoplankton. Combining these action spectra with the known solar spectrum (and estimates for various ozone depletion scenarios) can give rise to a series of effectiveness spectra for these parameters. This manuscript gives a first approximation, rough estimate, for the effectiveness spectra for some of these bioresponses, and a series of crude temporary values for how a 10% ozone loss would affect the above end-points. These are not intended to masquerade as final answers, but rather, to serve as beginning attempts for a process which should be continually refined. It is hoped that these estimates will be of some limited use to agencies, such as government and industry, that have to plan now for changes in human activities that might alter future atmospheric chemistry in a beneficial manner.

  20. Global synchronization of parallel processors using clock pulse width modulation

    SciTech Connect

    Chen, Dong; Ellavsky, Matthew R.; Franke, Ross L.; Gara, Alan; Gooding, Thomas M.; Haring, Rudolf A.; Jeanson, Mark J.; Kopcsay, Gerard V.; Liebsch, Thomas A.; Littrell, Daniel; Ohmacht, Martin; Reed, Don D.; Schenck, Brandon E.; Swetz, Richard A.

    2013-04-02

    A circuit generates a global clock signal with a pulse width modification to synchronize processors in a parallel computing system. The circuit may include a hardware module and a clock splitter. The hardware module may generate a clock signal and performs a pulse width modification on the clock signal. The pulse width modification changes a pulse width within a clock period in the clock signal. The clock splitter may distribute the pulse width modified clock signal to a plurality of processors in the parallel computing system.

  1. Influence of Fracture Width on Sealability in High-Strength and Ultra-Low-Permeability Concrete in Seawater

    PubMed Central

    Fukuda, Daisuke; Nara, Yoshitaka; Hayashi, Daisuke; Ogawa, Hideo; Kaneko, Katsuhiko

    2013-01-01

    For cementitious composites and materials, the sealing of fractures can occur in water by the precipitation of calcium compounds. In this study, the sealing behavior in a macro-fractured high-strength and ultra-low-permeability concrete (HSULPC) specimen was investigated in simulated seawater using micro-focus X-ray computed tomography (CT). In particular, the influence of fracture width (0.10 and 0.25 mm) on fracture sealing was investigated. Precipitation occurred mainly at the outermost parts of the fractured surface of the specimen for both fracture widths. While significant sealing was observed for the fracture width of 0.10 mm, sealing was not attained for the fracture width of 0.25 mm within the observation period (49 days). Examination of the sealed regions on the macro-fracture was performed using a three-dimensional image registration technique and applying image subtraction between the CT images of the HSULPC specimen before and after maintaining the specimen in simulated seawater. The temporal change of the sealing deposits for the fracture width of 0.10 mm was much larger than that for the fracture width of 0.25 mm. Therefore, it is concluded that the sealability of the fracture in the HSULPC is affected by the fracture width. PMID:28811396

  2. Thread Graphs, Linear Rank-Width and Their Algorithmic Applications

    NASA Astrophysics Data System (ADS)

    Ganian, Robert

    The introduction of tree-width by Robertson and Seymour [7] was a breakthrough in the design of graph algorithms. A lot of research since then has focused on obtaining a width measure which would be more general and still allowed efficient algorithms for a wide range of NP-hard problems on graphs of bounded width. To this end, Oum and Seymour have proposed rank-width, which allows the solution of many such hard problems on a less restricted graph classes (see e.g. [3,4]). But what about problems which are NP-hard even on graphs of bounded tree-width or even on trees? The parameter used most often for these exceptionally hard problems is path-width, however it is extremely restrictive - for example the graphs of path-width 1 are exactly paths.

  3. Regression methods to investigate the relationship between facial measurements and widths of the maxillary anterior teeth.

    PubMed

    Isa, Zakiah Mohd; Tawfiq, Omar Farouq; Noor, Norliza Mohd; Shamsudheen, Mohd Iqbal; Rijal, Omar Mohd

    2010-03-01

    In rehabilitating edentulous patients, selecting appropriately sized teeth in the absence of preextraction records is problematic. The purpose of this study was to investigate the relationships between some facial dimensions and widths of the maxillary anterior teeth to potentially provide a guide for tooth selection. Sixty full dentate Malaysian adults (18-36 years) representing 2 ethnic groups (Malay and Chinese), with well aligned maxillary anterior teeth and minimal attrition, participated in this study. Standardized digital images of the face, viewed frontally, were recorded. Using image analyzing software, the images were used to determine the interpupillary distance (IPD), inner canthal distance (ICD), and interalar width (IA). Widths of the 6 maxillary anterior teeth were measured directly from casts of the subjects using digital calipers. Regression analyses were conducted to measure the strength of the associations between the variables (alpha=.10). The means (standard deviations) of IPD, IA, and ICD of the subjects were 62.28 (2.47), 39.36 (3.12), and 34.36 (2.15) mm, respectively. The mesiodistal diameters of the maxillary central incisors, lateral incisors, and canines were 8.54 (0.50), 7.09 (0.48), and 7.94 (0.40) mm, respectively. The width of the central incisors was highly correlated to the IPD (r=0.99), while the widths of the lateral incisors and canines were highly correlated to a combination of IPD and IA (r=0.99 and 0.94, respectively). Using regression methods, the widths of the anterior teeth within the population tested may be predicted by a combination of the facial dimensions studied. (c) 2010 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

  4. STELLAR LOCI. I. METALLICITY DEPENDENCE AND INTRINSIC WIDTHS

    SciTech Connect

    Yuan, Haibo; Liu, Xiaowei; Xiang, Maosheng; Huang, Yang; Chen, Bingqiu E-mail: x.liu@pku.edu.cn

    2015-02-01

    Stellar loci are widely used for selection of interesting outliers, reddening determinations, and calibrations. However, until now, the dependence of stellar loci on metallicity has not been fully explored, and their intrinsic widths are unclear. In this paper, by combining the spectroscopic and recalibrated imaging data of the Sloan Digital Sky Survey (SDSS) Stripe 82, we have built a large, clean sample of dwarf stars with accurate colors and well-determined metallicities to investigate the metallicity dependence and intrinsic widths of the SDSS stellar loci. Typically, 1 dex decrease in metallicity causes 0.20 and 0.02 mag decrease in colors u – g and g – r and 0.02 and 0.02 mag increase in colors r – i and i – z, respectively. The variations are larger for metal-rich stars than for metal-poor ones, and larger for F/G/K stars than for A/M ones. Using the sample, we have performed two-dimensional polynomial fitting to the u – g, g – r, r – i, and i – z colors as a function of color g – i and metallicity [Fe/H]. The residuals, at the level of 0.029, 0.008, 0.008, and 0.011 mag for the u – g, g – r, r – i, and i – z colors, respectively, can be fully accounted for by the photometric errors and metallicity uncertainties, suggesting that the intrinsic widths of the loci are at maximum a few millimagnitudes. The residual distributions are asymmetric, revealing that a significant fraction of stars are binaries. In a companion paper, we will present an unbiased estimate of the binary fraction for field stars. Other potential applications of the metallicity-dependent stellar loci are briefly discussed.

  5. Relationship between width of greater trochanters and width of iliac wings in tronchanteric bursitis.

    PubMed

    Viradia, Neal K; Berger, Alex A; Dahners, Laurence E

    2011-09-01

    Trochanteric bursitis is a common disorder that is characterized by inflammation of the bursa, superficial to the greater trochanter of the femur, leading to pain in the lateral hip, and often occurs because of acute trauma or repetitive friction involving the iliotibial band, the greater trochanter, and the bursa. In the study reported here, we hypothesized that the increased incidence of bursitis may be the result of the increased prominence of the trochanter in relation to the wings of the iliac crest. Distances between the outermost edges of trochanters and iliac wings were measured in 202 patients from the University of North Carolina Health Care System-101 without a known diagnosis and 101 with a clinical diagnosis of trochanteric bursitis. To determine significance, t tests for nonpaired data were used. Mean (SD) difference between trochanter and iliac wing widths was 28 (20) mm in the group diagnosed with trochanteric bursitis and 17 (18) mm in the control group. The difference between the groups in this regard was significant (P<.00005). In addition, mean (SD) ratio of trochanter widths to iliac wing widths was 1.09 (.06) in the bursitis group and 1.05 (.06) in the control group. The difference between these groups was significant (P<.0005) in this regard as well. Having trochanters wider in relation to iliac wings was associated with the diagnosis of trochanteric bursitis.

  6. Accurate quantification of width and density of bone structures by computed tomography.

    PubMed

    Hangartner, Thomas N; Short, David F

    2007-10-01

    In computed tomography (CT), the representation of edges between objects of different densities is influenced by the limited spatial resolution of the scanner. This results in the misrepresentation of density of narrow objects, leading to errors of up to 70% and more. Our interest is in the imaging and measurement of narrow bone structures, and the issues are the same for imaging with clinical CT scanners, peripheral quantitative CT scanners or micro CT scanners. Mathematical models, phantoms and tests with patient data led to the following procedures: (i) extract density profiles at one-degree increments from the CT images at right angles to the bone boundary; (ii) consider the outer and inner edge of each profile separately due to different adjacent soft tissues; (iii) measure the width of each profile based on a threshold at fixed percentage of the difference between the soft-tissue value and a first approximated bone value; (iv) correct the underlying material density of bone for each profile based on the measured width with the help of the density-versus-width curve obtained from computer simulations and phantom measurements. This latter curve is specific to a certain scanner and is not dependent on the densities of the tissues within the range seen in patients. This procedure allows the calculation of the material density of bone. Based on phantom measurements, we estimate the density error to be below 2% relative to the density of normal bone and the bone-width error about one tenth of a pixel size.

  7. Accurate quantification of width and density of bone structures by computed tomography

    SciTech Connect

    Hangartner, Thomas N.; Short, David F.

    2007-10-15

    In computed tomography (CT), the representation of edges between objects of different densities is influenced by the limited spatial resolution of the scanner. This results in the misrepresentation of density of narrow objects, leading to errors of up to 70% and more. Our interest is in the imaging and measurement of narrow bone structures, and the issues are the same for imaging with clinical CT scanners, peripheral quantitative CT scanners or micro CT scanners. Mathematical models, phantoms and tests with patient data led to the following procedures: (i) extract density profiles at one-degree increments from the CT images at right angles to the bone boundary; (ii) consider the outer and inner edge of each profile separately due to different adjacent soft tissues; (iii) measure the width of each profile based on a threshold at fixed percentage of the difference between the soft-tissue value and a first approximated bone value; (iv) correct the underlying material density of bone for each profile based on the measured width with the help of the density-versus-width curve obtained from computer simulations and phantom measurements. This latter curve is specific to a certain scanner and is not dependent on the densities of the tissues within the range seen in patients. This procedure allows the calculation of the material density of bone. Based on phantom measurements, we estimate the density error to be below 2% relative to the density of normal bone and the bone-width error about one tenth of a pixel size.

  8. Depleted Argon from Underground Sources

    SciTech Connect

    Back, H. O.; Galbiati, C.; Goretti, A.; Loer, B.; Montanari, D.; Mosteiro, P.; Alexander, T.; Alton, A.; Rogers, H.; Kendziora, C.; Pordes, S.

    2011-04-27

    Argon is a strong scintillator and an ideal target for Dark Matter detection; however {sup 39}Ar contamination in atmospheric argon from cosmic ray interactions limits the size of liquid argon dark matter detectors due to pile-up. Argon from deep underground is depleted in {sup 39}Ar due to the cosmic ray shielding of the earth. In Cortez, Colorado, a CO{sub 2} well has been discovered to contain approximately 600 ppm of argon as a contamination in the CO{sub 2}. We first concentrate the argon locally to 3% in an Ar, N{sub 2}, and He mixture, from the CO{sub 2} through chromatographic gas separation, and then the N{sub 2} and He will be removed by continuous distillation to purify the argon. We have collected 26 kg of argon from the CO{sub 2} facility and a cryogenic distillation column is under construction at Fermilab to further purify the argon.

  9. Depleted uranium disposal options evaluation

    SciTech Connect

    Hertzler, T.J.; Nishimoto, D.D.; Otis, M.D.

    1994-05-01

    The Department of Energy (DOE), Office of Environmental Restoration and Waste Management, has chartered a study to evaluate alternative management strategies for depleted uranium (DU) currently stored throughout the DOE complex. Historically, DU has been maintained as a strategic resource because of uses for DU metal and potential uses for further enrichment or for uranium oxide as breeder reactor blanket fuel. This study has focused on evaluating the disposal options for DU if it were considered a waste. This report is in no way declaring these DU reserves a ``waste,`` but is intended to provide baseline data for comparison with other management options for use of DU. To PICS considered in this report include: Retrievable disposal; permanent disposal; health hazards; radiation toxicity and chemical toxicity.

  10. Development of the Global Width Database for Large Rivers

    NASA Astrophysics Data System (ADS)

    Yamazaki, Dai; O'Loughlin, Fiachra; Trigg, Mark A.; Miller, Zachary F.; Pavelsky, Tamlin M.; Bates, Paul D.

    2014-04-01

    River width is a fundamental parameter of river hydrodynamic simulations, but no global-scale river width database based on observed water bodies has yet been developed. Here we present a new algorithm that automatically calculates river width from satellite-based water masks and flow direction maps. The Global Width Database for Large Rivers (GWD-LR) is developed by applying the algorithm to the SRTM Water Body Database and the HydroSHEDS flow direction map. Both bank-to-bank river width and effective river width excluding islands are calculated for river channels between 60S and 60N. The effective river width of GWD-LR is compared with existing river width databases for the Congo and Mississippi Rivers. The effective river width of the GWD-LR is slightly narrower compared to the existing databases, but the relative difference is within ±20% for most river channels. As the river width of the GWD-LR is calculated along the river channels of the HydroSHEDS flow direction map, it is relatively straightforward to apply the GWD-LR to global and continental-scale river modeling.

  11. Drawdown and stream depletion produced by pumping in the vicinity of a partially penetrating stream

    USGS Publications Warehouse

    Butler, J.J.; Zlotnik, V.A.; Tsou, M.-S.

    2001-01-01

    Commonly used analytical approaches for estimation of pumping-induced drawdown and stream depletion are based on a series of idealistic assumptions about the stream-aquifer system. A new solution has been developed for estimation of drawdown and stream depletion under conditions that are more representative of those in natural systems (finite width stream of shallow penetration adjoining an aquifer of limited lateral extent). This solution shows that the conventional assumption of a fully penetrating stream will lead to a significant overestimation of stream depletion (> 100 %) in many practical applications. The degree of overestimation will depend on the value of the stream leakance parameter and the distance from the pumping well to the stream. Although leakance will increase with stream width, a very wide stream will not necessarily be well represented by a model of a fully penetrating stream. The impact of lateral boundaries depends upon the distance from the pumping well to the stream and the stream leakance parameter. In most cases, aquifer width must be on the order of hundreds of stream widths before the assumption of a laterally infinite aquifer is appropriate for stream-depletion calculations. An important assumption underlying this solution is that stream-channel penetration is negligible relative to aquifer thickness. However, an approximate extension to the case of nonnegligible penetration provides reasonable results for the range of relative penetrations found in most natural systems (up to 85%). Since this solution allows consideration of a much wider range of conditions than existing analytical approaches, it could prove to be a valuable new tool for water management design and water rights adjudication purposes.

  12. Implications of Satellite Swath Width on Global Aerosol Optical Thickness Statistics

    NASA Technical Reports Server (NTRS)

    Colarco, Peter; Kahn, Ralph; Remer, Lorraine; Levy, Robert; Welton, Ellsworth

    2012-01-01

    We assess the impact of swath width on the statistics of aerosol optical thickness (AOT) retrieved by satellite as inferred from observations made by the Moderate Resolution Imaging Spectroradiometer (MODIS). We sub-sample the year 2009 MODIS data from both the Terra and Aqua spacecraft along several candidate swaths of various widths. We find that due to spatial sampling there is an uncertainty of approximately 0.01 in the global, annual mean AOT. The sub-sampled monthly mean gridded AOT are within +/- 0.01 of the full swath AOT about 20% of the time for the narrow swath sub-samples, about 30% of the time for the moderate width sub-samples, and about 45% of the time for the widest swath considered. These results suggest that future aerosol satellite missions with only a narrow swath view may not sample the true AOT distribution sufficiently to reduce significantly the uncertainty in aerosol direct forcing of climate.

  13. In vivo diffusion analysis with quantum dots and dextrans predicts the width of brain extracellular space

    PubMed Central

    Thorne, Robert G.; Nicholson, Charles

    2006-01-01

    Diffusion within the extracellular space (ECS) of the brain is necessary for chemical signaling and for neurons and glia to access nutrients and therapeutics; however, the width of the ECS in living tissue remains unknown. We used integrative optical imaging to show that dextrans and water-soluble quantum dots with Stokes–Einstein diameters as large as 35 nm diffuse within the ECS of adult rat neocortex in vivo. Modeling the ECS as fluid-filled “pores” predicts a normal width of 38–64 nm, at least 2-fold greater than estimates from EM of fixed tissue. ECS width falls below 10 nm after terminal ischemia, a likely explanation for the small ECS visualized in electron micrographs. Our results will improve modeling of neurotransmitter spread after spillover and ectopic release and establish size limits for diffusion of drug delivery vectors such as viruses, liposomes, and nanoparticles in brain ECS. PMID:16567637

  14. High-voltage-compatible, fully depleted CCDs

    SciTech Connect

    Holland, Stephen E.; Bebek, Chris J.; Dawson, Kyle S.; Emes, JohnE.; Fabricius, Max H.; Fairfield, Jessaym A.; Groom, Don E.; Karcher, A.; Kolbe, William F.; Palaio, Nick P.; Roe, Natalie A.; Wang, Guobin

    2006-05-15

    We describe charge-coupled device (CCD) developmentactivities at the Lawrence Berkeley National Laboratory (LBNL).Back-illuminated CCDs fabricated on 200-300 mu m thick, fully depleted,high-resistivity silicon substrates are produced in partnership with acommercial CCD foundry.The CCDs are fully depleted by the application ofa substrate bias voltage. Spatial resolution considerations requireoperation of thick, fully depleted CCDs at high substrate bias voltages.We have developed CCDs that are compatible with substrate bias voltagesof at least 200V. This improves spatial resolution for a given thickness,and allows for full depletion of thicker CCDs than previously considered.We have demonstrated full depletion of 650-675 mu m thick CCDs, withpotential applications in direct x-ray detection. In this work we discussthe issues related to high-voltage operation of fully depleted CCDs, aswell as experimental results on high-voltage-compatible CCDs.

  15. Measured depletion of ions at the biomembrane interface.

    PubMed

    Petrache, Horia I; Kimchi, Itamar; Harries, Daniel; Parsegian, V Adrian

    2005-08-24

    Expected from theory and simulations, depletion of ions at fuzzy biomembrane interfaces has long eluded experiments. Here, we show how salt exclusion can be accurately measured by surprisingly simple yet accurate benchtop measurements. Multilamellar aggregates of common phospholipids sink in low salt but float in salt solutions that are much less dense than the lipid itself. By manipulating bath and lipid densities, using heavy water and varied lipid chain length, we obtain accurate exclusion curves over a wide range of KCl and KBr concentrations. While maintaining a constant width at low salt, the exclusion layer decreases in high salt, following the Debye screening length. Consistent with interfacial accumulation of polarizable ions, bromide salts are less excluded than chloride, with an attraction of approximately 2kBT per Br- ion. So far neglected in theoretical descriptions, the competition between salt exclusion and binding is critical to understanding membrane interactions and specific ionic effects.

  16. Low frequency nonlinear waves in electron depleted magnetized nonthermal plasmas

    NASA Astrophysics Data System (ADS)

    Mobarak Hossen, Md.; Sahadat Alam, Md.; Sultana, Sharmin; Mamun, A. A.

    2016-11-01

    A theoretical study on the ultra-low frequency small but finite amplitude solitary waves has been carried out in an electron depleted magnetized nonthermal dusty plasma consisting of both polarity (positively charged as well as negatively charged) inertial massive dust particles and nonextensive q distributed ions. The reductive perturbation technique is employed to derive the ZakharovKuznetsov (ZK) equation. The basic features of low frequency solitary wave are analyzed via the solution of ZK equation. It is observed that the intrinsic properties (e.g., polarity, amplitude, width, etc.) of dust-acoustic (DA) solitary waves (SWs) are significantly influenced by the effects external magnetic field, obliqueness, nonextensivity of ions, and the ratio of ion number density to the product of electron and negative dust number density. The findings of our results may be useful to explain the low frequency nonlinear wave propagation in some plasma environments like cometary tails, the earth polar mesosphere, Jupiter's magnetosphere, etc.

  17. Ab initio calculations of nuclear widths via an integral relation

    NASA Astrophysics Data System (ADS)

    Nollett, Kenneth M.

    2012-10-01

    I describe the computation of energy widths of nuclear states using an integral over the interaction region of ab initio variational Monte Carlo wave functions, and I present calculated widths for many states. I begin by presenting relations that connect certain short-range integrals to widths. I then present predicted widths for 5⩽A⩽9 nuclei, and I compare them against measured widths. They match the data more closely and with less ambiguity than estimates based on spectroscopic factors. I consider the consequences of my results for identification of observed states in 8B, 9He, and 9Li. I also examine failures of the method and conclude that they generally involve broad states and variational wave functions that are not strongly peaked in the interaction region. After examining bound-state overlap functions computed from a similar integral relation, I conclude that overlap calculations can diagnose cases in which computed widths should not be trusted.

  18. Stability-Guaranteed Width Control for Hot Strip Mill

    NASA Astrophysics Data System (ADS)

    Park, Cheol Jae; Hwang, I. Cheol

    We propose a stability-guaranteed width control (SGWC) for the hot strip finishing mill. It is shown that the proposed SGWC guarantees the stability of the width controller by the universal approximation of the neural network. It is shown through the field test in the hot strip mill of POSCO that the stability of the width controller is guaranteed by the proposed control scheme.

  19. CO depletion in the Gould Belt clouds

    NASA Astrophysics Data System (ADS)

    Christie, H.; Viti, S.; Yates, J.; Hatchell, J.; Fuller, G. A.; Duarte-Cabral, A.; Sadavoy, S.; Buckle, J. V.; Graves, S.; Roberts, J.; Nutter, D.; Davis, C.; White, G. J.; Hogerheijde, M.; Ward-Thompson, D.; Butner, H.; Richer, J.; Di Francesco, J.

    2012-05-01

    We present a statistical comparison of CO depletion in a set of local molecular clouds within the Gould Belt using Sub-millimetre Common User Bolometer Array (SCUBA) and Heterodyne Array Receiver Programme (HARP) data. This is the most wide-ranging study of depletion thus far within the Gould Belt. We estimate CO column densities assuming local thermodynamic equilibrium and, for a selection of sources, using the radiative transfer code RADEX in order to compare the two column density estimation methods. High levels of depletion are seen in the centres of several dust cores in all the clouds. We find that in the gas surrounding protostars, levels of depletion are somewhat lower than for starless cores with the exception of a few highly depleted protostellar cores in Serpens and NGC 2024. There is a tentative correlation between core mass and core depletion, particularly in Taurus and Serpens. Taurus has, on average, the highest levels of depletion. Ophiuchus has low average levels of depletion which could perhaps be related to the anomalous dust grain size distribution observed in this cloud. High levels of depletion are often seen around the edges of regions of optical emission (Orion) or in more evolved or less dynamic regions such as the bowl of L1495 in Taurus and the north-western region of Serpens.

  20. Ego depletion increases risk-taking.

    PubMed

    Fischer, Peter; Kastenmüller, Andreas; Asal, Kathrin

    2012-01-01

    We investigated how the availability of self-control resources affects risk-taking inclinations and behaviors. We proposed that risk-taking often occurs from suboptimal decision processes and heuristic information processing (e.g., when a smoker suppresses or neglects information about the health risks of smoking). Research revealed that depleted self-regulation resources are associated with reduced intellectual performance and reduced abilities to regulate spontaneous and automatic responses (e.g., control aggressive responses in the face of frustration). The present studies transferred these ideas to the area of risk-taking. We propose that risk-taking is increased when individuals find themselves in a state of reduced cognitive self-control resources (ego-depletion). Four studies supported these ideas. In Study 1, ego-depleted participants reported higher levels of sensation seeking than non-depleted participants. In Study 2, ego-depleted participants showed higher levels of risk-tolerance in critical road traffic situations than non-depleted participants. In Study 3, we ruled out two alternative explanations for these results: neither cognitive load nor feelings of anger mediated the effect of ego-depletion on risk-taking. Finally, Study 4 clarified the underlying psychological process: ego-depleted participants feel more cognitively exhausted than non-depleted participants and thus are more willing to take risks. Discussion focuses on the theoretical and practical implications of these findings.

  1. Biologic width and its importance in periodontal and restorative dentistry

    PubMed Central

    Nugala, Babitha; Kumar, BB Santosh; Sahitya, S; Krishna, P Mohana

    2012-01-01

    An adequate understanding of the relationship between periodontal tissues and restorative dentistry is paramount to ensure adequate form, function, esthetics and comfort of the dentition. While most clinicians are aware of this important relationship, uncertainty remains regarding specific concepts such as biologic width, its maintenance and applications of crown lengthening in cases of biologic width violation. Relevant publications regarding biologic width, its violation and management were identified up to August 2011 using manual and electronic database search in Medline, Embase, Directory of Open Access Journals and Google Scholar. This review discusses the concept of biologic width around tooth and its relationship to periodontal health and restorative dentistry. PMID:22368328

  2. Scaling function for surface width for free boundary conditions.

    PubMed

    Jeong, Hyeong-Chai; Kim, Jin Min

    2003-08-01

    We study the restricted curvature model with both periodic and free boundary conditions and show that the scaling function of the surface width depends on the type of boundary conditions. When the free boundary condition is applied, the surface width shows a new dynamic scaling whose asymptotic behavior is different from the usual scaling behavior of the self-affine surfaces. We propose a generalized scaling function for the surface width for free boundary conditions and introduce a normalized surface width to clarify the origin of the superrough phenomena of the model.

  3. Some geometric constraints on ring-width trend

    USGS Publications Warehouse

    Phipps, R.L.

    2005-01-01

    Simulations of tree rings from trees of undisturbed forest sites are used to describe natural, long-term width trends. Ring-width trends of canopy-sized white oak are simulated from regressions of BAI (ring area) data of real trees. Examples are given of a tree from a typical re-growth forest in Illinois and of a more slowly growing tree from an old-growth forest in Kentucky. The long-term width trend was simulated as being toward constant ring width regardless of growth rate of the tree. Conditions by which either increasing or decreasing ring-width trends could be simulated from the same linear BAI trend are examined. I conclude that curvilinear width trends, either increasing or decreasing, represent width adjustments to changes in growth rate (BAI trend) after which the width trend stabilizes to a near-constant value. Interpretation of ring-width trends of trees from undisturbed stands may be useful in assessing stand disturbance history. Copyright ?? 2005 by the Tree-Ring Society.

  4. a Measurement of the Mass, Full Width, and Radiative Width of the Positive B(1237) Meson

    NASA Astrophysics Data System (ADS)

    Collick, Bruce David

    An experiment was performed at Fermi National Accelerator Laboratory to investigate the coherent production of mesons on nuclear targets (lead and copper). The experiment used and 200 GeV/c incident meson beam and a high resolution forward spectrometer consisting of proportional and drift chambers plus a liquid argon photon calorimeter. This thesis reports the results of the process (pi)('+) + A (--->) (pi)('+) (omega) + A. The (pi)('+)(omega) spectrum was found to be dominated by the B('+)(1237) meson. A fit was performed on the line shape of the (pi)('+)(omega) mass spectrum and values of 1.271 (+OR-) 0.011 GeV and 0.232 (+OR-) 0.029 GeV were found for the mass and total width. The helicity zero decay probability of the (omega), (VBAR)F(,0)(VBAR)('2), was measured to be (VBAR)F(,0)(VBAR)('2) = 0.15 (+OR-) 0.035. The t distributions were analyzed allowing the electromagnetic and hadronic production processes to interfer. From these distributions a radiative width of 230 (+OR-) 61 was extracted.

  5. Beneficial Uses of Depleted Uranium

    SciTech Connect

    Brown, C.; Croff, A.G.; Haire, M. J.

    1997-08-01

    Naturally occurring uranium contains 0.71 wt% {sup 235}U. In order for the uranium to be useful in most fission reactors, it must be enriched the concentration of the fissile isotope {sup 235}U must be increased. Depleted uranium (DU) is a co-product of the processing of natural uranium to produce enriched uranium, and DU has a {sup 235}U concentration of less than 0.71 wt%. In the United States, essentially all of the DU inventory is in the chemical form of uranium hexafluoride (UF{sub 6}) and is stored in large cylinders above ground. If this co-product material were to be declared surplus, converted to a stable oxide form, and disposed, the costs are estimated to be several billion dollars. Only small amounts of DU have at this time been beneficially reused. The U.S. Department of Energy (DOE) has begun the Beneficial Uses of DU Project to identify large-scale uses of DU and encourage its reuse for the primary purpose of potentially reducing the cost and expediting the disposition of the DU inventory. This paper discusses the inventory of DU and its rate of increase; DU disposition options; beneficial use options; a preliminary cost analysis; and major technical, institutional, and regulatory issues to be resolved.

  6. Depleted argon from underground sources

    SciTech Connect

    Back, H.O.; Alton, A.; Calaprice, F.; Galbiati, C.; Goretti, A.; Kendziora, C.; Loer, B.; Montanari, D.; Mosteiro, P.; Pordes, S.; /Fermilab

    2011-09-01

    Argon is a powerful scintillator and an excellent medium for detection of ionization. Its high discrimination power against minimum ionization tracks, in favor of selection of nuclear recoils, makes it an attractive medium for direct detection of WIMP dark matter. However, cosmogenic {sup 39}Ar contamination in atmospheric argon limits the size of liquid argon dark matter detectors due to pile-up. The cosmic ray shielding by the earth means that Argon from deep underground is depleted in {sup 39}Ar. In Cortez Colorado a CO{sub 2} well has been discovered to contain approximately 500ppm of argon as a contamination in the CO{sub 2}. In order to produce argon for dark matter detectors we first concentrate the argon locally to 3-5% in an Ar, N{sub 2}, and He mixture, from the CO{sub 2} through chromatographic gas separation. The N{sub 2} and He will be removed by continuous cryogenic distillation in the Cryogenic Distillation Column recently built at Fermilab. In this talk we will discuss the entire extraction and purification process; with emphasis on the recent commissioning and initial performance of the cryogenic distillation column purification.

  7. The influence of sulcus width on simulated electric fields induced by transcranial magnetic stimulation

    NASA Astrophysics Data System (ADS)

    Janssen, A. M.; Rampersad, S. M.; Lucka, F.; Lanfer, B.; Lew, S.; Aydin, Ü.; Wolters, C. H.; Stegeman, D. F.; Oostendorp, T. F.

    2013-07-01

    Volume conduction models can help in acquiring knowledge about the distribution of the electric field induced by transcranial magnetic stimulation. One aspect of a detailed model is an accurate description of the cortical surface geometry. Since its estimation is difficult, it is important to know how accurate the geometry has to be represented. Previous studies only looked at the differences caused by neglecting the complete boundary between cerebrospinal fluid (CSF) and grey matter (Thielscher et al 2011 NeuroImage 54 234-43, Bijsterbosch et al 2012 Med. Biol. Eng. Comput. 50 671-81), or by resizing the whole brain (Wagner et al 2008 Exp. Brain Res. 186 539-50). However, due to the high conductive properties of the CSF, it can be expected that alterations in sulcus width can already have a significant effect on the distribution of the electric field. To answer this question, the sulcus width of a highly realistic head model, based on T1-, T2- and diffusion-weighted magnetic resonance images, was altered systematically. This study shows that alterations in the sulcus width do not cause large differences in the majority of the electric field values. However, considerable overestimation of sulcus width produces an overestimation of the calculated field strength, also at locations distant from the target location.

  8. Equatorial broad plasma depletions associated with the enhanced fountain effect

    NASA Astrophysics Data System (ADS)

    Lee, Woo Kyoung; Kil, Hyosub; Kwak, Young-Sil; Paxton, Larry J.; Zhang, Yongliang; Galkin, Ivan; Batista, Inez S.

    2014-01-01

    plasma depletions (BPDs), plasma depletions whose longitudinal width is over several hundred kilometers, have been detected in the equatorial F region by low-earth-orbit satellites during both magnetically quiet and magnetically disturbed periods. A few hypotheses were suggested to explain the creation of BPDs, but the underlying mechanism of this phenomenon is still under debate. We investigate the origin of BPDs by analyzing the simultaneous in situ and optical observations of the ionosphere on 30 May 2003 (Kp = 8+), 24 April 2012 (Kp = 7-), and 31 October 2012 (Kp = 0+). BPDs on 30 May 2003 were detected by the Republic of China Satellite-1 at an altitude of 600 km, and BPDs on the other days were detected by the Communication/Navigation Outage Forecasting System satellite near an altitude of 400 km. Our results show that the detection of BPDs is closely associated with background ionospheric morphology; BPDs are detected on the days when the equatorial ionization anomaly (EIA) is intense and the crests of the EIA have moved poleward. Measurements of upward plasma motion support the existence of ionospheric uplift at BPD locations. These observations and the detection of BPDs near the magnetic equator lead to the interpretation that the satellite detection of BPDs during those 3 days is likely related to the uplift of the F peak height above the satellite orbits.

  9. Segmentation and determination of joint space width in foot radiographs

    NASA Astrophysics Data System (ADS)

    Schenk, O.; de Muinck Keizer, D. M.; Bernelot Moens, H. J.; Slump, C. H.

    2016-03-01

    Joint damage in rheumatoid arthritis is frequently assessed using radiographs of hands and feet. Evaluation includes measurements of the joint space width (JSW) and detection of erosions. Current visual scoring methods are timeconsuming and subject to inter- and intra-observer variability. Automated measurement methods avoid these limitations and have been fairly successful in hand radiographs. This contribution aims at foot radiographs. Starting from an earlier proposed automated segmentation method we have developed a novel model based image analysis algorithm for JSW measurements. This method uses active appearance and active shape models to identify individual bones. The model compiles ten submodels, each representing a specific bone of the foot (metatarsals 1-5, proximal phalanges 1-5). We have performed segmentation experiments using 24 foot radiographs, randomly selected from a large database from the rheumatology department of a local hospital: 10 for training and 14 for testing. Segmentation was considered successful if the joint locations are correctly determined. Segmentation was successful in only 14%. To improve results a step-by-step analysis will be performed. We performed JSW measurements on 14 randomly selected radiographs. JSW was successfully measured in 75%, mean and standard deviation are 2.30+/-0.36mm. This is a first step towards automated determination of progression of RA and therapy response in feet using radiographs.

  10. Effect of finite detector-element width on the spatial-frequency-dependent detective quantum efficiency

    NASA Astrophysics Data System (ADS)

    Cunningham, Ian A.; Westmore, Michael S.; Fenster, Aaron

    1995-05-01

    Image blur in digital imaging systems results from both the spatial spreading of quanta representing the image in the detector system and from the integration of quanta over the finite detector element width. Linear-systems theory has often been used to describe these blurring mechanisms as a convolution, implying the existence of a corresponding modulation transfer function (MTF) in the spatial-frequency domain. This also implies that the resulting noise- power spectrum (NPS) is modified by the square of the blurring MTF. This deterministic approach correctly describes the effect of each blurring mechanism on the overall system MTF, but does not correctly describe image noise characteristics. This is because the convolution is a deterministic calculation, and neglects the statistical properties of the image quanta. Rabbani et al. developed an expression for the NPS following a stochastic spreading mechanism that correctly accounts for these statistical properties. Use of their results requires a modification in how we should interpret the convolution theorem. We suggest the use of a `stochastic' convolution operator, that uses the Rabbani equation for the NPS rather than the deterministic result. This approach unifies the description of both image blur and image noise into a single linear-systems framework. This method is then used to develop expressions for the signal, NPS, DQE, and pixel SNR for a hypothetical digital detector design that includes the effects of conversion to secondary quanta, stochastic spreading of the secondary quanta, and a finite detector-element width.

  11. A PSF width independent of aberrations in spatially incoherent interferometry (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Xiao, Peng; Fink, Mathias; Boccara, A. Claude

    2017-02-01

    Optical imaging usually suffers from aberrations that are induced by various structures when imaging biological samples. Usually aberrations degrade the imaging system performances by broadening the point spread function (PSF). Unexpectedly we show that in spatially incoherent interferometry like full-filed optical coherence tomography (FFOCT), the system PSF width is almost insensitive to aberrations. Instead of considering the PSF of a classical imaging system such as a microscope, we specifically pay attention to the system PSF of interferometric imaging systems for which an undistorted wavefront from a reference beam interferes with the distorted wavefront of the object beam. By comparing the cases of scanning OCT with spatially coherent illumination, wide-field OCT with spatially coherent illumination and FFOCT with spatially incoherent illumination, we found that in FFOCT with spatially incoherent illumination the system PSF width is almost independent of the aberrations and only its amplitude varies. This is demonstrated by theoretical analysis as well as numerical calculations for different aberrations, and confirmed by experiments with a FFOCT system. It is the first time to the best of our knowledge that such specific merit of incoherent illumination in FFOCT has been demonstrated. Based on this, the signal level is used as metric in our adaptive optics FFOCT system for retinal imaging. Only the main aberrations (defocus and astigmatism) that are dominating in eye are corrected to improve the signal to noise ratio and the high order aberrations are skipped. This would increase the correction speed thus reducing the imaging time.

  12. Observations and Simulations of Formation of Broad Plasma Depletions Through Merging Process

    NASA Technical Reports Server (NTRS)

    Huang, Chao-Song; Retterer, J. M.; Beaujardiere, O. De La; Roddy, P. A.; Hunton, D.E.; Ballenthin, J. O.; Pfaff, Robert F.

    2012-01-01

    Broad plasma depletions in the equatorial ionosphere near dawn are region in which the plasma density is reduced by 1-3 orders of magnitude over thousands of kilometers in longitude. This phenomenon is observed repeatedly by the Communication/Navigation Outage Forecasting System (C/NOFS) satellite during deep solar minimum. The plasma flow inside the depletion region can be strongly upward. The possible causal mechanism for the formation of broad plasma depletions is that the broad depletions result from merging of multiple equatorial plasma bubbles. The purpose of this study is to demonstrate the feasibility of the merging mechanism with new observations and simulations. We present C/NOFS observations for two cases. A series of plasma bubbles is first detected by C/NOFS over a longitudinal range of 3300-3800 km around midnight. Each of the individual bubbles has a typical width of approx 100 km in longitude, and the upward ion drift velocity inside the bubbles is 200-400 m/s. The plasma bubbles rotate with the Earth to the dawn sector and become broad plasma depletions. The observations clearly show the evolution from multiple plasma bubbles to broad depletions. Large upward plasma flow occurs inside the depletion region over 3800 km in longitude and exists for approx 5 h. We also present the numerical simulations of bubble merging with the physics-based low-latitude ionospheric model. It is found that two separate plasma bubbles join together and form a single, wider bubble. The simulations show that the merging process of plasma bubbles can indeed occur in incompressible ionospheric plasma. The simulation results support the merging mechanism for the formation of broad plasma depletions.

  13. Depleted uranium--the growing concern.

    PubMed

    Abu-Qare, Aqel W; Abou-Donia, Mohamed B

    2002-01-01

    Recently, several studies have reported on the health and environmental consequences of the use of depleted uranium. Depleted uranium is a heavy metal that is also radioactive. It is commonly used in missiles as a counterweight because of its very high density (1.6 times more than lead). Immediate health risks associated with exposure to depleted uranium include kidney and respiratory problems, with conditions such as kidney stones, chronic cough and severe dermatitis. Long-term risks include lung and bone cancer. Several published reports implicated exposure to depleted uranium in kidney damage, mutagenicity, cancer, inhibition of bone, neurological deficits, significant decrease in the pregnancy rate in mice and adverse effects on the reproductive and central nervous systems. Acute poisoning with depleted uranium elicited renal failure that could lead to death. The environmental consequences of its residue will be felt for thousands of years. It is inhaled and passed through the skin and eyes, transferred through the placenta into the fetus, distributed into tissues and eliminated in urine. The use of depleted uranium during the Gulf and Kosovo Wars and the crash of a Boeing airplane carrying depleted uranium in Amsterdam in 1992 were implicated in a health concern related to exposure to depleted uranium.

  14. Quantifying channel widths and hydraulic geometry of the Mississippi River Basin with remotely sensed imagery

    NASA Astrophysics Data System (ADS)

    Miller, Z.; Pavelsky, T. M.; Allen, G. H.

    2012-12-01

    The movement of water through river systems plays a crucial role in landscape development, in freshwater resources for human use, and in connecting the atmospheric, terrestrial, and oceanic reservoirs in the hydrologic cycle. Spatial patterns of river form and discharge are often studied using the framework of downstream hydraulic geometry (DHG), which relates downstream changes in channel flow at equivalent frequencies of discharge (Q) to variations in width (w), depth (d), and velocity (v) through three power-law equations: w=aQb, d=cQf, and v=kQm. These relationships are commonly used in hydrologic and landscape evolution models to constrain the distribution of channel characteristics throughout basins. Because studies of DHG have relied on at most several hundred measurements, existing estimates of downstream changes in river form may not capture variability in channel shape across a range of spatial scales. In contrast, the RivWidth software tool allows continuous measurement of river width using remotely sensed imagery. In this study, we develop a continuous map of river width for rivers wider than 100 m in the Mississippi River drainage using water classifications from the National Land Cover Dataset (derived from multi-season 30 m Landsat Thematic Mapper images). This dataset contains 1.2 x 106 individual width measurements and covers 4 x 104 km of river reaches. We use historical discharge and channel data from U.S. Geological Survey gauging stations throughout the basin to validate the width map against in situ channel measurements taken at long-term mean flows. In addition to this dataset's potential contributions to the accuracy of hydrologic models, we use it to construct the DHG framework for the Mississippi Basin on a range of spatial scales. Because continuous downstream variations in river flow are not available through current remote sensing technology, we use drainage area as a proxy for constant-frequency discharge. Drainage area is often

  15. Stream water responses to timber harvest: Riparian buffer width effectiveness

    Treesearch

    Barton D. Clinton

    2011-01-01

    Vegetated riparian buffers are critical for protecting aquatic and terrestrial processes and habitats in southern Appalachian ecosystems. In this case study, we examined the effect of riparian buffer width on stream water quality following upland forest management activities in four headwater catchments. Three riparian buffer widths were delineated prior to cutting; 0m...

  16. A design aid for determining width of filter strips

    Treesearch

    M.G. Dosskey; M.J. Helmers; D.E. Eisenhauer

    2008-01-01

    watershed planners need a tool for determining width of filter strips that is accurate enough for developing cost-effective site designs and easy enough to use for making quick determinations on a large number and variety of sites.This study employed the process-based Vegetative Filter Strip Model to evaluate the relationship between filter strip width and trapping...

  17. Measuring Slit Width and Separation in a Diffraction Experiment

    ERIC Educational Resources Information Center

    Gan, K. K.; Law, A. T.

    2009-01-01

    We present a procedure for measuring slit width and separation in single- and double-slit diffraction experiments. Intensity spectra of diffracted laser light are measured with an optical sensor (PIN diode). Slit widths and separations are extracted by fitting to the measured spectra. We present a simple fitting procedure to account for the…

  18. Measuring Slit Width and Separation in a Diffraction Experiment

    ERIC Educational Resources Information Center

    Gan, K. K.; Law, A. T.

    2009-01-01

    We present a procedure for measuring slit width and separation in single- and double-slit diffraction experiments. Intensity spectra of diffracted laser light are measured with an optical sensor (PIN diode). Slit widths and separations are extracted by fitting to the measured spectra. We present a simple fitting procedure to account for the…

  19. Narrowing carpal arch width to increase cross-sectional area of carpal tunnel--a cadaveric study.

    PubMed

    Li, Zong-Ming; Gabra, Joseph N; Marquardt, Tamara L; Kim, Dong Hee

    2013-04-01

    Carpal tunnel morphology plays an essential role in the etiology and treatment of carpal tunnel syndrome. The purpose of this study was to observe the morphological changes of the carpal tunnel as a result of carpal arch width narrowing. It was hypothesized that carpal arch width narrowing would result in increased height and area of the carpal arch. The carpal arch width of eight cadaveric hands was narrowed by a custom apparatus and cross-sectional ultrasound images were acquired. The carpal arch height and area were quantified as the carpal arch width was narrowed. Correlation and regression analyses were performed for the carpal arch height and area with respect to the carpal arch width. The carpal tunnel became more convex as the carpal arch width was narrowed. The initial carpal arch width, height, and area were 25.7 (SD1.9) mm, 4.1 (SD0.6) mm, and 68.5 (SD14.0) mm(2), respectively. The carpal arch height and area negatively correlated with the carpal arch width, with correlation coefficients of -0.974 (SD0.018) and -0.925 (SD0.034), respectively. Linear regression analyses showed a 1mm narrowing of the carpal arch width resulted in proportional increases of 0.40 (SD0.14) mm in the carpal arch height and 4.0 (SD2.2) mm(2) in the carpal arch area. This study demonstrates that carpal arch width narrowing leads to increased carpal arch height and area, a potential mechanism to reduce the mechanical insult to the median nerve and relieve symptoms associated with carpal tunnel syndrome. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Narrowing carpal arch width to increase cross-sectional area of carpal tunnel – a cadaveric study

    PubMed Central

    Li, Zong-Ming; Gabra, Joseph N.; Marquardt, Tamara L.; Kim, Dong Hee

    2013-01-01

    Background Carpal tunnel morphology plays an essential role in the etiology and treatment of carpal tunnel syndrome. The purpose of this study was to observe the morphological changes of the carpal tunnel as a result of carpal arch width narrowing. It was hypothesized carpal arch width narrowing would result in increased height and area of the carpal arch. Methods The carpal arch width of eight cadaveric hands was narrowed by a custom apparatus and cross-sectional ultrasound images were acquired. The carpal arch height and area were quantified as the carpal arch width was narrowed. Correlation and regression analyses were performed for the carpal arch height and area with respect to the carpal arch width. Findings The carpal tunnel became more convex as the carpal arch width was narrowed. The initial carpal arch width, height, and area were 25.7 (SD 1.9) mm, 4.1 (SD 0.6) mm, and 68.5 (SD 14.0) mm2, respectively. The carpal arch height and area negatively correlated with the carpal arch width, with correlation coefficients of −0.974 (SD 0.018) and −0.925 (SD 0.034), respectively. Linear regression analyses showed a 1 mm narrowing of the carpal arch width resulted in proportional increases of 0.40 (SD 0.14) mm in the carpal arch height and 4.0 (SD 2.2) mm2 in the carpal arch area. Interpretation This study demonstrates that carpal arch width narrowing leads to increased carpal arch height and area, a potential mechanism to reduce the mechanical insult to the median nerve and relieve symptoms associated with carpal tunnel syndrome. PMID:23583095

  1. High homocysteine induces betaine depletion.

    PubMed

    Imbard, Apolline; Benoist, Jean-François; Esse, Ruben; Gupta, Sapna; Lebon, Sophie; de Vriese, An S; de Baulny, Helene Ogier; Kruger, Warren; Schiff, Manuel; Blom, Henk J

    2015-04-28

    Betaine is the substrate of the liver- and kidney-specific betaine-homocysteine (Hcy) methyltransferase (BHMT), an alternate pathway for Hcy remethylation. We hypothesized that BHMT is a major pathway for homocysteine removal in cases of hyperhomocysteinaemia (HHcy). Therefore, we measured betaine in plasma and tissues from patients and animal models of HHcy of genetic and acquired cause. Plasma was collected from patients presenting HHcy without any Hcy interfering treatment. Plasma and tissues were collected from rat models of HHcy induced by diet and from a mouse model of cystathionine β-synthase (CBS) deficiency. S-adenosyl-methionine (AdoMet), S-adenosyl-homocysteine (AdoHcy), methionine, betaine and dimethylglycine (DMG) were quantified by ESI-LC-MS/MS. mRNA expression was quantified using quantitative real-time (QRT)-PCR. For all patients with diverse causes of HHcy, plasma betaine concentrations were below the normal values of our laboratory. In the diet-induced HHcy rat model, betaine was decreased in all tissues analysed (liver, brain, heart). In the mouse CBS deficiency model, betaine was decreased in plasma, liver, heart and brain, but was conserved in kidney. Surprisingly, BHMT expression and activity was decreased in liver. However, in kidney, BHMT and SLC6A12 expression was increased in CBS-deficient mice. Chronic HHcy, irrespective of its cause, induces betaine depletion in plasma and tissues (liver, brain and heart), indicating a global decrease in the body betaine pool. In kidney, betaine concentrations were not affected, possibly due to overexpression of the betaine transporter SLC6A12 where betaine may be conserved because of its crucial role as an osmolyte.

  2. High homocysteine induces betaine depletion

    PubMed Central

    Imbard, Apolline; Benoist, Jean-François; Esse, Ruben; Gupta, Sapna; Lebon, Sophie; de Vriese, An S; de Baulny, Helene Ogier; Kruger, Warren; Schiff, Manuel; Blom, Henk J.

    2015-01-01

    Betaine is the substrate of the liver- and kidney-specific betaine-homocysteine (Hcy) methyltransferase (BHMT), an alternate pathway for Hcy remethylation. We hypothesized that BHMT is a major pathway for homocysteine removal in cases of hyperhomocysteinaemia (HHcy). Therefore, we measured betaine in plasma and tissues from patients and animal models of HHcy of genetic and acquired cause. Plasma was collected from patients presenting HHcy without any Hcy interfering treatment. Plasma and tissues were collected from rat models of HHcy induced by diet and from a mouse model of cystathionine β-synthase (CBS) deficiency. S-adenosyl-methionine (AdoMet), S-adenosyl-homocysteine (AdoHcy), methionine, betaine and dimethylglycine (DMG) were quantified by ESI—LC–MS/MS. mRNA expression was quantified using quantitative real-time (QRT)-PCR. For all patients with diverse causes of HHcy, plasma betaine concentrations were below the normal values of our laboratory. In the diet-induced HHcy rat model, betaine was decreased in all tissues analysed (liver, brain, heart). In the mouse CBS deficiency model, betaine was decreased in plasma, liver, heart and brain, but was conserved in kidney. Surprisingly, BHMT expression and activity was decreased in liver. However, in kidney, BHMT and SLC6A12 expression was increased in CBS-deficient mice. Chronic HHcy, irrespective of its cause, induces betaine depletion in plasma and tissues (liver, brain and heart), indicating a global decrease in the body betaine pool. In kidney, betaine concentrations were not affected, possibly due to overexpression of the betaine transporter SLC6A12 where betaine may be conserved because of its crucial role as an osmolyte. PMID:26182429

  3. Gulf war depleted uranium risks.

    PubMed

    Marshall, Albert C

    2008-01-01

    US and British forces used depleted uranium (DU) in armor-piercing rounds to disable enemy tanks during the Gulf and Balkan Wars. Uranium particulate is generated by DU shell impact and particulate entrained in air may be inhaled or ingested by troops and nearby civilian populations. As uranium is slightly radioactive and chemically toxic, a number of critics have asserted that DU exposure has resulted in a variety of adverse health effects for exposed veterans and nearby civilian populations. The study described in this paper used mathematical modeling to estimate health risks from exposure to DU during the 1991 Gulf War for both US troops and nearby Iraqi civilians. The analysis found that the risks of DU-induced leukemia or birth defects are far too small to result in an observable increase in these health effects among exposed veterans or Iraqi civilians. The analysis indicated that only a few ( approximately 5) US veterans in vehicles accidentally targeted by US tanks received significant exposure levels, resulting in about a 1.4% lifetime risk of DU radiation-induced fatal cancer (compared with about a 24% risk of a fatal cancer from all other causes). These veterans may have also experienced temporary kidney damage. Iraqi children playing for 500 h in DU-destroyed vehicles are predicted to incur a cancer risk of about 0.4%. In vitro and animal tests suggest the possibility of chemically induced health effects from DU internalization, such as immune system impairment. Further study is needed to determine the applicability of these findings for Gulf War exposure to DU. Veterans and civilians who did not occupy DU-contaminated vehicles are unlikely to have internalized quantities of DU significantly in excess of normal internalization of natural uranium from the environment.

  4. Specification for the VERA Depletion Benchmark Suite

    SciTech Connect

    Kim, Kang Seog

    2015-12-17

    CASL-X-2015-1014-000 iii Consortium for Advanced Simulation of LWRs EXECUTIVE SUMMARY The CASL neutronics simulator MPACT is under development for the neutronics and T-H coupled simulation for the pressurized water reactor. MPACT includes the ORIGEN-API and internal depletion module to perform depletion calculations based upon neutron-material reaction and radioactive decay. It is a challenge to validate the depletion capability because of the insufficient measured data. One of the detoured methods to validate it is to perform a code-to-code comparison for benchmark problems. In this study a depletion benchmark suite has been developed and a detailed guideline has been provided to obtain meaningful computational outcomes which can be used in the validation of the MPACT depletion capability.

  5. Action orientation overcomes the ego depletion effect.

    PubMed

    Dang, Junhua; Xiao, Shanshan; Shi, Yucai; Mao, Lihua

    2015-04-01

    It has been consistently demonstrated that initial exertion of self-control had negative influence on people's performance on subsequent self-control tasks. This phenomenon is referred to as the ego depletion effect. Based on action control theory, the current research investigated whether the ego depletion effect could be moderated by individuals' action versus state orientation. Our results showed that only state-oriented individuals exhibited ego depletion. For individuals with action orientation, however, their performance was not influenced by initial exertion of self-control. The beneficial effect of action orientation against ego depletion in our experiment results from its facilitation for adapting to the depleting task. © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  6. Cofilin mediates ATP depletion-induced endothelial cell actin alterations.

    PubMed

    Suurna, Maria V; Ashworth, Sharon L; Hosford, Melanie; Sandoval, Ruben M; Wean, Sarah E; Shah, Bijal M; Bamburg, James R; Molitoris, Bruce A

    2006-06-01

    Ischemia and sepsis lead to endothelial cell damage, resulting in compromised microvascular flow in many organs. Much remains to be determined regarding the intracellular structural events that lead to endothelial cell dysfunction. To investigate potential actin cytoskeletal-related mechanisms, ATP depletion was induced in mouse pancreatic microvascular endothelial cells (MS1). Fluorescent imaging and biochemical studies demonstrated a rapid and progressive increase in F-actin along with a decrease in G-actin at 60 min. Confocal microscopic analysis showed ATP depletion resulted in destruction of actin stress fibers and accumulation of F-actin aggregates. We hypothesized these actin alterations were secondary to dephosphorylation/activation of actin-depolymerizing factor (ADF)/cofilin proteins. Cofilin, the predominant isoform expressed in MS1 cells, was rapidly dephosphorylated/activated during ATP depletion. To directly investigate the role of cofilin activation on the actin cytoskeleton during ischemia, MS1 cells were infected with adenoviruses containing the cDNAs for wild-type Xenopus laevis ADF/cofilin green fluorescent protein [XAC(wt)-GFP], GFP, and the constitutively active and inactive isoforms XAC(S3A)-GFP and XAC(S3E)-GFP. The rate and extent of cortical actin destruction and actin aggregate formation were increased in ATP-depleted XAC(wt)-GFP- and XAC(S3A)-GFP-expressing cells, whereas increased actin stress fibers were observed in XAC(S3E)-GFP-expressing cells. To investigate the upstream signaling pathway of ADF/cofilin, LIM kinase 1-GFP (LIMK1-GFP) was expressed in MS1 cells. Cells expressing LIMK1-GFP protein had higher levels of phosphorylated ADF/cofilin, increased stress fibers, and delayed F-actin cytoskeleton destruction during ATP depletion. These results strongly support the importance of cofilin regulation in ischemia-induced endothelial cell actin cytoskeleton alterations leading to cell damage and microvascular dysfunction.

  7. Effect of step width manipulation on tibial stress during running.

    PubMed

    Meardon, Stacey A; Derrick, Timothy R

    2014-08-22

    Narrow step width has been linked to variables associated with tibial stress fracture. The purpose of this study was to evaluate the effect of step width on bone stresses using a standardized model of the tibia. 15 runners ran at their preferred 5k running velocity in three running conditions, preferred step width (PSW) and PSW±5% of leg length. 10 successful trials of force and 3-D motion data were collected. A combination of inverse dynamics, musculoskeletal modeling and beam theory was used to estimate stresses applied to the tibia using subject-specific anthropometrics and motion data. The tibia was modeled as a hollow ellipse. Multivariate analysis revealed that tibial stresses at the distal 1/3 of the tibia differed with step width manipulation (p=0.002). Compression on the posterior and medial aspect of the tibia was inversely related to step width such that as step width increased, compression on the surface of tibia decreased (linear trend p=0.036 and 0.003). Similarly, tension on the anterior surface of the tibia decreased as step width increased (linear trend p=0.029). Widening step width linearly reduced shear stress at all 4 sites (p<0.001 for all). The data from this study suggests that stresses experienced by the tibia during running were influenced by step width when using a standardized model of the tibia. Wider step widths were generally associated with reduced loading of the tibia and may benefit runners at risk of or experiencing stress injury at the tibia, especially if they present with a crossover running style.

  8. Turner syndrome isochromosome karyotype correlates with decreased dental crown width.

    PubMed

    Rizell, S; Barrenäs, M-L; Andlin-Sobocki, A; Stecksén-Blicks, C; Kjellberg, H

    2012-04-01

    The aim of this project was to study possible influences of Turner syndrome (TS) karyotype and the number of X chromosomes with intact short arm (p-arm) on dental crown width. Primary and permanent mesio-distal crown width was measured on plaster casts from 112 TS females. The influence on crown width of four karyotypes: 1. monosomy (45,X), 2. mosaic (45,X/46,XX), 3. isochromosome, and 4. other, and the number of intact X chromosomal p-arms were investigated. In comparisons between karyotypes, statistically significant differences were found for isochromosome karyotype maxillary second premolars, canines, laterals, mandibular first premolars, and canines, indicating that this karyotype was the most divergent as shown by the most reduced crown width. When each karyotype group were compared versus controls, all teeth in the isochromosome group were significantly smaller than controls (P < 0.01-0.001). The 45,X/46,XX karyotype expressed fewer and smaller differences from controls, while 45,X individuals seemed to display an intermediate tooth width compared with 45,X/46,XX and isochromosomes. No significant difference in crown width was found comparing the groups with one or two intact X chromosomal p-arms. Both primary and permanent teeth proved to have a significantly smaller crown width in the entire group of TS females compared to healthy females. We conclude that the isochromosome group deviates most from other karyotypes and controls, exhibiting the smallest dental crown width, while individuals with 45,X/46,XX mosaicism seemed to have a less affected crown width. An influence of the number of intact p-arms on crown width could not be demonstrated in this study.

  9. Increase in vastus lateralis aponeurosis width induced by resistance training: implications for a hypertrophic model of pennate muscle.

    PubMed

    Wakahara, Taku; Ema, Ryoichi; Miyamoto, Naokazu; Kawakami, Yasuo

    2015-02-01

    This study aimed to ascertain whether training-induced muscle hypertrophy is accompanied by an increase in the aponeurosis width, and to infer its impact on the training-induced increase in the pennation angle. Eleven young men completed a resistance training program of unilateral knee extensions for 12 weeks. Before and after training, anatomical cross-sectional area (ACSA) of the vastus lateralis and its distal aponeurosis width in the transverse plane were measured with magnetic resonance imaging. The pennation angle and fascicle length were also determined with ultrasonography at the midbelly of the muscle. The effect of change in aponeurosis width on the magnitude of training-induced increase in pennation angle was estimated by using a parallelepipedon model. After the training, there were significant increases in ACSA (10.7 ± 7.6 %), pennation angle (10.8 ± 7.3 %) and aponeurosis width (1.9 ± 3.1 %), whereas no significant change was found in the fascicle length. The model simulation shows that the increase in aponeurosis width by 1.9 % reduces the magnitude of increase in pennation angle by only 0.4°. These results indicate that (1) the aponeurosis width of the vastus lateralis increases after 12 weeks of resistance training and (2) the increase in the aponeurosis width accompanying muscle hypertrophy by the amount of ~10 % does not substantially affect the increase in pennation angle.

  10. From H I to Stars: H I Depletion in Starbursts and Star-forming Galaxies in the ALFALFA Hα Survey

    NASA Astrophysics Data System (ADS)

    Jaskot, A. E.; Oey, M. S.; Salzer, J. J.; Van Sistine, A.; Bell, E. F.; Haynes, M. P.

    2015-07-01

    H i in galaxies traces the fuel for future star formation and reveals the effects of feedback on neutral gas. Using a statistically uniform, H i-selected sample of 565 galaxies from the Arecibo Legacy Fast ALFA (ALFALFA) Hα survey, we explore H i properties as a function of star formation activity. ALFALFA Hα provides R-band and Hα imaging for a volume-limited subset of the 21 cm ALFALFA survey. We identify eight starbursts based on Hα equivalent width and six with enhanced star formation relative to the main sequence. Both starbursts and non-starbursts have similar H i-to-stellar mass ratios ({M}{{H} {{I}}}/{M}*), which suggests that feedback is not depleting the starbursts’ H i. Consequently, the starbursts do have shorter H i depletion times ({t}{dep}), implying more efficient H i-to-H2 conversion. While major mergers likely drive this enhanced efficiency in some starbursts, the lowest-mass starbursts may experience periodic bursts, consistent with enhanced scatter in {t}{dep} at low {M}*. Two starbursts appear to be pre-coalescence mergers; their elevated {M}{{H} {{I}}}/{M}* suggest that H i-to-H2 conversion is still ongoing at this stage. By comparing with the GASS sample, we find that {t}{dep} anticorrelates with stellar surface density for disks, while spheroids show no such trend. Among early-type galaxies, {t}{dep} does not correlate with bulge-to-disk ratio; instead, the gas distribution may determine the star formation efficiency. Finally, the weak connection between galaxies’ specific star formation rates and {M}{{H} {{I}}}/{M}* contrasts with the well-known correlation between {M}{{H} {{I}}}/{M}* and color. We show that dust extinction can explain the H i-color trend, which may arise from the relationship between {M}*, {M}{{H} {{I}}}, and metallicity.

  11. Monitoring of Varying Joint Gap Width During Laser Beam Welding by a Dual Vision and Spectroscopic Sensing System

    NASA Astrophysics Data System (ADS)

    Nilsen, Morgan; Sikström, Fredrik; Christiansson, Anna-Karin; Ancona, Antonio

    A vision and spectroscopic system for estimation of the joint gap width in autogenous laser beam butt welding is presented. Variations in joint gap width can introduce imperfections in the butt joint seam, which in turn influence fatigue life and structural integrity. The aim of the monitoring approach explored here is to acquire sufficiently robust process data to be used to guide post inspection activities and/or to enable feedback control for a decreased process variability. The dual-sensing approach includes a calibrated CMOS camera and a miniature spectrometer integrated with a laser beam tool. The camera system includes LED illumination and matching optical filters and captures images of the area in front of the melt pool in order to estimate the joint gap width from the information in the image. The intensity of different spectral lines acquired by the spectrometer has been investigated and the correlation between the intensity of representative lines and the joint gap width has been studied. Welding experiments have been conducted using a 6 kW fiber laser. Results from both systems are promising, the camera system is able to give good estimations of the joint gap width, and good correlations between the signal from the spectrometer and the joint gap width have been found. However, developments of the camera setup and vision algorithm can further improve the joint gap estimations and more experimental work is needed in order to evaluate the robustness of the systems.

  12. Step width alters iliotibial band strain during running.

    PubMed

    Meardon, Stacey A; Campbell, Samuel; Derrick, Timothy R

    2012-11-01

    This study assessed the effect of step width during running on factors related to iliotibial band (ITB) syndrome. Three-dimensional (3D) kinematics and kinetics were recorded from 15 healthy recreational runners during overground running under various step width conditions (preferred and at least +/- 5% of their leg length). Strain and strain rate were estimated from a musculoskeletal model of the lower extremity. Greater ITB strain and strain rate were found in the narrower step width condition (p < 0.001, p = 0.040). ITB strain was significantly (p < 0.001) greater in the narrow condition than the preferred and wide conditions and it was greater in the preferred condition than the wide condition. ITB strain rate was significantly greater in the narrow condition than the wide condition (p = 0.020). Polynomial contrasts revealed a linear increase in both ITB strain and strain rate with decreasing step width. We conclude that relatively small decreases in step width can substantially increase ITB strain as well as strain rates. Increasing step width during running, especially in persons whose running style is characterized by a narrow step width, may be beneficial in the treatment and prevention of running-related ITB syndrome.

  13. What sets the minimum tokamak scrape-off layer width?

    NASA Astrophysics Data System (ADS)

    Joseph, Ilon

    2016-10-01

    The heat flux width of the tokamak scrape-off layer is on the order of the poloidal ion gyroradius, but the ``heuristic drift'' physics model is still not completely understood. In the absence of anomalous transport, neoclassical transport sets the minimum width. For plateau collisionality, the ion temperature width is set by qρi , while the electron temperature width scales as the geometric mean q(ρeρi) 1 / 2 and is close to qρi in magnitude. The width is enhanced because electrons are confined by the sheath potential and have a much longer time to radially diffuse before escaping to the wall. In the Pfirsch-Schluter regime, collisional diffusion increases the width by the factor (qR / λ) 1 / 2 where qR is the connection length and λ is the mean free path. This qualitatively agrees with the observed transition in the scaling law for detached plasmas. The radial width of the SOL electric field is determined by Spitzer parallel and ``neoclassical'' radial electric conductivity and has a similar scaling to that for thermal transport. Prepared under US DOE contract DE-AC52-07NA27344.

  14. Downflow Width Behavior of Martian and Terrestrial Lava Flows

    NASA Astrophysics Data System (ADS)

    Peitersen, M. N.; Crown, D. A.

    1996-03-01

    Lava flow morphology is typically the primary type of data available for constraining planetary volcanic processes. Flow emplacement (and hence morphology) is controlled by topography, rheology, and thermal history, but the exact relationship between these factors and the resulting flow shape is not well understood. Accurate interpretation of flow dynamics is dependent upon well-constrained flow geometry. Previous modeling studies have commonly assumed relatively constant flow widths and/or cross-sectional areas, use a single value for width based upon a limited number of measurements, or do not consider width at all. Recent analysis of individual flow lobes in the Puu Oo flow field on the east rift zone of Kilauea Volcano show that flow widths vary by up to an order of magnitude. Significant width variations in Martian flows on Tyrhenna Patera, Alba Patera, and Elysium Mons are also observed. Complex flow-forms may be the result of spatially-interacting, temporally-discrete episodes in addition to contemporaneously emplaced flows. Variations in width with downflow distance from the vent may provide critical clues to flow emplacement processes and volcanic stratigraphy; furthermore, flow width is one of the few characteristics that can easily be measured from planetary mission data. The relative widths and lengths of lava flows are presumably a function of the relationship between the lateral spreading rate and flow front advance. Width/length "aspect ratios" are used to quantify this; however, they are highly dependent upon flow history interpretations. Although topography is thought to be a primary control, recent studies have demonstrated a marked insensitivity of flow morphology to topographic variations at 20 to 40 foot scales.

  15. Possible ozone depletions following nuclear explosions

    NASA Technical Reports Server (NTRS)

    Whitten, R. C.; Borucki, W. J.; Turco, R. P.

    1975-01-01

    The degree of depletion of the ozone layer ensuing after delivery of strategic nuclear warheads (5000 and 10,000 Mton) due to production of nitrogen oxides is theoretically assessed. Strong depletions are calculated for 16-km and 26-km altitudes, peaking 1-2 months after detonation and lasting for three years, while a significant depletion at 36 km would peak after one year. Assuming the explosions occur between 30 and 70 deg N, these effects should be much more pronounced in this region than over the Northern Hemisphere as a whole. It is concluded that Hampson's concern on this matter (1974) is well-founded.-

  16. Fully Depleted Charge-Coupled Devices

    SciTech Connect

    Holland, Stephen E.

    2006-05-15

    We have developed fully depleted, back-illuminated CCDs thatbuild upon earlier research and development efforts directed towardstechnology development of silicon-strip detectors used inhigh-energy-physics experiments. The CCDs are fabricated on the same typeof high-resistivity, float-zone-refined silicon that is used for stripdetectors. The use of high-resistivity substrates allows for thickdepletion regions, on the order of 200-300 um, with corresponding highdetection efficiency for near-infrared andsoft x-ray photons. We comparethe fully depleted CCD to thep-i-n diode upon which it is based, anddescribe the use of fully depleted CCDs in astronomical and x-ray imagingapplications.

  17. Possible ozone depletions following nuclear explosions

    NASA Technical Reports Server (NTRS)

    Whitten, R. C.; Borucki, W. J.; Turco, R. P.

    1975-01-01

    The degree of depletion of the ozone layer ensuing after delivery of strategic nuclear warheads (5000 and 10,000 Mton) due to production of nitrogen oxides is theoretically assessed. Strong depletions are calculated for 16-km and 26-km altitudes, peaking 1-2 months after detonation and lasting for three years, while a significant depletion at 36 km would peak after one year. Assuming the explosions occur between 30 and 70 deg N, these effects should be much more pronounced in this region than over the Northern Hemisphere as a whole. It is concluded that Hampson's concern on this matter (1974) is well-founded.-

  18. Searching constant width mazes captures the AC 0 hierarchy

    NASA Astrophysics Data System (ADS)

    Barrington, David A. Mix; Lu, Chi-Jen; Miltersen, Peter Bro; Skyum, Sven

    We show that searching a width k maze is complete for Π k, i.e., for the k'th level of the AC 0 hierarchy. Equivalently, st-connectivity for width k grid graphs is complete for Π k. As an application, we show that there is a data structure solving dynamic st-connectivity for con stant width grid graphs with time bound O(log log n) per operation on a random access machine. The dynamic algorithm is derived from the parallel one in an indirect way using algebraic tools.

  19. Bank stability and channel width adjustment, East Fork River, Wyoming.

    USGS Publications Warehouse

    Andrews, E.D.

    1982-01-01

    Frequent surveys of eight cross sections located in self-formed reaches of the East Fork River, Wyoming, during the 1974 snowmelt flood showed a close relation between channel morphology and scour and fill. Those cross sections narrower than the mean reach width filled at discharges less than bankfull and scoured at discharges greater than bankfull. Those cross sections wider than the mean reach width scoured at discharges less than bankfull and filled at discharges greater than bankfull. Bank stability, and to some extent the adjustment of stream channel width, in the East Fork River study reach appears to be controlled by the processes of scour and fill. -from Author

  20. The influence of sulcus width on simulated electric fields induced by transcranial magnetic stimulation

    PubMed Central

    Janssen, A M; Rampersad, S M; Lucka, F; Lanfer, B; Lew, S; Aydin, Ü; Wolters, C H; Stegeman, D F; Oostendorp, T F

    2013-01-01

    Volume conduction models can help in acquiring knowledge about the distribution of the electric field induced by transcranial magnetic stimulation (TMS). One aspect of a detailed model is an accurate description of the cortical surface geometry. Since its estimation is difficult, it is important to know how accurate the geometry has to be represented. Previous studies only looked at the differences caused by neglecting the complete boundary between the CSF and GM (Thielscher et al. 2011; Bijsterbosch et al. 2012), or by resizing the whole brain (Wagner et al. 2008). However, due to the high conductive properties of the CSF, it can be expected that alterations in sulcus width can already have a significant effect on the distribution of the electric field. To answer this question, the sulcus width of a highly realistic head model, based on T1-, T2- and diffusion-weighted magnetic resonance images (MRI), was altered systematically. This study shows that alterations in the sulcus width do not cause large differences in the majority of the electric field values. However, considerable overestimation of sulcus width produces an overestimation of the calculated field strength, also at locations distant from the target location. PMID:23787706

  1. The perception of apparent auditory source width in hearing-impaired adults

    PubMed Central

    Whitmer, William M.; Seeber, Bernhard U.; Akeroyd, Michael A.

    2014-01-01

    In a previous study [W. Whitmer, B. Seeber and M. Akeroyd, J. Acoust. Soc. Am. 132, 369-379 (2012)], it was demonstrated that older hearing-impaired (HI) listeners produced visual sketches of headphone-presented noises that were insensitive to changes in interaural coherence. The current study further explores this insensitivity by comparing (a) binaural temporal fine-stucture (TFS) resolution and (b) sound localization precision to (c) auditory source width judgments. Thirty-five participants aged 26-81 years with normal to moderately impaired hearing (a) discriminated interaurally phase-shifted tones from diotic tones presented over headphones, (b) located 500-ms speech-spectrum filtered click trains presented over loudspeakers between ±30° in quiet, and (c) sketched the perceived width of low-pass, high-pass and speech-spectrum noise stimuli presented over loudspeakers from 0° and simultaneously from ±45° at attenuations of 0-20 dB to generate partially coherent stimuli. The results showed a decreasing sensitivity to width with age and impairment which was related to binaural TFS threshold: the worse one’s threshold – which was correlated with age – the less the perceived width increased with decreasing interaural coherence. These results suggest that senescent changes to the auditory system do not necessarily lead to perceptions of broader, more diffuse sound images based on interaural coherence. PMID:24907818

  2. Predicting the backside width of weld pool during pulsed GTAW process based on a neural network model

    NASA Astrophysics Data System (ADS)

    Zhang, Guangjun; Chen, Shanben; Liu, Xiaodong; Wu, Lin

    2001-10-01

    Modeling of welding process is the base of process control. Because welding process is a multivariable, strong coupling, time-varying and nonlinear system, traditional modeling methods are not suitable. In this paper, the dynamic neural network model for predicting backside width of pulsed GTAW weld pool by welding parameters and topside shape parameters was constructed. Orthogonal method was applied to design the sampling experiments. Experiments were carried on low carbon steel with 2mm thickness during pulsed gas tungsten arc butt-welding with gap. Based on self-developed vision sensor, double-side images of weld pool were captured simultaneously in a frame. By image processing the topside dimension and shape of weld pool, such as length, maximum width, gap width and the half-length ratio, and the backside dimension such as area, length and maximum width were calculated. Artificial neural network was applied to establish the model for predicting backside width of weld pool. The inputs of the model were the topside dimension, shape of weld pool and welding parameters such as pulse current, pulse duty ratio, and welding speed. The output of the model was the backside width of weld pool. The algorithm was the extended delta-bar-delta (EDD), and the learning ratio automatically determined by the algorithm. Threshold function was sigmoid function. The training cycle was selected to be 50000. The final EMS error of backside width was 5.2 percent. The simulation experiments were carried out to test the accuracy of the ANN model. From the results of the test, the output of ANN model can predict the backside width precisely.

  3. Woody debris volume depletion through decay: implications for biomass and carbon accounting

    USGS Publications Warehouse

    Fraver, Shawn; Milo, Amy M.; Bradford, John B.; D'Amato, Anthony W.; Kenefic, Laura; Palik, Brian J.; Woodall, Christopher W.; Brissette, John

    2013-01-01

    Woody debris decay rates have recently received much attention because of the need to quantify temporal changes in forest carbon stocks. Published decay rates, available for many species, are commonly used to characterize deadwood biomass and carbon depletion. However, decay rates are often derived from reductions in wood density through time, which when used to model biomass and carbon depletion are known to underestimate rate loss because they fail to account for volume reduction (changes in log shape) as decay progresses. We present a method for estimating changes in log volume through time and illustrate the method using a chronosequence approach. The method is based on the observation, confirmed herein, that decaying logs have a collapse ratio (cross-sectional height/width) that can serve as a surrogate for the volume remaining. Combining the resulting volume loss with concurrent changes in wood density from the same logs then allowed us to quantify biomass and carbon depletion for three study species. Results show that volume, density, and biomass follow distinct depletion curves during decomposition. Volume showed an initial lag period (log dimensions remained unchanged), even while wood density was being reduced. However, once volume depletion began, biomass loss (the product of density and volume depletion) occurred much more rapidly than density alone. At the temporal limit of our data, the proportion of the biomass remaining was roughly half that of the density remaining. Accounting for log volume depletion, as demonstrated in this study, provides a comprehensive characterization of deadwood decomposition, thereby improving biomass-loss and carbon-accounting models.

  4. A definition of depletion of fish stocks

    USGS Publications Warehouse

    Van Oosten, John

    1949-01-01

    Attention was focused on the need of a common and better understanding of the term depletion as applied to the fisheries in order to eliminate if possible the existing inexactness of thought on the subject. Depletion has been confused at various times with at least ten different ideas associated with it but which, as has has heen pointed out, are not synonymous at all. In defining depletion we must recognize that the term represents a condition and must not he confounded with the cause (overfishing) that leads to this condition or with the symptoms that identify it. Depletion was defined as a reduction, through overfishing, in the level of abundance of the exploitable segment of a stock that prevents the realization of the maximum productive capacity.

  5. [Hepatomioneuropathy secondary to mitochondrial DNA depletion].

    PubMed

    Blanco-Barca, M O; Gómez-Lado, C; Campos-González, Y; Castro-Gago, M

    2007-04-01

    Mitochondrial DNA depletion (mtDNA) is an highly heterogeneous condition characterized by a decreased number of mtDNA copies. The patient is a 22-month-old girl with generalized hypotonia, marked weakness, respiratory failure, arterial hypertension, hyperlactacidemia, hepatosplenomegaly and mild hypertransaminasemia without hepatic failure neither hypoketotic hypoglycemia. Electromyographic findings were consistent with neuromyopathy and muscle biopsy suggested a neurogenic atrophy. Electron microscopy revealed lipid droplets, subsarcolemmal accumulation of mitochondrias and glycogen granules. Respiratory chain enzime activities were normal. Genetic study in muscle showed mtDNA depletion, and the diagnosis of spinal muscular atrophy caused by survival motoneuron gene deletion was excluded. This case might be a novel phenotype of mtDNA depletion which could be named hepatomioneuropatyc form. A normal result of respiratory chain enzimes in muscle doesn't excluded mtDNA depletion.

  6. Polar stratospheric clouds and ozone depletion

    NASA Technical Reports Server (NTRS)

    Toon, Owen B.; Turco, Richard P.

    1991-01-01

    A review is presented of investigations into the correlation between the depletion of ozone and the formation of polar stratospheric clouds (PSCs). Satellite measurements from Nimbus 7 showed that over the years the depletion from austral spring to austral spring has generally worsened. Approximately 70 percent of the ozone above Antarctica, which equals about 3 percent of the earth's ozone, is lost during September and October. Various hypotheses for ozone depletion are discussed including the theory suggesting that chlorine compounds might be responsible for the ozone hole, whereby chlorine enters the atmosphere as a component of chlorofluorocarbons produced by humans. The three types of PSCs, nitric acid trihydrate, slowly cooling water-ice, and rapidly cooling water-ice clouds act as important components of the Antarctic ozone depletion. It is indicated that destruction of the ozone will be more severe each year for the next few decades, leading to a doubling in area of the Antarctic ozone hole.

  7. Polar stratospheric clouds and ozone depletion

    NASA Technical Reports Server (NTRS)

    Toon, Owen B.; Turco, Richard P.

    1991-01-01

    A review is presented of investigations into the correlation between the depletion of ozone and the formation of polar stratospheric clouds (PSCs). Satellite measurements from Nimbus 7 showed that over the years the depletion from austral spring to austral spring has generally worsened. Approximately 70 percent of the ozone above Antarctica, which equals about 3 percent of the earth's ozone, is lost during September and October. Various hypotheses for ozone depletion are discussed including the theory suggesting that chlorine compounds might be responsible for the ozone hole, whereby chlorine enters the atmosphere as a component of chlorofluorocarbons produced by humans. The three types of PSCs, nitric acid trihydrate, slowly cooling water-ice, and rapidly cooling water-ice clouds act as important components of the Antarctic ozone depletion. It is indicated that destruction of the ozone will be more severe each year for the next few decades, leading to a doubling in area of the Antarctic ozone hole.

  8. Stark Widths Of Ionized Xenon UV Lines Of Low Intensity

    SciTech Connect

    Cirisan, M.; Djurovic, S.; Pelaez, R. J.; Aparicio, J. A.; Mar, S.

    2007-04-23

    Stark width measurements of several low intensity Xe II spectral lines (5d - 4f transitions) in UV region, are presented here for the first time. These measurements were obtained from helium - xenon pulsed arc plasma.

  9. On the computations of decay widths of Fano resonances

    NASA Astrophysics Data System (ADS)

    Miteva, T.; Kazandjian, S.; Sisourat, N.

    2017-01-01

    In this paper we present an ab initio approach to the computation of decay widths of Fano resonances. The method relies on Fano theory, in which a resonance is described as a bound state embedded in and interacting with a continuum of states. In our approach, we use the Configuration Interaction (CI) method to describe the bound-like and continuum-like parts of the resonance wave function. The aim of this Fano-CI method is to provide decay widths of resonances at a low computational cost such that large systems can be treated. Along with the implementation of the method, we present benchmark calculations of decay widths of Auger and ICD processes in Ne atom, and Ne2 and NeAr dimers. Our results are in good agreement with the decay widths from other theoretical and experimental works. This makes the Fano-CI approach a promising method for the treatment of Fano resonances.

  10. Martian Meanders: Wavelength-Width Scaling and Flow Duration

    NASA Astrophysics Data System (ADS)

    Gregoire-Mazzocco, H.; Stepinski, T. F.; McGovern, P. J.; Lanzoni, S.; Frascati, A.; Rinaldo, A.

    2006-03-01

    Martian meanders reveals linear wavelength/width scaling with a coef. k~10, that can be used to estimate discharges. Simulations of channel evolution are used to determine flow duration from sinuosity. Application to Nirgal Vallis yields 200 yrs.

  11. Widths of some classes of convex functions and bodies

    NASA Astrophysics Data System (ADS)

    Konovalov, V. N.; Maiorov, Vitalii E.

    2010-02-01

    We consider classes of uniformly bounded convex functions defined on convex compact bodies in \\mathbb{R}^d and satisfying a Lipschitz condition and establish the exact orders of their Kolmogorov, entropy, and pseudo-dimension widths in the L_1-metric. We also introduce the notions of pseudo-dimension and pseudo-dimension widths for classes of sets and determine the exact orders of the entropy and pseudo-dimension widths of some classes of convex bodies in \\mathbb{R}^drelative to the pseudo-metric defined as the d-dimensional Lebesgue volume of the symmetric difference of two sets. We also find the exact orders of the entropy and pseudo-dimension widths of the corresponding classes of characteristic functions in L_p-spaces, 1\\le p\\le\\infty.

  12. Optical waveguide device with an adiabatically-varying width

    DOEpatents

    Watts; Michael R. , Nielson; Gregory N.

    2011-05-10

    Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

  13. Effects of Riverbed Conductance on Stream Depletion

    NASA Astrophysics Data System (ADS)

    Lackey, G.; Neupauer, R. M.; Pitlick, J.

    2012-12-01

    In the western United States and other regions of the world where growing population and changing climates are threatening water supplies, accurate modeling of potential human impacts on water resources is becoming more important. Stream depletion, the reduction of surface water flow due to the extraction of groundwater from a hydraulically connected aquifer, is one of the more direct ways that development can alter water availability, degrade water quality and endanger aquatic habitats. These factors have made the accurate modeling of stream depletion an important step in the process of installing groundwater wells in regions that are susceptible to this phenomenon. Proper estimation of stream depletion requires appropriate parameterization of aquifer and streambed hydraulic properties. Although many studies have conducted numerical investigations to determine stream depletion at specific sites, they typically do not measure streambed hydraulic conductivity (Kr), but rather assume a representative value. In this work, we establish a hypothetical model aquifer that is 2000 m by 1600 m and has a meandering stream running through its center. The Kr of the model stream is varied from 1.0x10-9 m s-1 to 1.0x10-2 m s-1 in order to determine the sensitivity of the stream depletion calculations to this parameter. It was found that when Kr is in the lower part of this range, slight changes in K¬r lead to significant impacts on the calculated stream depletion values. We vary Kr along the stream channel according to naturally occurring patterns and demonstrate that alterations of the parameter over a few orders of magnitude can affect the estimated stream depletion caused by a well at a specified location. The numerical simulations show that the mean value of Kr and its spatial variability along the channel should be realistic to develop an accurate model of stream depletion.

  14. Depleted uranium: A DOE management guide

    SciTech Connect

    1995-10-01

    The U.S. Department of Energy (DOE) has a management challenge and financial liability in the form of 50,000 cylinders containing 555,000 metric tons of depleted uranium hexafluoride (UF{sub 6}) that are stored at the gaseous diffusion plants. The annual storage and maintenance cost is approximately $10 million. This report summarizes several studies undertaken by the DOE Office of Technology Development (OTD) to evaluate options for long-term depleted uranium management. Based on studies conducted to date, the most likely use of the depleted uranium is for shielding of spent nuclear fuel (SNF) or vitrified high-level waste (HLW) containers. The alternative to finding a use for the depleted uranium is disposal as a radioactive waste. Estimated disposal costs, utilizing existing technologies, range between $3.8 and $11.3 billion, depending on factors such as applicability of the Resource Conservation and Recovery Act (RCRA) and the location of the disposal site. The cost of recycling the depleted uranium in a concrete based shielding in SNF/HLW containers, although substantial, is comparable to or less than the cost of disposal. Consequently, the case can be made that if DOE invests in developing depleted uranium shielded containers instead of disposal, a long-term solution to the UF{sub 6} problem is attained at comparable or lower cost than disposal as a waste. Two concepts for depleted uranium storage casks were considered in these studies. The first is based on standard fabrication concepts previously developed for depleted uranium metal. The second converts the UF{sub 6} to an oxide aggregate that is used in concrete to make dry storage casks.

  15. Meta-analysis of depleted uranium levels in the Balkan region.

    PubMed

    Besic, Larisa; Muhovic, Imer; Asic, Adna; Kurtovic-Kozaric, Amina

    2017-04-07

    In recent years, contradicting data has been published on the connection between the presence of depleted uranium and an increased cancer incidence among military personnel deployed in the Balkans during the 1992-1999 wars. This has led to numerous research articles investigating possible depleted uranium contamination of the afflicted regions of the Balkan Peninsula, namely Bosnia & Herzegovina, Serbia, Kosovo and Montenegro. The aim of this study was to collect data from previously published reports investigating the levels of depleted uranium in the Balkans and to present the data in the form of a meta-analysis. This would provide a clear image of the extent of depleted uranium contamination after the Balkan conflict. In addition, we tested the hypothesis that there is a correlation between the levels of depleted uranium and the assumed depleted uranium-related health effects. Our results suggest that the majority of the examined sites contain natural uranium, while the area of Kosovo appears to be most heavily afflicted by depleted uranium pollution, followed by Bosnia & Herzegovina. Furthermore, the results indicate that it is not possible to make a valid correlation between the health effects and depleted uranium-contaminated areas. We therefore suggest a structured collaborative plan of action where long-term monitoring of the residents of depleted uranium-afflicted areas would be performed. In conclusion, while the possibility of depleted uranium toxicity in post-conflict regions appears to exist, there currently exists no definitive proof of such effects, due to insufficient studies of potentially afflicted populations, in addition to the lack of a common epidemiological approach in the reviewed literature.

  16. Finite coplanar waveguide width effects in pulsed inductive microwave magnetometry

    SciTech Connect

    Schneider, M.L.; Kos, A.B.; Silva, T.J.

    2004-07-12

    The effect of finite coplanar waveguide (CPW) width on the measurement of the resonance frequency in thin ferromagnetic films has been characterized for pulsed inductive microwave magnetometry. A shift in resonant frequency is a linear function of the ratio of sample thickness to CPW width. The proportionality constant is experimentally determined to be 0.74{+-}0.1 times the saturation magnetization of the film. The frequency shift may be modeled as arising from an effective magnetic-anisotropy field.

  17. Experimental Studies of the Effective Width of Buckled Sheets

    NASA Technical Reports Server (NTRS)

    Lahde, R; Wagner, H

    1936-01-01

    The object of the present experiments is a more exact determination of the effective width for the case of pure compression and of the sheet clamped at the angle section. From the experimental data of the effective width the calculation of the buckling load of an angle joined to a thin sheet is then deduced. The test material consisted of spring-hardened brass sheet.

  18. Anatomy of Depleted Interplanetary Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Kocher, M.; Lepri, S. T.; Landi, E.; Zhao, L.; Manchester, W. B., IV

    2017-01-01

    We report a subset of interplanetary coronal mass ejections (ICMEs) containing distinct periods of anomalous heavy-ion charge state composition and peculiar ion thermal properties measured by ACE/SWICS from 1998 to 2011. We label them “depleted ICMEs,” identified by the presence of intervals where C6+/C5+ and O7+/O6+ depart from the direct correlation expected after their freeze-in heights. These anomalous intervals within the depleted ICMEs are referred to as “Depletion Regions.” We find that a depleted ICME would be indistinguishable from all other ICMEs in the absence of the Depletion Region, which has the defining property of significantly low abundances of fully charged species of helium, carbon, oxygen, and nitrogen. Similar anomalies in the slow solar wind were discussed by Zhao et al. We explore two possibilities for the source of the Depletion Region associated with magnetic reconnection in the tail of a CME, using CME simulations of the evolution of two Earth-bound CMEs described by Manchester et al.

  19. A new definition of maternal depletion syndrome.

    PubMed Central

    Winkvist, A; Rasmussen, K M; Habicht, J P

    1992-01-01

    BACKGROUND. Although the term "maternal depletion syndrome" has been commonly used to explain poor maternal and infant health, whether such a syndrome actually exists remains unclear. This uncertainty may be due to the lack of a clear definition of the syndrome and the absence of theoretical frameworks that account for the many factors related to reproductive nutrition. METHODS. We propose a new definition of maternal depletion syndrome within a framework that accounts for potential confounding factors. RESULTS. Our conceptual framework distinguishes between childbearing pattern and inadequate diet as causes of poor maternal health; hence, our definition of maternal depletion syndrome has both biological and practical meaning. The new definition is based on overall change in maternal nutritional status over one reproductive cycle in relation to possible depletion and repletion phases and in relation to initial nutritional status. CONCLUSIONS. The empirical application of this approach should permit the testing of the existence of maternal depletion syndrome in the developing world, and the distinction between populations where family planning will alleviate maternal depletion and those in which an improved diet is also necessary. PMID:1566948

  20. Crack width monitoring of concrete structures based on smart film

    NASA Astrophysics Data System (ADS)

    Zhang, Benniu; Wang, Shuliang; Li, Xingxing; Zhang, Xu; Yang, Guang; Qiu, Minfeng

    2014-04-01

    Due to its direct link to structural security, crack width is thought to be one of the most important parameters reflecting damage conditions of concrete structures. However, the width problem is difficult to solve with the existing structural health monitoring methods. In this paper, crack width monitoring by means of adhering enameled copper wires with different ultimate strains on the surface of structures is proposed, based on smart film crack monitoring put forward by the present authors. The basic idea of the proposed method is related to a proportional relationship between the crack width and ultimate strain of the broken wire. Namely, when a certain width of crack passes through the wire, some low ultimate strain wires will be broken and higher ultimate strain wires may stay non-broken until the crack extends to a larger scale. Detection of the copper wire condition as broken or non-broken may indicate the width of the structural crack. Thereafter, a multi-layered stress transfer model and specimen experiment are performed to quantify the relationship. A practical smart film is then redesigned with this idea and applied to Chongqing Jiangjin Yangtze River Bridge.

  1. Peak width issues with generalised 2D correlation NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Kirwan, Gemma M.; Adams, Michael J.

    2008-12-01

    Two-dimensional spectral correlation analysis is shown to be sensitive to fluctuations in spectral peak width as a function of perturbation variable. This is particularly significant where peak width fluctuations are of similar order of magnitude as the peak width values themselves and where changes in peak width are not random but are, for example, proportional to intensity. In such cases these trends appear in the asynchronous matrix as false peaks that serve to interfere with interpretation of the data. Complex, narrow band spectra such as provided by 1H NMR spectroscopy are demonstrated to be prone to such interference. 2D correlation analysis was applied to a series of NMR spectra corresponding to a commercial wine fermentation, in which the samples collected over a period of several days exhibit dramatic changes in concentration of minor and major components. The interference due to changing peak width effects is eliminated by synthesizing the recorded spectra using a constant peak width value prior to performing 2D correlation analysis.

  2. Determining the average annual ring width on the front side of lumber

    NASA Astrophysics Data System (ADS)

    Hanning, Tobias; Kickingereder, Reiner; Casasent, David

    2003-05-01

    Visual features of lumber can be used to assure its quality in stiffness and strength. Specifically, the average annual ring distance of the planks and the position of the center of the annual rings of the front side supply a close relation to some quality parameters of planks. Unfortunately, it turns out to be difficult to detect the average annual ring width by simple image vision methods due to distortions in the front side image of a plank caused by the cutting process. In this paper we propose two integrating methods which are capable of being used in an industrial application. One is based on quantizations of color images, the other on local Fourier transformations to detect the main wave in an image.

  3. Measurement of annual ring width of log ends in forest machinery

    NASA Astrophysics Data System (ADS)

    Marjanen, Kalle; Ojala, Petteri; Ihalainen, Heimo

    2008-02-01

    The quality of wood is of increasing importance in wood industry. One important quality aspect is the average annual ring width and its standard deviation that is related to the wood strength and stiffness. We present a camera based measurement system for annual ring measurements. The camera system is designed for outdoor use in forest harvesters. Several challenges arise, such as the quality of cutting process, camera positioning and the light variations. In the freshly cut surface of log end the annual rings are somewhat unclear due to small splinters and saw marks. In the harvester the optical axis of camera cannot be set orthogonally to the log end causing non-constant resolution of the image. The amount of natural light in forest varies from total winter darkness to midsummer brightness. In our approach the image is first geometrically transformed to orthogonal geometry. The annual ring width is measured with two-dimensional power spectra. The two-dimensional power spectra combined with the transformation provide a robust method for estimating the mean and the standard deviation of annual ring width. With laser lighting the variability due to natural lighting can be minimized.

  4. A detection algorithm for scale analysis of post-sunset low-latitude plasma depletions as observed by the Swarm constellation mission

    NASA Astrophysics Data System (ADS)

    Kervalishvili, Guram; Stolle, Claudia; Xiong, Chao

    2016-04-01

    ESA's constellation mission Swarm was successfully launched on 22 November 2013. The three satellites achieved their final constellation on 17 April 2014 and since then Swarm-A and Swarm-C orbiting the Earth at about 470 km (flying side-by-side) and Swarm-B at about 520 km altitude. The satellites carry instruments to monitor the F-region electron density with a sampling frequency of 2 Hz. This paper will present a detection algorithm for low-latitude post-sunset plasma bubbles (depletions), which uses local minima and maxima to detect depletions directly from electron density readings from Swarm. Our analyses were performed in the magnetic latitude (MLat) and local time (MLT) coordinate system. The detection procedure also captures the amplitude of depletion, which is called depth in the following. The width of a bubble corresponds to the length the satellite is located inside a depletion. We discuss the global distribution of depth and width of plasma bubbles and its seasonal and local time dependence for all three Swarm satellites from April 2015 through September 2015. As expected, on global average the bubble occurrence rate is highest for combined equinoxes (Mar, Apr, Sep, and Oct) and smallest for June solstice (May, Jun, Jul, and Aug). MLT distribution of the bubble occurrence number shows a sharp increase at about 19 MLT and decreases towards post-midnight hours. Interestingly, there is an inverse relation between depth and width of bubbles as function of MLT. This is true for all seasons and for all Swarm satellites. The bubble depth (width) is decreasing (increasing) from post-sunset to post-midnight for December solstice (Jan, Feb, Nov, and Dec) and combined equinoxes with about the same amplitude values for bubbles depth (width). Therefore we suggest that at post midnight when the depletions are less steep the structures of the depletions is broader than early after sunset. However for June solstice the depletions are less deep and the bubble depth and

  5. Cartilage Space Width in Slipped Capital Femoral Epiphysis: The Relationship to Cartilage Necrosis 1

    PubMed Central

    Ogden, John A.; Simon, Theodore R.; Southwick, Wayne O.

    1977-01-01

    The radiolucent cartilage space of eighty-three patients with unilateral or bilateral slipped capital femoral epiphysis was measured by a standardized technique. In the majority of patients, whether unilateral or bilateral involvement, there was bilateral narrowing of the cartilage space. In the unaffected hip of unilaterally involved patients, there was a progressive narrowing as skeletal maturity was attained. A concomitant anatomical study of cadaver hips, removed at autopsy from adolescent patients, showed a progressive narrowing of the cartilage as the proximal femur matured. Black females showed most narrowing (minimum cartilage space width), had the narrowest final cartilage space widths, and took the longest to attain this final width. While other racial, sexual and therapeutic groups failed to demonstrate statistically significant differences, the general trend was for females, Blacks, and patients treated by osteotomy to have more joint space narrowing. However, rewidening occurred in most of these affected joint spaces, in contrast to the progressive linear decrease observed in unaffected hips and anatomical specimens. On the basis of this study, we feel that cartilage space narrowing may be anticipated in the post-operative period in most patients treated for slipped capital femoral epiphysis. This narrowing appears to improve with time. Narrowing of greater than one-half the original width, in association with pain and limitation of joint function, probably represents “cartilage necrosis,” or pathologic joint space narrowing. Unless the narrowing remains less than one-half to two-thirds of the initial cartilage space for more than twenty-four to thirty-six months, probably no specific surgical treatment should be undertaken, other than observation and protected weight bearing during any painful phase. Plotting the roentgenographic cartilage space width during the three month to thirty-six month phase may be useful in monitoring and predicting the

  6. Precision targeted ruthenium(ii) luminophores; highly effective probes for cell imaging by stimulated emission depletion (STED) microscopy† †Electronic supplementary information (ESI) available: Detailed synthesis and characterisation of metal complexes and peptides. See DOI: 10.1039/c6sc02588a Click here for additional data file.

    PubMed Central

    Byrne, Aisling; Burke, Christopher S.

    2016-01-01

    Fluorescence microscopy has undergone a dramatic evolution over the past two decades with development of super-resolution far-field microscopy methods that break the light diffraction limited resolution of conventional microscopy, offering unprecedented opportunity to interrogate cellular processes at the nanoscale. However, these methods make special demands of the luminescent agents used for contrast and development of probes suited to super-resolution fluorescent methods is still relatively in its infancy. In spite of their many photophysical advantages, metal complex luminophores have not yet been considered as probes in this regard, where to date, only organic fluorophores have been applied. Here, we report the first examples of metal complex luminophores applied as probes for use in stimulated emission depletion (STED) microscopy. Exemplified with endoplasmic reticulum and nuclear targeting complexes we demonstrate that luminescent Ru(ii) polypyridyl complexes can, through signal peptide targeting, be precisely and selectively delivered to key cell organelles without the need for membrane permeabilization, to give high quality STED images of these organelles. Detailed features of the tubular ER structure are revealed and in the case of the nuclear targeting probe we exploit the molecular light switch properties of a dipyrido[3,2-a:2′,3′-c]phenazine containing complex which emits only on DNA/RNA binding to give outstanding STED contrast and resolution of the chromosomes within the nucleus. Comparing performance with a member of the AlexaFluor family commonly recommended for STED, we find that the performance of the ruthenium complexes is superior across both CW and gated STED microscopy methods in terms of image resolution and photostability. The large Stokes shifts of the Ru probes permit excellent matching of the stimulating depletion laser with their emission whilst avoiding anti-Stokes excitation. Their long lifetimes make them particularly amenable to

  7. The relationship between innercanthal dimension and interalar width to the intercanine width of maxillary anterior teeth in central Indian population

    PubMed Central

    Deogade, Suryakant Chhagan; Mantri, Sneha S.; Sumathi, K.; Rajoriya, Shivani

    2015-01-01

    Statement of Problem: Selection of proper sized maxillary anterior teeth is one of the difficult clinical steps in complete denture esthetics. Several studies have been reported to establish methods of estimating the combined width of maxillary anterior teeth. Purpose: The aim of this study was to determine whether a relationship exists between the innercanthal distance (ICD) and interalar width (IAW) with the combined width of maxillary anterior teeth. Material and Methods: The maxillary anterior teeth of 600 adult subjects were examined. ICD was measured between the median angles of the palpebral fissure. IAW was measured between the ala of the nose at their widest point. The mean combined width of the maxillary anterior teeth was determined intraorally at their widest dimension. Pearson's correlation coefficients were calculated to determine the relationship between ICD, IAW and the combined width of maxillary anterior teeth (α =0.05). Results: Although the Pearson correlation coefficients were relatively small, a significant relationship existed between innercanthal dimension and IAW (P < 0001). Conclusion: Within the limitations of this study, the results suggest that ICD and IAW cannot be used as a preliminary method for determining the width of the maxillary anterior teeth for edentulous patients. PMID:26929493

  8. New Approach For Prediction Groundwater Depletion

    NASA Astrophysics Data System (ADS)

    Moustafa, Mahmoud

    2017-01-01

    Current approaches to quantify groundwater depletion involve water balance and satellite gravity. However, the water balance technique includes uncertain estimation of parameters such as evapotranspiration and runoff. The satellite method consumes time and effort. The work reported in this paper proposes using failure theory in a novel way to predict groundwater saturated thickness depletion. An important issue in the failure theory proposed is to determine the failure point (depletion case). The proposed technique uses depth of water as the net result of recharge/discharge processes in the aquifer to calculate remaining saturated thickness resulting from the applied pumping rates in an area to evaluate the groundwater depletion. Two parameters, the Weibull function and Bayes analysis were used to model and analyze collected data from 1962 to 2009. The proposed methodology was tested in a nonrenewable aquifer, with no recharge. Consequently, the continuous decline in water depth has been the main criterion used to estimate the depletion. The value of the proposed approach is to predict the probable effect of the current applied pumping rates on the saturated thickness based on the remaining saturated thickness data. The limitation of the suggested approach is that it assumes the applied management practices are constant during the prediction period. The study predicted that after 300 years there would be an 80% probability of the saturated aquifer which would be expected to be depleted. Lifetime or failure theory can give a simple alternative way to predict the remaining saturated thickness depletion with no time-consuming processes such as the sophisticated software required.

  9. Tree-ring width reveals the preparation of the 1974 Mt. Etna eruption

    NASA Astrophysics Data System (ADS)

    Seiler, Ruedi; Houlié, Nicolas; Cherubini, Paolo

    2017-03-01

    Reduced near-infrared reflectance observed in September 1973 in Skylab images of the western flank of Mt. Etna has been interpreted as an eruption precursor of the January 1974 eruption. Until now, it has been unclear when this signal started, whether it was sustained and which process(es) could have caused it. By analyzing tree-ring width time-series, we show that the reduced near-infrared precursory signal cannot be linked to a reduction in annual tree growth in the area. However, comparing the tree-ring width time-series with both remote sensing observations and volcano-seismic activity enables us to discuss the starting date of the pre-eruptive period of the 1974 eruption.

  10. Tree-ring width reveals the preparation of the 1974 Mt. Etna eruption

    PubMed Central

    Seiler, Ruedi; Houlié, Nicolas; Cherubini, Paolo

    2017-01-01

    Reduced near-infrared reflectance observed in September 1973 in Skylab images of the western flank of Mt. Etna has been interpreted as an eruption precursor of the January 1974 eruption. Until now, it has been unclear when this signal started, whether it was sustained and which process(es) could have caused it. By analyzing tree-ring width time-series, we show that the reduced near-infrared precursory signal cannot be linked to a reduction in annual tree growth in the area. However, comparing the tree-ring width time-series with both remote sensing observations and volcano-seismic activity enables us to discuss the starting date of the pre-eruptive period of the 1974 eruption. PMID:28266610

  11. Evaluation of dental arch width and form changes after orthodontic treatment and retention with a new computerized method.

    PubMed

    Taner, Tülin Ugur; Ciger, Semra; El, Hakan; Germeç, Derya; Es, Alphan

    2004-10-01

    The purpose of this study was to evaluate longitudinal arch width and form changes and to define arch form types with a new computerized method. Maxillary and mandibular models of 21 Class II Division 1 patients were examined before treatment (T(0)), after treatment (T(1)), and an average of 3 years after retention (T(2)). Arch width measurements were made directly on scanned images of maxillary and mandibular models. Arch form changes at T(0)-T(1) and T(1)-T(2) were evaluated by superimposing the computer-generated Bezier arch curves with a computer program. Types of dental arch forms were defined by superimposing them with the pentamorphic arch system, which included 5 different types of arch forms: normal, ovoid, tapered, narrow ovoid, and narrow tapered. Maxillary arch widths were increased during orthodontic treatment. Mandibular posterior arch widths were also increased. The expansion of the mandibular arch forms was less than in the maxillary arch forms. Arch width changes were generally stable, except for reduction in maxillary and mandibular interlateral, inter-first premolar, and mandibular intercanine widths. Pretreatment maxillary arch forms were mostly tapered; mandibular arch forms were tapered and narrow tapered. In maxillary arch forms, 76% of the treatment changes were maintained. Mandibular arch form was maintained in 67% of the sample, both during treatment and after retention. In mandibular arches, 71% of orthodontically induced arch form changes were maintained.

  12. Depth of field affects perceived depth-width ratios in photographs of natural scenes.

    PubMed

    Nefs, Harold T

    2012-01-01

    The aim of the study was to find out how much influence depth of field has on the perceived ratio of depth and width in photographs of natural scenes. Depth of field is roughly defined as the distance range that is perceived as sharp in the photograph. Four different semi-natural scenes consisting of a central and two flanking figurines were used. For each scene, five series of photos were made, in which the distance in depth between the central figurine and the flanking figurines increased. These series of photographs had different amounts of depth of field. In the first experiment participants adjusted the position of the two flanking figurines relative to a central figurine, until the perceived distance in the depth dimension equaled the perceived lateral distance between the two flanking figurines. Viewing condition was either monocular or binocular (non-stereo). In the second experiment, the participants did the same task but this time we varied the viewing distance. We found that the participants' depth/width settings increased with increasing depth of field. As depth of field increased, the perceived depth in the scene was reduced relative to the perceived width. Perceived depth was reduced relative to perceived width under binocular viewing conditions compared to monocular viewing conditions. There was a greater reduction when the viewing distance was increased. As photographs of natural scenes contain many highly redundant or conflicting depth cues, we conclude therefore that local image blur is an important cue to depth. Moreover, local image blur is not only taken into account in the perception of egocentric distances, but also affects the perception of depth within the scene relative to lateral distances within the scene.

  13. Groundwater depletion embedded in international food trade.

    PubMed

    Dalin, Carole; Wada, Yoshihide; Kastner, Thomas; Puma, Michael J

    2017-03-29

    Recent hydrological modelling and Earth observations have located and quantified alarming rates of groundwater depletion worldwide. This depletion is primarily due to water withdrawals for irrigation, but its connection with the main driver of irrigation, global food consumption, has not yet been explored. Here we show that approximately eleven per cent of non-renewable groundwater use for irrigation is embedded in international food trade, of which two-thirds are exported by Pakistan, the USA and India alone. Our quantification of groundwater depletion embedded in the world's food trade is based on a combination of global, crop-specific estimates of non-renewable groundwater abstraction and international food trade data. A vast majority of the world's population lives in countries sourcing nearly all their staple crop imports from partners who deplete groundwater to produce these crops, highlighting risks for global food and water security. Some countries, such as the USA, Mexico, Iran and China, are particularly exposed to these risks because they both produce and import food irrigated from rapidly depleting aquifers. Our results could help to improve the sustainability of global food production and groundwater resource management by identifying priority regions and agricultural products at risk as well as the end consumers of these products.

  14. The New MCNP6 Depletion Capability

    SciTech Connect

    Fensin, Michael Lorne; James, Michael R.; Hendricks, John S.; Goorley, John T.

    2012-06-19

    The first MCNP based inline Monte Carlo depletion capability was officially released from the Radiation Safety Information and Computational Center as MCNPX 2.6.0. Both the MCNP5 and MCNPX codes have historically provided a successful combinatorial geometry based, continuous energy, Monte Carlo radiation transport solution for advanced reactor modeling and simulation. However, due to separate development pathways, useful simulation capabilities were dispersed between both codes and not unified in a single technology. MCNP6, the next evolution in the MCNP suite of codes, now combines the capability of both simulation tools, as well as providing new advanced technology, in a single radiation transport code. We describe here the new capabilities of the MCNP6 depletion code dating from the official RSICC release MCNPX 2.6.0, reported previously, to the now current state of MCNP6. NEA/OECD benchmark results are also reported. The MCNP6 depletion capability enhancements beyond MCNPX 2.6.0 reported here include: (1) new performance enhancing parallel architecture that implements both shared and distributed memory constructs; (2) enhanced memory management that maximizes calculation fidelity; and (3) improved burnup physics for better nuclide prediction. MCNP6 depletion enables complete, relatively easy-to-use depletion calculations in a single Monte Carlo code. The enhancements described here help provide a powerful capability as well as dictate a path forward for future development to improve the usefulness of the technology.

  15. Depletion sensitivity predicts unhealthy snack purchases.

    PubMed

    Salmon, Stefanie J; Adriaanse, Marieke A; Fennis, Bob M; De Vet, Emely; De Ridder, Denise T D

    2016-01-01

    The aim of the present research is to examine the relation between depletion sensitivity - a novel construct referring to the speed or ease by which one's self-control resources are drained - and snack purchase behavior. In addition, interactions between depletion sensitivity and the goal to lose weight on snack purchase behavior were explored. Participants included in the study were instructed to report every snack they bought over the course of one week. The dependent variables were the number of healthy and unhealthy snacks purchased. The results of the present study demonstrate that depletion sensitivity predicts the amount of unhealthy (but not healthy) snacks bought. The more sensitive people are to depletion, the more unhealthy snacks they buy. Moreover, there was some tentative evidence that this relation is more pronounced for people with a weak as opposed to a strong goal to lose weight, suggesting that a strong goal to lose weight may function as a motivational buffer against self-control failures. All in all, these findings provide evidence for the external validity of depletion sensitivity and the relevance of this construct in the domain of eating behavior. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Groundwater depletion embedded in international food trade

    NASA Astrophysics Data System (ADS)

    Dalin, Carole; Wada, Yoshihide; Kastner, Thomas; Puma, Michael J.

    2017-03-01

    Recent hydrological modelling and Earth observations have located and quantified alarming rates of groundwater depletion worldwide. This depletion is primarily due to water withdrawals for irrigation, but its connection with the main driver of irrigation, global food consumption, has not yet been explored. Here we show that approximately eleven per cent of non-renewable groundwater use for irrigation is embedded in international food trade, of which two-thirds are exported by Pakistan, the USA and India alone. Our quantification of groundwater depletion embedded in the world’s food trade is based on a combination of global, crop-specific estimates of non-renewable groundwater abstraction and international food trade data. A vast majority of the world’s population lives in countries sourcing nearly all their staple crop imports from partners who deplete groundwater to produce these crops, highlighting risks for global food and water security. Some countries, such as the USA, Mexico, Iran and China, are particularly exposed to these risks because they both produce and import food irrigated from rapidly depleting aquifers. Our results could help to improve the sustainability of global food production and groundwater resource management by identifying priority regions and agricultural products at risk as well as the end consumers of these products.

  17. The new MCNP6 depletion capability

    SciTech Connect

    Fensin, M. L.; James, M. R.; Hendricks, J. S.; Goorley, J. T.

    2012-07-01

    The first MCNP based in-line Monte Carlo depletion capability was officially released from the Radiation Safety Information and Computational Center as MCNPX 2.6.0. Both the MCNP5 and MCNPX codes have historically provided a successful combinatorial geometry based, continuous energy, Monte Carlo radiation transport solution for advanced reactor modeling and simulation. However, due to separate development pathways, useful simulation capabilities were dispersed between both codes and not unified in a single technology. MCNP6, the next evolution in the MCNP suite of codes, now combines the capability of both simulation tools, as well as providing new advanced technology, in a single radiation transport code. We describe here the new capabilities of the MCNP6 depletion code dating from the official RSICC release MCNPX 2.6.0, reported previously, to the now current state of MCNP6. NEA/OECD benchmark results are also reported. The MCNP6 depletion capability enhancements beyond MCNPX 2.6.0 reported here include: (1) new performance enhancing parallel architecture that implements both shared and distributed memory constructs; (2) enhanced memory management that maximizes calculation fidelity; and (3) improved burnup physics for better nuclide prediction. MCNP6 depletion enables complete, relatively easy-to-use depletion calculations in a single Monte Carlo code. The enhancements described here help provide a powerful capability as well as dictate a path forward for future development to improve the usefulness of the technology. (authors)

  18. Capacitor charging FET switcher with controller to adjust pulse width

    DOEpatents

    Mihalka, Alex M.

    1986-01-01

    A switching power supply includes an FET full bridge, a controller to drive the FETs, a programmable controller to dynamically control final output current by adjusting pulse width, and a variety of protective systems, including an overcurrent latch for current control. Power MOSFETS are switched at a variable frequency from 20-50 kHz to charge a capacitor load from 0 to 6 kV. A ferrite transformer steps up the DC input. The transformer primary is a full bridge configuration with the FET switches and the secondary is fed into a high voltage full wave rectifier whose output is connected directly to the energy storage capacitor. The peak current is held constant by varying the pulse width using predetermined timing resistors and counting pulses. The pulse width is increased as the capacitor charges to maintain peak current. A digital ripple counter counts pulses, and after the desired number is reached, an up-counter is clocked. The up-counter output is decoded to choose among different resistors used to discharge a timing capacitor, thereby determining the pulse width. A current latch shuts down the supply on overcurrent due to either excessive pulse width causing transformer saturation or a major bridge fault, i.e., FET or transformer failure, or failure of the drive circuitry.

  19. The width of gamma-ray burst spectra

    NASA Astrophysics Data System (ADS)

    Axelsson, Magnus; Borgonovo, Luis

    2015-03-01

    The emission processes active in the highly relativistic jets of gamma-ray bursts (GRBs) remain unknown. In this paper, we propose a new measure to describe spectra: the width of the EFE spectrum, a quantity dependent only on finding a good fit to the data. We apply this to the full sample of GRBs observed by Fermi/Gamma-ray Burst Monitor (GBM) and Compton Gamma-ray Observatory/Burst and Transient Source Experiment (BATSE). The results from the two instruments are fully consistent. We find that the median widths of spectra from long and short GRBs are significantly different (chance probability <10-6). The width does not correlate with either duration or hardness, and this is thus a new, independent distinction between the two classes. Comparing the measured spectra with widths of spectra from fundamental emission processes - synchrotron and blackbody radiation - the results indicate that a large fraction of GRB spectra are too narrow to be explained by synchrotron radiation from a distribution of electron energies: for example, 78 per cent of long GRBs and 85 per cent of short GRBs are incompatible with the minimum width of standard slow cooling synchrotron emission from a Maxwellian distribution of electrons, with fast cooling spectra predicting even wider spectra. Photospheric emission can explain the spectra if mechanisms are invoked to give a spectrum much broader than a blackbody.

  20. Deciduous neonatal line: Width is associated with duration of delivery.

    PubMed

    Hurnanen, Jaana; Visnapuu, Vivian; Sillanpää, Matti; Löyttyniemi, Eliisa; Rautava, Jaana

    2017-02-01

    The delivery-related neonatal line (NNL) appears into the enamel of primary teeth and first permanent molars at birth and is a marker of live birth process. It varies in width and its location, is different in each deciduous tooth type, and is indicative of gestation time. It is unclear which triggers determine NNL at birth. Our objective was to investigate the effect of the duration and mode of delivery on NNL width. NNL of 129 teeth, a collection derived from a long-term, prospectively followed population cohort, was measured under light microscope. Altogether, 54 sections with most optimal plane of sectioning were analysed for the duration and mode of delivery. NNL was detected in 98% of the deciduous teeth with the median width of 9.63μm (min 3.16μm, max 27.58μm). A prolonged duration of vaginal delivery was highly significantly associated with a narrower NNL (r=-0.41, p=0.0097). No significant association was found between the width of NNL and mode of delivery (p=0.36). NNL is demonstrable in virtually all deciduous teeth. The width seems to be inversely proportional to the duration of delivery. Causes of the inverse proportion are speculated to result from altered amelogenesis induced by prolonged and intensified delivery-associated stress. Further research is needed to clarify the underlying mechanisms.

  1. Capacitor charging FET switcher with controller to adjust pulse width

    NASA Astrophysics Data System (ADS)

    Mihalka, A. M.

    1986-04-01

    A switching power supply includes an FET full bridge, a controller to drive the FETs, a programmable controller to dynamically control final output current by adjusting pulse width, and a variety of protective systems, including an overcurrent latch for current control. Power MOSFETS are switched at a variable frequency from 20 to 50 kHz to charge a capacitor load from 0 to 6 kV. A ferrite transformer steps up the dc input. The transformer primary is a full bridge configuration with the FET switches and the secondary is fed into a high voltage full wave rectifier whose output is connected directly to the energy storage capacitor. The peak current is held constant by varying the pulse width using predetermined timing resistors and counting pulses. The pulse width is increased as the capacitor charges to maintain peak current. A digital ripple counter counts pulses, and after the desired number is reached, an up-counter is clocked. The up-counter output is decoded to choose among different resistors used to discharge a timing capacitor, thereby determining the pulse width. A current latch shuts down the supply on overcurrent due to either excessive pulse width causing transformer saturation or a major bridge fault, i.e., FET or transformer failure, or failure of the drive circuitry.

  2. Depletion in the Star-Forming Core IRAM04191

    NASA Astrophysics Data System (ADS)

    Wootten, A.; Mangum, J. G.; Wiseman, J.; Fuller, G. A.

    2002-12-01

    IRAM 04191+1522 numbers among the least evolved low mass protostars known. Belloche, André, Despois, and Blinder (Astronomy and Astrophysics, v393, 927, 2002) found the envelope to lie in a transition stage, with one portion showing constant rotational velocity mediated by magnetic braking and another inner region showing conserved angular momentum suggestive of protostellar collapse. Imaging of the interior 10000 AU in the ammonia lines (Wootten, Wiseman, and Fuller 2001, BAAS v33, 1394) revealed a 2100 AU region devoid of ammonia emission centered on the star. Here we present images made on similar scales with the OVRO Millimeter Array in the 1->0 lines of the molecular ions N2H+ and H13CO+. The former shows a ringlike structure coincident with the hole in the ammonia distribution. The latter shows only amorphous structure more distant from the central protostar. A sufficient explanation of these morphologies is that the nitrogen-bearing molecules vanish owing to depletion onto grains in the cold (13K) central region of high (n>1.5 x 106 cm-3) density. We expected that N2H+ should survive depletion to higher densities. If N2 is also depleted, as seems likely, kinematics of the central portion of this young protostar will be extremely difficult to measure. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. Observations at the OVRO Millimeter Array are supported by the National Science Foundation under Grant No.9981546

  3. Ego depletion in visual perception: Ego-depleted viewers experience less ambiguous figure reversal.

    PubMed

    Wimmer, Marina C; Stirk, Steven; Hancock, Peter J B

    2017-02-22

    This study examined the effects of ego depletion on ambiguous figure perception. Adults (N = 315) received an ego depletion task and were subsequently tested on their inhibitory control abilities that were indexed by the Stroop task (Experiment 1) and their ability to perceive both interpretations of ambiguous figures that was indexed by reversal (Experiment 2). Ego depletion had a very small effect on reducing inhibitory control (Cohen's d = .15) (Experiment 1). Ego-depleted participants had a tendency to take longer to respond in Stroop trials. In Experiment 2, ego depletion had small to medium effects on the experience of reversal. Ego-depleted viewers tended to take longer to reverse ambiguous figures (duration to first reversal) when naïve of the ambiguity and experienced less reversal both when naïve and informed of the ambiguity. Together, findings suggest that ego depletion has small effects on inhibitory control and small to medium effects on bottom-up and top-down perceptual processes. The depletion of cognitive resources can reduce our visual perceptual experience.

  4. The modality effect of ego depletion: Auditory task modality reduces ego depletion.

    PubMed

    Li, Qiong; Wang, Zhenhong

    2016-08-01

    An initial act of self-control that impairs subsequent acts of self-control is called ego depletion. The ego depletion phenomenon has been observed consistently. The modality effect refers to the effect of the presentation modality on the processing of stimuli. The modality effect was also robustly found in a large body of research. However, no study to date has examined the modality effects of ego depletion. This issue was addressed in the current study. In Experiment 1, after all participants completed a handgrip task, one group's participants completed a visual attention regulation task and the other group's participants completed an auditory attention regulation task, and then all participants again completed a handgrip task. The ego depletion phenomenon was observed in both the visual and the auditory attention regulation task. Moreover, participants who completed the visual task performed worse on the handgrip task than participants who completed the auditory task, which indicated that there was high ego depletion in the visual task condition. In Experiment 2, participants completed an initial task that either did or did not deplete self-control resources, and then they completed a second visual or auditory attention control task. The results indicated that depleted participants performed better on the auditory attention control task than the visual attention control task. These findings suggest that altering task modality may reduce ego depletion. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  5. Ozone depletion and chlorine loading potentials

    NASA Technical Reports Server (NTRS)

    Pyle, John A.; Wuebbles, Donald J.; Solomon, Susan; Zvenigorodsky, Sergei; Connell, Peter; Ko, Malcolm K. W.; Fisher, Donald A.; Stordal, Frode; Weisenstein, Debra

    1991-01-01

    The recognition of the roles of chlorine and bromine compounds in ozone depletion has led to the regulation or their source gases. Some source gases are expected to be more damaging to the ozone layer than others, so that scientific guidance regarding their relative impacts is needed for regulatory purposes. Parameters used for this purpose include the steady-state and time-dependent chlorine loading potential (CLP) and the ozone depletion potential (ODP). Chlorine loading potentials depend upon the estimated value and accuracy of atmospheric lifetimes and are subject to significant (approximately 20-50 percent) uncertainties for many gases. Ozone depletion potentials depend on the same factors, as well as the evaluation of the release of reactive chlorine and bromine from each source gas and corresponding ozone destruction within the stratosphere.

  6. Depletion performance of layered reservoirs without crossflow

    SciTech Connect

    Fetkovich, M.J.; Works, A.M.; Thrasher, T.S. ); Bradley, M.D. )

    1990-09-01

    This paper presents a study of the rate/time and pressure/cumulative-production depletion performance of a two-layered gas reservoir producing without crossflow. The gas reservoir has produced for more than 20 years at an effectively constant wellbore pressure, thus giving continuously declining rate/time and pressure/cumulative-production data for analysis. The field data demonstrates that Arps depletion-decline exponents between 0.5 and 1 can be obtained with a no-crossflow, layered reservoir description. Rate-vs.-time and pressure-vs.-cumulative-production predictions were developed from both 2D numerical and simplified tank models of a two layered, no-crossflow system. These results demonstrate the effects of changes in reservoir layer volumes, permeability, and skin on the depletion performance.

  7. Neutral depletion and the helicon density limit

    SciTech Connect

    Magee, R. M.; Galante, M. E.; Carr, J. Jr.; Lusk, G.; McCarren, D. W.; Scime, E. E.

    2013-12-15

    It is straightforward to create fully ionized plasmas with modest rf power in a helicon. It is difficult, however, to create plasmas with density >10{sup 20} m{sup −3}, because neutral depletion leads to a lack of fuel. In order to address this density limit, we present fast (1 MHz), time-resolved measurements of the neutral density at and downstream from the rf antenna in krypton helicon plasmas. At the start of the discharge, the neutral density underneath the antenna is reduced to 1% of its initial value in 15 μs. The ionization rate inferred from these data implies that the electron temperature near the antenna is much higher than the electron temperature measured downstream. Neutral density measurements made downstream from the antenna show much slower depletion, requiring 14 ms to decrease by a factor of 1/e. Furthermore, the downstream depletion appears to be due to neutral pumping rather than ionization.

  8. Global Warming: Lessons from Ozone Depletion

    NASA Astrophysics Data System (ADS)

    Hobson, Art

    2010-11-01

    My teaching and textbook have always covered many physics-related social issues, including stratospheric ozone depletion and global warming. The ozone saga is an inspiring good-news story that's instructive for solving the similar but bigger problem of global warming. Thus, as soon as students in my physics literacy course at the University of Arkansas have developed a conceptual understanding of energy and of electromagnetism, including the electromagnetic spectrum, I devote a lecture (and a textbook section) to ozone depletion and another lecture (and section) to global warming. Humankind came together in 1986 and quickly solved, to the extent that humans can solve it, ozone depletion. We could do the same with global warming, but we haven't and as yet there's no sign that we will. The parallel between the ozone and global warming cases, and the difference in outcomes, are striking and instructive.

  9. Self-regulation, ego depletion, and inhibition.

    PubMed

    Baumeister, Roy F

    2014-12-01

    Inhibition is a major form of self-regulation. As such, it depends on self-awareness and comparing oneself to standards and is also susceptible to fluctuations in willpower resources. Ego depletion is the state of reduced willpower caused by prior exertion of self-control. Ego depletion undermines inhibition both because restraints are weaker and because urges are felt more intensely than usual. Conscious inhibition of desires is a pervasive feature of everyday life and may be a requirement of life in civilized, cultural society, and in that sense it goes to the evolved core of human nature. Intentional inhibition not only restrains antisocial impulses but can also facilitate optimal performance, such as during test taking. Self-regulation and ego depletion- may also affect less intentional forms of inhibition, even chronic tendencies to inhibit. Broadly stated, inhibition is necessary for human social life and nearly all societies encourage and enforce it. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Analysis of edge stability for models of heat flux width

    DOE PAGES

    Makowski, Michael A.; Lasnier, Charles J.; Leonard, Anthony W.; ...

    2017-05-12

    Detailed measurements of the ne, and Te, and Ti profiles in the vicinity of the separatrix of ELMing H-mode discharges have been used to examine plasma stability at the extreme edge of the plasma and assess stability dependent models of the heat flux width. The results are strongly contrary to the critical gradient model, which posits that a ballooning instability determines a gradient scale length related to the heat flux width. The results of this analysis are not sensitive to the choice of location to evaluate stability. Significantly, it is also found that the results are completely consistent with themore » heuristic drift model for the heat flux width. Here the edge pressure gradient scales with plasma density and is proportional to the pressure gradient inferred from the equilibrium in accordance with the predictions of that theory.« less

  11. Area-width scaling in generalised Motzkin paths

    NASA Astrophysics Data System (ADS)

    Haug, Nils; Prellberg, Thomas; Siudem, Grzegorz

    2017-09-01

    We consider a generalised version of Motzkin paths, where horizontal steps have length ℓ, with ℓ being a fixed positive integer. We first give the general functional equation for the area-width generating function of this model. Using a heuristic ansatz, we then derive the area-width scaling behaviour in terms of a scaling function in one variable for the special cases of Dyck, (standard) Motzkin and Schröder paths, before generalising our approach to arbitrary ℓ. We then rigorously derive the tricritical scaling of Schröder paths by applying the generalised method of steepest descents to the known exact solution for their area-width generating function. Our results show that for Dyck and Schröder paths, the heuristic scaling ansatz reproduces the rigorous results.

  12. Why momentum width matters for atom interferometry with Bragg pulses

    NASA Astrophysics Data System (ADS)

    Szigeti, S. S.; Debs, J. E.; Hope, J. J.; Robins, N. P.; Close, J. D.

    2012-02-01

    We theoretically consider the effect of the atomic source's momentum width on the efficiency of Bragg mirrors and beamsplitters and, more generally, on the phase sensitivity of Bragg pulse atom interferometers. By numerical optimization, we show that an atomic cloud's momentum width places a fundamental upper bound on the maximum transfer efficiency of a Bragg mirror pulse, and furthermore limits the phase sensitivity of a Bragg pulse atom interferometer. We quantify these momentum width effects, and precisely compute how mirror efficiencies and interferometer phase sensitivities vary as functions of Bragg order and source type. Our results and methodology allow for an efficient optimization of Bragg pulses and the comparison of different atomic sources, and will help in the design of large momentum transfer Bragg mirrors and beamsplitters for use in atom-based inertial sensors.

  13. Radial widths, optical depths, and eccentricities of the Uranian rings

    NASA Astrophysics Data System (ADS)

    Nicholson, P. D.; Matthews, K.; Goldreich, P.

    1982-02-01

    Observations of the stellar occultation by the Uranian rings of 15/16 August 1980 are used to estimate radial widths and normal optical depths for segments of rings 6, 5, 4, alpha, beta, eta, gamma, and delta. Synthetic occultation profiles are generated to match the observed light curves. A review of published data confirms the existence of width-radius relations for rings alpha and beta, and indicates that the optical depths of these two rings vary inversely with their radial widths. Masses are obtained for rings alpha and beta, on the assumption that differential precession is prevented by their self-gravity. A quantitative comparison of seven epsilon-ring occultation profiles obtained over a period of 3.4 yr reveals a consistent structure, which may reflect the presence of unresolved gaps and subrings.

  14. Fast and Robust Nanocellulose Width Estimation Using Turbidimetry.

    PubMed

    Shimizu, Michiko; Saito, Tsuguyuki; Nishiyama, Yoshiharu; Iwamoto, Shinichiro; Yano, Hiroyuki; Isogai, Akira; Endo, Takashi

    2016-10-01

    The dimensions of nanocelluloses are important factors in controlling their material properties. The present study reports a fast and robust method for estimating the widths of individual nanocellulose particles based on the turbidities of their water dispersions. Seven types of nanocellulose, including short and rigid cellulose nanocrystals and long and flexible cellulose nanofibers, are prepared via different processes. Their widths are calculated from the respective turbidity plots of their water dispersions, based on the theory of light scattering by thin and long particles. The turbidity-derived widths of the seven nanocelluloses range from 2 to 10 nm, and show good correlations with the thicknesses of nanocellulose particles spread on flat mica surfaces determined using atomic force microscopy.

  15. Morphodynamics structures induced by variations of the channel width

    NASA Astrophysics Data System (ADS)

    Duro, Gonzalo; Crosato, Alessandra; Tassi, Pablo

    2014-05-01

    In alluvial channels, forcing effects, such as a longitudinally varying width, can induce the formation of steady bars (Olesen, 1984). The type of bars that form, such as alternate, central or multiple, will mainly depend on the local flow width-to-depth ratio and on upstream conditions (Struiksma et al., 1985). The effects on bar formation of varying the channel width received attention only recently and investigations, based on flume experiments and mathematical modelling, are mostly restricted to small longitudinal sinusoidal variations of the channel width (e.g. Repetto et al., 2002; Wu and Yeh, 2005, Zolezzi et al., 2012; Frascati and Lanzoni, 2013). In this work, we analyze the variations in equilibrium bed topography in a longitudinal width-varying channel with characteristic scales of the Waal River (The Netherlands) using two different 2D depth-averaged morphodynamic models, one based on the Delft3D code and one on Telemac-Mascaret system. In particular, we explore the effects of changing the wavelength of sinusoidal width variations in a straight channel, focusing on the effects of the spatial lag between bar formation and forcing that is observed in numerical models and laboratory experiments (e.g. Crosato et al, 2011). We extend the investigations to finite width variations in which longitudinal changes of the width-to-depth ratio are such that they may affect the type of bars that become unstable (alternate, central or multiple bars). Numerical results are qualitatively validated with field observations and the resulting morphodynamic pattern is compared with the physics-based predictor of river bar modes by Crosato and Mosselman (2009). The numerical models are finally used to analyse the experimental conditions of Wu and Yeh (2005). The study should be seen as merely exploratory. The aim is to investigate possible approaches for future research aiming at assessing the effects of artificial river widening and narrowing to control bar formation in

  16. Interatomic Coulombic decay widths of helium trimer: Ab initio calculations

    SciTech Connect

    Kolorenč, Přemysl; Sisourat, Nicolas

    2015-12-14

    We report on an extensive study of interatomic Coulombic decay (ICD) widths in helium trimer computed using a fully ab initio method based on the Fano theory of resonances. Algebraic diagrammatic construction for one-particle Green’s function is utilized for the solution of the many-electron problem. An advanced and universal approach to partitioning of the configuration space into discrete states and continuum subspaces is described and employed. Total decay widths are presented for all ICD-active states of the trimer characterized by one-site ionization and additional excitation of an electron into the second shell. Selected partial decay widths are analyzed in detail, showing how three-body effects can qualitatively change the character of certain relaxation transitions. Previously unreported type of three-electron decay processes is identified in one class of the metastable states.

  17. Estimate of cusp loss width in multicusp negative ion source

    NASA Astrophysics Data System (ADS)

    Morishita, T.; Ogasawara, M.; Hatayama, A.

    1998-02-01

    Expression of cusp loss width derived by Bosch and Merlino is applied to JAERI's Kamaboko source. The width is related to the ambipolar diffusion coefficient across the cusp magnetic field. Electron-ion collision is found 1.2-7.4 times larger as compared with electron-neutral collision. Averaged cusp magnetic field in the diffusion coefficient is taken as a parameter in the simulation code for Kamaboko source. When the averaged magnetic field is 48 G, simulation results agree well with JAERI's experiment in a wide range of pressure and arc power variation. The value of 48 G is reasonable from the consideration of confining the equation of ion source plasma. The obtained width is about 10 times the value evaluated by two times ion Larmor radius on the surface of cusp magnet.

  18. Similarity of Stream Width Distributions Across Headwater Systems

    NASA Astrophysics Data System (ADS)

    Allen, G. H.; Pavelsky, T.; Barefoot, E. A.; Tashie, A.; Butman, D. E.

    2016-12-01

    The morphology and abundance of streams control the rates of hydraulic and biogeochemical exchange between streams, groundwater, and the atmosphere. In large river systems, studies have used remote sensing to quantify river morphology, and have found that the relationship between river width and abundance is fractal, such that narrow rivers are proportionally more common than wider rivers. However, in headwater systems (stream order 1-3), where many biogeochemical reactions are most rapid, the relationship between stream width and abundance is unknown, reducing the certainty of biogeochemical flux estimates. To constrain this uncertainty, we surveyed two components of stream morphology (wetted stream width and length) in seven physiographically contrasting stream networks in Kings Creek in Konza Prarie, KS; Sagehen Creek in the N. Sierra Nevada Mtns., CA; Elder Creek in Angelo Coast Range Preserve, CA; Caribou Creek in the Caribou Poker Creek Research Watershed, AK; V40 Stream, NZ; Blue Duck Creek, NZ; Stony Creek in Duke Forest, NC. To assess temporal variations, we also surveyed stream geometry in a subcatchment of Stony Creek six times over a range of moderate streamflow conditions (discharge less than 90 percentile of gauge record). Here we show a strikingly consistent gamma statistical distribution of stream width in all surveys and a characteristic most abundant stream width of 32±7 cm independent of flow conditions or basin size. This consistency is remarkable given the substantial physical diversity among the studied catchments. We propose a model that invokes network topology theory and downstream hydraulic geometry to show that, as active drainage networks expand and contract in response to changes in streamflow, the most abundant stream width remains approximately static. This framework can be used to better extrapolate stream size and abundance from large rivers to small headwater streams, with significant impact on understanding of the hydraulic

  19. New parameter in diagnosis of acute appendicitis: Platelet distribution width

    PubMed Central

    Dinc, Bulent; Oskay, Alten; Dinc, Selcan Enver; Bas, Bilge; Tekin, Sabri

    2015-01-01

    AIM: To investigate the diagnostic accuracy of the mean platelet volume and platelet distribution width in acute appendicitis. METHODS: This retrospective, case-controlled study compared 295 patients with acute appendicitis (Group I), 100 patients with other intra-abdominal infections (Group II), and 100 healthy individuals (Group III) between January 2012 and January 2013. The age, gender, and white blood cell count, neutrophil percentage, mean platelet volume, and platelet distribution width values from blood samples were compared among the groups. Statistical analyses were performed using SPSS for Windows 21.0 software. In addition, the sensitivity, specificity, positive and negative predictive values and likelihood ratios, and diagnostic accuracy were calculated. RESULTS: The mean ages of patients were 29.9 ± 12.0 years for Group I, 31.5 ± 14.0 years for Group II, and 30.4 ± 13.0 years for Group III. Demographic features such as age and gender were not significantly different among the groups. White blood cell count, neutrophil percentage and platelet distribution width were significantly higher in Group I compared to groups II and III (P < 0.05). Diagnostically, the sensitivity, specificity and diagnostic accuracy were 73.1%, 94.0%, and 78% for white blood cell count, 70.0%, 96.0%, and 76.0% for neutrophil percentage, 29.5%, 49.0%, and 34.0% for mean platelet volume, and 97.1%, 93.0%, and 96.0% for platelet distribution width, respectively. The highest diagnostic accuracy detected was for platelet distribution width between Group I and Group III (P < 0.01). CONCLUSION: Platelet distribution width analysis can be used for diagnosis of acute appendicitis without requiring additional tests, thus reducing the cost and loss of time. PMID:25684947

  20. Prediction of battery depletion in implanted pacemakers

    PubMed Central

    Davies, Geoffrey; Siddons, Harold

    1973-01-01

    By the use of a measuring oscilloscope and the standard electrocardiogram limb leads the degree of battery depletion in an implanted pacemaker can be estimated. A formula based on readings obtained by this means has been used to determine when Devices fixed rate pacemakers should be removed. Laboratory tests show that 90% of their useful life is obtained by this means and it proved possible to extend the period of implantation from an arbitrary 24 months to 25 to 34 months without failure from battery depletion. PMID:4731110

  1. Seasonal oxygen depletion in Chesapeake Bay

    SciTech Connect

    Taft, J.L.; Hartwig, E.O.; Loftus, R.

    1980-12-01

    The spring freshet increases density stratification in Chesapeake Bay and minimizes oxygen transfer from the surface to the deep layer so that waters below 10 m depth experience oxygen depletion which may lead to anoxia during June to September. Respiration in the water of the deep layer is the major factor contributing to oxygen depletion. Benthic respiration seems secondary. Organic matter from the previous year which has settled into the deep layer during winter provides most of the oxygen demand but some new production in the surface layer may sink and thus supplement the organic matter accumulated in the deep layer.

  2. Low Sulfur Depletion in Photodissociation Regions

    NASA Astrophysics Data System (ADS)

    Goicoechea, J. R.; Pety, J.; Gerin, M.; Teyssier, D.; Roueff, E.; Hily-Blant, P.

    2006-06-01

    Sulfur is an abundant element which remains undepleted in diffuse interstellar gas but it is historically assumed to deplete (by factors of ˜1000) on grains at higher densities. Photodissociation regions (PDRs) are an interesting intermediate medium between translucent and dark clouds where the energetics and dynamics are dominated by an illuminating FUV radiation field, and thus they can provide some new insights about the sulfur depletion problem. In this work we present our latest studies on CS and HCS^+ photochemistry, excitation and radiative transfer in the Horsehead PDR, allowing us to infer the sulfur abundance.

  3. Experimental Stark widths and shifts of Ti II spectral lines

    NASA Astrophysics Data System (ADS)

    Manrique, J.; Aguilera, J. A.; Aragón, C.

    2016-10-01

    Stark widths and shifts of Ti II lines with wavelengths in the range 2500-4600 Å have been determined by laser-induced breakdown spectroscopy. The temperature and electron density of the plasma vary in the ranges 11 970-15 520 K and (2.0-7.2) × 1017 cm-3, respectively, for the different measurement instants from 0.6 to 1.8 μs. The samples used are fused glass discs with different titanium concentrations, selected to control the self-absorption of the lines. The Stark widths and shifts are compared with the experimental and theoretical data available in the literature.

  4. Direct measurement of the W boson decay width

    NASA Astrophysics Data System (ADS)

    Abazov, V. M.; Abbott, B.; Abdesselam, A.; Abolins, M.; Abramov, V.; Acharya, B. S.; Adams, D. L.; Adams, M.; Ahmed, S. N.; Alexeev, G. D.; Alton, A.; Alves, G. A.; Anderson, E. W.; Arnoud, Y.; Avila, C.; Baarmand, M. M.; Babintsev, V. V.; Babukhadia, L.; Bacon, T. C.; Baden, A.; Baldin, B.; Balm, P. W.; Banerjee, S.; Barberis, E.; Baringer, P.; Barreto, J.; Bartlett, J. F.; Bassler, U.; Bauer, D.; Bean, A.; Beaudette, F.; Begel, M.; Belyaev, A.; Beri, S. B.; Bernardi, G.; Bertram, I.; Besson, A.; Beuselinck, R.; Bezzubov, V. A.; Bhat, P. C.; Bhatnagar, V.; Bhattacharjee, M.; Blazey, G.; Blekman, F.; Blessing, S.; Boehnlein, A.; Bojko, N. I.; Bolton, T. A.; Borcherding, F.; Bos, K.; Bose, T.; Brandt, A.; Breedon, R.; Briskin, G.; Brock, R.; Brooijmans, G.; Bross, A.; Buchholz, D.; Buehler, M.; Buescher, V.; Burtovoi, V. S.; Butler, J. M.; Canelli, F.; Carvalho, W.; Casey, D.; Casilum, Z.; Castilla-Valdez, H.; Chakraborty, D.; Chan, K. M.; Chekulaev, S. V.; Cho, D. K.; Choi, S.; Chopra, S.; Christenson, J. H.; Chung, M.; Claes, D.; Clark, A. R.; Coney, L.; Connolly, B.; Cooper, W. E.; Coppage, D.; Crépé-Renaudin, S.; Cummings, M. A.; Cutts, D.; Davis, G. A.; de, K.; de Jong, S. J.; Demarteau, M.; Demina, R.; Demine, P.; Denisov, D.; Denisov, S. P.; Desai, S.; Diehl, H. T.; Diesburg, M.; Doulas, S.; Ducros, Y.; Dudko, L. V.; Duensing, S.; Duflot, L.; Dugad, S. R.; Duperrin, A.; Dyshkant, A.; Edmunds, D.; Ellison, J.; Eltzroth, J. T.; Elvira, V. D.; Engelmann, R.; Eno, S.; Eppley, G.; Ermolov, P.; Eroshin, O. V.; Estrada, J.; Evans, H.; Evdokimov, V. N.; Fahland, T.; Fein, D.; Ferbel, T.; Filthaut, F.; Fisk, H. E.; Fisyak, Y.; Flattum, E.; Fleuret, F.; Fortner, M.; Fox, H.; Frame, K. C.; Fu, S.; Fuess, S.; Gallas, E.; Galyaev, A. N.; Gao, M.; Gavrilov, V.; Genik, R. J.; Genser, K.; Gerber, C. E.; Gershtein, Y.; Gilmartin, R.; Ginther, G.; Gómez, B.; Goncharov, P. I.; González Solís, J. L.; Gordon, H.; Goss, L. T.; Gounder, K.; Goussiou, A.; Graf, N.; Grannis, P. D.; Green, J. A.; Greenlee, H.; Greenwood, Z. D.; Grinstein, S.; Groer, L.; Grünendahl, S.; Gupta, A.; Gurzhiev, S. N.; Gutierrez, G.; Gutierrez, P.; Hadley, N. J.; Haggerty, H.; Hagopian, S.; Hagopian, V.; Hall, R. E.; Hansen, S.; Hauptman, J. M.; Hays, C.; Hebert, C.; Hedin, D.; Heinmiller, J. M.; Heinson, A. P.; Heintz, U.; Hildreth, M. D.; Hirosky, R.; Hobbs, J. D.; Hoeneisen, B.; Huang, Y.; Iashvili, I.; Illingworth, R.; Ito, A. S.; Jaffré, M.; Jain, S.; Jesik, R.; Johns, K.; Johnson, M.; Jonckheere, A.; Jöstlein, H.; Juste, A.; Kahl, W.; Kahn, S.; Kajfasz, E.; Kalinin, A. M.; Karmanov, D.; Karmgard, D.; Kehoe, R.; Khanov, A.; Kharchilava, A.; Kim, S. K.; Klima, B.; Knuteson, B.; Ko, W.; Kohli, J. M.; Kostritskiy, A. V.; Kotcher, J.; Kothari, B.; Kotwal, A. V.; Kozelov, A. V.; Kozlovsky, E. A.; Krane, J.; Krishnaswamy, M. R.; Krivkova, P.; Krzywdzinski, S.; Kubantsev, M.; Kuleshov, S.; Kulik, Y.; Kunori, S.; Kupco, A.; Kuznetsov, V. E.; Landsberg, G.; Lee, W. M.; Leflat, A.; Leggett, C.; Lehner, F.; Leonidopoulos, C.; Li, J.; Li, Q. Z.; Lima, J. G.; Lincoln, D.; Linn, S. L.; Linnemann, J.; Lipton, R.; Lucotte, A.; Lueking, L.; Lundstedt, C.; Luo, C.; Maciel, A. K.; Madaras, R. J.; Malyshev, V. L.; Manankov, V.; Mao, H. S.; Marshall, T.; Martin, M. I.; Mayorov, A. A.; McCarthy, R.; McMahon, T.; Melanson, H. L.; Merkin, M.; Merritt, K. W.; Miao, C.; Miettinen, H.; Mihalcea, D.; Mishra, C. S.; Mokhov, N.; Mondal, N. K.; Montgomery, H. E.; Moore, R. W.; Mostafa, M.; da Motta, H.; Mutaf, Y.; Nagy, E.; Nang, F.; Narain, M.; Narasimham, V. S.; Naumann, N. A.; Neal, H. A.; Negret, J. P.; Nomerotski, A.; Nunnemann, T.; O'Neil, D.; Oguri, V.; Olivier, B.; Oshima, N.; Padley, P.; Pan, L. J.; Papageorgiou, K.; Parashar, N.; Partridge, R.; Parua, N.; Paterno, M.; Patwa, A.; Pawlik, B.; Peters, O.; Pétroff, P.; Piegaia, R.; Pope, B. G.; Popkov, E.; Prosper, H. B.; Protopopescu, S.; Przybycien, M. B.; Qian, J.; Raja, R.; Rajagopalan, S.; Ramberg, E.; Rapidis, P. A.; Reay, N. W.; Reucroft, S.; Ridel, M.; Rijssenbeek, M.; Rizatdinova, F.; Rockwell, T.; Roco, M.; Royon, C.; Rubinov, P.; Ruchti, R.; Rutherfoord, J.; Sabirov, B. M.; Sajot, G.; Santoro, A.; Sawyer, L.; Schamberger, R. D.; Schellman, H.; Schwartzman, A.; Sen, N.; Shabalina, E.; Shivpuri, R. K.; Shpakov, D.; Shupe, M.; Sidwell, R. A.; Simak, V.; Singh, H.; Sirotenko, V.; Slattery, P.; Smith, E.; Smith, R. P.; Snihur, R.; Snow, G. R.; Snow, J.; Snyder, S.; Solomon, J.; Song, Y.; Sorín, V.; Sosebee, M.; Sotnikova, N.; Soustruznik, K.; Souza, M.; Stanton, N. R.; Steinbrück, G.; Stephens, R. W.; Stoker, D.; Stolin, V.; Stone, A.; Stoyanova, D. A.; Strang, M. A.; Strauss, M.; Strovink, M.; Stutte, L.; Sznajder, A.; Talby, M.; Taylor, W.; Tentindo-Repond, S.; Tripathi, S. M.; Trippe, T. G.; Turcot, A. S.; Tuts, P. M.; Vaniev, V.; van Kooten, R.; Varelas, N.; Vertogradov, L. S.; Villeneuve-Seguier, F.; Volkov, A. A.; Vorobiev, A. P.; Wahl, H. D.; Wang, H.; Wang, Z.-M.; Warchol, J.; Watts, G.; Wayne, M.; Weerts, H.; White, A.; White, J. T.; Whiteson, D.; Wijngaarden, D. A.; Willis, S.; Wimpenny, S. J.; Womersley, J.; Wood, D. R.; Xu, Q.; Yamada, R.; Yamin, P.; Yasuda, T.; Yatsunenko, Y. A.; Yip, K.; Youssef, S.; Yu, J.; Zanabria, M.; Zhang, X.; Zheng, H.; Zhou, B.; Zhou, Z.; Zielinski, M.; Zieminska, D.; Zieminski, A.; Zutshi, V.; Zverev, E. G.; Zylberstejn, A.

    2002-08-01

    Based on 85 pb-1 data of pp¯ collisions at (s)=1.8 TeV collected using the DØ detector at Fermilab during the 1994-1995 run of the Tevatron, we present a direct measurement of the total decay width of the W boson ΓW. The width is determined from the transverse mass spectrum in the W-->e+νe decay channel and found to be ΓW=2.23+0.15- 0.14(stat)+/-0.10(syst) GeV, consistent with the expectation from the standard model.

  5. Width effects in transonic flow over a rectangular cavity

    DOE PAGES

    Beresh, Steven J.; Wagner, Justin L.; Henfling, John F.; ...

    2015-07-24

    A previous experiment by the present authors studied the flow over a finite-width rectangular cavity at freestream Mach numbers 1.5–2.5. In addition, this investigation considered the influence of three-dimensional geometry that is not replicated by simplified cavities that extend across the entire wind-tunnel test section. The latter configurations have the attraction of easy optical access into the depths of the cavity, but they do not reproduce effects upon the turbulent structures and acoustic modes due to the length-to-width ratio, which is becoming recognized as an important parameter describing the nature of the flow within narrower cavities.

  6. Characteristics of pulse width for an enhanced second harmonic generation

    NASA Astrophysics Data System (ADS)

    Zhang, Yun; Hyodo, Masaharu; Okada-Shudo, Yoshiko; Zhu, Yun; Wang, Xiaoyang; Zhu, Yong; Wang, Guiling; Chen, Chuangtian; Watanabe, Shuntaro; Watanabe, Masayoshi

    2017-03-01

    Temporal characteristics of a cavity enhancement second harmonic (SH) generation for picosecond laser pulse are investigated. We experimentally measured pulse width changes that were indued by group velocity mismatching (GVM), SH process, and enhancement cavity. It indicates that the generated pulse width is a combined effect of the GVM and SH process. Meanwhile, the effect of the enhancement cavity can be avoided by controlling its free spectrum range. A interferometric autocorrelator with a KBBF-PCD as nonlinear crystal is also composed and this extends the measurement light wavelength below 410 nm.

  7. Fjords in viscous fingering: selection of width and opening scale

    SciTech Connect

    Mineev-weinstein, Mark; Ristroph, Leif; Thrasher, Matthew; Swinney, Harry

    2008-01-01

    Our experiments on viscous fingering of air into oil contained between closely spaced plates reveal two selection rules for the fjords of oil that separate fingers of air. (Fjords are the building blocks of solutions of the zero-surface-tension Laplacian growth equation.) Experiments in rectangular and circular geometries yield fjords with base widths {lambda}{sub c}/2, where {lambda}{sub c} is the most unstable wavelength from a linear stability analysis. Further, fjords open at an angle of 8.0{sup o}{+-}1.0{sup o}. These selection rules hold for a wide range of pumping rates and fjord lengths, widths, and directions.

  8. On the radial width of CMEs between 0.1 and 0.4 AU

    NASA Astrophysics Data System (ADS)

    Savani, N. P.; Forsyth, R. J.; Rouillard, A. P.; Owens, M. J.; Davies, J. A.

    2009-04-01

    The launch of the two STEREO spacecraft in 2006 has heralded a new era of opportunities to make remote observations of interplanetary coronal mass ejections (ICMEs). An example CME on the 16th February 2008 with an approximately circular cross section was tracked through successive images obtained by the Heliospheric Imager (HI) instrument onboard the STEREO-A spacecraft. The cylindrical nature of force-free constant alpha flux ropes is used to determine the radial size of the CME. The radial velocity and longitude of propagation are determined. With these parameters known, the radial size is calculated from the images taking projection effects into account. A power law is obtained for the resulting radial width behaviour with heliocentric distance as the CME travels between 0.1 and 0.4 AU. We compare our results to those obtained in published studies based on in-situ spacecraft observations of ICMEs between 0.3 and 1.0 AU.

  9. The temporal evolution of the large equatorial plasma depletions observed during the 29-30 October 2003 storm

    NASA Astrophysics Data System (ADS)

    Kil, Hyosub; Paxton, Larry J.

    2010-03-01

    This study investigates the temporal evolution of the large plasma depletions observed by ROCSAT-1 and DMSP near 295°E during the 29-30 October 2003 storm. The presence of a penetration electric field around the detection time of the large plasma depletions is supported by the observation of high upward ion drift velocity and formation of an intense equatorial ionization anomaly in the American sector. However, these ionospheric disturbances occur in broad longitude regions; a short-range polarization electric field may adequately explain the creation of the large plasma depletions. The penetration electric field may trigger the Rayleigh-Taylor instability and produce abnormally large plasma depletions during the storm. The TIMED/GUVI and CHAMP observations provide an insight for the evolution of the large depletions several hours after their formation. The large depletions appear as arch-shaped emission depletions in the TIMED/GUVI image and as symmetric depletions paired in the magnetic north and south in the CHAMP observation. These characteristics can be explained by the "plasma depletion shell" phenomenon (Kil et al., 2009) produced by the westward shear flow of the ionosphere during the storm.

  10. 48 CFR 52.223-11 - Ozone-Depleting Substances.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Ozone-Depleting Substances....223-11 Ozone-Depleting Substances. As prescribed in 23.804(a), insert the following clause: Ozone-Depleting Substances (MAY 2001) (a) Definition. Ozone-depleting substance, as used in this clause, means...

  11. 48 CFR 52.223-11 - Ozone-Depleting Substances.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 2 2013-10-01 2013-10-01 false Ozone-Depleting Substances....223-11 Ozone-Depleting Substances. As prescribed in 23.804(a), insert the following clause: Ozone-Depleting Substances (MAY 2001) (a) Definition. Ozone-depleting substance, as used in this clause, means...

  12. 48 CFR 52.223-11 - Ozone-Depleting Substances.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 2 2011-10-01 2011-10-01 false Ozone-Depleting Substances....223-11 Ozone-Depleting Substances. As prescribed in 23.804(a), insert the following clause: Ozone-Depleting Substances (MAY 2001) (a) Definition. Ozone-depleting substance, as used in this clause, means...

  13. 48 CFR 52.223-11 - Ozone-Depleting Substances.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 2 2014-10-01 2014-10-01 false Ozone-Depleting Substances....223-11 Ozone-Depleting Substances. As prescribed in 23.804(a), insert the following clause: Ozone-Depleting Substances (MAY 2001) (a) Definition. Ozone-depleting substance, as used in this clause, means...

  14. 48 CFR 52.223-11 - Ozone-Depleting Substances.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 2 2012-10-01 2012-10-01 false Ozone-Depleting Substances....223-11 Ozone-Depleting Substances. As prescribed in 23.804(a), insert the following clause: Ozone-Depleting Substances (MAY 2001) (a) Definition. Ozone-depleting substance, as used in this clause, means...

  15. Note: Broadly tunable all-fiber ytterbium laser with 0.05 nm spectral width based on multimode interference filter

    SciTech Connect

    Mukhopadhyay, Pranab K. Gupta, Pradeep K.; Singh, Amarjeet; Sharma, Sunil K.; Bindra, Kushvinder S.; Oak, Shrikant M.

    2014-05-15

    A multimode interference filter with narrow transmission bandwidth and large self-imaging wavelength interval is constructed and implemented in an ytterbium doped fiber laser in all-fiber format for broad wavelength tunability as well as narrow spectral width of the output beam. The peak transmission wavelength of the multimode interference filter was tuned with the help of a standard in-fiber polarization controller. With this simple mechanism more than 30 nm (1038 nm–1070 nm) tuning range is demonstrated. The spectral width of the output beam from the laser was measured to be 0.05 nm.

  16. Two- and three-dimensional CT measurements of urinary calculi length and width: a comparative study.

    PubMed

    Lidén, Mats; Thunberg, Per; Broxvall, Mathias; Geijer, Håkan

    2015-04-01

    The standard imaging procedure for a patient presenting with renal colic is unenhanced computed tomography (CT). The CT measured size has a close correlation to the estimated prognosis for spontaneous passage of a ureteral calculus. Size estimations of urinary calculi in CT images are still based on two-dimensional (2D) reformats. To develop and validate a calculus oriented three-dimensional (3D) method for measuring the length and width of urinary calculi and to compare the calculus oriented measurements of the length and width with corresponding 2D measurements obtained in axial and coronal reformats. Fifty unenhanced CT examinations demonstrating urinary calculi were included. A 3D symmetric segmentation algorithm was validated against reader size estimations. The calculus oriented size from the segmentation was then compared to the estimated size in axial and coronal 2D reformats. The validation showed 0.1 ± 0.7 mm agreement against reference measure. There was a 0.4 mm median bias for 3D estimated calculus length compared to 2D (P < 0.001), but no significant bias for 3D width compared to 2D. The length of a calculus in axial and coronal reformats becomes underestimated compared to 3D if its orientation is not aligned to the image planes. Future studies aiming to correlate calculus size with patient outcome should use a calculus oriented size estimation. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  17. Real-Time Measurement of Width and Height of Weld Beads in GMAW Processes.

    PubMed

    Pinto-Lopera, Jesús Emilio; S T Motta, José Mauricio; Absi Alfaro, Sadek Crisostomo

    2016-09-15

    Associated to the weld quality, the weld bead geometry is one of the most important parameters in welding processes. It is a significant requirement in a welding project, especially in automatic welding systems where a specific width, height, or penetration of weld bead is needed. This paper presents a novel technique for real-time measuring of the width and height of weld beads in gas metal arc welding (GMAW) using a single high-speed camera and a long-pass optical filter in a passive vision system. The measuring method is based on digital image processing techniques and the image calibration process is based on projective transformations. The measurement process takes less than 3 milliseconds per image, which allows a transfer rate of more than 300 frames per second. The proposed methodology can be used in any metal transfer mode of a gas metal arc welding process and does not have occlusion problems. The responses of the measurement system, presented here, are in a good agreement with off-line data collected by a common laser-based 3D scanner. Each measurement is compare using a statistical Welch's t-test of the null hypothesis, which, in any case, does not exceed the threshold of significance level α = 0.01, validating the results and the performance of the proposed vision system.

  18. Real-Time Measurement of Width and Height of Weld Beads in GMAW Processes

    PubMed Central

    Pinto-Lopera, Jesús Emilio; S. T. Motta, José Mauricio; Absi Alfaro, Sadek Crisostomo

    2016-01-01

    Associated to the weld quality, the weld bead geometry is one of the most important parameters in welding processes. It is a significant requirement in a welding project, especially in automatic welding systems where a specific width, height, or penetration of weld bead is needed. This paper presents a novel technique for real-time measuring of the width and height of weld beads in gas metal arc welding (GMAW) using a single high-speed camera and a long-pass optical filter in a passive vision system. The measuring method is based on digital image processing techniques and the image calibration process is based on projective transformations. The measurement process takes less than 3 milliseconds per image, which allows a transfer rate of more than 300 frames per second. The proposed methodology can be used in any metal transfer mode of a gas metal arc welding process and does not have occlusion problems. The responses of the measurement system, presented here, are in a good agreement with off-line data collected by a common laser-based 3D scanner. Each measurement is compare using a statistical Welch’s t-test of the null hypothesis, which, in any case, does not exceed the threshold of significance level α = 0.01, validating the results and the performance of the proposed vision system. PMID:27649198

  19. Image

    SciTech Connect

    Marsh, Amber; Harsch, Tim; Pitt, Julie; Firpo, Mike; Lekin, April; Pardes, Elizabeth

    2007-08-31

    The computer side of the IMAGE project consists of a collection of Perl scripts that perform a variety of tasks; scripts are available to insert, update and delete data from the underlying Oracle database, download data from NCBI's Genbank and other sources, and generate data files for download by interested parties. Web scripts make up the tracking interface, and various tools available on the project web-site (image.llnl.gov) that provide a search interface to the database.

  20. Measurement of the laser pulse width on the microscope objective plane by modulated autocorrelation method.

    PubMed

    Cannone, F; Chirico, G; Baldini, G; Diaspro, A

    2003-05-01

    We report on the construction details of a compact autocorrelator set-up for the measurement of the width of infrared laser pulses at the focal plane of a microscope for two-photon excitation fluorescence imaging. One of the novelties of the set-up, which leads to an improved measurement accuracy, is the use of a modulation technique that is achieved by mounting one of the interferometer mirrors on a loudspeaker driven by a sinusoidal bias at low frequency. A non-linear least-square routine selects only that part of the fluorescence signal that is modulated at the same frequency as the loudspeaker bias. To further increase the accuracy, the laser pulse width is obtained from a series of measurements at different values of the modulation bias. The autocorrelator is a compact single bread-board (10 x 20 cm); it is PC-controlled both for the acquisition and the analysis of the data and can be coupled to different ports of the microscope. The increase in the pulse width measured for three different ports of the microscope is well accounted for by the group velocity dispersion and the glass thickness of the optics found along these paths.

  1. Beam width estimation of microwave antennas using lock-in infrared thermography

    NASA Astrophysics Data System (ADS)

    Muzaffar, Khalid; Tuli, Suneet; Koul, Shiban

    2015-09-01

    The beam width of microwave antennas can be easily determined using infrared thermography. A thin absorption screen made up of some carbon loaded polymer is placed in front of a microwave antenna. The electromagnetic waves impinging the screen are partially absorbed by it, resulting in temperature rise of this screen. This temperature rise is monitored by an infrared camera. These infra red images of the temperature distribution are identical to the power distribution of the incident electromagnetic field at the screen location. The distance between half power points on the main lobe of the radiation pattern at the screen location in two orthogonal directions (E- and H-planes) can be easily found. From these distances the half power beam widths in both E- and H-planes can be calculated. Further from these beam widths, directivity is also calculated. The experiments were carried with a patch antenna radiating at 2.45 GHz. In order to show the repeatability of the results, experiments were carried for different distances between patch antenna and absorption screen. A great agreement is seen between simulation, measurement and experimental (thermographic) results. The microwave source is modulated at a low frequency so as to avoid the lateral spread of heat on the absorption screen and to permit lock-in detection of temperature distribution.

  2. Interatomic Coulombic decay in a He dimer: Ab initio potential-energy curves and decay widths

    SciTech Connect

    Kolorenc, Premysl; Kryzhevoi, Nikolai V.; Sisourat, Nicolas; Cederbaum, Lorenz S.

    2010-07-15

    The energy gained by either of the two helium atoms in a helium dimer through simultaneous ionization and excitation can be efficiently transferred to the other helium atom, which then ionizes. The respective relaxation process called interatomic Coulombic decay (ICD) is the subject of the present paper. Specifically, we are interested in ICD of the lowest of the ionized excited states, namely, the He{sup +}(n=2)He states, for which we calculated the relevant potential-energy curves and the interatomic decay widths. The full-configuration interaction method was used to obtain the potential-energy curves. The decay widths were computed by utilizing the Fano ansatz, Green's-function methods, and the Stieltjes imaging technique. The behavior of the decay widths with the interatomic distance is examined and is elucidated, whereby special emphasis is given to the asymptotically large interatomic separations. Our calculations show that the electronic ICD processes dominate over the radiative decay mechanisms over a wide range of interatomic distances. The ICD in the helium dimer has recently been measured by Havermeier et al. [Phys. Rev. Lett. 104, 133401 (2010)]. The impact of nuclear dynamics on the ICD process is extremely important and is discussed by Sisourat et al. [Nat. Phys. 6, 508 (2010)] based on the ab initio data computed in the present paper.

  3. An OCD perspective of line edge and line width roughness metrology

    NASA Astrophysics Data System (ADS)

    Bonam, Ravi; Muthinti, Raja; Breton, Mary; Liu, Chi-Chun; Sieg, Stuart; Seshadri, Indira; Saulnier, Nicole; Shearer, Jeffrey; Patlolla, Raghuveer; Huang, Huai

    2017-03-01

    Metrology of nanoscale patterns poses multiple challenges that range from measurement noise, metrology errors, probe size etc. Optical Metrology has gained a lot of significance in the semiconductor industry due to its fast turn around and reliable accuracy, particularly to monitor in-line process variations. Apart from monitoring critical dimension, thickness of films, there are multiple parameters that can be extracted from Optical Metrology models3. Sidewall angles, material compositions etc., can also be modeled to acceptable accuracy. Line edge and Line Width roughness are much sought of metrology following critical dimension and its uniformity, although there has not been much development in them with optical metrology. Scanning Electron Microscopy is still used as a standard metrology technique for assessment of Line Edge and Line Width roughness. In this work we present an assessment of Optical Metrology and its ability to model roughness from a set of structures with intentional jogs to simulate both Line edge and Line width roughness at multiple amplitudes and frequencies. We also present multiple models to represent roughness and extract relevant parameters from Optical metrology. Another critical aspect of optical metrology setup is correlation of measurement to a complementary technique to calibrate models. In this work, we also present comparison of roughness parameters extracted and measured with variation of image processing conditions on a commercially available CD-SEM tool.

  4. A method for determining the drift velocity of plasma depletions in the equatorial ionosphere using far-ultraviolet spacecraft observations: initial results

    NASA Astrophysics Data System (ADS)

    England, S. L.; Immel, T. J.; Park, S. H.; Frey, H. U.; Mende, S. B.

    2007-12-01

    The Far-Ultraviolet Imager (IMAGE-FUV) on-board the NASA IMAGE satellite has been used to observe plasma depletions in the nightside equatorial ionosphere. Observations from periods around spacecraft apogee, during which equatorial regions are visible for several hours, have allowed the velocity of these plasma depletions to be determined. A new method for determining the velocity of these depletions using an image analysis technique, Tracking Of Airglow Depletions (TOAD), has been developed. TOAD allows the objective identification and tracking of depletions. The automation of this process has also allowed for the tracking of a greater number of depletions than previously achieved without requiring any human input, which shows that TOAD is suitable for use with large data sets and for future routine monitoring of the ionosphere from space. Furthermore, this allows the drift velocities of each depletion to be determined as a function of magnetic latitude as well as local time. Previous ground-based airglow observations from a small number of locations have indicated that the drift velocities of depletions may vary rapidly with magnetic latitude. Here we shall present the first results from TOAD of this shear in drift velocities from our global sample of depletion drift velocities.

  5. Band width and multiple-angle valence-state mapping of diamond

    SciTech Connect

    Jimenez, I.; Terminello, L.J.; Sutherland, D.G.J.

    1997-04-01

    The band width may be considered the single most important parameter characterizing the electronic structure of a solid. The ratio of band width and Coulomb repulsion determines how correlated or delocalized an electron system is. Some of the most interesting solids straddle the boundary between localized and delocalized, e.g. the high-temperature superconductors. The bulk of the band calculations available today is based on local density functional (DF) theory. Even though the Kohn-Sham eigenvalues from that theory do not represent the outcome of a band-mapping experiment, they are remarkably similar to the bands mapped via photoemission. Strictly speaking, one should use an excited state calculation that takes the solid`s many-body screening response to the hole created in photoemission into account. Diamond is a useful prototype semiconductor because of its low atomic number and large band width, which has made it a long-time favorite for testing band theory. Yet, the two experimental values of the band width of diamond have error bars of {+-}1 eV and differ by 3.2 eV. To obtain an accurate valence band width for diamond, the authors use a band-mapping method that collects momentum distributions instead of the usual energy distributions. This method has undergone extensive experimental and theoretical tests in determining the band width of lithium fluoride. An efficient, imaging photoelectron spectrometer is coupled with a state-of-the-art undulator beam line at the Advanced Light Source to allow collection of a large number of data sets. Since it takes only a few seconds to take a picture of the photoelectrons emitted into a 84{degrees} cone, the authors can use photon energies as high as 350 eV where the cross section for photoemission from the valence band is already quite low, but the emitted photoelectrons behave free-electron-like. This make its much easier to locate the origin of the inter-band transitions in momentum space.

  6. Direct Visualization of an Impurity Depletion Zone

    NASA Technical Reports Server (NTRS)

    Chernov, Alex A.; Garcia-Ruiz, Juan Ma; Thomas, Bill R.

    2000-01-01

    When a crystal incorporates more impurity per unit of its volume than the impurity concentration in solution, the solution in vicinity of the growing crystal is depleted with respect to the impurity I,2. With a stagnant solution, e. g. in microgravity or gels, an impurity depletion zone expands as the crystal grows and results in greater purity in most of the outer portion of the crystal than in the core. Crystallization in gel provides an opportunity to mimic microgravity conditions and visualize the impurity depletion zone. Colorless, transparent apoferritin (M congruent to 450 KDa) crystals were grown in the presence of red holoferritin dimer as a microheterogeneous impurity (M congruent to 900 KDa) within agarose gel by counterdiffusion with Cd(2+) precipitant. Preferential trapping of dimers, (distribution coefficient K = 4 (exp 1,2)) results in weaker red color around the crystals grown in the left tube in the figure as compared to the control middle tube without crystals. The left and the middle tubes contain colored ferritin dimers, the right tube contains colored trimers. The meniscus in the left tube separate gel (below) and liquid solution containing Cd(2+) (above). Similar solutions, though without precipitants, were present on top of the middle and right tube allowing diffusion of dimers and trimers. The area of weaker color intensity around crystals directly demonstrates overlapped impurity depletion zones.

  7. Global Warming: Lessons from Ozone Depletion

    ERIC Educational Resources Information Center

    Hobson, Art

    2010-01-01

    My teaching and textbook have always covered many physics-related social issues, including stratospheric ozone depletion and global warming. The ozone saga is an inspiring good-news story that's instructive for solving the similar but bigger problem of global warming. Thus, as soon as students in my physics literacy course at the University of…

  8. Global Warming: Lessons from Ozone Depletion

    ERIC Educational Resources Information Center

    Hobson, Art

    2010-01-01

    My teaching and textbook have always covered many physics-related social issues, including stratospheric ozone depletion and global warming. The ozone saga is an inspiring good-news story that's instructive for solving the similar but bigger problem of global warming. Thus, as soon as students in my physics literacy course at the University of…

  9. Kinetics of the depletion of trichloroethene

    SciTech Connect

    Barrio-Lage, G.; Parson, F.Z.; Nassar, R.S.

    1987-04-01

    The depletion of trichloroethene (TCE) was studied in microcosms containing water and three types of natural sediment ranging in composition from highly organic to a calcareous sedimentary rock. The depletion rates varied slightly in the different sediments. The first-order rate constant k/sub 1/ for the depletion of TCE ranged from 8.7 x 10/sup -4/ and 4.9 x 10/sup -4/ h/sup -1/ in soils contaminated with TCE prior to microcosm preparation to 3.4 x 10/sup -4/ and 4.6 x 10/sup -4/ h/sup -1/ for soils with a large organic content to 3.2 x 10/sup -4/ h/sup -1/ for crushed rock microcosms. Depletion was found to follow nonlinear forms of Michaelis-Menten kinetics in the organic sediments; however, microcosms containing crushed rock and water followed a linear form of the equation. K/sub m/ values were found to be dependent on the percent of total organic carbon in the sediment. 16 references, 4 figures, 2 tables.

  10. Neutral depletion versus repletion due to ionization

    SciTech Connect

    Fruchtman, A.; Makrinich, G.; Raimbault, J.-L.; Liard, L.; Rax, J.-M.; Chabert, P.

    2008-05-15

    Recent theoretical analyses which predicted unexpected effects of neutral depletion in both collisional and collisionless plasmas are reviewed. We focus on the depletion of collisionless neutrals induced by strong ionization of a collisionless plasma and contrast this depletion with the effect of strong ionization on thermalized neutrals. The collisionless plasma is analyzed employing a kinetic description. The collisionless neutrals and the plasma are coupled through volume ionization and wall recombination only. The profiles of density and pressure both of the plasma and of the neutral-gas and the profile of the ionization rate are calculated. It is shown that for collisionless neutrals the ionization results in neutral depletion, while when neutrals are thermalized the ionization induces a maximal neutral-density at the discharge center, which we call neutral repletion. The difference between the two cases stems from the relation between the neutral density and pressure. The pressure of the collisionless neutral-gas turns out to be maximal where its density is minimal, in contrast to the case of a thermalized neutral gas.

  11. Soil moisture depletion patterns around scattered trees

    Treesearch

    Robert R. Ziemer

    1968-01-01

    Soil moisture was measured around an isolated mature sugar pine tree (Pinus lambertiana Dougl.) in the mixed conifer forest type of the north central Sierra Nevada, California, from November 1965 to October 1966. From a sequence of measurements, horizontal and vertical soil moisture profiles were developed. Estimated soil moisture depletion from the 61-foot radius plot...

  12. Demonstration of jackhammer incorporating depleted uranium

    SciTech Connect

    Fischer, L E; Hoard, R W; Carter, D L; Saculla, M D; Wilson, G V

    2000-04-01

    The United States Government currently has an abundance of depleted uranium (DU). This surplus of about 1 billion pounds is the result of an enrichment process using gaseous diffusion to produce enriched and depleted uranium. The enriched uranium has been used primarily for either nuclear weapons for the military or nuclear fuel for the commercial power industry. Most of the depleted uranium remains at the enrichment process plants in the form of depleted uranium hexafluoride (DUF{sub 6}). The Department of Energy (DOE) recently began a study to identify possible commercial applications for the surplus material. One of these potential applications is to use the DU in high-density strikers/hammers in pneumatically driven tools, such as jack hammers and piledrivers to improve their impulse performance. The use of DU could potentially increase tunneling velocity and excavation into target materials with improved efficiency. This report describes the efforts undertaken to analyze the particulars of using DU in two specific striking applications: the jackhammer and chipper tool.

  13. Dissolution Treatment of Depleted Uranium Waste

    SciTech Connect

    Gates-Anderson, D D; Laue, C A; Fitch, T E

    2004-02-09

    Researchers at LLNL have developed a 3-stage process that converts pyrophoric depleted uranium metal turnings to a solidified final product that can be transported to and buried at a permitted land disposal site. The three process stages are: (1) pretreatment; (2) dissolution; and (3) solidification. Each stage was developed following extensive experimentation. This report presents the results of their experimental studies.

  14. Contrasts between Antarctic and Arctic ozone depletion.

    PubMed

    Solomon, Susan; Portmann, Robert W; Thompson, David W J

    2007-01-09

    This work surveys the depth and character of ozone depletion in the Antarctic and Arctic using available long balloon-borne and ground-based records that cover multiple decades from ground-based sites. Such data reveal changes in the range of ozone values including the extremes observed as polar air passes over the stations. Antarctic ozone observations reveal widespread and massive local depletion in the heart of the ozone "hole" region near 18 km, frequently exceeding 90%. Although some ozone losses are apparent in the Arctic during particular years, the depth of the ozone losses in the Arctic are considerably smaller, and their occurrence is far less frequent. Many Antarctic total integrated column ozone observations in spring since approximately the 1980s show values considerably below those ever observed in earlier decades. For the Arctic, there is evidence of some spring season depletion of total ozone at particular stations, but the changes are much less pronounced compared with the range of past data. Thus, the observations demonstrate that the widespread and deep ozone depletion that characterizes the Antarctic ozone hole is a unique feature on the planet.

  15. Width of the {phi} meson in nuclear matter

    SciTech Connect

    Polyanskiy, A. Yu.; Hartmann, M.; Kiselev, Yu. T.; Paryev, E. Ya.; Buescher, M.; Chiladze, D.; Dymov, S. N.; Dzyuba, A. A.; Gebel, R.; Hejny, V.; Kaempfer, B.; Keshelashvili, I.; Koptev, V. P.; Lorentz, B.; Maeda, Y.; Merzliakov, S. I.; and others

    2012-01-15

    The ratios of the cross sections for {phi}-meson production induced by 2.83-GeV protons on Cu, Ag, and Au nuclei to the respective cross section for C nuclei were measured at the ANKE-COSY facility in the momentum range of 0.6-1.6 GeV/c and the angular range of 0 Degree-Sign -8 Degree-Sign . The product {phi} mesons were identified by their decay {phi} {yields} K{sup +}K{sup -}. The procedure used to separate kaon pairs was described in detail, and all sources of the background and their contribution to the resulting error in the values found for the above cross-section ratios were analyzed. The A dependence of the cross section for {phi}-meson production was shown to obey the A{sup 0.56{+-}0.03} law. The total width of the {phi} meson at a normal nuclear density was extracted from a comparison of the measured cross-section ratios with the results of calculations based on two theoretical models. The resulting width value exceeds substantially both the vacuum width and the width expected in the absence of the nuclear-matter effect on the properties of the {phi} meson.

  16. An Improved determination of the width of the top quark

    SciTech Connect

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D.; Alkhazov, Georgiy D.; Alton, Andrew K.; Alverson, George O.; Aoki, Masato; Askew, Andrew Warren; /Florida State U. /Stockholm U.

    2012-01-01

    We present an improved determination of the total width of the top quark, {Lambda}{sub t}, using 5.4 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The total width {Lambda}{sub t} is extracted from the partial decay width {Lambda}(t {yields} Wb) and the branching fraction {Beta}(t {yields} Wb). {Lambda}(t {yields} Wb) is obtained from the t-channel single top quark production cross section and {Beta}(t {yields} Wb) is measured in t{bar t} events. For a top mass of 172.5 GeV, the resulting width is {Lambda}{sub t} = 2.00{sub -0.43}{sup +0.47} GeV. This translates to a top-quark lifetime of {tau}{sub t} = (3.29{sub -0.63}{sup +0.90}) x 10{sup -25} s. We also extract an improved direct limit on the CKM matrix element 0.81 < |V{sub tb}| {le} 1 at 95% C.L. and a limit of |V{sub tb'}| < 0.59 for a high mass fourth generation bottom quark assuming unitarity of the fourth generation quark mixing matrix.

  17. Width adjustment: relative dominance in unstable alluvial streams

    USGS Publications Warehouse

    Simon, Andrew

    1994-01-01

    The mechanisms that control the relative dominance of width adjustment in unstable streams are described. Specifically, the role of the following factors affecting the fluvial environment were investigated: vertical processes and fluvial action, bed-material particle, cohesive strength of bank material, and riparian vegetation.

  18. 13. DETAIL: A CLOSEUP VIEW OF TWO UNEQUAL WIDTH CONCRETE ...

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

    13. DETAIL: A CLOSE-UP VIEW OF TWO UNEQUAL WIDTH CONCRETE BRACKETS AND THE LARGE CAST ANCONE WHICH SUPPORTS A QUIRK IN THE CONCRETE BALUSTRADE. - Delphi Bridge on U.S. Route 421, Spanning Deer Creek at U.S. Route 421, Delphi, Carroll County, IN

  19. Detonation cell widths in hydrogen-air-diluent mixtures

    SciTech Connect

    Stamps, D.W.

    1990-01-01

    In this paper I report on the influence of steam and carbon dioxide on the detonability of hydrogen-air mixtures. Data were obtained on the detonation cell width in a heated detonation tube that is 0.43 m in diameter and 13.1 m long. The detonation cell widths were correlated using a characteristic length calculated from a chemical kinetic model. The addition of either diluent to a hydrogen-air mixture increased the cell width for all equivalence ratios. For equal diluent concentrations, however, carbon dioxide not only yielded larger increases in the cell width than steam, but its efficacy relative to steam was predicted to increase with increasing concentration. The range of detonable hydrogen concentrations in a hydrogen-air mixture initially at 1 atm pressure was found to be between 11.6 percent and 74.9 percent for mixtures at 20{degree}C and 9.4 percent and 76.9 percent for mixtures at 100{degree}C. The detonation limit was between 38.8 percent and 40.5 percent steam for a stoichiometric hydrogen-air-steam mixture initially at 100{degree}C and 1 atm. 10 refs., 4 figs., 1 tab.

  20. The Height + Width Rule in Children's Judgments of Quantity.

    ERIC Educational Resources Information Center

    Anderson, Norman H.; Cuneo, Diane O.

    1978-01-01

    In eight experiments, judgments of rectangle area by five-year-olds followed a reliable adding rule: height + width. In collateral work, the children judged the amount of liquid in a glass by a height-only rule. Implications for the Piagetian theories of centration and compensation are drawn. (SJL)

  1. An Empirical Expression for the Line Widths of Ammonia

    NASA Technical Reports Server (NTRS)

    Brown, Linda R.; Peterson, Dean B.

    1994-01-01

    The hydrogen-broadened line widths of 116 (sup 14)NH(sub 3) ground state transitions have been measured at 0.006 cm(sup -1) resolution using a Bruker spectrometer in the 24 to 210 cm(sup -1) region. The rotational variation of the experimental widths with J(sup '),K(sup ') = 1,0 to 10,10 has been reproduced to 2.4 % using an heuristically derived expression of the form

    gamma = a(sub 0) + a(sub 1) J(sup ') + a (sub 2) K(sup ') + a(sub 3) J(sup ')(sup 2) + a(sub 4) J(sup ') K(sup ')

    where J(sup ') and K(sup ') are the lower state symmetric top quantum numbers. This function has also been applied to the measured widths of the 58 transitions of nu(sub 1) at 3 (micro)m, each broadened by N(sub 2), O(sub 2), Ar, H(sub 2), and He. The rms of the observed minus calculated widths are 5% or better for the five foreign broadeners. The values of the fitted constants suggest that for some broadeners the expression might also be written as

    gamma = a(sub 0) + b(sub 1) J(sup ') + b(sub 2)(J(sup ' )- K(sup ')) + b(sub 3) J(sup ')(J(sup ') - K(sup '))

    .

  2. Influence of terrace widths on Au(111) reconstruction

    NASA Astrophysics Data System (ADS)

    Chauraud, D.; Durinck, J.; Drouet, M.; Vernisse, L.; Bonneville, J.; Coupeau, C.

    2017-07-01

    The effect of steps on the herringbone pattern appearing at the Au (111 ) surface is explored. Scanning tunneling microscopy investigations show that the number of alternating fcc and hcp regions decreases with the decreasing width of the terrace, in fair agreement with atomistic simulations. It is demonstrated that the steps locally release the tensile surface stresses, leading to a reorganization of the herringbone pattern.

  3. Backscattering patterns of step index optical fibers: angular width.

    PubMed

    Ho, P S; Marhic, M E; Epstein, M

    1975-11-01

    Angular widths of laser backscattering patterns from optical fibers with thin claddings due to rays reflected by core-cladding interface are investigated. Calculated and measured values are presented and found to be in good agreement. A summary of different backscattering patterns from clad fibers is given.

  4. Improved determination of the width of the top quark

    SciTech Connect

    Abazov V. M.; Abbott B.; Acharya B. S.; Adams M.; Adams T.; Alexeev G. D.; Alkhazov G.; Alton A.; Alverson G.; Aoki M.; Askew A.; Asman B.; Atkins S.; Atramentov O.; Augsten K.; Avila C.; BackusMayes J.; Badaud F.; Bagby L.; Baldin B.; Bandurin D. V.; Banerjee S.; Barberis E.; Baringer P.; Barreto J.; Bartlett J. F.; Bassler U.; Bazterra V.; Bean A.; Begalli M.; Belanger-Champagne C.; Bellantoni L.; Beri S. B.; Bernardi G.; Bernhard R.; Bertram I.; Besancon M.; Beuselinck R.; Bezzubov V. A.; Bhat P. C.; Bhatia S.; Bhatnagar V.; Blazey G.; Blessing S.; Bloom K.; Boehnlein A.; Boline D.; Boos E. E.; Borissov G.; Bose T.; Brandt A.; Brandt O.; Brock R.; Brooijmans G.; Bross A.; Brown D.; Brown J.; Bu X. B.; Buehler M.; Buescher V.; Bunichev V.; Burdin S.; Burnett T. H.; Buszello C. P.; Calpas B.; Camacho-Perez E.; Carrasco-Lizarraga M. A.; Casey C. K.; Castilla-Valdez H.; Chakrabarti S.; Chakraborty D.; Chan M.; Chandra A.; Chapon E.; Chen G.; Chevalier-Thery S.; Cho D. K.; Cho S. W.; Choi S.; Choudhary B.; Cihangir S.; Claes D.; Clutter J.; Cooke M.; Cooper W. E.; Corcoran M.; Couderc F.; Cousinou M. -C.; Croc A.; Cutts D.; Das A.; Davies G.; de Jong S. J.; De La Cruz-Burelo E.; Deliot F.; Demina R.; Denisov D.; Denisov S. P.; Desai S.; Deterre C.; DeVaughan K.; Diehl H. T.; Diesburg M.; Ding P. F.; Dominguez A.; Dorland T.; Dubey A.; Dudko L. V.; Duggan D.; Duperrin A.; Dutt S.; Dyshkant A.; Eads M.; Edmunds D.; Ellison J.; Elvira V. D.; Enari Y.; Evans H.; Evdokimov A.; Evdokimov V. N.; Facini G.; Ferbel T.; Fiedler F.; Filthaut F.; Fisher W.; Fisk H. E.; Fortner M.; Fox H.; Fuess S.; Garcia-Bellido A.; Garcia-Guerra G. A.; Gavrilov V.; Gay P.; Geng W.; Gerbaudo D.; Gerber C. E.; Gershtein Y.; Ginther G.; Golovanov G.; Goussiou A.; Graf C. P.; Grannis P. D.; Greder S.; Greenlee H.; Greenwood Z. D.; Gregores E. M.; Grenier G.; Gris Ph.; Grivaz J. -F.; Grohsjean A.; Gruenendahl S.; Gruenewald M. W.; Guillemin T.; Gutierrez G.; Gutierrez P.; Haas A.; Hagopian S.; Haley J.; Han L.; Harder K.; Harel A.; Hauptman J. M.; Hays J.; Head T.; Hebbeker T.; Hedin D.; Hegab H.; Heinson A. P.; Heintz U.; Hensel C.; La Cruz I. Heredia-De; Herner K.; Hesketh G.; Hildreth M. D.; Hirosky R.; Hoang T.; Hobbs J. D.; Hoeneisen B.; Hohlfeld M.; Hubacek Z.; Hynek V.; Iashvili I.; Ilchenko Y.; Illingworth R.; Ito A. S.; Jabeen S.; Jaffre M.; Jamin D.; Jayasinghe A.; Jesik R.; Johns K.; Johnson M.; Jonckheere A.; Jonsson P.; Joshi J.; Jung A. W.; Juste A.; Kaadze K.; Kajfasz E.; Karmanov D.; Kasper P. A.; Katsanos I.; Kehoe R.; Kermiche S.; Khalatyan N.; Khanov A.; Kharchilava A.; Kharzheev Y. N.; Kohli J. M.; Kozelov A. V.; Kraus J.; Kulikov S.; Kumar A.; Kupco A.; Kurca T.; Kuzmin V. A.; Lammers S.; Landsberg G.; Lebrun P.; Lee H. S.; Lee S. W.; Lee W. M.; Lellouch J.; Li H.; Li L.; Li Q. Z.; Lietti S. M.; Lim J. K.; Lincoln D.; Linnemann J.; Lipaev V. V.; Lipton R.; Liu Y.; Lobodenko A.; Lokajicek M.; de Sa R. Lopes; Lubatti H. J.; Luna-Garcia R.; Lyon A. L.; Maciel A. K. A.; Mackin D.; Madar R.; Magana-Villalba R.; Malik S.; Malyshev V. L.; Maravin Y.; Martinez-Ortega J.; McCarthy R.; McGivern C. L.; Meijer M. M.; Melnitchouk A.; Menezes D.; Mercadante P. G.; Merkin M.; et al.

    2012-05-04

    We present an improved determination of the total width of the top quark, {Gamma}{sub t}, using 5.4 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The total width {Gamma}{sub t} is extracted from the partial decay width {Gamma}(t {yields} Wb) and the branching fraction {Beta}(t {yields} Wb). {Gamma}(t {yields} Wb) is obtained from the t-channel single top-quark production cross section and {Beta}(t {yields} Wb) is measured in t{bar t} events. For a top mass of 172.5 GeV, the resulting width is {Gamma}{sub t} = 2.00{sub -0.43}{sup +0.47} GeV. This translates to a top-quark lifetime of {tau}{sub t} = (3.29{sub -0.63}{sup +0.90}) x 10{sup -25} s. We also extract an improved direct limit on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix element 0.81 < |V{sub tb}| {le} 1 at 95% C.L. and a limit of |V{sub tb}| < 0.59 for a high-mass fourth-generation bottom quark assuming unitarity of the fourth-generation quark-mixing matrix.

  5. An Empirical Expression for the Line Widths of Ammonia

    NASA Technical Reports Server (NTRS)

    Brown, Linda R.; Peterson, Dean B.

    1994-01-01

    The hydrogen-broadened line widths of 116 (sup 14)NH(sub 3) ground state transitions have been measured at 0.006 cm(sup -1) resolution using a Bruker spectrometer in the 24 to 210 cm(sup -1) region. The rotational variation of the experimental widths with J(sup '),K(sup ') = 1,0 to 10,10 has been reproduced to 2.4 % using an heuristically derived expression of the form

    gamma = a(sub 0) + a(sub 1) J(sup ') + a (sub 2) K(sup ') + a(sub 3) J(sup ')(sup 2) + a(sub 4) J(sup ') K(sup ')

    where J(sup ') and K(sup ') are the lower state symmetric top quantum numbers. This function has also been applied to the measured widths of the 58 transitions of nu(sub 1) at 3 (micro)m, each broadened by N(sub 2), O(sub 2), Ar, H(sub 2), and He. The rms of the observed minus calculated widths are 5% or better for the five foreign broadeners. The values of the fitted constants suggest that for some broadeners the expression might also be written as

    gamma = a(sub 0) + b(sub 1) J(sup ') + b(sub 2)(J(sup ' )- K(sup ')) + b(sub 3) J(sup ')(J(sup ') - K(sup '))

    .

  6. Shifts and widths of Feshbach resonances in atomic waveguides

    NASA Astrophysics Data System (ADS)

    Saeidian, Shahpoor; Melezhik, Vladimir S.; Schmelcher, Peter

    2012-12-01

    We develop and analyze a theoretical model which yields the shifts and widths of Feshbach resonances in an atomic waveguide. It is based on a multichannel approach for confinement-induced resonances (CIRs) and atomic transitions in the waveguides in the multimode regime. In this scheme we replace the single-channel scalar interatomic interaction by the four-channel tensorial potential modeling resonances of broad, narrow, and overlapping character according to the two-channel parametrization of Lange [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.79.013622 79, 013622 (2009)]. As an input the experimentally known parameters of Feshbach resonances in the absence of the waveguide are used. We calculate the shifts and widths of s-, d-, and g-wave magnetic Feshbach resonances of Cs atoms emerging in harmonic waveguides as CIRs and resonant enhancement of the transmission at zeros of the free space scattering length. We have found the linear dependence of the width of the resonance on the longitudinal atomic momentum and quadratic dependence on the waveguide width. Our model opens possibilities for quantitative studies of the scattering processes in ultracold atomic gases in waveguides beyond the framework of s-wave resonant scattering.

  7. A local basal area adjustment for crown width prediction

    Treesearch

    Don C. Bragg

    2001-01-01

    Nonlinear crown width regressive equations were developed for 24 species common to the upper Lake States of Michigan, Minnesota, and Wisconsin. Of the species surveyed, 15 produced statistically significant (P 0.05) local basal area effect coefficients showing a reduction in crown...

  8. Evaluation of a Simple Theoretical Expression for Hadley Cell Width

    NASA Astrophysics Data System (ADS)

    Rees, K.; Garrett, T. J.; Reichler, T.; Staten, P. W.

    2016-12-01

    The latitudinal width of Earth's Hadley cell has a simple expression that is a function of the planetary radius, and the atmosphere's angular velocity, stability, and depth: the cell width varies as the square root of the Brunt-Vaisala frequency and the tropospheric depth such that a deep, stable atmosphere extends further poleward. There are multiple avenues to this expression based on either the dynamics (Schneider (1977); Held (2000)) or the statistical mechanics (Garrett et al (2016)) of the cell. Here, we contrast these approaches and test the expression for application to other planetary bodies within the solar system. In general, we find the expression accounts for the wide range of cell widths, ranging from very narrow (Jupiter) to very wide (Titan). However, there is a choice of atmospheric depth to be considered in the calculation, and we find that the effective depth that leads to best agreement with observed cell widths is closest to the tropospheric density scale height rather than the depth of the troposphere itself, as has commonly been assumed. There remain significant discrepancies that require explanation, however. For example, the effective depth for Earth is 11.3 km rather than 8.5 km and Uranus has an effective depth of 20 km compared to its tropospheric scale height of 27.7 km. We discuss possible explanations for these differences.

  9. 14 CFR 29.815 - Main aisle width.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Main aisle width. 29.815 Section 29.815 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Personnel and Cargo Accommodations §...

  10. “When the going gets tough, who keeps going?” Depletion sensitivity moderates the ego-depletion effect

    PubMed Central

    Salmon, Stefanie J.; Adriaanse, Marieke A.; De Vet, Emely; Fennis, Bob M.; De Ridder, Denise T. D.

    2014-01-01

    Self-control relies on a limited resource that can get depleted, a phenomenon that has been labeled ego-depletion. We argue that individuals may differ in their sensitivity to depleting tasks, and that consequently some people deplete their self-control resource at a faster rate than others. In three studies, we assessed individual differences in depletion sensitivity, and demonstrate that depletion sensitivity moderates ego-depletion effects. The Depletion Sensitivity Scale (DSS) was employed to assess depletion sensitivity. Study 1 employs the DSS to demonstrate that individual differences in sensitivity to ego-depletion exist. Study 2 shows moderate correlations of depletion sensitivity with related self-control concepts, indicating that these scales measure conceptually distinct constructs. Study 3 demonstrates that depletion sensitivity moderates the ego-depletion effect. Specifically, participants who are sensitive to depletion performed worse on a second self-control task, indicating a stronger ego-depletion effect, compared to participants less sensitive to depletion. PMID:25009523

  11. Pixels, Imagers and Related Fabrication Methods

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata (Inventor); Cunningham, Thomas J. (Inventor)

    2014-01-01

    Pixels, imagers and related fabrication methods are described. The described methods result in cross-talk reduction in imagers and related devices by generating depletion regions. The devices can also be used with electronic circuits for imaging applications.

  12. Pixels, Imagers and Related Fabrication Methods

    NASA Technical Reports Server (NTRS)

    Pain, Bedabrata (Inventor); Cunningham, Thomas J. (Inventor)

    2016-01-01

    Pixels, imagers and related fabrication methods are described. The described methods result in cross-talk reduction in imagers and related devices by generating depletion regions. The devices can also be used with electronic circuits for imaging applications.

  13. How Depleted is the MORB mantle?

    NASA Astrophysics Data System (ADS)

    Hofmann, A. W.; Hart, S. R.

    2015-12-01

    Knowledge of the degree of mantle depletion of highly incompatible elements is critically important for assessing Earth's internal heat production and Urey number. Current views of the degree of MORB source depletion are dominated by Salters and Stracke (2004), and Workman and Hart (2005). The first is based on an assessment of average MORB compositions, whereas the second considers trace element data of oceanic peridotites. Both require an independent determination of one absolute concentration, Lu (Salters & Stracke), or Nd (Workman & Hart). Both use parent-daughter ratios Lu/Hf, Sm/Nd, and Rb/Sr calculated from MORB isotopes combined with continental-crust extraction models, as well as "canonical" trace element ratios, to boot-strap the full range of trace element abundances. We show that the single most important factor in determining the ultimate degree of incompatible element depletion in the MORB source lies in the assumptions about the timing of continent extraction, exemplified by continuous extraction versus simple two-stage models. Continued crust extraction generates additional, recent mantle depletion, without affecting the isotopic composition of the residual mantle significantly. Previous emphasis on chemical compositions of MORB and/or peridotites has tended to obscure this. We will explore the effect of different continent extraction models on the degree of U, Th, and K depletion in the MORB source. Given the uncertainties of the two most popular models, the uncertainties of U and Th in DMM are at least ±50%, and this impacts the constraints on the terrestrial Urey ratio. Salters, F.J.M. and Stracke, A., 2004, Geochem. Geophys. Geosyst. 5, Q05004. Workman, R.K. and Hart, S.R., 2005, EPSL 231, 53-72.

  14. Assessment of Gate Width Size on Lifetime-Based Förster Resonance Energy Transfer Parameter Estimation

    PubMed Central

    Chen, Sez-Jade; Sinsuebphon, Nattawut; Intes, Xavier

    2015-01-01

    Förster Resonance Energy Transfer (FRET) enables the observation of interactions at the nanoscale level through the use of fluorescence optical imaging techniques. In FRET, fluorescence lifetime imaging can be used to quantify the fluorescence lifetime changes of the donor molecule, which are associated with proximity between acceptor and donor molecules. Among the FRET parameters derived from fluorescence lifetime imaging, the percentage of donor that interacts with the acceptor (in proximity) can be estimated via model-based fitting. However, estimation of the lifetime parameters can be affected by the acquisition parameters such as the temporal characteristics of the imaging system. Herein, we investigate the effect of various gate widths on the accuracy of estimation of FRET parameters with focus on the near-infrared spectral window. Experiments were performed in silico, in vitro, and in vivo with gate width sizes ranging from 300 ps to 1000 ps in intervals of 100 ps. For all cases, the FRET parameters were retrieved accurately and the imaging acquisition time was decreased three-fold. These results indicate that increasing the gate width up to 1000 ps still allows for accurate quantification of FRET interactions even in the case of short lifetimes such as those encountered with near-infrared FRET pairs. PMID:26557647

  15. FREQUENCY DEPENDENCE OF PULSE WIDTH FOR 150 RADIO NORMAL PULSARS

    SciTech Connect

    Chen, J. L.; Wang, H. G.

    2014-11-01

    The frequency dependence of the pulse width is studied for 150 normal pulsars, mostly selected from the European Pulsar Network, for which the 10% multifrequency pulse widths can be well fit with the Thorsett relationship W {sub 10} = Aν{sup μ} + W {sub 10,} {sub min}. The relative fraction of pulse width change between 0.4 GHz and 4.85 GHz, η = (W {sub 4.85} – W {sub 0.4})/W {sub 0.4}, is calculated in terms of the best-fit relationship for each pulsar. It is found that 81 pulsars (54%) have η < –10% (group A), showing considerable profile narrowing at high frequencies, 40 pulsars (27%) have –10% ≤η ≤ 10% (group B), meaning a marginal change in pulse width, and 29 pulsars (19%) have η > 10% (group C), showing a remarkable profile broadening at high frequencies. The fractions of the group-A and group-C pulsars suggest that the profile narrowing phenomenon at high frequencies is more common than the profile broadening phenomenon, but a large fraction of the group-B and group-C pulsars (a total of 46%) is also revealed. The group-C pulsars, together with a portion of group-B pulsars with slight pulse broadening, can hardly be explained using the conventional radius-to-frequency mapping, which only applies to the profile narrowing phenomenon. Based on a recent version of the fan beam model, a type of broadband emission model, we propose that the diverse frequency dependence of pulse width is a consequence of different types of distribution of emission spectra across the emission region. The geometrical effect predicting a link between the emission beam shrinkage and spectrum steepening is tested but disfavored.

  16. Lithologic controls on valley width and strath terrace formation

    NASA Astrophysics Data System (ADS)

    Schanz, Sarah A.; Montgomery, David R.

    2016-04-01

    Valley width and the degree of bedrock river terrace development vary with lithology in the Willapa and Nehalem river basins, Pacific Northwest, USA. Here, we present field-based evidence for the mechanisms by which lithology controls floodplain width and bedrock terrace formation in erosion-resistant and easily friable lithologies. We mapped valley surfaces in both basins, dated straths using radiocarbon, compared valley width versus drainage area for basalt and sedimentary bedrock valleys, and constructed slope-area plots. In the friable sedimentary bedrock, valleys are 2 to 3 times wider, host flights of strath terraces, and have concavity values near 1; whereas the erosion-resistant basalt bedrock forms narrow valleys with poorly developed, localized, or no bedrock terraces and a channel steepness index half that of the friable bedrock and an average channel concavity of about 0.5. The oldest dated strath terrace on the Willapa River, T2, was active for nearly 10,000 years, from 11,265 to 2862 calibrated years before present (cal YBP), whereas the youngest terrace, T1, is Anthropocene in age and recently abandoned. Incision rates derived from terrace ages average 0.32 mm y- 1 for T2 and 11.47 mm y- 1 for T1. Our results indicate bedrock weathering properties influence valley width through the creation of a dense fracture network in the friable bedrock that results in high rates of lateral erosion of exposed bedrock banks. Conversely, the erosion-resistant bedrock has concavity values more typical of detachment-limited streams, exhibits a sparse fracture network, and displays evidence for infrequent episodic block erosion and plucking. Lithology thereby plays a direct role on the rates of lateral erosion, influencing valley width and the potential for strath terrace planation and preservation.

  17. The role of relative floodplain width in forming anabranching rivers

    NASA Astrophysics Data System (ADS)

    Edmonds, D. A.; Polanco, S. E. M.; Amos, K.

    2015-12-01

    Anabranching rivers (including anastomosing) are a relatively common channel pattern, especially among the world's biggest rivers, and are defined as a system of multiple channels separated by immobile alluvial islands. The origin of anabranching remains poorly understood and is an important topic of research. Previous studies on Australian rivers and a recent empirical compilation show that floodplain width (relative to the size of the channel) might play an important role in the formation of anabranching rivers. To test this idea further we carried out two sets of morphodynamic simulations using Delft3D. In the first set we create a generic channel-floodplain complex with uniform floodplain and channel width, slope, and grain size and allow the system to adjust to passing floodwaves. In successive runs we hold all variables constant, except we increase floodplain width. Results of these simulations show a transition from single channel to braided to anabranching as floodplain width increases. Anabranching arises because as floodplain width increases, alluvial bar growth occurs on the floodplain. The emergence of bars causes flow bifurcation, and subsequent bifurcation instability leads to reduction of channels and the emergence of multiple anabranches. Transition to a stable anabranching pattern is achieved because as anabranches increase their cross-sectional area, Shields stresses on the intervening bars are reduced until they bars stop migrating. To test the idea that alluvial bar growth can be a precursor to anabranching we carried out a second experiment set using boundary conditions from four different field scale anabranching rivers. Results from these simulations show that anabranching can initiate from alluvial bar growth. Compared to field measurements of anabranching rivers our simulations accurately predict number of channels, supporting the idea that relatively wide floodplains might be an important attribute of anabranching rivers.

  18. Utilizing a constant peak width transform for isothermal gas chromatography.

    PubMed

    Nadeau, Jeremy S; Wilson, Ryan B; Fitz, Brian D; Reed, Jason T; Synovec, Robert E

    2011-06-10

    A computational approach to partially address the general elution problem (GEP), and better visualize, isothermal gas chromatograms is reported. The theoretical computational approach is developed and applied experimentally. We report a high speed temporally increasing boxcar summation (TIBS) transform that, when applied to the raw isothermal GC data, converts the chromatographic data from the initial time domain (in which the peak widths in isothermal GC increase as a function of their retention factors, k), to a data point based domain in which all peaks have the same peak width in terms of number of points in the final data vector, which aides in preprocessing and data analysis, while minimizing data storage size. By applying the TIBS transform, the resulting GC chromatogram (initially collected isothermally), appears with an x-axis point scale as if it were instrumentally collected using a suitable temperature program. A high speed GC isothermal separation with a test mixture containing 10 compounds had a run time of ∼25 s. The peak at a retention factor k ∼0.7 had a peak width of ∼55 ms, while the last eluting peak at k ∼89 (i.e., retention time of ∼22 s) had a peak width of ∼2000 ms. Application of the TIBS transform increased the peak height of the last eluting peak 45-fold, and S/N ∼20-fold. All peaks in the transformed test mixture chromatogram had the width of an unretained peak, in terms of number of data points. A simulated chromatogram at unit resolution, studied using the TIBS transform, provided additional insight into the benefits of the algorithm.

  19. Comparator threshold settings and the effective pixel width of the PICASSO detector

    NASA Astrophysics Data System (ADS)

    Lopez, F. C. M.; Rigon, L.; Fardin, L.; Arfelli, F.; Bergamaschi, A.; Dreossi, D.; Longo, M.; Schmitt, B.; Vallazza, E.; Longo, R.

    2014-05-01

    Charge sharing plays an important role in the performance of single-photon counting microstrip detectors, since the comparator threshold defines the effective pixel width. In this contribution, the PICASSO (Phase Imaging for Clinical Application with Silicon detector and Synchrotron radiatiOn) single-photon counting microstrip detector oriented in edge-on configuration has been used to study its spatial resolution as a function of the comparator threshold. The experiment was carried out with monochromatic x-rays at the SYRMEP beamline of the Elettra synchrotron radiation facility in Trieste (Italy). The Edge Spread Function (i.e. the integral of the Line spread Function, LSF) was measured by horizontally translating vertical slits from a bar-pattern test-object in front of the detector, at four different photon energies (19, 20, 22, and 25 keV) and for several different values of the comparator threshold. The effect of charge sharing between strips on the spatial resolution has been quantified by calculating the horizontal Modulation Transfer Function (MTF). Moreover, the composite LSF from neighboring pixels was obtained: this allowed estimating the optimal threshold for each photon energy by selecting the threshold at which the composite LSF would approach unity along the entire width of the pixel. The results show that at thresholds lower than half of the photon energy, charge sharing increases the effective pixel width, causing a drop of the MTF, and it is responsible for the appearance of peaks in the composite LSF. Conversely, at thresholds higher than half of the photon energy, the effective pixel width is reduced and the spatial resolution is increased, but the collection efficiency is compromised, as demonstrated by the presence of valleys in the composite LSF.

  20. Analysis of the width ratio and wear rate of maxillary anterior teeth in the Korean population.

    PubMed

    Oh, Yeon-Ah; Yang, Hong-So; Park, Sang-Won; Lim, Hyun-Pil; Yun, Kwi-Dug; Park, Chan

    2017-04-01

    The purpose of this study was to compare the width ratio of maxillary anterior teeth according to age in the Korean population and to evaluate the maxillary central incisor width-to-length (W/L) ratio, given differences in age and gender. Ninety-three Korean adults were divided into 3 groups (n = 31) by age. Group I was 20 - 39 years old, Group II was 40 - 59 years old, and Group III was over 60 years of age. After taking an impression and a cast model of the maxillary arch, the anterior teeth width ratio and central incisor W/L ratio were calculated from standard digital images of the cast models using a graph paper with a digital single lens reflex (DSLR) camera. The calculated ratios were compared among all groups and central incisor W/L ratio were analyzed according to age and gender. All comparative data were statistically analyzed with one-sample t-tests, one-way ANOVAs with Tukey tests, and independent t-tests. No significant differences in maxillary anterior teeth ratios were found among the age groups. The maxillary central incisor W/L ratios in Group III were the greatest and were significantly higher than those in the other groups. The central incisor W/L ratio of men was higher than that of women in Group II. Maxillary anterior teeth width ratios were similar in all age groups in the Korean population. The maxillary central incisor was observed as worn teeth in the group over 60 years of age, and a significant difference between genders was found in 40 to 50 year olds.

  1. Analysis of the width ratio and wear rate of maxillary anterior teeth in the Korean population

    PubMed Central

    2017-01-01

    PURPOSE The purpose of this study was to compare the width ratio of maxillary anterior teeth according to age in the Korean population and to evaluate the maxillary central incisor width-to-length (W/L) ratio, given differences in age and gender. MATERIALS AND METHODS Ninety-three Korean adults were divided into 3 groups (n = 31) by age. Group I was 20 - 39 years old, Group II was 40 - 59 years old, and Group III was over 60 years of age. After taking an impression and a cast model of the maxillary arch, the anterior teeth width ratio and central incisor W/L ratio were calculated from standard digital images of the cast models using a graph paper with a digital single lens reflex (DSLR) camera. The calculated ratios were compared among all groups and central incisor W/L ratio were analyzed according to age and gender. All comparative data were statistically analyzed with one-sample t-tests, one-way ANOVAs with Tukey tests, and independent t-tests. RESULTS No significant differences in maxillary anterior teeth ratios were found among the age groups. The maxillary central incisor W/L ratios in Group III were the greatest and were significantly higher than those in the other groups. The central incisor W/L ratio of men was higher than that of women in Group II. CONCLUSION Maxillary anterior teeth width ratios were similar in all age groups in the Korean population. The maxillary central incisor was observed as worn teeth in the group over 60 years of age, and a significant difference between genders was found in 40 to 50 year olds. PMID:28435617

  2. Vitamin D Intoxication, with Hypernatraemia, Potassium and Water Depletion, and Mental Depression

    PubMed Central

    Anderson, D. C.; Cooper, A. F.; Naylor, G. J.

    1968-01-01

    Two elderly patients suffering from manic-depressive psychosis/depressive reaction had concurrently hypercalcaemia from vitamin D intoxication. They developed hypernatraemia with severe potassium and water depletion. Hypercalcaemia was pronounced, but both patients recovered quickly and their depressive symptoms resolved following water and potassium repletion and corticosteroid therapy. ImagesFig. 1Fig. 2 PMID:5723727

  3. Narrowed beam width in newer ultrasound machines shortens measurements in the lateral direction: fetal measurement charts may be obsolete.

    PubMed

    Økland, I; Bjåstad, T G; Johansen, T F; Gjessing, H K; Grøttum, P; Eik-Nes, S H

    2011-07-01

    Fetal ultrasound measurements are made in axial, lateral and oblique directions. Lateral resolution is influenced by the beam width of the ultrasound system. To improve lateral resolution and image quality, the beam width has been made narrower; consequently, measurements in the lateral direction are affected and apparently made shorter, approaching the true length. The aims of this study were to explore our database to reveal time-dependent shortening of ultrasound measurements made in the lateral direction, and to assess the extent of beam-width changes by comparing beam-width measurements made on old and new ultrasound machines. A total of 41,941 femur length measurements, collected during the time-period 1987-2005, were analyzed, with time as a covariate. Using three ultrasound machines from the 1990s and three newer machines from 2007, we performed 25 series of blinded beam-width measurements on a tissue-mimicking phantom, measuring at depths of 3-8 cm with a 5-MHz transducer. Regression analysis showed time to be a significant covariate. At the same gestational age, femur length measurement was 1.15 (95% CI, 1.08-1.23) mm shorter in the time-period 1999-2005 than in the time-period 1987-1992. Overall, the beam width was 1.08 (95% CI, 0.50-1.65) mm narrower with the new machines than with the old machines. Technical improvements in modern ultrasound machines that have reduced the beam width affect fetal measurements in the lateral direction. This has clinical implications and new measurement charts are needed. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.

  4. MESSENGER observations of the plasma depletion layer in Mercury's magnetosphere

    NASA Astrophysics Data System (ADS)

    Gershman, D. J.; Slavin, J. A.; Raines, J. M.; Zurbuchen, T.; Anderson, B. J.; Korth, H.; Baker, D. N.; Solomon, S. C.

    2012-12-01

    Measurements made with the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft's Fast Imaging Plasma Spectrometer (FIPS) and Magnetometer (MAG) are used to determine the properties of the plasma depletion layer (PDL) that is found just exterior to Mercury's dayside magnetopause. PDLs form when interplanetary magnetic flux tubes drape around and are compressed against an obstacle to the solar wind. Such obstacles include not only planetary magnetic fields such as that of Mercury, but also the ionospheres of comets and planets without internal fields such as Venus. It is this compression of the draped flux tubes against the magnetopause that causes the solar wind plasma to flow away from the subsolar region and deplete the flux tubes of plasma. Observations of the PDL at Earth have shown that such properties of this layer as its thickness and its reduction in density are strong functions of the solar wind Alfvénic Mach number and the orientation of the interplanetary magnetic field (IMF). The MESSENGER measurements show that a PDL is indeed present at Mercury and confirm the theoretical prediction that the thickness and degree of depletion is enhanced for the very low Alfvénic Mach numbers in the inner Solar System, on average a factor of ~2 smaller than those at Earth. For several transits of the spacecraft through the magnetosheath near local noon, each lasting only a few minutes, the plasma and magnetic field of the PDL have been sampled, capturing a snapshot of the shocked solar wind near the stagnation point. The relative density reduction and thickness of the PDL are examined for each magnetospheric pass and placed into context with the set of available solar wind forcing conditions and IMF orientations in order to study the formation of these layers at Mercury with and without the presence of dayside magnetic reconnection.

  5. Generation of large-scale equatorial F-region plasma depletions during geomagnetic storms: A review

    NASA Astrophysics Data System (ADS)

    Sahai, Y.; Fagundes, P.; Bittencourt, J.; Pimenta, A.

    All-sky imaging observations of the F-region OI 630 nm nightglow emission allow us to visualize large - scale equatorial plasma depletions, generally known as transequatorial plasma bubbles. These quasi north south direction aligned- ionospheric plasma depletions are o tical signatures of strong range type equatorialp spread-F. An extensive data base of the OI 630 nm emission all-sky imaging- observations has been obtained at Cachoeira Paulista (22.7o S, 45.0 o W; dip latitude ~16o S), Brazil, between the years 1987 and 2000. An analysis of these observations revealed that normally large-scale ionospheric plasma depletions do not occur during the months of May to August (southern winter) in the Brazilian sector. However, large-scale ionospheric plasma depletions during thes e months have been observed on several occasions in association with geomagnetic storms. In this paper, a detailed analysis of the events when large - scale ionospheric plasma depletions were initiated and evolved during magnetic disturbances will be present ed and discussed.

  6. Calsequestrin depolymerizes when calcium is depleted in the sarcoplasmic reticulum of working muscle

    PubMed Central

    Manno, Carlo; Figueroa, Lourdes C.; Gillespie, Dirk; Fitts, Robert; Kang, ChulHee; Franzini-Armstrong, Clara; Rios, Eduardo

    2017-01-01

    Calsequestrin, the only known protein with cyclical storage and supply of calcium as main role, is proposed to have other functions, which remain unproven. Voluntary movement and the heart beat require this calcium flow to be massive and fast. How does calsequestrin do it? To bind large amounts of calcium in vitro, calsequestrin must polymerize and then depolymerize to release it. Does this rule apply inside the sarcoplasmic reticulum (SR) of a working cell? We answered using fluorescently tagged calsequestrin expressed in muscles of mice. By FRAP and imaging we monitored mobility of calsequestrin as [Ca2+] in the SR--measured with a calsequestrin-fused biosensor--was lowered. We found that calsequestrin is polymerized within the SR at rest and that it depolymerized as [Ca2+] went down: fully when calcium depletion was maximal (a condition achieved with an SR calcium channel opening drug) and partially when depletion was limited (a condition imposed by fatiguing stimulation, long-lasting depolarization, or low drug concentrations). With fluorescence and electron microscopic imaging we demonstrated massive movements of calsequestrin accompanied by drastic morphological SR changes in fully depleted cells. When cells were partially depleted no remodeling was found. The present results support the proposed role of calsequestrin in termination of calcium release by conformationally inducing closure of SR channels. A channel closing switch operated by calsequestrin depolymerization will limit depletion, thereby preventing full disassembly of the polymeric calsequestrin network and catastrophic structural changes in the SR. PMID:28069951

  7. A worldwide view of groundwater depletion

    NASA Astrophysics Data System (ADS)

    van Beek, L. P.; Wada, Y.; van Kempen, C.; Reckman, J. W.; Vasak, S.; Bierkens, M. F.

    2010-12-01

    During the last decades, global water demand has increased two-fold due to increasing population, expanding irrigated area and economic development. Globally such demand can be met by surface water availability (i.e., water in rivers, lakes and reservoirs) but regional variations are large and the absence of sufficient rainfall and run-off increasingly encourages the use of groundwater resources, particularly in the (semi-)arid regions of the world. Excessive abstraction for irrigation frequently leads to overexploitation, i.e. if groundwater abstraction exceeds the natural groundwater recharge over extensive areas and prolonged times, persistent groundwater depletion may occur. Observations and various regional studies have revealed that groundwater depletion is a substantial issue in regions such as Northwest India, Northeast Pakistan, Central USA, Northeast China and Iran. Here we provide a global overview of groundwater depletion from the year 1960 to 2000 at a spatial resolution of 0.5 degree by assessing groundwater recharge with the global hydrological model PCR-GLOBWB and subtracting estimates of groundwater abstraction obtained from IGRAC-GGIS database. PCR-GLOBWB was forced by the CRU climate dataset downscaled to daily time steps using ERA40 re-analysis data. PCR-GLOBWB simulates daily global groundwater recharge (0.5 degree) while considering sub-grid variability of each grid cell (e.g., short and tall vegetation, different soil types, fraction of saturated soil). Country statistics of groundwater abstraction were downscaled to 0.5 degree by using water demand (i.e., agriculture, industry and domestic) as a proxy. To limit problems related to increased capture of discharge and increased recharge due to groundwater pumping, we restricted our analysis to sub-humid to arid areas. The uncertainty in the resulting estimates was assessed by a Monte Carlo analysis of 100 realizations of groundwater recharge and 100 realizations of groundwater abstraction

  8. [Imaging].

    PubMed

    Chevrot, A; Drapé, J L; Godefroy, D; Dupont, A M; Pessis, E; Sarazin, L; Minoui, A

    1997-01-01

    The panoply of imaging techniques useful in podology is essentially limited to X-rays. Standard "standing" and "lying" X-rays furnish most of the required information. Arthrography is sometimes performed, in particular for trauma or tumour of the ankle. CT scan and MRI make a decisive contribution in difficult cases, notably in fractures and in small fractures without displacement. The two latter techniques are useful in tendon, ligament and muscular disorders, where echography is also informative. Rigorous analysis of radiographies and a good knowledge of foot disorders make these imaging techniques efficacious.

  9. A method for determining the drift velocity of plasma depletions in the equatorial ionosphere using far-ultraviolet spacecraft observations

    NASA Astrophysics Data System (ADS)

    Park, S. H.; England, S. L.; Immel, T. J.; Frey, H. U.; Mende, S. B.

    2007-11-01

    The Far-Ultraviolet Imager (IMAGE-FUV) on board the NASA IMAGE satellite has been used to observe plasma depletions in the nightside equatorial ionosphere. Observations from periods around spacecraft apogee, during which equatorial regions are visible for several hours, have allowed the velocity of these plasma depletions to be determined. A new method for determining the velocity of these depletions using an image analysis technique, Tracking Of Airglow Depletions (TOAD), has been developed. TOAD allows the objective identification and tracking of depletions. The automation of this process has also allowed for the tracking of a greater number of depletions than previously achieved without requiring any human input, which shows that TOAD is suitable for use with large data sets and for future routine monitoring of the ionosphere from space. Furthermore, this automation allows the drift velocities of each bubble to be determined as a function of magnetic latitude, which will give us the capability of retrieving geophysically important parameters such as the electric field, which are believed to vary rapidly with magnetic latitude.

  10. Iron isotope composition of depleted MORB

    NASA Astrophysics Data System (ADS)

    Labidi, J.; Sio, C. K. I.; Shahar, A.

    2015-12-01

    In terrestrial basalts, iron isotope ratios are observed to weakly fractionate as a function of olivine and pyroxene crystallization. However, a ~0.1‰ difference between chondrites and MORB had been reported (Dauphas et al. 2009, Teng et al. 2013 and ref. therein). This observation could illustrate an isotope fractionation occurring during partial melting, as a function of the Fe valence in melt versus crystals. Here, we present high-precision Fe isotopic data measured by MC-ICP-MS on well-characterized samples from the Pacific-Antarctic Ridge (PAR, n=9) and from the Garrett Transform Fault (n=8). These samples allow exploring the Fe isotope fractionation between melt and magnetite, and the role of partial melting on Fe isotope fractionation. Our average δ56Fe value is +0.095±0.013‰ (95% confidence, n=17), indistinguishable from a previous estimate of +0.105±0.006‰ (95% confidence, n=43, see ref. 2). Our δ56Fe values correlate weakly with MgO contents, and correlate positively with K/Ti ratios. PAC1 DR10 shows the largest Ti and Fe depletion after titanomagnetite fractionation, with a δ56Fe value of +0.076±0.036‰. This is ~0.05‰ below other samples at a given MgO. This may illustrate a significant Fe isotope fractionation between the melt and titanomagnetite, in agreement with experimental determination (Shahar et al. 2008). GN09-02, the most incompatible-element depleted sample, has a δ56Fe value of 0.037±0.020‰. This is the lowest high-precision δ56Fe value recorded for a MORB worldwide. This basalt displays an incompatible-element depletion consistent with re-melting beneath the transform fault of mantle source that was depleted during a first melting event, beneath the ridge axis (Wendt et al. 1999). The Fe isotope observation could indicate that its mantle source underwent 56Fe depletion after a first melting event. It could alternatively indicate a lower Fe isotope fractionation during re-melting, if the source was depleted of its Fe3

  11. Evolution of valleys width : A Mars-Earth comparison

    NASA Astrophysics Data System (ADS)

    Pochat, Stéphane; Loget, Nicolas

    2013-04-01

    The analyses of the valleys on Mars are used to reconstruct the climate on Early Mars (~ 3.5 Gy). Thus, many studies indicate a strong analogy between earth and mars networks (dendritic organization, drainage density Strahler ordering) which is compatible with a widespread rain (today Mars is arid, cold and the water can only be vapor/snow). But, many features are too different with the Earth classic valleys networks to conclude definitively on the Early climate of Mars. Here, we study the evolution of the width of valleys with drainage area. This method lies on the relationship between the evolution of the channel width (W) versus the discharge of the river or the upstream drainage area (A) such as Wc= bA0.5 (e.g Leopold and Maddock, 1953; Montgomery and Gran, 2001). On Mars, one of the difficulties is to plot the width of the channel but recent studies on Mars and on Earth indicate that the valley bottom width Wv strictly follows the same evolution than the channel width (e.g. Mattheus and Rodriguez 2011, Phillips, 2011). Thereby, we analyzed 366 basins on Earth from 4.10-02 to 6.1006 km2 and 355 basins on Mars from 7.10-02 to 2.8.1006 km2. For Earth Wv= bA0.46 with 0.005< b< 0.047. For Mars Wv= bA0.27 with 0.046< b< 0.19. Martian valleys are ten times wider for small tributaries (< 100 km2) but ten times smaller for large tributaries >100.000 km2). Our observations are compatible with an inefficient system with strong supply of water, on small systems, which is less and less transmitted at the outlet, on large systems. The origins of this inefficiency will be discussed. Leopold, L. B. and T. Maddock (1953). The hydraulic geometry of stream channels and some physiographic implications. United States Geological Survey Professional Paper. Montgomery, D. R. and K. B. Gran (2001). "Downstream Variations in the Width of Bedrock Channels." Water Resour. Res. Jonathan D. Phillips (2011): Drainage area and incised valley fills in Texas rivers: A potential explanation

  12. Properties of Ca2+ sparks revealed by four-dimensional confocal imaging of cardiac muscle

    PubMed Central

    Shkryl, Vyacheslav M.; Blatter, Lothar A.

    2012-01-01

    Parameters (amplitude, width, kinetics) of Ca2+ sparks imaged confocally are affected by errors when the spark source is not in focus. To identify sparks that were in focus, we used fast scanning (LSM 5 LIVE; Carl Zeiss) combined with fast piezoelectric focusing to acquire x–y images in three planes at 1-µm separation (x-y-z-t mode). In 3,000 x–y scans in each of 34 membrane-permeabilized cat atrial cardiomyocytes, 6,906 sparks were detected. 767 sparks were in focus. They had greater amplitude, but their spatial width and rise time were similar compared with all sparks recorded. Their distribution of amplitudes had a mode at ΔF/F0 = 0.7. The Ca2+ release current underlying in-focus sparks was 11 pA, requiring 20 to 30 open channels, a number at the high end of earlier estimates. Spark frequency was greater than in earlier imaging studies of permeabilized ventricular cells, suggesting a greater susceptibility to excitation, which could have functional relevance for atrial cells. Ca2+ release flux peaked earlier than the time of peak fluorescence and then decayed, consistent with significant sarcoplasmic reticulum (SR) depletion. The evolution of fluorescence and release flux were strikingly similar for in-focus sparks of different rise time (T). Spark termination involves both depletion of Ca2+ in the SR and channel closure, which may be synchronized by depletion. The observation of similar flux in sparks of different T requires either that channel closure and other termination processes be independent of the determinants of flux (including [Ca2+]SR) or that different channel clusters respond to [Ca2+]SR with different sensitivity. PMID:22330954

  13. Images.

    ERIC Educational Resources Information Center

    Barr, Catherine, Ed.

    1997-01-01

    The theme of this month's issue is "Images"--from early paintings and statuary to computer-generated design. Resources on the theme include Web sites, CD-ROMs and software, videos, books, and others. A page of reproducible activities is also provided. Features include photojournalism, inspirational Web sites, art history, pop art, and myths. (AEF)

  14. The rotation-lithium depletion correlation in the β Pictoris association and the LDB age determination

    NASA Astrophysics Data System (ADS)

    Messina, S.; Lanzafame, A. C.; Feiden, G. A.; Millward, M.; Desidera, S.; Buccino, A.; Curtis, I.; Jofré, E.; Kehusmaa, P.; Medhi, B. J.; Monard, B.; Petrucci, R.

    2016-11-01

    Context. Evidence exists in the 125-Myr Pleiades cluster, and more recently in the 5-Myr NGC 2264 cluster, to show that rotation plays a key role in lithium (Li) depletion processes among low-mass stars. Fast rotators appear to be less Li-depleted than equal-mass slow rotators. Aims: We intend to explore the existence of a Li depletion-rotation connection among the β Pictoris members at an age of about 24 Myr, and to use this correlation either to confirm or to improve age estimates based on the lithium depletion boundary (LDB) modeling. Methods: We photometrically monitored all the known members of the β Pictoris association with at least one lithium equivalent width (Li EW) measurement from the literature. Results: We measured the rotation periods of 30 members for the first time and retrieved the rotation periods for another 36 members from the literature, building a catalogue of 66 members with a measured rotation period and Li EW. Conclusions: We find that in the 0.3 < M < 0.8M⊙ range, there is a strong correlation between rotation and Li EW. For higher mass stars, no significant correlation is found. For very low-mass stars in the Li depletion onset, at about 0.1 M⊙, there are too few data to infer a significant correlation. The observed Li EWs are compared with those predicted by the Dartmouth stellar evolutionary models that incorporate the effects of magnetic fields. After decorrelating the Li EW from the rotation period, we find that the hot side of the LDB is well fitted by Li EW values that correspond to an age of 25 ± 3 Myr, which is in good agreement with independent estimates from the literature.

  15. Reference Values for the Scalene Interval Width During Varying Degrees of Glenohumeral Abduction Using Ultrasonography.

    PubMed

    Mattox, Ross; Battaglia, Patrick J; Welk, Aaron B; Maeda, Yumi; Haun, Daniel W; Kettner, Norman W

    The aim of this study was to establish reference values for the width of the interval between the anterior and middle scalene muscles using ultrasonography during varying degrees of glenohumeral joint (GH) abduction. Reliability and body mass index (BMI) data were also assessed. Interscalene triangles of asymptomatic participants were scanned bilaterally in the transverse plane. Images were obtained at 0°, 90°, and 150° of GH abduction with the participant seated. Width measurements were taken between the anterior and middle scalene muscle borders by bisecting the C6 nerve root as it passed superficial to the posterior tubercle of the C7 transverse process. Intra- and interexaminer reliability and BMI correlation were studied. Statistical significance was defined as P ≤ .05. Images of 42 scalene intervals were included from 21 participants (11 female). Mean participant age was 25.3 ± 3.9 years; mean BMI was 25.4 ± 2.7 kg/m(2). Scalene interval measurements at 0°, 90°, and 150° of GH abduction were 4.5 ± 0.5 mm, 4.6 ± 0.5 mm, and 4.4 ± 0.7 mm, respectively, without a significant difference (P = .07). Intraexaminer reliability was excellent (0°: intraclass correlation coefficient [ICC] = 0.82; 90°: ICC = 0.89; 150°: ICC = 0.90). Interexaminer reliability was good to excellent (0°: ICC = 0.59; 90°: ICC = 0.85; 150°: ICC = 0.89). Body mass index was positively correlated only at 0° of GH abduction. This study establishes previously unreported reference ultrasonography values for the width of the scalene interval. Intraexaminer reliability was excellent at all glenohumeral positions, and interexaminer reliability was determined to be good to excellent. Body mass index was positively correlated only at 0° of GH abduction. Copyright © 2016. Published by Elsevier Inc.

  16. Copenhagen delegates advance phaseout of ozone depleters

    SciTech Connect

    Kirschner, E.

    1992-12-09

    As expected, delegates at the United Nations Ozone Layer Conference in Copenhagen sped up ozone depleter phaseouts from the 1987 Montreal Protocol and the 1990 London amendments. The changes bring the worldwide production phaseout of chlorofluorocarbons (CFCs) and other ozone depleters in developed countries in line with U.S. and European plans announced earlier this year. Adjustments to the protocol, which are binding on the signatories, change the phaseout for CFC, carbon tetrachloride, and methyl chloroform production and consumption to January 1, 1996 from 2000. The 75% reduction of 1986 levels from CFCs by January 1, 1994 is a compromise between European pressure for an 85% cut and the US goal of 70%. Halon production is to end January 1, 1994, as anticipated. Developing countries continue to have a 10-year grace period. Friends of the Earth ozone campaign director Liz Cook counters that the phaseout dates were scheduled with concern for the chemical industry, not for the ozone layer.

  17. Replacements For Ozone-Depleting Foaming Agents

    NASA Technical Reports Server (NTRS)

    Blevins, Elana; Sharpe, Jon B.

    1995-01-01

    Fluorinated ethers used in place of chlorofluorocarbons and hydrochlorofluorocarbons. Replacement necessary because CFC's and HCFC's found to contribute to depletion of ozone from upper atmosphere, and manufacture and use of them by law phased out in near future. Two fluorinated ethers do not have ozone-depletion potential and used in existing foam-producing equipment, designed to handle liquid blowing agents soluble in chemical ingredients that mixed to make foam. Any polyurethane-based foams and several cellular plastics blown with these fluorinated ethers used in processes as diverse as small batch pours, large sprays, or double-band lamination to make insulation for private homes, commercial buildings, shipping containers, and storage tanks. Fluorinated ethers proved useful as replacements for CFC refrigerants and solvents.

  18. Replacements For Ozone-Depleting Foaming Agents

    NASA Technical Reports Server (NTRS)

    Blevins, Elana; Sharpe, Jon B.

    1995-01-01

    Fluorinated ethers used in place of chlorofluorocarbons and hydrochlorofluorocarbons. Replacement necessary because CFC's and HCFC's found to contribute to depletion of ozone from upper atmosphere, and manufacture and use of them by law phased out in near future. Two fluorinated ethers do not have ozone-depletion potential and used in existing foam-producing equipment, designed to handle liquid blowing agents soluble in chemical ingredients that mixed to make foam. Any polyurethane-based foams and several cellular plastics blown with these fluorinated ethers used in processes as diverse as small batch pours, large sprays, or double-band lamination to make insulation for private homes, commercial buildings, shipping containers, and storage tanks. Fluorinated ethers proved useful as replacements for CFC refrigerants and solvents.

  19. Ozone depletion in tropospheric volcanic plumes

    NASA Astrophysics Data System (ADS)

    Vance, Alan; McGonigle, Andrew J. S.; Aiuppa, Alessandro; Stith, Jeffrey L.; Turnbull, Kate; von Glasow, Roland

    2010-11-01

    We measured ozone (O3) concentrations in the atmospheric plumes of the volcanoes St. Augustine (1976), Mt. Etna (2004, 2009) and Eyjafjallajökull (2010) and found O3 to be strongly depleted compared to the background at each volcano. At Mt. Etna O3 was depleted within tens of seconds from the crater, the age of the St. Augustine plumes was on the order of hours, whereas the O3 destruction in the plume of Eyjafjallajökull was maintained in 1-9 day old plumes. The most likely cause for this O3 destruction are catalytic bromine reactions as suggested by a model that manages to reproduce the very early destruction of O3 but also shows that O3 destruction is ongoing for several days. Given the observed rapid and sustained destruction of O3, heterogeneous loss of O3 on ash is unlikely to be important.

  20. Endoplasmic-Reticulum Calcium Depletion and Disease

    PubMed Central

    Mekahli, Djalila; Bultynck, Geert; Parys, Jan B.; De Smedt, Humbert; Missiaen, Ludwig

    2011-01-01

    The endoplasmic reticulum (ER) as an intracellular Ca2+ store not only sets up cytosolic Ca2+ signals, but, among other functions, also assembles and folds newly synthesized proteins. Alterations in ER homeostasis, including severe Ca2+ depletion, are an upstream event in the pathophysiology of many diseases. On the one hand, insufficient release of activator Ca2+ may no longer sustain essential cell functions. On the other hand, loss of luminal Ca2+ causes ER stress and activates an unfolded protein response, which, depending on the duration and severity of the stress, can reestablish normal ER function or lead to cell death. We will review these various diseases by mainly focusing on the mechanisms that cause ER Ca2+ depletion. PMID:21441595

  1. Assessment of Preferred Depleted Uranium Disposal Forms

    SciTech Connect

    Croff, A.G.; Hightower, J.R.; Lee, D.W.; Michaels, G.E.; Ranek, N.L.; Trabalka, J.R.

    2000-06-01

    The Department of Energy (DOE) is in the process of converting about 700,000 metric tons (MT) of depleted uranium hexafluoride (DUF6) containing 475,000 MT of depleted uranium (DU) to a stable form more suitable for long-term storage or disposal. Potential conversion forms include the tetrafluoride (DUF4), oxide (DUO2 or DU3O8), or metal. If worthwhile beneficial uses cannot be found for the DU product form, it will be sent to an appropriate site for disposal. The DU products are considered to be low-level waste (LLW) under both DOE orders and Nuclear Regulatory Commission (NRC) regulations. The objective of this study was to assess the acceptability of the potential DU conversion products at potential LLW disposal sites to provide a basis for DOE decisions on the preferred DU product form and a path forward that will ensure reliable and efficient disposal.

  2. Depleted uranium plasma reduction system study

    SciTech Connect

    Rekemeyer, P.; Feizollahi, F.; Quapp, W.J.; Brown, B.W.

    1994-12-01

    A system life-cycle cost study was conducted of a preliminary design concept for a plasma reduction process for converting depleted uranium to uranium metal and anhydrous HF. The plasma-based process is expected to offer significant economic and environmental advantages over present technology. Depleted Uranium is currently stored in the form of solid UF{sub 6}, of which approximately 575,000 metric tons is stored at three locations in the U.S. The proposed system is preconceptual in nature, but includes all necessary processing equipment and facilities to perform the process. The study has identified total processing cost of approximately $3.00/kg of UF{sub 6} processed. Based on the results of this study, the development of a laboratory-scale system (1 kg/h throughput of UF6) is warranted. Further scaling of the process to pilot scale will be determined after laboratory testing is complete.

  3. Lattice QCD calculation of the {rho} meson decay width

    SciTech Connect

    Aoki, S.; Fukugita, M.; Ishikawa, K-I.; Okawa, M.; Ishizuka, N.; Kuramashi, Y.; Ukawa, A.; Yoshie, T.; Kanaya, K.; Namekawa, Y.; Sasaki, K.

    2007-11-01

    We present a lattice QCD calculation of the {rho} meson decay width via the P-wave scattering phase shift for the I=1 two-pion system. Our calculation uses full QCD gauge configurations for N{sub f}=2 flavors generated using a renormalization group improved gauge action and an improved Wilson fermion action on a 12{sup 3}x24 lattice at m{sub {pi}}/m{sub {rho}}=0.41 and the lattice spacing 1/a=0.92 GeV. The phase shift calculated with the use of the finite size formula for the two-pion system in the moving frame shows a behavior consistent with the existence of a resonance at a mass close to the vector meson mass obtained in spectroscopy. The decay width estimated from the phase shift is consistent with the experiment, when the quark mass is scaled to the realistic value.

  4. Magnetohydrodynamic disc winds and line width distributions - II

    NASA Astrophysics Data System (ADS)

    Chajet, L. S.; Hall, P. B.

    2017-02-01

    We study AGN emission line profiles combining an improved version of the accretion disc-wind model of Murray & Chiang with the magnetohydrodynamic (MHD) model of Emmering et al. Here, we extend our previous work to consider central objects with different masses and/or luminosities. We have compared the dispersions in our model C IV line-width distributions to observational upper limit on that dispersion, considering both smooth and clumpy torus models. Following Fine et al., we transform that scatter in the profile line-widths into a constraint on the torus geometry and show how the half-opening angle of the obscuring structure depends on the mass of the central object and the accretion rate. We find that the results depend only mildly on the dimensionless angular momentum, one of the two integrals of motion that characterize the dynamics of the self-similar ideal MHD outflows.

  5. Frequency width of open channels in multiple scattering media.

    PubMed

    Bosch, Jeroen; Goorden, Sebastianus A; Mosk, Allard P

    2016-11-14

    We report optical measurements of the spectral width of open transmission channels in a three-dimensional diffusive medium. The light transmission through a sample is enhanced by efficiently coupling to open transmission channels using repeated digital optical phase conjugation. The spectral properties are investigated by enhancing the transmission, fixing the incident wavefront and scanning the wavelength of the laser. We measure the transmitted field to extract the field correlation function and the enhancement of the total transmission. We find that optimizing the total transmission leads to a significant increase in the frequency width of the field correlation function. Additionally we find that the enhanced transmission persists over an even larger frequency bandwidth. This result shows open channels in the diffusive regime are spectrally much wider than previous measurements in the localized regime suggest.

  6. Determination of the width of the top quark.

    PubMed

    Abazov, V M; Abbott, B; Abolins, M; Acharya, B S; Adams, M; Adams, T; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Ancu, L S; Aoki, M; Arnoud, Y; Arov, M; Askew, A; Åsman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bazterra, V; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Bolton, T A; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brandt, O; Brock, R; Brooijmans, G; Bross, A; Brown, D; Brown, J; Bu, X B; Buchholz, D; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calpas, B; Camacho-Pérez, E; Carrasco-Lizarraga, M A; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chen, G; Chevalier-Théry, S; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Christoudias, T; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Croc, A; Cutts, D; Ćwiok, M; Das, A; Davies, G; De, K; de Jong, S J; De la Cruz-Burelo, E; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; DeVaughan, K; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Eno, S; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Gadfort, T; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geist, W; Geng, W; Gerbaudo, D; Gerber, C E; Gershtein, Y; Ginther, G; Golovanov, G; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guo, F; Guo, J; Gutierrez, G; Gutierrez, P; Haas, A; Hagopian, S; Haley, J; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; Heredia-De la Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hossain, S; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jain, S; Jamin, D; Jesik, R; Johns, K; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Joshi, J; Juste, A; Kaadze, K; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kirby, M H; Kohli, J M; Kozelov, A V; Kraus, J; Kumar, A; Kupco, A; Kurča, T; Kuzmin, V A; Kvita, J; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Love, P; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Madar, R; Magaña-Villalba, R; Malik, S; Malyshev, V L; Maravin, Y; Martínez-Ortega, J; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Mondal, N K; Muanza, G S; Mulhearn, M; Nagy, E; Naimuddin, M; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Novaes, S F; Nunnemann, T; Obrant, G; Orduna, J; Osman, N; Osta, J; Otero y Garzón, G J; Owen, M; Padilla, M; Pangilinan, M; Parashar, N; Parihar, V; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Petrillo, G; Pétroff, P; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Pol, M-E; Polozov, P; Popov, A V; Prewitt, M; Price, D; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Ranjan, K; Ratoff, P N; Razumov, I; Renkel, P; Rich, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Santos, A S; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shchukin, A A; Shivpuri, R K; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, K J; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Sopczak, A; Sosebee, M; Soustruznik, K; Spurlock, B; Stark, J; Stolin, V; Stoyanova, D A; Strauss, E; Strauss, M; Strom, D; Stutte, L; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Titov, M; Tokmenin, V V; Tsybychev, D; Tuchming, B; Tully, C; Tuts, P M; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vint, P; Vokac, P; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, M; Welty-Rieger, L; Wetstein, M; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wimpenny, S J; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Yoo, H D; Youn, S W; Yu, J; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L

    2011-01-14

    We extract the total width of the top quark, Γ(t), from the partial decay width Γ(t → Wb) measured using the t-channel cross section for single top-quark production and from the branching fraction B(t → Wb) measured in tt events using up to 2.3  fb(-1) of integrated luminosity collected by the D0 Collaboration at the Tevatron pp Collider. The result is Γ(t) = 1.99(-0.55)(+0.69)  GeV, which translates to a top-quark lifetime of τ(t) = (3.3(-0.9)(+1.3)) × 10(-25)   s. Assuming a high mass fourth generation b' quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |V(tb')| < 0.63 at 95% C.L.

  7. Reduction of track width in perpendicular magnetic recording

    NASA Astrophysics Data System (ADS)

    Xia, W.; Yamada, T.; Aoi, H.; Muraoka, H.; Nakamura, Y.

    2005-02-01

    In order to three dimensionally analyze perpendicular magnetic recording mechanisms, we have developed a program in which the magnetization of magnetic particles is introduced into calculations of magnetization distributions in a recording layer, based on the commercial software JMAG-Studio. Because this program was based on a FEM calculation, the head and media interactions and demagnetization during the recording process can be accurately modeled. Using this program, methods to reduce the recorded track width in perpendicular magnetic recording were investigated. Decreasing the magnetic spacing, the use of a side-shielded head structure and using media with weak exchange coupling are effective ways to reduce the track width in a single pole head and double-layer perpendicular media recording system.

  8. Packing defects and the width of biopolymer bundles.

    PubMed

    Gov, Nir S

    2008-07-01

    The formation of bundles composed of actin filaments and cross-linking proteins is an essential process in the maintenance of the cells' cytoskeleton. It has also been recreated by in-vitro experiments, where actin networks are routinely produced to mimic and study the cellular structures. It has been observed that these bundles seem to have a well-defined width distribution, which has not been adequately described theoretically. We propose here that packing defects of the filaments, quenched and random, contribute an effective repulsion that counters the cross-linking adhesion energy and leads to a well-defined bundle width. This is a two-dimensional strain-field version of the classic Rayleigh instability of charged droplets.

  9. A Direct Measurement of the $W$ Decay Width

    SciTech Connect

    Vine, Troy

    2008-08-01

    A direct measurement of the W boson total decay width is presented in proton-antiproton collisions at √s = 1.96 TeV using data collected by the CDF II detector. The measurement is made by fitting a simulated signal to the tail of the transverse mass distribution in the electron and muon decay channels. An integrated luminosity of 350 pb-1 is used, collected between February 2002 and August 2004. Combining the results from the separate decay channels gives the decay width as 2.038 ± 0.072 GeV in agreement with the theoretical prediction of 2.093 ± 0.002 GeV. A system is presented for the management of detector calibrations using a relational database schema. A description of the implementation and monitoring of a procedure to provide general users with a simple interface to the complete set of calibrations is also given.

  10. The ultimate disposition of depleted uranium

    SciTech Connect

    Not Available

    1990-12-01

    Significant amounts of the depleted uranium (DU) created by past uranium enrichment activities have been sold, disposed of commercially, or utilized by defense programs. In recent years, however, the demand for DU has become quite small compared to quantities available, and within the US Department of Energy (DOE) there is concern for any risks and/or cost liabilities that might be associated with the ever-growing inventory of this material. As a result, Martin Marietta Energy Systems, Inc. (Energy Systems), was asked to review options and to develop a comprehensive plan for inventory management and the ultimate disposition of DU accumulated at the gaseous diffusion plants (GDPs). An Energy Systems task team, under the chairmanship of T. R. Lemons, was formed in late 1989 to provide advice and guidance for this task. This report reviews options and recommends actions and objectives in the management of working inventories of partially depleted feed (PDF) materials and for the ultimate disposition of fully depleted uranium (FDU). Actions that should be considered are as follows. (1) Inspect UF{sub 6} cylinders on a semiannual basis. (2) Upgrade cylinder maintenance and storage yards. (3) Convert FDU to U{sub 3}O{sub 8} for long-term storage or disposal. This will include provisions for partial recovery of costs to offset those associated with DU inventory management and the ultimate disposal of FDU. Another recommendation is to drop the term tails'' in favor of depleted uranium'' or DU'' because the tails'' label implies that it is waste.'' 13 refs.

  11. Health Effects of Embedded Depleted Uranium Fragments.

    DTIC Science & Technology

    2011-03-24

    Canada Feasibility Studies of a Method for Determining Depleted Uranium Deposited in Human Limbs .................. 39 Gary S . Kramer and Erin S . Niven...International Defense Review, 27:39-46 4 Introduction to the Problem 11. Filszar RL, Wilsey EF, Bloore EW (1989) Ra- and bulk storage conditions. Richland, WA...MD, Report BRL-TR- 3068 19. Limits for intakes of radionuclides by workers (1981) Pergamon Press, N.Y., ICRP Publication 12. Wilsey EF, Bloore EW (1989

  12. Carbon sequestration in depleted oil shale deposits

    DOEpatents

    Burnham, Alan K; Carroll, Susan A

    2014-12-02

    A method and apparatus are described for sequestering carbon dioxide underground by mineralizing the carbon dioxide with coinjected fluids and minerals remaining from the extraction shale oil. In one embodiment, the oil shale of an illite-rich oil shale is heated to pyrolyze the shale underground, and carbon dioxide is provided to the remaining depleted oil shale while at an elevated temperature. Conditions are sufficient to mineralize the carbon dioxide.

  13. The ultimate disposition of depleted uranium

    SciTech Connect

    Lemons, T.R.

    1991-12-31

    Depleted uranium (DU) is produced as a by-product of the uranium enrichment process. Over 340,000 MTU of DU in the form of UF{sub 6} have been accumulated at the US government gaseous diffusion plants and the stockpile continues to grow. An overview of issues and objectives associated with the inventory management and the ultimate disposition of this material is presented.

  14. Depletion modeling of liquid dominated geothermal reservoirs

    SciTech Connect

    Olsen, G.

    1984-06-01

    Depletion models for liquid-dominated geothermal reservoirs are derived and presented. The depletion models are divided into two categories: confined and unconfined. For both cases depletion models with no recharge (or influx), and depletion models including recharge, are used to match field data from the Svartsengi high temperature geothermal field in Iceland. The influx models included with the mass and energy balances are adopted from the petroleum engineering literature. The match to production data from Svartsengi is improved when influx was included. The Schilthuis steady-state influx gives a satisfactory match. The finite aquifer method of Fetkovitch, and the unsteady state method of Hurst gave reasonable answers, but not as good. The best match is obtained using Hurst simplified solution when lambda = 1.3 x 10{sup -4} m{sup -1}. From the match the cross-sectional area of the aquifer was calculated as 3.6 km{sup 2}. The drawdown was predicted using the Hurst simplified method, and compared with predicted drawdown from a boiling model and an empirical log-log model. A large difference between the models was obtained. The predicted drawdown using the Hurst simplified method falls between the other two. Injection has been considered by defining the net rate as being the production rate minus the injection rate. No thermal of transient effects were taken into account. Prediction using three different net rates shows that the pressure can be maintained using the Hurst simplified method if there is significant fluid reinjection. 32 refs., 44 figs., 2 tabs.

  15. Characterizing the width of amphibian movements during postbreeding migration.

    PubMed

    Coster, Stephanie S; Veysey Powell, Jessica S; Babbitt, Kimberly J

    2014-06-01

    Habitat linkages can help maintain connectivity of animal populations in developed landscapes. However, the lack of empirical data on the width of lateral movements (i.e., the zigzagging of individuals as they move from one point to point another) makes determining the width of such linkages challenging. We used radiotracking data from wood frogs (Lithobates sylvaticus) and spotted salamanders (Ambystoma maculatum) in a managed forest in Maine (U.S.A.) to characterize movement patterns of populations and thus inform planning for the width of wildlife corridors. For each individual, we calculated the polar coordinates of all locations, estimated the vector sum of the polar coordinates, and measured the distance from each location to the vector sum. By fitting a Gaussian distribution over a histogram of these distances, we created a population-level probability density function and estimated the 50th and 95th percentiles to determine the width of lateral movement as individuals progressed from the pond to upland habitat. For spotted salamanders 50% of lateral movements were ≤13 m wide and 95% of movements were ≤39 m wide. For wood frogs, 50% of lateral movements were ≤17 m wide and 95% of movements were ≤ 51 m wide. For both species, those individuals that traveled the farthest from the pond also displayed the greatest lateral movement. Our results serve as a foundation for spatially explicit conservation planning for pond-breeding amphibians in areas undergoing development. Our technique can also be applied to movement data from other taxa to aid in designing habitat linkages. © 2014 Society for Conservation Biology.

  16. Pulse-Width Dependent Radiation Effects on Electronic Components

    DTIC Science & Technology

    1989-11-01

    d’un accelerateur lineaire ( LINAC ) a et6 realisee par le CRDO et d’autres groupes. Par contre, l’emploi du LINAC donne normalement des impulsions plus... LINAC ) has been performed by DREO and other groups. However, the use of a LINAC normally entails wider pulses than those expected on the battlefield...nuclear weapon on electronics, an electron linear accelerator ( LINAC ) is often used. The pulse widths available from most LINACs are longer than the

  17. Pulse-Width-Modulating Driver for Brushless dc Motor

    NASA Technical Reports Server (NTRS)

    Salomon, Phil M.

    1991-01-01

    High-current pulse-width-modulating driver for brushless dc motor features optical coupling of timing signals from low-current control circuitry to high-current motor-driving circuitry. Provides high electrical isolation of motor-power supply, helping to prevent fast, high-current motor-driving pulses from being coupled through power supplies into control circuitry, where they interfere with low-current control signals.

  18. A Spectral Method for the Equal Width Equation

    NASA Astrophysics Data System (ADS)

    García-Archilla, Bosco

    1996-05-01

    A spectral discretization of the equal width equation (EWE) is presented. The method is shown to be convergent and nonlinearly stable. Time-stepping is performed with high-order Adams methods. The spectral accuracy of the scheme reveals some features of the EWE that the methods previously used could not bare out properly. For instance, we may now study the changes in amplitude and velocity of solitary waves after collisions.

  19. Pulse-Width-Modulating Driver for Brushless dc Motor

    NASA Technical Reports Server (NTRS)

    Salomon, Phil M.

    1991-01-01

    High-current pulse-width-modulating driver for brushless dc motor features optical coupling of timing signals from low-current control circuitry to high-current motor-driving circuitry. Provides high electrical isolation of motor-power supply, helping to prevent fast, high-current motor-driving pulses from being coupled through power supplies into control circuitry, where they interfere with low-current control signals.

  20. Evolution and diversity of subduction zones controlled by slab width.

    PubMed

    Schellart, W P; Freeman, J; Stegman, D R; Moresi, L; May, D

    2007-03-15

    Subducting slabs provide the main driving force for plate motion and flow in the Earth's mantle, and geodynamic, seismic and geochemical studies offer insight into slab dynamics and subduction-induced flow. Most previous geodynamic studies treat subduction zones as either infinite in trench-parallel extent (that is, two-dimensional) or finite in width but fixed in space. Subduction zones and their associated slabs are, however, limited in lateral extent (250-7,400 km) and their three-dimensional geometry evolves over time. Here we show that slab width controls two first-order features of plate tectonics-the curvature of subduction zones and their tendency to retreat backwards with time. Using three-dimensional numerical simulations of free subduction, we show that trench migration rate is inversely related to slab width and depends on proximity to a lateral slab edge. These results are consistent with retreat velocities observed globally, with maximum velocities (6-16 cm yr(-1)) only observed close to slab edges (<1,200 km), whereas far from edges (>2,000 km) retreat velocities are always slow (<2.0 cm yr(-1)). Models with narrow slabs (< or =1,500 km) retreat fast and develop a curved geometry, concave towards the mantle wedge side. Models with slabs intermediate in width ( approximately 2,000-3,000 km) are sublinear and retreat more slowly. Models with wide slabs (> or =4,000 km) are nearly stationary in the centre and develop a convex geometry, whereas trench retreat increases towards concave-shaped edges. Additionally, we identify periods (5-10 Myr) of slow trench advance at the centre of wide slabs. Such wide-slab behaviour may explain mountain building in the central Andes, as being a consequence of its tectonic setting, far from slab edges.

  1. Barium depletion in hollow cathode emitters

    NASA Astrophysics Data System (ADS)

    Polk, James E.; Mikellides, Ioannis G.; Capece, Angela M.; Katz, Ira

    2016-01-01

    Dispenser hollow cathodes rely on a consumable supply of Ba released by BaO-CaO-Al2O3 source material in the pores of a tungsten matrix to maintain a low work function surface. The examination of cathode emitters from long duration tests shows deposits of tungsten at the downstream end that appear to block the flow of Ba from the interior. In addition, a numerical model of Ba transport in the cathode plasma indicates that the Ba partial pressure in the insert may exceed the equilibrium vapor pressure of the dominant Ba-producing reaction, and it was postulated previously that this would suppress Ba loss in the upstream part of the emitter. New measurements of the Ba depletion depth from a cathode insert operated for 8200 h reveal that Ba loss is confined to a narrow region near the downstream end, confirming this hypothesis. The Ba transport model was modified to predict the depletion depth with time. A comparison of the calculated and measured depletion depths gives excellent qualitative agreement, and quantitative agreement was obtained assuming an insert temperature 70 °C lower than measured beginning-of-life values.

  2. Renal cortical pyruvate depletion during AKI.

    PubMed

    Zager, Richard A; Johnson, Ali C M; Becker, Kirsten

    2014-05-01

    Pyruvate is a key intermediary in energy metabolism and can exert antioxidant and anti-inflammatory effects. However, the fate of pyruvate during AKI remains unknown. Here, we assessed renal cortical pyruvate and its major determinants (glycolysis, gluconeogenesis, pyruvate dehydrogenase [PDH], and H2O2 levels) in mice subjected to unilateral ischemia (15-60 minutes; 0-18 hours of vascular reflow) or glycerol-induced ARF. The fate of postischemic lactate, which can be converted back to pyruvate by lactate dehydrogenase, was also addressed. Ischemia and glycerol each induced persistent pyruvate depletion. During ischemia, decreasing pyruvate levels correlated with increasing lactate levels. During early reperfusion, pyruvate levels remained depressed, but lactate levels fell below control levels, likely as a result of rapid renal lactate efflux. During late reperfusion and glycerol-induced AKI, pyruvate depletion corresponded with increased gluconeogenesis (pyruvate consumption). This finding was underscored by observations that pyruvate injection increased renal cortical glucose content in AKI but not normal kidneys. AKI decreased PDH levels, potentially limiting pyruvate to acetyl CoA conversion. Notably, pyruvate therapy mitigated the severity of AKI. This renoprotection corresponded with increases in cytoprotective heme oxygenase 1 and IL-10 mRNAs, selective reductions in proinflammatory mRNAs (e.g., MCP-1 and TNF-α), and improved tissue ATP levels. Paradoxically, pyruvate increased cortical H2O2 levels. We conclude that AKI induces a profound and persistent depletion of renal cortical pyruvate, which may induce additional injury.

  3. Barium depletion in hollow cathode emitters

    SciTech Connect

    Polk, James E. Mikellides, Ioannis G.; Katz, Ira; Capece, Angela M.

    2016-01-14

    Dispenser hollow cathodes rely on a consumable supply of Ba released by BaO-CaO-Al{sub 2}O{sub 3} source material in the pores of a tungsten matrix to maintain a low work function surface. The examination of cathode emitters from long duration tests shows deposits of tungsten at the downstream end that appear to block the flow of Ba from the interior. In addition, a numerical model of Ba transport in the cathode plasma indicates that the Ba partial pressure in the insert may exceed the equilibrium vapor pressure of the dominant Ba-producing reaction, and it was postulated previously that this would suppress Ba loss in the upstream part of the emitter. New measurements of the Ba depletion depth from a cathode insert operated for 8200 h reveal that Ba loss is confined to a narrow region near the downstream end, confirming this hypothesis. The Ba transport model was modified to predict the depletion depth with time. A comparison of the calculated and measured depletion depths gives excellent qualitative agreement, and quantitative agreement was obtained assuming an insert temperature 70 °C lower than measured beginning-of-life values.

  4. Pumping test evaluation of stream depletion parameters.

    PubMed

    Lough, Hilary K; Hunt, Bruce

    2006-01-01

    Descriptions are given of a pumping test and a corresponding analysis that permit calculation of all five hydrogeological parameters appearing in the Hunt (2003) solution for stream depletion caused by ground water abstraction from a well beside a stream. This solution assumes that flow in the pumped aquifer is horizontal, flow in the overlying aquitard or system of aquitards is vertical, and the free surface in the top aquitard is allowed to draw down. The definition of an aquitard in this paper is any layer with a vertical hydraulic conductivity much lower than the horizontal hydraulic conductivity of the pumped aquifer. These "aquitards" may be reasonably permeable layers but are distinguished from the pumped aquifer by their hydraulic conductivity contrast. The pumping test requires a complete set of drawdown measurements from at least one observation well. This well must be deep enough to penetrate the pumped aquifer, and pumping must continue for a sufficient time to ensure that depleted streamflow becomes a significant portion of the well abstraction rate. Furthermore, two of the five parameters characterize an aquitard that overlies the pumped aquifer, and values for these parameters are seen to be dependent upon the initial water table elevation in the aquitard. The field test analyzed herein used a total of eight observation wells screened in the pumped aquifer, and measurements from these wells gave eight sets of parameters that are used in a sensitivity analysis to determine the relative importance of each parameter in the stream depletion calculations.

  5. Understanding the haling power depletion (HPD) method

    SciTech Connect

    Levine, S.; Blyth, T.; Ivanov, K.

    2012-07-01

    The Pennsylvania State Univ. (PSU) is using the university version of the Studsvik Scandpower Code System (CMS) for research and education purposes. Preparations have been made to incorporate the CMS into the PSU Nuclear Engineering graduate class 'Nuclear Fuel Management' course. The information presented in this paper was developed during the preparation of the material for the course. The Haling Power Depletion (HPD) was presented in the course for the first time. The HPD method has been criticized as not valid by many in the field even though it has been successfully applied at PSU for the past 20 years. It was noticed that the radial power distribution (RPD) for low leakage cores during depletion remained similar to that of the HPD during most of the cycle. Thus, the Haling Power Depletion (HPD) may be used conveniently mainly for low leakage cores. Studies were then made to better understand the HPD and the results are presented in this paper. Many different core configurations can be computed quickly with the HPD without using Burnable Poisons (BP) to produce several excellent low leakage core configurations that are viable for power production. Once the HPD core configuration is chosen for further analysis, techniques are available for establishing the BP design to prevent violating any of the safety constraints in such HPD calculated cores. In summary, in this paper it has been shown that the HPD method can be used for guiding the design for the low leakage core. (authors)

  6. A New Measurement of the Pi0 Radiative Decay Width

    SciTech Connect

    Larin, I; Clinton, E; Ambrozewicz, P; Lawrence, D; Nakagawa, I; Prok, Y; Teymurazyan, A; Ahmidouch, A; Baker, K; Benton, L; Bernstein, A M; Burkert, V; Cole, P; Collins, P; Dale, D; Danagoulian, S; Davidenko, G; Demirchyan, R; Deur, A; Dolgolenko, A; Dzyubenko, Georgiy; Ent, R; Evdokimov, A; Feng, J; Gabrielyan, M; Gan, L; Gasparian, A; Gevorkyan, S; Glamazdin, A; Goryachev, V; Gyurjyan, V; Hardy, K; He, J; Ito, M; Jiang, L; Kashy, D; Khandaker, M; Kingsberry, P; Kolarkar, A; Konchatnyi, M; Korsch, W; Kowalski, S; Kubantsev, M; Kubarovsky, V; Li, X; Martel, P; Mecking, B; Milbrath, B; Minehart, R; Miskimen, R; Mochalov, V; Mtingwa, S; Overby, S; Pasyuk, E; Payen, M; Pedroni, R; Ritchie, B; Rodrigues, T E; Salgado, C; Shahinyan, A; Sitnikov, A; Sober, D; Stepanyan, S; Stephens, W; Underwood, J; Vishnyakov, V; Wood, M

    2011-04-01

    High precision measurements of the differential cross sections for $\\pi^0$ photoproduction at forward angles for two nuclei, $^{12}$C and $^{208}$Pb, have been performed for incident photon energies of 4.9 - 5.5 GeV to extract the ${\\pi^0 \\to \\gamma\\gamma}$ decay width. The experiment was done at Jefferson Lab using the Hall~B photon tagger and a high-resolution multichannel calorimeter. The ${\\pi^0 \\to \\gamma\\gamma}$ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is $\\Gamma{(\\pi^0 \\to \\gamma\\gamma)} = 7.82 \\pm 0.14 ~({\\rm stat.}) \\pm 0.17 ~({\\rm syst.}) ~{\\rm eV}$. With the 2.8\\% total uncertainty, this result is a factor of 2.5 more precise than the current PDG average of this fundamental quantity and it is consistent with current theoretical predictions.

  7. Predictors of the peak width for networks with exponential links

    USGS Publications Warehouse

    Troutman, B.M.; Karlinger, M.R.

    1989-01-01

    We investigate optimal predictors of the peak (S) and distance to peak (T) of the width function of drainage networks under the assumption that the networks are topologically random with independent and exponentially distributed link lengths. Analytical results are derived using the fact that, under these assumptions, the width function is a homogeneous Markov birth-death process. In particular, exact expressions are derived for the asymptotic conditional expectations of S and T given network magnitude N and given mainstream length H. In addition, a simulation study is performed to examine various predictors of S and T, including N, H, and basin morphometric properties; non-asymptotic conditional expectations and variances are estimated. The best single predictor of S is N, of T is H, and of the scaled peak (S divided by the area under the width function) is H. Finally, expressions tested on a set of drainage basins from the state of Wyoming perform reasonably well in predicting S and T despite probable violations of the original assumptions. ?? 1989 Springer-Verlag.

  8. Quantum corral resonance widths: lossy scattering as acoustics.

    PubMed

    Barr, Matthew C; Zaletel, Michael P; Heller, Eric J

    2010-09-08

    We present an approach to predicting extrinsic electron resonance widths within quantum corral nanostructures based on analogies with acoustics. Established quantum mechanical methods for calculating resonance widths, such as multiple scattering theory, build up the scattering atom by atom, ignoring the structure formed by the atoms, such as walls or enclosures. Conversely, particle-in-a-box models, assuming continuous walls, have long been successful in predicting quantum corral energy levels, but not resonance widths. In acoustics, partial reflection from walls and various enclosures has long been incorporated for determining reverberation times. Pursuing an exact analogy between the local density of states of a quantum corral and the acoustic impedance of a concert hall, we show electron lifetimes in nanoscopic structures of arbitrary convex shape are well accounted for by the Sabine formula for acoustic reverberation times. This provides a particularly compact and intuitive prescription for extrinsic finite lifetimes in a particle-in-a-box with leaky walls, including quantum corral atomic walls, given single particle scattering properties.

  9. Control of shape memory alloy actuator using pulse width modulation

    NASA Astrophysics Data System (ADS)

    Ma, N.; Song, G.

    2003-10-01

    Shape memory alloys (SMA), in particular nickel-titanium alloy (or nitinol), have been used as actuators in some astronautic, aeronautic and industrial applications. The future will see more SMA application if less energy is required for actuation. This paper presents the design and experimental results of control of an SMA actuator using pulse width modulation (PWM) to reduce the energy consumption by the SMA actuator. A SMA wire test stand is used in this research. Open-loop testing of the SMA wire actuator is conducted to study the effect of the PWM parameters. Based on test results and parameter analysis of the pulse width (PW) modulator, a PW modulator is designed to modulate a proportional plus derivative (PD) controller. Experiments demonstrate that control of the SMA actuator using PWM effectively saves actuation energy while maintaining the same control accuracy as compared to continuous PD control. PWM also demonstrates robustness to external disturbances. A comparison with a pulse width pulse frequency modulator is also presented.

  10. Optimization of Gaussian beam widths in acoustic propagation

    NASA Astrophysics Data System (ADS)

    Gordon, D. F.

    1989-10-01

    The use of Gaussian beams to compute wave propagation phenomena is a field of current interest and activity. Porter and Bucker (1987) supply an extensive list of references. More recent references can be found in Benites and Aki (1989). Gaussian beams can be traced as rays in range-dependent media providing not only propagation loss, but travel times, multipath structure, and frequency dependence. The well-known ray theory problems of caustics and shadow zones are treated automatically. A beam width minimization technique applied to a Gaussian beam model developed by Dr. H. P. Bucker, is outlined. Porter and Bucker (1987) gives the formulation upon which the techniques is built. A free parameter E is usually determined in a heuristic manner. Here, it is shown that the minimization of beam width assigns a precise value to E. Examples are given showing that the minimized beams give good propagation losses in some cases. A case also shown in the standard Gaussian beams give poor results and the minimized beams give even worse results. The problem appears to arise in beams that pass near boundaries. This problem will have to be corrected before a final judgment can be made on the validity of minimum-width beams.

  11. Axial couplings and strong decay widths of heavy hadrons.

    PubMed

    Detmold, William; Lin, C-J David; Meinel, Stefan

    2012-04-27

    We calculate the axial couplings of mesons and baryons containing a heavy quark in the static limit using lattice QCD. These couplings determine the leading interactions in heavy hadron chiral perturbation theory and are central quantities in heavy quark physics, as they control strong decay widths and the light quark mass dependence of heavy hadron observables. Our analysis makes use of lattice data at six different pion masses, 227 MeVwidths with experimental data for Σ(c)(*) decays, we obtain Γ[Σ(b)(*)→Λ(b)π(±)]=4.2(1.0), 4.8(1.1), 7.3(1.6), 7.8(1.8) MeV for the Σ(b)(+), Σ(b)(-), Σ(b)(*+), Σ(b)(*-) initial states, respectively. We also derive upper bounds on the widths of the Ξ(b)(I(*)) baryons.

  12. Maxillary and mandibular anterior crown width/height ratio and its relation to various arch perimeters, arch length, and arch width groups

    PubMed Central

    Shahid, Fazal; Alam, Mohammad Khursheed; Khamis, Mohd Fadhli

    2015-01-01

    Objective: To investigate the maxillary and mandibular anterior crown width/height ratio and its relation to various arch perimeters, arch length, and arch width (intercanine, interpremolar, and intermolar) groups. Materials and Methods: The calculated sample size was 128 subjects. The crown width/height, arch length, arch perimeter, and arch width of the maxilla and mandible were obtained via digital calliper (Mitutoyo, Japan). A total of 4325 variables were measured. The sex differences in the crown width and height were evaluated. Analysis of variance was applied to evaluate the differences between arch length, arch perimeter, and arch width groups. Results: Males had significantly larger mean values for crown width and height than females (P ≤ 0.05) for maxillary and mandibular arches, both. There were no significant differences observed for the crown width/height ratio in various arch length, arch perimeter, and arch width (intercanine, interpremolar, and intermolar) groups (P ≤ 0.05) in maxilla and mandible, both. Conclusions: Our results indicate sexual disparities in the crown width and height. Crown width and height has no significant relation to various arch length, arch perimeter, and arch width groups of maxilla and mandible. Thus, it may be helpful for orthodontic and prosthodontic case investigations and comprehensive management. PMID:26929686

  13. First tests with fully depleted PN-CCD's

    SciTech Connect

    Strueder, L.; Lutz, G.; Sterzik, M.; Holl, P.; Kemmer, J.; Prechtel, U.; Ziemann, T.; Rehak, P.

    1987-01-01

    We have fabricated 280 ..mu..m thick fully depletable pn CCD's on high resistivity silicon ()rho) approx. 2.5 k..cap omega..cm). Its operation is based on the semiconductor drift chamber principle proposed by Gatti and Rheak. They are designed as energy and position sensitive radiation detector for (minimum) ionizing particles and X-ray imaging. Two dimensional semiconductor device modeling demonstrates the basic charge transer mechanisms. Prototypes of the detectors have been tested in static and dynamic conditions. A preliminary charge transfer inefficiency was determined to 6 x 10)sup)minus)3). The charge loss during the transfer is discussed and as a consequence we have developed an improved design for a second fabrication iteration which is now being produced. 4 refs., 15 figs.

  14. A mathematical model for meandering rivers with varying width

    NASA Astrophysics Data System (ADS)

    Frascati, Alessandro; Lanzoni, Stefano

    2013-09-01

    The mathematical modeling of the long-term evolution of meandering rivers needs an efficient computation of the flow field. Indeed, the estimate of the near bank velocity, needed to determine the rate at which the outer bank migrates, cannot rely on the full numerical solution of the governing equations when considering the river evolution on geological time scales. The aim of the present contribution is twofold: determining the complete linear response of a meandering river to spatially varying channel axis curvature and width, exploiting the ability of the model to describe the morphological tendencies of alluvial rivers; and developing a computationally efficient tool that can be easily incorporated in long-term planform evolution models. The centrifugally induced secondary flow associated with channel axis curvature and longitudinal convection is accounted for by a suitable parametrization based on the structure of the three-dimensional flow field. Cross section width variations are accounted for through a suitable stretching of the transverse coordinate. The relevant momentum and mass conservation equations are then linearized by taking advantage of the fact that alluvial rivers often exhibit mild and long meander bends, as well as evident but relatively small width variations. The input data needed by the analytical solution are the spatial distribution of channel axis curvature and width variations, the mean slope of the investigated river reach, the characteristic grain size of the sediment bed and the flow discharge. The performances of the model, as well as its intrinsic limitations are discussed with reference to the comparison with the bed topography surveyed in a 21 km long reach of the Po River. The results indicate that, in the presence of wide, mildly curved and long bend and weak width variations, the river topography is described with a good accuracy, thus supporting the use of the model to investigate how a river could react to changes in

  15. Fully depleted CMOS pixel sensor development and potential applications

    SciTech Connect

    Baudot, J.; Kachel, M.

    2015-07-01

    CMOS pixel sensors are often opposed to hybrid pixel sensors due to their very different sensitive layer. In standard CMOS imaging processes, a thin (about 20 μm) low resistivity epitaxial layer acts as the sensitive volume and charge collection is mostly driven by thermal agitation. In contrast, the so-called hybrid pixel technology exploits a thick (typically 300 μm) silicon sensor with high resistivity allowing for the depletion of this volume, hence charges drift toward collecting electrodes. But this difference is fading away with the recent availability of some CMOS imaging processes based on a relatively thick (about 50 μm) high resistivity epitaxial layer which allows for full depletion. This evolution extents the range of applications for CMOS pixel sensors where their known assets, high sensitivity and granularity combined with embedded signal treatment, could potentially foster breakthrough in detection performances for specific scientific instruments. One such domain is the Xray detection for soft energies, typically below 10 keV, where the thin sensitive layer was previously severely impeding CMOS sensor usage. Another application becoming realistic for CMOS sensors, is the detection in environment with a high fluence of non-ionizing radiation, such as hadron colliders. However, when considering highly demanding applications, it is still to be proven that micro-circuits required to uniformly deplete the sensor at the pixel level, do not mitigate the sensitivity and efficiency required. Prototype sensors in two different technologies with resistivity higher than 1 kΩ, sensitive layer between 40 and 50 μm and featuring pixel pitch in the range 25 to 50 μm, have been designed and fabricated. Various biasing architectures were adopted to reach full depletion with only a few volts. Laboratory investigations with three types of sources (X-rays, β-rays and infrared light) demonstrated the validity of the approach with respect to depletion, keeping a

  16. The TESS camera: modeling and measurements with deep depletion devices

    NASA Astrophysics Data System (ADS)

    Woods, Deborah F.; Vanderspek, Roland; MacDonald, Robert; Morgan, Edward; Villasenor, Joel; Thayer, Carolyn; Burke, Barry; Chesbrough, Christian; Chrisp, Michael; Clark, Kristin; Furesz, Gabor; Gonzales, Alexandria; Nguyen, Tam; Prigozhin, Gregory; Primeau, Brian; Ricker, George; Sauerwein, Timothy; Suntharalingam, Vyshnavi

    2016-07-01

    The Transiting Exoplanet Survey Satellite, a NASA Explorer-class mission in development, will discover planets around nearby stars, most notably Earth-like planets with potential for follow up characterization. The all-sky survey requires a suite of four wide field-of-view cameras with sensitivity across a broad spectrum. Deep depletion CCDs with a silicon layer of 100 μm thickness serve as the camera detectors, providing enhanced performance in the red wavelengths for sensitivity to cooler stars. The performance of the camera is critical for the mission objectives, with both the optical system and the CCD detectors contributing to the realized image quality. Expectations for image quality are studied using a combination of optical ray tracing in Zemax and simulations in Matlab to account for the interaction of the incoming photons with the 100 μm silicon layer. The simulations include a probabilistic model to determine the depth of travel in the silicon before the photons are converted to photo-electrons, and a Monte Carlo approach to charge diffusion. The charge diffusion model varies with the remaining depth for the photo-electron to traverse and the strength of the intermediate electric field. The simulations are compared with laboratory measurements acquired by an engineering unit camera with the TESS optical design and deep depletion CCDs. In this paper we describe the performance simulations and the corresponding measurements taken with the engineering unit camera, and discuss where the models agree well in predicted trends and where there are differences compared to observations.

  17. Involvement of Zn Depletion in Cd-Induced Toxicity on Prenatal Bone Formation in Rat.

    PubMed

    Boughammoura, Sana; Chemek, Marouane; Mimouna, Safa Ben; Banni, Mohamed; Messaoudi, Imed

    2017-03-06

    This study explored the potential toxicity of Cd on the Zn bone depletion in prenatal bone formation. Female rats received either tap water, Cd, Zn, or Cd + Zn in their drinking water during gestation, and some markers of bone formation were studied in their fetuses removed at the 20th day of pregnancy (GD20). Cd exposure induced maternal hypozincemia and Zn depletion in the femur of the fetuses. A striking inhibition of bone formation in fetuses, expressed by decreases in femur length, width, and area, by the shortening of diaphysis, and by a decrease in length and area of distal and proximal proliferative zones, was observed in fetuses from Cd-exposed mothers. At the molecular level, Cd caused upregulation of MT-1 and ZIP2 genes and significantly depressed the expression of the ZnT5, colα1, osteocalcin, and ALP genes in the femur. Interestingly, Zn treatment ameliorated the Cd-induced maternal hypozincemia and femoral changes and partially restored the normal histomorphometry of the femur. These results suggest that the observed toxic effects of Cd are, at least in part, mediated by the disruption of maternal Zn metabolism during pregnancy leading to Zn depletion and thus to perturbation of prenatal bone formation.

  18. 26 CFR 1.642(e)-1 - Depreciation and depletion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Depreciation and depletion. 1.642(e)-1 Section 1... (CONTINUED) INCOME TAXES Estates, Trusts, and Beneficiaries § 1.642(e)-1 Depreciation and depletion. An estate or trust is allowed the deductions for depreciation and depletion, but only to the extent...

  19. 26 CFR 52.4682-1 - Ozone-depleting chemicals.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 17 2013-04-01 2013-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section...

  20. 26 CFR 52.4682-1 - Ozone-depleting chemicals.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 17 2011-04-01 2011-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section...

  1. 26 CFR 52.4682-1 - Ozone-depleting chemicals.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 17 2014-04-01 2014-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section...

  2. 26 CFR 52.4682-1 - Ozone-depleting chemicals.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 17 2012-04-01 2012-04-01 false Ozone-depleting chemicals. 52.4682-1 Section 52... EXCISE TAXES (CONTINUED) ENVIRONMENTAL TAXES § 52.4682-1 Ozone-depleting chemicals. (a) Overview. This section provides rules relating to the tax imposed on ozone-depleting chemicals (ODCs) under section...

  3. Children's Models of the Ozone Layer and Ozone Depletion.

    ERIC Educational Resources Information Center

    Christidou, Vasilia; Koulaidis, Vasilis

    1996-01-01

    The views of 40 primary students on ozone and its depletion were recorded through individual, semi-structured interviews. The data analysis resulted in the formation of a limited number of models concerning the distribution and role of ozone in the atmosphere, the depletion process, and the consequences of ozone depletion. Identifies five target…

  4. Children's Models of the Ozone Layer and Ozone Depletion.

    ERIC Educational Resources Information Center

    Christidou, Vasilia; Koulaidis, Vasilis

    1996-01-01

    The views of 40 primary students on ozone and its depletion were recorded through individual, semi-structured interviews. The data analysis resulted in the formation of a limited number of models concerning the distribution and role of ozone in the atmosphere, the depletion process, and the consequences of ozone depletion. Identifies five target…

  5. Potential For Stratospheric Ozone Depletion During Carboniferous

    NASA Astrophysics Data System (ADS)

    Bill, M.; Goldstein, A. H.

    Methyl bromide (CH3Br) constitutes the largest source of bromine atoms to the strato- sphere whereas methyl chloride (CH3Cl) is the most abundant halocarbon in the tro- posphere. Both gases play an important role in stratospheric ozone depletion. For in- stance, Br coupled reactions are responsible for 30 to 50 % of total ozone loss in the polar vortex. Currently, the largest natural sources of CH3Br and CH3Cl appear to be biological production in the oceans, inorganic production during biomass burning and plant production in salt marsh ecosystems. Variations of paleofluxes of CH3Br and CH3Cl can be estimated by analyses of oceanic paleoproductivity, stratigraphic analyses of frequency and distribution of fossil charcoal indicating the occurrence of wildfires, and/or by paleoreconstruction indicating the extent of salt marshes. Dur- ing the lower Carboniferous time (Tournaisian-Visean), the southern margin of the Laurasian continent was characterized by charcoal deposits. Estimation on frequency of charcoal layers indicates that wildfires occur in a range of 3-35 years (Falcon-Lang 2000). This suggests that biomass burning could be an important source of CH3Br and CH3Cl during Tournaisian-Viesan time. During Tounaisian and until Merame- cian carbon and oxygen isotope records have short term oscillations (Bruckschen et al. 1999, Mii et al. 1999). Chesterian time (mid- Carboniferous) is marked by an in- crease in delta18O values ( ~ 2 permil) and an increase of glacial deposit frequency suggesting lower temperatures. The occurrence of glacial deposits over the paleopole suggests polar conditions and the associated special features of polar mete- orology such as strong circumpolar wind in the stratosphere (polar vortex) and polar stratospheric clouds. Thus, conditions leading to polar statospheric ozone depletion can be found. Simultaneously an increase in delta13C values is documented. We interpret the positive shift in delta13C as a result of higher bioproductivity

  6. Evolution of the Depleted Mantle--Revisited

    NASA Astrophysics Data System (ADS)

    Vervoort, J. D.

    2011-12-01

    One of the basic tenets of radiogenic isotope geochemistry is that the Earth's crust has been extracted from the mantle leaving the mantle depleted in incompatible elements. Two tracers that have been used to constrain depleted mantle (DM) evolution are the long-lived radiogenic isotope systems Sm-Nd and Lu-Hf. It has long been assumed that Nd evolution of the depleted mantle follows a ~ linear path from chondritic composition (ɛNd = 0) at ~4.5 Ga to depleted MORB mantle (DMM) today (ɛNd = +10) [e.g., 1]. The Hf isotope system, before the revision of the 176Lu decay constant [2,3], appeared follow a similar evolution: chondritic at ~4.5 Ga to DMM today [4]. This relationship, however, changed radically with the revision of the 176Lu decay constant. Now, for the Lu-Hf isotope system, there is no evidence of a widespread depleted mantle prior to 3.5 Ga. Using the new decay constant and CHUR values [5], Hf data for juvenile, mantle-derived rocks through time define a trend that does not diverge from chondritic compositions until after 3.5 Ga. This new Hf DM evolution is defined by average DMM today (176Hf/177Hf = 0.28321, ɛHf =~ +15) and using 176Lu/177Hf = 0.0399 to calculate compositions back in time to CHUR at 3.5 Ga. The Hf-Nd isotope records, therefore, appear to indicate different evolutionary histories: Nd isotopes show evidence for widespread depleted mantle from the earliest preserved rocks [6] and; Hf isotopes show only chondritic to enriched sources for the oldest preserved rocks [7]. This "Hf-Nd paradox", if the reference frames are correct, would imply that differentiation of the early Earth affected the Sm-Nd and Lu-Hf systems in fundamentally differently ways-a premise that seems difficult to explain. A further complication in the Hf and Nd evolution of the Earth comes from the short-lived isotope system 146Sm-142Nd. An unavoidable consequence of the 142Nd data is that the silicate Earth sampled thus far has a super chondritic Sm/Nd composition [e

  7. A modern depleted uranium manufacturing facility

    SciTech Connect

    Zagula, T.A.

    1995-07-01

    The Specific Manufacturing Capabilities (SMC) Project located at the Idaho National Engineering Laboratory (INEL) and operated by Lockheed Martin Idaho Technologies Co. (LMIT) for the Department of Energy (DOE) manufactures depleted uranium for use in the U.S. Army MIA2 Abrams Heavy Tank Armor Program. Since 1986, SMC has fabricated more than 12 million pounds of depleted uranium (DU) products in a multitude of shapes and sizes with varying metallurgical properties while maintaining security, environmental, health and safety requirements. During initial facility design in the early 1980`s, emphasis on employee safety, radiation control and environmental consciousness was gaining momentum throughout the DOE complex. This fact coupled with security and production requirements forced design efforts to focus on incorporating automation, local containment and computerized material accountability at all work stations. The result was a fully automated production facility engineered to manufacture DU armor packages with virtually no human contact while maintaining security, traceability and quality requirements. This hands off approach to handling depleted uranium resulted in minimal radiation exposures and employee injuries. Construction of the manufacturing facility was complete in early 1986 with the first armor package certified in October 1986. Rolling facility construction was completed in 1987 with the first certified plate produced in the fall of 1988. Since 1988 the rolling and manufacturing facilities have delivered more than 2600 armor packages on schedule with 100% final product quality acceptance. During this period there was an annual average of only 2.2 lost time incidents and a single individual maximum radiation exposure of 150 mrem. SMC is an example of designing and operating a facility that meets regulatory requirements with respect to national security, radiation control and personnel safety while achieving production schedules and product quality.

  8. Pumping induced depletion from two streams

    NASA Astrophysics Data System (ADS)

    Sun, Dongmin; Zhan, Hongbin

    2007-04-01

    We have proved that the Hantush's model [Hantush MS. Wells near streams with semipervious beds. J Geophys Res 1965;70:2829-38] in a half-domain can be extended to a whole-domain and becomes identical to that of Hunt [Hunt B. Unsteady stream depletion from ground water pumping. Ground Water 1999;37(1):98-102] for a shallow and infinitely narrow stream, provided that the Dupuit assumption is adopted. This proof helps correct a false concept that regards the Hantush's model as less useful because of its fully penetrating stream assumption. This study deals with interaction of an aquifer with two parallel streams based on the Hantush's model. Semi-analytical solutions are obtained based on rigorous mass conservation requirement by maintaining continuity of flux and head along the aquifer-streambed boundaries. This study shows that the hydraulic conductivity ratio of the two streambeds appears to be the most important factor controlling the stream-aquifer interaction, followed by a less important role played by the thickness ratio of the two streambeds. When the low-permeability streambeds do not exist, the steady-state stream depletion from one stream is linearly proportional to the ratio of the shortest distance from the pumping well to the other stream over the shortest distance between the two streams. When the low-permeability streambeds are presented, similar conclusion can be drawn except that the stream depletion now also strongly depends on the hydraulic conductivity ratio of the two streambeds. When the values of the hydraulic conductivity of the two streambeds are different by an order of magnitude, the location of the pumping well that receives equal flux from two streams can be off the middle-line between the two streams by nearly 90%.

  9. Rhenium Disulfide Depletion-Load Inverter

    NASA Astrophysics Data System (ADS)

    McClellan, Connor; Corbet, Chris; Rai, Amritesh; Movva, Hema C. P.; Tutuc, Emanuel; Banerjee, Sanjay K.

    2015-03-01

    Many semiconducting Transition Metal Dichalcogenide (TMD) materials have been effectively used to create Field-Effect Transistor (FET) devices but have yet to be used in logic designs. We constructed a depletion-load voltage inverter using ultrathin layers of Rhenium Disulfide (ReS2) as the semiconducting channel. This ReS2 inverter was fabricated on a single micromechanically-exfoliated flake of ReS2. Electron beam lithography and physical vapor deposition were used to construct Cr/Au electrical contacts, an Alumina top-gate dielectric, and metal top-gate electrodes. By using both low (Aluminum) and high (Palladium) work-function metals as two separate top-gates on a single ReS2 flake, we create a dual-gated depletion mode (D-mode) and enhancement mode (E-mode) FETs in series. Both FETs displayed current saturation in the output characteristics as a result of the FET ``pinch-off'' mechanism and On/Off current ratios of 105. Field-effect mobilities of 23 and 17 cm2V-1s-1 and subthreshold swings of 97 and 551 mV/decade were calculated for the E-mode and D-mode FETs, respectively. With a supply voltage of 1V, at low/negative input voltages the inverter output was at a high logic state of 900 mV. Conversely with high/positive input voltages, the inverter output was at a low logic state of 500 mV. The inversion of the input signal demonstrates the potential for using ReS2 in future integrated circuit designs and the versatility of depletion-load logic devices for TMD research. NRI SWAN Center and ARL STTR Program.

  10. Axial couplings and strong decay widths of heavy hadrons

    SciTech Connect

    William Detmold, C.-J. David Lin, Stefan Meinel

    2012-04-01

    We calculate the axial couplings of mesons and baryons containing a heavy quark in the static limit using lattice QCD. These couplings determine the leading interactions in heavy hadron chiral perturbation theory and are central quantities in heavy quark physics, as they control strong decay widths and the light-quark mass dependence of heavy hadron observables. Our analysis makes use of lattice data at six different pion masses, 227 MeV < m{sub {pi}} < 352 MeV, two lattice spacings, a = 0.085, 0.112 fm, and a volume of (2.7 fm){sup 3}. Our results for the axial couplings are g{sub 1} = 0.449(51), g{sub 2} = 0.84(20), and g{sub 3} = 0.71(13), where g{sub 1} governs the interaction between heavy-light mesons and pions and g{sub 2,3} are similar couplings between heavy-light baryons and pions. Using our lattice result for g{sub 3}, and constraining 1/m{sub Q} corrections in the strong decay widths with experimental data for {Sigma}{sub c}{sup (*)} decays, we obtain {Gamma}[{Sigma}{sub b}{sup (*)} {yields} {Lambda}{sub b} {pi}{sup {+-}}] = 4.2(1.0), 4.8(1.1), 7.3(1.6), 7.8(1.8) MeV for the {Sigma}{sub b}{sup +}, {Sigma}{sub b}{sup -}, {Sigma}{sub b}{sup *+}, {Sigma}{sub b}{sup *-} initial states, respectively. We also derive upper bounds on the widths of the {Xi}{sub b}{sup prime(*)} baryons.

  11. Importance of Mean Red Cell Distribution Width in Hypertensive Patients

    PubMed Central

    Bilal, Ahmed; Farooq, Junaid H; Assad, Salman; Ghazanfar, Haider; Ahmed, Imran

    2016-01-01

    Purpose Red cell distribution width (RDW), expressed in femtoliters (fl), is a measure of the variation in the size of circulating erythrocytes and is often expressed as a direct measurement of the width of the distribution. We aim to observe the mean value of red cell distribution width (RDW) in hypertensive patients. Increased RDW can be used as a tool for early diagnosis, as an inflammatory marker, and a mortality indicator in hypertensive patients due to its close relation to inflammation. Materials and methodology Hypertensive patients who had the condition for more than one year duration, diagnosed according to the Joint National Committee (JNC 7) criteria were subjected to complete blood count and RDW measurement. One hundred patients, aged between 12 years and 65 years were enrolled from the outpatient department of medicine at the Military Hospital Rawalpindi. Results The mean age (± SD) of the patients was 51.48 ± 10.08 years. Out of 100 patients 69% were males whereas 31% were females. The overall frequency of hypertension more than five years was 55% subjects whereas 45% individuals had duration of hypertension less than five years. Mean RDW in females was found to be 49.35±8.42 fl while mean RDW in males was 44.78±7.11 fl. An independent sample t-test was applied to assess if there was any significant difference between age and gender. No significant difference between age and gender was found (p<0.05). The Mann-Whitney test was used to assess any association of RDW with gender. RDW values in females was found to be statistically significantly higher than in males (U=603, p=0.01). Linear regression showed that mean RDW value increased with increasing age (P <0.001). Conclusions A significant number of patients with hypertension have increased levels of RDW. Therefore, it is recommended that serum RDW should be checked regularly in patients with hypertension. PMID:28070471

  12. Effect of stance width on multidirectional postural responses

    NASA Technical Reports Server (NTRS)

    Henry, S. M.; Fung, J.; Horak, F. B.; Peterson, B. W. (Principal Investigator)

    2001-01-01

    The effect of stance width on postural responses to 12 different directions of surface translations was examined. Postural responses were characterized by recording 11 lower limb and trunk muscles, body kinematics, and forces exerted under each foot of 7 healthy subjects while they were subjected to horizontal surface translations in 12 different, randomly presented directions. A quasi-static approach of force analysis was done, examining force integrals in three different epochs (background, passive, and active periods). The latency and amplitude of muscle responses were quantified for each direction, and muscle tuning curves were used to determine the spatial activation patterns for each muscle. The results demonstrate that the horizontal force constraint exerted at the ground was lessened in the wide, compared with narrow, stance for humans, a similar finding to that reported by Macpherson for cats. Despite more trunk displacement in narrow stance, there were no significant changes in body center of mass (CoM) displacement due to large changes in center of pressure (CoP), especially in response to lateral translations. Electromyographic (EMG) magnitude decreased for all directions in wide stance, particularly for the more proximal muscles, whereas latencies remained the same from narrow to wide stance. Equilibrium control in narrow stance was more of an active postural strategy that included regulating the loading/unloading of the limbs and the direction of horizontal force vectors. In wide stance, equilibrium control relied more on an increase in passive stiffness resulting from changes in limb geometry. The selective latency modulation of the proximal muscles with translation direction suggests that the trunk was being actively controlled in all directions. The similar EMG latencies for both narrow and wide stance, with modulation of only the muscle activation magnitude as stance width changed, suggest that the same postural synergy was only slightly modified

  13. Width of the confining string in Yang-Mills theory.

    PubMed

    Gliozzi, F; Pepe, M; Wiese, U-J

    2010-06-11

    We investigate the transverse fluctuations of the confining string connecting two static quarks in (2+1)D SU(2) Yang-Mills theory using Monte Carlo calculations. The exponentially suppressed signal is extracted from the large noise by a very efficient multilevel algorithm. The resulting width of the string increases logarithmically with the distance between the static quark charges. Corrections at intermediate distances due to universal higher-order terms in the effective string action are calculated analytically. They accurately fit the numerical data.

  14. Microsecond pulse width, intense, light-ion beam accelerator

    NASA Astrophysics Data System (ADS)

    Rej, D. J.; Bartsch, R. R.; Davis, H. A.; Faehl, R. J.; Greenly, J. B.; Waganaar, W. J.

    1993-10-01

    A relatively long-pulse width (0.1-1 μs) intense ion beam accelerator has been built for materials processing applications. An applied Br, magnetically insulated extraction ion diode with dielectric flashover ion source is installed directly onto the output of a 1.2 MV, 300-kJ Marx generator. The diode is designed with the aid of multidimensional particle-in-cell simulations. Initial operation of the accelerator at 0.4 MV indicates satisfactory performance without the need for additional pulse shaping. The effect of a plasma opening switch on diode behavior is considered.

  15. Effect of stance width on multidirectional postural responses

    NASA Technical Reports Server (NTRS)

    Henry, S. M.; Fung, J.; Horak, F. B.; Peterson, B. W. (Principal Investigator)

    2001-01-01

    The effect of stance width on postural responses to 12 different directions of surface translations was examined. Postural responses were characterized by recording 11 lower limb and trunk muscles, body kinematics, and forces exerted under each foot of 7 healthy subjects while they were subjected to horizontal surface translations in 12 different, randomly presented directions. A quasi-static approach of force analysis was done, examining force integrals in three different epochs (background, passive, and active periods). The latency and amplitude of muscle responses were quantified for each direction, and muscle tuning curves were used to determine the spatial activation patterns for each muscle. The results demonstrate that the horizontal force constraint exerted at the ground was lessened in the wide, compared with narrow, stance for humans, a similar finding to that reported by Macpherson for cats. Despite more trunk displacement in narrow stance, there were no significant changes in body center of mass (CoM) displacement due to large changes in center of pressure (CoP), especially in response to lateral translations. Electromyographic (EMG) magnitude decreased for all directions in wide stance, particularly for the more proximal muscles, whereas latencies remained the same from narrow to wide stance. Equilibrium control in narrow stance was more of an active postural strategy that included regulating the loading/unloading of the limbs and the direction of horizontal force vectors. In wide stance, equilibrium control relied more on an increase in passive stiffness resulting from changes in limb geometry. The selective latency modulation of the proximal muscles with translation direction suggests that the trunk was being actively controlled in all directions. The similar EMG latencies for both narrow and wide stance, with modulation of only the muscle activation magnitude as stance width changed, suggest that the same postural synergy was only slightly modified

  16. Measurement of dose-width product in panoramic dental radiology.

    PubMed

    Isoardi, P; Ropolo, R

    2003-02-01

    The National Radiological Protection Board has recommended the introduction of dose-width product (DWP) for the measurement of patient dose in panoramic dental radiology. The present work describes a method for measuring DWP using a pencil ionization chamber. The technique was tested on five panoramic dental units; the reproducibility of the method was 5.7%. In order to test the method, DWP was also assessed using thermoluminescent dosemeters and film. The results obtained agreed within 8.6% with those obtained using the pencil ionization chamber method. The proposed method appears to be simple and precise.

  17. The width of the plateaus of the quantum Hall effect

    NASA Astrophysics Data System (ADS)

    Groshev, Atanas; Scho¨n, Gerd

    1994-02-01

    We suggest that in high quality samples in the quantum Hall regime the interaction between localized states dominates over disorder effects. It leads to the formation of a Wigner crystal, which melts at a critical value ν c≈0.2 of the filling factor of the localized states. This leads to a finite width of the plateaus of the integer quantum Hall effect Δν=2ν c. This result describes well recent experimental data on single AlGaAs/GaAs heterojunctions (electron and hole gases) and double 2DEG systems.

  18. Excitation-energy dependence of the giant dipole resonance width

    NASA Astrophysics Data System (ADS)

    Enders, G.; Berg, F. D.; Hagel, K.; Kühn, W.; Metag, V.; Novotny, R.; Pfeiffer, M.; Schwalb, O.; Charity, R. J.; Gobbi, A.; Freifelder, R.; Henning, W.; Hildenbrand, K. D.; Holzmann, R.; Mayer, R. S.; Simon, R. S.; Wessels, J. P.; Casini, G.; Olmi, A.; Stefanini, A. A.

    1992-07-01

    High-energy γ rays have been measured in coincidence with heavy fragents in deeply inelastic reactions of 136Xe+48Ti at 18.5 MeV/nucleon. The giant dipole resonance (GDR) strength function is deduced from an analysis of the photon spectra within the statistical model. The GDR width Γ is studied as a function of the fragment excitation energy E*. A saturation at about Γ=10 MeV is observed for E*/A>=1.0 MeV/nucleon.

  19. Runway width effects in the visual approach to landing.

    PubMed

    Galanis, G; Jennings, A; Beckett, P

    2001-01-01

    The effect of changes in runway width on the perception of glide-slope has been the subject of extensive investigations. Despite considerable research, an explanation of this effect has been elusive. A mathematical model for glide-slope perception was published recently based on the premise that a desirable goal of perception is to form a perception with minimal uncertainty. One of the qualitative predictions of that model was that changes in the aspect ratio of the runway would affect the perceived glide-slope. In this article, the predictions of the model are quantified and are shown to be in close agreement with experimental results in the literature.

  20. Measurement of peak discharge at width contractions by indirect methods

    USGS Publications Warehouse

    Matthai, Howard Frederick

    1967-01-01

    This chapter describes procedures for measuring peak discharges using open-channel width contractions. Field and office procedures limited to this method are described. The discharge equation based on the continuity and energy equations between an approach cross section and the contracted section under a bridge or contraction is given. Contractions are classified into four geometric types. Discharge coefficients and computation procedures are given with a complete facsimile example of computation of a contracted-opening measurement. Additional procedures are given for multiple-opening contractions.

  1. {lambda}(1520) {yields} {lambda}{gamma} Radiative-Decay Width

    SciTech Connect

    Vavilov, D.V.; Antipov, Yu.M.; Artamonov, A.V.; Batarin, V.A.; Victorov, V.A.; Golovkin, S.V.; Gorin, Yu.P.; Eroshin, O.V.; Kozhevnikov, A.P.; Konstantinov, A.S.; Kubarovsky, V.P.; Kurshetsov, V.F.; Landsberg, L.G.; Leontiev, V.M.; Molchanov, V.V.; Mukhin, V.A.; Patalakha, D.I.; Petrenko, S.V.; Petrukhin, A.I.; Kolganov, V.Z.

    2005-03-01

    The radiative decay {lambda}(1520) {yields} {lambda}{gamma} was recorded in the exclusive reaction p + N {yields} {lambda}(1520)K{sup +} + N at the SPHINX facility. The branching ratio for this decay and the corresponding partial width were found to be, respectively, Br[{lambda}(1520) {yields} {lambda}{gamma}] = (1.02 {+-} 0.21) x 10{sup -2} and {gamma}[{lambda}(1520) {yields} {lambda}{gamma}] = 159 {+-} 35 keV (the quoted errors are purely statistical, the systematic errors being within 15%)

  2. What sets the line widths in tidal disruption events?

    NASA Astrophysics Data System (ADS)

    Roth, Nathaniel; Kasen, Daniel

    2017-01-01

    The optical and UV spectra of flares from the tidal disruption of stars by massive black holes (TDEs) vary greatly between individual events. In particular, the line widths can differ by at least a factor of five even for events with similar values inferred for the black hole mass. Additionally, the lines narrow over time in some events, and this detail has proven difficult to explain based on hydrodynamical modeling. We present radiative transfer calculations to help understand these aspects of line formation from TDEs, with a focus on the role of electron scattering in both static and outflowing reprocessing envelopes.

  3. Leptonic partial widths of the excited {psi} states

    SciTech Connect

    Mo, X. H.; Yuan, C. Z.; Wang, P.

    2010-10-01

    The resonance parameters of the excited {psi}-family resonances, namely, the {psi}(4040), {psi}(4160), and {psi}(4415), were determined by fitting the R values measured by experiments. It is found that the previously reported leptonic partial widths of these states were merely one possible solution among a four-fold ambiguity. By fitting the most precise experimental data on the R values measured by the BES collaboration, this work presents all four sets of solutions. These results may affect the interpretation of the charmonium and charmonium-like states above 4 GeV/c{sup 2}.

  4. On the width of Σ hypernuclei and Σ- atoms

    NASA Astrophysics Data System (ADS)

    Brockmann, R.; Oset, E.

    1982-12-01

    The self-energy of a Σ particle in symmetric nuclear matter is investigated by using a boson exchange model for the ΣN interaction. The imaginary part of the self-energy is shown to be strongly density dependent and has saturation properties around ϱ ≌ 0.7 ϱo. This peculiar feature allows our results to be in good agreement with the Σ atom data while simultaneously providing a width of about 5 Mev or smaller for all nuclei and different states. Permanent address: Departamento de Física Atómica y Nuclear, Facultad de Ciencias, Universidad de Salamanca, Salamanca, Spain.

  5. Total width of 125 GeV Higgs boson.

    PubMed

    Barger, Vernon; Ishida, Muneyuki; Keung, Wai-Yee

    2012-06-29

    By using the LHC and Tevatron measurements of the cross sections to various decay channels relative to the standard model Higgs boson, the total width of the putative 125 GeV Higgs boson is determined as 6.1(-2.9)(+7.7) MeV. We describe a way to estimate the branching fraction for the Higgs-boson decay to dark matter. We also discuss a no-go theorem for the γγ signal of the Higgs boson at the LHC.

  6. Scientific assessment of ozone depletion: 1991

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Over the past few years, there have been highly significant advances in the understanding of the impact of human activities on the Earth's stratospheric ozone layer and the influence of changes in chemical composition of the radiative balance of the climate system. Specifically, since the last international scientific review (1989), there have been five major advances: (1) global ozone decreases; (2) polar ozone; (3) ozone and industrial halocarbons; (4) ozone and climate relations; and (5) ozone depletion potentials (ODP's) and global warming potentials (GWP's). These topics and others are discussed.

  7. Ozone Depletion and Biologically Relevant Ultraviolet Radiation.

    NASA Astrophysics Data System (ADS)

    Zeng, Jun

    1995-01-01

    An atmospheric radiative transfer model is used to calculate surface spectral ultraviolet irradiance under cloud-free conditions, and compared with measurements made at Lauder, New Zealand (45^circ{S }, 170^circ{E}) before and after the eruption of Mt. Pinatubo, and including a snow-covered surface. The ratios of diffuse to direct irradiance depend critically on solar elevation, surface albedo, and aerosol extinction. Ozone changes have pronounced effects on the global UVB irradiance, but have only a minor effect on these ratios. The comparison suggests that the ultraviolet radiation exposure can be computed with confidence for clear sky conditions, if the appropriate atmospheric pressure and temperature profiles, ozonesonde data, surface albedo, and aerosol optical properties are available. The total ozone abundances are derived by using ground-based UV irradiance measurements and compared with TOMS in Antarctica and the Arctic from 1990 to 1994. The comparisons show that they are generally in good agreement. Possible reasons for the discrepancies between the two methods are discussed. The equivalent cloud optical depths are also inferred from these data. Ozone depletion can also increase the penetration of ultraviolet radiation into the aquatic system. A coupled atmosphere-ocean radiative transfer model is used to investigate the effect of ozone depletion on UV penetration through the atmosphere and into the underlying water column. Comparisons between model computations and in situ measurements of irradiances made in Antarctic water show good agreement in the UV spectral range between 300 and 350 nm. The ratio of UVB (280-320 nm) to total (280-700 nm) irradiance also compared well. For a given ozone reduction the largest relative increase of UVB radiation arriving at the surface and penetrating to various depths in the ocean occurs at large solar zenith angles. At high latitudes the most pronounced increase in UVB exposure due to an ozone depletion occurs in the

  8. Depletion of the Outer Asteroid Belt

    NASA Technical Reports Server (NTRS)

    Liou, Jer-Chyi; Malhotra, Renu

    1997-01-01

    During the early history of the solar system, it is likely that the outer planets changed their distance from the sun, and hence, their influence on the asteroid belt evolved with time. The gravitational influence of Jupiter and Saturn on the orbital evolution of asteroids in the outer asteroid belt was calculated. The results show that the sweeping of mean motion resonances associated with planetary migration efficiently destabilizes orbits in the outer asteroid belt on a time scale of 10 million years. This mechanism provides an explanation for the observed depletion of asteroids in that region.

  9. Ozone depletion: implications for the veterinarian.

    PubMed

    Kopecky, K E

    1978-09-15

    Man has inadvertently modified the stratosphere. There is a good possibility that the ozone layer is being depleted by the use of jet aircraft (SST), chlorofluoromethane propellants, and nitrogen fertilizers. Under unpolluted conditions, the production of ozone equals its destruction. By man's intervention, however, the destruction may exceed the production. The potential outcome is increased intensity of solar ultraviolet (280-400 nm) radiation and penetration to the earth's surface of previously absorbed wavelengths below about 280 nm. The increased ultraviolet radiation would increase the likelihood of skin cancer in man and ocular squamous cell carcinoma in cattle. The climate also might be modified, possibly in an undesirable way.

  10. Depletion of the Outer Asteroid Belt

    PubMed

    Liou; Malhotra

    1997-01-17

    During the early history of the solar system, it is likely that the outer planets changed their distance from the sun, and hence, their influence on the asteroid belt evolved with time. The gravitational influence of Jupiter and Saturn on the orbital evolution of asteroids in the outer asteroid belt was calculated. The results show that the sweeping of mean motion resonances associated with planetary migration efficiently destabilizes orbits in the outer asteroid belt on a time scale of 10 million years. This mechanism provides an explanation for the observed depletion of asteroids in that region.

  11. Capstone Depleted Uranium Aerosols: Generation and Characterization

    SciTech Connect

    Parkhurst, MaryAnn; Szrom, Fran; Guilmette, Ray; Holmes, Tom; Cheng, Yung-Sung; Kenoyer, Judson L.; Collins, John W.; Sanderson, T. Ellory; Fliszar, Richard W.; Gold, Kenneth; Beckman, John C.; Long, Julie

    2004-10-19

    In a study designed to provide an improved scientific basis for assessing possible health effects from inhaling depleted uranium (DU) aerosols, a series of DU penetrators was fired at an Abrams tank and a Bradley fighting vehicle. A robust sampling system was designed to collect aerosols in this difficult environment and continuously monitor the sampler flow rates. Aerosols collected were analyzed for uranium concentration and particle size distribution as a function of time. They were also analyzed for uranium oxide phases, particle morphology, and dissolution in vitro. The resulting data provide input useful in human health risk assessments.

  12. Correlation between cosmic rays and ozone depletion.

    PubMed

    Lu, Q-B

    2009-03-20

    This Letter reports reliable satellite data in the period of 1980-2007 covering two full 11-yr cosmic ray (CR) cycles, clearly showing the correlation between CRs and ozone depletion, especially the polar ozone loss (hole) over Antarctica. The results provide strong evidence of the physical mechanism that the CR-driven electron-induced reaction of halogenated molecules plays the dominant role in causing the ozone hole. Moreover, this mechanism predicts one of the severest ozone losses in 2008-2009 and probably another large hole around 2019-2020, according to the 11-yr CR cycle.

  13. Polar Dunes Resolved by the Mars Orbiter Laser Altimeter Gridded Topography and Pulse Widths

    NASA Technical Reports Server (NTRS)

    Neumann, Gregory A.

    2003-01-01

    The Mars Orbiter Laser Altimeter (MOLA) polar data have been refined to the extent that many features poorly imaged by Viking Orbiters are now resolved in densely gridded altimetry. Individual linear polar dunes with spacings of 0.5 km or more can be seen as well as sparsely distributed and partially mantled dunes. The refined altimetry will enable measurements of the extent and possibly volume of the north polar ergs. MOLA pulse widths have been recalibrated using inflight data, and a robust algorithm applied to solve for the surface optical impulse response. It shows the surface root-mean-square (RMS) roughness at the 75-m-diameter MOLA footprint scale, together with a geological map. While the roughness is of vital interest for landing site safety studies, a variety of geomorphological studies may also be performed. Pulse widths corrected for regional slope clearly delineate the extent of the polar dunes. The MOLA PEDR profile data have now been re-released in their entirety (Version L). The final Mission Experiment Gridded Data Records (MEGDR's) are now provided at up to 128 pixels per degree globally. Densities as high as 512 pixels per degree are available in a polar stereographic projection. A large computational effort has been expended in improving the accuracy of the MOLA altimetry themselves, both in improved orbital modeling and in after-the-fact adjustment of tracks to improve their registration at crossovers. The current release adopts the IAU2000 rotation model and cartographic frame recommended by the Mars Cartography Working Group. Adoption of the current standard will allow registration of images and profiles globally with an uncertainty of less than 100 m. The MOLA detector is still operational and is currently collecting radiometric data at 1064 nm. Seasonal images of the reflectivity of the polar caps can be generated with a resolution of about 300 m per pixel.

  14. Polar Dunes Resolved by the Mars Orbiter Laser Altimeter Gridded Topography and Pulse Widths

    NASA Technical Reports Server (NTRS)

    Neumann, Gregory A.

    2003-01-01

    The Mars Orbiter Laser Altimeter (MOLA) polar data have been refined to the extent that many features poorly imaged by Viking Orbiters are now resolved in densely gridded altimetry. Individual linear polar dunes with spacings of 0.5 km or more can be seen as well as sparsely distributed and partially mantled dunes. The refined altimetry will enable measurements of the extent and possibly volume of the north polar ergs. MOLA pulse widths have been recalibrated using inflight data, and a robust algorithm applied to solve for the surface optical impulse response. It shows the surface root-mean-square (RMS) roughness at the 75-m-diameter MOLA footprint scale, together with a geological map. While the roughness is of vital interest for landing site safety studies, a variety of geomorphological studies may also be performed. Pulse widths corrected for regional slope clearly delineate the extent of the polar dunes. The MOLA PEDR profile data have now been re-released in their entirety (Version L). The final Mission Experiment Gridded Data Records (MEGDR's) are now provided at up to 128 pixels per degree globally. Densities as high as 512 pixels per degree are available in a polar stereographic projection. A large computational effort has been expended in improving the accuracy of the MOLA altimetry themselves, both in improved orbital modeling and in after-the-fact adjustment of tracks to improve their registration at crossovers. The current release adopts the IAU2000 rotation model and cartographic frame recommended by the Mars Cartography Working Group. Adoption of the current standard will allow registration of images and profiles globally with an uncertainty of less than 100 m. The MOLA detector is still operational and is currently collecting radiometric data at 1064 nm. Seasonal images of the reflectivity of the polar caps can be generated with a resolution of about 300 m per pixel.

  15. Within-person variability in men’s facial width-to-height ratio

    PubMed Central

    2016-01-01

    Background. In recent years, researchers have investigated the relationship between facial width-to-height ratio (FWHR) and a variety of threat and dominance behaviours. The majority of methods involved measuring FWHR from 2D photographs of faces. However, individuals can vary dramatically in their appearance across images, which poses an obvious problem for reliable FWHR measurement. Methods. I compared the effect sizes due to the differences between images taken with unconstrained camera parameters (Studies 1 and 2) or varied facial expressions (Study 3) to the effect size due to identity, i.e., the differences between people. In Study 1, images of Hollywood actors were collected from film screenshots, providing the least amount of experimental control. In Study 2, controlled photographs, which only varied in focal length and distance to camera, were analysed. In Study 3, images of different facial expressions, taken in controlled conditions, were measured. Results. Analyses revealed that simply varying the focal length and distance between the camera and face had a relatively small effect on FWHR, and therefore may prove less of a problem if uncontrolled in study designs. In contrast, when all camera parameters (including the camera itself) are allowed to vary, the effect size due to identity was greater than the effect of image selection, but the ranking of the identities was significantly altered by the particular image used. Finally, I found significant changes to FWHR when people posed with four of seven emotional expressions in comparison with neutral, and the effect size due to expression was larger than differences due to identity. Discussion. The results of these three studies demonstrate that even when head pose is limited to forward facing, changes to the camera parameters and a person’s facial expression have sizable effects on FWHR measurement. Therefore, analysing images that fail to constrain some of these variables can lead to noisy and

  16. Optical study of a-plane InGaN/GaN multiple quantum wells with different well widths grown by metal-organic chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Ko, T. S.; Lu, T. C.; Wang, T. C.; Chen, J. R.; Gao, R. C.; Lo, M. H.; Kuo, H. C.; Wang, S. C.; Shen, J. L.

    2008-11-01

    a-plane InGaN/GaN multiple quantum wells of different widths ranging from 3 to 12 nm grown on r-plane sapphire by metal-organic chemical vapor deposition were investigated. The peak emission intensity of the photoluminescence (PL) reveals a decreasing trend as the well width increases from 3 to 12 nm. Low temperature (9 K) time-resolved PL (TRPL) study shows that the sample with 3-nm-thick wells has the best optical property with a fastest exciton decay time of 0.57 ns. The results of cathodoluminescence and micro-PL scanning images for samples of different well widths further verify that the more uniform and stronger luminescence intensity distribution are observed for the samples of thinner quantum wells. In addition, more effective capturing of excitons due to larger localization energy Eloc and shorter radiative lifetime of localized excitons are observed in thinner well width samples in the temperature dependent TRPL.

  17. Simulations and observations of plasma depletion, ion composition, and airglow emissions in two auroral ionospheric depletion experiments

    NASA Technical Reports Server (NTRS)

    Yau, A. W.; Whalen, B. A.; Harris, F. R.; Gattinger, R. L.; Pongratz, M. B.

    1985-01-01

    Observations of plasma depletion, ion composition modification, and airglow emissions in the Waterhole experiments are presented. The detailed ion chemistry and airglow emission processes related to the ionospheric hole formation in the experiment are examined, and observations are compared with computer simulation results. The latter indicate that the overall depletion rates in different parts of the depletion region are governed by different parameters.

  18. Decline and depletion rates of oil production: a comprehensive investigation.

    PubMed

    Höök, Mikael; Davidsson, Simon; Johansson, Sheshti; Tang, Xu

    2014-01-13

    Two of the most fundamental concepts in the current debate about future oil supply are oilfield decline rates and depletion rates. These concepts are related, but not identical. This paper clarifies the definitions of these concepts, summarizes the underlying theory and empirically estimates decline and depletion rates for different categories of oilfield. A database of 880 post-peak fields is analysed to determine typical depletion levels, depletion rates and decline rates. This demonstrates that the size of oilfields has a significant influence on decline and depletion rates, with generally high values for small fields and comparatively low values for larger fields. These empirical findings have important implications for oil supply forecasting.

  19. Ego depletion results in an increase in spontaneous false memories.

    PubMed

    Otgaar, Henry; Alberts, Hugo; Cuppens, Lesly

    2012-12-01

    The primary aim of the current study was to examine whether depleted cognitive resources might have ramifications for the formation of neutral and negative spontaneous false memories. To examine this, participants received neutral and negative Deese/Roediger-McDermott false memory wordlists. Also, for half of the participants, cognitive resources were depleted by use of an ego depletion manipulation (solving difficult calculations while being interfered with auditory noise). Our chief finding was that depleted cognitive resources made participants more vulnerable for the production of false memories. Our results shed light on how depleted cognitive resources affect neutral and negative correct and errant memories.

  20. Longitudinal wave motion in width-constrained auxetic plates

    NASA Astrophysics Data System (ADS)

    Lim, Teik-Cheng

    2016-05-01

    This paper investigates the longitudinal wave velocity in auxetic plates in comparison to conventional ones, in which the plate is constrained from motion in the width direction. By taking into account the thickness change of the plate and its corresponding change in density, the developed wave velocity is casted not only as a function of Young’s modulus and density, but also in terms of Poisson’s ratio and longitudinal strain. Results show that density and thickness variations compensate for one another when the Poisson’s ratio is positive, but add up when the Poisson’s ratio is negative. Results also reveal that the classical model of longitudinal wave velocity for the plate is accurate when the Poisson’s ratio is about 1/3; at this Poisson’s ratio the influence from density and thickness variations cancel each other. Comparison between the current corrected model and the density-corrected Rayleigh-Lamb model reveals a number of consistent trends, while the discrepancies are elucidated. If the plate material possesses a negative Poisson’s ratio, the deviation of the actual wave velocity from the classical model becomes significant; auxeticity suppresses and enhances the wave velocity in compressive and tensile impacts, respectively. Hence the use of the corrected model is proposed when predicting longitudinal waves in width-constrained auxetic plates, and auxetic materials can be harnessed for effectively controlling wave velocities in thin-walled structures.

  1. Urban street speed related to width and functional class

    SciTech Connect

    Gattis, J.L.; Watts, A.

    1999-05-01

    In recent years, land development professionals from various disciplines have advocated narrowing city streets as a means to slow speeds and improve the urban environment. This paper reports the findings of a study of relationships among urban street function (i.e., arterial versus local traffic), width, and resulting speed. Crash data for the roadways studied also were considered. The objective was to determine if the wider streets did in fact have more objectionable traits (e.g., higher speeds or crash rates) than did the narrower streets, taking street function into account. Six two-lane streets in a small city were considered; the predominant focus of the study was an old neighborhood with streets in a grid layout. The findings suggest that street width may play a small role in vehicle speed, but other factors such as trip function may be more significant determinants of the average and 85th percentile through vehicle speeds. From this study, one also can infer the need to segregate traits of through vehicles from local vehicles when collecting speed data for the purpose of contrasting the behaviors on various streets.

  2. Direct top-quark width measurement at CDF.

    PubMed

    Aaltonen, T; Álvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Apollinari, G; Appel, J A; Apresyan, A; Arisawa, T; Artikov, A; Asaadi, J; Ashmanskas, W; Auerbach, B; Aurisano, A; Azfar, F; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Barria, P; Bartos, P; Bauce, M; Bauer, G; Bedeschi, F; Beecher, D; Behari, S; Bellettini, G; Bellinger, J; Benjamin, D; Beretvas, A; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Bland, K R; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Brisuda, A; Bromberg, C; Brucken, E; Bucciantonio, M; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Cabrera, S; Calancha, C; Camarda, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carls, B; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavaliere, V; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Corbo, M; Cordelli, M; Cox, C A; Cox, D J; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Dagenhart, D; d'Ascenzo, N; Datta, M; de Barbaro, P; De Cecco, S; De Lorenzo, G; Dell'Orso, M; Deluca, C; Demortier, L; Deng, J; Deninno, M; Devoto, F; d'Errico, M; Di Canto, A; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Dorigo, T; Ebina, K; Elagin, A; Eppig, A; Erbacher, R; Errede, D; Errede, S; Ershaidat, N; Eusebi, R; Fang, H C; Farrington, S; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Frank, M J; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garfinkel, A F; Garosi, P; Gerberich, H; Gerchtein, E; Giagu, S; Giakoumopoulou, V; Giannetti, P; Gibson, K; Ginsburg, C M; Giokaris, N; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldin, D; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, S R; Halkiadakis, E; Hamaguchi, A; Han, J Y; Happacher, F; Hara, K; Hare, D; Hare, M; Harr, R F; Hatakeyama, K; Hays, C; Heck, M; Heinrich, J; Herndon, M; Hewamanage, S; Hidas, D; Hocker, A; Hopkins, W; Horn, D; Hou, S; Hughes, R E; Hurwitz, M; Husemann, U; Hussain, N; Hussein, M; Huston, J; Introzzi, G; Iori, M; Ivanov, A; James, E; Jang, D; Jayatilaka, B; Jeon, E J; Jha, M K; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Ketchum, W; Keung, J; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, H W; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Klimenko, S; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kreps, M; Kroll, J; Krop, D; Krumnack, N; Kruse, M; Krutelyov, V; Kuhr, T; Kurata, M; Kwang, S; Laasanen, A T; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, E; Lee, H S; Lee, J S; Lee, S W; Leo, S; Leone, S; Lewis, J D; Lin, C-J; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, C; Liu, Q; Liu, T; Lockwitz, S; Lockyer, N S; Loginov, A; Lucchesi, D; Lueck, J; Lujan, P; Lukens, P; Lungu, G; Lys, J; Lysak, R; Madrak, R; Maeshima, K; Makhoul, K; Maksimovic, P; Malik, S; Manca, G; Manousakis-Katsikakis, A; Margaroli, F; Marino, C; Martínez, M; Martínez-Ballarín, R; Mastrandrea, P; Mathis, M; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzione, A; Mesropian, C; Miao, T; Mietlicki, D; Mitra, A; Miyake, H; Moed, S; Moggi, N; Mondragon, M N; Moon, C S; Moore, R; Morello, M J; Morlock, J; Movilla Fernandez, P; Mukherjee, A; Muller, Th; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Naganoma, J; Nakano, I; Napier, A; Nett, J; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oakes, L; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Orava, R; Ortolan, L; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Paramonov, A A; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Pianori, E; Pilot, J; Pitts, K; Plager, C; Pondrom, L; Potamianos, K; Poukhov, O; Prokoshin, F; Pronko, A; Ptohos, F; Pueschel, E; Punzi, G; Pursley, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Renton, P; Rescigno, M; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rodriguez, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Ruffini, F; Ruiz, A; Russ, J; Rusu, V; Safonov, A; Sakumoto, W K; Santi, L; Sartori, L; Sato, K; Saveliev, V; Savoy-Navarro, A; Schlabach, P; Schmidt, A; Schmidt, E E; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sforza, F; Sfyrla, A; Shalhout, S Z; Shears, T; Shepard, P F; Shimojima, M; Shiraishi, S; Shochet, M; Shreyber, I; Simonenko, A; Sinervo, P; Sissakian, A; Sliwa, K; Smith, J R; Snider, F D; Soha, A; Somalwar, S; Sorin, V; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Strycker, G L; Sudo, Y; Sukhanov, A; Suslov, I; Takemasa, K; Takeuchi, Y; Tang, J; Tecchio, M; Teng, P K; Thom, J; Thome, J; Thompson, G A; Thomson, E; Ttito-Guzmán, P; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Totaro, P; Trovato, M; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Vidal, M; Vila, I; Vilar, R; Vogel, M; Volpi, G; Wagner, P; Wagner, R L; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Wilbur, S; Wick, F; Williams, H H; Wilson, J S; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, H; Wright, T; Wu, X; Wu, Z; Yamamoto, K; Yamaoka, J; Yang, T; Yang, U K; Yang, Y C; Yao, W-M; Yeh, G P; Yi, K; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanetti, A; Zeng, Y; Zucchelli, S

    2010-12-03

    We present a measurement of the top-quark width in the lepton+jets decay channel of tt events produced in p p collisions at Fermilab's Tevatron collider and collected by the CDF II detector. From a data sample corresponding to 4.3 fb(-1) of integrated luminosity, we identify 756 candidate events. The top-quark mass and the mass of the hadronically decaying W boson that comes from the top-quark decay are reconstructed for each event and compared with templates of different top-quark widths (Γ(t)) and deviations from nominal jet energy scale (Δ(JES)) to perform a simultaneous fit for both parameters, where Δ(JES) is used for the in situ calibration of the jet energy scale. By applying a Feldman-Cousins approach, we establish an upper limit at 95% confidence level (CL) of Γ(t) <7.6 GeV and a two-sided 68% CL interval of 0.3 GeV <Γ(t) <4.4  GeV for a top-quark mass of 172.5 GeV/c(2), which are consistent with the standard model prediction.

  3. Fractal Reference Signals in Pulse-Width Modulation

    NASA Technical Reports Server (NTRS)

    Lurie, Boris; Lurie, Helen

    2005-01-01

    A report proposes the use of waveforms having fractal shapes reminiscent of sawteeth (in contradistinction to conventional regular sawtooth waveforms) as reference signals for pulse-width modulation in control systems for thrusters of spacecraft flying in formation. Fractal reference signals may also be attractive in some terrestrial control systems - especially those in which pulse-width modulation is used for precise control of electric motors. The report asserts that the use of fractal reference signals would enable the synchronous control of several variables of a spacecraft formation, such that consumption of propellant would be minimized, intervals between thruster firings would be long (as preferred for performing scientific observations), and delays in controlling large-thrust maneuvers for retargeting would be minimized. The report further asserts that whereas different controllers would be needed for different modes of operation if conventional pulsewidth modulation were used, the use of fractal reference signals would enable the same controller to function nearly optimally in all regimes of operation, so that only this one controller would be needed.

  4. The d*(2380) dibaryon resonance width and decay branching ratios

    NASA Astrophysics Data System (ADS)

    Gal, A.

    2017-06-01

    Attempts to reproduce theoretically the width Γd* = 80 ± 10 MeV of the I (JP) = 0 (3+)d*(2380) dibaryon resonance established by the WASA-at-COSY Collaboration are discussed. The validity of associating the d*(2380) in quark-based models exclusively with a tightly bound ΔΔ configuration is questioned. The d*(2380) width and decay branching ratios into NNππ, NNπ and NN final states are studied within the Gal-Garcilazo hadronic model in which the d*(2380) is a πNΔ resonance embedded in the NNππ continuum some 80 MeV below the ΔΔ threshold. In particular, predictions are made for the branching ratios of the unobserved yet d* (2380) → NNπ decays which are suppressed in a purely-ΔΔ dibaryon model. A possible connection of the ABC effect observed in the pn →d* → dπ0π0 resonance reaction to the d*(2380) dibaryon is noted.

  5. Zero-width resonances in intense-field molecular photodissociation

    SciTech Connect

    Atabek, Osman; Lefebvre, Roland; Gadea, Florent Xavier

    2006-12-15

    We provide additional evidence for the existence of zero-width resonances in the intense-field photodissociation of H{sub 2}{sup +}. In a previous investigation [Atabek, Chrysos, and Lefebvre, Phys. Rev. A 49, R8 (1994)] the situation, in a two-channel dressed picture, corresponded to a diabatic crossing point classically reachable in both adiabatic potentials. A semiclassical explanation could be modeled after that developed for predissociation in the intermediate-coupling regime. At higher frequencies the crossing point lies between the two turning points. A numerical study shows that zero-width resonances exist also in such a case. An extension of the semiclassical approach provides an explanation for the occurrence of these resonances. It is shown that they survive even when going to a multichannel description. The associated wave functions and probability densities are studied: they are very similar to those of the upper adiabatic potential, with a minor component in the lower adiabatic channel. Some conditions for the production of such long-lived dressed molecular species are stated.

  6. Reflectionless wave dynamics in channels of variable depth and width

    NASA Astrophysics Data System (ADS)

    Pelinovsky, Efim; Didenkulova, Ira; Shurgalina, Ekaterina

    2017-04-01

    In this work we discuss long wave dynamics in rectangular channels of variable depth and width. Demonstrated, that for conditions of "self-consistent channel" when Bc = const (B is a channel width, and c is a celerity), the wave propagates without inner reflection from the channel bottom and walls even if the function c(x) is arbitrary. It is shown, in the framework of the linear shallow-water theory, that the temporal shape of the travelling wave does not change with the distance; its amplitude and duration are constant. However, the spatial shape of the wave varies due to the change in celerity along the channel. In the framework of the nonlinear shallow-water theory, it is shown that the travelling wave deforms while the inner reflection from the channel bottom and walls is still absent. In this case dispersive effects lead to a disintegration of the initial wave into solitons. This process is studied in detail. Such unusual waves may propagate over long distances without loss of energy.

  7. Neutron decay widths of excited states of {sup 11}Be

    SciTech Connect

    Haigh, P. J.; Freer, M.; Ashwood, N. I.; Bloxham, T.; Curtis, N.; McEwan, P.; Bohlen, H. G.; Dorsch, T.; Kokalova, Tz.; Schulz, Ch.; Wheldon, C.

    2009-01-15

    The two-neutron transfer reaction {sup 9}Be({sup 16}O, {sup 14}O){sup 11}Be[{sup 10}Be +n] has been used to measure the branching ratios for the neutron decay of excited states of {sup 11}Be. The {sup 14}O ejectile was detected by a Q3D spectrometer at forward angles. The energies and angles of the {sup 10}Be fragments of the decaying {sup 11}Be* recoil were measured in coincidence with the {sup 14}O ejectile using a double-sided silicon strip detector array at backward angles. This enabled a kinematic reconstruction of the reaction to be performed. Theoretical decay branch ratios were calculated using barrier penetrability factors and were compared to the measured ratios to provide information on the relative reduced widths of the states. The decay widths have been used to link states in {sup 11}Be with a common structure and structurally to states in the daughter nucleus {sup 10}Be. The 3/2{sup -} 8.82-MeV state was identified as a candidate for a molecular band head.

  8. Baryon Masses and Hadronic Decay Widths with Explicit Pionic Contributions

    NASA Astrophysics Data System (ADS)

    Schmidt, R. A.; Canton, L.; Plessas, W.; Schweiger, W.

    2017-03-01

    We report results from studies of baryon ground and resonant states by taking explicit mesonic degrees of freedom into account. We are following a relativistic coupled-channels approach relying on a Poincaré-invariant mass operator in matrix form. Generally, it corresponds to a bare particle that is coupled to a number of further mesonic channels. Here we present results, where the bare particle is either a bare nucleon or a bare Delta coupled to pion-nucleon and pion-Delta channels, respectively. For the pion-baryon vertices we employ coupling constants and form factors from different models in the literature. From the mass-operator eigenvalue equation we obtain the pion-dressing effects on the nucleon mass as well as the mass and pion-decay width of the Delta. The dressed masses become smaller than the bare ones, and a finite width of the Delta is naturally generated. The results are relevant for the construction of constituent-quark models for baryons, which have so far not included explicit mesonic degrees of freedom, but have rather relied on three-quark configurations only.

  9. A New Method for Line Width Roughness Mitigation

    NASA Astrophysics Data System (ADS)

    Mayya, K. Subramanya; Yool, Kang; Kim, Hochul; Cho, Han-Ku

    2011-06-01

    Demands of the continuous downscaling of device size impose stringent requirements on the RLS trade-off (R: resolution, L: line width roughness and S: sensitivity). Among the above, line width roughness (LWR) has to be controlled below 10% of critical dimensions (CD). While significant improvement in R&S was achieved, LWR has been relatively high for extreme ultra-violet lithography resists. Herein, we provide a new method for LWR mitigation that overcomes several shortcomings of previously known methods. Our new method is based on a double development method wherein, a polymeric solution in developer is coated on to the patterned surface. The wafer is then subjected to the standard development step during which LWR improvement is affected. In this paper we discuss the hypothesis of our method and provide relevant data to understand the conditions under which LWR improvement is observed. Effect of polymer/developer concentration ratio, solid content and bake temperatures will be discussed. Also, our method will be compared with currently available methods for LWR improvement on pattern transfer.

  10. Multifractal diffusion entropy analysis: Optimal bin width of probability histograms

    NASA Astrophysics Data System (ADS)

    Jizba, Petr; Korbel, Jan

    2014-11-01

    In the framework of Multifractal Diffusion Entropy Analysis we propose a method for choosing an optimal bin-width in histograms generated from underlying probability distributions of interest. The method presented uses techniques of Rényi’s entropy and the mean squared error analysis to discuss the conditions under which the error in the multifractal spectrum estimation is minimal. We illustrate the utility of our approach by focusing on a scaling behavior of financial time series. In particular, we analyze the S&P500 stock index as sampled at a daily rate in the time period 1950-2013. In order to demonstrate a strength of the method proposed we compare the multifractal δ-spectrum for various bin-widths and show the robustness of the method, especially for large values of q. For such values, other methods in use, e.g., those based on moment estimation, tend to fail for heavy-tailed data or data with long correlations. Connection between the δ-spectrum and Rényi’s q parameter is also discussed and elucidated on a simple example of multiscale time series.

  11. Origin of multiple band gap values in single width nanoribbons

    PubMed Central

    Goyal, Deepika; Kumar, Shailesh; Shukla, Alok; Kumar, Rakesh

    2016-01-01

    Deterministic band gap in quasi-one-dimensional nanoribbons is prerequisite for their integrated functionalities in high performance molecular-electronics based devices. However, multiple band gaps commonly observed in graphene nanoribbons of the same width, fabricated in same slot of experiments, remain unresolved, and raise a critical concern over scalable production of pristine and/or hetero-structure nanoribbons with deterministic properties and functionalities for plethora of applications. Here, we show that a modification in the depth of potential wells in the periodic direction of a supercell on relative shifting of passivating atoms at the edges is the origin of multiple band gap values in nanoribbons of the same width in a crystallographic orientation, although they carry practically the same ground state energy. The results are similar when calculations are extended from planar graphene to buckled silicene nanoribbons. Thus, the findings facilitate tuning of the electronic properties of quasi-one-dimensional materials such as bio-molecular chains, organic and inorganic nanoribbons by performing edge engineering. PMID:27808172

  12. Origin of multiple band gap values in single width nanoribbons

    NASA Astrophysics Data System (ADS)

    Goyal, Deepika; Kumar, Shailesh; Shukla, Alok; Kumar, Rakesh

    2016-11-01

    Deterministic band gap in quasi-one-dimensional nanoribbons is prerequisite for their integrated functionalities in high performance molecular-electronics based devices. However, multiple band gaps commonly observed in graphene nanoribbons of the same width, fabricated in same slot of experiments, remain unresolved, and raise a critical concern over scalable production of pristine and/or hetero-structure nanoribbons with deterministic properties and functionalities for plethora of applications. Here, we show that a modification in the depth of potential wells in the periodic direction of a supercell on relative shifting of passivating atoms at the edges is the origin of multiple band gap values in nanoribbons of the same width in a crystallographic orientation, although they carry practically the same ground state energy. The results are similar when calculations are extended from planar graphene to buckled silicene nanoribbons. Thus, the findings facilitate tuning of the electronic properties of quasi-one-dimensional materials such as bio-molecular chains, organic and inorganic nanoribbons by performing edge engineering.

  13. KOLMOGOROV'S (n,\\,\\delta)-WIDTHS OF SPACES OF SMOOTH FUNCTIONS

    NASA Astrophysics Data System (ADS)

    Maĭorov, V. E.

    1994-02-01

    Kolmogorov's (n,\\,\\delta)-widths of the Sobolev spaces W_2^r, equipped with a Gaussian probability measure \\mu, are studied in the metric of L_q: \\displaystyle d_{n,\\delta}(W_2^r,\\,\\mu,\\,L_q)=\\inf_{G\\subset W_2^r}d_n(W_2^r\\setminus G,\\,L_q),where d_n(K,\\, L_q) is Kolmogorov's n-width of the set K in the space L_q, and the infimum is taken over all possible subsets G\\subset W_2^r with measure \\mu(G)\\leq\\delta, 0\\leq\\delta\\leq1. The asymptotic equality \\displaystyle d_{n,\\delta}(W_2^r,\\,\\mu,\\,L_q)\\asymp n^{-r-\\varepsilon}\\sqrt{1+\\frac1n\\ln\\frac1\\delta}with respect to n and \\delta is obtained, where 1\\leq q\\leq\\infty and \\varepsilon>0 is an arbitrary number depending only on the measure \\mu.Bibliography: 20 titles.

  14. Determination of the width of the top quark

    SciTech Connect

    Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Abolins, Maris A.; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D.; Alkhazov, Georgiy D.; Alton, Andrew K.; Alverson, George O.; Alves, Gilvan Augusto; /Rio de Janeiro, CBPF /Nijmegen U.

    2010-09-01

    We extract the total width of the top quark, {Lambda}{sub t}, from the partial decay width {Lambda}(t {yields} Wb) measured using the t-channel cross section for single top quark production and from the branching fraction B(t {yields} Wb) measured in t{bar t} events using up to 2.3 fb{sup -1} of integrated luminosity collected by the D0 Collaboration at the Tevatron p{bar p} Collider. The result is {Lambda}{sub t} = 1.99{sub -0.55}{sup +0.69} GeV, which translates to a top-quark lifetime of {tau}{sub t} = (3.3{sub -0.9}{sup +1.3}) x 10{sup -25} s. Assuming a high mass fourth generation b{prime} quark and unitarity of the four-generation quark-mixing matrix, we set the first upper limit on |V{sub tb{prime}}| < 0.63 at 95% C.L.

  15. The precursory fault width formation of large earthquakes

    NASA Astrophysics Data System (ADS)

    Takeda, Fumihide; Takeo, Makoto

    2010-03-01

    We collect earthquake (EQ) events for a region of about 5 degree mesh from a focus catalog of Japan with a regionally dependent magnitude window of M >= 3-3.5. The time history of the events draws a zigzagged trajectory in a five dimensional space of EQ epicenter, focal depth (DEP), inter-event interval (INT), and magnitude (MAG). Its components are the time series of the EQ source parameters for which time is the chronological event index. Each series has long-term memory and evidence of deterministic chaos. We thus use physical wavelets (P-Ws) to find the process producing large EQs. The P-Ws convert the moving-average of each series, its first and second order differences at any interval into the displacement, velocity and acceleration (A) in selective frequency region, respectively. The process starts with two unique different triple phase couplings of A on source parameters DEP, INT, and MAG, precursory to every large EQ's (M > about 6) throughout Japan. Each coupling then creates a linear DEP variation (W) on its series, which becomes comparable to the fault width of large EQ's. It suggests that the variation exerts the corresponding shear stress on a local plane in Earth's crust to form the fault plane of width W, rupturing a large EQ.

  16. Width of the chaotic layer: maxima due to marginal resonances.

    PubMed

    Shevchenko, Ivan I

    2012-06-01

    Modern theoretical methods for estimating the width of the chaotic layer in the presence of prominent marginal resonances are considered in the perturbed pendulum model of nonlinear resonance. The fields of applicability of these methods are explicitly and precisely formulated. The comparative accuracy is investigated in massive and long-run numerical experiments. It is shown that the methods are naturally subdivided in classes applicable for adiabatic and nonadiabatic cases of perturbation. It is explicitly shown that the pendulum approximation of marginal resonance works well in the nonadiabatic case. In this case, the role of marginal resonances in determining the total layer width is demonstrated to diminish with increasing main parameter λ (equal to the ratio of the perturbation frequency to the frequency of small-amplitude phase oscillations on the resonance). Solely the "bending effect" is important in determining the total amplitude of the energy deviations of the near-separatrix motion at λ≳7. In the adiabatic case, it is demonstrated that the geometrical form of the separatrix cell can be described analytically quite easily by means of using a specific representation of the separatrix map. It is shown that the nonadiabatic (and, to some extent, intermediary) case is most actual, in comparison with the adiabatic one, for the physical or technical applications that concern the energy jumps in the near-separatrix chaotic motion.

  17. Bang Time and Burn Width Analysis at the NIF

    NASA Astrophysics Data System (ADS)

    Grafil, E.; Herrmann, H. W.; Stoeffl, W.; Kim, Y.; Hoffman, N. M.; Young, C. S.; Mack, J. M.; Watts, P. W.; Carpenter, A. C.; Church, J.; Bernstein, L.; Liebman, J.; Rubery, M.; Horsefield, C. J.; Miller, E. K.

    2011-10-01

    The time of peak fusion reactivity with respect to the impingement of laser light on an Inertial Confinement Fusion capsule is known as Nuclear Bang Time (BT). The width of this peak is the Nuclear Burn Width (BW). Accurately measuring BT & BW is essential for constraining hydrodynamic simulations as it is a measure of energy coupling to the target. BT & BW measurements have been performed using a variety of instruments at the National Ignition Facility (NIF). The Gamma Reaction History (GRH) diagnostic is designed to measure fusion gamma-rays in determining BT & BW to within 30 ps precision and accuracy. The GRH consists of four Gas Cherenkov Detectors having variable energy-thresholding capability. For BT measurements, the threshold is typically set >8 MeV so as to isolate DT fusion gamma-rays at 16.75 MeV while thresholding out the lower energy (n,n') gammas. The GRH experimental setup, data and comparison to BT & BW from other diagnostics methods are presented. U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-480419.

  18. An investigation into factors affecting the precision of CT radiation dose profile width measurements using radiochromic films

    SciTech Connect

    Li, Baojun Behrman, Richard H.

    2015-04-15

    Purpose: To investigate the impact of x-ray beam energy, exposure intensity, and flat-bed scanner uniformity and spatial resolution on the precision of computed tomography (CT) beam width measurements using Gafchromic XR-QA2 film and an off-the-shelf document scanner. Methods: Small strips of Gafchromic film were placed at isocenter in a CT scanner and exposed at various x-ray beam energies (80–140 kVp), exposure levels (50–400 mA s), and nominal beam widths (1.25, 5, and 10 mm). The films were scanned in reflection mode on a Ricoh MP3501 flat-bed document scanner using several spatial resolution settings (100 to 400 dpi) and at different locations on the scanner bed. Reflection measurements were captured in digital image files and radiation dose profiles generated by converting the image pixel values to air kerma through film calibration. Beam widths were characterized by full width at half maximum (FWHM) and full width at tenth maximum (FWTM) of dose profiles. Dependences of these parameters on the above factors were quantified in percentage change from the baselines. Results: The uncertainties in both FWHM and FWTM caused by varying beam energy, exposure level, and scanner uniformity were all within 4.5% and 7.6%, respectively. Increasing scanner spatial resolution significantly increased the uncertainty in both FWHM and FWTM, with FWTM affected by almost 8 times more than FWHM (48.7% vs 6.5%). When uncalibrated dose profiles were used, FWHM and FWTM were over-estimated by 11.6% and 7.6%, respectively. Narrower beam width appeared more sensitive to the film calibration than the wider ones (R{sup 2} = 0.68 and 0.85 for FWHM and FWTM, respectively). The global and maximum local background variations of the document scanner were 1.2%. The intrinsic film nonuniformity for an unexposed film was 0.3%. Conclusions: Measurement of CT beam widths using Gafchromic XR-QA2 films is robust against x-ray energy, exposure level, and scanner uniformity. With proper film

  19. Halocarbon ozone depletion and global warming potentials

    NASA Technical Reports Server (NTRS)

    Cox, Richard A.; Wuebbles, D.; Atkinson, R.; Connell, Peter S.; Dorn, H. P.; Derudder, A.; Derwent, Richard G.; Fehsenfeld, F. C.; Fisher, D.; Isaksen, Ivar S. A.

    1990-01-01

    Concern over the global environmental consequences of fully halogenated chlorofluorocarbons (CFCs) has created a need to determine the potential impacts of other halogenated organic compounds on stratospheric ozone and climate. The CFCs, which do not contain an H atom, are not oxidized or photolyzed in the troposphere. These compounds are transported into the stratosphere where they decompose and can lead to chlorine catalyzed ozone depletion. The hydrochlorofluorocarbons (HCFCs or HFCs), in particular those proposed as substitutes for CFCs, contain at least one hydrogen atom in the molecule, which confers on these compounds a much greater sensitivity toward oxidation by hydroxyl radicals in the troposphere, resulting in much shorter atmospheric lifetimes than CFCs, and consequently lower potential for depleting ozone. The available information is reviewed which relates to the lifetime of these compounds (HCFCs and HFCs) in the troposphere, and up-to-date assessments are reported of the potential relative effects of CFCs, HCFCs, HFCs, and halons on stratospheric ozone and global climate (through 'greenhouse' global warming).

  20. Convective Polymer Depletion on Pair Particle Interactions

    NASA Astrophysics Data System (ADS)

    Fan, Tai-Hsi; Taniguchi, Takashi; Tuinier, Remco

    2011-11-01

    Understanding transport, reaction, aggregation, and viscoelastic properties of colloid-polymer mixture is of great importance in food, biomedical, and pharmaceutical sciences. In non-adsorbing polymer solutions, colloidal particles tend to aggregate due to the depletion-induced osmotic or entropic force. Our early development for the relative mobility of pair particles assumed that polymer reorganization around the particles is much faster than particle's diffusive time, so that the coupling of diffusive and convective effects can be neglected. Here we present a nonequilibrium two-fluid (polymer and solvent) model to resolve the convective depletion effect. The theoretical framework is based on ground state approximation and accounts for the coupling of fluid flow and polymer transport to better describe pair particle interactions. The momentum and polymer transport, chemical potential, and local viscosity and osmotic pressure are simultaneously solved by numerical approximation. This investigation is essential for predicting the demixing kinetics in the pairwise regime for colloid-polymer mixtures. This work is supported by NSF CMMI 0952646.

  1. Stratospheric ozone depletion and animal health.

    PubMed

    Mayer, S J

    1992-08-08

    There is an increasing concern over ozone depletion and its effects on the environment and human health. However, the increase in ultraviolet-B radiation (UV-B) that would result from significant losses of ozone is also potentially harmful to animals. Any increase in disease in domestic species would not only have serious animal welfare implications but may also be economically important. The diseases which are likely to increase if ozone depletion continues include the squamous cell carcinomas of the exposed, non-pigmented areas of cats, cattle, sheep and horses. Uberreiter's syndrome in dogs is also associated with exposure to UV-B and may be expected to increase, as may the severity of conditions such as infectious keratoconjunctivitis (New Forest eye) in cattle. Aquaculture systems in which fish often have little or no protection by shading may also be at risk. Cataracts and skin lesions have been associated with the exposure of farmed fish to ultraviolet radiation and have resulted in significant losses.

  2. Magnitude and frequency analysis on river width widening caused by Typhoon Morakot in the Kaoping River watershed, Taiwan

    NASA Astrophysics Data System (ADS)

    Yang, S. Y.; Jan, C. D.; Wang, Y. C.

    2014-12-01

    Active evolving rivers are some of the most dynamic and sensitive parts of landscapes. From geologic and geomorphic perspectives, a stable river channel can adjust its width, depth, and slope to prevent significant aggradation or degradation caused by external triggers, e.g., hydrologic events caused by typhoon storms. In particular, the processes of lateral riverbank erosion play a majorly important role in forming horizontal river geomorphology, dominating incised river widens and meanders. Sediment materials produced and mobilized from riverbanks can also be substantial sediment supplying into river channel networks, affecting watershed sediment yield. In Taiwan, the geological and climatic regimes usually combine to generate severely lateral erosion and/or riverbed deposition along river channels, causing the significant change in river width. In the August of 2009, Typhoon Morakot brought severe rainfall of about 2000 mmin Southern Taiwan during three days at the beginning of Aug. 5, leading to significant changes in geomorphic system. Here we characterized river width widening (including Cishan, Laonong, and Ilao Rivers) in the Kaoping River watershed after Typhoon Morakot disturbance interpreted through a power law. On the basis of a temporal pair (2008 and 2009) of Formosat-II (Formosa satellite II) images analysis, the river channels were digitalized within geographic information system (GIS), and river widths were extracted per 100 m along the rivers, then differentiating the adjustment of river width before and after Typhoon Morkot. The river width adjusted from -83 m (contracting) to 1985 m (widening), with an average of 170 m. The noncumulative frequency-magnitude distribution for river width adjustment caused by Typhoon Morakot in the study area satisfies a power-law relation with a determined coefficient (r2) of 0.95, over the range from 65 m to 2373m in the study area. Moreover, the value of the power-law exponent is equal to -2.09. This pattern

  3. The Statistical Distributions of Landslide Length to Width Ratios

    NASA Astrophysics Data System (ADS)

    Taylor, F. E.; Malamud, B. D.

    2012-04-01

    There has been considerable effort in analysis of the frequency-size statistics of landslide areas and volumes, yet less attention to the statistics of landslide shape. Here, we use two substantially complete triggered event landslide area inventories to quantify how length (L) to width (W) ratios vary as a function of landslide area. The first inventory is 11,111 landslides triggered by the 17 January 1994 Northridge earthquake in California and the second inventory is 9594 landslides triggered by heavy rainfall from Hurricane Mitch in Guatemala in late October and early November 1998. We assume that all landslide shapes can be abstracted to a rectangle L - W , and find that the ratio of the long side (L) to the short side (W) of this shape varies with landslide area. The length-to-width ratio, L/W , is calculated by two methods which are considered separately: (i) from a quadratic equation using the given inventory landslide area and perimeter; (ii) applying a 'bounding box' where L is the longest linear axis of the landslide and W perpendicular to this. For each of the two methods, the statistical distribution using Maximum likelihood estimation of L/W values were then considered for eight landslide area categories (bins) increasing logarithmically: AL = 100-199, 200-399, 400-799, 800-1599, 1600-3199, 3200-6399, 6400-12,799, 12,800-25,600 m2. We find that for each landslide area bin considered, the probability density function of L/W follows reasonably well a three-parameter inverse gamma distribution; this distribution has a power-law decay with exponent (ρ + 1) for medium and large landslide areas and an exponential rollover for small areas. There is a relatively low probability of landslides where L/W = 1 (i.e. a square), with the maximum probability of occurrence for L/W = 1.8 to 2.2 for landside areas in categories 100-199, ..., 3200-6399 m2, and L/W = 3 and 7 for the two largest landslide area categories. For the three landslide area categories between

  4. Scanning electron microscope measurement of width and shape of 10nm patterned lines using a JMONSEL-modeled library.

    PubMed

    Villarrubia, J S; Vladár, A E; Ming, B; Kline, R J; Sunday, D F; Chawla, J S; List, S

    2015-07-01

    The width and shape of 10nm to 12 nm wide lithographically patterned SiO2 lines were measured in the scanning electron microscope by fitting the measured intensity vs. position to a physics-based model in which the lines' widths and shapes are parameters. The approximately 32 nm pitch sample was patterned at Intel using a state-of-the-art pitch quartering process. Their narrow widths and asymmetrical shapes are representative of near-future generation transistor gates. These pose a challenge: the narrowness because electrons landing near one edge may scatter out of the other, so that the intensity profile at each edge becomes width-dependent, and the asymmetry because the shape requires more parameters to describe and measure. Modeling was performed by JMONSEL (Java Monte Carlo Simulation of Secondary Electrons), which produces a predicted yield vs. position for a given sample shape and composition. The simulator produces a library of predicted profiles for varying sample geometry. Shape parameter values are adjusted until interpolation of the library with those values best matches the measured image. Profiles thereby determined agreed with those determined by transmission electron microscopy and critical dimension small-angle x-ray scattering to better than 1 nm. Published by Elsevier B.V.

  5. Relaxation Times and Line Widths of Isotopically-Substituted Nitroxides in Aqueous Solution at X-band

    PubMed Central

    Biller, Joshua R.; Meyer, Virginia; Elajaili, Hanan; Rosen, Gerald M.; Kao, Joseph P.Y.; Eaton, Sandra S.; Eatona, Gareth R.

    2011-01-01

    Optimization of nitroxides as probes for EPR imaging requires detailed understanding of spectral properties. Spin lattice relaxation times, spin packet line widths, nuclear hyperfine splitting, and overall lineshapes were characterized for six low molecular weight nitroxides in dilute deoxygenated aqueous solution at X-band. The nitroxides included 6-member, unsaturated 5-member, or saturated 5-member rings, most of which were isotopically labeled. The spectra are near the fast tumbling limit with T1 ~ T2 in the range of 0.50 to 1.1 μs at ambient temperature. Both spin-lattice relaxation T1 and spin-spin relaxation T2 are longer for 15N- than for 14N-nitroxides. The dominant contributions to T1 are modulation of nitrogen hyperfine anisotropy and spin rotation. Dependence of T1 on nitrogen nuclear spin state mI was observed for both 14N and 15N. Unresolved hydrogen/deuterium hyperfine couplings dominate overall line widths. Lineshapes were simulated by including all nuclear hyperfine couplings and spin packet line widths that agreed with values obtained by electron spin echo. Line widths and relaxation times are predicted to be about the same at 250 MHz as at X-band. PMID:21843961

  6. Gate-width impact on NIR FRET lifetime fitting using gated ICCD

    NASA Astrophysics Data System (ADS)

    Chen, Sez-Jade; Intes, Xavier

    2016-03-01

    Förster Resonance Energy Transfer (FRET) is widely used to sense molecular interactions occurring at the nanoscale. In vitro and ex vivo protocols for visualizing FRET are already well-established, but in vivo studies have proven to be more challenging. One issue that hinders in vivo visualization of FRET is the higher absorption and scattering of visible light within tissues. In this case, light in the near-infrared (NIR) spectral window is required for increased depth sensing. Moreover, due to spectral variation in optical properties as well as heterogeneous spatial distribution, lifetime-based FRET imaging is preferred. Herein, we investigate the effect of temporal acquisition settings on the lifetime-based estimation of the fraction of quenched donor molecules (A1) as well as the quenched donor lifetime (τ1). We performed in silico, in vitro, and in vivo experiments under gate widths of 300ps to 1000ps in 100ps intervals to determine the effect on quantification of A1 and τ1. Even though the NIR fluorescent dyes have shorter lifetimes then visible fluorophores, we were still able to accurately quantify FRET under all tested system gate widths and experimental conditions.

  7. Measuring the apparent width of auditory sources in normal and impaired hearing.

    PubMed

    Whitmer, William M; Seeber, Bernhard U; Akeroyd, Michael A

    2013-01-01

    It is often assumed that single sources of sound are perceived as being punctate, but this cannot be guaranteed, especially for hearing-impaired listeners. Any impairment that gives a reduction at the periphery in the accuracy of coding fine-scale temporal information must give a slight interaural jitter in the temporal information passed to higher centres, and so would be expected to lead to an effective reduction in the interaural coherence (IC) of any stimulus. This would lead to deficits in locating sounds, but deficits of imprecision, not inaccuracy. In turn, this implies that older hearing-impaired individuals should have a diminished perception of auditory space, affecting their abilities to perceive clear, concise, punctate spatial impressions or to separate sounds by location. The current work tested this hypothesis by using two separate visual-analogy methods to measure auditory source width for broadband sounds. In one method, the listener sketched the auditory image, a visual-description task, and for the other, the listener selected the closest one of a set of pre-drawn visual sketches (note that the first is an open-set experiment, whereas the second is a closed-set experiment). We found that older hearing-impaired listeners had increased difficulty in judging changes in interaural coherence, showing a corresponding insensitivity to auditory source width in the visual-analogy tasks.

  8. Extraction and analysis of the width, gray scale and radian in Chinese signature handwriting.

    PubMed

    Chen, Xiaohong

    2015-10-01

    Forensic handwriting examination is a relevant identification process in forensic science. This research obtained ideas from the process of features detection and analysis in forensic handwriting examination. A Chinese signature database was developed and comprised original signatures, freehand imitation forgeries, random forgeries and tracing imitation forgeries. The features of width, gray scale and radian combined with stroke orders were automatically extracted after image processing. A correlation coefficient was used to precisely characterize and express the similarities between signatures. To validate the differences between writers, a multivariate analysis of the variance was employed. The canonical discriminant analysis was performed between the original and non-original signatures; the cross-validation estimated the discriminating power of the width, gray scale and radian data. It is suggested that the extraction and analysis of these properties in Chinese signatures is reasonable. Meanwhile, forensic handwriting examination using the quantitative feature extraction and statistical analysis methods in this research could be performed with a satisfactory result in the discriminant analysis.

  9. MEASUREMENTS OF NON-THERMAL LINE WIDTHS IN SOLAR ACTIVE REGIONS

    SciTech Connect

    Brooks, David H.; Warren, Harry P.

    2016-03-20

    Spectral line widths are often observed to be larger than can be accounted for by thermal and instrumental broadening alone. This excess broadening is a key observational constraint for both nanoflare and wave dissipation models of coronal heating. Here we present a survey of non-thermal velocities measured in the high temperature loops (1–4 MK) often found in the cores of solar active regions. This survey of Hinode Extreme Ultraviolet Imaging Spectrometer (EIS) observations covers 15 non-flaring active regions that span a wide range of solar conditions. We find relatively small non-thermal velocities, with a mean value of 17.6 ± 5.3 km s{sup −1}, and no significant trend with temperature or active region magnetic flux. These measurements appear to be inconsistent with those expected from reconnection jets in the corona, chromospheric evaporation induced by coronal nanoflares, and Alfvén wave turbulence models. Furthermore, because the observed non-thermal widths are generally small, such measurements are difficult and susceptible to systematic effects.

  10. Measurements of Non-thermal Line Widths in Solar Active Regions

    NASA Astrophysics Data System (ADS)

    Brooks, David H.; Warren, Harry P.

    2016-03-01

    Spectral line widths are often observed to be larger than can be accounted for by thermal and instrumental broadening alone. This excess broadening is a key observational constraint for both nanoflare and wave dissipation models of coronal heating. Here we present a survey of non-thermal velocities measured in the high temperature loops (1-4 MK) often found in the cores of solar active regions. This survey of Hinode Extreme Ultraviolet Imaging Spectrometer (EIS) observations covers 15 non-flaring active regions that span a wide range of solar conditions. We find relatively small non-thermal velocities, with a mean value of 17.6 ± 5.3 km s-1, and no significant trend with temperature or active region magnetic flux. These measurements appear to be inconsistent with those expected from reconnection jets in the corona, chromospheric evaporation induced by coronal nanoflares, and Alfvén wave turbulence models. Furthermore, because the observed non-thermal widths are generally small, such measurements are difficult and susceptible to systematic effects.

  11. Satellite cell depletion does not inhibit adult skeletal muscle regrowth following unloading-induced atrophy

    PubMed Central

    Jackson, Janna R.; Mula, Jyothi; Kirby, Tyler J.; Fry, Christopher S.; Lee, Jonah D.; Ubele, Margo F.; Campbell, Kenneth S.; McCarthy, John J.; Peterson, Charlotte A.

    2012-01-01

    Resident muscle stem cells, known as satellite cells, are thought to be the main mediators of skeletal muscle plasticity. Satellite cells are activated, replicate, and fuse into existing muscle fibers in response to both muscle injury and mechanical load. It is generally well-accepted that satellite cells participate in postnatal growth, hypertrophy, and muscle regeneration following injury; however, their role in muscle regrowth following an atrophic stimulus remains equivocal. The current study employed a genetic mouse model (Pax7-DTA) that allowed for the effective depletion of >90% of satellite cells in adult muscle upon the administration of tamoxifen. Vehicle and tamoxifen-treated young adult female mice were either hindlimb suspended for 14 days to induce muscle atrophy or hindlimb suspended for 14 days followed by 14 days of reloading to allow regrowth, or they remained ambulatory for the duration of the experimental protocol. Additionally, 5-bromo-2′-deoxyuridine (BrdU) was added to the drinking water to track cell proliferation. Soleus muscle atrophy, as measured by whole muscle wet weight, fiber cross-sectional area, and single-fiber width, occurred in response to suspension and did not differ between satellite cell-depleted and control muscles. Furthermore, the depletion of satellite cells did not attenuate muscle mass or force recovery during the 14-day reloading period, suggesting that satellite cells are not required for muscle regrowth. Myonuclear number was not altered during either the suspension or the reloading period in soleus muscle fibers from vehicle-treated or satellite cell-depleted animals. Thus, myonuclear domain size was reduced following suspension due to decreased cytoplasmic volume and was completely restored following reloading, independent of the presence of satellite cells. These results provide convincing evidence that satellite cells are not required for muscle regrowth following atrophy and that, instead, the myonuclear

  12. High-speed charge transfer pinned-photodiode for a CMOS time-of-flight range image sensor

    NASA Astrophysics Data System (ADS)

    Takeshita, Hiroaki; Sawada, Tomonari; Iida, Tetsuya; Yasutomi, Keita; Kawahito, Shoji

    2010-01-01

    This paper presents a structure and method of range calculation for CMOS time-of-flight(TOF) range image sensors using pinned photodiodes. In the proposed method, a LED light with short pulse width and small duty ratio irradiates the objects and a back-reflected light is received by the CMOS TOF range imager.Each pixel has a pinned photodiode optimized for high speed charge transfer and unwanted charge draining. In TOF range image sensors, high speed charge transfer from the light receiving part to a charge accumulator is essential.It was found that the fastest charge transfer can be realized when the lateral electric field along the axis of charge transfer is constant and this conditon is met when the shape of the diode exactly follows the relationship between the fully-depleted potential and width. A TOF range imager prototype is designed and implemented with 0.18um CMOS image sensor technology with pinned photodiode 4transistor(T) pixels. The measurement results show that the charge transfer time is a few ns from the pinned photodiode to a charge accumulator.

  13. Teasing Foggy Memories out of Pines on the California Channel Islands Using Tree-Ring Width and Stable Isotope Approaches

    NASA Astrophysics Data System (ADS)

    Williams, A. P.; Still, C. J.; Fischer, D. T.; Leavitt, S. W.

    2006-12-01

    The coast of California is home to many rare, endemic conifers and other plants that are not well adapted to the Mediterranean climate that prevails across most of the state. It has long been suggested that coastal pines survived the early-Pleistocene transition to a warmer and drier environment because they benefit from frequent fog and low stratus clouds that provide much needed water inputs and shading during the rainless summer. Here, we report evidence for the importance of this summer cloudiness to Torrey pines (Pinus torreyana) growing on Santa Rosa Island in Channel Islands National Park. We developed a tree-ring width chronology and quantified the relative importance of winter/spring precipitation and summer fog by comparing ring widths to nearby rainfall records and airport cloud-ceiling height data. While winter/spring precipitation explains most of the variation in annual tree-ring width (R2 = 0.592), the frequency of summertime fog correlated significantly and positively with annual ring width for 52 years of available fog data when the effect of winter/spring precipitation was removed (R2 = 0.118). The correlation between fog frequency and ring width decreased sharply when the range of possible cloud-ceiling heights deviated from the habitat range of the Torrey pine stand, emphasizing the importance of direct cloud immersion to these pines. In addition, the relationship between fog frequency and ring width was strongest in the 26 years that had enough winter/spring rainfall to maintain above-average soil moisture throughout the dry summer months (R2 = 0.312). This suggests that Torrey pines have an adaptive growing season length and that summer fog-water inputs are supplemental but not substantial enough to sustain tree growth independently. It may also be suggested that when summer growth does occur, the frequency of summer fog and stratus may govern growing season length. This made a "fog signal" difficult to detect in the stable isotope (carbon and

  14. Local depletion of glycogen with supramaximal exercise in human skeletal muscle fibres.

    PubMed

    Gejl, Kasper D; Ørtenblad, Niels; Andersson, Erik; Plomgaard, Peter; Holmberg, Hans-Christer; Nielsen, Joachim

    2017-05-01

    Glycogen is stored in local spatially distinct compartments within skeletal muscle fibres and is the main energy source during supramaximal exercise. Using quantitative electron microscopy, we show that supramaximal exercise induces a differential depletion of glycogen from these compartments and also demonstrate how this varies with fibre types. Repeated exercise alters this compartmentalized glycogen depletion. The results obtained in the present study help us understand the muscle metabolic dynamics of whole body repeated supramaximal exercise, and suggest that the muscle has a compartmentalized local adaptation to repeated exercise, which affects glycogen depletion. Skeletal muscle glycogen is heterogeneously distributed in three separated compartments (intramyofibrillar, intermyofibrillar and subsarcolemmal). Although only constituting 3-13% of the total glycogen volume, the availability of intramyofibrillar glycogen is of particular importance to muscle function. The present study aimed to investigate the depletion of these three subcellular glycogen compartments during repeated supramaximal exercise in elite athletes. Ten elite cross-country skiers (aged 25 ± 4 years, V̇O2 max : 65 ± 4 ml kg(-1)  min(-1) ; mean ± SD) performed four ∼4 min supramaximal sprint time trials (STT 1-4) with 45 min of recovery. The subcellular glycogen volumes in musculus triceps brachii were quantified from electron microscopy images before and after both STT 1 and 4. During STT 1, the depletion of intramyofibrillar glycogen was higher in type 1 fibres [-52%; (-89:-15%)] than type 2 fibres [-15% (-52:22%)] (P = 0.02), whereas the depletion of intermyofibrillar glycogen [main effect: -19% (-33:0%), P = 0.006] and subsarcolemmal glycogen [main effect: -35% (-66:0%), P = 0.03] was similar between fibre types. By contrast, only intermyofibrillar glycogen volume was significantly reduced during STT 4, in both fibre types [main effect: -31% (-50:-11%), P = 0

  15. EFFECTS OF X-RAY BEAM ANGLE AND GEOMETRIC DISTORTION ON WIDTH OF EQUINE THORACOLUMBAR INTERSPINOUS SPACES USING RADIOGRAPHY AND COMPUTED TOMOGRAPHY-A CADAVERIC STUDY.

    PubMed

    Djernaes, Julie D; Nielsen, Jon V; Berg, Lise C

    2017-03-01

    The widths of spaces between the thoracolumbar processi spinosi (interspinous spaces) are frequently assessed using radiography in sports horses; however effects of varying X-ray beam angles and geometric distortion have not been previously described. The aim of this prospective, observational study was to determine whether X-ray beam angle has an effect on apparent widths of interspinous spaces. Thoracolumbar spine specimens were collected from six equine cadavers and left-right lateral radiographs and sagittal and dorsal reconstructed computed tomographic (CT) images were acquired. Sequential radiographs were acquired with each interspinous space in focus. Measurements were performed for each interspinous space in the focus position and up to eight angled positions as the interspinous space moved away from focus (±). Focus position measurements were compared to matching sagittal CT measurements. Effect of geometric distortion was evaluated by comparing the interspinous space in radiographs with sagittal and dorsal reconstructed CT images. A total of 49 interspinous spaces were sampled, yielding 274 measurements. X-ray beam angle significantly affected measured width of interspinous spaces in position +3 (P = 0.038). Changes in width did not follow a consistent pattern. Interspinous space widths in focus position were significantly smaller in radiographs compared to matching reconstructed CT images for backs diagnosed with kissing spine syndrome (P < 0.001). Geometric distortion markedly affected appearance of interspinous space width between planes. In conclusion, X-ray beam angle and geometric distortion influence radiographically measured widths of interspinous spaces in the equine thoracolumbar spine, and this should be taken into consideration when evaluating sport horses. © 2016 American College of Veterinary Radiology.

  16. Correlation of Density Pedestal Width and Neutral Penetration

    NASA Astrophysics Data System (ADS)

    Xu, X. Q.; Nevins, W. M.; Cohen, R. H.; Rognlien, T. D.; Umansky, M. V.

    2003-10-01

    Pedestal studies in DIII-D and C-Mod find a good correlation between the width of the H-mode density barrier and the neutral penetration length.[1][2] These results suggest that the width may be set by the combined effects of neutral and plasma transport. This paper is a report on fluid simulations of boundary plasma using BOUT code [3] with neutral source added. Thus both neutral and plasma physics are treated. The plasma transport is self-consistently driven by boundary turbulence due to the resistive X-point mode, while neutral is described by a simple fluid diffusive model. The plasma profiles are evolved on the same time scale as the turbulence for the given heat source from the core plasma and particle source from the neutrals. For prescribed neutral profiles, we find the formation of a density pedestal inside the separatrix in the L-mode even though the calculated plasma diffusion coefficients are almost radially constant and without the formation of a temperature pedestal. These results support the hypothesis that particle fueling can provide the dominant control for the size of the H-mode density barrier. The width of the density barrier, and its relationship to pedestal height and neutral penetration length at the midplane, will be given by using hyperbolic-tangent fit to the simulation data. [1] R.J.Groebner, M.A.Mahdavi, A.W.Leonard, 19th IAEA Fusion Energy Conference(Lyon, France, 14 to 19 October 2002), IAEA-CN-94/EX/C2-3. [2] D.Mossessian, J.W.Hughes, M.Greenwald, et al., ``Local dimensionless identity method as a tool for studying H-mode pedestal'', The 9th Joint US-European TTF workshop (Madison, Wisconsin, April 2nd - 5th, 2003). [3] X.Q.Xu, R.H.Cohen, T.D.Rognlien and J.R.Myra, Physics of Plasma, Vol. 7, 1951-1958 (2000).

  17. Invariantly propagating dissolution fingers in finite-width systems

    NASA Astrophysics Data System (ADS)

    Dutka, Filip; Szymczak, Piotr

    2016-04-01

    Dissolution fingers are formed in porous medium due to positive feedback between transport of reactant and chemical reactions [1-4]. We investigate two-dimensional semi-infinite systems, with constant width W in one direction. In numerical simulations we solve the Darcy flow problem combined with advection-dispersion-reaction equation for the solute transport to track the evolving shapes of the fingers and concentration of reactant in the system. We find the stationary, invariantly propagating finger shapes for different widths of the system, flow and reaction rates. Shape of the reaction front, turns out to be controlled by two dimensionless numbers - the (width-based) Péclet number PeW = vW/Dφ0 and Damköhler number DaW = ksW/v, where k is the reaction rate, s - specific reactive surface area, v - characteristic flow rate, D - diffusion coefficient of the solute, and φ0 - initial porosity of the rock matrix. Depending on PeW and DaW stationary shapes can be divided into seperate classes, e.g. parabolic-like and needle-like structures, which can be inferred from theoretical predictions. In addition we determine velocity of propagating fingers in time and concentration of reagent in the system. Our simulations are compared with natural forms (solution pipes). P. Ortoleva, J. Chadam, E. Merino, and A. Sen, Geochemical self-organization II: the reactive-infiltration instability, Am. J. Sci, 287, 1008-1040 (1987). M. L. Hoefner, and H. S. Fogler. Pore evolution and channel formation during flow and reaction in porous media, AIChE Journal 34, 45-54 (1988). C. E. Cohen, D. Ding, M. Quintard, and B. Bazin, From pore scale to wellbore scale: impact of geometry on wormhole growth in carbonate acidization, Chemical Engineering Science 63, 3088-3099 (2008). P. Szymczak and A. J. C. Ladd, Reactive-infiltration nstabilities in rocks. Part II: Dissolution of a porous matrix, J. Fluid Mech. 738, 591-630 (2014).

  18. Changes in the width of the tropical belt due to simple radiative forcing changes in the GeoMIP simulations

    NASA Astrophysics Data System (ADS)

    Davis, Nicholas A.; Seidel, Dian J.; Birner, Thomas; Davis, Sean M.; Tilmes, Simone

    2016-08-01

    Model simulations of future climates predict a poleward expansion of subtropical arid climates at the edges of Earth's tropical belt, which would have significant environmental and societal impacts. This expansion may be related to the poleward shift of the Hadley cell edges, where subsidence stabilizes the atmosphere and suppresses precipitation. Understanding the primary drivers of tropical expansion is hampered by the myriad forcing agents in most model projections of future climate. While many previous studies have examined the response of idealized models to simplified climate forcings and the response of comprehensive climate models to more complex climate forcings, few have examined how comprehensive climate models respond to simplified climate forcings. To shed light on robust processes associated with tropical expansion, here we examine how the tropical belt width, as measured by the Hadley cell edges, responds to simplified forcings in the Geoengineering Model Intercomparison Project (GeoMIP). The tropical belt expands in response to a quadrupling of atmospheric carbon dioxide concentrations and contracts in response to a reduction in the solar constant, with a range of a factor of 3 in the response among nine models. Models with more surface warming and an overall stronger temperature response to quadrupled carbon dioxide exhibit greater tropical expansion, a robust result in spite of inter-model differences in the mean Hadley cell width, parameterizations, and numerical schemes. Under a scenario where the solar constant is reduced to offset an instantaneous quadrupling of carbon dioxide, the Hadley cells remain at their preindustrial width, despite the residual stratospheric cooling associated with elevated carbon dioxide levels. Quadrupled carbon dioxide produces greater tropical belt expansion in the Southern Hemisphere than in the Northern Hemisphere. This expansion is strongest in austral summer and autumn. Ozone depletion has been argued to cause

  19. Diagnostic Accuracy of Neutrophil/Lymphocyte Ratio, Red Cell Distribution Width and Platelet Distribution Width in Ovarian Torsion.

    PubMed

    Yilmaz, M; Cimilli, G; Saritemur, M; Demircan, F; Isaoglu, U; Kisaoglu, A; Emet, M

    2016-01-01

    The main aim of this diagnostic case-control study of 136 patients with ovarian cysts (44 patients with ovarian torsion and 92 controls) was to determine the diagnostic value of haematologic inflammatory markers (neutrophil/lymphocyte ratio [NLR], red cell distribution width [RDW] and platelet distribution width [PDW]) for torsioned ovarian cysts. The presence of a torsioned ovarian cyst was identified by a 1.18-fold increase in the NLR (95%CI: 1.04-1.34, P = 0.009), a 1.22-fold increase in the RDW (95%CI: 1.04-1.43, P = 0.023) and a 1.93-fold increase in the PDW (95%CI: 1.19-3.14, P = 0.007). The NLR was the best predictor of a torsioned ovarian cyst (AUC: 0.74; 95% CI: 0.68-0.83). When an NLR cut-off value of 2.44 was used to determine ovarian torsion, the sensitivity, specificity, + LR and -LR were 70.5%, 70.7%, 2.40 and 0.42, respectively. In conclusion, the NLR may have diagnostic and prognostic value in determining torsioned ovarian cysts.

  20. Width and Crystal Orientation Dependent Band Gap Renormalization in Substrate-Supported Graphene Nanoribbons.

    PubMed

    Kharche, Neerav; Meunier, Vincent

    2016-04-21

    The excitation energy levels of two-dimensional (2D) materials and their one-dimensional (1D) nanostructures, such as graphene nanoribbons (GNRs), are strongly affected by the presence of a substrate due to the long-range screening effects. We develop a first-principles approach combining density functional theory (DFT), the GW approximation, and a semiclassical image-charge model to compute the electronic band gaps in planar 1D systems in weak interaction with the surrounding environment. Application of our method to the specific case of GNRs yields good agreement with the range of available experimental data and shows that the band gap of substrate-supported GNRs are reduced by several tenths of an electronvolt compared to their isolated counterparts, with a width and orientation-dependent renormalization. Our results indicate that the band gaps in GNRs can be tuned by controlling screening at the interface by changing the surrounding dielectric materials.