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Sample records for single-scattering phase function

  1. Investigation of snow single scattering properties based on first order Legendre phase function

    Science.gov (United States)

    Eppanapelli, Lavan Kumar; Casselgren, Johan; Wåhlin, Johan; Sjödahl, Mikael

    2017-04-01

    Angularly resolved bidirectional reflectance measurements were modelled by approximating a first order Legendre expanded phase function to retrieve single scattering properties of snow. The measurements from 10 different snow types with known density and specific surface area (SSA) were investigated. A near infrared (NIR) spectrometer was used to measure reflected light above the snow surface over the hemisphere in the wavelength region of 900-1650 nm. A solver based on discrete ordinate radiative transfer (DISORT) model was used to retrieve the estimated Legendre coefficients of the phase function and a correlation between the coefficients and physical properties of different snow types is investigated. Results of this study suggest that the first two coefficients of the first order Legendre phase function provide sufficient information about the physical properties of snow where the latter captures the anisotropic behaviour of snow and the former provides a relative estimate of the single scattering albedo of snow. The coefficients of the first order phase function were compared with the experimental data and observed that both the coefficients are in good agreement with the experimental data. These findings suggest that our approach can be applied as a qualitative tool to investigate physical properties of snow and also to classify different snow types.

  2. Single Scattering Detection in Turbin Media Using Single-Phase Structured Illumination Filtering

    Science.gov (United States)

    Berrocal, E.; Johnsson, J.; Kristensson, E.; Alden, M.

    2012-05-01

    This work shows a unique possibility of visualizing the exponential intensity decay due to light extinction, when laser adiation propagates through a homogeneous scattering edium. This observation implies that the extracted intensity mostly riginates from single scattering events. The filtering of this single light scattering intensity is performed by means of a single-phase structured illumination filtering approach. Results from numerical Monte Carlo simulation confirm the experimental findings for an extinction coefficient of μ_e = 0.36 mm^-1. This article demonstrates an original and reliable way of measuring the extinction coefficient of particulate turbid media based on sidescattering imaging. Such an approach has capabilities to replace the commonly used transmission measurement within the intermediate single-to multiple scattering regime where the optical depth ranges between 1 procedure and set-up. Applications of the technique has potential in probing challenging homogeneous scattering media, such as biomedical tissues, turbid emulsions, etc, in situations where dilution cannot be applied and where conventional transmission measurements fail.

  3. Electro-Optical Aerosol Phase Function Database PFNDAT2005

    National Research Council Canada - National Science Library

    Shirkey, Richard C; Tofsted, David H

    2005-01-01

    The Phase Function Database (PFNDAT) 2005 consists of a series of wavelength dependent phase functions, single scattering albedos, extinction coefficients, and asymmetry parameters of ten naturally occurring and four manmade aerosols...

  4. Single scattering properties of hydrosols

    Science.gov (United States)

    Mukherjee, L.; Zhai, P.; Hu, Y.

    2017-12-01

    The single scattering or inherent optical properties (IOPs) of hydrosols play an important role in the complete study of ocean optics, ocean color remote sensing, and ocean biogeochemistry research. Measurements show that hydrosols can be of various sizes and shapes, which suggests that general non-spherical models should be considered for the study of IOPs of hydrosols. In this work, the IOPs of randomly oriented non-spherical hydrosols of both absorbing and non-absorbing types are modeled using the Amsterdam Discrete Dipole Approximation (ADDA). We have defined the degree of optical non-sphericity (DONS) and investigated the dependence of DONS on refractive indices, sizes, and aspect ratios. For particles with non-unit aspect ratios, the magnitude of DONS increases with an increase of refractive index and aspect ratio. In general, the value of DONS increases with increase in particle size. The variation of DONS with respect to refractive indices and aspect ratios of the hydrosols makes it an important parameter in the study of ocean optics. Dependence of backscattering fraction on non-sphericity, size, and aspect ratio of the hydrosols is also demonstrated. The modeling of single scattering properties of hydrosols with different microphysical parameters would help to interpret the ocean radiation field measured by in situ or remote sensing sensors. Understanding the IOPs of hydrosols would lead to better radiative transfer models in ocean waters and new remote sensing technologies of hydrosol compositions.

  5. On Spectral Invariance of Single Scattering Albedo for Weakly Absorbing Wavelengths

    Science.gov (United States)

    Marshak, Alexander

    2012-01-01

    The single scattering albedo omega (sub 0 lambda) in atmospheric radiative transfer is the ratio of the scattering coefficient to the total extinction coefficient. For cloud water droplets both the scattering and absorption coefficients, thus the single scattering albedo, are functions of wavelength A and droplet size r. In this presentation we will show that for water droplets at weakly absorbing wavelengths, the ratio omega (sub 0 lambda)(r). The slope and intercept of the linear function are wavelength independent and sum to unity. This relationship allows for a representation of any single scattering albedo omega (sub 0 lambda) via one known spectrum omega (sub 0 lambda)(r(sub o)). We will provide a simple physical explanation of the discovered relationship. In addition to water droplets, similar linear relationships were found for the single scattering albedo of non-spherical ice crystals. The single scattering albedo $\\omega _ {0\\lambda }$ in atmospheric radiative transfer is the ratio of the scattering coefficient to the total extinction coefficient. For cloud water droplets both the scattering and absorption coefficients, and thus the single scattering albedo, are functions of wavelength $\\lambda $ and droplet size $r$. We show that for water droplets at weakly absorbing wavelengths, the ratio $\\omega _ {0\\lambda } (r)$/$\\omega _ {0\\lambda } (r_{0})$ of two single scattering albedo spectra for two different droplet sizes is a linear function of $\\omega _{0\\lambda }(r)$. The slope and intercept of the linear function are wavelength independent and sum to unity. This relationship allows for a representation of any single scattering albedo $\\omega_{0\\lambda }(r)$ via one known spectrum $\\omega_{0\\lambda }(r_{0})$. We provide a simple physical explanation of the discovered relationship. Similar linear relationships characterize the single scattering albedo of non-spherical ice crystals.

  6. A spectral geometric model for Compton single scatter in PET based on the single scatter simulation approximation

    Science.gov (United States)

    Kazantsev, I. G.; Olsen, U. L.; Poulsen, H. F.; Hansen, P. C.

    2018-02-01

    We investigate the idealized mathematical model of single scatter in PET for a detector system possessing excellent energy resolution. The model has the form of integral transforms estimating the distribution of photons undergoing a single Compton scattering with a certain angle. The total single scatter is interpreted as the volume integral over scatter points that constitute a rotation body with a football shape, while single scattering with a certain angle is evaluated as the surface integral over the boundary of the rotation body. The equations for total and sample single scatter calculations are derived using a single scatter simulation approximation. We show that the three-dimensional slice-by-slice filtered backprojection algorithm is applicable for scatter data inversion provided that the attenuation map is assumed to be constant. The results of the numerical experiments are presented.

  7. A phased translation function

    International Nuclear Information System (INIS)

    Read, R.J.; Schierbeek, A.J.

    1988-01-01

    A phased translation function, which takes advantage of prior phase information to determine the position of an oriented mulecular replacement model, is examined. The function is the coefficient of correlation between the electron density computed with the prior phases and the electron density of the translated model, evaluated in reciprocal space as a Fourier transform. The correlation coefficient used in this work is closely related to an overlap function devised by Colman, Fehlhammer and Bartels. Tests with two protein structures, one of which was solved with the help of the phased translation function, show that little phase information is required to resolve the translation problem, and that the function is relatively insensitive to misorientation of the model. (orig.)

  8. A spectral geometric model for Compton single scatter in PET based on the single scatter simulation approximation

    DEFF Research Database (Denmark)

    Kazantsev, I.G.; Olsen, Ulrik Lund; Poulsen, Henning Friis

    2018-01-01

    scatter is interpreted as the volume integral over scatter points that constitute a rotation body with a football shape, while single scattering with a certain angle is evaluated as the surface integral over the boundary of the rotation body. The equations for total and sample single scatter calculations...... are derived using a single scatter simulation approximation. We show that the three-dimensional slice-by-slice filtered backprojection algorithm is applicable for scatter data inversion provided that the attenuation map is assumed to be constant. The results of the numerical experiments are presented....

  9. Role of non-convexity in characterizing single-scattering properties for ensembles of non-spherical precipitation particles

    Science.gov (United States)

    Kuo, K.; Clune, T.; Pearson, C.; Olson, W. S.; Skofronick-Jackson, G.; Gravner, J.; Griffeath, D.

    2010-12-01

    This study improves upon an earlier, preliminary study using only three size bins based on maximum diameter in which it is found that the single-scattering properties of ensembles of non-spherical precipitation particles can be better characterized by considering the non-convexity of these particles. The difficulty of retrievals involving non-spherical particles stems not only from the fact that these particles are not spherical but also the fact that the shape composition of an ensemble of particles is usually unknown and the possibility of its mixture is infinite. Being able to adequately characterize the single-scattering properties of ensembles involving these non-spherical particles with as few parameters as possible is at the heart of solving this thorny remote sensing problem. Inspired by how well three parameters, i.e. water content, effective radius, and effective variance (or their equivalent), characterize the single-scattering properties of an ensemble of spherical particles of varying sizes, we set out to find additional parameters that generalize these three for ensembles of non-spherical particles. We find that a non-convexity measure appears to be one of these additional parameters. Non-convexity is expressed as a ratio of two effective radii derived from the moments of a given particle size distribution (PSD), each of which is in essence a ratio of ensemble particle volume to area. The effective radius in the numerator (denoted as rA) of the non-convexity ratio is based on the projection area of the particle ensemble whereas the one in the denominator (denoted as rS) is based on the surface area. In the preliminary study with PSDs having only three size bins, it is found that variations in the single-scattering properties, such as the scattering and extinction coefficients, the asymmetry factor, and even the scattering phase function, of a particle ensemble with a specified water content are very limited (practically non-existent), if 1) the habit

  10. Effective single scattering albedo estimation using regional climate model

    CSIR Research Space (South Africa)

    Tesfaye, M

    2011-09-01

    Full Text Available In this study, by modifying the optical parameterization of Regional Climate model (RegCM), the authors have computed and compared the Effective Single-Scattering Albedo (ESSA) which is a representative of VIS spectral region. The arid, semi...

  11. On Spectral Invariance of Single Scattering Albedo for Water Droplets and Ice Crystals at Weakly Absorbing Wavelengths

    Science.gov (United States)

    Marshak, Alexander; Knyazikhin, Yuri; Chiu, J. Christine; Wiscombe, Warren J.

    2012-01-01

    The single scattering albedo omega(sub O lambda) in atmospheric radiative transfer is the ratio of the scattering coefficient to the extinction coefficient. For cloud water droplets both the scattering and absorption coefficients, thus the single scattering albedo, are functions of wavelength lambda and droplet size r. This note shows that for water droplets at weakly absorbing wavelengths, the ratio omega(sub O lambda)(r)/omega(sub O lambda)(r (sub O)) of two single scattering albedo spectra is a linear function of omega(sub O lambda)(r). The slope and intercept of the linear function are wavelength independent and sum to unity. This relationship allows for a representation of any single scattering albedo spectrum omega(sub O lambda)(r) via one known spectrum omega(sub O lambda)(r (sub O)). We provide a simple physical explanation of the discovered relationship. Similar linear relationships were found for the single scattering albedo spectra of non-spherical ice crystals.

  12. Single scattering from nonspherical Chebyshev particles: A compendium of calculations

    Science.gov (United States)

    Wiscombe, W. J.; Mugnai, A.

    1986-01-01

    A large set of exact calculations of the scattering from a class of nonspherical particles known as Chebyshev particles' has been performed. Phase function and degree of polarization in random orientation, and parallel and perpendicular intensities in fixed orientations, are plotted for a variety of particles shapes and sizes. The intention is to furnish a data base against which both experimental data, and the predictions of approximate methods, can be tested. The calculations are performed with the widely-used Extended Boundary Condition Method. An extensive discussion of this method is given, including much material that is not easily available elsewhere (especially the analysis of its convergence properties). An extensive review is also given of all extant methods for nonspherical scattering calculations, as well as of the available pool of experimental data.

  13. Parameterizations for Cloud Overlapping and Shortwave Single-Scattering Properties for Use in General Circulation and Cloud Ensemble Models.

    Science.gov (United States)

    Chou, Ming-Dah; Suarez, Max J.; Ho, Chang-Hoi; Yan, Michael M.-H.; Lee, Kyu-Tae

    1998-02-01

    Parameterizations for cloud single-scattering properties and the scaling of optical thickness in a partial cloudiness condition have been developed for use in atmospheric models. Cloud optical properties are parameterized for four broad bands in the solar (or shortwave) spectrum; one in the ultraviolet and visible region and three in the infrared region. The extinction coefficient, single-scattering albedo, and asymmetry factor are parameterized separately for ice and water clouds. Based on high spectral-resolution calculations, the effective single-scattering coalbedo of a broad band is determined such that errors in the fluxes at the top of the atmosphere and at the surface are minimized. This parameterization introduces errors of a few percent in the absorption of shortwave radiation in the atmosphere and at the surface.Scaling of the optical thickness is based on the maximum-random cloud-overlapping approximation. The atmosphere is divided into three height groups separated approximately by the 400- and 700-mb levels. Clouds are assumed maximally overlapped within each height group and randomly overlapped among different groups. The scaling is applied only to the maximally overlapped cloud layers in individual height groups. The scaling as a function of the optical thickness, cloud amount, and the solar zenith angle is derived from detailed calculations and empirically adjusted to minimize errors in the fluxes at the top of the atmosphere and at the surface. Different scaling is used for direct and diffuse radiation. Except for a large solar zenith angle, the error in fluxes introduced by the scaling is only a few percent. In terms of absolute error, it is within a few watts per square meter.

  14. Using Single-Scattering Albedo Spectral Curvature to Characterize East Asian Aerosol Mixtures

    Science.gov (United States)

    Li, Jing; Carlson, Barbara E.; Lacis, Andrew A.

    2015-01-01

    Spectral dependence of aerosol single-scattering albedo (SSA) has been used to infer aerosol composition. In particular, aerosol mixtures dominated by dust absorption will have monotonically increasing SSA with wavelength while that dominated by black carbon absorption has monotonically decreasing SSA spectra. However, by analyzing SSA measured at four wavelengths, 440, 675, 870, and 1020 nm from the Aerosol Robotic Network data set, we find that the SSA spectra over East Asia are frequently peaked at 675 nm. In these cases, we suggest that SSA spectral curvature, defined as the negative of the second derivative of SSA as a function of wavelength, can provide additional information on the composition of these aerosol mixtures. Aerosol SSA spectral curvatures for East Asia during fall and winter are considerably larger than those found in places primarily dominated by biomass burning or dust aerosols. SSA curvature is found to increase as the SSA magnitude decreases. The curvature increases with coarse mode fraction (CMF) to a CMF value of about 0.4, then slightly decreases or remains constant at larger CMF. Mie calculations further verify that the strongest SSA curvature occurs at approx. 40% dust fraction, with 10% scattering aerosol fraction. The nonmonotonic SSA spectral dependence is likely associated with enhanced absorption in the shortwave by dust, absorption by black carbon at longer wavelengths, and also the flattened absorption optical depth spectral dependence due to the increased particle size.

  15. Aerosol single scattering albedo estimated across China from a combination of ground and satellite measurements

    Science.gov (United States)

    Kwon Ho Lee; Zhanqing Li; Man Sing Wong; Jinyuan Xin; Wang Yuesi; Wei Min Hao; Fengsheng Zhao

    2007-01-01

    Single scattering albedo (SSA) governs the strength of aerosols in absorbing solar radiation, but few methods are available to directly measure this important quantity. There currently exist many ground-based measurements of spectral transmittance from which aerosol optical thickness (AOT) are retrieved under clear sky conditions. Reflected radiances at the top of the...

  16. Spatial distribution of mineral dust single scattering albedo based on DREAM model

    Science.gov (United States)

    Kuzmanoski, Maja; Ničković, Slobodan; Ilić, Luka

    2016-04-01

    Mineral dust comprises a significant part of global aerosol burden. There is a large uncertainty in estimating role of dust in Earth's climate system, partly due to poor characterization of its optical properties. Single scattering albedo is one of key optical properties determining radiative effects of dust particles. While it depends on dust particle sizes, it is also strongly influenced by dust mineral composition, particularly the content of light-absorbing iron oxides and the mixing state (external or internal). However, an assumption of uniform dust composition is typically used in models. To better represent single scattering albedo in dust atmospheric models, required to increase accuracy of dust radiative effect estimates, it is necessary to include information on particle mineral content. In this study, we present the spatial distribution of dust single scattering albedo based on the Dust Regional Atmospheric Model (DREAM) with incorporated particle mineral composition. The domain of the model covers Northern Africa, Middle East and the European continent, with horizontal resolution set to 1/5°. It uses eight particle size bins within the 0.1-10 μm radius range. Focusing on dust episode of June 2010, we analyze dust single scattering albedo spatial distribution over the model domain, based on particle sizes and mineral composition from model output; we discuss changes in this optical property after long-range transport. Furthermore, we examine how the AERONET-derived aerosol properties respond to dust mineralogy. Finally we use AERONET data to evaluate model-based single scattering albedo. Acknowledgement We would like to thank the AERONET network and the principal investigators, as well as their staff, for establishing and maintaining the AERONET sites used in this work.

  17. Single-scattering properties of Platonic solids in geometrical-optics regime

    International Nuclear Information System (INIS)

    Zhang Zhibo; Yang Ping; Kattawar, George W.; Wiscombe, Warren J.

    2007-01-01

    We investigate the single-scattering properties of the Platonic solids with size parameters in the geometrical-optics regime at wavelengths 0.66 and 11 μm using the geometrical-optics method. The comparisons between the results for the Platonic solids and four types of spherical equivalence show that the equal-surface-area spherical equivalence has the smallest errors in terms of the extinction cross section at both wavelengths. At a wavelength of 0.66 μm, all the spherical equivalences substantially overestimate the asymmetry factors of the Platonic solids; and in the case of strong absorption, they underestimate the single-scattering albedo. The comparisons also show that the spherical equivalences cannot be used to describe the spatial distribution of scattered intensity associated with a prismatic polyhedron

  18. Importance sampling the Rayleigh phase function

    DEFF Research Database (Denmark)

    Frisvad, Jeppe Revall

    2011-01-01

    Rayleigh scattering is used frequently in Monte Carlo simulation of multiple scattering. The Rayleigh phase function is quite simple, and one might expect that it should be simple to importance sample it efficiently. However, there seems to be no one good way of sampling it in the literature....... This paper provides the details of several different techniques for importance sampling the Rayleigh phase function, and it includes a comparison of their performance as well as hints toward efficient implementation....

  19. Absorption line profiles in a moving atmosphere - A single scattering linear perturbation theory

    Science.gov (United States)

    Hays, P. B.; Abreu, V. J.

    1989-01-01

    An integral equation is derived which linearly relates Doppler perturbations in the spectrum of atmospheric absorption features to the wind system which creates them. The perturbation theory is developed using a single scattering model, which is validated against a multiple scattering calculation. The nature and basic properties of the kernels in the integral equation are examined. It is concluded that the kernels are well behaved and that wind velocity profiles can be recovered using standard inversion techniques.

  20. Seasonal Variability of Aerosol Single Scattering Albedo at Biomass Burning Sites in Southern Africa and Amazonia

    Science.gov (United States)

    Eck, T. F.; Holben, B. N.; Mukelabai, M. M.; Dubovik, O.; Smirnov, A.; Schafer, J. S.; Slutsker, I.

    2002-05-01

    Monitoring of the optical properties of primarily biomass burning aerosols in Mongu, Zambia was initiated in 1995, when an AERONET sun/sky radiometer site was established at the Mongu airport. For the biomass burning season months (July-November), we present monthly means of aerosol single scattering albedo (SSA), aerosol size distributions, and refractive indices from almucantar sky scan retrievals utilizing the algorithm of Dubovik and King (2000). The monthly mean single scattering albedo at 440 nm in Mongu was found to increase significantly from July (0.845) to October (0.93). The slope of the spectral dependence of aerosol single scattering albedo with wavelength decreased as SSA increased from July to October. However, there was no significant change in particle size in either the dominant accumulation or secondary coarse modes during these months. Similarly, seasonal SSA retrievals for Etosha Pan, Namibia also show increasing values through the burning season in 2000. We also analyze the seasonality of SSA for sites in biomass burning regions of Amazonia. We show maps of satellite detected fire counts which indicate that the regions of primary biomass burning shift significantly from July to October. Possible reasons for the seasonal changes in observed SSA include differences in aging to due transport speed and distance from source regions, differences in biomass fuel types in different regions (fraction of woody biomass versus grasses), and differences in fuel moisture content (October is the beginning of the rainy season on both continents).

  1. Microwave single-scattering properties of randomly oriented soft-ice hydrometeors

    Directory of Open Access Journals (Sweden)

    D. Casella

    2008-11-01

    Full Text Available Large ice hydrometeors are usually present in intense convective clouds and may significantly affect the upwelling radiances that are measured by satellite-borne microwave radiometers – especially, at millimeter-wavelength frequencies. Thus, interpretation of these measurements (e.g., for precipitation retrieval requires knowledge of the single scattering properties of ice particles. On the other hand, shape and internal structure of these particles (especially, the larger ones is very complex and variable, and therefore it is necessary to resort to simplifying assumptions in order to compute their single-scattering parameters.

    In this study, we use the discrete dipole approximation (DDA to compute the absorption and scattering efficiencies and the asymmetry factor of two kinds of quasi-spherical and non-homogeneous soft-ice particles in the frequency range 50–183 GHz. Particles of the first kind are modeled as quasi-spherical ice particles having randomly distributed spherical air inclusions. Particles of the second kind are modeled as random aggregates of ice spheres having random radii. In both cases, particle densities and dimensions are coherent with the snow hydrometeor category that is utilized by the University of Wisconsin – Non-hydrostatic Modeling System (UW-NMS cloud-mesoscale model. Then, we compare our single-scattering results for randomly-oriented soft-ice hydrometeors with corresponding ones that make use of: a effective-medium equivalent spheres, b solid-ice equivalent spheres, and c randomly-oriented aggregates of ice cylinders. Finally, we extend to our particles the scattering formulas that have been developed by other authors for randomly-oriented aggregates of ice cylinders.

  2. Equivalence of internal and external mixture schemes of single scattering properties in vector radiative transfer.

    Science.gov (United States)

    Mukherjee, Lipi; Zhai, Peng-Wang; Hu, Yongxiang; Winker, David M

    2017-05-10

    Polarized radiation fields in a turbid medium are influenced by single-scattering properties of scatterers. It is common that media contain two or more types of scatterers, which makes it essential to properly mix single-scattering properties of different types of scatterers in the vector radiative transfer theory. The vector radiative transfer solvers can be divided into two basic categories: the stochastic and deterministic methods. The stochastic method is basically the Monte Carlo method, which can handle scatterers with different scattering properties explicitly. This mixture scheme is called the external mixture scheme in this paper. The deterministic methods, however, can only deal with a single set of scattering properties in the smallest discretized spatial volume. The single-scattering properties of different types of scatterers have to be averaged before they are input to deterministic solvers. This second scheme is called the internal mixture scheme. The equivalence of these two different mixture schemes of scattering properties has not been demonstrated so far. In this paper, polarized radiation fields for several scattering media are solved using the Monte Carlo and successive order of scattering (SOS) methods and scattering media contain two types of scatterers: Rayleigh scatterers (molecules) and Mie scatterers (aerosols). The Monte Carlo and SOS methods employ external and internal mixture schemes of scatterers, respectively. It is found that the percentage differences between radiances solved by these two methods with different mixture schemes are of the order of 0.1%. The differences of Q/I, U/I, and V/I are of the order of 10 -5 ∼10 -4 , where I, Q, U, and V are the Stokes parameters. Therefore, the equivalence between these two mixture schemes is confirmed to the accuracy level of the radiative transfer numerical benchmarks. This result provides important guidelines for many radiative transfer applications that involve the mixture of

  3. Seasonal Trend of Aerosol Single Scattering Albedo at Biomass Burning Sites in Southern Africa

    Science.gov (United States)

    Eck, T. F.; Holben, B. N.; Reid, J. S.; Ward, D.; Mukelabai, M. M.; Piketh, S.; Hyer, E. J.; Dubovik, O.; Sinyuk, A.; Schafer, J. S.; Giles, D. M.; Smirnov, A.; Slutsker, I.

    2011-12-01

    A database of the optical properties of primarily biomass burning aerosols in Mongu, Zambia from multi-year monitoring at an AERONET sun-sky radiometer site was examined. For the biomass burning season months (July-November), we investigate the aerosol single scattering albedo (SSA), aerosol size distributions, and refractive indices from almucantar sky scan retrievals utilizing the algorithm of Dubovik and King (2000). The monthly mean single scattering albedo at 440 nm in Mongu was found to increase significantly from ~0.84 in July to ~0.93 in November (from 0.78 to 0.90 at 675 nm in these same months). There was no significant change in particle size, in either the dominant accumulation or secondary coarse modes during these months, nor any significant trend in the Angstrom Exponent (440-870 nm; r2=0.02). A significant downward seasonal trend in imaginary refractive index (r2=0.43) suggests a trend of decreasing black carbon content in the aerosol composition as the burning season progresses. Similarly, seasonal SSA retrievals for both the Etosha Pan, Namibia and Skukuza, South Africa AERONET sites also show increasing single scattering albedo values through the burning season. We show maps of satellite detected fire counts, which indicate that the regions of primary biomass burning in southern Africa shift significantly from July to October. Possible reasons for the seasonal changes in observed SSA include differences in biomass fuel types in different regions and seasons (fraction of woody biomass versus grasses), agricultural practices (Chitemene: in which woody fuels are burned at the end of the dry season), differences in fuel moisture content (as mid-October is the typical beginning of the rainy season) and differences in aging due to transport speed and distance from varying source regions. We also analyze the seasonality of SSA for sites in biomass burning regions of southern Amazonia, where no significant seasonal trend in SSA was detected.

  4. The applicability of physical optics in the millimetre and sub-millimetre spectral region. Part II: Application to a three-component model of ice cloud and its evaluation against the bulk single-scattering properties of various other aggregate models

    Science.gov (United States)

    Baran, Anthony J.; Ishimoto, Hiroshi; Sourdeval, Odran; Hesse, Evelyn; Harlow, Chawn

    2018-02-01

    The bulk single-scattering properties of various randomly oriented aggregate ice crystal models are compared and contrasted at a number of frequencies between 89 and 874 GHz. The model ice particles consist of the ten-branched plate aggregate, five-branched plate aggregate, eight-branched hexagonal aggregate, Voronoi ice aggregate, six-branched hollow bullet rosette, hexagonal column of aspect ratio unity, and the ten-branched hexagonal aggregate. The bulk single-scattering properties of the latter two ice particle models have been calculated using the light scattering methods described in Part I, which represent the two most extreme members of an ensemble model of cirrus ice crystals. In Part I, it was shown that the method of physical optics could be combined with the T-matrix at a size parameter of about 18 to compute the bulk integral ice optical properties and the phase function in the microwave to sufficient accuracy to be of practical value. Here, the bulk single-scattering properties predicted by the two ensemble model members and the Voronoi model are shown to generally bound those of all other models at frequencies between 89 and 874 GHz, thus representing a three-component model of ice cloud that can be generally applied to the microwave, rather than using many differing ice particle models. Moreover, the Voronoi model and hollow bullet rosette scatter similarly to each other in the microwave. Furthermore, from the various comparisons, the importance of assumed shapes of the particle size distribution as well as cm-sized ice aggregates is demonstrated.

  5. Exploring phase dependent functional gait variability.

    Science.gov (United States)

    Hamacher, Daniel; Hamacher, Dennis; Müller, Roy; Schega, Lutz; Zech, Astrid

    2017-04-01

    Gait variability is frequently used to evaluate the sensorimotor system and elderly fallers compared to non-fallers exhibit an altered variability in gait parameters during unchanged conditions. While gait variability is often interpreted as movement error, it is also necessary to change the gait pattern in order to react to internal and external perturbations. This phenomenon has been described as functional variability and ensures the stability of gait motor control. The aim of the current study is to explore the functional variability in relation to the different phases of the gait cycle (phase-dependent gait variability). Kinematics of the foot, shank and thigh were registered with inertial sensors (MTw2, Xsens Technologies B.V) in 25 older participants (70±6years) during normal overground walking. Phase-dependent variability was defined as the standard deviation of the Euclidean norm of the angular velocity data. To assess differences with respect to the variability of different body segments (foot, shank, and thigh), the statistical parametric mapping method was applied. In normal walking, the variability of the time-continuous foot kinematics during parts of the swing phase was higher compared to the shank (9-14% of swing phase, pgait. In fact, we found reduced variability in the time-continuous foot kinematics in mid swing during normal walking where also the minimum toe clearance event occurs. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Modeling Snow Aggregates and their Single Scattering Properties: Implications to Snowfall Remote Sensing

    Science.gov (United States)

    Nowell, H.; Liu, G.

    2012-12-01

    With the advent of satellites, we can now observe areas of the globe that have sparse to no ground data coverage. Both active and passive satellite sensors aboard satellites including CloudSat's Cloud Profiling Radar (CPR), Aqua's Advanced Microwave Scanning Radiometer (AMSR-E) and the upcoming Global Precipitation Measurement's (GPM) Dual-Frequency Precipitation Radar (DPR) and GPM Microwave Imager (GMI) study ice and snow particles. A good retrieval algorithm for these satellite sensors can only be developed when the single scattering properties of the snowflakes are accurately calculated in radiative transfer models. This becomes crucial at frequencies at and above the W-band when aggregate ice crystals become detectable by satellite radiometers. Snowflakes are often modeled as spheres or oblate spheroids to ease the complexity of calculations, despite the fact that they are typically aggregates of crystals. For improved accuracy in satellite remote sensing, it is important to model snowflakes as close to nature as possible. Several recent studies model flakes as pristine crystal types [Liu, 2008], generate aggregate flakes as fractals [Ishimoto, 2008] or via the Monte Carlo method [Maruyama and Fujioshi, 2005]. Modeling snowflakes as pristine crystals, however, has the drawback of not accurately reflecting snowflakes as most tend to be aggregates of different crystal types. Other studies where aggregates are generated tend to overlook size-density relationships of aggregate flakes or other studied statistical parameters such as aspect ratio. In an effort to improve available single-scattering properties of aggregate flakes, we developed a new method of generating flakes. Starting out with a six-bullet rosette crystal of accurate size and density, aggregate flakes are generated with two different bullet rosette crystal sizes of 200 and/or 400 microns in maximum dimension. The flakes similarly follow size-density relationships of aggregate as determined from

  7. Modeling the radiation transfer of discontinuous canopies: results for gap probability and single-scattering contribution

    Science.gov (United States)

    Zhao, Feng; Zou, Kai; Shang, Hong; Ji, Zheng; Zhao, Huijie; Huang, Wenjiang; Li, Cunjun

    2010-10-01

    In this paper we present an analytical model for the computation of radiation transfer of discontinuous vegetation canopies. Some initial results of gap probability and bidirectional gap probability of discontinuous vegetation canopies, which are important parameters determining the radiative environment of the canopies, are given and compared with a 3- D computer simulation model. In the model, negative exponential attenuation of light within individual plant canopies is assumed. Then the computation of gap probability is resolved by determining the entry points and exiting points of the ray with the individual plants via their equations in space. For the bidirectional gap probability, which determines the single-scattering contribution of the canopy, a gap statistical analysis based model was adopted to correct the dependence of gap probabilities for both solar and viewing directions. The model incorporates the structural characteristics, such as plant sizes, leaf size, row spacing, foliage density, planting density, leaf inclination distribution. Available experimental data are inadequate for a complete validation of the model. So it was evaluated with a three dimensional computer simulation model for 3D vegetative scenes, which shows good agreement between these two models' results. This model should be useful to the quantification of light interception and the modeling of bidirectional reflectance distributions of discontinuous canopies.

  8. The effect of the global UV irradiance measurement accuracy on the single scattering albedo retrieval

    Directory of Open Access Journals (Sweden)

    S. Kazadzis

    2010-08-01

    Full Text Available The possibility of measuring aerosol optical absorption properties in the UV spectral range such as single scattering albedo (SSA, using remote sensing techniques, is currently an open scientific issue. We investigate the limitations on calculating column average SSA using a combination of global UV spectral measurements (that are comon in various UV monitoring stations worldwide with radiative transfer modeling. To point out the difficulties in such a retrieval we have used the travelling reference spectroradiometer QASUME (Quality Assurance of Spectral Ultraviolet Measurements in Europe results from 27 visits to UV monitoring stations around Europe. We have used the QASUME instrument as relative reference, analyzing absolute differences and also temporal and spectral deviations of UV irraidances, that are used as basic input for the SSA retrieval.

    The results comparing the mean SSA derived by all instruments, measuring synchronous UV spectra, showed that 5 were within ± 0.02 difference from the SSA calculated from the QASUME instrument, while 17 were within ± 0.04, for the Solar zenith angle of 60 degrees. As for the uncertainty that has been calculated using the 2σ standard deviation of the spectral measurements, a mean 0.072 and 0.10 (2σ uncertainties have been calculated for 60° and 30°, respectively. Based on the fact that additional uncertainties would be introduced in the SSA retrieval from AOD model input accuracy, assymetry parameter assumptions, we show that only very few instrumnents could be able to detect long term SSA changes. However, such measurements/results ar useful in order to retrieve SSA at UV wavelengths, a product needed for various applications such as, inputs for modeling radiative forcing studies and satellite retrieval algorithms.

  9. Radiation pressure in galactic disks: stability, turbulence, and winds in the single-scattering limit

    Science.gov (United States)

    Wibking, Benjamin D.; Thompson, Todd A.; Krumholz, Mark R.

    2018-04-01

    The radiation force on dust grains may be dynamically important in driving turbulence and outflows in rapidly star-forming galaxies. Recent studies focus on the highly optically-thick limit relevant to the densest ultra-luminous galaxies and super star clusters, where reprocessed infrared photons provide the dominant source of electromagnetic momentum. However, even among starburst galaxies, the great majority instead lie in the so-called "single-scattering" limit, where the system is optically-thick to the incident starlight, but optically-thin to the re-radiated infrared. In this paper we present a stability analysis and multidimensional radiation-hydrodynamic simulations exploring the stability and dynamics of isothermal dusty gas columns in this regime. We describe our algorithm for full angle-dependent radiation transport based on the discontinuous Galerkin finite element method. For a range of near-Eddington fluxes, we show that the medium is unstable, producing convective-like motions in a turbulent atmosphere with a scale height significantly inflated compared to the gas pressure scale height and mass-weighted turbulent energy densities of ˜0.01 - 0.1 of the midplane radiation energy density, corresponding to mass-weighted velocity dispersions of Mach number ˜0.5 - 2. Extrapolation of our results to optical depths of 103 implies maximum turbulent Mach numbers of ˜20. Comparing our results to galaxy-averaged observations, and subject to the approximations of our calculations, we find that radiation pressure does not contribute significantly to the effective supersonic pressure support in star-forming disks, which in general are substantially sub-Eddington. We further examine the time-averaged vertical density profiles in dynamical equilibrium and comment on implications for radiation-pressure-driven galactic winds.

  10. Retrievals and uncertainty analysis of aerosol single scattering albedo from MFRSR measurements

    International Nuclear Information System (INIS)

    Yin, Bangsheng; Min, Qilong; Joseph, Everette

    2015-01-01

    Aerosol single scattering albedo (SSA) can be retrieved from the ratio of diffuse horizontal and direct normal fluxes measured from multifilter rotating shadowband radiometer (MFRSR). In this study, the measurement channels at 415 nm and 870 nm are selected for aerosol optical depth (AOD) and Angstrom coefficient retrievals, and the measurements at 415 nm are used for aerosol SSA retrievals with the constraint of retrieved Angstrom coefficient. We extensively assessed various issues impacting on the accuracy of SSA retrieval from measurements to input parameters and assumptions. For cloud-free days with mean aerosol loading of 0.13–0.60, our sensitivity study indicated that: (1) 1% calibration uncertainty can result in 0.8–3.7% changes in retrieved SSA; (2) without considering the cosine respond correction and/or forward scattering correction will result in underestimation of 1.1–3.3% and/or 0.73% in retrieved SSA; (3) an overestimation of 0.1 in asymmetry factor can result in an underestimation of 2.54–3.4% in retrieved SSA; (4) for small aerosol loading (e.g., 0.13), the uncertainty associated with the choice of Rayleigh optical depth value can result in non-negligible change in retrieved SSA (e.g., 0.015); (5) an uncertainty of 0.05 for surface albedo can result in changes of 1.49–5.4% in retrieved SSA. We applied the retrieval algorithm to the MFRSR measurements at the Atmospheric Radiation Measurements (ARM) Southern Great Plains (SGP) site. The retrieved results of AOD, Angstrom coefficient, and SSA are basically consistent with other independent measurements from co-located instruments at the site. - Highlights: • Aerosol SSA is derived from MFRSR measured diffuse to direct normal irradiance ratio. • We extensively assessed various issues impacting on the accuracy of SSA retrieval. • The issues are mainly from measurements and model input parameters and assumptions. • We applied the retrieval algorithm to the MFRSR measurements at ARM SGP

  11. Industrial applications of multi-functional, multi-phase reactors

    NARCIS (Netherlands)

    Harmsen, G.J.; Chewter, L.A.

    1999-01-01

    To reveal trends in the design and operation of multi-functional, multi-phase reactors, this paper describes, in historical sequence, three industrial applications of multi-functional, multi-phase reactors developed and operated by Shell Chemicals during the last five decades. For each case, we

  12. On quantum mechanical phase-space wave functions

    DEFF Research Database (Denmark)

    Wlodarz, Joachim J.

    1994-01-01

    An approach to quantum mechanics based on the notion of a phase-space wave function is proposed within the Weyl-Wigner-Moyal representation. It is shown that the Schrodinger equation for the phase-space wave function is equivalent to the quantum Liouville equation for the Wigner distribution...

  13. Scattering Phase Functions of Constituents of Mineral Dust Aerosols ...

    African Journals Online (AJOL)

    The results show that there is increasing asymmetry and complexity of the phase functions with increasing radial sizes for each of the selected constituents: Illite, Kaolinite, Montmorillonte, Hematite, Calcite and Quartz. The behaviour of these constituents as observed by their phase functions provide information on the ...

  14. Programming cancer through phase-functionalized silicon based biomaterials

    Science.gov (United States)

    Premnath, Priyatha; Venkatakrishnan, Krishnan; Tan, Bo

    2015-01-01

    Applications of biomaterials in cancer therapy has been limited to drug delivery systems and markers in radiation therapy. In this article, we introduce the concept of phase-functionalization of silicon to preferentially select cancer cell populations for survival in a catalyst and additive free approach. Silicon is phase-functionalized by the interaction of ultrafast laser pulses, resulting in the formation of rare phases of SiO2 in conjunction with differing silicon crystal lattices. The degree of phase-functionalization is programmed to dictate the degree of repulsion of cancer cells. Unstable phases of silicon oxides are synthesized during phase-functionalization and remain stable at ambient conditions. This change in phase of silicon as well as formation of oxides contributes to changes in surface chemistry as well as surface energy. These material properties elicit in precise control of migration, cytoskeleton shape, direction and population. To the best of our knowledge, phase-functionalized silicon without any changes in topology or additive layers and its applications in cancer therapy has not been reported before. This unique programmable phase-functionalized silicon has the potential to change current trends in cancer research and generate focus on biomaterials as cancer repelling or potentially cancer killing surfaces. PMID:26043430

  15. Aerosol single-scattering albedo retrieval over North Africa using critical reflectance

    Science.gov (United States)

    Wells, Kelley C.

    The sign and magnitude of the aerosol radiative forcing over bright surfaces is highly dependent on the absorbing properties of the aerosol. Thus, the determination of aerosol forcing over desert regions requires accurate information about the aerosol single-scattering albedo (SSA). However, the brightness of desert surfaces complicates the retrieval of aerosol optical properties using passive space-based measurements. The aerosol critical reflectance is one parameter that can be used to relate top-of-atmosphere (TOA) reflectance changes over land to the aerosol absorption properties, without knowledge of the underlying surface properties or aerosol loading. Physically, the parameter represents the TOA reflectance at which increased aerosol scattering due to increased aerosol loading is balanced by increased absorption of the surface contribution to the TOA reflectance. It can be derived by comparing two satellite images with different aerosol loading, assuming that the surface reflectance and background aerosol are similar between the two days. In this work, we explore the utility of the critical reflectance method for routine monitoring of spectral aerosol absorption from space over North Africa, a region that is predominantly impacted by absorbing dust and biomass burning aerosol. We derive the critical reflectance from Moderate Resolution Spectroradiometer (MODIS) Level 1B reflectances in the vicinity of two Aerosol Robotic Network (AERONET) stations: Tamanrasset, a site in the Algerian Sahara, and Banizoumbou, a Sahelian site in Niger. We examine the sensitivity of the critical reflectance parameter to aerosol physical and optical properties, as well as solar and viewing geometry, using the Santa Barbara DISORT Radiative Transfer (SBDART) model, and apply our findings to retrieve SSA from the MODIS critical reflectance values. We compare our results to AERONET-retrieved estimates, as well as to measurements of the TOA albedo and surface fluxes from the

  16. RETRIEVAL OF AEROSOL PHASE FUNCTION AND POLARIZED PHASE FUNCTION FROM POLARIZATION OF SKYLIGHT FOR DIFFERENT OBSERVATION GEOMETRIES

    Directory of Open Access Journals (Sweden)

    L. Li

    2018-04-01

    Full Text Available The phase function and polarized phase function are important optical parameters, which describe scattering properties of atmospheric aerosol particles. Polarization of skylight induced by the scattering processes is sensitive to the scattering properties of aerosols. The Stokes parameters I, Q, U and the polarized radiance Lp of skylight measured by the CIMEL dual-polar sun-sky radiometer CE318- DP can be use to retrieve the phase function and polarized phase function, respectively. Two different observation geometries (i.e., the principal plane and almucantar are preformed by the CE318-DP to detect skylight polarization. Polarization of skylight depends on the illumination and observation geometries. For the same solar zenith angle, retrievals of the phase function and the polarized phase function are still affected by the observation geometry. The performance of the retrieval algorithm for the principal plane and almucantar observation geometries was assessed by the numerical experiments at two typical high and low sun’s positions (i.e. solar zenith angles are equal to 45° and 65°. Comparing the results for the principal plane and almucantar geometries, it is recommended to utilize the principal plane observations to retrieve the phase function when the solar zenith angle is small. The Stokes parameter U and the polarized radiance Lp from the almucantar observations are suggested to retrieve the polarized phase function, especially for short wavelength channels (e.g., 440 and 500 nm.

  17. Saharan dust events at the Jungfraujoch: detection by wavelength dependence of the single scattering albedo and first climatology analysis

    Directory of Open Access Journals (Sweden)

    M. Collaud Coen

    2004-01-01

    Full Text Available Scattering and absorption coefficients have been measured continuously at several wavelengths since March 2001 at the high altitude site Jungfraujoch (3580ma.s.l.. From these data, the wavelength dependences of the Ångström exponent and particularly of the single scattering albedo are determined. While the exponent of the single scattering albedo usually increases with wavelength, it decreases with wavelength during Saharan dust events (SDE due to the greater size of the mineral aerosol particles and their different chemical composition. This change in the sign of the single scattering exponent turns out to be a sensitive means for detecting Saharan dust events. The occurrence of SDE detected by this new method was confirmed by visual inspection of filter colors and by studying long-range back-trajectories. An examination of SDE over a 22-month period shows that SDE are more frequent during the March-June period as well as during October and November. The trajectory analysis indicated a mean traveling time of 96.5h, with the most important source countries situated in the northern and north-western part of the Saharan desert. Most of the SDE do not lead to a detectable increase of the 48-h total suspended particulate matter (TSP concentration at the Jungfraujoch. During Saharan dust events, the average contribution of this dust to hourly TSP at the Jungfraujoch is 16µg/m3, which corresponds to an annual mean of 0.8µg/m3 or 24% of TSP.

  18. Wigner's function and other distribution functions in mock phase spaces

    International Nuclear Information System (INIS)

    Balazs, N.L.; Jennings, B.K.

    1983-06-01

    This review deals with the methods of associating functions with quantum mechanical operators in such a manner that these functions should furnish conveniently semiclassical approximations. We present a unified treatment of methods and result which usually appear under the expressions Wigner's functions, Weyl's association, Kirkwood's expansion, Glauber's coherent state representation, etc.; we also construct some new associations. The mathematical paraphernalia are collected in the appendices

  19. Phase-function method for Hulthen-modified separable potentials

    International Nuclear Information System (INIS)

    Laha, U.; Jana, A.K.; Nandi, T.K.

    1991-01-01

    The Hulthen-modified separable potentials are treated within the framework of the phase-function method and a closed form expression for s-wave scattering phase shift is obtained. Specializing to a rank one separable potential, the limiting conditions in which the Hulthen-modified phase shift goes over to its Coulomb counterpart was found out. The usefulness of the approach by means of a model calculation is demonstrated. (author). 16 refs

  20. Analytical Approximations to Seawater Optical Phase Functions of Scattering

    National Research Council Canada - National Science Library

    Haltrin, Vladimir I

    2004-01-01

    .... The paper contains data tables showing the following: inherent optical properties and coefficients for 15 Petzold phase functions of light scattering measured off the Southern California coast, San Diego Harbor, and near the Bahama Islands...

  1. Wigner function and Schroedinger equation in phase-space representation

    International Nuclear Information System (INIS)

    Chruscinski, Dariusz; Mlodawski, Krzysztof

    2005-01-01

    We discuss a family of quasidistributions (s-ordered Wigner functions of Agarwal and Wolf [Phys. Rev. D 2, 2161 (1970); Phys. Rev. D 2, 2187 (1970); Phys. Rev. D 2, 2206 (1970)]) and its connection to the so-called phase space representation of the Schroedinger equation. It turns out that although Wigner functions satisfy the Schroedinger equation in phase space, they have a completely different interpretation

  2. Numerical construction of 'optimal' nonoscillating amplitude and phase functions

    International Nuclear Information System (INIS)

    Matzkin, A.; Lombardi, M.

    2002-01-01

    A numerical recipe for the construction of nonoscillating amplitude and phase functions for potentials with a single minimum is given. We give different examples illustrating the recipe, showing the usefulness of the procedure for the construction of basis functions in bound-state scattering processes, such as those described by quantum defect theory. The resulting amplitude and accumulated phase functions are coined as 'optimal' nonoscillating (as a function of the space and energy variables) because they are the counterpart for the quantum problem of the classical action for the analog semiclassical problem

  3. Phase-function method for Coulomb-distorted nuclear scattering

    Energy Technology Data Exchange (ETDEWEB)

    Sett, G.C.; Laha, U.; Talukdar, B.

    1988-09-21

    The phase-function method is very effective in treating quantum mechanical scattering problems for short-range local potentials. We adapt the phase method to deal with Coulomb plus Graz non-local separable potentials and derive a closed-form expression for the scattering phase shift. Our approach to the problem circumvents in a rather natural way the typical difficulties of incorporating the Coulomb interaction in a nuclear phase-shift calculation. We demonstrate the usefulness of our constructed expression by means of a model calculation.

  4. Generalized second-order Coulomb phase shift functions

    International Nuclear Information System (INIS)

    Rosendorff, S.

    1982-01-01

    Some specific properties and the evaluation of the generalized second-order Coulomb phase shift functions (two-dimensional integrals of four spherical cylinder functions) are discussed. The dependence on the three momenta k 1 ,k-bar,k 2 , corresponding to the final, intermediate, and initial states is illustrated

  5. Accurate single-scattering simulation of ice cloud using the invariant-imbedding T-matrix method and the physical-geometric optics method

    Science.gov (United States)

    Sun, B.; Yang, P.; Kattawar, G. W.; Zhang, X.

    2017-12-01

    The ice cloud single-scattering properties can be accurately simulated using the invariant-imbedding T-matrix method (IITM) and the physical-geometric optics method (PGOM). The IITM has been parallelized using the Message Passing Interface (MPI) method to remove the memory limitation so that the IITM can be used to obtain the single-scattering properties of ice clouds for sizes in the geometric optics regime. Furthermore, the results associated with random orientations can be analytically achieved once the T-matrix is given. The PGOM is also parallelized in conjunction with random orientations. The single-scattering properties of a hexagonal prism with height 400 (in units of lambda/2*pi, where lambda is the incident wavelength) and an aspect ratio of 1 (defined as the height over two times of bottom side length) are given by using the parallelized IITM and compared to the counterparts using the parallelized PGOM. The two results are in close agreement. Furthermore, the integrated single-scattering properties, including the asymmetry factor, the extinction cross-section, and the scattering cross-section, are given in a completed size range. The present results show a smooth transition from the exact IITM solution to the approximate PGOM result. Because the calculation of the IITM method has reached the geometric regime, the IITM and the PGOM can be efficiently employed to accurately compute the single-scattering properties of ice cloud in a wide spectral range.

  6. Experimental Phase Functions of Millimeter-sized Cosmic Dust Grains

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz, O.; Moreno, F.; Guirado, D.; Escobar-Cerezo, J. [Instituto de Astrofísica de Andalucía, CSIC, Glorieta de la Astronomía s/n, E-18008 Granada (Spain); Vargas-Martín, F. [Department of Electromagnetism and Electronics, University of Murcia, E-30100 Murcia (Spain); Min, M. [SRON Netherlands Institute for Space Research, Sobornnelaan 2, 3584 CA Utrecht (Netherlands); Hovenier, J. W. [Astronomical Institute “Anton Pannekoek,” University of Amsterdam, Science Park 904, 1098 XH, Amsterdam (Netherlands)

    2017-09-01

    We present the experimental phase functions of three types of millimeter-sized dust grains consisting of enstatite, quartz, and volcanic material from Mount Etna, respectively. The three grains present similar sizes but different absorbing properties. The measurements are performed at 527 nm covering the scattering angle range from 3° to 170°. The measured phase functions show two well-defined regions: (i) soft forward peaks and (ii) a continuous increase with the scattering angle at side- and back-scattering regions. This behavior at side- and back-scattering regions is in agreement with the observed phase functions of the Fomalhaut and HR 4796A dust rings. Further computations and measurements (including polarization) for millimeter-sized grains are needed to draw some conclusions about the fluffy or compact structure of the dust grains.

  7. Experimental Phase Functions of Millimeter-sized Cosmic Dust Grains

    International Nuclear Information System (INIS)

    Muñoz, O.; Moreno, F.; Guirado, D.; Escobar-Cerezo, J.; Vargas-Martín, F.; Min, M.; Hovenier, J. W.

    2017-01-01

    We present the experimental phase functions of three types of millimeter-sized dust grains consisting of enstatite, quartz, and volcanic material from Mount Etna, respectively. The three grains present similar sizes but different absorbing properties. The measurements are performed at 527 nm covering the scattering angle range from 3° to 170°. The measured phase functions show two well-defined regions: (i) soft forward peaks and (ii) a continuous increase with the scattering angle at side- and back-scattering regions. This behavior at side- and back-scattering regions is in agreement with the observed phase functions of the Fomalhaut and HR 4796A dust rings. Further computations and measurements (including polarization) for millimeter-sized grains are needed to draw some conclusions about the fluffy or compact structure of the dust grains.

  8. SCAP-82, Single Scattering, Albedo Scattering, Point-Kernel Analysis in Complex Geometry

    International Nuclear Information System (INIS)

    Disney, R.K.; Vogtman, S.E.

    1987-01-01

    1 - Description of problem or function: SCAP solves for radiation transport in complex geometries using the single or albedo scatter point kernel method. The program is designed to calculate the neutron or gamma ray radiation level at detector points located within or outside a complex radiation scatter source geometry or a user specified discrete scattering volume. Geometry is describable by zones bounded by intersecting quadratic surfaces within an arbitrary maximum number of boundary surfaces per zone. Anisotropic point sources are describable as pointwise energy dependent distributions of polar angles on a meridian; isotropic point sources may also be specified. The attenuation function for gamma rays is an exponential function on the primary source leg and the scatter leg with a build- up factor approximation to account for multiple scatter on the scat- ter leg. The neutron attenuation function is an exponential function using neutron removal cross sections on the primary source leg and scatter leg. Line or volumetric sources can be represented as a distribution of isotropic point sources, with un-collided line-of-sight attenuation and buildup calculated between each source point and the detector point. 2 - Method of solution: A point kernel method using an anisotropic or isotropic point source representation is used, line-of-sight material attenuation and inverse square spatial attenuation between the source point and scatter points and the scatter points and detector point is employed. A direct summation of individual point source results is obtained. 3 - Restrictions on the complexity of the problem: - The SCAP program is written in complete flexible dimensioning so that no restrictions are imposed on the number of energy groups or geometric zones. The geometric zone description is restricted to zones defined by boundary surfaces defined by the general quadratic equation or one of its degenerate forms. The only restriction in the program is that the total

  9. Density Functional Theory for Phase-Ordering Transitions

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jianzhong [Univ. of California, Riverside, CA (United States)

    2016-03-30

    Colloids display astonishing structural and dynamic properties that can be dramatically altered by modest changes in the solution condition or an external field. This complex behavior stems from a subtle balance of colloidal forces and intriguing mesoscopic and macroscopic phase transitions that are sensitive to the processing conditions and the dispersing environment. Whereas the knowledge on the microscopic structure and phase behavior of colloidal systems at equilibrium is now well-advanced, quantitative predictions of the dynamic properties and the kinetics of phase-ordering transitions in colloids are not always realized. Many important mesoscopic and off-equilibrium colloidal states remain poorly understood. The proposed research aims to develop a new, unifying approach to describe colloidal dynamics and the kinetics of phase-ordering transitions based on accomplishments from previous work for the equilibrium properties of both uniform and inhomogeneous systems and on novel concepts from the state-of-the-art dynamic density functional theory. In addition to theoretical developments, computational research is designed to address a number of fundamental questions on phase-ordering transitions in colloids, in particular those pertinent to a competition of the dynamic pathways leading to various mesoscopic structures, off-equilibrium states, and crystalline phases. By providing a generic theoretical framework to describe equilibrium, metastable as well as non-ergodic phase transitions concurrent with the colloidal self-assembly processes, accomplishments from this work will have major impacts on both fundamental research and technological applications.

  10. Scattering phase functions of horizontally oriented hexagonal ice crystals

    International Nuclear Information System (INIS)

    Chen Guang; Yang Ping; Kattawar, George W.; Mishchenko, Michael I.

    2006-01-01

    Finite-difference time domain (FDTD) solutions are first compared with the corresponding T-matrix results for light scattering by circular cylinders with specific orientations. The FDTD method is then utilized to study the scattering properties of horizontally oriented hexagonal ice plates at two wavelengths, 0.55 and 12 μm. The phase functions of horizontally oriented ice plates deviate substantially from their counterparts obtained for randomly oriented particles. Furthermore, we compute the phase functions of horizontally oriented ice crystal columns by using the FDTD method along with two schemes for averaging over the particle orientations. It is shown that the phase functions of hexagonal ice columns with horizontal orientations are not sensitive to the rotation about the principal axes of the particles. Moreover, hexagonal ice crystals and circular cylindrical ice particles have similar optical properties, particularly, at a strongly absorbing wavelength, if the two particle geometries have the same length and aspect ratio defined as the ratio of the radius or semi-width of the cross section of a particle to its length. The phase functions for the two particle geometries are slightly different in the case of weakly absorbing plates with large aspect ratios. However, the solutions for circular cylinders agree well with their counterparts for hexagonal columns

  11. Contrast-transfer-function phase retrieval based on compressed sensing.

    Science.gov (United States)

    Villanueva-Perez, Pablo; Arcadu, Filippo; Cloetens, Peter; Stampanoni, Marco

    2017-03-15

    We report on a new contrast-transfer-function (CTF) phase-retrieval method based on the alternating direction method of multipliers (ADMMs), which allows us to exploit any compressed sensing regularization scheme reflecting the sparsity of the investigated object. The proposed iterative algorithm retrieves accurate phase maps from highly noisy single-distance projection microscopy data and is characterized by a stable convergence, not bounded to the prior knowledge of the object support or to the initialization strategy. Experiments on simulated and real datasets show that ADMM-CTF yields reconstructions with a substantial lower amount of artifacts and enhanced signal-to-noise ratio compared to the standard analytical inversion.

  12. Nanoscale phase boundaries: a new twist to novel functionalities

    Science.gov (United States)

    Zhang, J. X.; Zeches, R. J.; He, Q.; Chu, Y.-H.; Ramesh, R.

    2012-09-01

    In functional materials, nanoscale phase boundaries exhibit exotic phenomena that are notably absent in their parent phases. Over the past two decades, much of the research into complex oxides (such as cuprate superconductors, CMR manganites and relaxor ferroelectrics) has demonstrated the key role that nanoscale inhomogeneities play in controlling the electronic and/or ionic structure of these materials. One of the key characteristics in such systems is the strong susceptibility to external perturbations, such as magnetic, electric and mechanical fields. A direct consequence of the accommodation of a large number of cationic substitutions in complex oxides is the emergence of a number of physical phenomena from essentially the same crystal framework. Recently, multiferroic behavior, which is characterized by the co-existence and potential coupling of multiple ferroic order parameters, has captured considerable worldwide research interest. The perovskite, BiFeO3, exhibits robust ferroelectricity coupled with antiferromagnetism at room temperature. A rather unique feature of this material system is its ability to ``morph'' its ground state when an external mechanical constraint is imposed on it. A particularly striking example is observed when a large (~4 to 5%) compressive strain is imposed on a thin film through the epitaxial constraint from the underlying substrate. Under these conditions, the ground state rhombohedral phase transforms into a tetragonal-like (or a derivative thereof) phase with a rather large unit cell (c/a ratio of ~1.26). When the epitaxial constraint is partially relaxed by increasing the film thickness, this tetragonal-like phase evolves into a ``mixed-phase'' state, consisting of a nanoscale admixture of the rhombohedral-like phase embedded in the tetragonal-like phase. Such a system gives us a new pathway to explore a variety of mechanical, magnetic and transport phenomena in constrained dimensions. This article reviews our progress to date

  13. Wavelength dependence of Ångström exponent and single scattering albedo observed by skyradiometer in Seoul, Korea

    Science.gov (United States)

    Koo, Ja-Ho; Kim, Jhoon; Lee, Jaehwa; Eck, Thomas F.; Lee, Yun Gon; Park, Sang Seo; Kim, Mijin; Jung, Ukkyo; Yoon, Jongmin; Mok, Jungbin; Cho, Hi-Ku

    2016-11-01

    Absorption and scattering characteristics of various aerosol events are investigated using 2-years of measurements from a skyradiometer at Yonsei University in Seoul, Korea. Both transported dust and anthropogenic aerosols are observed at distinct geo-location of Seoul, a megacity located a few thousand kilometers away from dust source regions in China. We focus on the wavelength dependence of Ångström exponent (AE) and single scattering albedo (SSA), showing the characteristics of regional aerosols. The correlation between spectral SSAs and AEs calculated using different wavelength pairs generally indicates relatively weak absorption of fine-mode aerosols (urban pollution and/or biomass burning) and strong absorption of coarse-mode aerosols (desert dust) at this location. AE ratio (AER), a ratio of AEs calculated using wavelength pair between shorter (340-675 nm) and longer wavelength pair (675-1020 nm) correlates differently with SSA according to the dominant size of local aerosols. Correlations between SSA and AER show strong absorption of aerosols for AER 2.0. Based on the seasonal pattern of wavelength dependence of AER and SSA, this correlation difference looks to reveal the separated characteristics of transported dust and anthropogenic particles from urban pollution respectively. The seasonal characteristics of AER and SSAs also show that the skyradiometer measurement with multiple wavelengths may be able to detect the water soluble brown carbon, one of the important secondary organic aerosols in the summertime atmospheric composition.

  14. Aerosol single-scattering albedo and asymmetry parameter from MFRSR observations during the ARM Aerosol IOP 2003

    Directory of Open Access Journals (Sweden)

    E. I. Kassianov

    2007-06-01

    Full Text Available Multi-filter Rotating Shadowband Radiometers (MFRSRs provide routine measurements of the aerosol optical depth (τ at six wavelengths (0.415, 0.5, 0.615, 0.673, 0.870 and 0.94 μm. The single-scattering albedo (π0 is typically estimated from the MFRSR measurements by assuming the asymmetry parameter (g. In most instances, however, it is not easy to set an appropriate value of g due to its strong temporal and spatial variability. Here, we introduce and validate an updated version of our retrieval technique that allows one to estimate simultaneously π0 and g for different types of aerosol. We use the aerosol and radiative properties obtained during the Atmospheric Radiation Measurement (ARM Program's Aerosol Intensive Operational Period (IOP to validate our retrieval in two ways. First, the MFRSR-retrieved optical properties are compared with those obtained from independent surface, Aerosol Robotic Network (AERONET, and aircraft measurements. The MFRSR-retrieved optical properties are in reasonable agreement with these independent measurements. Second, we perform radiative closure experiments using the MFRSR-retrieved optical properties. The calculated broadband values of the direct and diffuse fluxes are comparable (~5 W/m2 to those obtained from measurements.

  15. Cathodoluminescence and phase-change functionality of metallic nanoparticles

    OpenAIRE

    Denisyuk, A.I.

    2009-01-01

    Nanoscale resolution cathodoluminescence (CL) has been used to demonstrate and investigate the functionality of nanoparticle-based components for future nanophotonic phase-change memory and optical antenna applications. An integrated experimental system based on a scanning electron microscope was developed for the fabrication and in situ characterization of nanoparticles. It was equipped with an atomic beam source for gallium nanoparticle growth, a liquid-nitrogen-cooled cryostat to control s...

  16. QCD Green's Functions and Phases of Strongly-Interacting Matter

    Directory of Open Access Journals (Sweden)

    Schaefer B.J.

    2011-04-01

    Full Text Available After presenting a brief summary of functional approaches to QCD at vanishing temperatures and densities the application of QCD Green's functions at non-vanishing temperature and vanishing density is discussed. It is pointed out in which way the infrared behavior of the gluon propagator reflects the (de-confinement transition. Numerical results for the quark propagator are given thereby verifying the relation between (de--confinement and dynamical chiral symmetry breaking (restoration. Last but not least some results of Dyson-Schwinger equations for the color-superconducting phase at large densities are shown.

  17. Crystalline molecular machines: function, phase order, dimensionality, and composition.

    Science.gov (United States)

    Vogelsberg, Cortnie S; Garcia-Garibay, Miguel A

    2012-03-07

    The design of molecular machines is stimulated by the possibility of developing new materials with complex physicochemical and mechanical properties that are responsive to external stimuli. Condensed-phase matter with anisotropic molecular order and controlled dynamics, also defined as amphidynamic crystals, offers a promising platform for the design of bulk materials capable of performing such functions. Recent studies have shown that it is possible to engineer molecular crystals and extended solids with Brownian rotation about specific axes that can be interfaced with external fields, which may ultimately be used to design novel optoelectronic materials. Structure/function relationships of amphidynamic materials have been characterized, establishing the blueprints to further engineer sophisticated function. However, the synthesis of amphidynamic molecular machines composed of multiple "parts" is essential to realize increasingly complex behavior. Recent progress in amphidynamic multicomponent systems suggests that sophisticated functions similar to those of simple biomolecular machines may eventually be within reach. This journal is © The Royal Society of Chemistry 2012

  18. Impact of brown and clear carbon on light absorption enhancement, single scatter albedo and absorption wavelength dependence of black carbon

    Directory of Open Access Journals (Sweden)

    D. A. Lack

    2010-05-01

    Full Text Available The presence of clear coatings on atmospheric black carbon (BC particles is known to enhance the magnitude of light absorption by the BC cores. Based on calculations using core/shell Mie theory, we demonstrate that the enhancement of light absorption (EAbs by atmospheric black carbon (BC when it is coated in mildly absorbing material (CBrown is reduced relative to the enhancement induced by non-absorbing coatings (CClear. This reduction, sensitive to both the CBrown coating thickness and imaginary refractive index (RI, can be up to 50% for 400 nm radiation and 25% averaged across the visible radiation spectrum for reasonable core/shell diameters. The enhanced direct radiative forcing possible due to the enhancement effect of CClear is therefore reduced if the coating is absorbing. Additionally, the need to explicitly treat BC as an internal, as opposed to external, mixture with CBrown is shown to be important to the calculated single scatter albedo only when models treat BC as large spherical cores (>50 nm. For smaller BC cores (or fractal agglomerates consideration of the BC and CBrown as an external mixture leads to relatively small errors in the particle single scatter albedo of <0.03. It has often been assumed that observation of an absorption Angström exponent (AAE>1 indicates absorption by a non-BC aerosol. Here, it is shown that BC cores coated in CClear can reasonably have an AAE of up to 1.6, a result that complicates the attribution of observed light absorption to CBrown within ambient particles. However, an AAE<1.6 does not exclude the possibility of CBrown; rather CBrown cannot be confidently assigned unless AAE>1.6. Comparison of these model

  19. Closed fringe demodulation using phase decomposition by Fourier basis functions.

    Science.gov (United States)

    Kulkarni, Rishikesh; Rastogi, Pramod

    2016-06-01

    We report a new technique for the demodulation of a closed fringe pattern by representing the phase as a weighted linear combination of a certain number of linearly independent Fourier basis functions in a given row/column at a time. A state space model is developed with the weights of the basis functions as the elements of the state vector. The iterative extended Kalman filter is effectively utilized for the robust estimation of the weights. A coarse estimate of the fringe density based on the fringe frequency map is used to determine the initial row/column to start with and subsequently the optimal number of basis functions. The performance of the proposed method is evaluated with several noisy fringe patterns. Experimental results are also reported to support the practical applicability of the proposed method.

  20. Chemical Characterization and Single Scattering Albedo of Atmospheric Aerosols Measured at Amami-Oshima, Southwest Japan, During Spring Seasons

    Science.gov (United States)

    Tsuruta, H.; Yabuki, M.; Takamura, T.; Sudo, S.; Yonemura, S.; Shirasuna, Y.; Hirano, K.; Sera, K.; Maeda, T.; Hayasaka, T.; Nakajima, T.

    2008-12-01

    An intensive field program was performed to measure atmospheric aerosols at Amami-Oshima, a small island located at southwest Japan, in the spring season of 2001, 2003, and 2005 under the ACE-Asia, APEX and ABC-EAREX2005 projects. Chemical analysis of the fine and coarse aerosols was made for elemental carbon (EC) and organic carbon, water soluble ions, and trace elements. Single scattering albedo (SSA) of aerosols was independently estimated by two methods. The one (SSAc) is by chemical compositions assuming a half internal mixture between EC and non sea-salt sulfate, and the other (SSAo) is by optical measurements of scattering coefficient and absorption coefficient. The backward trajectory analysis showed that the aerosol concentrations in the air masses arrived at Amami, were much higher from the Asian Continent than from other regions, and two types of aerosol enhancement were observed. The one was caused by polluted air masses from the urban-industrial area of east-coast China, the other was by high mineral dusts due to large- scale dust storms in the desert regions of northwest China. The SSAc was in a range of 0.87-0.98, and in good agreement with the SSAo after some corrections for original scattering and absorption coefficients. The SSAc showed no significant difference between the air masses from the polluted area and the desert regions. The negative correlation between the SSAc and EC was divided into two groups depending on the concentration of non sea-salt sulfate, while the increase in mineral dusts did not show any correlation with the SSAc.

  1. Laboratory estimate of the regional shortwave refractive index and single scattering albedo of mineral dust from major sources worldwide

    Science.gov (United States)

    Di Biagio, C.; Formenti, P.; Caponi, L.; Cazaunau, M.; Pangui, E.; Journet, E.; Nowak, S.; Caquineau, S.; Andreae, M. O.; Kandler, K.; Saeed, T.; Piketh, S.; Seibert, D.; Williams, E.; Balkanski, Y.; Doussin, J. F.

    2017-12-01

    Mineral dust is one of the most abundant aerosol species in the atmosphere and strongly contributes to the global and regional direct radiative effect. Still large uncertainties persist on the magnitude and overall sign of the dust direct effect, where indeed one of the main unknowns is how much mineral dust absorbs light in the shortwave (SW) spectral range. Aerosol absorption is represented both by the imaginary part (k) of the complex refractive index or the single scattering albedo (SSA, i.e. the ratio of the scattering to extinction coefficient). In this study we present a new dataset of SW complex refractive indices and SSA for mineral dust aerosols obtained from in situ measurements in the 4.2 m3 CESAM simulation chamber at LISA (Laboratoire Interuniversitaire des Systemes Atmospheriques) in Créteil, France. Investigated dust aerosol samples were issued from major desert sources worldwide, including the African Sahara and Sahel, Eastern Asia, the Middle East, Southern Africa, Australia, and the Americas, with differing iron oxides content. Results from the present study provide a regional mapping of the SW absorption by dust and show that the imaginary part of the refractive index largely varies (by up to a factor 6, 0.003-0.02 at 370 nm and 0.001-0.003 at 950 nm) for the different source areas due to the change in the particle iron oxide content. The SSA for dust varies between 0.75-0.90 at 370 nm and 0.95-0.99 at 950 nm, with the largest absorption observed for Sahelian and Australian dust aerosols. Our range of variability for k and SSA is well bracketed by already published literature estimates, but suggests that regional‒dependent values should be used in models. The possible relationship between k and the dust iron oxides content is investigated with the aim of providing a parameterization of the regional‒dependent dust absorption to include in climate models.

  2. Aerosol ultraviolet absorption experiment (2002 to 2004), part 2: absorption optical thickness, refractive index, and single scattering albedo

    Science.gov (United States)

    Krotkov, Nickolay A.; Bhartia, Pawan K.; Herman, Jay R.; Slusser, James R.; Scott, Gwendolyn R.; Labow, Gordon J.; Vasilkov, Alexander P.; Eck, Tom; Doubovik, Oleg; Holben, Brent N.

    2005-04-01

    Compared to the visible spectral region, very little is known about aerosol absorption in the UV. Without such information it is impossible to quantify the causes of the observed discrepancy between modeled and measured UV irradiances and photolysis rates. We report results of a 17-month aerosol column absorption monitoring experiment conducted in Greenbelt, Maryland, where the imaginary part of effective refractive index k was inferred from the measurements of direct and diffuse atmospheric transmittances by a UV-multifilter rotating shadowband radiometer [UV-MFRSR, U.S. Department of Agriculture (USDA) UV-B Monitoring and Research Network]. Colocated ancillary measurements of aerosol effective particle size distribution and refractive index in the visible wavelengths [by CIMEL sun-sky radiometers, National Aeronautics and Space Administration (NASA) Aerosol Robotic Network (AERONET)], column ozone, surface pressure, and albedo constrain the forward radiative transfer model input, so that a unique solution for k is obtained independently in each UV-MFRSR spectral channel. Inferred values of k are systematically larger in the UV than in the visible wavelengths. The inferred k values enable calculation of the single scattering albedo ω, which is compared with AERONET inversions in the visible wavelengths. On cloud-free days with high aerosol loadings [τext(440)>0.4], ω is systematically lower at 368 nm (=0.94) than at 440 nm (=0.96), however, the mean ω differences (0.02) are within expected uncertainties of ω retrievals (~0.03). The inferred ω is even lower at shorter UV wavelengths (~=0.92), which might suggest the presence of selectively UV absorbing aerosols. We also find that decreases with decrease in aerosol loading. This could be due to real changes in the average aerosol composition between summer and winter months at the Goddard Space Flight Center (GSFC) site.

  3. Holographic partition functions and phases for higher genus Riemann surfaces

    International Nuclear Information System (INIS)

    Maxfield, Henry; Ross, Simon F; Way, Benson

    2016-01-01

    We describe a numerical method to compute the action of Euclidean saddle points for the partition function of a two-dimensional holographic CFT on a Riemann surface of arbitrary genus, with constant curvature metric. We explicitly evaluate the action for the saddles for genus two and map out the phase structure of dominant bulk saddles in a two-dimensional subspace of the moduli space. We discuss spontaneous breaking of discrete symmetries, and show that the handlebody bulk saddles always dominate over certain non-handlebody solutions. (paper)

  4. Generalised partition functions: inferences on phase space distributions

    Directory of Open Access Journals (Sweden)

    R. A. Treumann

    2016-06-01

    Full Text Available It is demonstrated that the statistical mechanical partition function can be used to construct various different forms of phase space distributions. This indicates that its structure is not restricted to the Gibbs–Boltzmann factor prescription which is based on counting statistics. With the widely used replacement of the Boltzmann factor by a generalised Lorentzian (also known as the q-deformed exponential function, where κ = 1∕|q − 1|, with κ, q ∈ R both the kappa-Bose and kappa-Fermi partition functions are obtained in quite a straightforward way, from which the conventional Bose and Fermi distributions follow for κ → ∞. For κ ≠ ∞ these are subject to the restrictions that they can be used only at temperatures far from zero. They thus, as shown earlier, have little value for quantum physics. This is reasonable, because physical κ systems imply strong correlations which are absent at zero temperature where apart from stochastics all dynamical interactions are frozen. In the classical large temperature limit one obtains physically reasonable κ distributions which depend on energy respectively momentum as well as on chemical potential. Looking for other functional dependencies, we examine Bessel functions whether they can be used for obtaining valid distributions. Again and for the same reason, no Fermi and Bose distributions exist in the low temperature limit. However, a classical Bessel–Boltzmann distribution can be constructed which is a Bessel-modified Lorentzian distribution. Whether it makes any physical sense remains an open question. This is not investigated here. The choice of Bessel functions is motivated solely by their convergence properties and not by reference to any physical demands. This result suggests that the Gibbs–Boltzmann partition function is fundamental not only to Gibbs–Boltzmann but also to a large class of generalised Lorentzian distributions as well as to the

  5. Aerosol optical properties at Lampedusa (Central Mediterranean. 2. Determination of single scattering albedo at two wavelengths for different aerosol types

    Directory of Open Access Journals (Sweden)

    D. Meloni

    2006-01-01

    Full Text Available Aerosol optical properties were retrieved from direct and diffuse spectral irradiance measurements made by a multi-filter rotating shadowband radiometer (MFRSR at the island of Lampedusa (35.5° N, 12.6° E, in the Central Mediterranean, in the period July 2001–September 2003. In a companion paper (Pace et al., 2006 the aerosol optical depth (AOD and Ångström exponent were used together with airmass backward trajectories to identify and classify different aerosol types. The MFRSR diffuse-to-direct ratio (DDR at 415.6 nm and 868.7 nm for aerosol classified as 'biomass burning-urban/industrial', originating primarily from the European continent, and desert dust, originating from the Sahara, is used in this study to estimate the aerosol single scattering albedo (SSA. A detailed radiative transfer model is initialised with the measured aerosol optical depth; calculations are performed at the two wavelengths varying the SSA values until the modelled DDR matches the MFRSR observations. Sensitivity studies are performed to estimate how uncertainties on AOD, DDR, asymmetry factor (g, and surface albedo influence the retrieved SSA values. The results show that a 3% variation of AOD or DDR produce a change of about 0.02 in the retrieved SSA value at 415.6 and 868.7 nm; a ±0.06 variation of the asymmetry factor g produces a change of the estimated SSA of <0.04 at 415.6 nm, and <0.06 at 868.7 nm; finally, an increase of the assumed surface albedo of 0.05 causes very small changes (0.01–0.02 in the retrieved SSA. The calculations show that the SSA of desert dust (DD increases with wavelength, from 0.81±0.05 at 415.6 nm to 0.94±0.05 at 868.7 nm; on the contrary, the SSA of urban/industrial (UN aerosols decreases from 0.96±0.02 at 415.6 nm to 0.87±0.07 at 868.7 nm; the SSA of biomass burning (BB particles is 0.82±0.04 at 415.6 nm and 0.80±0.05 at 868.7 nm. Episodes of UN aerosols occur usually in June and July; long lasting BB aerosol episodes

  6. Application of AERONET Single Scattering Albedo and Absorption Angstrom Exponent to Classify Dominant Aerosol Types during DRAGON Campaigns

    Science.gov (United States)

    Giles, D. M.; Holben, B. N.; Eck, T. F.; Schafer, J.; Crawford, J. H.; Kim, J.; Sano, I.; Liew, S.; Salinas Cortijo, S. V.; Chew, B. N.; Lim, H.; Smirnov, A.; Sorokin, M.; Kenny, P.; Slutsker, I.

    2013-12-01

    Aerosols can have major implications on human health by inducing respiratory diseases due to inhalation of fine particles from biomass burning smoke or industrial pollution and on radiative forcing whereby the presence of absorbing aerosol particles (e.g., black carbon) increases atmospheric heating. Aerosol classification techniques have utilized aerosol loading and aerosol properties derived from multi-spectral and multi-angle observations by ground-based (e.g., AERONET) and satellite instrumentation (e.g., MISR). Aerosol Robotic Network (AERONET) data have been utilized to determine aerosol types by implementing various combinations of measured aerosol optical depth or retrieved size and absorption aerosol properties (e.g., Gobbi et al., 2007; Russell et al., 2010). Giles et al. [2012] showed single scattering albedo (SSA) relationship with extinction Angstrom exponent (EAE) can provide an estimate of the general classification of dominant aerosol types (i.e., desert dust, urban/industrial pollution, biomass burning smoke, and mixtures) based on data from ~20 AERONET sites located in known aerosol source regions. In addition, the absorption Angstrom exponent relationship with EAE can provide an indication of the dominant absorbing aerosol type such as dust, black carbon, brown carbon, or mixtures of them. These classification techniques are applied to the AERONET Level 2.0 quality assured data sets collected during Distributed Regional Aerosol Gridded Observational Network (DRAGON) campaigns in Maryland (USA), Japan, South Korea, Singapore, Penang (Malaysia), and California (USA). An analysis of aerosol type classification for DRAGON sites is performed as well as an assessment of the spatial variability of the aerosol types for selected DRAGON campaigns. Giles, D. M., B. N. Holben, T. F. Eck, A. Sinyuk, A. Smirnov, I. Slutsker, R. R. Dickerson, A. M. Thompson, and J. S. Schafer (2012), An analysis of AERONET aerosol absorption properties and classifications

  7. Phase Function Determination in Support of Orbital Debris Size Estimation

    Science.gov (United States)

    Hejduk, M. D.; Cowardin, H. M.; Stansbery, Eugene G.

    2012-01-01

    To recover the size of a space debris object from photometric measurements, it is necessary to determine its albedo and basic shape: if the albedo is known, the reflective area can be calculated; and if the shape is known, the shape and area taken together can be used to estimate a characteristic dimension. Albedo is typically determined by inferring the object s material type from filter photometry or spectroscopy and is not the subject of the present study. Object shape, on the other hand, can be revealed from a time-history of the object s brightness response. The most data-rich presentation is a continuous light-curve that records the object s brightness for an entire sensor pass, which could last for tens of minutes to several hours: from this one can see both short-term periodic behavior as well as brightness variations with phase angle. Light-curve interpretation, however, is more art than science and does not lend itself easily to automation; and the collection method, which requires single-object telescope dedication for long periods of time, is not well suited to debris survey conditions. So one is led to investigate how easily an object s brightness phase function, which can be constructed from the more survey-friendly point photometry, can be used to recover object shape. Such a recovery is usually attempted by comparing a phase-function curve constructed from an object s empirical brightness measurements to analytically-derived curves for basic shapes or shape combinations. There are two ways to accomplish this: a simple averaged brightness-versus phase curve assembled from the empirical data, or a more elaborate approach in which one is essentially calculating a brightness PDF for each phase angle bin (a technique explored in unpublished AFRL/RV research and in Ojakangas 2011); in each case the empirical curve is compared to analytical results for shapes of interest. The latter technique promises more discrimination power but requires more data; the

  8. Functioning of family system in pediatric oncology during treatment phase.

    Science.gov (United States)

    Perricone, Giovanna; Polizzi, Concetta; Morales, Maria Regina; Marino, Santo; Scacco, Cinzia Favara

    2012-10-01

    The study focuses on parents' psychological implications caused by the treatment of their children suffering from tumor. It investigates some specific mothers' resource factors such as their strategies of coping and the perception of their own family functioning in terms of cohesion and adaptability. The study was performed with 34 mothers of children suffering from acute lymphoblastic leukemia (ALL), during the treatment phase. The used tools were the Coping Orientation to Problem Experienced--New Italian Version, to investigate coping strategies, and the Family Adaptability and Cohesion Evaluation Scale-III, to analyze both real and ideal perception of family functioning. The data related to coping, show how the involved mothers tend to mainly use the strategies of positive aptitude, orientation toward problem and social support (F = 99.88, df = 4, P family functioning, in terms of adaptability, is described as chaotic relating to both the real (χ(2) = 13.29, df = 3, P = .004) and ideal (χ(2) = 11.52, df = 2, P = .003) family, whereas in terms of cohesion, it is perceived as chiefly disengaged in the real family (χ(2) = 12.3, df = 3, P = .006) and as enmeshed in the ideal one (χ(2) = 12.58, df = 3, P = .006). Statistically positive correlations were only detected between adaptability and avoidance (r = 0.49, P adaptability and orientation toward problem (r = 0.36, P adaptability and transcendent orientation (r = -0.04, P families and health care workers, so useful for the quality of childcare.

  9. Competing failure analysis in phased-mission systems with functional dependence in one of phases

    International Nuclear Information System (INIS)

    Wang, Chaonan; Xing, Liudong; Levitin, Gregory

    2012-01-01

    This paper proposes an algorithm for the reliability analysis of non-repairable phased-mission systems (PMS) subject to competing failure propagation and isolation effects. A failure originating from a system component which causes extensive damage to other system components is a propagated failure. When the propagated failure affects all the system components, causing the entire system failure, a propagated failure with global effect (PFGE) is said to occur. However, the failure propagation can be isolated in systems subject to functional dependence (FDEP) behavior, where the failure of a component (referred to as trigger component) causes some other components (referred to as dependent components) to become inaccessible or unusable (isolated from the system), and thus further failures from these dependent components have no effect on the system failure behavior. On the other hand, if any PFGE from dependent components occurs before the trigger failure, the failure propagation effect takes place, causing the overall system failure. In summary, there are two distinct consequences of a PFGE due to the competition between the failure isolation and failure propagation effects in the time domain. Existing works on such competing failures focus only on single-phase systems. However, many real-world systems are phased-mission systems (PMS), which involve multiple, consecutive and non-overlapping phases of operations or tasks. Consideration of competing failures for PMS is a challenging and difficult task because PMS exhibit dynamics in the system configuration and component behavior as well as statistical dependencies across phases for a given component. This paper proposes a combinatorial method to address the competing failure effects in the reliability analysis of binary non-repairable PMS. The proposed method is verified using a Markov-based method through a numerical example. Different from the Markov-based approach that is limited to exponential distribution, the

  10. Analytic properties of the Ruelle ζ-function for mean field models of phase transition

    International Nuclear Information System (INIS)

    Hallerberg, Sarah; Just, Wolfram; Radons, Guenter

    2005-01-01

    We evaluate by analytical means the Ruelle ζ-function for a spin model with global coupling. The implications of the ferromagnetic phase transitions for the analytical properties of the ζ-function are discussed in detail. In the paramagnetic phase the ζ-function develops a single branch point. In the low-temperature regime two branch points appear which correspond to the ferromagnetic state and the metastable state. The results are typical for any Ginsburg-Landau-type phase transition

  11. Phase-change memory functionality in gallium nanoparticles

    OpenAIRE

    Denisyuk, Andrey I.; Jonsson, Fredrik; Zheludev, Nikolay I.

    2007-01-01

    We report that the structural phase of gallium nanoparticles can be switched by optical excitation and read via their cathodoluminescence (CL) when excited by a scanning electron beam. This opens a new paradigm in developing high-density phase change optical memory elements. A film of gallium nanoparticles was sputtered at the end face of an optical fiber, through which the reflectivity at 195 K was monitored by a 1.31 µm laser. By launching a single pulse from a 1.55 µm laser (17 mW, 1 µs) t...

  12. Measurement of the amplitude and phase transfer functions of an optical modulator using a heterodyne technique

    DEFF Research Database (Denmark)

    Romstad, Francis Pascal; Birkedal, Dan; Mørk, Jesper

    2001-01-01

    We present a new technique that measures the full amplitude and phase transfer curves of the modulator as a function of the applied bias, from which the small signal α-parameter can be calculated. The technique measures the amplitude and phase transfer functions simultaneously and directly...

  13. Number-phase entropic uncertainty relations and Wigner functions for solvable quantum systems with discrete spectra

    Energy Technology Data Exchange (ETDEWEB)

    Honarasa, G.R., E-mail: honarasa@sutech.ac.i [Atomic and Molecular Group, Faculty of Physics, Yazd University, Yazd (Iran, Islamic Republic of); Tavassoly, M.K., E-mail: mktavassoly@yazduni.ac.i [Atomic and Molecular Group, Faculty of Physics, Yazd University, Yazd (Iran, Islamic Republic of); Hatami, M., E-mail: mhatami@yazduni.ac.i [Atomic and Molecular Group, Faculty of Physics, Yazd University, Yazd (Iran, Islamic Republic of)

    2009-10-19

    In this Letter, the 'number-phase entropic uncertainty relation' and the 'number-phase Wigner function' of generalized coherent states associated to a few solvable quantum systems with non-degenerate spectra are studied. We also investigate time evolution of 'number-phase entropic uncertainty' and 'Wigner function' of the considered physical systems with the help of temporally stable Gazeau-Klauder coherent states.

  14. Summer and winter time heterogeneity in aerosol single scattering albedo over the northwestern Atlantic Ocean during the TCAP field campaign: Relationship to chemical composition and mixing state

    Science.gov (United States)

    Berg, L. K.; Chand, D.; Fast, J. D.; Zelenyuk, A.; Wilson, J. M.; Sedlacek, A. J., III; Tomlinson, J. M.; Hubbe, J. M.; Comstock, J. M.; Mei, F.; Kassianov, E.; Schmid, B.

    2015-12-01

    Aerosol play crucial role in earth's radiative budget by scattering and absorbing solar radiation. The impact of aerosol on radiation budget depend on several factors including single scattering albedo (SSA), composition, and the growth processes, like coating or mixing. We describe findings relevant to optical properties of aerosol characterized over the Cape Cod and nearby northwest Atlantic Ocean during the Two Column Aerosol Project (TCAP) during the summer (July 2012) and winter (February 2013) campaigns. The average single scattering albedo (SSA) shows distinctly different vertical profiles during the summer and winter periods. During the summer study period, the average SSA is greater than 0.95 near surface, it increases to 0.97 until an altitude of 2.5 km, and then decreases to 0.94 at top of the column near 4 km. In contrast, during the winter study period the average SSA is less than 0.93 and decreases with height reaching an average value of 0.87 near the top of the column. The large difference in summer and winter time SSA is linked to the presence of biomass burning (BB) aerosol rather than black carbon or soot in both seasons. In our study, the BB on average is factor of two higher in free troposphere (FT) during summer and more than a factor of two higher in the boundary layer during winter. Single particle analysis indicates that the average profiles of refractory black carbon (rBC) mass are similar in both seasons. The average rBC size are similar at all altitudes sampled (0-4 km) in summer time but different during winter time. In addition, the particles sampled in the summertime FT appear to be more aged than those seen during winter. The observed large heterogeneity in SSA and its links to the particle coating and composition highlights the importance of aging and mixing processes of aerosol in this region and represents a challenge for both regional and global scale models.

  15. Optimized goniometer for determination of the scattering phase function of suspended particles: simulations and measurements.

    Science.gov (United States)

    Foschum, Florian; Kienle, Alwin

    2013-08-01

    We present simulations and measurements with an optimized goniometer for determination of the scattering phase function of suspended particles. We applied the Monte Carlo method, using a radially layered cylindrical geometry and mismatched boundary conditions, in order to investigate the influence of reflections caused by the interfaces of the glass cuvette and the scatterer concentration on the accurate determination of the scattering phase function. Based on these simulations we built an apparatus which allows direct measurement of the phase function from ϑ=7  deg to ϑ=172  deg without any need for correction algorithms. Goniometric measurements on polystyrene and SiO2 spheres proved this concept. Using the validated goniometer, we measured the phase function of yeast cells, demonstrating the improvement of the new system compared to standard goniometers. Furthermore, the scattering phase function of different fat emulsions, like Intralipid, was determined precisely.

  16. TOWARDS PHASE TRANSFERABLE POTENTIAL FUNCTIONS - METHODOLOGY AND APPLICATION TO NITROGEN

    NARCIS (Netherlands)

    JORDAN, PC; VAN MAAREN, PJ; MAVRI, J; VAN DER SPOEL, D; BERENDSEN, HJC

    1995-01-01

    We describe a generalizable approach to the development of phase transferable effective intermolecular potentials and apply the method to the study of N-2 The method is based on a polarizable shell model description of the isolated molecule and uses experimental data to establish the parameters.

  17. Calculation of metallic and insulating phases of V2O3 by hybrid density functionals

    Science.gov (United States)

    Guo, Yuzheng; Clark, Stewart J.; Robertson, John

    2014-02-01

    The electronic structure of vanadium sesquioxide V2O3 in its different phases has been calculated using the screened exchange hybrid density functional. The hybrid functional accurately reproduces the experimental electronic properties of all three phases, the paramagnetic metal (PM) phase, the anti-ferromagnetic insulating phase, and the Cr-doped paramagnetic insulating (PI) phase. We find that a fully relaxed supercell model of the Cr-doped PI phase based on the corundum structure has a monoclinic-like local strain around the substitutional Cr atoms. This is found to drive the PI-PM transition, consistent with a Peierls-Mott transition. The PI phase has a calculated band gap of 0.15 eV, in good agreement with experiment.

  18. In-Situ Monitoring of Immune Function, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Monitoring the health and wellness of mission pilots is a critically important function. Space flight has an adverse effect on the human immune response. During...

  19. Quantum mechanics on phase space: The hydrogen atom and its Wigner functions

    Science.gov (United States)

    Campos, P.; Martins, M. G. R.; Fernandes, M. C. B.; Vianna, J. D. M.

    2018-03-01

    Symplectic quantum mechanics (SQM) considers a non-commutative algebra of functions on a phase space Γ and an associated Hilbert space HΓ, to construct a unitary representation for the Galilei group. From this unitary representation the Schrödinger equation is rewritten in phase space variables and the Wigner function can be derived without the use of the Liouville-von Neumann equation. In this article the Coulomb potential in three dimensions (3D) is resolved completely by using the phase space Schrödinger equation. The Kustaanheimo-Stiefel(KS) transformation is applied and the Coulomb and harmonic oscillator potentials are connected. In this context we determine the energy levels, the amplitude of probability in phase space and correspondent Wigner quasi-distribution functions of the 3D-hydrogen atom described by Schrödinger equation in phase space.

  20. Determination of drift-flux velocity as a function of two-phase flow patterns

    International Nuclear Information System (INIS)

    Austregesilo Filho, H.

    1986-01-01

    A method is suggested for the calculation of drift-flux velocity as a function of two-phase flow patterns determined analytically. This model can be introduced in computer codes for thermal hydraulic analyses based mainly on homogeneous assumptions, in order to achieve a more realis tic description of two-phase flow phenomena, which is needed for the simulation of accidents in nuclear power plants for which phase separation effects are dominant, e.g., small break accidents. (Author) [pt

  1. Continental pollution in the Western Mediterranean basin: large variability of the aerosol single scattering albedo and influence on the direct shortwave radiative effect

    Directory of Open Access Journals (Sweden)

    C. Di Biagio

    2016-08-01

    Full Text Available Pollution aerosols strongly influence the composition of the Western Mediterranean basin, but at present little is known on their optical properties. We report in this study in situ observations of the single scattering albedo (ω of pollution aerosol plumes measured over the Western Mediterranean basin during the TRAQA (TRansport and Air QuAlity airborne campaign in summer 2012. Cases of pollution export from different source regions around the basin and at different altitudes between  ∼  160 and 3500 m above sea level were sampled during the flights. Data from this study show a large variability of ω, with values between 0.84–0.98 at 370 nm and 0.70–0.99 at 950 nm. The single scattering albedo generally decreases with the wavelength, with some exception associated to the mixing of pollution with sea spray or dust particles over the sea surface. The lowest values of ω (0.84–0.70 between 370 and 950 nm are measured in correspondence of a fresh plume possibly linked to ship emissions over the basin. The range of variability of ω observed in this study seems to be independent of the source region around the basin, as well as of the altitude and aging time of the plumes. The observed variability of ω reflects in a large variability for the complex refractive index of pollution aerosols, which is estimated to span in the large range 1.41–1.77 and 0.002–0.097 for the real and the imaginary parts, respectively, between 370 and 950 nm. Radiative calculations in clear-sky conditions were performed with the GAME radiative transfer model to test the sensitivity of the aerosol shortwave Direct Radiative Effect (DRE to the variability of ω as observed in this study. Results from the calculations suggest up to a 50 and 30 % change of the forcing efficiency (FE, i.e. the DRE per unit of optical depth, at the surface (−160/−235 W m−2 τ−1 at 60° solar zenith angle and at the Top-Of-Atmosphere (−137/−92

  2. Multi Function and High Power Amplifier Chipset for X-Band Phased Array Frontends

    NARCIS (Netherlands)

    Heijningen, M. van; Boer, A. de; Hoogland, J.A.; Wanum, M. van; Hek, A.P. de; Vliet, F.E. van; Brouzes, H.

    2006-01-01

    This paper presents the design and measurement results of two MMICs for X-band phased array applications: a Multi Function Chip (MFC) and High Power Amplifier (HPA). The fully integrated MFC combines the phase and attenuation setting, Transmit/Receive (T/R) switching, Low Noise Amplifier and Driver

  3. Object performance as a function of pileup density for CMS PhaseII

    CERN Document Server

    CMS Collaboration

    2017-01-01

    This document collects the performance of physics objects (electrons, muons, taus, jets, MET) reconstructed with the CMS Phase-2 upgraded detector as a function of the pileup density for the High Luminosity LHC environment of 200 PU.

  4. Dielectric function of two-phase colloid-polymer nanocomposite.

    Science.gov (United States)

    Mitzscherling, S; Cui, Q; Koopman, W; Bargheer, M

    2015-11-28

    The plasmon resonance of metal nanoparticles determines their optical response in the visible spectral range. Many details such as the electronic properties of gold near the particle surface and the local environment of the particles influence the spectra. We show how the cheap but highly precise fabrication of composite nanolayers by spin-assisted layer-by-layer deposition of polyelectrolytes can be used to investigate the spectral response of gold nanospheres (GNS) and gold nanorods (GNR) in a self-consistent way, using the established Maxwell-Garnett effective medium (MGEM) theory beyond the limit of homogeneous media. We show that the dielectric function of gold nanoparticles differs from the bulk value and experimentally characterize the shape and the surrounding of the particles thoroughly by SEM, AFM and ellipsometry. Averaging the dielectric functions of the layered surrounding by an appropriate weighting with the electric field intensity yields excellent agreement for the spectra of several nanoparticles and nanorods with various cover-layer thicknesses.

  5. Respiratory functions in asthmatic and normal women during different phases of menstrual cycle

    International Nuclear Information System (INIS)

    Arora, D.B.; Sandhu, P.K.; Dhillon, S.; Arora, A.

    2015-01-01

    Menstrual cycle is an integral part of life of women. There is widespread agreement that changes in the levels of oestrogen and progesterone associated with menstrual cycle also affect different systems of the body besides reproductive system. Levels of oestrogen and progesterone are maximum in the secretory phase and minimum just before the menstruation .Bronchial asthma is one of the commonest chronic respiratory diseases. Premenstrual worsening of asthma symptoms has been reported to affect 33-40% of asthmatic women. This exacerbation of asthma symptoms has been correlated with the oestrogen and progesterone levels. The association between menstrual cycle and lung functions in normal females has also been recognised. The pathophysiology of this process is still not proved. The purpose of our study was to confirm the probable effects of the female hormones on lung functions in normal and asthmatic women in different phases of menstrual cycle and to compare them. Methods: The study was done on 40 normal and 40 asthmatic females in the age group of 15-45 years. Pulmonary function tests were done in three phases of menstrual cycle i.e. follicular, secretory and menstrual in all the subjects. Results: The mean value of lung functions, i.e., FVC, FEV, PEFR, FEF25-75%, FEF 200-1200 were significantly lower in asthmatic females than normal ones (p<0.01) in all three phases. The lung functions of both asthmatic and non-asthmatic females in secretory phase were significantly higher than in menstrual phase (p<0.005). The PFTs in menstrual phase were even lower than the follicular phase (p<0.04). Conclusion: Respiratory parameters of both asthmatic and non-asthmatic women in reproductive age group show significant variation in different phases of menstrual cycle. The smooth muscle relaxant effect of progesterone and probably oestrogen might have contributed to it. The lung function parameters in asthmatics were of lower value compared to normal women. (author)

  6. Circadian phase preference in college students: relationships with psychological functioning and academics.

    Science.gov (United States)

    Taylor, Daniel J; Clay, Kendra C; Bramoweth, Adam D; Sethi, Kevin; Roane, Brandy M

    2011-07-01

    The current study offers a comprehensive assessment of psychosocial functioning and academic performance in relation to circadian phase preference in a US sample of undergraduate college students (N = 838), aged 17-26 (M = 19.78, SD = 1.89). Women had greater morning preference than men, and seniors had greater morning preference than freshmen. Circadian phase preference, fatigue, perceived stress, depression, anxiety, and substance use were assessed cross-sectionally and grade point average (GPA) was assessed prospectively. Evening phase preference was related to higher levels of fatigue, alcohol and caffeine use, and worse academic performance than morning or intermediate phase preferences.

  7. First order magneto-structural phase transition and associated multi-functional properties in magnetic solids

    International Nuclear Information System (INIS)

    Roy, Sindhunil Barman

    2013-01-01

    We show that the first order magneto-structural phase transitions observed in various classes of magnetic solids are often accompanied by useful multi-functional properties, namely giant magneto-resistance, magneto-caloric effect and magneto-striction. We highlight various characteristic features associated with a disorder influenced first order phase transition namely supercooling, superheating, phase-coexistence and metastability, in several magnetic materials and discuss how a proper understanding of the transition process can help in fine tuning of the accompanied functional properties. Magneto-elastic coupling is a key element in this first order phase transition, and methods need to be explored for maximizing the contributions from both the lattice and the magnetic degree of freedom while simultaneously minimizing the thermomagnetic hysteresis loss. An analogy is also drawn with the first order phase transition observed in dielectric materials and vortex matter of type-II superconductors. (topical review)

  8. First order magneto-structural phase transition and associated multi-functional properties in magnetic solids.

    Science.gov (United States)

    Roy, Sindhunil Barman

    2013-05-08

    We show that the first order magneto-structural phase transitions observed in various classes of magnetic solids are often accompanied by useful multi-functional properties, namely giant magneto-resistance, magneto-caloric effect and magneto-striction. We highlight various characteristic features associated with a disorder influenced first order phase transition namely supercooling, superheating, phase-coexistence and metastability, in several magnetic materials and discuss how a proper understanding of the transition process can help in fine tuning of the accompanied functional properties. Magneto-elastic coupling is a key element in this first order phase transition, and methods need to be explored for maximizing the contributions from both the lattice and the magnetic degree of freedom while simultaneously minimizing the thermomagnetic hysteresis loss. An analogy is also drawn with the first order phase transition observed in dielectric materials and vortex matter of type-II superconductors.

  9. Small airway function changes and its clinical significance of asthma patients in different clinical phases

    Directory of Open Access Journals (Sweden)

    Yan-Hui Zhou

    2016-11-01

    Full Text Available Objective: To observe the small airways function changes of asthmatic patients in different clinical phases and to discuss its clinical significance. Methods: A total of 127 patients diagnosed as asthma were selected randomly and pulmonary function (PF of them was determined by conventional method. Then they were divided into A, B and C group based on PF results. All 34 patients in A group suffered from acute asthma attack for the first time. All 93 patients in B group had been diagnosed as asthma but in remission phase. C Group was regarded as Control group with 20 healthy volunteers. Then FEV1, FEF50%, FEF75% levels of patients in each group were analyzed, and ΔFEV1, ΔFEF75% and ΔFEF50% levels of patients in each group were compared after bronchial dilation test. Results: It was found that most patients in group A and B had abnormal small airways function, and their small airways function was significantly different compared with that of group C (P<0.01. In addition, except for group C, ΔFEF75%,ΔFEF50% levels in A and B group were improved more significantly than ΔFEV1 levels (P<0.01. Conclusions: Asthma patients in acute phase all have abnormal small airways function. Most asthma patients in remission phase also have abnormal small airways function. After bronchial dilation test, whether patients in acute phase or in remission phase, major and small airways function of them are improved, but improvement of small airways function is weaker than that of major airways. This indicates that asthma respiratory tract symptoms in different phases exists all the time and so therapeutic process is needed to perform step by step.

  10. Why the Heyd-Scuseria-Ernzerhof hybrid functional description of VO2 phases is not correct

    KAUST Repository

    Grau-Crespo, Ricardo

    2012-08-06

    In contrast with recent claims that the Heyd-Scuseria-Ernzerhof (HSE) screened hybrid functional can provide a good description of the electronic and magnetic structures of VO2 phases, we show here that the HSE lowest-energy solutions for both the low-temperature monoclinic (M1) phase and the high-temperature rutile (R) phase, which are obtained upon inclusion of spin polarization, are at odds with experimental observations. For the M1 phase the ground state is (but should not be) magnetic, while the ground state of the R phase, which is also spin polarized, is not (but should be) metallic. The energy difference between the low-temperature and high-temperature phases has strong discrepancies with the experimental latent heat.

  11. On the use of functional calculus for phase-type and related distributions

    DEFF Research Database (Denmark)

    Bladt, Mogens; Campillo Navarro, Azucena; Nielsen, Bo Friis

    of matrices. Functional calculus, which is a branch of operator theory frequently associated with complex analysis, can be applied to phase-type and matrix-exponential distributions in a rather straightforward way. In this paper we provide a number of examples on how to execute the formal arguments.......The area of phase-type distributions is renowned for its ability to obtain closed form formulas or algorithmically exact solutions to many complex stochastic models. The method of functional calculus will provide an additional tool along these lines for establishing results in terms of functions...

  12. On the use of functional calculus for phase-type and related distributions

    DEFF Research Database (Denmark)

    Bladt, Mogens; Navarro, Azucena Campillo; Nielsen, Bo Friis

    2016-01-01

    The area of phase-type distributions is renowned for its ability to obtain closed form formulas or algorithmically exact solutions to many complex stochastic models. The method of functional calculus will provide an additional tool along these lines for establishing results in terms of functions...... of matrices. Functional calculus, which is a branch of operator theory frequently associated with complex analysis, can be applied to phase-type and matrix-exponential distributions in a rather straightforward way. In this article we provide a number of examples of how to execute the formal arguments....

  13. Using the Aerosol Single Scattering Albedo and Angstrom Exponent from AERONET to Determine Aerosol Origins and Mixing States over the Indo-Gangetic Plain

    Science.gov (United States)

    Giles, D. M.; Holben, B. N.; Eck, T. F.; Sinyuk, A.; Slutsker, I.; Smirnov, A.; Schafer, J. S.; Dickerson, R. R.; Thompson, A. M.; Tripathi, S. N.; Singh, R. P.; Ghauri, B.

    2012-12-01

    Aerosol mixtures—whether dominated by dust, carbon, sulfates, nitrates, sea salt, or mixtures of them—complicate the retrieval of remotely sensed aerosol properties from satellites and possibly increase the uncertainty of the aerosol radiative impact on climate. Major aerosol source regions in South Asia include the Thar Desert as well as agricultural lands, Himalayan foothills, and large urban centers in and near the Indo-Gangetic Plain (IGP). Over India and Pakistan, seasonal changes in meteorology, including the monsoon (June-September), significantly affect the transport, lifetime, and type of aerosols. Strong monsoonal winds can promote long range transport of dust resulting in mixtures of dust and carbonaceous aerosols, while more stagnant synoptic conditions (e.g., November-January) can prolong the occurrence of urban/industrial pollution, biomass burning smoke, or mixtures of them over the IGP. Aerosol Robotic Network (AERONET) Sun/sky radiometer data are analyzed to show the aerosol optical depth (AOD) seasonality and aerosol dominant mixing states. The Single Scattering Albedo (SSA) and extinction Angstrom exponent (EAE) relationship has been shown to provide sound clustering of dominant aerosol types using long term AERONET site data near known source regions [Giles et al., 2012]. In this study, aerosol type partitioning using the SSA (440 nm) and EAE (440-870 nm) relationship is further developed to quantify the occurrence of Dust, Mixed (e.g., dust and carbonaceous aerosols), Urban/Industrial (U/I) pollution, and Biomass Burning (BB) smoke. Based on EAE thresholds derived from the cluster analysis (for AOD440nm>0.4), preliminary results (2001-2010) for Kanpur, India, show the overall contributions of each dominant particle type (rounded to the nearest 10%): 10% for Dust (EAE≤0.25), 60% for Mixed (0.251.25). In the IGP, BB aerosols may have varying sizes (e.g., corresponding to 1.2India and Pakistan are also analyzed using available AERONET

  14. Influence of soot mixing state on aerosol light absorption and single scattering albedo during air mass aging at a polluted regional site in northeastern China

    Science.gov (United States)

    Cheng, Y. F.; Berghof, M.; Garland, R. M.; Wiedensohler, A.; Wehner, B.; Müller, T.; Su, H.; Zhang, Y. H.; Achtert, P.; Nowak, A.; PöSchl, U.; Zhu, T.; Hu, M.; Zeng, L. M.

    2009-01-01

    An aerosol optical closure study was performed using the observed high time- and size-resolved soot mixing states determined by a Volatility Tandem Differential Mobility Analyzer (VTDMA) at a polluted regional site, Yufa, in the south of Beijing during the summer of 2006. Good agreement was found between the simulated and measured aerosol absorption (σap, R = 0.9) and scattering (σsp, R ≥ 0.95). The soot mixing state at Yufa can be generally determined by VTDMA, in terms of properly predicting the σap using a simple optical model combined with spherical homogeneous and core-shell coated Mie codes. The possible uncertainties in the modeled σap were discussed. Rapid soot aging was observed, which led to large variations in the fractional contributions to σap by externally mixed and coated soot. On average, about 37% of the σap (˜10-60%) arose by the coated soot. The coating enhancement in σap and σsp of the coated soot can reach up to a factor of 8-10 within several hours owing to the secondary processing during daytime. It was contributed not only by the increased thickness of coating shell, but also the transition of soot from externally mixed to coated one. Hence, assuming constant soot mixing state for the regional climate model is not realistic and may lead to uncertainties. In the highly polluted region in northeastern China, the aerosol single scattering albedo may increase very fast owing to the rapid secondary particle formation and condensation (up to 0.90-0.95). This increase took place although the concurrent coating processing enhanced the light absorption capability of soot.

  15. Functional design criteria for project W-252, phase II liquid effluent treatment and disposal. Revision 2

    International Nuclear Information System (INIS)

    Hatch, C.E.

    1995-05-01

    This document is the Functional Design Criteria for Project W-252. Project W-252 provides the scope to provide BAT/AKART (best available technology...) to 200 Liquid Effluent Phase II streams (B-Plant). This revision (Rev. 2) incorporates a major descoping of the project. The descoping was done to reflect a combination of budget cutting measures allowed by a less stringent regulatory posture toward the Phase II streams

  16. Competing failure analysis in phased-mission systems with multiple functional dependence groups

    International Nuclear Information System (INIS)

    Wang, Chaonan; Xing, Liudong; Peng, Rui; Pan, Zhusheng

    2017-01-01

    A phased-mission system (PMS) involves multiple, consecutive, non-overlapping phases of operation. The system structure function and component failure behavior in a PMS can change from phase to phase, posing big challenges to the system reliability analysis. Further complicating the problem is the functional dependence (FDEP) behavior where the failure of certain component(s) causes other component(s) to become unusable or inaccessible or isolated. Previous studies have shown that FDEP can cause competitions between failure propagation and failure isolation in the time domain. While such competing failure effects have been well addressed in single-phase systems, only little work has focused on PMSs with a restrictive assumption that a single FDEP group exists in one phase of the mission. Many practical systems (e.g., computer systems and networks), however may involve multiple FDEP groups during the mission. Moreover, different FDEP groups can be dependent due to sharing some common components; they may appear in a single phase or multiple phases. This paper makes new contributions by modeling and analyzing reliability of PMSs subject to multiple FDEP groups through a Markov chain-based methodology. Propagated failures with both global and selective effects are considered. Four case studies are presented to demonstrate application of the proposed method. - Highlights: • Reliability of phased-mission systems subject to competing failure propagation and isolation effects is modeled. • Multiple independent or dependent functional dependence groups are considered. • Propagated failures with global effects and selective effects are studied. • Four case studies demonstrate generality and application of the proposed Markov-based method.

  17. Measurements of betatron phase advance and beta function in the ISR

    International Nuclear Information System (INIS)

    Borer, J.; Hofmann, A.; Koutchouk, J.P.; Risselada, T.; Zotter, B.

    1983-01-01

    To check the optics of large storage rings measurements of the lattice functions are important. Some of these measurement methods have been tried out in the ISR. Information about the optics all round the ring is obtained by exciting a continuous betatron oscillation. The responses of different position monitors are compared with a network analyser. The square of the observed amplitude gives directly the relative value of the beta function. By measuring the relative phase of the responses the betatron phase advance between the locations of the monitors is obtained. Most of the error introduced by cable lengths is eliminated by observing both the upper and lower betatron side bands. The phase measurement does not depend on the monitor calibration. Its accuracy is therefore quite good as is confirmed by comparing the results with computations. Near the low-beta insertion, the beta functions are measured by observing the variation of the tune with changing quadrupole excitation

  18. Functional Super Read Out Driver Demonstrator for the Phase II Upgrade of the ATLAS Tile Calorimeter

    CERN Document Server

    Carrió, F; The ATLAS collaboration; Ferrer, A; Fiorini, L; González, V; Hernández, Y; Higón, E; Moreno, P; Sanchis, E; Solans, C; Valero, A; Valls, J

    2011-01-01

    This work presents the implementation of a functional super Read Out Driver (sROD) demonstrator for the Phase II Upgrade of the ATLAS Tile Calorimeter (TileCal) in the LHC experiment. The proposed front-end for the Phase II Upgrade communicates with back-end electronics using a multifiber optical connector with a data rate of 57.6 Gbps using the GBT protocol. This functional sROD demonstrator aims to help in the understanding of the problems that could arise in the upgrade of back-end electronics. The demonstrator is composed of three different boards that have been developed in the framework of ATLAS activities: the Optical Multiplexer Board (OMB), the Read-Out Driver (ROD) and the Optical Link Card (OLC). This functional sROD demonstrator will be used to develop a prototype, in ATCA format, of the new ROD for the Phase II.

  19. Wavefield iterative deconvolution to remove multiples and produce phase specific Ps receiver functions

    Science.gov (United States)

    Ainiwaer, A.; Gurrola, H.

    2018-03-01

    Common conversion point stacking or migration of receiver functions (RFs) and H-k (H is depth and k is Vp/Vs) stacking of RFs has become a common method to study the crust and upper mantle beneath broad-band three-component seismic stations. However, it can be difficult to interpret Pds RFs due to interference between the Pds, PPds and PSds phases, especially in the mantle portion of the lithosphere. We propose a phase separation method to isolate the prominent phases of the RFs and produce separate Pds, PPds and PSds `phase specific' receiver functions (referred to as PdsRFs, PPdsRFs and PSdsRFs, respectively) by deconvolution of the wavefield rather than single seismograms. One of the most important products of this deconvolution method is to produce Ps receiver functions (PdsRFs) that are free of crustal multiples. This is accomplished by using H-k analysis to identify specific phases in the wavefield from all seismograms recorded at a station which enables development of an iterative deconvolution procedure to produce the above-mentioned phase specific RFs. We refer to this method as wavefield iterative deconvolution (WID). The WID method differentiates and isolates different RF phases by exploiting their differences in moveout curves across the entire wave front. We tested the WID by applying it to synthetic seismograms produced using a modified version of the PREM velocity model. The WID effectively separates phases from each stacked RF in synthetic data. We also applied this technique to produce RFs from seismograms recorded at ARU (a broad-band station in Arti, Russia). The phase specific RFs produced using WID are easier to interpret than traditional RFs. The PdsRFs computed using WID are the most improved, owing to the distinct shape of its moveout curves as compared to the moveout curves for the PPds and PSds phases. The importance of this WID method is most significant in reducing interference between phases for depths of less than 300 km. Phases from

  20. Comment on "Wigner phase-space distribution function for the hydrogen atom"

    DEFF Research Database (Denmark)

    Dahl, Jens Peder; Springborg, Michael

    1999-01-01

    We object to the proposal that the mapping of the three-dimensional hydrogen atom into a four-dimensional harmonic oscillator can be readily used to determine the Wigner phase-space distribution function for the hydrogen atom. [S1050-2947(99)07005-5].......We object to the proposal that the mapping of the three-dimensional hydrogen atom into a four-dimensional harmonic oscillator can be readily used to determine the Wigner phase-space distribution function for the hydrogen atom. [S1050-2947(99)07005-5]....

  1. Phase function measurements on nonspherical scatterers using a two-axis goniometer.

    Science.gov (United States)

    Forster, Florian Klaus; Kienle, Alwin; Michels, Rene; Hibst, Raimund

    2006-01-01

    We present a two-axis goniometer for measuring the phase function of scattering media with an angular resolution of about 0.2 deg having 12 decades of dynamic range and covering almost the full solid angle. The setup is evaluated with polystyrene spheres and with perpendicularly and obliquely illuminated thin glass cylinders. The scattering pattern and its intensity distribution are in excellent agreement with analytical theory. A multiple scattering configuration composed of two parallel cylinders is also examined. Finally, the phase function of dentin slabs is measured and its dependence on the dental microstructure is discussed.

  2. Chord-length distribution function for two-phase random media

    International Nuclear Information System (INIS)

    Torquato, S.; Lu, B.

    1993-01-01

    A statistical correlation function of basic importance in the study of two-phase random media (such as suspensions, porous media, and composites) is the chord-length distribution function p(z). We show that p(z) is related to another fundamentally important morphological descriptor studied by us previously, namely, the lineal-path function L(z), which gives the probability of finding a line segment of length z wholly in one of the phases when randomly thrown into the sample. We derive exact series representations of the chord-length distribution function for media comprised of spheres with a polydispersivity in size for arbitrary space dimension D. For the special case of spatially uncorrelated spheres (i.e., fully penetrable spheres), we determine exactly p(z) and the mean chord length l C , the first moment of p(z). We also obtain corresponding formulas for the case of impenetrable (i.e., spatially correlated) polydispersed spheres

  3. Adjoint method provides phase response functions for delay-induced oscillations.

    Science.gov (United States)

    Kotani, Kiyoshi; Yamaguchi, Ikuhiro; Ogawa, Yutaro; Jimbo, Yasuhiko; Nakao, Hiroya; Ermentrout, G Bard

    2012-07-27

    Limit-cycle oscillations induced by time delay are widely observed in various systems, but a systematic phase-reduction theory for them has yet to be developed. Here we present a practical theoretical framework to calculate the phase response function Z(θ), a fundamental quantity for the theory, of delay-induced limit cycles with infinite-dimensional phase space. We show that Z(θ) can be obtained as a zero eigenfunction of the adjoint equation associated with an appropriate bilinear form for the delay differential equations. We confirm the validity of the proposed framework for two biological oscillators and demonstrate that the derived phase equation predicts intriguing multimodal locking behavior.

  4. Density functional simulations of Sb-rich GeSbTe phase change alloys

    Science.gov (United States)

    Gabardi, S.; Caravati, S.; Bernasconi, M.; Parrinello, M.

    2012-09-01

    We generated models of the amorphous phase of Sb-rich GeSbTe phase change alloys by quenching from the melt within density functional molecular dynamics. We considered the two compositions Ge1Sb1Te1 and Ge2Sb4Te5. Comparison with previous results on the most studied Ge2Sb2Te5 allowed us to draw some conclusions on the dependence of the structural properties of the amorphous phase on the alloy composition. Vibrational and electronic properties were also scrutinized. Phonons at high frequencies above 200 cm-1 are localized in tetrahedra around Ge atoms in Sb-rich compounds as well as in Ge2Sb2Te5. All compounds are semiconducting in the amorphous phase, with a band gap in the range 0.7-1.0 eV.

  5. Radial distribution function imaging by STEM diffraction: Phase mapping and analysis of heterogeneous nanostructured glasses

    Energy Technology Data Exchange (ETDEWEB)

    Mu, Xiaoke, E-mail: muxiaoke@gmail.com [Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); Helmholtz-Institute Ulm for Electrochemical Energy Storage (HIU), Karlsruhe Institute of Technology (KIT), 89081 Ulm (Germany); Wang, Di [Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); Feng, Tao [Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology (NJUST), 210094 Nanjing (China); Kübel, Christian [Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); Helmholtz-Institute Ulm for Electrochemical Energy Storage (HIU), Karlsruhe Institute of Technology (KIT), 89081 Ulm (Germany); Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany)

    2016-09-15

    Characterizing heterogeneous nanostructured amorphous materials is a challenging topic, because of difficulty to solve disordered atomic arrangement in nanometer scale. We developed a new transmission electron microscopy (TEM) method to enable phase analysis and mapping of heterogeneous amorphous structures. That is to combine scanning TEM (STEM) diffraction mapping, radial distribution function (RDF) analysis, and hyperspectral analysis. This method was applied to an amorphous zirconium oxide and zirconium iron multilayer system, and showed extreme sensitivity to small atomic packing variations. This approach helps to understand local structure variations in glassy composite materials and provides new insights to correlate structure and properties of glasses. - Highlights: • A method for phase mapping of nanostructured amorphous materials was developed. • The phase mapping is purely based on structural information. • The method combines STEM diffraction with radial distribution function analysis. • The method was applied on an amorphous multilayer for demonstrating its sensitivity.

  6. Parameterization of single-scattering albedo (SSA) and absorption Ångström exponent (AAE) with EC / OC for aerosol emissions from biomass burning

    Science.gov (United States)

    Pokhrel, Rudra P.; Wagner, Nick L.; Langridge, Justin M.; Lack, Daniel A.; Jayarathne, Thilina; Stone, Elizabeth A.; Stockwell, Chelsea E.; Yokelson, Robert J.; Murphy, Shane M.

    2016-08-01

    Single-scattering albedo (SSA) and absorption Ångström exponent (AAE) are two critical parameters in determining the impact of absorbing aerosol on the Earth's radiative balance. Aerosol emitted by biomass burning represent a significant fraction of absorbing aerosol globally, but it remains difficult to accurately predict SSA and AAE for biomass burning aerosol. Black carbon (BC), brown carbon (BrC), and non-absorbing coatings all make substantial contributions to the absorption coefficient of biomass burning aerosol. SSA and AAE cannot be directly predicted based on fuel type because they depend strongly on burn conditions. It has been suggested that SSA can be effectively parameterized via the modified combustion efficiency (MCE) of a biomass burning event and that this would be useful because emission factors for CO and CO2, from which MCE can be calculated, are available for a large number of fuels. Here we demonstrate, with data from the FLAME-4 experiment, that for a wide variety of globally relevant biomass fuels, over a range of combustion conditions, parameterizations of SSA and AAE based on the elemental carbon (EC) to organic carbon (OC) mass ratio are quantitatively superior to parameterizations based on MCE. We show that the EC / OC ratio and the ratio of EC / (EC + OC) both have significantly better correlations with SSA than MCE. Furthermore, the relationship of EC / (EC + OC) with SSA is linear. These improved parameterizations are significant because, similar to MCE, emission factors for EC (or black carbon) and OC are available for a wide range of biomass fuels. Fitting SSA with MCE yields correlation coefficients (Pearson's r) of ˜ 0.65 at the visible wavelengths of 405, 532, and 660 nm while fitting SSA with EC / OC or EC / (EC + OC) yields a Pearson's r of 0.94-0.97 at these same wavelengths. The strong correlation coefficient at 405 nm (r = 0.97) suggests that parameterizations based on EC / OC or EC / (EC + OC) have good predictive

  7. Determination of the single scattering albedo and direct radiative forcing of biomass burning aerosol with data from the MODIS (Moderate Resolution Imaging Spectroradiometer) satellite instrument

    Science.gov (United States)

    Zhu, Li

    Biomass burning aerosols absorb and scatter solar radiation and therefore affect the energy balance of the Earth-atmosphere system. The single scattering albedo (SSA), the ratio of the scattering coefficient to the extinction coefficient, is an important parameter to describe the optical properties of aerosols and to determine the effect of aerosols on the energy balance of the planet and climate. Aerosol effects on radiation also depend strongly on surface albedo. Large uncertainties remain in current estimates of radiative impacts of biomass burning aerosols, due largely to the lack of reliable measurements of aerosol and surface properties. In this work we investigate how satellite measurements can be used to estimate the direct radiative forcing of biomass burning aerosols. We developed a method using the critical reflectance technique to retrieve SSA from the Moderate Resolution Imaging Spectroradiometer (MODIS) observed reflectance at the top of the atmosphere (TOA). We evaluated MODIS retrieved SSAs with AErosol RObotic NETwork (AERONET) retrievals and found good agreements within the published uncertainty of the AERONET retrievals. We then developed an algorithm, the MODIS Enhanced Vegetation Albedo (MEVA), to improve the representations of spectral variations of vegetation surface albedo based on MODIS observations at the discrete 0.67, 0.86, 0.47, 0.55, 1.24, 1.64, and 2.12 mu-m channels. This algorithm is validated using laboratory measurements of the different vegetation types from the Amazon region, data from the Johns Hopkins University (JHU) spectral library, and data from the U.S. Geological Survey (USGS) digital spectral library. We show that the MEVA method can improve the accuracy of flux and aerosol forcing calculations at the TOA compared to more traditional interpolated approaches. Lastly, we combine the MODIS retrieved biomass burning aerosol SSA and the surface albedo spectrum determined from the MEVA technique to calculate TOA flux and

  8. Heterodyne technique for measuring the amplitude and phase transfer functions of an optical modulator

    DEFF Research Database (Denmark)

    Romstad, Francis Pascal; Birkedal, Dan; Mørk, Jesper

    2002-01-01

    In this letter, we propose a technique based on heterodyne detection for accurately and simultaneously measuring the amplitude and phase transfer functions of an optical modulator. The technique is used to characterize an InGaAsp multiple quantum-well electroabsorption modulator. From...

  9. Phase representation of quantum-optical systems via nonnegative quantum distribution function

    International Nuclear Information System (INIS)

    Chizhov, A.V.; Gusev, A.A.; Vinitskij, S.I.; Sevast'yanov, L.A.

    2007-01-01

    We propose a new method for describing phase distributions of nonclassical states in optical systems based on the nonnegative quantum distribution function. A comparison of the proposed method with other known methods such as the Pegg-Barnett and operational ones is given

  10. Mobility function of a prosthetic knee joint with an automatic stance phase lock.

    Science.gov (United States)

    Andrysek, Jan; Klejman, Susan; Torres-Moreno, Ricardo; Heim, Winfried; Steinnagel, Bryan; Glasford, Shane

    2011-06-01

    There is a need for a prosthetic knee joint design that is technologically and functionally appropriate for use in developing countries. To develop and clinically evaluate a new type of stance phase controlled prosthetic knee joint that provides stance phase stability without inhibiting swing phase flexion. A crossover repeated measures study design comparing the new knee joint to the participant's conventional low- or high-end prosthetic knee joint. The new knee joint was fitted to fourteen individuals aged 15 to 67 years with unilateral lower limb amputations. Walk tests were performed to measure walking speed. Energy expenditure was estimated using the physiological cost index (PCI). Walking speeds with the new knee joint were on average 0.14 m/s faster than conventional low-end knees (p < 0.0001), but 0.07 m/s slower than conventional high-end prosthetic knees (p = 0.008). The PCI was similar across all three knee joint technologies (p = 0.276). Mobility function with the new knee joint, in terms of walking speed, was more closely matched to high-end than low-end prosthetic knee joints. Therefore, given its relatively simple design, the new stance phase control mechanism may offer a functional and cost effective solution for active transfemoral amputees. This paper describes a new type of prosthetic knee joint mechanism that is intended to be cost-effective while providing high-level stance phase function to active individuals with a transfemoral amputation. Initial clinical testing suggests that the new knee joint may have some functional advantages over existing technologies in this category.

  11. The exergy of a phase shift: Ecosystem functioning loss in seagrass meadows of the Mediterranean Sea

    Science.gov (United States)

    Montefalcone, Monica; Vassallo, Paolo; Gatti, Giulia; Parravicini, Valeriano; Paoli, Chiara; Morri, Carla; Bianchi, Carlo Nike

    2015-04-01

    Sustained functioning of ecosystems is predicted to depend upon the maintenance of their biodiversity, structure and integrity. The large consensus achieved in this regard, however, faces to the objective difficulty of finding appropriate metrics to measure ecosystem functioning. Here, we aim at evaluating functional consequence of the phase shift occurring in meadows of the Mediterranean seagrass Posidonia oceanica, a priority habitat that is undergoing regression in many coastal areas due to multiple human pressures. Structural degradation of the P. oceanica ecosystem, consequent to increasing coastal exploitation and climate change, may result in the progressive replacement of this seagrass by opportunistic macrophytes, either native or alien. Reviewing published information and our personal records, we measured changes in biological habitat provisioning, species richness and biomass associated to each of the alternative states characterizing the phase shift. Then, ecosystem functioning was assessed by computing the exergy associated to each state, exergy being a state variable that measures the ecosystem capacity to produce work. Phase shift was consistently shown to imply loss in habitat provision, species richness, and biomass; structural and compositional loss was parallelled by a reduction of exergy content, thus providing for the first time an objective and integrative measure of the loss of ecosystem functioning following the degradation of healthy seagrass meadows.

  12. Bidirectional reflectance spectroscopy 7. The single particle phase function hockey stick relation

    Science.gov (United States)

    Hapke, Bruce

    2012-11-01

    The measured volume-average single particle angular scattering functions of a large number of types of particle of interest for planetary regoliths in the visible-near-IR wavelength region can be represented to a reasonable approximation by two-parameter, double Henyey-Greenstein functions. When the two parameters of this function are plotted against one another they are found to be inversely correlated and lie within a restricted zone shaped like a hockey stick within the parameter space. The centroid of the zone is a curve that can be represented by a simple empirical equation. The wide variety of types of particles used to construct the plot implies that this equation may represent most of the particles found in regoliths. This means that when modeling the bidirectional reflectance of a regolith it may be possible to reduce the number of parameters necessary to specify the reflectance, and also to characterize the entire single particle phase function from observations at phase angles less than 90°. Even if the hockey stick relation has a finite width, rather than being a line, it restricts the parameter space that must be searched when fitting data. The curve should also be useful for forward modeling particle phase functions.

  13. Hybrid functionals and electronic structure of high-pressure phase of CdO

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, K.B.; Paliwal, U. [Department of Physics, M. L. Sukhadia University, Udaipur 313001 (India); Sharma, B.K. [Department of Physics, University of Rajasthan, Jaipur 302004 (India)

    2011-05-15

    The electronic band structure and density of states (DOS) of B2-phase cadmium oxide (CdO) are computed following the first-principles linear combination of atomic orbitals method applying the CRYSTAL code. The PBE correlation functional coupled with Becke's ansatz for exchange is considered for calculations. The electronic band structure and DOS are examined considering HF, B3LYP and hybrid schemes. Hybrid functionals are used with 25, 15, 10 and 5% mixing of Fock exchange with PBE-GGA. Depending on the correlation functionals, and different mixings in the hybrid schemes, B2-phase CdO may have an indirect positive band gap, a negative band gap or a zero gap. The effect of pd repulsion originating from pd hybridisation is visible in the calculated band structures. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Harmonic-phase path-integral approximation of thermal quantum correlation functions

    Science.gov (United States)

    Robertson, Christopher; Habershon, Scott

    2018-03-01

    We present an approximation to the thermal symmetric form of the quantum time-correlation function in the standard position path-integral representation. By transforming to a sum-and-difference position representation and then Taylor-expanding the potential energy surface of the system to second order, the resulting expression provides a harmonic weighting function that approximately recovers the contribution of the phase to the time-correlation function. This method is readily implemented in a Monte Carlo sampling scheme and provides exact results for harmonic potentials (for both linear and non-linear operators) and near-quantitative results for anharmonic systems for low temperatures and times that are likely to be relevant to condensed phase experiments. This article focuses on one-dimensional examples to provide insights into convergence and sampling properties, and we also discuss how this approximation method may be extended to many-dimensional systems.

  15. Effect of blonanserin on cognitive and social function in acute phase Japanese schizophrenia compared with risperidone

    Directory of Open Access Journals (Sweden)

    Hori H

    2014-03-01

    Full Text Available Hikaru Hori, Kenji Yamada, Dan Kamada, Yuka Shibata, Asuka Katsuki, Reiji Yoshimura, Jun NakamuraDepartment of Psychiatry, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, JapanBackground: This study aims to determine the effectiveness of blonanserin (BNS on the cognitive and social functions of patients with schizophrenia compared with risperidone (RIS during acute-phase (8-week treatment.Methods: A total of 39 schizophrenia inpatients were included in this study. The subjects received either BNS (N=20 or RIS (N=19, and the clinical responses were evaluated periodically. The concomitant use of mood stabilizers was not allowed. Efficacy was assessed with the Positive and Negative Syndrome Scale for schizophrenia. Cognition was assessed using the Brief Assessment of Cognition in Schizophrenia, Japanese-language version. Social function was assessed using the Life Assessment Scale for the Mentally Ill.Results: For both groups, each assessment exhibited a decrease in the mean change from baseline on the Positive and Negative Syndrome Scale. The depression subscale was significantly improved in the BNS group compared with the RIS group at 8 weeks after administration. BNS improved verbal fluency and executive function (cognitive function and daily living and work skills (social function. Compared with the RIS group, BNS was observed to improve daily living.Conclusion: BNS may improve psychotic symptoms, cognitive function, and daily living in patients with acute-phase schizophrenia. BNS may be superior to RIS in the improvement of daily living.Keywords: risperidone, blonanserin, schizophrenia, cognitive function, social function, acute-phase

  16. Phase equilibria and thermodynamic functions for Ag-Hg and Cu-Hg binary systems

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yajun, E-mail: yajunliu@gatech.edu [School of Materials and Energy, Guangdong University of Technology, Guangzhou, Guangdong 510006 (China); Wang, Guan [School of Electromechanical Engineering, Guangdong University of Technology, Guangzhou, Guangdong 510006 (China); Wang, Jiang [School of Materials Science and Engineering, Guilin University of Electronic Technology, Guilin, Guangxi 541004 (China); Chen, Yang [Mining, Metallurgy and Materials Research Department, General Research Institute for Nonferrous Metals, Beijing 100088 (China); Long, Zhaohui [School of Mechanical Engineering, Xiangtan University, Xiangtan, Hunan 411105 (China)

    2012-11-10

    Highlights: Black-Right-Pointing-Pointer The thermodynamic properties of Ag-Hg and Cu-Hg are explored in order to facilitate dental materials design. Black-Right-Pointing-Pointer A self-consistent set of thermodynamic parameters is obtained. Black-Right-Pointing-Pointer The experimental information can be well reproduced by the optimized thermodynamic data. - Abstract: In order to facilitate the computational design of new amalgams for novel dental alloys, the phase equilibria, phase diagrams and thermodynamic functions for Ag-Hg and Cu-Hg binary systems are explored in this work, based on the CALPHAD framework and experimental characterizations. The Gibbs free energies of the solution phases as well as the stoichiometric phases are calculated, with the aid of enthalpies of mixing, activities, enthalpies of formation, and phase equilibrium data. The thermodynamic descriptions provided in this work enable the stabilities of each phase at various temperatures and compositions to be well described, which contribute to the establishment of a general database to design novel metallic dental materials.

  17. Phase equilibria and thermodynamic functions for Ag–Hg and Cu–Hg binary systems

    International Nuclear Information System (INIS)

    Liu, Yajun; Wang, Guan; Wang, Jiang; Chen, Yang; Long, Zhaohui

    2012-01-01

    Highlights: ► The thermodynamic properties of Ag–Hg and Cu–Hg are explored in order to facilitate dental materials design. ► A self-consistent set of thermodynamic parameters is obtained. ► The experimental information can be well reproduced by the optimized thermodynamic data. - Abstract: In order to facilitate the computational design of new amalgams for novel dental alloys, the phase equilibria, phase diagrams and thermodynamic functions for Ag–Hg and Cu–Hg binary systems are explored in this work, based on the CALPHAD framework and experimental characterizations. The Gibbs free energies of the solution phases as well as the stoichiometric phases are calculated, with the aid of enthalpies of mixing, activities, enthalpies of formation, and phase equilibrium data. The thermodynamic descriptions provided in this work enable the stabilities of each phase at various temperatures and compositions to be well described, which contribute to the establishment of a general database to design novel metallic dental materials.

  18. Assessment of Autonomic Function by Phase Rectification of RRInterval Histogram Analysis in Chagas Disease

    Directory of Open Access Journals (Sweden)

    Olivassé Nasari Junior

    2015-06-01

    Full Text Available Background: In chronic Chagas disease (ChD, impairment of cardiac autonomic function bears prognostic implications. Phase‑rectification of RR-interval series isolates the sympathetic, acceleration phase (AC and parasympathetic, deceleration phase (DC influences on cardiac autonomic modulation. Objective: This study investigated heart rate variability (HRV as a function of RR-interval to assess autonomic function in healthy and ChD subjects. Methods: Control (n = 20 and ChD (n = 20 groups were studied. All underwent 60-min head-up tilt table test under ECG recording. Histogram of RR-interval series was calculated, with 100 ms class, ranging from 600–1100 ms. In each class, mean RR-intervals (MNN and root-mean-squared difference (RMSNN of consecutive normal RR-intervals that suited a particular class were calculated. Average of all RMSNN values in each class was analyzed as function of MNN, in the whole series (RMSNNT, and in AC (RMSNNAC and DC (RMSNNDC phases. Slopes of linear regression lines were compared between groups using Student t-test. Correlation coefficients were tested before comparisons. RMSNN was log-transformed. (α < 0.05. Results: Correlation coefficient was significant in all regressions (p < 0.05. In the control group, RMSNNT, RMSNNAC, and RMSNNDC significantly increased linearly with MNN (p < 0.05. In ChD, only RMSNNAC showed significant increase as a function of MNN, whereas RMSNNT and RMSNNDC did not. Conclusion: HRV increases in proportion with the RR-interval in healthy subjects. This behavior is lost in ChD, particularly in the DC phase, indicating cardiac vagal incompetence.

  19. Three-Phase Solid Oxide Fuel Cell Anode Microstructure Realization Using Two-Point Correlation Functions

    International Nuclear Information System (INIS)

    Baniassadi, Majid; Garmestani, Hamid; Li, Dongsheng; Ahzi, Said; Khaleel, Mohammad A.; Sun, Xin

    2011-01-01

    A Monte Carlo methodology is developed as a means for three-dimensional (3D) reconstruction of the microstructure of a three-phase anode used in solid oxide fuel cells, based on two-point statistical functions. The salient feature of the presented reconstruction methodology is the ability to realize the 3D microstructure from its 2D SEM image for a three-phase medium extendable to n-phase media. In the realization procedure, different phases of the heterogeneous medium are represented by different cells which are allowed to grow. The growth of cells, however, are controlled via several optimization parameters related to rotation, shrinkage, translation, distribution and growth rates of the cells. Indeed, the proposed realization algorithm can be categorized as a member of dynamic programming methods and is designed so comprehensive that can realize any desired microstructure. To be more specific, at first the initial 2D image is successfully reconstructed and then the final optimization parameters are used as the initial values for the initiation of the 3D reconstruction algorithm. This paper presents a novel hybrid stochastic methodology based on the colony and kinetic algorithm for the simulation of the virtual microstructure. The simulation procedure involves repeated realizations where each realization in turn consists of nucleation and growth of cells. For each of the subsequent realizations, the controlling parameters get updated by minimization of an objective function at the end of the preceding realization. Here, the objective function is defined based on the two-point correlation functions from the simulated and real microstructures. The kinetic growth algorithm is established on the cellular automata approach which facilitates the simulation procedure. Comparison of the two-point correlation functions from different sections of the final 3D reconstructed microstructure with the initial real microstructure shows a satisfactory agreement which confirms the

  20. Effect of blonanserin on cognitive and social function in acute phase Japanese schizophrenia compared with risperidone.

    Science.gov (United States)

    Hori, Hikaru; Yamada, Kenji; Kamada, Dan; Shibata, Yuka; Katsuki, Asuka; Yoshimura, Reiji; Nakamura, Jun

    2014-01-01

    This study aims to determine the effectiveness of blonanserin (BNS) on the cognitive and social functions of patients with schizophrenia compared with risperidone (RIS) during acute-phase (8-week) treatment. A total of 39 schizophrenia inpatients were included in this study. The subjects received either BNS (N=20) or RIS (N=19), and the clinical responses were evaluated periodically. The concomitant use of mood stabilizers was not allowed. Efficacy was assessed with the Positive and Negative Syndrome Scale for schizophrenia. Cognition was assessed using the Brief Assessment of Cognition in Schizophrenia, Japanese-language version. Social function was assessed using the Life Assessment Scale for the Mentally Ill. For both groups, each assessment exhibited a decrease in the mean change from baseline on the Positive and Negative Syndrome Scale. The depression subscale was significantly improved in the BNS group compared with the RIS group at 8 weeks after administration. BNS improved verbal fluency and executive function (cognitive function) and daily living and work skills (social function). Compared with the RIS group, BNS was observed to improve daily living. BNS may improve psychotic symptoms, cognitive function, and daily living in patients with acute-phase schizophrenia. BNS may be superior to RIS in the improvement of daily living.

  1. Enhancement of biomembrane functions under phase-separated conditions: A self-organized criticality phenomenon?

    International Nuclear Information System (INIS)

    Eze, M.O.; Chela Flores, J.

    1993-12-01

    Self-organized criticality (SOC) is hereby proposed as a possible physical basis for explaining observations in the temperature-dependence of the rates of biological membrane-associated events. The biomembrane undergoes a reversible, cooperative, thermotropic gel-to-liquid crystalline phase transition which is broad, and involves lateral phase separation. The lateral phase separated (rather than the totally gel-, or the totally liquid crystalline-) membrane state has been observed to be the state in which vital membrane functions are facilitated. The membrane in this unique state is viewed, for our purposes here, as a dynamical, extended dissipative system with spatial and temporal degrees of freedom, exhibiting power law behaviour, typical of the self-organized critical state. Experiments are suggested for verifying this hypothesis. (author). 30 refs

  2. Fundamentals of liquid phase for modern cermets and functionally graded cemented carbonitrides (FGCC)

    International Nuclear Information System (INIS)

    Chen, L.; Lengauer, W.; Ettmayer, P.; Dreyer, K.; Daub, H.W.; Kassel, D.

    2001-01-01

    Metallurgical reactions and microstructure developments during sintering of modern cermets and functionally graded cemented carbonitrides (FGCC) were investigated by modern thermal and analytical methods such as mass spectrometer (MS), differential thermal analysis (DTA), differential scanning calorimeter (DSC), dilatometer (DIL), microscopy and analytical electronic microscopy with energy dispersive spectrometer (EDS). The complex phase reactions and phase equilibrium in the multi-component system Ti/Mo/W/Ta/Nb/C,N-Co/Ni were studied. The melting behaviors in the systems of TiC-WC/MoC-Ni/Co, TiC-TiN-WC-Co and TiCN-TaC-WC-Co have been established. By better understanding of the mechanisms that govern the sintering processing and metallurgical reactions, new cermets and different types of functionally graded cemented carbonitrides (FGCC) with desired microstructures and properties were developed and fabricated. (author)

  3. The use of the Henyey-Greenstein phase function in Monte Carlo simulations in biomedical optics.

    Science.gov (United States)

    Binzoni, T; Leung, T S; Gandjbakhche, A H; Rüfenacht, D; Delpy, D T

    2006-09-07

    Monte Carlo (MC) simulations are often at the heart of the testing procedure in biomedical optics. One of the critical points in MC simulations is to define the new photon direction after each scattering event. One of the most popular solutions is to use the Henyey-Greenstein phase function or some linear combinations of it. In this note, we demonstrate that randomly generating the angle defining the new direction of a photon after a collision, by means of the Henyey-Greenstein phase function, is not equivalent to generating the cosine of this angle, as is classically done. In practice, it is demonstrated that for a nearly isotropic medium (asymmetry parameter g approximately 0) this discrepancy is not large, however for an anisotropic medium as is typically found in vivo (e.g. g = 0.98) the two methods give completely different results.

  4. Gait phase detection from sciatic nerve recordings in functional electrical stimulation systems for foot drop correction

    International Nuclear Information System (INIS)

    Chu, Jun-Uk; Song, Kang-Il; Han, Sungmin; Suh, Jun-Kyo Francis; Choi, Kuiwon; Youn, Inchan; Lee, Soo Hyun; Kang, Ji Yoon; Hwang, Dosik

    2013-01-01

    Cutaneous afferent activities recorded by a nerve cuff electrode have been used to detect the stance phase in a functional electrical stimulation system for foot drop correction. However, the implantation procedure was difficult, as the cuff electrode had to be located on the distal branches of a multi-fascicular nerve to exclude muscle afferent and efferent activities. This paper proposes a new gait phase detection scheme that can be applied to a proximal nerve root that includes cutaneous afferent fibers as well as muscle afferent and efferent fibers. To test the feasibility of this scheme, electroneurogram (ENG) signals were measured from the rat sciatic nerve during treadmill walking at several speeds, and the signal properties of the sciatic nerve were analyzed for a comparison with kinematic data from the ankle joint. On the basis of these experiments, a wavelet packet transform was tested to define a feature vector from the sciatic ENG signals according to the gait phases. We also propose a Gaussian mixture model (GMM) classifier and investigate whether it could be used successfully to discriminate feature vectors into the stance and swing phases. In spite of no significant differences in the rectified bin-integrated values between the stance and swing phases, the sciatic ENG signals could be reliably classified using the proposed wavelet packet transform and GMM classification methods. (paper)

  5. Characterization of Phase Transition in Heisenberg Fluids from Density Functional Theory

    International Nuclear Information System (INIS)

    Li Liangsheng; Li Li; Chen Xiaosong

    2009-01-01

    The phase transition of Heisenberg fluid has been investigated with the density functional theory in mean-field approximation (MF). The matrix of the second derivatives of the grand canonical potential Ω with respect to the particle density fluctuations and the magnetization fluctuations has been investigated and diagonalized. The smallest eigenvalue being 0 signalizes the phase instability and the related eigenvector characterizes this phase transition. We find a Curie line where the order parameter is pure magnetization and a spinodal where the order parameter is a mixture of particle density and magnetization. Along the spinodal, the character of phase instability changes continuously from predominant condensation to predominant ferromagnetic phase transition with the decrease of total density. The spinodal meets the Curie line at the critical endpoint with the reduced density ρ* = ρσ 3 = 0.224 and the reduced temperature T* = kT/ element of = 1.87 (σ is the diameter of Heisenberg hard sphere and element of is the coupling constant).

  6. Taming waveform inversion non-linearity through phase unwrapping of the model and objective functions

    KAUST Repository

    Alkhalifah, Tariq Ali

    2012-09-25

    Traveltime inversion focuses on the geometrical features of the waveform (traveltimes), which is generally smooth, and thus, tends to provide averaged (smoothed) information of the model. On other hand, general waveform inversion uses additional elements of the wavefield including amplitudes to extract higher resolution information, but this comes at the cost of introducing non-linearity to the inversion operator, complicating the convergence process. We use unwrapped phase-based objective functions in waveform inversion as a link between the two general types of inversions in a domain in which such contributions to the inversion process can be easily identified and controlled. The instantaneous traveltime is a measure of the average traveltime of the energy in a trace as a function of frequency. It unwraps the phase of wavefields yielding far less non-linearity in the objective function than that experienced with conventional wavefields, yet it still holds most of the critical wavefield information in its frequency dependency. However, it suffers from non-linearity introduced by the model (or reflectivity), as reflections from independent events in our model interact with each other. Unwrapping the phase of such a model can mitigate this non-linearity as well. Specifically, a simple modification to the inverted domain (or model), can reduce the effect of the model-induced non-linearity and, thus, make the inversion more convergent. Simple numerical examples demonstrate these assertions.

  7. Estimates of radiation over clouds and dust aerosols: Optimized number of terms in phase function expansion

    International Nuclear Information System (INIS)

    Ding Shouguo; Xie Yu; Yang Ping; Weng Fuzhong; Liu Quanhua; Baum, Bryan; Hu Yongxiang

    2009-01-01

    The bulk-scattering properties of dust aerosols and clouds are computed for the community radiative transfer model (CRTM) that is a flagship effort of the Joint Center for Satellite Data Assimilation (JCSDA). The delta-fit method is employed to truncate the forward peaks of the scattering phase functions and to compute the Legendre expansion coefficients for re-constructing the truncated phase function. Use of more terms in the expansion gives more accurate re-construction of the phase function, but the issue remains as to how many terms are necessary for different applications. To explore this issue further, the bidirectional reflectances associated with dust aerosols, water clouds, and ice clouds are simulated with various numbers of Legendre expansion terms. To have relative numerical errors smaller than 5%, the present analyses indicate that, in the visible spectrum, 16 Legendre polynomials should be used for dust aerosols, while 32 Legendre expansion terms should be used for both water and ice clouds. In the infrared spectrum, the brightness temperatures at the top of the atmosphere are computed by using the scattering properties of dust aerosols, water clouds and ice clouds. Although small differences of brightness temperatures compared with the counterparts computed with 4, 8, 128 expansion terms are observed at large viewing angles for each layer, it is shown that 4 terms of Legendre polynomials are sufficient in the radiative transfer computation at infrared wavelengths for practical applications.

  8. The phase function and density of the dust observed at comet 67P/Churyumov-Gerasimenko

    Science.gov (United States)

    Fulle, Marco; Bertini, I.; Della Corte, V.; Güttler, C.; Ivanovski, S.; La Forgia, F.; Lasue, J.; Levasseur-Regourd, A. C.; Marzari, F.; Moreno, F.; Mottola, S.; Naletto, G.; Palumbo, P.; Rinaldi, G.; Rotundi, A.; Sierks, H.; Barbieri, C.; Lamy, P. L.; Rodrigo, R.; Koschny, D.; Rickman, H.; Barucci, M. A.; Bertaux, J.-L.; Bodewits, D.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; Debei, S.; De Cecco, M.; Deller, J.; Fornasier, S.; Groussin, O.; Gutiérrez, P. J.; Hviid, H. S.; Ip, W. H.; Jorda, L.; Keller, H. U.; Knollenberg, J.; Kramm, J. R.; Kührt, E.; Küppers, M.; Lara, M. L.; Lazzarin, M.; López-Moreno, J. J.; Shi, X.; Thomas, N.; Tubiana, C.

    2018-02-01

    The OSIRIS camera onboard Rosetta measured the phase function of both the coma dust and the nucleus. The two functions have a very different slope versus the phase angle. Here we show that the nucleus phase function should be adopted to convert the brightness to the size of dust particles larger than 2.5 mm only. This makes the dust bursts observed close to Rosetta by OSIRIS, occurring about every hour, consistent with the fragmentation on impact with Rosetta of parent particles, whose flux agrees with the dust flux observed by GIADA. OSIRIS also measured the anti-sunward acceleration of the fragments, thus providing the first direct measurement of the solar radiation force acting on the dust fragments and thus of their bulk density, excluding any measurable rocket effect by the ice sublimation from the dust. The obtained particle density distribution has a peak matching the bulk density of most COSIMA particles, and represents a subset of the density distribution measured by GIADA. This implies a bias in the elemental abundances measured by COSIMA, which thus are consistent with the 67P dust mass fractions inferred by GIADA, i.e. (38 ± 8)% of hydrocarbons versus the (62 ± 8)% of sulfides and silicates.

  9. An adaptive meshfree method for phase-field models of biomembranes. Part I: Approximation with maximum-entropy basis functions

    OpenAIRE

    Rosolen, A.; Peco, C.; Arroyo, M.

    2013-01-01

    We present an adaptive meshfree method to approximate phase-field models of biomembranes. In such models, the Helfrich curvature elastic energy, the surface area, and the enclosed volume of a vesicle are written as functionals of a continuous phase-field, which describes the interface in a smeared manner. Such functionals involve up to second-order spatial derivatives of the phase-field, leading to fourth-order Euler–Lagrange partial differential equations (PDE). The solutions develop sharp i...

  10. A Seasonal Trend of Single Scattering Albedo in Southern African Biomass-burning Particles: Implications for Satellite Products and Estimates of Emissions for the World's Largest Biomass-burning Source

    Science.gov (United States)

    Eck, T. F.; Holben, B. N.; Reid, J. S.; Mukelabai, M. M.; Piketh, S. J.; Torres, O.; Jethva, H. T.; Hyer, E. J.; Ward, D. E.; Dubovik, O.; hide

    2013-01-01

    As a representative site of the southern African biomass-burning region, sun-sky data from the 15 year Aerosol Robotic Network (AERONET) deployment at Mongu, Zambia, was analyzed. For the biomass-burning season months (July-November), we investigate seasonal trends in aerosol single scattering albedo (SSA), aerosol size distributions, and refractive indices from almucantar sky scan retrievals. The monthly mean single scattering albedo at 440 nm in Mongu was found to increase significantly from approx.. 0.84 in July to approx. 0.93 in November (from 0.78 to 0.90 at 675 nm in these same months). There was no significant change in particle size, in either the dominant accumulation or secondary coarse modes during these months, nor any significant trend in the Angstrom exponent (440-870 nm; r(exp 2) = 0.02). A significant downward seasonal trend in imaginary refractive index (r(exp 2) = 0.43) suggests a trend of decreasing black carbon content in the aerosol composition as the burning season progresses. Similarly, burning season SSA retrievals for the Etosha Pan, Namibia AERONET site also show very similar increasing single scattering albedo values and decreasing imaginary refractive index as the season progresses. Furthermore, retrievals of SSA at 388 nm from the Ozone Monitoring Instrument satellite sensor show similar seasonal trends as observed by AERONET and suggest that this seasonal shift is widespread throughout much of southern Africa. A seasonal shift in the satellite retrieval bias of aerosol optical depth from the Moderate Resolution Imaging Spectroradiometer collection 5 dark target algorithm is consistent with this seasonal SSA trend since the algorithm assumes a constant value of SSA. Multi-angle Imaging Spectroradiometer, however, appears less sensitive to the absorption-induced bias.

  11. A seasonal trend of single scattering albedo in southern African biomass-burning particles: Implications for satellite products and estimates of emissions for the world's largest biomass-burning source

    Science.gov (United States)

    Eck, T. F.; Holben, B. N.; Reid, J. S.; Mukelabai, M. M.; Piketh, S. J.; Torres, O.; Jethva, H. T.; Hyer, E. J.; Ward, D. E.; Dubovik, O.; Sinyuk, A.; Schafer, J. S.; Giles, D. M.; Sorokin, M.; Smirnov, A.; Slutsker, I.

    2013-06-01

    As a representative site of the southern African biomass-burning region, sun-sky data from the 15 year Aerosol Robotic Network (AERONET) deployment at Mongu, Zambia, was analyzed. For the biomass-burning season months (July-November), we investigate seasonal trends in aerosol single scattering albedo (SSA), aerosol size distributions, and refractive indices from almucantar sky scan retrievals. The monthly mean single scattering albedo at 440 nm in Mongu was found to increase significantly from 0.84 in July to 0.93 in November (from 0.78 to 0.90 at 675 nm in these same months). There was no significant change in particle size, in either the dominant accumulation or secondary coarse modes during these months, nor any significant trend in the Ångström exponent (440-870 nm; r2 = 0.02). A significant downward seasonal trend in imaginary refractive index (r2 = 0.43) suggests a trend of decreasing black carbon content in the aerosol composition as the burning season progresses. Similarly, burning season SSA retrievals for the Etosha Pan, Namibia AERONET site also show very similar increasing single scattering albedo values and decreasing imaginary refractive index as the season progresses. Furthermore, retrievals of SSA at 388 nm from the Ozone Monitoring Instrument satellite sensor show similar seasonal trends as observed by AERONET and suggest that this seasonal shift is widespread throughout much of southern Africa. A seasonal shift in the satellite retrieval bias of aerosol optical depth from the Moderate Resolution Imaging Spectroradiometer collection 5 dark target algorithm is consistent with this seasonal SSA trend since the algorithm assumes a constant value of SSA. Multi-angle Imaging Spectroradiometer, however, appears less sensitive to the absorption-induced bias.

  12. Cognitive function in early clinical phase huntington disease after rivastigmine treatment.

    Science.gov (United States)

    Sešok, Sanja; Bolle, Nika; Kobal, Jan; Bucik, Valentin; Vodušek, David B

    2014-09-01

    In Huntington disease (HD) patients receiving rivastigmine treatment improvement of behavioral symptoms and of cognitive function (assessed with screening diagnostic instruments) has been reported. The aim of the present study was to verify such improvement in cognitive function by cognitive function assessment with a detailed neuropsychological battery covering all relevant cognitive systems expected to be impaired in early phase HD. Eighteen (18) HD patients entered the study and were randomly allocated to the rivastigmine and placebo group. All subjects underwent neuropsychological assessment at baseline. Follow-up neuropsychological assessment was applied after 6 months of rivastigmine or placebo treatment. Eighteen (18) healthy controls entered the study to control for practice effect and underwent neuropsychological assessment at baseline and after 6 months, without treatment. The neuropsychological battery consisted of assessment tools that are sensitive to cognitive impairment seen in early phase HD: CTMT, SDMT, Stroop (attention and information control), RFFT, TOL, Verbal fluency (executive functioning), CVLT-II, RCFT (learning and memory). Effect of rivastigmine and possible effect of practice was assessed using the mixed ANOVA model. No statistically significant effect of rivastigmine treatment on cognitive function in HD patients was detected. There was no evidence for practice or placebo effect. Detailed neuropsychological assessment did not confirm previously reported effect of rivastigmine treatment on cognitive function in HD patients. The limitations of our study are, in particular, small sample size and the lack of a single measure of relevant cognitive functioning in HD patients. Instead of focusing solely on statistical significance, a clinical relevance study is proposed to clarify the issue of rivastigmine effects in HD.

  13. Phase-space path-integral calculation of the Wigner function

    International Nuclear Information System (INIS)

    Samson, J H

    2003-01-01

    The Wigner function W(q, p) is formulated as a phase-space path integral, whereby its sign oscillations can be seen to follow from interference between the geometrical phases of the paths. The approach has similarities to the path-centroid method in the configuration-space path integral. Paths can be classified by the midpoint of their ends; short paths where the midpoint is close to (q, p) and which lie in regions of low energy (low P function of the Hamiltonian) will dominate, and the enclosed area will determine the sign of the Wigner function. As a demonstration, the method is applied to a sequence of density matrices interpolating between a Poissonian number distribution and a number state, each member of which can be represented exactly by a discretized path integral with a finite number of vertices. Saddle-point evaluation of these integrals recovers (up to a constant factor) the WKB approximation to the Wigner function of a number state

  14. Calculation of metallic and insulating phases of V{sub 2}O{sub 3} by hybrid density functionals

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yuzheng; Robertson, John, E-mail: jr@eng.cam.ac.uk [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Clark, Stewart J. [Department of Physics, University of Durham, Durham DH1 3LE (United Kingdom)

    2014-02-07

    The electronic structure of vanadium sesquioxide V{sub 2}O{sub 3} in its different phases has been calculated using the screened exchange hybrid density functional. The hybrid functional accurately reproduces the experimental electronic properties of all three phases, the paramagnetic metal (PM) phase, the anti-ferromagnetic insulating phase, and the Cr-doped paramagnetic insulating (PI) phase. We find that a fully relaxed supercell model of the Cr-doped PI phase based on the corundum structure has a monoclinic-like local strain around the substitutional Cr atoms. This is found to drive the PI-PM transition, consistent with a Peierls-Mott transition. The PI phase has a calculated band gap of 0.15 eV, in good agreement with experiment.

  15. Selective distributions of functionalized single-walled carbon nanotubes in a polymeric reverse hexagonal phase.

    Science.gov (United States)

    Ha, Jae-Min; Jang, Hyung-Sik; Lim, Sung-Hwan; Choi, Sung-Min

    2015-08-07

    We have investigated the distributions of individually isolated and hydrophilically functionalized single-walled carbon nanotubes (p-SWNTs) in the Pluronic L121-water system at the reverse hexagonal phase using small-angle X-ray scattering (SAXS) and contrast-matched small-angle neutron scattering (SANS) measurements. As the p-SWNT-L121-water system is transitioned from the lamellar phase to the reverse hexagonal phase with temperature, p-SWNTs which were selectively distributed in the polar layers of the lamellar structure become selectively distributed in the cylindrical polar cores of the reverse hexagonal structure, forming a hexagonal array of p-SWNTs. This was clearly confirmed by the contrast-matched SANS measurements. The selective distribution of p-SWNTs in the reverse hexagonal phase is driven by the selective affinity of p-SWNTs to the polar domains of the block copolymer system. The method demonstrated in this study provides a new route for fabricating ordered SWNT superstructures and may be applicable for inorganic 1D nanoparticles such as semiconducting, metallic and magnetic nanorods which are of great interest.

  16. Functional analysis of third ventriculostomy patency with phase-contrast MRI velocity measurements

    International Nuclear Information System (INIS)

    Lev, S.; Bhadelia, R.A.; Estin, D.; Heilman, C.B.; Wolpert, S.M.

    1997-01-01

    Our purpose was to explore the utility of cine phase-contrast MRI velocity measurements in determining the functional status of third ventriculostomies, and to correlate the quantitative velocity data with clinical follow-up. We examined six patients with third ventriculostomies and 12 normal subjects by phase-contrast MRI. The maximum craniocaudal to maximum caudocranial velocity range was measured at regions of interest near the third ventricular floor, and in cerebrospinal fluid anterior to the upper pons and spinal cord on midline sagittal images. Ratios of the velocities of both the third ventricle and prepontine space to the space anterior to the spinal cord were obtained. The velocities near the third ventricular floor and in the pontine cistern were significantly higher in patients than in normal subjects, but the velocity anterior to the spinal cord was similar between the groups. The velocity ratios, used to normalize individual differences, were also higher in patients than in controls. Two patients had lower velocity ratios than their fellows at the third ventricular floor and in the pontine cistern; one required a shunt 11 months later, while in the other, who had a third ventricular/thalamic tumor, the lower values probably reflect distortion of the third ventricular floor. We conclude that phase-contrast MR velocity measurements, specifically the velocity ratio between the high pontine cistern and the space anterior to the spinal cord, can help determine the functional status of third ventriculostomies. (orig.)

  17. Optimization of Sigma Phase Precipitates with Respect to the Functional Properties of Duplex Cast Steel

    Directory of Open Access Journals (Sweden)

    Z. Stradomski

    2012-04-01

    Full Text Available The paper presents the results of examination concerning optimization of the σ phase precipitates with respect to the functional properties of ferritic-austenitic cast steel. The examined material comprised two grades of corrosion-resistant cast steel, namely GX2CrNiMoN25-6-3 and GX2CrNiMoCuN25-6-3-3, used for example in elements of systems of wet flue gas desulphurisation in power industry. The operating conditions in media heated up to 70°C and containing Cl- and SO4 ions and solid particles produce high erosive and corrosive wear. The work proposes an application of the σ phase as a component of precipitation strengthening mechanism in order to increase the functional properties of the material. Morphology and quantities of σ phase precipitates were determined, as well as its influence on the erosion and corrosion wear resistance. It was shown that annealing at 800°C or 900°C significantly improves tribological properties as compared with the supersaturated state, and the best erosion and corrosion wear resistance achieved due to the ferrite decomposition δ → γ’ + σ was exhibited in the case of annealing at the temperature of 800°C for 3 hours.

  18. Continuous production of functionalized polymer particles employing the phase separation in polymer blend films.

    Science.gov (United States)

    Park, ChooJin; Hyun, Dong Choon; Lim, Min-Cheol; Kim, Su-Jeong; Kim, Young-Rok; Paik, Hyun-Jong; Jeong, Unyong

    2011-08-17

    This study reports a continuous prepartion of spherical or hemispherical polymer particles simply utilizing the phase separation in polymer blend films during the coating process. We took an advantage of the strong phase separation between a water-soluble crystalline polymer as a matrix and hydrophobic polymers as minor components. We demonstrated the prepartion of water-soluble polystyrene (PS) particles, nitrilotriacetic acid (NTA)-functionalized PS particles for protein separation, and semiconducting poly(3-hexylthiophene) (P3HT) particles. The sizes of the particles could be controlled by adjusting the film thickness and weight fraction of the minor component polymers in the blend film. It provides a simple facile way to prepare polymer particles in a continous process. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Thermodynamic functions, freezing transition, and phase diagram of dense carbon-oxygen mixtures in white dwarfs

    International Nuclear Information System (INIS)

    Iyetomi, H.; Ogata, S.; Ichimaru, S.

    1989-01-01

    Equations of state for dense carbon-oxygen (C-O) binary-ionic mixtures (BIM's) appropriate to the interiors of white dwarfs are investigated through Monte Carlo simulations, by solution of relevant integral equations and variational calculations in the density-functional formalism. It is thereby shown that the internal energies of the C-O BIM solids and fluids both obey precisely the linear mixing formulas. We then present an accurate calculation of the phase diagram associated with freezing transitions in such BIM materials, resulting in a novel prediction of an azeotropic diagram. Discontinuities of the mass density across the azeotropic phase boundaries are evaluated numerically for application to a study of white-dwarf evolution

  20. PEG 400-Based Phase Change Materials Nano-Enhanced with Functionalized Graphene Nanoplatelets

    Directory of Open Access Journals (Sweden)

    Marco A. Marcos

    2017-12-01

    Full Text Available This study presents new Nano-enhanced Phase Change Materials, NePCMs, formulated as dispersions of functionalized graphene nanoplatelets in a poly(ethylene glycol with a mass-average molecular mass of 400 g·mol−1 for possible use in Thermal Energy Storage. Morphology, functionalization, purity, molecular mass and thermal stability of the graphene nanomaterial and/or the poly(ethylene glycol were characterized. Design parameters of NePCMs were defined on the basis of a temporal stability study of nanoplatelet dispersions using dynamic light scattering. Influence of graphene loading on solid-liquid phase change transition temperature, latent heat of fusion, isobaric heat capacity, thermal conductivity, density, isobaric thermal expansivity, thermal diffusivity and dynamic viscosity were also investigated for designed dispersions. Graphene nanoplatelet loading leads to thermal conductivity enhancements up to 23% while the crystallization temperature reduces up to in 4 K. Finally, the heat storage capacities of base fluid and new designed NePCMs were examined by means of the thermophysical properties through Stefan and Rayleigh numbers. Functionalized graphene nanoplatelets leads to a slight increase in the Stefan number.

  1. PEG 400-Based Phase Change Materials Nano-Enhanced with Functionalized Graphene Nanoplatelets.

    Science.gov (United States)

    Marcos, Marco A; Cabaleiro, David; Guimarey, María J G; Comuñas, María J P; Fedele, Laura; Fernández, Josefa; Lugo, Luis

    2017-12-29

    This study presents new Nano-enhanced Phase Change Materials, NePCMs, formulated as dispersions of functionalized graphene nanoplatelets in a poly(ethylene glycol) with a mass-average molecular mass of 400 g·mol -1 for possible use in Thermal Energy Storage. Morphology, functionalization, purity, molecular mass and thermal stability of the graphene nanomaterial and/or the poly(ethylene glycol) were characterized. Design parameters of NePCMs were defined on the basis of a temporal stability study of nanoplatelet dispersions using dynamic light scattering. Influence of graphene loading on solid-liquid phase change transition temperature, latent heat of fusion, isobaric heat capacity, thermal conductivity, density, isobaric thermal expansivity, thermal diffusivity and dynamic viscosity were also investigated for designed dispersions. Graphene nanoplatelet loading leads to thermal conductivity enhancements up to 23% while the crystallization temperature reduces up to in 4 K. Finally, the heat storage capacities of base fluid and new designed NePCMs were examined by means of the thermophysical properties through Stefan and Rayleigh numbers. Functionalized graphene nanoplatelets leads to a slight increase in the Stefan number.

  2. Auditory sensitivity to spectral modulation phase reversal as a function of modulation depth.

    Science.gov (United States)

    Buss, Emily; Grose, John

    2018-01-01

    The present study evaluated auditory sensitivity to spectral modulation by determining the modulation depth required to detect modulation phase reversal. This approach may be preferable to spectral modulation detection with a spectrally flat standard, since listeners appear unable to perform the task based on the detection of temporal modulation. While phase reversal thresholds are often evaluated by holding modulation depth constant and adjusting modulation rate, holding rate constant and adjusting modulation depth supports rate-specific assessment of modulation processing. Stimuli were pink noise samples, filtered into seven octave-wide bands (0.125-8 kHz) and spectrally modulated in dB. Experiment 1 measured performance as a function of modulation depth to determine appropriate units for adaptive threshold estimation. Experiment 2 compared thresholds in dB for modulation detection with a flat standard and modulation phase reversal; results supported the idea that temporal cues were available at high rates for the former but not the latter. Experiment 3 evaluated spectral modulation phase reversal thresholds for modulation that was restricted to either one or two neighboring bands. Flanking bands of unmodulated noise had a larger detrimental effect on one-band than two-band targets. Thresholds for high-rate modulation improved with increasing carrier frequency up to 2 kHz, whereas low-rate modulation appeared more consistent across frequency, particularly in the two-band condition. Experiment 4 measured spectral weights for spectral modulation phase reversal detection and found higher weights for bands in the spectral center of the stimulus than for the lowest (0.125 kHz) or highest (8 kHz) band. Experiment 5 compared performance for highly practiced and relatively naïve listeners, and found weak evidence of a larger practice effect at high than low spectral modulation rates. These results provide preliminary data for a task that may provide a better estimate of

  3. Wigner’s phase-space function and atomic structure: II. Ground states for closed-shell atoms

    DEFF Research Database (Denmark)

    Springborg, Michael; Dahl, Jens Peder

    1987-01-01

    We present formulas for reduced Wigner phase-space functions for atoms, with an emphasis on the first-order spinless Wigner function. This function can be written as the sum of separate contributions from single orbitals (the natural orbitals). This allows a detailed study of the function. Here we...... display and analyze the function for the closed-shell atoms helium, beryllium, neon, argon, and zinc in the Hartree-Fock approximation. The quantum-mechanical exact results are compared with those obtained with the approximate Thomas-Fermi description of electron densities in phase space....

  4. Radiation-induced brain structural and functional abnormalities in presymptomatic phase and outcome prediction.

    Science.gov (United States)

    Ding, Zhongxiang; Zhang, Han; Lv, Xiao-Fei; Xie, Fei; Liu, Lizhi; Qiu, Shijun; Li, Li; Shen, Dinggang

    2018-01-01

    Radiation therapy, a major method of treatment for brain cancer, may cause severe brain injuries after many years. We used a rare and unique cohort of nasopharyngeal carcinoma patients with normal-appearing brains to study possible early irradiation injury in its presymptomatic phase before severe, irreversible necrosis happens. The aim is to detect any structural or functional imaging biomarker that is sensitive to early irradiation injury, and to understand the recovery and progression of irradiation injury that can shed light on outcome prediction for early clinical intervention. We found an acute increase in local brain activity that is followed by extensive reductions in such activity in the temporal lobe and significant loss of functional connectivity in a distributed, large-scale, high-level cognitive function-related brain network. Intriguingly, these radiosensitive functional alterations were found to be fully or partially recoverable. In contrast, progressive late disruptions to the integrity of the related far-end white matter structure began to be significant after one year. Importantly, early increased local brain functional activity was predictive of severe later temporal lobe necrosis. Based on these findings, we proposed a dynamic, multifactorial model for radiation injury and another preventive model for timely clinical intervention. Hum Brain Mapp 39:407-427, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  5. Separation of heavy metals from water by functionalized glycidyl methacrylate poly (high internal phase emulsions).

    Science.gov (United States)

    Huš, Sebastjan; Kolar, Mitja; Krajnc, Peter

    2016-03-11

    Removal of silver, lead and cadmium ions from both model solutions and real contaminated water was achieved, in a flow through manner, by using highly porous functionalized poly(glycidyl methacrylate) materials, prepared by the polymerisation of high internal phase emulsions (polyHIPE), with significant sorption differences between metals allowing for selective removal. PolyHIPEs, initially prepared from glycidyl methacrylate as a functional monomer, were functionalized with pentaerythritol tetrakis(3-mercaptopropionate), 1,9-nonanedithiol and 2-aminobenzenethiol via the epoxy ring opening on the polymer supports and applied in a flow-through manner via encasements into dedicated disk holders. Capacity of 21.7mg Ag per gram of polymer was found for 1,9-nonanedithiol functionalized polymers, while the capacity was decreasing with the decreasing ionic radius of the metal; the dynamics of sorption also depended on metal ion size and furthermore on the thiol used for the polymer functionalization. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Desalination membranes from functional block copolymer via non-solvent induced phase inversion

    Science.gov (United States)

    Sung, Hyemin; Poelma, Justin; Leibfarth, Frank; Hawker, Craig; Bang, Joona

    2012-02-01

    Commercially available reverse osmosis (RO) and forward osmosis (FO) membranes are most commonly derived from materials such as polysulfone, polyimide, and cellulose acetate. While these membranes have improved the efficiency of the desalination process, they suffer from mechanical and chemical stability, fouling issues, and low fluxes. In this study, we combine a well-established membrane formation method, non-solvent-induced phase separation, with the self-assembly of a functional amphiphilic block copolymersAn amine and acid functional polystyrene-block-poly(ethylene oxide-co-allyl glycidyl ether) were chosen for the membranes. Membranes were formed by casting a concentrated polymer solution (12 to 25 wt% polymer) on PET fabric followed by immersion in a non-solvent bath. Scanning electron microscopy revealed an asymmetric porous structure consisting of a dense skin layer on top of a highly porous layer. Membrane performance was investigating using an FO test cell under the seawater condition.

  7. Rescue of cortical neurovascular functions during the hyperacute phase of ischemia by peripheral sensory stimulation.

    Science.gov (United States)

    Liao, Lun-De; Liu, Yu-Hang; Lai, Hsin-Yi; Bandla, Aishwarya; Shih, Yen-Yu Ian; Chen, You-Yin; Thakor, Nitish V

    2015-03-01

    To investigate the potential therapeutic effects of peripheral sensory stimulation during the hyperacute phase of stroke, the present study utilized electrophysiology and photoacoustic imaging techniques to evaluate neural and vascular responses of the rat cortex following ischemic insult. We employed a rat model of photothrombotic ischemia (PTI), which targeted the forelimb region of the primary somatosensory cortex (S1FL), due to its high reproducibility in creating localized ischemic injury. We also established a hybrid, dual-modality system, including six-channel electrocorticography (ECoG) and functional photoacoustic microscopy (fPAM), termed ECoG-fPAM, to image brain functional responses to peripheral sensory stimulation during the hyperacute phase of PTI. Our results showed that the evoked cerebral blood volume (CBV) and hemoglobin oxygen saturation (SO2) recovered to 84±7.4% and 79±6.2% of the baseline, respectively, when stimulation was delivered within 2.5 h following PTI induction. Moreover, neural activity significantly recovered, with 77±8.6%, 76±5.3% and 89±8.2% recovery for the resting-state inter-hemispheric coherence, alpha-to-delta ratio (ADR) and somatosensory evoked potential (SSEP), respectively. Additionally, we integrated the CBV or SO2 with ADR values as a recovery indicator (RI) to assess functional recovery after PTI. The RI indicated that 80±4.2% of neurovascular function was preserved when stimulation was delivered within 2.5h. Additionally, stimulation treatment within this optimal time window resulted in a minimal infarct volume in the ischemic hemisphere (4.6±2.1%). In contrast, the infarct volume comprised 13.7±1.7% of the ischemic hemisphere when no stimulation treatment was applied. Copyright © 2014. Published by Elsevier Inc.

  8. Functional Super Read Out Driver Demonstrator for the Phase II Upgrade of the Atlas Tile Calorimeter

    CERN Document Server

    Carrió, F; The ATLAS collaboration; Ferrer, A; González, V; Higón, E; Moreno, P; Sanchis, E; Solans, C; Valero, A; Valls, J

    2011-01-01

    This work presents the implementation of a functional super Read Out Driver (sROD) demonstrator for the Phase II Upgrade of the ATLAS Tile Calorimeter (TileCal) in the LHC experiment. The proposed front-end for the Phase II Upgrade communicates with back-end electronics using a multifiber optical connector with a data rate of 57.6 Gbps using the GBT protocol. This functional sROD demonstrator aims to help in the understanding of the problems that could arise in the upgrade of back-end electronics. The demonstrator is composed of three different boards that have been developed in the framework of ATLAS activities: the Optical Multiplexer Board (OMB), the Read-Out Driver (ROD) and the Optical Link Card (OLC). The first two boards, OMB and ROD, are part of the current back-end system where OMB receives two optical fibers with redundant data from front-end, performs online CRC for data and send to ROD the data from the error-free fiber; and ROD is the main element of the back-end electronics and it is responsible...

  9. Dynamics of two-phase interfaces and surface tensions: A density-functional theory perspective

    Science.gov (United States)

    Yatsyshin, Petr; Sibley, David N.; Duran-Olivencia, Miguel A.; Kalliadasis, Serafim

    2016-11-01

    Classical density functional theory (DFT) is a statistical mechanical framework for the description of fluids at the nanoscale, where the inhomogeneity of the fluid structure needs to be carefully accounted for. By expressing the grand free-energy of the fluid as a functional of the one-body density, DFT offers a theoretically consistent and computationally accessible way to obtain two-phase interfaces and respective interfacial tensions in a ternary solid-liquid-gas system. The dynamic version of DFT (DDFT) can be rigorously derived from the Smoluchowsky picture of the dynamics of colloidal particles in a solvent. It is generally agreed that DDFT can capture the diffusion-driven evolution of many soft-matter systems. In this context, we use DDFT to investigate the dynamic behaviour of two-phase interfaces in both equilibrium and dynamic wetting and discuss the possibility of defining a time-dependent surface tension, which still remains in debate. We acknowledge financial support from the European Research Council via Advanced Grant No. 247031 and from the Engineering and Physical Sciences Research Council of the UK via Grants No. EP/L027186 and EP/L020564.

  10. Analysis of a phase synchronized functional network based on the rhythm of brain activities

    International Nuclear Information System (INIS)

    Li Ling; Jin Zhen-Lan; Li Bin

    2011-01-01

    Rhythm of brain activities represents oscillations of postsynaptic potentials in neocortex, therefore it can serve as an indicator of the brain activity state. In order to check the connectivity of brain rhythm, this paper develops a new method of constructing functional network based on phase synchronization. Electroencephalogram (EEG) data were collected while subjects looking at a green cross in two states, performing an attention task and relaxing with eyes-open. The EEG from these two states was filtered by three band-pass filters to obtain signals of theta (4–7 Hz), alpha (8–13 Hz) and beta (14–30 Hz) bands. Mean resultant length was used to estimate strength of phase synchronization in three bands to construct networks of both states, and mean degree K and cluster coefficient C of networks were calculated as a function of threshold. The result shows higher cluster coefficient in the attention state than in the eyes-open state in all three bands, suggesting that cluster coefficient reflects brain state. In addition, an obvious fronto-parietal network is found in the attention state, which is a well-known attention network. These results indicate that attention modulates the fronto-parietal connectivity in different modes as compared with the eyes-open state. Taken together this method is an objective and important tool to study the properties of neural networks of brain rhythm. (interdisciplinary physics and related areas of science and technology)

  11. Second Language Word Learning through Repetition and Imitation: Functional Networks as a Function of Learning Phase and Language Distance.

    Science.gov (United States)

    Ghazi-Saidi, Ladan; Ansaldo, Ana Ines

    2017-01-01

    Introduction and Aim : Repetition and imitation are among the oldest second language (L2) teaching approaches and are frequently used in the context of L2 learning and language therapy, despite some heavy criticism. Current neuroimaging techniques allow the neural mechanisms underlying repetition and imitation to be examined. This fMRI study examines the influence of verbal repetition and imitation on network configuration. Integration changes within and between the cognitive control and language networks were studied, in a pair of linguistically close languages (Spanish and French), and compared to our previous work on a distant language pair (Ghazi-Saidi et al., 2013). Methods : Twelve healthy native Spanish-speaking (L1) adults, and 12 healthy native Persian-speaking adults learned 130 new French (L2) words, through a computerized audiovisual repetition and imitation program. The program presented colored photos of objects. Participants were instructed to look at each photo and pronounce its name as closely as possible to the native template (imitate). Repetition was encouraged as many times as necessary to learn the object's name; phonological cues were provided if necessary. Participants practiced for 15 min, over 30 days, and were tested while naming the same items during fMRI scanning, at week 1 (shallow learning phase) and week 4 (consolidation phase) of training. To compare this set of data with our previous work on Persian speakers, a similar data analysis plan including accuracy rates (AR), response times (RT), and functional integration values for the language and cognitive control network at each measure point was included, with further L1-L2 direct comparisons across the two populations. Results and Discussion : The evidence shows that learning L2 words through repetition induces neuroplasticity at the network level. Specifically, L2 word learners showed increased network integration after 3 weeks of training, with both close and distant language

  12. Second Language Word Learning through Repetition and Imitation: Functional Networks as a Function of Learning Phase and Language Distance

    Science.gov (United States)

    Ghazi-Saidi, Ladan; Ansaldo, Ana Ines

    2017-01-01

    Introduction and Aim: Repetition and imitation are among the oldest second language (L2) teaching approaches and are frequently used in the context of L2 learning and language therapy, despite some heavy criticism. Current neuroimaging techniques allow the neural mechanisms underlying repetition and imitation to be examined. This fMRI study examines the influence of verbal repetition and imitation on network configuration. Integration changes within and between the cognitive control and language networks were studied, in a pair of linguistically close languages (Spanish and French), and compared to our previous work on a distant language pair (Ghazi-Saidi et al., 2013). Methods: Twelve healthy native Spanish-speaking (L1) adults, and 12 healthy native Persian-speaking adults learned 130 new French (L2) words, through a computerized audiovisual repetition and imitation program. The program presented colored photos of objects. Participants were instructed to look at each photo and pronounce its name as closely as possible to the native template (imitate). Repetition was encouraged as many times as necessary to learn the object’s name; phonological cues were provided if necessary. Participants practiced for 15 min, over 30 days, and were tested while naming the same items during fMRI scanning, at week 1 (shallow learning phase) and week 4 (consolidation phase) of training. To compare this set of data with our previous work on Persian speakers, a similar data analysis plan including accuracy rates (AR), response times (RT), and functional integration values for the language and cognitive control network at each measure point was included, with further L1-L2 direct comparisons across the two populations. Results and Discussion: The evidence shows that learning L2 words through repetition induces neuroplasticity at the network level. Specifically, L2 word learners showed increased network integration after 3 weeks of training, with both close and distant language pairs

  13. Spectral Weighting Functions for Single-symbol Phase-noise Specifications in OFDM Systems

    NARCIS (Netherlands)

    Hoeksema, F.W.; Schiphorst, Roelof; Slump, Cornelis H.

    2003-01-01

    For the specification of phase-noise requirements for the front-end of a HiperLAN/2 system we investigated available literature on the subject. Literature differed in several aspects. One aspect is in the type of phase-noise used (Wiener phase-noise or small-angle phase noise). A Wiener phase-noise

  14. The effect of selenium supplementation on acute phase reactants and thyroid function tests in hemodialysis patients.

    Science.gov (United States)

    Omrani, Hamid Reza; Rahimi, Mehrali; Nikseresht, Kanan

    2015-03-01

    Selenium deficiency is a common problem in patients with chronic kidney disease (CKD). This micronutrient has anti-inflammatory and anti-oxidant effects. Selenium is also found in high concentrations in the thyroid gland. To determine the effect of selenium supplementation on thyroid function tests and acute phase reactants in hemodialysis patients. In this double-blinded randomized clinical in 3 months, 64 hemodialysis patients with selenium deficiency were divided into experimental (received selenium supplementation; 32 cases) or control group (received placebo; 32 cases). Erythrocyte sedimentation rate (ESR), ferritin, quantitative C-reactive protein (CRP) and thyroid function tests (TFTs) including thyroid stimulating hormone (TSH), T3 resin uptake (T3RU), and free T4 were measured before and after the intervention and compared between experimental and control groups. At baseline, no significant difference was found between experimental and control groups regarding CRP, ESR and ferritin serum levels. Likewise, after intervention, no significant difference was found between experimental and control groups for CRP (14.77 ± 17.93 vs. 18.29 ± 21.56 mg/L), ESR (32.90 ± 32.62 vs. 33.91 ± 31.15 mm/h) and ferritin (528.6 ± 423.07 vs. 519.52 ± 345.59 ng/mL). At baseline, no significant difference was found between experimental and control groups regarding TFTs. Likewise, after intervention, no significant difference was found between experimental and control groups for TSH (3.7 ± 2.22 vs. 2.84 ± 1.88 µU/mL), free T4 (7.19 ± 1.98 vs. 7.02 ± 1.87 µg/dL) and T3RU (30.04 ± 2.28% vs. 29.2 ± 1.98%). Oral selenium supplementation for three months did not have any significant effect on thyroid function tests or acute phase reactants.

  15. A BASIC program for an IBM PC compatible computer for drawing the weak phase object contrast transfer function

    International Nuclear Information System (INIS)

    Olsen, A.; Skjerpe, P.

    1989-01-01

    This report describes a computer program which is useful in high resolution microscopy. The program is written in EBASIC and calculates the weak phase object contrast transfer function as function of instrumental and imaging parameters. The function is plotted on the PC graphics screen, and by a Print Screen command the function can be copied to the printer. The program runs on both the Hercules graphic card and the IBM CGA card. 2 figs

  16. The role of Minkowski functionals in the thermodynamics of two-phase systems

    Science.gov (United States)

    Eder, Gerhard

    2018-01-01

    Within this work quite old concepts from integral geometry are applied to classical equilibrium thermodynamics of two-phase systems. In addition to the area as basic interfacial quantity the full geometric characterization of the interface is used, which includes the two remaining Minkowski functionals, the mean curvature integral and the Euler Poincaré characteristic. The basic energetic characteristic of the interface (i.e. the interfacial tension) is extended by two additional properties: edge force as (up to a factor 4/π) the work necessary to form a right-angled edge of unit length, and item energy as the work to form an additional item in the phase morphology. Both quantities are of increasing importance, when going to micro- and nano-scales. They are subsequently used for interfaces of arbitrary shape to derive a relationship extending the classical Young-Laplace equation. The supplementary contribution is proportional to the Gaussian curvature, with the edge force as proportionality constant. Furthermore, both edge force and item energy are shown to be applicable to the description of crystal nucleation in liquids (extending the classical Becker Döring theory). It turns out, that even above the thermodynamic melting temperature stable nuclei can be present in the liquid phase. They immediately are able to grow when quenched to a temperature below a characteristic temperature. This temperature of spontaneous homogeneous nucleation is simply connected to the edge force, whereas the number of stable clusters per unit volume is dominated by the item energy. Finally, the additional energetic interfacial properties are used in a similar way to characterize the stability of emulsions.

  17. [Pulmonary function of children with acute leukemia in maintenance phase of chemotherapy].

    Science.gov (United States)

    de Macêdo, Thalita Medeiros Fernandes; Campos, Tania Fernandes; Mendes, Raquel Emanuele de França; França, Danielle Corrêa; Chaves, Gabriela Suéllen da Silva; de Mendonça, Karla Morganna Pereira Pinto

    2014-12-01

    The aim of this study was to assess the pulmonary function of children with acute leukemia. Cross-sectional observational analytical study that enrolled 34 children divided into groups A (17 with acute leukemia in the maintenance phase of chemotherapy) and B (17 healthy children). The groups were matched for sex, age and height. Spirometry was measured using a spirometer Microloop Viasys(®) in accordance with American Thoracic Society and European Respiratory Society guidelines. Maximal respiratory pressures were measured with an MVD300 digital manometer (Globalmed(®)). Maximal inspiratory pressures and maximal expiratory pressures were measured from residual volume and total lung capacity, respectively. Group A showed a significant decrease in maximal inspiratory pressures when compared to group B. No significant difference was found between the spirometric values of the two groups, nor was there any difference between maximal inspiratory pressure and maximal expiratory pressure values in group A compared to the lower limit values proposed as reference. Children with acute leukemia, myeloid or lymphoid, during the maintenance phase of chemotherapy exhibited unchanged spirometric variables and maximal expiratory pressure; However, there was a decrease in inspiratory muscle strength. Copyright © 2014 Associação de Pediatria de São Paulo. Publicado por Elsevier Editora Ltda. All rights reserved.

  18. Pulmonary function of children with acute leukemia in maintenance phase of chemotherapy

    Directory of Open Access Journals (Sweden)

    Thalita Medeiros Fernandes de Macêdo

    2014-12-01

    Full Text Available OBJECTIVE: The aim of this study was to assess the pulmonary function of children with acute leukemia.METHODS: Cross-sectional observational analytical study that enrolled 34 children divided into groups A (17 with acute leukemia in the maintenance phase of chemotherapy and B (17 healthy children. The groups were matched for sex, age and height. Spirometry was measured using a spirometer Microloop Viasys(r in accordance with American Thoracic Society and European Respiratory Society guidelines. Maximal respiratory pressures were measured with an MVD300 digital manometer (Globalmed(r. Maximal inspiratory pressures and maximal expiratory pressures were measured from residual volume and total lung capacity, respectively.RESULTS: Group A showed a significant decrease in maximal inspiratory pressures when compared to group B. No significant difference was found between the spirometric values of the two groups, nor was there any difference between maximal inspiratory pressure and maximal expiratory pressure values in group A compared to the lower limit values proposed as reference.CONCLUSION: Children with acute leukemia, myeloid or lymphoid, during the maintenance phase of chemotherapy exhibited unchanged spirometric variables and maximal expiratory pressure; However, there was a decrease in inspiratory muscle strength.

  19. Effect of carbon addition on functional and mechnical properties of the Ni3Al phase

    Directory of Open Access Journals (Sweden)

    E. Olejnik

    2012-10-01

    Full Text Available Casting technology was applied and research was carried out on two alloys based on the Ni3Al phase with variable carbon content of 0,2 and 1,25 wt. % C, respectively. Resistance to abrasive wear, friction coefficient and Vickers microhardness were determined. Metallographic studies were conducted to examine the macrostructure and microstructure of the investigated alloys. An increase in resistance to abrasive wear and microhardness of alloy containing 1,25 wt. % C was observed. The coefficient of friction was determined, which for the alloy with increased carbon content was much lower than for the alloy containing 0,2 wt. % C. Structural changes were reported to have some effect on functional and mechanical properties of the examined alloys.

  20. Study on objective functions for the slow shot phase in high-pressure die casting

    Science.gov (United States)

    Frings, Markus; Behr, Marek; Elgeti, Stefanie

    2016-10-01

    High-pressure die casting is an important process in the field of aluminum processing. Especially during the slow shot phase, the process parameters immensely influence the cast part quality. At the current state of the art, the appropriate process parameters are identified based on running-in trials and significant experience. To translate this experience into a mathematical framework is the aim of this work. The idea is to shift the running-in trials to the computer—now in the form of a numerical optimization. In view of the optimization, this paper presents a selection of objective functions. These are assessed with the respect to (1) their suitability as an overall quality measure of the casting process and (2) the extent to which they reflect the goals of the casting process.

  1. Random phase approximation correlation energy using a compact representation for linear response functions: application to solids

    Science.gov (United States)

    Kaoui, Fawzi; Rocca, Dario

    2016-01-01

    A new approach was recently presented to compute correlation energies within the random phase approximation using Lanczos chains and an optimal basis set (Rocca 2014 J. Chem. Phys. 140 18A501). This novel method avoids the explicit calculation of conduction states and represents linear response functions on a compact auxiliary basis set obtained from the diagonalization of an approximate dielectric matrix that contains only the kinetic energy contribution. Here, we extend this formalism, originally implemented for molecular systems, to treat periodic solids. In particular, the approximate dielectric matrix used to build the auxiliary basis set is generalized to avoid unphysical negative gaps, that make the model inefficient. The numerical convergence of the method is discussed and the accuracy is demonstrated considering a set including three covalently bonded (C, Si, and SiC) and three weakly bonded (Ne, Ar, and Kr) solids.

  2. Anharmonic Rovibrational Partition Functions for Fluxional Species at High Temperatures via Monte Carlo Phase Space Integrals

    Energy Technology Data Exchange (ETDEWEB)

    Jasper, Ahren W. [Chemical Sciences and Engineering; Gruey, Zackery B. [Chemical Sciences and Engineering; Harding, Lawrence B. [Chemical Sciences and Engineering; Georgievskii, Yuri [Chemical Sciences and Engineering; Klippenstein, Stephen J. [Chemical Sciences and Engineering; Wagner, Albert F. [Chemical Sciences and Engineering

    2018-02-03

    Monte Carlo phase space integration (MCPSI) is used to compute full dimensional and fully anharmonic, but classical, rovibrational partition functions for 22 small- and medium-sized molecules and radicals. Several of the species considered here feature multiple minima and low-frequency nonlocal motions, and efficiently sampling these systems is facilitated using curvilinear (stretch, bend, and torsion) coordinates. The curvilinear coordinate MCPSI method is demonstrated to be applicable to the treatment of fluxional species with complex rovibrational structures and as many as 21 fully coupled rovibrational degrees of freedom. Trends in the computed anharmonicity corrections are discussed. For many systems, rovibrational anharmonicities at elevated temperatures are shown to vary consistently with the number of degrees of freedom and with temperature once rovibrational coupling and torsional anharmonicity are accounted for. Larger corrections are found for systems with complex vibrational structures, such as systems with multiple large-amplitude modes and/or multiple minima.

  3. Raman Lidar Measurements of Aerosol Extinction and Backscattering. Report 2; Derivation of Aerosol Real Refractive Index, Single-Scattering Albedo, and Humidification Factor using Raman Lidar and Aircraft Size Distribution

    Science.gov (United States)

    Ferrare, R. A.; Melfi, S. H.; Whiteman, D. N.; Evans, K. D.; Poellot, M.; Kaufman, Y. J.

    1998-01-01

    Aerosol backscattering and extinction profiles measured by the NASA Goddard Space Flight Center Scanning Raman Lidar (SRL) during the remote cloud sensing (RCS) intensive operations period (IOP) at the Department of Energy Atmospheric Radiation Measurement (ARM) southern Great Plains (SGP) site during two nights in April 1994 are discussed. These profiles are shown to be consistent with the simultaneous aerosol size distribution measurements made by a PCASP (Passive Cavity Aerosol Spectrometer Probe) optical particle counter flown on the University of North Dakota Citation aircraft. We describe a technique which uses both lidar and PCASP measurements to derive the dependence of particle size on relative humidity, the aerosol real refractive index n, and estimate the effective single-scattering albedo Omega(sub 0). Values of n ranged between 1.4-1.5 (dry) and 1.37-1.47 (wet); Omega(sub 0) varied between 0.7 and 1.0. The single-scattering albedo derived from this technique is sensitive to the manner in which absorbing particles are represented in the aerosol mixture; representing the absorbing particles as an internal mixture rather than the external mixture assumed here results in generally higher values of Omega(sub 0). The lidar measurements indicate that the change in particle size with relative humidity as measured by the PCASP can be represented in the form discussed by Hattel with the exponent gamma = 0.3 + or - 0.05. The variations in aerosol optical and physical characteristics captured in the lidar and aircraft size distribution measurements are discussed in the context of the meteorological conditions observed during the experiment.

  4. Vertical variability of aerosol single-scattering albedo and equivalent black carbon concentration based on in-situ and remote sensing techniques during the iAREA campaigns in Ny-Ålesund

    Science.gov (United States)

    Markowicz, K. M.; Ritter, C.; Lisok, J.; Makuch, P.; Stachlewska, I. S.; Cappelletti, D.; Mazzola, M.; Chilinski, M. T.

    2017-09-01

    This work presents a methodology for obtaining vertical profiles of aerosol single scattering properties based on a combination of different measurement techniques. The presented data were obtained under the iAREA (Impact of absorbing aerosols on radiative forcing in the European Arctic) campaigns conducted in Ny-Ålesund (Spitsbergen) during the spring seasons of 2015-2017. The retrieval uses in-situ observations of black carbon concentration and absorption coefficient measured by a micro-aethalometer AE-51 mounted onboard a tethered balloon, as well as remote sensing data obtained from sun photometer and lidar measurements. From a combination of the balloon-borne in-situ and the lidar data, we derived profiles of single scattering albedo (SSA) as well as absorption, extinction, and aerosol number concentration. Results have been obtained in an altitude range from about 400 m up to 1600 m a.s.l. and for cases with increased aerosol load during the Arctic haze seasons of 2015 and 2016. The main results consist of the observation of increasing values of equivalent black carbon (EBC) and absorption coefficient with altitude, and the opposite trend for aerosol concentration for particles larger than 0.3 μm. SSA was retrieved with the use of lidar Raman and Klett algorithms for both 532 and 880 nm wavelengths. In most profiles, SSA shows relatively high temporal and altitude variability. Vertical variability of SSA computed from both methods is consistent; however, some discrepancy is related to Raman retrieval uncertainty and absorption coefficient estimation from AE-51. Typically, very low EBC concentration in Ny-Ålesund leads to large error in the absorbing coefficient. However, SSA uncertainty for both Raman and Klett algorithms seems to be reasonable, e.g. SSA of 0.98 and 0.95 relate to an error of ±0.01 and ± 0.025, respectively.

  5. Comment on 'the use of the Henyey-Greenstein phase function in Monte Carlo simulations in biomedical optics'.

    Science.gov (United States)

    Binzoni, T; Leung, T S; Gandjbakhche, A H; Rüfenacht, D; Delpy, D T

    2006-11-21

    In this letter the authors highlight the presence of an error appearing in the discussion of the note 'The use of the Henyey-Greenstein phase function in Monte Carlo simulations in biomedical optics' previously published by them (Binzoni et al 2006 Phys. Med. Biol. 51 N313). In the light of this error, the discussion and conclusions in the original paper are revised in this letter and the role of the use of the phase functions in MC simulations, interpreted in probabilistic terms, is better clarified. The exact definition for the probability density function for the deflection angle, in the case of the Henyey-Greenstein model, is also given.

  6. EXOPLANET ALBEDO SPECTRA AND COLORS AS A FUNCTION OF PLANET PHASE, SEPARATION, AND METALLICITY

    International Nuclear Information System (INIS)

    Cahoy, Kerri L.; Marley, Mark S.; Fortney, Jonathan J.

    2010-01-01

    First generation space-based optical coronagraphic telescopes will obtain images of cool gas- and ice-giant exoplanets around nearby stars. Exoplanets lying at planet-star separations larger than about 1 AU-where an exoplanet can be resolved from its parent star-have spectra that are dominated by reflected light to beyond 1 μm and punctuated by molecular absorption features. Here, we consider how exoplanet albedo spectra and colors vary as a function of planet-star separation, metallicity, mass, and observed phase for Jupiter and Neptune analogs from 0.35 to 1 μm. We model Jupiter analogs with 1x and 3x the solar abundance of heavy elements, and Neptune analogs with 10x and 30x the solar abundance of heavy elements. Our model planets orbit a solar analog parent star at separations of 0.8 AU, 2 AU, 5 AU, and 10 AU. We use a radiative-convective model to compute temperature-pressure profiles. The giant exoplanets are found to be cloud-free at 0.8 AU, possess H 2 O clouds at 2 AU, and have both NH 3 and H 2 O clouds at 5 AU and 10 AU. For each model planet we compute moderate resolution (R = λ/Δλ ∼ 800) albedo spectra as a function of phase. We also consider low-resolution spectra and colors that are more consistent with the capabilities of early direct imaging capabilities. As expected, the presence and vertical structure of clouds strongly influence the albedo spectra since cloud particles not only affect optical depth but also have highly directional scattering properties. Observations at different phases also probe different volumes of atmosphere as the source-observer geometry changes. Because the images of the planets themselves will be unresolved, their phase will not necessarily be immediately obvious, and multiple observations will be needed to discriminate between the effects of planet-star separation, metallicity, and phase on the observed albedo spectra. We consider the range of these combined effects on spectra and colors. For example, we find that

  7. Ground-State Gas-Phase Structures of Inorganic Molecules Predicted by Density Functional Theory Methods

    KAUST Repository

    Minenkov, Yury

    2017-11-29

    We tested a battery of density functional theory (DFT) methods ranging from generalized gradient approximation (GGA) via meta-GGA to hybrid meta-GGA schemes as well as Møller–Plesset perturbation theory of the second order and a single and double excitation coupled-cluster (CCSD) theory for their ability to reproduce accurate gas-phase structures of di- and triatomic molecules derived from microwave spectroscopy. We obtained the most accurate molecular structures using the hybrid and hybrid meta-GGA approximations with B3PW91, APF, TPSSh, mPW1PW91, PBE0, mPW1PBE, B972, and B98 functionals, resulting in lowest errors. We recommend using these methods to predict accurate three-dimensional structures of inorganic molecules when intramolecular dispersion interactions play an insignificant role. The structures that the CCSD method predicts are of similar quality although at considerably larger computational cost. The structures that GGA and meta-GGA schemes predict are less accurate with the largest absolute errors detected with BLYP and M11-L, suggesting that these methods should not be used if accurate three-dimensional molecular structures are required. Because of numerical problems related to the integration of the exchange–correlation part of the functional and large scattering of errors, most of the Minnesota models tested, particularly MN12-L, M11, M06-L, SOGGA11, and VSXC, are also not recommended for geometry optimization. When maintaining a low computational budget is essential, the nonseparable gradient functional N12 might work within an acceptable range of error. As expected, the DFT-D3 dispersion correction had a negligible effect on the internuclear distances when combined with the functionals tested on nonweakly bonded di- and triatomic inorganic molecules. By contrast, the dispersion correction for the APF-D functional has been found to shorten the bonds significantly, up to 0.064 Å (AgI), in Ag halides, BaO, BaS, BaF, BaCl, Cu halides, and Li and

  8. Differential S-phase progression after irradiation of p53 functional versus non-functional tumour cells

    Directory of Open Access Journals (Sweden)

    Zölzer Friedo

    2014-12-01

    Full Text Available Background. Many pathways seem to be involved in the regulation of the intra-S-phase checkpoint after exposure to ionizing radiation, but the role of p53 has proven to be rather elusive. Here we have a closer look at the progression of irradiated cells through S-phase in dependence of their p53 status.

  9. Molecular simulations and density functional theory calculations of bromine in clathrate hydrate phases

    Energy Technology Data Exchange (ETDEWEB)

    Dureckova, Hana, E-mail: houci059@uottawa.ca; Woo, Tom K., E-mail: tom.woo@uottawa.ca [Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 5N6 (Canada); Alavi, Saman, E-mail: saman.alavi@nrc-cnrc.gc.ca [Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 5N6 (Canada); National Research Council of Canada, 100 Sussex Dr., Ottawa, Ontario K1N 6N5 (Canada); Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z3 (Canada)

    2016-01-28

    Bromine forms a tetragonal clathrate hydrate structure (TS-I) very rarely observed in clathrate hydrates of other guest substances. The detailed structure, energetics, and dynamics of Br{sub 2} and Cl{sub 2} in TS-I and cubic structure I (CS-I) clathrate hydrates are studied in this work using molecular dynamics and quantum chemical calculations. X-ray diffraction studies show that the halogen-water–oxygen distances in the cages of these structures are shorter than the sum of the van der Waals radii of halogen and oxygen atoms. This suggests that the stabilizing effects of halogen bonding or other non-covalent interactions (NCIs) may contribute to the formation of the unique tetragonal bromine hydrate structure. We performed molecular dynamics simulations of Br{sub 2} and Cl{sub 2} clathrate hydrates using our previously developed five-site charge models for the dihalogen molecules [Dureckova et al. Can. J. Chem. 93, 864 (2015)] which reproduce the computed electrostatic potentials of the dihalogens and account for the electropositive σ-hole of the halogen bond donor (the dihalogen). Analysis of the radial distribution functions, enthalpies of encapsulation, velocity and orientation autocorrelation functions, and polar angle distributions are carried out for Br{sub 2} and Cl{sub 2} guests in various cages to contrast the properties of these guests in the TS-I and CS-I phases. Quantum chemical partial geometry optimizations of Br{sub 2} and Cl{sub 2} guests in the hydrate cages using the M06-2X functional give short halogen-water distances compatible with values observed in X-ray diffraction experiments. NCI plots of guest-cage structures are generated to qualitatively show the relative strength of the non-bonding interactions between dihalogens and water molecules. The differences between behaviors of Br{sub 2} and Cl{sub 2} guests in the hydrate cages may explain why bromine forms the unique TS-I phase.

  10. Development and validation of a CCD-laser aerosol detective system for measuring the ambient aerosol phase function

    Science.gov (United States)

    Bian, Yuxuan; Zhao, Chunsheng; Xu, Wanyun; Zhao, Gang; Tao, Jiangchuan; Kuang, Ye

    2017-06-01

    Aerosol phase function represents the angular scattering property of aerosols, which is crucial for understanding the climate effects of aerosols that have been identified as one of the largest uncertainties in the evaluation of radiative forcing. So far, there is a lack of instruments with which to measure the aerosol phase function directly and accurately in laboratory studies and in situ measurements. A portable instrument with high angular range and resolution has been developed for the measurement of the phase function of ambient aerosols in this study. The charge-coupled device-laser aerosol detective system (CCD-LADS) measures the aerosol phase function both across a relatively wide angular range of 10-170° and at a high resolution of 0.1°. The system includes a continuous laser, two charge-coupled device cameras and the corresponding fisheye lenses. The CCD-LADS was validated by both a laboratory study and a field measurement. The comparison between the aerosol phase function retrieved from CCD-LADS and Mie-scattering model shows good agreement. Compared with the TSI polar nephelometer, CCD-LADS has the advantages of wider detection range and better stability.

  11. Bioelectrical impedance phase angle relates to function, disease severity and prognosis in stable chronic obstructive pulmonary disease.

    Science.gov (United States)

    Maddocks, Matthew; Kon, Samantha S C; Jones, Sarah E; Canavan, Jane L; Nolan, Claire M; Higginson, Irene J; Gao, Wei; Polkey, Michael I; Man, William D-C

    2015-12-01

    Bioelectrical impedance analysis (BIA) provides a simple method to assess changes in body composition. Raw BIA variables such as phase angle provide direct information on cellular mass and integrity, without the assumptions inherent in estimating body compartments, e.g. fat-free mass (FFM). Phase angle is a strong functional and prognostic marker in many disease states, but data in COPD are lacking. Our aims were to describe the measurement of phase angle in patients with stable COPD and determine the construct and discriminate validity of phase angle by assessing its relationship with established markers of function, disease severity and prognosis. 502 outpatients with stable COPD were studied. Phase angle and FFM by BIA, quadriceps strength (QMVC), 4-m gait speed (4MGS), 5 sit-to-stand time (5STS), incremental shuttle walk (ISW), and composite prognostic indices (ADO, iBODE) were measured. Patients were stratified into normal and low phase angle and FFM index. Phase angle correlated positively with FFM and functional outcomes (r = 0.35-0.66, p < 0.001) and negatively with prognostic indices (r = -0.35 to -0.48, p < 0.001). In regression models, phase angle was independently associated with ISW, ADO and iBODE whereas FFM was removed. One hundred and seventy patients (33.9% [95% CI, 29.9-38.1]) had a low phase angle. Phenotypic characteristics included lower QMVC, ISW, and 4MGS, higher 5STS, ADO and iBODE scores, and more exacerbations and hospital days in past year. The proportion of patients to have died was significantly higher in patients with low phase angle compared to those with normal phase angle (8.2% versus 3.6%, p = 0.02). Phase angle relates to markers of function, disease severity and prognosis in patients with COPD. As a directly measured variable, phase angle offers more useful information than fat-free mass indices. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  12. Diamino moiety functionalized silica nanoparticles as pseudostationary phase in capillary electrochromatography separation of plant auxins.

    Science.gov (United States)

    Li, Hui; Ding, Guo-Sheng; Yue, Chun-Yue; Tang, An-Na

    2012-07-01

    A novel and simple method for the preparation of silica nanoparticles having surface-functionalized diamino moiety (dASNPs) was reported in our paper and characterized using scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, and thermogravimetry techniques. To test this method practically, in this contribution we describe the enhanced separation of four plant auxins - indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), 2,4-dichlorophenoxyacetic acid (dCPAA), and 2-(1-naphthyl) acetic acid (NAA) - by capillary electrochromatography using diamino moiety functionalized silica nanoparticles as pseudostationary phase (PSP) in the running buffer. The effect of pH, buffer concentration, and diamino moiety functionalized silica nanoparticles concentration on the selectivity of separation was investigated. A combination of the nanoparticles and running buffer reversed the electroosmotic direction making possible the rapid and efficient separation of the auxins from the auxins migrated in the same direction with the EOF under optimum experimental conditions. A good resolution of four auxins was obtained within 5.5 min under optimum experimental conditions. The precision (RSD, n = 5) was in the range of 0.72-0.91% and 1.89-2.23% for migration time and peak area response, respectively. The detection limits were 0.48, 0.44, 0.46, and 0.42 μM for NAA, IBA, IAA, and dCPAA, respectively. Furthermore, the method was successfully tested for the determination of IAA in the grapes. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Density Functional Study of the Phase Diagram and Pressure-Induced Superconductivity in P: Implication for Spintronics

    Science.gov (United States)

    Ostanin, S.; Trubitsin, V.; Staunton, J. B.; Savrasov, S. Y.

    2003-08-01

    The high-pressure phase diagram of P is studied using density functional total energy, linear response lattice dynamics and model Debye-Grüneisen theories. The volume dependent electron-phonon coupling λ˜0.7 0.9 is extracted for the bcc structure and found to increase with increasing volume. We propose that this phase might be realized in epitaxial thin films using templates such as V(100), Fe(100), or Cr(100) relevant to spintronics applications.

  14. Engineering functionalized multi-phased silicon/silicon oxide nano-biomaterials to passivate the aggressive proliferation of cancer

    Science.gov (United States)

    Premnath, P.; Tan, B.; Venkatakrishnan, K.

    2015-01-01

    Currently, the use of nano silicon in cancer therapy is limited as drug delivery vehicles and markers in imaging, not as manipulative/controlling agents. This is due to limited properties that native states of nano silicon and silicon oxides offers. We introduce nano-functionalized multi-phased silicon/silicon oxide biomaterials synthesized via ultrashort pulsed laser synthesis, with tunable properties that possess inherent cancer controlling properties that can passivate the progression of cancer. This nanostructured biomaterial is composed of individual functionalized nanoparticles made of a homogenous hybrid of multiple phases of silicon and silicon oxide in increasing concentration outwards from the core. The chemical properties of the proposed nanostructure such as number of phases, composition of phases and crystal orientation of each functionalized nanoparticle in the three dimensional nanostructure is defined based on precisely tuned ultrashort pulsed laser-material interaction mechanisms. The amorphous rich phased biomaterial shows a 30 fold (95%) reduction in number of cancer cells compared to bulk silicon in 48 hours. Further, the size of the cancer cells reduces by 76% from 24 to 48 hours. This method exposes untapped properties of combination of multiple phases of silicon oxides and its applications in cancer therapy. PMID:26190009

  15. Density-functional theory for f-electron systems. The α-γ phase transition in cerium

    International Nuclear Information System (INIS)

    Casadei, Marco

    2013-01-01

    Rare earths are technologically important and scientifically highly interesting elements. The description of the volume collapse exhibited by some rare earth metals poses a great challenge to density-functional theory (DFT) since local/semi-local functionals (LDA/GGA) only partially capture the associated phase transitions. In this work this problem is approached by treating all electrons at the same quantum mechanical level, using both hybrid functionals (e.g. PBE0 and HSE06) and exact-exchange plus correlation in the random-phase approximation (EX+cRPA). The performance of recently developed beyond RPA schemes is also assessed. The isostructural α-γ phase transition in cerium is the most studied. The exact exchange contribution in PBE0 and HSE06 is crucial to produce two distinct solutions that can be associated with the α and γ phases. The two solutions emerge in bulk as well as in cluster calculations. Most notable is their presence in the cerium dimer. However, quantitative agreement with the extrapolated phase diagram requires EX+cRPA. So far the EX+cRPA correction can only be applied to cerium clusters and not to the bulk. A cluster of 19 atoms cut from the fcc crystal structure (the same that characterizes the α and γ phases) was therefore determined as representative. (EX+cRPA) rate at PBE0 for Ce 19 provides good agreement with the extrapolated transition pressure to zero temperature. We predict that a pressure induced phase transition should exist at or close to zero. A finite temperature phase diagram can be drawn in reasonable agreement with experiment by adding entropic effects. The cerium neighbors are also studied: lanthanum, which has no f electrons, praseodymium, with three f electrons and a volume collapse, and neodymium, with four f electrons and no volume collapse. Multiple solutions are also present for these f electron elements, confirming the importance of exact-exchange for f electron systems.

  16. Theoretical study of the structural stability for fcc-CHx phases using density functional theory

    Directory of Open Access Journals (Sweden)

    M Dadsetani

    2011-09-01

    Full Text Available  Recently, a new carbon modification, namly n-diamond, have been reported, whose structure is still a matter of debate. It is important to note that the synthesis of n-diamond was carried out in the presence of hydrogen or methan. In this work we evaluate the structural stability of five fcc-CHx phases by means of first-principle calculation. The total energy is obtained as a function of the isotropic, tetragonal and rhombohedral deformations for the bulk structures. First, we analyze the C2H (cuprite, CH (zincblende, CH (rocksalt and CH2 (fluorite structures.It is found that the four systems show a minimum in the total energy for the isotropic and rhombohedral deformations, but are unstable against tetragonal deformation. In the second part, we explore the structural stability of CH2 in the pyrite structure. We find that CH2 (pyrite with the hydrogen atoms defined by the internal parameter u=0.35 and a lattice parameter of 3.766 Å is elastically stable, providing a possible explanation for the experimental observation of fcc-carbon in materials prepared in the presence of hydrogen or methan. In final, we calculate density of states, band structure and EELS spectrum of CH2 (pyrite and compare them with n-diamond.

  17. Chronic radiation-induced leukemogenesis: alterations of hematopoietic progenitor repair functions during preclinical phases

    International Nuclear Information System (INIS)

    Seed, T.M.; Kaspar, L.V.; Grdina, D.J.; Frazier, M.E.

    1987-01-01

    Chronic exposure to low daily doses of whole-body gamma irradiation elicits a high incidence of myeloid leukemia (ML) and related myeloproliferative diseases (MPD) in beagles. Previously, the authors identified and partially characterized a four-phase sequence of evolving MPD as a consequence of chronic radiation exposure. With a focus on preclinical alterations in granulocyte/monocyte-committed stem cells, they have identified two critical events in the process: (i) an early event, involving the coupling of acquired radioresistance of the stem cell with renewed proliferative capacity; and (ii) a late event, involving acquired autocrine functions and associated change in stem cell clonality. In terms of the early event, repair-associated parameters are currently being examined on the cellular level by both split-dose and low dose-rate-type assays with survival enhancement used as the measured end point. On the molecular level, these parameters are examined by microfluorometric alkaline elution assays with DNA damage and repair used as end points

  18. Range-separated density-functional theory with random phase approximation applied to noncovalent intermolecular interactions.

    Science.gov (United States)

    Zhu, Wuming; Toulouse, Julien; Savin, Andreas; Angyán, János G

    2010-06-28

    Range-separated methods combining a short-range density functional with long-range random phase approximations (RPAs) with or without exchange response kernel are tested on rare-gas dimers and the S22 benchmark set of weakly interacting complexes of Jurecka et al. [Phys. Chem. Chem. Phys. 8, 1985 (2006)]. The methods are also compared to full-range RPA approaches. Both range separation and inclusion of the Hartree-Fock exchange kernel largely improve the accuracy of intermolecular interaction energies. The best results are obtained with the method called RSH+RPAx, which yields interaction energies for the S22 set with an estimated mean absolute error of about 0.5-0.6 kcal/mol, corresponding to a mean absolute percentage error of about 7%-9% depending on the reference interaction energies used. In particular, the RSH+RPAx method is found to be overall more accurate than the range-separated method based on long-range second-order Moller-Plesset (MP2) perturbation theory (RSH+MP2).

  19. Multifocus microscopy with precise color multi-phase diffractive optics applied in functional neuronal imaging.

    Science.gov (United States)

    Abrahamsson, Sara; Ilic, Rob; Wisniewski, Jan; Mehl, Brian; Yu, Liya; Chen, Lei; Davanco, Marcelo; Oudjedi, Laura; Fiche, Jean-Bernard; Hajj, Bassam; Jin, Xin; Pulupa, Joan; Cho, Christine; Mir, Mustafa; El Beheiry, Mohamed; Darzacq, Xavier; Nollmann, Marcelo; Dahan, Maxime; Wu, Carl; Lionnet, Timothée; Liddle, J Alexander; Bargmann, Cornelia I

    2016-03-01

    Multifocus microscopy (MFM) allows high-resolution instantaneous three-dimensional (3D) imaging and has been applied to study biological specimens ranging from single molecules inside cells nuclei to entire embryos. We here describe pattern designs and nanofabrication methods for diffractive optics that optimize the light-efficiency of the central optical component of MFM: the diffractive multifocus grating (MFG). We also implement a "precise color" MFM layout with MFGs tailored to individual fluorophores in separate optical arms. The reported advancements enable faster and brighter volumetric time-lapse imaging of biological samples. In live microscopy applications, photon budget is a critical parameter and light-efficiency must be optimized to obtain the fastest possible frame rate while minimizing photodamage. We provide comprehensive descriptions and code for designing diffractive optical devices, and a detailed methods description for nanofabrication of devices. Theoretical efficiencies of reported designs is ≈90% and we have obtained efficiencies of > 80% in MFGs of our own manufacture. We demonstrate the performance of a multi-phase MFG in 3D functional neuronal imaging in living C. elegans.

  20. High-accuracy phase-field models for brittle fracture based on a new family of degradation functions

    Science.gov (United States)

    Sargado, Juan Michael; Keilegavlen, Eirik; Berre, Inga; Nordbotten, Jan Martin

    2018-02-01

    Phase-field approaches to fracture based on energy minimization principles have been rapidly gaining popularity in recent years, and are particularly well-suited for simulating crack initiation and growth in complex fracture networks. In the phase-field framework, the surface energy associated with crack formation is calculated by evaluating a functional defined in terms of a scalar order parameter and its gradients. These in turn describe the fractures in a diffuse sense following a prescribed regularization length scale. Imposing stationarity of the total energy leads to a coupled system of partial differential equations that enforce stress equilibrium and govern phase-field evolution. These equations are coupled through an energy degradation function that models the loss of stiffness in the bulk material as it undergoes damage. In the present work, we introduce a new parametric family of degradation functions aimed at increasing the accuracy of phase-field models in predicting critical loads associated with crack nucleation as well as the propagation of existing fractures. An additional goal is the preservation of linear elastic response in the bulk material prior to fracture. Through the analysis of several numerical examples, we demonstrate the superiority of the proposed family of functions to the classical quadratic degradation function that is used most often in the literature.

  1. Applications of the phase function method ideas for the investigation of the two- and three-body system properties

    International Nuclear Information System (INIS)

    Petrov, N.M.; Pushkash, A.M.

    1985-01-01

    In accordance with the main idea of the phase function method the two-body off-shell scattering amplitudes are considered as the limit of the scattering amplitude sequence corresponding to the sequence of the R-radius cut-off potentials. The explicit analytical expression for the scattering amplitudes function is obtained in the case of separable potentials, due to which the three-body problem is investigated

  2. The transformation of amorphous calcium carbonate, ACC, to crystalline phases as function of time and temperature.

    Science.gov (United States)

    Gies, Hermann; Happel, Marian; Niedermayr, Andrea; Immenhauser, Adrian

    2017-04-01

    We present results from a structural study of the transformation of freeze dried amorphous calcium carbonate, ACC, in crystalline material using pair distribution function analysis, PDF analysis, of X-ray powder diffraction data, XPD data. PDF analysis allows for the analysis of local order of structural subunit in the range between molecular unit (1. and 2. coordination sphere) and long range periodicity as in crystalline materials. ACC was precipitated from aqueous solutions at 298 K and 278 K using different amounts of Mg cations as stabilizer. The samples were immediately separated from the solution and freeze dried. For the transformation study, the samples were heated and analysed using XPD until they were crystallized. The radial distribution obtained from the XPD data were compared to simulated radial distributions of the calcium carbonate polymorphs and their hydrated phases. An ACC precipitated from a solution with Ca:Mg:CO3 = 1:5:4 at 298 K (ration in mmol, pH = 8.2) and freeze dried right after isolation from the solution revealed a close resemblance with ikaite in its local order. Another ACC with Ca:Mg:CO3 = 1:10:1.4 (T = 298, pH = 8.7) showed distinctly different local order resembling monohydrocalcite. Both ACC, however, still had considerable amounts of water dominating the Ca-coordination sphere. During the transformation to calcite, the structural changes in the sample concerned the hydrate water coordinating Ca which was removed and replaced by the carbonate oxygens. The study shows that ACC obtained from different starting solutions show specific local order. Freeze drying leads to solid ACC powder which still contain considerable amounts of hydrate water. Structural subunits are distinct in ACC and different from the crystalline phase. The study supplements recent reports presented by Konrad et al., Purgstaller et al., and Tobler et al.. F. Konrad et al., Cryst. Growth Des. 16, 6310-6317(2016) B. Purgstaller et al., Geochimica et Cosmochimica

  3. Modeling the bidirectional reflectance distribution function of mixed finite plant canopies and soil

    Science.gov (United States)

    Schluessel, G.; Dickinson, R. E.; Privette, J. L.; Emery, W. J.; Kokaly, R.

    1994-01-01

    An analytical model of the bidirectional reflectance for optically semi-infinite plant canopies has been extended to describe the reflectance of finite depth canopies contributions from the underlying soil. The model depends on 10 independent parameters describing vegetation and soil optical and structural properties. The model is inverted with a nonlinear minimization routine using directional reflectance data for lawn (leaf area index (LAI) is equal to 9.9), soybeans (LAI, 2.9) and simulated reflectance data (LAI, 1.0) from a numerical bidirectional reflectance distribution function (BRDF) model (Myneni et al., 1988). While the ten-parameter model results in relatively low rms differences for the BRDF, most of the retrieved parameters exhibit poor stability. The most stable parameter was the single-scattering albedo of the vegetation. Canopy albedo could be derived with an accuracy of less than 5% relative error in the visible and less than 1% in the near-infrared. Sensitivity were performed to determine which of the 10 parameters were most important and to assess the effects of Gaussian noise on the parameter retrievals. Out of the 10 parameters, three were identified which described most of the BRDF variability. At low LAI values the most influential parameters were the single-scattering albedos (both soil and vegetation) and LAI, while at higher LAI values (greater than 2.5) these shifted to the two scattering phase function parameters for vegetation and the single-scattering albedo of the vegetation. The three-parameter model, formed by fixing the seven least significant parameters, gave higher rms values but was less sensitive to noise in the BRDF than the full ten-parameter model. A full hemispherical reflectance data set for lawn was then interpolated to yield BRDF values corresponding to advanced very high resolution radiometer (AVHRR) scan geometries collected over a period of nine days. The resulting parameters and BRDFs are similar to those for the

  4. Multi-functional Nano-Reinforced Self-Healing Polymer Matrix Composites, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project seeks to develop self-healing composites using carbon nanofibers in conjunction with encapsulated...

  5. The liquid phase epitaxy method for the construction of oriented ZIF-8 thin films with controlled growth on functionalized surfaces

    KAUST Repository

    Shekhah, Osama

    2013-01-01

    Highly-oriented ZIF-8 thin films with controllable thickness were grown on an -OH-functionalized Au substrate using the liquid phase epitaxy method at room temperature, as evidenced by SEM and PXRD. The adsorption-desorption properties of the resulting ZIF-8 thin film were investigated for various VOCs using the QCM technique. © The Royal Society of Chemistry 2013.

  6. Phase transitions of titanite CaTiSiO5 from density functional perturbation theory

    Science.gov (United States)

    Malcherek, Thomas; Fischer, Michael

    2018-02-01

    Phonon dispersion of titanite CaTiSiO5 has been calculated using the variational density functional perturbation theory. The experimentally known out-of-center distortion of the Ti atom is confirmed. The distortion is associated with a Bu mode that is unstable for wave vectors normal to the octahedral chain direction of the C 2 /c aristotype structure. The layer of wave vectors with imaginary mode frequencies also comprises the Brillouin zone boundary point Y (0 ,1 ,0 ) , which is critical for the transition to the P 21/c ground-state structure. The phonon branch equivalent to the imaginary branch of the titanite aristotype is found to be stable in malayaite CaSnSiO5. The unstable phonon mode in titanite leads to the formation of transoriented short and long Ti-O1 bonds. The Ti as well as the connecting O1 atom exhibit strongly anomalous Born effective charges along the octahedral chain direction [001], indicative of the strong covalency in this direction. Accordingly and in contrast to malayaite, LO-TO splitting is very large in titanite. In the C 2 /c phase of titanite, the Ti-O1-Ti distortion chain is disordered with respect to neighboring distortion chains, as all chain configurations are equally unstable along the phonon branch. This result is in agreement with diffuse x-ray scattering in layers normal to the chain direction that is observed at temperatures close to the P 21/c to C 2 /c transition temperature and above. The resulting dynamic chains of correlated Ti displacements are expected to order in two dimensions to yield the P 21/c ground-state structure of titanite.

  7. Gas-phase ion-mobility characterization of SAM-functionalized Au nanoparticles.

    Science.gov (United States)

    Tsai, D-H; Zangmeister, R A; Pease, L F; Tarlov, M J; Zachariah, M R

    2008-08-19

    We present results of a systematic examination of functionalized gold nanoparticles (Au-NPs) by electrospray-differential mobility analysis (ES-DMA). Commercially available, citrate-stabilized Au colloid solutions (10-60 nm) were sized using ES-DMA, from which changes in particle size of less than 0.3 nm were readily discerned. It was found that the formation of salt particles and the coating of Au-NPs by salt during the electrospray process can interfere with the mobility analysis, which required the development of sample preparation and data correction protocols to extract correct values for the Au-NP size. Formation of self-assembled monolayers (SAMs) of alkanethiol molecules on the Au-NP surface was detected from a change in particle mobility, which could be modeled to extract the surface packing density of SAMs. A gas-phase temperature-programmed desorption (TPD) kinetic study of SAMs on Au-NPs found the data to be consistent with a second-order Arrhenius-based rate law, yielding an Arrhenius factor of 1.0 x 10 (11) s (-1) and an activation energy approximately 105 kJ/mol. For the size range of SAM-modified Au-NP we considered, the effect of surface curvature on the energetics of binding of carboxylic acid terminated SAMs is evidently negligible, with binding energies determined by TPD agreeing with those reported for the same SAMs on planar surfaces. This study suggests that the ES-DMA can be added to the tool set of characterization methods used to study the structure and properties of coated nanoparticles.

  8. Re-examining the effect of particle phase functions on the remote-sensing reflectance.

    Science.gov (United States)

    Xiong, Yuanheng; Zhang, Xiaodong; He, Shuangyan; Gray, Deric J

    2017-08-20

    Even though it is well known that both the magnitude and detailed angular shape of scattering (phase function, PF), particularly in the backward angles, affect the color of the ocean, the current remote-sensing reflectance (R rs ) models typically account for the effect of its magnitude only through the backscattering coefficient (b b ). Using 116 volume scattering function (VSF) measurements previously collected in three coastal waters around the U.S. and in the water of the North Atlantic Ocean, we re-examined the effect of particle PF on R rs in four scenarios. In each scenario, the magnitude of particle backscattering (i.e., b bp ) is known, but the knowledge on the angular shape of particle backscattering is assumed to increase from knowing nothing about the shape of particle PFs to partially knowing the particle backscattering ratio (B p ), the exact backscattering shape as defined by β˜ p (γ≥90°) (particle VSF normalized by the particle total scattering coefficient), and the exact backscattering shape as defined by the χ p factor (particle VSF normalized by the particle backscattering coefficient). At sun zenith angle=30°, the nadir-viewed R rs would vary up to 65%, 35%, 20%, and 10%, respectively, as the constraints on the shape of particle backscattering become increasingly stringent from scenarios 1 to 4. In all four scenarios, the R rs variations increase with both viewing and sun angles and are most prominent in the direction opposite the sun. Our results show a greater impact of the measured particle PFs on R rs than previously found, mainly because our VSF data show a much greater variability in B p , β˜ p (γ≥90°), and χ p than previously known. Among the uncertainties in R rs due to the particle PFs, about 97% can be explained by χ p , 90% by β˜ p (γ≥90°), and 27% by B p . The results indicate that the uncertainty in ocean color remote sensing can be significantly constrained by accounting for χ p of the VSFs.

  9. Moshinsky atom and density functional theory - A phase space view(1)

    DEFF Research Database (Denmark)

    Dahl, Jens Peder

    2009-01-01

    Le probleme de deux particules dans un potentiel d'oscillateur harmonique commun interagissant par le biais de forces d'oscillateur harmonique est discute dans la representation phase-espace de Weyl-Wigner. La fonction de Wigner du systeme est une fonction ordinaire des constantes phase-espace du...

  10. Consistent Atomic Geometries and Electronic Structure of Five Phases of Potassium Niobate from Density-Functional Theory

    Directory of Open Access Journals (Sweden)

    Falko Schmidt

    2017-01-01

    Full Text Available We perform a comprehensive theoretical study of the structural and electronic properties of potassium niobate (KNbO3 in the cubic, tetragonal, orthorhombic, monoclinic, and rhombohedral phase, based on density-functional theory. The influence of different parametrizations of the exchange-correlation functional on the investigated properties is analyzed in detail, and the results are compared to available experimental data. We argue that the PBEsol and AM05 generalized gradient approximations as well as the RTPSS meta-generalized gradient approximation yield consistently accurate structural data for both the external and internal degrees of freedom and are overall superior to the local-density approximation or other conventional generalized gradient approximations for the structural characterization of KNbO3. Band-structure calculations using a HSE-type hybrid functional further indicate significant near degeneracies of band-edge states in all phases which are expected to be relevant for the optical response of the material.

  11. Assessing statistical significance of phase synchronization index - An application to study baroreflex function in critically-ill infants

    Science.gov (United States)

    Govindan, R. B.; Al-Shargabi, Tareq; Andescavage, Nickie N.; Metzler, Marina; Lenin, R. B.; Plessis, Adré du

    2017-01-01

    Phase differences of two signals in perfect synchrony exhibit a narrow band distribution, whereas the phase differences of two asynchronous signals exhibit uniform distribution. We assess the statistical significance of the phase synchronization between two signals by using a signed rank test to compare the distribution of their phase differences to the theoretically expected uniform distribution for two asynchronous signals. Using numerical simulation of a second order autoregressive (AR2) process, we show that the proposed approach correctly identifies the coupling between the AR2 process and the driving white noise. We also identify the optimal p-value that distinguishes coupled scenarios from uncoupled ones. To identify the limiting cases, we study the phase synchronization between two independent white noises as a function of bandwidth of the filter in a different second simulation. We identify the frequency bandwidth below which the proposed approach fails and suggest using a data-driven approach for those scenarios. Finally, we demonstrate the application of this approach to study the coupling between beat-to-beat cardiac intervals and continuous blood pressure obtained from critically-ill infants to characterize the baroreflex function.

  12. Application of radial basis function in densitometry of stratified regime of liquid-gas two phase flows

    International Nuclear Information System (INIS)

    Roshani, G.H.; Nazemi, E.; Roshani, M.M.

    2017-01-01

    In this paper, a novel method is proposed for predicting the density of liquid phase in stratified regime of liquid-gas two phase flows by utilizing dual modality densitometry technique and artificial neural network (ANN) model of radial basis function (RBF). The detection system includes a 137 Cs radioactive source and two NaI(Tl) detectors for registering transmitted and scattered photons. At the first step, a Monte Carlo simulation model was utilized to obtain the optimum position for the scattering detector in dual modality densitometry configuration. At the next step, an experimental setup was designed based on obtained optimum position for detectors from simulation in order to generate the required data for training and testing the ANN. The results show that the proposed approach could be successfully applied for predicting the density of liquid phase in stratified regime of gas-liquid two phase flows with mean relative error (MRE) of less than 0.701. - Highlights: • Density of liquid phase in stratified regime of two phase flows was predicted. • Combination of dual modality densitometry technique and ANN was utilized. • Detection system includes a 137 Cs radioactive source and two NaI(Tl) detectors. • MCNP simulation was done to obtain the optimum position for the scattering detector. • An experimental setup was designed to generate the required data for training the ANN.

  13. Time dependent density functional study of the absorption spectra of 1,3-benzoxazole and three substituted benzoxazole in gas phase and liquid phase

    Energy Technology Data Exchange (ETDEWEB)

    Carrasquilla, Rafael J; Neira, Oscar L, E-mail: rjcarrasquilla@yahoo.com [Grupo de Espectroscopia Optica y Laser, Universidad Popular del Cesar, Valledupar (Colombia)

    2011-01-01

    Time dependent density functional (TD-DFT) calculations were performed on 1,3-benzoxazole and substituted benzoxazoles using the B3LYP functional and the 6-31+G(d) basis sets. The geometry of the S{sub 0} and S{sub 1} singlet ground and excited states were optimized in gas phase, toluene and methanol using B3LYP/6-31+G(d) y CIS/6-31+G(d) methods, respectively, and the vertical {pi} {yields} {pi}{sup *} absorption largest wavelength transitions were determined. Several global molecular descriptors were considered such as the hardness, chemical potential, electronegativity and the dipole moment for each molecule and was determined the influence that has, about the values of these descriptors, the alteration of the main molecular chain of an initial structure (1,3 not substituted Benzoxazole). Generally, the predicted spectra are in agreement with the experimental data.

  14. Expressive Single Scattering for Light Shaft Stylization

    NARCIS (Netherlands)

    Kol, T.R.; Klehm, O.; Seidel, Hans-Peter; Eisemann, E.

    2017-01-01

    Light scattering in participating media is a natural phenomenon that is increasingly featured in movies and games, as it is visually pleasing and lends realism to a scene. In art, it may further be used to express a certain mood or emphasize objects. Here, artists often rely on stylization when

  15. Effects of Menstrual Phase on Pulmonary Function and Exercise Performance in Young Active Duty Women

    National Research Council Canada - National Science Library

    Hnatiuk, Oleh

    1996-01-01

    ....' However, if the APFT is given to female soldiers during a phase of their menstrual cycle when their ability to perform maximally is reduced, this critical test would not be an accurate reflection of true maximal performance level.

  16. Experimental study of coherence vortices: Local properties of phase singularities in a spatial coherence function

    DEFF Research Database (Denmark)

    Wang, W.; Duan, Z.H.; Hanson, Steen Grüner

    2006-01-01

    By controlling the irradiance of an extended quasimonochromatic, spatially incoherent source, an optical field is generated that exhibits spatial coherence with phase singularities, called coherence vortices. A simple optical geometry for direct visualization of coherence vortices is proposed, an...

  17. High Thermal Conductivity Functionally Graded Heat Sinks for High Power Packaging, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This NASA SBIR Phase I program proposes the development of a high thermal conductivity (400 W/mK), low coefficient of thermal expansion (7-10 ppm/?K), and light...

  18. Novel open tubular CEC with tentacle-type polymer stationary phase functionalized by phenylalanine.

    Science.gov (United States)

    Xu, Liang; Sun, Yan

    2008-02-01

    A novel stationary phase with tentacle-type polymer chains with epoxy groups was fabricated for open tubular CEC. The fabrication procedure of the stationary phase included pretreatment of capillary inner wall, silanization, and glycidyl methacrylate (GMA)-grafted polymerization. The influence of initiator concentration and polymerization time on the resulting polymer stationary phase was studied by measuring EOF mobility and hydrophobicity of the prepared capillary column. SEM showed that the capillary inner wall was evenly coated with a polymer film showing a wrinkly surface. The prepared GMA-grafted stationary phase could be easily modified with different chromatographic ligands by the ring-opening reaction of the epoxy groups. In this study, phenylalanine (Phe) was selected as the ligand. Benzene derivatives and three amino acids were then separated, respectively, using the Phe modified tentacle-type capillary column. As a control, separations were also performed on a monolayer Phe-modified capillary. The tentacle-type polymer stationary phase was found affording stronger retention and better resolution in the separation of benzene derivatives and tryptophan, tyrosine, and Phe mixtures compared with the monolayer stationary phase.

  19. Left ventricular regional myocardial motion and twist function in repaired tetralogy of Fallot evaluated by magnetic resonance tissue phase mapping

    International Nuclear Information System (INIS)

    Chang, Meng-Chu; Peng, Hsu-Hsia; Wu, Ming-Ting; Weng, Ken-Pen; Su, Mao-Yuan; Menza, Marius; Huang, Hung-Chieh

    2018-01-01

    We aimed to characterise regional myocardial motion and twist function in the left ventricles (LV) in patients with repaired tetralogy of Fallot (rTOF) and preserved LV global function. We recruited 47 rTOF patients and 38 age-matched normal volunteers. Tissue phase mapping (TPM) was performed for evaluating the LV myocardial velocity in longitudinal, radial, and circumferential (Vz, Vr, and VOe) directions in basal, middle, and apical slices. The VOe peak-to-peak (PTP) during systolic phases, the rotation angle of each slice, and VOe inconsistency were computed for evaluating LV twist function and VOe dyssynchrony. As compared to the controls, the rTOF patients presented decreased RV ejection fraction (RVEF) (p = 0.002) and preserved global LV ejection fraction (LVEF). They also demonstrated decreased systolic and diastolic Vz in several LV segments and higher diastolic Vr in the septum (all p < 0.05). A lower VOe PTP, higher VOe inconsistency, and reduced peak net rotation angle (all p < 0.05) were observed. The aforementioned indices demonstrated an altered LV twist function in rTOF patients in an early disease stage. MR TPM could provide information about early abnormalities of LV regional motion and twist function in rTOF patients with preserved LV global function. (orig.)

  20. Functional brain networks in Alzheimer's disease: EEG analysis based on limited penetrable visibility graph and phase space method

    Science.gov (United States)

    Wang, Jiang; Yang, Chen; Wang, Ruofan; Yu, Haitao; Cao, Yibin; Liu, Jing

    2016-10-01

    In this paper, EEG series are applied to construct functional connections with the correlation between different regions in order to investigate the nonlinear characteristic and the cognitive function of the brain with Alzheimer's disease (AD). First, limited penetrable visibility graph (LPVG) and phase space method map single EEG series into networks, and investigate the underlying chaotic system dynamics of AD brain. Topological properties of the networks are extracted, such as average path length and clustering coefficient. It is found that the network topology of AD in several local brain regions are different from that of the control group with no statistically significant difference existing all over the brain. Furthermore, in order to detect the abnormality of AD brain as a whole, functional connections among different brain regions are reconstructed based on similarity of clustering coefficient sequence (CCSS) of EEG series in the four frequency bands (delta, theta, alpha, and beta), which exhibit obvious small-world properties. Graph analysis demonstrates that for both methodologies, the functional connections between regions of AD brain decrease, particularly in the alpha frequency band. AD causes the graph index complexity of the functional network decreased, the small-world properties weakened, and the vulnerability increased. The obtained results show that the brain functional network constructed by LPVG and phase space method might be more effective to distinguish AD from the normal control than the analysis of single series, which is helpful for revealing the underlying pathological mechanism of the disease.

  1. Left ventricular regional myocardial motion and twist function in repaired tetralogy of Fallot evaluated by magnetic resonance tissue phase mapping

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Meng-Chu; Peng, Hsu-Hsia [National Tsing Hua University, Department of Biomedical Engineering and Environmental Sciences, Hsinchu (China); Wu, Ming-Ting [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung (China); National Yang-Ming University, Faculty of Medicine, Taipei (China); Weng, Ken-Pen [National Yang-Ming University, Faculty of Medicine, Taipei (China); Kaohsiung Veterans General Hospital, Department of Pediatrics, Kaohsiung (China); Shu-Zen Junior College of Medicine and Management, Department of Physical Therapy, Kaohsiung (China); Su, Mao-Yuan [National Taiwan University Hospital, Department of Medical Imaging, Taipei (China); Menza, Marius [Medical Center University of Freiburg, Faculty of Medicine, University of Freiburg, Department of Radiology, Medical Physics, Freiburg (Germany); Huang, Hung-Chieh [Kaohsiung Veterans General Hospital, Department of Radiology, Kaohsiung (China)

    2018-01-15

    We aimed to characterise regional myocardial motion and twist function in the left ventricles (LV) in patients with repaired tetralogy of Fallot (rTOF) and preserved LV global function. We recruited 47 rTOF patients and 38 age-matched normal volunteers. Tissue phase mapping (TPM) was performed for evaluating the LV myocardial velocity in longitudinal, radial, and circumferential (Vz, Vr, and VOe) directions in basal, middle, and apical slices. The VOe peak-to-peak (PTP) during systolic phases, the rotation angle of each slice, and VOe inconsistency were computed for evaluating LV twist function and VOe dyssynchrony. As compared to the controls, the rTOF patients presented decreased RV ejection fraction (RVEF) (p = 0.002) and preserved global LV ejection fraction (LVEF). They also demonstrated decreased systolic and diastolic Vz in several LV segments and higher diastolic Vr in the septum (all p < 0.05). A lower VOe PTP, higher VOe inconsistency, and reduced peak net rotation angle (all p < 0.05) were observed. The aforementioned indices demonstrated an altered LV twist function in rTOF patients in an early disease stage. MR TPM could provide information about early abnormalities of LV regional motion and twist function in rTOF patients with preserved LV global function. (orig.)

  2. Design of functional guanidinium ionic liquid aqueous two-phase systems for the efficient purification of protein

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Xueqin; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Zeng, Qun; Chen, Jing; Huang, Yanhua; Xu, Kaijia

    2014-03-01

    Graphical abstract: - Highlights: • A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been synthesized. • Functional guanidinium ionic liquid aqueous two-phase systems have been first designed for the purification of protein. • Mechanisms and performances of the process were researched. • Simple, green, safety and presents better purified ability than ordinary process. • A potential efficient platform for protein purification and related studies. - Abstract: A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been devised and synthesized based on 1,1,3,3-tetramethylguanidine. The structures of the ionic liquids (ILs) were confirmed by {sup 1}H nuclear magnetic resonance ({sup 1}H NMR) and 13C nuclear magnetic resonance (13C NMR) and the production yields were all above 90%. Functional guanidinium ionic liquid aqueous two-phase systems (FGIL-ATPSs) have been first designed with these functional guanidinium ILs and phosphate solution for the purification of protein. After phase separation, proteins had transferred into the IL-rich phase and the concentrations of proteins were determined by measuring the absorbance at 278 nm using an ultra violet visible (UV–vis) spectrophotometer. The advantages of FGIL-ATPSs were compared with ordinary ionic liquid aqueous two-phase systems (IL-ATPSs). The proposed FGIL-ATPS has been applied to purify lysozyme, trypsin, ovalbumin and bovine serum albumin. Single factor experiments were used to research the effects of the process, such as the amount of ionic liquid (IL), the concentration of salt solution, temperature and the amount of protein. The purification efficiency reaches to 97.05%. The secondary structure of protein during the experimental process was observed upon investigation using UV–vis spectrophotometer, Fourier-transform infrared

  3. Measurements of aerosol phase function and vertical backscattering coefficient using a charge-coupled device side-scatter lidar.

    Science.gov (United States)

    Tao, Zongming; Liu, Dong; Wang, Zhenzhu; Ma, Xiaomin; Zhang, Qingze; Xie, Chenbo; Bo, Guangyu; Hu, Shunxing; Wang, Yingjian

    2014-01-13

    By using a charge-coupled device (CCD) as the detector, side-scatter lidar has great potential applications in the near range atmospheric detection. A new inversion method is proposed for CCD side-scatter lidar (Clidar) to retrieve aerosol phase function and vertical backscattering coefficient. Case studies show the retrieved results from Clidar are in good agreements with those obtained from other instruments. It indicates that the new proposed inversion method is reliable and feasible and that the Clidar is practicable.

  4. Magnetic resonance tissue phase mapping demonstrates altered left ventricular diastolic function in children with chronic kidney disease.

    Science.gov (United States)

    Gimpel, Charlotte; Jung, Bernd A; Jung, Sabine; Brado, Johannes; Schwendinger, Daniel; Burkhardt, Barbara; Pohl, Martin; Odening, Katja E; Geiger, Julia; Arnold, Raoul

    2017-02-01

    Echocardiographic examinations have revealed functional cardiac abnormalities in children with chronic kidney disease. To assess the feasibility of MRI tissue phase mapping in children and to assess regional left ventricular wall movements in children with chronic kidney disease. Twenty pediatric patients with chronic kidney disease (before or after renal transplantation) and 12 healthy controls underwent tissue phase mapping (TPM) to quantify regional left ventricular function through myocardial long (Vz) and short-axis (Vr) velocities at all 3 levels of the left ventricle. Patients and controls (age: 8 years-20 years) were matched for age, height, weight, gender and heart rate. Patients had higher systolic blood pressure. No patient had left ventricular hypertrophy on MRI or diastolic dysfunction on echocardiography. Fifteen patients underwent tissue Doppler echocardiography, with normal z-scores for mitral early diastolic (V E ), late diastolic (V A ) and peak systolic (V S ) velocities. Throughout all left ventricular levels, peak diastolic Vz and Vr (cm/s) were reduced in patients: Vz base -10.6 ± 1.9 vs. -13.4 ± 2.0 (P children and adolescents. Children with chronic kidney disease show significantly reduced peak diastolic long- and short-axis left ventricular wall velocities, reflecting impaired early diastolic filling. Thus, tissue phase mapping detects chronic kidney disease-related functional myocardial changes before overt left ventricular hypertrophy or echocardiographic diastolic dysfunction occurs.

  5. Measurement of size-dependent single scattering albedo of fresh biomass burning aerosols using the extinction-minus-scattering technique with a combination of cavity ring-down spectroscopy and nephelometry

    Directory of Open Access Journals (Sweden)

    S. Singh

    2016-11-01

    Full Text Available Biomass burning (BB aerosols have a significant effect on regional climate, and represent a significant uncertainty in our understanding of climate change. Using a combination of cavity ring-down spectroscopy and integrating nephelometry, the single scattering albedo (SSA and Ångstrom absorption exponent (AAE were measured for several North American biomass fuels. This was done for several particle diameters for the smoldering and flaming stage of white pine, red oak, and cedar combustion. Measurements were done over a wider wavelength range than any previous direct measurement of BB particles. While the offline sampling system used in this work shows promise, some changes in particle size distribution were observed, and a thorough evaluation of this method is required. The uncertainty of SSA was 6 %, with the truncation angle correction of the nephelometer being the largest contributor to error. While scattering and extinction did show wavelength dependence, SSA did not. SSA values ranged from 0.46 to 0.74, and were not uniformly greater for the smoldering stage than the flaming stage. SSA values changed with particle size, and not systematically so, suggesting the proportion of tar balls to fractal black carbon change with fuel type/state and particle size. SSA differences of 0.15–0.4 or greater can be attributed to fuel type or fuel state for fresh soot. AAE values were quite high (1.59–5.57, despite SSA being lower than is typically observed in wildfires. The SSA and AAE values in this work do not fit well with current schemes that relate these factors to the modified combustion efficiency of a burn. Combustion stage, particle size, fuel type, and fuel condition were found to have the most significant effects on the intrinsic optical properties of fresh soot, though additional factors influence aged soot.

  6. Comparison of using distribution-specific versus effective radius methods for hydrometeor single-scattering properties for all-sky microwave satellite radiance simulations with different microphysics parameterization schemes

    Science.gov (United States)

    Sieron, Scott B.; Clothiaux, Eugene E.; Zhang, Fuqing; Lu, Yinghui; Otkin, Jason A.

    2017-07-01

    The Community Radiative Transfer Model (CRTM) presently uses one look-up table (LUT) of cloud and precipitation single-scattering properties at microwave frequencies, with which any particle size distribution may interface via effective radius. This may produce scattering properties insufficiently representative of the model output if the microphysics parameterization scheme particle size distribution mismatches that assumed in constructing the LUT, such as one being exponential and the other monodisperse, or assuming different particle bulk densities. The CRTM also assigns a 5 μm effective radius to all nonprecipitating clouds, an additional inconsistency. Brightness temperatures are calculated from 3 h convection-permitting simulations of Hurricane Karl (2010) by the Weather Research and Forecasting model; each simulation uses one of three different microphysics schemes. For each microphysics scheme, a consistent cloud scattering LUT is constructed; the use of these LUTs produces differences in brightness temperature fields that would be better for analyzing and constraining microphysics schemes than using the CRTM LUT as-released. Other LUTs are constructed which contain one of the known microphysics inconsistencies with the CRTM LUT as-released, such as the bulk density of graupel, but are otherwise microphysics-consistent; differences in brightness temperature to using an entirely microphysics-consistent LUT further indicate the significance of that inconsistency. The CRTM LUT as-released produces higher brightness temperature than using microphysics-consistent LUTs. None of the LUTs can produce brightness temperatures that can match well to observations at all frequencies, which is likely due in part to the use of spherical particle scattering.

  7. Phase-based vascular input function: Improved quantitative DCE-MRI of atherosclerotic plaques

    NARCIS (Netherlands)

    van Hoof, R. H. M.; Hermeling, E.; Truijman, M. T. B.; van Oostenbrugge, R. J.; Daemen, J. W. H.; van der Geest, R. J.; van Orshoven, N. P.; Schreuder, A. H.; Backes, W. H.; Daemen, M. J. A. P.; Wildberger, J. E.; Kooi, M. E.

    2015-01-01

    Purpose: Quantitative pharmacokinetic modeling of dynamic contrast-enhanced (DCE)-MRI can be used to assess atherosclerotic plaque microvasculature, which is an important marker of plaque vulnerability. Purpose of the present study was (1) to compare magnitude-versus phase-based vascular input

  8. Electroencephalogram Power Density and Slow Wave Sleep as a Function of Prior Waking and Circadian Phase

    NARCIS (Netherlands)

    Dijk, Derk-Jan; Brunner, Daniel P.; Beersma, Domien G.M.; Borbély, Alexander A.

    1990-01-01

    Human sleep electroencephalograms, recorded in four experiments, were subjected to spectral analysis. Waking prior to sleep varied from 12 to 36 h and sleep was initiated at different circadian phases. Power density of delta and theta frequencies in rapid-eye-movement (REM) sleep and non-REM (NREM)

  9. Functional-integral formulations for plasma instabilities and turbulence; analogies with phase-transition phenomena

    International Nuclear Information System (INIS)

    Arnold, R.C.

    1977-06-01

    The formalism of Martin, Siggia and Rose is utilized to write a functional-integral representation for generating functionals in plasma transport theory, following Nakayama and Dawson. Parallel treatments of Navier-Stokes turbulence (attempted by Rosen) and of critical dynamics, by Kawasaki, are compared to illustrate the application of common field-theory techniques, such as the effective action. Quasi-classical methods for functional integrals are discussed

  10. Prediction of upper limb recovery in the acute phase of cerebrovascular disease: evaluation of "functional hand" using the manual function test.

    Science.gov (United States)

    Sone, Toshimasa; Nakaya, Naoki; Iokawa, Kazuaki; Hasegawa, Keiichi; Tsukada, Tetsu; Kaneda, Mariko; Hamaguchi, Toyohiro; Suzuki, Kenji

    2015-04-01

    Prediction of upper limb function recovery in the acute phase of cerebrovascular disease can help clarify goal setting in rehabilitation and subsequently shorten hospital stay. The present study aimed to develop regression equations that can be used to predict the Manual Function Test (MFT) score 3 weeks after onset and to determine the optimal cutoff MFT score for the identification of "Functional Hand." In all, 190 patients with cerebrovascular disease were included in this study. The baseline survey performed within 1 week after onset assessed sociodemographic profiles, medical profiles, and acute symptoms. MFT was performed to determine the cutoff score to indicate Functional Hand. We used stepwise multiple regression analysis to establish the prediction equations with the best fit for the MFT score 3 weeks after onset. In addition, the sensitivity and specificity of the MFT as an indicator of Functional Hand with cutoff values were determined. The multiple regression analysis showed that the following factors had a significant influence on the MFT: Brunnstrom recovery stage, cognitive function, range of motion, age, and sensation. The area under the curve was .93 for the MFT score as an indicator of Functional Hand. The cutoff MFT score to identify Functional Hand was 22/21 points, with a sensitivity and specificity of 91.1% and 82.1%, respectively. Our findings helped develop regression equations that can be used to predict the MFT score 3 weeks after onset of cerebrovascular disease by evaluating factors reportedly associated with upper limb function recovery. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  11. Evaluation of mesoporous silicas functionalized with C18 groups as stationary phases for the solid-phase extraction of steroid hormones in milk.

    Science.gov (United States)

    Pérez-Fernández, Virginia; Morante-Zarcero, Sonia; Pérez-Quintanilla, Damián; García, María Ángeles; Marina, María Luisa; Alonso, Isabel Sierra

    2014-06-01

    In this work, two mesoporous silicas functionalized with C18 groups (SM-C18 and SBA-15-C18) have been synthesized for their evaluation as stationary phases in SPE for the extraction and preconcentration of seven steroid hormones (estrone, estradiol, estriol, ethinyl estradiol, diethylstilbestrol, testosterone, and progesterone ) from milk. The characterization of both materials by diverse techniques such as transmission electron microscopy, SEM, thermogravimetric analysis, X-ray diffraction, and adsorption-desorption isotherms showed that the mesoporous silicas had a high surface area, high pore volume, and a homogeneous distribution of the pores and that both silicas presented a similar degree of functionalization. An analytical methodology for the simultaneous separation of the seven selected steroids by HPLC-DAD was developed. Both silicas were evaluated as stationary phases in SPE for the extraction of the steroid hormones from milk. This HPLC-DAD method was applied to the analysis of all extracts obtained in the SPE experiments, showing that from the two synthesized mesoporus silicas, SBA-15-C18 silica enabled the extraction of the seven compounds with recoveries between 88 and 108% for all except for estriol, for which a recovery of 62% was obtained. The analytical characteristics of this methodology were evaluated, showing good precision and linearity (R2 > 0.994) for all analytes. The comparison of the results obtained with this silica and those obtained with commercial C18 particles and with some other commercial cartridges usually employed in the extraction of steroids showed that SBA-15-C18 silica was able to extract the seven steroids with higher recovery values. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Methodologies for verification and validation of expert systems as a function of component, criticality and life-cycle phase

    International Nuclear Information System (INIS)

    Miller, L.

    1992-01-01

    The review of verification and validation (V and V) methods presented here is based on results of the initial two tasks of a contract with the US Nuclear Regulatory Commission and the Electric Power Research Institute to Develop and Document Guidelines for Verifying and Validating Expert Systems. The first task was to review the applicability of conventional software techniques to expert systems; the second was to directly survey V and V practices associated with development of expert systems. Subsequent tasks will focus on selecting, synthesizing or developing V and V methods appropriate for the overall system, for specific expert systems components, and for different phases of the life-cycle. In addition, final guidelines will most likely be developed for each of three levels of expert systems: safety-related (systems whose functions directly relate to system safety, so-called safety-critical systems), important-to-safety (systems which support the critical safety functions), and non-safety (systems which are unrelated to safety functions). For the present purposes of categorizing and discussing various types of V and V methods, the authors simplify the life-cycle and consider only two aspects - systems validation phase. The authors identified a number of techniques for the first, combined, phase and two general classes of V and V techniques for the latter phase: static testing techniques, which do not involve execution of the system code, and dynamic testing techniques, which do. In the next two sections the author reviews first the applicability to expert systems of conventional V and V techniques and, second, the techniques expert system developers actually use. In the last section the authors make some general observations

  13. Testing of the functional garments with microencapsulated phase-change material in simulated high temperature conditions

    Directory of Open Access Journals (Sweden)

    Jovanović Dalibor B.

    2016-01-01

    Full Text Available An organic Phase Change Material (PCM possesses the ability to absorb and release large quantity of latent heat during a phase change process over a certain temperature range. This paper presents results related to thermo-physiological efficiency of special underwear with organic PCM integrated in textile through microencapsulation process. The efficiency of PCM underwear was tested through physiological examinations in simulated high-temperature conditions, where test-subjects were voluntarily exposed to heat stress tests wearing NBC protective suit with PCM underwear (option "THERM" and without it (option "NoTHERM". It can be concluded that wearing a PCM textile clothes under NBC protective suit, during physical activity in high-tempearture conditions, reduces sweating and alleviates heat stress manifested by increased core and skin temperature and heart rate values. [Projekat Ministarstva nauke Republike Srbije, br. TR34034

  14. Multi-phase functionalization of titanium for enhanced photon absorption in the vis-NIR region.

    Science.gov (United States)

    Thakur, Pooja; Tan, Bo; Venkatakrishnan, Krishnan

    2015-10-19

    Inadequate absorption of Near Infrared (NIR) photons by conventional silicon solar cells has been a major stumbling block towards the attainment of a high efficiency "full spectrum" solar cell. An effective enhancement in the absorption of such photons is desired as they account for a considerable portion of the tappable solar energy. In this work, we report a remarkable gain observed in the absorption of photons in the near infrared and visible region (400 nm-1000 nm) by a novel multi-phased oxide of titanium. Synthesised via a single step ultra-fast laser pulse interaction with pure titanium, characterisation studies have identified this oxide of titanium to be multi-phased and composed of Ti3O, (TiO.716)3.76 and TiO2 (rutile). Computed to have an average band gap value of 2.39 eV, this ultrafast laser induced multi-phased titanium oxide has especially exhibited steady absorption capability in the NIR range of 750-1000 nm, which to the best of our knowledge, was never reported before. The unique NIR absorption properties of the laser functionalised titanium coupled with the simplicity and versatility of the ultrafast laser interaction process involved thereby provides tremendous potential towards the photon sensitization of titanium and thereafter for the inception of a "full spectrum" solar device.

  15. Harvesting yeast (Saccharomyces cerevisiae) at different physiological phases significantly affects its functionality in bread dough fermentation.

    Science.gov (United States)

    Rezaei, Mohammad N; Dornez, Emmie; Jacobs, Pieter; Parsi, Anali; Verstrepen, Kevin J; Courtin, Christophe M

    2014-05-01

    Fermentation of sugars into CO2, ethanol and secondary metabolites by baker's yeast (Saccharomyces cerevisiae) during bread making leads to leavening of dough and changes in dough rheology. The aim of this study was to increase our understanding of the impact of yeast on dough related aspects by investigating the effect of harvesting yeast at seven different points of the growth profile on its fermentation performance, metabolite production, and the effect on critical dough fermentation parameters, such as gas retention potential. The yeast cells harvested during the diauxic shift and post-diauxic growth phase showed a higher fermentation rate and, consequently, higher maximum dough height than yeast cells harvested in the exponential or stationary growth phase. The results further demonstrate that the onset of CO2 loss from fermenting dough is correlated with the fermentation rate of yeast, but not with the amount of CO2 that accumulated up to the onset point. Analysis of the yeast metabolites produced in dough yielded a possible explanation for this observation, as they are produced in different levels depending on physiological phase and in concentrations that can influence dough matrix properties. Together, our results demonstrate a strong effect of yeast physiology at the time of harvest on subsequent dough fermentation performance, and hint at an important role of yeast metabolites on the subsequent gas holding capacity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Phase Stability in Cobalt-Based L12 Quaternary Intermetallics From Density Functional Theory

    Science.gov (United States)

    Earwood, William P.

    The effects of higher order alloying additions (Mo, Ti, Ta, Hf, Fe, V) on the phase stability of L12 (gamma') intermetallics have been studied via first-principles. A 32 atom special-quasi-random structure was used to mimic the experimentally observed solid solution sublattice. Density of states distributions were generated in order to directly observe the impact of alloying additions on the position of the pseudogap and number of states at the Fermi level. Charge density differences across the supercell were visualized to analyze changes in bonding behavior. The results indicate that substitutions of Ti, Ta, and Hf in place of the central W atom increase phase stability by lowering the number of states at the Fermi level and decreasing the energy of the pseudogap relative to the unperturbed structure. Additionally, these substitutions increase the directional nature of the bond with nearest neighbor Co atoms. In particular, Co-Al bonds are reinforced at the expense of adjacent Co-W bonds which is expected to prolong dissociation of Co-Al bonds. Substitution of Fe led to a pronounced decrease in phase stability and directional bonding, indicating its inability to stabilize the base configuration or increase the bonding strength. V and Mo substitutions maintained the parent electron distribution to a greater degree than Ti, Ta, Hf, or Fe. However, V was shown to decrease the energy of the pseudogap by a significant amount and resembled the proposed ?' stabilizers more so than Mo.

  17. Fabrication and characterization of dual-functional ultrafine composite fibers with phase-change energy storage and luminescence properties.

    Science.gov (United States)

    Xi, Peng; Zhao, Tianxiang; Xia, Lei; Shu, Dengkun; Ma, Menjiao; Cheng, Bowen

    2017-01-09

    Ultrafine composite fibers consisting of a thermoplastic polyurethane solid-solid phase-change material and organic lanthanide luminescent materials were prepared through a parallel electrospinning technique as an innovative type of ultrafine, dual-functional fibers containing phase-change and luminescent properties. The morphology and structure, thermal energy storage, and luminescent properties of parallel electrospun ultrafine fibers were investigated. Scanning electron microscopy (SEM) images showed that the parallel electrospun ultrafine fibers possessed the desired morphologies with smaller average fiber diameters than those of traditional mixed electrospun ultrafine fibers. Transmission electron microscopy (TEM) images revealed that the parallel electrospun ultrafine fibers were composed of two parts. Polymeric phase-change materials, which can be directly produced and spun, were used to provide temperature stability, while a mixture of polymethyl methacrylate and an organic lanthanide complex acted as the luminescent unit. Differential scanning calorimetry (DSC) and luminescence measurements indicated that the unique structure of the parallel electrospun ultrafine fibers provides the products with good thermal energy storage and luminescence properties. The fluorescence intensity and the phase-change enthalpy values of the ultrafine fibers prepared by parallel electrospinning were respectively 1.6 and 2.1 times those of ultrafine fibers prepared by mixed electrospinning.

  18. Real-time Estimation of UAS Performance Using Efficient Sampling of Functional Models, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Numerica proposes to developed advanced algorithms for constructing a UAS vehicle model from ATC surveillance data in real-time. Using functional descriptions of...

  19. Microwave-Assisted Functionalization of Carbon Nanotubes and Reactive Synthesis of Nanocomposites, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The Offerers will build on their recent innovation of a microwave-induced route to the rapid functionalization, solubilization and reactive synthesis of carbon...

  20. MF-CRA: Multi-Function Cognitive Radio Architecture for Space Communications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — EpiSys Science, Inc. and University of Arizona propose to develop, implement, and demonstrate Multi-Function Cognitive Radio Architecture (MF-CRA) for Space...

  1. Functionally Graded Polyimide Nanocomposite Foams for Ablative and Inflatable/Flexible/Deplorable Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the proposed research is to develop functionally graded polyimide foams as light-weight, high performance thermal protection systems (TPS) for...

  2. Functionalized polymer-based spherical activated carbon for liquid and gas phase applications

    International Nuclear Information System (INIS)

    Schrage, Christian; Modrow, Antje; Fichtner, Sven; Giebelhausen, Jann Michael; Boehringer, Bertram

    2014-01-01

    Polymer-based spherical activated carbon (PBSAC) can be functionalized through the integration of reactive compounds. This offers new fields of applications for this adsorbent material. Impregnated PBSAC can be used as broadband sorbent material for respiratory protection, and for removal of certain metals from water, while the integration of nitrogen leads to a material suitable for the clean-up of gases. Functionalization through oxidation or integration of nitrogen atoms enables the concentration of valuable resources like uranium or gold.

  3. Structure and property investigations of TDO in aqueous phase by density functional theory, UV absorption, and Raman spectroscopy.

    Science.gov (United States)

    Shao, Jianzhong; Liu, Xiaoyun; Chen, Pin; Wu, Qiuxia; Zheng, Xuming; Pei, Kemei

    2014-05-01

    Density functional theory, UV absorption, and Raman spectroscopy are used to investigate the structure and properties of TDO in aqueous solution. The equilibrium structures, UV absorption spectra, interaction energies, and Raman spectroscopy data of TDO, AIMSA, and 12 TDO or AIMSA clusters are calculated. Raman spectroscopy experiments are carried out by 488 and 208 nm laser excitation. The Raman spectra of TDO in solid and aqueous phases have been compared, and the most possible structure for TDO in aqueous phase was deduced from analysis of the DFT calculations for the examined models, the experimental UV absorption spectrum, and Raman spectra of TDO. The interaction energy results show that TDO's solubility in water is originated from the TDO-water cyclic oligomer. The calculated UV absorption and Raman spectra of the I2·2H2O-cyc cluster model agree with the experimental results of TDO in aqueous solution very well.

  4. Phase dependence of the unnormalized second-order photon correlation function

    Energy Technology Data Exchange (ETDEWEB)

    Ciornea, V.; Bardetski, P.; Macovei, M. A., E-mail: macovei@phys.asm.md [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of)

    2016-10-15

    We investigate the resonant quantum dynamics of a multi-qubit ensemble in a microcavity. Both the quantum-dot subsystem and the microcavity mode are pumped coherently. We find that the microcavity photon statistics depends on the phase difference of the driving lasers, which is not the case for the photon intensity at resonant driving. This way, one can manipulate the two-photon correlations. In particular, higher degrees of photon correlations and, eventually, stronger intensities are obtained. Furthermore, the microcavity photon statistics exhibits steady-state oscillatory behaviors as well as asymmetries.

  5. Affective symptoms and cognitive functions in the acute phase of Graves' thyrotoxicosis

    DEFF Research Database (Denmark)

    Vogel, Asmus; Elberling, Tina V; Hørding, Merete

    2007-01-01

    . No significant differences between the patient and the control group on neuropsychological test performances were found. Thyroid levels did not correlate with the neuropsychological test performances or psychiatric ratings. After reaching euthyroidism the level of affective symptoms (including reports......In the acute phase of Graves' thyrotoxicosis patients often have subjective cognitive complaints. Continuing controversy exists about the nature of these symptoms and whether they persist after treatment. This prospective study included 31 consecutively referred, newly diagnosed, and untreated....... Reports of cognitive dysfunction may reflect affective and somatic manifestations of thyrotoxicosis and in most patients these symptoms disappear after treatment of Graves' thyrotoxicosis....

  6. The Phase-locked loop Algorithm of the Function Generation Controller

    CERN Document Server

    Magrans De Abril, Marc; King, Quentin

    2015-01-01

    This paper describes the phase-locked loop algorithms that are used by the real-time power converter controllers at CERN. The algorithms allow the recovery of the machine time and events received by an embedded controller through WorldFIP or Ethernet-based fieldbuses. During normal operation, the algorithm provides less than 10 _s of time precision and 0.5 _s of clock jitter for the WorldFIP case, and less than 2.5 _s of time precision and 40 ns of clock jitter for the Ethernet case.

  7. A structural study of lamellar phases formed by nucleoside-functionalized lipids

    Energy Technology Data Exchange (ETDEWEB)

    Berti, D.; Fratini, E.; Baglioni, P. [Department of Chemistry and CSGI, University of Florence, Via G. Capponi 9, 50121 Florence (Italy); Dante, S.; Hauss, T. [Berlin Neutron Scattering Center, Hahn Meitner Institut, Glienicker Strasse 100, Wannsee, 14109 Berlin (Germany)

    2002-07-01

    We report a neutron-scattering investigation of lamellar phases formed by novel phospholipids bearing nucleosides at the polar-head-group region. These nucleolipids can interact through stacking and H-bond interactions, following a pattern that resembles base-base coupling in natural nucleic acids (DNA, RNA), i.e. they have similar recognition properties. Bilayer stacks formed of DPP-adenosine, DPP-uridine and their 1:1 mixture were investigated after equilibration in a 98% relative humidity atmosphere. The DPP-adenosine spectrum can be accounted for (in analogy to DPPC) by a lamellar phase with a smectic period of about 60 A. DPP-uridine displays a not so straightforward behavior that we have tentatively ascribed to the coexistence of lamellae with different smectic periods. In the 1:1 mixture the lamellar mesophase of DPP-uridine is retained, suggesting a specific interaction of the uridine polar-head group with the adenosine moiety of DPP-adenosine. It should be stressed that this behavior can be considered as an indication of the recognition process occurring at the polar-head-group region of the mixed phospholiponucleoside membrane. (orig.)

  8. A structural study of lamellar phases formed by nucleoside-functionalized lipids

    CERN Document Server

    Berti, D; Baglioni, P; Dante, S; Hauss, T

    2002-01-01

    We report a neutron-scattering investigation of lamellar phases formed by novel phospholipids bearing nucleosides at the polar-head-group region. These nucleolipids can interact through stacking and H-bond interactions, following a pattern that resembles base-base coupling in natural nucleic acids (DNA, RNA), i.e. they have similar recognition properties. Bilayer stacks formed of DPP-adenosine, DPP-uridine and their 1:1 mixture were investigated after equilibration in a 98% relative humidity atmosphere. The DPP-adenosine spectrum can be accounted for (in analogy to DPPC) by a lamellar phase with a smectic period of about 60 A. DPP-uridine displays a not so straightforward behavior that we have tentatively ascribed to the coexistence of lamellae with different smectic periods. In the 1:1 mixture the lamellar mesophase of DPP-uridine is retained, suggesting a specific interaction of the uridine polar-head group with the adenosine moiety of DPP-adenosine. It should be stressed that this behavior can be considere...

  9. Functionalized silica aerogels for gas-phase purification, sensing, and catalysis: A review

    Energy Technology Data Exchange (ETDEWEB)

    Amonette, James E.; Matyáš, Josef

    2017-09-01

    Silica aerogels have a rich history and a unique, fascinating gas-phase chemistry that has lent them to many diverse applications. This review starts with a brief discussion of the fundamental issues driving the movement of gases in silica aerogels and then proceeds to provide an overview of the work that has been done with respect to the purification of gases, sensing of individual gases, and uses of silica aerogels as catalysts for gas-phase reactions. Salient features of the research behind these different applications are presented, and, where appropriate, critical aspects that affect the practical use of the aerogels are noted. Specific sections under the gas-purification category focus on the removal of airborne nanoparticles, carbon dioxide, volatile organic compounds, sulfur gases and radioactive iodine from gas streams. The use of silica aerogels as sensors for humidity, oxygen, hydrocarbons, volatile acids and bases, various non-ammoniacal nitrogen gases, and viral particles is discussed. With respect to catalysis, the demonstrated use of silica aerogels as supports for oxidation, Fischer-Tropsch, alkane isomerization, and hydrogenation reactions is reviewed, along with a section on untested catalytic formulations involving silica aerogels. A short section focuses on recent developments in thermomolecular Knudsen compressor pumps using silica aerogel membranes. The review continues with an overview of the production methods, locations of manufacturing facilities globally, and a brief discussion of the economics before concluding with a few remarks about the present and future trends revealed by the work presented.

  10. Color Doppler indexes in early phase after kidney transplantation and their association with kidney function on six month follow up

    Directory of Open Access Journals (Sweden)

    Atoosa Adibi

    2012-01-01

    Full Text Available Background: Doppler ultrasonography (DU and measurement of its indexes, resistive index (RI and pulsatility index (PI, is used to investigate transplanted kidney hemodynamic status and function. The aim of this study was to determine the correlation between Doppler indexes in the early phase after transplantation with long-term transplanted kidney function. Materials and Methods : In this cross-sectional study on 38 newly kidney transplant patients, we performed DU with assessment of its indexes within 48 hours, 1 week, and 6 months after kidney transplantation. Serum creatinine after stability and 6 months after kidney transplantation were assessed. Cyclosporine level was measured 1 week after kidney transplantation and compared with DU indexes. Results: About 71% of kidney transplanted patients reached their normal initial creatinine level(cr<1.5 mg/ dl and 28% of all patients were involved in kidney dysfunction after 6 months (increase in basic creatinine level more than 25%.There was no significant difference between mean RI and PI in patients with normal and disturbed kidney function based on creatinine level in early posttransplantation period but there was linear correlation between mean RI and PI within 48 hours and 1 week with kidney function after 6 months. Also no association between cyclosporine level and RI and PI was shown. There was a direct association between age and the levels of RI and PI 6 months after transplantation. Conclusion: This study suggests assessment of RI and PI in early period after transplantation and can be used as predictive parameters for long-term function of transplanted kidney and RI more than 0.80 in early phase after transplantation has an acceptable sensitivity and specificity to predict long-term kidney dysfunction.

  11. Effects of montelukast sodium combined with pidotimod on acute phase protein and immune function in children with acute bronchitis

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2017-08-01

    Full Text Available Objective: To observe the effects of montelukast sodium combined with pidotimod on acute phase protein (APP and indexes of immunologic function in pediatric acute bronchitis treatment. Methods: A total of 180 cases children with acute bronchitis acted as research objects were randomly divided into control group (n=65 and observation group (n=63. On the basis of conventional therapy, control group was treated by plus pidotimod. On this base, observation group was treated with montelukast sodium. The changes of acute phase proteins (CRP, HP, a1-AAG and CER and immune function (CD3+ , CD4+ , CD8+ and CD4+ /CD8+ levels before and after treatment were observed after 2 months. Results: Before treatment, CRP, HP, a1-AAG, CER, CD3+ , CD4+ , CD8+ and CD4+ /CD8+ levels of two groups had no statistically significant difference; CRP, HP, a1-AAG, CER, and CD8+ levels of control and observation groups decreased significantly after treatment, the decreases of observation group were more obvious than that of control group, and the levels after treatment were significantly lower than that of control groups. The levels of CD3+ , CD4+ and CD4+ /CD8+ in two groups after treatment were significantly higher than those before treatment. For observation group, the levels of CD3+ , CD4+ and CD4+ /CD8+ increased more significantly after treatment, which were significantly higher than that of the control group. Conclusion: Using Montelukast sodium combined with pidotimod can effectively reduce the children's acute phase protein levels, improve immune function, which has clinical value for the treatment of children with acute bronchitis.

  12. The association between microhaemorrhages and post - traumatic functional outcome in the chronic phase after mild traumatic brain injury

    Energy Technology Data Exchange (ETDEWEB)

    Haan, S. de; Groot, J.C. de [University Medical Center Groningen, Department of Radiology, University of Groningen, Groningen (Netherlands); Jacobs, B.; Naalt, J. van der [University Medical Center Groningen, Department of Neurology, University of Groningen, Groningen (Netherlands)

    2017-10-15

    In the chronic phase after mild traumatic brain injury (mTBI), microhaemorrhages are frequently detected on magnetic resonance imaging (MRI). It is however unclear whether microhaemorrhages are associated with functional outcome and which MRI sequence is most appropriate to address this association. We aimed to determine the association between microhaemorrhages and functional outcome in the chronic posttraumatic phase after injury with the most suitable MRI sequence to address this association. One hundred twenty-seven patients classified with mTBI admitted to the outpatient clinic from 2008 to 2015 for persisting posttraumatic complaints were stratified according to the presence of MRI abnormalities (n = 63 (MRI+ group) and n = 64 without abnormalities (MRI- group)). For the detection of microhaemorrhages, susceptibility-weighted imaging (SWI) and T2* gradient recalled echo (T2*GRE) were used. The relation between the functional outcome (dichotomized Glasgow Outcome Scale Extended scores) and the number and localization of microhaemorrhages was analysed using binary logistic regression. SWI detected twice as many microhaemorrhages compared to T2*GRE: 341 vs. 179. Lesions were predominantly present in the frontal and temporal lobes. Unfavourable outcome was present in 67% of the MRI+ group with a significant association of total number of microhaemorrhages in the temporal cortical area on SWI (OR 0.43 (0.21-0.90) p = 0.02), with an explained variance of 44%. The number of microhaemorrhages was not correlated with the number of posttraumatic complaints. An unfavourable outcome in the chronic posttraumatic phase is associated with the presence and number of microhaemorrhages in the temporal cortical area. SWI is preferably used to detect these microhaemorrhages. (orig.)

  13. Scatter Correction with Combined Single-Scatter Simulation and Monte Carlo Simulation Scaling Improved the Visual Artifacts and Quantification in 3-Dimensional Brain PET/CT Imaging with15O-Gas Inhalation.

    Science.gov (United States)

    Magota, Keiichi; Shiga, Tohru; Asano, Yukari; Shinyama, Daiki; Ye, Jinghan; Perkins, Amy E; Maniawski, Piotr J; Toyonaga, Takuya; Kobayashi, Kentaro; Hirata, Kenji; Katoh, Chietsugu; Hattori, Naoya; Tamaki, Nagara

    2017-12-01

    In 3-dimensional PET/CT imaging of the brain with 15 O-gas inhalation, high radioactivity in the face mask creates cold artifacts and affects the quantitative accuracy when scatter is corrected by conventional methods (e.g., single-scatter simulation [SSS] with tail-fitting scaling [TFS-SSS]). Here we examined the validity of a newly developed scatter-correction method that combines SSS with a scaling factor calculated by Monte Carlo simulation (MCS-SSS). Methods: We performed phantom experiments and patient studies. In the phantom experiments, a plastic bottle simulating a face mask was attached to a cylindric phantom simulating the brain. The cylindric phantom was filled with 18 F-FDG solution (3.8-7.0 kBq/mL). The bottle was filled with nonradioactive air or various levels of 18 F-FDG (0-170 kBq/mL). Images were corrected either by TFS-SSS or MCS-SSS using the CT data of the bottle filled with nonradioactive air. We compared the image activity concentration in the cylindric phantom with the true activity concentration. We also performed 15 O-gas brain PET based on the steady-state method on patients with cerebrovascular disease to obtain quantitative images of cerebral blood flow and oxygen metabolism. Results: In the phantom experiments, a cold artifact was observed immediately next to the bottle on TFS-SSS images, where the image activity concentrations in the cylindric phantom were underestimated by 18%, 36%, and 70% at the bottle radioactivity levels of 2.4, 5.1, and 9.7 kBq/mL, respectively. At higher bottle radioactivity, the image activity concentrations in the cylindric phantom were greater than 98% underestimated. For the MCS-SSS, in contrast, the error was within 5% at each bottle radioactivity level, although the image generated slight high-activity artifacts around the bottle when the bottle contained significantly high radioactivity. In the patient imaging with 15 O 2 and C 15 O 2 inhalation, cold artifacts were observed on TFS-SSS images, whereas

  14. Novel functionalized polymeric fabric and fiber material as solid support for solid-phase synthesis and biomedical applications

    Science.gov (United States)

    Xiang, Bei

    The aim of the research is to develop novel polymer solid support by modifying or fabricating polymeric fibrous materials for peptide synthesis and biomedical applications. Originally chemical inert isotactic polypropylene (iPP) fabric was utilized and modified to serve as a functional flexible planar solid support for solid phase peptide synthesis. The modification was achieved through thermal initiated radical grafting polymerization using acrylic acid, poly (ethylene glycol) diacrylate as monomers, and benzoyl peroxide as radical initiator. The iPP fabric was successfully functionalized and possessing as high as 0.7mmol/g carboxylic acid groups. Peptide ligand LHPQF was successfully synthesized on the new functional planar support. Specific enzyme immobilization was fulfilled on the functional iPP fabric support. A commercially available ethylene-acrylic acid copolymer was made into ultrafine copolymer fiber bundles which are composed of nanofibers with diameters ranging from 200nm to 800nm. Various mixing ratios of copolymer/matrix materials were utilized to explore the effect on the final nanofiber physical properties including morphology and stability in solvents. The surface carboxylic acid groups were further converted to amino groups before the functional nanofibers can be applied in solid phase peptide synthesis. Two peptide ligands, LHPQF and HWRGWV, were also successfully synthesized on the nanofiber bundles. Streptavidin and human immunoglobulin G specific binding with the corresponding ligand which was anchored on the nanofibers was conducted successfully to illustrate the potential applications of the nanofiber materials in biomedical field. Further study on the dispersion of the ethylene-acrylic acid nanofiber bundles was pursued to take advantage of the super high active surface area of functional nanofibers. To manipulate the polymer nanofibers during synthesis and bio-assays, a technique was developed to controllably assemble and disperse the

  15. Insight as a social identity process in the evolution of psychosocial functioning in the early phase of psychosis.

    Science.gov (United States)

    Klaas, H S; Clémence, A; Marion-Veyron, R; Antonietti, J-P; Alameda, L; Golay, P; Conus, P

    2017-03-01

    Awareness of illness (insight) has been found to have contradictory effects for different functional outcomes after the early course of psychosis. Whereas it is related to psychotic symptom reduction and medication adherence, it is also associated with increased depressive symptoms. In this line, the specific effects of insight on the evolution of functioning over time have not been identified, and social indicators, such as socio-occupational functioning have barely been considered. Drawing from social identity theory we investigated the impact of insight on the development of psychosocial outcomes and the interactions of these variables over time. The participants, 240 patients in early phase of psychosis from the Treatment and Early Intervention in Psychosis Program (TIPP) of the University Hospital of Lausanne, Switzerland, were assessed at eight time points over 3 years. Cross-lagged panel analyses and multilevel analyses were conducted on socio-occupational and general functioning [Social and Occupational Functioning Assessment Scale (SOFAS) and Global Assessment of Functioning (GAF)] with insight, time and depressive symptoms as independent variables. Results from multilevel analyses point to an overall positive impact of insight on psychosocial functioning, which increases over time. Yet the cross-lagged panel analysis did not reveal a systematic positive and causal effect of insight on SOFAS and GAF scores. Depressive symptoms seem only to be relevant in the beginning of the treatment process. Our results point to a complex process in which the positive impact of insight on psychosocial functioning increases over time, even when considering depressive symptoms. Future studies and treatment approaches should consider the procedural aspect of insight.

  16. Enhanced proton conductivity of niobium phosphates by interfacing crystal grains with an amorphous functional phase

    DEFF Research Database (Denmark)

    Huang, Yunjie; Yu, Lele; Li, Haiyan

    2016-01-01

    Niobium phosphate is an interesting proton conductor operational in the intermediate temperature range. In the present work two forms of phosphates were prepared: an amorphous one with high specific area and a crystalline one with low specific surface area. Both phosphates exhibited very low prot...... the high surface area amorphous phosphate was used as the precursor. At 250 °C thus obtained niobium phosphate showed a high and stable conductivity of 0.03 S cm−1 under dry atmosphere and of 0.06 S cm−1 at a water partial pressure of 0.12 atm....... conductivities. An activation process was developed to convert the phosphates into crystal grains with a phosphorus rich amorphous phase along the grain boundaries. As a result, the obtained niobium phosphates showed considerably enhanced and stable proton conductivities. The activation effect was prominent when...

  17. Solution-phase synthesis of chromium-functionalized single-walled carbon nanotubes

    KAUST Repository

    Kalinina, Irina V.

    2015-03-01

    The solution phase reactions of single-walled carbon nanotubes (SWNTs) with Cr(CO)6 and benzene-Cr(CO)3 can lead to the formation of small chromium clusters. The cluster size can be varied from less than 1 nm to about 4 nm by increasing the reaction time. TEM images suggest that the clusters are deposited predominantly on the exterior walls of the nanotubes. TGA analysis was used to obtain the Cr content and carbon to chromium ratio in the Cr-complexed SWNTs. It is suggested that the carbon nanotube benzenoid structure templates the condensation of chromium atoms and facilitates the loss of carbon monoxide leading to well defined metal clusters.

  18. Seniority structure of the cranked shell model wave function and the pairing phase transition

    International Nuclear Information System (INIS)

    Wu, C.S.; Zeng, J.Y.; Center of Theoretical Physics, China Center of Advanced Science and Technology

    1989-01-01

    The accurate solutions to the low-lying eigenstates of the cranked shell model Hamiltonian are obtained by the particle-number-conserving treatment, in which a many-particle configuration truncation is adopted instead of the conventional single-particle level truncation. The variation of the seniority structures of low-lying eigenstates with rotational frequency ω is analyzed. The gap parameter of the yrast band decreases with ω very slowly, though the seniority structure has undergone a great change. It is suggested to use the seniority structure to indicate the possible pairing phase transition from a superconducting state to a normal state. The important blocking effects on the low-lying eigenstates are discussed

  19. Dynamic and static correlation functions in the inhomogeneous Hartree-Fock-state approach with random-phase-approximation fluctuations

    International Nuclear Information System (INIS)

    Lorenzana, J.; Grynberg, M.D.; Yu, L.; Yonemitsu, K.; Bishop, A.R.

    1992-11-01

    The ground state energy, and static and dynamic correlation functions are investigated in the inhomogeneous Hartree-Fock (HF) plus random phase approximation (RPA) approach applied to a one-dimensional spinless fermion model showing self-trapped doping states at the mean field level. Results are compared with homogeneous HF and exact diagonalization. RPA fluctuations added to the generally inhomogeneous HF ground state allows the computation of dynamical correlation functions that compare well with exact diagonalization results. The RPA correction to the ground state energy agrees well with the exact results at strong and weak coupling limits. We also compare it with a related quasi-boson approach. The instability towards self-trapped behaviour is signaled by a RPA mode with frequency approaching zero. (author). 21 refs, 10 figs

  20. Density functional formulation of the random-phase approximation for inhomogeneous fluids: Application to the Gaussian core and Coulomb particles.

    Science.gov (United States)

    Frydel, Derek; Ma, Manman

    2016-06-01

    Using the adiabatic connection, we formulate the free energy in terms of the correlation function of a fictitious system, h_{λ}(r,r^{'}), in which interactions λu(r,r^{'}) are gradually switched on as λ changes from 0 to 1. The function h_{λ}(r,r^{'}) is then obtained from the inhomogeneous Ornstein-Zernike equation and the two equations constitute a general liquid-state framework for treating inhomogeneous fluids. The two equations do not yet constitute a closed set. In the present work we use the closure c_{λ}(r,r^{'})≈-λβu(r,r^{'}), known as the random-phase approximation (RPA). We demonstrate that the RPA is identical with the variational Gaussian approximation derived within the field-theoretical framework, originally derived and used for charged particles. We apply our generalized RPA approximation to the Gaussian core model and Coulomb charges.

  1. Micro-fabricated semi-packed column for gas chromatography by using functionalized parylene as a stationary phase

    International Nuclear Information System (INIS)

    Nakai, T; Nishiyama, S; Shuzo, M; Delaunay, J-J; Yamada, I

    2009-01-01

    The conformal coating of effective stationary phases onto micro-fabricated columns having complex geometries such as semi-packed columns poses a real challenge. Here, we report for the first time the conformal coating of a semi-packed column with amino-functionalized parylene diX-AM (poly-aminomethyl-[2,2]-paracyclophane), which was found to be an effective stationary-phase material for the chromatography of short-retention-time compounds. A semi-packed column (consisting of a zigzag array of 30 µm square micro-pillars in a 1.0 m long, 180 µm wide and 230 µm deep channel) and an open tubular column (1.0 m long, 160 µm wide and 230 µm deep channel) used for comparison purposes were micro-fabricated on silicon that was subsequently coated with diX-AM parylene and thermally bonded. The chromatograms recorded on a commercial gas chromatograph demonstrated the usefulness of the conformal diX-AM coating as a stationary phase for semi-packed columns. The separation efficiency of the semi-packed column was found to be more than ten times that of the open tubular column

  2. APTS and rGO co-functionalized pyrenated fluorescent nanonets for representative vapor phase nitroaromatic explosive detection

    Science.gov (United States)

    Guo, Linjuan; Zu, Baiyi; Yang, Zheng; Cao, Hongyu; Zheng, Xuefang; Dou, Xincun

    2014-01-01

    For the first time, flexible PVP/pyrene/APTS/rGO fluorescent nanonets were designed and synthesized via a one-step electrospinning method to detect representative subsaturated nitroaromatic explosive vapor. The functional fluorescent nanonets, which were highly stable in air, showed an 81% quenching efficiency towards TNT vapor (~10 ppb) with an exposure time of 540 s at room temperature. The nice performance of the nanonets was ascribed to the synergistic effects induced by the specific adsorption properties of APTS, the fast charge transfer properties and the effective π-π interaction with pyrene and TNT of rGO. Compared to the analogues of TNT, the PVP/pyrene/APTS/rGO nanonets showed notable selectivity towards TNT and DNT vapors. The explored functionalization method opens up brand new insight into sensitive and selective detection of vapor phase nitroaromatic explosives.For the first time, flexible PVP/pyrene/APTS/rGO fluorescent nanonets were designed and synthesized via a one-step electrospinning method to detect representative subsaturated nitroaromatic explosive vapor. The functional fluorescent nanonets, which were highly stable in air, showed an 81% quenching efficiency towards TNT vapor (~10 ppb) with an exposure time of 540 s at room temperature. The nice performance of the nanonets was ascribed to the synergistic effects induced by the specific adsorption properties of APTS, the fast charge transfer properties and the effective π-π interaction with pyrene and TNT of rGO. Compared to the analogues of TNT, the PVP/pyrene/APTS/rGO nanonets showed notable selectivity towards TNT and DNT vapors. The explored functionalization method opens up brand new insight into sensitive and selective detection of vapor phase nitroaromatic explosives. Electronic supplementary information (ESI) available: Vapor pressure of TNT and its analogues, fluorescence quenching kinetics, fluorescence quenching efficiencies and additional SEM images. See DOI: 10.1039/c3nr04960d

  3. Polymer monoliths with chelating functionalities for solid phase extraction of metal ions from water.

    Science.gov (United States)

    Wang, Hongxia; Zhang, Haiyang; Lv, Yongqin; Svec, Frantisek; Tan, Tianwei

    2014-05-23

    Simple devices for the adsorption and preconcentration of metal ions comprising various monolithic polymers have been prepared by in situ polymerization within the 5.5cm long and 5.6mm i.d. polypropylene syringes. Poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith was modified with ethylenediamine to obtain the chelating material. The poly(butyl methacrylate-co-ethylene dimethacrylate) and poly(lauryl methacrylate-co-ethylene dimethacrylate) monoliths were first photografted with glycidyl methacrylate prior to functionalization with ethylenediamine. Alternatively, other chelating functionalities including poly(ethylene imines) varying in molecular weight and shape (linear and branched) as well as lysozyme were also attached to the monolithic supports. We found that the poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolith functionalized with ethylenediamine exhibited the best chelating properties characterized with rapid adsorption and a capacity of 111.2mg/g (537μmol/g) for Pb(2+), 38.1mg/g (649μmol/g) for Ni(2+), 69.9mg/g (1100μmol/g) for Cu(2+), and 188.9mg/g (3633μmol/g) for Cr(3+). The very fast desorption was then achieved using 1.0mol/L HNO3 as the eluent. An enrichment factor of 300 was observed for metal ions adsorbed from solutions containing 2ppb of the metal. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Magnetic resonance tissue phase mapping demonstrates altered left ventricular diastolic function in children with chronic kidney disease

    Energy Technology Data Exchange (ETDEWEB)

    Gimpel, Charlotte; Pohl, Martin [Medical Center - University of Freiburg, Department of General Pediatrics, Adolescent Medicine and Neonatology, Center for Pediatrics, Freiburg (Germany); Jung, Bernd A. [Inselspital Bern, Institute of Diagnostic, Interventional and Pediatric Radiology, Bern (Switzerland); Jung, Sabine [Medical Center - University of Freiburg, Department of Nuclear Medicine, Freiburg (Germany); Brado, Johannes; Odening, Katja E. [University Heart Center Freiburg, Department of Cardiology and Angiology I, Freiburg (Germany); Schwendinger, Daniel [University Children' s Hospital Zurich, Zurich (Switzerland); Burkhardt, Barbara [University Children' s Hospital Zurich, Pediatric Heart Center, Zurich (Switzerland); Geiger, Julia [University Children' s Hospital Zurich, Department of Radiology, Zurich (Switzerland); Northwestern University, Department of Radiology, Chicago, IL (United States); Arnold, Raoul [University Hospital Heidelberg, Department of Pediatric and Congenital Cardiology, Heidelberg (Germany)

    2017-02-15

    Echocardiographic examinations have revealed functional cardiac abnormalities in children with chronic kidney disease. To assess the feasibility of MRI tissue phase mapping in children and to assess regional left ventricular wall movements in children with chronic kidney disease. Twenty pediatric patients with chronic kidney disease (before or after renal transplantation) and 12 healthy controls underwent tissue phase mapping (TPM) to quantify regional left ventricular function through myocardial long (Vz) and short-axis (Vr) velocities at all 3 levels of the left ventricle. Patients and controls (age: 8 years - 20 years) were matched for age, height, weight, gender and heart rate. Patients had higher systolic blood pressure. No patient had left ventricular hypertrophy on MRI or diastolic dysfunction on echocardiography. Fifteen patients underwent tissue Doppler echocardiography, with normal z-scores for mitral early diastolic (V{sub E}), late diastolic (V{sub A}) and peak systolic (V{sub S}) velocities. Throughout all left ventricular levels, peak diastolic Vz and Vr (cm/s) were reduced in patients: Vz{sub base} -10.6 ± 1.9 vs. -13.4 ± 2.0 (P < 0.0003), Vz{sub mid} -7.8 ± 1.6 vs. -11 ± 1.5 (P < 0.0001), Vz{sub apex} -3.8 ± 1.6 vs. -5.3 ± 1.6 (P = 0.01), Vr{sub base} -4.2 ± 0.8 vs. -4.9 ± 0.7 (P = 0.01), Vr{sub mid} -4.7 ± 0.7 vs. -5.4 ± 0.7 (P = 0.01), Vr{sub apex} -4.7 ± 1.4 vs. -5.6 ± 1.1 (P = 0.05). Tissue phase mapping is feasible in children and adolescents. Children with chronic kidney disease show significantly reduced peak diastolic long- and short-axis left ventricular wall velocities, reflecting impaired early diastolic filling. Thus, tissue phase mapping detects chronic kidney disease-related functional myocardial changes before overt left ventricular hypertrophy or echocardiographic diastolic dysfunction occurs. (orig.)

  5. Magnetic resonance tissue phase mapping demonstrates altered left ventricular diastolic function in children with chronic kidney disease

    International Nuclear Information System (INIS)

    Gimpel, Charlotte; Pohl, Martin; Jung, Bernd A.; Jung, Sabine; Brado, Johannes; Odening, Katja E.; Schwendinger, Daniel; Burkhardt, Barbara; Geiger, Julia; Arnold, Raoul

    2017-01-01

    Echocardiographic examinations have revealed functional cardiac abnormalities in children with chronic kidney disease. To assess the feasibility of MRI tissue phase mapping in children and to assess regional left ventricular wall movements in children with chronic kidney disease. Twenty pediatric patients with chronic kidney disease (before or after renal transplantation) and 12 healthy controls underwent tissue phase mapping (TPM) to quantify regional left ventricular function through myocardial long (Vz) and short-axis (Vr) velocities at all 3 levels of the left ventricle. Patients and controls (age: 8 years - 20 years) were matched for age, height, weight, gender and heart rate. Patients had higher systolic blood pressure. No patient had left ventricular hypertrophy on MRI or diastolic dysfunction on echocardiography. Fifteen patients underwent tissue Doppler echocardiography, with normal z-scores for mitral early diastolic (V E ), late diastolic (V A ) and peak systolic (V S ) velocities. Throughout all left ventricular levels, peak diastolic Vz and Vr (cm/s) were reduced in patients: Vz base -10.6 ± 1.9 vs. -13.4 ± 2.0 (P < 0.0003), Vz mid -7.8 ± 1.6 vs. -11 ± 1.5 (P < 0.0001), Vz apex -3.8 ± 1.6 vs. -5.3 ± 1.6 (P = 0.01), Vr base -4.2 ± 0.8 vs. -4.9 ± 0.7 (P = 0.01), Vr mid -4.7 ± 0.7 vs. -5.4 ± 0.7 (P = 0.01), Vr apex -4.7 ± 1.4 vs. -5.6 ± 1.1 (P = 0.05). Tissue phase mapping is feasible in children and adolescents. Children with chronic kidney disease show significantly reduced peak diastolic long- and short-axis left ventricular wall velocities, reflecting impaired early diastolic filling. Thus, tissue phase mapping detects chronic kidney disease-related functional myocardial changes before overt left ventricular hypertrophy or echocardiographic diastolic dysfunction occurs. (orig.)

  6. Solving one-dimensional phase change problems with moving grid method and mesh free radial basis functions

    International Nuclear Information System (INIS)

    Vrankar, L.; Turk, G.; Runovc, F.; Kansa, E.J.

    2006-01-01

    Many heat-transfer problems involve a change of phase of material due to solidification or melting. Applications include: the safety studies of nuclear reactors (molten core concrete interaction), the drilling of high ice-content soil, the storage of thermal energy, etc. These problems are often called Stefan's or moving boundary value problems. Mathematically, the interface motion is expressed implicitly in an equation for the conservation of thermal energy at the interface (Stefan's conditions). This introduces a non-linear character to the system which treats each problem somewhat uniquely. The exact solution of phase change problems is limited exclusively to the cases in which e.g. the heat transfer regions are infinite or semi-infinite one dimensional-space. Therefore, solution is obtained either by approximate analytical solution or by numerical methods. Finite-difference methods and finite-element techniques have been used extensively for numerical solution of moving boundary problems. Recently, the numerical methods have focused on the idea of using a mesh-free methodology for the numerical solution of partial differential equations based on radial basis functions. In our case we will study solid-solid transformation. The numerical solutions will be compared with analytical solutions. Actually, in our work we will examine usefulness of radial basis functions (especially multiquadric-MQ) for one-dimensional Stefan's problems. The position of the moving boundary will be simulated by moving grid method. The resultant system of RBF-PDE will be solved by affine space decomposition. (author)

  7. Quantitative analysis of molecular interaction potentials of ionic liquid anions using multi-functionalized stationary phases in HPLC.

    Science.gov (United States)

    Cho, Chul-Woong; Stolte, Stefan; Ranke, Johannes; Preiss, Ulrich; Krossing, Ingo; Thöming, Jorg

    2014-08-04

    The molecular interaction potentials, including S (dipolarity/polarizability), A (hydrogen bonding acidity), and B (hydrogen bonding basicity), of anions are experimentally determined using multi-functionalized stationary phases in high-performance liquid chromatography (HPLC) systems. We employ three different multi-functionalized stationary phase columns (Obelisc R, Obelisc N, and Acclaim Trinity-P1) combined with two ingredients, namely, acetonitrile (ACN) and methanol (MeOH). These conditions can cause neutral, cationic, and anionic compounds to be retained. By using the retention characteristics of calibration compounds, including cations, anions, and neutral compounds, system parameters including the ionic interaction terms (zc Zc , za Za ) are evaluated using multiple linear regression, resulting in a standard deviation (SD) of 0.090-0.158 log units. Based on the system parameters and retention characteristics of the anions of interest, their molecular interaction potentials are characterized on the same scale for neutral and cationic molecules. Furthermore, to verify the determined molecular interaction potentials, we predict anion hydrophobicity. The results show that the determined S, A, and B, together with the computable descriptors E (excess molar refraction) and V (McGowan volume), can predict anion hydrophobicity with R(2) =0.982 and SD=0.167 (dimensionless). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Approaches to Improving Cardiac Structure and Function During and After an Acute Myocardial Infarction: Acute and Chronic Phases.

    Science.gov (United States)

    Kloner, Robert A; Dai, Wangde; Hale, Sharon L; Shi, Jianru

    2016-07-01

    While progress has been made in improving survival following myocardial infarction, this injury remains a major source of mortality and morbidity despite modern reperfusion therapy. While one approach has been to develop therapies to reduce lethal myocardial cell reperfusion injury, this concept has not translated to the clinics, and several recent negative clinical trials raise the question of whether reperfusion injury is important in humans undergoing reperfusion for acute ST segment elevation myocardial infarction. Therapy aimed at reducing myocardial cell death while the myocytes are still ischemic is more likely to further reduce myocardial infarct size. Developing new therapies to further reduce left ventricular remodeling after the acute event is another approach to preserving structure and function of the heart after infarction. Such therapy may include chronic administration of pharmacologic agents and/or therapies developed from the field of regenerative cardiology, including cellular or non-cellular materials such as extracellular matrix. The optimal therapy will be to administer agents that both reduce myocardial infarct size in the acute phase of infarction as well as reduce adverse left ventricular remodeling during the chronic or healing phase of myocardial infarction. Such a dual approach will help optimize the preservation of both cardiac structure and function. © The Author(s) 2015.

  9. Lidar inelastic multiple-scattering parameters of cirrus particle ensembles determined with geometrical-optics crystal phase functions.

    Science.gov (United States)

    Reichardt, J; Hess, M; Macke, A

    2000-04-20

    Multiple-scattering correction factors for cirrus particle extinction coefficients measured with Raman and high spectral resolution lidars are calculated with a radiative-transfer model. Cirrus particle-ensemble phase functions are computed from single-crystal phase functions derived in a geometrical-optics approximation. Seven crystal types are considered. In cirrus clouds with height-independent particle extinction coefficients the general pattern of the multiple-scattering parameters has a steep onset at cloud base with values of 0.5-0.7 followed by a gradual and monotonic decrease to 0.1-0.2 at cloud top. The larger the scattering particles are, the more gradual is the rate of decrease. Multiple-scattering parameters of complex crystals and of imperfect hexagonal columns and plates can be well approximated by those of projected-area equivalent ice spheres, whereas perfect hexagonal crystals show values as much as 70% higher than those of spheres. The dependencies of the multiple-scattering parameters on cirrus particle spectrum, base height, and geometric depth and on the lidar parameters laser wavelength and receiver field of view, are discussed, and a set of multiple-scattering parameter profiles for the correction of extinction measurements in homogeneous cirrus is provided.

  10. Value of MR phase-contrast flow measurements for functional assessment of pulmonary arterial hypertension

    International Nuclear Information System (INIS)

    Ley, Sebastian; Mereles, Derliz; Gruenig, Ekkehard; Puderbach, Michael; Schoeck, Helena; Eichinger, Monika; Ley-Zaporozhan, Julia; Fink, Christian; Kauczor, Hans-Ulrich

    2007-01-01

    Goals of our study were to compare the pulmonary hemodynamics between healthy volunteers and patients with pulmonary arterial hypertension (PAH) and correlate MR flow measurements with echocardiography. Twenty-five patients with PAH and 25 volunteers were examined at 1.5 T. Phase-contrast flow measurements were performed in the ascending aorta and pulmonary trunk, resulting in the following parameters: peak velocity (cm/s), average blood flow (l/min), time to peak velocity (ms), velocity rise gradient and pulmonary distensibility (cm 2 ). The bronchosystemic shunt was calculated. In PAH patients transthoracic echocardiography and right-heart catheterization (RHC) served as the gold standard. In comparison to volunteers, the PAH patients showed significantly reduced pulmonary velocities (P = 0.002), blood flow (P = 0.002) and pulmonary distensibility (P = 0.008). In patients, the time to peak velocity was shorter (P<0.001), and the velocity rise gradient was steeper (P = 0.002) than in volunteers. While in volunteers the peak velocity in the aorta was reached earlier, it was the reverse in patients. Patients showed a significant bronchosystemic shunt (P = 0.01). No meaningful correlation was found between MRI measurements and echocardiography or RHC. MRI is a feasible technique for the differentiation between PAH and volunteers. Further studies have to be conducted for the absolute calculation of pressure estimates. (orig.)

  11. Three-Phase Carbon Fiber Amine Functionalized Carbon Nanotubes Epoxy Composite: Processing, Characterisation, and Multiscale Modeling

    Directory of Open Access Journals (Sweden)

    Kamal Sharma

    2014-01-01

    Full Text Available The present paper discusses the key issues of carbon nanotube (CNT dispersion and effect of functionalisation on the mechanical properties of multiscale carbon epoxy composites. In this study, CNTs were added in epoxy matrix and further reinforced with carbon fibres. Predetermined amounts of optimally amine functionalised CNTs were dispersed in epoxy matrix, and unidirectional carbon fiber laminates were produced. The effect of the presence of CNTs (1.0 wt% in the resin was reflected by pronounced increase in Young’s modulus, inter-laminar shear strength, and flexural modulus by 51.46%, 39.62%, and 38.04%, respectively. However, 1.5 wt% CNT loading in epoxy resin decreased the overall properties of the three-phase composites. A combination of Halpin-Tsai equations and micromechanics modeling approach was also used to evaluate the mechanical properties of multiscale composites and the differences between the predicted and experimental values are reported. These multiscale composites are likely to be used for potential missile and aerospace structural applications.

  12. Inhibitory function of NKT cells during early induction phase of nickel allergy.

    Science.gov (United States)

    Okuno, Hironori; Satoh, Masashi; Takeuchi, Emiko; Eshima, Koji; Terashima, Masazumi; Komotori, Jun; Habu, Sonoko; Tamauchi, Hidekazu; Iwabuchi, Kazuya

    2016-07-01

    Until now, metal allergies have been regarded as a Th1-type immune response. However, because the contribution of a Th2-type immune response has been suggested by clinical findings, we previously examined the Th2-type immune response during the development of metal allergies using a GATA-3 transgenic (GATA-3 Tg) mouse model. As a result, a Th2-type immunization reaction was suggested to be involved in the early phase of metal allergies. Recently, the involvement of NKT cells in metal allergies has been suggested. We examined this possibility using the activation of NKT cells and an NKT cell-deficient mouse model to determine the contribution of NKT cells to nickel allergy in the present study. In NKT cell-deficient mice, ear swelling was remarkably increased, compared with that in control mice. Also, in mice that had been treated with α-galactosylceramide (α-GalCer) to activate NKT cells, the ear swelling response was remarkably inhibited, compared with that in untreated mice. These facts show that NKT cells are involved in the inhibition of nickel allergy-induced ear swelling responses. Copyright © 2016 Elsevier GmbH. All rights reserved.

  13. Quantum-dot systems prepared by 2D organization of nanoclusters preformed in the gas phase on functionalized substrates

    International Nuclear Information System (INIS)

    Perez, A; Bardotti, L; Prevel, B; Jensen, P; Treilleux, M; Melinon, P; Gierak, J; Faini, G; Mailly, D

    2002-01-01

    The low-energy cluster beam deposition (LECBD) technique is used to deposit gold nanoclusters preformed in the gas phase on functionalized graphite substrates (highly oriented pyrolitic graphite (HOPG)), to prepare 2D-organized arrays of cluster assembled dots. Functionalized HOPG substrates are obtained using the focused ion beam (FIB) nanoengraving technique to pattern 2D-organized arrays of defects (nanoholes, nanobumps) which act as traps for the diffusing clusters. Depending on the deposition conditions (nature, size and fluence of the deposited clusters) and the functionalized substrates (nature and size of the FIB-induced defects, geometry of the 2D array of defects and temperature during deposition) high-quality quantum-dot arrays can be obtained with well controlled and reproducible morphologies. Kinetic Monte Carlo simulations of the cluster deposition experiments on functionalized substrates allow us to obtain quite good fits of the experimental images performed by tapping mode atomic force microscopy (TMAFM), leading to systematic investigations of the best conditions to realize high-quality quantum dots systems. This combined top-down-bottom-up approach (LECBD-FIB) seems a promising method for preparing high-integration-density devices (∼Tbit cm -2 ) well suited for future applications to data storage, nanoelectronics, nano-optics, nanomagnetic systems

  14. New Bedform Phase Diagrams and Discriminant Functions for Formative Conditions of Bedforms in Open-Channel Flows

    Science.gov (United States)

    Ohata, Koji; Naruse, Hajime; Yokokawa, Miwa; Viparelli, Enrica

    2017-11-01

    Understanding of the formative conditions of fluvial bedforms is significant for both river management and geological studies. Diagrams showing bedform stability conditions have been widely used for the analyses of sedimentary structures. However, the use of discriminants to determine the boundaries of different bedforms regimes has not yet been explored. In this study, we use discriminant functions to describe formative conditions for a range of fluvial bedforms in a 3-D dimensionless parametric space. We do this by means of discriminant analysis using the Mahalanobis distance. We analyzed 3,793 available laboratory and field data and used these to produce new bedform phase diagrams. These diagrams employ three dimensionless parameters representing properties of flow hydraulics and sediment particles as their axes. The discriminant functions for bedform regimes proposed herein are quadratic functions of three dimensionless parameters and are expressed as curved surfaces in 3-D space. These empirical functions can be used to estimate paleoflow velocities from sedimentary structures. As an example of the reconstruction of hydraulic conditions, we calculated the paleoflow velocity of the 2011 Tohoku-Oki tsunami backwash flow from the sedimentary structures of the tsunami deposit. In so doing, we successfully reconstructed reasonable values of the paleoflow velocities.

  15. Design of Helical Capacitance Sensor for Holdup Measurement in Two-Phase Stratified Flow: A Sinusoidal Function Approach.

    Science.gov (United States)

    Lim, Lam Ghai; Pao, William K S; Hamid, Nor Hisham; Tang, Tong Boon

    2016-07-04

    A 360° twisted helical capacitance sensor was developed for holdup measurement in horizontal two-phase stratified flow. Instead of suppressing nonlinear response, the sensor was optimized in such a way that a 'sine-like' function was displayed on top of the linear function. This concept of design had been implemented and verified in both software and hardware. A good agreement was achieved between the finite element model of proposed design and the approximation model (pure sinusoidal function), with a maximum difference of ±1.2%. In addition, the design parameters of the sensor were analysed and investigated. It was found that the error in symmetry of the sinusoidal function could be minimized by adjusting the pitch of helix. The experiments of air-water and oil-water stratified flows were carried out and validated the sinusoidal relationship with a maximum difference of ±1.2% and ±1.3% for the range of water holdup from 0.15 to 0.85. The proposed design concept therefore may pose a promising alternative for the optimization of capacitance sensor design.

  16. Design of Helical Capacitance Sensor for Holdup Measurement in Two-Phase Stratified Flow: A Sinusoidal Function Approach

    Directory of Open Access Journals (Sweden)

    Lam Ghai Lim

    2016-07-01

    Full Text Available A 360° twisted helical capacitance sensor was developed for holdup measurement in horizontal two-phase stratified flow. Instead of suppressing nonlinear response, the sensor was optimized in such a way that a ‘sine-like’ function was displayed on top of the linear function. This concept of design had been implemented and verified in both software and hardware. A good agreement was achieved between the finite element model of proposed design and the approximation model (pure sinusoidal function, with a maximum difference of ±1.2%. In addition, the design parameters of the sensor were analysed and investigated. It was found that the error in symmetry of the sinusoidal function could be minimized by adjusting the pitch of helix. The experiments of air-water and oil-water stratified flows were carried out and validated the sinusoidal relationship with a maximum difference of ±1.2% and ±1.3% for the range of water holdup from 0.15 to 0.85. The proposed design concept therefore may pose a promising alternative for the optimization of capacitance sensor design.

  17. Design of Helical Capacitance Sensor for Holdup Measurement in Two-Phase Stratified Flow: A Sinusoidal Function Approach

    Science.gov (United States)

    Lim, Lam Ghai; Pao, William K. S.; Hamid, Nor Hisham; Tang, Tong Boon

    2016-01-01

    A 360° twisted helical capacitance sensor was developed for holdup measurement in horizontal two-phase stratified flow. Instead of suppressing nonlinear response, the sensor was optimized in such a way that a ‘sine-like’ function was displayed on top of the linear function. This concept of design had been implemented and verified in both software and hardware. A good agreement was achieved between the finite element model of proposed design and the approximation model (pure sinusoidal function), with a maximum difference of ±1.2%. In addition, the design parameters of the sensor were analysed and investigated. It was found that the error in symmetry of the sinusoidal function could be minimized by adjusting the pitch of helix. The experiments of air-water and oil-water stratified flows were carried out and validated the sinusoidal relationship with a maximum difference of ±1.2% and ±1.3% for the range of water holdup from 0.15 to 0.85. The proposed design concept therefore may pose a promising alternative for the optimization of capacitance sensor design. PMID:27384567

  18. Sodium hyaluronate-functionalized urea-formaldehyde monolithic column for hydrophilic in-tube solid-phase microextraction of melamine.

    Science.gov (United States)

    Wang, Jiabin; Jiang, Nan; Cai, Zhengmiao; Li, Wenbang; Li, Jianhua; Lin, Xucong; Xie, Zenghong; You, Lijun; Zhang, Qiqing

    2017-09-15

    A novel sodium hyaluronate-functionalized urea-formaldehyde (UF) monolithic column has been developed by in-situ polycondensation of urea, formaldehyde and sodium hyaluronate (HA). HA plays both the roles of crosslinking and hydrophilic functionalization. The preparation factors including different molecular weights of HA and different amounts of HA were optimized, and then a uniform monolith with satisfactory permeability and hydrophilic binding capacity was obtained. Due to the excellent hydrophilicity of HA, HA-functionalized UF monolith showed higher hydrophilic extraction efficiency than UF monolith, and was applied for hydrophilic in-tube solid-phase microextraction (SPME) of melamine (MEL). Several factors for hydrophilic in-tube SPME, such as ACN percentage in the sampling solution, salt concentration and pH value of the sampling solution, elution volume, sampling and elution flow rate, were investigated with respect to the extraction efficiency of MEL. Under the optimized SPME conditions, the limit of detection (LOD) of MEL was found to be 0.2ng/mL in the milk formula samples, the recoveries of MEL spiked in milk formula samples ranged from 87.3% to 96.7% with relative standard deviations (RSDs) less than 5.1%. Owing to the excellent hydrophilic extraction ability, the novel HA-functionalized UF monolith could provide a promising tool for the sensitive analysis of polar analytes in complicated samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Factors that influence obesity, functional capacity, anxiety and depression outcomes following a Phase III cardiac rehabilitation programme.

    Science.gov (United States)

    McKee, Gabrielle; Kerins, Mary; Fitzgerald, Geraldine; Spain, Marie; Morrison, Karen

    2013-10-01

    To examine changes in functional capacity, anxiety, depression and BMI in patients who completed a cardiac rehabilitation programme and to determine the influencing factors. While the effectiveness of cardiac rehabilitation is long established, more studies are needed to examine the combined effectiveness of this multicomponent intervention and the factors that influence this in the changed profile of patients currently attending cardiac rehabilitation. The study was a longitudinal retrospective study of patients following a six- or eight-week Phase III cardiac rehabilitation programme. The study recruited 154 patients. Functional capacity, anxiety, depression, weight, waist circumference and BMI were assessed at the beginning and end of cardiac rehabilitation. t-tests were used to assess changes over time, and multivariate regression analysis was used to determine the influence of factors on these changes. Significant improvements were seen in functional capacity, waist circumference, weight and BMI, but not in depression and anxiety. Multivariate analysis revealed that being younger and less fit was associated with greater improvements in functional capacity while reason for referral, gender, depression or BMI did not influence improvements in functional capacity. Models testing the influence of the factors on BMI, anxiety and depression were not significant. Cardiac rehabilitation is still an effective method to instigate changes in cardiac risk factors despite the changes in patients profile attending programmes. Continued encouragement of the historically less typical patients to participate in cardiac rehabilitation is needed as reason for referral, gender, depression or BMI did not influence improvements in functional capacity. Despite psychosocial components within the programme, no significant improvements were observed over cardiac rehabilitation in depression or anxiety. While effectiveness was observed, there is room for further optimisation of practice

  20. Social anhedonia and work and social functioning in the acute and recovered phases of eating disorders.

    Science.gov (United States)

    Harrison, Amy; Mountford, Victoria A; Tchanturia, Kate

    2014-08-15

    Interpersonal difficulties are proposed to maintain eating disorders (EDs). This study explored whether social anhedonia (SA) was an additional social emotional maintenance factor which might also explain work/social problems in EDs. Additionally, the study explored SA and work and social adjustment in recovered participants. Women with anorexia nervosa (AN; n=105), bulimia nervosa (BN; n=46), recovered from AN (RAN; n=30) and non-ED controls (n=136) completed the Work and Social Adjustment Scale (WSAS) and the Revised Social Anhedonia Scale. ED participants reported greater SA and WSAS scores than non-ED controls; the RAN group reported an intermediate profile. AN participants had poorer work/social adjustment than BN participants. SA was associated with longer illness duration. SA, current severity (BMI) and lifetime severity (lowest adult BMI) significantly predicted work/social difficulties. Recovered participants scoring in the clinical range for SA experienced significantly greater work/social difficulties than recovered participants scoring outside the clinical range for SA. EDs are associated with clinical levels of SA and poor work/social functioning which reduce in recovery. SA may maintain the interpersonal functioning difficulties. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Satellite Material Type and Phase Function Determination in Support of Orbital Debris Size Estimation

    Science.gov (United States)

    Hejduk, M. D.; Cowardin, H. M.; Stansbery, Eugene G.

    2012-01-01

    In performing debris surveys of deep-space orbital regions, the considerable volume of the area to be surveyed and the increased orbital altitude suggest optical telescopes as the most efficient survey instruments; but to proceed this way, methodologies for debris object size estimation using only optical tracking and photometric information are needed. Basic photometry theory indicates that size estimation should be possible if satellite albedo and shape are known. One method for estimating albedo is to try to determine the object's material type photometrically, as one can determine the albedos of common satellite materials in the laboratory. Examination of laboratory filter photometry (using Johnson BVRI filters) on a set of satellite material samples indicates that most material types can be separated at the 1-sigma level via B-R versus R-I color differences with a relatively small amount of required resampling, and objects that remain ambiguous can be resolved by B-R versus B-V color differences and solar radiation pressure differences. To estimate shape, a technique advanced by Hall et al. [1], based on phase-brightness density curves and not requiring any a priori knowledge of attitude, has been modified slightly to try to make it more resistant to the specular characteristics of different materials and to reduce the number of samples necessary to make robust shape determinations. Working from a gallery of idealized debris shapes, the modified technique identifies most shapes within this gallery correctly, also with a relatively small amount of resampling. These results are, of course, based on relatively small laboratory investigations and simulated data, and expanded laboratory experimentation and further investigation with in situ survey measurements will be required in order to assess their actual efficacy under survey conditions; but these techniques show sufficient promise to justify this next level of analysis.

  2. Longitudinal social-interpersonal functioning among higher-risk responders to acute-phase cognitive therapy for recurrent major depressive disorder.

    Science.gov (United States)

    Vittengl, Jeffrey R; Clark, Lee Anna; Thase, Michael E; Jarrett, Robin B

    2016-07-15

    Social-interpersonal dysfunction increases disability in major depressive disorder (MDD). Here we clarified the durability of improvements in social-interpersonal functioning made during acute-phase cognitive therapy (CT), whether continuation CT (C-CT) or fluoxetine (FLX) further improved functioning, and relations of functioning with depressive symptoms and relapse/recurrence. Adult outpatients (N=241) with recurrent MDD who responded to acute-phase CT with higher risk of relapse (due to unstable or partial remission) were randomized to 8 months of C-CT, FLX, or pill placebo plus clinical management (PBO) and followed 24 additional months. We analyzed repeated measures of patients' social adjustment, interpersonal problems, dyadic adjustment, depressive symptoms, and major depressive relapse/recurrence. Large improvements in social-interpersonal functioning occurring during acute-phase CT (median d=1.4) were maintained, with many patients (median=66%) scoring in normal ranges for 32 months. Social-interpersonal functioning did not differ significantly among C-CT, FLX, and PBO arms. Beyond concurrently measured residual symptoms, deterioration in social-interpersonal functioning preceded and predicted upticks in depressive symptoms and major depressive relapse/recurrence. Results may not generalize to other patient populations, treatment protocols, or measures of social-interpersonal functioning. Mechanisms of risk connecting poorer social-interpersonal functioning with depression were not studied. Average improvements in social-interpersonal functioning among higher-risk responders to acute phase CT are durable for 32 months. After acute-phase CT, C-CT or FLX may not further improve social-interpersonal functioning. Among acute-phase CT responders, deteriorating social-interpersonal functioning provides a clear, measurable signal of risk for impending major depressive relapse/recurrence and opportunity for preemptive intervention. Copyright © 2016 Elsevier B

  3. Auto-inhibitory regulation of angiotensin II functionality in hamster aorta during the early phases of dyslipidemia.

    Science.gov (United States)

    Pereira, Priscila Cristina; Pernomian, Larissa; Côco, Hariane; Gomes, Mayara Santos; Franco, João José; Marchi, Kátia Colombo; Hipólito, Ulisses Vilela; Uyemura, Sergio Akira; Tirapelli, Carlos Renato; de Oliveira, Ana Maria

    2016-06-15

    Emerging data point the crosstalk between dyslipidemia and renin-angiotensin system (RAS). Advanced dyslipidemia is described to induce RAS activation in the vasculature. However, the interplay between early dyslipidemia and the RAS remains unexplored. Knowing that hamsters and humans have a similar lipid profile, we investigated the effects of early and advanced dyslipidemia on angiotensin II-induced contraction. Cumulative concentration-response curves for angiotensin II (1.0pmol/l to 1.0µmol/l) were obtained in the hamster thoracic aorta. We also investigated the modulatory action of NAD(P)H oxidase on angiotensin II-induced contraction using ML171 (Nox-1 inhibitor, 0.5µmol/l) and VAS2870 (Nox-4 inhibitor, 5µmol/l). Early dyslipidemia was detected in hamsters treated with a cholesterol-rich diet for 15 days. Early dyslipidemia decreased the contraction induced by angiotensin II and the concentration of Nox-4-derived hydrogen peroxide. Advanced dyslipidemia, observed in hamsters treated with cholesterol-rich diet for 30 days, restored the contractile response induced by angiotensin II by compensatory mechanism that involves Nox-4-mediated oxidative stress. The hyporresponsiveness to angiotensin II may be an auto-inhibitory regulation of the angiotensinergic function during early dyslipidemia in an attempt to reduce the effects of the upregulation of the vascular RAS during the advanced stages of atherogenesis. The recovery of vascular angiotensin II functionality during the advanced phases of dyslipidemia is the result of the upregulation of redox-pro-inflammatory pathway that might be most likely involved in atherogenesis progression rather than in the recovery of vascular function. Taken together, our findings show the early phase of dyslipidemia may be the most favorable moment for effective atheroprotective therapeutic interventions. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Atomic Pairwise Distribution Function Analysis of the Amorphous Phase Prepared by Different Manufacturing Routes

    Directory of Open Access Journals (Sweden)

    Thomas Rades

    2012-01-01

    Full Text Available Amlodipine besilate, a calcium channel antagonist, exists in several solid forms. Processing of anhydrate and dihydrate forms of this drug may lead to solid state changes, and is therefore the focus of this study. Milling was performed for the anhydrate form, whereas the dihydrate form was subjected to quench cooling thereby creating an amorphous form of the drug from both starting materials. The milled and quench cooled samples were, together with the crystalline starting materials, analyzed with X-ray powder diffraction (XRPD, Raman spectroscopy and atomic pair-wise distribution function (PDF analysis of the XRPD pattern. When compared to XRPD and Raman spectroscopy, the PDF analysis was superior in displaying the difference between the amorphous samples prepared by milling and quench cooling approaches of the two starting materials.

  5. The influence of recovery and training phases on body composition, peripheral vascular function and immune system of professional soccer players.

    Directory of Open Access Journals (Sweden)

    Simon Reinke

    Full Text Available Professional soccer players have a lengthy playing season, throughout which high levels of physical stress are maintained. The following recuperation period, before starting the next pre-season training phase, is generally considered short but sufficient to allow a decrease in these stress levels and therefore a reduction in the propensity for injury or musculoskeletal tissue damage. We hypothesised that these physical extremes influence the body composition, blood flow, and endothelial/immune function, but that the recuperation may be insufficient to allow a reduction of tissue stress damage. Ten professional football players were examined at the end of the playing season, at the end of the season intermission, and after the next pre-season endurance training. Peripheral blood flow and body composition were assessed using venous occlusion plethysmography and DEXA scanning respectively. In addition, selected inflammatory and immune parameters were analysed from blood samples. Following the recuperation period a significant decrease of lean body mass from 74.4+/-4.2 kg to 72.2+/-3.9 kg was observed, but an increase of fat mass from 10.3+/-5.6 kg to 11.1+/-5.4 kg, almost completely reversed the changes seen in the pre-season training phase. Remarkably, both resting and post-ischemic blood flow (7.3+/-3.4 and 26.0+/-6.3 ml/100 ml/min respectively, were strongly reduced during the playing and training stress phases, but both parameters increased to normal levels (9.0+/-2.7 and 33.9+/-7.6 ml/100 ml/min during the season intermission. Recovery was also characterized by rising levels of serum creatinine, granulocytes count, total IL-8, serum nitrate, ferritin, and bilirubin. These data suggest a compensated hypo-perfusion of muscle during the playing season, followed by an intramuscular ischemia/reperfusion syndrome during the recovery phase that is associated with muscle protein turnover and inflammatory endothelial reaction, as demonstrated by i

  6. Towards automated human gait disease classification using phase space representation of intrinsic mode functions

    Science.gov (United States)

    Pratiher, Sawon; Patra, Sayantani; Pratiher, Souvik

    2017-06-01

    A novel analytical methodology for segregating healthy and neurological disorders from gait patterns is proposed by employing a set of oscillating components called intrinsic mode functions (IMF's). These IMF's are generated by the Empirical Mode Decomposition of the gait time series and the Hilbert transformed analytic signal representation forms the complex plane trace of the elliptical shaped analytic IMFs. The area measure and the relative change in the centroid position of the polygon formed by the Convex Hull of these analytic IMF's are taken as the discriminative features. Classification accuracy of 79.31% with Ensemble learning based Adaboost classifier validates the adequacy of the proposed methodology for a computer aided diagnostic (CAD) system for gait pattern identification. Also, the efficacy of several potential biomarkers like Bandwidth of Amplitude Modulation and Frequency Modulation IMF's and it's Mean Frequency from the Fourier-Bessel expansion from each of these analytic IMF's has been discussed for its potency in diagnosis of gait pattern identification and classification.

  7. Multi-Function Waste Tank Facility Corrosion Test Report (Phase 1)

    International Nuclear Information System (INIS)

    Carlos, W. C.; Fritz, R. L.

    1993-01-01

    This report documents the results of the corrosion tests that were performed to aid in the selection of the construction materials for multi-function waste tanks to be built in the U.S. Department of Energy Hanford Site. Two alloys were tested: 304L and Alloy 20 austenitic stainless steel. The test media were aqueous solutions formulated to represent the extreme of the chemical compositions of waste to be stored in the tanks. The results summerized by alloy are as follows: For 304L the tests showed no stress-corrosion cracking in any of the nine test solutions. The tests showed pitting in on of the solutions. There were no indications of any weld heat-tint corrosion, nor any sign of preferential corrosion in the welded areas. For Alloy 20 the tests showed no general, pitting, or stress-corrosion cracking. One crevice corrosion coupon cracked at the web between a hole and the edge of the coupon in one of the solutions. Mechanical tests showed some possible crack extension in the same solution. Because of the failure of both alloys to meet test acceptance criteria, the tank waste chemistry will have to be restricted or an alternative alloy tested

  8. Phenotypic, Functional, and Safety Control at Preimplantation Phase of MSC-Based Therapy.

    Science.gov (United States)

    Lech, Wioletta; Figiel-Dabrowska, Anna; Sarnowska, Anna; Drela, Katarzyna; Obtulowicz, Patrycja; Noszczyk, Bartlomiej Henryk; Buzanska, Leonora; Domanska-Janik, Krystyna

    2016-01-01

    Mesenchymal stem cells (MSC) exhibit enormous heterogeneity which can modify their regenerative properties and therefore influence therapeutic effectiveness as well as safety of these cells transplantation. In addition the high phenotypic plasticity of MSC population makes it enormously sensitive to any changes in environmental properties including fluctuation in oxygen concentration. We have shown here that lowering oxygen level far below air atmosphere has a beneficial impact on various parameters characteristic for umbilical cord Wharton Jelly- (WJ-) MSC and adipose tissue- (AD-) derived MSC cultures. This includes their cellular composition, rate of proliferation, and maintenance of stemness properties together with commitment to cell differentiation toward mesodermal and neural lineages. In addition, the culture genomic stability increased significantly during long-term cell passaging and eventually protected cells against spontaneous transformation. Also by comparing of two routinely used methods of MSCs isolation (mechanical versus enzymatic) we have found substantial divergence arising between cell culture properties increasing along the time of cultivation in vitro. Thus, in this paper we highlight the urgent necessity to develop the more sensitive and selective methods for prediction and control cells fate and functioning during the time of growth in vitro.

  9. Phenotypic, Functional, and Safety Control at Preimplantation Phase of MSC-Based Therapy

    Science.gov (United States)

    Lech, Wioletta; Figiel-Dabrowska, Anna; Drela, Katarzyna; Obtulowicz, Patrycja; Noszczyk, Bartlomiej Henryk; Buzanska, Leonora

    2016-01-01

    Mesenchymal stem cells (MSC) exhibit enormous heterogeneity which can modify their regenerative properties and therefore influence therapeutic effectiveness as well as safety of these cells transplantation. In addition the high phenotypic plasticity of MSC population makes it enormously sensitive to any changes in environmental properties including fluctuation in oxygen concentration. We have shown here that lowering oxygen level far below air atmosphere has a beneficial impact on various parameters characteristic for umbilical cord Wharton Jelly- (WJ-) MSC and adipose tissue- (AD-) derived MSC cultures. This includes their cellular composition, rate of proliferation, and maintenance of stemness properties together with commitment to cell differentiation toward mesodermal and neural lineages. In addition, the culture genomic stability increased significantly during long-term cell passaging and eventually protected cells against spontaneous transformation. Also by comparing of two routinely used methods of MSCs isolation (mechanical versus enzymatic) we have found substantial divergence arising between cell culture properties increasing along the time of cultivation in vitro. Thus, in this paper we highlight the urgent necessity to develop the more sensitive and selective methods for prediction and control cells fate and functioning during the time of growth in vitro. PMID:27651796

  10. Viral cyclins mediate separate phases of infection by integrating functions of distinct mammalian cyclins.

    Directory of Open Access Journals (Sweden)

    Katherine S Lee

    2012-02-01

    Full Text Available Gammaherpesvirus cyclins have expanded biochemical features relative to mammalian cyclins, and promote infection and pathogenesis including acute lung infection, viral persistence, and reactivation from latency. To define the essential features of the viral cyclin, we generated a panel of knock-in viruses expressing various viral or mammalian cyclins from the murine gammaherpesvirus 68 cyclin locus. Viral cyclins of both gammaherpesvirus 68 and Kaposi's sarcoma-associated herpesvirus supported all cyclin-dependent stages of infection, indicating functional conservation. Although mammalian cyclins could not restore lung replication, they did promote viral persistence and reactivation. Strikingly, distinct and non-overlapping mammalian cyclins complemented persistence (cyclin A, E or reactivation from latency (cyclin D3. Based on these data, unique biochemical features of viral cyclins (e.g. enhanced kinase activation are not essential to mediate specific processes during infection. What is essential for, and unique to, the viral cyclins is the integration of the activities of several different mammalian cyclins, which allows viral cyclins to mediate multiple, discrete stages of infection. These studies also demonstrated that closely related stages of infection, that are cyclin-dependent, are in fact genetically distinct, and thus predict that cyclin requirements may be used to tailor potential therapies for virus-associated diseases.

  11. Atomic pairwise distribution function analysis of the amorphous phase prepared by different manufacturing routes

    DEFF Research Database (Denmark)

    Boetker, Johan P.; Koradia, Vishal; Rades, Thomas

    2012-01-01

    Amlodipine besilate, a calcium channel antagonist, exists in several solid forms. Processing of anhydrate and dihydrate forms of this drug may lead to solid state changes, and is therefore the focus of this study. Milling was performed for the anhydrate form, whereas the dihydrate form was subjec......Amlodipine besilate, a calcium channel antagonist, exists in several solid forms. Processing of anhydrate and dihydrate forms of this drug may lead to solid state changes, and is therefore the focus of this study. Milling was performed for the anhydrate form, whereas the dihydrate form...... was subjected to quench cooling thereby creating an amorphous form of the drug from both starting materials. The milled and quench cooled samples were, together with the crystalline starting materials, analyzed with X-ray powder diffraction (XRPD), Raman spectroscopy and atomic pair-wise distribution function...... (PDF) analysis of the XRPD pattern. When compared to XRPD and Raman spectroscopy, the PDF analysis was superior in displaying the difference between the amorphous samples prepared by milling and quench cooling approaches of the two starting materials....

  12. Phase II clinical study on sup 99m Tc-GSA, a new agent for functional imaging of the liver

    Energy Technology Data Exchange (ETDEWEB)

    Torizuka, Kanji (Fukui Medical School (Japan)); Ha-Kawa, S.K.; Kudo, Masatoshi; Kitagawa, Shinichi; Kubota, Yoshitsugu; Tanaka, Yoshimasa; Hino, Megumu; Ikekubo, Katsuji

    1992-01-01

    Phase II study of {sup 99m}Tc-DTPA-galactosyl human serum albumin ({sup 99m}Tc-GSA), a new radiopharmaceutical which binds to the asialoglycoprotein receptors on the hepatocytes, was performed in 81 patients with liver diseases to validate its safety and possibility for the evaluation of hepatic function. None of adverse reactions, abnormal clinical laboratory findings and anti-{sup 99m}Tc-GSA antibody production due to {sup 99m}Tc-GSA was recognized. Immediately after the injection of {sup 99m}Tc-GSA, the dynamic data and serial hepatic images were obtained for 60 min. The indices for blood clearance and liver accumulation were calculated based on the counts in the regions of interest on the hearts and livers. In 54 patients with chronic hepatic disorders such as liver cirrhosis, the blood clearance and liver accumulation of {sup 99m}Tc-GSA were retarded according to the progress of the hepatic disorders. The findings of {sup 99m}Tc-GSA scintigraphy also reflected the hepatic functions of the patients with large hepatic tumors, obstructive jaundice and acute hepatitis. These results suggest that {sup 99m}Tc-GSA has the clinical potentials to evaluate the liver functions in the patients with hepatic disorders. (author).

  13. Evaluation of higher brain function by MRI. Flow measurement in the superior sagittal sinus using phase contrast method

    International Nuclear Information System (INIS)

    Ono, Mototsugu

    1997-01-01

    To assess the higher brain function, flow measurement in the superior sagittal sinus (SSS) was performed noninvasively using a phase contrast MRI in 76 patients with suspicious of impaired higher brain function including dementias (senile dementia of Alzheimer type; SDAT and multi-infarct dementia; MID), strokes, and others. Thirty-one normal controls were consisted of 18 healthy volunteers and 13 patients with tension headache whose higher brain function was proved be normal. Mean flow velocity was measured in the distal portion of the SSS adjoining to the occipital lobes and was multiplied by cross-sectional area of the SSS at the measuring point to obtain mean flow volume. For intellectual index, cross-cultural cognitive examination (CCCE) was applied to all cases excluding volunteers. Normal value of SSS flow volume measured by MRI was 6.92±0.66 ml/s. Significant differences in both SSS flow and CCCE score from normal controls were found in SDAT group, MID group, and non-dementia group. No substantial differences between SDAT group and MID group were noted in both CCCE score and SSS flow. In normal controls, there was no correlation between SSS flow and age, whereas, significant inverse correlation of SSS flow with age was found in all cases. Between CCCE score and SSS flow, there were nearly linear relationships in all cases, SDAT group, MID group, and non-dementia group. Significant but relatively poor correlation was found in normals. (K.H.)

  14. Functional analysis of third ventriculostomy patency by quantification of CSF stroke volume by using cine phase-contrast MR imaging.

    Science.gov (United States)

    Bargalló, Núria; Olondo, Lourdes; Garcia, Ana I; Capurro, Sebastian; Caral, Luis; Rumia, Jordi

    2005-01-01

    Endoscopic third ventriculostomy (ETV) is increasingly used as alternative treatment for obstructive hydrocephalus. The aim of this study was to determine the utility of quantitative and qualitative examinations with cine phase-contrast MR imaging to determine the efficacy of ventriculostomy across time and whether CSF pulsation is restored after ETV. Thirty-eight patients treated with ETV were evaluated with cine phase-contrast MR within 1 month after surgery. Follow-up studies were performed after 1 year in 25 patients and after 2 years in 12. We evaluated flow void changes in the floor of the third ventricle and quantified the stroke volume at the site of the ventriculostomy. We also recorded changes in ventricular size and clinical outcome. To determine the restoration of CSF pulsation, we compared the CSF waveform at the ventriculostomy with the CSF waveform at the aqueduct in a healthy control group. After ventriculostomy, restoration of pulsate motion characteristics of CSF circulation was observed. The stroke volume registered at ventriculostomy was maintained with time. There was a statistically significant relationship between clinical outcome and stroke volume. Overall flow magnitude was the most effective variable to determine which patients would improve after surgery. Values >75 mm3 showed a sensitivity of 76.7% and a specificity of 87.5% There was no relationship between ventricular size changes and clinical outcome. Patients with primary aqueduct stenosis had the best response to surgery, whereas patients with Arnold Chiari malformation or communicating hydrocephalus had the worst response. Quantitative analysis with phase-contrast MR imaging indicates that ETV is an efficient technique for restoring CSF pulsation, with efficacy being maintained during the follow-up controls. Quantification of stroke volume at ventriculostomy is a good indicator of the functional status of ETV, and a high stroke volume in the ventriculostomy appears to be a positive

  15. Phase behaviour of symmetric binary mixtures with partially miscible components in slit-like pores. Application of the fundamental measure density functional approach

    CERN Document Server

    Martínez, A; Patrykiejew, A; Sokolowski, S

    2003-01-01

    We investigate adsorption in slit-like pores of model symmetric binary mixtures exhibiting demixing in bulk phase, by using a density functional approach. Our focus is on the evaluation of the first-order phase transitions in adsorbed fluids and the lines separating mixed and demixed phases. The scenario for phase transitions is sensitive to the pore width and to the energy of adsorption. Both these parameters can change the phase diagrams of the confined fluid. In particular, for relatively wide pores and for strong wall-fluid interactions, the demixing line can precede the first-order transition. Moreover, a competition between layering transitions and demixing within particular layers also leads to further enrichment of the phase diagram.

  16. Evaluating the normal individual cardiac function in different imaging phases post exercise and rest by gated SPECT myocardial perfusion

    International Nuclear Information System (INIS)

    Hua, W.; Li, S.J.; Liu, J.Z.; Li, X.F.; Jin, C.R.; Hu, G.; Wang, J.

    2007-01-01

    Full text: Objectives: To evaluate the normal individual cardiac function in the different imaging phases post-exercise and rest by GSPECT. Methods: 46 normal individuals underwent exercise/rest GSPECT using 99mTc-MIBI by 2- day program. Sequential imaging was started 15, 35 and 120 minutes after exercise and rest imaging was performed the following day. The left ventricular EF and EDV, ESV values were calculated with the Cedars-Sinai program. Results: The EF values of post- exercise at 15, 35, and 120m was 64.48±7.43%, 65.02±7.66%, and 60.98±7.28% respectively, and the rest EF value was 61.46±7.23%. The post exercise EF at 15m and 35m was higher than EF at post- exercise 120m and rest, but there is a significant difference only between post exercise 35m and rest (P< 0.05), and all post exercise EF did not increase at least 5% from EF at-rest. The EDV and ESV values did not have statistically significant differences at 15, 35,120m post-exercise and rest. The heart rate at 15,35m post- exercise was higher significantly than at rest. Conclusions: The different imaging phases after exercise with 99mTc-MIBI GSPECT affects LVEF in normal individuals, the 35m post- exercise EF is highest. (author)

  17. Two-Phase Iteration for Value Function Approximation and Hyperparameter Optimization in Gaussian-Kernel-Based Adaptive Critic Design

    Directory of Open Access Journals (Sweden)

    Xin Chen

    2015-01-01

    Full Text Available Adaptive Dynamic Programming (ADP with critic-actor architecture is an effective way to perform online learning control. To avoid the subjectivity in the design of a neural network that serves as a critic network, kernel-based adaptive critic design (ACD was developed recently. There are two essential issues for a static kernel-based model: how to determine proper hyperparameters in advance and how to select right samples to describe the value function. They all rely on the assessment of sample values. Based on the theoretical analysis, this paper presents a two-phase simultaneous learning method for a Gaussian-kernel-based critic network. It is able to estimate the values of samples without infinitively revisiting them. And the hyperparameters of the kernel model are optimized simultaneously. Based on the estimated sample values, the sample set can be refined by adding alternatives or deleting redundances. Combining this critic design with actor network, we present a Gaussian-kernel-based Adaptive Dynamic Programming (GK-ADP approach. Simulations are used to verify its feasibility, particularly the necessity of two-phase learning, the convergence characteristics, and the improvement of the system performance by using a varying sample set.

  18. SHARED, NOT UNIQUE, COMPONENTS OF PERSONALITY AND PSYCHOSOCIAL FUNCTIONING PREDICT DEPRESSION SEVERITY AFTER ACUTE-PHASE COGNITIVE THERAPY

    Science.gov (United States)

    Clark, Lee Anna; Vittengl, Jeffrey R.; Kraft, Dolores; Jarrett, Robin B.

    2005-01-01

    In a sample of 100 patients with recurrent major depression, we collected depression severity data early and late in acute-phase cognitive therapy, plus a wide range of psychosocial variables that have been studied extensively in depression research, including measures of interpersonal, cognitive, and social functioning, and personality traits using an inventory that is linked with the Big-Three tradition in personality assessment theory. By assessing this broad range of variables in a single study, we could examine the extent to which relations of these variables with depression were due to (a) a common factor shared across this diverse set of constructs, (b) factors shared among each type of construct (personality vs. psychosocial measures), or (c) specific aspects of the individual measures. Only the most general factor shared across the personality and psychosocial variables predicted later depression. PMID:14632375

  19. Extensively Reversible Thermal Transformations of a Bistable, Fluorescence-Switchable Molecular Solid: Entry into Functional Molecular Phase-Change Materials.

    Science.gov (United States)

    Srujana, P; Radhakrishnan, T P

    2015-06-15

    Functional phase-change materials (PCMs) are conspicuously absent among molecular materials in which the various attributes of inorganic solids have been realized. While organic PCMs are primarily limited to thermal storage systems, the amorphous-crystalline transformation of materials like Ge-Sb-Te find use in advanced applications such as information storage. Reversible amorphous-crystalline transformations in molecular solids require a subtle balance between robust supramolecular assembly and flexible structural elements. We report novel diaminodicyanoquinodimethanes that achieve this transformation by interlinked helical assemblies coupled with conformationally flexible alkoxyalkyl chains. They exhibit highly reversible thermal transformations between bistable (crystalline/amorphous) forms, along with a prominent switching of the fluorescence emission energy and intensity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Decoupling control of a five-phase fault-tolerant permanent magnet motor by radial basis function neural network inverse

    Science.gov (United States)

    Chen, Qian; Liu, Guohai; Xu, Dezhi; Xu, Liang; Xu, Gaohong; Aamir, Nazir

    2018-05-01

    This paper proposes a new decoupled control for a five-phase in-wheel fault-tolerant permanent magnet (IW-FTPM) motor drive, in which radial basis function neural network inverse (RBF-NNI) and internal model control (IMC) are combined. The RBF-NNI system is introduced into original system to construct a pseudo-linear system, and IMC is used as a robust controller. Hence, the newly proposed control system incorporates the merits of the IMC and RBF-NNI methods. In order to verify the proposed strategy, an IW-FTPM motor drive is designed based on dSPACE real-time control platform. Then, the experimental results are offered to verify that the d-axis current and the rotor speed are successfully decoupled. Besides, the proposed motor drive exhibits strong robustness even under load torque disturbance.

  1. Bose-Einstein condensation and long-range phase coherence in the many-particle Schroedinger wave function

    International Nuclear Information System (INIS)

    Mayers, J.

    2001-01-01

    The properties of the many-particle Schroedinger wave function Ψ are examined in the presence of Bose-Einstein condensation (BEC). It is shown that it is possible to define, in terms of Ψ, a function ψ(r-vector vertical bar s-vector), which can be regarded as the single-particle wave function of an arbitrary particle for a fixed configuration s-vector of all other particles. It is shown that ψ(r-vector|s-vector) plays an analogous role to the field operator of standard field-theoretical treatments of superfluidity. It is shown that in the presence of a Bose-Einstein condensate fraction f, ψ(r-vector|s-vector) must be nonzero and phase coherent within at least a fraction f of the total volume of the N-particle system for essentially all s-vector. Examination of the form of variational many-particle wave functions shows that in liquid 4 He, ψ(r-vector|s-vector) extends throughout the spaces left between the hard cores of the other atoms at s-vector. By contrast, in the absence of BEC, ψ(r-vector|s-vector) in the ground state must be nonzero only over a localized region of space. It is shown that in order for long-range phase coherence in ψ(r-vector|s-vector) to be maintained in the presence of velocity fields, any circulation must be quantized over macroscopic length scales. Some numerical calculations of the properties and fluctuations of liquid helium are presented. These suggest that the approach outlined in this paper may have significant advantages for the numerical calculations of the properties of Bose-Einstein condensed systems. The properties of ψ(r-vector|s-vector) are used to show that there is no general connection between the static structure factor and the size of the Bose-Einstein condensate fraction in a Bose fluid. It is suggested that the observed connection in liquid 4 He is due to the creation of vacancies in the liquid structure, which are required so that ψ(r-vector vertical bar s-vector) can delocalize, in the presence of hard

  2. Fog droplet distribution functions for lidar.

    Science.gov (United States)

    Mallow, J V

    1982-04-15

    The interpretation of lidar data on fog has been limited by two obstacles: approximations in the form of the Mie scattering cross sections for water droplets, and droplet size distribution functions whose relationship to the experiment has not been clear. This paper develops a method for generating distribution functions from experimental data. These functions are then used with newly available Mie cross sections to obtain backscattering and extinction coefficients for singly scattered ruby laser pulses in fog. The results show what experimental lidar accuracies are needed to uniquely determine fog droplet size distribution.

  3. Ab initio density functional theory investigation of the structural, electronic and optical properties of Ca3Sb2 in hexagonal and cubic phases

    International Nuclear Information System (INIS)

    Arghavani Nia, Borhan; Sedighi, Matin; Shahrokhi, Masoud; Moradian, Rostam

    2013-01-01

    A density functional theory study of structural, electronical and optical properties of Ca 3 Sb 2 compound in hexagonal and cubic phases is presented. In the exchange–correlation potential, generalized gradient approximation (PBE-GGA) has been used to calculate lattice parameters, bulk modulus, cohesive energy, dielectric function and energy loss spectra. The electronic band structure of this compound has been calculated using the above two approximations as well as another form of PBE-GGA, proposed by Engle and Vosko (EV-GGA). It is found that the hexagonal phase of Ca 3 Sb 2 has an indirect gap in the Γ→N direction; while in the cubic phase there is a direct-gap at the Γ point in the PBE-GGA and EV-GGA. Effects of applying pressure on the band structure of the system studied and optical properties of these systems were calculated. - Graphical abstract: A density functional theory study of structural, electronic and optical properties of Ca 3 Sb 2 compound in hexagonal and cubic phases is presented. Display Omitted - Highlights: • Physical properties of Ca 3 Sb 2 in hexagonal and cubic phases are investigated. • It is found that the hexagonal phase is an indirect gap semiconductor. • Ca 3 Sb 2 is a direct-gap semiconductor at the Γ point in the cubic phase. • By increasing pressure the semiconducting band gap and anti-symmetry gap are decreased

  4. Hemimicelle capped functionalized carbon nanotubes-based nanosized solid-phase extraction of arsenic from environmental water samples

    International Nuclear Information System (INIS)

    Li Lu; Huang Yuming; Wang Yan; Wang Weidong

    2009-01-01

    The end functionalization of CNTs can introduce oxygen-containing negatively functional groups such as -COOH, -OH, or -C=O on their surface site. If cationic surfactant such as cetyltrimethylammonium chloride (CTAC) was added to the functionalized CNTs, then interactions such as hydrophobic and ionic may lead to formation of hemimicelle/admicelle aggregates on the CNTs, a new kind of adsorbents, namely, the hemimicelle capped CMMWCNTs, is obtained. The application of the hemimicelle capped carbon nanotubes-based nanosized solid-phase extraction (SPE) adsorbents in environmental analysis is reported for the first time using arsenic as model target. The effect of adsorption and desorption conditions for arsenic including the amount of surfactant, initial pH of sample solution, the ultrasonic time of sample solution, the amount of electrolyte, flow rate, eluent and its amount were investigated and optimized prior to its determination by atomic fluorescence spectrophotometry (AFS). Arsenic can be quantitatively retained on the hemimicelle capped CMMWCNTs at pH 5-6 from sample volume up to 500 mL and then eluted completely with 2 mol L -1 HNO 3 in the presence of 10 mg L -1 CTAC. The method detection limit for arsenic determination with AFS detection was 2 ng L -1 , and the relative standard deviation (RSD, n = 11) was 5.3% at the 0.5 μg L -1 level. The recoveries of arsenic in the spiked environmental water samples ranged from 94% to 104.29% with 500 mL of water sample. The proposed method has been applied successfully to the analysis of arsenic in aqueous environmental samples, which demonstrates the hemimicelle capped CMMWCNTs can be an excellent SPE adsorbents for arsenic pretreatment and enrichment from real water samples

  5. Molecular transformations of phenolic SOA during photochemical aging in the aqueous phase: competition among oligomerization, functionalization, and fragmentation

    Directory of Open Access Journals (Sweden)

    L. Yu

    2016-04-01

    Full Text Available Organic aerosol is formed and transformed in atmospheric aqueous phases (e.g., cloud and fog droplets and deliquesced airborne particles containing small amounts of water through a multitude of chemical reactions. Understanding these reactions is important for a predictive understanding of atmospheric aging of aerosols and their impacts on climate, air quality, and human health. In this study, we investigate the chemical evolution of aqueous secondary organic aerosol (aqSOA formed during reactions of phenolic compounds with two oxidants – the triplet excited state of an aromatic carbonyl (3C∗ and hydroxyl radical (•OH. Changes in the molecular composition of aqSOA as a function of aging time are characterized using an offline nanospray desorption electrospray ionization mass spectrometer (nano-DESI MS whereas the real-time evolution of SOA mass, elemental ratios, and average carbon oxidation state (OSC are monitored using an online aerosol mass spectrometer (AMS. Our results indicate that oligomerization is an important aqueous reaction pathway for phenols, especially during the initial stage of photooxidation equivalent to  ∼  2 h irradiation under midday winter solstice sunlight in Northern California. At later reaction times functionalization (i.e., adding polar oxygenated functional groups to the molecule and fragmentation (i.e., breaking of covalent bonds become more important processes, forming a large variety of functionalized aromatic and open-ring products with higher OSC values. Fragmentation reactions eventually dominate the photochemical evolution of phenolic aqSOA, forming a large number of highly oxygenated ring-opening molecules with carbon numbers (nC below 6. The average nC of phenolic aqSOA decreases while average OSC increases over the course of photochemical aging. In addition, the saturation vapor pressures (C∗ of dozens of the most abundant phenolic aqSOA molecules are estimated. A wide range of C

  6. Advanced functional materials in solid phase extraction for ICP-MS determination of trace elements and their species - A review.

    Science.gov (United States)

    He, Man; Huang, Lijin; Zhao, Bingshan; Chen, Beibei; Hu, Bin

    2017-06-22

    For the determination of trace elements and their species in various real samples by inductively coupled plasma mass spectrometry (ICP-MS), solid phase extraction (SPE) is a commonly used sample pretreatment technique to remove complex matrix, pre-concentrate target analytes and make the samples suitable for subsequent sample introduction and measurements. The sensitivity, selectivity/anti-interference ability, sample throughput and application potential of the methodology of SPE-ICP-MS are greatly dependent on SPE adsorbents. This article presents a general overview of the use of advanced functional materials (AFMs) in SPE for ICP-MS determination of trace elements and their species in the past decade. Herein the AFMs refer to the materials featuring with high adsorption capacity, good selectivity, fast adsorption/desorption dynamics and satisfying special requirements in real sample analysis, including nanometer-sized materials, porous materials, ion imprinting polymers, restricted access materials and magnetic materials. Carbon/silica/metal/metal oxide nanometer-sized adsorbents with high surface area and plenty of adsorption sites exhibit high adsorption capacity, and porous adsorbents would provide more adsorption sites and faster adsorption dynamics. The selectivity of the materials for target elements/species can be improved by using physical/chemical modification, ion imprinting and restricted accessed technique. Magnetic adsorbents in conventional batch operation offer unique magnetic response and high surface area-volume ratio which provide a very easy phase separation, greater extraction capacity and efficiency over conventional adsorbents, and chip-based magnetic SPE provides a versatile platform for special requirement (e.g. cell analysis). The performance of these adsorbents for the determination of trace elements and their species in different matrices by ICP-MS is discussed in detail, along with perspectives and possible challenges in the future

  7. Left ventricular diastolic dysfunction in pulmonary hypertension predicts functional capacity and clinical worsening: a tissue phase mapping study.

    Science.gov (United States)

    Knight, Daniel S; Steeden, Jennifer A; Moledina, Shahin; Jones, Alexander; Coghlan, J Gerry; Muthurangu, Vivek

    2015-12-29

    The function of the right and left ventricles is intimately related through a shared septum and pericardium. Therefore, right ventricular (RV) disease in pulmonary hypertension (PH) can result in abnormal left ventricular (LV) myocardial mechanics. To assess this, we implemented novel cardiovascular magnetic resonance (CMR) tissue phase mapping (TPM) to assess radial, longitudinal and tangential LV myocardial velocities in patients with PH. Respiratory self-gated TPM was performed using a rotating golden-angle spiral acquisition with retrospective cardiac gating. TPM of a mid ventricular slice was acquired in 40 PH patients and 20 age- and sex-matched healthy controls. Endocardial and epicardial LV borders were manually defined, and myocardial velocities calculated using in-house software. Patients without proximal CTEPH (chronic thromboembolic PH) and not receiving intravenous prostacyclin therapy (n = 34) were followed up until the primary outcome of disease progression (death, transplantation, or progression to intravenous therapy) or the end of the study. Physicians who determined disease progression were blinded to CMR data. Conventional ventricular volumetric indices and novel TPM metrics were analyzed for prediction of 6-min walk distance (6MWD) and disease progression. Peak longitudinal (p < 0.0001) and radial (p = 0.001) early diastolic (E) wave velocities were significantly lower in PH patients compared with healthy volunteers. Reversal of tangential E waves was observed in all patients and was highly discriminative for the presence of PH (p < 0.0001). The global radial E wave (β = 0.41, p = 0.017) and lateral wall radial systolic (S) wave velocities (β = 0.33, p = 0.028) were the only independent predictors of 6MWD in a model including RV ejection fraction (RVEF) and LV stroke volume. Over a median follow-up period of 20 months (IQR 7.9 months), 8 patients commenced intravenous therapy and 1 died. Global longitudinal E

  8. The value of radionuclide phase analysis and parameters of cardial function for diagnosis CAD at rest and during exercise

    International Nuclear Information System (INIS)

    Huang Gang

    1990-01-01

    27 patients and 5 normal were studied with ECG-gated cardial blood pool images and radionuclide phase analysis at rest and during exercise. The results showed that the sensitivity of LVEF in CAD at rest and during exercise were 57% and 71% respectively, and the sensitivity of the ventricular phase in CAD were 79% at rest and 90% during exercise, and the sensitivity of phase angle in CAD were higher than of LVEF. This suggested that the ventricular phase angle was important for diagnosing early CAD. In addition, regional EF, phase image and ventricular wall motion were useful to detect the lesion of ischemia in CAD

  9. Effects of London dispersion correction in density functional theory on the structures of organic molecules in the gas phase.

    Science.gov (United States)

    Grimme, Stefan; Steinmetz, Marc

    2013-10-14

    A benchmark set of 25 rotational constants measured in the gas phase for nine molecules (termed ROT25) was compiled from available experimental data. The medium-sized molecules with 18-35 atoms cover common (bio)organic structure motifs including hydrogen bonding and flexible side chains. They were each considered in a single conformation. The experimental B0 values were back-corrected to reference equilibrium rotational constants (Be) by computation of the vibrational corrections ΔBvib. Various density functional theory (DFT) methods and Hartree-Fock with and without dispersion corrections as well as MP2 type methods and semi-empirical quantum chemical approaches are investigated. The ROT25 benchmark tests their ability to describe covalent bond lengths, longer inter-atomic distances, and the relative orientation of functional groups (intramolecular non-covalent interactions). In general, dispersion corrections to DFT and HF increase Be values (shrink molecular size) significantly by about 0.5-1.5% thereby in general improving agreement with the reference data. Regarding DFT methods, the overall accuracy of the optimized structures roughly follows the 'Jacobs ladder' classification scheme, i.e., it decreases in the series double-hybrid > (meta)hybrid > (meta)GGA > LDA. With B2PLYP-D3, SCS-MP2, B3LYP-D3/NL, or PW6B95-D3 methods and extended QZVP (def2-TZVP) AO basis sets, Be values, accurate to about 0.3-0.6 (0.5-1)% on average, can be computed routinely. The accuracy of B2PLYP-D3/QZVP with a mean deviation of only 3 MHz and a standard deviation of 0.24% is exceptional and we recommend this method when highly accurate structures are required or for problematic conformer assignments. The correlation effects for three inter-atomic distance regimes (covalent, medium-range, long) and the performance of minimal basis set (semi-empirical) methods are discussed.

  10. The joint inversion of phase dispersion curves and receiver functions at the margin of East European Craton

    Science.gov (United States)

    Chrapkiewicz, Kajetan; Wilde-Piórko, Monika; Polkowski, Marcin

    2017-04-01

    For the first time a joint inversion of Rayleigh-wave phase velocity dispersion curves and P receiver functions has been applied to study the south-western margin of East European Craton (EEC) in Poland. The area of investigation lies in the vicinity of Trans-European Suture Zone (TESZ) regarded as the most prominent lithospheric boundary in Europe separating the Precambrian EEC from assemblage of Phanerozoic-accreted terranes (e.g. Pharaoh, 1999). While the sedimentary and crystalline crust of EEC's margin has been precisely recognized with the borehole and refraction data compilation (Grad et al., 2016), the structure of lithosphere-asthenosphere boundary (LAB) underneath remains poorly understood. To address this issue, the passive seismic experiment „13 BB Star" (2013-2016) was carried out in northern Poland - just at the margin of EEC. For each station of „13 BB Star" network we obtained a credible 1-D shear-wave velocity model with linearized damped least-squares inversion (Herrmann, 2013) down to the depth of 250 km. The joint inversion of receiver functions and surface-wave dispersion curves has proved to be a natural approach when inferring the nature of cratonic LAB (e.g. Bodin et al., 2014). It's sensitive to both absolute velocities and sharp discontinuities and thus provides a better vertical resolution compared to surface wave data alone. The results indicate the presence of steady 4 per cent grow in the shear-wave velocity between 120 and 180 km depth and gradual 6 per cent drop over 180-220 km depth range. The latter may be interpreted as the LAB with depth and absolute-velocity change similar to those reported for other cratons (Kind et al., 2012). National Science Centre Poland provided financial support for this work by NCN grant DEC-2011/02/A/ST10/00284.

  11. Phase I clinical study on sup 99m Tc-GSA, a new agent for functional imaging of the liver

    Energy Technology Data Exchange (ETDEWEB)

    Torizuka, Kanji (Fukui Medical School, Matsuoka (Japan)); Ha-Kawa, San Kil; Ikekubo, Katsuji; Suga, Yutaka; Tanaka, Yoshimasa; Hino, Megumu; Ito, Hidetomi; Yamamoto, Kazutaka; Yonekura, Yoshiharu

    1991-11-01

    Technetium-99m-DTPA-galactosyl human serum albumin ({sup 99m}Tc-GSA) is a new radiopharmaceutical which binds to the asialoglycoprotein receptors located specifically on the hepatocytes. Phase I study of {sup 99m}Tc-GSA was performed on seven normal volunteers, who were intravenously injected with 185 MBq (5 mCi) and 1-10 mg of {sup 99m}Tc-GSA. None of adverse reactions, abnormal findings of laboratory test and anti-{sup 99m}Tc-GSA antibody production was recognized. The livers were clearly visualized in all subjects. In the pharmacokinetic analyses on five subjects, {sup 99m}Tc-GSA was rapidly taken up by the livers immediately after the injection and was slowly excreted through the biliary tracts and the urinary tracts. Dose-dependency which is a specific feature for the receptor-mediated agents was observed; the blood clearances of {sup 99m}Tc-GSA were prolonged in proportion to the injected ligand doses. These results suggest that {sup 99m}Tc-GSA may be a potential agent for evaluating hepatic functions based on the hepatic receptor quantities. (author).

  12. Spherical agarose-coated magnetic nanoparticles functionalized with a new salen for magnetic solid-phase extraction of uranyl ion

    International Nuclear Information System (INIS)

    Serenjeh, Fariba Nazari; Hashemi, Payman; Ghiasvand, Ali Reza; Naeimi, Hossein; Zakerzadeh, Elham

    2016-01-01

    The authors describe a method for magnetic solid phase extraction of uranyl ions from water samples. It is based on the use of spherical agarose-coated magnetic nanoparticles along with magnetic field agitation. The salen type Schiff base N,N’-bis(4-hydroxysalicylidene)-1,2-phenylenediamine was synthesized from resorcinol in two steps and characterized by infrared and nucleic magnetic resonance spectroscopies. The particles were then activated by an epichlorohydrin method and functionalized with the Schiff base which acts as a selective ligand for the extraction of UO 2 (II). Following preconcentration and elution with HCl, the ions were quantified by spectrophotometry using Arsenazo III as the indicator. The effects of pH value, ionic strength and amount of the adsorbent on the extraction of UO 2 (II) were optimized by a multivariate central composite design method. Six replicate analyses under optimized conditions resulted in a recovery of 96.6 % with a relative standard deviation of 3.4 % for UO 2 (II). The detection limit of the method (at a signal-to-noise ratio of 3σ) is 10 μg L -1 . The method was successfully applied to the determination of UO 2 (II) in spiked water samples. (author)

  13. Road load simulator tests of the Gould phase 1 functional model silicon controlled rectifier ac motor controller for electric vehicles

    Science.gov (United States)

    Gourash, F.

    1984-01-01

    The test results for a functional model ac motor controller for electric vehicles and a three-phase induction motor which were dynamically tested on the Lewis Research Center road load simulator are presented. Results show that the controller has the capability to meet the SAE-J227a D cycle test schedule and to accelerate a 1576-kg (3456-lb) simulated vehicle to a cruise speed of 88.5 km/hr (55 mph). Combined motor controller efficiency is 72 percent and the power inverter efficiency alone is 89 percent for the cruise region of the D cycle. Steady state test results for motoring, regeneration, and thermal data obtained by operating the simulator as a conventional dynamometer are in agreement with the contractor's previously reported data. The regeneration test results indicate that a reduction in energy requirements for urban driving cycles is attainable with regenerative braking. Test results and data in this report serve as a data base for further development of ac motor controllers and propulsion systems for electric vehicles. The controller uses state-of-the-art silicon controlled rectifier (SCR) power semiconductors and microprocessor-based logic and control circuitry. The controller was developed by Gould Laboratories under a Lewis contract for the Department of Energy's Electric and Hybrid Vehicle program.

  14. Road load simulator tests of the Gould phase 1 functional model silicon controlled rectifier ac motor controller for electric vehicles

    Science.gov (United States)

    Gourash, F.

    1984-02-01

    The test results for a functional model ac motor controller for electric vehicles and a three-phase induction motor which were dynamically tested on the Lewis Research Center road load simulator are presented. Results show that the controller has the capability to meet the SAE-J227a D cycle test schedule and to accelerate a 1576-kg (3456-lb) simulated vehicle to a cruise speed of 88.5 km/hr (55 mph). Combined motor controller efficiency is 72 percent and the power inverter efficiency alone is 89 percent for the cruise region of the D cycle. Steady state test results for motoring, regeneration, and thermal data obtained by operating the simulator as a conventional dynamometer are in agreement with the contractor's previously reported data. The regeneration test results indicate that a reduction in energy requirements for urban driving cycles is attainable with regenerative braking. Test results and data in this report serve as a data base for further development of ac motor controllers and propulsion systems for electric vehicles. The controller uses state-of-the-art silicon controlled rectifier (SCR) power semiconductors and microprocessor-based logic and control circuitry. The controller was developed by Gould Laboratories under a Lewis contract for the Department of Energy's Electric and Hybrid Vehicle program.

  15. Development of carbon nanotube modified cement paste with microencapsulated phase-change material for structural-functional integrated application.

    Science.gov (United States)

    Cui, Hongzhi; Yang, Shuqing; Memon, Shazim Ali

    2015-04-10

    Microencapsulated phase-change materials (MPCM) can be used to develop a structural-functional integrated cement paste having high heat storage efficiency and suitable mechanical strength. However, the incorporation of MPCM has been found to degrade the mechanical properties of cement based composites. Therefore, in this research, the effect of carbon nanotubes (CNTs) on the properties of MPCM cement paste was evaluated. Test results showed that the incorporation of CNTs in MPCM cement paste accelerated the cement hydration reaction. SEM micrograph showed that CNTs were tightly attached to the cement hydration products. At the age of 28 days, the percentage increase in flexural and compressive strength with different dosage of CNTs was found to be up to 41% and 5% respectively. The optimum dosage of CNTs incorporated in MPCM cement paste was found to be 0.5 wt %. From the thermal performance test, it was found that the cement paste panels incorporated with different percentages of MPCM reduced the temperature measured at the center of the room by up to 4.6 °C. Inverse relationship was found between maximum temperature measured at the center of the room and the dosage of MPCM.

  16. Development of Carbon Nanotube Modified Cement Paste with Microencapsulated Phase-Change Material for Structural–Functional Integrated Application

    Directory of Open Access Journals (Sweden)

    Hongzhi Cui

    2015-04-01

    Full Text Available Microencapsulated phase-change materials (MPCM can be used to develop a structural–functional integrated cement paste having high heat storage efficiency and suitable mechanical strength. However, the incorporation of MPCM has been found to degrade the mechanical properties of cement based composites. Therefore, in this research, the effect of carbon nanotubes (CNTs on the properties of MPCM cement paste was evaluated. Test results showed that the incorporation of CNTs in MPCM cement paste accelerated the cement hydration reaction. SEM micrograph showed that CNTs were tightly attached to the cement hydration products. At the age of 28 days, the percentage increase in flexural and compressive strength with different dosage of CNTs was found to be up to 41% and 5% respectively. The optimum dosage of CNTs incorporated in MPCM cement paste was found to be 0.5 wt %. From the thermal performance test, it was found that the cement paste panels incorporated with different percentages of MPCM reduced the temperature measured at the center of the room by up to 4.6 °C. Inverse relationship was found between maximum temperature measured at the center of the room and the dosage of MPCM.

  17. A Monte Carlo study of absorbed dose distributions in both the vapor and liquid phases of water by intermediate energy electrons based on different condensed-history transport schemes

    International Nuclear Information System (INIS)

    Bousis, C; Emfietzoglou, D; Hadjidoukas, P; Nikjoo, H

    2008-01-01

    Monte Carlo transport calculations of dose point kernels (DPKs) and depth dose profiles (DDPs) in both the vapor and liquid phases of water are presented for electrons with initial energy between 10 keV and 1 MeV. The results are obtained by the MC4 code using three different implementations of the condensed-history technique for inelastic collisions, namely the continuous slowing down approximation, the mixed-simulation with δ-ray transport and the addition of straggling distributions for soft collisions derived from accurate relativistic Born cross sections. In all schemes, elastic collisions are simulated individually based on single-scattering cross sections. Electron transport below 10 keV is performed in an event-by-event mode. Differences on inelastic interactions between the vapor and liquid phase are treated explicitly using our recently developed dielectric response function which is supplemented by relativistic corrections and the transverse contribution. On the whole, the interaction coefficients used agree to better than ∼5% with NIST/ICRU values. It is shown that condensed phase effects in both DPKs and DDPs practically vanish above 100 keV. The effect of δ-rays, although decreases with energy, is sizeable leading to more diffused distributions, especially for DPKs. The addition of straggling for soft collisions is practically inconsequential above a few hundred keV. An extensive benchmarking with other condensed-history codes is provided

  18. The Impact of Endurance Training on Functional Parameters During the Preparation Phase among Cross-Country Skiers

    Directory of Open Access Journals (Sweden)

    Žiška Peter

    2016-05-01

    Full Text Available In the study, we have tried to demonstrate the effect of endurance training on changes in functional parameters during the preparation phase (12-week mesocycle among cross-country skiers. The group consisted of 10 male cross-country skiers (age: 21.4 ±5 year who completed control (1st 6 week mesocycle and experimental period (2nd 6 week mesocycle.We focused on the following time-varying parameters: changes in maximal oxygen uptake (VO2max, the level of aerobic (AeT and anaerobic thresholds (AT, maximum heart rate (HRmax and performance on the running treadmill. The intra-individual monitoring of each athlete revealed statistical significance of VO2max (mid_VO2max = 69.48 ± 5.72 l.kg-1.min-1, post_ VO2max = 70.96 ± 5.67 ml.kg-1.min-1; p≤0.05 and the level of AT (mid_AT = 86.2 ± 5.43 %, post_AT = 87.8 ± 5.59 %; p≤0.01 the performance on the running treadmill (mid_t = 14:54 ± 1:43 min., post_t = 15:30 ± 1:50 min.; p≤0.05.The significant changes were recorded in the AeT(pre_AeT = 70.3 ± 7.56 %, mid_AeT = 72.5 ± 7.59 %; p≤0.05 in theHRmax(pre_HRmax = 190 ± 8.04 bpm, mid_HRmax = 189 bpm, post_HRmax = 188 ± 7.34 bpm; p = n.s. during control period. We assume that the significant differences occurred as a result of adaptation changes due to training stimuli, which were induced by changes in functional parameters. Increased training volume in zone lower level of oxygen regime (A1, upper level of oxygen regime (A2 and upper level of lactate tolerance(T2 during experimental period elicited changes which reflected the increase functional parameters and performance on the running treadmill compared to that of control period.

  19. Analysis of the functional state of students in the process of healthy training exercises in different phases of the ovarian-menstrual cycle

    Directory of Open Access Journals (Sweden)

    N.V. Petrenko

    2017-11-01

    Full Text Available Aim: to substantiate the application of a rational program of health-training sessions in the educational process of physical education of students in different phases of the ovarian-menstrual cycle. Material: in study participated students (n=127, who did not have deviations in health (the main medical group. According to the results of the tests were determined: heart rate; blood pressure; vital capacity of the lungs. To determine physical performance was used Harvard step-test. Physical exercises from the main means of health fitness were used differentially and dosed. Results: It was established that the consideration in the phases of the ovarian-menstrual cycle of indicators of the functional state, changes in well-being and working capacity give an opportunity: planning loads in the training process; adjustment of volume and intensity of loads. We recommend to schedule the load of our program as follows: in the menstrual phase - the development of flexibility (moderate load; in the postmenstrual phase - development of coordination, overall endurance; in ovulatory - speed development; in postovulatory - development of special endurance; in premenstrual - the development of strength, flexibility. In the postmenstrual and postovulatory phase, a high level of physical working capacity, functional state of the cardiopulmonary system has been registered. It also has a positive effect on body weight correction in the women students. Conclusions: When developing programs of health training sessions with women students it is necessary to take into account the phases of the ovarian-menstrual cycle.

  20. Detection of seismic phases by wavelet transform. Dependence of its performance on wavelet functions; Wavelet henkan ni yoru jishinha no iso kenshutsu. Wavelet ni yoru sai

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, X.; Yamazaki, K. [Tokyo Gakugei University, Tokyo (Japan); Oguchi, Y. [Hosei University, Tokyo (Japan)

    1997-10-22

    A study has been performed on wavelet analysis of seismic waves. In the wavelet analysis of seismic waves, there is a possibility that the results according to different wavelet functions may come out with great difference. The study has carried out the following analyses: an analysis of amplitude and phase using wavelet transform which uses wavelet function of Morlet on P- and S-waves generated by natural earthquakes and P-wave generated by an artificial earthquake, and an analysis using continuous wavelet transform, which uses a constitution of complex wavelet function constructed by a completely diagonal scaling function of Daubechies and the wavelet function. As a result, the following matters were made clear: the result of detection of abnormal components or discontinuity depends on the wavelet function; if the Morlet wavelet function is used to properly select angular frequency and scale, equiphase lines in a phase scalogram concentrate on the discontinuity; and the result of applying the complex wavelet function is superior to that of applying the wavelet function of Morlet. 2 refs., 5 figs.

  1. Ab initio density functional theory investigation of the structural, electronic and optical properties of Ca{sub 3}Sb{sub 2} in hexagonal and cubic phases

    Energy Technology Data Exchange (ETDEWEB)

    Arghavani Nia, Borhan, E-mail: b.arghavani@gmail.com [Department of Physics, Kermanshah Branch, Islamic Azad University, Kermanshah (Iran, Islamic Republic of); Sedighi, Matin [Department of Physics, Kermanshah Branch, Islamic Azad University, Kermanshah (Iran, Islamic Republic of); Shahrokhi, Masoud [Young Researchers and Elite Club, Kermanshah Branch, Islamic Azad University, Kermanshah (Iran, Islamic Republic of); Moradian, Rostam [Nano-Science and Nano-Technology Research Center, Razi University, Kermanshah (Iran, Islamic Republic of); Computational Physics Science Research Laboratory, Department of Nano-Science, Institute for Studies in Theoretical Physics and Mathematics (IPM), P.O. Box 19395-1795, Tehran (Iran, Islamic Republic of)

    2013-11-15

    A density functional theory study of structural, electronical and optical properties of Ca{sub 3}Sb{sub 2} compound in hexagonal and cubic phases is presented. In the exchange–correlation potential, generalized gradient approximation (PBE-GGA) has been used to calculate lattice parameters, bulk modulus, cohesive energy, dielectric function and energy loss spectra. The electronic band structure of this compound has been calculated using the above two approximations as well as another form of PBE-GGA, proposed by Engle and Vosko (EV-GGA). It is found that the hexagonal phase of Ca{sub 3}Sb{sub 2} has an indirect gap in the Γ→N direction; while in the cubic phase there is a direct-gap at the Γ point in the PBE-GGA and EV-GGA. Effects of applying pressure on the band structure of the system studied and optical properties of these systems were calculated. - Graphical abstract: A density functional theory study of structural, electronic and optical properties of Ca{sub 3}Sb{sub 2} compound in hexagonal and cubic phases is presented. Display Omitted - Highlights: • Physical properties of Ca{sub 3}Sb{sub 2} in hexagonal and cubic phases are investigated. • It is found that the hexagonal phase is an indirect gap semiconductor. • Ca{sub 3}Sb{sub 2} is a direct-gap semiconductor at the Γ point in the cubic phase. • By increasing pressure the semiconducting band gap and anti-symmetry gap are decreased.

  2. Characterization of solar cells for space applications. Volume 14: Electrical characteristics of Hughes liquid phase epitaxy gallium arsenide solar cells as a function of intensity, temperature and irradiation

    Science.gov (United States)

    Anspaugh, B. E.; Downing, R. G.; Miyahira, T. F.; Weiss, R. S.

    1981-01-01

    Electrical characteristics of liquid phase epitaxy, P/N gallium aluminum arsenide solar cells are presented in graphical and tabular format as a function of solar illumination intensity and temperature. The solar cells were exposed to 1 MeV electron fluences of, respectively, 0, one hundred trillion, one quadrillion, and ten quadrillion e/sq cm.

  3. GaAs mixed signal multi-function X-band MMIC with 7 bit phase and amplitude control and integrated serial to parallel converter

    NARCIS (Netherlands)

    Boer, A. de; Mouthaan, K.

    2000-01-01

    The design and measured performance of a GaAs multi-function X-band MMIC for spacebased synthetic aperture radar (SAR) applications with 7-bit phase and amplitude control and integrated serial to parallel converter (including level conversion) is presented. The main application for the

  4. The focus of family members' functioning in the acute phase of traumatic coma; Part Two: Protecting from suffering and protecting what remains to rebuild life

    NARCIS (Netherlands)

    Verhaeghe, S.T.L.; van Zuuren, F.J.; Defloor, T.; Duijnstee, M.S.H.; Grypdonck, M.H.F.

    2010-01-01

    Aims.  The identification and description of the basic psychological process linked with the focus of family members’ functioning during the acute phase of traumatic coma. Background.  Earlier research learned that hope is a core category in coping with traumatic coma. Hope seems to be the drive to

  5. [Functional state of a sphingomyeline cycle and free radical lipid oxidation activity of a rat's liver during different phases of starvation].

    Science.gov (United States)

    Kuz'menko, D I; Burov, P G; Serebrov, V Iu; Faĭt, E A; Perevozchikova, T V

    2012-01-01

    The functional state of a sphingomyeline cycle and character of its mutual relations with the processes of free radical lipid oxidation during starvation of animals without any restriction of access to drinking water at 1, 2, 3 day (I phase) and 6 day (II phase of starvation) were studied at the liver of rats. The maximal values of the ceramide/sphingomyeline ratio and activity neutral sphingomyelinase and executive caspase-3 were reached in a liver of animals at the 3rd day of starvation. From the 3rd day of starvation the concentration of the tumour necrosis factor-alpha which is one of activators neutral sphingomyelinase was increase in rats blood serum. During the extent of large part of the I phase of starvation the intensity of free radical lipid peroxidation in a liver had almost the same level as in control group--that was a result of the high-grade functioning of antioxidant defense system. After transition the I phase of starvation into the II phase (6 day of experiment) the oxidative stress was developed as result of an exhaustion of system antioxidant defense potential in a liver. The results of this data can testify that during I phase of starvation in a liver the conditions was raised for display of the ceramide-mediated proapoptotic signalling. We assume that ceramide-mediated apoptosis is one of mechanisms of optimization of liver cellular population at the frames of metabolic adaptation. The I phase of starvation in a liver proves by the ceramide-mediated proapoptotic signaling developing. During the II phase of starvation the oxidative stress process were prevailed.

  6. Enhancing micro-seismic P-phase arrival picking: EMD-cosine function-based denoising with an application to the AIC picker

    Science.gov (United States)

    Shang, Xueyi; Li, Xibing; Morales-Esteban, A.; Dong, Longjun

    2018-03-01

    Micro-seismic P-phase arrival picking is an elementary step into seismic event location, source mechanism analysis, and seismic tomography. However, a micro-seismic signal is often mixed with high frequency noises and power frequency noises (50 Hz), which could considerably reduce P-phase picking accuracy. To solve this problem, an Empirical Mode Decomposition (EMD)-cosine function denoising-based Akaike Information Criterion (AIC) picker (ECD-AIC picker) is proposed for picking the P-phase arrival time. Unlike traditional low pass filters which are ineffective when seismic data and noise bandwidths overlap, the EMD adaptively separates the seismic data and the noise into different Intrinsic Mode Functions (IMFs). Furthermore, the EMD-cosine function-based denoising retains the P-phase arrival amplitude and phase spectrum more reliably than any traditional low pass filter. The ECD-AIC picker was tested on 1938 sets of micro-seismic waveforms randomly selected from the Institute of Mine Seismology (IMS) database of the Chinese Yongshaba mine. The results have shown that the EMD-cosine function denoising can effectively estimate high frequency and power frequency noises and can be easily adapted to perform on signals with different shapes and forms. Qualitative and quantitative comparisons show that the combined ECD-AIC picker provides better picking results than both the ED-AIC picker and the AIC picker, and the comparisons also show more reliable source localization results when the ECD-AIC picker is applied, thus showing the potential of this combined P-phase picking technique.

  7. Preparation of magnetic chitosan and graphene oxide-functional guanidinium ionic liquid composite for the solid-phase extraction of protein

    International Nuclear Information System (INIS)

    Ding, Xueqin; Wang, Yuzhi; Wang, Ying; Pan, Qi; Chen, Jing; Huang, Yanhua; Xu, Kaijia

    2015-01-01

    Highlights: • A strategy for the solid-phase extraction of protein based on magnetic chitosan and graphene oxide-functional guanidinium ionic liquids. • Trypsin, lysozyme, ovalbumin and bovine serum albumin were used as the analyst. • The possibility of reusability and regeneration has been evaluated. - Abstract: A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been synthesized, and then magnetic chitosan graphene oxide (MCGO) composite has been prepared and coated with these functional guanidinium ionic liquids to extract protein by magnetic solid-phase extraction. MCGO-functional guanidinium ionic liquid has been characterized by vibrating sample magnetometer, field emission scanning electron microscopy, X-ray diffraction spectrometer and Fourier transform infrared spectrometer. After extraction, the concentrations of protein were determined by measuring the absorbance at 278 nm using an ultra violet visible spectrophotometer. The advantages of MCGO-functional guanidinium ionic liquid in protein extraction were compared with magnetic chitosan, graphene oxide, MCGO and MCGO-ordinary imidazolium ionic liquid. The proposed method has been applied to extract trypsin, lysozyme, ovalbumin and bovine serum albumin. A comprehensive study of the adsorption conditions such as the concentration of protein, the amount of MCGO-functional guanidinium ionic liquid, the pH, the temperature and the extraction time were also presented. Moreover, the MCGO-functional guanidinium ionic liquid can be easily regenerated, and the extraction capacity was about 94% of the initial one after being used three times

  8. Preparation of magnetic chitosan and graphene oxide-functional guanidinium ionic liquid composite for the solid-phase extraction of protein

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Xueqin; Wang, Yuzhi, E-mail: wyzss@hnu.edu.cn; Wang, Ying; Pan, Qi; Chen, Jing; Huang, Yanhua; Xu, Kaijia

    2015-02-25

    Highlights: • A strategy for the solid-phase extraction of protein based on magnetic chitosan and graphene oxide-functional guanidinium ionic liquids. • Trypsin, lysozyme, ovalbumin and bovine serum albumin were used as the analyst. • The possibility of reusability and regeneration has been evaluated. - Abstract: A series of novel cationic functional hexaalkylguanidinium ionic liquids and anionic functional tetraalkylguanidinium ionic liquids have been synthesized, and then magnetic chitosan graphene oxide (MCGO) composite has been prepared and coated with these functional guanidinium ionic liquids to extract protein by magnetic solid-phase extraction. MCGO-functional guanidinium ionic liquid has been characterized by vibrating sample magnetometer, field emission scanning electron microscopy, X-ray diffraction spectrometer and Fourier transform infrared spectrometer. After extraction, the concentrations of protein were determined by measuring the absorbance at 278 nm using an ultra violet visible spectrophotometer. The advantages of MCGO-functional guanidinium ionic liquid in protein extraction were compared with magnetic chitosan, graphene oxide, MCGO and MCGO-ordinary imidazolium ionic liquid. The proposed method has been applied to extract trypsin, lysozyme, ovalbumin and bovine serum albumin. A comprehensive study of the adsorption conditions such as the concentration of protein, the amount of MCGO-functional guanidinium ionic liquid, the pH, the temperature and the extraction time were also presented. Moreover, the MCGO-functional guanidinium ionic liquid can be easily regenerated, and the extraction capacity was about 94% of the initial one after being used three times.

  9. Gender differences in quality of life and functional disability for depression outpatients with or without residual symptoms after acute phase treatment in China.

    Science.gov (United States)

    Zhao, Na; Wang, Xiaohong; Wu, Wenyuan; Hu, Yongdong; Niu, Yajuan; Wang, Xueyi; Gao, Chengge; Zhang, Ning; Fang, Yiru; Huang, Jizhong; Liu, Tiebang; Jia, Fujun; Zhu, Xuequan; Hu, Jian; Wang, Gang

    2017-09-01

    Depression is associated with substantial personal suffering and reduced quality of life and functioning. The aim of this study was to investigate gender differences on quality of life and functional impairment of outpatients with depression after acute phase treatment. 1503 depression outpatients were recruited from eleven hospitals in China. Subjects were evaluated with sociodemographic characteristics, history and self-report instruments, related to severity of symptoms, function and quality of life. All data were analyzed to determine the gender differences. Men had a younger age at onset and the first onset age, higher education compared to women in total patients and with or without residual symptoms group. Using regression analysis, it was found that gender was significantly statistically related to severity scores of SDS and had no correlation with Q-LES-Q-SF total scores. In the residual symptoms group, greater functional impairment was noted by men in the area of work and social life. Significant gender differences of mood, work and sexual life in quality of life were observed. This is a cross-sectional study of depressed outpatients and duration of acute phase treatment may not an adequate time to measure changes. Depression appears to affect men more seriously than women after acute phase treatment. Men had a younger age at onset and the first onset age, higher education, more functional impairment and lower satisfaction of quality of life in mood, work and sexual life. Gender differences affect acute treatment, remission and recovery. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. The Gas-Phase Heats of Formation of n-Alkanes as a Function of the Electrostatic Potential Extrema on their Molecular Surfaces

    Directory of Open Access Journals (Sweden)

    Fakhr M. Abu-Awwad

    2004-01-01

    Full Text Available The hybrid density functional B3LYP is employed to map the molecular electrostatic potentials on the surfaces of twenty normal alkanes, (Cn H2n+2, n = 1-20. It is shown that gas-phase heats of formation of the alkanes can be represented quantitatively in terms of the potential, where a general equation of the heat of formation is introduced as a function of potentials' extrema, VS,min and VS,max with average absolute error of 0.028 kcal/mol and a standard deviation of 0.048 kcal/mol. This should be viewed as a success of the B3LYP functional and the molecular surface electrostatic potential as tools of chemistry. The predicted gas-phase heats of formation of thirty normal alkanes (n = 21-50 are reproduced and compared to their experimental counterparts when available.

  11. Impact of stance phase microprocessor-controlled knee prosthesis on ramp negotiation and community walking function in K2 level transfemoral amputees.

    Science.gov (United States)

    Burnfield, Judith M; Eberly, Valerie J; Gronely, Joanne K; Perry, Jacquelin; Yule, William Jared; Mulroy, Sara J

    2012-03-01

    Microprocessor controlled prosthetic knees (MPK) offer opportunities for improved walking stability and function, but some devices' swing phase features may exceed needs of users with invariable cadence. One MPK offers computerized control of only stance (C-Leg Compact). To assess Medicare Functional Classification Level K2 walkers' ramp negotiation performance, function and balance while using a non-MPK (NMPK) compared to the C-Leg Compact. Crossover. Gait while ascending and descending a ramp (stride characteristics, kinematics, electromyography) and function were assessed in participant's existing NMPK and again in the C-Leg Compact following accommodation. Ramp ascent and descent were markedly faster in the C-Leg Compact compared to the NMPK (p ≤ 0.006), owing to increases in stride length (p ≤ 0.020) and cadence (p ≤ 0.020). Residual limb peak knee flexion and ankle dorsiflexion were significantly greater (12.9° and 4.9° more, respectively) during single limb support while using the C-Leg Compact to descend ramps. Electromyography (mean, peak) did not differ significantly between prosthesis. Function improved in the C-Leg Compact as evidenced by a significantly faster Timed Up and Go and higher functional questionnaire scores. Transfemoral K2 walkers exhibited significantly improved function and balance while using the stance-phase only MPK compared to their traditional NMPK.

  12. Comparison of the site occupancies determined by combined Rietveld refinement and density functional theory calculations: example of the ternary Mo-Ni-Re σ phase.

    Science.gov (United States)

    Yaqoob, Khurram; Crivello, Jean-Claude; Joubert, Jean-Marc

    2012-03-05

    The site occupancies of the Mo-Ni-Re σ phase have been studied as a function of the composition in the ternary homogeneity domain by both experimental measurements and calculations. Because of the possible simultaneous occupancy of three elements on the five sites of the crystal structure, the experimental determination of the site occupancies was achieved by using combined Rietveld refinement of X-ray and neutron diffraction data, whereas calculation of the site occupancies was carried out by using the density functional theory results of every ordered (i.e., 3(5) = 243) configuration appearing in the ternary system. A comparison of the experimental and calculation results showed good agreement, which suggests that the topologically close-packed phases, such as the σ phase, could be described by the Bragg-Williams approximation (i.e., ignoring the short-range-order contributions). On the other hand, the atomic distribution on different crystallographic sites of the Mo-Ni-Re σ phase was found to be governed by the atomic sizes. Ni, having the smallest atomic size, showed a preference for low-coordination-number (CN) sites, whereas Mo, being the largest in atomic size, preferred occupying high-CN sites. However, the preference of Re, having intermediate atomic size, varied depending on the composition, and a clear reversal in the preference of Re as a function of the composition was evidenced in both the calculated and experimental site-occupancy results.

  13. Interrelation between the changes of phase functions of cardiac muscle contraction and biochemical processes as an algorithm for identifying local pathologies in cardiovascular system

    Directory of Open Access Journals (Sweden)

    Yury V. Fedosov

    2012-11-01

    Full Text Available Aims The interrelation between hemodynamic changes, functions of the cardiovascular system and biochemical reactions in the cells of the heart muscle is investigated in the present paper. Materials and methods Several methods were used to influence the metabolism processes in the myocardium. The changes in the phase functions of contraction of different cardiac muscles were recorded. In order to have comprehensive influence on the metabolism processes, normalization of the acid-base balance was performed. L-carnitine and octolipen were used to affect the lipid metabolism. Results Phase blood volumes that are characteristic of hemodynamics changed in the course of treatment to reach their nornal values. The ECG shape during the heart cycle phases also changed to reach the norm. The initial ECG shape describing Brugada syndrome almost reached its normal value. Extrasystole disappeared therewith. Conclusion The method of the heart cycle phase analysis enables monitoring any changes in hemodynamics and functions of the cardiovascular system. The method can be used for identifying the original cause of pathologies and efficient monitoring of the treatment progress.

  14. Preparation of a silica stationary phase co-functionalized with Wulff-type phenylboronate and C12 for mixed-mode liquid chromatography.

    Science.gov (United States)

    Li, Hengye; Zhang, Xuemeng; Zhang, Lin; Wang, Xiaojin; Kong, Fenying; Fan, Dahe; Li, Lei; Wang, Wei

    2017-04-15

    A silica stationary phase was designed and synthesized through the co-functionalization of silica with Wulff-type phenylboronate and C12 for mixed-mode liquid chromatography applications. The as-synthesized stationary phase was characterized by elemental analysis and Fourier Transform-InfraRed Spectroscopy (FT-IR). Retention mechanisms, including boronate affinity (BA), reversed-phase (RP) and anion-exchange (AE), were involved. Retention mechanism switching was easily realized by adjustment of the mobile phase constitution. Cis-diol compounds could be selectively captured under neutral conditions in BA mode and off-line separated in RP mode. Neutral, basic, acidic and amphiprotic compounds were chromatographed on the column in RP chromatography, while inorganic anions were chromatographed in AE chromatography to characterize the mixed-mode nature of the prepared stationary phase. In addition, the RP performance was compared with an octadecyl silica column in terms of column efficiency (N/m), asymmetry factor (A f ), retention factor (k) and resolution (Rs). The prepared stationary phase offered multiple interactions with analytes in addition to hydrophobic interactions under RP elution conditions. Based on the mixed-mode properties, off-line 2D-LC, for selective capture and separation of urinary nucleosides, was successfully realized on a single column, demonstrating its powerful application potential for complex samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Synthesis of multi-wavelength temporal phase-shifting algorithms optimized for high signal-to-noise ratio and high detuning robustness using the frequency transfer function

    OpenAIRE

    Servin, Manuel; Padilla, Moises; Garnica, Guillermo

    2016-01-01

    Synthesis of single-wavelength temporal phase-shifting algorithms (PSA) for interferometry is well-known and firmly based on the frequency transfer function (FTF) paradigm. Here we extend the single-wavelength FTF-theory to dual and multi-wavelength PSA-synthesis when several simultaneous laser-colors are present. The FTF-based synthesis for dual-wavelength PSA (DW-PSA) is optimized for high signal-to-noise ratio and minimum number of temporal phase-shifted interferograms. The DW-PSA synthesi...

  16. Towards the description of the phase behavior of electrolyte solutions in slit-like pores. Density functional approach for the restricted primitive model

    Directory of Open Access Journals (Sweden)

    O.Pizio

    2004-01-01

    Full Text Available We develop a density functional approach for the phase behavior of the restricted primitive model for electrolyte solutions confined to slit-like pores. The theory permits to evaluate the effects of confinement on the ionic vapor - ionic liquid coexistence envelope. We have shown that due to confinement in pores with uncharged walls the critical temperature of the model decreases compared to the bulk. Also the coexistence envelope of the transition is narrower in comparison to the bulk model. The transition between dense and dilute phase represents capillary evaporation. We have analyzed changes of the density profiles of ions during transition. Possible extensions of this study are discussed.

  17. Spin-adapted open-shell random phase approximation and time-dependent density functional theory. I. Theory.

    Science.gov (United States)

    Li, Zhendong; Liu, Wenjian

    2010-08-14

    The spin-adaptation of single-reference quantum chemical methods for excited states of open-shell systems has been nontrivial. The primary reason is that the configuration space, generated by a truncated rank of excitations from only one component of a reference multiplet, is spin-incomplete. Those "missing" configurations are of higher ranks and can, in principle, be recaptured by a particular class of excitation operators. However, the resulting formalisms are then quite involved and there are situations [e.g., time-dependent density functional theory (TD-DFT) under the adiabatic approximation] that prevent one from doing so. To solve this issue, we propose here a tensor-coupling scheme that invokes all the components of a reference multiplet (i.e., a tensor reference) rather than increases the excitation ranks. A minimal spin-adapted n-tuply excited configuration space can readily be constructed by tensor products between the n-tuple tensor excitation operators and the chosen tensor reference. Further combined with the tensor equation-of-motion formalism, very compact expressions for excitation energies can be obtained. As a first application of this general idea, a spin-adapted open-shell random phase approximation is first developed. The so-called "translation rule" is then adopted to formulate a spin-adapted, restricted open-shell Kohn-Sham (ROKS)-based TD-DFT (ROKS-TD-DFT). Here, a particular symmetry structure has to be imposed on the exchange-correlation kernel. While the standard ROKS-TD-DFT can access only excited states due to singlet-coupled single excitations, i.e., only some of the singly excited states of the same spin (S(i)) as the reference, the new scheme can capture all the excited states of spin S(i)-1, S(i), or S(i)+1 due to both singlet- and triplet-coupled single excitations. The actual implementation and computation are very much like the (spin-contaminated) unrestricted Kohn-Sham-based TD-DFT. It is also shown that spin-contaminated spin

  18. Automated left ventricular diastolic function evaluation from phase-contrast cardiovascular magnetic resonance and comparison with Doppler echocardiography

    Directory of Open Access Journals (Sweden)

    Ladouceur Magalie

    2010-11-01

    Full Text Available Abstract Background Early detection of diastolic dysfunction is crucial for patients with incipient heart failure. Although this evaluation could be performed from phase-contrast (PC cardiovascular magnetic resonance (CMR data, its usefulness in clinical routine is not yet established, mainly because the interpretation of such data remains mostly based on manual post-processing. Accordingly, our goal was to develop a robust process to automatically estimate velocity and flow rate-related diastolic parameters from PC-CMR data and to test the consistency of these parameters against echocardiography as well as their ability to characterize left ventricular (LV diastolic dysfunction. Results We studied 35 controls and 18 patients with severe aortic valve stenosis and preserved LV ejection fraction who had PC-CMR and Doppler echocardiography exams on the same day. PC-CMR mitral flow and myocardial velocity data were analyzed using custom software for semi-automated extraction of diastolic parameters. Inter-operator reproducibility of flow pattern segmentation and functional parameters was assessed on a sub-group of 30 subjects. The mean percentage of overlap between the transmitral flow segmentations performed by two independent operators was 99.7 ± 1.6%, resulting in a small variability ( 0.71 and receiver operating characteristic (ROC analysis revealed their ability to separate patients from controls, with sensitivity > 0.80, specificity > 0.80 and accuracy > 0.85. Slight superiority in terms of correlation with echocardiography (r = 0.81 and accuracy to detect LV abnormalities (sensitivity > 0.83, specificity > 0.91 and accuracy > 0.89 was found for the PC-CMR flow-rate related parameters. Conclusions A fast and reproducible technique for flow and myocardial PC-CMR data analysis was successfully used on controls and patients to extract consistent velocity-related diastolic parameters, as well as flow rate-related parameters. This technique

  19. Phase Transformation and Lattice Parameter Changes of Non-trivalent Rare Earth-Doped YSZ as a Function of Temperature

    Science.gov (United States)

    Jiang, Shengli; Huang, Xiao; He, Zhang; Buyers, Andrew

    2018-01-01

    To examine the effect of doping/co-doping on high-temperature phase compositions of YSZ, stand-alone YSZ and CeO2 and Nb2O5 co-doped YSZ samples were prepared using mechanical alloy and high-temperature sintering. XRD analysis was performed on these samples from room temperature to 1100 °C. The results show that the structure for the co-doped samples tends to be thermally stable when the test temperature is higher than a critical value. Monoclinic phase was dominant in Nb2O5 co-doped YSZ at temperatures lower than 600 °C, while for the YSZ and CeO2 co-doped YSZ, cubic/tetragonal phase was dominant in the whole test temperature range. The lattice parameters for all the samples increase with increasing test temperature generally. The lattice parameters for the two non-trivalent rare earth oxides co-doped YSZ show that the lattice parameter a for the cubic phase of the Ce4+ co-doped YSZ is consistently greater than that of 7YSZ which is related to the presence of larger radius of Ce4+ in the matrix. The lattice parameters a, b, c for the monoclinic phase of Ce4+ co-doped YSZ are much closer to each other than that of the Nb5+ co-doped YSZ, indicating the former has better tendency to form cubic/tetragonal phase, which is desired for vast engineering applications.

  20. A correlative study of CT findings and pulmonary function in patients with pulmonary involvement during the active phase of rheumatoid arthritis

    International Nuclear Information System (INIS)

    Zhu Xiaolei; Xu Defu

    2006-01-01

    Objective: It is a correlative study of CT findings and pulmonary function in patients with pulmonary involvement during the active phase of rheumatoid arthritis. Methods: The CT images of 28 cases of pulmonary involvement during the active phase of rheumatoid arthritis were retrospectively analyzed. The pulmonary abnormalities revealed on CT images including distribution and extend of the lesions were quantitatively analyzed and scored. The correlation of CT scores with the results of pulmonary function tests was compared statistically. Results: Interlobular septa thickening was shown in 16 cases; ground-glass opacification was revealed in 14 cases; irregular lines were found in 11 cases; bronchiolectasis was noted in 7 cases; micro nodules were demonstrated in 4 cases; and honey combing alteration was visualized in 3 cases. The abnormality most frequent seen on CT images was reticular shadow and ground-glass opacification. CT visual score had a negative correlation with pulmonary function. Conclusion: CT visual score provides quantitative evaluation of the pulmonary involvement during the active phase of rheumatoid arthritis, and also indicates the pulmonary function and prognosis as well. (authors)

  1. Phase contrast image synthesis

    DEFF Research Database (Denmark)

    Glückstad, J.

    1996-01-01

    A new method is presented for synthesizing arbitrary intensity patterns based on phase contrast imaging. The concept is grounded on an extension of the Zernike phase contrast method into the domain of full range [0; 2 pi] phase modulation. By controlling the average value of the input phase funct...... function and by choosing appropriate phase retardation at the phase contrast filter, a pure phase to intensity imaging is accomplished. The method presented is also directly applicable in dark field image synthesis....

  2. Periodic Hartree-Fock and hybrid density functional calculations on the metallic and the insulating phase of (EDO-TTF)2PF6.

    Science.gov (United States)

    Linker, Gerrit-Jan; van Loosdrecht, Paul H M; van Duijnen, Piet Th; Broer, Ria

    2015-11-11

    The insulating and conducting phases of (EDO-TTF)2PF6 were studied by all electron, periodic Hartree-Fock and hybrid density functional calculations. Electronic properties, such as the electronic band structure, the density of states and the Fermi surface are discussed in relation to the metal-insulator transition in this material. The nature of conduction is confirmed in both phases from their band structures and density of states. The hybrid DFT band gaps are in good agreement with experiment. Interactions are discussed on the basis of band dispersion in the inter-stack, intra-stack and inter-sheet directions. We discuss the phase transition in terms of the Peierls mechanism and our results fully support this view.

  3. Coherence and phase synchrony analyses of EEG signals in Mild Cognitive Impairment (MCI): A study of functional brain connectivity

    Science.gov (United States)

    Handayani, Nita; Haryanto, Freddy; Khotimah, Siti Nurul; Arif, Idam; Taruno, Warsito Purwo

    2018-03-01

    This paper presents an EEG study for coherence and phase synchrony in mild cognitive impairment (MCI) subjects. MCI is characterized by cognitive decline, which is an early stage of Alzheimer's disease (AD). AD is a neurodegenerative disorder with symptoms such as memory loss and cognitive impairment. EEG coherence is a statistical measure of correlation between signals from electrodes spatially separated on the scalp. The magnitude of phase synchrony is expressed in the phase locking value (PLV), a statistical measure of neuronal connectivity in the human brain. Brain signals were recorded using an Emotiv Epoc 14-channel wireless EEG at a sampling frequency of 128 Hz. In this study, we used 22 elderly subjects consisted of 10 MCI subjects and 12 healthy subjects as control group. The coherence between each electrode pair was measured for all frequency bands (delta, theta, alpha and beta). In the MCI subjects, the value of coherence and phase synchrony was generally lower than in the healthy subjects especially in the beta frequency. A decline of intrahemisphere coherence in the MCI subjects occurred in the left temporo-parietal-occipital region. The pattern of decline in MCI coherence is associated with decreased cholinergic connectivity along the path that connects the temporal, occipital, and parietal areas of the brain to the frontal area of the brain. EEG coherence and phase synchrony are able to distinguish persons who suffer AD in the early stages from healthy elderly subjects.

  4. Calculations of recombination rates for cold 4He atoms from atom-dimer phase shifts and determination of universal scaling functions

    International Nuclear Information System (INIS)

    Shepard, J. R.

    2007-01-01

    Three-body recombination rates for cold 4 He are calculated with a method which exploits the simple relationship between the imaginary part of the atom-dimer elastic scattering phase shift and the S-matrix for recombination. The elastic phase shifts are computed above breakup threshold by solving a three-body Faddeev equation in momentum space with inputs based on a variety of modern atom-atom potentials. Recombination coefficients for the HFD-B3-FCII potential agree very well with the only previously published results. Since the elastic scattering and recombination processes for 4 He are governed by 'Efimov physics', they depend on universal functions of a scaling variable. The computed recombination coefficients for potentials other than HFD-B3-FCII make it possible to determine these universal functions

  5. A density-functional study of the phase diagram of cementite-type (Fe,Mn)3C at absolute zero temperature.

    Science.gov (United States)

    Von Appen, Jörg; Eck, Bernhard; Dronskowski, Richard

    2010-11-15

    The phase diagram of (Fe(1-x) Mn(x))(3)C has been investigated by means of density-functional theory (DFT) calculations at absolute zero temperature. The atomic distributions of the metal atoms are not random-like as previously proposed but we find three different, ordered regions within the phase range. The key role is played by the 8d metal site which forms, as a function of the composition, differing magnetic layers, and these dominate the physical properties. We calculated the magnetic moments, the volumes, the enthalpies of mixing and formation of 13 different compositions and explain the changes of the macroscopic properties with changes in the electronic and magnetic structures by means of bonding analyses using the Crystal Orbital Hamilton Population (COHP) technique. 2010 Wiley Periodicals, Inc.

  6. Glycolipid-based nanostructures with thermal-phase transition behavior functioning as solubilizers and refolding accelerators for protein aggregates.

    Science.gov (United States)

    Kameta, N; Matsuzawa, T; Yaoi, K; Fukuda, J; Masuda, M

    2017-05-03

    The self-assembly of synthetic glycolipids produced nanostructures such as vesicles and nanotubes consisting of bilayer membranes, which underwent a gel-to-liquid crystalline thermal phase transition. Vesicles formed at temperatures above the thermal phase transition temperatures (T g-l ) could solubilize aggregates of denatured proteins by trapping them in the fluid bilayer membranes. Cooling to temperatures below T g-l caused a morphological transformation into nanotubes that accompanied the thermal phase transition from the fluid to the solid state. This phenomenon allowed the trapped proteins to be quickly released into the bulk solution and simultaneously facilitated the refolding of the proteins. The refolding efficiency strongly depended on the electrostatic attraction between the bilayer membranes of the nanostructures and the proteins. Because of the long shape (>400 nm) of the nanotubes, simple membrane filtration through a pore size of 200 nm led to complete separation and recovery of the refolded proteins (3-9 nm sizes).

  7. DC-DC boost-flyback converter functioning as input stage for one phase low power grid-connected inverter

    Directory of Open Access Journals (Sweden)

    Kawa Adam

    2014-09-01

    Full Text Available The paper treats about main problems of one phase DC-AC microinverters that allow single solar cell to be joined with the grid. One of the issues is to achieve high voltage gain with high efficiency in DC circuit, which is necessary for proper operation of inverter. The operating principles, results of practical implementation and investigations on boost-flyback converter, which meets mentioned demands, are presented. (high step-up DC-DC boost-flyback converter for single phase grid microinverter

  8. A Single-Phase Voltage-Controlled Grid-Connected Photovoltaic System With Power Quality Conditioner Functionality

    DEFF Research Database (Denmark)

    Kerekes, Tamas; Liserre, Marco; Mastromauro, R. A.

    2009-01-01

    Future ancillary services provided by photovoltaic (PV) systems could facilitate their penetration in power systems. Also low power PV systems can be designed to improve the power quality. This paper presents a single-phase photovoltaic system that provides grid voltage support and compensation...... of harmonic distortion at the point of common coupling (PCC) thanks to a repetitive controller. The power provided by the PV panels is controlled by a Maximum Power Point Tracking (MPPT) algorithm based on the incremental conductance method specifically modified to control the phase of the PV inverter voltage...

  9. The impact of ice particle roughness on the scattering phase matrix

    International Nuclear Information System (INIS)

    Baum, Bryan A.; Yang Ping; Hu Yongxiang; Feng Qian

    2010-01-01

    The goal of this study is to explore the influence of ice particle habit (or shape) and surface roughness on the scattering phase matrix. As an example, reported here are the results for two wavelengths: 0.67 and 1.61 μm. For this effort, a database of single-scattering properties has been computed for a set of habits including hexagonal plates, hollow and solid columns, hollow and solid 3D bullet rosettes, droxtals, aggregates of solid columns, and aggregates of plates. The database provides properties for each of the habits at 101 wavelengths between 0.45 and 2.24 μm for smooth, moderately roughened, and severely roughened particles. At each wavelength, the scattering properties are provided at 233 discrete particle diameters ranging from 2 to 10,000 μm. A single particle size distribution from a very cold ice cloud sampled during the CRYSTAL-FACE field campaign (T cld =-76 o C) is used to illustrate the influence of habit and roughness on the phase matrix. In all, four different habit mixtures are evaluated. The nonzero elements of the phase matrix are shown to be quite sensitive to the assumed habit, particularly in the case of -P 12 /P 11 that is associated with the degree of linear polarization of scattered radiation. Surface roughness is shown to smooth out maxima in the scattering phase function and in the other elements of the phase matrix, consistent with other studies. To compare with the theoretical simulations of the phase matrix for smooth and roughened particles, a full year of cloud-aerosol lidar with orthogonal polarization (CALIOP) data from 2008 is analyzed to provide global statistics on the values of P 11 and P 22 /P 11 in the backscattering direction. In a comparison of two of the habit mixtures (one used for MODIS Collection 5 and another that incorporates new habits including hollow bullet rosettes and aggregates of plates) with the CALIOP data, the values for P 11 are higher regardless of the degree of particle surface roughness, and the

  10. Codanin-1, mutated in the anaemic disease CDAI, regulates Asf1 function in S-phase histone supply

    DEFF Research Database (Denmark)

    Ask, Katrine; Jasencakova, Zusana; Menard, Patrice

    2012-01-01

    Codanin-1 as a novel interaction partner of Asf1 regulating S-phase histone supply. Mutations in Codanin-1 can cause congenital dyserythropoietic anaemia type I (CDAI), characterized by chromatin abnormalities in bone marrow erythroblasts. Codanin-1 is part of a cytosolic Asf1-H3.1-H4-Importin-4 complex...

  11. Feynman formulae and phase space Feynman path integrals for tau-quantization of some Lévy-Khintchine type Hamilton functions

    International Nuclear Information System (INIS)

    Butko, Yana A.; Grothaus, Martin; Smolyanov, Oleg G.

    2016-01-01

    Evolution semigroups generated by pseudo-differential operators are considered. These operators are obtained by different (parameterized by a number τ) procedures of quantization from a certain class of functions (or symbols) defined on the phase space. This class contains Hamilton functions of particles with variable mass in magnetic and potential fields and more general symbols given by the Lévy-Khintchine formula. The considered semigroups are represented as limits of n-fold iterated integrals when n tends to infinity. Such representations are called Feynman formulae. Some of these representations are constructed with the help of another pseudo-differential operator, obtained by the same procedure of quantization; such representations are called Hamiltonian Feynman formulae. Some representations are based on integral operators with elementary kernels; these are called Lagrangian Feynman formulae. Langrangian Feynman formulae provide approximations of evolution semigroups, suitable for direct computations and numerical modeling of the corresponding dynamics. Hamiltonian Feynman formulae allow to represent the considered semigroups by means of Feynman path integrals. In the article, a family of phase space Feynman pseudomeasures corresponding to different procedures of quantization is introduced. The considered evolution semigroups are represented as phase space Feynman path integrals with respect to these Feynman pseudomeasures, i.e., different quantizations correspond to Feynman path integrals with the same integrand but with respect to different pseudomeasures. This answers Berezin’s problem of distinguishing a procedure of quantization on the language of Feynman path integrals. Moreover, the obtained Lagrangian Feynman formulae allow also to calculate these phase space Feynman path integrals and to connect them with some functional integrals with respect to probability measures

  12. An experimental study of the latent functionally thermal fluid with micro-encapsulated phase change material particles flowing in microchannels

    International Nuclear Information System (INIS)

    Wang, Yan; Chen, Zhenqian; Ling, Xiang

    2016-01-01

    Graphical abstract: Fig. 1. Relationship between Nu and Re for MEPCM slurry with various particle volume fractions. The interrupt of the well dispersed particles would destroy the thermal boundary layer and reduces its thickness, resulting in large Nusselt number for the suspension with 2% volume fraction of MEPCM. Large amount of heat could be absorbed and transferred rapidly during MEPCM melting process, which would result in remarkable increase of Nusselt number. The heat transfer performance of latent thermal fluid would be enhanced as 1.34 times of that of pure water. With smaller particle volume fraction (1% in this context), phase change occurs at lower temperature and more intensive heat flux is required for higher concentration suspension to induce the phase change occurrence, which is useful for application of the thermal management design. - Highlights: • The experiments of latent fluid flowing in parallel microchannels were conducted. • The performance of water with well dispersed micro-encapsulated phase change material particles was examined. • The Nusselt number of MEPCM slurry could achieve 1.36 times as that of pure water. - Abstract: Phase change material holds a good promise as a media of thermal energy storage and intensive heat flux removal. In this context, experiments were conducted to investigate the hydrodynamic and thermodynamic properties of a latent thermal fluid, which consisted of water and well dispersed micro-encapsulated phase change material (MEPCM) particles, flowing in parallel microchannels. It is suggested that MEPCM particles loading induces much higher pressure drop, which is very sensitive to temperature. Compared against water, the heat transfer performance of MEPCM slurry performs much better owing to particles aggregation, collision and micro-convective around the particles. Besides these, latent heat absorbed during phase change process makes the key contribution. It is found that with melting occurrence, Nusselt

  13. Phase space quantization and loop quantum cosmology: a Wigner function for the Bohr-compactified real line

    Energy Technology Data Exchange (ETDEWEB)

    Fewster, Christopher J [Department of Mathematics, University of York, Heslington, York YO10 5DD (United Kingdom); Sahlmann, Hanno [Spinoza Institute, Universiteit Utrecht (Netherlands)

    2008-11-21

    We give a definition for the Wigner function for quantum mechanics on the Bohr compactification of the real line and prove a number of simple consequences of this definition. We then discuss how this formalism can be applied to loop quantum cosmology. As an example, we use the Wigner function to give a new quantization of an important building block of the Hamiltonian constraint.

  14. Coral-macroalgal phase shifts or reef resilience: links with diversity and functional roles of herbivorous fishes on the Great Barrier Reef

    Science.gov (United States)

    Cheal, A. J.; MacNeil, M. Aaron; Cripps, E.; Emslie, M. J.; Jonker, M.; Schaffelke, B.; Sweatman, H.

    2010-12-01

    Changes from coral to macroalgal dominance following disturbances to corals symbolize the global degradation of coral reefs. The development of effective conservation measures depends on understanding the causes of such phase shifts. The prevailing view that coral-macroalgal phase shifts commonly occur due to insufficient grazing by fishes is based on correlation with overfishing and inferences from models and small-scale experiments rather than on long-term quantitative field studies of fish communities at affected and resilient sites. Consequently, the specific characteristics of herbivorous fish communities that most promote reef resilience under natural conditions are not known, though this information is critical for identifying vulnerable ecosystems. In this study, 11 years of field surveys recorded the development of the most persistent coral-macroalgal phase shift (>7 years) yet observed on Australia’s Great Barrier Reef (GBR). This shift followed extensive coral mortality caused by thermal stress (coral bleaching) and damaging storms. Comparisons with two similar reefs that suffered similar disturbances but recovered relatively rapidly demonstrated that the phase shift occurred despite high abundances of one herbivore functional group (scraping/excavating parrotfishes: Labridae). However, the shift was strongly associated with low fish herbivore diversity and low abundances of algal browsers (predominantly Siganidae) and grazers/detritivores (Acanthuridae), suggesting that one or more of these factors underpin reef resilience and so deserve particular protection. Herbivorous fishes are not harvested on the GBR, and the phase shift was not enhanced by unusually high nutrient levels. This shows that unexploited populations of herbivorous fishes cannot ensure reef resilience even under benign conditions and suggests that reefs could lose resilience under relatively low fishing pressure. Predictions of more severe and widespread coral mortality due to global

  15. Protein sorting by lipid phase-like domains supports emergent signaling function in B lymphocyte plasma membranes.

    Science.gov (United States)

    Stone, Matthew B; Shelby, Sarah A; Núñez, Marcos F; Wisser, Kathleen; Veatch, Sarah L

    2017-02-01

    Diverse cellular signaling events, including B cell receptor (BCR) activation, are hypothesized to be facilitated by domains enriched in specific plasma membrane lipids and proteins that resemble liquid-ordered phase-separated domains in model membranes. This concept remains controversial and lacks direct experimental support in intact cells. Here, we visualize ordered and disordered domains in mouse B lymphoma cell membranes using super-resolution fluorescence localization microscopy, demonstrate that clustered BCR resides within ordered phase-like domains capable of sorting key regulators of BCR activation, and present a minimal, predictive model where clustering receptors leads to their collective activation by stabilizing an extended ordered domain. These results provide evidence for the role of membrane domains in BCR signaling and a plausible mechanism of BCR activation via receptor clustering that could be generalized to other signaling pathways. Overall, these studies demonstrate that lipid mediated forces can bias biochemical networks in ways that broadly impact signal transduction.

  16. Catalytic Functionalities of Nano Ruthenium/gamma-Al2O3 Catalysts for the Vapour Phase Hydrogenolysis of Glycerol.

    Science.gov (United States)

    Kumar, Vanama Pavan; Priya, Samudrala Shanthi; Harikrishna, Yengaidas; Kumar, Ashish; Chary, Komandur V R

    2016-02-01

    A series of Ruthenium catalysts with different Ru contents supported on gamma-alumina were prepared by deposition-precipitation method. The catalysts were characterized by X-ray diffraction (XRD), trans- mission electron microscopy (TEM), temperature programmed reduction (TPR), CO-chemisorption, surface area and pore-size distribution (PSD) measurements. The catalytic activities were evaluated for the vapour phase hydrogenolysis of glycerol to propanediols. The pore size distribution (PSD) results suggest that Ru loadings considerably affect the pore volume, pore diameter and surface area. The particle size measured from CO-chemisorption and TEM analysis are well correlated to the activity results during the hydrogenolysis reaction. The catalytic properties of Ru/gamma-Al2O3 catalysts were evaluated for the first time over vapour phase hydrogenolysis of glycerol to propanediols.

  17. Effect of recombinant alpha interferon on NK and ADCC function in lung cancer patients: results from a phase II trial

    DEFF Research Database (Denmark)

    Hokland, P; Hokland, M; Olesen, B K

    1985-01-01

    During a phase II trial of recombinant IFN-alpha given in doses of 50 X 10(6) units/m2 three times per week to lung cancer patients, 13 patients were evaluated longitudinally in NK and ADCC assays and in immunofluorescence tests enumerating the number of cells reactive with the new N901 NK....... These data are discussed in relation to other clinical trials using leukocyte or recombinant IFN-alpha. Udgivelsesdato: 1984 Fall...

  18. Acute-phase predictors of 6-month functional outcome in Italian stroke patients eligible for In-Hospital Rehabilitation.

    Science.gov (United States)

    Franceschini, Marco; Fugazzaro, Stefania; Agosti, Maurizio; Sola, Carlotta; Di Carlo, Antonio; Cecconi, Lorenzo; Ferro, Salvatore

    2018-01-23

    to assess early post-stroke prognostic factors in patients admitted for post-acute phase rehabilitation. a one-year multicenter prospective project was conducted in four Italian regions on 352 patients who were hospitalized after a first stroke and were eligible for post-acute rehabilitation. Clinical data were collected in the Stroke or Acute Care Units (acute phase), then in Rehabilitation Units (post-acute phase) and, subsequently, after a 6-month post-stroke period (follow-up). Clinical outcome measures were represented using the Barthel Index (BI) and the modified Rankin Scale (mRS). Univariate and multivariate analyses were performed to identify the most important prognostic index. mRS score, minor neurologic impairment and early out-of-bed mobilization (within 2 days after the stroke) proved to be important factors related to a better recovery according to BI (power of prediction = 37%). Similarly, age, pre-morbid mRS score and early out-of-bed mobilization were seen to be significant factors in achieving better overall participation and activity according to the mRS (power of prediction = 48%). BI at admission and certain comorbidities were also significant prognostic factors correlated with a better outcome. according to the BI and mRS, early mobilization is an early predictor of favorable outcome.

  19. Nephrotic range proteinuria as a strong risk factor for rapid renal function decline during pre-dialysis phase in type 2 diabetic patients with severely impaired renal function.

    Science.gov (United States)

    Kitai, Yuichiro; Doi, Yohei; Osaki, Keisuke; Sugioka, Sayaka; Koshikawa, Masao; Sugawara, Akira

    2015-12-01

    Proteinuria is an established risk factor for progression of renal disease, including diabetic nephropathy. The predictive power of proteinuria, especially nephrotic range proteinuria, for progressive renal deterioration has been well demonstrated in diabetic patients with normal to relatively preserved renal function. However, little is known about the relationship between severity of proteinuria and renal outcome in pre-dialysis diabetic patients with severely impaired renal function. 125 incident dialysis patients with type 2 diabetes were identified. This study was aimed at retrospectively evaluating the impact of nephrotic range proteinuria (urinary protein-creatinine ratio above 3.5 g/gCr) on renal function decline during the 3 months just prior to dialysis initiation. In total, 103 patients (82.4 %) had nephrotic range proteinuria. The median rate of decline in estimated glomerular filtration rate (eGFR) in this study population was 0.98 (interquartile range 0.51-1.46) ml/min/1.73 m(2) per month. Compared to patients without nephrotic range proteinuria, patients with nephrotic range proteinuria showed significantly faster renal function decline (0.46 [0.24-1.25] versus 1.07 [0.64-1.54] ml/min/1.73 m(2) per month; p = 0.007). After adjusting for gender, age, systolic blood pressure, serum albumin, calcium-phosphorus product, hemoglobin A1c, and use of an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker, patients with nephrotic range proteinuria showed a 3.89-fold (95 % CI 1.08-14.5) increased risk for rapid renal function decline defined as a decline in eGFR ≥0.5 ml/min/1.73 m(2) per month. Nephrotic range proteinuria is the predominant renal risk factor in type 2 diabetic patients with severely impaired renal function receiving pre-dialysis care.

  20. Use of Nuclear Magnetic Resonance as an Experimental Probe in Multiphase Systems: Determination of the Instrument Weight Function for Measurements of Liquid-Phase Volume Fractions

    Science.gov (United States)

    Maneval, J. E.; McCarthy, M. J.; Whitaker, S.

    1990-11-01

    The relativist approach (Baveye and Sposito (1984)) to the interpretation of measurements in multiphase systems was proposed in order to incorporate the details of measurements into theoretical analyses of multiphase transport processes. To help establish the utility of this approach, the weight functions for actual experimental probes must be determined. In this paper we analyze the measurement of liquid-phase porosity in a model system by nuclear magnetic resonance imaging. We show how both nuclear magnetic resonance (NMR) physics and experimental technique combine to determine the weight function for the spin-warp spin-echo sequence. The analysis shows clearly what aspects of the weight function are determined by the experimental method and what aspects are determined by the system being studied. The results will help establish the utility of the relativist approach as well as improve understanding NMR measurements in multiphase systems.

  1. Electronic structure and physical properties of the spinel-type phase of BeP2N4 from all-electron density functional calculations

    International Nuclear Information System (INIS)

    Ching, W. Y.; Aryal, Sitram; Rulis, Paul; Schnick, Wolfgang

    2011-01-01

    Using density-functional-theory-based ab initio methods, the electronic structure and physical properties of the newly synthesized nitride BeP 2 N 4 with a phenakite-type structure and the predicted high-pressure spinel phase of BeP 2 N 4 are studied in detail. It is shown that both polymorphs are wide band-gap semiconductors with relatively small electron effective masses at the conduction-band minima. The spinel-type phase is more covalently bonded due to the increased number of P-N bonds for P at the octahedral sites. Calculations of mechanical properties indicate that the spinel-type polymorph is a promising superhard material with notably large bulk, shear, and Young's moduli. Also calculated are the Be K, P K, P L 3 , and N K edges of the electron energy-loss near-edge structure for both phases. They show marked differences because of the different local environments of the atoms in the two crystalline polymorphs. These differences will be very useful for the experimental identification of the products of high-pressure syntheses targeting the predicted spinel-type phase of BeP 2 N 4 .

  2. Prefrontal responses to digit span memory phases in patients with post-traumatic stress disorder (PTSD): a functional near infrared spectroscopy study.

    Science.gov (United States)

    Tian, Fenghua; Yennu, Amarnath; Smith-Osborne, Alexa; Gonzalez-Lima, F; North, Carol S; Liu, Hanli

    2014-01-01

    Neuroimaging studies of post-traumatic stress disorder (PTSD)-related memory impairments have consistently implicated abnormal activities in the frontal and parietal lobes. However, most studies have used block designs and could not dissociate the multiple phases of working memory. In this study, the involvement of the prefrontal cortex in working memory phases was assessed among veterans with PTSD and age-/gender-matched healthy controls. Multichannel functional near infrared spectroscopy (fNIRS) was utilized to measure prefrontal cortex hemodynamic activations during memory of neutral (i.e., not trauma-related) forward and backward digit span tasks. An event-related experimental design was utilized to dissociate the different phases (i.e., encoding, maintenance and retrieval) of working memory. The healthy controls showed robust hemodynamic activations during the encoding and retrieval processes. In contrast, the veterans with PTSD were found to have activations during the encoding process, but followed by distinct deactivations during the retrieval process. The PTSD participants, but not the controls, appeared to suppress prefrontal activity during memory retrieval. This deactivation was more pronounced in the right dorsolateral prefrontal cortex during the retrieval phase. These deactivations in PTSD patients might implicate an active inhibition of dorsolateral prefrontal neural activity during retrieval of working memory.

  3. Sustained activation of GABAA receptors in the suprachiasmatic nucleus mediates light-induced phase delays of the circadian clock: a novel function of ionotropic receptors.

    Science.gov (United States)

    Hummer, Daniel L; Ehlen, J Christopher; Larkin, Tony E; McNeill, John K; Pamplin, John R; Walker, Colton A; Walker, Phillip V; Dhanraj, Daryl R; Albers, H Elliott

    2015-07-01

    The suprachiasmatic nucleus (SCN) contains a circadian clock that generates endogenous rhythmicity and entrains that rhythmicity with the day-night cycle. The neurochemical events that transduce photic input within the SCN and mediate entrainment by resetting the molecular clock have yet to be defined. Because GABA is contained in nearly all SCN neurons we tested the hypothesis that GABA serves as this signal in studies employing Syrian hamsters (Mesocricetus auratus). Activation of GABAA receptors was found to be necessary and sufficient for light to induce phase delays of the clock. Remarkably, the sustained activation of GABAA receptors for more than three consecutive hours was necessary to phase-delay the clock. The duration of GABAA receptor activation required to induce phase delays would not have been predicted by either the prevalent theory of circadian entrainment or by expectations regarding the duration of ionotropic receptor activation necessary to produce functional responses. Taken together, these data identify a novel neurochemical mechanism essential for phase-delaying the 'master' circadian clock within the SCN as well as identifying an unprecedented action of an amino acid neurotransmitter involving the sustained activation of ionotropic receptors. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  4. Prefrontal responses to digit span memory phases in patients with post-traumatic stress disorder (PTSD: A functional near infrared spectroscopy study

    Directory of Open Access Journals (Sweden)

    Fenghua Tian

    2014-01-01

    Full Text Available Neuroimaging studies of post-traumatic stress disorder (PTSD-related memory impairments have consistently implicated abnormal activities in the frontal and parietal lobes. However, most studies have used block designs and could not dissociate the multiple phases of working memory. In this study, the involvement of the prefrontal cortex in working memory phases was assessed among veterans with PTSD and age-/gender-matched healthy controls. Multichannel functional near infrared spectroscopy (fNIRS was utilized to measure prefrontal cortex hemodynamic activations during memory of neutral (i.e., not trauma-related forward and backward digit span tasks. An event-related experimental design was utilized to dissociate the different phases (i.e., encoding, maintenance and retrieval of working memory. The healthy controls showed robust hemodynamic activations during the encoding and retrieval processes. In contrast, the veterans with PTSD were found to have activations during the encoding process, but followed by distinct deactivations during the retrieval process. The PTSD participants, but not the controls, appeared to suppress prefrontal activity during memory retrieval. This deactivation was more pronounced in the right dorsolateral prefrontal cortex during the retrieval phase. These deactivations in PTSD patients might implicate an active inhibition of dorsolateral prefrontal neural activity during retrieval of working memory.

  5. Extension of Toth function from gas-solid to liquid-solid equilibria and application to reversed-phase liquid chromatography systems

    Energy Technology Data Exchange (ETDEWEB)

    Gritti, Fabrice [University of Tennessee, Knoxville (UTK); Guiochon, Georges A [ORNL

    2006-03-01

    The extension of the {Psi} function developed by Toth from equilibria taking place at gas-solid interfaces to those taking place at liquid-solid interfaces was investigated. The results were applied to conventional liquid-solid systems used in reversed-phase liquid chromatography (RPLC). The adsorbents in these systems are made of porous silica having a hydrophobic solid surface obtained by chemically bonding C{sub 18} alkyl chains to a porous silica gel then endcapping the surface with trimethylsilyl groups. The liquid is an aqueous solution of an organic solvent, most often methanol or acetonitrile. The probe compound used here is phenol. Adsorption data of phenol were measured using the dynamic frontal analysis (FA) method. The excess adsorption of the organic solvent was measured using the minor disturbance (MD) method. Activity coefficients in the bulk were estimated through the UNIFAC group contributions. The results show that the {Psi} function predicts 90% of the total free energy of immersion, {Delta}F, of the solid when the concentration of phenol is moderate (typically less than 10 g/L). At higher concentrations, the nonideal behavior of the bulk liquid phase becomes significant and it may contribute up to about 30% of {Delta}F. The high concentration of adsorbed molecules of phenol at the interface decreases the interfacial tension, {sigma}, by about 18 mN/m, independently of the structure of the adsorbed phase and of the nature of the organic solvent.

  6. Extension of Tóth Psi function from gas-solid to liquid-solid equilibria and application to reversed-phase liquid chromatography systems.

    Science.gov (United States)

    Gritti, Fabrice; Guiochon, Georges

    2006-07-01

    The extension of the Psi function developed by Tóth from equilibria taking place at gas-solid interfaces to those taking place at liquid-solid interfaces was investigated. The results were applied to conventional liquid-solid systems used in reversed-phase liquid chromatography (RPLC). The adsorbents in these systems are made of porous silica having a hydrophobic solid surface obtained by chemically bonding C(18) alkyl chains to a porous silica gel then endcapping the surface with trimethylsilyl groups. The liquid is an aqueous solution of an organic solvent, most often methanol or acetonitrile. The probe compound used here is phenol. Adsorption data of phenol were measured using the dynamic frontal analysis (FA) method. The excess adsorption of the organic solvent was measured using the minor disturbance (MD) method. Activity coefficients in the bulk were estimated through the UNIFAC group contributions. The results show that the Psi function predicts 90% of the total free energy of immersion, DeltaF, of the solid when the concentration of phenol is moderate (typically less than 10 g/L). At higher concentrations, the nonideal behavior of the bulk liquid phase becomes significant and it may contribute up to about 30% of DeltaF. The high concentration of adsorbed molecules of phenol at the interface decreases the interfacial tension, sigma, by about 18 mN/m, independently of the structure of the adsorbed phase and of the nature of the organic solvent.

  7. Gender-specific cerebral activation during cognitive tasks using functional MRI: comparison of women in mid-luteal phase and men

    International Nuclear Information System (INIS)

    Gizewski, Elke R.; Wanke, Isabel; Forsting, Michael; Krause, Eva; Senf, Wolfgang

    2006-01-01

    Previous studies of gender-specific differences in functional imaging during spatial and language tasks have been inconclusive. Furthermore, among women, such differences may occur during mid-luteal phase compared to the rest of the menstrual cycle. In order to examine further gender differences, functional MRI was performed in 12 male volunteers and 12 female volunteers (in the mid-luteal phase) during mental rotation and verb-generation tests. Two-sample t-tests with uncorrected P values of <0.001 for the specific regions of interest (ROIs) revealed cerebral activation differences in both stimuli. During mental rotation tests, higher levels of activation were noted in the right medial frontal, precentral, and bilateral inferior parietal cortex, while in women this occurred in the right inferior and medial temporal, right superior frontal cortex, and left fusiform gyrus. During verb-generation tests, higher levels of activation in men was found in the left medial temporal and precentral cortex. Our results indicate that differences in cerebral activity during cognitive tasks can be shown between men and women in the mid-luteal phase. Gender differences while performing a mental rotation task were more prominent than during a verb-generation task. (orig.)

  8. Pre-fracture nutritional status is predictive of functional status at discharge during the acute phase with hip fracture patients: A multicenter prospective cohort study.

    Science.gov (United States)

    Inoue, Tatsuro; Misu, Syogo; Tanaka, Toshiaki; Sakamoto, Hiroki; Iwata, Kentaro; Chuman, Yuki; Ono, Rei

    2017-10-01

    Malnutrition is common in patients with hip fractures, and elderly patients with hip fractures lose functional independence and often fail to recover previous functional status. The aim of this study was to determine whether pre-fracture nutritional status predicts functional status of patients with hip fracture at discharge from acute hospitals. In the present multicenter prospective cohort study, pre-fracture nutritional status was assessed using the Mini Nutritional Assessment Short-Form (MNA-SF). At discharge from acute hospitals, functional status was evaluated using a functional independent measurement instrument (FIM). Subsequently, multiple regression analyses were performed using FIM as the dependent variable and MNA-SF as the independent variable. Among the 204 patients analyzed in the present study, the mean length of hospital stay was 26.2 ± 12.6 days, and according to MNA-SF assessments, 51 (25.0%) patients were malnourished, 98 (48.0%) were at risk of malnutrition, and 55 (27.0%) were well-nourished before fracture. At discharge, FIM scores were higher in patients who were well-nourished than in those who were malnourished or were at risk of malnutrition (p nutritional status was a significant independent predictor for functional status at discharge during the acute phase, warranting early assessment of nutritional status and early intervention for successful postoperative rehabilitation. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  9. A functional form-stable phase change composite with high efficiency electro-to-thermal energy conversion

    International Nuclear Information System (INIS)

    Wu, Wenhao; Huang, Xinyu; Li, Kai; Yao, Ruimin; Chen, Renjie; Zou, Ruqiang

    2017-01-01

    Graphical abstract: The thermal conductivity of PU was enhanced to 43 times of the pristine value by encapsulation in a PGF, PU@PGF can be used for highly efficient electro-to-heat energy conversion and storage with the highest energy storage efficiency up to 85%. - Highlights: • The composite exhibits an in-situ solid-solid phase change behavior. • The enthalpy of polyurethane is enhanced within the matrix. • The thermal conductivity of the composite is 43 times as much as that of the polyurethane. • Supercooling of polyurethane is greatly reduced. • The composite is applied to cold protection as a wear layer. - Abstract: A novel solid-to-solid phase change composite brick was prepared by combination of polyurethane (PU) and pitch-based graphite foam (PGF). The carbonaceous support, which can be used for mass production, not only greatly improves the thermal conductivity but promote electro-to-heat conversion efficiency of organic phase change materials (PCMs). Our composite retained the enthalpy of PCM and exhibited a greatly reduced supercooling temperature. The novel composite was investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscope (SEM). The enthalpy of polyurethane has increased about 8.6% after infiltrating into graphite foam. The composite was very stable during thermal cycle test, and the electro-to-heat conversion efficiency achieves to 85% at lower voltages (1.5–1.8 V), which can vastly reduce energy consumption. The as-prepared composite was used in a wear layer to test its performance comparing with normal fabric.

  10. A novel function of CRL4(Cdt2): regulation of the subunit structure of DNA polymerase δ in response to DNA damage and during the S phase.

    Science.gov (United States)

    Zhang, Sufang; Zhao, Hong; Darzynkiewicz, Zbiegniew; Zhou, Pengbo; Zhang, Zhongtao; Lee, Ernest Y C; Lee, Marietta Y W T

    2013-10-11

    DNA polymerase δ (Pol δ4) is a heterotetrameric enzyme, whose p12 subunit is degraded in response to DNA damage, leaving behind a trimer (Pol δ3) with altered enzymatic characteristics that participate in gap filling during DNA repair. We demonstrate that CRL4(Cdt2), a key regulator of cell cycle progression that targets replication licensing factors, also targets the p12 subunit of Pol δ4 in response to DNA damage and on entry into S phase. Evidence for the involvement of CRL4(Cdt2) included demonstration that p12 possesses a proliferating cell nuclear antigen-interacting protein-degron (PIP-degron) and that knockdown of the components of the CRL4(Cdt2) complex inhibited the degradation of p12 in response to DNA damage. Analysis of p12 levels in synchronized cell populations showed that p12 is partially degraded in S phase and that this is affected by knockdowns of CUL4A or CUL4B. Laser scanning cytometry of overexpressed wild type p12 and a mutant resistant to degradation showed that the reduction in p12 levels during S phase was prevented by mutation of p12. Thus, CRL4(Cdt2) also regulates the subunit composition of Pol δ during the cell cycle. These studies reveal a novel function of CRL4(Cdt2), i.e. the direct regulation of DNA polymerase δ, adding to its known functions in the regulation of the licensing of replication origins and expanding the scope of its overall control of DNA replication. The formation of Pol δ3 in S phase as a normal aspect of cell cycle progression leads to the novel implications that it is involved in DNA replication as well as DNA repair.

  11. Novel phase-based noise reduction strategy for quantification of left ventricular function and mass assessment by cardiac CT: Comparison with cardiac magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Wai, Bryan, E-mail: bwai@partners.org [Cardiac MR PET CT Program, Division of Cardiology and Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Thai, Wai-ee [Cardiac MR PET CT Program, Division of Cardiology and Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States); Brown, Heather [Qi Imaging, Redwood City, California (United States); Truong, Quynh A. [Cardiac MR PET CT Program, Division of Cardiology and Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts (United States)

    2013-08-15

    Background: Tube current modulation in retrospective ECG gated cardiac computed tomography (CT) results in increased image noise and may reduce the accuracy of left ventricular (LV) ejection fraction (EF) and mass assessment. Objective: To examine the effects of a novel CT phase-based noise reduction (NR) algorithm on LV EF and mass quantification as compared to cardiac magnetic resonance (CMR). Methods: In 40 subjects, we compared the LV EF and mass between CT and CMR. In a subset of 24 subjects with tube current modulated CT, the effect of phase-based noise reduction strategies on contrast-to-noise ratio (CNR) and the assessment of LV EF and mass was compared to CMR. Results: There was excellent correlation between CT and CMR for EF (r = 0.94) and mass (r = 0.97). As compared to CMR, the limits of agreement improved with increasing strength of NR strategy. There was a systematic underestimation of LV mass by CT compared to CMR with no NR (−10.3 ± 10.1 g) and low NR (−10.3 ± 12.5 g), but was attenuated with high NR (−0.5 ± 8.3 g). Studies without NR had lower CNR compared to low and high NR at both the ES phase and ED phase (all p < 0.01). Conclusions: A high NR strategy on tube current modulated functional cardiac CT improves correlation of EF compared to CMR and reduces variability of EF and mass evaluation by increasing the CNR. In an effort to reduce radiation dose with tube current modulation, this strategy provides better image quality when LV function and mass quantification is needed.

  12. Novel phase-based noise reduction strategy for quantification of left ventricular function and mass assessment by cardiac CT: Comparison with cardiac magnetic resonance

    International Nuclear Information System (INIS)

    Wai, Bryan; Thai, Wai-ee; Brown, Heather; Truong, Quynh A.

    2013-01-01

    Background: Tube current modulation in retrospective ECG gated cardiac computed tomography (CT) results in increased image noise and may reduce the accuracy of left ventricular (LV) ejection fraction (EF) and mass assessment. Objective: To examine the effects of a novel CT phase-based noise reduction (NR) algorithm on LV EF and mass quantification as compared to cardiac magnetic resonance (CMR). Methods: In 40 subjects, we compared the LV EF and mass between CT and CMR. In a subset of 24 subjects with tube current modulated CT, the effect of phase-based noise reduction strategies on contrast-to-noise ratio (CNR) and the assessment of LV EF and mass was compared to CMR. Results: There was excellent correlation between CT and CMR for EF (r = 0.94) and mass (r = 0.97). As compared to CMR, the limits of agreement improved with increasing strength of NR strategy. There was a systematic underestimation of LV mass by CT compared to CMR with no NR (−10.3 ± 10.1 g) and low NR (−10.3 ± 12.5 g), but was attenuated with high NR (−0.5 ± 8.3 g). Studies without NR had lower CNR compared to low and high NR at both the ES phase and ED phase (all p < 0.01). Conclusions: A high NR strategy on tube current modulated functional cardiac CT improves correlation of EF compared to CMR and reduces variability of EF and mass evaluation by increasing the CNR. In an effort to reduce radiation dose with tube current modulation, this strategy provides better image quality when LV function and mass quantification is needed

  13. Assessing the utility of phase-space-localized basis functions: Exploiting direct product structure and a new basis function selection procedure.

    Science.gov (United States)

    Brown, James; Carrington, Tucker

    2016-06-28

    In this paper we show that it is possible to use an iterative eigensolver in conjunction with Halverson and Poirier's symmetrized Gaussian (SG) basis [T. Halverson and B. Poirier, J. Chem. Phys. 137, 224101 (2012)] to compute accurate vibrational energy levels of molecules with as many as five atoms. This is done, without storing and manipulating large matrices, by solving a regular eigenvalue problem that makes it possible to exploit direct-product structure. These ideas are combined with a new procedure for selecting which basis functions to use. The SG basis we work with is orders of magnitude smaller than the basis made by using a classical energy criterion. We find significant convergence errors in previous calculations with SG bases. For sum-of-product Hamiltonians, SG bases large enough to compute accurate levels are orders of magnitude larger than even simple pruned bases composed of products of harmonic oscillator functions.

  14. Unique Reversible Crystal-to-Crystal Phase Transition – Structural and Functional Properties of Fused Ladder Thienoarenes

    KAUST Repository

    Abe, Yuichiro

    2017-08-15

    Donor-acceptor type molecules based on fused ladder thienoarenes, indacenodithiophene (IDT) and dithienocyclopenta-thienothiophene (DTCTT), coupled with benzothiadiazole, are prepared and their solid-state structures are investigated. They display a rich variety of solid phases ranging from amorphous glass states to crystalline states, upon changes in the central aromatic core and side group structures. Most notably, the DTCTT-based derivatives showed reversible crystal-to-crystal phase transitions in heating and cooling cycles. Unlike what has been seen in π−conjugated molecules variable temperature XRD revealed that structural change occurs continuously during the transition. A columnar self-assembled structure with slip-stacked π−π interaction is proposed to be involved in the solid-state. This research provides the evidence of unique structural behavior of the DTCTT-based molecules through the detailed structural analysis. This unique structural transition paves the way for these materials to have self-healing of crystal defects, leading to improved optoelectronic properties.

  15. Simultaneous Determination of 10 Adulterants in Antihypertensive Functional Foods Using Multi-Walled Carbon Nanotubes-Dispersive Solid-Phase Extraction Coupled with High Performance Liquid Chromatography.

    Science.gov (United States)

    Zeng, Li; Li, Yongxin; Wu, Xin; Zhang, Jing; Xie, Juan; Sun, Chengjun

    2015-10-01

    Consumption of functional foods based on extracts from selected herbs to alleviate hypertension is an increasingly common practice in China. Adulteration of these foods with pharmaceuticals can significantly impact a consumer's health. To control the quality of the functional foods effectively, a method for the simultaneous determination of 10 common adulterants including chlortalidone, hydrochlorothiazide, indapamide, metoprolol, nifedipine, nimodipine, nitrendipine, reserpine, triamterene and valsartan in antihypertensive functional foods was developed. The target chemicals in samples were ultrasonically extracted with acetonitrile, and then cleaned-up with multi-walled carbon natotubes-dispersive solid-phase extraction. Finally, the analytes were separated with a C18 column using binary mobile phases consisting of acetonitrile and 0.03 mol/L KH2PO4 solutions (pH 3.0). The flow rate of the mobile phase was 0.80 mL/min, and the column temperature was 35°C. The detection wavelength was set at 220 nm. The limits of detection and quantification of the method ranged from 0.014 to 0.053 and 0.047 to 0.178 μg/mL, respectively. The recoveries of the method were in the range of 80.1-98.1% with relative standard deviations <9.53%. The method was successfully applied to the determination of the target chemicals in real samples and simulated samples, and respirine was detected in one tonic wine sample with a concentration of 56.8 ± 1.2 mg/L. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  16. Effect of particle nonsphericity on bidirectional reflectance of cirrus clouds

    Energy Technology Data Exchange (ETDEWEB)

    Mishchenko, M.I.; Rossow, W.B.; Macke, A.; Lacis, A.A. [Goddard Institute for Space Studies, New York, NY (United States)

    1996-04-01

    This paper describes the use of the fractal ice particle method to study the differences in bidirectional reflectance caused by the differences in the single scattering phase functions of spherical water droplets and nonspherical ice crystals.

  17. Airborne Remote Sounding of Cirrus Cloud Parameters Using ARES Channel Data

    National Research Council Canada - National Science Library

    Ou, S

    1997-01-01

    Results of the phase function, single scattering albedos, and extinction coefficients for three representative cirrus cloud ice crystal size distributions are presented for the Airborne Remote Earth Sensing (ARES) System...

  18. Surface EEG Shows that Functional Segregation via Phase Coupling Contributes to the Neural Substrate of Mental Calculations

    Science.gov (United States)

    Dimitriadis, Stavros I.; Kanatsouli, Kassiani; Laskaris, Nikolaos A.; Tsirka, Vasso; Vourkas, Michael; Micheloyannis, Sifis

    2012-01-01

    Multichannel EEG traces from healthy subjects are used to investigate the brain's self-organisation tendencies during two different mental arithmetic tasks. By making a comparison with a control-state in the form of a classification problem, we can detect and quantify the changes in coordinated brain activity in terms of functional connectivity.…

  19. The effect of subtalar inversion/eversion on the dynamic function of the tibialis anterior, soleus, and gastrocnemius during the stance phase of gait.

    Science.gov (United States)

    Wang, Ruoli; Gutierrez-Farewik, Elena M

    2011-05-01

    The purpose of this study was to determine how gait deviation in one plane (i.e. excessive subtalar inversion/eversion) can affect the dynamic function of the tibialis anterior, gastrocnemius, and soleus to accelerate the subtalar, ankle, knee and hip joints, as well as the body center of mass. Induced acceleration analysis was performed based on a subject-specific three-dimensional linkage model configured by stance phase gait data and driven by one unit of muscle force. Eight healthy adult subjects were examined in gait analysis. The subtalar inversion/eversion was modeled by offsetting up to 20° from the normal subtalar angle while other configurations remained unaltered. This study showed that the gastrocnemius, soleus and tibialis anterior generally functioned as their anatomical definition in normal gait, but counterintuitive function was occasionally found in the bi-articular gastrocnemius. The plantarflexors play important roles in the body support and forward progression. Excessive subtalar eversion was found to enlarge the plantarflexors and tibialis anterior's function. Induced acceleration analysis demonstrated its ability to isolate the contributions of individual muscle to a given factor, and as a means of studying effect of pathological gait on the dynamic muscle functions. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Effects of Lipid-Analog Detergent Solubilization on the Functionality and Lipidic Cubic Phase Mobility of the Torpedo californica Nicotinic Acetylcholine Receptor

    Science.gov (United States)

    Padilla-Morales, Luis F.; Morales-Pérez, Claudio L.; De La Cruz-Rivera, Pamela C.; Asmar-Rovira, Guillermo; Báez-Pagán, Carlos A.

    2011-01-01

    Over the past three decades, the Torpedo californica nicotinic acetylcholine receptor (nAChR) has been one of the most extensively studied membrane protein systems. However, the effects of detergent solubilization on nAChR stability and function are poorly understood. The use of lipid-analog detergents for nAChR solubilization has been shown to preserve receptor stability and functionality. The present study used lipid-analog detergents from phospholipid-analog and cholesterol-analog detergent families for solubilization and affinity purification of the receptor and probed nAChR ion channel function using planar lipid bilayers (PLBs) and stability using analytical size exclusion chromatography (A-SEC) in the detergent-solubilized state. We also examined receptor mobility on the lipidic cubic phase (LCP) by measuring the nAChR mobile fraction and diffusion coefficient through fluorescence recovery after photobleaching (FRAP) experiments using lipid-analog and non-lipid-analog detergents. Our results show that it is possible to isolate stable and functional nAChRs using lipid-analog detergents, with characteristic ion channel currents in PLBs and minimal aggregation as observed in A-SEC. Furthermore, fractional mobility and diffusion coefficient values observed in FRAP experiments were similar to the values observed for these parameters in the recently LCP-crystallized β2-adrenergic receptor. The overall results show that phospholipid-analog detergents with 16 carbon acyl-chains support nAChR stability, functionality and LCP mobility. PMID:21922299

  1. Reentrant behaviors in the phase diagram of spin-1 planar ferromagnets with easy-axis single-ion anisotropy via the Devlin two-time Green function framework

    Science.gov (United States)

    Mercaldo, M. T.; Rabuffo, I.; De Cesare, L.; Caramico D'Auria, A.

    2017-10-01

    The Devlin two-time Green function framework is used to investigate the role played by the easy-axis single-ion anisotropy on the phase diagram of (d > 2) -dimensional spin-1 planar ferromagnets which exhibit a magnetic-field-induced quantum phase transition (QPT). In this scheme, the exchange anisotropy terms in the equations of motion are treated at the Tyablikov decoupling level while the crystal field anisotropy contribution is handled exactly. The emerging key result is a reentrant structure of the phase diagram close to the quantum critical point for a well defined window of values of the single-ion anisotropy parameter. This experimentally interesting feature was recently recovered by employing the Anderson-Callen decoupling (ACD) which is considered to provide meaningful results only for small values of the single-ion anisotropy parameter. In this context, our findings suggest that the simplest ACD treatment offers the possibility to have, at least qualitatively, a correct physical scenario of quantum criticality close to a field-induced QPT avoiding the limiting mathematical difficulties involved in the Devlin scheme.

  2. Transfer function modeling of parallel connected two three-phase induction motor implementation using LabView platform

    DEFF Research Database (Denmark)

    Gunabalan, R.; Sanjeevikumar, P.; Blaabjerg, Frede

    2015-01-01

    This paper presents the transfer function modeling and stability analysis of two induction motors of same ratings and parameters connected in parallel. The induction motors are controlled by a single inverter and the entire drive system is modeled using transfer function in LabView. Further......, the software is used to perform the stability analysis of the parallel connected induction motor drive under unbalanced load conditions. It is very simple compared with the methods discussed so far to study the performance of the drive under unbalanced load conditions. Control design and simulation toolkits...... are used to model the drive system and to study the stability analysis. Simulation is done for various operating conditions and the stability investigation is performed for different load conditions and difference in stator and rotor resistances among the two motors....

  3. Density-functional theory computer simulations of CZTS{sub 0.25}Se{sub 0.75} alloy phase diagrams

    Energy Technology Data Exchange (ETDEWEB)

    Chagarov, E.; Sardashti, K.; Kummel, A. C. [Departments of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093 (United States); Haight, R. [IBM T. J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (United States); Mitzi, D. B. [Departments of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina 27708 (United States)

    2016-08-14

    Density-functional theory simulations of CZTS, CZTSe, and CZTS{sub 0.25}Se{sub 0.75} photovoltaic compounds have been performed to investigate the stability of the CZTS{sub 0.25}Se{sub 0.75} alloy vs. decomposition into CZTS, CZTSe, and other secondary compounds. The Gibbs energy for vibrational contributions was estimated by calculating phonon spectra and thermodynamic properties at finite temperatures. It was demonstrated that the CZTS{sub 0.25}Se{sub 0.75} alloy is stabilized not by enthalpy of formation but primarily by the mixing contributions to the Gibbs energy. The Gibbs energy gains/losses for several decomposition reactions were calculated as a function of temperature with/without intermixing and vibration contributions to the Gibbs energy. A set of phase diagrams was built in the multidimensional space of chemical potentials at 300 K and 900 K temperatures to demonstrate alloy stability and boundary compounds at various chemical conditions. It demonstrated for CZTS{sub 0.25}Se{sub 0.75} that the chemical potentials for stability differ between typical processing temperature (∼900 K) and operating temperature (300 K). This implies that as cooling progresses, the flux/concentration of S should be increased in MBE growth to maintain the CZTS{sub 0.25}Se{sub 0.75} in a thermodynamically stable state to minimize phase decomposition.

  4. Functionally deregulated AML1/RUNX1 cooperates with BCR-ABL to induce a blastic phase-like phenotype of chronic myelogenous leukemia in mice.

    Directory of Open Access Journals (Sweden)

    Kiyoko Yamamoto

    Full Text Available Patients in the chronic phase (CP of chronic myelogenous leukemia (CML have been treated successfully following the advent of ABL kinase inhibitors, but once they progress to the blast crisis (BC phase the prognosis becomes dismal. Although mechanisms underlying the progression are largely unknown, recent studies revealed the presence of alterations of key molecules for hematopoiesis, such as AML1/RUNX1. Our analysis of 13 BC cases revealed that three cases had AML1 mutations and the transcript levels of wild-type (wt. AML1 were elevated in BC compared with CP. Functional analysis of representative AML1 mutants using mouse hematopoietic cells revealed the possible contribution of some, but not all, mutants for the BC-phenotype. Specifically, K83Q and R139G, but neither R80C nor D171N mutants, conferred upon BCR-ABL-expressing cells a growth advantage over BCR-ABL-alone control cells in cytokine-free culture, and the cells thus grown killed mice upon intravenous transfer. Unexpectedly, wt.AML1 behaved similarly to K83Q and R139G mutants. In a bone marrow transplantation assay, K83Q and wt.AML1s induced the emergence of blast-like cells. The overall findings suggest the roles of altered functions of AML1 imposed by some, but not all, mutants, and the elevated expression of wt.AML1 for the disease progression of CML.

  5. Electrochemically induced C-H functionalization using bromide ion/2,2,6,6-tetramethylpiperidinyl-N-oxyl dual redox catalysts in a two-phase electrolytic system

    International Nuclear Information System (INIS)

    Li, Chao; Zeng, Cheng-Chu; Hu, Li-Ming; Yang, Feng-Lin; Yoo, Seung Joon; Little, R. Daniel

    2013-01-01

    Highlights: •Electrocatalytic C-H bond functionalization of tetrahydroisoquinolines is reported. •The transformation is mediated by a bromide ion/TEMPO dual redox catalyst system. •The transformation is conducted in a two-phase electrolytic medium. •The mechanism is proposed to proceed via a sequence of oxidation and addition reactions involving water as a nucleophile. •The procedure features wide substrate scope, the use of mild reaction conditions. -- Abstract: The electrochemical oxidative functionalization of benzylic C-H bonds, mediated by a dual bromide ion/2,2,6,6-tetramethylpiperidinyl-N-oxyl (TEMPO) redox catalyst system in a two-phase electrolytic medium, has been explored using cyclic voltammetry (CV) and preparative electrolysis techniques. The results show that electron transfer between TEMPO + and a neutral substrate occurs with an efficiency that depends upon the presence of a base. The preparative scale electrolysis led to the formation of dihydro-isoquinolinones, isochromanone and xanthenone in moderate to excellent yields. On the basis of the CV analysis and preparative electrolysis results, a reaction mechanism is proposed

  6. Magnetotelluric Transfer Functions: Phase Tensor and Tipper Vector above a Simple Anisotropic Three-Dimensional Conductivity Anomaly and Implications for 3D Isotropic Inversion

    Science.gov (United States)

    Löwer, Alexander; Junge, Andreas

    2017-05-01

    The influence of anisotropic conductivity structures on magnetotelluric transfer functions is not easy to analyse in its entire complexity. In this study, we investigate the spatial and frequency-dependent behaviour of phase tensors and tipper vectors above a 3D anisotropic conductivity anomaly. The anomaly consists of a simple cubic block embedded in a homogeneous half space. Using a 3D FD code, we compare an isotropic, 2 anisotropic models with an anisotropy factor of 10 and one anisotropic model with the anisotropy factor of 100. The results show characteristic differences between the isotropic and anisotropic cases. For the anisotropic anomalies, the tipper vectors are parallel over the entire area despite the 3D geometry of the anomalous body. The size of the tipper vectors depends on the position of the site relative to the anomaly's boundaries and the direction of the anisotropic strike. Above the anomalous anisotropic body, the main diagonal elements of the phase tensor show the well-known split. Outside the anomaly, the phase tensor principal axis rotates according to the site position in contrast to the constant tipper direction. The 3D inversion of the forward data using an isotropic 3D code (ModEM) yields a very good fit for all cases. Whereas the inversion result matches the isotropic model, wave-like structures with high conductivity contrast occur for the anisotropic models. These structures extend far beyond the extension of the original anomalous body. Thus, the study reveals important indications of the existence of anisotropic conductivity structures for observed magnetotelluric transfer functions.

  7. Delayed circadian phase is linked to glutamatergic functions in young people with affective disorders: a proton magnetic resonance spectroscopy study.

    Science.gov (United States)

    Naismith, Sharon L; Lagopoulos, Jim; Hermens, Daniel F; White, Django; Duffy, Shantel L; Robillard, Rebecca; Scott, Elizabeth M; Hickie, Ian B

    2014-12-11

    While the association between affective disorders and sleep and circadian disturbance is well established, little is known about the neurobiology underpinning these relationships. In this study, we sought to determine the relationship between a marker of circadian rhythm and neuronal integrity (N-Acetyl Aspartate, NAA), oxidative stress (glutathione, GSH) and neuronal-glial dysfunction (Glutamate + Glutamine, Glx). Fifty-three young adults (age range 15-33 years, mean = 21.8, sd = 4.3) with emerging affective disorders were recruited from a specialized tertiary referral service. Participants underwent clinical assessment and actigraphy monitoring, from which sleep midpoint was calculated as a marker of circadian rhythm. Proton magnetic resonance spectroscopy was performed in the anterior cingulate cortex (ACC). The metabolites NAA, GSH and Glx were obtained, and expressed as a ratio to Creatine. Neither NAA or GSH were associated with sleep midpoint. However, higher levels of ACC Glx were associated with later sleep midpoints (rho = 0.35, p = 0.013). This relationship appeared to be independent of age and depression severity. This study is the first to demonstrate that delayed circadian phase is related to altered glutamatergic processes. It is aligned with animal research linking circadian rhythms with glutamatergic neurotransmission as well as clinical studies showing changes in glutamate with sleep interventions. Further studies may seek to examine the role of glutamate modulators for circadian misalignment.

  8. Coherence and phase locking in the scalp EEG and between LORETA model sources, and microstates as putative mechanisms of brain temporo-spatial functional organization.

    Science.gov (United States)

    Lehmann, Dietrich; Faber, Pascal L; Gianotti, Lorena R R; Kochi, Kieko; Pascual-Marqui, Roberto D

    2006-01-01

    Brain electric mechanisms of temporary, functional binding between brain regions are studied using computation of scalp EEG coherence and phase locking, sensitive to time differences of few milliseconds. However, such results if computed from scalp data are ambiguous since electric sources are spatially oriented. Non-ambiguous results can be obtained using calculated time series of strength of intracerebral model sources. This is illustrated applying LORETA modeling to EEG during resting and meditation. During meditation, time series of LORETA model sources revealed a tendency to decreased left-right intracerebral coherence in the delta band, and to increased anterior-posterior intracerebral coherence in the theta band. An alternate conceptualization of functional binding is based on the observation that brain electric activity is discontinuous, i.e., that it occurs in chunks of up to about 100 ms duration that are detectable as quasi-stable scalp field configurations of brain electric activity, called microstates. Their functional significance is illustrated in spontaneous and event-related paradigms, where microstates associated with imagery- versus abstract-type mentation, or while reading positive versus negative emotion words showed clearly different regions of cortical activation in LORETA tomography. These data support the concept that complete brain functions of higher order such as a momentary thought might be incorporated in temporal chunks of processing in the range of tens to about 100 ms as quasi-stable brain states; during these time windows, subprocesses would be accepted as members of the ongoing chunk of processing.

  9. Increased plasma donepezil concentration improves cognitive function in patients with dementia with Lewy bodies: An exploratory pharmacokinetic/pharmacodynamic analysis in a phase 3 randomized controlled trial.

    Science.gov (United States)

    Mori, Etsuro; Ikeda, Manabu; Nakai, Kenya; Miyagishi, Hideaki; Nakagawa, Masaki; Kosaka, Kenji

    2016-07-15

    To investigate whether increasing plasma donepezil concentration further improves cognitive function and neuropsychiatric symptoms without compromising safety in patients with dementia with Lewy bodies (DLB). We analyzed data from a 12-week phase 3 trial of donepezil (5 and 10mg/day) in patients with DLB. The contribution of factors affecting plasma donepezil concentration was evaluated using multivariate regression analysis. The relationships between plasma donepezil concentration and efficacy (cognitive function as measured by the Mini-Mental State Examination [MMSE], hallucinations and cognitive fluctuation), or safety (blood pressure, pulse rate, body weight, and parkinsonism as measured by the Unified Parkinson's Disease Rating Scale part III) were assessed by scatterplots and Pearson correlation. The data of 87 patients were used in the analyses. Plasma donepezil concentration increased proportionally with increasing dose from 5 to 10mg/day. The dose (contribution rate: 0.39, pdonepezil concentration. Plasma donepezil concentration correlated significantly with improvement of MMSE score (p=0.040), but no significant correlations were found with the change in other tested parameters. Plasma donepezil concentration correlated positively with change in cognitive function without affecting safety, and was affected mainly by dose and to a lesser extent by age. Therefore, for patients in whom safety concerns are not found at donepezil 5mg/day, increasing the dose to 10mg/day to increase plasma concentration is worthwhile to further improve cognitive function. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Trans-Resveratrol Supplementation and Endothelial Function during the Fasting and Postprandial Phase: A Randomized Placebo-Controlled Trial in Overweight and Slightly Obese Participants.

    Science.gov (United States)

    van der Made, Sanne M; Plat, Jogchum; Mensink, Ronald P

    2017-06-12

    Studies on the effects of the long-term intake of trans -resveratrol on vascular function are conflicting. In addition, postprandial effects of long-term trans- resveratrol intake on endothelial function are not known. We therefore supplemented 45 overweight and slightly obese volunteers (25 men and 20 women) with a mean (±SD) age of 61 ± 7 years and body mass index of 28.3 ± 3.2 kg/m² in random order trans -resveratrol (2 × 75 mg/day) or placebo capsules for 4 weeks, separated by a washout period of at least 4 weeks. At the end of each intervention period, brachial artery flow-mediated vasodilation (FMD) was measured before and after meal consumption. Plasma biomarkers for endothelial function, inflammation, and glucose and lipid metabolism were also determined. Compared with the placebo, trans -resveratrol did not affect fasting FMD (2.9 ± 1.4% vs. 3.0 ± 1.9%; p = 0.69). After the postprandial test, changes in FMD (-0.7 ± 2.3% vs. 0.2 ± 2.6%; p = 0.13) were also not significantly different. Postprandial changes in biomarkers were also comparable. In conclusion, for overweight and slightly obese volunteers, a daily intake of 150 mg of trans -resveratrol for 4 weeks does not change plasma biomarkers of endothelial function or inflammation in the fasting state or postprandial phase.

  11. [Changes in quality of life and work function during phase prophylactic lamotrigine treatment in bipolar patients: 6 month, prospective, observational study].

    Science.gov (United States)

    Gonda, Xenia; Kalman, Janos; Dome, Peter; Rihmer, Zoltan

    2016-03-01

    Bipolar disorder is a lifelong illness requiring lifelong pharmacotherapy. Therefore besides symptomatic remission, achievement of full work-related functioning and restoration of quality of life is a priority during successful treatment. The present prospective, observational, non-intervention study focused on investigating the effect of lamotrigine therapy on the quality of life and work-related function of bipolar patients in outpatient care. 969 bipolar or schizoaffective outpatients participated in the study who previously did not receive lamotrigine therapy. Our present phase-prophylactic study was a prospective, observational, non-intervention study with a six-month follow-up. Evaluations took place at baseline and at months 1, 2, 3 and 6. Patients were followed with a Clinical Global Impression-Severity (CGI-S) and Clinical Global Impression-Improvement (CGI-I). Changes in work-related function was evaluated using Social Adjustment Scale (SAS), while quality of life was assessed with the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q) scale. SAS scoreds showed a consistent decrease in the overall sample and in all CGI-S initial groups reflecting the improvement of work-related function during the six months of the follow-up. Q-LES-Q values in the whole sample and in all initial CGI-S groups showed a steady increase indicating a continuous increase in quality of life during the study. Our results indicate that during long-term prophylactic lamotrigine therapy the work function and quality of life of bipolar patients shows a significant improvement, therefore lamotrigine provides a possibility for full functional remission and restoration of quality of life.

  12. Community and team member factors that influence the early phase functioning of community prevention teams: the PROSPER project.

    Science.gov (United States)

    Greenberg, Mark T; Feinberg, Mark E; Meyer-Chilenski, Sarah; Spoth, Richard L; Redmond, Cleve

    2007-11-01

    This research examines the early development of community teams in a specific university-community partnership project called PROSPER (Spoth et al., Prev Sci 5:31-39, 2004). PROSPER supports local community teams in rural areas and small towns to implement evidence-based programs intended to support positive youth development and reduce early substance use. The study evaluated 14 community teams and included longitudinal data from 108 team members. Specifically, it examined how community demographics and team member characteristics, perceptions, and attitudes at initial team formation were related to local team functioning 6 months later, when teams were planning for prevention program implementation. Findings indicate that community demographics (poverty), perceived community readiness, characteristics of local team members (previous collaborative experience) and attitudes toward prevention played a substantial role in predicting the quality of community team functioning 6 months later. EDITORS' STRATEGIC IMPLICATIONS: The authors identify barriers to successful long-term implementation of prevention programs and add to a small, but important, longitudinal research knowledge base related to community coalitions.

  13. An algorithm to determine backscattering ratio and single scattering albedo

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, T.; Desa, E.; Matondkar, S.G.P.; Mascarenhas, A.A.M.Q.; Nayak, S.R.; Naik, P.

    and backscattering coefficients and the remote sensing reflectance are used to obtain a relationship for the backscattering ratio, which is defined as the ratio of the total backscattering to the total scattering in terms of the remote sensing reflectance of two...

  14. Functional

    Directory of Open Access Journals (Sweden)

    Fedoua Gandia

    2014-07-01

    Full Text Available The study was carried out to investigate the effects of inhaled Mg alone and associated with F in the treatment of bronchial hyperresponsiveness. 43 male Wistar rats were randomly divided into four groups and exposed to inhaled NaCl 0.9%, MeCh, MgSO4 and MgF2. Pulmonary changes were assessed by means of functional tests and quantitative histological examination of lungs and trachea. Results revealed that delivery of inhaled Mg associated with F led to a significant decrease of total lung resistance better than inhaled Mg alone (p < 0.05. Histological examinations illustrated that inhaled Mg associated with F markedly suppressed muscular hypertrophy (p = 0.034 and bronchoconstriction (p = 0.006 in MeCh treated rats better than inhaled Mg alone. No histological changes were found in the trachea. This study showed that inhaled Mg associated with F attenuated the main principle of the central components of changes in MeCh provoked experimental asthma better than inhaled Mg alone, potentially providing a new therapeutic approach against asthma.

  15. 1-(2-Formamidoethyl)-3-phenylurea functionalized activated carbon for selective solid-phase extraction and preconcentration of metal ions.

    Science.gov (United States)

    Tu, Zhifeng; He, Qun; Chang, Xijun; Hu, Zheng; Gao, Ru; Zhang, Lina; Li, Zhenhua

    2009-09-07

    A novel method that utilizes 1-(2-formamidoethyl)-3-phenylurea-modified activated carbon (AC-1-(2-formamidoethyl)-3-phenylurea) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace levels of Cr(III), Cu(II), Fe(III) and Pb(II) were optimized using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4. And the adsorbed metal ions could be completely eluted by using 2.0 mL 2.0 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.8, 39.9, 77.8 and 17.3 mg g(-1) for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The detection limits of the method were found to be 0.15, 0.41, 0.27 and 0.36 ng mL(-1) for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The relative standard deviation (RSD) of the method was lower than 4.0% (n=8). The method was successfully applied for the preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) in natural and certified samples with satisfactory results.

  16. Inter-cohort cannibalism of early benthic phase blue king crabs (Paralithodes platypus: alternate foraging strategies in different habitats lead to different functional responses.

    Directory of Open Access Journals (Sweden)

    Benjamin Daly

    Full Text Available Blue king crabs (Paralithodes platypus are commercially and ecologically important in Alaska, USA, but population abundances have fluctuated over the past several decades likely resulting from a combination of environmental and biological factors, including recruitment variability. Cannibalism between cohorts may be a source of mortality limiting recruitment success in the wild, but the degree of inter-cohort cannibalism is unknown for early benthic phase blue king crabs. In laboratory experiments, we evaluated the effects of habitat type (sand and shell on the predator functional response and foraging behavior of year-1 blue king crabs as predators of year-0 conspecifics and examined the effects of predator presence on crypsis of prey crabs. In sand, consumption rates increased with predator size and prey density until satiation, while predation rates in shell were low regardless of predator size or prey density. These differential predation rates yielded a type III functional response in sand but a type I functional response in shell habitat. Crypsis of prey crabs was generally high and did not change in the presence of predators. Predator foraging activity was reduced in shell and may be an adaptive behavior to balance foraging efficiency and susceptibility to larger predators. Our results demonstrate that early benthic phase blue king crabs are cannibalistic between cohorts in the laboratory and that shell material is extremely effective for reducing encounter rates with conspecific predators. The distribution and abundance of such habitat may be important for recruitment success in some populations. Future studies should compare benthic habitat and species assemblages in areas with variable abundances, such as the Pribilof Islands and Saint Matthew Island in the eastern Bering Sea, to better understand possible mechanisms for recruitment variability.

  17. Novel Functionalized Polythiophene-Coated Fe3O4 Nanoparticles for Magnetic Solid-Phase Extraction of Phthalates

    Directory of Open Access Journals (Sweden)

    Siti Nor Atika Baharin

    2016-04-01

    Full Text Available Poly(phenyl-(4-(6-thiophen-3-yl-hexyloxy-benzylidene-amine (P3TArH was successfully synthesized and coated on the surface of Fe3O4 magnetic nanoparticles (MNPs. The nanocomposites were characterized by Fourier transform infra-red (FTIR, X-ray diffractometry (XRD, Brunauer-Emmett-Teller (BET surface area analysis, analyzer transmission electron microscopy (TEM and vibrating sample magnetometry (VSM. P3TArH-coated MNPs (MNP@P3TArH showed higher capabilities for the extraction of commonly-used phthalates and were optimized for the magnetic-solid phase extraction (MSPE of environmental samples. Separation and determination of the extracted phthalates, namely dimethyl phthalate (DMP, diethyl phthalate (DEP, dipropyl phthalate (DPP, dibutyl phthalate (DBP, butyl benzyl phthalate (BBP, dicyclohexyl phthalate (DCP, di-ethylhexyl phthalate (DEHP and di-n-octyl phthalate (DNOP, were conducted by a gas chromatography-flame ionization detector (GC-FID. The best working conditions were as follows; sample at pH 7, 30 min extraction time, ethyl acetate as the elution solvent, 500-µL elution solvent volumes, 10 min desorption time, 10-mg adsorbent dosage, 20-mL sample loading volume and 15 g·L−1 concentration of NaCl. Under the optimized conditions, the analytical performances were determined with a linear range of 0.1–50 µg·L−1 and a limit of detection at 0.08–0.468 µg·L−1 for all of the analytes studied. The intra-day (n = 7 and inter-day (n = 3 relative standard deviations (RSD% of three replicates were each demonstrated in the range of 3.7–4.9 and 3.0–5.0, respectively. The steadiness and reusability studies suggested that the MNP@P3TArH could be used up to five cycles. The proposed method was executed for the analysis of real water samples, namely commercial bottled mineral water and bottled fresh milk, whereby recoveries in the range of 68%–101% and RSD% lower than 7.7 were attained.

  18. Development of a solid-phase extraction-enzyme-linked immunosorbent assay for the determination of 17beta-19-nortestosterone levels in antifatigue functional foods.

    Science.gov (United States)

    Zhang, Yan; Pan, Tao; Fang, Guozhen; Ma, Dongyue; Wang, Shuo

    2009-10-01

    17beta-19-nortestosterone (17beta-NT) has been illegally used in antifatigue functional foods to promote muscle growth and improve endurance. A rapid and sensitive solid-phase extraction-enzyme-linked immunosorbent assay (SPE-ELISA) method was developed and successfully applied to analyze the levels of 17beta-NT in antifatigue functional foods. A polyclonal antibody against 17beta-NT was produced from rabbits immunized with the 17beta-NT-BSA conjugate, and a competitive direct enzyme-linked immunosorbent assay was developed for the rapid detection of 17beta-NT. The concentration causing 50% inhibition (IC(50)) and the limit of detection (LOD) were found to be 0.08 and 0.0055 ng/mL, respectively; this was better than methods previously reported that had a LOD of 2.4 ng/mL. C(18) cartridges were investigated for use in removing the effects of matrix in foods, and the sample purification protocol was optimized. Using the developed SPE-ELISA method, recoveries of functional food samples were obtained in the range of 71% to 91.5%. Moreover, 2 kinds of antifatigue functional foods were analyzed using the established ELISA and HPLC methods. The correlation coefficient of the results obtained using the 2 methods was greater than 0.98. Thus, the preliminary evaluation of the SPE-ELISA method proved that it is a specific, sensitive, and precise tool that can be used for the practical detection of 17beta-NT in various antifatigue functional food samples.

  19. A Technical Assessment of the Utility of Reverse Phase Protein Arrays for the Study of the Functional Proteome in Non-microdissected Human Breast Cancers.

    LENUS (Irish Health Repository)

    Hennessy, Bryan T

    2010-12-01

    INTRODUCTION: The lack of large panels of validated antibodies, tissue handling variability, and intratumoral heterogeneity potentially hamper comprehensive study of the functional proteome in non-microdissected solid tumors. The purpose of this study was to address these concerns and to demonstrate clinical utility for the functional analysis of proteins in non-microdissected breast tumors using reverse phase protein arrays (RPPA). METHODS: Herein, 82 antibodies that recognize kinase and steroid signaling proteins and effectors were validated for RPPA. Intraslide and interslide coefficients of variability were <15%. Multiple sites in non-microdissected breast tumors were analyzed using RPPA after intervals of up to 24 h on the benchtop at room temperature following surgical resection. RESULTS: Twenty-one of 82 total and phosphoproteins demonstrated time-dependent instability at room temperature with most variability occurring at later time points between 6 and 24 h. However, the 82-protein functional proteomic "fingerprint" was robust in most tumors even when maintained at room temperature for 24 h before freezing. In repeat samples from each tumor, intratumoral protein levels were markedly less variable than intertumoral levels. Indeed, an independent analysis of prognostic biomarkers in tissue from multiple tumor sites accurately and reproducibly predicted patient outcomes. Significant correlations were observed between RPPA and immunohistochemistry. However, RPPA demonstrated a superior dynamic range. Classification of 128 breast cancers using RPPA identified six subgroups with markedly different patient outcomes that demonstrated a significant correlation with breast cancer subtypes identified by transcriptional profiling. CONCLUSION: Thus, the robustness of RPPA and stability of the functional proteomic "fingerprint" facilitate the study of the functional proteome in non-microdissected breast tumors.

  20. Functional resting-state fMRI connectivity correlates with serum levels of the S100B protein in the acute phase of traumatic brain injury

    Directory of Open Access Journals (Sweden)

    William Hedley Thompson

    2016-01-01

    Full Text Available The S100B protein is an intra-cellular calcium-binding protein that mainly resides in astrocytes in the central nervous system. The serum level of S100B is used as biomarker for the severity of brain damage in traumatic brain injury (TBI patients. In this study we investigated the relationship between intrinsic resting-state brain connectivity, measured 1–22 days (mean 8 days after trauma, and serum levels of S100B in a patient cohort with mild-to-severe TBI in need of neuro-intensive care in the acute phase. In line with previous investigations, our results show that the peak level of S100B acquired during the acute phase of TBI was negatively correlated with behavioral measures (Glasgow Outcome Score, GOS of functional outcome assessed 6 to 12 months post injury. Using a multi-variate pattern analysis-informed seed-based correlation analysis, we show that the strength of resting-state brain connectivity in multiple resting-state networks was negatively correlated with the peak of serum levels of S100B. A negative correspondence between S100B peak levels recorded 12–36 h after trauma and intrinsic connectivity was found for brain regions located in the default mode, fronto-parietal, visual and motor resting-state networks. Our results suggest that resting-state brain connectivity measures acquired during the acute phase of TBI is concordant with results obtained from molecular biomarkers and that it may hold a capacity to predict long-term cognitive outcome in TBI patients.

  1. Synthesis of multi-wavelength temporal phase-shifting algorithms optimized for high signal-to-noise ratio and high detuning robustness using the frequency transfer function.

    Science.gov (United States)

    Servin, Manuel; Padilla, Moises; Garnica, Guillermo

    2016-05-02

    Synthesis of single-wavelength temporal phase-shifting algorithms (PSA) for interferometry is well-known and firmly based on the frequency transfer function (FTF) paradigm. Here we extend the single-wavelength FTF-theory to dual and multi-wavelength PSA-synthesis when several simultaneous laser-colors are present. The FTF-based synthesis for dual-wavelength (DW) PSA is optimized for high signal-to-noise ratio and minimum number of temporal phase-shifted interferograms. The DW-PSA synthesis herein presented may be used for interferometric contouring of discontinuous industrial objects. Also DW-PSA may be useful for DW shop-testing of deep free-form aspheres. As shown here, using the FTF-based synthesis one may easily find explicit DW-PSA formulae optimized for high signal-to-noise and high detuning robustness. To this date, no general synthesis and analysis for temporal DW-PSAs has been given; only ad hoc DW-PSAs formulas have been reported. Consequently, no explicit formulae for their spectra, their signal-to-noise, their detuning and harmonic robustness has been given. Here for the first time a fully general procedure for designing DW-PSAs (or triple-wavelengths PSAs) with desire spectrum, signal-to-noise ratio and detuning robustness is given. We finally generalize DW-PSA to higher number of wavelength temporal PSAs.

  2. Structural, bonding, and electronic properties of the hexagonal ferroelectric and paraelectric phases of LuMnO{sub 3} compound: A density functional theory study

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, A. M.; Coutinho, W. S.; Lima, A. F.; Lalic, M. V., E-mail: mlalicbr@gmail.com [Physics Department, Federal University of Sergipe, São Cristóvão 49100-000 (Brazil)

    2015-02-21

    We have investigated the structural, bonding, and electronic properties of both ferroelectric (FE) and paraelectric (PE) phases of the hexagonal LuMnO{sub 3} compound using calculations based on density functional theory. The structural properties have been determined by employing the generalized gradient approximation with Perdew-Burke-Ernzerhof and Wu-Cohen parameterization. The bonding and electronic properties have been treated by recently developed modified Becke-Johnson exchange potential, which succeeded to open a band gap for both PE and FE phases, in agreement with experimental predictions. The Bader’s topological analysis of electronic density showed that the character of the Lu–O axial bonds changes when the crystal exhibits the PE → FE structural transition. This fact is in agreement with experimental findings. The covalent character of the Lu–O bond significantly increases due to orbital hybridization between the Lu 5d{sub z}{sup 2} and O 2p{sub z}-states. This bonding mechanism causes the ferroelectricity in the hexagonal LuMnO{sub 3} compound.

  3. Phase stability and elastic properties of β Ti-Nb-X (X = Zr, Sn) alloys: an ab initio density functional study

    Science.gov (United States)

    K, Rajamallu; Niranjan, Manish K.; Ameyama, Kei; Dey, Suhash R.

    2017-12-01

    Alloying effects of Zr and Sn on β phase stability and elastic properties in Ti-Nb alloys are investigated within the framework of first-principles density functional theory. Our results suggest that the stability of β phase can be significantly enhanced by the addition of Zr and Sn in Ti-Nb alloys. The computed results indicate that Zr and Sn behave as strong β stabilizers in the Ti-Nb system. The elastic properties are found to be altered considerably by the addition of ternary alloying elements (Zr and Sn). The computed elastic moduli of Ti18.75 at%Nb6.25 at%Zr and Ti25 at%NbxZr compositions are found to be lower than that for Ti18.75 at%Nb6.25 at%Sn and Ti25 at%NbxSn system. The lowest value of ˜54 GPa is obtained for Ti25 at%Nb6.25 at%Zr composition. Furthermore, the directional Young’s modulus is found to be in the order of E 100 system.

  4. Closed-form solutions in stress-driven two-phase integral elasticity for bending of functionally graded nano-beams

    Science.gov (United States)

    Barretta, Raffaele; Fabbrocino, Francesco; Luciano, Raimondo; Sciarra, Francesco Marotti de

    2018-03-01

    Strain-driven and stress-driven integral elasticity models are formulated for the analysis of the structural behaviour of fuctionally graded nano-beams. An innovative stress-driven two-phases constitutive mixture defined by a convex combination of local and nonlocal phases is presented. The analysis reveals that the Eringen strain-driven fully nonlocal model cannot be used in Structural Mechanics since it is ill-posed and the local-nonlocal mixtures based on the Eringen integral model partially resolve the ill-posedeness of the model. In fact, a singular behaviour of continuous nano-structures appears if the local fraction tends to vanish so that the ill-posedness of the Eringen integral model is not eliminated. On the contrary, local-nonlocal mixtures based on the stress-driven theory are mathematically and mechanically appropriate for nanosystems. Exact solutions of inflected functionally graded nanobeams of technical interest are established by adopting the new local-nonlocal mixture stress-driven integral relation. Effectiveness of the new nonlocal approach is tested by comparing the contributed results with the ones corresponding to the mixture Eringen theory.

  5. Dynamic density functional theory with hydrodynamic interactions: theoretical development and application in the study of phase separation in gas-liquid systems.

    Science.gov (United States)

    Kikkinides, E S; Monson, P A

    2015-03-07

    Building on recent developments in dynamic density functional theory, we have developed a version of the theory that includes hydrodynamic interactions. This is achieved by combining the continuity and momentum equations eliminating velocity fields, so the resulting model equation contains only terms related to the fluid density and its time and spatial derivatives. The new model satisfies simultaneously continuity and momentum equations under the assumptions of constant dynamic or kinematic viscosity and small velocities and/or density gradients. We present applications of the theory to spinodal decomposition of subcritical temperatures for one-dimensional and three-dimensional density perturbations for both a van der Waals fluid and for a lattice gas model in mean field theory. In the latter case, the theory provides a hydrodynamic extension to the recently studied dynamic mean field theory. We find that the theory correctly describes the transition from diffusive phase separation at short times to hydrodynamic behaviour at long times.

  6. Phase I clinical trial of systemically administered TUSC2(FUS1-nanoparticles mediating functional gene transfer in humans.

    Directory of Open Access Journals (Sweden)

    Charles Lu

    Full Text Available Tumor suppressor gene TUSC2/FUS1 (TUSC2 is frequently inactivated early in lung cancer development. TUSC2 mediates apoptosis in cancer cells but not normal cells by upregulation of the intrinsic apoptotic pathway. No drug strategies currently exist targeting loss-of-function genetic abnormalities. We report the first in-human systemic gene therapy clinical trial of tumor suppressor gene TUSC2.Patients with recurrent and/or metastatic lung cancer previously treated with platinum-based chemotherapy were treated with escalating doses of intravenous N-[1-(2,3-dioleoyloxypropyl]-N,N,N-trimethylammonium chloride (DOTAP:cholesterol nanoparticles encapsulating a TUSC2 expression plasmid (DOTAP:chol-TUSC2 every 3 weeks.Thirty-one patients were treated at 6 dose levels (range 0.01 to 0.09 milligrams per kilogram. The MTD was determined to be 0.06 mg/kg. Five patients achieved stable disease (2.6-10.8 months, including 2 minor responses. One patient had a metabolic response on positron emission tomography (PET imaging. RT-PCR analysis detected TUSC2 plasmid expression in 7 of 8 post-treatment tumor specimens but not in pretreatment specimens and peripheral blood lymphocyte controls. Proximity ligation assay, performed on paired biopsies from 3 patients, demonstrated low background TUSC2 protein staining in pretreatment tissues compared with intense (10-25 fold increase TUSC2 protein staining in post-treatment tissues. RT-PCR gene expression profiling analysis of apoptotic pathway genes in two patients with high post-treatment levels of TUSC2 mRNA and protein showed significant post-treatment changes in the intrinsic apoptotic pathway. Twenty-nine genes of the 82 tested in the apoptosis array were identified by Igenuity Pathway Analysis to be significantly altered post-treatment in both patients (Pearson correlation coefficient 0.519; p<0.01.DOTAP:chol-TUSC2 can be safely administered intravenously in lung cancer patients and results in uptake of the gene

  7. The spectroscopic (FT-IR, FT-IR gas phase, FT-Raman and UV) and NBO analysis of 4-Hydroxypiperidine by density functional method.

    Science.gov (United States)

    Sebastian, S; Sundaraganesan, N

    2010-03-01

    In this work, we report a combined experimental and theoretical study on molecular structure, vibrational spectra, NBO and UV-spectral analysis of 4-Hydroxypiperidine (4-HP). The FT-IR solid phase (4000-400 cm(-1)), FT-IR gas phase (5000-400 cm(-1)) and FT-Raman spectra (3500-50 cm(-1)) of 4-HP was recorded. The molecular geometry, harmonic vibrational frequencies and bonding features of 4-HP in the ground-state have been calculated by using the density functional methods (BLYP, B3LYP) with 6-311G (d,p) as basis set. The assignments of the vibrational spectra have been carried out with the help of normal co-ordinate analysis (NCA) following the Scaled Quantum Mechanical Force Field Methodology (SQMFF). Stability of the molecule arising from hyperconjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) in the sigma* antibonding orbitals and E (2) energies confirms the occurrence of ICT (Intra-molecular Charge Transfer) within the molecule. The UV spectrum was measured in ethanol solution. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) result complements the experimental findings. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Finally the calculation results were applied to simulated infrared and Raman spectra of the title compound which show good agreement with observed spectra. Copyright 2009 Elsevier B.V. All rights reserved.

  8. Quantitative relationships between thallium-201 estimated myocardial infarct size and left ventricular function in the acute or convalescent phase of the first attack of myocardial infarction

    International Nuclear Information System (INIS)

    Kataoka, Hajime; Ueda, Keiji; Sakai, Makoto

    1983-01-01

    Correlations between left ventricular (LV) function and infarct size estimated by computer-assisted thallium (Tl)-201 scintigraphy were studied in 16 patients in the acute or convalescent phase of the first attack of transmural myocardial infarction (MI). Tl-201 estimation of the infarct size was done using a ''corrected'' circumferential profile method, by which the total defect score could be obtained. The LV function was evaluated by radionuclide angiography, echocardiography and cardiac catheterization study. The following results were obtained: 1) A close inverse relationship was found between the defect score and the ejection fraction (r = -0.649, p < 0.01). 2) The linear correlation coefficient was 0.540 (p < 0.05) between the defect score and the pulmonary arterial end-diastolic pressure and -0.616 (p < 0.02) between the defect score and the stroke volume index. There was no significant correlation between the defect score and the cardiac index. 3) There was a linear correlation between the defect score and the LV end-diastolic dimension (r = -0.852, p < 0.001). However, there was no relation between the defect score and the left atrial dimension. When the LV indices were compared between the small (S) and the large (L) defect score group, the L defect group had faster heart rate, larger LV chamber size and the smaller stroke volume index than the S defect group. However, there was no significant difference in the cardiac index between these 2 groups. These results suggest that the LV dilatation in acute or convalescent phase of the first attack of transmural MI is an ominous sign because it was usually accompanied by large infarct size. The present study also indicates that LV dilatation accompanying a large infarct does not satisfactorily compensate for LV dysfunction by Frank-Starling mechanism. (J.P.N.)

  9. Acrylamide-functionalized graphene micro-solid-phase extraction coupled to high-performance liquid chromatography for the online analysis of trace monoamine acidic metabolites in biological samples.

    Science.gov (United States)

    Yang, Xiaoting; Hu, Yufei; Li, Gongke; Zhang, Zhuomin

    2015-05-01

    Monoamine acidic metabolites in biological samples are essential biomarkers for the diagnosis of neurological disorders. In this work, acrylamide-functionalized graphene adsorbent was successfully synthesized by a chemical functionalization method and was packed in a homemade polyether ether ketone micro column as a micro-solid-phase extraction unit. This micro-solid-phase extraction unit was directly coupled to high-performance liquid chromatography to form an online system for the separation and analysis of three monoamine acidic metabolites including homovanillic acid, 5-hydroxyindole-3-acetic acid, and 3,4-dihydroxyphenylacetic acid in human urine and plasma. The online system showed high stability, permeability, and adsorption capacity toward target metabolites. The saturated extraction amount of this online system was 213.1, 107.0, and 153.4 ng for homovanillic acid, 5-hydroxyindole-3-acetic acid, and 3,4-dihydroxyphenylacetic acid, respectively. Excellent detection limits were achieved in the range of 0.08-0.25 μg/L with good linearity and reproducibility. It was interesting that three targets in urine and plasma could be actually quantified to be 0.94-3.93 μg/L in plasma and 7.15-19.38 μg/L in urine. Good recoveries were achieved as 84.8-101.4% for urine and 77.8-95.1% for plasma with the intra- and interday relative standard deviations less than 9.3 and 10.3%, respectively. This method shows great potential for online analysis of trace monoamine acidic metabolites in biological samples. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Tilt Angle and the Temperature Shifts Calculated as a Function of Concentration for the AC* Phase Transition in a Binary Mixture of Liquid Crystals

    Science.gov (United States)

    Yurtseven, H.; Kurt, M.

    We study here the tilt angle and the temperature shifts as a function of concentration for the AC* phase transition in a binary mixture, using our mean field model with the biquadratic P2θ2 coupling — and also with the bilinear Pθ and P2θ2 couplings. By expanding the free energy in terms of the tilt angle and polarization, the tilt angle and the temperature shift are evaluated by using the coefficients given in the free energy expansion. By employing a concentration-dependent coefficient, the tilt angle and the temperature shift are calculated as a function of concentration of 10.O.4 for the SmAC* transition in a binary mixture of C7 and 10.O.4. Our calculated values of the tilt angle and the temperature shifts decrease as the concentration of 10.O.4 increases, as confirmed experimentally for the AC* transition in this binary mixture. This indicates that our mean field models studied here are satisfactory to explain the observed behavior of the AC* transition of the binary mixture of C7 and 10.O.4.

  11. Functionalized hydrothermal carbon derived from waste pomelo peel as solid-phase extractant for the removal of uranyl from aqueous solution.

    Science.gov (United States)

    Li, Feize; Tang, Yu; Wang, Huilin; Yang, Jijun; Li, Shoujian; Liu, Jun; Tu, Hong; Liao, Jiali; Yang, Yuanyou; Liu, Ning

    2017-10-01

    To develop a high-performance solid-phase extractant for the separation of uranyl f, pomelo peel, a kind of waste biomass, has been employed as carbon source to prepare carbonaceous matrix through low-temperature hydrothermal carbonization (200 °C, 24 h). After being oxidized by Hummers method, the prepared hydrothermal carbon matrix was functionalized with carboxyl and phenolic hydroxyl groups (1.75 mmol g -1 ). The relevant characterizations and batch studies had demonstrated that the obtained carbon material possessed excellent affinity toward uranyl (436.4 mg g -1 ) and the sorption process was a spontaneous, endothermic and rapid chemisorption. The selective sorption of U(VI) from the simulated nuclear effluent demonstrated that the sorbent displayed a desirable selectivity (56.14% at pH = 4.5) for the U(VI) ions over the other 11 competitive cations from the simulated industrial nuclear effluent. The proposed synthetic strategy in the present work had turned out to be effective and practical, which provides a novel approach to prepare functional materials for the recovery and separation of uranyl or other heavy metals from aqueous environment.

  12. Phase-field-crystal dynamics for binary systems: Derivation from dynamical density functional theory, amplitude equation formalism, and applications to alloy heterostructures.

    Science.gov (United States)

    Huang, Zhi-Feng; Elder, K R; Provatas, Nikolas

    2010-08-01

    The dynamics of phase field crystal (PFC) modeling is derived from dynamical density functional theory (DDFT), for both single-component and binary systems. The derivation is based on a truncation up to the three-point direct correlation functions in DDFT, and the lowest order approximation using scale analysis. The complete amplitude equation formalism for binary PFC is developed to describe the coupled dynamics of slowly varying complex amplitudes of structural profile, zeroth-mode average atomic density, and system concentration field. Effects of noise (corresponding to stochastic amplitude equations) and species-dependent atomic mobilities are also incorporated in this formalism. Results of a sample application to the study of surface segregation and interface intermixing in alloy heterostructures and strained layer growth are presented, showing the effects of different atomic sizes and mobilities of alloy components. A phenomenon of composition overshooting at the interface is found, which can be connected to the surface segregation and enrichment of one of the atomic components observed in recent experiments of alloying heterostructures.

  13. Effectiveness of prophylactic non-invasive ventilation on respiratory function in the postoperative phase of pediatric cardiac surgery: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Camilla R. S. Silva

    Full Text Available ABSTRACT Objective To evaluate the effectiveness of prophylactic, non-invasive ventilation (NIV on respiratory function in seven- to 16-year-old children in the post-operative phase of cardiac surgery. Method A randomized, controlled trial with 50 children who had undergone cardiac surgery with median sternotomy. After extubation, patients were randomly assigned to one of two groups: control group (n=26, which received instructions regarding posture, early ambulation, and cough stimulation, and CPAP group (continuous positive airway pressure; n=24, which received the same instructions as the control group and CPAP=10 cmH20 twice daily for 30 minutes from the 1st to the 5th post-operative day (POD. As a primary outcome, lung function was evaluated before and on the 1st, 3rd, and 5th PODs with measures of respiratory rate (RR, tidal volume (TV, slow vital capacity (SVC, inspiratory capacity (IC, minute volume (MV, peak expiratory flow (PEF, and maximal inspiratory pressure (MIP. As secondary outcomes, the time of hospitalization and intensive care were recorded. A mixed, linear regression model and z-test were used to analyze respiratory function, considering p<0.05. Results All variables, except RR and MV, showed a significant drop on the 1st POD, with gradual recovery; however, only MIP had returned to pre-operative values on the 5th POD in both groups. The RR showed a significant increase on the 1st POD, with a gradual reduction but without returning to baseline. In the intergroup analysis, significant improvement (p=0.04 was observed only in PEF in the CPAP group on the 1st DPO. The length of hospitalization and intensive care showed no significant differences. Conclusion NIV was safe and well accepted in this group of patients, and the protocol used was effective in improving PEF on the 1st DPO in the CPAP group.

  14. Cell surface acid-base properties of Escherichia coli and Bacillus brevis and variation as a function of growth phase, nitrogen source and C:N ratio.

    Science.gov (United States)

    Hong, Yongsuk; Brown, Derick G

    2006-07-01

    Potentiometric titration has been conducted to systematically examine the acid-base properties of the cell surfaces of Escherichia coli K-12 and Bacillus brevis as a function of growth phase, nitrogen source (ammonium or nitrate), and carbon to nitrogen (C:N) ratio of the growth substrate. The two bacterial species revealed four distinct proton binding sites, with pK(a) values in the range of 3.08-4.05 (pK(1)), 4.62-5.57 (pK(2)), 6.47-7.30 (pK(3)), and 9.68-10.89 (pK(4)) corresponding to phosphoric/carboxylic, carboxylic, phosphoric, and hydroxyl/amine groups, respectively. Two general observations in the data are that for B. brevis the first site concentration (N(1)), corresponding to phosphoric/carboxylic groups (pK(1)), varied as a function of nitrogen source, while for E. coli the fourth site concentration (N(4)), corresponding to hydroxyl/amine groups (pK(4)), varied as a function of C:N ratio. Correspondingly, it was found that N(1) was the highest of the four site concentrations for B. brevis and N(4) was the highest for E. coli. The concentrations of the remaining sites showed little variation. Finally, comparison between the titration data and a number of cell surface compositional studies in the literature indicates one distinct difference between the two bacteria is that pK(4) of the Gram-negative E. coli can be attributed to hydroxyl groups while that of the Gram-positive B. brevis can be attributed to amine groups.

  15. Measurement of the Maximum Frequency of Electroglottographic Fluctuations in the Expiration Phase of Volitional Cough as a Functional Test for Cough Efficiency.

    Science.gov (United States)

    Iwahashi, Toshihiko; Ogawa, Makoto; Hosokawa, Kiyohito; Kato, Chieri; Inohara, Hidenori

    2017-10-01

    The hypotheses of the present study were that the maximum frequency of fluctuation of electroglottographic (EGG) signals in the expiration phase of volitional cough (VC) reflects the cough efficiency and that this EGG parameter is affected by impaired laryngeal closure, expiratory effort strength, and gender. For 20 normal healthy adults and 20 patients diagnosed with unilateral vocal fold paralysis (UVFP), each participant was fitted with EGG electrodes on the neck, had a transnasal laryngo-fiberscope inserted, and was asked to perform weak/strong VC tasks while EGG signals and a high-speed digital image of the larynx were recorded. The maximum frequency was calculated in the EGG fluctuation region coinciding with vigorous vocal fold vibration in the laryngeal HSDIs. In addition, each participant underwent spirometry for measurement of three aerodynamic parameters, including peak expiratory air flow (PEAF), during weak/strong VC tasks. Significant differences were found for both maximum EGG frequency and PEAF between the healthy and UVFP groups and between the weak and strong VC tasks. Among the three cough aerodynamic parameters, PEAF showed the highest positive correlation with the maximum EGG frequency. The correlation coefficients between the maximum EGG frequency and PEAF recorded simultaneously were 0.574 for the whole group, and 0.782/0.717/0.823/0.688 for the male/female/male-healthy/male-UVFP subgroups, respectively. Consequently, the maximum EGG frequency measured in the expiration phase of VC was shown to reflect the velocity of expiratory airflow to some extent and was suggested to be affected by vocal fold physical properties, glottal closure condition, and the expiratory function.

  16. Density functional investigations on electronic structures, magnetic ordering and ferroelectric phase transition in multiferroic Bi2NiMnO6

    Directory of Open Access Journals (Sweden)

    Hong Jian Zhao

    2012-06-01

    Full Text Available Using the full-potential linearised augmented-plane wave (FP-LAPW method based on density functional theory (DFT, we have investigated the electronic structures, the magnetic behavior, and the ferroelectric origin of multiferroic Bi2NiMnO6. The calculated ferromagnetic Curie temperature of Bi2NiMnO6 is very sensitive to the Mn4+—O2-—Ni2+ length. When average Mn4+—O2-—Ni2+ length increases from 3.82 to 4.05 Å, the Curie temperature increases from 179 to 295 K. The Mn4+—O2-—Ni2+ superexchange interaction due to the virtual hopping of electrons from O-2p filled states to Mn-/Ni-3d empty states is enhanced when the band gap formed by crystal-field splitting decreases, thus the effective exchange parameters and Curie temperature increase as Mn4+—O2-—Ni2+ length increases. The ferroelectric distortion in Bi2NiMnO6 is directly from the hybridization of Bi-6p and O-2p states. The role of Bi-6s2 lone pairs electrons may be that hybridized O-2p with Bi-6s orbitals may be more appropriate in compatible symmetry with Bi-6p orbital than O-2p orbital only. Furthermore, the route of ferroelectric distortion in Bi2NiMnO6 from paraelectric P21/n phase to ferroelectric C2 phase is discussed.

  17. The effects of breakfast on short-term cognitive function among Chinese white-collar workers: protocol for a three-phase crossover study

    Directory of Open Access Journals (Sweden)

    Zhenchuang Tang

    2017-01-01

    Full Text Available Abstract Background As the first meal of the day, breakfast plays an important role in supplying energy and nutrients, which are critical to working and learning activities. A three-phase crossover study was designed to investigate the effects of breakfast on cognitive function among Chinese white-collar workers. The planned study protocol is presented. Methods A total of 264 participants aged 25–45 years will be recruited from Shenyang and Chongqing. Self-administered questionnaires will be used to collect information on age, gender, marital status, education level, occupation, smoking habits, drinking habits, and breakfast behaviours. The participants will be randomly assigned to 3 equal-sized groups (Groups A, B, and C and will be provided with a nutrition-adequate breakfast, a nutrition-inadequate breakfast, or no breakfast, respectively. Each participant will receive the breakfast treatment on the basis of assignment to one of three sequences (ABC/BCA/CAB. Each participant will complete a battery of cognitive tests assessing short-term memory, attention, and working memory 120 minutes after breakfast. Mood will be measured through a self-administered questionnaire assessing the dimensions of positive and negative frames of mind. Additionally, fasting blood glucose and postprandial 2-hour blood glucose levels will be tested with a blood-glucose meter (Roche ACCU-CHEK®-Performa. All the participants will take all the tests in three successive weeks, and the order of presentation will be counter-balanced across groups. Discussion The present study will be the first investigation of the effect of breakfast food type and quality on cognitive function amongst white-collar workers in China. We predict that a nutrition-adequate breakfast, compared with a nutrition-inadequate breakfast and no breakfast, will significantly improve short-term cognitive function. The results of this study should provide scientific evidence of the effect of

  18. A case study of single hygroscopicity parameter and its link to the functional groups and phase transition for urban aerosols in Taipei City

    Science.gov (United States)

    Hung, Hui-Ming; Hsu, Chia-Hung; Lin, Wei-Ting; Chen, Yu-Quan

    2016-05-01

    The hygroscopicity, functional groups and phase transitions of urban aerosol particles in Taipei City were studied using a cloud condensation nuclei counter (CCNc) with a scanning mobility particle sizer (SMPS) and an attenuated total reflectance with infrared (ATR-IR) detection technique. With the assumption of larger particles being activated first, the derived single hygroscopicity parameter (κ) exhibited an increasing trend with particle size, i.e., from 0.022 ± 0.01 at 87 ± 10 nm to 0.13 ± 0.03 at 240 ± 20 nm. The collected size-selected particles were characterized using ATR-IR for the functional groups of alkyl, carbonyl, ammonium, sulfate and nitrate, which showed various size dependence patterns, linked to different formation mechanisms. The hygroscopic response based on the ratio (xW_solute) for sample film of absorption by the enhanced water-stretching peak to that by the selected solute showed a better consistency with pure ammonium sulfate for sub-micron size particles. Based on the derived ammonium sulfate volume fraction from IR analysis, the κ received from CCNc measurements was concluded mainly contributed by ammonium sulfate for sub-micrometer particles. The increasing trend of sodium nitrate absorbance at aerosol diameter ≥1 μm was due to a reaction of nitric acid with sea salt particles. The micrometer sized particles were apparent not only in a significantly higher xW_solute than pure sodium nitrate but also had a deliquescence RH of 69 ± 1%, similar to that of sodium nitrate-sodium chloride mixtures. Overall, the organic species in this study exhibited a low hygroscopicity with less than 0.036 of contribution for the overall κ, and the major hygroscopic material of urban aerosols consisted primarily of ammonium sulfate in the sub-micrometer particles and sodium nitrate with sea salt in the coarse particles.

  19. New Trend for Acceleration Solid Phase Extraction Process Based on Using Magnetic Nano-adsorbents along with Surface Functionalization through Microwave Assisted Solvent-free Technique.

    Science.gov (United States)

    Ahmed, Salwa A; Soliman, Ezzat M

    2015-01-01

    The use of a microwave assisted solvent-free technique for silica coating of iron magnetic nanoparticles (Fe3O4-MNPs) and their functionalization with three aliphatic diamines: 1,2-ethylenediamine (1,2EDA), 1,5-pentanediamine (1,5PDA) and 1.8-octanediamine (1,8-ODA), were successfully achieved in a very short time. Only 60 min were needed for the nano-adsorbent modification as compared with more than 1000 min using conventional methods under reflux conditions. Their surface characteristics (observed by TEM, XRD and FT-IR), in addition to Cu(II) adsorption capacities (1.805, 1.928 and 2.116 mmol g(-1)) and time of equilibration (5 s) were almost the same. Thus, the time required to accomplish the solid phase extraction process is greatly reduced. On the other hand, the phenomenon of the fast equilibration kinetics was successfully extended on using the functionalized aliphatic diamines magnetic nano-adsorbents as precursors for further microwave treatment. Three selective magnetic nano-adsorbents (Fe3O4-MNPs-SiO2-1,2EDA-3FSA, Fe3O4-MNPs-SiO2-1,5PDA-3FSA and Fe3O4-MNPs-SiO2-1,8ODA-3FSA) were obtained via the reaction with 3-formayl salicylic acid (3FSA) as a selective reagent for Fe(III). At 5 s contact time, they exhibited maximum Fe(III) uptake equal to 4.512, 4.987 and 5.367 mmol g(-1), respectively. Furthermore, modeling of values of metal uptake capacity obtained at different shaking time intervals supports pseudo-second order kinetics.

  20. Comfort and Functional Properties of Far-Infrared/Anion-Releasing Warp-Knitted Elastic Composite Fabrics Using Bamboo Charcoal, Copper, and Phase Change Materials

    Directory of Open Access Journals (Sweden)

    Ting-Ting Li

    2016-02-01

    Full Text Available Elastic warp-knitted composite fabrics with far-infrared emissivity and an anion-releasing property were prepared using bamboo charcoal (BC, copper (Cu, and phase-change material (PCM. The functional composite fabric, which was composed of self-made complex yarns with various twisting degrees and material composition, were created using a rotor twister and ring-spinning technique. The fabric structure was diversified by the feeding modes of weft yarn into a crochet-knitting machine. The twist number of complex yarns was optimized by tensile tenacity, twist contraction, and hairiness, and analysis showed that twisting at 12 twists per inch produced the highest tensile tenacity and appropriate twist contraction and hairiness. Comfort evaluation showed that the elastic composite fabrics with BC weft yarns exhibited higher water–vapor transmission rate and air permeability, reaching 876 g/m2∙ day and 73.2 cm3/s/cm2, respectively. Three structures of composite fabric with various weft yarns had >0.85 ε far-infrared emissivity and 350–420 counts/cm3 anion amount. The prepared elastic warp-knitted fabrics can provide a comfortable, dry, and breathable environment to the wearer and can thus be applied as health-care textiles in the future.

  1. Acid-yield measurements of the gas-phase ozonolysis of ethene as a function of humidity using Chemical Ionisation Mass Spectrometry (CIMS

    Directory of Open Access Journals (Sweden)

    K. E. Leather

    2012-01-01

    Full Text Available Gas-phase ethene ozonolysis experiments were conducted at room temperature to determine formic acid yields as a function of relative humidity (RH using the integrated EXTreme RAnge chamber-Chemical Ionisation Mass Spectrometry technique, employing a CH3I ionisation scheme. RHs studied were <1, 11, 21, 27, 30 % and formic acid yields of (0.07±0.01 and (0.41±0.07 were determined at <1 % RH and 30 % RH respectively, showing a strong water dependence. It has been possible to estimate the ratio of the rate coefficient for the reaction of the Criegee biradical, CH2OO with water compared with decomposition. This analysis suggests that the rate of reaction with water ranges between 1×10−12–1×10−15 cm3 molecule−1 s−1 and will therefore dominate its loss with respect to bimolecular processes in the atmosphere. Global model integrations suggest that this reaction between CH2OO and water may dominate the production of HC(OOH in the atmosphere.

  2. Advanced Power Electronic Interfaces for Distributed Energy Systems, Part 2: Modeling, Development, and Experimental Evaluation of Advanced Control Functions for Single-Phase Utility-Connected Inverter

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, S.; Kroposki, B.; Kramer, W.

    2008-11-01

    Integrating renewable energy and distributed generations into the Smart Grid architecture requires power electronic (PE) for energy conversion. The key to reaching successful Smart Grid implementation is to develop interoperable, intelligent, and advanced PE technology that improves and accelerates the use of distributed energy resource systems. This report describes the simulation, design, and testing of a single-phase DC-to-AC inverter developed to operate in both islanded and utility-connected mode. It provides results on both the simulations and the experiments conducted, demonstrating the ability of the inverter to provide advanced control functions such as power flow and VAR/voltage regulation. This report also analyzes two different techniques used for digital signal processor (DSP) code generation. Initially, the DSP code was written in C programming language using Texas Instrument's Code Composer Studio. In a later stage of the research, the Simulink DSP toolbox was used to self-generate code for the DSP. The successful tests using Simulink self-generated DSP codes show promise for fast prototyping of PE controls.

  3. Magnetic solid-phase extraction of non-steroidal anti-inflammatory drugs from environmental water samples using polyamidoamine dendrimer functionalized with magnetite nanoparticles as a sorbent.

    Science.gov (United States)

    Alinezhad, Heshmatollah; Amiri, Amirhassan; Tarahomi, Mehrasa; Maleki, Behrooz

    2018-06-01

    A novel polyamidoamine dendrimer functionalized with Fe 3 O 4 nanoparticles (Fe 3 O 4 @PAMAM) had been fabricated and used as magnetic solid-phase extraction (MSPE) adsorbent. The Fe 3 O 4 @PAMAM nanocomposites were characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, field-emission scanning electron spectroscopy, elemental analytical, and thermal gravimetric analysis. The MSPE method coupled with high-performance liquid chromatography with an ultraviolet detection system was applied for the separation/analysis of non-steroidal anti-inflammatory drugs (NSAIDs). Major parameters affecting the extraction efficiency of the selected drugs were optimized. Under optimal conditions, the enrichment factors for the proposed method were 701835. The linear range, limit of detection, correlation coefficient (r), and relative standard deviation (RSD) were found to be 0.15-500 ng mL -1 , 0.050.08 ng mL -1 , 0.99320.9967, and 4.5-7.0% (n = 5, 0.2, 10 and 300 ng mL -1 ), respectively. The method was successfully applied to the determination of NSAIDs in the real water samples. The recoveries of spiked water samples were in the range of 93.6-98.9% with RSDs varying from 6.1% to 9.0%, showing the good accuracy of the method. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. An empirical phase diagram approach to investigate conformational stability of "second-generation" functional mutants of acidic fibroblast growth factor-1.

    Science.gov (United States)

    Alsenaidy, Mohammad A; Wang, Tingting; Kim, Jae Hyun; Joshi, Sangeeta B; Lee, Jihun; Blaber, Michael; Volkin, David B; Middaugh, C Russell

    2012-03-01

    Acidic fibroblast growth factor-1 (FGF-1) is an angiogenic protein which requires binding to a polyanion such as heparin for its mitogenic activity and physicochemical stability. To evaluate the extent to which this heparin dependence on solution stability could be reduced or eliminated, the structural integrity and conformational stability of 10 selected FGF-1 mutants were examined as a function of solution pH and temperature by a series of spectroscopic methods including circular dichroism, intrinsic and extrinsic fluorescence spectroscopy and static light scattering. The biophysical data were summarized in the form of colored empirical phase diagrams (EPDs). FGF-1 mutants were identified with stability profiles in the absence of heparin comparable to that of wild-type FGF-1 in the presence of heparin while still retaining their biological activity. In addition, a revised version of the EPD methodology was found to provide an information rich, high throughput approach to compare the effects of mutations on the overall conformational stability of proteins in terms of their response to environmental stresses such as pH and temperature. Copyright © 2011 The Protein Society.

  5. Assessment of amide I spectroscopic maps for a gas-phase peptide using IR-UV double-resonance spectroscopy and density functional theory calculations

    International Nuclear Information System (INIS)

    Carr, J. K.; Roy, S.; Skinner, J. L.; Zabuga, A. V.; Rizzo, T. R.

    2014-01-01

    The spectroscopy of amide I vibrations has become a powerful tool for exploring protein structure and dynamics. To help with spectral interpretation, it is often useful to perform molecular dynamics (MD) simulations. To connect spectroscopic experiments to simulations in an efficient manner, several researchers have proposed “maps,” which relate observables in classical MD simulations to quantum spectroscopic variables. It can be difficult to discern whether errors in the theoretical results (compared to experiment) arise from inaccuracies in the MD trajectories or in the maps themselves. In this work, we evaluate spectroscopic maps independently from MD simulations by comparing experimental and theoretical spectra for a single conformation of the α-helical model peptide Ac-Phe-(Ala) 5 -Lys-H + in the gas phase. Conformation-specific experimental spectra are obtained for the unlabeled peptide and for several singly and doubly 13 C-labeled variants using infrared-ultraviolet double-resonance spectroscopy, and these spectra are found to be well-modeled by density functional theory (DFT) calculations at the B3LYP/6-31G** level. We then compare DFT results for the deuterated and 13 C 18 O-labeled peptide with those from spectroscopic maps developed and used previously by the Skinner group. We find that the maps are typically accurate to within a few cm −1 for both frequencies and couplings, having larger errors only for the frequencies of terminal amides

  6. Assessment of amide I spectroscopic maps for a gas-phase peptide using IR-UV double-resonance spectroscopy and density functional theory calculations.

    Science.gov (United States)

    Carr, J K; Zabuga, A V; Roy, S; Rizzo, T R; Skinner, J L

    2014-06-14

    The spectroscopy of amide I vibrations has become a powerful tool for exploring protein structure and dynamics. To help with spectral interpretation, it is often useful to perform molecular dynamics (MD) simulations. To connect spectroscopic experiments to simulations in an efficient manner, several researchers have proposed "maps," which relate observables in classical MD simulations to quantum spectroscopic variables. It can be difficult to discern whether errors in the theoretical results (compared to experiment) arise from inaccuracies in the MD trajectories or in the maps themselves. In this work, we evaluate spectroscopic maps independently from MD simulations by comparing experimental and theoretical spectra for a single conformation of the α-helical model peptide Ac-Phe-(Ala)5-Lys-H(+) in the gas phase. Conformation-specific experimental spectra are obtained for the unlabeled peptide and for several singly and doubly (13)C-labeled variants using infrared-ultraviolet double-resonance spectroscopy, and these spectra are found to be well-modeled by density functional theory (DFT) calculations at the B3LYP/6-31G** level. We then compare DFT results for the deuterated and (13)C(18)O-labeled peptide with those from spectroscopic maps developed and used previously by the Skinner group. We find that the maps are typically accurate to within a few cm(-1) for both frequencies and couplings, having larger errors only for the frequencies of terminal amides.

  7. Experience with the functional assessment of cancer therapy-lung (FACT-L) in ECOG 4593, a phase II hyperfractionated accelerated radiation therapy (HART) trial

    International Nuclear Information System (INIS)

    Mehta, M.P.; Adak, S.; Wagner, H.; Cella, D.

    1997-01-01

    PURPOSE: To gain experience in measuring quality of life (QOL) using the FACT-L in patients (pt) with non small cell lung cancer (NSCLC) treated with an altered fractionation regimen, HART, in a Phase II, multiinstitutional ECOG trial. MATERIALS AND METHODS: Version 2 of FACT-L, with 43 questions in 6 subscale categories (8 physical well-being, 8 social/family well-being, 3 relationship with doctor, 6 emotional well-being, 8 functional well-being, 10 lung cancer symptoms), available in English, Spanish and French, was administered by data managers and filled out by pts, independent of physician presence or input. The HART trial enrolled 30 pts, and FACT-L was administered at baseline (tp 1), treatment completion (tp 2) and 4 weeks following therapy (tp 3). (35(43)) FACT-L items were designed to yield a total QOL score with higher values reflective of better QOL; in addition, a FACT-L trial outcome index (TOI) was computed (TOI = physical score + functional score + lung cancer related score), and is considered the most relevant clinical QOL measure. RESULTS: The FACT-L completion rates were: tp 1 - (30(30)) (100%), tp 2 - (29(30)) (97%) and tp 3 - (24(30)) (80%); the mean scores at various time points are summarized in the table below and indicate that FACT-L is responsive to changes over time. The differences in subscales and total scores can be used as a measure of change in QOL resulting from treatment; statistically significant change was noted from baseline to tp 2 for physical, emotional and functional well-being; and from baseline to tp 3 for emotional well-being. The change in TOI score was also evaluated as a function of response and toxicity grade, and no clear association emerged. When assessed as a function of survival (at the time of this analysis, (5(30)) pt were alive, with median survival of 56 weeks), the degradation in QOL was most severe for pt who died early; the mean change in TOI from baseline to tp 3 for pt dying in the first 25 weeks, 25

  8. Noncovalent functionalization of pristine CVD single-walled carbon nanotubes with 3d metal(II) phthalocyanines by adsorption from the gas phase

    Science.gov (United States)

    Basiuk, Vladimir A.; Flores-Sánchez, Laura J.; Meza-Laguna, Victor; Flores-Flores, José Ocotlán; Bucio-Galindo, Lauro; Puente-Lee, Iván; Basiuk, Elena V.

    2018-04-01

    Noncovalent hybrids of carbon nanotubes (CNTs) with phthalocyanines (Pcs) is a subject of growing research effort focused on the development of new efficient organic photovoltaic cells, heterogeneous catalysts, lithium batteries, gas sensors, field effect transistors, among other possible applications. The main advantage of using unsubstituted Pcs is their very moderate cost and easy commercial availability. Unfortunately, the deposition of unsubstituted Pcs onto CNT sidewalls via the traditional liquid-phase strategy proves to be very problematic due to an extremely poor solubility of Pcs. At the same time, unsubstituted free-base H2Pc ligand and many of its transition metal complexes exhibit high thermal stability and volatility under reduced pressure, which allows for their physical vapor deposition onto solid surfaces. In the present work, we demonstrated the possibility of simple, fast, efficient and environmentally friendly noncovalent functionalization of single-walled CNTs (SWNTs) with a series of 3d metal(II) phthalocyanines Me(II)Pc, where Me = Co, Ni, Cu and Zn. The functionalization can be performed at 400-500 °C under moderate vacuum, and takes about 2-3 h only. The nanohybrids obtained were characterized by means of Fourier-transform infrared, Raman, UV-vis and energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), scanning and transmission electron microscopy. TGA suggested that Pc weight content is 30%, 17% and 35% for NiPc, CuPc and ZnPc, respectively (CoPc exhibited anomalous behavior), which is close to the estimates from EDS spectra of 24-39%, 27-36% and 27-44% for CoPc, CuPc and ZnPc, respectively. A strong increase in intensity of D band in the Raman spectra of SWNT‒Pc hybrids, as compared to that of pristine nanotubes, was interpreted as very strong interactions between Pc molecules and SWNT sidewalls. Very high absolute values of binding energies of 32.46-37.12 kcal/mol and the patterns of HOMO and LUMO distribution

  9. Tracking Sodium-Antimonide Phase Transformations in Sodium-Ion Anodes: Insights from Operando Pair Distribution Function Analysis and Solid-State NMR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Allan, Phoebe K. [University of Cambridge, University Chemical Laboratory, Lensfield Road, Cambridge, CB2 1EW, U.K.; Gonville and Caius College, Trinity; Griffin, John M. [University of Cambridge, University Chemical Laboratory, Lensfield Road, Cambridge, CB2 1EW, U.K.; Darwiche, Ali [Institut; Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France; Borkiewicz, Olaf J. [X-ray; Wiaderek, Kamila M. [X-ray; Chapman, Karena W. [X-ray; Morris, Andrew J. [Theory of; Chupas, Peter J. [X-ray; Monconduit, Laure [Institut; Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France; Grey, Clare P. [University of Cambridge, University Chemical Laboratory, Lensfield Road, Cambridge, CB2 1EW, U.K.

    2016-02-15

    Operando pair distribution function (PDF) analysis and ex situ Na-23 magic-angle spinning solid-state nuclear magnetic resonance (MAS ssNMR) spectroscopy are used to gain insight into the alloying mechanism of high-capacity antimony anodes for sodium-ion batteries. Subtraction of the PDF of crystalline NaxSb phases from the total PDF, an approach constrained by chemical phase information gained from Na-23 ssNMR in reference to relevant model compounds, identifies two previously uncharacterized intermediate species formed electro-chemically; a-Na3-xSb (x approximate to 0.4-0.5), a structure locally similar to crystalline Na3Sb (c-Na3Sb) but with significant numbers of sodium vacancies and a limited correlation length, and a-Na1.7Sb, a highly amorphous structure featuring some Sb-Sb bonding. The first sodiation breaks down the crystalline antimony to form first a-Na3-xSb and, finally, crystalline Na3Sb. Desodiation results in the formation of an electrode formed of a composite of crystalline and amorphous antimony networks. We link the different reactivity of these networks to a series of sequential sodiation reactions manifesting as a cascade of processes observed in the electrochemical profile of subsequent cycles. The amorphofis network reacts at higher voltages reforming a-Na1.7Sb, then a-Na3-xSb, whereas lower potentials are required for the sodiation of crystalline antimony, which reacts to form a-Na3-xSb without the formation of a-Na3-xSb. a-Na3-xSb is converted to crystalline Na3Sb at the end of the second discharge. We find no evidence of formation of NaSb. Variable temperature Na-23 NMR experiments reveal significant sodium mobility within c-Na3Sb; this is a possible contributing factor to the excellent rate performance of Sb anodes.

  10. A porous carbon derived from amino-functionalized material of Institut Lavoisier as a solid-phase microextraction fiber coating for the extraction of phthalate esters from tea.

    Science.gov (United States)

    Liang, Weiqian; Wang, Juntao; Zang, Xiaohuan; Wang, Chun; Wang, Zhi

    2016-04-01

    In this work, a porous carbon derived from amino-functionalized material of Institut Lavoisier (C-NH2 -MIL-125) was prepared and coated onto a stainless-steel wire through sol-gel technique. The coated fiber was used for the solid-phase microextraction of trace levels of phthalate esters (diallyl phthalate, di-iso-butyl ortho-phthalate, di-n-butyl ortho-phthalate, benzyl-n-butyl ortho-phthalate, and bis(2-ethylhexy) ortho-phthalate) from tea beverage samples before gas chromatography with mass spectrometric analysis. Several experimental parameters that could influence the extraction efficiency such as extraction time, extraction temperature, sample pH, sample salinity, stirring rate, desorption temperature and desorption time, were investigated. Under the optimal conditions, the linearity existed in the range of 0.05-30.00 μg/L for green jasmine tea beverage samples, and 0.10-30.00 μg/L for honey jasmine tea beverage samples, with the correlation coefficients (r) ranging from 0.9939 to 0.9981. The limits of detection of the analytes for the method were 2.0-3.0 ng/L for green jasmine tea beverage sample, and 4.0-5.0 ng/L for honey jasmine tea beverage sample, depending on the compounds. The recoveries of the analytes for the spiked samples were in the range of 82.0-106.0%, and the precision, expressed as the relative standard deviations, was less than 11.1%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Preparation of p-tert[(dimethylamino)methyl]-calix[4]arene functionalized aminopropylpolysiloxane resin for selective solid-phase extraction and preconcentration of metal ions.

    Science.gov (United States)

    Nie, Rong; Chang, Xijun; He, Qun; Hu, Zheng; Li, Zhenhua

    2009-09-30

    A new p-tert-[(dimethylamino)methyl]-1,3-bisglyciyl-calix[4]arene functionalized aminopropylpolysiloxane resin (APPS-CA) has been prepared and investigated for selective solid-phase extraction (SPE) of trace Cr (III), Cu (II), Ni (II), Co (II) and Zn (II) prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The characterization of the surface modification was performed on the basis of FT-IR spectroscopy, elemental analysis and thermal gravimetric analysis. The separation/preconcentration conditions of analytes were investigated, including effect of pH, the shaking time, the sample flow rate and volume, the elution condition, the interfering ions and stability test. At pH 4.0, the maximum adsorption capacity of Cr (III), Cu (II), Ni (II), Co (II) and Zn (II) were 47.2, 34.3, 52.8, 29.8 and 36.4 mg g(-1), respectively. The adsorbed metal ions were quantitatively eluted by 2.0 mL of 0.5 mol L(-1) HCl. Common coexisting ions did not interfere with the separation. According to the definition of International Union of Pure and Applied Chemistry, the detection limits (3 sigma) of this method were found to be 0.58, 0.33, 0.47, 0.61 and 0.14 ng mL(-1) for Cr (III), Cu (II), Ni (II), Co (II) and Zn (II), respectively. The relative standard deviation under optimum conditions is less than 4.0%. The application of this new adsorbent to preconcentration trace Cr (III), Cu (II), Ni (II), Co (II) and Zn (II) of two water samples gave high accurate and precise results.

  12. Metastable and equilibrium phase diagrams of unconjugated bilirubin IXα as functions of pH in model bile systems: Implications for pigment gallstone formation.

    Science.gov (United States)

    Berman, Marvin D; Carey, Martin C

    2015-01-01

    Metastable and equilibrium phase diagrams for unconjugated bilirubin IXα (UCB) in bile are yet to be determined for understanding the physical chemistry of pigment gallstone formation. Also, UCB is a molecule of considerable biomedical importance because it is a potent antioxidant and an inhibitor of atherogenesis. We employed principally a titrimetric approach to obtain metastable and equilibrium UCB solubilities in model bile systems composed of taurine-conjugated bile salts, egg yolk lecithin (mixed long-chain phosphatidylcholines), and cholesterol as functions of total lipid concentration, biliary pH values, and CaCl2 plus NaCl concentrations. Metastable and equilibrium precipitation pH values were obtained, and average pKa values of the two carboxyl groups of UCB were calculated. Added lecithin and increased temperature decreased UCB solubility markedly, whereas increases in bile salt concentrations and molar levels of urea augmented solubility. A wide range of NaCl and cholesterol concentrations resulted in no specific effects, whereas added CaCl2 produced large decreases in UCB solubilities at alkaline pH values only. UV-visible absorption spectra were consistent with both hydrophobic and hydrophilic interactions between UCB and bile salts that were strongly influenced by pH. Reliable literature values for UCB compositions of native gallbladder biles revealed that biles from hemolytic mice and humans with black pigment gallstones are markedly supersaturated with UCB and exhibit more acidic pH values, whereas biles from nonstone control animals and patients with cholesterol gallstone are unsaturated with UCB. Copyright © 2015 the American Physiological Society.

  13. Resting-state functional connectivity changes within the default mode network and the salience network after antipsychotic treatment in early-phase schizophrenia

    Directory of Open Access Journals (Sweden)

    Wang Y

    2017-02-01

    Full Text Available Yingchan Wang,1 Weijun Tang,2 Xiaoduo Fan,3 Jianye Zhang,1 Daoying Geng,2 Kaida Jiang,1 Dianming Zhu,1 Zhenhua Song,1 Zeping Xiao,1 Dengtang Liu1 1First-Episode Schizophrenia and Early Psychosis Program, Division of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, 2Department of Radiology, Huashan Hospital, Fu Dan University, Shanghai, People’s Republic of China; 3Psychotic Disorders Program, UMass Memorial Medical Center, UMass Medical School, Worcester, MA, USA Objective: Abnormal resting-state functional connectivity (FC, particularly in the default mode network (DMN and the salience network (SN, has been reported in schizophrenia, but little is known about the effects of antipsychotics on these networks. The purpose of this study was to examine the effects of atypical antipsychotics on DMN and SN and the relationship between these effects and symptom improvement in patients with schizophrenia.Methods: This was a prospective study of 33 patients diagnosed with schizophrenia and treated with antipsychotics at Shanghai Mental Health Center. Thirty-three healthy controls matched for age and gender were recruited. All subjects underwent functional magnetic resonance imaging (fMRI. Healthy controls were scanned only once; patients were scanned before and after 6–8 weeks of treatment.Results: In the DMN, the patients exhibited increased FC after treatment in the right superior temporal gyrus, right medial frontal gyrus, and left superior frontal gyrus and decreased FC in the right posterior cingulate/precuneus (P<0.005. In the SN, the patients exhibited decreased FC in the right cerebellum anterior lobe and left insula (P<0.005. The FC in the right posterior cingulate/precuneus in the DMN negatively correlated with the difference between the Clinical Global Impression (CGI score pre/post-treatment (r=–0.564, P=0.023 and negative trends with the difference in the Positive and Negative

  14. Structure and optical function of amorphous photonic nanostructures from avian feather barbs: a comparative small angle X-ray scattering (SAXS) analysis of 230 bird species.

    Science.gov (United States)

    Saranathan, Vinodkumar; Forster, Jason D; Noh, Heeso; Liew, Seng-Fatt; Mochrie, Simon G J; Cao, Hui; Dufresne, Eric R; Prum, Richard O

    2012-10-07

    Non-iridescent structural colours of feathers are a diverse and an important part of the phenotype of many birds. These colours are generally produced by three-dimensional, amorphous (or quasi-ordered) spongy β-keratin and air nanostructures found in the medullary cells of feather barbs. Two main classes of three-dimensional barb nanostructures are known, characterized by a tortuous network of air channels or a close packing of spheroidal air cavities. Using synchrotron small angle X-ray scattering (SAXS) and optical spectrophotometry, we characterized the nanostructure and optical function of 297 distinctly coloured feathers from 230 species belonging to 163 genera in 51 avian families. The SAXS data provided quantitative diagnoses of the channel- and sphere-type nanostructures, and confirmed the presence of a predominant, isotropic length scale of variation in refractive index that produces strong reinforcement of a narrow band of scattered wavelengths. The SAXS structural data identified a new class of rudimentary or weakly nanostructured feathers responsible for slate-grey, and blue-grey structural colours. SAXS structural data provided good predictions of the single-scattering peak of the optical reflectance of the feathers. The SAXS structural measurements of channel- and sphere-type nanostructures are also similar to experimental scattering data from synthetic soft matter systems that self-assemble by phase separation. These results further support the hypothesis that colour-producing protein and air nanostructures in feather barbs are probably self-assembled by arrested phase separation of polymerizing β-keratin from the cytoplasm of medullary cells. Such avian amorphous photonic nanostructures with isotropic optical properties may provide biomimetic inspiration for photonic technology.

  15. Modeling of Large-Scale Functional Brain Networks Based on Structural Connectivity from DTI: Comparison with EEG Derived Phase Coupling Networks and Evaluation of Alternative Methods along the Modeling Path.

    Directory of Open Access Journals (Sweden)

    Holger Finger

    2016-08-01

    Full Text Available In this study, we investigate if phase-locking of fast oscillatory activity relies on the anatomical skeleton and if simple computational models informed by structural connectivity can help further to explain missing links in the structure-function relationship. We use diffusion tensor imaging data and alpha band-limited EEG signal recorded in a group of healthy individuals. Our results show that about 23.4% of the variance in empirical networks of resting-state functional connectivity is explained by the underlying white matter architecture. Simulating functional connectivity using a simple computational model based on the structural connectivity can increase the match to 45.4%. In a second step, we use our modeling framework to explore several technical alternatives along the modeling path. First, we find that an augmentation of homotopic connections in the structural connectivity matrix improves the link to functional connectivity while a correction for fiber distance slightly decreases the performance of the model. Second, a more complex computational model based on Kuramoto oscillators leads to a slight improvement of the model fit. Third, we show that the comparison of modeled and empirical functional connectivity at source level is much more specific for the underlying structural connectivity. However, different source reconstruction algorithms gave comparable results. Of note, as the fourth finding, the model fit was much better if zero-phase lag components were preserved in the empirical functional connectome, indicating a considerable amount of functionally relevant synchrony taking place with near zero or zero-phase lag. The combination of the best performing alternatives at each stage in the pipeline results in a model that explains 54.4% of the variance in the empirical EEG functional connectivity. Our study shows that large-scale brain circuits of fast neural network synchrony strongly rely upon the structural connectome and simple

  16. Moon Phases

    Science.gov (United States)

    Riddle, Bob

    2010-01-01

    When teaching Moon phases, the focus seems to be on the sequence of Moon phases and, in some grade levels, how Moon phases occur. Either focus can sometimes be a challenge, especially without the use of models and observations of the Moon. In this month's column, the author describes some of the lessons that he uses to teach the phases of the Moon…

  17. Extraction and preconcentration of tylosin from milk samples through functionalized TiO₂ nanoparticles reinforced with a hollow fiber membrane as a novel solid/liquid-phase microextraction technique.

    Science.gov (United States)

    Sehati, Negar; Dalali, Nasser; Soltanpour, Shahla; Dorraji, Mir Saeed Seyed

    2014-08-01

    The aim of this study was to introduce a novel, simple, and highly sensitive preparation method for determination of tylosin in different milk samples. In the so-called functionalized TiO2 hollow fiber solid/liquid-phase microextraction method, the acceptor phase is functionalized TiO2 nanoparticles that are dispersed in the organic solvent and held in the pores and lumen of a porous polypropylene hollow fiber membrane. An effective functionalization of TiO2 nanoparticles has been done in the presence of aqueous H2 O2 and a mild acidic ambient under UV irradiation. This novel extraction method showed excellent extraction efficiency and a high enrichment factor (540.2) in comparison with conventional hollow fiber liquid-phase microextraction. All the experiments were monitored at λmax = 284 nm using a simple double beam UV-visible spectrophotometer. A Taguchi orthogonal array experimental design with an OA16 (4(5) ) matrix was employed to optimize the factors affecting the efficiency of hollow fiber solid/liquid-phase microextraction such as pH, stirring rate, salt addition, extraction time, and the volume of donor phase. This developed method was successfully applied for the separation and determination of tylosin in milk samples with a linear concentration range of 0.51-7000 μg/L (r(2) = 0.991) and 0.21 μg/L as the limit of detection. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Phase Field

    Science.gov (United States)

    Koyama, Toshiyuki

    The term phase field has recently become known across many fields of materials science. The meaning of phase field is the spatial and temporal order parameter field defined in a continuum-diffused interface model. By using the phase field order parameters, many types of complex microstructure changes observed in materials science are described effectively. This methodology has been referred to as the phase field method, phase field simulation, phase field modeling, phase field approach, etc. In this chapter, the basic concept and theoretical background for the phase field approach is explained in Sects. 21.1 and 21.2. The overview of recent applications of the phase field method is demonstrated in Sects. 21.3 to 21.6.

  19. The relationship of neurocognition and negative symptoms to social and role functioning over time in individuals at clinical high risk in the first phase of the North American Prodrome Longitudinal Study.

    Science.gov (United States)

    Meyer, Eric C; Carrión, Ricardo E; Cornblatt, Barbara A; Addington, Jean; Cadenhead, Kristin S; Cannon, Tyrone D; McGlashan, Thomas H; Perkins, Diana O; Tsuang, Ming T; Walker, Elaine F; Woods, Scott W; Heinssen, Robert; Seidman, Larry J

    2014-11-01

    Impaired social, role, and neurocognitive functioning are preillness characteristics of people who later develop psychosis. In people with schizophrenia, neurocognition and negative symptoms are associated with functional impairment. We examined the relative contributions of neurocognition and symptoms to social and role functioning over time in clinically high-risk (CHR) individuals and determined if negative symptoms mediated the influence of cognition on functioning. Social, role, and neurocognitive functioning and positive, negative, and disorganized symptoms were assessed in 167 individuals at CHR for psychosis in the North American Prodrome Longitudinal Study Phase 1 (NAPLS-1), of whom 96 were reassessed at 12 months. Regression analyses indicated that negative symptoms accounted for unique variance in social and role functioning at baseline and follow-up. Composite neurocognition accounted for unique, but modest, variance in social and role functioning at baseline and in role functioning at follow-up. Negative symptoms mediated the relationship between composite neurocognition and social and role functioning across time points. In exploratory analyses, individual tests (IQ estimate, Digit Symbol/Coding, verbal memory) selectively accounted for social and role functioning at baseline and follow-up after accounting for symptoms. When negative symptom items with content overlapping with social and role functioning measures were removed, the relationship between neurocognition and social and role functioning was strengthened. The modest overlap among neurocognition, negative symptoms, and social and role functioning indicates that these domains make substantially separate contributions to CHR individuals. © The Author 2014. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. Investigating the evolution of the phase behavior of AOT-based w/o microemulsions in dodecane as a function of droplet volume fraction.

    Science.gov (United States)

    Ganguly, R; Choudhury, N

    2012-04-15

    AOT-based water in oil (w/o) microemulsions are one of the most extensively studied reverse micellar systems because of their rich phase behavior and their ability to form in the absence of any co-surfactant. The aggregation characteristics and interaction of the microemulsion droplets in these systems are known to be governed by AOT-oil compatibility and water to AOT molar ratio (w). In this manuscript by using Dynamic Light Scattering (DLS) and viscometry techniques, we show that droplet volume fraction too plays an important role in shaping the phase behavior of these microemulsions in dodecane. The phase separation characteristics and the evolution of the viscosity and the hydrodynamic radius of the microemulsion droplets on approaching the cloud points have thus been found to undergo complete transformation as one goes from low to high droplet volume fraction even at a fixed 'w'. Modeling of the DLS data attributes this to the weakening of inter droplet attractive interaction caused by the growing dominance of the excluded volume effect with increase in droplet volume fraction. In the literature, the inter droplet attractive interaction driven phase separation in these microemulsions is explained based on gas-liquid type phase transition, conceptualized in the framework of Baxter adhesive hard sphere theory. The modeling of our viscosity data, however, does not support such proposition as the characteristic stickiness parameter (τ(-1)) of the microemulsion droplets in this system remains much lower than the critical value (τ(c)(-1)≈10.25) required to enforce such phase transition. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Flexible and re-configurable optical three-input XOR logic gate of phase-modulated signals with multicast functionality for potential application in optical physical-layer network coding.

    Science.gov (United States)

    Lu, Guo-Wei; Qin, Jun; Wang, Hongxiang; Ji, XuYuefeng; Sharif, Gazi Mohammad; Yamaguchi, Shigeru

    2016-02-08

    Optical logic gate, especially exclusive-or (XOR) gate, plays important role in accomplishing photonic computing and various network functionalities in future optical networks. On the other hand, optical multicast is another indispensable functionality to efficiently deliver information in optical networks. In this paper, for the first time, we propose and experimentally demonstrate a flexible optical three-input XOR gate scheme for multiple input phase-modulated signals with a 1-to-2 multicast functionality for each XOR operation using four-wave mixing (FWM) effect in single piece of highly-nonlinear fiber (HNLF). Through FWM in HNLF, all of the possible XOR operations among input signals could be simultaneously realized by sharing a single piece of HNLF. By selecting the obtained XOR components using a followed wavelength selective component, the number of XOR gates and the participant light in XOR operations could be flexibly configured. The re-configurability of the proposed XOR gate and the function integration of the optical logic gate and multicast in single device offer the flexibility in network design and improve the network efficiency. We experimentally demonstrate flexible 3-input XOR gate for four 10-Gbaud binary phase-shift keying signals with a multicast scale of 2. Error-free operations for the obtained XOR results are achieved. Potential application of the integrated XOR and multicast function in network coding is also discussed.

  2. Experimental study of the positive leader velocity as a function of the current in the initial and final-jump phases of a spark discharge

    International Nuclear Information System (INIS)

    Andreev, A. G.; Bazelyan, E. M.; Bulatov, M. U.; Kuzhekin, I. P.; Makalsky, L. M.; Sukharevskij, D. I.; Syssoev, V. S.

    2008-01-01

    A positive leader in air at gap lengths of up to 8 m was studied experimentally on an open experimental stand. The voltage source was a 6-MV pulsed voltage generator or an artificial charged aerosol cloud. The dependence of the leader velocity on the current in the range 0.2-8 A was determined by simultaneously recording the optical picture and electric parameters of the discharge. Particular attention was paid to the final-jump phase of the discharge, when the gap was completely bridged by the streamer zone of the leader. It is shown that the character of the dependence of the leader velocity on the current in this phase remains unchanged; hence, the final-jump phase can be used in experiments in which the current has to be varied within a wide range. For this purpose, one can use a damping resistance, which is inefficient in the initial phase. The parameters of the power-law dependence of the leader velocity on the current at currents of a few amperes are established reliably. It is found that the power-law dependence with constant parameters is inapplicable to calculate the leader velocity at currents of about 0.1 A, which correspond to the lower limit of the leader viability.

  3. Functions of Saccharomyces cerevisiae Ecm27p, a putative Na(+)/Ca(2+) exchanger, in calcium homeostasis, carbohydrate storage and cell cycle reentry from the quiescent phase.

    Science.gov (United States)

    Klukovich, Rachel; Courchesne, William E

    2016-01-01

    The quiescent phase of the cell cycle is of fundamental importance for fungi, yet our understanding of this phase of the cycle is much less well understood than the mitotic cell cycle. We found that the ECM27 gene, which encodes a Na(+)/Ca(2+) exchanger, is responsible for influx of calcium from the extracellular space and release from intracellular stores during membrane stress. Wild type cells increase total Ca(2+) in quiescence but cells lacking ECM27 gene fail to do so and are defective in cell cycle reentry from the quiescent phase. ecm27Δ cells are also defective in maintaining trehalose levels throughout this phase. Addition of high levels of CaCl2 to the growth medium can increase total cellular calcium in ecm27Δ cells during quiescence and can also restore trehalose levels as well as partially restore ability of cells to reenter the mitotic cell cycle. ecm27Δ cells also have altered glycogen levels in exponentially growing cells. Our results show that Ecm27p and Ca(2+) play roles in maintaining a high level of trehalose in quiescent cells, which in turn is important in the ability of cells to rapidly return to proliferation. Copyright © 2016 Elsevier GmbH. All rights reserved.

  4. Gas-conditioning and fuelling installation for low-quantity biogas production - Phase II: construction and operation of a functional model; Aufbereitungs- und Betankungsanlage fuer kleinere Biogasproduktionsmengen. Phase II: Bau und Betrieb eines Funktionsmusters - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Oester, U.

    2009-12-15

    This final report for the Swiss Federal Office of Energy (SFOE) describes and discusses the construction and operation of a functional model for gas-conditioning and fuelling for biogas produced in small installations with methane content of around 55%. In normal natural gas mains the methane content is quoted at 80% to 90%. Large biogas treatment installations are designed for 100 m{sup 3}/h and are regarded by the author as being too expensive for small installations. The development and functioning of a functional model for the removal of carbon dioxide is described and the results obtained are presented and discussed. Work still to be done to increase the amount of CO{sub 2} extracted is discussed. Also economic feasibility and information topics are discussed.

  5. Functional tests of 2S modules for the CMS Phase-2 Tracker Upgrade with a MicroTCA-based readout system

    CERN Document Server

    Preuten, Marius; Klein, Katja; Lipinski, Martin; Rauch, Max; Feld, Lutz

    2017-01-01

    First full size 2S module prototypes for the CMS Phase-2 Outer Tracker Upgrade have been assembled. With two sensors of realistic dimensions and 16 CBC2 readout ASICs on two front-end hybrids, the characteristics of these novel and complex objects can be studied.A MicroTCA based readout system was developed to test multiple front-end hybrids simultaneously. Therefore the concurrent information of the full module can be used for noise and signal studies.

  6. Coping styles within the family system in the chronic phase following acquired brain injury: its relation to families' and patients' functioning.

    Science.gov (United States)

    Wolters Gregório, Gisela; Stapert, Sven; Brands, Ingrid; van Heugten, Caroline

    2011-02-01

    To investigate how the functioning of family members and the coping styles they use are related to the psychosocial functioning both of the family members and of the person who has sustained a brain injury. Cross-sectional study. Primary caregivers (n = 61) and other family members (n = 15) of 61 patients with brain injury. Primary caregivers completed the Utrecht Coping List, the Life Satisfaction Questionnaire 9, and the Caregiver Strain Index. All family members completed the Family Assessment Device. Data for the patients were collected retrospectively. Primary caregivers who had a preference for passive coping styles reported that they experienced a lower level of family functioning, a lower quality of life, and a higher strain. Neither the coping styles nor the psychosocial outcomes of the primary caregivers were significantly associated with patients' self-reported quality of life. Furthermore, there was no correlation between the level of family functioning and a patient's quality of life. Coping styles of caregivers are important determinants for their own psychosocial functioning, but not for patients' psychosocial functioning, although causality cannot be inferred. To enhance caregivers' psychosocial functioning, rehabilitation should focus on changing their coping styles into ones that are less passive. Furthermore, distinct or additional interventions may be needed to change the patient's coping style.

  7. On the Existence of Non-Oscillatory Phase Functions for Second Order Ordinary Differential Equations in the High-Frequency Regime

    Science.gov (United States)

    2014-08-04

    L2 pRq and ensures the convergence of the improper Riemann integrals (140). 7. Fourier estimate In this section, we derive a pointwise estimate on...improper Riemann integral . If, however, we assume the function p appearing in (122) is an element of L1 pRq and impose the hypotheses of Theorem 18 on the...decomposed as the sum of a nonoscillatory function h0 and a highly oscillatory function h1 of small magnitude. However, the solution of (15) is actually

  8. Acute phase reaction and acute phase proteins*

    Science.gov (United States)

    Gruys, E.; Toussaint, M.J.M.; Niewold, T.A.; Koopmans, S.J.

    2005-01-01

    A review of the systemic acute phase reaction with major cytokines involved, and the hepatic metabolic changes, negative and positive acute phase proteins (APPs) with function and associated pathology is given. It appears that APPs represent appropriate analytes for assessment of animal health. Whereas they represent non-specific markers as biological effect reactants, they can be used for assessing nutritional deficits and reactive processes, especially when positive and negative acute phase variables are combined in an index. When such acute phase index is applied to separate healthy animals from animals with some disease, much better results are obtained than with single analytes and statistically acceptable results for culling individual animals may be reached. Unfortunately at present no cheap, comprehensive and easy to use system is available for assessing various acute phase proteins in serum or blood samples at the same time. Protein microarray or fluid phase microchip technology may satisfy this need; and permit simultaneous analysis of numerous analytes in the same small volume sample and enable integration of information derived from systemic reactivity and nutrition with disease specific variables. Applying such technology may help to solve health problems in various countries not only in animal husbandry but also in human populations. PMID:16252337

  9. Functionalized SBA-15 supported nickel (II)–oxime–imine catalysts for liquid phase oxidation of olefins under solvent-free conditions

    International Nuclear Information System (INIS)

    Paul, Luna; Banerjee, Biplab; Bhaumik, Asim; Ali, Mahammad

    2016-01-01

    A new oxime–imine functionalized highly ordered mesoporous SBA-15 (SBA-15-NH 2 -DAMO) has been synthesized via post-synthesis functionalization of SBA-15 with 3-aminopropyl-triethoxysilane followed by the Schiff base condensation with diacetylmonooxime, which was further reacted with Ni(ClO 4 ) 2 to yield the functionalized nickel catalyst SBA-15-NH 2 -DAMO-Ni. All the synthesized materials were thoroughly characterized using different characterization techniques. It was found that SBA-15-NH 2 -DAMO-Ni catalyzes the one-pot oxidation of olefins like styrene, cyclohexene, cyclooctene, 1-hexene and 1-octene to the corresponding benzaldehyde, cyclohexene-1-ol and cyclooctene-oxide, respectively under solvent-free conditions by using tert-butylhydroperoxide as oxidant. - Graphical abstract: A new well characterized oxime–imine functionalized highly ordered mesoporous SBA-15-NH 2 -DAMO-Ni complex catalyzes the one-pot oxidation of olefins under solvent free mild conditions.

  10. Functionalized Nano-Film Microchannel Plate: A Single High Aspect Ratio Device for High Resolution, Low Noise Astronomical Imaging, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Atomic layer deposited functional nano-film technology is used to manufacture Microchannel plate (MCP) devices capable of high gain / low ion feedback operation, on...

  11. Functionalized polymer-based spherical activated carbon for liquid and gas phase applications; Funktionalisierte polymerbasierte sphaerische Aktivkohle fuer Fluessig- und Gasphasenanwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Schrage, Christian; Modrow, Antje; Fichtner, Sven; Giebelhausen, Jann Michael [Bluecher GmbH, Premnitz (Germany); Boehringer, Bertram [Bluecher GmbH, Erkrath (Germany)

    2014-02-15

    Polymer-based spherical activated carbon (PBSAC) can be functionalized through the integration of reactive compounds. This offers new fields of applications for this adsorbent material. Impregnated PBSAC can be used as broadband sorbent material for respiratory protection, and for removal of certain metals from water, while the integration of nitrogen leads to a material suitable for the clean-up of gases. Functionalization through oxidation or integration of nitrogen atoms enables the concentration of valuable resources like uranium or gold.

  12. Virtual reality exercise on a home-based phase III cardiac rehabilitation program, effect on executive function, quality of life and depression, anxiety and stress: a randomized controlled trial.

    Science.gov (United States)

    Vieira, Ágata; Melo, Cristina; Machado, Jorge; Gabriel, Joaquim

    2018-02-01

    To analyse the effect of a six-month home-based phase III cardiac rehabilitation (CR) specific exercise program, performed in a virtual reality (Kinect) or conventional (booklet) environment, on executive function, quality of life and depression, anxiety and stress of subjects with coronary artery disease. A randomized controlled trial was conducted with subjects, who had completed phase II, randomly assigned to intervention group 1 (IG1), whose program encompassed the use of Kinect (n = 11); or intervention group 2 (IG2), a paper booklet (n = 11); or a control group (CG), only subjected to the usual care (n = 11). The three groups received education on cardiovascular risk factors. The assessed parameters, at baseline (M0), 3 (M1) and 6 months (M2), were executive function, control and integration in the implementation of an adequate behaviour in relation to a certain objective, specifically the ability to switch information (Trail Making Test), working memory (Verbal Digit Span test), and selective attention and conflict resolution ability (Stroop test), quality of life (MacNew questionnaire) and depression, anxiety and stress (Depression, Anxiety and Stress Scale 21). Descriptive and inferential statistical measures were used, significance level was set at .05. The IG1 revealed significant improvements, in the selective attention and conflict resolution ability, in comparison with the CG in the variable difference M0 - M2 (p = .021) and in comparison with the IG2 in the variable difference M1 - M2 and M0 - M2 (p = .001 and p = .002, respectively). No significant differences were found in the quality of life, and depression, anxiety and stress. The virtual reality format had improved selective attention and conflict resolution ability, revealing the potential of CR, specifically with virtual reality exercise, on executive function. Implications for Rehabilitation In cardiac rehabilitation, especially in phase III, it is

  13. Two-stage pressure-induced Yb valence change in the hexagonal Laves phase YbAg2: Investigation by time differential perturbed angular γ -γ correlation spectroscopy method and density functional calculations

    Science.gov (United States)

    Tsvyashchenko, A. V.; Nikolaev, A. V.; Salamatin, D. A.; Velichkov, A.; Salamatin, A. V.; Novikov, A. P.; Fomicheva, L. N.; El'kin, F. S.; Bibikov, A. V.; Kozin, M. G.; Budzynski, M.

    2017-12-01

    We have studied the C14 hexagonal Laves phase of YbAg2 at normal conditions and under external pressure up to 19 GPa by the time-differential perturbed angular γ -γ correlation spectroscopy (TDPAC) using 111Cd probe nuclei. Under pressure the valence of Yb undergoes a two-stage transition from 2.8 to 3. The two-stage scenario is characterized by two distinct quadrupole frequencies of 111Cd probes in a silver sublattice, monotonically increasing with pressure and saturating at 8 and 16 GPa. Our experimental data are compared with the density functional studies of the electron band structure of YbAg2, whose results are used for discussion and interpretation of these experiments. We have found that there are two different electric field gradients at inequivalent silver sites and that 4 d states of silver participate in metal bonding, allowing for the formation of the hexagonal Laves phase.

  14. Climate Management System for mushroom cultivation (CMMC). First phase. Inventory and functional design; Klimaat Managementsysteem Champignonteelt (KMC). 1e fase. Inventarisatie en functioneel ontwerp

    Energy Technology Data Exchange (ETDEWEB)

    Gielen, J.H. [DLV Plant, Horst (Netherlands)

    2011-03-15

    This report describes the feasibility and the opportunities of developing a Climate Management System for Mushroom Cultivation (CMMC) software package, based on which a decision can be made to proceed with the realization of phase 2 of the project, i.e. the actual construction of the CMMC for mushroom cultivation [Dutch] Deze rapportage beschrijft de haalbaarheid en de mogelijkheden van de ontwikkeling van een KMC software pakket, op basis waarvan besloten kan worden tot de realisatie van fase 2 van het project, de daadwerkelijke bouw van de KMC voor de champignonteelt.

  15. The evolution of granule fracture strength as a function of impeller tip speed and granule size for a novel reverse-phase wet granulation process.

    Science.gov (United States)

    Wade, J B; Martin, G P; Long, D F

    2015-07-05

    The feasibility of a novel reverse-phase wet granulation process has been established previously and several potential advantages over the conventional process have been highlighted (Wade et al., 2014a,b,b). Due to fundamental differences in the growth mechanism and granule consolidation behaviour between the two processes the reverse-phase approach generally formed granules with a greater mass mean diameter and a lower intragranular porosity than those formed by the conventional granulation process under the same liquid saturation and impeller tip speed conditions. The lower intragranular porosity was hypothesised to result in an increase in the granule strength and subsequent decrease in tablet tensile strength. Consequently, the aim of this study was to compare the effect of impeller tip speed and granule size on the strength and compaction properties of granules prepared using both the reverse-phase and conventional granulation processes. For the conventional granulation process an increase in the impeller tip speed from 1.57 to 4.71 ms(-1) (200-600 RPM) resulted in an increase in the mean granule strength (pgranule size fractions and as the granule size fraction increased from 425-600 to 2000-3350 μm the mean fracture strength decreased (p0.05) on mean granule strength whereas, like the conventional process, an increase in granule size fraction from 425-600 to 2000-3350 μm resulted in a decrease (pgranule fracture strength and the tablet tensile strength (p>0.05) for either granulation approach. These data support the rejection of the original hypothesis which stated that an increase in granule strength may result in a decrease in the tablet tensile strength. The similar tablet tensile strength observed between the conventional and reverse-phase granulation processes indicated that while mechanistic differences exist in the formation of the granules, which resulted in significant granule-scale fracture strength differences, the granule compaction properties

  16. Three-phase power load flow with uncertainty modeling via sinusoidal membership function; Fluxo de carga trifasico com modelagem de incertezas via funcao de pertinencia sinusoidal

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcante, Patricia L.; Murari, Carlos Alberto F.; Salas, Silvio S. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Engenharia Eletrica e de Computacao], Emails: plc@dsee.fee.unicamp.br, murari@dsee.fee.unicamp.br, ssegura@dsee.fee.unicamp.br

    2009-07-01

    During the development of models for power systems, the researchers aim always to get results compatible with reality, and in this research it was our objective consider that some electric system variables are not deterministic, i e there is imprecision or variations, for example, on the loads. In this study, imprecise variables are represented as fuzzy numbers (the bell shape) and is presented a methodology for analysis of electrical networks of distribution through a specialist three-phase load flow that incorporates fuzzy sets and mathematical operations based on fuzzy logic. The results confirm the good performance of this new method.

  17. Glomerular filtration rate and segmental tubular function in the early phase after transplantation/uninephrectomy in recipients and their living-related kidney donors

    DEFF Research Database (Denmark)

    Kamper, A L; Holstein-Rathlou, N H; Strandgaard, S

    1994-01-01

    1. Glomerular filtration rate and sequential tubular function were investigated in 18 adult renal transplant recipients and in their matched, adult living-related kidney donors before and 5 days after transplantation/uninephrectomy. At day 54, 13 donors and 11 recipients were re-investigated. Six......1. Glomerular filtration rate and sequential tubular function were investigated in 18 adult renal transplant recipients and in their matched, adult living-related kidney donors before and 5 days after transplantation/uninephrectomy. At day 54, 13 donors and 11 recipients were re...

  18. Phase transitions

    CERN Document Server

    Sole, Ricard V; Solé, Ricard V; Solé, Ricard V; Sol, Ricard V; Solé, Ricard V

    2011-01-01

    Phase transitions--changes between different states of organization in a complex system--have long helped to explain physics concepts, such as why water freezes into a solid or boils to become a gas. How might phase transitions shed light on important problems in biological and ecological complex systems? Exploring the origins and implications of sudden changes in nature and society, Phase Transitions examines different dynamical behaviors in a broad range of complex systems. Using a compelling set of examples, from gene networks and ant colonies to human language and the degradation of diverse ecosystems, the book illustrates the power of simple models to reveal how phase transitions occur. Introductory chapters provide the critical concepts and the simplest mathematical techniques required to study phase transitions. In a series of example-driven chapters, Ricard Solé shows how such concepts and techniques can be applied to the analysis and prediction of complex system behavior, including the origins of ...

  19. Impact of a stance phase microprocessor-controlled knee prosthesis on level walking in lower functioning individuals with a transfemoral amputation.

    Science.gov (United States)

    Eberly, Valerie J; Mulroy, Sara J; Gronley, JoAnne K; Perry, Jacquelin; Yule, William J; Burnfield, Judith M

    2014-12-01

    For individuals with transfemoral amputation, walking with a prosthesis presents challenges to stability and increases the demand on the hip of the prosthetic limb. Increasing age or comorbidities magnify these challenges. Computerized prosthetic knee joints improve stability and efficiency of gait, but are seldom prescribed for less physically capable walkers who may benefit from them. To compare level walking function while wearing a microprocessor-controlled knee (C-Leg Compact) prosthesis to a traditionally prescribed non-microprocessor-controlled knee prosthesis for Medicare Functional Classification Level K-2 walkers. Crossover. Stride characteristics, kinematics, kinetics, and electromyographic activity were recorded in 10 participants while walking with non-microprocessor-controlled knee and Compact prostheses. Walking with the Compact produced significant increase in velocity, cadence, stride length, single-limb support, and heel-rise timing compared to walking with the non-microprocessor-controlled knee prosthesis. Hip and thigh extension during late stance improved bilaterally. Ankle dorsiflexion, knee extension, and hip flexion moments of the prosthetic limb were significantly improved. Improvements in walking function and stability on the prosthetic limb were demonstrated by the K-2 level walkers when using the C-Leg Compact prosthesis. Understanding the impact of new prosthetic designs on gait mechanics is essential to improve prescription guidelines for deconditioned or older persons with transfemoral amputation. Prosthetic designs that improve stability for safety and walking function have the potential to improve community participation and quality of life. © The International Society for Prosthetics and Orthotics 2013.

  20. Functionalized SBA-15 supported nickel (II)–oxime–imine catalysts for liquid phase oxidation of olefins under solvent-free conditions

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Luna [Department of Chemistry, Jadavpur University, Kolkata 700 032 (India); Banerjee, Biplab [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Bhaumik, Asim, E-mail: msab@iacs.res.in [Department of Materials Science, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Ali, Mahammad, E-mail: m_ali2062@yahoo.com [Department of Chemistry, Jadavpur University, Kolkata 700 032 (India)

    2016-05-15

    A new oxime–imine functionalized highly ordered mesoporous SBA-15 (SBA-15-NH{sub 2}-DAMO) has been synthesized via post-synthesis functionalization of SBA-15 with 3-aminopropyl-triethoxysilane followed by the Schiff base condensation with diacetylmonooxime, which was further reacted with Ni(ClO{sub 4}){sub 2} to yield the functionalized nickel catalyst SBA-15-NH{sub 2}-DAMO-Ni. All the synthesized materials were thoroughly characterized using different characterization techniques. It was found that SBA-15-NH{sub 2}-DAMO-Ni catalyzes the one-pot oxidation of olefins like styrene, cyclohexene, cyclooctene, 1-hexene and 1-octene to the corresponding benzaldehyde, cyclohexene-1-ol and cyclooctene-oxide, respectively under solvent-free conditions by using tert-butylhydroperoxide as oxidant. - Graphical abstract: A new well characterized oxime–imine functionalized highly ordered mesoporous SBA-15-NH{sub 2}-DAMO-Ni complex catalyzes the one-pot oxidation of olefins under solvent free mild conditions.

  1. Deposition of Metal-Organic Frameworks by Liquid-Phase Epitaxy: The Influence of Substrate Functional Group Density on Film Orientation

    Science.gov (United States)

    Liu, Jinxuan; Shekhah, Osama; Stammer, Xia; Arslan, Hasan K.; Liu, Bo; Schüpbach, Björn; Terfort, Andreas; Wöll, Christof

    2012-01-01

    The liquid phase epitaxy (LPE) of the metal-organic framework (MOF) HKUST-1 has been studied for three different COOH-terminated templating organic surfaces prepared by the adsorption of self-assembled monolayers (SAMs) on gold substrates. Three different SAMs were used, mercaptohexadecanoic acid (MHDA), 4’-carboxyterphenyl-4-methanethiol (TPMTA) and 9-carboxy-10-(mercaptomethyl)triptycene (CMMT). The XRD data demonstrate that highly oriented HKUST-1 SURMOFs with an orientation along the (100) direction was obtained on MHDA-SAMs. In the case of the TPMTA-SAM, the quality of the deposited SURMOF films was found to be substantially inferior. Surprisingly, for the CMMT-SAMs, a different growth direction was obtained; XRD data reveal the deposition of highly oriented HKUST-1 SURMOFs grown along the (111) direction.

  2. Deposition of metal-organic frameworks by liquid-phase epitaxy: The influence of substrate functional group density on film orientation

    KAUST Repository

    Liu, J.

    2012-09-05

    The liquid phase epitaxy (LPE) of the metal-organic framework (MOF) HKUST-1 has been studied for three different COOH-terminated templating organic surfaces prepared by the adsorption of self-assembled monolayers (SAMs) on gold substrates. Three different SAMs were used, mercaptohexadecanoic acid (MHDA), 4\\'-carboxyterphenyl-4-methanethiol (TPMTA) and 9-carboxy-10-(mercaptomethyl)triptycene (CMMT). The XRD data demonstrate that highly oriented HKUST-1 SURMOFs with an orientation along the (100) direction was obtained on MHDA-SAMs. In the case of the TPMTA-SAM, the quality of the deposited SURMOF films was found to be substantially inferior. Surprisingly, for the CMMT-SAMs, a different growth direction was obtained; XRD data reveal the deposition of highly oriented HKUST-1 SURMOFs grown along the (111) direction.

  3. Functional Tests of 2S Modules for the CMS Phase-2 Tracker Upgrade with a microTCA-based Readout System

    CERN Document Server

    Preuten, Marius

    2017-01-01

    First full size 2S module prototypes for the CMS Phase-2 Tracker Upgrade have been assembled. With two sensors with realistic geometries and 16 CBC2 readout chips on two front-end hybrids these allow to study the characteristics of these complex objects.A microTCA based readout system was developed to test multiple front-end hybrids simultaneously. Therefore the concurrent information of the full module can be used for differential and common mode noise characterization, as well as for signal tests with radioactive sources or cosmic particles.This talk will discuss the readout system and test results obtained with the first full size 2S module prototypes.

  4. Deposition of Metal-Organic Frameworks by Liquid-Phase Epitaxy: The Influence of Substrate Functional Group Density on Film Orientation

    Directory of Open Access Journals (Sweden)

    Christof Wöll

    2012-09-01

    Full Text Available The liquid phase epitaxy (LPE of the metal-organic framework (MOF HKUST-1 has been studied for three different COOH-terminated templating organic surfaces prepared by the adsorption of self-assembled monolayers (SAMs on gold substrates. Three different SAMs were used, mercaptohexadecanoic acid (MHDA, 4’-carboxyterphenyl-4-methanethiol (TPMTA and 9-carboxy-10-(mercaptomethyltriptycene (CMMT. The XRD data demonstrate that highly oriented HKUST-1 SURMOFs with an orientation along the (100 direction was obtained on MHDA-SAMs. In the case of the TPMTA-SAM, the quality of the deposited SURMOF films was found to be substantially inferior. Surprisingly, for the CMMT-SAMs, a different growth direction was obtained; XRD data reveal the deposition of highly oriented HKUST-1 SURMOFs grown along the (111 direction.

  5. Model of phase distribution of hydrophobic organic chemicals in cyclodextrin-water-air-solid sorbent systems as a function of salinity, temperature, and the presence of multiple CDs

    Science.gov (United States)

    Blanford, W. J.

    2013-12-01

    Environmental and other applications of cyclodextrins (CD) often require usage of high concentra- tion aqueous solutions of derivatized CDs. In an effort to reduce the costs, these studies also typically use technical grades where the purity of the CD solution and the degree of substitution has not been reported. Further, this grade of CD often included high levels of salt and it is commonly applied in high salinity systems. The mathematical models for water and air partitioning coefficients of hydrophobic organic chemicals (HOC) with CDs that have been used in these studies under-estimate the level of HOC within CDs. This is because those models (1) do not take into account that high concentrations of CDs result in significantly lower levels of water in solution and (2) they do not account for the reduction in HOC aqueous solubility due to the presence of salt. Further, because they have poor knowledge of the CD molar concentration in their solu- tions, it is difficult to draw comparisons between studies. Herein is developed a mathematical model where cyclo- dextrin is treated as a separate phase whose relative volume is calculated from its apparent molar volume in solution and the CD concentration of the solution. The model also accounts for the affects of temperature and the presence of salt in solution through inclusion of modified versions of the Van't Hoff and Setschenow equations. With these capabilities, additional equations have been developed for calculating HOC phase distribution in air-water-CD-solid sorbent systems for a single HOC and between water and CD for a system containing multiple HOCs as well as multiple types of cyclodextrin.

  6. Real-time phase-contrast x-ray imaging: a new technique for the study of animal form and function

    Directory of Open Access Journals (Sweden)

    Waters James S

    2007-03-01

    Full Text Available Abstract Background Despite advances in imaging techniques, real-time visualization of the structure and dynamics of tissues and organs inside small living animals has remained elusive. Recently, we have been using synchrotron x-rays to visualize the internal anatomy of millimeter-sized opaque, living animals. This technique takes advantage of partially-coherent x-rays and diffraction to enable clear visualization of internal soft tissue not viewable via conventional absorption radiography. However, because higher quality images require greater x-ray fluxes, there exists an inherent tradeoff between image quality and tissue damage. Results We evaluated the tradeoff between image quality and harm to the animal by determining the impact of targeted synchrotron x-rays on insect physiology, behavior and survival. Using 25 keV x-rays at a flux density of 80 μW/mm-2, high quality video-rate images can be obtained without major detrimental effects on the insects for multiple minutes, a duration sufficient for many physiological studies. At this setting, insects do not heat up. Additionally, we demonstrate the range of uses of synchrotron phase-contrast imaging by showing high-resolution images of internal anatomy and observations of labeled food movement during ingestion and digestion. Conclusion Synchrotron x-ray phase contrast imaging has the potential to revolutionize the study of physiology and internal biomechanics in small animals. This is the only generally applicable technique that has the necessary spatial and temporal resolutions, penetrating power, and sensitivity to soft tissue that is required to visualize the internal physiology of living animals on the scale from millimeters to microns.

  7. Structure, morphology and cell affinity of poly(L-lactide) films surface-functionalized with chitosan nanofibers via a solid-liquid phase separation technique.

    Science.gov (United States)

    Zhao, Jianhao; Han, Wanqing; Tang, Minjian; Tu, Mei; Zeng, Rong; Liang, Zhihong; Zhou, Changren

    2013-04-01

    Poly(L-lactide) films with a nano-structured surface by immobilizing chitosan nanofibers (CSNFs) for improving the cell affinity were fabricated via a solid-liquid phase separation technique. The successful grafting of CSNFs on the surface of poly(L-lactide) films was confirmed by the binding energy of N1s at 398.0 eV in the X-ray photoelectron spectroscopy and the amide I and II bands of chitosan at 1650 and 1568 cm(-1) in the Fourier transform infrared spectroscopy. Compared with the poly(L-lactide) film, the hydrophilicity was improved with a lower water contact angle of 83.3±1.9° and 75.3±2.5° for the CSNFs-grafted and CSNFs-grafted/anchored poly(L-lactide) films respectively. The scanning electron microscopy and atomic force microscopy analyses showed that the grafted CSNFs with 50-500 nm in diameter were randomly arranged on the film surface and entangled with the anchored CSNFs on the outermost layer. The 3T3 fibroblasts culture indicated cells tended to attach and stretch along the CSNFs on the film surface. The cell viability measurement revealed that among all the samples, the film with both grafted and anchored CSNFs exhibited the highest cell proliferation rate that was twice as much of the poly(L-lactide) film at 7 d. Herein, engineering a nano-structured surface by solid-liquid phase separation will be a promising tool for surface modification of biomaterials. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Crystal lattice and phase transitions in Na4TiP2O9 (NTP) and Na4.5FeP2O8(O,F) (NFP) superionic conductors as a function of high pressures and temperatures.

    Science.gov (United States)

    Maximov; Sirota; Werner; Schulz

    1999-06-01

    The lattice dynamics of Na(4)TiP(2)O(9) (tetrasodium titanium diphosphorus nonaoxide, NTP) and Na(4.5)FeP(2)O(8)(O,F) (nonasodium diiron tetraphosphorus difluoride octadecaoxide, NFP) crystals, which are superionic conductors with Na(+)-ion conductivity, were studied under high pressures. Lattice constants as a function of hydrostatic pressure were measured on a four-circle diffractometer using a high-pressure cell with diamond anvils. At 1.78 +/- 0.15 GPa NTP undergoes a reversible phase transition from the modulated monoclinic (pseudo-orthorhombic) modification which is stable under atmospheric conditions. A similar phase transition in NTP is observed at 523 K. For NFP, it may be assumed that at least three phase transitions occur when the pressure increases from atmospheric to 12 GPa, at 1.39 +/- 0.08, 4.52 +/- 0.32, and 6.02 +/- 0.02 GPa, as concluded from the change in the unit-cell parameters and in the color of the crystals: the color changes from ginger (dark orange) to pink at ~1.5-2.0 GPa pressure and to violet at ~6.0 GPa.

  9. Glomerular filtration rate and segmental tubular function in the early phase after transplantation/uninephrectomy in recipients and their living-related kidney donors

    DEFF Research Database (Denmark)

    Kamper, A L; Holstein-Rathlou, N H; Strandgaard, S

    1994-01-01

    1. Glomerular filtration rate and sequential tubular function were investigated in 18 adult renal transplant recipients and in their matched, adult living-related kidney donors before and 5 days after transplantation/uninephrectomy. At day 54, 13 donors and 11 recipients were re-investigated. Six......1. Glomerular filtration rate and sequential tubular function were investigated in 18 adult renal transplant recipients and in their matched, adult living-related kidney donors before and 5 days after transplantation/uninephrectomy. At day 54, 13 donors and 11 recipients were re......-investigated. Sixteen of these constituted eight matched pairs. This reduction in the study population was caused by the application of two withdrawal criteria. 2. In the recipients glomerular filtration rate was unchanged at day 5 and had increased to 61 ml/min at day 54 (P glomerular filtration....../min to 2.10 ml/min at day 54 (P glomerular filtration rate, lithium clearance, absolute and fractional proximal...

  10. Self-assembled thiol monolayers with carboxylic acid functionality: Measuring pH-dependent phase transitions with the quartz crystal microbalance

    International Nuclear Information System (INIS)

    Wang, J.; Frostman, L.M.; Ward, M.D.

    1992-01-01

    The resonant frequency of the quartz crystal microbalance (QCM) coated with self-assembled thiol monolayers with carboxylic acid functionality is measured while the pH of the aqueous solvent is changed in this paper. Increased tensile stress with increasing pH activity partially contributed to the QCM response, but the major contribution was due to changes in the viscoelastic properties of the hydrodynamic layer in contact with the QCM. 28 refs., 3 figs

  11. Phase III multi-center clinical study on sup 99m Tc-GSA, a new agent for functional imaging of the liver

    Energy Technology Data Exchange (ETDEWEB)

    Torizuka, Kanji (Fukui Medical School, Matsuoka (Japan)); Ha-Kawa, Sang Kil; Kudo, Masatoshi (and others)

    1992-02-01

    A multi-center clinical study was performed in patinets with hepatic disorders to evaluate the clinical usefulness of {sup 99m}Tc-DTPA-galactosyl serum albumin ({sup 99m}Tc-GSA), a new radiopharmaceutical which binds to asialoglycoprotein receptors on hepatocytes. The blood clearance and hepatic accumulation were evaluated on the basis of the dynamic data and serial hepatic images obtained for 20 min after {sup 99m}Tc-GSA injection. The blood clearance and hepatic accumulation indices of {sup 99m}Tc-GSA demonstrated the followings. In acute liver diseases, these indices reflected the clinical features of the disease and correlated with the laboratory test indices for the blood coagulation system. In chronic liver diseases, these indices changed in direct proportion to the progression of the hepatic disorder and correlated well with the conventional laboratory test results. In obstructive jaundice, these indices aided evaluation of the liver function despite the high serum bilirubin level. The indices reflected the change in the number of hepatocytes before and after hepatectomy. The scintigraphic findings with {sup 99m}Tc-GSA permitted both functional and morphological evaluations of the liver and provide additional information compared with conventional liver scintigraphy. These results suggest that {sup 99m}Tc-GSA scintigraphy may be useful for evaluating both the functional and morphology of the liver from a new viewpoint of receptor-mediated accumulation. (author).

  12. Smooth Phase Interpolated Keying

    Science.gov (United States)

    Borah, Deva K.

    2007-01-01

    Smooth phase interpolated keying (SPIK) is an improved method of computing smooth phase-modulation waveforms for radio communication systems that convey digital information. SPIK is applicable to a variety of phase-shift-keying (PSK) modulation schemes, including quaternary PSK (QPSK), octonary PSK (8PSK), and 16PSK. In comparison with a related prior method, SPIK offers advantages of better performance and less complexity of implementation. In a PSK scheme, the underlying information waveform that one seeks to convey consists of discrete rectangular steps, but the spectral width of such a waveform is excessive for practical radio communication. Therefore, the problem is to smooth the step phase waveform in such a manner as to maintain power and bandwidth efficiency without incurring an unacceptably large error rate and without introducing undesired variations in the amplitude of the affected radio signal. Although the ideal constellation of PSK phasor points does not cause amplitude variations, filtering of the modulation waveform (in which, typically, a rectangular pulse is converted to a square-root raised cosine pulse) causes amplitude fluctuations. If a power-efficient nonlinear amplifier is used in the radio communication system, the fluctuating-amplitude signal can undergo significant spectral regrowth, thus compromising the bandwidth efficiency of the system. In the related prior method, one seeks to solve the problem in a procedure that comprises two major steps: phase-value generation and phase interpolation. SPIK follows the two-step approach of the related prior method, but the details of the steps are different. In the phase-value-generation step, the phase values of symbols in the PSK constellation are determined by a phase function that is said to be maximally smooth and that is chosen to minimize the spectral spread of the modulated signal. In this step, the constellation is divided into two groups by assigning, to information symbols, phase values

  13. Efficacy of idebenone on respiratory function in patients with Duchenne muscular dystrophy not using glucocorticoids (DELOS): a double-blind randomised placebo-controlled phase 3 trial.

    Science.gov (United States)

    Buyse, Gunnar M; Voit, Thomas; Schara, Ulrike; Straathof, Chiara S M; D'Angelo, M Grazia; Bernert, Günther; Cuisset, Jean-Marie; Finkel, Richard S; Goemans, Nathalie; McDonald, Craig M; Rummey, Christian; Meier, Thomas

    2015-05-02

    Cardiorespiratory failure is the leading cause of death in Duchenne muscular dystrophy. Based on preclinical and phase 2 evidence, we assessed the efficacy and safety of idebenone in young patients with Duchenne muscular dystrophy who were not taking concomitant glucocorticoids. In a multicentre phase 3 trial in Belgium, Germany, the Netherlands, Switzerland, France, Sweden, Austria, Italy, Spain, and the USA, patients (age 10-18 years old) with Duchenne muscular dystrophy were randomly assigned in a one-to-one ratio with a central interactive web response system with a permuted block design with four patients per block to receive idebenone (300 mg three times a day) or matching placebo orally for 52 weeks. Study personnel and patients were masked to treatment assignment. The primary endpoint was change in peak expiratory flow (PEF) as percentage predicted (PEF%p) from baseline to week 52, measured with spirometry. Analysis was by intention to treat (ITT) and a modified ITT (mITT), which was prospectively defined to exclude patients with at least 20% difference in the yearly change in PEF%p, measured with hospital-based and weekly home-based spirometry. This study is registered with ClinicalTrials.gov, number NCT01027884. 31 patients in the idebenone group and 33 in the placebo group comprised the ITT population, and 30 and 27 comprised the mITT population. Idebenone significantly attenuated the fall in PEF%p from baseline to week 52 in the mITT (-3·05%p [95% CI -7·08 to 0·97], p=0·134, vs placebo -9·01%p [-13·18 to -4·84], p=0·0001; difference 5·96%p [0·16 to 11·76], p=0·044) and ITT populations (-2·57%p [-6·68 to 1·54], p=0·215, vs -8·84%p [-12·73 to -4·95], pDuchenne muscular dystrophy. Santhera Pharmaceuticals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Quantum mechanics in phase space

    DEFF Research Database (Denmark)

    Hansen, Frank

    1984-01-01

    A reformulation of quantum mechanics for a finite system is given using twisted multiplication of functions on phase space and Tomita's theory of generalized Hilbert algebras. Quantization of a classical observable h is achieved when the twisted exponential Exp0(-h) is defined as a tempered....... Generalized Weyl-Wigner maps related to the notion of Hamiltonian weight are studied and used in the formulation of a twisted spectral theory for functions on phase space. Some inequalities for Wigner functions on phase space are proven. A brief discussion of the classical limit obtained through dilations...

  15. Applying functional metagenomics to search for novel lignocellulosic enzymes in a microbial consortium derived from a thermophilic composting phase of sugarcane bagasse and cow manure.

    Science.gov (United States)

    Colombo, Lívia Tavares; de Oliveira, Marcelo Nagem Valério; Carneiro, Deisy Guimarães; de Souza, Robson Assis; Alvim, Mariana Caroline Tocantins; Dos Santos, Josenilda Carlos; da Silva, Cynthia Canêdo; Vidigal, Pedro Marcus Pereira; da Silveira, Wendel Batista; Passos, Flávia Maria Lopes

    2016-09-01

    Environments where lignocellulosic biomass is naturally decomposed are sources for discovery of new hydrolytic enzymes that can reduce the high cost of enzymatic cocktails for second-generation ethanol production. Metagenomic analysis was applied to discover genes coding carbohydrate-depleting enzymes from a microbial laboratory subculture using a mix of sugarcane bagasse and cow manure in the thermophilic composting phase. From a fosmid library, 182 clones had the ability to hydrolyse carbohydrate. Sequencing of 30 fosmids resulted in 12 contigs encoding 34 putative carbohydrate-active enzymes belonging to 17 glycosyl hydrolase (GH) families. One third of the putative proteins belong to the GH3 family, which includes β-glucosidase enzymes known to be important in the cellulose-deconstruction process but present with low activity in commercial enzyme preparations. Phylogenetic analysis of the amino acid sequences of seven selected proteins, including three β-glucosidases, showed low relatedness with protein sequences deposited in databases. These findings highlight microbial consortia obtained from a mixture of decomposing biomass residues, such as sugar cane bagasse and cow manure, as a rich resource of novel enzymes potentially useful in biotechnology for saccharification of lignocellulosic substrate.

  16. Salicylic acid functionalized silica-coated magnetite nanoparticles for solid phase extraction and preconcentration of some heavy metal ions from various real samples

    Directory of Open Access Journals (Sweden)

    Afkhami Abbas

    2011-07-01

    Full Text Available Abstract A method for the preconcentration of trace heavy metal ions in environmental samples has been reported. The presented method is based on the sorption of Cu(II, Cd(II, Ni(II and Cr(III ions with salicylic acid as respective chelate on silica-coated magnetite nanoparticles. Prepared adsorbent was characterized by XRD, SEM, BET and FT-IR measurements. The metals content of the sorbed complexes are eluted using 4.0 mL of 1.0 mol L-1 nitric acid. The influences of the analytical parameters including pH, amount of solid phase and condition of eluting solution, the effects of matrix ions on the retention of the analytes were examined. The accuracy and precision of suggested method were tested by analyzing of certified reference materials. The detection limits (3Sb/m, N = 8 for Cu(II, Cd(II, Ni(II and Cr(III ions are 0.22, 0.11, 0.27 and 0.15 μg L-1, respectively, and the maximum preconcentration factor is 200. The method was successfully applied to the evaluation of these trace and toxic metals in various waters, foods and other samples.

  17. Phase IV prospective clinical study to evaluate the effect of taurine on liver function in postsurgical adult patients requiring parenteral nutrition.

    Science.gov (United States)

    Arrieta, Francisco; Balsa, José Antonio; de la Puerta, Cristina; Botella, José Ignacio; Zamarrón, Isabel; Elías, Elena; Del Río, José Ignacio Pérez; Alonso, Paloma; Candela, Angel; Blanco-Colio, Luis Miguel; Egido, Jesús; Navarro, Pilar; Vázquez, Clotilde

    2014-10-01

    Taurine's role in bile acid metabolism and anti-inflammatory activity could exert a protective effect on hepatobiliary complications associated with parenteral nutrition (PN). In this study, the effects of 2 amino acid solutions, with and without taurine, on liver function administered to nonacutely ill postsurgical patients as part of a short-term PN regimen were prospectively compared. Adult patients randomly received (double-blind) Tauramin 10% or a standard PN solution without taurine as the control (1.5 g amino acid/kg body weight [bw]/d; infusion rate of ≤4 mg glucose/kg bw/d) for a period of 5-30 days. γ-Glutamyl transpeptidase (GGT) and other indicators of liver function, glucose metabolism, lipid profile, inflammation markers, and treatment safety data were collected. Thirty-five patients receiving taurine PN and 39 receiving control PN were enrolled (intention-to-treat [ITT] population). Most patients (n = 62) discontinued after day 7 of follow-up (per-protocol [PP] population: n = 24 and n = 27, respectively). ITT patients with high GGT values after 5 days of PN comprised 68.6% and 64.1%, respectively. The mean change in GGT values with respect to the baseline values was 167 ± 192 and 157 ± 185 IU/L, respectively. Low-density lipoprotein (LDL) cholesterol levels after 7 days of PN were significantly decreased in the taurine PN group of PP patients (-2.83 ± 30.9 vs 23.9 ± 27.0 mg/dL for control PN; P taurine PN: n = 6; control PN: n = 7) were treatment related. PN solutions with and without taurine had similar effects on liver function parameters, except for an LDL reduction in PN with taurine, when administered to nonacutely ill postsurgical patients in the short term (5-7 days). © 2014 American Society for Parenteral and Enteral Nutrition.

  18. Novel Palm Fatty Acid Functionalized Magnetite Nanoparticles for Magnetic Solid-Phase Extraction of Trace Polycyclic Aromatic Hydrocarbons from Environmental Samples.

    Science.gov (United States)

    Rozi, Siti Khalijah Mahmad; Nodeh, Hamid Rashidi; Kamboh, Muhammad Afzal; Manan, Ninie Suhana Abdul; Mohamad, Sharifah

    2017-07-01

    A novel adsorbent, palm fatty acid coated magnetic Fe 3 O 4 nanoparticles (MNP-FA) was successfully synthesized with immobilization of the palm fatty acid onto the surface of MNPs. The successful synthesis of MNP-FA was further confirmed by X-Ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and Energy dispersive X-Ray spectroscopy (EDX) analyses and water contact angle (WCA) measurement. This newly synthesized MNP-FA was applied as magnetic solid phase extraction (MSPE) adsorbent for the enrichment of polycyclic aromatic hydrocarbons (PAHs), namely fluoranthene (FLT), pyrene (Pyr), chrysene (Cry) and benzo(a)pyrene (BaP) from environmental samples prior to High Performance Liquid Chromatography- Diode Array Detector (HPLC-DAD) analysis. The MSPE method was optimized by several parameters such as amount of sorbent, desorption solvent, volume of desorption solvent, extraction time, desorption time, pH and sample volume. Under the optimized conditions, MSPE method provided a low detection limit (LOD) for FLT, Pyr, Cry and BaP in the range of 0.01-0.05 ng mL -1 . The PAHs recoveries of the spiked leachate samples ranged from 98.5% to 113.8% with the RSDs (n = 5) ranging from 3.5% to 12.2%, while for the spiked sludge samples, the recoveries ranged from 81.1% to 119.3% with the RSDs (n = 5) ranging from 3.1% to 13.6%. The recyclability study revealed that MNP-FA has excellent reusability up to five times. Chromatrographic analysis demonstrated the suitability of MNP-FA as MSPE adsorbent for the efficient extraction of PAHs from environmental samples.

  19. The prodromal phase of obesity-related chronic kidney disease: early alterations in cardiovascular and renal function in obese children and adolescents.

    Science.gov (United States)

    Doyon, Anke; Schaefer, Franz

    2013-11-01

    Childhood overweight and obesity is a relevant health condition with multi-organ involvement. Obesity shows significant tracking into adult life and is associated with an increased risk of serious adverse health outcomes both during childhood and later adulthood. The classical sequelae of obesity such as hypertension, metabolic syndrome and inflammation do develop at a paediatric age. Cardiovascular consequences, such as increased carotid intima-media thickness, and left ventricular hypertrophy, as well as functional alterations of the heart and arteries, are commonly traceable at an early age. Renal involvement can occur at a young age and is associated with a high probability of progressive chronic kidney disease. There is solid evidence suggesting that consequent treatment including both lifestyle changes and pharmacological therapy can reduce cardiovascular, metabolic and renal risks in obese children and adolescents.

  20. Validity of the four-parameter empirical formula in approximating the response functions for gamma-ray, neutron, and secondary gamma-ray skyshine analyses

    CERN Document Server

    Harima, Y; Sakamoto, Y

    2003-01-01

    A four-parameter approximating formula, R=A e sup a x sup b f(x), accurately represents the skyshine line beam response function (LBRF) as a function of the distance (x) of the source-to-detector separation. Here, A is a constant for a given source energy and f(x)=e sup c sup x x sup d sup x is a damping factor. The four parameters are obtained as follows. (1) The value of parameter a corresponds to that of the LBRF at x=1 meter, which is the result of integrating the basic dose spectrum due to a single scattering particle from an emitted beam for a specified angle and a specified source energy. (2) The value of parameter b corresponds to the slope of a straight line of the response function, log R vs. log x, in the range of small distance from a source, where a single scattering particle dominates. (3) The damping factor (f(x)) represents the attenuation trend of the LBRF at distances far from the source; the values of parameters c and d control the quantity of attenuation. The necessary reference LBRF data ...

  1. Phase 1 Trial of Bevacizumab With Concurrent Chemoradiation Therapy for Squamous Cell Carcinoma of the Head and Neck With Exploratory Functional Imaging of Tumor Hypoxia, Proliferation, and Perfusion

    Energy Technology Data Exchange (ETDEWEB)

    Nyflot, Matthew J., E-mail: nyflot@uw.edu [Department of Radiation Oncology, University of Washington, Seattle, Washington (United States); Kruser, Tim J. [Department of Radiation Oncology, Cadence Cancer Center at Delnor Hospital, Geneva, Illinois (United States); Traynor, Anne M. [Department of Medicine, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Khuntia, Deepak [Varian Medical Systems, Palo Alto, California (United States); Yang, David T. [Departments of Pathology and Laboratory Medicine, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Hartig, Gregory K.; McCulloch, Timothy M. [Department of Surgery-Otolaryngology, H& N Surgery Division, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Wiederholt, Peggy A. [Department of Human Oncology, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Gentry, Lindell R. [Department of Radiology, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Hoang, Tien [Department of Medicine, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Jeraj, Robert [Department of Human Oncology, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Department of Radiology, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); Department of Medical Physics, University of Wisconsin Carbone Cancer Center and School of Medicine and Public Health, Madison, Wisconsin (United States); and others

    2015-04-01

    Purpose: A phase 1 trial was completed to examine the safety and feasibility of combining bevacizumab with radiation and cisplatin in patients with locoregionally advanced squamous cell carcinoma of the head and neck (HNSCC) treated with curative intent. Additionally, we assessed the capacity of bevacizumab to induce an early tumor response as measured by a series of biological imaging studies. Methods and Materials: All patients received a single induction dose of bevacizumab (15 mg/kg) delivered 3 weeks (±3 days) before the initiation of chemoradiation therapy. After the initial dose of bevacizumab, comprehensive head and neck chemoradiation therapy was delivered with curative intent to 70 Gy in 33 fractions with concurrent weekly cisplatin at 30 mg/m{sup 2} and bevacizumab every 3 weeks (weeks 1, 4, 7) with dose escalation from 5 to 10 to 15 mg/kg. All patients underwent experimental imaging with [{sup 18}F]fluorothymidine positron emission tomography (FLT-PET) (proliferation), [{sup 61}Cu]Cu-diacetyl-bis(N4-methylthiosemicarbazone) PET (Cu-ATSM-PET) (hypoxia), and dynamic contrast-enhanced computed tomography (DCE-CT) (perfusion) at 3 time points: before bevacizumab monotherapy, after bevacizumab monotherapy, and during the combined therapy course. Results: Ten patients were enrolled. All had stage IV HNSCC, all achieved a complete response to treatment, and 9 of 10 remain alive, with a mean survival time of 61.3 months. All patients experienced grade 3 toxicity, but no dose-limiting toxicities or significant bleeding episodes were observed. Significant reductions were noted in tumor proliferation (FLT-PET), tumor hypoxia (Cu-ATSM-PET), and DCE-CT contrast enhancement after bevacizumab monotherapy, with further decreases in FLT-PET and Cu-ATSM-PET during the combined therapy course. Conclusions: The incorporation of bevacizumab into comprehensive chemoradiation therapy regimens for patients with HNSCC appears safe and feasible. Experimental imaging

  2. Functional imaging and circulating biomarkers of response to regorafenib in treatment-refractory metastatic colorectal cancer patients in a prospective phase II study.

    Science.gov (United States)

    Khan, Khurum; Rata, Mihaela; Cunningham, David; Koh, Dow-Mu; Tunariu, Nina; Hahne, Jens C; Vlachogiannis, George; Hedayat, Somaieh; Marchetti, Silvia; Lampis, Andrea; Damavandi, Mahnaz Darvish; Lote, Hazel; Rana, Isma; Williams, Anja; Eccles, Suzanne A; Fontana, Elisa; Collins, David; Eltahir, Zakaria; Rao, Sheela; Watkins, David; Starling, Naureen; Thomas, Jan; Kalaitzaki, Eleftheria; Fotiadis, Nicos; Begum, Ruwaida; Bali, Maria; Rugge, Massimo; Temple, Eleanor; Fassan, Matteo; Chau, Ian; Braconi, Chiara; Valeri, Nicola

    2017-08-08

    Regorafenib demonstrated efficacy in patients with metastatic colorectal cancer (mCRC). Lack of predictive biomarkers, potential toxicities and cost-effectiveness concerns highlight the unmet need for better patient selection. Patients with RAS mutant mCRC with biopsiable metastases were enrolled in this phase II trial. Dynamic contrast-enhanced (DCE) MRI was acquired pretreatment and at day 15 post-treatment. Median values of volume transfer constant (K trans ), enhancing fraction (EF) and their product KEF (summarised median values of K trans × EF) were generated. Circulating tumour (ct) DNA was collected monthly until progressive disease and tested for clonal RAS mutations by digital-droplet PCR. Tumour vasculature (CD-31) was scored by immunohistochemistry on 70 sequential tissue biopsies. Twenty-seven patients with paired DCE-MRI scans were analysed. Median KEF decrease was 58.2%. Of the 23 patients with outcome data, >70% drop in KEF (6/23) was associated with higher disease control rate (p=0.048) measured by RECIST V. 1.1 at 2 months, improved progression-free survival (PFS) (HR 0.16 (95% CI 0.04 to 0.72), p=0.02), 4-month PFS (66.7% vs 23.5%) and overall survival (OS) (HR 0.08 (95% CI 0.01 to 0.63), p=0.02). KEF drop correlated with CD-31 reduction in sequential tissue biopsies (p=0.04). RAS mutant clones decay in ctDNA after 8 weeks of treatment was associated with better PFS (HR 0.21 (95% CI 0.06 to 0.71), p=0.01) and OS (HR 0.28 (95% CI 0.07-1.04), p=0.06). Combining DCE-MRI and ctDNA predicts duration of anti-angiogenic response to regorafenib and may improve patient management with potential health/economic implications. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  3. The eigenvalue problem in phase space.

    Science.gov (United States)

    Cohen, Leon

    2017-07-27

    We formulate the standard quantum mechanical eigenvalue problem in quantum phase space. The equation obtained involves the c-function that corresponds to the quantum operator. We use the Wigner distribution for the phase space function. We argue that the phase space eigenvalue equation obtained has, in addition to the proper solutions, improper solutions. That is, solutions for which no wave function exists which could generate the distribution. We discuss the conditions for ascertaining whether a position momentum function is a proper phase space distribution. We call these conditions psi-representability conditions, and show that if these conditions are imposed, one extracts the correct phase space eigenfunctions. We also derive the phase space eigenvalue equation for arbitrary phase space distributions functions. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  4. Use of plant stanol ester margarine among persons with and without cardiovascular disease: Early phases of the adoption of a functional food in Finland

    Directory of Open Access Journals (Sweden)

    Boice John D

    2005-06-01

    Full Text Available Abstract Background The plant stanol ester margarine Benecol® is a functional food that has been shown to lower effectively serum total and LDL-cholesterol. The purpose of this post-marketing study is to characterize users of plant stanol ester margarine with and without cardiovascular disease. Methods A cohort of plant stanol ester margarine users was established based on a compilation of 15 surveys conducted by the National Public Health Institute in Finland between 1996–2000. There were 29 772 subjects aged 35–84 years in the cohort. The users of plant stanol ester margarine were identified by the type of bread spread used. Results The plant stanol ester margarine was used as bread spread by 1332 (4.5% subjects. Almost half (46% of the users reported a history of cardiovascular disease. Persons with cardiovascular disease were more likely to use plant stanol ester margarine (8% than persons without cardiovascular disease (3%. Users with and without cardiovascular disease seemed to share similar characteristics. In particular, they were elderly people with otherwise healthy life-styles and diet. They were less likely smokers, more likely physically active and less likely obese than nonusers. The users reported being in good or average health in general and having used cholesterol-lowering drugs. Conclusion Plant stanol ester margarine seems to be used by persons for whom it was designed and in a way it was meant: as part of efforts for cardiovascular disease risk reduction.

  5. Rmi1 functions in S phase-mediated cohesion establishment via a pathway involving the Ctf18-RFC complex and Mrc1.

    Science.gov (United States)

    Lai, Mong Sing; Seki, Masayuki; Tada, Shusuke; Enomoto, Takemi

    2012-10-26

    Saccharomyces cerevisiae RecQ helicase (Sgs1) combines with DNA topoisomerase III (Top3) and RecQ-mediated genome instability 1 (Rmi1) to form an evolutionarily conserved complex that is required for processing homologous recombination intermediates and restarting collapsed replication forks. It was previously reported that Rmi1 contributes to sister chromatid cohesion; however, the underlying molecular mechanism has been unclear. In the present study, Rmi1 was found to be enriched at the region close to an early-firing replication origin when replication forks were arrested near their origins in the presence of hydroxyurea. Genetic analyses revealed that Rmi1 promoted sister chromatid cohesion in a process that was distinct from both the cohesion establishment pathway involving Ctf4, Csm3, and Chl1 and the pathway involving the acetylation of Smc3. On the other hand, Rmi1 seemed to function in a pathway involving the Ctf18-RFC complex and Mrc1, which were previously predicted to regulate leading-strand DNA replication. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Solid phase extraction of heavy metal ions based on a novel functionalized magnetic multi-walled carbon nanotube composite with the aid of experimental design methodology

    International Nuclear Information System (INIS)

    Taghizadeh, Mohsen; Asgharinezhad, Ali Akbar; Samkhaniany, Noorallah; Tadjarodi, Azadeh; Abbaszadeh, Abolfazl; Pooladi, Mohsen

    2014-01-01

    We report that magnetic multiwalled carbon nanotubes functionalized with 8-aminoquinoline can be applied to the preconcentration of Cd(II), Pb(II) and Ni(II) ions. The parameters affecting preconcentration were optimized by a Box-Behnken design through response surface methodology. Three variables (extraction time, magnetic sorbent amount, and pH value) were selected as the main factors affecting sorption, and four variables (type, volume and concentration of the eluent; elution time) were selected for optimizing elution. Following sorption and elution, the ions were quantified by FAAS. The LODs are 0.09, 0.72, and 1.0 ng mL −1 for Cd(II), Ni(II), and Pb(II) ions, respectively. The relative standard deviations are <5.1 % for five separate batch determinations at 30 ng mL −1 level of Cd(II), Ni(II), and Pb(II) ions. The sorption capacities (in mg g −1 ) of this new sorbent are 201 for Cd(II), 150 for Pb(II), and 172 Ni(II). The composite was successfully applied to the rapid extraction of trace quantities of heavy metal ions in fish, sediment, soil, and water samples. (author)

  7. (Nbx, Zr1-x)4AlC3 MAX Phase Solid Solutions: Processing, Mechanical Properties, and Density Functional Theory Calculations.

    Science.gov (United States)

    Lapauw, Thomas; Tytko, Darius; Vanmeensel, Kim; Huang, Shuigen; Choi, Pyuck-Pa; Raabe, Dierk; Caspi, El'ad N; Ozeri, Offir; To Baben, Moritz; Schneider, Jochen M; Lambrinou, Konstantina; Vleugels, Jozef

    2016-06-06

    The solubility of zirconium (Zr) in the Nb4AlC3 host lattice was investigated by combining the experimental synthesis of (Nbx, Zr1-x)4AlC3 solid solutions with density functional theory calculations. High-purity solid solutions were prepared by reactive hot pressing of NbH0.89, ZrH2, Al, and C starting powder mixtures. The crystal structure of the produced solid solutions was determined using X-ray and neutron diffraction. The limited Zr solubility (maximum of 18.5% of the Nb content in the host lattice) in Nb4AlC3 observed experimentally is consistent with the calculated minimum in the energy of mixing. The lattice parameters and microstructure were evaluated over the entire solubility range, while the chemical composition of (Nb0.85, Zr0.15)4AlC3 was mapped using atom probe tomography. The hardness, Young's modulus, and fracture toughness at room temperature as well as the high-temperature flexural strength and E-modulus of (Nb0.85, Zr0.15)4AlC3 were investigated and compared to those of pure Nb4AlC3. Quite remarkably, an appreciable increase in fracture toughness was observed from 6.6 ± 0.1 MPa/m(1/2) for pure Nb4AlC3 to 10.1 ± 0.3 MPa/m(1/2) for the (Nb0.85, Zr0.15)4AlC3 solid solution.

  8. Ponderomotive phase plate for transmission electron microscopes

    Science.gov (United States)

    Reed, Bryan W [Livermore, CA

    2012-07-10

    A ponderomotive phase plate system and method for controllably producing highly tunable phase contrast transfer functions in a transmission electron microscope (TEM) for high resolution and biological phase contrast imaging. The system and method includes a laser source and a beam transport system to produce a focused laser crossover as a phase plate, so that a ponderomotive potential of the focused laser crossover produces a scattering-angle-dependent phase shift in the electrons of the post-sample electron beam corresponding to a desired phase contrast transfer function.

  9. Functionalized synchrotron in-line phase-contrast computed tomography: a novel approach for simultaneous quantification of structural alterations and localization of barium-labelled alveolar macrophages within mouse lung samples.

    Science.gov (United States)

    Dullin, Christian; dal Monego, Simeone; Larsson, Emanuel; Mohammadi, Sara; Krenkel, Martin; Garrovo, Chiara; Biffi, Stefania; Lorenzon, Andrea; Markus, Andrea; Napp, Joanna; Salditt, Tim; Accardo, Agostino; Alves, Frauke; Tromba, Giuliana

    2015-01-01

    Functionalized computed tomography (CT) in combination with labelled cells is virtually non-existent due to the limited sensitivity of X-ray-absorption-based imaging, but would be highly desirable to realise cell tracking studies in entire organisms. In this study we applied in-line free propagation X-ray phase-contrast CT (XPCT) in an allergic asthma mouse model to assess structural changes as well as the biodistribution of barium-labelled macrophages in lung tissue. Alveolar macrophages that were barium-sulfate-loaded and fluorescent-labelled were instilled intratracheally into asthmatic and control mice. Mice were sacrificed after 24 h, lungs were kept in situ, inflated with air and scanned utilizing XPCT at the SYRMEP beamline (Elettra Synchrotron Light Source, Italy). Single-distance phase retrieval was used to generate data sets with ten times greater contrast-to-noise ratio than absorption-based CT (in our setup), thus allowing to depict and quantify structural hallmarks of asthmatic lungs such as reduced air volume, obstruction of airways and increased soft-tissue content. Furthermore, we found a higher concentration as well as a specific accumulation of the barium-labelled macrophages in asthmatic lung tissue. It is believe that XPCT will be beneficial in preclinical asthma research for both the assessment of therapeutic response as well as the analysis of the role of the recruitment of macrophages to inflammatory sites.

  10. Coincidence: Fortran code for calculation of (e, e'x) differential cross-sections, nuclear structure functions and polarization asymmetry in self-consistent random phase approximation with Skyrme interaction

    Energy Technology Data Exchange (ETDEWEB)

    Cavinato, M.; Marangoni, M.; Saruis, A.M.

    1990-10-01

    This report describes the COINCIDENCE code written for the IBM 3090/300E computer in Fortran 77 language. The output data of this code are the (e, e'x) threefold differential cross-sections, the nuclear structure functions, the polarization asymmetry and the angular correlation coefficients. In the real photon limit, the output data are the angular distributions for plane polarized incident photons. The code reads from tape the transition matrix elements previously calculated, by in continuum self-consistent RPA (random phase approximation) theory with Skyrme interactions. This code has been used to perform a numerical analysis of coincidence (e, e'x) reactions with polarized electrons on the /sup 16/O nucleous.

  11. Comparison between two-phase and one-phase SLIPI for instantaneous imaging of transient sprays

    Science.gov (United States)

    Mishra, Yogeshwar Nath; Kristensson, Elias; Koegl, Matthias; Jönsson, Joakim; Zigan, Lars; Berrocal, Edouard

    2017-09-01

    Imaging through optically dense sprays is challenging due to the detection of multiple light scattering, which blurs the recorded images and limits visibility. Structured laser illumination planar imaging (SLIPI) is a technique that is capable of reducing the intensity contribution that stems from multiple scattering in a light sheet imaging configuration. The conventional SLIPI approach is based on recording three modulated sub-images successively, each having a different spatial phase, and has, therefore, been mostly used for temporally averaged imaging. To circumvent this limitation and image spray dynamics, `instantaneous' two-phase (2p) and single-phase (1p) SLIPI approaches have recently been developed. The purpose of the work presented here is to compare these two approaches in terms of optical design, image post-processing routines, multiple scattering suppression ability, and spatial resolution. The two approaches are used to image a transient direct-injection spark-ignition ethanol spray, for both liquid laser-induced fluorescence and Mie scattering detection. The capabilities of the approaches for multiple scattering suppression and image formation have also been numerically modeled by means of Monte Carlo simulation. This article shows that both approaches efficiently suppress the contribution from multiple light scattering, providing images with an intensity profile close to the corresponding single scattering case. Experimentally, this suppression renders both an improvement in image contrast and the removal of undesired stray light components that could be interpreted as signal. However, while 2p-SLIPI preserves most of the initial spatial resolution, 1p-SLIPI results in a loss of spatial resolution, where high-frequency image information is not visible anymore. Thus, there is a trade-off between preserving the most detailed information of the spray structure—with 2p-SLIPI—and being able to record an SLIPI image from a single modulated image

  12. Phase Vocoder

    Directory of Open Access Journals (Sweden)

    J.L. Flanagan

    2013-08-01

    Full Text Available A vocoder technique is described in which speech signals are represented by their short-time phase and amplitude spectra. A complete transmission system utilizing this approach is simulated on a digital computer. The encoding method leads to an economy in transmission bandwidth and to a means for time compression and expansion of speech signals.

  13. Phase transitions in operational risk.

    Science.gov (United States)

    Anand, Kartik; Kühn, Reimer

    2007-01-01

    In this paper we explore the functional correlation approach to operational risk. We consider networks with heterogeneous a priori conditional and unconditional failure probability. In the limit of sparse connectivity, self-consistent expressions for the dynamical evolution of order parameters are obtained. Under equilibrium conditions, expressions for the stationary states are also obtained. Consequences of the analytical theory developed are analyzed using phase diagrams. We find coexistence of operational and nonoperational phases, much as in liquid-gas systems. Such systems are susceptible to discontinuous phase transitions from the operational to nonoperational phase via catastrophic breakdown. We find this feature to be robust against variation of the microscopic modeling assumptions.

  14. Measurement by phase severance

    International Nuclear Information System (INIS)

    Noyes, H.P.

    1987-03-01

    It is claimed that the measurement process is more accurately described by ''quasi-local phase severance'' than by ''wave function collapse''. The approach starts from the observation that the usual route to quantum mechanics starting from the Hamilton-Jacobi equations throws away half the degrees of freedom, namely, the classical initial state parameters. To overcome this difficulty, the full set of Hamilton-Jacobi equations is interpreted as operator equations acting on a state vector. The measurement theory presented is based on the conventional S-matrix boundary condition of N/sub A/ free particles in the distant past and N/sub B/ free particles in the distant future and taking the usual free particle wave functions, multiplied by phase factors

  15. Preparation of magnetic graphene/mesoporous silica composites with phenyl-functionalized pore-walls as the restricted access matrix solid phase extraction adsorbent for the rapid extract