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Sample records for absorption feature indices

  1. Integrated Spectral Energy Distributions and Absorption Feature Indices of Single Stellar Populations

    OpenAIRE

    Zhang, Fenghui; Han, Zhanwen; Li, Lifang; Hurley, Jarrod R.

    2004-01-01

    Using evolutionary population synthesis, we present integrated spectral energy distributions and absorption-line indices defined by the Lick Observatory image dissector scanner (referred to as Lick/IDS) system, for an extensive set of instantaneous burst single stellar populations (SSPs). The ages of the SSPs are in the range 1-19 Gyr and the metallicities [Fe/H] are in the range -2.3 - 0.2. Our models use the rapid single stellar evolution algorithm of Hurley, Pols and Tout for the stellar e...

  2. Frequency-chirped readout of spatial-spectral absorption features

    International Nuclear Information System (INIS)

    Chang, Tiejun; Mohan, R. Krishna; Harris, Todd L.; Merkel, Kristian D.; Tian Mingzhen; Babbitt, Wm. Randall

    2004-01-01

    This paper examines the physical mechanisms of reading out spatial-spectral absorption features in an inhomogeneously broadened medium using linear frequency-chirped electric fields. A Maxwell-Bloch model using numerical calculation for angled beams with arbitrary phase modulation is used to simulate the chirped field readout process. The simulation results indicate that any spatial-spectral absorption feature can be read out with a chirped field with the appropriate bandwidth, duration, and intensity. Mapping spectral absorption features into temporal intensity modulations depends on the chirp rate of the field. However, when probing a spatial-spectral grating with a chirped field, a beat signal representing the grating period can be created by interfering the emitted photon echo chirped field with a reference chirped field, regardless of the chirp rate. Comparisons are made between collinear and angled readout configurations. Readout signal strength and spurious signal distortions are investigated as functions of the grating strength and the Rabi frequency of the readout pulse. Using a collinear readout geometry, distortions from optical nutation on the transmitted field and higher-order harmonics are observed, both of which are avoided in an angled beam geometry

  3. Cuticular features as indicators of environmental pollution

    Science.gov (United States)

    G. K. Sharma

    1976-01-01

    Several leaf cuticular features such as stomatal frequency, stomatal size, trichome length, type, and frequency, and subsidiary cell complex respond to environmental pollution in different ways and hence can be used as indicators of environmental pollution in an area. Several modifications in cuticular features under polluted environments seem to indicate ecotypic or...

  4. Spectroscopy of the 4.6 - 4.7 micron interstellar absorption features

    International Nuclear Information System (INIS)

    Geballe, T.R.

    1984-01-01

    Perhaps the most successful application of spectroscopy to the study of interstellar solid state infrared absorption features has been in the case of the previously unidentified feature near 4.6 μm first seen in absorption toward the protostar W33A. Whereas the original spectrum of this object, obtained at a resolving power of 70, revealed only a single deep absorption feature, a later spectrum, using a single channel grating spectrometer at ten times the resolving power, indicates that it is made up of three separate components. The central narrow absorption feature at 2140 cm -1 (4.67 μm) coincides in wavelength precisely with that of solid CO. It and its unresolved shoulder at just lower frequency have now been seen quite commonly in absorption toward other protostars. The broad absorption seen in W33A at 2165 cm -1 (4.62 μm) is apparently much less common. (author)

  5. Cerebral oligodendroglioma: MR features indicating anaplastic changes

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Choong Gon; Chang, Kee Hyun; Han, Moon Hee; Chi, Je Geun [Seoul National Univ., Seoul (Korea, Republic of); Yoon, Hyun Ki [Ulsan Univ., Seoul (Korea, Republic of)

    1995-10-15

    The purpose of this study is to find helpful MR findings for predicting anaplastic oligodendrogliomas. Retrospective analysis of 46 MR images and 37 CT scans was performed for 46 patients with pathologically-proven cerebral oligodendrogliomas. A neuropathologist graded the tumors as one of low-grade (n = 16), intermediate-grade (n = 12), or anaplastic oligodendroglioma (n 18). MR imaging features were retrospectively analysed with respect to histologic grading of the tumors. Contrast enhancement was observed always in anaplastic group (17/17), in a portion of intermediate-grade group (4/10) but not in low-grade group (0/4). Peritumoral edema was observed infrequently in anaplastic group (4/18) or intermediate-grade group (1/12). Cystic changes (25/46) or calcifications on CT Scans (14/37) were not related with histologic grading. Grossly identifiable hemorrhage was rare in this series (2/46). Among the various imaging features, only tumor enhancement and peritumoral edema were statistically significant for trend test ({rho} < 0.05). When considering the diagnosis of oligodendrogliomas, the presence of contrast enhancement or peritumoral edema is a helpful features suggesting anaplastic oligodendrogliomas.

  6. Wavelength calibration of imaging spectrometer using atmospheric absorption features

    Science.gov (United States)

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

    2012-11-01

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

  7. A Review of Some Features of Radiowave Absorption | Iheonu ...

    African Journals Online (AJOL)

    . The analysis deals with absorption of radiowaves through the ionosphere using the absorption method – A3 (CW Field Strength) adopting data from the Swiss PTT MNIFTZ 4.1 computer predictions for shortwave transmission. The study gives ...

  8. On the nature of absorption features toward nearby stars

    Science.gov (United States)

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

    2016-06-01

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

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

    Science.gov (United States)

    Kokaly, Raymond F.; Skidmore, Andrew K

    2015-01-01

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

  10. Absorption optical density as a diagnostic tool for indicating the ...

    African Journals Online (AJOL)

    Nanotechnology has recently emerged as a promising approach for treatment and diagnosis of a variety of diseases. The aim of this study was to evaluate the blood absorption spectra to assess bioaccumulation and toxic effects of 100 μl of 10 and 50 nm gold nanoparticles (GNPs) upon intraperitoneal administration in rats ...

  11. Atmospheric-water absorption features near 2.2 micrometers and their importance in high spectral resolution remote sensing

    Science.gov (United States)

    Kruse, F. A.; Clark, R. N.

    1986-01-01

    Selective absorption of electromagnetic radiation by atmospheric gases and water vapor is an accepted fact in terrestrial remote sensing. Until recently, only a general knowledge of atmospheric effects was required for analysis of remote sensing data; however, with the advent of high spectral resolution imaging devices, detailed knowledge of atmospheric absorption bands has become increasingly important for accurate analysis. Detailed study of high spectral resolution aircraft data at the U.S. Geological Survey has disclosed narrow absorption features centered at approximately 2.17 and 2.20 micrometers not caused by surface mineralogy. Published atmospheric transmission spectra and atmospheric spectra derived using the LOWTRAN-5 computer model indicate that these absorption features are probably water vapor. Spectral modeling indicates that the effects of atmospheric absorption in this region are most pronounced in spectrally flat materials with only weak absorption bands. Without correction and detailed knowledge of the atmospheric effects, accurate mapping of surface mineralogy (particularly at low mineral concentrations) is not possible.

  12. Durability Indicators in High Absorption Recycled Aggregate Concrete

    Directory of Open Access Journals (Sweden)

    Luis F. Jiménez

    2015-01-01

    Full Text Available The use of recycled aggregates in structural concrete production has the inconvenience of increasing the fluid transport properties, such as porosity, sorptivity, and permeability, which reduces the resistance against penetration of environmental loads such as carbon dioxide and chloride ion. In this paper, behavior of ten concrete mixtures with different percentages of coarse aggregate replacement was studied. The recycled material was recovered by crushing of concrete rubble and had high absorption values. The results showed that it is possible to achieve good resistance to carbonation and chloride penetration with up to 50% replacement of recycled coarse aggregate for 0.5 water/cement ratio. Finally, new indexes for porosity and sorptivity were proposed to assess the quality of concrete.

  13. SPATIALLY RESOLVED HCN ABSORPTION FEATURES IN THE CIRCUMNUCLEAR REGION OF NGC 1052

    Energy Technology Data Exchange (ETDEWEB)

    Sawada-Satoh, Satoko [Mizusawa VLBI Observatory, National Astronomical Observatory of Japan, 2-12 Hoshigaoka-cho, Mizusawa-ku, Oshu, Iwate 023-0861 (Japan); Roh, Duk-Gyoo; Oh, Se-Jin; Lee, Sang-Sung; Byun, Do-Young; Yeom, Jae-Hwan; Jung, Dong-Kyu; Kim, Hyo-Ryoung; Hwang, Ju-Yeon [Korea Astronomy and Space Science Institute, 776 Daedeok-daero, Yuseong, Daejeon 34055 (Korea, Republic of); Kameno, Seiji, E-mail: satoko.ss@nao.ac.jp, E-mail: sss@mx.ibaraki.ac.jp [Joint ALMA Observatory, Alonso de Cordova 3107 Vitacura, Santiago 763 0355 (Chile)

    2016-10-10

    We present the first VLBI detection of HCN molecular absorption in the nearby active galactic nucleus NGC 1052. Utilizing the 1 mas resolution achieved by the Korean VLBI Network, we have spatially resolved the HCN absorption against a double-sided nuclear jet structure. Two velocity features of HCN absorption are detected significantly at the radial velocity of 1656 and 1719 km s{sup −1}, redshifted by 149 and 212 km s{sup −1} with respect to the systemic velocity of the galaxy. The column density of the HCN molecule is estimated to be 10{sup 15}–10{sup 16} cm{sup −2}, assuming an excitation temperature of 100–230 K. The absorption features show high optical depth localized on the receding jet side, where the free–free absorption occurred due to the circumnuclear torus. The size of the foreground absorbing molecular gas is estimated to be on approximately one-parsec scales, which agrees well with the approximate size of the circumnuclear torus. HCN absorbing gas is likely to be several clumps smaller than 0.1 pc inside the circumnuclear torus. The redshifted velocities of the HCN absorption features imply that HCN absorbing gas traces ongoing infall motion inside the circumnuclear torus onto the central engine.

  14. Radial measurements of IMF-sensitive absorption features in two massive ETGs

    Science.gov (United States)

    Vaughan, Sam P.; Davies, Roger L.; Zieleniewski, Simon; Houghton, Ryan C. W.

    2018-03-01

    We make radial measurements of stellar initial mass function (IMF) sensitive absorption features in the two massive early-type galaxies NGC 1277 and IC 843. Using the Oxford Short Wavelength Integral Field specTrogaph (SWIFT), we obtain resolved measurements of the Na I 0.82 and FeH 0.99 indices, amongst others, finding both galaxies show strong gradients in Na I absorption combined with flat FeH profiles at ˜0.4 Å. We find these measurements may be explained by radial gradients in the IMF, appropriate abundance gradients in [Na/Fe] and [Fe/H], or a combination of the two, and our data are unable to break this degeneracy. We also use full spectral fitting to infer global properties from an integrated spectrum of each object, deriving a unimodal IMF slope consistent with Salpeter in IC 843 (x = 2.27 ± 0.17) but steeper than Salpeter in NGC 1277 (x = 2.69 ± 0.11), despite their similar FeH equivalent widths. Independently, we fit the strength of the FeH feature and compare to the E-MILES and CvD12 stellar population libraries, finding agreement between the models. The IMF values derived in this way are in close agreement with those from spectral fitting in NGC 1277 (x_{CvD}=2.59^{+0.25}_{-0.48}, x_{E-MILES}=2.77± 0.31), but are less consistent in IC 843, with the IMF derived from FeH alone leading to steeper slopes than when fitting the full spectrum (x_{CvD}=2.57^{+0.30}_{-0.41}, x_{E-MILES}=2.72± 0.25). This work highlights the importance of a large wavelength coverage for breaking the degeneracy between abundance and IMF variations, and may bring into doubt the use of the Wing-Ford band as an IMF index if used without other spectral information.

  15. Understanding the features in the ultrafast transient absorption spectra of CdSe quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Cheng; Do, Thanh Nhut [Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore); Ong, Xuanwei [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Chan, Yinthai [Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543 (Singapore); Institute of Materials Research & Engineering, A*STAR, 2 Fusionopolis Way, Innovis, Singapore 138634 (Singapore); Tan, Howe-Siang, E-mail: howesiang@ntu.edu.sg [Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371 (Singapore)

    2016-12-20

    We describe a model to explain the features of the ultrafast transient absorption (TA) spectra of CdSe core type quantum dots (QDs). The measured TA spectrum consists of contributions by the ground state bleach (GSB), stimulated emission (SE) and excited state absorption (ESA) processes associated with the three lowest energy transition of the QDs. We model the shapes of the GSB, SE and ESA spectral components after fits to the linear absorption. The spectral positions of the ESA components take into account the biexcitonic binding energy. In order to obtain the correct weightage of the GSB, SE and ESA components to the TA spectrum, we enumerate the set of coherence transfer pathways associated with these processes. From our fits of the experimental TA spectra of 65 Å diameter QDs, biexcitonic binding energies for the three lowest energy transitions are obtained.

  16. The application of feature selection to the development of Gaussian process models for percutaneous absorption.

    Science.gov (United States)

    Lam, Lun Tak; Sun, Yi; Davey, Neil; Adams, Rod; Prapopoulou, Maria; Brown, Marc B; Moss, Gary P

    2010-06-01

    The aim was to employ Gaussian processes to assess mathematically the nature of a skin permeability dataset and to employ these methods, particularly feature selection, to determine the key physicochemical descriptors which exert the most significant influence on percutaneous absorption, and to compare such models with established existing models. Gaussian processes, including automatic relevance detection (GPRARD) methods, were employed to develop models of percutaneous absorption that identified key physicochemical descriptors of percutaneous absorption. Using MatLab software, the statistical performance of these models was compared with single linear networks (SLN) and quantitative structure-permeability relationships (QSPRs). Feature selection methods were used to examine in more detail the physicochemical parameters used in this study. A range of statistical measures to determine model quality were used. The inherently nonlinear nature of the skin data set was confirmed. The Gaussian process regression (GPR) methods yielded predictive models that offered statistically significant improvements over SLN and QSPR models with regard to predictivity (where the rank order was: GPR > SLN > QSPR). Feature selection analysis determined that the best GPR models were those that contained log P, melting point and the number of hydrogen bond donor groups as significant descriptors. Further statistical analysis also found that great synergy existed between certain parameters. It suggested that a number of the descriptors employed were effectively interchangeable, thus questioning the use of models where discrete variables are output, usually in the form of an equation. The use of a nonlinear GPR method produced models with significantly improved predictivity, compared with SLN or QSPR models. Feature selection methods were able to provide important mechanistic information. However, it was also shown that significant synergy existed between certain parameters, and as such it

  17. Integration of Absorption Feature Information from Visible to Longwave Infrared Spectral Ranges for Mineral Mapping

    Directory of Open Access Journals (Sweden)

    Veronika Kopačková

    2017-09-01

    Full Text Available Merging hyperspectral data from optical and thermal ranges allows a wider variety of minerals to be mapped and thus allows lithology to be mapped in a more complex way. In contrast, in most of the studies that have taken advantage of the data from the visible (VIS, near-infrared (NIR, shortwave infrared (SWIR and longwave infrared (LWIR spectral ranges, these different spectral ranges were analysed and interpreted separately. This limits the complexity of the final interpretation. In this study a presentation is made of how multiple absorption features, which are directly linked to the mineral composition and are present throughout the VIS, NIR, SWIR and LWIR ranges, can be automatically derived and, moreover, how these new datasets can be successfully used for mineral/lithology mapping. The biggest advantage of this approach is that it overcomes the issue of prior definition of endmembers, which is a requested routine employed in all widely used spectral mapping techniques. In this study, two different airborne image datasets were analysed, HyMap (VIS/NIR/SWIR image data and Airborne Hyperspectral Scanner (AHS, LWIR image data. Both datasets were acquired over the Sokolov lignite open-cast mines in the Czech Republic. It is further demonstrated that even in this case, when the absorption feature information derived from multispectral LWIR data is integrated with the absorption feature information derived from hyperspectral VIS/NIR/SWIR data, an important improvement in terms of more complex mineral mapping is achieved.

  18. Designing basin-customized combined drought indices via feature extraction

    Science.gov (United States)

    Zaniolo, Marta; Giuliani, Matteo; Castelletti, Andrea

    2017-04-01

    The socio-economic costs of drought are progressively increasing worldwide due to the undergoing alteration of hydro-meteorological regimes induced by climate change. Although drought management is largely studied in the literature, most of the traditional drought indexes fail in detecting critical events in highly regulated systems, which generally rely on ad-hoc formulations and cannot be generalized to different context. In this study, we contribute a novel framework for the design of a basin-customized drought index. This index represents a surrogate of the state of the basin and is computed by combining the available information about the water available in the system to reproduce a representative target variable for the drought condition of the basin (e.g., water deficit). To select the relevant variables and how to combine them, we use an advanced feature extraction algorithm called Wrapper for Quasi Equally Informative Subset Selection (W-QEISS). The W-QEISS algorithm relies on a multi-objective evolutionary algorithm to find Pareto-efficient subsets of variables by maximizing the wrapper accuracy, minimizing the number of selected variables (cardinality) and optimizing relevance and redundancy of the subset. The accuracy objective is evaluated trough the calibration of a pre-defined model (i.e., an extreme learning machine) of the water deficit for each candidate subset of variables, with the index selected from the resulting solutions identifying a suitable compromise between accuracy, cardinality, relevance, and redundancy. The proposed methodology is tested in the case study of Lake Como in northern Italy, a regulated lake mainly operated for irrigation supply to four downstream agricultural districts. In the absence of an institutional drought monitoring system, we constructed the combined index using all the hydrological variables from the existing monitoring system as well as the most common drought indicators at multiple time aggregations. The soil

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

    Science.gov (United States)

    Yaqoob, Tahir; Serlemitsos, Peter

    2005-01-01

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

  20. Randic and Schultz molecular topological indices and their correlation with some X-ray absorption parameters

    International Nuclear Information System (INIS)

    Khatri, Sunil; Kekre, Pravin A; Mishra, Ashutosh

    2016-01-01

    The properties of a molecular system are affected by the topology of molecule. Therefore many studies have been made where the various physic-chemical properties are correlated with the topological indices. These studies have shown a very good correlation demonstrating the utility of the graph theoretical approach. It is, therefore, very natural to expect that the various physical properties obtained by the X-ray absorption spectra may also show correlation with the topological indices. Some complexes were used to establish correlation between topological indices and some X-ray absorption parameters like chemical shift. The chemical shift is on the higher energy side of the metal edge in these complexes. The result obtained in these studies shows that the topological indices of organic molecule acting as a legands can be used for estimating edge shift theoretically. (paper)

  1. Mg I absorption features in the solar spectrum near 9 and 12 microns

    Science.gov (United States)

    Glenar, David A.; Reuter, Dennis C.; Deming, Drake; Chang, Edward S.

    1988-01-01

    High-resolution FTS observations from the Kitt Peak National Solar Observatory and the Spacelab 3 ATMOS experiment have revealed additional infrared transitions due to Mg I in the spectra of both quiet sun and sunspot penumbra. In contrast to previous observations, these transitions are seen in absorption, not emission. Absorption intensities range from 1 to 7 percent of the continuum in the quiet sun. In the penumbra, the same features appear to show Zeeman splitting. Modeling of the line profiles in the photospheric spectrum shows evidence for a factor of three overabundance in the n = 5 or more levels of Mg I in the upper photosphere, but with no deviations from a Planck source function. It is concluded that whatever the process that produces the emission (including the Lemke and Holweger mechanism), it must occur well above the tau(5000) = 0.01 level.

  2. Exploring multivariate representations of indices along linear geographic features

    Science.gov (United States)

    Bleisch, Susanne; Hollenstein, Daria

    2018-05-01

    A study of the walkability of a Swiss town required finding suitable representations of multivariate geographical da-ta. The goal was to represent multiple indices of walkability concurrently and visualizing the data along the street network it relates to. Different indices of pedestrian friendliness were assessed for short street sections and then mapped to an overlaid grid. Basic and composite glyphs were designed using square- or triangle-areas to display one to four index values concurrently within the grid structure. Color was used to indicate different indices. Implement-ing visualizations for different combinations of index sets, we find that single values can be emphasized or de-emphasized by selecting the color scheme accordingly and that different color selections either allow perceiving sin-gle values or overall trends over the evaluated area. Values for up to four indices can be displayed in combination within the resulting geovisualizations and the underlying gridded road network references the data to its real world locations.

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

    Energy Technology Data Exchange (ETDEWEB)

    Cina, Jeffrey A., E-mail: cina@uoregon.edu; Kovac, Philip A. [Department of Chemistry and Biochemistry, and Oregon Center for Optical, Molecular, and Quantum Science, University of Oregon, Eugene, Oregon 97403 (United States); Jumper, Chanelle C. [Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6 (Canada); Dean, Jacob C.; Scholes, Gregory D., E-mail: gscholes@princeton.edu [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States)

    2016-05-07

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  5. The Associated Absorption Features in Quasar Spectra of the Sloan Digital Sky Survey. I. Mg II Absorption Doublets

    Science.gov (United States)

    Chen, Zhi-Fu; Huang, Wei-Rong; Pang, Ting-Ting; Huang, Hong-Yan; Pan, Da-Sheng; Yao, Min; Nong, Wei-Jing; Lu, Mei-Mei

    2018-03-01

    Using the SDSS spectra of quasars included in the DR7Q or DR12Q catalogs, we search for Mg II λλ2796, 2803 narrow absorption doublets in the spectra data around Mg II λ2798 emission lines. We obtain 17,316 Mg II doublets, within the redshift range of 0.3299 ≤ z abs ≤ 2.5663. We find that a velocity offset of υ r 6000 km s‑1. If associated Mg II absorbers are defined by υ r present at least one associated Mg II system with {W}{{r}}λ 2796≥slant 0.2 \\mathringA . The fraction of associated Mg II systems with high-velocity outflows correlates with the average luminosities of their central quasars, indicating a relationship between outflows and the quasar feedback power. The υ r distribution of the outflow Mg II absorbers is peaked at 1023 km s‑1, which is smaller than the corresponding value of the outflow C IV absorbers. The redshift number density evolution of absorbers (dn/dz) limited by υ r > ‑3000 km s‑1 differs from that of absorbers constrained by υ r > 2000 km s‑1. Absorbers limited by υ r > 2000 km s‑1 and higher values exhibit profiles similar to dn/dz. In addition, the dn/dz is smaller when absorbers are constrained with larger υ r . The distributions of equivalent widths, and the ratio of {W}rλ 2796/{W}rλ 2803, are the same for associated and intervening systems, and independent of quasar luminosity.

  6. Feature selection for anomaly–based network intrusion detection using cluster validity indices

    CSIR Research Space (South Africa)

    Naidoo, Tyrone

    2015-09-01

    Full Text Available data, which is rarely available in operational networks. It uses normalized cluster validity indices as an objective function that is optimized over the search space of candidate feature subsets via a genetic algorithm. Feature sets produced...

  7. Seagrass epiphytic assemblages are strong indicators of agricultural discharge but weak indicators of host features

    Science.gov (United States)

    Prado, Patricia

    2018-05-01

    Wastewater pulses from rice agriculture are persistently discharged into the northern shore of the Alfacs Bay (Ebro Delta, NW Mediterranean) from April to November. The bay also receives water from coastal lagoons which are subjected to freshwater inputs from the Ebro River mixed to an unknown extent with agricultural wastewater during the same period. This paper compares epiphyte assemblages growing on leaves of Cymodocea nodosa in sites exposed to agricultural drainage channels, lagoon connection channels, and control sites in the Ebro Delta Natural Park (southern shore of the bay). Leaf epiphytic assemblages of Zostera noltii patches in the northern shore of the bay were also compared with those of adjacent beds of C. nodosa. Drainage channel sites had consistently distinctive assemblages (higher species richness, biomass load, and taxa composition) than control sites. Assemblages from lagoon channel sites were more variable, with three sites showing particularly high covers of epiphytic algae and two sites more similar to controls. Epiphyte patterns clearly matched in situ measures of nutrient availability, and were consistent with decreased shoot densities in discharge sites. In contrast, differences in epiphyte assemblages between seagrass species were minor, and mostly a result of higher epiphytic loads on C. nodosa than on Z. noltii, which features thinner leaves. Further research is needed to investigate the consequences of these plant and epiphyte alterations in important ecosystem processes such as decomposition and export rates, as well as overall effects of nutrients and salinity in secondary producers such as associated macroinvertebrate assemblages supporting locally important marine fisheries.

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

    Science.gov (United States)

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

    2013-07-01

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

  9. Structural, thermal and optical absorption features of heavy metal oxides doped tellurite rich glasses

    Directory of Open Access Journals (Sweden)

    Kawa M. Kaky

    Full Text Available In order to improve tellurite glass stability to be applicable for optical fiber amplifier applications, glasses with the composition of (70 − xTeO2. (10ZnO. (10WO3. (5Na2O. (5TiO2. (xBi2O3 (x = 1, 2, 3, 4, and 5 mol% have been produced and characterized using the related methods. Structural properties were investigated using X-ray diffraction (XRD which confirms the non-crystalline structure and scanning electron microscopy (SEM micrographs also confirm the XRD results. The energy dispersive X-ray (EDX analysis profiles show that all the mentioned elements are present in the prepared glasses. Following the IR spectra, all the tellurium bonds such as stretching vibrations of TeO4 tbp and TeO3/TeO3+1 unit are revealed. Raman spectra confirm the presence of different functional groups, actually, it shows bands mainly in four spectral regions: R1 (65–150 cm−1, R2 (280–550 cm−1, R3 (880–950 cm−1 and R4 (916–926 cm−1 and the identified bands are assigned to respective molecular groups. The thermal study was carried out using Differential scanning calorimetry (DSC which indicates good thermal stability of the synthesized glasses with increasing Bi concentration. From the optical absorption spectra, we evaluated cut-off edge wavelengths and found increasing cutoff wavelength with an increase in Bi2O3 concentration. In the UV–Visible region, optical band gap energy and allowed transitions were investigated using three methods; direct, indirect, and absorption spectrum fitting (ASF, and band gaps from indirect and ASF were matched. Keywords: Tellurite glasses, XRD, FT-IR, Raman, TGA/DSC

  10. Structural, thermal and optical absorption features of heavy metal oxides doped tellurite rich glasses

    Science.gov (United States)

    Kaky, Kawa M.; Lakshminarayana, G.; Baki, S. O.; Kityk, I. V.; Taufiq-Yap, Y. H.; Mahdi, M. A.

    In order to improve tellurite glass stability to be applicable for optical fiber amplifier applications, glasses with the composition of (70 - x)TeO2. (10)ZnO. (10)WO3. (5)Na2O. (5)TiO2. (x)Bi2O3 (x = 1, 2, 3, 4, and 5 mol%) have been produced and characterized using the related methods. Structural properties were investigated using X-ray diffraction (XRD) which confirms the non-crystalline structure and scanning electron microscopy (SEM) micrographs also confirm the XRD results. The energy dispersive X-ray (EDX) analysis profiles show that all the mentioned elements are present in the prepared glasses. Following the IR spectra, all the tellurium bonds such as stretching vibrations of TeO4 tbp and TeO3/TeO3+1 unit are revealed. Raman spectra confirm the presence of different functional groups, actually, it shows bands mainly in four spectral regions: R1 (65-150) cm-1, R2 (280-550) cm-1, R3 (880-950) cm-1 and R4 (916-926) cm-1 and the identified bands are assigned to respective molecular groups. The thermal study was carried out using Differential scanning calorimetry (DSC) which indicates good thermal stability of the synthesized glasses with increasing Bi concentration. From the optical absorption spectra, we evaluated cut-off edge wavelengths and found increasing cutoff wavelength with an increase in Bi2O3 concentration. In the UV-Visible region, optical band gap energy and allowed transitions were investigated using three methods; direct, indirect, and absorption spectrum fitting (ASF), and band gaps from indirect and ASF were matched.

  11. Statistical Identification of Composed Visual Features Indicating High Likelihood of Grasp Success

    DEFF Research Database (Denmark)

    Thomsen, Mikkel Tang; Bodenhagen, Leon; Krüger, Norbert

    2013-01-01

    configurations of three 3D surface features that predict grasping actions with a high success probability. The strategy is based on first computing spatial relations between visual entities and secondly, exploring the cross-space of these relational feature space and grasping actions. The data foundation...... for identifying such indicative feature constellations is generated in a simulated environment wherein visual features are extracted and a large amount of grasping actions are evaluated through dynamic simulation. Based on the identified feature constellations, we validate by applying the acquired knowledge...

  12. Specific features of the temperature dependence of the exciton absorption integral in CdS crystals

    International Nuclear Information System (INIS)

    Novikov, A.B.; Solov'ev, L.E.; Talalaev, V.G.

    1986-01-01

    Cadmium sulfide crystals 0.4-2 μm thick in the 4.2-120 K temperature range are investigated experimentally. The shape of the first exciton absorption line in CdS and dependence of integral exciton absorption factor (IEAF) on the quenching constant j are calculated. Rapid growth of the absorption factor in the maximum of the absorption line and decrease of halfwidth of the factor are shown to take place with j increase. The calculation has disclosed that the Bouguer law is observed excluding negligible IEAF oscillations at variation of crystal thickness. Non-monotonous temperature dependence of IEAF is disclosed in some investigated samples; it, obviously, testifies to non-monotonous temperature dependence of j. Depolarization of the absorption line of high-energy exciton states with n=2 and n=3 is discovered in some samples for the first time

  13. Unified picture of the photoexcitations in phenylene-based conjugated polymers: Universal spectral and dynamical features in subpicosecond transient absorption

    International Nuclear Information System (INIS)

    Kraabel, B.; Klimov, V. I.; Kohlman, R.; Xu, S.; Wang, H-L.; McBranch, D. W.

    2000-01-01

    Using subpicosecond transient absorption spectroscopy, we investigate the primary photoexcitations in thin films and solutions of several phenylene-based conjugated polymers and an oligomer. We identify several features in the transient absorption spectra and dynamics that are common to all of the materials which we studied from this family. The first spectral feature is a photoinduced absorption (PA) band peaking near 1 eV that has intensity-dependent dynamics that match the stimulated emission dynamics exactly over two orders of magnitude in excitation density. This band is associated with singlet intrachain excitons. The second spectral feature (observed only in thin films and aggregated solutions) is a PA band peaking near 1.8 eV, that is longer lived than the 1 eV exciton PA band, and that has dynamics that are independent (or weakly dependent) on excitation density. This feature is attributed to polarons, generated through a mechanism that is sample dependent. In pristine samples, polarons are generated via a mechanism that is quadratic in exciton density, whereas in photodegraded samples or samples doped with electron acceptors, the generation mechanism becomes linear in exciton density. (c) 2000 The American Physical Society

  14. Characteristic features of optical absorption for Gd2O3 and NiO nanoparticles

    Science.gov (United States)

    Zatsepin, A. F.; Kuznetsova, Yu. A.; Rychkov, V. N.; Sokolov, V. I.

    2017-03-01

    The technical approach to determination of the structural and optical parameters of oxides with reduced dimensionality based on optical absorption measurements is described by example of gadolinium and nickel oxides. It was established that the temperature behavior of fundamental absorption edge for oxide nanoparticles is similar with the bulk materials with crystal structure. At the same time, the energy characteristics (band gap and effective phonon energies) for low-dimensional oxides are found to be significantly different from their bulk counterparts. The presented methodological method to obtain of qualitative and quantitative correlations of structural and optical characteristics provides novel reliable knowledge of nanoscaled 3d and 4f-metal oxide materials that is useful for development of their practical applications.

  15. Characteristic features of optical absorption for Gd2O3 and NiO nanoparticles

    International Nuclear Information System (INIS)

    Zatsepin, A. F.; Kuznetsova, Yu. A.; Rychkov, V. N.; Sokolov, V. I.

    2017-01-01

    The technical approach to determination of the structural and optical parameters of oxides with reduced dimensionality based on optical absorption measurements is described by example of gadolinium and nickel oxides. It was established that the temperature behavior of fundamental absorption edge for oxide nanoparticles is similar with the bulk materials with crystal structure. At the same time, the energy characteristics (band gap and effective phonon energies) for low-dimensional oxides are found to be significantly different from their bulk counterparts. The presented methodological method to obtain of qualitative and quantitative correlations of structural and optical characteristics provides novel reliable knowledge of nanoscaled 3d and 4f–metal oxide materials that is useful for development of their practical applications.

  16. The value of anthropometric indices for identifying women with features of metabolic syndrome

    Science.gov (United States)

    BMI is a widely used anthropometric measure for identifying CVD and metabolic syndrome (MetS) risk. Two new anthropometric indices are A Body Shape Index (ABSI) and Body Roundness Index (BRI) that may provide better correlations to features of MetS. Methods: Subject data were obtained from 91 over...

  17. A robust indicator based on singular value decomposition for flaw feature detection from noisy ultrasonic signals

    Science.gov (United States)

    Cui, Ximing; Wang, Zhe; Kang, Yihua; Pu, Haiming; Deng, Zhiyang

    2018-05-01

    Singular value decomposition (SVD) has been proven to be an effective de-noising tool for flaw echo signal feature detection in ultrasonic non-destructive evaluation (NDE). However, the uncertainty in the arbitrary manner of the selection of an effective singular value weakens the robustness of this technique. Improper selection of effective singular values will lead to bad performance of SVD de-noising. What is more, the computational complexity of SVD is too large for it to be applied in real-time applications. In this paper, to eliminate the uncertainty in SVD de-noising, a novel flaw indicator, named the maximum singular value indicator (MSI), based on short-time SVD (STSVD), is proposed for flaw feature detection from a measured signal in ultrasonic NDE. In this technique, the measured signal is first truncated into overlapping short-time data segments to put feature information of a transient flaw echo signal in local field, and then the MSI can be obtained from the SVD of each short-time data segment. Research shows that this indicator can clearly indicate the location of ultrasonic flaw signals, and the computational complexity of this STSVD-based indicator is significantly reduced with the algorithm proposed in this paper. Both simulation and experiments show that this technique is very efficient for real-time application in flaw detection from noisy data.

  18. Phase-dependent absorption features in X-ray spectra of X-ray Dim Isolated Neutron Stars

    Science.gov (United States)

    Borghese, A.; Rea, N.; Coti Zelati, F.; Turolla, R.; Tiengo, A.; Zane, S.

    2017-12-01

    A detailed phase-resolved spectroscopy of archival XMM-Newton observations of X-ray Dim Isolated Neutron Stars (XDINSs) led to the discovery of narrow and strongly phase-dependent absorption features in two of these sources. The first was discovered in the X-ray spectrum of RX J0720.4-3125, followed by a new possible candidate in RX J1308.6+2127. Both spectral lines have similar properties: they are detected for only ˜ 20% of the rotational cycle and appear to be stable over the timespan covered by the observations. We performed Monte Carlo simulations to test the significance of these phase-variable features and in both cases the outcome has confirmed the detection with a confidence level > 4.6σ. Because of the narrow width and the strong dependence on the pulsar rotational phase, the most likely interpretation for these spectral features is in terms of resonant proton cyclotron absorption scattering in a confined high-B structure close to the stellar surface. Within the framework of this interpretation, our results provide evidence for deviations from a pure dipole magnetic field on small scales for highly magnetized neutron stars and support the proposed scenario of XDINSs being aged magnetars, with a strong non-dipolar crustal B-field component.

  19. Reconfiguration of spectral absorption features using a frequency-chirped laser pulse.

    Science.gov (United States)

    Tian, Mingzhen; Chang, Tiejun; Merkel, Kristian D; Babbitt, W Randall

    2011-12-20

    A technique is proposed to manipulate atomic population in an inhomogeneously broadened medium, which can set an arbitrary absorption spectrum to a uniform transparency (erasure) or to a nearly complete inversion. These reconfigurations of atomic spectral distribution are achieved through excitation of electronic transitions using a laser pulse with chirped frequency, which precisely affects selected spectral regions while leaving the rest of the spectrum unperturbed. An erasure operation sets the final atomic population inversion to zero and the inversion operation flips the population between the ground and the excited states, regardless of the previously existing population distribution. This technique finds important applications both in optical signal processing, where fast, recursive processing and high dynamic range are desirable and in quantum memory and quantum computing, which both require high efficiency and high fidelity in quantum state preparation of atomic ensembles. Proof-of-concept demonstrations were performed in a rare-earth doped crystal.

  20. MEMBRANOUS FLOWS IN GAS-LIQUID COLLECTORS-REGENERATORS OF SOLAR ABSORPTIVE SYSTEMS FEATURES

    Directory of Open Access Journals (Sweden)

    Doroshenko А.V.

    2009-12-01

    Full Text Available Article is devoted to the creation of new generation of solar collectors of the gas-liquid type, intended for use in alternative refrigerating and conditioning systems of drying-evaporating type with direct solar regeneration of absorbent. Special attention is given to the study of membranous flows features on inclined surfaces, including questions of such flows stability.

  1. Synthesis and Investigation Absorption Features of Some Novel Hetarylazo Dyes Derived from Calix[4]resorcinarene

    Directory of Open Access Journals (Sweden)

    İzzet Şener

    2013-12-01

    Full Text Available In this study, several derivatives of amines were diazotized and coupled with 3-aminocrotonitrile to give 2-arylhydrazon-3-ketiminocrotononitrile. The synthesized components were then refluxed with hydrazine hydrate in ethanol to give a series of dyes 5-amino-4-arylazo-3-ethyl-1'H-Pyrazole. The synthesized dyes were diazotised and coupled with resorcinarene, which was obtained from condensation of between resorcinol and acetaldehyde, to give a new synthesis of azo dyes based on resorcinarene. The structures of synthesized dyes based on resorcinarene were characterized by spectral methods. The effect of varying solvents, acid and base upon the absorption spectra of resultant dyes has been investigated. Key words: Resorcinarene, Azo Dyes, Absorption Spectra, Solvent Effect, Acid-Base Effect Rezorsinaren Bazlı Azo Boyarmaddelerin Sentezi ve Absorpsiyon Özelliklerinin İncelenmesi Özet: Bu çalışmada, çeşitli amin türevleri diazolanmış ve 3-aminokrotonitril ile kenetlenerek 2-arilhidrazon-3-ketiminokrotononitril bileşikleri elde edilmiştir. Elde edilen bileşikler, hidrazinhidrat ile etanol içerisinde reflaks edilerek bir seri 5-amino-4-arilazo-3-metil-1'H-pirazol boyaları elde edilmiştir. Elde edilen boyalar diazonlarak rezorsinol ve asetaldehit arasındaki kondenzasyondan elde edilen rezorsinaren bileşiği ile kenetlenmiş ve rezorsinaren bazlı azo boyarmaddeler sentezlenmiştir. Sentezlenen rezorsinaren bazlı azoboyarmaddelerin yapıları spektrofotometrik yöntemler kullanılarak incelendi. Sentezlenen boyarmaddelerin görünür bölge absorpsiyon spektrumları üzerine değişik çözücü, asit ve baz etkileri incelendi. Anahtar kelimeler: Rezorsiaren, Azo Boyarmadde, Absorpsiyon Spektrumu, Çözücü Etkisi, Asit-Baz Etkisi

  2. Clinical Features Indicating Nigrostriatal Dopaminergic Degeneration in Drug-Induced Parkinsonism

    Directory of Open Access Journals (Sweden)

    Seung Ha Lee

    2017-01-01

    Full Text Available Objective Patients with drug-induced parkinsonism (DIP may have nigrostriatal dopaminergic degeneration. We studied the clinical features that may indicate nigrostriatal dopaminergic degeneration in patients with DIP. Methods Forty-one DIP patients were classified into normal and abnormal [18F] FP-CIT scan groups. Differences in 32 clinical features and drug withdrawal effects were studied. Results Twenty-eight patients had normal (Group I and 13 patients had abnormal (Group II scans. Eight patients of Group I, but none of Group II, had taken calcium channel blockers (p = 0.040. Three patients of Group I and six of Group II had hyposmia (p = 0.018. After drug withdrawal, Group I showed greater improvement in Unified Parkinson’s Disease Rating Scale total motor scores and subscores for bradykinesia and tremors than Group II. Only hyposmia was an independent factor associated with abnormal scans, but it had suboptimal sensitivity. Conclusion None of the clinical features were practical indicators of nigrostriatal dopaminergic degeneration in patients with DIP.

  3. Holo-transcobalamin is an indicator of vitamin B-12 absorption in healthy adults with adequate vitamin B-12 status

    DEFF Research Database (Denmark)

    von Castel-Roberts, Kristina M; Mørkbak, Anne Louise; Nexo, Ebba

    2007-01-01

    BACKGROUND: It has been hypothesized that the response of holo-transcobalamin (holo-TC) to oral vitamin B-12 may be used to assess absorption. To develop a reliable clinical absorption test that uses holo-TC, it is necessary to determine the optimal timeline for vitamin B-12 administration...... and postdose assessment. OBJECTIVE: The objective of this study was to assess the magnitude and patterns of change in the postabsorption response of holo-TC to oral vitamin B-12. DESIGN: Adult (18-49 y) male and female participants (n = 21) with normal vitamin B-12 status were given three 9-mug doses...... of vitamin B-12 at 6-h intervals beginning early morning (baseline) on day 1. Blood was drawn at 17 timed intervals over the course of 3 d for the analysis of holo-TC and other indicators of vitamin B-12 status. RESULTS: Mean holo-TC increased significantly (P

  4. Retrieval of canopy water content of different crop types with two new hyperspectral indices: Water Absorption Area Index and Depth Water Index

    Science.gov (United States)

    Pasqualotto, Nieves; Delegido, Jesús; Van Wittenberghe, Shari; Verrelst, Jochem; Rivera, Juan Pablo; Moreno, José

    2018-05-01

    Crop canopy water content (CWC) is an essential indicator of the crop's physiological state. While a diverse range of vegetation indices have earlier been developed for the remote estimation of CWC, most of them are defined for specific crop types and areas, making them less universally applicable. We propose two new water content indices applicable to a wide variety of crop types, allowing to derive CWC maps at a large spatial scale. These indices were developed based on PROSAIL simulations and then optimized with an experimental dataset (SPARC03; Barrax, Spain). This dataset consists of water content and other biophysical variables for five common crop types (lucerne, corn, potato, sugar beet and onion) and corresponding top-of-canopy (TOC) reflectance spectra acquired by the hyperspectral HyMap airborne sensor. First, commonly used water content index formulations were analysed and validated for the variety of crops, overall resulting in a R2 lower than 0.6. In an attempt to move towards more generically applicable indices, the two new CWC indices exploit the principal water absorption features in the near-infrared by using multiple bands sensitive to water content. We propose the Water Absorption Area Index (WAAI) as the difference between the area under the null water content of TOC reflectance (reference line) simulated with PROSAIL and the area under measured TOC reflectance between 911 and 1271 nm. We also propose the Depth Water Index (DWI), a simplified four-band index based on the spectral depths produced by the water absorption at 970 and 1200 nm and two reference bands. Both the WAAI and DWI outperform established indices in predicting CWC when applied to heterogeneous croplands, with a R2 of 0.8 and 0.7, respectively, using an exponential fit. However, these indices did not perform well for species with a low fractional vegetation cover (<30%). HyMap CWC maps calculated with both indices are shown for the Barrax region. The results confirmed the

  5. FEATURES OF THE APPLICATION OF STATISTICAL INDICATORS OF SCHEDULED FLIGHTS OF AIRCRAFT

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available Тhe possibilities of increasing the effectiveness of management of safety of regular aircraft operations on the basis of systematic approach, under normal operating conditions are considered. These new opportunities within the airline are based on Flight Safety Management System integration with quality management system. So far, however, these possibili- ties are practically not implemented due to the limited application of statistical methods. A necessary condition for the implementation of the proposed approach is the use of statistical flight data results of the quality control flight. The proper- ties and peculiarities of application of statistical indicators of flight parameters during the monitoring of flight data are analyzed. It is shown that the main statistical indicators of the controlled process are averages and variations. The features of the application of theoretical models of mathematical statistics in the analysis of flight information are indicated. It is noted that in practice the theoretical models often do not fit into the framework of its application because of the violation of the initial assumptions. Recommendations are given for the integrated use of statistical indicators of the current quality control of flights. Ultimately, the article concludes that the capabilities of the proposed approach allows on the basis of knowledge about the dynamics of statistical indicators of controlled flight process to identify hazards and develop safety indicators for the new information based on data flight operation aircraft.

  6. Searches for 3.5 keV Absorption Features in Cluster AGN Spectra

    Science.gov (United States)

    Conlon, Joseph P.

    2018-06-01

    We investigate possible evidence for a spectral dip around 3.5 keV in central cluster AGNs, motivated by previous results for archival Chandra observations of the Perseus cluster and the general interest in novel spectral features around 3.5 keV that may arise from dark matter physics. We use two deep Chandra observations of the Perseus and Virgo clusters that have recently been made public. In both cases, mild improvements in the fit (Δχ2 = 4.2 and Δχ2 = 2.5) are found by including such a dip at 3.5 keV into the spectrum. A comparable result (Δχ2 = 6.5) is found re-analysing archival on-axis Chandra ACIS-S observations of the centre of the Perseus cluster.

  7. Identifying Features of Bodily Expression As Indicators of Emotional Experience during Multimedia Learning

    Directory of Open Access Journals (Sweden)

    Valentin Riemer

    2017-07-01

    Full Text Available The importance of emotions experienced by learners during their interaction with multimedia learning systems, such as serious games, underscores the need to identify sources of information that allow the recognition of learners’ emotional experience without interrupting the learning process. Bodily expression is gaining in attention as one of these sources of information. However, to date, the question of how bodily expression can convey different emotions has largely been addressed in research relying on acted emotion displays. Following a more contextualized approach, the present study aims to identify features of bodily expression (i.e., posture and activity of the upper body and the head that relate to genuine emotional experience during interaction with a serious game. In a multimethod approach, 70 undergraduates played a serious game relating to financial education while their bodily expression was captured using an off-the-shelf depth-image sensor (Microsoft Kinect. In addition, self-reports of experienced enjoyment, boredom, and frustration were collected repeatedly during gameplay, to address the dynamic changes in emotions occurring in educational tasks. Results showed that, firstly, the intensities of all emotions indeed changed significantly over the course of the game. Secondly, by using generalized estimating equations, distinct features of bodily expression could be identified as significant indicators for each emotion under investigation. A participant keeping their head more turned to the right was positively related to frustration being experienced, whereas keeping their head more turned to the left was positively related to enjoyment. Furthermore, having their upper body positioned more closely to the gaming screen was also positively related to frustration. Finally, increased activity of a participant’s head emerged as a significant indicator of boredom being experienced. These results confirm the value of bodily

  8. Study of influencing factors to chromophoric dissolved organic matter absorption properties from fluorescence features in Taihu lake in autumn

    Directory of Open Access Journals (Sweden)

    Chuang-Chun Huang

    2013-04-01

    Full Text Available In order to identify the components of chromophoric dissolved organic matter (CDOM, confirm the influence of components to the absorption coefficient of CDOM (aCDOM, and estimate aCDOM from fluorescence spectra, fluorescence and optical measurements of CDOM were carried out in November 2008. The results indicate that, the primary component of CDOM is humic-like. The secondary component is tryptophan-like, which is the product of phytoplankton and aquatic debris rather than the wastewater treatment drainaged from city. In this study, six fluorophores with multiple excitation-emission matrices (EEMs peaks (A, B, C, N, M, T were identified according to the parallel factor analysis (PARAFAC. The average contribution of each component to the CDOM is 19.93, 18.82, 16.88, 16.39, 12.26, and 15.72%, respectively. Red Shifted phenomenon will happen with the increase of fluorescence intensity for ultraviolet and terrestrially humic-like. Conversely, marine humic-like will appear Reverse Red Shifted with the increase of fluorescence intensity. The primary contributor to the shoulder value of CDOM’s absorption coefficient at 275 nm is phytoplankton productivity, followed by marine humic-like. The main contributors to the shoulder shape are UV humic-like and phytoplankton productivity, followed by marine humic-like and tryptophan-like. A strong correlation between CDOM absorption and fluorescence intensity at emission wavelength of 424 nm and excitation wavelength ranging from 280 to 360 nm was found. The absorption coefficient can be retrieved successfully from the same excitation wavelength’s fluorescence intensity by an exponential model.

  9. Defining Mediterranean and Black Sea biogeochemical subprovinces and synthetic ocean indicators using mesoscale oceanographic features

    DEFF Research Database (Denmark)

    Nieblas, Anne-Elise; Drushka, Kyla; Reygondeau, Gabriel

    2014-01-01

    variables to define integrative indices to monitor the environmental changes within each resultant subprovince at monthly resolutions. Using both the classical and mesoscale features, we find five biogeochemical subprovinces for the Mediterranean and Black Seas. Interestingly, the use of mesoscale variables......The Mediterranean and Black Seas are semi-enclosed basins characterized by high environmental variability and growing anthropogenic pressure. This has led to an increasing need for a bioregionalization of the oceanic environment at local and regional scales that can be used for managerial...... applications as a geographical reference. We aim to identify biogeochemical subprovinces within this domain, and develop synthetic indices of the key oceanographic dynamics of each subprovince to quantify baselines from which to assess variability and change. To do this, we compile a data set of 101 months...

  10. Visual feature integration indicated by pHase-locked frontal-parietal EEG signals.

    Science.gov (United States)

    Phillips, Steven; Takeda, Yuji; Singh, Archana

    2012-01-01

    The capacity to integrate multiple sources of information is a prerequisite for complex cognitive ability, such as finding a target uniquely identifiable by the conjunction of two or more features. Recent studies identified greater frontal-parietal synchrony during conjunctive than non-conjunctive (feature) search. Whether this difference also reflects greater information integration, rather than just differences in cognitive strategy (e.g., top-down versus bottom-up control of attention), or task difficulty is uncertain. Here, we examine the first possibility by parametrically varying the number of integrated sources from one to three and measuring phase-locking values (PLV) of frontal-parietal EEG electrode signals, as indicators of synchrony. Linear regressions, under hierarchical false-discovery rate control, indicated significant positive slopes for number of sources on PLV in the 30-38 Hz, 175-250 ms post-stimulus frequency-time band for pairs in the sagittal plane (i.e., F3-P3, Fz-Pz, F4-P4), after equating conditions for behavioural performance (to exclude effects due to task difficulty). No such effects were observed for pairs in the transverse plane (i.e., F3-F4, C3-C4, P3-P4). These results provide support for the idea that anterior-posterior phase-locking in the lower gamma-band mediates integration of visual information. They also provide a potential window into cognitive development, seen as developing the capacity to integrate more sources of information.

  11. Measuring for Absorption: How the Institutionalisation of EU Cohesion Policy Influences the Use of Performance Indicators in Hungary

    Directory of Open Access Journals (Sweden)

    Mike Károly

    2015-12-01

    Full Text Available We investigate the performance measurement of the implementing agencies of EU Structural Funds in Hungary. Following the advice of Thiel and Leeuw (2002, we focus on the incentives created by the institutional environment of these agencies. The core of this environment is a double principal-agent relationship between the European Commission (EC, the national government and the Managing Authority. We investigate its institutional features and the resulting organisational incentives for Managing Authorities in Hungary. Relying on programme evaluations, we explore how these incentives actually affected the design and use of performance measurement by Authorities in two policy fields: active labour-market policy and higher education. We find that external incentives to focus on absorption and formal compliance created bias against integrating performance measurement into the policy process and tackling problems of performance risk and non-measurability.

  12. Investigation of the relationship between dermoscopic features and histopathological prognostic indicators in patients with cutaneous melanoma

    Directory of Open Access Journals (Sweden)

    Özlem Özbağçıvan

    2015-09-01

    Full Text Available Background and Design: Dermoscopy has an important role in the diagnosis of melanoma nowadays. Dermoscopic findings of melanoma had been associated with Breslow thickness and invasion status in previous studies but the relationship between dermatoscopic findings and other histopathological prognostic indicators has not been investigated until today. In this study, our aim is to investigate the relationship between dermatoscopic findings and histopathologic prognostic indicators such as Breslow thickness, invasion status, mitotic rate, lymphovascular invasion (LVI, ulceration and regression in patients who had been diagnosed with melanoma due to their clinical, dermatoscopic and histopatological findings. Materials and Methods: Dermoscopic and histopathological findings of 47 cases of melanoma who applied to our clinic between the years 2000 and 2014 were evaluated. The relationship between the dermoscopic findings which had been reported to be observed in melanomas in previous research and the histopathologic prognostic indicators such as Breslow thickness, invasion status, mitotic rate, lymphovascular invasion, ulceration and regression were investigated. Results: Irregular dots/globules, atypical pigment network, multifocal hypopigmentation, radial streaks and moth-eaten borders have been associated with good prognostic indicators whereas comedo like openings, regular blotch, exophytic papillary structures, dotted, glomerular, lineer irregular vessels, pink/red and blue/gray colors were associated with poor prognostic indicators. Additionally some dermatoscopic findings which are more observed in benign lesions such as multiple milia-like cysts, comedo like openings, moth-eaten borders, regular blotch, exophytic papillary structures and finger print areas have been observed in melanomas in our study. Conclusion: Many dermoscopic findings have demonstrated statistically significant association with the histopathological prognostic indicators

  13. Spectroscopic remote sensing of plant stress at leaf and canopy levels using the chlorophyll 680 nm absorption feature with continuum removal

    Science.gov (United States)

    Sanches, Ieda Del´Arco; Souza Filho, Carlos Roberto de; Kokaly, Raymond F.

    2014-01-01

    This paper explores the use of spectral feature analysis to detect plant stress in visible/near infrared wavelengths. A time series of close range leaf and canopy reflectance data of two plant species grown in hydrocarbon-contaminated soil was acquired with a portable spectrometer. The ProSpecTIR-VS airborne imaging spectrometer was used to obtain far range hyperspectral remote sensing data over the field experiment. Parameters describing the chlorophyll 680 nm absorption feature (depth, width, and area) were derived using continuum removal applied to the spectra. A new index, the Plant Stress Detection Index (PSDI), was calculated using continuum-removed values near the chlorophyll feature centre (680 nm) and on the green-edge (560 and 575 nm). Chlorophyll feature’s depth, width and area, the PSDI and a narrow-band normalised difference vegetation index were evaluated for their ability to detect stressed plants. The objective was to analyse how the parameters/indices were affected by increasing degrees of plant stress and to examine their utility as plant stress indicators at the remote sensing level (e.g. airborne sensor). For leaf data, PSDI and the chlorophyll feature area revealed the highest percentage (67–70%) of stressed plants. The PSDI also proved to be the best constraint for detecting the stress in hydrocarbon-impacted plants with field canopy spectra and airborne imaging spectroscopy data. This was particularly true using thresholds based on the ASD canopy data and considering the combination of higher percentage of stressed plants detected (across the thresholds) and fewer false-positives.

  14. Exploring Socio-Technical Features of Green Interior Design of Residential Buildings: Indicators, Interdependence and Embeddedness

    Directory of Open Access Journals (Sweden)

    Yan Ning

    2016-12-01

    Full Text Available This research aims to develop indicators for assessing green interior design of new residential buildings in China, grounded in the socio-technical systems approach. The research was carried out through a critical literature review and two focus group studies. The results show that the boundaries of green interior design were identified with respect to three dimensions, namely performance, methodology and stakeholders. The socio-technical systems approach argues for the recognition of the interdependence between the systems elements and the feature of embeddedness. The interdependence of the systems elements exists within each of these three dimensions and across them. It is also found that the socio-technical systems of green interior design are embedded in the social, regulatory and geographic context. Taking interior design of residential buildings as the empirical setting, this study contributes to the literature of green building assessment by presenting a socio-technical systems approach.

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

    Science.gov (United States)

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

    2001-01-01

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

  16. Geomorphic features as indicators of climatic fluctuations in a periglacial environment, northern Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Nyberg, R; Lindh, L [Lund Univ. (SE). Dept. of Physical Geography

    1990-01-01

    Goemorphic responses to climatic fluctuations in the periglacial mountain environment of northern Sweden, especially the Abisko mountains, are discussed. Although the frequency and magnitude of rapid mass movements are related to climatic conditions, the depositional patterns of the processes and the variable availability of source material complicate their use as climatic indicators. Possibly, debris flows and slushflows were frequent during the Little Ice Age, according to lichenometric dating of old deposits. Field observations suggest a fairly high frequency also during the last few decades. Boulder pavements, moraine-like ridges and glacial striae in front of major snowfields indicate these were previously larger and in some cases active as small glaciers perhaps in the cold beginning of the 1900's. During the warm 1920-30's snowpatches and glaciers, as well as permafrost mounds were affected by a general degeneration. Climatic inferences made from the mentioned features are still very crude. Tentatively, it is suggested that they are presently beginning to respond to the cooling trend affecting northern Scandinavia since about 1940. The anticipated impact of a greenhouse warming of the atmosphere has thus so far not been noticeable in this high latitude area. (authors).

  17. Antimony orthophosphate glasses with large nonlinear refractive indices, low two-photon absorption coefficients, and ultrafast response

    International Nuclear Information System (INIS)

    Falcao-Filho, E.L.; Araujo, Cid B. de; Bosco, C.A.C.; Maciel, G.S.; Acioli, L.H.; Nalin, M.; Messaddeq, Y.

    2005-01-01

    Antimony glasses based on the composition Sb 2 O 3 -SbPO 4 were prepared and characterized. The samples present high refractive index, good transmission from 380 to 2000 nm, and high thermal stability. The nonlinear refractive index, n 2 , of the samples was studied using the optical Kerr shutter technique at 800 nm. The third-order correlation signals between pump and probe pulses indicate ultrafast response ( 2 was observed by adding lead oxide to the Sb 2 O 3 -SbPO 4 composition. Large values of n 2 ≅10 -14 cm 2 /W and negligible two-photon absorption coefficients (smaller than 0.01 cm/GW) were determined for all samples. The glass compositions studied present appropriate figure-of-merit for all-optical switching applications

  18. Constraints on the OH-to-H Abundance Ratio in Infrared-bright Galaxies Derived from the Strength of the OH 35 μm Absorption Feature

    Science.gov (United States)

    Stone, Myra; Veilleux, Sylvain; González-Alfonso, Eduardo; Spoon, Henrik; Sturm, Eckhard

    2018-02-01

    We analyze Spitzer/InfraRed Spectrograph (IRS) observations of the OH 35 μm feature in 15 nearby (z ≲ 0.06) (ultra-)luminous infrared galaxies (U/LIRGs). All objects exhibit OH 35 μm purely in absorption, as expected. The small optical depth of this transition makes the strength of this feature a good indicator of the true OH column density. The measured OH 35 μm equivalent widths imply an average OH column density and a 1-σ standard deviation to the mean of {N}{OH}=1.31+/- 0.22× {10}17 cm‑2. This number is then compared with the hydrogen column density for a typical optical depth at 35 μm of ∼0.5 and gas-to-dust ratio of 125 to derive an OH-to-H abundance ratio of {X}{OH}=1.01+/- 0.15× {10}-6. This abundance ratio is formally a lower limit. It is consistent with the values generally assumed in the literature. The OH 35 μm line profiles predicted from published radiative transfer models constrained by observations of OH 65, 79, 84, and 119 μm in 5 objects (Mrk 231, Mrk 273, IRAS F05189-2524, IRAS F08572+3915, and IRAS F20551-4250) are also found to be consistent with the IRS OH 35 μm spectra.

  19. Environmental Temperature Effect on the Far-Infrared Absorption Features of Aromatic-Based Titan's Aerosol Analogs

    Science.gov (United States)

    Gautier, Thomas; Trainer, Melissa G.; Loeffler, Mark J.; Sebree, Joshua A.; Anderson, Carrie M.

    2016-01-01

    Benzene detection has been reported in Titans atmosphere both in the stratosphere at ppb levels by remote sensing and in the thermosphere at ppm levels by the Cassini's Ion and Neutral Mass Spectrometer. This detection supports the idea that aromatic and heteroaromatic reaction pathways may play an important role in Titans atmospheric chemistry, especially in the formation of aerosols. Indeed, aromatic molecules are easily dissociated by ultraviolet radiation and can therefore contribute significantly to aerosol formation. It has been shown recently that aerosol analogs produced from a gas mixture containing a low concentration of aromatic and/or heteroaromatic molecules (benzene, naphthalene, pyridine, quinoline and isoquinoline) have spectral signatures below 500/cm, a first step towards reproducing the aerosol spectral features observed by Cassini's Composite InfraRed Spectrometer (CIRS) in the far infrared. In this work we investigate the influence of environmental temperature on the absorption spectra of such aerosol samples, simulating the temperature range to which aerosols, once formed, are exposed during their transport through Titans stratosphere. Our results show that environmental temperature does not have any major effect on the spectral shape of these aerosol analogs in the far-infrared, which is consistent with the CIRS observations.

  20. Dynamic MR defecography of the posterior compartment: Indications, techniques and MRI features

    International Nuclear Information System (INIS)

    Mortele, Koenraad J.; Fairhurst, Janice

    2007-01-01

    Pelvic floor weakness is characterized by abnormal symptomatic displacement of pelvic organs. It represents a complex clinical problem most commonly seen in middle-aged and elderly parous women. Its diagnosis remains difficult in many cases, since these disorders typically present with nonspecific symptoms, such as pelvic pain, incontinence and constipation. Fluoroscopic colpocystodefecography has been proven to surpass physical examination in the detection and characterization of functional abnormalities of the anorectum and surrounding pelvic structures. Similarly, MR defecography, performed either with an open- or closed-configuration unit, appears to be an accurate imaging technique to assess clinically relevant pelvic floor abnormalities. Moreover, MR defecography negates the need to expose the patient to harmful ionizing radiation and allows excellent depiction of the surrounding soft tissues of the pelvis. In this manuscript, we review the techniques and indications of MR defecography, and illustrate the MRI features of a vast array of morphologic and functional pelvic floor disorders, with emphasis on the posterior pelvic compartment (anorectum)

  1. Dynamic MR defecography of the posterior compartment: Indications, techniques and MRI features

    Energy Technology Data Exchange (ETDEWEB)

    Mortele, Koenraad J. [Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston MA 02115 (United States)]. E-mail: kmortele@partners.org; Fairhurst, Janice [Division of Abdominal Imaging and Intervention, Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston MA 02115 (United States)

    2007-03-15

    Pelvic floor weakness is characterized by abnormal symptomatic displacement of pelvic organs. It represents a complex clinical problem most commonly seen in middle-aged and elderly parous women. Its diagnosis remains difficult in many cases, since these disorders typically present with nonspecific symptoms, such as pelvic pain, incontinence and constipation. Fluoroscopic colpocystodefecography has been proven to surpass physical examination in the detection and characterization of functional abnormalities of the anorectum and surrounding pelvic structures. Similarly, MR defecography, performed either with an open- or closed-configuration unit, appears to be an accurate imaging technique to assess clinically relevant pelvic floor abnormalities. Moreover, MR defecography negates the need to expose the patient to harmful ionizing radiation and allows excellent depiction of the surrounding soft tissues of the pelvis. In this manuscript, we review the techniques and indications of MR defecography, and illustrate the MRI features of a vast array of morphologic and functional pelvic floor disorders, with emphasis on the posterior pelvic compartment (anorectum)

  2. Wetting of nonconserved residue-backbones: A feature indicative of aggregation associated regions of proteins.

    Science.gov (United States)

    Pradhan, Mohan R; Pal, Arumay; Hu, Zhongqiao; Kannan, Srinivasaraghavan; Chee Keong, Kwoh; Lane, David P; Verma, Chandra S

    2016-02-01

    Aggregation is an irreversible form of protein complexation and often toxic to cells. The process entails partial or major unfolding that is largely driven by hydration. We model the role of hydration in aggregation using "Dehydrons." "Dehydrons" are unsatisfied backbone hydrogen bonds in proteins that seek shielding from water molecules by associating with ligands or proteins. We find that the residues at aggregation interfaces have hydrated backbones, and in contrast to other forms of protein-protein interactions, are under less evolutionary pressure to be conserved. Combining evolutionary conservation of residues and extent of backbone hydration allows us to distinguish regions on proteins associated with aggregation (non-conserved dehydron-residues) from other interaction interfaces (conserved dehydron-residues). This novel feature can complement the existing strategies used to investigate protein aggregation/complexation. © 2015 Wiley Periodicals, Inc.

  3. Feature selection for anomaly–based network intrusion detection using cluster validity indices

    CSIR Research Space (South Africa)

    Naidoo, T

    2015-09-01

    Full Text Available for Anomaly–Based Network Intrusion Detection Using Cluster Validity Indices Tyrone Naidoo_, Jules–Raymond Tapamoy, Andre McDonald_ Modelling and Digital Science, Council for Scientific and Industrial Research, South Africa 1tnaidoo2@csir.co.za 3...

  4. Evaluation of Male Reproductive Features as Maturity Indices for Short-finned Squid (IIlex illecebrosus)

    OpenAIRE

    Coelho, M. L.; Mallet, M. D.; O'Dor, R. K.

    1985-01-01

    Various aspects of maturation in male IIlex illecebrosus were examined in an attempt to find evidence for a more realistic maturity scale than that currently in use. Simple indices, based on morphology of the hectocotylized arm, failed to provide satisfactory relationships, but the observed variation in hectocotylus measurements may provide useful insights into the population ecology of the species. The earlier maturation of males than females and the observed premature release of spermato...

  5. Characteristic features of optical absorption for Gd{sub 2}O{sub 3} and NiO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zatsepin, A. F.; Kuznetsova, Yu. A., E-mail: iu.a.kuznetsova@urfu.ru; Rychkov, V. N. [Ural Federal University (Russian Federation); Sokolov, V. I. [Ural Branch of Russian Academy of Science, Institute of Metal Physics (Russian Federation)

    2017-03-15

    The technical approach to determination of the structural and optical parameters of oxides with reduced dimensionality based on optical absorption measurements is described by example of gadolinium and nickel oxides. It was established that the temperature behavior of fundamental absorption edge for oxide nanoparticles is similar with the bulk materials with crystal structure. At the same time, the energy characteristics (band gap and effective phonon energies) for low-dimensional oxides are found to be significantly different from their bulk counterparts. The presented methodological method to obtain of qualitative and quantitative correlations of structural and optical characteristics provides novel reliable knowledge of nanoscaled 3d and 4f–metal oxide materials that is useful for development of their practical applications.

  6. Comparative Analysis of Vertebrate Dystrophin Loci Indicate Intron Gigantism as a Common Feature

    Science.gov (United States)

    Pozzoli, Uberto; Elgar, Greg; Cagliani, Rachele; Riva, Laura; Comi, Giacomo P.; Bresolin, Nereo; Bardoni, Alessandra; Sironi, Manuela

    2003-01-01

    The human DMD gene is the largest known to date, spanning > 2000 kb on the X chromosome. The gene size is mainly accounted for by huge intronic regions. We sequenced 190 kb of Fugu rubripes (pufferfish) genomic DNA corresponding to the complete dystrophin gene (FrDMD) and provide the first report of gene structure and sequence comparison among dystrophin genomic sequences from different vertebrate organisms. Almost all intron positions and phases are conserved between FrDMD and its mammalian counterparts, and the predicted protein product of the Fugu gene displays 55% identity and 71% similarity to human dystrophin. In analogy to the human gene, FrDMD presents several-fold longer than average intronic regions. Analysis of intron sequences of the human and murine genes revealed that they are extremely conserved in size and that a similar fraction of total intron length is represented by repetitive elements; moreover, our data indicate that intron expansion through repeat accumulation in the two orthologs is the result of independent insertional events. The hypothesis that intron length might be functionally relevant to the DMD gene regulation is proposed and substantiated by the finding that dystrophin intron gigantism is common to the three vertebrate genes. [Supplemental material is available online at www.genome.org.] PMID:12727896

  7. FEATURES IMMUNOLOGIC INDICATORS OF CHRONIC TONSILLITIS ASSOCIATED WITH EPSTEIN-BARR VIRUS IN ADULTS

    Directory of Open Access Journals (Sweden)

    Kuchma I.U

    2014-10-01

    Full Text Available Chronic tonsillitis are the most common diseases of the upper respiratory tract. One of the causes of tonsillitis, with severe clinical manifestations or erased is the Epstein - Barr virus (EBV. According to the literature, more than 90% of the adult population infected with EBV and are lifelong carriers of the virus. After primary infection replication of the virus in asymptomatic or in the case of a weakened immune system may develop infectious mononucleosis. Primary EBV infection in adolescence and adults is much greater than in children and often causes the formation of chronic forms. The main entrance gate is EBV oropharyngeal epithelium. In epithelial cells undergoing complete EBV replication with lysis of cells and the formation of a large number of virions. EBV infects B lymphocytes through the interaction of the surface gp320 virus with CD21 (receptor for complement component C3d. In EBV-infected B lymphocytes are two possible kinds of replication: lytic and latent process. During replication of EBV lytic expressed approximately 100 proteins are immunogenic but are 4 types of proteins, which have specific antibodies: early antigen - EA; viral capsid antigen - VCA; Epstein-Barr nuclear antigen - EBNA; latent membrane protein - LMP. LMP-1 induced bcl-2 (a blocker of apoptosis in B-cells and promotes proliferation and migration of B-lymphocytes. Thus, EBV infection is characterized by widespread, reactivation of infection from infected parts that most often manifests itself with recurrent infection with symptoms of chronic tonsillitis. Objective: what features of general and local immunological parameters inherent in chronic tonsillitis in the acute stage, caused by reactivation of EBV infection. Materials and methods. The study included 311 patients with chronic tonsillitis subcompensated in the acute stage. Microbiological testing of samples produced from the throat, determined EBV DNA in saliva, EVB-VCA-IgM, EVB-EA-IgG and EVB-NA-IgG in

  8. Digital soil mapping using remote sensing indices, terrain attributes, and vegetation features in the rangelands of northeastern Iran.

    Science.gov (United States)

    Mahmoudabadi, Ebrahim; Karimi, Alireza; Haghnia, Gholam Hosain; Sepehr, Adel

    2017-09-11

    Digital soil mapping has been introduced as a viable alternative to the traditional mapping methods due to being fast and cost-effective. The objective of the present study was to investigate the capability of the vegetation features and spectral indices as auxiliary variables in digital soil mapping models to predict soil properties. A region with an area of 1225 ha located in Bajgiran rangelands, Khorasan Razavi province, northeastern Iran, was chosen. A total of 137 sampling sites, each containing 3-5 plots with 10-m interval distance along a transect established based on randomized-systematic method, were investigated. In each plot, plant species names and numbers as well as vegetation cover percentage (VCP) were recorded, and finally one composite soil sample was taken from each transect at each site (137 soil samples in total). Terrain attributes were derived from a digital elevation model, different bands and spectral indices were obtained from the Landsat7 ETM+ images, and vegetation features were calculated in the plots, all of which were used as auxiliary variables to predict soil properties using artificial neural network, gene expression programming, and multivariate linear regression models. According to R 2 RMSE and MBE values, artificial neutral network was obtained as the most accurate soil properties prediction function used in scorpan model. Vegetation features and indices were more effective than remotely sensed data and terrain attributes in predicting soil properties including calcium carbonate equivalent, clay, bulk density, total nitrogen, carbon, sand, silt, and saturated moisture capacity. It was also shown that vegetation indices including NDVI, SAVI, MSAVI, SARVI, RDVI, and DVI were more effective in estimating the majority of soil properties compared to separate bands and even some soil spectral indices.

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

    Science.gov (United States)

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

    2014-03-28

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Zanatta, G.; Gottfried, C. [Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, 90035-003 Porto Alegre-RS (Brazil); Silva, A. M. [Universidade Estadual do Piauí, 64260-000 Piripiri-Pi (Brazil); Caetano, E. W. S., E-mail: ewcaetano@gmail.com [Instituto de Educação, Ciência e Tecnologia do Ceará, 60040-531 Fortaleza-CE (Brazil); Sales, F. A. M.; Freire, V. N. [Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, 60455-760 Fortaleza-CE (Brazil)

    2014-03-28

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

  11. Crowdsourcing Broad Absorption Line Properties and Other Features of Quasar Outflow Using Zooniverse Citizen Science Project Platform

    Science.gov (United States)

    Crowe, Cassie; Lundgren, Britt; Grier, Catherine

    2018-01-01

    The Sloan Digital Sky Survey (SDSS) regularly publishes vast catalogs of quasars and other astronomical objects. Previously, the SDSS collaboration has used visual inspection to check quasar redshift validity and flag instances of broad absorption lines (BALs). This information helps researchers to easily single out the quasars with BAL properties and study their outflows and other intervening gas clouds. Due to the ever-growing number of new SDSS quasar observations, visual inspections are no longer possible using previous methods. Currently, BAL information is being determined entirely computationally, and the accuracy of that information is not precisely known. This project uses the Zooniverse citizen science platform to visually inspect quasar spectra for BAL properties, to check the accuracy of the current autonomous methods, and to flag multi-phase outflows and find candidates for in-falling gas into the quasar central engine. The layout and format of a Zooniverse project provides an easier way to inspect and record data on each spectrum and share the workload via crowdsourcing. Work done by the SDSS collaboration members is serving as a beta test for a public project upon the official release of the DR14 quasar catalog by SDSS.

  12. D-xylose absorption

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003606.htm D-xylose absorption To use the sharing features on this page, please enable JavaScript. D-xylose absorption is a laboratory test to determine ...

  13. Emotional, behavioral, and developmental features indicative of neglect or emotional abuse in preschool children: a systematic review.

    Science.gov (United States)

    Naughton, Aideen Mary; Maguire, Sabine Ann; Mann, Mala Kanthi; Lumb, Rebecca Caroline; Tempest, Vanessa; Gracias, Shirley; Kemp, Alison Mary

    2013-08-01

    Early intervention for neglect or emotional abuse in preschoolers may mitigate lifelong consequences, yet practitioners lack confidence in recognizing these children. To define the emotional, behavioral, and developmental features of neglect or emotional abuse in preschoolers. A literature search of 18 databases, 6 websites, and supplementary searching performed from January 1, 1960, to February 1, 2011, identified 22 669 abstracts. Standardized critical appraisal of 164 articles was conducted by 2 independent, trained reviewers. Inclusion criteria were children aged 0 to 6 years with confirmed neglect or emotional abuse who had emotional, behavioral, and developmental features recorded or for whom the carer-child interaction was documented. Twenty-eight case-control (matched for socioeconomic, educational level, and ethnicity), 1 cross-sectional, and 13 cohort studies were included. Key features in the child included the following: aggression (11 studies) exhibited as angry, disruptive behavior, conduct problems, oppositional behavior, and low ego control; withdrawal or passivity (12 studies), including negative self-esteem, anxious or avoidant behavior, poor emotional knowledge, and difficulties in interpreting emotional expressions in others; developmental delay (17 studies), particularly delayed language, cognitive function, and overall development quotient; poor peer interaction (5 studies), showing poor social interactions, unlikely to act to relieve distress in others; and transition (6 studies) from ambivalent to avoidant insecure attachment pattern and from passive to increasingly aggressive behavior and negative self-representation. Emotional knowledge, cognitive function, and language deteriorate without intervention. Poor sensitivity, hostility, criticism, or disinterest characterize maternal-child interactions. Preschool children who have been neglected or emotionally abused exhibit a range of serious emotional and behavioral difficulties and adverse

  14. Expression of Immunoglobulin Receptors with Distinctive Features Indicating Antigen Selection by Marginal Zone B Cells from Human Spleen

    Science.gov (United States)

    Colombo, Monica; Cutrona, Giovanna; Reverberi, Daniele; Bruno, Silvia; Ghiotto, Fabio; Tenca, Claudya; Stamatopoulos, Kostas; Hadzidimitriou, Anastasia; Ceccarelli, Jenny; Salvi, Sandra; Boccardo, Simona; Calevo, Maria Grazia; De Santanna, Amleto; Truini, Mauro; Fais, Franco; Ferrarini, Manlio

    2013-01-01

    Marginal zone (MZ) B cells, identified as surface (s)IgMhighsIgDlowCD23low/−CD21+CD38− B cells, were purified from human spleens, and the features of their V(D)J gene rearrangements were investigated and compared with those of germinal center (GC), follicular mantle (FM) and switched memory (SM) B cells. Most MZ B cells were CD27+ and exhibited somatic hypermutations (SHM), although to a lower extent than SM B cells. Moreover, among MZ B-cell rearrangements, recurrent sequences were observed, some of which displayed intraclonal diversification. The same diversifying sequences were detected in very low numbers in GC and FM B cells and only when a highly sensitive, gene-specific polymerase chain reaction was used. This result indicates that MZ B cells could expand and diversify in situ and also suggested the presence of a number of activation-induced cytidine deaminase (AID)-expressing B cells in the MZ. The notion of antigen-driven expansion/selection in situ is further supported by the VH CDR3 features of MZ B cells with highly conserved amino acids at specific positions and by the finding of shared (“stereotyped”) sequences in two different spleens. Collectively, the data are consistent with the notion that MZ B cells are a special subset selected by in situ antigenic stimuli. PMID:23877718

  15. A hybrid feature selection and health indicator construction scheme for delay-time-based degradation modelling of rolling element bearings

    Science.gov (United States)

    Zhang, Bin; Deng, Congying; Zhang, Yi

    2018-03-01

    Rolling element bearings are mechanical components used frequently in most rotating machinery and they are also vulnerable links representing the main source of failures in such systems. Thus, health condition monitoring and fault diagnosis of rolling element bearings have long been studied to improve operational reliability and maintenance efficiency of rotatory machines. Over the past decade, prognosis that enables forewarning of failure and estimation of residual life attracted increasing attention. To accurately and efficiently predict failure of the rolling element bearing, the degradation requires to be well represented and modelled. For this purpose, degradation of the rolling element bearing is analysed with the delay-time-based model in this paper. Also, a hybrid feature selection and health indicator construction scheme is proposed for extraction of the bearing health relevant information from condition monitoring sensor data. Effectiveness of the presented approach is validated through case studies on rolling element bearing run-to-failure experiments.

  16. Influence of precipitation, landscape and hydrogeomorphic lake features on pelagic allochthonous indicators in two connected ultraoligotrophic lakes of North Patagonia

    International Nuclear Information System (INIS)

    Queimaliños, Claudia; Reissig, Mariana; Diéguez, María del Carmen; Arcagni, Marina; Ribeiro Guevara, Sergio; Campbell, Linda; Soto Cárdenas, Carolina; Rapacioli, Raúl

    2012-01-01

    We investigated the terrestrial influence on two chained deep ultraoligotrophic lakes of North Patagonia (Argentina) through the seasonal analysis of two pelagic allochthonous indicators: i) water color, as a proxy of allochthonous dissolved organic matter in lakes; and ii) the color to chlorophyll a ratio (Color:Chla), as an indicator of the relationship between allochthonous and autochthonous carbon pools. We also evaluated the potential transfer pathways of the allochthonous dissolved organic matter into the pelagic food webs of these deep lakes, including the natural zooplankton δ 13 C in the analysis. The dynamics of the allochthonous indicators were related to the precipitation regime, water level fluctuations, and hydrogeomorphic and catchment features of lakes Moreno East and Moreno West. The water color (absorbance at 440 nm) was extremely low ( −1 ) in both lakes regardless of the season. However, precipitation and snowmelt regimes drove the increase and decrease of water color, respectively. A significant positive relationship between the zooplankton bulk δ 13 C with the water color would suggest an input of allochthonous organic carbon into the pelagic consumers. The incorporation of the dissolved allochthonous material into higher trophic levels is likely favored by the bacterivorous behavior of planktonic organisms, mixotrophic flagellates and ciliates, which dominate the pelagic food webs of these Patagonian lakes. Morphometric aspects, mainly the higher water residence time, led to lower values of allochthony in Moreno East compared to Moreno West, probably accentuated by its upper position in the lake chain. Overall, our results suggest that these allochthonous signals can bring insight into the magnitude of the interaction between terrestrial environments and lake ecosystems, even in extremely clear and ultraoligotrophic systems, such as the Andean Patagonian lakes. - Highlights: ► Pelagic allochthonous indicators were detected in two

  17. Influence of precipitation, landscape and hydrogeomorphic lake features on pelagic allochthonous indicators in two connected ultraoligotrophic lakes of North Patagonia

    Energy Technology Data Exchange (ETDEWEB)

    Queimalinos, Claudia, E-mail: queimalinosc@comahue-conicet.gob.ar [Laboratorio de Fotobiologia, Instituto de Investigaciones en Biodiversidad y Medio Ambiente (INIBIOMA, UNComahue-CONICET), Quintral 1250, R8400FRF Bariloche, Rio Negro (Argentina); Reissig, Mariana; Dieguez, Maria del Carmen [Laboratorio de Fotobiologia, Instituto de Investigaciones en Biodiversidad y Medio Ambiente (INIBIOMA, UNComahue-CONICET), Quintral 1250, R8400FRF Bariloche, Rio Negro (Argentina); Arcagni, Marina; Ribeiro Guevara, Sergio [Laboratorio de Analisis por Activacion Neutronica (LAAN), Centro Atomico Bariloche, Comision Nacional de Energia Atomica, Av. Bustillo 9500, R8402AGP Bariloche, Rio Negro (Argentina); Campbell, Linda [School of Environmental Studies, Saint Mary' s University, 923 Robie Street, Halifax, Nova Scotia, Canada B3H-3C3 (Canada); Soto Cardenas, Carolina [Laboratorio de Fotobiologia, Instituto de Investigaciones en Biodiversidad y Medio Ambiente (INIBIOMA, UNComahue-CONICET), Quintral 1250, R8400FRF Bariloche, Rio Negro (Argentina); Rapacioli, Raul [Facultad de Ingenieria, Universidad Nacional del Comahue, Buenos Aires1400, Q8300IBX Neuquen (Argentina); and others

    2012-06-15

    We investigated the terrestrial influence on two chained deep ultraoligotrophic lakes of North Patagonia (Argentina) through the seasonal analysis of two pelagic allochthonous indicators: i) water color, as a proxy of allochthonous dissolved organic matter in lakes; and ii) the color to chlorophyll a ratio (Color:Chla), as an indicator of the relationship between allochthonous and autochthonous carbon pools. We also evaluated the potential transfer pathways of the allochthonous dissolved organic matter into the pelagic food webs of these deep lakes, including the natural zooplankton {delta}{sup 13}C in the analysis. The dynamics of the allochthonous indicators were related to the precipitation regime, water level fluctuations, and hydrogeomorphic and catchment features of lakes Moreno East and Moreno West. The water color (absorbance at 440 nm) was extremely low (< 0.28 m{sup -1}) in both lakes regardless of the season. However, precipitation and snowmelt regimes drove the increase and decrease of water color, respectively. A significant positive relationship between the zooplankton bulk {delta}{sup 13}C with the water color would suggest an input of allochthonous organic carbon into the pelagic consumers. The incorporation of the dissolved allochthonous material into higher trophic levels is likely favored by the bacterivorous behavior of planktonic organisms, mixotrophic flagellates and ciliates, which dominate the pelagic food webs of these Patagonian lakes. Morphometric aspects, mainly the higher water residence time, led to lower values of allochthony in Moreno East compared to Moreno West, probably accentuated by its upper position in the lake chain. Overall, our results suggest that these allochthonous signals can bring insight into the magnitude of the interaction between terrestrial environments and lake ecosystems, even in extremely clear and ultraoligotrophic systems, such as the Andean Patagonian lakes. - Highlights: Black-Right-Pointing-Pointer Pelagic

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

    International Nuclear Information System (INIS)

    Van Dokkum, Pieter G.; Conroy, Charlie

    2011-01-01

    We recently found that massive cluster elliptical galaxies have strong Na I λ8183, 8195 and FeH λ9916 Wing-Ford band absorption, indicating the presence of a very large population of stars with masses ∼ sun . Here we test this result by comparing the elliptical galaxy spectra to those of luminous globular clusters associated with M31. These globular clusters have similar metallicities, abundance ratios, and ages as massive elliptical galaxies but their low dynamical mass-to-light ratios rule out steep stellar initial mass functions (IMFs). From high-quality Keck spectra we find that the dwarf-sensitive absorption lines in globular clusters are significantly weaker than in elliptical galaxies and consistent with normal IMFs. The differences in the Na I and Wing-Ford indices are 0.027 ± 0.007 mag and 0.017 ± 0.006 mag, respectively. We directly compare the two classes of objects by subtracting the averaged globular cluster spectrum from the averaged elliptical galaxy spectrum. The difference spectrum is well fit by the difference between a stellar population synthesis model with a bottom-heavy IMF and one with a bottom-light IMF. We speculate that the slope of the IMF may vary with velocity dispersion, although it is not yet clear what physical mechanism would be responsible for such a relation.

  19. Synthesis temperature effect on the structural features and optical absorption of Zn(1-x)Co(x)Al2O4 oxides.

    Science.gov (United States)

    Gaudon, M; Apheceixborde, A; Ménétrier, M; Le Nestour, A; Demourgues, A

    2009-10-05

    Zinc/cobalt aluminates with spinel-type structure were prepared by a polymeric route, leading to a pure phase with controlled grain size. The prepared pigments were characterized by powder X-ray diffraction Rietveld analyses in order to determine structural features, scanning electron microscopy for morphological investigation, helium pycnometry and (27)Al MAS NMR in order to highlight the occurrence of defects inside the structure, and UV-visible-near-IR spectroscopy to identify electronic transitions responsible for the compounds' color. The green-blue coloration of these pigments is known to be dependent on the sample thermal history. Here, for the first time, the Zn(1-x)Co(x)Al(2)O(4) color is newly interpreted. The pigment is green once synthesized at low temperature (i.e., with diminution of the pigment grain size); this variation was attributed to the appearance of a new absorption band located at about 500 nm, linked to a complex network feature involving Co ions in octahedral sites as well as oxygen and cationic vacancies. Hence, this work shows the possibility of easily getting a nonstoichiometric network with an abnormal cationic distribution from "chimie douce" processes with moderate synthesis temperature, and so various colorations for the same composition.

  20. Direct estimates of natural selection in Iberia indicate calcium absorption was not the only driver of lactase persistence in Europe.

    Science.gov (United States)

    Sverrisdóttir, Oddny Ósk; Timpson, Adrian; Toombs, Jamie; Lecoeur, Cecile; Froguel, Philippe; Carretero, Jose Miguel; Arsuaga Ferreras, Juan Luis; Götherström, Anders; Thomas, Mark G

    2014-04-01

    Lactase persistence (LP) is a genetically determined trait whereby the enzyme lactase is expressed throughout adult life. Lactase is necessary for the digestion of lactose--the main carbohydrate in milk--and its production is downregulated after the weaning period in most humans and all other mammals studied. Several sources of evidence indicate that LP has evolved independently, in different parts of the world over the last 10,000 years, and has been subject to strong natural selection in dairying populations. In Europeans, LP is strongly associated with, and probably caused by, a single C to T mutation 13,910 bp upstream of the lactase (LCT) gene (-13,910*T). Despite a considerable body of research, the reasons why LP should provide such a strong selective advantage remain poorly understood. In this study, we examine one of the most widely cited hypotheses for selection on LP--that fresh milk consumption supplemented the poor vitamin D and calcium status of northern Europe's early farmers (the calcium assimilation hypothesis). We do this by testing for natural selection on -13,910*T using ancient DNA data from the skeletal remains of eight late Neolithic Iberian individuals, whom we would not expect to have poor vitamin D and calcium status because of relatively high incident UVB light levels. None of the eight samples successfully typed in the study had the derived T-allele. In addition, we reanalyze published data from French Neolithic remains to both test for population continuity and further examine the evolution of LP in the region. Using simulations that accommodate genetic drift, natural selection, uncertainty in calibrated radiocarbon dates, and sampling error, we find that natural selection is still required to explain the observed increase in allele frequency. We conclude that the calcium assimilation hypothesis is insufficient to explain the spread of LP in Europe.

  1. Evaluating the Nature of So-Called S*-State Feature in Transient Absorption of Carotenoids in Light-Harvesting Complex 2 (LH2) from Purple Photosynthetic Bacteria.

    Science.gov (United States)

    Niedzwiedzki, Dariusz M; Hunter, C Neil; Blankenship, Robert E

    2016-11-03

    Carotenoids are a class of natural pigments present in all phototrophic organisms, mainly in their light-harvesting proteins in which they play roles of accessory light absorbers and photoprotectors. Extensive time-resolved spectroscopic studies of these pigments have revealed unexpectedly complex photophysical properties, particularly for carotenoids in light-harvesting LH2 complexes from purple bacteria. An ambiguous, optically forbidden electronic excited state designated as S* has been postulated to be involved in carotenoid excitation relaxation and in an alternative carotenoid-to-bacteriochlorophyll energy transfer pathway, as well as being a precursor of the carotenoid triplet state. However, no definitive and satisfactory origin of the carotenoid S* state in these complexes has been established, despite a wide-ranging series of studies. Here, we resolve the ambiguous origin of the carotenoid S* state in LH2 complex from Rba. sphaeroides by showing that the S* feature can be seen as a combination of ground state absorption bleaching of the carotenoid pool converted to cations and the Stark spectrum of neighbor neutral carotenoids, induced by temporal electric field brought by the carotenoid cation-bacteriochlorophyll anion pair. These findings remove the need to assign an S* state, and thereby significantly simplify the photochemistry of carotenoids in these photosynthetic antenna complexes.

  2. STAR CLUSTERS IN M31. IV. A COMPARATIVE ANALYSIS OF ABSORPTION LINE INDICES IN OLD M31 AND MILKY WAY CLUSTERS

    International Nuclear Information System (INIS)

    Schiavon, Ricardo P.; Caldwell, Nelson; Morrison, Heather; Harding, Paul; Courteau, Stéphane; MacArthur, Lauren A.; Graves, Genevieve J.

    2012-01-01

    We present absorption line indices measured in the integrated spectra of globular clusters both from the Galaxy and from M31. Our samples include 41 Galactic globular clusters, and more than 300 clusters in M31. The conversion of instrumental equivalent widths into the Lick system is described, and zero-point uncertainties are provided. Comparison of line indices of old M31 clusters and Galactic globular clusters suggests an absence of important differences in chemical composition between the two cluster systems. In particular, CN indices in the spectra of M31 and Galactic clusters are essentially consistent with each other, in disagreement with several previous works. We reanalyze some of the previous data, and conclude that reported CN differences between M31 and Galactic clusters were mostly due to data calibration uncertainties. Our data support the conclusion that the chemical compositions of Milky Way and M31 globular clusters are not substantially different, and that there is no need to resort to enhanced nitrogen abundances to account for the optical spectra of M31 globular clusters.

  3. STAR CLUSTERS IN M31. IV. A COMPARATIVE ANALYSIS OF ABSORPTION LINE INDICES IN OLD M31 AND MILKY WAY CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Schiavon, Ricardo P. [Gemini Observatory, Hilo, HI 96720 (United States); Caldwell, Nelson [Smithsonian Astrophysical Observatory, Cambridge, MA 02138 (United States); Morrison, Heather; Harding, Paul [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106-7215 (United States); Courteau, Stephane [Department of Physics, Engineering Physics and Astronomy, Queen' s University, Kingston, ON K7L 3N6 (Canada); MacArthur, Lauren A. [Herzberg Institute of Astrophysics, National Research Council of Canada/University of Victoria, Victoria, B.C. V9E 2E7 (Canada); Graves, Genevieve J., E-mail: rschiavon@gemini.edu, E-mail: caldwell@cfa.harvard.edu, E-mail: paul.harding@case.edu, E-mail: heather@vegemite.case.edu, E-mail: courteau@astro.queensu.ca, E-mail: Lauren.MacArthur@nrc-cnrc.gc.ca, E-mail: graves@astro.berkeley.edu [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2012-01-15

    We present absorption line indices measured in the integrated spectra of globular clusters both from the Galaxy and from M31. Our samples include 41 Galactic globular clusters, and more than 300 clusters in M31. The conversion of instrumental equivalent widths into the Lick system is described, and zero-point uncertainties are provided. Comparison of line indices of old M31 clusters and Galactic globular clusters suggests an absence of important differences in chemical composition between the two cluster systems. In particular, CN indices in the spectra of M31 and Galactic clusters are essentially consistent with each other, in disagreement with several previous works. We reanalyze some of the previous data, and conclude that reported CN differences between M31 and Galactic clusters were mostly due to data calibration uncertainties. Our data support the conclusion that the chemical compositions of Milky Way and M31 globular clusters are not substantially different, and that there is no need to resort to enhanced nitrogen abundances to account for the optical spectra of M31 globular clusters.

  4. Nonlinear smooth orthogonal decomposition of kinematic features of sawing reconstructs muscle fatigue evolution as indicated by electromyography.

    Science.gov (United States)

    Segala, David B; Gates, Deanna H; Dingwell, Jonathan B; Chelidze, David

    2011-03-01

    Tracking or predicting physiological fatigue is important for developing more robust training protocols and better energy supplements and/or reducing muscle injuries. Current methodologies are usually impractical and/or invasive and may not be realizable outside of laboratory settings. It was recently demonstrated that smooth orthogonal decomposition (SOD) of phase space warping (PSW) features of motion kinematics can identify fatigue in individual muscle groups. We hypothesize that a nonlinear extension of SOD will identify more optimal fatigue coordinates and provide a lower-dimensional reconstruction of local fatigue dynamics than the linear SOD. Both linear and nonlinear SODs were applied to PSW features estimated from measured kinematics to reconstruct muscle fatigue dynamics in subjects performing a sawing motion. Ten healthy young right-handed subjects pushed a weighted handle back and forth until voluntary exhaustion. Three sets of joint kinematic angles were measured from the right upper extremity in addition to surface electromyography (EMG) recordings. The SOD coordinates of kinematic PSW features were compared against independently measured fatigue markers (i.e., mean and median EMG spectrum frequencies of individual muscle groups). This comparison was based on a least-squares linear fit of a fixed number of the dominant SOD coordinates to the appropriate local fatigue markers. Between subject variability showed that at most four to five nonlinear SOD coordinates were needed to reconstruct fatigue in local muscle groups, while on average 15 coordinates were needed for the linear SOD. Thus, the nonlinear coordinates provided a one-order-of-magnitude improvement over the linear ones.

  5. Aberrant proteins featured in the saliva of habitual betel quid chewers: an indication of early oral premalignancy?

    Science.gov (United States)

    Jessie, Kala; Jayapalan, Jaime Jacqueline; Rahim, Zubaidah Haji Abdul; Hashim, Onn Haji

    2014-12-01

    Prolonged chewing of betel quid is known to cause oral diseases, including cancer. The present study was performed to screen for aberrant proteins in the saliva of habitual betel quid chewers compared to nonchewers. Saliva of female subjects (n = 10) who had been chewing betel quid for more than 20 years and nonbetel quid chewers (n = 10) of the same gender and range of age was analyzed by gel-based proteomics. Increased structural microheterogeneity of saliva haptoglobin beta chains indicated by shifts of focused spots similar to that earlier reported in patients with oral squamous cell carcinoma, and their relatively higher abundance compared to nonbetel quid chewers, were detected in saliva protein profiles of all chewers. In addition, the majority of the betel quid chewers also showed significant higher abundance of hemopexin, alpha-1B glycoprotein, alpha1-antitrypsin, complement C3, and transthyretin. These proteins had previously been associated with several different cancers. Our data demonstrated different forms of protein aberration in the saliva of betel quid chewers, which may be indicative of early oral precancerous conditions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. MRI characterization of temporal lobe epilepsy using rapidly measurable spatial indices with hemisphere asymmetries and gender features

    International Nuclear Information System (INIS)

    Datta, Siddhartha; Chakrabarti, Nilkanta; Sarkar, Sudipta; Chakraborty, Sumit; Basu, Swadhapriya; Mulpuru, Sai Krishna; Tiwary, Basant K.; Roy, Prasun Kumar

    2015-01-01

    The paucity of morphometric markers for hemispheric asymmetries and gender variations in hippocampi and amygdalae in temporal lobe epilepsy (TLE) calls for better characterization of TLE by finding more useful prognostic MRI parameter(s). T1-weighted MRI (3 T) morphometry using multiple parameters of hippocampus-parahippocampus (angular and linear measures, volumetry) and amygdalae (volumetry) including their hemispheric asymmetry indices (AI) were evaluated in both genders. The cutoff values of parameters were statistically estimated from measurements of healthy subjects to characterize TLE (57 patients, 55 % male) alterations. TLE had differential categories with hippocampal atrophy, parahippocampal angle (PHA) acuteness, and several other parametric changes. Bilateral TLE categories were much more prevalent compared to unilateral TLE categories. Female patients were considerably more disposed to bilateral TLE categories than male patients. Male patients displayed diverse categories of unilateral abnormalities. Few patients (both genders) had combined bilateral appearances of hippocampal atrophy, amygdala atrophy, PHA acuteness, and increase in hippocampal angle (HA) where medial distance ratio (MDR) varied among genders. TLE had gender-specific and hemispheric dominant alterations in AI of parameters. Maximum magnitude of parametric changes in TLE includes (a) AI increase in HA of both genders, (b) HA increase (bilateral) in female patients, and (c) increase in ratio of amygdale/hippocampal volume (unilateral, right hemispheric), and AI decrease in MDR, in male patients. Multiparametric MRI studies of hippocampus and amygdalae, including their hemispheric asymmetry, underscore better characterization of TLE. Rapidly measurable single-slice parameters (HA, PHA, MDR) can readily delineate TLE in a time-constrained clinical setting, which contrasts with customary three-dimensional hippocampal volumetry that requires many slice computation. (orig.)

  7. MRI characterization of temporal lobe epilepsy using rapidly measurable spatial indices with hemisphere asymmetries and gender features

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Siddhartha; Chakrabarti, Nilkanta [University of Calcutta, Department of Physiology and UGC-CPEPA Centre for ' ' Electro-physiological and Neuro-imaging studies including Mathematical Modelling' ' , Kolkata (India); Sarkar, Sudipta; Chakraborty, Sumit; Basu, Swadhapriya [IPGME and R, SSKM Hospital, Department of Radiodiagnosis, Kolkata (India); Mulpuru, Sai Krishna [National Brain Research Centre, National Neuro-Imaging Facility, Manesar (India); Tiwary, Basant K. [Pondicherry University, Centre for Bioinformatics, School of Life Sciences, Pondicherry (India); Roy, Prasun Kumar [National Brain Research Centre, Computational Neuroimaging Division, Manesar (India); National Brain Research Centre, Clinical Neuroscience Unit, Gurgaon (India)

    2015-09-15

    The paucity of morphometric markers for hemispheric asymmetries and gender variations in hippocampi and amygdalae in temporal lobe epilepsy (TLE) calls for better characterization of TLE by finding more useful prognostic MRI parameter(s). T1-weighted MRI (3 T) morphometry using multiple parameters of hippocampus-parahippocampus (angular and linear measures, volumetry) and amygdalae (volumetry) including their hemispheric asymmetry indices (AI) were evaluated in both genders. The cutoff values of parameters were statistically estimated from measurements of healthy subjects to characterize TLE (57 patients, 55 % male) alterations. TLE had differential categories with hippocampal atrophy, parahippocampal angle (PHA) acuteness, and several other parametric changes. Bilateral TLE categories were much more prevalent compared to unilateral TLE categories. Female patients were considerably more disposed to bilateral TLE categories than male patients. Male patients displayed diverse categories of unilateral abnormalities. Few patients (both genders) had combined bilateral appearances of hippocampal atrophy, amygdala atrophy, PHA acuteness, and increase in hippocampal angle (HA) where medial distance ratio (MDR) varied among genders. TLE had gender-specific and hemispheric dominant alterations in AI of parameters. Maximum magnitude of parametric changes in TLE includes (a) AI increase in HA of both genders, (b) HA increase (bilateral) in female patients, and (c) increase in ratio of amygdale/hippocampal volume (unilateral, right hemispheric), and AI decrease in MDR, in male patients. Multiparametric MRI studies of hippocampus and amygdalae, including their hemispheric asymmetry, underscore better characterization of TLE. Rapidly measurable single-slice parameters (HA, PHA, MDR) can readily delineate TLE in a time-constrained clinical setting, which contrasts with customary three-dimensional hippocampal volumetry that requires many slice computation. (orig.)

  8. Iris colour as an indicator of age feature in female Brazilian tanagers (Passeriformes: Emberizidae confirmed by a molecular sexing technique

    Directory of Open Access Journals (Sweden)

    Denise Monnerat Nogueira

    2008-12-01

    Full Text Available The Brazilian tanager, Ramphocelus bresilius is an endemic species from Brazil that is sexually dimorphic in adult plumage. Young males are similar to adult and young females until their second year. Adults and young females are not distinguishable in plumage. We tested whether iris colour can be used to separate adult females from immature females. We used for the first time the molecular sexing technique based on CHD-genes to confirm the sex of the individuals classified as "female plumage with red iris", and to identify the sex of individuals classified as "female plumage and brown iris". The adult males were used as a positive control. DNA samples from 190 individuals were analysed. The sizes of the PCR products were identified as 350 base pairs (bp for CHD-Z and 388 bp for CHD-W. We confirmed that adult females have a red iris and the young females a brown iris. We could also separate young males and females which present the same iris colour and plumage. Although there are indications that the iris colour can be used by birds to identify the adults in co-operative breeding species such as the Brazilian tanager, more behavioural data are required to understand the role of iris coloration in this species. Rev. Biol. Trop. 56 (4: 1629-1633. Epub 2008 December 12.El ave Ramphocelus bresilius es una especie endémica de Brasil con dimorfismo sexual en el plumaje del adulto. Los machos jóvenes son similares a las hembras adultas y jóvenes hasta el segundo año de vida. Adultos y hembras jóvenes son indistinguibles por el plumaje. Evaluamos si el color del iris puede ser utilizado para distinguir hembras adultas de hembras inmaduras. Utilizamos por primera vez la técnica molecular de identificación de sexos basada en los genes CHD para confirmar el género de individuos clasificados como plumaje femenino con iris rojo, y para identificar el sexo de los individuos clasificados como plumaje femenino e iris marrón. Usamos machos adultos como

  9. Using High Resolution Commercial Satellite Imagery to Quantify Spatial Features of Urban Areas and their Relationship to Quality of Life Indicators in Accra, Ghana

    Science.gov (United States)

    Sandborn, A.; Engstrom, R.; Yu, Q.

    2014-12-01

    Mapping urban areas via satellite imagery is an important task for detecting and anticipating land cover and land use change at multiple scales. As developing countries experience substantial urban growth and expansion, remotely sensed based estimates of population and quality of life indicators can provide timely and spatially explicit information to researchers and planners working to determine how cities are changing. In this study, we use commercial high spatial resolution satellite imagery in combination with fine resolution census data to determine the ability of using remotely sensed data to reveal the spatial patterns of quality of life in Accra, Ghana. Traditionally, spectral characteristics are used on a per-pixel basis to determine land cover; however, in this study, we test a new methodology that quantifies spatial characteristics using a variety of spatial features observed in the imagery to determine the properties of an urban area. The spatial characteristics used in this study include histograms of oriented gradients, PanTex, Fourier transform, and line support regions. These spatial features focus on extracting structural and textural patterns of built-up areas, such as homogeneous building orientations and straight line indices. Information derived from aggregating the descriptive statistics of the spatial features at both the fine-resolution census unit and the larger neighborhood level are then compared to census derived quality of life indicators including information about housing, education, and population estimates. Preliminary results indicate that there are correlations between straight line indices and census data including available electricity and literacy rates. Results from this study will be used to determine if this methodology provides a new and improved way to measure a city structure in developing cities and differentiate between residential and commercial land use zones, as well as formal versus informal housing areas.

  10. Calcium absorption and achlorhydria

    International Nuclear Information System (INIS)

    Recker, R.R.

    1985-01-01

    Defective absorption of calcium has been thought to exist in patients with achlorhydria. The author compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects. Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier. Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001). Fractional calcium absorption in the normal subjects was 0.243 +/- 0.049 for citrate and 0.225 +/- 0.108 for carbonate (not significant). Absorption of calcium from carbonate in patients with achlorhydria was significantly lower than in the normal subjects and was lower than absorption from citrate in either group; absorption from citrate in those with achlorhydria was significantly higher than in the normal subjects, as well as higher than absorption from carbonate in either group. Administration of calcium carbonate as part of a normal breakfast resulted in completely normal absorption in the achlorhydric subjects. These results indicate that calcium absorption from carbonate is impaired in achlorhydria under fasting conditions. Since achlorhydria is common in older persons, calcium carbonate may not be the ideal dietary supplement

  11. Self-organizing feature map (neural networks) as a tool to select the best indicator of road traffic pollution (soil, leaves or bark of Robinia pseudoacacia L.).

    Science.gov (United States)

    Samecka-Cymerman, A; Stankiewicz, A; Kolon, K; Kempers, A J

    2009-07-01

    Concentrations of the elements Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were measured in the leaves and bark of Robinia pseudoacacia and the soil in which it grew, in the town of Oleśnica (SW Poland) and at a control site. We selected this town because emission from motor vehicles is practically the only source of air pollution, and it seemed interesting to evaluate its influence on soil and plants. The self-organizing feature map (SOFM) yielded distinct groups of soils and R. pseudoacacia leaves and bark, depending on traffic intensity. Only the map classifying bark samples identified an additional group of highly polluted sites along the main highway from Wrocław to Warszawa. The bark of R. pseudoacacia seems to be a better bioindicator of long-term cumulative traffic pollution in the investigated area, while leaves are good indicators of short-term seasonal accumulation trends.

  12. Calcium absorption

    International Nuclear Information System (INIS)

    Carlmark, B.; Reizenstein, P.; Dudley, R.A.

    1976-01-01

    The methods most commonly used to measure the absorption and retention of orally administered calcium are reviewed. Nearly all make use of calcium radioisotopes. The magnitude of calcium absorption and retention depends upon the chemical form and amount of calcium administered, and the clinical and nutritional status of the subject; these influences are briefly surveyed. (author)

  13. Absorption studies

    International Nuclear Information System (INIS)

    Ganatra, R.D.

    1992-01-01

    Absorption studies were once quite popular but hardly anyone does them these days. It is easier to estimate the blood level of the nutrient directly by radioimmunoassay (RIA). However, the information obtained by estimating the blood levels of the nutrients is not the same that can be obtained from the absorption studies. Absorption studies are primarily done to find out whether some of the essential nutrients are absorbed from the gut or not and if they are absorbed, to determine how much is being absorbed. In the advanced countries, these tests were mostly done to detect pernicious anaemia where vitamin B 12 is not absorbed because of the lack of the intrinsic factor in the stomach. In the tropical countries, ''malabsorption syndrome'' is quire common. In this condition, several nutrients like fat, folic acid and vitamin B 12 are not absorbed. It is possible to study absorption of these nutrients by radioisotopic absorption studies

  14. Neuro-fuzzy inference system Prediction of stability indices and Sodium absorption ratio in Lordegan rural drinking water resources in west Iran.

    Science.gov (United States)

    Takdastan, Afshin; Mirzabeygi Radfard, Majid; Yousefi, Mahmood; Abbasnia, Abbas; Khodadadia, Rouhollah; Soleimani, Hamed; Mahvi, Amir Hossein; Naghan, Davood Jalili

    2018-06-01

    According to World Health Organization guidelines, corrosion control is an important aspect of safe drinking-water supplies. Water always includes ingredients, dissolved gases and suspended materials. Although some of these water ingredients is indispensable for human beings, these elements more than permissible limits, could be endanger human health. The aim of this study is to assess physical and chemical parameters of drinking water in the rural areas of Lordegan city, also to determine corrosion indices. This cross-sectional study has carried out with 141 taken samples during 2017 with 13 parameters, which has been analyzed based on standard method and to estimate the water quality indices from groundwater using ANFIS. Also with regard to standard conditions, results of this paper are compared with Environmental Protection Agency and Iran national standards. Five indices, Ryznar Stability Index (RSI), Langlier Saturation Index (LSI), Larson-Skold Index (LS), Puckorius Scaling Index (PSI), and Aggressive Index (AI) programmed by using Microsoft Excel software. Owing to its simplicity, the program, can easily be used by researchers and operators. Parameters included Sulfate, Sodium, Chloride, and Electrical Conductivity respectively were 13.5, 28, 10.5, and 15% more than standard level. The amount of Nitrate, in 98% of cases were in permissible limits and about 2% were more than standard level. Result of presented research indicate that water is corrosive at 10.6%,89.4%,87.2%,59.6% and 14.9% of drinking water supply reservoirs, according to LSI, RSI, PSI, LS and AI, respectively.

  15. Neutron resonance absorption theory

    International Nuclear Information System (INIS)

    Reuss, P.

    1991-11-01

    After some recalls on the physics of neutron resonance absorption during their slowing down, this paper presents the main features of the theoretical developments performed by the french school of reactor physics: the effective reaction rate method so called Livolant-Jeanpierre theory, the generalizations carried out by the author, and the probability table method [fr

  16. Folate absorption

    International Nuclear Information System (INIS)

    Baker, S.J.

    1976-01-01

    Folate is the generic term given to numerous compounds of pteroic acid with glutamic acid. Knowledge of absorption is limited because of the complexities introduced by the variety of compounds and because of the inadequacy of investigational methods. Two assay methods are in use, namely microbiological and radioactive. Techniques used to study absorption include measurement of urinary excretion, serum concentration, faecal excretion, intestinal perfusion, and haematological response. It is probably necessary to test absorption of both pteroylmonoglutamic acid and one or more polyglutamates, and such tests would be facilitated by availability of synthesized compounds labelled with radioactive tracers at specifically selected sites. (author)

  17. Investigating Seed Germination Indices and Absorption Rate of Sodium, Chloride, Calcium, and Potassium in Different Parts of Seedlings of Sweet Corn KSC 403 (Zea Mays L var. Saccharata Under Salinity Stress and Seed Priming

    Directory of Open Access Journals (Sweden)

    M. Nasrolah alhossini,

    2014-02-01

    Full Text Available To investigate the effects of different levels of seed priming on germination indices and nutrient absorption at early growth stages of sweet corn (Golden Kernel Hybrid a factorial experiment based on completely randomized design was conducted with three replications in 2011. The experiment consists of 6 levels of primings (seeds without priming, priming with tap water, priming with distilled water, priming with sodium chloride, potassium chloride, and hydrous calcium chloride and five levels of salinity (zero, 4, 8, 12 and 16 ds/m sodium chloride. The characteristics studied were germination percentage, germination rate, root and shoot length, fresh weight and dry weight of seedling, root to shoot ratio and determination of sodium, chloride, calcium, and potassium concentration in different parts of seedlings (stems, roots and seed. The results indicated that increasing salinity stress levels decreased all parameters measured. Priming seeds with hydrated calcium chloride responded to significantly to salinity stress better than other treatments. Results also showed that increasing concentration of sodium chloride salt, increased absorption rate of sodium but concentration of calcium and potassium were reduced. Because application of hydrous calcium chloride stimulates cell in using calcium under salinity conditions it leads to improved seedling growth parameters. To achieve a more accurate results slicing interaction effect of seed priming×salinity levels was performed. Hydrous calcium chloride treatments improved all traits under study except sodium and potassium concentration. This represents a better performance of seeds germination under salinity stress when seeds primed with hydrous calcium chloride.

  18. Self-organizing feature map (neural networks) as a tool to select the best indicator of road traffic pollution (soil, leaves or bark of Robinia pseudoacacia L.)

    Energy Technology Data Exchange (ETDEWEB)

    Samecka-Cymerman, A., E-mail: sameckaa@biol.uni.wroc.p [Department of Ecology, Biogeochemistry and Environmental Protection, Wroclaw University, ul. Kanonia 6/8, 50-328 Wroclaw (Poland); Stankiewicz, A.; Kolon, K. [Department of Ecology, Biogeochemistry and Environmental Protection, Wroclaw University, ul. Kanonia 6/8, 50-328 Wroclaw (Poland); Kempers, A.J. [Department of Environmental Sciences, Radboud University of Nijmegen, Toernooiveld, 6525 ED Nijmegen (Netherlands)

    2009-07-15

    Concentrations of the elements Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were measured in the leaves and bark of Robinia pseudoacacia and the soil in which it grew, in the town of Olesnica (SW Poland) and at a control site. We selected this town because emission from motor vehicles is practically the only source of air pollution, and it seemed interesting to evaluate its influence on soil and plants. The self-organizing feature map (SOFM) yielded distinct groups of soils and R. pseudoacacia leaves and bark, depending on traffic intensity. Only the map classifying bark samples identified an additional group of highly polluted sites along the main highway from Wroclaw to Warszawa. The bark of R. pseudoacacia seems to be a better bioindicator of long-term cumulative traffic pollution in the investigated area, while leaves are good indicators of short-term seasonal accumulation trends. - Once trained, SOFM could be used in the future to recognize types of pollution.

  19. Glazed ceramic roof tiles: influence of surface features in the solar reflectance index; Influencia das caracteristicas da superficie no indice de refletancia solar de telhas ceramicas esmaltadas

    Energy Technology Data Exchange (ETDEWEB)

    Bortoli, Leitcia Silva de; Stapait, Camila Cristina; Marinoski, Deivis Luis; Fredel, Marcio Celso; Schabbach, Luciana M., E-mail: luciana.maccarini@ufsc.br [Universidade Federal de Santa Catarina (UFSC), Blumenau, SC (Brazil)

    2016-07-01

    In this study the influence of surface features of ceramic roof tiles in the solar reflectance index were evaluated. Two glazed ceramic roof tiles (type stoneware) with the same color (ivory) but with different appearance (matte and brilliant) were the focus of the analysis. The Solar Reflectance Index (SRI) of the roofs tiles were determined by the solar reflectance values (UV-VIS-NIR) and emittance, measured in laboratory. The samples showed SRI> 39 in accordance with LEED certification criteria (Leadership in Energy and Environmental Design), contributing to minimizing the Heat Island Effects. Although the matte roof tile shows a slightly higher SRI value (82) than the brilliant one (78), the results for the variables that composes the SRI value (reflectance and emittance) were very similar. Analysis of XRD, SEM and EDS performed on the surfaces of the two roofs indicated for the matte glaze the presence of microcrystals (with barium and zinc) that can contribute to the slightly highest value of SRI. The roughness (optical interferometer white light) and the brightness (brightness meter) of the samples were also measured. (author)

  20. Narrative absorption

    DEFF Research Database (Denmark)

    Narrative Absorption brings together research from the social sciences and Humanities to solve a number of mysteries: Most of us will have had those moments, of being totally absorbed in a book, a movie, or computer game. Typically we do not have any idea about how we ended up in such a state. No...

  1. Rapidly variable relatvistic absorption

    Science.gov (United States)

    Parker, M.; Pinto, C.; Fabian, A.; Lohfink, A.; Buisson, D.; Alston, W.; Jiang, J.

    2017-10-01

    I will present results from the 1.5Ms XMM-Newton observing campaign on the most X-ray variable AGN, IRAS 13224-3809. We find a series of nine absorption lines with a velocity of 0.24c from an ultra-fast outflow. For the first time, we are able to see extremely rapid variability of the UFO features, and can link this to the X-ray variability from the inner accretion disk. We find a clear flux dependence of the outflow features, suggesting that the wind is ionized by increasing X-ray emission.

  2. Absorptive products

    International Nuclear Information System (INIS)

    Assarsson, P.G.; King, P.A.

    1976-01-01

    Applications for hydrophile gels produced by the radiation induced cross-linking in aqueous solution of polyethylene oxide and starch, as described in Norwegian patent 133501 (INIS RN 281494), such as sanitary napkins (diapers) and sanitary towels, are discussed. The process itself is also discussed and results, expressed as the percentage of insoluble gel and its absorptive capacity for saline solution as functions of the ratio of polyethylene oxide to starch and the radiation dose, are presented. (JIW)

  3. Constructing organic D-A-π-A-featured sensitizers with a quinoxaline unit for high-efficiency solar cells: the effect of an auxiliary acceptor on the absorption and the energy level alignment.

    Science.gov (United States)

    Pei, Kai; Wu, Yongzhen; Wu, Wenjun; Zhang, Qiong; Chen, Baoqin; Tian, He; Zhu, Weihong

    2012-06-25

    Four organic D-A-π-A-featured sensitizers (TQ1, TQ2, IQ1, and IQ2) have been studied for high-efficiency dye-sensitized solar cells (DSSCs). We employed an indoline or a triphenylamine unit as the donor, cyanoacetic acid as the acceptor/anchor, and a thiophene moiety as the conjugation bridge. Additionally, an electron-withdrawing quinoxaline unit was incorporated between the donor and the π-conjugation unit. These sensitizers show an additional absorption band covering the broad visible range in solution. The contribution from the incorporated quinoxaline was investigated theoretically by using DFT and time-dependent DFT. The incorporated low-band-gap quinoxaline unit as an auxiliary acceptor has several merits, such as decreasing the band gap, optimizing the energy levels, and realizing a facile structural modification on several positions in the quinoxaline unit. As demonstrated, the observed additional absorption band is favorable to the photon-to-electron conversion because it corresponds to the efficient electron transitions to the LUMO orbital. Electrochemical impedance spectroscopy (EIS) Bode plots reveal that the replacement of a methoxy group with an octyloxy group can increase the injection electron lifetime by a factor of 2.4. IQ2 and TQ2 can perform well without any co-adsorbent, successfully suppress the charge recombination from TiO(2) conduction band to I(3)(-) in the electrolyte, and enhance the electron lifetime, resulting in a decreased dark current and enhanced open circuit voltage (V(oc)) values. By using a liquid electrolyte, DSSCs based on dye IQ2 exhibited a broad incident photon-to-current conversion efficiency (IPCE) action spectrum and high efficiency (η=8.50 %) with a short circuit current density (J(sc)) of 15.65 mA cm(-2), a V(oc) value of 776 mV, a fill factor (FF) of 0.70 under AM 1.5 illumination (100 mW cm(-2)). Moreover, the overall efficiency remained at 97% of the initial value after 1000 h of visible

  4. Enhanced index and negative dispersion without absorption in driven cascade media

    International Nuclear Information System (INIS)

    Hu Xiangming; Xu Jun

    2004-01-01

    In this paper we investigate the dispersive and absorptive properties of a system of three-level cascade atoms driven by a strong coherent field. Three characteristic features are found. First, for the same set of atom-light interaction parameters, the indices of refraction are large at three different frequencies where the absorption vanishes. These three frequencies are determined by the resonance transition frequencies between dressed states produced by the strong driving field. Second, negative dispersion without absorption, which leads to superluminal light propagation, is achievable in the central resonance structure of the dispersion spectrum. Third, the whole absorption spectrum displays, in general, three pairs of absorption peaks and three pairs of gain (negative absorption) peaks. The minimal spacing between dressed states determines whether the outer adjacent gain peaks are separated from each other

  5. H I absorption in nearby compact radio galaxies

    Science.gov (United States)

    Glowacki, M.; Allison, J. R.; Sadler, E. M.; Moss, V. A.; Curran, S. J.; Musaeva, A.; Deng, C.; Parry, R.; Sligo, M. C.

    2017-05-01

    H I absorption studies yield information on both active galactic nucleus (AGN) feeding and feedback processes. This AGN activity interacts with the neutral gas in compact radio sources, which are believed to represent the young or recently re-triggered AGN population. We present the results of a survey for H I absorption in a sample of 66 compact radio sources at 0.040 100 km s-1) features, indicative of disturbed gas kinematics. Such broad, shallow and offset features are also found within low-excitation radio galaxies which is attributed to disturbed circumnuclear gas, consistent with early-type galaxies typically devoid of a gas-rich disc. Comparing mid-infrared colours of our galaxies with H I detections indicates that narrow and deep absorption features are preferentially found in late-type and high-excitation radio galaxies in our sample. These features are attributed to gas in galactic discs. By combining XMM-Newton archival data with 21-cm data, we find support that absorbed X-ray sources may be good tracers of H I content within the host galaxy. This sample extends previous H I surveys in compact radio galaxies to lower radio luminosities and provides a basis for future work exploring the higher redshift universe.

  6. Lactulose stimulates calcium absorption in postmenopausal women

    NARCIS (Netherlands)

    Heuvel, E.G.H.M. van den; Muijs, T.; Dokkum, W. van; Schaafsma, G.

    1999-01-01

    Animal studies have indicated that calcium absorption is increased by lactulose, a synthetic disaccharide. Therefore, the influence of lactulose on calcium absorption was measured in postmenopausal women who may benefit from the possible enhancing effect of lactulose on calcium absorption. Twelve

  7. Surface Textures and Features Indicative of Endogenous Growth at the McCartys Flow Field, NM, as an Analog to Martian Volcanic Plains

    Science.gov (United States)

    Bleacher, Jacob E.; Crumpler, L. S.; Garry, W. B.; Zimbelman, J. R.; Self, S.; Aubele, J. C.

    2012-01-01

    squeeze-outs along the pit walls that form when the rising crust exposes the still liquid core of the sheet. The plains of Tharsis and Elysium, Mars, display many analogous features

  8. Ultrasound image features of intravesical prostatic protrusion indicated failure of medication therapy of finasteride and doxazosin in patients with benign prostatic hyperplasia (LUTS/BPH).

    Science.gov (United States)

    Liu, Qiang; Zhu, Yunkai; Liu, Jianping; Qi, Jun; Kang, Jian

    2017-03-01

    Intravesical prostatic protrusion (IPP) is a type of benign prostatic hyperplasia (BPH) adenoma, and it plays a critical role in the pathogenesis of bladder outlet obstruction in patients with lower urinary tract syndromes (LUTS/BPH). The goal of this study was to investigate the effect of a combination therapy with finasteride and doxazosin on IPP in BPU/LUTS patients. A total of 322 BPH patients with enlarged prostatic volume as well as moderate to severe symptom scores were enrolled and divided into four groups according to the degree of IPP (IPP > 10 mm, 5-10 mm,  0.05). Failure rates of the medication differed significantly among the four groups. The study indicated that the combination therapy using finasteride and doxazosin could not reduce the degree of IPP. LUTS/BPH patients with IPP which contributes to the failure of medication tend to have a higher risk of progression.

  9. A SURVEY OF ALKALI LINE ABSORPTION IN EXOPLANETARY ATMOSPHERES

    International Nuclear Information System (INIS)

    Jensen, Adam G.; Redfield, Seth; Endl, Michael; Cochran, William D.; Koesterke, Lars; Barman, Travis S.

    2011-01-01

    We obtained over 90 hr of spectroscopic observations of four exoplanetary systems with the Hobby-Eberly Telescope. Observations were taken in transit and out of transit, and we analyzed the differenced spectra—i.e., the transmission spectra—to inspect it for absorption at the wavelengths of the neutral sodium (Na I) doublet at λλ5889, 5895 and neutral potassium (K I) at λ7698. We used the transmission spectrum at Ca I λ6122—which shows strong stellar absorption but is not an alkali metal resonance line that we expect to show significant absorption in these atmospheres—as a control line to examine our measurements for systematic errors. We use an empirical Monte Carlo method to quantify these systematic errors. In a reanalysis of the same data set using a reduction and analysis pipeline that was derived independently, we confirm the previously seen Na I absorption in HD 189733b at a level of (– 5.26 ± 1.69) × 10 –4 (the average value over a 12 Å integration band to be consistent with previous authors). Additionally, we tentatively confirm the Na I absorption seen in HD 209458b (independently by multiple authors) at a level of (– 2.63 ± 0.81) × 10 –4 , though the interpretation is less clear. Furthermore, we find Na I absorption of (– 3.16 ± 2.06) × 10 –4 at <3σ in HD 149026b; features apparent in the transmission spectrum are consistent with real absorption and indicate this may be a good target for future observations to confirm. No other results (Na I in HD 147506b and Ca I and K I in all four targets) are significant to ≥3σ, although we observe some features that we argue are primarily artifacts.

  10. Subgap absorption in conjugated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, M.; Seager, C.H. (Sandia National Labs., Albuquerque, NM (USA)); McBranch, D.; Heeger, A.J. (California Univ., Santa Barbara, CA (USA)); Baker, G.L. (Bell Communications Research, Inc., Red Bank, NJ (USA))

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10{sup {minus}5}, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of transparent'' materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination. 11 refs., 4 figs.

  11. Comparison of low-cost handheld retinal camera and traditional table top retinal camera in the detection of retinal features indicating a risk of cardiovascular disease

    Science.gov (United States)

    Joshi, V.; Wigdahl, J.; Nemeth, S.; Zamora, G.; Ebrahim, E.; Soliz, P.

    2018-02-01

    Retinal abnormalities associated with hypertensive retinopathy are useful in assessing the risk of cardiovascular disease, heart failure, and stroke. Assessing these risks as part of primary care can lead to a decrease in the incidence of cardiovascular disease-related deaths. Primary care is a resource limited setting where low cost retinal cameras may bring needed help without compromising care. We compared a low-cost handheld retinal camera to a traditional table top retinal camera on their optical characteristics and performance to detect hypertensive retinopathy. A retrospective dataset of N=40 subjects (28 with hypertensive retinopathy, 12 controls) was used from a clinical study conducted at a primary care clinic in Texas. Non-mydriatic retinal fundus images were acquired using a Pictor Plus hand held camera (Volk Optical Inc.) and a Canon CR1-Mark II tabletop camera (Canon USA) during the same encounter. The images from each camera were graded by a licensed optometrist according to the universally accepted Keith-Wagener-Barker Hypertensive Retinopathy Classification System, three weeks apart to minimize memory bias. The sensitivity of the hand-held camera to detect any level of hypertensive retinopathy was 86% compared to the Canon. Insufficient photographer's skills produced 70% of the false negative cases. The other 30% were due to the handheld camera's insufficient spatial resolution to resolve the vascular changes such as minor A/V nicking and copper wiring, but these were associated with non-referable disease. Physician evaluation of the performance of the handheld camera indicates it is sufficient to provide high risk patients with adequate follow up and management.

  12. Subgap Absorption in Conjugated Polymers

    Science.gov (United States)

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

    1991-01-01

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

  13. Lack of dust in quasar absorption line systems

    International Nuclear Information System (INIS)

    Jura, M.

    1977-01-01

    It is stated that the origin of absorption line systems in quasars is still uncertain. Most such systems apparently have atomic hydrogen column densities of the order of 10 19 /cm 2 , but at least two quasars, 1331 + 170 and PHL957, have such strong Lyman α absorption lines that atomic hydrogen column densities of the order of 10 21 /cm 2 are indicated. It should be possible to observe the dust produced 2,200 A extinction feature as it is red shifted into the visible, and to determine whether absorption line systems are produced in spiral galaxies where the dust content is similar to that in the interstellar medium. It has been argued that the emission line regions of quasars generally lack dust and that towards PHL957 the 2,200 A feature is absent. The present author argues that dust similar to that found in the interstellar medium is not found towards the quasars 1331 + 170 and PHL957. This could explain why H 2 is not found towards PHL957, and it indicates that the absorption line systems in quasars are not produced in spiral galaxies similar to our own. It seems from the analysis presented that the dust-to-gas ratio towards 1331 + 170 is at least a factor of 20 less than in the interstellar medium, and there is no reason to suppose that this lack of dust results from a lack of metals It is concluded that there seems to be a lack of normal dust towards PHL957 by at least a factor of two; and that the absorption region towards 1331 + 170 and probably the region towards PHL957 are lacking dust similar to that in our own galaxy. This can explain the lack of H 2 in these systems. (U.K.)

  14. Iron absorption in relation to iron status

    International Nuclear Information System (INIS)

    Magnusson, B.; Bjoern-Rasmussen, E.; Hallberg, L.; Rossander, L.

    1981-01-01

    The absorption from a 3 mg dose of ferrous iron was measured in 250 male subjects. The absorption was related to the log concentration of serum ferritin in 186 subjects of whom 99 were regular blood donors (r= -0.76), and to bone marrow haemosiderin grading in 52 subjects with varying iron status. The purpose was to try and establish a percentage absorption from such a dose that is representative of subjects who are borderline iron deficient. This information is necessary for food iron absorption studies in order (1) to calculate the absorption of iron from the diet at a given iron status and (2) compare the absorption of iron from different meals studied in different groups of subjects by different investigarors. The results suggest that an absorption of about 40% of a 3 mg reference dose of ferrous iron is given in a fasting state, roughly corresponds to the absorption in borderline-iron-deficient subjects. The results indicate that this 40% absorption value corresponds to a serum ferritin level of 30 μg/l and that food iron absorption in a group of subjects should be expressed preferably as the absorption corresponding to a reference-dose absorption of 45%, or possibly a serum ferritin level of 30 μg/l. (author)

  15. Simultaneous infrared and UV-visible absorption spectra of matrix-isolated carbon vapor

    Science.gov (United States)

    Kurtz, Joe; Huffman, Donald R.

    1989-01-01

    Carbon molecules were suggested as possible carriers of the diffuse interstellar bands. In particular, it was proposed that the 443 nm diffuse interstellar band is due to the same molecule which gives rise to the 447 nm absorption feature in argon matrix-isolated carbon vapor. If so, then an associated C-C stretching mode should be seen in the IR. By doing spectroscopy in both the IR and UV-visible regions on the same sample, the present work provides evidence for correlating UV-visible absorption features with those found in the IR. Early data indicates no correlation between the strongest IR feature (1997/cm) and the 447 nm band. Correlation with weaker IR features is being investigated.

  16. WATER ABSORPTION FROM GAS VERY NEAR THE MASSIVE PROTOSTAR AFGL 2136 IRS 1

    International Nuclear Information System (INIS)

    Indriolo, Nick; Neufeld, D. A.; Seifahrt, A.; Richter, M. J.

    2013-01-01

    We present ground-based observations of the ν 1 and ν 3 fundamental bands of H 2 O toward the massive protostar AFGL 2136 IRS 1, identifying absorption features due to 47 different ro-vibrational transitions between 2.468 μm and 2.561 μm. Analysis of these features indicates the absorption arises in warm (T = 506 ± 25 K), very dense (n(H 2 ) > 5 × 10 9 cm –3 ) gas, suggesting an origin close to the central protostar. The total column density of warm water is estimated to be N(H 2 O) = (1.02 ± 0.02) × 10 19 cm –2 , giving a relative abundance of N(H 2 O)/N(H 2 ) ≈ 10 –4 . Our study represents the first extensive use of water vapor absorption lines in the near infrared, and demonstrates the utility of such observations in deriving physical parameters

  17. Effect of in-material losses on terahertz absorption, transmission, and reflection in photonic crystals made of polar dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Serebryannikov, Andriy E., E-mail: andser@amu.edu.pl [Faculty of Physics, Adam Mickiewicz University, 61-614 Poznań (Poland); Nanotechnology Research Center—NANOTAM, Bilkent University, 06800 Ankara (Turkey); Nojima, S. [Yokohama City University, Department of Nanosystem Science, Graduate School of Nanobioscience, Kanazawa Ku, 22-2 Seto, Yokohama, Kanagawa 2360027 (Japan); Alici, K. B. [TUBITAK Marmara Research Center, Materials Institute, 41470 Gebze, Kocaeli (Turkey); Ozbay, Ekmel [Nanotechnology Research Center—NANOTAM, Bilkent University, 06800 Ankara (Turkey)

    2015-10-07

    The effect of the material absorption factor on terahertz absorption (A), transmittance (T), and reflectance (R) for slabs of PhC that comprise rods made of GaAs, a polar dielectric, is studied. The main goal was to illustrate how critical a choice of the absorption factor for simulations is and to indicate the importance of the possible modification of the absorption ability by using either active or lossy impurities. The spectra of A, T, and R are strongly sensitive to the location of the polaritonic gap with respect to the photonic pass and stop bands connected with periodicity that enables the efficient combination of the effects of material and structural parameters. It will be shown that the spectra can strongly depend on the utilized value of the material absorption factor. In particular, both narrow and wide absorption bands may appear owing to a variation of the material parameters with a frequency in the vicinity of the polaritonic gap. The latter are often achieved at wideband suppression of transmission, so that an ultra-wide stop band can appear as a result of adjustment of the stop bands having different origin. The results obtained at simultaneous variation of the absorption factor and frequency, and angle of incidence and frequency, indicate the possibility of the existence of wide ranges of tolerance, in which the basic features do remain. This allows for mitigating the accuracy requirements for the absorption factor in simulations and promises the efficient absorption of nonmonochromatic waves and beams with a wide angular spectrum. Suppression of narrowband effects in transmission is demonstrated at rather large values of the absorption factor, when they appear due to either the defect modes related to structural defects or dispersion inspired variations of the material parameters in the vicinity of the polaritonic gap. Comparison with auxiliary structures helps one to detect the common features and differences of homogeneous slabs and slabs of a

  18. Absorption and excretion tests

    International Nuclear Information System (INIS)

    Berberich, R.

    1988-01-01

    The absorption and excretion of radiopharmaceuticals is still of interest in diagnostic investigations of nuclear medicine. In this paper the most common methods of measuring absorption and excretion are described. The performance of the different tests and their standard values are discussed. More over the basic possibilities of measuring absorption and excretion including the needed measurement equipments are presented. (orig.) [de

  19. Understanding Legacy Features with Featureous

    DEFF Research Database (Denmark)

    Olszak, Andrzej; Jørgensen, Bo Nørregaard

    2011-01-01

    Java programs called Featureous that addresses this issue. Featureous allows a programmer to easily establish feature-code traceability links and to analyze their characteristics using a number of visualizations. Featureous is an extension to the NetBeans IDE, and can itself be extended by third...

  20. Mercury absorption in aqueous hypochlorite

    International Nuclear Information System (INIS)

    Zhao, L.L.; Rochelle, G.T.

    1999-01-01

    The absorption of elemental Hg vapor into aqueous hypochlorite was measured in a stirred tank reactor at 25 and 55C. NaOCl strongly absorbs Hg even at high pH. Low pH, high Cl - and high-temperature favor mercury absorption. Aqueous free Cl 2 was the active species that reacted with mercury. However, chlorine desorption was evident at high Cl - and pH 15 M -1 s -1 at 25C and 1.4x10 17 M -1 s -1 at 55C. Gas-phase reaction was observed between Hg and Cl 2 on apparatus surfaces. Strong mercury absorption in water was also detected with Cl 2 present. Results indicate that the chlorine concentration, moisture, and surface area contribute positively to mercury removal. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  1. Feature Article

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. Feature Article. Articles in Resonance – Journal of Science Education. Volume 1 Issue 1 January 1996 pp 80-85 Feature Article. What's New in Computers Windows 95 · Vijnan Shastri · More Details Fulltext PDF. Volume 1 Issue 1 January 1996 pp 86-89 Feature ...

  2. [Study on lead absorption in pumpkin by atomic absorption spectrophotometry].

    Science.gov (United States)

    Li, Zhen-Xia; Sun, Yong-Dong; Chen, Bi-Hua; Li, Xin-Zheng

    2008-07-01

    A study was carried out on the characteristic of lead absorption in pumpkin via atomic absorption spectrophotometer. The results showed that lead absorption amount in pumpkin increased with time, but the absorption rate decreased with time; And the lead absorption amount reached the peak in pH 7. Lead and cadmium have similar characteristic of absorption in pumpkin.

  3. Absorption heat pumps

    International Nuclear Information System (INIS)

    Formigoni, C.

    1998-01-01

    A brief description of the difference between a compression and an absorption heat pump is made, and the reasons why absorption systems have spread lately are given. Studies and projects recently started in the field of absorption heat pumps, as well as criteria usually followed in project development are described. An outline (performance targets, basic components) of a project on a water/air absorption heat pump, running on natural gas or LPG, is given. The project was developed by the Robur Group as an evolution of a water absorption refrigerator operating with a water/ammonia solution, which has been on the market for a long time and recently innovated. Finally, a list of the main energy and cost advantages deriving from the use of absorption heat pumps is made [it

  4. Aerosol Absorption Measurements in MILAGRO.

    Science.gov (United States)

    Gaffney, J. S.; Marley, N. A.; Arnott, W. P.; Paredes-Miranda, L.; Barnard, J. C.

    2007-12-01

    During the month of March 2006, a number of instruments were used to determine the absorption characteristics of aerosols found in the Mexico City Megacity and nearby Valley of Mexico. These measurements were taken as part of the Department of Energy's Megacity Aerosol Experiment - Mexico City (MAX-Mex) that was carried out in collaboration with the Megacity Interactions: Local and Global Research Observations (MILAGRO) campaign. MILAGRO was a joint effort between the DOE, NSF, NASA, and Mexican agencies aimed at understanding the impacts of a megacity on the urban and regional scale. A super-site was operated at the Instituto Mexicano de Petroleo in Mexico City (designated T-0) and at the Universidad Technologica de Tecamac (designated T-1) that was located about 35 km to the north east of the T-0 site in the State of Mexico. A third site was located at a private rancho in the State of Hidalgo approximately another 35 km to the northeast (designated T-2). Aerosol absorption measurements were taken in real time using a number of instruments at the T-0 and T-1 sites. These included a seven wavelength aethalometer, a multi-angle absorption photometer (MAAP), and a photo-acoustic spectrometer. Aerosol absorption was also derived from spectral radiometers including a multi-filter rotating band spectral radiometer (MFRSR). The results clearly indicate that there is significant aerosol absorption by the aerosols in the Mexico City megacity region. The absorption can lead to single scattering albedo reduction leading to values below 0.5 under some circumstances. The absorption is also found to deviate from that expected for a "well-behaved" soot anticipated from diesel engine emissions, i.e. from a simple 1/lambda wavelength dependence for absorption. Indeed, enhanced absorption is seen in the region of 300-450 nm in many cases, particularly in the afternoon periods indicating that secondary organic aerosols are contributing to the aerosol absorption. This is likely due

  5. Volcanic features of Io

    International Nuclear Information System (INIS)

    Carr, M.H.; Masursky, H.; Strom, R.G.; Terrile, R.J.

    1979-01-01

    The volcanic features of Io as detected during the Voyager mission are discussed. The volcanic activity is apparently higher than on any other body in the Solar System. Its volcanic landforms are compared with features on Earth to indicate the type of volcanism present on Io. (U.K.)

  6. Solar absorption surface panel

    Science.gov (United States)

    Santala, Teuvo J.

    1978-01-01

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

  7. Nutrition and magnesium absorption

    NARCIS (Netherlands)

    Brink, E.J.

    1992-01-01

    The influence of various nutrients present in dairy products and soybean-based products on absorption of magnesium has been investigated. The studies demonstrate that soybean protein versus casein lowers apparent magnesium absorption in rats through its phytate component. However, true

  8. Zeeman atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Loos-Vollebregt, M.T.C. de.

    1980-01-01

    A new method of background correction in atomic absorption spectroscopy has recently been introduced, based on the Zeeman splitting of spectral lines in a magnetic field. A theoretical analysis of the background correction capability observed in such instruments is presented. A Zeeman atomic absorption spectrometer utilizing a 50 Hz sine wave modulated magnetic field is described. (Auth.)

  9. Threshold nonlinear absorption in Zeeman transitions

    International Nuclear Information System (INIS)

    Narayanan, Andal; Hazra, Abheera; Sandhya, S N

    2010-01-01

    We experimentally study the absorption spectroscopy from a collection of gaseous 87 Rb atoms at room temperature irradiated with three fields. Two of these fields are in a pump-probe saturation absorption configuration. The third field co-propagates with the pump field. The three fields address Zeeman degenerate transitions between hyperfine levels 5S 1/2 , F = 1 and 5P 3/2 , F = 0, F = 1 around the D2 line. We find a sub-natural absorption resonance in the counter-propagating probe field for equal detunings of all three fields. This absorption arises in conjunction with the appearance of increased transmission due to electro-magnetically induced transparency in the co-propagating fields. The novel feature of this absorption is its onset only for the blue of 5P 3/2 , F = 0, as the laser frequency is scanned through the excited states 5P 3/2 , F = 0, F = 1 and F = 2. The absorption rapidly rises to near maximum values within a narrow band of frequency near 5P 3/2 , F = 0. Our experimental results are compared with a dressed atom model. We find the threshold absorption to be a result of coherent interaction between the dressed states of our system.

  10. A cylindrical furnace for absorption spectral studies

    Indian Academy of Sciences (India)

    A cylindrical furnace with three heating zones, capable of providing a temperature of 1100°C, has been fabricated to enable recording of absorption spectra of high temperature species. The temperature of the furnace can be controlled to ± 1°C of the set temperature. The salient feature of this furnace is that the material ...

  11. An Induced Pluripotent Stem Cell Patient Specific Model of Complement Factor H (Y402H) Polymorphism Displays Characteristic Features of Age-Related Macular Degeneration and Indicates a Beneficial Role for UV Light Exposure.

    Science.gov (United States)

    Hallam, Dean; Collin, Joseph; Bojic, Sanja; Chichagova, Valeria; Buskin, Adriana; Xu, Yaobo; Lafage, Lucia; Otten, Elsje G; Anyfantis, George; Mellough, Carla; Przyborski, Stefan; Alharthi, Sameer; Korolchuk, Viktor; Lotery, Andrew; Saretzki, Gabriele; McKibbin, Martin; Armstrong, Lyle; Steel, David; Kavanagh, David; Lako, Majlinda

    2017-11-01

    Age-related macular degeneration (AMD) is the most common cause of blindness, accounting for 8.7% of all blindness globally. Vision loss is caused ultimately by apoptosis of the retinal pigment epithelium (RPE) and overlying photoreceptors. Treatments are evolving for the wet form of the disease; however, these do not exist for the dry form. Complement factor H polymorphism in exon 9 (Y402H) has shown a strong association with susceptibility to AMD resulting in complement activation, recruitment of phagocytes, RPE damage, and visual decline. We have derived and characterized induced pluripotent stem cell (iPSC) lines from two subjects without AMD and low-risk genotype and two patients with advanced AMD and high-risk genotype and generated RPE cells that show local secretion of several proteins involved in the complement pathway including factor H, factor I, and factor H-like protein 1. The iPSC RPE cells derived from high-risk patients mimic several key features of AMD including increased inflammation and cellular stress, accumulation of lipid droplets, impaired autophagy, and deposition of "drüsen"-like deposits. The low- and high-risk RPE cells respond differently to intermittent exposure to UV light, which leads to an improvement in cellular and functional phenotype only in the high-risk AMD-RPE cells. Taken together, our data indicate that the patient specific iPSC model provides a robust platform for understanding the role of complement activation in AMD, evaluating new therapies based on complement modulation and drug testing. Stem Cells 2017;35:2305-2320. © 2017 The Authors Stem Cells published by Wiley Periodicals, Inc. on behalf of AlphaMed Press.

  12. Quasar Absorption Studies

    Science.gov (United States)

    Mushotzky, Richard (Technical Monitor); Elvis, Martin

    2004-01-01

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

  13. Feature Extraction

    CERN Document Server

    CERN. Geneva

    2015-01-01

    Feature selection and reduction are key to robust multivariate analyses. In this talk I will focus on pros and cons of various variable selection methods and focus on those that are most relevant in the context of HEP.

  14. Solar Features

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of solar feature datasets contributed by a number of national and private solar observatories located worldwide.

  15. Site Features

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset consists of various site features from multiple Superfund sites in U.S. EPA Region 8. These data were acquired from multiple sources at different times...

  16. Uranium absorption study pile

    International Nuclear Information System (INIS)

    Raievski, V.; Sautiez, B.

    1959-01-01

    The report describes a pile designed to measure the absorption of fuel slugs. The pile is of graphite and comprises a central section composed of uranium rods in a regular lattice. RaBe sources and BF 3 counters are situated on either side of the center. A given uranium charge is compared with a specimen charge of about 560 kg, and the difference in absorption between the two noted. The sensitivity of the equipment will detect absorption variations of about a few ppm boron (10 -6 boron per gr. of uranium) or better. (author) [fr

  17. Total photon absorption

    International Nuclear Information System (INIS)

    Carlos, P.

    1985-06-01

    The present discussion is limited to a presentation of the most recent total photonuclear absorption experiments performed with real photons at intermediate energy, and more precisely in the region of nucleon resonances. The main sources of real photons are briefly reviewed and the experimental procedures used for total photonuclear absorption cross section measurements. The main results obtained below 140 MeV photon energy as well as above 2 GeV are recalled. The experimental study of total photonuclear absorption in the nuclear resonance region (140 MeV< E<2 GeV) is still at its beginning and some results are presented

  18. Aerosol Angstrom Absorption Coefficient Comparisons during MILAGRO.

    Science.gov (United States)

    Marley, N. A.; Marchany-Rivera, A.; Kelley, K. L.; Mangu, A.; Gaffney, J. S.

    2007-12-01

    Measurements of aerosol absorption were obtained as part of the MAX-Mex component of the MILAGRO field campaign at site T0 (Instituto Mexicano de Petroleo in Mexico City) by using a 7-channel aethalometer (Thermo- Anderson) during the month of March, 2006. The absorption measurements obtained in the field at 370, 470, 520, 590, 660, 880, and 950 nm were used to determine the aerosol Angstrom absorption exponents by linear regression. Since, unlike other absorbing aerosol species (e.g. humic like substances, nitrated PAHs), black carbon absorption is relatively constant from the ultraviolet to the infrared with an Angstrom absorption exponent of -1 (1), a comparison of the Angstrom exponents can indicate the presence of aerosol components with an enhanced UV absorption over that expected from BC content alone. The Angstrom exponents determined from the aerosol absorption measurements obtained in the field varied from - 0.7 to - 1.3 during the study and was generally lower in the afternoon than the morning hours, indicating an increase in secondary aerosol formation and photochemically generated UV absorbing species in the afternoon. Twelve-hour integrated samples of fine atmospheric aerosols (Petroleo (IMP) and CENICA.

  19. Imaging features of thalassemia

    Energy Technology Data Exchange (ETDEWEB)

    Tunaci, M.; Tunaci, A.; Engin, G.; Oezkorkmaz, B.; Acunas, G.; Acunas, B. [Dept. of Radiology, Istanbul Univ. (Turkey); Dincol, G. [Dept. of Internal Medicine, Istanbul Univ. (Turkey)

    1999-07-01

    Thalassemia is a kind of chronic, inherited, microcytic anemia characterized by defective hemoglobin synthesis and ineffective erythropoiesis. In all thalassemias clinical features that result from anemia, transfusional, and absorptive iron overload are similar but vary in severity. The radiographic features of {beta}-thalassemia are due in large part to marrow hyperplasia. Markedly expanded marrow space lead to various skeletal manifestations including spine, skull, facial bones, and ribs. Extramedullary hematopoiesis (ExmH), hemosiderosis, and cholelithiasis are among the non-skeletal manifestations of thalassemia. The skeletal X-ray findings show characteristics of chronic overactivity of the marrow. In this article both skeletal and non-skeletal manifestations of thalassemia are discussed with an overview of X-ray findings, including MRI and CT findings. (orig.)

  20. Imaging features of thalassemia

    International Nuclear Information System (INIS)

    Tunaci, M.; Tunaci, A.; Engin, G.; Oezkorkmaz, B.; Acunas, G.; Acunas, B.; Dincol, G.

    1999-01-01

    Thalassemia is a kind of chronic, inherited, microcytic anemia characterized by defective hemoglobin synthesis and ineffective erythropoiesis. In all thalassemias clinical features that result from anemia, transfusional, and absorptive iron overload are similar but vary in severity. The radiographic features of β-thalassemia are due in large part to marrow hyperplasia. Markedly expanded marrow space lead to various skeletal manifestations including spine, skull, facial bones, and ribs. Extramedullary hematopoiesis (ExmH), hemosiderosis, and cholelithiasis are among the non-skeletal manifestations of thalassemia. The skeletal X-ray findings show characteristics of chronic overactivity of the marrow. In this article both skeletal and non-skeletal manifestations of thalassemia are discussed with an overview of X-ray findings, including MRI and CT findings. (orig.)

  1. Absorption heat pump system

    Science.gov (United States)

    Grossman, G.

    1982-06-16

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

  2. Zeeman atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Hadeishi, T.; McLaughlin, R.

    1978-08-01

    The design and development of a Zeeman atomic absorption spectrometer for trace element analysis are described. An instruction manual is included which details the operation, adjustment, and maintenance. Specifications and circuit diagrams are given

  3. Revisiting Absorptive Capacity

    DEFF Research Database (Denmark)

    de Araújo, Ana Luiza Lara; Ulhøi, John Parm; Lettl, Christopher

    Absorptive capacity has mostly been perceived as a 'passive' outcome of R&D investments. Recently, however, a growing interest into its 'proactive' potentials has emerged. This paper taps into this development and proposes a dynamic model for conceptualizing the determinants of the complementary...... learning processes of absorptive capacity, which comprise combinative and adaptive capabilities. Drawing on survey data (n=169), the study concludes that combinative capabilities primarily enhance transformative and exploratory learning processes, while adaptive capabilities strengthen all three learning...

  4. Comment on resonant absorption

    International Nuclear Information System (INIS)

    Hammerling, P.

    1977-01-01

    An average over angles of incidence of the usual resonant absorption function is presented. This form is appropriate under experimental conditions where the angles of incidence vary greatly and in an unknown manner. For comparison a lens-ellipsoidal mirror illumination system with a known longitudinal aberration is considered. In the latter example the angles of incidence are readily obtained and the resulting resonance absorption function evaluated. The associated fields are calculated in a similar fashion. (author)

  5. Optical absorption measurement system

    International Nuclear Information System (INIS)

    Draggoo, V.G.; Morton, R.G.; Sawicki, R.H.; Bissinger, H.D.

    1989-01-01

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

  6. Absorption Spectra of Gold Nanoparticle Suspensions

    Science.gov (United States)

    Anan'eva, M. V.; Nurmukhametov, D. R.; Zverev, A. S.; Nelyubina, N. V.; Zvekov, A. A.; Russakov, D. M.; Kalenskii, A. V.; Eremenko, A. N.

    2018-02-01

    Three gold nanoparticle suspensions are obtained, and mean radii in distributions - (6.1 ± 0.2), (11.9 ± 0.3), and (17.3 ± 0.7) nm - are determined by the transmission electron microscopy method. The optical absorption spectra of suspensions are obtained and studied. Calculation of spectral dependences of the absorption index of suspensions at values of the gold complex refractive index taken from the literature showed a significant deviation of experimental and calculated data in the region of 450-800 nm. Spectral dependences of the absorption of suspensions are simulated within the framework of the Mie-Drude theory taking into account the interband absorption in the form of an additional term in the imaginary part of the dielectric permittivity of the Gaussian type. It is shown that to quantify the spectral dependences in the region of the plasmon absorption band of nanoparticles, correction of the parameters of the interband absorption is necessary in addition to the increase of the relaxation parameter of the Drude theory. Spectral dependences of the dielectric permittivity of gold in nanodimensional state are refined from the solution of the inverse problem. The results of the present work are important for predicting the special features of operation of photonic devices and optical detonators based on gold nanoparticles.

  7. Absorption optical density as a diagnostic tool for indicating the ...

    African Journals Online (AJOL)

    use

    2011-11-21

    Nov 21, 2011 ... of research involves the use of (GNPs) in the detection. Corressponding .... each use by sonicating them for 5 min in deionized water and then rinsing with .... accompanied by leakage of lysosomal hydrolytic enzymes that lead ...

  8. Vitamin A absorption

    International Nuclear Information System (INIS)

    Baker, S.J.

    1976-01-01

    Investigation of the absorption of vitamin A and related substances is complicated by the multiplicity of forms in which they occur in the diet and by the possibility that they may be subject to different mechanisms of absorption. Present knowledge of these mechanisms is inadequate, especially in the case of carotenoids. Numerous tests of absorption have been developed. The most common has been the biochemical measurement of the rise in plasma vitamin A after an oral dose of retinol or retinyl ester, but standardization is inadequate. Radioisotope tests based upon assay of serum or faecal activity following oral administration of tritiated vitamin A derivaties hold considerable promise, but again standardization is inadequate. From investigations hitherto performed it is known that absorption of vitamin A is influenced by several diseases, although as yet the consistency of results and the correlation with other tests of intestinal function have often been poor. However, the test of vitamin A absorption is nevertheless of clinical importance as a specialized measure of intestinal function. (author)

  9. Empirical Productivity Indices and Indicators

    NARCIS (Netherlands)

    B.M. Balk (Bert)

    2016-01-01

    textabstractThe empirical measurement of productivity change (or difference) by means of indices and indicators starts with the ex post profit/loss accounts of a production unit. Key concepts are profit, leading to indicators, and profitability, leading to indices. The main task for the productivity

  10. Modulation of intestinal absorption of calcium

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, P; Dupuis, Y [Ecole Pratique des Hautes Etudes, 75 - Paris (France); Paris-11 Univ., 92 - Chatenay-Malabry (France))

    1975-01-01

    Absorption of ingested calcium (2ml of a 10mM CaCl/sub 2/ solution + /sup 45/Ca) by the adult rat was shown to be facilitated by the simultaneous ingestion of an active carbohydrate, L-arabinose. As the carbohydrate concentration is increased from 10 to 200mM, the absorption of calcium is maximised at a level corresponding to about twice the control absorption level. A similar doubling of calcium absorption is obtained when a 100mM concentration of any one of a number of other carbohydrates is ingested simultaneously with a 10mM CaCl/sub 2/ solution. Conversely, the simultaneous ingestion of increasing doses (10 to 100mM) of phosphate (NaH/sub 2/PO/sub 4/) with a 10mM CaCl/sub 2/ solution results in decreased /sup 45/Ca absorption and retention by the adult rat. The maximum inhibition of calcium absorption by phosphate is independent of the concentration of the ingested calcium solution (from 5 to 50mM CaCl/sub 2/). The simultaneous ingestion of CaCl/sub 2/ (10mM) with lactose and sodium phosphate (50 and 10mM respectively) shows that the activation effect of lactose upon /sup 45/Ca absorption may be partly dissimulated by the presence of phosphate. These various observations indicate that, within a large concentration range (2 to 50mM CaCl/sub 2/) calcium absorption appears to be a precisely modulated diffusion process. Calcium absorption varies (between minimum and maximum levels) as a function of the state of saturation by the activators (carbohydrates) and inhibitors (phosphate) of the calcium transport system.

  11. Time-resolved absorption measurements on OMEGA

    International Nuclear Information System (INIS)

    Jaanimagi, P.A.; DaSilva, L.; Delettrez, J.; Gregory, G.G.; Richardson, M.C.

    1986-01-01

    Time-resolved measurements of the incident laser light that is scattered and/or refracted from targets irradiated by the 24 uv-beam OMEGA laser at LLE, have provided some interesting features related to time-resolved absorption. The decrease in laser absorption characteristic of irradiating a target that implodes during the laser pulse has been observed. The increase in absorption expected as the critical density surface moves from a low to a high Z material in the target has also been noted. The detailed interpretation of these results is made through comparisons with simulation using the code LILAC, as well as with streak data from time-resolved x-ray imaging and spectroscopy. In addition, time and space-resolved imaging of the scattered light yields information on laser irradiation uniformity conditions on the target. The report consists of viewgraphs

  12. Absorption spectra of AA-stacked graphite

    International Nuclear Information System (INIS)

    Chiu, C W; Lee, S H; Chen, S C; Lin, M F; Shyu, F L

    2010-01-01

    AA-stacked graphite shows strong anisotropy in geometric structures and velocity matrix elements. However, the absorption spectra are isotropic for the polarization vector on the graphene plane. The spectra exhibit one prominent plateau at middle energy and one shoulder structure at lower energy. These structures directly reflect the unique geometric and band structures and provide sufficient information for experimental fitting of the intralayer and interlayer atomic interactions. On the other hand, monolayer graphene shows a sharp absorption peak but no shoulder structure; AA-stacked bilayer graphene has two absorption peaks at middle energy and abruptly vanishes at lower energy. Furthermore, the isotropic features are expected to exist in other graphene-related systems. The calculated results and the predicted atomic interactions could be verified by optical measurements.

  13. Waste indicators

    Energy Technology Data Exchange (ETDEWEB)

    Dall, O.; Lassen, C.; Hansen, E. [Cowi A/S, Lyngby (Denmark)

    2003-07-01

    The Waste Indicator Project focuses on methods to evaluate the efficiency of waste management. The project proposes the use of three indicators for resource consumption, primary energy and landfill requirements, based on the life-cycle principles applied in the EDIP Project. Trial runs are made With the indicators on paper, glass packaging and aluminium, and two models are identified for mapping the Danish waste management, of which the least extensive focuses on real and potential savings. (au)

  14. Waste indicators

    International Nuclear Information System (INIS)

    Dall, O.; Lassen, C.; Hansen, E.

    2003-01-01

    The Waste Indicator Project focuses on methods to evaluate the efficiency of waste management. The project proposes the use of three indicators for resource consumption, primary energy and landfill requirements, based on the life-cycle principles applied in the EDIP Project. Trial runs are made With the indicators on paper, glass packaging and aluminium, and two models are identified for mapping the Danish waste management, of which the least extensive focuses on real and potential savings. (au)

  15. Quality indicators

    DEFF Research Database (Denmark)

    Hjorth-Andersen, Christian

    1991-01-01

    In recent literature it has been suggested that consumers need have no knowledge of product quality as a number of quality indicators (or signals) may be used as substitutes. Very little attention has been paid to the empirical verification of these studies. The present paper is devoted...... to the issue of how well these indicators perform, using market data provided by consumer magazines from 3 countries. The results strongly indicate that price is a poor quality indicator. The paper also presents some evidence which suggests that seller reputation and easily observable characteristics are also...

  16. Laser Absorption by Over-Critical Plasmas

    Science.gov (United States)

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

    2015-11-01

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

  17. Noble gas absorption process

    International Nuclear Information System (INIS)

    Thomas, J.W.

    1975-01-01

    A method of removing a noble gas from air comprising the use of activated carbon filters in stages in which absorption and desorption steps in succession are conducted in order to increase the capacity of the filters is described. (U.S.)

  18. Total photon absorption

    International Nuclear Information System (INIS)

    Carlos, P.

    1985-01-01

    Experimental methods using real photon beams for measurements of total photonuclear absorption cross section σ(Tot : E/sub γ/) are recalled. Most recent σ(Tot : E/sub γ/)results for complex nuclei and in the nucleon resonance region are presented

  19. Chemical Absorption Materials

    DEFF Research Database (Denmark)

    Thomsen, Kaj

    2011-01-01

    Chemical absorption materials that potentially can be used for post combustion carbon dioxide capture are discussed. They fall into five groups, alkanolamines, alkali carbonates, ammonia, amino acid salts, and ionic liquids. The chemistry of the materials is discussed and advantages and drawbacks...

  20. Zinc absorption in inflammatory bowel disease

    International Nuclear Information System (INIS)

    Valberg, L.S.; Flanagan, P.R.; Kertesz, A.; Bondy, D.C.

    1986-01-01

    Zinc absorption was measured in 29 patients with inflammatory bowel disease and a wide spectrum of disease activity to determine its relationship to disease activity, general nutritional state, and zinc status. Patients with severe disease requiring either supplementary oral or parenteral nutrition were excluded. The mean 65ZnCl2 absorption, in the patients, determined using a 65Zn and 51Cr stool-counting test, 45 +/- 17% (SD), was significantly lower than the values, 54 +/- 16%, in 30 healthy controls, P less than 0.05. Low 65ZnCl2 absorption was related to undernutrition, but not to disease activity in the absence of undernutrition or to zinc status estimated by leukocyte zinc measurements. Mean plasma zinc or leukocyte zinc concentrations in patients did not differ significantly from controls, and only two patients with moderate disease had leukocyte zinc values below the 5th percentile of normal. In another group of nine patients with inflammatory bowel disease of mild-to-moderate severity and minimal nutritional impairment, 65Zn absorption from an extrinsically labeled turkey test meal was 31 +/- 10% compared to 33 +/- 7% in 17 healthy controls, P greater than 0.1. Thus, impairment in 65ZnCl2 absorption in the patients selected for this study was only evident in undernourished persons with moderate or severe disease activity, but biochemical evidence of zinc deficiency was uncommon, and clinical features of zinc depletion were not encountered

  1. General indicators

    International Nuclear Information System (INIS)

    2003-01-01

    This document summarizes the main 2002 energy indicators for France. A first table lists the evolution of general indicators between 1973 and 2002: energy bill, price of imported crude oil, energy independence, primary and final energy consumption. The main 2002 results are detailed separately for natural gas, petroleum and coal (consumption, imports, exports, production, stocks, prices). (J.S.)

  2. Absorption of orally administered 65Zn by normal human subjects

    International Nuclear Information System (INIS)

    Aamodt, R.L.; Rumble, W.F.; Johnston, G.S.; Markley, E.J.; Henkin, R.I.

    1981-01-01

    Despite studies by several investigators of human gastrointestinal 65Zn absorption, implications of these data for evaluation of functional zinc status are unclear because limited numbers of normal subjects have been studied. To evaluated zinc absorption in normal humans, 75 subjects (31 women, 44 men, ages 18 to 84 yr) were given 10 micro Ci carrier-free 65Zn orally after an overnight fast. Absorption calculated from total body retention measured 7, 14, and 21 days after administration of tracer was 65 +/- 11% (mean +/- 1 SD), range from 40 to 86%. Comparison of these results with those for patients with a variety of diseases indicate that patients exhibit a wider range of absorption and, in four of six studies patients exhibit decreased mean zinc absorption. These results of gastrointestinal zinc absorption in a large number of normal humans offer a basis for a clearer comparison with data from patients who exhibit abnormalities of zinc absorption

  3. THE OXYGEN FEATURES IN TYPE Ia SUPERNOVAE AND IMPLICATIONS FOR THE NATURE OF THERMONUCLEAR EXPLOSIONS

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xulin; Wang, Xiaofeng; Sai, Hanna; Huang, Fang; Rui, Liming [Physics Department and Tsinghua Center for Astrophysics, Tsinghua University, Beijing, 100084 (China); Maeda, Keiichi [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Wang, Lifan [Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Zhang, Jujia [Yunnan Observatories, Chinese Academy of Sciences, Kunming, 650216 (China); Zhang, Tianmeng, E-mail: wang_xf@mail.tsinghua.edu.cn, E-mail: zhaoxl11@mails.tsinghua.edu.cn, E-mail: keiichi.maeda@kusastro.kyoto-u.ac.jp [National Astronomical Observatory of China, Chinese Academy of Sciences, Beijing, 100012 (China)

    2016-08-01

    The absorption feature O i λ 7773 is an important spectral indicator for type Ia supernovae (SNe Ia) that can be used to trace the unburned material in outer layers of the exploding white dwarf (WD). In this work, we use a large sample of SNe Ia to examine this absorption at early phases (i.e., 13 day ≲ t ≲ 7 day) and make comparisons with the absorption features of Si ii λ 6355 and the Ca ii near-infrared triplet. We show that for a subgroup of spectroscopically normal SNe with normal photospheric velocities (i.e., v {sub si} ≲ 12,500 km s{sup 1} at optical maximum), the line strength of the high velocity feature (HVF) of O i is inversely correlated with that of Si ii (or Ca ii), and this feature also shows a negative correlation with the luminosity of SNe Ia. This finding, together with other features we find for the O i HVF, reveal that for this subgroup of SNe Ia, explosive oxygen burning occurs in the outermost layer of the SN. Differences in the oxygen burning could lead to the observed diversity, which is in remarkable agreement with the popular delayed-detonation model of Chandrasekhar mass WDs.

  4. THE OXYGEN FEATURES IN TYPE Ia SUPERNOVAE AND IMPLICATIONS FOR THE NATURE OF THERMONUCLEAR EXPLOSIONS

    International Nuclear Information System (INIS)

    Zhao, Xulin; Wang, Xiaofeng; Sai, Hanna; Huang, Fang; Rui, Liming; Maeda, Keiichi; Wang, Lifan; Zhang, Jujia; Zhang, Tianmeng

    2016-01-01

    The absorption feature O i λ 7773 is an important spectral indicator for type Ia supernovae (SNe Ia) that can be used to trace the unburned material in outer layers of the exploding white dwarf (WD). In this work, we use a large sample of SNe Ia to examine this absorption at early phases (i.e., 13 day ≲ t ≲ 7 day) and make comparisons with the absorption features of Si ii λ 6355 and the Ca ii near-infrared triplet. We show that for a subgroup of spectroscopically normal SNe with normal photospheric velocities (i.e., v si ≲ 12,500 km s 1 at optical maximum), the line strength of the high velocity feature (HVF) of O i is inversely correlated with that of Si ii (or Ca ii), and this feature also shows a negative correlation with the luminosity of SNe Ia. This finding, together with other features we find for the O i HVF, reveal that for this subgroup of SNe Ia, explosive oxygen burning occurs in the outermost layer of the SN. Differences in the oxygen burning could lead to the observed diversity, which is in remarkable agreement with the popular delayed-detonation model of Chandrasekhar mass WDs.

  5. Featuring animacy

    Directory of Open Access Journals (Sweden)

    Elizabeth Ritter

    2015-01-01

    Full Text Available Algonquian languages are famous for their animacy-based grammatical properties—an animacy based noun classification system and direct/inverse system which gives rise to animacy hierarchy effects in the determination of verb agreement. In this paper I provide new evidence for the proposal that the distinctive properties of these languages is due to the use of participant-based features, rather than spatio-temporal ones, for both nominal and verbal functional categories (Ritter & Wiltschko 2009, 2014. Building on Wiltschko (2012, I develop a formal treatment of the Blackfoot aspectual system that assumes a category Inner Aspect (cf. MacDonald 2008, Travis 1991, 2010. Focusing on lexical aspect in Blackfoot, I demonstrate that the classification of both nouns (Seinsarten and verbs (Aktionsarten is based on animacy, rather than boundedness, resulting in a strikingly different aspectual system for both categories. 

  6. Solar Indices

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  7. Linear absorptive dielectrics

    Science.gov (United States)

    Tip, A.

    1998-06-01

    Starting from Maxwell's equations for a linear, nonconducting, absorptive, and dispersive medium, characterized by the constitutive equations D(x,t)=ɛ1(x)E(x,t)+∫t-∞dsχ(x,t-s)E(x,s) and H(x,t)=B(x,t), a unitary time evolution and canonical formalism is obtained. Given the complex, coordinate, and frequency-dependent, electric permeability ɛ(x,ω), no further assumptions are made. The procedure leads to a proper definition of band gaps in the periodic case and a new continuity equation for energy flow. An S-matrix formalism for scattering from lossy objects is presented in full detail. A quantized version of the formalism is derived and applied to the generation of Čerenkov and transition radiation as well as atomic decay. The last case suggests a useful generalization of the density of states to the absorptive situation.

  8. Iron absorption studies

    International Nuclear Information System (INIS)

    Ekenved, G.

    1976-01-01

    The main objective of the present work was to study iron absorption from different iron preparations in different types of subjects and under varying therapeutic conditions. The studies were performed with different radioiron isotope techniques and with a serum iron technique. The preparations used were solutions of ferrous sulphate and rapidly-disintegrating tablets containing ferrous sulphate, ferrous fumarate and ferrous carbonate and a slow-release ferrous sulphate tablet of an insoluble matrix type (Duroferon Durules). The serum iron method was evaluated and good correlation was found between the serum iron response and the total amount of iron absorbed after an oral dose of iron given in solution or in tablet form. New technique for studying the in-vivo release properties of tablets was presented. Iron tablets labelled with a radio-isotope were given to healthy subjects. The decline of the radioactivity in the tablets was followed by a profile scanning technique applied to different types of iron tablets. The release of iron from the two types of tablets was shown to be slower in vivo than in vitro. It was found that co-administration of antacids and iron tablets led to a marked reduction in the iron absorption and that these drugs should not be administered sumultaneously. A standardized meal markedly decreased the absorbability of iron from iron tablets. The influence of the meal was more marked with rapidly-disintegrating than with slow-release ferrous sulphate tablets. The absorption from rapidly-disintegrating and slow-release ferrous sulphate tablets was compared under practical clinical conditions during an extended treatment period. The studies were performed in healthy subjects, blood donors and patients with iron deficiency anaemia and it was found that the absorption of iron from the slow-release tablets was significantly better than from the rapidly-disintegrating tablets in all three groups of subjects. (author)

  9. Gamma absorption meter

    International Nuclear Information System (INIS)

    Dincklage, R.D. von.

    1984-01-01

    The absorption meter consists of a radiation source, a trough for the absorbing liquid and a detector. It is characterized by the fact that there is a foil between the detector and the trough, made of a material whose binding energy of the K electrons is a little greater than the energy of the photons emitted by the radiation source. The source of radiation and foil are replaceable. (orig./HP) [de

  10. Total Absorption Spectroscopy

    International Nuclear Information System (INIS)

    Rubio, B.; Gelletly, W.

    2007-01-01

    The problem of determining the distribution of beta decay strength (B(GT)) as a function of excitation energy in the daughter nucleus is discussed. Total Absorption Spectroscopy is shown to provide a way of determining the B(GT) precisely. A brief history of such measurements and a discussion of the advantages and disadvantages of this technique, is followed by examples of two recent studies using the technique. (authors)

  11. Intestinal absorption and secretion of 65Zn in the rat

    International Nuclear Information System (INIS)

    Methfessel, A.H.; Spencer, H.

    1974-01-01

    A single dose of 65 Zn Cl 2 was given by intubation to the intact rat or was instilled into the lumen of ligated intestinal sacs to determine the absorption, or injected intravenously via the tail vein to determine intestinal secretion of 65 Zn. Results indicated that the small intestine plays a major role in the absorption and secretion of zinc and that aging decreases the absorption of zinc for the duodenum of the rat

  12. SHARDS: Survey for High-z Absorption Red & Dead Sources

    Science.gov (United States)

    Pérez-González, P. G.; Cava, A.

    2013-05-01

    SHARDS, an ESO/GTC Large Program, is an ultra-deep (26.5 mag) spectro-photometric survey with GTC/OSIRIS designed to select and study massive passively evolving galaxies at z=1.0-2.3 in the GOODS-N field using a set of 24 medium-band filters (FWHM~17 nm) covering the 500-950 nm spectral range. Our observing strategy has been planned to detect, for z>1 sources, the prominent Mg absorption feature (at rest-frame ~280 nm), a distinctive, necessary, and sufficient feature of evolved stellar populations (older than 0.5 Gyr). These observations are being used to: (1) derive for the first time an unbiased sample of high-z quiescent galaxies, which extends to fainter magnitudes the samples selected with color techniques and spectroscopic surveys; (2) derive accurate ages and stellar masses based on robust measurements of spectral features such as the Mg_UV or D(4000) indices; (3) measure their redshift with an accuracy Δz/(1+z)<0.02; and (4) study emission-line galaxies (starbursts and AGN) up to very high redshifts. The well-sampled optical SEDs provided by SHARDS for all sources in the GOODS-N field are a valuable complement for current and future surveys carried out with other telescopes (e.g., Spitzer, HST, and Herschel).

  13. UV laser long-path absorption spectroscopy

    Science.gov (United States)

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

    1994-01-01

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

  14. Operational indicators

    International Nuclear Information System (INIS)

    2010-01-01

    The chapter presents the operational indicators related to budget, travel costs and tickets, the evolution of the annual program for regulatory inspection, the scientific production, requested patents and the numbers related to the production of the services offered by the Institution

  15. Nasal Absorption of Macromolecules from Powder Formulations and Effects of Sodium Carboxymethyl Cellulose on Their Absorption.

    Directory of Open Access Journals (Sweden)

    Akiko Tanaka

    Full Text Available The nasal absorption of macromolecules from powder formulations and the effect of sodium carboxymethyl cellulose (CMC-Na as a pharmaceutical excipient on their absorption were studied. Model macromolecules were fluorescein isothiocyanate-labeled dextran (average molecular weight of 4.4kDa, FD4 and insulin. The plasma concentration of FD4 after application of the powder containing 50% starch (control was higher than that after application of the solution, and the absorption from 50% starch powder was enhanced by the substitution of starch with CMC-Na. The fractional absorption of FD4 after administration of the CMC-Na powder formulation was 30% and 40% higher than that after administration from the solution and the starch powder, respectively. The nasal absorption of insulin from the powder and the effect of CMC-Na were similar with those of FD4. The effective absorption of FD4 and insulin after application of powder with CMC-Na could be due to the increase in the nasal residence of FD4 and insulin. No damage in the nasal mucosa or dysfunction of the mucociliary clearance was observed after application of the drug powder and CMC-Na. The present findings indicate that nasal delivery of powder formulations with the addition of CMC-Na as an excipient is a promising approach for improving the nasal absorption of macromolecules.

  16. Statistical evidences of absorption at high latitudes

    International Nuclear Information System (INIS)

    Fesenko, B.I.

    1980-01-01

    Evidences are considered which indicate to the significant effect of the irregular interstellar absorption at high latitudes b. The number density of faint galaxies grows with the increasing |b| even at the values of |b| exceeding 50 deg. The effects of interstellar medium are traced even in the directions of the stars and globular clusters with very low values of the colour excess. The coefficient of absorption, Asub(B)=0.29+-0.05, was estimated from the colours of the bright E-galaxies [ru

  17. Exciton absorption of entangled photons in semiconductor quantum wells

    Science.gov (United States)

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

    2013-03-01

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

  18. Galactic neutral hydrogen emission-absorption observations from Arecibo

    International Nuclear Information System (INIS)

    Dickey, J.M.; Salpeter, E.E.; Terzian, Y.

    1978-01-01

    We have observed the interstellar medium in the directions of 27 extragalactic sources at high and intermediate galactic latitudes (vertical-barb/sup ii/vertical-bar>5 0 ) at 21 cm wavelength with the upgraded Arecibo telescope (HPBW=3'.2, gainapprox.6 K Jy -1 ). The small beam greatly reduces the uncertainty in the derived on-source emission profile and increases confidence that it corresponds to the same material as the absorption spectrum. Each region has been observed for approximately 2 hours to tetect optical depths as low as 10 -2 in most cases. The data allow the derivation of optical depths, harmonic mean spin temperatures, and column densities for the neutral hydrogen as a function of velocity in the range -200 -1 (LSR) with resolution as fine as 0.25 km s -1 . Spin temperatures as high as 1000 K are evident with a significant fraction of the neutral hydrogen still hotter. The cooler material is distributed over all temperatures from 30 K to at least 800 K. At latitudes below vertical-barb/sup ii/vertical-bar 0 values for the harmonic mean temperature T/sub spin/ in the range 100 K to 300 K are most common.We have detected 66 separate absorption features, tentatively associated with neutral hydrogen clouds, with central temperatures ranging from 30 to 500 K. These features conform well to the relationship T/sub spin/=45(1-e/sup -tau/)/sup -0.5/ (K), over a broad range of values of the optical depth. The velocity distribution of these clouds shows a significant negative-velocity ''tail'' at high and intermediate latitudes. The mean square velocity of the clouds seems to depend on optical depth: v/sub rms/ is greater (approx.11 km s -1 ) for the optically thin clouds (tau -1 ). High-negative-velocity emission (v -1 ) has been detected in six directions; in two of these corresponding absorption features are evident, indicating cool neutral material

  19. Efficient energy absorption of intense ps-laser pulse into nanowire target

    Energy Technology Data Exchange (ETDEWEB)

    Habara, H.; Honda, S.; Katayama, M.; Tanaka, K. A. [Graduate School of Engineering, Osaka University, 2-1 Suita, Osaka 565-0871 (Japan); Sakagami, H. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Nagai, K. [Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuda 4259, Midori-ku, Yokohama 226-8503, Kanagawa (Japan)

    2016-06-15

    The interaction between ultra-intense laser light and vertically aligned carbon nanotubes is investigated to demonstrate efficient laser-energy absorption in the ps laser-pulse regime. Results indicate a clear enhancement of the energy conversion from laser to energetic electrons and a simultaneously small plasma expansion on the surface of the target. A two-dimensional plasma particle calculation exhibits a high absorption through laser propagation deep into the nanotube array, even for a dense array whose structure is much smaller than the laser wavelength. The propagation leads to the radial expansion of plasma perpendicular to the nanotubes rather than to the front side. These features may contribute to fast ignition in inertial confinement fusion and laser particle acceleration, both of which require high current and small surface plasma simultaneously.

  20. Examination of TL and optical absorption in calcite's mineral

    International Nuclear Information System (INIS)

    Sabikoglu, I.; Can, N.

    2009-01-01

    Calcite which is a form of crystalline of the calcium carbonate composes parent material of chalk stone (limestone) and marble. Calcite which presents in various colors also in our country consists of yellow, blue, transparent and green colors. In this study, green calcite mineral which is taken from the region of Ayvalik, was examined of its thermoluminescence (TL) and optical absorption features in different doses. It has been obtained a large TL peak in 179 degree C and absorption peak in 550 mm.

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

    Science.gov (United States)

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

    2014-09-01

    Acetaminophen (paracetamol) is a widely used nonopioid, non-NSAID analgesic that is effective against a variety of pain types, but the consequences of overdose can be severe. Because acetaminophen is so widely available as a single agent and is increasingly being formulated in fixed-ratio combination analgesic products for the potential additive or synergistic analgesic effect and/or reduced adverse effects, accidental cumulative overdose is an emergent concern. This has rekindled interest in the sites, processes, and pharmacokinetics of acetaminophen oral absorption and the clinical factors that can influence these. The absorption of oral acetaminophen occurs primarily along the small intestine by passive diffusion. Therefore, the rate-limiting step is the rate of gastric emptying into the intestines. Several clinical factors can affect absorption per se or the rate of gastric emptying, such as diet, concomitant medication, surgery, pregnancy, and others. Although acetaminophen does not have the abuse potential of opioids or the gastrointestinal bleeding or organ adverse effects of NSAIDs, excess amounts can produce serious hepatic injury. Thus, an understanding of the sites and features of acetaminophen absorption--and how they might be influenced by factors encountered in clinical practice--is important for pain management using this agent. It can also provide insight for design of formulations that would be less susceptible to clinical variables. © 2013 World Institute of Pain.

  2. Optical absorption in dendrimers

    International Nuclear Information System (INIS)

    Supritz, C.; Engelmann, A.; Reineker, P.

    2004-01-01

    Dendrimers are highly branched molecules, which are expected to be useful, for example, as efficient artificial light harvesting systems in nano-technological applications. There are two different classes of dendrimers: compact dendrimers with constant distance between neighboring branching points throughout the macromolecule and extended dendrimers, where this distance increases from the system periphery to the center. We investigate the linear absorption spectra of these dendrimer types using the Frenkel exciton concept. The electron-phonon interaction is taken into account by introducing a heat bath that interacts with the exciton in a stochastic manner

  3. MNC Knowledge Transfer, Subsidiary Absorptive Capacity and HRM

    DEFF Research Database (Denmark)

    Minbaeva, Dana; Pedersen, Torben; Björkman, Ingmar

    2014-01-01

    Based on a sample of 169 subsidiaries of multinational corporations (MNCs) operating in the USA, Russia, and Finland, this paper investigates the relationship between MNC subsidiary HRM practices, absorptive capacity and knowledge transfer. First, we examine the relationship between the application...... of specific HRM practices and the level of the absorptive capacity. Second, we suggest that absorptive capacity should be conceptualized as being comprised of both employees’ ability and motivation. Further, results indicate that both ability and motivation (absorptive capacity) are needed to facilitate...

  4. Geospatial Absorption and Regional Effects

    Directory of Open Access Journals (Sweden)

    IOAN MAC

    2009-01-01

    Full Text Available The geospatial absorptions are characterized by a specific complexity both in content and in their phenomenological and spatial manifestation fields. Such processes are differentiated according to their specificity to pre-absorption, absorption or post-absorption. The mechanisms that contribute to absorption are extremely numerous: aggregation, extension, diffusion, substitution, resistivity (resilience, stratification, borrowings, etc. Between these mechanisms frequent relations are established determining an amplification of the process and of its regional effects. The installation of the geographic osmosis phenomenon in a given territory (a place for example leads to a homogenization of the geospatial state and to the installation of the regional homogeneity.

  5. Constraining the Intergalactic and Circumgalactic Media with Lyman-Alpha Absorption

    Science.gov (United States)

    Sorini, Daniele; Onorbe, Jose; Hennawi, Joseph F.; Lukic, Zarija

    2018-01-01

    Lyman-alpha (Ly-a) absorption features detected in quasar spectra in the redshift range 02Mpc, the simulations asymptotically match the observations, because the ΛCDM model successfully describes the ambient IGM. This represents a critical advantage of studying the mean absorption profile. However, significant differences between the simulations, and between simulations and observations are present on scales 20kpc-2Mpc, illustrating the challenges of accurately modeling and resolving galaxy formation physics. It is noteworthy that these differences are observed as far out as ~2Mpc, indicating that the `sphere-of-influence' of galaxies could extend to approximately ~20 times the halo virial radius (~100kpc). Current observations are very precise on these scales and can thus strongly discriminate between different galaxy formation models. I demonstrate that the Ly-a absorption profile is primarily sensitive to the underlying temperature-density relationship of diffuse gas around galaxies, and argue that it thus provides a fundamental test of galaxy formation models. With near-future high-precision observations of Ly-a absorption, the tools developed in my thesis set the stage for even stronger constraints on models of galaxy formation and cosmology.

  6. PG 1700 + 518 - a low-redshift, broad absorption line QSO

    International Nuclear Information System (INIS)

    Pettini, M.; Boksenberg, A.

    1985-01-01

    The first high-resolution optical spectra and lower resolution UV spectra of PG 1700 + 518, the only known broad-absorption-line (BAL) QSO at low emission redshift (0.288) are presented. The optical data were obtained with the Isaac Newton Telescope on the island of La Palma and the UV data with the International Ultraviolet Explorer satellite. The outstanding feature of the optical spectrum is a strong, broad Mg II absorption trough, detached from the Mg II emission line and indicative of ejection velocities of between 7000 and 18,000 km/s. Also detected were narrow (FWHM = 350 km/s) Mg II absorption lines at absolute z = 0.2698, which are probably related to the mass ejection phenomenon. It is concluded that the emission-line spectrum is similar to that of other low-redshift QSOs although there are some obvious differences from typical BAL QSOs, most notably in the unusually low level of ionization of both emission-line and broad absorption line gas. 21 references

  7. Electromagnetic-radiation absorption by water

    Science.gov (United States)

    Lunkenheimer, P.; Emmert, S.; Gulich, R.; Köhler, M.; Wolf, M.; Schwab, M.; Loidl, A.

    2017-12-01

    Why does a microwave oven work? How does biological tissue absorb electromagnetic radiation? Astonishingly, we do not have a definite answer to these simple questions because the microscopic processes governing the absorption of electromagnetic waves by water are largely unclarified. This absorption can be quantified by dielectric loss spectra, which reveal a huge peak at a frequency of the exciting electric field of about 20 GHz and a gradual tailing off toward higher frequencies. The microscopic interpretation of such spectra is highly controversial and various superpositions of relaxation and resonance processes ascribed to single-molecule or molecule-cluster motions have been proposed for their analysis. By combining dielectric, microwave, THz, and far-infrared spectroscopy, here we provide nearly continuous temperature-dependent broadband spectra of water. Moreover, we find that corresponding spectra for aqueous solutions reveal the same features as pure water. However, in contrast to the latter, crystallization in these solutions can be avoided by supercooling. As different spectral contributions tend to disentangle at low temperatures, this enables us to deconvolute them when approaching the glass transition under cooling. We find that the overall spectral development, including the 20 GHz feature (employed for microwave heating), closely resembles the behavior known for common supercooled liquids. Thus water's absorption of electromagnetic waves at room temperature is not unusual but very similar to that of glass-forming liquids at elevated temperatures, deep in the low-viscosity liquid regime, and should be interpreted along similar lines.

  8. Electromagnetic-radiation absorption by water.

    Science.gov (United States)

    Lunkenheimer, P; Emmert, S; Gulich, R; Köhler, M; Wolf, M; Schwab, M; Loidl, A

    2017-12-01

    Why does a microwave oven work? How does biological tissue absorb electromagnetic radiation? Astonishingly, we do not have a definite answer to these simple questions because the microscopic processes governing the absorption of electromagnetic waves by water are largely unclarified. This absorption can be quantified by dielectric loss spectra, which reveal a huge peak at a frequency of the exciting electric field of about 20 GHz and a gradual tailing off toward higher frequencies. The microscopic interpretation of such spectra is highly controversial and various superpositions of relaxation and resonance processes ascribed to single-molecule or molecule-cluster motions have been proposed for their analysis. By combining dielectric, microwave, THz, and far-infrared spectroscopy, here we provide nearly continuous temperature-dependent broadband spectra of water. Moreover, we find that corresponding spectra for aqueous solutions reveal the same features as pure water. However, in contrast to the latter, crystallization in these solutions can be avoided by supercooling. As different spectral contributions tend to disentangle at low temperatures, this enables us to deconvolute them when approaching the glass transition under cooling. We find that the overall spectral development, including the 20 GHz feature (employed for microwave heating), closely resembles the behavior known for common supercooled liquids. Thus water's absorption of electromagnetic waves at room temperature is not unusual but very similar to that of glass-forming liquids at elevated temperatures, deep in the low-viscosity liquid regime, and should be interpreted along similar lines.

  9. 51Cr-ethylenediaminetetraacetic acid absorption test

    International Nuclear Information System (INIS)

    Aabakken, L.

    1989-01-01

    The 51 Cr-ethylenediaminetetraacetic acid (EDTA) absorption test was evaluated in 83 healthy, male volunteers. Base-line 24 h excretion after peroral administration ranged from 0.88% to 7.96%, with a higher median absorption than reported by most authors (2.45%). However, the reproducibility and stability of the method and the reproducibility of the results were satisfactory. Urinary excretion after intraduodenal installation (n=18) was comparable to that seen after peroral test dose administration, indicating a limited significance of gastric 51 Cr-EDTA absorption under normal conditions. In 16 subjects a single intake of alcohol immediately before the test gave a modest and short-lasting increase in 51 Cr-EDTA absorption. No correlation was seen to body mass index, creatinine clearance, urinary volume, or small-bowel transit time, possibly reducing the number of confounding factors in the evaluation of absorption data. A small but significant negative correlation was, however, found to body surface area and age

  10. Optical absorption in recycled waste plastic polyethylene

    Science.gov (United States)

    Aji, M. P.; Rahmawati, I.; Priyanto, A.; Karunawan, J.; Wati, A. L.; Aryani, N. P.; Susanto; Wibowo, E.; Sulhadi

    2018-03-01

    We investigated the optical properties of UV spectrum absorption in recycled waste plastic from polyethylene polymer type. Waste plastic polyethylene showed an optical spectrum absorption after it’s recycling process. Spectrum absorption is determined using spectrophotometer UV-Nir Ocean Optics type USB 4000. Recycling method has been processed using heating treatment around the melting point temperature of the polyethylene polymer that are 200°C, 220°C, 240°C, 260°C, and 280°C. In addition, the recycling process was carried out with time variations as well, which are 1h, 1.5h, 2h, and 2.5h. The result of this experiment shows that recycled waste plastic polyethylene has a spectrum absorption in the ∼ 340-550 nm wavelength range. The absorbance spectrum obtained from UV light which is absorbed in the orbital n → π* and the orbital π → π*. This process indicates the existence of electron transition phenomena. This mechanism is affected by the temperature and the heating time where the intensity of absorption increases and widens with the increase of temperature and heating time. Furthermore this study resulted that the higher temperature affected the enhancement of the band gap energy of waste plastic polyethylene. These results show that recycled waste plastic polyethylene has a huge potential to be absorber materials for solar cell.

  11. In vivo determination of the absorption and scattering spectra of the human prostate during photodynamic therapy

    Science.gov (United States)

    Finlay, Jarod C.; Zhu, Timothy C.; Dimofte, Andreea; Stripp, Diana C. H.; Malkowicz, S. B.; Whittington, Richard; Miles, Jeremy; Glatstein, Eli; Hahn, Stephen M.

    2004-06-01

    peak. Using our phantom data as a calibration, we have determined the pre-treatment MLu concentration to be approximately 2 to 8 mg kg-1. After PDT, the concentration is reduced to 1 to 2.5 mg kg-1, an indication of photobleaching induced by irradiation. In addition, absorption features corresponding to the oxygenated and deoxygenated forms of hemoglobin indicate a reduction in tissue oxygenation during treatment.

  12. Hydrolysis Batteries: Generating Electrical Energy during Hydrogen Absorption.

    Science.gov (United States)

    Xiao, Rui; Chen, Jun; Fu, Kai; Zheng, Xinyao; Wang, Teng; Zheng, Jie; Li, Xingguo

    2018-02-19

    The hydrolysis reaction of aluminum can be decoupled into a battery by pairing an Al foil with a Pd-capped yttrium dihydride (YH 2 -Pd) electrode. This hydrolysis battery generates a voltage around 0.45 V and leads to hydrogen absorption into the YH 2 layer. This represents a new hydrogen absorption mechanism featuring electrical energy generation during hydrogen absorption. The hydrolysis battery converts 8-15 % of the thermal energy of the hydrolysis reaction into usable electrical energy, leading to much higher energy efficiency compared to that of direct hydrolysis. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Spectrophotometry of six broad absorption line QSOs

    Science.gov (United States)

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

    1987-01-01

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

  14. Systematic review: Helicobacter pylori infection and impaired drug absorption.

    Science.gov (United States)

    Lahner, E; Annibale, B; Delle Fave, G

    2009-02-15

    Impaired acid secretion may affect drug absorption and may be consequent to corporal Helicobacter pylori-gastritis, which may affect the absorption of orally administered drugs. To focus on the evidence of impaired drug absorption associated with H. pylori infection. Data sources were the systematic search of MEDLINE/EMBASE/SCOPUS databases (1980-April 2008) for English articles using the keywords: drug malabsorption/absorption, stomach, Helicobacter pylori, gastritis, gastric acid, gastric pH, hypochlorhydria, gastric hypoacidity. Study selection was made from 2099 retrieved articles, five studies were identified. Data were extracted from selected papers, investigated drugs, study type, main features of subjects, study design, intervention type and results were extracted. In all, five studies investigated impaired absorption of l-dopa, thyroxine and delavirdine in H. pylori infection. Eradication treatment led to 21-54% increase in l-dopa in Parkinson's disease. Thyroxine requirement was higher in hypochlorhydric goitre with H. pylori-gastritis and thyrotropin levels decreased by 94% after treatment. In H. pylori- and HIV-positive hypochlorhydric subjects, delavirdine absorption increased by 57% with orange juice administration and by 150% after eradication. A plausible mechanism of impaired drug absorption is decreased acid secretion in H. pylori-gastritis patients. Helicobacter pylori infection and hypochlorhydria should be considered in prescribing drugs the absorption of which is potentially affected by intragastric pH.

  15. Atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Haswell, S.J.

    1991-01-01

    Atomic absorption spectroscopy is now well established and widely used technique for the determination of trace and major elements in a wide range analyte types. There have been many advances in the atomic spectroscopy over the last decade and for this reason and to meet the demand, it was felt that there was a need for an updated book. Whilst interest in instrumental design has tended to dominate the minds of the spectrocopist, the analyst concerned with obtaining reliable and representative data, in diverse areas of application, has been diligently modifying and developing sample treatment and instrumental introduction techniques. Such methodology is de fundamental part of analysis and form the basis of the fourteen application chapters of this book. The text focuses in the main on AAS; however, the sample handling techniques described are in many cases equally applicable to ICP-OES and ICP-MS analysis. (author). refs.; figs.; tabs

  16. Atomic absorption spectrophotometer

    International Nuclear Information System (INIS)

    Stockdale, T. J.

    1985-01-01

    In atomic absorption spectrophotometer, a reference path may be provided for radiation which excludes the flame. This radiation provides a signal from a detector which varies only with the instrumental drift produced by variations in the radiation source brightness and by variations in detector gain. The signal can be used to compensate for drift in other signals received through a sample path including the flame. In the present invention, radiation passes through the sample path continuously during measurement, and only through the reference path between sample measurements. Movable mirrors shift the radiation between the paths upon externally applied commands. Conveniently, the reference path measurement is made while the flame is stabilized during the change between samples. The reference path measurements are stored and used to correct for drift

  17. Analyzing Water's Optical Absorption

    Science.gov (United States)

    2002-01-01

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

  18. Detection of metal stress in boreal forest species using the 0.67-micron chlorophyll absorption band

    Science.gov (United States)

    Singhroy, Vernon H.; Kruse, Fred A.

    1991-01-01

    Several recent studies have shown that a shift of the red-edge inflection near 0.70 micron in vegetation reflectance spectra is an indicator of metal stress, partially attributable to changes in chlorophyll concentration. This 'red-edge shift', however, is difficult to detect and has been reported both toward longer (red) and shorter (blue) wavelengths. Our work demonstrates that direct measurement of the depth and width of the chlorophyll absorption band at 0.67 micron using digital feature extraction and absorption band characterization procedures developed for the analysis of mineral spectra is a more consistent indicator of metal stress. Additionally, the magnitude of these parameters is generally greater than that of the red edge shift and thus should be more amenable to detection and mapping using field and aircraft spectrometers.

  19. Atomic absorption spectrophotometry in perspective

    International Nuclear Information System (INIS)

    Soffiantini, V.

    1981-01-01

    Atomic absorption spectrophotometry is essentially an analytical technique used for quantitative trace metal analysis in a variety of materials. The speed and specificity of the technique is its greatest advantage over other analytical techniques. What atomic absorption spectrophotometry can and cannot do and its advantages and disadvantages are discussed, a summary of operating instructions are given, as well as a summary of analytical interferences. The applications of atomic absorption spectrophotometry are also shortly discussed

  20. Nonlinear effects in collective absorption

    International Nuclear Information System (INIS)

    Uenoyama, Takeshi; Mima, Kunioki; Watanabe, Tsuguhiro.

    1981-01-01

    The collective absorption of high intensity laser radiation is analyzed numerically. Density profile modification due to the ponderomotive force associating laser radiation and the excited electron plasma waves is self-consistently taken into account, and the intensity dependences of the absorption efficiency are obtained. In the high intensity regime, the absorption efficiency is found to be strongly enhanced in the plasma without flow, but reduced with supersonic flow. (author)

  1. Absorption by Spinning Dust: A Contaminant for High-redshift 21 cm Observations

    Science.gov (United States)

    Draine, B. T.; Miralda-Escudé, Jordi

    2018-05-01

    Spinning dust grains in front of the bright Galactic synchrotron background can produce a weak absorption signal that could affect measurements of high-redshift 21 cm absorption. At frequencies near 80 MHz where the Experiment to Detect the Global EoR Signature (EDGES) has reported 21 cm absorption at z≈ 17, absorption could be produced by interstellar nanoparticles with radii a≈ 50 \\mathringA in the cold interstellar medium (ISM), with rotational temperature T ≈ 50 K. Atmospheric aerosols could contribute additional absorption. The strength of the absorption depends on the abundance of such grains and on their dipole moments, which are uncertain. The breadth of the absorption spectrum of spinning dust limits its possible impact on measurement of a relatively narrow 21 cm absorption feature.

  2. X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

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

  3. Microwave absorptions of ultrathin conductive films and designs of frequency-independent ultrathin absorbers

    International Nuclear Information System (INIS)

    Li, Sucheng; Anwar, Shahzad; Lu, Weixin; Hang, Zhi Hong; Hou, Bo; Shen, Mingrong; Wang, Chin-Hua

    2014-01-01

    We study the absorption properties of ultrathin conductive films in the microwave regime, and find a moderate absorption effect which gives rise to maximal absorbance 50% if the sheet (square) resistance of the film meets an impedance matching condition. The maximal absorption exhibits a frequency-independent feature and takes place on an extremely subwavelength scale, the film thickness. As a realistic instance, ∼5 nm thick Au film is predicted to achieve the optimal absorption. In addition, a methodology based on metallic mesh structure is proposed to design the frequency-independent ultrathin absorbers. We perform a design of such absorbers with 50% absorption, which is verified by numerical simulations

  4. Quality indicators in radiotherapy

    International Nuclear Information System (INIS)

    Cionini, Luca; Gardani, Gianstefano; Gabriele, Pietro; Magri, Secondo; Morosini, Pier Luigi; Rosi, Antonella; Viti, Vincenza

    2007-01-01

    Background and purpose: There is a widespread and increasing tendency to develop hospital performance indicators in the field of accreditation/certification systems and quality benchmarking. A study has been undertaken to develop a set of performance indicators for a typical radiotherapy Centre and to evaluate their ability to provide a continuous quality improvement. Materials and methods: A working group consisting of radiation oncologists, medical physicists and radiation technologists under the coordination of experts in health technology assessment has elaborated a set of general indicators able to monitor performances and the quality level of a typical radiotherapy Centre. The work has been carried out through four steps: a preliminary set of indicators was selected; data on these indicators were collected in a number of Italian radiotherapy Centres and medical physics Services; problems in collection and analysis of data were discussed; a final set of indicators was developed. Results: A final set of 13 indicators is here presented. They concern general structural and/or operational features, health physics activities and accuracy and technical complexity of the treatment. Conclusions: The indicators tested in a few Italian Centres of radiotherapy and medical physics Services are now ready to be utilized by a larger community

  5. Galactic absorption line coronae

    International Nuclear Information System (INIS)

    Bregman, J.N.

    1981-01-01

    We have investigated whether gaseous coronae around galaxies rise to the absorption systems seen in quasar spectra. In our model, gas originally located in the disk is heated to the million degree range and rises to surround the galaxy; the gas remains bound to the galaxy. Optically thin radiative cooling drives a thermal instability in the hot gas which causes cool clouds (T 4 K) to condense out of the corona. These clouds, which follow ballistic trajectories back to the disk, are the absorption sites. A two-dimensional hydrodynamic code with radiative cooling was used to study the dynamics and thermodynamics of the corona as well as the position rate at which clouds form. Coupled to the code is a galaxy with two mass components, a disk (approx.10 11 M/sub sun/) and a dark halo (approx.10 12 M/sub sun/). In a model where the temperature at the base of the corona (in the disk) is 3 x 10 6 K, absorbing gas of column density NL> or approx. =10 18 cm 2 extends radially to 100 kpc (face-on orientation) and vertically to 60 Kpc (edge-on orientation). The total mass of gas required here (coronal plus cloud gas) is 1.4 x 10 10 M/sub sun/, while the minimum supernova heating rate is one supernova per 27 years. In two other models (base coronal temperatures of 0.50 x 10 6 K and 1 x 10 6 K), coronal gas rises from an extended gaseous disk (in the previous model, the gas comes from a typical gaseous disk approximately 15 kpc in extent). Here, column densities of 10 19 cm -2 out to a radius of 70 kpc (face-on orientation) are achieved with a total gas mass of 1.7 x 10 9 M/sub direct-product/ and 2.0 x 10 9 M/sub sun/ and minimum heating rates of approximately one supernova per 170 years and one supernova per 60 years

  6. Analysis of a solar powered absorption system

    International Nuclear Information System (INIS)

    Said, S.A.M.; El-Shaarawi, M.A.I.; Siddiqui, M.U.

    2015-01-01

    Highlights: • Conventional absorption system modified to increase COP. • Results indicated increase of 10% in COP due to dephlegmator heat recovery. • Results indicated increase of 8% in COP due to refrigerant storage unit. • Results indicated increase of 18% in COP due to combined effect of modifications. • Simulation results indicated a very good agreement with the measured results. - Abstract: Today, fossil fuel is the primary extensively used source of energy. However, its negative impact on the environment have forced the energy research continuity to seriously consider renewable sources of energy. Solar energy, in particular, has been the main focus in this regard because it is a source of clean energy and naturally available. This study presents the design and analysis of a solar powered absorption refrigeration system modified to increase its coefficient of performance (COP). The modifications include recovering of waste heat from a dephlegmator and utilization of a refrigerant storage unit. The simulation results indicate an increase of 10% in the COP of the conventional design using dephlegmator heat recovery and an increase of 8% in the COP of the conventional design due to the use of a refrigerant storage. The analysis for the combined effect of modifications indicates an increase of 18% in the COP compared to conventional design. Calculated values of coefficient of performance indicate a very good agreement with the ones obtained based on measurement

  7. Fluoride absorption: independence from plasma fluoride levels

    International Nuclear Information System (INIS)

    Whitford, G.M.; Williams, J.L.

    1986-01-01

    The concept that there are physiologic mechanisms to homeostatically regulate plasma fluoride concentrations has been supported by results in the literature suggesting an inverse relationship between plasma fluoride levels and the absorption of the ion from the gastrointestinal tract of the rat. The validity of the relationship was questioned because of possible problems in the experimental design. The present work used four different methods to evaluate the effect of plasma fluoride levels on the absorption of the ion in rats: (i) the percentage of the daily fluoride intake that was excreted in the urine; (ii) the concentration of fluoride in femur epiphyses; (iii) the net areas under the time-plasma fluoride concentration curves after intragastric fluoride doses; and (iv) the residual amounts or fluoride in the gastrointestinal tracts after the intragastric fluoride doses. None of these methods indicated that plasma fluoride levels influence the rate or the degree or fluoride absorption. It was concluded that, unless extremely high plasma fluoride levels are involved (pharmacologic or toxic doses), the absorption of the ion is independent of plasma levels. The results provide further evidence that plasma fluoride concentrations are not homeostatically regulated

  8. Enhanced Water Vapor Absorption within Tropospheric Clouds: A Partial Explanation for Anomalous Absorption

    Science.gov (United States)

    Crisp, David; Zuffada, Cinzia

    1996-01-01

    Comparisons between solar flux measurements and predictions obtained from theoretical radiative transfer models indicate that most of these models underestimate the globally averaged solar energy absorbed by cloudy atmospheres by up to 25Wm&sup-2;.The origin of this anomalous absorption has not yet been established, but it has been attributed to a variety of sources including oversimplified or missing physical processes in the existing models, uncertainties in the input data, and even measurement errors. We used a sophisticated atmospheric radiative transfer model to provide improved constraints on the physical processes that contribute to the absorption of solar radiation by Earth's atmosphere. The results are described herein.

  9. Gas in scattering media absorption spectroscopy - GASMAS

    Science.gov (United States)

    Svanberg, Sune

    2008-09-01

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

  10. Wave energy absorption by ducks

    OpenAIRE

    Kurniawan, Adi

    2017-01-01

    We study the absorption of wave energy by a single and multiple cam-shaped bodies referred to as ducks. Numerical models are developed under the assumptions of linear theory. We consider wave absorption by a single duck as well as by two lines of ducks meeting at an angle.

  11. Wave energy absorption by ducks

    DEFF Research Database (Denmark)

    Kurniawan, Adi

    2018-01-01

    We study the absorption of wave energy by a single and multiple cam-shaped bodies referred to as ducks. Numerical models are developed under the assumptions of linear theory. We consider wave absorption by a single duck as well as by two lines of ducks meeting at an angle....

  12. Atomic absorption instrument functional description

    International Nuclear Information System (INIS)

    Bystroff, R.I.; Boyle, W.G. Jr.; Barton, G.W. Jr.

    1976-01-01

    This report describes a proposed system for automating atomic absorption analysis. The system consists of two atomic absorption instruments and an automatic sampler that can be attached to either instrument. A computer program controls the sampling and gathers data. The program then uses the data to perform bookkeeping, data processing, and report writing

  13. Sublinear absorption in OCS gas

    International Nuclear Information System (INIS)

    Bogani, F.; Querzoli, R.; Ernst, K.

    1988-01-01

    Sublinear absorption in OCS gas has been experimentally studied in detail by means of an optoacustic technique and transmission measurements. The best fit of the results is obtained by a phenomenological model, that considers the process as the sum of one-and two-photon absorptions

  14. Optical absorption of irradiated carbohydrates

    International Nuclear Information System (INIS)

    Supe, A.A.; Tiliks, Yu.E.

    1994-01-01

    The optical absorption spectra of γ-irradiated carbohydrates (glucose, lactose, sucrose, maltose, and starch) and their aqueous solutions were studied. The comparison of the data obtained with the determination of the concentrations of molecular and radical products of radiolysis allows the absorption bands with maxima at 250 and 310 nm to be assigned to the radicals trapped in the irradiated carbohydrates

  15. Water absorption in brick masonry

    NARCIS (Netherlands)

    Brocken, H.J.P.; Smolders, H.R.

    1996-01-01

    The water absorption in brick, mortar that was cured separately, and masonry samples was studied using NMR. Models of the moisture transport are usually formulated on the basis of a diffusion equation. In the case of water absorption in separate brick and mortar samples, the moisture diffusivity in

  16. Multifunctional hybrids for electromagnetic absorption

    International Nuclear Information System (INIS)

    Huynen, I.; Quievy, N.; Bailly, C.; Bollen, P.; Detrembleur, C.; Eggermont, S.; Molenberg, I.; Thomassin, J.M.; Urbanczyk, L.

    2011-01-01

    Highlights: → EM absorption requires low dielectric constant and ∼1 S/m electrical conductivity. → New hybrids were processed with CNT-filled polymer foam inserted in Al honeycomb. → The EM absorption in the GHz range is superior to any known material. → A closed form model is used to guide the design of the hybrid. → The architectured material is light with potential for thermal management. - Abstract: Electromagnetic (EM) interferences are ubiquitous in modern technologies and impact on the reliability of electronic devices and on living cells. Shielding by EM absorption, which is preferable over reflection in certain instances, requires combining a low dielectric constant with high electrical conductivity, which are antagonist properties in the world of materials. A novel class of hybrid materials for EM absorption in the gigahertz range has been developed based on a hierarchical architecture involving a metallic honeycomb filled with a carbon nanotube-reinforced polymer foam. The waveguide characteristics of the honeycomb combined with the performance of the foam lead to unexpectedly large EM power absorption over a wide frequency range, superior to any known material. The peak absorption frequency can be tuned by varying the shape of the honeycomb unit cell. A closed form model of the EM reflection and absorption provides a tool for the optimization of the hybrid. This designed material sets the stage for a new class of sandwich panels combining high EM absorption with mass efficiency, stiffness and thermal management.

  17. Online feature selection with streaming features.

    Science.gov (United States)

    Wu, Xindong; Yu, Kui; Ding, Wei; Wang, Hao; Zhu, Xingquan

    2013-05-01

    We propose a new online feature selection framework for applications with streaming features where the knowledge of the full feature space is unknown in advance. We define streaming features as features that flow in one by one over time whereas the number of training examples remains fixed. This is in contrast with traditional online learning methods that only deal with sequentially added observations, with little attention being paid to streaming features. The critical challenges for Online Streaming Feature Selection (OSFS) include 1) the continuous growth of feature volumes over time, 2) a large feature space, possibly of unknown or infinite size, and 3) the unavailability of the entire feature set before learning starts. In the paper, we present a novel Online Streaming Feature Selection method to select strongly relevant and nonredundant features on the fly. An efficient Fast-OSFS algorithm is proposed to improve feature selection performance. The proposed algorithms are evaluated extensively on high-dimensional datasets and also with a real-world case study on impact crater detection. Experimental results demonstrate that the algorithms achieve better compactness and higher prediction accuracy than existing streaming feature selection algorithms.

  18. Exciton and biexciton signatures in femtosecond transient absorption of π-conjugated oligomers

    Science.gov (United States)

    Klimov, Victor I.; McBranch, Duncan W.; Barashkov, Nikolay N.; Ferraris, John P.

    1997-12-01

    We report femtosecond transient-absorption studies of a five-ring oligomer of polyphenylenevinylene prepared in two different forms: as solid-state films and dilute solutions. Both types of samples exhibit a photoinduced absorption (PA) band with dynamics which closely match those of the stimulated emission (SE), demonstrating unambiguously that these features originate from the same species, namely from intrachain singlet excitons. Photochemical degradation of the solid-state samples is demonstrated to dramatically shorten the SE dynamics above a moderate incident pump fluence, whereupon the dynamics of the SE and the long- wavelength PA no longer coincide. In contrast to solutions, solid-state films exhibit an additional short-wavelength PA band with pump-independent dynamics, indicating the efficient formation of non-emissive inter-chain excitons. Correlations in the subpicosecond dynamics of the two PA features, as well as the pump intensity-dependence provide strong evidence that the formation of inter-chain excitons is mediated by intrachain two-exciton states. At high pump levels, we see a clear indication of interaction between excited states also in dilute solutions. This is manifested as a superlinear pump-dependence and shortening of the decay dynamics of the SE. We attribute this behavior to the formation of biexcitons resulting from coherent interaction between two excitons on a single chain.

  19. Exciton and biexciton signatures in femotosecond transient absorption of {pi}-conjugated oligomers

    Energy Technology Data Exchange (ETDEWEB)

    Klimov, V.; McBranch, D. [Los Alamos National Lab., NM (United States); Barashkov, N.; Ferraris, J. [Univ. of Texas, Dallas, TX (United States)

    1997-10-01

    The authors report femotosecond transient-absorption studies of a five-ring oligomer of polyphenylenevinylene (PPV) prepared in two different forms: as solid-state films and dilute solutions. Both types of samples exhibit a photoinduced absorption (PA) band with dynamics which closely match those of the stimulated emission (SE), demonstrating unambiguously that these features originate from the same species, namely from intrachain singlet excitons. Photo-chemical degradation of the solid-state samples is demonstrated to dramatically shorten the SE dynamics above a moderate incident pump fluence, whereupon the dynamics of the SE and the long-wavelength PA no longer coincide. In contrast to solutions, solid-state films exhibit an additional short-wavelength PA band with pump-independent dynamics, indicating the efficient formation of non-emissive inter-chain excitons. Correlations in the subpicosecond dynamics of the two PA features, as well as the pump intensity-dependence provide strong evidence that the formation of inter-chain excitons is mediated by intrachain two-exciton states. At high pump levels, the authors see a clear indication of interaction between excited states also in dilute solutions. This is manifested as a superlinear pump-dependence and shortening of the decay dynamics of the SE. They attribute this behavior to the formation of biexcitons resulting from coherent interaction between two excitons on a single chain.

  20. Absorption technology for solar and waste heat utilization

    International Nuclear Information System (INIS)

    Grossman, G.

    1993-01-01

    Absorption heat pumps, first developed in the 19th century, have received renewed and growing attention in the past two decades. With the increasing cost of oil and electricity, the particular features of this heat-powered cycle have made it attractive for both residential and industrial applications. Solar-powered air conditioning, gas-fired domestic cooling and waste-heat-powered temperature boosters are some of the applications on which intensive research and development has been conducted. This paper describes the operation of absorption systems and discusses several practical applications. It surveys recent advances in absorption technology, including the selection of working fluids, cycle improvements and multi-staging, and fundamentals of the combined heat and mass transfer in absorption processes. (author)

  1. Electrically tunable coherent optical absorption in graphene with ion gel.

    Science.gov (United States)

    Thareja, Vrinda; Kang, Ju-Hyung; Yuan, Hongtao; Milaninia, Kaveh M; Hwang, Harold Y; Cui, Yi; Kik, Pieter G; Brongersma, Mark L

    2015-03-11

    We demonstrate electrical control over coherent optical absorption in a graphene-based Salisbury screen consisting of a single layer of graphene placed in close proximity to a gold back reflector. The screen was designed to enhance light absorption at a target wavelength of 3.2 μm by using a 600 nm-thick, nonabsorbing silica spacer layer. An ionic gel layer placed on top of the screen was used to electrically gate the charge density in the graphene layer. Spectroscopic reflectance measurements were performed in situ as a function of gate bias. The changes in the reflectance spectra were analyzed using a Fresnel based transfer matrix model in which graphene was treated as an infinitesimally thin sheet with a conductivity given by the Kubo formula. The analysis reveals that a careful choice of the ionic gel layer thickness can lead to optical absorption enhancements of up to 5.5 times for the Salisbury screen compared to a suspended sheet of graphene. In addition to these absorption enhancements, we demonstrate very large electrically induced changes in the optical absorption of graphene of ∼3.3% per volt, the highest attained so far in a device that features an atomically thick active layer. This is attributable in part to the more effective gating achieved with the ion gel over the conventional dielectric back gates and partially by achieving a desirable coherent absorption effect linked to the presence of the thin ion gel that boosts the absorption by 40%.

  2. Relative absorption and dermal loading of chemical substances: Consequences for risk assessment

    NARCIS (Netherlands)

    Buist, H.E.; Schaafsma, G.; Sandt, J.J.M. van de

    2009-01-01

    Quantification of skin absorption is an essential step in reducing the uncertainty of dermal risk assessment. Data from literature indicate that the relative dermal absorption of substances is dependent on dermal loading. Therefore, an internal exposure calculated with absorption data determined at

  3. Light absorption and scattering mechanisms in laser fusion plasmas

    International Nuclear Information System (INIS)

    Barnes, C.; Estabrook, K.G.; Kruer, W.L.; Langdon, A.B.; Lasinski, B.F.; Max, C.E.; Randall, C.; Thomson, J.J.

    1977-01-01

    The picture of laser light absorption and scattering which is emerging from theory and computer simulation studies of laser-plasma interactions is described. On the subject of absorption, we discuss theoretical and experimental evidence that resonance absorption in a steepened density profile is a dominant absorption mechanism. Recent work also indicates the presence of critical surface ripples, which we study using two and three dimensional computer simulations. Predictions of hot electron spectra due to resonance absorption are described, as are effects of plasma outflow. We then discuss two regimes where stimulated scattering may occur. Brillouin scattering is expected in the underdense target blow-off, for long laser pulses, and is limited by ion heating. Raman scattering in the background gas of a reactor target chamber is predicted to be at most a 10 percent effect for 1 μm lasers

  4. Theory of strong-field attosecond transient absorption

    International Nuclear Information System (INIS)

    Wu, Mengxi; Chen, Shaohao; Camp, Seth; Schafer, Kenneth J; Gaarde, Mette B

    2016-01-01

    Attosecond transient absorption is one of the promising new techniques being developed to exploit the availability of sub-femtosecond extreme ultraviolet (XUV) pulses to study the dynamics of the electron on its natural time scale. The temporal resolution in a transient absorption setup comes from the control of the relative delay and coherence between pump and probe pulses, while the spectral resolution comes from the characteristic width of the features that are being probed. In this review we focus on transient absorption scenarios where an attosecond pulse of XUV radiation creates a broadband excitation that is subsequently probed by a few cycle infrared (IR) laser. Because the attosecond XUV pulses are locked to the IR field cycle, the exchange of energy in the laser–matter interaction can be studied with unprecedented precision. We focus on the transient absorption by helium atoms of XUV radiation around the first ionization threshold, where we can simultaneoulsy solve the time-dependent Schrödinger equation for the single atom response and the Maxwell wave equation for the collective response of the nonlinear medium. We use a time-domain method that allows us to treat on an equal footing all the different linear and nonlinear processes by which the medium can exchange energy with the fields. We present several simple models, based on a few-level system interacting with a strong IR field, to explain many of the novel features found in attosecond transient absorption spectrograms. These include the presence of light-induced states, which demonstrate the ability to probe the dressed states of the atom. We also present a time-domain interpretation of the resonant pulse propagation features that appear in absorption spectra in dense, macroscopic media. We close by reviewing several recent experimental results that can be explained in terms of the models we discuss. Our aim is to present a road map for understanding future attosecond transient absorption

  5. Hyperspectral image classifier based on beach spectral feature

    International Nuclear Information System (INIS)

    Liang, Zhang; Lianru, Gao; Bing, Zhang

    2014-01-01

    The seashore, especially coral bank, is sensitive to human activities and environmental changes. A multispectral image, with coarse spectral resolution, is inadaptable for identify subtle spectral distinctions between various beaches. To the contrary, hyperspectral image with narrow and consecutive channels increases our capability to retrieve minor spectral features which is suit for identification and classification of surface materials on the shore. Herein, this paper used airborne hyperspectral data, in addition to ground spectral data to study the beaches in Qingdao. The image data first went through image pretreatment to deal with the disturbance of noise, radiation inconsistence and distortion. In succession, the reflection spectrum, the derivative spectrum and the spectral absorption features of the beach surface were inspected in search of diagnostic features. Hence, spectra indices specific for the unique environment of seashore were developed. According to expert decisions based on image spectrums, the beaches are ultimately classified into sand beach, rock beach, vegetation beach, mud beach, bare land and water. In situ surveying reflection spectrum from GER1500 field spectrometer validated the classification production. In conclusion, the classification approach under expert decision based on feature spectrum is proved to be feasible for beaches

  6. Absorption band Q model for the earth

    International Nuclear Information System (INIS)

    Anderson, D.L.; Given, J.W.

    1982-01-01

    Body wave, surface wave, and normal mode data are used to place constraints on the frequency dependence of Q in the mantle. With a simple absorption band model it is possible to satisfy the shear sensitive data over a broad frequency range. The quality factor Q/sub s/(ω) is proportional to ω/sup α/ in the band and to ω and ω -1 at higher and lower frequencies, respectively, as appropriate for a relaxation mechanism with a spectrum of relaxation time. The parameters of the band are Q(min) = 80, α = 0.15, and width, 5 decades. The center of the band varies from 10 1 seconds in the upper mantle, to 1.6 x 10 3 seconds in the lower mantle. The shift of the band with depth is consistent with the expected effects of temperature, pressure and stress. High Q, regions of the mantle are attributed to a shift of the absorption band to longer periods. To satisfy the gravest fundamental spheroidal modes and the ScS data, the absorption band must shift back into the short-period seismic band at the base of the mantle. This may be due to a high temperature gradient or high shear stresses. A preliminary attempt is also made to specify bulk dissipation in the mantle and core. Specific features of the absorption band model are low Q in the body wave band at both the top and the base of the mantle, low Q for long-period body waves in the outer core, an inner core Q 2 that increases with period, and low Q/sub p//Q/sub s/ at short periods in the middle mantel. The short-period Q/sub s/ increases rapidly at 400 km and is relatively constant from this depth to 2400 km. The deformational Q of the earth at a period of 14 months is predicted to be 463

  7. Identifying significant environmental features using feature recognition.

    Science.gov (United States)

    2015-10-01

    The Department of Environmental Analysis at the Kentucky Transportation Cabinet has expressed an interest in feature-recognition capability because it may help analysts identify environmentally sensitive features in the landscape, : including those r...

  8. Decision trees to characterise the roles of permeability and solubility on the prediction of oral absorption

    OpenAIRE

    Newby, Danielle; Freitas, Alex. A.; Ghafourian, Taravat

    2015-01-01

    Oral absorption of compounds depends on many physiological, physiochemical and formulation factors. Two important properties that govern oral absorption are in vitro permeability and solubility, which are commonly used as indicators of human intestinal absorption. Despite this, the nature and exact characteristics of the relationship between these parameters are not well understood. In this study a large dataset of human intestinal absorption was collated along with in vitro permeability, aqu...

  9. Sabine absorption coefficients to random incidence absorption coefficients

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho

    2014-01-01

    into random incidence absorption coefficients for porous absorbers are investigated. Two optimization-based conversion methods are suggested: the surface impedance estimation for locally reacting absorbers and the flow resistivity estimation for extendedly reacting absorbers. The suggested conversion methods...

  10. Absorption factor for cylindrical samples

    International Nuclear Information System (INIS)

    Sears, V.F.

    1984-01-01

    The absorption factor for the scattering of X-rays or neutrons in cylindrical samples is calculated by numerical integration for the case in which the absorption coefficients of the incident and scattered beams are not equal. An extensive table of values having an absolute accuracy of 10 -4 is given in a companion report [Sears (1983). Atomic Energy of Canada Limited, Report No. AECL-8176]. In the present paper an asymptotic expression is derived for the absorption factor which can be used with an error of less than 10 -3 for most cases of interest in both neutron inelastic scattering and neutron diffraction in crystals. (Auth.)

  11. The distribution of absorptive power dissipation in irradiated nanoparticulate system

    International Nuclear Information System (INIS)

    Li, Jiayu; Yang, Jian; Gu, Xiaobing

    2016-01-01

    The knowledge of local radiant absorption is important to the nanostructure optimization, it is beneficial to the applications in energy harvesting, optical heating, photocatalysis, etc. In this paper, FDTD model is constructed for the distribution of absorptive power dissipation in irradiated nanoparticulate system. The theoretical model extended from Mie theory is used to examine the FDTD model, the parameters and conditions set for FDTD simulation are confirmed based on the comparison. Then, the influence of Ag nanoparticle on the absorptive properties of nearby TiO_2 nanoparticle is investigated by FDTD simulation at the wavelength of 0.25 μm. It is indicated that suitable distance between TiO_2 and Ag particles is beneficial to the spectral radiant absorption of TiO_2 particle. Considering the agglomeration of nanoparticles and the oxidation at the TiO_2–Ag interface, the Ag core coated with Al_2O_3 shell is suggested, and the simulated results indicated that the shell thickness and the Ag core size need to be optimized for enhancing the radiant absorption of TiO_2 particle. - Highlights: • The absorptive power distribution in nanoparticulate system is simulated by FDTD. • FDTD simulation is compared with theoretical model extended from Mie theory. • The parameters and conditions are confirmed based on the comparison. • The influence of Ag nanoparticle on nearby TiO_2 particle's absorption is analyzed.

  12. Modelling absorption and photoluminescence of TPD

    Energy Technology Data Exchange (ETDEWEB)

    Vragovic, Igor [Dpto. de Fisica Aplicada and Inst. Universitario de Materiales de Alicante, Universidad de Alicante, E-03080 Alicante (Spain)], E-mail: igor.vragovic@ua.es; Calzado, Eva M.; Diaz Garcia, Maria A.; Himcinschi, C. [Max-Planck-Institut fuer Mikrostrukturphysik, D-06120 Halle (Germany); Gisslen, L.; Scholz, R. [Walter Schottky Institut, Technische Universitaet Muenchen, D-85748 Garching (Germany)

    2008-05-15

    We analyse the optical spectra of N,N{sup '}-diphenyl-N,N{sup '}-bis(3-methyl-phenyl)-(1,1{sup '}-biphenyl)-4,4{sup '}-diamine (TPD) doped polystyrene films. The aim of the present paper is to give a microscopic interpretation of the significant Stokes shift between absorption and photoluminescence, which makes this material suitable for stimulated emission. The optimized geometric structures and energies of a neutral TPD monomer in ground and excited states are obtained by ab initio calculations using Hartree-Fock and density functional theory. The results indicate that the second distinct peak observed in absorption may arise either from a group of higher electronic transitions of the monomer or from the lowest optical transitions of a TPD dimer.

  13. Modelling absorption and photoluminescence of TPD

    International Nuclear Information System (INIS)

    Vragovic, Igor; Calzado, Eva M.; Diaz Garcia, Maria A.; Himcinschi, C.; Gisslen, L.; Scholz, R.

    2008-01-01

    We analyse the optical spectra of N,N ' -diphenyl-N,N ' -bis(3-methyl-phenyl)-(1,1 ' -biphenyl)-4,4 ' -diamine (TPD) doped polystyrene films. The aim of the present paper is to give a microscopic interpretation of the significant Stokes shift between absorption and photoluminescence, which makes this material suitable for stimulated emission. The optimized geometric structures and energies of a neutral TPD monomer in ground and excited states are obtained by ab initio calculations using Hartree-Fock and density functional theory. The results indicate that the second distinct peak observed in absorption may arise either from a group of higher electronic transitions of the monomer or from the lowest optical transitions of a TPD dimer

  14. Cosmological Evolution of QSO Absorption Systems

    Science.gov (United States)

    Stengler-Larrea, Erik

    1995-08-01

    First, the evolution with cosmic time of the hydrogen clouds which produce the Lyman-alpha absorption lines is studied in dependence on the strength of these lines. From the analysis it is concluded that the results show no evidence of a dependence in the sense of stronger lines evolving faster, although for the resolution at which the used observations were done, it can not be ruled out. Within the same analysis, a distribution of the Doppler parameter of the lines was obtained, with large values and a wide spread. This parameter being an indicator of the gas temperature, this result is in accordance with high temperatures and, consequently, large ionised fractions and a large fraction of the baryonic matter of the universe being associated with these clouds. However, recent high resolution studies seem to reveal that much lower temperatures are characteristic of the clouds. The main content of this thesis, however, focuses on the redshift evolution of the absorbing systems producing absorption at the Lyman limit and of the amount of CIV producing CIV absorption lines. Regarding the CIV absorbers, previous predictions on the effects underlying their redshift distribution pointed to an increase with redshift of the absorbing column densities. In this thesis the first direct measurements of such column densities by profile fitting of a large number of absorption systems (73) are presented, confirming the predictions of a decrease of at least a factor of 3 between z=1.5 and z=3.0. The study on the evolution of Lyman limit absorption systems (LLSs) puts an end to previous discrepancies between the results of different groups. Both a smooth single power law dependence of the LLS number density on redshift indicating no evolution in number density for 0.4 Team of the HST Key Project on QSO absorption lines, and in particular to estimate the necessary exposure times, the magnitudes of several of these objects had to be re-measured. The acquisition of their images and the

  15. Health indicators 1991.

    Science.gov (United States)

    Dawson, N

    1991-01-01

    This is the second edition of a database developed by the Canadian Centre for Health Information (CCHI). It features 49 health indicators, under one cover containing the most recent data available from a variety of national surveys. This information may be used to establish health goals for the population and to offer objective measures of their success. The database can be accessed through CANSIM, Statistics Canada's socio-economic electronic database and retrieval system, or through a personal computer package which enables the user to retrieve and analyze the 1.2 million data points in the system.

  16. Molecular environment of iodine in naturally iodinated humic substances: Insight from X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Schlegel, Michel L.; Mercier-Bion, Florence; Barre, Nicole; Reiller, Pascal; Moulin, Valerie

    2006-01-01

    The molecular environment of iodine in reference inorganic and organic compounds, and in dry humic and fulvic acids (HAs and FAs) extracted from subsurface and deep aquifers was probed by iodine L-3-edge X-ray absorption spectroscopy. The X-ray absorption near-edge structure (XANES) of iodine spectra from HAs and FAs resembled those of organic references and displayed structural features consistent with iodine forming covalent bonds with organic molecules. Simulation of XANES spectra by linear combination of reference spectra suggested the predominance of iodine forming covalent bonds to aromatic rings (aromatic-bound iodine). Comparison of extended X-ray absorption fine structure (EXAFS) spectra of reference and samples further showed that iodine was surrounded by carbon shells at distances comparable to those for references containing aromatic-bound iodine. Quantitative analysis of EXAFS spectra indicated that iodine was bound to about one carbon at a distance d(I-C) of 2.01(4)-2.04(9) angstrom, which was comparable to the distances observed for aromatic-bound iodine in references (1.99(1)-2.07(6) angstrom), and significantly shorter than that observed for aliphatic-bound iodine (2.15(2)-2.16(2) angstrom). These results are in agreement with previous conclusions from X-ray photoelectron spectroscopy and from electro-spray ionization mass spectrometry. These results collectively suggest that the aromatic-bound iodine is stable in the various aquifers of this study. (authors)

  17. Broad Absorption Line Quasar catalogues with Supervised Neural Networks

    International Nuclear Information System (INIS)

    Scaringi, Simone; Knigge, Christian; Cottis, Christopher E.; Goad, Michael R.

    2008-01-01

    We have applied a Learning Vector Quantization (LVQ) algorithm to SDSS DR5 quasar spectra in order to create a large catalogue of broad absorption line quasars (BALQSOs). We first discuss the problems with BALQSO catalogues constructed using the conventional balnicity and/or absorption indices (BI and AI), and then describe the supervised LVQ network we have trained to recognise BALQSOs. The resulting BALQSO catalogue should be substantially more robust and complete than BI-or AI-based ones.

  18. Measurement of Electronic States of PbS Nanocrystal Quantum Dots Using Scanning Tunneling Spectroscopy: The Role of Parity Selection Rules in Optical Absorption

    Science.gov (United States)

    Diaconescu, Bogdan; Padilha, Lazaro A.; Nagpal, Prashant; Swartzentruber, Brian S.; Klimov, Victor I.

    2013-03-01

    We study the structure of electronic states in individual PbS nanocrystal quantum dots by scanning tunneling spectroscopy (STS) using one-to-two monolayer nanocrystal films treated with 1, 2-ethanedithiols (EDT). Up to six individual valence and conduction band states are resolved for a range of quantum dot sizes. The measured states’ energies are in good agreement with calculations using the k·p four-band envelope function formalism. A comparison of STS and optical absorption spectra indicates that some of the absorption features can only be explained by asymmetric transitions involving the states of different symmetries (e.g., S and P or P and D), which points towards the relaxation of the parity selection rules in these nanostructures. STS measurements also reveal a midgap feature, which is likely similar to one observed in previous charge transport studies of EDT-treated quantum dot films.

  19. GMRT Detection of HI 21 cm Associated Absorption towards the z ...

    Indian Academy of Sciences (India)

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

    Comparison of the radio and deep optical images .... Astronomical Image Processing System (AIPS) following standard procedures. About .... exhibits an HI absorption spectrum similar to that seen in 3C 190, viz., a broad shallow feature and ...

  20. Extreme Variability in a Broad Absorption Line Quasar

    Energy Technology Data Exchange (ETDEWEB)

    Stern, Daniel; Jun, Hyunsung D. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Mail Stop 169-221, Pasadena, CA 91109 (United States); Graham, Matthew J.; Djorgovski, S. G.; Donalek, Ciro; Drake, Andrew J.; Mahabal, Ashish A.; Steidel, Charles C. [California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125 (United States); Arav, Nahum; Chamberlain, Carter [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Barth, Aaron J. [Department of Physics and Astronomy, 4129 Frederick Reines Hall, University of California, Irvine, CA 92697 (United States); Glikman, Eilat, E-mail: daniel.k.stern@jpl.nasa.gov [Department of Physics, Middlebury College, Middlebury, VT 05753 (United States)

    2017-04-20

    CRTS J084133.15+200525.8 is an optically bright quasar at z = 2.345 that has shown extreme spectral variability over the past decade. Photometrically, the source had a visual magnitude of V ∼ 17.3 between 2002 and 2008. Then, over the following five years, the source slowly brightened by approximately one magnitude, to V ∼ 16.2. Only ∼1 in 10,000 quasars show such extreme variability, as quantified by the extreme parameters derived for this quasar assuming a damped random walk model. A combination of archival and newly acquired spectra reveal the source to be an iron low-ionization broad absorption line quasar with extreme changes in its absorption spectrum. Some absorption features completely disappear over the 9 years of optical spectra, while other features remain essentially unchanged. We report the first definitive redshift for this source, based on the detection of broad H α in a Keck/MOSFIRE spectrum. Absorption systems separated by several 1000 km s{sup −1} in velocity show coordinated weakening in the depths of their troughs as the continuum flux increases. We interpret the broad absorption line variability to be due to changes in photoionization, rather than due to motion of material along our line of sight. This source highlights one sort of rare transition object that astronomy will now be finding through dedicated time-domain surveys.

  1. The coupled effect of fiber volume fraction and void fraction on hydraulic fluid absorption of quartz/BMI laminates

    Science.gov (United States)

    Hurdelbrink, Keith R.; Anderson, Jacob P.; Siddique, Zahed; Altan, M. Cengiz

    2016-03-01

    Bismaleimide (BMI) resin with quartz (AQ581) fiber reinforcement is a composite material frequently used in aerospace applications, such as engine cowlings and radomes. Various composite components used in aircrafts are exposed to different types of hydraulic fluids, which may lead to anomalous absorption behavior over the service life of the composite. Accurate predictive models for absorption of liquid penetrants are particularly important as the composite components are often exposed to long-term degradation due to absorbed moisture, hydraulic fluids, or similar liquid penetrants. Microstructural features such as fiber volume fraction and void fraction can have a significant effect on the absorption behavior of fiber-reinforced composites. In this paper, hydraulic fluid absorption characteristics of quartz/BMI laminates fabricated from prepregs preconditioned at different relative humidity and subsequently cured at different pressures are presented. The composite samples are immersed into hydraulic fluid at room temperature, and were not subjected to any prior degradation. To generate process-induced microvoids, prepregs were conditioned in an environmental chamber at 2% or 99% relative humidity at room temperature for a period of 24 hours prior to laminate fabrication. To alter the fiber volume fraction, the laminates were fabricated at cure pressures of 68.9 kPa (10 psi) or 482.6 kPa (70 psi) via a hot-press. The laminates are shown to have different levels of microvoids and fiber volume fractions, which were observed to affect the absorption dynamics considerably and exhibited clear non-Fickian behavior. A one-dimensional hindered diffusion model (HDM) was shown to be successful in predicting the hydraulic fluid absorption. Model prediction indicates that as the fabrication pressure increased from 68.9 kPa to 482.6 kPa, the maximum fluid content (M∞) decreased from 8.0% wt. to 1.0% wt. The degree of non-Fickian behavior, measured by hindrance coefficient (

  2. OZONE ABSORPTION IN RAW WATERS

    Directory of Open Access Journals (Sweden)

    LJILJANA TAKIĆ

    2008-03-01

    Full Text Available The ozone absorption in raw water entering the main ozonization step at the Belgrade drinking water supply plant was investigated in a continuous stirred tank reactor (CSTR. A slow chemical reaction rate of dissolved ozone and pollutants present in raw water have been experimentally determined. The modified Hatta number was defined and calculated as a criterion which determines whether and to which extent the reactions of ozone and pollutants influence the rate of the pure physical ozone absorption.

  3. Microwaves absorption in superconducting materials

    International Nuclear Information System (INIS)

    Biasi, R.S. de; Fernandes, A.A.R.; Pereira, R.F.R.

    1989-01-01

    Microwaves absorption measures in two superconductors ceramics systems, Y-Ba-Cu-O and Bi-Sr-Ca-Cu-O are compared with similars datas obtained in the same band of temperature by a conventional method, mutual inductance. The results suggest that the microwaves absorption can be used as single and non-destructive method for investigating the properties of ceramics superconductors. (C.G.C.) [pt

  4. Ultrasonic absorption in solid specimens

    International Nuclear Information System (INIS)

    Siwabessy, P.J. W.; Stewart, G.A.

    1996-01-01

    As part of a project to measure the absorption of high frequency (50 - 500 kHz) sonar signals in warm sea-water, a laboratory apparatus has been constructed and tested against room temperature distilled water and various solutions of MgSO 4 (chemical relaxation of MgSO 4 is the major contribution to absorption below 200 kHz). The technique involves monitoring the decay of an acoustic signal for different sizes of vessels of water suspended in an evacuated chamber. So far, all containing vessels used have been spherical in shape. Extrapolation of the results to infinite volume yields the absorption due to the water alone. In order to accommodate variations in temperature and pressure, and to make the system more robust (e.g. for ship deck usage), it is desirable to employ stainless steel vessels. However, it was found that the quality of the data was greatly improved when pyrex glass spheres were used. The stainless steel spheres were manufactured by welding together mechanically spun hemispheres. The linear frequency dependence characteristic of acoustic absorption in solids was observed (in contrast to the quadratic frequency dependence of acoustic absorption in water), and the acoustic absorption was found to depend strongly on the thermal history of the steel

  5. Scramjet Performance Assessment Using Water Absorption Diagnostics (U)

    Science.gov (United States)

    Cavolowsky, John A.; Loomis, Mark P.; Deiwert, George

    1995-01-01

    Simultaneous multiple path measurements of temperature and H2O concentration will be presented for the AIMHYE test entries in the NASA Ames 16-Inch Shock Tunnel. Monitoring the progress of high temperature chemical reactions that define scramjet combustor efficiencies is a task uniquely suited to nonintrusive optical diagnostics. One application strategy to overcome the many challenges and limitations of nonintrusive measurements is to use laser absorption spectroscopy coupled with optical fibers. Absorption spectroscopic techniques with rapidly tunable lasers are capable of making simultaneous measurements of mole fraction, temperature, pressure, and velocity. The scramjet water absorption diagnostic was used to measure combustor efficiency and was compared to thrust measurements using a nozzle force balance and integrated nozzle pressures to develop a direct technique for evaluating integrated scramjet performance. Tests were initially performed with a diode laser tuning over a water absorption feature at 1391.7 nm. A second diode laser later became available at a wavelength near 1343.3 nm covering an additional water absorption feature and was incorporated in the system for a two-wavelength technique. Both temperature and mole fraction can be inferred from the lineshape analysis using this approach. Additional high temperature spectroscopy research was conducted to reduce uncertainties in the scramjet application. The lasers are optical fiber coupled to ports at the combustor exit and in the nozzle region. The output from the two diode lasers were combined in a single fiber, and the resultant two-wavelength beam was subsequently split into four legs. Each leg was directed through 60 meters of optical fiber to four combustor exit locations for measurement of beam intensity after absorption by the water within the flow. Absorption results will be compared to 1D combustor analysis using RJPA and nozzle CFD computations as well as to data from a nozzle metric

  6. Absorption dynamics and delay time in complex potentials

    Science.gov (United States)

    Villavicencio, Jorge; Romo, Roberto; Hernández-Maldonado, Alberto

    2018-05-01

    The dynamics of absorption is analyzed by using an exactly solvable model that deals with an analytical solution to Schrödinger’s equation for cutoff initial plane waves incident on a complex absorbing potential. A dynamical absorption coefficient which allows us to explore the dynamical loss of particles from the transient to the stationary regime is derived. We find that the absorption process is characterized by the emission of a series of damped periodic pulses in time domain, associated with damped Rabi-type oscillations with a characteristic frequency, ω = (E + ε)/ℏ, where E is the energy of the incident waves and ‑ε is energy of the quasidiscrete state of the system induced by the absorptive part of the Hamiltonian; the width γ of this resonance governs the amplitude of the pulses. The resemblance of the time-dependent absorption coefficient with a real decay process is discussed, in particular the transition from exponential to nonexponential regimes, a well-known feature of quantum decay. We have also analyzed the effect of the absorptive part of the potential on the dynamical delay time, which behaves differently from the one observed in attractive real delta potentials, exhibiting two regimes: time advance and time delay.

  7. Absorption and scattering of light by small particles

    CERN Document Server

    Bohren, Craig F

    1983-01-01

    Absorption and Scattering of Light by Small Particles. Treating absorption and scattering in equal measure, this self-contained, interdisciplinary study examines and illustrates how small particles absorb and scatter light. The authors emphasize that any discussion of the optical behavior of small particles is inseparable from a full understanding of the optical behavior of the parent material-bulk matter. To divorce one concept from the other is to render any study on scattering theory seriously incomplete. Special features and important topics covered in this book include:. * Classical theor

  8. Photoionization-driven Absorption-line Variability in Balmer Absorption Line Quasar LBQS 1206+1052

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Luming; Zhou, Hongyan; Ji, Tuo; Jiang, Peng; Liu, Bo; Pan, Xiang; Shi, Xiheng; Zhang, Shaohua [Polar Research Institute of China, 451 Jinqiao Road, Shanghai (China); Liu, Wenjuan; Wang, Jianguo [Yunnan Observatories, Chinese Academy of Sciences, Kunming, Yunnan (China); Wang, Tinggui; Yang, Chenwei [Department of Astronomy, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui (China); Miller, Lauren P., E-mail: lmsun@mail.ustc.edu.cn [Lehigh University, 27 Memorial Drive West, Bethlehem, PA 18015 (United States)

    2017-04-01

    In this paper we present an analysis of absorption-line variability in mini-BAL quasar LBQS 1206+1052. The Sloan Digital Sky Survey spectrum demonstrates that the absorption troughs can be divided into two components of blueshift velocities of ∼700 and ∼1400 km s{sup −1} relative to the quasar rest frame. The former component shows rare Balmer absorption, which is an indicator of high-density absorbing gas; thus, the quasar is worth follow-up spectroscopic observations. Our follow-up optical and near-infrared spectra using MMT, YFOSC, TSpec, and DBSP reveal that the strengths of the absorption lines vary for both components, while the velocities do not change. We reproduce all of the spectral data by assuming that only the ionization state of the absorbing gas is variable and that all other physical properties are invariable. The variation of ionization is consistent with the variation of optical continuum from the V -band light curve. Additionally, we cannot interpret the data by assuming that the variability is due to a movement of the absorbing gas. Therefore, our analysis strongly indicates that the absorption-line variability in LBQS 1206+1052 is photoionization driven. As shown from photoionization simulations, the absorbing gas with blueshift velocity of ∼700 km s{sup −1} has a density in the range of 10{sup 9} to 10{sup 10} cm{sup −3} and a distance of ∼1 pc, and the gas with blueshift velocity of ∼1400 km s{sup −1} has a density of 10{sup 3} cm{sup −3} and a distance of ∼1 kpc.

  9. Novel Features for Brain-Computer Interfaces

    Science.gov (United States)

    Woon, W. L.; Cichocki, A.

    2007-01-01

    While conventional approaches of BCI feature extraction are based on the power spectrum, we have tried using nonlinear features for classifying BCI data. In this paper, we report our test results and findings, which indicate that the proposed method is a potentially useful addition to current feature extraction techniques. PMID:18364991

  10. In Silico Modeling of Gastrointestinal Drug Absorption: Predictive Performance of Three Physiologically Based Absorption Models.

    Science.gov (United States)

    Sjögren, Erik; Thörn, Helena; Tannergren, Christer

    2016-06-06

    particle size. In conclusion, it was shown that all three software packages are useful to guide formulation development. However, as a consequence of the high fraction of inaccurate predictions (prediction error >2-fold) and the clear trend toward decreased accuracy with decreased predicted fabs observed with Simcyp, the results indicate that GI-Sim and GastroPlus perform better than Simcyp in predicting the intestinal absorption of the incompletely absorbed drugs when a higher degree of accuracy is needed. In addition, this study suggests that modeling and simulation research groups should perform systematic model evaluations using their own input data to maximize confidence in model performance and output.

  11. Absorption and Metabolism of Xanthophylls

    Directory of Open Access Journals (Sweden)

    Eiichi Kotake-Nara

    2011-06-01

    Full Text Available Dietary carotenoids, especially xanthophylls, have attracted significant attention because of their characteristic biological activities, including anti-allergic, anti-cancer, and anti-obese actions. Although no less than forty carotenoids are ingested under usual dietary habits, only six carotenoids and their metabolites have been found in human tissues, suggesting selectivity in the intestinal absorption of carotenoids. Recently, facilitated diffusion in addition to simple diffusion has been reported to mediate the intestinal absorption of carotenoids in mammals. The selective absorption of carotenoids may be caused by uptake to the intestinal epithelia by the facilitated diffusion and an unknown excretion to intestinal lumen. It is well known that β-carotene can be metabolized to vitamin A after intestinal absorption of carotenoids, but little is known about the metabolic transformation of non provitamin A xanthophylls. The enzymatic oxidation of the secondary hydroxyl group leading to keto-carotenoids would occur as a common pathway of xanthophyll metabolism in mammals. This paper reviews the absorption and metabolism of xanthophylls by introducing recent advances in this field.

  12. Absorption and metabolism of xanthophylls.

    Science.gov (United States)

    Kotake-Nara, Eiichi; Nagao, Akihiko

    2011-01-01

    Dietary carotenoids, especially xanthophylls, have attracted significant attention because of their characteristic biological activities, including anti-allergic, anti-cancer, and anti-obese actions. Although no less than forty carotenoids are ingested under usual dietary habits, only six carotenoids and their metabolites have been found in human tissues, suggesting selectivity in the intestinal absorption of carotenoids. Recently, facilitated diffusion in addition to simple diffusion has been reported to mediate the intestinal absorption of carotenoids in mammals. The selective absorption of carotenoids may be caused by uptake to the intestinal epithelia by the facilitated diffusion and an unknown excretion to intestinal lumen. It is well known that β-carotene can be metabolized to vitamin A after intestinal absorption of carotenoids, but little is known about the metabolic transformation of non provitamin A xanthophylls. The enzymatic oxidation of the secondary hydroxyl group leading to keto-carotenoids would occur as a common pathway of xanthophyll metabolism in mammals. This paper reviews the absorption and metabolism of xanthophylls by introducing recent advances in this field.

  13. Modeling of optical absorption of silver prolate nanoparticles embedded in sol-gel glasses

    International Nuclear Information System (INIS)

    Renteria, V.M.; Garcia-Macedo, J.

    2005-01-01

    Silver prolate nanoparticles were obtained in silica gels prepared by the sol-gel process. Heating them at 900 deg. C for few minutes, the samples showed a yellow-orange color. A strong optical absorption with an asymmetric peak centred at 425 nm due to surface plasmon resonance of silver nanoparticles was observed. High-resolution transmission electron microscopy images showed silver prolate particles (average axial ratio AR = 0.76) randomly oriented with broad size distribution. The size changed from 9 to 3 nm and the prolate form changed to almost spherical (AR = 0.92) when the samples were heated longer time at 900 deg. C. In these samples, the absorption peak was shifted from 425 up to 460 nm. After heat treatment, the absorption spectrum did not change any more in some months, indicating that the particles obtained through this method are stable at room temperature. The Gans theory was used to fit the experimental spectra. The fit was not good until we assumed in the calculations all the physical features come from the system such as the volume fraction, shape and size of the metallic particles, and refractive index of the silica matrix. It was necessary to consider also a refractive index that come from oxidation on the surface of the metallic particles. With these considerations the fit with the Gans theory was good enough, and the difference between the calculated and experimental spectra was very small, factor 20 better than when oxidation is ignored. So then, the oxidation from the metallic particles must be taken in account to explain the experimental absorption spectra. These results are discussed

  14. Modeling of optical absorption of silver prolate nanoparticles embedded in sol-gel glasses

    Energy Technology Data Exchange (ETDEWEB)

    Renteria, V.M. [Departamento de Estado Solido, Instituto de Fisica, UNAM, P.O. Box 20-364, 01000 Mexico, Distrito Federal (Mexico); Garcia-Macedo, J. [Departamento de Estado Solido, Instituto de Fisica, UNAM, P.O. Box 20-364, 01000 Mexico, Distrito Federal (Mexico)]. E-mail: gamaj@fisica.unam.mx

    2005-05-15

    Silver prolate nanoparticles were obtained in silica gels prepared by the sol-gel process. Heating them at 900 deg. C for few minutes, the samples showed a yellow-orange color. A strong optical absorption with an asymmetric peak centred at 425 nm due to surface plasmon resonance of silver nanoparticles was observed. High-resolution transmission electron microscopy images showed silver prolate particles (average axial ratio AR = 0.76) randomly oriented with broad size distribution. The size changed from 9 to 3 nm and the prolate form changed to almost spherical (AR = 0.92) when the samples were heated longer time at 900 deg. C. In these samples, the absorption peak was shifted from 425 up to 460 nm. After heat treatment, the absorption spectrum did not change any more in some months, indicating that the particles obtained through this method are stable at room temperature. The Gans theory was used to fit the experimental spectra. The fit was not good until we assumed in the calculations all the physical features come from the system such as the volume fraction, shape and size of the metallic particles, and refractive index of the silica matrix. It was necessary to consider also a refractive index that come from oxidation on the surface of the metallic particles. With these considerations the fit with the Gans theory was good enough, and the difference between the calculated and experimental spectra was very small, factor 20 better than when oxidation is ignored. So then, the oxidation from the metallic particles must be taken in account to explain the experimental absorption spectra. These results are discussed.

  15. Absorptive coding metasurface for further radar cross section reduction

    Science.gov (United States)

    Sui, Sai; Ma, Hua; Wang, Jiafu; Pang, Yongqiang; Feng, Mingde; Xu, Zhuo; Qu, Shaobo

    2018-02-01

    Lossless coding metasurfaces and metamaterial absorbers have been widely used for radar cross section (RCS) reduction and stealth applications, which merely depend on redirecting electromagnetic wave energy into various oblique angles or absorbing electromagnetic energy, respectively. Here, an absorptive coding metasurface capable of both the flexible manipulation of backward scattering and further wideband bistatic RCS reduction is proposed. The original idea is carried out by utilizing absorptive elements, such as metamaterial absorbers, to establish a coding metasurface. We establish an analytical connection between an arbitrary absorptive coding metasurface arrangement of both the amplitude and phase and its far-field pattern. Then, as an example, an absorptive coding metasurface is demonstrated as a nonperiodic metamaterial absorber, which indicates an expected better performance of RCS reduction than the traditional lossless coding metasurface and periodic metamaterial-absorber. Both theoretical analysis and full-wave simulation results show good accordance with the experiment.

  16. Evaluation of wavelet spectral features in pathological detection and discrimination of yellow rust and powdery mildew in winter wheat with hyperspectral reflectance data

    Science.gov (United States)

    Shi, Yue; Huang, Wenjiang; Zhou, Xianfeng

    2017-04-01

    Hyperspectral absorption features are important indicators of characterizing plant biophysical variables for the automatic diagnosis of crop diseases. Continuous wavelet analysis has proven to be an advanced hyperspectral analysis technique for extracting absorption features; however, specific wavelet features (WFs) and their relationship with pathological characteristics induced by different infestations have rarely been summarized. The aim of this research is to determine the most sensitive WFs for identifying specific pathological lesions from yellow rust and powdery mildew in winter wheat, based on 314 hyperspectral samples measured in field experiments in China in 2002, 2003, 2005, and 2012. The resultant WFs could be used as proxies to capture the major spectral absorption features caused by infestation of yellow rust or powdery mildew. Multivariate regression analysis based on these WFs outperformed conventional spectral features in disease detection; meanwhile, a Fisher discrimination model exhibited considerable potential for generating separable clusters for each infestation. Optimal classification returned an overall accuracy of 91.9% with a Kappa of 0.89. This paper also emphasizes the WFs and their relationship with pathological characteristics in order to provide a foundation for the further application of this approach in monitoring winter wheat diseases at the regional scale.

  17. Absorption properties of identical atoms

    International Nuclear Information System (INIS)

    Sancho, Pedro

    2013-01-01

    Emission rates and other optical properties of multi-particle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas. -- Highlights: •The absorption rates of a pair of identical atoms in product and (anti)symmetrized states are different. •The modifications of the optical properties are essentially determined by the overlapping between the atoms. •The absorption properties differ, in some cases, for bosons and fermions

  18. Transdermic absorption of Melagenina II

    International Nuclear Information System (INIS)

    Hernandez Gonzalez, I.; Martinez Lopez, B.; Ruiz Pena, M.; Caso Pena, R.

    1997-01-01

    The transdermic absorption of Melagenina II (MII) was evaluated. MII was a labelled with 125I by the yodogen method and purified by column chromatography with Sephadex LH-20 in ethanol: water (7:3). In vitro absorption of ( 125I ) - MII thought human skin was carried out in Keshary-Chien modified diffusion cells. Tape stripping method was applied after 24 hours to evaluate the accumulated activity in dermis and epidermis. In vivo assays were performed in Sprague Dawley rats to analyze absorption of MII until 24 hours after a single application and for five days a low penetrability of the drug while in vivo there were not found blood levels significantly greater than zero , nevertheless and important amount of radioactivity was found in feces and urine. The activity was concentrated mainly in the application site in both models

  19. Architecture for Absorption Based Heaters

    Science.gov (United States)

    Moghaddam, Saeed; Chugh, Devesh

    2018-04-24

    An absorption based heater is constructed on a fluid barrier heat exchanging plate such that it requires little space in a structure. The absorption based heater has a desorber, heat exchanger, and absorber sequentially placed on the fluid barrier heat exchanging plate. The vapor exchange faces of the desorber and the absorber are covered by a vapor permeable membrane that is permeable to a refrigerant vapor but impermeable to an absorbent. A process fluid flows on the side of the fluid barrier heat exchanging plate opposite the vapor exchange face through the absorber and subsequently through the heat exchanger. The absorption based heater can include a second plate with a condenser situated parallel to the fluid barrier heat exchanging plate and opposing the desorber for condensation of the refrigerant for additional heating of the process fluid.

  20. Phytases for improved iron absorption

    DEFF Research Database (Denmark)

    Nielsen, Anne Veller Friis; Meyer, Anne S.

    2016-01-01

    Phytase enzymes present an alternative to iron supplements, because they have been shown to improve iron absorption by means of catalysing the degradation of a potent iron absorption inhibitor: phytic acid. Phytic acid is a hexaphosphate of inositol and is particularly prevalent in cereal grains......, where it serves as a storage molecule for phosphorous. Phytic acid is also associated with minerals. The minerals are bound by chelation to the negatively charged phosphate groups in phytic acid. Phytases catalyse the dephosphorylation of phytic acid, thus releasing bound minerals to make them available...... for absorption. This article presents research on phytase catalysis in gastric conditions and considers potential benefits and drawbacks for using phytases as a food supplement....

  1. Unsupervised Feature Subset Selection

    DEFF Research Database (Denmark)

    Søndberg-Madsen, Nicolaj; Thomsen, C.; Pena, Jose

    2003-01-01

    This paper studies filter and hybrid filter-wrapper feature subset selection for unsupervised learning (data clustering). We constrain the search for the best feature subset by scoring the dependence of every feature on the rest of the features, conjecturing that these scores discriminate some ir...... irrelevant features. We report experimental results on artificial and real data for unsupervised learning of naive Bayes models. Both the filter and hybrid approaches perform satisfactorily....

  2. Terahertz gas sensor based on absorption-induced transparency

    Directory of Open Access Journals (Sweden)

    Rodrigo Sergio G.

    2016-01-01

    Full Text Available A system for the detection of spectral signatures of gases at the Terahertz regime is presented. The system consists in an initially opaque holey metal film whereby the introduction of a gas provokes the appearance of spectral features in transmission and reflection, due to the phenomenom of absorption-induced transparency (AIT. The peaks in transmission and dips in reflection observed in AIT occur close to the absorption energies of the molecules, hence its name. The presence of the gas would be thus revealed as a strong drop in reflectivity measurements at one (or several of the gas absorption resonances. As a proof of principle, we theoretically demonstrate how the AIT-based sensor would serve to detect tiny amounts of hydrocyanic acid.

  3. Absorption-heat-pump system

    Science.gov (United States)

    Grossman, G.; Perez-Blanco, H.

    1983-06-16

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

  4. Absorption Efficiency of Receiving Antennas

    DEFF Research Database (Denmark)

    Andersen, Jørgen Bach; Frandsen, Aksel

    2005-01-01

    A receiving antenna with a matched load will always scatter some power. This paper sets an upper and a lower bound on the absorption efficiency (absorbed power over sum of absorbed and scattered powers), which lies between 0 and 100% depending on the directivities of the antenna and scatter...... patterns. It can approach 100% as closely as desired, although in practice this may not be an attractive solution. An example with a small endfire array of dipoles shows an efficiency of 93%. Several examples of small conical horn antennas are also given, and they all have absorption efficiencies less than...

  5. Lichens as pollution indicators

    Energy Technology Data Exchange (ETDEWEB)

    Rose, F

    1970-01-01

    Although lichens are generally considered to be of little use to man, their sensitivity to air pollution makes them good biological indicators. The author describes how this feature can help to establish relative degrees of air pollution. He notes areas where lichens are reduced in number and vigor, and some in which they have disappeared altogether. He challenges the idea that dryness is responsible, since they have also disappeared from damp woodland areas. Experimental work supports the view that sulfur dioxide is the major factor rather than smoke, although there is no definitive proof. Lichen damage correlates best with mean winter levels of air pollution by SO/sub 2/. 16 references, 1 figure.

  6. A triazole derivative as a new acid-base indicator

    Directory of Open Access Journals (Sweden)

    Volkan Numan Bulut

    2010-12-01

    Full Text Available In this study a new pH indicator, 3-benzyl-4-p-nitrobenzylidenamino-4,5-dihydro-1,2,4-triazole-5-on (BPNBAT, soluble in acetonitrile:water (1:4, was developed. The estimation of pH is possible either from the position of the absorption maxima or from the absorbance intensity at a constant wavelength. This feature allowed us to determine the basic transition range of the medium because BPNBAT is colorless at pH lower than 8.5 and showed strong yellow-green color with high extinction coefficient in the pH range of 8.5–10.1. pKa, pH at equivalent point and the molar absorptivity (in the aqueous medium at 380 nm of BPNBAT are determined as 9.3, 8.3 and 8.8 x 103 L.mol-1.cm-1, respectively. The color change at the transition range can be attributed to the resonance structures of BPNBAT. The triazole compound was compared with thymolphthalein for accuracy test.

  7. Konference Distillation and Absorption 2010

    Czech Academy of Sciences Publication Activity Database

    Bendová, Magdalena

    2009-01-01

    Roč. 103, č. 10 (2009), s. 862 ISSN 0009-2770 R&D Projects: GA MŠk LA320 Institutional research plan: CEZ:AV0Z40720504 Keywords : conference * announcement * distillation and absorption Subject RIV: CF - Physical ; Theoretical Chemistry

  8. Gamm-ray absorption techniques

    International Nuclear Information System (INIS)

    Charlton, J.S.

    1986-01-01

    In this chapter the principles of gamma-ray absorption are described and important applications in plant and process techniques such as measurement of thickness of deposits on pipes, checking for voids in concrete, metal corrosion, measurement of the density of materials inside vessels in industrial radiography are discussed. (U.K.)

  9. Emission and absorption of radiation

    International Nuclear Information System (INIS)

    Fetter, S.

    1992-01-01

    A full understanding of fissile-material detection requires a solid knowledge of nuclear physics, especially the emission and absorption of radiation. The purpose of this paper is therefore to give a brief explanation of these processes so that the reader can better understand the assumptions leading to the results in the main text

  10. Absorptive capacity and smart companies

    Directory of Open Access Journals (Sweden)

    Patricia Moro González

    2014-12-01

    Full Text Available Purpose: The current competitive environment is substantially modifying the organizations’ learning processes due to a global increase of available information allowing this to be transformed into knowledge. This opportunity has been exploited since the nineties by the tools of “Business Analytics” and “Business Intelligence” but, nevertheless, being integrated in the study of new organizational capacities engaged in the process of creating intelligence inside organizations is still an outstanding task. The review of the concept of absorptive capacity and a detailed study from the perspective of this new reality will be the main objective of study of this paper.Design/methodology/approach: By comparing classical absorptive capacity and absorptive capacity from the point of view of information management tools in each one of the three stages of the organizational learning cycle, some gaps of the former are overcome/fulfilled. The academic/bibliographical references provided in this paper have been obtained from ISI web of knowledge, Scopus and Dialnet data bases, supporting the state of affairs on absorptive capacity and thereafter filtering by "Business Intelligence" and "Business Analytics". Specialized websites and Business Schools` Publications there have also been included, crowning the content on information management tools used that are currently used in the strategic consulting.Findings: Our contribution to the literature is the development of "smart absorptive capacity". This is a new capacity emerging from the reformulation of the classical concept of absorptive capacity wherein some aspects of its definition that might have been omitted are emphasized. The result of this new approach is the creation of a new Theoretical Model of Organizational Intelligence, which aims to explain, within the framework of the Resources and Capabilities Theory, the competitive advantage achieved by the so-called smart companies

  11. Credibility judgments of narratives: language, plausibility, and absorption.

    Science.gov (United States)

    Nahari, Galit; Glicksohn, Joseph; Nachson, Israel

    2010-01-01

    Two experiments were conducted in order to find out whether textual features of narratives differentially affect credibility judgments made by judges having different levels of absorption (a disposition associated with rich visual imagination). Participants in both experiments were exposed to a textual narrative and requested to judge whether the narrator actually experienced the event he described in his story. In Experiment 1, the narrative varied in terms of language (literal, figurative) and plausibility (ordinary, anomalous). In Experiment 2, the narrative varied in terms of language only. The participants' perceptions of the plausibility of the story described and the extent to which they were absorbed in reading were measured. The data from both experiments together suggest that the groups applied entirely different criteria in credibility judgments. For high-absorption individuals, their credibility judgment depends on the degree to which the text can be assimilated into their own vivid imagination, whereas for low-absorption individuals it depends mainly on plausibility. That is, high-absorption individuals applied an experiential mental set while judging the credibility of the narrator, whereas low-absorption individuals applied an instrumental mental set. Possible cognitive mechanisms and implications for credibility judgments are discussed.

  12. Absorption Mode FT-ICR Mass Spectrometry Imaging

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-03

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

  13. Emission from water vapor and absorption from other gases at 5-7.5 μm in Spitzer-IRS Spectra Of Protoplanetary Disks

    Energy Technology Data Exchange (ETDEWEB)

    Sargent, B. A. [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Forrest, W.; Watson, Dan M.; Kim, K. H.; Richter, I.; Tayrien, C. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); D' Alessio, P.; Calvet, N. [Department of Astronomy, The University of Michigan, 500 Church Street, 830 Dennison Building, Ann Arbor, MI 48109 (United States); Furlan, E. [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Green, J. [Department of Astronomy, University of Texas, 1 University Station, Austin, TX 78712 (United States); Pontoppidan, K., E-mail: baspci@rit.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

    2014-09-10

    We present spectra of 13 T Tauri stars in the Taurus-Auriga star-forming region showing emission in Spitzer Space Telescope Infrared Spectrograph 5-7.5 μm spectra from water vapor and absorption from other gases in these stars' protoplanetary disks. Seven stars' spectra show an emission feature at 6.6 μm due to the ν{sub 2} = 1-0 bending mode of water vapor, with the shape of the spectrum suggesting water vapor temperatures >500 K, though some of these spectra also show indications of an absorption band, likely from another molecule. This water vapor emission contrasts with the absorption from warm water vapor seen in the spectrum of the FU Orionis star V1057 Cyg. The other 6 of the 13 stars have spectra showing a strong absorption band, peaking in strength at 5.6-5.7 μm, which for some is consistent with gaseous formaldehyde (H{sub 2}CO) and for others is consistent with gaseous formic acid (HCOOH). There are indications that some of these six stars may also have weak water vapor emission. Modeling of these stars' spectra suggests these gases are present in the inner few AU of their host disks, consistent with recent studies of infrared spectra showing gas in protoplanetary disks.

  14. Feature Selection by Reordering

    Czech Academy of Sciences Publication Activity Database

    Jiřina, Marcel; Jiřina jr., M.

    2005-01-01

    Roč. 2, č. 1 (2005), s. 155-161 ISSN 1738-6438 Institutional research plan: CEZ:AV0Z10300504 Keywords : feature selection * data reduction * ordering of features Subject RIV: BA - General Mathematics

  15. Converting Sabine absorption coefficients to random incidence absorption coefficients

    DEFF Research Database (Denmark)

    Jeong, Cheol-Ho

    2013-01-01

    are suggested: An optimization method for the surface impedances for locally reacting absorbers, the flow resistivity for extendedly reacting absorbers, and the flow resistance for fabrics. With four porous type absorbers, the conversion methods are validated. For absorbers backed by a rigid wall, the surface...... coefficients to random incidence absorption coefficients are proposed. The overestimations of the Sabine absorption coefficient are investigated theoretically based on Miki's model for porous absorbers backed by a rigid wall or an air cavity, resulting in conversion factors. Additionally, three optimizations...... impedance optimization produces the best results, while the flow resistivity optimization also yields reasonable results. The flow resistivity and flow resistance optimization for extendedly reacting absorbers are also found to be successful. However, the theoretical conversion factors based on Miki's model...

  16. Search features of digital libraries

    Directory of Open Access Journals (Sweden)

    Alastair G. Smith

    2000-01-01

    Full Text Available Traditional on-line search services such as Dialog, DataStar and Lexis provide a wide range of search features (boolean and proximity operators, truncation, etc. This paper discusses the use of these features for effective searching, and argues that these features are required, regardless of advances in search engine technology. The literature on on-line searching is reviewed, identifying features that searchers find desirable for effective searching. A selective survey of current digital libraries available on the Web was undertaken, identifying which search features are present. The survey indicates that current digital libraries do not implement a wide range of search features. For instance: under half of the examples included controlled vocabulary, under half had proximity searching, only one enabled browsing of term indexes, and none of the digital libraries enable searchers to refine an initial search. Suggestions are made for enhancing the search effectiveness of digital libraries, for instance by: providing a full range of search operators, enabling browsing of search terms, enhancement of records with controlled vocabulary, enabling the refining of initial searches, etc.

  17. Calcium absorption from fortified ice cream formulations compared with calcium absorption from milk.

    Science.gov (United States)

    van der Hee, Regine M; Miret, Silvia; Slettenaar, Marieke; Duchateau, Guus S M J E; Rietveld, Anton G; Wilkinson, Joy E; Quail, Patricia J; Berry, Mark J; Dainty, Jack R; Teucher, Birgit; Fairweather-Tait, Susan J

    2009-05-01

    Optimal bone mass in early adulthood is achieved through appropriate diet and lifestyle, thereby protecting against osteoporosis and risk of bone fracture in later life. Calcium and vitamin D are essential to build adequate bones, but calcium intakes of many population groups do not meet dietary reference values. In addition, changes in dietary patterns are exacerbating the problem, thereby emphasizing the important role of calcium-rich food products. We have designed a calcium-fortified ice cream formulation that is lower in fat than regular ice cream and could provide a useful source of additional dietary calcium. Calcium absorption from two different ice cream formulations was determined in young adults and compared with milk. Sixteen healthy volunteers (25 to 45 years of age), recruited from the general public of The Netherlands, participated in a randomized, reference-controlled, double-blind cross-over study in which two test products and milk were consumed with a light standard breakfast on three separate occasions: a standard portion of ice cream (60 g) fortified with milk minerals and containing a low level (3%) of butter fat, ice cream (60 g) fortified with milk minerals and containing a typical level (9%) of coconut oil, and reduced-fat milk (1.7% milk fat) (200 mL). Calcium absorption was measured by the dual-label stable isotope technique. Effects on calcium absorption were evaluated by analysis of variance. Fractional absorption of calcium from the 3% butterfat ice cream, 9% coconut oil ice cream, and milk was 26%+/-8%, 28%+/-5%, and 31%+/-9%, respectively, and did not differ significantly (P=0.159). Results indicate that calcium bioavailability in the two calcium-fortified ice cream formulations used in this study is as high as milk, indicating that ice cream may be a good vehicle for delivery of calcium.

  18. Near-infrared free carrier absorption in heavily doped silicon

    International Nuclear Information System (INIS)

    Baker-Finch, Simeon C.; McIntosh, Keith R.; Yan, Di; Fong, Kean Chern; Kho, Teng C.

    2014-01-01

    Free carrier absorption in heavily doped silicon can have a significant impact on devices operating in the infrared. In the near infrared, the free carrier absorption process can compete with band to band absorption processes, thereby reducing the number of available photons to optoelectronic devices such as solar cells. In this work, we fabricate 18 heavily doped regions by phosphorus and boron diffusion into planar polished silicon wafers; the simple sample structure facilitates accurate and precise measurement of the free carrier absorptance. We measure and model reflectance and transmittance dispersion to arrive at a parameterisation for the free carrier absorption coefficient that applies in the wavelength range between 1000 and 1500 nm, and the range of dopant densities between ∼10 18 and 3 × 10 20  cm −3 . Our measurements indicate that previously published parameterisations underestimate the free carrier absorptance in phosphorus diffusions. On the other hand, published parameterisations are generally consistent with our measurements and model for boron diffusions. Our new model is the first to be assigned uncertainty and is well-suited to routine device analysis

  19. Screening for Plant Features

    NARCIS (Netherlands)

    Heijden, van der G.W.A.M.; Polder, G.

    2015-01-01

    In this chapter, an overview of different plant features is given, from (sub)cellular to canopy level. A myriad of methods is available to measure these features using image analysis, and often, multiple methods can be used to measure the same feature. Several criteria are listed for choosing a

  20. Sulfur K-edge X-ray absorption spectroscopy as an experimental probe for S-nitroso proteins

    International Nuclear Information System (INIS)

    Szilagyi, Robert K.; Schwab, David E.

    2005-01-01

    X-ray absorption spectroscopy at the sulfur K-edge (2.4-2.6 keV) provides a sensitive and specific technique to identify S-nitroso compounds, which have significance in nitric oxide-based cell signaling. Unique spectral features clearly distinguish the S-nitroso-form of a cysteine residue from the sulfhydryl-form or from a methionine thioether. Comparison of the sulfur K-edge spectra of thiolate, thiol, thioether, and S-nitroso thiolate compounds indicates high sensitivity of energy positions and intensities of XAS pre-edge features as determined by the electronic environment of the sulfur absorber. A new experimental setup is being developed for reaching the in vivo concentration range of S-nitroso thiol levels in biological samples

  1. Assessing the Ability of Vegetation Indices to Identify Shallow Subsurface Water Flow Pathways from Hyperspectral Imagery Using Machine Learning: Methodology

    Science.gov (United States)

    Byers, J. M.; Doctor, K.

    2017-12-01

    A common application of the satellite and airborne acquired hyperspectral imagery in the visible and NIR spectrum is the assessment of vegetation. Various absorption features of plants related to both water and chlorophyll content can be used to measure the vigor and access to underlying water sources of the vegetation. The typical strategy is to form hand-crafted features from the hyperspectral data cube by selecting two wavelengths to form difference or ratio images in the pixel space. The new image attempts to provide greater contrast for some feature of the vegetation. The Normalized Difference Vegetation Index (NDVI) is a widely used example formed from the ratio of differences and sums at two different wavelengths. There are dozens of these indices that are ostensibly formed using insights about the underlying physics of the spectral absorption with claims to efficacy in representing various properties of vegetation. In the language of machine learning these vegetation indices are features that can be used as a useful data representation within an algorithm. In this work we use a powerful approach from machine learning, probabilistic graphical models (PGM), to balance the competing needs of using existing hydrological classifications of terrain while finding statistically reliable features within hyperspectral data for identifying the generative process of the data. The algorithm in its simplest form is called a Naïve Bayes (NB) classifier and can be constructed in a data-driven estimation procedure of the conditional probability distributions that form the PGM. The Naïve Bayes model assumes that all vegetation indices (VI) are independent of one another given the hydrological class label. We seek to test its validity in a pilot study of detecting subsurface water flow pathways from VI. A more sophisticated PGM will also be explored called a tree-augmented NB that accounts for the probabilistic dependence between VI features. This methodology provides a

  2. Remodularizing Java programs for comprehension of features

    DEFF Research Database (Denmark)

    Olszak, Andrzej; Jørgensen, Bo Nørregaard

    2009-01-01

    . In absence of these mechanisms, feature implementations tend to be scattered and tangled in terms of object-oriented abstractions, making the code implementing features difficult to locate and comprehend. In this paper we present a semi-automatic method for feature-oriented remodularization of Java programs....... Our method uses execution traces to locate implementations of features, and Java packages to establish explicit feature modules. To evaluate usefulness of the approach, we present a case study where we apply our method to two real-world software systems. The obtained results indicate a significant...

  3. Absorption and Transport of Sea Cucumber Saponins from Apostichopus japonicus

    Directory of Open Access Journals (Sweden)

    Shuai Li

    2016-06-01

    Full Text Available The present study is focused on the intestinal absorption of sea cucumber saponins. We determined the pharmacokinetic characteristics and bioavailability of Echinoside A and Holotoxin A1; the findings indicated that the bioavailability of Holotoxin A1 was lower than Echinoside A. We inferred that the differences in chemical structure between compounds was a factor that explained their different characteristics of transport across the intestine. In order to confirm the absorption characteristics of Echinoside A and Holotoxin A1, we examined their transport across Caco-2 cell monolayer and effective permeability by single-pass intestinal perfusion. The results of Caco-2 cell model indicate that Echinoside A is transported by passive diffusion, and not influenced by the exocytosis of P-glycoprotein (P-gp, expressed in the apical side of Caco-2 monolayers as the classic inhibitor. The intestinal perfusion also demonstrated well the absorption of Echinoside A and poor absorption of Holotoxin A1, which matched up with the result of the Caco-2 cell model. The results demonstrated our conjecture and provides fundamental information on the relationship between the chemical structure of these sea cucumber saponins and their absorption characteristics, and we believe that our findings build a foundation for the further metabolism study of sea cucumber saponins and contribute to the further clinical research of saponins.

  4. Absorption and Transport of Sea Cucumber Saponins from Apostichopus japonicus.

    Science.gov (United States)

    Li, Shuai; Wang, Yuanhong; Jiang, Tingfu; Wang, Han; Yang, Shuang; Lv, Zhihua

    2016-06-17

    The present study is focused on the intestinal absorption of sea cucumber saponins. We determined the pharmacokinetic characteristics and bioavailability of Echinoside A and Holotoxin A₁; the findings indicated that the bioavailability of Holotoxin A₁ was lower than Echinoside A. We inferred that the differences in chemical structure between compounds was a factor that explained their different characteristics of transport across the intestine. In order to confirm the absorption characteristics of Echinoside A and Holotoxin A₁, we examined their transport across Caco-2 cell monolayer and effective permeability by single-pass intestinal perfusion. The results of Caco-2 cell model indicate that Echinoside A is transported by passive diffusion, and not influenced by the exocytosis of P-glycoprotein (P-gp, expressed in the apical side of Caco-2 monolayers as the classic inhibitor). The intestinal perfusion also demonstrated well the absorption of Echinoside A and poor absorption of Holotoxin A₁, which matched up with the result of the Caco-2 cell model. The results demonstrated our conjecture and provides fundamental information on the relationship between the chemical structure of these sea cucumber saponins and their absorption characteristics, and we believe that our findings build a foundation for the further metabolism study of sea cucumber saponins and contribute to the further clinical research of saponins.

  5. Absorption/desorption in sprays

    International Nuclear Information System (INIS)

    Naimpally, A.

    1987-01-01

    This survey paper shall seek to present the present state of knowledge concerning absorption and desorption in spray chambers. The first part of the paper presents the theories and formulas for the atomization and break-up of sprays in nozzles. Formulas for the average (sauter-mean) diameters are then presented. For the case of absorption processes, the formulas for the dimensionless mass transfer coefficients is in drops. The total; mass transfer is the total of the transfer in individual drops. For the case of desorption of sparingly soluble gases from liquids in a spray chamber, the mass transfer occurs in the spray just at the point of break-up of the jet. Formulas for the desorption of gases are presented

  6. Bent Electro-Absorption Modulator

    DEFF Research Database (Denmark)

    2002-01-01

    by applying a variable electric or electronmagnetic field. The modulation of the complex refractive index results in a modulation of the refractive index contrast and the absorption coefficient for the waveguide at the frequency of the light. By carefully adjusting the composition of the semiconducting...... components and the applied electric field in relation to the frequency of the modulated radiation, the bending losses (and possibly coupling losses) will provide extinction of light guided by the bent waveguide section. The refractive index contract may be modulated while keeping the absorption coefficient......The present invention relates to a method and a device for modulating optical signals based on modulating bending losses in bend, quantum well semiconductor waveguide sections. The complex refractive index of the optical active semiconducting components of the waveguide section is modulated...

  7. Geometrical interpretation of optical absorption

    Energy Technology Data Exchange (ETDEWEB)

    Monzon, J. J.; Barriuso, A. G.; Sanchez-Soto, L. L. [Departamento de Optica, Facultad de Fisica, Universidad Complutense, E-28040 Madrid (Spain); Montesinos-Amilibia, J. M. [Departamento de Geometria y Topologia, Facultad de Matematicas, Universidad Complutense, E-28040 Madrid (Spain)

    2011-08-15

    We reinterpret the transfer matrix for an absorbing system in very simple geometrical terms. In appropriate variables, the system appears as performing a Lorentz transformation in a (1 + 3)-dimensional space. Using homogeneous coordinates, we map that action on the unit sphere, which is at the realm of the Klein model of hyperbolic geometry. The effects of absorption appear then as a loxodromic transformation, that is, a rhumb line crossing all the meridians at the same angle.

  8. Modernization of Atomic Absorption Spectrophotometer

    International Nuclear Information System (INIS)

    Tasic, Visa; Milivojevic, Dragan; Karabasevic, Dejan

    2003-01-01

    In Copper Institute in Bor, connection has been made between absorption spectrophotometer and standard PC with the aim to make its operation more reliable and comfortable. Applied solution includes both software and hardware components. An I/O interface module has been installed in PC [1]. Software component consists of programs for measuring and interpretation of results. Paper presents details of this job realization.(Author)

  9. Turbulent effective absorptivity and refractivity

    International Nuclear Information System (INIS)

    Rax, J.M.

    1984-09-01

    The problem of wave propagation in a turbulent magnetized plasma is investigated. Considering small scale, low frequency density fluctuations we solve the Maxwell equations and show that the eikonal approximation remains valid with an effective refractivity and an effective absorptivity taking into account the energy diffusion due to the turbulent motion. Then the result is applied to the problem of lower hybrid waves scattering by drift waves density fluctuations in tokamaks

  10. Slowing down with resonance absorption

    International Nuclear Information System (INIS)

    Moura Neto, C. de; Nair, R.P.K.

    1979-08-01

    The presence of heavy nuclei in nuclear reactors, in significant concentrations, facilitates the appearance of absorption resonances. For the moderation in the presence of absorbers an exact solution of the integral equations is possible by numerical methods. Approximated solutions for separated resonances in function of the practical width, (NR and NRIM approximations) are discussed in this paper. The method is generalized, presenting the solution by an intermediate approximation, in the definition of the resonance integral. (Author) [pt

  11. Absorption and Metabolism of Xanthophylls

    OpenAIRE

    Kotake-Nara, Eiichi; Nagao, Akihiko

    2011-01-01

    Dietary carotenoids, especially xanthophylls, have attracted significant attention because of their characteristic biological activities, including anti-allergic, anti-cancer, and anti-obese actions. Although no less than forty carotenoids are ingested under usual dietary habits, only six carotenoids and their metabolites have been found in human tissues, suggesting selectivity in the intestinal absorption of carotenoids. Recently, facilitated diffusion in addition to simple diffusion has bee...

  12. Non-resonant microwave absorption studies of superconducting ...

    Indian Academy of Sciences (India)

    Abstract. Non-resonant microwave absorption (NRMA) studies of superconducting MgB2 and a sample containing 10% by weight of MgO in MgB2 are reported. The NRMA results indicate near absence of intergranular weak links in the pure MgB2 sample. A linear temperature dependence of the lower critical field Hc1 is ...

  13. Organizational forms and knowledge absorption

    Directory of Open Access Journals (Sweden)

    Radovanović Nikola

    2016-01-01

    Full Text Available Managing the entire portion of knowledge in an organization is a challenging task. At the organizational level, there can be enormous quantities of unknown, poorly valued or inefficiently applied knowledge. This is normally followed with the underdeveloped potential or inability of organizations to absorb knowledge from external sources. Facilitation of the efficient internal flow of knowledge within the established communication network may positively affect organizational capacity to absorb or identify, share and subsequently apply knowledge to commercial ends. Based on the evidences that the adoption of different organizational forms affects knowledge flows within an organization, this research analyzed the relationship between common organizational forms and absorptive capacity of organizations. In this paper, we test the hypothesis stating that the organizational structure affects knowledge absorption and exploitation in the organization. The methodology included quantitative and qualitative research method based on a questionnaire, while the data has been statistically analyzed and the hypothesis has been tested with the use of cross-tabulation and chi-square tests. The findings suggest that the type of organizational form affects knowledge absorption capacity and that having a less formalized and more flexible structure in an organization increases absorbing and exploiting opportunities of potentially valuable knowledge.

  14. Observational Evidence Linking Interstellar UV Absorption to PAH Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Blasberger, Avi; Behar, Ehud; Perets, Hagai B. [Department of Physics, Technion (Israel); Brosch, Noah [The Wise Observatory and School of Physics and Astronomy, Tel Aviv University (Israel); Tielens, Alexander G. G. M. [Leiden Observatory, Leiden University (Netherlands)

    2017-02-20

    The 2175 Å UV extinction feature was discovered in the mid-1960s, yet its physical origin remains poorly understood. One suggestion is absorption by polycyclic aromatic hydrocarbon (PAH) molecules, which is supported by theoretical molecular structure computations and by laboratory experiments. PAHs are positively detected by their 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μ m IR emission bands, which are specified by their modes of vibration. A definitive empirical link between the 2175 Å UV extinction and the IR PAH emission bands, however, is still missing. We present a new sample of hot stars that have both 2175 Å absorption and IR PAH emission. We find significant shifts of the central wavelength of the UV absorption feature, up to 2350 Å, but predominantly in stars that also have IR PAH emission. These UV shifts depend on stellar temperature in a fashion that is similar to the shifts of the 6.2 and 7.7 μ m IR PAH bands, that is, the features are increasingly more redshifted as the stellar temperature decreases, but only below ∼15 kK. Above 15 kK both UV and IR features retain their nominal values. Moreover, we find a suggestive correlation between the UV and IR shifts. We hypothesize that these similar dependences of both the UV and IR features on stellar temperature hint at a common origin of the two in PAH molecules and may establish the missing link between the UV and IR observations. We further suggest that the shifts depend on molecular size, and that the critical temperature of ∼15 kK above which no shifts are observed is related to the onset of UV-driven hot-star winds and their associated shocks.

  15. Observational Evidence Linking Interstellar UV Absorption to PAH Molecules

    International Nuclear Information System (INIS)

    Blasberger, Avi; Behar, Ehud; Perets, Hagai B.; Brosch, Noah; Tielens, Alexander G. G. M.

    2017-01-01

    The 2175 Å UV extinction feature was discovered in the mid-1960s, yet its physical origin remains poorly understood. One suggestion is absorption by polycyclic aromatic hydrocarbon (PAH) molecules, which is supported by theoretical molecular structure computations and by laboratory experiments. PAHs are positively detected by their 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μ m IR emission bands, which are specified by their modes of vibration. A definitive empirical link between the 2175 Å UV extinction and the IR PAH emission bands, however, is still missing. We present a new sample of hot stars that have both 2175 Å absorption and IR PAH emission. We find significant shifts of the central wavelength of the UV absorption feature, up to 2350 Å, but predominantly in stars that also have IR PAH emission. These UV shifts depend on stellar temperature in a fashion that is similar to the shifts of the 6.2 and 7.7 μ m IR PAH bands, that is, the features are increasingly more redshifted as the stellar temperature decreases, but only below ∼15 kK. Above 15 kK both UV and IR features retain their nominal values. Moreover, we find a suggestive correlation between the UV and IR shifts. We hypothesize that these similar dependences of both the UV and IR features on stellar temperature hint at a common origin of the two in PAH molecules and may establish the missing link between the UV and IR observations. We further suggest that the shifts depend on molecular size, and that the critical temperature of ∼15 kK above which no shifts are observed is related to the onset of UV-driven hot-star winds and their associated shocks.

  16. Enriching Absorptive Capacity through Social Interaction

    NARCIS (Netherlands)

    Hotho, Jasper J.; Becker-Ritterspach, Florian; Saka-Helmhout, Ayse

    Absorptive capacity is frequently highlighted as a key determinant of knowledge transfer within multinational enterprises. But how individual behaviour translates into absorptive capacity at the subsidiary level, and how this is contingent on subsidiaries' social context, remains under-addressed.

  17. Hopping absorption edge in silicon inversion layers

    International Nuclear Information System (INIS)

    Kostadinov, I.Z.

    1983-09-01

    The low frequency gap observed in the absorption spectrum of silicon inversion layers is related to the AC variable range hopping. The frequency dependence of the absorption coefficient is calculated. (author)

  18. Evolution of absorption machines; Evolution des machines a absorption

    Energy Technology Data Exchange (ETDEWEB)

    Soide, I; Klemsdal, E [Gaz de France (GDF), 75 - Paris (France); Le Goff, P; Hornut, J M [LSGC-ENSIC, 54 - Nancy (France)

    1998-12-31

    Most of todays absorption air-conditioning machineries use the lithium bromide-water pair. The most performing can operate at a 150-160 deg. C, the temperature being limited by the corrosion resistance of metals with respect to LiBr solutions. Also, there is a revival of interest for water-ammonia systems. These systems require the use of a rectification column which reduces the coefficient of performance. Higher thermal performances are reached with hydrocarbon pairs and ternary mixtures (water-methanol-LiBr etc..). This paper presents different schemes of refrigerating heat pumps based on these different systems. (J.S.)

  19. Evolution of absorption machines; Evolution des machines a absorption

    Energy Technology Data Exchange (ETDEWEB)

    Soide, I.; Klemsdal, E. [Gaz de France (GDF), 75 - Paris (France); Le Goff, P.; Hornut, J.M. [LSGC-ENSIC, 54 - Nancy (France)

    1997-12-31

    Most of todays absorption air-conditioning machineries use the lithium bromide-water pair. The most performing can operate at a 150-160 deg. C, the temperature being limited by the corrosion resistance of metals with respect to LiBr solutions. Also, there is a revival of interest for water-ammonia systems. These systems require the use of a rectification column which reduces the coefficient of performance. Higher thermal performances are reached with hydrocarbon pairs and ternary mixtures (water-methanol-LiBr etc..). This paper presents different schemes of refrigerating heat pumps based on these different systems. (J.S.)

  20. Characteristics of water absorption of beans

    OpenAIRE

    上中, 登紀子; 森, 孝夫; 豊沢, 功; Tokiko, Uenaka; Takao, Mori; Isao, Toyosawa

    2001-01-01

    Characteristics of water absorption of soybean, azuki bean and kidney beans (cv. Toramame and Taishokintoki) were investigated. The way of water absorption of soybean was different from that of other beans, because soybeans absorbed water from whole surface of seed coat immediately after the immersion. Azuki beans absorbed extremely slowly water from only strophiole, and then the water absorption in other tissue was induced by a certain amount of water absorption playing a role of trigger. Th...

  1. Strong water absorption in the dayside emission spectrum of the planet HD 189733b.

    Science.gov (United States)

    Grillmair, Carl J; Burrows, Adam; Charbonneau, David; Armus, Lee; Stauffer, John; Meadows, Victoria; van Cleve, Jeffrey; von Braun, Kaspar; Levine, Deborah

    2008-12-11

    Recent observations of the extrasolar planet HD 189733b did not reveal the presence of water in the emission spectrum of the planet. Yet models of such 'hot-Jupiter' planets predict an abundance of atmospheric water vapour. Validating and constraining these models is crucial to understanding the physics and chemistry of planetary atmospheres in extreme environments. Indications of the presence of water in the atmosphere of HD 189733b have recently been found in transmission spectra, where the planet's atmosphere selectively absorbs the light of the parent star, and in broadband photometry. Here we report the detection of strong water absorption in a high-signal-to-noise, mid-infrared emission spectrum of the planet itself. We find both a strong downturn in the flux ratio below 10 microm and discrete spectral features that are characteristic of strong absorption by water vapour. The differences between these and previous observations are significant and admit the possibility that predicted planetary-scale dynamical weather structures may alter the emission spectrum over time. Models that match the observed spectrum and the broadband photometry suggest that heat redistribution from the dayside to the nightside is weak. Reconciling this with the high nightside temperature will require a better understanding of atmospheric circulation or possible additional energy sources.

  2. Special dynamic behavior of an aluminum alloy and effects on energy absorption in train collisions

    Directory of Open Access Journals (Sweden)

    Chao Yang

    2016-05-01

    Full Text Available Dynamic tension tests and compression tests were carried out for 5083-H111 aluminum alloy to investigate the dynamic mechanical behavior and its effect on energy absorption characteristics of an energy-absorbing device. The material constitutive relations were obtained at various levels of strain rates by means of tests. Three material models were performed on the energy-absorbing device of railway vehicles. We investigated the influence of the material dynamic behavior on the energy absorption capability. The results indicate that 5083-H111 aluminum alloy is endowed with negative strain rate sensitivity at medium–low strain rates and possesses the feature of negative and then positive strain rate sensitivity in the range of medium strain rates. The material presents obvious strain rate strengthening effect at high strain rates. Moreover, the order of magnitudes of the strain rate in the train collision is 0–2. It belongs to the medium strain rate. The practical absorbed energy of the structure made of 5083-H111 alloy is less than that of the same structure without regard to the strain rate effect in design phases.

  3. Damped Lyman-alpha absorption by disk galaxies with large redshifts. III. Intermediate-resolution spectroscopy

    International Nuclear Information System (INIS)

    Turnshek, D.A.; Wolfe, A.M.; Lanzetta, K.M.; Briggs, F.H.; Cohen, R.D.

    1989-01-01

    New intermediate-resolution spectroscopy for six members of a sample of 68 moderate- to high-redshift QSOs is presented. Evidence is reported which indicates that seven strong absorption features in the QSO spectra are due to damped Ly-alpha absorption. A standard curve-of-growth analysis on five of the damped systems is performed, and relevant properties are tabulated and discussed. Six of the seven damped Ly-alpha systems have H I column densities of 2 x 10 to the 20th/sq cm or larger, while the remaining system has an H I column density of about 10 to the 20th/sq cm. It is suggested that damped Ly-alpha systems arise when a sight line intercepts a high-redshift protogalaxy disk containing a quiescent cloud component characterized by high column density and low effective velocity dispersion. At the same time, the sight line usually intercepts a broader turbulent component, which is identified as the halo, characterized by much lower column density and higher effective velocity dispersion. 42 refs

  4. Uniform semiclassical approximation for absorptive scattering systems

    International Nuclear Information System (INIS)

    Hussein, M.S.; Pato, M.P.

    1987-07-01

    The uniform semiclassical approximation of the elastic scattering amplitude is generalized to absorptive systems. An integral equation is derived which connects the absorption modified amplitude to the absorption free one. Division of the amplitude into a diffractive and refractive components is then made possible. (Author) [pt

  5. Gas phase UV and IR absorption spectra of CxF2x+1CHO (x=1-4)

    DEFF Research Database (Denmark)

    Hashikawa, Y; Kawasaki, M; Waterland, RL

    2004-01-01

    The UV and IR spectra of CxF2x+1 CHO (x = 1-4) were investigated using computational and experimental techniques. CxF2x+1CHO (x = 1-4) have broad UV absorption features centered at 300-310 nm. The maximum absorption cross-section increases significantly and shifts slightly to the red with increased...

  6. Mining Videos for Features that Drive Attention

    Science.gov (United States)

    2015-04-01

    that can be added or removed from the final saliency computation. Examples of these features include intensity contrast, motion energy , color opponent...corresponding to the image. Each pixel in the feature map indicates the energy that the feature in question contributes at that location. In the standard...eye and head animation using a neurobio - logical model of visual attention. In: Bosacchi B, Fogel DB, Bezdek JC (eds) Proceedings of SPIE 48th annual

  7. Anomalies in resonant absorption line profiles of atoms with large hyperfine splitting

    International Nuclear Information System (INIS)

    Parkhomenko, A.I.; Pod'yachev, S.P.; Privalov, T.I.; Shalagin, A.M.

    1997-01-01

    We examine a monochromatic absorption line in the velocity-nonselective excitation of atoms when the components of the hyperfine stricture of the electronic ground states are optically pumped. We show that the absorption lines possess unusual substructures for some values of the hyperfine splitting of the ground state (which exceed the Doppler absorption linewidth severalfold). These substructures in the absorption spectrum are most apparent if the hyperfine structure of the excited electronic state is taken into account. We calculate the absorption spectra of monochromatic light near the D 1 and D 2 lines of atomic rubidium 85,87 Rb. With real hyperfine splitting taken into account, the D 1 and D 2 lines are modeled by 4- and 6-level diagrams, respectively. Finally, we show that atomic rubidium vapor can be successfully used to observe the spectral features experimentally

  8. Absorption spectrum of a V-type three-level atom driven by a coherent field

    International Nuclear Information System (INIS)

    Dong Po; Tang, S.H.

    2002-01-01

    We examine the absorption of a weak probe beam by a laser driven V-type atom with a pair of closely lying excited levels, where both the driving and probe lasers interact simultaneously with the two transitions. The effects of quantum interference among decay channels on the absorption spectra are also investigated. We introduce dipole moments in the dressed-state representation and the Hamiltonian in terms of the dressed states describing the interaction between the probe and the atom. In the degenerate case, features similar to that of a driven two-level atomic system are found due to some dark transitions in the spontaneous emission and the fact that the probe beam only detects certain transitions. In the nondegenerate case, the absorption spectrum is strongly influenced by the degree of quantum interference, resulting in different line shapes for emission peaks, absorption peaks, and dispersionlike profiles. The effect of probe polarization on the absorption spectrum is also investigated

  9. Self-absorption corrections for gamma ray spectral measurements of 210Pb in environmental samples

    International Nuclear Information System (INIS)

    Miller, K.M.

    1987-01-01

    Theoretical considerations and experimental data are used to demonstrate the basic behaviour of the self-absorption effect of a sample matrix in gamma ray spectrometry, particularly as it relates to the analysis of 210 Pb in environmental media. The results indicate that it may not be appropriate to apply the commonly used self-absorption function in all cases. (orig.)

  10. Simultaneous Atomic Absorption Spectrometry for Cadmium and Lead Determination in Wastewater: A Laboratory Exercise

    Science.gov (United States)

    Correia, Paulo R. M.; Oliveira, Pedro V.

    2004-01-01

    The simultaneous determination of cadmium and lead by multi-element atomic absorption spectrometry with electrochemical atomization is proposed by employing a problem-based approach. The reports indicate that the students assimilated the principles of the simultaneous atomic absorption spectrometry (SIMAAS), the role of the chemical modifier, the…

  11. Electron cyclotron absorption in Tokamak plasmas in the presence of radial transport of particles

    International Nuclear Information System (INIS)

    Rosa, Paulo R. da S.; Ziebell, Luiz F.

    1998-01-01

    We use quasilinear theory to study effects of particle radial transport on the electron cyclotron absorption coefficient by a current carrying plasma, in a tokamak modelated as a plasma slab. Our numerical results indicate significant modification in the profile of the electron cyclotron absorption coefficient when transport is taken into account relative to the situation without transport. (author)

  12. [The percutaneous absorption of diclofenac].

    Science.gov (United States)

    Riess, W; Schmid, K; Botta, L; Kobayashi, K; Moppert, J; Schneider, W; Sioufi, A; Strusberg, A; Tomasi, M

    1986-07-01

    The percutaneous absorption of diclofenac diethylammonium 1.16% (w/w) in a combination of emulsion cream and gel (Voltaren Emulgel) and of diclofenac sodium 1% (w/w) in a cream formulation (Voltaren cream) was investigated in guinea-pig, rabbit and man. The percutaneous absorption of diclofenac sodium in guinea-pig was 3 to 6% of the dose when the cream formulation in doses of 320, 100 or 40 mg was applied on 10 cm2 of occluded skin and left in place for 6 h. The transdermal delivery of 14C-labelled diclofenac yielded plateau plasma concentrations of radiotracer from 1.5 h after application until removal of the residual cream. Subsequently the steady state drug depots in the skin and muscle tissue were depleted promptly. During daily administration the steady state levels in the muscle tissue in proximity to the application site were about 3 times higher than in distant muscle tissue. By topical application on knee joints of rabbits diclofenac penetrated into the patellar ligament, the adipose corpus and the synovial fluid. In man the percutaneous absorption was 6% of the dose when the Emulgel formulation was spread by 5 mg/cm2 and left for 12 h on non-occluded skin. The pattern of metabolites of diclofenac in human urine was the same after topical and oral administration. In man, upon daily topical administration of 3 times 2.5 g cream formulation (10 mg/cm2) the diclofenac steady state plasma levels were 20 to 40 nmol/l.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Leaf absorption of 32P in the pumpkin

    International Nuclear Information System (INIS)

    Chamel, Andre; Roux-Aubert, M.T.

    1964-04-01

    The author presents a method to study the influence of various factors of the absorption of 32 P applied under the form of phosphates by a plant cultivated in conditions ensuring a normal development. Experiments provided indications on leaf absorption and 32 P transport by pumpkin leaves: phosphor 32 is absorbed and then quickly transported into the different organs of the plant (24 hours after treatment, it is present in aerial and underground parts), the quantity of absorbed phosphor increases with phosphor concentration in the applied solution, atmosphere humidity is an important factor for phosphor penetration into the leaves, plants absorb phosphor in darkness as well as in light, and the absorption of phosphor is not modified when applied with low glucose concentrations [fr

  14. Absorption and metabolic fate of bioactive dietary benzoxazinoids in humans

    DEFF Research Database (Denmark)

    Adhikari, Khem B; Laursen, Bente B; Gregersen, Per L

    2013-01-01

    benzoxazinoids with abundant HBOA-Glc (219 nmol × μmol−1 of creatinine). The sulfate and glucuronide conjugates of 2-hydroxy-1,4-benzoxazin-3-one (HBOA) and 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) were detected in plasma and urine, indicating substantial phase II metabolism. Direct absorption of lactam......Scope Benzoxazinoids, which are natural compounds recently identified in mature whole grain cereals and bakery products, have been suggested to have a range of pharmacological properties and health-protecting effects. There are no published reports concerned with the absorption and metabolism...... of bioactive benzoxazinoids in humans. Methods and results The absorption, metabolism, and excretion of ten different dietary benzoxazinoids were examined by LC-MS/MS by analyzing plasma and urine from 20 healthy human volunteers after daily intake of 143 μmol of total benzoxazinoids from rye bread and rye...

  15. Photoinduced absorption of Ag nanoparticles deposited on ITO substrate

    International Nuclear Information System (INIS)

    Ozga, K.; Oyama, M.; Szota, M.; Nabialek, M.; Kityk, I.V.; Slezak, A.; Umar, A.A.; Nouneh, K.

    2011-01-01

    Research highlights: → We study photoinduced absorption for two Ag NP deposited on the ITO. → The higher resistance eof the NP favors larger photoinduced changes. → Principal role is played by nanointerfaces. - Abstract: Substantial changes of absorption after illumination by 300 mW continuous wave green laser at 532 nm were observed. The effect of indium tin oxide (ITO) substrate was explored versus Ag nanoparticles (AgNPs) size, their regularity and surface plasmon resonance. The ITO substrate features play a crucial role for the formation of homogenous AgNPs. The attachments of AgNPs on ITO surface as well as their homogeneity are significantly changed under the influence of the laser treatment. We study the Ag NP deposited on the two different substrates which play a crucial role in the photoinduced absorption. The dependence of the photoinduced absorption versus the time of optical treatment is explained within a framework of the photopolarization of the particular trapping levels on the borders between the ITO substrate and the Ag NP.

  16. Photoinduced absorption of Ag nanoparticles deposited on ITO substrate

    Energy Technology Data Exchange (ETDEWEB)

    Ozga, K., E-mail: cate.ozga@wp.pl [Chair of Public Health, Czestochowa University of Technology, Al. Armii Krajowej 36B, 42-200 Czestochowa (Poland); Oyama, M. [Department of Material Chemisrty, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8520 (Japan); Szota, M. [Institute of Materials Science and Engineering, Technical University of Czestochowa, al. Armii Krajowej 19, 42-200 Czestochowa (Poland); Nabialek, M. [Institute of Physics, Czestochowa University of Technology, Al. Armii Krajowej 19, 42-200 Czestochowa (Poland); Kityk, I.V. [Electrical Engineering Department, Czestochowa University of Technology, Al. Armii Krajowej 17/19, 42-200 Czestochowa (Poland); Slezak, A. [Chair of Public Health, Czestochowa University of Technology, Al. Armii Krajowej 36B, 42-200 Czestochowa (Poland); Umar, A.A. [Institute of Micronegineering and Nanoelectronics Universiti Kebangsaan Malaysia 43600 UKM bangi, Selangor D.E. (Malaysia); Nouneh, K. [INANOTECH, Institute of Nanomaterials and Nanotechnology, MAScIR (Moroccan Advanced Science, Innovation and Research Foundation), ENSET, Av. Armee Royale, 10100, Rabat (Morocco)

    2011-06-15

    Research highlights: > We study photoinduced absorption for two Ag NP deposited on the ITO. > The higher resistance eof the NP favors larger photoinduced changes. > Principal role is played by nanointerfaces. - Abstract: Substantial changes of absorption after illumination by 300 mW continuous wave green laser at 532 nm were observed. The effect of indium tin oxide (ITO) substrate was explored versus Ag nanoparticles (AgNPs) size, their regularity and surface plasmon resonance. The ITO substrate features play a crucial role for the formation of homogenous AgNPs. The attachments of AgNPs on ITO surface as well as their homogeneity are significantly changed under the influence of the laser treatment. We study the Ag NP deposited on the two different substrates which play a crucial role in the photoinduced absorption. The dependence of the photoinduced absorption versus the time of optical treatment is explained within a framework of the photopolarization of the particular trapping levels on the borders between the ITO substrate and the Ag NP.

  17. A novel multiplex absorption spectrometer for time-resolved studies

    Science.gov (United States)

    Lewis, Thomas; Heard, Dwayne E.; Blitz, Mark A.

    2018-02-01

    A Time-Resolved Ultraviolet/Visible (UV/Vis) Absorption Spectrometer (TRUVAS) has been developed that can simultaneously monitor absorption at all wavelengths between 200 and 800 nm with millisecond time resolution. A pulsed photolysis laser (KrF 248 nm) is used to initiate chemical reactions that create the target species. The absorption signals from these species evolve as the composition of the gas in the photolysis region changes over time. The instrument can operate at pressures over the range ˜10-800 Torr and can measure time-resolved absorbances systems (in particular the Herriott cell), there are fundamental differences, most notably the ability to adjust each mirror to maximise the overlap between the probe beam and the photolysis laser. Another feature which aids the sensitivity and versatility of the system is the use of 2 high-throughput spectrographs coupled with sensitive line-array CCDs, which can measure absorbance from ˜200 to 800 nm simultaneously. The capability of the instrument is demonstrated via measurements of the absorption spectrum of the peroxy radical, HOCH2CH2O2, and its self-reaction kinetics.

  18. Physiologically Based Pharmacokinetic and Absorption Modeling for Osmotic Pump Products.

    Science.gov (United States)

    Ni, Zhanglin; Talattof, Arjang; Fan, Jianghong; Tsakalozou, Eleftheria; Sharan, Satish; Sun, Dajun; Wen, Hong; Zhao, Liang; Zhang, Xinyuan

    2017-07-01

    Physiologically based pharmacokinetic (PBPK) and absorption modeling approaches were employed for oral extended-release (ER) drug products based on an osmotic drug delivery system (osmotic pumps). The purpose was to systemically evaluate the in vivo relevance of in vitro dissolution for this type of formulation. As expected, in vitro dissolution appeared to be generally predictive of in vivo PK profiles, because of the unique feature of this delivery system that the in vitro and in vivo release of osmotic pump drug products is less susceptible to surrounding environment in the gastrointestinal (GI) tract such as pH, hydrodynamic, and food effects. The present study considered BCS (Biopharmaceutics Classification System) class 1, 2, and 3 drug products with half-lives ranging from 2 to greater than 24 h. In some cases, the colonic absorption models needed to be adjusted to account for absorption in the colon. C max (maximum plasma concentration) and AUCt (area under the concentration curve) of the studied drug products were sensitive to changes in colon permeability and segmental GI transit times in a drug product-dependent manner. While improvement of the methodology is still warranted for more precise prediction (e.g., colonic absorption and dynamic movement in the GI tract), the results from the present study further emphasized the advantage of using PBPK modeling in addressing product-specific questions arising from regulatory review and drug development.

  19. Dielectric Characteristics and Microwave Absorption of Graphene Composite Materials

    Directory of Open Access Journals (Sweden)

    Kevin Rubrice

    2016-10-01

    Full Text Available Nowadays, many types of materials are elaborated for microwave absorption applications. Carbon-based nanoparticles belong to these types of materials. Among these, graphene presents some distinctive features for electromagnetic radiation absorption and thus microwave isolation applications. In this paper, the dielectric characteristics and microwave absorption properties of epoxy resin loaded with graphene particles are presented from 2 GHz to 18 GHz. The influence of various parameters such as particle size (3 µm, 6–8 µm, and 15 µm and weight ratio (from 5% to 25% are presented, studied, and discussed. The sample loaded with the smallest graphene size (3 µm and the highest weight ratio (25% exhibits high loss tangent (tanδ = 0.36 and a middle dielectric constant ε′ = 12–14 in the 8–10 GHz frequency range. As expected, this sample also provides the highest absorption level: from 5 dB/cm at 4 GHz to 16 dB/cm at 18 GHz.

  20. Carbon Dioxide Absorption Heat Pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    2002-01-01

    A carbon dioxide absorption heat pump cycle is disclosed using a high pressure stage and a super-critical cooling stage to provide a non-toxic system. Using carbon dioxide gas as the working fluid in the system, the present invention desorbs the CO2 from an absorbent and cools the gas in the super-critical state to deliver heat thereby. The cooled CO2 gas is then expanded thereby providing cooling and is returned to an absorber for further cycling. Strategic use of heat exchangers can increase the efficiency and performance of the system.

  1. Phytases for Improved Iron Absorption

    DEFF Research Database (Denmark)

    Nielsen, Anne Veller Friis; Nyffenegger, Christian; Meyer, Anne S.

    2014-01-01

    Microbial phytases (EC 3.1.3.8) catalyse dephosphorylation of phytic acid, which is the primary storage compound for phosphorous in cereal kernels. The negatively charged phosphates in phytic acid chelate iron (Fe3+) and thus retards iron bioavailability in humans 1. Supplementation of microbial...... phytase can improve iron absorption from cereal-based diets 2. In order for phytase to catalyse iron release in vivo the phytase must be robust to low pH and proteolysis in the gastric ventricle. Our work has compared the robustness of five different microbial phytases, evaluating thermal stability...

  2. Iodine Absorption Cells Purity Testing

    Czech Academy of Sciences Publication Activity Database

    Hrabina, Jan; Zucco, M.; Philippe, Ch.; Pham, Minh Tuan; Holá, Miroslava; Acef, O.; Lazar, Josef; Číp, Ondřej

    2017-01-01

    Roč. 17, č. 1 (2017), s. 1-13, č. článku 17010102. ISSN 1424-8220 R&D Projects: GA ČR GA15-18430S; GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : iodine cells * absorption spectroscopy * laser spectroscopy * laser standards * frequency stability Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 2.677, year: 2016

  3. Microwave Absorption Characteristics of Tire

    Science.gov (United States)

    Zhang, Yuzhe; Hwang, Jiann-Yang; Peng, Zhiwei; Andriese, Matthew; Li, Bowen; Huang, Xiaodi; Wang, Xinli

    The recycling of waste tires has been a big environmental problem. About 280 million waste tires are produced annually in the United States and more than 2 billion tires are stockpiled, which cause fire hazards and health issues. Tire rubbers are insoluble elastic high polymer materials. They are not biodegradable and may take hundreds of years to decompose in the natural environment. Microwave irradiation can be a thermal processing method for the decomposition of tire rubbers. In this study, the microwave absorption properties of waste tire at various temperatures are characterized to determine the conditions favorable for the microwave heating of waste tires.

  4. Photo absorption studies of polyatomic molecules using Indus 1 synchrotron radiation source

    International Nuclear Information System (INIS)

    Saraswathy, P.; Sunanda, K.; Aparna, S.; Rajashekar, B.N.; Das, N.C.

    2004-06-01

    The Photophysics beamline is a medium resolution beamline designed for carrying out photo absorption and fluorescence experiments using the synchrotron radiation source Indus-l. This beamline has been commissioned recently and is in operation. An experimental setup for gas phase absorption studies has been developed and installed. Absorption spectra of a few polyatomicmolecules viz. benzene, ammonia, carbon disulphide and acetone were recorded in the wavelength region 1500 -3000 A. The results from this study indicated the satisfactory performance of the beam line as well as the experimental setup. Details of the first set of absorption experiments carried out are discussed in this report. (author)

  5. Microwave measurements of the absolute values of absorption by water vapour in the atmosphere.

    Science.gov (United States)

    Hogg, D C; Guiraud, F O

    1979-05-31

    MEASUREMENT of the absolute value of absorption by water vapour at microwave frequencies is difficult because the effect is so small. Far in the wings of the absorption lines, in the so-called 'windows' of the spectrum, it is especially difficult to achieve high accuracy in the free atmosphere. But it is in these windows that the behaviour of the absorption is important from both applied and scientific points of view. Satellite communications, remote sensing of the atmosphere, and radioastronomy, are all influenced by this behaviour. Measurements on an Earth-space path are reported here; the results indicate a nonlinear relationship between absorption and water-vapour content.

  6. Characterization of selective binding of alkali cations with carboxylate by x-ray absorption spectroscopy of liquid microjets

    Energy Technology Data Exchange (ETDEWEB)

    Saykally, Richard J; Uejio, Janel S.; Schwartz, Craig P.; Duffin, Andrew M.; Drisdell, Walter S.; Cohen, Ronald C.; Saykally, Richard J.

    2008-01-08

    We describe an approach for characterizing selective binding between oppositely charged ionic functional groups under biologically relevant conditions. Relative shifts in K-shell x-ray absorption spectra of aqueous cations and carboxylate anions indicate the corresponding binding strengths via perturbations of carbonyl antibonding orbitals. XAS spectra measured for aqueous formate and acetate solutions containing lithium, sodium, and potassium cations reveal monotonically stronger binding of the lighter metals, supporting recent results from simulations and other experiments. The carbon K-edge spectra of the acetate carbonyl feature centered near 290 eV clearly indicate a preferential interaction of sodium versus potassium, which was less apparent with formate. These results are in accord with the Law of Matching Water Affinities, relating relative hydration strengths of ions to their respective tendencies to form contact ion pairs. Density functional theory calculations of K-shell spectra support the experimental findings.

  7. Characterization of selective binding of alkali cations with carboxylate by x-ray absorption spectroscopy of liquid microjets

    International Nuclear Information System (INIS)

    Saykally, Richard J; Uejio, Janel S.; Schwartz, Craig P.; Duffin, Andrew M.; Drisdell, Walter S.; Cohen, Ronald C.; Saykally, Richard J.

    2008-01-01

    We describe an approach for characterizing selective binding between oppositely charged ionic functional groups under biologically relevant conditions. Relative shifts in K-shell x-ray absorption spectra of aqueous cations and carboxylate anions indicate the corresponding binding strengths via perturbations of carbonyl antibonding orbitals. XAS spectra measured for aqueous formate and acetate solutions containing lithium, sodium, and potassium cations reveal monotonically stronger binding of the lighter metals, supporting recent results from simulations and other experiments. The carbon K-edge spectra of the acetate carbonyl feature centered near 290 eV clearly indicate a preferential interaction of sodium versus potassium, which was less apparent with formate. These results are in accord with the Law of Matching Water Affinities, relating relative hydration strengths of ions to their respective tendencies to form contact ion pairs. Density functional theory calculations of K-shell spectra support the experimental findings

  8. Absorption of DTPA from the respiratory tracts of Beagle dogs

    International Nuclear Information System (INIS)

    Dudley, R.E.; Muggenburg, B.A.; Cuddihy, R.G.

    1978-01-01

    Absorption of diethylenetriaminepentaacetic acid (DTPA) from the nasopharyngeal (NP), tracheobronchial (TB) and pulmonary (P) regions of Beagle dogs was determined because of the current interest in aerosolized DTPA as a method for removal of internally deposited radionuclides. Radiolabeled DTPA was instilled into the NP, TB and P regions of Beagle dogs and its subsequent translocation was followed for 48 hours. Results revealed that 16, 48 and 90% of the instilled DTPA was absorbed into the circulatory system from the NP, TB and P regions, respectively. A comparison was also made between NP absorption of aerosolized DTPA and DTPA instilled into the nasopharynx. Nasopharyngeal absorption of aerosolized DTPA, 23%, was slightly higher than that of instilled DTPA. Diethylenetriaminepentaacetic acid deposited in the respiratory tract remained in the body longer than intravenously injected DTPA. These findings indicate that substantial absorption of DTPA occurs from all regions of the respiratory tract and that DTPA need not be deposited deep within the respiratory tract to produce systemic absorption of DTPA for the removal of internally deposited radioactive isotopes

  9. Facilities Performance Indicators Report, 2008-09

    Science.gov (United States)

    Hills, Christina, Ed.

    2010-01-01

    This paper features another expanded Web-based Facilities Performance Indicators Report (FPI). The purpose of APPA's Facilities Performance Indicators is to provide a representative set of statistics about facilities in educational institutions. The 2008-09 iteration of the Web-based Facilities Performance Indicators Survey was posted and…

  10. Decision trees to characterise the roles of permeability and solubility on the prediction of oral absorption.

    Science.gov (United States)

    Newby, Danielle; Freitas, Alex A; Ghafourian, Taravat

    2015-01-27

    Oral absorption of compounds depends on many physiological, physiochemical and formulation factors. Two important properties that govern oral absorption are in vitro permeability and solubility, which are commonly used as indicators of human intestinal absorption. Despite this, the nature and exact characteristics of the relationship between these parameters are not well understood. In this study a large dataset of human intestinal absorption was collated along with in vitro permeability, aqueous solubility, melting point, and maximum dose for the same compounds. The dataset allowed a permeability threshold to be established objectively to predict high or low intestinal absorption. Using this permeability threshold, classification decision trees incorporating a solubility-related parameter such as experimental or predicted solubility, or the melting point based absorption potential (MPbAP), along with structural molecular descriptors were developed and validated to predict oral absorption class. The decision trees were able to determine the individual roles of permeability and solubility in oral absorption process. Poorly permeable compounds with high solubility show low intestinal absorption, whereas poorly water soluble compounds with high or low permeability may have high intestinal absorption provided that they have certain molecular characteristics such as a small polar surface or specific topology. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  11. Disorder-induced enhancement of indirect absorption in a GeSn photodetector grown by molecular beam epitaxy

    International Nuclear Information System (INIS)

    Li, H.; Chang, C.; Cheng, H. H.; Sun, G.; Soref, R. A.

    2016-01-01

    We report an investigation on the absorption mechanism of a GeSn photodetector with 2.4% Sn composition in the active region. Responsivity is measured and absorption coefficient is calculated. Square root of absorption coefficient linearly depends on photon energy indicating an indirect transition. However, the absorption coefficient is found to be at least one order of magnitude higher than that of most other indirect materials, suggesting that the indirect optical absorption transition cannot be assisted only by phonon. Our analysis of absorption measurements by other groups on the same material system showed the values of absorption coefficient on the same order of magnitude. Our study reveals that the strong enhancement of absorption for the indirect optical transition is the result of alloy disorder from the incorporation of the much larger Sn atoms into the Ge lattice that are randomly distributed.

  12. The influence of local electric fields on photoinduced absorption in dye-sensitized solar cells.

    Science.gov (United States)

    Cappel, Ute B; Feldt, Sandra M; Schöneboom, Jan; Hagfeldt, Anders; Boschloo, Gerrit

    2010-07-07

    The dye-sensitized solar cell (DSC) challenges conventional photovoltaics with its potential for low-cost production and its flexibility in terms of color and design. Transient absorption spectroscopy is widely used to unravel the working mechanism of DSCs. A surprising, unexplained feature observed in these studies is an apparent bleach of the ground-state absorption of the dye, under conditions where the dye is in the ground state. Here, we demonstrate that this feature can be attributed to a change of the local electric field affecting the absorption spectrum of the dye, an effect related to the Stark effect first reported in 1913. We present a method for measuring the effect of an externally applied electric field on the absorption of dye monolayers adsorbed on flat TiO(2) substrates. The measured signal has the shape of the first derivative of the absorption spectra of the dyes and reverses sign along with the reversion of the direction of the change in dipole moment upon excitation relative to the TiO(2) surface. A very similar signal is observed in photoinduced absorption spectra of dye-sensitized TiO(2) electrodes under solar cell conditions, demonstrating that the electric field across the dye molecules changes upon illumination. This result has important implications for the analysis of transient absorption spectra of DSCs and other molecular optoelectronic devices and challenges the interpretation of many previously published results.

  13. Hydrological and Biogeochemical Controls on Absorption and Fluorescence of Dissolved Organic Matter in the Northern South China Sea

    Science.gov (United States)

    Wang, Chao; Guo, Weidong; Li, Yan; Stubbins, Aron; Li, Yizhen; Song, Guodong; Wang, Lei; Cheng, Yuanyue

    2017-12-01

    The Kuroshio intrusion from the West Philippine Sea (WPS) and mesoscale eddies are important hydrological features in the northern South China Sea (SCS). In this study, absorption and fluorescence of dissolved organic matter (CDOM and FDOM) were determined to assess the impact of these hydrological features on DOM dynamics in the SCS. DOM in the upper 100 m of the northern SCS had higher absorption, fluorescence, and degree of humification than in the Kuroshio Current of the WPS. The results of an isopycnal mixing model showed that CDOM and humic-like FDOM inventories in the upper 100 m of the SCS were modulated by the Kuroshio intrusion. However, protein-like FDOM was influenced by in situ processes. This basic trend was modified by mesoscale eddies, three of which were encountered during the fieldwork (one warm eddy and two cold eddies). DOM optical properties inside the warm eddy resembled those of DOM in the WPS, indicating that warm eddies could derive from the Kuroshio Current through Luzon Strait. DOM at the center of cold eddies was enriched in humic-like fluorescence and had lower spectral slopes than in eddy-free waters, suggesting inputs of humic-rich DOM from upwelling and enhanced productivity inside the eddy. Excess CDOM and FDOM in northern SCS intermediate water led to export to the Pacific Ocean interior, potentially delivering refractory carbon to the deep ocean. This study demonstrated that DOM optical properties are promising tools to study active marginal sea-open ocean interactions.

  14. JCE Feature Columns

    Science.gov (United States)

    Holmes, Jon L.

    1999-05-01

    The Features area of JCE Online is now readily accessible through a single click from our home page. In the Features area each column is linked to its own home page. These column home pages also have links to them from the online Journal Table of Contents pages or from any article published as part of that feature column. Using these links you can easily find abstracts of additional articles that are related by topic. Of course, JCE Online+ subscribers are then just one click away from the entire article. Finding related articles is easy because each feature column "site" contains links to the online abstracts of all the articles that have appeared in the column. In addition, you can find the mission statement for the column and the email link to the column editor that I mentioned above. At the discretion of its editor, a feature column site may contain additional resources. As an example, the Chemical Information Instructor column edited by Arleen Somerville will have a periodically updated bibliography of resources for teaching and using chemical information. Due to the increase in the number of these resources available on the WWW, it only makes sense to publish this information online so that you can get to these resources with a simple click of the mouse. We expect that there will soon be additional information and resources at several other feature column sites. Following in the footsteps of the Chemical Information Instructor, up-to-date bibliographies and links to related online resources can be made available. We hope to extend the online component of our feature columns with moderated online discussion forums. If you have a suggestion for an online resource you would like to see included, let the feature editor or JCE Online (jceonline@chem.wisc.edu) know about it. JCE Internet Features JCE Internet also has several feature columns: Chemical Education Resource Shelf, Conceptual Questions and Challenge Problems, Equipment Buyers Guide, Hal's Picks, Mathcad

  15. Iodine Absorption Cells Purity Testing

    Directory of Open Access Journals (Sweden)

    Jan Hrabina

    2017-01-01

    Full Text Available This article deals with the evaluation of the chemical purity of iodine-filled absorption cells and the optical frequency references used for the frequency locking of laser standards. We summarize the recent trends and progress in absorption cell technology and we focus on methods for iodine cell purity testing. We compare two independent experimental systems based on the laser-induced fluorescence method, showing an improvement of measurement uncertainty by introducing a compensation system reducing unwanted influences. We show the advantages of this technique, which is relatively simple and does not require extensive hardware equipment. As an alternative to the traditionally used methods we propose an approach of hyperfine transitions’ spectral linewidth measurement. The key characteristic of this method is demonstrated on a set of testing iodine cells. The relationship between laser-induced fluorescence and transition linewidth methods will be presented as well as a summary of the advantages and disadvantages of the proposed technique (in comparison with traditional measurement approaches.

  16. New features in MEDM

    International Nuclear Information System (INIS)

    Evans, K. Jr.

    1999-01-01

    MEDM, which is derived from Motif Editor and Display Manager, is the primary graphical interface to the EPICS control system. This paper describes new features that have been added to MEDM in the last two years. These features include new editing capabilities, a PV Info dialog box, a means of specifying limits and precision, a new implementation of the Cartesian Plot, new features for several objects, new capability for the Related Display, help, a user-configurable Execute Menu, reconfigured start-up options, and availability for Windows 95/98/NT. Over one hundred bugs have been fixed, and the program is quite stable and in extensive use

  17. [Spectral absorption properties of the water constituents in the estuary of Zhujiang River].

    Science.gov (United States)

    Wang, Shan-shan; Wang, Yong-bo; Fu, Qing-hua; Yin, Bin; Li, Yun-mei

    2014-12-01

    Spectral absorption properties of the water constituents is the main factor affecting the light field under the surface of the water and the spectrum above the surface of the water. Thus, the study is useful for understanding of the water spectral property and the remote reversing of water quality parameters. Absorption properties of total suspended particles, non-algal particles, phytoplankton and CDOM were analyzed using the 30 samples collected in July 2013 in the estuary of Zhujiang River. The results indicated that: (1) the non-algal particles absorption dominated the absorption of the total suspended particles; (2) the absorption coefficient of the non-algal particles, which mainly came from the terrigenous deposits, decreased exponentially from short to long wavelength. In addition, the average value and spatial variation of the slope S(d) were higher than those in inland case- II waters; (3) the absorption coefficient of phytoplankton in 440 nm showed a better polynomial relationship with chlorophyll a concentration, while the absorption coefficient of phytoplankton in 675 nm linearly related with the chlorophyll a concentration. Moreover, the influence of accessory pigments on phytoplankton absorption coefficient mainly existed in the range of short wavelength, and Chlorophyll a was the main influencing factor for phytoplankton absorption in long wavelength. The specific absorption coefficient of phytoplankton decreased the power exponentially with the increase of the chlorophyll a concentration; (4) CDOM mainly came from the terrigenous sources and its spectral curve had an absorption shoulder between 250-290 nm. Thus, a piecewise S(g) fitting function could effectively express CDOM absorption properties, i.e., M value and S(g) value in period A (240-260 nm) showed a strong positive correlation. The M value was low, and the humic acid had a high proportion in CDOM; (5) the non-algal particles absorption dominated the total absorption in the estuary of

  18. $J/\\psi$ Absorption in Heavy Ion Collisions

    CERN Document Server

    Maiani, Luciano; Polosa, Antonio; Riquer, V

    2004-01-01

    We present a new calculation of the pi-J/psi dissociation cross sections within the Constituent Quark-Meson Model recently introduced. To discuss the absorption of J/psi in heavy-ion collisions, we assume the J/psi to be produced inside a thermalized pion gas, as discussed by Bjorken, and introduce the corrections due to absorption by nuclear matter as well. We fit the absorption length of the J/psi to the data obtained at the CERN SPS by the NA50 Collaboration for Pb-Pb collisions. Collisions of lower centrality allow us to determine the temperature and the energy density of the pion gas. For both these quantities we find values close to those indicated by lattice gauge calculations for the transition to a quark-gluon plasma. A simple extrapolation to more central collisions, which takes into account the increase of the energy deposited due to the increased nucleon flux, fails to reproduce the break in J/psi absorption indicated by NA50, thus lending support to the idea that an unconfined quark-gluon phase m...

  19. Laboratory simulation of infrared astrophysical features

    International Nuclear Information System (INIS)

    Rose, L.A.

    1979-01-01

    Laboratory infrared emission and absorption spectra have been taken of terrestrial silicates, meteorites and lunar soils in the form of micrometer and sub-micrometer grains. The emission spectra were taken in a way that imitates telescopic observations. The purpose was to see which materials best simulate the 10 μm astrophysical feature. The emission spectra of dunite, fayalite and Allende give a good fit to the 10 μm broadband emission feature of comets Bennett and Kohoutek. A study of the effect of grain size on the presence of the 10 μm emission features of dunite shows that for particles larger than 37 μm no feature is seen. The emission spectrum of the Murray meteorite, a Type 2 carbonaceous chondrite, is quite similar to the intermediate resolution spectrum of comet Kohoutek in the 10 μm region. Hydrous silicates or amorphous magnesium silicates in combination with high-temperature condensates, such as olivine or anorthite, would yield spectra that match the intermediate resolution spectrum of comet Kohoutek in the 10 μm region. Glassy olivine and glassy anorthite in approximately equal proportions would also give a spectrum that is a good fit to the cometary 10 μm feature. (Auth.)

  20. Abdominal cocoon: sonographic features.

    Science.gov (United States)

    Vijayaraghavan, S Boopathy; Palanivelu, Chinnusamy; Sendhilkumar, Karuppusamy; Parthasarathi, Ramakrishnan

    2003-07-01

    An abdominal cocoon is a rare condition in which the small bowel is encased in a membrane. The diagnosis is usually established at surgery. Here we describe the sonographic features of this condition.

  1. Mesoblastic nephroma: Pathological features

    African Journals Online (AJOL)

    N.M. El-Badawy

    determined mainly by its histologic type, we found it worthwhile to elaborate more on the gross and microscopic features of ... behavior of mesoblastic nephroma is determined mainly by its his- .... However, it exhibits a nodular growth pattern at.

  2. Feature Binding in Zebrafish

    Directory of Open Access Journals (Sweden)

    P Neri

    2012-07-01

    Full Text Available Binding operations are primarily ascribed to cortex or similarly complex avian structures. My experiments show that the zebrafish, a lower vertebrate lacking cortex, supports visual feature binding of form and motion for the purpose of social behavior. These results challenge the notion that feature binding may require highly evolved neural structures and demonstrate that the nervous system of lower vertebrates can afford unexpectedly complex computations.

  3. Phosphorus absorption in drip irrigation

    International Nuclear Information System (INIS)

    Guennelon, R.; Habib, R.

    1979-01-01

    Introducing the use of solute phosphate with drip irrigation may be an unsatisfying practice on account of the very weak mobility of PO 4 anion. Nevertheless P can move down to 30-40 cm depth by following the saturated flux along earth-worms holes or crakes, or by displacement in very narrow structural porosity, even in heavy soils. In this case roots cannot easily absorb PO 4 from soil solution, as soon as the soil is quite saturated. On the other hand, it seems that P absorption occurs very quickly and easily when the implantation of 32 P tagged solution is carried out at the border of zone which is concerned by the irrigation effects [fr

  4. HI Absorption in Merger Remnants

    Science.gov (United States)

    Teng, Stacy H.; Veileux, Sylvain; Baker, Andrew J.

    2012-01-01

    It has been proposed that ultraluminous infrared galaxies (ULIRGs) pass through a luminous starburst phase, followed by a dust-enshrouded AGN phase, and finally evolve into optically bright "naked" quasars once they shed their gas/dust reservoirs through powerful wind events. We present the results of our recent 21- cm HI survey of 21 merger remnants with the Green Bank Telescope. These remnants were selected from the QUEST (Quasar/ULIRG Evolution Study) sample of ULIRGs and PG quasars; our targets are all bolometrically dominated by AGN and sample all phases of the proposed ULIRG -> IR-excess quasar -> optical quasar sequence. We explore whether there is an evolutionary connection between ULIRGs and quasars by looking for the occurrence of HI absorption tracing neutral gas outflows; our results will allow us to identify where along the sequence the majority of a merger's gas reservoir is expelled.

  5. Multistage quantum absorption heat pumps.

    Science.gov (United States)

    Correa, Luis A

    2014-04-01

    It is well known that heat pumps, while being all limited by the same basic thermodynamic laws, may find realization on systems as "small" and "quantum" as a three-level maser. In order to quantitatively assess how the performance of these devices scales with their size, we design generalized N-dimensional ideal heat pumps by merging N-2 elementary three-level stages. We set them to operate in the absorption chiller mode between given hot and cold baths and study their maximum achievable cooling power and the corresponding efficiency as a function of N. While the efficiency at maximum power is roughly size-independent, the power itself slightly increases with the dimension, quickly saturating to a constant. Thus, interestingly, scaling up autonomous quantum heat pumps does not render a significant enhancement beyond the optimal double-stage configuration.

  6. Sound absorption with green materials

    Science.gov (United States)

    Trematerra, Amelia; Lombardi, Ilaria

    2017-07-01

    Green materials are a valid alternative to traditional materials that are by-products of processing oil. At the end of their useful life, green materials can be disposed of without polluting the environment. They are now being used in the construction and automotive industries. While, studies are currently being carried out in the aviation sector on the use of green materials for non-structural components of airplanes. Green materials can be used to improve the acoustic comfort inside buildings as well as mitigate reverberation, echoes effects and reduce the transmission of noise between rooms. In this paper, the acoustic measurements of the properties of green materials are reported. The absorption coefficient of samples of the materials were measured in the frequency range from 200 Hz to 2,000 Hz with an impedance tube, with the flow resistance being measured.

  7. Mixture for plugging absorption zones

    Energy Technology Data Exchange (ETDEWEB)

    Sitinkov, G V; Kovalenko, N G; Makarov, L V; Zinnatulchin, Ts Kh

    1981-01-17

    A mixture is proposed for plugging absorption zones. The mixture contains synthetic polymer and a solvent. So as to increase the penetrability of the mixture through a reduction in its viscosity and an increase in insulation properties, the compound contains either Capron or Neilon as the synthetic polyamide resin polmyer, and concentrated chloride as the solvent. The mixture is prepared in a special AzINMASh-30 unit (acid cart). After the mixture has been produced, it is injected into the borehole by means of an acid cart pump. So as to prevent coaggulation at the point when the mixture in injected into the stratum through tubes, the mixture is placed betwen chemically inert fluids, for example, a clay mortar. The inert and compressed fluids are injected by means of a cementing unit. The entire process of production and application of the mixture is simple and fully automated through the use of well-known equipment.

  8. Textural features for image classification

    Science.gov (United States)

    Haralick, R. M.; Dinstein, I.; Shanmugam, K.

    1973-01-01

    Description of some easily computable textural features based on gray-tone spatial dependances, and illustration of their application in category-identification tasks of three different kinds of image data - namely, photomicrographs of five kinds of sandstones, 1:20,000 panchromatic aerial photographs of eight land-use categories, and ERTS multispectral imagery containing several land-use categories. Two kinds of decision rules are used - one for which the decision regions are convex polyhedra (a piecewise-linear decision rule), and one for which the decision regions are rectangular parallelpipeds (a min-max decision rule). In each experiment the data set was divided into two parts, a training set and a test set. Test set identification accuracy is 89% for the photomicrographs, 82% for the aerial photographic imagery, and 83% for the satellite imagery. These results indicate that the easily computable textural features probably have a general applicability for a wide variety of image-classification applications.

  9. Fat absorption in cystic fibrosis mice is impeded by defective lipolysis and post-lipolytic events

    NARCIS (Netherlands)

    Bijvelds, MJC; Bronsveld, [No Value; Havinga, R; Sinaasappel, M; de Jonge, HR; Verkade, HJ

    Cystic fibrosis (CF) is frequently associated with progressive loss of exocrine pancreas function, leading to incomplete digestion and absorption of dietary fat. Supplementing patients with pancreatic lipase reduces fat excretion, but it does not completely correct fat malabsorption, indicating that

  10. Geochemical indicators of gold ore fields

    International Nuclear Information System (INIS)

    Shcherbakov, Yu.G.

    1995-01-01

    The principles of selection of indicators for genetic reconstructions and prognostic valuations of gold mineralization of diverse morphological and geochemical types have been substantiated. The neutron-activation analysis with radiochemical separation and detection limit of 1-10 -8 %, instrumental neutron-activation analysis and atomic-absorption analysis are the main methods of determination of gold low contents in the rocks, as well as diverse elements, including transition, rare earth elements and tellurium, in gold. 50 refs.; 1 fig.; 3 tabs

  11. Geomagnetic Indices Bulletin (GIB)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Geomagnetic Indices Bulletin is a one page sheet containing the magnetic indices Kp, Ap, Cp, An, As, Am and the provisional aa indices. The bulletin is published...

  12. Influence of circulating epinephrine on absorption of subcutaneously injected insulin

    International Nuclear Information System (INIS)

    Fernqvist, E.; Gunnarsson, R.; Linde, B.

    1988-01-01

    Effects of epinephrine (Epi) infusion on the absorption of subcutaneously injected 125I-labeled soluble human insulin (10 U) from the thigh or the abdomen were studied in 16 healthy subjects and from the thigh in 10 insulin-dependent diabetic (IDDM) patients. Epi was infused at 0.3 (high dose) or 0.1 (low dose; healthy subjects) nmol.kg-1.min-1 i.v., resulting in arterial plasma Epi levels of approximately 6 and 2 nM, respectively. Saline was infused on a control day. Insulin absorption was measured as disappearance of radioactivity from the injection site and as appearance of plasma immunoreactive insulin (IRI). Adipose tissue blood flow was measured with the 133Xe clearance technique. First-order disappearance rate constants of 125I from the thigh depot decreased approximately 40-50% during the high dose of Epi compared with control (P less than .001). The corresponding decrease from the abdominal depot was approximately 40% (P less than .001), whereas no significant change was found during the low Epi dose. IRI fell compared with control in all groups at the high Epi dose. The Epi-induced depression of insulin absorption occurred despite unaltered or even slightly increased subcutaneous blood flow. The results indicate that circulating Epi at levels seen during moderate physical stress depresses the absorption of soluble insulin from subcutaneous injection sites to an extent that might be important for glycemic control in IDDM patients. Furthermore, dissociation is found between changes in insulin absorption and subcutaneous blood flow during Epi infusion, suggesting that factors other than blood flow may also influence the absorption of subcutaneously injected insulin

  13. Visual indicator of absorbed radiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Generalova, V V; Krasovitskii, B M; Vainshtok, B A; Gurskii, M N

    1968-10-15

    A visual indicator of the absorbed doses of ionizing radiation is proposed. The indicator has a polymer base with the addition of a dye. A distinctive feature of the indicator consists of the use of polystyrene as its polymer base with the addition of halogen-containing hydrocarbon and the light-proof dye. Such combination of the radiation-resistant polymer of polystyrene and the light-proof dyestuff makes the proposed indicator highly stable.

  14. Narrow absorption lines complex I: one form of broad absorption line

    Science.gov (United States)

    Lu, Wei-Jian; Lin, Ying-Ru

    2018-03-01

    We discover that some of the broad absorption lines (BALs) are actually a complex of narrow absorption lines (NALs). As a pilot study of this type of BAL, we show this discovery through a typical example in this paper. Utilizing the two-epoch observations of J002710.06-094435.3 (hereafter J0027-0944) from the Sloan Digital Sky Survey (SDSS), we find that each of the C IV and Si IV BAL troughs contains at least four NAL doublets. By resolving the Si IV BAL into multiple NALs, we present the following main results and conclusions. First, all these NALs show coordinated variations between the two-epoch SDSS observations, suggesting that they all originate in the quasar outflow, and that their variations are due to global changes in the ionization condition of the absorbing gas. Secondly, a BAL consisting of a number of NAL components indicates that this type of BAL is basically the same as the intrinsic NAL, which tends to support the inclination model rather than the evolution model. Thirdly, although both the C IV and Si IV BALs originate from the same clumpy substructures of the outflow, they show different profile shapes: multiple absorption troughs for the Si IV BAL in a wider velocity range, while P-Cygni for the C IV BAL in a narrower velocity range. This can be interpreted by the substantial differences in fine structure and oscillator strength between the Si IVλλ1393, 1402 and C IVλλ1548, 1551 doublets. Based on the above conclusions, we consider that the decomposition of a BAL into NALs can serve as a way to resolve the clumpy structure for outflows, and it can be used to learn more about characteristics of the clumpy structure and to test the outflow model, when utilizing high-resolution spectra and photoionization model.

  15. Phytosterol glycosides reduce cholesterol absorption in humans

    OpenAIRE

    Lin, Xiaobo; Ma, Lina; Racette, Susan B.; Anderson Spearie, Catherine L.; Ostlund, Richard E.

    2009-01-01

    Dietary phytosterols inhibit intestinal cholesterol absorption and regulate whole body cholesterol excretion and balance. However, they are biochemically heterogeneous and a portion is glycosylated in some foods with unknown effects on biological activity. We tested the hypothesis that phytosterol glycosides reduce cholesterol absorption in humans. Phytosterol glycosides were extracted and purified from soy lecithin in a novel two-step process. Cholesterol absorption was measured in a series ...

  16. Vitamin B12 absorption from eggs.

    Science.gov (United States)

    Doscherholmen, A; McMahon, J; Ripley, D

    1975-09-01

    The assimilation of 57Co B12 from in vivo labeled eggs was much inferior to that of a comparable amount of crystalline 57Co B12. Furthermore, the absorption varied with the form in which the eggs were served. Judged by the urinary excretion test and the plasma absorption of radioactivity the average absorption from boiled and fried eggs was more than twice that from scrambled whole eggs, but less than half that absorbed from crystalline 57Co B12.

  17. Flame emission, atomic absorption and fluorescence spectrometry

    International Nuclear Information System (INIS)

    Horlick, G.

    1980-01-01

    Six hundred and thirty references are cited in this review. The information in the review is divided into 12 major areas: books, reviews, and bibliographies; fundamental studies in flames; developments in instrumentation; measurement techniques and procedure; flame emission spectrometry; flame atomic absorption spectrometry; flame molecular absorption spectrometry; electrothermal atomization atomic absorption spectroscopy; hydride generation techniques; graphite furnace atomic emission spectrometry; atomic fluorescence spectrometry; and analytical comparisons

  18. Emission and Absorption Entropy Generation in Semiconductors

    DEFF Research Database (Denmark)

    Reck, Kasper; Varpula, Aapo; Prunnila, Mika

    2013-01-01

    While emission and absorption entropy generation is well known in black bodies, it has not previously been studied in semiconductors, even though semiconductors are widely used for solar light absorption in modern solar cells [1]. We present an analysis of the entropy generation in semiconductor...... materials due to emission and absorption of electromagnetic radiation. It is shown that the emission and absorption entropy generation reduces the fundamental limit on the efficiency of any semiconductor solar cell even further than the Landsberg limit. The results are derived from purely thermodynamical...

  19. X-ray absorption in atomic potassium

    International Nuclear Information System (INIS)

    Gomilsek, Jana Padeznik; Kodre, Alojz; Arcon, Iztok; Nemanic, Vincenc

    2008-01-01

    A new high-temperature absorption cell for potassium vapor is described. X-ray absorption coefficient of atomic potassium is determined in the energy interval of 600 eV above the K edge where thresholds for simultaneous excitations of 1s and outer electrons, down to [1s2p] excitation, appear. The result represents also the atomic absorption background for XAFS (X-ray absorption fine structure) structure analysis. The K ionization energy in the potassium vapor is determined and compared with theoretical data and with the value for the metal

  20. β Absorption dust concentration monitor system based on the PLC

    International Nuclear Information System (INIS)

    Lian Dexing; Zhou Xiuliang; Liu Liyan; Li Zonglun; Cao Guanghui; Mao Wanchong

    2011-01-01

    To provide an on-line automatic system for dust concentration monitor is the purpose of this design.The system based on β-ray-absorption-method,employing PLC (Programmable Logic Controller) control technology, is presented. The user input parameter setup,the data acquisition and processing, and the communication with computer can be effectively regulated using the advanced PLC control technology. It has the features of high reliability, easy operation and easy maintenance, and the ability to monitor remotely. Measurement range: 0.1-1500 mg/m 3 , Accuracy: ±9%. The structure,working principle, electric circuit and software development of the system are introduced in detail. (authors)

  1. Ultrafast Transient Absorption Spectroscopy Investigation of Photoinduced Dynamics in Novel Donor-Acceptor Core-Shell Nanostructures for Organic Photovoltaics

    Science.gov (United States)

    Strain, Jacob; Jamhawi, Abdelqader; Abeywickrama, Thulitha M.; Loomis, Wendy; Rathnayake, Hemali; Liu, Jinjun

    2016-06-01

    Novel donor-acceptor nanostructures were synthesized via covalent synthesis and/or UV cross-linking method. Their photoinduced dynamics were investigated with ultrafast transient absorption (TA) spectroscopy. These new nanostructures are made with the strategy in mind to reduce manufacturing steps in the process of fabricating an organic photovoltaic cell. By imitating the heterojunction interface within a fixed particle domain, several fabrication steps can be bypassed reducing cost and giving more applicability to other film deposition methods. Such applications include aerosol deposition and ink-jet printing. The systems that were studied by TA spectroscopy include PDIB core, PDIB-P3HT core-shell, and PDIB-PANT core-shell which range in size from 60 to 130 nm. Within the experimentally accessible spectra range there resides a region of ground state bleaching, stimulated emission, and excited-state absorption of both neutrals and anions. Control experiments have been carried out to assign these features. At high pump fluences the TA spectra of PDIB core alone also indicate an intramolecular charge separation. The TA spectroscopy results thus far suggest that the core-shells resemble the photoinduced dynamics of a standard film although the particles are dispersed in solution, which indicates the desired outcome of the work.

  2. Personality Features of Motorists

    Directory of Open Access Journals (Sweden)

    Andrej Justinek

    1997-12-01

    Full Text Available Justinek tries to answer the question whether or not motorists have specific personality features which predispose them for safe and well-mannered driving. A good driver should have sensory abilities which enable psycho-motor coordiation of a vehicle, intellectual and cognitive features that are important for solving problems in new, unknown situations, and emotional and motivational trails defining a driver's maturity. Justmek advocates the belief that in training future drivers greater attention should be paid to developing these features which are vital for safe driving and appropriate behaviour of drivers in traffic. He also suggests certain learning methods leading to development of the above­ mentioned personality traits. Justinek introduces the notion of the 'philosophy of driving' as an essential educational category in training future drivers.

  3. Feature displacement interpolation

    DEFF Research Database (Denmark)

    Nielsen, Mads; Andresen, Per Rønsholt

    1998-01-01

    Given a sparse set of feature matches, we want to compute an interpolated dense displacement map. The application may be stereo disparity computation, flow computation, or non-rigid medical registration. Also estimation of missing image data, may be phrased in this framework. Since the features...... often are very sparse, the interpolation model becomes crucial. We show that a maximum likelihood estimation based on the covariance properties (Kriging) show properties more expedient than methods such as Gaussian interpolation or Tikhonov regularizations, also including scale......-selection. The computational complexities are identical. We apply the maximum likelihood interpolation to growth analysis of the mandibular bone. Here, the features used are the crest-lines of the object surface....

  4. Energy absorption capabilities of composite sandwich panels under blast loads

    Science.gov (United States)

    Sankar Ray, Tirtha

    , ET) was suggested to compare energy absorption capabilities of the structures under blast loading. In addition, AEweb/ET (where AEweb is the energy absorbed by the middle core) was also employed to evaluate the energy absorption contribution from the web. Taking advantage of FEA and the simplified analytical model, the influences of material properties as well as core architectures and geometries on energy absorption capabilities (quantified by AET/ ET and AEweb/E T) were investigated through parametric studies. Results from the material property investigation indicated that density of the front face sheet and strength were most influential on the energy absorption capability of the composite sandwich panels under blast loading. The study to investigate the potential effectiveness of energy absorbed via inelastic deformation compared to energy absorbed via progressive failure indicated that for practical applications (where the position of bomb is usually unknown and the panel is designed to be the same anywhere), the energy absorption via inelastic deformation is the more efficient approach. Regarding the geometric optimization, it was found that a core architecture consisting of vertically-oriented webs was ideal. The optimum values for these parameters can be generally described as those which cause the most inelasticity, but not failure, of the face sheets and webs.

  5. Particulate absorption properties in the Red Sea from hyperspectral particulate absorption spectra

    KAUST Repository

    Tiwari, Surya Prakash; Zarokanellos, Nikolaos; Kheireddine, Malika; Shanmugam, Palanisamy; Jones, Burton

    2018-01-01

    This paper aims to describe the variability of particulate absorption properties using a unique hyperspectral dataset collected in the Red Sea as part of the TARA Oceans expedition. The absorption contributions by phytoplankton (aph) and non

  6. Sexual dimorphism in medulloblastoma features.

    Science.gov (United States)

    Zannoni, Gian Franco; Ciucci, Alessandra; Marucci, Gianluca; Travaglia, Daniele; Stigliano, Egidio; Foschini, Maria Pia; Scambia, Giovanni; Gallo, Daniela

    2016-03-01

    Male sex is a risk factor for medulloblastoma (MB), and is also a negative predictor for clinical outcome. The aim of this study was to assess sex differences in tumour biological features and hormone receptor profiles in a cohort of MB patients. Sixty-four MBs and five normal cerebella were included in the study. Cell proliferation (Ki67), apoptosis (cleaved caspase-3) and microvessel density (CD31) were evaluated in tumours by immunohistochemistry. Tissues were analysed for oestrogen receptor (ER)α, ERβ1, ERβ2, ERβ5 and androgen receptor (AR) expression. The results demonstrated sex-specific features in MBs, with tumours from females showing a higher apoptosis/proliferation ratio and less tumour vascularization than tumours from males. MBs were negative for ERα and AR, but expressed ERβ isoforms at similar levels between the sexes. Altogether, these findings indicate that signalling mechanisms that control cell turnover and angiogenesis operate more efficiently in females than in males. The lack of sex differences in the hormone receptor profiles suggests that circulating oestrogens could be the major determinants of the sexual dimorphism observed in MB features. Here, we provide molecular support for epidemiological data showing sex differences in MB incidence and outcome, completely defining the hormone receptor profile of the tumours. © 2015 John Wiley & Sons Ltd.

  7. Near-infrared diode laser absorption diagnostic for temperature and water vapor in a scramjet combustor

    International Nuclear Information System (INIS)

    Liu, Jonathan T.C.; Rieker, Gregory B.; Jeffries, Jay B.; Gruber, Mark R.; Carter, Campbell D.; Mathur, Tarun; Hanson, Ronald K.

    2005-01-01

    Tunable diode laser absorption measurements of gas temperature and water concentration were made at the exit of a model scramjet combustor fueled on JP-7. Multiplexed, fiber-coupled, near-infrared distributed feedback lasers were used to probe three water vapor absorption features in the 1.34-1.47 μm spectral region (2v1and v1+ v3overtone bands). Ratio thermometry was performed using direct-absorption wavelength scans of isolated features at a 4-kHz repetition rate, as well as 2f wavelength modulation scans at a 2-kHz scan rate. Large signal-to-noise ratios demonstrate the ability of the optimally engineered optical hardware to reject beam steering and vibration noise. Successful measurements were made at full combustion conditions for a variety of fuel/air equivalence ratios and at eight vertical positions in the duct to investigate spatial uniformity. The use of three water vapor absorption features allowed for preliminary estimates of temperature distributions along the line of sight. The improved signal quality afforded by 2f measurements, in the case of weak absorption, demonstrates the utility of a scanned wavelength modulation strategy in such situations

  8. In vitro and in vivo percutaneous absorption of retinol from cosmetic formulations: Significance of the skin reservoir and prediction of systemic absorption

    International Nuclear Information System (INIS)

    Yourick, Jeffrey J.; Jung, Connie T.; Bronaugh, Robert L.

    2008-01-01

    The percutaneous absorption of retinol (Vitamin A) from cosmetic formulations was studied to predict systemic absorption and to understand the significance of the skin reservoir in in vitro absorption studies. Viable skin from fuzzy rat or human subjects was assembled in flow-through diffusion cells for in vitro absorption studies. In vivo absorption studies using fuzzy rats were performed in glass metabolism cages for collection of urine, feces, and body content. Retinol (0.3%) formulations (hydroalcoholic gel and oil-in-water emulsion) containing 3 H-retinol were applied and absorption was measured at 24 or 72 h. All percentages reported are % of applied dose. In vitro studies using human skin and the gel and emulsion vehicles found 0.3 and 1.3% retinol, respectively, in receptor fluid at 24 h. Levels of absorption in the receptor fluid increased over 72 h with the gel and emulsion vehicles. Using the gel vehicle, in vitro rat skin studies found 23% in skin and 6% in receptor fluid at 24 h, while 72-h studies found 18% in skin and 13% in receptor fluid. Thus, significant amounts of retinol remained in rat skin at 24 h and decreased over 72 h, with proportional increases in receptor fluid. In vivo rat studies with the gel found 4% systemic absorption of retinol after 24 h and systemic absorption did not increase at 72 h. Retinol remaining in rat skin after in vivo application was 18% and 13% of the applied dermal dose after 24 and 72 h, respectively. Similar observations were made with the oil-in water emulsion vehicle in the rat. Retinol formed a reservoir in rat skin both in vivo and in vitro. Little additional retinol was bioavailable after 24 h. Comparison of these in vitro and in vivo results for absorption through rat skin indicates that the 24-h in vitro receptor fluid value accurately estimated 24-h in vivo systemic absorption. Therefore, the best single estimate of retinol systemic absorption from in vitro human skin studies is the 24-h receptor fluid

  9. Infrared multiphoton absorption and decomposition

    International Nuclear Information System (INIS)

    Evans, D.K.; McAlpine, R.D.

    1984-01-01

    The discovery of infrared laser induced multiphoton absorption (IRMPA) and decomposition (IRMPD) by Isenor and Richardson in 1971 generated a great deal of interest in these phenomena. This interest was increased with the discovery by Ambartzumian, Letokhov, Ryadbov and Chekalin that isotopically selective IRMPD was possible. One of the first speculations about these phenomena was that it might be possible to excite a particular mode of a molecule with the intense infrared laser beam and cause decomposition or chemical reaction by channels which do not predominate thermally, thus providing new synthetic routes for complex chemicals. The potential applications to isotope separation and novel chemistry stimulated efforts to understand the underlying physics and chemistry of these processes. At ICOMP I, in 1977 and at ICOMP II in 1980, several authors reviewed the current understandings of IRMPA and IRMPD as well as the particular aspect of isotope separation. There continues to be a great deal of effort into understanding IRMPA and IRMPD and we will briefly review some aspects of these efforts with particular emphasis on progress since ICOMP II. 31 references

  10. Controlling coulomb interactions in infrared stereometamaterials for unity light absorption

    Science.gov (United States)

    Mudachathi, Renilkumar; Moritake, Yuto; Tanaka, Takuo

    2018-05-01

    We investigate the influence of near field interactions between the constituent 3D split ring resonators on the absorbance and resonance frequency of a stereo metamaterial based perfect light absorber. The experimental and theoretical analyses reveal that the magnetic resonance red shifts and broadens for both the decreasing vertical and lateral separations of the constituents within the metamaterial lattice, analogous to plasmon hybridization. The strong interparticle interactions for higher density reduce the effective cross-section per resonator, which results in weak light absorption observed in both experimental and theoretical analyses. The red shift of the magnetic resonance with increasing lattice density is an indication of the dominating electric dipole interactions and we analyzed the metamaterial system in an electrostatic point of view to explain the observed resonance shift and decreasing absorption peak. From these analyses, we found that the fill factor introduces two competing factors determining the absorption efficiency such as coulomb interactions between the constituent resonators and their number density in a given array structure. We predicted unity light absorption for a fill factor of 0.17 balancing these two opposing factors and demonstrate an experimental absorbance of 99.5% at resonance with our 3D device realized using residual stress induced bending of 2D patterns.

  11. Absorption correction factor in X-ray fluorescent quantitative analysis

    International Nuclear Information System (INIS)

    Pimjun, S.

    1994-01-01

    An experiment on absorption correction factor in X-ray fluorescent quantitative analysis were carried out. Standard samples were prepared from the mixture of Fe 2 O 3 and tapioca flour at various concentration of Fe 2 O 3 ranging from 5% to 25%. Unknown samples were kaolin containing 3.5% to-50% of Fe 2 O 3 Kaolin samples were diluted with tapioca flour in order to reduce the absorption of FeK α and make them easy to prepare. Pressed samples with 0.150 /cm 2 and 2.76 cm in diameter, were used in the experiment. Absorption correction factor is related to total mass absorption coefficient (χ) which varied with sample composition. In known sample, χ can be calculated by conveniently the formula. However in unknown sample, χ can be determined by Emission-Transmission method. It was found that the relationship between corrected FeK α intensity and contents of Fe 2 O 3 in these samples was linear. This result indicate that this correction factor can be used to adjust the accuracy of X-ray intensity. Therefore, this correction factor is essential in quantitative analysis of elements comprising in any sample by X-ray fluorescent technique

  12. Absorber performance of a water/lithium-bromide absorption chiller

    International Nuclear Information System (INIS)

    Xie Guozhen; Sheng Guogang; Bansal, Pradeep Kumar; Li, Guang

    2008-01-01

    An absorber is one of the most important components of a lithium-bromide absorption chiller (LBAC) as its absorbing characteristics directly influence the performance of the whole chiller. It has been indicated that the absorbing efficiency and cooling capacity could be improved by increasing the solution concentration. In this paper, based on the mechanism of falling film absorption on horizontal tubes, the theoretical models of falling film absorption on horizontal tubes have been established. A series of programs used for computing the theoretical mathematical models, including simulation of LBAC cycle and falling film absorption, have been programmed. The models have been validated reasonably by the experimental data. The results show that the cooling capacity of the LBAC varies in parabola shape of curve with the solution concentration from 52.5% to 58.5%, and that the best coefficient of performance (COP) occurs at concentration of 57%. The investigation proposes the absorbing process of sub-steady thermodynamic equilibrium for the duality solution under increase absorbing pressure

  13. Terahertz absorption signatures of lactose monohydrate in crystalline form

    International Nuclear Information System (INIS)

    Jung, Euna; Kim, Jeonghoi; Han, Younho; Moon, Kiwon; Lim, Meehyun; Han, Haewook

    2008-01-01

    Terahertz (THz)vibrational modes of biomolecules strongly depend on intermolecular interactions, including electrostatic, Van der Waals, and hydrogen bonds. Upon both the theoretical and experimental investigation of vibrational dynamics in biomolecules that have been done, it is turned out that low frequency vibrational modes of biomolecules exist in 0.1∼3.0THz. Recent advances of THz technology have paved the way for a wide range of practical applications in physics, chemistry, and biology. THz time domain spectroscopy (TDS)is a promising technique for studying the collective vibrational modes of biomolecules and is important to understanding the relationship between their conformation and biological function. Using THz TDS a variety of biomolecules, including DNA, polysaccharides, amino acids, and proteins have been studied, indicating the THz absorption spectroscopy can be used to probe the collective vibrational modes and hence for structural and functional studies of biomolecules. The diluted material was then pressed into 1mm thick pellet with 13mm diameter using a vacuum die. The low frequency absorption signatures of solid α lactose monohydrate have been experimentally obtained in 0.1∼2.0THz. Previous study has already reported that α lactose monohydrate in crystalline form has a strong and narrow absorption signature centered at 0.530THz. In our measurement, we observed that THz spectrum of α lactose monohydrate has strong absorption peaks centered at 0.531, 1.195, and 1.38 THz

  14. Intestinal absorption of chromium as affected by wheat bran

    International Nuclear Information System (INIS)

    Keim, K.S.; Holloway, C.L.; Hegsted, M.

    1986-01-01

    This study was designed to investigate the influence of dietary fiber, as found in wheat bran, on the absorption of chromium. Twenty male Sprague-Dawley rats were divided into two groups of 10. The control was fed a semi-purified diet containing casein, methionine, cornstarch, sucrose, corn oil, mineral and vitamin mix, and choline bitartrate. The experimental group was fed the same diet but with soft red winter wheat bran added to a level of 35% of the diet at the expense of sucrose. To determine chromium absorption and uptake by selected tissues, rats were fasted for 24 hr, fed 5 g of the respective diet, 2 hr later intubated with 100μCi of Cr-51of sacrificed 24 hr later. The rats wee housed in metabolic cages after the Cr-51 intubation. The addition of wheat brand to the diet did not significantly affect chromium absorption as measured by percent dose of Cr-51 in the 24 hr urine. The percent dose in the control group was 0.68 +/- 0.20% (mean +/- SEM) and in the experimental group 0.63 +/- 0.24% (mean +/-SEM) (N.S.). The cr-51 uptake of liver, spleen, jejunum, and blood was not statistically different between groups. These results indicate that dietary fiber as found in wheat bran does not impair intestinal absorption of chromium

  15. Engineering features of ISX

    International Nuclear Information System (INIS)

    Lousteau, D.C.; Jernigan, T.C.; Schaffer, M.J.; Hussung, R.O.

    1975-01-01

    ISX, an Impurity Study Experiment, is presently being designed at Oak Ridge National Laboratory as a joint scientific effort between ORNL and General Atomic Company. ISX is a moderate size tokamak dedicated to the study of impurity production, diffusion, and control. The significant engineering features of this device are discussed

  16. Estimation of water absorption coefficient using the TDR method

    Science.gov (United States)

    Suchorab, Zbigniew; Majerek, Dariusz; Brzyski, Przemysław; Sobczuk, Henryk; Raczkowski, Andrzej

    2017-07-01

    Moisture accumulation and transport in the building barriers is an important feature that influences building performance, causing serious exploitation problems as increased energy use, mold and bacteria growth, decrease of indoor air parameters that may lead to sick building syndrome (SBS). One of the parameters that is used to describe moisture characteristic of the material is water absorption coefficient being the measure of capillary behavior of the material as a function of time and the surface area of the specimen. As usual it is determined using gravimetric methods according to EN 1925:1999 standard. In this article we demonstrate the possibility of determination of water absorption coefficient of autoclaved aerated concrete (AAC) using the Time Domain Reflectometry (TDR) method. TDR is an electric technique that had been adopted from soil science and can be successfully used for real-time monitoring of moisture transport in building materials and envelopes. Data achieved using TDR readouts show high correlation with standard method of moisture absorptivity coefficient determination.

  17. A Low-Cost Quantitative Absorption Spectrophotometer

    Science.gov (United States)

    Albert, Daniel R.; Todt, Michael A.; Davis, H. Floyd

    2012-01-01

    In an effort to make absorption spectrophotometry available to high school chemistry and physics classes, we have designed an inexpensive visible light absorption spectrophotometer. The spectrophotometer was constructed using LEGO blocks, a light emitting diode, optical elements (including a lens), a slide-mounted diffraction grating, and a…

  18. Spectral interferences in atomic absorption spectrometry, (5)

    International Nuclear Information System (INIS)

    Daidoji, Hidehiro

    1979-01-01

    Spectral interferences were observed in trace element analysis of concentrated solutions by atomic absorption spectrometry. Molecular absorption and emission spectra for strontium chloride and nitrate, barium chloride and nitrate containing 12 mg/ml of metal ion in airacetylene flame were measured in the wavelength range from 200 to 700 nm. The absorption and emission spectra of SrO were centered near 364.6 nm. The absorption spectra of SrOH around 606.0, 671.0 and 682.0 nm were very strong. And, emission spectrum of BaOH in the wavelength range from 480 to 550 nm was stronger. But, the absorption of this band spectrum was very weak. In the wavelength range from 200 to 400 nm, some unknown bands of absorption were observed for strontium and barium. Absorption spectra of SrCl and BaCl were observed in the argon-hydrogen flame. Also, in the carbon tube atomizer, the absorption spectra of SrCl and BaCl were detected clearly in the wavelength range from 185 to 400 nm. (author)

  19. Process for neptunium analysis by absorption spectrophotometry

    International Nuclear Information System (INIS)

    Wagner, J.F.

    1987-01-01

    An aqueous solution of a neptunium compounds is treated by a reagent, preferentially a vanadyl sulfate oxidized by cerium IV ions, to obtain neptunium V by oxidation of neptunium IV and reduction of neptunium VI. The reagent is chosen for a negligible absorption at the wavelength used for neptunium V absorption spectrophotometry for instance 981 nm [fr

  20. Photoelectric absorption cross sections with variable abundances

    Science.gov (United States)

    Balucinska-Church, Monika; Mccammon, Dan

    1992-01-01

    Polynomial fit coefficients have been obtained for the energy dependences of the photoelectric absorption cross sections of 17 astrophysically important elements. These results allow the calculation of X-ray absorption in the energy range 0.03-10 keV in material with noncosmic abundances.

  1. Anomalous infrared absorption in granular superconductors

    International Nuclear Information System (INIS)

    Carr, G.L.; Garland, J.C.; Tanner, D.B.

    1983-01-01

    Granular superconductors are shown to have a far-infrared absorption that is larger when the samples are superconducting than when they are normal. By constrast, theoretical models for these materials predict that when the samples become superconducting, the absorption should decrease

  2. Cimetidine absorption in humans during sucralfate coadministration.

    OpenAIRE

    D'Angio, R; Mayersohn, M; Conrad, K A; Bliss, M

    1986-01-01

    Cimetidine absorption after a single 300 mg oral dose was evaluated in six normal subjects in the absence or presence of sucralfate. Sucralfate was ingested four times a day for 2 days prior to and for two additional doses on the day of cimetidine ingestion. Sucralfate coadministration had no statistically significant influence on the rate or extent of cimetidine absorption.

  3. Ultrafast THz Saturable Absorption in Semiconductors

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hoffmann, Matthias C.

    2011-01-01

    We demonstrate THz saturable absorption in n-doped semiconductors GaAs, GaP, and Ge in a nonlinear THz time-domain spectroscopy experiment. Saturable absorption is caused by sample conductivity modulation due to electron heating and satellite valley scattering in the field of a strong THz pulse....

  4. Unveiling the Microfoundations of Absorptive Capacity

    DEFF Research Database (Denmark)

    Distel, Andreas Philipp

    2017-01-01

    to absorptive capacity at the organizational level and that this relationship is mediated through a microlevel process. The findings reveal that knowledge workers’ cognitive process of perspective taking and their creative behavior are important microfoundations of absorptive capacity. Moreover, the results...... emphasize the critical role of key employees in explaining firm-level heterogeneity in building organizational capabilities....

  5. Oligofructose stimulates calcium absorption in adolescents

    NARCIS (Netherlands)

    Heuvel, E.G.H.M. van den; Muys, T.; Dokkum, W. van; Schaafsma, G.

    1999-01-01

    Background: In rats, nondigestible oligosaccharides stimulate calcium absorption. Recently, this effect was also found in human subjects. Objective: The objective of the study was to investigate whether consumption of 15 g oligofructose/d stimulates calcium absorption in male adolescents. Design:

  6. A transient absorption study of allophycocyanin

    Indian Academy of Sciences (India)

    Transient dynamics of allophycocyanin trimers and monomers are observed by using the pump-probe, transient absorption technique. The origin of spectral components of the transient absorption spectra is discussed in terms of both kinetics and spectroscopy. We find that the energy gap between the ground and excited ...

  7. Valence-to-core-detected X-ray absorption spectroscopy

    DEFF Research Database (Denmark)

    Hall, Eleanor R.; Pollock, Christopher J.; Bendix, Jesper

    2014-01-01

    X-ray absorption spectroscopy (XAS) can provide detailed insight into the electronic and geometric structures of transition-metal active sites in metalloproteins and chemical catalysts. However, standard XAS spectra inherently represent an average contribution from the entire coordination...... environment with limited ligand selectivity. To address this limitation, we have investigated the enhancement of XAS features using valence-to-core (VtC)-detected XAS, whereby XAS spectra are measured by monitoring fluorescence from valence-to-core X-ray emission (VtC XES) events. VtC emission corresponds...... to transitions from filled ligand orbitals to the metal 1s core hole, with distinct energetic shifts for ligands of differing ionization potentials. VtC-detected XAS data were obtained from multiple valence emission features for a series of well-characterized Mn model compounds; taken together, these data...

  8. Ultra-bright red-emitting photostable perylene bisimide dyes: new indicators for ratiometric sensing of high pH or carbon dioxide.

    Science.gov (United States)

    Pfeifer, David; Klimant, Ingo; Borisov, Sergey M

    2018-05-08

    New pH sensitive perylene bisimide indicator dyes were synthesised and used for fabrication of optical sensors. The highly photostable dyes show absorption/emission bands in the red/near-infrared (NIR) region of the electromagnetic spectrum, high molar absorption coefficients (up to 100 000 M-1 cm-1) and fluorescence quantum yields close to unity. The absorption and emission spectra show strong bathochromic shift upon deprotonation of imidazole nitrogen which makes the dyes promising as ratiometric fluorescent indicators. Physical entrapment of the indicators into polyurethane hydrogel enables pH determination in alkaline pH. It is also shown that plastic carbon dioxide solid state sensor can be manufactured via immobilization of the pH indicator in a hydrophilic polymer, along with a quaternary ammonium base. The influence of plasticizer, different lipophilic bases and humidity on the sensitivity of the sensor material were systematically investigated. The disubstituted perylene, particularly, features two deprotonation equilibria enabling sensing over a very broad range from 0.5 to 1000 hPa pCO2. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Absorption of controlled-release iron

    International Nuclear Information System (INIS)

    Cook, J.D.; Lipschitz, D.A.; Skikne, B.S.

    1982-01-01

    A multiple-dose double radioiron technic was used to compare absorption of iron administered as a controlled release (CR) capsule and as an elixir; both formulations contained 50 mg elemental iron as ferrous sulfate. When taken by normal subjects in the fasting state, mean absorption from the elixir and CR capsule averaged 4.92% and 4.38%, which gave a CR capsule:elixir ratio of 0.89. This difference was not significant, but when taken with meals that inhibit absorption of dietary iron by different degrees, absorption of the CR formulation was superior. CR capsule:elixir absorption ratios averaged 1.70 from a meal that is mildly inhibitory and 3.13 from a meal that causes more marked inhibition. It is concluded that CR iron formulations may offer a therapeutic advantage to patients who take oral iron with meals to avoid gastrointestinal side effects

  10. Indicators and their functions

    DEFF Research Database (Denmark)

    Gudmundsson, Henrik; Joumard, Robert; Aschemann, Ralf

    2010-01-01

    indicators? How can several indicators be jointly considered? And how can indicators be used in planning and decision making? Firstly we provide definition of 'indicator of environmental sustainability in transport'. The functions, strengths and weaknesses of indicators as measurement tools, and as decision...... for indicators and assessments. As the decision making context influences the perceived and actual needs for indicators and methods, we also analysed the dimensions and context of decision making. We derived criteria and methods for the assessment and selection of indicators of environmental sustainability......This report is the final report of the action COST 356 'EST - Towards the definition of a measurable environmentally sustainable transport'. It tries to answer the following questions: How can environmental impacts of transport be measured? How can measurements be transformed into operational...

  11. Geomagnetic aa Indices

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The geomagnetic aa indices are the continuation of the series beginning in the year 1868. A full description of these indices is given in the International...

  12. Climate indices for vulnerability assessments

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Gunn; Baerring, Lars; Kjellstroem, Erik; Strandberg, Gustav; Rummuk ainen, Markku

    2007-08-15

    The demand is growing for practical information on climate projections and the impacts expected in different geographical regions and different sectors. It is a challenge to transform the vast amount of data produced in climate models into relevant information for climate change impact studies. Climate indices based on climate model data can be used as means to communicate climate change impact relations. In this report a vast amount of results is presented from a multitude of indices based on different regional climate scenarios. The regional climate scenarios described in this report show many similarities with previous scenarios in terms of general evolution and amplitude of future European climate change. The broad features are manifested in increases in warm and decreases in cold indices. Likewise are presented increases in wet indices in the north and dry indices in the south. Despite the extensive nature of the material presented, it does not cover the full range of possible climate change. We foresee a continued interactive process with stakeholders as well as continued efforts and updates of the results presented in the report.

  13. Effect of microplastic deformation on the electron ultrasonic absorption in high-purity molybdenum monocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Pal' -Val' , P.P.; Kaufmann, Kh.J.

    1983-03-01

    The low temperature (100-6 K) linear absorption of ultrasound (88 kHz) by high purity molybdenum single crystals have been studied. Both unstrained samples and samples sub ected to microplastic deformation (epsilon<=0.45%) were used. Unstrained samples displayed at T<30 K a rapid increase in the absorption with lowering temperature which is interpreted as an indication of electron viscosity due to electron-phonon collisions. After deformation this part of absorption disappeared. This seems to suggest that microplastic deformation brings about in the crystal a sufficiently large number of defects that can compete with phonons in restricting the electron mean free path. A low temperature dynamic annealing has been revealed in strained samples, that is almost complete recovery of the absorption nature under irradiation with high amplitude sound, epsilon/sub 0/ approximately 10/sup -4/, during 10 min, at 6 K. A new relaxation peak of absorption at 10 K has been found in strained samples.

  14. Associated HI Absorption in the z = 3.4 Radio Galaxy B2 0902 + 343 ...

    Indian Academy of Sciences (India)

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

    of star formation (Einsenhardt & Dickinson 1992). The spatial ... on the blue-ward side of the narrow absorption feature has been reported by ..... associated with a merging galaxy located near the hot spot or dwarf galaxy along the line of sight ...

  15. Energy absorption and failure response of silk/epoxy composite square tubes: Experimental

    DEFF Research Database (Denmark)

    Oshkovr, Simin Ataollahi; Taher, Siavash Talebi; A. Eshkoor, Rahim

    2012-01-01

    This paper focuses on natural silk/epoxy composite square tubes energy absorption and failure response. The tested specimens were featured by a material combination of different lengths and same numbers of natural silk/epoxy composite layers in form of reinforced woven fabric in thermosetting epoxy...

  16. Mid-IR Absorption Cross-Section Measurements of Hydrocarbons

    KAUST Repository

    Alrefae, Majed Abdullah

    2013-05-01

    Laser diagnostics are fast-response, non-intrusive and species-specific tools perfectly applicable for studying combustion processes. Quantitative measurements of species concentration and temperature require spectroscopic data to be well-known at combustion-relevant conditions. Absorption cross-section is an important spectroscopic quantity and has direct relation to the species concentration. In this work, the absorption cross-sections of basic hydrocarbons are measured using Fourier Transform Infrared (FTIR) spectrometer, tunable Difference Frequency Generation laser and fixed wavelength helium-neon laser. The studied species are methane, methanol, acetylene, ethylene, ethane, ethanol, propylene, propane, 1-butene, n-butane, n-pentane, n-hexane, and n-heptane. The Fourier Transform Infrared (FTIR) spectrometer is used for the measurements of the absorption cross-sections and the integrated band intensities of the 13 hydrocarbons. The spectral region of the spectra is 2800 – 3400 cm-1 (2.9 – 3.6 μm) and the temperature range is 673 – 1100 K. These valuable data provide huge opportunities to select interference-free wavelengths for measuring time-histories of a specific species in a shock tube or other combustion systems. Such measurements can allow developing/improving chemical kinetics mechanisms by experimentally determining reaction rates. The Difference Frequency Generation (DFG) laser is a narrow line-width, tunable laser in the 3.35 – 3.53 μm wavelength region which contains strong absorption features for most hydrocarbons due to the fundamental C-H vibrating stretch. The absorption cross-sections of propylene are measured at seven different wavelengths using the DFG laser. The temperature range is 296 – 460 K which is reached using a Reflex Cell. The DFG laser is very attractive for kinetic studies in the shock tube because of its fast time response and the potential possibility of making species-specific measurements. The Fixed wavelength

  17. Constraining Cometary Crystal Shapes from IR Spectral Features

    Science.gov (United States)

    Wooden, D. H.; Lindsay, S.; Harker, D. E.; Kelley, M. S.; Woodward, C. E.; Murphy, J. R.

    2013-12-01

    A major challenge in deriving the silicate mineralogy of comets is ascertaining how the anisotropic nature of forsterite crystals affects the spectral features' wavelength, relative intensity, and asymmetry. Forsterite features are identified in cometary comae near 10, 11.05-11.2, 16, 19, 23.5, 27.5 and 33 μm [1-10], so accurate models for forsterite's absorption efficiency (Qabs) are a primary requirement to compute IR spectral energy distributions (SEDs, λFλ vs. λ) and constrain the silicate mineralogy of comets. Forsterite is an anisotropic crystal, with three crystallographic axes with distinct indices of refraction for the a-, b-, and c-axis. The shape of a forsterite crystal significantly affects its spectral features [13-16]. We need models that account for crystal shape. The IR absorption efficiencies of forsterite are computed using the discrete dipole approximation (DDA) code DDSCAT [11,12]. Starting from a fiducial crystal shape of a cube, we systematically elongate/reduce one of the crystallographic axes. Also, we elongate/reduce one axis while the lengths of the other two axes are slightly asymmetric (0.8:1.2). The most significant grain shape characteristic that affects the crystalline spectral features is the relative lengths of the crystallographic axes. The second significant grain shape characteristic is breaking the symmetry of all three axes [17]. Synthetic spectral energy distributions using seven crystal shape classes [17] are fit to the observed SED of comet C/1995 O1 (Hale-Bopp). The Hale-Bopp crystalline residual better matches equant, b-platelets, c-platelets, and b-columns spectral shape classes, while a-platelets, a-columns and c-columns worsen the spectral fits. Forsterite condensation and partial evaporation experiments demonstrate that environmental temperature and grain shape are connected [18-20]. Thus, grain shape is a potential probe for protoplanetary disk temperatures where the cometary crystalline forsterite formed. The

  18. Performance of iodide vapour absorption in the venturi scrubber working in self-priming mode

    International Nuclear Information System (INIS)

    Zhou, Yanmin; Sun, Zhongning; Gu, Haifeng; Miao, Zhuang

    2016-01-01

    Highlights: • The absorption performance for iodide vapour was studied under different conditions. • A mathematical model was developed to describe the iodide absorption process. • The venturi scrubber can ensure absorption efficiiency and reduce pressure loss. - Abstract: The self-priming venturi scrubber is the key component of filtered containment venting systems for the removal of radioactive products during severe accidents in nuclear power plants. This paper is focused on the absorption performance of iodide vapour in the venturi scrubber, based on experiment and mathematical calculation. The results indicate that the absorption efficiency is closely related to solution flow rate, gas flow rate and temperature, but is not sensitive to iodide inlet concentration. When solution flow rate is low, the absorption efficiency increases rapidly with increasing the solution flow rate, and when the solution is excessive, the absorption efficiency remains around 99% stably; the influence of gas flow rate on absorption efficiency is mainly reflected in the variation of gas and liquid contacting time; when the solution flow rate is low, the increase of gas flow rate will led to an obvious decrease in absorption efficiency; temperature is not important when gas flow rate in constant but becomes effective for improving the absorption efficiency when gas velocity is constant. The proposed mathematical model can predict the iodide absorption process well in the range of experimental conditions. Especially, in the condition of lower gas flow rate and higher solution flow rate, the prediction accuracy is more satisfactory; however the accuracy of prediction will decrease at higher gas flow rates and lower solution flow rates because of neglecting the transverse exchange between gas and liquid phase.

  19. NRC performance indicator program

    International Nuclear Information System (INIS)

    Singh, R.N.

    1987-01-01

    The performance indicator development work of the US Nuclear Regulatory Commission (NRC) interoffice task group involved several major activities that included selection of candidate indicators for a trial program, data collection and review, validation of the trial indicators, display method development, interactions with the industry, and selection of an optimum set of indicators for the program. After evaluating 27 potential indicators against certain ideal attributes, the task group selected 17 for the trial program. The pertinent data for these indicators were then collected from 50 plants at 30 sites. The validation of the indicators consisted of two primary processes: logical validity and statistical analysis. The six indicators currently in the program are scrams, safety system actuations, significant events, safety system failures, forced outage rate, and equipment forced outages per 100 critical hours. A report containing data on the six performance indicators and some supplemental information is issued on a quarterly basis. The NRC staff is also working on refinements of existing indicators and development of additional indicators as directed by the commission

  20. MRI features of chondroblastoma

    International Nuclear Information System (INIS)

    Cheng Xiaoguang; Liu Xia; Cheng Kebin; Liu Wei

    2009-01-01

    Objective: To evaluate the MR imaging features of chondroblastoma. Methods: MRI examinations of 20 patients with histological proven chondmblastoma were reviewed retrospectively. The MRI findings of chondroblastoma including the signal intensity, the shape, the growth patterns, and the surrounding bone marrow edema and the adjacent soft tissue edema, the periosteal reaction, the adjacent joint effusion were analyzed. Results: All 20 cases demonstrated heterogeneous MR signal intensity on T 1 WI and T 2 WI images and showed lobular margins. Sixteen cases demonstrated expansive growth patterns. Surrounding bone marrow edema was found in 18 cases and adjacent soft tissue edema in 14 cases. Periosteal reaction was identified in 6 cases. In 7 cases the tumor extended to adjacent soft tissue. Adjacent joint effusion was visible on MRI in 6 cases. Conclusion: Heterogeneous signal intensity, lobular margins and expansive growth pattern, adjacent bone marrow and soft tissue edema were the common features of chondroblastoma on MRI. (authors)

  1. Model Checking Feature Interactions

    DEFF Research Database (Denmark)

    Le Guilly, Thibaut; Olsen, Petur; Pedersen, Thomas

    2015-01-01

    This paper presents an offline approach to analyzing feature interactions in embedded systems. The approach consists of a systematic process to gather the necessary information about system components and their models. The model is first specified in terms of predicates, before being refined to t...... to timed automata. The consistency of the model is verified at different development stages, and the correct linkage between the predicates and their semantic model is checked. The approach is illustrated on a use case from home automation....

  2. Special Features of the Optical Absorption and Photoconductivity of Indium Monoselenide Upon Laser Excitation

    Science.gov (United States)

    Kyazym-Zade, A. G.; Salmanov, V. M.; Guseinov, A. G.; Mamedov, R. M.; Salmanova, A. A.; Akhmedova, F. Sh.

    2018-02-01

    The successive ionic layer adsorption and reaction (SILAR) method is used to prepare InSe thin films and InSe nanoparticles. Shapes and sizes of the obtained nanoparticles are investigated using a scanning electron microscope and an atomic force microscope. The main parameters of the examined structures, nanoparticle sizes (4-20 nm), and band gap ( E g = 1.60 eV) for nanoparticles with the least sizes are determined. Superfast (1.5·10-8 s) photocurrent relaxation and stimulated emission with line half-width of 8 Å have been observed upon exposure to laser radiation.

  3. Fitting peculiar spectral profiles in He I 10830 angstrom absorption features

    Czech Academy of Sciences Publication Activity Database

    Gonzalez Manrique, S. J.; Kuckein, C.; Pastor Yabar, A.; Collados Vera, M.; Denker, C.; Fischer, C.E.; Gömöry, P.; Diercke, A.; Gonzalez, N.B.; Schlichenmaier, R.; Balthasar, H.; Berkefeld, T.; Feller, A.; Hoch, S.; Hofmann, A.; Kneer, F.; Nicklas, H.; Orozco Suárez, D.; Schmidt, D.; Schmidt, W.; Sigwarth, M.; Sobotka, Michal; Solanki, S.K.; Soltau, D.; Staude, J.; Strassmeier, K.G.; Verma, M.; Volkmer, R.; von der Lühe, O.; Waldmann, T.A.

    2016-01-01

    Roč. 337, č. 10 (2016), s. 1057-1063 ISSN 0004-6337. [Dynamic Sun - Exploring the Many Facets of Solar Eruptive Events. Potsdam, 26.10.2015-29.10.2015] Institutional support: RVO:67985815 Keywords : Sun * chromosphere * data analysis Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.916, year: 2016

  4. A spectroscopic study of absorption and emission features of interstellar dust components

    International Nuclear Information System (INIS)

    Zwet, G.P. van der.

    1986-01-01

    The spectroscopic properties of silicate interstellar dust grains are the subject of this thesis. The process of accretion and photolysis is simulated in the laboratory by condensing mixtures of gases onto a cold substrate (T ∼ 12 K) in a vacuum chamber and photolyzing these mixtures with a vacuum ultraviolet source. Alternatively, the gas mixtures may be passed through a microwave discharge first, before deposition. The spectroscopic properties of the ices are investigated using ultraviolet, visible and infrared spectroscopy. (Auth.)

  5. National Climate Assessment Indicators: Background, Development, & Examples

    Energy Technology Data Exchange (ETDEWEB)

    Janetos, Anthony C.; Chen, Robert; Arndt, Deke; Kenney, Melissa A.; Abbasi, Daniel; Armstrong, Tom; Bartuska, Ann; Blair, Maria; Buizer, Jim; Dietz, Tom; Easterling, Dave; Kaye, Jack; Kolian, Michael; McGeehin, Michael; O' Connor, Robert; Pulwarty, Roger; Running, Steve; Schmalensee, Dick; Webb, Robert; Weltzin, Jake; Baptista, Sandra; Enquist, Carolyn A.; Janetos, Anthony C.; Chen, Robert; Arndt, Deke; Hatfield, Jerry; Hayes, Mark L.; Jones, K. Burce; McNutt, Chad; Meier, Wayne R.; Schwartz, Mark D.; Svoboda, Mark

    2012-02-28

    Indicators are usually thought of as measurements or calculations that represent important features of the status, trend, or performance of a system of interest (e.g. the economy, agriculture, air quality). They are often used for the most practical of reasons – one cannot measure everything important about systems of interest, so there is a practical need to identify major features that can be reported periodically and used to guide both research and decisions (NRC 2000).

  6. Nonlinear bleaching, absorption, and scattering of 532-nm-irradiated plasmonic nanoparticles

    International Nuclear Information System (INIS)

    Liberman, V.; Sworin, M.; Kingsborough, R. P.; Geurtsen, G. P.; Rothschild, M.

    2013-01-01

    Single-pulse irradiation of Au and Ag suspensions of nanospheres and nanodisks with 532-nm 4-ns pulses has identified complex optical nonlinearities while minimizing material damage. For all materials tested, we observe competition between saturable absorption (SA) and reverse SA (RSA), with RSA behavior dominating for intensities above ∼50 MW/cm 2 . Due to reduced laser damage in single-pulse experiments, the observed intrinsic nonlinear absorption coefficients are the highest reported to date for Au nanoparticles. We find size dependence to the nonlinear absorption enhancement for Au nanoparticles, peaking in magnitude for 80-nm nanospheres and falling off at larger sizes. The nonlinear absorption coefficients for Au and Ag spheres are comparable in magnitude. On the other hand, the nonlinear absorption for Ag disks, when corrected for volume fraction, is several times higher. These trends in nonlinear absorption are correlated to local electric field enhancement through quasi-static mean-field theory. Through variable size aperture measurements, we also separate nonlinear scattering from nonlinear absorption. For all materials tested, we find that nonlinear scattering is highly directional and that its magnitude is comparable to that of nonlinear absorption. These results indicate methods to improve the efficacy of plasmonic nanoparticles as optical limiters in pulsed laser systems.

  7. Gastrointestinal absorption of Np in rats

    International Nuclear Information System (INIS)

    Wirth, R.; Volf, V.

    1985-01-01

    The effect of Np mass and the acidity of the administered Np solutions as well as the age, sex and nutritional status of the animals injected or gavaged with 239Np or 237Np were determined. The latter factor proved to be dominant for absorption of Np from the gut. Thus in fasting weanling and young adult male rats, the absorption of 239Np was sixfold higher (0.18% and 0.12%, respectively) than in fed ones (0.03% and 0.02%, respectively). Absorption by fasted adult females was 0.05% of the administered 239Np, about half of that of adult males. Raising the Np-mass gavaged to fasted female rats to 1 and 10 mg 237Np/kg resulted in an absorption of 0.23% and 0.26%, respectively. Thus, an increased absorption of Np in adult rats seems to be expected only if a large mass is ingested. No dependence of the absorption of Np on nitric acid concentration was found. The data obtained after oral administration of 238Pu and 239Np to adult rats suggest that the f1 factor recommended by the ICRP for fractional absorption of soluble Np compounds from the gut should be decreased, whereas the f1 factor for soluble Pu compounds should be raised

  8. The effect of volatility on percutaneous absorption.

    Science.gov (United States)

    Rouse, Nicole C; Maibach, Howard I

    2016-01-01

    Topically applied chemicals may volatilize, or evaporate, from skin leaving behind a chemical residue with new percutaneous absorptive capabilities. Understanding volatilization of topical medications, such as sunscreens, fragrances, insect repellants, cosmetics and other commonly applied topicals may have implications for their safety and efficacy. A systematic review of English language articles from 1979 to 2014 was performed using key search terms. Articles were evaluated to assess the relationship between volatility and percutaneous absorption. A total of 12 articles were selected and reviewed. Key findings were that absorption is enhanced when coupled with a volatile substance, occlusion prevents evaporation and increases absorption, high ventilation increases volatilization and reduces absorption, and pH of skin has an affect on a chemical's volatility. The articles also brought to light that different methods may have an affect on volatility: different body regions; in vivo vs. in vitro; human vs. Data suggest that volatility is crucial for determining safety and efficacy of cutaneous exposures and therapies. Few articles have been documented reporting evaporation in the context of percutaneous absorption, and of those published, great variability exists in methods. Further investigation of volatility is needed to properly evaluate its role in percutaneous absorption.

  9. Giordano Bruno crater on the Moon: Detection and Mapping of Hydration Features of Endogenic and/or Exogenic Nature

    Science.gov (United States)

    Saran Bhiravarasu, Sriram; Bhattacharya, Satadru; Chauhan, Prakash

    2017-10-01

    We analyze high resolution spectral and spatial data from the recent lunar missions and report the presence of strong hydration features within the inner flank, hummocky floor, ejecta and impact melt deposits of crater Giordano Bruno. Hydroxyl-bearing lithologies at Giordano Bruno are characterized primarily by a prominent absorption feature near 2800 nm, the band minima of which goes beyond 3000 nm. The hydration features are found to be associated with low-Ca pyroxene-bearing noritic lithologies along the inner crater flanks, whereas similar features are also seen within the hummocky crater floor in association with shocked plagioclase-bearing anorthositic lithology. Interestingly, the ejecta blanket is characterized by sharp, narrow features centered near 2800 nm similar to the features previously reported from Compton-Belkovich volcanic complex and central peak of crater Theophilus. The low-Ca pyroxene-bearing rock exposures within the crater inner flanks are characterized by both presence and absence of the hydration features. Enhanced hydration is also seen within the ejecta blanket covering the nearby Harkhebi K and J craters. We also analyze the impact melts and ejecta using radar images at regions interior and exterior to the Giordano Bruno crater rim.Anomalous behaviors of hydration feature associated with low-Ca pyroxene-rich exposures, its nature and occurrences within the impact melt sheets inside the crater along with the ejecta blankets could possibly indicate endogenic and/or exogenic nature of the observed hydration feature. Initial results indicate the presence of strongest hydration feature in the partially shadowed pole-facing slopes (with low-Ca pyroxene-bearing exposures) and its complete absence in the equator-facing sun-lit slopes. This hints at a possible exogenic origin, whereas the same feature occurring (with same mineral) under both sun-lit and shadowed conditions suggest it to be of magmatic origin. We propose that the heterogeneous

  10. Glucose absorption in acute peritoneal dialysis.

    Science.gov (United States)

    Podel, J; Hodelin-Wetzel, R; Saha, D C; Burns, G

    2000-04-01

    During acute peritoneal dialysis (APD), it is known that glucose found in the dialysate solution contributes to the provision of significant calories. It has been well documented in continuous ambulatory peritoneal dialysis (CAPD) that glucose absorption occurs. In APD, however, it remains unclear how much glucose absorption actually does occur. Therefore, the purpose of this study was to determine whether it is appropriate to use the formula used to calculate glucose absorption in CAPD (Grodstein et al) among patients undergoing APD. Actual measurements of glucose absorption (Method I) were calculated in 9 patients undergoing APD treatment for >24 hours who were admitted to the intensive care unit. Glucose absorption using the Grodstein et al formula (Method II) was also determined and compared with the results of actual measurements. The data was then further analyzed based on the factors that influence glucose absorption, specifically dwell time and concentration. The mean total amount of glucose absorbed was 43% +/- 15%. However, when dwell time and concentration were further examined, significant differences were noted. Method I showed a cumulative increase over time. Method II showed that absorption was fixed. This suggests that with the variation in dwell time commonly seen in the acute care setting, the use of Method II may not be accurate. In each of the 2 methods, a significant difference in glucose absorption was noted when comparing the use of 1.5% and 4.25% dialysate concentrations. The established formula designed for CAPD should not be used for calculating glucose absorption in patients receiving APD because variation in dwell time and concentration should be taken into account. Because of the time constraints and staffing required to calculate each exchange individually, combined with the results of the study, we recommend the use of the percentage estimate of 40% to 50%.

  11. eHealth indicators

    DEFF Research Database (Denmark)

    HYPPÖNEN, Hannele; AMMENWERTH, Elske; Nøhr, Christian

    2012-01-01

    eHealth indicators are needed to measure defined aspects of national eHealth implementations. However, until now, eHealth indicators are ambiguous or unclear. Therefore, an expert workshop "Towards an International Minimum Dataset for Monitoring National Health Information System Implementations......" was organized. The objective was to develop ideas for a minimum eHealth indicator set. The proposed ideas for indicators were classified based on EUnetHTA and De-Lone & McClean, and classification was compared with health IT evaluation criteria classification by Ammenwerth & Keizer. Analysis of the workshop...... results emphasized the need for a common methodological framework for defining and classifying eHealth indicators. It also showed the importance of setting the indicators into context. The results will benefit policy makers, developers and researchers in pursuit of provision and use of evidence...

  12. Float level indicator

    International Nuclear Information System (INIS)

    Grishchuk, M.Kh.; Laptev, A.G.; Pashkov, V.A.

    1980-01-01

    Specially developed level indicator is suggested with differential to-transformer converter of the float motion, operating in line with a movable electronic block, intended for indicating the level of the dissociating nitrogen tetroxide liquid phase. On the basis of the indicator elements the device is realized to measure the time of calibrated volume fillino. in by liquid nitrogen tetroxide in steady state operation of the experimental bench-marks [ru

  13. Effect of oils on drug absorption

    OpenAIRE

    Palin, K.J.

    1981-01-01

    Oil and emulsion vehicles have been shown to alter the oral absorption of many drugs. This may be due to enhanced lymph flow and/or altered gastro-intestinal motility in the presence of the oils. The oral absorption of a model compound (DOT) in the presence of three chemically different oils, arachis oil, Miglyol 812 and liquid paraffin was investigated in rats, the influence of lymphatic absorption and gastro-intestinal motility being determined. The findings were applied to the for.mulation...

  14. Absorption spectrum of Iodine around 5915 A

    International Nuclear Information System (INIS)

    1990-01-01

    The iodine absorption spectrum around 5915 A is of interest for many authors especially the hyperfine structure of the iodine line. Lodine absorption spectrum was obtained due to the interaction of iodine vapour with dye laser [(R6G) (0.5A) scanning range around 5915 A] which is pumped by(Ar + )laser absorption spectrum. The decrease in the peak of the transmission line around 5915 A shows the signal futher decreased by heating the iodine cell. This analysis has been done using a monochromator

  15. Absorption of proteins and amino acids

    International Nuclear Information System (INIS)

    Jeejeebhoy, K.N.

    1976-01-01

    Although the absorption of proteins and amino acids is an important issue in nutrition, its measurement is not common because of the methodological difficulties. Complications are attributable in particular to the magnitude of endogenous protein secretion and to the diversity of absorption mechanisms for amino acids either as individual units or as peptides. Methods for studying absorption include balance techniques, tolerance tests, tracer techniques using proteins or amino acids labelled with 131 I, 3 H, or 15 N, intestinal perfusion studies, and others; they must be selected according to the nature of the information sought. Improvements over the current methods would be useful. (author)

  16. Evidence for pion absorption on four nucleons

    International Nuclear Information System (INIS)

    Rzehorz, B.; Backenstoss, G.; Dzemidzic, M.; Zagreb Univ.; Furic, M.; Zagreb Univ.; Hoffart, A.; Petkovic, T.; Zagreb Univ.; Ullrich, H.; Weyer, H.J.; Weiser, D.; Wildi, M.

    1996-01-01

    Experimental spectra from the coincident detection of three nucleons after the pion absorption in 4 He are displayed. The presence of a mechanism with four nucleons participating in the absorption process is made obvious. The total cross-sections for this absorption mode are: σ 4NA abs =(1.0±0.2)mb at T π =120 MeV and σ 4NA abs =(2.18± 0.65) mb at T π =210 MeV. (orig.)

  17. Gastrointestinal absorption of uranium in man

    International Nuclear Information System (INIS)

    Larsen, R.P.; Orlandini, K.A.

    1984-01-01

    A method has been established for determining the fractional absorption of uranium directly in man. Measurements are made of the urinary excretion rates of uranium for individuals whose drinking water has a high 234 U to 238 U activity ratio and is the primary source of 234 U in their diets. For two individuals, the values obtained for the fractional absorption of 234 U were 0.004 and 0.006. The values obtained for the fractional absorption of 238 U, using a literature value for the 238 U intake from food, were 0.008 and 0.015. The present ICRP value is 0.20. 7 references, 1 table

  18. Optical absorption in a thin nickel wire

    OpenAIRE

    INAGAKI, Takashi; Goudonnet, J.P.; ARAKAWA, E.T.

    1986-01-01

    Absorption of a 633-nm phonton in a cylindrical nickel wire with diameter 13 m was measured by a photoacoustic method as a function of angle of phonton incidence . A good photoacoustic signal was obtained with a 6-m W He-Ne laser as a light source without employing focusing optics. The absorption measured for p-polarized phontons was found to be in good agreement with geometrical optics calculation. For s-polarized light, however, significant excess absorption was found for >35.

  19. Optical absorption in a thin nickel wire

    International Nuclear Information System (INIS)

    Inagaki, T.; Goudonnet, J.P.; Arakawa, E.T.

    1986-01-01

    Absorption of a 633-nm photon in a cylindrical nickel wire with diameter 13 μm was measured by a photoacoustic method as a function of angle of photon incidence theta. A good photoacoustic signal was obtained with a 6-mW He-Ne laser as a light source without employing focusing optics. The absorption measured for p-polarized photons was found to be in good agreement with geometrical optics calculation. For s-polarized light, however, significant excess absorption was found for theta > 35 0

  20. Total absorption by degenerate critical coupling

    Energy Technology Data Exchange (ETDEWEB)

    Piper, Jessica R., E-mail: jrylan@stanford.edu; Liu, Victor; Fan, Shanhui, E-mail: shanhui@stanford.edu [Ginzton Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

    2014-06-23

    We consider a mirror-symmetric resonator with two ports. We show that, when excited from a single port, complete absorption can be achieved through critical coupling to degenerate resonances with opposite symmetry. Moreover, any time two resonances with opposite symmetry are degenerate in frequency and absorption is always significantly enhanced. In contrast, when two resonances with the same symmetry are nearly degenerate, there is no absorption enhancement. We numerically demonstrate these effects using a graphene monolayer on top of a photonic crystal slab, illuminated from a single side in the near-infrared.

  1. Gas treating absorption theory and practice

    CERN Document Server

    Eimer, Dag

    2014-01-01

    Gas Treating: Absorption Theory and Practice provides an introduction to the treatment of natural gas, synthesis gas and flue gas, addressing why it is necessary and the challenges involved.  The book concentrates in particular on the absorption-desorption process and mass transfer coupled with chemical reaction. Following a general introduction to gas treatment, the chemistry of CO2, H2S and amine systems is described, and selected topics from physical chemistry with relevance to gas treating are presented. Thereafter the absorption process is discussed in detail, column hardware is explain

  2. The Driving Forces of Subsidiary Absorptive Capacity

    DEFF Research Database (Denmark)

    Schleimer, Stephanie C.; Pedersen, Torben

    2013-01-01

    The study investigates how a multinational corporation (MNC) can promote the absorptive capacity of its subsidiaries. The focus is on what drives the MNC subsidiary's ability to absorb marketing strategies that are initiated by the MNC parent, as well as how the subsidiary enacts on this absorptive...... as a purposeful response to this dual embeddedness. An analysis of marketing strategy absorptions undertaken by 213 subsidiaries reveals that MNCs can assist their subsidiaries to compete in competitive and dynamic focal markets by forming specific organizational mechanisms that are conducive to the development...

  3. Saturable absorption in detonation nanodiamond dispersions

    Science.gov (United States)

    Vanyukov, Viatcheslav; Mikheev, Gennady; Mogileva, Tatyana; Puzyr, Alexey; Bondar, Vladimir; Lyashenko, Dmitry; Chuvilin, Andrey

    2017-07-01

    We report on a saturable absorption in aqueous dispersions of nanodiamonds with femtosecond laser pulse excitation at a wavelength of 795 nm. The open aperture Z-scan experiments reveal that in a wide range of nanodiamond particle sizes and concentrations, a light-induced increase of transmittance occurs. The transmittance increase originates from the saturation of light absorption and is associated with a light absorption at 1.5 eV by graphite and dimer chains (Pandey dimer chains). The obtained key nonlinear parameters of nanodiamond dispersions are compared with those of graphene and carbon nanotubes, which are widely used for the mode-locking.

  4. Climate Change Indicators

    Science.gov (United States)

    Presents information, charts and graphs showing measured climate changes across 40 indicators related to greenhouse gases, weather and climate, oceans, snow and ice, heath and society, and ecosystems.

  5. VP Ellipsis without Indices

    DEFF Research Database (Denmark)

    Hardt, Daniel; Asher, Nicholas; Hunter, Julie

    2013-01-01

    This paper compares two views on the status of indices in syntactic and logical representations. On a structural view, indices are syntactic formants on a par with node labels and phrase bracketings, and are thus a part of the logical forms that are derived from syntactic representations. On the ......This paper compares two views on the status of indices in syntactic and logical representations. On a structural view, indices are syntactic formants on a par with node labels and phrase bracketings, and are thus a part of the logical forms that are derived from syntactic representations...

  6. Analysis of Decentralized Control for Absorption Cycle Heat Pumps

    DEFF Research Database (Denmark)

    Vinther, Kasper; Just Nielsen, Rene; Nielsen, Kirsten Mølgaard

    2015-01-01

    Email Print Request Permissions This paper investigates decentralized control structures for absorption cycle heat pumps and a dynamic nonlinear model of a single-effect LiBr-water absorption system is used as case study. The model has four controllable inputs, which can be used to stabilize...... the operation of the heat pump under different load conditions. Different feasible input-output pairings are analyzed by computation of relative gain array matrices and scaled condition numbers, which indicate the best pairing choice and the potential of each input-output set. Further, it is possible...... to minimize the effect of cross couplings and improve stability with the right pairing of input and output. Simulation of selected candidate input-output pairings demonstrate that decentralized control can provide stable operation of the heat pump....

  7. Brownian rotational relaxation and power absorption in magnetite nanoparticles

    International Nuclear Information System (INIS)

    Goya, G.F.; Fernandez-Pacheco, R.; Arruebo, M.; Cassinelli, N.; Ibarra, M.R.

    2007-01-01

    We present a study of the power absorption efficiency in several magnetite-based colloids, to asses their potential as magnetic inductive hyperthermia (MIH) agents. Relaxation times τ were measured through the imaginary susceptibility component χ ' '(T), and analyzed within Debye's theory of dipolar fluid. The results indicated Brownian rotational relaxation and allowed to calculate the hydrodynamic radius close to the values obtained from photon correlation. The study of the colloid performances as power absorbers showed no detectable increase of temperature for dextran-coated Fe 3 O 4 nanoparticles, whereas a second Fe 3 O 4 -based dispersion of similar concentration could be heated up to 12K after 30min under similar experimental conditions. The different power absorption efficiencies are discussed in terms of the magnetic structure of the nanoparticles

  8. Brownian rotational relaxation and power absorption in magnetite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Goya, G.F. [Institute of Nanoscience of Aragon (INA), University of Zaragoza, 50009 Zaragoza (Spain)]. E-mail: goya@unizar.es; Fernandez-Pacheco, R. [Institute of Nanoscience of Aragon (INA), University of Zaragoza, 50009 Zaragoza (Spain); Arruebo, M. [Institute of Nanoscience of Aragon (INA), University of Zaragoza, 50009 Zaragoza (Spain); Cassinelli, N. [Electronics Division, Bauer and Associates, Buenos Aires (Argentina); Facultad de Ingenieria, UNLP (Argentina); Ibarra, M.R. [Institute of Nanoscience of Aragon (INA), University of Zaragoza, 50009 Zaragoza (Spain)

    2007-09-15

    We present a study of the power absorption efficiency in several magnetite-based colloids, to asses their potential as magnetic inductive hyperthermia (MIH) agents. Relaxation times {tau} were measured through the imaginary susceptibility component {chi}{sup '}'(T), and analyzed within Debye's theory of dipolar fluid. The results indicated Brownian rotational relaxation and allowed to calculate the hydrodynamic radius close to the values obtained from photon correlation. The study of the colloid performances as power absorbers showed no detectable increase of temperature for dextran-coated Fe{sub 3}O{sub 4} nanoparticles, whereas a second Fe{sub 3}O{sub 4}-based dispersion of similar concentration could be heated up to 12K after 30min under similar experimental conditions. The different power absorption efficiencies are discussed in terms of the magnetic structure of the nanoparticles.

  9. Changes in UV absorption of sunscreens after UV irradiation

    Science.gov (United States)

    Tarras-Wahlberg, N.; Stenhagen, G.; Larkö, O.; Rosén, A.; Wennberg, A.-M.; Wennerström, O.

    2000-03-01

    In the present investigation we have studied the change in the absorption spectrum of some photoactive organic species in sunscreens after UVA and UVB irradiation in a dose normally encountered during a full day in the sun. The absorbance of 2-ethylhexyl 4-methoxycinnamate was reduced significantly, while 3-(4-methylbenzyliden)camphor seemed to be rather stable. The benzophenones studied seemed to be relatively stable. In the case of 4-tert.butyl-4´-methoxy-dibenzoylmethane there was a rapid decrease in the UVA absorption leading to unsatisfactory protection in the UVA region. 4-Isopropyl-dibenzoylmethane also lost most of its UV protective capacity after irradiation with UVA. UVB seemed to have a minor effect on all the samples. The present study including gas chromatography and mass spectrometry analysis indicates that some of the photoactive organic species commonly used today in sunscreens are unstable following UV irradiation.

  10. Spectroscopic study of low-temperature hydrogen absorption in palladium

    Energy Technology Data Exchange (ETDEWEB)

    Ienaga, K., E-mail: ienaga@issp.u-tokyo.ac.jp; Takata, H.; Onishi, Y.; Inagaki, Y.; Kawae, T. [Department of Applied Quantum Physics, Faculty of Engineering, Kyushu University, Motooka, Nishi-Ku, Fukuoka 819-0395 (Japan); Tsujii, H. [Department of Physics, Faculty of Education, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Kimura, T. [Department of Physics, Kyushu University, Hakozaki, Higashi-Ku, Fukuoka 812-8581 (Japan)

    2015-01-12

    We report real-time detection of hydrogen (H) absorption in metallic palladium (Pd) nano-contacts immersed in liquid H{sub 2} using inelastic electron spectroscopy (IES). After introduction of liquid H{sub 2}, the spectra exhibit the time evolution from the pure Pd to the Pd hydride, indicating that H atoms are absorbed in Pd nano-contacts even at the temperature where the thermal process is not expected. The IES time and bias voltage dependences show that H absorption develops by applying bias voltage 30 ∼ 50 mV, which can be explained by quantum tunneling. The results represent that IES is a powerful method to study the kinetics of high density H on solid surface.

  11. Absorption, transport, and chemical fate of plutonium in soybean plants

    International Nuclear Information System (INIS)

    Garland, T.R.; Cataldo, D.A.; Wildung, R.E.

    1981-01-01

    Absorption of plutonium (Pu) by soybean plants (Glycine max cv. Williams) is limited by Pu solubility in soils. Changes in Pu concentration in different tissues with time to senescence indicate Pu is freely transported through the xylem during growth but not subject to remobilization on flowering. Studies in which the DTPA complex of 238 Pu was supplied to the plant suggest a change in chemical form following root absorption. Of the Pu in roots, stems, and leaves at senescence, 28, 54, and 67%, respectively, were soluble. The Pu in the solluble fraction was primarily associated with components of >10000 equivalent molecular weight in leaves and roots, whereas stems exhibited an equal distribution between components in the >10000 and <500 molecular weight fractions. Plutonium associated with mature seeds is concentrated in the seed hull (85%) and cotyledons (14%). The Pu associated with the cotyledon was primarily in the insoluble residues and soluble soy whey

  12. Solar hybrid cooling system for high-tech offices in subtropical climate - Radiant cooling by absorption refrigeration and desiccant dehumidification

    International Nuclear Information System (INIS)

    Fong, K.F.; Chow, T.T.; Lee, C.K.; Lin, Z.; Chan, L.S.

    2011-01-01

    Highlights: → A solar hybrid cooling system is proposed for high-tech offices in subtropical climate. → An integration of radiant cooling, absorption refrigeration and desiccant dehumidification. → Year-round cooling and energy performances were evaluated through dynamic simulation. → Its annual primary energy consumption was lower than conventional system up to 36.5%. → The passive chilled beams were more energy-efficient than the active chilled beams. - Abstract: A solar hybrid cooling design is proposed for high cooling load demand in hot and humid climate. For the typical building cooling load, the system can handle the zone cooling load (mainly sensible) by radiant cooling with the chilled water from absorption refrigeration, while the ventilation load (largely latent) by desiccant dehumidification. This hybrid system utilizes solar energy for driving the absorption chiller and regenerating the desiccant wheel. Since a high chilled water temperature generated from the absorption chiller is not effective to handle the required latent load, desiccant dehumidification is therefore involved. It is an integration of radiant cooling, absorption refrigeration and desiccant dehumidification, which are powered up by solar energy. In this study, the application potential of the solar hybrid cooling system was evaluated for the high-tech offices in the subtropical climate through dynamic simulation. The high-tech offices are featured with relatively high internal sensible heat gains due to the intensive office electric equipment. The key performance indicators included the solar fraction and the primary energy consumption. Comparative study was also carried out for the solar hybrid cooling system using two common types of chilled ceilings, the passive chilled beams and active chilled beams. It was found that the solar hybrid cooling system was technically feasible for the applications of relatively higher cooling load demand. The annual primary energy

  13. Infrared absorption of CH3OSO detected with time-resolved Fourier-transform spectroscopy.

    Science.gov (United States)

    Chen, Jin-Dah; Lee, Yuan-Pern

    2011-03-07

    A step-scan Fourier-transform spectrometer coupled with a multipass absorption cell was employed to detect temporally resolved infrared absorption spectra of CH(3)OSO produced upon irradiation of a flowing gaseous mixture of CH(3)OS(O)Cl in N(2) or CO(2) at 248 nm. Two intense transient features with origins near 1152 and 994 cm(-1) are assigned to syn-CH(3)OSO; the former is attributed to overlapping bands at 1154 ± 3 and 1151 ± 3 cm(-1), assigned to the S=O stretching mixed with CH(3) rocking (ν(8)) and the S=O stretching mixed with CH(3) wagging (ν(9)) modes, respectively, and the latter to the C-O stretching (ν(10)) mode at 994 ± 6 cm(-1). Two weak bands at 2991 ± 6 and 2956 ± 3 cm(-1) are assigned as the CH(3) antisymmetric stretching (ν(2)) and symmetric stretching (ν(3)) modes, respectively. Observed vibrational transition wavenumbers agree satisfactorily with those predicted with quantum-chemical calculations at level B3P86∕aug-cc-pVTZ. Based on rotational parameters predicted at that level, the simulated rotational contours of these bands agree satisfactorily with experimental results. The simulation indicates that the S=O stretching mode of anti-CH(3)OSO near 1164 cm(-1) likely makes a small contribution to the observed band near 1152 cm(-1). A simple kinetic model of self-reaction is employed to account for the decay of CH(3)OSO and yields a second-order rate coefficient k=(4 ± 2)×10(-10) cm(3)molecule(-1)s(-1). © 2011 American Institute of Physics.

  14. Experimental determination of the absorption rate of unattached radon progeny from respiratory tract to blood

    International Nuclear Information System (INIS)

    Butterweck, G.; Schuler, Ch.; Vessl, G.; Mueller, R.; Marsh, J.W.; Thrift, S.; Birchall, A.

    2002-01-01

    An exposure methodology was developed for the determination of the absorption rate of unattached radon progeny deposited in the human respiratory tract to blood. Twenty-one volunteers were exposed in a radon chamber during well-controlled aerosol and radon progeny conditions, with predominantly unattached radon daughters. Special efforts were made to restrict the dose to the volunteers to an absolute maximum of 0.08 mSv. Measurements of radon gas and radon progeny in blood samples of these volunteers indicated absorption half times of 20 min to 60 min. Former determinations, mainly performed with much larger aerosol particles of diameters between 100 nm and 1000 nm, implied absorption half times around 10 h. This indicates that the absorption of radon decay products from ciliated airways into blood is dependent upon particle size and particle composition. (author)

  15. The absorption and transportation of ferric-salt in apple trees

    International Nuclear Information System (INIS)

    Xiong Zhixun; Chen Meihong

    1994-01-01

    59 Fe tracer technique was used to study the ferric-salt absorption, utilization and transportation in apple trees. The results indicated that absorption and utilization rate of ferric salt was 0.056%∼0.110% for roots and 30% for leaves, and that Fe is not easily to be transferred from one part to another. Fulvic acid iron had a better effect than ferrous sulfate. Ferric-salt absorption, utilization and transference were different among the cultivars. Intensive injections of ferrous salt into the apple trunks seemed to be more effective for correcting of chlorosis

  16. A structural study of bone changes in knee osteoarthritis by synchrotron-based X-ray fluorescence and X-ray absorption spectroscopy techniques

    Science.gov (United States)

    Sindhupakorn, Bura; Thienpratharn, Suwittaya; Kidkhunthod, Pinit

    2017-10-01

    Osteoarthritis (OA) is characterized by degeneration of articular cartilage and thickening of subchondral bone. The present study investigated the changing of biochemical components of cartilage and bone compared between normal and OA people. Using Synchrotron-based X-ray fluorescence (SR-XRF) and X-ray absorption spectroscopy (XAS) techniquesincluding X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) were employed for the bone changes in kneeosteoarthritisstudies. The bone samples were collected from various osteoarthritis patients with both male and female in the ages range between 20 and 74 years old. SR-XRF results excited at 4240 eV for Ca elements show a majority three main groups, based on their XRF intensities, 20-36 years, 40-60 years and over 70 years, respectively. By employing XAS techniques, XANES features can be used to clearly explain in term of electronic transitions occurring in bone samples which are affected from osteoarthritis symptoms. Moreover, a structural change around Ca ions in bone samples is obviously obtained by EXAFS results indicating an increase of Ca-amorphous phase when the ages increase.

  17. Features of MCNP6

    International Nuclear Information System (INIS)

    Goorley, T.; James, M.; Booth, T.; Brown, F.; Bull, J.; Cox, L.J.; Durkee, J.; Elson, J.; Fensin, M.; Forster, R.A.; Hendricks, J.; Hughes, H.G.; Johns, R.; Kiedrowski, B.; Martz, R.; Mashnik, S.; McKinney, G.; Pelowitz, D.; Prael, R.; Sweezy, J.

    2016-01-01

    Highlights: • MCNP6 is simply and accurately described as the merger of MCNP5 and MCNPX capabilities, but it is much more than the sum of these two computer codes. • MCNP6 is the result of six years of effort by the MCNP5 and MCNPX code development teams. • These groups of people, residing in Los Alamos National Laboratory’s X Computational Physics Division, Monte Carlo Codes Group (XCP-3) and Nuclear Engineering and Nonproliferation Division, Radiation Transport Modeling Team (NEN-5) respectively, have combined their code development efforts to produce the next evolution of MCNP. • While maintenance and major bug fixes will continue for MCNP5 1.60 and MCNPX 2.7.0 for upcoming years, new code development capabilities only will be developed and released in MCNP6. • In fact, the initial release of MCNP6 contains numerous new features not previously found in either code. • These new features are summarized in this document. • Packaged with MCNP6 is also the new production release of the ENDF/B-VII.1 nuclear data files usable by MCNP. • The high quality of the overall merged code, usefulness of these new features, along with the desire in the user community to start using the merged code, have led us to make the first MCNP6 production release: MCNP6 version 1. • High confidence in the MCNP6 code is based on its performance with the verification and validation test suites, comparisons to its predecessor codes, our automated nightly software debugger tests, the underlying high quality nuclear and atomic databases, and significant testing by many beta testers. - Abstract: MCNP6 can be described as the merger of MCNP5 and MCNPX capabilities, but it is much more than the sum of these two computer codes. MCNP6 is the result of six years of effort by the MCNP5 and MCNPX code development teams. These groups of people, residing in Los Alamos National Laboratory’s X Computational Physics Division, Monte Carlo Codes Group (XCP-3) and Nuclear Engineering and

  18. Fluorescence detection of white-beam X-ray absorption anisotropy: towards element-sensitive projections of local atomic structure

    International Nuclear Information System (INIS)

    Korecki, P.; Tolkiehn, M.; Dąbrowski, K. M.; Novikov, D. V.

    2011-01-01

    A method for a direct measurement of X-ray projections of the atomic structure is described. Projections of the atomic structure around Nb atoms in a LiNbO 3 single crystal were obtained from a white-beam X-ray absorption anisotropy pattern detected using Nb K fluorescence. Projections of the atomic structure around Nb atoms in a LiNbO 3 single crystal were obtained from a white-beam X-ray absorption anisotropy (XAA) pattern detected using Nb K fluorescence. This kind of anisotropy results from the interference of X-rays inside a sample and, owing to the short coherence length of a white beam, is visible only at small angles around interatomic directions. Consequently, the main features of the recorded XAA corresponded to distorted real-space projections of dense-packed atomic planes and atomic rows. A quantitative analysis of XAA was carried out using a wavelet transform and allowed well resolved projections of Nb atoms to be obtained up to distances of 10 Å. The signal of nearest O atoms was detected indirectly by a comparison with model calculations. The measurement of white-beam XAA using characteristic radiation indicates the possibility of obtaining element-sensitive projections of the local atomic structure in more complex samples

  19. Spectral slopes of the absorption coefficient of colored dissolved and detrital material inverted from UV-visible remote sensing reflectance.

    Science.gov (United States)

    Wei, Jianwei; Lee, Zhongping; Ondrusek, Michael; Mannino, Antonio; Tzortziou, Maria; Armstrong, Roy

    2016-03-01

    The spectral slope of the absorption coefficient of colored dissolved and detrital material (CDM), S cdm (units: nm -1 ), is an important optical parameter for characterizing the absorption spectral shape of CDM. Although highly variable in natural waters, in most remote sensing algorithms, this slope is either kept as a constant or empirically modeled with multiband ocean color in the visible domain. In this study, we explore the potential of semianalytically retrieving S cdm with added ocean color information in the ultraviolet (UV) range between 360 and 400 nm. Unique features of hyperspectral remote sensing reflectance in the UV-visible wavelengths (360-500 nm) have been observed in various waters across a range of coastal and open ocean environments. Our data and analyses indicate that ocean color in the UV domain is particularly sensitive to the variation of the CDM spectral slope. Here, we used a synthesized data set to show that adding UV wavelengths to the ocean color measurements will improve the retrieval of S cdm from remote sensing reflectance considerably, while the spectral band settings of past and current satellite ocean color sensors cannot fully account for the spectral variation of remote sensing reflectance. Results of this effort support the concept to include UV wavelengths in the next generation of satellite ocean color sensors.

  20. Testing the diagnosis of dissociative identity disorder through measures of dissociation, absorption, hypnotizability and PTSD: a Norwegian pilot study.

    Science.gov (United States)

    Dale, Karl Yngvar; Berg, Renate; Elden, Ake; Ødegård, Atle; Holte, Arne

    2009-01-01

    A total of 14 women meeting criteria for dissociative identity disorder (DID) based on the Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]) were compared to a group of women (n = 10) with other dissociative diagnoses and a group of normal controls (n = 14) with regard to dissociativity, absorption, trauma related symptoms and hypnotizability. Both of the clinical groups reported histories of childhood trauma and attained high PTSD scores. The DID group differed significantly from the group with other dissociative diagnoses and the non-diagnosed comparison group with regard to hypnotizability, the variety of dissociative symptomatology, and the magnitude of dissociative symptomatology. However, no significant differences between the two clinical groups were detected with regard to absorption, general dissociative level, or symptoms related to traumatic stress. Results support the notion that DID can be regarded as a clinical entity which is separable from other dissociative disorders. Results also indicated that hypnotizability is the most important clinical feature of DID.

  1. Experimental Determination of the Molar Absorption Coefficient of n-Hexane Adsorbed on High-Silica Zeolites.

    Science.gov (United States)

    Gatti, Giorgio; Olivas Olivera, Diana F; Sacchetto, Vittoria; Cossi, Maurizio; Braschi, Ilaria; Marchese, Leonardo; Bisio, Chiara

    2017-09-06

    Determination of the molar absorption coefficients of the CH 3 bending mode at ν˜ =1380 cm -1 (ϵ 1380 ) of n-hexane adsorbed from the gas phase on two different dealuminated zeolites is derived by a combination of IR spectroscopy and microgravimetric analysis. High-silica zeolite Y (HSZ-Y) and zeolite ZSM-5 (with SiO 2 /Al 2 O 3 ratios of 200 and 280, respectively) with different textural and surface features are selected to evaluate the effect of the pore structure and architecture on the value of ϵ 1380 of the adsorbed n-hexane. Experimental data indicate that the molecule experiences a different adsorption environment inside zeolites; thus resulting in a significant change of the dipole moment and very different ϵ 1380 values: (0.278±0.018) cm μmol -1 for HSZ-Y and (0.491±0.032) cm μmol -1 for ZSM-5. Experimental data are also supported by computational modeling, which confirms the effect of different matrices on the IR absorption intensity. This study reveals that the use of probe molecules for quantitative measurements of surface sites has to be judiciously adopted, especially if adsorption occurs in the restricted spaces of microporous materials. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Pulmonary vasculitis: imaging features

    International Nuclear Information System (INIS)

    Seo, Joon Beom; Im, Jung Gi; Chung, Jin Wook; Goo, Jin Mo; Park, Jae Hyung; Yeon, Kyung Mo; Song, Jae Woo

    1999-01-01

    Vasculitis is defined as an inflammatory process involving blood vessels, and can lead to destruction of the vascular wall and ischemic damage to the organs supplied by these vessels. The lung is commonly affected. A number of attempts have been made to classify and organize pulmonary vasculitis, but because the clinical manifestations and pathologic features of the condition overlap considerably, these afforts have failed to achieve a consensus. We classified pulmonary vasculitis as belonging to either the angitiis-granulomatosis group, the diffuse pulmonary hemorrhage with capillaritis group, or 'other'. Characteristic radiographic and CT findings of the different types of pulmonary vasculitis are illustrated, with a brief discussion of the respective disease entities

  3. Onychomatricoma with misleading features.

    Science.gov (United States)

    Fayol, J; Baran, R; Perrin, C; Labrousse, F

    2000-01-01

    Onychomatricoma is a rare tumour of the nail matrix with peculiar clinical and histological features and electron microscopic findings. We report on 5 cases with appearances which were misleading. Three presented as longitudinal melanonychia, a previously unreported observation. One case had the appearance of a cutaneous horn. In 3 of the 5 cases the tumour was associated with an onychomycosis and this may thus have been a predisposing factor in the secondary fungal infestation. Onychomatricoma appears as a multi-faceted tumour which can be mimicked by longitudinal melanonychia and/or onychomycosis.

  4. Indicators of sustainable tourism

    Directory of Open Access Journals (Sweden)

    Jovičić Dobrica

    2010-01-01

    Full Text Available The indicators, precisely describing the linkages between tourism and the environment, social and cultural base, are not easily available. How ever, some relevant organizations (WTO, EU, OECD, etc., institutions and experts, have been hardly working to create the indicators of sustainable tourism. Whereas the economic objectives are easily defined by the use of the traditional indicators used in national and business economics, it is very difficult to identify widely applicable environmental, social and cultural indicators. In order to stimulate and alleviate the process of sustainable tourism development, EU created the list of comparative indicators of sustainable tourism. In preparing this list, special attention is paid to identification of valid indicators of real tourism impacts on the social and cultural environment (the entire set of traditions, customs, history, hospitality and culture that characterize a given area, that is a very complex task. Assuming the fact that the related indicators have been analyzed in many European countries, this paper is focused on applying the related indicators in research of tourism development in villages of the Kosjerić community. .

  5. Key performance indicators

    NARCIS (Netherlands)

    Zwetsloot, G.I.J.M.

    2014-01-01

    This paper addresses how organisations can use OSH performance indicators. This is an important way to mainstream OSH into business management. Key performance indicators (KPIs) should provide objective data on the OSH situation. It is often said that ‘what gets measured gets managed’. Without

  6. Indicators for environmental sustainability

    DEFF Research Database (Denmark)

    Dong, Yan; Hauschild, Michael Zwicky

    2017-01-01

    . In this study, we reviewed indicators applied in life cycle assessment (LCA), planetary boundary framework (PB), and Sustainable Development Goals (SDGs) developed under United Nation. The aim is to 1) identify their applications and relevant decision context; 2) Review their indicators and categorize them...

  7. M DWARF LUMINOSITY, RADIUS, AND α-ENRICHMENT FROM I-BAND SPECTRAL FEATURES

    Energy Technology Data Exchange (ETDEWEB)

    Terrien, Ryan C.; Mahadevan, Suvrath; Bender, Chad F.; Deshpande, Rohit; Robertson, Paul, E-mail: rct151@psu.edu [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Laboratory, University Park, PA 16802 (United States)

    2015-03-20

    Despite the ubiquity of M dwarfs and their growing importance to studies of exoplanets, Galactic evolution, and stellar structure, methods for precisely measuring their fundamental stellar properties remain elusive. Existing techniques for measuring M dwarf luminosity, mass, radius, or composition are calibrated over a limited range of stellar parameters or require expensive observations. We find a strong correlation between the K{sub S}-band luminosity (M{sub K}), the observed strength of the I-band sodium doublet absorption feature, and [Fe/H] in M dwarfs without strong Hα emission. We show that the strength of this feature, coupled with [Fe/H] and spectral type, can be used to derive M dwarf M{sub K} and radius without requiring parallax. Additionally, we find promising evidence that the strengths of the I-band sodium doublet and the nearby I-band calcium triplet may jointly indicate α-element enrichment. The use of these I-band features requires only moderate-resolution near-infrared spectroscopy to provide valuable information about the potential habitability of exoplanets around M dwarfs, and surface gravity and distance for M dwarfs throughout the Galaxy. This technique has immediate applicability for both target selection and candidate planet–host system characterization for exoplanet missions such as TESS and K2.

  8. M DWARF LUMINOSITY, RADIUS, AND α-ENRICHMENT FROM I-BAND SPECTRAL FEATURES

    International Nuclear Information System (INIS)

    Terrien, Ryan C.; Mahadevan, Suvrath; Bender, Chad F.; Deshpande, Rohit; Robertson, Paul

    2015-01-01

    Despite the ubiquity of M dwarfs and their growing importance to studies of exoplanets, Galactic evolution, and stellar structure, methods for precisely measuring their fundamental stellar properties remain elusive. Existing techniques for measuring M dwarf luminosity, mass, radius, or composition are calibrated over a limited range of stellar parameters or require expensive observations. We find a strong correlation between the K S -band luminosity (M K ), the observed strength of the I-band sodium doublet absorption feature, and [Fe/H] in M dwarfs without strong Hα emission. We show that the strength of this feature, coupled with [Fe/H] and spectral type, can be used to derive M dwarf M K and radius without requiring parallax. Additionally, we find promising evidence that the strengths of the I-band sodium doublet and the nearby I-band calcium triplet may jointly indicate α-element enrichment. The use of these I-band features requires only moderate-resolution near-infrared spectroscopy to provide valuable information about the potential habitability of exoplanets around M dwarfs, and surface gravity and distance for M dwarfs throughout the Galaxy. This technique has immediate applicability for both target selection and candidate planet–host system characterization for exoplanet missions such as TESS and K2

  9. Evaluating Living Standard Indicators

    Directory of Open Access Journals (Sweden)

    Birčiaková Naďa

    2015-09-01

    Full Text Available This paper deals with the evaluation of selected available indicators of living standards, divided into three groups, namely economic, environmental, and social. We have selected six countries of the European Union for analysis: Bulgaria, the Czech Republic, Hungary, Luxembourg, France, and Great Britain. The aim of this paper is to evaluate indicators measuring living standards and suggest the most important factors which should be included in the final measurement. We have tried to determine what factors influence each indicator and what factors affect living standards. We have chosen regression analysis as our main method. From the study of factors, we can deduce their impact on living standards, and thus the value of indicators of living standards. Indicators with a high degree of reliability include the following factors: size and density of population, health care and spending on education. Emissions of carbon dioxide in the atmosphere also have a certain lower degree of reliability.

  10. Gintonin absorption in intestinal model systems

    Directory of Open Access Journals (Sweden)

    Byung-Hwan Lee

    2018-01-01

    Conclusion: The present study shows that gintonin could be absorbed in the intestine through transcellular and paracellular diffusion, and active transport. In addition, the lipid component of gintonin might play a key role in its intestinal absorption.

  11. On pair-absorption in intrinsic vapours

    International Nuclear Information System (INIS)

    Hotop, R.; Niemax, K.; Schlueter, D.

    1982-01-01

    The bound-state pair-absorption bands Cs(6 2 S 1 sub(/) 2 ) + Cs(6 2 S 1 sub(/) 2 ) + hν → Cs(5 2 D 5 sub(/) 2 sub(,) 3 sub(/) 2 ) + Cs(6 2 P 1 sub(/) 2 ) and the K-K continuum-state pair-absorptions in the wavelength region 2.350 <= lambda <= 2.850 Angstroem have been investigated experimentally. In the case of the bound-state pair-absorption bands a theoretical approach for the absorption cross section at the band centre is given which is in good agreement with the experimental observation. Differences between our and the theoretical formulas given by the Stanford group are discussed. (orig.)

  12. evaluation of atomic absorption spectrophotometry (ashing, non ...

    African Journals Online (AJOL)

    cistvr

    1Department of Agricultural and Food Science and 2Department of ... used techniques, namely atomic absorption spectrophotometry (AAS-Ashing and ..... fact that more preparation steps were involved in the Ashing procedure and thus.

  13. Radiant absorption characteristics of corrugated curved tubes

    Directory of Open Access Journals (Sweden)

    Đorđević Milan Lj.

    2017-01-01

    Full Text Available The utilization of modern paraboloidal concentrators for conversion of solar radiation into heat energy requires the development and implementation of compact and efficient heat absorbers. Accurate estimation of geometry influence on absorption characteristics of receiver tubes is an important step in this process. This paper deals with absorption characteristics of heat absorber made of spirally coiled tubes with transverse circular corrugations. Detailed 3-D surface-to-surface Hemicube method was applied to compare radiation performances of corrugated and smooth curved tubes. The numerical results were obtained by varying the tube curvature ratio and incident radiant heat flux intensity. The details of absorption efficiency of corrugated tubes and the effect of curvature on absorption properties for both corrugated and smooth tubes were presented. The results may have significance to further analysis of highly efficient heat absorbers exposed to concentrated radiant heating. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 42006

  14. Enriching Absorptive Capacity Through Social Interaction

    DEFF Research Database (Denmark)

    Hotho, Jasper Jaap; Becker-Ritterspach, Florian; Saka-Helmhout, Ayse

    their organization’s capacity to put new knowledge to use. To address this shortcoming we conduct an in-depth comparative case study of a headquarters-initiated knowledge transfer initiative at two subsidiaries of the same MNE. The findings demonstrate that social interaction is a key requirement for subsidiary....... These insights contribute to the absorptive capacity literature by demonstrating the scale and scope of social interaction as the key link between individual- and organizational-level absorptive capacity.......Absorptive capacity is frequently highlighted as a key determinant of knowledge transfer within MNEs. But how individual behaviour translates to absorptive capacity at the subsidiary level, and exactly how this is contingent on subsidiaries’ social context, remains under-addressed. This not only...

  15. Enriching Absorptive Capacity through Social Interaction

    DEFF Research Database (Denmark)

    Hotho, Jasper J.; Saka-Helmhout, Ayse; Becker-Ritterspach, Florian

    2012-01-01

    their organization's capacity to put new knowledge to use. To address this shortcoming we conduct an in-depth comparative case study of a headquarters-initiated knowledge transfer at two subsidiaries of the same multinational enterprise. The findings demonstrate that social interaction is a prerequisite...... or constraining local interaction patterns. These insights contribute to the absorptive capacity literature by demonstrating the scale and scope of social interaction as a key link between individual- and organizational-level absorptive capacity.......Absorptive capacity is frequently highlighted as a key determinant of knowledge transfer within multinational enterprises. But how individual behaviour translates into absorptive capacity at the subsidiary level, and how this is contingent on subsidiaries' social context, remains under...

  16. Absorption chillers: Part of the solution

    International Nuclear Information System (INIS)

    Occhionero, A.J.; Hughes, P.J.; Reid, E.A.

    1991-01-01

    Acid rain, ozone depletion, global warming, and implementation economics are considered as they relate to the advisability of expanding the application of absorption chillers. Introductory and background information are provided to put the discussion in the proper context. Then all four issues are discussed separately as they relate to absorption chillers. Acid rain and ozone depletion concerns, and implementation economics, are found to support the expanded use of absorption chillers. The global warming concern is found to be more of a gray area, but the areas of benefit correspond well with the conditions of greatest economic advantage. All things considered, absorption chillers are believed to be part of the environmental and economic solution. It is further believed that integrated resource planning (IRP) processes that consider electric and gas technologies on an equal footing would come to the same conclusion for many regions of the United States. 9 refs., 3 tabs

  17. Electromagnetically induced absorption via incoherent collisions

    International Nuclear Information System (INIS)

    Yang Xihua; Sheng Jiteng; Xiao Min

    2011-01-01

    We conduct theoretical studies on electromagnetically induced absorption via incoherent collisions in an inhomogeneously broadened ladder-type three-level system with the density-matrix approach. The effects of the collision-induced coherence decay rates as well as the probe laser field intensity on the probe field absorption are examined. It is shown that with the increase of the collisional decay rates in a moderate range, a narrow dip due to electromagnetically induced transparency superimposed on the Doppler-broadened absorption background can be turned into a narrow peak under the conditions that the probe field intensity is not very weak as compared to the pump field, which results from the enhancement of constructive interference and suppression of destructive interference between one-photon and multiphoton transition pathways. The physical origin of the collision-assisted electromagnetically induced absorption is analyzed with a power-series solution of the density-matrix equations.

  18. (EXAFS) X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    Craievich, A.F.

    1983-01-01

    The technique EXAFS (Extended X-Ray Absorption Fine Structure) is presented and its applications using the synchrotron radiation as an incidente beam in Science of Materials and Biophysics are shown. (L.C.) [pt

  19. Extending Organizational Antecedents Of Absorptive Capacity

    DEFF Research Database (Denmark)

    Burcharth, Ana Luiza de Araújo; Lettl, Christopher; Ulhøi, John Parm

    2015-01-01

    on organizational characteristics that encourage experimentation. Specifically, we argue that characteristics such as slack resources, tolerance for failure, willingness to cannibalize and external openness are important organizational antecedents for knowledge absorption activities as they prevent inertia. Drawing...

  20. The origin of electromagnetically induced absorption

    International Nuclear Information System (INIS)

    Park, Jong Dae; Hwang, Sung Tae; Lee, Ho Seong; Park, Sung Jong; Cho, Hyuck; Choi, Won Sik

    2000-01-01

    Recently, there have been a lot of interests in the coherence superposition of atomic states which are formed by laser fields. Coherent population trapping(CTP), electromagnetically induced transparency(EIT), enhancement of the refractive index without absorption, lasing without inversion(LWI), and electromagnetically induced absorption(EIA) are the examples where coherence effects are important. Previously, the spontaneous transfer of the light-induced coherence from the excited level to the ground one was emphasized for the essential ingredient for electromagnetically induced absorption. In this paper, we have considered a case where linearly polarized coupling laser and probe laser are applied to the same degenerated ground and excited levels. We have solved the master equations for density matrix using time varying Hamiltonian and studied the absorption spectra at various conditions. We demonstrate that EIA can be observed without spontaneous transfer of the light-induced coherence in F g = 1 -> F e = 2 D2 transitions of Hydrogen atoms

  1. investigating water absorption and thickness swelling tendencies

    African Journals Online (AJOL)

    HOD

    In addition, G30E (30% reinforced glass fibre in the epoxy composite) was more resilient to moisture ... determine its suitability as per its water absorption and thickness ... lower thermal conductivity and low density as outlined in the Tables.

  2. Insulin analogues with improved absorption characteristics.

    Science.gov (United States)

    Brange, J; Hansen, J F; Langkjaer, L; Markussen, J; Ribel, U; Sørensen, A R

    1992-01-01

    The insulin preparations available today are not ideal for therapy as s.c. injection does not provide a physiological insulin profile. With the aim to improve the absorption properties recombinant DNA technology has been utilized to design novel insulin molecules with changed physico-chemical characteristics and hence altered subcutaneous absorption kinetics. Soluble, long-acting human insulin analogues in which the isoelectric point has been increased from 5.4 to approx. 7 are absorbed very slowly, providing a more constant basal insulin delivery with lower day-to-day variation than present protracted preparations. In addition they have better storage stability. Rapid-acting human insulin analogues with largely reduced self-association are absorbed substantially faster from subcutaneous tissue than current regular insulin and thus are better suited for bolus injection. The absorption kinetics of these analogues have been able to explain the mechanism behind the dose effect on insulin absorption rate.

  3. Attosecond transient absorption spectroscopy of molecular hydrogen

    International Nuclear Information System (INIS)

    Martín, Fernando; González-Castrillo, Alberto; Palacios, Alicia; Argenti, Luca; Cheng, Yan; Chini, Michael; Wang, Xiaowei; Chang, Zenghu

    2015-01-01

    We extend attosecond transient absorption spectroscopy (ATAS) to the study of hydrogen molecules, demonstrating the potential of the technique to resolve – simultaneously and with state resolution – both the electronic and nuclear dynamics. (paper)

  4. Thermodynamic analysis of absorption refrigeration cycles using the second law of thermodynamics method

    Energy Technology Data Exchange (ETDEWEB)

    Aphornratana, S; Eames, I W [Sheffield Univ. (United Kingdom). Dept. of Mechanical and Process Engineering

    1995-05-01

    The paper provides an easy to follow description of the second law (of thermodynamics) method as applied to a single-effect absorption refrigerator cycle. Results are presented in a novel graphical format, which aids insight and understanding of those factors that most affect the performance of absorption refrigerators, and which in turn provides strong indicators for the direction of future research. A novel method of calculating the entropy of lithium bromide solutions is offered. (author)

  5. Femtosecond X-ray Absorption Spectroscopy at a Hard X-ray Free Electron Laser

    DEFF Research Database (Denmark)

    Lemke, Henrik T.; Bressler, Christian; Chen, Lin X.

    2013-01-01

    X-ray free electron lasers (XFELs) deliver short (current (SASE based) XFELs, they can be used for measuring high......-quality X-ray absorption data and we report femtosecond time-resolved X-ray absorption near-edge spectroscopy (XANES) measurements of a spin-crossover system, iron(II) tris(2,2'-bipyridine) in water. The data indicate that the low-spin to high-spin transition can be modeled by single-exponential kinetics...

  6. A split imaging spectrometer for temporally and spatially resolved titanium absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hager, J. D., E-mail: hager@lanl.gov; Lanier, N. E.; Kline, J. L.; Flippo, K. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Bruns, H. C.; Schneider, M.; Saculla, M.; McCarville, T. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-11-15

    We present a temporally and a spatially resolved spectrometer for titanium x-ray absorption spectroscopy along 2 axial symmetric lines-of-sight. Each line-of-sight of the instrument uses an elliptical crystal to acquire both the 2p and 3p Ti absorption lines on a single, time gated channel of the instrument. The 2 axial symmetric lines-of-sight allow the 2p and 3p absorption features to be measured through the same point in space using both channels of the instrument. The spatially dependent material temperature can be inferred by observing the 2p and the 3p Ti absorption features. The data are recorded on a two strip framing camera with each strip collecting data from a single line-of-sight. The design is compatible for use at both the OMEGA laser and the National Ignition Facility. The spectrometer is intended to measure the material temperature behind a Marshak wave in a radiatively driven SiO{sub 2} foam with a Ti foam tracer. In this configuration, a broad band CsI backlighter will be used for a source and the Ti absorption spectrum measured.

  7. Ultrafast THz Saturable Absorption in Doped Semiconductors

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hoffmann, Matthias C.

    2011-01-01

    We demonstrate ultrafast THz saturable absorption in n-doped semiconductors by nonlinear THz time-domain spectroscopy. This effect is caused by the semiconductor conductivity modulation due to electron heating and satellite-valley scattering in strong THz fields.......We demonstrate ultrafast THz saturable absorption in n-doped semiconductors by nonlinear THz time-domain spectroscopy. This effect is caused by the semiconductor conductivity modulation due to electron heating and satellite-valley scattering in strong THz fields....

  8. Seasonal Solar Thermal Absorption Energy Storage Development.

    Science.gov (United States)

    Daguenet-Frick, Xavier; Gantenbein, Paul; Rommel, Mathias; Fumey, Benjamin; Weber, Robert; Gooneseker, Kanishka; Williamson, Tommy

    2015-01-01

    This article describes a thermochemical seasonal storage with emphasis on the development of a reaction zone for an absorption/desorption unit. The heat and mass exchanges are modelled and the design of a suitable reaction zone is explained. A tube bundle concept is retained for the heat and mass exchangers and the units are manufactured and commissioned. Furthermore, experimental results of both absorption and desorption processes are presented and the exchanged power is compared to the results of the simulations.

  9. Determination of hafnium by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Yoshida, Isao; Kobayashi, Hiroshi; Ueno, Keihei.

    1977-01-01

    Optimum conditions for atomic absorption spectrophotometric determination of hafnium were investigated by use of a Jarrel-Ash AA-1 instrument which was equipped with a premixed gas burner slotted 50 mm in length and 0.4 mm in width. Absorption of hafnium, which was atomized in an nitrous oxide-acetylene flame, was measured on a resonance line at 307.29 nm. The absorption due to hafnium was enhanced in the presence of ammonium fluoride and iron(III) ion, as shown in Figs. 2 and 3, depending on their concentration. The highest absorption was attained by the addition of (0.15 -- 0.3)M ammonium fluoride, 0.07 M of iron(III) ion and 0.05 M of hydrochloric acid. An excess of the additives decreased the absorption. The presence of zirconium, which caused a significant interference in the ordinary analytical methods, did not affect the absorption due to hafnium, if the zirconium concentration is less than 0.2 M. A standard procedure was proposed; A sample containing a few mg of hafnium was dissolved in a 25-ml volumetric flask, and ammonium fluoride, ferric nitrate and hydrochloric acid were added so that the final concentrations were 0.3, 0.07 and 0.05 M, respectively. Atomic absorption was measured on the aqueous solution in a nitrous oxide-acetylene flame and the hafnium content was calculated from the absorbance. Sensitivity was as high as 12.5 μg of Hf/ml/l% absorption. The present method is especially recommendable to the direct determination of hafnium in samples containing zirconium. (auth.)

  10. Systemic Absorption of Nanomaterials by Oral Exposure

    DEFF Research Database (Denmark)

    Binderup, Mona-Lise; Bredsdorff, Lea; Beltoft, Vibe Meister

    This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches.......This report and accompanying database systematically evaluates the reliability and relevance of the existing scientific literature regarding systemic absorption of nanomaterials by oral exposure and makes specific recommendations for future testing approaches....

  11. Ultrafast Transient Absorption Spectroscopy Investigation of Photoinduced Dynamics in POLY(3-HEXYLTHIOPHENE)-BLOCK-OLIGO(ANTHRACENE-9,10-DIYL)

    Science.gov (United States)

    Strain, Jacob; Rathnayake, Hemali; Liu, Jinjun

    2017-06-01

    Semiconducting polymer nanostructures featuring bulk heterojunction (BHJ) architecture are promising light harvesters in photovoltaic (PV) devices because they allow control of individual domain sizes, internal structure and ordering, as well as well-defined contact between the electron donor and acceptor. Power conversion efficiency (PCE) of PV devices strongly depends on photoinduced dynamics. Understanding and optimizing photoinduced charge transfer processes in BHJ's hence help improve the performance of PV devices and increase their PCE in particular. We have investigated the photoinduced dynamics of a block polymer containing moieties of poly-3-hexylthiophene (P3HT) and polyanthracene (PANT) in solution and in solid state with femtosecond transient absorption (TA) spectroscopy. The dynamics of the polymer PANT alone are also studied as a control. The TA spectra of PANT includes a strong excited state absorption centered at 610 (nm) along with a stimulated emission signal stretching past the detection limit into the UV region which is absent in the monomer's spectra in the detection window. The block polymer's TA spectra strongly resembles that of P3HT but a noticeable positive pull on P3HT's stimulated emission signal residing at 575-620 (nm) is indicative of the excited state absorption of PANT in the adjacent spectral region. The doubling of the lifetime exciton delocalization on the block polymer versus P3HT alone have alluded that the lifetime of P3HT is extended by the covalent addition of PANT. The current spectroscopic investigation represents an interesting example of photoinduced processes in systems with complex energy level structure. Studies of dependence of change generation and separation on composition, dimension, and morphology of the heterojunctions are in process.

  12. X-ray absorption fine structure spectroscopic determination of plutonium speciation at the Rocky Flats Environmental Technology Site

    International Nuclear Information System (INIS)

    Lezama-pacheco, Juan S.; Conradson, Steven D.; Clark, David L.

    2008-01-01

    X-ray Absorption Fine Structure spectroscopy was used to probe the speciation of the ppm level Pu in thirteen soil and concrete samples from the Rocky Flats Environmental Technology Site in support of the site remediation effort that has been successfully completed since these measurements. In addition to X-ray Absorption Near Edge Spectra, two of the samples yielded Extended X-ray Absorption Fine Structure spectra that could be analyzed by curve-fits. Most of these spectra exhibited features consistent with PU(IV), and more specificaJly, PuO 2+x -type speciation. Two were ambiguous, possibly indicating that Pu that was originally present in a different form was transforming into PuO 2+x , and one was interpreted as demonstrating the presence of an unusual Pu(VI) compound, consistent with its source being spills from a PUREX purification line onto a concrete floor and the resultant extreme conditions. These experimental results therefore validated models that predicted that insoluble PuO 2+x would be the most stable form of Pu in equilibrium with air and water even when the source terms were most likely Pu metal with organic compounds or a Pu fire. A corollary of these models' predictions and other in situ observations is therefore that the minimal transport of Pu that occurred on the site was via the resuspension and mobilization of colloidal particles. Under these conditions, the small amounts of diffusely distributed Pu that were left on the site after its remediation pose only a negligible hazard.

  13. Specific Features in Accessing European Funding

    Directory of Open Access Journals (Sweden)

    Elena Alexandra CĂLDĂRARU

    2011-12-01

    Full Text Available Abstract: European Funds are the European Union financial instruments in order to assist Member States in reducing the existing disparities between regions and between countries, and for harmonization with the economic, social and cultural European standards. This paper intends to present some general characteristics applicable to the most important financing programs, and also to outline certain features of the main financing lines, referring to investment projects development and their implementation, based on the Applicant Guides analysis. The paper treats institutional, legal, financial, technical, social and environmental aspects and outlines proposals and recommendations to achieve a better EU funds absorption and also a higher success rate of initiated projects. In knowledge-based economy circumstances, training consultancy specialists, that represent the intellectual capital in this area, will ensure the professional management of the developing process, submission and ongoing competitive projects, and will help enhance the funds absorption at national level. Thus, the European support for investments in ensuring sustainable growth will help overcoming the difficulties encountered by our country, and will sustain the Romanian economy recovery.

  14. Variations in the spectral values of specific absorption of phytoplankton

    Digital Repository Service at National Institute of Oceanography (India)

    Sathyendranath, S.; Lazzara, L.; Prieur, L.

    Absorption spectra of laboratory cultures of eight species of phytoplankton were studied. These spectra, normalized per unit of chlorophyll a concentration (specific absorption) show variability in magnitude and spectral form. Specific absorption...

  15. Core damage risk indicators

    International Nuclear Information System (INIS)

    Szikszai, T.

    1994-01-01

    The purpose of this document is to show a method for the fast recalculation of the PSA. To avoid the information loose, it is necessary to simplify the PSA models, or at least reorganize them. The method, introduced in this document, require that preparation, so we try to show, how to do that. This document is an introduction. This is the starting point of the work related to the development of the risk indicators. In the future, with the application of this method, we are going to show an everyday use of the PSA results to produce the indicators of the core damage risk. There are two different indicators of the plant safety performance, related to the core damage risk. The first is the core damage frequency indicator (CDFI), and the second is the core damage probability indicator (CDPI). Of course, we cannot describe all of the possible ways to use these indicators, rather we will try to introduce the requirements to establish such an indicator system and the calculation process

  16. Temporal resolution for the perception of features and conjunctions.

    Science.gov (United States)

    Bodelón, Clara; Fallah, Mazyar; Reynolds, John H

    2007-01-24

    The visual system decomposes stimuli into their constituent features, represented by neurons with different feature selectivities. How the signals carried by these feature-selective neurons are integrated into coherent object representations is unknown. To constrain the set of possible integrative mechanisms, we quantified the temporal resolution of perception for color, orientation, and conjunctions of these two features. We find that temporal resolution is measurably higher for each feature than for their conjunction, indicating that time is required to integrate features into a perceptual whole. This finding places temporal limits on the mechanisms that could mediate this form of perceptual integration.

  17. High temperature measurement of water vapor absorption

    Science.gov (United States)

    Keefer, Dennis; Lewis, J. W. L.; Eskridge, Richard

    1985-01-01

    An investigation was undertaken to measure the absorption coefficient, at a wavelength of 10.6 microns, for mixtures of water vapor and a diluent gas at high temperature and pressure. The experimental concept was to create the desired conditions of temperature and pressure in a laser absorption wave, similar to that which would be created in a laser propulsion system. A simplified numerical model was developed to predict the characteristics of the absorption wave and to estimate the laser intensity threshold for initiation. A non-intrusive method for temperature measurement utilizing optical laser-beam deflection (OLD) and optical spark breakdown produced by an excimer laser, was thoroughly investigated and found suitable for the non-equilibrium conditions expected in the wave. Experiments were performed to verify the temperature measurement technique, to screen possible materials for surface initiation of the laser absorption wave and to attempt to initiate an absorption wave using the 1.5 kW carbon dioxide laser. The OLD technique was proven for air and for argon, but spark breakdown could not be produced in helium. It was not possible to initiate a laser absorption wave in mixtures of water and helium or water and argon using the 1.5 kW laser, a result which was consistent with the model prediction.

  18. Transformation features in solid nitrous oxide

    International Nuclear Information System (INIS)

    Drobyshev, A.; Aldiyarov, A.; Korshikov, E.; Sokolov, D.; Kurnosov, V.

    2012-01-01

    The transformation features in cryocondensates of nitrous oxide were studied in the process of thermal cycling in the vicinity of the temperature T = 40 K. The research was aimed at figuring out the response of deformation and translational vibrational subsystems of the condensed nitrous oxide to these transformations. The temperature and the nature of thermally stimulated reactions in the films of nitrous oxide cryocondensates were determined. By measuring the vibrational spectra of the samples and by recording the changes in amplitude and position of the absorption bands characteristic of vibrations. Analysis of the IR spectra suggests that the transition from the amorphous state of nitrous oxide to the crystalline one is carried out in several stages, which account for the implementation of relaxation processes related to a particular type of vibrations of a nitrous oxide molecule. The difference in the temperatures of the transitions is determined by activation energies that are typical of this type of oscillation.

  19. Safety performance indicators program

    International Nuclear Information System (INIS)

    Vidal, Patricia G.

    2004-01-01

    In 1997 the Nuclear Regulatory Authority (ARN) initiated a program to define and implement a Safety Performance Indicators System for the two operating nuclear power plants, Atucha I and Embalse. The objective of the program was to incorporate a set of safety performance indicators to be used as a new regulatory tool providing an additional view of the operational performance of the nuclear power plants, improving the ability to detect degradation on safety related areas. A set of twenty-four safety performance indicators was developed and improved throughout pilot implementation initiated in July 1998. This paper summarises the program development, the main criteria applied in each stage and the results obtained. (author)

  20. Effect of water absorption on the mechanical properties of poly(3-hydroxybutyrate)/vegetable fiber composites

    Science.gov (United States)

    Marinho, Vithória A. D.; Carvalho, Laura H.; Canedo, Eduardo L.

    2015-05-01

    The present work studies the effect of water absorption on the performance of composites of poly(3-hydroxybutyrate) (PHB) - a fully biodegradable semi-crystalline thermoplastic obtained from renewable resources through low-impact biotechnological process, biocompatible and non-toxic - and vegetable fiber from the fruit (coconut) of babassu palm tree.Water resistance is an important characteristic of structural composites, that may exposed to rain and humid environments. Both water absorption capacity (water solubility in the material) and the rate of water absorption (controlled by the diffusivity of water in the material) are important parameters. However, water absorption per se may not be the most important characteristic, insofar as the performance and applications of the compounds. It is the effect of the water content on the ultimate properties that determine the suitability of the material for applications that involve prolonged exposure to water.PHB/babassu composites with 0-20% load were prepared in an internal mixer. Two different types of babassu fibers having two different article size ranges were compounded with PHB and test specimens molded by compression. The water absorption capacity and the kinetic constant of water absorption were measured in triplicate. Mechanical properties under tension were measured for dry and moist specimens with different amounts of absorbed water.Results indicate that the performance of the composites is comparable to that of the pure matrix. Water absorption capacity increases from 0.7% (pure PHB) to 4% (PHB/20% babassu), but the water diffusivity (4.10□8 cm2/s) was found to be virtually independent of the water absorption level. Water absorption results in moderate drop in elastic modulus (10-30% at saturation, according to fiber content) but has little effect on tensile strength and elongation at break. Fiber type and initial particle size do not have a significant effect on water absorption or mechanical properties.

  1. Romania's road to Euro zone. From structural balance to structural balance corrected for absorption

    Directory of Open Access Journals (Sweden)

    Aura-Gabriela SOCOL

    2013-02-01

    Full Text Available The sovereign-debt crisis in the European Union has determined the necessity to reform the signal indicators for the analysis of the public finances' sustainability. In this context, many of the developing/emerging countries consider that the informational value provided by the structural budget balance indicator is insufficient, especially during the periods characterized by absorption. The present study suggests the transition from classical structural budget balance (CAB in the structural balance corrected for absorption (CAAB and supports the use of an improved indicator of the structural budget balance with a superior informational relevance for the macro-economic policies decision makers. Based on the economic literature we will demonstrate that the structural budget balance indicator should be improved, in order to also take into consideration the deviation of the current account balance from its sustainable level, particularly in the stage of the economic cycle characterized by high absorption.

  2. UNTANGLING THE NEAR-IR SPECTRAL FEATURES IN THE PROTOPLANETARY ENVIRONMENT OF KH 15D

    Energy Technology Data Exchange (ETDEWEB)

    Arulanantham, Nicole A.; Herbst, William; Gilmore, Martha S.; Cauley, P. Wilson [Astronomy Department, Wesleyan University, Middletown, CT 06459 (United States); Leggett, S. K., E-mail: nicole.arulanantham@colorado.edu [Gemini Observatory (North), Hilo, HI 96720 (United States)

    2017-01-10

    We report on Gemini/GNIRS observations of the binary T Tauri system V582 Mon (KH 15D) at three orbital phases. These spectra allow us to untangle five components of the system: the photosphere and magnetosphere of star B, the jet, scattering properties of the ring material, and excess near-infrared (near-IR) radiation previously attributed to a possible self-luminous planet. We confirm an early-K subgiant classification for star B and show that the magnetospheric He i emission line is variable, possibly indicating increased mass accretion at certain times. As expected, the H{sub 2} emission features associated with the inner part of the jet show no variation with orbital phase. We show that the reflectance spectrum for the scattered light has a distinctive blue slope and spectral features consistent with scattering and absorption by a mixture of water and methane ice grains in the 1–50 μ m size range. This suggests that the methane frost line is closer than ∼5 au in this system, requiring that the grains be shielded from direct radiation. After correcting for features from the scattered light, jet, magnetosphere, and photosphere, we confirm the presence of leftover near-IR light from an additional source, detectable near minimum brightness. A spectral emission feature matching the model spectrum of a 10 M {sub J}, 1 Myr old planet is found in the excess flux, but other expected features from this model are not seen. Our observations, therefore, tentatively support the picture that a luminous planet is present within the system, although they cannot yet be considered definitive.

  3. Radiological features of pulmonary tuberculosis in human immunodeficiency virus-infected patients: correlation with the blood CD4 cell count; Patrones radiologicos de la tuberculosis pulmonar en pacientes con infeccion VIH: correlacion con el indice de linfocitos CD4 en sangre

    Energy Technology Data Exchange (ETDEWEB)

    Isusi, M.; Eguidazu, J.; Oleaga, L.; Grande, D. [Hospital de Basurto. Bilbao (Spain)

    2000-07-01

    To describe the radiological features of pulmonary tuberculosis (TB) in patients infected with human immunodeficiency virus (HIV) and its correlation with the blood CD4 cell count. We present 44 HIV+patients, 24 with CD4 cell counts of less than 200 cells/mm''3 (group A) and 20 in whom the CD4 counts surpassed this level (group B). We also assessed the chest x-ray images to determine whether or not there was any correlation with the blood CD4 cell counts. Fisher's exact test was used for the statistical study of the differences in the radiological findings in the two groups. The incidence of atypical features was significantly greater in the patients with CD4 cell counts of less than 200 cells/mm''3 (group A) than in those with CD4 counts of over 200 cells/mm''3 (group B). Among HIV+patients, those with a more intact immune status were more likely to present lung x-ray images typical of post-primary TB, with cavitary lesions in upper lobes. The group of patients in whom the immune deficiency was more marked showed a greater incidence of atypical pulmonary findings, more characteristics of primary TB. (Author)

  4. Solar Indices - Solar Flares

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  5. NOHSS Child Indicators

    Data.gov (United States)

    U.S. Department of Health & Human Services — Data for School year-end 1994 through year-end 2016. State oral health surveys are the data sources for these indicators. States periodically conduct independent...

  6. NOHSS Adult Indicators

    Data.gov (United States)

    U.S. Department of Health & Human Services — 2012-2014 (even years). Data from BRFSS for indicators of adult oral health for even years from 2012 through 2014. National estimates are represented by the median...

  7. Environmental indicators for buildings

    DEFF Research Database (Denmark)

    Dammann, Sven

    Environmental Indicators for Buildings are studied using two different perspectives: with a technological, environmental scientific departing point and with a social scientific departing point. Different relevant groups in the building sector are identified and analysed, using the Social...

  8. Solar Indices - Sunspot Numbers

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  9. Solar Indices Bulletin

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Solar Indices Bulletin is a prompt monthly information product that is distributed within two weeks after the observation month closes. For the month just ended,...

  10. Indicators and SEA

    DEFF Research Database (Denmark)

    Gao, Jingjing; Kørnøv, Lone; Christensen, Per

    Abstract: Indicators are widely used in SEA to measure, communicate and monitor impacts from a proposed policy, plan or programme, and can improve the effectiveness for the SEA by simplifying the complexity of both assessment and presentation. Indicators can be seen as part of the implementation...... and if the information requirement for different target groups is not addressed. Indicators are widely used in SEA to measure, communicate and monitor impacts from a proposed policy, plan or programme, and can improve the effectiveness for the SEA by simplifying the complexity of both assessment and presentation...... process helping to understand, communicate and, integrate important environmental issues in planning and decision-making. On the other hand, use of indicators can also limit SEA effectiveness, if the ones chosen are biased or limited, if the aggregation gives incorrect interpretation...

  11. Fishery Performance Indicators

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Performance indicators for landings, effort, revenue and distribution of revenue are collected for various fisheries nation-wide. The fisheries include catch and...

  12. Indicators: Sediment Enzymes

    Science.gov (United States)

    Sediment enzymes are proteins that are produced by microorganisms living in the sediment or soil. They are indicators of key ecosystem processes and can help determine which nutrients are affecting the biological community of a waterbody.

  13. Solar Indices - Plage Regions

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  14. Solar Indices - Solar Ultraviolet

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  15. Solar Indices - Solar Corona

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  16. Solar Indices - Solar Irradiance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  17. NOHSS Child Indicators

    Data.gov (United States)

    U.S. Department of Health & Human Services — Data for School year-end 1994 through year-end 2017. State oral health surveys are the data sources for these indicators. States periodically conduct independent...

  18. Tunable THz wave absorption by graphene-assisted plasmonic metasurfaces based on metallic split ring resonators

    International Nuclear Information System (INIS)

    Ahmadivand, Arash; Sinha, Raju; Karabiyik, Mustafa; Vabbina, Phani Kiran; Gerislioglu, Burak; Kaya, Serkan; Pala, Nezih

    2017-01-01

    Graphene plasmonics has been introduced as a novel platform to design various nano- and microstructures to function in a wide range of spectrum from optical to THz frequencies. Herein, we propose a tunable plasmonic metamaterial in the THz regime by using metallic (silver) concentric microscale split ring resonator arrays on a multilayer metasurface composed of silica and silicon layers. We obtained an absorption percentage of 47.9% including two strong Fano resonant dips in THz regime for the purely plasmonic metamaterial without graphene layer. Considering the data of an atomic graphene sheet (with the thickness of ~0.35 nm) in both analytical and experimental regimes obtained by prior works, we employed a graphene layer under concentric split ring resonator arrays and above the multilayer metasurface to enhance the absorption ratio in THz bandwidth. Our numerical and analytical results proved that the presence of a thin graphene layer enhances the absorption coefficient of MM to 64.35%, at the highest peak in absorption profile that corresponds to the Fano dip position. We also have shown that changing the intrinsic characteristics of graphene sheet leads to shifts in the position of Fano dips and variations in the absorption efficiency. The maximum percentage of absorption (~67%) was obtained for graphene-based MM with graphene layer with dissipative loss factor of 1477 Ω. Employing the antisymmetric feature of the split ring resonators, the proposed graphene-based metamaterial with strong polarization dependency is highly sensitive to the polarization angle of the incident THz beam.

  19. Interference-free mid-IR laser absorption detection of methane

    International Nuclear Information System (INIS)

    Pyun, Sung Hyun; Cho, Jungwan; Davidson, David F; Hanson, Ronald K

    2011-01-01

    A novel, mid-IR scanned-wavelength laser absorption diagnostic was developed for time-resolved, interference-free, absorption measurement of methane concentration. A differential absorption (peak minus valley) scheme was used that takes advantage of the structural differences of the absorption spectrum of methane and other hydrocarbons. A peak and valley wavelength pair was selected to maximize the differential cross-section (σ peak minus valley ) of methane for the maximum signal-to-noise ratio, and to minimize that of the interfering absorbers. Methane cross-sections at the peak and valley wavelengths were measured over a range of temperatures, 1000 to 2000 K, and pressures 1.3 to 5.4 atm. The cross-sections of the interfering absorbers were assumed constant over the small wavelength interval between the methane peak and valley features. Using this diagnostic, methane concentration time histories during n-heptane pyrolysis were measured behind reflected shock waves in a shock tube. The differential absorption scheme efficiently rejected the absorption interference and successfully recovered the vapor-phase methane concentration. These measurements allowed the comparison with methane concentration time-history simulations derived from a current n-heptane reaction mechanism (Sirjean et al 2009 A high-temperature chemical kinetic model of n-alkane oxidation JetSurF version 1.0)

  20. Absorption cross-section measurements of methane, ethane, ethylene and methanol at high temperatures

    KAUST Repository

    Alrefae, Majed

    2014-09-01

    Mid-IR absorption cross-sections are measured for methane, ethane, ethylene and methanol over 2800-3400 cm-1 (2.9-3.6 μm) spectral region. Measurements are carried out using a Fourier-Transform-Infrared (FTIR) spectrometer with temperatures ranging 296-1100 K and pressures near atmospheric. As temperature increases, the peak cross-sections decrease but the wings of the bands increase as higher rotational lines appear. Integrated band intensity is also calculated over the measured spectral region and is found to be a very weak function of temperature. The absorption cross-sections of the relatively small fuels studied here show dependence on the bath gas. This effect is investigated by studying the variation of absorption cross-sections at 3.392 μm using a HeNe laser in mixtures of fuel and nitrogen, argon, or helium. Mixtures of fuel with He have the highest value of absorption cross-sections followed by Ar and N2. Molecules with narrow absorption lines, such as methane and methanol, show strong dependence on bath gas than molecules with relatively broader absorption features i.e. ethane and ethylene. © 2014 Elsevier Inc. All rights reserved.