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Sample records for bright points derived

  1. Magnetic topological analysis of coronal bright points

    Science.gov (United States)

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

    2017-10-01

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

  2. Coronal bright points associated with minifilament eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Junchao; Jiang, Yunchun; Yang, Jiayan; Bi, Yi; Li, Haidong [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Yang, Bo; Yang, Dan, E-mail: hjcsolar@ynao.ac.cn [Also at Graduate School of Chinese Academy of Sciences, Beijing, China. (China)

    2014-12-01

    Coronal bright points (CBPs) are small-scale, long-lived coronal brightenings that always correspond to photospheric network magnetic features of opposite polarity. In this paper, we subjectively adopt 30 CBPs in a coronal hole to study their eruptive behavior using data from the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory. About one-quarter to one-third of the CBPs in the coronal hole go through one or more minifilament eruption(s) (MFE(s)) throughout their lifetimes. The MFEs occur in temporal association with the brightness maxima of CBPs and possibly result from the convergence and cancellation of underlying magnetic dipoles. Two examples of CBPs with MFEs are analyzed in detail, where minifilaments appear as dark features of a cool channel that divide the CBPs along the neutral lines of the dipoles beneath. The MFEs show the typical rising movements of filaments and mass ejections with brightenings at CBPs, similar to large-scale filament eruptions. Via differential emission measure analysis, it is found that CBPs are heated dramatically by their MFEs and the ejected plasmas in the MFEs have average temperatures close to the pre-eruption BP plasmas and electron densities typically near 10{sup 9} cm{sup –3}. These new observational results indicate that CBPs are more complex in dynamical evolution and magnetic structure than previously thought.

  3. An Exploration of the Emission Properties of X-Ray Bright Points Seen with SDO

    Science.gov (United States)

    Saar, S. H.; Elsden, T.; Muglach, K.

    2012-01-01

    We present preliminary results of a study of X-ray Bright Point (XBP) EUV emission and its dependence on other properties. The XBPs were located using a new, automated XBP finder for AlA developed as part of the Feature Finding Team for SDO Computer Vision. We analyze XBPs near disk center, comparing AlA EUV fluxes, HMI LOS magnetic fields, and photospheric flow fields (derived from HMI data) to look for relationships between XBP emission, magnetic flux, velocity fields, and XBP local environment. We find some evidence for differences in the mean XBP temperature with environment. Unsigned magnetic flux is correlated with XBP emission, though other parameters play a role. The majority of XBP footpoints are approaching each other, though at a slight angle from head-on on average. We discuss the results in the context of XBP heating.

  4. Automatic Identification of Solar X-Ray Bright Points in Hinode X-Ray Data

    Science.gov (United States)

    Adams, M. L.; Tennant, Allyn F.; Cirtain, J. W.

    2010-01-01

    We have automated a method that is used to find point sources in Chandra X-ray telescope data, to identify solar bright points in Hinode X-ray data. This tool, called lextrct, first identifies candidate sources that are brighter than the surrounding background. The algorithm also allows selected pixels to be excluded from the source-finding, thus allowing saturated pixels (from flares and/or active regions) to be ignored. We then use lextrct to fit the sources to two-dimensional, elliptical Gaussians. The size and orientation give an approximation of the shape of the bright points. We are in the process of analyzing observations through the Al_poly filter with a four-second exposure time, to obtain a catalogue of bright points, which will include their sizes, lifetimes, intensities, and position on the solar disk

  5. On the fractional derivatives at extrema points

    Directory of Open Access Journals (Sweden)

    Mohammed Al-Refai

    2012-08-01

    Full Text Available We correct a recent result concerning the fractional derivative at extrema points. We then establish new results for the Caputo and Riemann-Liouville fractional derivatives at extrema points.

  6. Bright points and ejections observed on the sun by the KORONAS-FOTON instrument TESIS

    Science.gov (United States)

    Ulyanov, A. S.; Bogachev, S. A.; Kuzin, S. V.

    2010-10-01

    Five-second observations of the solar corona carried out in the FeIX 171 Å line by the KORONAS-FOTON instrument TESIS are used to study the dynamics of small-scale coronal structures emitting in and around coronal bright points. The small-scale structures of the lower corona display complex dynamics similar to those of magnetic loops located at higher levels of the solar corona. Numerous detected oscillating structures with sizes below 10 000 km display oscillation periods from 50 to 350 s. The period distributions of these structures are different for P 150 s, which implies that different oscillation modes are excited at different periods. The small-scale structures generate numerous flare-like events with energies 1024-1026 erg (nanoflares) and with a spatial density of one event per arcsecond or more observed over an area of 4 × 1011 km2. Nanoflares are not associated with coronal bright points, and almost uniformly cover the solar disk in the observation region. The ejections of solar material from the coronal bright points demonstrate velocities of 80-110 km/s.

  7. The formation and disintegration of magnetic bright points observed by sunrise/IMaX

    Energy Technology Data Exchange (ETDEWEB)

    Utz, D.; Del Toro Iniesta, J. C.; Bellot Rubio, L. R. [Instituto de Astrofísica de Andalucía (CSIC), Apdo. de Correos 3004, E-18080 Granada (Spain); Jurčák, J. [Astronomical Institute, Academy of Sciences of the Czech Republic, 251 65 Ondřejov (Czech Republic); Martínez Pillet, V. [Instituto de Astrofísica de Canarias, Vía Láctea, s/n, E-38200 La Laguna (Spain); Solanki, S. K. [Max-Planck Institut für Sonnensystemforschung, Max-Planck-Strasse, 2, D-37191 (Germany); Schmidt, W., E-mail: utz@iaa.es, E-mail: dominik.utz@uni-graz.at [Kiepenheuer-Institut für Sonnenphysik, Schöneckstrasse 6, D-79104 Freiburg (Germany)

    2014-12-01

    The evolution of the physical parameters of magnetic bright points (MBPs) located in the quiet Sun (mainly in the interwork) during their lifetime is studied. First, we concentrate on the detailed description of the magnetic field evolution of three MBPs. This reveals that individual features follow different, generally complex, and rather dynamic scenarios of evolution. Next, we apply statistical methods on roughly 200 observed MBP evolutionary tracks. MBPs are found to be formed by the strengthening of an equipartition field patch, which initially exhibits a moderate downflow. During the evolution, strong downdrafts with an average velocity of 2.4 km s{sup –1} set in. These flows, taken together with the concurrent strengthening of the field, suggest that we are witnessing the occurrence of convective collapses in these features, although only 30% of them reach kG field strengths. This fraction might turn out to be larger when the new 4 m class solar telescopes are operational as observations of MBPs with current state of the art instrumentation could still be suffering from resolution limitations. Finally, when the bright point disappears (although the magnetic field often continues to exist) the magnetic field strength has dropped to the equipartition level and is generally somewhat weaker than at the beginning of the MBP's evolution. Also, only relatively weak downflows are found on average at this stage of the evolution. Only 16% of the features display upflows at the time that the field weakens, or the MBP disappears. This speaks either for a very fast evolving dynamic process at the end of the lifetime, which could not be temporally resolved, or against strong upflows as the cause of the weakening of the field of these magnetic elements, as has been proposed based on simulation results. It is noteworthy that in about 10% of the cases, we observe in the vicinity of the downflows small-scale strong (exceeding 2 km s{sup –1}) intergranular upflows

  8. Dirac cones and Dirac saddle points of bright excitons in monolayer transition metal dichalcogenides.

    Science.gov (United States)

    Yu, Hongyi; Liu, Gui-Bin; Gong, Pu; Xu, Xiaodong; Yao, Wang

    2014-05-12

    In monolayer transition metal dichalcogenides, tightly bound excitons have been discovered with a valley pseudospin optically addressable through polarization selection rules. Here, we show that this valley pseudospin is strongly coupled to the exciton centre-of-mass motion through electron-hole exchange. This coupling realizes a massless Dirac cone with chirality index I = 2 for excitons inside the light cone, that is, bright excitons. Under moderate strain, the I = 2 Dirac cone splits into two degenerate I = 1 Dirac cones, and saddle points with a linear Dirac spectrum emerge. After binding an extra electron, the charged exciton becomes a massive Dirac particle associated with a large valley Hall effect protected from intervalley scattering. Our results point to unique opportunities to study Dirac physics, with exciton's optical addressability at specifiable momentum, energy and pseudospin. The strain-tunable valley-orbit coupling also implies new structures of exciton condensates, new functionalities of excitonic circuits and mechanical control of valley pseudospin.

  9. Temporal relations between magnetic bright points and the solar sunspot cycle

    Science.gov (United States)

    Utz, Dominik; Muller, Richard; Van Doorsselaere, Tom

    2017-12-01

    The Sun shows a global magnetic field cycle traditionally best visible in the photosphere as a changing sunspot cycle featuring roughly an 11-year period. In addition we know that our host star also harbours small-scale magnetic fields often seen as strong concentrations of magnetic flux reaching kG field strengths. These features are situated in inter-granular lanes, where they show up bright as so-called magnetic bright points (MBPs). In this short paper we wish to analyse an homogenous, nearly 10-year-long synoptic Hinode image data set recorded from 2006 November up to 2016 February in the G-band to inspect the relationship between the number of MBPs at the solar disc centre and the relative sunspot number. Our findings suggest that the number of MBPs at the solar disc centre is indeed correlated to the relative sunspot number, but with the particular feature of showing two different temporal shifts between the decreasing phase of cycle 23 including the minimum and the increasing phase of cycle 24 including the maximum. While the former is shifted by about 22 months, the latter is only shifted by less than 12 months. Moreover, we introduce and discuss an analytical model to predict the number of MBPs at the solar disc centre purely depending on the evolution of the relative sunspot number as well as the temporal change of the relative sunspot number and two background parameters describing a possibly acting surface dynamo as well as the strength of the magnetic field diffusion. Finally, we are able to confirm the plausibility of the temporal shifts by a simplistic random walk model. The main conclusion to be drawn from this work is that the injection of magnetic flux, coming from active regions as represented by sunspots, happens on faster time scales than the removal of small-scale magnetic flux elements later on.

  10. Bright and durable field emission source derived from refractory taylor cones

    Science.gov (United States)

    Hirsch, Gregory

    2016-12-20

    A method of producing field emitters having improved brightness and durability relying on the creation of a liquid Taylor cone from electrically conductive materials having high melting points. The method calls for melting the end of a wire substrate with a focused laser beam, while imposing a high positive potential on the material. The resulting molten Taylor cone is subsequently rapidly quenched by cessation of the laser power. Rapid quenching is facilitated in large part by radiative cooling, resulting in structures having characteristics closely matching that of the original liquid Taylor cone. Frozen Taylor cones thus obtained yield desirable tip end forms for field emission sources in electron beam applications. Regeneration of the frozen Taylor cones in-situ is readily accomplished by repeating the initial formation procedures. The high temperature liquid Taylor cones can also be employed as bright ion sources with chemical elements previously considered impractical to implement.

  11. Motion and Magnetic Flux Changes of Coronal Bright Points Relative to Supergranular Cell Boundaries

    Science.gov (United States)

    Yousefzadeh, M.; Safari, H.; Attie, R.; Alipour, N.

    2016-01-01

    To calculate the magnetic flux and the horizontal movement of coronal bright points (CBPs) in relation to supergranular cell boundaries, the time series of the SDO/HMI visible-light continuum images and SDO/AIA EUV images for 13 February 2011 have been studied. The supergranular lanes were detected in HMI continuum images using the automatic supergranular cell recognition method. The automatic identification and tracking method was applied for detecting the CBPs in AIA 193 Å images. By applying the ball-tracking method on HMI continuum images, the underlying flow fields were determined. By using the velocity fields and the automatic supergranular cell recognition method, the lanes and boundaries were detected. The locations of CBPs were projected on the photospheric co-spatial and co-temporal images. We found that about 90 % of the locations of CBPs correspond to the lane of the supergranular cell boundaries (network CBPs or NCBPs) of which about 40 % of them appeared at junctions. The remaining 10 % appeared within the supergranular regions (internetwork CBPs or INCBPs). The horizontal velocities for NCBPs and INCBPs were about 1.6±0.1 km s^{-1} and 1.7±0.1 km s^{-1}, respectively. Using the magnetic field extrapolation, we were able to detect the bipoles underlying CBPs, and we studied their magnetic evolution. The orientation of CBPs observed in the 171, 193, and 211 Å images and the orientation of their magnetic bipoles are positively correlated. For out of 50 INCBPs, 54 % showed cancellation, 32 % emergence, and 12 % complex flux changes. Out of 90 NCBPs, 60 % presented cancellation, 20 % showed emergence, and 20 % showed complex flux changes.

  12. Discriminant Analysis of Bright Points and Faculae: Center-to-Limb Distribution, Contrast and Morphology

    Science.gov (United States)

    Kobel, P.; Hirzberger, J.; Gandorfer, A.; Solanki, S. K.; Zakharov, V.

    2008-09-01

    High-resolution images of the solar photosphere reveal an intriguing mixture of Brights Points (BPs) and faculae at several disk positions, which is not explained by the conventional "hot wall'' model. Together with quantitative discrepancies between observations and simulations of faculae, it stresses that the fundamental relationship between BPs and faculae is not yet clear: How are BPs and faculae distributed on the solar disk? How do the photometric properties of BPs and faculae differ and vary with disk position? To tackle these issues, a necessary step is to sort the BPs and faculae at various disk positions, in order to treat them separately. We present here the first attempt to discriminate BPs and faculae, using a statistical classification approach based on Linear Discriminant Analysis (LDA). This has never been done so far, presumably due to the lack of known automated methods to distinguish such features, and to the difficulty to obtain a coherent dataset of high-resolution images recorded in the same conditions. We applied our method to high-resolution G-band and continuum images of active regions recorded at the Swedish Solar Telescope, covering several disk positions where the transition from BPs to faculae is expected. This allowed us to retrieve a first estimate of the center-to-limb variation of the relative distribution of both species. The center-to-limb distribution of BPs and faculae reveals the predominance of faculae at all disk positions except close to disk center. We argue that these ubiquitous faculae could be the transient signatures of swaying flux tubes with a wide range of inclination angles. Moreover, we statistically compared the G-band and continuum contrast of BPs and faculae, and characterized their morphology. Both the G-band and continuum contrast of BPs and faculae are found to similarly increase from center to limb. But when comparing G-band to continuum, BPs and faculae exhibit slightly different behaviours, which are

  13. A bright point source of ultrashort hard x-rays from laser bioplasmas

    CERN Document Server

    Krishnamurthy, M; Lad, Amit D; Ahmad, Saima; Narayanan, V; Rajeev, R; Kundu, M; Kumar, G Ravindra; Ray, Krishanu

    2010-01-01

    Micro and nano structures scatter light and amplify local electric fields very effectively. Energy incident as intense ultrashort laser pulses can be converted to x-rays and hot electrons more efficiently with a substrate that suitably modifies the local fields. Here we demonstrate that coating a plain glass surface with a few micron thick layer of an ubiquitous microbe, {\\it Escherichia coli}, catapults the brightness of hard x-ray bremsstrahlung emission (up to 300 keV) by more than two orders of magnitude at an incident laser intensity of 10$^{16}$ W cm$^{-2}$. This increased yield is attributed to the local enhancement of electric fields around individual {\\it E. coli} cells and is reproduced by detailed particle-in-cell (PIC) simulations. This combination of laser plasmas and biological targets can lead to turnkey, multi-kilohertz and environmentally safe sources of hard x-rays.

  14. Thermal measurements of dark and bright surface features on Vesta as derived from Dawn/VIR

    Science.gov (United States)

    Tosi, Federico; Capria, Maria Teresa; De Sanctis, M.C.; Combe, J.-Ph.; Zambon, F.; Nathues, A.; Schröder, S.E.; Li, J.-Y.; Palomba, E.; Longobardo, A.; Blewett, D.T.; Denevi, B.W.; Palmer, E.; Capaccioni, F.; Ammannito, E.; Titus, Timothy N.; Mittlefehldt, D.W.; Sunshine, J.M.; Russell, C.T.; Raymond, C.A.; Dawn/VIR Team,

    2014-01-01

    Remote sensing data acquired during Dawn’s orbital mission at Vesta showed several local concentrations of high-albedo (bright) and low-albedo (dark) material units, in addition to spectrally distinct meteorite impact ejecta. The thermal behavior of such areas seen at local scale (1-10 km) is related to physical properties that can provide information about the origin of those materials. We use Dawn’s Visible and InfraRed (VIR) mapping spectrometer hyperspectral data to retrieve surface temperatures and emissivities, with high accuracy as long as temperatures are greater than 220 K. Some of the dark and bright features were observed multiple times by VIR in the various mission phases at variable spatial resolution, illumination and observation angles, local solar time, and heliocentric distance. This work presents the first temperature maps and spectral emissivities of several kilometer-scale dark and bright material units on Vesta. Results retrieved from the infrared data acquired by VIR show that bright regions generally correspond to regions with lower temperature, while dark regions correspond to areas with higher temperature. During maximum daily insolation and in the range of heliocentric distances explored by Dawn, i.e. 2.23-2.54 AU, the warmest dark unit found on Vesta rises to a temperature of 273 K, while bright units observed under comparable conditions do not exceed 266 K. Similarly, dark units appear to have higher emissivity on average compared to bright units. Dark-material units show a weak anticorrelation between temperature and albedo, whereas the relation is stronger for bright material units observed under the same conditions. Individual features may show either evanescent or distinct margins in the thermal images, as a consequence of the cohesion of the surface material. Finally, for the two categories of dark and bright materials, we were able to highlight the influence of heliocentric distance on surface temperatures, and estimate an

  15. Multiscale assessment of progress of electrification in Indonesia based on brightness level derived from nighttime satellite imagery.

    Science.gov (United States)

    Ramdani, Fatwa; Setiani, Putri

    2017-06-01

    Availability of electricity can be used as an indicator to proximate parameters related to human well-being. Overall, the electrification process in Indonesia has been accelerating in the past two decades. Unfortunately, monitoring the country's progress on its effort to provide wider access to electricity poses challenges due to inconsistency of data provided by each national bureau, and limited availability of information. This study attempts to provide a reliable measure by employing nighttime satellite imagery to observe and to map the progress of electrification within a duration of 20 years, from 1993 to 2013. Brightness of 67,021 settlement-size points in 1993, 2003, and 2013 was assessed using data from DMSP/OLS instruments to study the electrification progress in the three service regions (Sumatera, Java-Bali, and East Indonesia) of the country's public electricity company, PLN. Observation of all service areas shows that the increase in brightness, which correspond with higher electricity development and consumption, has positive correlation with both population density (R(2) = 0.70) and urban change (R(2) = 0.79). Moreover, urban change has a stronger correlation with brightness, which is probably due to the high energy consumption in urban area per capita. This study also found that the brightness in Java-Bali region is very dominant, while the brightness in other areas has been lagging during the period of analysis. The slow development of electricity infrastructure, particularly in major parts of East Indonesia region, affects the low economic growth in some areas and formed vicious cycle.

  16. An evolutionary computation based algorithm for calculating solar differential rotation by automatic tracking of coronal bright points

    Science.gov (United States)

    Shahamatnia, Ehsan; Dorotovič, Ivan; Fonseca, Jose M.; Ribeiro, Rita A.

    2016-03-01

    Developing specialized software tools is essential to support studies of solar activity evolution. With new space missions such as Solar Dynamics Observatory (SDO), solar images are being produced in unprecedented volumes. To capitalize on that huge data availability, the scientific community needs a new generation of software tools for automatic and efficient data processing. In this paper a prototype of a modular framework for solar feature detection, characterization, and tracking is presented. To develop an efficient system capable of automatic solar feature tracking and measuring, a hybrid approach combining specialized image processing, evolutionary optimization, and soft computing algorithms is being followed. The specialized hybrid algorithm for tracking solar features allows automatic feature tracking while gathering characterization details about the tracked features. The hybrid algorithm takes advantages of the snake model, a specialized image processing algorithm widely used in applications such as boundary delineation, image segmentation, and object tracking. Further, it exploits the flexibility and efficiency of Particle Swarm Optimization (PSO), a stochastic population based optimization algorithm. PSO has been used successfully in a wide range of applications including combinatorial optimization, control, clustering, robotics, scheduling, and image processing and video analysis applications. The proposed tool, denoted PSO-Snake model, was already successfully tested in other works for tracking sunspots and coronal bright points. In this work, we discuss the application of the PSO-Snake algorithm for calculating the sidereal rotational angular velocity of the solar corona. To validate the results we compare them with published manual results performed by an expert.

  17. A 3-point derivation of dominant tree height equations

    Science.gov (United States)

    Don C. Bragg

    2011-01-01

    This paper describes a new approach for deriving height-diameter (H-D) equations from limited information and a few assumptions about tree height. Only three data points are required to fit this model, which can be based on virtually any nonlinear function. These points are the height of a tree at diameter at breast height (d.b.h.), the predicted height of a 10-inch d....

  18. Melt Patterns and Dynamics in Alaska and Patagonia Derived from Passive Microwave Brightness Temperatures

    Directory of Open Access Journals (Sweden)

    Kathryn Semmens

    2014-01-01

    Full Text Available Glaciers and icefields are critical components of Earth’s cryosphere to study and monitor for understanding the effects of a changing climate. To provide a regional perspective of glacier melt dynamics for the past several decades, brightness temperatures (Tb from the passive microwave sensor Special Sensor Microwave Imager (SSM/I were used to characterize melt regime patterns over large glacierized areas in Alaska and Patagonia. The distinctness of the melt signal at 37V-GHz and the ability to acquire daily data regardless of clouds or darkness make the dataset ideal for studying melt dynamics in both hemispheres. A 24-year (1988–2011 time series of annual Tb histograms was constructed to (1 characterize and assess temporal and spatial trends in melt patterns, (2 determine years of anomalous Tb distribution, and (3 investigate potential contributing factors. Distance from coast and temperature were key factors influencing melt. Years of high percentage of positive Tb anomalies were associated with relatively higher stream discharge (e.g., Copper and Mendenhall Rivers, Alaska, USA and Rio Baker, Chile. The characterization of melt over broad spatial domains and a multi-decadal time period offers a more comprehensive picture of the changing cryosphere and provides a baseline from which to assess future change.

  19. Using SMOS brightness temperature and derived surface-soil moisture to characterize surface conditions and validate land surface models.

    Science.gov (United States)

    Polcher, Jan; Barella-Ortiz, Anaïs; Piles, Maria; Gelati, Emiliano; de Rosnay, Patricia

    2017-04-01

    The SMOS satellite, operated by ESA, observes the surface in the L-band. On continental surface these observations are sensitive to moisture and in particular surface-soil moisture (SSM). In this presentation we will explore how the observations of this satellite can be exploited over the Iberian Peninsula by comparing its results with two land surface models : ORCHIDEE and HTESSEL. Measured and modelled brightness temperatures show a good agreement in their temporal evolution, but their spatial structures are not consistent. An empirical orthogonal function analysis of the brightness temperature's error identifies a dominant structure over the south-west of the Iberian Peninsula which evolves during the year and is maximum in autumn and winter. Hypotheses concerning forcing-induced biases and assumptions made in the radiative transfer model are analysed to explain this inconsistency, but no candidate is found to be responsible for the weak spatial correlations. The analysis of spatial inconsistencies between modelled and measured TBs is important, as these can affect the estimation of geophysical variables and TB assimilation in operational models, as well as result in misleading validation studies. When comparing the surface-soil moisture of the models with the product derived operationally by ESA from SMOS observations similar results are found. The spatial correlation over the IP between SMOS and ORCHIDEE SSM estimates is poor (ρ 0.3). A single value decomposition (SVD) analysis of rainfall and SSM shows that the co-varying patterns of these variables are in reasonable agreement between both products. Moreover the first three SVD soil moisture patterns explain over 80% of the SSM variance simulated by the model while the explained fraction is only 52% of the remotely sensed values. These results suggest that the rainfall-driven soil moisture variability may not account for the poor spatial correlation between SMOS and ORCHIDEE products. Other reasons have to

  20. Soil hydraulic parameters and surface soil moisture of a tilled bare soil plot inversely derived from l-band brightness temperatures

    KAUST Repository

    Dimitrov, Marin

    2014-01-01

    We coupled a radiative transfer model and a soil hydrologic model (HYDRUS 1D) with an optimization routine to derive soil hydraulic parameters, surface roughness, and soil moisture of a tilled bare soil plot using measured brightness temperatures at 1.4 GHz (L-band), rainfall, and potential soil evaporation. The robustness of the approach was evaluated using five 28-d data sets representing different meteorological conditions. We considered two soil hydraulic property models: the unimodal Mualem-van Genuchten and the bimodal model of Durner. Microwave radiative transfer was modeled by three different approaches: the Fresnel equation with depth-averaged dielectric permittivity of either 2-or 5-cm-thick surface layers and a coherent radiative transfer model (CRTM) that accounts for vertical gradients in dielectric permittivity. Brightness temperatures simulated by the CRTM and the 2-cm-layer Fresnel model fitted well to the measured ones. L-band brightness temperatures are therefore related to the dielectric permittivity and soil moisture in a 2-cm-thick surface layer. The surface roughness parameter that was derived from brightness temperatures using inverse modeling was similar to direct estimates from laser profiler measurements. The laboratory-derived water retention curve was bimodal and could be retrieved consistently for the different periods from brightness temperatures using inverse modeling. A unimodal soil hydraulic property function underestimated the hydraulic conductivity near saturation. Surface soil moisture contents simulated using retrieved soil hydraulic parameters were compared with in situ measurements. Depth-specific calibration relations were essential to derive soil moisture from near-surface installed sensors. © Soil Science Society of America 5585 Guilford Rd., Madison, WI 53711 USA.

  1. Blending bias impacts the host halo masses derived from a cross-correlation analysis of bright submillimetre galaxies

    Science.gov (United States)

    Cowley, William I.; Lacey, Cedric G.; Baugh, Carlton M.; Cole, Shaun; Wilkinson, Aaron

    2017-08-01

    Placing bright submillimetre galaxies (SMGs) within the broader context of galaxy formation and evolution requires accurate measurements of their clustering, which can constrain the masses of their host dark matter haloes. Recent work has shown that the clustering measurements of these galaxies may be affected by a 'blending bias', which results in the angular correlation function of the sources extracted from single-dish imaging surveys being boosted relative to that of the underlying galaxies. This is due to confusion introduced by the coarse angular resolution of the single-dish telescope and could lead to the inferred halo masses being significantly overestimated. We investigate the extent to which this bias affects the measurement of the correlation function of SMGs when it is derived via a cross-correlation with a more abundant galaxy population. We find that the blending bias is essentially the same as in the autocorrelation case and conclude that the best way to reduce its effects is to calculate the angular correlation function using SMGs in narrow redshift bins. Blending bias causes the inferred host halo masses of the SMGs to be overestimated by a factor of ∼6 when a redshift interval of δz = 3 is used. However, this reduces to a factor of ∼2 for δz = 0.5. The broadening of photometric redshift probability distributions with increasing redshift can therefore impart a mild halo 'downsizing' effect on to the inferred host halo masses, though this trend is not as strong as seen in recent observational studies.

  2. Evaluation of terrestrial photogrammetric point clouds derived from thermal imagery

    Science.gov (United States)

    Metcalf, Jeremy P.; Olsen, Richard C.

    2016-05-01

    Computer vision and photogrammetric techniques have been widely applied to digital imagery producing high density 3D point clouds. Using thermal imagery as input, the same techniques can be applied to infrared data to produce point clouds in 3D space, providing surface temperature information. The work presented here is an evaluation of the accuracy of 3D reconstruction of point clouds produced using thermal imagery. An urban scene was imaged over an area at the Naval Postgraduate School, Monterey, CA, viewing from above as with an airborne system. Terrestrial thermal and RGB imagery were collected from a rooftop overlooking the site using a FLIR SC8200 MWIR camera and a Canon T1i DSLR. In order to spatially align each dataset, ground control points were placed throughout the study area using Trimble R10 GNSS receivers operating in RTK mode. Each image dataset is processed to produce a dense point cloud for 3D evaluation.

  3. Su Lyncis, a Hard X-Ray Bright M Giant: Clues Point to a Large Hidden Population of Symbiotic Stars

    Science.gov (United States)

    Mukai, K.; Luna, G. J. M.; Cusumano, G.; Segreto, A.; Munari, U.; Sokoloski, J. L.; Lucy, A. B.; Nelson, T.; Nunez, N. E.

    2016-01-01

    Symbiotic star surveys have traditionally relied almost exclusively on low resolution optical spectroscopy. However, we can obtain a more reliable estimate of their total Galactic population by using all available signatures of the symbiotic phenomenon. Here we report the discovery of a hard X-ray source, 4PBC J0642.9+5528, in the Swift hard X-ray all-sky survey, and identify it with a poorly studied red giant, SU Lyn, using pointed Swift observations and ground-based optical spectroscopy. The X-ray spectrum, the optical to UV spectrum, and the rapid UV variability of SU Lyn are all consistent with our interpretation that it is a symbiotic star containing an accreting white dwarf. The symbiotic nature of SU Lyn went unnoticed until now, because it does not exhibit emission lines strong enough to be obvious in low resolution spectra. We argue that symbiotic stars without shell-burning have weak emission lines, and that the current lists of symbiotic stars are biased in favor of shell-burning systems. We conclude that the true population of symbiotic stars has been underestimated, potentially by a large factor.

  4. Nearly Ternary Quadratic Higher Derivations on Non-Archimedean Ternary Banach Algebras: A Fixed Point Approach

    Directory of Open Access Journals (Sweden)

    M. Eshaghi Gordji

    2011-01-01

    Full Text Available We investigate the stability and superstability of ternary quadratic higher derivations in non-Archimedean ternary algebras by using a version of fixed point theorem via quadratic functional equation.

  5. Single Particle Dynamic Imaging and Fe3+ Sensing with Bright Carbon Dots Derived from Bovine Serum Albumin Proteins

    Science.gov (United States)

    Yang, Qingxiu; Wei, Lin; Zheng, Xuanfang; Xiao, Lehui

    2015-01-01

    In this work, we demonstrated a convenient and green strategy for the synthesis of highly luminescent and water-soluble carbon dots (Cdots) by carbonizing carbon precursors, i.e., Bovine serum albumin (BSA) nanoparticles, in water solution. Without post surface modification, the as-synthesized Cdots exhibit fluorescence quantum yield (Q.Y.) as high as 34.8% and display superior colloidal stability not only in concentrated salt solutions (e.g. 2 M KCl) but also in a wide range of pH solutions. According to the FT-IR measurements, the Cdots contain many carboxyl groups, providing a versatile route for further chemical and biological functionalization. Through conjugation of Cdots with the transacting activator of transcription (TAT) peptide (a kind of cell penetration peptide (CPP)) derived from human immunodeficiency virus (HIV), it is possible to directly monitor the dynamic interactions of CPP with living cell membrane at single particle level. Furthermore, these Cdots also exhibit a dosage-dependent selectivity toward Fe3+ among other metal ions, including K+, Na+, Mg2+, Hg2+, Co2+, Cu2+, Pb2+ and Al3+. We believed that the Cdots prepared by this strategy would display promising applications in various areas, including analytical chemistry, nanomedicine, biochemistry and so on. PMID:26634992

  6. BrightFocus Foundation

    Science.gov (United States)

    ... sooner. More science news Help us find a cure. Give to BrightFocus BrightFocus Updates BrightFocus Foundation Lauds Bill Gates Alzheimer’s Initiative “BrightFocus Foundation lauds today’s historic announcement by ...

  7. Lightness, brightness, and anchoring.

    Science.gov (United States)

    Anderson, Barton L; Whitbread, Michael; de Silva, Chamila

    2014-08-07

    The majority of work in lightness perception has evaluated the perception of lightness using flat, matte, two-dimensional surfaces. In such contexts, the amount of light reaching the eye contains a conflated mixture of the illuminant and surface lightness. A fundamental puzzle of lightness perception is understanding how it is possible to experience achromatic surfaces as specific achromatic shades in the face of this ambiguity. It has been argued that the perception of lightness in such contexts implies that the visual system imposes an "anchoring rule" whereby a specific relative luminance (the highest) serves as a fixed point in the mapping of image luminance onto the lightness scale ("white"). We conducted a series of experiments to explicitly test this assertion in contexts where this mapping seemed most unlikely-namely, low-contrast images viewed in dim illumination. Our results provide evidence that the computational ambiguity in mapping luminance onto lightness is reflected in perceptual experience. The perception of the highest luminance in a two-dimensional Mondrian display varied monotonically with its brightness, ranging from midgray to white. Similar scaling occurred for the lowest luminance and, by implication, all other luminance values. We conclude that the conflation between brightness and lightness in two-dimensional Mondrian displays is reflected in perception and find no support for the claim that any specific relative luminance value acts as a fixed anchor point in this mapping function. © 2014 ARVO.

  8. Georeferencing UAS Derivatives Through Point Cloud Registration with Archived Lidar Datasets

    Science.gov (United States)

    Magtalas, M. S. L. Y.; Aves, J. C. L.; Blanco, A. C.

    2016-10-01

    Georeferencing gathered images is a common step before performing spatial analysis and other processes on acquired datasets using unmanned aerial systems (UAS). Methods of applying spatial information to aerial images or their derivatives is through onboard GPS (Global Positioning Systems) geotagging, or through tying of models through GCPs (Ground Control Points) acquired in the field. Currently, UAS (Unmanned Aerial System) derivatives are limited to meter-levels of accuracy when their generation is unaided with points of known position on the ground. The use of ground control points established using survey-grade GPS or GNSS receivers can greatly reduce model errors to centimeter levels. However, this comes with additional costs not only with instrument acquisition and survey operations, but also in actual time spent in the field. This study uses a workflow for cloud-based post-processing of UAS data in combination with already existing LiDAR data. The georeferencing of the UAV point cloud is executed using the Iterative Closest Point algorithm (ICP). It is applied through the open-source CloudCompare software (Girardeau-Montaut, 2006) on a `skeleton point cloud'. This skeleton point cloud consists of manually extracted features consistent on both LiDAR and UAV data. For this cloud, roads and buildings with minimal deviations given their differing dates of acquisition are considered consistent. Transformation parameters are computed for the skeleton cloud which could then be applied to the whole UAS dataset. In addition, a separate cloud consisting of non-vegetation features automatically derived using CANUPO classification algorithm (Brodu and Lague, 2012) was used to generate a separate set of parameters. Ground survey is done to validate the transformed cloud. An RMSE value of around 16 centimeters was found when comparing validation data to the models georeferenced using the CANUPO cloud and the manual skeleton cloud. Cloud-to-cloud distance computations of

  9. RNS derivation of N-point disk amplitudes from the revisited S-matrix approach

    Energy Technology Data Exchange (ETDEWEB)

    Barreiro, Luiz Antonio, E-mail: luiz.a.barreiro@gmail.com [Departamento de Física, UNESP, Rio Claro, São Paulo (Brazil); Instituto de Matemática e Computação, Universidade Federal de Itajubá, Itajubá, Minas Gerais (Brazil); Medina, Ricardo, E-mail: rmedina50@gmail.com [Instituto de Matemática e Computação, Universidade Federal de Itajubá, Itajubá, Minas Gerais (Brazil)

    2014-09-15

    Recently, in [7] we proposed a revisited S-matrix approach to efficiently find the bosonic terms of the open superstring low energy effective lagrangian (OSLEEL). This approach allows to compute the α{sup ′N} terms of the OSLEEL using open superstring n-point amplitudes in which n is considerably lower than (N+2) (which is the order of the required amplitude to obtain those α{sup ′N} terms by means of the conventional S-matrix approach). In this work we use our revisited S-matrix approach to examine the structure of the scattering amplitudes, arriving at a closed form for them. This is a RNS derivation of the formula first found by Mafra, Schlotterer and Stieberger [21], using the pure spinor formalism. We have succeeded doing this for the 5, 6 and 7-point amplitudes. In order to achieve these results we have done a careful analysis of the kinematical structure of the amplitudes, finding as a by-product a purely kinematical derivation of the BCJ relations (for N=4,5,6 and 7). Also, following the spirit of the revisited S-matrix approach, we have found the α{sup ′} expansions for these amplitudes up to α{sup ′6} order in some cases, by only using the well known open superstring 4-point amplitude, cyclic symmetry and tree level unitarity: we have not needed to compute any numerical series or any integral involving polylogarithms, at any moment.

  10. Systematic Derivation of Noether Point Symmetries in Special Relativistic Field Theories

    CERN Document Server

    Haas, Fernando

    2016-01-01

    A didactic and systematic derivation of Noether point symmetries and conserved currents is put forward in special relativistic field theories, without a priori assumptions about the transformation laws. Given the Lagrangian density, the invariance condition develops as a set of partial differential equations determining the symmetry transformation. The solution is provided in the case of real scalar, complex scalar, free electromagnetic, and charged electromagnetic fields. Besides the usual conservation laws, a less popular symmetry is analyzed: the symmetry associated with the linear superposition of solutions, whenever applicable. The role of gauge invariance is emphasized. The case of the charged scalar particle under external electromagnetic fields is considered, and the accompanying Noether point symmetries determined.

  11. Assessing the consistency of UAV-derived point clouds and images acquired at different altitudes

    Science.gov (United States)

    Ozcan, O.

    2016-12-01

    Unmanned Aerial Vehicles (UAVs) offer several advantages in terms of cost and image resolution compared to terrestrial photogrammetry and satellite remote sensing system. Nowadays, UAVs that bridge the gap between the satellite scale and field scale applications were initiated to be used in various application areas to acquire hyperspatial and high temporal resolution imageries due to working capacity and acquiring in a short span of time with regard to conventional photogrammetry methods. UAVs have been used for various fields such as for the creation of 3-D earth models, production of high resolution orthophotos, network planning, field monitoring and agricultural lands as well. Thus, geometric accuracy of orthophotos and volumetric accuracy of point clouds are of capital importance for land surveying applications. Correspondingly, Structure from Motion (SfM) photogrammetry, which is frequently used in conjunction with UAV, recently appeared in environmental sciences as an impressive tool allowing for the creation of 3-D models from unstructured imagery. In this study, it was aimed to reveal the spatial accuracy of the images acquired from integrated digital camera and the volumetric accuracy of Digital Surface Models (DSMs) which were derived from UAV flight plans at different altitudes using SfM methodology. Low-altitude multispectral overlapping aerial photography was collected at the altitudes of 30 to 100 meters and georeferenced with RTK-GPS ground control points. These altitudes allow hyperspatial imagery with the resolutions of 1-5 cm depending upon the sensor being used. Preliminary results revealed that the vertical comparison of UAV-derived point clouds with respect to GPS measurements pointed out an average distance at cm-level. Larger values are found in areas where instantaneous changes in surface are present.

  12. Integration of Image Data for Refining Building Boundaries Derived from Point Clouds

    Science.gov (United States)

    Perera, S. N.; Hetti Arachchige, N.; Schneider, D.

    2014-08-01

    Geometrically and topologically correct 3D building models are required to satisfy with new demands such as 3D cadastre, map updating, and decision making. More attention on building reconstruction has been paid using Airborne Laser Scanning (ALS) point cloud data. The planimetric accuracy of roof outlines, including step-edges is questionable in building models derived from only point clouds. This paper presents a new approach for the detection of accurate building boundaries by merging point clouds acquired by ALS and aerial photographs. It comprises two major parts: reconstruction of initial roof models from point clouds only, and refinement of their boundaries. A shortest closed circle (graph) analysis method is employed to generate building models in the first step. Having the advantages of high reliability, this method provides reconstruction without prior knowledge of primitive building types even when complex height jumps and various types of building roof are available. The accurate position of boundaries of the initial models is determined by the integration of the edges extracted from aerial photographs. In this process, scene constraints defined based on the initial roof models are introduced as the initial roof models are representing explicit unambiguous geometries about the scene. Experiments were conducted using the ISPRS benchmark test data. Based on test results, we show that the proposed approach can reconstruct 3D building models with higher geometrical (planimetry and vertical) and topological accuracy.

  13. Address Points, This is a point feature class depicting site access points for every address in Washburn County. Points were derived from 2004 6inch Orthophotos and field survey/GSP efforts. Attributes included in this data set include; road name, suffix, address numbe, Published in 2008, 1:12000 (1in=1000ft) scale, Washburn County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Address Points dataset current as of 2008. This is a point feature class depicting site access points for every address in Washburn County. Points were derived from...

  14. An Attempt to Derive the epsilon Equation from a Two-Point Closure

    Science.gov (United States)

    Canuto, V. M.; Cheng, Y.; Howard, A. M.

    2010-01-01

    The goal of this paper is to derive the equation for the turbulence dissipation rate epsilon for a shear-driven flow. In 1961, Davydov used a one-point closure model to derive the epsilon equation from first principles but the final result contained undetermined terms and thus lacked predictive power. Both in 1987 and in 2001, attempts were made to derive the epsilon equation from first principles using a two-point closure, but their methods relied on a phenomenological assumption. The standard practice has thus been to employ a heuristic form of the equation that contains three empirical ingredients: two constants, c(sub 1 epsilon), and c(sub 2 epsilon), and a diffusion term D(sub epsilon) In this work, a two-point closure is employed, yielding the following results: 1) the empirical constants get replaced by c(sub 1), c(sub 2), which are now functions of Kappa and epsilon; 2) c(sub 1) and c(sub 2) are not independent because a general relation between the two that are valid for any Kappa and epsilon are derived; 3) c(sub 1), c(sub 2) become constant with values close to the empirical values c(sub 1 epsilon), c(sub epsilon 2), (i.e., homogenous flows); and 4) the empirical form of the diffusion term D(sub epsilon) is no longer needed because it gets substituted by the Kappa-epsilon dependence of c(sub 1), c(sub 2), which plays the role of the diffusion, together with the diffusion of the turbulent kinetic energy D(sub Kappa), which now enters the new equation (i.e., inhomogeneous flows). Thus, the three empirical ingredients c(sub 1 epsilon), c(sub epsilon 2), D (sub epsilon)are replaced by a single function c(sub 1)(Kappa, epsilon ) or c(sub 2)(Kappa, epsilon ), plus a D(sub Kappa)term. Three tests of the new equation for epsilon are presented: one concerning channel flow and two concerning the shear-driven planetary boundary layer (PBL).

  15. Stability and Superstability of Generalized (, -Derivations in Non-Archimedean Algebras: Fixed Point Theorem via the Additive Cauchy Functional Equation

    Directory of Open Access Journals (Sweden)

    M. Eshaghi Gordji

    2011-01-01

    mapping ∶→ is called a (,-derivation if (=((+(( for all ,∈. Moreover, an additive mapping ∶→ is said to be a generalized (,-derivation if there exists a (,-derivation ∶→ such that (=((+(( for all ,∈. In this paper, we investigate the superstability of generalized (,-derivations in non-Archimedean algebras by using a version of fixed point theorem via Cauchy’s functional equation.

  16. On the Quality of Point-Clouds Derived from Sfm-Photogrammetry Applied to UAS Imagery

    Science.gov (United States)

    Carbonneau, P.; James, T.

    2014-12-01

    Structure from Motion photogrammetry (SfM-photogrammetry) recently appeared in environmental sciences as an impressive tool allowing for the creation of topographic data from unstructured imagery. Several authors have tested the performance of SfM-photogrammetry vs that of TLS or dGPS. Whilst the initial results were very promising, there is currently a growing awareness that systematic deformations occur in DEMs and point-clouds derived from SfM-photogrammetry. Notably, some authors have identified a systematic doming manifest as an increasing error vs distance to the model centre. Simulation studies have confirmed that this error is due to errors in the calibration of camera distortions. This work aims to further investigate these effects in the presence of real data. We start with a dataset of 220 images acquired from a sUAS. After obtaining an initial self-calibration of the camera lens with Agisoft Photoscan, our method consists in applying systematic perturbations to 2 key lens parameters: Focal length and the k1 distortion parameter. For each perturbation, a point-cloud was produced and compared to LiDAR data. After deriving the mean and standard deviation of the error residuals (ɛ), a 2nd order polynomial surface was fitted to the errors point-cloud and the peak ɛ defined as the mathematical extrema of this surface. The results are presented in figure 1. This figure shows that lens perturbations can induce a range of errors with systematic behaviours. Peak ɛ is primarily controlled by K1 with a secondary control exerted by the focal length. These results allow us to state that: To limit the peak ɛ to 10cm, the K1 parameter must be calibrated to within 0.00025 and the focal length to within 2.5 pixels (≈10 µm). This level of calibration accuracy can only be achieved with proper design of image acquisition and control network geometry. Our main point is therefore that SfM is not a bypass to a rigorous and well-informed photogrammetric approach. Users

  17. Hospitals - HOSPITALS_HAZUS_IN: Hospitals and Clinics in Indiana, Derived from HAZUS (Federal Emergency Management Agency, Point Shapefile)

    Data.gov (United States)

    NSGIC State | GIS Inventory — HOSPITALS_HAZUS_IN is a point shapefile that shows locations of hospitals and clinics in Indiana. HOSPITALS_HAZUS_IN was derived from the shapefile named "HOSPITAL."...

  18. Relativistic derivations of the electric and magnetic fields generated by an electric point charge moving with constant velocity

    OpenAIRE

    Rothenstein, Bernhard; Popescu, Stefan; Spix, George J.

    2006-01-01

    We propose a simple relativistic derivation of the electric and the magnetic fields generated by an electric point charge moving with constant velocity. Our approach is based on the radar detection of the point space coordinates where the fields are measured. The same equations were previously derived in a relatively complicated way2 based exclusively on general electromagnetic field equations and without making use of retarded potentials or relativistic equations

  19. DERIVING 3D POINT CLOUDS FROM TERRESTRIAL PHOTOGRAPHS - COMPARISON OF DIFFERENT SENSORS AND SOFTWARE

    Directory of Open Access Journals (Sweden)

    R. Niederheiser

    2016-06-01

    Full Text Available Terrestrial photogrammetry nowadays offers a reasonably cheap, intuitive and effective approach to 3D-modelling. However, the important choice, which sensor and which software to use is not straight forward and needs consideration as the choice will have effects on the resulting 3D point cloud and its derivatives. We compare five different sensors as well as four different state-of-the-art software packages for a single application, the modelling of a vegetated rock face. The five sensors represent different resolutions, sensor sizes and price segments of the cameras. The software packages used are: (1 Agisoft PhotoScan Pro (1.16, (2 Pix4D (2.0.89, (3 a combination of Visual SFM (V0.5.22 and SURE (1.2.0.286, and (4 MicMac (1.0. We took photos of a vegetated rock face from identical positions with all sensors. Then we compared the results of the different software packages regarding the ease of the workflow, visual appeal, similarity and quality of the point cloud. While PhotoScan and Pix4D offer the user-friendliest workflows, they are also “black-box” programmes giving only little insight into their processing. Unsatisfying results may only be changed by modifying settings within a module. The combined workflow of Visual SFM, SURE and CloudCompare is just as simple but requires more user interaction. MicMac turned out to be the most challenging software as it is less user-friendly. However, MicMac offers the most possibilities to influence the processing workflow. The resulting point-clouds of PhotoScan and MicMac are the most appealing.

  20. Burkina Faso - BRIGHT II

    Data.gov (United States)

    Millennium Challenge Corporation — Millennium Challenge Corporation hired Mathematica Policy Research to conduct an independent evaluation of the BRIGHT II program. The three main research questions...

  1. Computationally derived points of fragility of a human cascade are consistent with current therapeutic strategies.

    Directory of Open Access Journals (Sweden)

    Deyan Luan

    2007-07-01

    Full Text Available The role that mechanistic mathematical modeling and systems biology will play in molecular medicine and clinical development remains uncertain. In this study, mathematical modeling and sensitivity analysis were used to explore the working hypothesis that mechanistic models of human cascades, despite model uncertainty, can be computationally screened for points of fragility, and that these sensitive mechanisms could serve as therapeutic targets. We tested our working hypothesis by screening a model of the well-studied coagulation cascade, developed and validated from literature. The predicted sensitive mechanisms were then compared with the treatment literature. The model, composed of 92 proteins and 148 protein-protein interactions, was validated using 21 published datasets generated from two different quiescent in vitro coagulation models. Simulated platelet activation and thrombin generation profiles in the presence and absence of natural anticoagulants were consistent with measured values, with a mean correlation of 0.87 across all trials. Overall state sensitivity coefficients, which measure the robustness or fragility of a given mechanism, were calculated using a Monte Carlo strategy. In the absence of anticoagulants, fluid and surface phase factor X/activated factor X (fX/FXa activity and thrombin-mediated platelet activation were found to be fragile, while fIX/FIXa and fVIII/FVIIIa activation and activity were robust. Both anti-fX/FXa and direct thrombin inhibitors are important classes of anticoagulants; for example, anti-fX/FXa inhibitors have FDA approval for the prevention of venous thromboembolism following surgical intervention and as an initial treatment for deep venous thrombosis and pulmonary embolism. Both in vitro and in vivo experimental evidence is reviewed supporting the prediction that fIX/FIXa activity is robust. When taken together, these results support our working hypothesis that computationally derived points of

  2. Stare and chase of space debris targets using real-time derived pointing data

    Science.gov (United States)

    Steindorfer, Michael A.; Kirchner, Georg; Koidl, Franz; Wang, Peiyuan; Antón, Alfredo; Fernández Sánchez, Jaime; Merz, Klaus

    2017-09-01

    We successfully demonstrate Stare & Chase: Space debris laser ranging to uncooperative targets has been achieved without a priori knowledge of any orbital information. An analog astronomy CCD with a standard objective, piggyback mounted on our 50 cm Graz SLR receive telescope, 'stares' into the sky in a fixed direction. The CCD records the stellar background within a field of view of approx. 7°. From the stellar X/Y positions on the sensor a plate solving algorithm determines the pointing data of the image center with an accuracy of approx. 15 arc seconds. If a sunlit target passes through this field of view, its equatorial coordinates are calculated, stored and a Consolidated Prediction Format (CPF) file is created in near real time. The derived CPF data is used to start laser ranging ('chase' the object) within the same pass to retrieve highly accurate distance information. A comparison of Stare & Chase CPFs with standard TLE predictions shows the possibilities and limits of this method.

  3. Deriving 3d point clouds from terrestrial photographs comparison of different sensors and software

    DEFF Research Database (Denmark)

    Niederheiser, Robert; Mokros, Martin; Lange, Julia

    2016-01-01

    Terrestrial photogrammetry nowadays offers a reasonably cheap, intuitive and effective approach to 3D-modelling. However, the important choice, which sensor and which software to use is not straight forward and needs consideration as the choice will have effects on the resulting 3D point cloud...... and its derivatives.We compare five different sensors as well as four different state-of-the-art software packages for a single application, the modelling of a vegetated rock face. The five sensors represent different resolutions, sensor sizes and price segments of the cameras. The software packages used...... are: (1) Agisoft PhotoScan Pro (1.16), (2) Pix4D (2.0.89), (3) a combination of Visual SFM (V0.5.22) and SURE (1.2.0.286), and (4) MicMac (1.0). We took photos of a vegetated rock face from identical positions with all sensors. Then we compared the results of the different software packages regarding...

  4. Four points function fitted and first derivative procedure for determining the end points in potentiometric titration curves: statistical analysis and method comparison.

    Science.gov (United States)

    Kholeif, S A

    2001-06-01

    A new method that belongs to the differential category for determining the end points from potentiometric titration curves is presented. It uses a preprocess to find first derivative values by fitting four data points in and around the region of inflection to a non-linear function, and then locate the end point, usually as a maximum or minimum, using an inverse parabolic interpolation procedure that has an analytical solution. The behavior and accuracy of the sigmoid and cumulative non-linear functions used are investigated against three factors. A statistical evaluation of the new method using linear least-squares method validation and multifactor data analysis are covered. The new method is generally applied to symmetrical and unsymmetrical potentiometric titration curves, and the end point is calculated using numerical procedures only. It outperforms the "parent" regular differential method in almost all factors levels and gives accurate results comparable to the true or estimated true end points. Calculated end points from selected experimental titration curves compatible with the equivalence point category of methods, such as Gran or Fortuin, are also compared with the new method.

  5. Helmholtz bright and boundary solitons

    Energy Technology Data Exchange (ETDEWEB)

    Christian, J M [Joule Physics Laboratory, School of Computing, Science and Engineering, Institute for Materials Research, University of Salford, Salford M5 4WT (United Kingdom); McDonald, G S [Joule Physics Laboratory, School of Computing, Science and Engineering, Institute for Materials Research, University of Salford, Salford M5 4WT (United Kingdom); Chamorro-Posada, P [Departmento de TeorIa de la Senal y Comunicaciones e IngenierIa Telematica, Universidad de Valladolid, ETSI Telecomunicacion, Campus Miguel Delibes s/n, 47011 Valladolid (Spain)

    2007-02-16

    We report, for the first time, exact analytical boundary solitons of a generalized cubic-quintic nonlinear Helmholtz (NLH) equation. These solutions have a linked-plateau topology that is distinct from conventional dark soliton solutions; their amplitude and intensity distributions are spatially delocalized and connect regions of finite and zero wave-field disturbances (suggesting also the classification as 'edge solitons'). Extensive numerical simulations compare the stability properties of recently derived Helmholtz bright solitons, for this type of polynomial nonlinearity, to those of the new boundary solitons. The latter are found to possess a remarkable stability characteristic, exhibiting robustness against perturbations that would otherwise lead to the destabilizing of their bright-soliton counterparts.

  6. Relevant knowledge concerning the derivative concept for students of economics - A normative point of view and students' perspectives

    OpenAIRE

    Feudel, Frank

    2016-01-01

    International audience; The concept of the derivative plays a major role in economics. A proper understanding of the concept and its application in economics is therefore important for students of economics. In this paper two perspectives on the relevant knowledge concerning the derivative for students of economics are presented: a normative point of view based on literature and the students' perspectives identified in an empirical study. It can be seen that the students' perspectives differe...

  7. Address Points, County wide address points derived from parcel layer and updated and amended by Address Coordinator through plat and maintenance processes., Published in Not Provided, Durham City/County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Address Points dataset current as of unknown. County wide address points derived from parcel layer and updated and amended by Address Coordinator through plat and...

  8. Point Cloud Derived Fromvideo Frames: Accuracy Assessment in Relation to Terrestrial Laser Scanningand Digital Camera Data

    Science.gov (United States)

    Delis, P.; Zacharek, M.; Wierzbicki, D.; Grochala, A.

    2017-02-01

    The use of image sequences in the form of video frames recorded on data storage is very useful in especially when working with large and complex structures. Two cameras were used in this study: Sony NEX-5N (for the test object) and Sony NEX-VG10 E (for the historic building). In both cases, a Sony α f = 16 mm fixed focus wide-angle lens was used. Single frames with sufficient overlap were selected from the video sequence using an equation for automatic frame selection. In order to improve the quality of the generated point clouds, each video frame underwent histogram equalization and image sharpening. Point clouds were generated from the video frames using the SGM-like image matching algorithm. The accuracy assessment was based on two reference point clouds: the first from terrestrial laser scanning and the second generated based on images acquired using a high resolution camera, the NIKON D800. The performed research has shown, that highest accuracies are obtained for point clouds generated from video frames, for which a high pass filtration and histogram equalization had been performed. Studies have shown that to obtain a point cloud density comparable to TLS, an overlap between subsequent video frames must be 85 % or more. Based on the point cloud generated from video data, a parametric 3D model can be generated. This type of the 3D model can be used in HBIM construction.

  9. High Brightness OLED Lighting

    Energy Technology Data Exchange (ETDEWEB)

    Spindler, Jeffrey [OLEDWorks LLC; Kondakova, Marina [OLEDWorks LLC; Boroson, Michael [OLEDWorks LLC; Hamer, John [OLEDWorks LLC

    2016-05-25

    In this work we describe the technology developments behind our current and future generations of high brightness OLED lighting panels. We have developed white and amber OLEDs with excellent performance based on the stacking approach. Current products achieve 40-60 lm/W, while future developments focus on achieving 80 lm/W or higher.

  10. Prediction uncertainty of plume characteristics derived from a small number of measuring points

    Science.gov (United States)

    French, H. K.; van der Zee, S. E. A. T. M.; Leijnse, A.

    A small number of measuring points may inflict a bias on the characterisation of flow and transport based on field experiments in the unsaturated zone. Simulation of pure advective transport of a Gaussian plume through a setup of 30 regularly placed measuring points revealed regular temporal fluctuations about the real spatial moments. An irregular setup predicted both irregular fluctuations and larger discrepancies from the real value. From these considerations, a regular setup is recommended. Spatial moments were sensitive to the plume size relative to the distance between individual measuring points. To reduce prediction errors of the variance, the distance between the measuring points should be less than twice the standard deviation of the examined plume. The total size of the setup should cover several standard deviations of the plume to avoid mass being lost from the monitored area. Numerical simulations of a dispersing plume (comparing calculations based on 9000 nodes with 30 measuring points) revealed that vertical and horizontal centres of mass were predicted well at all degrees of heterogeneity, and the same was the case for horizontal variances. Vertical variances were more susceptible to prediction errors, but estimates were of the same order of magnitude as the real values. Résumé Lorsque l'on cherche à caractériser l'écoulement et le transport à partir d'expériences de terrain dans la zone saturée, il arrive qu'un petit nombre de points introduisent un biais. La simulation d'un transport purement advectif d'un panache gaussien au travers d'un ensemble de 30 points de mesures espacés régulièrement fait apparaître des variations temporelles régulières autour des moments spatiaux réels. Un ensemble irrégulier conduit à prédire à la fois des variations irrégulières et de plus grandes divergences par rapport à la valeur réelle. A partir de ces constations, un ensemble régulier est recommandé. Les moments spatiaux sont apparus

  11. The brightness of colour.

    Directory of Open Access Journals (Sweden)

    David Corney

    Full Text Available The perception of brightness depends on spatial context: the same stimulus can appear light or dark depending on what surrounds it. A less well-known but equally important contextual phenomenon is that the colour of a stimulus can also alter its brightness. Specifically, stimuli that are more saturated (i.e. purer in colour appear brighter than stimuli that are less saturated at the same luminance. Similarly, stimuli that are red or blue appear brighter than equiluminant yellow and green stimuli. This non-linear relationship between stimulus intensity and brightness, called the Helmholtz-Kohlrausch (HK effect, was first described in the nineteenth century but has never been explained. Here, we take advantage of the relative simplicity of this 'illusion' to explain it and contextual effects more generally, by using a simple Bayesian ideal observer model of the human visual ecology. We also use fMRI brain scans to identify the neural correlates of brightness without changing the spatial context of the stimulus, which has complicated the interpretation of related fMRI studies.Rather than modelling human vision directly, we use a Bayesian ideal observer to model human visual ecology. We show that the HK effect is a result of encoding the non-linear statistical relationship between retinal images and natural scenes that would have been experienced by the human visual system in the past. We further show that the complexity of this relationship is due to the response functions of the cone photoreceptors, which themselves are thought to represent an efficient solution to encoding the statistics of images. Finally, we show that the locus of the response to the relationship between images and scenes lies in the primary visual cortex (V1, if not earlier in the visual system, since the brightness of colours (as opposed to their luminance accords with activity in V1 as measured with fMRI.The data suggest that perceptions of brightness represent a robust

  12. Addressing scale dependence in roughness and morphometric statistics derived from point cloud data.

    Science.gov (United States)

    Buscombe, D.; Wheaton, J. M.; Hensleigh, J.; Grams, P. E.; Welcker, C. W.; Anderson, K.; Kaplinski, M. A.

    2015-12-01

    The heights of natural surfaces can be measured with such spatial density that almost the entire spectrum of physical roughness scales can be characterized, down to the morphological form and grain scales. With an ability to measure 'microtopography' comes a demand for analytical/computational tools for spatially explicit statistical characterization of surface roughness. Detrended standard deviation of surface heights is a popular means to create continuous maps of roughness from point cloud data, using moving windows and reporting window-centered statistics of variations from a trend surface. If 'roughness' is the statistical variation in the distribution of relief of a surface, then 'texture' is the frequency of change and spatial arrangement of roughness. The variance in surface height as a function of frequency obeys a power law. In consequence, roughness is dependent on the window size through which it is examined, which has a number of potential disadvantages: 1) the choice of window size becomes crucial, and obstructs comparisons between data; 2) if windows are large relative to multiple roughness scales, it is harder to discriminate between those scales; 3) if roughness is not scaled by the texture length scale, information on the spacing and clustering of roughness `elements' can be lost; and 4) such practice is not amenable to models describing the scattering of light and sound from rough natural surfaces. We discuss the relationship between roughness and texture. Some useful parameters which scale vertical roughness to characteristic horizontal length scales are suggested, with examples of bathymetric point clouds obtained using multibeam from two contrasting riverbeds, namely those of the Colorado River in Grand Canyon, and the Snake River in Hells Canyon. Such work, aside from automated texture characterization and texture segmentation, roughness and grain size calculation, might also be useful for feature detection and classification from point

  13. Parameterized approximation of lacunarity functions derived from airborne laser scanning point clouds of forested areas

    Science.gov (United States)

    Székely, Balázs; Kania, Adam; Varga, Katalin; Heilmeier, Hermann

    2017-04-01

    Lacunarity, a measure of the spatial distribution of the empty space is found to be a useful descriptive quantity of the forest structure. Its calculation, based on laser-scanned point clouds, results in a four-dimensional data set. The evaluation of results needs sophisticated tools and visualization techniques. To simplify the evaluation, it is straightforward to use approximation functions fitted to the results. The lacunarity function L(r), being a measure of scale-independent structural properties, has a power-law character. Previous studies showed that log(log(L(r))) transformation is suitable for analysis of spatial patterns. Accordingly, transformed lacunarity functions can be approximated by appropriate functions either in the original or in the transformed domain. As input data we have used a number of laser-scanned point clouds of various forests. The lacunarity distribution has been calculated along a regular horizontal grid at various (relative) elevations. The lacunarity data cube then has been logarithm-transformed and the resulting values became the input of parameter estimation at each point (point of interest, POI). This way at each POI a parameter set is generated that is suitable for spatial analysis. The expectation is that the horizontal variation and vertical layering of the vegetation can be characterized by this procedure. The results show that the transformed L(r) functions can be typically approximated by exponentials individually, and the residual values remain low in most cases. However, (1) in most cases the residuals may vary considerably, and (2) neighbouring POIs often give rather differing estimates both in horizontal and in vertical directions, of them the vertical variation seems to be more characteristic. In the vertical sense, the distribution of estimates shows abrupt changes at places, presumably related to the vertical structure of the forest. In low relief areas horizontal similarity is more typical, in higher relief areas

  14. Gel Point Suppression in RAFT Polymerization of Pure Acrylic Cross-Linker Derived from Soybean Oil.

    Science.gov (United States)

    Yan, Mengguo; Huang, Yuerui; Lu, Mingjia; Lin, Fang-Yi; Hernández, Nacú B; Cochran, Eric W

    2016-08-08

    Here we report the reversible addition-fragmentation chain transfer (RAFT) polymerization of acrylated epoxidized soybean oil (AESO), a cross-linker molecule, to high conversion (>50%) and molecular weight (>100 kDa) without macrogelation. Surprisingly, gelation is suppressed in this system far beyond the expectations predicated both on Flory-Stockmeyer theory and multiple other studies of RAFT polymerization featuring cross-linking moieties. By varying AESO and initiator concentrations, we show how intra- versus intermolecular cross-linking compete, yielding a trade-off between the degree of intramolecular linkages and conversion at gel point. We measured polymer chain characteristics, including molecular weight, chain dimensions, polydispersity, and intrinsic viscosity, using multidetector gel permeation chromatography and NMR to track polymerization kinetics. We show that not only the time and conversion at macrogelation, but also the chain architecture, is largely affected by these reaction conditions. At maximal AESO concentration, the gel point approaches that predicted by the Flory-Stockmeyer theory, and increases in an exponential fashion as the AESO concentration decreases. In the most dilute solutions, macrogelation cannot be detected throughout the entire reaction. Instead, cyclization/intramolecular cross-linking reactions dominate, leading to microgelation. This work is important, especially in that it demonstrates that thermoplastic rubbers could be produced based on multifunctional renewable feedstocks.

  15. CLEMENTINE LWIR BRIGHTNESS TEMPERATURE V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This volume contains the archive of Lunar brightness temperature data derived from images acquired by the Clementine Long Wavelength Infrared (LWIR) camera. The LWIR...

  16. Comparison of a UAV-derived point-cloud to Lidar data at Haig Glacier, Alberta, Canada

    Science.gov (United States)

    Bash, E. A.; Moorman, B.; Montaghi, A.; Menounos, B.; Marshall, S. J.

    2016-12-01

    The use of unmanned aerial vehicles (UAVs) is expanding rapidly in glaciological research as a result of technological improvements that make UAVs a cost-effective solution for collecting high resolution datasets with relative ease. The cost and difficult access traditionally associated with performing fieldwork in glacial environments makes UAVs a particularly attractive tool. In the small, but growing, body of literature using UAVs in glaciology the accuracy of UAV data is tested through the comparison of a UAV-derived DEM to measured control points. A field campaign combining simultaneous lidar and UAV flights over Haig Glacier in April 2015, provided the unique opportunity to directly compare UAV data to lidar. The UAV was a six-propeller Mikrokopter carrying a Panasonic Lumix DMC-GF1 camera with a 12 Megapixel Live MOS sensor and Lumix G 20 mm lens flown at a height of 90 m, resulting in sub-centimetre ground resolution per image pixel. Lidar data collection took place April 20, while UAV flights were conducted April 20-21. A set of 65 control points were laid out and surveyed on the glacier surface on April 19 and 21 using a RTK GPS with a vertical uncertainty of 5 cm. A direct comparison of lidar points to these control points revealed a 9 cm offset between the control points and the lidar points on average, but the difference changed distinctly from points collected on April 19 versus those collected April 21 (7 cm and 12 cm). Agisoft Photoscan was used to create a point-cloud from imagery collected with the UAV and CloudCompare was used to calculate the difference between this and the lidar point cloud, revealing an average difference of less than 17 cm. This field campaign also highlighted some of the benefits and drawbacks of using a rotary UAV for glaciological research. The vertical takeoff and landing capabilities, combined with quick responsiveness and higher carrying capacity, make the rotary vehicle favourable for high-resolution photos when

  17. HI Surface brightness mapping

    Science.gov (United States)

    Pen, Ue-Li; Staveley-Smith, Lister; Chang, Tzu-Ching; Peterson, Jeff; Bandura, Kevin

    2008-04-01

    We propose to scan the 2dF survey field with Parkes multibeam in driftscan mode to make a map to cross correlate with galaxy redshifts. This allows a statistical detection of HI large scale structure out to z=0.15. In this cross correlation, the HI in ALL galaxies contributes, not only the bright ones, which significantly boosts the sensitivity. The proposed 40 hours on the fields result in a forecasted 20 sigma detection. The survey volume is 10 million cubic megaparsec, which contain 10^15 solar masses of hydrogen.

  18. Analysis of LiDAR point data and derived elevation models for mapping and characterizing bouldery landforms

    Science.gov (United States)

    Maxwell, Aaron Edward

    This thesis assessed the viability of using LiDAR-derived elevation data in accurately mapping and characterizing bouldery geomorphic features in a study area in the Allegheny Mountains. This study showed that the ground returns classification process conducted by the Canaan Valley Institute (CVI) for their property using the TerraScan software generally removed 5 to 10 m scale local topographic variability and bouldery landforms in creating the CVI classified ground returns data. In open areas, last returns elevation and intensity data were successfully used in this study to map bouldery landforms in the study area. Identifying and describing boulders under a tree canopy required a relatively reliable ground classification of LiDAR points. This study's classifications conducted within Prologic LiDAR Explorer provided a more useful representation than the CVI classified ground data for mapping bouldery landforms and generalized rugged topography. Index overlay for likelihood of presence of bouldery landforms using supervised classified aerial imagery and LiDAR-derived parameters in a raster environment was explored as an alternative means of detecting bouldery landforms because hillshade imagery derived from CVI classified ground data were inadequate for mapping bouldery landforms.

  19. Increasing the brightness of light sources

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Ling

    2006-11-16

    , and Carambolas with different geometries and optical properties are used. A prototype five-point reflective Carambola was manufactured from aluminium, for the purpose of experimentally demonstrating a brightness increase. The Carambola is tested with different sources. (orig.)

  20. PET image reconstruction with system matrix based on point spread function derived from single photon incidence response

    CERN Document Server

    Xin, Fan; Ming-Kai, Yun; Xiao-Li, Sun; Xue-Xiang, Cao; Shuang-Quanm, Liu; Pei, Chai; Dao-Wu, Li; Long, Wei

    2014-01-01

    In positron emission tomography (PET) imaging, statistical iterative reconstruction (IR) techniques appear particularly promising since they can provide accurate physical model and geometric system description. The reconstructed image quality mainly depends on the system matrix model which describes the relationship between image space and projection space for the IR method. The system matrix can contain some physics factors of detection such as geometrical component and blurring component. Point spread function (PSF) is generally used to describe the blurring component. This paper proposes an IR method based on the PSF system matrix, which is derived from the single photon incidence response function. More specifically, the gamma photon incidence on a crystal array is simulated by the Monte Carlo (MC) simulation, and then the single photon incidence response functions are obtained. Subsequently, using the single photon incidence response functions, the coincidence blurring factor is acquired according to the...

  1. H-point standard addition method--first derivative spectrophotometry for simultaneous determination of palladium and cobalt.

    Science.gov (United States)

    Eskandari, Habibollah

    2006-02-01

    H-point standard addition method (HPSAM) has been applied for simultaneous determination of palladium and cobalt in trace levels, using disodium 1-nitroso-2-naphthol-3, 6-disulphonate (nitroso-R salt) as a selective chromogenic reagent. Palladium and cobalt in the neutral pHs form red color complexes with nitroso-R in aqueous solutions and making spectrophotometric monitoring possible. Simultaneous determination of palladium and cobalt were performed by HPSAM--first derivative spectrophotometry. First derivative signals at the two pairs of wavelengths, 523 and 589 nm or 513 and 554 nm were monitored with the addition of standard solutions of palladium or cobalt, respectively. The method is able to accurately determine palladium/cobalt ratio 1:10 to 15:1 (wt/wt). Accuracy and reproducibility of the determination method on the various amounts of palladium and cobalt known were evaluated in their binary mixtures. To investigate selectivity of the method and to ensure that no serious interferences were observed the effects of diverse ions on the determination of palladium and cobalt were also studied. The recommended procedure was successfully applied to real and synthetic cobalt or palladium alloys, B-complex ampoules, a palladium-charcoal mixture and real water matrices.

  2. Application of Enhanced Point Estimators to a Sample of In Vivo CT-derived Facial Soft Tissue Thicknesses.

    Science.gov (United States)

    Parks, Connie L; Kyllonen, Kelsey M; Monson, Keith L

    2017-07-01

    Facial approximations based on facial soft tissue depth measurement tables often utilize the arithmetic mean as a central tendency estimator. Stephan et al. (J Forensic Sci 2013;58:1439) suggest that the shorth and 75-shormax statistics are better suited to describe the central tendency of non-normal soft tissue depth data, while also accommodating normal distributions. The shorth, 75-shormax, arithmetic mean, and other central tendency estimators were evaluated using a CT-derived facial soft tissue depth dataset. Differences between arithmetic mean and shorth mean for the tissue depths examined ranged from 0 mm to +2.3 mm (average 0.6 mm). Differences between the arithmetic mean plus one standard deviation (to approximate the same data points covered by the 75-shormax) and 75-shormax values ranged from -0.8 mm to +0.7 mm (average 0.2 mm). The results of this research suggest that few practical differences exist across the central tendency point estimators for the evaluated soft tissue depth dataset. © 2017 American Academy of Forensic Sciences.

  3. Teradiode's high brightness semiconductor lasers

    Science.gov (United States)

    Huang, Robin K.; Chann, Bien; Burgess, James; Lochman, Bryan; Zhou, Wang; Cruz, Mike; Cook, Rob; Dugmore, Dan; Shattuck, Jeff; Tayebati, Parviz

    2016-03-01

    TeraDiode is manufacturing multi-kW-class ultra-high brightness fiber-coupled direct diode lasers for industrial applications. A fiber-coupled direct diode laser with a power level of 4,680 W from a 100 μm core diameter, world-record brightness levels for direct diode lasers. The fiber-coupled output corresponds to a Beam Parameter Product (BPP) of 3.5 mm-mrad and is the lowest BPP multi-kW-class direct diode laser yet reported. This laser is suitable for industrial materials processing applications, including sheet metal cutting and welding. This 4-kW fiber-coupled direct diode laser has comparable brightness to that of industrial fiber lasers and CO2 lasers, and is over 10x brighter than state-of-the-art direct diode lasers. We have also demonstrated novel high peak power lasers and high brightness Mid-Infrared Lasers.

  4. Visual features underlying perceived brightness as revealed by classification images.

    Directory of Open Access Journals (Sweden)

    Ilmari Kurki

    Full Text Available Along with physical luminance, the perceived brightness is known to depend on the spatial structure of the stimulus. Often it is assumed that neural computation of the brightness is based on the analysis of luminance borders of the stimulus. However, this has not been tested directly. We introduce a new variant of the psychophysical reverse-correlation or classification image method to estimate and localize the physical features of the stimuli which correlate with the perceived brightness, using a brightness-matching task. We derive classification images for the illusory Craik-O'Brien-Cornsweet stimulus and a "real" uniform step stimulus. For both stimuli, classification images reveal a positive peak at the stimulus border, along with a negative peak at the background, but are flat at the center of the stimulus, suggesting that brightness is determined solely by the border information. Features in the perceptually completed area in the Craik-O'Brien-Cornsweet do not contribute to its brightness, nor could we see low-frequency boosting, which has been offered as an explanation for the illusion. Tuning of the classification image profiles changes remarkably little with stimulus size. This supports the idea that only certain spatial scales are used for computing the brightness of a surface.

  5. Fracture risk among older men: osteopenia and osteoporosis defined using cut-points derived from female versus male reference data.

    Science.gov (United States)

    Pasco, J A; Lane, S E; Brennan, S L; Timney, E N; Bucki-Smith, G; Dobbins, A G; Nicholson, G C; Kotowicz, M A

    2014-03-01

    We explored the effect of using male and female reference data in a male sample to categorise areal bone mineral density (BMD). Using male reference data, a large proportion of fractures arose from osteopenia, whereas using female reference data shifted the fracture burden into normal BMD. The purpose of this study was to describe fracture risk associated with osteopenia and osteoporosis in older men, defined by areal BMD and using cut-points derived from male and female reference data. As part of the Geelong Osteoporosis Study, we followed 619 men aged 60-93 years after BMD assessments (performed 2001-2006) until 2010, fracture, death or emigration. Post-baseline fractures were radiologically confirmed, and proportions of fractures in each BMD category were age-standardised to national profiles. Based on World Health Organization criteria, and using male reference data, 207 men had normal BMD at the femoral neck, 357 were osteopenic and 55 were osteoporotic. Using female reference data, corresponding numbers were 361, 227 and 31. During the study, 130 men died, 15 emigrated and 63 sustained at least one fracture. Using male reference data, most (86.5 %) of the fractures occurred in men without osteoporosis on BMD criteria (18.4 % normal BMD, 68.1 % osteopenia). The pattern differed when female reference data were used; while most fractures arose from men without osteoporosis (88.2 %), the burden shifted from those with osteopenia (34.8 %) to those with normal BMD (53.4 %). Decreasing BMD categories defined increasing risk of fracture. Although men with osteoporotic BMD were at greatest risk, they made a relatively small contribution to the total burden of fractures. Using male reference data, two-thirds of the fractures arose from men with osteopenia. However, using female reference data, approximately half of the fractures arose from those with normal BMD. Using female reference data to define osteoporosis in men does not appear to be the optimal approach.

  6. Quantitative Brightness Analysis of Fluorescence Intensity Fluctuations in E. Coli.

    Directory of Open Access Journals (Sweden)

    Kwang-Ho Hur

    Full Text Available The brightness measured by fluorescence fluctuation spectroscopy specifies the average stoichiometry of a labeled protein in a sample. Here we extended brightness analysis, which has been mainly applied in eukaryotic cells, to prokaryotic cells with E. coli serving as a model system. The small size of the E. coli cell introduces unique challenges for applying brightness analysis that are addressed in this work. Photobleaching leads to a depletion of fluorophores and a reduction of the brightness of protein complexes. In addition, the E. coli cell and the point spread function of the instrument only partially overlap, which influences intensity fluctuations. To address these challenges we developed MSQ analysis, which is based on the mean Q-value of segmented photon count data, and combined it with the analysis of axial scans through the E. coli cell. The MSQ method recovers brightness, concentration, and diffusion time of soluble proteins in E. coli. We applied MSQ to measure the brightness of EGFP in E. coli and compared it to solution measurements. We further used MSQ analysis to determine the oligomeric state of nuclear transport factor 2 labeled with EGFP expressed in E. coli cells. The results obtained demonstrate the feasibility of quantifying the stoichiometry of proteins by brightness analysis in a prokaryotic cell.

  7. The DISCUSS Project: Revised Points to Consider for the Derivation of Induced Pluripotent Stem Cell Lines From Previously Collected Research Specimens

    Science.gov (United States)

    Hull, Sara Chandros; Isasi, Rosario

    2015-01-01

    Summary Human somatic cell reprogramming is a leading technology for accelerating disease modeling and drug discovery. The Deriving Induced Stem Cells Using Stored Specimens (DISCUSS) project is a consensus-building initiative designed to consider how human somatic cells obtained under general biomedical research protocols can be used in induced pluripotent stem cell (iPSC) derivation. We previously published a draft list of points to consider for the use of previously collected specimens in iPSC research and then initiated a structured feedback and comment process. Here, we present a summary of this feedback and revised list of points to consider. PMID:25561681

  8. Smoothly Varying Bright Blazars

    Science.gov (United States)

    Van Alfen, Nicholas; Hindman, Lauren; Moody, Joseph Ward; Biancardi, Rochelle; Whipple, Parkes; Gaunt, Caleb

    2018-01-01

    It is becoming increasingly apparent that blazar light can vary sinusoidally with periods of hundreds of days to tens of years. Such behavior is expected of, among other things, jets coming from binary black holes. To look for general variability in lesser-known blazars and AGN, in 2015-2016 we monitored 182 objects with Johnson V-band magnitudes reported as being < 16. In all, this campaign generated 22,000 frames from 2,000 unique pointings. We find that approximately one dozen of these objects show evidence of smooth variability consistent with sinusoidal periods. We report on the entire survey sample, highlighting those that show sinusoidal variations.

  9. Lightness, brightness, and brightness contrast: 2. Reflectance variation.

    Science.gov (United States)

    Arend, L E; Spehar, B

    1993-10-01

    Changes of annulus luminance in traditional disk-and-annulus patterns can be perceived to be either reflectance or illuminance changes. In the present experiments, we examined the effect of varying annulus reflectance. In Experiment 1, we placed test and standard patch-and-surround patterns in identical Mondrian patchworks. Only the luminance of the test surround changed from trial to trial, appearing as reflectance variation under constant illumination. Lightness matches were identical to brightness matches, as expected. In Experiment 2, we used only the patch and surround (no Mondrian). Instructions said that the illumination would change from trial to trial. Lightness and brightness-contrast data were identical; illumination gradients were indistinguishable from reflectance gradients. In Experiment 3, the patterns were the same, but the instructions said that the shade of gray of the test surround would change from trial to trial. Lightness matches were identical to brightness matches, again confirming the ambiguity of disk-and-annulus patterns.

  10. Best for the bright?

    DEFF Research Database (Denmark)

    Aarkrog, Vibe

    2012-01-01

    Apprenticeship is in many ways perceived as an optimal way of learning, as it is closely connected to a specific and concrete practice and involves the luxury of individual training. However studies of and literature about apprenticeship training all point to the necessity of further developing...... apprenticeship in order to enable the general and expansive learning that corresponds to the modern demands for qualifications (Fuller and Unwin, 1998; Gamble, 2002; Guile and Young, 1998; Shaw and McAndrew, 2008). That part of the training, which aims at transcending the specific community of practice, often...... be accomplished in other ways than through school-based learning. This issue is relevant because the new apprenticeship model partly substitutes school-based training with in-company-based training....

  11. Using Concept Maps to Assess the Effect of Graphing Calculators Use on Students' Concept Images of the Derivative at a Point

    Science.gov (United States)

    Serhan, Derar

    2009-01-01

    This study used concept maps to investigate the effect of using graphing calculators on students' understanding of the derivative at a point. The study looked for differences between the concept images that are held by students' who are using graphing calculators and the students who are not using them. Seventy one students enrolled in two…

  12. The Teratogenic Potencies of Valproic Acid Derivatives and Their Effects on Biological End-points are Related to Changes in Histone Deacetylase and Erk1/2 Activities

    DEFF Research Database (Denmark)

    Gotfryd, Kamil; Hansen, Maria; Kawa, Anna

    2011-01-01

    Valproic acid (VPA) is a known teratogen. In the present study, the effects of VPA and seven VPA derivatives with different teratogenic potencies (isobutyl-, 5-methyl-, ethyl-, propyl-, butyl-, pentyl- and hexyl-4-yn-VPA) were investigated in L929 cells in vitro. Evaluated end-points included...... associated with the teratogenic potencies of the VPA derivatives. However, in contrast to changes in Erk1/2 phosphorylation and H3 acetylation, significant changes in GSK-3ß phosphorylation could only be obtained in response to prolonged incubation at high drug concentration. There was an association between...... changes in H3 acetylation and GSK-3ß-Tyr216 phosphorylation, whereas none of these end-points were associated with changes in Erk1/2 phosphorylation. These results suggest that the teratogenic potencies of VPA and VPA derivatives are related to effects on both Erk1/2 and histone deacetylase activities...

  13. Bright Light Treatment in Psychiatry

    Directory of Open Access Journals (Sweden)

    Pinar Guzel Ozdemir

    2017-06-01

    Full Text Available Bright light treatment is a treatment modality that leads elevation of mood due to attenuation in depressive symptoms, regulation in circadian rhythm activity, increase the effect of antidepressants and amelioration in sleep quality. Bright light treatment is considered among the first-line treatments for seasonal affective disorder because of high response rates. Additionally, bright light treatment being extended to other conditions, including non-seasonal mood disorders, Alzheimer's disease, circadian rhythm sleep disorders, eating disorders, attention deficit hyperactivity disorder and other behavioral syndromes is likely to have a far reached use. Side effects are often temporary and can generally be overcome by reducing exposure time. The central focus on this paper is to review the action mechanisms, efficacy, usage areas, the ways of administration and side effects of the light treatment. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2017; 9(2.000: 177-188

  14. The Photometric Brightness Variation of Geostationary Orbit Satellite

    Directory of Open Access Journals (Sweden)

    Haingja Seo

    2013-09-01

    Full Text Available Photometric observation is one of the most effective techniques for determining the physical characteristics of unknown space objects and space debris. In this research, we examine the change in brightness of the Communication, Ocean, Meteorological Satellite-1 (COMS-1 Geostationary Orbit Satellite (GEO, and compare it to our estimate model. First, we calculate the maximum brightness time using our calculation method and then derive the light curve shape using our rendering model. The maximum brightness is then calculated using the induced equation from Pogson's formula. For a comparison with our estimation, we carried out photometric observation using an optical telescope. The variation in brightness and the shape of the light curve are similar to the calculations achieved using our model, but the maximum brightness shows a slightly different value from our calculation result depending on the input parameters. This paper examines the photometric phenomenon of the variation in brightness of a GEO satellite, and the implementation of our approach to understanding the characteristics of space objects.

  15. Network based sky Brightness Monitor

    Science.gov (United States)

    McKenna, Dan; Pulvermacher, R.; Davis, D. R.

    2009-01-01

    We have developed and are currently testing an autonomous 2 channel photometer designed to measure the night sky brightness in the visual wavelengths over a multi-year campaign. The photometer uses a robust silicon sensor filtered with Hoya CM500 glass. The Sky brightness is measured every minute at two elevation angles typically zenith and 20 degrees to monitor brightness and transparency. The Sky Brightness monitor consists of two units, the remote photometer and a network interface. Currently these devices use 2.4 Ghz transceivers with a free space range of 100 meters. The remote unit is battery powered with day time recharging using a solar panel. Data received by the network interface transmits data via standard POP Email protocol. A second version is under development for radio sensitive areas using an optical fiber for data transmission. We will present the current comparison with the National Park Service sky monitoring camera. We will also discuss the calibration methods used for standardization and temperature compensation. This system is expected to be deployed in the next year and be operated by the International Dark Sky Association SKYMONITOR project.

  16. Stability of bright solitons in some physical systems

    Energy Technology Data Exchange (ETDEWEB)

    Pelap, Francois B [Department of Physics, Faculty of Science, University of Dschang, P O Box 69, Dschang (Cameroon); Talla, Pierre K [Department of Physics, Faculty of Science, University of Dschang, P O Box 69, Dschang (Cameroon); Tchitnga, Robert [Department of Physics, Faculty of Science, University of Dschang, P O Box 69, Dschang (Cameroon); Faye, Mansour M [Departement de Physique, Faculte des Sciences et Techniques, Universite Cheikh Anta DIOP de Dakar, BP 5005, Dakar - Fann (Senegal)

    2007-02-15

    Dynamical systems described by the modified quintic complex Ginzburg Landau equation and its derivative forms are considered and the stability of their bright soliton solution is investigated numerically by means of the split-step Fourier method. Some discussions related to the way of ensuring the stability of this solution are presented.

  17. Colloidal Properties of Aqueous Fullerenes: Isoelectric Points and Aggregation Kinetics of C60 and C60 Derivatives

    Science.gov (United States)

    Aqueous colloidal suspensions of C-60 (aqu/C-60) and the C-60 derivatives PCBM ([6,6]-phenyl C-61-butyric acid methyl ester) and the corresponding butyl and octyl esters, PCBB and PCBO (aqu/PCB-R, where R is an alkyl group), were produced by stirring in double deionized water for...

  18. Multiple positive solutions for singular m-point boundary-value problems with nonlinearities depending on the derivative

    Directory of Open Access Journals (Sweden)

    Baoqiang Yan

    2008-10-01

    Full Text Available Using the fixed point theorem in cones, this paper shows the existence of multiple positive solutions for the singular $m$-point boundary-value problem $$displaylines{ x''(t+a(tf(t,x(t,x'(t=0,quad 0

  19. A solution thermodynamics definition of the fiber saturation point and the derivation of a wood-water phase (state) diagram

    Science.gov (United States)

    Samuel L. Zelinka; Samuel V. Glass; Joseph E. Jakes; Donald S. Stone

    2016-01-01

    The fiber saturation point (FSP) is an important concept in wood– moisture relations that differentiates between the states of water in wood and has been discussed in the literature for over 100 years. Despite its importance and extensive study, the exact theoretical definition of the FSP and the operational definition (the correct way to measure the FSP) are still...

  20. Derivation of Threshold Values for Groundwater in Romania, in order to distinguish Point & Diffuse pollution from natural background levels

    NARCIS (Netherlands)

    Schipper, P.N.M.; Radu, E.; Vliegenthart, F.; Balaet, R.

    2010-01-01

    Romania aims to adopt and implement the European Union's legislation, also including that for the field of water management. Like other countries, groundwater in Romania is locally polluted from point sources, such as leaking landfills, as well as from diffuse pollution sources, include fertilizers,

  1. Iapetus Bright and Dark Terrains

    Science.gov (United States)

    1990-01-01

    Saturn's outermost large moon, Iapetus, has a bright, heavily cratered icy terrain and a dark terrain, as shown in this Voyager 2 image taken on August 22, 1981. Amazingly, the dark material covers precisely the side of Iapetus that leads in the direction of orbital motion around Saturn (except for the poles), whereas the bright material occurs on the trailing hemisphere and at the poles. The bright terrain is made of dirty ice, and the dark terrain is surfaced by carbonaceous molecules, according to measurements made with Earth-based telescopes. Iapetus' dark hemisphere has been likened to tar or asphalt and is so dark that no details within this terrain were visible to Voyager 2. The bright icy hemisphere, likened to dirty snow, shows many large impact craters. The closest approach by Voyager 2 to Iapetus was a relatively distant 600,000 miles, so that our best images, such as this, have a resolution of about 12 miles. The dark material is made of organic substances, probably including poisonous cyano compounds such as frozen hydrogen cyanide polymers. Though we know a little about the dark terrain's chemical nature, we do not understand its origin. Two theories have been developed, but neither is fully satisfactory--(1) the dark material may be organic dust knocked off the small neighboring satellite Phoebe and 'painted' onto the leading side of Iapetus as the dust spirals toward Saturn and Iapetus hurtles through the tenuous dust cloud, or (2) the dark material may be made of icy-cold carbonaceous 'cryovolcanic' lavas that were erupted from Iapetus' interior and then blackened by solar radiation, charged particles, and cosmic rays. A determination of the actual cause, as well as discovery of any other geologic features smaller than 12 miles across, awaits the Cassini Saturn orbiter to arrive in 2004.

  2. New clinical classification of dental arch form using facial axis points derived from three-dimensional models.

    Science.gov (United States)

    Bayome, Mohamed; Han, Seong Ho; Choi, Jong-Hyuk; Kim, Seong-Hun; Baek, Seung-Hak; Kim, Dong-Jae; Kook, Yoon-Ah

    2011-11-01

    The purpose of the present study was to use facial axis (FA) points to classify dental arch form generated from an analysis of 3-D virtual models of a sample of normal occlusions. A secondary aim was to introduce a new arch form template based on this classification for clinical application. One hundred and twenty five plaster models of Class I occlusions were 3-D scanned (Orapix Co., Ltd, Seoul, Korea) and FA points digitized on the virtual models using Rapidform 2006 software (INUS Technology Inc., Seoul, Korea). Following intercanine and intermolar arch width and depth measurements, K-means cluster analysis was applied on 77 cases (Dataset 1) to classify the sample into arch form types. A curve of best fit of the mean arch form of each type was generated. The remaining 48 cases (Dataset 2) were mapped into the clusters and a multivariate test was performed to assess the differences among the clusters. Classification into five clusters demonstrated maximum inter-cluster distance in the arch parameters and produced the most homogeneous cluster size. The differences between the 5 cluster types were statistically but not clinically significant and so they were recombined to form three clusters representing 'narrow', 'moderate' and 'wide' arch forms. A template with three arch form types based on anterior and posterior dimensions has been proposed through 3-D analysis of FA points for more accurate arch form identification and arch wire selection.

  3. LSST Site: Sky Brightness Data

    Science.gov (United States)

    Burke, Jamison; Claver, Charles

    2015-01-01

    The Large Synoptic Survey Telescope (LSST) is an upcoming robotic survey telescope. At the telescope site on Cerro Pachon in Chile there are currently three photodiodes and a Canon camera with a fisheye lens, and both the photodiodes and Canon monitor the night sky continuously. The NIST-calibrated photodiodes directly measure the flux from the sky, and the sky brightness can also be obtained from the Canon images via digital aperture photometry. Organizing and combining the two data sets gives nightly information of the development of sky brightness across a swath of the electromagnetic spectrum, from blue to near infrared light, and this is useful for accurately predicting the performance of the LSST. It also provides data for models of moonlight and twilight sky brightness. Code to accomplish this organization and combination was successfully written in Python, but due to the backlog of data not all of the nights were processed by the end of the summer.Burke was supported by the NOAO/KPNO Research Experiences for Undergraduates (REU) Program which is funded by the National Science Foundation Research Experiences for Undergraduates Program (AST-1262829).

  4. Laser-induced ultrasonic waveform derivation and transition from a point to a homogeneous illumination of a plate.

    Science.gov (United States)

    Laloš, Jernej; Jezeršek, Matija; Petkovšek, Rok; Požar, Tomaž

    2017-11-01

    Ultrasound modeling, being an established practice, is used to study the fundamentals of light-matter interactions. Although much has been published on the matter, pressure and thermal expansion induction mechanisms in laser ultrasonics have rarely been combined, as they should, in a single ultrasonic source while the effects of its size variation have only been shown to a limited extent. In the paper, we unite these light-matter interaction mechanisms, with inclusion of lateral optical forces, into a single laser-stimulated source as it is observed in nature. With a laser pulse as a manipulable source, we simulate the multifaceted workings of light-matter interactions by exposing the distinct transients originating from different source localities as generated by different induction mechanisms. We also present a transition of simulated ultrasonic waveforms in the epicentral point on the surface of a solid plate opposite from the source while it is expanded from a point to a quasi-limitless extent for pressure and thermal expansion generation regimes. The model utilizes geometric probability theory together with Huygens' superposition principle and temporal convolutions to construct the desired waveforms out of individual Green's functions. We show how the ultrasound generation regimes stem out of a single source and how its size together with energy and momentum transfers during the light-matter interactions affect the induced ultrasonic transients. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. PROFFIT: Analysis of X-ray surface-brightness profiles

    Science.gov (United States)

    Eckert, Dominique

    2016-08-01

    PROFFIT analyzes X-ray surface-brightness profiles for data from any X-ray instrument. It can extract surface-brightness profiles in circular or elliptical annuli, using constant or logarithmic bin size, from the image centroid, the surface-brightness peak, or any user-given center, and provides surface-brightness profiles in any circular or elliptical sectors. It offers background map support to extract background profiles, can excise areas using SAO DS9-compatible (ascl:0003.002) region files to exclude point sources, provides fitting with a number of built-in models, including the popular beta model, double beta, cusp beta, power law, and projected broken power law, uses chi-squared or C statistic, and can fit on the surface-brightness or counts data. It has a command-line interface similar to HEASOFT’s XSPEC (ascl:9910.005) package, provides interactive help with a description of all the commands, and results can be saved in FITS, ROOT or TXT format.

  6. Tolerance of image enhancement brightness and contrast in lateral cephalometric digital radiography for Steiner analysis

    Science.gov (United States)

    Rianti, R. A.; Priaminiarti, M.; Syahraini, S. I.

    2017-08-01

    Image enhancement brightness and contrast can be adjusted on lateral cephalometric digital radiographs to improve image quality and anatomic landmarks for measurement by Steiner analysis. To determine the limit value for adjustments of image enhancement brightness and contrast in lateral cephalometric digital radiography for Steiner analysis. Image enhancement brightness and contrast were adjusted on 100 lateral cephalometric radiography in 10-point increments (-30, -20, -10, 0, +10, +20, +30). Steiner analysis measurements were then performed by two observers. Reliabilities were tested by the Interclass Correlation Coefficient (ICC) and significance tested by ANOVA or the Kruskal Wallis test. No significant differences were detected in lateral cephalometric analysis measurements following adjustment of the image enhancement brightness and contrast. The limit value of adjustments of the image enhancement brightness and contrast associated with incremental 10-point changes (-30, -20, -10, 0, +10, +20, +30) does not affect the results of Steiner analysis.

  7. Combination of First Derivative Spectrophotometry and H-Point Standard Addition Method for Simultaneous Determination of Guaifenesin and Theophylline in Cough Syrup

    Directory of Open Access Journals (Sweden)

    R. Hajian

    2011-01-01

    Full Text Available Combination of first derivative spectrophotometric and H-point standard addition method (HPSAM has been applied for simultaneous determination of guaifenesin and theophylline. First derivative signals at the two pairs of wavelengths, 282.0-290.2 nm and 277.4-287.8 nm were monitored with the addition of standard solutions of both guaifenesin and theophylline in the ratio of 1:1. The method is able to accurately determine guaifenesin and theophylline (1:5 to 10:1 mole ratios. Accuracy and reproducibility of the determination method on the various amounts of guaifenesin and theophylline with known concentrations were evaluated in their binary mixtures. The recommended procedure was successfully applied to some cough syrups and synthetic mixtures with satisfactory results.

  8. Search for bright nearby M dwarfs with virtual observatory tools

    Energy Technology Data Exchange (ETDEWEB)

    Aberasturi, M.; Caballero, J. A.; Montesinos, B.; Gálvez-Ortiz, M. C.; Solano, E.; Martín, E. L. [Centro de Astrobiología (CSIC-INTA), Departamento de Astrofísica, P.O. Box 78, E-28691 Villanueva de la Cañada, Madrid (Spain)

    2014-08-01

    Using Virtual Observatory tools, we cross-matched the Carlsberg Meridian 14 and the 2MASS Point Source catalogs to select candidate nearby bright M dwarfs distributed over ∼25,000 deg{sup 2}. Here, we present reconnaissance low-resolution optical spectra for 27 candidates that were observed with the Intermediate Dispersion Spectrograph at the 2.5 m Isaac Newton Telescope (R≈ 1600). We derived spectral types from a new spectral index, R, which measures the ratio of fluxes at 7485-7015 Å and 7120-7150 Å. We also used VOSA, a Virtual Observatory tool for spectral energy distribution fitting, to derive effective temperatures and surface gravities for each candidate. The resulting 27 targets were M dwarfs brighter than J = 10.5 mag, 16 of which were completely new in the Northern hemisphere and 7 of which were located at less than 15 pc. For all of them, we also measured Hα and Na I pseudo-equivalent widths, determined photometric distances, and identified the most active stars. The targets with the weakest sodium absorption, namely, J0422+2439 (with X-ray and strong Hα emissions), J0435+2523, and J0439+2333, are new members in the young Taurus-Auriga star-forming region based on proper motion, spatial distribution, and location in the color-magnitude diagram, which reopens the discussion on the deficit of M2-4 Taurus stars. Finally, based on proper motion diagrams, we report on a new wide M dwarf binary system in the field, LSPM J0326+3929EW.

  9. How Bright Can Supernovae Get?

    Science.gov (United States)

    Kohler, Susanna

    2016-04-01

    Supernovae enormous explosions associated with the end of a stars life come in a variety of types with different origins. A new study has examined how the brightest supernovae in the Universe are produced, and what limits might be set on their brightness.Ultra-Luminous ObservationsRecent observations have revealed many ultra-luminous supernovae, which haveenergies that challenge our abilities to explain them usingcurrent supernova models. An especially extreme example is the 2015 discovery of the supernova ASASSN-15lh, which shone with a peak luminosity of ~2*1045 erg/s, nearly a trillion times brighter than the Sun. ASASSN-15lh radiated a whopping ~2*1052 erg in the first four months after its detection.How could a supernova that bright be produced? To explore the answer to that question, Tuguldur Sukhbold and Stan Woosley at University of California, Santa Cruz, have examined the different sources that could produce supernovae and calculated upper limits on the potential luminosities ofeach of these supernova varieties.Explosive ModelsSukhbold and Woosley explore multiple different models for core-collapse supernova explosions, including:Prompt explosionA stars core collapses and immediately explodes.Pair instabilityElectron/positron pair production at a massive stars center leads to core collapse. For high masses, radioactivity can contribute to delayed energy output.Colliding shellsPreviously expelled shells of material around a star collide after the initial explosion, providing additional energy release.MagnetarThe collapsing star forms a magnetar a rapidly rotating neutron star with an incredibly strong magnetic field at its core, which then dumps energy into the supernova ejecta, further brightening the explosion.They then apply these models to different types of stars.Setting the LimitThe authors show that the light curve of ASASSN-15lh (plotted in orange) can be described by a model (black curve) in which a magnetar with an initial spin period of 0.7 ms

  10. Development and validation of a novel method to derive central aortic systolic pressure from the radial pressure waveform using an n-point moving average method.

    Science.gov (United States)

    Williams, Bryan; Lacy, Peter S; Yan, Peter; Hwee, Chua-Ngak; Liang, Chen; Ting, Choon-Meng

    2011-02-22

    The purpose of this study was to develop and validate the novel application of a simple n-point moving average (NPMA)--a mathematical low pass filter--to noninvasively derive central aortic systolic pressure (CASP) from the radial artery pressure waveform (RAPWF) in humans. CASP may be an important independent determinant of clinical outcomes. Development of simple, well-validated methods to noninvasively derive CASP is necessary to facilitate the routine clinical measurement of CASP. Three studies in different population cohorts were used to develop and validate the NPMA method to derive CASP in humans: 1) a development study (n = 217), describing the optimal application of the NPMA to derive CASP; 2) a validation study comparing NPMA-CASP with CASP derived using a generalized transfer function (GTF-CASP [SphygmoCor system, AtCor, Sydney, Australia]) using 5,349 RAPWFs from the CAFE (Conduit Artery Function Evaluation) study; and 3) an invasive validation study (n = 20) comparing NPMA-CASP with direct aortic root pressure measurements during cardiac catheterization. In the development study, when using the NPMA, a denominator of n/4 (where n = tonometer sampling frequency) most accurately defined CASP relative to GTF-CASP. Validation of NPMA-CASP using RAPWFs from the CAFE study revealed excellent correlation and agreement (r(2) = 0.993, mean difference 0.3 ± 1.0 mm Hg). The agreement remained robust after stratification by sex, age, treatment, and diabetes status. There was also excellent correlation and agreement (r(2) = 0.98, p < 0.001) between directly measured aortic root systolic pressures (Millar's catheter) at cardiac catheterization versus NPMA-CASP, derived simultaneously from noninvasive RAPWFs. We show that an NPMA with a denominator of one-quarter of the tonometer sampling frequency accurately defines CASP when applied to noninvasively acquired RAPWFs in man. These novel findings have important implications for the simplification of noninvasive CASP

  11. The Atacama Cosmology Telescope: Beam Measurements and the Microwave Brightness Temperatures of Uranus and Saturn

    Science.gov (United States)

    Hasselfield, Matthew; Moodley, Kavilan; Bond, J. Richard; Das, Sudeep; Devlin, Mark J.; Dunkley, Joanna; Dunner, Rolando; Fowler, Joseph W.; Gallardo, Patricio; Gralla, Megan B.; hide

    2013-01-01

    We describe the measurement of the beam profiles and window functions for the Atacama Cosmology Telescope (ACT), which operated from 2007 to 2010 with kilopixel bolometer arrays centered at 148, 218, and 277 GHz. Maps of Saturn are used to measure the beam shape in each array and for each season of observations. Radial profiles are transformed to Fourier space in a way that preserves the spatial correlations in the beam uncertainty to derive window functions relevant for angular power spectrum analysis. Several corrections are applied to the resulting beam transforms, including an empirical correction measured from the final cosmic microwave background (CMB) survey maps to account for the effects of mild pointing variation and alignment errors. Observations of Uranus made regularly throughout each observing season are used to measure the effects of atmospheric opacity and to monitor deviations in telescope focus over the season. Using the WMAP-based calibration of the ACT maps to the CMB blackbody, we obtain precise measurements of the brightness temperatures of the Uranus and Saturn disks at effective frequencies of 149 and 219 GHz. For Uranus we obtain thermodynamic brightness temperatures T(149/U) = 106.7 +/- 2.2 K and T(219/U) = 100.1 +/- 3.1 K. For Saturn, we model the effects of the ring opacity and emission using a simple model and obtain resulting (unobscured) disk temperatures of T(149/S) = 137.3 +/- 3.2 K and T(219/S) = 137.3 +/- 4.7 K.

  12. Combining structure-from-motion derived point clouds from satellites and unmanned aircraft systems images with ground-truth data to create high-resolution digital elevation models

    Science.gov (United States)

    Palaseanu, M.; Thatcher, C.; Danielson, J.; Gesch, D. B.; Poppenga, S.; Kottermair, M.; Jalandoni, A.; Carlson, E.

    2016-12-01

    Coastal topographic and bathymetric (topobathymetric) data with high spatial resolution (1-meter or better) and high vertical accuracy are needed to assess the vulnerability of Pacific Islands to climate change impacts, including sea level rise. According to the Intergovernmental Panel on Climate Change reports, low-lying atolls in the Pacific Ocean are extremely vulnerable to king tide events, storm surge, tsunamis, and sea-level rise. The lack of coastal topobathymetric data has been identified as a critical data gap for climate vulnerability and adaptation efforts in the Republic of the Marshall Islands (RMI). For Majuro Atoll, home to the largest city of RMI, the only elevation dataset currently available is the Shuttle Radar Topography Mission data which has a 30-meter spatial resolution and 16-meter vertical accuracy (expressed as linear error at 90%). To generate high-resolution digital elevation models (DEMs) in the RMI, elevation information and photographic imagery have been collected from field surveys using GNSS/total station and unmanned aerial vehicles for Structure-from-Motion (SfM) point cloud generation. Digital Globe WorldView II imagery was processed to create SfM point clouds to fill in gaps in the point cloud derived from the higher resolution UAS photos. The combined point cloud data is filtered and classified to bare-earth and georeferenced using the GNSS data acquired on roads and along survey transects perpendicular to the coast. A total station was used to collect elevation data under tree canopies where heavy vegetation cover blocked the view of GNSS satellites. A subset of the GPS / total station data was set aside for error assessment of the resulting DEM.

  13. Synthetic Bioluminescent Coelenterazine Derivatives.

    Science.gov (United States)

    Nishihara, Ryo; Citterio, Daniel; Suzuki, Koji

    2016-01-01

    The development of coelenterazine (CTZ) derivatives resulting in superior optical characteristics is an efficient method to extend the range of its possible applications. Here, we describe the synthesis of three C-6 substituted CTZ derivatives retaining the recognition by Renilla luciferase (RLuc) and its derivatives. The novel derivatives are useful as bright blue-shifted CTZ derivatives, which can be used as an alternative to hitherto reported compound DeepBlueC™.

  14. New Distant Comet Headed for Bright Encounter

    Science.gov (United States)

    1995-08-01

    of a dense dust cloud around the nucleus. It is in fact likely that most of the light observed from the central condensation in the comet's head is sunlight reflected from the particles in this cloud. The nucleus is probably completely hidden from view inside this cloud and we do not see it at all. When we cannot observe the nucleus of a comet directly, we can only judge its size indirectly from the amount of dust it produces; a larger dust production will normally correspond to a larger nucleus. However, a temporarily high dust production rate during an outburst from the nucleus will lead to an overestimate of its size. In this case, the comet's brightness will begin to fade after a while, as the dust particles ejected during the outburst slowly disperse into space. A main goal of future observations is therefore to decide whether or not Comet Hale-Bopp has just undergone an outburst. For this, the brightness of the central condensation and the size and shape of the dust cloud must be carefully monitored as long as possible. In this connection, the relatively bright pre-discovery images from April 1993 and May 1995 (see above) seem to argue against a recent outburst. How bright will the comet be at perihelion ? The main question now asked from many sides is obviously how bright the comet will be when it passes perihelion in 1997. Will it, as some headlines have already stated, and in view of its current brightness, become the `comet of the century, if not of the millennium' ? From the above, it is clear that no firm prediction can be made before we have learned whether the present brightness is `stable' or whether it undergoes important variations which indicate that there has been a recent outburst. Astronomers are therefore very reluctant to express themselves on this point until further observations become available. However, if the comet did not undergo a recent outburst and the nucleus is indeed as large as the current brightness would appear to indicate, then

  15. Brightness and darkness as perceptual dimensions

    NARCIS (Netherlands)

    Vladusich, T.; Lucassen, M.P.; Cornelissen, F.W.

    2007-01-01

    A common-sense assumption concerning visual perception states that brightness and darkness cannot coexist at a given spatial location. One corollary of this assumption is that achromatic colors, or perceived grey shades, are contained in a one-dimensional (1-D) space varying from bright to dark. The

  16. SURFACE PHOTOMETRY OF LOW SURFACE BRIGHTNESS GALAXIES

    NARCIS (Netherlands)

    DEBLOK, WJG; VANDERHULST, JM; BOTHUN, GD

    1995-01-01

    Low surface brightness (LSB) galaxies are galaxies dominated by an exponential disc whose central surface brightness is much fainter than the value of mu(B)(0) = 21.65 +/- 0.30 mag arcsec(-2) found by Freeman. In this paper we present broadband photometry of a sample of 21 late-type LSB galaxies.

  17. Brightness Alteration with Interweaving Contours

    Directory of Open Access Journals (Sweden)

    Sergio Roncato

    2012-12-01

    Full Text Available Chromatic induction is observed whenever the perceived colour of a target surface shifts towards the hue of a neighbouring surface. Some vivid manifestations may be seen in a white background where thin coloured lines have been drawn (assimilation or when lines of different colours are collinear (neon effect or adjacent (watercolour to each other. This study examines a particular colour induction that manifests in concomitance with an opposite effect of colour saturation (or anti-spread. The two phenomena can be observed when a repetitive pattern is drawn in which outline thin contours intercept wider contours or surfaces, colour spreading appear to fill the surface occupied by surfaces or thick lines whereas the background traversed by thin lines is seen as brighter or filled of a saturated white. These phenomena were first observed by Bozzi (1975 and Kanizsa (1979 in figural conditions that did not allow them to document their conjunction. Here we illustrate various manifestations of this twofold phenomenon and compare its effects with the known effects of brightness and colour induction. Some conjectures on the nature of these effects are discussed.

  18. Bright Sparks of Our Future!

    Science.gov (United States)

    Riordan, Naoimh

    2016-04-01

    My name is Naoimh Riordan and I am the Vice Principal of Rockboro Primary School in Cork City, South of Ireland. I am a full time class primary teacher and I teach 4th class, my students are aged between 9-10 years. My passion for education has developed over the years and grown towards STEM (Science, Technology, Engineering and Mathematics) subjects. I believe these subjects are the way forward for our future. My passion and beliefs are driven by the unique after school programme that I have developed. It is titled "Sparks" coming from the term Bright Sparks. "Sparks" is an after school programme with a difference where the STEM subjects are concentrated on through lessons such as Science, Veterinary Science Computer Animation /Coding, Eco engineering, Robotics, Magical Maths, Chess and Creative Writing. All these subjects are taught through activity based learning and are one-hour long each week for a ten-week term. "Sparks" is fully inclusive and non-selective which gives all students of any level of ability an opportunity to engage into these subjects. "Sparks" is open to all primary students in County Cork. The "Sparks" after school programme is taught by tutors from the different Universities and Colleges in Cork City. It works very well because the tutor brings their knowledge, skills and specialised equipment from their respective universities and in turn the tutor gains invaluable teaching practise, can trial a pilot programme in a chosen STEM subject and gain an insight into what works in the physical classroom.

  19. Space Brightness Evaluation for a Daylit Room

    Directory of Open Access Journals (Sweden)

    Takashi Maruyama

    2011-05-01

    Full Text Available One of the most important problems for lighting design is how to reduce an electric energy. One way to solve this problem is use of daylight, but little is known how to perceive a brightness of a room illuminated by daylight come in through a window and artificial light. Although the horizontal illuminance increases because of daylight, we would not perceive the room as bright as brightness estimated by the illuminance. The purpose of this study is to measure the space brightness for daylit room and to propose a evaluation method. The experiment was conducted with a couple of miniature office rooms, standard room and test room. Test room has several types of windows and standard room has no window. Subject was asked to evaluate the brightness of the test room relative to the standard room with method of magnitude estimation. It was found that brightness of daylit room did not increase simply with horizontal illuminance. Subject perceived a daylit room darker than a room illuminated only by the artificial light even if horizontal illuminance of these room was same. The effect of daylight on space brightness would vary with the window size and intensity of daylight or artificial light.

  20. Bright boys the making of information technology

    CERN Document Server

    Green, Tom

    2010-01-01

    Everything has a beginning. None was more profound-and quite as unexpected-than Information Technology. Here for the first time is the untold story of how our new age came to be and the bright boys who made it happen. What began on the bare floor of an old laundry building eventually grew to rival in size the Manhattan Project. The unexpected consequence of that journey was huge---what we now know as Information Technology. For sixty years the bright boys have been totally anonymous while their achievements have become a way of life for all of us. "Bright Boys" brings them home. By 1950 they'd

  1. Using an Unmanned Aerial Vehicle-Based Digital Imaging System to Derive a 3D Point Cloud for Landslide Scarp Recognition

    Directory of Open Access Journals (Sweden)

    Abdulla Al-Rawabdeh

    2016-01-01

    Full Text Available Landslides often cause economic losses, property damage, and loss of lives. Monitoring landslides using high spatial and temporal resolution imagery and the ability to quickly identify landslide regions are the basis for emergency disaster management. This study presents a comprehensive system that uses unmanned aerial vehicles (UAVs and Semi-Global dense Matching (SGM techniques to identify and extract landslide scarp data. The selected study area is located along a major highway in a mountainous region in Jordan, and contains creeping landslides induced by heavy rainfall. Field observations across the slope body and a deformation analysis along the highway and existing gabions indicate that the slope is active and that scarp features across the slope will continue to open and develop new tension crack features, leading to the downward movement of rocks. The identification of landslide scarps in this study was performed via a dense 3D point cloud of topographic information generated from high-resolution images captured using a low-cost UAV and a target-based camera calibration procedure for a low-cost large-field-of-view camera. An automated approach was used to accurately detect and extract the landslide head scarps based on geomorphological factors: the ratio of normalized Eigenvalues (i.e., λ1/λ2 ≥ λ3 derived using principal component analysis, topographic surface roughness index values, and local-neighborhood slope measurements from the 3D image-based point cloud. Validation of the results was performed using root mean square error analysis and a confusion (error matrix between manually digitized landslide scarps and the automated approaches. The experimental results using the fully automated 3D point-based analysis algorithms show that these approaches can effectively distinguish landslide scarps. The proposed algorithms can accurately identify and extract landslide scarps with centimeter-scale accuracy. In addition, the combination

  2. A spectroscopic atlas of bright stars

    CERN Document Server

    Martin, Jack

    2009-01-01

    Suitable for amateur astronomers interested in practical spectroscopy or spectrography, this reference book identifies more than 70 (northern hemisphere) bright stars that are suitable observational targets. It provides finder charts for locating these sometimes-familiar stars.

  3. Nimbus-5 ESMR Polar Gridded Brightness Temperatures

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nimbus-5 Electrically Scanning Microwave Radiometer (ESMR) data set consists of gridded brightness temperature arrays for the Arctic and Antarctic, spanning 11...

  4. Snow Melt Onset Over Arctic Sea Ice from SMMR and SSM/I-SSMIS Brightness Temperatures, Version 3

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes yearly snow melt onset dates over Arctic sea ice derived from brightness temperatures from the Scanning Multichannel Microwave Radiometer...

  5. Detection of Cancerous Masses in Mammograms by Template Matching: Optimization of Template Brightness Distribution by Means of Evolutionary Algorithm

    National Research Council Canada - National Science Library

    Bator, Marcin; Nieniewski, Mariusz

    2012-01-01

    .... This optimization is performed by the evolutionary algorithm using an auxiliary mass classifier. Brightness along the radius of the circularly symmetric template is coded indirectly by its second derivative...

  6. Effect of Interior Chromaticness on Space Brightness

    Directory of Open Access Journals (Sweden)

    Hidenari Takada

    2011-05-01

    Full Text Available To design a lighting environment, horizontal illuminance is generally used as the brightness of a room. But it is reported that a subjective brightness does not always match the horizontal illuminance. For example, the room furnished with high saturated colored objects is perceived brighter than the room furnished with achromatic objects, even though the horizontal illuminance is the same. To investigate a effect of interior chromaticness on space brightness, we conducted the experiment in four miniature rooms that were different in terms of chromaticness of interior decorating surfaces, but kept lightness of surfaces constant. Subjects were asked to set the illuminance of reference room, that is furnished with achromatic objects, to equate the brightness of the test room, that is with chromatic objects. Four of seven subjects needed less illuminance to get the equality of space brightness if the test room had a saturated objects. The illuminance ratio of test to reference room was about 1.4. Other three subjects set the illuminance of reference room almost equal to test room. Thus, there are differences between individuals so further work would be needed to estimate the quantitative effect of interior chromaticness on space brightness.

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

    Science.gov (United States)

    Radhakrishnan, R; Manikandan, N; Aravinthan, K

    2015-12-01

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

  8. Human Adolescent Phase Response Curves to Bright White Light.

    Science.gov (United States)

    Crowley, Stephanie J; Eastman, Charmane I

    2017-08-01

    Older adolescents are particularly vulnerable to circadian misalignment and sleep restriction, primarily due to early school start times. Light can shift the circadian system and could help attenuate circadian misalignment; however, a phase response curve (PRC) to determine the optimal time for receiving light and avoiding light is not available for adolescents. We constructed light PRCs for late pubertal to postpubertal adolescents aged 14 to 17 years. Participants completed 2 counterbalanced 5-day laboratory sessions after 8 or 9 days of scheduled sleep at home. Each session included phase assessments to measure the dim light melatonin onset (DLMO) before and after 3 days of free-running through an ultradian light-dark (wake-sleep) cycle (2 h dim [~20 lux] light, 2 h dark). In one session, intermittent bright white light (~5000 lux; four 20-min exposures) was alternated with 10 min of dim room light once per day for 3 consecutive days. The time of light varied among participants to cover the 24-h day. For each individual, the phase shift to bright light was corrected for the free-run derived from the other laboratory session with no bright light. One PRC showed phase shifts in response to light start time relative to the DLMO and another relative to home sleep. Phase delay shifts occurred around the hours corresponding to home bedtime. Phase advances occurred during the hours surrounding wake time and later in the afternoon. The transition from delays to advances occurred at the midpoint of home sleep. The adolescent PRCs presented here provide a valuable tool to time bright light in adolescents.

  9. Passive acoustic derived bubble flux and applications to natural gas seepage in the Mackenzie Delta, NWT, Canada and Coal Oil Point, CA

    Science.gov (United States)

    Culling, D.; Leifer, I.; Dallimore, S.; Alcala, K.

    2012-12-01

    Minnaert equation predicts. Furthermore, bubbles from a cohesive media escaped in pulses of multiple bubbles, which caused significant inter-bubble acoustic coupling and mud-bubble interaction. The acoustic signature of subsurface bubble migration and concurrent sediment movements, including bubble pinch off, presented additional complexities. Use of passive acoustic derived flux was applied to natural gas seepage in the Mackenzie Delta in the North West Territories, Canada as well as offshore Coal Oil Point (COP), CA. Video data were used to calibrate the COP acoustic observations and showed a strong current impact for non-cohesive sediments. Seepage flux in the delta (cohesive sediments) was calibrated using a custom turbine tent that directly measured flux. Further applications of passive acoustic-derived seep fluxes include monitoring of marine pipelines for leaks, and studying biogenic wetlands ebullition as well as thermogenic and hydrate seepage.

  10. Subwavelength electromagnetic near-field imaging of point dipole with metamaterial nanoslab.

    Science.gov (United States)

    Hakkarainen, Timo; Setälä, Tero; Friberg, Ari T

    2009-10-01

    We investigate near-field imaging of a point dipole by a lossy, nanoscale metamaterial slab. Making use of the electromagnetic angular-spectrum representation, we derive the Green tensor for the field transmission through the metamaterial slab, duly considering multiple reflections, polarizations, and wave-vector signs. With this general formalism, we calculate the point-spread function of the imaging system, which enables us to assess, for instance, resolution and image brightness. Our results demonstrate that with the metamaterial-slab lens one achieves resolution beyond the conventional diffraction limit of half the wavelength. In general, the resolution and image brightness are degraded when the slab thickness and absorption increase, but we show that in some cases the resolution is rather insensitive to the magnitude of the losses in the metamaterial.

  11. A selective deficit in the appreciation and recognition of brightness: brightness agnosia?

    NARCIS (Netherlands)

    Nijboer, T.C.W.; Nys, G.M.S.; van der Smagt, M.J.; de Haan, E.H.F.

    2009-01-01

    We report a patient with extensive brain damage in the right hemisphere who demonstrated a severe impairment in the appreciation of brightness. Acuity, contrast sensitivity as well as luminance discrimination were normal, suggesting her brightness impairment is not a mere consequence of low-level

  12. A selective deficit in the appreciation and recognition of brightness: brightness agnosia?

    Science.gov (United States)

    Nijboer, Tanja C W; Nys, Gudrun M S; van der Smagt, Maarten J; de Haan, Edward H F

    2009-01-01

    We report a patient with extensive brain damage in the right hemisphere who demonstrated a severe impairment in the appreciation of brightness. Acuity, contrast sensitivity as well as luminance discrimination were normal, suggesting her brightness impairment is not a mere consequence of low-level sensory impairments. The patient was not able to indicate the darker or the lighter of two grey squares, even though she was able to see that they differed. In addition, she could not indicate whether the lights in a room were switched on or off, nor was she able to differentiate between normal greyscale images and inverted greyscale images. As the patient recognised objects, colours, and shapes correctly, the impairment is specific for brightness. As low-level, sensory processing is normal, this specific deficit in the recognition and appreciation of brightness appears to be of a higher, cognitive level, the level of semantic knowledge. This appears to be the first report of 'brightness agnosia'.

  13. High brightness semiconductor lasers with reduced filamentation

    DEFF Research Database (Denmark)

    McInerney, John; O'Brien, Peter.; Skovgaard, Peter M. W.

    1999-01-01

    High brightness semiconductor lasers have applications in spectroscopy, fiber lasers, manufacturing and materials processing, medicine and free space communication or energy transfer. The main difficulty associated with high brightness is that, because of COD, high power requires a large aperture....... Large apertures result in high order transverse modes, filamentation and spatio-temporal instabilities, all of which degrade spatial coherence and therefore brightness. We shall describe a combined assault on three fronts: (1) minimise aperture size required for a given power by maximising the facet...... damage threshold, (2) for a given aperture, minimise self-focusing and filamentation by minimising the effective nonlinear coefficient (the alpha parameter), and (3) for a given aperture and nonlinear coefficient, develop optical cavities and propagation structures to suppress filamentation and high...

  14. On the Brightness of Supernova Ia

    CERN Document Server

    Zheng, Yijia

    2013-01-01

    Before 1998 the universe expansion was thought to be slowing down. After 1998 the universe expansion is thought to be accelerating up. The key evidence came from the observed brightness of high redshift supernovae Ia in 1998. Astronomers found that the observed brightness of high redshift supernovae Ia is fainter than expected. Astronomers believe this means that the universe expansion is accelerating up. In this paper it is argued that if the ionized gas in the universe space is taken into account, then the brightness of the high redshift supernova Ia should be fainter than expected. The universe expansion does not need to be accelerating up. The exotic form of energy (dark energy) does not need to be introduce

  15. THE ATACAMA COSMOLOGY TELESCOPE: BEAM MEASUREMENTS AND THE MICROWAVE BRIGHTNESS TEMPERATURES OF URANUS AND SATURN

    Energy Technology Data Exchange (ETDEWEB)

    Hasselfield, Matthew [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08544 (United States); Moodley, Kavilan [Astrophysics and Cosmology Research Unit, School of Mathematics, Statistics, and Computer Science, University of KwaZulu-Natal, Durban 4041 (South Africa); Bond, J. Richard; Hajian, Amir; Hincks, Adam D.; Nolta, Michael R. [Canadian Institute for Theoretical Astrophysics, University of Toronto, Toronto, ON M5S 3H8 (Canada); Das, Sudeep [High Energy Physics Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, IL 60439 (United States); Devlin, Mark J.; Marsden, Danica; Schmitt, Benjamin L. [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Dunkley, Joanna [Department of Astrophysics, Oxford University, Oxford OX1 3RH (United Kingdom); Dünner, Rolando; Gallardo, Patricio [Departamento de Astronomía y Astrofísica, Facultad de Física, Pontificía Universidad Católica, Casilla 306, Santiago 22 (Chile); Fowler, Joseph W.; Niemack, Michael D. [NIST Quantum Devices Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305 (United States); Gralla, Megan B.; Marriage, Tobias A. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686 (United States); Halpern, Mark [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC V6T 1Z4 (Canada); Page, Lyman A. [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Partridge, Bruce [Department of Physics and Astronomy, Haverford College, Haverford, PA 19041 (United States); and others

    2013-11-01

    We describe the measurement of the beam profiles and window functions for the Atacama Cosmology Telescope (ACT), which operated from 2007 to 2010 with kilopixel bolometer arrays centered at 148, 218, and 277 GHz. Maps of Saturn are used to measure the beam shape in each array and for each season of observations. Radial profiles are transformed to Fourier space in a way that preserves the spatial correlations in the beam uncertainty to derive window functions relevant for angular power spectrum analysis. Several corrections are applied to the resulting beam transforms, including an empirical correction measured from the final cosmic microwave background (CMB) survey maps to account for the effects of mild pointing variation and alignment errors. Observations of Uranus made regularly throughout each observing season are used to measure the effects of atmospheric opacity and to monitor deviations in telescope focus over the season. Using the WMAP-based calibration of the ACT maps to the CMB blackbody, we obtain precise measurements of the brightness temperatures of the Uranus and Saturn disks at effective frequencies of 149 and 219 GHz. For Uranus we obtain thermodynamic brightness temperatures T{sub U}{sup 149}= 106.7 ± 2.2 K and T{sub U}{sup 219}= 100.1 ± 3.1 K. For Saturn, we model the effects of the ring opacity and emission using a simple model and obtain resulting (unobscured) disk temperatures of T{sub S}{sup 149}= 137.3 ± 3.2 K and T{sub S}{sup 219}= 137.3 ± 4.7 K.

  16. GPM GMI Level 1B Brightness Temperatures VV03A

    Data.gov (United States)

    National Aeronautics and Space Administration — The 1BGMI algorithm uses a non-linear three-point in-flight calibration to derive antenna temperature (Ta) and convert Ta to Tb using GMI antenna pattern...

  17. GPM GMI Level 1B Brightness Temperatures V03

    Data.gov (United States)

    National Aeronautics and Space Administration — The 1BGMI algorithm uses a non-linear three-point in-flight calibration to derive antenna temperature (Ta) and convert Ta to Tb using GMI antenna pattern...

  18. Microwave brightness temperature imaging and dielectric properties ...

    Indian Academy of Sciences (India)

    material collected by former Soviet Union robots and Apollo astronauts. With the completion of the first round of lunar exploration by human beings, the study of lunar microwave brightness tempe- rature was completely forgotten. Accompanied by a new upcoming era of lunar exploration and the development of science and ...

  19. Dark matter in low surface brightness galaxies

    NARCIS (Netherlands)

    de Blok, WJG; McGaugh, SS; Persic, M; Salucci, P

    1997-01-01

    Low Surface Brightness (LSB) galaxies form a large population of disc galaxies that extend the Hubble sequence towards extreme late-types. They are only slowly evolving, and still in an early evolutionary state. The Tully-Fisher relation and rotation curves of LSB galaxies both show that LSB

  20. Robust fitting of diurnal brightness temperature cycle

    CSIR Research Space (South Africa)

    Udahemuka, G

    2007-11-01

    Full Text Available for a pixel concerned. Robust fitting of observed Diurnal Temperature Cycle (DTC) taken over a day of a given pixel without cloud cover and other abnormally conditions such as fire can give a data based brightness temperature model for a given pixel...

  1. Simultaneous brightness contrast of foraging Papilio butterflies

    Science.gov (United States)

    Kinoshita, Michiyo; Takahashi, Yuki; Arikawa, Kentaro

    2012-01-01

    This study focuses on the sense of brightness in the foraging Japanese yellow swallowtail butterfly, Papilio xuthus. We presented two red discs of different intensity on a grey background to butterflies, and trained them to select one of the discs. They were successfully trained to select either a high intensity or a low intensity disc. The trained butterflies were tested on their ability to perceive brightness in two different protocols: (i) two orange discs of different intensity presented on the same intensity grey background and (ii) two orange discs of the same intensity separately presented on a grey background that was either higher or lower in intensity than the training background. The butterflies trained to high intensity red selected the orange disc of high intensity in protocol 1, and the disc on the background of low intensity grey in protocol 2. We obtained similar results in another set of experiments with purple discs instead of orange discs. The choices of the butterflies trained to low intensity red were opposite to those just described. Taken together, we conclude that Papilio has the ability to learn brightness and darkness of targets independent of colour, and that they have the so-called simultaneous brightness contrast. PMID:22179808

  2. Microwave brightness temperature imaging and dielectric properties ...

    Indian Academy of Sciences (India)

    In this paper,we give a rough analysis of the microwave brightness temperature images of the lunar disc observed using the NRAO 12 meter Telescope and Siberian Solar Radio Telescope.We also ... Center for Space Science and Applied Research, Chinese Academy of Sciences, P.O. Box 8701, Beijing 100 080, China.

  3. Dark Matter in Low Surface Brightness Galaxies

    NARCIS (Netherlands)

    Blok, W. J. G. de; McGaugh, S. S.

    1996-01-01

    Abstract: Low Surface Brightness (LSB) galaxies form a large population of disc galaxies that extend the Hubble sequence towards extreme late-types. They are only slowly evolving, and still in an early evolutionary state. The Tully-Fisher relation and rotation curves of LSB galaxies both show that

  4. Extinction in the Galaxy from surface brightnesses of ESO-LV galaxies : Testing "standard" extinction maps

    NARCIS (Netherlands)

    Choloniewski, J.; Valentijn, E. A.

    A new method for the determination of the extinction in the Galaxy is proposed. The method uses surface brightnesses of external galaxies in the B and R-bands. The observational data have been taken from the ESO-LV galaxy catalog. As a first application of our model we derive the ratio of R-band to

  5. The nature of solar brightness variations

    Science.gov (United States)

    Shapiro, A. I.; Solanki, S. K.; Krivova, N. A.; Cameron, R. H.; Yeo, K. L.; Schmutz, W. K.

    2017-09-01

    Determining the sources of solar brightness variations1,2, often referred to as solar noise3, is important because solar noise limits the detection of solar oscillations3, is one of the drivers of the Earth's climate system4,5 and is a prototype of stellar variability6,7—an important limiting factor for the detection of extrasolar planets. Here, we model the magnetic contribution to solar brightness variability using high-cadence8,9 observations from the Solar Dynamics Observatory (SDO) and the Spectral And Total Irradiance REconstruction (SATIRE)10,11 model. The brightness variations caused by the constantly evolving cellular granulation pattern on the solar surface were computed with the Max Planck Institute for Solar System Research (MPS)/University of Chicago Radiative Magnetohydrodynamics (MURaM)12 code. We found that the surface magnetic field and granulation can together precisely explain solar noise (that is, solar variability excluding oscillations) on timescales from minutes to decades, accounting for all timescales that have so far been resolved or covered by irradiance measurements. We demonstrate that no other sources of variability are required to explain the data. Recent measurements of Sun-like stars by the COnvection ROtation and planetary Transits (CoRoT)13 and Kepler14 missions uncovered brightness variations similar to that of the Sun, but with a much wider variety of patterns15. Our finding that solar brightness variations can be replicated in detail with just two well-known sources will greatly simplify future modelling of existing CoRoT and Kepler as well as anticipated Transiting Exoplanet Survey Satellite16 and PLAnetary Transits and Oscillations of stars (PLATO)17 data.

  6. Digital Elevation Models of Glacier Bay National Park, Between Lituya Bay and Icy Point, Alaska, Derived from Airborne Lidar Data Acquired in September 2015

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset provides four digital elevation models derived from airborne lidar data acquired over four separate areas along and adjacent to the Fairweather Fault...

  7. Confidence intervals for concentration and brightness from fluorescence fluctuation measurements.

    Science.gov (United States)

    Pryse, Kenneth M; Rong, Xi; Whisler, Jordan A; McConnaughey, William B; Jiang, Yan-Fei; Melnykov, Artem V; Elson, Elliot L; Genin, Guy M

    2012-09-05

    The theory of photon count histogram (PCH) analysis describes the distribution of fluorescence fluctuation amplitudes due to populations of fluorophores diffusing through a focused laser beam and provides a rigorous framework through which the brightnesses and concentrations of the fluorophores can be determined. In practice, however, the brightnesses and concentrations of only a few components can be identified. Brightnesses and concentrations are determined by a nonlinear least-squares fit of a theoretical model to the experimental PCH derived from a record of fluorescence intensity fluctuations. The χ(2) hypersurface in the neighborhood of the optimum parameter set can have varying degrees of curvature, due to the intrinsic curvature of the model, the specific parameter values of the system under study, and the relative noise in the data. Because of this varying curvature, parameters estimated from the least-squares analysis have varying degrees of uncertainty associated with them. There are several methods for assigning confidence intervals to the parameters, but these methods have different efficacies for PCH data. Here, we evaluate several approaches to confidence interval estimation for PCH data, including asymptotic standard error, likelihood joint-confidence region, likelihood confidence intervals, skew-corrected and accelerated bootstrap (BCa), and Monte Carlo residual resampling methods. We study these with a model two-dimensional membrane system for simplicity, but the principles are applicable as well to fluorophores diffusing in three-dimensional solution. Using simulated fluorescence fluctuation data, we find the BCa method to be particularly well-suited for estimating confidence intervals in PCH analysis, and several other methods to be less so. Using the BCa method and additional simulated fluctuation data, we find that confidence intervals can be reduced dramatically for a specific non-Gaussian beam profile. Copyright © 2012 Biophysical Society

  8. A very high-resolution (1 km?1 km) global fossil fuel CO2 emission inventory derived using a point source database and satellite observations of nighttime lights

    National Research Council Canada - National Science Library

    T. Oda; S. Maksyutov

    2011-01-01

    .... We developed a global 1 km×1 km annual fossil fuel CO 2 emission inventory for the years 1980-2007 by combining a worldwide point source database and satellite observations of the global nightlight distribution...

  9. Intermittent Episodes of Bright Light Suppress Myopia in the Chicken More than Continuous Bright Light

    Science.gov (United States)

    Lan, Weizhong; Feldkaemper, Marita; Schaeffel, Frank

    2014-01-01

    Purpose Bright light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of bright light are the most potent in suppressing deprivation myopia in chickens. Methods Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8) was kept under office-like illuminance (500 lux) at a 10∶14 light∶dark cycle. Episodes of bright light (15 000 lux) were super-imposed on this background as follows. Paradigm I: exposure to constant bright light for either 1 hour (n = 5), 2 hours (n = 5), 5 hours (n = 4) or 10 hours (n = 4). Paradigm II: exposure to repeated cycles of bright light with 50% duty cycle and either 60 minutes (n = 7), 30 minutes (n = 8), 15 minutes (n = 6), 7 minutes (n = 7) or 1 minute (n = 7) periods, provided for 10 hours. Refraction and axial length were measured prior to and immediately after the 5-day experiment. Relative changes were analyzed by paired t-tests, and differences among groups were tested by one-way ANOVA. Results Compared with the reference group, exposure to continuous bright light for 1 or 2 hours every day had no significant protective effect against deprivation myopia. Inhibition of myopia became significant after 5 hours of bright light exposure but extending the duration to 10 hours did not offer an additional benefit. In comparison, repeated cycles of 1∶1 or 7∶7 minutes of bright light enhanced the protective effect against myopia and could fully suppress its development. Conclusions The protective effect of bright light depends on the exposure duration and, to the intermittent form, the frequency cycle. Compared to the saturation effect of continuous bright light, low frequency cycles of bright light (1∶1 min) provided the strongest inhibition effect. However, our quantitative results probably might not be directly translated into humans, but rather need further amendments in clinical

  10. Circadian Phase-Shifting Effects of Bright Light, Exercise, and Bright Light + Exercise.

    Science.gov (United States)

    Youngstedt, Shawn D; Kline, Christopher E; Elliott, Jeffrey A; Zielinski, Mark R; Devlin, Tina M; Moore, Teresa A

    2016-02-26

    Limited research has compared the circadian phase-shifting effects of bright light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night bright light, late night exercise, and late evening bright light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of three 2.5-day protocols. Participants followed a 3-h ultra-short sleep-wake cycle, involving wakefulness in dim light for 2h, followed by attempted sleep in darkness for 1 h, repeated throughout each protocol. On night 2 of each protocol, participants received either (1) bright light alone (5,000 lux) from 2210-2340 h, (2) treadmill exercise alone from 2210-2340 h, or (3) bright light (2210-2340 h) followed by exercise from 0410-0540 h. Urine was collected every 90 min. Shifts in the 6-sulphatoxymelatonin (aMT6s) cosine acrophase from baseline to post-treatment were compared between treatments. Analyses revealed a significant additive phase-delaying effect of bright light + exercise (80.8 ± 11.6 [SD] min) compared with exercise alone (47.3 ± 21.6 min), and a similar phase delay following bright light alone (56.6 ± 15.2 min) and exercise alone administered for the same duration and at the same time of night. Thus, the data suggest that late night bright light followed by early morning exercise can have an additive circadian phase-shifting effect.

  11. Human CD56bright NK Cells

    DEFF Research Database (Denmark)

    Michel, Tatiana; Poli, Aurélie; Cuapio, Angelica

    2016-01-01

    Human NK cells can be subdivided into various subsets based on the relative expression of CD16 and CD56. In particular, CD56(bright)CD16(-/dim) NK cells are the focus of interest. They are considered efficient cytokine producers endowed with immunoregulatory properties, but they can also become...... cytotoxic upon appropriate activation. These cells were shown to play a role in different disease states, such as cancer, autoimmunity, neuroinflammation, and infection. Although their phenotype and functional properties are well known and have been extensively studied, their lineage relationship with other...... NK cell subsets is not fully defined, nor is their precise hematopoietic origin. In this article, we summarize recent studies about CD56(bright) NK cells in health and disease and briefly discuss the current controversies surrounding them....

  12. Companions of Bright Barred Shapley Ames Galaxies

    OpenAIRE

    Garcia-Barreto, J. Antonio; Carrillo, Rene; Vera-Villamizar, Nelson

    2003-01-01

    Companion galaxy environment for a subset of 78 bright and nearby barred galaxies from the Shapley Ames Catalog is presented. Among spiral barred galaxies there are Seyfert galaxies, galaxies with circumnuclear structures, galaxies not associated with any large scale galaxy cloud structure, galaxies with peculiar disk morphology (crooked arms) and galaxies with normal disk morphology; the list includes all Hubble types. The companion galaxy list includes number of companion galaxies within 20...

  13. Modular Zero Energy. BrightBuilt Home

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [Steven Winter Associates, Inc., Norwalk, CT (United States); Butterfield, Karla [Steven Winter Associates, Inc., Norwalk, CT (United States)

    2016-03-01

    With funding from the Building America Program, part of the U.S. Department of Energy Building Technologies Office, the Consortium for Advanced Residential Buildings (CARB) worked with BrightBuilt Home (BBH) to evaluate and optimize building systems. CARB’s work focused on a home built by Black Bros. Builders in Lincolnville, Maine (International Energy Conservation Code Climate Zone 6). As with most BBH projects to date, modular boxes were built by Keiser Homes in Oxford, Maine.

  14. TC4 AMPR BRIGHTNESS TEMPERATURE (TB) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The TC4 AMPR Brightness Temperature (TB) dataset consists of brightness temperature data from July 19, 2007 through August 8, 2007. The Tropical Composition, Cloud...

  15. Brightness illusion in the guppy (Poecilia reticulata).

    Science.gov (United States)

    Agrillo, Christian; Miletto Petrazzini, Maria Elena; Bisazza, Angelo

    2016-02-01

    A long-standing debate surrounds the issue of whether human and nonhuman species share similar perceptual mechanisms. One experimental strategy to compare visual perception of vertebrates consists in assessing how animals react in the presence of visual illusions. To date, this methodological approach has been widely used with mammals and birds, while few studies have been reported in distantly related species, such as fish. In the present study we investigated whether fish perceive the brightness illusion, a well-known illusion occurring when 2 objects, identical in physical features, appear to be different in brightness. Twelve guppies (Poecilia reticulata) were initially trained to discriminate which rectangle was darker or lighter between 2 otherwise identical rectangles. Three different conditions were set up: neutral condition between rectangle and background (same background used for both darker and lighter rectangle); congruent condition (darker rectangle in a darker background and lighter rectangle in a lighter background); and incongruent condition (darker rectangle in a lighter background and lighter rectangle in a darker background). After reaching the learning criterion, guppies were presented with the illusory pattern: 2 identical rectangles inserted in 2 different backgrounds. Guppies previously trained to select the darker rectangle showed a significant choice of the rectangle that appears to be darker by human observers (and vice versa). The human-like performance exhibited in the presence of the illusory pattern suggests the existence of similar perceptual mechanisms between humans and fish to elaborate the brightness of objects. (c) 2016 APA, all rights reserved).

  16. A time-dependent search for high-energy neutrinos from bright GRBs with ANTARES

    Directory of Open Access Journals (Sweden)

    Celli Silvia

    2017-01-01

    Full Text Available Astrophysical point-like neutrino sources, like Gamma-Ray Bursts (GRBs, are one of the main targets for neutrino telescopes, since they are among the best candidates for Ultra-High-Energy Cosmic Ray (UHECR acceleration. From the interaction between the accelerated protons and the intense radiation fields of the source jet, charged mesons are produced, which then decay into neutrinos. The methods and the results of a search for high-energy neutrinos in spatial and temporal correlation with the detected gamma-ray emission are presented for four bright GRBs observed between 2008 and 2013: a time-dependent analysis, optimised for each flare of the selected bursts, is performed to predict detailed neutrino spectra. The internal shock scenario of the fireball model is investigated, relying on the neutrino spectra computed through the numerical code NeuCosmA. The analysis is optimized on a per burst basis, through the maximization of the signal discovery probability. Since no events in ANTARES data passed the optimised cuts, 90% C.L. upper limits are derived on the expected neutrino fluences.

  17. Random Capillary Blood Glucose Cut Points for Diabetes and Pre-Diabetes Derived From Community-Based Opportunistic Screening in India

    Science.gov (United States)

    Somannavar, Suresh; Ganesan, Anbazhagan; Deepa, Mohan; Datta, Manjula; Mohan, Viswanathan

    2009-01-01

    OBJECTIVE To determine random capillary blood glucose (RCBG) cut points that discriminate diabetic and pre-diabetic subjects from normal individuals. RESEARCH DESIGN AND METHODS RCBG was performed in 1,333 individuals randomly chosen from 63,305 individuals who had participated in an opportunistic screening program. An oral glucose tolerance test was also performed by venous plasma glucose on an autoanalyzer. RCBG cut points that discriminate diabetes, impaired glucose tolerance (IGT), and impaired fasting glucose (IFG) were determined using receiver operating characteristic curves. RESULTS Using 2-h plasma glucose ≥200 mg/dl (11.1 mmol/l) criterion, the RCBG cut point of 140 mg/dl (7.7 mmol/l) gave the highest sensitivity and specificity. For 2-h plasma glucose ≥200 mg/dl (11.1 mmol/l) and fasting plasma glucose (FPG) ≥126 mg/dl (7.0 mmol/l) criteria, either 2-h plasma glucose ≥200 mg/dl (11.1 mmol/l) or FPG ≥126 mg/dl (7.0 mmol/l) criterion, and the FPG ≥126 mg/dl (7.0 mmol/l) criterion, RCBG cut point was 143 mg/dl (7.9 mmol/l). RCBG cut points for IGT, IFG according to World Health Organization criterion, and IFG according to American Diabetes Association criterion were 119 mg/dl (6.6 mmol/l), 118 mg/dl (6.6 mmol/l), and 113 mg/dl (6.3 mmol/l), respectively. CONCLUSIONS Asian Indians with RCBG >110 mg/dl at screening can be recommended to undergo definitive testing. PMID:19073758

  18. The impact of melt ponds on summertime microwave brightness temperatures and sea-ice concentrations

    DEFF Research Database (Denmark)

    Kern, Stefan; Rösel, Anja; Pedersen, Leif Toudal

    2016-01-01

    Sea-ice concentrations derived from satellite microwave brightness temperatures are less accurate during summer. In the Arctic Ocean the lack of accuracy is primarily caused by melt ponds, but also by changes in the properties of snow and the sea-ice surface itself. We investigate the sensitivity...... of eight sea-ice concentration retrieval algorithms to melt ponds by comparing sea-ice concentration with the melt-pond fraction. We derive gridded daily sea-ice concentrations from microwave brightness temperatures of summer 2009. We derive the daily fraction of melt ponds, open water between ice floes......, and the ice-surface fraction from contemporary Moderate Resolution Spectroradiometer (MODIS) reflectance data. We only use grid cells where the MODIS sea ice concentration, which is the melt-pond fraction plus the ice-surface fraction, exceeds 90 %. For one group of algorithms, e.g., Bristol and Comiso...

  19. Three Millisecond Pulsars in Fermi LAT Unassociated Bright Sources

    Science.gov (United States)

    Ransom, S. M.; Ray, P. S.; Camilo, F.; Roberts, M. S. E.; Celik, O.; Wolff, M. T.; Cheung, C. C.; Kerr, M.; Pennucci, T.; DeCesar, M. E.; hide

    2010-01-01

    We searched for radio pulsars in 25 of the non-variable, unassociated sources in the Fermi LAT Bright Source List with the Green Bank Telescope at 820 MHz. We report the discovery of three radio and gamma-ray millisecond pulsar (MSPs) from a high Galactic latitude subset of these sources. All of the pulsars are in binary systems, which would have made them virtually impossible to detect in blind gamma-ray pulsation searches. They seem to be relatively normal, nearby (pulsars are power law in nature with exponential cutoffs at a few Ge V, as has been found with most other pulsars. The MSPs have all been detected as X-ray point sources. Their soft X-ray luminosities of approx 10(exp 30) - 10(exp 31) erg/s are typical of the rare radio MSPs seen in X-rays.

  20. Tipping Point

    Medline Plus

    Full Text Available ... OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture ...

  1. Study of Three-Dimensional Image Brightness Loss in Stereoscopy

    OpenAIRE

    Hsing-Cheng Yu; Xie-Hong Tsai; An-Chun Luo; Ming Wu; Sei-Wang Chen

    2015-01-01

    When viewing three-dimensional (3D) images, whether in cinemas or on stereoscopic televisions, viewers experience the same problem of image brightness loss. This study aims to investigate image brightness loss in 3D displays, with the primary aim being to quantify the image brightness degradation in the 3D mode. A further aim is to determine the image brightness relationship to the corresponding two-dimensional (2D) images in order to adjust the 3D-image brightness values. In addition, the ph...

  2. Investigating the Bright End of LSST Photometry

    Science.gov (United States)

    Ojala, Elle; Pepper, Joshua; LSST Collaboration

    2018-01-01

    The Large Synoptic Survey Telescope (LSST) will begin operations in 2022, conducting a wide-field, synoptic multiband survey of the southern sky. Some fraction of objects at the bright end of the magnitude regime observed by LSST will overlap with other wide-sky surveys, allowing for calibration and cross-checking between surveys. The LSST is optimized for observations of very faint objects, so much of this data overlap will be comprised of saturated images. This project provides the first in-depth analysis of saturation in LSST images. Using the PhoSim package to create simulated LSST images, we evaluate saturation properties of several types of stars to determine the brightness limitations of LSST. We also collect metadata from many wide-field photometric surveys to provide cross-survey accounting and comparison. Additionally, we evaluate the accuracy of the PhoSim modeling parameters to determine the reliability of the software. These efforts will allow us to determine the expected useable data overlap between bright-end LSST images and faint-end images in other wide-sky surveys. Our next steps are developing methods to extract photometry from saturated images.This material is based upon work supported in part by the National Science Foundation through Cooperative Agreement 1258333 managed by the Association of Universities for Research in Astronomy (AURA), and the Department of Energy under Contract No. DE-AC02-76SF00515 with the SLAC National Accelerator Laboratory. Additional LSST funding comes from private donations, grants to universities, and in-kind support from LSSTC Institutional Members.Thanks to NSF grant PHY-135195 and the 2017 LSSTC Grant Award #2017-UG06 for making this project possible.

  3. Dark and Bright Ridges on Europa

    Science.gov (United States)

    1998-01-01

    This high-resolution image of Jupiter's moon Europa, taken by NASA's Galileo spacecraft camera, shows dark, relatively smooth region at the lower right hand corner of the image which may be a place where warm ice has welled up from below. The region is approximately 30 square kilometers in area. An isolated bright hill stands within it. The image also shows two prominent ridges which have different characteristics; youngest ridge runs from left to top right and is about 5 kilometers in width (about 3.1 miles). The ridge has two bright, raised rims and a central valley. The rims of the ridge are rough in texture. The inner and outer walls show bright and dark debris streaming downslope, some of it forming broad fans. This ridge overlies and therefore must be younger than a second ridge running from top to bottom on the left side of the image. This dark 2 km wide ridge is relatively flat, and has smaller-scale ridges and troughs along its length.North is to the top of the picture, and the sun illuminates the surface from the upper left. This image, centered at approximately 14 degrees south latitude and 194 degrees west longitude, covers an area approximately 15 kilometers by 20 kilometers (9 miles by 12 miles). The resolution is 26 meters (85 feet) per picture element. This image was taken on December 16, 1997 at a range of 1300 kilometers (800 miles) by Galileo's solid state imaging system.The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

  4. An exceptionally bright, compact starburst nucleus

    Science.gov (United States)

    Margon, Bruce; Anderson, Scott F.; Mateo, Mario; Fich, Michel; Massey, Philip

    1988-01-01

    Observations are reported of a remarkably bright (V about 13) starburst nucleus, 0833 + 652, which has been detected at radio, infrared, optical, ultraviolet, and X-ray wavelengths. Despite an observed flux at each of these wavelengths which is comparable to that of NGC 7714, often considered the 'prototypical' example of the starburst phenomenon, 0833 + 652 appears to be a previously uncataloged object. Its ease of detectability throughout the electromagnetic spectrum should make it useful for a variety of problems in the study of compact emission-line galaxies.

  5. Broadband bright twin beams and their upconversion

    Science.gov (United States)

    Chekhova, Maria V.; Germanskiy, Semen; Horoshko, Dmitri B.; Kitaeva, Galiya Kh.; Kolobov, Mikhail I.; Leuchs, Gerd; Phillips, Chris R.; Prudkovskii, Pavel A.

    2018-02-01

    We report on the observation of broadband (40 THz) bright twin beams through high-gain parametric down-conversion in an aperiodically poled lithium niobate crystal. The output photon number is shown to scale exponentially with the pump power and not with the pump amplitude, as in homogeneous crystals. Photon-number correlations and the number of frequency/temporal modes are assessed by spectral covariance measurements. By using sum-frequency generation on the surface of a non-phasematched crystal, we measure a cross-correlation peak with the temporal width 90 fs.

  6. Chandra's Darkest Bright Star: not so Dark after All?

    Science.gov (United States)

    Ayres, Thomas R.

    2008-11-01

    The Chandra High Resolution camera (HRC) has obtained numerous short exposures of the ultraviolet (UV)-bright star Vega (α Lyrae; HD 172167: A0 V), to calibrate the response of the detector to out-of-band (non-X-ray) radiation. A new analysis uncovered a stronger "blue leak" in the imaging section (HRC-I) than reported in an earlier study of Vega based on a subset of the pointings. The higher count rate—a factor of nearly 2 above prelaunch estimates—raised the possibility that genuine coronal X-rays might lurk among the out-of-band events. Exploiting the broader point-spread function of the UV leak compared with soft X-rays identified an excess of counts centered on the target, technically at 3σ significance. A number of uncertainties, however, prevent a clear declaration of a Vegan corona. A more secure result would be within reach of a deep uninterrupted HRC-I pointing.

  7. Estimating two-point statistics from derivatives of a signal containing noise: Application to auto-correlation functions of turbulent Lagrangian tracks.

    Science.gov (United States)

    Machicoane, N; Huck, P D; Volk, R

    2017-06-01

    This article describes a method for calculating moments and correlation functions of signal derivatives, which were rid of experimental noise without the use of filtering operations. The method is based on the computation of the ensemble-average of different time (or spatial) increments of the signal. The hypotheses are that the noise is white and not correlated with the signal; however, the method is also shown to work with colored noise. The method is first developed, considering white noise, and benchmarked with synthetic trajectories containing noise with variable signal-to-noise ratios. It is then tested on experimental trajectories in the context of Lagrangian tracking of particles in turbulent flows, either containing a short-correlated noise or a colored noise.

  8. Estimating two-point statistics from derivatives of a signal containing noise: Application to auto-correlation functions of turbulent Lagrangian tracks

    Science.gov (United States)

    Machicoane, N.; Huck, P. D.; Volk, R.

    2017-06-01

    This article describes a method for calculating moments and correlation functions of signal derivatives, which were rid of experimental noise without the use of filtering operations. The method is based on the computation of the ensemble-average of different time (or spatial) increments of the signal. The hypotheses are that the noise is white and not correlated with the signal; however, the method is also shown to work with colored noise. The method is first developed, considering white noise, and benchmarked with synthetic trajectories containing noise with variable signal-to-noise ratios. It is then tested on experimental trajectories in the context of Lagrangian tracking of particles in turbulent flows, either containing a short-correlated noise or a colored noise.

  9. Subpicosecond, high-brightness excimer laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, A.J.; Gosnell, T.R.; Roberts, J.P.; Lester, C.S.; Gibson, R.B.; Harper, S.E.; Tallman, C.R.

    1988-01-01

    Subpicosecond, high-brightness excimer laser systems are being used to explore the interaction of intense coherent ultraviolet radiation with matter. Applications of current systems include generation of picosecond x-ray pulses, investigation of possible x-ray laser pumping schemes, studies of multiphoton phenomena in atomic species, and time-resolved photochemistry. These systems, based on the amplification of subpicosecond pulses in small aperture (/approximately/1 cm/sup 2/) XeCl or KrF amplifiers, deliver focal spot intensities of /approximately/10/sup 17/ W/cm/sup 2/. Scaling to higher intensities, however, will require an additional large aperture amplifier which preserves near-diffraction-limited beam quality and subpicosecond pulse duration. We describe here both a small aperture KrF system which routinely provides intensities >10/sup 17/ W/cm/sup 2/ to several experiments, and a large aperture XeCl system designed to deliver /approximately/1 J subpicosecond pulses and yield intensities on target in excess of 10/sup 19/W/cm/sup 2/. We also discuss the effects of two-photon absorption on large-aperture, high-brightness excimer lasers. 4 refs., 2 figs.

  10. Optical Sky Brightness at Dome C, Antarctica

    Science.gov (United States)

    Kenyon, S.; Storey, J. W. V.; Burton, M. G.

    2006-08-01

    Dome C, Antarctica is a prime site for astronomical observations in terms of climate, wind speeds and turbulence. The infrared and terahertz sky backgrounds are the lowest of any inhabited place on Earth. However, at present little is known about the optical sky brightness and atmospheric extinction. Using a variety of modelling techniques together with data from the South Pole, we estimate the brightness of the night sky including the contributions from scattered sunlight, moonlight, aurorae, airglow, zodiacal light and artificial sources. We compare our results to another prime astronomical site, Mauna Kea. We find moonlight has significantly less effect at Dome C than at Mauna Kea. Aurorae are expected to have a minor impact at both sites, and zodiacal light is expected to be less at Dome C than at Mauna Kea. Airglow emissions at Dome C are expected to be similar to those at temperate sites. With proper planning, artificial sources of light pollution should be non-existent. The overall atmospheric extinction, or opacity, is expected to be the minimum possible. We conclude that Dome C is a very promising site not only for infrared and terahertz astronomy, but for optical astronomy as well..

  11. Sublimation in bright spots on (1) Ceres

    Science.gov (United States)

    Nathues, A.; Hoffmann, M.; Schaefer, M.; Le Corre, L.; Reddy, V.; Platz, T.; Cloutis, E. A.; Christensen, U.; Kneissl, T.; Li, J.-Y.; Mengel, K.; Schmedemann, N.; Schaefer, T.; Russell, C. T.; Applin, D. M.; Buczkowski, D. L.; Izawa, M. R. M.; Keller, H. U.; O'Brien, D. P.; Pieters, C. M.; Raymond, C. A.; Ripken, J.; Schenk, P. M.; Schmidt, B. E.; Sierks, H.; Sykes, M. V.; Thangjam, G. S.; Vincent, J.-B.

    2015-12-01

    The dwarf planet (1) Ceres, the largest object in the main asteroid belt with a mean diameter of about 950 kilometres, is located at a mean distance from the Sun of about 2.8 astronomical units (one astronomical unit is the Earth-Sun distance). Thermal evolution models suggest that it is a differentiated body with potential geological activity. Unlike on the icy satellites of Jupiter and Saturn, where tidal forces are responsible for spewing briny water into space, no tidal forces are acting on Ceres. In the absence of such forces, most objects in the main asteroid belt are expected to be geologically inert. The recent discovery of water vapour absorption near Ceres and previous detection of bound water and OH near and on Ceres (refs 5, 6, 7) have raised interest in the possible presence of surface ice. Here we report the presence of localized bright areas on Ceres from an orbiting imager. These unusual areas are consistent with hydrated magnesium sulfates mixed with dark background material, although other compositions are possible. Of particular interest is a bright pit on the floor of crater Occator that exhibits probable sublimation of water ice, producing haze clouds inside the crater that appear and disappear with a diurnal rhythm. Slow-moving condensed-ice or dust particles may explain this haze. We conclude that Ceres must have accreted material from beyond the ‘snow line’, which is the distance from the Sun at which water molecules condense.

  12. Empirical Approach to Cepheid Period-Luminosity-Color and Period-Luminosity Relations by Surface Brightness

    Science.gov (United States)

    di Benedetto, G. P.

    1995-10-01

    Empirical period-luminosity-color and period-luminosity (PLC [V, B-V] and PL[V] relations according to Stefan's law are derived for Cepheid variables by applying thermal scales of nonvariable giant and supergiant stars established by modern observational interferometry. Intrinsic surface brightnesses are predicted by the apparent color index V - K as fiducial reference unbiased by metallicity and gravity effects, along with current optical absorption data. Linear radii are inferred from periods through the period-radius relation, assumed to be insensitive to abundance and brightness variations. The dependence of PLC and PL zero points to abundance effects is further investigated. I compare current Cepheid data from our metal- normal Galaxy (GAL) with those in the Magellanic Clouds (LMC and SMC) of poorer metal content. The major achievement is that the PL(V) relations are found to be severely biased by metallicity, whereas the PLC(V, B- V) relations turn out to be much less affected by abundances than previously expected. The new PLC and PL relations calibrated on fundamental quantities are compared with those from the classical zero-age main-sequence (ZAMS) fitting empirical approach. It is shown that all metal-normal equations lead to remarkably consistent luminosities of GAL Cepheids, to within +/- 0.05 mag (PL) and +/- 0.02 mag (PLC), whereas metal-poor LMC and SMC results appear to be significantly discrepant. It is emphasized that theoretical thermal scales applied for the derivation of ZAMS metal- corrected relations, either explicit or implicit, are mainly responsible for such observed discrepancies. The actual empirical approach appears to overcome most of the previous difficulties closely related to the poor knowledge of Cepheid thermal properties. Theoretical Cepheid thermal scales are critically reviewed. It is found that recent metal-normal color-brightness relations lead to results remarkably consistent with those from observational scales, whereas

  13. Simultaneous determination of lovastatin and niacin in tablet by first and third derivative spectrophotometry and H-point standard addition methods.

    Science.gov (United States)

    Kazemipour, M; Ansari, M; Ramezani, H; Moradalizadeh, M

    2012-04-01

    Most cardiovascular diseases need to be treated by more than a simple drug and the use of combination products diminishes noncompliance. Advicor(®) as a combination product of a vitamin and a fat lowering agent has no monograph in official pharmacopeias for its quality control purposes. In this study, first and third derivative signals for NA and LV quantitation at the two pairs of wavelengths, 261 and 273 nm; 245 and 249 nm were monitored with the addition of standard solutions of NA or LV, respectively. The limits of detection were 0.03 and 0.32 mg/L for LV and NA, respectively. The limits of quantitation were 0.09 and 0.78 mg/L for LV and NA, respectively. RSD% for both interday and intraday precision was lower than 2.6 and 2.7% for LV and NA, respectively. Selectivity of the method was assessed for both degradation products produced in stress conditions and common excipients that may present in the pharmaceutical dosage forms. The recommended procedure was successfully applied to real samples.

  14. Points to consider for a validation study of iPS cell-derived cardiomyocytes using a multi-electrode array system.

    Science.gov (United States)

    Kanda, Yasunari; Yamazaki, Daiju; Kurokawa, Junko; Inutsuka, Takashi; Sekino, Yuko

    2016-01-01

    Human induced pluripotent stem cell-derived cardiomyocytes (iPS-CMs) provide a novel assay system to assess cardiac safety in drug development to overcome a problem of species difference in non-clinical testing during drug development. Using the multi-electrode array (MEA) platform, electrophysiological activities of iPS-CMs can be recorded easily to assess QT prolongation and proarrhythmic potential of drug candidates. Here we have established a standardized protocol to evaluate the possibility of iPS-CMs, and shared the protocol with an international consortium. To obtain reproducible and reliable experimental data from these cells, we determined the optimal experimental conditions, such as cell density, MEA coating, culture conditions, high-pass filter frequency, definition of early afterdepolarization or triggered activity, and calibration compounds. Based on the protocol, our validation study using 60 compounds is in progress. Thus, MEA-based experiments using iPS-CMs would be a standard testing method to evaluate QT prolongation and proarrhythmic potentials. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  15. The Voxel-Wise Functional Connectome Can Be Efficiently Derived from Co-activations in a Sparse Spatio-Temporal Point-Process.

    Science.gov (United States)

    Tagliazucchi, Enzo; Siniatchkin, Michael; Laufs, Helmut; Chialvo, Dante R

    2016-01-01

    Large efforts are currently under way to systematically map functional connectivity between all pairs of millimeter-scale brain regions based on large neuroimaging databases. The exploratory unraveling of this "functional connectome" based on functional Magnetic Resonance Imaging (fMRI) can benefit from a better understanding of the contributors to resting state functional connectivity. In this work, we introduce a sparse representation of fMRI data in the form of a discrete point-process encoding high-amplitude events in the blood oxygenation level-dependent (BOLD) signal and we show it contains sufficient information for the estimation of functional connectivity between all pairs of voxels. We validate this method by replicating results obtained with standard whole-brain voxel-wise linear correlation matrices in two datasets. In the first one (n = 71), we study the changes in node strength (a measure of network centrality) during deep sleep. The second is a large database (n = 1147) of subjects in which we look at the age-related reorganization of the voxel-wise network of functional connections. In both cases it is shown that the proposed method compares well with standard techniques, despite requiring only data on the order of 1% of the original BOLD signal time series. Furthermore, we establish that the point-process approach does not reduce (and in one case increases) classification accuracy compared to standard linear correlations. Our results show how large fMRI datasets can be drastically simplified to include only the timings of large-amplitude events, while still allowing the recovery of all pair-wise interactions between voxels. The practical importance of this dimensionality reduction is manifest in the increasing number of collaborative efforts aiming to study large cohorts of healthy subjects as well as patients suffering from brain disease. Our method also suggests that the electrophysiological signals underlying the dynamics of fMRI time series

  16. The voxel-wise functional connectome can be efficiently derived from co-activations in a sparse spatio-temporal point-process

    Directory of Open Access Journals (Sweden)

    Enzo Tagliazucchi

    2016-08-01

    Full Text Available Large efforts are currently under way to systematically map functional connectivity between all pairs of millimeter-scale brain regions based on large neuroimaging databases. The exploratory unraveling of this functional connectome based on functional Magnetic Resonance Imaging (fMRI can benefit from a better understanding of the contributors to resting state functional connectivity. In this work, we introduce a sparse representation of fMRI data in the form of a discrete point-process encoding high-amplitude events in the blood oxygenation level-dependent (BOLD signal and we show it contains sufficient information for the estimation of functional connectivity between all pairs of voxels. We validate this method by replicating results obtained with standard whole-brain voxel-wise linear correlation matrices in two datasets. In the first one (n=71, we study the changes in node strength (a measure of network centrality during deep sleep. The second is a large database (n=1147 of subjects in which we look at the age-related reorganization of the voxel-wise network of functional connections. In both cases it is shown that the proposed method compares well with standard techniques, despite requiring only data on the order of 1% of the original BOLD signal time series. Furthermore, we establish that the point-process approach does not reduce (and in one case increases classification accuracy compared to standard linear correlations. Our results show how large fMRI datasets can be drastically simplified to include only the timings of large-amplitude events, while still allowing the recovery of all pair-wise interactions between voxels. The practical importance of this dimensionality reduction is manifest in the increasing number of collaborative efforts aiming to study large cohorts of healthy subjects as well as patients suffering from brain disease. Our method also suggests that the electrophysiological signals underlying the dynamics of fMRI time

  17. Non-Markovian Quantum Friction of Bright Solitons in Superfluids.

    Science.gov (United States)

    Efimkin, Dmitry K; Hofmann, Johannes; Galitski, Victor

    2016-06-03

    We explore the quantum dynamics of a bright matter-wave soliton in a quasi-one-dimensional bosonic superfluid with attractive interactions. Specifically, we focus on the dissipative forces experienced by the soliton due to its interaction with Bogoliubov excitations. Using the collective coordinate approach and the Keldysh formalism, a Langevin equation of motion for the soliton is derived from first principles. The equation contains a stochastic Langevin force (associated with quantum noise) and a nonlocal in time dissipative force, which appears due to inelastic scattering of Bogoliubov quasiparticles off of the moving soliton. It is shown that Ohmic friction (i.e., a term proportional to the soliton's velocity) is absent in the integrable setup. However, the Markovian approximation gives rise to the Abraham-Lorentz force (i.e., a term proportional to the derivative of the soliton's acceleration), which is known from classical electrodynamics of a charged particle interacting with its own radiation. These Abraham-Lorentz equations famously contain a fundamental causality paradox, where the soliton (particle) interacts with excitations (radiation) originating from future events. We show, however, that the causality paradox is an artifact of the Markovian approximation, and our exact non-Markovian dissipative equations give rise to physical trajectories. We argue that the quantum friction discussed here should be observable in current quantum gas experiments.

  18. Mesospheric Temperatures over Apache Point Observatory (32°N, 105°W) Derived from Sloan Digital Sky Survey Spectra

    Science.gov (United States)

    Kim, Gawon; Kim, Yong Ha; Lee, Young Sun

    2017-06-01

    We retrieved rotational temperatures from emission lines of the OH airglow (8-3) band in the sky spectra of the Sloan digital sky survey (SDSS) for the period 2000-2014, as part of the astronomical observation project conducted at the Apache Point observatory (32°N, 105°W). The SDSS temperatures show a typical seasonal variation of mesospheric temperature: low in summer and high in winter. We find that the temperatures respond to solar activity by as much as 1.2 K ±0.8 K per 100 solar flux units, which is consistent with other studies in mid-latitude regions. After the seasonal variation and solar response were subtracted, the SDSS temperature is fairly constant over the 15 year period, unlike cooling trends suggested by some studies. This temperature analysis using SDSS spectra is a unique contribution to the global monitoring of climate change because the SDSS project was established for astronomical purposes and is independent from climate studies. The SDSS temperatures are also compared with mesospheric temperatures measured by the microwave limb sounder (MLS) instrument on board the Aura satellite and the differences are discussed.

  19. Maximum current density and beam brightness achievable by laser-driven electron sources

    Directory of Open Access Journals (Sweden)

    D. Filippetto

    2014-02-01

    Full Text Available This paper discusses the extension to different electron beam aspect ratio of the Child-Langmuir law for the maximum achievable current density in electron guns. Using a simple model, we derive quantitative formulas in good agreement with simulation codes. The new scaling laws for the peak current density of temporally long and transversely narrow initial beam distributions can be used to estimate the maximum beam brightness and suggest new paths for injector optimization.

  20. Maximum current density and beam brightness achievable by laser-driven electron sources

    Science.gov (United States)

    Filippetto, D.; Musumeci, P.; Zolotorev, M.; Stupakov, G.

    2014-02-01

    This paper discusses the extension to different electron beam aspect ratio of the Child-Langmuir law for the maximum achievable current density in electron guns. Using a simple model, we derive quantitative formulas in good agreement with simulation codes. The new scaling laws for the peak current density of temporally long and transversely narrow initial beam distributions can be used to estimate the maximum beam brightness and suggest new paths for injector optimization.

  1. Bright sneezes and dark coughs, loud sunlight and soft moonlight.

    Science.gov (United States)

    Marks, L E

    1982-04-01

    Synesthetic metaphors (such as "the dawn comes up like thunder") are expressions in which words or phrases describing experiences proper to one sense modality transfer their meanings to another modality. In a series of four experiments, subjects used scales of loudness, pitch, and brightness to evaluate the meanings of a variety of synesthetic (auditory-visual) metaphors. Loudness and pitch expressed themselves metaphorically as greater brightness; in turn, brightness expressed itself as greater loudness and as higher pitch. Although loudness thus shared with brightness a metaphorical connection, pitch and brightness showed a connection that was closer and that applied more generally to different kinds of visual brightness. The ways that people evaluate synesthetic metaphors emulate the characteristics of synesthetic perception, thereby suggesting that synesthesia in perception and synesthesia in language both may emenate from the same source-from a phenomenological similarity in the makeup of sensory experiences of different modalities.

  2. Bright photoluminescent hybrid mesostructured silica nanoparticles.

    Science.gov (United States)

    Miletto, Ivana; Bottinelli, Emanuela; Caputo, Giuseppe; Coluccia, Salvatore; Gianotti, Enrica

    2012-07-28

    Bright photoluminescent mesostructured silica nanoparticles were synthesized by the incorporation of fluorescent cyanine dyes into the channels of MCM-41 mesoporous silica. Cyanine molecules were introduced into MCM-41 nanoparticles by physical adsorption and covalent grafting. Several photoluminescent nanoparticles with different organic loadings have been synthesized and characterized by X-ray powder diffraction, high resolution transmission electron microscopy and nitrogen physisorption porosimetry. A detailed photoluminescence study with the analysis of fluorescence lifetimes was carried out to elucidate the cyanine molecules distribution within the pores of MCM-41 nanoparticles and the influence of the encapsulation on the photoemission properties of the guests. The results show that highly stable photoluminescent hybrid materials with interesting potential applications as photoluminescent probes for diagnostics and imaging can be prepared by both methods.

  3. Bioinspired bright noniridescent photonic melanin supraballs.

    Science.gov (United States)

    Xiao, Ming; Hu, Ziying; Wang, Zhao; Li, Yiwen; Tormo, Alejandro Diaz; Le Thomas, Nicolas; Wang, Boxiang; Gianneschi, Nathan C; Shawkey, Matthew D; Dhinojwala, Ali

    2017-09-01

    Structural colors enable the creation of a spectrum of nonfading colors without pigments, potentially replacing toxic metal oxides and conjugated organic pigments. However, significant challenges remain to achieve the contrast needed for a complete gamut of colors and a scalable process for industrial application. We demonstrate a feasible solution for producing structural colors inspired by bird feathers. We have designed core-shell nanoparticles using high-refractive index (RI) (~1.74) melanin cores and low-RI (~1.45) silica shells. The design of these nanoparticles was guided by finite-difference time-domain simulations. These nanoparticles were self-assembled using a one-pot reverse emulsion process, which resulted in bright and noniridescent supraballs. With the combination of only two ingredients, synthetic melanin and silica, we can generate a full spectrum of colors. These supraballs could be directly added to paints, plastics, and coatings and also used as ultraviolet-resistant inks or cosmetics.

  4. Tipping Point

    Medline Plus

    Full Text Available ... en español Blog About OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by ... danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe ...

  5. Kappa-effect and brightness oscillations of stars

    Science.gov (United States)

    Zhugzhda, Y. D.; Roth, M.; Herzberg, W.

    2012-12-01

    In this paper the theory of visibility and darkening functions for the brightness oscillations of stars is outlined. For this the non-grey approximation is used and the effect of opacity disturbances on stellar brightness oscillations is explored for different types of stars. An explanation of the Procyon paradox is proposed. Special features of the brightness oscillations are discussed. The effect of opacity fluctuations on the damping of p-mode oscillations is considered. Furthermore, the photospheric kappa-mechanism is discussed.

  6. Study of Three-Dimensional Image Brightness Loss in Stereoscopy

    Directory of Open Access Journals (Sweden)

    Hsing-Cheng Yu

    2015-10-01

    Full Text Available When viewing three-dimensional (3D images, whether in cinemas or on stereoscopic televisions, viewers experience the same problem of image brightness loss. This study aims to investigate image brightness loss in 3D displays, with the primary aim being to quantify the image brightness degradation in the 3D mode. A further aim is to determine the image brightness relationship to the corresponding two-dimensional (2D images in order to adjust the 3D-image brightness values. In addition, the photographic principle is used in this study to measure metering values by capturing 2D and 3D images on television screens. By analyzing these images with statistical product and service solutions (SPSS software, the image brightness values can be estimated using the statistical regression model, which can also indicate the impact of various environmental factors or hardware on the image brightness. In analysis of the experimental results, comparison of the image brightness between 2D and 3D images indicates 60.8% degradation in the 3D image brightness amplitude. The experimental values, from 52.4% to 69.2%, are within the 95% confidence interval

  7. The night sky brightness at McDonald Observatory

    Science.gov (United States)

    Kalinowski, J. K.; Roosen, R. G.; Brandt, J. C.

    1975-01-01

    Baseline observations of the night sky brightness in B and V are presented for McDonald Observatory. In agreement with earlier work by Elvey and Rudnick (1937) and Elvey (1943), significant night-to-night and same-night variations in sky brightness are found. Possible causes for these variations are discussed. The largest variation in sky brightness found during a single night is approximately a factor of two, a value which corresponds to a factor-of-four variation in airglow brightness. The data are used to comment on the accuracy of previously published surface photometry of M 81.

  8. The Spectrophotometric Multicomponent Analysis of a Ternary Mixture of Ibuprofen, Caffeine and Paracetamol by the Combination of Double Divisor-Ratio Spectra Derivative and H-Point Standard Addition Method

    Directory of Open Access Journals (Sweden)

    R. Hajian

    2012-01-01

    Full Text Available A new spectrophotometric method was developed for the simultaneous analysis of a ternary mixture containing paracetamol (PAR, ibuprofen (IBU and caffeine (CAF without prior separation. H-point standard addition method (HPSAM was used for the first time in the analysis of a component (IBU in a ternary mixture (paracetamol, ibuprofen and caffeine. In contrast, PAR and CAF determined using double divisor ratio spectra derivative method. This method is based on the use of derivative of the ratio spectrum obtained by dividing the absorption spectrum of the ternary mixture by a standard spectrum of a mixture of two of the three compounds in the title mixture. The concentrations of PAR and CAF compounds in their mixture are determined by using their respective standard addition graphs which are obtained by measuring the amplitude at either the maximum or minimum wavelengths selected. The mathematical explanation of the procedure is illustrated. It was shown that at wavelengths 226 and 260 nm, the coordinate of H-point is only dependent on the concentration of IBU without any interference by PAR and CAF. This method was successfully applied for the analysis of Novafen capsule, with no interference from excipients as indicated by the recovery study results. The proposed method is simple and rapid and can be easily used in the quality control of drugs as an alternative analysis tools.

  9. Automatic detection and extraction of ultra-fine bright structure observed with new vacuum solar telescope

    Science.gov (United States)

    Deng, Linhua

    2017-02-01

    Solar magnetic structures exhibit a wealth of different spatial and temporal scales. Presently, solar magnetic element is believed to be the ultra-fine magnetic structure in the lower solar atmospheric layer, and the diffraction limit of the largest-aperture solar telescope (New Vacuum Solar Telescope; NVST) of China is close to the spatial scale of magnetic element. This implies that modern solar observations have entered the era of high resolution better than 0.2 arc-second. Since the year of 2011, the NVST have successfully established and obtained huge observational data. Moreover, the ultra-fine magnetic structure rooted in the dark inter-graunlar lanes can be easily resolved. Studies on the observational characteristics and physical mechanism of magnetic bright points is one of the most important aspects in the field of solar physics, so it is very important to determine the statistical and physical parameters of magnetic bright points with the feature extraction techniques and numerical analysis approaches. For identifying such ultra-fine magnetic structure, an automatically and effectively detection algorithm, employed the Laplacian transform and the morphological dilation technique, is proposed and examined. Then, the statistical parameters such as the typical diameter, the area distribution, the eccentricity, and the intensity contrast are obtained. And finally, the scientific meaning for investigating the physical parameters of magnetic bright points are discussed, especially for understanding the physical processes of solar magnetic energy transferred from the photosphere to the corona.

  10. Direct imaging of phase objects enables conventional deconvolution in bright field light microscopy.

    Science.gov (United States)

    Hernández Candia, Carmen Noemí; Gutiérrez-Medina, Braulio

    2014-01-01

    In transmitted optical microscopy, absorption structure and phase structure of the specimen determine the three-dimensional intensity distribution of the image. The elementary impulse responses of the bright field microscope therefore consist of separate absorptive and phase components, precluding general application of linear, conventional deconvolution processing methods to improve image contrast and resolution. However, conventional deconvolution can be applied in the case of pure phase (or pure absorptive) objects if the corresponding phase (or absorptive) impulse responses of the microscope are known. In this work, we present direct measurements of the phase point- and line-spread functions of a high-aperture microscope operating in transmitted bright field. Polystyrene nanoparticles and microtubules (biological polymer filaments) serve as the pure phase point and line objects, respectively, that are imaged with high contrast and low noise using standard microscopy plus digital image processing. Our experimental results agree with a proposed model for the response functions, and confirm previous theoretical predictions. Finally, we use the measured phase point-spread function to apply conventional deconvolution on the bright field images of living, unstained bacteria, resulting in improved definition of cell boundaries and sub-cellular features. These developments demonstrate practical application of standard restoration methods to improve imaging of phase objects such as cells in transmitted light microscopy.

  11. Direct imaging of phase objects enables conventional deconvolution in bright field light microscopy.

    Directory of Open Access Journals (Sweden)

    Carmen Noemí Hernández Candia

    Full Text Available In transmitted optical microscopy, absorption structure and phase structure of the specimen determine the three-dimensional intensity distribution of the image. The elementary impulse responses of the bright field microscope therefore consist of separate absorptive and phase components, precluding general application of linear, conventional deconvolution processing methods to improve image contrast and resolution. However, conventional deconvolution can be applied in the case of pure phase (or pure absorptive objects if the corresponding phase (or absorptive impulse responses of the microscope are known. In this work, we present direct measurements of the phase point- and line-spread functions of a high-aperture microscope operating in transmitted bright field. Polystyrene nanoparticles and microtubules (biological polymer filaments serve as the pure phase point and line objects, respectively, that are imaged with high contrast and low noise using standard microscopy plus digital image processing. Our experimental results agree with a proposed model for the response functions, and confirm previous theoretical predictions. Finally, we use the measured phase point-spread function to apply conventional deconvolution on the bright field images of living, unstained bacteria, resulting in improved definition of cell boundaries and sub-cellular features. These developments demonstrate practical application of standard restoration methods to improve imaging of phase objects such as cells in transmitted light microscopy.

  12. Extended Bright Bodies - Flight and Ground Software Challenges on the Cassini Mission at Saturn

    Science.gov (United States)

    Sung, Tina S.; Burk, Thomas A.

    2016-01-01

    Extended bright bodies in the Saturn environment such as Saturn's rings, the planet itself, and Saturn's satellites near the Cassini spacecraft may interfere with the star tracker's ability to find stars. These interferences can create faulty spacecraft attitude knowledge, which would decrease the pointing accuracy or even trip a fault protection response on board the spacecraft. The effects of the extended bright body interference were observed in December of 2000 when Cassini flew by Jupiter. Based on this flight experience and expected star tracker behavior at Saturn, the Cassini AACS operations team defined flight rules to suspend the star tracker during predicted interference windows. The flight rules are also implemented in the existing ground software called Kinematic Predictor Tool to create star identification suspend commands to be uplinked to the spacecraft for future predicted interferences. This paper discusses the details of how extended bright bodies impact Cassini's acquisition of attitude knowledge, how the observed data helped the ground engineers in developing flight rules, and how automated methods are used in the flight and ground software to ensure the spacecraft is continuously operated within these flight rules. This paper also discusses how these established procedures will continue to be used to overcome new bright body challenges that Cassini will encounter during its dips inside the rings of Saturn for its final orbits of a remarkable 20-year mission at Saturn.

  13. Extinction in the Galaxy from Surface Brightnesses of ESO-LV Galaxies : Determination of A_R/A_B ratio

    NARCIS (Netherlands)

    Choloniewski, J.; Valentijn, E. A.

    A new method for the determination of the extinction in the Galaxy is proposed. The method uses surface brightnesses of external galaxies in the B and R-bands. The observational data have been taken from the ESO-LV galaxy catalog. As a first application of our model we derive the ratio of R-band to

  14. A very high-resolution (1 km×1 km global fossil fuel CO2 emission inventory derived using a point source database and satellite observations of nighttime lights

    Directory of Open Access Journals (Sweden)

    S. Maksyutov

    2011-01-01

    Full Text Available Emissions of CO2 from fossil fuel combustion are a critical quantity that must be accurately given in established flux inversion frameworks. Work with emerging satellite-based inversions requires spatiotemporally-detailed inventories that permit analysis of regional natural sources and sinks. Conventional approaches for disaggregating national emissions beyond the country and city levels based on population distribution have certain difficulties in their application. We developed a global 1 km×1 km annual fossil fuel CO2 emission inventory for the years 1980–2007 by combining a worldwide point source database and satellite observations of the global nightlight distribution. In addition to estimating the national emissions using global energy consumption statistics, emissions from point sources were estimated separately and were spatially allocated to exact locations indicated by the point source database. Emissions from other sources were distributed using a special nightlight dataset that had fewer saturated pixels compared with regular nightlight datasets. The resulting spatial distributions differed in several ways from those derived using conventional population-based approaches. Because of the inherent characteristics of the nightlight distribution, source regions corresponding to human settlements and land transportation were well articulated. Our distributions showed good agreement with a high-resolution inventory across the US at spatial resolutions that were adequate for regional flux inversions. The inventory can be extended to the future using updated data, and is expected to be incorporated into models for operational flux inversions that use observational data from the Japanese Greenhouse Gases Observing SATellite (GOSAT.

  15. A new perspective on the infrared brightness temperature ...

    Indian Academy of Sciences (India)

    And Johnson SB parameters are observed to be best in discriminating the Johnson SB distribution of infrared brightness temperatures of deep convective systems for each season. Due to these properties of Johnson SB function, it can be utilized in the modelling of the histogram of infrared brightness temperature of deep ...

  16. A new perspective on the infrared brightness temperature ...

    Indian Academy of Sciences (India)

    It is observed that Johnson SB function is the best continuous distribution function in explaining the histogram of infrared brightness temperatures of the convective clouds. The best fit is confirmed by Kolmogorov–Smirnov statistic. Johnson SB's distribution of histogram of infrared brightness temperatures clearly ...

  17. Analysis of Bright Harvest Remote Analysis for Residential Solar Installations

    Energy Technology Data Exchange (ETDEWEB)

    Nangle, John [National Renewable Energy Lab. (NREL), Golden, CO (United States); Simon, Joseph [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-06-17

    Bright Harvest provides remote shading analysis and design products for residential PV system installers. The National Renewable Energy Laboratory (NREL) through the NREL Commercialization Assistance Program, completed comparative assessments between on-site measurements and remotely calculated values to validate the accuracy of Bright Harvest’s remote shading and power generation.

  18. Edge integration and the perception of brightness and darkness

    NARCIS (Netherlands)

    Vladusich, T.; Lucassen, M.P.; Cornelissen, F.W.

    2006-01-01

    How do induced brightness and darkness signals from local and remote surfaces interact to determine the final achromatic color percept of a target surface? An emerging theory of achromatic color perception posits that brightness and darkness percepts are computed by weighting and summing the

  19. The ASAS-SN bright supernova catalogue - III. 2016

    DEFF Research Database (Denmark)

    Holoien, T. W. -S.; Brown, J. S.; Stanek, K. Z.

    2017-01-01

    This catalogue summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright (m(peak)d......This catalogue summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright (m(peak)d...

  20. Lamp spectrum and spatial brightness at photopic levels

    DEFF Research Database (Denmark)

    Fotios, Steve; Atli, Deniz; Cheal, Chris

    2015-01-01

    Light sources are available in a variety of spectral power distributions (SPDs) and this affects spatial brightness in a manner not predicted by quantities such as illuminance. Tuning light source SPD to better match the sensitivity of visual perception may allow the same spatial brightness...

  1. Brightness limitations of cold field emitters caused by Coulomb interactions

    NARCIS (Netherlands)

    Cook, B.J.; Verduin, T.; Hagen, C.W.; Kruit, P.

    2010-01-01

    Emission theory predicts that high brightness cold field emitters can enhance imaging in the electron microscope. This (neglecting chromatic aberration) is because of the large (coherent) probe current available from a high brightness source and is based on theoretically determined values of reduced

  2. Surface photometry of bulge dominated low surface brightness galaxies

    NARCIS (Netherlands)

    Beijersbergen, M; de Blok, WJG; van der Hulst, JM

    1999-01-01

    We present results of broad band BVRI observations of a sample of galaxies with a low surface brightness (LSB) disk and a bulge. These galaxies are well described as exponential disks and exponential bulges with no preferred value for either scale length or central surface brightness. The median B

  3. Spatial Model of Sky Brightness Magnitude in Langkawi Island, Malaysia

    Science.gov (United States)

    Redzuan Tahar, Mohammad; Kamarudin, Farahana; Umar, Roslan; Khairul Amri Kamarudin, Mohd; Sabri, Nor Hazmin; Ahmad, Karzaman; Rahim, Sobri Abdul; Sharul Aikal Baharim, Mohd

    2017-03-01

    Sky brightness is an essential topic in the field of astronomy, especially for optical astronomical observations that need very clear and dark sky conditions. This study presents the spatial model of sky brightness magnitude in Langkawi Island, Malaysia. Two types of Sky Quality Meter (SQM) manufactured by Unihedron are used to measure the sky brightness on a moonless night (or when the Moon is below the horizon), when the sky is cloudless and the locations are at least 100 m from the nearest light source. The selected locations are marked by their GPS coordinates. The sky brightness data obtained in this study were interpolated and analyzed using a Geographic Information System (GIS), thus producing a spatial model of sky brightness that clearly shows the dark and bright sky areas in Langkawi Island. Surprisingly, our results show the existence of a few dark sites nearby areas of high human activity. The sky brightness of 21.45 mag arcsec{}-2 in the Johnson-Cousins V-band, as the average of sky brightness equivalent to 2.8 × {10}-4{cd} {{{m}}}-2 over the entire island, is an indication that the island is, overall, still relatively dark. However, the amount of development taking place might reduce the number in the near future as the island is famous as a holiday destination.

  4. A daytime measurement of the lunar contribution to the night sky brightness in LSST's ugrizy bands-initial results

    Science.gov (United States)

    Coughlin, Michael; Stubbs, Christopher; Claver, Chuck

    2016-06-01

    We report measurements from which we determine the spatial structure of the lunar contribution to night sky brightness, taken at the LSST site on Cerro Pachon in Chile. We use an array of six photodiodes with filters that approximate the Large Synoptic Survey Telescope's u, g, r, i, z, and y bands. We use the sun as a proxy for the moon, and measure sky brightness as a function of zenith angle of the point on sky, zenith angle of the sun, and angular distance between the sun and the point on sky. We make a correction for the difference between the illumination spectrum of the sun and the moon. Since scattered sunlight totally dominates the daytime sky brightness, this technique allows us to cleanly determine the contribution to the (cloudless) night sky from backscattered moonlight, without contamination from other sources of night sky brightness. We estimate our uncertainty in the relative lunar night sky brightness vs. zenith and lunar angle to be between 0.3-0.7 mags depending on the passband. This information is useful in planning the optimal execution of the LSST survey, and perhaps for other astronomical observations as well. Although our primary objective is to map out the angular structure and spectrum of the scattered light from the atmosphere and particulates, we also make an estimate of the expected number of scattered lunar photons per pixel per second in LSST, and find values that are in overall agreement with previous estimates.

  5. Fixed Points

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 5. Fixed Points - From Russia with Love - A Primer of Fixed Point Theory. A K Vijaykumar. Book Review Volume 5 Issue 5 May 2000 pp 101-102. Fulltext. Click here to view fulltext PDF. Permanent link:

  6. Tipping Point

    Medline Plus

    Full Text Available ... OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point ... 24 hours a day. For young children whose home is a playground, it’s the best way to ...

  7. An isolated, bright cusp aurora at Saturn

    Science.gov (United States)

    Kinrade, J.; Badman, S. V.; Bunce, E. J.; Tao, C.; Provan, G.; Cowley, S. W. H.; Grocott, A.; Gray, R. L.; Grodent, D.; Kimura, T.; Nichols, J. D.; Arridge, C. S.; Radioti, A.; Clarke, J. T.; Crary, F. J.; Pryor, W. R.; Melin, H.; Baines, K. H.; Dougherty, M. K.

    2017-06-01

    Saturn's dayside aurora displays a number of morphological features poleward of the main emission region. We present an unusual morphology captured by the Hubble Space Telescope on 14 June 2014 (day 165), where for 2 h, Saturn's FUV aurora faded almost entirely, with the exception of a distinct emission spot at high latitude. The spot remained fixed in local time between 10 and 15 LT and moved poleward to a minimum colatitude of 4°. It was bright and persistent, displaying intensities of up to 49 kR over a lifetime of 2 h. Interestingly, the spot constituted the entirety of the northern auroral emission, with no emissions present at any other local time—including Saturn's characteristic dawn arc, the complete absence of which is rarely observed. Solar wind parameters from propagation models, together with a Cassini magnetopause crossing and solar wind encounter, indicate that Saturn's magnetosphere was likely to have been embedded in a rarefaction region, resulting in an expanded magnetosphere configuration during the interval. We infer that the spot was sustained by reconnection either poleward of the cusp or at low latitudes under a strong component of interplanetary magnetic field transverse to the solar wind flow. The subsequent poleward motion could then arise from either reconfiguration of successive open field lines across the polar cap or convection of newly opened field lines. We also consider the possible modulation of the feature by planetary period rotating current systems.

  8. Intercomparisons of Nine Sky Brightness Detectors

    Directory of Open Access Journals (Sweden)

    Henk Spoelstra

    2011-10-01

    Full Text Available Nine Sky Quality Meters (SQMs have been intercompared during a night time measurement campaign held in the Netherlands in April 2011. Since then the nine SQMs have been distributed across the Netherlands and form the Dutch network for monitoring night sky brightness. The goal of the intercomparison was to infer mutual calibration factors and obtain insight into the variability of the SQMs under different meteorological situations. An ensemble average is built from the individual measurements and used as a reference to infer the mutual calibration factors. Data required additional synchronization prior to the calibration determination, because the effect of moving clouds combined with small misalignments emerges as time jitter in the measurements. Initial scatter of the individual instruments lies between ±14%. Individual night time sums range from −16% to +20%. Intercalibration reduces this to 0.5%, and −7% to +9%, respectively. During the campaign the smallest luminance measured was 0.657 ± 0.003 mcd/m2 on 12 April, and the largest value was 5.94 ± 0.03 mcd/m2 on 2 April. During both occurrences interfering circumstances like snow cover or moonlight were absent.

  9. The Los Alamos high-brightness photoinjector

    Energy Technology Data Exchange (ETDEWEB)

    O' Shea, P.G.

    1991-01-01

    For a number of years Los Alamos National Laboratory has been developing photocathode RF guns for high-brightness electron beam applications such as free-electron lasers (FELs). Previously thermionic high-voltage guns have been the source of choice for the electron accelerators used to drive FELs. The performance of such FELs is severely limited by the emittance growth produced by the subharmonic bunching process and also by the low peak current of the source. In a photoinjector, a laser driven photocathode is placed directly in a high-gradient RF accelerating cavity. A photocathode allows unsurpassed control over the current, and the spatial and temporal profile of the beam. In addition the electrodeless emission'' avoids many of the difficulties associated with multi-electrode guns, i.e. the electrons are accelerated very rapidly to relativistic energies, and there are no electrodes to distort the accelerating fields. For the past two years we have been integrating a photocathode into our existing FEL facility by replacing our thermionic gun and subharmonic bunchers with a high-gradient 1.3 GHz photoinjector. The photoinjector, which is approximately 0.6 m in length, produces 6 MeV, 300 A, 15 ps linac, and accelerated to a final energy of 40 MeV. We have recently begun lasing at wavelengths near 3 {mu}m. 16 refs., 2 figs., 5 tabs.

  10. Dark Skies, Bright Kids Year 6

    Science.gov (United States)

    Liss, Sandra; Troup, Nicholas William; Johnson, Kelsey E.; Barcos-Munoz, Loreto D.; Beaton, Rachael; Bittle, Lauren; Borish, Henry J.; Burkhardt, Andrew; Corby, Joanna; Dean, Janice; Hancock, Danielle; King, Jennie; Prager, Brian; Romero, Charles; Sokal, Kimberly R.; Stierwalt, Sabrina; Wenger, Trey; Zucker, Catherine

    2015-01-01

    Now entering our sixth year of operation, Dark Skies, Bright Kids (DSBK) is an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in central Virginia through fun, hands-on activities that introduce basic Astronomy concepts beyond Virginia's Standards of Learning. Our primary focus is hosting an 8-10 week after-school astronomy club at underserved elementary and middle schools. Each week, DSBK volunteers take the role of coaches to introduce astronomy-related concepts ranging from the Solar System to galaxies to astrobiology, and to lead students in interactive learning activities. Another hallmark of DSBK is hosting our Annual Central Virginia Star Party, a free event open to the community featuring star-gazing and planetarium shows.DSBK has amassed over 15,000 contact hours since 2009 and we continue to broaden our impact. One important step we have taken in the past year is to establish a graduate student led assessment program to identify and implement directed learning goals for DSBK outreach. The collection of student workbooks, observations, and volunteer surveys indicates broad scale success for the program both in terms of student learning and their perception of science. The data also reveal opportunities to improve our organizational and educational practices to maximize student achievement and overall volunteer satisfaction for DSBK's future clubs and outreach endeavors.

  11. Dark Skies, Bright Kids Year 9

    Science.gov (United States)

    Burkhardt, Andrew Michael; Mathews, Allison M.; Johnson, Kelsey E.; Avilez, Ian; Beale, Luca; Bittle, Lauren E.; Bordenave, David; Finn, Molly; Firebaugh, Ariel; Hancock, Danielle; Hughes, Paul; Rochford Hayes, Christian; Lewis, Hannah; Linden, Sean; Liss, Sandra; Liu, Mengyao; McNair, Shunlante; Murphy, Edward; Prager, Brian; Pryal, Matthew; Richardson, Whitney; Song, Yiqing; Troup, Nicholas; Villadsen, Jackie; Wenger, Trey V.; Wilson, Robert Forrest

    2018-01-01

    We present updates from the ninth year of operation of Dark Skies, Bright Kids (DSBK) including new club content, continued assessments, and our seventh annual Star Party. DSBK is an entirely volunteer-run outreach organization based out of the Department of Astronomy at the University of Virginia. Our core mission is to enhance elementary science education and literacy in Virginia through fun, hands-on activities that introduce basic Astronomy concepts. DSBK’s most fundamental program is an 8-10 week long after-school Astronomy camp at surrounding local elementary schools, where each week introduces new concepts through interactive hands-on activities. Over the past two summers, we have traveled to four rural Virginia locations to bring week-long Astronomy camps to otherwise overlooked elementary school districts. These programs aim to inspire a curiosity for science and include inquiry based activities in topics ranging from the electromagnetic spectrum to the classification and evolution of galaxies. We strive to be self-reflective in our mission to inspire scientific curiosity in the minds of underserved demographics. In this effort, we continually assess the effectiveness of each activity through feedback in student-kept journal pages and observed excitement levels. This self-reflection has initiated the development of new curriculum. In addition, differing from our normal collaboration with local elementary schools, we have found great success partnering with local youth organizations, who may better represent DSBK's target demographics and have infrastructure to support incoming outreach groups.

  12. Bright visible light emission from graphene.

    Science.gov (United States)

    Kim, Young Duck; Kim, Hakseong; Cho, Yujin; Ryoo, Ji Hoon; Park, Cheol-Hwan; Kim, Pilkwang; Kim, Yong Seung; Lee, Sunwoo; Li, Yilei; Park, Seung-Nam; Yoo, Yong Shim; Yoon, Duhee; Dorgan, Vincent E; Pop, Eric; Heinz, Tony F; Hone, James; Chun, Seung-Hyun; Cheong, Hyeonsik; Lee, Sang Wook; Bae, Myung-Ho; Park, Yun Daniel

    2015-08-01

    Graphene and related two-dimensional materials are promising candidates for atomically thin, flexible and transparent optoelectronics. In particular, the strong light-matter interaction in graphene has allowed for the development of state-of-the-art photodetectors, optical modulators and plasmonic devices. In addition, electrically biased graphene on SiO2 substrates can be used as a low-efficiency emitter in the mid-infrared range. However, emission in the visible range has remained elusive. Here, we report the observation of bright visible light emission from electrically biased suspended graphene devices. In these devices, heat transport is greatly reduced. Hot electrons (∼2,800 K) therefore become spatially localized at the centre of the graphene layer, resulting in a 1,000-fold enhancement in thermal radiation efficiency. Moreover, strong optical interference between the suspended graphene and substrate can be used to tune the emission spectrum. We also demonstrate the scalability of this technique by realizing arrays of chemical-vapour-deposited graphene light emitters. These results pave the way towards the realization of commercially viable large-scale, atomically thin, flexible and transparent light emitters and displays with low operation voltage and graphene-based on-chip ultrafast optical communications.

  13. Modular Zero Energy. BrightBuilt Home

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, Robb [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States). Steven Winters Associates, Inc.; Butterfield, Karla [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States). Steven Winters Associates, Inc.

    2016-03-01

    Kaplan Thompson Architects (KTA) has specialized in sustainable, energy-efficient buildings, and they have designed several custom, zero-energy homes in New England. These zero-energy projects have generally been high-end, custom homes with budgets that could accommodate advanced energy systems. In an attempt to make zero energy homes more affordable and accessible to a larger demographic, KTA explored modular construction as way to provide high-quality homes at lower costs. In the mid-2013, KTA formalized this concept when they launched BrightBuilt Home (BBH). The BBH mission is to offer a line of architect-designed, high-performance homes that are priced to offer substantial savings off the lifetime cost of a typical home and can be delivered in less time. For the past two years, CARB has worked with BBH and Keiser Homes (the primary modular manufacturer for BBH) to discuss challenges related to wall systems, HVAC, and quality control. In Spring of 2014, CARB and BBH began looking in detail on a home to be built in Lincolnville, ME by Black Bros. Builders. This report details the solution package specified for this modular plan and the challenges that arose during the project.

  14. Intrinsic brightness temperatures of blazar jets at 15 GHz

    Directory of Open Access Journals (Sweden)

    Hovatta Talvikki

    2013-12-01

    Full Text Available We have developed a new Bayesian Markov Chain Monte Carlo method to deconvolve light curves of blazars into individual flares, including proper estimation of the fit errors. We use the method to fit 15GHzlight curves obtained within the OVRO 40-m blazar monitoring program where a large number of AGN have been monitored since 2008 in support of the Fermi Gamma-Ray Space Telescope mission. The time scales obtained from the fitted models are used to calculate the variability brightness temperature of the sources. Additionally, we have calculated brightness temperatures of a sample of these objects using Very Long Baseline Array data from the MOJAVE survey. Combining these two data sets enables us to study the intrinsic brightness temperature distribution in these blazars at 15 GHz. Our preliminary results indicate that the mean intrinsic brightness temperature in a sample of 14 sources is near the equipartition brightness temperature of ~ 1011K.

  15. The bright and the dark sides of motor simulation.

    Science.gov (United States)

    Panasiti, Maria Serena; Porciello, Giuseppina; Aglioti, Salvatore Maria

    2017-10-01

    While the acquisition of knowledge about the sensory, emotional, and motor states of others has long been thought to derive from abstract inferential operations, recent theories based on neuroscientific and psychological models emphasize that motor simulation is essential to a variety of complex functions ranging from the monitoring of one's own performance to the understanding of others' actions, and matching self and others' states to optimize social interactions. In this review, we discuss evidence that simulating the actions of others has both bright and dark sides. On the one hand, we show that simulation can aid the anticipation and prediction of errors in the actions of others (e.g., in the case of competitive sports), as well as the establishment of social bonds (e.g., in the case of mimicry). On the other hand, based on findings from our and other research groups, we describe specific circumstances in which simulating the actions of others is detrimental to performance (e.g., when we automatically follow the gaze of a person who is actually trying to deceive us). Finally, we show how the presence of a shared goal between agents (such as in joint actions) maximizes the cost benefit of motor simulation, suggesting that the top-down modulation of this process is vital for adapting in a social environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Calibration of Surface Brightness Fluctuations for WFC3/IR

    Science.gov (United States)

    Blakeslee, John

    2009-07-01

    We aim to characterize galaxy surface brightness fluctuations {SBF}, and calibrate the SBF distance method, in the F110W and F160W filters of the Wide Field Camera 3 IR channel. Because of the very high throughput of F110W and the good match of F160W to the standard H band, we anticipate that both of these filters will be popular choices for galaxy observations with WFC3/IR. The SBF signal is typically an order of magnitude brighter in the near-IR than in the optical, and the characterisitics {sensitivity, FOV, cosmetics} of the WFC3/IR channel will be enormously more efficient for SBF measurements than previously available near-IR cameras. As a result, our proposed SBF calibration will allow accurate distance derivation whenever an early-type or bulge-dominated galaxy is observed out to a distance of 150 Mpc or more {i.e., out to the Hubble flow} in the calibrated passbands. For individual galaxy observations, an accurate distance is useful for establishing absolute luminosities, black hole masses, linear sizes, etc. Eventually, once a large number of galaxies have been observed across the sky with WFC3/IR, this SBF calibration will enable accurate mapping of the total mass density distribution in the local universe using the data available in the HST archive. The proposed observations will have additional important scientific value; in particular, we highlight their usefulness for understanding the nature of multimodal globular cluster color distributions in giant elliptical galaxies.

  17. Photometry of some neglected bright cataclysmic variables and candidates

    Science.gov (United States)

    Bruch, Albert

    2017-04-01

    As part of an effort to better characterize bright cataclysmic variables (CVs) which have received little attention in the past light curves of four confirmed systems (CZ Aql, BO Cet, V380 Oph and EF Tuc) and one candidate (Lib 3) are analyzed. For none of these stars time resolved photometry has been published previously. While no variability was found in the case of Lib 3, which thus cannot be confirmed as a CV, the light curves of all other targets are dominated by strong flickering. Modulations on hourly time scales superimposed on the flickering can probably be related to orbital variations in BO Cet and V380 Oph, but not in CZ Aql and EF Tuc. Variations on the time scale of 10 min in CZ Aql, while not yet constituting convincing evidence, together with previous suspicions of a magnetically channeled accretion flow may point at an intermediate polar nature of this star. Some properties of the flickering are quantified in an effort to enlarge the data base for future comparative flickering studies in CVs and to refine the classification of the target stars.

  18. GMRT H I study of giant low surface brightness galaxies

    Science.gov (United States)

    Mishra, A.; Kantharia, N. G.; Das, M.; Omar, A.; Srivastava, D. C.

    2017-01-01

    We present H I observations of four giant low surface brightness (GLSB) galaxies UGC 1378, UGC 1922, UGC 4422 and UM 163 using the Giant Meterwave Radio Telescope. We include H I results on UGC 2936, UGC 6614 and Malin 2 from literature. H I is detected from all the galaxies and the extent is roughly twice the optical size; in UM 163, H I is detected along a broken disc encircling the optical galaxy. We combine our results with those in literature to further understand these systems. The main results are the following: (1) the peak H I surface densities in GLSB galaxies are several times 1021 cm-2. The H I mass is between 0.3 and 4 × 1010 M⊙; dynamical mass ranges from a few times 1011 M⊙ to a few times 1012 M⊙. (2) The rotation curves of GLSB galaxies are flat to the outermost measured point with rotation velocities of the seven GLSB galaxies being between 225 and 432 km s-1. (3) Recent star formation traced by near-ultraviolet emission in five GLSB galaxies in our sample appears to be located in rings around the galaxy centre. We suggest that this could be due to a stochastic burst of star formation at one location in the galaxy being propagated along a ring over a rotation period. (4) The H I is correlated with recent star formation in five of the seven GLSB galaxies.

  19. Compact bright pulse and ultrashort-pulse in the nonlinear Kerr-like media

    Science.gov (United States)

    Pokam Nguewawe, Chancelor; Yemele, David; Donkeng, Hatou-Yvelin; Kofane, Timoléon Crépin

    2017-02-01

    The extended nonlinear Schrödinger equation describing the propagation of light beam in the weak nonlocal nonlinear media in general, and in the optical fibers with nearly instantaneous nonlinear response of the medium in particular, is investigated. In the zero-dispersion limit, we show that the system exhibits stable stationary compact bright pulse with an arbitrary nonlinear phase-shift both for the focusing and the defocusing media. However, in the presence of the large linear dispersion, this compact pulse become unstable and may be either disintegrate or transform into the ultrashort bright pulse according to whether the system operates in the normal or in the anomalous region. The exact analytical expressions of these two pulses are derived and the results checked through numerical simulations.

  20. A Zn-porphyrin complex contributes to bright red color in Parma ham.

    Science.gov (United States)

    Wakamatsu, J; Nishimura, T; Hattori, A

    2004-05-01

    The Italian traditional dry-cured ham (Parma ham) shows a stable bright red color that is achieved without the use of nitrite and/or nitrate. In this study we examined the pigment spectroscopically, fluoroscopically and by using HPLC and ESI-HR-MASS analysis. Porphyrin derivative other than acid hematin were contained in the HCl-containing acetone extract from Parma ham. A strong fluorescence peak at 588 nm and a weak fluorescence peak at 641 nm were observed. By HPLC analysis the acetone extract of Parma ham was observed at the single peak, which eluted at the same time as Zn-protoporphyrin IX and emitted fluorescence. The results of ESI-HR-MS analysis showed both agreement with the molecular weight of Zn-protoporphyrin IX and the characteristic isotope pattern caused by Zn isotopes. These results suggest that the bright red color in Parma ham is caused by Zn-protoporphyrin IX.

  1. Evaluating a model of global psychophysical judgments for brightness: I. Behavioral properties of summations and productions.

    Science.gov (United States)

    Steingrimsson, Ragnar

    2009-11-01

    Steingrimsson and Luce (2005a, 2005b, 2006, 2007) evaluated Luce's (2002, 2004) proposed psychophysical theory of loudness and found it substantially supported. The aim of the present research is to begin an extension of this research to brightness. Luce's (2002, 2004) theory deals with the global percept of subjective intensity, in which there is a psychophysical function Psi that maps pairs of physical intensities onto positive real numbers and represents, in an explicit mathematical way, subjective summation and a form of ratio production. These representations derive from a number of behavioral properties, including certain plausible background assumptions. In three experiments involving the subjective perception of luminance, brightness, the key behavioral properties of summation over the two eyes, and a form of generalized ratio production are empirically evaluated. Considerable support is reported for particular forms of Psi separately for summations and ratio productions.

  2. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head ... see news reports about horrible accidents involving young children and furniture, appliance and tv tip-overs. The ...

  3. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head ... TV falls with about the same force as child falling from the third story of a building. ...

  4. Dark Skies, Bright Kids: Year 2

    Science.gov (United States)

    Carlberg, Joleen K.; Johnson, K.; Lynch, R.; Walker, L.; Beaton, R.; Corby, J.; de Messieres, G.; Drosback, M.; Gugliucci, N.; Jackson, L.; Kingery, A.; Layman, S.; Murphy, E.; Richardson, W.; Ries, P.; Romero, C.; Sivakoff, G.; Sokal, K.; Trammell, G.; Whelan, D.; Yang, A.; Zasowski, G.

    2011-01-01

    The Dark Skies, Bright Kids (DSBK) outreach program brings astronomy education into local elementary schools in central Virginia's Southern Albemarle County through an after-school club. Taking advantage of the unusually dark night skies in the rural countryside, DSBK targets economically disadvantaged schools that tend to be underserved due to their rural locale. The goals of DSBK are to foster children's natural curiosity, demonstrate that science is a fun and creative process, challenge students' conceptions of what a scientist is and does, and teach some basic astronomy. Furthermore, DSBK works to assimilate families into students' education by holding family observing nights at the school. Now in its third semester, DSBK has successfully run programs at two schools with very diverse student populations. Working with these students has helped us to revise our activities and to create new ones. A by-product of our work has been the development of lesson plans, complete with learning goals and detailed instructions, that we make publically available on our website. This year we are expanding our repertoire with our new planetarium, which allows us to visualize topics in novel ways and supplements family observing on cloudy nights. The DSBK volunteers have also created a bilingual astronomy artbook --- designed, written, and illustrated by UVa students --- that we will publish and distribute to elementary schools in Virginia. Our book debuted at the last AAS winter meeting, and since then it has been extensively revised and updated with input from many individuals, including parents, professional educators, and a children's book author. Because the club is currently limited to serving a few elementary schools, this book will be part of our efforts to broaden our impact by bringing astronomy to schools we cannot go to ourselves and reaching out to Spanish-speaking communities at the same time.

  5. Optical microvariability of bright type 2 quasars

    Science.gov (United States)

    Polednikova, Jana; Ederoclite, Alessandro; Cepa, Jordi; de Diego Onsurbe, José Antonio; González-Serrano, José Ignacio

    2014-07-01

    We present results from a project focused on searching optical microvariabilty (also known as ``intra-night'' variability) in type 2 - obscured - quasars. Optical microvariability can be described as very small changes in the flux, typically in the order of hundredths of magnitude, which can be observed on timescales of hours. Such studies have been so far conducted for samples of blazars and type 1, unobscured, AGNs, where the optical microvariability was detected with success. We have focused on obscured targets which would pose a challenge to the AGN standard model. In the present work, however, we have observed a sample of three bright (g mag < 17) type 2 quasar, based on the catalog of type 2 quasars from SDSS of Reyes et al. (2008). The observations were carried out with the 1.5 meter telescope at San Pedro Martir observatory in Mexico. The sample was observed during an observation period of four days in Johnsons V filter, resulting in at least two continuous intervals of observations per target during the observational run. We have obtained differential light curves for our sources as well as for the comparison stars. They were analyzed using one-way analysis of variance statistical test (ANOVA), which has been repeatedly used in the past for studies of unobscured targets. Based on the results from the statistical analysis, we show that at least two out of three observed targets appear to be variable on time scales of hours. So far, this is the first study which confirmed existence of optical microvariability in type 2 quasars.

  6. Optical sky brightness at Dome A, Antarctica, from the Nigel experiment

    Science.gov (United States)

    Sims, Geoff; Ashley, Michael C. B.; Cui, Xiangqun; Everett, Jon R.; Feng, Longlong; Gong, Xuefei; Hengst, Shane; Hu, Zhongwen; Lawrence, Jon S.; Luong-van, Daniel M.; Shang, Zhaohui; Storey, John W. V.; Wang, Lifan; Yang, Huigen; Yang, Ji; Zhou, Xu; Zhu, Zhengxi

    2010-07-01

    Nigel is a fiber-fed UV/visible grating spectrograph with a thermoelectrically-cooled 256×1024 pixel CCD camera, designed to measure the twilight and night sky brightness from 300nm to 850 nm. Nigel has three pairs of fibers, each with a field-of-view with an angular diameter of 25 degrees, pointing in three fixed positions towards the sky. The bare fibers are exposed to the sky with no additional optics. The instrument was deployed at Dome A, Antarctica in January 2009 as part of the PLATO (PLATeau Observatory) robotic observatory. During the 2009 winter, Nigel made approximately six months of continuous observations of the sky, with typically 104 deadtime between exposures. The resulting spectra provide quantitative information on the sky brightness, the auroral contribution, and the water vapour content of the atmosphere. We present details of the design, construction and calibration of the Nigel spectrometer, as well some sample spectra from a preliminary analysis.

  7. The Spectral Energy Distribution of Fermi Bright Blazars

    Science.gov (United States)

    Abdo, A. A.; Ackermann, M.; Agudo, I.; Ajello, M.; Aller, H. D.; Aller, M. F.; Angelakis, E.; Arkharov, A. A.; Axelsson, M.; Bach, U.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B. M.; Bechtol, K.; Bellazzini, R.; Benitez, E.; Berdyugin, A.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Boettcher, M.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brez, A.; Brigida, M.; Bruel, P.; Burnett, T. H.; Burrows, D.; Buson, S.; Caliandro, G. A.; Calzoletti, L.; Cameron, R. A.; Capalbi, M.; Caraveo, P. A.; Carosati, D.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chaty, S.; Chekhtman, A.; Chen, W. P.; Chiang, J.; Chincarini, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Colafrancesco, S.; Cominsky, L. R.; Conrad, J.; Costamante, L.; Cutini, S.; D'ammando, F.; Deitrick, R.; D'Elia, V.; Dermer, C. D.; de Angelis, A.; de Palma, F.; Digel, S. W.; Donnarumma, I.; Silva, E. do Couto e.; Drell, P. S.; Dubois, R.; Dultzin, D.; Dumora, D.; Falcone, A.; Farnier, C.; Favuzzi, C.; Fegan, S. J.; Focke, W. B.; Forné, E.; Fortin, P.; Frailis, M.; Fuhrmann, L.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gómez, J. L.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giuliani, A.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Gronwall, C.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Gurwell, M. A.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Healey, S. E.; Heidt, J.; Hiriart, D.; Horan, D.; Hoversten, E. A.; Hughes, R. E.; Itoh, R.; Jackson, M. S.; Jóhannesson, G.; Johnson, A. S.; Johnson, W. N.; Jorstad, S. G.; Kadler, M.; Kamae, T.; Katagiri, H.; Kataoka, J.; Kawai, N.; Kennea, J.; Kerr, M.; Kimeridze, G.; Knödlseder, J.; Kocian, M. L.; Kopatskaya, E. N.; Koptelova, E.; Konstantinova, T. S.; Kovalev, Y. Y.; Kovalev, Yu. A.; Kurtanidze, O. M.; Kuss, M.; Lande, J.; Larionov, V. M.; Latronico, L.; Leto, P.; Lindfors, E.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Makeev, A.; Marchegiani, P.; Marscher, A. P.; Marshall, F.; Max-Moerbeck, W.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; Meurer, C.; Michelson, P. F.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nestoras, I.; Nilsson, K.; Nizhelsky, N. A.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohsugi, T.; Ojha, R.; Omodei, N.; Orlando, E.; Ormes, J. F.; Osborne, J.; Ozaki, M.; Pacciani, L.; Padovani, P.; Pagani, C.; Page, K.; Paneque, D.; Panetta, J. H.; Parent, D.; Pasanen, M.; Pavlidou, V.; Pelassa, V.; Pepe, M.; Perri, M.; Pesce-Rollins, M.; Piranomonte, S.; Piron, F.; Pittori, C.; Porter, T. A.; Puccetti, S.; Rahoui, F.; Rainò, S.; Raiteri, C.; Rando, R.; Razzano, M.; Reimer, A.; Reimer, O.; Reposeur, T.; Richards, J. L.; Ritz, S.; Rochester, L. S.; Rodriguez, A. Y.; Romani, R. W.; Ros, J. A.; Roth, M.; Roustazadeh, P.; Ryde, F.; Sadrozinski, H. F.-W.; Sadun, A.; Sanchez, D.; Sander, A.; Saz Parkinson, P. M.; Scargle, J. D.; Sellerholm, A.; Sgrò, C.; Shaw, M. S.; Sigua, L. A.; Siskind, E. J.; Smith, D. A.; Smith, P. D.; Spandre, G.; Spinelli, P.; Starck, J.-L.; Stevenson, M.; Stratta, G.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Takalo, L. O.; Tanaka, T.; Thayer, J. B.; Thayer, J. G.; Thompson, D. J.; Tibaldo, L.; Torres, D. F.; Tosti, G.; Tramacere, A.; Uchiyama, Y.; Usher, T. L.; Vasileiou, V.; Verrecchia, F.; Vilchez, N.; Villata, M.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Ylinen, T.; Zensus, J. A.; Zhekanis, G. V.; Ziegler, M.

    2010-06-01

    We have conducted a detailed investigation of the broadband spectral properties of the γ-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated Fermi γ-ray spectra with Swift, radio, infra-red, optical, and other hard X-ray/γ-ray data, collected within 3 months of the LBAS data taking period, we were able to assemble high-quality and quasi-simultaneous spectral energy distributions (SED) for 48 LBAS blazars. The SED of these γ-ray sources is similar to that of blazars discovered at other wavelengths, clearly showing, in the usual log ν-log ν F ν representation, the typical broadband spectral signatures normally attributed to a combination of low-energy synchrotron radiation followed by inverse Compton emission of one or more components. We have used these SED to characterize the peak intensity of both the low- and the high-energy components. The results have been used to derive empirical relationships that estimate the position of the two peaks from the broadband colors (i.e., the radio to optical, αro, and optical to X-ray, αox, spectral slopes) and from the γ-ray spectral index. Our data show that the synchrotron peak frequency (ν S peak) is positioned between 1012.5 and 1014.5 Hz in broad-lined flat spectrum radio quasars (FSRQs) and between 1013 and 1017 Hz in featureless BL Lacertae objects. We find that the γ-ray spectral slope is strongly correlated with the synchrotron peak energy and with the X-ray spectral index, as expected at first order in synchrotron-inverse Compton scenarios. However, simple homogeneous, one-zone, synchrotron self-Compton (SSC) models cannot explain most of our SED, especially in the case of FSRQs and low energy peaked (LBL) BL Lacs. More complex models involving external Compton radiation or multiple SSC components are required to reproduce the overall SED and the observed spectral variability. While more than 50% of known radio bright high energy peaked (HBL) BL Lacs are

  8. GLOBAL PROPERTIES OF M31'S STELLAR HALO FROM THE SPLASH SURVEY. I. SURFACE BRIGHTNESS PROFILE

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, Karoline M. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 (United States); Guhathakurta, Puragra [UCO/Lick Observatory, Department of Astronomy and Astrophysics, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Beaton, Rachael L.; Majewski, Steven R.; Ostheimer, James C.; Patterson, Richard J. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Bullock, James; Tollerud, Erik J. [Center for Cosmology, Department of Physics and Astronomy, University of California at Irvine, Irvine, CA 92697 (United States); Geha, Marla C. [Astronomy Department, Yale University, New Haven, CT 06520 (United States); Kalirai, Jason S. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Kirby, Evan N. [California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States); Tanaka, Mikito; Chiba, Masashi, E-mail: kgilbert@astro.washington.edu [Astronomical Institute, Tohoku University, Aoba-ku, Sendai 980-8578 (Japan)

    2012-11-20

    We present the surface brightness profile of M31's stellar halo out to a projected radius of 175 kpc. The surface brightness estimates are based on confirmed samples of M31 red giant branch stars derived from Keck/DEIMOS spectroscopic observations. A set of empirical spectroscopic and photometric M31 membership diagnostics is used to identify and reject foreground and background contaminants. This enables us to trace the stellar halo of M31 to larger projected distances and fainter surface brightnesses than previous photometric studies. The surface brightness profile of M31's halo follows a power law with index -2.2 {+-} 0.2 and extends to a projected distance of at least {approx}175 kpc ({approx}2/3 of M31's virial radius), with no evidence of a downward break at large radii. The best-fit elliptical isophotes have b/a = 0.94 with the major axis of the halo aligned along the minor axis of M31's disk, consistent with a prolate halo, although the data are also consistent with M31's halo having spherical symmetry. The fact that tidal debris features are kinematically cold is used to identify substructure in the spectroscopic fields out to projected radii of 90 kpc and investigate the effect of this substructure on the surface brightness profile. The scatter in the surface brightness profile is reduced when kinematically identified tidal debris features in M31 are statistically subtracted; the remaining profile indicates that a comparatively diffuse stellar component to M31's stellar halo exists to large distances. Beyond 90 kpc, kinematically cold tidal debris features cannot be identified due to small number statistics; nevertheless, the significant field-to-field variation in surface brightness beyond 90 kpc suggests that the outermost region of M31's halo is also comprised to a significant degree of stars stripped from accreted objects.

  9. High-speed CuBr brightness amplifier beam profile

    Science.gov (United States)

    Evtushenko, G. S.; Torgaev, S. N.; Trigub, M. V.; Shiyanov, D. V.; Evtushenko, T. G.; Kulagin, A. E.

    2017-01-01

    This paper addresses the experimental study of the beam profile of the CuBr brightness amplifier operating at a wide range of pulse repetition frequencies. The use of a medium-size gas discharge tube (2 cm) ensures the operation of the brightness amplifier both at typical PRFs (520 kHz) and at higher PRFs (up to 100 kHz), either with or without HBr additive. The effect of the active additive on the beam profile is demonstrated. The testing results on kinetic modeling of radial processes in the laser (brightness amplifier) plasma are also discussed.

  10. Characterizing the zenithal night sky brightness in large territories: how many samples per square kilometre are needed?

    Science.gov (United States)

    Bará, Salvador

    2018-01-01

    A recurring question arises when trying to characterize, by means of measurements or theoretical calculations, the zenithal night sky brightness throughout a large territory: how many samples per square kilometre are needed? The optimum sampling distance should allow reconstructing, with sufficient accuracy, the continuous zenithal brightness map across the whole region, whilst at the same time avoiding unnecessary and redundant oversampling. This paper attempts to provide some tentative answers to this issue, using two complementary tools: the luminance structure function and the Nyquist-Shannon spatial sampling theorem. The analysis of several regions of the world, based on the data from the New world atlas of artificial night sky brightness, suggests that, as a rule of thumb, about one measurement per square kilometre could be sufficient for determining the zenithal night sky brightness of artificial origin at any point in a region to within ±0.1 magV arcsec-2 (in the root-mean-square sense) of its true value in the Johnson-Cousins V band. The exact reconstruction of the zenithal night sky brightness maps from samples taken at the Nyquist rate seems to be considerably more demanding.

  11. Identifying Bright X-Ray Beasts

    Science.gov (United States)

    Kohler, Susanna

    2017-10-01

    Ultraluminous X-ray sources (ULXs) are astronomical sources of X-rays that, while dimmer than active galactic nuclei, are nonetheless brighter than any known stellar process. What are these beasts and why do they shine so brightly?Exceeding the LimitFirst discovered in the 1980s, ULXs are rare sources that have nonetheless been found in all types of galaxies. Though the bright X-ray radiation seems likely to be coming from compact objects accreting gas, theres a problem with this theory: ULXs outshine the Eddington luminosity for stellar-mass compact objects. This means that a stellar-mass object couldnt emit this much radiation isotropically without blowing itself apart.There are two alternative explanations commonly proposed for ULXs:Rather than being accreting stellar-mass compact objects, they are accreting intermediate-mass black holes. A hypothetical black hole of 100 solar masses or more would have a much higher Eddington luminosity than a stellar-mass black hole, making the luminosities that we observe from ULXs feasible.An example of one of the common routes the authors find for a binary system to become a ULX. In this case, the binary begins as two main sequence stars. As one star evolves off the main sequence, the binary undergoes a common envelope phase and a stage of mass transfer. The star ends its life as a supernova, and the resulting neutron star then accretes matter from the main sequence star as a ULX. [Wiktorowicz et al. 2017]They are ordinary X-ray binaries (a stellar-mass compact object accreting matter from a companion star), but they are undergoing a short phase of extreme accretion. During this time, their emission is beamed into jets, making them appear brighter than the Eddington luminosity.Clues from a New DiscoveryA few years ago, a new discovery shed some light on ULXs: M82 X-2, a pulsing ULX. Two more pulsing ULXs have been discovered since then, demonstrating that at least some ULXs contain pulsars i.e., neutron stars as the

  12. Non-LTE radiating acoustic shocks and Ca II K2V bright points

    Science.gov (United States)

    Carlsson, Mats; Stein, Robert F.

    1992-01-01

    We present, for the first time, a self-consistent solution of the time-dependent 1D equations of non-LTE radiation hydrodynamics in solar chromospheric conditions. The vertical propagation of sinusoidal acoustic waves with periods of 30, 180, and 300 s is calculated. We find that departures from LTE and ionization recombination determine the temperature profiles of the shocks that develop. In LTE almost all the thermal energy goes into ionization, so the temperature rise is very small. In non-LTE, the finite transition rates delay the ionization to behind the shock front. The compression thus goes into thermal energy at the shock front leading to a high temperature amplitude. Further behind the shock front, the delayed ionization removes energy from the thermal pool, which reduces the temperature, producing a temperature spike. The 180 s waves reproduce the observed temporal changes in the calcium K line profiles quite well. The observed wing brightening pattern, the violet/red peak asymmetry and the observed line center behavior are all well reproduced. The short-period waves and the 5 minute period waves fail especially in reproducing the observed behavior of the wings.

  13. The Formation and Disintegration of Magnetic Bright Points Observed by Sunrise/IMaX

    Czech Academy of Sciences Publication Activity Database

    Utz, D.; del Toro Iniesta, J.C.; Bellot Rubio, L.; Jurčák, Jan; Martinez Pillet, V.; Solanki, S.K.; Schmidt, W.

    2014-01-01

    Roč. 796, č. 2 (2014), 79/1-79/17 ISSN 0004-637X R&D Projects: GA MŠk(CZ) MEB061109 Institutional support: RVO:67985815 Keywords : high angular resolution * polarimeters * magnetic fields Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.993, year: 2014

  14. Millimeter-wave Imaging Radiometer Brightness Temperatures, Wakasa Bay, Japan

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes calibrated brightness temperatures measured over Wakasa Bay in the Sea of Japan in January and February 2003. The MIR was carried on a...

  15. Nimbus-5 ESMR Polar Gridded Brightness Temperatures, Version 2

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nimbus-5 Electrically Scanning Microwave Radiometer (ESMR) data set consists of gridded brightness temperature arrays for the Arctic and Antarctic, spanning 11...

  16. SMEX03 SSM/I Brightness Temperature Data, Alabama

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides brightness temperature data acquired during the Soil Moisture Experiment 2003 (SMEX03) by the Special Sensor Microwave/Imager (SSM/I). The...

  17. Binocular Coordination in Reading When Changing Background Brightness

    Directory of Open Access Journals (Sweden)

    Köpsel Anne

    2017-10-01

    Full Text Available Contradicting results concerning binocular coordination in reading have been reported: Liversedge et al. (2006 reported a dominance of uncrossed fixations, whereas Nuthmann and Kliegl (2009 observed more crossed fixations in reading. Based on both earlier and continuing studies, we conducted a reading experiment involving varying brightness of background and font. Calibration was performed using Gabor patches presented on grey background. During the experimental session, text had to be read either on dark, bright, or grey background. The data corroborates former results that showed a predominance of uncrossed fixations when reading on dark background, as well as those showing a predominance of crossed fixations, when reading on bright background. Besides these systematic shifts, the new results show an increase in unsystematic variability when changing the overall brightness from calibration to test. The origins of the effects need to be clarified in future research.

  18. CLPX-Satellite: AVHRR/HRPT Brightness Temperatures and Reflectances

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes AVHRR/HRPT (Advanced Very High Resolution Radiometer/High Resolution Picture Transmission) brightness temperatures and reflectances over the...

  19. SMEX03 SSM/I Brightness Temperature Data, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides brightness temperature data acquired during the Soil Moisture Experiment 2003 (SMEX03) by the Special Sensor Microwave/Imager (SSM/I). The...

  20. Ultra High Brightness/Low Cost Fiber Coupled Packaging Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The focus of the proposed effort is maximizing the brightness of fiber coupled laser diode pump sources at a minimum cost. The specific innovation proposed is to...

  1. DMSP SSM/I-SSMIS Daily Polar Gridded Brightness Temperatures

    Data.gov (United States)

    National Aeronautics and Space Administration — NSIDC produces daily gridded brightness temperature data from orbital swath data generated by the Special Sensor Microwave/Imager (SSM/I) aboard the Defense...

  2. SMEX02 SSM/I Brightness Temperature Data, Iowa

    Data.gov (United States)

    National Aeronautics and Space Administration — The Special Sensor Microwave/Imager (SSM/I) is a seven-channel, four-frequency, linearly polarized passive microwave radiometric system. Data are brightness...

  3. CLASIC07 PALS Brightness Temperature Data V001

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains brightness temperature data obtained by the Passive Active L-band System (PALS) microwave aircraft radiometer instrument as part of the Cloud...

  4. Operational Bright-Band Snow Level Detection Using Doppler Radar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A method to detect the bright-band snow level from radar reflectivity and Doppler vertical velocity data collection with an atmospheric profiling Doppler radar. The...

  5. Visible Color and Photometry of Bright Materials on Vesta

    Science.gov (United States)

    Schroder, S. E.; Li, J. Y.; Mittlefehldt, D. W.; Pieters, C. M.; De Sanctis, M. C.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.; Keller, H. U.

    2012-01-01

    The Dawn Framing Camera (FC) collected images of the surface of Vesta at a pixel scale of 70 m in the High Altitude Mapping Orbit (HAMO) phase through its clear and seven color filters spanning from 430 nm to 980 nm. The surface of Vesta displays a large diversity in its brightness and colors, evidently related to the diverse geology [1] and mineralogy [2]. Here we report a detailed investigation of the visible colors and photometric properties of the apparently bright materials on Vesta in order to study their origin. The global distribution and the spectroscopy of bright materials are discussed in companion papers [3, 4], and the synthesis results about the origin of Vestan bright materials are reported in [5].

  6. A New Bond Albedo for Performing Orbital Debris Brightness to Size Transformations

    Science.gov (United States)

    Mulrooney, Mark K.; Matney, Mark J.

    2008-01-01

    We have developed a technique for estimating the intrinsic size distribution of orbital debris objects via optical measurements alone. The process is predicated on the empirically observed power-law size distribution of debris (as indicated by radar RCS measurements) and the log-normal probability distribution of optical albedos as ascertained from phase (Lambertian) and range-corrected telescopic brightness measurements. Since the observed distribution of optical brightness is the product integral of the size distribution of the parent [debris] population with the albedo probability distribution, it is a straightforward matter to transform a given distribution of optical brightness back to a size distribution by the appropriate choice of a single albedo value. This is true because the integration of a powerlaw with a log-normal distribution (Fredholm Integral of the First Kind) yields a Gaussian-blurred power-law distribution with identical power-law exponent. Application of a single albedo to this distribution recovers a simple power-law [in size] which is linearly offset from the original distribution by a constant whose value depends on the choice of the albedo. Significantly, there exists a unique Bond albedo which, when applied to an observed brightness distribution, yields zero offset and therefore recovers the original size distribution. For physically realistic powerlaws of negative slope, the proper choice of albedo recovers the parent size distribution by compensating for the observational bias caused by the large number of small objects that appear anomalously large (bright) - and thereby skew the small population upward by rising above the detection threshold - and the lower number of large objects that appear anomalously small (dim). Based on this comprehensive analysis, a value of 0.13 should be applied to all orbital debris albedo-based brightness-to-size transformations regardless of data source. Its prima fascia genesis, derived and constructed

  7. Global View of the Bright Material on Vesta

    Science.gov (United States)

    Zambon, F.; DeSanctis, C.; Schroeder, S.; Tosi, F.; Li, J.-Y.; Longobardo, A.; Ammannito, E.; Blewett, D. T.; Palomba, E.; Capaccioni, F.; hide

    2014-01-01

    At 525 km in mean diameter, Vesta is the second-most massive and one of the brightest asteroids of the main-belt. Here we give a global view of the bright material (BM) units on Vesta. We classified the BMs according to the normal visual albedo. The global albedo map of Vesta allows to be divided the surface into three principal types of terrains: bright regions, dark regions and intermediate regions. The distribution of bright regions is not uniform. The mid-southern latitudes contain the most bright areas, while the northern hemisphere is poor in bright regions. The analysis of the spectral parameters and the normal visual albedo show a dependence between albedo and the strength (depth) of ferrous iron absorption bands, strong bands correspond with high albedo units. Vesta's average albedo is 0.38, but there are bright material whose albedo can exceed 0.50. Only the E-Type asteroids have albedos comparable to those of the BMs on Vesta. The Dawn mission observed a large fraction of Vesta's surface at high spatial resolution, allowing a detailed study of the morphology and mineralogy of it. In particular, reflectance spectra provided by the Visible and InfraRed spectrometer (VIR), confirmed that Vesta's mineralogy is dominated by pyroxenes. All Vesta spectra show two strong absorption bands at approx 0.9 and 1.9 micron, typical of the pyroxenes and associated with the howardite, eucrite and diogenite (HED) meteorites.

  8. Synthesizing SMOS Zero-Baselines with Aquarius Brightness Temperature Simulator

    Science.gov (United States)

    Colliander, A.; Dinnat, E.; Le Vine, D.; Kainulainen, J.

    2012-01-01

    SMOS [1] and Aquarius [2] are ESA and NASA missions, respectively, to make L-band measurements from the Low Earth Orbit. SMOS makes passive measurements whereas Aquarius measures both passive and active. SMOS was launched in November 2009 and Aquarius in June 2011.The scientific objectives of the missions are overlapping: both missions aim at mapping the global Sea Surface Salinity (SSS). Additionally, SMOS mission produces soil moisture product (however, Aquarius data will eventually be used for retrieving soil moisture too). The consistency of the brightness temperature observations made by the two instruments is essential for long-term studies of SSS and soil moisture. For resolving the consistency, the calibration of the instruments is the key. The basis of the SMOS brightness temperature level is the measurements performed with the so-called zero-baselines [3]; SMOS employs an interferometric measurement technique which forms a brightness temperature image from several baselines constructed by combination of multiple receivers in an array; zero-length baseline defines the overall brightness temperature level. The basis of the Aquarius brightness temperature level is resolved from the brightness temperature simulator combined with ancillary data such as antenna patterns and environmental models [4]. Consistency between the SMOS zero-baseline measurements and the simulator output would provide a robust basis for establishing the overall comparability of the missions.

  9. Simultaneous determination of nickel and copper by H-point standard addition method-first-order derivative spectrophotometry in plant samples after separation and preconcentration on modified natural clinoptilolite as a new sorbent.

    Science.gov (United States)

    Roohparvar, Rasool; Taher, Mohammad Ali; Mohadesi, Alireza

    2008-01-01

    For the simultaneous determination of nickel(ll) and copper(ll) in plant samples, a rapid and accurate method was developed. In this method, solid-phase extraction (SPE) and first-order derivative spectrophotometry (FDS) are combined, and the result is coupled with the H-point standard addition method (HPSAM). Compared with normal spectrophotometry, derivative spectrophotometry offers the advantages of increased selectivity and sensitivity. As there is no need for carrying out any pretreatment of the sample, the spectrophotometry method is easy, but because of a high detection limit, it is not so practical. In order to decrease the detection limit, it is suggested to combine spectrophotometry with a preconcentration method such as SPE. In the present work, after separation and preconcentration of Ni(ll) and Cu(ll) on modified clinoptilolite zeolite that is loaded with 2-[1-(2-hydroxy-5-sulforphenyl)-3-phenyl-5-formaza-no]-benzoic acid monosodium salt (zincon) as a selective chromogenic reagent, FDS-HPSAM, which is a simple and selective spectrophotometric method, has been applied for simultaneous determination of these ions. With optimum conditions, the detection limit in original solutions is 0.7 and 0.5 ng/mL, respectively, for nickel and copper. The linear concentration ranges in the proposed method for nickel and copper ions in original solutions are 1.1 to 3.0 x 10(3) and 0.9 to 2.0 x 10(3) ng/mL, respectively. The recommended procedure is applied to successful determination of Cu(ll) and Ni(ll) in standard and real samples.

  10. Gamut relativity: a new computational approach to brightness and lightness perception.

    Science.gov (United States)

    Vladusich, Tony

    2013-01-09

    This article deconstructs the conventional theory that "brightness" and "lightness" constitute perceptual dimensions corresponding to the physical dimensions of luminance and reflectance, and builds in its place the theory that brightness and lightness correspond to computationally defined "modes," rather than dimensions, of perception. According to the theory, called gamut relativity, "blackness" and "whiteness" constitute the perceptual dimensions (forming a two-dimensional "blackness-whiteness" space) underlying achromatic color perception (black, white, and gray shades). These perceptual dimensions are postulated to be related to the neural activity levels in the ON and OFF channels of vision. The theory unifies and generalizes a number of extant concepts in the brightness and lightness literature, such as simultaneous contrast, anchoring, and scission, and quantitatively simulates several challenging perceptual phenomena, including the staircase Gelb effect and the effects of task instructions on achromatic color-matching behavior, all with a single free parameter. The theory also provides a new conception of achromatic color constancy in terms of the relative distances between points in blackness-whiteness space. The theory suggests a host of striking conclusions, the most important of which is that the perceptual dimensions of vision should be generically specified according to the computational properties of the brain, rather than in terms of "reified" physical dimensions. This new approach replaces the computational goal of estimating absolute physical quantities ("inverse optics") with the goal of computing object properties relatively.

  11. Spectroscopic investigation of a brightly colored psittacofulvin pigment from parrot feathers

    Science.gov (United States)

    Adamec, František; Greco, Jordan A.; LaFountain, Amy M.; Magdaong, Nikki M.; Fuciman, Marcel; Birge, Robert R.; Polívka, Tomáš; Frank, Harry A.

    2016-03-01

    Octadecaoctaenal is a psittacofulvin pigment associated with the bright red coloration of parrots. It consists of a linear polyene chain terminated by an aldehyde group and therefore provides an opportunity to examine the fundamental factors controlling the excited state ordering and dynamics of polyenals. Steady-state and ultrafast time-resolved spectroscopy were performed on octadecaoctaenal and a derivative in which the aldehyde group was converted to a methylenehydroxyl group. It was found that for octadecaoctaenal, solvent proticity was more important than polarity in determining its excited state lifetime. Theoretical computations were carried out to reveal the origin of the effect.

  12. A Zn-porphyrin complex contributes to bright red color in Parma ham

    OpenAIRE

    Wakamatsu, J.; Nishimura, T; Hattori, A.

    2004-01-01

    The Italian traditional dry-cured ham (Parma ham) shows a stable bright red color that is achieved without the use of nitrite and/or nitrate. In this study we examined the pigment spectroscopically, fluoroscopically and by using HPLC and ESI-HR-MASS analysis. Porphyrin derivative other than acid hematin were contained in the HCl-containing acetone extract from Parma ham. A strong fluorescence peak at 588 nm and a weak fluorescence peak at 641 nm were observed. By HPLC analysis the acetone ext...

  13. The Surface Brightness-color Relations Based on Eclipsing Binary Stars: Toward Precision Better than 1% in Angular Diameter Predictions

    Science.gov (United States)

    Graczyk, Dariusz; Konorski, Piotr; Pietrzyński, Grzegorz; Gieren, Wolfgang; Storm, Jesper; Nardetto, Nicolas; Gallenne, Alexandre; Maxted, Pierre F. L.; Kervella, Pierre; Kołaczkowski, Zbigniew

    2017-03-01

    In this study we investigate the calibration of surface brightness-color (SBC) relations based solely on eclipsing binary stars. We selected a sample of 35 detached eclipsing binaries with trigonometric parallaxes from Gaia DR1 or Hipparcos whose absolute dimensions are known with an accuracy better than 3% and that lie within 0.3 kpc from the Sun. For the purpose of this study, we used mostly homogeneous optical and near-infrared photometry based on the Tycho-2 and 2MASS catalogs. We derived geometric angular diameters for all stars in our sample with a precision better than 10%, and for 11 of them with a precision better than 2%. The precision of individual angular diameters of the eclipsing binary components is currently limited by the precision of the geometric distances (˜5% on average). However, by using a subsample of systems with the best agreement between their geometric and photometric distances, we derived the precise SBC relations based only on eclipsing binary stars. These relations have precisions that are comparable to the best available SBC relations based on interferometric angular diameters, and they are fully consistent with them. With very precise Gaia parallaxes becoming available in the near future, angular diameters with a precision better than 1% will be abundant. At that point, the main uncertainty in the total error budget of the SBC relations will come from transformations between different photometric systems, disentangling of component magnitudes, and for hot OB stars, the main uncertainty will come from the interstellar extinction determination. We argue that all these issues can be overcome with modern high-quality data and conclude that a precision better than 1% is entirely feasible.

  14. Derivative chameleons

    Energy Technology Data Exchange (ETDEWEB)

    Noller, Johannes, E-mail: johannes.noller08@imperial.ac.uk [Theoretical Physics, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2BZ (United Kingdom)

    2012-07-01

    We consider generalized chameleon models where the conformal coupling between matter and gravitational geometries is not only a function of the chameleon field φ, but also of its derivatives via higher order co-ordinate invariants (such as ∂{sub μ}φ∂{sup μ}φ,□φ,...). Specifically we consider the first such non-trivial conformal factor A(φ,∂{sub μ}φ∂{sup μ}φ). The associated phenomenology is investigated and we show that such theories have a new generic mass-altering mechanism, potentially assisting the generation of a sufficiently large chameleon mass in dense environments. The most general effective potential is derived for such derivative chameleon setups and explicit examples are given. Interestingly this points us to the existence of a purely derivative chameleon protected by a shift symmetry for φ → φ+c. We also discuss potential ghost-like instabilities associated with mass-lifting mechanisms and find another, mass-lowering and instability-free, branch of solutions. This suggests that, barring fine-tuning, stable derivative models are in fact typically anti-chameleons that suppress the field's mass in dense environments. Furthermore we investigate modifications to the thin-shell regime and prove a no-go theorem for chameleon effects in non-conformal geometries of the disformal type.

  15. A neurodynamical model of brightness induction in v1.

    Directory of Open Access Journals (Sweden)

    Olivier Penacchio

    Full Text Available Brightness induction is the modulation of the perceived intensity of an area by the luminance of surrounding areas. Recent neurophysiological evidence suggests that brightness information might be explicitly represented in V1, in contrast to the more common assumption that the striate cortex is an area mostly responsive to sensory information. Here we investigate possible neural mechanisms that offer a plausible explanation for such phenomenon. To this end, a neurodynamical model which is based on neurophysiological evidence and focuses on the part of V1 responsible for contextual influences is presented. The proposed computational model successfully accounts for well known psychophysical effects for static contexts and also for brightness induction in dynamic contexts defined by modulating the luminance of surrounding areas. This work suggests that intra-cortical interactions in V1 could, at least partially, explain brightness induction effects and reveals how a common general architecture may account for several different fundamental processes, such as visual saliency and brightness induction, which emerge early in the visual processing pathway.

  16. Bright light therapy of subsyndromal seasonal affective disorder in the workplace: morning vs. afternoon exposure.

    Science.gov (United States)

    Avery, D H; Kizer, D; Bolte, M A; Hellekson, C

    2001-04-01

    Bright light therapy in seasonal affective disorder (SAD) has been studied extensively. However, little attention has been given to subsyndromal seasonal affective disorder (SSAD) or the use of bright light in the workplace. Many patients using bright light boxes complain of the inconvenience of use. Much of this inconvenience involves the often-recommended early timing of the bright light therapy. Patients, who already have difficulty awakening, often have difficulty using the bright light therapy soon after awakening before going to work. If bright light could be used effectively in the workplace, the treatment would be more convenient; the improved convenience would probably improve compliance. In this study, we studied the effectiveness of bright light therapy in subjects with SSAD in the workplace, comparing morning bright light with afternoon bright light. Morning and afternoon bright light treatment (2500 lux) were compared in 30 subsyndromal seasonal affective disorder patients using the bright light therapy in the workplace. Hamilton Depression Ratings and subjective measures of mood, energy, alertness and productivity were assessed before and after 2 weeks of light therapy. Both morning and evening bright light significantly decreased the depression ratings and improved the subjective mood, energy, alertness and productivity scores. However, there were no significant differences between the two times of administration of the bright light treatment. Both bright light treatments were well tolerated. Bright light given in the workplace improves subjective ratings of mood, energy, alertness and productivity in SSAD subjects. Morning and afternoon bright lights resulted in similar levels of improvement.

  17. Bright and Not-So-Bright Prospects for Women in Physics in China-Beijing

    Science.gov (United States)

    Wu, Ling-An; Yang, Zhongqin; Ma, Wanyun

    2009-04-01

    Science in China-Beijing is enjoying a healthy increase in funding year by year, so the prospects for physicists are also bright. However, employment discrimination against women, formerly unthinkable, is becoming more and more explicit as the country evolves toward a market economy. Some recruitment notices bluntly state that only men will be considered, or impose restrictions upon potential female candidates. Female associate professors in many institutions are forced to retire at age 55, compared with 60 for men. This double-pinching discrimination against both younger and older women threatens to lead to a "pincer" effect, more serious than the "scissors" effect. Indeed, the ratio of senior-level women physicists in general has dropped significantly in recent years in China. Ironically, the number of female students applying for graduate studies is on the rise, as it is becoming increasingly difficult for them to compete with men in the job market with just an undergraduate degree. The Chinese Physical Society has made certain efforts to promote the image of women physicists, but it will take time and effort to reverse the trend.

  18. Bright spots of sustainable shark fishing.

    Science.gov (United States)

    Simpfendorfer, Colin A; Dulvy, Nicholas K

    2017-02-06

    Sharks, rays and chimeras (class Chondrichthyes; herein 'sharks') today face possibly the largest crisis of their 420 million year history. Tens of millions of sharks are caught and traded internationally each year, many populations are overfished to the point where global catch peaked in 2003, and a quarter of species have an elevated risk of extinction [1-3]. To some, the solution is to simply stop taking them from our oceans, or prohibit carriage, sale or trade in shark fins [4]. Approaches such as bans and alternative livelihoods for fishers (e.g. ecotourism) may play some role in controlling fishing mortality but will not solve this crisis because sharks are mostly taken as incidental catch and play an important role in food security [5-7]. Here, we show that moving to sustainable fishing is a feasible solution. In fact, approximately 9% of the current global catch of sharks, from at least 33 species with a wide range of life histories, is biologically sustainable, although not necessarily sufficiently managed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Laser interactions with high brightness electron beams

    Science.gov (United States)

    Malton, Stephen P.

    The International Linear Collider will be a high-precision machine to study the next energy frontier in particle physics. At the TeV energy scale, the ILC is expected to deliver luminosities in excess of 1034 cni" 2s_1. In order to achieve this, beam conditions must be monitored throughout the machine. Measurment of the beam emittance is essential to ensuring that the high luminosity can be provided at the interaction point. At the de sign beam sizes in the ILC beam delivery system, the Laserwire provides a non-invasive real-time method of measuring the emittance by the method of inverse Compton scattering. The prototype Laserwire at the PETRA stor age ring has produced consistent results with measured beam sizes of below 100 /nn. The Energy Recovery Linac Prototype (ERLP) is a technology testbed for the 4th Generation Light Source (4GLS). Inverse Compton scattering can be used in the ERLP as a proof of concept for a proposed 4GLS upgrade, and to produce soft X-rays for condensed matter experiments. The design constraints for the main running mode of the ERLP differ from those required for inverse Compton scattering. Suitable modifications to the optical lattice have been developed under the constraint that no new magnetic structures may be introduced, and the resulting photon distributions are described.

  20. High-brightness ultra-cold metastable neon-beam

    CERN Document Server

    Shimizu, Fujio

    2015-01-01

    This paper presents detailed characteristics of an ultra-cold bright metastable neon atomic beam which we have been using for atom-interferometric applications. The basis of the device is an atomic beam released from a magneto-optical trap (MOT) which is operated with a high intensity trapping laser, high magnetic quadrupole field, and large laser detuining. Mainly due to the complex structure of three dimensional magnetic field and laser beams, a bright small spot of atoms is formed near the center of the quadrupole magnetic field under an appropriate operating condition. We obtained the minimum trap diameter of 50 micron meter, the atomic density nearly 10^{13}cm^{-3}, and the atomic temperature slightly less than the Doppler limited temperature of 200 micro-K. By releasing trapped atoms we obtained an bright cold atomic beam which is not far from the collision limited atomic density.

  1. A high brightness probe of polymer nanoparticles for biological imaging

    Science.gov (United States)

    Zhou, Sirong; Zhu, Jiarong; Li, Yaping; Feng, Liheng

    2018-03-01

    Conjugated polymer nanoparticles (CPNs) with high brightness in long wavelength region were prepared by the nano-precipitation method. Based on fluorescence resonance energy transfer (FRET) mechanism, the high brightness property of the CPNs was realized by four different emission polymers. Dynamic light scattering (DLS) and scanning electron microscopy (SEM) displayed that the CPNs possessed a spherical structure and an average diameter of 75 nm. Analysis assays showed that the CPNs had excellent biocompatibility, good photostability and low cytotoxicity. The CPNs were bio-modified with a cell penetrating peptide (Tat, a targeted element) through covalent link. Based on the entire wave fluorescence emission, the functionalized CPNs1-4 can meet multichannel and high throughput assays in cell and organ imaging. The contribution of the work lies in not only providing a new way to obtain a high brightness imaging probe in long wavelength region, but also using targeted cell and organ imaging.

  2. Low dimensional neutron moderators for enhanced source brightness

    DEFF Research Database (Denmark)

    Mezei, Ferenc; Zanini, Luca; Takibayev, Alan

    2014-01-01

    In a recent numerical optimization study we have found that liquid para-hydrogen coupled cold neutron moderators deliver 3–5 times higher cold neutron brightness at a spallation neutron source if they take the form of a flat, quasi 2-dimensional disc, in contrast to the conventional more voluminous...... for cold neutrons. This model leads to the conclusions that the optimal shape for high brightness para-hydrogen neutron moderators is the quasi 1-dimensional tube and these low dimensional moderators can also deliver much enhanced cold neutron brightness in fission reactor neutron sources, compared...... to the much more voluminous liquid D2 or H2 moderators currently used. Neutronic simulation calculations confirm both of these theoretical conclusions....

  3. On the relation between zenith sky brightness and horizontal illuminance

    Science.gov (United States)

    Kocifaj, M.; Posch, Th.; Solano Lamphar, H. A.

    2015-01-01

    The effects of artificial light at night are an emergent research topic for astronomers, physicists, engineers and biologists around the world. This leads to a need for measurements of the night sky brightness (= diffuse luminance of the night sky) and nocturnal illuminance. Currently, the most sensitive light meters measure the zenith sky brightness in magV/arcsec2 or - less frequently - in cd m-2. However, the horizontal illuminance resulting only from the night sky is an important source of information that is difficult to obtain with common instruments. Here we present a set of approximations to convert the zenith luminance into horizontal illuminance. Three different approximations are presented for three idealized atmospheric conditions: homogeneous sky brightness, an isotropically scattering atmosphere and a turbid atmosphere. We also apply the resulting conversion formulae to experimental data on night sky luminance, obtained during the past three years.

  4. Effects of Bright Light Treatment on Psychomotor Speed in Athletes

    Directory of Open Access Journals (Sweden)

    Mikko Paavo Tulppo

    2014-05-01

    Full Text Available Purpose: A recent study suggests that transcranial brain targeted light treatment via ear canals may have physiological effects on brain function studied by functional magnetic resonance imaging (fMRI techniques in humans. We tested the hypothesis that bright light treatment could improve psychomotor speed in professional ice hockey players. Methods: Psychomotor speed tests with audio and visual warning signals were administered to a Finnish National Ice Hockey League team before and after 24 days of transcranial bright light or sham treatment. The treatments were given during seasonal darkness in the Oulu region (latitude 65 degrees north when the strain on the players was also very high (10 matches during 24 days. A daily 12-min dose of bright light or sham (n = 11 for both treatment was given every morning between 8–12 am at home with a transcranial bright light device. Mean reaction time and motor time were analyzed separately for both psychomotor tests. Analysis of variance for repeated measures adjusted for age was performed. Results: Time x group interaction for motor time with a visual warning signal was p = 0.024 after adjustment for age. In Bonferroni post-hoc analysis, motor time with a visual warning signal decreased in the bright light treatment group from 127 ± 43 to 94 ± 26 ms (p = 0.024 but did not change significantly in the sham group 121 ± 23 vs. 110 ± 32 ms (p = 0.308. Reaction time with a visual signal did not change in either group. Reaction or motor time with an audio warning signal did not change in either the treatment or sham group. Conclusion: Psychomotor speed, particularly motor time with a visual warning signal, improves after transcranial bright light treatment in professional ice-hockey players during the competition season in the dark time of the year.

  5. Bright solitons in non-equilibrium coherent quantum matter.

    Science.gov (United States)

    Pinsker, F; Flayac, H

    2016-01-01

    We theoretically demonstrate a mechanism for bright soliton generation in spinor non-equilibrium Bose-Einstein condensates made of atoms or quasi-particles such as polaritons in semiconductor microcavities. We give analytical expressions for bright (half) solitons as minimizing functions of a generalized non-conservative Lagrangian elucidating the unique features of inter and intra-competition in non-equilibrium systems. The analytical results are supported by a detailed numerical analysis that further shows the rich soliton dynamics inferred by their instability and mutual cross-interactions.

  6. HSV Brightness Factor Matching for Gesture Recognition System

    OpenAIRE

    Mokhtar M. Hasan; Pramod K. Mishra

    2010-01-01

    The main goal of gesture recognition research is to establish a system which can identify specific human gestures and use these identified gestures to be carried out by the machine, In this paper, we introduce a new method for gesture recognition that based on computing the local brightness for each block of the gesture image, the gesture image is divided into 25x25 blocks each of 5x5 block size, and we calculated the local brightness of each block, so, each gesture produces 25x25 features va...

  7. Alleyway Points

    DEFF Research Database (Denmark)

    Lunde Nielsen, Espen; Kruse Aagaard, Anders

    2017-01-01

    topografier. Alleyway Points består af en række eksperimenter, som søger at udforske denne sammenvævning af disse to parallelle domæner gennem en pendulering imellem det fysiske og det digitale. En gyde danner rammen om disse forsøg, hvor den etablerede punktsky i sig selv bliver anskuet som en digital......Forskelligartede former for fotogrammetri og 3D-scanning muliggør indfangelse af den fysiske verden i det digitale domæne. Dette har vist sig instrumentelt i et utal af forskellige henseender. Når virkeligheden bliver digitaliseret, bliver den frigjort fra sine materielle forpligtigelser: der er...... dialog og pendulering mellem de to domæner, hvor grænsen mellem, hvad der kan anskues som det virkelige og repræsentionen deraf, bliver gradvis mere utydelig. Dette adskiller sig fra to dominerende diskurser inden for arbejdsgange mellem det virkelige og det digitale, der ofte er ensrettede bevægelser...

  8. Making limb and nadir measurements comparable: A common volume study of PMC brightness observed by Odin OSIRIS and AIM CIPS

    Science.gov (United States)

    Benze, Susanne; Gumbel, Jörg; Randall, Cora E.; Karlsson, Bodil; Hultgren, Kristoffer; Lumpe, Jerry D.; Baumgarten, Gerd

    2018-01-01

    Combining limb and nadir satellite observations of Polar Mesospheric Clouds (PMCs) has long been recognized as problematic due to differences in observation geometry, scattering conditions, and retrieval approaches. This study offers a method of comparing PMC brightness observations from the nadir-viewing Aeronomy of Ice in the Mesosphere (AIM) Cloud Imaging and Particle Size (CIPS) instrument and the limb-viewing Odin Optical Spectrograph and InfraRed Imaging System (OSIRIS). OSIRIS and CIPS measurements are made comparable by defining a common volume for overlapping OSIRIS and CIPS observations for two northern hemisphere (NH) PMC seasons: NH08 and NH09. We define a scattering intensity quantity that is suitable for either nadir or limb observations and for different scattering conditions. A known CIPS bias is applied, differences in instrument sensitivity are analyzed and taken into account, and effects of cloud inhomogeneity and common volume definition on the comparison are discussed. Not accounting for instrument sensitivity differences or inhomogeneities in the PMC field, the mean relative difference in cloud brightness (CIPS - OSIRIS) is -102 ± 55%. The differences are largest for coincidences with very inhomogeneous clouds that are dominated by pixels that CIPS reports as non-cloud points. Removing these coincidences, the mean relative difference in cloud brightness reduces to -6 ± 14%. The correlation coefficient between the CIPS and OSIRIS measurements of PMC brightness variations in space and time is remarkably high, at 0.94. Overall, the comparison shows excellent agreement despite different retrieval approaches and observation geometries.

  9. Tertiary lignites of As Pontes (NW-Spain) - an example for the composition of bright coal layers and its implications for formation

    Energy Technology Data Exchange (ETDEWEB)

    Hagemann, H.W.; Pickel, W. [RWTH Aachen (Germany). Lehrstuhl fuer Geologie, Geochemie und Lagerstaetten des Erdoels und der Kohle; Cabrera, L.; Saez, A. [Barcelona Univ. (Spain). Dept. de Geologia Dinamica, Geofisica i Paleontologia

    1997-12-31

    The Tertiary lignite basin of As Pontes is characterized by the frequent occurrence of bright brown coal layers. These layers, macroscopically very similar to those described for example in the Weisselster Basin and various other lignite deposits were studied in detail mainly by means of organic petrography in one seam of the basin and the data were related to the brightness of the coals. The question, if the colour of lignite is mainly influenced by the original plant input or the depositional environment, is under strong controversial discussion up to now. The bright coals of the As Pontes Basin are mineral rich (especially in clay) and/or contain high amounts of lipid rich matter (liptinite), especially coalification products of cork-tissue (suberinite). The results of the study indicate that the bright coal is highly degraded in comparison to the dark coals of the same basin. The formation of bright, litinite/mineral-rich lignite layers occurred especially during early basin evolution stages influenced by water table oscillations. Sedimentological, petrographical and organic geochemical data point to the fact that, although the paleoenvironments, where peat deposition took place, did not experience drastic changes, they were affected by noticable variations in hydrochemistry and groundwater stability, related to the tectonic historical record of the basin and the paleoclimatic conditions. In summary the origin of the bright layers of the As Pontes lignite is mainly related to the depositional environment. (orig.)

  10. Two general fixed point principles and applications

    Directory of Open Access Journals (Sweden)

    Bapurao C. Dhage

    2016-06-01

    Full Text Available We present a couple of general fixed point principles using the constructive approach and derive some interesting well-known fixed point theorems in a metric space and a partially ordered metric space as corollaries. Our general fixed point principles include more than 100 fixed point theorems in different metric spaces as special cases.

  11. Matter-wave bright solitons in effective bichromatic lattice potentials

    Indian Academy of Sciences (India)

    Keywords. Bose–Einstein condensate; optical lattices; inhomogeneous nonlinearity. Abstract. Matter-wave bright solitons in bichromatic lattice potentials are considered and their dynamics for different lattice environments are studied. Bichromatic potentials are created from superpositions of (i) two linear optical lattices and ...

  12. Compact collimators for high brightness blue LEDs using dielectric multilayers

    NARCIS (Netherlands)

    Cornelissen, H.J.; Ma, H.; Ho, C.; Li, M.; Mu, C.

    2011-01-01

    A novel method is presented to inject the light of millimeter-sized high-brightness blue LEDs into light guides of submillimeter thickness. Use is made of an interference filter that is designed to pass only those modes that will propagate in the light guide by total internal reflection. Other modes

  13. Bright and dark soliton solutions of the (3+ 1)-dimensional ...

    Indian Academy of Sciences (India)

    In this paper, we obtain the 1-soliton solutions of the (3 + 1)-dimensional generalized Kadomtsev–Petviashvili (gKP) equation and the generalized Benjamin equation. By using two solitary wave ansatz in terms of sech p and tanh p functions, we obtain exact analytical bright and dark soliton solutions for the considered ...

  14. Brightness perception in low resolution images of 3d textures

    NARCIS (Netherlands)

    Spreeuwers, Lieuwe Jan; van der Heijden, Ferdinand; Siteur, J.

    1996-01-01

    A first step towards the analysis of the appearance of 3 dimensional textures is presented in this paper. It is assumed that the scale of the texture is small relative to the resolution of the camera. Therefore, the texture itself is not distinguishable.However, the perceived brightness of the

  15. Reducing Color/Brightness Interaction in Color Television

    Science.gov (United States)

    Marchman, Robert H.

    1987-01-01

    Proposed digitally sampled scan-conversion scheme for color television reduces unwanted interactions between chrominance and luminance signals. New scheme reduces luminance and chrominance bandwidth to increase frequency separation between signals. To avoid proportionally reducing horizontal brightness resolution and horizontal color resolution, horizontal interlace of luminance signal and two color-difference signals used.

  16. The bright optical afterglow of the long GRB 001007

    DEFF Research Database (Denmark)

    Ceron, J.M.C.; Castro-Tirado, A.J.; Gorosabel, J.

    2002-01-01

    We present optical follow up observations of the long GRB 001007 between 6.14 hours and similar to468 days after the event. An unusually bright optical afterglow (OA) was seen to decline following a steep power law decay with index alpha = -2.03 +/- 0.11, possibly indicating a break in the light ...

  17. The star-bright hour : [luuletused] / Betti Alver

    Index Scriptorium Estoniae

    Alver, Betti, 1906-1989

    2006-01-01

    Sisu: The star-bright hour ; Not a dream ; The Piper ; Corals in an ancent river. Luuletused pärinevad kogumikust "Tuulelaeval valgusest on aerud = Windship with Oars of Light. (Tallinn : Huma, 2001). Orig.: Tähetund ; Mitte viirastus, meelepett ; Vilepuhuja ; Korallid Emajões

  18. Time series analysis of bright galactic X-ray sources

    DEFF Research Database (Denmark)

    Priedhorsky, W. C.; Brandt, Søren; Lund, Niels

    1995-01-01

    We analyze 70 to 110 day data sets from eight bright galactic X-ray binaries observed by WATCH/Eureca, in search of periodic variations. We obtain new epochs for the orbital variation of Cyg X-3 and 4U 1700-37, and confirmation of a dip in Cyg X-1 at superior conjunction of the X-ray star. No evi...

  19. Bright infrared LEDs based on colloidal quantum-dots

    KAUST Repository

    Sun, Liangfeng

    2013-01-01

    Record-brightness infrared LEDs based on colloidal quantum-dots have been achieved through control of the spacing between adjacent quantum-dots. By tuning the size of quantum-dots, the emission wavelengths can be tuned between 900nm and 1650nm. © 2013 Materials Research Society.

  20. Bright soliton trains of trapped Bose-Einstein condensates

    OpenAIRE

    Al Khawaja, U.; Stoof, H.T C; Hulet, R. G.; Strecker, K. E.; Patridge, G.B.

    2002-01-01

    We variationally determine the dynamics of bright soliton trains composed of harmonically trapped Bose-Einstein condensates with attractive interatomic interactions. In particular, we obtain the interaction potential between two solitons. We also discuss the formation of soliton trains due to the quantum mechanical phase fluctuations of a one-dimensional condensate.

  1. RESPONSES OF BRIGHT, NORMAL, AND RETARDED CHILDREN TO LEARNING TASKS.

    Science.gov (United States)

    CARRIER, NEIL A.; AND OTHERS

    THE RELATIONSHIPS AMONG THE VARIABLES OF INTELLIGENCE, LEARNING TASK PERFORMANCE, EMOTIONAL TENSION, AND TASK MOTIVATION WERE STUDIED. ABOUT 120 BRIGHT, NORMAL, AND RETARDED CHILDREN PERFORMED SIX TRIALS OF NUMBER LEARNING, CONCEPT FORMATION, PROBLEM SOLVING, PERCEPTUAL-MOTOR COORDINATION, AND VERBAL LEARNING TASKS. DURING THE LEARNING SESSIONS,…

  2. Spectral Index Changes with Brightness for -Ray Loud Blazars

    Indian Academy of Sciences (India)

    Theoretic relation of spectral index changes depending on -ray brightness is obtained. The correlations between the ratio of -ray flux densities and the differences of the -ray spectral indices are discussed for the three subclasses of HBL, LBL and FSRQs. Results show that the ratio is related with the differences for the ...

  3. Bright soliton trains of trapped Bose-Einstein condensates

    NARCIS (Netherlands)

    Al Khawaja, U.; Stoof, H.T.C.; Hulet, R.G.; Strecker, K.E.; Patridge, G.B.

    2002-01-01

    We variationally determine the dynamics of bright soliton trains composed of harmonically trapped Bose-Einstein condensates with attractive interatomic interactions. In particular, we obtain the interaction potential between two solitons. We also discuss the formation of soliton trains due to the

  4. Henrietta Leavitt - A Bright Star of Astronomy; Resonance June 2001

    Indian Academy of Sciences (India)

    In fact, it was not known then that we live in a galaxy called the Milky Way, and that there were other galaxies in the universe like ours. This big handicap was elegantly removed by a momentous discovery by an American astronomer named Henrietta. Leavitt in 1912. She found a way to determine the actual brightness of a ...

  5. The star-bright hour : [poems] / Betti Alver

    Index Scriptorium Estoniae

    Alver, Betti, 1906-1989

    2003-01-01

    Autori lühitutvustus lk. 231. Sisu: The star-bright hour ; The debt ; Not a dream ; Fog-bound ; Corals in an Ancient river ; Frou-frou 1-3. Orig.: Tähetund ; Vilepuhuja ; Võlg ; "Mitte viirastus, meelepett..." ; Udus ; Korallid Emajões ; Froufrou 1-3

  6. Does bright light have an anxiolytic effect? - an open trial

    Directory of Open Access Journals (Sweden)

    Kripke Daniel F

    2007-10-01

    Full Text Available Abstract Background The aim of this open trial was to examine the influence of acute bright light exposure on anxiety in older and young adults. Methods This study was ancillary to a complex 5-day laboratory experiment testing phase-responses to light at all times of the day. On 3 consecutive days, participants were exposed to bright light (3,000 lux for 3 hours. The Spielberger State-Trait Anxiety Inventory (Form Y1 was administered 5 minutes before and 20 minutes after each treatment. Mean state anxiety before and after treatment were analyzed by age, sex, and time ANOVA. To avoid floor effects, only participants with baseline STAI levels of ≥ 25 were included. Results A significant anxiolytic effect of bright light was found for the mean data, as well as for each of the three days. No significant main effect of age, sex, or interaction of these factors with STAI change were found. Conclusion The results show consistent and significant (albeit modest anxiolytic effects following acute bright light exposure in low anxiety adults. Further randomized, controlled trials in clinically anxious individuals are needed.

  7. Modeling laser brightness from cross porro prism resonators

    CSIR Research Space (South Africa)

    Forbes, A

    2006-07-01

    Full Text Available Laser brightness is a parameter often used to compare high power laser beam delivery from various sources, and incorporates both the power contained in the particular mode, as well as the propagation of that mode through the beam quality factor, M2...

  8. Giant Low Surface Brightness Galaxies: Evolution in Isolation M. Das

    Indian Academy of Sciences (India)

    Abstract. Giant Low Surface Brightness (GLSB) galaxies are amongst the most massive spiral galaxies that we know of in our Universe. Although they fall in the class of late type spiral galaxies, their properties are far more extreme. They have very faint stellar disks that are extremely rich in neutral hydrogen gas but low in ...

  9. Giant Low Surface Brightness Galaxies: Evolution in Isolation

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Giant Low Surface Brightness (GLSB) galaxies are amongst the most massive spiral galaxies that we know of in our Universe. Although they fall in the class of late type spiral galaxies, their properties are far more extreme. They have very faint stellar disks that are extremely rich in neutral hydrogen gas but ...

  10. Evaluation of brightness temperature from a forward model of ...

    Indian Academy of Sciences (India)

    Ground-based microwave radiometers are getting great attention in recent years due to their capability to profile the temperature and humidity at high temporal and vertical resolution in the lower troposphere. The process of retrieving these parameters from the measurements of radiometric brightness temperature () ...

  11. Quadrature measurements of a bright squeezed state via sideband swapping

    DEFF Research Database (Denmark)

    Schneider, J.; Glockl, O.; Leuchs, G.

    2009-01-01

    The measurement of an arbitrary quadrature of a bright quantum state of light is a commonly requested action in many quantum information protocols, but it is experimentally challenging with previously proposed schemes. We suggest that the quadrature be measured at a specific sideband frequency of...

  12. The "Brightness Rules" Alternative Conception for Light Bulb Circuits

    Science.gov (United States)

    Bryan, Joel A.; Stuessy, Carol

    2006-01-01

    An alternative conception for the observed differences in light bulb brightness was revealed during an unguided inquiry investigation in which prospective elementary teachers placed identical bulbs in series, parallel, and combination direct current circuits. Classroom observations, document analyses, and video and audio transcriptions led to the…

  13. Protocol of networks using energy sharing collisions of bright solitons

    Indian Academy of Sciences (India)

    Soliton network; coupled nonlinear Schrödinger system; bright soliton; soliton collision. PACS Nos 42.65.Tg; 02.30. .... CNLS equations, we shall explore the dynamics of solitons in simple networks, i.e., PSG. In §4, the conclusion is ...... KS thank the Principal and management of Bishop Heber College for constant support.

  14. SKYMONITOR: A Global Network for Sky Brightness Measurements

    Science.gov (United States)

    Davis, Donald R.; Mckenna, D.; Pulvermacher, R.; Everett, M.

    2010-01-01

    We are implementing a global network to measure sky brightness at dark-sky critical sites with the goal of creating a multi-decade database. The heart of this project is the Night Sky Brightness Monitor (NSBM), an autonomous 2 channel photometer which measures night sky brightness in the visual wavelengths (Mckenna et al, AAS 2009). Sky brightness is measured every minute at two elevation angles typically zenith and 20 degrees to monitor brightness and transparency. The NSBM consists of two parts, a remote unit and a base station with an internet connection. Currently these devices use 2.4 Ghz transceivers with a range of 100 meters. The remote unit is battery powered with daytime recharging using a solar panel. Data received by the base unit is transmitted via email protocol to IDA offices in Tucson where it will be collected, archived and made available to the user community via a web interface. Two other versions of the NSBM are under development: one for radio sensitive areas using an optical fiber link and the second that reads data directly to a laptop for sites without internet access. NSBM units are currently undergoing field testing at two observatories. With support from the National Science Foundation, we will construct and install a total of 10 units at astronomical observatories. With additional funding, we will locate additional units at other sites such as National Parks, dark-sky preserves and other sites where dark sky preservation is crucial. We will present the current comparison with the National Park Service sky monitoring camera. We anticipate that the SKYMONITOR network will be functioning by the end of 2010.

  15. The brightness of lights on Earth at night, digitally recorded by DMSP satellite

    Science.gov (United States)

    Croft, Thomas A.

    1979-01-01

    The U.S. Air Force has operated its Defense Meteorological Satellite Program (DMSP) for nearly a decade, and film images from the system have been openly available since 1973. Films are well suited for the study of weather, and users of such films have derived much useful data. For many potential remote sensing applications, however, a quantitative measurement of the brightness of the imaged light patterns is needed, and it cannot be extracted with adequte accuracy from the films. Such information is contained in the telemetry from the spacecraft and is retained on digital tapes, which store the images for a few days while they await filming. For practical reasons, it has not heretofore been feasible for the Air Force to provide a remote-sensing user with these digital data, and the quantitative brightness information has been lost with the erasure of tapes for re-use. For the purpose of evaluation of tapes as a means for remote sensing, the Air Force recently did provide to the author six examples containing records of nighttime DMSP imagery similar to that which has previously 1 been evaluated by SRI International in a film format. The digital data create many new applications for these images, owing to a combination of several factors, the most important of which are the preservation of photometric information and of full spatial resolution. In this evaluation, stress has been placed upon determination of the broad potential value of the data rather than the full exploitation of any one aspect of it. The effort was guided by an objective to develop handling methods for the vast body of numbers--methods which will be practical for use in a research or engineering environment where budgets are limited, and specialized capabilities and image reproduction equipment has not already been developed. We report the degree of success obtained in this effort, pointing out the relative strengths and the relative limitations, as compared to the sophisticated, weather

  16. Comparison of point clouds derived from aerial image matching with data from airborne laser scanning. (Polish Title: Porównanie wóaściwości chmury punktów wygenerowanej metodą dopasowania obrazów zdjęć lotniczych z danymi z lotniczego skanowania)

    Science.gov (United States)

    Dominik, W.

    2014-12-01

    The aim of this study was to investigate the properties of point clouds derived from aerial image matching and to compare them with point clouds from airborne laser scanning. A set of aerial images acquired in years 2010-2013 over the city of Elblag were used for the analysis. Images were acquired with the use of three digital cameras: DMC II 230, DMC I and DigiCAM60 with a GSD varying from 4.5 cm to 15 cm. Eight sets of images that were used in the study were acquired at different stages of the growing season - from March to December. Two LiDAR point clouds were used for the comparison - one with a density of 1.3 p/m2 and a second with a density of 10 p/m2. Based on the input images point clouds were created with the use of the semi-global matching method. The properties of the obtained point clouds were analyzed in three ways: - by the comparison of the vertical accuracy of point clouds with reference to a terrain profile surveyed on bare ground with GPS-RTK method - by visual assessment of point cloud profiles generated both from SGM and LiDAR point clouds - by visual assessment of a digital surface model generated from a SGM point cloud with reference to a digital surface model generated from a LiDAR point cloud. The conducted studies allowed a number of observations about the quality of SGM point clouds to be formulated with respect to different factors. The main factors having influence on the quality of SGM point clouds are GSD and base/height ratio. The essential problem related to SGM point clouds are areas covered with vegetation where SGM point clouds are visibly worse in terms of both accuracy and the representation of terrain surface. It is difficult to expect that in these areas SGM point clouds could replace LiDAR point clouds. This leads to a general conclusion that SGM point clouds are less reliable, more unpredictable and are dependent on more factors than LiDAR point clouds. Nevertheless, SGM point clouds generated with appropriate parameters can

  17. A phase response curve to single bright light pulses in human subjects

    Science.gov (United States)

    Khalsa, Sat Bir S.; Jewett, Megan E.; Cajochen, Christian; Czeisler, Charles A.

    2003-01-01

    The circadian pacemaker is differentially sensitive to the resetting effects of retinal light exposure, depending upon the circadian phase at which the light exposure occurs. Previously reported human phase response curves (PRCs) to single bright light exposures have employed small sample sizes, and were often based on relatively imprecise estimates of circadian phase and phase resetting. In the present study, 21 healthy, entrained subjects underwent pre- and post-stimulus constant routines (CRs) in dim light (approximately 2-7 lx) with maintained wakefulness in a semi-recumbent posture. The 6.7 h bright light exposure stimulus consisted of alternating 6 min fixed gaze (approximately 10 000 lx) and free gaze (approximately 5000-9000 lx) exposures. Light exposures were scheduled across the circadian cycle in different subjects so as to derive a PRC. Plasma melatonin was used to determine the phase of the onset, offset, and midpoint of the melatonin profiles during the CRs. Phase shifts were calculated as the difference in phase between the pre- and post-stimulus CRs. The resultant PRC of the midpoint of the melatonin rhythm revealed a characteristic type 1 PRC with a significant peak-to-trough amplitude of 5.02 h. Phase delays occurred when the light stimulus was centred prior to the critical phase at the core body temperature minimum, phase advances occurred when the light stimulus was centred after the critical phase, and no phase shift occurred at the critical phase. During the subjective day, no prolonged 'dead zone' of photic insensitivity was apparent. Phase shifts derived using the melatonin onsets showed larger magnitudes than those derived from the melatonin offsets. These data provide a comprehensive characterization of the human PRC under highly controlled laboratory conditions.

  18. Stability of the nine sky quality meters in the Dutch night sky brightness monitoring network.

    Science.gov (United States)

    den Outer, Peter; Lolkema, Dorien; Haaima, Marty; van der Hoff, Rene; Spoelstra, Henk; Schmidt, Wim

    2015-04-22

    In the context of monitoring abundance of artificial light at night, the year-to-year stability of Sky Quality Meters (SQMs) is investigated by analysing intercalibrations derived from two measurement campaigns that were held in 2011 and 2012. An intercalibration comprises a light sensitivity factor and an offset for each SQM. The campaigns were concerned with monitoring measurements, each lasting one month. Nine SQMs, together forming the Night Sky Brightness Monitoring network (MHN) in The Netherlands, were involved in both campaigns. The stability of the intercalibration of these instruments leads to a year-to-year uncertainty (standard deviation) of 5% in the measured median luminance occurring at the MHN monitoring locations. For the 10-percentiles and 90-percentiles, we find 8% and 4%, respectively. This means that, for urban and industrial areas, changes in the sky brightness larger than 5% become detectable. Rural and nature areas require an 8%-9% change of the median luminance to be detectable. The light sensitivety agrees within 8% for the whole group of SQMs.

  19. Simulations of Radar Bright Band at Multiple Frequencies and Its Comparisons with Airborne Radar Measurements

    Science.gov (United States)

    Liao, L.; Meneghini, R.

    2010-12-01

    The melting layer, often observed by the radar as a layer of enhanced radar reflectivity (the so-called radar bright band), is an important meteorological process. An understanding of the microphysical properties of the melting hydrometeors and their electric scattering and propagation effects is of great importance in accurately estimating parameters of the precipitation from spaceborne radar and radiometers, such as TRMM PR and TMI and future GPM DPR and GMI. However, one of the most difficult problems in the study of the radar signature of the melting layer is the determination of the effective dielectric constants of melting hydrometeors. Although a number of mixing formulas are available to compute the effective dielectric constants of dry and melting snow, their results vary to a great extent when the particles are partially melted. Furthermore, it is physically unclear as to how to select among these various formulas. In this study, we first derive the effective dielectric constants of uniformly mixed snow and water particles at X-, Ku-, Ka- and W-bands from their internal electric fields by using a high-resolution computational model in which the particles are precisely described not only by shape but also by particle composition. The stratified-sphere scattering model, a sphere composed of multiple layers, is then employed to compute scattering parameters for non-uniformly melting hydrometeors whose fractional water content is prescribed as a function of the radius of the sphere. In conjunction with a melting layer model that describes the melting fractions and fall velocities of hydrometeors as a function of the distance below the 0C isotherm, the radar bright-band profiles are simulated for air- or space-borne radars operating at X-, Ku-, Ka- and W-bands. These simulated profiles will then be compared with the simultaneous measurements of the bright band made by the NICT (then the Communications Research Lab. of Japan) X- and Ka-band airborne radar

  20. Extremely High Current, High-Brightness Energy Recovery Linac

    CERN Document Server

    Ben-Zvi, Ilan; Beavis, Dana; Blaskiewicz, Michael; Bluem, Hans; Brennan, Joseph M; Burger, Al; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Cole, Michael; Connolly, Roger; Delayen, Jean R; Favale, Anthony; Gassner, David M; Grimes, Jacob T; Hahn, Harald; Hershcovitch, Ady; Holmes, Douglas; Hseuh Hsiao Chaun; Johnson, Peter; Kayran, Dmitry; Kewisch, Jorg; Kneisel, Peter; Lambiase, Robert; Litvinenko, Vladimir N; McIntyre, Gary; Meng, Wuzheng; Nehring, Thomas; Nicoletti, Tony; Oerter, Brian; Pate, David; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Roser, Thomas; Russo, Thomas; Scaduto, Joseph; Schultheiss, Tom; Segalov, Zvi; Smith, Kevin T; Todd, Alan M M; Warren-Funk, L; Williams, Neville; Wu, Kuo-Chen; Yakimenko, Vitaly; Yip, Kin; Zaltsman, Alex; Zhao, Yongxiang

    2005-01-01

    Next generation ERL light-sources, high-energy electron coolers, high-power Free-Electron Lasers, powerful Compton X-ray sources and many other accelerators were made possible by the emerging technology of high-power, high-brightness electron beams. In order to get the anticipated performance level of ampere-class currents, many technological barriers are yet to be broken. BNL's Collider-Accelerator Department is pursuing some of these technologies for its electron cooling of RHIC application, as well as a possible future electron-hadron collider. We will describe work on CW, high-current and high-brightness electron beams. This will include a description of a superconducting, laser-photocathode RF gun and an accelerator cavity capable of producing low emittance (about 1 micron rms normalized) one nano-Coulomb bunches at currents of the order of one ampere average.

  1. Bright breathers in nonlinear left-handed metamaterial lattices

    Science.gov (United States)

    Koukouloyannis, V.; Kevrekidis, P. G.; Veldes, G. P.; Frantzeskakis, D. J.; DiMarzio, D.; Lan, X.; Radisic, V.

    2018-02-01

    In the present work, we examine a prototypical model for the formation of bright breathers in nonlinear left-handed metamaterial lattices. Utilizing the paradigm of nonlinear transmission lines, we build a relevant lattice and develop a quasi-continuum multiscale approximation that enables us to appreciate both the underlying linear dispersion relation and the potential for bifurcation of nonlinear states. We focus here, more specifically, on bright discrete breathers which bifurcate from the lower edge of the linear dispersion relation at wavenumber k=π . Guided by the multiscale analysis, we calculate numerically both the stable inter-site centered and the unstable site-centered members of the relevant family. We quantify the associated stability via Floquet analysis and the Peierls-Nabarro barrier of the energy difference between these branches. Finally, we explore the dynamical implications of these findings towards the potential mobility or lack thereof (pinning) of such breather solutions.

  2. Improvement in brightness of multicusp-plasma ion source

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Q.; Jiang, X.; King, T-J.; Leung, K-N.; Standiford, K.; Wilde, S.B.

    2002-05-24

    The beam brightness of a multicusp-plasma ion source has been substantially improved by optimizing the source configuration and extractor geometry. The current density of a 2 keV He{sup +} beam extracted from a 7.5-cm-diameter source operating at 2.5 kW RF power is {approx}100 mA/cm{sup 2}, which is {approx}10 times larger than that of a beam extracted from a 5-cm-diameter source operating at 1 kW RF power. A smaller focused beam spot size is achieved with a counter-bored extractor instead of a conventional (''through-hole'') extractor, resulting another order of magnitude improvement in beam current density. Measured brightness can be as high as 440 A/cm{sup 2}Sr, which represents a 30 times improvement over prior work.

  3. The ASAS-SN bright supernova catalogue - III. 2016

    Science.gov (United States)

    Holoien, T. W.-S.; Brown, J. S.; Stanek, K. Z.; Kochanek, C. S.; Shappee, B. J.; Prieto, J. L.; Dong, Subo; Brimacombe, J.; Bishop, D. W.; Bose, S.; Beacom, J. F.; Bersier, D.; Chen, Ping; Chomiuk, L.; Falco, E.; Godoy-Rivera, D.; Morrell, N.; Pojmanski, G.; Shields, J. V.; Strader, J.; Stritzinger, M. D.; Thompson, Todd A.; Woźniak, P. R.; Bock, G.; Cacella, P.; Conseil, E.; Cruz, I.; Fernandez, J. M.; Kiyota, S.; Koff, R. A.; Krannich, G.; Marples, P.; Masi, G.; Monard, L. A. G.; Nicholls, B.; Nicolas, J.; Post, R. S.; Stone, G.; Wiethoff, W. S.

    2017-11-01

    This catalogue summarizes information for all supernovae discovered by the All-Sky Automated Survey for SuperNovae (ASAS-SN) and all other bright (mpeak ≤ 17), spectroscopically confirmed supernovae discovered in 2016. We then gather the near-infrared through ultraviolet magnitudes of all host galaxies and the offsets of the supernovae from the centres of their hosts from public data bases. We illustrate the results using a sample that now totals 668 supernovae discovered since 2014 May 1, including the supernovae from our previous catalogues, with type distributions closely matching those of the ideal magnitude limited sample from Li et al. This is the third of a series of yearly papers on bright supernovae and their hosts from the ASAS-SN team.

  4. Changes in the brightness of Jupiter's hemispheres again become periodic

    Science.gov (United States)

    Vidmachenko, A. P.

    2017-05-01

    Our analysis of data on relative brightness distribution along the central meridian of Jupiter showed that the ratio of brightness of northern and southern tropical zones Aj=BNTrZ/BSTrZ is a good index of activity of processes in Jovian atmosphere. In the years when the influence of solar activity is synchronized with the seasonal changes of irradiation of the northern and southern hemisphere, we note an increasing of the correlation of the activity index Aj with the periodic curve for change of distance to Sun at moving of planet on orbit. Analysis of Jupiter's images obtained in 2014-2017 showed, that if in 1998-2013 synchronization of change the Aj with the curve of change distance to the Sun when the planet moved on orbit, was somewhat disrupted; but in 2015-2017 such a correlation began to recover.

  5. Origin of low surface brightness galaxies: a dynamical study

    Science.gov (United States)

    Garg, Prerak; Banerjee, Arunima

    2017-11-01

    Low Surface Brightness Galaxies (LSBs), inspite of being gas rich, have low star formation rates and are therefore low surface brightness in nature. We calculate QRW, the 2-component disc stability parameter as proposed by Romeo & Wiegert, as a function of galactocentric radius R for a sample of five LSBs, for which mass models, as obtained from HI 21cm radio-synthesis observations and R-band photometry, were available in the literature. We find that the median value of Q_{RW}^{min}, the minimum of QRW over R, lies between 2.6 and 3.1 for our sample LSBs, which is higher than the median value of 1.8 ± 0.3 for Q_{RW}^{min} for a sample of high surface brightness galaxies (HSBs) as obtained in earlier studies. This clearly shows that LSBs have more stable discs than HSBs, which could explain their low star formation rates and, possibly, their low surface brightness nature. Interestingly, the calculated values of QRW decrease only slightly (median Q_{RW}^{min} ˜ 2.3-3) if the discs were taken to respond to the gravitational potential of the dark matter halo only, but reduce by ˜ a factor of 2-3 (median Q_{RW}^{min} ˜ 0.7-1.5) if they respond to their self-gravity alone. This implies that the dark matter halo is crucial in regulating disc stability in LSBs, which may have important implications for models of galaxy formation and evolution.

  6. Snap-shot survey of compact, radio-bright SNRs

    Science.gov (United States)

    Garmire, Gordon

    2008-09-01

    We propose to observe a set of radio-bright remnants (SNRs) previously unobserved in X-rays. The SNRs have flat, non-thermal spectra suggesting efficient particle acceleration at the shock front. We also expect to find new pulsars or neutron stars within these remnants. These makes the selected SNRs good candidates for future TeV and GeV detections. The selected SNRs are also compact enough to be imaged within the ACIS-I field of view.

  7. Facilitating the Transition from Bright to Dim Environments

    Science.gov (United States)

    2016-03-04

    librarian or other person designated to request documents from DTIC. Change of Address Organizations receiving reports from the U.S. Army...USAARL Report No. 2016-17 Facilitating the Transition from Bright to Dim Environments By David Walsh1, Morris R. Lattimore1, David L. Still1... ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S

  8. Near-Real-Time DMSP SSM/I-SSMIS Daily Polar Gridded Brightness Temperatures

    Data.gov (United States)

    National Aeronautics and Space Administration — The Near-Real-Time DMSP SSM/I-SSMIS Daily Polar Gridded Brightness Temperature product provides near-real-time brightness temperatures for both the Northern and...

  9. Cell structure imaging with bright and homogeneous nanometric light source.

    Science.gov (United States)

    Fukuta, Masahiro; Ono, Atsushi; Nawa, Yasunori; Inami, Wataru; Shen, Lin; Kawata, Yoshimasa; Terekawa, Susumu

    2017-04-01

    Label-free optical nano-imaging of dendritic structures and intracellular granules in biological cells is demonstrated using a bright and homogeneous nanometric light source. The optical nanometric light source is excited using a focused electron beam. A zinc oxide (ZnO) luminescent thin film was fabricated by atomic layer deposition (ALD) to produce the nanoscale light source. The ZnO film formed by ALD emitted the bright, homogeneous light, unlike that deposited by another method. The dendritic structures of label-free macrophage receptor with collagenous structure-expressing CHO cells were clearly visualized below the diffraction limit. The inner fiber structure was observed with 120 nm spatial resolution. Because the bright homogeneous emission from the ZnO film suppresses the background noise, the signal-to-noise ratio (SNR) for the imaging results was greater than 10. The ALD method helps achieve an electron beam excitation assisted microscope with high spatial resolution and high SNR. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Death of Darkness: Artificial Sky Brightness in the Anthropocene

    Science.gov (United States)

    Zender, C. S.

    2016-12-01

    Many species (including ours) need darkness to survive and thrive yet light pollution in the anthropocene has received scant attention in Earth System Models (ESMs). Anthropogenic aerosols can brighten background sky brightness and reduce the contrast between skylight and starlight. These are both aesthetic and health-related issues due to their accompanying disruption of circadian rhythms. We quantify aerosol contributions to light pollution using a single-column night sky model, NiteLite, suitable for implementation in ESMs. NiteLite accounts for physiologcal (photopic and scotopic vision, retinal diameter/age), anthropogenic (light and aerosol pollution properties), and natural (surface albedo, trace gases) effects on background brightness and threshold visibility. We find that stratospheric aerosol injection contemplated as a stop-gap measure to counter global warming would increase night-sky brightness by about 25%, and thus eliminate last pristine dark sky areas on Earth. Our results suggest that ESMs incorporate light pollution so that associated societal impacts can be better quantified and included in policy deliberations.

  11. Bright Soil Churned by Spirit's Sol 1861 Drive

    Science.gov (United States)

    2009-01-01

    NASA's Mars Exploration Rover Spirit drove 22.7 meters (74 feet) toward the southwest on the 1,861st Martian day, or sol, of Spirit's mission on Mars (March 28, 2009). After the drive, the rover took this image with its front hazard-avoidance camera, looking back at the tracks from the drive. As usual since losing the use of its right-front wheel in 2006, Spirit drove backwards. The immobile right-front wheel churned up a long stripe of bright soil during this drive. Where Spirit has found such bright soil in the past, subsequent analysis of the composition found concentrations of sulfur or silica that testified to past action of water at the site. When members of the rover team saw the large quantity of bright soil exposed by the Sol 1861 drive, they quickly laid plans to investigate the composition with Spirit's alpha particle X-ray spectrometer. The Sol 1861 drive took the rover past the northwest corner of the low plateau called 'Home Plate,' making progress on a route around the western side of Home Plate. The edge of Home Plate forms the horizon on the right side of this image. Husband Hill is on the horizon on the left side. For scale, the parallel rover wheel tracks are about 1 meter (40 inches) apart. The rover's hazard-avoidance cameras take 'fisheye' wide-angle images.

  12. Achromatic form perception is based on luminance, not brightness.

    Science.gov (United States)

    Shioiri, S; Cavanagh, P

    1992-10-01

    Two figures were examined, one a subjective disk and the other a cup whose shape was revealed by shadows. The figures were presented in a single color on a background of a different color, and the observers adjusted the radiance of one color until, in the first case, the vividness of the subjective contour reached a minimum (minimum subjective contour) or, in the second case, the impression of depth that is due to shadows disappeared (shadow disappearance). The results for these two tasks followed the data for minimum flicker matches (made with the same stimuli) much more closely than those for direct brightness matching. We therefore claim that achromatic form perception in general and subjective contour and shadow perception in particular are based on the intensity dimension measured by flicker photometry, not on that measured by brightness matching. Finally, in agreement with these findings, bleaching of short-wavelength sensitive cones did not affect settings for subjective contours, shadows, or flicker photometry but did affect brightness matching.

  13. SMOS brightness temperature assimilation into the Community Land Model

    Directory of Open Access Journals (Sweden)

    D. Rains

    2017-11-01

    Full Text Available SMOS (Soil Moisture and Ocean Salinity mission brightness temperatures at a single incident angle are assimilated into the Community Land Model (CLM across Australia to improve soil moisture simulations. Therefore, the data assimilation system DasPy is coupled to the local ensemble transform Kalman filter (LETKF as well as to the Community Microwave Emission Model (CMEM. Brightness temperature climatologies are precomputed to enable the assimilation of brightness temperature anomalies, making use of 6 years of SMOS data (2010–2015. Mean correlation R with in situ measurements increases moderately from 0.61 to 0.68 (11 % for upper soil layers if the root zone is included in the updates. A reduced improvement of 5 % is achieved if the assimilation is restricted to the upper soil layers. Root-zone simulations improve by 7 % when updating both the top layers and root zone, and by 4 % when only updating the top layers. Mean increments and increment standard deviations are compared for the experiments. The long-term assimilation impact is analysed by looking at a set of quantiles computed for soil moisture at each grid cell. Within hydrological monitoring systems, extreme dry or wet conditions are often defined via their relative occurrence, adding great importance to assimilation-induced quantile changes. Although still being limited now, longer L-band radiometer time series will become available and make model output improved by assimilating such data that are more usable for extreme event statistics.

  14. The calibration of read-out-streak photometry in the XMM-Newton Optical Monitor and the construction of a bright-source catalogue

    Science.gov (United States)

    Page, M. J.; Chan, N.; Breeveld, A. A.; Talavera, A.; Yershov, V.; Kennedy, T.; Kuin, N. P. M.; Hancock, B.; Smith, P. J.; Carter, M.

    2017-04-01

    The dynamic range of the XMM-Newton Optical Monitor (XMM-OM) is limited at the bright end by coincidence loss, the superposition of multiple photons in the individual frames recorded from its micro-channel-plate (MCP) intensified charge-coupled device (CCD) detector. One way to overcome this limitation is to use photons that arrive during the frame transfer of the CCD, forming vertical read-out streaks for bright sources. We calibrate these read-out streaks for photometry of bright sources observed with XMM-OM. The bright-source limit for read-out-streak photometry is set by the recharge time of the MCPs. For XMM-OM, we find that the MCP recharge time is 5.5 × 10-4 s. We determine that the effective bright limits for read-out-streak photometry with XMM-OM are approximately 1.5 mag brighter than the bright-source limits for normal aperture photometry in full-frame images. This translates into bright-source limits in Vega magnitudes of UVW2=7.1, UVM2=8.0, UVW1=9.4, U=10.5, B=11.5, V=10.2, and White=12.5 for data taken early in the mission. The limits brighten by up to 0.2 mag, depending on filter, over the course of the mission as the detector ages. The method is demonstrated by deriving UVW1 photometry for the symbiotic nova RR Telescopii, and the new photometry is used to constrain the e-folding time of its decaying ultraviolet (UV) emission. Using the read-out-streak method, we obtain photometry for 50 per cent of the missing UV source measurements in version 2.1 of the XMM-Newton Serendipitous UV Source Survey catalogue.

  15. Observations of Bright Comets in CARA Archives I: Years 2002-2006

    Science.gov (United States)

    Szabó, Gyula M.; Milani, Giannantonio; Vinante, Carlo; Ligustri, Rolando; Sostero, Giovanni; Trabatti, Roberto

    2010-12-01

    We have launched the Cometary Archives for Amateur Astronomers, CARA, aiming at coordinated collection of homogeneous, long-time based, continuous data set of bright comet observations. The project is based on a collaboration between professional and amateur astronomers. The archived quantity is a set of the photometric Afρ, measured in I, R or red continuum 647/10 nm filters. To derive coma profiles, Afρ is measured in at least different radii selected from a set of 50,000, 25,000, 12,500, 6,000 and 3,000 km. The data are free to download for registered users, special requests are available upon personal contact. We also provide aspecific code with a tutorial for the aperture photrometry of comets. The purpose of this paper is to introduce the observing methods, tools, software supports and web resources of project CARA.

  16. Modelling SMOS brightness temperature by use of coupled SVAT and radiative transfer models over the Valencia Anchor Station

    Science.gov (United States)

    Juglea, S.; Kerr, Y.; Mialon, A.; Lopez-Baeza, E.; Cano, A.; Calvet, J. C.; Albitar, A.; Wigneron, J. P.

    2009-04-01

    Soil moisture is a key variable that controls water and heat energy interactions occurring at the land atmosphere interface. This parameter, very important for the weather and climate modelling, is not well monitored at a global scale. A number of experiments have shown the high potential of L-band microwave radiometry for monitoring surface soil moisture. In this context, the SMOS (Soil Moisture and Ocean Salinity) mission was designed to observe soil moisture over continental surfaces as well as ocean salinity. Due to be launched in summer 2009, it will provide global soil moisture maps every 3 days at least, with an average spatial resolution of 40 km x 40 km. The VAS (Valencia Anchor Station) experimental site, in Spain, is a cornerstone of the SMOS Cal/Val plan. It is a semiarid environment and is characterized by an extensive set of measurements at different levels (in the atmosphere and in the soil) in order to derive surface energy fluxes. In the framework of SMOS preparation, the research presented here deals with the use of surface variables from the VAS site to simulate passive microwave brightness temperature so as to have Satellite "match ups" for CalVal and to test retrieval algorithms. First, ground and meteorological measurements from the VAS site are used to simulate soil moisture using a Soil-Vegetation-Atmosphere-Transfer (SVAT) model (ISBA) from Météo France. In order to validate this approach, a point to point comparison with ground measurements has been done. We obtain a very good agreement between the simulated and measured soil moisture and we find that, as expected, the simulated soil moisture is mostly driven by precipitation patterns. Then, we propose a spatialization method using all the available data in order to have soil moisture estimates representative of a SMOS pixel. The results are compared with remotely sensed data such as soil moisture from AMSR-E. An amplitude difference between both soil moisture data is observed but also a

  17. Fixed points of periodic maps.

    Science.gov (United States)

    Cappell, S E; Shaneson, J L

    1980-09-01

    Let f be a periodic differentiable map from a sphere to itself. A well-known conjecture of Smith asserts that in many cases (e.g., when the fixed points are isolated) the derivatives of f at its fixed points, regarded as Jacobian matrices, are linearly similar. Here we give counterexamples to this conjecture. The results show that, in many cases, these Jacobian matrices are only nonlinearly similar. This uses our recent discovery of orthogonal matrices which are nonlinearly similar without being linearly similar. Some results on general smooth actions of finite groups on differentiable manifolds are presented; the topological equivalence of their tangential representations at the fixed points is studied.

  18. The Physics and Applications of High Brightness Beams: Working Group A Summary on High Brightness Beam Production

    Energy Technology Data Exchange (ETDEWEB)

    Schmerge, John

    2003-03-19

    Working group A was devoted to high brightness beam production and characterization. The presentations and discussions could be categorized as cathode physics, new photoinjector designs, computational modeling of high brightness beams, and new experimental methods and results. Several novel injector and cathode designs were presented. However, a standard 1.5 cell rf photoinjector is still the most common source for high brightness beams. New experimental results and techniques were presented and thoroughly discussed. The brightest beam produced in a rf photoinjector published at the time of the workshop is approximately 2 10{sup 14} A/(m-rad){sup 2} at Sumitomo Heavy Industries in Japan with 1 nC of charge, a 9 ps FWHM long laser pulse and a normalized transverse emittance of 1.2 pm. The emittance was achieved by utilizing a temporally flat laser pulse which decreased the emittance by an estimated factor of 2 from the beam produced with a Gaussian pulse shape with an identical pulse length.

  19. Flattening and surface-brightness of the fast-rotating star δ Persei with the visible VEGA/CHARA interferometer

    Science.gov (United States)

    Challouf, M.; Nardetto, N.; Domiciano de Souza, A.; Mourard, D.; Tallon-Bosc, I.; Aroui, H.; Farrington, C.; Ligi, R.; Meilland, A.; Mouelhi, M.

    2017-08-01

    Context. Rapid rotation is a common feature for massive stars, with important consequences on their physical structure, flux distribution and evolution. Fast-rotating stars are flattened and show gravity darkening (non-uniform surface intensity distribution). Another important and less studied impact of fast-rotation in early-type stars is its influence on the surface brightness colour relation (hereafter SBCR), which could be used to derive the distance of eclipsing binaries. Aims: The purpose of this paper is to determine the flattening of the fast-rotating B-type star δ Per using visible long-baseline interferometry. A second goal is to evaluate the impact of rotation and gravity darkening on the V - K colour and surface brightness of the star. Methods: The B-type star δ Per was observed with the VEGA/CHARA interferometer, which can measure spatial resolutions down to 0.3 mas and spectral resolving power of 5000 in the visible. We first used a toy model to derive the position angle of the rotation axis of the star in the plane of the sky. Then we used a code of stellar rotation, CHARRON, in order to derive the physical parameters of the star. Finally, by considering two cases, a static reference star and our best model of δ Per, we can quantify the impact of fast rotation on the surface brightness colour relation (SBCR). Results: We find a position angle of 23 ± 6 degrees. The polar axis angular diameter of δ Per is θp = 0.544 ± 0.007 mas, and the derived flatness is r = 1.121 ± 0.013. We derive an inclination angle for the star of I = 85+ 5-20 degrees and a projected rotation velocity Vsini = 175+ 8-11 km s-1 (or 57% of the critical velocity). We find also that the rotation and inclination angle of δ Per keeps the V - K colour unchanged while it decreasing its surface-brightness by about 0.05 mag. Conclusions: Correcting the impact of rotation on the SBCR of early-type stars appears feasible using visible interferometry and dedicated models.

  20. Effect of target color and scanning geometry on terrestrial LiDAR point-cloud noise and plane fitting

    Science.gov (United States)

    Bolkas, Dimitrios; Martinez, Aaron

    2018-01-01

    Point-cloud coordinate information derived from terrestrial Light Detection And Ranging (LiDAR) is important for several applications in surveying and civil engineering. Plane fitting and segmentation of target-surfaces is an important step in several applications such as in the monitoring of structures. Reliable parametric modeling and segmentation relies on the underlying quality of the point-cloud. Therefore, understanding how point-cloud errors affect fitting of planes and segmentation is important. Point-cloud intensity, which accompanies the point-cloud data, often goes hand-in-hand with point-cloud noise. This study uses industrial particle boards painted with eight different colors (black, white, grey, red, green, blue, brown, and yellow) and two different sheens (flat and semi-gloss) to explore how noise and plane residuals vary with scanning geometry (i.e., distance and incidence angle) and target-color. Results show that darker colors, such as black and brown, can produce point clouds that are several times noisier than bright targets, such as white. In addition, semi-gloss targets manage to reduce noise in dark targets by about 2-3 times. The study of plane residuals with scanning geometry reveals that, in many of the cases tested, residuals decrease with increasing incidence angles, which can assist in understanding the distribution of plane residuals in a dataset. Finally, a scheme is developed to derive survey guidelines based on the data collected in this experiment. Three examples demonstrate that users should consider instrument specification, required precision of plane residuals, required point-spacing, target-color, and target-sheen, when selecting scanning locations. Outcomes of this study can aid users to select appropriate instrumentation and improve planning of terrestrial LiDAR data-acquisition.

  1. Absolute calibration of brightness temperature of the Venus disk observed by the Longwave Infrared Camera onboard Akatsuki

    Science.gov (United States)

    Fukuhara, Tetsuya; Taguchi, Makoto; Imamura, Takeshi; Hayashitani, Akane; Yamada, Takeru; Futaguchi, Masahiko; Kouyama, Toru; Sato, Takao M.; Takamura, Mao; Iwagami, Naomoto; Nakamura, Masato; Suzuki, Makoto; Ueno, Munetaka; Hashimoto, George L.; Sato, Mitsuteru; Takagi, Seiko; Yamazaki, Atsushi; Yamada, Manabu; Murakami, Shin-ya; Yamamoto, Yukio; Ogohara, Kazunori; Ando, Hiroki; Sugiyama, Ko-ichiro; Kashimura, Hiroki; Ohtsuki, Shoko; Ishii, Nobuaki; Abe, Takumi; Satoh, Takehiko; Hirose, Chikako; Hirata, Naru

    2017-10-01

    The Venus Climate Orbiter Akatsuki arrived at Venus in December 2015, and the Longwave Infrared Camera (LIR) onboard the spacecraft started making observations. LIR has acquired more than 8000 images during the first two Venusian years since orbit insertion without any serious faults. However, brightness temperature derived from LIR images contained an unexpected bias that related not to natural phenomena but to a thermal condition of the instrument. The bias could be partially eliminated by keeping the power supply unit for LIR always active, while the residual bias was simply correlated with the baffle temperature. Therefore, deep-space images were acquired at different baffle temperatures on orbit, and a reference table for eliminating the bias from images was prepared. In the corrected images, the brightness temperature was 230 K at the center of the Venus disk, where the effect of limb darkening is negligible. The result is independent of the baffle temperature and consistent with the results of previous studies. Later, a laboratory experiment with the proto model of LIR showed that when the germanium (Ge) lens was heated, its actual temperature was slightly higher than the temperature measured by a thermal sensor attached to the lens holder. The experiment confirmed that transitory baffle heating accounted for the background bias found in the brightness temperature observed by LIR.[Figure not available: see fulltext.

  2. Limitations of the Oriented Difference of Gaussian Filter in Special Cases of Brightness Perception Illusions.

    Science.gov (United States)

    Bakshi, Ashish; Roy, Sourya; Mallick, Arijit; Ghosh, Kuntal

    2016-03-01

    The Oriented Difference of Gaussian (ODOG) filter of Blakeslee and McCourt has been successfully employed to explain several brightness perception illusions which include illusions of both brightness-contrast type, for example, Simultaneous Brightness Contrast and Grating Induction and the brightness-assimilation type, for example, the White effect and the shifted White effect. Here, we demonstrate some limitations of the ODOG filter in predicting perceived brightness by comparing the ODOG responses to various stimuli (generated by varying two parameters, namely, test patch length and spatial frequency) with experimental observations of the same. © The Author(s) 2015.

  3. Ultra-high resolution and high-brightness AMOLED

    Science.gov (United States)

    Wacyk, Ihor; Ghosh, Amal; Prache, Olivier; Draper, Russ; Fellowes, Dave

    2012-06-01

    As part of its continuing effort to improve both the resolution and optical performance of AMOLED microdisplays, eMagin has recently developed an SXGA (1280×3×1024) microdisplay under a US Army RDECOM CERDEC NVESD contract that combines the world's smallest OLED pixel pitch with an ultra-high brightness green OLED emitter. This development is aimed at next-generation HMD systems with "see-through" and daylight imaging requirements. The OLED pixel array is built on a 0.18-micron CMOS backplane and contains over 4 million individually addressable pixels with a pixel pitch of 2.7 × 8.1 microns, resulting in an active area of 0.52 inches diagonal. Using both spatial and temporal enhancement, the display can provide over 10-bits of gray-level control for high dynamic range applications. The new pixel design also enables the future implementation of a full-color QSXGA (2560 × RGB × 2048) microdisplay in an active area of only 1.05 inch diagonal. A low-power serialized low-voltage-differential-signaling (LVDS) interface is integrated into the display for use as a remote video link for tethered systems. The new SXGA backplane has been combined with the high-brightness green OLED device developed by eMagin under an NVESD contract. This OLED device has produced an output brightness of more than 8000fL with all pixels on; lifetime measurements are currently underway and will presented at the meeting. This paper will describe the operational features and first optical and electrical test results of the new SXGA demonstrator microdisplay.

  4. Flux and brightness calculations for various synchrotron radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Weber, J.M.; Hulbert, S.L.

    1991-11-01

    Synchrotron radiation (SR) storage rings are powerful scientific and technological tools. The first generation of storage rings in the US., e.g., SURF (Washington, D.C.), Tantalus (Wisconsin), SSRL (Stanford), and CHESS (Cornell), revolutionized VUV, soft X-ray, and hard X-ray science. The second (present) generation of storage rings, e.g. the NSLS VUV and XRAY rings and Aladdin (Wisconsin), have sustained the revolution by providing higher stored currents and up to a factor of ten smaller electron beam sizes than the first generation sources. This has made possible a large number of experiments that could not performed using first generation sources. In addition, the NSLS XRAY ring design optimizes the performance of wigglers (high field periodic magnetic insertion devices). The third generation storage rings, e.g. ALS (Berkeley) and APS (Argonne), are being designed to optimize the performance of undulators (low field periodic magnetic insertion devices). These extremely high brightness sources will further revolutionize x-ray science by providing diffraction-limited x-ray beams. The output of undulators and wigglers is distinct from that of bending magnets in magnitude, spectral shape, and in spatial and angular size. Using published equations, we have developed computer programs to calculate the flux, central intensity, and brightness output bending magnets and selected wigglers and undulators of the NSLS VUV and XRAY rings, the Advanced Light Source (ALS), and the Advanced Photon Source (APS). Following is a summary of the equations used, the graphs and data produced, and the computer codes written. These codes, written in the C programming language, can be used to calculate the flux, central intensity, and brightness curves for bending magnets and insertion devices on any storage ring.

  5. Beyond pragmatism: defending the 'bright line' of birth.

    Science.gov (United States)

    Burin, Achas K

    2014-01-01

    It is usually accepted by ethicists that birth does not alter moral status. Rather, it is thought that the rule according full legal rights at birth is pragmatic. Pragmatic reasoning is vulnerable to competing practical concerns and stronger moral principles. This 'bright line' has therefore been criticised both by those who believe personhood begins before birth and those who believe it begins afterward. In particular, a recent article by Giubilini and Minerva puts forward both pragmatic and moral arguments in favour of permitting infanticide, and the New South Wales Court of Criminal Appeal has suggested there is a strong case for abandoning the bright line (R v Iby (2005) 63 NSWLR 278). If we desire to defend current legal doctrine against such criticism, a medical and philosophical basis for the law should be articulated. This article suggests such a medical and philosophical basis. It argues that both the multiplicity of biological changes occurring in the neonate at birth and the extrauterine context (the world) provide a justification for the distinction drawn at law between abortion and infanticide. With reference to Robert Nozick's 'experience machine' thought-experiment and elements of phenomenological philosophy, it advances two propositions to explain the status-changing nature of the neonate's emergence out of the womb. First, that expressing sentience in the world is essential for the attainment of personhood. Second, that having become a person, the harm in killing is disruption of this engagement with the world and the reduction from personhood to non-existence. This is the distinction between a neonate's death and the termination of a foetus, underscoring the qualitative difference between the two sides of the bright line drawn in law. © The Author [2014]. Published by Oxford University Press; all rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. The new World Atlas of Artificial Sky Brightness

    Science.gov (United States)

    Falchi, Fabio; Cinzano, Pierantonio; Kyba, Christopher C. M.; Portnov, Boris A.

    2015-08-01

    I present the main steps toward the completion of the new World Atlas of Artificial Sky Brightness (WA II) and some results. The computational technique has been updated, in comparison to the first World Atlas, to take into account both sources and sites elevation. The elevation data are from USGS GTOPO30 global digital elevation model, with the same pixel size as the WA II maps. The upward emission function used to compute the Atlas is a three parameters function. The parameters can be constrained to the database of Earth based night sky brightness measurements. In this way we can use the better fitting upward function for the final map’s calibration. We maintained constant atmosphere parameters over the entire Earth, identical to those used for the first Atlas (Garstang atmospheric clarity coefficient k=1, equivalent to a vertical extinction at sea level of 0.33 magnitude in the V band). This was done in order to avoid introducing a local bias due to different conditions that may confound the light pollution propagation effects. The radiance data used are those from Visible Infrared Imaging Radiometer Suite (VIIRS) Day-Night Band (DNB) on board the Suomi NPP satellite. The use of this newly available radiance data allows for an increased real resolution, even while maintaining the same 30"x30" lat-lon pixel size. Anyway, a higher resolution is really appreciable only in the immediate proximity of sources of light pollution (e.g. inside a big city). The VIIRS DNB data used for the input data were chosen from the months ranging from May to September in order to avoid introducing bias from the variable snow coverage in mid to high northern latitudes. In the southern hemisphere this problem is far less pronounced. The WA II takes advantage of the now enormous database of Earth based sky brightness measurements obtained mainly with Sky Quality Meters, but also with CCD measurements.

  7. Variation reduction of brightness and pH of pulp sent to a paper mill

    Directory of Open Access Journals (Sweden)

    Napassavong Rojanarowan

    2015-03-01

    Full Text Available The variance of the brightness of pulp sent to the paper mill during the changing period of dry pulp grades affects the chemical control in the paper mill. This research aims to determine the mixing formula of pulp with different brightness from the EOP and D1 stages to handle this variation issue. This research uses response surface design with Central Composite Design type, regression technique and optimization technique to find the optimal setting of the mixing formula for each of the seven brightness levels to obtain the target brightness of 86% and the pH of 5.25. The mixing formulas are determined by the pulp mixing percentage and the sulfuric acid consumption. The experimental results reveal that when using higher EOP mixing ratio, the brightness decreases and the pH increases. Regarding the effect of the sulfuric acid, increasing the sulfuric acid makes the brightness and the pH decrease. After implementing the optimal formula in the production line, the mean of pulp brightness is closer to the target compared with the brightness before improvement and the brightness variation decreases without affecting the quality of other pulp grades, average of brightness decreased from 87.4% to 86.3% and standard deviation of brightness decreased from 1.09 to 0.46.

  8. Technological Challenges for High-Brightness Photo-Injectors

    CERN Multimedia

    Suberlucq, Guy

    2004-01-01

    Many applications, from linear colliders to free-electron lasers, passing through light sources and many other electron sources, require high brightness electron beams, usually produced by photo-injectors. Because certain parameters of these applications differ by several orders of magnitude, various solutions were implemented for the design and construction of the three main parts of the photo-injectors: lasers, photocathodes and guns. This paper summarizes the different requirements, how they lead to technological challenges and how R&D programs try to overcome these challenges. Some examples of state-of-the-art parts are presented.

  9. Aqueous origins of bright salt deposits on Ceres

    Science.gov (United States)

    Zolotov, Mikhail Yu.

    2017-11-01

    Bright materials have been reported in association with impact craters on Ceres. The abundant Na2CO3 and some ammonium salts, NH4HCO3 and/or NH4Cl, were detected in bright deposits within Occator crater with Dawn near infrared spectroscopy. The composition and appearance of the salts suggest their aqueous mobilization and emplacement after formation of the crater. Here we consider origins of the bright deposits through calculation of speciation in the H-C-N-O-Na-Cl water-salt type system constrained by the mass balance of observed salts. Calculations of chemical equilibria show that initial solutions had the pH of ∼10. The temperature and salinity of solutions could have not exceeded ∼273 K and ∼100 g per kg H2O, respectively. Freezing models reveal an early precipitation of Na2CO3·10H2O followed by minor NaHCO3. Ammonium salts precipitate near eutectic from brines enriched in NH4+, Cl- and Na+. A late-stage precipitation of NaCl·2H2O is modeled for solution compositions with added NaCl. Calculated eutectics are above 247 K. The apparently unabundant ammonium and chloride salts in Occator's deposits imply a rapid emplacement without a compositional evolution of solution. Salty ice grains could have deposited from post-impact ballistic plumes formed through low-pressure boiling of subsurface solutions. Hydrated and ammonium salts are unstable at maximum temperatures of Ceres' surface and could decompose through space weathering. Occator's ice-free salt deposits formed through a post-depositional sublimation of ice followed by dehydration of Na2CO3·10H2O and NaHCO3 to Na2CO3. In other regions, excavated and exposed bright materials could be salts initially deposited from plumes and accumulated at depth via post-impact boiling. The lack of detection of sulfates and an elevated carbonate/chloride ratio in Ceres' materials suggest an involvement of compounds abundant in the outer solar system.

  10. Bright X-ray transient in the LMC

    Science.gov (United States)

    Saxton, R.; Read, A. M.; Li, D. Y.

    2018-01-01

    We report a bright X-ray transient in the LMC from an XMM-Newton slew made on 5th January 2018. The source, XMMSL2 J053629.4-675940, had a soft X-ray (0.2-2 keV) count rate in the EPIC-pn detector, medium filter of 1.82+/-0.56 c/s, equivalent to a flux Fx=2.3+/-0.7E-12 ergs/s/cm2 for a nominal spectrum of a power-law of slope 2 absorbed by a column NH=3E20 cm^-2.

  11. Thin Sea-ice Thickness Retrievals from SMAP Brightness Temperatures

    Science.gov (United States)

    Bayler, E. J.; Smith, R.

    2016-12-01

    The retrieval of thin sea-ice thicknesses has been developed for data from the European Space Agency's Soil Moisture - Ocean Salinity (SMOS) mission, employing the transition of observed surface emissivity from open water to thick sea ice. This technique is now applied to brightness temperature data from NASA's Soil Moisture Active-Passive (SMAP) mission, addressing the instrument differences between the SMOS Microwave Imaging Radiometer using Aperture Synthesis (MIRAS) and the SMAP scanning radiometer. This study demonstrates the utility of SMAP data for addressing a critical data gap for numerical prediction in polar regions, particularly as operational modeling advances toward coupled ocean-atmosphere-cryosphere modeling.

  12. Relative Critical Points

    Directory of Open Access Journals (Sweden)

    Debra Lewis

    2013-05-01

    Full Text Available Relative equilibria of Lagrangian and Hamiltonian systems with symmetry are critical points of appropriate scalar functions parametrized by the Lie algebra (or its dual of the symmetry group. Setting aside the structures – symplectic, Poisson, or variational – generating dynamical systems from such functions highlights the common features of their construction and analysis, and supports the construction of analogous functions in non-Hamiltonian settings. If the symmetry group is nonabelian, the functions are invariant only with respect to the isotropy subgroup of the given parameter value. Replacing the parametrized family of functions with a single function on the product manifold and extending the action using the (coadjoint action on the algebra or its dual yields a fully invariant function. An invariant map can be used to reverse the usual perspective: rather than selecting a parametrized family of functions and finding their critical points, conditions under which functions will be critical on specific orbits, typically distinguished by isotropy class, can be derived. This strategy is illustrated using several well-known mechanical systems – the Lagrange top, the double spherical pendulum, the free rigid body, and the Riemann ellipsoids – and generalizations of these systems.

  13. Unveiling the Low Surface Brightness Stellar Peripheries of Galaxies

    Science.gov (United States)

    Ferguson, Annette M. N.

    2018-01-01

    The low surface brightness peripheral regions of galaxies contain a gold mine of information about how minor mergers and accretions have influenced their evolution over cosmic time. Enormous stellar envelopes and copious amounts of faint tidal debris are natural outcomes of the hierarchical assembly process and the search for and study of these features, albeit highly challenging, offers the potential for unrivalled insight into the mechanisms of galaxy growth. Over the last two decades, there has been burgeoning interest in probing galaxy outskirts using resolved stellar populations. Wide-field surveys have uncovered vast tidal debris features and new populations of very remote globular clusters, while deep Hubble Space Telescope photometry has provided exquisite star formation histories back to the earliest epochs. I will highlight some recent results from studies within and beyond the Local Group and conclude by briefly discussing the great potential of future facilities, such as JWST, Euclid, LSST and WFIRST, for major breakthroughs in low surface brightness galaxy periphery science.

  14. Observations of Bright Massive Stars Using Small Size Telescopes

    Science.gov (United States)

    Beradze, Sopia; Kochiashvili, Nino

    2017-11-01

    The size of a telescope determines goals and objects of observations. During the latest decades it becomes more and more difficult to get photometric data of bright stars because most of telescopes of small sizes do not operate already. But there are rather interesting questions connected to the properties and evolution ties between different types of massive stars. Multi-wavelength photometric data are needed for solution of some of them. We are presenting our observational plans of bright Massive X-ray binaries, WR and LBV stars using a small size telescope. All these stars, which are presented in the poster are observational targets of Sopia Beradze's future PhD thesis. We already have got very interesting results on the reddening and possible future eruption of the massive hypergiant star P Cygni. Therefore, we decided to choose some additional interesting massive stars of different type for future observations. All Massive stars play an important role in the chemical evolution of galaxies because of they have very high mass loss - up to 10-4M⊙/a year. Our targets are on different evolutionary stages and three of them are the members of massive binaries. We plan to do UBVRI photometric observations of these stars using the 48 cm Cassegrain telescope of the Abastumani Astrophisical Observatory.

  15. Lightness and brightness judgments of coplanar retinally noncontiguous surfaces.

    Science.gov (United States)

    Schirillo, J A; Shevell, S K

    1993-12-01

    Several experiments reveal that judgments of lightness and brightness of an achromatic surface depend, in part, on the luminances of other surfaces perceived to share the same depth plane, even if the surfaces are well separated on the retina. Two Mondrians, simulated on a CRT, were viewed through a haploscope. The more highly illuminated Mondrian contained a comparison patch and appeared nearer than the more dimly illuminated Mondrian, which contained the test patch. By independently varying the disparity of the test patch, observers could make the test patch appear to be in the depth plane of either the dimly or the highly illuminated Mondrian. Observers set the luminance of the test patch to match that of the comparison patch. The test was set as high as 15% more luminous when it was perceived in the depth plane of the highly illuminated rather than the dimly illuminated Mondrian. Both brightness and lightness judgments were affected by the perceived depth of the test, although the lightness judgments of inexperienced observers sometimes were dominated by local-contrast matching.

  16. Bright Solitons in a PT-Symmetric Chain of Dimers

    Directory of Open Access Journals (Sweden)

    Omar B. Kirikchi

    2016-01-01

    Full Text Available We study the existence and stability of fundamental bright discrete solitons in a parity-time- (PT- symmetric coupler composed by a chain of dimers that is modelled by linearly coupled discrete nonlinear Schrödinger equations with gain and loss terms. We use a perturbation theory for small coupling between the lattices to perform the analysis, which is then confirmed by numerical calculations. Such analysis is based on the concept of the so-called anticontinuum limit approach. We consider the fundamental onsite and intersite bright solitons. Each solution has symmetric and antisymmetric configurations between the arms. The stability of the solutions is then determined by solving the corresponding eigenvalue problem. We obtain that both symmetric and antisymmetric onsite mode can be stable for small coupling, in contrast to the reported continuum limit where the antisymmetric solutions are always unstable. The instability is either due to the internal modes crossing the origin or the appearance of a quartet of complex eigenvalues. In general, the gain-loss term can be considered parasitic as it reduces the stability region of the onsite solitons. Additionally, we analyse the dynamic behaviour of the onsite and intersite solitons when unstable, where typically it is either in the form of travelling solitons or soliton blow-ups.

  17. Bright PanSTARRS Nuclear Transients – what are they?

    Directory of Open Access Journals (Sweden)

    Smartt S.

    2012-12-01

    Full Text Available We present an initial analysis of 49 bright transients occurring in the nuclei of galaxies with no previous known Active Galactic Nucleus (AGN. They have been discovered as part of the PanSTARRs 3π survey, and followed up with the Liverpool Telescope. Based on colours, light curve shape, and a small number with optical spectra, these transients seem to fall into three groups. Red/fast transients are nuclear supernovae of various types. Some bright nuclear transients are blue and decay on a timescale of a few months; these may be candidates for tidal disruption events. However most of the events we have found are blue and are either still rising or decaying slowly, on a timescale of years; the few spectra we have show AGN at z ∼ 1. We argue that these transients are background AGN microlensed by stars in foreground galaxies by a factor 10–100. Monitoring such events gives us very promising prospects for measuring the structure of AGN and so testing current theories.

  18. Airborne Light Detection and Ranging (lidar) Derived Deformation from the MW 6.0 24 August, 2014 South Napa Earthquake Estimated by Two and Three Dimensional Point Cloud Change Detection Techniques

    Science.gov (United States)

    Lyda, A. W.; Zhang, X.; Glennie, C. L.; Hudnut, K.; Brooks, B. A.

    2016-06-01

    Remote sensing via LiDAR (Light Detection And Ranging) has proven extremely useful in both Earth science and hazard related studies. Surveys taken before and after an earthquake for example, can provide decimeter-level, 3D near-field estimates of land deformation that offer better spatial coverage of the near field rupture zone than other geodetic methods (e.g., InSAR, GNSS, or alignment array). In this study, we compare and contrast estimates of deformation obtained from different pre and post-event airborne laser scanning (ALS) data sets of the 2014 South Napa Earthquake using two change detection algorithms, Iterative Control Point (ICP) and Particle Image Velocimetry (PIV). The ICP algorithm is a closest point based registration algorithm that can iteratively acquire three dimensional deformations from airborne LiDAR data sets. By employing a newly proposed partition scheme, "moving window," to handle the large spatial scale point cloud over the earthquake rupture area, the ICP process applies a rigid registration of data sets within an overlapped window to enhance the change detection results of the local, spatially varying surface deformation near-fault. The other algorithm, PIV, is a well-established, two dimensional image co-registration and correlation technique developed in fluid mechanics research and later applied to geotechnical studies. Adapted here for an earthquake with little vertical movement, the 3D point cloud is interpolated into a 2D DTM image and horizontal deformation is determined by assessing the cross-correlation of interrogation areas within the images to find the most likely deformation between two areas. Both the PIV process and the ICP algorithm are further benefited by a presented, novel use of urban geodetic markers. Analogous to the persistent scatterer technique employed with differential radar observations, this new LiDAR application exploits a classified point cloud dataset to assist the change detection algorithms. Ground

  19. AIRBORNE LIGHT DETECTION AND RANGING (LIDAR DERIVED DEFORMATION FROM THE MW 6.0 24 AUGUST, 2014 SOUTH NAPA EARTHQUAKE ESTIMATED BY TWO AND THREE DIMENSIONAL POINT CLOUD CHANGE DETECTION TECHNIQUES

    Directory of Open Access Journals (Sweden)

    A. W. Lyda

    2016-06-01

    Full Text Available Remote sensing via LiDAR (Light Detection And Ranging has proven extremely useful in both Earth science and hazard related studies. Surveys taken before and after an earthquake for example, can provide decimeter-level, 3D near-field estimates of land deformation that offer better spatial coverage of the near field rupture zone than other geodetic methods (e.g., InSAR, GNSS, or alignment array. In this study, we compare and contrast estimates of deformation obtained from different pre and post-event airborne laser scanning (ALS data sets of the 2014 South Napa Earthquake using two change detection algorithms, Iterative Control Point (ICP and Particle Image Velocimetry (PIV. The ICP algorithm is a closest point based registration algorithm that can iteratively acquire three dimensional deformations from airborne LiDAR data sets. By employing a newly proposed partition scheme, “moving window,” to handle the large spatial scale point cloud over the earthquake rupture area, the ICP process applies a rigid registration of data sets within an overlapped window to enhance the change detection results of the local, spatially varying surface deformation near-fault. The other algorithm, PIV, is a well-established, two dimensional image co-registration and correlation technique developed in fluid mechanics research and later applied to geotechnical studies. Adapted here for an earthquake with little vertical movement, the 3D point cloud is interpolated into a 2D DTM image and horizontal deformation is determined by assessing the cross-correlation of interrogation areas within the images to find the most likely deformation between two areas. Both the PIV process and the ICP algorithm are further benefited by a presented, novel use of urban geodetic markers. Analogous to the persistent scatterer technique employed with differential radar observations, this new LiDAR application exploits a classified point cloud dataset to assist the change detection

  20. Characterization of MIPAS elevation pointing

    Directory of Open Access Journals (Sweden)

    M. Kiefer

    2007-01-01

    Full Text Available Sufficient knowledge of the pointing is essential for analyses of limb emission measurements. The scientific retrieval processor for MIPAS on ENVISAT operated at IMK allows the retrieval of pointing information in terms of tangent altitudes along with temperature. The retrieved tangent altitudes are independent of systematic offsets in the engineering Line-Of-Sight (LOS information delivered with the ESA Level 1b product. The difference of pointing retrieved from the reprocessed high resolution MIPAS spectra and the engineering pointing information was examined with respect to spatial/temporal behaviour. Among others the following characteristics of MIPAS pointing could be identified: Generally the engineering tangent altitudes are too high by 0–1.8 km with conspicuous variations in this range over time. Prior to December of 2003 there was a drift of about 50–100 m/h, which was due to a slow change in the satellite attitude. A correction of this attitude is done twice a day, which leads to discontinuities in the order of 1–1.5 km in the tangent altitudes. Occasionally discontinuities up to 2.5 km are found, as already reported from MIPAS and SCIAMACHY observations. After an update of the orbit position software in December 2003 values of drift and jumps are much reduced. There is a systematic difference in the mispointing between the poles which amounts to 1.5–2 km, i.e. there is a conspicuous orbit-periodic feature. The analysis of the correlation between the instrument's viewing angle azimuth and differential mispointing supports the hypotheses that a major part of this latter phenomenon can be attributed to an error in the roll angle of the satellite/instrument system of approximately 42 mdeg. One conclusion is that ESA level 2 data should be compared to other data exclusively on tangent pressure levels. Complementary to IMK data, ESA operational LOS calibration results were used to characterize MIPAS pointing. For this purpose

  1. Very deep spectroscopy of the bright Saturn nebula NGC 7009 - II. Analysis of the rich optical recombination spectrum

    Science.gov (United States)

    Fang, X.; Liu, X.-W.

    2013-03-01

    In Paper I, we presented a deep, long-slit spectrum of the bright Saturn nebula NGC 7009. Numerous permitted lines emitted by the C+, N+, O+ and Ne+ ions were detected. Gaussian profile fitting to the spectrum yielded more than 1000 lines, the majority of which are optical recombination lines (ORLs) of heavy-element ions. In the current paper, we present a critical analysis of the rich optical recombination spectrum of NGC 7009, in the context of the bi-abundance nebular model proposed by Liu et al. Transitions from individual multiplets are checked carefully for potential blended lines. The observed relative intensities are compared with the theoretical predictions based on high-quality effective recombination coefficients, now available for the recombination line spectrum of a number of heavy-element ions. The possibility of plasma diagnostics using the ORLs of various heavy-element ions is discussed in detail. The line ratios that can be used to determine electron temperature are presented for each ion, although there is still a lack of adequate atomic data and some of the lines are still not detected in the spectrum of NGC 7009 due to weakness and/or line blending. Plasma diagnostics based on the N II and O II recombination spectra both yield electron temperatures close to 1000 K, which is lower than those derived from the collisionally excited line (CEL) ratios (e.g. the [O III] and [N II] nebular-to-auroral line ratios; see Paper I for details) by nearly one order of magnitude. The very low temperatures yielded by the O II and N II ORLs indicate that they originate from very cold regions. The C2+/H+, N2+/H+, O2+/H+ and Ne2+/H+ ionic abundance ratios derived from ORLs are consistently higher, by about a factor of 5, than the corresponding values derived from CELs. In calculating the ORL ionic abundance ratios, we have used the newly available high-quality effective recombination coefficients, and adopted an electron temperature of ˜1000 K, as given by the ORL

  2. Enhanced brightness of organic light-emitting diodes based on Mg:Ag cathode using alkali metal chlorides as an electron injection layer

    Energy Technology Data Exchange (ETDEWEB)

    Zou Ye [Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Deng Zhenbo, E-mail: zbdeng@bjtu.edu.cn [Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China); Xu Denghui [Department of Mathematics and Physics, Beijing Technology and Business University, Beijing 100037 (China); Lue Zhaoyue; Yin Yuehong; Du Hailiang; Chen Zheng; Wang Yongsheng [Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044 (China)

    2012-02-15

    Different thicknesses of cesium chloride (CsCl) and various alkali metal chlorides were inserted into organic light-emitting diodes (OLEDs) as electron injection layers (EILs). The basic structure of OLED is indium tin oxide (ITO)/N,N Prime -diphenyl-N,N Prime -bis(1-napthyl-phenyl)-1.1 Prime -biphenyl-4.4 Prime -diamine (NPB)/tris-(8-hydroxyquinoline) aluminum (Alq{sub 3})/Mg:Ag/Ag. The electroluminescent (EL) performance curves show that both the brightness and efficiency of the OLEDs can be obviously enhanced by using a thin alkali metal chloride layer as an EIL. The electron injection barrier height between the Alq{sub 3} layer and Mg:Ag cathode is reduced by inserting a thin alkali metal chloride as an EIL, which results in enhanced electron injection and electron current. Therefore, a better balance of hole and electron currents at the emissive interface is achieved and consequently the brightness and efficiency of OLEDs are improved. - Highlights: Black-Right-Pointing-Pointer Alkaline metal chlorides were used as electron injection layers in organic light-emitting diodes based on Mg:Ag cathode. Black-Right-Pointing-Pointer Brightness and efficiency of OLEDs with alkaline metal chlorides as electron injection layers were all greatly enhanced. Black-Right-Pointing-Pointer The Improved OLED performance was attributed to the possible interfacial chemical reaction. Black-Right-Pointing-Pointer Electron-only devices are fabricated to demonstrate the electron injection enhancement.

  3. Error sources in the retrieval of aerosol information over bright surfaces from satellite measurements in the oxygen A band

    Science.gov (United States)

    Nanda, Swadhin; de Graaf, Martin; Sneep, Maarten; de Haan, Johan F.; Stammes, Piet; Sanders, Abram F. J.; Tuinder, Olaf; Pepijn Veefkind, J.; Levelt, Pieternel F.

    2018-01-01

    Retrieving aerosol optical thickness and aerosol layer height over a bright surface from measured top-of-atmosphere reflectance spectrum in the oxygen A band is known to be challenging, often resulting in large errors. In certain atmospheric conditions and viewing geometries, a loss of sensitivity to aerosol optical thickness has been reported in the literature. This loss of sensitivity has been attributed to a phenomenon known as critical surface albedo regime, which is a range of surface albedos for which the top-of-atmosphere reflectance has minimal sensitivity to aerosol optical thickness. This paper extends the concept of critical surface albedo for aerosol layer height retrievals in the oxygen A band, and discusses its implications. The underlying physics are introduced by analysing the top-of-atmosphere reflectance spectrum as a sum of atmospheric path contribution and surface contribution, obtained using a radiative transfer model. Furthermore, error analysis of an aerosol layer height retrieval algorithm is conducted over dark and bright surfaces to show the dependence on surface reflectance. The analysis shows that the derivative with respect to aerosol layer height of the atmospheric path contribution to the top-of-atmosphere reflectance is opposite in sign to that of the surface contribution - an increase in surface brightness results in a decrease in information content. In the case of aerosol optical thickness, these derivatives are anti-correlated, leading to large retrieval errors in high surface albedo regimes. The consequence of this anti-correlation is demonstrated with measured spectra in the oxygen A band from the GOME-2 instrument on board the Metop-A satellite over the 2010 Russian wildfires incident.

  4. Herschel SPIRE fourier transform spectrometer: calibration of its bright-source mode

    Science.gov (United States)

    Lu, Nanyao; Polehampton, Edward T.; Swinyard, Bruce M.; Benielli, Dominique; Fulton, Trevor; Hopwood, Rosalind; Imhof, Peter; Lim, Tanya; Marchili, Nicola; Naylor, David A.; Schulz, Bernhard; Sidher, Sunil; Valtchanov, Ivan

    2014-07-01

    The Fourier Transform Spectrometer (FTS) of the Spectral and Photometric Imaging REceiver (SPIRE) on board the ESA Herschel Space Observatory has two detector setting modes: (a) a nominal mode, which is optimized for observing moderately bright to faint astronomical targets, and (b) a bright-source mode recommended for sources significantly brighter than 500 Jy, within the SPIRE FTS bandwidth of 446.7-1544 GHz (or 194-671 microns in wavelength), which employs a reduced detector responsivity and out-of-phase analog signal amplifier/demodulator. We address in detail the calibration issues unique to the bright-source mode, describe the integration of the bright-mode data processing into the existing pipeline for the nominal mode, and show that the flux calibration accuracy of the bright-source mode is generally within 2 % of that of the nominal mode, and that the bright-source mode is 3 to 4 times less sensitive than the nominal mode.

  5. Relating vanishing points to catadioptric camera calibration

    Science.gov (United States)

    Duan, Wenting; Zhang, Hui; Allinson, Nigel M.

    2013-01-01

    This paper presents the analysis and derivation of the geometric relation between vanishing points and camera parameters of central catadioptric camera systems. These vanishing points correspond to the three mutually orthogonal directions of 3D real world coordinate system (i.e. X, Y and Z axes). Compared to vanishing points (VPs) in the perspective projection, the advantages of VPs under central catadioptric projection are that there are normally two vanishing points for each set of parallel lines, since lines are projected to conics in the catadioptric image plane. Also, their vanishing points are usually located inside the image frame. We show that knowledge of the VPs corresponding to XYZ axes from a single image can lead to simple derivation of both intrinsic and extrinsic parameters of the central catadioptric system. This derived novel theory is demonstrated and tested on both synthetic and real data with respect to noise sensitivity.

  6. Bright Spots in X-pinch Plasmas at 6 MA

    Science.gov (United States)

    Sinars, D. B.; Ampleford, D. J.; Yu, E. P.; Jennings, C. A.; Cuneo, M. E.; Wenger, D. F.; Pikuz, S. A.; Shelkovenko, T. A.; Bland, S. N.; Chittenden, J. P.

    2008-11-01

    Bright, ˜1 μm, 10-100 ps x-ray sources with extreme plasma parameters are routinely created using X-pinch plasmas driven by 0.2 MA. Modeling suggests that even more extreme plasma parameters might be possible at higher current. We present data from the first 6 MA X-pinch experiments on the SATURN facility at Sandia National Laboratories. The mass required to pinch near peak current was surprisingly low (˜14 mg/cm vs. ˜3 mg/cm at 1 MA) and the smallest x-ray source measured was ˜60 μm in size. Following up on recent work by Pikuz et al. at 1 MA, experiments in September will use nested-array X-pinch implosions to improve the symmetry.

  7. Types and Distribution of Bright Materials in 4 Vesta

    Science.gov (United States)

    Mittlefehldt, D. W.; Li, Jian-Yang; Pieters, C. M.; De Sanctis, M. C.; Schroder, S. E.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.; Yingst, R. A.

    2012-01-01

    A strong case can be made that Vesta is the parent asteroid of the howardite, eucrite and diogenite (HED) meteorites [1]. As such, we have over a century of detailed sample analysis experience to call upon when formulating hypotheses regarding plausible lithologic diversity on Vesta. It thus came as a surprise when Dawn s Framing Camera (FC) first revealed distinctly localized materials of exceptionally low and high albedos, often closely associated. To understand the nature and origin of these materials, and how they inform us of the geological evolution of Vesta, task forces began their study. An initial step of the scientific endeavor is to develop a descriptive, non-genetic classification of objects to use as a basis for developing hypotheses and observational campaigns. Here we present a catalog of the types of light-toned deposits and their distribution across Vesta. A companion abstract [2] discusses possible origins of bright materials and the constraints they suggest for vestan geology.

  8. CCD Photometry of bright stars using objective wire mesh

    Energy Technology Data Exchange (ETDEWEB)

    Kamiński, Krzysztof; Zgórz, Marika [Astronomical Observatory Institute, Faculty of Physics, A. Mickiewicz University, Słoneczna 36, 60-286 Poznań (Poland); Schwarzenberg-Czerny, Aleksander, E-mail: chrisk@amu.edu.pl [Copernicus Astronomical Centre, ul. Bartycka 18, PL 00-716 Warsaw (Poland)

    2014-06-01

    Obtaining accurate photometry of bright stars from the ground remains problematic due to the danger of overexposing the target and/or the lack of suitable nearby comparison stars. The century-old method of using objective wire mesh to produce multiple stellar images seems promising for the precise CCD photometry of such stars. Furthermore, our tests on β Cep and its comparison star, differing by 5 mag, are very encouraging. Using a CCD camera and a 20 cm telescope with the objective covered by a plastic wire mesh, in poor weather conditions, we obtained differential photometry with a precision of 4.5 mmag per two minute exposure. Our technique is flexible and may be tuned to cover a range as big as 6-8 mag. We discuss the possibility of installing a wire mesh directly in the filter wheel.

  9. Broad band spectral energy distribution studies of Fermi bright blazars

    Energy Technology Data Exchange (ETDEWEB)

    Monte, C., E-mail: claudia.monte@ba.infn.i [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy); Dipartimento di Fisica ' M. Merlin' dell' Universita e del Politecnico, I-70126 Bari (Italy); Giommi, P.; Cavazzuti, E.; Gasparrini, D. [Agenzia Spaziale Italiana (ASI) Science Data Center I-00044 Frascati (Roma) (Italy); Raino, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, I-70126 Bari (Italy); Dipartimento di Fisica ' M. Merlin' dell' Universita e del Politecnico, I-70126 Bari (Italy); Fuhrmann, L.; Angelakis, E. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Villata, M.; Raiteri, C.M. [INAF, Osservatorio Astronomico di Torino, I-10025 Pino Torinese (Italy); Perri, M. [Agenzia Spaziale Italiana (ASI) Science Data Center I-00044 Frascati (Roma) (Italy); Richards, J. [California Institute of Technology, Pasadena, CA (United States)

    2011-02-21

    The Fermi Gamma-ray Space Telescope was successfully launched on June 11, 2008 and has already opened a new era for gamma-ray astronomy. The Large Area Telescope (LAT), the main instrument on board Fermi, presents a significant improvement in sensitivity over its predecessor EGRET, due to its large field of view and effective area, combined with its excellent timing capabilities. The preliminary results of the Spectral Energy Distribution Analysis performed on a sample of bright blazars are presented. For this study, the data from the first three months of data collection of Fermi have been used. The analysis is extended down to radio, mm, near-IR, optical, UV and X-ray bands and up to TeV energies based on unprecedented sample of simultaneous multi-wavelength observations by GASP-WEBT.

  10. Broad band spectral energy distribution studies of Fermi bright blazars

    Science.gov (United States)

    Monte, C.; Giommi, P.; Cavazzuti, E.; Gasparrini, D.; Rainò, S.; Fuhrmann, L.; Angelakis, E.; Villata, M.; Raiteri, C. M.; Perri, M.; Richards, J.

    2011-02-01

    The Fermi Gamma-ray Space Telescope was successfully launched on June 11, 2008 and has already opened a new era for gamma-ray astronomy. The Large Area Telescope (LAT), the main instrument on board Fermi, presents a significant improvement in sensitivity over its predecessor EGRET, due to its large field of view and effective area, combined with its excellent timing capabilities. The preliminary results of the Spectral Energy Distribution Analysis performed on a sample of bright blazars are presented. For this study, the data from the first three months of data collection of Fermi have been used. The analysis is extended down to radio, mm, near-IR, optical, UV and X-ray bands and up to TeV energies based on unprecedented sample of simultaneous multi-wavelength observations by GASP-WEBT.

  11. A complete sample of long bright Swift gamma ray bursts.

    Science.gov (United States)

    Tagliaferri, Gianpiero; Salvaterra, Ruben; Campana, Sergio; Covino, Stefano; D'Avanzo, Paolo; Fugazza, Dino; Ghirlanda, Giancarlo; Ghisellini, Gabriele; Melandri, Andrea; Nava, Lara; Sbarufatti, Boris; Vergani, Susanna

    2013-06-13

    Complete samples are the basis of any population study. To this end, we selected a complete subsample of Swift long bright gamma ray bursts (GRBs). The sample, made up of 58 bursts, was selected by considering bursts with favourable observing conditions for ground-based follow-up observations and with the 15-150 keV 1 s peak flux above a flux threshold of 2.6 photons cm(-2) s(-1). This sample has a redshift completeness level higher than 90 per cent. Using this complete sample, we investigate the properties of long GRBs and their evolution with cosmic time, focusing in particular on the GRB luminosity function, the prompt emission spectral-energy correlations and the nature of dark bursts.

  12. Investigation of fundamental limits to beam brightness available from photoinjectors

    Energy Technology Data Exchange (ETDEWEB)

    Bazarov, Ivan [Cornell Univ., Ithaca, NY (United States)

    2015-07-09

    The goal of this project was investigation of fundamental limits to beam brightness available from photoinjectors. This basic research in accelerator physics spanned over 5 years aiming to extend the fundamental understanding of high average current, low emittance sources of relativistic electrons based on photoemission guns, a necessary prerequisite for a new generation of coherent X-ray synchrotron radiation facilities based on continuous duty superconducting linacs. The program focused on two areas critical to making advances in the electron source performance: 1) the physics of photocathodes for the production of low emittance electrons and 2) control of space charge forces in the immediate vicinity to the cathode via 3D laser pulse shaping.

  13. Relationships between brightness of nighttime lights and population density

    Science.gov (United States)

    Naizhuo, Z.

    2012-12-01

    Brightness of nighttime lights has been proven to be a good proxy for socioeconomic and demographic statistics. Moreover, the satellite nighttime lights data have been used to spatially disaggregate amounts of gross domestic product (GDP), fossil fuel carbon dioxide emission, and electric power consumption (Ghosh et al., 2010; Oda and Maksyutov, 2011; Zhao et al., 2012). Spatial disaggregations were performed in these previous studies based on assumed linear relationships between digital number (DN) value of pixels in the nighttime light images and socioeconomic data. However, reliability of the linear relationships was never tested due to lack of relative high-spatial-resolution (equal to or finer than 1 km × 1 km) statistical data. With the similar assumption that brightness linearly correlates to population, Bharti et al. (2011) used nighttime light data as a proxy for population density and then developed a model about seasonal fluctuations of measles in West Africa. The Oak Ridge National Laboratory used sub-national census population data and high spatial resolution remotely-sensed-images to produce LandScan population raster datasets. The LandScan population datasets have 1 km × 1 km spatial resolution which is consistent with the spatial resolution of the nighttime light images. Therefore, in this study I selected 2008 LandScan population data as baseline reference data and the contiguous United State as study area. Relationships between DN value of pixels in the 2008 Defense Meteorological Satellite Program's Operational Linescan System (DMSP-OLS) stable light image and population density were established. Results showed that an exponential function can more accurately reflect the relationship between luminosity and population density than a linear function. Additionally, a certain number of saturated pixels with DN value of 63 exist in urban core areas. If directly using the exponential function to estimate the population density for the whole brightly

  14. LiDAR Point Cloud and Stereo Image Point Cloud Fusion

    Science.gov (United States)

    2013-09-01

    and tree health information, resulting in a complete model of the forest inventory . LiDAR collected point clouds and stereo-image-derived point...N. C., Pitt, D., & Woods, M. (2013). The utility of image-based point clouds for forest inventory : a comparison with airborne laser scanning

  15. Music for a Brighter World: Brightness Judgment Bias by Musical Emotion

    OpenAIRE

    Bhattacharya, Joydeep; Lindsen, Job P.

    2016-01-01

    A prevalent conceptual metaphor is the association of the concepts of good and evil with brightness and darkness, respectively. Music cognition, like metaphor, is possibly embodied, yet no study has addressed the question whether musical emotion can modulate brightness judgment in a metaphor consistent fashion. In three separate experiments, participants judged the brightness of a grey square that was presented after a short excerpt of emotional music. The results of Experiment 1 showed that ...

  16. Hemoglobin derivatives

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003371.htm Hemoglobin derivatives To use the sharing features on this page, please enable JavaScript. Hemoglobin derivatives are altered forms of hemoglobin . Hemoglobin is ...

  17. Suomi NPP ATMS Level 1B Brightness Temperature V1 (SNPPATMSL1B) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — The Advanced Technology Microwave Sounder (ATMS) Level 1B data files contain brightness temperature measurements along with ancillary spacecraft, instrument, and...

  18. Enhanced-Resolution SSM/I and AMSR-E Daily Polar Brightness Temperatures

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains enhanced-resolution brightness temperatures produced using the Scatterometer Image Reconstruction (SIR) algorithm developed by the Microwave...

  19. CLPX-Satellite: AMSR-E Brightness Temperature Grids, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes Aqua Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) passive microwave brightness temperatures gridded to the...

  20. CD56bright NK cells exhibit potent antitumor responses following IL-15 priming.

    Science.gov (United States)

    Wagner, Julia A; Rosario, Maximillian; Romee, Rizwan; Berrien-Elliott, Melissa M; Schneider, Stephanie E; Leong, Jeffrey W; Sullivan, Ryan P; Jewell, Brea A; Becker-Hapak, Michelle; Schappe, Timothy; Abdel-Latif, Sara; Ireland, Aaron R; Jaishankar, Devika; King, Justin A; Vij, Ravi; Clement, Dennis; Goodridge, Jodie; Malmberg, Karl-Johan; Wong, Hing C; Fehniger, Todd A

    2017-11-01

    NK cells, lymphocytes of the innate immune system, are important for defense against infectious pathogens and cancer. Classically, the CD56dim NK cell subset is thought to mediate antitumor responses, whereas the CD56bright subset is involved in immunomodulation. Here, we challenge this paradigm by demonstrating that brief priming with IL-15 markedly enhanced the antitumor response of CD56bright NK cells. Priming improved multiple CD56bright cell functions: degranulation, cytotoxicity, and cytokine production. Primed CD56bright cells from leukemia patients demonstrated enhanced responses to autologous blasts in vitro, and primed CD56bright cells controlled leukemia cells in vivo in a murine xenograft model. Primed CD56bright cells from multiple myeloma (MM) patients displayed superior responses to autologous myeloma targets, and furthermore, CD56bright NK cells from MM patients primed with the IL-15 receptor agonist ALT-803 in vivo displayed enhanced ex vivo functional responses to MM targets. Effector mechanisms contributing to IL-15-based priming included improved cytotoxic protein expression, target cell conjugation, and LFA-1-, CD2-, and NKG2D-dependent activation of NK cells. Finally, IL-15 robustly stimulated the PI3K/Akt/mTOR and MEK/ERK pathways in CD56bright compared with CD56dim NK cells, and blockade of these pathways attenuated antitumor responses. These findings identify CD56bright NK cells as potent antitumor effectors that warrant further investigation as a cancer immunotherapy.

  1. Enhanced-Resolution SSM/I and AMSR-E Daily Polar Brightness Temperatures, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains enhanced-resolution brightness temperatures produced using the Scatterometer Image Reconstruction (SIR) algorithm developed by the Microwave...

  2. The SAFE-T assessment tool: derivation and validation of a web-based application for point-of-care evaluation of gastroenterology fellow performance in colonoscopy.

    Science.gov (United States)

    Kumar, Navin L; Kugener, Guillaume; Perencevich, Molly L; Saltzman, John R

    2018-01-01

    Attending assessment is a critical part of endoscopic education for gastroenterology fellows. The aim of this study was to develop and validate a concise assessment tool to evaluate real-time fellow performance in colonoscopy administered via a web-based application. The Skill Assessment in Fellow Endoscopy Training (SAFE-T) tool was derived as a novel 5-question evaluation tool that captures both summative and formative feedback adapted into a web-based application. A prospective study of 15 gastroenterology fellows (5 fellows each from years 1 to 3 of training) was performed using the SAFE-T tool. An independent reviewer evaluated a subset of these procedures and completed the SAFE-T tool and Mayo Colonoscopy Skills Assessment Tool (MCSAT) for reliability testing. Twenty-six faculty completed 350 SAFE-T evaluations of the 15 fellows in the study. The mean SAFE-T overall score (year 1, 2.00; year 2, 3.84; year 3, 4.28) differentiated each sequential fellow year of training (P  0.90, P assessment tool, a concise and web-based means of assessing real-time gastroenterology fellow performance in colonoscopy. Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  3. Scattering properties of point dipole interactions

    DEFF Research Database (Denmark)

    Zolotaryuk, Alexander; Christiansen, Peter Leth; Iermakova, S.V.

    2006-01-01

    The scattering properties of a three-parameter family of point dipole-like interactions constructed from a sequence of barrier-well rectangles are studied in the zero-range limit. Besides the real (unrenormalized) delta'-interaction, the derivative of Dirac's delta function, a whole family of point...

  4. Very smooth points of spaces of operators

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    or Y has the compact metric approximation property (CMAP), then it is easy to see that K (X, Y ) ⊂ L(X, Y ) satisfies the above condition (see [R6]). Thus for a compact operator that is a very smooth point, directional derivatives exist in the direction of all bounded operators. Smooth points of operator spaces has been ...

  5. Controlling excitons. Concepts for phosphorescent organic LEDs at high brightness

    Energy Technology Data Exchange (ETDEWEB)

    Reineke, Sebastian

    2009-11-15

    This work focusses on the high brightness performance of phosphorescent organic light-emitting diodes (OLEDs). The use of phosphorescent emitter molecules in OLEDs is essential to realize internal electron-photon conversion efficiencies of 100 %. However, due to their molecular nature, the excited triplet states have orders of magnitude longer time constants compared to their fluorescent counterparts which, in turn, strongly increases the probability of bimolecular annihilation. As a consequence, the efficiencies of phosphorescent OLEDs decline at high brightness - an effect known as efficiency roll-off, for which it has been shown to be dominated by triplet-triplet annihilation (TTA). In this work, TTA of the archetype phosphorescent emitter Ir(ppy){sub 3} is investigated in time-resolved photoluminescence experiments. For the widely used mixed system CBP:Ir(ppy){sub 3}, host-guest TTA - an additional unwanted TTA channel - is experimentally observed at high excitation levels. By using matrix materials with higher triplet energies, this effect is efficiently suppressed, however further studies show that the efficiency roll-off of Ir(ppy)3 is much more pronounced than predicted by a model based on Foerster-type energy transfer, which marks the intrinsic limit for TTA. These results suggest that the emitter molecules show a strong tendency to form aggregates in the mixed film as the origin for enhanced TTA. Transmission electron microscopy images of Ir(ppy){sub 3} doped mixed films give direct proof of emitter aggregates. Based on these results, two concepts are developed that improve the high brightness performance of OLEDs. In a first approach, thin intrinsic matrix interlayers are incorporated in the emission layer leading to a one-dimensional exciton confinement that suppresses exciton migration and, consequently, TTA. The second concept reduces the efficiency roll-off by using an emitter molecule with slightly different chemical structure, i.e. Ir(ppy){sub 2

  6. Diviner lunar radiometer gridded brightness temperatures from geodesic binning of modeled fields of view

    Science.gov (United States)

    Sefton-Nash, E.; Williams, J.-P.; Greenhagen, B. T.; Aye, K.-M.; Paige, D. A.

    2017-12-01

    An approach is presented to efficiently produce high quality gridded data records from the large, global point-based dataset returned by the Diviner Lunar Radiometer Experiment aboard NASA's Lunar Reconnaissance Orbiter. The need to minimize data volume and processing time in production of science-ready map products is increasingly important with the growth in data volume of planetary datasets. Diviner makes on average >1400 observations per second of radiance that is reflected and emitted from the lunar surface, using 189 detectors divided into 9 spectral channels. Data management and processing bottlenecks are amplified by modeling every observation as a probability distribution function over the field of view, which can increase the required processing time by 2-3 orders of magnitude. Geometric corrections, such as projection of data points onto a digital elevation model, are numerically intensive and therefore it is desirable to perform them only once. Our approach reduces bottlenecks through parallel binning and efficient storage of a pre-processed database of observations. Database construction is via subdivision of a geodesic icosahedral grid, with a spatial resolution that can be tailored to suit the field of view of the observing instrument. Global geodesic grids with high spatial resolution are normally impractically memory intensive. We therefore demonstrate a minimum storage and highly parallel method to bin very large numbers of data points onto such a grid. A database of the pre-processed and binned points is then used for production of mapped data products that is significantly faster than if unprocessed points were used. We explore quality controls in the production of gridded data records by conditional interpolation, allowed only where data density is sufficient. The resultant effects on the spatial continuity and uncertainty in maps of lunar brightness temperatures is illustrated. We identify four binning regimes based on trades between the

  7. Development of a Chlamydia trachomatis vaccine for urogenital infections: novel tools and new strategies point to bright future prospects.

    Science.gov (United States)

    Hafner, Louise M; Timms, Peter

    2018-01-01

    The "cloaked" bacterial pathogen that is Chlamydia trachomatis continues to cause sexually transmitted infections (STIs) that adversely affect the health and well-being of children, adolescents and adults globally. The reproductive disease sequelae follow unresolved or untreated chronic or recurrent asymptomatic C.trachomatis infections of the lower female genital tract (FGT) and can include pelvic pain, pelvic inflammatory disease (PID) and ectopic pregnancy. Tubal Factor Infertility (TFI) can also occur since protective and long-term natural immunity to chlamydial infection is incomplete, allowing for ascension of the organism to the upper FGT. Developing countries including the WHO African (8.3 million cases) and South-East Asian regions (7.2 million cases) bear the highest burden of chlamydial STIs. Areas covered: Genetic advances for Chlamydia have provided tools for transformation (including dendrimer-enabled transformation), lateral gene transfer and chemical mutagenesis. Recent progress in these areas is reviewed with a focus on vaccine development for Chlamydia infections of the female genital tract. Expert commentary: A vaccine that can elicit immuno-protective responses whilst avoiding adverse immuno-pathologic host responses is required. The current technological advances in chlamydial genetics and proteomics, as well as novel and improved adjuvants and delivery systems, provide new hope that the elusive chlamydial vaccine is an imminent and realistic goal.

  8. Hi-C Observations of Penumbral Bright Dots

    Science.gov (United States)

    Alpert, S. E.; Tiwari, S. K.; Moore, R. L.; Savage, S. L.; Winebarger, A. R.

    2014-01-01

    We use high-quality data obtained by the High Resolution Coronal Imager (Hi-C) to examine bright dots (BDs) in a sunspot's penumbra. The sizes of these BDs are on the order of 1 arcsecond (1") and are therefore hard to identify using the Atmospheric Imaging Assembly's (AIA) 0.6" pixel(exp -1) resolution. These BD become readily apparent with Hi-C's 0.1" pixel(exp -1) resolution. Tian et al. (2014) found penumbral BDs in the transition region (TR) by using the Interface Region Imaging Spectrograph (IRIS). However, only a few of their dots could be associated with any enhanced brightness in AIA channels. In this work, we examine the characteristics of the penumbral BDs observed by Hi-C in a sunspot penumbra, including their sizes, lifetimes, speeds, and intensity. We also attempt to find any association of these BDs to the IRIS BDs. There are fewer Hi-C BDs in the penumbra than seen by IRIS, though different sunspots were studied. We use 193 Angstroms Hi-C data from July 11, 2012 which observed from approximately 18:52:00 UT- 18:56:00 UT and supplement it with data from AIA's 193 Angstrom passband to see the complete lifetime of the dots that were born before and/or lasted longer than Hi- C's 5-minute observation period. We use additional AIA passbands and compare the light curves of the BDs at different temperatures to test whether the Hi-C BDs are TR BDs. We find that most Hi-C BDs show clear movement, and of those that do, they move in a radial direction, toward or away from the sunspot umbra. Single BDs interact with other BDs, combining to fade away or brighten. The BDs that do not interact with other BDs tend to move less. Many of the properties of our BDs are similar to the extreme values of the IRIS BDs, e.g., they move slower on average and their sizes and lifetimes are on the higher end of the IRIS BDs. We infer that our penumbral BDs are the large-scale end of the distribution of BDs observed by IRIS.

  9. Testing the dark matter hypothesis with low surface brightness galaxies and other evidence

    NARCIS (Netherlands)

    McGaugh, SS; de Blok, WJG

    1998-01-01

    The severity of the mass discrepancy in spiral galaxies is strongly correlated with the central surface brightness of their disks. Progressively lower surface brightness galaxies have ever larger mass discrepancies. No other parameter (luminosity, size, velocity, morphology) is so well correlated

  10. T1 bright appendix sign to exclude acute appendicitis in pregnant women.

    Science.gov (United States)

    Shin, Ilah; An, Chansik; Lim, Joon Seok; Kim, Myeong-Jin; Chung, Yong Eun

    2017-08-01

    To evaluate the diagnostic value of the T1 bright appendix sign for the diagnosis of acute appendicitis in pregnant women. This retrospective study included 125 pregnant women with suspected appendicitis who underwent magnetic resonance (MR) imaging. The T1 bright appendix sign was defined as a high intensity signal filling more than half length of the appendix on T1-weighted imaging. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the T1 bright appendix sign for normal appendix identification were calculated in all patients and in those with borderline-sized appendices (6-7 mm). The T1 bright appendix sign was seen in 51% of patients with normal appendices, but only in 4.5% of patients with acute appendicitis. The overall sensitivity, specificity, PPV, and NPV of the T1 bright appendix sign for normal appendix diagnosis were 44.9%, 95.5%, 97.6%, and 30.0%, respectively. All four patients with borderline sized appendix with appendicitis showed negative T1 bright appendix sign. The T1 bright appendix sign is a specific finding for the diagnosis of a normal appendix in pregnant women with suspected acute appendicitis. • Magnetic resonance imaging is increasingly used in emergency settings. • Acute appendicitis is the most common cause of acute abdomen. • Magnetic resonance imaging is widely used in pregnant population. • T1 bright appendix sign can be a specific sign representing normal appendix.

  11. The dark and visible matter content of low surface brightness disc galaxies

    NARCIS (Netherlands)

    deBlok, WJG; McGaugh, SS

    1997-01-01

    We present mass models of a sample of 19 low surface brightness (LSB) galaxies and compare the properties of their constituent mass components with those of a sample of high surface brightness (HSB) galaxies. We find that LSB galaxies are dark matter dominated, Their halo parameters are only

  12. HI observations of low surface brightness galaxies : Probing low-density galaxies

    NARCIS (Netherlands)

    deBlok, WJG; McGaugh, SS; vanderHulst, JM

    1996-01-01

    We present Very Large Array (VLA) and Westerbork Synthesis Radio Telescope (WSRT) 21-cm HI observations of 19 late-type low surface brightness (LSB) galaxies. Our main findings are that these galaxies, as well as having low surface brightnesses, have low HI surface densities, about a factor of

  13. Functional magnetic resonance imaging of brightness induction in the human visual cortex

    NARCIS (Netherlands)

    Boucard, CC; van Es, JJ; Maguire, RP; Cornelissen, FW

    2005-01-01

    A grey surface on a bright background appears to be darker than the same surface on a dark background. We used functional magnetic resonance imaging to study this phenomenon called brightness induction. While being scanned, participants viewed centre-surround displays in which either centre or

  14. Bright morning light advances the human circadian system without affecting NREM sleep homeostasis

    NARCIS (Netherlands)

    Dijk, Derk Jan; Beersma, Domien G.M.; Daan, Serge; Lewy, Alfred J.

    Eight male subjects were exposed to either bright light or dim light between 0600 and 0900 h for 3 consecutive days each. Relative to the dim light condition, the bright light treatment advanced the evening rise in plasma melatonin and the time of sleep termination (sleep onset was held constant)

  15. Reduction of human sleep duration after bright light exposure in the morning

    NARCIS (Netherlands)

    Dijk, D.J.; Visscher, C.A.; Bloem, G.M.; Beersma, D.G.M.; Daan, S.

    1987-01-01

    In 8 subjects the spontaneous termination of sleep was determined after repetitive exposure to either bright or dim light, between 6:00 and 9:00 h, on 3 days preceding sleep assessment. Sleep duration was significantly shorter following bright light than following dim light. During sleep the time

  16. Inter-comparison of SMAP, SMOS and Aquarius L-band brightness temperature observations

    Science.gov (United States)

    Verifying the calibration of the SMAP radiometer over land observations is an important mission requirement. Inter-comparison of L-band brightness temperature observations from different satellites (SMAP, SMOS and Aquarius) is a useful tool for radiometer calibration. Brightness temperatures observa...

  17. Detection of cancerous masses in mammograms by template matching: optimization of template brightness distribution by means of evolutionary algorithm.

    Science.gov (United States)

    Bator, Marcin; Nieniewski, Mariusz

    2012-02-01

    Optimization of brightness distribution in the template used for detection of cancerous masses in mammograms by means of correlation coefficient is presented. This optimization is performed by the evolutionary algorithm using an auxiliary mass classifier. Brightness along the radius of the circularly symmetric template is coded indirectly by its second derivative. The fitness function is defined as the area under curve (AUC) of the receiver operating characteristic (ROC) for the mass classifier. The ROC and AUC are obtained for a teaching set of regions of interest (ROIs), for which it is known whether a ROI is true-positive (TP) or false-positive (F). The teaching set is obtained by running the mass detector using a template with a predetermined brightness. Subsequently, the evolutionary algorithm optimizes the template by classifying masses in the teaching set. The optimal template (OT) can be used for detection of masses in mammograms with unknown ROIs. The approach was tested on the training and testing sets of the Digital Database for Screening Mammography (DDSM). The free-response receiver operating characteristic (FROC) obtained with the new mass detector seems superior to the FROC for the hemispherical template (HT). Exemplary results are the following: in the case of the training set in the DDSM, the true-positive fraction (TPF) = 0.82 for the OT and 0.79 for the HT; in the case of the testing set, TPF = 0.79 for the OT and 0.72 for the HT. These values were obtained for disease cases, and the false-positive per image (FPI) = 2.

  18. Tracking of multiple points using color video image analyzer

    Science.gov (United States)

    Nennerfelt, Leif

    1990-08-01

    The Videomex-X is a new product intended for use in biomechanical measurement. It tracks up to six points at 60 frames per second using colored markers placed on the subject. The system can be used for applications such as gait analysis, studying facial movements, or tracking the pattern of movements of individuals in a group. The Videomex-X is comprised of a high speed color image analyzer, an RBG color video camera, an IBM AT compatible computer and motion analysis software. The markers are made from brightly colored plastic disks and each marker is a different color. Since the markers are unique, the problem of misidentification of markers does not occur. The Videomex-X performs realtime analysis so that the researcher can get immediate feedback on the subject's performance. High speed operation is possible because the system uses distributed processing. The image analyzer is a hardwired parallel image processor which identifies the markers within the video picture and computes their x-y locations. The image analyzer sends the x-y coordinates to the AT computer which performs additional analysis and presents the result. The x-y coordinate data acquired during the experiment may be streamed to the computer's hard disk. This allows the data to be re-analyzed repeatedly using different analysis criteria. The original Videomex-X tracked in two dimensions. However, a 3-D system has recently been completed. The algorithm used by the system to derive performance results from the x-y coordinates is contained in a separate ASCII file. These files can be modified by the operator to produce the required type of data reduction.

  19. High Brightness HDR Projection Using Dynamic Freeform Lensing

    KAUST Repository

    Damberg, Gerwin

    2016-05-03

    Cinema projectors need to compete with home theater displays in terms of image quality. High frame rate and spatial resolution as well as stereoscopic 3D are common features today, but even the most advanced cinema projectors lack in-scene contrast and, more important, high peak luminance, both of which are essential perceptual attributes of images appearing realistic. At the same time, HDR image statistics suggest that the average image intensity in a controlled ambient viewing environment such as the cinema can be as low as 1% for cinematic HDR content and not often higher than 18%, middle gray in photography. Traditional projection systems form images and colors by blocking the source light from a lamp, therefore attenuating between 99% and 82% of light, on average. This inefficient use of light poses significant challenges for achieving higher peak brightness levels. In this work, we propose a new projector architecture built around commercially available components, in which light can be steered to form images. The gain in system efficiency significantly reduces the total cost of ownership of a projector (fewer components and lower operating cost), and at the same time increases peak luminance and improves black level beyond what is practically achievable with incumbent projector technologies. At the heart of this computational display technology is a new projector hardware design using phase modulation in combination with a new optimization algorithm that is capable of on-the-fly computation of freeform lens surfaces. © 2016 ACM.

  20. Low Cost Lithography Tool for High Brightness LED Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Hawryluk; Emily True

    2012-06-30

    The objective of this activity was to address the need for improved manufacturing tools for LEDs. Improvements include lower cost (both capital equipment cost reductions and cost-ofownership reductions), better automation and better yields. To meet the DOE objective of $1- 2/kilolumen, it will be necessary to develop these highly automated manufacturing tools. Lithography is used extensively in the fabrication of high-brightness LEDs, but the tools used to date are not scalable to high-volume manufacturing. This activity addressed the LED lithography process. During R&D and low volume manufacturing, most LED companies use contact-printers. However, several industries have shown that these printers are incompatible with high volume manufacturing and the LED industry needs to evolve to projection steppers. The need for projection lithography tools for LED manufacturing is identified in the Solid State Lighting Manufacturing Roadmap Draft, June 2009. The Roadmap states that Projection tools are needed by 2011. This work will modify a stepper, originally designed for semiconductor manufacturing, for use in LED manufacturing. This work addresses improvements to yield, material handling, automation and throughput for LED manufacturing while reducing the capital equipment cost.

  1. Resistance to immunotherapy: clouds in a bright sky.

    Science.gov (United States)

    Milano, Gérard

    2017-10-01

    Two major challenges persist for an optimal management of immunotherapy: i) identifying those patients who will benefit from this type of therapy, and ii) determining the biological, cellular and molecular mechanisms that trigger disease progression while on therapy. There is a consensual view in favor of standardizing practices currently used to measure programmed death ligand 1 (PD-L1) expression that relates to innate resistance. The tumor mutation landscape has been widely explored as a potential predictor of treatment efficacy. In contrast, our knowledge is rather limited as concerns the mechanisms sustaining acquired resistance to checkpoint blockade immunotherapy in patients under treatment. Upregulation of T cell immunoglobulin mucin domain 3 (TIM-3) in CD8+ T-cells has been reported in patients developing acquired resistance to anti-PD-1 treatment. Resistance mechanisms are even more complex for combinatorial strategies linking immunotherapeutic agents and conventional therapies, an area that is expanding rapidly. However, with the arrival of advanced analytical methods such as mass cytometry, there is reason for optimism. These methods can identify cellular mechanisms governing response to therapy and resistance. The clinical use of inhibitors of tumor-microenvironment-modulated pathways, such as those targeting indoleamine 2, 3-dioxygenase (IDO), hold promise for resistance management. Graphical abstract Clouds in a bright sky - Joseph Mallord William Turner.

  2. Bright Soil Near 'McCool': Salty Deja Vu?

    Science.gov (United States)

    2006-01-01

    While driving eastward toward the northwestern flank of 'McCool Hill,' the wheels of NASA's Mars Exploration Rover Spirit churned up the largest amount of bright soil discovered so far in the mission. This image from Spirit's navigation camera, taken on the rover's 787th Martian day, or sol, of exploration (March 21, 2006), shows the strikingly light tone and large extent of the deposit. A few days earlier, Spirit's wheels unearthed a small patch of light-toned material informally named 'Tyrone.' In images from Spirit's panoramic camera, 'Tyrone' strongly resembled both 'Arad' and 'Paso Robles,' two patches of light-toned soils discovered earlier in the mission. Spirit found 'Paso Robles' in 2005 while climbing 'Cumberland Ridge' on the western slope of 'Husband Hill.' In early January 2006, the rover discovered 'Arad' on the basin floor just south of 'Husband Hill.' Spirit's instruments confirmed that those soils had a salty chemistry dominated by iron-bearing sulfates. Spirit's miniature thermal emission spectrometer is analyzing this most recent discovery, and researchers will compare it with those other deposits. These discoveries indicate that light-toned soil deposits might be widely distributed on the flanks and valley floors of the 'Columbia Hills' region in Gusev Crater on Mars. The salts may record the past presence of water, as they are easily mobilized and concentrated in liquid solution.

  3. Half-brightness measurements of candidate radiation sensors

    Science.gov (United States)

    Williams, Stephen Alexander

    Ionizing radiation poses a significant challenge for human and robotic space missions. Practical luminescent sensors will depend heavily upon research investigating the resistance of these materials to ionizing radiation and the ability to anneal or self-heal the damage caused by such radiation. In 1951, Birks and Black experimentally showed that the luminescent efficiency of anthracene bombarded by alpha particles varies with total fluence. From 1990 to the present, we found that the Birks and Black relation describes the reduction in light emission yield for every tested luminescent material except lead phosphate glass due to proton irradiation. These results indicate that radiation produced quenching centers compete with emission for absorbed energy. The purpose of this thesis is to present new results from related luminescent materials by exposing them to a 1-3 MeV proton beam. Particular emphasis will be placed on recent measurements made with bright luminescent materials, such as zinc sulfide doped with manganese (ZnS:Mn), europium tetrakis dibenzoylmethide triethylammonium (EuD4TEA), an magnesium tetrakis dibenzoylmethide triethylammonium (MgD4TEA). This research can be used to help determine if luminescent materials can be used as a real-time sensor to detect ionizing radiation.

  4. Photometry of some more neglected bright cataclysmic variables and candidates

    Science.gov (United States)

    Bruch, Albert

    2018-01-01

    As part of an effort to better characterize bright cataclysmic variables (CVs) and related systems which have received little attention in the past light curves of four systems (V504 Cen, KT Eri, Ret 1 and CTCV 2056-3014) are analyzed. For some of these stars no time resolved photometry has been published previously. While flickering is observed in all systems except Ret 1, it is particularly strong in V504 Cen and CTCV 2056-3014. In the latter star, a previously observed 15.4 m period, leading to its tentative classification as an intermediate polar, is probably spurious. Variations on time scales of hundredths of days observed in the pre-outburst light curve of the classical nova KT Eri continue after the outburst but appear not to be strictly periodic. Furthermore, the long term post-outburst light curve exhibits modulations with quasi-periods of quite different length. Thus, these variations cannot be due to aspect related variations in a system with a giant component similar to some recurrent novae. Instead, the system possibly exhibits variations with a period of 0.1952 d which may be orbital. However, any such conclusion still requires confirmation. The absence of flickering in Ret 1 indicates that the system probably does not contain an accretion disk. Instead, the observation of slow variations supports a previous suspicion of low amplitude variability with a period >12 h.

  5. Graphical Methods for Quantifying Macromolecules through Bright Field Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hang; DeFilippis, Rosa Anna; Tlsty, Thea D.; Parvin, Bahram

    2008-08-14

    Bright ?eld imaging of biological samples stained with antibodies and/or special stains provides a rapid protocol for visualizing various macromolecules. However, this method of sample staining and imaging is rarely employed for direct quantitative analysis due to variations in sample fixations, ambiguities introduced by color composition, and the limited dynamic range of imaging instruments. We demonstrate that, through the decomposition of color signals, staining can be scored on a cell-by-cell basis. We have applied our method to Flbroblasts grown from histologically normal breast tissue biopsies obtained from two distinct populations. Initially, nuclear regions are segmented through conversion of color images into gray scale, and detection of dark elliptic features. Subsequently, the strength of staining is quanti?ed by a color decomposition model that is optimized by a graph cut algorithm. In rare cases where nuclear signal is significantly altered as a result of samplepreparation, nuclear segmentation can be validated and corrected. Finally, segmented stained patterns are associated with each nuclear region following region-based tessellation. Compared to classical non-negative matrix factorization, proposed method (i) improves color decomposition, (ii) has a better noise immunity, (iii) is more invariant to initial conditions, and (iv) has a superior computing performance

  6. Temporal intensity interferometry: photon bunching in three bright stars

    Science.gov (United States)

    Guerin, W.; Dussaux, A.; Fouché, M.; Labeyrie, G.; Rivet, J.-P.; Vernet, D.; Vakili, F.; Kaiser, R.

    2017-12-01

    We report the first intensity correlation measured with starlight since the historical experiments of Hanbury Brown and Twiss. The photon bunching g(2)(τ, r = 0), obtained in the photon-counting regime, was measured for three bright stars: α Boo, α CMi and β Gem. The light was collected at the focal plane of a 1-m optical telescope, transported by a multi-mode optical fibre, split into two avalanche photodiodes and correlated digitally in real time. For total exposure times of a few hours, we obtained contrast values around 2 × 10-3, in agreement with the expectation for chaotic sources, given the optical and electronic bandwidths of our set-up. Comparing our results with the measurement of Hanbury Brown et al. for α CMi, we argue for the timely opportunity to extend our experiments to measuring the spatial correlation function over existing and/or foreseen arrays of optical telescopes diluted over several kilometres. This would enable microarcsec long-baseline interferometry in the optical, especially in the visible wavelengths, with a limiting magnitude of 10.

  7. The new world atlas of artificial night sky brightness

    Science.gov (United States)

    Falchi, Fabio; Cinzano, Pierantonio; Duriscoe, Dan; Kyba, Christopher C. M.; Elvidge, Christopher D.; Baugh, Kimberly; Portnov, Boris A.; Rybnikova, Nataliya A.; Furgoni, Riccardo

    2016-01-01

    Artificial lights raise night sky luminance, creating the most visible effect of light pollution—artificial skyglow. Despite the increasing interest among scientists in fields such as ecology, astronomy, health care, and land-use planning, light pollution lacks a current quantification of its magnitude on a global scale. To overcome this, we present the world atlas of artificial sky luminance, computed with our light pollution propagation software using new high-resolution satellite data and new precision sky brightness measurements. This atlas shows that more than 80% of the world and more than 99% of the U.S. and European populations live under light-polluted skies. The Milky Way is hidden from more than one-third of humanity, including 60% of Europeans and nearly 80% of North Americans. Moreover, 23% of the world’s land surfaces between 75°N and 60°S, 88% of Europe, and almost half of the United States experience light-polluted nights. PMID:27386582

  8. Tolerance of brightness and contrast adjustments on chronic apical abscess and apical granuloma interpretation

    Science.gov (United States)

    Purnamasari, L.; Iskandar, H. H. B.; Makes, B. N.

    2017-08-01

    In digitized radiography techniques, adjusting the image enhancement can improve the subjective image quality by optimizing the brightness and contrast for diagnostic needs. To determine the value range of image enhancement (brightness and contrast) on chronic apical abscess and apical granuloma interpretation. 30 periapical radiographs that diagnosed chronic apical abscess and 30 that diagnosed apical granuloma were adjusted by changing brightness and contrast values. The value range of brightness and contrast adjustment that can be tolerated in radiographic interpretations of chronic apical abscess and apical granuloma spans from -10 to +10. Brightness and contrast adjustments on digital radiographs do not affect the radiographic interpretation of chronic apical abscess and apical granuloma if conducted within the value range.

  9. Long-term Spectroscopic and Photometric Monitoring of Bright Interacting Algol-type Binary Stars

    Science.gov (United States)

    Reed, Phillip A.

    2018-01-01

    Binary stars have long been used as natural laboratories for studying such fundamental stellar properties as mass. Interacting binaries allow us to examine more complicated aspects such as mass flow between stars, accretion processes, magnetic fields, and stellar mergers. Algol-type interacting binary stars -- consisting of a cool giant or sub-giant donating mass to a much hotter, less evolved, and more massive main-sequence companion -- undergo steady mass transfer and have been used to measure mass transfer rates and to test stellar evolution theories. The method of back-projection Doppler tomography has also been applied to interacting Algols and has produced indirect velocity-space images of the accretion structures (gas streams, accretion disks, etc.) derived from spectroscopic observations of hydrogen and helium emission lines. The accretion structures in several Algol systems have actually been observed to change between disk-like states and stream-like states on timescales as short as several orbital cycles (Richards et al., 2014). Presented here are the first results from a project aimed at studying bright interacting Algol systems with simultaneous mid-resolution (11,000project is to determine the periodicity of changes between stream-like and disk-like states over different temperature regimes, to identify the various accretion phenomena, and to extract their physical properties.

  10. VizieR Online Data Catalog: Optically Bright extragalactic Radio Sources II (Petrov, 2013)

    Science.gov (United States)

    Petrov, L.

    2014-06-01

    The first VLBI (Very Long Baseline Interferometry) observing campaign in 2007 resulted in the detection of 398 targets with the European VLBI Network (EVN; Bourda et al., 2010, cat. J/A+A/520/A113). During the second observing campaign, a subset of 105 sources detected in the previous campaign was observed (Bourda et al., 2011, cat. J/A+A/526/A102). Their positions were derived by Petrov (2011, cat. J/AJ/142/105) and formed the OBRS-1 (Optically Bright extragalactic Radio Sources) catalog. The remaining sources were observed in the third campaign, called OBRS-2. During the OBRS-2 campaign, there were three observing sessions with 10 VLBA (Very Long Baseline Array) stations and 5-6 EVN stations from this list: EFLSBERG, MEDICINA, ONSALA60, YEBES40M, DSS63, HARTRAO, and NOTO. Observations were made on 2010 Mar 23 (session ID gc034a), on 2011 Nov 8 (gc034bcd), and on 2011 Mar 15 (gc034ef). The OBRS-2 catalog presents precise positions of the 295 extragalactic radio sources as well as median correlated flux densities at 8.4 and 2.2GHz at baseline lengths shorter than 900km and at baseline lengths longer than 5000km. (1 data file).

  11. Identification and quantification of metallo-chlorophyll complexes in bright green table olives by high-performance liquid chromatrography-mass spectrometry quadrupole/time-of-flight.

    Science.gov (United States)

    Aparicio-Ruiz, Ramón; Riedl, Ken M; Schwartz, Steven J

    2011-10-26

    Five different samples of table olives, two regular Spanish table olives and three "bright green table olives", have been analyzed by HPLC-MS/MS to determine their pigment profile. Typical pigment profiles of almost all table olives show primarily chlorophyll derivatives lacking metals (e.g., pheophytin a/b and 15(2)-Me-phytol-chlorin e(6)). Bright green table olives have a unique profile including metallo-chlorophyll complexes (Cu-15(2)-Me-phytol-chlorin e(6) with 26-48% and Cu-pheophytin a with 3-18%) as their major pigments. New tentative structures have been identified by MS such as 15(2)-Me-phytol-rhodin g(7), 15(2)-Me-phytol-chlorin e(6), 15(2)-Me-phytol-isochlorin e(4), Cu-15(2)-Me-phytol-rhodin g(7), Cu-15(2)-Me-phytol-chlorin e(6), and Cu-15(2)-Me-phytol-isochlorin e(4), and new MS/MS fragmentation patterns are reported for Cu-15(2)-Me-phytol-rhodin g(7), Cu-15(2)-Me-phytol-chlorin e(6), Cu-pheophytin b, Cu-pheophytin a, Cu-pyropheophytin b, and Cu-pyropheophytin a. The presence of metallo-chlorophyll derivatives is responsible for the intense color of bright green table olives, but these metallo-chlorophyll complexes may be regarded as a "green staining" defect that is unacceptable to consumers.

  12. Generative Mechanisms of Romanian Derivational Morphology

    Directory of Open Access Journals (Sweden)

    Mircea Petic

    2011-10-01

    Full Text Available The article studies the problem of a Romanian morphologic derivative generator development. The starting point is a lexicon that provides storage of derivatives in a lexicon, which contains not only the graphical representation of derivatives but also their constituent morphemes. This allows studying and formulating rules that would generate derivatives taking into account certain restrictions. The article deals with different cases of derivation, such as: semi-analyzable derivation, regular derivation, the projection process of the derivation with prefixation on the following suffixation, and derivatives with prefixes im-/in.

  13. octene derivatives

    Indian Academy of Sciences (India)

    Ultrasonication; trimethylsilyloxy-derivatives; bicyclo[2.2.2]octene; Diels–Alder reaction; crystal structure; C–H. . . O and π...π interactions. 1. ... of silyl- derivatives were studied.8 The structural studies indicated a self-assembly ..... Technology (DST), New Delhi, India for the financial assistance. References. 1. Zhao F, Zhang ...

  14. Financial Derivatives

    DEFF Research Database (Denmark)

    Wigan, Duncan

    2013-01-01

    Contemporary derivatives mark the development of capital and constitute a novel form of ownership. By reconfiguring the temporal, spatial and legal character of ownership derivatives present a substantive challenge to the tax collecting state. While fiscal systems are nationally bounded and inheren...

  15. Portable, Battery-Operated, Low-Cost, Bright Field and Fluorescence Microscope

    Science.gov (United States)

    Miller, Andrew R.; Davis, Gregory L.; Oden, Z. Maria; Razavi, Mohamad Reza; Fateh, Abolfazl; Ghazanfari, Morteza; Abdolrahimi, Farid; Poorazar, Shahin; Sakhaie, Fatemeh; Olsen, Randall J.; Bahrmand, Ahmad Reza; Pierce, Mark C.; Graviss, Edward A.; Richards-Kortum, Rebecca

    2010-01-01

    This study describes the design and evaluation of a portable bright-field and fluorescence microscope that can be manufactured for $240 USD. The microscope uses a battery-operated LED-based flashlight as the light source and achieves a resolution of 0.8 µm at 1000× magnification in fluorescence mode. We tested the diagnostic capability of this new instrument to identify infections caused by the human pathogen, Mycobacterium tuberculosis. Sixty-four direct, decontaminated, and serially diluted smears were prepared from sputa obtained from 19 patients suspected to have M. tuberculosis infection. Slides were stained with auramine orange and evaluated as being positive or negative for M. tuberculosis with both the new portable fluorescence microscope and a laboratory grade fluorescence microscope. Concordant results were obtained in 98.4% of cases. This highly portable, low cost, fluorescence microscope may be a useful diagnostic tool to expand the availability of M. tuberculosis testing at the point-of-care in low resource settings. PMID:20694194

  16. Portable, battery-operated, low-cost, bright field and fluorescence microscope.

    Science.gov (United States)

    Miller, Andrew R; Davis, Gregory L; Oden, Z Maria; Razavi, Mohamad Reza; Fateh, Abolfazl; Ghazanfari, Morteza; Abdolrahimi, Farid; Poorazar, Shahin; Sakhaie, Fatemeh; Olsen, Randall J; Bahrmand, Ahmad Reza; Pierce, Mark C; Graviss, Edward A; Richards-Kortum, Rebecca

    2010-08-04

    This study describes the design and evaluation of a portable bright-field and fluorescence microscope that can be manufactured for $240 USD. The microscope uses a battery-operated LED-based flashlight as the light source and achieves a resolution of 0.8 microm at 1000x magnification in fluorescence mode. We tested the diagnostic capability of this new instrument to identify infections caused by the human pathogen, Mycobacterium tuberculosis. Sixty-four direct, decontaminated, and serially diluted smears were prepared from sputa obtained from 19 patients suspected to have M. tuberculosis infection. Slides were stained with auramine orange and evaluated as being positive or negative for M. tuberculosis with both the new portable fluorescence microscope and a laboratory grade fluorescence microscope. Concordant results were obtained in 98.4% of cases. This highly portable, low cost, fluorescence microscope may be a useful diagnostic tool to expand the availability of M. tuberculosis testing at the point-of-care in low resource settings.

  17. Towards Bright and Fast Lu3Al5O12:Ce,Mg Optical Ceramics Scintillators

    CERN Document Server

    Liu, Shuping; Feng, Xiqi; Vedda, Anna; Fasoli, Mauro; Shi, Yun; Kou, Huamin; Beitlerova, Alena; Wu, Lexiang; D'Ambrosio, Carmelo; Pan, Yubai; Nikl, Martin

    2016-01-01

    The recent advent of Lu 3 Al 5 O 12 :Ce optical ceramics marks a turning point in scintillator material technology. Because of their lower preparation tem-perature, brightness, and robustness such materials can now compete with single crystals. Their further scintillation effi ciency optimization includes the thorough control of the defects responsible for optical and scintillation losses. The choice of sintering agent appears critical to achieve both high optical transparency and scintillation performance. In this work, the optical investi-gations coupled with X-ray absorption near-edge spectroscopy evidence the benefi cial role of MgO sintering agent. Mg 2+ co-dopants in ceramics drive the partial conversion of Ce 3+ to Ce 4+ . The Ce 4+ center, however, does not impair the scintillation performance due to its capability to positively infl uence the scintillation process. The importance of simultaneous application of such co-doping and annealing treatment is also demonstrated. With 0.3 at% Mg, our cer...

  18. Highly bright X-ray generator using heat of fusion with a specially designed rotating anticathode

    Energy Technology Data Exchange (ETDEWEB)

    Sakabe, N., E-mail: nsakabe@sbsp.jp [PF, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Foundation for Advancement of International Science, 586-9 Akatsuka, Tsukuba, Ibaraki 305-0062 (Japan); Ohsawa, S.; Sugimura, T.; Ikeda, M.; Tawada, M. [Accelerator Laboratory, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Watanabe, N. [Synchrotron Radiation Research Center, Nagoya University, Chikusa, Nagoya, Aichi 464-8603 (Japan); Sasaki, K. [Nagoya University, Chikusa, Nagoya, Aichi 464-8601 (Japan); Ohshima, K. [Institute of Materials Science, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8573 (Japan); Wakatsuki, M. [AIST, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Sakabe, K. [Foundation for Advancement of International Science, 586-9 Akatsuka, Tsukuba, Ibaraki 305-0062 (Japan)

    2008-05-01

    A very compact X-ray generator, 4.3 times more brilliant than can be attained by a conventional rotating-anticathode X-ray generator, has been developed using a U-shaped rotating anticathode and a high-flux electron gun with focusing bending magnet. A new type of rotating anticathode X-ray generator has been developed, in which the electron beam irradiates the inner surface of a U-shaped anticathode (Cu). A high-flux electron beam is focused on the inner surface by optimizing the shape of the bending magnet. The power of the electron beam can be increased to the point at which the irradiated part of the inner surface is melted, because a strong centrifugal force fixes the melted part on the inner surface. When the irradiated part is melted, a large amount of energy is stored as the heat of fusion, resulting in emission of X-rays 4.3 times more brilliant than can be attained by a conventional rotating anticathode. Oscillating translation of the irradiated position on the inner surface during use is expected to be very advantageous for extending the target life. A carbon film coating on the inner surface is considered to suppress evaporation of the target metal and will be an important technique in further realization of highly bright X-ray generation.

  19. Preparation of brightness stabilization agent for lignin containing pulp from biomass pyrolysis oils

    Science.gov (United States)

    Agblevor, Foster A.; Besler-Guran, Serpil

    2001-01-01

    A process for producing a brightness stabilization mixture of water-soluble organic compounds from biomass pyrolysis oils comprising: a) size-reducing biomass material and pyrolyzing the size-reduced biomass material in a fluidized bed reactor; b) separating a char/ash component while maintaining char-pot temperatures to avoid condensation of pyrolysis vapors; c) condensing pyrolysis gases and vapors, and recovering pyrolysis oils by mixing the oils with acetone to obtain an oil-acetone mixture; d) evaporating acetone and recovering pyrolysis oils; e) extracting the pyrolysis oils with water to obtain a water extract; f) slurrying the water extract with carbon while stirring, and filtering the slurry to obtain a colorless filtrate; g) cooling the solution and stabilizing the solution against thermally-induced gelling and solidification by extraction with ethyl acetate to form an aqueous phase lower layer and an organic phase upper layer; h) discarding the upper organic layer and extracting the aqueous layer with ethyl acetate, and discarding the ethyl acetate fraction to obtain a brown-colored solution not susceptible to gelling or solidification upon heating; i) heating the solution to distill off water and other light components and concentrating a bottoms fraction comprising hydroxyacetaldehyde and other non-volatile components having high boiling points; and j) decolorizing the stabilized brown solution with activated carbon to obtain a colorless solution.

  20. DETECTION OF AN ULTRA-BRIGHT SUBMILLIMETER GALAXY BEHIND THE SMALL MAGELLANIC CLOUD

    Energy Technology Data Exchange (ETDEWEB)

    Takekoshi, Tatsuya; Minamidani, Tetsuhiro; Sorai, Kazuo; Habe, Asao [Department of Cosmosciences, Graduate School of Science, Hokkaido University, Sapporo 060-0810 (Japan); Tamura, Yoichi; Kohno, Kotaro [Institute of Astronomy, University of Tokyo, Osawa, Mitaka, Tokyo 181-0015 (Japan); Oogi, Taira [Department of Physics, Faculty of Science, Hokkaido University, Sapporo 060-0810 (Japan); Ezawa, Hajime; Komugi, Shinya; Mizuno, Norikazu; Muller, Erik; Kawamura, Akiko [Chile Observatory, National Astronomical Observatory, Mitaka, Tokyo 181-8588 (Japan); Oshima, Tai [Nobeyama Radio Observatory, National Astronomical Observatory of Japan, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Scott, Kimberly S. [North American ALMA Science Center, National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Austermann, Jason E. [Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309 (United States); Tosaki, Tomoka [Joetsu University of Education, Joetsu, Niigata 943-8512 (Japan); Onishi, Toshikazu [Department of Physical Science, Osaka Prefecture University, Gakuen 1-1, Sakai, 599-8531 Osaka (Japan); Fukui, Yasuo [Department of Astrophysics, Nagoya University, Chikusa-ku, Nagoya 464-8602 (Japan); Matsuo, Hiroshi [Advanced Technology Center, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Aretxaga, Itziar [Instituto Nacional de Astrofisica, Optica y Electronica (INAOE), 72000 Puebla (Mexico); and others

    2013-09-10

    We report the discovery of a new ultra-bright submillimeter galaxy (SMG) behind the Small Magellanic Cloud (SMC). This SMG is detected as a 43.3 {+-} 8.4 mJy point source (MM J01071-7302, hereafter MMJ0107) in the 1.1 mm continuum survey of the SMC by AzTEC on the ASTE telescope. MMJ0107 is also detected in the radio (843 MHz), Herschel/SPIRE, Spitzer MIPS 24 {mu}m, all IRAC bands, Wide-field Infrared Survey Explorer, and near-infrared (J, H, K{sub S} ). We find an optical (U, B, V) source, which might be the lensing object, at a distance of 1.''4 from near-infrared and IRAC sources. Photometric redshift estimates for the SMG using representative spectral energy distribution templates show the redshifts of 1.4-3.9. We estimate total far-infrared luminosity of (0.3-2.2) Multiplication-Sign 10{sup 14} {mu}{sup -1} L{sub Sun} and a star formation rate of 5600-39, 000 {mu}{sup -1} M{sub Sun} yr{sup -1}, where {mu} is the gravitational magnification factor. This apparent extreme star formation activity is likely explained by a highly magnified gravitational lens system.

  1. Detecting the brightness temperature from Landsat-8 thermal infra red scanner preceding the Rinjani strombolian eruption 2015

    Science.gov (United States)

    Suwarsono, Hidayat, Suprapto, Totok; Prasasti, Indah; Parwati, Rokhis Khomarudin, M.

    2017-07-01

    At the end of October to early November 2015, Rinjani Volcano that is located in Lombok Island was erupted and has catapulted the ash, pyroclastic and lava flow. The dispersion of this volcanic ash in the atmosphere has been disrupting flights and the three closest airports to be closed for a while. The existence of Rinjani Volcano geographically plays an important role in the survival of life on the island of Lombok, because large areas of land on the island are a part of the Rinjani Volcano landscape. Based on the experience of violent eruptions that have occurred in the 13th century ago, the monitoring of the volcanism activity of this volcano needs to be done intensively and continuously. This is something important to do an early detection efforts of the volcanic eruption. These efforts need to be done as a preparedness effort in order to minimize adverse impacts that may occur as a result of this eruption. This research tries to detect the volcanic eruption precursor based on changes in temperature conditions of the crater and the surrounding area. We use the medium resolution satellite data, Thermal Infra Red Scanner (TIRS), on board Landsat-8, to monitor the brightness temperature as a representative of surface temperature of the volcanic region. The results showed that the brightness temperature derived from Landsat-8 TIRS is very usefull to predict the strombolian eruption which will occur in the near future. The use of multitemporal image data is important to understand the dynamics of volcanism activity over time.

  2. Modelling of the L-band brightness temperatures measured with ELBARA III radiometer on Bubnow wetland

    Science.gov (United States)

    Gluba, Lukasz; Sagan, Joanna; Lukowski, Mateusz; Szlazak, Radoslaw; Usowicz, Boguslaw

    2017-04-01

    Microwave radiometry has become the main tool for investigating soil moisture (SM) with remote sensing methods. ESA - SMOS (Soil Moisture and Ocean Salinity) satellite operating at L-band provides global distribution of soil moisture. An integral part of SMOS mission are calibration and validation activities involving measurements with ELBARA III which is an L-band microwave passive radiometer. It is done in order to improve soil moisture retrievals - make them more time-effective and accurate. The instrument is located at Bubnow test-site, on the border of cultivated field, fallow, meadow and natural wetland being a part of Polesie National Park (Poland). We obtain both temporal and spatial dependences of brightness temperatures for varied types of land covers with the ELBARA III directed at different azimuths. Soil moisture is retrieved from brightness temperature using L-band Microwave Emission of the Biosphere (L-MEB) model, the same as currently used radiative transfer model for SMOS. Parametrization of L-MEB, as well as input values are still under debate. We discuss the results of SM retrievals basing on data obtained during first year of the radiometer's operation. We analyze temporal dependences of retrieved SM for one-parameter (SM), two-parameter (SM, τ - optical depth) and three-parameter (SM, τ, Hr - roughness parameter) retrievals, as well as spatial dependences for specific dates. Special case of Simplified Roughness Parametrization, combining the roughness parameter and optical depth, is considered. L-MEB processing is supported by the continuous measurements of soil moisture and temperature obtained from nearby agrometeorological station, as well as studies on the soil granulometric composition of the Bubnow test-site area. Furthermore, for better estimation of optical depth, the satellite-derived Normalized Difference Vegetation Index (NDVI) was employed, supported by measured in situ vegetation parameters (such as Leaf Area Index and Vegetation

  3. Analysis of Mass Profiles and Cooling Flows of Bright, Early-Type Galaxies AO2, AO3 and Surface Brightness Profiles and Energetics of Intracluster Gas in Cool Galaxy Clusters AO3

    Science.gov (United States)

    White, Raymond E., III

    1998-01-01

    This final report uses ROSAT observations to analyze two different studies. These studies are: Analysis of Mass Profiles and Cooling Flows of Bright, Early-Type Galaxies; and Surface Brightness Profiles and Energetics of Intracluster Gas in Cool Galaxy Clusters.

  4. Where to Find Young Bright Stars in Geosciences: GGD, NSU

    Science.gov (United States)

    Rakhmenkoulova, I. F.; Sharapov, V. N.

    2004-12-01

    Geology and Geophysics Department (GGD) of Novosibirsk State University (NSU) can be regarded as infant, because it was founded in 1962. On the other hand, if to judge by what have been done - it is not only full-fledged, but well-known department. The unique location and specific educational and scientific traditions make GGD a famous school not only in Siberia, but in Russia, and all over the world. What are the tips to prepare bright stars in geosciences? 1.NSU is located in Academgorodok (Novosibirsk scientific center), unique place in Siberia, where more than 20 scientific institutions are located. This makes the University different from other schools in Russia. Famous Russian scientists, including members of RAS, together with foreign professors give lectures and seminars for NSU students. 2.The bright star hunting starts far below the NSU level. Each year in April there is a special event in Academgorodok -`Geologic Olympiad', where children of all Russian regions, as well as ex-Soviet republics are gathered together to submit their papers, to discuss most interesting geoscience problems and to win prizes for their knowledge. The youngest stars happen to be only 6-7 years old. The event is sponsored by NSU, UIGGM, and the Ministry of Natural Resources. The brightest geostars are grown from `Geologic Olympiad' participants. 3.There is special physics-mathematical high school in Academgorodok. Each summer this school gathers young stars from farthest Siberian and Far East regions and gives classes and seminars in mathematics, physics, chemistry and geology. As the result the most talented children become the students of this school (for two years). The school in turn supplies GGD with the students. 4.NSU has the study curriculum different from other universities in Russia. That is why the entrance examinations are much more difficult as compared to other schools and are taken in July (a month earlier then at other universities). However the entrance

  5. Creation, Transport and Measurement of Bright Relativistic Electron Beams.

    Science.gov (United States)

    McKee, Chad Bennett

    This thesis deals with three topics relevant to linac-driven free electron lasers: the creation, transport and measurement of bright relativistic electron beams. Thermionic microwave electron guns produce bright electron beams that are well suited to drive free electron lasers, FELs. The rf fields in the gun cause some of the emitted electrons to reverse direction and strike the cathode. These back-bombarding electrons heat the cathode limiting both the pulse length and time averaged current. The cathode heating is reduced if a transverse magnetic field is applied across the gun cavity to deflect back-bombarding electrons. We improve the thermionic microwave electron gun by redesigning the deflection magnet to minimize the back-heating power. Computer simulations show that transverse magnetic fields with rapid axial falloffs reduce the back-heating power more than fields that are axially constant. Experiments verify these simulations. The deflection magnet presently installed on the Mark III gun has a slow axial falloff and reduces the back-heating power by 31%. Using the simulation results we design a new deflection magnet having a rapid axial falloff. This magnet has been installed on the NCCU gun and reduces the back-heating power by 63%. Improper transport of the electron beam through the beam line degrades the quality of the electron beam and lowers the performance of the FEL. We propose to improve the beam line commissioning and control procedures on linac -driven FELs by experimentally measuring the transfer matrix of each beam line section. The transfer matrix of a given section is measured by dithering the electron beam, measuring the beam vector before and after the section and inverting the subsequent data matrix. We minimize the beam line errors by minimizing the deviation between the experimentally measured transfer matrix and the design transfer matrix of each beam line section. While not experimentally verified, computer simulations show that this

  6. Microwave brightness temperature and thermal inertia - towards synergistic method of high-resolution soil moisture retrieval

    Science.gov (United States)

    Lukowski, Mateusz; Usowicz, Boguslaw; Sagan, Joanna; Szlazak, Radoslaw; Gluba, Lukasz; Rojek, Edyta

    2017-04-01

    Soil moisture is an important parameter in many environmental studies, as it influences the exchange of water and energy at the interface between the land surface and the atmosphere. Accurate assessment of the soil moisture spatial and temporal variations is crucial for numerous studies; starting from a small scale of single field, then catchment, mesoscale basin, ocean conglomeration, finally ending at the global water cycle. Despite numerous advantages, such as fine accuracy (undisturbed by clouds or daytime conditions) and good temporal resolution, passive microwave remote sensing of soil moisture, e.g. SMOS and SMAP, are not applicable to a small scale - simply because of too coarse spatial resolution. On the contrary, thermal infrared-based methods of soil moisture retrieval have a good spatial resolution, but are often disturbed by clouds and vegetation interferences or night effects. The methods that base on point measurements, collected in situ by monitoring stations or during field campaigns, are sometimes called "ground truth" and may serve as a reference for remote sensing, of course after some up-scaling and approximation procedures that are, unfortunately, potential source of error. Presented research concern attempt to synergistic approach that join two remote sensing methods: passive microwave and thermal infrared, supported by in situ measurements. Microwave brightness temperature of soil was measured by ELBARA, the radiometer at 1.4 GHz frequency, installed at 6 meters high tower at Bubnow test site in Poland. Thermal inertia around the tower was modelled using the statistical-physical model whose inputs were: soil physical properties, its water content, albedo and surface temperatures measured by an infrared pyrometer, directed at the same footprint as ELBARA. The results coming from this method were compared to in situ data obtained during several field campaigns and by the stationary agrometeorological stations. The approach seems to be

  7. TRIGGERED STAR FORMATION IN A BRIGHT-RIMMED CLOUD (BRC 5) OF IC 1805

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Naoya [Faculty of Biosphere-Geosphere Science, Okayama University of Science, 1-1 Ridai-chou, Okayama 700-0005 (Japan); Miao, Jingqi [Centre for Astrophysics and Planetary Science, School of Physical Sciences, University of Kent, Canterbury, Kent CT2 7NR (United Kingdom); Sugitani, Koji [Graduate School of Natural Sciences, Nagoya City University, Mizuho-ku, Nagoya 467-8501 (Japan); Kawahara, Kentaro [Faculty of Informatics, Okayama University of Science, 1-1 Ridai-chou, Okayama 700-0005 (Japan); Watanabe, Makoto [Department of Cosmosciences, Hokkaido University, Kita 10, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810 (Japan); Nakano, Makoto [Faculty of Education and Welfare Science, Oita University, Oita 870-1192 (Japan); Pickles, Andrew J., E-mail: fukudany@big.ous.ac.jp [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Goleta, CA 93117 (United States)

    2013-08-20

    We report recent optical, near-infrared (NIR), and millimeter observations which have revealed some new features of the bright-rimmed cloud BRC 5 associated with W4. With slitless spectroscopy, we detected 17 H{alpha} emission stars around the cloud; 4 are near the surface of the cloud, and 1 is toward IRAS 02252+6120. NIR photometry shows that the central H{alpha} emission star, together with one bright infrared source, has large NIR excesses and Class I spectral energy distributions. These two Class I objects are associated with the 2.9 mm continuum peaks and with a bipolar outflow, and are in between two separate, elongated C{sup 18}O(J = 1-0) cores. The C{sup 18}O cores and the two Class I sources are aligned along a line at position angle {approx}240 Degree-Sign , somewhat less than perpendicular to the direction of UV radiation from the OB stars. Most of the detected H{alpha} emission stars, all T Tauri candidates, are located within {approx}3' of the cloud on the exciting star side. An estimate of the age of the stars based on a color-magnitude diagram suggests that these T Tauri candidates have ages of {approx}1 Myr or less, but are more evolved objects than the central young stellar objects. This age sequence suggests sequential star formation within the BRC 5 cloud. The {sup 13}CO(J = 1-0) emission shows three elongated structures, which indicates the asymmetric structure toward the UV incident axis. We present our exploratory simulation results by using a smoothed particle hydrodynamic code that suggests that the asymmetrical BRC 5 structure could possibly result from the evolution of a preexisting prolate molecular cloud subject to radiation-driven implosion (RDI). Our best-fit prolate cloud has an initial mass of {approx}400 M{sub Sun }, an axial ratio of {approx}1.7, and a semi-major axis of {approx}1.6 pc, pointing away from the ionization flux by an angle of 15 Degree-Sign . The simulated cloud structure not only closely matches the observed

  8. Prognostic factors for acute encephalopathy with bright tree appearance.

    Science.gov (United States)

    Azuma, Junji; Nabatame, Shin; Nakano, Sayaka; Iwatani, Yoshiko; Kitai, Yukihiro; Tominaga, Koji; Kagitani-Shimono, Kuriko; Okinaga, Takeshi; Yamamoto, Takehisa; Nagai, Toshisaburo; Ozono, Keiichi

    2015-02-01

    To determine the prognostic factors for encephalopathy with bright tree appearance (BTA) in the acute phase through retrospective case evaluation. We recruited 10 children with encephalopathy who presented with BTA and classified them into 2 groups. Six patients with evident regression and severe psychomotor developmental delay after encephalopathy were included in the severe group, while the remaining 4 patients with mild mental retardation were included in the mild group. We retrospectively analyzed their clinical symptoms, laboratory data, and magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) findings. Patients in the severe group developed subsequent complications such as epilepsy and severe motor impairment. Univariate analysis revealed that higher maximum lactate dehydrogenase (LDH) levels (p=0.055) were a weak predictor of poor outcome. Maximum creatinine levels were significantly higher (p<0.05) and minimal platelet counts were significantly lower (p<0.05) in the severe group than in the mild group. Acute renal failure was not observed in any patient throughout the study. MRS of the BTA lesion during the BTA period showed elevated lactate levels in 5 children in the severe group and 1 child in the mild group. MRI performed during the chronic phase revealed severe brain atrophy in all patients in the severe group. Higher creatinine and LDH levels and lower platelet counts in the acute phase correlated with poor prognosis. Increased lactate levels in the BTA lesion during the BTA period on MRS may predict severe physical and mental disability. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  9. A high-brightness thermionic microwave electron gun

    Energy Technology Data Exchange (ETDEWEB)

    Borland, Michael [Stanford Univ., CA (United States)

    1991-02-01

    In a collaborative effort by SSRL, AET Associates, and Varian Associates, a high-brightness microwave electron gun using a thermionic cathode has been designed, built, tested, and installed for use with the SSRL 150 MeV linear accelerator. This thesis discusses the physics behind the design and operation of the gun and associated systems, presenting predictions and experimental tests of the gun`s performance. The microwave gun concept is of increasing interest due to its promise of providing higher-current, lower-emittance electron beams than possible from conventional, DC gun technology. In a DC guns, accelerating gradients are less than 8 MV/m, while those in a microwave gun can exceed 100 MV/m, providing much more rapid initial acceleration, thereby reducing the deleterious effects of space-charge. Microwave guns produce higher momentum beams than DC guns, thus lessening space-charge effects during subsequent beam transport. Typical DC guns produce kinetic energies of 80--400 KeV, compared to 2--3 MeV for the SSRL microwave gun. ``State-of-the-art`` microwave gun designs employ laser-driven photocathodes, providing excellent performance but with greater complexity and monetary costs. A thermionic microwave gun with a magnetic bunching system is comparable in cost and complexity to a conventional system, but provides performance that is orders of magnitude better. Simulations of the SSRL microwave gun predict a normalized RMS emittance at the gun exist of < 10 π • mec • μm for a beam consisting of approximately 50% of the particles emitted from the gun, and having a momentum spread ±10%. These emittances are for up to 5 x 109e- per bunch. Chromatic aberrations in the transport line between the gun and linear accelerator increase this to typically < 30 π • me • μm.

  10. High brightness diode lasers controlled by volume Bragg gratings

    Science.gov (United States)

    Glebov, Leonid

    2017-02-01

    Volume Bragg gratings (VBGs) recorded in photo-thermo-refractive (PTR) glass are holographic optical elements that are effective spectral and angular filters withstanding high power laser radiation. Reflecting VBGs are narrow-band spectral filters while transmitting VBGs are narrow-band angular filters. The use of these optical elements in external resonators of semiconductor lasers enables extremely resonant feedback that provides dramatic spectral and angular narrowing of laser diodes radiation without significant power and efficiency penalty. Spectral narrowing of laser diodes by reflecting VBGs demonstrated in wide spectral region from near UV to 3 μm. Commercially available VBGs have spectral width ranged from few nanometers to few tens of picometers. Efficient spectral locking was demonstrated for edge emitters (single diodes, bars, modules, and stacks), vertical cavity surface emitting lasers (VCSELs), grating coupled surface emitting lasers (GCSELs), and interband cascade lasers (ICLs). The use of multiplexed VBGs provides multiwavelength emission from a single emitter. Spectrally locked semiconductor lasers demonstrated CW power from milliwatts to a kilowatt. Angular narrowing by transmitting VBGs enables single transverse mode emission from wide aperture diode lasers having resonators with great Fresnel numbers. This feature provides close to diffraction limit divergence along a slow axis of wide stripe edge emitters. Radiation exchange between lasers by means of spatially profiled or multiplexed VBGs enables coherent combining of diode lasers. Sequence of VBGs or multiplexed VBGs enable spectral combining of spectrally narrowed diode lasers or laser modules. Thus the use of VBGs for diode lasers beam control provides dramatic increase of brightness.

  11. Voltage-sensitive rhodol with enhanced two-photon brightness.

    Science.gov (United States)

    Kulkarni, Rishikesh U; Kramer, Daniel J; Pourmandi, Narges; Karbasi, Kaveh; Bateup, Helen S; Miller, Evan W

    2017-03-14

    We have designed, synthesized, and applied a rhodol-based chromophore to a molecular wire-based platform for voltage sensing to achieve fast, sensitive, and bright voltage sensing using two-photon (2P) illumination. Rhodol VoltageFluor-5 (RVF5) is a voltage-sensitive dye with improved 2P cross-section for use in thick tissue or brain samples. RVF5 features a dichlororhodol core with pyrrolidyl substitution at the nitrogen center. In mammalian cells under one-photon (1P) illumination, RVF5 demonstrates high voltage sensitivity (28% ΔF/F per 100 mV) and improved photostability relative to first-generation voltage sensors. This photostability enables multisite optical recordings from neurons lacking tuberous sclerosis complex 1, Tsc1, in a mouse model of genetic epilepsy. Using RVF5, we show that Tsc1 KO neurons exhibit increased activity relative to wild-type neurons and additionally show that the proportion of active neurons in the network increases with the loss of Tsc1. The high photostability and voltage sensitivity of RVF5 is recapitulated under 2P illumination. Finally, the ability to chemically tune the 2P absorption profile through the use of rhodol scaffolds affords the unique opportunity to image neuronal voltage changes in acutely prepared mouse brain slices using 2P illumination. Stimulation of the mouse hippocampus evoked spiking activity that was readily discerned with bath-applied RVF5, demonstrating the utility of RVF5 and molecular wire-based voltage sensors with 2P-optimized fluorophores for imaging voltage in intact brain tissue.

  12. Velocity bunching of high-brightness electron beams

    Directory of Open Access Journals (Sweden)

    S. G. Anderson

    2005-01-01

    Full Text Available Velocity bunching has been recently proposed as a tool for compressing electron beam pulses in modern high brightness photoinjector sources. This tool is familiar from earlier schemes implemented for bunching dc electron sources, but presents peculiar challenges when applied to high current, low emittance beams from photoinjectors. The main difficulty foreseen is control of emittance oscillations in the beam in this scheme, which can be naturally considered as an extension of the emittance compensation process at moderate energies. This paper presents two scenarios in which velocity bunching, combined with emittance control, is to play a role in nascent projects. The first is termed ballistic bunching, where the changing of relative particle velocities and positions occur in distinct regions, a short high gradient linac, and a drift length. This scenario is discussed in the context of the proposed ORION photoinjector. Simulations are used to explore the relationship between the degree of bunching, and the emittance compensation process. Experimental measurements performed at the UCLA Neptune Laboratory of the surprisingly robust bunching process, as well as accompanying deleterious transverse effects, are presented. An unanticipated mechanism for emittance growth in bends for highly momentum chirped beam was identified and studied in these experiments. The second scenario may be designated as phase space rotation, and corresponds closely to the recent proposal of Ferrario and Serafini. Its implementation for the compression of the electron beam pulse length in the PLEIADES inverse Compton scattering (ICS experiment at LLNL is discussed. It is shown in simulations that optimum compression may be obtained by manipulation of the phases in low gradient traveling wave accelerator sections. Measurements of the bunching and emittance control achieved in such an implementation at PLEIADES, as well as aspects of the use of velocity-bunched beam directly

  13. VELOCITY BUNCHING OF HIGH-BRIGHTNESS ELECTRON BEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, S G; Musumeci, P; Rosenzweig, J B; Brown, W J; England, R J; Ferrario, M; Jacob, J S; Thompson, M C; Travish, G; Tremaine, A M; Yoder, R

    2004-10-15

    Velocity bunching has been recently proposed as a tool for compressing electron beam pulses in modern high brightness photoinjector sources. This tool is familiar from earlier schemes implemented for bunching dc electron sources, but presents peculiar challenges when applied to high current, low emittance beams from photoinjectors. The main difficulty foreseen is control of emittance oscillations in the beam in this scheme, which can be naturally considered as an extension of the emittance compensation process at moderate energies. This paper presents two scenarios in which velocity bunching, combined with emittance control, is to play a role in nascent projects. The first is termed ballistic bunching, where the changing of relative particle velocities and positions occur in distinct regions, a short high gradient linac, and a drift length. This scenario is discussed in the context of the proposed ORION photoinjector. Simulations are used to explore the relationship between the degree of bunching, and the emittance compensation process. Experimental measurements performed at the UCLA Neptune Laboratory of the surprisingly robust bunching process, as well as accompanying deleterious transverse effects, are presented. An unanticipated mechanism for emittance growth in bends for highly momentum chirped beam was identified and studied in these experiments. The second scenario may be designated as phase space rotation, and corresponds closely to the recent proposal of Ferrario and Serafini. Its implementation for the compression of the electron beam pulse length in the PLEIADES inverse Compton scattering (ICS) experiment at LLNL is discussed. It is shown in simulations that optimum compression may be obtained by manipulation of the phases in low gradient traveling wave accelerator sections. Measurements of the bunching and emittance control achieved in such an implementation at PLEIADES, as well as aspects of the use of velocity-bunched beam directly in ICS experiments

  14. Communicatively Constructing the Bright and Dark Sides of Hope: Family Caregivers’ Experiences during End of Life Cancer Care

    Directory of Open Access Journals (Sweden)

    Jody Koenig Kellas

    2017-05-01

    Full Text Available (1 Background: The communication of hope is complicated, particularly for family caregivers in the context of cancer who struggle to maintain hope for themselves and their loved ones in the face of terminality. In order to understand these complexities, the current study examines the bright and dark sides of how hope is communicated across the cancer journey from the vantage point of bereaved family caregivers; (2 Methods: We analyzed interviews with bereaved family caregivers using qualitative thematic and case oriented strategies to identify patterns in the positive and negative lived experiences when communicating about hope at the end of life; (3 Results: Two overarching patterns of hope emerged. Those who experienced hope as particularized (focused on cure cited communication about false hope, performing (faking it, and avoidance. Those who transitioned from particularized to generalized hope (hope for a good death reported acceptance, the communication of hope as social support, prioritizing family, and balancing hope and honesty; (4 Conclusion: Family caregivers face myriad complexities in managing the bright and dark sides of hope. Interventions should encourage concurrent oncological and palliative care, increased perspective-taking among family members, and encourage the transition from particularized to generalized hope.

  15. Thermoregulatory effect in humans of suppressed endogenous melatonin by pre-sleep bright-light exposure in a cold environment.

    Science.gov (United States)

    Ishibashi, Keita; Arikura, Satoshi; Kozaki, Tomoaki; Higuchi, Shigekazu; Yasukouchi, Akira

    2010-06-01

    This study investigated the physiological function of suppressed melatonin through thermoregulation in a cold environment. Interactions between thermoregulation directly affected by exposure to a cold environment and indirectly affected by endogenous melatonin suppression by bright-light exposure were examined. Ten male subjects were exposed to two different illumination intensities (30 and 5000 lux) for 4.5 h, and two different ambient temperatures (15 and 27 degrees C) for 2 h before sleep under dark and thermoneutral conditions. Salivary melatonin level was suppressed by bright light (p cold ambient temperature (p cold exposure than thermoneutral conditions (cold: -0.54 +/- 0.07 degrees C/h; thermoneutral: -0.16 +/- 0.03 degrees C/h; p cold exposure masked the circadian rhythm with a precipitous decrease in T(re). A significant correlation between the T(re) nadir and melatonin level (r = -0.774, p cold exposure. These results suggest that suppressed endogenous melatonin inhibits the downregulation of the body temperature set-point during sleep.

  16. The Points Of Language

    Science.gov (United States)

    Meier, Richard P.; Lillo-Martin, Diane

    2017-01-01

    Signed languages display a variety of pointing signs that serve the functions of deictic and anaphoric pronouns, possessive and reflexive pronouns, demonstratives, locatives, determiners, body part labels, and verb agreement. We consider criteria for determining the linguistic status of pointing signs. Among those criteria are conventionality, indexicality, phonological compositionality, being subject to grammatical constraints, and marking the kinds of grammatical distinctions expected of pronouns. We conclude that first-person points meet all these proposed criteria, but that nonfirst person points are in part gestural. Lastly, we review evidence for the grammaticization over time of systems of pointing signs within signed languages. PMID:28603596

  17. Music for a Brighter World: Brightness Judgment Bias by Musical Emotion.

    Directory of Open Access Journals (Sweden)

    Joydeep Bhattacharya

    Full Text Available A prevalent conceptual metaphor is the association of the concepts of good and evil with brightness and darkness, respectively. Music cognition, like metaphor, is possibly embodied, yet no study has addressed the question whether musical emotion can modulate brightness judgment in a metaphor consistent fashion. In three separate experiments, participants judged the brightness of a grey square that was presented after a short excerpt of emotional music. The results of Experiment 1 showed that short musical excerpts are effective emotional primes that cross-modally influence brightness judgment of visual stimuli. Grey squares were consistently judged as brighter after listening to music with a positive valence, as compared to music with a negative valence. The results of Experiment 2 revealed that the bias in brightness judgment does not require an active evaluation of the emotional content of the music. By applying a different experimental procedure in Experiment 3, we showed that this brightness judgment bias is indeed a robust effect. Altogether, our findings demonstrate a powerful role of musical emotion in biasing brightness judgment and that this bias is aligned with the metaphor viewpoint.

  18. Music for a Brighter World: Brightness Judgment Bias by Musical Emotion.

    Science.gov (United States)

    Bhattacharya, Joydeep; Lindsen, Job P

    2016-01-01

    A prevalent conceptual metaphor is the association of the concepts of good and evil with brightness and darkness, respectively. Music cognition, like metaphor, is possibly embodied, yet no study has addressed the question whether musical emotion can modulate brightness judgment in a metaphor consistent fashion. In three separate experiments, participants judged the brightness of a grey square that was presented after a short excerpt of emotional music. The results of Experiment 1 showed that short musical excerpts are effective emotional primes that cross-modally influence brightness judgment of visual stimuli. Grey squares were consistently judged as brighter after listening to music with a positive valence, as compared to music with a negative valence. The results of Experiment 2 revealed that the bias in brightness judgment does not require an active evaluation of the emotional content of the music. By applying a different experimental procedure in Experiment 3, we showed that this brightness judgment bias is indeed a robust effect. Altogether, our findings demonstrate a powerful role of musical emotion in biasing brightness judgment and that this bias is aligned with the metaphor viewpoint.

  19. T1 bright appendix sign to exclude acute appendicitis in pregnant women

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ilah; An, Chansik; Lim, Joon Seok; Kim, Myeong-Jin; Chung, Yong Eun [Yonsei University College of Medicine, Department of Radiology, Research Institute of Radiological Science, Severance Hospital, 50-1 Yonsei-ro, Seodaemun-gu, Seoul (Korea, Republic of)

    2017-08-15

    To evaluate the diagnostic value of the T1 bright appendix sign for the diagnosis of acute appendicitis in pregnant women. This retrospective study included 125 pregnant women with suspected appendicitis who underwent magnetic resonance (MR) imaging. The T1 bright appendix sign was defined as a high intensity signal filling more than half length of the appendix on T1-weighted imaging. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the T1 bright appendix sign for normal appendix identification were calculated in all patients and in those with borderline-sized appendices (6-7 mm). The T1 bright appendix sign was seen in 51% of patients with normal appendices, but only in 4.5% of patients with acute appendicitis. The overall sensitivity, specificity, PPV, and NPV of the T1 bright appendix sign for normal appendix diagnosis were 44.9%, 95.5%, 97.6%, and 30.0%, respectively. All four patients with borderline sized appendix with appendicitis showed negative T1 bright appendix sign. The T1 bright appendix sign is a specific finding for the diagnosis of a normal appendix in pregnant women with suspected acute appendicitis. (orig.)

  20. Bright-Dark Mixed N-Soliton Solution of Two-Dimensional Multicomponent Maccari System

    Science.gov (United States)

    Han, Zhong; Chen, Yong

    2017-08-01

    Based on the KP hierarchy reduction method, we construct the general bright-dark mixed N-soliton solution of the two-dimensional (2D) (M+1)-component Maccari system comprised of M-component short waves (SWs) and one-component long wave (LW) with all possible combinations of nonlinearities. We firstly consider two types of mixed N-soliton solutions (two-bright-one-dark and one-bright-two-dark solitons in SW components) to the (3+1)-component Maccari system in detail. Then by extending our analysis to the (M+1)-component Maccari system, its general m-bright-(M-m)-dark mixed N-soliton solution is obtained. The formula obtained also contains the general all-bright and all-dark N-soliton solutions as special cases. For the two-bright-one-dark mixed soliton solution of the (3+1)-component Maccari system, it can be shown that solioff excitation and solioff interaction take place in the two SW components supporting bright solitons, whereas the SW component supporting dark solitons and the LW component possess V-type solitary and interaction.

  1. Multiparameter quantum metrology of incoherent point sources: Towards realistic superresolution

    Science.gov (United States)

    Řehaček, J.; Hradil, Z.; Stoklasa, B.; Paúr, M.; Grover, J.; Krzic, A.; Sánchez-Soto, L. L.

    2017-12-01

    We establish the multiparameter quantum Cramér-Rao bound for simultaneously estimating the centroid, the separation, and the relative intensities of two incoherent optical point sources using a linear imaging system. For equally bright sources, the Cramér-Rao bound is independent of their separation, which confirms that the Rayleigh resolution limit is just an artifact of the conventional direct imaging and can be overcome with an adequate strategy. For the general case of unequally bright sources, the amount of information one can gain about the separation falls to zero, but we show that there is always a quadratic improvement in an optimal detection in comparison with the intensity measurements. This advantage can be of utmost importance in realistic scenarios, such as observational astronomy.

  2. Proximal Bright Vessel Sign on Arterial Spin Labeling Magnetic Resonance Imaging in Acute Cardioembolic Cerebral Infarction.

    Science.gov (United States)

    Kato, Ayumi; Shinohara, Yuki; Kuya, Keita; Sakamoto, Makoto; Kowa, Hisanori; Ogawa, Toshihide

    2017-07-01

    The congestion of spin-labeled blood at large-vessel occlusion can present as hyperintense signals on perfusion magnetic resonance imaging with 3-dimensional pseudo-continuous arterial spin labeling (proximal bright vessel sign). The purpose of this study was to clarify the difference between proximal bright vessel sign and susceptibility vessel sign in acute cardioembolic cerebral infarction. Forty-two patients with cardioembolic cerebral infarction in the anterior circulation territory underwent magnetic resonance imaging including diffusion-weighted imaging, 3-dimensional pseudo-continuous arterial spin labeling perfusion magnetic resonance imaging, T2*-weighted imaging, and 3-dimensional time-of-flight magnetic resonance angiography using a 3-T magnetic resonance scanner. Visual assessments of proximal bright vessel sign and the susceptibility vessel sign were performed by consensus of 2 experienced neuroradiologists. The relationship between these signs and the occlusion site of magnetic resonance angiography was also investigated. Among 42 patients with cardioembolic cerebral infarction, 24 patients showed proximal bright vessel sign (57.1%) and 25 showed susceptibility vessel sign (59.5%). There were 19 cases of proximal bright vessel sign and susceptibility vessel sign-clear, 12 cases of proximal bright vessel sign and susceptibility vessel sign-unclear, and 11 mismatched cases. Four out of 6 patients with proximal bright vessel sign-unclear and susceptibility vessel sign-clear showed distal middle cerebral artery occlusion, and 2 out of 5 patients with proximal bright vessel sign-clear and susceptibility vessel sign-unclear showed no occlusion on magnetic resonance angiography. Proximal bright vessel sign is almost compatible with susceptibility vessel sign in patients with cardioembolic cerebral infarction. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  3. Global Derivatives

    DEFF Research Database (Denmark)

    Andersen, Torben Juul

    approaches to dealing in the global business environment." - Sharon Brown-Hruska, Commissioner, Commodity Futures Trading Commission, USA. "This comprehensive survey of modern risk management using derivative securities is a fine demonstration of the practical relevance of modern derivatives theory to risk......""In Global Derivatives: A Strategic Risk Management Perspective", Torben Juul Andersen has succeeded to gather in one book a complete and thorough summary and an easy-to-read explanation of all types of derivative instruments and their background, and their use in modern management of risk......." - Steen Parsholt, Chairman and CEO, Aon Nordic Region. "Andersen has done a wonderful job of developing a comprehensive text that deals with risk management in global markets. I would recommend this book to any student or businessman who has a need to better understand the risks and risk management...

  4. Understanding laser beam brightness: a review and new prospective in material processing

    OpenAIRE

    Shukla, Pratik; Lawrence, Jonathan; Zhang,Yu

    2015-01-01

    This paper details the importance of brightness in relation to laser beams. The ‘brightness’ of lasers is a term that is generally not given much attention in laser applications or in published literature. With this said, it is theoretically and practically an important parameter in laser-material processing. This study is first of a kind which emphasizes in-depth, the concept of brightness of lasers by firstly reviewing the existing literature and the progress with high brightness laser-mate...

  5. Towards non-classical walks with bright laser pulses

    CSIR Research Space (South Africa)

    Sephton, Bereneice C

    2017-08-01

    Full Text Available In the avid search for means to increase computational power in comparison to that which is currently available, quantum walks (QWs) have become a promising option with derived quantum algorithms providing an associated speed up compared to what...

  6. Bright, highly water-soluble triazacyclononane europium complexes to detect ligand binding with time-resolved FRET microscopy.

    Science.gov (United States)

    Delbianco, Martina; Sadovnikova, Victoria; Bourrier, Emmanuel; Mathis, Gérard; Lamarque, Laurent; Zwier, Jurriaan M; Parker, David

    2014-09-26

    Luminescent europium complexes are used in a broad range of applications as a result of their particular emissive properties. The synthesis and application of bright, highly water-soluble, and negatively charged sulfonic- or carboxylic acid derivatives of para-substituted aryl-alkynyl triazacyclononane complexes are described. Introduction of the charged solubilizing moieties suppresses cellular uptake or adsorption to living cells making them applicable for labeling and performing assays on membrane receptors. These europium complexes are applied to monitor fluorescent ligand binding on cell-surface proteins with time-resolved Förster resonance energy transfer (TR-FRET) assays in plate-based format and using TR-FRET microscopy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Robust image region descriptor using local derivative ordinal binary pattern

    Science.gov (United States)

    Shang, Jun; Chen, Chuanbo; Pei, Xiaobing; Liang, Hu; Tang, He; Sarem, Mudar

    2015-05-01

    Binary image descriptors have received a lot of attention in recent years, since they provide numerous advantages, such as low memory footprint and efficient matching strategy. However, they utilize intermediate representations and are generally less discriminative than floating-point descriptors. We propose an image region descriptor, namely local derivative ordinal binary pattern, for object recognition and image categorization. In order to preserve more local contrast and edge information, we quantize the intensity differences between the central pixels and their neighbors of the detected local affine covariant regions in an adaptive way. These differences are then sorted and mapped into binary codes and histogrammed with a weight of the sum of the absolute value of the differences. Furthermore, the gray level of the central pixel is quantized to further improve the discriminative ability. Finally, we combine them to form a joint histogram to represent the features of the image. We observe that our descriptor preserves more local brightness and edge information than traditional binary descriptors. Also, our descriptor is robust to rotation, illumination variations, and other geometric transformations. We conduct extensive experiments on the standard ETHZ and Kentucky datasets for object recognition and PASCAL for image classification. The experimental results show that our descriptor outperforms existing state-of-the-art methods.

  8. Geodesics on Point Clouds

    Directory of Open Access Journals (Sweden)

    Hongchuan Yu

    2014-01-01

    Full Text Available We present a novel framework to compute geodesics on implicit surfaces and point clouds. Our framework consists of three parts, particle based approximate geodesics on implicit surfaces, Cartesian grid based approximate geodesics on point clouds, and geodesic correction. The first two parts can effectively generate approximate geodesics on implicit surfaces and point clouds, respectively. By introducing the geodesic curvature flow, the third part produces smooth and accurate geodesic solutions. Differing from most of the existing methods, our algorithms can converge to a given tolerance. The presented computational framework is suitable for arbitrary implicit hypersurfaces or point clouds with high genus or high curvature.

  9. THE BRIGHTNESS OF THE SKY IN THE VICINITY OF THE SUN

    Science.gov (United States)

    other particles. The study takes into ac count the diffusion of particles from a source of pollution, such as an industrial chimney, and sets limits for the pollution in terms of sky brightness immediately surrounding the sun .

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

    Science.gov (United States)

    Gautam, Sandeep; Adhikari, S. K.

    2018-01-01

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

  11. VOYAGER 1&2 JUPITER BRIGHTNESS NORTH/SOUTH MAP SET V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Voyager 1 and 2 measurements of the brightness of Jupiter at H Lyman alpha and in the H2 Lyman and Werner bands shortward of H Lyman alpha....

  12. Detecting gradual visual changes in colour and brightness agnosia: a double dissociation.

    Science.gov (United States)

    Nijboer, Tanja C W; te Pas, Susan F; van der Smagt, Maarten J

    2011-03-09

    Two patients, one with colour agnosia and one with brightness agnosia, performed a task that required the detection of gradual temporal changes in colour and brightness. The results for these patients, who showed anaverage or an above-average performance on several tasks designed to test low-level colour and luminance (contrast) perception in the spatial domain, yielded a double dissociation; the brightness agnosic patient was within the normal range for the coloured stimuli, but much slower to detect brightness differences, whereas the colour agnosic patient was within the normal range for the achromatic stimuli, but much slower for the coloured stimuli. These results suggest that a modality-specific impairment in the detection of gradual temporal changes might be related to, if not underlie, the phenomenon of visual agnosia.

  13. Nimbus-5/THIR Level 1 Brightness Temperature at 6.7 microns V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nimbus-5 Temperature-Humidity Infrared Radiometer (THIR) Level 1 Brightness Temperature at 6.7 microns data product contains radiances expressed in units of...

  14. Nimbus-5/THIR Level 1 Brightness Temperature at 11.5 microns V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nimbus-5 Temperature-Humidity Infrared Radiometer (THIR) Level 1 Brightness Temperature at 11.5 microns data product contains radiances expressed in units of...

  15. CLPX-Satellite: SSM/I Brightness Temperature Grids, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes Defense Meteorological Satellite Program (DMSP) F-13 passive microwave brightness temperatures gridded to the geographic (lat/long) and UTM...

  16. CLPX-Satellite: AVHRR/HRPT Brightness Temperatures and Reflectances, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes AVHRR/HRPT (Advanced Very High Resolution Radiometer/High Resolution Picture Transmission) brightness temperatures and reflectances over the...

  17. GPM, AMSR2 GCOMW1 Level 1C Common Calibrated Brightness Temperature VV03A

    Data.gov (United States)

    National Aeronautics and Space Administration — 1CAMSR2 contains common calibrated brightness temperature from the AMSR2 passive microwave instrument flown on the GCOMW1 satellite. This products contains 6 swaths....

  18. NOAA Climate Data Record (CDR) of MSU Level 1c Brightness Temperature, Version 1.0

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains Level 1c inter-calibrated brightness temperatures from the Microwave Sounding Unit (MSU) sensors onboard nine polar orbiting satellites...

  19. Analytical brightness compensation algorithm for traditional polygon-based method in computer-generated holography.

    Science.gov (United States)

    Pan, Yijie; Wang, Yongtian; Liu, Juan; Li, Xin; Jia, Jia; Zhang, Zhao

    2013-06-20

    In three-dimensional (3D) holographic display, current brightness compensation algorithm of the traditional polygon-based method experimentally obtains the compensation factor, which depends on the fabrication process. In this paper, we proposed an analytical brightness compensation method discarding the influence of the fabrication. The surface property function with the flat power spectral density and the compensation factor obtained from the simplified relationship between the original and the rotated frequencies are used to analytically compensate the radiant energy of the tilted polygon. The optical reconstruction results show the proposed method could effectively compensate the brightness and ensure the further shading process. The proposed method separates the brightness compensation from the fabrication process, which is important for deepening the investigation of the hologram fabrication and achieving realistic 3D reconstruction.

  20. SMAP L1B Radiometer Half-Orbit Time-Ordered Brightness Temperatures V003

    Data.gov (United States)

    National Aeronautics and Space Administration — Time ordered geolocated H-pol and V-pol brightness temperatures as well as 3rd and 4th Stokes parameters. Each product covers a half orbit with boundaries at the...

  1. DMSP SSM/I-SSMIS Pathfinder Daily EASE-Grid Brightness Temperatures

    Data.gov (United States)

    National Aeronautics and Space Administration — This Level-3 Equal-Area Scalable Earth-Grid (EASE-Grid) Brightness Temperature data set, collected since 09 July 1987, is a part of the NOAA/NASA Pathfinder Program....

  2. Nimbus-6/THIR Level 1 Brightness Temperature at 11.5 microns V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nimbus-6 Temperature-Humidity Infrared Radiometer (THIR) Level 1 Brightness Temperature at 11.5 microns data product contains radiances expressed in units of...

  3. Aquarius L3 Polar-Gridded Weekly Brightness Temperature and Sea Surface Salinity V005

    Data.gov (United States)

    National Aeronautics and Space Administration — The data set consists of weekly gridded Level-3 products of Aquarius L-band radiometer brightness temperature (TB) observations and Sea Surface Salinity (SSS)...

  4. Evaluations of the new LiF-scintillator and optional brightness enhancement films for neutron imaging

    Energy Technology Data Exchange (ETDEWEB)

    Iikura, H., E-mail: Iikura.hiroshi@jaea.go.jp [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki (Japan); Tsutsui, N. [Chichibu Fuji Co., Ltd., Ogano, Chichibu, Saitama 368-0193 (Japan); Nakamura, T.; Katagiri, M.; Kureta, M. [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki (Japan); Kubo, J. [Nissan Motor Co., Ltd., Atsugi, Kanagawa 243-0126 (Japan); Matsubayashi, M. [Japan Atomic Energy Agency, 2-4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki (Japan)

    2011-09-21

    Japan Atomic Energy Agency has developed the neutron scintillator jointly with Chichibu Fuji Co., Ltd. In this study, we evaluated the new ZnS(Ag):Al/{sup 6}Li scintillator developed for neutron imaging. It was confirmed that the brightness increased by about double while maintaining equal performance for the spatial resolution as compared with a conventional scintillator. High frame-rate imaging using a high-speed video camera system and this new scintillator made it possible to image beyond 10 000 frames per second while still having enough brightness. This technique allowed us to obtain a high-frame-rate visualization of oil flow in a running car engine. Furthermore, we devised a technique to increase the light intensity of reception for a camera by adding brightness enhancement films on the output surface of the scintillator. It was confirmed that the spatial resolution degraded more than double, but the brightness increased by about three times.

  5. Evaluations of the new LiF-scintillator and optional brightness enhancement films for neutron imaging

    Science.gov (United States)

    Iikura, H.; Tsutsui, N.; Nakamura, T.; Katagiri, M.; Kureta, M.; Kubo, J.; Matsubayashi, M.

    2011-09-01

    Japan Atomic Energy Agency has developed the neutron scintillator jointly with Chichibu Fuji Co., Ltd. In this study, we evaluated the new ZnS(Ag):Al/ 6Li scintillator developed for neutron imaging. It was confirmed that the brightness increased by about double while maintaining equal performance for the spatial resolution as compared with a conventional scintillator. High frame-rate imaging using a high-speed video camera system and this new scintillator made it possible to image beyond 10 000 frames per second while still having enough brightness. This technique allowed us to obtain a high-frame-rate visualization of oil flow in a running car engine. Furthermore, we devised a technique to increase the light intensity of reception for a camera by adding brightness enhancement films on the output surface of the scintillator. It was confirmed that the spatial resolution degraded more than double, but the brightness increased by about three times.

  6. VOYAGER 1&2 SATURN BRIGHTNESS NORTH/SOUTH MAP SET V1.0

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Voyager 1 and 2 measurements of the brightness of Saturn at H Lyman alpha and in the H2 Lyman and Werner bands shortward of H Lyman alpha....

  7. SMEX03 SSM/I Brightness Temperature Data, Brazil, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides brightness temperature data acquired during the Soil Moisture Experiment 2003 (SMEX03) by the Special Sensor Microwave/Imager (SSM/I).

  8. SMEX02 SSM/I Brightness Temperature Data, Iowa, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides brightness temperature data, acquired during the Soil Moisture Experiment 2002 (SMEX02) by the Special Sensor Microwave/Imagery (SSM/I).

  9. SMEX03 SSM/I Brightness Temperature Data, Oklahoma, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides brightness temperature data acquired during the Soil Moisture Experiment 2003 (SMEX03) by the Special Sensor Microwave/Imager (SSM/I).

  10. Brightness map of the zodiacal emission from the AKARI IRC All-Sky Survey

    Science.gov (United States)

    Pyo, J.; Ueno, M.; Kwon, S. M.; Hong, S. S.; Ishihara, D.; Ishiguro, M.; Usui, F.; Ootsubo, T.; Mukai, T.

    2010-11-01

    The first Japanese infrared space mission AKARI successfully scanned the whole sky with its two main instruments, the Infrared Camera (IRC) and the Far-Infrared Surveyor (FIS). The AKARI All-Sky Survey provides us with an invaluable opportunity to examine the zodiacal emission (ZE) over the entire sky in the leading as well as the trailing direction of the Earth's motion. We describe our efforts to reduce the ZE brightness map from the AKARI's survey in the 9 μm waveband. Compared with the interplanetary dust cloud model of Kelsall et al. (1998), the map requires an increase of the contribution of the resonance ring component to the ZE brightness by about 20%. We paid special attention to the north and south ecliptic pole brightnesses. The symmetry plane's inclination and longitude of ascending node need to be modified from those in Kelsall et al. (1998) to reach a best fit to the observed pole brightness difference.

  11. Utilizing typical color appearance models to represent perceptual brightness and colorfulness for digital images

    Science.gov (United States)

    Gong, Rui; Wang, Qing; Shao, Xiaopeng; Zhou, Conghao

    2016-12-01

    This study aims to expand the applications of color appearance models to representing the perceptual attributes for digital images, which supplies more accurate methods for predicting image brightness and image colorfulness. Two typical models, i.e., the CIELAB model and the CIECAM02, were involved in developing algorithms to predict brightness and colorfulness for various images, in which three methods were designed to handle pixels of different color contents. Moreover, massive visual data were collected from psychophysical experiments on two mobile displays under three lighting conditions to analyze the characteristics of visual perception on these two attributes and to test the prediction accuracy of each algorithm. Afterward, detailed analyses revealed that image brightness and image colorfulness were predicted well by calculating the CIECAM02 parameters of lightness and chroma; thus, the suitable methods for dealing with different color pixels were determined for image brightness and image colorfulness, respectively. This study supplies an example of enlarging color appearance models to describe image perception.

  12. Nimbus-6/THIR Level 1 Brightness Temperature at 6.7 microns V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The Nimbus-6 Temperature-Humidity Infrared Radiometer (THIR) Level 1 Brightness Temperature at 6.7 microns data product contains radiances expressed in units of...

  13. GPM, AMSR2 GCOMW1 Level 1C Common Calibrated Brightness Temperature V03

    Data.gov (United States)

    National Aeronautics and Space Administration — 1CAMSR2 contains common calibrated brightness temperature from the AMSR2 passive microwave instrument flown on the GCOMW1 satellite. This products contains 6 swaths....

  14. GPM, AMSR2 GCOMW1 Level 1C Common Calibrated Brightness Temperature VV02A

    Data.gov (United States)

    National Aeronautics and Space Administration — 1CAMSR2 contains common calibrated brightness temperature from the AMSR2 passive microwave instrument flown on the GCOMW1 satellite. This products contains 6 swaths....

  15. SMEX02 AMSR-E Level 3 Daily Gridded Brightness Temperatures, Iowa

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) level 3 daily gridded brightness temperatures, spatially subsetted to...

  16. Electricity derivatives

    CERN Document Server

    Aïd, René

    2015-01-01

    Offering a concise but complete survey of the common features of the microstructure of electricity markets, this book describes the state of the art in the different proposed electricity price models for pricing derivatives and in the numerical methods used to price and hedge the most prominent derivatives in electricity markets, namely power plants and swings. The mathematical content of the book has intentionally been made light in order to concentrate on the main subject matter, avoiding fastidious computations. Wherever possible, the models are illustrated by diagrams. The book should allow prospective researchers in the field of electricity derivatives to focus on the actual difficulties associated with the subject. It should also offer a brief but exhaustive overview of the latest techniques used by financial engineers in energy utilities and energy trading desks.

  17. Observations of copolar correlation coefficient through a bright band at vertical incidence

    Science.gov (United States)

    Zrnic, D. S.; Raghavan, R.; Chandrasekar, V.

    1994-01-01

    This paper discusses an application of polarimetric measurements at vertical incidence. In particular, the correlation coefficients between linear copolar components are examined, and measurements obtained with the National Severe Storms Laboratory (NSSL)'s and National Center for Atmospheric Research (NCAR)'s polarimetric radars are presented. The data are from two well-defined bright bands. A sharp decrease of the correlation coefficient, confined to a height interval of a few hundred meters, marks the bottom of the bright band.

  18. Brightness Temperatures of Saturn's Disk and Rings at 400 and 700 Micrometers.

    Science.gov (United States)

    Whitcomb, S E; Hildebrand, R H; Keene, J

    1980-11-14

    Saturn was observed in two broad submillimeter photometric bands with the rings nearly edge-on. The observed brightness temperatures fall below the predictions of atmospheric models constructed from data at shorter wavelenths, indicating the presence of an opacity source besides pressure-broadened hydrogen lines in the submillimeter region. In combination with earlier measurements at larger inclination angles, these results yield a 400-micrometer brightness temperature for the rings of approximately 75 K.

  19. Dawn simulation vs. bright light in seasonal affective disorder: Treatment effects and subjective preference.

    Science.gov (United States)

    Danilenko, K V; Ivanova, I A

    2015-07-15

    Studies comparing the efficacy of dawn simulation to conventional bright light for the treatment of seasonal affective disorder (in parallel groups) have yielded conflicting results. This crossover study investigated treatment outcomes and long-term treatment preference. Forty winter depressives were treated for a week with bright light (4.300lx for 30-45min shortly after awakening) or dawn simulation (gradually increasing light during the last 30min of sleep achieving 100lx before alarm beep, with the dawn simulator placed closer to the open eyes for a further 15min: 250lx). The depression level was self-rated using SIGH-SAD-SR. Depression scores reduced similarly following bright light and dawn simulation: for 43.8% and 42.2% (medians), respectively; efficacy ratio was 23:17. The preference was also similar (21:19). Among those who preferred bright light, the most common reason was that they perceived the bright light to be more effective (19/21; it was more effective, p=0.0096; this subgroup tended to have more severe depression) and ease of use (6/21). Among those who preferred the dawn simulator, the reasons were a more "natural" action (9/19), device compactness and/or time-saving (10/19) and in 4 cases where bright light caused eyestrain. Not overhead naturalistic light for dawn simulation, self-rating of depression. Dawn simulation is similarly effective to bright light in the treatment of winter depression. Patients with more severe depression tended to report greater improvement with bright light; in such cases, this would outweigh the non-clinical advantages of dawn simulation. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Improvement in Fatigue, Sleepiness, and Health-Related Quality of Life with Bright Light Treatment in Persons with Seasonal Affective Disorder and Subsyndromal SAD.

    Science.gov (United States)

    Rastad, Cecilia; Ulfberg, Jan; Lindberg, Per

    2011-01-01

    Objective. To investigate the effects of bright light treatment for secondary outcome measures and to explore and validate empirically derived subgroups and treatment effects in subgroups. Methods. A descriptive design. A sample of forty-nine persons (mean age of 45.8) with clinically assessed seasonal affective disorder (SAD) or subsyndromal SAD (S-SAD) participated in a two-group clinical trial evaluating the effects of treatment with bright light therapy. A person-oriented cluster analysis was applied to study treatment effects in subgroups. Results. For the merged group, sleepiness (Epworth Sleepiness Scale), fatigue (fatigue questionnaire), and health-related quality of life (SF-36) were improved at posttreatment, and results were maintained at the one-month followup. Three distinct subgroups had a high level of fatigue in common, while the level of excessive daytime sleepiness and depressed mood differed between the subgroups. Over time, all subgroups improved following ten days treatment in a light room. Conclusion. Fatigue, excessive daytime sleepiness, and health-related quality of life improve in a similar way as depressed mood following treatment with bright light. The treatment was effective irrespective of the severity of the disorder, that is, for persons with SAD and subsyndromal SAD.

  1. Improvement in Fatigue, Sleepiness, and Health-Related Quality of Life with Bright Light Treatment in Persons with Seasonal Affective Disorder and Subsyndromal SAD

    Science.gov (United States)

    Rastad, Cecilia; Ulfberg, Jan; Lindberg, Per

    2011-01-01

    Objective. To investigate the effects of bright light treatment for secondary outcome measures and to explore and validate empirically derived subgroups and treatment effects in subgroups. Methods. A descriptive design. A sample of forty-nine persons (mean age of 45.8) with clinically assessed seasonal affective disorder (SAD) or subsyndromal SAD (S-SAD) participated in a two-group clinical trial evaluating the effects of treatment with bright light therapy. A person-oriented cluster analysis was applied to study treatment effects in subgroups. Results. For the merged group, sleepiness (Epworth Sleepiness Scale), fatigue (fatigue questionnaire), and health-related quality of life (SF-36) were improved at posttreatment, and results were maintained at the one-month followup. Three distinct subgroups had a high level of fatigue in common, while the level of excessive daytime sleepiness and depressed mood differed between the subgroups. Over time, all subgroups improved following ten days treatment in a light room. Conclusion. Fatigue, excessive daytime sleepiness, and health-related quality of life improve in a similar way as depressed mood following treatment with bright light. The treatment was effective irrespective of the severity of the disorder, that is, for persons with SAD and subsyndromal SAD. PMID:21747994

  2. Improvement in Fatigue, Sleepiness, and Health-Related Quality of Life with Bright Light Treatment in Persons with Seasonal Affective Disorder and Subsyndromal SAD

    Directory of Open Access Journals (Sweden)

    Cecilia Rastad

    2011-01-01

    Full Text Available Objective. To investigate the effects of bright light treatment for secondary outcome measures and to explore and validate empirically derived subgroups and treatment effects in subgroups. Methods. A descriptive design. A sample of forty-nine persons (mean age of 45.8 with clinically assessed seasonal affective disorder (SAD or subsyndromal SAD (S-SAD participated in a two-group clinical trial evaluating the effects of treatment with bright light therapy. A person-oriented cluster analysis was applied to study treatment effects in subgroups. Results. For the merged group, sleepiness (Epworth Sleepiness Scale, fatigue (fatigue questionnaire, and health-related quality of life (SF-36 were improved at posttreatment, and results were maintained at the one-month followup. Three distinct subgroups had a high level of fatigue in common, while the level of excessive daytime sleepiness and depressed mood differed between the subgroups. Over time, all subgroups improved following ten days treatment in a light room. Conclusion. Fatigue, excessive daytime sleepiness, and health-related quality of life improve in a similar way as depressed mood following treatment with bright light. The treatment was effective irrespective of the severity of the disorder, that is, for persons with SAD and subsyndromal SAD.

  3. Nickel Curie Point Engine

    Science.gov (United States)

    Chiaverina, Chris; Lisensky, George

    2014-01-01

    Ferromagnetic materials such as nickel, iron, or cobalt lose the electron alignment that makes them attracted to a magnet when sufficient thermal energy is added. The temperature at which this change occurs is called the "Curie temperature," or "Curie point." Nickel has a Curie point of 627 K, so a candle flame is a sufficient…

  4. Model Breaking Points Conceptualized

    Science.gov (United States)

    Vig, Rozy; Murray, Eileen; Star, Jon R.

    2014-01-01

    Current curriculum initiatives (e.g., National Governors Association Center for Best Practices and Council of Chief State School Officers 2010) advocate that models be used in the mathematics classroom. However, despite their apparent promise, there comes a point when models break, a point in the mathematical problem space where the model cannot,…

  5. Holographic Three point Functions

    DEFF Research Database (Denmark)

    Bissi, Agnese

    gravitons and a point like graviton and its dual counterpart, namely two Schur polynomials and a single trace chiral primary. Secondly we compute the one loop correction to planar, non extremal three point functions of two heavy and one light operators, both from the gauge and string side in the Frolov...

  6. Point of View.

    Science.gov (United States)

    Davis, Jonathan; Davis, Lisa

    1999-01-01

    Presents a learning activity plan for teachers or librarians that helps students comprehend the author's craft element of "point of view." Focus is on first and third person point of view. Outlines student motivation methods, the procedure, extension/application activities, and assessment. Includes an activity worksheet. (AEF)

  7. Bright pituitary stalk on MR T1-weighted image. Damming up phenomenon of the neurosecretory granules

    Energy Technology Data Exchange (ETDEWEB)

    Fujisawa, Ichiro; Uokawa, Kyosuke; Horii, Naotoshi; Murakami, Norihiko; Azuma, Nobuyuki; Furuto-Kato, Sumiko; Yamashita, Kohsuke; Nakao, Satoshi; Kageyama, Naoki [Kishiwada City Hospital, Osaka (Japan)

    2002-04-01

    Characteristic findings of the pituitary stalk on magnetic resonance (MR) imaging, which suggest a damming-up phenomenon of neurosecretory granules, were reported. Neurosecretory granules containing vasopressin influence the signal intensity on MR T1-weighted image (T1WI). The normal posterior lobe of the pituitary gland appears as a bright signal on T1WI. The bright signal of the posterior lobe represents the normal content of neurosecretory granules and disappears in patients with central diabetes insipidus. The normal pituitary stalk appears as a low-intermediate intensity signal on sagittal and coronal T1WIs with 3 mm-slice thickness. The pituitary stalk appeared as a bright signal in 20 patients; 13 with pituitary adenoma, 4 with an intrasellar cystic lesion, one with cavernous sinus mass, and 2 with no abnormal MR findings. The pituitary stalk was not severed in any of the cases. The normal bright signal of the posterior lobe disappeared in 17 patients. No patients suffered from symptoms of central diabetes insipidus when the bright pituitary stalk appeared. It is suggested that the origin of the bright signal in the pituitary stalk is the damming up and accumulation of neurosecretory granules in the nerve fibers of the hypothalamohypophyseal tract obstructed by adenoma, postoperative scarring, cystic mass and so on. Probably, the damming-up phenomenon on MR imaging represents the functional integrity of the hypothalamo-neurohypophyseal system, and should be distinguished from an ectopic posterior lobe formation which is caused by stalk transection. (author)

  8. Brightness induction by local contrast and the spatial dependence of assimilation.

    Science.gov (United States)

    Reid, R C; Shapley, R

    1988-01-01

    Two mechanisms of brightness perception (1) brightness induction by local contrast and (2) assimilation, were examined for a variety of visual stimuli. Local contrast is the primary determinant of brightness perception, making objects appear brighter on a background of lower luminance and darker on a background of greater luminance. Assimilation is the opposite effect, whereby objects on a brighter (but not necessarily more luminant) background appear brighter or on a dark background appear darker. We have compared the relative strength of the two effects using stimuli which permit them to be studied separately. Brightness induction by local contrast is quantitatively stronger in all situations. Further, the strength of assimilation is strongly dependent on spatial parameters in the visual scene. These results are shown to be true both for simple visual stimuli as well as for complicated Mondrian-like patterns. The Retinex theory of brightness perception predicts that the two effects are equal. Our results show a range of relative strengths (assimilation vs brightness induction due to contrast) from 0.59 to 0.63 at 5' down to 0.34 at 43'.

  9. Effect of fungal pre-treatment of poplar chips on its paper brightness reversion

    Directory of Open Access Journals (Sweden)

    Esmaeil Rasooly Garmaroody

    2017-02-01

    Full Text Available Unbleached Kraft pulp made from poplar chips, Pre-treated by Trametes versicolor in 1, 2 and 3 weeks (Bio-Kraft pulp, was used as raw material in this study. Mentioned pulp after each step of bleaching, in ECF method at DED sequence, characterized in the lignin content, and effective groups on the brightness reversion (Carbonyl, carboxyl and Hexenuronic acid. In order to evaluation of brightness reversion, 60 g/m2 standard handsheets made from above pulps treated in thermal and UV ageing and then measured its brightness. Results showed that by increasing in pre-treatment time, in all bleached treatments, lignin content increased excluding D1 step in 3-weeks pre-treatment; Carbonyl groups was the lowest content in 1-week pre-treatment (third step and 2-weeks pre-treatment (first step and carboxyl groups and hexenuronic acid decreased after 3 step sequence bleaching. Effect of thermal pre-treatment ageing on brightness reversion considerably more than UV treatment. Also, paper from pre-treated chips in 1 and 2 weeks had minimum brightness reversion and paper from 3-weeks fungal pre-treatment chips had maximum brightness reversion due to more carbonyl and Hex-A. In this respect, 2-weeks pre-treatment time confirmed for fungal pre-treatment.

  10. Colors and Photometry of Bright Materials on Vesta as Seen by the Dawn Framing Camera

    Science.gov (United States)

    Schroeder, S. E.; Li, J.-Y.; Mittlefehldt, D. W.; Pieters, C. M.; De Sanctis, M. C.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.; Keller, H. U.; hide

    2012-01-01

    The Dawn spacecraft has been in orbit around the asteroid Vesta since July, 2011. The on-board Framing Camera has acquired thousands of high-resolution images of the regolith-covered surface through one clear and seven narrow-band filters in the visible and near-IR wavelength range. It has observed bright and dark materials that have a range of reflectance that is unusually wide for an asteroid. Material brighter than average is predominantly found on crater walls, and in ejecta surrounding caters in the southern hemisphere. Most likely, the brightest material identified on the Vesta surface so far is located on the inside of a crater at 64.27deg S, 1.54deg . The apparent brightness of a regolith is influenced by factors such as particle size, mineralogical composition, and viewing geometry. As such, the presence of bright material can indicate differences in lithology and/or degree of space weathering. We retrieve the spectral and photometric properties of various bright terrains from false-color images acquired in the High Altitude Mapping Orbit (HAMO). We find that most bright material has a deeper 1-m pyroxene band than average. However, the aforementioned brightest material appears to have a 1-m band that is actually less deep, a result that awaits confirmation by the on-board VIR spectrometer. This site may harbor a class of material unique for Vesta. We discuss the implications of our spectral findings for the origin of bright materials.

  11. Assimilation of SMOS Brightness Temperatures or Soil Moisture Retrievals into a Land Surface Model

    Science.gov (United States)

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

    2016-01-01

    Three different data products from the Soil Moisture Ocean Salinity (SMOS) mission are assimilated separately into the Goddard Earth Observing System Model, version 5 (GEOS-5) to improve estimates of surface and root-zone soil moisture. The first product consists of multi-angle, dual-polarization brightness temperature (Tb) observations at the bottom of the atmosphere extracted from Level 1 data. The second product is a derived SMOS Tb product that mimics the data at a 40 degree incidence angle from the Soil Moisture Active Passive (SMAP) mission. The third product is the operational SMOS Level 2 surface soil moisture (SM) retrieval product. The assimilation system uses a spatially distributed ensemble Kalman filter (EnKF) with seasonally varying climatological bias mitigation for Tb assimilation, whereas a time-invariant cumulative density function matching is used for SM retrieval assimilation. All assimilation experiments improve the soil moisture estimates compared to model-only simulations in terms of unbiased root-mean-square differences and anomaly correlations during the period from 1 July 2010 to 1 May 2015 and for 187 sites across the US. Especially in areas where the satellite data are most sensitive to surface soil moisture, large skill improvements (e.g., an increase in the anomaly correlation by 0.1) are found in the surface soil moisture. The domain-average surface and root-zone skill metrics are similar among the various assimilation experiments, but large differences in skill are found locally. The observation-minus-forecast residuals and analysis increments reveal large differences in how the observations add value in the Tb and SM retrieval assimilation systems. The distinct patterns of these diagnostics in the two systems reflect observation and model errors patterns that are not well captured in the assigned EnKF error parameters. Consequently, a localized optimization of the EnKF error parameters is needed to further improve Tb or SM retrieval

  12. Assimilation of SMOS brightness temperatures or soil moisture retrievals into a land surface model

    Science.gov (United States)

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

    2016-12-01

    Three different data products from the Soil Moisture Ocean Salinity (SMOS) mission are assimilated separately into the Goddard Earth Observing System Model, version 5 (GEOS-5) to improve estimates of surface and root-zone soil moisture. The first product consists of multi-angle, dual-polarization brightness temperature (Tb) observations at the bottom of the atmosphere extracted from Level 1 data. The second product is a derived SMOS Tb product that mimics the data at a 40° incidence angle from the Soil Moisture Active Passive (SMAP) mission. The third product is the operational SMOS Level 2 surface soil moisture (SM) retrieval product. The assimilation system uses a spatially distributed ensemble Kalman filter (EnKF) with seasonally varying climatological bias mitigation for Tb assimilation, whereas a time-invariant cumulative density function matching is used for SM retrieval assimilation. All assimilation experiments improve the soil moisture estimates compared to model-only simulations in terms of unbiased root-mean-square differences and anomaly correlations during the period from 1 July 2010 to 1 May 2015 and for 187 sites across the US. Especially in areas where the satellite data are most sensitive to surface soil moisture, large skill improvements (e.g., an increase in the anomaly correlation by 0.1) are found in the surface soil moisture. The domain-average surface and root-zone skill metrics are similar among the various assimilation experiments, but large differences in skill are found locally. The observation-minus-forecast residuals and analysis increments reveal large differences in how the observations add value in the Tb and SM retrieval assimilation systems. The distinct patterns of these diagnostics in the two systems reflect observation and model errors patterns that are not well captured in the assigned EnKF error parameters. Consequently, a localized optimization of the EnKF error parameters is needed to further improve Tb or SM retrieval

  13. Bright Metal-Poor Stars from the Hamburg/ESO Survey. II. A Chemodynamical Analysis

    Science.gov (United States)

    Beers, Timothy C.; Placco, Vinicius M.; Carollo, Daniela; Rossi, Silvia; Lee, Young Sun; Frebel, Anna; Norris, John E.; Dietz, Sarah; Masseron, Thomas

    2017-01-01

    We obtain estimates of stellar atmospheric parameters for a previously published sample of 1777 relatively bright (9Hamburg/ESO Survey. The original Frebel et al. analysis of these stars was able to derive estimates of [Fe/H] and [C/Fe] only for a subset of the sample, due to limitations in the methodology then available. A new spectroscopic analysis pipeline has been used to obtain estimates of {T}{eff}, {log} g, [Fe/H], and [C/Fe] for almost the entire data set. This sample is very local—about 90% of the stars are located within 0.5 kpc of the Sun. We consider the chemodynamical properties of these stars in concert with a similarly local sample of stars from a recent analysis of the Bidelman and MacConnell “weak metal” candidates by Beers et al. We use this combined sample to identify possible members of the halo stream of stars suggested by Helmi et al. and Chiba & Beers, as well as stars that may be associated with stripped debris from the putative parent dwarf of the globular cluster Omega Centauri, suggested to exist by previous authors. We identify a clear increase in the cumulative frequency of carbon-enhanced metal-poor (CEMP) stars with declining metallicity, as well as an increase in the fraction of CEMP stars with distance from the Galactic plane, consistent with previous results. We also identify a relatively large number of CEMP stars with kinematics consistent with the metal-weak thick-disk population, with possible implications for its origin.

  14. The AGN and gas disc in the low surface brightness galaxy PGC045080

    Science.gov (United States)

    Das, M.; Kantharia, N.; Ramya, S.; Prabhu, T. P.; McGaugh, S. S.; Vogel, S. N.

    2007-07-01

    We present radio observations and optical spectroscopy of the giant low surface brightness (LSB) galaxy PGC045080 (or 1300+0144). PGC045080 is a moderately distant galaxy having a highly inclined optical disc and massive HI gas content. Radio continuum observations of the galaxy were carried out at 320, 610MHz and 1.4GHz. Continuum emission was detected and mapped in the galaxy. The emission appears extended over the inner disc at all three frequencies. At 1.4GHz and 610MHz it appears to have two distinct lobes. We also did optical spectroscopy of the galaxy nucleus; the spectrum did not show any strong emission lines associated with active galactic nucleus (AGN) activity but the presence of a weak AGN cannot be ruled out. Furthermore, comparison of the Hα flux and radio continuum at 1.4GHz suggests that a significant fraction of the emission is non-thermal in nature. Hence we conclude that a weak or hidden AGN may be present in PGC045080. The extended radio emission represents lobes/jets from the AGN. These observations show that although LSB galaxies are metal poor and have very little star formation, their centres can host significant AGN activity. We also mapped the HI gas disc and velocity field in PGC045080. The HI disc extends well beyond the optical disc and appears warped. In the HI intensity maps, the disc appears distinctly lopsided. The velocity field is disturbed on the lopsided side of the disc but is fairly uniform in the other half. We derived the HI rotation curve for the galaxy from the velocity field. The rotation curve has a flat rotation speed of ~190kms-1.

  15. Fluorescence properties of 6-aryl-2‧-deoxy-furanouridine and –pyrrolocytidine and their derivatives

    Science.gov (United States)

    Ro, Jong Jin; Go, Gui Han; Wilhelmsson, L. Marcus; Hyean Kim, Byeang

    2018-01-01

    2‧-deoxyfuranouridine derivatives presenting various aryl groups have been synthesized through Cu(I)-catalyzed intramolecular cyclizations. Moreover, corresponding pyrrolo-dC derivatives have been synthesized and both families of compounds thoroughly characterized using UV/vis and fluorescence spectroscopy as well as time-dependent density functional theory calculations. The photophysical characterization, show that our newly synthesized derivatives of the important pyrrolo-dC family have high fluorescence quantum yields (QYs) and brightness values. Pyrrolo-dC derivative, 3a, shows an environment sensitive QY of up to >60% and brightness of almost 3000, in low polarity solvents and excitation and emission maxima between 365–381 nm and 479–510 nm, respectively, in solvents of different polarities. Two other derivatives, 3b and 3c, show high QYs and brightness values of up to 3300 that are fairly insensitive to their microenvironment. These promising photophysical features suggest future applicability as fluorescent nucleobase analogs.

  16. Complex derivatives

    Science.gov (United States)

    Battiston, Stefano; Caldarelli, Guido; Georg, Co-Pierre; May, Robert; Stiglitz, Joseph

    2013-03-01

    The intrinsic complexity of the financial derivatives market has emerged as both an incentive to engage in it, and a key source of its inherent instability. Regulators now faced with the challenge of taming this beast may find inspiration in the budding science of complex systems.

  17. Relationship between flash points of some binary base oils and their constituent oils

    Directory of Open Access Journals (Sweden)

    M. Shirani

    2015-07-01

    Full Text Available Miscellaneous binary blends containing solvent neutral-150 (SN-150, solvent neutral-500 (SN-500, Bright Stock-150 (BS-150, polyalphaolephin-6 (PAO-6, PAO-100, a processed low sulfur waxy material, and polyisobutene-600 (PIB-600 were prepared and their corresponding flash point (FP were measured. By using the measured FP data, the plots of FP vs. weight percentage of minor component were drawn and the equations due to each plot were derived. Except PIB-600 containing mixtures, linear relation between FP of blends and weight percentage of constituents has been observed. Also the obtained data indicate that except PIB-600 containing blends the FP of such mixtures can be calculated from the summation of "FP × weight ratio" of each component. In the case of PIB-600 containing blends, nonlinear and decreasing, nonlinear and increasing were observed as well as constant trends of FP vs. weight percentage of minor component. The observations have been interpreted based on the composition, molecular weight, and interactions of the constituents of the base oils.

  18. CHARACTERIZING THE POPULATION OF BRIGHT INFRARED SOURCES IN THE SMALL MAGELLANIC CLOUD

    Energy Technology Data Exchange (ETDEWEB)

    Kraemer, K. E. [Institute for Scientific Research, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467 (United States); Sloan, G. C. [Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY 14853-6801 (United States); Wood, P. R. [Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston Creek ACT 2611 (Australia); Jones, O. C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Egan, M. P., E-mail: kathleen.kraemer@bc.edu, E-mail: sloan@astro.cornell.edu, E-mail: wood@mso.anu.edu.au, E-mail: michael.p.egan@nga.mil [National Geospatial Intelligence Agency, 7500 GEOINT Drive, Springfield, VA 22150 (United States)

    2017-01-10

    We have used the Infrared Spectrograph (IRS) on the Spitzer Space Telescope to observe stars in the Small Magellanic Cloud (SMC) selected from the Point Source Catalog of the Midcourse Space Experiment (MSX). We concentrate on the dust properties of the oxygen-rich evolved stars. The dust composition has smaller contributions from alumina compared to the Galaxy. This difference may arise from the lower metallicity in the SMC, but it could be a selection effect, as the SMC sample includes more stars that are brighter and thus more massive. The distribution of the SMC stars along the silicate sequence looks more like the Galactic sample of red supergiants than asymptotic giant branch stars (AGBs). While many of the SMC stars are definitively on the AGB, several also show evidence of hot bottom burning. Three of the supergiants show PAH emission at 11.3 μ m. Two other sources show mixed chemistry, with both carbon-rich and oxygen-rich spectral features. One, MSX SMC 134, may be the first confirmed silicate/carbon star in the SMC. The other, MSX SMC 049, is a candidate post-AGB star. MSX SMC 145, previously considered a candidate OH/IR star, is actually an AGB star with a background galaxy at z  = 0.16 along the same line of sight. We consider the overall characteristics of all the MSX sources, the most infrared-bright objects in the SMC, in light of the higher sensitivity and resolution of Spitzer , and compare them with the object types expected from the original selection criteria. This population represents what will be seen in more distant galaxies by the upcoming James Webb Space Telescope ( JWST ). Color–color diagrams generated from the IRS spectra and the mid-infrared filters on JWST show how one can separate evolved stars from young stellar objects (YSOs) and distinguish among different classes of YSOs.

  19. Point Information Gain and Multidimensional Data Analysis

    Directory of Open Access Journals (Sweden)

    Renata Rychtáriková

    2016-10-01

    Full Text Available We generalize the point information gain (PIG and derived quantities, i.e., point information gain entropy (PIE and point information gain entropy density (PIED, for the case of the Rényi entropy and simulate the behavior of PIG for typical distributions. We also use these methods for the analysis of multidimensional datasets. We demonstrate the main properties of PIE/PIED spectra for the real data with the examples of several images and discuss further possible utilizations in other fields of data processing.

  20. Interesting Interest Points

    DEFF Research Database (Denmark)

    Aanæs, Henrik; Dahl, Anders Lindbjerg; Pedersen, Kim Steenstrup

    2012-01-01

    Not all interest points are equally interesting. The most valuable interest points lead to optimal performance of the computer vision method in which they are employed. But a measure of this kind will be dependent on the chosen vision application. We propose a more general performance measure based...... position. The LED illumination provides the option for artificially relighting the scene from a range of light directions. This data set has given us the ability to systematically evaluate the performance of a number of interest point detectors. The highlights of the conclusions are that the fixed scale...

  1. Do acupuncture points exist?

    Energy Technology Data Exchange (ETDEWEB)

    Yan Xiaohui; Zhang Xinyi [Department of Physics, Surface Physics Laboratory (State Key Laboratory), and Synchrotron Radiation Research Center of Fudan University, Shanghai 200433 (China); Liu Chenglin [Physics Department of Yancheng Teachers' College, Yancheng 224002 (China); Dang, Ruishan [Second Military Medical University, Shanghai 200433 (China); Huang Yuying; He Wei [Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039 (China); Ding Guanghong [Shanghai Research Center of Acupuncture and Meridian, Pudong, Shanghai 201203 (China)

    2009-05-07

    We used synchrotron x-ray fluorescence analysis to probe the distribution of four chemical elements in and around acupuncture points, two located in the forearm and two in the lower leg. Three of the four acupuncture points showed significantly elevated concentrations of elements Ca, Fe, Cu and Zn in relation to levels in the surrounding tissue, with similar elevation ratios for Cu and Fe. The mapped distribution of these elements implies that each acupuncture point seems to be elliptical with the long axis along the meridian. (note)

  2. Pillar[5]arenes: fascinating cyclophanes with a bright future.

    Science.gov (United States)

    Cragg, Peter J; Sharma, Kushal

    2012-01-21

    Pillar[5]arenes are [1(5)]paracyclophane derivatives consisting of 1,4-disubstituted hydroquinones linked by methylene bridges in the 2,5-positions. The first report of these novel macrocycles was in 2008, when 1,4-dimethoxypillar[5]arene was prepared in 22% yield, and subsequent improvements in synthetic methods have allowed the number of derivatives to expand significantly. In addition to D(5) symmetric pillar[5]arenes, asymmetric pillar[5]arenes with two different substituents in the 1- and 4-positions and copillar[5]arenes consisting of two different repeat units in a 4 : 1 ratio have been synthesised. Crystallographic, computational and spectroscopic studies are starting to shed light on the compounds' unusual inclusion phenomena, from gelation and transportation of water through nanotubes to the formation of chromogenic rotaxanes. Applications as molecular sensors are starting to appear with a focus on guest detection by fluorescence quenching. This tutorial review will provide a summary of research into the pillar[5]arenes since their recent discovery.

  3. High Brightness Electron Gun for X-Ray Source

    CERN Document Server

    Ohsawa, Satoshi; Ikeda, Mitsuo; Kanno, K; Sugimura, Takashi; Tawada, Masafumi

    2005-01-01

    A new electron-gun system is under development in order to increase X-ray from a rotating target. In commercial X-ray sources electron beams usually hit targets at the outer part. Owing to deformation by centrifugal force, there has been a limit on electron beam intensities. In order to overcome this difficulty, we adopted a new injection system which strikes inside of a ring-shape projection on a rotating target. It has an advantage in that heated-up points have supports back side against centrifugal force. This merit allows us to raise electron beam to give stronger X-rays.

  4. Fermi Large Area Telescope Bright Gamma-ray Source List

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, Aous A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; /KIPAC, Menlo Park /SLAC; Ajello, M.; /KIPAC, Menlo Park /SLAC; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U., OKC /Stockholm U.; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Band, D.L.; /NASA, Goddard /NASA, Goddard; Barbiellini, Guido; /INFN, Trieste /Trieste U.; Bastieri, Denis; /INFN, Padua /Padua U.; Bechtol, K.; /KIPAC, Menlo Park /SLAC; Bellazzini, R.; /INFN, Pisa; Berenji, B.; /KIPAC, Menlo Park /SLAC; Bignami, G.F.; /Pavia U.; Bloom, Elliott D.; /KIPAC, Menlo Park /SLAC; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /KIPAC, Menlo Park /SLAC; Bregeon, J.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Burnett, Thompson H.; /Washington U., Seattle /Bari U. /INFN, Bari /KIPAC, Menlo Park /SLAC /IASF, Milan /IASF, Milan /DAPNIA, Saclay /ASDC, Frascati /INFN, Perugia /Perugia U. /KIPAC, Menlo Park /SLAC /George Mason U. /Naval Research Lab, Wash., D.C. /NASA, Goddard /KIPAC, Menlo Park /SLAC /INFN, Perugia /Perugia U. /KIPAC, Menlo Park /SLAC /Montpellier U. /Sonoma State U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Stockholm U. /KIPAC, Menlo Park /SLAC /ASDC, Frascati /NASA, Goddard /Maryland U. /Naval Research Lab, Wash., D.C. /INFN, Trieste /Pavia U. /Bari U. /INFN, Bari /KIPAC, Menlo Park /SLAC /UC, Santa Cruz /KIPAC, Menlo Park /SLAC /KIPAC, Menlo Park /SLAC /KIPAC, Menlo Park /SLAC /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /NASA, Goddard; /more authors..

    2009-05-15

    Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope (Fermi) began a sky survey in August. The Large Area Telescope (LAT) on Fermi in three months produced a deeper and better resolved map of the {gamma}-ray sky than any previous space mission. We present here initial results for energies above 100 MeV for the 205 most significant (statistical significance greater than {approx}10{sigma}) {gamma}-ray sources in these data. These are the best characterized and best localized point-like (i.e., spatially unresolved) {gamma}-ray sources in the early mission data.

  5. An Inter-calibrated Passive Microwave Brightness Temperature Data Record and Ocean Products

    Science.gov (United States)

    Hilburn, K. A.; Wentz, F. J.

    2014-12-01

    Inter-calibration of passive microwave sensors has been the subject of on-going activity at Remote Sensing Systems (RSS) since 1974. RSS has produced a brightness temperature TB data record that spans the last 28 years (1987-2014) from inter-calibrated passive microwave sensors on 14 satellites: AMSR-E, AMSR2, GMI, SSMI F08-F15, SSMIS F16-F18, TMI, WindSat. Accompanying the TB record are a suite of ocean products derived from the TBs that provide a 28-year record of wind speed, water vapor, cloud liquid, and rain rate; and 18 years (1997-2014) of sea surface temperatures, corresponding to the period for which 6 and/or 10 GHz measurements are available. Crucial to the inter-calibration and ocean product retrieval are a highly accurate radiative transfer model RTM. The RSS RTM has been continually refined for over 30 years and is arguably the most accurate model in the 1-100 GHz spectrum. The current generation of TB and ocean products, produced using the latest version of the RTM, is called Version-7. The accuracy of the Version-7 inter-calibration is estimated to be 0.1 K, based on inter-satellite comparisons and validation of the ocean products against in situ measurements. The data record produced by RSS has had a significant scientific impact. Over just the last 14 years (2000-2013) RSS data have been used in 743 peer-reviewed journal articles. This is an average of 4.5 peer-reviewed papers published every month made possible with RSS data. Some of the most important scientific contributions made by RSS data have been to the study of the climate. The AR5 Report "Climate Change 2013: The Physical Science Basis" by the Intergovernmental Panel on Climate Change (IPCC), the internationally accepted authority on climate change, references 20 peer-reviewed journal papers from RSS scientists. The report makes direct use of RSS water vapor data, RSS atmospheric temperatures from MSU/AMSU, and 9 other datasets that are derived from RSS data. The RSS TB data record is

  6. Publication point indicators

    DEFF Research Database (Denmark)

    Elleby, Anita; Ingwersen, Peter

    2010-01-01

    The paper presents comparative analyses of two publication point systems, The Norwegian and the in-house system from the interdiscplinary Danish Institute for International Studies (DIIS), used as case in the study for publications published 2006, and compares central citation-based indicators...... with novel publication point indicators (PPIs) that are formalized and exemplified. Two diachronic citation windows are applied: 2006-07 and 2006-08. Web of Science (WoS) as well as Google Scholar (GS) are applied to observe the cite delay and citedness for the different document types published by DIIS......, journal articles, book chapters/conference papers and monographs. Journal Crown Indicator (JCI) calculations was based on WoS. Three PPIs are proposed: thePublication Point Ratio (PPR), which measures the sum of obtained publiacation points over the sum of the ideal pointws for the same set of documents...

  7. Triple Point Topological Metals

    Directory of Open Access Journals (Sweden)

    Ziming Zhu

    2016-07-01

    Full Text Available Topologically protected fermionic quasiparticles appear in metals, where band degeneracies occur at the Fermi level, dictated by the band structure topology. While in some metals these quasiparticles are direct analogues of elementary fermionic particles of the relativistic quantum field theory, other metals can have symmetries that give rise to quasiparticles, fundamentally different from those known in high-energy physics. Here, we report on a new type of topological quasiparticles—triple point fermions—realized in metals with symmorphic crystal structure, which host crossings of three bands in the vicinity of the Fermi level protected by point group symmetries. We find two topologically different types of triple point fermions, both distinct from any other topological quasiparticles reported to date. We provide examples of existing materials that host triple point fermions of both types and discuss a variety of physical phenomena associated with these quasiparticles, such as the occurrence of topological surface Fermi arcs, transport anomalies, and topological Lifshitz transitions.

  8. Point/Counterpoint

    DEFF Research Database (Denmark)

    Ungar, David; Ernst, Erik

    2007-01-01

    Point Argument: "Dynamic Languages (in Reactive Environments) Unleash Creativity," by David Ungar. For the sake of creativity, the profession needs to concentrate more on inventing new and better dynamic languages and environments and less on improving static languages. Counterpoint Argument...

  9. Iowa Geologic Sampling Points

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Point locations of geologic samples/files in the IGS repository. Types of samples include well cuttings, outcrop samples, cores, drillers logs, measured sections,...

  10. Bedrock Outcrop Points Compilation

    Data.gov (United States)

    Vermont Center for Geographic Information — A compilation of bedrock outcrops as points and/or polygons from 1:62,500 and 1:24,000 geologic mapping by the Vermont Geological Survey, the United States...

  11. Allegheny County Address Points

    Data.gov (United States)

    Allegheny County / City of Pittsburgh / Western PA Regional Data Center — This dataset contains address points which represent physical address locations assigned by the Allegheny County addressing authority. Data is updated by County...

  12. Arctic climate tipping points.

    Science.gov (United States)

    Lenton, Timothy M

    2012-02-01

    There is widespread concern that anthropogenic global warming will trigger Arctic climate tipping points. The Arctic has a long history of natural, abrupt climate changes, which together with current observations and model projections, can help us to identify which parts of the Arctic climate system might pass future tipping points. Here the climate tipping points are defined, noting that not all of them involve bifurcations leading to irreversible change. Past abrupt climate changes in the Arctic are briefly reviewed. Then, the current behaviour of a range of Arctic systems is summarised. Looking ahead, a range of potential tipping phenomena are described. This leads to a revised and expanded list of potential Arctic climate tipping elements, whose likelihood is assessed, in terms of how much warming will be required to tip them. Finally, the available responses are considered, especially the prospects for avoiding Arctic climate tipping points.

  13. National Wetlands Inventory Points

    Data.gov (United States)

    Minnesota Department of Natural Resources — Wetland point features (typically wetlands that are too small to be as area features at the data scale) mapped as part of the National Wetlands Inventory (NWI). The...

  14. ALMA Discovery of Solar Umbral Brightness Enhancement at λ = 3 mm

    Energy Technology Data Exchange (ETDEWEB)

    Iwai, Kazumasa [Institute for Space-Earth Environmental Research, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601 (Japan); Loukitcheva, Maria [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, 323 Martin Luther King Boulevard, Newark, NJ 07102 (United States); Shimojo, Masumi [Chile Observatory, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Solanki, Sami K. [Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, D-37073 Göttingen (Germany); White, Stephen M., E-mail: k.iwai@isee.nagoya-u.ac.jp [Space Vehicles Directorate, Air Force Research Laboratory, Albuquerque, NM (United States)

    2017-06-01

    We report the discovery of a brightness enhancement in the center of a large sunspot umbra at a wavelength of 3 mm using the Atacama Large Millimeter/sub-millimeter Array (ALMA). Sunspots are among the most prominent features on the solar surface, but many of their aspects are surprisingly poorly understood. We analyzed a λ = 3 mm (100 GHz) mosaic image obtained by ALMA that includes a large sunspot within the active region AR12470, on 2015 December 16. The 3 mm map has a 300″ × 300″ field of view and 4.″9 × 2.″2 spatial resolution, which is the highest spatial resolution map of an entire sunspot in this frequency range. We find a gradient of 3 mm brightness from a high value in the outer penumbra to a low value in the inner penumbra/outer umbra. Within the inner umbra, there is a marked increase in 3 mm brightness temperature, which we call an umbral brightness enhancement. This enhanced emission corresponds to a temperature excess of 800 K relative to the surrounding inner penumbral region and coincides with excess brightness in the 1330 and 1400 Å slit-jaw images of the Interface Region Imaging Spectrograph ( IRIS ), adjacent to a partial lightbridge. This λ = 3 mm brightness enhancement may be an intrinsic feature of the sunspot umbra at chromospheric heights, such as a manifestation of umbral flashes, or it could be related to a coronal plume, since the brightness enhancement was coincident with the footpoint of a coronal loop observed at 171 Å.

  15. Developing BrightHearts: a pediatric biofeedback mediated relaxation app to manage procedural pain and anxiety.

    Science.gov (United States)

    Morrow, Angela M; Burton, Karen L O; Watanabe, Melissa M; Cloyd, Benjamin H; Khut, George P

    2017-10-27

    The objective of this study was to develop a child-friendly biofeedback mediated relaxation device called "BrightHearts". Qualitative data were collected at a tertiary pediatric hospital to inform an iterative design process. Clinicians participated in expert group interviews to identify practical considerations which would facilitate the use of BrightHearts during procedures and provide feedback on prototype designs. Children aged 7-18 years participated in interactive exhibitions of the prototypes and were interviewed about their experience using BrightHearts. Twenty-four clinicians participated in 6 group interviews. Thirty-nine children participated in interactive exhibitions and 21 were interviewed. Clinicians placed high value on the following factors in the management of procedural pain: providing children with an element of control, the use of relaxation techniques, the use of portable electronic devices such as iPads (Apple Inc Cupertino CA). They highlighted the need for BrightHearts to be cost effective, portable and capable of engaging childrens' interest. They confirmed the utility of developing a biofeedback assisted relaxation device for children. Based on the factors identified by clinicians BrightHearts was developed as an iPad app paired with a wireless heart rate monitor. The BrightHearts heart rate biofeedback application displays a digital geometric artwork which responds to changes in heart rate. Children aged 7 to 17 years understood the concept of biofeedback and operate the app by slowing their heart rate. The BrightHearts app can be used to teach children biofeedback assisted relaxation. Ongoing studies are evaluating its efficacy for the management of procedural pain in children. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  16. Indexing Moving Points

    DEFF Research Database (Denmark)

    Agarwal, Pankaj K.; Arge, Lars Allan; Erickson, Jeff

    2003-01-01

    We propose three indexing schemes for storing a set S of N points in the plane, each moving along a linear trajectory, so that any query of the following form can be answered quickly: Given a rectangle R and a real value t, report all K points of S that lie inside R at time t. We first present...... an indexing structure that, for any given constant >0, uses O(N/B) disk blocks and answers a query in O((N/B)1/2+ +K/B) I/Os, where B is the block size. It can also report all the points of S that lie inside R during a given time interval. A point can be inserted or deleted, or the trajectory of a point can...... be changed, in O(logB2 N) I/Os. Next, we present a general approach that improves the query time if the queries arrive in chronological order, by allowing the index to evolve over time. We obtain a tradeoff between the query time and the number of times the index needs to be updated as the points move. We...

  17. Georeferenced Point Clouds: A Survey of Features and Point Cloud Management

    Directory of Open Access Journals (Sweden)

    Johannes Otepka

    2013-10-01

    Full Text Available This paper presents a survey of georeferenced point clouds. Concentration is, on the one hand, put on features, which originate in the measurement process themselves, and features derived by processing the point cloud. On the other hand, approaches for the processing of georeferenced point clouds are reviewed. This includes the data structures, but also spatial processing concepts. We suggest a categorization of features into levels that reflect the amount of processing. Point clouds are found across many disciplines, which is reflected in the versatility of the literature suggesting specific features.

  18. Search for high energy neutrinos from bright GRBs with ANTARES

    Directory of Open Access Journals (Sweden)

    Sanguineti M.

    2017-01-01

    Full Text Available Gamma-ray bursts are a possible site of hadronic acceleration, thus neutrinos are expected in correspondence of a GRB event. The brightest GRB observed between 2008 and 2013 (GRB080916C, GRB110918A, GRB130427A and GRB130505A have been investigated using the data of the ANTARES high energy neutrino telescope. In this paper two of most promising models of the GRB neutrino emission will be studied: the internal shock model and the photospheric model. No muons have been measured in space and time correlation with the selected GRBs and upper limits at 90% C.L. on the expected neutrino fluxes have been derived. This measure allows also setting constraints on some parameters used in the modeling of the neutrino flux: the bulk Lorentz factor of the jet Г and the baryon loading fp.

  19. Bright Side of Lignin Depolymerization: Toward New Platform Chemicals

    Science.gov (United States)

    2018-01-01

    Lignin, a major component of lignocellulose, is the largest source of aromatic building blocks on the planet and harbors great potential to serve as starting material for the production of biobased products. Despite the initial challenges associated with the robust and irregular structure of lignin, the valorization of this intriguing aromatic biopolymer has come a long way: recently, many creative strategies emerged that deliver defined products via catalytic or biocatalytic depolymerization in good yields. The purpose of this review is to provide insight into these novel approaches and the potential application of such emerging new structures for the synthesis of biobased polymers or pharmacologically active molecules. Existing strategies for functionalization or defunctionalization of lignin-based compounds are also summarized. Following the whole value chain from raw lignocellulose through depolymerization to application whenever possible, specific lignin-based compounds emerge that could be in the future considered as potential lignin-derived platform chemicals. PMID:29337543

  20. Search for high energy neutrinos from bright GRBs with ANTARES

    Science.gov (United States)

    Celli, S.; Sanguineti, M.; Turpin, D.; ANTARES Collaboration

    2017-09-01

    Gamma-ray bursts are thought to be cosmic-ray accelerators, thus neutrinos are expected from the decay of charged mesons, produced in pγ interactions. The search for high-energy neutrinos from astrophysical sources is one of the main goals of the ANTARES scientific project. The methods and the results of a search for neutrinos from the brightest GRBs observed between 2008 and 2013 are presented. Two scenarios of the fireball model have been investigated: the internal shock and the photospheric case. Since no events have been detected in time and space coincidence with any of these bursts, upper limits at 90% C.L. on the expected neutrino fluxes are derived, as well as constraints on some parameters used in the modeling of the neutrino yield, as the bulk Lorentz factor of the jet and the baryon loading fp .

  1. COMET C/2011 W3 (LOVEJOY): ORBIT DETERMINATION, OUTBURSTS, DISINTEGRATION OF NUCLEUS, DUST-TAIL MORPHOLOGY, AND RELATIONSHIP TO NEW CLUSTER OF BRIGHT SUNGRAZERS

    Energy Technology Data Exchange (ETDEWEB)

    Sekanina, Zdenek; Chodas, Paul W., E-mail: Zdenek.Sekanina@jpl.nasa.gov, E-mail: Paul.W.Chodas@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

    2012-10-01

    We describe the physical and orbital properties of C/2011 W3. After surviving perihelion passage, the comet was observed to undergo major physical changes. The permanent loss of the nuclear condensation and the formation of a narrow spine tail were observed first at Malargue, Argentina, on December 20 and then systematically at Siding Spring, Australia. The process of disintegration culminated with a terminal fragmentation event on December 17.6 UT. The postperihelion dust tail, observed for {approx}3 months, was the product of activity over <2 days. The nucleus' breakup and crumbling were probably caused by thermal stress due to the penetration of the intense heat pulse deep into the nucleus' interior after perihelion. The same mechanism may be responsible for cascading fragmentation of sungrazers at large heliocentric distances. The delayed response to the hostile environment in the solar corona is at odds with the rubble-pile model, since the residual mass of the nucleus, estimated at {approx}10{sup 12} g (equivalent to a sphere 150-200 m across) just before the terminal event, still possessed nontrivial cohesive strength. The high production rates of atomic oxygen, observed shortly after perihelion, are compatible with a subkilometer-sized nucleus. The spine tail-the product of the terminal fragmentation-was a synchronic feature, whose brightest part contained submillimeter-sized dust grains, released at velocities of up to 30 m s{sup -1}. The loss of the nuclear condensation prevented an accurate orbital-period determination by traditional techniques. Since the missing nucleus must have been located on the synchrone, whose orientation and sunward tip have been measured, we compute the astrometric positions of this missing nucleus as the coordinates of the points of intersection of the spine tail's axis with the lines of forced orbital-period variation, derived from the orbital solutions based on high-quality preperihelion astrometry from the

  2. Visibility of noisy point cloud data

    KAUST Repository

    Mehra, Ravish

    2010-06-01

    We present a robust algorithm for estimating visibility from a given viewpoint for a point set containing concavities, non-uniformly spaced samples, and possibly corrupted with noise. Instead of performing an explicit surface reconstruction for the points set, visibility is computed based on a construction involving convex hull in a dual space, an idea inspired by the work of Katz et al. [26]. We derive theoretical bounds on the behavior of the method in the presence of noise and concavities, and use the derivations to develop a robust visibility estimation algorithm. In addition, computing visibility from a set of adaptively placed viewpoints allows us to generate locally consistent partial reconstructions. Using a graph based approximation algorithm we couple such reconstructions to extract globally consistent reconstructions. We test our method on a variety of 2D and 3D point sets of varying complexity and noise content. © 2010 Elsevier Ltd. All rights reserved.

  3. Holographic 4-point correlators with heavy states

    Science.gov (United States)

    Galliani, Andrea; Giusto, Stefano; Russo, Rodolfo

    2017-10-01

    The AdS/CFT duality maps supersymmetric heavy operators with conformal dimension of the order of the central charge to asymptotically AdS supergravity solutions. We show that by studying the quadratic fluctuations around such backgrounds it is possible to derive the 4-point correlators of two light and two heavy states in the supergravity approximation. We provide an explicit example in the AdS3 setup relevant for the duality with the D1-D5 CFT. Contrary to previously studied examples, the supergravity correlator derived in this work differs from the result obtained at the CFT orbifold point. Our method bypasses the difficulties of applying the standard Witten's diagrams approach to correlators with operators of large conformal dimension and also avoids some technical steps that have made the computation of dynamical 4-point correlators in the AdS3/CFT2 context unfeasible until now.

  4. A Randomized Controlled Trial of Cognitive-Behavior Therapy Plus Bright Light Therapy for Adolescent Delayed Sleep Phase Disorder

    Science.gov (United States)

    Gradisar, Michael; Dohnt, Hayley; Gardner, Greg; Paine, Sarah; Starkey, Karina; Menne, Annemarie; Slater, Amy; Wright, Helen; Hudson, Jennifer L.; Weaver, Edward; Trenowden, Sophie

    2011-01-01

    Objective: To evaluate cognitive-behavior therapy plus bright light therapy (CBT plus BLT) for adolescents diagnosed with delayed sleep phase disorder (DSPD). Design: Randomized controlled trial of CBT plus BLT vs. waitlist (WL) control with comparisons at pre- and post-treatment. There was 6-month follow-up for the CBT plus BLT group only. Setting: Flinders University Child & Adolescent Sleep Clinic, Adelaide, South Australia. Patients: 49 adolescents (mean age 14.6 ± 1.0 y, 53% males) diagnosed with DSPD; mean chronicity 4 y 8 months; 16% not attending school. Eighteen percent of adolescents dropped out of the study (CBT plus BLT: N = 23 vs WL: N = 17). Interventions: CBT plus BLT consisted of 6 individual sessions, including morning bright light therapy to advance adolescents' circadian rhythms, and cognitive restructuring and sleep education to target associated insomnia and sleep hygiene. Measurements and Results: DSPD diagnosis was performed via a clinical interview and 7-day sleep diary. Measurements at each time-point included online sleep diaries and scales measuring sleepiness, fatigue, and depression symptoms. Compared to WL, moderate-to-large improvements (d = 0.65-1.24) were found at post-treatment for CBT plus BLT adolescents, including reduced sleep latency, earlier sleep onset and rise times, total sleep time (school nights), wake after sleep onset, sleepiness, and fatigue. At 6-month follow-up (N = 15), small-to-large improvements (d = 0.24-1.53) continued for CBT plus BLT adolescents, with effects found for all measures. Significantly fewer adolescents receiving CBT plus BLT met DPSD criteria at post-treatment (WL = 82% vs. CBT plus BLT = 13%, P sleep and daytime impairments in the immediate and long-term. Studies evaluating the treatment effectiveness of each treatment component are needed. Clinical Trial Information: Australia – New Zealand Trials Registry Number: ACTRN12610001041044. Citation: Gradisar M; Dohnt H; Gardner G; Paine S; Starkey

  5. Tracing the stellar component of low surface brightness Milky Way dwarf galaxies to their outskirts. I. Sextans

    Science.gov (United States)

    Cicuéndez, L.; Battaglia, G.; Irwin, M.; Bermejo-Climent, J. R.; McMonigal, B.; Bate, N. F.; Lewis, G. F.; Conn, A. R.; de Boer, T. J. L.; Gallart, C.; Guglielmo, M.; Ibata, R.; McConnachie, A.; Tolstoy, E.; Fernando, N.

    2018-01-01

    Aims: We present results from deep and very spatially extended CTIO/DECam g and r photometry (reaching out to 2 mag below the oldest main-sequence turn-off and covering 20 deg2) around the Sextans dwarf spheroidal galaxy. We aim to use this dataset to study the structural properties of Sextans overall stellar population and its member stars in different evolutionary phases, as well as to search for possible signs of tidal disturbance from the Milky Way, which would indicate departure from dynamical equilibrium. Methods: We performed the most accurate and quantitative structural analysis to-date of Sextans' stellar components by applying Bayesian Monte Carlo Markov chain methods to the individual stars' positions. Surface density maps are built by statistically decontaminating the sample through a matched filter analysis of the colour-magnitude diagram, and then analysed for departures from axisymmetry. Results: Sextans is found to be significantly less spatially extended and more centrally concentrated than early studies suggested. No statistically significant distortions or signs of tidal disturbances were found down to a surface brightness limit of 31.8 mag/arcsec2 in V-band. We identify an overdensity in the central regions that may correspond to previously reported kinematic substructure(s). In agreement with previous findings, old and metal-poor stars such as Blue Horizontal Branch stars cover a much larger area than stars in other evolutionary phases, and bright Blue Stragglers (BSs) are less spatially extended than faint ones. However, the different spatial distribution of bright and faint BSs appears consistent with the general age and metallicity gradients found in Sextans' stellar component. This is compatible with Sextans BSs having formed by evolution of binaries and not necessarily due to the presence of a central disrupted globular cluster, as suggested in the literature. We provide structural parameters for the various populations analysed and make

  6. Why Bond Critical Points Are Not "Bond" Critical Points.

    Science.gov (United States)

    Shahbazian, Shant

    2017-12-28

    Equating (3,-1) critical points (CPs), derived from the topological analysis of the electron densities, to chemical bonds has triggered a lot of confusion in recent years. Part of this confusion stems from calling these CPs "bond" CPs (BCPs). While the origin of this terminology is traceable to the late seventies and beginning of eighties, when it sounded reasonable, new computational studies conducted on molecular electron densities cast serious doubt on the supposed universal equivalence between the chemical bonds and (3,-1) CPs. Herein, recent computational studies are briefly reviewed to demonstrate why (3,-1) CPs are not indicators of chemical bonds. It is discussed why this confusing terminology needs to be changed and reemphasized that (3,-1) CPs should be called "line" critical points (LCPs). The proposed terminology detaches the topological properties of molecular electron densities from any a priori chemical interpretation. Such detachment, if adopted by other authors, will hopefully prevent further misinterpretation of the data emerging from the quantum theory of atoms in molecules (QTAIM). © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Global Observations of the 630-nm Nightglow and Patterns of Brightness Measured by ISUAL

    Directory of Open Access Journals (Sweden)

    Chih-Yu Chiang

    2013-01-01

    Full Text Available This study investigates the distributions and occurrence mechanisms of the global local-midnight airglow brightness through FORMOSAT-2/ISUAL satellite imaging observations. We focus on the OI 630.0 nm nightglow emission at altitudes of ~250 km along equatorial space. The database used in this study included data from 2007 to 2008 under solar minimum conditions. The data were classified into four specified types in the statistical study. We found that the occurrence of equatorial brightness was often in the vicinity of the geographic equator and mostly at equinoxes with a tendency to move toward the summer hemisphere as the season changes. Conjugate brightness occurring simultaneously on both sides of the geomagnetic equator was observed predominantly in the northern winter. Furthermore, midnight brightness appeared to have lower luminosity from May to July. We suggest that the global midnight brightness associated with the locations and seasons was the result of several effects which include the influence of the thermospheric midnight temperature maximum (MTM, summer-to-winter neutral wind, and ionospheric anomalies.

  8. Blue Laser Imaging-Bright Improves Endoscopic Recognition of Superficial Esophageal Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Akira Tomie

    2016-01-01

    Full Text Available Background/Aims. The aim of this study was to evaluate the endoscopic recognition of esophageal squamous cell carcinoma (ESCC using four different methods (Olympus white light imaging (O-WLI, Fujifilm white light imaging (F-WLI, narrow band imaging (NBI, and blue laser imaging- (BLI- bright. Methods. We retrospectively analyzed 25 superficial ESCCs that had been examined using the four different methods. Subjective evaluation was provided by three endoscopists as a ranking score (RS of each image based on the ease of detection of the cancerous area. For the objective evaluation we calculated the color difference scores (CDS between the cancerous and noncancerous areas with each of the four methods. Results. There was no difference between the mean RS of O-WLI and F-WLI. The mean RS of NBI was significantly higher than that of O-WLI and that of BLI-bright was significantly higher than that of F-WLI. Moreover, the mean RS of BLI-bright was significantly higher than that of NBI. Furthermore, in the objective evaluation, the mean CDS of BLI-bright was significantly higher than that of O-WLI, F-WLI, and NBI. Conclusion. The recognition of superficial ESCC using BLI-bright was more efficacious than the other methods tested both subjectively and objectively.

  9. The alerting effects of caffeine, bright light and face washing after a short daytime nap.

    Science.gov (United States)

    Hayashi, Mitsuo; Masuda, Akiko; Hori, Tadao

    2003-12-01

    The present study examined whether the combination of a short daytime nap with caffeine, bright light and face washing was effective against mid-afternoon sleepiness. Ten young healthy adults participated in 5 experimental conditions; those experiments were-Nap only: taking a 20 min nap; Caffeine+Nap: taking 200 mg of caffeine followed by a nap; Nap+Bright-light: being exposed to 2000 lx of bright light for 1 min immediately after napping; Nap+Face-washing: washing their faces immediately after napping; and No-Nap: taking a rest without sleep. These naps were taken at 12:40 hours. The subjects engaged in computer tasks for 15 min before napping and for 1 h after napping. Caffeine+Nap was the most effective for subjective sleepiness and performance level; its effects lasted throughout 1 h after napping. Nap+Bright-light was comparable with Caffeine+Nap, except for performance level. Nap+Face-washing showed mild and transient effects, however, it suppressed subjective sleepiness immediately after napping. The effects of a short nap against mid-afternoon sleepiness could be enhanced by combining caffeine intake, exposure to bright light, or face washing. The present study would provide effective countermeasures against mid-afternoon sleepiness and sleepiness related accidents.

  10. A randomized controlled trial of cognitive-behavior therapy plus bright light therapy for adolescent delayed sleep phase disorder.

    Science.gov (United States)

    Gradisar, Michael; Dohnt, Hayley; Gardner, Greg; Paine, Sarah; Starkey, Karina; Menne, Annemarie; Slater, Amy; Wright, Helen; Hudson, Jennifer L; Weaver, Edward; Trenowden, Sophie

    2011-12-01

    To evaluate cognitive-behavior therapy plus bright light therapy (CBT plus BLT) for adolescents diagnosed with delayed sleep phase disorder (DSPD). Randomized controlled trial of CBT plus BLT vs. waitlist (WL) control with comparisons at pre- and post-treatment. There was 6-month follow-up for the CBT plus BLT group only. Flinders University Child & Adolescent Sleep Clinic, Adelaide, South Australia. 49 adolescents (mean age 14.6 ± 1.0 y, 53% males) diagnosed with DSPD; mean chronicity 4 y 8 months; 16% not attending school. Eighteen percent of adolescents dropped out of the study (CBT plus BLT: N = 23 vs. WL: N = 17). CBT plus BLT consisted of 6 individual sessions, including morning bright light therapy to advance adolescents' circadian rhythms, and cognitive restructuring and sleep education to target associated insomnia and sleep hygiene. DSPD diagnosis was performed via a clinical interview and 7-day sleep diary. Measurements at each time-point included online sleep diaries and scales measuring sleepiness, fatigue, and depression symptoms. Compared to WL, moderate-to-large improvements (d = 0.65-1.24) were found at post-treatment for CBT plus BLT adolescents, including reduced sleep latency, earlier sleep onset and rise times, total sleep time (school nights), wake after sleep onset, sleepiness, and fatigue. At 6-month follow-up (N = 15), small-to-large improvements (d = 0.24-1.53) continued for CBT plus BLT adolescents, with effects found for all measures. Significantly fewer adolescents receiving CBT plus BLT met DPSD criteria at post-treatment (WL = 82% vs. CBT plus BLT = 13%, P adolescent DSPD is effective for improving multiple sleep and daytime impairments in the immediate and long-term. Studies evaluating the treatment effectiveness of each treatment component are needed. Australia-New Zealand Trials Registry Number: ACTRN12610001041044.

  11. Fluorescent monomers: "bricks" that make a molecularly imprinted polymer "bright".

    Science.gov (United States)

    Wan, Wei; Wagner, Sabine; Rurack, Knut

    2016-03-01

    Molecularly imprinted polymers (MIPs) are potent and established recognition phases in separation and enrichment applications. Because of their robustness, versatility and format adaptability, they also constitute very promising sensing phases, especially when the active sensing element is directly integrated into the MIP. Fluorescent MIPs incorporating fluorescent monomers are perhaps the best developed and most successful approach here. This article reviews the state of the art in this field, discussing the pros and cons of the use of fluorescent dye and probe derivatives as such monomers, the different molecular interaction forces for template complexation, signalling modes and a variety of related approaches that have been realized over the years, including Förster resonance energy transfer processes, covalent imprinting, postmodification attachment of fluorescent units and conjugated polymers as MIPs; other measurement schemes and sensing chemistries that use MIPs and fluorescence interrogation to solve analytical problems (fluorescent competitive assays, fluorescent analytes, etc.) are not covered here. Throughout the article, photophysical processes are discussed to facilitate understanding of the effects that can occur when one is planning for a fluorescence response to happen in a constrained polymer matrix. The article concludes with a concise assessment of the suitability of the different formats for sensor realization.

  12. Cloud point extraction of iron(III) and vanadium(V) using 8-quinolinol derivatives and Triton X-100 and determination of 10(-7)moldm(-3) level iron(III) in riverine water reference by a graphite furnace atomic absorption spectroscopy.

    Science.gov (United States)

    Ohashi, Akira; Ito, Hiromi; Kanai, Chikako; Imura, Hisanori; Ohashi, Kousaburo

    2005-01-30

    The cloud point extraction behavior of iron(III) and vanadium(V) using 8-quinolinol derivatives (HA) such as 8-quinolinol (HQ), 2-methyl-8-quinolinol (HMQ), 5-butyloxymethyl-8-quinolinol (HO(4)Q), 5-hexyloxymethyl-8-quinolinol (HO(6)Q), and 2-methyl-5-octyloxymethyl-8-quinolinol (HMO(8)Q) and Triton X-100 solution was investigated. Iron(III) was extracted with HA and 4% (v/v) Triton X-100 in the pH range of 1.70-5.44. Above pH 4.0, more than 95% of iron(III) was extracted with HQ, HMQ, and HMO(8)Q. Vanadium(V) was also extracted with HA and 4% (v/v) Triton X-100 in the pH range of 2.07-5.00, and the extractability increased in the following order of HMQ extraction was applied to the determination of iron(III) in the riverine water reference by a graphite furnace atomic absorption spectroscopy. When 1.25 x 10(-3)M HMQ and 1% (v/v) Triton X-100 were used, the found values showed a good agreement with the certified ones within the 2% of the R.S.D. Moreover, the effect of an alkyl group on the solubility of 5-alkyloxymethyl-8-quinolinol and 2-methyl-5-alkyloxymethyl-8-quinolinol in 4% (v/v) Triton X-100 at 25 degrees C was also investigated.

  13. When "light" and "dark" thoughts become light and dark responses: affect biases brightness judgments.

    Science.gov (United States)

    Meier, Brian P; Robinson, Michael D; Crawford, L Elizabeth; Ahlvers, Whitney J

    2007-05-01

    Metaphors link positive affect to brightness and negative affect to darkness. Research has shown that such mappings are "alive" at encoding in that word-meaning evaluations are faster when font color matches prevailing metaphors (positive = bright; negative = dark). These results, however, involved reaction times, and there are reasons to think that evaluations would be unlikely to influence perceptual judgments, the current focus. Studies 1-3 establish that perceptual judgments were biased in a brighter direction following positive (vs. negative) evaluations, and Study 4 shows that such biases are automatic. The results significantly extend the metaphor representation perspective. Not only do evaluations activate metaphors, but such metaphoric mappings are sufficient to lead individuals to violate input from visual perception when judging an object's brightness.

  14. Subjective comparison of brightness preservation methods for local backlight dimming displays

    DEFF Research Database (Denmark)

    Korhonen, Jari; Mantel, Claire; Forchhammer, Søren

    2015-01-01

    Local backlight dimming is a popular technology in high quality Liquid Crystal Displays (LCDs). In those displays, the backlight is composed of contributions from several individually adjustable backlight segments, set at different backlight luminance levels in different parts of the screen......, according to the luma of the target image displayed on LCD. Typically, transmittance of the liquid crystal cells (pixels) located in the regions with dimmed backlight is increased in order to preserve their relative brightness with respect to the pixels located in the regions with bright backlight...... ordering to compare the relevant methods on a real-life LCD with a local backlight dimming capability. In general, our results show that locally adapted brightness preservation methods produce more preferred visual outcome than global methods, but dependency on the content is also observed. Based...

  15. Variable multimodal light microscopy with interference contrast and phase contrast; dark or bright field.

    Science.gov (United States)

    Piper, T; Piper, J

    2014-07-01

    Using the optical methods described, specimens can be observed with modified multimodal light microscopes based on interference contrast combined with phase contrast, dark- or bright-field illumination. Thus, the particular visual information associated with interference and phase contrast, dark- and bright-field illumination is joined in real-time composite images appearing in enhanced clarity and purified from typical artefacts, which are apparent in standard phase contrast and dark-field illumination. In particular, haloing and shade-off are absent or significantly reduced as well as marginal blooming and scattering. The background brightness and thus the range of contrast can be continuously modulated and variable transitions can be achieved between interference contrast and complementary illumination techniques. The methods reported should be of general interest for all disciplines using phase and interference contrast microscopy, especially in biology and medicine, and also in material sciences when implemented in vertical illuminators. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

  16. Observation of Dissipative Bright Soliton and Dark Soliton in an All-Normal Dispersion Fiber Laser

    Directory of Open Access Journals (Sweden)

    Chunyang Ma

    2016-01-01

    Full Text Available This paper proposes a novel way for controlling the generation of the dissipative bright soliton and dark soliton operation of lasers. We observe the generation of dissipative bright and dark soliton in an all-normal dispersion fiber laser by employing the nonlinear polarization rotation (NPR technique. Through adjusting the angle of the polarizer and analyzer, the mode-locked and non-mode-locked regions can be obtained in different polarization directions. Numerical simulation shows that, in an appropriate pump power range, the dissipative bright soliton and dark soliton can be generated simultaneously in the mode-locked and non-mode-locked regions, respectively. If the pump power exceeds the top limit of this range, only dissipative soliton will exist, whereas if it is below the lower bound of this range, only dark soliton will exist.

  17. Spontaneous formation of bright solitons in self-localized impurities in Bose-Einstein condensates

    Science.gov (United States)

    Boudjemâa, Abdelâali

    2016-04-01

    We study the formation of bright solitons in the impurity component of Bose-Einstein condensate-impurity mixture by using the time-dependent Hartree-Fock-Bogoliubov theory. While we assume the boson-boson and impurity-boson interactions to be effectively repulsive, their character can be changed spontaneously from repulsive to attractive in the presence of strong anomalous correlations. In such a regime the impurity component becomes a system of effectively attractive atoms leading automatically to the generation of bright solitons. We find that this soliton decays at higher temperatures due to the dissipation induced by the impurity-host and host-host interactions. We show that after a sudden increase of the impurity-boson strength a train of bright solitons is produced and this can be interpreted in terms of the modulational instability of the time-dependent impurity wave function.

  18. The Influence of Brightness on Functional Assessment by mfERG

    DEFF Research Database (Denmark)

    Christiansen, A T; Kiilgaard, J F; Smith, M

    2012-01-01

    To determine the effect of membrane brightness on multifocal electroretinograms (mfERGs), we implanted poly lactic-co-glycolic acid (PLGA) membranes in the subretinal space of 11 porcine eyes. We compared membranes with their native shiny white color with membranes that were stained with a blue dye...... (Brilliant Blue). Histological and electrophysiological evaluation of the overlying retina was carried out 6 weeks after implantation. Histologically, both white and blue membranes degraded in a spongiform manner leaving a disrupted outer retina with no preserved photoreceptor segments. Multifocal ERG...... revealed the white membranes to have a significantly higher P1-amplitude ratio than the blue (P = 0.027), and a correlation between brightness ratio and P1-amplitude ratio was found (r = 0.762). Based on our findings, we conclude that bright subretinal objects can produce normal mfERG amplitude ratios even...

  19. Plasma density transition trapping as a possible high-brightness electron beam source

    Directory of Open Access Journals (Sweden)

    M. C. Thompson

    2004-01-01

    Full Text Available Plasma density transition trapping is a recently proposed self-injection scheme for plasma wakefield accelerators. This technique uses a sharp downward plasma density transition to trap and accelerate background plasma electrons in a plasma wakefield. This paper examines the quality of electron beams captured using this scheme in terms of emittance, energy spread, and brightness. Two-dimensional particle-in-cell simulations show that these parameters can be optimized by manipulating the plasma density profile. We also develop, and support with simulations, a set of scaling laws that predicts how the brightness of transition trapping beams scales with the plasma density of the system. These scaling laws indicate that transition trapping can produce beams with brightness ≥5×10^{14}   A/(mrad^{2}. A proof-of-principle transition trapping experiment is planned for the near future. The proposed experiment is described in detail.

  20. RADIOASTRON OBSERVATIONS OF THE QUASAR 3C273: A CHALLENGE TO THE BRIGHTNESS TEMPERATURE LIMIT

    Energy Technology Data Exchange (ETDEWEB)

    Kovalev, Y. Y.; Kardashev, N. S.; Voitsik, P. A.; Kovalev, Yu. A.; Lisakov, M. M.; Sokolovsky, K. V. [Astro Space Center of Lebedev Physical Institute, Profsoyuznaya 84/32, 117997 Moscow (Russian Federation); Kellermann, K. I. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Lobanov, A. P.; Zensus, J. A.; Anderson, J. M.; Bach, U.; Kraus, A. [Max-Planck-Institute for Radio Astronomy, Auf dem Hügel 69, D-53121 (Germany); Johnson, M. D. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Gurvits, L. I. [Joint Institute for VLBI ERIC, P.O. Box 2, 7990 AA Dwingeloo (Netherlands); Jauncey, D. L. [CSIRO Astronomy and Space Sciences, Epping, NSW 1710 (Australia); Ghigo, F. [National Radio Astronomy Observatory, Rt. 28/92, Green Bank, WV 24944-0002 (United States); Ghosh, T.; Salter, C. J. [Arecibo Observatory, NAIC, HC3 Box 53995, Arecibo, Puerto Rico, PR 00612 (United States); Petrov, L. Yu. [Astrogeo Center, 7312 Sportsman Drive, Falls Church, VA 22043 (United States); Romney, J. D. [National Radio Astronomy Observatory, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801-0387 (United States)

    2016-03-20

    Inverse Compton cooling limits the brightness temperature of the radiating plasma to a maximum of 10{sup 11.5} K. Relativistic boosting can increase its observed value, but apparent brightness temperatures much in excess of 10{sup 13} K are inaccessible using ground-based very long baseline interferometry (VLBI) at any wavelength. We present observations of the quasar 3C 273, made with the space VLBI mission RadioAstron on baselines up to 171,000 km, which directly reveal the presence of angular structure as small as 26 μas (2.7 light months) and brightness temperature in excess of 10{sup 13} K. These measurements challenge our understanding of the non-thermal continuum emission in the vicinity of supermassive black holes and require a much higher Doppler factor than what is determined from jet apparent kinematics.