Measurements of the volume scattering function in a coastal environment
Berthon, Jean-François; Lee, Michael; Shybanov, Eugeny; Zibordi, Giuseppe
2007-04-01
The Volume Scattering Function (VSF) is an essential variable in the context of marine radiative transfer modeling and of the inversion of ocean colour remote sensing data. However, an important lack of knowledge on the VSF natural variability affects the present models, in particular for the coastal environment. Measurements of the Volume Scattering Function between 0.6° and 177.3° with an angular resolution of 0.3° were performed in the northern coastal Adriatic Sea onboard an oceanographic platform in October 2004 using a prototype instrument. Observed differences with the commonly used Petzold's functions are significant, in particular for the "open ocean" and "coastal" types in the backward directions. The use of an empirical relationship for the derivation of b b(λ) from a unique measurement of β(ψ,λ) at ψ=140 for the Hydroscat-6 was validated for this coastal site at that season. Finally, the use of the Kopelevich VSF model together with a measurement of b p(λ) at λ=555 nm allowed the reconstruction of the VSF to within about 35%.
DEFF Research Database (Denmark)
Cannavacciuolo, L.; Sommer, C.; Pedersen, J.S.;
2000-01-01
We present a systematic Monte Carlo study of the scattering function S(q) of semiflexible polyelectrolytes at infinite dilution, in solutions with different concentrations of added salt. In the spirit of a theoretical description of polyelectrolytes in terms of the equivalent parameters, namely...... outlined in the Odijk-Skolnick-Fixman theory, in which the behavior of charged polymers is described only in terms of increasing local rigidity and excluded volume effects. Moreover, the Monte Carlo data are found to be in very good agreement with experimental scattering measurements with equilibrium...
Soltanmoradi, Elmira; Shokri, Babak
2017-05-01
In this article, the electromagnetic wave scattering from plasma columns with inhomogeneous electron density distribution is studied by the Green's function volume integral equation method. Due to the ready production of such plasmas in the laboratories and their practical application in various technological fields, this study tries to find the effects of plasma parameters such as the electron density, radius, and pressure on the scattering cross-section of a plasma column. Moreover, the incident wave frequency influence of the scattering pattern is demonstrated. Furthermore, the scattering cross-section of a plasma column with an inhomogeneous collision frequency profile is calculated and the effect of this inhomogeneity is discussed first in this article. These results are especially used to determine the appropriate conditions for radar cross-section reduction purposes. It is shown that the radar cross-section of a plasma column reduces more for a larger collision frequency, for a relatively lower plasma frequency, and also for a smaller radius. Furthermore, it is found that the effect of the electron density on the scattering cross-section is more obvious in comparison with the effect of other plasma parameters. Also, the plasma column with homogenous collision frequency can be used as a better shielding in contrast to its inhomogeneous counterpart.
Measurements and modeling of the volume scattering function in the coastal northern Adriatic Sea
Berthon, Jean-François; Shybanov, Eugeny; Lee, Michael E.-G.; Zibordi, Giuseppe
2007-08-01
We performed measurements of the volume scattering function (VSF) between 0.5° and 179° with an angular resolution of 0.3° in the northern Adriatic Sea onboard an oceanographic platform during three different seasons, using the multispectral volume scattering meter (MVSM) instrument. We observed important differences with respect to Petzold's commonly used functions, whereas the Fournier-Forand's analytical formulation provided a rather good description of the measured VSF. The comparison of the derived scattering, bp(λ) and backscattering, bbp(λ) coefficients for particles with the measurements performed with the classical AC-9 and Hydroscat-6 showed agreement to within 20%. The use of an empirical relationship for the derivation of bb(λ) from β(ψ,λ) at ψ=140° was validated for this coastal site although ψ=118° was confirmed to be the most appropriate angle. The low value of the factor used to convert β(ψ,λ) into bb(λ) within the Hydroscat-6 processing partially contributed to the underestimation of bb(λ) with respect to the MVSM. Finally, use of the Kopelevich model together with a measurement of bp(λ) at λ=555 nm allowed us to reconstruct the VSF with average rms percent differences between 8 and 15%.
Composed Scattering Model for Direct Volume Rendering
Institute of Scientific and Technical Information of China (English)
蔡文立; 石教英
1996-01-01
Based on the equation of transfer in transport theory of optical physics,a new volume rendering model,called composed scattering model(CSM),is presented.In calculating the scattering term of the equation,it is decomposed into volume scattering intensity and surface scattering intensity,and they are composed with the boundary detection operator as the weight function.This proposed model differs from the most current volume rendering models in the aspect that in CSM segmentation and illumination intensity calculation are taken as two coherent parts while in existing models they are regarded as two separate ones.This model has been applied to the direct volume rendering of 3D data sets obtained by CT and MRI.The resultant images show not only rich details but also clear boundary surfaces.CSM is demonstrated to be an accurate volume rendering model suitable for CT and MRI data sets.
SCATTERING FUNCTION OF POLYMER BLENDS
Institute of Scientific and Technical Information of China (English)
Lin-ping Ke; Mei-li Guo; De-lu Zhao
2004-01-01
For a system of flexible polymer molecules, the concepts of two concentrations, namely the segmental and the molecular concentrations, have been proposed in this paper. The former is equivalent to the volume fraction. The latter can be defined as the number of the gravity centers of macromolecules in a unit volume. The two concentrations should be correlated with each other by the conformational function of the polymer chain and should be discussed in different thermodynamic equations. On the basis of these concepts it has been proved that the Flory-Huggins entropy of mixing should be the result of the mixing "ideal gases of the gravity centers of macromolecules". The general correlation between the free energy of mixing and the scattering function (structural factor) of polymer blends has been studied based on the general fluctuation theory. When the Flory-Huggins free energy of mixing is adopted, the de Gennes scattering function of a polymer blend can be derived.
Account of Nuclear Scattering at Volume Reflection
Bondarenco, M V
2011-01-01
For a particle traversing a bent crystal in the regime of volume reflection we evaluate the probability of interaction with atomic nuclei. Regardless of the continuous potential shape, this probability is found to differ from the corresponding value in an amorphous target by an amount proportional to the crystal bending radius, and the particle deflection angle. Based on this result, we evaluate the rate of inelastic nuclear interactions, and the final beam angular dispersion due to multiple Coulomb scattering. The theoretical predictions are compared with the experiments. The impact of multiple Coulomb scattering on the mean volume reflection angle is also discussed.
Scattering from Star Polymers including Excluded Volume Effects
Li, Xin; Liu, Yun; Sánchez-Diáz, Luis E; Hong, Kunlun; Smith, Gregory S; Chen, Wei-Ren
2014-01-01
In this work we present a new model for the form factor of a star polymer consisting of self-avoiding branches. This new model incorporates excluded volume effects and is derived from the two point correlation function for a star polymer.. We compare this model to small angle neutron scattering (SANS) measurements from polystyrene (PS) stars immersed in a good solvent, tetrahydrofuran (THF). It is shown that this model provides a good description of the scattering signature originating from the excluded volume effect and it explicitly elucidates the connection between the global conformation of a star polymer and the local stiffness of its constituent branch.
Finite volume corrections to pi pi scattering
Energy Technology Data Exchange (ETDEWEB)
Sato, Ikuro; Bedaque, Paulo F.; Walker-Loud, Andre
2006-01-13
Lattice QCD studies of hadron-hadron interactions are performed by computing the energy levels of the system in a finite box. The shifts in energy levels proportional to inverse powers of the volume are related to scattering parameters in a model independent way. In addition, there are non-universal exponentially suppressed corrections that distort this relation. These terms are proportional to e-m{sub pi} L and become relevant as the chiral limit is approached. In this paper we report on a one-loop chiral perturbation theory calculation of the leading exponential corrections in the case of I=2 pi pi scattering near threshold.
Electromagnetic scattering by spheroidal volumes of discrete random medium
Mishchenko, Michael I.; Dlugach, Janna M.
2017-10-01
We use the superposition T-matrix method to compare the far-field scattering matrices generated by spheroidal and spherical volumes of discrete random medium having the same volume and populated by identical spherical particles. Our results fully confirm the robustness of the previously identified coherent and diffuse scattering regimes and associated optical phenomena exhibited by spherical particulate volumes and support their explanation in terms of the interference phenomenon coupled with the order-of-scattering expansion of the far-field Foldy equations. We also show that increasing nonsphericity of particulate volumes causes discernible (albeit less pronounced) optical effects in forward and backscattering directions and explain them in terms of the same interference/multiple-scattering phenomenon.
Measurements of Scattering Function of sea water in Southern Baltic
Freda, W.; Król1, T.; Martynov, O. V.; Shybanov, E. B.; Hapter, R.
2007-05-01
The Volume Scattering Functions (VSF) were measured in Southern Baltic area. The instrument used to this aim allow to measure in full range of angles and for four wavelengths. Obtained characteristics create the set of data which is need to solve the radiative transfer equation. Measured functions were compared with Petzold Average-Particle Phase Function. Spectral variations of measured scattering coefficients and backscattering coefficients are presented. Furthermore the instability of measured scattering ratios is discussed in this paper. Such instability have not been mentioned in the literature before.
Large volume high-pressure cell for inelastic neutron scattering
Energy Technology Data Exchange (ETDEWEB)
Wang, W.; Kamenev, K. V. [Centre for Science at Extreme Conditions and School of Engineering, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Sokolov, D. A.; Huxley, A. D. [SUPA, Centre for Science at Extreme Conditions and School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom)
2011-07-15
Inelastic neutron scattering measurements typically require two orders of magnitude longer data collection times and larger sample sizes than neutron diffraction studies. Inelastic neutron scattering measurements on pressurised samples are particularly challenging since standard high-pressure apparatus restricts sample volume, attenuates the incident and scattered beams, and contributes background scattering. Here, we present the design of a large volume two-layered piston-cylinder pressure cell with optimised transmission for inelastic neutron scattering experiments. The design and the materials selected for the construction of the cell enable its safe use to a pressure of 1.8 GPa with a sample volume in excess of 400 mm{sup 3}. The design of the piston seal eliminates the need for a sample container, thus providing a larger sample volume and reduced absorption. The integrated electrical plug with a manganin pressure gauge offers an accurate measurement of pressure over the whole range of operational temperatures. The performance of the cell is demonstrated by an inelastic neutron scattering study of UGe{sub 2}.
Large volume high-pressure cell for inelastic neutron scattering
Wang, W.; Sokolov, D. A.; Huxley, A. D.; Kamenev, K. V.
2011-07-01
Inelastic neutron scattering measurements typically require two orders of magnitude longer data collection times and larger sample sizes than neutron diffraction studies. Inelastic neutron scattering measurements on pressurised samples are particularly challenging since standard high-pressure apparatus restricts sample volume, attenuates the incident and scattered beams, and contributes background scattering. Here, we present the design of a large volume two-layered piston-cylinder pressure cell with optimised transmission for inelastic neutron scattering experiments. The design and the materials selected for the construction of the cell enable its safe use to a pressure of 1.8 GPa with a sample volume in excess of 400 mm3. The design of the piston seal eliminates the need for a sample container, thus providing a larger sample volume and reduced absorption. The integrated electrical plug with a manganin pressure gauge offers an accurate measurement of pressure over the whole range of operational temperatures. The performance of the cell is demonstrated by an inelastic neutron scattering study of UGe2.
Efficient light propagation for multiple anisotropic volume scattering
Energy Technology Data Exchange (ETDEWEB)
Max, N. [Lawrence Livermore National Lab., CA (United States)]|[California Univ., Davis, CA (United States)
1993-12-01
Realistic rendering of participating media like clouds requires multiple anisotropic light scattering. This paper presents a propagation approximation for light scattered into M direction bins, which reduces the ``ray effect`` problem in the traditional ``discrete ordinates`` method. For a volume of n{sup 3} elements, it takes O(M n{sup 3} log n + M{sup 2} n{sup 3}) time and O(M n{sup 3}) space.
Finding related functional neuroimaging volumes
DEFF Research Database (Denmark)
Nielsen, Finn Årup; Hansen, Lars Kai
2004-01-01
We describe a content-based image retrieval technique for finding related functional neuroimaging experiments by voxelization of sets of stereotactic coordinates in Talairach space, comparing the volumes and reporting related volumes in a sorted list. Voxelization is accomplished by convolving each...
Three-particle scattering amplitudes from a finite volume formalism
Briceno, Raul A
2012-01-01
We present a quantization condition for the spectrum of a system composed of three identical bosons in a finite volume with periodic boundary conditions. This condition gives a relation between the finite volume spectrum and infinite volume scattering amplitudes. The quantization condition presented is an integral equation that in general must be solved numerically. However, for systems with an attractive two-body force that supports a two-body bound-state, a diboson, and for energies below the diboson breakup, the quantization condition reduces to the well-known Luscher formula with exponential corrections in volume that scale with the diboson binding momentum. To accurately determine infinite volume phase shifts, it is necessary to extrapolate the phase shifts obtained from the Luscher formula for the boson-diboson system to the infinite volume limit. For energies above the breakup threshold, or for systems with no two-body bound-state (with only scattering states and resonances) the Luscher formula gets po...
Radiative properties of materials with surface scattering or volume scattering: A review
Institute of Scientific and Technical Information of China (English)
Qunzhi ZHU; Hyunjin LEE; Zhuomin M. ZHANG
2009-01-01
Radiative properties of rough surfaces, parti-culate media and porous materials are important in thermal engineering and many other applications. These properties are often needed for calculating heat transfer between surfaces and volume elements in participating media, as well as for accurate radiometric temperature measure-ments. In this paper, recent research on scattering of thermal radiation by rough surfaces, fibrous insulation, soot, aerogel, biological materials, and polytetrafluor-oethylene (PTFE) is reviewed. Both theoretical modeling and experimental investigation are discussed. Rigorous solutions and approximation methods for surface scattering and volume scattering are described. The approach of using measured surface roughness statistics in Monte Carlo simulations to predict radiative properties of rough surfaces is emphasized. The effects of various parameters on the radiative properties of particulate media and porous materials are summarized.
Rogers, Jeremy D.
2016-03-01
Numerous methods have been developed to quantify the light scattering properties of tissue. These properties are of interest in diagnostic and screening applications due to sensitivity to changes in tissue ultrastructure and changes associated with disease such as cancer. Tissue is considered a weak scatterer because that the mean free path is much larger than the correlation length. When this is the case, all scattering properties can be calculated from the refractive index correlation function Bn(r). Direct measurement of Bn(r) is challenging because it requires refractive index measurement at high resolution over a large tissue volume. Instead, a model is usually assumed. One particularly useful model, the Whittle-Matern function includes several realistic function types such as mass fractal and exponential. Optical scattering properties for weakly scattering media can be determined analytically from Bn(r) by applying the Rayleigh-Gans-Debye (RGD) or Born Approximation, and so measured scattering properties are used to fit parameters of the model function. Direct measurement of Bn(r) would provide confirmation that the function is a good representation of tissue or help in identifying the length scale at which changes occur. The RGD approximation relates the scattering phase function to the refractive index correlation function through a Fourier transform. This can be inverted without approximation, so goniometric measurement of the scattering can be converted to Bn(r). However, geometric constraints of the measurement of the phase function, angular resolution, and wavelength result in a band limited measurement of Bn(r). These limits are discussed and example measurements are described.
Sayed, Sadeed Bin
2016-11-02
An explicit marching on-in-time scheme for analyzing transient electromagnetic wave interactions on ferromagnetic scatterers is described. The proposed method solves a coupled system of time domain magnetic field volume integral and Landau-Lifshitz-Gilbert (LLG) equations. The unknown fluxes and fields are discretized using full and half Schaubert-Wilton-Glisson functions in space and bandlimited temporal interpolation functions in time. The coupled system is cast in the form of an ordinary differential equation and integrated in time using a PE(CE)m type linear multistep method to obtain the unknown expansion coefficients. Numerical results demonstrating the stability and accuracy of the proposed scheme are presented.
Scattering Function for Branched Wormlike Chains.
Vogtt, Karsten; Beaucage, Gregory; Weaver, Michael; Jiang, Hanqiu
2015-08-04
Wormlike or threadlike structures with local cylindrical geometry are abundantly found in nature and technical products. A thorough structural characterization in the bulk for a whole ensemble, however, is difficult. The inherent semiordered nature of the tortuous large-scale structure and especially the quantification of branching renders an assessment difficult. In the present work we introduce a hybrid function expressing the scattering intensities for X-rays, neutrons, or light in the small-angle regime for this system. The function is termed "hybrid" because it employs terms from different approaches. The large-scale structure is described via a Guinier term as well as a concomitant power-law expression in momentum transfer q taken from the so-called unified function. The local cylindrical shape, however, is taken into account through a form factor for cylinders from rigid-body modeling. In principle, the latter form factor can be replaced by an expression for any other regular body so that the new hybrid function is a versatile tool for studying hierarchical structures assembled from uniform subunits. The appropriateness and capability of the new function for cylindrical structures is exemplified using the example of a wormlike micellar system.
Monte Carlo solution of the volume-integral equation of electromagnetic scattering
Peltoniemi, J.; Muinonen, K.
2014-07-01
Electromagnetic scattering is often the main physical process to be understood when interpreting the observations of asteroids, comets, and meteors. Modeling the scattering faces still many problems, and one needs to assess several different cases: multiple scattering and shadowing by the rough surface, multiple scattering inside a surface element, and single scattering by a small object. Our specific goal is to extend the electromagnetic techniques to larger and more complicated objects, and derive approximations taking into account the most important effects of waves. Here we experiment with Monte Carlo techniques: can they provide something new to solving the scattering problems? The electromagnetic wave equation in the presence of a scatterer of volume V and refractive index m, with an incident wave EE_0, including boundary conditions and the scattering condition at infinity, can be presented in the form of an integral equation EE(rr)(1+suski(rr) Q(ρ))-int_{V-V_ρ}ddrr' GG(rr-rr')suski(rr')EE(rr') =EE_0, where suski(rr)=m(rr)^2-1, Q(ρ)=-1/3+{cal O}(ρ^2)+{O'}(m^2ρ^2), {O}, and {O'} are some second- and higher-order corrections for the finite-size volume V_ρ of radius ρ around the singularity and GG is the dyadic Green's function of the form GG(RR)={exp(im kR)}/{4π R}[unittensor(1+{im}/{R}-{1}/{R^2})-RRRR(1+{3im}/{R}-{3}/{R^2})]. In general, this is solved by extending the internal field in terms of some simple basis functions, e.g., plane or spherical waves or a cubic grid, approximating the integrals in a clever way, and determining the goodness of the solution somehow, e.g., moments or least square. Whatever the choice, the solution usually converges nicely towards a correct enough solution when the scatterer is small and simple, and diverges when the scatterer becomes too complicated. With certain methods, one can reach larger scatterers faster, but the memory and CPU needs can be huge. Until today, all successful solutions are based on more or less
Deorientation of PolSAR coherency matrix for volume scattering retrieval
Kumar, Shashi; Garg, R. D.; Kushwaha, S. P. S.
2016-05-01
Polarimetric SAR data has proven its potential to extract scattering information for different features appearing in single resolution cell. Several decomposition modelling approaches have been developed to retrieve scattering information from PolSAR data. During scattering power decomposition based on physical scattering models it becomes very difficult to distinguish volume scattering as a result from randomly oriented vegetation from scattering nature of oblique structures which are responsible for double-bounce and volume scattering , because both are decomposed in same scattering mechanism. The polarization orientation angle (POA) of an electromagnetic wave is one of the most important character which gets changed due to scattering from geometrical structure of topographic slopes, oriented urban area and randomly oriented features like vegetation cover. The shift in POA affects the polarimetric radar signatures. So, for accurate estimation of scattering nature of feature compensation in polarization orientation shift becomes an essential procedure. The prime objective of this work was to investigate the effect of shift in POA in scattering information retrieval and to explore the effect of deorientation on regression between field-estimated aboveground biomass (AGB) and volume scattering. For this study Dudhwa National Park, U.P., India was selected as study area and fully polarimetric ALOS PALSAR data was used to retrieve scattering information from the forest area of Dudhwa National Park. Field data for DBH and tree height was collect for AGB estimation using stratified random sampling. AGB was estimated for 170 plots for different locations of the forest area. Yamaguchi four component decomposition modelling approach was utilized to retrieve surface, double-bounce, helix and volume scattering information. Shift in polarization orientation angle was estimated and deorientation of coherency matrix for compensation of POA shift was performed. Effect of
Tissue scattering parameter estimation through scattering phase function measurements by goniometer
Institute of Scientific and Technical Information of China (English)
Ying Zhu; Zhihua Ding; Martial Geiser
2007-01-01
@@ An automated optical system is built up to perform goniometric measurement of scattering phase function.Measurements of typical samples including monodisperse polystyrene micro-spheres solution, and mutlidisperse polystyrene micro-spheres solution are carried out in a dark room. The possibility of estimating the average particle size of phantom through analyzing its scattering phase function is demonstrated.
A test of cirrus ice crystal scattering phase functions
Field, P. R.; Baran, A. J.; Kaye, P. H.; Hirst, E.; Greenaway, R.
2003-07-01
In-situ ice crystal scattering has been measured in cirrus cloud with the Small Ice Detector laser scattering probe. Using light scattered from single particles (maximum dimension ~<100 μm) at 4-10° and 20-40° we have tested ice crystal scattering phase functions for spheres, hexagonal columns, hexagonal plates, polycrystals an aggregate of columns and an analytic function. We find that phase functions that lack a pronounced 22° halo are the best representatives for the example data presented here. Spherical ice particle phase functions do not satisfy the measurements.
Probability density functions of instantaneous Stokes parameters on weak scattering
Chen, Xi; Korotkova, Olga
2017-10-01
The single-point probability density functions (PDF) of the instantaneous Stokes parameters of a polarized plane-wave light field scattered from a three-dimensional, statistically stationary, weak medium with Gaussian statistics and Gaussian correlation function have been studied for the first time. Apart from the scattering geometry the PDF distributions of the scattered light have been related to the illumination's polarization state and the correlation properties of the medium.
A Time Marching Scheme for Solving Volume Integral Equations on Nonlinear Scatterers
Bagci, Hakan
2015-01-07
Transient electromagnetic field interactions on inhomogeneous penetrable scatterers can be analyzed by solving time domain volume integral equations (TDVIEs). TDVIEs are oftentimes solved using marchingon-in-time (MOT) schemes. Unlike finite difference and finite element schemes, MOT-TDVIE solvers require discretization of only the scatterers, do not call for artificial absorbing boundary conditions, and are more robust to numerical phase dispersion. On the other hand, their computational cost is high, they suffer from late-time instabilities, and their implicit nature makes incorporation of nonlinear constitutive relations more difficult. Development of plane-wave time-domain (PWTD) and FFT-based schemes has significantly reduced the computational cost of the MOT-TDVIE solvers. Additionally, latetime instability problem has been alleviated for all practical purposes with the development of accurate integration schemes and specially designed temporal basis functions. Addressing the third challenge is the topic of this presentation. I will talk about an explicit MOT scheme developed for solving the TDVIE on scatterers with nonlinear material properties. The proposed scheme separately discretizes the TDVIE and the nonlinear constitutive relation between electric field intensity and flux density. The unknown field intensity and flux density are expanded using half and full Schaubert-Wilton-Glisson (SWG) basis functions in space and polynomial temporal interpolators in time. The resulting coupled system of the discretized TDVIE and constitutive relation is integrated in time using an explicit P E(CE) m scheme to yield the unknown expansion coefficients. Explicitness of time marching allows for straightforward incorporation of the nonlinearity as a function evaluation on the right hand side of the coupled system of equations. Consequently, the resulting MOT scheme does not call for a Newton-like nonlinear solver. Numerical examples, which demonstrate the applicability
Directory of Open Access Journals (Sweden)
Sang-Eun Park
2012-05-01
Full Text Available In this paper, the three-component power decomposition for polarimetric SAR (PolSAR data with an adaptive volume scattering model is proposed. The volume scattering model is assumed to be reflection-symmetric but parameterized. For each image pixel, the decomposition first starts with determining the adaptive parameter based on matrix similarity metric. Then, a respective scattering power component is retrieved with the established procedure. It has been shown that the proposed method leads to complete elimination of negative powers as the result of the adaptive volume scattering model. Experiments with the PolSAR data from both the NASA/JPL (National Aeronautics and Space Administration/Jet Propulsion Laboratory Airborne SAR (AIRSAR and the JAXA (Japan Aerospace Exploration Agency ALOS-PALSAR also demonstrate that the proposed method not only obtains similar/better results in vegetated areas as compared to the existing Freeman-Durden decomposition but helps to improve discrimination of the urban regions.
TIME-DOMAIN VOLUME INTEGRAL EQUATION FOR TRANSIENT SCATTERING FROM INHOMOGENEOUS OBJECTS-2D TM CASE
Institute of Scientific and Technical Information of China (English)
Wang Jianguo; Fan Ruyu
2001-01-01
This letter proposes a time-domain volume integral equation based method for analyzing the transient scattering from a 2D inhomogeneous cylinder by involking the volume equivalence principle for the transverse magnetic case. This integral equation is solved by using an MOT scheme. Numerical results obtained using this method agree very well with those obtained using the FDTD method.
TIME-DOMAIN VOLUME INTEGRAL EQUATION FOR TRANSIENT SCATTERING FROM INHOMOGENEOUS OBJECTS-2D TE CASE
Institute of Scientific and Technical Information of China (English)
Wang Jianguo; Fan Ruyu
2001-01-01
This letter proposes a time-domain volume integral equation based method for analyzing the transient scattering from a 2D inhomogeneous cylinder by involking the volume equivalence principle for the transverse electric case. This integral equation is solved by using an MOT scheme. Numerical results obtained using this method agree very well with those obtained using the FDTD method.
H-function for three-term scattering indicatrix
Karanjai, S.; Karanjai, M.
1985-07-01
In solving the equation of transfer for a semiinfinite, plane-parallel atmosphere, the emergent intensity is largely obtained in terms of Chandrasekhar's H-function; in cases where the H-function is within an integral sign, a good approximate form is needed to minimize computational effort. The Karanjai and Sen (1971) H-function approximation for isotropic scattering is presently extended to the case of the three-term scattering indicatrix.
Anisotropy function for pion-proton elastic scattering
Energy Technology Data Exchange (ETDEWEB)
Saleem, Mohammad; Fazal-e-Aleem; Rashid, Haris
1988-09-01
By using the generalised Chou-Yang model and the experimental data on ..pi../sup -/p elastic scattering at 200 GeV/c, the anisotropy function which reflects the non-isotropic nature of elastic scattering is computed for the reaction ..pi../sup -/p -> ..pi../sup -/p.
Anisotropy function for proton-proton elastic scattering
Energy Technology Data Exchange (ETDEWEB)
Saleem, Mohammad; Fazal-e-Aleem; Azhar, I.A. (Punjab Univ., Lahore (Pakistan). Centre for High Energy Physics)
1990-07-01
By using the generalized Chou-Yang model and the experimental data on pp elastic scattering at 53 GeV, the anisotropy function which reflects the non-isotropic nature of elastic scattering is computed for the reaction pp{yields}pp. (author).
Directory of Open Access Journals (Sweden)
Jungki Lee
2015-01-01
Full Text Available The parallel volume integral equation method (PVIEM is applied for the analysis of elastic wave scattering problems in an unbounded isotropic solid containing multiple multilayered anisotropic elliptical inclusions. This recently developed numerical method does not require the use of Green’s function for the multilayered anisotropic inclusions; only Green’s function for the unbounded isotropic matrix is needed. This method can also be applied to solve general two- and three-dimensional elastodynamic problems involving inhomogeneous and/or multilayered anisotropic inclusions whose shape and number are arbitrary. A detailed analysis of the SH wave scattering is presented for multiple triple-layered orthotropic elliptical inclusions. Numerical results are presented for the displacement fields at the interfaces for square and hexagonal packing arrays of triple-layered elliptical inclusions in a broad frequency range of practical interest. It is necessary to use standard parallel programming, such as MPI (message passing interface, to speed up computation in the volume integral equation method (VIEM. Parallel volume integral equation method as a pioneer of numerical analysis enables us to investigate the effects of single/multiple scattering, fiber packing type, fiber volume fraction, single/multiple layer(s, multilayer’s shape and geometry, isotropy/anisotropy, and softness/hardness of the multiple multilayered anisotropic elliptical inclusions on displacements at the interfaces of the inclusions.
Generalized functions, volume 1 properties and operations
Gel′fand, I M
2016-01-01
The first systematic theory of generalized functions (also known as distributions) was created in the early 1950s, although some aspects were developed much earlier, most notably in the definition of the Green's function in mathematics and in the work of Paul Dirac on quantum electrodynamics in physics. The six-volume collection, Generalized Functions, written by I. M. Gel′fand and co-authors and published in Russian between 1958 and 1966, gives an introduction to generalized functions and presents various applications to analysis, PDE, stochastic processes, and representation theory. Volume 1
Structure functions in electron-nucleon deep inelastic scattering
Energy Technology Data Exchange (ETDEWEB)
Saleem, M.; Fazal-E-Aleem (University of the Punjab, Lahore (Pakistan). Dept. of Physics)
1982-06-26
The phenomenological expressions for the structure functions in electron-nucleon deep inelastic scattering are proposed and are shown to satisfy the experimental data as well as a number of sum rules.
Sayed, Sadeed Bin
2014-07-01
A marching on-in-time (MOT)-based time domain volume electric field integral equation (TD-VEFIE) solver is proposed for accurate and stable analysis of electromagnetic wave interactions on high-contrast scatterers. The stability is achieved using band-limited but two-sided (non-causal) temporal interpolation functions and an extrapolation scheme to cast the time marching into a causal form. The extrapolation scheme is designed to be highly accurate for oscillating and exponentially decaying fields, hence it accurately captures the physical behavior of the resonant modes that are excited inside the dielectric scatterer. Numerical results demonstrate that the resulting MOT scheme maintains its stability as the number of resonant modes increases with the contrast of the scatterer.
Finite volume effects in low-energy neutron-deuteron scattering
Rokash, Alexander; Krebs, Hermann; Lee, Dean; Meißner, Ulf-G
2013-01-01
We present a lattice calculation of neutron-deuteron scattering at very low energies and investigate in detail the impact of the topological finite-volume corrections. Our calculations are carried out in the framework of pionless effective field theory at leading order in the low-energy expansion. Using lattice sizes and a lattice spacing comparable to those employed in nuclear lattice simulations, we find that the topological volume corrections must be taken into account in order to obtain correct results for the neutron-proton S-wave scattering lengths.
Reactive Scattering Wave Functions by Linear Combination of Arrangement Channels
Institute of Scientific and Technical Information of China (English)
邓从豪; 冯大诚; 蔡政亭
1994-01-01
The similarity and dissimilarity of reactive scattering wave functions and molecular orbitalby linear combination of atomic orbitals(LCAOMO)are examined.Based on the similarity a method is pro-posed to construct the reactive scattering wave functions by linear combination of arrangement channel wavefunctions(LCACSW).Based on the dissimilarity,it is shown that the combination coefficients can be deter-mined by solving s set of simultaneous algebraic equations.The elements of the reactive scattering matrix areshown to be related to the combination coefficients of open arrangement channels.The differential and totalreactive scattering cross-section derived by this method agrees completely with that derived by other meth-ods.
The spectral shift function for planar obstacle scattering at low energy
McGillivray, I E
2011-01-01
Let $H$ signify the free non-negative Laplacian on $\\mathbb{R}^2$ and $H_Y$ the non-negative Dirichlet Laplacian on the complement $Y$ of a nonpolar compact subset $K$ in the plane. We derive the low-energy expansion for the Krein spectral shift function (scattering phase) for the obstacle scattering system $\\{\\,H_Y,\\,H\\,\\}$ including detailed expressions for the first three coefficients. We use this to investigate the large time behaviour of the expected volume of the pinned Wiener sausage associated to $K$.
Roca, L
2012-01-01
We present a way to evaluate the scattering of unstable particles quantized in a finite volume with the aim of extracting physical observables for infinite volume from lattice data. We illustrate the method with the $\\pi\\rho$ scattering which generates dynamically the axial-vector $a_1(1260)$ resonance. Energy levels in a finite box are evaluated both considering the $\\rho$ as a stable and unstable resonance and we find significant differences between both cases. We discuss how to solve the problem to get the physical scattering amplitudes in the infinite volume, and hence phase shifts, from possible lattice results on energy levels quantized inside a finite box.
Effects of subsurface volume scattering on the lunar microwave brightness temperature spectrum
Keihm, S. J.
1982-01-01
The effects of volumetric scattering on the lunar microwave brightness temperature are examined for a broad range of feasible lunar rock population distributions. Mie-scattering phase functions and the radiative transfer method are utilized. Surveyor and Apollo data relevant to lunar rock size distributions are discussed, and parameters are chosen for nine scattering models which liberally cover the range of studied rock population distributions. Scattering model brightness temperature predictions are analyzed in terms of the lunar disk center emission averaged over a lunation for wavelengths of 3-30 cm. The effects of scattering on the amplitude of disk center brightness temperature variations and resultant deductions of regolith electrical loss are examined. Constraints on the global scale variability of subsurface scatterers imposed by microwave brightness temperature maps are considered.
DEFF Research Database (Denmark)
Saffman, Mark; Zoletnik, S.; Basse, Nils Plesner
2001-01-01
We describe and demonstrate a two-volume collective scattering system for localized measurements of plasma turbulence. The finite crossfield correlation length of plasma turbulence combined with spatial variations in the magnetic field direction are used to obtain spatially localized turbulence...
The Effects of Sand Sediment Volume Heterogeneities on Sound Propagation and Scattering
2012-09-30
14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18. NUMBER OF PAGES 7 19a. NAME OF RESPONSIBLE...Jones and D. R. Jackson, “Small perturbation method of high-frequency bistatic volume scattering from marine sediments,” Oceanic Engineering, IEEE J. of
Generalized functions, volume 2 spaces of fundamental and generalized functions
Gel′fand, I M
2016-01-01
The first systematic theory of generalized functions (also known as distributions) was created in the early 1950s, although some aspects were developed much earlier, most notably in the definition of the Green's function in mathematics and in the work of Paul Dirac on quantum electrodynamics in physics. The six-volume collection, Generalized Functions, written by I. M. Gel′fand and co-authors and published in Russian between 1958 and 1966, gives an introduction to generalized functions and presents various applications to analysis, PDE, stochastic processes, and representation theory. Volume 2
Functional imaging of small tissue volumes with diffuse optical tomography
Klose, Alexander D.; Hielscher, Andreas H.
2006-03-01
Imaging of dynamic changes in blood parameters, functional brain imaging, and tumor imaging are the most advanced application areas of diffuse optical tomography (DOT). When dealing with the image reconstruction problem one is faced with the fact that near-infrared photons, unlike X-rays, are highly scattered when they traverse biological tissue. Image reconstruction schemes are required that model the light propagation inside biological tissue and predict measurements on the tissue surface. By iteratively changing the tissue-parameters until the predictions agree with the real measurements, a spatial distribution of optical properties inside the tissue is found. The optical properties can be related to the tissue oxygenation, inflammation, or to the fluorophore concentration of a biochemical marker. If the model of light propagation is inaccurate, the reconstruction process will lead to an inaccurate result as well. Here, we focus on difficulties that are encountered when DOT is employed for functional imaging of small tissue volumes, for example, in cancer studies involving small animals, or human finger joints for early diagnosis of rheumatoid arthritis. Most of the currently employed image reconstruction methods rely on the diffusion theory that is an approximation to the equation of radiative transfer. But, in the cases of small tissue volumes and tissues that contain low scattering regions diffusion theory has been shown to be of limited applicability Therefore, we employ a light propagation model that is based on the equation of radiative transfer, which promises to overcome the limitations.
The Lauricella functions and exact string scattering amplitudes
Lai, Sheng-Hong; Lee, Jen-Chi; Yang, Yi
2016-11-01
We discover that the 26 D open bosonic string scattering amplitudes (SSA) of three tachyons and one arbitrary string state can be expressed in terms of the D-type Lauricella functions with associated SL(K+3,C) symmetry. As a result, SSA and symmetries or relations among SSA of different string states at various limits calculated previously can be rederived. These include the linear relations first conjectured by Gross [1-5] and later corrected and proved in [6-12] in the hard scattering limit, the recurrence relations in the Regge scattering limit with associated SL(5,C) symmetry [24-26] and the extended recurrence relations in the nonrelativistic scattering limit with associated SL(4,C) symmetry [29] discovered recently. Finally, as an application, we calculate a new recurrence relation of SSA which is valid for all energies.
The Lauricella Functions and Exact String Scattering Amplitudes
Lai, Sheng-Hong; Yang, Yi
2016-01-01
We discover that the 26D open bosonic string scattering amplitudes (SSA) of three tachyons and one arbitrary string state can be expressed in terms of the D-type Lauricella functions with associated SL(K+3,C) symmetry. As a result, SSA and symmetries or relations among SSA of different string states at various limits calculated previously can be rederived. These include the linear relations first conjectured by Gross [1-3] and later corrected and proved in [4-9] in the hard scattering limit, the recurrence relations in the Regge scattering limit with associated SL(5,C) symmetry [19-21] and the extended recurrence relations in the nonrelativistic scattering limit with associated SL(4,C) symmetry [24] discovered recently. Finally, as an application, we calculate a new recurrence relation of SSA which is valid for all energies.
Structure Function Sum rules for Systems with Large Scattering Lengths
Goldberger, Walter D
2010-01-01
We use a dispersion relation in conjunction with the operator product expansion (OPE) to derive model independent sum rules for the dynamic structure functions of systems with large scattering lengths. We present an explicit sum rule for the structure functions that control the density and spin response of the many-body ground state. Our methods are general, and apply to either fermions or bosons which interact through two-body contact interactions with large scattering lengths. By employing a Borel transform of the OPE, the relevant integrals are weighted towards infrared frequencies, thus allowing for greater overlap low energy data. Similar sum rules can be derived for other response functions. The sum rules can be used to extract the contact parameter introduced by Tan, including universality violating corrections at finite scattering lengths.
Absorption and scattering 2-D volcano images from numerically calculated space-weighting functions
Del Pezzo, Edoardo; Ibañez, Jesus; Prudencio, Janire; Bianco, Francesca; De Siena, Luca
2016-08-01
Short-period small magnitude seismograms mainly comprise scattered waves in the form of coda waves (the tail part of the seismogram, starting after S waves and ending when the noise prevails), spanning more than 70 per cent of the whole seismogram duration. Corresponding coda envelopes provide important information about the earth inhomogeneity, which can be stochastically modeled in terms of distribution of scatterers in a random medium. In suitable experimental conditions (i.e. high earth heterogeneity), either the two parameters describing heterogeneity (scattering coefficient), intrinsic energy dissipation (coefficient of intrinsic attenuation) or a combination of them (extinction length and seismic albedo) can be used to image Earth structures. Once a set of such parameter couples has been measured in a given area and for a number of sources and receivers, imaging their space distribution with standard methods is straightforward. However, as for finite-frequency and full-waveform tomography, the essential problem for a correct imaging is the determination of the weighting function describing the spatial sensitivity of observable data to scattering and absorption anomalies. Due to the nature of coda waves, the measured parameter couple can be seen as a weighted space average of the real parameters characterizing the rock volumes illuminated by the scattered waves. This paper uses the Monte Carlo numerical solution of the Energy Transport Equation to find approximate but realistic 2-D space-weighting functions for coda waves. Separate images for scattering and absorption based on these sensitivity functions are then compared with those obtained with commonly used sensitivity functions in an application to data from an active seismic experiment carried out at Deception Island (Antarctica). Results show that these novel functions are based on a reliable and physically grounded method to image magnitude and shape of scattering and absorption anomalies. Their
Effective Spectral Function for Quasielastic Scattering on Nuclei
Bodek, A; Coopersmith, B
2014-01-01
Spectral functions that are used in neutrino event generators (such as GENIE, NEUT, NUANCE, NUWRO, and GiBUU) to model quasielastic(QE) scattering from nuclear targets include Fermi gas, Local Thomas Fermi gas (LTF), Bodek-Ritche Fermi gas with high momentum tail, and the Benhar Fantoni two dimensional spectral function. We find that the predictions of these spectral functions for the $\\frac{d\\sigma}{d\
Volume Effects in Discrete beta functions
Liu, Yuzhi; Zou, Haiyuan
2011-01-01
We calculate discrete beta functions corresponding to the two-lattice matching for the 2D O(N) models and Dyson's hierarchical model. We describe and explain finite-size effects such as the appearance of a nontrivial infrared fixed point that goes to infinity at infinite volume or the merging of an infrared and an ultraviolet fixed point. We present extensions of the RG flows to the complex coupling plane. We discuss the possibility of constructing a continuous beta function from the discrete one by using functional conjugation methods. We briefly discuss the relevance of these findings for the search of nontrivial fixed points in multiflavor lattice gauge theory models.
Finite-volume Hamiltonian method for $\\pi\\pi$ scattering in lattice QCD
Wu, Jia-Jun; Leinweber, Derek B; Thomas, A W; Young, Ross D
2015-01-01
Within a formulation of $\\pi\\pi$ scattering, we investigate the use of the finite-volume Hamiltonian approach to resolving scattering observables from lattice QCD spectra. We consider spectra in the centre-of-mass and moving frames for both S- and P-wave cases. Furthermore, we investigate the multi-channel case. Here we study the use of the Hamiltonian framework as a parametrization that can be fit directly to lattice spectra. Through this method, the hadron properties, such as mass, width and coupling, can be directly extracted from the lattice spectra.
Angular Dispersion and Deflection Function for Heavy Ion Elastic Scattering
Institute of Scientific and Technical Information of China (English)
BAI Zhen; MAO Rui-Shi; YUAN Xiao-Hua; Xu Zhi-Guo; ZHANG Hong-Bin; XU Hua-Gen; QI Hui-Rong; WANG Yue; JIA Fei; WU Li-Jie; DING Xian-Li; WANG Qi; GAO Qi; GAO Hui; LI Song-Lin; LI Jun-Qing; ZHANG Ya-Peng; XIAO Guo-Qing; JIN Gen-Ming; REN Zhong-Zhou; ZHOU Shan-Gui; XU Wang; HAN Jian-Long; Fan Gong-Tao; ZHANG Shuang-Quan; PANG Dan-Yang; SERGEY Yu-Kun; XIAO Zhi-Gang; XU Hu-Shan; SUN Zhi-Yu; HU Zheng-Guo; ZHANG Xue-Ying; WANG Hong-Wei
2007-01-01
The differential cross sections for elastic scattering products of17 F on 208 Pb have been measured.The angular dispersion plots of In(dσ/dθ)versus θ2 are obtained from the angular distribution of the elastic scattering differential cross sections.Systematical analysis on the angular dispersion for the available experimental data indicates that there is an angular dispersion turning angle at forward angular range within the grazing angle.This turning angle can be clarified as nuclear rainbow in classical deflection function.The exotic behaviour of the nuclear rainbow angle offers a new probe to investigate the halo and skin phenomena.
Cluster functions and scattering amplitudes for six and seven points
Harrington, Thomas; Spradlin, Marcus
2017-07-01
Scattering amplitudes in planar super-Yang-Mills theory satisfy several basic physical and mathematical constraints, including physical constraints on their branch cut structure and various empirically discovered connections to the mathematics of cluster algebras. The power of the bootstrap program for amplitudes is inversely proportional to the size of the intersection between these physical and mathematical constraints: ideally we would like a list of constraints which determine scattering amplitudes uniquely. We explore this intersection quantitatively for two-loop six- and seven-point amplitudes by providing a complete taxonomy of the Gr(4, 6) and Gr(4, 7) cluster polylogarithm functions of [15] at weight 4.
Photon strength function deduced from photon scattering and neutron capture
Directory of Open Access Journals (Sweden)
Matic A.
2010-10-01
Full Text Available The dipole strength function of 78Se and 196Pt are investigated by two different experimental methods, capture of cold neutrons in 77Se and 195Pt and photon scattering experiments on 78Se and 196Pt. Considering the different ways of excitation, the strength function deduced from the results are expected to agree. The report shows the status of the data analysis and presents first preliminary results.
Point Scattered Function (PScF) for fast neutron radiography
Energy Technology Data Exchange (ETDEWEB)
Hassan, Mohamed H. [Nuclear and Radiation Engineering Department, Alexandria University, Alexandria 21544 (Egypt)], E-mail: mhmheg@yahoo.com
2009-08-01
Fast neutron radiography opened up a new range of possibilities to image extremely dense objects. The removal of the scattering effect is one of the most challenging problems in neutron imaging. Neutron scattering in fast neutron radiography did not receive much attention compared with X-ray and thermal neutron radiography. The purpose of this work is to investigate the behavior of the Point Scattered Function (PScF) as applied in fast neutron radiography. The PScF was calculated using MCNP as a spatial distribution of scattered neutrons over the detector surface for one emitting source element. Armament and explosives materials, namely, Rifle steel, brass, aluminum and trinitrotoluene (TNT) were simulated. Effect of various sample thickness and sample-to-detector distance were considered. Simulated sample geometries included a slab with varying thickness, a sphere with varying radii, and a cylinder with varying base radii. Different neutron sources, namely, Cf-252, DT as well as DD neutron sources were considered. Neutron beams with zero degree divergence angle; and beams with varying angles related to the normal to the source plane were simulated. Curve fitting of the obtained PScF, in the form of Gaussian function, were given to be used in future work using image restoration codes. Analytical representation of the height as well as the Full Width at Half Maximum (FWHM) of the obtained Gaussian functions eliminates the need to calculate the PScF for sample parameters that were not investigated in this study.
Intermediate scattering function of an anisotropic active Brownian particle
Kurzthaler, Christina; Leitmann, Sebastian; Franosch, Thomas
2016-10-01
Various challenges are faced when animalcules such as bacteria, protozoa, algae, or sperms move autonomously in aqueous media at low Reynolds number. These active agents are subject to strong stochastic fluctuations, that compete with the directed motion. So far most studies consider the lowest order moments of the displacements only, while more general spatio-temporal information on the stochastic motion is provided in scattering experiments. Here we derive analytically exact expressions for the directly measurable intermediate scattering function for a mesoscopic model of a single, anisotropic active Brownian particle in three dimensions. The mean-square displacement and the non-Gaussian parameter of the stochastic process are obtained as derivatives of the intermediate scattering function. These display different temporal regimes dominated by effective diffusion and directed motion due to the interplay of translational and rotational diffusion which is rationalized within the theory. The most prominent feature of the intermediate scattering function is an oscillatory behavior at intermediate wavenumbers reflecting the persistent swimming motion, whereas at small length scales bare translational and at large length scales an enhanced effective diffusion emerges. We anticipate that our characterization of the motion of active agents will serve as a reference for more realistic models and experimental observations.
Expansion of tabulated scattering matrices in generalized spherical functions
Mishchenko, Michael I.; Geogdzhayev, Igor V.; Yang, Ping
2016-11-01
An efficient way to solve the vector radiative transfer equation for plane-parallel turbid media is to Fourier-decompose it in azimuth. This methodology is typically based on the analytical computation of the Fourier components of the phase matrix and is predicated on the knowledge of the coefficients appearing in the expansion of the normalized scattering matrix in generalized spherical functions. Quite often the expansion coefficients have to be determined from tabulated values of the scattering matrix obtained from measurements or calculated by solving the Maxwell equations. In such cases one needs an efficient and accurate computer procedure converting a tabulated scattering matrix into the corresponding set of expansion coefficients. This short communication summarizes the theoretical basis of this procedure and serves as the user guide to a simple public-domain FORTRAN program.
Aerosol light scattering measurements as a function of relative humidity.
Day, D E; Malm, W C; Kreidenweis, S M
2000-05-01
The hygroscopic nature of atmospheric fine aerosol was investigated at a rural site in the Great Smoky Mountains National Park during July and August 1995. Passing the sample aerosol through an inlet, which housed an array of Perma Pure diffusion dryers, controlled the sample aerosol's relative humidity (RH). After conditioning the aerosol sample in the inlet, the light scattering coefficient and the aerosol size distribution were simultaneously measured. During this study, the conditioned aerosol's humidity ranged between 5% < RH < 95%. Aerosol response curves were produced using the ratio bspw/bspd; where bspw is the scattering coefficient measured at some RH greater than 20% and bspd is the scattering coefficient of the "dry" aerosol. For this work, any sample RH values below 15% were considered dry. Results of this investigation showed that the light scattering ratio increased continuously and smoothly over the entire range of relative humidity. The magnitude of the ratio at a particular RH value, however, varied considerably in time, particularly for RH values greater than approximately 60%. Curves of the scattering coefficient ratios as a function of RH were generated for each day and compared to the average 12-hour chemical composition of the aerosol. This comparison showed that for any particular RH value the ratio was highest during time periods of high sulfate concentrations and lowest during time periods of high soil or high organic carbon concentrations.
Evolution of the transfer function characterization of surface scatter phenomena
Harvey, James E.; Pfisterer, Richard N.
2016-09-01
Based upon the empirical observation that BRDF measurements of smooth optical surfaces exhibited shift-invariant behavior when plotted versus o , the original Harvey-Shack (OHS) surface scatter theory was developed as a scalar linear systems formulation in which scattered light behavior was characterized by a surface transfer function (STF) reminiscent of the optical transfer function (OTF) of modern image formation theory (1976). This shift-invariant behavior combined with the inverse power law behavior when plotting log BRDF versus log o was quickly incorporated into several optical analysis software packages. Although there was no explicit smooth-surface approximation in the OHS theory, there was a limitation on both the incident and scattering angles. In 1988 the modified Harvey-Shack (MHS) theory removed the limitation on the angle of incidence; however, a moderate-angle scattering limitation remained. Clearly for large incident angles the BRDF was no longer shift-invariant as a different STF was now required for each incident angle. In 2011 the generalized Harvey-Shack (GHS) surface scatter theory, characterized by a two-parameter family of STFs, evolved into a practical modeling tool to calculate BRDFs from optical surface metrology data for situations that violate the smooth surface approximation inherent in the Rayleigh-Rice theory and/or the moderate-angle limitation of the Beckmann-Kirchhoff theory. And finally, the STF can be multiplied by the classical OTF to provide a complete linear systems formulation of image quality as degraded by diffraction, geometrical aberrations and surface scatter effects from residual optical fabrication errors.
Generalized functions, volume 6 representation theory and automorphic functions
Gel′fand, I M; Pyatetskii-Shapiro, I I
2016-01-01
The first systematic theory of generalized functions (also known as distributions) was created in the early 1950s, although some aspects were developed much earlier, most notably in the definition of the Green's function in mathematics and in the work of Paul Dirac on quantum electrodynamics in physics. The six-volume collection, Generalized Functions, written by I. M. Gel′fand and co-authors and published in Russian between 1958 and 1966, gives an introduction to generalized functions and presents various applications to analysis, PDE, stochastic processes, and representation theory. The unif
Moskalensky, Alexander E.; Yurkin, Maxim A.; Konokhova, Anastasiya I.; Strokotov, Dmitry I.; Nekrasov, Vyacheslav M.; Chernyshev, Andrei V.; Tsvetovskaya, Galina A.; Chikova, Elena D.; Maltsev, Valeri P.
2013-01-01
We introduce a novel approach for determination of volume and shape of individual blood platelets modeled as an oblate spheroid from angle-resolved light scattering with flow-cytometric technique. The light-scattering profiles (LSPs) of individual platelets were measured with the scanning flow cytometer and the platelet characteristics were determined from the solution of the inverse light-scattering problem using the precomputed database of theoretical LSPs. We revealed a phenomenon of parameter compensation, which is partly explained in the framework of anomalous diffraction approximation. To overcome this problem, additional a priori information on the platelet refractive index was used. It allowed us to determine the size of each platelet with subdiffraction precision and independent of the particular value of the platelet aspect ratio. The shape (spheroidal aspect ratio) distributions of platelets showed substantial differences between native and activated by 10 μM adenosine diphosphate samples. We expect that the new approach may find use in hematological analyzers for accurate measurement of platelet volume distribution and for determination of the platelet activation efficiency.
Moskalensky, Alexander E; Yurkin, Maxim A; Konokhova, Anastasiya I; Strokotov, Dmitry I; Nekrasov, Vyacheslav M; Chernyshev, Andrei V; Tsvetovskaya, Galina A; Chikova, Elena D; Maltsev, Valeri P
2013-01-01
We introduce a novel approach for determination of volume and shape of individual blood platelets modeled as an oblate spheroid from angle-resolved light scattering with flow-cytometric technique. The light-scattering profiles (LSPs) of individual platelets were measured with the scanning flow cytometer and the platelet characteristics were determined from the solution of the inverse light-scattering problem using the precomputed database of theoretical LSPs. We revealed a phenomenon of parameter compensation, which is partly explained in the framework of anomalous diffraction approximation. To overcome this problem, additional a priori information on the platelet refractive index was used. It allowed us to determine the size of each platelet with subdiffraction precision and independent of the particular value of the platelet aspect ratio. The shape (spheroidal aspect ratio) distributions of platelets showed substantial differences between native and activated by 10 μM adenosine diphosphate samples. We expect that the new approach may find use in hematological analyzers for accurate measurement of platelet volume distribution and for determination of the platelet activation efficiency.
Transition probability functions for applications of inelastic electron scattering.
Löffler, Stefan; Schattschneider, Peter
2012-09-01
In this work, the transition matrix elements for inelastic electron scattering are investigated which are the central quantity for interpreting experiments. The angular part is given by spherical harmonics. For the weighted radial wave function overlap, analytic expressions are derived in the Slater-type and the hydrogen-like orbital models. These expressions are shown to be composed of a finite sum of polynomials and elementary trigonometric functions. Hence, they are easy to use, require little computation time, and are significantly more accurate than commonly used approximations.
The Appell function F1 and Regge string scattering amplitudes
Directory of Open Access Journals (Sweden)
Jen-Chi Lee
2014-12-01
Full Text Available We show that each 26D open bosonic Regge string scattering amplitude (RSSA can be expressed in terms of one single Appell function F1 in the Regge limit. This result enables us to derive infinite number of recurrence relations among RSSA at arbitrary mass levels, which are conjectured to be related to the known SL(5,C dynamical symmetry of F1. In addition, we show that these recurrence relations in the Regge limit can be systematically solved so that all RSSA can be expressed in terms of one amplitude. All these results are dual to high energy symmetries of fixed angle string scattering amplitudes discovered previously [4–8].
Cluster Functions and Scattering Amplitudes for Six and Seven Points
Harrington, Thomas
2015-01-01
Scattering amplitudes in planar super-Yang-Mills theory satisfy several basic physical and mathematical constraints, including physical constraints on their branch cut structure and various empirically discovered connections to the mathematics of cluster algebras. The power of the bootstrap program for amplitudes is inversely proportional to the size of the intersection between these physical and mathematical constraints: ideally we would like a list of constraints which determine scattering amplitudes uniquely. We explore this intersection quantitatively for two-loop six- and seven-point amplitudes by providing a complete taxonomy of the Gr(4,6) and Gr(4,7) cluster polylogarithm functions of arXiv:1401.6446 at weight 4.
Finite volume treatment of $\\pi\\pi$ scattering in the $\\rho$ channel
Albaladejo, M; Oller, J A; Roca, L
2013-01-01
We make a theoretical study of $\\pi\\pi$ scattering with quantum numbers $J^{PC}=1^{--}$ in a finite box. To calculate physical observables for infinite volume from lattice QCD, the finite box dependence of the potentials is not usually considered. We quantify such effects by means of two different approaches for vector-isovector $\\pi\\pi$ scattering based on Unitarized Chiral Perturbation Theory results: the Inverse Amplitude Method and another one based on the $N/D$ method. We take into account finite box effects stemming from higher orders through loops in the crossed $t,u-$channels as well as from the renormalization of the coupling constants. The main conclusion is that for $\\pi\\pi$ phase shifts in the isovector channel one can safely apply L\\"uscher based methods for finite box sizes of $L$ greater than $2 m_\\pi^{-1}$.
Fitting Green’s Function FFT Acceleration Applied to Anisotropic Dielectric Scattering Problems
Directory of Open Access Journals (Sweden)
Shu-Wen Chen
2015-01-01
Full Text Available A volume integral equation based fast algorithm using the Fast Fourier Transform of fitting Green’s function (FG-FFT is proposed in this paper for analysis of electromagnetic scattering from 3D anisotropic dielectric objects. For the anisotropic VIE model, geometric discretization is still implemented by tetrahedron cells and the Schaubert-Wilton-Glisson (SWG basis functions are also used to represent the electric flux density vectors. Compared with other Fast Fourier Transform based fast methods, using fitting Green’s function technique has higher accuracy and can be applied to a relatively coarse grid, so the Fast Fourier Transform of fitting Green’s function is selected to accelerate anisotropic dielectric model of volume integral equation for solving electromagnetic scattering problems. Besides, the near-field matrix elements in this method are used to construct preconditioner, which has been proved to be effective. At last, several representative numerical experiments proved the validity and efficiency of the proposed method.
Ulku, Huseyin Arda
2014-07-06
Effects of material nonlinearities on electromagnetic field interactions become dominant as field amplitudes increase. A typical example is observed in plasmonics, where highly localized fields “activate” Kerr nonlinearities. Naturally, time domain solvers are the method of choice when it comes simulating these nonlinear effects. Oftentimes, finite difference time domain (FDTD) method is used for this purpose. This is simply due to the fact that explicitness of the FDTD renders the implementation easier and the material nonlinearity can be easily accounted for using an auxiliary differential equation (J.H. Green and A. Taflove, Opt. Express, 14(18), 8305-8310, 2006). On the other hand, explicit marching on-in-time (MOT)-based time domain integral equation (TDIE) solvers have never been used for the same purpose even though they offer several advantages over FDTD (E. Michielssen, et al., ECCOMAS CFD, The Netherlands, Sep. 5-8, 2006). This is because explicit MOT solvers have never been stabilized until not so long ago. Recently an explicit but stable MOT scheme has been proposed for solving the time domain surface magnetic field integral equation (H.A. Ulku, et al., IEEE Trans. Antennas Propag., 61(8), 4120-4131, 2013) and later it has been extended for the time domain volume electric field integral equation (TDVEFIE) (S. B. Sayed, et al., Pr. Electromagn. Res. S., 378, Stockholm, 2013). This explicit MOT scheme uses predictor-corrector updates together with successive over relaxation during time marching to stabilize the solution even when time step is as large as in the implicit counterpart. In this work, an explicit MOT-TDVEFIE solver is proposed for analyzing electromagnetic wave interactions on scatterers exhibiting Kerr nonlinearity. Nonlinearity is accounted for using the constitutive relation between the electric field intensity and flux density. Then, this relation and the TDVEFIE are discretized together by expanding the intensity and flux - sing half
Two-Particle Elastic Scattering in a Finite Volume Including QED
Beane, Silas R
2014-01-01
The presence of long-range interactions violates a condition necessary to relate the energy of two particles in a finite volume to their S-matrix elements in the manner of Luscher. While in infinite volume, QED contributions to low-energy charged particle scattering must be resummed to all orders in perturbation theory (the Coulomb ladder diagrams), in a finite volume the momentum operator is gapped, allowing for a perturbative treatment. The leading QED corrections to the two-particle finite-volume energy quantization condition below the inelastic threshold, as well as approximate formulas for energy eigenvalues, are obtained. In particular, we focus on two spinless hadrons in the A1+ irreducible representation of the cubic group, and truncate the strong interactions to the s-wave. These results are necessary for the analysis of Lattice QCD+QED calculations of charged-hadron interactions, and can be straightforwardly generalized to other representations of the cubic group, to hadrons with spin, and to includ...
Finite volume treatment of pi pi scattering and limits to phase shifts extraction from lattice QCD
Albaladejo, M; Oset, E; Rios, G; Roca, L
2012-01-01
We study theoretically the effects of finite volume for pipi scattering in order to extract physical observables for infinite volume from lattice QCD. We compare three different approaches for pipi scattering (lowest order Bethe-Salpeter approach, N/D and inverse amplitude methods) with the aim to study the effects of the finite size of the box in the potential of the different theories, specially the left-hand cut contribution through loops in the crossed t,u-channels. We quantify the error made by neglecting these effects in usual extractions of physical observables from lattice QCD spectra. We conclude that for pipi phase-shifts in the scalar-isoscalar channel up to 800 MeV this effect is negligible for box sizes bigger than 2.5m_pi^-1 and of the order of 5% at around 1.5-2m_pi^-1. For isospin 2 the finite size effects can reach up to 10% for that energy. We also quantify the error made when using the standard Luscher method to extract physical observables from lattice QCD, which is widely used in the lite...
DEFF Research Database (Denmark)
Simonsen, Sebastian Bjerregaard; Sørensen, Louise Sandberg
2017-01-01
Long-term observations of surface elevation change of the Greenland ice sheet (GrIS) is of utmost importance when assessing the state of the ice sheet. Satellite radar altimetry offers a long time series of data over the GrIS, starting with ERS-1 in 1991. ESA's Cryosat-2 mission, launched in 2010...... waveform parameters to be applicable for correcting for changes in volume scattering. The best results in the Synthetic Aperture Radar Interferometric mode area of the GrIS are found when applying only the backscatter correction, whereas the best result in the Low Resolution Mode area is obtained by only...... applying a leading edge width correction. Using this approach to correct for the scattering properties, a volume loss of −292±38 km3 yr −1 is found for the GrIS for the time span November 2010 until November 2014. The inclusion of waveform parameter corrections and improved relocation for the GrIS, helps...
Pyramidal ice crystal scattering phase functions and concentric halos
Directory of Open Access Journals (Sweden)
C. Liu
Full Text Available Phase functions have been calculated using the Monte Carlo/geometric ray tracing method for single hexagonal pyramidal ice crystals (such as solid and hollow bullets randomly oriented in space and horizontal plane, in order to study the concentric halo formations. Results from three dimensional model calculations show that 9° halo can be as bright as the common 22° halo for pyramidal angle of 28°, and the 18°, 20°, 24° and 35° halos cannot be seen due to the strong 22° halo domination in the scattering phase function between 18° and 35°. For solid pyramidal ice crystals randomly oriented horizontally, the 35° arc can be produced and its intensity depends on the incident ray solar angle and the particle aspect ratio.
Algorithms and computer codes for atomic and molecular quantum scattering theory. Volume I
Energy Technology Data Exchange (ETDEWEB)
Thomas, L. (ed.)
1979-01-01
The goals of this workshop are to identify which of the existing computer codes for solving the coupled equations of quantum molecular scattering theory perform most efficiently on a variety of test problems, and to make tested versions of those codes available to the chemistry community through the NRCC software library. To this end, many of the most active developers and users of these codes have been invited to discuss the methods and to solve a set of test problems using the LBL computers. The first volume of this workshop report is a collection of the manuscripts of the talks that were presented at the first meeting held at the Argonne National Laboratory, Argonne, Illinois June 25-27, 1979. It is hoped that this will serve as an up-to-date reference to the most popular methods with their latest refinements and implementations.
A compilation of structure functions in deep inelastic scattering
Gehrmann, T; Whalley, M R
1999-01-01
A compilation of all the available data on the unpolarized structure functions F/sub 2/ and xF/sub 3/, R=( sigma /sub L// sigma /sub T/), the virtual photon asymmetries A/sub 1/ and A/sub 2/ and the polarized structure functions g/sub 1/ and g/sub 2/, from deep inelastic lepton scattering off protons, deuterium and nuclei is presented. The relevant experiments at CERN, DESY, Fermilab and SLAC from 1991, the date of our earlier review, to the present day are covered. A brief general theoretical introduction is given followed by the data presented both in tabular and graphical form and, for the F/sub 2/ and XF/sub 3/ data, the predictions based on the MRST98 and CTEQ4 parton distribution functions are also displayed. All the data in this review, together with data on a wide variety of other reactions, can be found in and retrieved from the Durham-RAL HEP Databases on the World-Wide-Web (http://durpdg.dur.ac.uk/HEPDATA). (76 refs).
Kashima, Susumu; Nishihara, Minoru; Takemoto, Yoshihiro; Osawa, Toshihiko
1990-09-01
The laser scattering characteristics from tissue microvasculature have been made clear by means of theoretical and experimental approaches. Our results show that the integrated intensity of the power spectrum correlates linearly with the volume of red blood cells in a given tissue provided the average collision number (\\bar{m}) between photons and moving red blood cells is less than unity. Also, the integrated intensity of the power spectrum is proportional to tissue blood volume if the density of red blood cells in blood (hematocrit) is constant.
Finite volume effects in pion-kaon scattering and reconstruction of the kappa(800) resonance
Döring, M
2011-01-01
Simulating the kappa(800) on the lattice is a challenging task that starts to become feasible due to the rapid progress in recent-years lattice QCD calculations. As the resonance is broad, special attention to finite-volume effects has to be paid, because no sharp resonance signal as from avoided level crossing can be expected. In the present article, we investigate the finite volume effects in the framework of unitarized chiral perturbation theory using next-to-leading order terms. After a fit to meson-meson partial wave data, lattice levels for piK scattering are predicted. In addition, levels are shown for the quantum numbers in which the sigma(600), f_0(980), a_0(980), phi(1020), K*(892), and rho(770) appear, as well as the repulsive channels. Methods to extract the kappa(800) signal from the lattice spectrum are presented. Using pseudo-data, we estimate the precision that lattice data should have to allow for a clear-cut extraction of this resonance. To put the results into context, in particular the req...
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Meincke, Peter; Breinbjerg, Olav
2007-01-01
is applied to transform the VSIE into a system of linear equations. The higher-order MoM provides significant reduction in the number of unknowns in comparison with standard MoM formulations using low-order basis functions, such as RWG functions. Due to the orthogonal nature of the higher-order Legendre......The problem of electromagnetic scattering by composite metallic and dielectric objects is solved using the coupled volume-surface integral equation (VSIE). The method of moments (MoM) based on higher-order hierarchical Legendre basis functions and higher-order curvilinear geometrical elements...
Functions and the Volume of Vases
McCoy, Ann C.; Barger, Rita H.; Barnett, Joann; Combs, Emily
2012-01-01
Functions are one of the most important and powerful tools in mathematics because they allow the symbolic, visual, and verbal representation of relationships between variables. The power of functions, as well as the numerous real-world uses of functions, make them an important part of the development of algebraic reasoning in the middle grades.…
Scattering amplitudes over finite fields and multivariate functional reconstruction
Peraro, Tiziano
2016-01-01
Several problems in computer algebra can be efficiently solved by reducing them to calculations over finite fields. In this paper, we describe an algorithm for the reconstruction of multivariate polynomials and rational functions from their evaluation over finite fields. Calculations over finite fields can in turn be efficiently performed using machine-size integers in statically-typed languages. We then discuss the application of the algorithm to several techniques related to the computation of scattering amplitudes, such as the four- and six-dimensional spinor-helicity formalism, tree-level recursion relations, and multi-loop integrand reduction via generalized unitarity. The method has good efficiency and scales well with the number of variables and the complexity of the problem. As an example combining these techniques, we present the calculation of full analytic expressions for the two-loop five-point on-shell integrands of the maximal cuts of the planar penta-box and the non-planar double-pentagon topol...
Scattering amplitudes over finite fields and multivariate functional reconstruction
Peraro, Tiziano
2016-12-01
Several problems in computer algebra can be efficiently solved by reducing them to calculations over finite fields. In this paper, we describe an algorithm for the reconstruction of multivariate polynomials and rational functions from their evaluation over finite fields. Calculations over finite fields can in turn be efficiently performed using machine-size integers in statically-typed languages. We then discuss the application of the algorithm to several techniques related to the computation of scattering amplitudes, such as the four- and six-dimensional spinor-helicity formalism, tree-level recursion relations, and multi-loop integrand reduction via generalized unitarity. The method has good efficiency and scales well with the number of variables and the complexity of the problem. As an example combining these techniques, we present the calculation of full analytic expressions for the two-loop five-point on-shell integrands of the maximal cuts of the planar penta-box and the non-planar double-pentagon topologies in Yang-Mills theory, for a complete set of independent helicity configurations.
Scattering amplitudes over finite fields and multivariate functional reconstruction
Energy Technology Data Exchange (ETDEWEB)
Peraro, Tiziano [Higgs Centre for Theoretical Physics,School of Physics and Astronomy, The University of Edinburgh,James Clerk Maxwell Building, Peter Guthrie Tait Road, Edinburgh EH9 3FD (United Kingdom)
2016-12-07
Several problems in computer algebra can be efficiently solved by reducing them to calculations over finite fields. In this paper, we describe an algorithm for the reconstruction of multivariate polynomials and rational functions from their evaluation over finite fields. Calculations over finite fields can in turn be efficiently performed using machine-size integers in statically-typed languages. We then discuss the application of the algorithm to several techniques related to the computation of scattering amplitudes, such as the four- and six-dimensional spinor-helicity formalism, tree-level recursion relations, and multi-loop integrand reduction via generalized unitarity. The method has good efficiency and scales well with the number of variables and the complexity of the problem. As an example combining these techniques, we present the calculation of full analytic expressions for the two-loop five-point on-shell integrands of the maximal cuts of the planar penta-box and the non-planar double-pentagon topologies in Yang-Mills theory, for a complete set of independent helicity configurations.
Extraction of information about periodic orbits from scattering functions
Bütikofer, T; Seligman, T H; Bütikofer, Thomas; Jung, Christof; Seligman, Thomas H.
1999-01-01
As a contribution to the inverse scattering problem for classical chaotic systems, we show that one can select sequences of intervals of continuity, each of which yields the information about period, eigenvalue and symmetry of one unstable periodic orbit.
Quasiclassical Green function in an external field and small-angle scattering
Lee, R N; Strakhovenko, V M
1999-01-01
The quasiclassical Green functions of the Dirac and Klein-Gordon equations in the external electric field are obtained with the first correction taken into account. The relevant potential is assumed to be localized, while its spherical symmetry is not required. Using these Green functions, the corresponding wave functions are found in the approximation similar to the Furry-Sommerfeld-Maue approximation. It is shown that the quasiclassical Green function does not coincide with the Green function obtained in the eikonal approximation and has a wider region of applicability. It is illustrated by the calculation of the small-angle scattering amplitude for a charged particle and the forward photon scattering amplitude. For charged particles, the first correction to the scattering amplitude in the non-spherically symmetric potential is found. This correction is proportional to the scattering angle. The real part of the amplitude of forward photon scattering in a screened Coulomb potential is obtained.
Analytic height correlation function of rough surfaces derived from light scattering
Zamani, M; Fazeli, S M; Downer, M C; Jafari, G R
2015-01-01
We obtain an analytic expression for the height correlation function of a rough surface based on the inverse wave scattering method of Kirchhoff theory. The expression directly relates the height correlation function to diffuse scattered intensity. We test the solution by measuring the angular distribution of light scattered from rough silicon surfaces, solving for the height correlation functions, and comparing them to functions derived from AFM measurements. The results show good agreement. The advantages of this method are its accurate analytical equation for the height correlation function and the simplicity of the experimental setup required to measure it.
Directory of Open Access Journals (Sweden)
Qinghua Xie
2017-01-01
Full Text Available Recently, a general polarimetric model-based decomposition framework was proposed by Chen et al., which addresses several well-known limitations in previous decomposition methods and implements a simultaneous full-parameter inversion by using complete polarimetric information. However, it only employs four typical models to characterize the volume scattering component, which limits the parameter inversion performance. To overcome this issue, this paper presents two general polarimetric model-based decomposition methods by incorporating the generalized volume scattering model (GVSM or simplified adaptive volume scattering model, (SAVSM proposed by Antropov et al. and Huang et al., respectively, into the general decomposition framework proposed by Chen et al. By doing so, the final volume coherency matrix structure is selected from a wide range of volume scattering models within a continuous interval according to the data itself without adding unknowns. Moreover, the new approaches rely on one nonlinear optimization stage instead of four as in the previous method proposed by Chen et al. In addition, the parameter inversion procedure adopts the modified algorithm proposed by Xie et al. which leads to higher accuracy and more physically reliable output parameters. A number of Monte Carlo simulations of polarimetric synthetic aperture radar (PolSAR data are carried out and show that the proposed method with GVSM yields an overall improvement in the final accuracy of estimated parameters and outperforms both the version using SAVSM and the original approach. In addition, C-band Radarsat-2 and L-band AIRSAR fully polarimetric images over the San Francisco region are also used for testing purposes. A detailed comparison and analysis of decomposition results over different land-cover types are conducted. According to this study, the use of general decomposition models leads to a more accurate quantitative retrieval of target parameters. However, there
Time-Domain Volume Integral Equation for TM-Case Scattering from Nonlinear Penetrable Objects
Institute of Scientific and Technical Information of China (English)
WANG Jianguo; Eric Michielssen
2001-01-01
This paper presents the time-domainvolume integral equation (TDVIE) method to analyzescattering from nonlinear penetrable objects, whichare illuminated by the transverse magnetic (TM) in-cident pulse. The time-domain volume integral equa-tion is formulated in terms of two-dimensional (2D)Green's function, and solved by using the march-on-in time (MOT) technique. Some numerical results aregiven to validate this method, and comparisons aremade with the results obtained by using the finite-difference time-domain (FDTD) method.
Generalized functions, volume 3 theory of differential equations
Gel′fand, I M
2016-01-01
The first systematic theory of generalized functions (also known as distributions) was created in the early 1950s, although some aspects were developed much earlier, most notably in the definition of the Green's function in mathematics and in the work of Paul Dirac on quantum electrodynamics in physics. The six-volume collection, Generalized Functions, written by I. M. Gel′fand and co-authors and published in Russian between 1958 and 1966, gives an introduction to generalized functions and presents various applications to analysis, PDE, stochastic processes, and representation theory. In Volum
Determination of the autonomously functioning volume of the thyroid
Energy Technology Data Exchange (ETDEWEB)
Emrich, D.; Erlenmaier, U.; Pohl, M.; Luig, H. (Goettingen Univ. (Germany). Abt. fuer Nuklearmedizin)
1993-05-01
The aim of this work was to determine the autonomously functioning volume in euthyroid and hyperthyroid goitres for prognostic and therapeutic pruposes. To this end, various groups of patients were selected: Individuals without evidence of thyroid disease, euthyroid patients with diffuse goitre of normal structure and function, euthyroid patients with evidence of autonomy and patients with hyperthyroidism due to autonomy. In all of them the thyroid uptake of Technetium-99m was determined under exogeneous suppression (TcU[sub s]) in the euthyroid state and under endogenous suppression (TcU) in the hyperthyroid state. It was demonstrated that: 1. In patients with unifocal autonomy the TcU[sub s] and TcU correlated linearly with the autonomous volume delineated and measured by sonography. 2. A nearly identical result was obtained if the mean autonomous volume in individuals without thyroid disease of 2.2[+-]1.1 ml calculated by TcU[sub s]/TcU x total thyroid volume was used as a basis. 3. The critical autonomous volume, i.e. the volume at which hyperthryroidism will occur, was found to be 16 ml at a cumulated sensitivity and specificity of >0.9. The method can be used to select patients for definitive treatment before hyperthryroidism occurs and to measure the autonomously functioning volume independent of its distribution within the thyroid for treatment with radioiodine. The method is easy to perform and is also an example of how a relative parameter of a function can be converted into an absolute parameter of a functioning volume. (orig.).
Directory of Open Access Journals (Sweden)
P. V. Ponomarenko
2009-11-01
Full Text Available Ionospheric E×B plasma drift velocities derived from the Super Dual Auroral Radar Network (SuperDARN Doppler data exhibit systematically smaller (by 20–30% magnitudes than those measured by the Defence Meteorological Satellites Program (DMSP satellites. A part of the disagreement was previously attributed to the change in the E/B ratio due to the altitude difference between the satellite orbit and the location of the effective scatter volume for the radar signals. Another important factor arises from the free-space propagation assumption used in converting the measured Doppler frequency shift into the line-of-sight velocity. In this work, we have applied numerical ray-tracing to identify the location of the effective scattering volume of the ionosphere and to estimate the ionospheric refractive index. The simulations show that the major contribution to the radar echoes should be provided by the Pedersen and/or escaping rays that are scattered in the vicinity of the F-layer maximum. This conclusion is supported by a statistical analysis of the experimental elevation angle data, which have a signature consistent with scattering from the F-region peak. A detailed analysis of the simulations has allowed us to propose a simple velocity correction procedure, which we have successfully tested against the SuperDARN/DMSP comparison data set.
A Study on Ionospheric HF Channel with Bitemporal Response and Scattering Function
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
At first the bitemporal response method is introduced to solve the scattering function of the ionospheric channel. We can get the scattering function as a function of the group path time delay and Doppler frequency. Thus Doppler effect resulting from the continuous movement of the ionosphere is analyzed to study the characteristics of the various ionospheric irregularities and disturbance. many possible problems and correction are researched lastly.
Extraction of structure functions for lepton-nucleus scattering in the quasi-elastic region
Kim, K. S.; Kim, Hungchong; Cheoun, Myung-Ki; So, W. Y.
2016-12-01
Within the framework of a relativistic single-particle model, we calculate inclusive electron-nucleus scattering by electromagnetic current, and neutrino-nucleus scattering by neutral and charged current in the quasi-elastic region. The longitudinal, the transverse, and the transverse-interference structure functions are extracted from the theoretical cross section by using the Rosenbluth separation method at fixed momentum transfer and scattering angle and then compared with each other from the viewpoint of these current interactions. The position of peak for the electron scattering shifts to higher energy transfer than that for the neutrino scattering. The axial and pseudoscalar terms turn out to play an important role in the neutrino-nucleus scattering.
Bagci, Hakan
2014-01-06
Time domain integral equation (TDIE) solvers represent an attractive alternative to finite difference (FDTD) and finite element (FEM) schemes for analyzing transient electromagnetic interactions on composite scatterers. Current induced on a scatterer, in response to a transient incident field, generates a scattered field. First, the scattered field is expressed as a spatio-temporal convolution of the current and the Green function of the background medium. Then, a TDIE is obtained by enforcing boundary conditions and/or fundamental field relations. TDIEs are often solved for the unknown current using marching on-in-time (MOT) schemes. MOT-TDIE solvers expand the current using local spatio-temporal basis functions. Inserting this expansion into the TDIE and testing the resulting equation in space and time yields a lower triangular system of equations (termed MOT system), which can be solved by marching in time for the coefficients of the current expansion. Stability of the MOT scheme often depends on how accurately the spatio-temporal convolution of the current and the Green function is discretized. In this work, band-limited prolate-based interpolation functions are used as temporal bases in expanding the current and discretizing the spatio-temporal convolution. Unfortunately, these functions are two sided, i.e., they require ”future” current samples for interpolation, resulting in a non-causal MOT system. To alleviate the effect of non-causality and restore the ability to march in time, an extrapolation scheme can be used to estimate the future values of the currents from their past values. Here, an accurate, stable and band-limited extrapolation scheme is developed for this purpose. This extrapolation scheme uses complex exponents, rather than commonly used harmonics, so that propagating and decaying mode fields inside the dielectric scatterers are accurately modeled. The resulting MOT scheme is applied to solving the time domain volume integral equation (VIE
Functional Imaging of Tissue Morphology with Polarized Light Scattering Spectroscopy
Backman, Vadim
2001-03-01
We report a new imaging technique to study the morphology of living epithelial cells in vivo. The method is based on light scattering spectroscopy with polarized light (PLSS) and makes it possible to distinguish between single backscattering from epithelial cell nuclei and multiply scattered light. The spectrum of the single backscattering component is further analyzed to provide quantitative histological information about the epithelial cells such as the size distribution, refractive index, and chromatin content of the cell nuclei. The measurement of cell nuclear morphology is crucial for detection and diagnosis of cancerous and precancerous conditions in many human tissues. The method was successfully applied to image precancerous regions of several tissues. Clinical studies in five organs (esophagus, colon, bladder, oral cavity, and uterine cervix) showed the generality and efficacy of the technique.
Childhood Cumulative Risk Exposure and Adult Amygdala Volume and Function.
Evans, Gary W; Swain, James E; King, Anthony P; Wang, Xin; Javanbakht, Arash; Ho, S Shaun; Angstadt, Michael; Phan, K Luan; Xie, Hong; Liberzon, Israel
2016-06-01
Considerable work indicates that early cumulative risk exposure is aversive to human development, but very little research has examined the neurological underpinnings of these robust findings. This study investigates amygdala volume and reactivity to facial stimuli among adults (mean 23.7 years of age, n = 54) as a function of cumulative risk exposure during childhood (9 and 13 years of age). In addition, we test to determine whether expected cumulative risk elevations in amygdala volume would mediate functional reactivity of the amygdala during socioemotional processing. Risks included substandard housing quality, noise, crowding, family turmoil, child separation from family, and violence. Total and left hemisphere adult amygdala volumes were positively related to cumulative risk exposure during childhood. The links between childhood cumulative risk exposure and elevated amygdala responses to emotionally neutral facial stimuli in adulthood were mediated by the corresponding amygdala volumes. Cumulative risk exposure in later adolescence (17 years of age), however, was unrelated to subsequent adult amygdala volume or function. Physical and socioemotional risk exposures early in life appear to alter amygdala development, rendering adults more reactive to ambiguous stimuli such as neutral faces. These stress-related differences in childhood amygdala development might contribute to the well-documented psychological distress as a function of early risk exposure.
Sayed, Sadeed Bin
2015-05-05
A time domain electric field volume integral equation (TD-EFVIE) solver is proposed for characterizing transient electromagnetic wave interactions on high-contrast dielectric scatterers. The TD-EFVIE is discretized using the Schaubert- Wilton-Glisson (SWG) and approximate prolate spherical wave (APSW) functions in space and time, respectively. The resulting system of equations can not be solved by a straightforward application of the marching on-in-time (MOT) scheme since the two-sided APSW interpolation functions require the knowledge of unknown “future” field samples during time marching. Causality of the MOT scheme is restored using an extrapolation technique that predicts the future samples from known “past” ones. Unlike the extrapolation techniques developed for MOT schemes that are used in solving time domain surface integral equations, this scheme trains the extrapolation coefficients using samples of exponentials with exponents on the complex frequency plane. This increases the stability of the MOT-TD-EFVIE solver significantly, since the temporal behavior of decaying and oscillating electromagnetic modes induced inside the scatterers is very accurately taken into account by this new extrapolation scheme. Numerical results demonstrate that the proposed MOT solver maintains its stability even when applied to analyzing wave interactions on high-contrast scatterers.
Magnetic two-photon scattering and two-photon emission - Cross sections and redistribution functions
Alexander, S. G.; Meszaros, P.
1991-01-01
The magnetic two-photon scattering cross section is discussed within the framework of QED, and the corresponding scattering redistribution function for this process and its inverse, as well as the scattering source function are calculated explicitly. In a similar way, the magnetic two-photon emission process which follows the radiative excitation of Landau levels above ground is calculated. The two-photon scattering and two-photon emission are of the same order as the single-photon magnetic scattering. All three of these processes, and in optically thick cases also their inverses, are included in radiative transport calculations modeling accreting pulsars and gamma-ray bursters. These processes play a prominent role in determining the relative strength of the first two cyclotron harmonics, and their effects extend also to the higher harmonics.
Multichannel forward scattering meter for oceanography.
McCluney, W R
1974-03-01
An instrument was designed and built that measures the light scattered at several angles in the forward direction simultaneously. The instrument relies on an optical multiplexing technique for frequency encoding of the different channels suitable for detection by a single photodetector. A Mie theory computer program was used to calculate the theoretical volume scattering function for a suspension of polystyrene latex spheres. The agreement between the theoretical and experimental volume scattering functions is taken as a verification of the calibration technique used.
Koutsopoulos, S; van der Oost, J; Norde, W
2005-01-01
The dynamic behavior of an endoglucanase from the hyperthermophilic microorganism Pyrococcus furiosus was investigated using elastic neutron scattering. The temperature dependence of the atomic motions was correlated with conformational. and functional characteristics of the enzyme. The onset of
Koutsopoulos, S.; Oost, van der J.; Norde, W.
2005-01-01
The dynamic behavior of an endoglucanase from the hyperthermophilic microorganism Pyrococcus furiosus was investigated using elastic neutron scattering. The temperature dependence of the atomic motions was correlated with conformational and functional characteristics of the enzyme. The onset of
QCD analysis of neutrino charged current structure function F2 in deep inelastic scattering
Saleem, M.; Aleem, F.
1985-08-01
An analytic expression for the neutrino charged current structure function F2 (x, Q2) in deep inelastic scattering, consistent with quantum chromodynamics, is proposed. The calculated results are in good agreement with experiment.
A First Measurement of Low x Low $Q^{2}$ Structure Functions in Neutrino Scattering
Fleming, B T; Alton, A; Arroyo, C G; Avvakumov, S; De Barbaro, L; De Barbaro, P; Bazarko, A O; Bernstein, R H; Bodek, Arie; Bolton, T; Brau, J E; Buchholz, D; Budd, H S; Bugel, L; Conrad, J; Drucker, R B; Formaggio, J A; Frey, R; Goldman, J; Goncharov, M; Harris, D A; Johnson, R A; Kim, J H; King, B J; Kinnel, T; Koutsoliotas, S; Lamm, M J; Marsh, W; Mason, D; McFarland, K S; McNulty, C; Mishra, S R; Naples, D; Nienaber, P; Romosan, A; Sakumoto, W K; Schellman, H; Sciulli, F J; Seligman, W G; Shaevitz, M H; Smith, W H; Spentzouris, P; Stern, E G; Suwonjandee, N; Vaitaitis, A G; Vakili, M; Yang, U K; Yu, J; Zeller, G P; Zimmerman, E D
2001-01-01
A new structure function analysis of CCFR deep inelastic nu-N and nubar-N scattering data is presented for previously unexplored kinematic regions down to Bjorken x=0.0045 and Q^2=0.3 GeV^2. Comparisons to charged lepton scattering data from NMC and E665 experiments are made and the behavior of the structure function F2_nu is studied in the limit Q^2 -> 0.
Representation theorems and Green's function retrieval for scattering in acoustic media.
Vasconcelos, Ivan; Snieder, Roel; Douma, Huub
2009-09-01
Reciprocity theorems for perturbed acoustic media are provided in the form of convolution- and correlation-type theorems. These reciprocity relations are particularly useful in the general treatment of both forward and inverse-scattering problems. Using Green's functions to describe perturbed and unperturbed waves in two distinct wave states, representation theorems for scattered waves are derived from the reciprocity relations. While the convolution-type theorems can be manipulated to obtain scattering integrals that are analogous to the Lippmann-Schwinger equation, the correlation-type theorems can be used to retrieve the scattering response of the medium by cross correlations. Unlike previous formulations of Green's function retrieval, the extraction of scattered-wave responses by cross correlations does not require energy equipartitioning. Allowing for uneven energy radiation brings experimental advantages to the retrieval of fields scattered by remote lossless and/or attenuative scatterers. These concepts are illustrated with a number of examples, including analytic solutions to a one-dimensional scattering problem, and a numerical example in the context of seismic waves recorded on the ocean bottom.
Radiotherapy Dose-Volume Effects on Salivary Gland Function
Deasy, Joseph O.; Moiseenko, Vitali; Marks, Lawrence; Chao, K. S. Clifford; Nam, Jiho; Eilsbruch, Avraham
2013-01-01
Publications relating parotid dose-volume characteristics to radiotherapy-induced salivary toxicity were reviewed. Late salivary dysfunction has been correlated to the mean parotid gland dose, with recovery occurring with time. Severe xerostomia (defined as long-term salivary function of <25% of baseline) is usually avoided if at least one parotid gland is spared to a mean dose of less than ≈20 Gy or if both glands are spared to less than ≈25 Gy (mean dose). For complex, partial-volume RT patterns (e.g., intensity-modulated radiotherapy), each parotid mean dose should be kept as low as possible, consistent with the desired clinical target volume coverage. A lower parotid mean dose usually results in better function. Submandibular gland sparing also significantly decreases the risk of xerostomia. The currently available predictive models are imprecise, and additional study is required to identify more accurate models of xerostomia risk. PMID:20171519
Coefficients of the legendre and fourier series for the scattering functions of spherical particles.
Dave, J V
1970-08-01
Results of computations are presented to show the variations of coefficients of four different Legendre series, one for each of the four scattering functions needed in describing directional dependence of the radiation scattered by a sphere. Values of the size parameter (x) covered for this purpose vary from 0.01 to 100.0. An adequate representation of the entire scattering function vs scattering angle curve is obtained after making use of about 2x + 10 terms of the series. It is shown that a section of a scattering function vs scattering angle curve can be adequately represented by a fourier series with less than 2x + 10 terms. The exact number of terms required for this purpose depends upon values of the size parameter and refractive index, as well as upon the values of the scattering angles defining the section under study. Necessary expressions for coefficients of such fourier series are derived with the help of the addition theorem of spherical harmonics.
Sato, Takao M.; Satoh, T.; Kasaba, Y.
2010-10-01
It is essential to know scattering properties (e.g., scattering phase function) of clouds for determination of vertical cloud structure. However, we cannot derive those from ground-based and Earth-orbit observations because of the limitation of solar phase angle as viewed from the Earth. Then, most previous studies have used the scattering phase function deduced from the Pioneer 10/IPP data (blue: 440 nm, red: 640nm) [Tomasko et al., 1978]. There are two shortcomings in the Pioneer scattering phase function. One is that we have to use this scattering phase function at red as a substitute for analyses of imaging photometry using CH4 bands (center: 727 and 890 nm), although clouds should have wavelength dependency. The other is that the red pass band of IPP was so broad (595-720 nm) that this scattering phase function in red just show wavelength-averaged scattering properties of clouds. To provide a new reference scattering phase function with wavelength dependency, we have analyzed the Cassini/ISS data in BL1 (451 nm), CB1 (619 nm), CB2 (750 nm), and CB3 (938 nm) over wide solar phase angles (3-141 degrees) during its Jovian flyby in 2000-2001. A simple cloud model which consists of a thin stratospheric haze, a semi-infinite cloud, and an intervening Rayleigh gas layers is adopted. Applying Mie theory to scattering by clouds, we deduce the scattering phase function of cloud and effective particle size in the South Tropical Zone. When we use the nominal value of reflective index for ammonia ice (Martonchik et al., 1984), we cannot obtain reasonable fit to the observed limb-darkening profiles. This would imply that we should consider possible effects on the impurity and/or the nonsphericiy of clouds. In this presentation, we will show detail model description and these results. Finally, we discuss scattering properties of clouds through comparison with previous works.
Generalized functions, volume 5 integral geometry and representation theory
Gel′fand, I M; Vilenkin, N Ya; Vilenkin, N Ya
2016-01-01
The first systematic theory of generalized functions (also known as distributions) was created in the early 1950s, although some aspects were developed much earlier, most notably in the definition of the Green's function in mathematics and in the work of Paul Dirac on quantum electrodynamics in physics. The six-volume collection, Generalized Functions, written by I. M. Gel′fand and co-authors and published in Russian between 1958 and 1966, gives an introduction to generalized functions and presents various applications to analysis, PDE, stochastic processes, and representation theory. The unif
Generalized functions, volume 4 applications of harmonic analysis
Gel′fand, I M; Vilenkin, N Ya
2016-01-01
The first systematic theory of generalized functions (also known as distributions) was created in the early 1950s, although some aspects were developed much earlier, most notably in the definition of the Green's function in mathematics and in the work of Paul Dirac on quantum electrodynamics in physics. The six-volume collection, Generalized Functions, written by I. M. Gel′fand and co-authors and published in Russian between 1958 and 1966, gives an introduction to generalized functions and presents various applications to analysis, PDE, stochastic processes, and representation theory. The main
Moghaddam, M.; Saatchi, S.
1996-01-01
To understand and predict the functioning of forest biomes, their interaction with the atmosphere, and their growth rates, the knowledge of moisture content of their canopy and the floor soil is essential. The synthetic aperture radar on airborne and spaceborne platforms has proven to be a flexible tool for measuring electromagnetic back- scattering properties of vegetation related to their moisture content.
Neutron scatter studies of chromatin structures related to functions
Energy Technology Data Exchange (ETDEWEB)
Bradbury, E.M.
1992-01-01
Despite of setbacks in the lack of neutrons for the proposed We have made considerable progress in chromatin reconstitution with the VLR histone H1/H5 and in understanding the dynamics of nucleosomes. A ferromagnetic fluid was developed to align biological molecules for structural studies using small-angle-neutron-scattering. We have also identified and characterized an intrinsically bent DNA region flanking the RNA polymerase I binding site of the ribosomal RNA gene in Physarum Polycephalum. Finally projects in progress are in the areas of studying the interatctions of histone H4 amino-terminus peptide 1-23 and acetylated 1-23 peptide with DNA using thermal denaturation; study of GGAAT repeats found in human centromeres using high resolution Nuclear magnetic Resonance and nuclease sentivity assay; and the role of histones and other sperm specific proteins with sperm chromatin.
Neutron scatter studies of chromatin structures related to functions
Energy Technology Data Exchange (ETDEWEB)
Bradbury, E.M.
1992-01-01
We have made considerable progress in chromatin reconstitution with very lysine rich histone H1/H5 and in understanding the dynamics of nucleosomes. A ferromagnetic fluid was developed to align biological molecules for structural studies using small-angle-neutron-scattering. We have also identified and characterized in intrinsically bent DNA region flaking the RNA polymerase I binding site of the ribosomal RNA gene in Physarum Polycephalum. Finally projects in progress are in the areas of studying the interactions of histone H4 amino-terminus peptide 1-23 and acetylated 1-23 peptide with DNA using thermal denaturation; study of GGAAT repeats found in human centromeres using high resolution Nuclear Magnetic Resonance and nuclease sentivity assay; and the role of histones and other sperm specific proteins with sperm chromatin.
Atomic volumes and polarizabilities in density-functional theory.
Kannemann, Felix O; Becke, Axel D
2012-01-21
Becke and Johnson introduced an ad hoc definition of atomic volume [J. Chem. Phys. 124, 014204 (2006)] in order to obtain atom-in-molecule polarizabilities from free-atom polarizabilities in their nonempirical exchange-hole dipole moment model of dispersion interactions. Here we explore the dependence of Becke-Johnson atomic volumes on basis sets and density-functional approximations and provide reference data for all atoms H-Lr. A persuasive theoretical foundation for the Becke-Johnson definition is also provided.
Angular function for the Compton scattering in mildly and ultra relativistic astrophysical plasmas
Sazonov, S Y; Sazonov, Sergei Y.; Sunyaev, Rashid A.
1999-01-01
Compton scattering of low-frequency radiation by an isotropic distribution of(i) mildly and (ii) ultra relativistic electrons is considered. It is shownthat the ensemble-averaged differential cross-section in this case isnoticeably different from the Rayleigh phase function. The scattering by anensemble of ultra-relativistic electrons obeys the law p=1-cos(alpha), wherealpha is the scattering angle; hence photons are preferentially scatteredbackwards. This contrasts the forward scattering behaviour in the Klein-Nishinaregime. Analytical formulae describing first-order Klein-Nishina andfinite-electron-energy corrections to the simple relation above are given forvarious energy distributions of electrons: monoenergetic,relativistic-Maxwellian, and power-law. A similar formula is also given for themildly relativistic (with respect to the photon energy and electrontemperature) corrections to the Rayleigh angular function. One ofmanifestations of the phenomenon under consideration is that hot plasma is morereflecti...
Scattering cluster wave functions on the lattice using the adiabatic projection method
Rokash, Alexander; Elhatisari, Serdar; Lee, Dean; Epelbaum, Evgeny; Krebs, Hermann
2015-01-01
The adiabatic projection method is a general framework for studying scattering and reactions on the lattice. It provides a low-energy effective theory for clusters which becomes exact in the limit of large Euclidean projection time. Previous studies have used the adiabatic projection method to extract scattering phase shifts from finite periodic-box energy levels using L\\"uschers method. In this paper we demonstrate that scattering observables can be computed directly from asymptotic cluster wave functions. For a variety of examples in one and three spatial dimensions, we extract elastic phase shifts from asymptotic cluster standing waves corresponding to spherical wall boundary conditions. We find that this approach of extracting scattering wave functions from the adiabatic Hamiltonian to be less sensitive to small stochastic and systematic errors as compared with using periodic-box energy levels.
On Third-Order Limiter Functions for Finite Volume Methods
Schmidtmann, Birte; Torrilhon, Manuel
2014-01-01
In this article, we propose a finite volume limiter function for a reconstruction on the three-point stencil. Compared to classical limiter functions in the MUSCL framework, which yield $2^{\\text{nd}}$-order accuracy, the new limiter is $3^\\text{rd}$-order accurate for smooth solutions. In an earlier work, such a $3^\\text{rd}$-order limiter function was proposed and showed successful results [2]. However, it came with unspecified parameters. We close this gap by giving information on these parameters.
Finite volume form factors and correlation functions at finite temperature
Pozsgay, Balázs
2009-01-01
In this thesis we investigate finite size effects in 1+1 dimensional integrable QFT. In particular we consider matrix elements of local operators (finite volume form factors) and vacuum expectation values and correlation functions at finite temperature. In the first part of the thesis we give a complete description of the finite volume form factors in terms of the infinite volume form factors (solutions of the bootstrap program) and the S-matrix of the theory. The calculations are correct to all orders in the inverse of the volume, only exponentially decaying (residual) finite size effects are neglected. We also consider matrix elements with disconnected pieces and determine the general rule for evaluating such contributions in a finite volume. The analytic results are tested against numerical data obtained by the truncated conformal space approach in the Lee-Yang model and the Ising model in a magnetic field. In a separate section we also evaluate the leading exponential correction (the $\\mu$-term) associate...
Detection of fast flying nanoparticles by light scattering over a large volume
Pettazzi, F.; Bäumer, S.M.B.; Donck, J.C.J. van der; Deutz, A.F.
2015-01-01
Detection of nanoparticles is of paramount importance for contamination control in ultra-clean systems. Light scattering is a well-known detection method which is applied in many different scientific and technology domains including atmospheric physics, environmental control, and biology. It allows
Correlation functions of scattering matrix elements in microwave cavities with strong absorption
Energy Technology Data Exchange (ETDEWEB)
Schaefer, R [Fachbereich Physik, Philipps-Universitaet Marburg, Renthof 5, D-35032 Marburg (Germany); Gorin, T [Theoretische Quantendynamik, Fakultaet fuer Physik, Universitaet Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg (Germany); Seligman, T H [Centro de Ciencias Fisicas, Universidad Nacional Autonoma de Mexico, Campus Morelos, CP 62251, Cuernavaca, Morelos (Mexico); Stoeckmann, H-J [Fachbereich Physik, Philipps-Universitaet Marburg, Renthof 5, D-35032 Marburg (Germany)
2003-03-28
The scattering matrix was measured for microwave cavities with two antennae. It was analysed in the regime of overlapping resonances. The theoretical description in terms of a statistical scattering matrix and the rescaled Breit-Wigner approximation has been applied to this regime. The experimental results for the auto-correlation function show that the absorption in the cavity walls yields an exponential decay. This behaviour can only be modelled using a large number of weakly coupled channels. In comparison to the auto-correlation functions, the cross-correlation functions of the diagonal S-matrix elements display a more pronounced difference between regular and chaotic systems.
Correlation functions of scattering matrix elements in microwave cavities with strong absorption
Schäfer, R.; Gorin, T.; Seligman, T. H.; Stöckmann, H.-J.
2003-03-01
The scattering matrix was measured for microwave cavities with two antennae. It was analysed in the regime of overlapping resonances. The theoretical description in terms of a statistical scattering matrix and the rescaled Breit-Wigner approximation has been applied to this regime. The experimental results for the auto-correlation function show that the absorption in the cavity walls yields an exponential decay. This behaviour can only be modelled using a large number of weakly coupled channels. In comparison to the auto-correlation functions, the cross-correlation functions of the diagonal S-matrix elements display a more pronounced difference between regular and chaotic systems.
Hadron scattering and resonances in QCD
Energy Technology Data Exchange (ETDEWEB)
Dudek, Jozef J. [Old Dominion Univ., Norfolk, VA (United States)
2016-05-01
I describe how hadron-hadron scattering amplitudes are related to the eigenstates of QCD in a finite cubic volume. The discrete spectrum of such eigenstates can be determined from correlation functions computed using lattice QCD, and the corresponding scattering amplitudes extracted. I review results from the Hadron Spectrum Collaboration who have used these finite volume methods to study pi pi elastic scattering, including the rho resonance, as well as coupled-channel pi K, eta K scattering. Ongoing calculations are advertised and the outlook for finite volume approaches is presented.
Zhan, Hanyu; Voelz, David G.
2016-12-01
The polarimetric bidirectional reflectance distribution function (pBRDF) describes the relationships between incident and scattered Stokes parameters, but the familiar surface-only microfacet pBRDF cannot capture diffuse scattering contributions and depolarization phenomena. We propose a modified pBRDF model with a diffuse scattering component developed from the Kubelka-Munk and Le Hors et al. theories, and apply it in the development of a method to jointly estimate refractive index, slope variance, and diffuse scattering parameters from a series of Stokes parameter measurements of a surface. An application of the model and estimation approach to experimental data published by Priest and Meier shows improved correspondence with measurements of normalized Mueller matrix elements. By converting the Stokes/Mueller calculus formulation of the model to a degree of polarization (DOP) description, the estimation results of the parameters from measured DOP values are found to be consistent with a previous DOP model and results.
Lemes, N. H. T.; Borges, E.; Sousa, R. V.; Braga, J. P.
Important physical and chemical information can be extracted from scattering experiments data. This kind of problem is usually ill-posed in the sense that one of the three conditions, existence, uniqueness, and continuity, is not satisfied. For example, the inversion of intermolecular potential functions from scattering data, such as experimental cross section, is an ill-posed problem which can be modeled as a Fredholm integral equation. In this work, an inversion method based on recursive neural networks is proposed to solve this inverse quantum scattering problem within the Born approximation. As physical example, the repulsive component of the potential function for the interaction Ar-Ar is obtained from differential cross-section data. The sensitivity of the potential energy function to be inverted, in relation to the differential cross-section data, is also analyzed. The present approach is simple, general, and numerically stable.
1969-08-31
can write Eq 12 as -•> -> -^ -’? |~> n(q1)n(q2| <h) pCq ^qV - p(qi)p(q2’ <L> = —ZT^T\\ • > Here the conditional number density n(q2|qi...have p(q\\,-.-»qN) - p(q\\) pCq ^)--- v(%) * ( 18) that is, the joint probability density function is expressible as the product of the individual...r<?,«)+ y J*. . ./T(q^) t (^«-Iq^iq^,. . . .q^ pCq ^,. . . ,q\\j)dq\\. . .dq^ m=l N = f (r»+ ][ /• • .jT(q^) ^E(r,U)| qmt q\\, . . . ,q»N) m=l
Sekihara, Takayasu
2016-01-01
For a general two-body bound state in quantum mechanics, both in the stable and decaying cases, we establish a way to extract its two-body wave function in momentum space from the scattering amplitude of the constituent two particles. For this purpose, we first show that the two-body wave function of the bound state corresponds to the residue of the off-shell scattering amplitude at the bound state pole. Then, we examine our scheme to extract the two-body wave function from the scattering amplitude in several schematic models. As a result, the two-body wave functions from the Lippmann--Schwinger equation coincides with that from the Schr\\"{o}dinger equation for an energy-independent interaction. Of special interest is that the two-body wave function from the scattering amplitude is automatically scaled; the norm of the two-body wave function, to which we refer as the compositeness, is unity for an energy-independent interaction, while the compositeness deviates from unity for an energy-dependent interaction, ...
Hybrid Finite Element and Volume Integral Methods for Scattering Using Parametric Geometry
DEFF Research Database (Denmark)
Volakis, John L.; Sertel, Kubilay; Jørgensen, Erik
2004-01-01
n this paper we address several topics relating to the development and implementation of volume integral and hybrid finite element methods for electromagnetic modeling. Comparisons of volume integral equation formulations with the finite element-boundary integral method are given in terms of accu...... of vanishing divergence within the element but non-zero curl. In addition, a new domain decomposition is introduced for solving array problems involving several million degrees of freedom. Three orders of magnitude CPU reduction is demonstrated for such applications....
On the applications of Hardy class functions in scattering theory
Gadella, M
2007-01-01
This paper is a response to an article (R. de la Madrid, Journal of Physics A: Mathematical and General, 39,9255-9268 (2006)) recently published in Journal of Physics A: Mathematical and Theoretical. The article claims that the theory of resonances and decaying states based on certain rigged Hilbert spaces of Hardy functions is physically untenable. In this paper we show that all of the key conclusions of the cited article are the result of either the errors in mathematical reasoning or an inadequate understanding of the literature on the subject.
Outgoing Cuntz Scattering System for a Coisometric Lifting and Transfer Function
Indian Academy of Sciences (India)
Kalpesh J Haria
2013-08-01
We study a coisometry that intertwines Popescu’s presentations of minimal isometric dilations of a given operator tuple and of a coisometric lifting of the tuple. Using this we develop an outgoing Cuntz scattering system which gives rise to an input–output formalism. A transfer function is introduced for the system. We also compare the transfer function and the characteristic function for the associated lifting.
Celik, I H; Demirel, G; Sukhachev, D; Erdeve, O; Dilmen, U
2013-02-01
Neonatal sepsis remains an important clinical syndrome despite advances in neonatology. Current hematology analyzers can determine cell volume (V), conductivity for internal composition of cell (C) and light scatter for cytoplasmic granularity and nuclear structure (S), and standard deviations which are effective in the diagnosis of sepsis. Statistical models can be used to strengthen the diagnosis. Effective modeling of molecular activity (EMMA) uses combinatorial algorithm of the selection parameters for regression equation based on modified stepwise procedure. It allows obtaining different regression models with different combinations of parameters. We investigated these parameters in screening of neonatal sepsis. We used LH780 hematological analyzer (Beckman Coulter, Fullerton, CA, USA). We combined these parameters with interleukin-6 (IL-6) and C-reactive protein (CRP) and developed models by EMMA. A total of 304 newborns, 76 proven sepsis, 130 clinical sepsis and 98 controls, were enrolled in the study. Mean neutrophil volume (MNV) and volume distribution width (VDW) were higher in both proven and clinical sepsis groups. We developed three models using MNV, VDW, IL-6, and CRP. These models gave more sensitivity and specificity than the usage of each marker alone. We suggest to use the combination of MNV and VDW with markers such as CRP and IL-6, and use diagnostic models created by EMMA. © 2012 Blackwell Publishing Ltd.
PET functional volume delineation: a robustness and repeatability study
Energy Technology Data Exchange (ETDEWEB)
Hatt, Mathieu [CHU Morvan, INSERM, U650, LaTIM, Brest (France); CHU MORVAN, LaTIM, INSERM U650, Brest (France); Cheze-le Rest, Catherine [CHU Morvan, INSERM, U650, LaTIM, Brest (France); CHU, Academic Department of Nuclear Medicine, Brest (France); Albarghach, Nidal; Pradier, Olivier [CHU Morvan, INSERM, U650, LaTIM, Brest (France); CHU, Institute of Oncology, Brest (France); Visvikis, Dimitris [CHU Morvan, INSERM, U650, LaTIM, Brest (France)
2011-04-15
Current state-of-the-art algorithms for functional uptake volume segmentation in PET imaging consist of threshold-based approaches, whose parameters often require specific optimization for a given scanner and associated reconstruction algorithms. Different advanced image segmentation approaches previously proposed and extensively validated, such as among others fuzzy C-means (FCM) clustering, or fuzzy locally adaptive bayesian (FLAB) algorithm have the potential to improve the robustness of functional uptake volume measurements. The objective of this study was to investigate robustness and repeatability with respect to various scanner models, reconstruction algorithms and acquisition conditions. Robustness was evaluated using a series of IEC phantom acquisitions carried out on different PET/CT scanners (Philips Gemini and Gemini Time-of-Flight, Siemens Biograph and GE Discovery LS) with their associated reconstruction algorithms (RAMLA, TF MLEM, OSEM). A range of acquisition parameters (contrast, duration) and reconstruction parameters (voxel size) were considered for each scanner model, and the repeatability of each method was evaluated on simulated and clinical tumours and compared to manual delineation. For all the scanner models, acquisition parameters and reconstruction algorithms considered, the FLAB algorithm demonstrated higher robustness in delineation of the spheres with low mean errors (10%) and variability (5%), with respect to threshold-based methodologies and FCM. The repeatability provided by all segmentation algorithms considered was very high with a negligible variability of <5% in comparison to that associated with manual delineation (5-35%). The use of advanced image segmentation algorithms may not only allow high accuracy as previously demonstrated, but also provide a robust and repeatable tool to aid physicians as an initial guess in determining functional volumes in PET. (orig.)
Excitation function of elastic $pp$ scattering from a unitarily extended Bialas-Bzdak model
Nemes, F.; Csanád, M.
2015-01-01
The Bialas-Bzdak model of elastic proton-proton scattering assumes a purely imaginary forward scattering amplitude, which consequently vanishes at the diffractive minima. We extended the model to arbitrarily large real parts in a way that constraints from unitarity are satisfied. The resulting model is able to describe elastic $pp$ scattering not only at the lower ISR energies but also at $\\sqrt{s}=$7~TeV in a statistically acceptable manner, both in the diffractive cone and in the region of the first diffractive minimum. The total cross-section as well as the differential cross-section of elastic proton-proton scattering is predicted for the future LHC energies of $\\sqrt{s}=$13, 14, 15~TeV and also to 28~TeV. A non-trivial, significantly non-exponential feature of the differential cross-section of elastic proton-proton scattering is analyzed and the excitation function of the non-exponential behavior is predicted. The excitation function of the shadow profiles is discussed and related to saturation at small ...
Excitation function of elastic $pp$ scattering from a unitarily extended Bialas-Bzdak model
Nemes, F; Csanád, M
2014-01-01
The Bialas-Bzdak model of elastic proton-proton scattering assumes a purely imaginary forward scattering amplitude, which consequently vanishes at the diffractive minima. We extended the model to arbitrarily large real parts in a way that constraints from unitarity are satisfied. The resulting model is able to describe elastic $pp$ scattering not only at the lower ISR energies but also at $\\sqrt{s}=$7 TeV in a statistically acceptable manner, both in the diffractive cone and in the region of the first diffractive minimum. The total cross-section as well as the differential cross-section of elastic proton-proton scattering is predicted for the future LHC energies of $\\sqrt{s}=$8, 13, 14, 15 TeV and also to 28 TeV. A non-trivial, significantly non-exponential feature of the differential cross-section of elastic proton-proton scattering is analyzed and the excitation function of the non-exponential behavior is predicted. The excitation function of the shadow profiles is discussed and related to saturation at sma...
The phase-functions method and full cross-section of nucleon-nucleon scattering
Zhaba, V I
2016-01-01
For calculation of the single-channel nucleon-nucleon scattering a phase-functions method has been considered. Using a phase-functions method the following phase shifts of a nucleon-nucleon scattering are calculated numerically: nn (1S0-, 3P0-, 3P1-, 1D2-, 3F3- state), pp (1S0-, 3P0-, 3P1-, 1D2- state) and np (1S0-, 1P1-, 3P0-, 3P1-, 1D2-, 3D2- state). The calculations has been performed using realistic nucleon-nucleon potentials Nijmegen groups (NijmI, NijmII, Reid93) and potential Argonne v18. Obtained phase shifts are in good agreement with the results obtained in the framework of other methods. Using the obtained phase shifts we have calculated the full cross-section. Our results are in good agreement with those obtained by using known phases published in literature. The odds between calculations depending on a computational method of phases of scattering makes: 0,2-6,3% for pp- and 0,1-5,3% for np- scatterings (NijmI, NijmII), 0,1-4,1% for pp- and 0,1-0,4% for np- scatterings (Reid93), no more than 4,5% ...
Shi, F.; Lowe, M. J. S.; Craster, R. V.
2017-02-01
We propose an ultrasonic methodology to reconstruct the height correlation function of remotely inaccessible random rough surfaces in solids. The inverse method is based on the Kirchhoff approximation(KA), and it requires measuring the angular distribution of diffuse scattering intensities by sending in a narrow band incident pulse. Near field scattering effects are also included by considering the Fresnel assumption. The proposed approach is successfully verified by simulating the scattering from multiple realizations of rough surfaces whose correlation function is known, calculating the mean scattering intensities from these received signals, and then deploying the inverse method on these to reconstruct the original correlation function. Very good agreement between the reconstructed correlation function and the original is found, for a wide range of roughness parameters. In addition, the effect of reducing the number of realizations to approximate the mean intensity are investigated, providing confidence bounds for the experiment. An experiment on a corrugated rough surface is performed with a limited number of scans using a phased array, which further validates the proposed inversion algorithm.
On the calculation of x-ray scattering signals from pairwise radial distribution functions
DEFF Research Database (Denmark)
Dohn, Asmus Ougaard; Biasin, Elisa; Haldrup, Kristoffer;
2015-01-01
We derive a formulation for evaluating (time-resolved) x-ray scattering signals of solvated chemical systems, based on pairwise radial distribution functions, with the aim of this formulation to accompany molecular dynamics simulations. The derivation is described in detail to eliminate any possi...
A discrete-time channel simulator driven by measured scattering functions
Walree, P.A. van; Jenserud, T.; Smedsrud, M.
2008-01-01
In-situ measurements of the scattering function are used to drive a channel simulator developed in the context of underwater acoustic telemetry. Two operation modes of the simulator are evaluated. A replay mode is accomplished by interpolation of measured impulse responses. A second, stochastic mode
Velocity-Autocorrelation Function in Liquids, Deduced from Neutron Incoherent Scattering Results
DEFF Research Database (Denmark)
Carneiro, Kim
1976-01-01
The Fourier transform p(ω) of the velocity-autocorrelation function is derived from neutron incoherent scattering results, obtained from the two liquids Ar and H2. The quality and significance of the results are discussed with special emphasis on the long-time t-3/2 tail, found in computer...
Functional materials analysis using in situ and in operando X-ray and neutron scattering.
Peterson, Vanessa K; Papadakis, Christine M
2015-03-01
In situ and in operando studies are commonplace and necessary in functional materials research. This review highlights recent developments in the analysis of functional materials using state-of-the-art in situ and in operando X-ray and neutron scattering and analysis. Examples are given covering a number of important materials areas, alongside a description of the types of information that can be obtained and the experimental setups used to acquire them.
Functional materials analysis using in situ and in operando X-ray and neutron scattering
Directory of Open Access Journals (Sweden)
Vanessa K. Peterson
2015-03-01
Full Text Available In situ and in operando studies are commonplace and necessary in functional materials research. This review highlights recent developments in the analysis of functional materials using state-of-the-art in situ and in operando X-ray and neutron scattering and analysis. Examples are given covering a number of important materials areas, alongside a description of the types of information that can be obtained and the experimental setups used to acquire them.
Gokcebay, D G; Azik, F M; Isik, P; Bozkaya, I O; Kara, A; Tavil, E B; Yarali, N; Tunc, B
2011-12-01
Asparaginase, an effective drug in the treatment of childhood acute lymphoblastic leukemia (ALL), has become an important component of most childhood ALL regimens during the remission induction or intensification phases of treatment. The incidence range of asparaginase-associated lipid abnormalities that are seen in children is 67-72%. Lipemia causes erroneous results, which uses photometric methods to analyze blood samples. We describe a case of l-asparaginase-associated severe hyperlipidemia with complete blood count abnormalities. Complete blood count analysis was performed with Beckman COULTER(®) GEN·S™ system, which uses the Coulter Volume, Conductivity, Scatter technology to probe hydrodynamically focused cells. Although an expected significant inaccuracy in hemoglobin determination occurred starting from a lipid value of 3450 mg/dl, we observed that triglyceride level was 1466 mg/dl. Complete blood count analysis revealed that exceptionally high hemoglobin, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration levels vs. discordant with red blood cell count, mean corpuscular volume, and hematocrit levels. Total leukocyte count altered spontaneously in a wide range, and was checked with blood smear. Platelet count was in expected range (Table 1). Thus, we thought it was a laboratory error, and the patient's follow-up especially for red cell parameters was made by red blood cell and hematocrit values.
Energy Technology Data Exchange (ETDEWEB)
Franz Gross, Alfred Stadler
2010-09-01
We present the effective range expansions for the 1S0 and 3S1 scattering phase shifts, and the relativistic deuteron wave functions that accompany our recent high precision fits (with \\chi^2/N{data} \\simeq 1) to the 2007 world np data below 350 MeV. The wave functions are expanded in a series of analytical functions (with the correct asymptotic behavior at both large and small arguments) that can be Fourier-transformed from momentum to coordinate space and are convenient to use in any application. A fortran subroutine to compute these wave functions can be obtained from the authors.
Thueler, Philippe; Charvet, Igor; Bevilacqua, Frederic; St Ghislain, M; Ory, G; Marquet, Pierre; Meda, Paolo; Vermeulen, Ben; Depeursinge, Christian
2003-07-01
A fast spectroscopic system for superficial and local determination of the absorption and scattering properties of tissue (480 to 950 nm) is described. The probe can be used in the working channel of an endoscope. The scattering properties include the reduced scattering coefficient and a parameter of the phase function called gamma, which depends on its first two moments. The inverse problem algorithm is based on the fit of absolute reflectance measurements to cubic B-spline functions derived from the interpolation of a set of Monte Carlo simulations. The algorithm's robustness was tested with simulations altered with various amounts of noise. The method was also assessed on tissue phantoms of known optical properties. Finally, clinical measurements performed endoscopically in vivo in the stomach of human subjects are presented. The absorption and scattering properties were found to be significantly different in the antrum and in the fundus and are correlated with histopathologic observations. The method and the instrument show promise for noninvasive tissue diagnostics of various epithelia.
Kocifaj, Miroslav
2011-06-10
The approximate bulk-scattering phase function of a polydisperse system of dust particles is derived in an analytical form. In the theoretical solution, the particle size distribution is modeled by a modified gamma function that can satisfy various media differing in modal radii. Unlike the frequently applied power law, the modified gamma distribution shows no singularity when the particle radius approaches zero. The approximate scattering phase function is related to the parameters of the size distribution function. This is an important advantage compared to the empirical Henyey-Greenstein (HG) approximation, which is a simple function of the average cosine. However, any optimized value of average cosine of the HG function cannot provide the information on particle microphysical characteristics, such as the size distribution function. In this paper, the mapping between average cosine and the parameters of size distribution function is given by a semianalytical expression that is applicable in rapid numerical simulations on various dust populations. In particular, the modal radius and half-width can be quickly estimated using the presented formulas.
Institute of Scientific and Technical Information of China (English)
Wu Fuxian; Wen Weidong
2016-01-01
Classic maximum entropy quantile function method (CMEQFM) based on the probabil-ity weighted moments (PWMs) can accurately estimate the quantile function of random variable on small samples, but inaccurately on the very small samples. To overcome this weakness, least square maximum entropy quantile function method (LSMEQFM) and that with constraint condition (LSMEQFMCC) are proposed. To improve the confidence level of quantile function estimation, scatter factor method is combined with maximum entropy method to estimate the confidence inter-val of quantile function. From the comparisons of these methods about two common probability distributions and one engineering application, it is showed that CMEQFM can estimate the quan-tile function accurately on the small samples but inaccurately on the very small samples (10 sam-ples); LSMEQFM and LSMEQFMCC can be successfully applied to the very small samples;with consideration of the constraint condition on quantile function, LSMEQFMCC is more stable and computationally accurate than LSMEQFM; scatter factor confidence interval estimation method based on LSMEQFM or LSMEQFMCC has good estimation accuracy on the confidence interval of quantile function, and that based on LSMEQFMCC is the most stable and accurate method on the very small samples (10 samples).
On the calculation of x-ray scattering signals from pairwise radial distribution functions
DEFF Research Database (Denmark)
Dohn, Asmus Ougaard; Biasin, Elisa; Haldrup, Kristoffer;
2015-01-01
We derive a formulation for evaluating (time-resolved) x-ray scattering signals of solvated chemical systems, based on pairwise radial distribution functions, with the aim of this formulation to accompany molecular dynamics simulations. The derivation is described in detail to eliminate any possi...... possible ambiguities, and the result includes a modification to the atom-type formulation which to our knowledge is previously unaccounted for. The formulation is numerically implemented and validated.......We derive a formulation for evaluating (time-resolved) x-ray scattering signals of solvated chemical systems, based on pairwise radial distribution functions, with the aim of this formulation to accompany molecular dynamics simulations. The derivation is described in detail to eliminate any...
Sato, T.; Satoh, T.; Kasaba, Y.
2010-12-01
The three distinct cloud layers were predicted by an equilibrium cloud condensation model (ECCM) of Jupiter. An ammonia ice cloud (NH3), an ammonia hydrosulfide cloud (NH4SH), and a water ice (H2O) cloud would be based at altitudes corresponding to pressures of about 0.7, 2.2 and 6 bars, respectively. However, there are significant gaps in our knowledge of the vertical cloud structure, despite the continuing effort by numerous ground-based, space-based, and in-situ observations and theory. Methane (CH4) is considered that its altitude distribution is globally uniform because it does not condense in Jovian atmosphere. Therefore, it is possible to derive the vertical cloud structure and the optical properties of clouds (i.e., optical thickness and single scattering albedo) by observing reflected sunlight in CH4 bands (727, 890 nm) and continuum in visible to near-infrared spectral ranges. Since we need to consider multiple scattering by clouds, it is essential to know scattering properties (e.g., scattering phase function) of clouds for determination of vertical cloud structure. However, we cannot derive those from ground-based and Earth-orbit observations because of the limitation of solar phase angle as viewed from the Earth. Then, most previous studies have used the scattering phase function deduced from the Pioneer 10/IPP data (blue: 440 nm, red: 640nm) [Tomasko et al., 1978]. There are two shortcomings in the Pioneer scattering phase function. One is that we have to use this scattering phase function at red as a substitute for analyses of imaging photometry using CH4 bands (center: 727 and 890 nm), although clouds should have wavelength dependency. The other is that the red pass band of IPP was so broad (595-720 nm) that this scattering phase function in red just show wavelength-averaged scattering properties of clouds. To provide a new reference scattering phase function with wavelength dependency, we have analyzed the Cassini/ISS data in BL1 (451 nm), CB1 (619
Green's function multiple-scattering theory with a truncated basis set: An augmented-KKR formalism
Alam, Aftab; Khan, Suffian N.; Smirnov, A. V.; Nicholson, D. M.; Johnson, Duane D.
2014-11-01
The Korringa-Kohn-Rostoker (KKR) Green's function, multiple-scattering theory is an efficient site-centered, electronic-structure technique for addressing an assembly of N scatterers. Wave functions are expanded in a spherical-wave basis on each scattering center and indexed up to a maximum orbital and azimuthal number Lmax=(l,mmax), while scattering matrices, which determine spectral properties, are truncated at Lt r=(l,mt r) where phase shifts δl >ltr are negligible. Historically, Lmax is set equal to Lt r, which is correct for large enough Lmax but not computationally expedient; a better procedure retains higher-order (free-electron and single-site) contributions for Lmax>Lt r with δl >ltr set to zero [X.-G. Zhang and W. H. Butler, Phys. Rev. B 46, 7433 (1992), 10.1103/PhysRevB.46.7433]. We present a numerically efficient and accurate augmented-KKR Green's function formalism that solves the KKR equations by exact matrix inversion [R3 process with rank N (ltr+1 ) 2 ] and includes higher-L contributions via linear algebra [R2 process with rank N (lmax+1) 2 ]. The augmented-KKR approach yields properly normalized wave functions, numerically cheaper basis-set convergence, and a total charge density and electron count that agrees with Lloyd's formula. We apply our formalism to fcc Cu, bcc Fe, and L 1 0 CoPt and present the numerical results for accuracy and for the convergence of the total energies, Fermi energies, and magnetic moments versus Lmax for a given Lt r.
Baryon scattering at high energies: wave function, impact factor, and gluon radiation
Bartels, J
2007-01-01
The scattering of a baryon consisting of three massive quarks is investigated in the high energy limit of perturbative QCD. A model of a relativistic proton-like wave function, dependent on valence quark longitudinal and transverse momenta and on quark helicities, is proposed, and we derive the baryon impact factors for two, three and four t-channel gluons. We find that the baryonic impact factor can be written as a sum of three pieces: in the first one a subsystem consisting of two of the three quarks behaves very much like the quark-antiquark pair in gamma* scattering, whereas the third quark acts as a spectator. The second term belongs to the odderon, whereas in the third (C-even) piece all three quarks participate in the scattering. This term is new and has no analogue in gamma* scattering. We also study the small x evolution of gluon radiation for each of these three terms. The first term follows the same pattern of gluon radiation as the gamma*-initiated quark-antiquark dipole, and, in particular, it co...
Roohani Ghehsareh, Hadi; Kamal Etesami, Seyed; Hajisadeghi Esfahani, Maryam
2016-08-01
In the current work, the electromagnetic (EM) scattering from infinite perfectly conducting cylinders with arbitrary cross sections in both transverse magnetic (TM) and transverse electric (TE) modes is numerically investigated. The problems of TE and TM EM scattering can be mathematically modelled via the magnetic field integral equation (MFIE) and the electric field integral equation (EFIE), respectively. An efficient technique is performed to approximate the solution of these surface integral equations. In the proposed numerical method, compactly supported radial basis functions (RBFs) are employed as the basis functions. The radial and compactly supported properties of these basis functions substantially reduce the computational cost and improve the efficiency of the method. To show the accuracy of the proposed technique, it has been applied to solve three interesting test problems. Moreover, the method is well used to compute the electric current density and also the radar cross section (RCS) for some practical scatterers with different cross section geometries. The reported numerical results through the tables and figures demonstrate the efficiency and accuracy of the proposed technique.
Energy Technology Data Exchange (ETDEWEB)
Urbina, A; Miguel, C [Departamento Electronica, Universidad Politecnica de Cartagena, Plaza Hospital 1, 30202 Cartagena (Spain); Delgado, J L; Langa, F [Facultad de Ciencias del Medio Ambiente, Universidad de Castilla-La Mancha, 45071, Toledo (Spain); DIaz-Paniagua, C [Centro Espanol de MetrologIa, 28760 Madrid (Spain); Jimenez, M [Institut Laue-Langevin, 39042 Grenoble Cedex (France); Batallan, F [Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid (Spain)], E-mail: antonio.urbina@upct.es
2008-03-12
We have studied, by incoherent neutron scattering experiments, the dynamics of a colloidal suspension of functionalized single wall carbon nanotubes (SWNTs). The nanotubes have been functionalized with pentyl ester groups attached at the ends and suspended in deuterated toluene with a concentration of 2.6 mg SWNT/1 ml of deuterated toluene. The experimental techniques were incoherent elastic neutron scattering (IENS) and incoherent quasielastic neutron scattering (IQNS). In the temperature range between 4 K and 300 K, three phases were observed by IENS measurements: a solid phase for T
S.C. Kanick (Stephen); V. Krishnaswamy (V.); U.A. Gamm; H.J.C.M. Sterenborg (Dick); D.J. Robinson (Dominic); A. Amelink (Arjen); B.W. Pogue (B.)
2012-01-01
textabstractReflectance spectra measured in Intralipid (IL) close to the source are sensitive to wavelength-dependent changes in reduced scattering coefficient (μs ′) and scattering phase function (PF). Experiments and simulations were performed using device designs with either single or separate
Incoherent scatter spectra from plasma of a 13-moment approximation distribution function
Institute of Scientific and Technical Information of China (English)
2008-01-01
The function and physical mechanism of heat flow and the viscous stress in the velocity distribution function expanded by Maxwellian distribution are presented. With the introduction of effective temperature Tf, incoherent scatter spectra from plasma for electromagnetic wave in arbitrary line of sight are given. The effect of asymmetry and anisotropy provided by heat flow and the viscous stress on power spectra is discussed. Radar spectra are calculated for different cases of electric field, direction, collision frequency and temperature. The effect of heat flow and the viscous stress on inversion results is analyzed. With a large electric field, the character of non-Maxwellian must be considered.
Energy Technology Data Exchange (ETDEWEB)
Novaes, Marcel [Instituto de Física, Universidade Federal de Uberlândia, Ave. João Naves de Ávila, 2121, Uberlândia, MG 38408-100 (Brazil)
2015-06-15
We consider the statistics of time delay in a chaotic cavity having M open channels, in the absence of time-reversal invariance. In the random matrix theory approach, we compute the average value of polynomial functions of the time delay matrix Q = − iħS{sup †}dS/dE, where S is the scattering matrix. Our results do not assume M to be large. In a companion paper, we develop a semiclassical approximation to S-matrix correlation functions, from which the statistics of Q can also be derived. Together, these papers contribute to establishing the conjectured equivalence between the random matrix and the semiclassical approaches.
Hong, Liang; Jain, Nitin; Cheng, Xiaolin; Bernal, Ana; Tyagi, Madhusudan; Smith, Jeremy C.
2016-01-01
Protein function often depends on global, collective internal motions. However, the simultaneous quantitative experimental determination of the forms, amplitudes, and time scales of these motions has remained elusive. We demonstrate that a complete description of these large-scale dynamic modes can be obtained using coherent neutron-scattering experiments on perdeuterated samples. With this approach, a microscopic relationship between the structure, dynamics, and function in a protein, cytochrome P450cam, is established. The approach developed here should be of general applicability to protein systems. PMID:27757419
Novaes, Marcel
2015-06-01
We consider the statistics of time delay in a chaotic cavity having M open channels, in the absence of time-reversal invariance. In the random matrix theory approach, we compute the average value of polynomial functions of the time delay matrix Q = - iħS†dS/dE, where S is the scattering matrix. Our results do not assume M to be large. In a companion paper, we develop a semiclassical approximation to S-matrix correlation functions, from which the statistics of Q can also be derived. Together, these papers contribute to establishing the conjectured equivalence between the random matrix and the semiclassical approaches.
Heavy-ion fusion and scattering with Skyrme energy density functional
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
In our recent studies,an empirical barrier distribution was proposed for a unified description of the fusion cross sections of light and medium-heavy fusion systems,the capture cross sections of the reactions leading to superheavy nuclei,and the large-angle quasi-elastic scattering cross sections based on the Skyrme energy-density functional approach.In this paper,we first give a brief review of these results.Then,by examining the barrier distributions in detail,we find that the fusion cross sections depend more strongly on the shape of the left side of the barrier distribution while the quasi-elastic scattering cross sections depend more strongly on the right side.Furthermore,by combining these studies and the HIVAP calculations for the survival probability,the formation probability of the compound nucleus is deduced from the measured evaporation residue cross sections for "cold" and "hot" fusion reactions.
The total scattering atomic pair distribution function: New methodology for nanostructure analysis
Masadeh, Ahmad
The conventional xray diffration (XRD) methods probe for the presence of long-range order (periodic structure) which are reflected in the Bragg peaks. Local structural deviations or disorder mainly affect the diffuse scattering intensity. In order to obtain structural information about both long-range order and local structure disorder, a technique that takes in account both Bragg and diffuse scattering need to be employed, such as the atomic pair distribution function (PDF) technique. This work introduces a PDF based methodology to quantitatively investigate nanostructure materials in general. The introduced methodology can be applied to extract quantitatively structural information about structure, crystallinity level, core/shell size, nanoparticle size, and inhomogeneous internal strain in the measured nanoparticles. This method is generally applicable to the characterization of the nano-scale solid, many of which may exhibit complex disorder and strain
Greenwald, R. A.; Frissell, N. A.; de Larquier, S.
2016-12-01
In this paper, we evaluate the performance of three methods used by HF radars in the SuperDARN network for determining the ground ranges to ionospheric scattering volumes. Each method uses somewhat different approaches, but the same equivalent-path analysis. We also show that Snell's Law can be added to this analysis to determine the refractive index of each scattering volume and thereby correct Doppler velocity measurements for ionospheric refraction. Two of these methods make their predictions using the group range to the scattering volume and a virtual height model, while the third method uses the group range and the elevation angle each backscattered return. The effectiveness of each of these methods is evaluated using ray tracing analyses through the International Reference Ionosphere. Ray tracings analysis provides determinations of the initial elevation angle, group range, group range, and refractive index of each ionospheric volume that backscatters signals to the radar. The initial or final elevation angle and the group range are used as inputs to the geolocation methods and the ground range and refractive index serve as reference data against which the predictions of the geolocation methods can be evaluated. We find that the methods using virtual height models actually change the initial elevation angle determined from ray tracing to a different elevation angle that is consistent with the virtual height model. Due to this change, predictions of the ground range and refractive index of scattering volumes located with virtual-height models are rarely consistent with the predictions obtained from ray tracing. In contrast, the geolocation method that uses the group range and initial or final elevation angle yields predictions that are in good agreement with ray tracing. Modifications to the equivalent-path analysis are required to obtain consistent predictions of the ground range and refractive index of backscatter from the topside F-layer.
Deep Inelastic Scattering from A=3 Nuclei and the Neutron Structure Function
Energy Technology Data Exchange (ETDEWEB)
I. Afnan; F. Bissey; J. Gomez; A. Katramatou; S. Liuti; W. Melnitchouk; G. Petratos; A.W. Thomas
2003-03-01
We present a comprehensive analysis of deep inelastic scattering from {sup 3}He and {sup 3}H, focusing in particular on the extraction of the free neutron structure function, F{sup n}{sub 2}. Nuclear corrections are shown to cancel to within 1-2% for the isospin-weighted ratio of {sup 3}He to {sup 3}H structure functions, which leads to more than an order of magnitude improvement in the current uncertainty on the neutron to proton ratio F{sup 2n}{sub 2}/F{sup p}{sub 2} at large x. Theoretical uncertainties originating tom the nuclear wave function, including possible non-nucleonic components, are evaluated. Measurement of the {sup 3}He and {sup 3}H structure functions will, in addition, determine the magnitude of the EMC effect in all A [lte] 3 nuclei.
Hinterberger, F; Altmeier, M; Bauer, F; Bisplinghoff, J; Büsser, K; Busch, M; Colberg, T; Diehl, O; Dohrmann, F; Engelhardt, H P; Eversheim, P D; Felden, O; Gebel, R; Glende, M; Greiff, J; Gross-Hardt, R; Hinterberger, F; Jahn, R; Jonas, E; Krause, H; Langkau, R; Lindemann, T; Lindlein, J; Maier, R; Maschuw, R; Mayer-Kuckuk, T; Meinerzhagen, A; Naehle, O; Prasuhn, D; Rohdjess, H; Rosendaal, D; Von Rossen, P; Schirm, N; Schulz-Rojahn, M; Schwarz, V; Scobel, W; Trelle, H J; Weise, E; Wellinghausen, A; Woller, K; Ziegler, R
2000-01-01
The EDDA experiment at the cooler synchrotron COSY measures proton-proton elastic scattering excitation functions in the momentum range 0.8 - 3.4 GeV/c. In phase 1 of the experiment, spin-averaged differential cross sections were measured continuously during acceleration with an internal polypropylene (CH sub 2) fiber target, taking particular care to monitor luminosity as a function of beam momentum. In phase 2, excitation functions of the analyzing power A sub N and the polarization correlation parameters A sub N sub N , A sub S sub S and A sub S sub L are measured using a polarized proton beam and a polarized atomic hydrogen beam target. The paper presents recent d sigma/d OMEGA and A sub N data. The results provide excitation functions and angular distributions of high precision and internal consistency. No evidence for narrow structures was found. The data are compared to recent phase shift solutions.
Deep Inelastic Scattering from A=3 Nuclei and the Neutron Structure Function
Energy Technology Data Exchange (ETDEWEB)
I. Afnan; F. Bissey; J. Gomez; A. Katramatou; S. Liuti; W. Melnitchouk; G. Petratos; A.W. Thomas
2003-03-01
We present a comprehensive analysis of deep inelastic scattering from {sup 3}He and {sup 3}H, focusing in particular on the extraction of the free neutron structure function, F{sup n}{sub 2}. Nuclear corrections are shown to cancel to within 1-2% for the isospin-weighted ratio of {sup 3}He to {sup 3}H structure functions, which leads to more than an order of magnitude improvement in the current uncertainty on the neutron to proton ratio F{sup 2n}{sub 2}/F{sup p}{sub 2} at large x. Theoretical uncertainties originating tom the nuclear wave function, including possible non-nucleonic components, are evaluated. Measurement of the {sup 3}He and {sup 3}H structure functions will, in addition, determine the magnitude of the EMC effect in all A [lte] 3 nuclei.
Deep inelastic scattering from A=3 nuclei and the neutron structure function
Afnan, I. R.; Bissey, F.; Gomez, J.; Katramatou, A. T.; Liuti, S.; Melnitchouk, W.; Petratos, G. G.; Thomas, A. W.
2003-09-01
We present a comprehensive analysis of deep inelastic scattering from 3He and 3H, focusing in particular on the extraction of the free neutron structure function Fn2. Nuclear corrections are shown to cancel to within 1 2% for the isospin-weighted ratio of 3He to 3H structure functions, which leads to more than an order of magnitude improvement in the current uncertainty in the neutron to proton ratio Fn2/Fp2 at large x. Theoretical uncertainties originating from the nuclear wave function, including possible non-nucleonic components, are evaluated. Measurements of the 3He and 3H structure functions will, in addition, determine the magnitude of the EMC effect in all A⩽3 nuclei.
Time reversal odd fragmentation functions in semi-inclusive deep inelastic lepton-hadron scattering
Energy Technology Data Exchange (ETDEWEB)
Mulders, P.J. [National Inst. for Nuclear Physics and High Energy Physics, Amsterdam (Netherlands); Levelt, J. [Univ. of Erlangen-Nuernberg (Germany)
1994-04-01
In semi-inclusive scattering of polarized leptons from unpolarized hadrons, one can measure a time reversal odd structure function. It shows up as a sin({phi}) asymmetry of the produced hadrons. This asymmetry can be expressed as the product of a twist-three {open_quotes}hadron {r_arrow} quark{close_quotes} profile function and a time reversal odd twist-two {open_quotes}quark {r_arrow} hadron{close_quotes} fragmentation function. This fragmentation function can only be measured for nonzero transverse momenta of the produced hadron. Its appearance is a consequence of final state interactions between the produced hadron and the rest of the final state.
Single-site Green function of the Dirac equation for full-potential electron scattering
Energy Technology Data Exchange (ETDEWEB)
Kordt, Pascal
2012-05-30
I present an elaborated analytical examination of the Green function of an electron scattered at a single-site potential, for both the Schroedinger and the Dirac equation, followed by an efficient numerical solution, in both cases for potentials of arbitrary shape without an atomic sphere approximation. A numerically stable way to calculate the corresponding regular and irregular wave functions and the Green function is via the angular Lippmann-Schwinger integral equations. These are solved based on an expansion in Chebyshev polynomials and their recursion relations, allowing to rewrite the Lippmann-Schwinger equations into a system of algebraic linear equations. Gonzales et al. developed this method for the Schroedinger equation, where it gives a much higher accuracy compared to previous perturbation methods, with only modest increase in computational effort. In order to apply it to the Dirac equation, I developed relativistic Lippmann-Schwinger equations, based on a decomposition of the potential matrix into spin spherical harmonics, exploiting certain properties of this matrix. The resulting method was embedded into a Korringa-Kohn-Rostoker code for density functional calculations. As an example, the method is applied by calculating phase shifts and the Mott scattering of a tungsten impurity. (orig.)
Taratin, AM; Chesnokov, Yu A; Denisov, A S; Dalpiaz, P; Bagli, E; Taratin, A M; Lapina, L P; Vavilov, S A; Fiorini, M; Vallazza, E; Afonin, A G; Guidi, V; Baricordi, S; Prest, M; Kovalenko, A D; Skorobogatov, V V; Scandale, W; Golovatyukh, V M; Suvorov, V M; Maisheev, V A; Vincenzi, D; Ivanov, Yu M; Hasan, S; Bolognini, D; Yazynin, I A; Della Mea, Gianantonio; Mazzolari, A; Gavrikov, Yu A; Vomiero, A; Milan, R
2010-01-01
Different kinds of deflection in a silicon crystal bent along the (111) axis was observed for 150 GeV/c negative particles. mainly pi(-) mesons, at one of the secondary beams of the CERN SPS. The whole beam was deflected to one side in quasi-bound states of doughnut scattering (DSB) by atomic strings with the efficiency (95.4 +/- 0.2)\\% and with the peak position close to the bend crystal angle, alpha = 185 mu rad. It was observed volume capture of pi(-) mesons into the DSB states with a probability higher than 7\\%. A beam deflection opposite to the crystal bend was observed for some orientations of the crystal axis due to doughnut scattering and subsequent multiple volume reflections of pi(-) mesons by different bent planes crossing the axis. (C) 2010 Elsevier B.V. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Ward, Gregory; Mistrick, Ph.D., Richard; Lee, Eleanor; McNeil, Andrew; Jonsson, Ph.D., Jacob
2011-01-21
We describe two methods which rely on bidirectional scattering distribution functions (BSDFs) to model the daylighting performance of complex fenestration systems (CFS), enabling greater flexibility and accuracy in evaluating arbitrary assemblies of glazing, shading, and other optically-complex coplanar window systems. Two tools within Radiance enable a) efficient annual performance evaluations of CFS, and b) accurate renderings of CFS despite the loss of spatial resolution associated with low-resolution BSDF datasets for inhomogeneous systems. Validation, accuracy, and limitations of the methods are discussed.
Energy Technology Data Exchange (ETDEWEB)
Andrei Afanasev; Igor Akushevich; Nikolai Merenkov
2004-03-01
The electron structure function method is applied to calculate model-independent radiative corrections to an asymmetry of electron-proton scattering. The representations for both spin-independent and spin-dependent parts of the cross-section are derived. Master formulae take into account the leading corrections in all orders and the main contribution of the second order next-to-leading ones and have accuracy at the level of one per mille. Numerical calculations illustrate our analytical results for both elastic and deep inelastic events.
SCATTERING OF THE HARMONIC STRESS WAVE BY CRACKS IN FUNCTIONALLY GRADED PIEZOELECTRIC MATERIALS
Institute of Scientific and Technical Information of China (English)
Ma Li; Nie Wu; Wu Linzhi; Zhou Zhengong
2005-01-01
The present paper considers the scattering of the time harmonic stress wave by a single crack and two collinear cracks in functionally graded piezoelectric material (FGPM).It is assumed that the properties of the FGPM vary continuously as an exponential function.By using the Fourier transform and defining the jumps of displacements and electric potential components across the crack surface as the unknown functions, two pairs of dual integral equations are derived. To solve the dual integral equations, the jumps of the displacement and electric potential components across the crack surface are expanded in a series of Jacobi polynomials.Numerical examples are provided to show the influences of material properties on the dynamic stress and the electric displacement intensity factors.
Milli, J.; Vigan, A.; Mouillet, D.; Lagrange, A.-M.; Augereau, J.-C.; Pinte, C.; Mawet, D.; Schmid, H. M.; Boccaletti, A.; Matrà, L.; Kral, Q.; Ertel, S.; Chauvin, G.; Bazzon, A.; Ménard, F.; Beuzit, J.-L.; Thalmann, C.; Dominik, C.; Feldt, M.; Henning, T.; Min, M.; Girard, J. H.; Galicher, R.; Bonnefoy, M.; Fusco, T.; de Boer, J.; Janson, M.; Maire, A.-L.; Mesa, D.; Schlieder, J. E.; SPHERE Consortium
2017-03-01
Context. HR 4796 A is surrounded by a debris disc, observed in scattered light as an inclined ring with a high surface brightness. Past observations have raised several questions. First, a strong brightness asymmetry detected in polarised reflected light has recently challenged our understanding of scattering by the dust particles in this system. Secondly, the morphology of the ring strongly suggests the presence of planets, although no planets have been detected to date. Aims: We aim here at measuring with high accuracy the morphology and photometry of the ring in scattered light, in order to derive the phase function of the dust and constrain its near-infrared spectral properties. We also want to constrain the presence of planets and set improved constraints on the origin of the observed ring morphology. Methods: We obtained high-angular resolution coronagraphic images of the circumstellar environment around HR 4796 A with VLT/SPHERE during the commissioning of the instrument in May 2014 and during guaranteed-time observations in February 2015. The observations reveal for the first time the entire ring of dust, including the semi-minor axis that was previously hidden either behind the coronagraphic spot or in the speckle noise. Results: We determine empirically the scattering phase function of the dust in the H band from 13.6° to 166.6°. It shows a prominent peak of forward scattering, never detected before, for scattering angles below 30°. We analyse the reflectance spectra of the disc from the 0.95 μm to 1.6 μm, confirming the red colour of the dust, and derive detection limits on the presence of planetary mass objects. Conclusions: We confirm which side of the disc is inclined towards the Earth. The analysis of the phase function, especially below 45°, suggests that the dust population is dominated by particles much larger than the observation wavelength, of about 20 μm. Compact Mie grains of this size are incompatible with the spectral energy
A Fast Iterative Method for Chandrasekhar's H-functions for General Laws of Scattering
Kawabata, Kiyoshi
2016-01-01
This work shows that notable acceleration of the speed of calculating Chandrasekhar's H-functions for general laws of scattering with an iterative method can be realized by supplying a starting pproximation produced by the following procedure: (i) in the cases of azimuth-angle independent Fourier components, values of the isotropic scattering H-function given by an accurate yet simple-to-apply formula, in particular, the one by Kawabata and Limaye (Astrophys. and Space Sci. Vol. 332, 365-371, 2011 DOI 10.1007/s10509-010-0512-x; see also Astrophys. and Space Sci. Vol. 348, 601, 2013 DOI 10.1007/1009-013-1589-9, for erratum), and (ii) for azimuth-angle dependent Fourier components, an already obtained solution of the next lower order term. The paper has been published in Astrophys. and Space Sci. Vol. 358, 32-38 (2015) DOI 10.1007/s10509-015-2434-0, and the final publication is available at link.springer.com.
Rat Islet Isograft Function. Effect of Graft Volume and Transplantation Site
Suylichem, Paul T.R. van; Strubbe, Jan H.; Houwing, Harmina; Wolters, Gerrit H.J.; Schilfgaarde, Reinout van
1994-01-01
Islet isograft function was analyzed after transplantation of 4 well-defined endocrine volumes (12.5%, 25%, 50%, and 100% of the endocrine volume in the normal adult rat pancreas) to 3 different sites (kidney, liver, and spleen). Graft function was tested in unanesthetized, unstressed rats by the re
Tsui, Po-Hsiang; Wang, Shyh-Hau
2004-10-01
The effect of transducer characteristics on the sensitivity of the Nakagami parameter to detect the variation of scatterer concentrations was studied. The rationale for this study stems from our pilot results which showed that the Nakagami parameters, estimated using a nonfocused transducer were not as sensitive as those of measurements using a commercial ultrasonic scanner in previous reports. This discrepancy may be attributed to the effects of transducer characteristics relative to the size of the resolution cell as verified by measurements of phantoms and 2-D computer simulations. The Nakagami parameter as a function of scatterer concentration was calculated using backscattered signals acquired from the scattering medium of different scatterer concentrations ranging from 2 to 32 scatterers/mm(3) using both 5 MHz nonfocused and focused transducers. Experimental and simulation results obtained from the nonfocused transducer represent that their respective Nakagami parameters increased from 1.17 to 1.31 and from 0.82 to 1.01 corresponding to the increase of scatterer concentrations. For the results obtained from the focused transducer, their average Nakagami parameters increased from 0.27 to 0.72 and from 0.33 to 0.81. These consistent results demonstrated that Nakagami parameter estimated using a focused transducer tends to be more sensitive than that by a nonfocused transducer to detect the variation of low scatterer concentration. This difference is fully due to the effect of transducer characteristics associated with the effective number of scatterers in the resolution cell.
Guasp, J.; Pastor, I.; Álvarez-Estrada, R. F.; Castejón, F.
2015-02-01
Analytical results obtained recently of the ab-initio classical incoherent Thomson Scattering (TS) spectrum from a single-electron (Alvarez-Estrada et al 2012 Phys. Plasmas 19 062302) have been numerically implemented in a paralelized code to efficiently compute the TS emission from a given electron distribution function, irrespective of its characteristics and/or the intensity of the incoming radiation. These analytical results display certain differences, when compared with other authors, in the general case of incoming linearly and circularly polarized radiation and electrons with arbitrary initial directions. We regard such discrepancies and the ubiquitous interest in TS as motivations for this work. Here, we implement some analytical advances (like generalized Bessel functions for incoming linearly polarized radiation) in TS. The bulk of this work reports on the efficient computation of TS spectra (based upon our analytical approach), for an electron population having an essentially arbitrary distribution function and for both incoming linearly and circularly polarized radiation. A detailed comparison between the present approach and a previous Monte Carlo one (Pastor et al 2011 Nuclear Fusion 51 043011), dealing with the ab-initio computation of TS spectra, is reported. Both approaches are shown to fully agree with each other. As key computational improvements, the analytical technique yields a × 30 to × 100 gain in computation time and is a very flexible tool to compute the scattered spectrum and eventually the scattered electromagnetic fields in the time domain. The latter are computed explicitly here for the first time, as far as we know. Scaling laws for the power integrated over frequency versus initial kinetic energy are studied for the case of isotropic and monoenergetic electron distribution functions and their potential application as diagnostic tools for high-energy populations is briefly discussed. Finally, we discuss the application of these
LOFT reflood as a function of accumulator initial gas volume
Energy Technology Data Exchange (ETDEWEB)
Rhodes, H.F.
1978-06-01
The effect of the initial gas volume in the LOFT accumulators on the time to start of core reflood, after a LOCA, has been studied. The bases of the calculations are the data used and results presented in the Safety Analysis Report, Rev.1, August 1977, and the data in the RELAP and TOODEE2 program input and output listings. The results of this study show that an initial nitrogen volume of 12 cu ft, or more (at 600 psig initial pressure), would cause start of core reflood in time to prevent the cladding temperature from reaching 2200/sup 0/F. The 12 cu ft initial volume will expand from 600 psig, initial pressure, to about 10 psig (containment pressure shortly after start of LOCA is approximately 8 psig) when all ECC liquid has been expelled from the accumulator. This pressure margin is considered too small; the ECC flowrate will be zero before the accumulator is empty.
Neutron scattering from fractals
DEFF Research Database (Denmark)
Kjems, Jørgen; Freltoft, T.; Richter, D.
1986-01-01
The scattering formalism for fractal structures is presented. Volume fractals are exemplified by silica particle clusters formed either from colloidal suspensions or by flame hydrolysis. The determination of the fractional dimensionality through scattering experiments is reviewed, and recent small...
Mao, Shi-Chun; Wu, Zhen-Sen
2008-12-01
An exact solution to the two-dimensional scattering properties of an anisotropic elliptic cylinder for transverse electric polarization is presented. The internal field in an anisotropic elliptic cylinder is expressed as integral representations of Mathieu functions and Fourier series. The coefficients of the series expansion are obtained by imposing boundary conditions on the anisotropic-free-space interface. A matrix is developed to solve the nonorthogonality properties of Mathieu functions at the interface between two different media. Numerical results are given for the bistatic radar cross section and the amplitude of the total magnetic field along the x and y axes. The result is in agreement with that available as expected when an elliptic cylinder degenerates to a circular one.
Directory of Open Access Journals (Sweden)
A. Bayat
2013-04-01
Full Text Available Aerosol optical depth, Ångström exponent, single scattering albedo, and polarized phase function have been retrieved from polarized sun-photometer measurements for atmosphere of Zanjan (36.70° N, 48.51° E, and 1800 m a.m.s.l. from January 2010 to December 2012. The results show that the maximum value of aerosol polarized phase function as well as the polarized phase function retrieved for a specific scattering angle (i.e. 60°, are strongly correlated with the Ångström exponent. The latter one has a meaningful variations respect to the changes in the complex refractive index of the atmospheric aerosols. Furthermore the polarized phase function shows a moderate negative correlation respect to atmospheric aerosol optical depth and single scattering albedo. Therefore the polarized phase function can be regarded as a key parameter to characterize the atmospheric particles.
Bidirectional optical scattering facility
Federal Laboratory Consortium — Goniometric optical scatter instrument (GOSI)The bidirectional reflectance distribution function (BRDF) quantifies the angular distribution of light scattered from a...
Bidirectional optical scattering facility
Federal Laboratory Consortium — Goniometric optical scatter instrument (GOSI) The bidirectional reflectance distribution function (BRDF) quantifies the angular distribution of light scattered from...
Bartschat, K.; Mceachran, R. P.; Stauffer, A. D.
1990-01-01
An optical potential method was applied to the calculation of positron scattering from the noble gases in order to determine the effect of open excitation channels on the shape of differential scattering cross sections.
Chen, Lin; Wu, Wen-Bin; Liu, Pin-Yang; Xiao, Yun-Qing; Li, Guo-Peng; Liu, Yi-Ran; Jiang, Hao-Yu; Guo, Yan-Ling; Chen, Xi-Meng
2016-08-01
For Li+ and Na+ ions scattered from high work function metal surfaces, efficient neutralization is observed, and it cannot be explained by the conventional free electron model. In order to explain these experimental data, we investigate the velocity-dependent neutral fraction with the modified Brako-Newns (BN) model. The calculated results are in agreement with the experimental data. We find that the parallel velocity effect plays an important role in neutralizing the Li+ and Na+ ions for large angle scattering. The nonmonotonic velocity behavior of neutral fraction is strongly related to the distance-dependent coupling strength between the atomic level and metal states. Project supported by the National Natural Science Foundation of China (Grant Nos. 11405078 and 11474140), the Fundamental Research Funds for the Central Universities, China (Grant Nos. lzujbky-2014-169 and lzujbky-2015-244), the Project sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, the State Education Ministry, and the National Students’ Innovation and Entrepreneurship Training Program (Grant Nos. 201410730069 and 201510730078).
Left atrial volume and function in dogs with naturally occurring myxomatous mitral valve disease
DEFF Research Database (Denmark)
Höllmer, M.; Willesen, J. L.; Tolver, A.
2017-01-01
of cardiac compensation. Left atrial function in dogs with naturally occurring MMVD remains largely unexplored. The objective of this study was to evaluate LA volume and function in dogs with naturally occurring MMVD. ANIMALS: This prospective study included 205 client-owned dogs of different breeds, 114...... healthy dogs, and 91 dogs with MMVD of different disease severities. METHODS: Using two-dimensional echocardiography, the biplane area-length method was applied to assess LA volume and calculate volumetric indices of LA reservoir, conduit, and contractile function. RESULTS: Left atrial volume and LA...... stroke volume increased, whereas LA reservoir and contractile function decreased with increasing disease severity. A maximal LA volume dogs with chronic MMVD with a sensitivity of 96% and a specificity of 100...
The Effects of Scattered Light from Optical Components on Visual Function
2016-02-01
measures light scatter in the human eye (intraocular scatter) over a region from ~5° - 10° from the optical axis, or at an average scatter angle of...contrast sensitivity were measured in twelve subjects without and with eight different optical materials (OM) positioned in front of their right eye ... measure light scatter with and without an optical component in front of the eye and then calculating the difference, may provide data to derive a measure
Volume reflection angle study as a function of crystal curvature
Biryukov, V. M.
2016-10-01
We compare the volume reflection angles measured for protons and electrons over a wide energy range from 1 to 400 GeV in Si and Ge bent crystals at PNPI, IHEP, SLAC, and CERN with the predictions of FLUX and CATCH simulation codes based on binary collisions (FLUX) and continuum model (CATCH). We show good consistency of the data taken by many experimental groups, in good agreement with earlier published predictions.
Two Comments to Utilization of Structure Function Approach in Deep Inelastic Scattering Experiments
Kuraev, E A; Ilichev, A S
2002-01-01
The "returning to resonance" mechanism can be used to obtain the simple procedure of taking radiative corrections (RC) to deep inelastic scattering (DIS) cross sections into account in the framework of Drell-Yan picture. Iteration procedure is proposed. Kinematical region y\\to 1 can be described in the framework of Drell-Yan picture using the structure function approach. The large RC in the lowest order reflect the Sudakov form factor suppression, which can be taken into account in all orders of perturbation theory. Based on explicit calculation in two lowest orders of perturbation theory we construct the cross section in y\\to 1 region obeying renormalization group equations and including the Sudakov-like form factor suppression.
Effect of Sound Source Scattering on Measurement of Near-Field Head-Related Transfer Functions
Institute of Scientific and Technical Information of China (English)
YU Guang-Zheng; XIE Bo-Sun; RAO Dan
2008-01-01
@@ A simple spherical head and pulsating spherical sound source model are proposed to investigate the effect of multiple scattering between the head and the sound source on near-field head-related transfer function (HRTF) measurement. Multipole expansion method is used to calculate HRTFs of the model, then the relationships among the magnitude error of HRTF with frequency, source direction, source size, and the distance between the head centre and the sound source are analysed. The results show that to ensure the magnitude error of HRTF within 1.0 dB up to 20 kHz, for source distance not less than 0.15m or 0.20 m, the radius of the sound source should not exceed 0.03 m or 0.05 m, respectively. The conclusion suggests an appropriate size of sound source in near-field HRTF measurement.
Jost function description of near threshold resonances for coupled-channel scattering
Simbotin, I.; Côté, R.
2015-11-01
We study the effect of resonances near the threshold of low energy (ε) reactive scattering processes, and find an anomalous behavior of the s-wave cross sections. For reaction and inelastic processes, the cross section exhibits the energy dependence σ ∼ε - 3 / 2 instead of the standard Wigner's law threshold behavior σ ∼ε - 1 / 2 . Wigner's law is still valid as ε → 0 , but in a narrow range of energies. We illustrate these effects with two reactive systems, a low-reactive system (H2 + Cl) and a more reactive one (H2 + F). We provide analytical expressions, and explain this anomalous behavior using the properties of the Jost functions. We also discuss the implication of the reaction rate coefficients behaving as K ∼ 1 / T at low temperatures, instead of the expected constant rate of the Wigner regime in ultracold physics and chemistry.
Jost function description of near threshold resonances for coupled-channel scattering
Simbotin, I
2015-01-01
We study the effect of resonances near the threshold of low energy ($\\varepsilon$) reactive scattering processes, and find an anomalous behavior of the $s$-wave cross sections. For reaction and inelastic processes, the cross section exhibits the energy dependence $\\sigma\\sim\\varepsilon^{-3/2}$ instead of the standard Wigner's law threshold behavior $\\sigma\\sim\\varepsilon^{-1/2}$. Wigner's law is still valid as $\\varepsilon\\rightarrow 0$, but in a narrow range of energies. We illustrate these effects with two reactive systems, a low-reactive system (H$_2$ + Cl) and a more reactive one (H$_2$ + F). We provide analytical expressions, and explain this anomalous behavior using the properties of the Jost functions. We also discuss the implication of the reaction rate coefficients behaving as $K\\sim 1/T$ at low temperatures, instead of the expected constant rate of the Wigner regime in ultracold physics and chemistry.
Energy Technology Data Exchange (ETDEWEB)
Ward, Greg [Anywhere Software, Albany, CA (United States); Kurt, Murat [International Computer Institute, Ege University (Turkey); Bonneel, Nicolas [Harvard Univ., Cambridge, MA (United States)
2012-09-30
The utilization of real-world materials has been hindered by a lack of standards for sharing and interpreting measured data. This paper presents an XML representation and an Open Source C library to support bidirectional scattering distribution functions (BSDFs) in data-driven lighting simulation and rendering applications.The library provides for the efficient representation, query, and Monte Carlo sampling of arbitrary BSDFs in amodel-free framework. Currently, we support two BSDF data representations: one using a fixed subdivision of thehemisphere, and one with adaptive density. The fixed type has advantages for certain matrix operations, while theadaptive type can more accurately represent highly peaked data. We discuss advanced methods for data-drivenBSDF rendering for both types, including the proxy of detailed geometry to enhance appearance and accuracy.We also present an advanced interpolation method to reduce measured data into these standard representations.We end with our plan for future extensions and sharing of BSDF data.
Disorder effects on the static scattering function of star branched polymers
Directory of Open Access Journals (Sweden)
V. Blavatska
2012-10-01
Full Text Available We present an analysis of the impact of structural disorder on the static scattering function of f-armed star branched polymers in d dimensions. To this end, we consider the model of a star polymer immersed in a good solvent in the presence of structural defects, correlated at large distances r according to a power law ~r-a. In particular, we are interested in the ratio g(f of the radii of gyration of star and linear polymers of the same molecular weight, which is a universal experimentally measurable quantity. We apply a direct polymer renormalization approach and evaluate the results within the double ϵ = 4 - d, δ = 4 - a-expansion. We find an increase of g(f with an increasing δ. Therefore, an increase of disorder correlations leads to an increase of the size measure of a star relative to linear polymers of the same molecular weight.
Energy Technology Data Exchange (ETDEWEB)
Mukhopadhyay, S., E-mail: sanghamitra.mukhopadhyay@stfc.ac.uk [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Gutmann, M.J.; Jura, M. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Jochym, D.B. [Scientific Computing Department, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Jimenez-Ruiz, M. [Institut Laue Langevin, 6 rue Jules Horowitz 38042, Grenoble Cedex 9 (France); Sturniolo, S.; Refson, K. [Scientific Computing Department, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Fernandez-Alonso, F. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)
2013-12-12
Highlights: • We have presented results of neutron diffraction on croconic acid (CA). • We have presented results of inelastic neutron scattering (INS) spectra. • INS is compared with lattice dynamical simulations using density functional theory. • The prominent doublet in INS spectra around 1000 cm{sup −1} are from two hydrogen ions. • We identify the role of these H ions in the ferroelectricity of the CA crystal. - Abstract: A combination of neutron-scattering experiments and first-principles calculations using density-functional theory have been performed to explore the structural and dynamical properties of the single-component organic ferroelectric croconic acid. Neutron diffraction and spectroscopy have been used to determine the location and underlying vibrational motions of the hydrogen ions within the crystalline lattice, respectively. On the computational front we find that dispersion corrections within the generalised-gradient approximation are essential to obtain a satisfactory crystal structure for this organic solid. Two distinct types of hydrogen ions in the crystal also have been identified, located at the ‘hinge’ and ‘terrace’ positions of a pleated, accordion-like structure. Phonon calculations and simulated neutron spectra show that the prominent doublet observed at ca. 1000 cm{sup −1} arises from out-of-plane motions associated with these two types of hydrogen ions. Calculated Born-effective-charge tensors yield an anomalously high dynamic charge centered on the hydrogen ions at the hinges, a finding which serves to identify the primary motif underpinning ferroelectric behaviour in this novel material.
Fukutake, Naoki
2016-03-01
Coherent Raman scattering microspectroscopy, which includes coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS) microspectroscopy, permits label-free hyperspectral imaging. We report the theoretical study of the phase-shift effect of the impulse response function on the spectral and image-forming properties of coherent Raman scattering microspectroscopy. We show that the spectrum and image are influenced by not only the NA of objective for excitation (NA(ex)) but also that for signal collection (NA(col)), in association with the phase-shift effect. We discuss that, under the condition NA(ex)≠NA(col), both the spectrum and the image become deformed by the phase-shift effect, which can be applied to the direct measurement of the imaginary part of the nonlinear susceptibility in CARS spectroscopy. We point out that, even in SRS microscopy, the nonresonant background can contribute to the image formation and cause the artifact in the image.
Energy Technology Data Exchange (ETDEWEB)
Adams, T.; /Florida State U.; Batra, P.; /Columbia U.; Bugel, Leonard G.; /Columbia U.; Camilleri, Leslie Loris; /Columbia U.; Conrad, Janet Marie; /MIT; de Gouvea, A.; /Northwestern U.; Fisher, Peter H.; /MIT; Formaggio, Joseph Angelo; /MIT; Jenkins, J.; /Northwestern U.; Karagiorgi, Georgia S.; /MIT; Kobilarcik, T.R.; /Fermilab /Texas U.
2009-06-01
We extend the physics case for a new high-energy, ultra-high statistics neutrino scattering experiment, NuSOnG (Neutrino Scattering On Glass) to address a variety of issues including precision QCD measurements, extraction of structure functions, and the derived Parton Distribution Functions (PDFs). This experiment uses a Tevatron-based neutrino beam to obtain a sample of Deep Inelastic Scattering (DIS) events which is over two orders of magnitude larger than past samples. We outline an innovative method for fitting the structure functions using a parameterized energy shift which yields reduced systematic uncertainties. High statistics measurements, in combination with improved systematics, will enable NuSOnG to perform discerning tests of fundamental Standard Model parameters as we search for deviations which may hint of 'Beyond the Standard Model' physics.
Adams, T; Bugel, L; Camilleri, L; Conrad, J M; De Gouvêa, A; Fisher, P H; Formaggio, J A; Jenkins, J; Karagiorgi, G; Kobilarcik, T R; Kopp, S; Kyle, G; Loinaz, W A; Mason, D A; Milner, R; Moore, R; Morfín, J G; Nakamura, M; Naples, D; Nienaber, P; Olness, F I; Owens, J F; Pate, S F; Pronin, A; Seligman, W G; Shaevitz, M H; Schellman, H; Schienbein, I; Syphers, M J; Tait, T M P; Takeuchi, T; Tan, C Y; Van de Water, R G; Yamamoto, R K; Yu, J Y
2009-01-01
We extend the physics case for a new high-energy, ultra-high statistics neutrino scattering experiment, NuSOnG (Neutrino Scattering On Glass) to address a variety of issues including precision QCD measurements, extraction of structure functions, and the derived Parton Distribution Functions (PDFs). This experiment uses a Tevatron-based neutrino beam to obtain a sample of Deep Inelastic Scattering (DIS) events which is over two orders of magnitude larger than past samples. We outline an innovative method for fitting the structure functions using a parameterized energy shift which yields reduced systematic uncertainties. High statistics measurements, in combination with improved systematics, will enable NuSOnG to perform discerning tests of fundamental Standard Model parameters as we search for deviations which may hint of "Beyond the Standard Model" physics.
Renal infarct volume and renal function decline in acute and chronic phases.
Kagaya, Saeko; Yoshie, Ojima; Fukami, Hirotaka; Sato, Hiroyuki; Saito, Ayako; Takeuchi, Yoichi; Matsuda, Ken; Nagasawa, Tasuku
2017-03-10
Acute renal infarction (ARI) is a rare disease. ARI causes decline in renal function in both the acute and chronic phases. However, the correlation between the volume of the infarction and degree of renal function decline has not been fully investigated. Therefore, we aimed to examine the relationship between the volume of the infarction and degree of renal function decline. We performed a single-center, retrospective, observational study investigating clinical parameters and the volume of the infarction. The volume of the infarction was measured using reconstructed computed tomography data. A total of 39 patients (mean age, 72.6 ± 13.2 years; men, 59%) were enrolled. The median infarction volume was 45 mL (interquartile range, 14-91 mL). The volume of the infarction was significantly associated with the peak lactate dehydrogenase (LDH) level (median, 728 IU/L; interquartile range, 491-1227 U/L) (r = 0.58, p function decline in both acute and chronic phases (r = -0.44, -0.38, respectively, p LDH level was significantly correlated with the degree of renal function decline in the acute phase but not in the chronic phase (r = -0.35, -0.21; p function decline in ARI. Therefore, assessment of infarct volume in ARI is important.
Coridan, Robert H.; Schmidt, Nathan W.; Lai, Ghee Hwee; Abbamonte, Peter; Wong, Gerard C. L.
2012-03-01
Nanoconfined water and surface-structured water impacts a broad range of fields. For water confined between hydrophilic surfaces, measurements and simulations have shown conflicting results ranging from “liquidlike” to “solidlike” behavior, from bulklike water viscosity to viscosity orders of magnitude higher. Here, we investigate how a homogeneous fluid behaves under nanoconfinement using its bulk response function: The Green's function of water extracted from a library of S(q,ω) inelastic x-ray scattering data is used to make femtosecond movies of nanoconfined water. Between two confining surfaces, the structure undergoes drastic changes as a function of surface separation. For surface separations of ≈9 Å, although the surface-associated hydration layers are highly deformed, they are separated by a layer of bulklike water. For separations of ≈6 Å, the two surface-associated hydration layers are forced to reconstruct into a single layer that modulates between localized “frozen’ and delocalized “melted” structures due to interference of density fields. These results potentially reconcile recent conflicting experiments. Importantly, we find a different delocalized wetting regime for nanoconfined water between surfaces with high spatial frequency charge densities, where water is organized into delocalized hydration layers instead of localized hydration shells, and are strongly resistant to `freezing' down to molecular distances (<6 Å).
Changes in plasma volume and baroreflex function following resistance exercise
Ploutz, L. L.; Tatro, D. L.; Dudley, G. A.; Convertino, V. A.
1993-01-01
The dynamics of change in plasma volume (PV) and baroreflex responses have been reported over 24 h immediately following maximal cycle exercise. The purpose of this study was to determine if PV and baroreflex showed similar changes for 24 h after resistance exercise. Eight men were studied on 2 test days, 1 week apart. On 1 day, per cent change (% delta) in PV was estimated at 0,3, and 6 h after resistance exercise using haematocrit and haemoglobin. Baseline PV was measured 24 h after exercise using Evans blue dye. The carotid baroreceptor-cardiac reflex response was measured before, and 3, 6, 9, 12, and 24 h post-exercise. Each subject performed six sets of the bench press and leg press with 10 repetitions per set with a load that induced failure within each set. On a control day, the protocol was used without exercise. Plasma volume did not change during the control day. There was a 20% decrease in PV immediately post-exercise; the recovery of the PV was rapid and complete within 3 h. PV was 20% greater 24 h post-exercise than on the control day. There were no differences in any of the baroreflex measurements. Therefore, it is suggested that PV shifts may occur without altering baroreflex sensitivity.
Nikolaeva, I P; Kapranova, A S; Popova, V B; Lodyagin, A N; Frolova, T A
2015-01-01
The authors measured the changes of hemodynamics in 72 patients. It was also estimated a blood oxygenation and volume of liquid sectors of the organism in different degree of obesity before and after liposuction of the large volume. It was shown, that this operation facilitated to an improvement of respiratory lung function due to changes of pulmonary circulation.
Ramírez-García, Gonzalo; d'Orlyé, Fanny; Gutiérrez-Granados, Silvia; Martínez-Alfaro, Minerva; Mignet, Nathalie; Richard, Cyrille; Varenne, Anne
2015-12-01
Zinc gallate nanoparticles doped with chromium (III) (ZnGa1.995O4:Cr0.005) are innovative persistent luminescence materials with particular optical properties allowing their use for in vivo imaging. They can be excited in the tissue transparency window by visible photons and emit light for hours after the end of the excitation. This allows to observe the probe without any time constraints and without autofluorescence signals produced by biological tissues. Modification of the surface of these nanoparticles is essential to be colloidally stable not only for cell targeting applications but also for proper distribution in living organisms. The use of different methods for controlling and characterizing the functionalization process is imperative to better understand the subsequent interactions with biological elements. This work explores for the first time the characterization and optimization of a classic functionalization sequence, starting with hydroxyl groups (ZGO-OH) at the nanoparticle surface, followed by an aminosilane-functionalization intermediate stage (ZGO-NH2) before PEGylation (ZGO-PEG). Dynamic light scattering and laser doppler electrophoresis were used in combination with capillary electrophoresis to characterize the nanoparticle functionalization processes and control their colloidal and chemical stability. The hydrodynamic diameter, zeta potential, electrophoretic mobility, stability over time and aggregation state of persistent luminescence nanoparticles under physiological-based solution conditions have been studied for each functional state. Additionally, a new protocol to improve ZGO-NH2 stability based on a thermal treatment to complete covalent binding of (3-aminopropyl) triethoxysilane onto the particle surface has been optimized. This thorough control increases our knowledge on these nanoparticles for subsequent toxicological studies and ultimately medical application.
Kawabata, Kiyoshi
2016-12-01
This work shows that it is possible to calculate numerical values of the Chandrasekhar H-function for isotropic scattering at least with 15-digit accuracy by making use of the double exponential formula (DE-formula) of Takahashi and Mori (Publ. RIMS, Kyoto Univ. 9:721, 1974) instead of the Gauss-Legendre quadrature employed in the numerical scheme of Kawabata and Limaye (Astrophys. Space Sci. 332:365, 2011) and simultaneously taking a precautionary measure to minimize the effects due to loss of significant digits particularly in the cases of near-conservative scattering and/or errors involved in returned values of library functions supplied by compilers in use. The results of our calculations are presented for 18 selected values of single scattering albedo π0 and 22 values of an angular variable μ, the cosine of zenith angle θ specifying the direction of radiation incident on or emergent from semi-infinite media.
Kawabata, Kiyoshi
2016-01-01
This work shows that it is possible to calculate numerical values of the Chandrasekhar $H$-function for isotropic scattering at least with 15-digit accuracy by making use of the double exponential formula (DE-formula) of Takahashi and Mori (Publ. RIMS, Kyoto Univ. Vol. 9, 721, 1974) instead of the Gauss-Legendre quadrature employed in the numerical scheme of Kawabata and Limaye (Astrophys. Space Sci. Vol. 332, 365, 2011) and simultaneously taking a precautionary measure to minimize the effects due to loss of significant digits particularly in the cases of near-conservative scattering and/or errors involved in returned values of library functions supplied by compilers in use. The results of our calculations are presented for 18 selected values of single scattering albedo $\\varpi_0$ and 22 values of an angular variable $\\mu$, the cosine of zenith angle $\\theta$ specifying the direction of radiation incident on or emergent from semi-infinite media.
Kim, Jun Young; Kim, Jeongyong; Joo, Jinsoo
2016-11-28
Two-dimensional (2-D) transition metal dichalcogenides, such as MoSsub>2sub>, WSesub>2sub>, and WSsub>2sub>, are promising materials for application in field effect transistors, optoelectronics, and sensing devices. In this study, 2-D WSesub>2sub> samples with various numbers of layers were hybridized with functionalized gold nanoparticles (Au-NPs) to achieve surface-enhanced Raman scattering (SERS). The nanoscale Raman and photoluminescence spectra of the WSesub>2sub> layers and WSesub>2sub>/Au-NP hybrids were measured using a high-resolution laser confocal microscope. The WSesub>2sub> exhibited distinct optical characteristics depending on the number of WSesub>2sub> layers. The intensities of the Raman characteristic modes of the WSesub>2sub> layers were significantly enhanced after hybridization with functionalized Au-NPs, indicating the SERS effect. The SERS effect weakened with increasing the number of WSesub>2sub> layers. The SERS effect was more pronounced for mono- and bi-layer WSesub>2sub> systems compared with the multi-layer WSesub>2sub> systems.
Bodek, K.; Kępka, D.; Rozpędzik, D.; Zejma, J.; Kozela, A.
2017-04-01
A self-calibrating double-Mott polarimeter is proposed for measurement of the spin correlation function of relativistic electron pairs produced in Møller scattering. The polarization of outgoing electrons (appearing when the beam is polarized) is utilized for calibration of effective analyzing powers in the secondary Mott scattering used for spin analysis. The experiment will measure the newly introduced relative spin correlation function. This new observable can be measured with a significantly better accuracy than the regular spin correlation function in a small scale experiment. It is shown that both the spin correlation function and the relative spin correlation function are theoretically equivalent. A specific experimental data analysis scenario is proposed, which effectively eliminates the systematic effects related to the imperfect geometry and detector efficiency.
Pulmonary function tests correlated with thoracic volumes in adolescent idiopathic scoliosis.
Ledonio, Charles Gerald T; Rosenstein, Benjamin E; Johnston, Charles E; Regelmann, Warren E; Nuckley, David J; Polly, David W
2017-01-01
Scoliosis deformity has been linked with deleterious changes in the thoracic cavity that affect pulmonary function. The causal relationship between spinal deformity and pulmonary function has yet to be fully defined. It has been hypothesized that deformity correction improves pulmonary function by restoring both respiratory muscle efficiency and increasing the space available to the lungs. This research aims to correlate pulmonary function and thoracic volume before and after scoliosis correction. Retrospective correlational analysis between thoracic volume modeling from plain x-rays and pulmonary function tests was conducted. Adolescent idiopathic scoliosis patients enrolled in a multicenter database were sorted by pre-operative Total Lung Capacities (TLC) % predicted values from their Pulmonary Function Tests (PFT). Ten patients with the best and ten patients with the worst TLC values were included. Modeled thoracic volume and TLC values were compared before and 2 years after surgery. Scoliosis correction resulted in an increase in the thoracic volume for patients with the worst initial TLCs (11.7%) and those with the best initial TLCs (12.5%). The adolescents with the most severe pulmonary restriction prior to surgery strongly correlated with post-operative change in total lung capacity and thoracic volume (r(2) = 0.839; p pulmonary function, but no correlation was found in cases with normal pulmonary function. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:175-182, 2017.
Wang, Shouyu; Xue, Liang; Yan, Keding
2017-07-01
Light scattering from randomly rough surfaces is of great significance in various fields such as remote sensing and target identification. As numerical methods can obtain scattering distributions without complex setups and complicated operations, they become important tools in light scattering study. However, most of them suffer from huge computing load and low operating efficiency, limiting their applications in dynamic measurements and high-speed detections. Here, to overcome these disadvantages, microfacet slope probability density function based method is presented, providing scattering information without computing ensemble average from numerous scattered fields, thus it can obtain light scattering distributions with extremely fast speed. Additionally, it can reach high-computing accuracy quantitatively certificated by mature light scattering computing algorithms. It is believed the provided approach is useful in light scattering study and offers potentiality for real-time detections.
Function curve of the membranes that regulate amniotic fluid volume in sheep.
Faber, Job; Anderson, Debra; Hohimer, Roger; Yang, Qin; Giraud, George; Davis, Lowell
2005-07-01
Seven singleton 120-day fetal lambs were prepared with a shunt from the lung to the gastric end of the esophagus, a bladder catheter, and multiple amniotic fluid and vascular catheters. The urachus was ligated. Beginning 7 days later, amniotic fluid volumes were determined by drainage, followed by replacement with 1 liter of lactated Ringer (LR) solution. Urine flow into the amnion was measured continuously. In 14 of 27 experiments, amniotic fluid volumes were determined again 2 days after the inflow into the amnion had consisted of urine only and in 13 experiments after the inflow of urine had been supplemented by an intraamniotic infusion of LR solution. Intramembranous absorption was calculated from the inflows and the changes in volume between the beginning and end of each experiment. The relations between absorption rate and amniotic fluid volume, the "function curves," were highly individual. Urine production during the infusion of LR solution did not decrease, fetal plasma renin activity decreased (P amniotic fluid volume increased by 140% [SE (27%), P amniotic fluid per day. During the infusion of LR solution, the increase in the rate of absorption matched the rate of infusion (both in ml/h), with a regression coefficient of 0.75 (P amniotic fluid volumes, volume is not limited by the absorptive capacity of the amniochorion, and, at least in these preparations, the position of the function curve and not the natural rate of inflow was the major determinant of resting amniotic fluid volume.
Regional cerebellar volume and cognitive function from adolescence to late middle age.
Bernard, Jessica A; Leopold, Daniel R; Calhoun, Vince D; Mittal, Vijay A
2015-03-01
Cerebellar morphology and function have been implicated in a variety of developmental disorders, and in healthy aging. Although recent work has sought to characterize the relationships between volume and age in this structure during adolescence, young, and older adulthood, there have been no investigations of regional cerebellar volume from adolescence through late middle age. Middle age in particular has been largely understudied, and investigating this period of the lifespan may be especially important for our understanding of senescence. Understanding regional patterns of cerebellar volume with respect to age during this portion of the lifespan may provide important insight into healthy aging and cognitive function as well as pathology from adolescence into later life. We investigated regional cerebellar volume using a highly novel lobular segmentation approach in conjunction with a battery of cognitive tasks in a cross-sectional sample of 123 individuals from 12 to 65 years old. Our results indicated that regional cerebellar volumes show different patterns with respect to age. In particular, the more posterior aspect of the neocerebellum follows a quadratic "inverse-U" pattern while the vermis and anterior cerebellum follow logarithmic patterns. In addition, we quantified the relationships between age and a variety of cognitive assessments and found relationships between regional cerebellar volumes and performance. Finally, exploratory analyses of sex differences in the relationships between regional cerebellar volume, age, and cognition were investigated. Taken together, these results provide key insights into the development and aging of the human cerebellum, and its role in cognitive function across the lifespan.
Measurement of the proton structure function F2 at low Q2 in QED Compton scattering at HERA
Energy Technology Data Exchange (ETDEWEB)
Aktas, A. [DESY, Hamburg (Germany); Andreev, V. [Lebedev Physical Institute, Moscow (Russian Federation); Anthonis, T. [Inter-University Institute for High Energies ULB-VUB, Brussels, Universiteit Antwerpen, Antwerpen (Belgium)] (and others)
2004-09-30
The proton structure function F2(x,Q2) is measured in inelastic QED Compton scattering using data collected with the H1 detector at HERA. QED Compton events are used to access the kinematic range of very low virtualities of the exchanged photon, Q2, down to 0.5 GeV{sup 2}, and Bjorken x up to {approx}0.06, a region which has not been covered previously by inclusive measurements at HERA. The results are in agreement with the measurements from fixed target lepton-nucleon scattering experiments.
Measurement of the proton structure function F2 at low Q2 in QED Compton scattering at HERA
Aktas, A.; Andreev, V.; Anthonis, T.; Asmone, A.; Babaev, A.; Backovic, S.; Bähr, J.; Baranov, P.; Barrelet, E.; Bartel, W.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, Ch.; Berger, N.; Berndt, T.; Bizot, J. C.; Böhme, J.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brisson, V.; Bröker, H.-B.; Brown, D. P.; Bruncko, D.; Büsser, F. W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Caron, S.; Cassol-Brunner, F.; Cerny, K.; Chekelian, V.; Collard, C.; Contreras, J. G.; Coppens, Y. R.; Coughlan, J. A.; Cox, B. E.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Dau, W. D.; Daum, K.; Delcourt, B.; Demirchyan, R.; De Roeck, A.; Desch, K.; De Wolf, E. A.; Diaconu, C.; Dingfelder, J.; Dodonov, V.; Dubak, A.; Duprel, C.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Ellerbrock, M.; Elsen, E.; Erdmann, M.; Erdmann, W.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Fleischer, M.; Fleischmann, P.; Fleming, Y. H.; Flucke, G.; Flügge, G.; Fomenko, A.; Foresti, I.; Formánek, J.; Franke, G.; Frising, G.; Gabathuler, E.; Gabathuler, K.; Garutti, E.; Garvey, J.; Gayler, J.; Gerhards, R.; Gerlich, C.; Ghazaryan, S.; Goerlich, L.; Gogitidze, N.; Gorbounov, S.; Grab, C.; Grässler, H.; Greenshaw, T.; Gregori, M.; Grindhammer, G.; Gwilliam, C.; Haidt, D.; Hajduk, L.; Haller, J.; Hansson, M.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Henshaw, O.; Heremans, R.; Herrera, G.; Herynek, I.; Heuer, R.-D.; Hildebrandt, M.; Hiller, K. H.; Höting, P.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, H.; Kant, D.; Kapichine, M.; Karlsson, M.; Katzy, J.; Keller, N.; Kennedy, J.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Koblitz, B.; Korbel, V.; Kostka, P.; Koutouev, R.; Kropivnitskaya, A.; Kroseberg, J.; Kückens, J.; Kuhr, T.; Landon, M. P. J.; Lange, W.; Laštovička, T.; Laycock, P.; Lebedev, A.; Leißner, B.; Lemrani, R.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; List, B.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lueders, H.; Lüke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marks, J.; Marshall, R.; Martisikova, M.; Martyn, H.-U.; Maxfield, S. J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, J.; Michine, S.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morozov, I.; Morris, J. V.; Mozer, M. U.; Müller, K.; Murín, P.; Nagovizin, V.; Naroska, B.; Naumann, J.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nikitin, D.; Nowak, G.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J. E.; Ossoskov, G.; Ozerov, D.; Pascaud, C.; Patel, G. D.; Peez, M.; Perez, E.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Plačakytė, R.; Pöschl, R.; Portheault, B.; Povh, B.; Raicevic, N.; Ratiani, Z.; Reimer, P.; Reisert, B.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Rybicki, K.; Sankey, D. P. C.; Sauvan, E.; Schätzel, S.; Scheins, J.; Schilling, F.-P.; Schleper, P.; Schmidt, S.; Schmitt, S.; Schneider, M.; Schoeffel, L.; Schöning, A.; Schröder, V.; Schultz-Coulon, H.-C.; Schwanenberger, C.; Sedlák, K.; Sefkow, F.; Sheviakov, I.; Shtarkov, L. N.; Sirois, Y.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, A.; Spitzer, H.; Stamen, R.; Stella, B.; Stiewe, J.; Strauch, I.; Straumann, U.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Tomasz, F.; Traynor, D.; Truöl, P.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Uraev, A.; Urban, M.; Usik, A.; Utkin, D.; Valkár, S.; Valkárová, A.; Vallée, C.; Van Mechelen, P.; Van Remortel, N.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vest, A.; Vinokurova, S.; Volchinski, V.; Wacker, K.; Wagner, J.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Werner, N.; Wessels, M.; Wessling, B.; Winter, G.-G.; Wissing, Ch.; Woehrling, E.-E.; Wolf, R.; Wünsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Žáček, J.; Zálešák, J.; Zhang, Z.; Zhokin, A.; Zohrabyan, H.; Zomer, F.; H1 Collaboration
2004-09-01
The proton structure function F2 (x,Q2) is measured in inelastic QED Compton scattering using data collected with the H1 detector at HERA. QED Compton events are used to access the kinematic range of very low virtualities of the exchanged photon, Q2, down to 0.5 GeV2, and Bjorken x up to ∼0.06, a region which has not been covered previously by inclusive measurements at HERA. The results are in agreement with the measurements from fixed target lepton-nucleon scattering experiments.
Institute of Scientific and Technical Information of China (English)
WU Jiuhui; WANG Yaojun; LI Taibao
2004-01-01
A kind of addition formulae for the spherical wave functions is generated by using the bicentric expansion of Green function in spherical coordinates. For an acoustical system with multiple spheres, the addition formulae permit the field expansions all referred to the center of one of the spheres, whose boundary conditions can be consequently used to study the multiple scattering easily. The two-sphere acoustical system with different boundary conditions is considered and the field scattered by each sphere can be obtained by solving an infinite set of two linear, complex, algebraic equations, whose coefficients are coupled through double sums in the spherical wave functions. Finally, the form functions of two spheres insonified by a plane wave at arbitrary angles of incidence are calculated and the addition formulae presented are validated by comparing the corresponding numerical results with those of the existing literature.
Functionality and Performance Visualization of the Distributed High Quality Volume Renderer (HVR)
Shaheen, Sara
2012-07-01
Volume rendering systems are designed to provide means to enable scientists and a variety of experts to interactively explore volume data through 3D views of the volume. However, volume rendering techniques are computationally intensive tasks. Moreover, parallel distributed volume rendering systems and multi-threading architectures were suggested as natural solutions to provide an acceptable volume rendering performance for very large volume data sizes, such as Electron Microscopy data (EM). This in turn adds another level of complexity when developing and manipulating volume rendering systems. Given that distributed parallel volume rendering systems are among the most complex systems to develop, trace and debug, it is obvious that traditional debugging tools do not provide enough support. As a consequence, there is a great demand to provide tools that are able to facilitate the manipulation of such systems. This can be achieved by utilizing the power of compute graphics in designing visual representations that reflect how the system works and that visualize the current performance state of the system.The work presented is categorized within the field of software Visualization, where Visualization is used to serve visualizing and understanding various software. In this thesis, a number of visual representations that reflect a number of functionality and performance aspects of the distributed HVR, a high quality volume renderer system that uses various techniques to visualize large volume sizes interactively. This work is provided to visualize different stages of the parallel volume rendering pipeline of HVR. This is along with means of performance analysis through a number of flexible and dynamic visualizations that reflect the current state of the system and enables manipulation of them at runtime. Those visualization are aimed to facilitate debugging, understanding and analyzing the distributed HVR.
V-T theory for the self-intermediate scattering function in a monatomic liquid
Wallace, Duane C.; Chisolm, Eric D.; De Lorenzi-Venneri, Giulia
2017-02-01
In V-T theory the atomic motion is harmonic vibrations in a liquid-specific potential energy valley, plus transits, which move the system rapidly among the multitude of such valleys. In its first application to the self intermediate scattering function (SISF), V-T theory produced an accurate account of molecular dynamics (MD) data at all wave numbers q and time t. Recently, analysis of the mean square displacement (MSD) resolved a crossover behavior that was not observed in the SISF study. Our purpose here is to apply the more accurate MSD calibration to the SISF, and assess the results. We derive and discuss the theoretical equations for vibrational and transit contributions to the SISF. The time evolution is divided into three successive intervals: the vibrational interval when the vibrational contribution alone accurately accounts for the MD data; the crossover when the vibrational contribution saturates and the transit contribution becomes resolved; and the diffusive interval when the transit contribution alone accurately accounts for the MD data. The resulting theoretical error is extremely small at all q and t. V-T theory is compared to mode-coupling theories for the MSD and SISF, and to recent developments in Brownian motion experiments and theory.
Role of Möbius constants and scattering functions in Cachazo-He-Yuan scalar amplitudes
Lam, C. S.; Yao, York-Peng
2016-05-01
The integration over the Möbius variables leading to the Cachazo-He-Yuan double-color n -point massless scalar amplitude are carried out one integral at a time. Möbius invariance dictates the final amplitude to be independent of the three Möbius constants σr,σs,σt, but their choice affects integrations and the intermediate results. The effect of the Möbius constants, which will be held finite but otherwise arbitrary, the two sets of colors, and the scattering functions on each integration is investigated. A general systematic way to carry out the n -3 integrations is explained, each exposing one of the n -3 propagators of a single Feynman diagram. Two detailed examples are shown to illustrate the procedure, one a five-point amplitude, and the other a nine-point amplitude. Our procedure does not generate intermediate spurious poles, in contrast to what is common by choosing Möbius constants at 0, 1, and ∞ .
Gradual collapse of nuclear wave functions regulated by frequency tuned X-ray scattering.
Ignatova, Nina; Cruz, Vinícius V; Couto, Rafael C; Ertan, Emelie; Zimin, Andrey; Guimarães, Freddy F; Polyutov, Sergey; Ågren, Hans; Kimberg, Victor; Odelius, Michael; Gel'mukhanov, Faris
2017-03-07
As is well established, the symmetry breaking by isotope substitution in the water molecule results in localisation of the vibrations along one of the two bonds in the ground state. In this study we find that this localisation may be broken in excited electronic states. Contrary to the ground state, the stretching vibrations of HDO are delocalised in the bound core-excited state in spite of the mass difference between hydrogen and deuterium. The reason for this effect can be traced to the narrow "canyon-like" shape of the potential of the state along the symmetric stretching mode, which dominates over the localisation mass-difference effect. In contrast, the localisation of nuclear motion to one of the HDO bonds is preserved in the dissociative core-excited state . The dynamics of the delocalisation of nuclear motion in these core-excited states is studied using resonant inelastic X-ray scattering of the vibrationally excited HDO molecule. The results shed light on the process of a wave function collapse. After core-excitation into the state of HDO the initial wave packet collapses gradually, rather than instantaneously, to a single vibrational eigenstate.
Intermediate scattering function for macromolecules in solutions probed by neutron spin echo.
Liu, Yun
2017-02-01
The neutron-spin-echo method (NSE) is a powerful technique for studying internal dynamics of macromolecules in solutions because it can simultaneously probe length and time scales comparable to intramolecular density fluctuations of macromolecules. Recently, there has been increased, strong interest in studying protein internal motions using NSE. The coherent intermediate scattering function (ISF) measured by NSE depends on internal, rotational, and translational motions of macromolecules in solutions. It is thus critical, but highly nontrivial, to separate the internal motion from other motions in order to properly understand protein internal dynamics. Even though many experiments are performed at relatively high concentrations, current theories of calculating the ISF of concentrated protein solutions are either inaccurate or flawed by incorrect assumptions for realistic protein systems with anisotropic shapes. Here, a theoretical framework is developed to establish the quantitative relationship of different motions included in the ISF. This theory based on the dynamic decoupling approximation is applicable to a wide range of protein concentrations, including dilute cases. It is also, in general, useful for studying many other types of macromolecule systems studied by NSE.
Wan, Mingming; Liu, Zhiming; Li, Shaoxin; Yang, Biwen; Zhang, Wen; Qin, Xiaochu; Guo, Zhouyi
2013-07-01
Herein we describe a self-assembly synthesis of graphene oxide/Ag nanoparticles nano-composites (GO/CS/AgNPs) by non-covalent attachment of AgNPs to chitosan (CS) functionalized graphene oxide (GO) sheets. The negatively charged AgNPs are prone to form aggregates on GO/CS via electrostatic interaction, which is extremely beneficial to the surface-enhanced Raman scattering (SERS) detection of aromatic molecules. Taking advantage of the enrichment of target molecules on GO, the obtained hybrids exhibit strong SERS activity to aromatic molecules (trypan blue and methylene blue). Furthermore, SERS signals of a negatively charged molecule (trypan blue) are stronger than signals of a positively charged molecule (methylene blue) due to the different adsorption capacity of GO/CS/AgNPs for the two opposite charged molecules through electrostatic interaction. Moreover, GO/CS/AgNPs remarkably enhance the main peaks of l-phenylalanine, in comparison with the silver nanoparticles, showing great potential for biomedical applications.
Intermediate scattering function for macromolecules in solutions probed by neutron spin echo
Liu, Yun
2017-02-01
The neutron-spin-echo method (NSE) is a powerful technique for studying internal dynamics of macromolecules in solutions because it can simultaneously probe length and time scales comparable to intramolecular density fluctuations of macromolecules. Recently, there has been increased, strong interest in studying protein internal motions using NSE. The coherent intermediate scattering function (ISF) measured by NSE depends on internal, rotational, and translational motions of macromolecules in solutions. It is thus critical, but highly nontrivial, to separate the internal motion from other motions in order to properly understand protein internal dynamics. Even though many experiments are performed at relatively high concentrations, current theories of calculating the ISF of concentrated protein solutions are either inaccurate or flawed by incorrect assumptions for realistic protein systems with anisotropic shapes. Here, a theoretical framework is developed to establish the quantitative relationship of different motions included in the ISF. This theory based on the dynamic decoupling approximation is applicable to a wide range of protein concentrations, including dilute cases. It is also, in general, useful for studying many other types of macromolecule systems studied by NSE.
Manyari, D E; Kostuk, W J; Purves, P
1983-07-01
To assess the effects of pericardial effusion on ventricular performance and volumes, electrocardiographically gated blood pool cardiac scintigraphy was performed immediately before and after 14 pericardiocenteses in 10 patients, 7 men and 3 women, aged 28 to 73 years (mean 50). Cardiac tamponade was present in 5 patients. After removal of 140 to 1,100 ml of pericardial fluid (527 +/- 305 ml [mean +/- standard deviation]), left ventricular (LV) ejection fraction increased from 63 +/- 5 to 64 +/- 4% (p greater than 0.05) and right ventricular (RV) ejection fraction decreased from 47 +/- 4 to 46 +/- 2% (p greater than 0.05). LV end-diastolic and end-systolic volumes increased (p less than 0.01) by 28 and 33%, and RV volumes by 40 and 43%, respectively. There were 8 patients with normal LV function (ejection fraction greater than 60%) and 6 patients with subnormal LV function. Changes in ejection fraction were nonsignificant in the 4 subgroups. LV end-diastolic volume changes were more marked (p less than 0.01) in patients with cardiac tamponade (+ 56%) than in those without tamponade (+ 17%), and in those with normal LV function (+ 36%) than in those with subnormal LV function (+ 21%). RV end-diastolic volume increased more markedly (p less than 0.05) in patients with tamponade (+ 72%) than in those without tamponade (+ 23%), but were similar in patients with normal (+ 38%) and abnormal (+ 43%) LV function. After pericardiocentesis, RV volume increased more markedly than did LV volume. Thus, hemodynamic and clinical improvement after pericardiocentesis may be related only to an increase in stroke volume. RV and LV ejection fraction, a measure of myocardial contractility, was not affected significantly by the presence of pericardial effusion, even in those patients who had cardiac tamponade.
Directory of Open Access Journals (Sweden)
Atsuo Kuniba
2010-01-01
Full Text Available We study an integrable vertex model with a periodic boundary condition associated with U_q(A_n^{(1} at the crystallizing point q=0. It is an (n+1-state cellular automaton describing the factorized scattering of solitons. The dynamics originates in the commuting family of fusion transfer matrices and generalizes the ultradiscrete Toda/KP flow corresponding to the periodic box-ball system. Combining Bethe ansatz and crystal theory in quantum group, we develop an inverse scattering/spectral formalism and solve the initial value problem based on several conjectures. The action-angle variables are constructed representing the amplitudes and phases of solitons. By the direct and inverse scattering maps, separation of variables into solitons is achieved and nonlinear dynamics is transformed into a straight motion on a tropical analogue of the Jacobi variety. We decompose the level set into connected components under the commuting family of time evolutions and identify each of them with the set of integer points on a torus. The weight multiplicity formula derived from the q=0 Bethe equation acquires an elegant interpretation as the volume of the phase space expressed by the size and multiplicity of these tori. The dynamical period is determined as an explicit arithmetical function of the n-tuple of Young diagrams specifying the level set. The inverse map, i.e., tropical Jacobi inversion is expressed in terms of a tropical Riemann theta function associated with the Bethe ansatz data. As an application, time average of some local variable is calculated.
Trigg, Edward B.; Middleton, L. Robert; Aitken, Brian S.; Azoulay, Jason; Murtagh, Dustin; Wagener, Kenneth B.; Cordaro, Joseph; Winey, Karen I.
Morphological evolution during tensile deformation of semi-crystalline polymers is often described qualitatively. The layered crystal structures of precise copolymers, in which functional groups are bonded at precise intervals along the polymer backbone, allow for quantitative fitting of oriented X-ray scattering peaks to provide additional information. The crystallites in precise poly(ethylene-co-acrylic acid) align with the acid group layers' normal vector parallel to the tensile direction, while those in precise poly(ethylene-co-imidazolium bromide) align with the layers' normal vector perpendicular to the tensile direction. We present fits of in situ X-ray scattering during tensile deformation of semi-crystalline precise copolymers, to quantify the size, shape, and degree of orientation of the crystallites during the deformation process. Mathematical descriptions of the X-ray scattering in these two cases is explored, and a physical explanation for the difference in alignment direction is proposed.
Directory of Open Access Journals (Sweden)
A. Bayat
2013-10-01
Full Text Available The polarized phase function of atmospheric aerosols has been investigated for the atmosphere of Zanjan, a city in northwest Iran. To do this, aerosol optical depth, Ångström exponent, single-scattering albedo, and polarized phase function have been retrieved from the measurements of a Cimel CE 318-2 polarized sun-photometer from February 2010 to December 2012. The results show that the maximum value of aerosol polarized phase function as well as the polarized phase function retrieved for a specific scattering angle (i.e., 60° are strongly correlated (R = 0.95 and 0.95, respectively with the Ångström exponent. The latter has a meaningful variation with respect to the changes in the complex refractive index of the atmospheric aerosols. Furthermore the polarized phase function shows a moderate negative correlation with respect to the atmospheric aerosol optical depth and single-scattering albedo (R = −0.76 and −0.33, respectively. Therefore the polarized phase function can be regarded as a key parameter to characterize the atmospheric particles of the region – a populated city in the semi-arid area and surrounded by some dust sources of the Earth's dust belt.
Assessment of left atrial volume and function in patients with permanent atrial fibrillation
DEFF Research Database (Denmark)
Agner, Bue F Ross; Kühl, Jørgen Tobias; Linde, Jesper James
2014-01-01
Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with substantial morbidity and mortality. AF is associated with enlargement of the left atrium (LA), and the LA volume has important prognostic implications for the disease. The objective of the study was to determine how ...... measurements of LA volume and function obtained by transthoracic echocardiography (TTE), cardiac magnetic resonance (CMR), and 320-slice multi-detector computed tomography (MDCT) correlate in patients with permanent AF....
Directory of Open Access Journals (Sweden)
Niva Kiran Verma
2016-05-01
Full Text Available Studies estimating canopy volume are mostly based on laborious and time-consuming field measurements; hence, there is a need for easier and convenient means of estimation. Accordingly, this study investigated the use of remotely sensed data (WorldView-2 and LiDAR for estimating tree height, canopy height and crown diameter, which were then used to infer the canopy volume of remnant eucalypt trees at the Newholme/Kirby ‘SMART’ farm in north-east New South Wales. A regression model was developed with field measurements, which was then applied to remote-sensing-based measurements. LiDAR estimates of tree dimensions were generally lower than the field measurements (e.g., 6.5% for tree height although some of the parameters (such as tree height may also be overestimated by the clinometer/rangefinder protocols used. The WorldView-2 results showed both crown projected area and crown diameter to be strongly correlated to canopy volume, and that crown diameter yielded better results (Root Mean Square Error RMSE 31% than crown projected area (RMSE 42%. Although the better performance of LiDAR in the vertical dimension cannot be dismissed, as suggested by results obtained from this study and also similar studies conducted with LiDAR data for tree parameter measurements, the high price and complexity associated with the acquisition and processing of LiDAR datasets mean that the technology is beyond the reach of many applications. Therefore, given the need for easier and convenient means of tree parameters estimation, this study filled a gap and successfully used 2D multispectral WorldView-2 data for 3D canopy volume estimation with satisfactory results compared to LiDAR-based estimation. The result obtained from this study highlights the usefulness of high resolution data for canopy volume estimations at different locations as a possible alternative to existing methods.
Zhang, Xi; Jiang, Hongrui
2015-03-09
Photo-self-charging cells (PSCs) are compact devices with dual functions of photoelectric conversion and energy storage. By introducing a scattering layer in polymer-based quasi-solid-state dye-sensitized solar cells, two-electrode PSCs with highly compact structure were obtained. The charge storage function stems from the formed ion channel network in the scattering layer/polymer electrolyte system. Both the photoelectric conversion and the energy storage functions are integrated in only the photoelectrode of such PSCs. This design of PSC could continuously output power as a solar cell with considerable efficiency after being photo-charged. Such PSCs could be applied in highly-compact mini power devices.
Relation of the volume of the olfactory bulb to psychophysical measures of olfactory function.
Mazal, Patricia Portillo; Haehner, Antje; Hummel, Thomas
2016-01-01
The aim of this review is to investigate whether changes in olfactory bulb volume relate to changes in specific olfactory functions. We studied currently available peer-reviewed articles on the volume of the human olfactory bulb that also included a psychophysical measure of olfactory function. In the present review, we observed a very clear and consistent correlation between general olfactory function and olfactory bulb (OB) volume. We were not able to find a clear relationship between a specific smell component and OB volume, even when analyzing pathologic conditions separately. In some cases, changes were observed for different subtests, but these changes did not significantly correlate with OB volume or had only a borderline correlation. In other cases, we found contradictory data. Several factors may contribute to the difficulties in finding correlations with the different components of smell: (1) the OB volume may be influenced by information from olfactory receptor neurons (bottom-up effect), information from central nervous system (top-down effect) and by direct damage; (2) most pathologic conditions affect more than one area of the olfactory pathway; (3) small sample sizes of hyposmic subjects were used. We believe that it is necessary to do further studies with larger numbers of subjects to answer the currently investigated question.
Strauss, R.; Rothe, J.; Angloher, G.; Bento, A.; Gütlein, A.; Hauff, D.; Kluck, H.; Mancuso, M.; Oberauer, L.; Petricca, F.; Pröbst, F.; Schieck, J.; Schönert, S.; Seidel, W.; Stodolsky, L.
2017-08-01
We discuss a small-scale experiment, called ν -cleus, for the first detection of coherent neutrino-nucleus scattering by probing nuclear-recoil energies down to the 10 eV regime. The detector consists of low-threshold CaWO_4 and Al_2O_3 calorimeter arrays with a total mass of about 10 g and several cryogenic veto detectors operated at millikelvin temperatures. Realizing a fiducial volume and a multi-element target, the detector enables active discrimination of γ , neutron and surface backgrounds. A first prototype Al_2O_3 device, operated above ground in a setup without shielding, has achieved an energy threshold of {˜ }20 eV and further improvements are in reach. A sensitivity study for the detection of coherent neutrino scattering at nuclear power plants shows a unique discovery potential (5σ ) within a measuring time of {\\lesssim }2 weeks. Furthermore, a site at a thermal research reactor and the use of a radioactive neutrino source are investigated. With this technology, real-time monitoring of nuclear power plants is feasible.
Directory of Open Access Journals (Sweden)
F Zolfagharpour
2012-03-01
Full Text Available In this paper, we calculate nuclear structure function and EMC effect of 40Ca and 56Fe nuclei. To achive the goals, we consider Fermi motion and binding energy contrbiution in the harmonic oscillator model. In this model, harmonic oscillator parameter ħω related to shells root mean square radius and for free nucleon structure functions, is obtained from GRV’s free nucleon structure functions. Then, we calculate differential cross section of lepton scattering from those nuclei at the E=4.8 GeV and E=4.032 GeV. The obtained results show good agreement with available experimental data.
Yu, Hsiu-Yu
2014-09-15
© the Partner Organisations 2014. We investigate the static structure factor S(q) of solvent-free nanoparticle-organic hybrid materials consisting of silica nanocores and space-filling polyethylene glycol coronas using a density-functional theory and small angle X-ray scattering measurements. The theory considers a bidisperse suspension of hard spheres with different radii and tethered bead-spring oligomers with different grafting densities to approximate the polydispersity effects in experiments. The experimental systems studied include pure samples with different silica core volume fractions and the associated mean corona grafting densities, and blends with different mixing ratios of the pure samples, in order to introduce varying polydispersity of corona grafting density. Our scattering experiments and theory show that, compared to the hard-sphere suspension with the same core volume fraction, S(q) for pure samples exhibit both substantially smaller values at small q and stronger particle correlations corresponding to a larger effective hard core at large q, indicating that the tethered incompressible oligomers enforce a more uniform particle distribution, and the densely grafted brush gives rise to an additional exclusionary effect between the nanoparticles. According to the theory, polydispersity in the oligomer grafting density controls the deviation of S(q) from the monodisperse system at smaller q, and the interplay of the enhanced effective core size and the entropic attraction among the particles is responsible for complex variations in the particle correlations at larger q. The successful comparison between the predictions and the measurements for the blends further suggests that S(q) can be used to assess the uniformity of grafting density in polymer-grafted nanoparticle materials. This journal is
Failure of the Volume Function in Granular Statistical Mechanics and an Alternative Formulation.
Blumenfeld, Raphael; Amitai, Shahar; Jordan, Joe F; Hihinashvili, Rebecca
2016-04-08
We first show that the currently accepted statistical mechanics for granular matter is flawed. The reason is that it is based on the volume function, which depends only on a minute fraction of all the structural degrees of freedom and is unaffected by most of the configurational microstates. Consequently, the commonly used partition function underestimates the entropy severely. We then propose a new formulation, replacing the volume function with a connectivity function that depends on all the structural degrees of freedom and accounts correctly for the entire entropy. We discuss the advantages of the new formalism and derive explicit results for two- and three-dimensional systems. We test the formalism by calculating the entropy of an experimental two-dimensional system, as a function of system size, and showing that it is an extensive variable.
Nillesen, Maartje M; van Dijk, Arie P J; Duijnhouwer, Anthonie L; Thijssen, Johan M; de Korte, Chris L
2016-02-01
Assessment of right ventricular (RV) function is known to be of diagnostic value in patients with RV dysfunction. Because of its complex anatomic shape, automated determination of the RV volume is difficult and strong reliance on geometric assumptions is not desired. A method for automated RV assessment was developed using three-dimensional (3-D) echocardiography without relying on a priori knowledge of the cardiac anatomy. A 3-D adaptive filtering technique that optimizes the discrimination between blood and myocardium was applied to facilitate endocardial border detection. Filtered image data were incorporated in a segmentation model to automatically detect the endocardial RV border. End-systolic and end-diastolic RV volumes, as well as ejection fraction, were computed from the automatically segmented endocardial surfaces and compared against reference volumes manually delineated by two expert cardiologists. The results reported good performance in terms of correlation and agreement with the results from the reference volumes.
Rousselle, Fabrice; Hébert, Mathieu; Hersch, Roger
2010-01-01
We consider the problem of predicting the spectral reflectance of paper samples immersed in ink mixtures of varying ink concentrations. Relying on an adapted version of the Kubelka-Munk theory, we predict the reflectances of the samples dyed by ink mixtures. We first derive a method to calculate the effective scattering coefficient of an inked paper sample as a function of its absorbance coefficient. Then we learn from a single sample the reduction in ink concentrations when two inks are mixe...
Institute of Scientific and Technical Information of China (English)
DUAN Chun-Gui; SHEN Peng-Nian; LI Guang-Lie
2006-01-01
By taking advantage of the model-independent nuclear parton distributions, the structure functions xF3(x, Q2)are calculated, in comparison with the experimental data from CCFR neutrino-nuclei charge current deep inelastic scattering. It is shown that shadowing and anti-shadowing effects occur in valence quark distributions for small and medium x regions, respectively. It is suggested that the neutrino experimental data should be employed in the future for pinning down the nuclear parton distributions.
Bollini, D; Benvenuti, Alberto C; Bozzo, M; Brun, R; Cvach, J; Dobrowolski, T; Fadeev, N G; Feltesse, J; Frabetti, P L; Gennow, H; Golutvin, I A; Goossens, M; Heiman, G; Jamnik, D; Kiryushin, Yu T; Kisselev, V S; Klein, M; Kopp, R; Krivokhizhin, V G; Kukhtin, V V; Maillard, J; Malasoma, J M; Meyer-Berkhout, U; Milsztajn, A; Monari, L; Navach, F; Navarria, Francesco Luigi; Nowak, Wolf-Dieter; Piemontese, L; Pilcher, J E; Renardy, J F; Sacquin, Yu; Savin, I A; Schinzel, D; Smadja, G; Smirnov, G I; Staude, A; Teichert, K M; Tirler, R; Verrecchia, P; Vesztergombi, G; Virchaux, M; Volodko, A G; Voss, R; Zácek, J; Zupancic, Crtomir
1981-01-01
Deep inelastic scattering cross sections have been measured with the CERN SPS muon beam at incident energies of 120 and 200 GeV. Approximately 10000 events at each energy used to obtain the structure function F/sub 2/(x, Q/sup 2/) in the kinematic region 0.3
Institute of Scientific and Technical Information of China (English)
WANG Jing; WANG Xinfang; XIE Mingxing; YANG Ya; LV Qing; YANG Ying; WANG Liangyu
2005-01-01
The optimal plane for measurement of the right ventricular (RV) volumes by real-time three-dimensional echocardiography (RT3DE) was determined and the feasibility and accuracy of RT3DE in studying RV systolic function was assessed. RV "Full volume" images were acquired by RT3DE in 22 healthy subjects. RV end-diastolic volumes (RVEDV) and end-systolic volumes (RVESV) were outlined using apical biplane, 4-plane, 8-plane, 16-plane offline separately. RVSV and RVEF were calculated. Meanwhile tricuspid annual systolic excursion (TASE) was measured by M-mode echo. LVSV was outlined by 2-D echo according to the biplane Simpsons rule. The results showed: (1) There was a good correlation between RVSV measured from series planes and LVSV from 2-D echo (r=0.73; r=0.69; r=0.63; r=0.66, P＜0.25-0. 0025); (2) There were significant differences between RVEDV in biplane and those in 4-, 8-, 16-plane (P＜0. 001). There was also difference between RV volume in 4-plane and that in 8-plane (P＜0.05), but there was no significant difference between RV volume in 8-plane and that in 16-plane (P＞0.05); (3) Inter-observers and intro-observers variability analysis showed that there were close agreements and relations for RV volumes (r=0. 986, P＜0. 001; r=0.93, P＜0. 001); (4) There was a significantly positive correlation of TASE to RVSV and RVEF from RT3DE (r=0.83; r=0.90). So RV volume measures with RT3DE are rapid, accurate and reproducible. In view of RVs complex shape,apical 8-plane method is better in clinical use. It may allow early detection of RV systolic function.
DEFF Research Database (Denmark)
Reardon, Hazel; Iversen, Bo Brummerstedt; Blichfeld, Anders Bank
Powder X-ray diffraction (PXRD) has been a steadfast tool for detailed crystal structure determination in thermoelectrics materials research. PXRD provides a description of the long-range periodic order, meanwhile, local structure information can be obtained from total scattering data, i.e., by m......Powder X-ray diffraction (PXRD) has been a steadfast tool for detailed crystal structure determination in thermoelectrics materials research. PXRD provides a description of the long-range periodic order, meanwhile, local structure information can be obtained from total scattering data, i.......e., by measuring both the Bragg and diffuse scattering from a sample. This method has rarely been exploited by the non-oxide thermoelectrics community. , , Treating total scattering data by the Pair Distribution Function method is a logical approach to understanding defects, disorder and amorphous components...... in thermoelectric materials. Moreover, in situ studies can enable an understanding of how high temperature influences the structure (and properties) at the local scale. If we can understand the local modifications in a structure prior to, during, and after restructuring as a thermoelectric material is exposed...
Energy Technology Data Exchange (ETDEWEB)
Chan Yuleung; Law Manyee; Howard, Robert [Chinese University of Hong Kong, Department of Diagnostic Radiology and Organ Imaging, Prince of Wales Hospital, Hong Kong (China); Li Chikong; Chik Kiwai [Chinese University of Hong Kong, Department of Paediatrics, Prince of Wales Hospital, Hong Kong (China)
2005-02-01
It is not known whether body weight alone can adjust for the volume of liver in the calculation of the chelating dose in {beta}-thalassaemia major patients, who frequently have iron overload and hepatitis. The hypothesis is that liver volume in children and adolescents suffering from {beta}-thalassaemia major is affected by ferritin level and liver function. Thirty-five {beta}-thalassaemia major patients aged 7-18 years and 35 age- and sex-matched controls had liver volume measured by MRI. Serum alanine aminotransferase (ALT) and ferritin levels were obtained in the thalassaemia major patients. Body weight explained 65 and 86% of the change in liver volume in {beta}-thalassaemia major patients and age-matched control subjects, respectively. Liver volume/kilogram body weight was significantly higher (P<0.001) in thalassaemia major patients than in control subjects. There was a significant correlation between ALT level and liver volume/kilogram body weight (r=0.55, P=0.001). Patients with elevated ALT had significantly higher liver volume/kilogram body weight (mean 42.9{+-}12 cm{sup 3}/kg) than control subjects (mean 23.4{+-}3.6 cm{sup 3}/kg) and patients with normal ALT levels (mean 27.4{+-}3.6 cm{sup 3}/kg). Body weight is the most important single factor for liver-volume changes in thalassaemia major patients, but elevated ALT also has a significant role. Direct liver volume measurement for chelation dose adjustment may be advantageous in patients with elevated ALT. (orig.)
Pulmonary blood volume and transit time in cirrhosis: relation to lung function
DEFF Research Database (Denmark)
Møller, Søren; Burchardt, H; Øgard, CG;
2006-01-01
not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis......BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... and in 12 controls. The lung function including diffusing capacity for carbon monoxide (DL, CO) was determined by conventional single breath technique. RESULTS: In the patients, PTT was shorter, 3.9+/-1.2 vs 5.7+/-1.0 s in the controls, P
Pulmonary blood volume and transit time in cirrhosis: relation to lung function
DEFF Research Database (Denmark)
Møller, Søren; Burchardt, H; Øgard, CG
2006-01-01
BACKGROUND/AIMS: In cirrhosis a systemic vasodilatation leads to an abnormal distribution of the blood volume with a contracted central blood volume. In addition, the patients have a ventilation/perfusion imbalance with a low diffusing capacity. As the size of the pulmonary blood volume (PBV) has...... not been determined separately we assessed PBV and pulmonary transit time (PTT) in relation to lung function in patients with cirrhosis and in controls. METHODS: Pulmonary and cardiac haemodynamics and transit times were determined by radionuclide techniques in 22 patients with alcoholic cirrhosis...... and in 12 controls. The lung function including diffusing capacity for carbon monoxide (DL, CO) was determined by conventional single breath technique. RESULTS: In the patients, PTT was shorter, 3.9+/-1.2 vs 5.7+/-1.0 s in the controls, P
Saenger, Victor M; Barrios, Fernando A; Martínez-Gudiño, María L; Alcauter, Sarael
2012-06-01
Resting state networks such as the default mode network have been widely reported. Although a plethora of information on its functional relevance has been generated, little is known about lateralization or hemisphere asymmetry within the DMN. We used high-resolution resting state fMRI and T1 3D data to investigate such asymmetries in two groups of healthy subjects, one right-handed and one left-handed. Independent component analysis and the dual regression approach were carried out to identify functional asymmetries, while voxel-based morphometry was used to identify structural asymmetries in grey matter volume within the DMN. Greater leftward functional connectivity was observed in the posterior cingulate gyrus (PCG) for both groups. Leftward functional asymmetry was observed in the thalamus and rightward functional asymmetries were observed in the middle frontal and middle/superior temporal gyrus in the right-handed group. Rightward asymmetries in grey matter volume were observed in the posterior portion of the PCG for both groups. The right-handed group exhibited leftward structural asymmetries in the anterior portion of the PCG and in the middle frontal and posterior portion of the middle temporal gyrus, while rightward asymmetries were observed in the posterior portion of the PCG and anterior portions of temporal regions. These results suggest that functional connectivity and grey matter volume are not equally distributed between hemispheres within the DMN, and that functional asymmetries are not always reflected or determined by structural asymmetries.
Energy Technology Data Exchange (ETDEWEB)
Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner (eds.)
2010-07-01
The following topics are dealt with: Neutron sources, neutron properties and elastic scattering, correlation functions measured by scattering experiments, symmetry of crystals, applications of neutron scattering, polarized-neutron scattering and polarization analysis, structural analysis, magnetic and lattice excitation studied by inelastic neutron scattering, macromolecules and self-assembly, dynamics of macromolecules, correlated electrons in complex transition-metal oxides, surfaces, interfaces, and thin films investigated by neutron reflectometry, nanomagnetism. (HSI)
Hippocampal volumes are important predictors for memory function in elderly women
Directory of Open Access Journals (Sweden)
Adolfsdottir Steinunn
2009-08-01
Full Text Available Abstract Background Normal aging involves a decline in cognitive function that has been shown to correlate with volumetric change in the hippocampus, and with genetic variability in the APOE-gene. In the present study we utilize 3D MR imaging, genetic analysis and assessment of verbal memory function to investigate relationships between these factors in a sample of 170 healthy volunteers (age range 46–77 years. Methods Brain morphometric analysis was performed with the automated segmentation work-flow implemented in FreeSurfer. Genetic analysis of the APOE genotype was determined with polymerase chain reaction (PCR on DNA from whole-blood. All individuals were subjected to extensive neuropsychological testing, including the California Verbal Learning Test-II (CVLT. To obtain robust and easily interpretable relationships between explanatory variables and verbal memory function we applied the recent method of conditional inference trees in addition to scatterplot matrices and simple pairwise linear least-squares regression analysis. Results APOE genotype had no significant impact on the CVLT results (scores on long delay free recall, CVLT-LD or the ICV-normalized hippocampal volumes. Hippocampal volumes were found to decrease with age and a right-larger-than-left hippocampal asymmetry was also found. These findings are in accordance with previous studies. CVLT-LD score was shown to correlate with hippocampal volume. Multivariate conditional inference analysis showed that gender and left hippocampal volume largely dominated predictive values for CVLT-LD scores in our sample. Left hippocampal volume dominated predictive values for females but not for males. APOE genotype did not alter the model significantly, and age was only partly influencing the results. Conclusion Gender and left hippocampal volumes are main predictors for verbal memory function in normal aging. APOE genotype did not affect the results in any part of our analysis.
Institute of Scientific and Technical Information of China (English)
Hideo Sakamoto; Yoshio Ogawa; Hideki Yoshida
2008-01-01
Aim: To evaluate the relationship between testicular function and testicular volume measured by using Prader orchidometry and ultrasonography (US) to determine the critical testicular volume indicating normal testicular func-tion by each method. Methods: Total testicular volume (right plus left testicular volume) was measured in 794 testes in 397 men with infertility (mean age, 35.6 years) using a Prader orchidometer and also by ultrasonography.Ultrasonographic testicular volumes were calculated as length×width×height×0.71. To evaluate volume-function relationships, patients were divided into 10 groups representing 5-mL increments of total testicular volume by each method from below 10 mL to 50 mL or more. Results: Mean total testicular volume based on Prader orchidometry and US were 36.8 mL and 26.3 mL, respectively. Semen volume, sperm density, total sperm count, total motile sperm count, and serum FSH, LH, and testosterone all correlated significantly with total testicular volume measured by either method. Mean sperm density was in the oligozoospermic range in patients with total testicular volume below 35 mL by orchidometry or below 20 mL by ultrasonography. Mean total sperm count was subnormal in patients with total testicular volume below 30 mL by orchidometry or under 20 mL by ultrasonography. Conclusion: Testicular volume measured by either ultrasonography or Prader orchidometry correlated significantly with testicular function.However, critical total testicular volume indicating normal or nearly normal testicular function was 30 mL to 35 mL using Prader orchidometer and 20 mL using ultrasonography. Prader orchidometry morphometrically and function-ally overestimated the testicular volume in comparison to US.
Brain volume and cognitive function in patients with revascularized coronary artery disease
Ottens, Thomas H; Hendrikse, Jeroen|info:eu-repo/dai/nl/266590268; Nathoe, Hendrik M|info:eu-repo/dai/nl/267961472; Biessels, Geert Jan|info:eu-repo/dai/nl/165576367; van Dijk, Diederik|info:eu-repo/dai/nl/241616301
2017-01-01
BACKGROUND: The pathogenesis of cognitive dysfunction in patients with CAD remains unclear. CAD is associated with brain atrophy and specific lesions. Detailed knowledge about the association of brain volume measured with MRI, and cognitive function in patients with CAD is lacking. We therefore
Directory of Open Access Journals (Sweden)
R. M. Worthington
2005-06-01
Full Text Available Thin stable atmospheric layers cause VHF radars to receive increased echo power from near zenith. Layers can be tilted from horizontal, for instance by gravity waves, and the direction of VHF "glinting" is measurable by spatial domain interferometry or many-beam Doppler beam swinging (DBS. This paper uses the Middle and Upper atmosphere (MU radar, Shigaraki, Japan as a volume-imaging radar with 64-beam DBS, to show tilting of layers and air flow in mountain waves. Tilt of aspect-sensitive echo power from horizontal is nearly parallel to air flow, as assumed in earlier measurements of mountain-wave alignment. Vertical-wind measurements are self-consistent from different beam zenith angles, despite the combined effects of aspect sensitivity and horizontal-wind gradients.
Ivanov, M. V.; Antonov, A. N.; Caballero, J. A.; Megias, G. D.; Barbaro, M. B.; de Guerra, E. Moya; Udías, J. M.
2014-01-01
Charge-current quasielastic (anti)neutrino scattering cross sections on a 12C target are analyzed using a spectral function S (p,E) that gives a scaling function in accordance with the (e ,e') scattering data. The spectral function accounts for the nucleon-nucleon (NN) correlations, it has a realistic energy dependence, and natural orbitals (NOs) from the Jastrow correlation method are used in its construction. In all calculations the standard value of the axial mass MA=1.032 GeV/c2 is used. The results are compared with those when NN correlations are not included, as in the relativistic Fermi gas model, or when harmonic-oscillator single-particle wave functions are used instead of NOs. The role of the final-state interactions (FSIs) on the theoretical spectral and scaling functions, as well as on the cross sections, is accounted for. A comparison of the results for the cases with and without FSI, as well as to results from the phenomenological scaling function obtained from the superscaling analysis, is carried out. Our calculations based on the impulse approximation underpredict the MiniBooNE data but agree with the data from the NOMAD experiment. The possible missing ingredients in the considered theoretical models are discussed.
Breakfast staple types affect brain gray matter volume and cognitive function in healthy children.
Taki, Yasuyuki; Hashizume, Hiroshi; Sassa, Yuko; Takeuchi, Hikaru; Asano, Michiko; Asano, Kohei; Kawashima, Ryuta
2010-12-08
Childhood diet is important for brain development. Furthermore, the quality of breakfast is thought to affect the cognitive functioning of well-nourished children. To analyze the relationship among breakfast staple type, gray matter volume, and intelligence quotient (IQ) in 290 healthy children, we used magnetic resonance images and applied voxel-based morphometry. We divided subjects into rice, bread, and both groups according to their breakfast staple. We showed that the rice group had a significantly larger gray matter ratio (gray matter volume percentage divided by intracranial volume) and significantly larger regional gray matter volumes of several regions, including the left superior temporal gyrus. The bread group had significantly larger regional gray and white matter volumes of several regions, including the right frontoparietal region. The perceptual organization index (POI; IQ subcomponent) of the rice group was significantly higher than that of the bread group. All analyses were adjusted for age, gender, intracranial volume, socioeconomic status, average weekly frequency of having breakfast, and number of side dishes eaten for breakfast. Although several factors may have affected the results, one possible mechanism underlying the difference between the bread and the rice groups may be the difference in the glycemic index (GI) of these two substances; foods with a low GI are associated with less blood-glucose fluctuation than are those with a high GI. Our study suggests that breakfast staple type affects brain gray and white matter volumes and cognitive function in healthy children; therefore, a diet of optimal nutrition is important for brain maturation during childhood and adolescence.
Breakfast staple types affect brain gray matter volume and cognitive function in healthy children.
Directory of Open Access Journals (Sweden)
Yasuyuki Taki
Full Text Available Childhood diet is important for brain development. Furthermore, the quality of breakfast is thought to affect the cognitive functioning of well-nourished children. To analyze the relationship among breakfast staple type, gray matter volume, and intelligence quotient (IQ in 290 healthy children, we used magnetic resonance images and applied voxel-based morphometry. We divided subjects into rice, bread, and both groups according to their breakfast staple. We showed that the rice group had a significantly larger gray matter ratio (gray matter volume percentage divided by intracranial volume and significantly larger regional gray matter volumes of several regions, including the left superior temporal gyrus. The bread group had significantly larger regional gray and white matter volumes of several regions, including the right frontoparietal region. The perceptual organization index (POI; IQ subcomponent of the rice group was significantly higher than that of the bread group. All analyses were adjusted for age, gender, intracranial volume, socioeconomic status, average weekly frequency of having breakfast, and number of side dishes eaten for breakfast. Although several factors may have affected the results, one possible mechanism underlying the difference between the bread and the rice groups may be the difference in the glycemic index (GI of these two substances; foods with a low GI are associated with less blood-glucose fluctuation than are those with a high GI. Our study suggests that breakfast staple type affects brain gray and white matter volumes and cognitive function in healthy children; therefore, a diet of optimal nutrition is important for brain maturation during childhood and adolescence.
Liu, Quanhua; Simmer, C.; Ruprecht, E.
1991-05-01
An analytical expression has been derived for the radiation source function for a thermally emitting and scattering medium within the Matrix-Operator-Method (MOM). The final formulation is equivalent to the one found by Aronson and Yarmush (1966), who applied the transfer matrix to gamma-ray and neutron penetration and to transport problems in slab geometry. For the thermal infrared case, the general analytical expression reduces to a simple formula, which depends only on the zenith angle. The formula is incorporated in the MOM together with analytical expressions of the transmission and reflection operators following Liu (1990). With the aid of these formulations, expressions are derived as parameterizations of the scattering effects of clouds in nonscattering radiative transfer models by a modification of the emissivity and transmittance of clouds. The accuracy is better than 0.5 percent in the 11.5 micron window region for clouds of arbitrary optical depths.
Desjarlais, Michael P.; Scullard, Christian R.; Benedict, Lorin X.; Whitley, Heather D.; Redmer, Ronald
2017-03-01
We compute electrical and thermal conductivities of hydrogen plasmas in the nondegenerate regime using Kohn-Sham density functional theory (DFT) and an application of the Kubo-Greenwood response formula, and demonstrate that for thermal conductivity, the mean-field treatment of the electron-electron (e-e) interaction therein is insufficient to reproduce the weak-coupling limit obtained by plasma kinetic theories. An explicit e-e scattering correction to the DFT is posited by appealing to Matthiessen's Rule and the results of our computations of conductivities with the quantum Lenard-Balescu (QLB) equation. Further motivation of our correction is provided by an argument arising from the Zubarev quantum kinetic theory approach. Significant emphasis is placed on our efforts to produce properly converged results for plasma transport using Kohn-Sham DFT, so that an accurate assessment of the importance and efficacy of our e-e scattering corrections to the thermal conductivity can be made.
Vieira, H. S.; Bezerra, V. B.
2016-10-01
We apply the confluent Heun functions to study the resonant frequencies (quasispectrum), the Hawking radiation and the scattering process of scalar waves, in a class of spacetimes, namely, the ones generated by a Kerr-Newman-Kasuya spacetime (dyon black hole) and a Reissner-Nordström black hole surrounded by a magnetic field (Ernst spacetime). In both spacetimes, the solutions for the angular and radial parts of the corresponding Klein-Gordon equations are obtained exactly, for massive and massless fields, respectively. The special cases of Kerr and Schwarzschild black holes are analyzed and the solutions obtained, as well as in the case of a Schwarzschild black hole surrounded by a magnetic field. In all these special situations, the resonant frequencies, Hawking radiation and scattering are studied.
Combining MRI with PET for partial volume correction improves image-derived input functions in mice
Energy Technology Data Exchange (ETDEWEB)
Evans, Eleanor; Buonincontri, Guido [Wolfson Brain Imaging Centre, University of Cambridge, Cambridge (United Kingdom); Izquierdo, David [Athinoula A Martinos Centre, Harvard University, Cambridge, MA (United States); Methner, Carmen [Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Hawkes, Rob C [Wolfson Brain Imaging Centre, University of Cambridge, Cambridge (United Kingdom); Ansorge, Richard E [Department of Physics, University of Cambridge, Cambridge (United Kingdom); Kreig, Thomas [Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Carpenter, T Adrian [Wolfson Brain Imaging Centre, University of Cambridge, Cambridge (United Kingdom); Sawiak, Stephen J [Wolfson Brain Imaging Centre, University of Cambridge, Cambridge (United Kingdom); Behavioural and Clinical Neurosciences Institute, University of Cambridge, Cambridge (United Kingdom)
2014-07-29
Kinetic modelling in PET requires the arterial input function (AIF), defined as the time-activity curve (TAC) in plasma. This measure is challenging to obtain in mice due to low blood volumes, resulting in a reliance on image-based methods for AIF derivation. We present a comparison of PET- and MR-based region-of-interest (ROI) analysis to obtain image-derived AIFs from the left ventricle (LV) of a mouse model. ROI-based partial volume correction (PVC) was performed to improve quantification.
Bakhlanov, S. V.; Bazlov, N. V.; Derbin, A. V.; Drachnev, I. S.; Kayunov, A. S.; Muratova, V. N.; Semenov, D. A.; Unzhakov, E. V.
2016-06-01
In this paper we present a method of scintillation detector energy calibration using the gamma-rays. The technique is based on the Compton scattering of gamma-rays in a scintillation detector and subsequent photoelectric absorption of the scattered photon in the Ge-detector. The novelty of this method is that the source of gamma rays, the germanium and scintillation detectors are immediately arranged adjacent to each other. The method presents an effective solution for the detectors consisting of a low atomic number materials, when the ratio between Compton effect and photoelectric absorption is large and the mean path of gamma-rays is comparable to the size of the detector. The technique can be used for the precision measurements of the scintillator light yield dependence on the electron energy.
Bakhlanov, S V; Derbin, A V; Drachnev, I S; Kayunov, A S; Muratova, V N; Semenov, D A; Unzhakov, E V
2016-01-01
In this paper we present a method of scintillation detector energy calibration using the gamma-rays. The technique is based on the Compton scattering of gamma-rays in a scintillation detector and subsequent photoelectric absorption of the scattered photon in the Ge-detector. The novelty of this method is that the source of gamma rays, the germanium and scintillation detectors are immediately arranged adjacent to each other. The method presents an effective solution for the detectors consisting of a low atomic number materials, when the ratio between Compton effect and photoelectric absorption is large and the mean path of gamma-rays is comparable to the size of the detector. The technique can be used for the precision measurements of the scintillator light yield dependence on the electron energy.
Energy Technology Data Exchange (ETDEWEB)
Bakhlanov, S.V. [St.Petersburg Nuclear Physics Institute, National Research Center “Kurchatov Institute”, Gatchina 188300 (Russian Federation); Bazlov, N.V. [Saint-Petersburg State University, Universitetskaja nab. 7/9, Saint-Petersburg 199034 (Russian Federation); Derbin, A.V., E-mail: derbin@pnpi.spb.ru [St.Petersburg Nuclear Physics Institute, National Research Center “Kurchatov Institute”, Gatchina 188300 (Russian Federation); Drachnev, I.S. [St.Petersburg Nuclear Physics Institute, National Research Center “Kurchatov Institute”, Gatchina 188300 (Russian Federation); GranSasso Science Institute, INFN, L' Aquila (AQ) I-67100 (Italy); Kayunov, A.S.; Muratova, V.N.; Semenov, D.A.; Unzhakov, E.V. [St.Petersburg Nuclear Physics Institute, National Research Center “Kurchatov Institute”, Gatchina 188300 (Russian Federation)
2016-06-11
In this paper we present a method of scintillation detector energy calibration using the gamma-rays. The technique is based on the Compton scattering of gamma-rays in a scintillation detector and subsequent photoelectric absorption of the scattered photon in the Ge-detector. The novelty of this method is that the source of gamma rays, the germanium and scintillation detectors are immediately arranged adjacent to each other. The method presents an effective solution for the detectors consisting of a low atomic number materials, when the ratio between Compton effect and photoelectric absorption is large and the mean path of gamma-rays is comparable to the size of the detector. The technique can be used for the precision measurements of the scintillator light yield dependence on the electron energy.
Analytic expression for the proton structure function in deep inelastic scattering
Institute of Scientific and Technical Information of China (English)
XIANG Wen-Chang; ZHOU Dai-Cui; WAN Ren-Zhuo; YUAN Xian-Bao
2009-01-01
The analytic expression of proton in deep inelastic scattering is studied by using the color glass condensate model and the dipole picture. We get a better description of the HERA DIS data than the CBW model which was inspired by the Glauber model. We find that our model satisfies the unitarity limit and Froissart Bound which refers to an energy dependence of the total cross-section rising no more rapidly than ln2s.
Hutchinson, Kirk R.; Guggilam, Anuradha; Cismowski, Mary J.; Galantowicz, Maarten L.; West, Thomas A.; Stewart, James A.; Zhang, Xiaojin; Lord, Kevin C.
2011-01-01
Current surgical management of volume overload-induced heart failure (HF) leads to variable recovery of left ventricular (LV) function despite a return of LV geometry. The mechanisms that prevent restoration of function are unknown but may be related to the timing of intervention and the degree of LV contractile impairment. This study determined whether reduction of aortocaval fistula (ACF)-induced LV volume overload during the compensatory stage of HF results in beneficial LV structural remodeling and restoration of pump function. Rats were subjected to ACF for 4 wk; a subset then received a load-reversal procedure by closing the shunt using a custom-made stent graft approach. Echocardiography or in vivo pressure-volume analysis was used to assess LV morphology and function in sham rats; rats subjected to 4-, 8-, or 15-wk ACF; and rats subjected to 4-wk ACF followed by 4- or 11-wk reversal. Structural and functional changes were correlated to LV collagen content, extracellular matrix (ECM) proteins, and hypertrophic markers. ACF-induced volume overload led to progressive LV chamber dilation and contractile dysfunction. Rats subjected to short-term reversal (4-wk ACF + 4-wk reversal) exhibited improved chamber dimensions (LV diastolic dimension) and LV compliance that were associated with ECM remodeling and normalization of atrial and brain natriuretic peptides. Load-independent parameters indicated LV systolic (preload recruitable stroke work, Ees) and diastolic dysfunction (tau, arterial elastance). These changes were associated with an altered α/β-myosin heavy chain ratio. However, these changes were normalized to sham levels in long-term reversal rats (4-wk ACF + 11-wk reversal). Acute hemodynamic changes following ACF reversal improve LV geometry, but LV dysfunction persists. Gradual restoration of function was related to normalization of eccentric hypertrophy, LV wall stress, and ECM remodeling. These results suggest that mild to moderate LV systolic
Directory of Open Access Journals (Sweden)
Xiaolu Tang
Full Text Available Chinese fir (Cunninghamia lanceolata [Lamb.] Hook is one of the most important plantation tree species in China with good timber quality and fast growth. It covers an area of 8.54 million hectare, which corresponds to 21% of the total plantation area and 32% of total plantation volume in China. With the increasing market demand, an accurate estimation and prediction of merchantable volume at tree- and stand-level is becoming important for plantation owners. Although there are many studies on the total tree volume estimation from allometric models, these allometric models cannot predict tree- and stand-level merchantable volume at any merchantable height, and the stand-level merchantable volume model was not seen yet in Chinese fir plantations. This study aimed to develop (1 a compatible taper function for tree-level merchantable volume estimation, and (2 a stand-level merchantable volume model for Chinese fir plantations. This "taper function system" consisted in a taper function, a merchantable volume equation and a total tree volume equation. 46 Chinese fir trees were felled to develop the taper function in Shitai County, Anhui province, China. A second-order continuous autoregressive error structure corrected the inherent serial autocorrelation of different observations in one tree. The taper function and volume equations were fitted simultaneously after autocorrelation correction. The compatible taper function fitted well to our data and had very good performances in diameter and total tree volume prediction. The stand-level merchantable volume equation based on the ratio approach was developed using basal area, dominant height, quadratic mean diameter and top diameter (ranging from 0 to 30 cm as independent variables. At last, a total stand-level volume table using stand basal area and dominant height as variables was proposed for local forest managers to simplify the stand volume estimation.
Energy Technology Data Exchange (ETDEWEB)
Yin, Jie [Key Laboratory of Modern Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Department of Automation, Nanjing Polytechnic Institute, 210048 Nanjing (China); Tao, Chao, E-mail: taochao@nju.edu.cn; Cai, Peng; Liu, Xiaojun, E-mail: liuxiaojun@nju.edu.cn [Key Laboratory of Modern Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)
2015-06-08
Acoustically inhomogeneous mediums with multiple scattering are often the nightmare of photoacoustic tomography. In order to break this limitation, a photoacoustic tomography scheme combining ultrasound interferometry and time reversal is proposed to achieve images in acoustically scattering medium. An ultrasound interferometry is developed to determine the unknown Green's function of strong scattering tissue. Using the determined Greens' function, a time-reversal process is carried out to restore images behind an acoustically inhomogeneous layer from the scattering photoacoustic signals. This method effectively decreases the false contrast, noise, and position deviation of images induced by the multiple scattering. Phantom experiment is carried out to validate the method. Therefore, the proposed method could have potential value in extending the biomedical applications of photoacoustic tomography in acoustically inhomogeneous tissue.
Directory of Open Access Journals (Sweden)
Pieper Jörg
2015-01-01
Full Text Available This short review summarizes our current knowledge about the functional relevance of protein dynamics in photosynthetic reaction centers. In the case of Photosystem II membrane fragments, elastic and quasielastic neutron scattering experiments reveal a dynamical transition at about 240 K corresponding to the activation of picosecond molecular motions. Likewise, a “freezing” of molecular dynamics is observed upon dehydration. Intriguingly, these effects correlate with the pronounced temperature- and hydration-dependence of specific electron transfer steps in Photosystem II indicating that molecular dynamics is an indispensable prerequisite for its function. Thus, electron transfer in Photosystem II appears to be a prototypical example for a dynamics-function correlation. Finally, the laser-neutron pump-probe technique is shown to permit in-situ monitoring of molecular dynamics in specific functional states of a protein in real time.
Davies, J; Moch, S; Vermaseren, J A M
2016-01-01
We have calculated the coefficient functions for the structure functions F_2, F_L and F_3 in nu-nubar charged-current deep-inelastic scattering (DIS) at the third order in the strong coupling alpha_s, thus completing the description of unpolarized inclusive W^(+-) exchange DIS to this order of massless perturbative QCD. In this brief note, our new results are presented in terms of compact approximate expressions that are sufficiently accurate for phenomenological analyses. For the benefit of such analyses we also collect, in a unified notation, the corresponding lower-order contributions and the flavour non-singlet coefficient functions for nu+nubar charged-current DIS. The behaviour of all six third-order coefficient functions at small Bjorken-x is briefly discussed.
Effect of low tidal volume ventilation on lung function and inflammation in mice
Directory of Open Access Journals (Sweden)
Goldmann Torsten
2010-04-01
Full Text Available Abstract Background A large number of studies have investigated the effects of high tidal volume ventilation in mouse models. In contrast data on very short term effects of low tidal volume ventilation are sparse. Therefore we investigated the functional and structural effects of low tidal volume ventilation in mice. Methods 38 Male C57/Bl6 mice were ventilated with different tidal volumes (Vt 5, 7, and 10 ml/kg without or with application of PEEP (2 cm H2O. Four spontaneously breathing animals served as controls. Oxygen saturation and pulse rate were monitored. Lung function was measured every 5 min for at least 30 min. Afterwards lungs were removed and histological sections were stained for measurement of infiltration with polymorphonuclear leukocytes (PMN. Moreover, mRNA expression of macrophage inflammatory protein (MIP-2 and tumor necrosis factor (TNFα in the lungs was quantified using real time PCR. Results Oxygen saturation did not change significantly over time of ventilation in all groups (P > 0.05. Pulse rate dropped in all groups without PEEP during mechanical ventilation. In contrast, in the groups with PEEP pulse rate increased over time. These effects were not statistically significant (P > 0.05. Tissue damping (G and tissue elastance (H were significantly increased in all groups after 30 min of ventilation (P 0.05. Mechanical ventilation significantly increased infiltration of the lungs with PMN (P Conclusions Our data show that very short term mechanical ventilation with lower tidal volumes than 10 ml/kg did not reduce inflammation additionally. Formation of atelectasis and inadequate oxygenation with very low tidal volumes may be important factors. Application of PEEP attenuated inflammation.
Arun, K. R.; Kraft, M.; Lukáčová-Medvid'ová, M.; Prasad, Phoolan
2009-02-01
We present a generalization of the finite volume evolution Galerkin scheme [M. Lukáčová-Medvid'ová, J. Saibertov'a, G. Warnecke, Finite volume evolution Galerkin methods for nonlinear hyperbolic systems, J. Comp. Phys. (2002) 183 533- 562; M. Lukáčová-Medvid'ová, K.W. Morton, G. Warnecke, Finite volume evolution Galerkin (FVEG) methods for hyperbolic problems, SIAM J. Sci. Comput. (2004) 26 1-30] for hyperbolic systems with spatially varying flux functions. Our goal is to develop a genuinely multi-dimensional numerical scheme for wave propagation problems in a heterogeneous media. We illustrate our methodology for acoustic waves in a heterogeneous medium but the results can be generalized to more complex systems. The finite volume evolution Galerkin (FVEG) method is a predictor-corrector method combining the finite volume corrector step with the evolutionary predictor step. In order to evolve fluxes along the cell interfaces we use multi-dimensional approximate evolution operator. The latter is constructed using the theory of bicharacteristics under the assumption of spatially dependent wave speeds. To approximate heterogeneous medium a staggered grid approach is used. Several numerical experiments for wave propagation with continuous as well as discontinuous wave speeds confirm the robustness and reliability of the new FVEG scheme.
Magnetotelluric Detection Thresholds as a Function of Leakage Plume Depth, TDS and Volume
Energy Technology Data Exchange (ETDEWEB)
Yang, X. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Buscheck, T. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mansoor, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Carroll, S. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2017-04-21
We conducted a synthetic magnetotelluric (MT) data analysis to establish a set of specific thresholds of plume depth, TDS concentration and volume for detection of brine and CO_{2} leakage from legacy wells into shallow aquifers in support of Strategic Monitoring Subtask 4.1 of the US DOE National Risk Assessment Partnership (NRAP Phase II), which is to develop geophysical forward modeling tools. 900 synthetic MT data sets span 9 plume depths, 10 TDS concentrations and 10 plume volumes. The monitoring protocol consisted of 10 MT stations in a 2×5 grid laid out along the flow direction. We model the MT response in the audio frequency range of 1 Hz to 10 kHz with a 50 Ωm baseline resistivity and the maximum depth up to 2000 m. Scatter plots show the MT detection thresholds for a trio of plume depth, TDS concentration and volume. Plumes with a large volume and high TDS located at a shallow depth produce a strong MT signal. We demonstrate that the MT method with surface based sensors can detect a brine and CO_{2} plume so long as the plume depth, TDS concentration and volume are above the thresholds. However, it is unlikely to detect a plume at a depth larger than 1000 m with the change of TDS concentration smaller than 10%. Simulated aquifer impact data based on the Kimberlina site provides a more realistic view of the leakage plume distribution than rectangular synthetic plumes in this sensitivity study, and it will be used to estimate MT responses over simulated brine and CO_{2} plumes and to evaluate the leakage detectability. Integration of the simulated aquifer impact data and the MT method into the NRAP DREAM tool may provide an optimized MT survey configuration for MT data collection. This study presents a viable approach for sensitivity study of geophysical monitoring methods for leakage detection. The results come in handy for rapid assessment of leakage detectability.
Melchiorre, Karen; Sharma, Rajan; Khalil, Asma; Thilaganathan, Baskaran
2016-04-01
The aim of this study was to investigate cardiac functional status in pregnancy using a comprehensive approach taking into account the simultaneous changes in loading and geometry, as well as maternal age and anthropometric indices. This was a prospective cross-sectional study of 559 nulliparous pregnant women assessed at 4 time points during pregnancy and at 1 year postpartum. All women underwent conventional echocardiography and tissue Doppler velocities and strain rate analysis at multiple cardiac sites. Mean arterial pressure and total vascular resistance index significantly decreased (both Ppregnancy and increased thereafter. Stroke volume index and cardiac index showed the opposite trend compared with mean arterial pressure and total vascular resistance index (both Ppregnancy, significant chamber diastolic dysfunction and impaired myocardial relaxation was evident in 17.9% and 28.4% of women, respectively, whereas myocardial contractility was preserved. There was full recovery of cardiac function at 1 year postpartum. Cardiovascular changes during pregnancy are thought to represent a physiological adaptation to volume overload. The findings of a drop in stroke volume index, impaired myocardial relaxation with diastolic dysfunction, and a tendency toward eccentric remodeling in a significant proportion of cases at term are suggestive of cardiovascular maladaptation to the volume-overloaded state in some apparently normal pregnancies. These unexpected cardiovascular findings have important implications for the management of both normal and pathological pregnancy states.
[Volume and function of the right ventricle before and after intraluminal pulmonary valvuloplasty].
Rangel-Abundis, A; López, H; Badui, E; Martínez-Becerril, A
1991-01-01
With the purpose of studying the right ventricular infundibulum response to the obstruction of the pulmonary blood flow, the authors inform the results of the right ventricular volumes, and function changes before and after pulmonary intraluminal valvuloplasty performed in six adult patients with congenital stenosis of the pulmonary valve. After the valvuloplasty, all right ventricular volumes increased but only slightly, except for the end systolic volume at the right infundibulum, which decreased after valvuloplasty (for alpha = 0.10, p less than 0.10). The ejection fraction of this infundibulum increased after valvuloplasty (for alpha = 0.05 p less than 0.03), while the ejection fraction of the inflow chamber remained unaltered. In the same way decreased the work and power of the inflow tract of the right ventricle, regardless the decreased in the ventricular overload post-valvuloplasty; however, the ratio work vs. end diastolic volume of the right ventricle decreased (for alpha = 0.05, p less than 0.03). The authors discuss these results in relation with the changes produced by the obstruction, acute or chronic, of the pulmonary blood flow on the infundibular wall tension and contractility, whose structure and behavior allow to propose that the function of the infundibulum by means of contraction protects the pulmonary vasculature, against right ventricle hypertension.
Evaluation of right ventricular volume and function by 2D and 3D echocardiography compared to MRI
DEFF Research Database (Denmark)
Kjaergaard, Jesper; Petersen, Claus Leth; Kjaer, Andreas;
2005-01-01
AIMS: Radionuclide techniques, and recently MRI, have been used for clinical evaluation of right ventricular (RV) volumes function (RVEF) and volumes; but with the introduction of 3D echocardiography, new echocardiographic possibilities for RV evaluation independent of geometrical assumptions have...... emerged. This study compared classic and new echocardiographic and radionuclide estimates, including gated blood pool single-photon emission computed tomography (SPECT) of RV size and function to RV volumes, and ejection fraction (RVEF) measured by magnetic resonance imaging (MRI). METHODS AND RESULTS...
Analysis of Point-Spread Function for Imaging Moving Targets from Scattered Waves
2008-12-01
Ψscatt (x) = Gk (x ’,x)ρ(x ’)D∫∫∫ Ψ inc (x ’) + Ψscatt (x ’)( )d 3x ’ (3.3) This is a Lippmann- Schwinger equation. It can be observed that the...conditions for a known target. It is appropriate to make several additional observations with respect to the Lippmann- Schwinger equation: (1) There...inverse scattering problem – i.e. that of determining ρ given Ψ inc and Ψscatt , can also be approached using the Lippmann- Schwinger equation as
Ben, F. G.; Machado, M. V. T.; Sauter, W. K.
2017-09-01
We provide a universal expression of cross sections for the exclusive vector meson production and deeply virtual Compton scattering (DVCS) in photon-proton and photon-nucleus interactions based on the geometric scaling phenomenon. The theoretical parametrization based on the scaling property depends only on the single variable τA=Q2/Qsat2, where the saturation scale, Qsat, drives the energy dependence and the corresponding nuclear effects. This phenomenological result describes all available data from DESY-HERA for ρ ,ϕ ,J /ψ production and DVCS measurements. A discussion is also carried out on the size of nuclear shadowing corrections on photon-nucleus interaction.
Bloomfield, Philip E
2005-05-01
The pulse-echo impulse-response format in the Field II formalism is generalized to separately located transmitter and receiver. To first order in sound velocity and density perturbations, identical results for the scattering-object function are obtained for the Morse-Ingard and the Chernov formulation in both the temporal and frequency domains: f(s)=-[2Delta(c/c)+(Delta(rho/rho))(1-cos(theta))] where for ultrasonic pulse-echo or transmission modality, cos(theta) approximately -1 or +1, respectively.
DEFF Research Database (Denmark)
Shi, Qing; Voss, Johannes; Jacobsen, H.S.
2007-01-01
we study hydrogen dynamics in undoped and TiCl3-doped samples of NaAlH4 and Na3AlH6 using a combination of density functional theory calculations and quasielastic neutron scattering. Hydrogen dynamics is found to be limited and mediated by hydrogen vacancies in both alanate phases, requiring......Understanding the catalytic role of titanium-based additives on the reversible hydrogenation of complex metal hydrides is an essential step towards developing hydrogen storage materials for the transport sector. Improved bulk diffusion of hydrogen is one of the proposed catalytic effects, and here...
DEFF Research Database (Denmark)
Voss, Johannes; Shi, Qing; Jacobsen, Hjalte Sylvest
2007-01-01
alanate with TiCl3, and here we study hydrogen dynamics in doped and undoped Na3AlH6 using a combination of density functional theory calculations and quasielastic neutron scattering. The hydrogen dynamics is found to be vacancy mediated and dominated by localized jump events, whereas long-range bulk......Understanding the elusive catalytic role of titanium-based additives on the reversible hydrogenation of complex hydrides is an essential step toward developing hydrogen storage materials for the transport sector. Improved bulk diffusion of hydrogen is one of the proposed effects of doping sodium...
Energy Technology Data Exchange (ETDEWEB)
Fontana, A [Dipartimento di Fisica, Universita di Trento, I-38050 Povo Trento (Italy); Rossi, F [Dipartimento di Fisica, Universita di Trento, I-38050 Povo Trento (Italy); Viliani, G [Dipartimento di Fisica, Universita di Trento, I-38050 Povo Trento (Italy); Caponi, S [Dipartimento di Fisica, Universita di Trento, I-38050 Povo Trento (Italy); Fabiani, E [Universite Joseph Fourier c/o Institut de Biologie Structurale and CRG-IN13 at Institut Laue-Langevin (ILL), BP 156, 38043 Grenoble Cedex 9 (France); Baldi, G [CRS SOFT CNR-INFM, c/o Universita di Roma ' La Sapienza' , I-00185, Rome (Italy); Ruocco, G [CRS SOFT CNR-INFM, c/o Universita di Roma ' La Sapienza' , I-00185, Rome (Italy); Dal Maschio, R [Dipartimento di Ingegneria dei Materiali e delle Tecnologie Industriali, Universita di Trento, I-38050 Mesiano Trento (Italy)
2007-05-23
We report new inelastic Raman and neutron scattering spectra for glasses with different degrees of fragility, v-SiO{sub 2}, v-GeO{sub 2} (AgI){sub 0.5}(Ag{sub 2}O-B{sub 2}O{sub 3}){sub 0.5} (AgI){sub x}(AgPO{sub 3}){sub 1-x}. The data are compared for each sample to obtain the Raman coupling function C({omega}). The study indicates a general linear behaviour of C({omega}) near the boson peak maximum, and evidences a correlation between vibrational and relaxational properties, confirming the results of recent publications.
Ahn, Chi Young; Jeon, Kiwan; Park, Won-Kwang
2015-06-01
This study analyzes the well-known MUltiple SIgnal Classification (MUSIC) algorithm to identify unknown support of thin penetrable electromagnetic inhomogeneity from scattered field data collected within the so-called multi-static response matrix in limited-view inverse scattering problems. The mathematical theories of MUSIC are partially discovered, e.g., in the full-view problem, for an unknown target of dielectric contrast or a perfectly conducting crack with the Dirichlet boundary condition (Transverse Magnetic-TM polarization) and so on. Hence, we perform further research to analyze the MUSIC-type imaging functional and to certify some well-known but theoretically unexplained phenomena. For this purpose, we establish a relationship between the MUSIC imaging functional and an infinite series of Bessel functions of integer order of the first kind. This relationship is based on the rigorous asymptotic expansion formula in the existence of a thin inhomogeneity with a smooth supporting curve. Various results of numerical simulation are presented in order to support the identified structure of MUSIC. Although a priori information of the target is needed, we suggest a least condition of range of incident and observation directions to apply MUSIC in the limited-view problem.
Steady-state probability density function in wave turbulence under large volume limit
Institute of Scientific and Technical Information of China (English)
Yeontaek Choia; Sang Gyu Job
2011-01-01
We investigate the possibility for two-mode probability density function (PDF) to have a non-zero flux steady state solution. We take the large volume limit so that the space of modes becomes continuous. It is shown that in this limit all the steady-state two- or higher-mode PDFs are the product of one-mode PDFs. The flux of this steady-state solution turns out to be zero for any finite mode PDF.
1988-09-16
Interes Publico, Av. Espinoza No. 843, Apdo. Postal 2732, Ensenada, Baja California, Mexico RIGOROUS SOLUTION OF PROBLEMS OF SCATTERING BY LARGE SIZE...CONDITIONS USED TO STUDY LIGHT SCATTERING FROM METALLIC ROUGH SURFACES Ricardo A. Depine. Universidad de Buenos Aires The scattering of a plane wave by
Trampert, Patrick; Vogelgesang, Jonas; Schorr, Christian; Maisl, Michael; Bogachev, Sviatoslav; Marniok, Nico; Louis, Alfred; Dahmen, Tim; Slusallek, Philipp
2017-03-21
Laminography is a tomographic technique that allows three-dimensional imaging of flat and elongated objects that stretch beyond the extent of a reconstruction volume. Laminography images can be reconstructed using iterative algorithms based on the Kaczmarz method. This study aims to develop and demonstrate a new reconstruction algorithm that may provide superior image reconstruction quality for this challenged imaging application. The images are initially represented using the coefficients over basis functions, which are typically piecewise constant functions (voxels). By replacing voxels with spherically symmetric volume elements (blobs) based on the generalized Kaiser-Bessel window functions, the images are reconstructed using this new adapted version of the algebraic image reconstruction technique. Band-limiting properties of blob functions are beneficial particular in the case of noisy projections and with only a limited number of available projections. Study showed that using blob basis functions improved full-width-at-half-maximum resolution from 10.2±1.0 to 9.9±0.9 (p functions, especially if noisy data is expected.
Electronic Raman scattering as a function of doping in high-{Tc} superconductors
Energy Technology Data Exchange (ETDEWEB)
Kendziora, C. [Naval Research Lab., Washington, DC (United States); Kelley, R.J.; Onellion, M. [Univ. of Wisconsin, Madison, WI (United States). Physics Dept.
1996-12-31
The authors report the results of Raman scattering from the electronic continuum in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi 2212) and Ti{sub 2}Ba{sub 2}CuO{sub 6+{delta}} (Tl 2201) high temperature superconductors with variations in the oxygen content, {delta}. Below {Tc}, a peak develops in the Raman continuum associated with the opening of a superconducting gap, {Delta}(k). By selecting the polarizations of incident and scattered light, they are sensitive to possible anisotropy of the gap within the a-b plane. Near optimal doping, both materials show gap anisotropy, with 2{Delta}/k{sub B}{Tc} values of 7.2 (B{sub 1g}) vs. 5.8 (A{sub 1g}) in Tl 2202 and 8.5 (B{sub 1g}) vs. 6.2 (A{sub 1g}) in Bi 2212. In contrast, both show an isotropic gap at much lower energy shifts when the carrier concentration is raised: 2{Delta}/k{sub B}{Tc} = 3.9 (5.5) for Tl 2201 (Bi 2212) with {Tc} = 37K (57K). The authors compare the observed spectra with calculations based on order parameters with d-wave as well as isotropic s-wave symmetry and conclude that raising the doping level reduces the gap anisotropy to near zero.
Energy Technology Data Exchange (ETDEWEB)
Kaptari, Leonya P. [University of Perugia (Italy); INFN-Perugia (Italy); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Joint Inst. for Nuclear Research, Dubna (Russia); Del Dotto, Alessio [University of Rome, Rome (Italy); INFN-Roma (Italy); Pace, Emanuele [University of Rome (Italy); INFN-Tor Vergata (Italy); Salme, Giovanni [INFN-Roma (Italy); Scopetta, Sergio [University of Perugia (Italy); INFN-Perugia (Italy)
2014-03-01
The spin dependent spectral function, relevant to describe polarized electron scattering off polarized {sup 3}He, is studied, within the Plane Wave Impulse Approximation and taking into account final state interaction effects (FSI). In particular, the case of semi-inclusive deep inelastic scattering (SiDIS) is considered, evaluating the FSI of the hadronizing quark with the nuclear remnants. It is shown that particular kinematical regions can be selected to minimize the latter effects, so that parton distributions in the neutron can be accessed. On the other side, in the regions where FSI dominates, the considered reactions can elucidate the mechanism of hadronization of quarks during the propagation in the nuclear medium. It is shown that the obtained spin dependent spectral function can be directly applied to investigate the SiDIS reaction e-vector + {sup 3}He-vector to h+X, where the hadron h originates from the current fragmentation. Experiments of this type are being performed at JLab to extract neutron transverse momentum dependent parton distributions. As a case study, a different SiDIS process, with detection of slow (A-1) systems in the final state, is considered in more details, in order to establish when nuclear structure effects and FSI can be distinguished from elementary reactions on quasi-free nucleons. It is argued that, by a proper choice of kinematics, the origin of nuclear effects in polarized DIS phenomena and the details of the interaction between the hadronizing quark and the nuclear medium can be investigated at a level which is not reachable in inclusive deep inelastic scattering.
Directory of Open Access Journals (Sweden)
Lorenti Alicia
2010-10-01
Full Text Available Abstract Background Cell scattering is a physiological process executed by stem and progenitor cells during embryonic liver development and postnatal organ regeneration. Here, we investigated the genomic events occurring during this process induced by functional blockade of α5β1 integrin in liver progenitor cells. Results Cells treated with a specific antibody against α5β1 integrin exhibited cell spreading and scattering, over-expression of liver stem/progenitor cell markers and activation of the ERK1/2 and p38 MAPKs signaling cascades, in a similar manner to the process triggered by HGF/SF1 stimulation. Gene expression profiling revealed marked transcriptional changes of genes involved in cell adhesion and migration, as well as genes encoding chromatin remodeling factors. These responses were accompanied by conspicuous spatial reorganization of centromeres, while integrin genes conserved their spatial positioning in the interphase nucleus. Conclusion Collectively, our results demonstrate that α5β1 integrin functional blockade induces cell migration of hepatic progenitor cells, and that this involves a dramatic remodeling of the nuclear landscape.
DEFF Research Database (Denmark)
Xu, Hui; Birgisson, Steinar; Sommer, Sanna
Metal-Organic Frameworks (MOFs) is constructed by metal-oxide nodes and organic ligands. The formation of different structures of metal-oxide nodes (also called secondary building units, SBU) is crucial for MOF final structures, because the connectivity of SBU greatly influence the final MOF...... structure. At the same time, there is an ongoing debate on whether the SBU is present prior, or during MOF crystallization in MOF chemistry. However, little is known about MOFs formation mechanism. Currently techniques to study the in situ MOF formation process mainly focused on after......-crystallization process, for example in situ XRD and SAXS/WAXS study on MOF formation. However, the pre-crystallization process in the early stage of MOF formation is still unexplored. In this project, total scattering and PDF study will be carried out to explore the MOF formation process in early stage. This includes...
Winge, David O.; Franckie, Martin; Verozzi, Claudio; Wacker, Andreas; Pereira, Mauro F.
2016-10-01
Regardless of all the success of Mid Infrared Quantum Cascade Lasers (QCLs), they still do not operate at room temperature in the THz range. The main temperature degrading mechanism for THz QCLs is not known in time of writing this abstract and it is still a topic of debate by the community [S. Khanal et al, J. Opt. 16 094001, 2014]. This is a challenge to theory and it is crucial to treat all possible scattering channels with the same mathematical footing. A summary of different methods for simulating these structures is found in [C. Jirauschek et al, Appl. Phys. Rev. 1 011307, 2014]. In this work we include and study the effects of electron-electron scattering via the Single Plasmon Pole Approximation (SPPA). In this approximation we capture both the static limit as well as dynamic effects. This gives an energy dependent (non-local in time) interaction beyond the Hartree-Fock approximation. This has been studied in a similar model with promising results [T. Schmielau and M.F. Pereira, Appl. Phys. Lett. 95 231111, 2009], and with this work we want to adapt the idea into the model described in Ref. [A. Wacker et a, IEEE Journal of Sel. Top. in Quantum Electron.,19 1200611, 2013]. We start by summarizing the theory underlying the SPPA and we show how it is implemented in the context of our formalism, by showing good agreement with the results for a four well quantum cascade laser [M. Amanti et al, New J. Phys. 11 125022, 2009].
DEFF Research Database (Denmark)
Kühl, Jørgen Tobias; Kofoed, Klaus F; Møller, Jacob E
2010-01-01
and mechanical function with Multi Slice Computed Tomography (MSCT) in patients with ischemic heart disease. Furthermore, the LA and left ventricular (LV) function was evaluated in relation to signs of clinical heart failure. METHODS AND RESULTS: MSCT was performed in 40 patients with sinus rhythm and ischemic......Left atrial (LA) maximal volume contains prognostic information in patients with heart failure and acute myocardial infarction. However, only few studies have investigated the detailed mechanical function of the LA in these patients. We assessed the feasibility of evaluating LA volume...... heart disease. We enrolled 20 patients with reduced LV ejection fraction (LVEF=45%) and 20 with preserved LVEF (>45%). LA volumes, reservoir, channel and pump function were measured. Interobserver variation for LA volume measures was 1.5% (SD: 6.6%). In patients with reduced LVEF, LA volumes were larger...
Scattering by interstellar graphite dust analog
Ahmed, Gazi A.; Gogoi, Ankur
2014-10-01
The analysis of optical scattering data of interstellar carbonaceous graphite dust analog at 543.5 nm, 594.5 nm and 632.8 nm laser wavelengths by using an original laboratory light scattering setup is presented. The setup primarily consisted of a laser source, optical units, aerosol sprayer, data acquisition system and associated instrumentation. The instrument measured scattered light signals from 10° to 170° in steps of 1°. The results of the measurements of the volume scattering function β(θ) and degree of linear polarization P(θ) of the carbonaceous graphite dust particles that were sprayed in front of the laser beam by using an aerosol sprayer were subsequently compared with theoretically generated Mie plots with estimated parameters.
Ashoor, Mansour; Asgari, Afrouz; Khorshidi, Abdollah; Rezaei, Ali
2015-01-01
Purpose: Estimation of Compton attenuation and the photoelectric absorption coefficients were explored at various depths. Methods: A new method was proposed for estimating the depth based on the convolution of two exponential functions, namely convolution of scattering and primary functions (CSPF), which the convolved result will conform to the photopeak region of energy spectrum with the variable energy-window widths (EWWs) and a theory on the scattering cross-section. The triple energy-windows (TEW) and extended triple energy-windows scatter correction (ETEW) methods were used to estimate the scattered and primary photons according to the energy spectra at various depths due to a better performance than the other methods in nuclear medicine. For this purpose, the energy spectra were employed, and a distinct phantom along with a technetium-99 m source was simulated by Monte Carlo method. Results: The simulated results indicate that the EWW, used to calculate the scattered and primary counts in terms of the integral operators on the functions, was proportional to the depth as an exponential function. The depth will be calculated by the combination of either TEW or ETEW and proposed method resulting in the distinct energy-window. The EWWs for primary photons were in good agreement with those of scattered photons at the same as depths. The average errors between these windows for both methods TEW, and ETEW were 7.25% and 6.03% at different depths, respectively. The EWW value for functions of scattered and primary photons was reduced by increasing the depth in the CSPF method. Conclusions: This coefficient may be an index for the scattering cross-section. PMID:26170567
Volume reflection of ultrarelativistic particles in single crystals
Directory of Open Access Journals (Sweden)
V. A. Maisheev
2007-08-01
Full Text Available An analytical description of volume reflection of charged ultrarelativistic particles in bent single crystals is considered. The relation describing the angle of volume reflection as a function of the transversal energy is obtained. Different angle distributions of the scattered protons in single crystals are found. Results of calculations for 400 GeV protons scattered by the silicon single crystal are presented.
Geometrical volume effects in the computation of the slope of the Isgur-Wise function
Energy Technology Data Exchange (ETDEWEB)
Lellouch, L. [Southampton Univ. (United Kingdom). Dept. of Physics; Nieves, J. [Southampton Univ. (United Kingdom). Dept. of Physics; Sachrajda, C.T. [Southampton Univ. (United Kingdom). Dept. of Physics; Stella, N. [Southampton Univ. (United Kingdom). Dept. of Physics; Wittig, H. [Southampton Univ. (United Kingdom). Dept. of Physics; Martinelli, G. [Dipartimento di Fisica, Universita di Roma `La Sapienza`, 00185 Rome (Italy); Richards, D.G. [Department of Physics, The University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom); UKQCD Collaboration
1995-06-19
We use a method recently suggested for evaluating the slope of the Isgur-Wise function, at the zero-recoil point, on the lattice. The computations are performed in the quenched approximation to lattice QCD, on a 24{sup 3} x48 lattice at {beta}=6.2, using an O(a)-improved action for the fermions. We have found unexpectedly large finite-volume effects in such a calculation. These volume corrections turned out to be purely geometrical and independent of the dynamics of the system. After the study of these effects on a smaller volume and for different quark masses, we give approximate expressions that account for them. Using these approximations we find {xi}{sup `}(1)=-1.7{sup +2}{sub -2} and {xi}{sup `}(1)=-1.4{sup +2}{sub -1} for the slope of the Isgur-Wise function, for two mesons composed of a heavy quark slightly heavier and lighter, respectively, than the charm quark, and in both cases, a light antiquark whose mass is about that of the strange quark. ((orig.)).
Lung function, transfusion, pulmonary capillary blood volume and sickle cell disease.
Lunt, Alan; McGhee, Emily; Robinson, Polly; Rees, David; Height, Susan; Greenough, Anne
2016-02-01
Lung function abnormalities occur in children with sickle cell disease (SCD) and may be associated with elevated pulmonary blood volume. To investigate that association, we determined whether blood transfusion in SCD children acutely increased pulmonary capillary blood volume (PCBV) and increased respiratory system resistance (Rrs5). Measurements of Rrs5 and spirometry were made before and after blood transfusion in 18 children, median age 14.2 (6.6-18.5) years. Diffusing capacity for carbon monoxide and nitric oxide were assessed to calculate the PCBV. Post transfusion, the median Rrs5 had increased from 127.4 to 141.3% predicted (pvolume from 39.7 to 64.1 ml/m2 (pvolume in one second (p=0.0056) and vital capacity (p=0.0008) decreased. The increase in Rrs5 correlated with the increase in PCBV (r=0.50, p=0.0493). Increased pulmonary capillary blood volume may at least partially explain the lung function abnormalities in SCD children.
Bruno, Oscar P
2016-01-01
This paper presents a full-spectrum Green function methodology (which is valid, in particular, at and around Wood-anomaly frequencies) for evaluation of scattering by periodic arrays of cylinders of arbitrary cross section-with application to wire gratings, particle arrays and reflectarrays and, indeed, general arrays of conducting or dielectric bounded obstacles under both TE and TM polarized illumination. The proposed method, which, for definiteness is demonstrated here for arrays of perfectly conducting particles under TE polarization, is based on use of the shifted Green-function method introduced in the recent contribution (Bruno and Delourme, Jour. Computat. Phys. pp. 262--290 (2014)). A certain infinite term arises at Wood anomalies for the cylinder-array problems considered here that is not present in the previous rough-surface case. As shown in this paper, these infinite terms can be treated via an application of ideas related to the Woodbury-Sherman-Morrison formulae. The resulting approach, which i...
Institute of Scientific and Technical Information of China (English)
LI Lin; ZHOU Zhen-gong; WANG Biao
2006-01-01
The scattering problem of anti-plane shear waves in a functionally graded material strip with an off-center crack is investigated by use of Schmidt method. The crack is vertically to the edge of the strip. By using the Fourier transform, the problem can be solved with the help of a pair of dual integral equations that the unknown variable is the jump of the displacement across the crack surfaces. To solve the dual integral equations, the jump of the displacement across the crack surfaces was expanded in a series of Jacobi polynomials. Numerical examples were provided to show the effects of the parameter describing the functionally graded materials, the position of the crack and the frequency of the incident waves upon the stress intensity factors of the crack.
Function of cGMP-dependent protein kinase II in volume load-induced diuresis.
Schramm, Andrea; Schinner, Elisabeth; Huettner, Johannes P; Kees, Frieder; Tauber, Philipp; Hofmann, Franz; Schlossmann, Jens
2014-10-01
Atrial natriuretic peptide (ANP)/cGMPs cause diuresis and natriuresis. Their downstream effectors beyond cGMP remain unclear. To elucidate a probable function of cGMP-dependent protein kinase II (cGKII), we investigated renal parameters in different conditions (basal, salt diets, starving, water load) using a genetically modified mouse model (cGKII-KO), but did not detect any striking differences between WT and cGKII-KO. Thus, cGKII is proposed to play only a marginal role in the adjustment of renal concentration ability to varying salt loads without water restriction or starving conditions. When WT mice were subjected to a volume load (performed by application of a 10-mM glucose solution (3% of BW) via feeding needle), they exhibited a potent diuresis. In contrast, urine volume was decreased significantly in cGKII-KO. We showed that AQP2 plasma membrane (PM) abundance was reduced for about 50% in WT upon volume load, therefore, this might be a main cause for the enhanced diuresis. In contrast, cGKII-KO mice almost completely failed to decrease AQP2-PM distribution. This significant difference between both genotypes is not induced by an altered p-Ser256-AQP2 phosphorylation, as phosphorylation at this site decreases similarly in WT and KO. Furthermore, sodium excretion was lowered in cGKII-KO mice during volume load. In summary, cGKII is only involved to a minor extent in the regulation of basal renal concentration ability. By contrast, cGKII-KO mice are not able to handle an acute volume load. Our results suggest that membrane insertion of AQP2 is inhibited by cGMP/cGKII.
Energy Technology Data Exchange (ETDEWEB)
Campa, Julia [Barcelona, Autonoma U.; Flaugher, Brenna [Fermilab; Estrada, Juan [Fermilab
2015-12-04
The knowledge of the scatter in the mass-observable relation is a key ingredient for a cosmological analysis based on galaxy clusters in a photometric survey. We demonstrate here how the linear bias measured in the correlation function for clusters can be used to determine the value of the scatter. The new method is tested in simulations of a 5.000 square degrees optical survey up to z~1, similar to the ongoing Dark Energy Survey. The results indicate that the scatter can be measured with a precision of 5% using this technique.
Energy Technology Data Exchange (ETDEWEB)
Hammon, Matthias; Janka, Rolf; Dankerl, Peter; Kammerer, Ferdinand J.; Uder, Michael; Rompel, Oliver [University Hospital Erlangen, Department of Radiology, Erlangen (Germany); Gloeckler, Martin; Dittrich, Sven [University Hospital Erlangen, Department of Pediatric Cardiology, Erlangen (Germany)
2015-05-01
Cardiac MRI is an accurate and reproducible technique for the assessment of left ventricular volumes and function. The accuracy of automated segmentation and the effects of manual adjustments have not been determined in children. To evaluate automated segmentation and the effects of manual adjustments for left ventricular parameter quantification in pediatric cardiac MR images. Left ventricular parameters were evaluated in 45 children with suspected myocarditis (age 13.4 ± 3.5 years, range 4-17 years) who underwent cardiac MRI. Dedicated software was used to automatically segment and adjust the parameters. Results of end-diastolic volume, end-systolic volume, stroke volume, myocardial mass, and ejection fraction were documented before and after apex/base adjustment and after apex/base/myocardial contour adjustment. The software successfully detected the left ventricle in 42 of 45 (93.3%) children; failures occurred in the smallest and youngest children. Of those 42 children, automatically segmented end-diastolic volume (EDV) was 151 ± 47 ml, and after apex/base adjustment it was 146 ± 45 ml, after apex/base/myocardial contour adjustment 146 ± 45 ml. The corresponding results for end-systolic volume (ESV) were 66 ± 32 ml, 63 ± 29 ml and 64 ± 28 ml; for stroke volume (SV) they were 85 ± 25 ml, 83 ± 23 ml and 83 ± 23 ml; for ejection fracture (EF) they were 57 ± 10%, 58 ± 9% and 58 ± 9%, and for myocardial mass (MM) they were 104 ± 31 g, 95 ± 31 g and 94 ± 30 g. Statistically significant differences were found when comparing the EDV/ESV/MM results, the EF results after apex/base adjustment and after apex/base/myocardial contour adjustment and the SV results (except for comparing the SVs after apex/base adjustment and after apex/base/myocardial contour adjustment). Automated segmentation for the evaluation of left ventricular parameters in pediatric MR images proved to be feasible. Automated segmentation + apex/base adjustment provided clinically
Schwenke, David W.; Truhlar, Donald G.
1990-01-01
The Generalized Newton Variational Principle for 3D quantum mechanical reactive scattering is briefly reviewed. Then three techniques are described which improve the efficiency of the computations. First, the fact that the Hamiltonian is Hermitian is used to reduce the number of integrals computed, and then the properties of localized basis functions are exploited in order to eliminate redundant work in the integral evaluation. A new type of localized basis function with desirable properties is suggested. It is shown how partitioned matrices can be used with localized basis functions to reduce the amount of work required to handle the complex boundary conditions. The new techniques do not introduce any approximations into the calculations, so they may be used to obtain converged solutions of the Schroedinger equation.
DEFF Research Database (Denmark)
Brothers, R M; Pecini, Redi; Dalsgaard, Morten;
2014-01-01
conditions prior to and during a simulated hemorrhagic challenge. Heat stress did not change indices of diastolic function. Subsequent volume infusion elevated indices of diastolic function, specifically early diastolic mitral annular tissue velocity (E') and early diastolic propagation velocity (E) relative......Volume loading normalizes tolerance to a simulated hemorrhagic challenge in heat-stressed individuals, relative to when these individuals are thermoneutral. The mechanism(s) by which this occurs is unknown. This project tested two unique hypotheses; that is, the elevation of central blood volume...... via volume loading while heat stressed would 1) increase indices of left ventricular diastolic function, and 2) preserve left ventricular end-diastolic volume (LVEDV) during a subsequent simulated hemorrhagic challenge induced by lower-body negative pressure (LBNP). Indices of left ventricular...
High-Dimensional Function Approximation With Neural Networks for Large Volumes of Data.
Andras, Peter
2017-01-25
Approximation of high-dimensional functions is a challenge for neural networks due to the curse of dimensionality. Often the data for which the approximated function is defined resides on a low-dimensional manifold and in principle the approximation of the function over this manifold should improve the approximation performance. It has been show that projecting the data manifold into a lower dimensional space, followed by the neural network approximation of the function over this space, provides a more precise approximation of the function than the approximation of the function with neural networks in the original data space. However, if the data volume is very large, the projection into the low-dimensional space has to be based on a limited sample of the data. Here, we investigate the nature of the approximation error of neural networks trained over the projection space. We show that such neural networks should have better approximation performance than neural networks trained on high-dimensional data even if the projection is based on a relatively sparse sample of the data manifold. We also find that it is preferable to use a uniformly distributed sparse sample of the data for the purpose of the generation of the low-dimensional projection. We illustrate these results considering the practical neural network approximation of a set of functions defined on high-dimensional data including real world data as well.
DEFF Research Database (Denmark)
Brothers, R M; Pecini, Redi; Dalsgaard, Morten
2014-01-01
via volume loading while heat stressed would 1) increase indices of left ventricular diastolic function, and 2) preserve left ventricular end-diastolic volume (LVEDV) during a subsequent simulated hemorrhagic challenge induced by lower-body negative pressure (LBNP). Indices of left ventricular...
Volume-assisted estimation of liver function based on Gd-EOB-DTPA-enhanced MR relaxometry
Energy Technology Data Exchange (ETDEWEB)
Haimerl, Michael; Schlabeck, Mona; Verloh, Niklas; Fellner, Claudia; Stroszczynski, Christian; Wiggermann, Philipp [University Hospital Regensburg, Department of Radiology, Regensburg (Germany); Zeman, Florian [University Hospital Regensburg, Center for Clinical Trials, Regensburg (Germany); Nickel, Dominik [MR Applications Development, Siemens AG, Healthcare Sector, Erlangen (Germany); Barreiros, Ana Paula [University Hospital Regensburg, Department of Internal Medicine I, Regensburg (Germany); Loss, Martin [University Hospital Regensburg, Department of Surgery, Regensburg (Germany)
2016-04-15
To determine whether liver function as determined by indocyanine green (ICG) clearance can be estimated quantitatively from hepatic magnetic resonance (MR) relaxometry with gadoxetic acid (Gd-EOB-DTPA). One hundred and seven patients underwent an ICG clearance test and Gd-EOB-DTPA-enhanced MRI, including MR relaxometry at 3 Tesla. A transverse 3D VIBE sequence with an inline T1 calculation was acquired prior to and 20 minutes post-Gd-EOB-DTPA administration. The reduction rate of T1 relaxation time (rrT1) between pre- and post-contrast images and the liver volume-assisted index of T1 reduction rate (LVrrT1) were evaluated. The plasma disappearance rate of ICG (ICG-PDR) was correlated with the liver volume (LV), rrT1 and LVrrT1, providing an MRI-based estimated ICG-PDR value (ICG-PDR{sub est}). Simple linear regression model showed a significant correlation of ICG-PDR with LV (r = 0.32; p = 0.001), T1{sub post} (r = 0.65; p < 0.001) and rrT1 (r = 0.86; p < 0.001). Assessment of LV and consecutive evaluation of multiple linear regression model revealed a stronger correlation of ICG-PDR with LVrrT1 (r = 0.92; p < 0.001), allowing for the calculation of ICG-PDR{sub est}. Liver function as determined using ICG-PDR can be estimated quantitatively from Gd-EOB-DTPA-enhanced MR relaxometry. Volume-assisted MR relaxometry has a stronger correlation with liver function than does MR relaxometry. (orig.)
Millimeter Wave Scattering from Neutral and Charged Water Droplets
Heifetz, Alexander; Liao, Shaolin; Gopalsami, N Sami; Raptis, A C Paul
2010-01-01
We investigated 94GHz millimeter wave (MMW) scattering from neutral and charged water mist produced in the laboratory with an ultrasonic atomizer. Diffusion charging of the mist was accomplished with a negative ion generator (NIG). We observed increased forward and backscattering of MMW from charged mist, as compared to MMW scattering from an uncharged mist. In order to interpret the experimental results, we developed a model based on classical electrodynamics theory of scattering from a dielectric sphere with diffusion-deposited mobile surface charge. In this approach, scattering and extinction cross-sections are calculated for a charged Rayleigh particle with effective dielectric constant consisting of the volume dielectric function of the neutral sphere and surface dielectric function due to the oscillation of the surface charge in the presence of applied electric field. For small droplets with (radius smaller than 100nm), this model predicts increased MMW scattering from charged mist, which is qualitative...
Directory of Open Access Journals (Sweden)
A. Gogoi
2011-09-01
Full Text Available Scattering properties of bentonite clay particles were investigated at 543.5 nm incident laser wavelength by using a designed and fabricated light scattering setup. The scattering samples were held in front of a laser beam by using a transparent cylindrical thermosetting epoxy matrix.
Dimensionality Reduction on Multi-Dimensional Transfer Functions for Multi-Channel Volume Data Sets
Kim, Han Suk; Schulze, Jürgen P.; Cone, Angela C.; Sosinsky, Gina E.; Martone, Maryann E.
2011-01-01
The design of transfer functions for volume rendering is a non-trivial task. This is particularly true for multi-channel data sets, where multiple data values exist for each voxel, which requires multi-dimensional transfer functions. In this paper, we propose a new method for multi-dimensional transfer function design. Our new method provides a framework to combine multiple computational approaches and pushes the boundary of gradient-based multi-dimensional transfer functions to multiple channels, while keeping the dimensionality of transfer functions at a manageable level, i.e., a maximum of three dimensions, which can be displayed visually in a straightforward way. Our approach utilizes channel intensity, gradient, curvature and texture properties of each voxel. Applying recently developed nonlinear dimensionality reduction algorithms reduces the high-dimensional data of the domain. In this paper, we use Isomap and Locally Linear Embedding as well as a traditional algorithm, Principle Component Analysis. Our results show that these dimensionality reduction algorithms significantly improve the transfer function design process without compromising visualization accuracy. We demonstrate the effectiveness of our new dimensionality reduction algorithms with two volumetric confocal microscopy data sets. PMID:21841914
Directory of Open Access Journals (Sweden)
Lirong Tan
2017-09-01
Full Text Available In this paper, we investigated the problem of computer-aided diagnosis of Attention Deficit Hyperactivity Disorder (ADHD using machine learning techniques. With the ADHD-200 dataset, we developed a Support Vector Machine (SVM model to classify ADHD patients from typically developing controls (TDCs, using the regional brain volumes as predictors. Conventionally, the volume of a brain region was considered to be an anatomical feature and quantified using structural magnetic resonance images. One major contribution of the present study was that we had initially proposed to measure the regional brain volumes using fMRI images. Brain volumes measured from fMRI images were denoted as functional volumes, which quantified the volumes of brain regions that were actually functioning during fMRI imaging. We compared the predictive power of functional volumes with that of regional brain volumes measured from anatomical images, which were denoted as anatomical volumes. The former demonstrated higher discriminative power than the latter for the classification of ADHD patients vs. TDCs. Combined with our two-step feature selection approach which integrated prior knowledge with the recursive feature elimination (RFE algorithm, our SVM classification model combining functional volumes and demographic characteristics achieved a balanced accuracy of 67.7%, which was 16.1% higher than that of a relevant model published previously in the work of Sato et al. Furthermore, our classifier highlighted 10 brain regions that were most discriminative in distinguishing between ADHD patients and TDCs. These 10 regions were mainly located in occipital lobe, cerebellum posterior lobe, parietal lobe, frontal lobe, and temporal lobe. Our present study using functional images will likely provide new perspectives about the brain regions affected by ADHD.
Hajireza, Parsin; Forbrich, Alexander; Zemp, Roger
2014-02-01
In this paper a multi-wavelength optical-resolution photoacoustic microscopy (OR-PAM) system using stimulated Raman scattering is demonstrated for both phantom and in vivo imaging. A 1-ns pulse width ytterbium-doped fiber laser is coupled into a single-mode polarization maintaining fiber. Discrete Raman-shifted wavelength peaks extending to nearly 800 nm are generated with pulse energies sufficient for OR-PAM imaging. Bandpass filters are used to select imaging wavelengths. A dual-mirror galvanometer system was used to scan the focused outputs across samples of carbon fiber networks, 200μm dye-filled tubes, and Swiss Webster mouse ears. Photoacoustic signals were collected in transmission mode and used to create maximum amplitude projection C-scan images. Double dye experiments and in vivo oxygen saturation estimation confirmed functional imaging potential.
National Research Council Canada - National Science Library
Yinan Wang; Yiying Song; Xueting Li; Lin Zhang; Jia Liu
2017-01-01
..., as suggested by the optimal parenting theory. Here, we tested the hypothesis that the effect of parental care on offspring hippocampal volume varies as a function of parental overprotection with a large cohort of young adult participants (N = 257...
National Oceanic and Atmospheric Administration, Department of Commerce — The dataset consists of calculated annual and monthly mean ocean volume transport stream function on 1 degree resolution using the WOA13 (T, S) and corresponding...
Excitation functions of proton-proton elastic scattering at intermediate energies
Scobel, W.; Dohrmann, F.; Bisplinghoff, J.; Hinterberger, F.; Scobel, W.; Altmeier, M.; Bauer, F.; Bisplinghoff, J.; Bissel, T.; Bollmann, R.; Busch, M.; Büßer, K.; Cloth, P.; Danie, R.; Diehl, O.; Dohrmann, F.; Engelhardt, H. P.; Ernst, J.; Eversheim, P. D.; Felden, O.; Flammer, J.; Gasthuber, M.; Gebel, R.; Greiff, J.; Groß, A.; Groß-Hardt, R.; Hebbel, K.; Hinterberger, F.; Hüskes, T.; Jahn, R.; Koch, I.; Langkau, R.; Lindemann, T.; Lindlein, J.; Maier, R.; Maschuw, R.; Mayer-Kuckuk, T.; Pfuff, M.; Prasuhn, D.; Rohdjeß, H.; Rosendaal, D.; von Rossen, P.; Schirm, N.; Schulz-Rojahn, M.; Schwarz, V.; Scobel, W.; Steinbeck, S.; Sterzenbach, G.; Thomas, S.; Trelle, H. J.; Walker, M.; Weise, E.; Wellinghausen, A.; Woller, K.; Ziegler, R.; EDDA Collaboration at COSY; EDDA Collaboration
1998-03-01
Excitation functions of proton-proton elastic cross sections have been measured in narrow momentum steps Δp = 28 MeV/c in the kinetic energy range from 0.5 to 2.5 GeV and the angular range 35° ≤ Θcm ≤ 90° with a detector providing ΔΘcm ≈ 1.4° resolution and 82% solid angle coverage. Measurements have been performed continuously during projectile acceleration in the Cooler Synchrotron COSY with an internal CH 2 fiber target; background corrections were derived from measurements with a carbon fiber target and from Monte Carlo simulations of inelastic pp contributions. Particular care was taken to monitor the luminosity as a function of beam energy. The results provide excitation functions and angular distributions of unprecedented precision and internal consistency. The measured cross sections are compared to recent phase shift analyses, and their impact on the present solution SM97 [1] is discussed.
Remizovich, V. S.
2010-06-01
It is commonly accepted that the Schwarzschild-Schuster two-flux approximation (1905, 1914) can be employed only for the calculation of the energy characteristics of the radiation field (energy density and energy flux density) and cannot be used to characterize the angular distribution of radiation field. However, such an inference is not valid. In several cases, one can calculate the radiation intensity inside matter and the reflected radiation with the aid of this simplest approximation in the transport theory. In this work, we use the results of the simplest one-parameter variant of the two-flux approximation to calculate the angular distribution (reflection function) of the radiation reflected by a semi-infinite isotropically scattering dissipative medium when a relatively broad beam is incident on the medium at an arbitrary angle relative to the surface. We do not employ the invariance principle and demonstrate that the reflection function exhibits the multiplicative property. It can be represented as a product of three functions: the reflection function corresponding to the single scattering and two identical h functions, which have the same physical meaning as the Ambartsumyan-Chandrasekhar function ( H) has. This circumstance allows a relatively easy derivation of simple analytical expressions for the H function, total reflectance, and reflection function. We can easily determine the relative contribution of the true single scattering in the photon backscattering at an arbitrary probability of photon survival Λ. We compare all of the parameters of the backscattered radiation with the data resulting from the calculations using the exact theory of Ambartsumyan, Chandrasekhar, et al., which was developed decades after the two-flux approximation. Thus, we avoid the application of fine mathematical methods (the Wiener-Hopf method, the Case method of singular functions, etc.) and obtain simple analytical expressions for the parameters of the scattered radiation
DEFF Research Database (Denmark)
Brothers, R M; Pecini, Redi; Dalsgaard, M;
2014-01-01
Volume loading normalizes tolerance to a simulated hemorrhagic challenge in heat-stressed individuals, relative to when these individuals are thermoneutral. The mechanism(s) by which this occurs is unknown. This project tested two unique hypotheses; that is, the elevation of central blood volume...... via volume loading while heat stressed would 1) increase indices of left ventricular diastolic function, and 2) preserve left ventricular end-diastolic volume (LVEDV) during a subsequent simulated hemorrhagic challenge induced by lower-body negative pressure (LBNP). Indices of left ventricular...... diastolic function were evaluated in nine subjects during the following conditions: thermoneutral, heat stress, and heat stress after acute volume loading sufficient to return ventricular filling pressures toward thermoneutral levels. LVEDV was also measured in these subjects during the aforementioned...
Zhou, Liang
2013-02-01
Multivariate volumetric datasets are important to both science and medicine. We propose a transfer function (TF) design approach based on user selected samples in the spatial domain to make multivariate volumetric data visualization more accessible for domain users. Specifically, the user starts the visualization by probing features of interest on slices and the data values are instantly queried by user selection. The queried sample values are then used to automatically and robustly generate high dimensional transfer functions (HDTFs) via kernel density estimation (KDE). Alternatively, 2D Gaussian TFs can be automatically generated in the dimensionality reduced space using these samples. With the extracted features rendered in the volume rendering view, the user can further refine these features using segmentation brushes. Interactivity is achieved in our system and different views are tightly linked. Use cases show that our system has been successfully applied for simulation and complicated seismic data sets. © 2013 IEEE.
Goldstone bosons in a finite volume the partition function to three loops
Bietenholz, W
1994-01-01
A system of Goldstone bosons - stemming from a symmetry breaking $O(N) \\to O(N-1)$ - in a finite volume at finite temperature is considered. In the framework of dimensional regularization, the partition function is calculated to 3 loops for 3 and 4 dimensions, where Polyakov's measure for the functional integration is applied. Although the underlying theory is the non-linear $\\sigma $ model, the 3 loop result turns out to be renormalizable in the sense that all the singularities can be absorbed by the couplings occuring so far. In finite volume, this property is highly non trivial and confirms the method for the measure. We also show that the result coincides with the one obtained using the Faddeev- Popov measure. This is also true for the maximal generalization of Polyakov's measure: none of the additional invariant terms that can be added contributes to the dimensionally regularized system. Our phenomenological Lagrangian describes e.g. 2 flavor chiral QCD as well as the classical Heisenberg model, but ther...
A Clustering-Based Automatic Transfer Function Design for Volume Visualization
Directory of Open Access Journals (Sweden)
Tianjin Zhang
2016-01-01
Full Text Available The two-dimensional transfer functions (TFs designed based on intensity-gradient magnitude (IGM histogram are effective tools for the visualization and exploration of 3D volume data. However, traditional design methods usually depend on multiple times of trial-and-error. We propose a novel method for the automatic generation of transfer functions by performing the affinity propagation (AP clustering algorithm on the IGM histogram. Compared with previous clustering algorithms that were employed in volume visualization, the AP clustering algorithm has much faster convergence speed and can achieve more accurate clustering results. In order to obtain meaningful clustering results, we introduce two similarity measurements: IGM similarity and spatial similarity. These two similarity measurements can effectively bring the voxels of the same tissue together and differentiate the voxels of different tissues so that the generated TFs can assign different optical properties to different tissues. Before performing the clustering algorithm on the IGM histogram, we propose to remove noisy voxels based on the spatial information of voxels. Our method does not require users to input the number of clusters, and the classification and visualization process is automatic and efficient. Experiments on various datasets demonstrate the effectiveness of the proposed method.
Kim, Euitae; Shidahara, Miho; Tsoumpas, Charalampos; McGinnity, Colm J; Kwon, Jun Soo; Howes, Oliver D; Turkheimer, Federico E
2013-06-01
We validated the use of a novel image-based method for partial volume correction (PVC), structural-functional synergistic resolution recovery (SFS-RR) for the accurate quantification of dopamine synthesis capacity measured using [(18)F]DOPA positron emission tomography. The bias and reliability of SFS-RR were compared with the geometric transfer matrix (GTM) method. Both methodologies were applied to the parametric maps of [(18)F]DOPA utilization rates (ki(cer)). Validation was first performed by measuring repeatability on test-retest scans. The precision of the methodologies instead was quantified using simulated [(18)F]DOPA images. The sensitivity to the misspecification of the full-width-half-maximum (FWHM) of the scanner point-spread-function on both approaches was also assessed. In the in-vivo data, the ki(cer) was significantly increased by application of both PVC procedures while the reliability remained high (intraclass correlation coefficients >0.85). The variability was not significantly affected by either PVC approach (<10% variability in both cases). The corrected ki(cer) was significantly influenced by the FWHM applied in both the acquired and simulated data. This study shows that SFS-RR can effectively correct for partial volume effects to a comparable degree to GTM but with the added advantage that it enables voxelwise analyses, and that the FWHM used can affect the PVC result indicating the importance of accurately calibrating the FWHM used in the recovery model.
Reduction of Pulmonary Function After Surgical Lung Resections of Different Volume
Cukic, Vesna
2014-01-01
Introduction: In recent years an increasing number of lung resections are being done because of the rising prevalence of lung cancer that occurs mainly in patients with limited lung function, what is caused with common etiologic factor - smoking cigarettes. Objective: To determine how big the loss of lung function is after surgical resection of lung of different range. Methods: The study was done on 58 patients operated at the Clinic for thoracic surgery KCU Sarajevo, previously treated at the Clinic for pulmonary diseases “Podhrastovi” in the period from 01.06.2012. to 01.06.2014. The following resections were done: pulmectomy (left, right), lobectomy (upper, lower: left and right). The values of postoperative pulmonary function were compared with preoperative ones. As a parameter of lung function we used FEV1 (forced expiratory volume in one second), and changes in FEV1 are expressed in liters and in percentage of the recorded preoperative and normal values of FEV1. Measurements of lung function were performed seven days before and 2 months after surgery. Results: Postoperative FEV1 was decreased compared to preoperative values. After pulmectomy the maximum reduction of FEV1 was 44%, and after lobectomy it was 22% of the preoperative values. Conclusion: Patients with airway obstruction are limited in their daily life before the surgery, and an additional loss of lung tissue after resection contributes to their inability. Potential benefits of lung resection surgery should be balanced in relation to postoperative morbidity and mortality. PMID:25568542
Energy Technology Data Exchange (ETDEWEB)
Novaes, Marcel [Instituto de Física, Universidade Federal de Uberlândia, Av. João Naves de Ávila, 2121, Uberlândia, MG 38408-100 (Brazil)
2015-06-15
We consider S-matrix correlation functions for a chaotic cavity having M open channels, in the absence of time-reversal invariance. Relying on a semiclassical approximation, we compute the average over E of the quantities Tr[S{sup †}(E − ϵ) S(E + ϵ)]{sup n}, for general positive integer n. Our result is an infinite series in ϵ, whose coefficients are rational functions of M. From this, we extract moments of the time delay matrix Q = − iħS{sup †}dS/dE and check that the first 8 of them agree with the random matrix theory prediction from our previous paper [M. Novaes, J. Math. Phys. 56, 062110 (2015)].
Kim, K S
2005-01-01
Using a relativistic mean-field single particle knock-out model for (e,e') reactions on nuclei, we investigate approximate treatments of Coulomb distortion effects and the extraction of longitudinal and transverse structure functions. We show that an effective momentum approximation (EMA) when coupled with a focusing factor provides a good description of the transverse contributions to the (e,e') cross sections for electron energies above 300 MeV on 208Pb. This approximation is not as good for the longitudinal contributions even for incident electron eneriges above 1 GeV and if one requires very precise extraction of longitudinal and transverse structure functions in the quasielastic region it is necessary to utilize distortion factors based on a nuclear model and a more accurate inclusion of Coulomb distortion effects.
Inelastic electron scattering as an indicator of clustering in wave functions
Energy Technology Data Exchange (ETDEWEB)
NONE
1998-09-01
While the shell model is the most fundamental of nuclear structure models, states in light nuclei also have been described successfully in terms of clusters. Indeed, Wildemuth and Tang have shown a correspondence between the cluster and shell models, the clusters arising naturally as correlations out of the shell model Hamiltonian. For light nuclei, the cluster model reduces the many-body problem to a few-body one, with interactions occurring between the clusters. These interactions involve particle exchanges, since the nucleons may still be considered somewhat freely moving, with their motion not strictly confined to the clusters themselves. Such is the relation of the cluster model to the shell model. For a realistic shell model then, one may expect some evidence of clustering in the wave functions for those systems in which the cluster model is valid. The results obtained using the multi-{Dirac_h}{omega}shell model wave functions are closer in agreement with experiment than the results obtained using the 0{Dirac_h}{omega}wave functions. Yet in all cases, that level of agreement is not good, with the calculations underpredicting the measured values by at least a factor of two. This indicates that the shell model wave functions do not exhibit clustering behavior, which is expected to manifest itself at small momentum transfer. The exception is the transition to the 7{sup -}/2 state in {sup 7}Li, for which the value obtained from the {gamma}-decay width is in agreement with the value obtained from the MK3W and (0 + 2 + 4){Dirac_h}{omega}shell model calculations 17 refs., 1 tab., 2 figs.
Correlation functions for fully or partially state-resolved reactive scattering calculations
Manthe, Uwe; Welsch, Ralph
2014-06-01
Flux correlation functions and the quantum transition state concept are important tools for the accurate description of polyatomic reaction processes. Combined with the multi-configurational time-dependent Hartree approach, they facilitate rigorous full-dimensional calculations of cumulative and initial-state selected reaction probabilities for six atom reactions. In recent work [R. Welsch, F. Huarte-Larrañaga, and U. Manthe, J. Chem. Phys. 136, 064117 (2012)], an approach which allows one to calculate also state-to-state reaction probabilities within the quantum transition state concept has been introduced. This article presents further developments. Alternative generalized flux correlation functions are introduced and discussed. Equations for the calculation of fully state-resolved differential cross section using arbitrary definitions of the body fixed frame are derived. An approach for the efficient calculation of partially state-resolved observables as a function of the collision energy is introduced. Finally, numerical test studying the D + H2 reaction illustrate important aspects of the formalism.
Correlation functions for fully or partially state-resolved reactive scattering calculations
Energy Technology Data Exchange (ETDEWEB)
Manthe, Uwe, E-mail: uwe.manthe@uni-bielefeld.de; Welsch, Ralph, E-mail: rwelsch@uni-bielefeld.de [Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld (Germany)
2014-06-28
Flux correlation functions and the quantum transition state concept are important tools for the accurate description of polyatomic reaction processes. Combined with the multi-configurational time-dependent Hartree approach, they facilitate rigorous full-dimensional calculations of cumulative and initial-state selected reaction probabilities for six atom reactions. In recent work [R. Welsch, F. Huarte-Larrañaga, and U. Manthe, J. Chem. Phys. 136, 064117 (2012)], an approach which allows one to calculate also state-to-state reaction probabilities within the quantum transition state concept has been introduced. This article presents further developments. Alternative generalized flux correlation functions are introduced and discussed. Equations for the calculation of fully state-resolved differential cross section using arbitrary definitions of the body fixed frame are derived. An approach for the efficient calculation of partially state-resolved observables as a function of the collision energy is introduced. Finally, numerical test studying the D + H{sub 2} reaction illustrate important aspects of the formalism.
Correlation functions for fully or partially state-resolved reactive scattering calculations.
Manthe, Uwe; Welsch, Ralph
2014-06-28
Flux correlation functions and the quantum transition state concept are important tools for the accurate description of polyatomic reaction processes. Combined with the multi-configurational time-dependent Hartree approach, they facilitate rigorous full-dimensional calculations of cumulative and initial-state selected reaction probabilities for six atom reactions. In recent work [R. Welsch, F. Huarte-Larrañaga, and U. Manthe, J. Chem. Phys. 136, 064117 (2012)], an approach which allows one to calculate also state-to-state reaction probabilities within the quantum transition state concept has been introduced. This article presents further developments. Alternative generalized flux correlation functions are introduced and discussed. Equations for the calculation of fully state-resolved differential cross section using arbitrary definitions of the body fixed frame are derived. An approach for the efficient calculation of partially state-resolved observables as a function of the collision energy is introduced. Finally, numerical test studying the D + H2 reaction illustrate important aspects of the formalism.
Absolute cross-section normalization of magnetic neutron scattering data
Xu, Guangyong; Xu, Zhijun; Tranquada, J. M.
2013-08-01
We discuss various methods to obtain the resolution volume for neutron scattering experiments, in order to perform absolute normalization on inelastic magnetic neutron scattering data. Examples from previous experiments are given. We also try to provide clear definitions of a number of physical quantities which are commonly used to describe neutron magnetic scattering results, including the dynamic spin correlation function and the imaginary part of the dynamic susceptibility. Formulas that can be used for general purposes are provided and the advantages of the different normalization processes are discussed.
Yamaguchi, Tsuyoshi
2016-11-01
The frequency-dependent shear viscosity of two representative viscous liquids, o-terphenyl and glycerin, was experimentally determined at several temperatures and compared with the intermediate scattering functions reported in the literature. A comparison based on mode-coupling theory succeeded in relating the frequency-dependent shear viscosity with the intermediate scattering function at the main peak of the static structure factor. It suggests that the slow relaxation mode of the shear viscosity of both liquids is governed by the density fluctuation at the main peak of the static structure factor, in spite of the differences in the details of their intermolecular interactions.
Microscopic Calculation of the Inclusive Electron Scattering Structure Function in 16O
Mihaila, Bogdan; Heisenberg, Jochen H.
2000-02-01
We calculate the charge form factor and the longitudinal structure function for 16O and compare with the available experimental data, up to a momentum transfer of 4 fm-1. The ground-state correlations are generated using the coupled-cluster [ exp\\(S\\)] method, together with the realistic v18 NN interaction and the Urbana IX three-nucleon interaction. Center-of-mass corrections are dealt with by adding a center-of-mass Hamiltonian to the usual internal Hamiltonian, and by means of a many-body expansion for the computation of the observables measured in the center-of-mass system.
Microscopic calculation of the inclusive electron scattering structure function in O-16
Mihaila, B; Mihaila, Bogdan; Heisenberg, Jochen
2000-01-01
We calculate the charge form factor and the longitudinal structure function for $^{16}$O and compare with the available experimental data, up to a momentum transfer of 4 fm$^{-1}$. The ground state correlations are generated using the coupled cluster [exp(S}] method, together with the realistic v-18 NN interaction and the Urbana IX three-nucleon interaction. Center-of-mass corrections are dealt with by adding a center-of-mass Hamiltonian to the usual internal Hamiltonian, and by means of a many-body expansion for the computation of the observables measured in the center-of-mass system.
Nucleon structure functions from. nu. sub. mu. -Fe scattering at the Tevatron
Energy Technology Data Exchange (ETDEWEB)
Smith, W.H.; Sandler, P.H. (Wisconsin Univ., Madison (USA)); Merritt, F.S.; Oreglia, M.J.; Schumm, B.A. (Chicago Univ., IL (USA)); Arroyo, C.; Bachmann, K.T.; Blair, R.E.; Foudas, C.; King, B.J.; Lefmann, W.C.; Leung, W.C.; Mishra, S.R.; Oltman, E.; Quintas, P.Z.; Rabinowitz, S.A.; Sciulli, F.J.; Seligman, W.G.; Shaevitz, M.H. (Columbia Univ., New York (USA)); Bernstein, R.H.; Borcherding, F.O.; Fisk, H.E.; Lamm, M.J.; Marsh, W.; Merritt, K.W.; Schellman, H.; Yovanovitch, D. (Fermi National Accelerator Lab., Batavia, IL (USA)); Bodek, A.; Budd, H.S.; De Barbaro, P.; Sakumoto, W.K. (Rochester Univ., NY (USA))
1991-04-01
Preliminary measurements of structure functions have been made from a sample of 1,281,000 {nu}{sub {mu}} and 270,000 anti {nu}{sub {mu}} charged current events with 30 GeV < E{sub {nu}} < 600 GeV. These include a new value of the Gross-Llewellyn Smith Sum Rule, {integral} (1/x)(xF{sub 3})dx = 2.66 {+-} .03 (stat) {+-} .08 (syst), the ratio of cross sections, {sigma}(anti {nu}{sub {mu}})/{sigma}({nu}{sub {mu}}) = .511 {+-} .002 (stat) {+-} .005 (syst), and an analysis of the Q{sup 2} evolution of xF{sub 3}. (orig.).
Unified Description of Electron-Nucleus Scattering within the Spectral Function Formalism.
Rocco, Noemi; Lovato, Alessandro; Benhar, Omar
2016-05-13
The formalism based on factorization and nuclear spectral functions has been generalized to treat transition matrix elements involving two-nucleon currents, whose contribution to the nuclear electromagnetic response in the transverse channel is known to be significant. We report the results of calculations of the inclusive electron-carbon cross section, showing that the inclusion of processes involving two-nucleon currents appreciably improves the agreement between theory and data in the dip region, between the quasielastic and Δ-production peaks. The relation to approaches based on the independent particle of the nucleus and the implications for the analysis of flux-integrated neutrino-nucleus cross sections are discussed.
Energy Technology Data Exchange (ETDEWEB)
Alekhin, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Institute for High Energy Physics, Protvino (Russian Federation); Bluemlein, J.; Klein, S.; Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
2009-08-15
We determine the parton distribution functions (PDFs) in a next-to-next-to-leading order (NNLO) QCD-analysis of the inclusive neutral-current deep-inelastic-scattering (DIS) world data combined with the neutrino-nucleon DIS di-muon data and the fixed-target Drell-Yan data. The PDF-evolution is performed in the N{sub f} = 3 fixed-flavor scheme and supplementary sets of PDFs in the 4- and 5-flavor schemes are derived from the results in the 3-flavor scheme using matching conditions. The charm-quark DIS contribution is calculated in a general-mass variable-flavor-number (GMVFN) scheme interpolating between the zero mass 4-flavor scheme at asymptotically large values of momentum transfer Q{sup 2} and the 3-flavor scheme prescription of Buza-Matiounine-Smith-van Neerven (BMSN) at the value of Q{sup 2} = m{sub c}{sup 2}. The results in the GMVFN scheme are compared with those of the fixed-flavor scheme and other prescriptions used in global fits of PDFs. The strong coupling constant is measured at an accuracy of {approx} 1.5%. We obtain at NNLO {alpha}{sub s}(M{sub Z}{sup 2})=0.1135{+-}0.0014 in the fixed-flavor scheme and {alpha}{sub s}(M{sub Z}{sup 2})=0.1129{+-}0.0014 applying the BMSN-prescription. The implications for important standard candle and hard scattering processes at hadron colliders are illustrated. Predictions for cross sections of W{sup {+-}}- and Z-boson, the top-quark pair- and Higgs-boson production at the Tevatron and the LHC based on the 5-flavor PDFs of the present analysis are provided. (orig.)
Leloup, Frédéric B.; De Ketelaere, Ward; Audenaert, Jan; Hanselaer, Peter
2014-02-01
The bidirectional scatter distribution function (BSDF) characterizes the scattering properties of a material for any angle of illumination or viewing, and offers as such a complete description of the spatial optical characteristics of the surface. An accurate determination of the BSDF is important in many scientific domains, such as computer graphics, architectural and lighting design, and the field of material appearance characterization (e.g. the color and gloss properties). Many BSDF measuring instruments have been reported in the literature. The majority of these instruments are goniometric measurement devices, by use of which the BSDF is determined by scanning all incoming and outgoing light flux directions in sequence. For this, the sample, detector, and/or source perform relative individual movements. In result, the major restriction of this type of instruments constitutes the measurement time, which may run to the order of several hours depending on the accuracy (angular resolution) and the complexity (spectral coverage, absolute measurement capability, etc.) of the reported measurement data. This paper describes the results of a feasibility study, in which an alternative goniometric measurement system is designed, enabling to acquire the photometric BSDF in a full three-dimensional (3D) space, with a high mechanical angular resolution (0.1°) in a time efficient way (about 30 minutes). A near-field goniophotometer, originally intended to measure luminance intensity distributions and luminous fluxes of light sources and luminaires, was converted for this purpose. Besides a discussion of the design and the measurement procedure, test sample measurements are presented to illustrate the versatility of the device.
Assessment of hepatic functional reserve by cirrhosis grading and liver volume measurement using CT
Institute of Scientific and Technical Information of China (English)
无
2007-01-01
AIM: To explore a method for quantitative assessment of hepatic functional reserve by combining computed tomography (CT) volumetry with CT grading of liver cirrhosis before liver resection in patients with hepatocellular carcinoma.METHODS: CT images of 55 patients undergoing liver resection were studied prospectively. The degree of liver cirrhosis was referred as "CT grade" and the percentage of remnant liver volume (PRLV) [PRLV = predicted RLV/predicted total liver volume (PTLV) × 100%;PTLV (mL) = 121.75 + 16.49 × body mass (kg)] were calculated by adding slice by slice of CT liver images.The postoperative RLV, pathologic stages of liver fibrosis in non-tumor area and survival time in these cases were analyzed.RESULTS: There was a significant difference in survival time between the group with PRLV ≤ 50% and the group with PRLV ＞ 50% (χ2= 4.988, P = 0.026), and between the group with CT grade 0/1 and the group with CT grade 2/3 (χ2= 5.429, P = 0.026). With combination of the both parameters, an oblique line was identified according to the distribution of 32 survivors versus 23 deceased subjects. The mortality rate above the line was 7.1% (1/14), and that below the line was 53.7% (22/41),indicating a significant difference between the two rates (χ2 = 9.281, P = 0.002, P ＜ 0.05).CONCLUSION: PRLV and CT grades are significantly correlated with hepatic functional reserve. The predicted line using these two parameters is useful in candidates undergoing liver resection for judging hepatic functional reserve.
Ramos, J G G S; Barbosa, A L R; Carlson, B V; Frederico, T; Hussein, M S
2016-01-01
We derive analytical expressions for the correlation functions of the electronic conductance fluctuations of an open quantum dot under several conditions. Both the variation of energy and that of an external parameter, such as an applied perpendicular or parallel magnetic fields, are considered in the general case of partial openness. These expressions are then used to obtain the ensemble-averaged density of maxima, a measure recently suggested to contain invaluable information concerning the correlation widths of chaotic systems. The correlation width is then calculated for the case of energy variation, and a significant deviation from the Weisskopf estimate is found in the case of two terminals. The results are extended to more than two terminals. All of our results are analytical. The use of these results in other fields, such as nuclei, where the system can only be studied through a variation of the energy, is then discussed.
Ree, Moonhor
2014-05-01
For advanced functional polymers such as biopolymers, biomimic polymers, brush polymers, star polymers, dendritic polymers, and block copolymers, information about their surface structures, morphologies, and atomic structures is essential for understanding their properties and investigating their potential applications. Grazing incidence X-ray scattering (GIXS) is established for the last 15 years as the most powerful, versatile, and nondestructive tool for determining these structural details when performed with the aid of an advanced third-generation synchrotron radiation source with high flux, high energy resolution, energy tunability, and small beam size. One particular merit of this technique is that GIXS data can be obtained facilely for material specimens of any size, type, or shape. However, GIXS data analysis requires an understanding of GIXS theory and of refraction and reflection effects, and for any given material specimen, the best methods for extracting the form factor and the structure factor from the data need to be established. GIXS theory is reviewed here from the perspective of practical GIXS measurements and quantitative data analysis. In addition, schemes are discussed for the detailed analysis of GIXS data for the various self-assembled nanostructures of functional homopolymers, brush, star, and dendritic polymers, and block copolymers. Moreover, enhancements to the GIXS technique are discussed that can significantly improve its structure analysis by using the new synchrotron radiation sources such as third-generation X-ray sources with picosecond pulses and partial coherence and fourth-generation X-ray laser sources with femtosecond pulses and full coherence.
Energy Technology Data Exchange (ETDEWEB)
Dimakis, N; Mion, T [Department of Physics and Geology, University of Texas-Pan American, Edinburg, TX 78539 (United States); Bunker, G, E-mail: dimakis@utpa.ed [Department of Biological Chemical and Physical Sciences, Illinois Institute of Technology, Chicago, IL 60616 (United States)
2009-11-15
We present an accurate and efficient technique for calculating thermal X-ray absorption fine structure (XAFS) Debye-Waller factors (DWFs) applicable to crystalline materials. Using Density Functional Theory on a 3x3x3 supercell pattern of MnO structure, under the nonlocal hybrid B3LYP functional paired with Gaussian local basis sets, we obtain the normal mode eigenfrequencies and eigenvectors; these parameters are in turn used to calculate single and multiple scattering XAFS DWFs. The DWFs obtained via this technique are temperature dependent expressions and can be used to substantially reduce the number of fitting parameters, when experimental spectra are fitted with a hypothetical structure. The size of the supercell size limits the R-space range that these parameters could be used. Therefore corresponding DWFs for paths outside of this range are calculated using the correlated Debye model. Our method is compared with prior cluster calculations and with corresponding values obtained from fitting experimental XAFS spectra on manganosite with simulated spectra.
Brain volume and cognitive function in adult survivors of childhood acute lymphoblastic leukemia.
Edelmann, Michelle N; Krull, Kevin R
2013-10-01
The survival rate for childhood acute lymphoblastic leukemia (ALL) is greater than 80%. However, many of these survivors develop long-term chronic health conditions, with a relatively common late effect being neurocognitive dysfunction. Although neurocognitive impairments have decreased in frequency and severity as treatment has evolved, there is a subset of survivors in the current treatment era that are especially vulnerable to the neurotoxic effects of ALL and its treatment. Additionally, little is known about long-term brain development as survivors mature into adulthood. A recent study by Zeller et al. compared neurocognitive function and brain volume in 130 adult survivors of childhood ALL to 130 healthy adults matched on age and sex. They identified the caudate as particularly sensitive to the neurotoxic effects of chemotherapy. We discuss the implications and limitations of this study, including how their findings support the concept of individual vulnerability to ALL and its treatment.
Multiple scattering effects on spaceborne lidar
Winker, David M.; Poole, Lamont R.
1992-01-01
A semianalytic Monte Carlo code originally developed for oceanographic calculations (Poole et al., 1981) has been modified for use in studying multiple scattering of space-based lidar. The approach is very similar to that described by Kunkel and Weinman (1976). The trajectory of each photon is followed from the transmitter through multiple scattering until the photon is either scattered backward out of the atmosphere, scattered forward into the ground and absorbed, or scattered out the sides of the cloud. The probability that the photon will return directly to the detector is computed and summed over all significant scattering events within the field of view of the detector. Multiple scattering of the lidar pulse causes an apparent increase in the transmittance of the medium. Multiple scattering effects for space-based lidar are more significant than for ground-based lidar due to the much larger beam diameter in the atmosphere. These larger diameters are due not only to the greater range between the lidar and the scattering volume, but also the need to maintain relatively large beam divergences to satisfy eye safety restrictions on the laser irradiance at the Earth's surface. The simulations presented here are for a wavelength of 1064 nm and the Deirmendjian C1 phase function, which yields an extinction coefficient of 17.259/km. We have looked at two cases: a space-based lidar at 296 km observing a C1 cloud 293 km from the lidar and, for comparison purposes, a ground-based lidar looking at a C1 cloud with a base height of either 2 km or 5 km. The C1 size distribution roughly approximates that of stratocumulus or altocumulus clouds (aufm Kampe and Weickmann, 1957).
Impact of endoscopic lung volume reduction on right ventricular myocardial function.
Directory of Open Access Journals (Sweden)
Carmen Pizarro
Full Text Available Endoscopic lung volume reduction (ELVR provides a minimally invasive therapy for patients with severe lung emphysema. As its impact on right ventricular (RtV function is undefined, we examined the extent of RtV functional changes following ELVR, as assessed by use of speckle tracking-based RtV deformation analysis.We enrolled 32 patients with severe emphysematous COPD scheduled for bronchoscopic LVR using endobronchial valves (Zephyr, PulmonX, Inc., comprising 16 matched clinical responders and 16 non-responders. Echocardiography was conducted one day prior to ELVR and at an eight-week postprocedural interval.Patients were predominantly of late middle-age (65.8 ± 8.7 yrs, male (62.5% and presented advanced COPD emphysema (means FEV1 and RV: 32.6% and 239.1% of predicted, respectively. After ELVR, RtV apical longitudinal strain improved significantly in the total study cohort (-7.96 ± 7.02% vs. -13.35 ± 11.48%, p = 0.04, whereas there were no significant changes in other parameters of RtV function such as RtV global longitudinal strain, TAPSE or pulmonary arterial systolic pressure. In responding patients, 6MWT-improvement correlated with a decrease in NT-proBNP (Pearson´s r: -0.53, p = 0.03. However, clinical non-responders did not exhibit any RtV functional improvement.ELVR beneficially impacts RtV functional parameters. Speckle tracking-based RtV apical longitudinal strain analysis allows early determination of RtV contractile gain and identification of clinical responsiveness.
Directory of Open Access Journals (Sweden)
Porter John B
2010-04-01
Full Text Available Abstract Aim We aimed to define reference ranges for right ventricular (RV volumes, ejection fraction (EF in thalassemia major patients (TM without myocardial iron overload. Methods and results RV volumes, EF and mass were measured in 80 TM patients who had no myocardial iron overload (myocardial T2* > 20 ms by cardiovascular magnetic resonance. All patients were receiving deferoxamine chelation and none had evidence of pulmonary hypertension or other cardiovascular comorbidity. Forty age and sex matched healthy non-anemic volunteers acted as controls. The mean RV EF was higher in TM patients than controls (males 66.2 ± 4.1% vs 61.6 ± 6%, p = 0.0009; females 66.3 ± 5.1% vs 62.6 ± 6.4%, p = 0.017, which yielded a raised lower threshold of normality for RV EF in TM patients (males 58.0% vs 50.0% and females 56.4% vs 50.1%. RV end-diastolic volume index was higher in male TM patients (mean 98.1 ± 17.3 mL vs 88.4 ± 11.2 mL/m2, p = 0.027, with a higher upper limit (132 vs 110 mL/m2 but this difference was of borderline significance for females (mean 86.5 ± 13.6 mL vs 80.3 ± 12.8 mL/m2, p = 0.09, with upper limit of 113 vs 105 mL/m2. The cardiac index was raised in TM patients (males 4.8 ± 1.0 L/min vs 3.4 ± 0.7 L/min, p Conclusion The normal ranges for functional RV parameters in TM patients with no evidence of myocardial iron overload differ from healthy non-anemic controls. The new reference RV ranges are important for determining the functional effects of myocardial iron overload in TM patients.
Introduction to neutron scattering
Energy Technology Data Exchange (ETDEWEB)
Fischer, W.E. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)
1996-11-01
We give here an introduction to the theoretical principles of neutron scattering. The relationship between scattering- and correlation-functions is particularly emphasized. Within the framework of linear response theory (justified by the weakness of the basic interaction) the relation between fluctuation and dissipation is discussed. This general framework explains the particular power of neutron scattering as an experimental method. (author) 4 figs., 4 refs.
Kibby, Michelle Y; Pavawalla, Shital P; Fancher, Jill B; Naillon, Angela J; Hynd, George W
2009-04-01
Because poor comprehension has been associated with small cerebral volume and there is a high comorbidity between developmental dyslexia, attention-deficit hyperactivity disorder (ADHD), and specific language impairment, the goal of this study was to determine whether cerebral volume is reduced in dyslexia and attention-deficit hyperactivity disorder in general, as some suggest, or whether the reduction in volume corresponds to poor receptive language functioning, regardless of the diagnosis. Participants included 46 children with and without dyslexia and attention-deficit hyperactivity disorder, aged 8 to 12 years. Our results indicated that cerebral volume was comparable between those with and without dyslexia and attention-deficit hyperactivity disorder overall. However, when groups were further divided into those with and without receptive language difficulties, children with poor receptive language had smaller volumes bilaterally as hypothesized. Nonetheless, the relationship between cerebral volume and receptive language was not linear; rather, our results suggest that small volume is associated with poor receptive language only in those with the smallest volumes in both dyslexia and attention-deficit hyperactivity disorder.
Simonsen, Ingve; Kryvi, Jacob B; Maradudin, Alexei A
2015-01-01
An expression is obtained on the basis of phase perturbation theory for the contribution to the mean differential reflection coefficient from the in-plane co-polarized component of the light scattered diffusely from a two-dimensional randomly rough dielectric surface when the latter is illuminated by s-polarized light. This result forms the basis for an approach to inverting experimental light scattering data to obtain the normalized surface height autocorrelation function of the surface. Several parametrized forms of this correlation function, and the minimization of a cost function with respect to the parameters defining these representations, are used in the inversion scheme. This approach also yields the rms height of the surface roughness, and the dielectric constant of the dielectric substrate if it is not known in advance. The input data used in validating this inversion consists of computer simulation results for surfaces defined by exponential and Gaussian surface height correlation functions, withou...
Effect of Sildenafil on Pressure–Volume Loop Measures of Ventricular Function in Fontan Patients
Butts, Ryan J.; Chowdhury, Shahryar M.; Baker, George H.; Bandisode, Varsha; Savage, Andrew J.; Atz, Andrew M.
2016-01-01
Sildenafil has been reported to improve exercise capacity in Fontan patients, but the physiologic mechanisms behind these findings are not completely understood. The objective of this study was to study the acute effect of sildenafil on pressure–volume loop (PVL) measures of ventricular function in Fontan patients. Patients after Fontan operation who were presenting for a clinically indicated catheterization were enrolled. Patients were randomized in a double-blinded fashion to receive placebo (n = 9) or sildenafil (n = 10) 30–90 min prior to catheterization. PVLs were recorded using microconductance catheters at baseline and after infusion of dobutamine (10 mcg/kg/min). The primary outcome was change in ventriculoarterial (VA) coupling. For the entire cohort, VA coupling trended toward improvement with dobutamine (1.4 ± 0.4 to 1.8 ± 0.9, p = 0.07). End-systolic elastance showed improvement (2.6 ± 0.9 to 3.8 ± 1.4 mmHg m2/ml, p sildenafil cohort trended toward having less of an improvement in VA coupling with dobutamine stress (p = 0.06). There were no differences between PVL measures of systolic or diastolic function between treatment groups, both at baseline and after dobutamine infusion. Patients with Fontan circulation had improved contractility and trended toward improvement in VA coupling with dobutamine stress. Acute sildenafil administration was not associated with improved PVL measurements of ventricular function in this population. These results suggest that clinical improvements seen with administration of sildenafil in Fontan patients are not associated with an acute improvement in ventricular function. PMID:26409473
Schafhitzel, Tobias; Rößler, Friedemann; Weiskopf, Daniel; Ertl, Thomas
2007-03-01
Modern medical imaging provides a variety of techniques for the acquisition of multi-modality data. A typical example is the combination of functional and anatomical data from functional Magnetic Resonance Imaging (fMRI) and anatomical MRI measurements. Usually, the data resulting from each of these two methods is transformed to 3D scalar-field representations to facilitate visualization. A common method for the visualization of anatomical/functional multi-modalities combines semi-transparent isosurfaces (SSD, surface shaded display) with other scalar visualization techniques like direct volume rendering (DVR). However, partial occlusion and visual clutter that typically result from the overlay of these traditional 3D scalar-field visualization techniques make it difficult for the user to perceive and recognize visual structures. This paper addresses these perceptual issues by a new visualization approach for anatomical/functional multi-modalities. The idea is to reduce the occlusion effects of an isosurface by replacing its surface representation by a sparser line representation. Those lines are chosen along the principal curvature directions of the isosurface and rendered by a flow visualization method called line integral convolution (LIC). Applying the LIC algorithm results in fine line structures that improve the perception of the isosurface's shape in a way that it is possible to render it with small opacity values. An interactive visualization is achieved by executing the algorithm completely on the graphics processing unit (GPU) of modern graphics hardware. Furthermore, several illumination techniques and image compositing strategies are discussed for emphasizing the isosurface structure. We demonstrate our method for the example of fMRI/MRI measurements, visualizing the spatial relationship between brain activation and brain tissue.
Hummer, Tom A; Kronenberger, William G; Wang, Yang; Anderson, Caitlin C; Mathews, Vincent P
2014-07-01
Prior research has indicated that self-reported violent media exposure is associated with poorer performance on some neuropsychological tests in adolescents. This study aimed to examine the relationship of executive functioning to violent television viewing in healthy young adult males and examine how brain structure is associated with media exposure measures. Sixty-five healthy adult males (ages 18-29) with minimal video game experience estimated their television viewing habits over the past year and, during the subsequent week, recorded television viewing time and characteristics in a daily media diary. Participants then completed a battery of neuropsychological laboratory tests quantifying executive functions and underwent a magnetic resonance imaging (MRI) scan. Aggregate measures of executive functioning were not associated with measures of overall television viewing (any content type) during the past week or year. However, the amount of television viewing of violent content only, as indicated by both past-year and daily diary measures, was associated with poorer scores on an aggregate score of inhibition, interference control and attention, with no relationship to a composite working memory score. In addition, violent television exposure, as measured with daily media diaries, was associated with reduced frontoparietal white matter volume. Future longitudinal work is necessary to resolve whether individuals with poor executive function and slower white matter growth are more drawn to violent programming, or if extensive media violence exposure modifies cognitive control mechanisms mediated primarily via prefrontal cortex. Impaired inhibitory mechanisms may be related to reported increases in aggression with higher media violence exposure. Copyright © 2014 Elsevier Inc. All rights reserved.
Human factors evaluation of teletherapy: Function and task analysis. Volume 2
Energy Technology Data Exchange (ETDEWEB)
Kaye, R.D.; Henriksen, K.; Jones, R. [Hughes Training, Inc., Falls Church, VA (United States); Morisseau, D.S.; Serig, D.I. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology
1995-07-01
As a treatment methodology, teletherapy selectively destroys cancerous and other tissue by exposure to an external beam of ionizing radiation. Sources of radiation are either a radioactive isotope, typically Cobalt-60 (Co-60), or a linear accelerator. Records maintained by the NRC have identified instances of teletherapy misadministration where the delivered radiation dose has differed from the radiation prescription (e.g., instances where fractions were delivered to the wrong patient, to the wrong body part, or were too great or too little with respect to the defined treatment volume). Both human error and machine malfunction have led to misadministrations. Effective and safe treatment requires a concern for precision and consistency of human-human and human-machine interactions throughout the course of therapy. The present study is the first part of a series of human factors evaluations for identifying the root causes that lead to human error in the teletherapy environment. The human factors evaluations included: (1) a function and task analysis of teletherapy activities, (2) an evaluation of the human-system interfaces, (3) an evaluation of procedures used by teletherapy staff, (4) an evaluation of the training and qualifications of treatment staff (excluding the oncologists), (5) an evaluation of organizational practices and policies, and (6) an identification of problems and alternative approaches for NRC and industry attention. The present report addresses the function and task analysis of teletherapy activities and provides the foundation for the conduct of the subsequent evaluations. The report includes sections on background, methodology, a description of the function and task analysis, and use of the task analysis findings for the subsequent tasks. The function and task analysis data base also is included.
Bassauer, S; Tamii, A
2016-01-01
Gamma strength functions (GSFs) and level densities (LDs) are essential ingredients of statistical nuclear reaction theory with many applications in astrophysics, reactor design, and waste transmutation. The aim of the present work is a test of systematic parametrizations of the GSF recommended by the RIPL-3 data base for the case of $^{208}$Pb. The upward GSF and LDs in $^{208}$Pb are compared to gamma decay data from an Oslo-type experiment to examine the validity of the Brink-Axel (BA) hypothesis. The E1 and M1 parts of the total GSF are determined from high-resolution forward angle inelastic proton scattering data taken at 295 MeV at RCNP, Osaka, Japan. Total LDs in $^{208}$Pb are derived from $1^-$ LDs extracted with a fluctuation analysis in the energy region of the isovector giant dipole resonance. The E1 GSF is compared to parametrizations recommended by the RIPL-3 data base showing systematic deficiencies of all models in the energy region around neutron threshold. The new data for the poorly known s...
Energy Technology Data Exchange (ETDEWEB)
Vijarnsorn, Chodchanok [University of Alberta, Faculty of Medicine and Dentistry, Stollery Children' s Hospital, Edmonton, AB (Canada); Mahidol University, Siriraj Hospital, Bangkok (Thailand); Myers, Kimberley; Patton, David J. [Alberta Children' s Hospital, Section of Pediatric Cardiology, Department of Pediatrics, Department of Pediatrics, Calgary, AB (Canada); Noga, Michelle; Crawley, Cinzia; Tham, Edythe [University of Alberta, Faculty of Medicine and Dentistry, Stollery Children' s Hospital, Edmonton, AB (Canada)
2016-06-15
Standardized methods to evaluate atrial properties in single ventricles are lacking. To determine the feasibility of quantifying right atrial volumes and function in hypoplastic left heart using MRI. We studied 15 infants with hypoplastic left heart prior to Glenn surgery (mean age 4.2 months [standard deviation 0.3]) who underwent cardiac MRI with evaluation of atrial volumes and emptying fraction using monoplane two-chamber, monoplane four-chamber, and biplane methods, all of which were compared to the atrial short-axial oblique stack method. We compared atrial end-diastolic volume, end-systolic volume and emptying fraction among these methods. We analyzed reproducibility of the methods using Bland-Altman plots. Both four-chamber and biplane methods showed high correlations for atrial end-diastolic volume (r = 0.7 and r = 0.8, respectively; P < 0.01) and end-systolic volume (r = 0.8 and r = 0.9, respectively; P < 0.01) with small mean differences (-0.2 ± 2.9 standard deviation [SD] ml and -0.8 ± 1.6 ml, respectively, for atrial end-diastolic volume and -0.8 ± 1.5 ml and -0.9 ± 0.9 ml, respectively, for atrial end-systolic volume). The short-axial oblique method was the most reproducible, followed by the four-chamber method. MRI assessment of atrial volume and function is feasible in hypoplastic left heart and might provide further insight into single-ventricle mechanics. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Muto, Natalia Sayuri, E-mail: nataliamuto@gmail.com [Department of Radiology, Hokkaido University Hospital, N15 W7, kita-ku, Sapporo City, 0608638 (Japan); Kamishima, Tamotsu, E-mail: ktamotamo2@yahoo.co.jp [Department of Radiology, Hokkaido University Hospital, N15 W7, kita-ku, Sapporo City, 0608638 (Japan); Harris, Ardene A., E-mail: ardene_b@yahoo.com [Department of Radiology, Hokkaido University Hospital, N15 W7, kita-ku, Sapporo City, 0608638 (Japan); Kato, Fumi, E-mail: fumikato@med.hokudai.ac.jp [Department of Radiology, Hokkaido University Hospital, N15 W7, kita-ku, Sapporo City, 0608638 (Japan); Onodera, Yuya, E-mail: yuyaonodera@med.hokudai.ac.jp [Department of Radiology, Hokkaido University Hospital, N15 W7, kita-ku, Sapporo City, 0608638 (Japan); Terae, Satoshi, E-mail: saterae@yahoo.co.jp [Department of Radiology, Hokkaido University Hospital, N15 W7, kita-ku, Sapporo City, 0608638 (Japan); Shirato, Hiroki, E-mail: shirato@med.hokudai.ac.jp [Department of Radiology, Hokkaido University Hospital, N15 W7, kita-ku, Sapporo City, 0608638 (Japan)
2011-04-15
Purpose: To evaluate the relationship between renal cortical volume, measured by an automatic contouring software, with body mass index (BMI), age and renal function. Materials and methods: The study was performed in accordance to the institutional guidelines at our hospital. Sixty-four patients (34 men, 30 women), aged 19 to 79 years had their CT scans for diagnosis or follow-up of hepatocellular carcinoma retrospectively examined by a computer workstation using a software that automatically contours the renal cortex and the renal parenchyma. Body mass index and estimated glomerular filtration rate (eGFR) were calculated based on data collected. Statistical analysis was done using the Student t-test, multiple regression analysis, and intraclass correlation coefficient (ICC). Results: The ICC for total renal and renal cortical volumes were 0.98 and 0.99, respectively. Renal volume measurements yielded a mean cortical volume of 105.8 cm{sup 3} {+-} 28.4 SD, mean total volume of 153 cm{sup 3} {+-} 39 SD and mean medullary volume of 47.8 cm{sup 3} {+-} 19.5 SD. The correlation between body weight/height/BMI and both total renal and cortical volumes presented r = 0.6, 0.6 and 0.4, respectively, p < 0.05, while the correlation between renal cortex and age was r = -0.3, p < 0.05. eGFR showed correlation with renal cortical volume r = 0.6, p < 0.05. Conclusion: This study demonstrated that renal cortical volume had a moderate positive relationship with BMI, moderate negative relationship with age, and a strong positive relationship with the renal function, and provided a new method to routinely produce volumetric assessment of the kidney.
Institute of Scientific and Technical Information of China (English)
N. Ghahramany; M. Nouri
2003-01-01
Two structure functions W1(x,Q2) and W2(x,Q2) are determined by using the cross sections measured in the deep inelastic electron-proton scattering experiments at Stanford Linac in the energy range of 5 to 20 GeV. In this paper an alternative mathematical approach have been used in such determination, resulting in a larger number of points in the graphs of the structure functions.
Loginov, A Y
2002-01-01
Bethe-Salpeter equation for the massive particles with spin 1 is considered. The scattering amplitude decomposition of the particles with spin 1 by relativistic tensors is derived. The transformation coefficients from helicity amplitudes to invariant functions is found. The integral equations system for invariant functions is obtained and partial decomposition of this system is performed. Equivalent system of the integral equation for the partial helicity amplitudes is presented.
State of the Art in Transfer Functions for Direct Volume Rendering
Ljung, Patric
2016-07-04
A central topic in scientific visualization is the transfer function (TF) for volume rendering. The TF serves a fundamental role in translating scalar and multivariate data into color and opacity to express and reveal the relevant features present in the data studied. Beyond this core functionality, TFs also serve as a tool for encoding and utilizing domain knowledge and as an expression for visual design of material appearances. TFs also enable interactive volumetric exploration of complex data. The purpose of this state-of-the-art report (STAR) is to provide an overview of research into the various aspects of TFs, which lead to interpretation of the underlying data through the use of meaningful visual representations. The STAR classifies TF research into the following aspects: dimensionality, derived attributes, aggregated attributes, rendering aspects, automation, and user interfaces. The STAR concludes with some interesting research challenges that form the basis of an agenda for the development of next generation TF tools and methodologies. © 2016 The Author(s) Computer Graphics Forum © 2016 The Eurographics Association and John Wiley & Sons Ltd. Published by John Wiley & Sons Ltd.
Excluded volume effects in compressed polymer brushes: A density functional theory
Chen, Cangyi; Tang, Ping; Qiu, Feng; Shi, An-Chang
2015-03-01
A classical density functional theory (DFT) is applied to investigate the behavior of compressed polymer brushes composed of hard-sphere chains. The excluded volume interactions among the chain segments are explicitly treated. Two compression systems are used to study the behavior of brush-wall and brush-brush interactions. For the brush-brush systems, an obvious interpenetration zone has been observed. The extent of the interpenetration depends strongly on the grafting density. Furthermore, the repulsive force between the brush and wall or between the two brushes has been obtained as a function of the compression distance. Compared to the prediction of the analytic self-consistent field theory, such force increases more rapidly in the brush-wall compression with high polymer grafting densities or at higher compressions. In the brush-brush compression system, the interpenetration between the two compressed brushes creates a "softer" interaction. The influence of hard-sphere solvents on the behavior of compressed brushes is also discussed.
Scattering matrix theory for stochastic scalar fields.
Korotkova, Olga; Wolf, Emil
2007-05-01
We consider scattering of stochastic scalar fields on deterministic as well as on random media, occupying a finite domain. The scattering is characterized by a generalized scattering matrix which transforms the angular correlation function of the incident field into the angular correlation function of the scattered field. Within the accuracy of the first Born approximation this matrix can be expressed in a simple manner in terms of the scattering potential of the scatterer. Apart from determining the angular distribution of the spectral intensity of the scattered field, the scattering matrix makes it possible also to determine the changes in the state of coherence of the field produced on scattering.
Figueroa-Vinas, Adolfo; Gurgiolo, Chris A.; Nieves-Chinchilla, Teresa; Goldstein, Melvyn L.
2010-01-01
It has been suggested by a number of authors that the solar wind electron halo can be formed by the scattering of the strahl. On frequent occasions we have observed in electron angular skymaps (Phi/Theta-plots) of the electron 3D velocity distribution functions) a bursty-filament of particles connecting the strahl to the solar wind core-halo. These are seen over a very limited energy range. When the magnetic field is well off the nominal solar wind flow direction such filaments are inconsistent with any local forces and are probably the result of strong scattering. Furthermore, observations indicates that the strahl component is frequently and significantly anisotropic (Tper/Tpal approx.2). This provides a possible free energy source for the excitation of whistler waves as a possible scattering mechanism. The empirical observational evidence between the halo and the strahl suggests that the strahl population may be, at least in part, the source of the halo component.
Wall, M A; Olson, D; Bonn, B A; Creelman, T; Buist, A S
1982-02-01
Reference standards of lung function was determined in 176 healthy North American Indian children (94 girls, 82 boys) 7 to 18 yr of age. Spirometry, maximal expiratory flow volume curves, and peak expiratory flow rate were measured using techniques and equipment recommended by the American Thoracic Society. Standing height was found to be an accurate predictor of lung function, and prediction equations for each lung function variable are presented using standing height as the independent variable. Lung volumes and expiratory flow rates in North American Indian children were similar to those previously reported for white and Mexican-American children but were greater than those in black children. In both boys and girls, lung function increased in a curvilinear fashion. Volume-adjusted maximal expiratory flow rates after expiring 50 or 75% of FVC tended to decrease in both sexes as age and height increased. Our maximal expiratory flow volume curve data suggest that as North American Indian children grow, lung volume increases at a slightly faster rate than airway size does.
Institute of Scientific and Technical Information of China (English)
LIU Jin-ming; WU Wen; LI Xia; Jonson Bjorn; YANG Wen-lan; JIANG Ge-ning; DING Jia-an; ZHENG Wei; LIU Wen-zeng; WANG Ying-min; GAO Bei-lan; JIANG Ping
2007-01-01
Background Now lung volume reduction surgery (LVRS) has become one of the most effective methods for the management of some cases of severe chronic obstructive pulmonary disease (COPD). We evaluated the mid-term effects of LVRS on pulmonary function in patients with severe COPD.Methods Ten male patients with severe COPD aged 38-70 years underwent LVRS and their pulmonary function was assessed before, 3 months and 3 years after surgery. The spirometric and gas exchange parameters included residual volume, total lung capacity, inspiratory capacity, forced vital capacity, forced expiratory volume in one second, diffusion capacity for CO, and arterial blood gas. A 6-minute walk distance (6MWD) test was performed.Results As to preoperative assessment, most spirometric parameters and 6MWD were significantly improved after 3 months and slightly 3 years after LVRS. Gas exchange parameters were significantly improved 3 months after surgery,but returned to the preoperative levels after 3 years.Conclusions LVRS may significantly improve pulmonary function in patients with severe COPD indicating for LVRS.Mid-term pulmonary function 3 years after surgery can be decreased to the level at 3 months after surgery. Three years after LVRS, lung volume and pulmonary ventilation function can be significantly improved, but the improvement in gas exchange function was not significant.
Test functions for three-dimensional control-volume mixed finite-element methods on irregular grids
Naff, R.L.; Russell, T.F.; Wilson, J.D.; ,; ,; ,; ,; ,
2000-01-01
Numerical methods based on unstructured grids, with irregular cells, usually require discrete shape functions to approximate the distribution of quantities across cells. For control-volume mixed finite-element methods, vector shape functions are used to approximate the distribution of velocities across cells and vector test functions are used to minimize the error associated with the numerical approximation scheme. For a logically cubic mesh, the lowest-order shape functions are chosen in a natural way to conserve intercell fluxes that vary linearly in logical space. Vector test functions, while somewhat restricted by the mapping into the logical reference cube, admit a wider class of possibilities. Ideally, an error minimization procedure to select the test function from an acceptable class of candidates would be the best procedure. Lacking such a procedure, we first investigate the effect of possible test functions on the pressure distribution over the control volume; specifically, we look for test functions that allow for the elimination of intermediate pressures on cell faces. From these results, we select three forms for the test function for use in a control-volume mixed method code and subject them to an error analysis for different forms of grid irregularity; errors are reported in terms of the discrete L2 norm of the velocity error. Of these three forms, one appears to produce optimal results for most forms of grid irregularity.
Roth, B
2001-01-01
In this thesis the measurements of the relative differential cross section, the exchange asymmetry, the spin-orbit asymmetry, and the interference asymmetry for the electron scattering on cesium atoms from 4 to 18 eV is described. (HSI)
Directory of Open Access Journals (Sweden)
Yuan Sun
2016-04-01
Full Text Available Timber volume is an important ecological component in forested landscapes. The application of terrestrial laser scanning (TLS to volume estimation has been widely accepted though few species have well-calibrated taper functions. This research uses TLS technology in poplar (Populus × canadensis Moench cv. ‘I-72/58’ to extract stem diameter at different tree heights and establish the relationship between point cloud data and stem curve, which constitutes the basis for volume estimation of single trees and the stand. Eight plots were established and scanned by TLS. Stem curve functions were then fitted after extraction of diameters at different height, and tree heights from the point cloud data. Lastly, six functions were evaluated by R2 and RMSE. A modified Schumacher equation was the most suitable taper function. Volume estimates from the TLS-derived taper function were better than those derived using the stem-analysis data. Finally, regression analysis showed that predictions of stem size were similar when data were based on TLS versus stem analysis. Its high accuracy and efficiency indicates that TLS technology can play an important role in forest inventory assessment.
Scattering form factors for self-assembled network junctions
Foster, T.; Safran, S. A.; Sottmann, T.; Strey, R.
2007-11-01
The equilibrium microstructures in microemulsions and other self-assembled systems show complex, connected shapes such as symmetric bicontinuous spongelike structures and asymmetric bicontinuous networks formed by cylinders interconnected at junctions. In microemulsions, these cylinder network microstructures may mediate the structural transition from a spherical or globular phase to the bicontinuous microstructure. To understand the structural and statistical properties of such cylinder network microstructures as measured by scattering experiments, models are needed to extract the real-space structure from the scattering data. In this paper, we calculate the scattering functions appropriate for cylinder network microstructures. We focus on such networks that contain a high density of network junctions that connect the cylindrical elements. In this limit, the network microstructure can be regarded as an assembly of randomly oriented, closed packed network junctions (i.e., the cylinder scattering contributions are neglected). Accordingly, the scattering spectrum of the network microstructure can be calculated as the product of the junction number density, the junction form factor, which describes the scattering from the surface of a single junction, and a structure factor, which describes the local correlations of different junctions due to junction interactions (including their excluded volume). This approach is applied to analyze the scattering data from a bicontinuous microemulsion with equal volumes of water and oil. In a second approach, we included the cylinder scattering contribution in the junction form factor by calculating the scattering intensity of Y junctions to which three rods with spherical cross section are attached. The respective theoretical predictions are compared with results of neutron scattering measurements on a water-in-oil microemulsion with a connected microstructure.
Directory of Open Access Journals (Sweden)
AR Moaref1
2008-03-01
Full Text Available Background: Right ventricular apical (RVA pacing has been reported to induce several deleterious effects particularly in the presence of structural heart disease but can also involve patients with normal left ventricular (LV function. Left atrial (LA enlargement is one of these effects, but the majority of studies have measured LA dimension rather than volume.Objective: The present prospective study was designed to assess the effect of RVA pacing on LA volume in patients with normal LV function.Patients and Methods: The study comprised 41 consecutive patients with LV ejection fraction ≥ 45% and LV end diastolic dimension ≤ 56 mm who underwent single-or dual- chamber pacemaker implantation in RVA and followed for LA volume measurement and pacemaker analysis at least during the ensuing 4.2 months. Results: In all, 21 patients were excluded from the study due to five spontaneous wide QRS complex (≥120msec, one recent acute coronary syndrome,one significant valvular heart disease, three pacing frequency <90%, eight death or losing follow up in three cases. In remaining 20 patients, LA volume ragned from 21 to 54 mm3 with mean of 37.3±9.7 mm3 prior to pacemaker implantation that increased to 31 to 103 mm3 (54.3±17.0 during follow-up (P<0.001.Conclusion: RVA pacing might lead to an increase in LA volume even in patients with normal LV function.
Kryvi, J. B.; Simonsen, I.; Maradudin, A. A.
2016-09-01
The contribution to the mean differential reflection coefficient from the in-plane, co-polarized scattering of p- polarized light from a two-dimensional randomly rough dielectric surface is used to invert scattering data to obtain the normalized surface height autocorrelation function of the surface. Within phase perturbation theory this contribution to the mean differential reflection coefficient possesses singularities (poles) when the polar scattering angle θs equals +/-θB= +/- tan-1√E, where E is the dielectric constant of the dielectric medium and θB is the Brewster angle. Nevertheless, we show in this paper that if the mean differential reflection coefficient is measured only in the angular range |θs| inversion scheme. This approach also yields the rms height of the surface roughness, and the dielectric constant of the scattering medium if it is not known in advance. The input data used in this minimization procedure consist of computer simulation results for surfaces defined by exponential and Gaussian surface height correlation functions, without and with the addition of multiplicative noise. The proposed inversion scheme is computationally efficient.
Correlation of neurocognitive function and brain parenchyma volumes in children surviving cancer
Reddick, Wilburn E.; White, Holly A.; Glass, John O.; Mulhern, Raymond K.
2002-04-01
This research builds on our hypothesis that white matter damage and associated neurocognitive symptoms, in children treated for cancer with cranial spinal irradiation, spans a continuum of severity that can be reliably probed using non-invasive MR technology. Quantitative volumetric assessments of MR imaging and psychological assessments were obtained in 40 long-term survivors of malignant brain tumors treated with cranial irradiation. Neurocognitive assessments included a test of intellect (Wechsler Intelligence Test for Children, Wechsler Adult Intelligence Scale), attention (Conner's Continuous Performance Test), and memory (California Verbal Learning Test). One-sample t-tests were conducted to evaluate test performance of survivors against age-adjusted scores from the test norms; these analyses revealed significant impairments in all apriori selected measures of intelligence, attention, and memory. Partial correlation analyses were performed to assess the relationships between brain tissues volumes (normal appearing white matter (NAWM), gray matter, and CSF) and neurocognitive function. Global intelligence (r = 0.32, p = 0.05) and global attentional (r = 0.49, p childhood cancer treated with cranial irradiation reveal that loss of NAWM is associated with decreased intellectual and attentional deficits, whereas overall parenchyma loss, as reflected by increased CSF and decreased white matter, is associated with memory-related deficits.
Light Scattering Reviews, Vol 6 Light Scattering and Remote Sensing of Atmosphere and Surface
Kokhanovsky, Alexander A
2012-01-01
This is the next volume in series of Light Scattering Reviews. Volumes 1-5 have already been printed by Springer. The volume is composed of several papers ( usually, 10) of leading researchers in the respective field. The main focus of this book is light scattering, radiative transfer and optics of snow.
Energy Technology Data Exchange (ETDEWEB)
Schantz, Daryl I. [The Hospital for Sick Children, The Labatt Family Heart Centre in the Department of Paediatrics, Toronto, ON (Canada); University of Manitoba, Variety Children' s Heart Centre, Winnipeg, MB (Canada); Dragulescu, Andreea [The Hospital for Sick Children, The Labatt Family Heart Centre in the Department of Paediatrics, Toronto, ON (Canada); Memauri, Brett [University of Manitoba, Department of Radiology, St. Boniface General Hospital, Winnipeg, MB (Canada); Grotenhuis, Heynric B. [The Hospital for Sick Children, The Labatt Family Heart Centre in the Department of Paediatrics, Toronto, ON (Canada); Wilhelmina Children' s Hospital, Utrecht (Netherlands); Seed, Mike; Grosse-Wortmann, Lars [The Hospital for Sick Children, The Labatt Family Heart Centre in the Department of Paediatrics, Toronto, ON (Canada); The Hospital for Sick Children, Department of Diagnostic Imaging, Toronto, ON (Canada)
2016-10-15
Assessment of cardiac chamber volumes is a fundamental part of cardiac magnetic resonance (CMR) imaging. While the effects of inter- and intraobserver variability have been studied and have a recognized effect on the comparability of serial cardiac MR imaging studies, the effect of differences in hydration status has not been evaluated. To evaluate the effects of volume administration on cardiac chamber volumes. Thirteen healthy adults underwent a baseline cardiac MR to evaluate cardiac chamber volumes after an overnight fast. They were then given two saline boluses of 10 ml/kg of body weight and the cardiac MR was repeated immediately after each bolus. From the baseline scan to the final scan there was a significant increase in all four cardiac chamber end-diastolic volumes. Right atrial volumes increased 8.0%, from 61.1 to 66.0 ml/m2 (P<0.001), and left atrial volumes increased 10.0%, from 50.0 to 55.0 ml/m2 (P<0.001). Right ventricular volumes increased 6.0%, from 91.1 to 96.5 ml/m2 (P<0.001), and left ventricular volumes increased 3.2%, from 87.0 to 89.8 ml/m2 (P<0.001). Hydration status has a significant effect on the end-diastolic volumes of all cardiac chambers assessed by cardiac MR. Thus, hydration represents a ''variable'' that should be taken into account when assessing cardiac chamber volumes, especially when performing serial imaging studies in a patient. (orig.)
High frequency and pulse scattering physical acoustics
Pierce, Allan D
1992-01-01
High Frequency and Pulse Scattering investigates high frequency and pulse scattering, with emphasis on the phenomenon of echoes from objects. Geometrical and catastrophe optics methods in scattering are discussed, along with the scattering of sound pulses and the ringing of target resonances. Caustics and associated diffraction catastrophes are also examined.Comprised of two chapters, this volume begins with a detailed account of geometrically based approximation methods in scattering theory, focusing on waves transmitted through fluid and elastic scatterers and glory scattering; surface ray r
Energy Technology Data Exchange (ETDEWEB)
Kostorz, G. [Eidgenoessische Technische Hochschule, Angewandte Physik, Zurich (Switzerland)
1996-12-31
While Bragg scattering is characteristic for the average structure of crystals, static local deviations from the average lattice lead to diffuse elastic scattering around and between Bragg peaks. This scattering thus contains information on the occupation of lattice sites by different atomic species and on static local displacements, even in a macroscopically homogeneous crystalline sample. The various diffuse scattering effects, including those around the incident beam (small-angle scattering), are introduced and illustrated by typical results obtained for some Ni alloys. (author) 7 figs., 41 refs.
1991-01-01
Research Office * Banca Toscana Under the Auspices of - Italian Commission of Optics-ClO - European Optical Society - EOS - European Physical Society...invoke the central -limit theorem and claim that the sum of the scattered fields is a circular-Gaussian random variable. This implies that the received...factors from all of the eddies along the path. Therefore, if we assume that many such eddies exist, we can invoke the central -limit theorem to claim
Itopride for gastric volume,gastric emptying and drinking capacity in functional dyspepsia
Institute of Scientific and Technical Information of China (English)
Shahab; Abid; Wasim; Jafri; Maseeh; Uz; Zaman; Rakhshanda; Bilal; Safia; Awan; Aamir; Abbas
2017-01-01
AIM To study the effect of itopride on gastric accommodation, gastric emptying and drinking capacity in functional dyspepsia（FD）. METHODS Randomized controlled trial was conducted to check the effect of itopride on gastric accommodation, gastric emptying, capacity of tolerating nutrient liquid and symptoms of FD. We recruited a total of 31 patients having FD on the basis of ROME III criteria. After randomization, itopride was received by 15 patients while 16 patients received placebo. Gastric accommodation was determined using Gastric Scintigraphy. 13 C labeled octanoic breadth test was performed to assess gastric emptying. Capacity of tolerating nutrient liquid drink was checked using satiety drinking capacity test. Theintervention group comprised of 150 mg itopride. Patients in both arms were followed for 4 wk. RESULTS Mean age of the recruited participant 33 years（SD = 7.6） and most of the recruited individuals, i.e., 21（67.7%） were males. We found that there was no effect of itopride on gastric accommodation as measured at different in volumes in the itopride and control group with the empty stomach（P = 0.14）, at 20 min（P = 0.38）, 30 min（P = 0.30）, 40 min（P = 0.43）, 50 min（P = 0.50）, 60 min（P = 0.81）, 90 min（P = 0.25） and 120 min（P = 0.67）. Gastric emptying done on a sub sample（n = 11） showed no significant difference（P = 0.58） between itopride and placebo group. There was no significant improvement in the capacity to tolerate liquid in the itopride group as compared to placebo（P = 0.51）. Similarly there was no significant improvement of symptoms as assessed through a composite symptom score（P = 0.74）. The change in QT interval in itopride group was not significantly different from placebo（0.10）. CONCLUSION Our study found no effect of itopride on gastric accommodation, gastric emptying and maximum tolerated volume in patients with FD.
DEFF Research Database (Denmark)
Prescott, E; Netterstrøm, B; Faber, J
1992-01-01
It has previously been shown that long-term oral exposure to cobalt can cause goiter and myxedema. The effect of industrial cobalt exposure on thyroid volume and function was determined for 61 female plate painters exposed to cobalt blue dyes in two Danish porcelain factories and 48 unexposed ref...
DEFF Research Database (Denmark)
Kühl, J Tobias; Lønborg, Jacob; Fuchs, Andreas
2012-01-01
dynamic LA volume changes. Conversely, cardiac magnetic resonance imaging (CMR) and multi-slice computed tomography (MSCT) appears more appropriate for such measures. We sought to determine the relationship between LA size assessed with TTE and LA size and function assessed with CMR and MSCT. Fifty...
Institute of Scientific and Technical Information of China (English)
HAN Jian-Long; WU He-Yu; LI Zhi-Chang; LU Xiu-Qin; ZHAO Kui; ZHOU Ping; LIU Jian-Cheng; XU Guo-Ji; Sergey Yu Kun; WANG Qi; BAI Zhen; DONG Yu-Chuan; LI Song-Lin; DUAN Li-Min; XU Hu-Shan; XU Hua-Gen; CHEN Ruo-Fu
2008-01-01
@@ Excitation functions have been measured for different projectile-like fragments produced in 27 Al(19 F,x)y reactions at incident energies from 110.25 to 118. 75 Me V in 250 ke V steps. Strong cross section fluctuations of the excitation functions are observed. The cross-correlation coefficients of the excitation functions for different atomic number Z and for different scattering angle θcm have been deduced. These coefficients are much larger than the statistical theoretical calculated ones. This indicates that there are strong correlations between different exit channels in the dissipative heavy ion collision of 27 Al(19 F,x )y.
Functional Data Analysis in NTCP Modeling: A New Method to Explore the Radiation Dose-Volume Effects
Energy Technology Data Exchange (ETDEWEB)
Benadjaoud, Mohamed Amine, E-mail: mohamedamine.benadjaoud@gustaveroussy.fr [Center for Research in Epidemiology and Population Health (CESP) INSERM 1018 Radiation, Epidemiology Group, Villejuif (France); Université Paris sud, Le Kremlin-Bicêtre (France); Institut Gustave Roussy, Villejuif (France); Blanchard, Pierre [Université Paris sud, Le Kremlin-Bicêtre (France); Department of Radiation Oncology, Institut Gustave Roussy, Villejuif (France); Schwartz, Boris [Center for Research in Epidemiology and Population Health (CESP) INSERM 1018 Radiation, Epidemiology Group, Villejuif (France); Université Paris sud, Le Kremlin-Bicêtre (France); Institut Gustave Roussy, Villejuif (France); Champoudry, Jérôme [Department of Radiation Oncology, CHU de la Timone, Marseille (France); Bouaita, Ryan [Department of Radiation Oncology, CHU Henri Mondor, Creteil (France); Lefkopoulos, Dimitri [Department of Radiation Physics, Institut Gustave Roussy, Villejuif (France); Deutsch, Eric [Université Paris sud, Le Kremlin-Bicêtre (France); Department of Radiation Oncology, Institut Gustave Roussy, Villejuif (France); INSERM 1030, Molecular Radiotherapy, Villejuif (France); Diallo, Ibrahima [Center for Research in Epidemiology and Population Health (CESP) INSERM 1018 Radiation, Epidemiology Group, Villejuif (France); Université Paris sud, Le Kremlin-Bicêtre (France); Institut Gustave Roussy, Villejuif (France); Cardot, Hervé [Institut de Mathématiques de Bourgogne, Université de Bourgogne, Dijon (France); and others
2014-11-01
Purpose/Objective(s): To describe a novel method to explore radiation dose-volume effects. Functional data analysis is used to investigate the information contained in differential dose-volume histograms. The method is applied to the normal tissue complication probability modeling of rectal bleeding (RB) for patients irradiated in the prostatic bed by 3-dimensional conformal radiation therapy. Methods and Materials: Kernel density estimation was used to estimate the individual probability density functions from each of the 141 rectum differential dose-volume histograms. Functional principal component analysis was performed on the estimated probability density functions to explore the variation modes in the dose distribution. The functional principal components were then tested for association with RB using logistic regression adapted to functional covariates (FLR). For comparison, 3 other normal tissue complication probability models were considered: the Lyman-Kutcher-Burman model, logistic model based on standard dosimetric parameters (LM), and logistic model based on multivariate principal component analysis (PCA). Results: The incidence rate of grade ≥2 RB was 14%. V{sub 65Gy} was the most predictive factor for the LM (P=.058). The best fit for the Lyman-Kutcher-Burman model was obtained with n=0.12, m = 0.17, and TD50 = 72.6 Gy. In PCA and FLR, the components that describe the interdependence between the relative volumes exposed at intermediate and high doses were the most correlated to the complication. The FLR parameter function leads to a better understanding of the volume effect by including the treatment specificity in the delivered mechanistic information. For RB grade ≥2, patients with advanced age are significantly at risk (odds ratio, 1.123; 95% confidence interval, 1.03-1.22), and the fits of the LM, PCA, and functional principal component analysis models are significantly improved by including this clinical factor. Conclusion: Functional
Tkachenko, S; Kuhn, S E; Zhang, J; Arrington, J; Bosted, P; Bültmann, S; Christy, M E; Fenker, H; Griffioen, K A; Kalantarians, N; Keppel, C E; Melnitchouk, W; Tvaskis, V; Adhikari, K P; Aghasyan, M; Amaryan, M J; Pereira, S Anefalos; Avakian, H; Ball, J; Baltzell, N A; Battaglieri, M; Bedlinskiy, I; Biselli, A S; Briscoe, W J; Brooks, W K; Burkert, V D; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Cole, P L; Contalbrigo, M; Cortes, O; Crede, V; D'Angelo, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Dodge, G E; Doughty, D; Dupre, R; Egiyan, H; Alaoui, A El; Fassi, L El; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fleming, J A; Garillon, B; Gevorgyan, N; Ghandilyan, Y; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Golovatch, E; Gothe, R W; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Harrison, N; Hattawy, M; Hicks, K; Ho, D; Holtrop, M; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Jo, H S; Keller, D; Khandaker, M; Kim, A; Kim, W; Klein, A; Klein, F J; Koirala, S; Kubarovsky, V; Kuleshov, S V; Lenisa, P; Lewis, S; Livingston, K; Lu, H; MacCormick, M; MacGregor, I J D; Markov, N; Mayer, M; McKinnon, B; Mineeva, T; Mirazita, M; Mokeev, V; Montgomery, R A; Moutarde, H; Camacho, C Munoz; Nadel-Turonski, P; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Pappalardo, L L; Paremuzyan, R; Park, K; Pasyuk, E; Phillips, J J; Pisano, S; Pogorelko, O; Pozdniakov, S; Price, J W; Procureur, S; Protopopescu, D; Puckett, A J R; Rimal, D; Ripani, M; Rizzo, A; Rosner, G; Rossi, P; Roy, P; Sabatié, F; Schott, D; Schumacher, R A; Seder, E; Senderovich, I; Sharabian, Y G; Simonyan, A; Smith, G D; Sober, D I; Sokhan, D; Stepanyan, S; Stepanyan, S S; Strauch, S; Tang, W; Ungaro, M; Vlassov, A V; Voskanyan, H; Voutier, E; Walford, N K; Watts, D; Wei, X; Weinstein, L B; Wood, M H; Zana, L; Zonta, I
2014-01-01
Much less is known about neutron structure than that of the proton due to the absence of free neutron targets. Neutron information is usually extracted from data on nuclear targets such as deuterium, requiring corrections for nuclear binding and nucleon off-shell effects. These corrections are model dependent and have significant uncertainties, especially for large values of the Bjorken scaling variable x. The Barely Off-shell Nucleon Structure (BONuS) experiment at Jefferson Lab measured the inelastic electron deuteron scattering cross section, tagging spectator protons in coincidence with the scattered electrons. This method reduces nuclear binding uncertainties significantly and has allowed for the first time a (nearly) model independent extraction of the neutron structure function. A novel compact radial time projection chamber was built to detect protons with momentum between 70 and 150 MeV/c. For the extraction of the free neutron structure function $F_{2n}$, spectator protons at backward angle and with...
Directory of Open Access Journals (Sweden)
P. Gautam
2014-01-01
Full Text Available Prenatal alcohol exposure can cause a wide range of deficits in executive function that persist throughout life, but little is known about how changes in brain structure relate to cognition in affected individuals. In the current study, we predicted that the rate of white matter volumetric development would be atypical in children with fetal alcohol spectrum disorders (FASD when compared to typically developing children, and that the rate of change in cognitive function would relate to differential white matter development between groups. Data were available for 103 subjects [49 with FASD, 54 controls, age range 6–17, mean age = 11.83] with 153 total observations. Groups were age-matched. Participants underwent structural magnetic resonance imaging (MRI and an executive function (EF battery. Using white matter volumes measured bilaterally for frontal and parietal regions and the corpus callosum, change was predicted by modeling the effects of age, intracranial volume, sex, and interactions with exposure status and EF measures. While both groups showed regional increases in white matter volumes and improvement in cognitive performance over time, there were significant effects of exposure status on age-related relationships between white matter increases and EF measures. Specifically, individuals with FASD consistently showed a positive relationship between improved cognitive function and increased white matter volume over time, while no such relationships were seen in controls. These novel results relating improved cognitive function with increased white matter volume in FASD suggest that better cognitive outcomes could be possible for FASD subjects through interventions that enhance white matter plasticity.
Ma, Li; Gao, Pei-yi; Hu, Qing-mao; Lin, Yan; Jing, Li-na; Xue, Jing; Chen, Zhi-jun; Wang, Yong-jun; Liu, Mei-li; Cai, Ye-feng
2011-06-01
We explored the relationship between predicted infarct core, predicted ischemic penumbras and predicted final infarct volumes obtained though apparent diffusion coefficient (ADC)-based method, as well as other clinical variables, and functional outcome. Patients with acute cerebral ischemic stroke were retrospectively recruited. The National Institutes of Health Stroke Scale score was evaluated at baseline and the modified Rankin Scale (mRS) at day 90. Favorable outcome was defined as an mRS score of 0 to 2, and unfavorable outcome as 3 to 6. Multimodal stroke magnetic resonance imaging was carried out at presentation. The volumes of diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) were measured using the regions of interest (ROI) method. The volumes of predicted infarct core, predicted ischemic penumbra and predicted final infarct were obtained by an automated image analysis system based on baseline ADC maps. The association between baseline magnetic resonance imaging volumes, baseline clinical variables, and functional outcome was statistically analyzed. The study included 30 males and 20 females (mean±SD age, 56±10 years). Baseline DWI, PWI and PWI-DWI mismatch volumes were not correlated with day-90 mRS (P>0.05). Predicted infarct core, predicted ischemic penumbra and predicted final infarct through ADC-based method were all correlated with day-90 mRS (PStroke Scale and recanalization also demonstrated a trend toward a favorable outcome. Receiver operating characteristic analysis showed that the area under the curve of predicted final infarct volume and recanalization were higher with statistical significance (PStroke Scale and recanalization may have effect on functional outcome in acute ischemic stroke.
Scattering behavior of Lunar Lake playa determined from parabola bidirectional reflectance data
Shepard, Michael K.; Arvidson, Raymond E.; Guinness, Edward A.; Deering, Donald W.
1991-01-01
Bidirectional reflectance data obtained with the Portable Apparatus for Rapid Acquisition of Bidirectional Observations of Land and Atmosphere instrument at Lunar Lake, Nevada, were analyzed to determine the scattering properties of playas. The data are approximated by a Lambertian function, except at high phase angles in the solar principal plane, where Fresnel reflectance appears to dominate. The data also depart slightly (15 percent) from a Lambertian function at high emission angles in all azimuthal planes. No published photometric model accounts for the observed data. It is hypothesized that the observed scattering behavior is the superposition of volume and surface (Fresnel) scattering mechanisms.
Energy Technology Data Exchange (ETDEWEB)
Miller, William; Liu, Jian; Miller, William H.
2008-03-15
The linearized approximation to the semiclassical initial value representation (LSC-IVR) is used to calculate time correlation functions relevant to the incoherent dynamic structure factor for inelastic neutron scattering from liquid para-hydrogen at 14 K. Various time correlations functions were used which, if evaluated exactly, would give identical results, but they do not because the LSC-IVR is approximate. Some of the correlation functions involve only linear operators, and others involve non-linear operators. The consistency of the results obtained with the various time correlation functions thus provides a useful test of the accuracy of the LSC-IVR approximation and its ability to treat correlation functions involving both linear and nonlinear operators in realistic anharmonic systems. The good agreement of the results obtained from different correlation functions, their excellent behavior in the spectral moment tests based on the exact moment constraints, and their semi-quantitative agreement with the inelastic neutron scattering experimental data all suggest that the LSC-IVR is indeed a good short-time approximation for quantum mechanical correlation functions.
Dukart, Juergen; Bertolino, Alessandro
2014-01-01
Both functional and also more recently resting state magnetic resonance imaging have become established tools to investigate functional brain networks. Most studies use these tools to compare different populations without controlling for potential differences in underlying brain structure which might affect the functional measurements of interest. Here, we adapt a simulation approach combined with evaluation of real resting state magnetic resonance imaging data to investigate the potential impact of partial volume effects on established functional and resting state magnetic resonance imaging analyses. We demonstrate that differences in the underlying structure lead to a significant increase in detected functional differences in both types of analyses. Largest increases in functional differences are observed for highest signal-to-noise ratios and when signal with the lowest amount of partial volume effects is compared to any other partial volume effect constellation. In real data, structural information explains about 25% of within-subject variance observed in degree centrality--an established resting state connectivity measurement. Controlling this measurement for structural information can substantially alter correlational maps obtained in group analyses. Our results question current approaches of evaluating these measurements in diseased population with known structural changes without controlling for potential differences in these measurements.
Chen, Jianhan
2010-09-14
The generalized Born (GB) theory is a prime choice for implicit treatment of solvent that provides a favorable balance between efficiency and accuracy for reliable simulation of protein conformational equilibria. In GB, the dielectric boundary is a key physical property that needs to be properly described. While it is widely accepted that the molecular surface (MS) should provide the most physical description, most existing GB models are based on van der Waals (vdW)-like surfaces for computational simplicity and efficiency. A simple and effective approximation to molecular volume is explored here using atom-centered dielectric functions within the context of a generalized Born model with simple switching (GBSW). The new model, termed GBSW/MS2, is as efficient as the original vdW-like-surface-based GBSW model, but is able to reproduce the Born radii calculated from the "exact" Poisson-Boltzmann theory with a correlation of 0.95. More importantly, examination of the potentials of mean force of hydrogen-bonding and charge-charge interactions demonstrates that GBSW/MS2 correctly captures the first desolvation peaks, a key signature of true MS. Physical parameters including atomic input radii and peptide backbone torsion were subsequently optimized on the basis of solvation free energies of model compounds, potentials of mean force of their interactions, and conformational equilibria of a set of helical and β-hairpin model peptides. The resulting GBSW/MS2 protein force field reasonably recapitulates the structures and stabilities of these model peptides. Several remaining limitations and possible future developments are also discussed.
Environment scattering in GADRAS.
Energy Technology Data Exchange (ETDEWEB)
Thoreson, Gregory G.; Mitchell, Dean J; Theisen, Lisa Anne; Harding, Lee T.
2013-09-01
Radiation transport calculations were performed to compute the angular tallies for scattered gamma-rays as a function of distance, height, and environment. Greens Functions were then used to encapsulate the results a reusable transformation function. The calculations represent the transport of photons throughout scattering surfaces that surround sources and detectors, such as the ground and walls. Utilization of these calculations in GADRAS (Gamma Detector Response and Analysis Software) enables accurate computation of environmental scattering for a variety of environments and source configurations. This capability, which agrees well with numerous experimental benchmark measurements, is now deployed with GADRAS Version 18.2 as the basis for the computation of scattered radiation.
Hurwitz, Barry E; Coryell, Virginia T; Parker, Meela; Martin, Pedro; Laperriere, Arthur; Klimas, Nancy G; Sfakianakis, George N; Bilsker, Martin S
2009-10-19
The study examined whether deficits in cardiac output and blood volume in a CFS (chronic fatigue syndrome) cohort were present and linked to illness severity and sedentary lifestyle. Follow-up analyses assessed whether differences in cardiac output levels between CFS and control groups were corrected by controlling for cardiac contractility and TBV (total blood volume). The 146 participants were subdivided into two CFS groups based on symptom severity data, severe (n=30) and non-severe (n=26), and two healthy non-CFS control groups based on physical activity, sedentary (n=58) and non-sedentary (n=32). Controls were matched to CFS participants using age, gender, ethnicity and body mass. Echocardiographic measures indicated that the severe CFS participants had 10.2% lower cardiac volume (i.e. stroke index and end-diastolic volume) and 25.1% lower contractility (velocity of circumferential shortening corrected by heart rate) than the control groups. Dual tag blood volume assessments indicated that the CFS groups had lower TBV, PV (plasma volume) and RBCV (red blood cell volume) than control groups. Of the CFS subjects with a TBV deficit (i.e. > or = 8% below ideal levels), the mean+/-S.D. percentage deficit in TBV, PV and RBCV were -15.4+/-4.0, -13.2+/-5.0 and -19.1+/-6.3% respectively. Lower cardiac volume levels in CFS were substantially corrected by controlling for prevailing TBV deficits, but were not affected by controlling for cardiac contractility levels. Analyses indicated that the TBV deficit explained 91-94% of the group differences in cardiac volume indices. Group differences in cardiac structure were offsetting and, hence, no differences emerged for left ventricular mass index. Therefore the findings indicate that lower cardiac volume levels, displayed primarily by subjects with severe CFS, were not linked to diminished cardiac contractility levels, but were probably a consequence of a co-morbid hypovolaemic condition. Further study is needed to address
γ strength function and level density of 208Pb from forward-angle proton scattering at 295 MeV
Bassauer, S.; von Neumann-Cosel, P.; Tamii, A.
2016-11-01
Background: γ strength functions (GSFs) and level densities (LDs) are essential ingredients of statistical nuclear reaction theory with many applications in astrophysics, reactor design, and waste transmutation. Purpose: The aim of the present work is a test of systematic parametrizations of the GSF recommended by the RIPL-3 database for the case of 208Pb. The upward GSF and LD in 208Pb are compared to γ decay data from an Oslo-type experiment to examine the validity of the Brink-Axel (BA) hypothesis. Methods: The E 1 and M1 parts of the total GSF are determined from high-resolution forward angle inelastic proton scattering data taken at 295 MeV at the Research Center for Nuclear Physics (RCNP), Osaka, Japan. The total LD in 208Pb is derived from the 1- LD extracted with a fluctuation analysis in the energy region of the isovector giant dipole resonance. Results: The E 1 GSF is compared to parametrizations recommended by the RIPL-3 database showing systematic deficiencies of all models in the energy region around neutron threshold. The new data for the poorly known spin-flip M 1 resonance call for a substantial revision of the model suggested in RIPL-3. The total GSF derived from the present data is larger in the PDR energy region than the Oslo data but the strong fluctuations due to the low LD resulting from the double shell closure of 208Pb prevent a conclusion on a possible violation of the BA hypothesis. Using the parameters suggested by RIPL-3 for a description of the LD in 208Pb with the back-shifted Fermi gas model, remarkable agreement between the two experiments spanning a wide excitation energy range is obtained. Conclusions: Systematic parametrizations of the E 1 and M 1 GSF parts need to be reconsidered at low excitation energies. The good agreement of the LD provides an independent confirmation of the approach underlying the decomposition of GSF and LD in Oslo-type experiments.
Inversion assuming weak scattering
DEFF Research Database (Denmark)
Xenaki, Angeliki; Gerstoft, Peter; Mosegaard, Klaus
2013-01-01
The study of weak scattering from inhomogeneous media or interface roughness has long been of interest in sonar applications. In an acoustic backscattering model of a stationary field of volume inhomogeneities, a stochastic description of the field is more useful than a deterministic description...... due to the complex nature of the field. A method based on linear inversion is employed to infer information about the statistical properties of the scattering field from the obtained cross-spectral matrix. A synthetic example based on an active high-frequency sonar demonstrates that the proposed...
DEFF Research Database (Denmark)
Zsigmond, G.; Manoshin, S.; Lieutenant, K.
2007-01-01
Handling of polarization became very important in simulations of neutron scattering. One of the very comprehensive and open-source neutron simulation package, VITESS, has been intensely involved in polarized neutron simulations. Several examples will be shown here. Another similar package NISP al...
Zhu, Shaobin; Ma, Ling; Wang, Shuo; Chen, Chaoxiang; Zhang, Wenqiang; Yang, Lingling; Hang, Wei; Nolan, John P; Wu, Lina; Yan, Xiaomei
2014-10-28
Ultrasensitive detection and characterization of single nanoparticles (nanoparticles represents the simplest and the most direct method for particle detection. However, the sixth-power dependence of scattering intensity on particle size renders very small particles indistinguishable from the background. Adopting strategies for single-molecule fluorescence detection in a sheathed flow, here we report the development of high sensitivity flow cytometry (HSFCM) that achieves real-time light-scattering detection of single silica and gold nanoparticles as small as 24 and 7 nm in diameter, respectively. This unprecedented sensitivity enables high-resolution sizing of single nanoparticles directly based on their scattered intensity. With a resolution comparable to that of TEM and the ease and speed of flow cytometric analysis, HSFCM is particularly suitable for nanoparticle size distribution analysis of polydisperse/heterogeneous/mixed samples. Through concurrent fluorescence detection, simultaneous insights into the size and payload variations of engineered nanoparticles are demonstrated with two forms of clinical nanomedicine. By offering quantitative multiparameter analysis of single nanoparticles in liquid suspensions at a throughput of up to 10 000 particles per minute, HSFCM represents a major advance both in light-scattering detection technology and in nanoparticle characterization.
Elastic modulus of Al-Si/SiC metal matrix composites as a function of volume fraction
Energy Technology Data Exchange (ETDEWEB)
Santhosh Kumar, S; Rajasekharan, T [Powder Metallurgy Group, Defence Metallurgical Research Laboratory, Kanchanbagh PO, Hyderabad-500 058 (India); Seshu Bai, V [School of Physics, University of Hyderabad, Central University PO, Hyderabad-500 046 (India); Rajkumar, K V; Sharma, G K; Jayakumar, T, E-mail: dearsanthosh@gmail.co [Non-Destructive Evaluation Division, Indira Gandhi Center for Atomic Research, Kalpakkam, Chennai-603 102 (India)
2009-09-07
Aluminum alloy matrix composites have emerged as candidate materials for electronic packaging applications in the field of aerospace semiconductor electronics. Composites prepared by the pressureless infiltration technique with high volume fractions in the range 0.41-0.70 were studied using ultrasonic velocity measurements. For different volume fractions of SiC, the longitudinal velocity and shear velocity were found to be in the range of 7600-9300 m s{sup -1} and 4400-5500 m s{sup -1}, respectively. The elastic moduli of the composites were determined from ultrasonic velocities and were analysed as a function of the volume fraction of the reinforcement. The observed variation is discussed in the context of existing theoretical models for the effective elastic moduli of two-phase systems.
Stover, John C.
1991-12-01
Optical scatter is a bothersome source of optical noise, limits resolution and reduces system throughput. However, it is also an extremely sensitive metrology tool. It is employed in a wide variety of applications in the optics industry (where direct scatter measurement is of concern) and is becoming a popular indirect measurement in other industries where its measurement in some form is an indicator of another component property - like roughness, contamination or position. This paper presents a brief review of the current state of this technology as it emerges from university and government laboratories into more general industry use. The bidirectional scatter distribution function (or BSDF) has become the common format for expressing scatter data and is now used almost universally. Measurements made at dozens of laboratories around the country cover the spectrum from the uv to the mid- IR. Data analysis of optical component scatter has progressed to the point where a variety of analysis tools are becoming available for discriminating between the various sources of scatter. Work has progressed on the analysis of rough surface scatter and the application of these techniques to some challenging problems outside the optical industry. Scatter metrology is acquiring standards and formal test procedures. The available scatter data base is rapidly expanding as the number and sophistication of measurement facilities increases. Scatter from contaminants is continuing to be a major area of work as scatterometers appear in vacuum chambers at various laboratories across the country. Another area of research driven by space applications is understanding the non-topographic sources of mid-IR scatter that are associated with Beryllium and other materials. The current flurry of work in this growing area of metrology can be expected to continue for several more years and to further expand to applications in other industries.
Institute of Scientific and Technical Information of China (English)
Serena Morigi; Fiorella Sgallari
2009-01-01
This paper introduces the use of partition of unity method for the develop-ment of a high order finite volume discretization scheme on unstructured grids for solv-ing diffusion models based on partial differential equations. The unknown function and its gradient can be accurately reconstructed using high order optimal recovery based on radial basis functions. The methodology proposed is applied to the noise removal prob-lem in functional surfaces and images. Numerical results demonstrate the effectiveness of the new numerical approach and provide experimental order of convergence.
Energy Technology Data Exchange (ETDEWEB)
Price, A., E-mail: A.C.PRICE.625036@swansea.ac.uk; Martinez, A. [College of Engineering, Swansea University, Swansea (United Kingdom)
2015-04-28
Using quantum transport simulations, the impact of electron-phonon scattering on the transfer characteristic of a gate-all-around nanowire (GaAs) field effect transistor (NWFET) has been thoroughly investigated. The Non-Equilibrium Green's Function formalism in the effective mass approximation using a decoupled mode decomposition has been deployed. NWFETs of different dimensions have been considered, and scattering mechanisms including acoustic, optical and polar optical phonons have been included. The effective masses were extracted from tight binding simulations. High and low drain bias have been considered. We found substantial source to drain tunnelling current and significant impact of phonon scattering on the performance of the NWFET. At low drain bias, for a 2.2 × 2.2 nm{sup 2} cross-section transistor, scattering caused a 72%, 77%, and 81% decrease in the on-current for a 6 nm, 10 nm, and 20 nm channel length, respectively. This reduction in the current due to scattering is influenced by the increase in the tunnelling current. We include the percentage tunnelling for each valley at low and high drain bias. It was also found that the strong quantisation caused the relative position of the valleys to vary with the cross-section. This had a large effect on the overall tunnelling current. The phonon-limited mobility was also calculated, finding a mobility of 950 cm{sup 2}/V s at an inversion charge density of 10{sup 12 }cm{sup −2} for a 4.2 × 4.2 nm{sup 2} cross-section device.
Withofs, Nadia; Bernard, Claire; Van der Rest, Catherine; Martinive, Philippe; Hatt, Mathieu; Jodogne, Sebastien; Visvikis, Dimitris; Lee, John A; Coucke, Philippe A; Hustinx, Roland
2014-09-08
PET/CT imaging could improve delineation of rectal carcinoma gross tumor volume (GTV) and reduce interobserver variability. The objective of this work was to compare various functional volume delineation algorithms. We enrolled 31 consecutive patients with locally advanced rectal carcinoma. The FDG PET/CT and the high dose CT (CTRT) were performed in the radiation treatment position. For each patient, the anatomical GTVRT was delineated based on the CTRT and compared to six different functional/metabolic GTVPET derived from two automatic segmentation approaches (FLAB and a gradient-based method); a relative threshold (45% of the SUVmax) and an absolute threshold (SUV > 2.5), using two different commercially available software (Philips EBW4 and Segami OASIS). The spatial sizes and shapes of all volumes were compared using the conformity index (CI). All the delineated metabolic tumor volumes (MTVs) were significantly different. The MTVs were as follows (mean ± SD): GTVRT (40.6 ± 31.28ml); FLAB (21.36± 16.34 ml); the gradient-based method (18.97± 16.83ml); OASIS 45% (15.89 ± 12.68 ml); Philips 45% (14.52 ± 10.91 ml); OASIS 2.5 (41.6 2 ± 33.26 ml); Philips 2.5 (40 ± 31.27 ml). CI between these various volumes ranged from 0.40 to 0.90. The mean CI between the different MTVs and the GTVCT was algorithms and the software products. The manipulation of PET/CT images and MTVs, such as the DICOM transfer to the Radiation Oncology Department, induced additional volume variations.
Energy Technology Data Exchange (ETDEWEB)
Chalal, Mohand [Laboratoire d' Electronique Quantique, Faculte de Physique, USTHB Alger, 16111 Alger (Algeria); Ehrburger-Dolle, Francoise; Morfin, Isabelle [Laboratoire de Spectrometrie Physique, UMR 5588 CNRS/UJF, 38402 Saint Martin d' Heres (France); Armas, Maria-Rosa Aguilar de; Lopez, Maria-Luisa [Instituto de Ciencia y TecnologIa de PolImeros, CSIC and CIBER-BBN, 28006 Madrid (Spain); Bley, Francoise, E-mail: francoise.ehrburger-dolle@ujf-grenoble.f [Science et Ingenierie des Materiaux et Procedes, UMR 5266 CNRS/INPG/UJF, 38402 Saint Martin d' Heres (France)
2010-10-01
The structural modifications induced by changes in temperature are investigated by Small-Angle X-ray Scattering (SAXS) over a broad range of q-values (3.5x10{sup -2} - 12 nm{sup -1}) in cryogels based on N-isopropylacrylamide (NIPA) and/or 2-Hydroxyethyl methacrylate-L-Lactide-Dextran (HEMA-LLA-D) macromer. Various copolymeric cryogels of these two monomers are prepared by cryopolymerization yielding macroporous gels (cryogels). For the plain pNIPA cryogel, the SAXS curves obtained at each temperature are well fitted by a sum of four equations describing respectively the scattering resulting from the gel surface (power law), from the solid-like (Guinier equation) and liquid-like (Ornstein-Zernike equation) heterogeneities and from the chain-chain correlation yielding a broad peak (pseudo-Voigt equation) in the high-q domain. The temperature dependence of the parameters obtained from the fit is analyzed and discussed. It is shown that the existence of an isoscattering (or isosbestic) point observed in pNIPA gels and in some copolymers is related to features observed by Differential Scanning Calorimetry and swelling ratio measurements.
Directory of Open Access Journals (Sweden)
P. Guio
Full Text Available The plasma dispersion function and the reduced velocity distribution function are calculated numerically for any arbitrary velocity distribution function with cylindrical symmetry along the magnetic field. The electron velocity distribution is separated into two distributions representing the distribution of the ambient electrons and the suprathermal electrons. The velocity distribution function of the ambient electrons is modelled by a near-Maxwellian distribution function in presence of a temperature gradient and a potential electric field. The velocity distribution function of the suprathermal electrons is derived from a numerical model of the angular energy flux spectrum obtained by solving the transport equation of electrons. The numerical method used to calculate the plasma dispersion function and the reduced velocity distribution is described. The numerical code is used with simulated data to evaluate the Doppler frequency asymmetry between the up- and downshifted plasma lines of the incoherent-scatter plasma lines at different wave vectors. It is shown that the observed Doppler asymmetry is more dependent on deviation from the Maxwellian through the thermal part for high-frequency radars, while for low-frequency radars the Doppler asymmetry depends more on the presence of a suprathermal population. It is also seen that the full evaluation of the plasma dispersion function gives larger Doppler asymmetry than the heat flow approximation for Langmuir waves with phase velocity about three to six times the mean thermal velocity. For such waves the moment expansion of the dispersion function is not fully valid and the full calculation of the dispersion function is needed.
Key words. Non-Maxwellian electron velocity distribution · Incoherent scatter plasma lines · EISCAT · Dielectric response function
Directory of Open Access Journals (Sweden)
Shravya Keerthi G, Hari Krishna Bandi, Suresh M, Mallikarjuna Reddy N
2013-10-01
Full Text Available Objectives: we found only effects of at least a short term practice extended over a period of a few days to weeks of pranayama (alternate nostril breathing rather than acute effects of unilateral right nostril breathing (suryanadi pranayama. Keeping this in mind the present study was designed to test the hypothesis that 10 min. of right nostril breathing have any immediate effect on ventilatory volumes and capacities in healthy volunteers. Methodology: Forced vital capacity (FVC, Forced expiratory volume in the first second (FEV1, Forced expiratory volume percent (FEV1/FVC%, Peak expiratory flow rate (PEFR, Forced expiratory flow25-75% (FEF25-75%, Maximum voluntary ventilation (MVV, Slow vital capacity (SVC, Expiratory reserve volume (ERV, Inspiratory reserve volume (IRV and Tidal volume (TV were recorded before and after Surya Nadi Pranayama. Results & Conclusion: There was a significant increase in FVC (p<0.0001, FEV1 (p<0.0007, PEFR (p<0.0001, FEF25-75% (p<0.0001, MVV (p<0.0001, SVC (p<0.0001, ERV (0.0006, IRV (p<0.0001 and TV (0.0055 after suryanadi pranayama. The immediate effect of suryanadi pranayama practice showed alleviation of ventilatory capacities and volumes. Any practice that increases PEFR and FEF25–75% is expected to retard the development of COPD’s. The increase in PEFR, vital capacities and flow rates by suryanadi pranayama practice obviously offers an increment in respiratory efficiency and it can be advocated to the patients of early bronchitis and as a preventive measure for COPD.
Directory of Open Access Journals (Sweden)
Scott D. Packard
2003-07-01
Full Text Available In order to identify differences in functional activity, we compared the reactivity of glioma vasculature and the native cerebral vasculature to both dilate and constrict in response to altered PaCO2. Gliomas were generated by unilateral implantation of U87MGdEGFR human glioma tumor cells into the striatum of adult female athymic rats. Relative changes in total and microvascular cerebral blood volume were determined by steady state contrast agent-enhanced magnetic resonance imaging for transitions from normocarbia to hypercarbia and hypocarbia. Although hypercarbia induced a significant increase in both total and microvascular blood volume in normal brain and glioma, reactivity of glioma vasculature was significantly blunted in comparison to normal striatum; glioma total CBV increased by 0.6±0.1%/mm Hg CO2 whereas normal striatum increased by 1.5±0.2%/mm Hg CO2, (P < .0001, group t-test. Reactivity of microvascular blood volume was also significantly blunted. In contrast, hypocarbia decreased both total and microvascular blood volumes more in glioma than in normal striatum. These results indicate that cerebral blood vessels derived by tumor-directed angiogenesis do retain reactivity to CO2. Furthermore, reduced reactivity of tumor vessels to a single physiological perturbation, such as hypercarbia, should not be construed as a generalized reduction of functional activity of the tumor vascular bed.
Tanifuji, T; Wang, L
2014-01-01
Absorption and reduced scattering coefficients (μ(a) and μ'(s)) of adult heads have been noninvasively determined by time-resolved reflectance measurements. The finite difference time domain (FDTD) analysis was used to calculate time-resolved reflectance from realistic adult head models with brain grooves containing a non-scattering layer. In vivo time-resolved reflectances of human heads were measured by a system composed of a time-correlated single photon counter and a diode laser. By minimizing the objective functions that compare theoretical and experimental time resolved reflectances, μ(a) and μ'(s) of brain were determined. It became clear that time-resolved measurements have enough sensitivity to determine both μ(a) and μ'(s) for superficial tissues, gray matter and white matter, except μ(s) for white matter.
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Breinbjerg, Olav
2008-01-01
Two volume integral equation formulations for modelling magneto-dielectric objects are compared in terms of accuracy and computational efficiency. The first is the combined-field integral equation (CFVIE), in which the unknown quantities are both the electric and magnetic fields, while the second...... is the electric-field integral equation (EFVIE) with a single unknown quantity - the electric field. A resonant double-negative metamaterial spherical shell is analysed as an example....
DEFF Research Database (Denmark)
Kim, Oleksiy S.; Breinbjerg, Olav
2008-01-01
Two volume integral equation formulations for modelling magneto-dielectric objects are compared in terms of accuracy and computational efficiency. The first is the combined-field integral equation (CFVIE), in which the unknown quantities are both the electric and magnetic fields, while the second...... is the electric-field integral equation (EFVIE) with a single unknown quantity - the electric field. A resonant double-negative metamaterial spherical shell is analysed as an example....
One-point functions in finite volume/temperature: a case study
Szécsényi, I M; Watts, G M T
2013-01-01
We consider finite volume (or equivalently, finite temperature) expectation values of local operators in integrable quantum field theories using a combination of numerical and analytical approaches. It is shown that the truncated conformal space approach, when supplemented with a recently proposed renormalization group, can be sufficiently extended to the low-energy regime that it can be matched with high precision by the low-temperature expansion proposed by Leclair and Mussardo. Besides verifying the consistency of the two descriptions, their combination leads to an evaluation of expectation values which is valid to a very high precision for all volume/temperature scales. As a side result of the investigation, we also discuss some unexpected singularities in the framework recently proposed by Pozsgay and Tak\\'acs for the description of matrix elements of local operators in finite volume, and show that while some of these singularities are resolved by the inclusion of the class of exponential finite size cor...
Weatherford, C. A.; Brown, F. B.; Temkin, A.
1987-01-01
In a recent calculation, an exact exchange method was developed for use in the partial-differential-equation approach to electron-molecule scattering and was applied to e-N2 scattering in the fixed-nuclei approximation with an adiabatic polarization potential at low energies (0-10 eV). Integrated elastic cross sections were calculated and found to be lower than experiment at energies both below and above the Pi(g) resonance. It was speculated at that time that improved experimental agreement could be obtained if a correlated target representation were used in place of the uncorrelated one. The present paper implements this suggestion and demonstrates the improved agreement. These calculations are also extended to higher energies (0-30 eV) so asd to include the Sigma(u) resonance. Some discrepancies among the experiments and between experiment and the various calculations at very low energy are noted.
Vieira, H S
2016-01-01
We study the scattering and the resonant frequencies (quasispectrum) of charged massive scalar waves by Kerr-Newman-Kasuya spacetime (dyon black hole). The equations of motion are written into a Heun form, and its analytical solutions are obtained. We obtain the resonant frequencies expression and the general exact regular partial wave solution. The special cases of the Kerr and Schwarzschild black holes are analyzed and the solutions are shown.
Energy Technology Data Exchange (ETDEWEB)
Douslin, D.R.; Moore, R.T.; Waddington, G.
1959-11-01
Studies of the pressure-volume-temperature properties of perfluorocyclobutane, in the ranges 3-394 atm and 30-350/sup 0/, yielded values of gas compressibility, critical constants, vapor pressure and orthobaric liquid and vapor densities. The results were correlated by the Beattie Bridgeman, Benedict Webb Rubin, and Martin-Hou equations of state and by the Stockmayer and the Kihara intermolecular potential energy functions. The merits of the several correlational methods are discussed.
Small angle neutron scattering
Directory of Open Access Journals (Sweden)
Cousin Fabrice
2015-01-01
Full Text Available Small Angle Neutron Scattering (SANS is a technique that enables to probe the 3-D structure of materials on a typical size range lying from ∼ 1 nm up to ∼ a few 100 nm, the obtained information being statistically averaged on a sample whose volume is ∼ 1 cm3. This very rich technique enables to make a full structural characterization of a given object of nanometric dimensions (radius of gyration, shape, volume or mass, fractal dimension, specific area… through the determination of the form factor as well as the determination of the way objects are organized within in a continuous media, and therefore to describe interactions between them, through the determination of the structure factor. The specific properties of neutrons (possibility of tuning the scattering intensity by using the isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons make it particularly interesting in the fields of soft matter, biophysics, magnetic materials and metallurgy. In particular, the contrast variation methods allow to extract some informations that cannot be obtained by any other experimental techniques. This course is divided in two parts. The first one is devoted to the description of the principle of SANS: basics (formalism, coherent scattering/incoherent scattering, notion of elementary scatterer, form factor analysis (I(q→0, Guinier regime, intermediate regime, Porod regime, polydisperse system, structure factor analysis (2nd Virial coefficient, integral equations, characterization of aggregates, and contrast variation methods (how to create contrast in an homogeneous system, matching in ternary systems, extrapolation to zero concentration, Zero Averaged Contrast. It is illustrated by some representative examples. The second one describes the experimental aspects of SANS to guide user in its future experiments: description of SANS spectrometer, resolution of the spectrometer, optimization of
Sinkeler, Steef J; Damman, Kevin; van Veldhuisen, Dirk J; Hillege, Hans; Navis, Gerjan
2012-03-01
The association between cardiac failure and renal function impairment has gained wide recognition over the last decade. Both structural damage in the form of systemic atherosclerosis and (patho) physiological hemodynamic changes may explain this association. As regards hemodynamic factors, renal impairment in chronic heart failure is traditionally assumed to be mainly due to a decrease in cardiac output and a subsequent decrease in renal perfusion. This will lead to a decrease in glomerular filtration rate and a compensatory increase in tubular sodium retention. The latter is a physiological renal response aimed at retaining fluids in order to increase cardiac filling pressure and thus renal perfusion. In heart failure, however, larger increases in cardiac filling pressure are needed to restore renal perfusion and thus more volume retention. In this concept, in chronic heart failure, an equilibrium exists where a certain degree of congestion is the price to be paid to maintain adequate renal perfusion and function. Recently, this hypothesis was challenged by new studies, wherein it was found that the association between right-sided cardiac filling pressures and renal function is bimodal, with worse renal function at the highest filling pressures, reflecting a severely congested state. Renal hemodynamic studies suggest that congestion negatively affects renal function in particular in patients in whom renal perfusion is also compromised. Thus, an interplay between cardiac forward failure and backward failure is involved in the renal function impairment in the congestive state, presumably along with other factors. Only few data are available on the impact of intervention in volume status on the cardio-renal interaction. Sparse data in cardiac patients as well as evidence from cohorts with primary renal disease suggest that specific targeting of volume overload may be beneficial for long-term outcome, in spite of a certain further decrease in renal function, at least
One spatial dimensional finite volume three-body interaction for a short-range potential
Guo, Peng
2016-01-01
In this work, we use McGuire's model to describe scattering of three spinless identical particles in one spatial dimension, we first present analytic solutions of Faddeev's equation for scattering of three spinless particles in free space. The three particles interaction in finite volume is derived subsequently, and the quantization conditions by matching wave functions in free space and finite volume are presented in terms of two-body scattering phase shifts. The quantization conditions obtained in this work for short range interaction are L\\"uscher's formula like and consistent with Yang's results in \\cite{Yang:1967bm}.
DEFF Research Database (Denmark)
Kjølby, Birgitte Fuglsang; Mikkelsen, Irene Klærke; Pedersen, Michael
2009-01-01
perfusion metrics was investigated for the gradient echo pulse sequence at 1.5 T and 3.0 T. It is shown that the tissue contribution broadens and introduces fluctuations in the AIF. Furthermore, partial volume effects bias perfusion metrics in a nonlinear fashion, compromising quantitative perfusion...
Energy Technology Data Exchange (ETDEWEB)
Fukami, Tadanori [Department of Bio-system Engineering, Faculty of Engineering, Yamagata University, Yonezawa, Yamagata 992-8510 (Japan); Sato, Hidenori [Department of Bio-system Engineering, Faculty of Engineering, Yamagata University, Yonezawa, Yamagata 992-8510 (Japan); Wu, Jin [Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8575 (Japan); Lwin, Thet-Thet- [Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8575 (Japan); Yuasa, Tetsuya [Department of Bio-system Engineering, Faculty of Engineering, Yamagata University, Yonezawa, Yamagata 992-8510 (Japan); Kawano, Satoru [Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8575 (Japan); Iida, Keiji [Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8575 (Japan); Akatsuka, Takao [Department of Bio-system Engineering, Faculty of Engineering, Yamagata University, Yonezawa, Yamagata 992-8510 (Japan); Hontani, Hidekata [Department of Computer Science and Engineering, Nagoya Institute of Technology, Aichi 466-8555 (Japan); Takeda, Tohoru [Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8575 (Japan); Tamura, Masao [Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8575 (Japan); Yokota, Hiroshi [Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki 305-8575 (Japan)
2007-07-21
Our study aimed to quantitatively evaluate blood flow in the left ventricle (LV) of apical hypertrophic cardiomyopathy (APH) by combining wall thickness obtained from cardiac magnetic resonance imaging (MRI) and myocardial perfusion from single-photon emission computed tomography (SPECT). In this study, we considered paired MRI and myocardial perfusion SPECT from ten patients with APH and ten normals. Myocardial walls were detected using a level set method, and blood flow per unit myocardial volume was calculated using 3D surface-based registration between the MRI and SPECT images. We defined relative blood flow based on the maximum in the whole myocardial region. Accuracies of wall detection and registration were around 2.50 mm and 2.95 mm, respectively. We finally created a bull's-eye map to evaluate wall thickness, blood flow (cardiac perfusion) and blood flow per unit myocardial volume. In patients with APH, their wall thicknesses were over 10 mm. Decreased blood flow per unit myocardial volume was detected in the cardiac apex by calculation using wall thickness from MRI and blood flow from SPECT. The relative unit blood flow of the APH group was 1/7 times that of the normals in the apex. This normalization by myocardial volume distinguishes cases of APH whose SPECT images resemble the distributions of normal cases.
Energy Technology Data Exchange (ETDEWEB)
Yang, Fan; Xin, Le; Uzunoglu, Aytekin; Qiu, Yang; Stanciu, Lia; Ilavsky, Jan; Li, Wenzhen; Xie, Jian
2017-02-08
In making a catalyst ink, the interaction between Nafion ionomer and catalyst support are the key factors that directly affect both ionic conductivity and electronic conductivity of the catalyst layer in a membrane electrode assembly (MEA). One of the major aims of this investigation is to understand the behavior of the catalyst support, Vulcan XC-72 (XC-72) aggregates, in the existence of the Nafion ionomer in a catalyst ink to fill the knowledge gap of the interaction of these components. The dispersion of catalyst ink not only depends on the solvent, but also depends on the interaction of Nafion and carbon particles in the ink. The interaction of Nafion ionomer particles and XC-72 catalyst aggregates in liquid media was studied using ultra small angle x-ray scattering (USAXS) and cryogenic TEM techniques. Carbon black XC-72) and functionalized carbon black systems were introduced to study the interaction behaviors. A multiple curve fitting was used to extract the particle size and size distribution from scattering data. The results suggest that the particle size and size distribution of each system changed significantly in Nafion + XC-72 system, Nafion + NH2-XC72 system, and Nafion + SO3H-XC-72 system, which indicates that an interaction among these components (i.e. ionomer particles and XC-72 aggregates) exists. The cryogenic TEM, which allows for the observation the size of particles in a liquid, was used to validate the scattering results and shows excellent agreement.
1988-02-15
is the spectral density function which describes the frequency dependence of the scattering spectrum. If the electrons in the scattering volume are...stationary, no Doppler shift occurs and the spectral density function is 1 at (w=O (no frequency ,,diihit) and ;zero at all other frequencies. Of...electrons moving in a hot plasma. The spectral density function , which describes this Doppler- shifted spectrum, is very complicated and a description of it
Directory of Open Access Journals (Sweden)
R. Varela-Cives
2015-02-01
Full Text Available Purpose To evaluate the relationship between unilateral or bilateral criptorchidism, patient age, primary location of the gonad and modality of treatment with testicular volume and hormonal status at 18 years in patients diagnosed and treated for cryptorchidism during childhood. Materials and Methods Testicular volume, LH, FSH, and testosterone were evaluated in 143 young men at 18 years treated in childhood for unilateral (n=103 or bilateral (n=40 cryptorchidism. Results Unilateral cryptorchidism: Location of testis was prescrotal in 36 patients, inguinal in 52 and non-palpable in 15. The mean volume was 9.7 mL compared to 16.2 mL. for the spontaneously descended testicle in unilateral cryptorchidism. However, 22 patients who received HCG had a significantly bigger testis (11.8 mL. than those treated with primary surgery (9.2 mL. The results showed a significant positive correlation between testicular volume and patient age at treatment. Bilateral cryptorchidism Location of testis was prescrotal in 34 cases, inguinal in 40 and 6 patients with non-palpable testicles. Mean volume at 18 years was 12.9 mL, greater than unilateral cryptorchid testis (9.7 mL but smaller than healthy contralateral in unilateral cases (16.2 mL. There were significant differences in the testicular growth for bilateral patients with testicular descent after being treated with HCG (14.4 mL in respect with those untreated (11.1 mL or those who underwent primary surgery (11.4 mL. There was a significant positive correlation between the testicular volume and palpable (12.4 mL or non-palpable testis (10.4 mL. There was a correlation between unilateral or bilateral cryptorchidism and levels of FSH. Conclusions Testicular volume and hormonal function at 18 years for patients diagnosed and treated for cryptorchidism during childhood are strongly influenced by whether the undescended testis was unilateral or bilateral. Location of the testes at diagnosis or age of initial
Patterson, R P; Zhang, J; Mason, L I; Jerosch-Herold, M
2001-02-01
A study was conducted using the Sheffield electrical impedance tomography (EIT) portable system DAS-01 P to determine the change in the cardiac image with electrode position, lung volume and body position. Sixteen electrodes were positioned in three transverse planes around the thorax at the level of the second intercostal space, at the level of the xiphisternal joint, and midway between upper and lower locations. Data were collected at each electrode level with the breath held at end expiration and after inspiring 0.5, 1 and 1.5 l of air with the subject in both the supine and sitting position. These data were analysed using a Matlab developed program that calculates the average resistivity change in the cardiac region from automatically determined borders. Results show significant individual variability with electrode position and air volume. The middle electrode most consistently shows an increase in impedance in the region of the heart during systole. In some subjects the change in the ventricular-volume-like curve showed a greater than 50% change as a function of lung volume. The pattern of variability with electrode position was not consistent among subjects. In one subject MRI images were obtained to compare actual structures with those seen in the EIT image. The results suggest that using these electrode locations reliable and consistent data, which could be used in clinical applications, cannot be obtained.
Prescott, E; Netterstrøm, B; Faber, J; Hegedüs, L; Suadicani, P; Christensen, J M
1992-04-01
It has previously been shown that long-term oral exposure to cobalt can cause goiter and myxedema. The effect of industrial cobalt exposure on thyroid volume and function was determined for 61 female plate painters exposed to cobalt blue dyes in two Danish porcelain factories and 48 unexposed referents. Thyroid volume was determined by ultrasonography. The cobalt blue dyes were used in one of two forms, cobalt aluminate (insoluble) and cobalt-zinc silicate (semisoluble). Only the subjects exposed to semisoluble cobalt had a significantly increased urinary cobalt content (1.17 micrograms.mmol-1 versus 0.13 micrograms.mmol-1, P less than 0.0001). These subjects also had increased levels of serum thyroxine (T4) and free thyroxine (FT4I) (P = 0.0001 and 0.0029, respectively), unaltered serum thyroid stimulating hormone (TSH), and marginally reduced 3,5,3'-triiodothyronine (T3), whereas thyroid volume tended to be lower (P = 0.14). The group exposed to insoluble cobalt did not differ significantly in any thyroid-related parameters. No correlation between urinary cobalt and FT4I or thyroid volume was found. The study demonstrates an effect of cobalt on thyroid hormone metabolism.
DeMilo, Charles; Brukilacchio, Thomas; Soller, Babs R.; Soyemi, Olusola
2004-06-01
A visible-near IR (500-1,000nm) fiber optic sensor is under development that is intended to non-invasively assess muscle metabolism through the measurement of tissue pH and oxygen partial pressure. These parameters are calculated from the spectra of hemoglobin and myoglobin in muscle. The sensor consists of transmit (illumination) fibers and receive (detection) fibers that are coupled to a spectrometer. Light from the probe must penetrate below the surface of the skin and into a 5-10mm thick layer of muscle. A study was conducted to quantify the relationship between transmit and receive fiber separation and sensor penetration depth below the surface of the skin. A liquid phantom was created to replicate the absorption (μa) and reduced scatter coefficient (μs') profiles typically found in human blood and tissue. The phantom consisted of a solution of Intralipid and India ink in the appropriate concentrations to achieve desired reduced scatter coefficient and absorption profiles. The reduced scatter coefficient of the liquid phantom was achieved to an accuracy of +/-10% compared to previously published data. A fixed illumination fiber and translatable detector fiber were placed in the liquid phantom, and the fiber separation was varied from 3-40mm. Values of μa and μs' varied from 0.03-0.40 cm-1 and 5.0-15.0 cm-1 respectively. Results from the experiment demonstrate a strong correlation between penetration depth and fiber separation. Additionally, it was found that penetration depth was not substantially influenced by absorption and scatter concentration. As signal-to-noise is an important parameter in many non-invasive biomedical applications, the relative signal as a function of fiber separation was determined to follow an exponential relationship.
Shneerson, V L; Ourmazd, A; Saldin, D K
2008-03-01
It is demonstrated that a common-line method can assemble a three-dimensional oversampled diffracted intensity distribution suitable for high-resolution structure solution from a set of measured two-dimensional diffraction patterns, as proposed in experiments with an X-ray free-electron laser (XFEL) [Neutze et al. (2000). Nature (London), 406, 752-757]. Even for a flat Ewald sphere, it is shown how the ambiguities due to Friedel's law may be overcome. The method breaks down for photon counts below about 10 per detector pixel, almost three orders of magnitude higher than expected for scattering by a 500 kDa protein with an XFEL beam focused to a 0.1 microm diameter spot. Even if 10(3) orientationally similar diffraction patterns could be identified and added to reach the requisite photon count per pixel, the need for about 10(6) orientational classes for high-resolution structure determination suggests that about 10(9) diffraction patterns must be recorded. Assuming pulse and readout rates of approximately 100 Hz, such measurements would require approximately 10(7) s, i.e. several months of continuous beam time.
Energy Technology Data Exchange (ETDEWEB)
Buehring, W.
1983-03-01
Non-relativistic scattering phase shifts, bound state energies, and wave function normalization factors for a screened Coulomb potential of the Hulthen type are presented in the form of relatively simple analytic expressions. These formulae have been obtained by a suitable renormalization procedure applied to the quantities derived from an approximate Schroedinger equation which contains the exact Hulthen potential together with an approximate angular momentum term. When the screening exponent vanishes, our formulae reduce to the exact Coulomb expresions. The interrelation between our formulae and Pratt's analytic perturbation theory for screened Coulomb potentials' is discussed.
Cardona, Manuel
2007-01-01
This is the ninth volume of a well-established series in which expert practitioners discuss topical aspects of light scattering in solids. It reviews recent developments concerning mainly semiconductor nanostructures and inelastic x-ray scattering, including both coherent time-domain and spontaneous scattering studies. In the past few years, light scattering has become one of the most important research and characterization methods for studying carbon nanotubes and semiconducting quantum dots, and a crucial tool for exploring the coupled exciton--photon system in semiconductor cavities. Among the novel techniques discussed in this volume are pump--probe ultrafast measurements and those which use synchrotron radiation as light source. The book addresses improvements in the intensity, beam quality and time synchronization of modern synchrotron sources, which made it possible to measure the phonon dispersion in very small samples and to determine electronic energy bands as well as enabling real-time observations...
Perlich, Jan; Memesa, Mine; Diethert, Alexander; Metwalli, Ezzeldin; Wang, Weinan; Roth, Stephan V; Timmann, Andreas; Gutmann, Jochen S; Müller-Buschbaum, Peter
2009-03-23
Tailoring of the titania morphology is achieved by the combination of a triblock copolymer, acting as structure-directing agent, and a sol-gel chemistry enabling the incorporation of the provided inorganic material (titania) into the selected phase of the triblock copolymer. Spin-coating of the solution on FTO-coated glass, followed by plasma etching and calcination of the thin film results in the formation of self-encapsulated crystalline titania nanostructures. The fabricated nanostructures are coated stepwise with dye, conductive polymers and gold forming a functional multilayer stack. An advanced small-angle scattering technique probing the sample with X-ray synchrotron radiation under grazing incidence (GISAXS) is employed for the characterization of the preparation route, as scattering allows accessing the structure inside the multilayers. The tailored titania morphology is preserved during the preparation route towards the functional multilayer stack of a photovoltaic demonstration cell. Two clearly distinguishable structures originate from the substrate and the titania templated by the triblock copolymer; hence the other layers induce no additional structures. Therefore, this investigation provides the evidence that the effort spent to tailor the morphology is justified by the preservation of the self-encapsulated titania morphology that is created by the structure-directing agent throughout the functional multilayer stack build-up.
Energy Technology Data Exchange (ETDEWEB)
Choi, Don Kyoung; Choi, See Min; Jeong, Byong Chang; Seo, Seong Il; Jeon, Seong Soo; Lee, Hyun Moo; Choi, Han-Yong; Jeon, Hwang Gyun [Sungkyunkwan University School of Medicine, Department of Urology, Samsung Medical Center, Seoul (Korea, Republic of); Park, Bong Hee [The Catholic University of Korea College of Medicine, Department of Urology, Incheon St. Mary' s Hospital, Seoul (Korea, Republic of)
2015-11-15
We aimed to evaluate the performance of various GFR estimates compared with direct measurement of GFR (dGFR). We also sought to create a new formula for volume-based GFR (new-vGFR) using kidney volume determined by CT. GFR was measured using creatinine-based methods (MDRD, the Cockcroft-Gault equation, CKD-EPI formula, and the Mayo clinic formula) and the Herts method, which is volume-based (vGFR). We compared performance between GFR estimates and created a new vGFR model by multiple linear regression analysis. Among the creatinine-based GFR estimates, the MDRD and C-G equations were similarly associated with dGFR (correlation and concordance coefficients of 0.359 and 0.369 and 0.354 and 0.318, respectively). We developed the following new kidney volume-based GFR formula: 217.48-0.39XA + 0.25XW-0.46XH-54.01XsCr + 0.02XV-19.89 (if female) (A = age, W = weight, H = height, sCr = serum creatinine level, V = total kidney volume). The MDRD and CKD-EPI had relatively better accuracy than the other creatinine-based methods (30.7 % vs. 32.3 % within 10 % and 78.0 % vs. 73.0 % within 30 %, respectively). However, the new-vGFR formula had the most accurate results among all of the analyzed methods (37.4 % within 10 % and 84.6 % within 30 %). The new-vGFR can replace dGFR or creatinine-based GFR for assessing kidney function in donors and healthy individuals. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Stirling, W.G. [Liverpool Univ., Dep. of Physics, Liverpool (United Kingdom); Perry, S.C. [Keele Univ. (United Kingdom). Dept. of Physics
1996-12-31
We outline the theoretical and experimental background to neutron scattering studies of critical phenomena at magnetic and structural phase transitions. The displacive phase transition of SrTiO{sub 3} is discussed, along with examples from recent work on magnetic materials from the rare-earth (Ho, Dy) and actinide (NpAs, NpSb, USb) classes. The impact of synchrotron X-ray scattering is discussed in conclusion. (author) 13 figs., 18 refs.
Institute of Scientific and Technical Information of China (English)
Yi-Ming Li; Fan Lv; Xin Xu; Hong Ji; Wen-Tao Gao; Tuan-Jie Lei; Gui-Bing Ren; Zhi-Lan Bai; Qiang Li
2003-01-01
AIM: Our research attempted to evaluate the overall functional reserve of cirrhotic liver by combination of hepatic functional blood flow, liver volume, and ChildPugh′s classification, and to discuss its value of clinical application.METHODS: Ninety two patients with portal hypertension due to hepatic cirrhosis were investigated. All had a historyof haematemesis and hematochezia, esophageal and gastric fundus varices, splenomegaly and hypersplenia.A 2-year follow-up was routinely performed and no one was lost. Twenty two healthy volunteers were used as control group. Blood and urine samples were collected 4times before and after intravenous D-sorbitol infusion.The hepatic clearance (CLH) of D-sorbitol was then calculated according to enzymatic spectrophotometric method while the total blood flow (QToTAL) and intrahepatic shunt (RINs) were detected by multicolor Doppler ultrasound, and the liver volume was measured by spiral CT. Data were estimated by t-test, variance calculation and chi-squared test. The relationships between all these parameters and different groups were investigated according to Child-Pugh classification and postoperative complications respectively.RESULTS: Steady blood concentration was achieved 120 mins after D-sorbitol intravenous infusion, which was (0.358±0.064) mmoⅠ@L-1 in cirrhotic group and (0.189±0.05)mmol@L-1 in control group (P＜0.01). CLH=(812.7±112.4) ml@min-1,QTOTAL=(1280.6±131.4) ml@min-1, and RINS=(36.54±10.65)%in cirrhotic group and CLH=(1248.3±210.5) ml.min-1, QTOTAL=(1362.4-±126.9) ml@min-1, and RINS=(8.37±3.32) % in control group (P＜0.01). The liver volume of cirrhotic group was 1057±249 cm3, 851±148 cm3 and 663±77 cm3 in Child A, B and C group respectively with significant difference (P＜0.001).The average volume of cirrhotic liver in Child B, C group was significantly reduced in comparison with that in control group (P＜0.001). The patient, whose liver volume decreased by 40 % with the CLH below 600 ml
Margerin, Ludovic
2017-07-01
In this work, I propose to model the propagation of high-frequency seismic waves in the heterogeneous Earth by means of a coupled system of radiative transfer equations for P and S waves. The model describes the propagation of both coherent and diffuse waves in a statistically isotropic heterogeneous medium and takes into account key phenomena such as scattering conversions between propagation modes, scattering anisotropy and absorption. The main limitation of the approach lies in the neglect of the shear wave polarization information. The canonical case of a medium with uniform scattering and absorption properties is studied in details. Using an adjoint formalism, Green's functions (isotropic point source solutions) of the transport equation are shown to obey a reciprocity relation relating the P energy density radiated by an S source to the S energy density radiated by a P source. A spectral method of calculation of the Green's function is presented. Application of Fourier, Hankel and Legendre transforms to time, space and angular variables, respectively, turns the equation of transport into a numerically tractable penta-diagonal linear system of equations. The implementation of the spectral method is discussed in details and validated through one-to-one comparisons with Monte Carlo simulations. Numerical experiments in different propagation regimes illustrate that the ratio between the correlation length of heterogeneities and the incident wavelength plays a key role in the rate of stabilization of the P-to-S energy ratio in the coda. The results suggest that the rapid stabilization of energy ratios observed in the seismic coda is a signature of the broadband nature of crustal heterogeneities. The impact of the texture of the medium on both pulse broadening and generation of converted S wave arrivals by explosion sources is illustrated. The numerical study indicates that smooth media enhance the visibility of ballistic-like S arrivals from P sources.
Construction of Large-Volume Tissue Mimics with 3D Functional Vascular Networks
Kang, Tae-Yun; Hong, Jung Min; Jung, Jin Woo; Kang, Hyun-Wook; Cho, Dong-Woo
2016-01-01
We used indirect stereolithography (SL) to form inner-layered fluidic networks in a porous scaffold by introducing a hydrogel barrier on the luminal surface, then seeded the networks separately with human umbilical vein endothelial cells and human lung fibroblasts to form a tissue mimic containing vascular networks. The artificial vascular networks provided channels for oxygen transport, thus reducing the hypoxic volume and preventing cell death. The endothelium of the vascular networks significantly retarded the occlusion of channels during whole-blood circulation. The tissue mimics have the potential to be used as an in vitro platform to examine the physiologic and pathologic phenomena through vascular architecture. PMID:27228079
Construction of Large-Volume Tissue Mimics with 3D Functional Vascular Networks.
Directory of Open Access Journals (Sweden)
Tae-Yun Kang
Full Text Available We used indirect stereolithography (SL to form inner-layered fluidic networks in a porous scaffold by introducing a hydrogel barrier on the luminal surface, then seeded the networks separately with human umbilical vein endothelial cells and human lung fibroblasts to form a tissue mimic containing vascular networks. The artificial vascular networks provided channels for oxygen transport, thus reducing the hypoxic volume and preventing cell death. The endothelium of the vascular networks significantly retarded the occlusion of channels during whole-blood circulation. The tissue mimics have the potential to be used as an in vitro platform to examine the physiologic and pathologic phenomena through vascular architecture.
Energy Technology Data Exchange (ETDEWEB)
Mourant, Judith B.; Hielscher, Andreas H.; Eick, Angelica A.; Johnson, Tamara M. [Bioscience and Biotechnology Group, MS E535, Chemical Sciences and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Shen, Dan [Molecular and Cell Biology Group, MS M888, Life Sciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
1998-06-01
We have studied the optical properties of mammalian cell suspensions to provide a mechanistic basis for interpreting the optical properties of tissues {ital in vivo}. Measurements of the wavelength dependence of the reduced scattering coefficient and measurements of the phase function demonstrated that there is a distribution of scatterer sizes. The volumes of the scatterers are equivalent to those of spheres with diameters in the range between {approximately}0.4 and 2.0 {mu}m. Measurements of isolated organelles indicate that mitochondria and other similarly sized organelles are responsible for scattering at large angles, whereas nuclei are responsible for small-angle scattering. Therefore optical diagnostics are expected to be sensitive to organelle morphology but not directly to the size and shape of the cells. {copyright} 1998 Optical Society of America
Energy Technology Data Exchange (ETDEWEB)
Bradbury, E.M.
1992-06-01
We have made considerable progress in chromatin reconstitution with very lysine rich histone H1/H5 and in understanding the dynamics of nucleosomes. A ferromagnetic fluid was developed to align biological molecules for structural studies using small-angle-neutron-scattering. We have also identified and characterized in intrinsically bent DNA region flaking the RNA polymerase I binding site of the ribosomal RNA gene in Physarum Polycephalum. Finally projects in progress are in the areas of studying the interactions of histone H4 amino-terminus peptide 1-23 and acetylated 1-23 peptide with DNA using thermal denaturation; study of GGAAT repeats found in human centromeres using high resolution Nuclear Magnetic Resonance and nuclease sentivity assay; and the role of histones and other sperm specific proteins with sperm chromatin.
Energy Technology Data Exchange (ETDEWEB)
Bradbury, E.M.
1992-11-01
Despite of setbacks in the lack of neutrons for the proposed We have made considerable progress in chromatin reconstitution with the VLR histone H1/H5 and in understanding the dynamics of nucleosomes. A ferromagnetic fluid was developed to align biological molecules for structural studies using small-angle-neutron-scattering. We have also identified and characterized an intrinsically bent DNA region flanking the RNA polymerase I binding site of the ribosomal RNA gene in Physarum Polycephalum. Finally projects in progress are in the areas of studying the interatctions of histone H4 amino-terminus peptide 1-23 and acetylated 1-23 peptide with DNA using thermal denaturation; study of GGAAT repeats found in human centromeres using high resolution Nuclear magnetic Resonance and nuclease sentivity assay; and the role of histones and other sperm specific proteins with sperm chromatin.
Vakili, M; Auchincloss, P S; De Barbaro, P; Bazarko, A O; Bernstein, R H; Bodek, Arie; Bolton, T; Budd, H S; Conrad, J; De Barbaro, L; Harris, D A; Johnson, R A; Kim, J H; King, B J; Kinnel, T; Koizumi, G; Koutsoliotas, S; Lamm, M J; Lefmann, W C; Marsh, W; McFarland, K S; McNulty, C; Mishra, S R; Naples, D; Nienaber, P; Oreglia, M J; Perera, L P; Quintas, P Z; Romosan, A; Sakumoto, W K; Schumm, B A; Sciulli, F J; Seligman, W G; Shaevitz, M H; Smith, W H; Spentzouris, P; Steiner, R; Stern, E G; Yang, U K; Yu, J
2000-01-01
Data from the CCFR E770 Neutrino Deep Inelastic Scattering (DIS) experiment at Fermilab contain events with large Bjorken x (x>0.7) and high momentum transfer (Q^2>50 (GeV/c)^2). A comparison of the data with a model based on no nuclear effects at large x, shows a significant excess of events in the data. Addition of Fermi gas motion of the nucleons in the nucleus to the model does not explain the excess. Adding a higher momentum tail due to the formation of ``quasi-deuterons'' makes some improvement. An exponentially falling F_2 ``few-nucleon correlations'', can describe the data. A value of s=8.3 \\pm 0.7(stat.)\\pm 0.7(sys.) yields the best agreement with the data.
Schiemanck, S.K.; Kwakkel, G.; Post, M.W.; Prevo, A.J.
2006-01-01
OBJECTIVE: Ischemic lesion volume is assumed to be an important predictor of poststroke neurological deficits and functional outcome. This critical review examines the methodological quality of MRI studies and the predictive value of hemispheric infarct volume for neurological deficits (at body
Directory of Open Access Journals (Sweden)
Jacek OSKARBSKI
2017-04-01
Full Text Available Travel time is a measure commonly used for traffic flow modelling and traffic control. It also helps to evaluate the quality of traffic control systems in urban areas. Traffic control systems that use traffic models to predict changes and disruptions in vehicle flows have to use vehicle speed-prediction models. Travel time estimation studies the effects of traffic volumes on a street section at an average speed. The TRISTAR Integrated Transport Management System, currently being deployed across the Tri-City (Gdansk, Sopot, Gdynia, is almost completed and data obtained from the System can be useful for the development of prediction models. A procedure for travel speed model selection for the Tri-City street network is presented in this paper. Matching of chosen volume-delay functions to the data obtained from the TRISTAR has been tested. Analyses have shown insufficient matching of functions that does not justify the possibility of their use in traffic control due to variability in different conditions of traffic, weather and, in the case of an incident, which justifies the need for further research aimed at satisfying matching of functions depending on the above-mentioned factors.
Directory of Open Access Journals (Sweden)
Dai Shimamoto
2015-01-01
Full Text Available Purpose. To evaluate whether the diagnostic performance of Gd-EOB-DTPA-enhanced MRI in evaluating liver function and pathology is improved by considering liver volume (LV. Methods. This retrospective study included 104 patients who underwent Gd-EOB-DTPA-enhanced MRI before liver surgery. For each patient, using the precontrast and hepatobiliary phase images, we calculated the increase rate of the liver-to-spleen signal intensity ratio (LSR, that is, the “ΔLSR,” and the increase rate of the liver-to-muscle signal intensity ratio (LMR, that is, the “ΔLMR.” ΔLSR × LV and ΔLMR × LV were also calculated. The correlation of each MR parameter with liver function data or liver pathology was assessed. The correlation coefficients were compared between ΔLSR (ΔLMR and ΔLSR (ΔLMR × LV. Results. The correlation coefficient between ΔLSR (ΔLMR × LV and cholinesterase was significantly higher than that between ΔLSR (ΔLMR and cholinesterase. The correlation coefficient between ΔLSR (ΔLMR × LV and the degree of fibrosis or necroinflammatory activity was significantly lower than that between ΔLSR (ΔLMR and the degree of fibrosis or necroinflammatory activity. Conclusion. The inclusion of liver volume may improve Gd-EOB-DTPA-based predictions of liver function, but not in predictions of liver pathology.
Kelly, Philip A; Viding, Essi; Puetz, Vanessa B; Palmer, Amy L; Mechelli, Andrea; Pingault, Jean-Baptiste; Samuel, Sophie; McCrory, Eamon J
2015-11-01
While maltreatment is known to impact social and emotional functioning, threat processing, and neural structure, the potentially dimorphic influence of sex on these outcomes remains relatively understudied. We investigated sex differences across these domains in a large community sample of children aged 10 to 14 years (n = 122) comprising 62 children with verified maltreatment experience and 60 well-matched nonmaltreated peers. The maltreated group relative to the nonmaltreated comparison group exhibited poorer social and emotional functioning (more peer problems and heightened emotional reactivity). Cognitively, they displayed a pattern of attentional avoidance of threat in a visual dot-probe task. Similar patterns were observed in males and females in these domains. Reduced gray matter volume was found to characterize the maltreated group in the medial orbitofrontal cortex, bilateral middle temporal lobes, and bilateral supramarginal gyrus; sex differences were observed only in the supramarginal gyrus. In addition, a disordinal interaction between maltreatment exposure and sex was found in the postcentral gyrus. Finally, attentional avoidance to threat mediated the relationship between maltreatment and emotional reactivity, and medial orbitofrontal cortex gray matter volume mediated the relationship between maltreatment and peer functioning. Similar mediation patterns were observed across sexes. This study highlights the utility of combining multiple levels of analysis when studying the "latent vulnerability" engendered by childhood maltreatment and yields tentative findings regarding a neural basis of sex differences in long-term outcomes for maltreated children.
Dremin, I. M.
2013-01-01
Colliding high-energy hadrons either produce new particles or scatter elastically with their quantum numbers conserved and no other particles produced. We consider the latter case here. Although inelastic processes dominate at high energies, elastic scattering contributes considerably (18-25%) to the total cross section. Its share first decreases and then increases at higher energies. Small-angle scattering prevails at all energies. Some characteristic features can be seen that provide information on the geometrical structure of the colliding particles and the relevant dynamical mechanisms. The steep Gaussian peak at small angles is followed by the exponential (Orear) regime with some shoulders and dips, and then by a power-law decrease. Results from various theoretical approaches are compared with experimental data. Phenomenological models claiming to describe this process are reviewed. The unitarity condition predicts an exponential fall for the differential cross section with an additional substructure to occur exactly between the low momentum transfer diffraction cone and a power-law, hard parton scattering regime under high momentum transfer. Data on the interference of the Coulomb and nuclear parts of amplitudes at extremely small angles provide the value of the real part of the forward scattering amplitude. The real part of the elastic scattering amplitude and the contribution of inelastic processes to the imaginary part of this amplitude (the so-called overlap function) are also discussed. Problems related to the scaling behavior of the differential cross section are considered. The power-law regime at highest momentum transfer is briefly described.
Wang, Wei; Nallathamby, Prakash D.; Foster, Carmen M.; Morrell-Falvey, Jennifer L.; Mortensen, Ninell P.; Doktycz, Mitchel J.; Gu, Baohua; Retterer, Scott T.
2013-10-01
A new synthesis approach is described that allows the direct incorporation of fluorescent labels into the volume or body of SiO2 nanoparticles. In this process, fluorescent Alexa Fluor dyes with different emission wavelengths were covalently incorporated into the SiO2 nanoparticles during their formation by the hydrolysis of tetraethoxysilane. The dye molecules were homogeneously distributed throughout the SiO2 nanoparticles. The quantum yields of the Alexa Fluor volume-labeled SiO2 nanoparticles were much higher than nanoparticles labeled using conventional organic dyes. The size of the resulting nanoparticles was controlled using microemulsion reaction media with sizes in the range of 20-100 nm and a polydispersity of Fluor dyes with different emission wavelengths were covalently incorporated into the SiO2 nanoparticles during their formation by the hydrolysis of tetraethoxysilane. The dye molecules were homogeneously distributed throughout the SiO2 nanoparticles. The quantum yields of the Alexa Fluor volume-labeled SiO2 nanoparticles were much higher than nanoparticles labeled using conventional organic dyes. The size of the resulting nanoparticles was controlled using microemulsion reaction media with sizes in the range of 20-100 nm and a polydispersity of <15%. In comparison with conventional surface tagged particles created by post-synthesis modification, this process maintains the physical and surface chemical properties that have the most pronounced effect on colloidal stability and interactions with their surroundings. These volume-labeled nanoparticles have proven to be extremely robust, showing excellent signal strength, negligible photobleaching, and minimal loss of functional organic components. The native or ``free'' surface of the volume-labeled particles can be altered to achieve a specific surface functionality without altering fluorescence. Their utility was demonstrated for visualizing the association of surface-modified fluorescent particles
Institute of Scientific and Technical Information of China (English)
Aldo Monta(n)o-Loza; Max Schmulson; Sergio Zepeda-Gómez; Jose Maria Remes-Troche; Miguel Angel Valdovinos-Diaz
2005-01-01
AIM: Recently, drinking load tests with water or nutritional beverages have been proposed as diagnostic tools for functional dyspepsia (FD), therefore we sought to reproduce if these tests can discriminate between FD patients and controls in a Mexican population. METHODS: Twenty FD-Rome Ⅱ patients were matched by age and gender with 20 healthy controls. All underwent both drinking tests at a 15 mL/min rate, randomly, 7 d apart. Every 5 min within each test, four symptoms were evaluated (satiety, bloating, nausea and pain) by Likert scales. Maximum tolerated volume (MTV) was defined as the ingested volume when a score of 5 was reached for any symptom or when the test had to be stopped because the patients could not tolerate more volume. Sensitivity and specificity were analyzed. RESULTS: FD patients had higher symptom scores for both tests compared to controls (water: t= 4.1, P= 0.001 ＜0.01; Nutren(R): t= 5.2, P= 0.001＜0.01). The MTV forwater and Nutren(R) were significantly lower in FD (water: 1014±288 vs 1749±275 mL; t = 7.9, P = 0.001＜0.01;Nutren(R): 652±168 vs 1278±286 mL; t= 6.7, P = 0.001＜0.01). With the volume tolerated by the controls, the percentile 10 was determined as the lower limit fortolerance. Sensitivity and specificity were 0.90, 0.95 for water and 0.95, 0.95 for Nutren(R) tests.CONCLUSION: A drinking test with water or a nutritional beverage can discriminate between FD patients and healthy subjects in Mexico, with high sensitivity and specificity. These tests could be used as objective, noninvasive, and safe diagnostic approaches for FD patients.
Peces, Ramón; Peces, Carlos; Pérez-Dueñas, Virginia; Cuesta-López, Emilio; Azorín, Sebastián; Selgas, Rafael
2009-04-01
This is the first report of a case of a reduction in kidney volume and preservation of renal function in a patient with autosomal-dominant polycystic kidney disease (ADPKD) receiving rapamycin. A 42-year-old man with ADPKD and a severe persistent bleeding from his solitary left kidney was successfully treated with tranexamic acid (TXA). He also received low-dose rapamycin for 8 months, and this was associated with a 23.5% reduction in kidney volume, improvement and stabilization of renal function, and normalization of haemoglobin levels. When treatment with rapamycin was interrupted, renal function deteriorated within an 8-month period and haemodialysis (HD) became necessary. Kidney volume increased at once, and life-threatening bleeding prompted a nephrectomy 4 months after the onset of HD. These data suggest that the reduction in kidney volume and preservation of renal function with rapamycin could be the result of the antiangiogenic, antiproliferative effects of rapamycin.
Wave propagation and scattering in random media
Ishimaru, Akira
1978-01-01
Wave Propagation and Scattering in Random Media, Volume 2, presents the fundamental formulations of wave propagation and scattering in random media in a unified and systematic manner. The topics covered in this book may be grouped into three categories: waves in random scatterers, waves in random continua, and rough surface scattering. Random scatterers are random distributions of many particles. Examples are rain, fog, smog, hail, ocean particles, red blood cells, polymers, and other particles in a state of Brownian motion. Random continua are the media whose characteristics vary randomly an
Liu, Shasha; Zhao, Xiuming; Li, Yuanzuo; Zhao, Xiaohong; Chen, Maodu
2009-06-01
Density functional theory (DFT) and time-dependent DFT calculations have been performed to investigate the Raman scattering spectra of metal-molecule complex and metal-molecule-metal junction architectures interconnected with 4-aminothiophenol (PATP) molecule. The simulated profiles of normal Raman scattering (NRS) spectra for the two complexes (Ag2-PATP and PATP-Au2) and the two junctions (Ag2-PATP-Au2 and Au2-PATP-Ag2) are similar to each other, but exhibit obviously different Raman intensities. Due to the lager static polarizabilities of the two junctions, which directly influence the ground state chemical enhancement in NRS spectra, the calculated normal Raman intensities of them are stronger than those of two complexes by the factor of 102. We calculate preresonance Raman scattering (RRS) spectra with incident light at 1064 nm, which is much lower than the S1 electronic transition energy of complexes and junctions. Ag2-PATP-Au2 and Au2-PATP-Ag2 junctions yield higher Raman intensities than those of Ag2-PATP and PATP-Au2 complexes, especially for b2 modes. This effect is mainly attributed to charge transfer (CT) between the metal gap and the PAPT molecule which results in the occurrence of CT resonance enhancement. The calculated pre-RRS spectra strongly depend on the electronic transition state produced by new structures. With excitation at 514.5 nm, the calculated pre-RRS spectra of two complexes and two junctions are stronger than those of with excitation at 1064 nm. A charge difference densities methodology has been used to visually describe chemical enhancement mechanism of RRS spectrum. This methodology aims at visualizing intermolecular CT which provides direct evidence of the Herzberg-Teller mechanism.
Multiwavelength multistatic optical scattering for aerosol characterization
Brown, Andrea M.
geometric standard deviations within 2% of the correct value when inverting a single lognormal probability size distribution from simulated polarization ratios that include random Gaussian noise added to limit the signal-to-noise ratio to 25. The genetic algorithm performed reasonably well when retrieving results using a single complex refractive index for all three wavelengths while finding the lognormal particle size parameters. Three inversion runs of the algorithm on simulated noisy data showed that the algorithm could retrieved a trimodal size distribution and a single complex refractive index that produced a very good fit between the simulated noisy polarization ratios and the forward-calculated polarization ratios. A significant contribution of the present work is a set of tests conducted at the Environmental Protection Agency's (EPA) Aerosol Test Facility (ATF), which is a controlled environment, where direct measurements of the size distribution and concentration of the scattering volume are available. The aerosol size distribution results obtained from inversion of the measured scattering phase functions, a lognormal size distribution with a geometric mean diameter of ˜450 nm and a geometric standard deviation of ˜1.3, compare favorably with measurements from an aerodynamic particle sizer and a condensation particle counter. This is one of the first large scale experiments where a comparison between multistatic inversion results and known properties of the interrogated volume of aerosols are made under controlled conditions. The eventual goal is to develop a prototype sensor and an analysis approach to provide an important and useful tool to better define the atmospheric aerosol properties.
Patient-specific scatter correction for flat-panel detector-based cone-beam CT imaging.
Zhao, Wei; Brunner, Stephen; Niu, Kai; Schafer, Sebastian; Royalty, Kevin; Chen, Guang-Hong
2015-02-07
A patient-specific scatter correction algorithm is proposed to mitigate scatter artefacts in cone-beam CT (CBCT). The approach belongs to the category of convolution-based methods in which a scatter potential function is convolved with a convolution kernel to estimate the scatter profile. A key step in this method is to determine the free parameters introduced in both scatter potential and convolution kernel using a so-called calibration process, which is to seek for the optimal parameters such that the models for both scatter potential and convolution kernel is able to optimally fit the previously known coarse estimates of scatter profiles of the image object. Both direct measurements and Monte Carlo (MC) simulations have been proposed by other investigators to achieve the aforementioned rough estimates. In the present paper, a novel method has been proposed and validated to generate the needed coarse scatter profile for parameter calibration in the convolution method. The method is based upon an image segmentation of the scatter contaminated CBCT image volume, followed by a reprojection of the segmented image volume using a given x-ray spectrum. The reprojected data is subtracted from the scatter contaminated projection data to generate a coarse estimate of the needed scatter profile used in parameter calibration. The method was qualitatively and quantitatively evaluated using numerical simulations and experimental CBCT data acquired on a clinical CBCT imaging system. Results show that the proposed algorithm can significantly reduce scatter artefacts and recover the correct CT number. Numerical simulation results show the method is patient specific, can accurately estimate the scatter, and is robust with respect to segmentation procedure. For experimental and in vivo human data, the results show the CT number can be successfully recovered and anatomical structure visibility can be significantly improved.
Reduction of Pulmonary Function After Surgical Lung Resections of Different Volume
Cukic, Vesna
2014-01-01
Introduction: In recent years an increasing number of lung resections are being done because of the rising prevalence of lung cancer that occurs mainly in patients with limited lung function, what is caused with common etiologic factor - smoking cigarettes. Objective: To determine how big the loss of lung function is after surgical resection of lung of different range. Methods: The study was done on 58 patients operated at the Clinic for thoracic surgery KCU Sarajevo, previously treated at th...
Energy Technology Data Exchange (ETDEWEB)
Cansu, Aysegul, E-mail: drcansu@gmail.com; Kupeli, Ali; Kul, Sibel; Eyuboglu, Ilker; Oguz, Sukru; Ozturk, Mehmet Halil; Dinc, Hasan
2014-07-15
Purpose: To investigate the relationship between renal function and total renal volume-vascular indices using 3D power Doppler ultrasound (3DPDUS). Materials and methods: One hundred six patients with hypertensive proteinuric nephropathy (HPN) (49 male, 57 female) and 65 healthy controls (32 male, 33 female) were evaluated prospectively using 3DPDUS. Total renal volume (RV), vascularization index (VI), flow index (FI) and vascularization flow index (VFI) were calculated using Virtual Organ Computer-aided Analysis (VOCAL). The estimated glomerular filtration rates (GFRs) of the patients with HPN and the control group were calculated. The patients with HPN were divided into two groups on the basis of GFR, normal (≥90) or reduced (<90). Differences between groups were compared using ANOVA. Correlations between GFR, renal volume and vascular indices were analyzed using Pearson's correlation analysis. Significance was set at p < 0.05. Results: The mean total RV, VI, FI and VFI values in the reduced GFR, normal GFR and control groups were RV (ml): 234.7, 280.7 and 294.6; VI: 17.6, 27.6 and 46.8; FI: 79.1, 88.7 and 93.9 and VFI: 7.1, 12.7 and 23.8. There were statistically significant differences between the groups (p < 0.001). Total RVs and vascular indices exhibited significant correlations with estimated GFR (r = 0.53–0.59, p < 0.001) Conclusion: Three-dimensional power Doppler ultrasound is a reliable predictive technique in renal function analysis.
Wagner, Frank R; Kohout, Miroslav; Grin, Yuri
2008-10-01
The topological features, i.e., gradients and curvatures of the same-spin electron pair restricted electron localizability indicator (ELI-D) in position space are analyzed in terms of those of the electron density and the pair-volume function. The analysis of the topology of these constituent functions and their interplay on ELI-D attractor formation for a number of molecules representing chemically different bonding situations allows distinguishing between different chemical bonding scenarios on a quantum mechanical basis without the recourse to orbitals. The occurrence of the Laplacian of the electron density in the expression for the Laplacian of ELI-D allows us to establish a physical link between electron localizability and electron pairing as displayed by ELI-D and the role of Laplacian of the density in this context.
Eberhardt, Frank; Hanke, Thorsten; Fitschen, Joern; Heringlake, Matthias; Bode, Frank; Schunkert, Heribert; Wiegand, Uwe K H
2012-08-01
Atrioventricular (AV) interval optimization is often deemed too time-consuming in dual-chamber pacemaker patients with maintained LV function. Thus the majority of patients are left at their default AV interval. To quantify the magnitude of hemodynamic improvement following AV interval optimization in chronically paced dual chamber pacemaker patients. A pressure volume catheter was placed in the left ventricle of 19 patients with chronic dual chamber pacing and an ejection fraction >45 % undergoing elective coronary angiography. AV interval was varied in 10 ms steps from 80 to 300 ms, and pressure volume loops were recorded during breath hold. The average optimal AV interval was 152 ± 39 ms compared to 155 ± 8 ms for the average default AV interval (range 100-240 ms). The average improvement in stroke work following AV interval optimization was 935 ± 760 mmHg/ml (range 0-2,908; p AV interval changes the average stroke work by 207 ± 162 mmHg/ml. AV interval optimization also leads to improved systolic dyssynchrony indices (17.7 ± 7.0 vs. 19.4 ± 7.1 %; p = 0.01). The overall hemodynamic effect of AV interval optimization in patients with maintained LV function is in the same range as for patients undergoing cardiac resynchronization therapy for several parameters. The positive effect of AV interval optimization also applies to patients who have been chronically paced for years.
Morgan, Siân R; Dooley, Erin P; Hocking, Paul M; Inglehearn, Chris F; Ali, Manir; Sorensen, Thomas L-M; Meek, Keith M; Boote, Craig
2013-06-18
Avian vision diseases in which eye growth is compromised are helping to define what governs corneal shape and ultrastructural organization. The highly specific collagen architecture of the main corneal layer, the stroma, is believed to be important for the maintenance of corneal curvature and hence visual quality. Blindness enlarged globe (beg) is a recessively inherited condition of chickens characterized by retinal dystrophy and blindness at hatch, with secondary globe enlargement and loss of corneal curvature by 3-4 months. Here we define corneal ultrastructural changes as the beg eye develops posthatch, using wide-angle x-ray scattering to map collagen fibril orientation across affected corneas at three posthatch time points. The results disclosed alterations in the bulk alignment of corneal collagen in beg chicks compared with age-matched controls. These changes accompanied the eye globe enlargement and corneal flattening observed in affected birds, and were manifested as a progressive loss of circumferential collagen alignment in the peripheral cornea and limbus in birds older than 1 month. Progressive remodeling of peripheral stromal collagen in beg birds posthatch may relate to the morphometric changes exhibited by the disease, likely as an extension of myopia-like scleral remodeling triggered by deprivation of a retinal image.
Directory of Open Access Journals (Sweden)
Ibrahim Khalil
2016-05-01
Full Text Available Graphene is a single-atom-thick two-dimensional carbon nanosheet with outstanding chemical, electrical, material, optical, and physical properties due to its large surface area, high electron mobility, thermal conductivity, and stability. These extraordinary features of graphene make it a key component for different applications in the biosensing and imaging arena. However, the use of graphene alone is correlated with certain limitations, such as irreversible self-agglomerations, less colloidal stability, poor reliability/repeatability, and non-specificity. The addition of gold nanostructures (AuNS with graphene produces the graphene–AuNS hybrid nanocomposite which minimizes the limitations as well as providing additional synergistic properties, that is, higher effective surface area, catalytic activity, electrical conductivity, water solubility, and biocompatibility. This review focuses on the fundamental features of graphene, the multidimensional synthesis, and multipurpose applications of graphene–Au nanocomposites. The paper highlights the graphene–gold nanoparticle (AuNP as the platform substrate for the fabrication of electrochemical and surface-enhanced Raman scattering (SERS-based biosensors in diverse applications as well as SERS-directed bio-imaging, which is considered as an emerging sector for monitoring stem cell differentiation, and detection and treatment of cancer.
Energy Technology Data Exchange (ETDEWEB)
Díaz-Paniagua, Carlos [Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid (Spain); Urbina, Antonio, E-mail: a.urbina@imperial.ac.uk [Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom); Universidad Politécnica de Cartagena, Plaza del Hospital 1, 30202 Cartagena (Spain); García-Sakai, Victoria [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Seydel, Tilo [Institut Laue-Langevin, 39042 Grenoble Cedex (France); Abad, José; Padilla, Javier; García-Valverde, Rafael; Espinosa, Nieves [Universidad Politécnica de Cartagena, Plaza del Hospital 1, 30202 Cartagena (Spain); Gómez-Escalonilla, Marí a-José; Langa, Fernando [Instituto de Nanociencia, Nanotecnología y Materiales Moleculares (INAMOL), Universidad de Castilla-La Mancha, 45071 Toledo (Spain); Batallán, Francisco [Instituto de Ciencia de Materiales de Madrid, CSIC, 28049 Madrid (Spain)
2013-12-12
Highlights: • P3OT diffusion characteristic times in toluene solution at different temperatures have been obtained. • Gelation process for P3OT in solution has been demonstrated. • A methodology for elastic and quasielastic neutron scattering data analysis for liquids has been developed. - Abstract: Using both quasielastic and elastic window neutron spectroscopy, we study the molecular dynamics of poly-3-octyl-thiophene and of mixtures of carbon nanotube derivatives and poly-3-octyl-thiophene, both in deuterated toluene solutions. From the analysis of the experimental results of solutions for a broad range of concentrations, from very diluted to concentrated, different regimes of molecular motions are established, and a critical concentration between 2 and 3 wt% for the overlapping of macromolecules is obtained, including evidence of gelation processes for the higher concentrations driven by the entanglement of the macromolecules. Additionally, the temperature and momentum dependence of the characteristic times of the motions are obtained from the fit of the experimental data to stretched exponential models, delivering temperature dependent subnanosecond timescales for the diffusion of the macromolecule (0.02–0.5 ns)
Khalil, Ibrahim; Julkapli, Nurhidayatullaili Muhd; Yehye, Wageeh A.; Basirun, Wan Jefrey; Bhargava, Suresh K.
2016-01-01
Graphene is a single-atom-thick two-dimensional carbon nanosheet with outstanding chemical, electrical, material, optical, and physical properties due to its large surface area, high electron mobility, thermal conductivity, and stability. These extraordinary features of graphene make it a key component for different applications in the biosensing and imaging arena. However, the use of graphene alone is correlated with certain limitations, such as irreversible self-agglomerations, less colloidal stability, poor reliability/repeatability, and non-specificity. The addition of gold nanostructures (AuNS) with graphene produces the graphene–AuNS hybrid nanocomposite which minimizes the limitations as well as providing additional synergistic properties, that is, higher effective surface area, catalytic activity, electrical conductivity, water solubility, and biocompatibility. This review focuses on the fundamental features of graphene, the multidimensional synthesis, and multipurpose applications of graphene–Au nanocomposites. The paper highlights the graphene–gold nanoparticle (AuNP) as the platform substrate for the fabrication of electrochemical and surface-enhanced Raman scattering (SERS)-based biosensors in diverse applications as well as SERS-directed bio-imaging, which is considered as an emerging sector for monitoring stem cell differentiation, and detection and treatment of cancer. PMID:28773528
Adeva, B; Arvidson, A; Badelek, B; Bardin, G; Baum, G; Berglund, P; Betev, L; Birsa, R; De Botton, N R; Bradamante, Franco; Bravar, A; Bressan, A; Bültmann, S; Burtin, E; Crabb, D; Cranshaw, J; Çuhadar-Dönszelmann, T; Dalla Torre, S; Van Dantzig, R; Derro, B R; Deshpande, A A; Dhawan, S K; Dulya, C M; Eichblatt, S; Fasching, D; Feinstein, F; Fernández, C; Forthmann, S; Frois, Bernard; Gallas, A; Garzón, J A; Gilly, H; Giorgi, M A; Görtz, S; Gracia, G; De Groot, N; Haft, K; Von Harrach, D; Hasegawa, T; Hautle, P; Hayashi, N; Heusch, C A; Horikawa, N; Hughes, V W; Igo, G; Ishimoto, S; Iwata, T; Kabuss, E M; Kageya, T; Karev, A G; Ketel, T; Kiryluk, J; Kiselev, Yu F; Krivokhizhin, V G; Kröger, W; Kukhtin, V V; Kurek, K; Kyynäräinen, J; Lamanna, M; Landgraf, U; Le Goff, J M; Lehár, F; de Lesquen, A; Lichtenstadt, J; Litmaath, M; Magnon, A; Mallot, G K; Marie, F; Martin, A; Martino, J; Matsuda, T; Mayes, B W; McCarthy, J S; Medved, K S; Meyer, W T; Van Middelkoop, G; Miller, D; Miyachi, Y; Mori, K; Moromisato, J H; Nassalski, J P; Naumann, Lutz; Niinikoski, T O; Oberski, J; Ogawa, A; Grosse-Perdekamp, M; Pereira, H; Perrot-Kunne, F; Peshekhonov, V D; Pinsky, L; Platchkov, S K; Pló, M; Pose, D; Postma, H; Pretz, J; Puntaferro, R; Rädel, G; Rijllart, A; Reicherz, G; Rodríguez, M; Rondio, Ewa; Roscherr, B; Sabo, I; Saborido, J; Sandacz, A; Savin, I A; Schiavon, R P; Schiller, A; Sichtermann, E P; Simeoni, F; Smirnov, G I; Staude, A; Steinmetz, A; Stiegler, U; Stuhrmann, H B; Szleper, M; Tessarotto, F; Thers, D; Tlaczala, W; Tripet, A; Ünel, G; Velasco, M; Vogt, J; Voss, Rüdiger; Whitten, C; Windmolders, R; Wislicki, W; Witzmann, A; Ylöstalo, J; Zanetti, A M; Zaremba, K
1997-01-01
We present a new measurement of the virtual photon proton asymmetry $A_1^{\\rm p}$ from deep inelastic scattering of polarized muons on polarized protons in the kinematic range $0.0008 1$ GeV$^{2}$. A perturbative QCD evolution in next-to-leading order is used to determine $g_1^{\\rm p}(x)$ at a constant $Q^2$. At $Q^{2} = 10$ GeV$^{2}$ we find, in the measured range, $\\int_{0.003}^{0.7} g_{1}^{\\rm p}(x){\\rm d}x = 0.139 \\pm 0.006~({\\rm stat})\\pm 0.008~({\\rm syst)} \\pm 0.006~({\\rm evol})$. The value of the first moment $\\Gamma_{1}^{\\rm p} = \\int_{0}^{1} g_{1}^{\\rm p}(x){\\rm d}x$ of $g_{1}^{\\rm p}$ depends on the approach used to describe the behaviour of $g_{1}^{\\rm p}$ at low $x$. We find that the Ellis-Jaffe sum rule is violated. With our published result for $\\Gamma_{1}^{\\rm d}$ we confirm the Bjorken sum rule with an accuracy of $\\approx 15\\%$ at the one standard deviation level.
Day, Derek E.; Malm, William C.
The water uptake by fine aerosol particles in the atmosphere has been investigated at three rural National Parks in the United States (Great Smoky Mountains, Grand Canyon and Big Bend National Parks). The relative humidity (RH) of sample aerosols was varied from less than 20% to greater than 90% using Perma Pure drying tubes as the scattering coefficient of the aerosol was measured with a Radiance Research M903 nephelometer. Data from these studies show that growth curves at all the three sites are similar in shape but the magnitude of growth can vary considerably from day to day. The growth curves from Great Smoky Mountains show smooth continuous growth over the entire range of RH, while the growth curves from the Grand Canyon and Big Bend show smooth and continuous growth on some days and deliquescence on other days. Comparing 12-h filter samples of chemical composition data with the aerosol growth curves, we find that higher fractions of soluble inorganic compounds (sulfate and nitrate) produce growth curves of greater magnitude than do higher concentrations of either organic carbon or soil material.
Energy Technology Data Exchange (ETDEWEB)
Silverstein, Daniel W.; Govind, Niranjan; van Dam, Hubertus J. J.; Jensen, Lasse
2013-12-10
A parallel implementation of analytical time-dependent density functional theory gradients is presented for the quantum chemistry program NWChem. The implementation is based on the Lagrangian approach developed by Furche and Ahlrichs. To validate our implementation, we first calculate the Stokes shifts for a range of organic dye molecules using a diverse set of exchange-correlation functionals (traditional density functionals, global hybrids, and range-separated hybrids) followed by simulations of the one-photon absorption and resonance Raman scattering spectrum of the phenoxyl radical, the well-studied dye molecule rhodamine 6G, and a molecular host–guest complex (TTFcCBPQT^{4+}). The study of organic dye molecules illustrates that B3LYP and CAM-B3LYP generally give the best agreement with experimentally determined Stokes shifts unless the excited state is a charge transfer state. Absorption, resonance Raman, and fluorescence simulations for the phenoxyl radical indicate that explicit solvation may be required for accurate characterization. For the host–guest complex and rhodamine 6G, it is demonstrated that absorption spectra can be simulated in good agreement with experimental data for most exchange-correlation functionals. Finally, however, because one-photon absorption spectra generally lack well-resolved vibrational features, resonance Raman simulations are necessary to evaluate the accuracy of the exchange-correlation functional for describing a potential energy surface.
Estimating seabed scattering mechanisms via Bayesian model selection.
Steininger, Gavin; Dosso, Stan E; Holland, Charles W; Dettmer, Jan
2014-10-01
A quantitative inversion procedure is developed and applied to determine the dominant scattering mechanism (surface roughness and/or volume scattering) from seabed scattering-strength data. The classification system is based on trans-dimensional Bayesian inversion with the deviance information criterion used to select the dominant scattering mechanism. Scattering is modeled using first-order perturbation theory as due to one of three mechanisms: Interface scattering from a rough seafloor, volume scattering from a heterogeneous sediment layer, or mixed scattering combining both interface and volume scattering. The classification system is applied to six simulated test cases where it correctly identifies the true dominant scattering mechanism as having greater support from the data in five cases; the remaining case is indecisive. The approach is also applied to measured backscatter-strength data where volume scattering is determined as the dominant scattering mechanism. Comparison of inversion results with core data indicates the method yields both a reasonable volume heterogeneity size distribution and a good estimate of the sub-bottom depths at which scatterers occur.
Directory of Open Access Journals (Sweden)
Monir Sharifi
2012-05-01
Full Text Available Periodic mesoporous materials of the type (R′O3Si-R-Si(OR′3 with benzene as an organic bridge and a crystal-like periodicity within the pore walls were functionalized with SO3H or SO3− groups and investigated by small-angle neutron scattering (SANS with in situ nitrogen adsorption at 77 K. If N2 is adsorbed in the pores the SANS measurements show a complete matching of all of the diffraction signals that are caused by the long-range ordering of the mesopores in the benzene-PMO, due to the fact that the benzene-PMO walls possess a neutron scattering length density (SLD similar to that of nitrogen in the condensed state. However, signals at higher q-values (>1 1/Å are not affected with respect to their SANS intensity, even after complete pore filling, confirming the assumption of a crystal-like periodicity within the PMO material walls due to π–π interactions between the organic bridges. The SLD of pristine benzene-PMO was altered by functionalizing the surface with different amounts of SO3H-groups, using the grafting method. For a low degree of functionalization (0.81 mmol SO3H·g−1 and/or an inhomogeneous distribution of the SO3H-groups, the SLD changes only negligibly, and thus, complete contrast matching is still found. However, for higher amounts of SO3H-groups (1.65 mmol SO3H·g−1 being present in the mesopores, complete matching of the neutron diffraction signals is no longer observed proving that homogeneously distributed SO3H-groups on the inner pore walls of the benzene-PMO alter the SLD in a way that it no longer fits to the SLD of the condensed N2.
Aoyama, T; Kinoshita, T; Nio, M; Watanabe, N
2008-01-01
We have evaluated the contribution to the anomalous magnetic moment of the electron from six tenth-order Feynman diagrams which contain eighth-order vacuum-polarization function formed by two light-by-light scattering diagrams connected by three photons. The integrals are constructed by two different methods. In the first method the subtractive counter terms are used to deal with ultraviolet (UV) singularities together with the requirement of gauge-invariance. In the second method, the Ward-Takahashi identity is applied to the light-by-light scattering amplitudes to eliminate UV singularities. Numerical evaluation confirms that the two methods are consistent with each other within their numerical uncertainties. Combining the two results statistically and adding small contribution from the muons and/or tau leptons, we obtain $ 0.000 399 9 (18) (\\alpha/\\pi)^5$. We also evaluated the contribution to the muon $g-2$ from the same set of diagrams and found $ -1.263 44 (14) (\\alpha/\\pi)^5$.
Energy Technology Data Exchange (ETDEWEB)
Mang, Joseph Thomas [Los Alamos National Laboratory; Hjelm, Rex P [Los Alamos National Laboratory; Francois, Elizabeth G [Los Alamos National Laboratory
2009-01-01
We have used ultra-small-angle neutron scattering (USANS) with contrast variation to measure the porosity (voids and binder-filled regions) in a composite high explosive, PBX 9501, formulated with a deuterated binder. Little is known about the microstructure of pressed PBX 9501 parts and thus how it is affected by processing. Here, we explore the effect of varying the pressing intensity on the PBX 9501 microstructure. Disk-shaped samples of PBX 9501 were die-pressed with applied pressures ranging between 10,000 and 29,000 psi at 90 C. Five samples were prepared at each pressure that differed in the fraction of deuterated binder, facilitating variation of the neutron scattering length density contrast ({Delta}{rho}) and thus, the resolution of microstructural details. The sample composition was determined by calculation of the Porod Invariant as a function of {Delta}{rho} and compared with compositional estimates obtained from the bulk sample density. Structural modeling of the USANS data, at different levels of contrast, assuming both spherical and cylindrical morphologies, allowed the mean size and size distribution of voids and binder-filled regions to be determined. A decrease in the mean diameter of binder-filled regions was found with increasing pressing intensity, while the mean void diameter showed no significant change.
Davis, A. B.
2015-12-01
Planetary atmospheres are made primarily of molecules, and their optical properties are well known. They scatter sunlight across the spectrum, but far more potently at shorter wavelengths. Consequently, they redden the Sun as it sets and, at the same time, endow the daytime sky with its characteristic blue hue. There are also microscopic atmospheric particulates that are equally omnipresent because small enough (up to ~10s of microns) to remain lofted for long periods of time. However, in contrast with molecules of the major gases, their concentrations are highly variable in space and time. Their optical properties are also far more interesting. These airborne particles are either solid---hence the word "aerosols"---or liquid, most notably in the form of cloud droplets. Needless to say that both aerosols and clouds have major impacts on the balance of the Earth's climate system. Harder to understand, but nonetheless true, is that their climate impacts are much harder to assess by Earth system modelers than those of greenhouse gases such as CO2. That makes them prime targets of study by multiple approaches, including ground- and space-based remote sensing. To characterize aerosols and clouds quantitatively by optical remote sensing methods, either passive (sunlight-based) or active (laser-based), we need predictive capability for the signals recorded by sensors, whether ground-based, airborne, or carried by satellites. This in turn draws on the physical theory of "radiative transfer" that describes how the light propagates and scatters in the molecular-and-particulate atmosphere. This is a challenge for remote sensing scientists. I will show why by simulating with simple means the point spread function or "PSF" of scattering particulate atmospheres with varying opacity, thus covering tabletop analogs of the pristine air, the background aerosol, all the way to optically thick cloudy airmasses. I will also show PSF measurements of real clouds over New Mexico and
Correlation functions between specific volume and stoichiometry for transition metal nitrides
Energy Technology Data Exchange (ETDEWEB)
Soto, G. [Centro de Ciencias de la Materia Condensada, UNAM, Ap. Postal 2681, 22800 Ensenada B. C. (Mexico)]. E-mail: gerardo@ccmc.unam.mx; Aparicio, E. [Centro de Ciencias de la Materia Condensada, UNAM, Ap. Postal 2681, 22800 Ensenada B. C. (Mexico); Avalos-Borja, M. [Centro de Ciencias de la Materia Condensada, UNAM, Ap. Postal 2681, 22800 Ensenada B. C. (Mexico)
2005-03-08
A methodology is proposed to correlate the structural aspects of transition metal nitrides (TMN) to the stoichiometric ratio: x = [N]/[M]. The method is based on a numeric figure, {upsilon}, given by the difference between the atomic concentrations of nitride and parent metal normalized to the atomic concentration of parent metal. Numerical regression is used to construct interpolating functions for {upsilon}(x) using as input the available data for TMN in two well-recognized databases (ICDD and ICSD). In summary we obtain functions of x that describe the deformation caused in the parent metal lattice by the nitrogen assimilation. The results are attractive, since TMN show remarkable trends.
Heterodyne Near-Field Scattering
Brogioli, D; Giglio, M; Giglio, Marzio
2002-01-01
We describe an optical technique based on the statistical analysis of the random intensity distribution due to the interference of the near-field scattered light with the strong transmitted beam. It is shown that, from the study of the two-dimensional power spectrum of the intensity, one derives the scattered intensity as a function of the scattering wave vector. Near-field conditions are specified and discussed. The substantial advantages over traditional scattering technique are pointed out, and is indicated that the technique could be of interest for wave lengths other than visible light.
Functional Significance of Iron Deficiency. Annual Nutrition Workshop Series, Volume III.
Enwonwu, Cyril O., Ed.
Iron deficiency anemia impairs cognitive performance, physical capacity, and thermoregulation. Recent evidence suggests that these functional impairments are also evident in subclinical nonanemic iron deficiency. Very little is known about the relevance of the latter to the health of blacks, who have been shown to have the highest prevalence of…
van Osch, MJP; Vonken, EJPA; Bakker, CJG; Viergever, MA
2001-01-01
To quantify cerebral perfusion with dynamic susceptibility contrast MRI (DSC-MRI), one needs to measure the arterial input function (AIF). Conventionally, one derives the contrast concentration from the DSC sequence by monitoring changes in either the amplitude or the phase signal on the assumption
Novel Measures of Volume Status and Cardiac Function in Traumatic Shock
2016-06-01
Focused rapid echocardiographic evaluation versus vascular catheter-based assessment of cardiac output and function in critically ill trauma ...adequacy of resuscitation in patients with traumatic shock and (2) to determine the incidence, time course, and clinical relevance of trauma ...evaluation serially over time in a civilian model of military trauma . Upon closure of the study, only six patients were enrolled, so no association
Cold Spring Harbor symposia on quantitative biology: Volume 52, Evolution of catalytic function
Energy Technology Data Exchange (ETDEWEB)
1987-01-01
This document contains 97 papers presented at the symposium. The primary topic was the evolution of the catalytic function. Speakers discussed the evolution of genetic apparatus, the primordial soup, the anatomy of RNA, RNA templates, protein assembly, protein structure, cofactors, ribosomes, exons, and introns. Individual papers were processed separately for the data base. (TEM)
1975-01-01
The findings are presented of investigations on concepts and techniques in automated performance verification. The investigations were conducted to provide additional insight into the design methodology and to develop a consolidated technology base from which to analyze performance verification design approaches. Other topics discussed include data smoothing, function selection, flow diagrams, data storage, and shuttle hydraulic systems.
Increasing the imaging depth through computational scattering correction (Conference Presentation)
Koberstein-Schwarz, Benno; Omlor, Lars; Schmitt-Manderbach, Tobias; Mappes, Timo; Ntziachristos, Vasilis
2016-03-01
Imaging depth is one of the most prominent limitations in light microscopy. The depth in which we are still able to resolve biological structures is limited by the scattering of light within the sample. We have developed an algorithm to compensate for the influence of scattering. The potential of algorithm is demonstrated on a 3D image stack of a zebrafish embryo captured with a selective plane illumination microscope (SPIM). With our algorithm we were able shift the point in depth, where scattering starts to blur the imaging and effect the image quality by around 30 µm. For the reconstruction the algorithm only uses information from within the image stack. Therefore the algorithm can be applied on the image data from every SPIM system without further hardware adaption. Also there is no need for multiple scans from different views to perform the reconstruction. The underlying model estimates the recorded image as a convolution between the distribution of fluorophores and a point spread function, which describes the blur due to scattering. Our algorithm performs a space-variant blind deconvolution on the image. To account for the increasing amount of scattering in deeper tissue, we introduce a new regularizer which models the increasing width of the point spread function in order to improve the image quality in the depth of the sample. Since the assumptions the algorithm is based on are not limited to SPIM images the algorithm should also be able to work on other imaging techniques which provide a 3D image volume.
Zhang, Cong-yun; Hao, Rui; Zhao, Bin; Hao, Yao-wu; Liu, Ya-qing
2017-07-01
The graphene-mediated surface enhanced Raman scattering (SERS) substrates by virtues of plasmonic metal nanostructures and graphene or its derivatives have attracted tremendous interests which are expected to make up the deficiency of traditional plasmonic metal substrates. Herein, we designed and fabricated a novel ternary Ag@GO@Au sandwich hybrid wherein the ultrathin graphene oxide (GO) films were seamlessly wrapped around the hierarchical flower-like Ag particle core and meanwhile provided two-dimensional anchoring scaffold for the coating of Au nanoparticles (NPs). The surface coverage density of loading Au NPs could be readily controlled by tuning the dosage amount of Au particle solutions. These features endowed the sandwiched structures high enrichment capability for analytes such as aromatic molecules and astonishing SERS performance. The Raman signals were enormously enhanced with an ultrasensitive detection limit of rhodamine-6G (R6G) as low as 10-13 M based on the chemical enhancement from GO and multi-dimensional plasmonic coupling between the metal nanoparticles. In addition, the GO interlayer as an isolating shell could effectively prevent the metal-molecule direct interaction and suppress the oxidation of Ag after exposure at ambient condition which enabled the substrates excellent reproducibility with less than 6% signal variations and prolonged life-time. To evaluate the feasibility and the practical application for SERS detection in real-world samples based on GO sandwiched hybrid as SERS-active substrate, three different prohibited colorants with a series of concentrations were measured with a minimum detected concentration down to 10-9 M. Furthermore, the prepared GO sandwiched nanostructures can be used to identify different types of colorants existing in red wine, implying the great potential applications for single-particle SERS sensing of biotechnology and on-site monitoring in food security.
Interaction of the endocrine system with inflammation: a function of energy and volume regulation
2014-01-01
During acute systemic infectious disease, precisely regulated release of energy-rich substrates (glucose, free fatty acids, and amino acids) and auxiliary elements such as calcium/phosphorus from storage sites (fat tissue, muscle, liver, and bone) are highly important because these factors are needed by an energy-consuming immune system in a situation with little or no food/water intake (sickness behavior). This positively selected program for short-lived infectious diseases is similarly applied during chronic inflammatory diseases. This review presents the interaction of hormones and inflammation by focusing on energy storage/expenditure and volume regulation. Energy storage hormones are represented by insulin (glucose/lipid storage and growth-related processes), insulin-like growth factor-1 (IGF-1) (muscle and bone growth), androgens (muscle and bone growth), vitamin D (bone growth), and osteocalcin (bone growth, support of insulin, and testosterone). Energy expenditure hormones are represented by cortisol (breakdown of liver glycogen/adipose tissue triglycerides/muscle protein, and gluconeogenesis; water retention), noradrenaline/adrenaline (breakdown of liver glycogen/adipose tissue triglycerides, and gluconeogenesis; water retention), growth hormone (glucogenic, lipolytic; has also growth-related aspects; water retention), thyroid gland hormones (increase metabolic effects of adrenaline/noradrenaline), and angiotensin II (induce insulin resistance and retain water). In chronic inflammatory diseases, a preponderance of energy expenditure pathways is switched on, leading to typical hormonal changes such as insulin/IGF-1 resistance, hypoandrogenemia, hypovitaminosis D, mild hypercortisolemia, and increased activity of the sympathetic nervous system and the renin-angiotensin-aldosterone system. Though necessary during acute inflammation in the context of systemic infection or trauma, these long-standing changes contribute to increased mortality in chronic
Energy Technology Data Exchange (ETDEWEB)
Schaefer, A. [Saarland University Medical Centre, Department of Nuclear Medicine, Homburg (Germany); Vermandel, M. [U1189 - ONCO-THAI - Image Assisted Laser Therapy for Oncology, University of Lille, Inserm, CHU Lille, Lille (France); CHU Lille, Nuclear Medicine Department, Lille (France); Baillet, C. [CHU Lille, Nuclear Medicine Department, Lille (France); Dewalle-Vignion, A.S. [U1189 - ONCO-THAI - Image Assisted Laser Therapy for Oncology, University of Lille, Inserm, CHU Lille, Lille (France); Modzelewski, R.; Vera, P.; Gardin, I. [Centre Henri-Becquerel and LITIS EA4108, Rouen (France); Massoptier, L.; Parcq, C.; Gibon, D. [AQUILAB, Research and Innovation Department, Loos Les Lille (France); Fechter, T.; Nestle, U. [University Medical Center Freiburg, Department for Radiation Oncology, Freiburg (Germany); German Cancer Consortium (DKTK) Freiburg and German Cancer Research Center (DKFZ), Heidelberg (Germany); Nemer, U. [University Medical Center Freiburg, Department of Nuclear Medicine, Freiburg (Germany)
2016-05-15
The aim of this study was to evaluate the impact of consensus algorithms on segmentation results when applied to clinical PET images. In particular, whether the use of the majority vote or STAPLE algorithm could improve the accuracy and reproducibility of the segmentation provided by the combination of three semiautomatic segmentation algorithms was investigated. Three published segmentation methods (contrast-oriented, possibility theory and adaptive thresholding) and two consensus algorithms (majority vote and STAPLE) were implemented in a single software platform (Artiview registered). Four clinical datasets including different locations (thorax, breast, abdomen) or pathologies (primary NSCLC tumours, metastasis, lymphoma) were used to evaluate accuracy and reproducibility of the consensus approach in comparison with pathology as the ground truth or CT as a ground truth surrogate. Variability in the performance of the individual segmentation algorithms for lesions of different tumour entities reflected the variability in PET images in terms of resolution, contrast and noise. Independent of location and pathology of the lesion, however, the consensus method resulted in improved accuracy in volume segmentation compared with the worst-performing individual method in the majority of cases and was close to the best-performing method in many cases. In addition, the implementation revealed high reproducibility in the segmentation results with small changes in the respective starting conditions. There were no significant differences in the results with the STAPLE algorithm and the majority vote algorithm. This study showed that combining different PET segmentation methods by the use of a consensus algorithm offers robustness against the variable performance of individual segmentation methods and this approach would therefore be useful in radiation oncology. It might also be relevant for other scenarios such as the merging of expert recommendations in clinical routine and
Interaction of the endocrine system with inflammation: a function of energy and volume regulation.
Straub, Rainer H
2014-02-13
During acute systemic infectious disease, precisely regulated release of energy-rich substrates (glucose, free fatty acids, and amino acids) and auxiliary elements such as calcium/phosphorus from storage sites (fat tissue, muscle, liver, and bone) are highly important because these factors are needed by an energy-consuming immune system in a situation with little or no food/water intake (sickness behavior). This positively selected program for short-lived infectious diseases is similarly applied during chronic inflammatory diseases. This review presents the interaction of hormones and inflammation by focusing on energy storage/expenditure and volume regulation. Energy storage hormones are represented by insulin (glucose/lipid storage and growth-related processes), insulin-like growth factor-1 (IGF-1) (muscle and bone growth), androgens (muscle and bone growth), vitamin D (bone growth), and osteocalcin (bone growth, support of insulin, and testosterone). Energy expenditure hormones are represented by cortisol (breakdown of liver glycogen/adipose tissue triglycerides/muscle protein, and gluconeogenesis; water retention), noradrenaline/adrenaline (breakdown of liver glycogen/adipose tissue triglycerides, and gluconeogenesis; water retention), growth hormone (glucogenic, lipolytic; has also growth-related aspects; water retention), thyroid gland hormones (increase metabolic effects of adrenaline/noradrenaline), and angiotensin II (induce insulin resistance and retain water). In chronic inflammatory diseases, a preponderance of energy expenditure pathways is switched on, leading to typical hormonal changes such as insulin/IGF-1 resistance, hypoandrogenemia, hypovitaminosis D, mild hypercortisolemia, and increased activity of the sympathetic nervous system and the renin-angiotensin-aldosterone system. Though necessary during acute inflammation in the context of systemic infection or trauma, these long-standing changes contribute to increased mortality in chronic
1975-01-01
A system analysis of the shuttle orbiter baseline system management (SM) computer function is performed. This analysis results in an alternative SM design which is also described. The alternative design exhibits several improvements over the baseline, some of which are increased crew usability, improved flexibility, and improved growth potential. The analysis consists of two parts: an application assessment and an implementation assessment. The former is concerned with the SM user needs and design functional aspects. The latter is concerned with design flexibility, reliability, growth potential, and technical risk. The system analysis is supported by several topical investigations. These include: treatment of false alarms, treatment of off-line items, significant interface parameters, and a design evaluation checklist. An in-depth formulation of techniques, concepts, and guidelines for design of automated performance verification is discussed.
Aaron, F D; Andreev, V; Backovic, S; Baghdasaryan, A; Baghdasaryan, S; Barrelet, E; Bartel, W; Behrend, O; Belov, P; Begzsuren, K; Belousov, A; Bizot, J C; Boudry, V; Bozovic-Jelisavcic, I; Bracinik, J; Brandt, G; Brinkmann, M; Brisson, V; Britzger, D; Bruncko, D; Bunyatyan, A; Buschhorn, G; Bylinkin, A; Bystritskaya, L; Campbell, A J; Cantun Avila, K B; Ceccopieri, F; Cerny, K; Cerny, V; Chekelian, V; Cholewa, A; Contreras, J G; Coughlan, J A; Cvach, J; Dainton, J B; Daum, K; Delcourt, B; Delvax, J; De Wolf, E A; Diaconu, C; Dobre, M; Dodonov, V; Dossanov, A; Dubak, A; Eckerlin, G; Egli, S; Eliseev, A; Elsen, E; Favart, L; Fedotov, A; Felst, R; Feltesse, J; Ferencei, J; Fischer, D J; Fleischer, M; Fomenko, A; Gabathuler, E; Gayler, J; Ghazaryan, S; Glazov, A; Goerlich, L; Gogitidze, N; Gouzevitch, M; Grab, C; Grebenyuk, A; Greenshaw, T; Grell, B R; Grindhammer, G; Habib, S; Haidt, D; Helebrant, C; Henderson, R C.W; Hennekemper, E; Henschel, H; Herbst, M; Herrera, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R; Hreus, T; Huber, F; Jacquet, M; Janssen, X; Jonsson, L; Jung, A W; Jung, H; Kapichine, M; Katzy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Kluge, T; Knutsson, A; Kogler, R; Kostka, P; Kraemer, M; Kretzschmar, J; Kruger, K; Kutak, K; Landon, M P.J; Lange, W; Lastovicka-Medin, G; Laycock, P; Lebedev, A; Lendermann, V; Levonian, S; Lipka, K; List, B; List, J; Loktionova, N; Lopez-Fernandez, R; Lubimov, V; Makankine, A; Malinovski, E; Marage, P; Martyn, H U; Maxfield, S J; Mehta, A; Meyer, A B; Meyer, H; Meyer, J; Mikocki, S; Milcewicz-Mika, I; Moreau, F; Morozov, A; Morris, J V; Mozer, M U; Mudrinic, M; Muller, K; Naumann, Th; Newman, P R; Niebuhr, C; Nikiforov, A; Nikitin, D; Nowak, G; Nowak, K; Olsson, J E; Osman, S; Ozerov, D; Pahl, P; Palichik, V; Panagoulias, I; Pandurovic, M; Papadopoulou, Th; Pascaud, C; Patel, G D; Perez, E; Petrukhin, A; Picuric, I; Piec, S; Pirumov, H; Pitzl, D; Placakyte, R; Pokorny, B; Polifka, R; Povh, B; Radescu, V; Raicevic, N; Ravdandorj, T; Reimer, P; Rizvi, E; Robmann, P; Roosen, R; Rostovtsev, A; Rotaru, M; Ruiz Tabasco, J E; Rusakov, S; Salek, D; Sankey, D P.C; Sauter, M; Sauvan, E; Schmitt, S; Schoeffel, L; Schoning, A; Schultz-Coulon, H C; Sefkow, F; Shtarkov, L N; Shushkevich, S; Sloan, T; Smiljanic, I; Soloviev, Y; Sopicki, P; South, D; Spaskov, V; Specka, A; Staykova, Z; Steder, M; Stella, B; Stoicea, G; Straumann, U; Sykora, T; Thompson, P D; Toll, T; Tran, T H; Traynor, D; Truol, P; Tsakov, I; Tseepeldorj, B; Tsurin, I; Turnau, J; Urban, K; Valkarova, A; Vallee, C; Van Mechelen, P; Vargas, A; Vazdik, Y; von den Driesch, M; Wegener, D; Wunsch, E; Zacek, J; Zalesak, J; Zhang, Z; Zhokin, A; Zohrabyan, H; Zomer, F
2011-01-01
A measurement is presented of the inclusive neutral current e\\pm p scattering cross section using data collected by the H1 experiment at HERA during the years 2003 to 2007 with proton beam energies Ep of 920, 575, and 460 GeV. The kinematic range of the measurement covers low absolute four-momentum transfers squared, 1.5 GeV2 < Q2 < 120 GeV2, small values of Bjorken x, 2.9 \\cdot 10-5 < x < 0.01, and extends to high inelasticity up to y = 0.85. The structure function FL is measured by combining the new results with previously published H1 data at Ep = 920 GeV and Ep = 820 GeV. The new measurements are used to test several phenomenological and QCD models applicable in this low Q2 and low x kinematic domain.
Nielsen, S. K.; Stejner, M.; Rasmussen, J.; Jacobsen, A. S.; Korsholm, S. B.; Leipold, F.; Maraschek, M.; Meo, F.; Michelsen, P. K.; Moseev, D.; Salewski, M.; Schubert, M.; Stober, J.; Suttrop, W.; Tardini, G.; Wagner, D.
2015-03-01
Collective Thomson scattering (CTS) can provide measurements of the confined fast-ion distribution function resolved in space, time and 1D velocity space. On ASDEX Upgrade, the measured spectra include an additional signal which previously has hampered data interpretation. A new set-up using two independent heterodyne receiver systems enables subtraction of the additional part from the total spectrum, revealing the resulting CTS spectrum. Here we present CTS measurements from the plasma centre obtained in L-mode and H-mode plasmas with and without neutral beam injection (NBI). For the first time, the measured spectra agree quantitatively with the synthetic spectra in periods with and without NBI heating. For the discharges investigated, the central velocity distribution of neutral beam ions can be described by classical slowing down. These results will have a major impact on ITER physics exploration, since CTS is presently the only diagnostic to measure the confined alpha particles produced by the fusion reactions.
Energy Technology Data Exchange (ETDEWEB)
Yuan, Xueming [Beijing Univ. of Chemical Technology (China); Duan, Yonghao [Beijing Univ. of Chemical Technology (China); He, Lilin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Singh, Seema [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Simmons, Blake [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Gang [Beijing Univ. of Chemical Technology (China); Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2017-02-08
A systematic study was done to understand interactions among biomass loading during ionic liquid (IL) pretreatment, biomass type and biomass structures. White poplar and eucalyptus samples were pretreated using 1-ethyl-3-methylimidazolium acetate (EmimOAc) at 110 °C for 3 h at biomass loadings of 5, 10, 15, 20 and 25 wt%. All of the samples were chemically characterized and tested for enzymatic hydrolysis. Physical structures including biomass crystallinity and porosity were measured by X-ray diffraction (XRD) and small angle neutron scattering (SANS), respectively. SANS detected pores of radii ranging from ~25 to 625 Å, enabling assessment of contributions of pores with different sizes to increased porosity after pretreatment. Contrasting dependences of sugar conversion on white poplar and eucalyptus as a function of biomass loading were observed and cellulose crystalline structure was found to play an important role.
DEFF Research Database (Denmark)
McNeil, A.; Jonsson, C.J.; Appelfeld, David
2013-01-01
Fenestration attachments are anticipated to produce significant reductions in building energy use because they can be deployed quickly at low-cost. New software tools enable users to assess the building energy impacts of optically complex fenestration systems (CFS) such as shades, Venetian blinds......, or daylighting systems. However, such tools require users to provide bi-directional scattering distribution function (BSDF) data that describe the solar-optical performance of the CFS. A free, open-source Radiance tool genBSDF enables users to generate BSDF data for arbitrary CFS. Prior to genBSDF, BSDF data...... for arbitrary fenestration systems could only be produced using either expensive software or with expensive equipment. genBSDF outputs CFS data in the Window 6 XML file format and so can be used with CFS-enabled software tools to model multi-layered window systems composed of glazing and shading layers...
Derrick, Malcolm; Magill, S; Mikunas, D; Musgrave, B; Okrasinski, J R; Repond, J; Stanek, R; Talaga, R L; Zhang, H; Mattingly, M C K; Anselmo, F; Antonioli, P; Bari, G; Basile, M; Bellagamba, L; Boscherini, D; Bruni, A; Bruni, G; Bruni, P; Cara Romeo, G; Castellini, G; Cifarelli, Luisa; Cindolo, F; Contin, A; Corradi, I; Gialas, I; Giusti, P; Iacobucci, G; Laurenti, G; Levi, G; Margotti, A; Massam, Thomas; Nania, R; Palmonari, F; Pesci, A; Polini, A; Sartorelli, G; Zamora-Garcia, Yu E; Zichichi, Antonino; Amelung, C; Bornheim, A; Crittenden, James Arthur; Deffner, R; Doeker, T; Eckert, M; Feld, L; Frey, A; Geerts, M; Grothe, M; Hartmann, H; Heinloth, K; Heinz, L; Hilger, E; Jakob, H P; Katz, U F; Mengel, S; Paul, E; Pfeiffer, M; Rembser, C; Schramm, D; Stamm, J; Wedemeyer, R; Campbell-Robson, S; Cassidy, A; Cottingham, W N; Dyce, N; Foster, B; George, S; Hayes, M E; Heath, G P; Heath, H F; Piccioni, D; Roff, D G; Tapper, R J; Yoshida, R; Arneodo, M; Ayad, R; Capua, M; Garfagnini, A; Iannotti, L; Schioppa, M; Susinno, G; Caldwell, A; Crtiglia, N; Jing, Z; Liu, W; Parsons, J A; Ritz, S; Sciulli, F; Straub, P B; Wai, L; Yang, S; Zhu, Q; Borzemski, P; Chwastowski, J; Eskreys, Andrzej; Jakubowski, Z; Przybycien, M B; Zachara, M; Zawiejski, L; Adamczyk, L; Bednarek, B; Jelen, K; Kisielewska, D; Kowalski, T; Rulikowska-Zarebska, E; Suszycki, L; Zajac, J; Dulinski, Z; Kotanski, Andrzej; Abbiendi, G; Bauerdick, L A T; Behrens, U; Beier, H; Bienlein, J K; Cases, G; Deppe, O; Desler, K; Drews, G; Flasinski, M; Gilkinson, D J; Glasman, C; Göttlicher, P; GroBe-Knitter, J; Haas, T; Hain, W; Hasell, D; Hessling, H; Iga, Y; Johnson, K F; Joos, P; Kasemann, M; Klanner, Robert; Koch, W; Kötz, U; Kowalski, H; Labs, J; Ladage, A; Löhr, B; Loewe, M; Lüke, D; Mainusch, J; Manczak, O; Milewski, J; Monteiro, T; Ng, J S T; Notz, D; Ohrenberg, K; Piotrzkowski, K; Roco, M T; Rohde, M; Roldán, J; Schneekloth, U; Schulz, W; Selonke, F; Surrow, B; Tassi, E; Vob, T; Westphal, D; Wolf, G; Wollmer, U; Youngman, C; Zeuner, W; Grabosch, H J; Kharchilava, A I; Mari, S M; Meyer, A; Schlenstedt, S; Wulff, N; Barbagli, G; Gallo, E; Pelfer, P G; Maccarrone, G D; De Pasquale, S; Votano, L; Bamberger, Andreas; Eisenhardt, S; Trefzger, T M; Wölfle, S; Bromley, J T; Brook, N H; Bussey, Peter J; Doyle, A T; Saxon, D H; Sinclair, L E; Utley, M L; Wilson, A S; Dannemann, A; Holm, U; Horstmann, D; Sinkus, R; Wick, K; Burow, B D; Hagge, L; Lohrmann, E; Poelz, G; Schott, W; Zetsche, F; Bacon, Trevor C; Brümmer, N; Butterworth, Ian; Harris, V L; Howell, G; Hung, B Y H; Lamberti, L; Long, K R; Miller, D B; Pavel, N; Prinias, A; Sedgbeer, J K; Sideris, Daniel A; Whitfield, A F; Mallik, U; Wang, M Z; Wang, S M; Wu, J T; Cloth, P; Filges, E; An Shiz Hong; Cho, G H; Ko, B J; Lee, S B; Nam, S W; Park, H S; Park, S K; Kartik, S; Kim, H J; McNeil, R R; Metcalf, W; Nadendla, V K; Barreiro, F; Fernández, J P; Graciani, R; Hernández, J M; Hervás, L; Laberga, L; Martínez, M; Del Peso, J; Puga, J; Terrón, J; De Trocóniz, J F; Corriveau, F; Hanna, D S; Hartmann, J; Yung, L W; Lim, J N; Matthews, C G; Patel, P M; Riveline, M; Stairs, D G; Saint-Laurent, M G; Ullmann, R T; Zacek, G; Tsurugai, T; Bashkirov, V; Dolgoshein, B A; Stifutkin, A; Bashindzhagian, G L; Ermolov, P F; Gladilin, L K; Golubkov, Yu A; Kobrin, V D; Korzhavina, I A; Kuzmin, V A; Lukina, O Yu; Proskuryakov, A S; Savin, A A; Shcheglova, L M; Solomin, A N; Zotov, N P; Botje, M; Chlebana, F S; Engelen, J; De Kamps, M; Kooijman, P M; Kruse, A; Van Sighem, A; Tiecke, H G; Vossebeld, Joost Herman; Vreeswijk, M; Wiggers, L; De Wolf, E; Van Woudenberg, R; Acosta, D; Bylsma, B G; Durkin, L S; Gilmore, J; Li Chuan; Ling, T Y; Nylander, P; Park, I H; Romanowsky, T A; Bailey, D S; Cashmore, Roger J; Cooper-Sarkar, A M; Devenish, R C E; Harmew, N; Lancaster, M; Lindemann, L; McFall, J D; Nath, C; Noyes, V A; Quadt, A; Tickner, J R; Uijterwaal, H; Walczak, R; Waters, D S; Wilson, F F; Yip, T; Bertolin, A; Brugnera, R; Carlin, R; Dal Corso, F; De Giorgi, M; Dosselli, U; Limentani, S; Morandin, M; Posocco, M; Stanco, L; Stroili, R; Voci, C; Zuin, F; Bulmahn, J; Feild, R G; Oh, B Y; Whitmore, J; D'Agostini, Giulio; Marini, G; Nigro, A; Hart, J C; McCubbin, N A; Shah, T P; Barberis, E; Dubbs, T; Heusch, C A; Van Hook, M; Lockman, W; Rahn, J T; Sadrozinski, H F W; Seiden, A; Williams, D C; Biltzinger, J; Seifert, R J; Schwarzer, O; Walenta, Albert H; Zech, G; Abramowicz, H; Briskin, G M; Dagan, S; Levy, A; Inuzuka, M; Ishii, T; Kuze, M; Mine, S; Nakao, M; Suzuki, I; Tokushuku, K; Umemori, K; Yamada, S; Yamazaki, Y; Chiba, M; Hamatsu, R; Hirose, T; Homma, K; Kitamura, S; Matsushita, T; Yamauchi, K; Cirio, R; Costa, M; Ferrero, M I; Maselli, S; Peroni, C; Sacchi, R; Solano, A; Staiano, A; Dardo, M; Bailey, D C; Bénard, F; Brkic, M; Hartner, G F; Joo, K K; Levman, G M; Martin, J F; Orr, R S; Polenz, S; Sampson, C R; Simmons, D; Teuscher, R; Butterworth, J M; Catterall, C D; Jones, T W; Kaziewicz, P B; Lane, J B; Saunders, R L; Shulman, J; Sutton, M R; Lu, B; Mo, L W; Bogusz, W; Ciborowski, J; Gajewski, J; Grzelak, G; Kasprzak, M; Krzyzanowski, M; Muchorowski, K; Nowak, R J; Pawlak, J M; Tymieniecka, T; Wróblewski, A K; Zakrzewski, J A; Zarnecki, A F; Adamus, M; Coldewey, C; Eisenberg, Y; Hochman, D; Karshon, U; Revel, D; Zer-Zion, D; Badgett, W F; Breitweg, J; Chapin, D; Cross, R; Dasu, S; Foudas, C; Loveless, R J; Mattingly, S E K; Reeder, D D; Silverstein, S; Smith, W H; Vaiciulis, A W; Wodarczyk, M; Bhadra, S; Cardy, M L; Fagerstroem, C P; Frisken, W R; Furutani, K M; Khakzad, M; Murray, W N; Schmidke, W B
1996-01-01
We present measurements of the structure function \\Ft\\ in e^+p scattering at HERA in the range 3.5\\;\\Gevsq < \\qsd < 5000\\;\\Gevsq. A new reconstruction method has allowed a significant improvement in the resolution of the kinematic variables and an extension of the kinematic region covered by the experiment. At \\qsd < 35 \\;\\Gevsq the range in x now spans 6.3\\cdot 10^{-5} < x < 0.08 providing overlap with measurements from fixed target experiments. At values of Q^2 above 1000 GeV^2 the x range extends to 0.5. Systematic errors below 5\\perc\\ have been achieved for most of the kinematic urray, W N
Yang, Ke R; Matula, Adam J; Kwon, Gihan; Hong, Jiyun; Sheehan, Stafford W; Thomsen, Julianne M; Brudvig, Gary W; Crabtree, Robert H; Tiede, David M; Chen, Lin X; Batista, Victor S
2016-05-04
The solution structures of highly active Ir water-oxidation catalysts are elucidated by combining density functional theory, high-energy X-ray scattering (HEXS), and extended X-ray absorption fine structure (EXAFS) spectroscopy. We find that the catalysts are Ir dimers with mono-μ-O cores and terminal anionic ligands, generated in situ through partial oxidation of a common catalyst precursor. The proposed structures are supported by (1)H and (17)O NMR, EPR, resonance Raman and UV-vis spectra, electrophoresis, etc. Our findings are particularly valuable to understand the mechanism of water oxidation by highly reactive Ir catalysts. Importantly, our DFT-EXAFS-HEXS methodology provides a new in situ technique for characterization of active species in catalytic systems.
[Role of functional imaging in the definition of target volumes for lung cancer radiotherapy].
Thureau, S; Hapdey, S; Vera, P
2016-10-01
Functional imaging with positron emission tomography (PET) is interesting to optimize lung radiotherapy planning, and probably to deliver a heterogeneous dose or adapt the radiation dose during treatment. Only fluorodeoxyglucose (FDG) PET-computed tomography (CT) is validated for staging lung cancer and planning radiotherapy. The optimal segmentation methods remain to be defined as well as the interest of "dose painting" from pre-treatment PET (metabolism: FDG) or hypoxia (fluoromisonidazole: FMISO) and the interest of replanning based on pertherapeutic PET.
[Volume Homeostasis and Renal Function in Rats Exposed to Simulated and Actual Microgravity
Tucker, Bryan J.
1993-01-01
This project has investigated mechanisms that influence alterations in compartmental fluid and electrolyte balance in microgravity and evaluates countermeasures to control renal fluid and electrolyte losses. Determining the alterations due to space flight in fluid compartments and renal function is an important component in understanding long term adaptation to spaceflight and the contribution to post-flight orthostatic intolerance. Four definition phase studies and two studies examining neuro-humoral and vascular mechanisms have been completed.
Boucaud, Ph; Yaouanc, A Le; Micheli, J; Pene, O; Rodriguez-Quintero, J
2009-01-01
We consider the quark mass function which, in spite of the very large Wilson term artefact, can be studied efficiently with clover fermions, by using the quark pseudoscalar vertex and Ward identities. We then study a series of questions about the chiral limit at N_F=0, through the standard chiral extrapolation method. We confirm that the corresponding OPE of the quark mass function, does not work by far at the available momenta ; this seems to be explainable by a recent high order perturbative calculation of the Wilson coefficient which implies very large high order corrections, much larger than in usual QCD perturbative expansions; the gap with the recognized estimate of the condensate remains large, around a factor 2 at the largest momenta available to us (p ~ 6 GeV), showing the need for very high momenta to test OPE in elementary Green functions. We also observe a remarkable property in function of the physical volume: there is a striking discontinuity in the properties of chiral extrapolation around some...
Human factors evaluation of remote afterloading brachytherapy. Volume 2, Function and task analysis
Energy Technology Data Exchange (ETDEWEB)
Callan, J.R.; Gwynne, J.W. III; Kelly, T.T.; Muckler, F.A. [Pacific Science and Engineering Group, San Diego, CA (United States); Saunders, W.M.; Lepage, R.P.; Chin, E. [University of California San Diego Medical Center, CA (United States). Div. of Radiation Oncology; Schoenfeld, I.; Serig, D.I. [Nuclear Regulatory Commission, Washington, DC (United States). Div. of Systems Technology
1995-05-01
A human factors project on the use of nuclear by-product material to treat cancer using remotely operated afterloaders was undertaken by the Nuclear Regulatory Commission. The purpose of the project was to identify factors that contribute to human error in the system for remote afterloading brachytherapy (RAB). This report documents the findings from the first phase of the project, which involved an extensive function and task analysis of RAB. This analysis identified the functions and tasks in RAB, made preliminary estimates of the likelihood of human error in each task, and determined the skills needed to perform each RAB task. The findings of the function and task analysis served as the foundation for the remainder of the project, which evaluated four major aspects of the RAB system linked to human error: human-system interfaces; procedures and practices; training and qualifications of RAB staff; and organizational practices and policies. At its completion, the project identified and prioritized areas for recommended NRC and industry attention based on all of the evaluations and analyses.
$\\Lambda$ Scattering Equations
Gomez, Humberto
2016-01-01
The CHY representation of scattering amplitudes is based on integrals over the moduli space of a punctured sphere. We replace the punctured sphere by a double-cover version. The resulting scattering equations depend on a parameter $\\Lambda$ controlling the opening of a branch cut. The new representation of scattering amplitudes possesses an enhanced redundancy which can be used to fix, modulo branches, the location of four punctures while promoting $\\Lambda$ to a variable. Via residue theorems we show how CHY formulas break up into sums of products of smaller (off-shell) ones times a propagator. This leads to a powerful way of evaluating CHY integrals of generic rational functions, which we call the $\\Lambda$ algorithm.
Directory of Open Access Journals (Sweden)
Silvia Goebel
Full Text Available OBJECTIVES: We examined the effect of Revacept, an Fc fusion protein which is specifically linked to the extracellular domain of glycoprotein VI (GPVI, on thrombus formation after vessel wall injury and on experimental stroke in mice. BACKGROUND: Several antiplatelet drugs for the treatment of myocardial infarction or ischemic stroke with potent anti-ischemic effects have been developed, but all incur a significant risk of bleeding. METHODS: Platelet adhesion and thrombus formation after endothelial injury was monitored in the carotid artery by intra-vital fluorescence microscopy. The morphological and clinical consequences of stroke were investigated in a mouse model with a one hour-occlusion of the middle cerebral artery. RESULTS: Thrombus formation was significantly decreased after endothelial injury by 1 mg/kg Revacept i.v., compared to Fc only. 1 mg/kg Revacept i.v. applied in mice with ischemic stroke immediately before reperfusion significantly improved functional outcome, cerebral infarct size and edema compared to Fc only. Also treatment with 10 mg/kg rtPA was effective, and functional outcome was similar in both treatment groups. The combination of Revacept with rtPA leads to increased reperfusion compared to treatment with either agent alone. In contrast to rtPA, however, there were no signs of increased intracranial bleeding with Revacept. Both rtPA and Revacept improved survival after stroke compared to placebo treatment. Revacept and vWF bind to collagen and Revacept competitively prevented the binding of vWF to collagen. CONCLUSIONS: Revacept reduces arterial thrombus formation, reduces cerebral infarct size and edema after ischemic stroke, improves functional and prognostic outcome without intracranial bleeding. Revacept not only prevents GPVI-mediated, but probably also vWF-mediated platelet adhesion and aggregate formation. Therefore Revacept might be a potent and safe tool to treat ischemic complications of stroke.
Stochastic processes and functional analysis a volume of recent advances in honor of M. M. Rao
Krinik, Alan C
2004-01-01
This extraordinary compilation is an expansion of the recent American Mathematical Society Special Session celebrating M. M. Rao's distinguished career and includes most of the presented papers as well as ancillary contributions from session invitees. This book shows the effectiveness of abstract analysis for solving fundamental problems of stochastic theory, specifically the use of functional analytic methods for elucidating stochastic processes, as made manifest in M. M. Rao's prolific research achievements. Featuring a biography of M. M. Rao, a complete bibliography of his published works,
Glass, John O.; Mulhern, Raymond K.; White, Holly A.; Wilkinson, Gina M.; Reddick, Wilburn E.
2003-05-01
Quantitative assessment of MR examinations in 37 survivors of childhood cancer treated with central nervous system prophylaxis revealed that normal appearing white matter (NAWM) volume is associated with attention-related problems, localized specifically in the right prefrontal region. T1-, T2-, and PD-weighted images were segmented and divided into pre-frontal, frontal, parietal/temporal, and parietal/occipital regions for each hemisphere. These eight regions were analyzed in five slices centered at the level of the basal ganglia. The patient's age at diagnosis and time elapsed from diagnosis were used as covariates in the regressions. Attentional measures showed significant deficiency when compared to age and gender normative values. Total, frontal and/or prefrontal NAWM volumes from the range of slices examined were significantly associated with 5 of the 8 attentional measures. The frontal/prefrontal region of the brain is associated with executive functioning tasks and could potentially be spared as much as possible during therapy planning. The results of the present study further support the contention that NAWM is an important substrate for treatment-induced neurocognitive problems among survivors of malignant brain tumors of childhood.
Giordano, M; Ciarambino, T; Gesuè, L; Castellino, P; De Simone, M; Rinaldi, G; D'Amora, M; Zito, G; Paolisso, G; Coppola, L
2009-10-01
In Type 2 diabetes, it is not clear if renal size is constantly related to the glomerular filtration rate. In addition, it is not known if kidney volume (KV) is associated with an increased urinary albumin and IgG excretion. The relationship between kidney volume, creatinine clearance (CrCl), urinary albumin and IgG excretion in 95 Type 2 diabetic patients with different stages of nephropathy (1 - 4 Stage sec NKDF-QD) was elevated and compared to 85 non-diabetic subjects with similar degree of kidney function. In Type 2 diabetic patients the KV/CrCl ratio was increased, in comparison with the control subjects, from about 15% in Stage 1 to 53% in Stage 4. In T2D subjects, significant correlations were found between KV and urinary albumin excretion (r = 0.665, p < 0.05), and between KV and urinary IgG excretion (r = 0.800, p < 0.001). The present study finds that Type 2 diabetic subjects, are characterized by an increased ratio between KV/CrCl, throughout the different progressive stages of nephropathy. In Type 2 diabetes relationships between KV and urinary albumin and between KV and IgG excretion also were found to be significant, suggesting a role for the impaired size selectivity of proteinuria as a possible determinant of KV.
Extinction-Optimized Volume Illumination.
Ament, Marco; Zirr, Tobias; Dachsbacher, Carsten
2016-05-16
We present a novel method to optimize the attenuation of light for the single scattering model in direct volume rendering. A common problem of single scattering is the high dynamic range between lit and shadowed regions due to the exponential attenuation of light along a ray. Moreover, light is often attenuated too strong between a sample point and the camera, hampering the visibility of important features. Our algorithm employs an importance function to selectively illuminate important structures and make them visible from the camera. With the importance function, more light can be transmitted to the features of interest, while contextual structures cast shadows which provide visual cues for perception of depth. At the same time, more scattered light is transmitted from the sample point to the camera to improve the primary visibility of important features. We formulate a minimization problem that automatically determines the extinction along a view or shadow ray to obtain a good balance between sufficient transmittance and attenuation. In contrast to previous approaches, we do not require a computationally expensive solution of a global optimization, but instead provide a closed-form solution for each sampled extinction value along a view or shadow ray and thus achieve interactive performance.
Energy Technology Data Exchange (ETDEWEB)
Friedrich, Harald [Technische Univ. Muenchen, Garching (Germany). Physik-Department
2013-08-01
Written by the author of the widely acclaimed textbook. Theoretical Atomic Physics Includes sections on quantum reflection, tunable Feshbach resonances and Efimov states. Useful for advanced students and researchers. This book presents a concise and modern coverage of scattering theory. It is motivated by the fact that experimental advances have shifted and broadened the scope of applications where concepts from scattering theory are used, e.g. to the field of ultracold atoms and molecules, which has been experiencing enormous growth in recent years, largely triggered by the successful realization of Bose-Einstein condensates of dilute atomic gases in 1995. In the present treatment, special attention is given to the role played by the long-range behaviour of the projectile-target interaction, and a theory is developed, which is well suited to describe near-threshold bound and continuum states in realistic binary systems such as diatomic molecules or molecular ions. The level of abstraction is kept as low as at all possible, and deeper questions related to mathematical foundations of scattering theory are passed by. The book should be understandable for anyone with a basic knowledge of nonrelativistic quantum mechanics. It is intended for advanced students and researchers, and it is hoped that it will be useful for theorists and experimentalists alike.
Friedrich, Harald
2016-01-01
This corrected and updated second edition of "Scattering Theory" presents a concise and modern coverage of the subject. In the present treatment, special attention is given to the role played by the long-range behaviour of the projectile-target interaction, and a theory is developed, which is well suited to describe near-threshold bound and continuum states in realistic binary systems such as diatomic molecules or molecular ions. It is motivated by the fact that experimental advances have shifted and broadened the scope of applications where concepts from scattering theory are used, e.g. to the field of ultracold atoms and molecules, which has been experiencing enormous growth in recent years, largely triggered by the successful realization of Bose-Einstein condensates of dilute atomic gases in 1995. The book contains sections on special topics such as near-threshold quantization, quantum reflection, Feshbach resonances and the quantum description of scattering in two dimensions. The level of abstraction is k...
Relation of left ventricular function, mass, and volume to NT-proBNP in type 1 diabetic patients
DEFF Research Database (Denmark)
Astrup, A.S.; Kim, W.Y.; Tarnow, L.;
2008-01-01
OBJECTIVES: To measure left ventricular mass (LVM), left ventricular volumes, and left ventricular function (LVF) in a cohort of type 1 diabetic patients and to correlate measures of imaging to NH(2)-terminal pro-brain natriuretic peptide (NT-proBNP). RESEARCH DESIGN AND METHODS: In a cross......-sectional study, all patients with type 1 diabetes underwent cardiovascular magnetic resonance imaging. We included 63 patients with diabetic nephropathy and 73 patients with normoalbuminuria. RESULTS: All patients had normal global LVF. LVM was increased in patients with diabetic nephropathy compared...... is identified in asymptomatic type 1 diabetic patients with nephropathy compared with normoalbuminuric patients. Elevated levels of NT-proBNP were associated with increased LVM, which are both markers of increased cardiovascular risk Udgivelsesdato: 2008/5...
Nadège Ilembe Badouna, Audrey; Veres, Cristina; Haddy, Nadia; Bidault, François; Lefkopoulos, Dimitri; Chavaudra, Jean; Bridier, André; de Vathaire, Florent; Diallo, Ibrahima
2012-01-01
The aim of this paper was to determine anthropometric parameters leading to the least uncertain estimate of heart size when connecting a computational phantom to an external beam radiation therapy (EBRT) patient. From computed tomography images, we segmented the heart and calculated its total volume (THV) in a population of 270 EBRT patients of both sexes, aged 0.7-83 years. Our data were fitted using logistic growth functions. The patient age, height, weight, body mass index and body surface area (BSA) were used as explanatory variables. For both genders, good fits were obtained with both weight (R2 = 0.89 for males and 0.83 for females) and BSA (R2 = 0.90 for males and 0.84 for females). These results demonstrate that, among anthropometric parameters, weight plays an important role in predicting THV. These findings should be taken into account when assigning a computational phantom to a patient.
Institute of Scientific and Technical Information of China (English)
Liang Jun
2007-01-01
In this paper, the dynamic behavior of a permeable crack in functionally graded piezoelectric/piezomagnetic materials is investigated. To make the analysis tractable, it is assumed that the material properties vary exponentially with the coordinate parallel to the crack. By using the Fourier transform, the problem can be solved with the help of a pair of dual integral equations in which the unknown is the jump of displacements across the crack surfaces. These equations are solved to obtain the relations between the electric filed, the magnetic flux field and the dynamic stress field near the crack tips using the Schmidt method. Numerical examples are provided to show the effect pf the functionally graded parameter and the circular frequency of the incident waves upon the stress, the electric displacement and the magnetic flux intensity factors of the crack.
Energy Technology Data Exchange (ETDEWEB)
Gaerdin, A.; Bruno, J.; Movin, T.; Kristoffersen-Wiberg, M.; Shalabi, A. [Karolinska Univ. Hospital, Stockholm (Sweden). Depts. of Radiology and Orthopedics
2006-09-15
Purpose: To depict abnormal tendon matrix composition using magnetic resonance imaging (MRI) in chronic Achilles tendinopathy, and correlate intratendinous signal alterations to pain and functional impairment. Material and Methods: MRI of the Achilles tendon was performed on 25 patients with chronic Achilles tendinopathy (median age 50, range 37-71 years). All patients suffered from pain in the mid-portion of the Achilles tendon. Intratendinous signal was calculated from five different sagittal sequences, using a computerized 3D seed-growing technique. Pain and functional impairment were evaluated using a questionnaire completed by patients. Results: Severity of pain and functional impairment correlated to increased mean intratendinous signal in the painful tendon in all MR sequences (P 0.05). Difference in mean intratendinous signal between symptomatic and contralateral asymptomatic tendons was highly significant in all sequences (P <0.05) except on T2-weighted images (P = 0.6). Conclusion: Severity of pain and disability correlated to increased MR signal rather than to tendon volume in patients with unilateral mid-portion chronic Achilles tendinopathy.
Nejad, S. Mohammad Moosavi; Khanpour, Hamzeh; Tehrani, S. Atashbar; Mahdavi, Mahdi
2016-10-01
We present a detailed QCD analysis of nucleon structure functions x F3(x ,Q2) , based on Laplace transforms and the Jacobi polynomials approach. The analysis corresponds to the next-to-leading order and next-to-next-to-leading order approximations of perturbative QCD. The Laplace transform technique, as an exact analytical solution, is used for the solution of nonsinglet Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations at low- and large-x values. The extracted results are used as input to obtain the x and Q2 evolution of x F3(x ,Q2) structure functions using the Jacobi polynomials approach. In our work, the values of the typical QCD scale ΛMS¯ (nf) and the strong coupling constant αs(MZ2) are determined for four quark flavors (nf=4 ) as well. A careful estimation of the uncertainties shall be performed using the Hessian method for the valence-quark distributions, originating from the experimental errors. We compare our valence-quark parton distribution functions sets with those of other collaborations, in particular with the CT14, MMHT14, and NNPDF sets, which are contemporary with the present analysis. The obtained results from the analysis are in good agreement with those from the literature.
DEFF Research Database (Denmark)
Therkelsen, Susette Krohn; Groenning, Bjoern Aaris; Svendsen, Jesper Hastrup
2006-01-01
Atrial fibrillation (AF) is the most common cardiac arrhythmia and 25% of those >40 years old will experience AF. Left atrial size and left ventricular function are independently related to cardiovascular morbidity and mortality. Our aim was to evaluate cardiac volume and function using magnetic ...
DEFF Research Database (Denmark)
Therkelsen, Susette Krohn; Groenning, Bjoern Aaris; Svendsen, Jesper Hastrup
2006-01-01
Atrial fibrillation (AF) is the most common cardiac arrhythmia and 25% of those >40 years old will experience AF. Left atrial size and left ventricular function are independently related to cardiovascular morbidity and mortality. Our aim was to evaluate cardiac volume and function using magnetic ...
Davis, Timur D.
2011-12-01
In the development of new medicinal products, poor oral bioavailability, due to the low solubilities of many active pharmaceutical ingredients (APIs), is increasingly a barrier for treatments to be administered using tablet or capsule formulations and one of the main challenges facing the pharmaceutical industry. Non-crystalline phases such as the amorphous and nanostructured states can confer increased solubility to a drug, and therefore, have recently garnered a lot of interest from pharmaceutical researchers. However, little is known about local ordering in non-crystalline pharmaceuticals due to the lack of reliable experimental probes, hindering the clinical application of these compounds. The powerful tools of crystallography begin to lose their potency for structures on the nanoscale; conventional X-ray powder diffraction (XRPD) patterns become broad and featureless in these cases and are not useful for differentiating between different local molecular packing arrangements. In this thesis, we introduce the use of high energy X-rays coupled with total scattering pair distribution function (TSPDF) and fingerprinting analysis to investigate the local structures of non-crystalline pharmaceutical compounds. The high energy X-rays allow us to experimentally collect diffuse scattering intensities, which contain information about a sample's local ordering, in addition to the Bragg scattering available in conventional XRPD experiments, while the TSPDF allows us to view the intra- and inter-molecular correlations in real space. The goal of this study was to address some fundamental problems involving fingerprinting non-crystalline APIs using TSPDF in order to lay the groundwork for the proper use of the technique by the pharmaceutical community. We achieved this by developing the methodology as well as the exploring the scientific implications. On the methodology side, we introduced PDFGetX3, a new software program for calculating TSPDFs that simplifies the procedure
Szmulowicz, F.; Brown, G. J.
2013-01-01
Superlattice transport has acquired new relevance owing to the current interest in InAs/GaSb and other superlattices (SL) for third-generation infrared detector focal plane arrays. Interface-roughness scattering (IRS) is known to limit carrier mobilities at low temperatures. Whereas horizontal (in-plane) transport measurements are standard, perpendicular transport measurements (across SL layers)—the ones relevant to the operation of infrared sensors—are non-routine and seldom performed; vertical SL transport is also less well studied theoretically. Therefore, we extend our previous work on low-temperature SL transport by studying horizontal and vertical IRS-limited transport in InAs/GaSb SLs as a function of temperature, SL parameters, and the degree of roughness. Electron mobilities are calculated by solving the Boltzmann equation with temperature-dependent bands and carrier screening, and the results are discussed by analyzing the behavior of the relaxation rates and spectral mobilities, defined as mobilities as a function of carrier energy. New computational tools are devised to handle the implicit integral equation for the horizontal relaxation rates. We find that the behavior of the relaxation rates and spectral mobilities undergoes a change for energies below and above the conduction band bandwidth, which dictates the ultimate behavior of mobilities as a function of temperature. The calculated mobilities are found to display a rich variety of behaviors as a function of temperature, either increasing, decreasing, or remaining relatively constant, depending on the correlation length of interface roughness, Λ, and the conduction band bandwidth. Since the horizontal mobility is a double-valued function of Λ, the temperature dependence of mobilities can be used to eliminate this indeterminacy in order to assess the degree of interface roughness.
Polarized lepton-nucleon scattering
Energy Technology Data Exchange (ETDEWEB)
Hughes, E.
1994-02-01
Deep inelastic polarized lepton-nucleon scattering is reviewed in three lectures. The first lecture covers the polarized deep inelastic scattering formalism and foundational theoretical work. The second lecture describes the nucleon spin structure function experiments that have been performed up through 1993. The third lecture discusses implication of the results and future experiments aimed at high-precision measurements of the nucleon spin structure functions.
Mortality and functional performance in severe emphysema after lung volume reduction or transplant.
Weinstein, Michael S; Martin, Ubaldo J; Crookshank, Aaron D; Chatila, Wissam; Vance, Gwendolyn B; Gaughan, John P; Furukawa, Satoshi; Criner, Gerard J
2007-03-01
The purpose of this endeavor is to compare the morbidity, mortality and costs of LVRS versus transplantation in severe emphysema. This was a retrospective review of severe emphysema patients who received LVRS (n = 70) from 1994-1999, or transplant (n = 87) from 1994-2004. Change in functional status was calculated by the change in modified BODE (mBODE) score. Financial data included physician, hospital and medication costs. Preoperatively, there was no significant difference between the transplant and LVRS groups (mean +/- SD) in age (57.7 +/- 5.7 vs. 59.1 +/- 8.3 years), BMI, Borg dyspnea score, 6-minute walk distance or mBODE (10.4 +/- 2.6 vs. 9.6 +/- 2.7, p = 0.4). Preoperatively, FEV1% (23.6 +/- 8.5 vs. 31.9 +/- 17.7, p = 0.008) was significantly lower in the transplant group. One year post-operatively, transplantation patients had a significantly greater improvement in mBODE (-5.7 vs. -2.0, p = 0.0004), FEV1% (43.4 vs. 2.2%, p = 0.0004) and Borg score (-3.0 vs. -1.4, p = 0.04). Transplantation patients had lower long-term survival compared to LVRS patients (p = 0.01). The only variable that affected survival was type of surgery favoring LVRS (hazard ratio 1.7, 95% confidence limits 1.05-2.77). During a mean follow-up of 2.4 +/- 2.5 years after transplant and 5.0 +/- 3.1 years after LVRS, transplantation mean total costs were greater ($381,732 vs. $140,637, p improvement in airflow obstruction, dyspnea, exercise tolerance, and mBODE score, but costs more and carries greater mortality.
Nejad, S Mohammad Moosavi; Tehrani, S Atashbar; Mahdavi, Mahdi
2016-01-01
We present a detailed QCD analysis of nucleon structure functions $xF_3 (x, Q^2)$, based on Laplace transforms and Jacobi polynomials approach. The analysis corresponds to the next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) approximation of perturbative QCD. The Laplace transform technique, as an exact analytical solution, is used for the solution of nonsinglet DGLAP evolution equations at low- and large-$x$ values. The extracted results are used as input to obtain the $x$ and Q$^2$ evolution of $xF_3(x, Q^2)$ structure functions using the Jacobi polynomials approach. In our work, the values of the typical QCD scale $\\Lambda_{\\overline{\\rm MS}}^{(n_f)}$ and the strong coupling constant $\\alpha_s(M_Z^2)$ are determined for four quark flavors ($n_f=4$) as well. A careful estimation of the uncertainties shall be performed using the Hessian method for the valence-quark distributions, originating from the experimental errors. We compare our valence-quark PDFs sets with those of other collabora...
Energy Technology Data Exchange (ETDEWEB)
Rolfe, R.M.
1976-12-01
The goal of the research was to investigate proton scattering on nuclei at intermediate energies and in particular to investigate proton scattering on helium. A theoretical investigation of the helium nucleus and the nature of the intermediate energy interaction, design and optimization of an energy-loss spectrometer facility for proton-nucleus scattering, and the unique superfluid helium target and experimental design are discussed.
Directory of Open Access Journals (Sweden)
Tian Tian
Full Text Available The effect of catechol-O-methyltransferase (COMT Val158Met polymorphism on brain structure and function has been previously investigated separately and regionally; this prevents us from obtaining a full picture of the effect of this gene variant. Additionally, gender difference must not be overlooked because estrogen exerts an interfering effect on COMT activity. We examined 323 young healthy Chinese Han subjects and analyzed the gray matter volume (GMV differences between Val/Val individuals and Met carriers in a voxel-wise manner throughout the whole brain. We were interested in genotype effects and genotype × gender interactions. We then extracted these brain regions with GMV differences as seeds to compute resting-state functional connectivity (rsFC with the rest of the brain; we also tested the genotypic differences and gender interactions in the rsFCs. Val/Val individuals showed decreased GMV in the posterior cingulate cortex (PCC compared with Met carriers; decreased GMV in the medial superior frontal gyrus (mSFG was found only in male Val/Val subjects. The rsFC analysis revealed that both the PCC and mSFG were functionally correlated with brain regions of the default mode network (DMN. Both of these regions showed decreased rsFCs with different parts of the frontopolar cortex of the DMN in Val/Val individuals than Met carriers. Our findings suggest that the COMT Val158Met polymorphism modulates both the structure and functional connectivity within the DMN and that gender interactions should be considered in studies of the effect of this genetic variant, especially those involving prefrontal morphology.
Jung, Yookyung; Tam, Joshua; Jalian, H. Ray; Anderson, R. Rox; Evans, Conor L.
2014-01-01
Sebaceous glands perform complex functions, and are centrally involved in the pathogenesis of acne vulgaris. Current techniques for studying sebaceous glands are mostly static in nature, whereas the gland’s main function – excretion of sebum via the holocrine mechanism – can only be evaluated over time. We present a longitudinal, real-time alternative – the in vivo, label-free imaging of sebaceous glands using Coherent Anti-Stokes Raman Scattering (CARS) microscopy, which is used to selectively visualize lipids. In mouse ears, CARS microscopy revealed dynamic changes in sebaceous glands during the holocrine secretion process, as well as in response to damage to the glands caused by cooling. Detailed gland structure, plus the active migration of individual sebocytes and cohorts of sebocytes were measured. Cooling produced characteristic changes in sebocyte structure and migration. This study demonstrates that CARS microscopy is a promising tool for studying the sebaceous gland and its associated disorders in three-dimensions in vivo. PMID:25026458
Skarpalezos, Loukas; Argyrakis, Panos; Vikhrenko, Vyacheslav S.
2014-05-01
We investigate the self-intermediate scattering function (SISF) in a three-dimensional (3D) cubic lattice fluid (interacting lattice gas) with attractive nearest-neighbor interparticle interactions at a temperature slightly above the critical one by means of Monte Carlo simulations. A special representation of SISF as an exponent of the mean tracer diffusion coefficient multiplied by the geometrical factor and time is considered to highlight memory effects that are included in time and wave-vector dependence of the diffusion coefficient. An analytical expression for the diffusion coefficient is suggested to reproduce the simulation data. It is shown that the particles' mean-square displacement is equal to the time integral of the diffusion coefficient. We make a comparison with the previously considered 2D system on a square lattice. The main difference with the two-dimensional case is that the time dependence of particular characteristics of the tracer diffusion coefficient in the 3D case cannot be described by exponentially decreasing functions, but requires using stretched exponentials with rather small values of exponents, of the order of 0.2. The hydrodynamic values of the tracer diffusion coefficient (in the limit of large times and small wave vectors) defined through SIFS simulation results agree well with the results of its direct determination by the mean-square displacement of the particles in the entire range of concentrations and temperatures.
Superradiant Forward Scattering in Multiple Scattering
Chabe, Julien; Bienaime, Tom; Bachelard, Romain; Piovella, Nicola; Kaiser, Robin
2012-01-01
We report on an interference effect in multiple scattering by resonant scatterers resulting in enhanced forward scattering, violating Ohm's law for photons. The underlying mechanism of this wave effect is superradiance, which we have investigated using cold atoms as a toy model. We present numerical and experimental evidences for this superradiant forward scattering, which is robust against disorder and configuration averaging.
Resonances in Coupled-Channel Scattering
Wilson, David J
2016-01-01
Excited hadrons are seen as resonances in the scattering of lighter stable hadrons like $\\pi$, $K$ and $\\eta$. Many decay into multiple final states necessitating coupled-channel analyses. Recently it has become possible to obtain coupled-channel scattering amplitudes from lattice QCD. Using large diverse bases of operators it is possible to obtain reliable finite volume spectra at energies where multiple channels are open. Utilising the finite volume formalism proposed by L\\"uscher and extended by several others, scattering amplitudes can be extracted from the finite volume spectra. Recent applications will be discussed where the energy dependence of scattering amplitudes is mapped out in several quantum numbers. These are then continued to complex energies to extract resonance poles and couplings.
Scattering intensity limit value at very small angles
Ciccariello, Salvino
2016-01-01
The existence of the limit of a sample scattering intensity, as the scattering vector approaches zero, requires and is ensured by the property that the mean value of the scattering density fluctuation over volume $V$ asymptotically behaves, at large $V$s, as $\