WorldWideScience

Sample records for opacity

  1. Opacity

    CERN Document Server

    Huebner, Walter F

    2014-01-01

    The interaction of radiation with matter is a fundamental process in the universe; in particular, the absorption and scattering of radiation by matter (the opacity) govern the formation, evolution, and structure of stars and planets.  But opacity is also important in many terrestrial applications in which radiation is the dominant means of energy transfer, such as controlled nuclear-fusion, laser ablation, atmospheric entry and reentry, and the "greenhouse" effect.  This book covers all aspects of opacity and equations of state for plasmas, gases, vapors, and dust and emphasizes the continuous transformation of phases and molecular compositions with changing density and temperature under conditions of local thermodynamic equilibrium (LTE) while preserving the basic abundances of the chemical elements in a mixture.

  2. Stellar Opacity

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, F J; Iglesias, C A

    1999-11-07

    The monochromatic opacity, {kappa}{sub v}, quantifies the property of a material to remove energy of frequency v from a radiation field. A harmonic average of {kappa}{sub v}, known as the Rosseland mean, {kappa}{sub R}, is frequently used to simplify the calculation of energy transport in stars. The term ''opacity'' is commonly understood to refer to {kappa}{sub R}. Opacity plays an important role in stellar modeling because for most stars radiation is the primary mechanism for transporting energy from the nuclear burning region in the core to the surface. Depending on the mass, convection and electron thermal conduction can also be important modes of stellar energy transport. The efficiency of energy transport is related to the temperature gradient, which is directly proportional to the mean radiative opacity in radiation dominated regions. When the radiative opacity is large, convection can become the more efficient energy transport mechanism. Electron conductive opacity, the resistance of matter to thermal conduction, is inversely proportional to electron thermal conductivity. Thermal conduction becomes the dominant mode of energy transport at high density and low temperature.

  3. Universe opacity and EBL

    CERN Document Server

    Vavrycuk, Vaclav

    2016-01-01

    The observed extragalactic background light (EBL) is affected by light attenuation due to absorption of light by galactic and intergalactic dust in the Universe. Even galactic opacity of 10-20 percent and minute universe intergalactic opacity of $0.01\\,\\mathrm{mag}\\,h\\,\\mathrm{Gpc}^{-1}$ at the local Universe have a significant impact on the EBL because obscuration of galaxies and density of intergalactic dust increase with redshift as $\\left(1+z\\right)^3$. Consequently, intergalactic opacity increases and the Universe becomes considerably opaque at $z > 3$. Adopting realistic values for galactic and intergalactic opacity, the estimates of the EBL for the expanding dusty universe are close to observations. The luminosity density evolution fits well measurements. The model reproduces a steep increase of the luminosity density at $z3.5$.

  4. Universe opacity and EBL

    Science.gov (United States)

    Vavryčuk, Václav

    2017-02-01

    The observed extragalactic background light (EBL) is affected by light attenuation due to absorption of light by galactic and intergalactic dust in the Universe. Even galactic opacity of 10-20 per cent and minute universe intergalactic opacity of 0.01 mag h Gpc-1 at the local Universe have a significant impact on the EBL because obscuration of galaxies and density of intergalactic dust increase with redshift as (1 + z)3. Consequently, intergalactic opacity increases and the Universe becomes considerably opaque at z > 3. Adopting realistic values for galactic and intergalactic opacity, the estimates of the EBL for the expanding dusty universe are close to observations. The luminosity density evolution fits well measurements. The model reproduces a steep increase of the luminosity density at z EBL ranges from 100 to 200 nW m-2 sr-1 and is within the limits of 40 and 200 nW m-2 sr-1 of current EBL observations. The model predicts 98 per cent of the EBL coming from radiation of galaxies at z 3.5.

  5. Overapplication opacity in phonological acquisition

    Directory of Open Access Journals (Sweden)

    Olga Urek

    2013-02-01

    Full Text Available Normal 0 false false false EN-US JA X-NONE Phonological opacity is a challenge for parallel OT, which does not allow for intermediate levels of representation. Several modifications of the theory have been proposed over the years to incorporate opacity, all of them falling short of accounting for spontaneous opacity effects in developing grammars. In this paper I demonstrate that if certain independently motivated adjustments are made to the recent OT-based theory of opacity called Optimality Theory with Candidate Chains (OT-CC, see McCarthy 2007, it can successfully deal with spontaneous opacity effects.

  6. Molecular opacities for exoplanets.

    Science.gov (United States)

    Bernath, Peter F

    2014-04-28

    Spectroscopic observations of exoplanets are now possible by transit methods and direct emission. Spectroscopic requirements for exoplanets are reviewed based on existing measurements and model predictions for hot Jupiters and super-Earths. Molecular opacities needed to simulate astronomical observations can be obtained from laboratory measurements, ab initio calculations or a combination of the two approaches. This discussion article focuses mainly on laboratory measurements of hot molecules as needed for exoplanet spectroscopy.

  7. Enhancing OPAC Records for Discovery

    Directory of Open Access Journals (Sweden)

    Patrick Griffis

    2009-09-01

    Full Text Available This article proposes adding keywords and descriptors to the catalog records of electronic databases and media items to enhance their discovery. The authors contend that subject liaisons can add value to OPAC records and enhance discovery of electronic databases and media items by providing searchable keywords and resource descriptions. The authors provide an examination of OPAC records at their own library, which illustrates the disparity of useful keywords and descriptions within the notes field for media item records versus electronic database records. The authors outline methods for identifying useful keywords for indexing OPAC records of electronic databases. Also included is an analysis of the advantages of using Encore’s Community Tag and Community Review features to allow subject liaisons to work directly in the catalog instead of collaborating with cataloging staff

  8. Iron opacity experiments for the solar interior

    Science.gov (United States)

    Nagayama, T.; Bailey, J. E.; Loisel, G.; Rochau, G. A.; Hansen, S. B.; Blancard, C.; Cosse, Ph.; Faussurier, G.; Gilleron, F.; Pain, J.-C.; Pradhan, A. K.; Orban, C.; Pinsonneault, M.; Nahar, S. N.; Iglesias, C. A.; Wilson, B.; Colgan, J.; Fontes, C.; Kilcrease, D.; Sherrill, M.; Macfarlane, J. J.; Golovkin, I.; Mancini, R. C.

    2014-10-01

    Iron opacity experiments near solar interior conditions are performed at SNL Z-machine to better constrain solar models. The SNL opacity science platform satisfies the many challenging requirements for opacity measurements and successfully determines iron opacities at multiple conditions. We found that the agreement between the modeled opacity and the measured opacity deteriorates as Te and ne are raised to approach solar interior conditions. While the inaccuracy of the modeled opacity partially resolves the solar abundance problem, the announcement of such discrepancies has a high impact on the astrophysics, atomic physics, and high energy density physics, and thus more scrutiny on the potential experimental flaws is critical. We report the synthetic investigation for potential sources of systematic uncertainties in the experiments. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000.

  9. Line Broadening and the Solar Opacity Problem

    Science.gov (United States)

    Krief, M.; Feigel, A.; Gazit, D.

    2016-06-01

    The calculation of line widths constitutes theoretical and computational challenges in the calculation of opacities of hot, dense plasmas. Opacity models use line broadening approximations that are untested at stellar interior conditions. Moreover, calculations of atomic spectra of the Sun indicate a large discrepancy in the K-shell line widths between several atomic codes and the Opacity-Project (OP). In this work, the atomic code STAR is used to study the sensitivity of solar opacities to line broadening. Variations in the solar opacity profile due to an increase of the Stark widths resulting from discrepancies with OP, are compared, in light of the solar opacity problem, with the required opacity variations of the present day Sun, as imposed by helioseismic and neutrino observations. The resulting variation profile is much larger than the discrepancy between different atomic codes, agrees qualitatively with the missing opacity profile, recovers about half of the missing opacity nearby the convection boundary, and has a little effect in the internal regions. Since it is hard to estimate quantitatively the uncertainty in the Stark widths, we show that an increase of all line widths by a factor of about ˜100 recovers quantitatively the missing opacity. These results emphasize the possibility that photoexcitation processes are not modeled properly, and more specifically, highlight the need for a better theoretical characterization of the line broadening phenomena at stellar interior conditions, and of the uncertainty due to the way it is implemented by atomic codes.

  10. Analytical opacity formulas for low Z plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Rubiano, J; Rodriguez, R; Gil, J M; Florido, R; Martel, P; Mendoza, M A; Suarez, D [Departamento de FIasica, Universidad de Las Palmas de GC, 35017 Las Palmas de GC (Spain); Minguez, E [Instituto de Fusion Nuclear DENIM. Universidad Politecnica de Madrid, 28019 Madrid (Spain)], E-mail: jgarcia@dfis.ulpgc.es

    2008-05-01

    The accurate computation of radiative opacities is basic in the ICF target physics analysis, in which the radiation is an important feature to determine in detail. For this reason, accurate analytical formulas for giving mean opacities versus temperature and density of the plasma seem to be a useful tool. In this work we analyse some analytical expressions found in the literature for the opacity low Z plasmas in a wide range of temperature and densities. The validity of these formulas for computing the opacity under NLTE conditions is investigated using the new code ABAKO.

  11. The GUI OPAC: Approach with Caution.

    Science.gov (United States)

    Hildreth, Charles R.

    1995-01-01

    Discusses the graphical user interface (GUI) online public access catalog (OPAC), a user interface that uses images to represent options. Topics include user interface design for information retrieval; designing effective bibliographic displays, including subject headings; two design principles; and what GUIs can bring to OPACs. (LRW)

  12. Line broadening and the solar opacity problem

    CERN Document Server

    Krief, M; Gazit, D

    2016-01-01

    The calculation of line widths constitutes a theoretical as well as a computational challenge in the calculation of opacities of hot dense plasmas. Opacity models use line broadening approximations that are untested at stellar interior conditions. Moreover, calculations of atomic spectra nearby the convection zone boundary (CZB) of the sun, indicate a large discrepancy in the K-shell line widths between several atomic codes and the Opacity-Project. In this work, the atomic code STAR is used to study the sensitivity of solar opacities to line-broadening. Atomic spectra of several elements are analyzed and compared within the solar interior. Variations in the solar opacity profile due to changes in the Stark widths are shown to be significant and to result mainly due to K-shell lines. In light of the solar opacity problem, the results are compared with the required opacity variations of the present day sun, as imposed by helioseismic and neutrino observations. It is shown that an increase of the line widths res...

  13. Restricted fish feeding reduces cod otolith opacity

    DEFF Research Database (Denmark)

    Høie, H.; Folkvord, A.; Mosegaard, Henrik

    2008-01-01

    The purpose of this work was to examine the effect of reduced feeding and constant temperature on cod otolith opacity. Three groups of juvenile cod were given restricted food rations at different times for 4 months, resulting in depressed somatic growth. Otolith opacity was measured on pictures...... in otolith opacity were found between individual fish both within groups and between groups. In two of the three groups significantly more translucent otolith material was deposited in response to reduced feeding. Our results show that variations in feeding and hence fish growth resulted in variation...

  14. Summary of Fe opacity measurement platform

    Energy Technology Data Exchange (ETDEWEB)

    Nagayama, Taisuke

    2016-05-01

    This powerpoint presentation goes over the Fe opacity measurement platform, including how the experiment works, what can be gathered from the measurements, what can be gathered from the simulations, and the limitations of the experiment.

  15. The neutrino opacity of neutron rich matter

    Energy Technology Data Exchange (ETDEWEB)

    Alcain, P.N., E-mail: pabloalcain@gmail.com [Departamento de Física, FCEyN, UBA and IFIBA, Conicet, Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires (Argentina); IFIBA-CONICET (Argentina); Dorso, C.O. [Departamento de Física, FCEyN, UBA and IFIBA, Conicet, Pabellón 1, Ciudad Universitaria, 1428 Buenos Aires (Argentina); IFIBA-CONICET (Argentina)

    2017-05-15

    The study of neutron rich matter, present in neutron star, proto-neutron stars and core-collapse supernovae, can lead to further understanding of the behavior of nuclear matter in highly asymmetric nuclei. Heterogeneous structures are expected to exist in these systems, often referred to as nuclear pasta. We have carried out a systematic study of neutrino opacity for different thermodynamic conditions in order to assess the impact that the structure has on it. We studied the dynamics of the neutrino opacity of the heterogeneous matter at different thermodynamic conditions with semiclassical molecular dynamics model already used to study nuclear multifragmentation. For different densities, proton fractions and temperature, we calculate the very long range opacity and the cluster distribution. The neutrino opacity is of crucial importance for the evolution of the core-collapse supernovae and the neutrino scattering.

  16. New Generation of Los Alamos Opacity Tables

    Science.gov (United States)

    Colgan, James; Kilcrease, D. P.; Magee, N. H.; Sherrill, M. E.; Abdallah, J.; Hakel, P.; Fontes, C. J.; Guzik, J. A.; Mussack, K. A.

    2016-05-01

    We present a new generation of Los Alamos OPLIB opacity tables that have been computed using the ATOMIC code. Our tables have been calculated for all 30 elements from hydrogen through zinc and are publicly available through our website. In this poster we discuss the details of the calculations that underpin the new opacity tables. We also show several recent applications of the use of our opacity tables to solar modeling and other astrophysical applications. In particular, we demonstrate that use of the new opacities improves the agreement between solar models and helioseismology, but does not fully resolve the long-standing `solar abundance' problem. The Los Alamos National Laboratory is operated by Los Alamos National Security, LLC for the National Nuclear Security Administration of the U.S. Department of Energy under Contract No. DE-AC5206NA25396.

  17. Opacity Issues in Games with Imperfect Information

    Directory of Open Access Journals (Sweden)

    Bastien Maubert

    2011-06-01

    Full Text Available We study in depth the class of games with opacity condition, which are two-player games with imperfect information in which one of the players only has imperfect information, and where the winning condition relies on the information he has along the play. Those games are relevant for security aspects of computing systems: a play is opaque whenever the player who has imperfect information never "knows" for sure that the current position is one of the distinguished "secret" positions. We study the problems of deciding the existence of a winning strategy for each player, and we call them the opacity-violate problem and the opacity-guarantee problem. Focusing on the player with perfect information is new in the field of games with imperfect-information because when considering classical winning conditions it amounts to solving the underlying perfect-information game. We establish the EXPTIME-completeness of both above-mentioned problems, showing that our winning condition brings a gap of complexity for the player with perfect information, and we exhibit the relevant opacity-verify problem, which noticeably generalizes approaches considered in the literature for opacity analysis in discrete-event systems. In the case of blindfold games, this problem relates to the two initial ones, yielding the determinacy of blindfold games with opacity condition and the PSPACE-completeness of the three problems.

  18. Observational Constraints on Submillimeter Dust Opacity

    CERN Document Server

    Shirley, Yancy L; Pontoppidan, Klaus M; Wilner, David J; Stutz, Amelia M; Bieging, John H; Evans, Neal J

    2010-01-01

    Infrared extinction maps and submillimeter dust continuum maps are powerful probes of the density structure in the envelope of star-forming cores. We make a direct comparison between infrared and submillimeter dust continuum observations of the low-mass Class 0 core, B335, to constrain the ratio of submillimeter to infrared opacity (\\kaprat) and the submillimeter opacity power-law index ($\\kappa \\propto \\lambda^{-\\beta}$). Using the average value of theoretical dust opacity models at 2.2 \\micron, we constrain the dust opacity at 850 and 450 \\micron . Using new dust continuum models based upon the broken power-law density structure derived from interferometric observations of B335 and the infall model derived from molecular line observations of B335, we find that the opacity ratios are $\\frac{\\kappa_{850}}{\\kappa_{2.2}} = (3.21 - 4.80)^{+0.44}_{-0.30} \\times 10^{-4}$ and $\\frac{\\kappa_{450}}{\\kappa_{2.2}} = (12.8 - 24.8)^{+2.4}_{-1.3} \\times 10^{-4}$ with a submillimeter opacity power-law index of $\\beta_{smm}...

  19. Radiation Transport for Explosive Outflows: Opacity Regrouping

    CERN Document Server

    Wollaeger, Ryan T

    2014-01-01

    Implicit Monte Carlo (IMC) and Discrete Diffusion Monte Carlo (DDMC) are methods used to stochastically solve the radiative transport and diffusion equations, respectively. These methods combine into a hybrid transport-diffusion method we refer to as IMC-DDMC. We explore a multigroup IMC-DDMC scheme that, in DDMC, combines frequency groups with sufficient optical thickness. We term this procedure "opacity regrouping". Opacity regrouping has previously been applied to IMC-DDMC calculations for problems in which the dependence of the opacity on frequency is monotonic. We generalize opacity regrouping to non-contiguous groups and implement this in \\supernu, a code designed to do radiation transport in high-velocity outflows with non-monotonic opacities. We find that regrouping of non-contiguous opacity groups generally improves the speed of IMC-DDMC radiation transport. We present an asymptotic analysis that informs the nature of the Doppler shift in DDMC groups and summarize the derivation of the Gentile-Fleck ...

  20. Analytical opacity formulas for ICF elements

    Energy Technology Data Exchange (ETDEWEB)

    Minguez, E. E-mail: minguez@denim.upm.es; Martel, P.; Gil, J.M.; Rubiano, J.G.; Rodriguez, R

    2002-01-01

    Local Thermodynamic Equilibrium (LTE) opacity codes have been developed by the Instituto de Fusion Nuclear (DENIM) during the last years. JIMENA code (Laser and Particle Beams 6 (1998) 265; Laser and Particle Beams 10 (1992) 651) is an opacity code that solves self-consistently, for each temperature and density, the radial Dirac equation with a local spherically symmetrical potential. Very recently we have developed a new opacity code, called ANALOP, that uses an analytical potential (JQSRT 54 (1995) 621), which can include density and temperature effects for atomic data calculations. Opacities are determined with these two codes for selected elements at different plasma conditions. This work is focused on the determination of Rosseland and Planck mean analytical formulas for several single elements used in ICF targets. A scaling law of these mean opacities is given as a function of the plasma parameters: electron temperature and plasma density. These opacities have been tested with numerical results from other codes and with available experimental results.

  1. RADIATION TRANSPORT FOR EXPLOSIVE OUTFLOWS: OPACITY REGROUPING

    Energy Technology Data Exchange (ETDEWEB)

    Wollaeger, Ryan T. [Department of Nuclear Engineering and Engineering Physics, University of Wisconsin, Madison 1500 Engineering Drive, 410 ERB, Madison, WI 53706 (United States); Van Rossum, Daniel R., E-mail: wollaeger@wisc.edu, E-mail: daan@flash.uchicago.edu [Flash Center for Computational Science, Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States)

    2014-10-01

    Implicit Monte Carlo (IMC) and Discrete Diffusion Monte Carlo (DDMC) are methods used to stochastically solve the radiative transport and diffusion equations, respectively. These methods combine into a hybrid transport-diffusion method we refer to as IMC-DDMC. We explore a multigroup IMC-DDMC scheme that in DDMC, combines frequency groups with sufficient optical thickness. We term this procedure ''opacity regrouping''. Opacity regrouping has previously been applied to IMC-DDMC calculations for problems in which the dependence of the opacity on frequency is monotonic. We generalize opacity regrouping to non-contiguous groups and implement this in SuperNu, a code designed to do radiation transport in high-velocity outflows with non-monotonic opacities. We find that regrouping of non-contiguous opacity groups generally improves the speed of IMC-DDMC radiation transport. We present an asymptotic analysis that informs the nature of the Doppler shift in DDMC groups and summarize the derivation of the Gentile-Fleck factor for modified IMC-DDMC. We test SuperNu using numerical experiments including a quasi-manufactured analytic solution, a simple 10 group problem, and the W7 problem for Type Ia supernovae. We find that opacity regrouping is necessary to make our IMC-DDMC implementation feasible for the W7 problem and possibly Type Ia supernova simulations in general. We compare the bolometric light curves and spectra produced by the SuperNu and PHOENIX radiation transport codes for the W7 problem. The overall shape of the bolometric light curves are in good agreement, as are the spectra and their evolution with time. However, for the numerical specifications we considered, we find that the peak luminosity of the light curve calculated using SuperNu is ∼10% less than that calculated using PHOENIX.

  2. The opacity of spiral galaxy disks V. Dust opacity, HI distributions and sub-mm emission

    NARCIS (Netherlands)

    Holwerda, BW; Gonzalez, RA; Allen, RJ; van der Kruit, PC

    2005-01-01

    The opacity of spiral galaxy disks, from counts of distant galaxies, is compared to HI column densities. The opacity measurements are calibrated using the "Synthetic Field Method" from Gonzalez et al. (1998, ApJ, 506, 152), Holwerda et al. (2005a, AJ, 129, 1381). When compared for individual disks,

  3. OPserver: opacities and radiative accelerations on demand

    Science.gov (United States)

    Mendoza, C.; González, J.; Seaton, M. J.; Buerger, P.; Bellorín, A.; Meléndez, M.; Rodríguez, L. S.; Delahaye, F.; Zeippen, C. J.; Palacios, E.; Pradhan, A. K.

    2009-05-01

    We report on developments carried out within the Opacity Project (OP) to upgrade atomic database services to comply with e-infrastructure requirements. We give a detailed description of an interactive, online server for astrophysical opacities, referred to as OPserver, to be used in sophisticated stellar modelling where Rosseland mean opacities and radiative accelerations are computed at every depth point and each evolution cycle. This is crucial, for instance, in chemically peculiar stars and in the exploitation of the new asteroseismological data. OPserver, downloadable with the new OPCD_3.0 release from the Centre de Données Astronomiques de Strasbourg, France, computes mean opacities and radiative data for arbitrary chemical mixtures from the OP monochromatic opacities. It is essentially a client-server network restructuring and optimization of the suite of codes included in the earlier OPCD_2.0 release. The server can be installed locally or, alternatively, accessed remotely from the Ohio Supercomputer Center, Columbus, Ohio, USA. The client is an interactive web page or a subroutine library that can be linked to the user code. The suitability of this scheme in grid computing environments is emphasized, and its extension to other atomic database services for astrophysical purposes is discussed.

  4. Design of the opacity spectrometer for opacity measurements at the National Ignition Facility

    Science.gov (United States)

    Ross, P. W.; Heeter, R. F.; Ahmed, M. F.; Dodd, E.; Huffman, E. J.; Liedahl, D. A.; King, J. A.; Opachich, Y. P.; Schneider, M. B.; Perry, T. S.

    2016-11-01

    Recent experiments at the Sandia National Laboratory Z facility have called into question models used in calculating opacity, of importance for modeling stellar interiors. An effort is being made to reproduce these results at the National Ignition Facility (NIF). These experiments require a new X-ray opacity spectrometer (OpSpec) spanning 540 eV-2100 eV with a resolving power E/ΔE > 700. The design of the OpSpec is presented. Photometric calculations based on expected opacity data are also presented. First use on NIF is expected in September 2016.

  5. Detailed opacity calculations for stellar models

    Science.gov (United States)

    Pain, Jean-Christophe; Gilleron, Franck

    2016-10-01

    We present a state of the art of precise spectral opacity calculations illustrated by stellar applications. The essential role of laboratory experiments to check the quality of the computed data is underlined. We review some X-ray and XUV laser and Z-pinch photo-absorption measurements as well as X-ray emission spectroscopy experiments of hot dense plasmas produced by ultra-high-intensity laser interaction. The measured spectra are systematically compared with the fine-structure opacity code SCO-RCG. Focus is put on iron, due to its crucial role in the understanding of asteroseismic observations of Beta Cephei-type and Slowly Pulsating B stars, as well as in the Sun. For instance, in Beta Cephei-type stars (which should not be confused with Cepheid variables), the iron-group opacity peak excites acoustic modes through the kappa-mechanism. A particular attention is paid to the higher-than-predicted iron opacity measured on Sandia's Z facility at solar interior conditions (boundary of the convective zone). We discuss some theoretical aspects such as orbital relaxation, electron collisional broadening, ionic Stark effect, oscillator-strength sum rules, photo-ionization, or the ``filling-the-gap'' effect of highly excited states.

  6. Solar opacity calculations using the super-transition-array method

    CERN Document Server

    Krief, M; Gazit, D

    2016-01-01

    An opacity model based on the Super-Transition-Array (STA) method for the calculation of monochromatic opacities of local thermodynamic equilibrium plasmas was developed. The model is described and used to calculate spectral opacities for a solar model implementing the recent AGSS09 composition. Calculations are carried throughout the solar radiative zone. The relative contributions of different chemical elements and photon-matter processes to the total Rosseland mean opacity are analyzed in detail. Monochromatic opacities and charge state distributions were compared with the widely used Opacity-Project (OP) code, for several elements near the radiation-convection interface. STA Rosseland opacities for the solar mixture show a very good agreement with OP and the OPAL opacity code, throughout the radiation zone. Finally, an explicit STA calculation of the full AGSS09 photospheric mixture, including all heavy metals was performed. It was shown that due to their extremely low abundance, and despite being very go...

  7. Opacity of Shock-Generated Argon Plasmas

    Institute of Scientific and Technical Information of China (English)

    王藩侯; 陈敬平; 周显明; 李西军; 经福谦; 孟续军; 孙永盛

    2001-01-01

    Argon plasmas with uniform density and temperature are generated by a planar shock wave through argon gas. The opacities of argon plasma, covering the thermodynamic states at temperatures of 1.4-2.2eV and in densities of 0.0083- 0.015 g/cm3, are investigated by measuring the emitted radiance versus time at several visible wavelengths. Comparison of the measured opacities with those calculated demonstrates that the average atom model can be used well to describe the essential transport behaviour of photons in argon plasma under the abovementioned thermodynamic condition. A simplified and self-consistent method to deduce the reflectivity R(λ) at the baseplate surface is applied. It demonstrates that the values of R(λ) are all around 0.4 in the experiments, which are basically in agreement with those given by Erskine previously (1994 J. Quant. Spectrosc. Radiat.Transfer 51 97).

  8. Revitalizing the Library OPAC: Interface, Searching, and Display Challenges

    Directory of Open Access Journals (Sweden)

    Jia Mi

    2008-03-01

    Full Text Available The behavior of academic library users has drastically changed in recent years. Internet search engines have become the preferred tool over the library online public access catalog (OPAC for finding information. Libraries are losing ground to online search engines. In this paper, two aspects of OPAC use are studied: (1 the current OPAC interface and searching capabilities, and (2 the OPAC bibliographic display. The purpose of the study is to find answers to the following questions: Why is the current OPAC ineffective? What can libraries and librarians do to deliver an OPAC that is as good as search engines to better serve our users? Revitalizing the library OPAC is one of the pressing issues that has to be accomplished.

  9. Extended Opacity Tables with Higher Temperature-Density-Frequency Resolution

    Science.gov (United States)

    Schillaci, Mark; Orban, Chris; Delahaye, Franck; Pinsonneault, Marc; Nahar, Sultana; Pradhan, Anil

    2015-05-01

    Theoretical models for plasma opacities underpin our understanding of radiation transport in many different astrophysical objects. These opacity models are also relevant to HEDP experiments such as ignition scale experiments on NIF. We present a significantly expanded set of opacity data from the widely utilized Opacity Project, and make these higher resolution data publicly available through OSU's portal with dropbox.com. This expanded data set is used to assess how accurate the interpolation of opacity data in temperature-density-frequency dimensions must be in order to adequately model the properties of most stellar types. These efforts are the beginning of a larger project to improve the theoretical opacity models in light of experimental results at the Sandia Z-pinch showing that the measured opacity of Iron disagrees strongly with all current models.

  10. Hohlraum calculations for the NIF opacity platform

    Science.gov (United States)

    Dodd, E. S.; Perry, T. S.; Tregillis, I. L.; Kline, J. L.; Heeter, R. F.; Liedahl, D. A.; Opachich, Y. P.

    2015-11-01

    A summary of initial hohlraum calculations for planned opacity experiments at the National Ignition Facility (NIF) will be given. The purpose of these experiments is to make LTE opacity measurements of iron at the same conditions as previous experiments on Sandia's Z facility: 156 eV and 190 eV. Ongoing discrepancies between opacity data and theory make corroborating data highly important. The target considered in these calculations is a standard cylindrical hohlraum, with diameter 5.75 mm, but baffles have been placed between the laser hot spot and the sample to maintain the iron in LTE. The hohlraum is driven with a 3 ns flat top laser pulse, but limited to 500 kJ and only the outer beams. The inner beams will be used to drive a capsule implosion, which backlights the iron for the absorption measurements. The iron itself is a thin disk, mixed with magnesium as a spectroscopic tracer, and tamped with beryllium to minimize expansion. A description of the experimental set-up will be given. Supported under the US DOE by the Los Alamos National Security, LLC under contract DE-AC52-06NA25396.

  11. Galactic cold cores. V. Dust opacity

    Science.gov (United States)

    Juvela, M.; Ristorcelli, I.; Marshall, D. J.; Montillaud, J.; Pelkonen, V.-M.; Ysard, N.; McGehee, P.; Paladini, R.; Pagani, L.; Malinen, J.; Rivera-Ingraham, A.; Lefèvre, C.; Tóth, L. V.; Montier, L. A.; Bernard, J.-P.; Martin, P.

    2015-12-01

    Context. The project Galactic Cold Cores has carried out Herschel photometric observations of interstellar clouds where the Planck satellite survey has located cold and compact clumps. The sources represent different stages of cloud evolution from starless clumps to protostellar cores and are located in different Galactic environments. Aims: We examine this sample of 116 Herschel fields to estimate the submillimetre dust opacity and to search for variations that might be attributed to the evolutionary stage of the sources or to environmental factors, including the location within the Galaxy. Methods: The submillimetre dust opacity was derived from Herschel data, and near-infrared observations of the reddening of background stars are converted into near-infrared optical depth. We investigated the systematic errors affecting these parameters and used modelling to correct for the expected biases. The ratio of 250 μm and J band opacities is correlated with the Galactic location and the star formation activity. We searched for local variations in the ratio τ(250 μm)/τ(J) using the correlation plots and opacity ratio maps. Results: We find a median ratio of τ(250 μm) /τ(J) = (1.6 ± 0.2) × 10-3, which is more than three times the mean value reported for the diffuse medium. Assuming an opacity spectral index β = 1.8 instead of β = 2.0, the value would be lower by ~ 30%. No significant systematic variation is detected with Galactocentric distance or with Galactic height. Examination of the τ(250 μm) /τ(J) maps reveals six fields with clear indications of a local increase of submillimetre opacity of up to τ(250 μm) /τ(J) ~ 4 × 10-3 towards the densest clumps. These are all nearby fields with spatially resolved clumps of high column density. Conclusions: We interpret the increase in the far-infrared opacity as a sign of grain growth in the densest and coldest regions of interstellar clouds. Planck (http://www.esa.int/Planck) is a project of the European

  12. Mean gas opacity for circumstellar environments and equilibrium temperature degeneracy

    CERN Document Server

    Malygin, M G; Klahr, H; Dullemond, C P; Henning, Th

    2014-01-01

    In a molecular cloud dust opacity typically dominates over gas opacity, yet in the vicinities of forming stars dust is depleted, and gas is the sole provider of opacity. In the optically thin circumstellar environments the radiation temperature cannot be assumed to be equal to the gas temperature, hence the two-temperature Planck means are necessary to calculate the radiative equilibrium. By using the two-temperature mean opacity one does obtain the proper equilibrium gas temperature in a circumstellar environment, which is in a chemical equilibrium. A careful consideration of a radiative transfer problem reveals that the equilibrium temperature solution can be degenerate in an optically thin gaseous environment. We compute mean gas opacities based on the publicly available code DFSYNTHE by Kurucz and Castelli. We performed the calculations assuming local thermodynamic equilibrium and an ideal gas equation of state. The values were derived by direct integration of the high-resolution opacity spectrum. We prod...

  13. IPOPv2 online service for the generation of opacity tables

    Science.gov (United States)

    Delahaye, Franck; Zwölf, Carlo Maria; Zeippen, Claude J.; Mendoza, Claudio

    2016-03-01

    In the framework of the present phase - IPOPv2 - of the international Opacity Project (OP), a new web service has been implemented based on the latest release of the OP opacities. The user may construct online opacity tables to be conveniently included in stellar evolution codes in the format most commonly adopted by stellar physicists, namely the OPAL format. This facility encourages the use and comparison of both the OPAL and OP data sets in applications. The present service allows for the calculation of multi-element mixtures containing the 17 species (H, He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Cr, Mn, Fe and Ni) considered by the OP, and underpins the latest release of OP opacities. This new service provides tables of Rosseland mean opacites using OP atomic data. We provide an alternative to the OPAL opacity services allowing direct comparison as well as study of the effect of uncertainties in stellar modeling due to mean opacities.

  14. IPOPv2 online service for the generation of opacity tables

    CERN Document Server

    Delahaye, F; Zeippen, C; Mendoza, C

    2015-01-01

    In the framework of the present phase -- IPOPv2 -- of the international Opacity Project (OP), a new web service has been implemented based on the latest release of the OP opacities. The user may construct online opacity tables to be conveniently included in stellar evolution codes in the format most commonly adopted by stellar physicists, namely the OPAL format. This facility encourages the use and comparison of both the OPAL and OP data sets in applications. The present service allows for the calculation of multi-element mixtures containing the 17 species (H, He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Cr, Mn, Fe and Ni) considered by the OP, and underpins the latest release of OP opacities. This new service provides tables of Rosseland mean opacites using OP atomic data. We provide an alternative to the OPAL opacity services allowing direct comparison as well as study of the effect of uncertainties in stellar modeling due to mean opacities.

  15. Solar Opacity Calculations Using the Super-transition-array Method

    Science.gov (United States)

    Krief, M.; Feigel, A.; Gazit, D.

    2016-04-01

    A new opacity model has been developed based on the Super-Transition-Array (STA) method for the calculation of monochromatic opacities of plasmas in local thermodynamic equilibrium. The atomic code, named STAR (STA-Revised), is described and used to calculate spectral opacities for a solar model implementing the recent AGSS09 composition. Calculations are carried out throughout the solar radiative zone. The relative contributions of different chemical elements and atomic processes to the total Rosseland mean opacity are analyzed in detail. Monochromatic opacities and charge-state distributions are compared with the widely used Opacity Project (OP) code, for several elements near the radiation-convection interface. STAR Rosseland opacities for the solar mixture show a very good agreement with OP and the OPAL opacity code throughout the radiation zone. Finally, an explicit STA calculation was performed of the full AGSS09 photospheric mixture, including all heavy metals. It was shown that, due to their extremely low abundance, and despite being very good photon absorbers, the heavy elements do not affect the Rosseland opacity.

  16. SOLAR OPACITY CALCULATIONS USING THE SUPER-TRANSITION-ARRAY METHOD

    Energy Technology Data Exchange (ETDEWEB)

    Krief, M.; Feigel, A.; Gazit, D., E-mail: menahem.krief@mail.huji.ac.il [The Racah Institute of Physics, The Hebrew University, 91904 Jerusalem (Israel)

    2016-04-10

    A new opacity model has been developed based on the Super-Transition-Array (STA) method for the calculation of monochromatic opacities of plasmas in local thermodynamic equilibrium. The atomic code, named STAR (STA-Revised), is described and used to calculate spectral opacities for a solar model implementing the recent AGSS09 composition. Calculations are carried out throughout the solar radiative zone. The relative contributions of different chemical elements and atomic processes to the total Rosseland mean opacity are analyzed in detail. Monochromatic opacities and charge-state distributions are compared with the widely used Opacity Project (OP) code, for several elements near the radiation–convection interface. STAR Rosseland opacities for the solar mixture show a very good agreement with OP and the OPAL opacity code throughout the radiation zone. Finally, an explicit STA calculation was performed of the full AGSS09 photospheric mixture, including all heavy metals. It was shown that, due to their extremely low abundance, and despite being very good photon absorbers, the heavy elements do not affect the Rosseland opacity.

  17. First solar models with OPAS opacity tables

    CERN Document Server

    Pennec, Maëlle Le; Salmon, Sébastien; Blancard, Christophe; Cossé, Philippe; Faussurier, Gérald; Mondet, Guillaume

    2015-01-01

    Stellar seismology appears more and more as a powerful tool for a better determination of the fundamental properties of solar-type stars. However the particular case of Sun is still challenging. The helioseismic sound speed determination continues to disagree with the Standard Solar Model (SSM) prediction for about a decade, questioning the reliability of this model. One of the sources of uncertainty could be in the treatment of the transport of radiation from the solar core to the surface. In this letter, we use the new OPAS opacity tables, recently available for solar modelling, to address this issue. We discuss first the peculiarities of these tables, then we quantify their impact on the solar sound speed and density profiles using the reduced OPAS tables taken on the grids of the OPAL ones. We use the two evolution codes MESA and CLES that led to similar conclusions in the solar radiative zone. In comparison to commonly used OPAL opacity tables, the new solar models computed, for the most recent photosphe...

  18. Calculation of Free-Free Opacities

    Science.gov (United States)

    Bhatia, A. K.; Maiden, D.; Ritchie, A. B., Jr.

    2003-01-01

    Free-free absorption is an important contribution to the opacity for radiation transport through hot materials Temperatures can be as high as several keV, such that it becomes a computational challenge to solve the Schrodinger equation efficiently for rapidly oscillating continuum functions for high angular momenta. Several groups\\footnots, including ours, have studied the phase amplitude solution (PAS) of the Schrodinger equation, in which one solves equations for the wave function amplitude and phase, which are: smooth functions of the electron energy. It is also important to have an accurate Schroudinger benchmark for the development of the PAS method. We present results for dipole matrix elements, Gaunt factors, and cross sections for the absorption of radiation at various energies for Cs XIX at temperature=100 eV and density=0.187 g/cc for our newly developed PAS and Schrodinger benchmark.

  19. Surgery for Pulmonary Multiple Ground Glass Opacities

    Directory of Open Access Journals (Sweden)

    Qun WANG

    2016-06-01

    Full Text Available The incidence of pulmonary ground glass opacity (GGO has been increasing in recent years, with a great number of patients having multiple GGOs. Unfortunately, the management of multiple GGOs is still controversial. Pulmonary GGO is a radiological term, consisting of different pathological types. Some of the GGOs are early-staged lung cancer. GGO is an indolent nodule, only a small proportion of GGOs change during observation, which does not influence the efficacy of surgery. . The timing of surgery for multiple GGOs mainly depends on the predominant nodule and surgery is recommended if the solid component of the predominant nodule >5 mm. Either lobectomy or sub-lobectomy is feasible. GGOs other than the predominant nodule can be left unresected. Multiple GGOs with high risk factors need mediastinal lymph node dissection or sampling.

  20. An opacity-sampled treatment of water vapor

    Science.gov (United States)

    Alexander, David R.; Augason, Gordon C.; Johnson, Hollis R.

    1989-01-01

    Although the bands of H2O are strong in the spectra of cool stars and calculations have repeatedly demonstrated their significance as opacity sources, only approximate opacities are currently available, due both to the difficulty of accounting for the millions of lines involved and to the inadequacy of laboratory and theoretical data. To overcome these obstacles, a new treatment is presented, based upon a statistical representation of the water vapor spectrum derived from available laboratory data. This statistical spectrum of water vapor employs an exponential distribution of line strengths and random positions of lines whose overall properties are forced to reproduce the mean opacities observed in the laboratory. The resultant data set is then treated by the opacity-sampling method exactly as are all other lines, both molecular and atomic. Significant differences are found between the results of this improved treatment and the results obtained with previous treatments of water-vapor opacity.

  1. A New Generation of Los Alamos Opacity Tables

    CERN Document Server

    Colgan, J; Magee, N H; Sherrill, M E; Abdallah,, J; Hakel, P; Fontes, C J; Guzik, J A; Mussack, K A

    2016-01-01

    We present a new, publicly available, set of Los Alamos OPLIB opacity tables for the elements hydrogen through zinc. Our tables are computed using the Los Alamos ATOMIC opacity and plasma modeling code, and make use of atomic structure calculations that use fine-structure detail for all the elements considered. Our equation-of-state (EOS) model, known as ChemEOS, is based on the minimization of free energy in a chemical picture and appears to be a reasonable and robust approach to determining atomic state populations over a wide range of temperatures and densities. In this paper we discuss in detail the calculations that we have performed for the 30 elements considered, and present some comparisons of our monochromatic opacities with measurements and other opacity codes. We also use our new opacity tables in solar modeling calculations and compare and contrast such modeling with previous work.

  2. Rosseland and Flux Mean Opacities for Compton Scattering

    Science.gov (United States)

    Poutanen, Juri

    2017-02-01

    Rosseland mean opacity plays an important role in theories of stellar evolution and X-ray burst models. In the high-temperature regime, when most of the gas is completely ionized, the opacity is dominated by Compton scattering. Our aim here is to critically evaluate previous works on this subject and to compute the exact Rosseland mean opacity for Compton scattering over a broad range of temperature and electron degeneracy parameter. We use relativistic kinetic equations for Compton scattering and compute the photon mean free path as a function of photon energy by solving the corresponding integral equation in the diffusion limit. As a byproduct we also demonstrate the way to compute photon redistribution functions in the case of degenerate electrons. We then compute the Rosseland mean opacity as a function of temperature and electron degeneracy and present useful approximate expressions. We compare our results to previous calculations and find a significant difference in the low-temperature regime and strong degeneracy. We then proceed to compute the flux mean opacity in both free-streaming and diffusion approximations, and show that the latter is nearly identical to the Rosseland mean opacity. We also provide a simple way to account for the true absorption in evaluating the Rosseland and flux mean opacities.

  3. Replicating the Z iron opacity experiments on the NIF

    Science.gov (United States)

    Perry, T. S.; Heeter, R. F.; Opachich, Y. P.; Ross, P. W.; Kline, J. L.; Flippo, K. A.; Sherrill, M. E.; Dodd, E. S.; DeVolder, B. G.; Cardenas, T.; Archuleta, T. N.; Craxton, R. S.; Zhang, R.; McKenty, P. W.; Garcia, E. M.; Huffman, E. J.; King, J. A.; Ahmed, M. F.; Emig, J. A.; Ayers, S. L.; Barrios, M. A.; May, M. J.; Schneider, M. B.; Liedahl, D. A.; Wilson, B. G.; Urbatsch, T. J.; Iglesias, C. A.; Bailey, J. E.; Rochau, G. A.

    2017-06-01

    X-ray opacity is a crucial factor of all radiation-hydrodynamics calculations, yet it is one of the least validated of the material properties in the simulation codes. Recent opacity experiments at the Sandia Z-machine have shown up to factors of two discrepancies between theory and experiment, casting doubt on the validity of the opacity models. Therefore, a new experimental opacity platform is being developed on the National Ignition Facility (NIF) not only to verify the Z-machine experimental results but also to extend the experiments to other temperatures and densities. The first experiments will be directed towards measuring the opacity of iron at a temperature of ∼160 eV and an electron density of ∼7 × 1021 cm-3. Preliminary experiments on NIF have demonstrated the ability to create a sufficiently bright point backlighter using an imploding plastic capsule and also a hohlraum that can heat the opacity sample to the desired conditions. The first of these iron opacity experiments is expected to be performed in 2017.

  4. Linear opacities on HRCT in bronchiolitis obliterans organising pneumonia

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, J.M.; Flower, C.D.R. [Dept. of Radiology, Addenbrookes Hospital, Univ. of Cambridge (United Kingdom); Schnyder, P.; Leuenberger, P. [Depts. of Radiology and Medicine, University Hospital, CHUV, Lausanne (Switzerland); Verschakelen, J. [Dept. of Radiology, University Hospital, Leuven (Belgium)

    1999-07-01

    The aim of this study was to report the high-resolution computed tomography (HRCT) appearances of linear opacities that may occur in isolation or in combination with other changes in bronchiolitis obliterans organising pneumonia (BOOP). Eleven patients with BOOP and linear opacities on HRCT were identified at three independent teaching hospitals. The HRCT images and clinical course of each patient were reviewed. Two distinct types of linear opacity were identified. The type-1 opacity extended in a radial manner along the line of the bronchi towards the pleura and was usually intimately related to bronchi. The type-2 opacity occurred in a sub-pleural location and bore no relationship to the bronchi. Both types occurred most commonly in the lower lobes, frequently were associated with multi-focal areas of consolidation and usually completely resolved with treatment. There was no associated bronchiectasis, irreversible volume loss or a reticular or honeycomb pattern. In 2 patients linear opacities were the sole abnormality on HRCT. Bronchiolitis obliterans organising pneumonia may occur in a pure ''linear form'' or HRCT may demonstrate linear opacities in addition to multi-focal consolidation. (orig.)

  5. Computing NLTE Opacities -- Node Level Parallel Calculation

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-09-11

    Presentation. The goal: to produce a robust library capable of computing reasonably accurate opacities inline with the assumption of LTE relaxed (non-LTE). Near term: demonstrate acceleration of non-LTE opacity computation. Far term (if funded): connect to application codes with in-line capability and compute opacities. Study science problems. Use efficient algorithms that expose many levels of parallelism and utilize good memory access patterns for use on advanced architectures. Portability to multiple types of hardware including multicore processors, manycore processors such as KNL, GPUs, etc. Easily coupled to radiation hydrodynamics and thermal radiative transfer codes.

  6. Calculation and Analysis of Mean Opacity of Gold Mixtures

    Institute of Scientific and Technical Information of China (English)

    YAN An-ying; JIANG Ming; CHENG Xin-lu; YANG Xiang-dong

    2007-01-01

    A screened hydrogenic model for l splitting (SHML) is used to calculate the Rosseland mean opacities of high-Z Au, Ta, Yb, Ho, Gd, Sm, Nd, Sn, Ag plasmas and mixtures of gold and these elements at high temperature (T=200-400eV) and dense (ρ=1g/cm3).From the calculated Rosseland mean opacities of the mixtures, Au-Nd seems to be a better choice than other mixtures.Simultaneously, the reason that the mean opacities of mixture of Au-Sn decrease slightly when T=400eV is analyzed.

  7. Opacity Calculations for Non-Local Thermodynamic Equilibrium Mixtures

    Institute of Scientific and Technical Information of China (English)

    吴泽清; 韩国兴; 逄锦桥

    2002-01-01

    Based on the average atom model, a non-local thermodynamic equilibrium (non-LTE) model is developed to calculate opacity for mixtures. This model could be applied to high-Z problems. The mean ionization degrees of SiO2 of the present calculation are slightly higher compared with another model for mixtures. As an example, the opacity of Au and Nd mixture is calculated. The results show concrete non-LTE effects and the increase in opacity of the mixture is shown clearly.

  8. Rosseland and flux mean opacities for Compton scattering

    CERN Document Server

    Poutanen, Juri

    2016-01-01

    Rosseland mean opacity plays an important role in theories of stellar evolution and X-ray burst models. In the high-temperature regime, when most of the gas is completely ionized, the opacity is dominated by Compton scattering. Our aim here is to critically evaluate previous works on this subject and to compute exact Rosseland mean opacity for Compton scattering in a broad range of temperatures and electron degeneracy parameter. We use relativistic kinetic equations for Compton scattering and compute the photon mean free path as a function of photon energy by solving the corresponding integral equation in the diffusion limit. As a byproduct we also demonstrate the way to compute photon redistribution functions in case of degenerate electrons. We then compute the Rosseland mean opacity as a function of temperature and electron degeneracy. We compare our results to the previous calculations and find a significant difference in the low-temperature regime and strong degeneracy. We find useful analytical expressio...

  9. Is Seeing Believing? Consumer Responses to Opacity of Product Packaging

    National Research Council Canada - National Science Library

    Sucharita Chandran; Rishtee Kumar Batra; Benjamin Lawrence

    2009-01-01

      Prior studies have shown that product and packaging design influences consumer reactions and purchase behaviors, however, research has neglected to examine a package's opacity or lack of transparency...

  10. Opacity Experiments At The National Ignition Facility (NIF)

    Science.gov (United States)

    Perry, T. S.; Kline, J. L.; Flippo, K. A.; Sherrill, M. E.; Dodd, E. S.; Devolder, B. G.; Urbatsch, T. J.; Heeter, R. F.; Schneider, M. B.; Liedahl, D. A.; Wilson, B. G.; Iglesias, C. A.; Opachich, Y. P.; Ross, P. W.; Bailey, J. E.; Rochau, G. A.

    2016-10-01

    X-ray opacities are essential to the radiation-hydrodynamic simulations used to model astrophysical systems or inertial confinement fusion experiments. Recent opacity experiments have shown up to a factor of two discrepancy between theory and experiment. To address this issue a new experimental opacity platform is being developed on the NIF to crosscheck the recent results. The first experiments, starting in 2017, will begin by measuring the opacity of iron at a temperature of 160 eV and an electron density of 7x1021 cm-3. This and several following presentations will describe this effort. This work was performed under the auspices of the U.S. Department of Energy by Los Alamos National Lab under Contract DE-AC52-06NA25396.

  11. Experiment to measure oxygen opacity at high density and temperature

    Science.gov (United States)

    Keiter, Paul; Mussack, Katie; Orban, Chris; Colgan, James; Ducret, Jean-Eric; Fontes, Christopher J.; Guzik, Joyce Ann; Heeter, Robert F.; Kilcrease, Dave; Le Pennec, Maelle; Mancini, Roberto; Perry, Ted; Turck-Chièze, Sylvaine; Trantham, Matt

    2017-06-01

    In recent years, there has been a debate over the abundances of heavy elements (Z >2) in the solar interior. Recent solar atmosphere models [Asplund 2009] find a significantly lower abundance for C, N, and O compared to models used roughly a decade ago. This discrepancy has led to an investigation of opacities through laboratory experiments and improved opacity models for many of the larger contributors to the sun’s opacity, including iron and oxygen. Recent opacity measurements of iron disagree with opacity model predictions [Bailey et al, 2015]. Although these results are still controversial, repeated scrutiny of the experiment and data has not produced a conclusive reason for the discrepancy. New models have been implemented in the ATOMIC opacity code for C, O and Fe to address the solar abundance issue [Colgan, 2013]. Armstrong et al [2014] have also implemented changes in the ATOMIC code for low-Z elements. However, no data currently exists to test the low-Z material models in the regime relevant to the solar convection zone. We present an experimental design using the opacity platform developed at the National Ignition Facility to study the oxygen opacity at densities and temperatures near the solar convection zone conditions.This work is funded by the U.S. DOE, through the NNSA-DS and SC-OFES Joint Program in HEDPLP, grant No. DE-NA0001840, and the NLUF Program, grant No. DE-NA0000850, and through LLE, University of Rochester by the NNSA/OICF under Agreement No. DE-FC52-08NA28302.

  12. Analytical expressions for radiative opacities of low Z plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Rubiano, J G; Martel, P; Gil, J M; Rodriguez, R; Florido, R; Mendoza, M A [Departamento de Fisica, Universidad de Las Palmas de GC, Las Palmas de GC (Spain); Minguez, E, E-mail: jgarcia@dfis.ulpgc.e [Instituto de Fusion Nuclear (DENIM), Universidad Politecnica de Madrid, Madrid (Spain)

    2010-08-01

    In this work we obtain analytical expressions for the radiative opacity of several low Z plasmas (He, Li, Be, and B) in a wide range of temperatures and densities. These formulas are obtained by fitting the proposed expression to mean opacities data calculated by using the code ABAKO/ RAPCAL. This code computes the radiative properties of plasmas, both in LTE and NLTE conditions, under the detailed-level-accounting approach. It has been successfully validated in the range of interest in previous works.

  13. Opacity spectra of silicon and carbon in ICF plasmas

    Science.gov (United States)

    Benredjem, D.; Calisti, A.; Ferri, S.; Gilleron, F.; Mondet, G.; Pain, J.-C.

    2017-03-01

    The knowledge of opacity is very important when one investigates the radiative properties of ICF and astrophysical plasmas. Germanium and silicon are good candidates as dopants in the ablator of some ICF schemes (LMJ in France, NIF at Livermore). In this work we calculate the opacity spectra of silicon and carbon mixtures. Two competitive methods were used. The first one is based on a detailed line calculation in which the atomic database is provided by the MCDF code. A lineshape code based on a fast algorithm was then adapted to the calculation of opacity profiles. All major line broadening mechanisms, including Zeeman splitting and Stark effect, are taken into account. This approach provides accurate opacity spectra but becomes rapidly prohibitive when the number of lines is large. To account for systems involving many ionic stages and thousands of lines, a second approach combines detailed line calculations and statistical calculations. This approach necessitates much smaller calculation times than the first one and is then more appropriate for extensive calculations. The monochromatic opacity and the Rosseland and Planck mean opacities are calculated for relevant densities and temperatures.

  14. Computational design of short pulse laser driven iron opacity experiments

    Science.gov (United States)

    Martin, M. E.; London, R. A.; Goluoglu, S.; Whitley, H. D.

    2017-02-01

    The resolution of current disagreements between solar parameters calculated from models and observations would benefit from the experimental validation of theoretical opacity models. Iron's complex ionic structure and large contribution to the opacity in the radiative zone of the sun make iron a good candidate for validation. Short pulse lasers can be used to heat buried layer targets to plasma conditions comparable to the radiative zone of the sun, and the frequency dependent opacity can be inferred from the target's measured x-ray emission. Target and laser parameters must be optimized to reach specific plasma conditions and meet x-ray emission requirements. The HYDRA radiation hydrodynamics code is used to investigate the effects of modifying laser irradiance and target dimensions on the plasma conditions, x-ray emission, and inferred opacity of iron and iron-magnesium buried layer targets. It was determined that plasma conditions are dominantly controlled by the laser energy and the tamper thickness. The accuracy of the inferred opacity is sensitive to tamper emission and optical depth effects. Experiments at conditions relevant to the radiative zone of the sun would investigate the validity of opacity theories important to resolving disagreements between solar parameters calculated from models and observations.

  15. Recursive method for opacity expansion at finite temperature%Recursive method for opacity expansion at finite temperature

    Institute of Scientific and Technical Information of China (English)

    刘嘉; 康忠波; 王恩科

    2011-01-01

    Using a reaction operator approach, we derive the multiple-scattering induced gluon number distribution function to all orders in powers of opacity at finite temperature. The detailed balance effect is analyzed by taking into account both gluon emission a

  16. Pentacam-based phototherapeutic keratectomy outcome in superficial corneal opacities

    Directory of Open Access Journals (Sweden)

    Rashad MA

    2012-06-01

    Full Text Available Mohammad A RashadOphthalmology Department, Faculty of Medicine, Ain Shams University, Cairo, EgyptPurpose: This study aimed to evaluate the effectiveness of phototherapeutic keratectomy (PTK as an alternative treatment to keratoplasty using the Pentacam to assess depth of dense opacities.Methodology: PTK was performed in eleven eyes of ten patients with superficial corneal opacities after assessment by Scheimpflug images of the Pentacam for central corneal thickness (CCT and opacity level and depth.Results: The best-corrected spectacle visual acuity (BCSVA significantly improved. The preoperative mean logMAR was 0.85 (0.14 decimal equivalent, 6/42 Snellen's equivalent, and the final postoperative mean logMAR was 0.58 (0.26 decimal equivalent, 6/23 Snellen's equivalent. The mean preoperative CCT was 465.64 ± 71.94 µm. The mean programmed ablation depth was 142.09 ± 47.58 µm. The programmed ablation depth was correlated to mean logMAR early (1 month and not correlated later (6 months. None of the eyes lost lines of BCSVA or developed serious complications, such as keratectasia, delayed epithelialization, or corneal melting.Conclusion: Corneal scars extending beyond the anterior one-fifth of the cornea can be treated safely and effectively by PTK due to the smoothing effect, with reduction of the cylinder rather than complete opacity removal. This can decrease the need for keratoplasty.Keywords: phototherapeutic keratectomy, PTK, corneal opacities, Pentacam

  17. 225 GHz Atmospheric Opacity Measurements from Two Arctic Sites

    CERN Document Server

    Matsushita, S; Martin-Cocher, P; Asada, K; Chen, C -P; Inoue, M; Paine, S; Turner, D; Steinbring, E

    2012-01-01

    We report the latest results of 225 GHz atmospheric opacity measurements from two arctic sites; one on high coastal terrain near the Eureka weather station, on Ellesmere Island, Canada, and the other at the Summit Station near the peak of the Greenland icecap. This is a campaign to search for a site to deploy a new telescope for submillimeter Very Long Baseline Interferometry and THz astronomy in the northern hemisphere. Since 2011, we have obtained 3 months of winter data near Eureka, and about one year of data at the Summit Station. The results indicate that these sites offer a highly transparent atmosphere for observations in submillimeter wavelengths. The Summit Station is particularly excellent, and its zenith opacity at 225 GHz is statistically similar to the Atacama Large Milllimeter/submillimeter Array in Chile. In winter, the opacity at the Summit Station is even comparable to that observed at the South Pole.

  18. Age of old objects constraints on cosmic opacity

    CERN Document Server

    Holanda, R F L; Dantas, M A

    2016-01-01

    In this paper, it is proposed a cosmological model independent method to constrain the cosmic opacity. As an approach never seen before in literature, we use the ages of 32 old passive galaxies distributed over the redshift interval $0.11 < z < 1.84$ and of 9 extremely old globular clusters in M31 galaxy to obtain opacity free luminosity distance. By comparing them to the 580 distance moduli of supernovae from the so-called Union 2.1 compilation we put limits on the cosmic opacity parametrized by $\\tau(z) = \\epsilon z/(1+z)$ (for $\\epsilon =0$ the transparent universe is recovered). Considering the cosmic background radiation constraints on the spatial curvature of the Universe no significant deviation from transparency is verified.

  19. Design And First Use of the NIF Opacity Spectrometer

    Science.gov (United States)

    King, J. A.; Ross, P. W.; Huffman, E. J.; Opachich, Y. P.; Heeter, R. F.; Ahmed, M.; Liedahl, D. A.; Schneider, M. B.; Dodd, E.; Flippo, K. A.; Kline, J. L.; Lopez, F. E.; Archuleta, T. N.; Perry, T. S.

    2016-10-01

    Recent experiments at the Sandia Z facility have raised questions about models used in calculating L-shell opacities of mid-Z elements. A platform is being developed to check these results at the National Ignition Facility (NIF). The NIF experiments require a new X-ray opacity spectrometer (OpSpec) for the iron L-shell X-ray band, spanning photon energies from 540 eV - 2100 eV with a resolving power E/ ΔE >700. The design of the OpSpec and photometric calculations based on expected opacity data are also presented. First use on NIF is expected in September 2016. This work was performed by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. DOE/NV/25946-2891.

  20. Infrared Opacities in Dense Atmospheres of Cool White Dwarf Stars

    CERN Document Server

    Kowalski, Piotr M; Dufour, Patrick

    2016-01-01

    Dense, He-rich atmospheres of cool white dwarfs represent a challenge to the modeling. This is because these atmospheres are constituted of a dense fluid in which strong multi-atomic interactions determine their physics and chemistry. Therefore, the ideal-gas-based description of absorption is no longer adequate, which makes the opacities of these atmospheres difficult to model. This is illustrated with severe problems in fitting the spectra of cool, He-rich stars. Good description of the infrared (IR) opacity is essential for proper assignment of the atmospheric parameters of these stars. Using methods of computational quantum chemistry we simulate the IR absorption of dense He/H media. We found a significant IR absorption from He atoms (He-He-He CIA opacity) and a strong pressure distortion of the H$_2$-He collision-induced absorption (CIA). We discuss the implication of these results for interpretation of the spectra of cool stars.

  1. Fractal Particles: Titan's Thermal Structure and IR Opacity

    Science.gov (United States)

    McKay, C. P.; Rannou, P.; Guez, L.; Young, E. F.; DeVincenzi, Donald (Technical Monitor)

    1998-01-01

    Titan's haze particles are the principle opacity at solar wavelengths. Most past work in modeling these particles has assumed spherical particles. However, observational evidence strongly favors fractal shapes for the haze particles. We consider the implications of fractal particles for the thermal structure and near infrared opacity of Titan's atmosphere. We find that assuming fractal particles with the optical properties based on laboratory tholin material and with a production rate that allows for a match to the geometric albedo results in warmer troposphere and surface temperatures compared to spherical particles. In the near infrared (1-3 microns) the predicted opacity of the fractal particles is up to a factor of two less than for spherical particles. This has implications for the ability of Cassini to image Titan's surface at 1 micron.

  2. Infrared Opacities in Dense Atmospheres of Cool White Dwarf Stars

    Science.gov (United States)

    Kowalski, P. M.; Blouin, S.; Dufour, P.

    2017-03-01

    Dense, He-rich atmospheres of cool white dwarfs represent a challenge to the modeling. This is because these atmospheres are constituted of a dense fluid in which strong multi-atomic interactions determine their physics and chemistry. Therefore, the ideal-gas-based description of absorption is no longer adequate, which makes the opacities of these atmospheres difficult to model. This is illustrated with severe problems in fitting the spectra of cool, He-rich stars. Good description of the infrared (IR) opacity is essential for proper assignment of the atmospheric parameters of these stars. Using methods of computational quantum chemistry we simulate the IR absorption of dense He/H media. We found a significant IR absorption from He atoms (He-He-He CIA opacity) and a strong pressure distortion of the H2-He collision-induced absorption (CIA). We discuss the implication of these results for the interpretation of the spectra of cool stars.

  3. Verification of Opacity and Diagnosability for Pushdown Systems

    Directory of Open Access Journals (Sweden)

    Koichi Kobayashi

    2013-01-01

    Full Text Available In control theory of discrete event systems (DESs, one of the challenging topics is the extension of theory of finite-state DESs to that of infinite-state DESs. In this paper, we discuss verification of opacity and diagnosability for infinite-state DESs modeled by pushdown automata (called here pushdown systems. First, we discuss opacity of pushdown systems and prove that opacity of pushdown systems is in general undecidable. In addition, a decidable class is clarified. Next, in diagnosability, we prove that under a certain assumption, which is different from the assumption in the existing result, diagnosability of pushdown systems is decidable. Furthermore, a necessary condition and a sufficient condition using finite-state approximations are derived. Finally, as one of the applications, we consider data integration using XML (Extensible Markup Language. The obtained result is useful for developing control theory of infinite-state DESs.

  4. Measuring the opacity of stellar interior matter in terrestrial laboratories

    Science.gov (United States)

    Bailey, James

    2015-11-01

    How does energy propagate from the core to the surface of the Sun, where it emerges to warm the Earth? Nearly a century ago Eddington recognized that the attenuation of radiation by stellar matter controls the internal structure of stars like the sun. Opacities for high energy density (HED) matter are challenging to calculate because accurate and complete descriptions of the energy levels, populations, and plasma effects such as continuum lowering and line broadening are needed for partially ionized atoms. This requires approximations, in part because billions of bound-bound and bound-free electronic transitions can contribute to the opacity. Opacity calculations, however, have never been benchmarked against laboratory measurements at stellar interior conditions. Laboratory opacity measurements were limited in the past by the challenges of creating and diagnosing sufficiently large and uniform samples at the extreme conditions found inside stars. In research conducted over more than 10 years, we developed an experimental platform on the Z facility and measured wavelength-resolved iron opacity at electron temperatures Te = 156-195 eV and densities ne = 0.7-4.0 x 1022 cm-3 - conditions very similar to the radiation/convection boundary zone within the Sun. The wavelength-dependent opacity in the 975-1775 eV photon energy range is 30-400% higher than models predict. This raises questions about how well we understand the behavior of atoms in HED plasma. These measurements may also help resolve decade-old discrepancies between solar model predictions and helioseismic observations. This talk will provide an overview of the measurements, investigations of possible errors, and ongoing experiments aimed at testing hypotheses to resolve the model-data discrepancy. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

  5. FTS Measurements of Submillimeter-Wave Atmospheric Opacity at Pampa la Bola: III. Water Vapor, Liquid Water, and 183GHz Water Vapor Line Opacities

    Science.gov (United States)

    Matsushita, Satoki; Matsuo, Hiroshi

    2003-02-01

    Further analysis has been made on the millimeter- and submillimeter-wave (100-1600GHz or 3mm-188 μm) atmospheric opacity data taken with the Fourier Transform Spectrometer (FTS) at Pampa la Bola, 4800 m above the sea level in northern Chile, which is the site of the Atacama Large Millimeter/submillimeter Array (ALMA). Time-sequence plots of millimeter- and submillimeter-wave opacities show similar variations to each other, except for during the periods with liquid water (fog or clouds) in the atmosphere. Using millimeter- and submillimeter-wave opacity correlations under two conditions, which are affected and not affected by liquid water, we succeeded to separate the measured opacity into water vapor and liquid water opacity components. The water vapor opacity shows a good correlation with the 183GHz water vapor line opacity, which is also covered in the measured spectra. On the other hand, the liquid water opacity and the 183GHz line opacity show no correlation. S ince only the water vapor component is expected to affect the phase of interferometers significantly, and the submillimeter-wave opacity is less affected by the liquid water component, it may be possible to use the submillimeter-wave opacity for a phase correction of submillimeter interferometers.

  6. The Non-local Thermodynamical Equilibrium Effects on Opacity

    Institute of Scientific and Technical Information of China (English)

    WU Ze-Qing; ZHANG Ben-Ai; QIU Yu-Bo

    2001-01-01

    Based on the detailed configuration accounting (DCA) model, a method is developed to include the resonant photoionization and the excitation-autoionization in the non-local thermodynamical equilibrium (NLTE) average atom(AA) model. Using this new model, the mean charge states and the opacity are calculated for NLTE high-Z plasmas and compared with other results. The agreement w ith AA model is poor at low electron density. The present results agree well with those of DCA model within 10%. The calculations show that the NLTE effects on opacity are strong.

  7. Model-independent constraints on the cosmic opacity

    CERN Document Server

    Holanda, R F L; Alcaniz, J S

    2012-01-01

    We use current measurements of the expansion rate $H(z)$ and cosmic background radiation bounds on the spatial curvature of the Universe to impose cosmological model-independent constraints on cosmic opacity. To perform our analyses, we compare opacity-free distance modulus from $H(z)$ data with those from two supernovae Ia compilations, namely, the Union2 and Sloan Digital Sky Survey samples. The influence of different SNe Ia light-curve fitters (SALT2 and MLCS2K2) on the results is also discussed. We find that these fitters present a significant conflict, with the MLCS2K2 method being incompatible with a flat and transparent universe.

  8. Ultra-dense Hot Low Z Line Transition Opacity Simulations

    Science.gov (United States)

    Sauvan, P.; Mínguez, E.; Gil, J. M.; Rodríguez, R.; Rubiano, J. G.; Martel, P.; Angelo, P.; Schott, R.; Philippe, F.; Leboucher-Dalimier, E.; Mancini, R.; Calisti, A.

    2002-12-01

    In this work two atomic physics models (the IDEFIX code using the dicenter model and the code based on parametric potentials ANALOP) have been used to calculate the opacities for bound-bound transitions in hot ultra-dense, low Z plasmas. These simulations are in connection with experiments carried out at LULI during the last two years, focused on bound-bound radiation. In this paper H-like opacities for aluminum and fluorine plasmas have been simulated, using both theoretical models, in a wide range of densities and temperatures higher than 200 eV.

  9. FIRST NEW SOLAR MODELS WITH OPAS OPACITY TABLES

    Energy Technology Data Exchange (ETDEWEB)

    Le Pennec, M.; Turck-Chièze, S.; Salmon, S. [CEA/IRFU/Service d’Astrophysique, CE Saclay, F-91191 Gif sur Yvette (France); Blancard, C.; Cossé, P.; Faussurier, G.; Mondet, G. [CEA, DAM, DIF, F-91297 Arpajon (France)

    2015-11-10

    Stellar seismology appears more and more as a powerful tool for a better determination of the fundamental properties of solar-type stars. However, the particular case of the Sun is still challenging. For about a decade now, the helioseismic sound-speed determination has continued to disagree with the standard solar model (SSM) prediction, questioning the reliability of this model. One of the sources of uncertainty could be in the treatment of the transport of radiation from the solar core to the surface. In this Letter, we use the new OPAS opacity tables, recently available for solar modeling, to address this issue. We discuss first the peculiarities of these tables, then we quantify their impact on the solar sound-speed and density profiles using the reduced OPAS tables taken on the grids of the OPAL ones. We use the two evolution codes, Modules for Experiments in Stellar Astrophysics and Code Liégeois d’Evolution Stellaire, that led to similar conclusions in the solar radiative zone. In comparison to commonly used OPAL opacity tables, the new solar models are computed for the most recent photospheric composition with OPAS tables and present improvements to the location of the base of the convective zone and to the description of the solar radiative zone in comparison to the helioseismic observations, even if the differences in the Rosseland mean opacity do not exceed 6%. We finally carry out a comparison to a solar model computed with the OP opacity tables.

  10. Design Parameter Studies of Emission-Based Iron Opacity Measurements

    Science.gov (United States)

    Martin, Madison E.; London, Richard A.; Goluoglu, Sedat; Whitley, Heather D.

    2016-10-01

    Opacity is a critical parameter in the transport of radiation in systems such as inertial confinement fusion capsules and stars. The resolution of current disagreements between solar models and helioseismological observations would benefit from experimental validation of theoretical opacity models. Short pulse lasers can be used to heat targets to higher temperatures and densities than long pulse lasers and pulsed power machines, thus potentially enabling access to x-ray emission spectra at conditions relevant to solar models. The radiation-hydrodynamic code HYDRA is used to investigate the effects of modifying laser energy, laser pulse length, and target dimensions on the plasma conditions, x-ray emission, and inferred opacity of a buried layer iron target. The accuracy of the opacity inference is sensitive to tamper emission and optical depth effects. An example design that reaches temperatures and densities relevant to the radiative zone of the sun while reducing optical depth and tamper emission effects will be discussed. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC.

  11. 40 CFR 75.14 - Specific provisions for monitoring opacity.

    Science.gov (United States)

    2010-07-01

    ... calendar year. (d) Diesel-fired units and dual-fuel reciprocating engine units. The owner or operator of an affected diesel-fired unit or a dual-fuel reciprocating engine unit is exempt from the opacity monitoring... unit by changing its fuel mix, the owner or operator shall install, operate, and certify a continuous...

  12. The fog of change : opacity and asperity in organizations.

    OpenAIRE

    Hannan, M.T.; Pólos, L.; Carroll, G.R.

    2003-01-01

    Initial architectural change in organizations often induces other subsequent changes, generating lengthy cascades of changes in subordinate units. This article extends a formal model of cascading organizational change by examining the implications for organizational change of the limited foresight of those who initiate such change about unit interconnections (structural opacity) and the normative restrictiveness imposed on architectural features by organizational culture (cultural asperity). ...

  13. FTS measurements of submillimeter-wave opacity at Pampa la Bola

    Science.gov (United States)

    Matsuo, Hiroshi; Sakamoto, Akihiro; Matsushita, Satoki

    1998-07-01

    The first measurement of submillimeter-wave atmospheric opacity spectra at the Pampa la Bola site (Northern Chile, Atacama 4800 m altitude) has been performed during the winter season using a Fourier transform spectrometer (FTS). Atmospheric emission spectra, as a function of airmass, were measured under various weather conditions. Atmospheric opacity was evaluated from sky temperature at zenith as well as from tipping measurements, which are independent measure but give consistent results. The FTS opacity measurements also show good match with 220 GHz radiometer measurements. Correlations between millimeter-wave and submillimeter-wave opacities get worse when 220 GHz opacity is larger than 0.1. Deviations from the opacity correlation at each frequency show good correlations themselves but have different relative variations at each frequency. This indicates that atmospheric transparency cannot be characterized only by millimeter-wave opacity buy requires simultaneous opacity measurements at millimeter and submillimeter-wavelengths.

  14. 77 FR 13997 - Quality Assurance Requirements for Continuous Opacity Monitoring Systems at Stationary Sources

    Science.gov (United States)

    2012-03-08

    ... AGENCY 40 CFR Part 60 RIN 2060-AH23 Quality Assurance Requirements for Continuous Opacity Monitoring... rule titled, ``Quality Assurance Requirements for Continuous Opacity Monitoring Systems at Stationary....regulations.gov or in hard copy at the Procedure 3--Quality Assurance Requirements for Continuous Opacity...

  15. EVIDENCE FOR ENVIRONMENTAL CHANGES IN THE SUBMILLIMETER DUST OPACITY

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Peter G.; Roy, Arabindo; Miville-Deschenes, Marc-Antoine [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Bontemps, Sylvain [Observatoire de Bordeaux, BP 89, F-33270 Floirac (France); Ade, Peter A. R.; Griffin, Matthew; Hargrave, Peter C.; Mauskopf, Philip [Department of Physics and Astronomy, Cardiff University, 5 The Parade, Cardiff, CF24 3AA (United Kingdom); Bock, James J. [Jet Propulsion Laboratory, Pasadena, CA 91109-8099 (United States); Chapin, Edward L.; Halpern, Mark; Marsden, Gaelen [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1 (Canada); Devlin, Mark J.; Dicker, Simon R.; Klein, Jeff [Department of Physics and Astronomy, University of Pennsylvania, 209 South 33rd Street, Philadelphia, PA 19104 (United States); Gundersen, Joshua O. [Department of Physics, University of Miami, 1320 Campo Sano Drive, Carol Gables, FL 33146 (United States); Hughes, David H. [Instituto Nacional de Astrofisica Optica y Electronica (INAOE), Aptdo. Postal 51 y 72000 Puebla (Mexico); Netterfield, Calvin B. [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Olmi, Luca [INAF, Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 (Italy); Patanchon, Guillaume [Laboratoire APC, 10, rue Alice Domon et Leonie Duquet F-75205 Paris (France); and others

    2012-05-20

    The submillimeter opacity of dust in the diffuse interstellar medium (ISM) in the Galactic plane has been quantified using a pixel-by-pixel correlation of images of continuum emission with a proxy for column density. We used multi-wavelength continuum data: three Balloon-borne Large Aperture Submillimeter Telescope bands at 250, 350, and 500 {mu}m and one IRAS band at 100 {mu}m. The proxy is the near-infrared color excess, E(J - K{sub s}), obtained from the Two Micron All Sky Survey. Based on observations of stars, we show how well this color excess is correlated with the total hydrogen column density for regions of moderate extinction. The ratio of emission to column density, the emissivity, is then known from the correlations, as a function of frequency. The spectral distribution of this emissivity can be fit by a modified blackbody, whence the characteristic dust temperature T and the desired opacity {sigma}{sub e}(1200) at 1200 GHz or 250 {mu}m can be obtained. We have analyzed 14 regions near the Galactic plane toward the Vela molecular cloud, mostly selected to avoid regions of high column density (N{sub H} > 10{sup 22} cm{sup -2}) and small enough to ensure a uniform dust temperature. We find {sigma}{sub e}(1200) is typically (2-4) Multiplication-Sign 10{sup -25} cm{sup 2} H{sup -1} and thus about 2-4 times larger than the average value in the local high Galactic latitude diffuse atomic ISM. This is strong evidence for grain evolution. There is a range in total power per H nucleon absorbed (and re-radiated) by the dust, reflecting changes in the strength of the interstellar radiation field and/or the dust absorption opacity. These changes in emission opacity and power affect the equilibrium T, which is typically 15 K, colder than at high latitudes. Our analysis extends, to higher opacity and lower temperature, the trend of increasing {sigma}{sub e}(1200) with decreasing T that was found at high latitudes. The recognition of changes in the emission opacity

  16. Nuclear reaction rates and opacity in massive star evolution calculations

    Energy Technology Data Exchange (ETDEWEB)

    Bahena, D [Astronomical Institute of the Academy of Sciences, BocnI II 1401, 14131 Praha 4 (Czech Republic); Klapp, J [Instituto Nacional de Investigaciones Nucleares, Km. 36.5 Carr. Mexico-Toluca, 52750 Edo. de Mexico (Mexico); Dehnen, H, E-mail: jaime.klapp@inin.gob.m [Universitaet Konstanz, Fachbereich Physik, Fach M568, D-78457 Konstanz (Germany)

    2010-07-01

    Nuclear reaction rates and opacity are important parameters in stellar evolution. The input physics in a stellar evolution code determines the main theoretical characteristics of the stellar structure, evolution and nucleosynthesis of a star. For different input physics, in this work we calculate stellar evolution models of very massive first stars during the hydrogen and helium burning phases. We have considered 100 and 200M{sub s}un galactic and pregalactic stars with metallicity Z = 10{sup -6} and 10{sup 9}, respectively. The results show important differences from old to new formulations for the opacity and nuclear reaction rates, in particular the evolutionary tracks are significantly affected, that indicates the importance of using up to date and reliable input physics. The triple alpha reaction activates sooner for pregalactic than for galactic stars.

  17. Towards a new model of OPAC. From information to knowledge.

    Directory of Open Access Journals (Sweden)

    Antonella Iacono

    2013-07-01

    Full Text Available Il contributo analizza l’evoluzione dei cataloghi elettronici delle biblioteche alla luce delle nuove tecnologie del Web semantico e dei linked data. La trattazione è suddivisa in due parti distinte. In questa prima parte muovendo da un’analisi critica del modello funzionale degli ‘OPAC di nuova generazione’ e discovery tools si propone la necessità di una revisione del paradigma corrente di sviluppo che accogliendo le teorie dell’information behavior possa fondarsi sull'utente, sui suoi bisogni informativi, i suoi comportamenti e sull'analisi delle componenti che entrano in gioco nel processo di ricerca dell'informazione.Nella seconda parte, di prossima pubblicazione si è esplorerà la possibilità che i linked data possano essere la tecnologia più appropriata per la costruzione di nuovi OPAC basati sulla produzione di conoscenza all’interno del processo informativo. 

  18. Model-independent constraints on the cosmic opacity

    Energy Technology Data Exchange (ETDEWEB)

    Holanda, R.F.L. [Departamento de Física, Universidade Estadual da Paraíba, 58429-500, Campina Grande - PB (Brazil); Carvalho, J.C.; Alcaniz, J.S., E-mail: holanda@uepb.edu.br, E-mail: carvalho@dfte.ufrn.br, E-mail: alcaniz@on.br [Departamento de Astronomia, Observatório Nacional, 20921-400, Rio de Janeiro - RJ (Brazil)

    2013-04-01

    We use current measurements of the expansion rate H(z) and cosmic background radiation bounds on the spatial curvature of the Universe to impose cosmological model-independent constraints on cosmic opacity. To perform our analyses, we compare opacity-free distance modulus from H(z) data with those from two type Ia supernovae compilations, namely, the Union2.1 plus the most distant spectroscopically confirmed SNe Ia (SCP-0401 at z = 1.713) and two Sloan Digital Sky Survey (SDSS) subsamples. We find that a completely transparent universe is in full agreement with the Union 2.1 + SNe Ia SCP-0401 sample. For the SDSS compilations, such universe is compatible with observations at < 1.5σ level regardless the SNe Ia light-curve fitting used.

  19. Design of Initial Opacity Platform at the National Ignition Facility

    Science.gov (United States)

    Heeter, R. F.; Ahmed, M. F.; Ayers, S. L.; Emig, J. A.; Iglesias, C. A.; Liedahl, D. A.; Schneider, M. B.; Wilson, B. G.; Huffman, E. J.; King, J. A.; Opachich, Y. P.; Ross, P. W.; Bailey, J. E.; Rochau, G. A.; Craxton, R. S.; Garcia, E. M.; McKenty, P. W.; Zhang, R.; Cardenas, T.; Devolder, B. G.; Dodd, E. S.; Kline, J. L.; Sherrill, M. E.; Perry, T. S.

    2016-10-01

    The absorption and re-emission of x-rays by partly stripped ions plays a critical role in stars and in many laboratory plasmas. A NIF Opacity Platform has been designed to resolve a persistent disagreement between theory and experiments on the Sandia Z facility, studying iron in conditions closely related to the solar radiation-convection transition boundary. A laser heated hohlraum ``oven'' will produce iron plasmas at temperatures >150 eV and electron densities >=7x1021/cm3, and be probed with continuum X-rays from a capsule implosion backlighter source. The resulting X-ray transmission spectra will be recorded on a specially designed Opacity Spectrometer. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

  20. Equation of state and opacities for warm dense matter

    Directory of Open Access Journals (Sweden)

    Cotelo Manuel

    2013-11-01

    Full Text Available This work presents recent developments in the calculation of opacity and equation of state tables suitable for including in the radiation hydrodynamic code ARWEN [1] to study processes like ICF or X-ray secondary sources. For these calculations we use the code bigbart to compute opacities in LTE conditions, with self-consistent data generated with the Flexible Atomic Code (FAC [2]. Non-LTE effects are approximately taken into account by means of the new RADIOM model developed in [3], which makes use of existing LTE data tables. We use the screened-hydrogenic model [4] to derive the Equation of State (EOS using the population and energy of each level.

  1. Skewed gas flow technology offers antidote to opacity derates

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, M. [ATCO Power AB (Canada). Battle River Generating Station

    2001-06-01

    Deratings due to opacity problems at the Battle River Generating Station in Alberta, Canada led ATCO Power to evaluate and install skewed gas flow technology (SGFT) in one-half of the Unit 5 twin-casing electrostatic precipitator during the August 2000 outage. Preliminary operating results show that the modified casing produces opacity readings at the outlet 40% lower than those seen at the outlet of the unmodified casing. The dust loading tests indicate a 27.5% improvement in collector efficiency. This article includes a technical review and evaluation of Battle River's SGFT installation, as well as the rationale used to provide the initial economic justification. 3 figs., 1 tab., 1 photo.

  2. Opacity calculations for Non-Local-Thermodynamic-Equilibrium plasmas

    Institute of Scientific and Technical Information of China (English)

    PANG Jin-qiao; WU Ze-qing; YAN Jun; HAN Guo-xing

    2004-01-01

    In this paper, we presented a method to calculate the spectral-resolved opacity for Non-Local-Thermodynamic-Equilibrium (non-LTE) plasmas. By solving the rate equations, we get the population. In the rate equations, configuration-averaged rate coefficients are used and the cross sections are calculated based on the first-perturbation theory. Using the detailed configuration accounting with the term structures treated by the unresolved transition array model, we calculated the spectral-resolved opacity of Al plasmas. The results are compared with those of other theoretical models. From the comparison, we can see that the present results fit well with other models for low-Z plasmas. For high-Z plasmas, we will give detailed discussion in the future.

  3. [Glycosaminoglycans in subepithelial opacity after excimer laser keratectomy].

    Science.gov (United States)

    Nakayasu, K; Gotoh, T; Ishikawa, T; Kanai, A

    1996-05-01

    We evaluated histochemically the characteristics of glycosaminoglycans and proteoglycans in the corneal subepithelial opacity after excimer laser keratectomy on rabbit corneas. We also performed the same evaluations on the cornea after mechanical keratectomy. Twenty days after the operations, the area immediately subjacent to the epithelium showed strong staining with toluidine blue, alcian blue, and colloidal iron. However, after treatment with chondroitinase ABC or chondroitinase AC, alcian blue staining in this area decreased dramatically. Antilarge proteoglycan antibody also reacted strongly in this area. Histochemical and immunohistochemical examination of the cornea where mechanical keratectomy was done showed basically similar findings with the cornea of excimer laser keratectomy. These results suggest that large-molecula proteoglycans with chondroitine sulfate side chains become localized in the subepithelial area after two different kinds of keratectomies. We presume from histochemical and immunohistochemical observations that the subepithelial opacity observed after excimer laser keratectomy is not a special reaction to excimer laser but simply a corneal scar formed after stromal resection.

  4. FTS Measurements of Submillimeter-Wave Atmospheric Opacity at Pampa la Bola

    Science.gov (United States)

    Matsuo, Hiroshi; Sakamoto, Akihiro; Matsushita, Satoki

    1998-06-01

    The first measurements of submillimeter-wave atmospheric opacity spectra at the Pampa la Bola site (Northern Chile, Atacama, 4800 m altitude) have been performed during the winter season using a Fourier transform spectrometer (FTS). Atmospheric emission spectra, as a function of airmass, were measured under various weather conditions. Atmospheric opacity was evaluated from sky temperature at the zenith as well as from tipping measurements, which are independent measures but give consistent results. Correlation diagrams between 220 GHz and 345 GHz, 410 GHz, 492 GHz, 675 GHz, 691 GHz, 809 GHz, 875 GHz are shown. Correlations between millimeter-wave and submillimeter-wave opacities get worse when 220 GHz opacity is larger than 0.1. Deviations from the opacity correlation at each frequency show good correlations themselves, but have different relative variations at each frequency. This indicates that atmospheric transparency cannot be characterized only by millimeter-wave opacity, but requires simultaneous opacity measurements at millimeter and submillimeter-wavelengths.

  5. Controlled opacity in a class of nonlinear dielectric media

    Science.gov (United States)

    Bittencourt, E.; Camargo, G. H. S.; De Lorenci, V. A.; Klippert, R.

    2017-03-01

    Motivated by new technologies for designing and tailoring metamaterials, we seek properties for certain classes of nonlinear optical materials that allow room for a reversibly controlled opacity-to-transparency phase transition through the application of external electromagnetic fields. We examine some mathematically simple models for the dielectric parameters of the medium and compute the relevant geometric quantities that describe the speed and polarization of light rays.

  6. The EOSTA model for opacities and EOS calculations

    Science.gov (United States)

    Barshalom, Avraham; Oreg, Joseph

    2007-11-01

    The EOSTA model developed recently combines the STA and INFERNO models to calculate opacities and EOS on the same footing. The quantum treatment of the plasma continuum and the inclusion of the resulted shape resonances yield a smooth behavior of the EOS and opacity global quantities vs density and temperature. We will describe the combined model and focus on its latest improvements. In particular we have extended the use of the special representation of the relativistic virial theorem to obtain an exact differential equation for the free energy. This equation, combined with a boundary condition at the zero pressure point, serves to advance the LDA EOS results significantly. The method focuses on applicability to high temperature and high density plasmas, warm dens matter etc. but applies at low temperatures as well treating fluids and even solids. Excellent agreement is obtained with experiments covering a wide range of density and temperature. The code is now used to create EOS and opacity databases for the use of hydro-dynamical simulations.

  7. Formation of Jupiter using opacities based on detailed grain physics

    CERN Document Server

    Movshovitz, Naor; Podolak, Morris; Lissauer, Jack J

    2010-01-01

    Numerical simulations, based on the core-nucleated accretion model, are presented for the formation of Jupiter at 5.2 AU in 3 primordial disks with three different assumed values of the surface density of solid particles. The grain opacities in the envelope of the protoplanet are computed using a detailed model that includes settling and coagulation of grains and that incorporates a recalculation of the grain size distribution at each point in time and space. We generally find lower opacities than the 2% of interstellar values used in previous calculations [Hubickyj, O., Bodenheimer, P., Lissauer, J. J., 2005. Icarus 179, 415--431; Lissauer, J. J., Hubickyj, O., D'Angelo, G., Bodenheimer, P., 2009. Icarus 199, 338-350]. These lower opacities result in more rapid heat loss from and more rapid contraction of the protoplanetary envelope. For a given surface density of solids, the new calculations result in a substantial speedup in formation time as compared with those previous calculations. Formation times are c...

  8. Lens opacities after repeated exposure to ultraviolet radiation.

    Science.gov (United States)

    Michael, R; Löfgren, S; Söderberg, P G

    1999-12-01

    To investigate the effect of the interval between two, near-threshold exposures to ultraviolet radiation (UVR) on cataract development. One eye of Sprague-Dawley rats was exposed twice to 4 kJ/m2 narrow band UVR (lambdaMAX=300 nm) for 15 min each. The interval between exposures was 0, 6, 24 or 48 h. One week after the first exposure both lenses were removed for photography and measurement of the intensity of forward light scattering to quantify lens opacities. All exposed lenses developed cataract. Forward light scattering was the same after double exposure with no interval or a 6 h interval. Forward light scattering after a 24 or 48 h interval was nearly twofold greater than that following no interval or a 6 h interval. The exposed lenses in all groups had mild anterior surface opacities and intense equatorial opacities as judged with a stereomicroscope. Two, near-threshold UVR exposures at 0 or a 6 h interval produce the same degree of lens opacification. When the second exposure follows 24 or 48 h after the first, lenticular damage increases. Repair processes between 24 and 48 h after exposure appear to be sensitive to UVR, and an additional exposure during this time may aggravate cataract development.

  9. Enforcement of opacity security properties for ship information system

    Directory of Open Access Journals (Sweden)

    Bowen Xing

    2016-09-01

    Full Text Available In this paper, we consider the cybersecurity issue of ship information system (SIS from a new perspective which is called opacity. For a SIS, its confidential information (named as “secret” may be leaked through the working behaviors of each Distributed Control Unit (DCU from an outside observer called an “intruder” which is able to determine ship's mission state by detecting the source of each data flow from the corresponding DCUs in SIS. Therefore we proposed a dual layer mechanism to enforce opacity by activating non-essential DCU during secret mission. This mechanism is calculated by two types of insertion functions: Safety-assured insertion function (fIS and Admissibility-assured insertion function (fIA. Due to different objectives, fIS is designed to confuse intruder by constructing a non-secret behaviors from a unsafe one, and the division of fIA is to polish the modified output behaviors back to normal. We define the property of “I2–Enforceability” that dual layer insertion functions has the ability to enforce opacity. By a given mission map of SIS and the marked secret missions, we propose an algorithm to select fIS and compute its matchable fIA and then the DCUs which should be activated to release non-essential data flow in each step is calculable.

  10. Effective Tree Scattering and Opacity at L-Band

    Science.gov (United States)

    Kurum, Mehmet; O'Neill, Peggy E.; Lang, Roger H.; Joseph, Alicia T.; Cosh, Michael H.; Jackson, Thomas J.

    2011-01-01

    This paper investigates vegetation effects at L-band by using a first-order radiative transfer (RT) model and truck-based microwave measurements over natural conifer stands to assess the applicability of the tau-omega) model over trees. The tau-omega model is a zero-order RT solution that accounts for vegetation effects with effective vegetation parameters (vegetation opacity and single-scattering albedo), which represent the canopy as a whole. This approach inherently ignores multiple-scattering effects and, therefore, has a limited validity depending on the level of scattering within the canopy. The fact that the scattering from large forest components such as branches and trunks is significant at L-band requires that zero-order vegetation parameters be evaluated (compared) along with their theoretical definitions to provide a better understanding of these parameters in the retrieval algorithms as applied to trees. This paper compares the effective vegetation opacities, computed from multi-angular pine tree brightness temperature data, against the results of two independent approaches that provide theoretical and measured optical depths. These two techniques are based on forward scattering theory and radar corner reflector measurements, respectively. The results indicate that the effective vegetation opacity values are smaller than but of similar magnitude to both radar and theoretical estimates. The effective opacity of the zero-order model is thus set equal to the theoretical opacity and an explicit expression for the effective albedo is then obtained from the zero- and first- order RT model comparison. The resultant albedo is found to have a similar magnitude as the effective albedo value obtained from brightness temperature measurements. However, it is less than half of that estimated using the theoretical calculations (0.5 - 0.6 for tree canopies at L-band). This lower observed albedo balances the scattering darkening effect of the large theoretical albedo

  11. Radiation attenuation and opacity in smoke and water sprays

    Science.gov (United States)

    Parent, Gilles; Boulet, Pascal; Morlon, Romain; Blanchard, Elizabeth

    2017-08-01

    Radiation attenuation through sprays, smoke and mixings of both media was studied in the infrared and in the visible range, by conducting real scale experiments in a corridor. The effect of water injection by a water mist nozzle and a sprinkler device was investigated. Radiation attenuation in the infrared range and opacity in the visible range were measured, by using a FTIR spectrometer and a dedicated opacimetry device especially designed for the present application. Experiments were done using either a blackbody source for attenuation characterization, or a heptane pool fire aimed at producing smoke for opacity measurements. For tests with smoke, the difficulties raised by the harsh environment involving a hot mixing of gas plus soot and vapor carrying water droplets were circumvented with an original device involving an optical fiber network. Mean infrared transmission was found equal to 12% for the water mist (with a 25 L/min water flowrate) and 37% for the sprinkler (with a 91 L/min water flowrate). Fitting the infrared transmission spectra with results obtained using a Monte Carlo simulation provided an estimation of the water volumetric fraction in the spray. It was shown that the better attenuation capability of the water mist is due to two factors: (1) a higher extinction coefficient of the water mist for a given water volumetric fraction due to the small size of the injected droplets and (2) a higher water volumetric fraction. Opacity measurements in the visible range yielded a measured extinction coefficient in good agreement with an estimation obtained with the Mie theory and the identified water volumetric fraction. Moreover, the water sprays (sprinkler or water mist) was seen to lead to a quick de-stratification of the smoke layer. When the spraying operation was stopped, the visibility re-increased in two main steps: a first step of fast increase and a second step of slow increase needing a few tens of seconds to get again a fully stratified smoke

  12. Sound speed and oscillation frequencies for solar models evolved with Los Alamos ATOMIC opacities

    CERN Document Server

    Guzik, Joyce A; Walczak, P; Wood, S R; Mussack, K; Farag, E

    2016-01-01

    Los Alamos National Laboratory has calculated a new generation of radiative opacities (OPLIB data using the ATOMIC code) for elements with atomic number Z=1-30 with improved physics input, updated atomic data, and finer temperature grid to replace the Los Alamos LEDCOP opacities released in the year 2000. We calculate the evolution of standard solar models including these new opacities, and compare with models evolved using the Lawrence Livermore National Laboratory OPAL (Iglesias and Rogers 1996) opacities. We use the solar abundance mixture of Asplund et al. (2009). The new Los Alamos ATOMIC opacities have steeper opacity derivatives than those of OPAL for temperatures and densities of the solar interior radiative zone. We compare the calculated nonadiabatic solar oscillation frequencies and solar interior sound speed to observed frequencies and helioseismic inferences. The calculated sound-speed profiles are similar for models evolved using either the updated Iben evolution code (see \\cite{Guzik2010}), or ...

  13. Prevalence of Lens Opacities in Adult Chinese Americans: The Chinese American Eye Study (CHES)

    OpenAIRE

    Varma, Rohit; Sun, Jie; Torres, Mina; Wu, Shuang; Hsu, Chunyi; Azen, Stanley Paul; McKean-Cowdin, Roberta; ,

    2016-01-01

    Purpose We determined the age- and sex-specific prevalence of posterior subcapsular (PSC), nuclear, cortical, and mixed lens opacities in a population-based sample of Chinese-American adults. Methods A population-based sample of Chinese-Americans 50 years and older, from 10 census tracts in Monterey Park, CA, USA, underwent a detailed interview and a comprehensive clinical examination that included assessment of different types of lens opacities by the slit-lamp–based Lens Opacities Classific...

  14. FTS measurements of submillimeter opacity and other site testing at Pampa la Bola

    Science.gov (United States)

    Matsushita, Satoki; Matsuo, Hiroshi; Sakamoto, Akihiro; Pardo, Juan R.

    2000-07-01

    We have carried out Fourier Transform Spectrometer (FTS) measurements of the millimeter and submillimeter-wave (150 - 1500 GHz or 2 mm - 200 micrometer) atmospheric opacity at Pampa la Bola, 4800 m above sea level in northern Chile on September 1997 and June 1998. One of the best transmission spectra show up to approximately 67% transmission at well- known submillimeter-wave windows. Supra-terahertz windows (located around 1035 GHz, 1350 GHz, and 1500 GHz) were identified in the same spectrum. The observed spectra can be well modeled by newly developed radiative-transfer calculations. Correlations between 220 GHz opacities and those of the center of submillimeter-wave windows or even those of the supra-terahertz windows are obtained using the entire data set. Good correlations were obtained except for the periods affected by the liquid water opacity component. We succeeded to separate the total opacity in two parts: the water vapor opacity and the liquid water opacity, using two frequencies, one in the millimeter domain and another one in the submillimeter. The separated water vapor opacity component shows good correlation with the 183 GHz pure water vapor line opacity which is also covered in the measured spectra, but the liquid water opacity component shows no correlation. The liquid water opacity component also shows no correlation with the phase fluctuation measured with the 11 GHz radio seeing monitor. Modeling of this component is currently under way. Combined with a statistical study of the 225 GHz opacity data of the Chajnantor site (approximately 7 km apart from Pampa la Bola), it is estimated that submillimeter-wave observations can be done with zenith opacity less than 1.0 (at the most transparent frequency in those windows) for about 50% of the winter season, assuming no presence of liquid water absorption.

  15. Detailed Opacity Comparison for an Improved Stellar Modeling of the Envelopes of Massive Stars

    Science.gov (United States)

    Turck-Chièze, S.; Le Pennec, M.; Ducret, J. E.; Colgan, J.; Kilcrease, D. P.; Fontes, C. J.; Magee, N.; Gilleron, F.; Pain, J. C.

    2016-06-01

    Seismic observations have led to doubts or ambiguities concerning the opacity calculations used in stellar physics. Here, we concentrate on the iron-group opacity peak, due to iron, nickel, and chromium, located around T = 200,000 K for densities from {10}-8 {to} {10}-4 {{g}} {{cm}}-3, which creates some convective layers in stellar radiative envelopes for masses between 3 and 18 {M}⊙ . These conditions were extensively studied in the 1980s. More recently, inconsistencies between OP and OPAL opacity calculations have complicated the interpretation of seismic observations as the iron-group opacity peak excites acoustic and gravity modes in SPB, β Cephei, and sdB stars. We investigate the reliability of the theoretical opacity calculations using the modern opacity codes ATOMIC and SCO-RCG. We show their temperature and density dependence for conditions that are achievable in the laboratory and equivalent to astrophysical conditions. We also compare new theoretical opacity spectra with OP spectra and quantify how different approximations impact the Rosseland mean calculations.This detailed study estimates new ATOMIC and SCO-RCG Rosseland mean values for astrophysical conditions which we compare to OP values. Some puzzling questions are still under investigation for iron, but we find a strong increase in the Rosseland mean nickel opacity of a factor between 2 and 6 compared to OP. This appears to be due to the use of extrapolated atomic data for the Ni opacity within the OP calculations. A study on chromium is also shown.

  16. Evidence for Environmental Changes in the Submillimeter Dust Opacity

    CERN Document Server

    Martin, Peter G; Bontemps, Sylvain; Miville-Deschênes, Marc-Antoine; Ade, Peter A R; Bock, James J; Chapin, Edward L; Devlin, Mark J; Dicker, Simon R; Griffin, Matthew; Gundersen, Joshua O; Halpern, Mark; Hargrave, Peter C; Hughes, David H; Klein, Jeff; Marsden, Gaelen; Mauskopf, Philip; Netterfield, Calvin B; Olmi, Luca; Patanchon, Guillaume; Rex, Marie; Scott, Douglas; Semisch, Christopher; Truch, Matthew D P; Tucker, Carole; Tucker, Gregory S; Viero, Marco P; Wiebe, Donald V

    2011-01-01

    The submillimeter opacity of dust in the diffuse Galactic interstellar medium (ISM) has been quantified using a pixel-by-pixel correlation of images of continuum emission with a proxy for column density. We used three BLAST bands at 250, 350, and 500 \\mu m and one IRAS at 100 \\mu m. The proxy is the near-infrared color excess, E(J-Ks), obtained from 2MASS. Based on observations of stars, we show how well this color excess is correlated with the total hydrogen column density for regions of moderate extinction. The ratio of emission to column density, the emissivity, is then known from the correlations, as a function of frequency. The spectral distribution of this emissivity can be fit by a modified blackbody, whence the characteristic dust temperature T and the desired opacity \\sigma_e(1200) at 1200 GHz can be obtained. We have analyzed 14 regions near the Galactic plane toward the Vela molecular cloud, mostly selected to avoid regions of high column density (N_H > 10^{22} cm^-2) and small enough to ensure a u...

  17. Iron Opacity Platform Performance Characterization at the National Ignition Facility

    Science.gov (United States)

    Opachich, Y. P.; Ross, P. W.; Heeter, R. F.; Barrios, M. A.; Liedahl, D. A.; May, M. J.; Schneider, M. B.; Craxton, R. S.; Garcia, E. M.; McKenty, P. W.; Zhang, R.; Weaver, J. L.; Flippo, K. A.; Kline, J. L.; Perry, T. S.; Los Alamos National Laboratory Collaboration; Naval Research Laboratory Collaboration; University of Rochester LaboratoryLaser Energetics Collaboration; Lawrence Livermore National Lab Collaboration; National Security Technologies, LLC Collaboration

    2016-10-01

    A high temperature opacity platform has been fielded at the National Ignition Facility (NIF). The platform will be used to study opacity in iron at a temperature of 160 eV. The platform uses a 6 mm diameter hohlraum driven by 128 laser beams with 530 kJ of energy in a 3 ns pulse to heat an iron sample. Absorption spectra of the heated sample are generated with a broadband pulsed X-ray backlighter produced by imploding a vacuum-filled CH shell. The shell is 2 mm in diameter and 20 microns thick, driven by 64 beams with 250 kJ in a 2.5 ns pulse. The hohlraum and backlighter performance have both been investigated recently and will be discussed in this presentation. This work was performed by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy. DOE/NV/25946-2892.

  18. Iron Opacity and the Pulsar of SN 1987A

    CERN Document Server

    Fryer, C L; Pinto, P A

    1999-01-01

    Neutron stars formed in Type II supernovae are likely to be initially obscured by late-time fallback. Although much of the late-time fallback is quickly accreted via neutrino cooling, some material remains on the neutron star, forming an atmosphere which slowly accretes through photon emission. In this paper, we derive structure equations of the fallback atmosphere and present results of one-dimensional simulations of that fallback. The atmosphere remaining after neutrino cooling becomes unimportant (less than the Compton Eddington limit) is only a fraction of the total mass accreted (10^-8 of the accreted mass or 10^-9 solar masses.) Recombined iron dominates the opacity in the outer regions leading to an opacity 1000-10,000 times higher than that of electron scattering alone. The resultant photon emission of the remnant atmosphere is limited to 1/1000th the Compton Eddington Luminosity. The late-time evolution of this system leads to the formation of a photon-driven wind from the accretion of the inner port...

  19. New dust opacity mapping from Viking Infrared Thermal Mapper data

    Science.gov (United States)

    Martin, Terry Z.; Richardson, Mark I.

    1993-01-01

    Global dust opacity mapping for Mars has been carried forward using the approach described by Martin (1986) for Viking IR Thermal Mapper data. New maps are presented for the period from the beginning of Viking observations, until Ls 210 deg in 1979 (1.36 Mars years). This range includes the second and more extensive planet-encircling dust storm observed by Viking, known as storm 1977b. Improvements in approach result in greater time resolution and smaller noise than in the earlier work. A strong local storm event filled the Hellas basin at Ls 170 deg, prior to the 1977a storm. Dust is retained in equatorial regions following the 1977b storm far longer than in mid-latitudes. Minor dust events appear to raise the opacity in northern high latitudes during northern spring. Additional mapping with high time resolution has been done for the periods of time near the major storm origins in order to search for clues to the mechanism of storm initiation. The first evidence of the start of the 1977b storm is pushed back to Ls 274.2 deg, preceding signs of the storm in images by about 15 hours.

  20. Galactic cold cores VI. Dust opacity spectral index

    CERN Document Server

    Juvela, M; Doi, Y; Hughes, A; Lefevre, C; Marshall, D J; Meny, C; Montillaud, J; Pagani, L; Paradis, D; Ristorcelli, I; Malinen, J; Montier, L A; Paladini, R; Pelkonen, V -M; Rivera-Ingraham, A

    2015-01-01

    The Galactic Cold Cores project has made Herschel observations of 116 fields where the Planck survey has found signs of cold dust emission. The fields contain sources in different environments and different phases of star formation. The dust opacity spectral index beta and the dust colour temperature T are derived using Herschel and Planck data. The relation between beta and T is examined for the whole sample and inside individual fields. Based on IRAS and Planck data, the fields are characterised by a median colour temperature of 16.1 K and a median opacity spectral index of beta=1.84. We observe a clear T-beta anti-correlation. In Herschel observations, constrained at lower resolution by Planck data, the variations follow the column density structure and beta(FIR) can rise to ~2.2 in individual clumps. The Planck 217 GHz band shows a systematic excess that is consistent with a general flattening of the dust emission spectrum at millimetre wavelengths. When fitted separately below and above 700 um, the media...

  1. Grain opacity and the bulk composition of extrasolar planets. II. An analytical model for the grain opacity in protoplanetary atmospheres

    CERN Document Server

    Mordasini, C

    2014-01-01

    Context. We investigate the grain opacity k_gr in the atmosphere of protoplanets. This is important for the planetary mass-radius relation since k_gr affects the H/He envelope mass of low-mass planets and the critical core mass of giant planets. Aims. The goal of this study is to derive an analytical model for k_gr. Methods. Our model is based on the comparison of the timescales of microphysical processes like grain settling in the Stokes and Epstein regime, growth by Brownian motion coagulation and differential settling, grain evaporation, and grain advection due to envelope contraction. With these timescales we derive the grain size, abundance, and opacity. Results. We find that the main growth process is differential settling. In this regime, k_gr has a simple functional form and is given as 27 Q/8 H rho in the Epstein regime and as 2 Q/H rho for Stokes drag. Grain dynamics lead to a typical radial structure of k_gr with high ISM-like values in the top layers but a strong decrease in the deeper parts where...

  2. 77 FR 13977 - Quality Assurance Requirements for Continuous Opacity Monitoring Systems at Stationary Sources

    Science.gov (United States)

    2012-03-08

    ... AGENCY 40 CFR Part 60 RIN 2060-AH23 Quality Assurance Requirements for Continuous Opacity Monitoring... final rule titled, ``Quality Assurance Requirements for Continuous Opacity Monitoring Systems at... electronically in www.regulations.gov or in hard copy at the Procedure 3--Quality Assurance Requirements for...

  3. 77 FR 8160 - Quality Assurance Requirements for Continuous Opacity Monitoring Systems at Stationary Sources

    Science.gov (United States)

    2012-02-14

    ... AGENCY 40 CFR Part 60 RIN 2060-AH23 Quality Assurance Requirements for Continuous Opacity Monitoring...--Quality Assurance Requirements for Continuous Opacity Monitoring Systems at Stationary Sources Docket, EPA.... Rules establishing quality assurance requirements impose no costs independent from national emission...

  4. 77 FR 18709 - Quality Assurance Requirements for Continuous Opacity Monitoring Systems at Stationary Sources

    Science.gov (United States)

    2012-03-28

    ... AGENCY 40 CFR Part 60 RIN 2060-AH23 Quality Assurance Requirements for Continuous Opacity Monitoring... final rule. SUMMARY: The EPA published a direct final rule titled ``Quality Assurance Requirements for....regulations.gov or in hard copy at the Procedure 3--Quality Assurance Requirements for Continuous Opacity...

  5. 40 CFR Figure 1 to Subpart Qqq of... - Data Summary Sheet for Determination of Average Opacity

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Data Summary Sheet for Determination of.... 63, Subpt. QQQ, Fig. 1 Figure 1 to Subpart QQQ of Part 63—Data Summary Sheet for Determination of Average Opacity Clock time Number of converters blowing Converter aisle activity Average opacity for...

  6. Fine-Tuning Two-Particle Interferometry; 2, Opacity Effects

    CERN Document Server

    Tomasik, Boris; Tomasik, Boris; Heinz, Ulrich

    1998-01-01

    We present a model study of single-particle spectra and two-particle Bose-Einstein correlations for opaque sources. We study the transverse mass dependence of the correlation radii R_\\perp, R_\\parallel and R_0 in the YKP parametrization and find a strong sensitivity of the temporal radius parameter R_0^2 to the source opacity. A simple comparison with the published data from 158 A GeV/c Pb+Pb collisions at CERN indicates that the pion source created in these collisions emits particles from the whole reaction volume and is not opaque. For opaque sources we find certain regions of inapplicability of the YKP parametrization which can be avoided by a slightly different parametrization for the correlator. The physical meaning of the modified parameters is briefly discussed.

  7. Galactic cold cores. VI. Dust opacity spectral index

    Science.gov (United States)

    Juvela, M.; Demyk, K.; Doi, Y.; Hughes, A.; Lefèvre, C.; Marshall, D. J.; Meny, C.; Montillaud, J.; Pagani, L.; Paradis, D.; Ristorcelli, I.; Malinen, J.; Montier, L. A.; Paladini, R.; Pelkonen, V.-M.; Rivera-Ingraham, A.

    2015-12-01

    Context. The Galactic Cold Cores project has carried out Herschel photometric observations of 116 fields where the Planck survey has found signs of cold dust emission. The fields contain sources in different environments and different phases of star formation. Previous studies have revealed variations in their dust submillimetre opacity. Aims: The aim is to measure the value of dust opacity spectral index and to understand its variations spatially and with respect to other parameters, such as temperature, column density, and Galactic location. Methods: The dust opacity spectral index β and the dust colour temperature T are derived using Herschel and Planck data. The relation between β and T is examined for the whole sample and inside individual fields. Results: Based on IRAS and Planck data, the fields are characterised by a median colour temperature of 16.1 K and a median opacity spectral index of β = 1.84. The values are not correlated with Galactic longitude. We observe a clear T-β anti-correlation. In Herschel observations, constrained at lower resolution by Planck data, the variations follow the column density structure and βFIR can rise to ~2.2 in individual clumps. The highest values are found in starless clumps. The Planck 217 GHz band shows a systematic excess that is not restricted to cold clumps and is thus consistent with a general flattening of the dust emission spectrum at millimetre wavelengths. When fitted separately below and above 700 μm, the median spectral index values are βFIR ~ 1.91 and β(mm) ~ 1.66. Conclusions: The spectral index changes as a function of column density and wavelength. The comparison of different data sets and the examination of possible error sources show that our results are robust. However, β variations are partly masked by temperature gradients and the changes in the intrinsic grain properties may be even greater. Planck http://www.esa.int/Planck is a project of the European Space Agency - ESA - with instruments

  8. Opacity measurements in shock-generated argon plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, D.

    1993-07-01

    Dense plasmas having uniform and constant density and temperature are generated by passage of a planar shock wave through gas. The opacity of the plasma is accurately measured versus wavelength by recording the risetime of emitted light. This technique is applicable to a wide variety of species and plasma conditions. Initial experiments in argon have produced plasmas with 2 eV temperatures, 0.004--0.04 g/cm{sup 3} densities, and coupling parameters {Gamma} {approximately}0.3--0.7. Measurements in visible light are compared with calculations using the HOPE code. An interesting peak in the capacity at 400 nm is observed for the first time and is identified with the 4s-5p transition in excited neutral argon atoms.

  9. The hybrid opacity code SCO-RCG: recent developments

    CERN Document Server

    Pain, Jean-Christophe; Porcherot, Quentin; Blenski, Thomas

    2013-01-01

    Absorption and emission spectra of multicharged-ion plasmas contain a huge number of electron configurations and electric-dipolar lines, which can be handled by global methods. However, some transition arrays consist only of a small bunch of lines. For that reason, we developed the hybrid opacity code SCO-RCG combining the (statistical) super-transition-array method and the (detailed) fine-structure calculation (requiring the diagonalization of the Hamiltonian matrix) of atomic structure. In order to decide whether a detailed treatment of lines is necessary and to determine the validity of statistical methods, the code involves criteria taking into account coalescence of lines and porosity (localized absence of lines) in transition arrays. Data required for the calculation of detailed transition arrays (Slater, spin-orbit and dipolar integrals) are provided by the super-configuration code SCO, which takes into account plasma screening effects on wavefunctions. Then, level energies and lines are calculated by ...

  10. Rosseland Mean Opacity of a High-Z Mixture Plasma

    Institute of Scientific and Technical Information of China (English)

    杨家敏; 许琰; 丁耀南; 丁永坤; 江少恩; 郑志坚; 缪文勇

    2003-01-01

    An eight-beam 0.351-μm laser with pulse duration of about 1.0ns and energy of 260 J per beam was injected into a cylindrical cavity to generate intense x-ray radiation on the Shengguang Ⅱ high power laser facility. A mixture foil of gold and gadolinium and a gold foil were attached on portion of a diagnostic hole in the mid-plane of the cavity and ablated by the intense x-ray radiation. The propagating time of the radiation heat wave in the mixture and the pure gold foil were measured with soft-x-ray spectrometer and by adopting space- and timeresolved measurement technology, respectively. The results show that the mixture of gold and gadolinium has higher Rosseland mean opacity than the gold sample in our experiment.

  11. Iron Opacity Bump Changes the Stability and Structure of Accretion Disks in Active Galactic Nuclei

    CERN Document Server

    Jiang, Yan-Fei; Stone, James

    2016-01-01

    Accretion disks around supermassive black holes have regions where the Rosseland mean opacity can be much larger than the electron scattering opacity primarily due to the large number of bound-bound transitions in iron. We study the effects of this iron opacity "bump" on the thermal stability and vertical structure of radiation pressure dominated accretion disks, utilizing three dimensional radiation magneto-hydrodynamic simulations in the local shearing box approximation. The simulations self-consistently calculate the heating due to MHD turbulence caused by magneto-rotational instability and radiative cooling by using the radiative transfer module based on a variable Eddington tensor in Athena. For a $5\\times 10^8$ solar mass black hole with $\\sim 3\\%$ of the Eddington luminosity, a model including the iron opacity bump maintains its structure for more than $10$ thermal times without showing significant signs of thermal runaway. In contrast, if only electron scattering and free-free opacity are included as ...

  12. The statistical properties of stars and their dependence on metallicity: the effects of opacity

    CERN Document Server

    Bate, Matthew R

    2014-01-01

    We report the statistical properties of stars and brown dwarfs obtained from four radiation hydrodynamical simulations of star cluster formation that resolve masses down to the opacity limit for fragmentation. The calculations are identical except for their dust and gas opacities. Assuming dust opacity is proportional to metallicity, the calculations span a range of metallicities from 1/100 to 3 times solar, although we emphasise that changing the metallicity has other thermodynamic effects that the calculations do not capture (e.g. on the thermal coupling between gas and dust). All four calculations produce stellar populations whose statistical properties are difficult to distinguish from observed stellar systems, and we find no significant dependence of stellar properties on opacity. The mass functions and properties of multiple stellar systems are consistent with each other. However, we find protostellar mergers are more common with lower opacities. Combining the results from the three calculations with th...

  13. OPACITY MEASUREMENT AND THEORETICAL INVESTIGATION OF HOT SILICON PLASMA

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Gang; Yang, Jiamin; Zhang, Jiyan; Hu, Zhimin; Zhao, Yang; Qing, Bo; Yang, Guohong; Wei, Minxi; Yi, Rongqing; Song, Tianming; Li, Hang; Yuan, Zheng; Lv, Min [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Meng, Xujun; Xu, Yan; Wu, Zeqing; Yan, Jun, E-mail: zhangjiyanzjy@sina.com, E-mail: zhimin.hu@yahoo.com [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)

    2016-01-01

    We report on opacity measurements of a silicon (Si) plasma at a temperature of (72 ± 5) eV and a density of (6.0 ± 1.2) mg cm{sup −3} in the photon energy range of 1790–1880 eV. A 23 μg cm{sup −2} Si foil tamped by 50 μg cm{sup −2} CH layers on each side was heated to a hot-dense plasma state by X-ray radiation emitted from a D-shaped gold cavity that was irradiated by intense lasers. Absorption lines of 1s − 2p transitions of Si xiii to Si ix ions have been measured using point-projection spectroscopy. The transmission spectrum of the silicon plasma was determined by comparing the light passing through the plasma to the light from the same shot passing by the plasma. The density of the Si plasma was determined experimentally by side-on radiography and the temperature was estimated from the radiation flux data. Radiative hydrodynamic simulations were performed to obtain the temporal evolutions of the density and temperature of the Si plasma. The experimentally obtained transmission spectra of the Si sample plasma have been reproduced using a detailed term account model with the local thermodynamic equilibrium approximation. The energy levels, oscillator strengths and photoionization cross-sections used in the calculation were generated by the flexible atomic code. The experimental transmission spectrum was compared with the theoretical calculation and good agreement was found. The present experimental spectrum and theoretical calculation were also compared with the new opacities available in the Los Alamos OPLIB database.

  14. Measurements of the 492 GHz Atmospheric Opacity at Pampa la Bola and Rio Frio in Northern Chile

    Science.gov (United States)

    Hirota, Tomoya; Yamamoto, Satoshi; Sekimoto, Yutaro; Kohno, Kotaro; Nakai, Naomasa; Kawabe, Ryohei

    1998-02-01

    We have developed a transportable 492 GHz tipping radiometer to measure the atmospheric opacity at potential sites for future ground-based astronomical observations in the submillimeter-wave band. With this radiometer, we measured the atmospheric opacity at two sites in northern Chile, Pampa la Bola (elevation 4800 m) and Rio Frio (elevation 4100 m), each for a few days. The 492 GHz opacity mostly ranged from 0.5 to 1.5 during the measurements. The 220 GHz opacity was also measured at the same time. The 492 GHz opacity correlates well with the 220 GHz opacity, the ratio between the 492 and 220 GHz opacities being 21.2 +/- 0.4. This result supports the standard atmospheric model, and can be used to evaluate the observable fraction of time for submillimeter-wave observations on the basis of the long-term 220 GHz opacity data. } %

  15. 3.5 Year Monitoring of 225 GHz Opacity at the Summit of Greenland

    Science.gov (United States)

    Matsushita, Satoki; Asada, Keiichi; Martin-Cocher, Pierre L.; Chen, Ming-Tang; Ho, Paul T. P.; Inoue, Makoto; Koch, Patrick M.; Paine, Scott N.; Turner, David D.

    2017-02-01

    We present the 3.5 years monitoring results of 225 GHz opacity at the summit of the Greenland ice sheet (Greenland Summit Camp) at an altitude of 3200 m using a tipping radiometer. We chose this site as our submillimeter telescope (Greenland Telescope) site, because conditions are expected to have low submillimeter opacity and because its location offers favorable baselines to existing submillimeter telescopes for global-scale Very Long Baseline Interferometry. The site shows a clear seasonal variation with the average opacity lower by a factor of two during winter. The 25%, 50%, and 75% quartiles of the 225 GHz opacity during the winter months of November through April are 0.046, 0.060, and 0.080, respectively. For the winter quartiles of 25% and 50%, the Greenland site is about 10%-30% worse than the Atacama Large Millimeter/submillimeter Array (ALMA) or the South Pole sites. Estimated atmospheric transmission spectra in winter season are similar to the ALMA site at lower frequencies (\\lt 450 GHz), which are transparent enough to perform astronomical observations almost all of the winter time with opacities \\lt 0.5, but 10%-25% higher opacities at higher frequencies (\\gt 450 GHz) than those at the ALMA site. This is due to the lower altitude of the Greenland site and the resulting higher line wing opacity from pressure-broadened saturated water lines in addition to higher dry air continuum absorption at higher frequencies. Nevertheless, half of the winter time at the Greenland Summit Camp can be used for astronomical observations at frequencies between 450 GHz and 1000 GHz with opacities \\lt 1.2, and 10% of the time show \\gt 10 % transmittance in the THz (1035 GHz, 1350 GHz, and 1500 GHz) windows. Summer season is good for observations at frequencies lower than 380 GHz. One major advantage of the Greenland Summit Camp site in winter is that there is no diurnal variation due to the polar night condition, and therefore the durations of low-opacity conditions

  16. The impact of enhanced iron opacity on massive star pulsations: updated instability strips

    Science.gov (United States)

    Moravveji, Ehsan

    2016-01-01

    Recently, Bailey et al. made a direct measurement of the iron opacity at the physical conditions of the solar tachocline. They found that the wavelength-integrated iron opacity is roughly 75 per cent higher than what the Opacity Project (OP) and OPAL models predict. Here, we compute new opacity tables with enhanced iron and nickel contributions to the Rosseland mean opacity by 75 per cent each, and compute three dense MESA grids of evolutionary models for Galactic O- and B-type stars covering from 2.5 to 25 M⊙ from zero-age main sequence (ZAMS) until Teff = 10 000 K after the core hydrogen exhaustion. We carry out non-adiabatic mode stability analysis with GYRE, and update the extension of the instability strips of heat-driven p- and g-mode pulsators, and the hybrid slowly pulsating B (SPB) - β Cep stars. We compare the position of two confirmed late O-type β Cep and eight confirmed hybrid B-type pulsators with the new instability domains, and justify that ˜75 per cent enhancement, only in iron opacity, is sufficient to consistently reproduce the observed position of these stars on the log Teff versus log g plane. We propose that this improvement in opacities be incorporated in the input physics of new stellar models.

  17. Detailed investigations on radiative opacity and emissivity of tin plasmas in the extreme-ultraviolet region.

    Science.gov (United States)

    Zeng, Jiaolong; Gao, Cheng; Yuan, Jianmin

    2010-08-01

    Radiative opacity and emissivity of tin plasmas at average ionization degree of about 10 was investigated in detail by using a fully relativistic detailed level accounting approach, in which main physical effects on the opacity were carefully taken into account. Among these physical effects, configuration interaction, in particular core-valence electron correlations, plays an important role on the determination of accurate atomic data required in the calculation of opacity. It results in a strong narrowing of lines from all transition arrays and strong absorption is located in a narrow wavelength region of 12.5-14 nm for Sn plasmas. Using a complete accurate atomic data, we investigated the opacity of Sn plasmas at a variety of physical condition. Among the respective ions of Xe6+-Xe15+ , Xe10+ has the largest absorption cross section at 13.5 nm, while the favorable physical condition for maximal absorption at 13.5 nm do not mean that Xe10+ has the largest fraction. Comparison with other theoretical results showed that a complete set of consistent accurate atomic data, which lacks very much, is essential to predict accurate opacity. Our atomic model is useful and can be applied to interpret opacity experiments. Further benchmark experiments are urgently needed to clarify the physical effects on the opacity of Sn plasmas.

  18. Using xRage to Model Heat Flow for Experiments to Measure Opacities in HED Plasmas

    Science.gov (United States)

    Elgin, L.; Vandervort, R.; Keiter, P.; Drake, R. P.; Mussack, K.; Orban, C.

    2015-11-01

    We are developing a NIF proposal to measure opacities of C, N and O at temperatures and densities relevant to the base of the solar convection zone. Our proposed experiments would provide the first opacity measurements for these elements within this HED regime. A critical feature of our experimental platform is a super-sonic radiation front propagating within the targets. Under these conditions, density remains constant across the radiation front for a couple nanoseconds, enabling a window during which the opacities of the hot and cold target may be measured simultaneously. Afterwards, hydrodynamic effects create temperature and density gradients, which would obfuscate analysis of opacity data. We are using xRage to simulate heat flow within our targets in order to estimate the time scale over which temperature and density gradients evolve. These simulations will better inform our target design and diagnostic requirements. If successful, our experiments could yield the data necessary to validate existing opacity models or provide physical insights to inform the development of new opacity models. Accurate opacity models are essential to the understanding of radiation transport within HED systems, with applications ranging from astrophysics to ICF. U.S. Department of Energy, through the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, grant #DE-NA0001840. Los Alamos National Laboratory, LA-UR-15-25490.

  19. Systematic measurements of opacity dependence on temperature, density, and atomic number at stellar interior conditions

    Science.gov (United States)

    Bailey, James; Nagayama, T.; Loisel, G. P.; Rochau, G. A.; Blancard, C.; Colgan, J.; Cosse, Ph.; Faussurier, G.; Fontes, C. J.; Golovkin, I.; Hansen, S. B.; Iglesias, C. A.; Kilcrease, D. P.; Macfarlane, J. J.; Mancini, R. C.; Nahar, S. N.; Orban, C.; Pradhan, A. K.; Sherrill, M.; Wilson, B. G.; Pain, J. C.; Gilleron, F.

    2016-10-01

    Model predictions for iron opacity are notably different from measurements performed at conditions similar to the boundary between the solar radiation and convection zone. New measurements at the Sandia Z facility with chromium, iron, and nickel are providing a systematic study of how opacity changes with temperature, density, and atomic number. These measurements help further evaluate possibilities for experiment errors and help constrain hypotheses for opacity model refinements. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

  20. Theoretical Study of the Opacity for Mixture Materials at High Temperatures

    Institute of Scientific and Technical Information of China (English)

    颜君; 吴泽清; 逄锦桥; 邱玉波

    2002-01-01

    Using a detailed configuration accounting model with term structures treated by the unresolved transition array model, we have extensively investigated the opacities of mixt ure materials. For plasmas at the temperat ure of 250eV and density of 1 g/cm3, our calculated Rosseland mean opacities are in good agreement with other theoretical results. A high increase in the Rosseland mean opacity to 2944 cm2/g is achieved for a multi-element mixture compared to the value of 1729 cm2/g for pure gold. Various mixtures at other plasma conditions are also studied.

  1. Mixed quotation: The grammar of apparently transparent opacity

    Directory of Open Access Journals (Sweden)

    Emar Maier

    2014-05-01

    Full Text Available The phenomenon of mixed quotation exhibits clear signs of both the apparent transparency of compositional language use and the opacity of pure quotation. I argue that the interpretation of a mixed quotation in- volves the resolution of a metalinguistic presupposition. The leading idea behind my proposal is that a mixed-quoted expression, say, “has an anomalous feature”, means what x referred to with the words ‘has an anomalous feature’. To understand how this solves the paradox, I set up a precise grammatical framework, explicitly connecting various levels of linguistic analysis: phonological forms, categorial syntax, and a dynamic picture of the semantics–pragmatics interface. In this framework I formalize and evaluate a presuppositional account of mixed quotation. Finally, I address the phenomenon of unquotation and argue that it is an essential ingredient for an elegant and empirically adequate analysis of mixed quotation in natural language. http://dx.doi.org/10.3765/sp.7.7 BibTeX info

  2. Large enhancement in high-energy photoionization of Fe XVII and missing continuum plasma opacity

    CERN Document Server

    Nahar, Sultana N

    2016-01-01

    Aimed at solving the outstanding problem of solar opacity, and radiation transport plasma models in general, we report substantial photoabsorption in the high-energy regime due to atomic core photo-excitations not heretofore considered. In extensive R-Matrix calculations of unprecedented complexity for an important iron ion Fe xvii (Fe$^{16+}$), with a wave function expansion of 99 Fe xviii (Fe$^{17+}$) LS core states from $n \\leq 4$ complexes (equivalent to 218 fine structure levels), we find: i) up to orders of magnitude enhancement in background photoionization cross sections, in addition to strongly peaked photo-excitation-of-core resonances not considered in current opacity models, and ii) demonstrate convergence with respect to successive core excitations. The resulting increase in the monochromatic continuum, and 35% in the Rosseland Mean Opacity, are compared with the "higher-than-predicted" iron opacity measured at the Sandia Z-pinch fusion device at solar interior conditions.

  3. Radiative opacity of plasmas studied by detailed term (level) accounting approaches

    Institute of Scientific and Technical Information of China (English)

    ZENG Jiao-long; JIN Feng-tao; YUAN Jian-min

    2006-01-01

    Detailed term and level accounting (DTA and DLA) schemes have been developed to calculate the spectrally resolved and Rosseland and Planck mean opacities of plasmas in local thermodynamic equilibrium.Various physical effects,such as configuration interaction effect (including core-valence electron correlations effect and relativistic effect),detailed line width effect (including the line saturation effect),etc.,on the opacity of plasmas have been investigated in detail.Some of these physical effects are less capable or even impossible to be taken into account by statistical models such as unresolved transition arrays,super-transitionarray or average atom models.Our detailed model can obtain accurate opacity of plasmas.Using this model,we have systematically investigated the radiative opacities of low,medium and high-Z plasmas under different conditions of temperature and density.For example,for aluminum plasma,in the X-ray region,we demonstrated the effects of autoionization resonance broadening on the opacity for the first time.Furthermore,the relativistic effects play an important role on the opacity as well.Our results are in good agreement with other theoretical ones although better agreement can be obtained after the effects of autoionization resonance broadening and relativity have been considered.Our results also show that the modelling of the opacity is very complicated,since too many physical effects influence the accuracy of opacity.``For medium and high-Z plasmas,however,there are systematic discrepancies unexplained so far between the theoretical and experimental opacities.Here,the theoretical opacities are mainly obtained by statistical models.To clarify the discrepaneies,efforts from both sides are needed.From the viewpoint of theory,however,a DLA method,in which various physical effects can be taken into account,should be useful in resolving the difference.Taking gold plasma as an example,we studied in detail the effects of core-valence electron

  4. Computational Design of Short Pulse Laser Driven Iron Opacity Measurements at Stellar-Relevant Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Madison E. [Univ. of Florida, Gainesville, FL (United States)

    2017-05-20

    Opacity is a critical parameter in the simulation of radiation transport in systems such as inertial con nement fusion capsules and stars. The resolution of current disagreements between solar models and helioseismological observations would bene t from experimental validation of theoretical opacity models. Overall, short pulse laser heated iron experiments reaching stellar-relevant conditions have been designed with consideration of minimizing tamper emission and optical depth effects while meeting plasma condition and x-ray emission goals.

  5. Purification and partial characterization of the opacity-associated proteins of Neisseria gonorrhoeae

    OpenAIRE

    1984-01-01

    Gonococci, grown on agar, frequently give rise to opaque colonies. This opacity phenotype is associated with the presence of one or more outer membrane proteins of approximately 28,000 mol weight. These proteins are included within a class of proteins named proteins II. A method is described to isolate and purify the opacity-associated proteins from Neisseria gonorrhoeae. This method uses high concentrations of calcium and a zwitterionic detergent at pH 4.0. Under these conditions proteins II...

  6. OPAC AS DOCUMENT RETRIEVAL TOOL: A CASE STUDY OF THE UNIVERSITY OF KASHMIR

    Directory of Open Access Journals (Sweden)

    Uzma Qadri, Research Scholar,

    2012-01-01

    Full Text Available The application of the information and communication technology has changed the entireenvironment of the library including cataloguing. Today, a number of libraries are providingOnline Public Access Cataloguing service to their users to find out their documents and theAllama Iqbal Library, University of Kashmir isn’t an exception. The main purpose of the study isto measure the faculty wise use of OPAC by the P G students of University of Kashmir. Toaccomplish the purpose of the study, survey method was adopted and questionnaire was used asdata collection tool. The questionnaire was distributed among 260 students selecting 10 students from each department in the month of May 2012. However, only 241 students returned the filled questionnaire with response rate of 92.69 %. The results revealed that 60% of the respondents use OPAC to search the library collection whereas 40% don’t use it at all. The students who use OPAC cite many features like time saving; fast response; remote access etc. and the students don’t use OPAC mostly due to awareness problem. This study found that most of the student learn to operate OPAC from themselves followed by friends/colleagues and library staff. The students search the library material mostly through subject, author and title approach. At the end, the fruitful suggestions are provided for greater use of OPAC.

  7. How the machine ‘thinks’: Understanding opacity in machine learning algorithms

    Directory of Open Access Journals (Sweden)

    Jenna Burrell

    2016-01-01

    Full Text Available This article considers the issue of opacity as a problem for socially consequential mechanisms of classification and ranking, such as spam filters, credit card fraud detection, search engines, news trends, market segmentation and advertising, insurance or loan qualification, and credit scoring. These mechanisms of classification all frequently rely on computational algorithms, and in many cases on machine learning algorithms to do this work. In this article, I draw a distinction between three forms of opacity: (1 opacity as intentional corporate or state secrecy, (2 opacity as technical illiteracy, and (3 an opacity that arises from the characteristics of machine learning algorithms and the scale required to apply them usefully. The analysis in this article gets inside the algorithms themselves. I cite existing literatures in computer science, known industry practices (as they are publicly presented, and do some testing and manipulation of code as a form of lightweight code audit. I argue that recognizing the distinct forms of opacity that may be coming into play in a given application is a key to determining which of a variety of technical and non-technical solutions could help to prevent harm.

  8. Coagulation and Fragmentation in molecular clouds. II. The opacity of the dust aggregate size distribution

    CERN Document Server

    Ormel, C W; Tielens, A G G M; Dominik, C; Paszun, D

    2011-01-01

    The dust size distribution in molecular clouds can be strongly affected by ice-mantle formation and (subsequent) grain coagulation. Following previous work where the dust size distribution has been calculated from a state-of-the art collision model for dust aggregates that involves both coagulation and fragmentation (Paper I), the corresponding opacities are presented in this study. The opacities are calculated by applying the effective medium theory assuming that the dust aggregates are a mix of 0.1{\\mu}m silicate and graphite grains and vacuum. In particular, we explore how the coagulation affects the near-IR opacities and the opacity in the 9.7{\\mu}m silicate feature. We find that as dust aggregates grow to {\\mu}m-sizes both the near-IR color excess and the opacity in the 9.7 {\\mu}m feature increases. Despite their coagulation, porous aggregates help to prolong the presence of the 9.7{\\mu}m feature. We find that the ratio between the opacity in the silicate feature and the near-IR color excess becomes lowe...

  9. How the machine ‘thinks’: Understanding opacity in machine learning algorithms

    Directory of Open Access Journals (Sweden)

    Jenna Burrell

    2016-01-01

    Full Text Available This article considers the issue of opacity as a problem for socially consequential mechanisms of classification and ranking, such as spam filters, credit card fraud detection, search engines, news trends, market segmentation and advertising, insurance or loan qualification, and credit scoring. These mechanisms of classification all frequently rely on computational algorithms, and in many cases on machine learning algorithms to do this work. In this article, I draw a distinction between three forms of opacity: (1 opacity as intentional corporate or state secrecy, (2 opacity as technical illiteracy, and (3 an opacity that arises from the characteristics of machine learning algorithms and the scale required to apply them usefully. The analysis in this article gets inside the algorithms themselves. I cite existing literatures in computer science, known industry practices (as they are publicly presented, and do some testing and manipulation of code as a form of lightweight code audit. I argue that recognizing the distinct forms of opacity that may be coming into play in a given application is a key to determining which of a variety of technical and non-technical solutions could help to prevent harm.

  10. Functional characterization of antibodies against Neisseria gonorrhoeae opacity protein loops.

    Directory of Open Access Journals (Sweden)

    Jessica G Cole

    Full Text Available BACKGROUND: The development of a gonorrhea vaccine is challenged by the lack of correlates of protection. The antigenically variable neisserial opacity (Opa proteins are expressed during infection and have a semivariable (SV and highly conserved (4L loop that could be targeted in a vaccine. Here we compared antibodies to linear (Ab(linear and cyclic (Ab(cyclic peptides that correspond to the SV and 4L loops and selected hypervariable (HV(2 loops for surface-binding and protective activity in vitro and in vivo. METHODS/FINDINGS: Ab(SV cyclic bound a greater number of different Opa variants than Ab(SV linear, including variants that differed by seven amino acids. Antibodies to the 4L peptide did not bind Opa-expressing bacteria. Ab(SV (cyclic and Ab(HV2 (cyclic, but not Ab(SV (linear or Ab(HV2 linear agglutinated homologous Opa variants, and Ab(HV2BD (cyclic but not Ab(HV2BD (linear blocked the association of OpaB variants with human endocervical cells. Only Ab(HV2BD (linear were bactericidal against the serum resistant parent strain. Consistent with host restrictions in the complement cascade, the bactericidal activity of Ab(HV2BD (linear was increased 8-fold when rabbit complement was used. None of the antibodies was protective when administered vaginally to mice. Antibody duration in the vagina was short-lived, however, with <50% of the antibodies recovered 3 hrs post-administration. CONCLUSIONS: We conclude that an SV loop-specific cyclic peptide can be used to induce antibodies that recognize a broad spectrum of antigenically distinct Opa variants and have agglutination abilities. HV(2 loop-specific cyclic peptides elicited antibodies with agglutination and adherence blocking abilities. The use of human complement when testing the bactericidal activity of vaccine-induced antibodies against serum resistant gonococci is also important.

  11. Iron Opacity Bump Changes the Stability and Structure of Accretion Disks in Active Galactic Nuclei

    Science.gov (United States)

    Jiang, Yan-Fei; Davis, Shane W.; Stone, James M.

    2016-08-01

    Accretion disks around supermassive black holes have regions where the Rosseland mean opacity can be larger than the electron scattering opacity due to the large number of bound-bound transitions in iron. We study the effects of this iron opacity “bump” on the thermal stability and vertical structure of radiation-pressure-dominated accretion disks, utilizing three-dimensional radiation magnetohydrodynamic (MHD) simulations in the local shearing box approximation. The simulations self-consistently calculate the heating due to MHD turbulence caused by magneto-rotational instability and radiative cooling by using the radiative transfer module based on a variable Eddington tensor in Athena. For a 5 × 108 solar mass black hole with ˜3% of the Eddington luminosity, a model including the iron opacity bump maintains its structure for more than 10 thermal times without showing significant signs of thermal runaway. In contrast, if only electron scattering and free-free opacity are included as in the standard thin disk model, the disk collapses on the thermal timescale. The difference is caused by a combination of (1) an anti-correlation between the total optical depth and the midplane pressure, and (2) enhanced vertical advective energy transport. These results suggest that the iron opacity bump may have a strong impact on the stability and structure of active galactic nucleus (AGN) accretion disks, and may contribute to a dependence of AGN properties on metallicity. Since this opacity is relevant primarily in UV emitting regions of the flow, it may help to explain discrepancies between observation and theory that are unique to AGNs.

  12. Experimental Validation of Modeled Fe Opacities at Conditions Approaching the Base of the Solar Convection Zone

    Science.gov (United States)

    Nagayama, Taisuke

    2013-10-01

    Knowledge of the Sun is a foundation for other stars. However, after the solar abundance revision in 2005, standard solar models disagree with helioseismic measurements particularly at the solar convection zone base (CZB, r ~ 0 . 7 ×RSun) [Basu, et al., Physics Reports 457, 217 (2008)]. One possible explanation is an underestimate in the Fe opacity at the CZB [Bailey et al., Phys. Plasmas 16, 058101 (2009)]. Modeled opacities are important physics inputs for plasma simulations (e.g. standard solar models). However, modeled opacities are not experimentally validated at high temperatures because of three challenging criteria required for reliable opacity measurements: 1) smooth and strong backlighter, 2) plasma condition uniformity, and 3) simultaneous measurements of plasma condition and transmission. Fe opacity experiments are performed at the Sandia National Laboratories (SNL) Z-machine aiming at conditions close to those at the CZB (i.e. Te = 190 eV, ne = 1 ×1023 cm-3). To verify the quality of the experiments, it is critical to investigate how well the three requirements are satisfied. The smooth and strong backlighter is provided by the SNL Z-pinch dynamic hohlraum. Fe plasma condition is measured by mixing Mg into the Fe sample and employing Mg K-shell line transmission spectroscopy. Also, an experiment is designed and performed to measure the level of non-uniformity in the Fe plasma by mixing Al and Mg dopants on the opposite side of the Fe sample and analyzing their spectra. We will present quantitative results on these investigations as well as the comparison of the measured opacity to modeled opacities. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.

  13. The influence of urban area opacity on biologically active UV-B irradiance

    Science.gov (United States)

    Chubarova, Nataly; Rozental', Victor

    2013-04-01

    The study of UV irradiance changes in urban area is an essential problem due to the significant effect of UV irradiance on human health which can be positive (vitamin D synthesis) and negative (erythema, skin cancer, eye damage). According to the results of several experiments within the Moscow megacity we studied the effects of urban area opacity on the different types of biologically active UV-B irradiance on the base of a specially developed mobile photometric complex snd additional measurements of the urban opacity by Nikon Fisheye Converter FC-E8. We analyzed both the level of erythemally-active irradiance and the UV eye damaging radiation using the broadband UVB-1 YES pyranometer calibrated against ultraviolet spectroradiometer Bentham DTM-300 of the Medical University of Innsbruck (courtesy of Dr. M.Blumthaler). In order to estimate the effects of the urban opacity the measurements were normalized on similar measurements at the Meteorological Observatory of Moscow State University with zero opacity. This ratio is defined as an urban radiative transmittance (URT). Different atmospheric conditions were considered. In cloudy conditions the effect of opacity on URT is much less than that in conditions when the sun disk is open from clouds. We revealed some spectral features in transmittance of biologically active UV-B irradiance which is characterized by higher URT variations in overcast cloudy conditions due to more intensive scattering and smaller direct solar radiation component. In the absence of cloudiness the effect of opacity was studied for open and screening solar disk conditions. We obtained much higher URT in UVB spectral region compared with that for total solar irradiance for screening solar disk conditions with a significant URT dependence on the opacity only in UVB spectral region. No URT dependence was obtained for total solar irradiance in these conditions. Some model calculations were fulfilled to match the experimental results.

  14. Abundances of Cloud-Related Gases in the Venus Atmosphere as Inferred from Observed Radio Opacity.

    Science.gov (United States)

    Steffes, Paul Gregory

    1982-03-01

    Various radio-analytical techniques have detected microwave opacity in the middle atmosphere of Venus, well above the main carbon dioxide opacity of the lower atmosphere. Consideration of the amount, distribution, and effects of the constituents which produce the main cloud layer at about 50 km altitude, indicate that such cloud-related gases, especially sulfuric acid vapor, are the predominant source of the observed opacity of the middle atmosphere. Theoretical and laboratory studies were made of the microwave absorption from three cloud-related gases: sulfur dioxide, sulfur trioxide, and gaseous sulfuric acid. While the measured absorption from sulfur dioxide under conditions for the middle atmosphere of Venus was found to be 50% larger than suggested by theory, the amount of sulfur dioxide required to explain the opacity as measured by radio occultation exceeded the abundance measured in situ by atmospheric probes, suggesting that there must be another important source of opacity. Sulfur trioxide was tested and found to be relatively transparent, but laboratory measurements of the microwave opacity of gaseous sulfuric acid under Venus atmospheric conditions indicate that it is an exceptionally strong absorber with absorptivity that has a surprisingly weak dependence on radio frequency. Initial theoretical studies also indicate a large absorptivity and weak frequency dependence, although the measured opacity is larger than the computed value, presumably due to deviations from Van Vleck-Weisskopf theory. The absorbing characteristics of sulfuric acid vapor appear to reconcile past inconsistencies among measurements and deductions concerning the constituents of the atmosphere of Venus, and radio occultation, radar reflection, and radio emission measurements of its opacity. The results of the current studies are used with previous data for the absorptivity of water vapor and carbon dioxide to model relative contributions to opacity as a function of height, in a way

  15. The Impact of Enhanced Iron Opacity on Massive Star Pulsations: Updated Instability Strips

    CERN Document Server

    Moravveji, Ehsan

    2015-01-01

    Recently, Bailey et al. (2015) made a direct measurement of the Iron opacity at the physical conditions of the solar tachocline. They found that the wavelength-integrated Iron opacity is roughly 75% higher that what the OP and OPAL models predict. Here, we compute new opacity tables with enhanced Iron and Nickel contributions to the Rosseland mean opacity by 75% each, and compute three dense MESA grids of evolutionary models for Galactic O- and B-type stars covering from 2.5 to 25 M$_\\odot$ from ZAMS until $T_{\\rm eff}=10\\,000$ K after the core hydrogen exhaustion. We carry out non-adiabatic mode stability analysis with GYRE, and update the extension of the instability strips of heat-driven p- and g-mode pulsators, and the hybrid pulsating SPB - $\\beta$ Cep stars. We compare the position of two confirmed late O-type $\\beta$ Cep and eight confirmed hybrid B-type pulsators with the new instability domains, and justify that $\\sim$75% enhancement, only in Iron opacity, is sufficient to consistently reproduce the ...

  16. Tamper asymmetry and its effect on transmission for x-ray driven opacity simulations

    Science.gov (United States)

    Morris, H. E.; Tregillis, I. L.; Hoffman, N. M.; Sherrill, M. E.; Fontes, C. J.; Marshall, A. J.; Urbatsch, T. J.; Bradley, P. A.

    2017-09-01

    This paper reports on synthetic transmission results from Lasnex [Zimmerman and Kruer, Comments Plasma Phys. 2, 51 (1975)] radiation-hydrodynamics simulations of opacity experiments carried out at Sandia National Laboratories' recently upgraded ZR facility. The focus is on experiments utilizing disk targets composed of a half-moon Fe/Mg mixture tamped on either end with 10-μm CH and an additional 35-μm beryllium tamper accessory on the end facing the spectrometer. Five x-ray sources with peak power ranging from 10 to 24 TW were used in the simulations to heat and backlight the opacity target. The dominant effect is that the beryllium behind the Fe/Mg mixture is denser and more opaque than the beryllium unshielded by metal during the times of greatest importance for the transmission measurement for all drives. This causes the simulated transmission to be lower than expected, and this is most pronounced for the case using the lowest drive power. While beryllium has a low opacity, its areal density is sufficiently high such that the expected reduction of the measured transmission is significant. This situation leads to an overestimate of iron opacity by 10%-215% for a photon energy range of 975-1775 eV for the 10-TW case. It is shown that if the tamper conditions are known, the transmission through each component of the target can be calculated and the resulting opacity can be corrected.

  17. Iron and Nickel spectral opacity calculations in conditions relevant for pulsating stellar envelopes and experiments

    Directory of Open Access Journals (Sweden)

    Gilles D.

    2013-11-01

    Full Text Available Seismology of stars is strongly developing. To address this question we have formed an international collaboration, OPAC, to perform specific experimental measurements, compare opacity calculations, and improve the opacity calculations in stellar codes [1]. We consider the following opacity codes: SCO, CASSANDRA, STA, OPAS, LEDCOP, OP, SCO-RCG. Their comparison has shown large differences for Fe and Ni in equivalent conditions of envelopes of type II supernova precursors, temperatures between 15 and 40 eV and densities of a few mg/cm3 [2–4]. LEDCOP, OPAS, SCO-RCG structure codes and STA give similar results and differ from OP ones for the lower temperatures and for spectral interval values [3]. In this work we discuss the role of Configuration Interaction (CI and the influence of the number of used configurations. We present and include in the opacity code comparisons new HULLAC-v9 calculations [5, 6] that include full CI. To illustrate the importance of this effect we compare different CI approximations (modes available in HULLAC-v9 [7]. These results are compared to previous predictions and to experimental data. Differences with OP results are discussed.

  18. Low-temperature gas opacity - AESOPUS: a versatile and quick computational tool

    CERN Document Server

    Marigo, Paola

    2009-01-01

    We introduce a new tool - AESOPUS: Accurate Equation of State and OPacity Utility Software - for computing the equation of state and the Rosseland mean (RM) opacities of matter in the ideal gas phase. Results are given as a function of one pair of state variables, (i.e. temperature T in the range 3.2 <= log(T) <= 4.5, and parameter R= rho/(T/10^6 K)^3 in the range -8 <= log(R) <= 1), and arbitrary chemical mixture. The chemistry is presently solved for about 800 species, consisting of almost 300 atomic and 500 molecular species. The gas opacities account for many continuum and discrete sources, including atomic opacities, molecular absorption bands, and collision-induced absorption. Several tests made on AESOPUS have proved that the new opacity tool is accurate in the results,flexible in the management of the input prescriptions, and agile in terms of computational time requirement. We set up a web-interface (http://stev.oapd.inaf.it/aesopus) which enables the user to compute and shortly retrieve ...

  19. Simultaneous unfolding of compression and opacity from time-resolved radiography

    Science.gov (United States)

    Swift, D.; Hawreliak, J.; Rothman, S.; Kritcher, A.; Doeppner, T.; Collins, G.; Gaffney, J.; Rose, S.

    2013-06-01

    Radiographs of symmetric objects can be analyzed to give the spatial variation of attenuation, as in the Abel inversion of an axisymmetric object. If the opacity is known, the mass density can be derived from the attenuation. The space- and time-variation of density is needed to make equation of state (EOS) measurements by radiography, e.g. by measuring the speed and compression of a shock. However, in our experiments using hohlraum drive at the National Ignition Facility (NIF) to perform EOS measurements at gigabar pressures with spherically-converging shocks, the opacity may vary by an order of magnitude because of ionization. We have developed a new algorithm to simultaneously deduce the compression and opacity of the sample given time-resolved radiographs with a Lagrangian location behind the shock, such as the edge of the sample. This approach relies on spatial integration to deduce the opacity in the region just behind the shock from the difference between the known and apparent mass. We assume that the change in opacity is dominated by shock-heating, so that subsequent variations, as shocked material is either released or compressed further, are negligible or can be accounted for by a model. We used this algorithm to analyze our NIF data on the Hugoniot of CH at 10-40 TPa. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  20. The significance of recurrent lung opacities in neonates on surfactant treatment for respiratory distress syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Odita, J.C. [Dept. of Radiology, Louisiana State Univ. Health Sciences Center, Shreveport (United States)

    2001-02-01

    Purpose. To determine the significance of recurrent opacities in chest radiographs of neonates on surfactant therapy for respiratory distress syndrome (RDS) after an initial period of improvement. Materials and methods. Serial pre- and post-surfactant chest radiographs on 94 preterm infants with RDS were analyzed and the pattern of chest radiographic response was classified as (a) clear, (b) recurrent opacities, and (c) no response. Their clinical characteristics were also recorded. Results. In 34 infants the RDS changes cleared within 3 days. 31 infants developed lung opacities within 10 days after an initial period of improvement. Twenty-nine infants failed to respond to the surfactant. The corresponding mean birth weights for the three groups were 1.74, 1.19, and 0.76 kg and the mean gestation ages 32.6, 27.7, and 25.4 weeks. The incidence of bronchopulmonary dysplasia (BPD) was highest among the slumping infants (72. % vs 50 % in no responders, P < 0.001) Conclusions. The pattern of chest radiographic response is primarily affected by gestation age and birth weight. Recurrent lung opacity after an initial positive response to surfactant therapy may be caused by such factors as edema from barotrauma and patent ductus arteriosus. Infants with intraventricular hemorrhage may demonstrate neurogenic edema. Other contributory factors include pneumonia and abnormal consumption of surfactant. Recurrent lung opacities after surfactant may be a predictor of chronic lung disease in the preterm infant. (orig.)

  1. Iron and Nickel spectral opacity calculations in conditions relevant for pulsating stellar envelopes and experiments

    CERN Document Server

    Gilles, D; Busquet, M; Thais, F; Loisel, G; Piau, L; Ducret, J E; Blenski, T; Blancard, C; Cossé, P; Faussurier, G; Gilleron, F; Pain, J C; Porcherot, Q; Guzik, J A; Kilcrease, D P; Magee, N H; Harris, J; Bastiani-Ceccotti, S; Delahaye, F; Zeippen, C J

    2012-01-01

    Seismology of stars is strongly developing. To address this question we have formed an international collaboration OPAC to perform specific experimental measurements, compare opacity calculations and improve the opacity calculations in the stellar codes [1]. We consider the following opacity codes: SCO, CASSANDRA, STA, OPAS, LEDCOP, OP, SCO-RCG. Their comparison has shown large differences for Fe and Ni in equivalent conditions of envelopes of type II supernova precursors, temperatures between 15 and 40 eV and densities of a few mg/cm3 [2, 3, 4]. LEDCOP, OPAS, SCO-RCG structure codes and STA give similar results and differ from OP ones for the lower temperatures and for spectral interval values [3]. In this work we discuss the role of Configuration Interaction (CI) and the influence of the number of used configurations. We present and include in the opacity code comparisons new HULLAC-v9 calculations [5, 6] that include full CI. To illustrate the importance of this effect we compare different CI approximation...

  2. Atomic structure considerations for the low-temperature opacity of Sn

    Science.gov (United States)

    Colgan, J.; Kilcrease, D. P.; Abdallah, J.; Sherrill, M. E.; Fontes, C. J.; Hakel, P.; Armstrong, G. S. J.

    2017-06-01

    We have begun a preliminary investigation into the opacity of Sn at low temperatures (emissivity and opacity of Sn is a crucial factor in determining the utility of Sn in EUV lithography, with numerous industrial implications. To this end, we have been exploring the accuracy of some approximations used in opacity models for the relevant ion stages of Sn (neutral through ∼ 18 times ionized). We find that the use of intermediate-coupling, as compared to full configuration-interaction, is not adequate to obtain accurate line positions of the important bound-bound transitions in Sn. One requires full configuration-interaction to properly describe the strong mixing between the various n = 4 sub-shells that give rise to the Δ n = 0 transitions that dominate the opacity spectrum at low temperatures. Since calculations that include full configuration-interaction for large numbers of configurations quickly become computationally prohibitive, we have explored hybrid calculations, in which full configuration-interaction is retained for the most important transitions, while intermediate-coupling is employed for all other transitions. After extensive exploration of the atomic structure properties, local-thermodynamic-equilibrium (LTE) opacities are generated using the ATOMIC code at selected temperatures and densities and compared to experiment.

  3. Capsule implosions for continuum x-ray backlighting of opacity samples at the National Ignition Facility

    Science.gov (United States)

    Opachich, Y. P.; Heeter, R. F.; Barrios, M. A.; Garcia, E. M.; Craxton, R. S.; King, J. A.; Liedahl, D. A.; McKenty, P. W.; Schneider, M. B.; May, M. J.; Zhang, R.; Ross, P. W.; Kline, J. L.; Moore, A. S.; Weaver, J. L.; Flippo, K. A.; Perry, T. S.

    2017-06-01

    Direct drive implosions of plastic capsules have been performed at the National Ignition Facility to provide a broad-spectrum (500-2000 eV) X-ray continuum source for X-ray transmission spectroscopy. The source was developed for the high-temperature plasma opacity experimental platform. Initial experiments using 2.0 mm diameter polyalpha-methyl styrene capsules with ˜20 μm thickness have been performed. X-ray yields of up to ˜1 kJ/sr have been measured using the Dante multichannel diode array. The backlighter source size was measured to be ˜100 μm FWHM, with ˜350 ps pulse duration during the peak emission stage. Results are used to simulate transmission spectra for a hypothetical iron opacity sample at 150 eV, enabling the derivation of photometrics requirements for future opacity experiments.

  4. A consistent approach for mixed detailed and statistical calculation of opacities in hot plasmas

    CERN Document Server

    Porcherot, Quentin; Gilleron, Franck; Blenski, Thomas

    2011-01-01

    Absorption and emission spectra of plasmas with multicharged-ions contain transition arrays with a huge number of coalescent electric-dipole (E1) lines, which are well suited for treatment by the unresolved transition array and derivative methods. But, some transition arrays show detailed features whose description requires diagonalization of the Hamiltonian matrix. We developed a hybrid opacity code, called SCORCG, which combines statistical approaches with fine-structure calculations consistently. Data required for the computation of detailed transition arrays (atomic configurations and atomic radial integrals) are calculated by the super-configuration code SCO (Super-Configuration Opacity), which provides an accurate description of the plasma screening effects on the wave-functions. Level energies as well as position and strength of spectral lines are computed by an adapted RCG routine of R. D. Cowan. The resulting code provides opacities for hot plasmas and can handle mid-Z elements. The code is also a po...

  5. Atomic and Molecular Opacities for Brown Dwarf and Giant Planet Atmospheres

    CERN Document Server

    Sharp, C M; Sharp, Christopher M.; Burrows, Adam

    2006-01-01

    We present a comprehensive description of the theory and practice of opacity calculations from the infrared to the ultraviolet needed to generate models of the atmospheres of brown dwarfs and extrasolar giant planets. Methods for using existing line lists and spectroscopic databases in disparate formats are presented and plots of the resulting absorptive opacities versus wavelength for the most important molecules and atoms at representative temperature/pressure points are provided. Electronic, ro-vibrational, bound-free, bound-bound, free-free, and collision-induced transitions and monochromatic opacities are derived, discussed, and analyzed. The species addressed include the alkali metals, iron, heavy metal oxides, metal hydrides, $H_2$, $H_2O$, $CH_4$, $CO$, $NH_3$, $H_2S$, $PH_3$, and representative grains. [Abridged

  6. Smoke opacity in agricultural tractor in function of interior and metropolitano diesel mixture in mamona biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Tabile, Rubens Andre [Universidade de Sao Paulo (EESC/USP), Sao Carlos, SP (Brazil). Escola de Engenharia; Lopes, Afonso; Camara, Felipe Thomas da; Grotta, Danilo Cesar Checchio; Furlani, Carlos Eduardo Angeli [Universidade Estadual Paulista (DER/UNESP), Jaboticabal, SP (Brazil). Dept. de Engenharia Rural

    2008-07-01

    The great demand for energy sources by production systems allied to scarcity of fossil fuels has motivated the development and production of biodiesel, which is a fuel produced from renewable sources. Given that, the aim of this study was to compare smoke opacity of an agricultural tractor engine, working with metropolitano and interior diesel mixed to mamona biodiesel, in seven proportions. The tests were conducted in the Departamento de Engenharia Rural of UNESP/Jaboticabal - SP. The results showed that the diesel type did influence opacity of smoke, and metropolitano diesel showed best quality. It was also observed that, as biodiesel proportion increased, smoke opacity decreased until B75, turning to increase to B100. (author)

  7. The Hybrid Detailed / Statistical Opacity Code SCO-RCG: New Developments and Applications

    CERN Document Server

    Pain, Jean-Christophe; Porcherot, Quentin; Blenski, Thomas

    2013-01-01

    We present the hybrid opacity code SCO-RCG which combines statistical approaches with fine-structure calculations. Radial integrals needed for the computation of detailed transition arrays are calculated by the code SCO (Super-configuration Code for Opacity), which calculates atomic structure at finite temperature and density, taking into account plasma effects on the wave-functions. Levels and spectral lines are then computed by an adapted RCG routine of R. D. Cowan. SCO-RCG now includes the Partially Resolved Transition Array model, which allows one to replace a complex transition array by a small-scale detailed calculation preserving energy and variance of the genuine transition array and yielding improved high-order moments. An approximate method for studying the impact of strong magnetic field on opacity and emissivity was also recently implemented.

  8. Radio-opacity of commonly consumed bony fish in kelantan, malaysia.

    Science.gov (United States)

    Irfan, M; Ahmad Helmy, A K; Wan Shah Jihan, W D

    2012-10-01

    Fish is one of the major sources of protein among Malaysians. This has made incidents of fish bones lodged in the throat fairly common clinical problems. Plain radiograph, which is the first line of imaging in such cases, has been reported to have low sensitivity. Besides the location, the degree of radio-opacity of the bone is another important factor and is species dependent. This study was undertaken to determine the radio-opacity of bones from commonly consumed fish in Malaysia. A total of 15 types of fish were identified, six of them were opaque even when embedded and three were visualized in the simulated airway. In terms of radio-opacity, the commonly consumed fish in Malaysia possessed opaque bones and this fact can help doctors identify the location of the foreign body in the throat.

  9. Sound speed and oscillation frequencies for a solar model evolved with Los Alamos ATOMIC opacities

    Science.gov (United States)

    Guzik, Joyce Ann; Fontes, Christopher; Walczak, Przemyslaw; Wood, Suzannah R.; Mussack, Katie

    2015-08-01

    Los Alamos has calculated a new generation of radiative opacities for elements with atomic number Z=1-30 with improved physics input, updated atomic data, and finer temperature grid to replace the Los Alamos LEDCOP opacities released in the year 2000. We calculate the evolution of a standard solar model including these new opacities, and compare with a model evolved using the Lawrence Livermore National Laboratory OPAL opacities released about 1996. We use the solar abundance mixture of Asplund, Grevesse, Sauval, and Scott (2009), including 2015 updates. The Los Alamos ATOMIC opacities (Colgan et al. 2013a,b) are somewhat higher than those of OPAL for temperatures and densities near the base of the solar convection zone. We compare the calculated nonadiabatic solar oscillation frequencies and solar interior sound speed to observed frequencies and helioseismic inferences. We discuss the potential for increased opacities to partially mitigate the ‘solar abundance problem’.References:J. Colgan, D.P. Kilcrease, N.H. Magee, Jr., G.S.J. Armstrong, J. Abdallah, Jr., M.E. Sherrill, C.J. Fontes, H.L. Zhang and P. Hakel, Eighth International Conference on Atomic and Molecular Data and their Applications: ICAMDATA, Gaithersburg, MD 2012, AIP Conf. Proc. No. 1545, (AIP, New York, 2013a), pp. 17-26.J. Colgan, D.P. Kilcrease, N.H. Magee, Jr, G.S.J. Armstrong, J. Abdallah, Jr., M.E. Sherrill, C.J. Fontes, H.L. Zhang and P. Hakel, High Energy Density Physics 9, 369 (2013b).

  10. Determining Visible Opacity of Emissions Using the Digital Opacity Compliance System II: Look Out EPA Method 9, Here Comes the Digital Equivalent (Finally)

    Science.gov (United States)

    2010-06-16

    Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 2 TECHNICAL APROACH • DoD Recognition of the Costs and Subjectivity of Method 9 Monitoring...Image Capture Induction Analysis Report Interface XML Service Form Print TECHNICAL APROACH •Automate Method 9 Opacity Readings •Provide Compliance...Background = JPG EXIF Example Images From a Safe Distance Capture The Plume and Background TECHNICAL APROACH 6 Induction • Registration Method • Minimization

  11. Metal Hydride and Alkali Halide Opacities in Extrasolar Giant Planets and Cool Stellar Atmospheres

    Science.gov (United States)

    Weck, Philippe F.; Stancil, Phillip C.; Kirby, Kate; Schweitzer, Andreas; Hauschildt, Peter H.

    2006-01-01

    The lack of accurate and complete molecular line and continuum opacity data has been a serious limitation to developing atmospheric models of cool stars and Extrasolar Giant Planets (EGPs). We report our recent calculations of molecular opacities resulting from the presence of metal hydrides and alkali halides. The resulting data have been included in the PHOENIX stellar atmosphere code (Hauschildt & Baron 1999). The new models, calculated using spherical geometry for all gravities considered, also incorporate our latest database of nearly 670 million molecular lines, and updated equations of state.

  12. Image Analysis on Corneal Opacity:A Novel Method to Estimate Postmortem Interval in Rabbits

    Institute of Scientific and Technical Information of China (English)

    周兰; 刘艳; 刘良; 卓荦; 梁曼; 杨帆; 任亮; 朱少华

    2010-01-01

    Corneal opacity is one of the most commonly used parameters for estimating postmortem interval(PMI).This paper proposes a new method to study the relationship between changes of corneal opacity and PMI by processing and analyzing cornea images.Corneal regions were extracted from images of rabbits' eyes and described by color-based and texture-based features,which could represent the changes of cornea at different PMI.A KNN classifier was used to reveal the association of image features and PMI.The result of...

  13. Complex asteroseismology of the hybrid B-type pulsator $\\gamma$ Pegasi: a test of stellar opacities

    CERN Document Server

    Walczak, Przemysław

    2010-01-01

    Using the updated oscillation spectrum of $\\gamma$ Pegasi, we construct a set of seismic models which reproduce two pulsational frequencies corresponding to the $\\ell=0$, p$_1$ and $\\ell=1$, g$_1$ modes. Then, we single out models which reproduce other well identified modes. Finally, we extend our seismic modelling by a requirement of fitting also values of the complex, nonadiabatic parameter $f$ associated to each mode frequency. Such complex asteroseismology of the B-type pulsators provides a unique test of stellar metallicity and opacities. In contrast to our previous studies, results for $\\gamma$ Peg indicate that both opacity tables, OPAL and OP, are equally preferred.

  14. QIKMIX: a quick-turnaround computer program for computing opacities of mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Abdallah, J. Jr.; Huebner, W.F.

    1979-05-01

    QIKMIX is a quick-turnaround computer code developed to compute the radiative Rosseland mean opacity of specified mixtures at specified temperature and density points. The QIKLIB data base, which QIKMIX uses, has been derived from the OPLIB library. For most mixtures, QIKMIX can compute opacities over a temperature range of 50 to 25,000 eV in less than 1 min of CDC 7600 computer time. The purpose of this report is to discuss the QIKLIB data base and the operation of the QIKMIX code.

  15. Photoperiodic regime influences onset of lens opacities in a non-human primate

    Directory of Open Access Journals (Sweden)

    Marko Dubicanac

    2017-05-01

    Full Text Available Background Opacities of the lens are typical age-related phenomena which have a high influence on photoreception and consequently circadian rhythm. In mouse lemurs, a small bodied non-human primate, a high incidence (more than 50% when >seven years of cataracts has been previously described during aging. Previous studies showed that photoperiodically induced accelerated annual rhythms alter some of mouse lemurs’ life history traits. Whether a modification of photoperiod also affects the onset of age dependent lens opacities has not been investigated so far. The aim of this study was therefore to characterise the type of opacity and the mouse lemurs’ age at its onset in two colonies with different photoperiodic regimen. Methods Two of the largest mouse lemur colonies in Europe were investigated: Colony 1 having a natural annual photoperiodic regime and Colony 2 with an induced accelerated annual cycle. A slit-lamp was used to determine opacities in the lens. Furthermore, a subset of all animals which showed no opacities in the lens nucleus in the first examination but developed first changes in the following examination were further examined to estimate the age at onset of opacities. In total, 387 animals were examined and 57 represented the subset for age at onset estimation. Results The first and most commonly observable opacity in the lens was nuclear sclerosis. Mouse lemurs from Colony 1 showed a delayed onset of nuclear sclerosis compared to mouse lemurs from Colony 2 (4.35 ± 1.50 years vs. 2.75 ± 0.99 years. For colony 1, the chronological age was equivalent to the number of seasonal cycles experienced by the mouse lemurs. For colony 2, in which seasonal cycles were accelerated by a factor of 1.5, mouse lemurs had experienced 4.13 ± 1.50 seasonal cycles in 2.75 ± 0.99 chronological years. Discussion Our study showed clear differences in age at the onset of nuclear sclerosis formation between lemurs kept under different

  16. Open-Source Tools for Enhancing Full-Text Searching of OPACs: Use of Koha, Greenstone and Fedora

    Science.gov (United States)

    Anuradha, K. T.; Sivakaminathan, R.; Kumar, P. Arun

    2011-01-01

    Purpose: There are many library automation packages available as open-source software, comprising two modules: staff-client module and online public access catalogue (OPAC). Although the OPAC of these library automation packages provides advanced features of searching and retrieval of bibliographic records, none of them facilitate full-text…

  17. 40 CFR 62.15380 - How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?

    Science.gov (United States)

    2010-07-01

    ... waste? (a) Use EPA Reference Method 9 in Appendix A of 40 CFR part 60 to determine compliance with the opacity limit. (b) Conduct an initial test for opacity as specified in § 60.8 of subpart A of 40 CFR part... curtain incinerators that burn 100 percent yard waste? 62.15380 Section 62.15380 Protection of...

  18. 40 CFR 75.18 - Specific provisions for monitoring emissions from common and by-pass stacks for opacity.

    Science.gov (United States)

    2010-07-01

    ... emissions from common and by-pass stacks for opacity. 75.18 Section 75.18 Protection of Environment... Provisions § 75.18 Specific provisions for monitoring emissions from common and by-pass stacks for opacity. (a) Unit using common stack.When an affected unit utilizes a common stack with other affected...

  19. Gaseous Mean Opacities for Giant Planet and Ultracool Dwarf Atmospheres over a Range of Metallicities and Temperatures

    CERN Document Server

    Freedman, Richard S; Fortney, Jonathan J; Lupu, Roxana E; Marley, Mark S; Lodders, Katharina

    2014-01-01

    We present new calculations of Rosseland and Planck gaseous mean opacities relevant to the atmospheres of giant planets and ultracool dwarfs. Such calculations are used in modeling the atmospheres, interiors, formation, and evolution of these objects. Our calculations are an expansion of those presented in Freedman et al. (2008) to include lower pressures, finer temperature resolution, and also the higher metallicities most relevant for giant planet atmospheres. Calculations span 1 microbar to 300 bar, and 75 K to 4000 K, in a nearly square grid. Opacities at metallicities from solar to 50 times solar abundances are calculated. We also provide an analytic fit to the Rosseland mean opacities over the grid in pressure, temperature, and metallicity. In addition to computing mean opacities at these local temperatures, we also calculate them with weighting functions up to 7000 K, to simulate the mean opacities for incident stellar intensities, rather than locally thermally emitted intensities. The chemical equilib...

  20. Comment on "Large enhancement in high-energy photoionization of Fe XVII and missing continuum plasma opacity"

    CERN Document Server

    Blancard, C; Cossé, Ph; Faussurier, G; Fontes, C J; Gilleron, F; Golovkin, I; Hansen, S B; Iglesias, C A; Kilcrease, D P; MacFarlane, J J; More, R M; Pain, J -C; Sherrill, M; Wilson, B G

    2016-01-01

    Recent R-matrix calculations claim to produce a significant enhancement in the opacity of Fe XVII due to atomic core excitations [S. N. Nahar & A.K. Pradhan, Phys. Rev. Letters 116, 235003 (2016), arXiv:1606.02731] and assert that this enhancement is consistent with recent measurements of higher-than-predicted iron opacities [J. E. Bailey et al., Nature 517, 56 (2015)]. This comment shows that the standard opacity models which have already been directly compared with experimental data produce photon absorption cross-sections for Fe XVII that are effectively equivalent to (and in fact larger than) the new R-matrix opacities. Thus, the new R-matrix results cannot be expected to significantly impact the existing discrepancies between theory and experiment because they produce neither a "large enhancement" nor account for "missing continuum plasma opacity" relative to standard models.

  1. 77 FR 8209 - Quality Assurance Requirements for Continuous Opacity Monitoring Systems at Stationary Sources

    Science.gov (United States)

    2012-02-14

    ... AGENCY 40 CFR Part 60 RIN 2060-AH23 Quality Assurance Requirements for Continuous Opacity Monitoring... standards as specified in federally enforceable regulations. The quality assurance requirements will be... standards to the quality assurance requirements in Appendix F of 40 CFR Part 60 in the ``Rules and...

  2. Impact of Internet Search Engines on OPAC Users: A Study of Punjabi University, Patiala (India)

    Science.gov (United States)

    Kumar, Shiv

    2012-01-01

    Purpose: The aim of this paper is to study the impact of internet search engine usage with special reference to OPAC searches in the Punjabi University Library, Patiala, Punjab (India). Design/methodology/approach: The primary data were collected from 352 users comprising faculty, research scholars and postgraduate students of the university. A…

  3. Effect of Media Opacity on Retinal Nerve Fiber Layer Thickness Measurements by Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Dae Woong Lee

    2010-01-01

    Full Text Available Purpose: To assess the effect of ocular media opacity on retinal nerve fiber layer (RNFL thickness measurements by optical coherence tomography (OCT. Methods: In this prospective, non-randomized clinical study, ocular examinations and OCT measurements were performed on 77 cataract patients, 80 laser refractive surgery patients and 90 patients whose signal strength on OCT was different on two consecutive measurements. None of the eyes had preexisting retinal or optic nerve pathology, including glaucoma. Cataracts were classified according to the Lens Opacity Classification System III (LOCS III. All eyes were scanned with the Stratus OCT using the Fast RNFL program before and three months after surgery. Internal fixation was used during scanning and all eyes underwent circular scans around the optic disc with a diameter of 3.4 mm. Results: Average RNFL thickness, quadrant thickness and signal strength significantly increased after cataract surgery (P<0.05. Cortical and posterior subcapsular cataracts, but not nuclear cataracts, had a significant influence on RNFL thickness measurements (P<0.05. There was no significant difference between OCT parameters before and after laser refractive surgery. In eyes for which different signal strengths were observed, significantly larger RNFL thickness values were obtained on scans with higher signal strengths. Conclusion: OCT parameters are affected by ocular media opacity because of changes in signal strength; cortical cataracts have the most significant effect followed by posterior subcapsular opacities. Laser refractive procedures do not seem to affect OCT parameters significantly.

  4. Gluon Radiation off Hard Quarks in a Nuclear Environment Opacity Expansion

    CERN Document Server

    Wiedemann, Urs Achim

    2000-01-01

    We study the relation between the Baier-Dokshitzer-Mueller-Peigne-Schiff (BDMPS) and Zakharov formalisms for medium-induced gluon radiation off hard quarks, and the radiation off very few scattering centers. Based on the non-abelian Furry approximation for the motion of hard partons in a spatially extended colour field, we derive a compact diagrammatic and explicitly colour trivial expression for the N-th order term of the kt-differential gluon radiation cross section in an expansion in the opacity of the medium. Resumming this quantity to all orders in opacity, we obtain Zakharov's path-integral expression (supplemented with a regularization prescription). This provides a new proof of the equivalence of the BDMPS and Zakharov formalisms which extends previous arguments to the kt-differential cross section. We give explicit analytical results up to third order in opacity for both the gluon radiation cross section of free incoming and of in-medium produced quarks. The N-th order term in the opacity expansion o...

  5. Important consequences of atomic diffusion inside main-sequence stars: opacities, extra-mixing, oscillations

    Directory of Open Access Journals (Sweden)

    Deal M.

    2017-01-01

    Full Text Available Atomic diffusion, including the effects of radiative accelerations on individual elements, leads to important variations of the chemical composition inside stars. The accumulation of important elements in specific layers leads to a local increase of the average opacity and to hydrodynamic instabilities that modify the internal stellar structure. This can also have important consequences for asteroseismology.

  6. Opportunities for Laboratory Opacity Chemistry Studies to Facilitate Characterization of Young Giant Planets and Brown Dwarfs

    Science.gov (United States)

    Marley, Mark; Freedman, Richard S.

    2015-01-01

    The thermal emission spectra of young giant planets is shaped by the opacity of atoms and molecules residing in their atmospheres. While great strides have been made in improving the opacities of important molecules, particularly NH3 and CH4, at high temperatures, much more work is needed to understand the opacity and chemistry of atomic Na and K. The highly pressure broadened fundamental band of Na and K in the optical stretches into the near-infrared, strongly influencing the shape of the Y and K spectral bands. Since young giant planets are bright in these bands it is important to understand the influences on the spectral shape. Discerning gravity and atmospheric composition is difficult, if not impossible, without both good atomic opacities as well as an excellent understanding of the relevant atmospheric chemistry. Since Na and K condense at temperatures near 500 to 600 K, the chemistry of the condensation process must be well understood as well, particularly any disequilibrium chemical pathways. Comparisons of the current generation of sophisticated atmospheric models and available data, however, reveal important shortcomings in the models. We will review the current state of observations and theory of young giant planets and will discuss these and other specific examples where improved laboratory measurements for alkali compounds have the potential of substantially improving our understanding of these atmospheres.

  7. Influence of the atmospheric opacity cycle on the near surface environment of Gale Crater on Mars

    Science.gov (United States)

    de la Torre Juarez, Manuel; Gomez-Elvira, Javier; Guzewich, Scott David; Lemmon, Mark T.; Martinez, German; Mason, Emily; Navarro, Sara; Newman, Claire E.; Smith, Michael D.; Retortillo, Alvaro de Vicente

    2016-10-01

    The Mars atmospheric dust changes the capacity of the atmosphere to absorb solar radiation or release outgoing thermal infrared radiation. This alters the atmospheric heat exchange fluxes and can interfere with the global circulation. The response of near surface pressure, temperature and winds has been characterized at the higher northern latitudes of 45 degree N at the Viking landing sites. The Rover Environmental Monitoring Station (REMS) on Curiosity allows a similar characterization at near-equatorial latitudes of 4.5 degree S. Using MCAM-880 nm opacities as a measure of local atmospheric dust load, we analyze the response of changes in surface variables measured by REMS and compare to those observed by Viking. As on Viking, diurnal and semidiurnal pressure tide amplitudes track very closely the atmospheric opacity and the mean daily pressure shows the increased wave activity. Temperature tides show a more complex response that combines its sensitivity to changes in dust and cloud opacities. Differences in UV opacities for the REMS set of finite spectral windows are explored during the dust and clear seasons.

  8. Asymptotic Giant Branch stars at low metallicity: the challenging interplay between mass loss and molecular opacities

    CERN Document Server

    Ventura, Paolo

    2010-01-01

    We investigate the main physical properties of low-metallicity Asymptotic Giant Branch stars, with the aim of quantifying the uncertainties that presently affect the predicted chemical yields of these stars, associated to mass loss and description of molecular opacities. We find that above a threshold mass, M ~ 3.5Msun for Z=0.001, the results are little dependent on the opacity treatment, as long as hot-bottom burning prevents the surface C/O ratio from exceeding unity; the yields of these massive AGB stars are expected to be mostly determined by the efficiency of convection, with a relatively mild dependence on the mass-loss description. A much higher degree of uncertainty is associated to the yields of less massive models, which critically depend on the adopted molecular opacities. An interval of masses exists, say 2.0-3.0Msun, (the exact range depends on mass loss), in which HBB may be even extinguished following the cooling produced by the opacity of C-bearing molecules. The yields of these stars are the...

  9. A Novel Technique to Calculate UV Opacity at Gale Crater from MSL/REMS Measurements

    Science.gov (United States)

    Vicente-Retortillo, Álvaro; Martínez, Germán M.; Renno, Nilton O.; Lemmon, Mark T.; Mason, Emily L.; de la Torre-Juárez, Manuel

    2016-04-01

    The Rover Environmental Monitoring Station (REMS) on board the Mars Science Laboratory (MSL) mission carries a UV sensor that for the first time is measuring the solar radiation at the surface of Mars in six bands between 200 and 380 nm [1]. Here we present a novel methodology to calculate the atmospheric opacity by using the UV photodiode output currents measured by this sensor (TELRDR products) and ancillary (ADR) data. We estimate the diffuse and total radiation signals by analyzing the events in which the direct solar beam was temporarily blocked by the masthead or by the mast of the rover. Then we use a radiative transfer model with updated radiative properties of the Martian aerosols ([2], [3]) based on the Monte-Carlo method to retrieve the UV opacity from those measurements. Therefore, this methodology is not sensitive to the degradation of the sensor due to the deposition of dust on it. In addition, by using TELRDR and ADR data, inconsistencies in the processed reduced data (ENVRDR and MODRDR products, in units of W/m2) found when the solar zenith angle relative to REMS rover frame is above 30° are avoided. In order to validate our technique, we compare the UV opacities with those derived from Mastcam observations at 880 nm. We find that both opacities show a good agreement and follow a similar seasonal trend, with the UV opacity showing values generally lower than at 880 nm. The difference between both opacities varies over the year, with the minimum difference occurring during the first half of the winter, when both opacities show their annual lowest values. The temporal variation of this difference may be used to analyze changes in the dust size distribution. [1] Gómez-Elvira, J., Armiens, C., Castañer, L., Domínguez, M., Genzer, M. et al. REMS: the environmental sensor suite for the Mars Science Laboratory rover. Space Sci. Rev., 170 (1-4), 583-640, 2012. [2] Vicente-Retortillo, A., Valero, F., Vázquez, L. and Martínez, G. M. A model to calculate

  10. Autofluorescence imaging of macular pigment: influence and correction of ocular media opacities

    Science.gov (United States)

    Sharifzadeh, Mohsen; Obana, Akira; Gohto, Yuko; Seto, Takahiko; Gellermann, Werner

    2014-09-01

    The healthy adult human retina contains in its macular region a high concentration of blue-light absorbing carotenoid compounds, known as macular pigment (MP). Consisting of the carotenoids lutein, zeaxanthin, and meso-zeaxanthin, the MP is thought to shield the vulnerable tissue layers in the retina from light-induced damage through its function as an optical attenuator and to protect the tissue cells within its immediate vicinity through its function as a potent antioxidant. Autofluorescence imaging (AFI) is emerging as a viable optical method for MP screening of large subject populations, for tracking of MP changes over time, and for monitoring MP uptake in response to dietary supplementation. To investigate the influence of ocular media opacities on AFI-based MP measurements, in particular, the influence of lens cataracts, we conducted a clinical trial with a large subject population (93 subjects) measured before and after cataract surgery. General AFI image contrast, retinal blood vessel contrast, and presurgery lens opacity scores [Lens Opacities Classification System III (LOCS III)] were investigated as potential predictors for image degradation. These clinical results show that lens cataracts can severely degrade the achievable pixel contrasts in the AFI images, which results in nominal MP optical density levels that are artifactually reduced. While LOCS III scores and blood vessel contrast are found to be only a weak predictor for this effect, a strong correlation exists between the reduction factor and the image contrast, which can be quantified via pixel intensity histogram parameters. Choosing the base width of the histogram, the presence or absence of ocular media opacities can be determined and, if needed, the nominal MP levels can be corrected with factors depending on the strength of the opacity.

  11. Investigation of the value of a photographic tool to measure self-perception of enamel opacities

    Directory of Open Access Journals (Sweden)

    Davies Gill M

    2012-10-01

    Full Text Available Abstract Background The standard measurement of oral conditions that are mainly of cosmetic concern can be carried out by a trained clinical professional, or they can be assessed and reported by the individuals who may have the condition or be aware of others who have it. Enamel opacities of anterior teeth are examples of such a condition. At a public health level the interest is only about opacities that are of aesthetic concern, so the need for an index that records opacities that the public perceive to be a problem is clear. Measurement methods carried out by highly trained professionals, using unnatural conditions are not indicated at this level. This study reports on the testing of a novel epidemiological tool that aims to report on the prevalence and impact of self-perceived enamel opacities in a population of young adolescents. Methods A dental health survey was carried out using a random sample of 12-year-old school pupils during 2008/09 by Primary Care Organisations (PCOs in England. This included the use of a novel self-perception tool which aimed to measure individual’s self-perception of the presence and impact of enamel opacities to produce population measures. This tool comprised questions asking about the presence of white marks on their teeth and whether these marks bothered the volunteers and a sheet of grouped photographs of anterior teeth showing opacities ranging from TF 0, TF 1–2 to TF 2–3. Volunteers were asked which of the groups of photographs looked more like their own teeth. Examining teams from a convenience sample of 3 PCOs from this survey agreed to undertake additional measurements to assess the value of the self-perception tool. Volunteer pupils were asked the questions on a second occasion, some time after the first and clinical examiners recorded their assessments of the most closely matching set of photographs of the volunteers on two occasions. Results The tool was feasible to use, with 74% of pupils

  12. An ab initio HCN/HNC rotational-vibrational line list and opacity function for astronomy

    Science.gov (United States)

    Harris, Gregory John

    HCN/HNC is an important molecule which is found throughout the universe. For example HCN/HNC is known to exist in comets, planetary atmospheres and the interstellar medium. HCN is also an important opacity source in carbon rich stars (C-stars). HCN masers have been observed in the circumstellar material around these C-stars and also in galaxies. Jorgensen and co-workers investigated model carbon star atmospheres in which they included HCN as an opacity source. They found that including a HCN opacity function had a remarkable effect: the atmosphere expanded by five times and the pressure of the atmosphere in the surface layers dropped by one or two orders of magnitude. This suggests that a full and detailed treatment of the rotational-vibrational spectrum of HCN/HNC could have a profound effect on the models of carbon stars, this provides the main motivation in this work. The temperatures of the stars in which HCN is an important opacity source Teff = 2000 - 3000 K. If HCN and HNC are in thermodynamic equilibrium it would be expected that HNC as well as HCN are found in significant populations. The transition dipoles of the fundamental bands of HNC are more than twice as strong as their HCN counter parts. These factors mean that both HCN and HNC will be considered, which makes a semiglobal treatment of the [H,C,N] system necessary. In this thesis an ab initio HCN/HNC linelist, from which accurate spectra and opacity functions can be calculated, is computed. Within this thesis I present least squares fits for ab initio semiglobal potential energy, dipole moment, relativistic correction and adiabatic correction surfaces. The potential energy surface (PES) is morphed for HNC geometries of the potential to improve the HNC representation of the surface. The PES and dipole moment surface (DMS) are used to perform quantum mechanical nuclear motion (rotational-vibrational) calculations with the DVR3D suite of codes. Preliminary calculations are made to optimise a ro

  13. Rovibrationally-resolved photodissociation of NH and application to the solar UV opacity

    Science.gov (United States)

    Shen, G.; Kuri, A.; Fontenla, J. M.; Stancil, P. C.; Wang, J. G.

    2014-05-01

    Rovibrationally-resolved photodissociation cross sections of NH have been evaluated using a combination of ab initio and experimentally derived potential curves and dipole transition moments. Here we present results for the three electronic transitions: 23Σ- interstellar gas, cross sections for X3Σ- (v = 0 , J = 0) to 23Σ- and 23 Π dominate, but for the high density and temperature conditions in stellar atmospheres, the LTE cross section to the A3 Π becomes competitive. Explicit application of the cross sections to the solar UV opacity will be presented. In particular, the NH photodissociation opacity is found to affect the non-LTE behavior of some species such as Cr I and V I. The work at UGA was partially supported by NASA grant HST-AR-11776.01-A. The work of JMF was supported by NASA LWS grant NNX09AJ22G. GS acknowledges travel support by the International Cooperation and Exchange Foundation of CAEP.

  14. Radiative ablation with two ionizing-fronts when opacity displays a sharp absorption edge

    CERN Document Server

    Poujade, Olivier; Vandenboomgaerde, Marc

    2014-01-01

    The interaction of a strong flux of photons with matter through an ionizing-front (I-front) is an ubiquitous phenomenon in the context of astrophysics and inertial confinement fusion (ICF) where intense sources of radiation put matter into motion. When the opacity of the irradiated material varies continuously in the radiation spectral domain, only one single I-front is formed. In contrast, as numerical simulations tend to show, when the opacity of the irradiated material presents a sharp edge in the radiation spectral domain, a second I-front (an edge-front) can form. A full description of the mechanism behind the formation of this edge-front is presented in this article. It allows to understand supernumerary shocks (edge-shocks), displayed by ICF simulations, that might affect the robustness of the design of fusion capsules in actual experiments. Moreover, it may have consequences in various domains of astrophysics where ablative flows occur.

  15. Time-Dependent Photoionization in a Dusty Medium II Evolution of Dust Distributions and Optical Opacities

    CERN Document Server

    Perna, R; Fiore, F; Perna, Rosalba; Lazzati, Davide; Fiore, Fabrizio

    2003-01-01

    The interaction of a radiation field with a dusty medium is a relevant issue in several astrophysical contexts. We use the time-dependent photoionization code in a dusty medium developed by Perna & Lazzati (2002), to study the modifications in the dust distribution and the relative optical opacities when a strong X-ray UV radiation flux propagates into a medium. We find that silicates are preferentially destroyed with respect to graphite, and the extinction curve becomes significantly flatter (hence implying less reddening), with the characteristic bump at lambda 2175 A highly suppressed, due to the destruction of the small graphite grains. This could explain the observational lack of such a feature in GRB afterglow and AGN spectra. For a very intense and highly variable source irradiating a compact and dense region, time variability in the optical opacity resulting from dust destruction can be observed on a relatively short timescale. We show that, under these circumstances, monitoring the time variabili...

  16. Femtosecond laser-assisted keratoplasty in a child with corneal opacity:case report

    Directory of Open Access Journals (Sweden)

    E. Yu. Markova

    2014-01-01

    Full Text Available Corneal opacities are the fourth cause of blindness world-wide. Over the past two centuries, various corneal transplantation (i.e., keratoplasty methods have been developed and improved. Nowadays, femtolaserssisted keratoplasty is one of most promising techniques. Femtosecond laser have several advantages that provide additional surgical benefits. Among them, no thermal injury, the ability to cut deeply on a single plane and to perform various corneal profiles should be mentioned. In children, corneal disorders are of special importance while femtosecondassisted keraatoplasty case reports are rare. Here, we describe femtosecond laserssisted penetrating keratoplasty in a girl with a rough central corneal opacity.

  17. Utilitarian Opacity Model for Aggregate Particles in Protoplanetary Nebulae and Exoplanet Atmospheres

    CERN Document Server

    Cuzzi, Jeffrey N; Davis, Sanford S

    2013-01-01

    As small solid grains grow into larger ones in protoplanetary nebulae, or in the cloudy atmospheres of exoplanets, they generally form porous aggregates rather than solid spheres. A number of previous studies have used highly sophisticated schemes to calculate opacity models for irregular, porous particles with size much smaller than a wavelength. However, mere growth itself can affect the opacity of the medium in far more significant ways than the detailed compositional and/or structural differences between grain constituents once aggregate particle sizes exceed the relevant wavelengths. This physics is not new; our goal here is to provide a model that provides physical insight and is simple to use in the increasing number of protoplanetary nebula evolution, and exoplanet atmosphere, models appearing in recent years, yet quantitatively captures the main radiative properties of mixtures of particles of arbitrary size, porosity, and composition. The model is a simple combination of effective medium theory with...

  18. Opacity of Hot and Dense Plasmas of a Mixture using an Average-Atom Approach

    Institute of Scientific and Technical Information of China (English)

    袁建民

    2002-01-01

    An average-atom model is proposed to calculate the opacities of hot and dense plasmas of a mixture. A self-consistent scheme is used to reach the requirements of the same temperature and chemical potential for all kinds ofatoms in the mixtures, the same electron density at the boundaries between the atoms, and the electrical neutralitywithin each atomic sphere. The orbital energies and wavefunctions for the bound electrons are calculated withthe Dirac-Slater equations. The occupation numbers at each orbital of each kind of atom are determined by theFermi-Dirac distribution with the same chemical potential for all kinds of atoms. As an example, the opacity ofthe mixture of Au and Cd is calculated at a few temperatures and densities.

  19. Submillimeter fourier-transform spectrometer measurements of atmospheric opacity above mauna kea.

    Science.gov (United States)

    Serabyn, E; Weisstein, E W; Lis, D C; Pardo, J R

    1998-04-20

    We present accurately calibrated submillimeter atmospheric transmission spectra obtained with a Fourier-transform spectrometer at the Caltech Submillimeter Observatory on Mauna Kea, Hawaii. These measurements cover the 0.9-0.3-mm wavelength range and are the first in a series aimed at defining the terrestrial long-wave atmospheric transmission curve. The 4.1-km altitude of the Mauna Kea site provides access to extremely low zenith water-vapor columns, permitting atmospheric observations at frequencies well above those possible from sea level. We describe the calibration procedures, present our first well-calibrated transmission spectra, and compare our results with those of a single-layer atmospheric transmission model, AT. With an empirical best-fit continuum opacity term included, this simple single-layer model provides a remarkably good fit to the opacity data for H(2)O line profiles described by either van Vleck-Weisskopf or kinetic shapes.

  20. Opacities and Spectra of the r-process Ejecta from Neutron Star Mergers

    CERN Document Server

    Kasen, Daniel; Barnes, Jennifer

    2013-01-01

    Material ejected during (or immediately following) the merger of two neutron stars may assemble into heavy elements by the r-process. The subsequent radioactive decay of the nuclei can power electromagnetic emission similar to, but significantly dimmer than, an ordinary supernova. Identifying such events is an important goal of future transient surveys, offering new perspectives on the origin of r-process nuclei and the astrophysical sources of gravitational waves. Predictions of the transient light curves and spectra, however, have suffered from the uncertain optical properties of heavy ions. Here we consider the opacity of expanding r-process material and argue that it is dominated by line transitions from those ions with the most complex valence electron structure, namely the lanthanides. For a few representative ions, we run atomic structure models to calculate radiative data for tens of millions of lines. We find that the resulting r-process opacities are orders of magnitude larger than that of ordinary ...

  1. Evolution and chemical yields of AGB stars: effects of low-temperature opacities

    CERN Document Server

    Ventura, Paolo

    2009-01-01

    The studies focused on the Thermally-Pulsing Asymptotic Giant Branch phase experienced by low- and intermediate-mass stars are extremely important in many astrophysical contexts. In particular, a detailed computation of their chemical yields is essential for several issues, ranging from the chemical evolution of galaxies, to the mechanisms behind the formation of globular clusters. Among all the uncertainties affecting the theoretical modelling of this phase, and described in the literature, it remains to be fully clarified which results are severely affected by the use of inadequate low-temperature opacities, that are in most cases calculated on the basis of the original chemical composition of the stars, and do not consider the changes in the surface chemistry due to the occurrence of the third dredge-up and hot-bottom burning. Our investigation is aimed at investigating this point. By means of full evolutionary models including new set of molecular opacities computed specifically with the AESOPUS tool, we ...

  2. CT opacity in the lungs was preceded by increased MDP activity on bone scintigraphy.

    Science.gov (United States)

    Song, Le; Zhang, Weifang; Zhang, Yanyan

    2014-11-01

    Elevated 99mTc-methylene diphosphonate (MDP) uptake in the left lung was demonstrated in a 41-year-old man with chronic lymphocytic leukemia. Lung infection was considered because the patient also had fever and pancytopenia. However, the thoracic CT performed the next day did not reveal abnormality which could explain the cause of left lung MDP activity. The repeated thoracic CTs weeks later demonstrated multiple ground-glass opacity in the left lung.

  3. Conceptual design of initial opacity experiments on the national ignition facility

    Science.gov (United States)

    Heeter, R. F.; Bailey, J. E.; Craxton, R. S.; Devolder, B. G.; Dodd, E. S.; Garcia, E. M.; Huffman, E. J.; Iglesias, C. A.; King, J. A.; Kline, J. L.; Liedahl, D. A.; McKenty, P. W.; Opachich, Y. P.; Rochau, G. A.; Ross, P. W.; Schneider, M. B.; Sherrill, M. E.; Wilson, B. G.; Zhang, R.; Perry, T. S.

    2017-02-01

    Accurate models of X-ray absorption and re-emission in partly stripped ions are necessary to calculate the structure of stars, the performance of hohlraums for inertial confinement fusion and many other systems in high-energy-density plasma physics. Despite theoretical progress, a persistent discrepancy exists with recent experiments at the Sandia Z facility studying iron in conditions characteristic of the solar radiative-convective transition region. The increased iron opacity measured at Z could help resolve a longstanding issue with the standard solar model, but requires a radical departure for opacity theory. To replicate the Z measurements, an opacity experiment has been designed for the National Facility (NIF). The design uses established techniques scaled to NIF. A laser-heated hohlraum will produce X-ray-heated uniform iron plasmas in local thermodynamic equilibrium (LTE) at temperatures eV and electron densities 21~\\text{cm}-3$ . The iron will be probed using continuum X-rays emitted in a ps, diameter source from a 2 mm diameter polystyrene (CH) capsule implosion. In this design, of the NIF beams deliver 500 kJ to the mm diameter hohlraum, and the remaining directly drive the CH capsule with 200 kJ. Calculations indicate this capsule backlighter should outshine the iron sample, delivering a point-projection transmission opacity measurement to a time-integrated X-ray spectrometer viewing down the hohlraum axis. Preliminary experiments to develop the backlighter and hohlraum are underway, informing simulated measurements to guide the final design.

  4. Limb-darkening opacity experiment using a laser-heated plasma

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, N.M.; Miller, L.W.; Mack, J.M.

    1978-10-01

    The limb-darkening technique, a method for measuring monochromatic opacity information, which has had successful astrophysical applications, is reviewed. The application of the technique to laser-produced plasmas in materials and regimes of temperature and density of interest to weapons designers is discussed, and the magnitude of the limb-darkening effect in such situations is estimated. Finally, an experimental study, now in progress, to evaluate the feasibility of this approach is described. 10 figures.

  5. Opacity measurement of a gold plasma at T{sub e} = 85 eV

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Jiyan; Yang Jiamin; Yang Guohong; Li Hang; Yuan Zheng; Zhao Yang; Xiong Gang; Bao Lihua; Huang Chenwu; Ding Yongkun; Zhang Baohan; Zheng Zhijian [Research Center of Laser Fusion, P. O. Box 919-986, Mianyang 621900 (China); Xu Yan; Wu Zheqing; Yan Jun [Institute of Applied Physics and Computational Mathematics, Beijing 100088 (China)

    2011-11-15

    The opacity of a gold plasma at the temperature of 85 eV and density of 0.02 g/cm{sup 3} was measured over the energy range from 150 eV to 1200 eV. The gold sample was heated by thermal x-ray radiation generated with a foam-baffled gold cavity. The sample transmission was obtained from the backlight, absorption and self-emission spectra measured by a time-gated, spatially resolved grating spectrometer, with the backlight and absorption spectra being measured simultaneously in a single shot and the self-emission in another shot. The temperature and density of the gold absorber were determined by the hydrodynamic simulation with Multi-1D code, which was partially tested by the reemission radiative flux measurements of the heated sample. This work permits the first test of opacity models over the photon energy range that dominates the Rosseland mean opacity at the temperature of interest for the inertial confinement fusion.

  6. Probing cosmic opacity at high redshifts with gamma-ray bursts

    CERN Document Server

    Holanda, R F L

    2014-01-01

    Probing the evolution of the universe at high redshifts with standard candles is a powerful way to discriminate dark energy models, where an open question nowadays is whether this component is constant or evolves with time. One possible source of ambiguity in this kind of analyses comes from cosmic opacity, which can mimick a dark enery behaviour. However, most tests of cosmic opacity have been restricted to the redshift range $z2$) for a flat $\\Lambda$CDM model. A possible degenerescence of the results with the adopted cosmological model is also investigated by considering a flat XCDM model. The limits on cosmic opacity in the redshift range $0

  7. Technical Note: Optical properties of desert dust with non-spherical particles: data incorporated to OPAC

    Directory of Open Access Journals (Sweden)

    P. Koepke

    2015-02-01

    Full Text Available Mineral desert dust particles in general are no spheres and assuming spherical particles, instead of more realistic shapes, has significant effects on modeled optical dust properties and so on the belonging remote sensing procedures for desert dust and the derived radiative forcing. Thus in a new version of the data base OPAC (Optical Properties of Aerosols and Clouds; Hess et al., 1998, the optical properties of the mineral particles are modeled describing the particles as spheroids with size dependent aspect ratio distributions, but with the size distributions and the spectral refractive indices not changed against the previous version of OPAC. The spheroid assumption strongly improves the scattering functions, but pays regard to the limited knowledge on particle shapes in an actual case. The relative deviations of the phase functions of non-spherical mineral particles from those of spherical particles are up to +60% at scattering angles of about 130° and up to −60% in the backscatter region, but the deviations are generally small for optical properties that are independent of the scattering angle. The improved version of OPAC (4.0 is freely available under http://www.rascin.net/

  8. Iron and molecular opacities and the evolution of Population I stars

    Science.gov (United States)

    Stothers, Richard B.; Chin, Chao-Wen

    1993-01-01

    Effects of recent opacity revisions on the evolution of Population I stars are explored over the range 1.5-60 solar masses. Opacity parameters considered include the angular momentum coupling scheme for iron, the relative iron abundance, the total metal abundance, and diatomic and triatomic molecular sources. Only the total metal abundance exerts an important control over the evolutionary tracks. Blue loops on the H-R diagram during core helium burning can be very sensitive to opacity, but only insofar as the simple formation or suppression of a blue loop is concerned. The blue loops are most robust for stellar masses around 10 solar masses. We confirm, from a comparison of stellar models with observational data, that the total metal abundance is close to solar and that convective core overshooting is likely to be very slight. The new models predict the existence of an iron convection zone in the envelope and a great widening of the main-sequence band in the H-R diagram at luminosities brighter than 100,000 solar luminosities.

  9. Changes Of Dust Opacity With Density in the Orion A Molecular Cloud

    CERN Document Server

    Roy, Arabindo; Polychroni, Danae; Bontemps, Sylvain; Abergel, Alain; Andre, Philippe; Arzoumanian, Doris; Di Francesco, James; Hill, Tracey; Konyves, Vera; Nguyen-Luong, Quang; Pezzuto, Stefano; Schneider, Nicola; Testi, Leonardo; White, Glenn

    2012-01-01

    We have studied the opacity of dust grains at submillimeter wavelengths by estimating the optical depth from imaging at 160, 250, 350, and 500 um from the Herschel Gould Belt Survey and comparing this to a column density obtained from the 2MASS-derived color excess E(J-Ks). Our main goal was to investigate the spatial variations of the opacity due to "big" grains over a variety of environmental conditions and thereby quantify how emission properties of the dust change with column (and volume) density. The central and southern areas of the Orion A molecular cloud examined here, with NH ranging from 1.5X10^21 cm^-2 to 50X10^21 cm^-2, are well suited to this approach. We fit the multi-frequency Herschel spectral energy distributions (SEDs) of each pixel with a modified blackbody to obtain the temperature, T, and optical depth, \\tau(1200), at a fiducial frequency of 1200 GHz (250 um). Using a calibration of NH/E(J-Ks)for the interstellar medium (ISM) we obtained the opacity (dust emission cross-section per H nucl...

  10. The effect of preheating and opacity on the sorption and solubility of a composite resin.

    Science.gov (United States)

    Castro, Fabrício Luscino Alves de; Pazinatto, Flávia Bittencourt; de Lima, Érick; Cesar, Paulo Francisco; Reges, Rogério Vieira

    2016-01-01

    This study evaluated the influence of material opacity and preheating on the sorption and solubility of a composite resin material. A commercially available composite resin and an 8 × 2-mm circular metallic matrix were used to fabricate a total of 60 specimens in 6 shades, of which 3 had conventional opacity (CA2, CA3, and CA3.5) and 3 were opaque (OA2, OA3, and OA3.5). Specimens were prepared at a room temperature of 25°C or preheated to 60°C (n = 5 per shade at each temperature). The specimens were weighed 3 times: M1, dried for 24 hours at 37°C; M2, stored for 7 days in 75% ethanol at 37°C; and M3, dried for an additional 24 hours at 37°C. The weights were used to calculate the sorption and solubility of the composite resin and were analyzed using 2-way analysis of variance and Tukey tests (α = 5%). Composite resin specimens heated at 60°C yielded lower values of sorption and solubility than did specimens prepared at 25°C (P composite shades were found to be similar (P > 0.05), except for shade CA2, which presented a greater mean solubility value than OA2 (P = 0.004). Therefore, preheating was beneficial, as it lowered both the sorption and solubility of the evaluated composite resin, but opacity had little effect on these properties.

  11. The assessment of lens opacity postmortem and its implication in forensics.

    Science.gov (United States)

    Stemberga, Valter; Petaros, Anja; Kovacevic, Damir; Coklo, Miran; Simicevic, Neven; Bosnar, Alan

    2013-11-01

    Visual impairment, mostly due to cataracts, has been demonstrated to be an important factor associated with traffic accidents. Although vision screening is standard procedure during licensing in order to prevent motor vehicle accidents, an eye exam is not typically administered after an accident has already occurred. Postmortem assessment of lens opacity in victims of car accidents would provide helpful information for attesting to the liability of the parties in specific accidents, determining the circumstances of the accident, and developing preventive measures for both drivers and pedestrians alike. In this paper, we explore the use of different methods and their limitations for assessing lens opacity postmortem. We discuss the possible use and benefits of a simple, but as-yet untested method: retrobulbar translucency. The method would be based on the recording of shadows formed by opaque regions of the lens while the eye is illuminated from the back with a rigid source of light. The efficacy and objectivity of the method, its reproducibility, and the inter- and intra-observer error should be tested before implementing such a technique to be regularly used to determine lens opacity in cadavers.

  12. 3.5-Year Monitoring of 225 GHz Opacity at the Summit of Greenland

    CERN Document Server

    Matsushita, Satoki; Martin-Cocher, Pierre L; Chen, Ming-Tang; Ho, Paul T P; Inoue, Makoto; Koch, Patrick M; Paine, Scott N; Turner, David D

    2016-01-01

    We present the 3.5-yr monitoring results of 225 GHz opacity at the summit of the Greenland ice sheet (Greenland Summit Camp) at an altitude of 3200 m using a tipping radiometer. We chose this site as our submillimeter telescope (Greenland Telescope; GLT) site, because its location offers favorable baselines to existing submillimeter telescopes for global-scale VLBI. The site shows a clear seasonal variation with the average opacity lower by a factor of two during winter. For the winter quartiles of 25% and 50%, the Greenland site is about 10%-30% worse than the ALMA or the South Pole sites. Estimated atmospheric transmission spectra in winter season are similar to the ALMA site at lower frequencies (450 GHz) than those at the ALMA site. This is due to the lower altitude of the Greenland site. Nevertheless, half of the winter time at the Greenland site can be used for astronomical observations at frequencies between 450 GHz and 1000 GHz with opacities 10% transmittance in the THz (1035 GHz, 1350 GHz, and 1500 ...

  13. Opacity and Color Changes of Light-Cured Ideal Makoo (IDM

    Directory of Open Access Journals (Sweden)

    M.Ghavam

    2004-03-01

    Full Text Available Statement of Problem: Esthetic materials undergo some physical and mechanical changes,during their service in oral cavity.Purpose: The aim of this study was the evaluation of the color and opacity stability of Ideal Makoo (IDM composites and compare it with Tetric ceram.Material and methods: Fifteen disk shaped samples of each material was divided into three groups of five. Different aging treatments were applied to each group. The contrast ratio of 1mm thickness and rE of the samples were evaluated at base line and after aging,using CIE system and Data Flash spectrophotometer. All the samples were kept at 37°C.Results: Baseline opacity of IDM was relatively high (77.60%±8.6. Both materials showed increased opacity after aging. The highest rE belonged to IDM samples of B group, which was significantly more than Tetric Ceram (P<0.05. Tetric Ceram, also showed some degree of color change (rE=4.60 and 5.79, on black and white background,respectively, which is noticeable clinically.Conclusion: The research showed that IDM can not be a reliable esthetic material, unless some improvements in the chemical composition will be achieved.

  14. Knoop microhardness and FT-Raman evaluation of composite resins: influence of opacity and photoactivation source

    Directory of Open Access Journals (Sweden)

    Luis Gustavo Barrotte Albino

    2011-06-01

    Full Text Available The aim of this study was to evaluate the degree of conversion by Knoop microhardness (KHN and FT-Raman spectroscopy (FTIR of one nanofilled (Filtek Supreme-3M-ESPE [FS] and one microhybrid composite (Charisma-Heraeus-Kulzer [CH], each with different opacities, namely enamel, dentin, and translucent, which were photo-activated by a quartz-tungsten-halogen lamp (QTH and a light-emitting diode (LED. Resin was bulk inserted into a disc-shaped mold that was 2.0 mm thick and 4 mm in diameter, obtaining 10 samples per group. KHN and FTIR values were analyzed by two-way ANOVA and Tukey's tests (α = 0.05. Nanofilled resin activated by a LED presented higher microhardness values than samples activated by a QTH for dentin opacity (p < 0.05. The microhybrid resin showed no differences in KHN or FTIR values with different activation sources or opacity. The nanofilled dentin and enamel resins showed lower FTIR values than the translucent resin. The KHN values of the translucent resins were not influenced by the light source.

  15. An Analysis of Source Tilting and Sub-cell Opacity Sampling for IMC

    Energy Technology Data Exchange (ETDEWEB)

    Wollaeger, Ryan T. [Los Alamos National Laboratory; Urbatsch, Todd J. [Los Alamos National Laboratory; Wollaber, Allan B. [Los Alamos National Laboratory; Densmore, Jeffery D. [Los Alamos National Laboratory

    2012-08-02

    Implicit Monte Carlo (IMC) is a stochastic method for solving the radiative transfer equations for multiphysics application with the material in local thermodynamic equilibrium. The IMC method employs a fictitious scattering term that is computed from an implicit discretization of the material temperature equation. Unfortunately, the original histogram representation of the temperature and opacity with respect to the spatial domain leads to nonphysically fast propagation of radiation waves through optically thick material. In the past, heuristic source tilting schemes have been used to mitigate the numerical teleportation error of the radiation particles in IMC that cause this overly rapid radiation wave propagation. While improving the material temperature profile throughout the time duration, these tilting schemes alone do not generally alleviate the teleportation error to suitable levels. Another means of potentially reducing teleportation error in IMC is implementing continuous sub-cell opacities based on sub-cell temperature profiles. We present here an analysis of source tilting and continuous sub-cell opacity sampling applied to various discretizations of the temperature equation. Through this analysis, we demonstrate that applying both heuristics does not necessarily yield more accurate results if the discretization of the material equation is inconsistent with the Monte Carlo sub-cell transport.

  16. Literature Review of OPAC2.0 During 2005 - 2009 in China%2005—2010年OPAC2.0国内文献研究综述

    Institute of Scientific and Technical Information of China (English)

    顾磊

    2011-01-01

    This paper gives a comprehensive literature review of OPAC2.0 during 2005 -2010 in China, which summarizes the philosophy, the overall functions and contents, the core functions, the applied techniques and the construction approach of OPAC2.0. According to the research results, the basic theory research on the OPAC2.0 in China is rich, but the practice research is relatively poor.%对2005—2010年“国内OPAC2.0”的相关研究文献进行搜集与分析,总结OPAC2.0的理念、整体功能和内容、核心功能、采用的技术及实现途径等国内发展现状。从以上研究的成果来看,我国OPAC2.0的研究在基本理论方面的探讨趋近成熟,内容丰富,但是关于实际应用方面的研究还较欠缺。

  17. Solar neutrinos and the influences of opacity, thermal instability, additional neutrino sources, and a central black hole on solar models

    Science.gov (United States)

    Stothers, R. B.; Ezer, D.

    1972-01-01

    Significant quantities that affect the internal structure of the sun are examined for factors that reduce the temperature near the sun's center. The four factors discussed are: opacity, central black hole, thermal instability, and additional neutrino sources.

  18. Configuration interaction effect on open M shell Fe and Ni LTE spectral opacities, Rosseland and Planck means

    Science.gov (United States)

    Gilles, D.; Busquet, M.; Gilleron, F.; Klapisch, M.; Pain, J.-C.

    2016-05-01

    We have recently shown that iron and nickel open M-shell opacity spectra, up to Δn = 2 are very sensitive to Configuration Interaction (CI) treatments at temperature around 15 eV and for various densities. To do so we had compared extensive CI calculations obtained with two opacity codes HULLAC-v9 and SCO-RCG. In this work we extend these comparisons to a first evaluation of CI effects on Rosseland and Planck means.

  19. Consistent dust and gas models for protoplanetary disks. I. Disk shape, dust settling, opacities, and PAHs

    Science.gov (United States)

    Woitke, P.; Min, M.; Pinte, C.; Thi, W.-F.; Kamp, I.; Rab, C.; Anthonioz, F.; Antonellini, S.; Baldovin-Saavedra, C.; Carmona, A.; Dominik, C.; Dionatos, O.; Greaves, J.; Güdel, M.; Ilee, J. D.; Liebhart, A.; Ménard, F.; Rigon, L.; Waters, L. B. F. M.; Aresu, G.; Meijerink, R.; Spaans, M.

    2016-02-01

    We propose a set of standard assumptions for the modelling of Class II and III protoplanetary disks, which includes detailed continuum radiative transfer, thermo-chemical modelling of gas and ice, and line radiative transfer from optical to cm wavelengths. The first paper of this series focuses on the assumptions about the shape of the disk, the dust opacities, dust settling, and polycyclic aromatic hydrocarbons (PAHs). In particular, we propose new standard dust opacities for disk models, we present a simplified treatment of PAHs in radiative equilibrium which is sufficient to reproduce the PAH emission features, and we suggest using a simple yet physically justified treatment of dust settling. We roughly adjust parameters to obtain a model that predicts continuum and line observations that resemble typical multi-wavelength continuum and line observations of Class II T Tauri stars. We systematically study the impact of each model parameter (disk mass, disk extension and shape, dust settling, dust size and opacity, gas/dust ratio, etc.) on all mainstream continuum and line observables, in particular on the SED, mm-slope, continuum visibilities, and emission lines including [OI] 63 μm, high-J CO lines, (sub-)mm CO isotopologue lines, and CO fundamental ro-vibrational lines. We find that evolved dust properties, i.e. large grains, often needed to fit the SED, have important consequences for disk chemistry and heating/cooling balance, leading to stronger near- to far-IR emission lines in general. Strong dust settling and missing disk flaring have similar effects on continuum observations, but opposite effects on far-IR gas emission lines. PAH molecules can efficiently shield the gas from stellar UV radiation because of their strong absorption and negligible scattering opacities in comparison to evolved dust. The observable millimetre-slope of the SED can become significantly more gentle in the case of cold disk midplanes, which we find regularly in our T Tauri models

  20. Effects of injection pressure and injection timing to exhaust gas opacity for a conventional indirect diesel engine

    Science.gov (United States)

    Budiman, Agus; Majid, Akmal Irfan; Pambayun, Nirmala Adhi Yoga; Yuswono, Lilik Chaerul; Sukoco

    2016-06-01

    In relation to pollution control and environmental friendliness, the quality of exhaust gas from diesel engine needs to be considered. The influences of injection pressure and timing to exhaust gas opacity were investigated. A series of experiments were conducted in a one-cylinder conventional diesel engine with a naturally aspirated system and indirect injection. The default specification of injection pressure was 120 kg/cm2. To investigate the injection pressure, the engine speed was retained on 1000 rpm with pressure variations from 80 to 215 kg/cm2. On the other hand, the various injection timing (8, 10, 12, 16 degrees before TDC point and exact 18 degrees before TDC point) were used to determine their effects to exhaust gas opacity. In this case, the engine speed was varied from 1000 to 2400 rpm. The injector tester was used to measure injection pressure whereas the exhaust gas opacity was determined by the smoke meter. Those data were also statistically analyzed by product moment correlation. As the results, the injection pressure of diesel engine had a non-significant positive correlation to the exhaust gas opacity with r = 0.113 and p > 5 %. Injection pressure should be adjusted to the specification listed on the diesel engine as if it was too high or too low will lead to the higher opacity. Moreover, there was a significant positive correlation between injection timing and the exhaust gas opacity in all engine speeds.

  1. GASEOUS MEAN OPACITIES FOR GIANT PLANET AND ULTRACOOL DWARF ATMOSPHERES OVER A RANGE OF METALLICITIES AND TEMPERATURES

    Energy Technology Data Exchange (ETDEWEB)

    Freedman, Richard S. [SETI Institute, Mountain View, CA (United States); Lustig-Yaeger, Jacob [Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Lupu, Roxana E.; Marley, Mark S. [Space Science and Astrobiology Division, NASA Ames Research Center, Moffett Field, CA (United States); Lodders, Katharina, E-mail: Richard.S.Freedman@nasa.gov [Planetary Chemistry Laboratory, Washington University, St. Louis, MO (United States)

    2014-10-01

    We present new calculations of Rosseland and Planck gaseous mean opacities relevant to the atmospheres of giant planets and ultracool dwarfs. Such calculations are used in modeling the atmospheres, interiors, formation, and evolution of these objects. Our calculations are an expansion of those presented in Freedman et al. to include lower pressures, finer temperature resolution, and also the higher metallicities most relevant for giant planet atmospheres. Calculations span 1 μbar to 300 bar, and 75-4000 K, in a nearly square grid. Opacities at metallicities from solar to 50 times solar abundances are calculated. We also provide an analytic fit to the Rosseland mean opacities over the grid in pressure, temperature, and metallicity. In addition to computing mean opacities at these local temperatures, we also calculate them with weighting functions up to 7000 K, to simulate the mean opacities for incident stellar intensities, rather than locally thermally emitted intensities. The chemical equilibrium calculations account for the settling of condensates in a gravitational field and are applicable to cloud-free giant planet and ultracool dwarf atmospheres, but not circumstellar disks. We provide our extensive opacity tables for public use.

  2. A test of lens opacity as an indicator of preclinical Alzheimer Disease.

    Science.gov (United States)

    Bei, Ling; Shui, Ying-Bo; Bai, Fang; Nelson, Suzanne K; Van Stavern, Gregory P; Beebe, David C

    2015-11-01

    Previous studies reported that characteristic lens opacities were present in Alzheimer Disease (AD) patients postmortem. We therefore determined whether cataract grade or lens opacity is related to the risk of Alzheimer dementia in participants who have biomarkers that predict a high risk of developing the disease. AD biomarker status was determined by positron emission tomography-Pittsburgh compound B (PET-PiB) imaging and cerebrospinal fluid (CSF) levels of Aβ42. Cognitively normal participants with a clinical dementia rating of zero (CDR = 0; N = 40) or with slight evidence of dementia (CDR = 0.5; N = 2) were recruited from longitudinal studies of memory and aging at the Washington University Knight Alzheimer's Disease Research Center. The age, sex, race, cataract type and cataract grade of all participants were recorded and an objective measure of lens light scattering was obtained for each eye using a Scheimpflug camera. Twenty-seven participants had no biomarkers of Alzheimer dementia and were CDR = 0. Fifteen participants had biomarkers indicating increased risk of AD, two of which were CDR = 0.5. Participants who were biomarker positive were older than those who were biomarker negative. Biomarker positive participants had more advanced cataracts and increased cortical light scattering, none of which reached statistical significance after adjustment for age. We conclude that cataract grade or lens opacity is unlikely to provide a non-invasive measure of the risk of developing Alzheimer dementia. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Gamma-ray opacity of the anisotropic stratified broad-line regions in blazars

    Science.gov (United States)

    Abolmasov, Pavel; Poutanen, Juri

    2016-09-01

    The GeV-range spectra of blazars are shaped not only by non-thermal emission processes internal to the relativistic jet but also by external pair-production absorption on the thermal emission of the accretion disc and the broad-line region (BLR). For the first time, we compute here the pair-production opacities in the GeV range produced by a realistic BLR accounting for the radial stratification and radiation anisotropy. Using photoionization modelling with the CLOUDY code, we calculate a series of BLR models of different sizes, geometries, cloud densities, column densities and metallicities. The strongest emission features in the model BLR are Lyα and He II Lyα. Contribution of recombination continua is smaller, especially for hydrogen, because Ly continuum is efficiently trapped inside the large optical depth BLR clouds and converted to Lyman emission lines and higher-order recombination continua. The largest effects on the gamma-ray opacity are produced by the BLR geometry and localization of the gamma-ray source. We show that when the gamma-ray source moves further from the central source, all the absorption details move to higher energies and the overall level of absorption drops because of decreasing incidence angles between the gamma-rays and BLR photons. The observed positions of the spectral breaks can be used to measure the geometry and the location of the gamma-ray emitting region relative to the BLR. Strong dependence on geometry means that the soft photons dominating the pair-production opacity may be actually produced by a different population of BLR clouds than the bulk of the observed broad line emission.

  4. Gamma-ray opacity of the anisotropic stratified broad-line regions in blazars

    Science.gov (United States)

    Abolmasov, Pavel; Poutanen, Juri

    2017-01-01

    The GeV-range spectra of blazars are shaped not only by non-thermal emission processes internal to the relativistic jet but also by external pair-production absorption on the thermal emission of the accretion disc and the broad-line region (BLR). For the first time, we compute here the pair-production opacities in the GeV range produced by a realistic BLR accounting for the radial stratification and radiation anisotropy. Using photoionization modelling with the CLOUDY code, we calculate a series of BLR models of different sizes, geometries, cloud densities, column densities and metallicities. The strongest emission features in the model BLR are Ly α and He II Ly α. Contribution of recombination continua is smaller, especially for hydrogen, because Ly continuum is efficiently trapped inside the large optical depth BLR clouds and converted to Lyman emission lines and higher order recombination continua. The largest effects on the gamma-ray opacity are produced by the BLR geometry and localization of the gamma-ray source. We show that when the gamma-ray source moves further from the central source, all the absorption details move to higher energies and the overall level of absorption drops because of decreasing incidence angles between the gamma-rays and BLR photons. The observed positions of the spectral breaks can be used to measure the geometry and the location of the gamma-ray emitting region relative to the BLR. Strong dependence on geometry means that the soft photons dominating the pair-production opacity may be actually produced by a different population of BLR clouds than the bulk of the observed broad line emission.

  5. Pulmonary Opacities and Bronchiectasis Avid on 68Ga-PSMA PET

    DEFF Research Database (Denmark)

    Bouchelouche, Kirsten; Vendelbo, Mikkel Holm

    2017-01-01

    Prostate-specific membrane antigen (PSMA) is highly expressed in prostate cancer, and the expression increases with tumor aggressiveness, metastatic disease, and recurrence. Despite its name, PSMA is also expressed in neovasculature of other tumors including lung cancer. Here, we demonstrate a case...... of increased PSMA expression on Ga-PSMA PET/CT in benign lung opacities and bronchiectasis in a prostate cancer patient. Thus, increased PSMA activity in the lungs may be due to both benign and malignant diseases and warrants further evaluation....

  6. Lens opacities in Bloom syndrome: case report and review of the literature.

    Science.gov (United States)

    Cefle, Kivanc; Ozturk, Sukru; Gozum, Nilufer; Duman, Nilgun; Mantar, Ferhan; Guler, Kerim; Palanduz, Sukru

    2007-09-01

    Bloom syndrome is an autosomal recessive disorder characterized by proportionate short stature, photosensitivity, immunodeficiency, hypogonadism and a tendency to develop various malignancies. The greatly increased frequency of sister chromatid exchanges (reciprocal exchange of homologous segments between the two sister chromatids of a chromosome) is regarded as pathognomonic for BS. We describe an 18-year old girl who presented with short stature. She was diagnosed with BS based on an extremely increased frequency of sister chromatid exchanges. Ophthalmological examination revealed mild lens opacities bilaterally, which, to our knowledge, has not been previously reported to be associated with BS.

  7. Study of Opacity Effects on Emission Lines at EXTRAP T2R RFP

    Science.gov (United States)

    Stancalie, Viorica; Rachlew, Elisabeth

    We have investigated the influence of opacity on hydrogen (H-α and Ly-β) and Li-like oxygen emission lines from the EXTRAP T2R reversed field pinch. We used the Atomic Data Analysis System (AzDAS) based on the escape factor approximation for radiative transfer to calculate metastable and excited population densities via a collisional-radiative model. Population escape factor, emergent escape factor and modified line profiles are plotted vs. optical depth. The simulated emission line ratios in the density/temperature plane are in good agreement with experimental data for electron density and temperature measurements.

  8. Ion-ion correlation effects in opacities of ultra-dense and hot plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Sauvan, P.; Minguez, E. [Instituto de Fusion Nuclear, E.T.S. de Ingenieros Industriales U.P.M., Jose Gutierrez Abascal, Madrid (Spain); Angelo, P.; Derfoul, H.; Ceccotti, T.; Poquerusse, A.; Gharbi, I.; Leboucher-Dalimier, E. [Ecole Polytechnique, Lab. pour l' Utilisation des Lasers Intenses, UMR 7605 CNRS, CEA, Ecole Polytechnique, Universite Paris 6, 91 - Palaiseau (France)

    2000-07-01

    The present work is devoted to the study of opacities for ultra-dense, hot, low Z (Z{<=}15) plasmas. The required photo-excitation and photo-ionisation cross sections are determined by the JIMENA code which allows the postprocessing of atomic data (dipole transition moments and line profiles) taking care of ion-ion correlations. These atomic data are computed with the radiative property code IDEFIX. The strong ion-ion correlation effects predicted by the simulations reinforce the impact of the experiment designed for this purpose. (authors)

  9. Beyond Nuclear Pasta: Phase Transitions and Neutrino Opacity of Non-Traditional Pasta

    CERN Document Server

    Alcain, Pablo N; Dorso, Claudio O

    2014-01-01

    In this work, we focus on different length scales within the dynamics of nucleons in conditions according to the neutron star crust, with a semiclassical molecular dynamics model, studying isospin symmetric matter at subsaturation densities. While varying the temperature, we find that a solid-liquid phase transition exists, that can be also characterized with a morphology transition. For higher temperatures, above this phase transition, we study the neutrino opacity, and find that in the liquid phase, the scattering of low momenta neutrinos remain high, even though the morphology of the structures differ significatively from those of the traditional nuclear pasta.

  10. Beyond nuclear "pasta" : Phase transitions and neutrino opacity of new "pasta" phases

    Science.gov (United States)

    Alcain, P. N.; Giménez Molinelli, P. A.; Dorso, C. O.

    2014-12-01

    In this work, we focus on different length scales within the dynamics of nucleons in conditions according to the neutron star crust, with a semiclassical molecular dynamics model, studying isospin symmetric matter at subsaturation densities. While varying the temperature, we find that a solid-liquid phase transition exists, which can be also characterized with a morphology transition. For higher temperatures, above this phase transition, we study the neutrino opacity, and find that in the liquid phase, the scattering of low momenta neutrinos remain high, even though the morphology of the structures differ significatively from those of the traditional nuclear pasta.

  11. A 65-year-old man with persistent cough and large nodular opacity.

    Science.gov (United States)

    Grimes, Brandon S; Albores, Jeffrey; Barjaktarevic, Igor

    2015-01-01

    A 65-year-old Asian man with a history of chronic hepatitis B infection presented to our pulmonary clinic for second opinion of his chronic, persistent, nonproductive cough. He was evaluated 10 months earlier with chest CT scan, which revealed a large lingular nodular opacity that was diagnosed as nodular cryptogenic organizing pneumonia by CT scan-guided percutaneous lung biopsy. Systemic corticosteroids were initiated and continued over the next 10 months. The dry cough persisted, and he developed intermittent left-sided pleuritic chest pain. He denied fevers, night sweats, hemoptysis, weight loss, or dyspnea. He was a lifelong nonsmoker and moved to the United States from China during childhood.

  12. Calculation of opacities and emissivities for carbon plasmas under NLTE and LTE conditions

    Energy Technology Data Exchange (ETDEWEB)

    Gil, J.M.; Rodriguez, R.; Florido, R.; Rubiano, J.G.; Martel, P. [Las Palmas de Gran Canaria Univ., Dept. de Fisica (Spain); Sauvan, P. [Universidad Nacional de Educacion a Distancia, Dept. de Ingenieria Energetica, Madrid (Spain); Minguez, E. [Madrid Univ. Politecnica, Instituto de Fusion Nuclear-DENIM (Spain)

    2006-06-15

    We calculate different optical properties for carbon plasma in a wide range of temperatures and densities by using ATOM3R-OP code which has been recently developed. In this code we have implemented the rate equations, the Saha equation (for local thermodynamic equilibrium) and the coronal equilibrium model. We have calculated average ionizations, level populations, opacities and emissivities and we focus our study on the identification with our code of coronal equilibrium, non-local thermodynamic equilibrium and local thermodynamic equilibrium regions for this kind of plasma. Moreover, we analyse the differences in the optical properties when they are calculated in non-local thermodynamic equilibrium and local thermodynamic equilibrium. (authors)

  13. A novel congenital ichthyosiform syndrome with associated panhypopituitarism, corneal opacities and mental retardation.

    Science.gov (United States)

    Pandhi, Deepika; Khanna, Deepshikha; Singal, Archana; Madhu, Sri Venkata

    2007-11-01

    A 15-year-old male presented with ichthyosis since infancy with panhypopituitarism, short stature and knock-knees, delayed puberty, high scrotal retractile testes, mental retardation and corneal opacities. He developed recurrent tinea capitis and tinea corporis. The clinical symptomatology indicates that this case cannot be considered as a subtype of inherited ichthyosis group, but suggests a new syndrome as a separate nosologic entity. Two previously reported cases with possibly the same syndrome also had ichthyosis associated with variable endocrinopathy. Thorough endocrinological evaluation and appropriate intervention in patients of ichthyosis with short stature may reduce the morbidity associated with retarded skeletal growth and gonadal maturation.

  14. FTS Measurements of Submillimeter-Wave Atmospheric Opacity at Pampa la Bola II : Supra-Terahertz Windows and Model Fitting

    Science.gov (United States)

    Matsushita, Satoki; Matsuo, Hiroshi; Pardo, Juan R.; Radford, Simon J. E.

    1999-10-01

    A second observing run aimed to measure the millimeter and submillimeter-wave (150-1500 GHz or 2 mm-200 mu m) atmospheric opacity was carried out with a Fourier Transform Spectrometer (FTS) at Pampa la Bola, 4800 m above sea level in northern Chile. We obtained high transmission spectra, showing up to ~ 67% transmission at submillimeter-wave windows. The observed spectra can be well modeled by newly developed radiative-transfer calculations. Correlations between 220 GHz and submillimeter-wave opacities were reanalized, including the new data set. The results show almost identical trends as the ones resulting from the first measurements. We also identified supra-terahertz windows (located around 1035 GHz, 1350 GHz, and 1500 GHz), which could not be seen in our first measurements. Opacity correlations between the 220 GHz and these new windows are derived for the first time. Combined with a statistical study of the 225 GHz opacity data of the Chajnantor site (7 km apart from Pampa la Bola), it is estimated that submillimeter-wave observations can be done with zenith opacity less than 1.0 (at the most transparent frequency in those windows) for about 50% of the winter season.

  15. Parallax diagnostics of radiation source geometric dilution for iron opacity experiments

    CERN Document Server

    Nagayama, T; Loisel, G; Rochau, G A; Falcon, R E

    2014-01-01

    Experimental tests are in progress to evaluate the accuracy of the modeled iron opacity at solar interior conditions [J.E. Bailey et al., Phys. Plasmas 16, 058101 (2009)]. The iron sample is placed on top of the Sandia National Laboratories z-pinch dynamic hohlraum (ZPDH) radiation source. The samples are heated to 150 - 200 eV electron temperatures and 7e21 - 4e22 e/cc electron densities by the ZPDH radiation and backlit at its stagnation [T. Nagayama et al., Phys. Plasmas 21, 056502 (2014)]. The backlighter attenuated by the heated sample plasma is measured by four spectrometers along +/- 9 degree with respect to the z-pinch axis to infer the sample iron opacity. Here we describe measurements of the source-to-sample distance that exploit the parallax of spectrometers that view the half-moon-shaped sample from +/-9 degree. The measured sample temperature decreases with increased source-to-sample distance. This distance must be taken into account for understanding the sample heating.

  16. Temporal and spatial mapping of surface albedo and atmospheric dust opacity on Mars

    Science.gov (United States)

    Lee, S. W.; Clancy, R. T.; Gladstone, G. R.

    1993-01-01

    The Mariner 9 and Viking provided abundant evidence that eolian processes are active over much of the surface of Mars. Past studies have demonstrated that variations in regional albedo and wind-streak patterns are indicative of sediment transport through a region, while thermal inertia data (derived from the Viking Infrared Thermal Mapper (IRTM) dataset) are indicative of the degree of surface mantling by dust deposits. The visual and thermal data are therefore diagnostic of whether net erosion or deposition of dust-storm fallout is taking place currently and whether such processes have been active in a region over the long term. These previous investigations, however, have not attempted to correct for the effects of atmospheric dust loading on observations of the martian surface, so quantitative studies of current sediment transport rates have included large errors due to uncertainty in the magnitude of this 'atmospheric component' of the observations. We have developed a radiative transfer model that allows the atmospheric dust opacity to be determined from IRTM thermal observations. Corrections for the effects of atmospheric dust loading on observations of surface albedo can also be modeled. This approach to determining 'dust-corrected surface albedo' incorporates the atmospheric dust opacity, the single-scattering albedo and particle phase function of atmospheric dust, and the bidirectional reflectance of the surface, and it accounts for variable lighting and viewing geometry.

  17. Digitisation of films and texture analysis for digital classification of pulmonary opacities

    Energy Technology Data Exchange (ETDEWEB)

    Desaga, J.F.; Dengler, J.; Wolf, T.; Engelmann, U.; Scheppelmann, D.; Meinzer, H.P.

    1988-04-01

    The study aimed at evaluating the effect of different methods of digitisation of radiographic films on the digital classification of pulmonary opacities. Test sets from the standard of the International Labour Office (ILO) Classification of Radiographs of Pneumoconiosis were prepared by film digitsation using a scanning microdensitometer or a video digitiser based on a personal computer equipped with a real time digitiser board and a vidicon or a Charge Coupled Device (CCD) camera. Seven different algorithms were used for texture analysis resulting in 16 texture parameters for each region. All methods used for texture analysis were independent of the mean grey value level and the size of the image analysed. Classification was performed by discriminant analysis using the classes from the ILO classification. A hit ratio of at least 85% was achieved for a digitisation by scanner digitisation or the vidicon, while the corresponding results of the CCD camera were significantly less good. Classification by texture analysis of opacities of chest X-rays of pneumoconiosis digitised by a personal computer based video digitiser and a vidicon are of equal quality compared to digitisation by a scanning microdensitometer. Correct classification of 90% was achieved via the described statistical approach.

  18. Solar Activity and Cloud Opacity Variations A Modulated Cosmic-Ray Ionization Model

    CERN Document Server

    Marsden, D C; Marsden, David; Lingenfelter, Richard E.

    2002-01-01

    The observed correlation between global low cloud amount and the flux of high energy cosmic-rays supports the idea that ionization plays a crucial role in tropospheric cloud formation. We explore this idea quantitatively with a simple model of cosmic-ray ionization enhancement of the formation of cloud condensation nuclei. This model predicts that solar modulation of the cosmic-ray ionization rate should be correlated with cloud opacity where the atmospheric aerosol concentration is low. Using the International Satellite Cloud Climatology Project database (1983-1993), we find that the mean opacity of low latitude (40 degrees) clouds, on the other hand, show an anti-correlation with cosmic-ray flux, which we suggest may be a feedback effect resulting from the thicker low latitude clouds. We also show that the previously reported correlations of cloud amount with cosmic-ray flux probably result from the variations in longwave emissivity expected from our model, and not from variations in cloud amount. Further g...

  19. Biodegradable X-ray markers of controlled radio-opacity. Temporary position measurements in bone.

    Science.gov (United States)

    Stallmann, Hein P; Faber, Chris; Plokker, Herbert M; Wuisman, Paul I J M

    2005-02-01

    In order to analyze X-ray markers for potential use in biodegradable implants or radiostereogrammatic analysis (RSA), we combined iopromide contrast fluid with biodegradable calcium phosphate cement. The radio-opacity of 10 x 10 mm markers containing different iodine concentrations (0, 120, 240, 360 and 720 mg per gram cement) was compared to an aluminium wedge of increasing (1-10 mm) thickness. The addition of iopromide increased the radio-opacity in a dose-dependent manner, which was comparable to 9-mm aluminium at concentrations of 240-720 mg/g. Radiographs of markers placed in explanted rabbit and in human femora were made to investigate the clinical accuracy for position determination. Markers of 1 x 1 mm (120 mg/g) were clearly discernable in all femora, and could be used to adequately measure distances of 5-45 mm (accuracy 0.10-2.19 mm). These markers might be embedded in biodegradable implants or used as temporary markers in the bone to analyze postoperative position on radiographs.

  20. Consistent dust and gas models for protoplanetary disks. I. Disk shape, dust settling, opacities, and PAHs

    CERN Document Server

    Woitke, P; Pinte, C; Thi, W -F; Kamp, I; Rab, C; Anthonioz, F; Antonellini, S; Baldovin-Saavedra, C; Carmona, A; Dominik, C; Dionatos, O; Greaves, J; Güdel, M; Ilee, J D; Liebhart, A; Ménard, F; Rigon, L; Waters, L B F M; Aresu, G; Meijerink, R; Spaans, M

    2015-01-01

    We propose a set of standard assumptions for the modelling of Class II and III protoplanetary disks, which includes detailed continuum radiative transfer, thermo-chemical modelling of gas and ice, and line radiative transfer from optical to cm wavelengths. We propose new standard dust opacities for disk models, we present a simplified treatment of PAHs sufficient to reproduce the PAH emission features, and we suggest using a simple treatment of dust settling. We roughly adjust parameters to obtain a model that predicts typical Class II T Tauri star continuum and line observations. We systematically study the impact of each model parameter (disk mass, disk extension and shape, dust settling, dust size and opacity, gas/dust ratio, etc.) on all continuum and line observables, in particular on the SED, mm-slope, continuum visibilities, and emission lines including [OI] 63um, high-J CO lines, (sub-)mm CO isotopologue lines, and CO fundamental ro-vibrational lines. We find that evolved dust properties (large grains...

  1. Diagnostic development in precise opacity measurement of radiatively heated Al plasma on Shenguang II laser facility

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Yang [Wuhan National Laboratory for Optoelectronics, Institute of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Yang Jiamin; Zhang Jiyan [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Liu Jinsong; Yuan Xiao [Wuhan National Laboratory for Optoelectronics, Institute of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Jin Fengtao [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Department of Physics, National University of Defense Technology, Changsha 410073 (China)

    2009-04-15

    Simultaneous measurements of the self-emission spectrum, the backlighting source spectrum, and the transmission spectrum in one shot, which reduce the experimental uncertainties from shot-to-shot fluctuation, are essential for precise opacity experiments. In order to achieve precise absorption spectrum of Al plasmas, a special half sample sandwich target was designed and short backlighter was used to provide time- and space-resolving diagnostics on the Shenguang II high power laser facility. In the measurement, a cylindrical cavity with CH foam baffles was used to provide a clean x-ray radiation environment for sample heating. The x-ray source spectrum, the transmission spectrum, and the self-emission spectrum of the soft x-ray heated Al sample were recorded in one shot with a penta-erythritol tetrakis (hydroxymethy) methane C(CH{sub 2}OH){sub 4} (PET) crystal spectrometer by using the point-projection method. Experimental results have been compared with the calculation results of a detailed level accounting opacity code.

  2. FEEST: A method for tabulating equation of state and opacity tables

    Energy Technology Data Exchange (ETDEWEB)

    White, R.H.

    1993-03-01

    The tabulation of equations of state presently used by codes which carry temperature and density as independent variables, provides separate tables for pressure (P) and specific internal energy ({var_epsilon}) as functions of the temperature (T) and density ({rho}). Both P and {var_epsilon} are determined by bi-quadratic interpolation in tables of P and {var_epsilon} values arranged on a rectangular grid in the T-{rho} plane. The system was designed for use on the 709-7094 generation of computers and has been used, essentially unmodified, for approximately twenty years. It has long been recognized that this ``Bi-quadratic Tabulation`` system has several drawbacks. In this paper, the authors describe the Free Energy Equations of State Tabulation (FEEST) scheme which is intended to replace the presently used Bi-Quadratic Tabulation. The Bi-quadratic Tabulation, now used, treats opacities ({kappa}) in the same way as P and {var_epsilon} expect that (1/T) replaces T as one of the interpolation variables. Since {kappa} may vary inversely with a high (3 to 8) power of T and since bi-quadratic interpolation in (1/T) includes terms only up to T{sup {minus}2}, opacity tables have been large and difficult to produce.

  3. Opacity broadening and interpretation of suprathermal CO linewidths: Macroscopic Turbulence and Tangled Molecular Clouds

    CERN Document Server

    Hacar, A; Burkert, A; Goldsmith, P

    2016-01-01

    (Abridged) Many of the observed CO line profiles exhibit broad linewidths that greatly exceed the thermal broadening expected within molecular clouds. These suprathermal CO linewidths are assumed to be originated from the presence of unresolved supersonic motions inside clouds. Typically overlooked in the literature, in this paper we aim to quantify the impact of the opacity broadening effects on the current interpretation of the CO suprathermal line profiles. Without any additional contributions to the gas velocity field, a large fraction of the apparently supersonic (${\\cal M}\\sim$2-3) linewidths measured in both $^{12}$CO and $^{13}$CO (J=1-0) lines can be explained by the saturation of their corresponding sonic-like, optically-thin C$^{18}$O counterparts assuming standard isotopic fractionation. Combined with the presence of multiple components detected in our C$^{18}$O spectra, these opacity effects seem to be also responsible of the highly supersonic linewidths (${\\cal M}>$8-10) detected in the broadest...

  4. Gamma-ray opacity of the anisotropic stratified broad-line regions in blazars

    CERN Document Server

    Abolmasov, Pavel

    2016-01-01

    The GeV-range spectra of blazars are shaped not only by non-thermal emission processes internal to the relativistic jet but also by external pair-production absorption on the thermal emission of the accretion disc and the broad-line region (BLR). For the first time, we compute here the pair-production opacities in the GeV range produced by a realistic BLR accounting for the radial stratification and radiation anisotropy. Using photoionization modelling with the CLOUDY code, we calculate a series of BLR models of different sizes, geometries, cloud densities, column densities and metallicities. The strongest emission features in the model BLR are Ly$\\alpha$ and HeII Ly$\\alpha$. Contribution of recombination continua is smaller, especially for hydrogen, because Ly continuum is efficiently trapped inside the large optical depth BLR clouds and converted to Lyman emission lines and higher-order recombination continua. The largest effects on the gamma-ray opacity are produced by the BLR geometry and localization of ...

  5. Minimum Core Masses for Giant Planet Formation With Realistic Equations of State and Opacities

    CERN Document Server

    Piso, Ana-Maria A; Murray-Clay, Ruth A

    2014-01-01

    Giant planet formation by core accretion requires a core that is sufficiently massive to trigger runaway gas accretion in less that the typical lifetime of protoplanetary disks. We explore how the minimum required core mass, M_crit, depends on a non-ideal equation of state and on opacity changes due to grain growth, across a range of stellocentric distances from 5-100 AU. This minimum M_crit applies when planetesimal accretion does not substantially heat the atmosphere. Compared to an ideal gas polytrope, the inclusion of molecular hydrogen (H_2) dissociation and variable occupation of H_2 rotational states increases M_crit. Specifically, M_crit increases by a factor of ~2 if the H_2 spin isomers, ortho- and parahydrogen, are in thermal equilibrium, and by a factor of ~2-4 if the ortho-to-para ratio is fixed at 3:1. Lower opacities due to grain growth reduce M_crit. For a standard disk model around a Solar mass star, we calculate M_crit ~ 8 M_Earth at 5 AU, decreasing to ~5 M_Earth at 100 AU, for a realistic ...

  6. Effect of EGR on the exhaust gas temperature and exhaust opacity in compression ignition engines

    Indian Academy of Sciences (India)

    Avinash Kumar Agrawal; Shrawan Kumar Singh; Shailendra Sinha; Mritunjay Kumar Shukla

    2004-06-01

    In diesel engines, NOx formation is a highly temperature-dependent phenomenon and takes place when the temperature in the combustion chamber exceeds 2000 K. Therefore, in order to reduce NOx emissions in the exhaust, it is necessary to keep peak combustion temperatures under control. One simple way of reducing the NOx emission of a diesel engine is by late injection of fuel into the combustion chamber. This technique is effective but increases fuel consumption by 10–15%, which necessitates the use of more effective NOx reduction techniques like exhaust gas recirculation (EGR). Re-circulating part of the exhaust gas helps in reducing NOx, but appreciable particulate emissions are observed at high loads, hence there is a trade-off between NOx and smoke emission. To get maximum benefit from this trade-off, a particulate trap may be used to reduce the amount of unburnt particulates in EGR, which in turn reduce the particulate emission also. An experimental investigation was conducted to observe the effect of exhaust gas re-circulation on the exhaust gas temperatures and exhaust opacity. The experimental setup for the proposed experiments was developed on a two-cylinder, direct injection, air-cooled, compression ignition engine. A matrix of experiments was conducted for observing the effect of different quantities of EGR on exhaust gas temperatures and opacity.

  7. Opacity broadening and interpretation of suprathermal CO linewidths: Macroscopic turbulence and tangled molecular clouds

    Science.gov (United States)

    Hacar, A.; Alves, J.; Burkert, A.; Goldsmith, P.

    2016-06-01

    Context. Since their first detection in the interestellar medium, (sub-)millimeter line observations of different CO isotopic variants have routinely been employed to characterize the kinematic properties of the gas in molecular clouds. Many of these lines exhibit broad linewidths that greatly exceed the thermal broadening expected for the low temperatures found within these objects. These observed suprathermal CO linewidths are assumed to originate from unresolved supersonic motions inside clouds. Aims: The lowest rotational J transitions of some of the most abundant CO isotopologues, 12CO and 13CO, are found to present large optical depths. In addition to well-known line saturation effects, these large opacities present a non-negligible contribution to their observed linewidths. Typically overlooked in the literature, in this paper we aim to quantify the impact of these opacity broadening effects on the current interpretation of the CO suprathermal line profiles. Methods: Combining large-scale observations and LTE modeling of the ground J = 1-0 transitions of the main 12CO, 13CO, C18O isotopologues, we have investigated the correlation of the observed linewidths as a function of the line opacity in different regions of the Taurus molecular cloud. Results: Without any additional contributions to the gas velocity field, a large fraction of the apparently supersonic (ℳ ~ 2-3) linewidths measured in both 12CO and 13CO (J = 1-0) lines can be explained by the saturation of their corresponding sonic-like, optically thin C18O counterparts assuming standard isotopic fractionation. Combined with the presence of multiple components detected in some of our C18O spectra, these opacity effects also seem to be responsible for most of the highly supersonic linewidths (ℳ > 8-10) detected in some of the broadest 12CO and 13CO spectra in Taurus. Conclusions: Our results demonstrate that most of the suprathermal 12CO and 13CO linewidths reported in nearby clouds like Taurus

  8. Propuesta metodológica de evaluación de interfaces de OPACs. INNOPAC versus UNICORN.

    Directory of Open Access Journals (Sweden)

    Rodríguez Bravo, Blanca

    2004-03-01

    Full Text Available The aim of this paper is to present a model of academic OPACs evaluation with the objective of sharing a procedure and some parameters and indicators established. There are two fundamental parameters, the interface searching services and the characteristics of the interface: design, ergonomics and user-friendliness. The present work provides also, the main results of the evaluations of ten OPACs implemented with INNOPAC and UNICORN previously accomplished. Now we will contrast both systems. We consider that universities are institutions that demand OPACs with better services to those of other informative units. The present evaluation has considered the users needs in academic libraries.

    Los propósitos de este trabajo son presentar un modelo de evaluación de OPACs universitarios con el objetivo de compartir un procedimiento y unos parámetros e indicadores establecidos a este fin. Dos son los parámetros fundamentales, las prestaciones de búsqueda de la interfaz y las características de la propia interfaz: diseño, ergonomía y amigabilidad. El presente estudio ofrece, asimismo, los principales resultados de las evaluaciones realizadas en trabajos previos sobre diez OPACs implementados con INNOPAC y UNICORN, que nos permiten ahora contrastar ambos sistemas. Partimos de la consideración de que las universidades son instituciones que por su idiosincrasia exigen OPACs con prestaciones superiores a las de otras unidades informativas. En este sentido, la formalización de los criterios evaluativos ha considerado las necesidades de los usuarios de las bibliotecas universitarias.

  9. Temporal evolution of UV opacity and dust particle size at Gale Crater from MSL/REMS measurements

    Science.gov (United States)

    Vicente-Retortillo, Álvaro; Martinez, German; Renno, Nilton O.; Lemmon, Mark T.; Mason, Emily; De la Torre, Manuel

    2016-10-01

    A better characterization of the size, radiative properties and temporal variability of suspended dust in the Martian atmosphere is necessary to improve our understanding of the current climate of Mars. The REMS UV sensor onboard the Mars Science Laboratory (MSL) Curiosity rover has performed ground-based measurements of solar radiation in six different UV spectral bands for the first time on Mars.We developed a novel technique to retrieve dust opacity and particle size from REMS UV measurements. We use the electrical output current (TELRDR products) of the six photodiodes and the ancillary data (ADR products) to avoid inconsistencies found in the processed data (units of W/m2) when the solar zenith angle is above 30°. In addition, we use TELRDR and ADR data only in events during which the Sun is temporally blocked by the rover's masthead or mast to mitigate uncertainties associated to the degradation of the sensor due to the deposition of dust on it. Then we use a radiative transfer model with updated dust properties based on the Monte-Carlo method to retrieve the dust opacity and particle size.We find that the seasonal trend of UV opacity is consistent with opacity values at 880 nm derived from Mastcam images of the Sun, with annual maximum values in spring and in summer and minimum values in winter. The interannual variability is low, with two local maxima in mid-spring and mid-summer. Finally, dust particle size also varies throughout the year with typical values of the effective radius in the range between 0.5 and 2 μm. These variations in particle size occur in a similar way to those in dust opacity; the smallest sizes are found when the opacity values are the lowest.

  10. Monte Carlo Simulation of Opacities of Hot and Dense Au Plasma in the Unresolved Transition Array Approximation

    Institute of Scientific and Technical Information of China (English)

    程新路; 杨莉; 张红; 杨向东

    2002-01-01

    The opacity, and its Planck and Rosseland mean values, of the hot and dense Au plasma in local thermodynamicsequilibrium are studied by the Monte Carlo method based on the unresolved transition array (UTA) approxima-tion. The average ion model and the Saha equation are used to determine the atomic level populations. Theresult gives a more detailed structure for frequency-dependent opacity than the popularly used super transitionarray or UTA in the photon energy range of 500eV to 2000eV. The Monte Carlo method can give a result betterthan that of the UTA, with almost the same computation effort.

  11. CHANGES OF DUST OPACITY WITH DENSITY IN THE ORION A MOLECULAR CLOUD

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Arabindo; Martin, Peter G.; Nguyen-Luong, Quang [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Polychroni, Danae [INAF-IFSI, via Fosso del Cavaliere 100, I-00133 Roma (Italy); Bontemps, Sylvain; Schneider, Nicola [Universite de Bordeaux, LAB, UMR5804, F-33270 Floirac (France); Abergel, Alain; Konyves, Vera [IAS, CNRS (UMR 8617), Universite Paris-Sud 11, Batiment 121, F-91400 Orsay (France); Andre, Philippe; Arzoumanian, Doris; Hill, Tracey [Laboratoire AIM, C.E.A. Saclay, F-90091 Gif-sur-Yvette (France); Di Francesco, James [National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Pezzuto, Stefano [Istituto di Astrofisica e Planetologia Spaziali IAPS, Istituto Nazionale di Astrofisica INAF, via Fosso del Cavaliere 100, I-00133 Roma (Italy); Testi, Leonardo [European Southern Observatory, Karl Schwarzschild Strasse 2, D-85748 Garching (Germany); White, Glenn [Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes, MK7 6AA (United Kingdom)

    2013-01-20

    We have studied the opacity of dust grains at submillimeter wavelengths by estimating the optical depth from imaging at 160, 250, 350, and 500 {mu}m from the Herschel Gould Belt Survey and comparing this to a column density obtained from the Two Micron All Sky Survey derived color excess E(J - K {sub s}). Our main goal was to investigate the spatial variations of the opacity due to 'big' grains over a variety of environmental conditions and thereby quantify how emission properties of the dust change with column (and volume) density. The central and southern areas of the Orion A molecular cloud examined here, with N {sub H} ranging from 1.5 Multiplication-Sign 10{sup 21} cm{sup -2} to 50 Multiplication-Sign 10{sup 21} cm{sup -2}, are well suited to this approach. We fit the multi-frequency Herschel spectral energy distributions (SEDs) of each pixel with a modified blackbody to obtain the temperature, T, and optical depth, {tau}{sub 1200}, at a fiducial frequency of 1200 GHz (250 {mu}m). Using a calibration of N {sub H}/E(J - K{sub s} ) for the interstellar medium (ISM) we obtained the opacity (dust emission cross-section per H nucleon), {sigma}{sub e}(1200), for every pixel. From a value {approx}1 Multiplication-Sign 10{sup -25} cm{sup 2} H{sup -1} at the lowest column densities that is typical of the high-latitude diffuse ISM, {sigma}{sub e}(1200) increases as N {sup 0.28} {sub H} over the range studied. This is suggestive of grain evolution. Integrating the SEDs over frequency, we also calculated the specific power P (emission power per H) for the big grains. In low column density regions where dust clouds are optically thin to the interstellar radiation field (ISRF), P is typically 3.7 Multiplication-Sign 10{sup -31} W H{sup -1}, again close to that in the high-latitude diffuse ISM. However, we find evidence for a decrease of P in high column density regions, which would be a natural outcome of attenuation of the ISRF that heats the grains, and for

  12. The relative frequencies of causes of widespread ground-glass opacity: A retrospective cohort

    Energy Technology Data Exchange (ETDEWEB)

    Hewitt, Michael G., E-mail: Mike_hewitt@me.com; Miller, Wallace T., E-mail: Wallace.miller@uphs.upenn.edu; Reilly, Thomas J., E-mail: thomasjreilly@comcast.net; Simpson, Scott, E-mail: Simpson80@gmail.com

    2014-10-15

    Highlights: • The most common cause of widespread ground-glass opacities is hydrostatic pulmonary edema. • Associated findings such as air-trapping and centrilobular nodules are highly specific for hypersensitivity pneumonitis. • The clinical setting (outpatient versus inpatient) will alter the order of the differential diagnosis. - Abstract: Purpose: The purpose of our study was to determine the relative frequencies of causes of widespread ground-glass opacity (GGO) in an unselected, consecutive patient population and to identify any associated imaging findings that can narrow or reorganize the differential. Materials and methods: The study was approved by the center's IRB and is HIPPA compliant. Cases with widespread GGO in the radiology report were identified by searching the Radiology Information System. Medical records and CT scan examinations were reviewed for the causes of widespread GGO. Associations between a less dominant imaging finding and a particular diagnosis were analyzed with the chi square test. Our study group consisted of 234 examinations with 124 women and 110 men and a mean age of 53.7 years. Results: A cause was established in 204 (87.2%) cases. Hydrostatic pulmonary edema was most common with 131 cases (56%). Interstitial lung diseases (ILD) were the next most common, most often hypersensitivity pneumonitis (HP) (n = 12, 5%) and connective tissue disease related ILD (n = 7, 3%). Infection accounted for 5% (12 cases). A few miscellaneous diseases accounted for 5 cases (2.1%). The combination of septal thickening and pleural effusions had a specificity of 0.91 for hydrostatic pulmonary edema (P < .001) while centrilobular nodules and air trapping had a specificity of 1.0 for HP. In 24 (10.2%) patients, increased opacification from expiration was incorrectly interpreted as representing widespread ground glass opacity. The relative frequency of disease dramatically changed according to the setting. In the inpatient setting, diffuse

  13. Tables of phase functions, opacities, albedos, equilibrium temperatures, and radiative accelerations of dust grains in exoplanets

    CERN Document Server

    Budaj, Jan; Salmeron, Raquel; Hubeny, Ivan

    2015-01-01

    There has been growing observational evidence for the presence of condensates in the atmospheres and/or comet-like tails of extrasolar planets. As a result, systematic and homogeneous tables of dust properties are useful in order to facilitate further observational and theoretical studies. In this paper we present calculations and analysis of non-isotropic phase functions, asymmetry parameter (mean cosine of the scattering angle), absorption and scattering opacities, single scattering albedos, equilibrium temperatures, and radiative accelerations of dust grains relevant for extrasolar planets. Our assumptions include spherical grain shape, Deirmendjian particle size distribution, and Mie theory. We consider several species: corundum/alumina, iron, olivines with 0% and 50% iron content, pyroxenes with 0%, 20% and 60% iron content, carbon at two different temperatures, water ice, liquid water, and ammonia. The presented tables cover the wavelength range of 0.2 to 500 micron and modal particle radii from 0.01 mi...

  14. Liquid refractive index sensing independent of opacity using an optofluidic sensor based on diffraction

    CERN Document Server

    Xu, Zhida

    2014-01-01

    We have implemented a multi-functional optofluidic sensor that can monitor changes in the refractive index and pressure of biofluid simultaneously and can detect free-solution molecular interaction in-situ. In this paper, we demonstrate two major improvements of this sensor proven by both simulation and experiments. One improvement is the broader measurement range of refractive index by making the diffraction grating with high-index polymer. The other improvement is the separation of refractive index sensing from opacity sensing by using the relative power ratio of diffraction orders. This simple, compact and low-cost multi-functional optofluidic sensor has the potential to be used for in-situ biofluid monitoring.

  15. Calibration of X-ray spectrometers for opacity experiments at the Orion laser facility (invited)

    Science.gov (United States)

    Bentley, C.; Allan, P.; Brent, K.; Bruce, N.; Hoarty, D.; Meadowcroft, A.; Percival, J.; Opie, C.

    2016-11-01

    Accurately calibrated and characterised x-ray diagnostics are a key requirement in the fielding of experiments on the Orion laser where absolute measurements of x-ray emission are used to underpin the validity of models of emissivity and opacity. Diffraction crystals are used in spectrometers on Orion to record the dispersed spectral features emitted by the laser produced plasma to obtain a measurement of the plasma conditions. The ability to undertake diffraction crystal calibrations supports the successful outcome of these Orion experiments. This paper details the design and commissioning of a system to undertake these calibrations in the energy range 2.0 keV to approximately 8.5 keV. Improvements to the design are detailed which will extend the commissioned range of energies to below 1 keV.

  16. All-sky Relative Opacity Mapping Using Night Time Panoramic Images

    CERN Document Server

    Shamir, L; Shamir, Lior; Nemiroff, Roberj J.

    2005-01-01

    An all-sky cloud monitoring system that generates relative opacity maps over many of the world's premier astronomical observatories is described. Photometric measurements of numerous background stars are combined with simultaneous sky brightness measurements to differentiate thin clouds from sky glow sources such as air glow and zodiacal light. The system takes a continuous pipeline of all-sky images, and compares them to canonical images taken on other nights at the same sidereal time. Data interpolation then yields transmission maps covering almost the entire sky. An implementation of this system is currently operating through the Night Sky Live network of CONCAM3s located at Cerro Pachon (Chile), Mauna Kea (Hawaii), Haleakala (Hawaii), SALT (South Africa) and the Canary Islands (Northwestern Africa).

  17. Ground-Glass Opacity Lung Nodules in the Era of Lung Cancer CT Screening

    DEFF Research Database (Denmark)

    Pedersen, Jesper Holst; Saghir, Zaigham; Winkler Wille, Mathilde Marie

    2016-01-01

    The advent of computed tomography screening for lung cancer will increase the incidence of ground-glass opacity (GGO) nodules detected and referred for diagnostic evaluation and management. GGO nodules remain a diagnostic challenge; therefore, a more systematic approach is necessary to ensure......, the National Comprehensive Cancer Network, and the British Thoracic Society. In addition, we discuss the management and follow-up of GGO nodules in the light of experience from screening trials. Minimally invasive tissue biopsies and the marking of GGO nodules for surgery are new and rapidly developing fields...... that will yield improvements in both diagnosis and treatment. The standard-of-care surgical treatment of early lung cancer is still minimally invasive lobectomy with systematic lymph node dissection. However, recent research has shown that some GGO lesions may be treated with sublobar resections; these findings...

  18. Intensity enhancement of O VI ultraviolet emission lines in solar spectra due to opacity

    CERN Document Server

    Keenan, F P; Madjarska, M S; Rose, S J; Bowler, L A; Britton, J; McCrink, L; Mathioudakis, M

    2014-01-01

    Opacity is a property of many plasmas, and it is normally expected that if an emission line in a plasma becomes optically thick, its intensity ratio to that of another transition that remains optically thin should decrease. However, radiative transfer calculations undertaken both by ourselves and others predict that under certain conditions the intensity ratio of an optically thick to thin line can show an increase over the optically thin value, indicating an enhancement in the former. These conditions include the geometry of the emitting plasma and its orientation to the observer. A similar effect can take place between lines of differing optical depth. Previous observational studies have focused on stellar point sources, and here we investigate the spatially-resolved solar atmosphere using measurements of the I(1032 A)/I(1038 A) intensity ratio of O VI in several regions obtained with the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) instrument on board the Solar and Heliospheric Observatory (...

  19. Total power millimeter-wave spectrometer for measurements of dust opacity at cryogenic temperatures.

    Science.gov (United States)

    Potapov, Alexey; Lewen, Frank; Mutschke, Harald; Mohr, Pierre; Schlemmer, Stephan

    2014-07-01

    A highly sensitive total power millimeter-wave spectrometer has been built to investigate the opacity of important interstellar-dust analogues in the 10-300 K temperature range. The key elements of the spectrometer are a frequency agile synthesizer followed by a microwave amplifier and a subsequent frequency multiplier. In a first step, the frequency range of 72-120 GHz is covered by the spectrometer, and a room temperature Schottky detector is employed as a detector. A newly developed two channel (sample/reference) copper sample holder is cryogenically cooled for the 10-300 K range. Here we present the technical details of the spectrometer including examples of the obtained results. The analysis of these results will be published elsewhere.

  20. Lethality Index 2008-2014: Less shootings, same lethality, more opacity

    Directory of Open Access Journals (Sweden)

    Carlos Silva Forné

    2017-07-01

    Full Text Available This article evaluates the use of lethal force by Mexican federal security forces during shootings with presumed members of organized crime from 2008-2014. The authors use official data and press reports on deaths and wounded in shootings to construct indicators such as the number of dead civilians over the number of dead officials from the federal security forces and the number of dead civilians over the number of wounded civilians. In a context where certain factors that contribute to an excessive use of force become more common, the results of the study show a growing use of lethal force. This raises questions over the possible excessive use of lethal force as a normal or systematic practice. The study also shows a growing context of opacity in the infor­mation available to evaluate the use of lethal force and the general lack of a legal framework to regulate the use of lethal force in Mexico.

  1. Dynamical Opacity-Sampling Models of Mira Variables. I: Modelling Description and Analysis of Approximations

    CERN Document Server

    Ireland, M J; Wood, P R

    2008-01-01

    We describe the Cool Opacity-sampling Dynamic EXtended (CODEX) atmosphere models of Mira variable stars, and examine in detail the physical and numerical approximations that go in to the model creation. The CODEX atmospheric models are obtained by computing the temperature and the chemical and radiative states of the atmospheric layers, assuming gas pressure and velocity profiles from Mira pulsation models, which extend from near the H-burning shell to the outer layers of the atmosphere. Although the code uses the approximation of Local Thermodynamic Equilibrium (LTE) and a grey approximation in the dynamical atmosphere code, many key observable quantities, such as infrared diameters and low-resolution spectra, are predicted robustly in spite of these approximations. We show that in visible light, radiation from Mira variables is dominated by fluorescence scattering processes, and that the LTE approximation likely under-predicts visible-band fluxes by a factor of two.

  2. 1st oPAC Topical Workshop: Grand Challenges in Accelerator Optimisation

    CERN Document Server

    2013-01-01

    Accelerators are key instruments for fundamental research, health and industry applications. International collaboration is very important for their continued optimisation. To address this oPAC is organising this two-day international workshop on Grand Challenges in Accelerator Optimisation. The workshop will provide an overview of the current state of the art in beam physics, numerical simulations and beam instrumentation and highlight existing limitations. It will discuss research and development being undertaken and ambitions to further improve the performance of existing and future facilities. In addition to invited talks, there will be industry displays and a special seminar covering recent LHC discoveries. All participants will have an opportunity to contribute a poster.

  3. The Opacity of Russian-Ukrainian Energy Relations; Russie-Ukraine: opacite des reseaux energetiques

    Energy Technology Data Exchange (ETDEWEB)

    Dubien, A.

    2007-07-01

    Energy issues lie at the heart of Ukraine's economic, political and strategic challenges. A year after the 'orange revolution', the 'gas war' served to highlight the country's vulnerable position, being 80% dependent on imports of gas and having the world's most energy hungry economy. The 2005 crisis also highlighted the extreme opacity of the country's bilateral relations with Russia, which are governed as much by the interests surrounding Gazprom's relations as by those of the state. Yanukovich's return to power in the summer of 2006 coincided with a relative appeasement of relations with Moscow and a new division of spheres of influence in the Ukrainian energy sector. (author)

  4. Conceptual design of initial opacity experiments on the national ignition facility

    Energy Technology Data Exchange (ETDEWEB)

    Heeter, R.  F.; Bailey, J.  E.; Craxton, R.  S.; DeVolder, B.  G.; Dodd, E.  S.; Garcia, E.  M.; Huffman, E.  J.; Iglesias, C.  A.; King, J.  A.; Kline, J.  L.; Liedahl, D.  A.; McKenty, P.  W.; Opachich, Y.  P.; Rochau, G.  A.; Ross, P.  W.; Schneider, M.  B.; Sherrill, M.  E.; Wilson, B.  G.; Zhang, R.; Perry, T.  S.

    2017-01-09

    Accurate models of X-ray absorption and re-emission in partly stripped ions are necessary to calculate the structure of stars, the performance of hohlraums for inertial confinement fusion and many other systems in high-energy-density plasma physics. Despite theoretical progress, a persistent discrepancy exists with recent experiments at the Sandia Z facility studying iron in conditions characteristic of the solar radiative–convective transition region. The increased iron opacity measured at Z could help resolve a longstanding issue with the standard solar model, but requires a radical departure for opacity theory. To replicate the Z measurements, an opacity experiment has been designed for the National Facility (NIF). The design uses established techniques scaled to NIF. A laser-heated hohlraum will produce X-ray-heated uniform iron plasmas in local thermodynamic equilibrium (LTE) at temperatures${\\geqslant}150$ eV and electron densities${\\geqslant}7\\times 10^{21}~\\text{cm}^{-3}$. The iron will be probed using continuum X-rays emitted in a${\\sim}200$ ps,${\\sim}200~\\unicode[STIX]{x03BC}\\text{m}$diameter source from a 2 mm diameter polystyrene (CH) capsule implosion. In this design

  5. Heating of the Solar Corona by Alfven Waves: Self-Induced Opacity

    CERN Document Server

    Zahariev, N I

    2011-01-01

    There have been derived equations describing the static distributions of temperature and wind velocity at the transition region within the framework of the magnetohydrodynamics (MHD) of fully ionized hydrogen plasma . We have also calculated the width of the transition between the chromosphere and corona as a self-induced opacity of the high-frequency Alfven waves (AWs). The domain wall is a direct consequence of the self-consistent MHD treatment of AWs propagation. We predict considerable spectral density of the high-frequency AWs in the photosphere. The idea that Alfven waves might heat the solar corona belong to Alfven - we simply derived the corresponding MHD equations. The comparison of the solutions to those equations with the observational/measured data will be crucial for revealing the heating mechanism. The analysis of those solutions will explain how Alfven waves brick unto the corona and dissipate their energy there.

  6. Satellite and Opacity Effects on Resonance Line Shapes Produced from Short-Pulse Laser Heated Foils

    Energy Technology Data Exchange (ETDEWEB)

    Shepherd, R; Audebert, P; Chen, H-K; Fournier, K B; Peyreusse, O; Moon, S; Lee, R W; Price, D; Klein, L; Gauthier, J C; Springer, P

    2002-12-03

    We measure the He-like, time-resolved emission from thin foils consisting of 250 {angstrom} of carbon-250 {angstrom} of aluminum and 500 {angstrom} aluminum illuminated with a 150 fs laser pulse at an intensity of 1 x 10{sup 19} W/cm{sup 2}. Dielectronic satellite contributions to the 1s{sup 2}-1s2p({sup 1}P), 1s{sup 2}-1s3p({sup 1}P), and 1s{sup 2}1s4p({sup 1}P) line intensities are modeled using the configuration averaged code AVERROES and is found to be significant for all three resonance lines. The contribution of opacity broadening is inferred from the data and found to be significant only in the 1s{sup 2}-1s2p({sup 1}P).

  7. Mid-Infrared Mapping of Jupiter's Temperatures, Aerosol Opacity and Chemical Distributions with IRTF/TEXES

    CERN Document Server

    Fletcher, L N; Orton, G S; Sinclair, J A; Giles, R S; Irwin, P G J; Encrenaz, T

    2016-01-01

    Global maps of Jupiter's atmospheric temperatures, gaseous composition and aerosol opacity are derived from a programme of 5-20 $\\mu$m mid-infrared spectroscopic observations using the Texas Echelon Cross Echelle Spectrograph (TEXES) on NASA's Infrared Telescope Facility (IRTF). Image cubes from December 2014 in eight spectral channels, with spectral resolutions of $R\\sim2000-12000$ and spatial resolutions of $2-4^\\circ$ latitude, are inverted to generate 3D maps of tropospheric and stratospheric temperatures, 2D maps of upper tropospheric aerosols, phosphine and ammonia, and 2D maps of stratospheric ethane and acetylene. The results are compared to a re-analysis of Cassini Composite Infrared Spectrometer (CIRS) observations acquired during Cassini's closest approach to Jupiter in December 2000, demonstrating that this new archive of ground-based mapping spectroscopy can match and surpass the quality of previous investigations, and will permit future studies of Jupiter's evolving atmosphere. We identify mid-i...

  8. Ground-Glass Opacity Lung Nodules in the Era of Lung Cancer CT Screening

    DEFF Research Database (Denmark)

    Pedersen, Jesper Holst; Saghir, Zaigham; Wille, Mathilde Marie Winkler

    2016-01-01

    The advent of computed tomography screening for lung cancer will increase the incidence of ground-glass opacity (GGO) nodules detected and referred for diagnostic evaluation and management. GGO nodules remain a diagnostic challenge; therefore, a more systematic approach is necessary to ensure...... correct diagnosis and optimal management. Here we present the latest advances in the radiologic imaging and pathology of GGO nodules, demonstrating that radiologic features are increasingly predictive of the pathology of GGO nodules. We review the current guidelines from the Fleischner Society......, the National Comprehensive Cancer Network, and the British Thoracic Society. In addition, we discuss the management and follow-up of GGO nodules in the light of experience from screening trials. Minimally invasive tissue biopsies and the marking of GGO nodules for surgery are new and rapidly developing fields...

  9. The Next Generation Library Catalog: A Comparative Study of the OPACs of Koha, Evergreen, and Voyager

    Directory of Open Access Journals (Sweden)

    Sharon Q. Yang

    2010-09-01

    Full Text Available Open source has been the center of attention in the library world for the past several years. Koha and Evergreen are the two major open-source integrated library systems (ILSs, and they continue to grow in maturity and popularity. The question remains as to how much we have achieved in open-source development toward the next-generation catalog compared to commercial systems. Little has been written in the library literature to answer this question. This paper intends to answer this question by comparing  the next-generation features of the OPACs of two open-source ILSs (Koha and Evergreen and one proprietary ILS (Voyager’s WebVoyage.

  10. Lens Opacity and Hydrogen Sulfide in a New Zealand Geothermal Area.

    Science.gov (United States)

    Bates, Michael N; Bailey, Ian L; DiMartino, Robert B; Pope, Karl; Crane, Julian; Garrett, Nick

    2017-04-01

    Hydrogen sulfide (H2S) is a highly toxic gas with well-established, acute irritation effects on the eye. The population of Rotorua, New Zealand, sited on an active geothermal field, has some of the highest ambient H2S exposures in the world. Evidence from ecological studies in Rotorua has suggested that H2S is associated with cataract. The purpose of the present study was, using more detailed exposure characterization, clinical examinations, and anterior eye photography, to more directly investigate this previously reported association. Enrolled were 1637 adults, ages 18 to 65, from a comprehensive Rotorua primary care medical register. Patients underwent a comprehensive ophthalmic examination, including pupillary dilation and lens photography to capture evidence of any nuclear opacity, nuclear color, and cortical and posterior subcapsular opacity. Photographs were scored for all four outcomes on the LOCS III scale with decimalized interpolation between the exemplars. H2S exposure for up to the last 30 years was estimated based on networks of passive samplers set out across Rotorua and knowledge of residential, workplace, and school locations over the 30 years. Data analysis using linear and logistic regression examined associations between the degree of opacification and nuclear color or cataract (defined as a LOCS III score ≥2.0) in relation to H2S exposure. No associations were found between estimated H2S exposures and any of the four ophthalmic outcome measures. Overall, results were generally reassuring. They provided no evidence that H2S exposure at the levels found in Rotorua is associated with cataract. The previously found association between cataract and H2S exposure in the Rotorua population seems likely to be attributable to the limitations of the ecological study design. These results cannot rule out the possibility of an association with cataract at higher levels of H2S exposure.

  11. MINIMUM CORE MASSES FOR GIANT PLANET FORMATION WITH REALISTIC EQUATIONS OF STATE AND OPACITIES

    Energy Technology Data Exchange (ETDEWEB)

    Piso, Ana-Maria A.; Murray-Clay, Ruth A. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Youdin, Andrew N., E-mail: apiso@cfa.harvard.edu [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2015-02-20

    Giant planet formation by core accretion requires a core that is sufficiently massive to trigger runaway gas accretion in less than the typical lifetime of protoplanetary disks. We explore how the minimum required core mass, M {sub crit}, depends on a non-ideal equation of state (EOS) and on opacity changes due to grain growth across a range of stellocentric distances from 5-100 AU. This minimum M {sub crit} applies when planetesimal accretion does not substantially heat the atmosphere. Compared to an ideal gas polytrope, the inclusion of molecular hydrogen (H{sub 2}) dissociation and variable occupation of H{sub 2} rotational states increases M {sub crit}. Specifically, M {sub crit} increases by a factor of ∼2 if the H{sub 2} spin isomers, ortho- and parahydrogen, are in thermal equilibrium, and by a factor of ∼2-4 if the ortho-to-para ratio is fixed at 3:1. Lower opacities due to grain growth reduce M {sub crit}. For a standard disk model around a Solar mass star, we calculate M {sub crit} ∼ 8 M {sub ⊕} at 5 AU, decreasing to ∼5 M {sub ⊕} at 100 AU, for a realistic EOS with an equilibrium ortho-to-para ratio and for grain growth to centimeter-sizes. If grain coagulation is taken into account, M {sub crit} may further reduce by up to one order of magnitude. These results for the minimum critical core mass are useful for the interpretation of surveys that find exoplanets at a range of orbital distances.

  12. Efficient blood flow visualization using flowline extraction and opacity modulation based on vascular structure analysis.

    Science.gov (United States)

    Kwon, Ohjae; Lee, Jeongjin; Kim, Bohyoung; Shin, Juneseuk; Shin, Yeong-Gil

    2017-03-01

    With the recent advances regarding the acquisition and simulation of blood flow data, blood flow visualization has been widely used in medical imaging for the diagnosis and treatment of pathological vessels. In this paper, we present a novel method for the visualization of the blood flow in vascular structures. The vessel inlet or outlet is first identified using the orthogonality metric between the normal vectors of the flow velocity and vessel surface. Then, seed points are generated on the identified inlet or outlet by Poisson disk sampling. Therefore, it is possible to achieve the automatic seeding that leads to a consistent and faster flow depiction by skipping the manual location of a seeding plane for the initiation of the line integration. In addition, the early terminated line integration in the thin curved vessels is resolved through the adaptive application of the tracing direction that is based on the flow direction at each seed point. Based on the observation that blood flow usually follows the vessel track, the representative flowline for each branch is defined by the vessel centerline. Then, the flowlines are rendered through an opacity assignment according to the similarity between their shape and the vessel centerline. Therefore, the flowlines that are similar to the vessel centerline are shown transparently, while the different ones are shown opaquely. Accordingly, the opacity modulation method enables the flowlines with an unusual flow pattern to appear more noticeable, while the visual clutter and line occlusion are minimized. Finally, Hue-Saturation-Value color coding is employed for the simultaneous exhibition of flow attributes such as local speed and residence time. The experiment results show that the proposed technique is suitable for the depiction of the blood flow in vascular structures. The proposed approach is applicable to many kinds of tubular structures with embedded flow information.

  13. Effect of resin shades on opacity of ceramic veneers and polymerization efficiency through ceramics.

    Science.gov (United States)

    Öztürk, Elif; Chiang, Yu-Chih; Coşgun, Erdal; Bolay, Şükran; Hickel, Reinhard; Ilie, Nicoleta

    2013-11-01

    The aim of this study was to assess the effect of different resin cement shades on the opacity and color difference of ceramics and to determine the polymerization efficiency of the resin cement at different shades after curing through ceramics. Two different ceramics (IPS e.max Press and IPS Empress(®)CAD, Ivoclar Vivadent) were used for this study. A light-cured veneer luting resin (Variolink Veneer, Ivoclar Vivadent) in four different shades of HV+1, HV+3, LV-1, and LV-3 was used for the colorimetric measurements. The color and spectral reflectance of the ceramics were measured according to the CIELab color scale relative to the standard illuminant D65 on a reflection spectrophotometer (ColorEye7000A, USA). Color differences (ΔE values) and the contrast ratios (CR) of the different groups of samples were calculated. In order to analyse the polymerization efficiency of the resin cements, the micromechanical properties of the resins were measured with an automatic microhardness indenter (Fisherscope H100C, Germany). The results were analysed using one-way ANOVA and Tukey's HSD post hoc tests (SPSS 18.0). The one-way ANOVA test showed that the values of ΔE and CR of the different specimen groups were significantly different (p<0.05). Group 1 (20.7 ± 0.5) (IPS-CAD without resin cement) exhibited the highest and group 10 (14.8 ± 0.5) (e.max:HV+3) exhibited the lowest ΔE value. Significant differences in the micromechanical properties were identified among the tested resin cements in different shades (p<0.05). Resin cement shade is an important factor for the opacity of a restoration. Furthermore, the resin shade affects the micromechanical properties of the underlying resin cement. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. The extragalactic background light revisited and the cosmic photon-photon opacity

    Science.gov (United States)

    Franceschini, Alberto; Rodighiero, Giulia

    2017-07-01

    Context. In addition to its relevant astrophysical and cosmological significance, the extragalactic background light (EBL) is a fundamental source of opacity for cosmic high energy photons, as well as a limitation for the propagation of high-energy particles in the Universe. Aims: We review our previously published determinations of the EBL photon density in the Universe and its evolution with cosmic time, in the light of recent surveys of IR sources at long wavelengths. Methods: We exploit deep survey observations by the Herschel Space Observatory and the Spitzer telescope, matched to optical and near-IR photometric and spectroscopic data, to re-estimate number counts and luminosity functions longwards of a few microns, and the contribution of resolved sources to the EBL. Results: These new data indicate slightly lower photon densities in the mid- and far-infrared and sub-millimeter compared to previous determinations. This implies slightly lower cosmic opacity for photon-photon interactions. Conclusions: The new data do not modify previously published EBL modeling in the UV-optical and near-IR up to several microns, while reducing the photon density at longer wavelengths. This improved model of the EBL alleviates some tension that had emerged in the interpretation of the highest-energy TeV observations of local blazars, reducing the case for new physics beyond the standard model (like violations of the Lorenz Invariance, LIV, at the highest particle energies), or for exotic astrophysics, that had sometimes been called for to explain it. Applications of this improved EBL model on current data are considered, as well as perspectives for future instrumentation, the Cherenkov Telescope Array (CTA) in particular.

  15. Effect of a High Opacity on the Light Curves of Radioactively Powered Transients from Compact Object Mergers

    CERN Document Server

    Barnes, Jennifer

    2013-01-01

    The coalescence of compact objects are a promising astrophysical sources of gravitational wave (GW) signals. The ejection of r-process material from such mergers may lead to a radioactively-powered electromagnetic counterpart which, if discovered, would enhance the science return of a GW detection. As very little is known about the optical properties of heavy r-process elements, previous light curve models have adopted opacities similar to those of iron group elements. Here we report that the presence of heavier elements, particularly the lanthanides, increase the ejecta opacity by several orders of magnitude. We include these higher opacities in time dependent, multi-wavelength radiative transport calculations to predict the broadband light curves of one-dimensional models over a range of parameters (ejecta masses from 0.001 to 0.1 solar masses and velocities from 0.1 to 0.3c). We find that the higher opacities lead to much longer duration light curves which can last a week or more. The emission is shifted t...

  16. 40 CFR 60.1450 - How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?

    Science.gov (United States)

    2010-07-01

    ... curtain incinerators that burn 100 percent yard waste? 60.1450 Section 60.1450 Protection of Environment... Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1450 How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste? (a) Use EPA Reference Method 9 in appendix A...

  17. 40 CFR 60.1925 - How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste?

    Science.gov (United States)

    2010-07-01

    ... curtain incinerators that burn 100 percent yard waste? 60.1925 Section 60.1925 Protection of Environment... or Before August 30, 1999 Model Rule-Air Curtain Incinerators That Burn 100 Percent Yard Waste § 60.1925 How must I monitor opacity for air curtain incinerators that burn 100 percent yard waste? (a)...

  18. Interpretation of the BRITE oscillation data of the hybrid pulsator ν Eridani: a call for the modification of stellar opacities

    Science.gov (United States)

    Daszyńska-Daszkiewicz, J.; Pamyatnykh, A. A.; Walczak, P.; Colgan, J.; Fontes, C. J.; Kilcrease, D. P.

    2017-04-01

    The analysis of the BRIght Target Explorer (BRITE) oscillation spectrum of the main-sequence early B-type star ν Eridani is presented. Only models with the modified mean opacity profile can account for the observed frequency ranges as well as for the values of some individual frequencies. The number of the κ-modified seismic models is constrained by the non-adiabatic parameter f, which is very sensitive to the opacity changes in the subphotospheric layers, where the pulsations are driven. We present an example of the model that satisfies all the above conditions. It seems that the OPLIB opacities are preferred over those from the OPAL and OP projects. Moreover, we discuss additional consequences of the opacity modification, namely, an enhancement of the efficiency of convection in the Z bump as well as an occurrence of close radial modes which is a kind of avoided-crossing phenomenon common for non-radial modes in standard main-sequence models.

  19. The effect of including molecular opacities of variable composition on the evolution of intermediate-mass AGB stars

    CERN Document Server

    Fishlock, C K; Stancliffe, R J

    2013-01-01

    Calculations from stellar evolutionary models of low- and intermediate-mass asymptotic giant branch (AGB) stars provide predictions of elemental abundances and yields for comparison to observations. However, there are many uncertainties that reduce the accuracy of these predictions. One such uncertainty involves the treatment of low-temperature molecular opacities that account for the surface abundance variations of C, N, and O. A number of prior calculations of intermediate-mass AGB stellar models that incorporate both efficient third dredge-up and hot bottom burning include a molecular opacity treatment which does not consider the depletion of C and O due to hot bottom burning. Here we update the molecular opacity treatment and investigate the effect of this improvement on calculations of intermediate-mass AGB stellar models. We perform tests on two masses, 5 M$_{\\odot}$ and 6 M$_{\\odot}$, and two metallicities, $Z~=~0.001$ and $Z~=~0.02$, to quantify the variations between two opacity treatments. We find t...

  20. Study of the radio-opacity of base and liner dental materials using a digital radiography system.

    Science.gov (United States)

    Lachowski, K M; Botta, S B; Lascala, C A; Matos, A B; Sobral, M A P

    2013-01-01

    This study investigated the radio-opacity of commercially available glass ionomer cements (GICs), flowable resin composites (FRCs) and calcium hydroxide cements (CHCs) and compared this with the radio-opacity of enamel, dentine and aluminium stepwedge. 16 GICs, 8 FRCs and 4 CHCs were analysed. Three sets of three samples were prepared: 1 mm, 2 mm and 3 mm thickness for GIC and FRC and 1 mm thickness for CHC. Specimens of enamel and dentine with the same thicknesses were obtained. As a control, an aluminium stepwedge was used. Radiographs were taken with a digital Kodak RVG 5000 (0.32 s, 30 cm). The images were analysed using the Image Tool(®) program (v. 2.00; The University of Texas Health Science Center, San Antonio, TV) to obtain the mean grey values. Analysis of variance was used to investigate the significance of differences among the groups. For pairwise comparisons, the Tukey test was applied (p < 0.05). The GICs Ionomaster (Wilcos, Petrópolis, Brazil), Maxxion (FGM, Joinville, Brazil), Bioglass R (Biodinâmica, Ibiporã, Brazil), Bioglass F (Biodinâmica), Vidrion R (SS White, Rio de Janerio, Brazil) and Vidrion F (SS White), presented radio-opacity lower than that of dentine. All FRCs and CHCs studied showed radio-opacity higher than that of dentine. Vitro Fil (DFL, Rio de Janeiro, Brazil), Magic Glass (Vigodent, Rio de Janeiro, Brazil), Vitrebond (3M, Sumaré SP, Brazil), Riva Self Cure (SDI, Victoria, Australia), Riva Light Cure (SDI), Fill Magic (Vigodent), Opallis (FGM, Joinville, Brazil), Surefil SDR (Dentsply, Milford, DE), Tetric N (Ivoclar Vivadent, Schaan, Lichtenstein), Tetric (Ivoclar Vivadent), Hydro C (Dentsply, Petrópolis, Brazil), Hydcal (Technew, Madalena, Portugal) and Liner (Vigodent) showed radio-opacity similar to or greater than that of enamel for all thicknesses. The increased thickness of the materials studied increases their radio-opacity. Some commercially available GICs used as a base and liner for restorations

  1. Preoperative computed tomography-guided percutaneous localization of ground glass pulmonary opacity with polylactic acid injection.

    Science.gov (United States)

    Hu, Mu; Zhi, Xiuyi; Zhang, Jian

    2015-07-01

    Localization of a ground glass nodule is a difficult challenge for thoracic surgeons, especially for ground glass opacities (GGOs) less than 10 mm in diameter. In this study we implement a new method for preoperative localization of pulmonary (GGOs). From October 2013 to December 2014, computed tomography-guided percutaneous polylactic acid injection localizations were performed for five pulmonary nodules in five patients (2 men and 3 women; mean age, 59.8 years; range, 54-65 years). The injection was feasible in all patients and the localization effect was excellent. The total procedure duration was 12.6 minutes (range; 10-15) and the volume of polylactic acid injected was 0.38 mL. The wedge resections were easily and successfully performed in all five cases. The cutting margin was no less than 2 cm from the lesion. This technique is promising for the determination of GGO location in thoracoscopic surgery for wedge resection.

  2. Opacity and conductivity measurements in noble gases at conditions of planetary and stellar interiors.

    Science.gov (United States)

    McWilliams, R Stewart; Dalton, D Allen; Konôpková, Zuzana; Mahmood, Mohammad F; Goncharov, Alexander F

    2015-06-30

    The noble gases are elements of broad importance across science and technology and are primary constituents of planetary and stellar atmospheres, where they segregate into droplets or layers that affect the thermal, chemical, and structural evolution of their host body. We have measured the optical properties of noble gases at relevant high pressures and temperatures in the laser-heated diamond anvil cell, observing insulator-to-conductor transformations in dense helium, neon, argon, and xenon at 4,000-15,000 K and pressures of 15-52 GPa. The thermal activation and frequency dependence of conduction reveal an optical character dominated by electrons of low mobility, as in an amorphous semiconductor or poor metal, rather than free electrons as is often assumed for such wide band gap insulators at high temperatures. White dwarf stars having helium outer atmospheres cool slower and may have different color than if atmospheric opacity were controlled by free electrons. Helium rain in Jupiter and Saturn becomes conducting at conditions well correlated with its increased solubility in metallic hydrogen, whereas a deep layer of insulating neon may inhibit core erosion in Saturn.

  3. ANALYSIS OF THE RADIO-OPACITY OF A SELF-ETCH ADHESIVE

    Directory of Open Access Journals (Sweden)

    Mona Ionaş

    2012-12-01

    Full Text Available Introduction. At present, self-etch adhesive systems are employed on large scale in the offices of dental medicine due to their simple application technique. Their radioopacity is important for the identification of this material in paraclinical examinations. Scope. The study describes a technique of radioopacity analysis on a self-etching type adhesive material. Materials and method. Class V cavities have been made on the teeth extracted from orthodontic causes. The dental adhesive was applied on the surface of the cavities, followed by their obturation with a composite material. The teeth were sliced, radiographed, the resulting digital images being analyzed with a specialized software. Results and discussion. The radio-opacity of this adhesive system, lower than that of the enamel, varies, comparatively with that of dentin. Conclusions. Having no filling, the here discussed adhesive system has a relative optical density slightly lower than that of dentin, which makes difficult its radiological identification. Consequently, some problems of differential diagnosis may appear, with the marginal secondary caries or with caries recurrence

  4. Thermonuclear Bursts with Short Recurrence Times from Neutron Stars Explained by Opacity-driven Convection

    Science.gov (United States)

    Keek, L.; Heger, A.

    2017-06-01

    Thermonuclear flashes of hydrogen and helium accreted onto neutron stars produce the frequently observed Type I X-ray bursts. It is the current paradigm that almost all material burns in a burst, after which it takes hours to accumulate fresh fuel for the next burst. In rare cases, however, bursts are observed with recurrence times as short as minutes. We present the first one-dimensional multi-zone simulations that reproduce this phenomenon. Bursts that ignite in a relatively hot neutron star envelope leave a substantial fraction of the fuel unburned at shallow depths. In the wake of the burst, convective mixing events driven by opacity bring this fuel down to the ignition depth on the observed timescale of minutes. There, unburned hydrogen mixes with the metal-rich ashes, igniting to produce a subsequent burst. We find burst pairs and triplets, similar to the observed instances. Our simulations reproduce the observed fraction of bursts with short waiting times of ∼30%, and demonstrate that short recurrence time bursts are typically less bright and of shorter duration.

  5. Molecular opacities for low-mass metal-poor AGB stars undergoing the Third Dredge Up

    CERN Document Server

    Cristallo, S; Lederer, M T; Aringer, B

    2007-01-01

    The concomitant overabundances of C, N and s-process elements are commonly ascribed to the complex interplay of nucleosynthesis, mixing and mass loss taking place in Asymptotic Giant Branch stars. At low metallicity, the enhancement of C and/or N may be up to 1000 times larger than the original iron content and significantly affects the stellar structure and its evolution. For this reason, the interpretation of the already available and still growing amount of data concerning C-rich metal-poor stars belonging to our Galaxy as well as to dwarf spheroidal galaxies would require reliable AGB stellar models for low and very low metallicities. In this paper we address the question of calculation and use of appropriate opacity coefficients, which take into account the C enhancement caused by the third dredge up. A possible N enhancement, caused by the cool bottom process or by the engulfment of protons into the convective zone generated by a thermal pulse and the subsequent huge third dredge up, is also considered....

  6. CT characteristics of resolving ground-glass opacities in a lung cancer screening programme

    Energy Technology Data Exchange (ETDEWEB)

    Felix, L.; Serra-Tosio, G. [Clinique Universitaire de Radiologie et Imagerie Medicale, Universite Grenoble I, CHU Grenoble (France); Lantuejoul, S. [Departement d' anatomie Pathologique, Universite Grenoble I, CHU Grenoble (France); INSERM U823, A Bonniot Institute, La Tronche (France); Timsit, J.F. [INSERM U823, A Bonniot Institute, La Tronche (France); Moro-Sibilot, D.; Brambilla, C. [INSERM U823, A Bonniot Institute, La Tronche (France); Clinique Universitaire Pneumologique, Universite Grenoble I, CHU Grenoble (France); Ferretti, G.R., E-mail: gferretti@chu-grenoble.fr [Clinique Universitaire de Radiologie et Imagerie Medicale, Universite Grenoble I, CHU Grenoble (France); INSERM U823, A Bonniot Institute, La Tronche (France)

    2011-03-15

    Purpose: This study aimed at evaluating the computed tomography (CT) characteristics of resolving localized ground-glass opacities (GGOs) in a screening programme for lung cancer. Material and methods: 280 patients at high-risk for lung cancer (221 men, 59 women; mean age, 58.6 years), divided into four groups (lung cancer history (n = 83), head and neck cancer history (n = 63), symptomatic (n = 88) and asymptomatic (n = 46) cigarette smokers), were included in a prospective trial with annual low-dose CT for lung cancer screening. We retrospectively reviewed all localized GGOs, analyzed the CT characteristics on initial CT scans and changes during follow-up (median 29.1 months). Variables associated with resolution of GGOs were tested using chi-square or Mann-Whitney tests. Results: A total of 75 GGOs were detected in 37 patients; 54.7% were present at baseline and 45.3% appeared on annual CT. During follow-up, 56.2% persisted and 43.8% disappeared. The resolving localized GGOs were significantly more often lobular GGOs (p = 0.006), polygonal in shape (p = 0.02), mixed (p = 0.003) and larger (p < 0.0001) than non-resolving localized GGOs. Conclusion: Localized GGOs are frequent and many disappeared on follow-up. CT characteristics of resolving GGOs show significant differences compared to persistent ones. This study emphasizes the importance of short-term CT follow-up in subjects with localized GGOs.

  7. The role of scission in the perception of color and opacity.

    Science.gov (United States)

    Anderson, Barton L; Khang, Byung-Geun

    2010-05-01

    Recent work has shown that the decomposition of textures into a layered representation can induce striking percepts of inhomogeneous transparency and modulate the perceived lightness of achromatic textures (B. L. Anderson & J. Winawer, 2005, 2008). It was argued that two photo-geometric principles of perceptual organization were responsible for the percepts that arise in these images: a polarity constraint that determines the relative lightness of the two layers and a transmittance anchoring principle, which is responsible for determining portions of the scene that are in plain view. Here, we show that similar principles of perceptual organization underlie the decomposition of textures that vary only in chromaticity. We show that the chromatic contrast relationships along contours play a critical role in determining when chromatic scission occurs and in determining the perceived color and opacity of the layers that emerge when such conditions prevail. These findings provide evidence that a similar set of computational principles is used to decompose images into layers along both chromatic and achromatic axes of color space.

  8. Local Radiation Hydrodynamic Simulations of Massive Star Envelopes at the Iron Opacity Peak

    CERN Document Server

    Jiang, Yan-Fei; Bildsten, Lars; Quataert, Eliot; Blaes, Omer

    2015-01-01

    We perform three dimensional radiation hydrodynamic simulations of the structure and dynamics of radiation dominated envelopes of massive stars at the location of the iron opacity peak. One dimensional hydrostatic calculations predict an unstable density inversion at this location, whereas our simulations reveal a complex interplay of convective and radiative transport whose behavior depends on the ratio of the photon diffusion time to the dynamical time. The latter is set by the ratio of the optical depth per pressure scale height, $\\tau_0$, to $\\tau_c=c/c_g$, where $c_g \\approx$ 50 km/s is the isothermal sound speed in the gas alone. When $\\tau_0 \\gg \\tau_c$, convection reduces the radiation acceleration and removes the density inversion. The turbulent energy transport in the simulations agrees with mixing length theory and provides its first numerical calibration in the radiation dominated regime. When $\\tau_0 \\ll \\tau_c$, convection becomes inefficient and the turbulent energy transport is negligible. The...

  9. Influence of translucence/opacity and shade in the flexural strength of lithium disilicate ceramics

    Science.gov (United States)

    Santos, Mila Oliveira; do Amaral, Flávia Lucisano Botelho; França, Fabiana Mantovani Gomes; Basting, Roberta Tarkany

    2015-01-01

    Background: Lithium disilicate ceramic system consists of glass ceramic ingots with different grades of translucence which may influence its flexural strength. Aims: To assess the three-point flexural strength of the different lithium disilicate-based ceramic ingots (IPS e.max Press/Ivoclar Vivadent) with different levels of translucence and shade. Materials and Methods: Six groups of ceramic ingots were selected to represent different levels of translucence and shade (HTA1, HTBL2, LTA2, LTB2, MO2, and HO). They measured 25 mm × 5 mm × 2 mm (n = 10), according to ISO 6872 specifications, and tested on a universal test machine (EMIC). Statistical Analysis Used: A one-way analysis of variance (ANOVA) was used (α = 0.05). Results: The results (in MPa) were: HTA1 = 392.98; HTBL2 = 390.74; LTA2 = 390.46; LTB2 = 389.92; MO2 = 390.43; HO = 391.96. ANOVA showed no significant difference among groups (P = 0.1528). Conclusions: Different levels of translucence, opacity and shade of ingots did not affect their mechanical strength, and the use of these ceramics should be guided by the esthetic demands of each clinical situation. PMID:26430304

  10. The Minimum Mass for Opacity-Limited Fragmentation in Turbulent Cloud Cores

    CERN Document Server

    Whitworth, A P

    2004-01-01

    We present a new analysis of the minimum mass for star formation, based on opacity-limited fragmentation. Our analysis differs from the standard one, which considers hierarchical fragmentation of a 3-D medium, and yields $M_{_{\\rm MIN}} \\sim 0.007 {\\rm to} 0.010 M_\\odot$ for Population I star formation. Instead we analyse the more realistic situation in which there is one-shot fragmentation of a shock-compressed layer, of the sort which arises in turbulent star-forming clouds. In this situation, $M_{_{\\rm MIN}}$ can be smaller than $0.003 M_\\odot$. Our analysis is more stringent than the standard one in that (a) it requires fragments to have condensation timescales shorter than all competing mass scales, and (b) it takes into acount that a fragment grows by accretion whilst it is condensing out, and has to radiate away the energy dissipated in the associated accretion shock. It also accords with the recent detection, in young star clusters, of free-floating star-like objects having masses as low as $0.003 {\\r...

  11. Ultrafast opacity in borosilicate glass induced by picosecond bursts of laser-driven ions

    CERN Document Server

    Dromey, B; Adams, D; Prasad, R; Kakolee, K F; Stefanuik, R; Nersisyan, G; Sarri, G; Yeung, M; Ahmed, H; Doria, D; Dzelzainis, T; Jung, D; Kar, S; Marlow, D; Romagnani, L; Correa, A A; Dunne, P; Kohanoff, J; Schleife, A; Borghesi, M; Currell, F; Riley, D; Zepf, M; Lewis, C L S

    2014-01-01

    Direct investigation of ion-induced dynamics in matter on picosecond (ps, 10-12 s) timescales has been precluded to date by the relatively long nanosecond (ns, 10-9 s) scale ion pulses typically provided by radiofrequency accelerators1. By contrast, laser-driven ion accelerators provide bursts of ps duration2, but have yet to be applied to the study of ultrafast ion-induced transients in matter. We report on the evolution of an electron-hole plasma excited in borosilicate glass by such bursts. This is observed as an onset of opacity to synchronised optical probe radiation and is characterised by the 3.0 +/- 0.8 ps ion pump rise-time . The observed decay-time of 35 +/- 3 ps i.e. is in excellent agreement with modelling and reveals the rapidly evolving electron temperature (>10 3 K) and carrier number density (>10 17cm-3). This result demonstrates that ps laser accelerated ion bursts are directly applicable to investigating the ultrafast response of matter to ion interactions and, in particular, to ultrafast pu...

  12. HELIOS-K: An Ultrafast, Open-source Opacity Calculator for Radiative Transfer

    CERN Document Server

    Grimm, Simon L

    2015-01-01

    We present an ultrafast opacity calculator for application to exoplanetary atmospheres, which we name HELIOS-K. It takes a line list as an input, computes the shape of each spectral line (e.g., a Voigt profile) and provides an option for grouping an enormous number of lines into a manageable number of bins. We implement a combination of Algorithm 916 and Gauss-Hermite quadrature to compute the Voigt profile, write the code in CUDA and optimise the computation for graphics processing units (GPUs). We use the k-distribution method to reduce $\\sim 10^5$ to $10^8$ lines to $\\sim 10$ to $10^4$ wavenumber bins, which may then be used for radiative transfer, atmospheric retrieval and general circulation models. We demonstrate that the resampling of the k-distribution function, within each bin, is an insignificant source of error across a broad range of wavenumbers and column masses. By contrast, the choice of line-wing cutoff for the Voigt profile is a significant source of error and affects the value of the compute...

  13. A method for cloud detection and opacity classification based on ground based sky imagery

    Directory of Open Access Journals (Sweden)

    M. S. Ghonima

    2012-07-01

    Full Text Available Digital images of the sky obtained using a total sky imager (TSI are classified pixel by pixel into clear sky, optically thin and optically thick clouds. A new classification algorithm was developed that compares the pixel red-blue ratio (RBR to the RBR of a clear sky library (CSL generated from images captured on clear days. The difference, rather than the ratio, between pixel RBR and CSL RBR resulted in more accurate cloud classification. High correlation between TSI image RBR and aerosol optical depth (AOD measured by an AERONET photometer was observed and motivated the addition of a haze correction factor (HCF to the classification model to account for variations in AOD. Thresholds for clear and thick clouds were chosen based on a training image set and validated with set of manually annotated images. Misclassifications of clear and thick clouds into the opposite category were less than 1%. Thin clouds were classified with an accuracy of 60%. Accurate cloud detection and opacity classification techniques will improve the accuracy of short-term solar power forecasting.

  14. A method for cloud detection and opacity classification based on ground based sky imagery

    Directory of Open Access Journals (Sweden)

    M. S. Ghonima

    2012-11-01

    Full Text Available Digital images of the sky obtained using a total sky imager (TSI are classified pixel by pixel into clear sky, optically thin and optically thick clouds. A new classification algorithm was developed that compares the pixel red-blue ratio (RBR to the RBR of a clear sky library (CSL generated from images captured on clear days. The difference, rather than the ratio, between pixel RBR and CSL RBR resulted in more accurate cloud classification. High correlation between TSI image RBR and aerosol optical depth (AOD measured by an AERONET photometer was observed and motivated the addition of a haze correction factor (HCF to the classification model to account for variations in AOD. Thresholds for clear and thick clouds were chosen based on a training image set and validated with set of manually annotated images. Misclassifications of clear and thick clouds into the opposite category were less than 1%. Thin clouds were classified with an accuracy of 60%. Accurate cloud detection and opacity classification techniques will improve the accuracy of short-term solar power forecasting.

  15. Stark effect modeling in the detailed opacity code SCO-RCG

    CERN Document Server

    Pain, Jean-Christophe; Gilles, Dominique

    2015-01-01

    The broadening of lines by Stark effect is an important tool for inferring electron density and temperature in plasmas. Stark-effect calculations often rely on atomic data (transition rates, energy levels,...) not always exhaustive and/or valid for isolated atoms. We present a recent development in the detailed opacity code SCO-RCG for K-shell spectroscopy (hydrogen- and helium-like ions). This approach is adapted from the work of Gilles and Peyrusse. Neglecting non-diagonal terms in dipolar and collision operators, the line profile is expressed as a sum of Voigt functions associated to the Stark components. The formalism relies on the use of parabolic coordinates within SO(4) symmetry. The relativistic fine-structure of Lyman lines is included by diagonalizing the hamiltonian matrix associated to quantum states having the same principal quantum number $n$. The resulting code enables one to investigate plasma environment effects, the impact of the microfield distribution, the decoupling between electron and i...

  16. Reporting the first 3 years of 225-GHz opacity measurements at the site of the Large Millimeter Telescope Alfonso Serrano

    Science.gov (United States)

    Zeballos, M.; Ferrusca, D.; Contreras R., J.; Hughes, D. H.

    2016-07-01

    The Large Millimeter Telescope Alfonso Serrano (LMT) is located in Puebla, Mexico, at an altitude of 4580 m. It is currently the largest single-dish telescope constructed to observe the Universe at wavelengths between 0.85 and 4 mm. Identifying interstellar molecules, exploring dense dark clouds, and understanding the properties of cold matter and interstellar dust in the local and distant Universe are among its main scientific goals. Since June 2013, the LMT has conducted four shared-risk early science campaigns* observing at 1.1 mm (AzTEC), and 3 mm (RSR) with the aid of a new meteorological and radiometer system to guide the flexibility scheduling of observing time. Here we report measurements of the atmospheric opacity taken with this radiometer at 225 GHz between June 2013 and April 2016. These measurements show that the LMT site has exceptional weather conditions with opacities season, making it a very convenient site for sub-millimeter/millimeter astronomy.

  17. Sulfuric acid vapor and other cloud-related gases in the Venus atmosphere - Abundances inferred from observed radio opacity

    Science.gov (United States)

    Steffes, P. G.; Eshleman, V. R.

    1982-01-01

    It is suggested that the absorbing characteristics of sulfuric acid vapor appear to reconcile what had been thought to be an inconsistency among measurements and deductions regarding the constituents of the Venus atmosphere and radio occultation, radar reflection, and radio emission measurements of its opacity. Laboratory measurements of sulfuric acid, sulfur dioxide, water vapor, and carbon dioxide are used to model relative contributions to opacity as a function of height in a way that is consistent with observations of the constituents and absorbing properties of the atmosphere. It is concluded that sulfuric acid vapor is likely to be the principal microwave absorber in the 30-50 km altitude range of the middle atmosphere of Venus.

  18. APLIKASI ONLINE PUBLIC ACCESS CATALOQUE (OPAC BERBASIS ANDROID SEBAGAI SARANA TEMU KEMBALI INFORMASI DI PERPUSTAKAAN UNIVERSITAS PENDIDIKAN GANESHA

    Directory of Open Access Journals (Sweden)

    Putu Tika Parmawati

    2016-08-01

    Full Text Available Abstrak Penelitian ini bertujuan untuk mengembangkan perangkat lunak aplikasi Online Public Access Cataloque (OPAC berbasis android. Jenis penelitian ini merupakan Research and Development (R & D dengan metode pengembangan menggunakan model prototyping. Pengembangan sistem informasi layanan audio visual berbasis video streaming dengan enam tahap, yaitu : 1 Tahap pengumpulan kebutuhan dan perbaikan, 2 Tahap perancangan desain cepat (desain awal, 3 Tahap membangun prototipe, 4 Tahap evaluasi prototype, 5 Tahap perbaikan prototype, dan 6 Tahap rekayasa produk. Penentuan tingkat kelayakan aplikasi Online Public Access Cataloque (OPAC berbasis android berdasarkan uji validasi ahli bidang teknologi informasi dan uji coba terbatas pada pengguna. Hasil uji coba sebagai berikut : 1 Pengembangan aplikasi Online Public Access Cataloque (OPAC berbasis android sudah sesuai dengan spesifikasi yang telah ditentukan sebagai aplikasi penelusuran informasi koleksi buku teks umum secara online melalui smartphone. 2 Indikator penilaian dari program ini adalah kebenaran atau ketepatan operasional sistem, ketegaran, keterluasan, keterpakaian ulang, efisiensi atau kinerja, portabilitas, integritas, modularitas, keterbacaan mendapat kualifikasi cukup baik, sedangkan verifikasi mendapat kualifikasi baik. 3 Secara umum dari hasil penilaian tersebut aplikasi OPAC berbasis android ini cukup layak untuk digunakan sebagai alternatif pelengkap pemberian layanan penelusuran informasi koleksi buku teks umum di Perpustakaan Undiksha. Kata Kunci: OPAC, android, dan temu kembali informasi Abstract Aim of this study to develop the software of Online Public Access Cataloque (OPAC based on android. Research and Development (R & D design was applied in this study which was developed through prototyping models. The software was constructed through six stages, namely: 1 needs analysis and repairment, 2 rapid design (preliminary design, 3 prototypes building, 4 prototype evaluation, 5

  19. Quantifying equation-of-state and opacity errors using integrated supersonic diffusive radiation flow experiments on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Guymer, T. M., E-mail: Thomas.Guymer@awe.co.uk; Moore, A. S.; Morton, J.; Allan, S.; Bazin, N.; Benstead, J.; Bentley, C.; Comley, A. J.; Garbett, W.; Reed, L.; Stevenson, R. M. [AWE Plc., Aldermaston, Reading RG7 4PR (United Kingdom); Kline, J. L.; Cowan, J.; Flippo, K.; Hamilton, C.; Lanier, N. E.; Mussack, K.; Obrey, K.; Schmidt, D. W.; Taccetti, J. M. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); and others

    2015-04-15

    A well diagnosed campaign of supersonic, diffusive radiation flow experiments has been fielded on the National Ignition Facility. These experiments have used the accurate measurements of delivered laser energy and foam density to enable an investigation into SESAME's tabulated equation-of-state values and CASSANDRA's predicted opacity values for the low-density C{sub 8}H{sub 7}Cl foam used throughout the campaign. We report that the results from initial simulations under-predicted the arrival time of the radiation wave through the foam by ≈22%. A simulation study was conducted that artificially scaled the equation-of-state and opacity with the intended aim of quantifying the systematic offsets in both CASSANDRA and SESAME. Two separate hypotheses which describe these errors have been tested using the entire ensemble of data, with one being supported by these data.

  20. Streptococcal Serum Opacity Factor promotes Cholesterol Ester Metabolism and Bile Acid Secretion In Vitro and In Vivo

    OpenAIRE

    Gillard, Baiba K.; Rodriguez, Perla J; Fields, David W.; Raya, Joe L.; Lagor, William R.; Rosales, Corina; Courtney, Harry S.; Gotto, Antonio M.; Pownall, Henry J.

    2015-01-01

    Plasma high density lipoprotein-cholesterol (HDL-C) concentrations negatively correlate with atherosclerotic cardiovascular disease. HDL is thought to have several atheroprotective functions, which are likely distinct from the epidemiological inverse relationship between HDL-C levels and risk. Specifically, strategies that reduce HDL-C while promoting reverse cholesterol transport (RCT) may have therapeutic value. The major product of the serum opacity factor (SOF) reaction versus HDL is a ch...

  1. Influence of the number of atomic levels on the spectral opacity of low temperature nickel and iron in the spectral range 50–300 eV

    Directory of Open Access Journals (Sweden)

    Busquet M.

    2013-11-01

    Full Text Available Opacity is a fundamental ingredient for the secular evolution of stars. The calculation of the stellar plasma absorption coefficients is complex due to the composition of these plasmas, generally an H /He dominated mixture with a low concentration of partially ionized heavy ions (the iron group. The international collaboration OPAC recently presented extensive comparisons of spectral opacities of iron and nickel for temperatures between 15 and 40 eV and for densities of ∼ 3 mg/cm3, relevant to the stellar envelope conditions [1, 2]. The role of Configuration Interaction (CI and the influence of the number of atomic levels on the opacity using the recently improved version of HULLAC atomic code [3, 4] are illustrated in this article. Comparisons with theoretical predictions already presented in [1] are discussed.

  2. Mid-infrared mapping of Jupiter's temperatures, aerosol opacity and chemical distributions with IRTF/TEXES

    Science.gov (United States)

    Fletcher, Leigh N.; Greathouse, T. K.; Orton, G. S.; Sinclair, J. A.; Giles, R. S.; Irwin, P. G. J.; Encrenaz, T.

    2016-11-01

    Global maps of Jupiter's atmospheric temperatures, gaseous composition and aerosol opacity are derived from a programme of 5-20 μm mid-infrared spectroscopic observations using the Texas Echelon Cross Echelle Spectrograph (TEXES) on NASA's Infrared Telescope Facility (IRTF). Image cubes from December 2014 in eight spectral channels, with spectral resolutions of R ∼2000 - 12 , 000 and spatial resolutions of 2-4° latitude, are inverted to generate 3D maps of tropospheric and stratospheric temperatures, 2D maps of upper tropospheric aerosols, phosphine and ammonia, and 2D maps of stratospheric ethane and acetylene. The results are compared to a re-analysis of Cassini Composite Infrared Spectrometer (CIRS) observations acquired during Cassini's closest approach to Jupiter in December 2000, demonstrating that this new archive of ground-based mapping spectroscopy can match and surpass the quality of previous investigations, and will permit future studies of Jupiter's evolving atmosphere. The visibility of cool zones and warm belts varies from channel to channel, suggesting complex vertical variations from the radiatively-controlled upper troposphere to the convective mid-troposphere. We identify mid-infrared signatures of Jupiter's 5-μm hotspots via simultaneous M, N and Q-band observations, which are interpreted as temperature and ammonia variations in the northern Equatorial Zone and on the edge of the North Equatorial Belt (NEB). Equatorial plumes enriched in NH3 gas are located south-east of NH3-desiccated 'hotspots' on the edge of the NEB. Comparison of the hotspot locations in several channels across the 5-20 μm range indicate that these anomalous regions tilt westward with altitude. Aerosols and PH3 are both enriched at the equator but are not co-located with the NH3 plumes. The equatorial temperature minimum and PH3/aerosol maxima have varied in amplitude over time, possibly as a result of periodic equatorial brightenings and the fresh updrafts of

  3. EOSTA-an improved EOS quantum mechanical model in the STA opacity code

    Energy Technology Data Exchange (ETDEWEB)

    Bar-Shalom, A. [Koifman 32, Beer-Sheva (Israel) and Artep Inc., Columbia, MD 21045 (United States)]. E-mail: avibs@bgumail.bgu.ac.il; Oreg, J. [Artep Inc., Columbia, MD 21045 (United States); Klapisch, M. [Artep Inc., Columbia, MD 21045 (United States)

    2006-05-15

    The STA model is extended to include calculations of thermodynamical quantities required for equation of state (EOS). For that purpose the plasma free electrons are now treated quantum mechanically accounting for shape resonances. The resulting gradual orbital ionization assures a regular behavior of all the thermodynamical quantities vs. density and temperature. The relativistic quantum mechanical framework that we have applied in a new code named EOSTA follows Liberman's Inferno model with several improvements that accomplish higher accuracy. These improvements include: a numerical technique to trace all the resonances and follow their detailed structure and application of the phase amplitude method that allows the inclusion of higher angular momenta partial waves and higher energies of the free orbitals. In addition we employ two complementary methods to treat the exchange potential in the calculation of orbital wave functions: (1) for EOS calculations Local Density Approximation is used and (2) for ionization lowering and orbital energies required in the opacity calculations we have found two satisfactory alternatives: (a) the optimized effective potential (OEP) and (b) first order corrected Local Density Approximation. In both alternatives the resulting orbitals are used to calculate the detailed exchange term that includes a proper reduction of the self energy. A new approach for calculating the electronic pressure is presented. The relativistic virial theorem expresses the pressure as a sum of the total energy and a local density term. This form allows consistent calibration of the correlation energy to comply with the periodic table zero pressure density points and higher density pressures. Results are presented describing the various thermodynamical quantities vs. density and temperature in comparison with other calculations and experiments.

  4. Percutaneous Radiofrequency Ablation of Lung Cancer Presenting as Ground-Glass Opacity

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Toshihiro, E-mail: iguchi@ba2.so-net.ne.jp; Hiraki, Takao, E-mail: takaoh@tc4.so-net.ne.jp; Gobara, Hideo, E-mail: gobara@cc.okayama-u.ac.jp; Fujiwara, Hiroyasu, E-mail: hirofujiwar@gmail.com; Matsui, Yusuke, E-mail: wckyh140@yahoo.co.jp [Okayama University Medical School, Department of Radiology (Japan); Soh, Junichi, E-mail: soh-j@cc.okayama-u.ac.jp; Toyooka, Shinichi, E-mail: shintoyooka@gmail.com [Okayama University Medical School, Department of General Thoracic Surgery (Japan); Kiura, Katsuyuki, E-mail: kkiura@md.okayama-u.ac.jp [Okayama University Medical School, Department of Respiratory Medicine (Japan); Kanazawa, Susumu, E-mail: susumu@cc.okayama-u.ac.jp [Okayama University Medical School, Department of Radiology (Japan)

    2015-04-15

    PurposeWe retrospectively evaluated the outcomes of lung cancer patients presenting with ground-glass opacity (GGO) who received radiofrequency ablation (RFA).MethodsSixteen patients (5 men and 11 women; mean age, 72.6 years) with 17 lung cancer lesions showing GGO (mean long axis diameter, 1.6 cm) underwent a total of 20 percutaneous computed tomography (CT) fluoroscopy-guided RFA sessions, including three repeated sessions for local progression. Lung cancer with GGO was defined as a histologically confirmed malignant pulmonary lesion with a GGO component accounting for >50 % of the lesion on high-resolution CT. Procedure outcomes were evaluated.ResultsThere were no major complications. Pneumothorax occurred in 15 of 20 treatment sessions: 14 were asymptomatic, and 1 required chest tube placement but resolved satisfactorily within 48 h. Minor pulmonary hemorrhage occurred in two and mild pneumonitis in one. The median tumor follow-up period was 61.5 (range 6.1–96.6) months. The effectiveness rates of the primary and secondary techniques were 100 and 100 % at 1 year, 93.3 and 100 % at 2 years, and 78.3 and 92.3 % at 3 years, respectively. The median patient follow-up period was 65.6 (range 6.1–96.6) months. One patient died owing to recurrent other cancer 11.7 months after RFA, whereas the other 15 remained alive. Overall survival and disease-specific survival rates were 93.3 and 100 % at 1 year and 93.3 and 100 % at 5 years, respectively.ConclusionsRFA for lung cancer with GGO was safe and effective, and resulted in promising survival rates.

  5. The role of opacity and transparency in achieving strategic stability in South Asia.

    Energy Technology Data Exchange (ETDEWEB)

    Rajain, Arpit (New Delhi, India); Ashraf, Tariq Mahmud (Islamabad, Pakistan)

    2005-08-01

    According to international relations theory, deterrence can be used as a tool to achieve stability between potentially hostile nations. India and Pakistan's long history of periodic crises raises the question of how they can achieve deterrence stability. 'Transparency' describes the flow of information between parties and plays a key role in establishing a deterrence relationship. This paper studies the balance needed between opacity and transparency in nuclear topics for the maintenance of deterrence stability between India and Pakistan. States with nuclear weapons are postulated to implement transparency in four categories: potential, capability, intent, and resolve. The study applies these categories to the nuclear components of the ongoing India-Pakistan Composite Dialogue Working Group for Peace and Security including CBMs. To focus our efforts, we defined four scenarios to characterize representative strategic/military/political conditions. The scenarios are combinations of these two sets of opposite poles: competition - cooperation; extremism - moderation (to be understood primarily in a religious/nationalistic sense). We describe each scenario in terms of select focal areas (nuclear doctrine, nuclear command and control, nuclear stockpile, nuclear delivery/defensive systems, and conventional force posture). The scenarios help frame the realm of possibilities, and have been described in terms of expected conditions for the focal areas. We then use the conditions in each scenario to prescribe a range of information-sharing actions that the two countries could take to increase stability. We also highlight the information that should not be shared. These actions can be political (e.g., declarations), procedural (e.g., advance notice of certain military activities), or technologically based (e.g., seismic monitoring of the nuclear test moratorium).

  6. Direct atmosphere opacity observations from CALIPSO provide new constraints on cloud-radiation interactions

    Science.gov (United States)

    Guzman, R.; Chepfer, H.; Noel, V.; Vaillant de Guélis, T.; Kay, J. E.; Raberanto, P.; Cesana, G.; Vaughan, M. A.; Winker, D. M.

    2017-01-01

    The spaceborne lidar CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) directly measures atmospheric opacity. In 8 years of CALIPSO observations, we find that 69% of vertical profiles penetrate through the complete atmosphere. The remaining 31% do not reach the surface, due to opaque clouds. The global mean altitude of full attenuation of the lidar beam (z_opaque) is 3.2 km, but there are large regional variations in this altitude. Of relevance to cloud-climate studies, the annual zonal mean longwave cloud radiative effect and annual zonal mean z_opaque weighted by opaque cloud cover are highly correlated (0.94). The annual zonal mean shortwave cloud radiative effect and annual zonal mean opaque cloud cover are also correlated (-0.95). The new diagnostics introduced here are implemented within a simulator framework to enable scale-aware and definition-aware evaluation of the LMDZ5B global climate model. The evaluation shows that the model overestimates opaque cloud cover (31% obs. versus 38% model) and z_opaque (3.2 km obs. versus 5.1 km model). In contrast, the model underestimates thin cloud cover (35% obs. versus 14% model). Further assessment shows that reasonable agreement between modeled and observed longwave cloud radiative effects results from compensating errors between insufficient warming by thin clouds and excessive warming due to overestimating both z_opaque and opaque cloud cover. This work shows the power of spaceborne lidar observations to directly constrain cloud-radiation interactions in both observations and models.

  7. Effect of irradiation times on the polymerization depth of contemporary fissure sealants with different opacities

    Directory of Open Access Journals (Sweden)

    Boniek Castillo Dutra Borges

    2011-04-01

    Full Text Available The aim of this study was to evaluate the depth of curing of 10 contemporary blue light-activated dental flowable materials at several opacities, influenced by different irradiation times using FT-IR spectroscopy. Fifty-five specimens (n = 5 with a 5-mm diameter and 1-mm thickness of translucent (Opallis Flow T, yellowed (Master Flow A2; Opallis Flow A2; Natural Flow A2; Fluroshield Yellowed, and opaque materials (Master Flow OA2; Natural Flow O; Opallis Flow OA3.5; Opallis Flow OP; Fluroshield White were obtained at six curing times (10s, 20s, 30s, 40s, 50s, and 60s using a high-intensity LED (Coltolux, Coltène/Whaledent. The degree of conversion (DC (% was obtained using the Nexus 470 FTIR Spectrometer (Nicolet Instruments, USA. The FTIR-ATR spectra for uncured and cured samples were analyzed using a ZnSe crystal. The top and bottom surfaces of the cured specimens were analyzed to obtain the depth of curing. Two-way ANOVA was used to analyze the data. The highest curing depth was obtained by Natural Flow OA2, while the lowest was shown by Master Flow OA2. The shortest curing time generated similar depths of cure in comparison with the most extensive for Opallis Flow A2 and Fluroshield Yellowed. Therefore, depth of curing, influenced by the irradiation time, was dependent on the materials. Using the Natural Flow OA2 opaque sealant and the 10-s curing time for Opallis Flow A2 and Fluroshield Yellowed may represent alternative approaches to sealing tooth fissures.

  8. Measurements of X-ray spectral opacity of dense plasma at Iskra-5 laser facility

    Energy Technology Data Exchange (ETDEWEB)

    Annenkov, V.I.; Bel' kov, S.A.; Bessarab, A.V.; Bondarenko, S.V.; Garanin, R.V.; Kochemasov, G.G.; Kovalenko, V.P.; Pinegin, A.V.; Suslov, N.A.; Zhidkov, N.V. [Russian Federal Nuclear Centre - VNIIEF, Sarov (Russian Federation)

    2006-06-15

    The powerful iodine ISKRA-5 laser facility has been upgraded and now operates on the second harmonic. Experiments were performed to measure the X-ray spectral opacity of dense plasma of different materials. Sample of Al and Au material under study was fabricated as a thin plate with the 0.1-0.15 {mu}m thickness and was heated by the soft X-rays generated by irradiation of a thin film gold converter by one beam of the ISKRA-5 laser facility. Typical laser intensity on the converter was (1-5).10{sup 13} W/cm{sup 2} and laser pulse duration was 0.5-0.6 ns. The effective temperature of sample under experimental conditions did not exceed 30-40 eV. The sample was tempered by about 1 {mu}m plastic layers on both sides to avoid its rarefaction during heating and to obtain a quasi-stationary layer of a dense plasma prepared to be probed by a back-lighter. The back-lighter was aluminum or dysprosium film irradiated by another beam of the ISKRA-5 laser facility with an intensity of 10{sup 14}-10{sup 15} W/cm{sup 2}. Probe X-rays were registered by a Bragg spectrometer with spatial resolution. Comparison between experimental data and simulations is discussed. In the case of Al sample, 3 absorption lines corresponding to 1s-2p transition of the Al{sup +4}-Al{sup +6} ions are recorded. The absorption of the Au sample is very close to the absorption of the cold material. The theoretical simulations show that the temperature of the heated Al sample is about 20-25 eV, substantial amount of the Au sample remains unheated at a solid density.

  9. Apolipoprotein modulation of streptococcal serum opacity factor activity against human plasma high-density lipoproteins.

    Science.gov (United States)

    Rosales, Corina; Gillard, Baiba K; Courtney, Harry S; Blanco-Vaca, Francisco; Pownall, Henry J

    2009-08-25

    Human plasma HDL are the target of streptococcal serum opacity factor (SOF), a virulence factor that clouds human plasma. Recombinant (r) SOF transfers cholesteryl esters (CE) from approximately 400,000 HDL particles to a CE-rich microemulsion (CERM), forms a cholesterol-poor HDL-like particle (neo HDL), and releases lipid-free (LF) apo A-I. Whereas the rSOF reaction requires labile apo A-I, the modulation effects of other apos are not known. We compared the products and rates of the rSOF reaction against human HDL and HDL from mice overexpressing apos A-I and A-II. Kinetic studies showed that the reactivity of various HDL species is apo-specific. LpA-I reacts faster than LpA-I/A-II. Adding apos A-I and A-II inhibited the SOF reaction, an effect that was more profound for apo A-II. The rate of SOF-mediated CERM formation was slower against HDL from mice expressing human apos A-I and A-II than against WT mice HDL and slowest against HDL from apo A-II overexpressing mice. The lower reactivity of SOF against HDL containing human apos is due to the higher hydropathy of human apo A-I, particularly its C-terminus relative to mouse apo A-I, and the higher lipophilicity of human apo A-II. The SOF-catalyzed reaction is the first to target HDL rather than its transporters and receptors in a way that enhances reverse cholesterol transport (RCT). Thus, effects of apos on the SOF reaction are highly relevant. Our studies show that the "humanized" apo A-I-expressing mouse is a good animal model for studies of rSOF effects on RCT in vivo.

  10. Streptococcal Serum Opacity Factor Increases Hepatocyte Uptake of Human Plasma High Density Lipoprotein-Cholesterol1

    Science.gov (United States)

    Gillard, Baiba K.; Rosales, Corina; Pillai, Biju K.; Lin, Hu Yu; Courtney, Harry S.; Pownall, Henry J.

    2010-01-01

    Serum opacity factor (SOF), a virulence determinant of Streptococcus pyogenes, converts plasma high density lipoproteins (HDL) to three distinct species: lipid-free apolipoprotein (apo) A-I, neo HDL, a small discoidal HDL-like particle, and a large cholesteryl ester-rich microemulsion (CERM), that contains the cholesterol esters (CE) of up to ~400,000 HDL particles and apo E as its major protein. Similar SOF reaction products are obtained with HDL, total plasma lipoproteins and whole plasma. We hypothesized that hepatic uptake of CERM-CE via multiple apo E dependent receptors would be faster than that of HDL-CE. We tested our hypothesis using human hepatoma cells and lipoprotein receptor-specific Chinese hamster ovary (CHO) cells. [3H]CE uptake by HepG2 and Huh7 cells from HDL after SOF treatment, which transfers >90% of HDL-CE to CERM, was respectively 2.4 and 4.5 times faster than from control HDL. CERM-[3H]CE uptake was inhibited by LDL and HDL, suggestive of uptake by both the LDL receptor (LDL-R) and scavenger receptor class B type I (SR-BI). Studies in CHO cells specifically expressing LDL-R and SR-BI confirmed CERM-[3H]CE uptake by both receptors. RAP and heparin inhibit CERM-[3H]CE but not HDL-[3H]CE uptake thereby implicating LRP-1 and cell surface proteoglycans in this process. These data demonstrate that SOF treatment of HDL increases CE uptake via multiple hepatic apo E receptors. In so doing, SOF might increase hepatic disposal of plasma cholesterol in a way that is therapeutically useful. PMID:20879789

  11. The opacity of the universe for high and very high energy {gamma}-rays

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Manuel

    2013-08-15

    }{sub {gamma}{gamma}}<1 to {tau}{sub {gamma}{gamma}}{>=}2 is investigated. The absorption-corrected spectra consistently show an upturn at high optical depths, significant at the 4{sigma} level. A source intrinsic effect is unlikely to produce such a feature, since the transition to the {tau}{sub {gamma}{gamma}}{>=}2 regime occurs at different energies for each source. Systematic uncertainties that could mimic the effect are studied but found unlikely as a possible explanation. A similar study is conducted for photons detected with the Fermi-LAT. To this end, the number of expected photons in the optical thick regime is compared to the number of photons observed with the LAT. Above {tau}{sub {gamma}{gamma}}{>=}2, three photons are associated with AGN with high confidence. Under the assumption of certain EBL models, extrapolating the unattenuated spectrum from low to high energies results in a probability of 1.2 x 10{sup -4} to observe these photons. However, the probability for detecting the high optical depth photons when all LAT detected AGN with known redshift are considered sensitively depends on the choice of the intrinsic spectral model. The indication for a reduced opacity might be explained by the oscillation of photons into hypothetical axion-like particles (ALPs) in ambient magnetic fields. Such particles propagate unimpeded over cosmological distances, thereby reducing the {gamma}-ray opacity. Photon-ALP conversions are studied in different magnetic field configurations, including intracluster and intergalactic magnetic fields, as well as the field of the Milky Way. Optimistic values of the field strength and coherence length result in lower limits on the photon-ALP coupling, g{sub a{gamma}}>or similar 10{sup -12} GeV{sup -1}. For more realistic magnetic field parameters, couplings above g{sub a{gamma}}>or similar 2 x 10{sup 11} GeV{sup -1} are necessary to explain the indication for the reduced opacity. The lower limits are in reach of future dedicated ALP

  12. Laboratory measurements of the 5-20 cm wavelength opacity of ammonia, water vapor, and methane under simulated conditions for the deep jovian atmosphere

    Science.gov (United States)

    Bellotti, Amadeo; Steffes, Paul G.; Chinsomboom, Garrett

    2016-12-01

    Over the past decade, several extensive laboratory studies have been conducted of the microwave opacity of ammonia and water vapor in preparation for interpretation of the precise measurements of jovian microwave emission to be made with the Microwave Radiometer (MWR) instrument aboard the NASA Juno Mission. (See, e.g., Hanley et al. [2009] Icarus, 202, 316-335; Karpowicz and Steffes [2011a] Icarus 212, 210-223; Karpowicz and Steffes [2011b] Icarus 214, 783; Devaraj et al. [2014] Icarus, 241, 165-179) These works included models for the opacity of these constituents valid over the pressure and temperature ranges measured in the laboratory experiments (temperatures up to 500 K and pressures up to 100 bars). However, studies of the microwave emission made using these models indicate that significant contributions to the emission at the 24-cm and 50-cm wavelengths to be measured by the Juno MWR will be made by layers of the atmosphere with temperatures at or exceeding 600 K. While the ammonia opacity models described by Hanley et al. (2009) and Devraj et al. (2014) give consistent results at temperatures up to 500 K (within 6%), they diverge significantly at temperatures and pressures exceeding 550 K and 50 bars, respectively. Similarly, at temperatures above 500 K, the model for water vapor opacity developed by Karpowicz and Steffes (2011a,b) exhibits non-physical attributes. To resolve these ambiguities, we have conducted laboratory measurements of the microwave opacity of ammonia at temperatures up to 600 K and that for water vapor at temperatures up to 600 K. Additionally, since the microwave opacity of ammonia is influenced by pressure-broadening from methane (a significant constituent in jovian atmospheres), measurements of the effects of methane on the ammonia absorption spectrum have also been conducted. These measurements have resulted in updated models for the opacities of ammonia and water vapor under conditions of the deep jovian atmosphere.

  13. The Impact of Language Opacity and Proficiency on Reading Strategies in Bilinguals: An Eye Movement Study

    Science.gov (United States)

    de León Rodríguez, Diego; Buetler, Karin A.; Eggenberger, Noëmi; Laganaro, Marina; Nyffeler, Thomas; Annoni, Jean-Marie; Müri, René M.

    2016-01-01

    Reading strategies vary across languages according to orthographic depth – the complexity of the grapheme in relation to phoneme conversion rules – notably at the level of eye movement patterns. We recently demonstrated that a group of early bilinguals, who learned both languages equally under the age of seven, presented a first fixation location (FFL) closer to the beginning of words when reading in German as compared with French. Since German is known to be orthographically more transparent than French, this suggested that different strategies were being engaged depending on the orthographic depth of the used language. Opaque languages induce a global reading strategy, and transparent languages force a local/serial strategy. Thus, pseudo-words were processed using a local strategy in both languages, suggesting that the link between word forms and their lexical representation may also play a role in selecting a specific strategy. In order to test whether corresponding effects appear in late bilinguals with low proficiency in their second language (L2), we present a new study in which we recorded eye movements while two groups of late German–French and French–German bilinguals read aloud isolated French and German words and pseudo-words. Since, a transparent reading strategy is local and serial, with a high number of fixations per stimuli, and the level of the bilingual participants’ L2 is low, the impact of language opacity should be observed in L1. We therefore predicted a global reading strategy if the bilinguals’ L1 was French (FFL close to the middle of the stimuli with fewer fixations per stimuli) and a local and serial reading strategy if it was German. Thus, the L2 of each group, as well as pseudo-words, should also require a local and serial reading strategy. Our results confirmed these hypotheses, suggesting that global word processing is only achieved by bilinguals with an opaque L1 when reading in an opaque language; the low level in the L2

  14. The Column Density Distribution and Continuum Opacity of the Intergalactic and Circumgalactic Medium at Redshift langzrang = 2.4

    Science.gov (United States)

    Rudie, Gwen C.; Steidel, Charles C.; Shapley, Alice E.; Pettini, Max

    2013-06-01

    We present new high-precision measurements of the opacity of the intergalactic and circumgalactic medium (IGM; CGM) at langzrang = 2.4. Using Voigt profile fits to the full Lyα and Lyβ forests in 15 high-resolution high-S/N spectra of hyperluminous QSOs, we make the first statistically robust measurement of the frequency of absorbers with H I column densities 14 \\lesssim log (N_H\\,\\scriptsize{ I}/ {cm}^{-2}) \\lesssim 17.2. We also present the first measurements of the frequency distribution of H I absorbers in the volume surrounding high-z galaxies (the CGM, 300 pkpc), finding that the incidence of absorbers in the CGM is much higher than in the IGM. In agreement with Rudie et al., we find that there are fractionally more high-N H I absorbers than low-N H I absorbers in the CGM compared to the IGM, leading to a shallower power law fit to the CGM frequency distribution. We use these new measurements to calculate the total opacity of the IGM and CGM to hydrogen-ionizing photons, finding significantly higher opacity than most previous studies, especially from absorbers with log (N_H\\,\\scriptsize{ I}/ {cm}^{-2}) background and of ionizing sources at z ≈ 2-3. Based on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration, and was made possible by the generous financial support of the W. M. Keck Foundation.

  15. NASCA Report 2: Longitudinal Study of Relationship of Exposure to Space Radiation and Risk of Lens Opacity

    Science.gov (United States)

    Chylack, Leon T., Jr.; Peterson, Leif E.; Feiveson, Alan H.; Tung, William H.; Wear, Mary L.; Marak, Lisa J.; Hardy, Dale S.; Cucinotta, Francis A.

    2011-01-01

    The NASA Study of Cataract in Astronauts (NASCA) was a five-year longitudinal study of the effect of space radiation exposure on the severity/progression of nuclear (N), cortical (C), and posterior subcapsular (PSC) lens opacities. It began in 2003 and was completed in December, 2009. Participants included 171 consenting astronauts who flew at least one mission in space, and comparison subjects consisted of three groups, a) 53 astronauts who had not flown in space, b) 95 military aircrew personnel, and c) 99 non-aircrew, ground-based subjects.

  16. Properties of the Products Formed by the Activity of Serum Opacity Factor against Human Plasma High Density Lipoproteins

    OpenAIRE

    Pownall, Henry J.; Courtney, Harry S.; Gillard, Baiba K.; Massey, John B.

    2008-01-01

    Serum opacity factor from Streptococcus pyogenes transfers the cholesteryl esters (CE) of ~100,000 plasma high density lipoprotein particles (HDL) to a CE-rich microemulsion (CERM) while forming neo HDL, a cholesterol-poor HDL-like particle. HDL, neo HDL, and CERM are distinct. Neo HDL is lower in free cholesterol and has lower surface and total microviscosities than HDL; the surface polarity of neo HDL and HDL are similar. CERM is much larger than HDL and richer in cholesterol and CE. Althou...

  17. 医学院校图书馆 OPAC 图书智能推荐系统分析与设计%Analysis and Design of the OPAC Book Intelligent Recommendation System for Libraries in Medical Colleges and Universities

    Institute of Scientific and Technical Information of China (English)

    吕文娟; 龚佳剑

    2015-01-01

    〔Abstract〕 The paper introduces existing OPAC recommendation modules in colleges and universities.Based on characteristics of libraries in medical colleges and universities and in combination with prevailing recommendation technology, it proposes to utilize the algorithm of Mahout of Hadoop Platform to design the library intelligent recommendation system .By embedding the intelligent recommendation system into OPAC , it solves the problem of personalized recommendation and provides readers with active and intelligent personalized services .%介绍目前各高校OPAC推荐模块,基于医学院校图书馆的特点,结合目前流行的推荐技术,提出利用Hadoop平台的Mahout算法设计图书智能推荐系统。通过将智能推荐系统嵌入OPAC,解决个性化推荐问题,为读者提供主动智能化的个性服务。

  18. On the necessity of composition-dependent low-temperature opacity in metal-poor AGB stars

    CERN Document Server

    Constantino, Thomas; Gil-Pons, Pilar; Lattanzio, John

    2014-01-01

    The vital importance of composition-dependent low-temperature opacity in low-mass (M 0.001 has recently been demonstrated (e.g. Marigo 2002; Ventura & Marigo 2010). Its significance to more metal-poor, intermediate mass (M > 2.5Msun) models has yet to be investigated. We show that its inclusion in lower-metallicity models ([Fe/H] < -2) is essential, and that there exists no threshold metallicity below which composition-dependent molecular opacity may be neglected. We find it to be crucial in all intermediate-mass models investigated ([Fe/H] < -2 and 2.5 < M/Msun < 5), because of the evolution of the surface chemistry, including the orders of magnitude increase in the abundance of molecule-forming species. Its effect on these models mirrors that previously reported for higher-metallicity models - increase in radius, decrease in Teff, faster mass loss, shorter thermally pulsing AGB lifetime, reduced enrichment in third dredge-up products (by a factor of three to ten), and an increase in the mas...

  19. Impact of Laser Capsulotomy in the Quality of Life of the Elderly with Posterior Capsule Opacity after Cataract Surgery

    Directory of Open Access Journals (Sweden)

    Armando Rafael Milanés Armengol

    2013-04-01

    Full Text Available Background: the opacity of the posterior lens capsule after cataract surgery has decreased in recent years but its incidence remains high.Objective: To assess the impact of the opacification of the posterior lens capsule and its treatment with laser capsulotomy on visual function and life quality of patients after cataract surgery. Methods: A case series study of elderly patients with diagnose of opacity in the posterior lens capsule after cataract surgery who were treated with laser capsulotomy from January 2010 to January 2011 in the General University Hospital of Cienfuegos was conducted. A survey and a battery of assessment tools to measure functional status were applied as well as the VF-14 test for the assessment of life quality. Results: We observed an improvement in the average value of the visual acuity (0, 326 by 0, 726 practiced capsulotomy to later, with an average range of efficiency improvement of a binocular visual 6.96%, likewise improved functional visual capacity from 57, 728 to 96, 223; exploration by VF-14 showed a higher life quality. The degree of overall validism was recovered in 86, 56 % of patients and only one patient was totally dependent for the realization of daily life activities. Conclusions: Patients who underwent laser capsulotomy showed evidence of improvement in visual acuity, functionality and life quality.

  20. Large scale opacity fluctuations in the Lyman alpha forest: evidence for QSOs dominating the ionising UV background at z ~ 5.5-6 ?

    CERN Document Server

    Chardin, Jonathan; Haehnelt, Martin G

    2016-01-01

    Lyman-alpha forest data probing the post-reionization Universe shows surprisingly large opacity fluctuations over rather large ($\\ge$50 comoving Mpc/h) spatial scales. We model these fluctuations using a hybrid approach utilizing the large volume Millennium simulation to predict the spatial distribution of QSOs combined with smaller scale full hydrodynamical simulation performed with RAMSES and post-processed with the radiative transfer code ATON. We produce realictic mock absorption spectra that account for the contribution of galaxies and QSOs to the ionising UV background. This improved models confirm our earlier findings that a significant ($\\ge$50%) contribution of ionising photons from QSOs can explain the large reported opacity fluctuations on large scales. The inferred QSO luminosity function is thereby consistent with recent estimates of the space density of QSOs at this redshift. Our simulations still somewhat struggle, however, to reproduce the very long (110 comoving Mpc/h) high opacity absorption...

  1. Measurements of the K -Shell Opacity of a Solid-Density Magnesium Plasma Heated by an X-Ray Free-Electron Laser

    Science.gov (United States)

    Preston, T. R.; Vinko, S. M.; Ciricosta, O.; Hollebon, P.; Chung, H.-K.; Dakovski, G. L.; Krzywinski, J.; Minitti, M.; Burian, T.; Chalupský, J.; Hájková, V.; Juha, L.; Vozda, V.; Zastrau, U.; Lee, R. W.; Wark, J. S.

    2017-08-01

    We present measurements of the spectrally resolved x rays emitted from solid-density magnesium targets of varying sub-μ m thicknesses isochorically heated by an x-ray laser. The data exhibit a largely thickness-independent source function, allowing the extraction of a measure of the opacity to K -shell x rays within well-defined regimes of electron density and temperature, extremely close to local thermodynamic equilibrium conditions. The deduced opacities at the peak of the K α transitions of the ions are consistent with those predicted by detailed atomic-kinetics calculations.

  2. Sensitivity of Venus surface emissivity retrieval to model variations of CO2 opacity, cloud features, and deep atmosphere temperature field

    Science.gov (United States)

    Kappel, David; Arnold, Gabriele; Haus, Rainer

    2012-07-01

    The Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) aboard ESA's Venus Express space probe has acquired a wealth of nightside emission spectra from Venus and provides the first global database for systematic atmospheric and surface studies in the IR. The infrared mapping channel (VIRTIS-M-IR) sounds the atmosphere and surface at high spatial and temporal resolution and coverage. Quantitative analyses of data call for a sophisticated radiative transfer simulation model of Venus' atmosphere to be used in atmospheric and surface parameter retrieval procedures that fit simulated spectra to the measured data. The surface emissivity can be retrieved from VIRTIS-M-IR measurements in the transparency windows around 1 μm, but it is not easy to derive, since atmospheric influences strongly interfere with surface information. There are mainly three atmospheric model parameters that may affect quantitative results of surface emissivity retrievals: CO_2 opacity, cloud features, and deep atmosphere temperature field. The CO_2 opacity with respect to allowed transitions is usually computed by utilizing a suitable line data base and certain line shape models that consider collisional line mixing. Both line data bases and shape models are not well established from measurements under the environmental conditions in the deep atmosphere of Venus. Pressure-induced additional continuum absorption introduces further opacity uncertainties. The clouds of Venus are usually modeled by a four-modal distribution of spherical droplets of about 75% sulfuric acid, where each mode is characterized by a different mean and standard deviation of droplet size distribution and a different initial altitude abundance profile. The influence of possible cloud mode variations on surface emissivity retrieval results is investigated in the paper. Future retrieval procedures will aim at a separation of cloud mode and surface emissivity variations using different atmospheric windows sounded by

  3. Breakdown of interlocking domains may contribute to formation of membranous globules and lens opacity in ephrin-A5(-/-) mice.

    Science.gov (United States)

    Biswas, Sondip; Son, Alexander; Yu, Qili; Zhou, Renping; Lo, Woo-Kuen

    2016-04-01

    Ephrin-A5, a ligand of the Eph family of receptor tyrosine kinases, plays a key role in lens fiber cell packing and cell-cell adhesion, with approximately 87% of ephrin-A5(-/-) mice develop nuclear cataracts. Here, we investigated the extensive formation of light-scattering globules associated with breakdown of interlocking protrusions during lens opacification in ephrin-A5(-/-) mice. Lenses from wild-type (WT) and ephrin-A5(-/-) mice between 2 and 21 weeks old were studied with light and electron microscopy, immunofluorescence labeling, freeze-fracture TEM and filipin cytochemistry for membrane cholesterol detection. Lens opacities with various densities were first observed in ephrin-A5(-/-) mice at around 60 days old. Dense cataracts in the mutant lenses were seen primarily in the nuclear region surrounded by transparent cortices from all eyes examined. We confirmed that a majority of nuclear cataracts were dislocated posteriorly and ruptured the thinner posterior lens capsule. SEM analysis indicated that numerous interlocking protrusions and wavy ridge-and-valley membrane surfaces in deep cortical and nuclear fibers did not cause lens opacity in both transparent ephrin-A5(-/-) and WT mice. In contrast, abundant isolated membranous globules of approximately 1000 nm in size were distributed randomly along the intact fiber cells during early stage of all ephrin-A5(-/-) cataracts examined. A further examination using both SEM and TEM revealed that isolated globules were generated from the disintegrated interlocking protrusions originally located along the corners of hexagonal fiber cells. Freeze-fracture TEM further revealed the association of square-array aquaporin junctions with both isolated globules and interlocking membrane domains. This study reports for the first time that disrupted interlocking protrusions are the source of numerous large membranous globules that contribute to light scattering and nuclear cataracts in the ephrin-A5(-/-) mice. Our results

  4. Clinical, pathological, and radiological characteristics of solitary ground-glass opacity lung nodules on high-resolution computed tomography

    Directory of Open Access Journals (Sweden)

    Qiu ZX

    2016-09-01

    Full Text Available Zhi-Xin Qiu,1 Yue Cheng,1 Dan Liu,1 Wei-Ya Wang,2 Xia Wu,2 Wei-Lu Wu,2 Wei-Min Li1,2 1Department of Respiratory Medicine, 2Department of Pathology, West China Hospital, Sichuan University, Chengdu, People’s Republic of China Background: Lung nodules are being detected at an increasing rate year by year with high-resolution computed tomography (HRCT being widely used. Ground-glass opacity nodule is one of the special types of pulmonary nodules that is confirmed to be closely associated with early stage of lung cancer. Very little is known about solitary ground-glass opacity nodules (SGGNs. In this study, we analyzed the clinical, pathological, and radiological characteristics of SGGNs on HRCT.Methods: A total of 95 resected SGGNs were evaluated with HRCT scan. The clinical, pathological, and radiological characteristics of these cases were analyzed.Results: Eighty-one adenocarcinoma and 14 benign nodules were observed. The nodules included 12 (15% adenocarcinoma in situ (AIS, 14 (17% minimally invasive adenocarcinoma (MIA, and 55 (68% invasive adenocarcinoma (IA. No patients with recurrence till date have been identified. The positive expression rates of anaplastic lymphoma kinase and ROS-1 (proto-oncogene tyrosine-protein kinase ROS were only 2.5% and 8.6%, respectively. The specificity and accuracy of HRCT of invasive lung adenocarcinoma were 85.2% and 87.4%. The standard uptake values of only two patients determined by 18F-FDG positron emission tomography/computed tomography (PET/CT were above 2.5. The size, density, shape, and pleural tag of nodules were significant factors that differentiated IA from AIS and MIA. Moreover, the size, shape, margin, pleural tag, vascular cluster, bubble-like sign, and air bronchogram of nodules were significant determinants for mixed ground-glass opacity nodules (all P<0.05.Conclusion: We analyzed the clinical, pathological, and radiological characteristics of SGGNs on HRCT and found that the size, density

  5. Influence of yttrium iron garnet thickness and heater opacity on the nonlocal transport of electrically and thermally excited magnons

    Science.gov (United States)

    Shan, Juan; Cornelissen, Ludo J.; Vlietstra, Nynke; Ben Youssef, Jamal; Kuschel, Timo; Duine, Rembert A.; van Wees, Bart J.

    2016-11-01

    We studied the nonlocal transport behavior of both electrically and thermally excited magnons in yttrium iron garnet (YIG) as a function of its thickness. For electrically injected magnons, the nonlocal signals decrease monotonically as the YIG thickness increases. For the nonlocal behavior of the thermally generated magnons, or the nonlocal spin Seebeck effect (SSE), we observed a sign reversal which occurs at a certain heater-detector distance, and it is influenced by both the opacity of the YIG/heater interface and the YIG thickness. Our nonlocal SSE results can be qualitatively explained by the bulk-driven SSE mechanism together with the magnon diffusion model. Using a two-dimensional finite element model (2D-FEM), we estimated the bulk spin Seebeck coefficient of YIG at room temperature. The quantitative disagreement between the experimental and modeled results indicates more complex processes going on in addition to magnon diffusion and relaxation, especially close to the contacts.

  6. Focused laser lithographic system with sub-wavelength resolution based on vortex laser induced opacity of photochromic material.

    Science.gov (United States)

    Wei, Zhen; Bai, Jian; Xu, Jianfeng; Wang, Chen; Yao, Yuan; Hu, Neibin; Liang, Yiyong; Wang, Kaiwei; Yang, Guoguang

    2014-12-01

    A focused laser lithographic system combines with vortex laser induced opacity of photochromic layer to write patterns with linewidth below wavelength. A photochromic layer is formed by coating the mixture of metanil yellow and aqueous PVA solution on the photoresist layer. In our system, the center of a lithographic laser with a 405 nm wavelength coincides with the center of vortex laser with a 532 nm wavelength. When a photochromic layer is illuminated by both lasers simultaneously, the absorbance for the lithographic laser decreases at the hollow region of the vortex laser but increases at its annular region, so that a transparent aperture for the lithographic laser is created and its size could be tuned by changing the power of vortex laser; therefore, the linewidth of written patterns is variable. Experimentally, using a 20× lens (NA = 0.4), this system condenses the linewidth of written patterns from 6614 to 350 nm.

  7. Opacity effects in a solid-density aluminium plasma created by photo-excitation with an X-ray laser

    Science.gov (United States)

    Rackstraw, D. S.; Vinko, S. M.; Ciricosta, O.; Cho, B. I.; Engelhorn, K.; Chung, H.-K.; Brown, C. R. D.; Burian, T.; Chalupský, J.; Falcone, R. W.; Graves, C.; Hájková, V.; Higginbotham, A.; Juha, L.; Krzywinski, J.; Lee, H. J.; Messerschmidt, M.; Murphy, C.; Ping, Y.; Scherz, A.; Schlotter, W.; Toleikis, S.; Turner, J. J.; Vysin, L.; Wang, T.; Wu, B.; Zastrau, U.; Zhu, D.; Nagler, B.; Lee, R. W.; Heimann, P. A.; Wark, J. S.

    2014-06-01

    The intensities within the focal spots of the output of recently developed X-ray sources based on free-electron-laser (FEL) technology are so great that atoms within the focal region can potentially absorb several photons during the few tens of femtosecond X-ray pulse. Furthermore, the duration of the FEL X-ray pulse is comparable to the Auger decay times of inner-shell holes created by the X-rays themselves. We report here how such a scenario can lead to opacity broadening of the fluorescence radiation emitted by the hot, dense plasma, which is created as a result of the X-radiation focussed onto a solid target, and in particular present calculations of the broadening of the Kα emission in a solid-density aluminium target, produced when the FEL photon energy is tuned below the Al K-edge, but is resonant with the Kα transition.

  8. The Thermal Regulation of Gravitational Instabilities in Protoplanetary Disks III. Simulations with Radiative Cooling and Realistic Opacities

    CERN Document Server

    Boley, A C; Durisen, R H; Cai, K; Pickett, M K; D'Alessio, P

    2006-01-01

    This paper presents a fully three-dimensional radiative hydrodymanics simulation with realistic opacities for a gravitationally unstable 0.07 Msun disk around a 0.5 Msun star. We address the following aspects of disk evolution: the strength of gravitational instabilities under realistic cooling, mass transport in the disk that arises from GIs, comparisons between the gravitational and Reynolds stresses measured in the disk and those expected in an alpha-disk, and comparisons between the SED derived for the disk and SEDs derived from observationally determined parameters. The mass transport in this disk is dominated by global modes, and the cooling times are too long to permit fragmentation for all radii. Moreover, our results suggest a plausible explanation for the FU Ori outburst phenomenon.

  9. Magnetized Epsilon-Near-Zero (ENZ) Structures: Hall Opacity, Hall Transparency, and One-Way Photonic Surface States

    CERN Document Server

    Davoyan, Arthur

    2013-01-01

    We study propagation of transverse-magnetic (TM) electromagnetic waves in the bulk and at the surface of magnetized epsilon-near-zero (ENZ) medium in a Voigt configuration. We reveal that in a certain range of material parameters novel regimes of wave propagation emerge: we show that the transparency of the medium can be altered with the magnetization leading either to magnetically induced Hall opacity or Hall transparency of the ENZ. In our theoretical study, we demonstrate that surface waves at the interface between either a transparent or an opaque Hall medium and a homogeneous medium may, under certain conditions, be predominantly one-way. Moreover, we predict that one-way photonic surface states may exist at the interface of an opaque Hall ENZ and a regular metal, giving rise to a possibility for backscattering immune wave propagation and isolation.

  10. Properties of the Products Formed by the Activity of Serum Opacity Factor against Human Plasma High Density Lipoproteins

    Science.gov (United States)

    Pownall, Henry J.; Courtney, Harry S.; Gillard, Baiba K.; Massey, John B.

    2010-01-01

    Serum opacity factor from Streptococcus pyogenes transfers the cholesteryl esters (CE) of ~100,000 plasma high density lipoprotein particles (HDL) to a CE-rich microemulsion (CERM) while forming neo HDL, a cholesterol-poor HDL-like particle. HDL, neo HDL, and CERM are distinct. Neo HDL is lower in free cholesterol and has lower surface and total microviscosities than HDL; the surface polarity of neo HDL and HDL are similar. CERM is much larger than HDL and richer in cholesterol and CE. Although the surface microviscosity of HDL is higher than that of CERM, they have similar total microviscosities because cholesterol partitions into the neutral lipid core. Because of its unique surface properties apo E preferentially associates with the CERM. In contrast, the composition and properties of neo HDL make it a potential acceptor of cellular cholesterol and its esterification. Thus, neo HDL and CERM are possible vehicles for improving cholesterol transport to the liver. PMID:18838065

  11. Properties of the products formed by the activity of serum opacity factor against human plasma high-density lipoproteins.

    Science.gov (United States)

    Pownall, Henry J; Courtney, Harry S; Gillard, Baiba K; Massey, John B

    2008-11-01

    Serum opacity factor from Streptococcus pyogenes transfers the cholesteryl esters (CE) of approximately 100,000 plasma high-density lipoprotein particles (HDL) to a CE-rich microemulsion (CERM) while forming neo HDL, a cholesterol-poor HDL-like particle. HDL, neo HDL, and CERM are distinct. Neo HDL is lower in free cholesterol and has lower surface and total microviscosities than HDL; the surface polarity of neo HDL and HDL are similar. CERM is much larger than HDL and richer in cholesterol and CE. Although the surface microviscosity of HDL is higher than that of CERM, they have similar total microviscosities because cholesterol partitions into the neutral lipid core. Because of its unique surface properties apo E preferentially associates with the CERM. In contrast, the composition and properties of neo HDL make it a potential acceptor of cellular cholesterol and its esterification. Thus, neo HDL and CERM are possible vehicles for improving cholesterol transport to the liver.

  12. The microwave opacity of ammonia and water vapor: Application to remote sensing of the atmosphere of Jupiter

    Science.gov (United States)

    Hanley, Thomas Ryan

    2008-06-01

    The object of this research program has been to provide a baseline for microwave remote sensing of ammonia and water vapor in the atmosphere of Jupiter through laboratory measurements of their microwave absorption properties. Jupiter is not only the largest planet in our solar system, but one of the most interesting and complex. Despite a handful of spacecraft missions and many astronomical measurements, much of Jupiter's atmospheric dynamics and composition remain a mystery. Although constraints have been formed on the amount of certain gases present, the global abundances and distributions of water vapor (H 2 O) and ammonia (NH 3 ) are relatively unknown. Measurements of H 2 O and NH 3 in the Jovian atmosphere to hundreds of bars of pressure are best accomplished via passive microwave emission measurements. For these measurements to be accurately interpreted, however, the hydrogen and helium pressure-broadened microwave opacities of H 2 O and NH 3 must be well characterized, a task that is very difficult if based solely on theory and limited laboratory measurements. Therefore, accurate laboratory measurements have been taken under a broad range of conditions that mimic those of the Jovian atmosphere. These measurements, performed using a newly redesigned high- accuracy system, and the corresponding models of microwave opacity that have been developed from them comprise the majority of this work. The models allow more accurate retrievals of H 2 O and NH 3 abundances from previous as well as future missions to Jupiter and the outer planets, such as the NASA New Frontiers class Juno mission scheduled for launch in 2011. This information will enable a greater understanding of the concentration and distribution of H 2 O and NH 3 in the Jovian atmosphere, which will reveal much about how Jupiter and our solar system formed and how similar planets could form in other solar systems, even planets that may be hospitable to life.

  13. Correlation between contrast sensitivity and the lens opacities classification system Ⅲ in age-related nuclear and cortical cataracts

    Institute of Scientific and Technical Information of China (English)

    CHENG Yong; SHI Xuan; CAO Xiao-guang; LI Xiao-xin; BAO Yong-zhen

    2013-01-01

    Background Contrast sensitivity (CS) testing can detect differences in functional vision and is highly correlated with visual performance.This study was designed to investigate the association between CS and the grading score using the lens opacities classification system (LOCS) Ⅲ as well as the association between CS and visual acuity (VA) in nuclear or cortical age-related cataract (ARC) patients.Methods A total of 270 eyes with ARC and 30 control eyes were divided into nuclear opacity (NO),nuclear color (NC),cortical cataract (C) based on LOCS Ⅲ.The CS values measured at all spatial frequencies under photopic and glare conditions that resulted in contrast sensitivity function (CSF) were evaluated,and LogMAR VA was tested with the Early Treatment Diabetic Retinopathy Study (ETDRS) chart.The correlation between CSF and LOCS Ⅲ grading scores,and between CSF and LogMAR VA were analyzed.Results Compared to the controls,CSF of the nuclear or cortical ARC significantly declined.There are significant correlation between CSF and LogMAR VA,and between CSF and LOCS Ⅲ grading scores.Compared to the VA,a stronger correlation existed between CSF and LOCS Ⅲ grading score than that of LogMAR VA and LOCS Ⅲ grading score.CS at some spatial frequencies is significantly influenced with LOCS Ⅲ grading score.Conclusions CSF significantly declined with the increasing ARC grading scores.Comparing to VA,CSF reflected the severity of cataract more comprehensively.CS at low spatial frequency is significantly influenced by ARC.Therefore,CS is more precise than VA in assessing the visual function of ARC patients.

  14. TINY SCALE OPACITY FLUCTUATIONS FROM VLBA, MERLIN, AND VLA OBSERVATIONS OF H I ABSORPTION TOWARD 3C 138

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Nirupam; Goss, W. M. [National Radio Astronomy Observatory, 1003 Lopezville Road, Socorro, NM 87801 (United States); Minter, Anthony H. [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944 (United States); Brogan, Crystal L. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Lazio, T. J. W., E-mail: nroy@aoc.nrao.edu [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2012-04-20

    The structure function of opacity fluctuations is a useful statistical tool to study tiny scale structures of neutral hydrogen. Here we present high-resolution observation of H I absorption toward 3C 138, and estimate the structure function of opacity fluctuations from the combined VLA, MERLIN, and VLBA data. The angular scales probed in this work are {approx}10-200 mas (about 5-100 AU). The structure function in this range is found to be well represented by a power law S{sub {tau}}(x) {approx} x{sup {beta}} with index {beta} {approx} 0.33 {+-} 0.07 corresponding to a power spectrum P{sub {tau}}(U) {approx} U{sup -2.33}. This is slightly shallower than the earlier reported power-law index of {approx}2.5-3.0 at {approx}1000 AU to few pc scales. The amplitude of the derived structure function is a factor of {approx}20-60 times higher than the extrapolated amplitude from observation of Cas A at larger scales. On the other hand, extrapolating the AU scale structure function for 3C 138 predicts the observed structure function for Cas A at the pc scale correctly. These results clearly establish that the atomic gas has significantly more structures in AU scales than expected from earlier pc scale observations. Some plausible reasons are identified and discussed here to explain these results. The observational evidence of a shallower slope and the presence of rich small-scale structures may have implications for the current understanding of the interstellar turbulence.

  15. 40 CFR 60.3067 - How must I monitor opacity for air curtain incinerators that burn only wood waste, clean lumber...

    Science.gov (United States)

    2010-07-01

    ... curtain incinerators that burn only wood waste, clean lumber, and yard waste? 60.3067 Section 60.3067... Incinerators That Burn Only Wood Waste, Clean Lumber, and Yard Waste § 60.3067 How must I monitor opacity for air curtain incinerators that burn only wood waste, clean lumber, and yard waste? (a) Use Method 9...

  16. 40 CFR 60.2972 - How must I monitor opacity for air curtain incinerators that burn only wood waste, clean lumber...

    Science.gov (United States)

    2010-07-01

    ... curtain incinerators that burn only wood waste, clean lumber, and yard waste? 60.2972 Section 60.2972... Only Wood Waste, Clean Lumber, and Yard Waste § 60.2972 How must I monitor opacity for air curtain incinerators that burn only wood waste, clean lumber, and yard waste? (a) Use Method 9 of appendix A of...

  17. Prognostic value of the ratio of ground glass opacity on computed tomography in small lung adenocarcinoma: A meta-analysis

    Science.gov (United States)

    Miao, Xiao-Hui; Yao, Yan-Wen; Yuan, Dong-Mei; Lv, Yan-Ling; Zhan, Ping; Lv, Tang-Feng; Liu, Hong-Bing

    2012-01-01

    Introduction Lung cancer is the leading cause of cancer-associated death. In many countries, adenocarcinoma is the most common histologic type in lung cancer. Previously, few factors are identified to be prognostic indicators for the patients with small lung adenocarcinoma. Recently, the ground glass opacity (GGO) area found on high-resolution computed tomography (HRCT) scanning was identified as a prognostic indicator in some studies. But no clear consensus has been defined. Methods The PubMed/MEDLINE, EMBASE, Cochrane library and SpringerLink electronic databases were searched for articles related to ground glass opacity on computed tomography in patients with small lung adenocarcinoma. Data was extracted and analyzed independently by two investigators. An estimate of the hazard ratio (HR) for comparing high GGO ratio with low GGO ratio was extracted. The respective HRs was combined into a pooled HR, and 95% confidence interval (CI) was calculated for each study. The publication heterogeneity was assessed graphically using performing Beggs’ funnel plot. All the statistical tests used in our meta-analysis were performed with STATA version 11. Results Thirteen studies, encompassing 2,027 patients, were included in our meta-analysis. Ten of these studies revealed that the GGO ratio in small lung adenocarcinoma is a good prognostic indicator. Seven studies were combined in a meta-analysis using overall survival (OS) as the end point of interest. The weighted HR of 7 studies was 0.85, with relative 95% CI ranging from 0.78 to 0.93 (P=0.009). For the surgical patient population, the primary endpoint of relapse-free survival (RFS) was superior with high GGO area on computed tomography (The combined HR 0.82, 95% CI 0.74-0.90; P=0.007). Conclusions The result of our meta-analysis suggested that the GGO area measured on HRCT had a prognostic value of overall survival and relapse-free survival in small lung adenocarcinoma. The GGO ratio may be an independent prognostic

  18. Opacity Broadening of $^{13}$CO Linewidths and its Effect on the Variance-Sonic Mach Number Relation

    CERN Document Server

    Correia, Caio; Lazarian, Alex; Ossenkopf, Volker; Stutzki, Jürgen; Kainulainen, Jouni; Kowal, Grzegorz; de Medeiros, José Renan

    2014-01-01

    We study how the estimation of the sonic Mach number ($M_s$) from $^{13}$CO linewidths relates to the actual 3D sonic Mach number. For this purpose we analyze MHD simulations which include post-processing to take radiative transfer effects into account. As expected, we find very good agreement between the linewidth estimated sonic Mach number and the actual sonic Mach number of the simulations for optically thin tracers. However, we find that opacity broadening causes $M_s$ to be overestimated by a factor of ~ 1.16 - 1.3 when calculated from optically thick $^{13}$CO lines. We also find that there is a dependency on the magnetic field: super-Alfv\\'enic turbulence shows increased line broadening as compared with sub-Alfv\\'enic turbulence for all values of optical depth for supersonic turbulence. Our results have implications for the observationally derived sonic Mach number--density standard deviation ($\\sigma_{\\rho/}$) relationship, $\\sigma^2_{\\rho/}=b^2M_s^2$, and the related column density standard deviatio...

  19. Preventative effects of Ginkgo biloba extract (EGb761) on high glucose-cultured opacity of rat lens.

    Science.gov (United States)

    Lu, Qian; Yang, Tingting; Zhang, Mingzhu; Du, Lei; Liu, Ling; Zhang, Nan; Guo, Hao; Zhang, Fan; Hu, Gang; Yin, Xiaoxing

    2014-05-01

    Diabetic cataract is one of the earliest secondary complications of diabetes, and it is characterized by opacification of the eye lens. In this study, we examined the protective effects of Ginkgo biloba extract (EGb761) on rat lenses cultured in high-glucose conditions. The cultured rat lenses were divided into six groups: normal group, high-glucose group, high glucose plus low, medium, and high concentrations of EGb761 groups, and a high glucose plus bendazac lysine group. The activities of antioxidases, aldose reductase, advanced glycosylation end products, transforming growth factor-β2, Smad2/3, E-cadherin, and α-smooth muscle actin were assessed by different methods. Compared with the levels in the high glucose group, EGb761 decreased the intensity of oxidative stress, decreased aldose reductase activation and the level of advanced glycosylation end products, and suppress the transforming growth factor-β2 or Smad pathway activation, further increase the expression of E-cadherin and decrease α-smooth muscle actin, and therefore, prevents the pathological changes of high glucose-induced lens epithelial cells and ameliorated lens opacity. These results suggest that EGb761 has protective effects on several pharmacological targets in the progress of diabetic cataract and is a potential drug for the prevention of diabetic cataract.

  20. Dust evolution in the transition towards the denser ISM: impact on dust temperature, opacity, and spectral index

    CERN Document Server

    Köhler, Melanie; Jones, Anthony P

    2015-01-01

    Variations in the observed dust emission and extinction indicate a systematic evolution of grain properties in the transition from the diffuse interstellar medium (ISM) to denser molecular clouds. The differences in the dust spectral energy distribution (SED) observed from the diffuse ISM to denser regions, namely an increase in the spectral index at long wavelengths, an increase in the FIR opacity, and a decrease in temperature, are usually assumed to be the result of changes in dust properties. We investigate if evolutionary processes, such as coagulation and accretion, are able to change the dust properties of grains in a way that is consistent with observations. We use a core-mantle grain model to describe diffuse ISM-type grains, and using DDA we calculate how the accretion of mantles and coagulation into aggregates vary the grain optical properties. We calculate the dust SED and extinction using DustEM and the radiative transfer code CRT. We show that the accretion of an aliphatic carbon mantle on diffu...

  1. The Design and Implementation of Mobile OPAC System Based on JQuery Mobile%基于JQuery Mobile的移动OPAC系统的设计与实现

    Institute of Scientific and Technical Information of China (English)

    朱妍

    2014-01-01

    分析了JQuery Mobile的技术特点以及目前国内移动图书馆OPAC系统发展现状,以广东省科技图书馆为例,探讨了基于JQuery Mobile技术的移动OPAC系统的设计和实现过程。%This paper analyzes the technical characteristics of JQuery Mobile and the current development status of mobile library’s OPAC system in China, and taking the Science and Technology Library of Guangdong as an example, probes into the design and implementation process of mobile OPAC system based on JQuery mobile technology.

  2. A Generalised Porosity Formalism for Isotropic and Anisotropic Effective Opacity and its Effects on X-ray Line Attenuation in Clumped O Star Winds

    Science.gov (United States)

    Sundqvist, Jon O.; Owocki, Stanley P.; Cohen, David H.; Leutenegger, Maurice A.

    2011-01-01

    We present a generalised formalism for treating the porosity-associated reduction in continuum opacity that occurs when individual clumps in a stochastic medium become optically thick. As in previous work, we concentrate on developing bridging laws between the limits of optically thin and thick clumps. We consider geometries resulting in either isotropic or anisotropic effective opacity, and, in addition to an idealised model in which all clumps have the same local overdensity and scale, we also treat an ensemble of clumps with optical depths set by Markovian statistics. This formalism is then applied to the specific case of bound-free absorption of X- rays in hot star winds, a process not directly affected by clumping in the optically thin limit. We find that the Markov model gives surprisingly similar results to those found previously for the single clump model, suggesting that porous opacity is not very sensitive to details of the assumed clump distribution function. Further, an anisotropic effective opacity favours escape of X-rays emitted in the tangential direction (the venetian blind effect), resulting in a bump of higher flux close to line centre as compared to profiles computed from isotropic porosity models. We demonstrate how this characteristic line shape may be used to diagnose the clump geometry, and we confirm previous results that for optically thick clumping to significantly influence X-ray line profiles, very large porosity lengths, defined as the mean free path between clumps, are required. Moreover, we present the first X-ray line profiles computed directly from line-driven instability simulations using a 3-D patch method, and find that porosity effects from such models also are very small. This further supports the view that porosity has, at most, a marginal effect on X-ray line diagnostics in O stars, and therefore that these diagnostics do indeed provide a good clumping insensitive method for deriving O star mass-loss rates.

  3. On the necessity of composition-dependent low-temperature opacity in models of metal-poor asymptotic giant branch stars

    Energy Technology Data Exchange (ETDEWEB)

    Constantino, Thomas; Campbell, Simon; Lattanzio, John [Monash Centre for Astrophysics, School of Mathematical Sciences, Monash University, Victoria 3800 (Australia); Gil-Pons, Pilar, E-mail: thomas.constantino@monash.edu [Department of Applied Physics, Polytechnic University of Catalonia, 08860 Barcelona (Spain)

    2014-03-20

    The vital importance of composition-dependent low-temperature opacity in low-mass (M ≤ 3 M {sub ☉}) asymptotic giant branch (AGB) stellar models of metallicity Z ≥ 0.001 has recently been demonstrated. Its significance to more metal-poor, intermediate-mass (M ≥ 2.5 M {sub ☉}) models has yet to be investigated. We show that its inclusion in lower-metallicity models ([Fe/H] ≤–2) is essential and that there exists no threshold metallicity below which composition-dependent molecular opacity may be neglected. We find it to be crucial in all intermediate-mass models investigated ([Fe/H] ≤–2 and 2.5 ≤ M/M {sub ☉} ≤ 5), because of the evolution of the surface chemistry, including the orders of magnitude increase in the abundance of molecule-forming species. Its effect on these models mirrors that previously reported for higher-metallicity models—increase in radius, decrease in T {sub eff}, faster mass loss, shorter thermally pulsing AGB lifetime, reduced enrichment in third dredge-up products (by a factor of 3-10), and an increase in the mass limit for hot bottom burning. We show that the evolution of low-metallicity models with composition-dependent low-temperature opacity is relatively independent of initial metal abundance because its contribution to the opacity is far outweighed by changes resulting from dredge-up. Our results imply a significant reduction in the expected number of nitrogen-enhanced metal-poor stars, which may help explain their observed paucity. We note that these findings are partially a product of the macrophysics adopted in our models, in particular, the Vassiliadis and Wood mass loss rate which is strongly dependent on radius.

  4. Large-scale opacity fluctuations in the Lyα forest: evidence for QSOs dominating the ionizing UV background at z ∼ 5.5-6?

    Science.gov (United States)

    Chardin, Jonathan; Puchwein, Ewald; Haehnelt, Martin G.

    2017-03-01

    Lyα forest data probing the post-reionization Universe show surprisingly large opacity fluctuations over rather large (≥50 h-1 comoving Mpc) spatial scales. We model these fluctuations using a hybrid approach utilizing the large-volume Millennium simulation to predict the spatial distribution of QSOs combined with smaller scale full hydrodynamical simulation performed with RAMSES and post-processed with the radiative transfer code ATON. We produce realistic mock absorption spectra that account for the contribution of galaxies and QSOs to the ionizing UV background. These improved models confirm our earlier findings that a significant ( ≳ 50 per cent) contribution of ionizing photons from QSOs can explain the large reported opacity fluctuations on large scales. The inferred QSO luminosity function is thereby consistent with recent estimates of the space density of QSOs at this redshift. Our simulations still somewhat struggle, however, to reproduce the very long (110 h-1 comoving Mpc) high-opacity absorption through observed in ULAS J0148+0600, perhaps suggesting an even later end of reionization than assumed in our previously favoured model. Medium-deep/medium area QSO surveys as well as targeted searches for the predicted strong transverse QSO proximity effect would illuminate the origin of the observed large-scale opacity fluctuations. They would allow us to substantiate whether UV fluctuations due to QSO are indeed primarily responsible, or whether significant contributions from other recently proposed mechanisms such as large-scale fluctuations in temperature and mean free path (even in the absence of rare bright sources) are required.

  5. Effects of Silicone Hydrogel Contact Lens Application on Corneal High-order Aberration and Visual Guality in Patients with Corneal Opacities

    Directory of Open Access Journals (Sweden)

    Sevda Aydın Kurna

    2012-03-01

    Full Text Available Pur po se: Evaluation of the corneal high-order aberrations and visual quality changes after application of silicone hydrogel contact lenses in patients with corneal opacities due to various etiologies. Ma te ri al and Met hod: Fifteen eyes of 13 patients with corneal opacities were included in the study. During the ophthalmologic examination before and after contact lens application, visual acuity was measured with Snellen acuity chart and contrast sensitivity - with Bailey-Lowie Charts in letters. Aberrations were measured with corneal aberrometer (NIDEK Magellan Mapper under a naturally dilated pupil. Spherical aberration, coma, trefoil, irregular astigmatism and total high-order root mean square (RMS values were recorded. Measurements were repeated with balafilcon A lenses (PureVision 2 HD, B&L on all patients. Re sults: Patient age varied between 23 and 50 years. Two eyes had subepithelial infiltrates due to adenoviral keratitis, 1 had nebulae due to previous infections or trauma, and 2 had Salzmann’s nodular degeneration. We observed a mean increase of 1 line in visual acuity and 5 letters in contrast sensitivity with contact lenses versus glasses in the patients. Mean RMS values of spherical aberration, irregular astigmatism and total high-order aberrations decreased significantly with contact lenses. Dis cus si on: Silicone hydrogel soft contact lenses may improve visual quality by decreasing the corneal aberrations in patients with corneal opacities. (Turk J Ophthalmol 2012; 42: 97-102

  6. Improvement of the Bovine Corneal Opacity and Permeability (BCOP) assay as an in vitro alternative to the Draize rabbit eye irritation test.

    Science.gov (United States)

    Verstraelen, Sandra; Jacobs, An; De Wever, Bart; Vanparys, Philippe

    2013-06-01

    Measurement of ocular irritancy is a necessary step in the safety evaluation of both industrial and consumer products. Assessment of the acute eye irritation potential is therefore part of the international regulatory requirements for testing of chemicals. The Bovine Corneal Opacity and Permeability (BCOP) assay is generally accepted as a valid in vitro alternative method to the Draize eye irritation test to detect corrosive and severe eye irritants (category 1), but has not proven sensitive enough to discriminate accurately moderate (category 2A/2B) to mild and non-irritating compounds. In the currently accepted BCOP assay, opacity is determined by the amount of light transmission through the cornea, and permeability is determined by the amount of sodium fluorescein dye that passes through all corneal cell layers. Both measurements are used to assign an In Vitro Irritancy Score (IVIS) for prediction of the in vivo ocular irritation potential of a test substance. Nowadays, opacity is measured by an OP-KIT opacitometer providing a center-weighted reading of light transmission by measuring changes in voltage when the transmission of white light passes through the cornea alters. As a consequence, this may underestimate opacity that develops as spots or heterogeneous opaque areas on the periphery of an isolated cornea. A prototype of a laser light-based opacitometer (PLLBO) allowing better measurement of opacities was developed by Van Goethem et al. (2010). This new device showed improved sensitivity to detect subtle changes in corneal transparency. Furthermore, the new opacitometer allowed the analysis of the complete corneal surface and was able to detect more efficiently opaque spots located along the sides of the excised corneas. A further improved prototype of the PLLBO was constructed in combination with a camera and a speckle noise reducer. Treatment conditions of the corneas in the cornea holders were optimized in order to mimic more the real in vivo situation

  7. Simultaneous Cartography of Aerosol Opacity and Surface Albedo of Titan by the Massive Inversion of the Cassini/VIMS Dataset

    Science.gov (United States)

    Rodriguez, S.; Maltagliati, L.; Sotin, C.; Rannou, P.; Cornet, T.; Hirtzig, M.; Appéré, T.; Solomonidou, A.; Le Mouelic, S.; Coustenis, A.; Brown, R. H.

    2015-12-01

    Mapping Titan's surface albedo is a necessary step to give reliable constraints on its composition. However, surface albedo maps of Titan, especially over large regions, are still very rare, the surface windows being strongly affected by atmospheric effects (absorption, scattering). A full radiative transfer model is an essential tool to remove these effects, but too time-consuming to treat systematically the ~40000 hyperspectral images VIMS acquired since the beginning of the mission. We developed a massive inversion of VIMS data based on lookup tables computed from a state-of-the-art radiative transfer model (Hirtzig et al. 2013), updated with new aerosol properties coming from our analysis of the Emission Phase Function observation acquired recently by VIMS. Once the physical properties of gases, aerosols and surface are fixed, the lookup tables are built for the remaining free parameters: the incidence, emergence and azimuth angles, given by navigation; and two products (the aerosol opacity and the surface albedo at all wavelengths). The lookup table grid was carefully selected after thorough testing. The data inversion on these pre-computed spectra (opportunely interpolated) is more than 1000 times faster than recalling the full radiative transfer at each minimization step. We present here the results from selected flybys. We invert mosaics composed by couples of flybys observing the same area at two different times. The composite albedo maps do not show significant discontinuities in any of the surface windows, suggesting a robust correction of the effects of the geometry (and thus the aerosols) on the observations. Maps of aerosol and albedo uncertainties are also provided, with the absolute error on the albedo being approximately between 1 and 3% (depending on the surface window considered). We are thus able to provide for the first time ever reliable surface albedo maps at pixel scale for the whole VIMS spectral range.

  8. Automatic segmentation of ground-glass opacities in lung CT images by using Markov random field-based algorithms.

    Science.gov (United States)

    Zhu, Yanjie; Tan, Yongqing; Hua, Yanqing; Zhang, Guozhen; Zhang, Jianguo

    2012-06-01

    Chest radiologists rely on the segmentation and quantificational analysis of ground-glass opacities (GGO) to perform imaging diagnoses that evaluate the disease severity or recovery stages of diffuse parenchymal lung diseases. However, it is computationally difficult to segment and analyze patterns of GGO while compared with other lung diseases, since GGO usually do not have clear boundaries. In this paper, we present a new approach which automatically segments GGO in lung computed tomography (CT) images using algorithms derived from Markov random field theory. Further, we systematically evaluate the performance of the algorithms in segmenting GGO in lung CT images under different situations. CT image studies from 41 patients with diffuse lung diseases were enrolled in this research. The local distributions were modeled with both simple and adaptive (AMAP) models of maximum a posteriori (MAP). For best segmentation, we used the simulated annealing algorithm with a Gibbs sampler to solve the combinatorial optimization problem of MAP estimators, and we applied a knowledge-guided strategy to reduce false positive regions. We achieved AMAP-based GGO segmentation results of 86.94%, 94.33%, and 94.06% in average sensitivity, specificity, and accuracy, respectively, and we evaluated the performance using radiologists' subjective evaluation and quantificational analysis and diagnosis. We also compared the results of AMAP-based GGO segmentation with those of support vector machine-based methods, and we discuss the reliability and other issues of AMAP-based GGO segmentation. Our research results demonstrate the acceptability and usefulness of AMAP-based GGO segmentation for assisting radiologists in detecting GGO in high-resolution CT diagnostic procedures.

  9. Value of window technique in diagnosis of the ground glass opacities in patients with non-small cell pulmonary cancer.

    Science.gov (United States)

    Yao, Gang

    2016-11-01

    The aim of the present study was to examine the value of window technique in qualitative diagnosis of the ground glass opacities (GGO) in patients with non-small cell pulmonary cancer. A total of 124 clinically suspected pulmonary cancer patients were analyzed retrospectively. The lesions were affirmed by puncture biopsy, and were GGO on pulmonary window while were invisible on mediastinal window. Sixty-four multi-detector spiral computed tomography with the window width and window level of 1,500 Hounsfield units (HU) and -450 HU on pulmonary window, while the window width and window level of 400 and 40 HU on mediastinal window, was used in the study. The window adjustment technique was used to analyze the window width and window level of lesion on pulmonary window and mediastinal window, for searching invisible threshold on 3-megapixel medical displays. The diagnostic accuracy and the cut-off value were compared on receiver operating characteristic (ROC) curve. The results showed that the window width and window level on pulmonary window and mediastinal window of malignant lesions were significantly less than those of benign ones (Pvalue on pulmonary window was the window width and window level of 1,300 and -220 HU, the area under the ROC was 0.830 [sensitivity was 72.5%, specificity was 84.3%; 95% confidence interval (CI), 0.712-0.945]. The cut-off value on mediastinal window was the window width and window level of 360 and 30 HU, and the area under the ROC was 0.623 (was 62.0%, specificity was 55.7%; 95% CI, 0.541-0.745). In conclusion, the window technique has high sensitivity and accuracy in qualitative diagnosis of the GGO.

  10. Dust models post-Planck: constraining the far-infrared opacity of dust in the diffuse interstellar medium

    Science.gov (United States)

    Fanciullo, L.; Guillet, V.; Aniano, G.; Jones, A. P.; Ysard, N.; Miville-Deschênes, M.-A.; Boulanger, F.; Köhler, M.

    2015-08-01

    Aims: We compare the performance of several dust models in reproducing the dust spectral energy distribution (SED) per unit extinction in the diffuse interstellar medium (ISM). We use our results to constrain the variability of the optical properties of big grains in the diffuse ISM, as published by the Planck collaboration. Methods: We use two different techniques to compare the predictions of dust models to data from the Planck HFI, IRAS, and SDSS surveys. First, we fit the far-infrared emission spectrum to recover the dust extinction and the intensity of the interstellar radiation field (ISRF). Second, we infer the ISRF intensity from the total power emitted by dust per unit extinction, and then predict the emission spectrum. In both cases, we test the ability of the models to reproduce dust emission and extinction at the same time. Results: We identify two issues. Not all models can reproduce the average dust emission per unit extinction: there are differences of up to a factor ~2 between models, and the best accord between model and observation is obtained with the more emissive grains derived from recent laboratory data on silicates and amorphous carbons. All models fail to reproduce the variations in the emission per unit extinction if the only variable parameter is the ISRF intensity: this confirms that the optical properties of dust are indeed variable in the diffuse ISM. Conclusions: Diffuse ISM observations are consistent with a scenario where both ISRF intensity and dust optical properties vary. The ratio of the far-infrared opacity to the V band extinction cross-section presents variations of the order of ~20% (40-50% in extreme cases), while ISRF intensity varies by ~30% (~60% in extreme cases). This must be accounted for in future modelling. Appendices are available in electronic form at http://www.aanda.org

  11. Apolipoprotein AI deficiency inhibits serum opacity factor activity against plasma high density lipoprotein via a stabilization mechanism.

    Science.gov (United States)

    Rosales, Corina; Patel, Niket; Gillard, Baiba K; Yelamanchili, Dedipya; Yang, Yaliu; Courtney, Harry S; Santos, Raul D; Gotto, Antonio M; Pownall, Henry J

    2015-04-14

    The reaction of Streptococcal serum opacity factor (SOF) against plasma high-density lipoproteins (HDL) produces a large cholesteryl ester-rich microemulsion (CERM), a smaller neo HDL that is apolipoprotein (apo) AI-poor, and lipid-free apo AI. SOF is active versus both human and mouse plasma HDL. In vivo injection of SOF into mice reduces plasma cholesterol ∼40% in 3 h while forming the same products observed in vitro, but at different ratios. Previous studies supported the hypothesis that labile apo AI is required for the SOF reaction vs HDL. Here we further tested that hypothesis by studies of SOF against HDL from apo AI-null mice. When injected into apo AI-null mice, SOF reduced plasma cholesterol ∼35% in 3 h. The reaction of SOF vs apo AI-null HDL in vitro produced a CERM and neo HDL, but no lipid-free apo. Moreover, according to the rate of CERM formation, the extent and rate of the SOF reaction versus apo AI-null mouse HDL were less than that against wild-type (WT) mouse HDL. Chaotropic perturbation studies using guanidine hydrochloride showed that apo AI-null HDL was more stable than WT HDL. Human apo AI added to apo AI-null HDL was quantitatively incorporated, giving reconstituted HDL. Both SOF and guanidine hydrochloride displaced apo AI from the reconstituted HDL. These results support the conclusion that apo AI-null HDL is more stable than WT HDL because it lacks apo AI, a labile protein that is readily displaced by physicochemical and biochemical perturbations. Thus, apo AI-null HDL is less SOF-reactive than WT HDL. The properties of apo AI-null HDL can be partially restored to those of WT HDL by the spontaneous incorporation of human apo AI. It remains to be determined what other HDL functions are affected by apo AI deletion.

  12. Streptococcal serum opacity factor promotes cholesterol ester metabolism and bile acid secretion in vitro and in vivo.

    Science.gov (United States)

    Gillard, Baiba K; Rodriguez, Perla J; Fields, David W; Raya, Joe L; Lagor, William R; Rosales, Corina; Courtney, Harry S; Gotto, Antonio M; Pownall, Henry J

    2016-03-01

    Plasma high density lipoprotein-cholesterol (HDL-C) concentrations negatively correlate with atherosclerotic cardiovascular disease. HDL is thought to have several atheroprotective functions, which are likely distinct from the epidemiological inverse relationship between HDL-C levels and risk. Specifically, strategies that reduce HDL-C while promoting reverse cholesterol transport (RCT) may have therapeutic value. The major product of the serum opacity factor (SOF) reaction versus HDL is a cholesteryl ester (CE)-rich microemulsion (CERM), which contains apo E and the CE of ~400,000 HDL particles. Huh7 hepatocytes take up CE faster when delivered as CERM than as HDL, in part via the LDL-receptor (LDLR). Here we compared the final RCT step, hepatic uptake and subsequent intracellular processing to cholesterol and bile salts for radiolabeled HDL-, CERM- and LDL-CE by Huh7 cells and in vivo in C57BL/6J mice. In Huh7 cells, uptake from LDL was greater than from CERM (2-4X) and HDL (5-10X). Halftimes for [(14)C]CE hydrolysis were 3.0±0.2, 4.4±0.6 and 5.4±0.7h respectively for HDL, CERM and LDL-CE. The fraction of sterols secreted as bile acids was ~50% by 8h for all three particles. HDL, CERM and LDL-CE metabolism in mice showed efficient plasma clearance of CERM-CE, liver uptake and metabolism, and secretion as bile acids into the gall bladder. This work supports the therapeutic potential of the SOF reaction, which diverts HDL-CE to the LDLR, thereby increasing hepatic CE uptake, and sterol disposal as bile acids. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Streptococcal serum opacity factor increases the rate of hepatocyte uptake of human plasma high-density lipoprotein cholesterol.

    Science.gov (United States)

    Gillard, Baiba K; Rosales, Corina; Pillai, Biju K; Lin, Hu Yu; Courtney, Harry S; Pownall, Henry J

    2010-11-16

    Serum opacity factor (SOF), a virulence determinant of Streptococcus pyogenes, converts plasma high-density lipoproteins (HDL) to three distinct species: lipid-free apolipoprotein (apo) A-I, neo HDL, a small discoidal HDL-like particle, and a large cholesteryl ester-rich microemulsion (CERM) that contains the cholesterol esters (CE) of up to ∼400000 HDL particles and apo E as its major protein. Similar SOF reaction products are obtained with HDL, total plasma lipoproteins, and whole plasma. We hypothesized that hepatic uptake of CERM-CE via multiple apo E-dependent receptors would be faster than that of HDL-CE. We tested our hypothesis using human hepatoma cells and lipoprotein receptor-specific Chinese hamster ovary (CHO) cells. The uptake of [(3)H]CE by HepG2 and Huh7 cells from HDL after SOF treatment, which transfers >90% of HDL-CE to CERM, was 2.4 and 4.5 times faster, respectively, than from control HDL. CERM-[(3)H]CE uptake was inhibited by LDL and HDL, suggestive of uptake by both the LDL receptor (LDL-R) and scavenger receptor class B type I (SR-BI). Studies in CHO cells specifically expressing LDL-R and SR-BI confirmed CERM-[(3)H]CE uptake by both receptors. RAP and heparin inhibit CERM-[(3)H]CE but not HDL-[(3)H]CE uptake, thereby implicating LRP-1 and cell surface proteoglycans in this process. These data demonstrate that SOF treatment of HDL increases the rate of CE uptake via multiple hepatic apo E receptors. In so doing, SOF might increase the level of hepatic disposal of plasma cholesterol in a way that is therapeutically useful.

  14. Serum opacity factor unmasks human plasma high-density lipoprotein instability via selective delipidation and apolipoprotein A-I desorption.

    Science.gov (United States)

    Gillard, Baiba K; Courtney, Harry S; Massey, John B; Pownall, Henry J

    2007-11-13

    Human plasma high-density lipoproteins (HDL) are important vehicles in reverse cholesterol transport, the cardioprotective mechanism by which peripheral tissue-cholesterol is transported to the liver for disposal. HDL is the target of serum opacity factor (SOF), a substance produced by Streptococcus pyogenes that turns mammalian serum cloudy. Using a recombinant (r) SOF, we studied opacification and its mechanism. rSOF catalyzes the partial disproportionation of HDL into a cholesteryl ester-rich microemulsion (CERM) and a new HDL-like particle, neo HDL, with the concomitant release of lipid-free (LF)-apo A-I. Opacification is unique; rSOF transfers apo E and nearly all neutral lipids of approximately 100,000 HDL particles into a single large CERM whose size increases with HDL-CE content (r approximately 100-250 nm) leaving a neo HDL that is enriched in PL (41%) and protein (48%), especially apo A-II. rSOF is potent; within 30 min at 37 degrees C, 10 nM rSOF opacifies 4 microM HDL. At respective low and high physiological HDL concentrations, LF-apo A-I is monomeric and tetrameric. CERM formation and apo A-I release have similar kinetics suggesting parallel or rapid sequential steps. According to the reaction products and kinetics, rSOF is a heterodivalent fusogenic protein that uses a docking site to displace apo A-I and bind to exposed CE surfaces on HDL; the resulting rSOF-HDL complex recruits additional HDL with its binding-delipidation site and through multiple fusion steps forms a CERM. rSOF may be a clinically useful and novel modality for improving reverse cholesterol transport. With apo E and a high CE content, CERM could transfer large amounts of cholesterol to the liver for disposal via the LDL receptor; neo HDL is likely a better acceptor of cellular cholesterol than HDL; LF-apo A-I could enhance efflux via the ATP-binding casette transporter ABCA1.

  15. Disruption of human plasma high-density lipoproteins by streptococcal serum opacity factor requires labile apolipoprotein A-I.

    Science.gov (United States)

    Han, Mikyung; Gillard, Baiba K; Courtney, Harry S; Ward, Kathryn; Rosales, Corina; Khant, Htet; Ludtke, Steven J; Pownall, Henry J

    2009-02-24

    Human plasma high-density lipoproteins (HDL), the primary vehicle for reverse cholesterol transport, are the target of serum opacity factor (SOF), a virulence determinant of Streptococcus pyogenes that turns serum opaque. HDL comprise a core of neutral lipidscholesteryl esters and some triglyceridesurrounded by a surface monolayer of cholesterol, phospholipids, and specialized proteins [apolipoproteins (apos) A-I and A-II]. A HDL is an unstable particle residing in a kinetic trap from which it can escape via chaotropic, detergent, or thermal perturbation. Recombinant (r) SOF catalyzes the transfer of nearly all neutral lipids of approximately 100,000 HDL particles (D approximately 8.5 nm) into a single, large cholesteryl ester-rich microemulsion (CERM; D > 100 nm), leaving a new HDL-like particle [neo HDL (D approximately 5.8 nm)] while releasing lipid-free (LF) apo A-I. CERM formation and apo A-I release have similar kinetics, suggesting parallel or rapid consecutive steps. By using complementary physicochemical methods, we have refined the mechanistic model for HDL opacification. According to size exclusion chromatography, a HDL containing nonlabile apo A-I resists rSOF-mediated opacification. On the basis of kinetic cryo-electron microscopy, rSOF (10 nM) catalyzes the conversion of HDL (4 microM) to neo HDL via a stepwise mechanism in which intermediate-sized particles are seen. Kinetic turbidimetry revealed opacification as a rising exponential reaction with a rate constant k of (4.400 +/- 0.004) x 10(-2) min(-1). Analysis of the kinetic data using transition state theory gave an enthalpy (DeltaH()), entropy (DeltaS(++)), and free energy (DeltaG()) of activation of 73.9 kJ/mol, -66.87 J/K, and 94.6 kJ/mol, respectively. The free energy of activation for opacification is nearly identical to that for the displacement of apo A-I from HDL by guanidine hydrochloride. We conclude that apo A-I lability is required for HDL opacification, LF apo A-I desorption is the

  16. Evaluation of the efficiency and accuracy of new methods for atmospheric opacity and radiative transfer calculations in planetary general circulation model simulations

    Science.gov (United States)

    Zube, Nicholas Gerard; Zhang, Xi; Natraj, Vijay

    2016-10-01

    General circulation models often incorporate simple approximations of heating between vertically inhomogeneous layers rather than more accurate but computationally expensive radiative transfer (RT) methods. With the goal of developing a GCM package that can model both solar system bodies and exoplanets, it is vital to examine up-to-date RT models to optimize speed and accuracy for heat transfer calculations. Here, we examine a variety of interchangeable radiative transfer models in conjunction with MITGCM (Hill and Marshall, 1995). First, for atmospheric opacity calculations, we test gray approximation, line-by-line, and correlated-k methods. In combination with these, we also test RT routines using 2-stream DISORT (discrete ordinates RT), N-stream DISORT (Stamnes et al., 1988), and optimized 2-stream (Spurr and Natraj, 2011). Initial tests are run using Jupiter as an example case. The results can be compared in nine possible configurations for running a complete RT routine within a GCM. Each individual combination of opacity and RT methods is contrasted with the "ground truth" calculation provided by the line-by-line opacity and N-stream DISORT, in terms of computation speed and accuracy of the approximation methods. We also examine the effects on accuracy when performing these calculations at different time step frequencies within MITGCM. Ultimately, we will catalog and present the ideal RT routines that can replace commonly used approximations within a GCM for a significant increase in calculation accuracy, and speed comparable to the dynamical time steps of MITGCM. Future work will involve examining whether calculations in the spatial domain can also be reduced by smearing grid points into larger areas, and what effects this will have on overall accuracy.

  17. Prevalence of and factors associated with lens opacities in a Korean adult population with and without diabetes: the 2008-2009 Korea National Health and Nutrition Examination Survey.

    Directory of Open Access Journals (Sweden)

    Tae Nyun Kim

    Full Text Available OBJECTIVE: We examined the prevalence of and factors associated with lens opacities in a Korean adult population with and without diabetes. RESEARCH DESIGN AND METHODS: Among the 11,163 adults (≥ 19 years old from the fourth Korea National Health and Nutrition Examination Survey in 2008-2009, the data from laboratory tests, nutritional surveys, and slit-lamp examinations of 10,248 persons (4,397 men, 5,851 women were examined. Cataract was defined as the presence of any nuclear, cortical, subcapsular, or mixed cataract in at least one eye, using the Lens Opacities Classification System III. RESULTS: The weighted prevalence of cataracts were 23.5% [95% confidence interval (CI, 21.7-25.4] in a Korean adult population (19-39 years old, 1.8% [1.3-2.5], 40-64 years old, 25.2% [22.5-28.1], ≥ 65 years old, 87.8% [85.4-89.9]and 54.7% [50.1-59.2] in a diabetic population(19-39 years old, 11.6% [4.5-26.5], 40-64 years old, 41.1% [35.4-47.0], ≥ 65 years old, 88.3% [83.5-91.8]. In a logistic regression analysis, age, myopia, and the presence of diabetes were independent risk factors. For young (age 19-39 years and middle aged (age 40-65 years adults with diabetes, the OR of having a lens opacity is 5.04 [1.41-17.98] and 1.47 [1.11-1.94], respectively, as those without diabetes, whereas for adults aged 65 and older, there was no difference in the prevalence of cataract. CONCLUSIONS: According to these national survey data, ∼ 24% of Korean adults and ∼ 55% of people with diabetes have cataracts. The presence of diabetes was independently associated with cataracts in young and middle aged adults.

  18. NASA study of cataract in astronauts (NASCA). Report 1: Cross-sectional study of the relationship of exposure to space radiation and risk of lens opacity.

    Science.gov (United States)

    Chylack, Leo T; Peterson, Leif E; Feiveson, Alan H; Wear, Mary L; Manuel, F Keith; Tung, William H; Hardy, Dale S; Marak, Lisa J; Cucinotta, Francis A

    2009-07-01

    The NASA Study of Cataract in Astronauts (NASCA) is a 5-year longitudinal study of the effect of space radiation exposure on the severity/progression of nuclear, cortical and posterior subcapsular (PSC) lens opacities. Here we report on baseline data that will be used over the course of the longitudinal study. Participants include 171 consenting astronauts who flew at least one mission in space and a comparison group made up of three components: (a) 53 astronauts who had not flown in space, (b) 95 military aircrew personnel, and (c) 99 non-aircrew ground-based comparison subjects. Continuous measures of nuclear, cortical and PSC lens opacities were derived from Nidek EAS 1000 digitized images. Age, demographics, general health, nutritional intake and solar ocular exposure were measured at baseline. Astronauts who flew at least one mission were matched to comparison subjects using propensity scores based on demographic characteristics and medical history stratified by gender and smoking (ever/never). The cross-sectional data for matched subjects were analyzed by fitting customized non-normal regression models to examine the effect of space radiation on each measure of opacity. The variability and median of cortical cataracts were significantly higher for exposed astronauts than for nonexposed astronauts and comparison subjects with similar ages (P=0.015). Galactic cosmic space radiation (GCR) may be linked to increased PSC area (P=0.056) and the number of PSC centers (P=0.095). Within the astronaut group, PSC size was greater in subjects with higher space radiation doses (P=0.016). No association was found between space radiation and nuclear cataracts. Cross-sectional data analysis revealed a small deleterious effect of space radiation for cortical cataracts and possibly for PSC cataracts. These results suggest increased cataract risks at smaller radiation doses than have been reported previously.

  19. 会计稳健性、信息不透明与股价暴跌风险%Accounting Conservatism, Information Opacity and Stock Price Crash Risk

    Institute of Scientific and Technical Information of China (English)

    王冲; 谢雅璐

    2013-01-01

    选取2001年至2009年A股数据,从市场信息的角度,通过考察会计稳健性、信息不透明程度与股价暴跌风险三者之间的交互影响,探索会计稳健性与信息环境之间的互动关系,采用Logistic回归和OLS回归模型进行实证分析.研究结果表明,伴随着会计稳健性的提高,公司股价的暴跌风险显著降低,证实会计稳健性作为会计信息质量特征所具有的市场功能;信息不透明程度越高的企业,其股价暴跌风险也越高.进一步考察信息不透明程度对会计稳健性治理效应的影响,发现会计稳健性对于股价暴跌风险的治理作用在信息不透明程度高的公司更加显著,也可以理解为会计稳健性和信息透明度之间可以部分替代.%Selecting data from Chinese A-share companies during 2001 and 2009 as samples, we take market information views to investigate the relationship among the accounting conservatism, information opacity and stock price crash risk, explore the interactive relationship between the conservatism and information environment and use Logistic regression model and OLS regression model for empirical analysis. The results indicate that along with the improvement of accounting conservatism, the stock price crash risk significantly decreases, which proves the market functions of accounting conservatism as accounting information quality characteristics. The stock price crash risk is greater in enterprises with higher degree of information opacity. Our research further examines how the information opacity affects the governance effect of accounting conservatism and we find the governance effect of accounting conservatism on the stock price crash risk is more distinct in enterprises with higher degree of information opacity. In another word, accounting conservatism and information transparency can partially substitute each other.

  20. Uniportal video-assisted thoracic surgery resection of small ground-glass opacities (GGOs) localized with CT-guided placement of microcoils and palpation

    Science.gov (United States)

    Shi, Zhe; Jiang, Sen; Jiang, Gening

    2016-01-01

    Although uniportal video-assisted thoracic surgery (VATS) is becoming more popular, it’s still very challenging to conduct a wedge resection of small pulmonary ground-glass opacities (GGOs), especially deeply situated subpleural GGOs, via uniportal VATS. We successfully performed thirteen uniportal VATS wedge resections through an approach that combines radiologically guided microcoil localization with palpation, and we encountered no complications related to the new approach. Based on our experience, a combination of CT-guided microcoil localization with palpation in uniportal VATS for deeply situated subpleural GGOs is a safe and effective procedure for accurate diag¬nosis and resection of indeterminate GGOs. PMID:27499978

  1. The application of QR Code technology in the library OPAC%二维条码技术在图书馆OPAC中的应用

    Institute of Scientific and Technical Information of China (English)

    蒋南

    2010-01-01

    文章在介绍二维条码QR Code技术特点的基础上,给出了将二维条码技术应用到图书馆联机公共目录查询系统(以下简称OPAC)中的具体实现方案,该方案将OPAC系统中的文本信息转换成QR Code二维条码图像,以方便读者通过手机快速识别、获取并利用这些信息,提升OPAC系统的可用性.

  2. Imaging-guided thoracoscopic resection of a ground-glass opacity lesion in a hybrid operating room equipped with a robotic C-arm CT system.

    Science.gov (United States)

    Hsieh, Chen-Ping; Hsieh, Ming-Ju; Fang, Hsin-Yueh; Chao, Yin-Kai

    2017-05-01

    The intraoperative identification of small pulmonary nodules through video-assisted thoracoscopic surgery remains challenging. Although preoperative CT-guided nodule localization is commonly used to detect tumors during video-assisted thoracoscopic surgery (VATS), this approach carries inherent risks. We report the case of a patient with stage I lung cancer presenting as an area of ground-glass opacity (GGO) in the right upper pulmonary lobe. He successfully underwent a single-stage, CT-guided localization and removal of the pulmonary nodule within a hybrid operating room (OR) equipped with a robotic C-arm.

  3. OPAC读者网摘功能的设计与实现%Design and Implementation of the Readers Social Bookmark Function of OPAC

    Institute of Scientific and Technical Information of China (English)

    黎邦群

    2012-01-01

    为了完善与丰富OPAC的互动性与个性化功能,充分揭示用户对网络信息资源的利用和需求,提升用户的使用体验,需要对网络信息进行收集、利用、挖掘和整理,并构建网摘数据库,在此基础上利用ASP的XMLHTrP组件和数据库的相关技术存储网页快照,从而设计和实现了OPAC读者网摘功能,达到了将网页全文一键收藏的目的。%In order to improve and enrich OPAC and personalized interactivity, reveal user's demand and use of network information and to promote user's using experience, we need to collect, use, arrange the network information and construct webpage excerpts database. On this basis, we can use ASP XMLHTYP components and relevant technology to save webpage snapshots, thus to realize OPAC webpage excerpts function.

  4. A search for line intensity enhancements in the far-UV spectra of active late-type stars arising from opacity

    CERN Document Server

    Keenan, F P; Rose, S J; Mathioudakis, M

    2011-01-01

    Radiative transfer calculations have predicted intensity enhancements for optically thick emission lines, as opposed to the normal intensity reductions, for astrophysical plasmas under certain conditions. In particular, the results are predicted to be dependent both on the geometry of the emitting plasma and the orientation of the observer. Hence in principle the detection of intensity enhancement may provide a way of determining the geometry of an unresolved astronomical source. To investigate such enhancements we have analyzed a sample of active late-type stars observed in the far ultraviolet spectral region. Emission lines of O VI in the FUSE satellite spectra of epsilon Eri, II Peg and Prox Cen were searched for intensity enhancements due to opacity. We have found strong evidence for line intensity enhancements due to opacity during active or flare-like activity for all three stars. The O VI 1032/1038 line intensity ratios, predicted to have a value of 2.0 in the optically thin case, are found to be up to...

  5. What can the 2008/10 broadband flare of PKS 1502+106 tell us? Nuclear opacity, magnetic fields, and the location of gamma rays

    CERN Document Server

    Karamanavis, V; Angelakis, E; Nestoras, I; Myserlis, I; Krichbaum, T P; Zensus, J A; Ungerechts, H; Sievers, A; Gurwell, M A

    2016-01-01

    Context. The origin of blazar variability, seen from radio up to gamma rays, is still a heavily debated matter and broadband flares offer a unique testbed towards a better understanding of these extreme objects. Such an energetic outburst was detected by Fermi/LAT in 2008 from the blazar PKS 1502+106. The outburst was observed from gamma rays down to radio frequencies. Aims. Through the delay between flare maxima at different radio frequencies, we study the frequency-dependent position of the unit-opacity surface and infer its absolute position with respect to the jet base. This nuclear opacity profile enables the magnetic field tomography of the jet. We also localize the gamma-ray emission region and explore the mechanism producing the flare. Methods. The radio flare of PKS 1502+106 is studied through single-dish flux density measurements at 12 frequencies in the range 2.64 to 226.5 GHz. To quantify it, we employ both a Gaussian process regression and a discrete cross-correlation function analysis. Results. ...

  6. The Personalized Configuring Security Strategy of OPAC Retrieval Machine%OPAC检索机安全性能优化研究

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Growing OPAC retrieve machine information security issues for library, a security optimization program based the keywords public key encryption OPAC retrieval machine based on the the original PEKS keyword search encryption technology, learn searchable symmetric encryption technology, the roleis divided into the sender, recipient,and the server, respectively, in the system initialization, the message is sent,the message reception and server retrieval operation optimization. The experimental results show that the program has been greatly improved operational efficiency and safety performance, effective program.%  针对图书馆OPAC检索机信息安全问题日益严重的现状,提出了一种基于关键词公钥加密的OPAC检索机安全优化方案,该方案基于原先PEKS关键词检索加密技术,借鉴可搜索对称加密技术,将角色分为发送者、接收者和服务器,分别在系统初始化、消息发送、消息接收和服务器检索操作时进行优化。实验结果表明,该方案在运行效率和安全性能上得到了很大的提高,方案切实有效。

  7. Forward Modeling of the 2003 November 14 Titan Occultation: New Retrievals of Temperature, Density and Opacity Profiles from about 350 to 500 km

    Science.gov (United States)

    Young, E. F.; Zalucha, A.

    2012-04-01

    On 2003 November 14, Titan occulted a relatively bright star (V = 10.7). This event was observed from La Palma Observatory using ULTRACAM in three simultaneous wavelengths (358, 487 and 758 nm), as reported by Zalucha et al. (2007). The event was near-central, but only the long-wavelength light curves show a central flash. Zalucha et al. (2007) extracted temperature profiles from 350 to 485 km, estimated the altitudes where line-of-sight aerosol optical depths are one in the three ULTRACAM filters and fit the three-peaked central flash feature to atmospheric shape models that are comparable to those used by Hubbard et al. (1993) in the 28 Sgr occultation. We now use a more flexible forward-modeling approach to re-examine the ULTRACAM light curves. The output of this effort is a thin-screen representation of Titan’s upper atmosphere consisting of line-of-sight opacities and phase delays - it is a flexible technique to simultaneously retrieve extinction and refractivity profiles and bulk atmospheric shape. We will present temperature, density and opacity profiles that are consistent with the retrieved thin-screen model and compare model light curves generated from HASI temperature profiles to the occultation observations. References: Zalucha, A., et al.: "The 2003 November 14 occultation by Titan of TYC 1343-1865-1 II. Analysis of light curves". Icarus, Vol. 197, pp. 503-518, 2007.

  8. TU-E-201-01: Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionists

    Energy Technology Data Exchange (ETDEWEB)

    Rehani, M. [Massachusetts General Hospital (United States)

    2015-06-15

    Madan M. Rehani, Massachusetts General Hospital and Harvard Medical School, Boston Methods for Eye Lens Dosimetry and Studies On Lens Opacities with Interventionalists Radiation induced cataract is a major threat among staff working in interventional suites. Nearly 16 million interventional procedures are performed annually in USA. Recent studies by the principal investigator’s group, primarily among interventional cardiologists, on behalf of the International Atomic Energy Agency, show posterior subcapsular (PSC) changes in the eye lens in 38–53% of main operators and 21–45% of support staff. These changes have potential to lead to cataract in future years, as per information from A-Bomb survivors. The International Commission on Radiological Protection has reduced dose limit for staff by a factor of 7.5 (from 150 mSv/y to 20 mSv/y). With increasing emphasis on radiation induced cataracts and reduction in threshold dose for eye lens, there is a need to implement strategies for estimating eye lens dose. Unfortunately eye lens dosimetry is at infancy when it comes to routine application. Various approaches are being tried namely direct measurement using active or passive dosimeters kept close to eyes, retrospective estimations and lastly correlating patient dose in interventional procedures with staff eye dose. The talk will review all approaches available and ongoing active research in this area, as well as data from surveys done in Europe on status of eye dose monitoring in interventional radiology and nuclear medicine. The talk will provide update on how good is Hp(10) against Hp(3), estimations from CTDI values, Monte Carlo based simulations and current status of eye lens dosimetry in USA and Europe. The cataract risk among patients is in CT examinations of the head. Since radiation induced cataract predominantly occurs in posterior sub-capsular (PSC) region and is thus distinguishable from age or drug related cataracts and is also preventable, actions on

  9. Comments on "Including the effects of temperature-dependent opacities in the implicit Monte Carlo algorithm" by N.A. Gentile [J. Comput. Phys. 230 (2011) 5100-5114

    Science.gov (United States)

    Ghosh, Karabi

    2017-02-01

    We briefly comment on a paper by N.A. Gentile [J. Comput. Phys. 230 (2011) 5100-5114] in which the Fleck factor has been modified to include the effects of temperature-dependent opacities in the implicit Monte Carlo algorithm developed by Fleck and Cummings [1,2]. Instead of the Fleck factor, f = 1 / (1 + βcΔtσP), the author derived the modified Fleck factor g = 1 / (1 + βcΔtσP - min [σP‧ (a Tr4 - aT4) cΔt/ρCV, 0 ]) to be used in the Implicit Monte Carlo (IMC) algorithm in order to obtain more accurate solutions with much larger time steps. Here β = 4 aT3 / ρCV, σP is the Planck opacity and the derivative of Planck opacity w.r.t. the material temperature is σP‧ = dσP / dT.

  10. An Empirical Determination of the Intergalactic Background Light Using Near-Infrared Deep Galaxy Survey Data Out to 5 Micrometers and the Gamma-Ray Opacity of the Universe

    Science.gov (United States)

    Scully, Sean T.; Malkan, Matthew A.; Stecker, Floyd W.

    2014-01-01

    We extend our previous model-independent determination of the intergalactic background light, based purely on galaxy survey data, out to a wavelength of 5 micrometers. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. We further determine a 68% confidence upper and lower limit on the opacity of the universe to gamma-rays up to energies of 1.6/(1 + z) terraelectron volts. A comparison of our lower limit redshift-dependent opacity curves to the opacity limits derived from the results of both ground-based air Cerenkov telescope and Fermi-LAT observations of PKS 1424+240 allows us to place a new upper limit on the redshift of this source, independent of IBL modeling.

  11. 新一代开源OPAC的现状调查与问题分析%Status Survey and Problem Analysis for Open Source Software of the New Generation OPAC

    Institute of Scientific and Technical Information of China (English)

    王海英

    2011-01-01

    In the research and practice of the new generation OPAC, the open source software OPAC has played an important role. This paper selected six mature and representative pen source software OPACs as respondent and analyzed three major problems under the stat%在新一代OPAC的研究与实践中,开源OPAC已成为不容忽视的一支力量。本文选取6款较为成熟且具代表性的开源OPAC系统作为调查对象,针对对当前开源OPAC的现状所反映出的3个主要问题进行了分析,并提出了一些想法。

  12. Dust formation and mass loss around intermediate-mass AGB stars with initial metallicity Zini ≤ 10-4 in the early Universe - I. Effect of surface opacity on stellar evolution and the dust-driven wind

    Science.gov (United States)

    Tashibu, Shohei; Yasuda, Yuki; Kozasa, Takashi

    2017-04-01

    Dust formation and the resulting mass loss around asymptotic giant branch (AGB) stars with initial metallicity in the range 0 ≤ Zini ≤ 10-4 and initial mass 2 ≤ Mini/M⊙ ≤ 5 are explored by hydrodynamical calculations of the dust-driven wind (DDW) along the AGB evolutionary tracks. We employ the MESA code to simulate the evolution of stars, assuming an empirical mass-loss rate in the post-main-sequence phase and considering three types of low-temperature opacity (scaled-solar, CO-enhanced and CNO-enhanced opacity) to elucidate the effect on stellar evolution and the DDW. We find that the treatment of low-temperature opacity strongly affects dust formation and the resulting DDW; in the carbon-rich AGB phase, the maximum dot{M} of Mini ≥ 3 M⊙ stars with the CO-enhanced opacity is at least one order of magnitude smaller than that with the CNO-enhanced opacity. A wide range of stellar parameters being covered, the necessary condition for driving efficient DDW with dot{M} ≥ 10^{-6} M⊙ yr-1 is expressed as effective temperature Teff ≲ 3850 K and log (δCL/κRM) ≳ 10.43log Teff - 32.33, with the carbon excess δC defined as εC - εO, the Rosseland mean opacity κR in units of cm2 g-1 in the surface layer and the stellar mass (luminosity) M(L) in solar units. The fitting formulae derived for gas and dust mass-loss rates in terms of input stellar parameters could be useful for investigating the dust yield from AGB stars in the early Universe being consistent with stellar evolution calculations.

  13. Prevalence of and Factors Associated with Lens Opacities in a Korean Adult Population with and without Diabetes: The 2008–2009 Korea National Health and Nutrition Examination Survey

    Science.gov (United States)

    Kim, Tae Nyun; Lee, Joo Eun; Lee, Eun Ju; Won, Jong Chul; Noh, Jung Hyun; Ko, Kyung Soo; Rhee, Byoung Doo; Kim, Dong-Jun

    2014-01-01

    Objective We examined the prevalence of and factors associated with lens opacities in a Korean adult population with and without diabetes. Research Design and Methods Among the 11,163 adults (≥19 years old) from the fourth Korea National Health and Nutrition Examination Survey in 2008–2009, the data from laboratory tests, nutritional surveys, and slit-lamp examinations of 10,248 persons (4,397 men, 5,851 women) were examined. Cataract was defined as the presence of any nuclear, cortical, subcapsular, or mixed cataract in at least one eye, using the Lens Opacities Classification System III. Results The weighted prevalence of cataracts were 23.5% [95% confidence interval (CI), 21.7–25.4] in a Korean adult population (19–39 years old, 1.8% [1.3–2.5], 40–64 years old, 25.2% [22.5–28.1],≥65 years old, 87.8% [85.4–89.9])and 54.7% [50.1–59.2] in a diabetic population(19–39 years old, 11.6% [4.5–26.5], 40–64 years old, 41.1% [35.4–47.0], ≥65 years old, 88.3% [83.5–91.8]). In a logistic regression analysis, age, myopia, and the presence of diabetes were independent risk factors. For young (age 19–39 years) and middle aged (age 40–65 years) adults with diabetes, the OR of having a lens opacity is 5.04 [1.41–17.98] and 1.47 [1.11–1.94], respectively, as those without diabetes, whereas for adults aged 65 and older, there was no difference in the prevalence of cataract. Conclusions According to these national survey data, ∼ 24% of Korean adults and ∼ 55% of people with diabetes have cataracts. The presence of diabetes was independently associated with cataracts in young and middle aged adults. PMID:24718421

  14. A Determination of the Intergalactic Redshift Dependent UV-Optical-NIR Photon Density Using Deep Galaxy Survey Data and the Gamma-ray Opacity of the Universe

    Science.gov (United States)

    Stecker, Floyd W.; Malkan, Matthew A.; Scully, Sean T.

    2012-01-01

    We calculate the intensity and photon spectrum of the intergalactic background light (IBL) as a function of redshift using an approach based on observational data obtained in many different wavelength bands from local to deep galaxy surveys. This allows us to obtain an empirical determination of the IBL and to quantify its observationally based uncertainties. Using our results on the IBL, we then place 68% confidence upper and lower limits on the opacity of the universe to gamma-rays, free of the theoretical assumptions that were needed for past calculations. We compare our results with measurements of the extragalactic background light and upper limits obtained from observations made by the Fermi Gamma-ray Space Telescope.

  15. Theory of wave propagation in magnetized near-zero-epsilon metamaterials: evidence for one-way photonic states and magnetically switched transparency and opacity.

    Science.gov (United States)

    Davoyan, Arthur R; Engheta, Nader

    2013-12-20

    We study propagation of transverse-magnetic electromagnetic waves in the bulk and at the surface of a magnetized epsilon-near-zero (ENZ) medium in a Voigt configuration. We reveal that in a certain range of material parameters novel regimes of wave propagation emerge; we show that the transparency of the medium can be altered with the magnetization leading either to magnetically induced Hall opacity or Hall transparency of the ENZ. In our theoretical study, we demonstrate that surface waves at the interface between either a transparent or an opaque Hall medium and a homogeneous medium may, under certain conditions, be predominantly one way. Moreover, we predict that one-way photonic surface states may exist at the interface of an opaque Hall ENZ and a regular metal, giving rise to the possibility for backscattering immune wave propagation and isolation.

  16. Dynamical Opacity-Sampling Models of Mira Variables. II: Time-Dependent Atmospheric Structure and Observable Properties of 4 M-Type Model Series

    CERN Document Server

    Ireland, Michael J; Wood, Peter R

    2011-01-01

    We present 4 model series of the CODEX dynamical opacity-sampling models of Mira variables with solar abundances, designed to have parameters similar to $o$ Cet, R Leo and R Cas. We demonstrate that the CODEX models provide a clear physical basis for the molecular shell scenario used to explain interferometric observations of Mira variables. We show that these models generally provide a good match to photometry and interferometry at wavelengths between the near-infrared and the radio, and make the model outputs publicly available. These model also demonstrate that, in order to match visible and infrared observations, the Fe-poor silicate grains that form within 3 continuum radii must have small grain radii and therefore can not drive the winds from O-rich Mira variables.

  17. A four-channel portable solar radiometer for measuring particulate and/or aerosol opacity and concentration of NO2 and SO2 in stack plumes

    Science.gov (United States)

    Exton, R. J.; Gregory, R. W.

    1976-01-01

    Solar absorption radiometry has been investigated as a method of measuring stackplume effluents. A simple and inexpensive instrument was constructed for observing the sun at four wavelengths: 800, 600, 400, and 310 nm. Higher wavelength channels measured the effect of the particulates and NO2, and an ultraviolet channel measured the contribution of SO2 to the attenuation. Stack-plume measurements of opacity and concentration of NO2 and SO2 were in basic agreement with in-stack measurements. The major limitation on the use of the radiometer is the requirement for an accessible viewing position which allows the sun-plume-observer relationship to be attained. It was concluded that the solar radiometer offers an inexpensive method for monitoring plume effluents when the viewing position is not restricted.

  18. First-principles studies on the equation of state, thermal conductivity, and opacity of deuterium-tritium (DT) and polystyrene (CH) for inertial confinement fusion applications

    Science.gov (United States)

    Hu, S. X.; Collins, L. A.; Goncharov, V. N.; Kress, J. D.; Boehly, T. R.; Epstein, R.; McCrory, R. L.; Skupsky, S.

    2016-05-01

    Using first-principles (FP) methods, we have performed ab initio compute for the equation of state (EOS), thermal conductivity, and opacity of deuterium-tritium (DT) in a wide range of densities and temperatures for inertial confinement fusion (ICF) applications. These systematic investigations have recently been expanded to accurately compute the plasma properties of CH ablators under extreme conditions. In particular, the first-principles EOS and thermal-conductivity tables of CH are self-consistently built from such FP calculations, which are benchmarked by experimental measurements. When compared with the traditional models used for these plasma properties in hydrocodes, significant differences have been identified in the warm dense plasma regime. When these FP-calculated properties of DT and CH were used in our hydrodynamic simulations of ICF implosions, we found that the target performance in terms of neutron yield and energy gain can vary by a factor of 2 to 3, relative to traditional model simulations.

  19. 再探图书馆OPAC功能完善举措%Further Discussion on Improvement Measures of the Library OPAC Function

    Institute of Scientific and Technical Information of China (English)

    朱茗

    2012-01-01

    OPAC(Online Public Access Catalogue)is an main way of retrieving and using collection resources for readers in university libraries.Perfect system functions could provide more convenient services for readers.Nanjing Normal University Library has developed and improved the OPAC,such as developing the online self-help service coordinated loan and return of muti-schooldistrict books,the function of virtual bookshelves,pushing self-help short messaging service for collection bibliography information,embedding eduChina into the collection bibliography cataloging,adding the quotation format in bibliography records,and so on,in order to build the library service system with more characteristics based on OPAC.%OPAC是高校图书馆读者检索利用馆藏资源的主要途径之一,完善的系统功能可以为读者提供更加便捷的服务。南京师范大学图书馆对其OPAC系统进行了开发和改善,如开发了跨校区图书"通借通还"网上自助服务功能、"虚拟书架"功能、馆藏书目信息"自助手机短信"推送服务功能以及在主页和馆藏目录检索中嵌入e读平台、在书目记录中增加"引文格式"功能等,以建设更具特色的基于OPAC的图书馆服务体系。

  20. Testing Model Atmospheres for Young Very-low-mass Stars and Brown Dwarfs in the Infrared: Evidence for Significantly Underestimated Dust Opacities

    Science.gov (United States)

    Tottle, Jonathan; Mohanty, Subhanjoy

    2015-05-01

    We test state-of-the-art model atmospheres for young very-low-mass stars and brown dwarfs in the infrared, by comparing the predicted synthetic photometry over 1.2-24 μm to the observed photometry of M-type spectral templates in star-forming regions. We find that (1) in both early and late young M types, the model atmospheres imply effective temperatures ({{T}eff}) several hundred Kelvin lower than predicted by the standard pre-main sequence (PMS) spectral type-{{T}eff} conversion scale (based on theoretical evolutionary models). It is only in the mid-M types that the two temperature estimates agree. (2) The {{T}eff} discrepancy in the early M types (corresponding to stellar masses ≳ 0.4 {{M}⊙ } at ages of a few Myr) probably arises from remaining uncertainties in the treatment of atmospheric convection within the atmospheric models, whereas in the late M types it is likely due to an underestimation of dust opacity. (3) The empirical and model-atmosphere J-band bolometric corrections are both roughly flat, and similar to each other, over the M-type {{T}eff} range. Thus the model atmospheres yield reasonably accurate bolometric luminosities ({{L}bol}), but lead to underestimations of mass and age relative to evolutionary expectations (especially in the late M types) due to lower {{T}eff}. We demonstrate this for a large sample of young Cha I and Taurus sources. (4) The trends in the atmospheric model J-Ks colors, and their deviations from the data, are similar at PMS and main sequence ages, suggesting that the model dust opacity errors we postulate here for young ages also apply at field ages.

  1. Multilevel Analysis of Trachomatous Trichiasis and Corneal Opacity in Nigeria: The Role of Environmental and Climatic Risk Factors on the Distribution of Disease.

    Directory of Open Access Journals (Sweden)

    Jennifer L Smith

    Full Text Available The distribution of trachoma in Nigeria is spatially heterogeneous, with large-scale trends observed across the country and more local variation within areas. Relative contributions of individual and cluster-level risk factors to the geographic distribution of disease remain largely unknown. The primary aim of this analysis is to assess the relationship between climatic factors and trachomatous trichiasis (TT and/or corneal opacity (CO due to trachoma in Nigeria, while accounting for the effects of individual risk factors and spatial correlation. In addition, we explore the relative importance of variation in the risk of trichiasis and/or corneal opacity (TT/CO at different levels. Data from the 2007 National Blindness and Visual Impairment Survey were used for this analysis, which included a nationally representative sample of adults aged 40 years and above. Complete data were available from 304 clusters selected using a multi-stage stratified cluster-random sampling strategy. All participants (13,543 individuals were interviewed and examined by an ophthalmologist for the presence or absence of TT and CO. In addition to field-collected data, remotely sensed climatic data were extracted for each cluster and used to fit Bayesian hierarchical logistic models to disease outcome. The risk of TT/CO was associated with factors at both the individual and cluster levels, with approximately 14% of the total variation attributed to the cluster level. Beyond established individual risk factors (age, gender and occupation, there was strong evidence that environmental/climatic factors at the cluster-level (lower precipitation, higher land surface temperature, higher mean annual temperature and rural classification were also associated with a greater risk of TT/CO. This study establishes the importance of large-scale risk factors in the geographical distribution of TT/CO in Nigeria, supporting anecdotal evidence that environmental conditions are associated

  2. Poster 13: Large-scale simultaneous mapping of Titan's aerosol opacity and surface albedo by a new massive inversion method of Cassini/VIMS data

    Science.gov (United States)

    Maltagliati, Luca; Rodriguez, Sebastien; Sotin, Christophe; Rannou, Pascal; Bezard, Bruno; Solomonidou, Anezina; Coustenis, Athena; Appere, Thomas; Cornet, Thomas; Le Mouelic, Stephane%F. Aa(Aim Cea Saclay; Lesia Observatoire de Paris), Ab(Aim Cea Saclay; Universite Paris 7), Ac(Jpl; Lpg Nantes), Ad(Gsma Reims), Ae(Lesia Observatoire De Paris), Af(Jpl), Ag(Lesia Observatoire De Paris), Ah(Aim Cea Saclay), Ai(Esac/Esa), Aj(Lpg Nantes)

    2016-06-01

    We have still limited information on Titan's surface albedo in the near-infrared. Only few spectral windows exist in between the intense methane bands, and even those windows are strongly affected by atmospheric contributions (absorption, scattering). Yet, this part of the spectrum is important to determine the surface composition thanks to the wealth of absorption bands by minerals and ices present there. A radiative transfer model is an effective tool to take the atmospheric effects into consideration in the analysis (e.g. Rannou et al. 2010, Griffith et al 2012, Solomonidou et al. 2016,...), but it is too time-consuming to process the whole VIMS hyperspectral dataset (millions of spectra) and create large-scale maps of the surface albedo. To overcome this problem, we developed an inversion method of VIMS data that employs lookup tables of synthetic spectra produced by a state-of-the-art radiative transfer model (described in its original form in Hirtzig et al. 2013). The heavy computational part (calling the radiative transfer model) is thus done only once for all during the creation of the modeled spectra. We updated the model with new methane spectroscopy and the new aerosol parameters we found in our analysis of the VIMS Emission Phase Function (see the other Maltagliati et al. abstract in this workshop). We analyzed in detail the behavior of the spectra as a function of the free parameters of the model (three inputs, the incidence, emergence and azimuth angles; and two products: the aerosol opacity and the surface albedo) in order to create an optimized grid for the lookup table. The lookup tables were then grafted onto an ad-hoc inversion model. Our method can process a whole 64x64 VIMS datacube in few minutes, with a gain in computational time of a factor of more than one thousand with respect to the standard method. This will consent for the first time a truly massive inversion of VIMS data and large-scale acquisition of Titan's surface albedo, paving the

  3. Non-LTE Models and Theoretical Spectra of Accretion Disks in Active Galactic Nuclei. IV. Effects of Compton Scattering and Metal Opacities

    CERN Document Server

    Hubeny, I; Krolik, J H; Agol, E; Hubeny, Ivan; Blaes, Omer; Krolik, Julian H.

    2001-01-01

    We extend our models of the vertical structure and emergent radiation field of accretion disks around supermassive black holes described in previous papers of this series. Our models now include both a self-consistent treatment of Compton scattering and the effects of continuum opacities of the most important metal species (C, N, O, Ne, Mg, Si, S, Ar, Ca, Fe, Ni). With these new effects incorporated, we compute the predicted spectrum from black holes accreting at nearly the Eddington luminosity (L/L_Edd = 0.3) and central masses of 10^6, 10^7, and 10^8 M_sun. We also consider two values of the Shakura-Sunyaev alpha parameter, 0.1 and 0.01. Although it has little effect when M > 10^8 M_sun, Comptonization grows in importance as the central mass decreases and the central temperature rises. It generally produces an increase in temperature with height in the uppermost layers of hot atmospheres. Compared to models with coherent electron scattering, Comptonized models have enhanced EUV/soft X-ray emission, but they...

  4. An Empirical Determination of the Intergalactic Background Light from UV to FIR Wavelengths Using FIR Deep Galaxy Surveys and the Gamma-ray Opacity of the Universe

    CERN Document Server

    Stecker, Floyd W; Malkan, Matthew A

    2016-01-01

    We have previously calculated the intergalactic background light (IBL) as a function of redshift in the far ultraviolet to near infrared range, based purely on data from deep galaxy surveys. Here we utilize similar methods to determine the mid- and far infrared IBL out to a wavelength of 850 microns. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. By also including the effect of the 2.7 K cosmic background photons, we determine 68% confidence upper and lower limits on the opacity of the universe to gamma-rays up to PeV energies. Our direct results on the IBL are consistent with those from complimentary gamma-ray analyses using observations from the Fermi $\\gamma$-ray space telescope and the H.E.S.S. air Cherenkov telescope. Thus, we find no evidence of previously suggested processes for the modification of gamma-ray spectra other than that of absorption by pair production alone.

  5. CT characteristics and pathological implications of early stage (T1N0M0) lung adenocarcinoma with pure ground-glass opacity

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Xin; Zhao, Shao-hong; Wu, Jian; Wu, Chong-chong; Chang, Rui-ping; Ju, Hai-yue [Chinese PLA General Hospital, Department of Radiology, Beijing (China); Gao, Jie; Wang, Dian-jun [Chinese PLA General Hospital, Department of Pathology, Beijing (China)

    2015-09-15

    To analyze the CT characteristics and pathological classification of early lung adenocarcinoma (T1N0M0) with pure ground-glass opacity (pGGO). Ninety-four lesions with pGGO on CT in 88 patients with T1N0M0 lung adenocarcinoma were selected from January 2010 to December 2012. All lesions were confirmed by pathology. CT appearances were analyzed including lesion location, size, density, uniformity, shape, margin, tumour-lung interface, internal and surrounding malignant signs. Lesion size and density were compared using analysis of variance, lesion size also assessed using ROC curves. Gender of patients, lesion location and CT appearances were compared using χ2-test. There were no significant differences in gender, lesion location and density with histological invasiveness (P > 0.05). The ROC curve showed that the possibility of invasive lesion was 88.73 % when diameter of lesion was more than 10.5 mm. There was a significant difference between lesion uniformity and histological invasiveness (P = 0.01). There were significant differences in margin, tumour-lung interface, air bronchogram with histological invasiveness (P = 0.02,P = 0.00,P = 0.048). The correlation index of lesion size and uniformity was r = 0.45 (P = 0.00). The lesion size and uniformity, tumour-lung interface and the air bronchogram can help predict invasive extent of early stage lung adenocarcinoma with pGGO. (orig.)

  6. Gas and dust in the star-forming region rho Oph A: The dust opacity exponent beta and the gas-to-dust mass ratio g2d

    CERN Document Server

    Liseau, R; Lunttila, T; Olberg, M; Rydbeck, G; Bergman, P; Justtanont, K; Olofsson, G; de Vries, B L

    2015-01-01

    We aim at determining the spatial distribution of the gas and dust in star-forming regions and address their relative abundances in quantitative terms. We also examine the dust opacity exponent beta for spatial and/or temporal variations. Using mapping observations of the very dense rho Oph A core, we examined standard 1D and non-standard 3D methods to analyse data of far-infrared and submillimeter (submm) continuum radiation. The resulting dust surface density distribution can be compared to that of the gas. The latter was derived from the analysis of accompanying molecular line emission, observed with Herschel from space and with APEX from the ground. As a gas tracer we used N2H+, which is believed to be much less sensitive to freeze-out than CO and its isotopologues. Radiative transfer modelling of the N2H+(J=3-2) and (J=6-5) lines with their hyperfine structure explicitly taken into account provides solutions for the spatial distribution of the column density N(H2), hence the surface density distribution ...

  7. Apolipoprotein E mediates enhanced plasma high-density lipoprotein cholesterol clearance by low-dose streptococcal serum opacity factor via hepatic low-density lipoprotein receptors in vivo.

    Science.gov (United States)

    Rosales, Corina; Tang, Daming; Gillard, Baiba K; Courtney, Harry S; Pownall, Henry J

    2011-08-01

    Recombinant streptococcal serum opacity factor (rSOF) mediates the in vitro disassembly of human plasma high-density lipoprotein (HDL) into lipid-free apolipoprotein (apo) A-I, a neo-HDL that is cholesterol poor, and a cholesteryl ester-rich microemulsion (CERM) containing apoE. Given the occurrence of apoE on the CERM, we tested the hypothesis that rSOF injection into mice would reduce total plasma cholesterol clearance via apoE-dependent hepatic low-density lipoprotein receptors (LDLR). rSOF (4 μg) injection into wild-type C57BL/6J mice formed neo-HDL, CERM, and lipid-free apoA-I, as observed in vitro, and reduced plasma total cholesterol (-43%, t(1/2)=44±18 minutes) whereas control saline injections had a negligible effect. Similar experiments with apoE(-/-) and LDLR(-/-) mice reduced plasma total cholesterol ≈0% and 20%, respectively. rSOF was potent; injection of 0.18 μg of rSOF produced 50% of maximum reduction of plasma cholesterol 3 hours postinjection, corresponding to a ≈0.5-mg human dose. Most cholesterol was cleared hepatically (>99%), with rSOF treatment increasing clearance by 65%. rSOF injection into mice formed a CERM that was cleared via hepatic LDLR that recognize apoE. This reaction could provide an alternative mechanism for reverse cholesterol transport.

  8. Comparison of chest radiography, chest digital tomosynthesis and low dose MDCT to detect small ground-glass opacity nodules: an anthropomorphic chest phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Doo, Kyung Won; Kang, Eun-Young; Yong, Hwan Seok [Korea University Guro Hospital, Korea University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Ham, Soo-Youn [Korea University Anam Hospital, Korea University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Lee, Ki Yeol; Choo, Ji Yung [Korea University Ansan Hospital, Korea University College of Medicine, Department of Radiology, Ansan (Korea, Republic of)

    2014-12-15

    The purpose of this study was to evaluate the diagnostic performance of chest radiography (CXR), chest digital tomosynthesis (DT) and low dose multidetector computed tomography (LDCT) for the detection of small pulmonary ground-glass opacity (GGO) nodules, using an anthropomorphic chest phantom. Artificial pulmonary nodules were placed in a phantom and a total of 40 samples of different nodule settings underwent CXR, DT and LDCT. The images were randomly read by three experienced chest radiologists. Free-response receiver-operating characteristics (FROC) were used. The figures of merit for the FROC curves averaged for the three observers were 0.41, 0.37 and 0.76 for CXR, DT and LDCT, respectively. FROC analyses revealed significantly better performance of LDCT over CXR or DT for the detection of GGO nodules (P < 0.05). The difference in detectability between CXR and DT was not statistically significant (P = 0.73). The diagnostic performance of DT for the detection of pulmonary small GGO nodules was not significantly different from that of CXR, but LDCT performed significantly better than both CXR and DT. DT is not a suitable alternative to CT for small GGO nodule detection, and LDCT remains the method of choice for this purpose. (orig.)

  9. Smoke opacity of agricultural tractor using biodiesel in function of weather conditions in the time of testing; Opacidade da fumaca de trator agricola utilizando biodiesel em funcao das condicoes climaticas no horario de execucao do ensaio

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Afonso; Camara, Felipe T. da; Oliveira, Melina Cais Jejcic de; Furlani, Carlos E.A.; Silva, Rouverson Pereira da; Mello Junior, Jose G.S. [Universidade Estadual Paulista (FCAV/UNESP), SP (Brazil). Fac. de Ciencias Agrarias e Veterinarias. Dept. de Engenharia Rural], E-mail: afonso@fcav.unesp.br

    2009-07-01

    The biodiesel highlights as an alternative fuel to petroleum diesel, due its similar diesel properties, allowing the biodiesel replace the diesel without engine's alterations. The present work aimed measure the tractor's smoke opacity running with biodiesel in three proportions (B0, B50, and B100), in function of environment temperature and moisture in eight times (1h, 4h, 7h, 10h, 13h, 16h, 19h, and 22h). The experiment was conducted in the Rural Engineering Department of UNESP, Jaboticabal, Brazil, it was used a Valtra BM100 4x2 TDA (74kW - 100 cv) tractor, in the engine at 2350 rpm, and a soybean's distillated ethylic Biodiesel produced by USP - Laboratory of Development of Clean Technologies, in Ribeirao Preto, Brazil. The results evidence smoke opacity reduction in order to environment temperature reduction and when increased the moisture. (author)

  10. Correlating Bacharach opacity in fuel oil exhaust. Prediction of the operating parameters that reduce it; Correlation de l'opacite Bacharach des gaz d'echappement. Prediction des parametres operateurs qui la reduisent

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, M.; Coello, J.; Maspoch, S.; Puigdomenech, A. [Universitat Autonoma de Barcelona, Dept. de Quimica (Spain); Peralta, X.; Gonzalez, J.M.; Torres, J. [Asfaltos Espanoles SA, Refineria de Tarragona (Spain)

    2000-07-01

    A study was conducted with a view to determining the steps to be taken in order to control the Bacharach opacity of smoke released by different types of engines powered by fuel oil through the same chimney. A statistical model was constructed to relate Bacharach opacity to the operational parameters of the burning equipment on the basis of information recorded during its routine functioning over a period of about one year, with no laboratory experiments nor intentional alteration of such parameters. Different chemo-metric tools were applied to the data recorded over a period long enough to ensure a good model. Owing to the high complexity of the data handled (equipment parameters, fuel oil properties, operating conditions, etc.), the model was constructed by using different tools that were tested in order of increasing complexity. Thus, a Principal Component Analysis (PCA) was initially conducted on the variables defining the different types of fuel oil used in order to suppress their high correlation. The scores obtained from this analysis were used as the fuel data in the subsequent steps. Owing to the high complexity of the parameters involved, linear regression methods were not functional, so the non-linear regression method Alternating Conditional Expectations (ACE) had to be used instead to determine the influence of these parameters on Bacharach opacity. After the model was constructed, the parameters that govern opacity were determined and the model was experimentally validated by exploring the variables that can be modified at plant level (viz. the combination of conradson coke and asphaltenes in the fuel, the oil viscosity at burner and the proportion of oxygen in the furnace). Changes in these variables were found to alter the properties of the stack; also, the predictions of the ACE model were confirmed. Consequently, the proposed methodology allows the effective control of smoke released by the equipment. (authors)

  11. The Practice and Development of OPAC in Web2.0 Environment%Web2.0环境下OPAC服务的实践与发展

    Institute of Scientific and Technical Information of China (English)

    欧阳红红

    2012-01-01

    The paper discusses a series of challenges which OPAC service is facing from the limitation of the traditional OPAC service, the development of search engine and online bookstore, the boosting of Web2.0 technology and the FRBRized display, points out the development direction of the OPAC under the environment of Web2.0 through some new type of OPAC practice as the integration of the resources, strengthen the retrieval function, rich the retrieval results, the user participation, personalized service, online consultation, embedded user environment, enhancing the user experience and so on, to provide certain theoretical reference and practical basis for the ascension of our country's library information service level.%本文从传统OPAC服务本身的局限性、搜索引擎与网上书店的发展、Web2.0技术的助推及FRBR化显示等几个方面阐述了OPAC服务面临的一系列挑战,并通过资源整合、强化检索功能、丰富检索结果、用户参与、个性化服务、在线咨询、嵌入用户环境、加强用户体验等一些新型的OPAC实践,指出了OPAC服务在Web2.0环境下的发展方向,为我国图书馆信息服务水平的提升提供一定的理论参考和实践依据。

  12. Biodiesel of palm oil in tractor agricultural: opacity of smoke in the light of storage time; Biodiesel de dende em trator agricola: opacidade da fumaca em funcao do tempo de armazenamento

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Leomar P. [Instituto Federal do Triangulo Mineiro (IFTM), Uberlandia, MG (Brazil)], email: leomaragro@yahoo.com.br; Lopes, Afonso; Oliveira, Melina C.J. [Universidade Estadual Paulista Julio de Mesquita Filho (FCAV/UNESP), Jaboticabal, SP (Brazil). Fac. de Ciencias Agrarias e Veterinarias. Dept. de Engenharia Rural; Camara, Felipe T. [Universidade Federal do Ceara (UFC), Cariri, CE (Brazil)

    2011-07-01

    The scenario of atmospheric emissions world characterized-if, in recent years, due to a series of technical factors, economic and political, by the need to reduce the consumption of petroleum. The objective of this work was to evaluate the opacity of smoke of a motor of a tractor agricultural operating with biodiesel of palm oil with different periods of storage. The experiment was conducted in the Laboratory of machinery and agricultural mechanization of Rural Engineering Department of UNESP, Jaboticabal, SP. In this study,-if a tractor Valtra BM 110 4x2 TDA 73,6 kW (100 cv) in engine 2.350 rpm. The experimental design was completely randomized, in factorial scheme 5x3, with 3 repetitions. The combinations of factors were five proportions of mixing biodiesel for diesel (B0, B5, B25, B 50 and B100, that the number indicates the percentage of biodiesel for diesel) and three storage times in condition environment (0, 3 and 6 months). The results showed that in relation to B0, when used biodiesel in the proportion of B100, the opacity of smoke reduced in 50.4% and the time of storage of biodiesel not committed the opacity of smoke from combustion of the engine. (author)

  13. Ground-glass opacity in diffuse lung diseases: high-resolution computed tomography-pathology correlation; Opacidades em vidro fosco nas doencas pulmonares difusas: correlacao da tomografia computadorizada de alta resolucao com a anatomopatologia

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Maria Lucia de Oliveira; Vianna, Alberto Domingues; Marchiori, Edson [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Radiologia; Souza Junior, Arthur Soares [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Disciplina de Radiologia; Moraes, Heleno Pinto de [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Patologia]. E-mail: edmarchiori@zipmail.com.br

    2003-12-01

    Ground-glass opacity is a finding frequently seen in high-resolution computed tomography examinations of the chest and is characterized by hazy increased attenuation of lung, however without blurring of bronchial and vascular margins. Due to its un specificity, association with other radiological, clinical and pathological findings must be considered for an accurate diagnostic interpretation. In this paper were reviewed 62 computed tomography examinations of patients with diffuse pulmonary diseases of 14 different etiologies in which ground-glass opacity was the only or the most remarkable finding, and correlated this findings with pathology abnormalities seen on specimens obtained from biopsies or necropsies. In pneumocystosis, ground-glass opacities correlated histologically with alveolar occupation by a foaming material containing parasites, in bronchiole alveolar cell carcinoma with thickening of the alveolar septa and occupation of the lumen by mucus and tumoral cells, in paracoccidioidomycosis with thickening of the alveolar septa, areas of fibrosis and alveolar bronchopneumonia exudate, in sarcoidosis with fibrosis or clustering of granulomas and in idiopathic pulmonary fibrosis with alveolar septa thickening due to fibrosis. Alveolar occupation by blood was found in cases of leptospirosis, idiopathic hemo siderosis, metastatic kidney tumor and invasive aspergillosis whereas oily vacuole were seen in lipoid pneumonia, proteinaceous and lipo proteinaceous material in silico proteinosis and pulmonary alveolar proteinosis, and edematous fluid in cardiac failure. (author)

  14. Synthesis, X-ray Opacity, and Biological Compatibility of Ultra-High Payload Elemental Bismuth Nanoparticle X-ray Contrast Agents.

    Science.gov (United States)

    Brown, Anna L; Naha, Pratap C; Benavides-Montes, Victor; Litt, Harold I; Goforth, Andrea M; Cormode, David P

    2014-04-01

    Inorganic nanoscale X-ray contrast agents (XCAs) offer many potential advantages over currently used intravascular molecular contrast agents, including longer circulation and retention times, lower administration volumes, and greater potential for site directed imaging. Elemental bismuth nanoparticles (BiNPs) are particularly attractive candidate XCAs due to the low cost, the high atomic number and high density of bismuth, and the likelihood that BiNPs will oxidatively decompose to biocompatible bismuth(III) ions at controlled rates for renal excretion. Herein we describe the synthesis of ultrahigh payload BiNPs in 1,2-propanediol using a borane reducing agent and glucose as a biocompatible surface stabilizer. Both synthetic solvent (1,2-propanediol) and surfactant (glucose) are evident on the BiNP surfaces when analyzed by (1)H NMR and FT-IR spectroscopies. These particles contain ∼6 million Bi atoms per NP and have large inorganic cores (74 nm by TEM) compared to their hydrodynamic size (86 nm by DLS). Thus, the dense BiNP core constitutes the majority (∼60%) of each particle's volume, a necessary property to realize the full potential of nanoscale XCAs. Using quantitative computed tomography in phantom and in vitro imaging studies, we demonstrate that these BiNPs have greater X-ray opacity than clinical small molecule iodinated contrast agents at the same concentrations. We furthermore demonstrate a favorable biocompatibility profile for these BiNPs in vitro. Altogether, these studies indicate that these ultrahigh payload BiNPs, synthesized from known biocompatible components, have promising physical and cytotoxicological properties for use as XCAs.

  15. Implementation of Library OPAC System Based on SSH Frame%基于SSH框架技术的图书馆OPAC系统的实现

    Institute of Scientific and Technical Information of China (English)

    陈连和

    2014-01-01

    The process of using the SSH combination frame in Java EE technology to achieve OPAC system is described in detailed. In the general structure of the program, Struts supports the skeleton of program, and Hibernate simplifies database operation, and Spring integrates with Struts and Hibernate, manages dependencies and transaction, simplifies Hibernate code. In the code, using the SSH combination frame, orderly programming is done goodly with the MVC technology and three layers structure and to an interface and according to development order of "view→controller →business logic model →data access model". Therefore, SSH combination framework provides a unified program structure which is enable to code orderly and efficiently and facilitate the expansion and maintenance.%详细地阐述了使用Java EE技术中SSH组合框架实现OPAC系统的过程。程序的总体结构上,以Struts撑起程序的骨架,Hibernate简化数据库操作,Spring与Struts、Hibernate集成,管理依赖关系和管理事务,简化Hibernate编码;编码上,SSH组合框架使得很好地使用MVC技术和基于三层结构、面向接口的编程方式,以“视图→控制器→业务逻辑模型→数据访问模型”的开发顺序有序地进行编程。因此,SSH组合框架提供统一的程序结构,使得有序、高效地编码,也便于扩展和维护。

  16. Diagnostic performance of percutaneous lung biopsy using automated biopsy needles under CT-fluoroscopic guidance for ground-glass opacity lesions

    Science.gov (United States)

    Yoshimatsu, R; Miura, H; Yamada, K; Takahata, A; Matsumoto, T; Hasebe, T

    2013-01-01

    Objective: The goal of our study was to evaluate the diagnostic performance of percutaneous lung biopsy under CT-fluoroscopic guidance for ground-glass opacity (GGO) lesions. Methods: 85 percutaneous needle lung biopsies were performed in 73 patients. Specimens were obtained by core biopsy utilising an automated cutting needle and were evaluated histologically. Final diagnosis was confirmed by independent surgical pathology, independent culture results or clinical follow-up. Results: Rates of adequate specimens obtained and of precise diagnosis by needle biopsy were 92.9% (79/85) and 90.6% (77/85) of evaluated lung lesions, respectively. Precise diagnosis was achieved in 87.1% (27/31) of lesions ≤10 mm in diameter, 90.0% (36/40) of lesions >10 mm to ≤20 mm and 100.0% (14/14) of lesions >20 mm. Precision in diagnosing GGO lesions according to the GGO component was 73.9% (17/23) for pure GGO lesions and 96.8% (60/62) for part-solid GGO lesions. Obtaining a precise diagnosis did not differ significantly according to the lesion size (p=0.3840), but differences were significant according to the GGO component (p=0.0047). Malignancy was accurately diagnosed in 35 of 36 malignant lesions for which surgery was later performed. The specific cell type determined from specimens obtained by needle biopsy was exactly the same as the final histological diagnosis obtained after surgery in 20 lesions. Conclusion: Tissue-core lung biopsy under CT-fluoroscopic guidance for a GGO lesion provides a high degree of diagnostic accuracy but is less reliable for determining the specific cell type. Advances in knowledge: Percutaneous lung biopsy under CT-fluoroscopic guidance for GGO is useful in differentiating malignancy. PMID:23385998

  17. Comparison of in vitro eye irritation potential by bovine corneal opacity and permeability (BCOP) assay to erythema scores in human eye sting test of surfactant-based formulations.

    Science.gov (United States)

    Cater, Kathleen C; Harbell, John W

    2008-01-01

    The bovine corneal opacity and permeability (BCOP) assay can be used to predict relative eye irritation potential of surfactant-based personal care formulations relative to a corporate benchmark. The human eye sting test is typically used to evaluate product claims of no tears/no stinging for children's bath products. A preliminary investigation was conducted to test a hypothesis that the BCOP assay could be used as a prediction model for relative ranking of human eye irritation responses under conditions of a standard human eye sting test to surfactant-based formulations. BCOP assays and human eye sting tests were conducted on 4 commercial and 1 prototype body wash (BW) developed specifically for children or as mild bath products. In the human eye sting test, 10 mul of a 10% dosing solution is instilled into one eye of each panelist (n = 20), and the contralateral eye is dosed with sterile water as a control. Bulbar conjunctival erythema responses of each eye are graded at 30 seconds by an ophthalmologist. The BCOP assay permeability values (optical density at 490 nm [OD(490)]) for the 5 BWs ranged from 0.438 to 1.252 (i.e., least to most irritating). By comparison, the number of panelists exhibiting erythema responses (mild to moderately pink) ranged from 3 of 20 panelists for the least irritating BW to 10 of 20 panelists for the most irritating BW tested. The relative ranking of eye irritation potential of the 5 BWs in the BCOP assay compares favorably with the relative ranking of the BWs in the human eye sting test. Based on these findings, the permeability endpoint of the BCOP assay, as described for surfactant-based formulations, showed promise as a prediction model for relative ranking of conjunctival erythema responses in the human eye. Consequently, screening of prototype formulations in the BCOP assay would allow for formula optimization of mild bath products prior to investment in a human eye sting test.

  18. Translucent Procedures, Abstraction without Opacity

    Science.gov (United States)

    1993-10-01

    que dI no pudo recibir. con este trabajo realizo. Lo proinetido es deuda. Acknowledgments There are many people to whom I owe my sanity and to whom I...21 2.1.1 Fundamental Differences .......................... 23 2.1.2 Accidental Differences ....... ...................... 26 2.2 The...no a-priori reason why the whole code could not. be written in TScheme. TScheme differs from Scheme in both fundamental and accidental ways. 2.1

  19. Neo High-Density Lipoprotein Produced by the Streptococcal Serum Opacity Factor Activity against Human High-Density Lipoproteins Is Hepatically Removed via Dual Mechanisms.

    Science.gov (United States)

    Rodriguez, Perla J; Gillard, Baiba K; Barosh, Rachel; Gotto, Antonio M; Rosales, Corina; Pownall, Henry J

    2016-10-18

    Injection of streptococcal serum opacity factor (SOF) into mice reduces the plasma cholesterol level by ∼40%. In vitro, SOF converts high-density lipoproteins (HDLs) into multiple products, including a small HDL, neo HDL. In vitro, neo HDL accounts for ∼60% of the protein mass of the SOF reaction products; in vivo, the accumulated mass of neo HDL is <1% of that observed in vitro. To identify the underlying cause of this difference, we determined the fate of neo HDL in plasma in vitro and in vivo. Following incubation with HDL, neo HDL-PC rapidly transfers to HDL, giving a small remnant, which fuses with HDL. An increased level of SR-B1 expression in Huh7 hepatoma cells and a reduced level of LDLR expression in CHO cells had little effect on neo HDL-[(3)H]CE uptake. Thus, the dominant receptors for neo HDL uptake are not LDLR or SR-B1. The in vivo metabolic fates of neo HDL-[(3)H]CE and HDL-[(3)H]CE were different. Thirty minutes after the injection of neo HDL-[(3)H]CE and HDL-[(3)H]CE into mice, plasma [(3)H]CE counts were 40 and 53%, respectively, of injected counts, with 10 times more [(3)H]CE appearing in the livers of neo HDL-[(3)H]CE-injected than in those of HDL-[(3)H]CE-injected mice. These data support a model of neo HDL-[(3)H]CE clearance by two parallel pathways. At early post-neo HDL-[(3)H]CE injection times, some neo HDL is directly removed by the liver; the remainder transfers its PC to HDL, leaving a remnant that fuses with HDL, which is also hepatically removed more slowly. Given that SR-B1 and SOF both remove CE from HDL, this novel mechanism may also underlie the metabolism of remnants released by hepatocytes following selective SR-B1-mediated uptake of HDL-CE.

  20. Clinical Study of Intra-operative Computed Tomography Guided Localization with A Hook-wire System for Small Ground Glass Opacities in Minimally Invasive Resection

    Directory of Open Access Journals (Sweden)

    Xiangyang CHU

    2014-12-01

    Full Text Available Background and objective Localization of pulmonary ground glass small nodule is the technical difficulty of minimally invasive operation resection. The aim of this study is to evaluate the value of intraoperative computed tomography (CT-guided localization using a hook-wire system for small ground glass opacity (GGO in minimally invasive resection, as well as to discuss the necessity and feasibility of surgical resection of small GGOs (<10 mm through a minimally invasive approach. Methods The records of 32 patients with 41 small GGOs who underwent intraoperative CT-guided double-thorn hook wire localization prior to video-assisted thoracoscopic wedge resection from October 2009 to October 2013 were retrospectively reviewed. All patients received video-assisted thoracoscopic surgery (VATS within 10 min after wire localization. The efficacy of intraoperative localization was evaluated in terms of procedure time, VATS success rate, and associated complications of localization. Results A total of 32 patients (15 males and 17 females underwent 41 VATS resections, with 2 simultaneous nodule resections performed in 3 patients, 3 lesion resections in 1 patient, and 5 lesions in a patient. Nodule diameters ranged from 2 mm-10 mm (mean: 5 mm. The distance of lung lesions from the nearest pleural surfaces ranged within 5 mm-24 mm (mean: 12.5 mm. All resections of lesions guided by the inserted hook wires were successfully performed by VATS (100% success rate. The mean procedure time for the CT-guided hook wire localization was 8.4 min (range: 4 min-18 min. The mean procedure time for VATS was 32 min (range: 14 min-98 min. The median hospital time was 8 d (range: 5 d-14 d. Results of pathological examination revealed 28 primary lung cancers, 9 atypical adenomatous hyperplasia, and 4 nonspecific chronic inflammations. No major complication related to the intraoperative hook wire localization and VATS was noted. Conclusion Intraoperative CT-guided hook wire

  1. SURGICAL OUTCOME OF TRIPLE PROCEDURE AS PENETRATING KERATOPLASTY WITH EXTRACAPSULAR CATARACT EXTRACTION WITH POSTERIOR CHAMBER INTRAOCULAR LENS IMPLANTATION IN PATIENTS WITH BOTH CENTRAL CORNEAL OPACITY AND ADVANCED CATARACT AT RURAL SET UP

    Directory of Open Access Journals (Sweden)

    Shubhangi Nigwekar, Kishor Badhe, Neeta Misra, Surekha Bangal

    2015-10-01

    Full Text Available Purpose: To study the surgical outcome of triple procedure as penetrating keratoplasty (PKP with conventional extra capsular cataract extraction (ECCE with posterior chamber intraocular lens (PCIOL implantation in patients with both central corneal opacity and advanced cataract at rural set up. Introduction: When corneal opacity and cataract present together then well-established and effective triple procedure is indicated. Prognosis for a clear graft is good in triple, as graft endothelium does not touch the hard nucleus which may occur in two steps or sequential surgery. It provides faster visual rehabilitation. Being single step procedure it reduces patient’s hospital stay, postoperative care and follows up visits. Methodology: In this hospital based observational , three years longitudinal study, we studied the surgical outcome of relatively rare one step triple procedure as PKP with conventional ECCE with PCIOL implantation in sulcus or in bag, in patients with both central corneal opacity and advanced cataract at rural set up. The outcome measures included graft clarity on slit lamp, postoperative unaided visual acuity with Snellen’s chart and the occurrence of postoperative complications after taking IEC permission and informed written consent in local language from study patients. Results: Out of 13 study patients mean age was 61.15yrs (Range50-80yrs. Follow up range was 9-34 months. At final follow up 9 patients (69.23% had clear grafts and 61.52% patients gained visual acuity >6/24. Graft failure was the most common post operative complication in 30.76% followed by Posterior capsular opacification (PCO in 15.38% patients which was treated well with YAG laser capsulotomy. Conclusion: Triple procedure gives good results in respect to graft clarity, unaided vision, and faster rehabilitation.

  2. Documentación Informativa. Práctica 1: Elaboración de una bibliografía y localización en catálogos bibliográficos (OPACs)

    OpenAIRE

    Alemany Martínez, Dolores

    2010-01-01

    Elaboración de una bibliografía y localización en catálogos bibliográficos (OPACs). Elaborar una bibliografía siguiendo las pautas europeas o norteamericanas. Localización de dicha bibliografía en catálogos bibliográficos UNICORN – ARIADNA – REBIUN – REBECA – GABRIEL... Entender la importancia del ISBN en los libros. Utilizar algún tipo de SERVICIO DE REFERENCIA en línea.

  3. Surgical prevention of posterior capsule opacity in congenital cataract%先天性白内障手术预防术后后囊浑浊的研究

    Institute of Scientific and Technical Information of China (English)

    雷智

    2013-01-01

    目的 探讨在先天性白内障手术中预防术后后囊浑浊的方法.方法 44例(46眼)先天性白内障手术,前后囊双撕囊联合人工晶状体光学区后囊口嵌顿术作为观察组;同期进行的36例(38眼)先天性白内障手术前后囊双撕囊植入人工晶状体作为对照组.两组术后随访视力及晶状体后囊中央部浑浊程度进行统计学分析.结果 术后矫正视力两组比较,观察组视力优于对照组(x2=5.006,x2 =6.717,P<0.05).在两组后囊中央部浑浊同级别比较中,观察组:对照组,0级者35:9,1级者5:12;2级者3:8;3级和4级者3:9.观察组无浑浊例数较对照组明显增多,各级别后囊浑浊例数观察组均低于对照组(,=22.91,P <0.05).结论 先天性白内障手术中,行前后囊双环形撕囊联合人工晶状体光学区后囊口嵌顿术,能减少视轴区后囊浑浊的发生,有助于视功能的恢复.%Objective To explore the surgical preventive methods of posterior capsule opacity in congenital cataract.Methods 80 cases (84 eyes) of congenital cataract were enrolled in the study who underwent cataract extraction and intraocular lens implantation.All cases were divided into two groups:the experimental group(46 eyes of 44 cases) and the control group (38 eyes of 36 cases).The experimental group underwent anterior capsulorhexis,posterior capsulorhexis and the intraocular lens optical unit was embedded in the margin of the posterior capsular opening.Only anterior capsulorhexis and posterior capsulorhexis were performed in the control group.The visual acuities and degrees of posterior capsule opacity were compared between two groups.Results The patients' corrected visual acuities in the experimental group were better than that in the control group after surgery.The differences were statistically significant (x2 =5.006,P < 0.05).The results of degrees of posterior capsule opacity were 35 cases in experimental group and 9 cases in control group at level 0,5 cases

  4. Attention Crisis and Reconstruction Strategies of Online Public Access Catalogue (OPAC)in Information Age:Based on the Perspective of Supply-demand Asymmetry%图书馆联机目录(OPAC)的注意力危机及其重构策略——基于供需不对称视角的分析

    Institute of Scientific and Technical Information of China (English)

    于国辉; 严潮斌; 吴旭; 杨广锋

    2013-01-01

    在注意力经济时代,图书馆联机目录(OPAC)面临严重的注意力危机,并通过多米诺骨牌效应引发图书馆的整体性危机.以供需不对称视角作为新的研究范式,引入个体自发、环境激发和信息需求三个变量,有助于对OPAC危机做出针对性的解释用户在数字时代产生了大数据检索、反馈共建、即时性咨询和社会化互动4类新的需求,但根据对北京市26所重点高校图书馆OPAC的考察后,发现绝大多数OPAC系统未能提供与用户需求相对称的信息供给服务,体现为馆内线性文本、版权方标注、线下延时咨询和个体化服务4个方面的局限性,由此构成OPAC危机的第一根源.据此,提出OPAC重构的4个策略,以有效应对当前的注意力危机.

  5. Clinical application of ultrasound biomicroscopy in the treatment of congenital corneal opacities%超声生物显微镜在先天性角膜混浊诊疗中的应用价值

    Institute of Scientific and Technical Information of China (English)

    李东芳; 赵军; 李滢; 臧新杰; 应良

    2012-01-01

    Objective To investigate the clinical application of ultrasound biomicroscopy in the treatment of congenital corneal opacities.Methods Medical records of 20 eyes (15 patients) with congenital corneal opacity treated at our hospital from July 2004 to November 2011 were retrospectively reviewed.Best corrected visual acuity testing,intraocular pressure testing,slit-lamp anterior segment examination,fundus examination,slit-lamp microscopic photography,B scan examination,and ultrasound biomicroscopy were performed for analysis of complications of congenital corneal opacity and selection of surgical approaches.Results The ultrasound biomicroscopic examination showed that 5 eyes had no Descemet's membrane and corneal endothelium,20 eyes had anterior synechia,5 eyes had aniridia,3 eyes had loss of lens cortex,13 eyes had cataract,14 eyes had closed angle,and 3 eyes had pupillary membrane.14 of 20 eyes received surgical treatment,including penetrating keratoplasty combined with cataract extraction and trabeculectomy (5 eyes),penetrating keratoplasty combined with pupil angioplasty (3 eyes),penetrating keratoplasty combined with cataract extraction (3 eyes),penetrating keratoplasty combined with trabeculectomy (2 eyes),and lamellar keratoplasty (1 eye).Conclusions Ultrasound biomicroscopy is important to guide the diagnosis and treatment of congenital corneal opacity.%目的 探讨超声生物显微镜在治疗先天性角膜混浊的临床应用.方法 回顾分析2004年7月至2011年11月于我院收治的先天性角膜混浊患者15例20只眼,常规行最佳矫正视力检查、眼压检查、裂隙灯眼前节检查、眼底检查、大体照相、B型超声检查、超声生物显微镜检查,分析先天性角膜混浊的并发症及手术方式情况.结果 根据超声生物显微镜检查结果,先天性角膜混浊患者伴有角膜无后弹力膜和内皮层者5只眼,虹膜前粘连(Peter异常)者20只眼,虹膜缺损者5只眼,晶体皮质丢失者3

  6. QR码技术在图书馆中的应用——以OPAC为例%Applications of QR Codes Technology in Libraries - A Case Analysis of OPAC

    Institute of Scientific and Technical Information of China (English)

    刘丹

    2012-01-01

    随着智能手机的广泛使用,QR码技术在图书馆有了更广的应用空间.虽然是一种简单易行的技术,它的采用却能很好地拓展图书馆服务.文章对QR码技术基本概念、特点及其在图书馆中的应用方式进行了简要的介绍,并给出了一个在OPAC中嵌入QR码的实例.%With die rapid development of smartphones, QR codes, a simple but powerful technology, are more widely used in libraries. We give a brief introduction about its fundamentals, features and applications as well as an implementation in OPAC.

  7. La aspiración y la pérdida de /s/ en el español de Chile como ejemplo de opacidad (Chilean /s/ aspiration and deletion as an example of phonological opacity

    Directory of Open Access Journals (Sweden)

    Karolina Bros

    2013-12-01

    Full Text Available En este artículo se estudia la llamada aspiración de /s/ implosiva y su pérdida en una variedad del español contemporáneo encontrada en Chile. El concepto de debilitamiento del fonema /s/ se presentará en términos generales, seguido por la presentación del problema dentro de los principales marcos teóricos desde los años 90 del siglo XX hasta hoy en día. El análisis demostrará que una combinación de conceptos propuestos por fonólogos léxicos y de la teoría de la marcación de rasgos fonológicos es el camino correcto hacia la resolución del problema de la opacidad de los procesos fonológicos experimentados en el español de Chile, la derivación siendo el término clave en el reanálisis del chileno dentro del marco de la Teoría Derivacional de la Optimidad. (This article examines the so-called s-aspiration as well as s-deletion in Chilean Spanish. It analyses these phonological processes as segment weakening in interaction with resyllabification across word boundaries, and then moves on to the presentation of Chilean opacity in various theoretical frameworks prevailing throughout the 1990s and the beginning of the 21st century. This article demonstrates that a combination of concepts introduced by lexical phonologists and markedness governing the optimality framework is the correct path to follow in the analysis of Chilean opacity effects, with derivation playing a crucial role in their reanalysis within the framework of Derivational Optimality Theory.

  8. Research on bovine corneal opacity and permeability test integrating with histopathological evaluation%结合组织学评分的牛角膜浑浊和渗透性方法研究

    Institute of Scientific and Technical Information of China (English)

    陈彧; 喻欢; 程树军; 谈伟君; 秦瑶

    2016-01-01

    为了优化替代眼刺激动物试验的牛角膜浑浊和渗透性(BCOP)实验的方法,提高其适用范围和预测性,选取新鲜牛眼角膜,直接暴露液体化学受试物作用10 min,后孵育2 h并用荧光素钠处理90 min,采用浊度仪检测角膜浑浊度,用酶标仪检测荧光素钠渗透性,同时将角膜常规固定和制备组织学切片,观察组织学病理变化并评分,基于上述3个指标建立预测模型。结果显示,将角膜浑浊度和渗透性2个定量指标,与角膜上皮组织、基质组织和内皮细胞的组织学变化评分进行组合,可对轻微刺激到中等刺激的范围进行准确细分。研究表明,结合组织学观察的优化BCOP方法可提高其预测性,适用于眼刺激机制研究和化妆品评估。%In order to refine the alternative method for animal eye irritation test———the bovine corneal opacity and permeability (BCOP)test,and to enhance its application scope and predictability,the fresh bovine corneas were chosen and directly exposed to liquid chemical material to be tested for 10 min,post - incubated for 2 h and further treated with fluorescein sodium for 90 min. Then opacity of the treated corneas was measured with opacitometer;the permeability was determined with the multiskan spectrum microplate spectrophotometer and the histopathological changes of the cornea were observed and graded after routinely fixed and paraffin embedding. Finally,the predictive models based on the above three indices were established. The results showed that the corneal opacity and permeability,integrated with histopathological changes of epithelium, stroma and endothelium,the scope of irritation from mild level to moderate level can be accurately distinguished. In conclusion,the refined BCOP method integrated with histological observation could improve its predictability and suitable for study of eye irritation mechanism and cosmetic product evaluation.

  9. Evaluation of the extent of ground-glass opacity on high-resolution CT in patients with interstitial pneumonia associated with systemic sclerosis: comparison between quantitative and qualitative analysis.

    Science.gov (United States)

    Yabuuchi, H; Matsuo, Y; Tsukamoto, H; Horiuchi, T; Sunami, S; Kamitani, T; Jinnouchi, M; Nagao, M; Akashi, K; Honda, H

    2014-07-01

    To verify whether quantitative analysis of the extent of ground-glass opacity (GGO) on high-resolution computed tomography (HRCT) could show a stronger correlation with the therapeutic response of interstitial pneumonia (IP) associated with systemic sclerosis (SSc) compared with qualitative analysis. Seventeen patients with IP associated with SSc received autologous peripheral blood stem cell transplantation (auto-PBSCT) and were followed up using HRCT and pulmonary function tests. Two thoracic radiologists assessed the extent of GGO on HRCT using a workstation. Therapeutic effect was assessed using the change of vital capacity (VC) and diffusing capacity of the lung for carbon monoxide (DLco) before and 12 months after PBSCT. Interobserver agreement was assessed using Spearman's rank correlation coefficient and the Bland-Altman method. Correlation with the therapeutic response between quantitative and qualitative analysis was assessed with Pearson's correlation coefficients. Spearman's rank correlation coefficient showed good agreement, but Bland-Altman plots showed that proportional error could be suspected. Quantitative analysis showed stronger correlation than the qualitative analysis based on the relationships between the change in extent of GGO and VC, and change in extent of GGO and DLco. Quantitative analysis of the change in extent of GGO showed stronger correlation with the therapeutic response of IP with SSc after auto-PBSCT than with the qualitative analysis. Copyright © 2014 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  10. A non-randomized confirmatory trial of segmentectomy for clinical T1N0 lung cancer with dominant ground glass opacity based on thin-section computed tomography (JCOG1211).

    Science.gov (United States)

    Aokage, Keiju; Saji, Hisashi; Suzuki, Kenji; Mizutani, Tomonori; Katayama, Hiroshi; Shibata, Taro; Watanabe, Syunichi; Asamura, Hisao

    2017-05-01

    Lobectomy has been the standard surgery for even stage I lung cancer since the validity of limited resection for stage I lung cancer was denied by the randomized study reported in 1995. The aim of this non-randomized confirmatory going on since September 2013 is to confirm the efficacy of a segmentectomy for clinical T1N0 lung cancer with dominant ground glass opacity based on thin-slice computed tomography. A total of 390 patients from 42 Japanese institutions are recruited within 4 years. The primary endpoint of this study is a 5-year relapse-free survival in all of the patients who undergo a segmentectomy for a lung nodule. The secondary endpoints are overall survival, annual relapse-free survival, disease-free survival, proportion of local relapse, postoperative pulmonary function, proportion of segmentectomy completion, proportion of R0 resection completion by segmentectomy, adverse events, and serious adverse events. This trial has been registered at the UMIN Clinical Trials Registry as UMIN000011819 ( http://www.umin.ac.jp/ctr/ ). Patient's accrual has been already finished in November, 2015 and the primary analysis will be performed in 2021. This study is one of the pivotal trial of lung segmentectomy for early lung cancer. The result will provide a clear evidence for our daily clinics and will be possible contribution to preserving pulmonary function for lung cancer patients.

  11. Mass loss from inhomogeneous hot star winds III. An effective-opacity formalism for line radiative transfer in accelerating, clumped two-component media, and first results on theory and diagnostics

    CERN Document Server

    Sundqvist, J O; Owocki, S P

    2014-01-01

    [Abridged] We develop and benchmark a fast and easy-to-use effective-opacity formalism for line and continuum radiative transfer in an accelerating two-component clumpy medium. The formalism bridges the limits of optically thin and thick clumps, and is here used to i) design a simple vorosity-modified Sobolev with exact integration (vmSEI) method for analyzing UV wind resonance lines in hot, massive stars, and ii) derive simple correction factors to the line force driving the outflows of such stars. We show that (for a given ionization factor) UV resonance doublets may be used to analytically predict the upward corrections in empirically inferred mass-loss rates associated with porosity in velocity space (a.k.a. velocity-porosity, or vorosity), but that severe solution degeneracies exist. For an inter-clump density set to 1 % of the mean density, we for O and B supergiants derive upward empirical mass-loss corrections of typically factors of either ~5 or ~50, depending on which of the two applicable solutions...

  12. Thin-section computed tomography-histopathologic comparisons of pulmonary focal interstitial fibrosis, atypical adenomatous hyperplasia, adenocarcinoma in situ, and minimally invasive adenocarcinoma with pure ground-glass opacity.

    Science.gov (United States)

    Si, Ming-Jue; Tao, Xiao-Feng; Du, Guang-Ye; Cai, Ling-Ling; Han, Hong-Xiu; Liang, Xi-Zi; Zhao, Jiang-Min

    2016-10-01

    To retrospectively compare focal interstitial fibrosis (FIF), atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), and minimally invasive adenocarcinoma (MIA) with pure ground-glass opacity (GGO) using thin-section computed tomography (CT). Sixty pathologically confirmed cases were reviewed including 7 cases of FIF, 17 of AAH, 23of AIS, and 13 of MIA. All nodules kept pure ground glass appearances before surgical resection and their last time of thin-section CT imaging data before operation were collected. Differences of patient demographics and CT features were compared among these four types of lesions. FIF occurred more frequently in males and smokers while the others occurred more frequently in female nonsmokers. Nodule size was significant larger in MIA (P0.05) in age, malignant history, attenuation value, location, and presence of bubble-like lucency. A nodule size >7.5mm increases the possibility of MIA. A concave margin could be useful for differentiation of FIF from the other malignant or pre-malignant GGO nodules. The presence of spiculation or pleural indentation may preclude the diagnosis of AAH. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Initial experimental demonstration of the principles of a xenon gas shield designed to protect optical components from soft x-ray induced opacity (blanking) in high energy density experiments

    Science.gov (United States)

    Swadling, G. F.; Ross, J. S.; Manha, D.; Galbraith, J.; Datte, P.; Sorce, C.; Katz, J.; Froula, D. H.; Widmann, K.; Jones, O. S.; Divol, L.; Landen, O. L.; Kilkenny, J. D.; Moody, J. D.

    2017-03-01

    The design principles of a xenon gas shield device that is intended to protect optical components from x-ray induced opacity ("x-ray blanking") have been experimentally demonstrated at the OMEGA-60 Laser Facility at the Laboratory for Laser Energetics, University of Rochester. A volume of xenon gas placed in front of an optical component absorbs the incoming soft x-ray radiation but transmits optical and ultra-violet radiation. The time-resolved optical (532 nm) transmission of samples was recorded as they were exposed to soft x-rays produced by a gold sphere source (1.5 kJ sr-1, 250-300 eV). Blanking of fused silica (SiO2) was measured to occur over a range of time-integrated soft x-ray (nitride (Si3N4) and a 10 cm long volume of 0.04 bar xenon gas succeeded in delaying loss of transmission through a magnesium fluoride sample; optical transmission was observed over a longer period than for the unprotected sample. It is hoped that the design of this x-ray shield can be scaled in order to produce a shield device for the National Ignition Facility optical Thomson scattering collection telescope, in order to allow measurements of hohlraum plasma conditions produced in inertial confinement fusion experiments. If successful, it will also have applications in many other high energy density experiments where optical and ultra-violet measurements are desirable.

  14. The Resource Integration of Library Based on OPAC Search Function%基于OPAC系统检索功能的图书馆资源整合研究

    Institute of Scientific and Technical Information of China (English)

    王庆娟

    2012-01-01

    In the digital library,the contradiction between the increasing digital resources and the failure to make full use of them become increasingly prominent,and computer technology and new generation of search engine are important means to resolve these problems.According to the present situations of library resources,the paper uses the concepts of the new technologies,such as web search engine,visual search engine,audio search engine and personalized search engine,to integrate the electronic resources of library into the search functions of OPAC,aiming at providing a new idea for solving the problems and making it easy to use the resources.%步入数字图书馆时代,电子资源的日益增多与电子文献无法充分被利用的矛盾日益突出,运用计算机技术和新一代搜索引擎技术是解决该矛盾的重要手段。文章结合图书馆资源的现状,运用网络搜索引擎、可视化搜索引擎、音频搜索引擎、个性化搜索引擎等各类搜索引擎的新科技特点和新服务理念,将图书馆的电子资源尽可能地整合在OPAC系统的检索功能里,成为解决该矛盾的一个新思路,为更加简便、直观地利用图书馆资源指明了新方向。

  15. Survey of ocular irritation predictive capacity using Chorioallantoic Membrane Vascular Assay (CAMVA) and Bovine Corneal Opacity and Permeability (BCOP) test historical data for 319 personal care products over fourteen years.

    Science.gov (United States)

    Donahue, D A; Kaufman, L E; Avalos, J; Simion, F A; Cerven, D R

    2011-03-01

    The Chorioallantoic Membrane Vascular Assay (CAMVA) and Bovine Corneal Opacity and Permeability (BCOP) test are widely used to predict ocular irritation potential for consumer-use products. These in vitro assays do not require live animals, produce reliable predictive data for defined applicability domains compared to the Draize rabbit eye test, and are rapid and inexpensive. Data from 304 CAMVA and/or BCOP studies (319 formulations) were surveyed to determine the feasibility of predicting ocular irritation potential for various formulations. Hair shampoos, skin cleansers, and ethanol-based hair styling sprays were repeatedly predicted to be ocular irritants (accuracy rate=0.90-1.00), with skin cleanser and hair shampoo irritation largely dependent on surfactant species and concentration. Conversely, skin lotions/moisturizers and hair styling gels/lotions were repeatedly predicted to be non-irritants (accuracy rate=0.92 and 0.82, respectively). For hair shampoos, ethanol-based hair stylers, skin cleansers, and skin lotions/moisturizers, future ocular irritation testing (i.e., CAMVA/BCOP) can be nearly eliminated if new formulations are systematically compared to those previously tested using a defined decision tree. For other tested product categories, new formulations should continue to be evaluated in CAMVA/BCOP for ocular irritation potential because either the historical data exhibit significant variability (hair conditioners and mousses) or the historical sample size is too small to permit definitive conclusions (deodorants, make-up removers, massage oils, facial masks, body sprays, and other hair styling products). All decision tree conclusions should be made within a conservative weight-of-evidence context, considering the reported limitations of the BCOP test for alcohols, ketones, and solids.

  16. Opacity and Transparency in Phonological Change

    Science.gov (United States)

    Gress-Wright, Jonathan

    2010-01-01

    Final obstruent devoicing is attested in both Middle and Modern High German, and the modern rule is usually assumed to have been directly inherited from the medieval rule without any chronological break (Reichmann & Wegera 1993), despite the fact that the graphic representation of final devoicing ceased in the Early Modern period. However, an…

  17. Hydro-dissection and posterior capsule opacity

    African Journals Online (AJOL)

    Windows2G

    Its use is therefore encouraged but with generous use of viscoelastic material to reduce effect of manipulation on the eye. ... possible for between 5-10 minutes to ensure a soft eye before surgery. .... Shentu X, Yao K, Sun Z, Yu H, Yang Y: The.

  18. Alternative Metal Hot Cutting Operations for Opacity

    Science.gov (United States)

    2014-11-01

    testing was conducted on 9/32” ordinary strength steel bulkhead section from the ex-CGN-9 and, if possible, 2” high yield strength steel ( HY80 ...recorded for both the alternative fuel and propane. Test cuts were on 9/32” steel surface ship sections with additional demonstration cuts performed on...thicker surface ship sections and 2” high yield strength steel submarine pressure hull as the pieces became available. The results from the

  19. Production of a corneal opacity mouse by N-ethyl-N-nitrosourea mutagenesis and chromosome mapping of the mutant gene%乙酰基亚硝基脲诱变的一种角膜混浊小鼠及其突变基因的染色体定位

    Institute of Scientific and Technical Information of China (English)

    陈兵; 糜婷; 倪俊达; 耿滕; 薛整风

    2014-01-01

    背景 乙酰基亚硝基脲(ENU)诱导小鼠基因突变是研究基因功能及建立人类疾病动物模型的一种有效手段. 目的 研究ENU诱变获得的1只角膜混浊小鼠角膜组织形态变化,并对其突变基因进行染色体定位.方法 选用8~10周龄的C57BL/6J (B6)雄鼠40只,腹腔内注射ENU.将注射后的雄鼠与同品系母鼠交配,在其后代小鼠中筛选眼部突变个体,并将突变个体与同品系小鼠配种以确定是否遗传.对ENU诱变获得1只角膜混浊小鼠的角膜行组织病理学观察.繁殖[(B6×D2) F1×B6] N2角膜混浊小鼠,用平均分布于小鼠染色体上的微卫星标记对N2小鼠染色体进行扫描.采用优势对数计分法(LOD)判定突变基因与微卫星是否连锁. 结果 将角膜呈现混浊小鼠与B6背景小鼠配种,在其59只后代中出现19只类似表型的突变小鼠.角膜组织病理学检查发现,该例角膜混浊小鼠角膜基质增厚,出现新生血管和炎性细胞浸润,成纤维细胞明显增多.突变基因与微卫星间的连锁分析发现,26个N2样品中突变基因与位于小鼠2号染色体63.42 cM处的D2Mi307位点发生3例交换,LOD值为3.79,该突变基因位于小鼠第2号染色体. 结论 成功获得角膜混浊小鼠并将其突变基因初步定位于2号染色体,有望为人类角膜混浊疾病研究提供一种新的小鼠模型.%Background N-ethyl-N-nitrosourea (ENU)-induced mouse mutagenesis is a powerful approach for the study of gene function and the generation of human disease models.Objective This study was to create the corneal morphologic change and map the mutant gene of a kind of corneal opacity in ENU mutagenesis in mouse.Methods ENU was intraperitoneally injected in forty C57BL/ 6J (B6) male mice aged 8-10 weeks old.The male mice were mated with the same strain female mice.Their progenies were screened for visible eye mutation,and the mutant mice were mated with the same strain mice to confirm the heredity of

  20. Opacidades em vidro fosco nas doenças pulmonares difusas: correlação da tomografia computadorizada de alta resolução com a anatomopatologia Ground-glass opacity in diffuse lung diseases: high-resolution computed tomography-pathology correlation

    Directory of Open Access Journals (Sweden)

    Maria Lúcia de Oliveira Santos

    2003-12-01

    Full Text Available Opacidade em vidro fosco é achado freqüentemente visto na tomografia computadorizada de alta resolução do tórax e se traduz pelo aumento do coeficiente de atenuação dos pulmões, mas sem apagar as marcas broncovasculares. Por sua inespecificidade, a associação com outros achados radiológicos, clínicos e anatomopatológicos deve ser considerada para uma interpretação diagnóstica mais correta. Neste trabalho foram analisados 62 exames tomográficos de pacientes com doenças pulmonares difusas, de 14 etiologias diferentes, em que opacidades em vidro fosco foram o achado único ou predominante, e feita correlação anatomopatológica por meio de biópsias ou necropsias. Na pneumocistose as opacidades em vidro fosco corresponderam, histologicamente, à ocupação alveolar por material espumoso contendo parasitos; no carcinoma bronquíolo-alveolar, a espessamento dos septos alveolares e ocupação de sua luz por muco e células tumorais; na paracoccidioidomicose, a espessamento dos septos alveolares, áreas de fibrose e alvéolos contendo exsudato broncopneumônico; na sarcoidose, a fibrose ou a acúmulo de granulomas; na fibrose pulmonar idiopática, a espessamento dos septos alveolares por fibrose; na bronquiolite obliterante com pneumonia em organização, a pneumonia intersticial com áreas de organização intra-alveolar. A ocupação alveolar por sangue foi observada nos casos de leptospirose, hemossiderose idiopática, metástases de tumor renal e na aspergilose invasiva; por vacúolos de gordura na pneumonia lipídica; por material protéico e lipoprotéico na silicoproteinose e na proteinose alveolar; e por líquido de edema na insuficiência cardíaca congestiva.Ground-glass opacity is a finding frequently seen in high-resolution computed tomography examinations of the chest and is characterized by hazy increased attenuation of lung, however without blurring of bronchial and vascular margins. Due to its unspecificity

  1. Lacking applicability of in vitro eye irritation methods to identify seriously eye irritating agrochemical formulations: Results of bovine cornea opacity and permeability assay, isolated chicken eye test and the EpiOcular™ ET-50 method to classify according to UN GHS.

    Science.gov (United States)

    Kolle, Susanne N; Van Cott, Andrew; van Ravenzwaay, Bennard; Landsiedel, Robert

    2017-04-01

    In vitro methods have gained regulatory acceptance for the prediction of serious eye damage (UN GHS Cat 1). However, the majority of in vitro methods do not state whether they are applicable to agrochemical formulations. This manuscript presents a study of up to 27 agrochemical formulations tested in three in vitro assays (three versions of the bovine corneal opacity and permeability test (BCOP, OECD TG 437) assay, the isolated chicken eye test (ICE, OECD TG 438) and the EpiOcular™ ET-50 assay). The results were compared with already-available in vivo data. In the BCOP only one of the four, one of five in the ICE and six of eleven tested formulations in the EpiOcular™ ET-50 Neat Protocol resulted in the correct UN GHS Cat 1 prediction. Overpredictions occurred in all assays. These data indicate a lack of applicability of the three in vitro methods to reliably predict UN GHS Cat 1 of agrochemical formulations. In order to ensure animal-free identification of seriously eye damaging agrochemical formulations testing protocols and/or prediction models need to be modified or classification rules should be tailored to in vitro testing rather than using in vivo Draize data as a standard. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  2. The clinical value of CT guidance Hook-wire positioning thoracoscopic surgery for ground-glass opacity lung nodules%术前CT引导下Hook-wire定位胸腔镜切除肺毛玻璃样结节临床研究

    Institute of Scientific and Technical Information of China (English)

    邓俊; 仲宁; 陈文

    2016-01-01

    目的:探讨CT引导下Hook-wire术前定位肺磨玻璃样结节(GGO)在胸腔镜切除术中的应用。方法:25例肺GGO患者均术前行Hook-wire定位,行胸腔镜肺楔形切除术。根据术中冰冻病理结果决定下一步治疗方式。结果:肺GGO直径为(11.48±3.50)mm,距离壁层胸膜(16.52±5.98)mm。CT引导肺GGO Hook-wire定位均成功,定位时间(15.04±3.38)min,出现微量气胸5例(占20%),均不需放置引流管,1例出现少许肺实质出血(占4.00%),无一例出现定位针脱落,实施胸腔镜肺楔形切除100%,其中12例单纯行胸腔镜肺楔形切除手术时间为(21.67±3.94)min,13例为浸润性腺癌,行胸腔镜肺叶或是肺段切除及淋巴结清扫术,手术时间为(58.84±12.01)min。结论:术前CT引导下Hook-wire定位是一种安全可靠且容易掌握的临床技术,降低了手术时间,并发症少,值得临床推广应用。%Objective: To evaluate the clinical application of guidance Hook-wire positioning for ground-glass opacity before video-assisted thoracoscopic resection.Methods: Preoperative location of 25 patients with ground-glass opacity lung nodules was performed using CT-guided Hook-wire technique. Video assisted tho-racic surgery (VATS) pulmonary wedge resection was adopted. According to the result of intraoperative frozen pathology, the next mode of operation was adopted.Results: GGO diameter (11.48±3.50) mm, diatance from the parietal pleura (16.52±5.98) mm. Twenty ifve patients were successfully located. The mean procedure time for preoperative CT-guided Hook-wire location was (15.04±3.38) min. 5 patients had micro pneumothroax after positioning. The chest tube drainage was not required. One patient had minimal needle tract parenchymal hemor-rhages. No one occured migration and fall out of the hookwire. VATS wedge resection surgery successful rate was 100%. Twelve cases of pure thoracoscopy pulmonary wedge

  3. Opacity of electromagnetically induced transparency for quantum fluctuations

    CERN Document Server

    Barberis-Blostein, P

    2007-01-01

    We analyze the propagation of a pair of quantized fields inside a medium of three-level atoms in $\\Lambda$ configuration. We calculate the stationary quadrature noise spectrum of the field after propagating through the medium, in the case where the probe field is in a squeezed state and the atoms show electromagnetically induced transparency (EIT). We find an oscillatory transfer of the initial quantum properties between the probe and pump fields which is most strongly pronounced when both fields have comparable Rabi frequencies. This implies that the quantum state measured after propagation can be completely different from the initial state, even though the mean values of the field are unaltered.

  4. A Method for Visualizing Transaction Logs of a Faceted OPAC

    Directory of Open Access Journals (Sweden)

    Xi Niu

    2010-12-01

    Full Text Available The authors introduce a method for visualizing user transaction logs from a library catalog application. Simple visualization supporting intuitive or qualitative analysis to quickly make sense of complicated patterns can be a useful supplement or alternative to more common quantitative analysis. To this end, a visual flowchart is created illustrating an individual user session. This visualization can be used to qualitatively grasp user behavior within the application, possibly as an aid to identifying patterns or clusters of use. These flowcharts are created by automatically pre-processing apache transaction logs into an XML representation of meaningful user actions, which are then converted via JavaScript in a web browser to HTML table based flowcharts. The particular toolkit introduced is named Visualization for Understanding Transaction Logs (VUTL, and is available with an open source license. The toolkit has been prototyped with logs from the catalog applications of several academic and one public library.

  5. Opacity in complex systems; Opacidade em sistemas complexos

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Vaner Diniz de [IBERDROLA, Rio de Janeiro, RJ (Brazil); Melo, Paulo Fernando Frutuoso e [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

    2005-07-01

    This paper tries to explain why operators have difficult situations when an emergency takes place; complexity has always existed and is not only consequence of high technology as most people try to point out. One of the reasons for this problem is given by the design engineering people beliefs in mechanical paradigms, considering high technology resources without worrying about the limitations related to the operators. Another aspect of relevant importance is the necessity of reviewing the cognitive processes studies taking into consideration that the old ones, as an example THERP (Technique for Human Error Rate Prediction), were based on technological researches developed at that time (1980{sup th}). It is important to emphasize that, for the moment, risk studies continue applying such a technology. (author)

  6. Referential Opacity and Hermeneutics in Plato’s Dialogue Form

    Directory of Open Access Journals (Sweden)

    Richard McDonough

    2013-12-01

    Full Text Available The paper argues that Plato’s dialogue form creates a Quinean “opaque context” that segregates the assertions by Plato’s characters in the dialogues from both Plato and the real world with the result that the dialogues require a hermeneutical interpretation. Sec. I argues that since the assertions in the dialogues are located inside an opaque context, the forms of life of the characters in the dialogues acquires primary philosophical importance for Plato. The second section argues that the thesis of Sec. I coheres with the claim in Plato’s Seventh Letter that since philosophical truth is incommunicable by means of language it is of primary importance for philosophers to develop proper “schemes of living” (forms of life. Sec. III argues since the forms of life of the characters portrayed in the dialogues is of primary philosophical importance for Plato, and since hermeneutical methods are required to interpret emerging forms of life, Plato’s dialogues are positively crafted to be read hermeneutically. Sec IV argues that Heidegger, who is famous for seeing Plato’s views as antithetical to his own hermeneutical approach, is mistaken, and that Plato’s real views are, in principle, more akin to Heidegger’s views than he thinks.

  7. Enhancement of Digital Methods for Determination of Opacity

    Science.gov (United States)

    2007-09-21

    background conditions before it could be more widely accepted. We submitted a peer-reviewed publication to Environmental Science & Technology describing...for stacks. In addition, we submitted the results of this work to journal, Environmental Science & Technology . 19 6. LITERATURE CITED

  8. Echinococcal disease in Alberta, Canada: more than a calcified opacity

    Directory of Open Access Journals (Sweden)

    Bhargava Ravi

    2005-05-01

    Full Text Available Abstract Background Most cases of echinococcal disease (ED acquired in Canada are thought to be due to the sylvatic form of Echinococcus granulosus, which may be more benign than ED due to either Echinococcus multilocularis or the pastoral form of E. granulosus. There are limited descriptions of the clinical course and outcome of Canadian patients with ED in the modern era. Methods A retrospective chart review was performed of patients hospitalized with echinococcal disease (ED from 1991 to 2001 in Edmonton, Alberta. Results Forty-two cases of ED were identified of which 19 were definite, 3 probable, and 20 possible. Further analysis was limited to the 22 definite and probable cases, of which 77% were female and 41% aboriginal, with an age range of 5 to 87 years. Nine patients (40% had pulmonary involvement and 11 (50% hepatic involvement. One patient had an intracardiac mass presenting as a cerebrovascular event and one had a splenic cyst. Seven of the 22 patients had combined surgical resection and medical treatment, six had surgical resection of the cyst alone, four had cyst aspiration, one had medical treatment alone and four had no specific treatment. There was no mortality attributable to ED but three patients died of unrelated illnesses. Conclusion Echinococcal disease in northern Alberta has a marked diversity of clinical presentations, and generally has a good prognosis despite a wide variety of therapeutic interventions.

  9. Acoustic transparency and opacity using Fano Interferences in Metamaterials

    KAUST Repository

    Khelif, A.

    2015-08-04

    We investigate both experimentally and theoretically how to generate the acoustical analogue of the Electromagnetically Induced Transparency. This phenomenon arises from Fano resonances originating from constructive and destructive interferences of a narrow discrete resonance with a broad spectral line or continuum. Measurements were realized on a double-cavity structure by using a Kundt’s Tube. Transmission properties reveal an asymmetric lineshape of the transmission that leads to acoustic transparency.

  10. Controlled opacity in a class of nonlinear dielectric media

    CERN Document Server

    Bittencourt, Eduardo; De Lorenci, Vitorio A; Klippert, Renato

    2016-01-01

    Motivated by new technologies on designing and tailoring metamaterials, we seek for properties of certain classes of nonlinear optical materials that allow room for a reversibly controlled opacityto-transparency phase transition through the application of external electromagnetic fields. We examine some mathematically simple models for the dielectric parameters of the medium, and compute the relevant geometric quantities that describe the speed and polarization of light rays.

  11. Experimental Investigation of the Opacity of Small Particles

    Science.gov (United States)

    1965-04-01

    16. Anonymous: Cabot Carbon Blacks under the Electron Microscope, 2nd Ed. Cabot Corporation, Boston, November 1953. 17. Smoluchowski, M.: Zeitschrift ...fur Physikalische Chemie, Vol. 92, 1917, p. 129. 18. Devir, S.: On the Coagulation of Aerosols (Part I). Journal of Colloid Science, Vol. 18, No. 8

  12. Analysis of OPACITY and PLAID Protocols for Contactless Smart Cards

    Science.gov (United States)

    2012-09-01

    of contactless technologies, such as RFID . Contactless smart cards contain a re-writable smart card microchip that is used to read or write via...technology: comparing and contrasting rfid and rf-enabled smart cards ,” [6] P. Oswal and M. Foong, “ RFID vs contactless smart cards - an unending debate...AND PLAID PROTOCOLS FOR CONTACTLESS SMART CARDS by Koh Ho Kiat Lee Yong Run September 2012 Thesis Co-Advisors

  13. Transparency and Opacity: Levinasian Reflections on Accountability in Australian Schooling

    Science.gov (United States)

    Sellar, Sam

    2015-01-01

    This article draws on the philosophy of Emmanuel Levinas to consider, from an ethical perspective, the current transparency and accountability agenda in Australian schooling. It focuses on the case of the "My School" website and the argument that transparent publication of comparative performance data via the website provides a basis for…

  14. Enhancing Subject Access to OPACs: Controlled Vocabulary vs. Natural Language.

    Science.gov (United States)

    Cousins, Shirley Anne

    1992-01-01

    Investigation of retrieval performance of controlled vocabulary derived from natural language terms in tables of contents and book indexes assumed that controlled vocabulary representative of users' queries should adequately represent documents' contents. Queries were indexed using Library of Congress Subject Headings (LSCH), Dewey Decimal…

  15. Accounting for highly excited states in detailed opacity calculations

    CERN Document Server

    Pain, Jean-Christophe

    2015-01-01

    In multiply-charged ion plasmas, a significant number of electrons may occupy high-energy orbitals. These "Rydberg" electrons, when they act as spectators, are responsible for a number of satellites of X-ray absorption or emission lines, yielding a broadening of the red wing of the resonance lines. The contribution of such satellite lines may be important, because of the high degeneracy of the relevant excited configurations which give these large Boltzmann weights. However, it is in general difficult to take these configurations into account since they are likely to give rise to a large number of lines. We propose to model the perturbation induced by the spectators in a way similar to the Partially-Resolved-Transition-Array approach recently published by C. Iglesias. It consists in a partial detailed-line-accounting calculation in which the effect of the Rydberg spectators is included through a shift and width, expressed in terms of the canonical partition functions, which are key-ingredients of the Super-Tr...

  16. Clinical Study of Intra-operative Computed Tomography Guided Localization with A Hook-wire System for Small Ground Glass Opacities in Minimally Invasive Resection%CT引导下Hook-w ire定位肺磨玻璃样微小结节微创切除的临床研究

    Institute of Scientific and Technical Information of China (English)

    初向阳; 侯晓彬; 张连斌; 薛志强; 任志鹏; 温佳新; 刘毅; 马克峰; 孙玉鹗

    2014-01-01

    Background and objective Localization of pulmonary ground glass small nodule is the technical dif-ficulty of minimally invasive operation resection. The aim of this study is to evaluate the value of intraoperative computed tomography (CT)-guided localization using a hook-wire system for small ground glass opacity (GGO) in minimally invasive resection, as well as to discuss the necessity and feasibility of surgical resection of small GGOs (<10 mm) through a minimally invasive approach.MethodshTe records of 32 patients with 41 small GGOs who underwent intraoperative CT-guided double-thorn hook wire localization prior to video-assisted thoracoscopic wedge resection from October 2009 to October 2013 were retrospectively reviewed. All patients received video-assisted thoracoscopic surgery (VATS) within 10 min atfer wire localiza-tion. hTe effcacy of intraoperative localization was evaluated in terms of procedure time, VATS success rate, and associated complications of localization.Results A total of 32 patients (15 males and 17 females) underwent 41 VATS resections, with 2 simultaneous nodule resections performed in 3 patients, 3 lesion resections in 1 patient, and 5 lesions in a patient. Nodule di-ameters ranged from 2 mm-10 mm (mean: 5 mm). hTe distance of lung lesions from the nearest pleural surfaces ranged within 5 mm-24 mm (mean: 12.5 mm). All resections of lesions guided by the inserted hook wires were successfully performed by VATS (100% success rate). hTe mean procedure time for the CT-guided hook wire localization was 8.4 min (range: 4 min-18 min). hTe mean procedure time for VATS was 32 min (range: 14 min-98 min). hTe median hospital time was 8 d (range: 5 d-14 d). Results of pathological examination revealed 28 primary lung cancers, 9 atypical adenomatous hyperplasia, and 4 nonspe-ciifc chronic inlfammations. No major complication related to the intraoperative hook wire localization and VATS was noted. Conclusion Intraoperative CT-guided hook wire

  17. 胸腔镜术前低剂量CT引导下Hook-wire联合亚甲蓝定位肺局灶性磨玻璃样病变%Low-dose CT-guided Localization with a Hook-wire System Combined with Methylene Blue for Focal Ground-glass Opacity before Video-assisted Thoracoscopic Resection

    Institute of Scientific and Technical Information of China (English)

    王玉涛; 王海涛; 赵晓东; 朱勇刚; 周成伟; 卢斌; 周银杰; 葛明亮; 张霞萍; 邓生德

    2012-01-01

    To evaluate low-dose CT ( LDCT)-guided localization by using Hook-wire combined with methylene blue before video-assisted thoracoscopic surgery for pulmonary focal ground-glass opacity (fGGO). Methods From November 2010 to April 2012, we performed video-assisted thoracoscopic wedge resection of the lung on 21 patients with unilateral fGGO (the diameter of fGGO ranged from 5 to 17 mm with a mean of 11.5 mm, and the distance between the parietal pleura and the lesion was 0 to 28 mm). All the patients received LDCT-guided localization with Hook-wire and methylene blue. Results The success rate of LDCT-guided localization was 100%. The procedure was completed in a mean of 21 min (ranged from 15 to 28 min). Intraoperative metal hook shedding occurred in one of the cases, but with video-assisted thoracoscopy and staining with methylene blue to localize the lesion, the resection was completed successfully. In the other case, methylene blue staining failed, but the fGGO was removed by localizing the lesion with Hook-wire. Six patients developed postoperative complications, including asymptomatic pneumothorax (4 cases) , asymptomatic bleeding in the left upper lobe (1 case) , and asymptomatic pneumothorax complicated with right lower lobe hemorrhage (1 case). The mean operation time for video-assisted thoracoscopic surgery was 22 min (15 - 43 min) , and the mean intraoperative blood loss was 31 ml (23 -38 ml). The patients were discharged from hospital in a mean of 7 days after the procedure (5-12 days). Postoperative pathological examination showed carcinoma in situ in 4 cases, microinvasive adenocarcinoma in 3 cases, pulmonary adenocarcinoma in 1, atypical adenomatous hyperplasia in 5, hamartoma in 1 , interstitial pneumonia in 3 , intrapulmonary lymph node hyperplasia in 2, and inflammatory granuloma in 2. Conclusion LDCT-guided localization by using Hook-wire combined with methylene blue is accurate for fGGO with mile complications.%目的 探讨低剂量CT( low-dose CT

  18. Monte Carlo simulations for thermodynamical properties calculations of plasmas at thermodynamical equilibrium. Applications to opacity and equation of state calculations; Apport d'un code de simulation Monte Carlo pour l'etude des proprietes thermodynamiques d'un plasma a l'equilibre et application au calcul de l'elargissement des profils de raies ioniques emises dans les plasmas denses, aux opacites spectrales et aux equations d'etat de systemes fluides

    Energy Technology Data Exchange (ETDEWEB)

    Gilles, D

    2005-07-01

    This report is devoted to illustrate the power of a Monte Carlo (MC) simulation code to study the thermodynamical properties of a plasma, composed of classical point particles at thermodynamical equilibrium. Such simulations can help us to manage successfully the challenge of taking into account 'exactly' all classical correlations between particles due to density effects, unlike analytical or semi-analytical approaches, often restricted to low dense plasmas. MC simulations results allow to cover, for laser or astrophysical applications, a wide range of thermodynamical conditions from more dense (and correlated) to less dense ones (where potentials are long ranged type). Therefore Yukawa potentials, with a Thomas-Fermi temperature- and density-dependent screening length, are used to describe the effective ion-ion potentials. In this report we present two MC codes ('PDE' and 'PUCE') and applications performed with these codes in different fields (spectroscopy, opacity, equation of state). Some examples of them are discussed and illustrated at the end of the report. (author)

  19. Non-Hodgkin's lymphoma with diffuse ground-glass opacity on chest CT: a report of 6 cases%影像学表现为双肺弥漫磨玻璃影的肺非霍奇金淋巴瘤的临床特点

    Institute of Scientific and Technical Information of China (English)

    秦岭; 施举红; 刘鸿瑞; 冯瑞娥; 柳涛; 李剑; 吕玮; 秦明伟

    2010-01-01

    目的 分析影像学表现为双肺弥漫磨玻璃影(GGO)的肺非霍奇金淋巴瘤的临床特点,以提高其诊断率.方法 回顾性分析北京协和医院2008年1月至2010年3月,胸部CT表现为双肺GGO的肺非霍奇金淋巴瘤的6例患者的资料.结果 6例患者中男5例,女1例,年龄30~59岁(平均52岁),病程2~36个月(平均14个月).临床表现为胸闷憋气5例,体重下降5例,浅表淋巴结肿大2例,肝脾肿大2例.血红蛋白平均下降25 g/L,血清乳酸脱氢酶平均755 U/L,3例患者肺功能为弥散功能障碍(一氧化碳弥散量平均为70%).影像学表现为单纯双肺GGO 2例、双肺GGO伴双肺实变影3例、伴小叶间隔增宽3例、伴小结节影2例、伴纵膈淋巴结肿大2例.6例患者均经肺组织活检病理确诊,其中4例为B细胞淋巴瘤(血管内淋巴瘤及弥漫大B细胞淋巴瘤各2例),2例为T细胞淋巴瘤.随访2~6个月(平均4个月),4例B细胞淋巴瘤患者化疗后病情平稳;2例T细胞淋巴瘤患者中1例未化疗失访,1例因合并重症肺部感染未能化疗,4个月后死亡.结论 以双肺GGO为首发影像学表现的肺非霍奇金淋巴瘤起病隐匿,少见,临床症状及影像学检查无特异性,肺活检是最终确诊的手段.%Objective To investigate the clinical, pathological and imaging characteristics,misdiagnosis and treatment of pulmonary non-Hodgkin's lymphoma with diffuse ground-glass opacities (GGO). Methods Six cases of pulmonary non-Hodgkin's lymphoma with diffuse GGO on chest CT diagnosed from January 2008 to March 2010 were retrospectively analyzed. Results There were 5 males and 1 female with average age of 52 years old ( range: 30-59). The course had a range of 2-36 months. Most patients presented with dyspnea ( n = 5) and loss of weight (n = 5). Enlargement of superficial lymph nodes ( n = 2) and hepatosplenomegaly (n = 2) were also found. Laboratory tests showed that average hemoglobin decreased to 25 g/L and average serum LDH

  20. 猪链球菌2型血清混浊因子基因的鉴定及其结构特征分析%Identification and Structure Features of Opacity Factor Genes from Two Streptococcus suis 2 Strains Originated from China and Japan

    Institute of Scientific and Technical Information of China (English)

    冯亚莉; 冉雪琴; 王嘉福; 钱龙

    2012-01-01

    猪链球菌是猪的主要病原,也可导致人感染,其致病机理尚未明确.作者设计了1对特异性引物,采用特异性PCR从2株猪链球菌血清2型606中国分离株和607日本分离株的基因组中,分离出2种血清混浊因子(of)基因,全长3 016 bp,编码938个氨基酸,其中日本分离株607的ofs基因序列与已知基因完全相同.中国分离株606的ofs基因与已知基因相差7个碱基,导致3个氨基酸替换,其中1个突变(Asp353Gly)位于蛋白的N端功能区,可能影响其血清混浊功能;另外2个氨基酸突变位于蛋白的C端重复区内.从2种OFS蛋白中,找出了细菌黏附因子共有的结构特征,2种OFS蛋白C端区含有保守的LPXTG结构,使OFS蛋白可固定于细菌的表面,但其中的3个重复序列与纤黏蛋白结合蛋白A等的相似性很低,两种OFS蛋白可能通过特殊的途径协助猪链球菌的黏附.猪链球菌ofs基因中重复序列和突变使得编码的蛋白表现出丰富的长度多态性.本研究获得的2种OFS属于中等长度的蛋白,均来自强毒力型猪链球菌.这些结果提示菌株606和607携带的ofs基因可能是猪链球菌的毒力基因,对猪链球菌的致病机理及其防治具有重要的意义.%Streptococcus suis is a swine pathogen which causes serious inflammation of piglets. It can infect people in contact with diseased pig or its by-products. The mechanisms of S. Suis path-ogenesis are poorly understood. Taking two S. Suis serotype 2 strains 606 isolated from China and 607 from Japan as samples, opacity factor of S. Suis (o/s) genes were amplified from the ge-nomic DNA of these bacteria by PCR method. The ofs genes contained 3 016 bp which encoded for 938 aa based on alignment analysis. The identity of nucleotide sequence of ofs gene from SS2 strain 607 was 100% to the reported SS2 genes while seven nucleotides in ofs of SS2 strain 606 were different and resulted in three amino acids substitution. One of the substitutions

  1. The correlationship between the content of bFGF in the aqueous humor and the development of PCO(posterior capsular opacity) following the joint operation of vitrectomy and C3 F8 tamponade on rabbit's eye%兔眼玻切及 C3 F8填充术后房水 bFGF含量与白内障形成的实验研究

    Institute of Scientific and Technical Information of China (English)

    王盟; 贾松柏

    2014-01-01

    Objective To investigate the possible correlationship between the content of bFGF in the aqueous humor and the development of PCO(posterior capsular opacity )following the joint operation of vitrectomy and C 3 F8 tamponade .Methods 18 adult and pure-breed New Zealand white rabbits were selected ,and all their 36 eyes as subjects of the experiment were taken .They were assigned into three groups randomly ,i .e .12 eyes per group . Blank control group would receive none operation .Control group which would undergo the vitrectomy .Experimen-tal group which would accept the joint operation of vitrectomy and C 3 F8 tamponade .Afterwards ,the development of PCO was observed and the bFGF content was measured in subject's aqueous humor on the next 1 ,3 ,8 ,35 ,45 days respectively .Results All subjects in blank control group and control group hadn't shown PCO during the experi-ment .All subjects in experimental group had shown PCO .The bFGF in control group and experimental group were significantly higher than blank control group .Experimental group was also higer than Control group throughtout the experimental period .Conclusion C3 F8 tamponade will raise the content of bFGF in the aqueous humor which may potentially contribute to the development of PCO .%目的:研究玻璃体切除联合全氟丙烷(C3 F8)填充术后形成白内障的兔房水碱性成纤维细胞生长因子(bFGF)含量变化与白内障形成之间的关系。方法18只成年纯系新西兰白兔(雌雄不限)的36只眼,随机平均分为3组:正常组,不做手术;对照组,行单纯玻璃体切除术及眼前房灌注液(BSS )填充;实验组,行玻璃体切除联合C3 F8填充术。术后第1,3,8,35及45天观察各组白内障的形成情况,并抽取房水用ELISA法检测房水中bFGF的含量。结果正常组与对照组均未出现晶体混浊,实验组均出现晶体混浊。术后不同时期,实验组与对照组的bFGF含量均明

  2. 从WorldCat及相关原型看新一代OPAC%The Prospect of Next Generation OPAC through WorldCat and Related Prototypes

    Institute of Scientific and Technical Information of China (English)

    刘颉颃

    2009-01-01

    OCLC Research项目中的WorldCat、FictionFinder、DeweyBwwser等原型为新一代OPAC的发展提供了借鉴,如检索、服务集成、数据提供、检索结果呈现、用户体验以及数据开放等功能的优化与重构.此外,新一代OPAC还应具有智能化与娱乐性的特征.

  3. 开源OPAC 2.0-VuFind应用研究%Application Research of Open Source OPAC 2.0 VuFind

    Institute of Scientific and Technical Information of China (English)

    张平杉

    2008-01-01

    针对图书馆在对现有OPAC系统进行升级换代时所遇到的困难,通过对具有2.0特征的开源OPAC软件VuFind的介绍及基于CNMARC数据的应用实践,提出一种利用开源OPAC软件VuFind实现对图书馆现有OPAC系统升级换代的解决方案.

  4. CT 引导下穿刺定位联合单操作孔胸腔镜切除肺磨玻璃密度微小结节的临床研究%Clinic research of CT guided localization with a hook-wire system for small ground glass opacity pulmo-nary nodules united with single port video-assisted thoracoscopic resection

    Institute of Scientific and Technical Information of China (English)

    王波; 王彬; 张连斌; 初向阳

    2015-01-01

    目的:评价术中应用 CT 引导下穿刺定位后行单操作孔胸腔镜切除 CT 病灶直径<1.5 cm且胸膜无明显改变的磨玻璃样小结节的临床效果。方法2009年8月至2014年9月共15例肺磨玻璃样小结节患者,手术室内麻醉、体位固定后行术中 CT 引导下带钩钢丝针穿刺定位,随即行胸腔镜切除术。评价术中 CT 引导下穿刺定位技术的准确性、并发症、单操作孔胸腔镜手术切除率及病理结果等。结果15个磨玻璃样小结节均在术中 CT 引导下穿刺定位明确并行单操作孔胸腔镜切除术。术中 CT 定位成功率100%,平均定位时间(13.60±2.06)min,仅1例穿刺后出现少量气胸。单操作孔胸腔镜手术切除率为100%,其中肺叶切除1例,肺段切除1例,局部切除13例。术后病理诊断结果:原位腺癌9例,不典型腺瘤样增生(AAH)5例,AAH 合并原位腺癌1例。术后随访患者均存活,无复发、转移征象。结论术中麻醉下应用 CT 引导能准确将 CT 直径<1.5 cm 且胸膜无明显改变的磨玻璃样小结节行穿刺定位,并能联合单操作孔胸腔镜将其切除,准确、快捷、安全,具有很好的临床价值。%Objective To evaluate the clinical effect of CT guided localization with a hook-wire system united with single port video-assisted thoracoscopic resection (VATS)for small ground glass opacity (GGO) pulmonary nodules (CT lesion diameter <1 .5 cm and no pleural changes).Methods Fifteen patients with small GGO pulmonary nodules who underwent CT-guided transthoracic localization with a hook-wire system in operation room after anesthesia were performed with single port VATS from August 2009 to March 201 3.The accuracy of puncture location,complications,resection rate and pathological results were evaluated.Results All patients underwent CT-guided hook-wire localization and single port VATS resection.The success rate of localization was 1 00

  5. From record to data. Linked data and information seeking in the OPAC.

    Directory of Open Access Journals (Sweden)

    Antonella Iacono

    2014-01-01

    Full Text Available L’applicazione dei linked data ai dati catalografici apre nuove prospettive di sviluppo per i cataloghi elettronici delle biblioteche. Le relazioni tra dati bibliografici e di altra natura consentiranno di produrre cataloghi profondamente integrati con il resto del Web, imprimendo una svolta decisiva alla struttura dei record catalografici, alle modalità di accesso al catalogo e alle funzioni che esso potrà svolgere all’interno del più ampio spazio globale dell’informazione. In questo contributo, che si ricollega a quello pubblicato in precedenza in questa rivista, si esplora la possibilità che il nuovo record decostruito e ‘collegato’ agli altri dati sul Web sia in grado di facilitare la creazione di conoscenza nell’utilizzo del catalogo. Si analizzano così le potenzialità di applicazione dei linked data ai cataloghi per quanto riguarda le funzionalità per la ricerca, le nuove possibilità della ricerca semantica e le nuove modalità di accesso ai dati bibliografici. 

  6. Retrieving Atmospheric Dust Opacity on Mars by Imaging Spectroscopy at Large Angles

    CERN Document Server

    Douté, S; Appéré, T

    2013-01-01

    We propose a new method to retrieve the optical depth of Martian aerosols (AOD) from OMEGA and CRISM hyperspectral imagery at a reference wavelength of 1 {\\mu}m. Our method works even if the underlying surface is completely made of minerals, corresponding to a low contrast between surface and atmospheric dust, while being observed at a fixed geometry. Minimizing the effect of the surface reflectance properties on the AOD retrieval is the second principal asset of our method. The method is based on the parametrization of the radiative coupling between particles and gas determining, with local altimetry, acquisition geometry, and the meteorological situation, the absorption band depth of gaseous CO2. Because the last three factors can be predicted to some extent, we can define a new parameter {\\beta} that expresses specifically the strength of the gas-aerosols coupling while directly depending on the AOD. Combining estimations of {\\beta} and top of the atmosphere radiance values extracted from the observed spec...

  7. The opacity of spiral galaxy disks. III. Automating the synthetic field method

    NARCIS (Netherlands)

    Holwerda, BW; Gonzalez, RA; Allen, RJ; van der Kruit, PC

    2005-01-01

    Dust extinction in spiral disks can be estimated from the counts of background field galaxies, provided the deleterious effects of confusion introduced by structure in the image of the foreground spiral disk can be calibrated. Gonzalez et al. developed a method for this calibration, the Synthetic Fi

  8. Rat muscle opacity decrease due to the osmosis of a simple mixture

    Science.gov (United States)

    Oliveira, Luís; Lage, Armindo; Pais Clemente, M.; Tuchin, Valery V.

    2010-09-01

    It is known that the fibrous structure of muscle causes light scattering. This phenomenon occurs due to the refractive index discontinuities located between muscle fibers and interstitial fluid. To study the possibility of reducing light scattering inside muscle, we consider its spectral transmittance evolution during an immersion treatment with an optical clearing solution containing ethanol, glycerol, and distilled water. Our methodology consists of registering spectral transmittance of muscle samples while immersed in that solution. With the spectral data collected, we represent the transmittance evolution for some wavelengths during the treatment applied. Additionally, we study the variations that the treatment has caused on the samples regarding tissue refractive index and mass. By analyzing microscopic photographs of tissue cross section, we can also verify changes in the internal arrangement of muscle fibers caused by the immersion treatment. Due to a mathematical model that we develop, we can explain the variations observed in the studied parameters and estimate the amount of optical clearing agent that has diffused into the tissue samples during the immersion treatment. At the end of the study, we observe and explain the improvement in tissue spectral transmittance, which is approximately 65% after 20 min.

  9. Fine-Tuning Two-Particle Interferometry Effects from Opacity and Temperature Gradients in the Source

    CERN Document Server

    Tomasik, Boris; Tomasik, Boris; Heinz, Ulrich

    1998-01-01

    A comprehensive model study of Bose-Einstein correlation radii in heavy ion collisions is presented. The starting point is a longitudinally and transversally expanding fireball, represented at freeze-out by an azimuthally symmetric emission function. The freeze-out temperature is allowed to feature transverse and temporal gradients. Their effects on the correlation radii are studied. In particular, we evaluate numerically their dependence on the transverse mass of the particle pairs and check a recent suggestion, based on analytical approximations, that for certain reasonable source parameters all three correlation radii satisfy simultaneously a 1/\\sqrt{M_\\perp} scaling. We also investigate quantitatively how the correlation radii are affected if the source becomes ``opaque''. We find a strong sensitivity to opaqueness for the temporal radius parameter R_0 in the YKP parametrization. A qualitative comparison with preliminary data from 158 A GeV/c Pb+Pb collisions at CERN indicates that the source is not opaqu...

  10. Consistent dust and gas models for protoplanetary disks. I. Disk shape, dust settling, opacities, and PAHs

    NARCIS (Netherlands)

    Woitke, P.; Min, M.; Pinte, C.; Thi, W. -F; Kamp, I.; Rab, C.; Anthonioz, F.; Antonellini, S.; Baldovin-Saavedra, C.; Carmona, A.; Dominik, C.; Dionatos, O.; Greaves, J.; Güdel, M.; Ilee, J. D.; Liebhart, A.; Ménard, F.; Rigon, L.; Waters, L. B. F. M.; Aresu, G.; Meijerink, R.; Spaans, M.

    2016-01-01

    We propose a set of standard assumptions for the modelling of Class II and III protoplanetary disks, which includes detailed continuum radiative transfer, thermo-chemical modelling of gas and ice, and line radiative transfer from optical to cm wavelengths. The first paper of this series focuses on

  11. Dal record al dato. Linked data e ricerca dell’informazione nell’OPAC.

    Directory of Open Access Journals (Sweden)

    Antonella Iacono

    2013-12-01

    In this paper the author explores the possibility the new record deconstructed and connected with the other data on the Web is able to facilitate the creation of knowledge in the use of the catalogue. The author then analyzes the potential of application of linked data to the catalogue with regards to the capabilities for research, the new possibilities of semantic search and the ways to access bibliographic data.

  12. COSMIC REIONIZATION ON COMPUTERS. ULTRAVIOLET CONTINUUM SLOPES AND DUST OPACITIES IN HIGH REDSHIFT GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Khakhaleva-Li, Zimu [Department of Physics, The University of Chicago, Chicago, IL 60637 (United States); Gnedin, Nickolay Y., E-mail: zimu@uchicago.edu, E-mail: gnedin@fnal.gov [Particle Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)

    2016-04-01

    We compare the properties of stellar populations of model galaxies from the Cosmic Reionization On Computers (CROC) project with the exiting ultraviolet (UV) and IR data. Since CROC simulations do not follow cosmic dust directly, we adopt two variants of the dust-follows-metals ansatz to populate model galaxies with dust. Using the dust radiative transfer code Hyperion, we compute synthetic stellar spectra, UV continuum slopes, and IR fluxes for simulated galaxies. We find that the simulation results generally match observational measurements, but, perhaps, not in full detail. The differences seem to indicate that our adopted dust-follows-metals ansatzes are not fully sufficient. While the discrepancies with the exiting data are marginal, the future James Webb Space Telescope (JWST) data will be of much higher precision, rendering highly significant any tentative difference between theory and observations. It is, therefore, likely, that in order to fully utilize the precision of JWST observations, fully dynamical modeling of dust formation, evolution, and destruction may be required.

  13. Near-infrared observations of galaxies in Pisces-Perseus; 2, Extinction effects and disk opacity

    CERN Document Server

    Moriondo, G; Haynes, M P

    1998-01-01

    We study the correlations with inclination of H-band disk and bulge structural parameters and I-H colour profiles for a sample of 154 spiral galaxies, in order to detect possible effects due to internal extinction by dust. The selection of the sample assures that galaxies at different inclinations are not intrinsically different, so that the observed correlations represent the real behaviour of the parameter considered. All the parameters are derived from a bi-dimensional fitting of the galaxy image. We find that extinction, though small at near infrared wavelengths, is sufficient to produce observable effects. In particular the observed increase of the average disk scalelength and the reddening of the disk I-H colour at high inclinations are clear signatures of the presence of dust. The total H-band disk luminosity depends little on inclination; on the other hand significant corrections to the face-on aspect are derived for the H-band central disk brightness and the disk scalelength. The bulge parameters exh...

  14. Adopting the ritual stance: The role of opacity and context in ritual and everyday actions.

    Science.gov (United States)

    Kapitány, Rohan; Nielsen, Mark

    2015-12-01

    Rituals are a pervasive and ubiquitous aspect of human culture, but when we naïvely observe an opaque set of ritual actions, how do we come to understand its significance? To investigate this, across two experiments we manipulated the degree to which actions were ritualistic or ordinary, and whether or not they were accompanied with context. In Experiment 1, 474 adult participants were presented with videos of novel rituals (causally opaque actions) or control actions (causally transparent) performed on a set of objects accompanied with neutral-valance written context. Experiment 2 presented the same video stimuli but with negative and aversive written context. In both experiments ritualized objects were rated as physically unchanged, but more 'special' and more 'desirable' than objects subjected to control actions, with context amplifying this effect. Results are discussed with reference to the Ritual Stance and the Social-Action hypothesis. Implications for both theories are discussed, as are methodological concerns regarding the empirical investigation of ritual cognition. We argue that causally opaque ritual actions guide the behavior of naïve viewers because such actions are perceived as socially normative, rather than with reference to supernatural intervention or causation.

  15. Evaluation of Digital Optical Method To Determine Plume Opacity During Nighttime

    Science.gov (United States)

    2009-01-01

    ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 783 Published on Web 01/06/2009 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting...784 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 43, NO. 3, 2009 ds, through the plume is then described by eq 9 according to the radiative transfer...NO. 3, 2009 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 785 and the transmission model were tested during separate days because of the different testing

  16. Value-added mechanical pulps for light weight, high opacity paper

    Science.gov (United States)

    Marguerite. Sykes; John. Klungness; Freya. Tan; Said M. Abubakr

    1998-01-01

    Brightness, strength, economy, and paper machine runnability are common concerns of pacemakers who use virgin or recycled fiber furnishes. Fiber loadining, a process that precipitates calcium carbonate partially inside the fiber lumen, is a cost-effective technology that could substantially upgrade mechanical pulp furnishes. This study demonstrates the optical and...

  17. Cryoablation of a small pulmonary nodule with pure ground-glass opacity: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kun Yung; Jin, Gong Yong; Han, Young Min; Lee, Yong Chul; Jung, Myung Ja [Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Institute for Medical Sciences, Jeonju (Korea, Republic of)

    2015-06-15

    Treatments for pure ground-glass nodules (GGNs) include limited resection; however, surgery is not always possible in patients with limited pulmonary functional reserve. In such patients, cryoablation may be a suitable alternative to treat a pure GGN. Here, we report our initial experience with cryoablation of a pure GGN that remained after repeated surgical resection in a patient with multiple GGNs. A 5-mm-sized pure GGN in the left lower lobe was cryoablated successfully without recurrence at the 6-month follow-up.

  18. Sizing of sand and ash particles using their speckle pattern: influence of particle opacity

    Science.gov (United States)

    Ruiz, Sara González; van Beeck, Jeroen

    2017-08-01

    A speckle pattern is an interference pattern produced by coherent light scattered from an irregular particle. This pattern is observed in the out-of-focus plane of the particle and it can be used to obtain information about the particle size. When the particle is observed in focus, several bright spots known as glare points are observed on its surface. They correspond to the points from which the light is scattered in the direction of observation. Previous studies using the speckle pattern to obtain the size of irregular particles are based on the hypothesis that the glare points are distributed homogeneously over the whole surface of the particle. The research presented in this paper shows that in the case of opaque particles (such as ash particles), only the areas illuminated by the laser light are covered with glare points. This results in an underestimation of the particle size when characterizing opaque particles using their speckle pattern. In this paper, the speckle pattern is used to perform sizing measurements of translucent and opaque particles, and the results are compared with the ones obtained by image processing of their in-focus images.

  19. Acquisition of Chinese Quadra-Syllabic Idiomatic Expressions: Effects of Semantic Opacity and Structural Symmetry

    Science.gov (United States)

    Li, Liu; Hin Tat, Cheung

    2014-01-01

    Idiomatic expressions pose substantial learning difficulties for learners across languages and tend to be acquired later in the course of language development both in L1 and L2. A number of factors have been identified as contributing to this difficulty. However, cross-linguistic studies on figurative language acquisition are still rare. The…

  20. Updating an empirical analysis on the proton's central opacity and asymptotia

    CERN Document Server

    Fagundes, D A; Silva, P V R G

    2015-01-01

    We present an updated empirical analysis on the ratio of the elastic (integrated) to the total cross section in the c.m. energy interval from 5 GeV to 8 TeV. As in a previous work, we use a suitable analytical parametrization for that ratio (depending on only four free fit parameters) and investigate three asymptotic scenarios: either the black disk limit or scenarios above or below that limit. The dataset includes now the datum at 7 TeV, recently reported by the ATLAS Collaboration, which plays an important role in the data reductions. Our analysis favors, once more, a scenario below the black disk, providing now an asymptotic ratio consistent with the rational value 1/3, namely a gray disk limit. Upper bounds for the ratio of the diffractive (dissociative) to the inelastic cross section are also presented.

  1. Stromal opacity secondary to preservative in dilating drops - A case report and review of literature

    Institute of Scientific and Technical Information of China (English)

    Madhiusudhan; Evelyn-Tai LM; Ishak Siti-Raihan; Wan Hazabbah WH

    2014-01-01

    This patient is a64-year-old man who presented with painless progressive blurring of vision for one year.After a routine fundoscopy preceded by dilatation of both eyes with a drop of topical tropicamide, the left eye was noted to have stromal edema temporally.This was attributed to the preservative(BAC) in the medication.The stromal oedema persisted over the following weeks despite administration of a topical steroid, and was associated with deterioration in visual acuity to6/30(PH6/21).This case reminds us that clinicians should be vigilant during instillation of any preservative-containing drops, even in routine practices like dilatation.Far from being restricted to chronic use of preservative-containing drugs, toxicity withBAC can occur even upon a single application.Ideally, all eyedrops should be single-use topical drug formulations, but in the absence of this option, it is imperative that ophthalmic drug prescription be done with adequate clinical justification.

  2. Investigation of High Power, Pulsed, Neodymium-YAG Lasers for Correcting Opacities of the Human Eye.

    Science.gov (United States)

    1982-06-01

    system to breaking vitreous strands, a condition consisting of cellular strands in the vitreous humor, generally caused by disease or trauma to the eye...input beam and the output plane is at a distance -z2 from the waist of the output beam. From the ABCD law of Gaussian optics, A (-Z1 + jZR1) +B[-5

  3. Perceptual assignment of opacity to translucent surfaces: the role of image blur.

    Science.gov (United States)

    Singh, Manish; Anderson, Barton L

    2002-01-01

    In constructing the percept of transparency, the visual system must decompose the light intensity at each image location into two components one for the partially transmissivc surface, the other for the underlying surface seen through it. Theories of perceptual transparency have typically assumed that this decomposition is defined quantitatively in terms of the inverse of some physical model (typically, Metelli's 'episcotister model'). In previous work, we demonstrated that the visual system uses Michelson contrast as a critical image variable in assigning transmittance to transparent surfaces not luminance differences as predicted by Metelli's model [F Metelli, 1974 Scientific American 230(4) 90 98]. In this paper, we study the contribution of another variable in determining perceived transmittance, namely, the image blur introduced by the light-scattering properties of translucent surfaces and materials. Experiment 1 demonstrates that increasing the degree of blur in the region of transparency leads to a lowering in perceived transmittance, even if Michelson contrast remains constant in this region. Experiment 2 tests how this addition of blur affects apparent contrast in the absence of perceived transparency. The results demonstrate that, although introducing blur leads to a lowering in apparent contrast, the magnitude of this decrease is relatively small, and not sufficient to explain the decrease in perceived transmittance observed in experiment 1. The visual system thus takes the presence of blur in the region of transparency as an additional image cue in assigning transmittance to partially transmissive surfaces.

  4. Dietary carbohydrate in relation to cortical and nuclear lens opacities in the Melbourne Visual Impairment Project

    Science.gov (United States)

    PURPOSE: In vitro and in vivo animal studies suggest that dietary carbohydrates play a role in cataractogenesis. Few epidemiologic studies have been conducted to evaluate this association. The objective of this study was to examine the cross-sectional associations between total carbohydrate intake, ...

  5. Blizzard Sign as a specific endobronchial ultrasound image for ground glass opacity: A case report

    Directory of Open Access Journals (Sweden)

    Shinji Sasada, M.D. Ph.D.

    2014-01-01

    On hindsight, it was the aforementioned ultrasound pattern that helped us decide the sampling site for EBUS-GS guided TBB when fluoroscopy was equivocal. We hypothesize that this pattern is specific for GGO and we name it the Blizzard Sign.

  6. A 49-Year-Old Man with Subacute Respiratory Failure and Interstitial Lung Opacities.

    Science.gov (United States)

    Rudkovskaia, Anastasiia A; Lo, Ying-Chun; Brady, Virginia; Costa, Jose; Fares, Wassim H

    2017-08-31

    BACKGROUND Pulmonary arterial hypertension (PAH) results from proliferative vasculopathy involving all layers of the blood vessel. Similar findings may be present in pulmonary hypertension (PH) associated with microscopic tumor embolism, which are thought to be related to the phenomenon of pulmonary tumor thrombotic microangiopathy (PTTM). PTTM is associated with the activation of the coagulation system at the surface of the tumor emboli, resulting in stenosis or occlusion of the vessel. CASE REPORT A 49-year-old man with stage IV gastro-esophageal junction adenocarcinoma presented with complaints of cough and shortness of breath. These symptoms coincided with the initiation of trastuzumab with a new experimental medication with receptor tyrosine kinase blocking activity. A trans-thoracic echocardiogram demonstrated severely increased right ventricle (RV) cavity size with severely decreased RV systolic function. A computed tomography angiography was negative for pulmonary embolism but demonstrated new bilateral pulmonary infiltrates. Bronchoalveolar lavage ruled out an infectious etiology. Trans-bronchial biopsies (TBBx) showed arteriole obliteration by smooth muscle proliferation suggestive of pulmonary vasculopathy. The right heart catheterization (RHC) confirmed severe pulmonary hypertension. Unfortunately, shortly after the RHC, the patient developed pulseless electrical activity cardiac arrest and died. Autopsy results were similar to those of the TBBx, except for diffuse dissemination of tumor cells in the lymphatic channels and small pulmonary vessels, confirming a diagnosis of PTTM. CONCLUSIONS We highlight the limitations of trans-bronchial biopsies in evaluating PTTM. The final diagnosis of PTTM was not made until the autopsy was done.

  7. Consistent dust and gas models for protoplanetary disks. I. Disk shape, dust settling, opacities, and PAHs

    NARCIS (Netherlands)

    Woitke, P.; Min, M.; Pinte, C.; Thi, W. -F; Kamp, I.; Rab, C.; Anthonioz, F.; Antonellini, S.; Baldovin-Saavedra, C.; Carmona, A.; Dominik, C.; Dionatos, O.; Greaves, J.; Güdel, M.; Ilee, J. D.; Liebhart, A.; Ménard, F.; Rigon, L.; Waters, L. B. F. M.; Aresu, G.; Meijerink, R.; Spaans, M.

    2016-01-01

    We propose a set of standard assumptions for the modelling of Class II and III protoplanetary disks, which includes detailed continuum radiative transfer, thermo-chemical modelling of gas and ice, and line radiative transfer from optical to cm wavelengths. The first paper of this series focuses on t

  8. The opacity of spiral galaxy disks. VIII. Structure of the cold ISM

    NARCIS (Netherlands)

    Holwerda, B. W.; Draine, B.; Gordon, K. D.; Gonzalez, R. A.; Calzetti, D.; Thornley, M.; Buckalew, B.; Allen, Ronald J.; van der Kruit, P. C.

    2007-01-01

    The quantity of dust in a spiral disk can be estimated using the dust's typical emission or the extinction of a known source. In this paper we compare two techniques, one based on emission and one on absorption, applied to sections of 14 disk galaxies. The two measurements reflect, respectively, the

  9. Single Nodula opacity of granulomatous Pneumocystis jirovecii pneumoniain an asymptomatic lymphoma patient

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Soo; Shin, Kyung Eun; Lee, Ju Hie [Kyung Hee University Hospital, Seoul (Korea, Republic of)

    2015-04-15

    The radiologic findings of a single nodule from Pneumocystis jirovecii pneumonia (PJP) have been rarely reported. We described a case of granulomatous PJP manifesting as a solitary pulmonary nodule with a halo sign in a 69-year-old woman with diffuse large B cell lymphoma during chemotherapy. The radiologic appearance of the patient suggested an infectious lesion such as angioinvasive pulmonary aspergillosis or lymphoma involvement of the lung; however, clinical manifestations were not compatible with the diseases. The nodule was confirmed as granulomatous PJP by video-assisted thoracoscopic surgery biopsy.

  10. Learning Shape and Texture Characteristics of CT Tree-in-Bud Opacities for CAD Systems

    CERN Document Server

    Bagci, Ulas; Caban, Jesus; Suffredini, Anthony F; Palmore, Tara N; Mollura, Daniel J

    2011-01-01

    Although radiologists can employ CAD systems to characterize malignancies, pulmonary fibrosis and other chronic diseases; the design of imaging techniques to quantify infectious diseases continue to lag behind. There exists a need to create more CAD systems capable of detecting and quantifying characteristic patterns often seen in respiratory tract infections such as influenza, bacterial pneumonia, or tuborculosis. One of such patterns is Tree-in-bud (TIB) which presents \\textit{thickened} bronchial structures surrounding by clusters of \\textit{micro-nodules}. Automatic detection of TIB patterns is a challenging task because of their weak boundary, noisy appearance, and small lesion size. In this paper, we present two novel methods for automatically detecting TIB patterns: (1) a fast localization of candidate patterns using information from local scale of the images, and (2) a M\\"{o}bius invariant feature extraction method based on learned local shape and texture properties. A comparative evaluation of the pr...

  11. Opacity and Mass Emission Relationship in Forging Areas of Large Caliber Metal Parts Facilities,

    Science.gov (United States)

    1981-11-01

    SEDICK JACA COIORATIN MCC560 PINI/OWN ROAD FONT WASHINGTO. PA 190S - JOSEPH T. CLANCY ARRADCON NOVEMBER 1961 US ARMY ARMAMENT RESEARCH AND DEVELOPMENT... JACA Corporation Joseph T. Clancy, ARRADCOM DAAKIO-7 9-C-Ol 57 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. tPROJE, r I ,K AREA...WORK UNIT NUMBERS JACA Corporation 550 Pinetown Road, MMT-5794084 and . ,Mff-58040,1,,’ Fort Washington. PA 19035 II. CONTROLLING OFFICE NAME AND

  12. Lost in translation: ‘Unprovenanced objects’ and the opacity/transparency agenda of museums' policies

    Directory of Open Access Journals (Sweden)

    Cristiana Panella

    2015-07-01

    Full Text Available Attraverso l’esempio delle antiche terrecotte del Mali, questo articolo propone una riflessione epistemologica sul rapporto tra pratiche occulte che sottendono la circolazione di opere senza tracciabilità e retoriche e politiche ufficiali veicolate dai musei, sviluppando un’analisi dell’associazione kantiana tra Verità, Bellezza e Bontà presente nelle politiche del patrimonio culturale e nella circolazione delle opere d’arte. In questa prospettiva si fa riferimento alle teorie di Luhmann su fiducia e potere e di Handler sull’autenticità per mostrare come l’esclusione della vita sociale di queste terrecotte (traiettorie individuali dei mercanti d’arte, strategie d’investimento, politiche di collezione, sovrapposizione legale/illegale incrini il rapporto di fiducia che i musei vorrebbero istituire con il proprio pubblico, (riproducendo forme di diseguaglianza sociale. A partire da questa riflessione è possibile stabilire un nesso tra il valore estetico degli oggetti e il grado di opacità delle loro molteplici tappe di produzione: più il contesto locale del mercato informale e clandestino rimane vago, più il processo di omogenizzazione globale dei criteri deontologici ed estetici ufficiali risulta effettivo e solido.

  13. Determination of the far-infrared dust opacity in a prestellar core

    CERN Document Server

    Suutarinen, Aleksi; Harju, Jorma; Juvela, Mika; Andre, Philippe; Kirk, Jason M; Könyves, Vera; White, Glenn J

    2013-01-01

    (abridged) We correlated near-infrared stellar H-Ks colour excesses of background stars from NTT/SOFI with the far-IR optical depth map, tauFIR, derived from Herschel 160, 250, 350, and 500 um data. The Herschel maps were also used to construct a model for the cloud to examine the effect of temperature gradients on the estimated optical depths and dust absorption cross-sections. A linear correlation is seen between the colour H-Ks and tauFIR up to high extinctions (AV ~ 25). The correlation translates to the average extinction ratio A250um/AJ = 0.0014 +/- 0.0002, assuming a standard near-infrared extinction law and a dust emissivity index beta=2. Using an empirical NH/AJ ratio we obtain an average absorption cross-section per H nucleus of sigmaH(250um) = (1.8 +/- 0.3) * 10^(-25) cm^2 / H-atom, corresponding to a cross-section per unit mass of gas kappaG(250 um) = 0.08 +/- 0.01 cm^2 / g. The cloud model however suggests that owing to the bias caused by temperature changes along the line-of-sight these values u...

  14. Pair-production opacity at high and very-high gamma-ray energies

    CERN Document Server

    Horns, Dieter

    2013-01-01

    The propagation of high energy (HE, $E_\\gamma>100$ MeV) and very high-energy gamma-rays (VHE, $E_\\gamma>100$ GeV) in the extra-galactic photon field leads to pair-production and consequently energy- and distance-dependent attenuation of the primary intensity. The spectroscopy of an increasing number of extra-galactic objects at HE and VHE energies has demonstrated indeed the presence of such an attenuation which in turn has been used to constrain the photon density in the medium. At large optical depth ($\\tau\\gtrsim 2$) potential modifications of pair-production due to competing but rare processes (as, e.g., the presence of sub-neV axion-like particle) may be found. Indications for a pair-production anomaly have previously been found with VHE-spectra. Here, we present further indications (at the level of $3.68 \\sigma$) for a reduced optical depth at high energies from an analysis of Fermi-\\textit{LAT} data.

  15. Occupational cataracts and lens opacities in interventional cardiology. The O'CLOC study

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, Sophie; Bertrand, Alexandre; Bernier, Marie-Odile [Institut de Radioprotection et de Surete Nucleaire (IRSN), Fontenay-aux-Roses (France). Lab. of Epidemiology

    2010-07-01

    Interventional cardiologists are repeatedly and acutely exposed to scattered ionizing radiation (X-rays) during their diagnostic or therapeutic procedures. These exposures may cause damages to the eye lenses and induce early cataracts known as radiation-induced cataracts. The O'CLOC study is an ongoing epidemiological study designed to test the hypothesis of an increased risk of cataract among interventional cardiologists as compared with unexposed cardiologists. This paper summarizes a detailed article on the O'CLOC study protocol that has been published elsewhere. (orig.)

  16. Foucault’s Statement in Context: opacity of discourse versus conceptual determination

    Directory of Open Access Journals (Sweden)

    Alessandro Zir

    2015-10-01

    Full Text Available The significance of negativity as a way for conceptual determination in Hegelian dialectics is well-known. Authors such as Gilles Deleuze have underlined, on the other hand, how this notion of (dialectical negativity is incompatible with a Nietzschean perspective of interplay of forces and affirmation of difference. There is here a real distension (rather than a distinction — a fissure enabling one to think what connects and inevitably dissociates rationalistic and deconstructive philosophical perspectives on language. In this fissure it is constituted, for instance, the space of dispersion of the so-called Foucaultian statements (énoncés, the focus of his archeology. This essay addresses the context in which the Foucaultian notion of énoncé emerges. It does so by criticizing first the dialectical notion of negativity. It then considers some semiological notions used by post-structuralist authors, such as plethora of signs and floating signifier. In a third moment, examples are taken from a literary work, Vitor Ramil’s Pequod, in order to illustrate more concretely our discussion.

  17. The Gamma Ray Opacity of the Universe -- Indirect Measurements of the Extragalactic Background Light

    CERN Document Server

    Krennrich, F

    2014-01-01

    Indirect constraints on the intensity of the Extragalactic Background Light (EBL) were provided by recent studies of extragalactic sources emitting sub-TeV to multi-TeV photons. These constraints are provided thanks to the absorption of gamma rays by soft photons from the EBL (UV/optical/IR) via pair production by gamma - gamma interactions. This paper provides an overview of recent results that have led to substantially reduced uncertainties on the EBL intensity over a wide range of wavelengths from 0.1 to 15 micron.

  18. Remote Electronic Resources and the OPAC: Illustrated by the Unisa Library Experience.

    Science.gov (United States)

    Van der Merwe, Ina; Van Eeden, Welna; Hartzer, Sandra

    This paper describes the Unisa (University of South Africa) Library's experience with cataloging remote electronic resources, including electronic journals, electronic text files, online databases, digital images, Unisa campus Web sites, and mailing list discussions. The first section discusses the decision to add bibliographic references for…

  19. On the sensitivity of jet quenching to near T_C enhancement of the medium opacity

    CERN Document Server

    Renk, Thorsten

    2014-01-01

    One of the main goals of the study of high transverse momentum (P_T) observables in the context of ultrarelativisic heavy-ion collisions is the determination of properties of the produced QCD matter. In particular, the transport coefficients qhat and ehat, characterizing the interaction of the medium with a high p_T parton, are accessible via high P_T probes. However, a precision extraction of their temperature dependence from current data faces the problem that neither the spacetime geometry of the evolving matter droplet nor the link between thermodynamics and transport coefficients is unambiguously known, and various conjectured scenarios how thermodynamics and transport coefficients behave close to the phase transition exist. While often a behaviour with the energy density qhat ~ epsilon^3/4 is assumed which leads to a parametric decrease of the scaled qhat(T)/T^3 close to the critical temperature T_C, other scenarios expect instead a near T_C enhancement of jet quenching. In this work, the systematic res...

  20. The opacity of spiral galaxy disks VI. Extinction, stellar light and color

    NARCIS (Netherlands)

    Holwerda, BW; Gonzalez, RA; van der Kruit, PC; Allen, RJ

    2005-01-01

    In this paper we explore the relation between dust extinction and stellar light distribution in disks of spiral galaxies. Extinction influences our dynamical and photometric perception of disks, since it can distort our measurement of the contribution of the stellar component. To characterize the to

  1. The Opacity of Spiral Galaxy Disks III : Automating the "Synthetic Field Method"

    NARCIS (Netherlands)

    Holwerda, B. W.; González, R. A.; Allen, R. J.; Kruit, P. C. van der

    2004-01-01

    Abstract: The dust extinction in spiral disks can be estimated from the counts of background field galaxies, provided the deleterious effects of confusion introduced by structure in the image of the foreground spiral disk can be calibrated. Gonzalez et al. (1998) developed a method for this calibrat

  2. Examination of Neisseria Gonorrhoeae Opacity Protein Expression During Experimental Murine Genital Tract Infection

    Science.gov (United States)

    2005-01-01

    E., M. Virji, K. Zak and J. N. Fletcher (1987). "Immunobiology of gonococcal outer membrane protein I." Antonie Van Leeuwenhoek 53(6): 461-4. 88...pathogenic Neisseriae." Antonie Van Leeuwenhoek 53(6): 435-40. 146. Murphy, G. L., T. D. Connell, D. S. Barritt, M. Koomey and J. G. Cannon (1989

  3. The opacity of reduction: nutritional black-boxing and the meanings of nourishment

    NARCIS (Netherlands)

    Yates-Doerr, E.

    2012-01-01

    This article explores the process of consolidating technical and historically contingent ideas about nourishment into seemingly straightforward terms such as vitamins and minerals. I study the adoption of scientific principles of abstraction and reduction as a strategy of nutrition education in thre

  4. The Dust Content and Opacity of Actively Star-Forming Galaxies

    NARCIS (Netherlands)

    Calzetti, D.; Armus, L.; Bohlin, R. C.; Kinney, A. L.; Koornneef, J.; Storchi-Bergmann, T.

    1999-01-01

    Submitted to: Astrophys. J. Abstract: (Abridged) We present far-infrared (FIR) photometry at 150 micron and 205 micron of eight low-redshift starburst galaxies obtained with the ISO Photometer. Five of the eight galaxies are detected in both wavebands and these data are used, in conjunction with

  5. The dust content and opacity of actively star-forming galaxies

    NARCIS (Netherlands)

    Calzetti, D; Armus, L; Bohlin, RC; Kinney, AL; Koornneef, J; Storchi-Bergmann, T

    2000-01-01

    We present far-infrared (FIR) photometry at 150 and 205 mu m of eight low-redshift starburst galaxies obtained with the Infrared Space Observatory (ISO) ISOPHOT. Five of the eight galaxies are detected in both wave bands, and these data are used, in conjunction with IRAS archival photometry, to

  6. The opacity of reduction: nutritional black-boxing and the meanings of nourishment

    NARCIS (Netherlands)

    Yates-Doerr, E.

    2012-01-01

    This article explores the process of consolidating technical and historically contingent ideas about nourishment into seemingly straightforward terms such as vitamins and minerals. I study the adoption of scientific principles of abstraction and reduction as a strategy of nutrition education in

  7. The Extragalactic Background Light and the Gamma-ray Opacity of the Universe

    Science.gov (United States)

    Dwek, Eli; Krennrich, Frank

    2012-01-01

    The extragalactic background light (EBL) is one of the fundamental observational quantities in cosmology. All energy releases from resolved and unresolved extragalactic sources, and the light from any truly diffuse background, excluding the cosmic microwave background (CMB), contribute to its intensity and spectral energy distribution. It therefore plays a crucial role in cosmological tests for the formation and evolution of stellar objects and galaxies, and for setting limits on exotic energy releases in the universe. The EBL also plays an important role in the propagation of very high energy gamma-rays which are attenuated en route to Earth by pair producing gamma-gamma interactions with the EBL and CMB. The EBL affects the spectrum of the sources, predominantly blazars, in the approx 10 GeV to 10 TeV energy regime. Knowledge of the EBL intensity and spectrum will allow the determination of the intrinsic blazar spectrum in a crucial energy regime that can be used to test particle acceleration mechanisms and VHE gamma-ray production models. Conversely, knowledge of the intrinsic gamma-ray spectrum and the detection of blazars at increasingly higher redshifts will set strong limits on the EBL and its evolution. This paper reviews the latest developments in the determination of the EBL and its impact on the current understanding of the origin and production mechanisms of gamma-rays in blazars, and on energy releases in the universe. The review concludes with a summary and future directions in Cherenkov Telescope Array techniques and in infrared ground-based and space observatories that will greatly improve our knowledge of the EBL and the origin and production of very high energy gamma-rays.

  8. On some singularities of the correlation functions that determine neutrino opacities

    CERN Document Server

    Sawyer, R F

    1999-01-01

    Certain perturbation graphs in the calculation of the effects of the medium on neutrino scattering in supernova matter have a nonintegrable singularity in a physical region. A number of papers have addressed the apparent pathology through an ansatz that invokes higher order (rescattering) effects. Taking the Gamow-Teller terms as an example, we display an expression for the spin-spin correlation function that determines the cross-sections. It is clear from the form that there are no pathologies in the order by order perturbation expansion. Explicit formulae are given for a simple case, leading to an answer that is very different from one given by other authors.

  9. The Dust Content and Opacity of Actively Star-Forming Galaxies

    Science.gov (United States)

    Calzetti, Daniela; Armus, Lee; Bohlin, Ralph C.; Kinney, Anne L.; Koornneef, Jan; Storchi-Bergmann, Thaisa

    2000-01-01

    We present far-infrared (FIR) photometry at 150 and 205 micron(s) of eight low-redshift starburst galaxies obtained with the Infrared Space Observatory (ISO) ISOPHOT. Five of the eight galaxies are detected in both wave bands, and these data are used, in conjunction with IRAS archival photometry, to model the dust emission at lambda approximately greater than 40 microns. The FIR spectral energy distributions (SEDs) are best fitted by a combination of two modified Planck functions, with T approx. 40 - 55 K (warm dust) and T approx. 20-23 K (cool dust) and with a dust emissivity index epsilon = 2. The cool dust can be a major contributor to the FIR emission of starburst galaxies, representing up to 60% of the total flux. This component is heated not only by the general interstellar radiation field, but also by the starburst itself. The cool dust mass is up to approx. 150 times larger than the warm dust mass, bringing the gas-to-dust ratios of the starbursts in our sample close to Milky Way values, once resealed for the appropriate metallicity. The ratio between the total dust FIR emission in the range 1-1000 microns and the IRAS FIR emission in the range 40 - 120 microns is approx. 1.75, with small variations from galaxy to galaxy. This ratio is about 40% larger than previously inferred from data at millimeter wavelengths. Although the galaxies in our sample are generally classified as "UV bright," for four of them the UV energy emerging shortward of 0.2 microns is less than 15% of the FIR energy. On average, about 30% of the bolometric flux is coming out in the UV-to-near-IR wavelength range; the rest is emitted in the FIR. Energy balance calculations show that the FIR emission predicted by the dust reddening of the UV-to-near-IR stellar emission is within a factor of approx. 2 of the observed value in individual galaxies and within 20% when averaged over a large sample. If our sample of local starbursts is representative of high-redshift (z approx. greater than 1), UV - bright star-forming galaxies, these galaxies' FIR emission will be generally undetected in submillimeter surveys, unless: (1) their bolometric luminosity is comparable to or larger than that of ultraluminous FIR galaxies and (2) their FIR SED contains a cool dust component.

  10. Lightweight, high-opacity paper : process costs and energy use reduction

    Science.gov (United States)

    John H. Klungness; Fabienne. Pianta; Mathew L. Stroika; Marguerite. Sykes; Freya. Tan; Said. AbuBakr

    1999-01-01

    Fiber loading is an environmentally friendly, energy efficient, and economical method for depositing precipitated calcium carbonate (PCC) partly within pulp fibers. Fiber loading can easily be done within the existing pulp processing system. This paper is a review of the process development from bench-scale to industrial-scale demonstrations, with additional...

  11. Conversion of Wade-Giles to Pinyin: An Estimation of Efficiency Improvement in Retrieval for Item-Specific OPAC Searches.

    Science.gov (United States)

    Arsenault, Clement

    1998-01-01

    Discusses the adoption of the pinyin Romanization standard over Wade-Giles and considers the impact on retrieval in online library catalogs. Describes an investigation that tested three factors that could influence retrieval efficiency: the number of usable syllables, the average number of letters per syllable, and users' familiarity with the…

  12. Using Orthogonal Images to Infer Spatial Variations in Opacity of Remaining Ablator and Fuel Mass in Imploding Capsules

    Science.gov (United States)

    Benedetti, Laura Robin; Bradley, David; Glenn, Steven; Izumi, Nobuhiko; Khan, Shahab; Kyrala, George; Ma, Tammy; Pak, Art; Smalyuk, Vladimir; Tommasini, Riccardo; Town, Richard

    2012-10-01

    Experiments at the National Ignition Facility attempt to achieve laser-driven inertial confinement fusion by imploding a capsule of DT fuel. In order to achieve sufficient density and temperature to drive nuclear fusion, the imploding capsule must be both highly convergent and highly symmetric. X-ray self-emission from imploding capsules is imaged for size and symmetry along two orthogonal axes by time-integrated (image plates) and time-resolved (framing cameras) diagnostics. Differences in emission along these axes indicate either an anisotropic hot core or anisotropy in total optical depth of the remaining ablator and fuel mass. We compare integrated emission intensity along a common-line-of-sight to further remove the ambiguity between anisotropy of emission and absorption. While we find good correlation for some recent NIF implosions (indicating isotropic or optically thin remaining mass), we find significant variations for others, suggesting an observable anisotropy in the thickness or density of the remaining mass. These results may help explain observations of asymmetric neutron yield. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, LLNL-ABS-564186.

  13. EVALUATION OF A LENS OPACITIES CLASSIFICATION SYSTEM II (LOCS II) IN THE SURVEY POPULATION-BASED SAMPLE

    Institute of Scientific and Technical Information of China (English)

    1991-01-01

    In the field work of populationbased research, 3 groups of eyes were graded by 2 observers in LOCS Ⅱ. The reproducibility of LOCS Ⅱwas evaluated by agreements(85%-100%) and k values(0.661-1) obtained in our study. The satisfying results show that LOCS Ⅱis not only easy to be learned and to be applied consistently by different observers, but also good reproducibility in the field work. The longitudinal cataract study is going to be performed in our plan.

  14. Integration of Ebrary Electronic Books to OPAC System%Ebrary电子图书与OPAC系统整合

    Institute of Scientific and Technical Information of China (English)

    张秋萍; 袁昊

    2008-01-01

    将Ebrary英文电子图书整合到OPAC系统,用户通过书目查询能全面了解图书的馆藏信息并在线浏览电子图书全文,本文阐述了电子图书与OPAC系统整合的总体思路及操作过程,并针对存在的问题提出改进方法.

  15. A Direct Precision Measurement of the Intergalactic Lyman-alpha Opacity at 2

    CERN Document Server

    Faucher-Giguere, C -A; Lidz, A; Hernquist, L; Zaldarriaga, M

    2007-01-01

    We directly measure the evolution of the intergalactic Lyman-alpha effective optical depth, tau_eff, over the redshift range 2 is <1% at z=2, 4% at z=3, and 12% at z=4. Previous measurements of tau_eff at 3

  16. Monitoring temporal opacity fluctuations of large structures with muon tomography : a calibration experiment using a water tower tank

    CERN Document Server

    Jourde, Kevin; Marteau, Jacques; d'Ars, Jean de Bremond; Gardien, Serge; Girerd, Claude; Ianigro, Jean-Christophe

    2015-01-01

    The idea of using secondary cosmic muons to scan the internal structure of a given body has known significant developments since the first archaeological application by Alvarez and collaborators on the Gizah pyramids. Recent applications cover the fields of volcanology, hydrology, civil engineering, mining, archaeology etc. Muon radiography features are essentially identical to those of medical X-ray imaging techniques. It is a contrast densitometry method using the screening effect of the body under study on the natural flux of cosmic muons. This technique is non-invasive and complements the standard geophysical techniques, e.g. electrical tomography or gravimetry. It may be applied to a large variety of geological targets, among which the domes of active volcanoes. In this context muon tomography presents the noticeable advantage to perform measurements of large volumes, with a large aperture, from a distant point, far from the potentially dangerous zones. The same conclusions apply regarding the monitoring...

  17. Medicinal management of corneal opacity in free ranging rhesus macaques (Macaca mulatta of Shivalik hills in Western Himalayas, Northern India

    Directory of Open Access Journals (Sweden)

    V. Kumar

    2015-05-01

    Full Text Available Corneal opacification was diagnosed in 17 free ranging rhesus macaques during detailed ophthalmic examination as a part of clinical health examination, at the monkey rescue sterilization centre in Hamirpur Himachal Pradesh, India. The cornea was completely opaque permitting only a little vision with respect to the affected eye. Medical management with topical ciprofloxacin and prednisolone along with ketoprofen and vitamin A was instituted. The corneal lesions subsided completely within one week following treatment. The treatment protocol successfully eliminated the discomfort and intraocular lesions with no serious subsequent irritation due to the treatment in these animals.

  18. 维基在OPAC的应用与影响%Wiki's Influences and Its Application in OPAC in Libraries

    Institute of Scientific and Technical Information of China (English)

    杨亚晶; 张立肖

    2007-01-01

    文章结合OCLC的Wiki WorldCat(WikiD)项目,重点介绍了维基在OPAC中的应用.指出维基化OPAC将会丰富书目数据库的内容,完善OPAC的功能;为图书馆资源建设提供新思路;有可能提升图书馆的服务水平.

  19. Influence of yttrium iron garnet thickness and heater opacity on the nonlocal transport of electrically and thermally excited magnons

    NARCIS (Netherlands)

    Shan, Juan; Cornelissen, Ludo J.; Vlietstra, Nynke; Ben Youssef, Jamal; Kuschel, Timo; Duine, Rembert; Van Wees, Bart J.

    2016-01-01

    We studied the nonlocal transport behavior of both electrically and thermally excited magnons in yttrium iron garnet (YIG) as a function of its thickness. For electrically injected magnons, the nonlocal signals decrease monotonically as the YIG thickness increases. For the nonlocal behavior of the t

  20. Dust models post-Planck: constraining the far-infrared opacity of dust in the diffuse interstellar medium

    CERN Document Server

    Fanciullo, Lapo; Aniano, Gonzalo; Jones, Anthony P; Ysard, Nathalie; Miville-Deschênes, Marc-Antoine; Boulanger, François; Köhler, M

    2015-01-01

    We compare the performance of several dust models in reproducing the dust spectral energy distribution (SED) per unit extinction in the diffuse interstellar medium (ISM). We use our results to constrain the variability of the optical properties of big grains in the diffuse ISM, as published by the Planck collaboration. We use two different techniques to compare the predictions of dust models to data from the Planck HFI, IRAS and SDSS surveys. First, we fit the far-infrared emission spectrum to recover the dust extinction and the intensity of the interstellar radiation field (ISRF). Second, we infer the ISRF intensity from the total power emitted by dust per unit extinction, and then predict the emission spectrum. In both cases, we test the ability of the models to reproduce dust emission and extinction at the same time. We identify two issues. Not all models can reproduce the average dust emission per unit extinction: there are differences of up to a factor $\\sim2$ between models, and the best accord between ...

  1. Folksonomy在高校图书馆OPAC中的应用%The Application of Folksonomy in OPAC of University Library

    Institute of Scientific and Technical Information of China (English)

    崔莎; 鞠春杨

    2010-01-01

    在对Folksonomy进行理论研究的基础上,通过调研Folksonomy在国内外的应用实例,总结了其在高校图书馆OPAC应用的重要意义,阐述了其应用的局限性,并提出具有理论基础和一定可行性的解决建议.

  2. The opacity of Spiral Disks IV : Radial Extinction Profiles from Counts of Distant Galaxies seen through Foreground Disks

    NARCIS (Netherlands)

    Holwerda, B. W.; González, R. A.; Allen, R. J.; Kruit, P.C. van der

    2004-01-01

    Dust extinction can be determined from the number of distant field galaxies seen through a spiral disk. To calibrate this number for the crowding and confusion introduced by the foreground image, Gonzalez et al. (1998) and Holwerda et al. (2005a) developed the ``Synthetic Field Method'' (SFM), which

  3. The opacity of spiral galaxy disks. IV. Radial extinction profiles from counts of distant galaxies seen through foreground disks

    NARCIS (Netherlands)

    Holwerda, BW; Gonzalez, RA; Allen, RJ; van der Kruit, PC

    2005-01-01

    Dust extinction can be determined from the number of distant field galaxies seen through a spiral disk. To calibrate this number for the crowding and confusion introduced by the foreground image, Gonzalez et al. and Holwerda et al. developed the Synthetic Field Method (SFM), which analyzes synthetic

  4. Evaluation of Neisseria Gonorrhoeae Opacity (Opa) Protein Loops as Targets for Passive Vaccination and Investigation of the Role of Opa Proteins During Infection of a Female Host

    Science.gov (United States)

    2009-08-24

    lymphocyte activation (23, 135), and hindered by degradation of IgA1 by a secreted IgA protease (138, 139), generation of blocking antibodies against the... fluoroquinolones from recommended treatments (1), and underscores the importance of identifying new preventive measures against gonorrhea. The...References 1. 2007. Update to CDC’s sexually transmitted diseases treatment guidelines, 2006: fluoroquinolones no longer recommended for treatment of

  5. 40 CFR 62.14820 - How must I monitor opacity for air curtain incinerators that burn 100 percent wood wastes, clean...

    Science.gov (United States)

    2010-07-01

    ... wood wastes, clean lumber, and/or yard waste? (a) Use Method 9 of 40 CFR part 60, Appendix A to... curtain incinerators that burn 100 percent wood wastes, clean lumber, and/or yard waste? 62.14820 Section... Before November 30, 1999 Air Curtain Incinerators That Burn 100 Percent Wood Wastes, Clean Lumber...

  6. La opacidad de los acuerdos generales de bienes y servicios en España Opacity of general agreements on goods and services in Spain

    Directory of Open Access Journals (Sweden)

    Román Andrés Umaña Peña

    2006-06-01

    Full Text Available Objetivo: Explorar la intensidad del debate parlamentario sobre el Acuerdo General de Comercio de Servicios (AGCS asumido por España ante la Organización Mundial del Comercio (OMC, y compararla con la del Acuerdo General de Bienes (GATT. Métodos: Búsqueda sistemática y análisis del contenido de todas las iniciativas parlamentarias sobre AGCS y GATT realizadas entre 1979 y 2004 en el Congreso de los Diputados y el Senado. Se calculó la frecuencia y porcentaje de iniciativas parlamentarias de ambos temas, resultado de su tramitación y tipo de iniciativa. Resultados: Se presentaron 185 iniciativas parlamentarias sobre los acuerdos multilaterales de bienes y servicios, de las que 120 se referían al GATT, 8 al AGCS y 57 a ambos acuerdos. La mayoría de las iniciativas no fueron discutidas (GATT, 71%; GATS, 55,4% o estuvieron sujetas a un debate político en el que apenas se dieron intervenciones por parte de los grupos parlamentarios. Conclusiones: A pesar de las implicaciones del acuerdo multilateral de servicios para la política sanitaria española, éste se ha asumido con escaso debate parlamentario previo, incluso menos que en el caso de su homólogo sobre bienes. Se requiere en este tema una intensificación de la función de control al gobierno.Objective: To explore the intensity of the debate in the Spanish Parliament on the General Agreement on Trade in Services (GATS developed by Spain and the World Trade Organization, and to compare it with the debate on the General Agreement on Tariffs and Trade (GATT. Methods: A systematic search and content analysis were performed of all parliamentary initiatives on GATS and GATT undertaken from 1979 to 2004 in the Spanish Parliament and Senate. The frequency and percentages of initiatives on both issues were calculated, and the final result and kinds of initiative were analyzed. Results: A total of 185 initiatives were presented in the Spanish Parliament on these agreements, of which 120 were on GATT, 8 were on GATS and 57 were on both agreements. Most of these initiatives were not discussed in parliament (GATT, 71%; GATS, 55.4% or were the subject of political debate with low participation among parliamentary groups. Conclusions: Despite the implications of the GATS for Spanish health policy, the agreement was developed with little prior political debate, which was even less intense than that on GATT. The parliamentary function of controlling the government should be reaffirmed in Spain.

  7. The Integration of Electronic Books and OPAC System in Academic Libraries%高校图书馆电子图书与OPAC系统整合初探

    Institute of Scientific and Technical Information of China (English)

    巩林立

    2005-01-01

    将高校图书馆电子图书与OPAC书目查询系统整合在一起,为读者开辟了更加快捷地获取文献全文的渠道.本文结合实际,就电子图书与图书馆OPAC系统的整合谈一些看法.

  8. Progress of the LANL Low Temperature/Low Frequency Air Opacity Project - Optical Theory for HET-project: an update, April 2015

    Energy Technology Data Exchange (ETDEWEB)

    Timmermans, Eddy Marcel Elvire [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nisoli, Cristiano [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mozyrsky, Dima [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hakel, Peter [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sherrill, Manolo [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Duffy, Leanne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-05-20

    Light radiated from a hot, opaque thermal emitter originates mostly from near the surface at which the object becomes opaque (the surface of last scattering). To be specific, we define the “optical surface” as the surface at which the optical depth, as observed from a detector, takes on the value of 1. The optical depth along a line of sight depends on the wavelength dependent. Accumulating light in different spectral bands, spectral detector then records light from different surfaces, a structure that we can picture somewhat like the layers of an onion. The theoretical framework that predicts the emitted spectral signal is radioactive transfer.

  9. A Comparative Study of Next Generation Open Source OPAC System%新一代开源OPAC系统比较研究

    Institute of Scientific and Technical Information of China (English)

    张平杉; 章伟煊

    2011-01-01

    通过对图书馆主要使用的7种开源OPAC系统在基本技术信息、检索功能、检索结果的显示和输出、Web2.0功能等方面进行调查和对比分析,对其存在的问题进行探讨,为国内图书馆选用开源OPAC系统提供指导及借鉴.

  10. Ironía o, la Teoría Dans le Boudoir Notas sobre el libro 'Irony or, the Self-Critical Opacity of Postmodern Architecture'

    Directory of Open Access Journals (Sweden)

    Fernando Quesada

    2015-05-01

    Full Text Available ResumenPara la portada de este libro el autor ha elegido un dibujo muy atinado. Se trata de una ilustración de Saul Steinberg, arquitecto de formación e ilustrador de ofi cio, en el que se ve un cubo trazado en perspectiva axonométrica ligeramente imperfecta que muestra unas líneas gruesas y una sombra proyectada. El cubo sueña o imagina a su otro, un cubo perfecto, en perspectiva impecable y con sus vértices numerados con letras. La ironía desprendida de este dibujo sería equivalente a la que el posmodernismo practicó sobre el proyecto moderno, visto por unos epígonos altamente críticos, desconfi ados y descreídos comopoco más que una ilusión o un ideal soñado, frente a una realidad llena de fi suras, imperfecta y difícilmente sujeta a proyecto alguno, moderno o no. La ironía no pertenece propiamente ni al cubo ideal y perfecto ni al oblongo e imperfecto, pero necesita al primero para poder ser ejercida o practicada, ya que por defi nición se practica con respecto a algo externo a sí mismo, y aún más necesita al segundo porque es el único agente activo irónico posible, o como poco el único legitimado para el ejercicio de la ironía. Este libro propone una relectura del posmodernismo arquitectónico como una era histórica irónica, de lo que se desprende una interpretación de la ironía arquitectónica como categoría epocal de algún modo atrapada por la interpretación que entonces se hizo del proyecto moderno como cubo impecable. Sin embargo, ¿quién afi rmaría hoy día, si su interés no es defender una categoría epocal determinada o un proyecto intelectual, que la arquitectura moderna fue un cubo perfecto? AbstractFor the cover of this book the author has chosen a very wise drawing. It is an illustration by Saul Steinberg, a trained architect and illustrator by trade, in which one sees a cube drawn in slightly imperfect axonometric perspective showing thick lines and shadows. The cube dreams or imagines its other, a perfect cube in flawless perspective with its vertices numbered and lettered. The detached irony of this drawing would be equivalent to that of postmodernism practiced on the modern project as seen by some of their followers: highly critical, suspicious and unbelieving subjects who envisioned modernism as little more than an illusion or an ideal dream, in contradistinction to a fi ssured, imperfect reality which is hardly the subject of any project, be it modern or not. Irony does not properly belong either to the ideal and perfect cube, or to the oblong and imperfect one. It needs the former to be exercised, since by definition it is practiced with respectto something outside of itself, and it needs the latter even more, because it is the only possible active ironic agent, or at least, the only entitled to the exercise of irony. This book proposes a reinterpretation of architectural postmodernism as an ironic historical era, of what follows an interpretation of architectural irony as an epochal category somehow trapped by the interpretation which sanctioned the modern project as an impeccable hub. But, who would claim today –if the interest is not to defend a particular category or intellectual project-, that modern architecture was a perfect cube?

  11. Pre-clinical Measures of Eye Damage (Lens Opacity), Case-control Study of Tuberculosis, and Indicators of Indoor Air Pollution from Biomass Smoke

    OpenAIRE

    Pokhrel, Amod Kumar

    2010-01-01

    This dissertation examines the level of two major pollutants in the kitchens from biomass, kerosene and liquefied petroleum gas (LPG) stoves, and two health problems associated with use of biomass and kerosene compared with LPG stove in Nepal. Its chapter a) characterizes the exposure levels of two pollutants-fine particles (PM2.5) and naphthalene from three cookstoves, b) validate exposure questionnaire used in two epidemiological studies with the gold standard, c) showcase method to estimat...

  12. 开源OPAC软件VuFind及其分面浏览机制%Faceted Browsing Mechanism of VuFind - One OSS OPAC

    Institute of Scientific and Technical Information of China (English)

    李勇文

    2012-01-01

    Web2.0技术为OPAC带来了新的挑战,下一代集成在线目录既要适应新技术的变化,也要适应用户信息检索行为的变化;开源软件风起云涌,国外已经出现用户接受度高的众多开源OPAC软件,VuFind便是其中的典型代表之一.文章在分析分面浏览功能基础上,剖析了VuFind的分面浏览实现机制.

  13. 构建OPAC输出性英语语言应用能力培养模式%On the OPAC Mode of English Output Performance

    Institute of Scientific and Technical Information of China (English)

    彭秀林

    2016-01-01

    The teaching reform on the development of English output performance is carried out in our Business English Specialty. The construction of the mode of English output performance is a necessity to help students of Business English Specialty with their adaptability and competitiveness in job market, and is a bold attempt to apply the output hypothesis to the teaching of the lingual courses of Business English Specialty. The mode combines the output English performance, language practice in the workplaces, language activities in and out of class, and the participation of English contests. The effects of the mode are tested.%我校商务英语专业围绕“‘输出性’英语语言应用能力培养”开展了多方面的改革实践。构建输出性英语语言应用能力培养模式既是增强高职院校商务英语专业学生职场适应能力,提升学生的职业竞争力的必然要求,也是输出假设理论在高职院校商务英语专业各门语言课程中综合应用的大胆尝试。该模式以语言“输出(Output)”为指向,注重语言“实践训练(Practice)”,开展丰富多彩的课内外“语言活动(Activities)”,组织学生参加校内外“英语竞赛(Contests)”,提升学生输出性英语语言应用能力。

  14. An Empirical Determination of the Intergalactic Background Light from UV to FIR Wavelengths Using FIR Deep Galaxy Surveys and the Gamma-ray Opacity of the Universe

    OpenAIRE

    Stecker, FW; Scully, ST; Malkan, MA

    2016-01-01

    We have previously calculated the intergalactic background light (IBL) as a function of redshift in the far ultraviolet to near infrared range, based purely on data from deep galaxy surveys. Here we utilize similar methods to determine the mid- and far infrared IBL out to a wavelength of 850 microns. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. By also including...

  15. OPAC vs搜索引擎——从上海交大看我国高校师生的信息获取行为%OPAC sv search engine——Information acquirement behavior of Chinese college students and teachers by taking Shanghai Jiaotong University as an example

    Institute of Scientific and Technical Information of China (English)

    王绍平; 汤莉华

    2008-01-01

    以上海交通大学为对象,通过网上问卷调查,从查找资料的目的、检索行为习惯与信息源评价三个方面,了解与剖析网络环境下我国高校师生的信息获取行为,并就凋查中发现的问题,对改进我国高校图书馆资源建设与图书馆目录工作提出了建议.

  16. Relation between 183 GHz Water Vapor Line and Water Continuum Absorption Measured with FTS

    Science.gov (United States)

    Matsushita, S.; Matsuo, H.

    ve carried out Fourier Transform Spectrometer (FTS) measurements of the millimeter and submillimeter-wave (100-1500 GHz or 3 mm - 200 micron) atmospheric opacity at Pampa la Bola, 4800 m above sea level in northern Chile on September 1997 and June 1998. Correlations between 220 GHz opacities and those of the center of submillimeter-wave windows were obtained using the entire data set, and good correlations were obtained except for the periods affected by the liquid water opacity component. We succeeded to separate the total opacity to water vapor and liquid water opacity components. The separated water vapor opacity component shows good correlation with the 183 GHz pure water vapor line opacity, which is also covered in the measured spectra, but the liquid water opacity component shows no correlation. Since the submillimeter-wave opacity is merely affected by the liquid water component, it may be better to use the submillimeter-wave opacity for the phase correction.

  17. The Influence of Basis Weight on Opacity and Light Absorption Coefficient of Paper%定量对纸张不透明度及特定光吸收系数的影响

    Institute of Scientific and Technical Information of China (English)

    于冬梅; 陈克复; 赵传山; 杨仁党; 洪义梅

    2006-01-01

    特定光吸收系数比白度更能准确地反映纸浆中的发色团浓度,成为非脱木素漂白动力学研究的主要参数之一,而纸张定量是影响光学系数的一个重要因素.本文根据Kubelka-Munk理论探讨了定量对不透明度及特定波长的光吸收系数的影响.不透明度随定量的变化采用Boltzmann函数进行非线性回归,达到99.98%的相关性,说明定量对不透明度起决定性作用而光散射系数的影响可忽略不计.而定量对特定光吸收系数的影响比较复杂,457nm处的光吸收系数随定量的变化可分为3个阶段:平缓段、上升段及持续下降段.平缓段内纸样的不透明度<95%,对应的纸张定量≤60 g/m2,光吸收系数变化的平缓段内适宜进行漂白动力学研究.

  18. 图书馆OPAC的FRBR实践及相关思考——来自RDA标准的启示%FRBR Practices of Library OPAC and Related Issues:Inspirations from RDA Rules

    Institute of Scientific and Technical Information of China (English)

    高红; 靖翠峥

    2011-01-01

    (RDA)是数字环境下资源著录与检索的新标准.首先介绍图书馆OPAC进行FRBR组织的必要性、实现途径与面临的问题,分析RDA在强调书目关系、充实规范控制以及解决多载体文献揭示等方面的主要变化,进而从提高用户检索准确性、增强OPAC导航能力以及确立元数据的组织模型、结构、关系方面,探索RDA对图书馆OPAC可能产生的积极影响和变革.

  19. MRO/CRISM Retrieval of Surface Lambert Albedos for Multispectral Mapping of Mars with DISORT-based Rad. Transfer Modeling: Phase 1 - Using Historical Climatology for Temperatures, Aerosol Opacities, & Atmo. Pressures

    CERN Document Server

    McGuire, P C; Smith, M D; Arvidson, R E; Murchie, S L; Clancy, R T; Roush, T L; Cull, S C; Lichtenberg, K A; Wiseman, S M; Green, R O; Martin, T Z; Milliken, R E; Cavender, P J; Humm, D C; Seelos, F P; Seelos, K D; Taylor, H W; Ehlmann, B L; Mustard, J F; Pelkey, S M; Titus, T N; Hash, C D; Malaret, E R

    2009-01-01

    We discuss the DISORT-based radiative transfer pipeline ('CRISM_LambertAlb') for atmospheric and thermal correction of MRO/CRISM data acquired in multispectral mapping mode (~200 m/pixel, 72 spectral channels). Currently, in this phase-one version of the system, we use aerosol optical depths, surface temperatures, and lower-atmospheric temperatures, all from climatology derived from Mars Global Surveyor Thermal Emission Spectrometer (MGS-TES) data, and surface altimetry derived from MGS Mars Orbiter Laser Altimeter (MOLA). The DISORT-based model takes as input the dust and ice aerosol optical depths (scaled to the CRISM wavelength range), the surface pressures (computed from MOLA altimetry, MGS-TES lower-atmospheric thermometry, and Viking-based pressure climatology), the surface temperatures, the reconstructed instrumental photometric angles, and the measured I/F spectrum, and then outputs a Lambertian albedo spectrum. The Lambertian albedo spectrum is valuable geologically since it allows the mineralogical ...

  20. WEB页面分析技术和Mashup技术在图书馆OPAC中的应用%The Applications of WEB Analytics Technology and Mashup Technology in the Library OPAC

    Institute of Scientific and Technical Information of China (English)

    党兴华; 王洪燕

    2008-01-01

    OPAC使图书馆读者可以万维网实现对本地图书资源的查找和借阅.但是单纯依靠本地数据信息只能提供图书内容、典藏信息、借阅状态等信息,并不能及时提供诸如书评、图书封面等相关及时信息.利用WEB页面分析技术和Mashup技术可以将互联网相关信息整合到OPAC中,使读者可以客观形象地得到更全面的信息.