Small-angle neutron scattering studies of sodium butyl benzene

Indian Academy of Sciences (India)

Na-NBBS), in aqueous solutions is investigated by small-angle neutron scattering (SANS). Nearly ellipsoidal aggregates of Na-NBBS at concentrations well above its minimum hydrotrope concentration were detected by SANS. The hydrotrope ...

The new 'BerSANS-PC' software for reduction and treatment of small angle neutron scattering data

International Nuclear Information System (INIS)

Keiderling, U.

2002-01-01

Measurements on small angle neutron scattering (SANS) instruments are typically characterized by a large number of samples, short measurement times for the individual samples, and a frequent change of visiting scientist groups. Besides this, recent advances in instrumentation have led to more frequent measurements of kinetic sequences and a growing interest in analyzing two-dimensional scattering data, these requiring special software tools that enable the users to extract physically relevant information from the scattering data with a minimum of effort. The new 'BerSANS-PC' data-processing software has been developed at the Hahn-Meitner-Institut (HMI) in Berlin, Germany, to meet these requirements and to support an efficiently working guest-user service. Comprising some basic functions of the 'BerSANS' program available at the HMI and other institutes in the past, BerSANS-PC is a completely new development for network-independent use on local PCs with a full-feature graphical interface. (orig.)

Implications of Microwave Holography Using Minimum Required Frequency Samples for Weakly- and Strongly-Scattering Indications

Science.gov (United States)

Fallahpour, M.; Case, J. T.; Kharkovsky, S.; Zoughi, R.

2010-01-01

Microwave imaging techniques, an integral component of nondestructive testing and evaluation (NDTE), have received significant attention in the past decade. These techniques have included the implementation of synthetic aperture focusing (SAF) algorithms for obtaining high spatial resolution images. The next important step in these developments is the implementation of 3-D holographic imaging algorithms. These are well-known wideband imaging technique requiring a swept-frequency (i.e., wideband), which unlike SAF that is a single frequency technique, are not easily performed on a real-time basis. This is due to the fact that a significant number of data points (in the frequency domain) must be obtained within the frequency band of interest. This not only makes for a complex imaging system design, it also significantly increases the image-production time. Consequently in an attempt to reduce the measurement time and system complexity, an investigation was conducted to determine the minimum required number of frequency samples needed to image a specific object while preserving a desired maximum measurement range and range resolution. To this end the 3-D holographic algorithm was modified to use properlyinterpolated frequency data. Measurements of the complex reflection coefficient for several samples were conducted using a swept-frequency approach. Subsequently, holographical images were generated using data containing a relatively large number of frequency samples and were compared with images generated by the reduced data set data. Quantitative metrics such as average, contrast, and signal-to-noise ratio were used to evaluate the quality of images generated using reduced data sets. Furthermore, this approach was applied to both weakly- and strongly-scattering indications. This paper presents the methods used and the results of this investigation.

Phase separation temperatures of a liquid mixture: Dynamic light scattering technique

International Nuclear Information System (INIS)

Dangudom, K.; Wongtawatnugool, C.; Lacharojana, S.

2010-01-01

Light scattering intensity measurements and photon correlation spectroscopy (PCS) techniques were employed in an investigation of liquid-liquid phase separation behaviour of a mixture of cyclohexane and methanol at seven different compositions. It was found that, except for one composition (29% methanol), the temperature at which the scattering intensity was a maximum did not coincide with the one where the diffusion coefficient was a minimum, as would be for the case of a vapour-liquid system. The difference may be explained in terms of the local density fluctuation and the random walk problem responsible for the peak intensity and the minimum in the diffusion coefficient, respectively. The definition of phase separation temperature, as determined from diffusion process, was also proposed in this work.

An experimental study of the scatter correction by using a beam-stop-array algorithm with digital breast tomosynthesis

Energy Technology Data Exchange (ETDEWEB)

Kim, Ye-Seul; Park, Hye-Suk; Kim, Hee-Joung [Yonsei University, Wonju (Korea, Republic of); Choi, Young-Wook; Choi, Jae-Gu [Korea Electrotechnology Research Institute, Ansan (Korea, Republic of)

2014-12-15

Digital breast tomosynthesis (DBT) is a technique that was developed to overcome the limitations of conventional digital mammography by reconstructing slices through the breast from projections acquired at different angles. In developing and optimizing DBT, The x-ray scatter reduction technique remains a significant challenge due to projection geometry and radiation dose limitations. The most common approach to scatter reduction is a beam-stop-array (BSA) algorithm; however, this method raises concerns regarding the additional exposure involved in acquiring the scatter distribution. The compressed breast is roughly symmetric, and the scatter profiles from projections acquired at axially opposite angles are similar to mirror images. The purpose of this study was to apply the BSA algorithm with only two scans with a beam stop array, which estimates the scatter distribution with minimum additional exposure. The results of the scatter correction with angular interpolation were comparable to those of the scatter correction with all scatter distributions at each angle. The exposure increase was less than 13%. This study demonstrated the influence of the scatter correction obtained by using the BSA algorithm with minimum exposure, which indicates its potential for practical applications.

Scattering of aerosol particles by a Hermite-Gaussian beam in marine atmosphere.

Science.gov (United States)

Huang, Qingqing; Cheng, Mingjian; Guo, Lixin; Li, Jiangting; Yan, Xu; Liu, Songhua

2017-07-01

Based on the complex-source-point method and the generalized Lorenz-Mie theory, the scattering properties and polarization of aerosol particles by a Hermite-Gaussian (HG) beam in marine atmosphere is investigated. The influences of beam mode, beam width, and humidity on the scattered field are analyzed numerically. Results indicate that when the number of HG beam modes u (v) increase, the radar cross section of aerosol particles alternating appears at maximum and minimum values in the forward and backward scattering, respectively, because of the special petal-shaped distribution of the HG beam. The forward and backward scattering of aerosol particles decreases with the increase in beam waist. When beam waist is less than the radius of the aerosol particle, a minimum value is observed in the forward direction. The scattering properties of aerosol particles by the HG beam are more sensitive to the change in relative humidity compared with those by the plane wave and the Gaussian beam (GB). The HG beam shows superiority over the plane wave and the GB in detecting changes in the relative humidity of marine atmosphere aerosol. The effects of relative humidity on the polarization of the HG beam have been numerically analyzed in detail.

Scattering-Type Surface-Plasmon-Resonance Biosensors

Science.gov (United States)

Wang, Yu; Pain, Bedabrata; Cunningham, Thomas; Seshadri, Suresh

2005-01-01

Biosensors of a proposed type would exploit scattering of light by surface plasmon resonance (SPR). Related prior biosensors exploit absorption of light by SPR. Relative to the prior SPR biosensors, the proposed SPR biosensors would offer greater sensitivity in some cases, enough sensitivity to detect bioparticles having dimensions as small as nanometers. A surface plasmon wave can be described as a light-induced collective oscillation in electron density at the interface between a metal and a dielectric. At SPR, most incident photons are either absorbed or scattered at the metal/dielectric interface and, consequently, reflected light is greatly attenuated. The resonance wavelength and angle of incidence depend upon the permittivities of the metal and dielectric. An SPR sensor of the type most widely used heretofore includes a gold film coated with a ligand a substance that binds analyte molecules. The gold film is thin enough to support evanescent-wave coupling through its thickness. The change in the effective index of refraction at the surface, and thus the change in the SPR response, increases with the number of bound analyte molecules. The device is illuminated at a fixed wavelength, and the intensity of light reflected from the gold surface opposite the ligand-coated surface is measured as a function of the angle of incidence. From these measurements, the angle of minimum reflection intensity is determined

Useful variational principle for the scattering length for the target ground-state wave function imprecisely known

International Nuclear Information System (INIS)

Blau, R.; Rosenberg, L.; Spruch, L.

1977-01-01

A minimum principle for the calculation of the scattering length, applicable when the ground-state wave function of the target system is known precisely, has been available for some time. When, as is almost always the case, the target wave function is imprecisely known, a minimum principle is available but the simple minimum principle noted above is not applicable. Further, as recent calculations show, numerical instabilities usually arise which severely limit the utility of even an ordinary variational approach. The difficulty, which can be traced to the appearance of singularities in the variational construction, is here removed through the introduction of a minimum principle, not for the true scattering length, but for one associated with a closely connected problem. This guarantees that no instability difficulties can arise as the trial scattering wave function and the trial target wave function are improved. The calculations are little different from those required when the target ground-state wave function is known, and, in fact, the original version of the minimum principle is recovered as the trial target wave function becomes exact. A careful discussion is given of the types of problems to which the method can be applied. In particular, the effects of the Pauli principle, and the existence of a finite number of composite bound states, can be accounted for

Positron-atom scattering using a modified Kohn variational technique

International Nuclear Information System (INIS)

Page, B.A.P.

1976-01-01

An analysis of the zero-energy positron-hydrogen and positron-helium systems using various approximations to the target ground-state wavefunction is presented. A modification of the normal Kohn variational method is used in which a quantity, asub(Q), which becomes the Kohn scattering length if the target wavefunction is exact, is related to the trial wavefunction psisub(t) through an integral expression. By comparing the results obtained with the definitive values for the positron-hydrogen system, it is conjectured that if the values of asub(Q) display a local minimum when all the nonlinear parameters of psisub(t) are varied, then this local minimum of asub(Q) is an upper bound on the exact scattering length. Using this criterion to analyse the positron-helium results, it is concluded that this method may be considered as an alternative to the 'method of models' procedure, since both methods give similar results. (author)

Gluon exchange in elastic hadron scattering

International Nuclear Information System (INIS)

Jenkovszky, L.L.; Paccanoni, F.; Chikovani, Z.E.

1991-01-01

It is generally accepted that the Pomeron, which determines the long-range component of the strong interaction, corresponds to exchange of gluons with the corresponding quantum numbers (the minimum number of such gluons is two). The C-odd partner of the Pomeron, the odderon, corresponds to exchange of an odd number of gluons (three or more). By means of a model of the nonperturbative gluon propagator, restrictions are obtained on the parameters of two-gluon (Pomeron) and three-gluon (odderon) exchange in hadron scattering. In the framework of this model an interpretation is proposed for the various asymptotic regimes in the behavior of the total cross section and of the differential cross section of elastic scattering at high energies

Binding and Pauli principle corrections in subthreshold pion-nucleus scattering

International Nuclear Information System (INIS)

Kam, J. de

1981-01-01

In this investigation I develop a three-body model for the single scattering optical potential in which the nucleon binding and the Pauli principle are accounted for. A unitarity pole approximation is used for the nucleon-core interaction. Calculations are presented for the π- 4 He elastic scattering cross sections at energies below the inelastic threshold and for the real part of the π- 4 He scattering length by solving the three-body equations. Off-shell kinematics and the Pauli principle are carefully taken into account. The binding correction and the Pauli principle correction each have an important effect on the differential cross sections and the scattering length. However, large cancellations occur between these two effects. I find an increase in the π- 4 He scattering length by 100%; an increase in the cross sections by 20-30% and shift of the minimum in π - - 4 He scattering to forward angles by 10 0 . (orig.)

Deuteron polarizability and S-wave π+d scattering at energies below 1 keV

International Nuclear Information System (INIS)

Pupyshev, V.V.

1987-01-01

The influence of deuteron polarizability on the S-wave π + d-scattering in a low-energy limit is explored in the framework of the variable phase method. It is shown that the nonoscillating part of the S-wave cross section of π + d-scattering has a deep and sharp minimum in the energy region ∼ 0.4 keV

Interference of Coulomb and nuclear excitation in inelastic scattering of 20Ne from 40Ca

International Nuclear Information System (INIS)

Ratel, Guy.

1976-01-01

Angular distributions at 54 and 63MeV and excitation functions from 35 to 95MeV for the elastic and inelastic scattering of 20 Ne by 40 Ca have been measured. Experimental data for the inelastic scattering leading to the 20 Ne (2 + , 1.63MeV) state show a characteristic minimum for the angular distributions and excitation functions. This phenomenon was explained by an interference effect between Coulomb and nuclear excitation amplitudes with the DWBA and the coupled-channel formalism. The existence of this interference minimum could be explained only by assuming a nuclear deformation stronger than these obtained with light ion scattering. However a small shift between the experimental data and theoretical curves suggests that effects of a stronger complex coupling or nuclear reorientation due to the large quadrupole moment of 20 Ne must be included [fr

Absolute determination of zero-energy phase shifts for multiparticle single-channel scattering: Generalized Levinson theorem

International Nuclear Information System (INIS)

Rosenberg, L.; Spruch, L.

1996-01-01

Levinson close-quote s theorem relates the zero-energy phase shift δ for potential scattering in a given partial wave l, by a spherically symmetric potential that falls off sufficiently rapidly, to the number of bound states of that l supported by the potential. An extension of this theorem is presented that applies to single-channel scattering by a compound system initially in its ground state. As suggested by Swan [Proc. R. Soc. London Ser. A 228, 10 (1955)], the extended theorem differs from that derived for potential scattering; even in the absence of composite bound states δ may differ from zero as a consequence of the Pauli principle. The derivation given here is based on the introduction of a continuous auxiliary open-quote open-quote length phase close-quote close-quote η, defined modulo π for l=0 by expressing the scattering length as A=acotη, where a is a characteristic length of the target. Application of the minimum principle for the scattering length determines the branch of the cotangent curve on which η lies and, by relating η to δ, an absolute determination of δ is made. The theorem is applicable, in principle, to single-channel scattering in any partial wave for e ± -atom and nucleon-nucleus systems. In addition to a knowledge of the number of composite bound states, information (which can be rather incomplete) concerning the structure of the target ground-state wave function is required for an explicit, absolute, determination of the phase shift δ. As for Levinson close-quote s original theorem for potential scattering, no additional information concerning the scattering wave function or scattering dynamics is required. copyright 1996 The American Physical Society

Dispersive effects from a comparison of electron and positron scattering from

International Nuclear Information System (INIS)

Paul Gueye; M. Bernheim; J. F. Danel; Jean-Eric Ducret; L. Lakehal-Ayat; J. M. Le Goff; A. Magnon; C. March; J. Morgenstern; Jacques Marroncle; Pascal Vernin; A. Zghiche-Lakehal-Ayat; Vincent Breton; Salvatore Frullani; Franco Garibaldi; F. Ghio; Mauro Iodice; D. B. Isabelle; Zein-Eddine Meziani; E. Offermann; M. Traini

1998-01-01

Dispersive effects have been investigated by comparing elastic scattering of electrons and positrons from 12 C at the Saclay Linear Accelerator. The results demonstrate that dispersive effects at energies of 262 MeV and 450 MeV are less than 2% below the first diffraction minimum [0.95 eff (fm -1 ) eff = 1.84 fm -1 ), the deviation between the positron scattering cross section and the cross section derived from the electron results is -44% ± 30%

The Minimum Core for Numeracy Audit and Test

CERN Document Server

Patmore, Mark

2008-01-01

This book supports trainee teachers in the Lifelong Learning Sector in the assessment of their numeracy knowledge. A self-audit section is included to help trainees understand their level of competence and confidence in numeracy and will help them identify any gaps in their knowledge and skills. This is followed by exercises and activities to support and enhance learning. The book covers all the content of the LLUK standards for the minimum core for numeracy. Coverage and assessment of the minimum core have to be embedded in all Certificate and Diploma courses leading to QTLS and ATLS status.

Scattering of light from small nematic spheres with radial dielectric anisotropy

International Nuclear Information System (INIS)

Karacali, H.; Risser, S.M.; Ferris, K.F.

1997-01-01

We have calculated the scattering cross sections of small anisotropic nematic droplets embedded in a polymer matrix as a function of the dielectric constants of the nematic and the polymer. We have derived the general form for the Helmholtz wave equation for a droplet which has spatially varying radial anisotropy, and have explicitly solved this equation for three distinct models of the dielectric anisotropy, including one model where the anisotropy increases linearly with droplet radius. Numerical calculations of the scattering amplitudes for droplets much smaller than the wavelength of the incident radiation show that droplets with continual variation in the dielectric anisotropy have much larger scattering amplitude than droplets with fixed anisotropy. The scattering from droplets with linearly varying anisotropy exhibits a scattering minimum for much smaller polymer dielectric constants than the other models. These results show that the scattering from small anisotropic droplets is sensitive to details of the internal structure and anisotropy of the droplet. copyright 1997 The American Physical Society

The angle-angular momentum and entropic uncertainty relations for quantum scattering

International Nuclear Information System (INIS)

Ion, D.B.; Ion, M.L.

1999-01-01

Recently the entropic uncertainty relations are obtained in a more general form by using Tsallis-like entropies for the quantum scattering. Hence, using Riesz theorem, the state-independent entropic angle-angular momentum uncertainty relations are proved for the Tsallis-like scattering entropies of spinless particles. The generalized entropic inequalities for the Tsallis-like entropies are presented. The two upper bounds are optimal bounds and can be obtained via Lagrange multipliers by extremizing the Tsallis-like entropies subject to the normalization constraints, respectively. The proof of the lower bound is provided by considering the condition that the angular distribution of probability, P(x) has, everywhere, a finite magnitude. Next, by using the Riesz Theorem a general result was obtained, appearing as inequalities valid for the case of hadron-hadron scattering. An important entropic uncertainty relation for the scattering of spinless particle was thus obtained. For σ el and dσ/dΩ, fixed from experiment, we proved that the optimal scattering entropies are the maximum possible entropies in the scattering process. In as previous paper it was shown that the experimental values of the entropies for the pion--nucleus scatterings are systematically described by the optimal entropies, at all available pion kinetic energies. In this sense the obtained results can also be considered as new experimental signatures for the validity of the principle of minimum distance in space of scattering states. The extension of the optimal state analysis to the generalized non-extensive statistics case, as well as, a test of the entropic inequalities, can be obtained in similar way by using non-extensive optimal entropies. Since this kind of analysis is more involved the numerical examples will be given in a following more extended paper. Finally, we believe that the results obtained here are encouraging for further investigations of the entropic uncertainty relations as well

Mie scattering in heavy-metal fluoride glasses

International Nuclear Information System (INIS)

Edgar, A.

1996-01-01

Heavy-metal fluoride glasses comprise mixtures of heavy-cation fluorides such as those of zirconium, barium, and lanthanum together with some stabilising fluorides such as AlF 3 . For particular relative proportions, the mixtures form a glass rather than a polycrystalline material when quenched from the melt. The particularly useful features of these glasses are the wide spectral region (∼200nm-8000nm) over which they are transparent, the low minimum attenuation at the centre of the spectral window, and the ease with which optically-active rare-earth ions can be incorporated, leading to potential applications in passive and active fibre optics. The minimal attenuation, which is potentially lower than for silica fibre, is generally limited by wavelength-independent scattering by particle and gas bubble inclusions. We have observed a new wavelength-dependent scattering effect in fluoride glass of the well-known composition ZLABN20. In this paper, we report on work in progress on the optical extinction and scattering spectrum of the fluoride glasses, and discuss the spectra in terms of Mie's scattering theory. The chemical nature of the scattering centres in these nominally 'pure' glasses is at present a puzzle, and relative merits of various possible models will be compared

Thomson scattering diagnostic for the microwave tokamak experiment

International Nuclear Information System (INIS)

Foote, J.H.; Barter, J.D.; Sewall, N.R.; Jolly, J.J.; Schlander, L.F.

1990-01-01

The Thomson scattering diagnostic system (TSS) on the microwave tokamak experiment (MTX) at LLNL routinely monitors electron temperature (T e ) and density. Typical measured values at the plasma center under clean conditions are 900±70 eV and 1--2x10 14 (±30%) cm -3 . The TSS apparatus is compact, with all elements mounted on one sturdy, two-level optics table. Because of this, we maintain with minimum effort the alignment of both the ruby-laser input optics and the scattered-light collecting optics. Undesired background signals, e.g., plasma light as well as ruby-laser light scattered off obstacles and walls, are generally small compared with the Thomson-scattered signals we normally detect. In the MTX T e region, the TSS data are definitely fitted better when relativistic effects are included in the equations. Besides determining the temperature of the Maxwellian electron distribution, the system is designed to detect electron heating from GW-level free-electron laser (FEL) pulses by measuring large wavelength shifts of the scattered laser photons. TSS data suggest that we may indeed be able to detect these electrons, which can have energies up to 10 keV, according to computer simulation

Study of water diffusion on single-supported bilayer lipid membranes by quasielastic neutron scattering

DEFF Research Database (Denmark)

Bai, M.; Miskowiec, A.; Hansen, F. Y.

2012-01-01

High-energy-resolution quasielastic neutron scattering has been used to elucidate the diffusion of water molecules in proximity to single bilayer lipid membranes supported on a silicon substrate. By varying sample temperature, level of hydration, and deuteration, we identify three different types...... of diffusive water motion: bulk-like, confined, and bound. The motion of bulk-like and confined water molecules is fast compared to those bound to the lipid head groups (7-10 H2O molecules per lipid), which move on the same nanosecond time scale as H atoms within the lipid molecules. Copyright (C) EPLA, 2012...

Incoherent scatter studies of upper atmosphere dynamics and coding technique

International Nuclear Information System (INIS)

Haeggstroem, Ingemar.

1990-09-01

Observations by the EISCAT incoherent scatter radar are used to study the dynamics of the auroral upper atmosphere. The study describes some effects of the strong plasma convection occurring at these latitudes and a new coding technique for incoherent scatter radars. A technique to determine the thermospheric neutral wind from incoherent scatter measurements is described. Simultaneous Fabry-Perot interferometer measurements of the wind are compared with those derived from the radar data. F-region electron density depletions in the afternoon/evening sector of the auroral zone, identified as the main ionospheric trough, are investigated. In a statistical study, based on wide latitude scanning experiment made at solar minimum, the trough appearance at a given latitude is compared to the geomagnetic index K p , and an empirical model predicting the latitude of the trough is proposed. Detailed studies, using different experiment modes, show that the equatorward edge of the auroral oval is co-located of up to 1 degree poleward of the trough minimum, which in turn is co-located with the peak convective electric field, with its boundary 1 degree - 2 degree equatorward of the trough minimum. It is shown that the F-region ion composition changes from pure 0 + to molecular ion dominated (NO + /O 2 + ) as the trough moves into the region probed by the radar. In a special case, where a geomagnetic sudden impulse caused an expansion of the plasma convection pattern, the equatorward trough progression is studied together with ionosonde measurements. A new coding technique for incoherent scatter radar measurement is introduced and described. The method, called alternating codes, provides significantly more accurate estimates of the plasma parameters than can be obtained by frequency commutated multipulse measurements. Simple explanations of the method are given as well as a precise definition. Two examples of application of the alternating codes are presented, showing the high

Reconstruction of atomic effective potentials from isotropic scattering factors

International Nuclear Information System (INIS)

Romera, E.; Angulo, J.C.; Torres, J.J.

2002-01-01

We present a method for the approximate determination of one-electron effective potentials of many-electron systems from a finite number of values of the isotropic scattering factor. The method is based on the minimum cross-entropy technique. An application to some neutral ground-state atomic systems has been done within a Hartree-Fock framework

Design for minimum energy in interstellar communication

Science.gov (United States)

Messerschmitt, David G.

2015-02-01

Microwave digital communication at interstellar distances is the foundation of extraterrestrial civilization (SETI and METI) communication of information-bearing signals. Large distances demand large transmitted power and/or large antennas, while the propagation is transparent over a wide bandwidth. Recognizing a fundamental tradeoff, reduced energy delivered to the receiver at the expense of wide bandwidth (the opposite of terrestrial objectives) is advantageous. Wide bandwidth also results in simpler design and implementation, allowing circumvention of dispersion and scattering arising in the interstellar medium and motion effects and obviating any related processing. The minimum energy delivered to the receiver per bit of information is determined by cosmic microwave background alone. By mapping a single bit onto a carrier burst, the Morse code invented for the telegraph in 1836 comes closer to this minimum energy than approaches used in modern terrestrial radio. Rather than the terrestrial approach of adding phases and amplitudes increases information capacity while minimizing bandwidth, adding multiple time-frequency locations for carrier bursts increases capacity while minimizing energy per information bit. The resulting location code is simple and yet can approach the minimum energy as bandwidth is expanded. It is consistent with easy discovery, since carrier bursts are energetic and straightforward modifications to post-detection pattern recognition can identify burst patterns. Time and frequency coherence constraints leading to simple signal discovery are addressed, and observations of the interstellar medium by transmitter and receiver constrain the burst parameters and limit the search scope.

List of publications resulting from the Neutron Beam Scattering Programme supported by the Science and Engineering Research Council for 1984

International Nuclear Information System (INIS)

1984-12-01

The paper lists the references of publications resulting from the Neutron Beam Scattering Programme supported by the Science and Engineering Research Council, covering the year 1984, but also including publications from 1983 not given in the previous issue of this listing. (author)

Electron-longitudinal-acoustic-phonon scattering in double-quantum-dot based quantum gates

International Nuclear Information System (INIS)

Zhao Peiji; Woolard, Dwight L.

2008-01-01

We propose a nanostructure design which can significantly suppress longitudinal-acoustic-phonon-electron scattering in double-quantum-dot based quantum gates for quantum computing. The calculated relaxation rates vs. bias voltage exhibit a double-peak feature with a minimum approaching 10 5 s -1 . In this matter, the energy conservation law prohibits scattering contributions from phonons with large momenta; furthermore, increasing the barrier height between the double quantum dots reduces coupling strength between the dots. Hence, the joint action of the energy conservation law and the decoupling greatly reduces the scattering rates. The degrading effects of temperatures can be reduced simply by increasing the height of the barrier between the dots

Principle of minimum distance in space of states as new principle in quantum physics

International Nuclear Information System (INIS)

Ion, D. B.; Ion, M. L. D.

2007-01-01

The mathematician Leonhard Euler (1707-1783) appears to have been a philosophical optimist having written: 'Since the fabric of universe is the most perfect and is the work of the most wise Creator, nothing whatsoever take place in this universe in which some relation of maximum or minimum does not appear. Wherefore, there is absolutely no doubt that every effect in universe can be explained as satisfactory from final causes themselves the aid of the method of Maxima and Minima, as can from the effective causes'. Having in mind this kind of optimism in the papers mentioned in this work we introduced and investigated the possibility to construct a predictive analytic theory of the elementary particle interaction based on the principle of minimum distance in the space of quantum states (PMD-SQS). So, choosing the partial transition amplitudes as the system variational variables and the distance in the space of the quantum states as a measure of the system effectiveness, we obtained the results presented in this paper. These results proved that the principle of minimum distance in space of quantum states (PMD-SQS) can be chosen as variational principle by which we can find the analytic expressions of the partial transition amplitudes. In this paper we present a description of hadron-hadron scattering via principle of minimum distance PMD-SQS when the distance in space of states is minimized with two directional constraints: dσ/dΩ(±1) = fixed. Then by using the available experimental (pion-nucleon and kaon-nucleon) phase shifts we obtained not only consistent experimental tests of the PMD-SQS optimality, but also strong experimental evidences for new principles in hadronic physics such as: Principle of nonextensivity conjugation via the Riesz-Thorin relation (1/2p + 1/2q = 1) and a new Principle of limited uncertainty in nonextensive quantum physics. The strong experimental evidence obtained here for the nonextensive statistical behavior of the [J, �

Optimal numerical methods for determining the orientation averages of single-scattering properties of atmospheric ice crystals

International Nuclear Information System (INIS)

Um, Junshik; McFarquhar, Greg M.

2013-01-01

The optimal orientation averaging scheme (regular lattice grid scheme or quasi Monte Carlo (QMC) method), the minimum number of orientations, and the corresponding computing time required to calculate the average single-scattering properties (i.e., asymmetry parameter (g), single-scattering albedo (ω o ), extinction efficiency (Q ext ), scattering efficiency (Q sca ), absorption efficiency (Q abs ), and scattering phase function at scattering angles of 90° (P 11 (90°)), and 180° (P 11 (180°))) within a predefined accuracy level (i.e., 1.0%) were determined for four different nonspherical atmospheric ice crystal models (Gaussian random sphere, droxtal, budding Bucky ball, and column) with maximum dimension D=10μm using the Amsterdam discrete dipole approximation at λ=0.55, 3.78, and 11.0μm. The QMC required fewer orientations and less computing time than the lattice grid. The calculations of P 11 (90°) and P 11 (180°) required more orientations than the calculations of integrated scattering properties (i.e., g, ω o , Q ext , Q sca , and Q abs ) regardless of the orientation average scheme. The fewest orientations were required for calculating g and ω o . The minimum number of orientations and the corresponding computing time for single-scattering calculations decreased with an increase of wavelength, whereas they increased with the surface-area ratio that defines particle nonsphericity. -- Highlights: •The number of orientations required to calculate the average single-scattering properties of nonspherical ice crystals is investigated. •Single-scattering properties of ice crystals are calculated using ADDA. •Quasi Monte Carlo method is more efficient than lattice grid method for scattering calculations. •Single-scattering properties of ice crystals depend on a newly defined parameter called surface area ratio

A direct sampling method for inverse electromagnetic medium scattering

KAUST Repository

Ito, Kazufumi

2013-09-01

In this paper, we study the inverse electromagnetic medium scattering problem of estimating the support and shape of medium scatterers from scattered electric/magnetic near-field data. We shall develop a novel direct sampling method based on an analysis of electromagnetic scattering and the behavior of the fundamental solution. It is applicable to a few incident fields and needs only to compute inner products of the measured scattered field with the fundamental solutions located at sampling points. Hence, it is strictly direct, computationally very efficient and highly robust to the presence of data noise. Two- and three-dimensional numerical experiments indicate that it can provide reliable support estimates for multiple scatterers in the case of both exact and highly noisy data. © 2013 IOP Publishing Ltd.

Salt-body Inversion with Minimum Gradient Support and Sobolev Space Norm Regularizations

KAUST Repository

Kazei, Vladimir

2017-05-26

Full-waveform inversion (FWI) is a technique which solves the ill-posed seismic inversion problem of fitting our model data to the measured ones from the field. FWI is capable of providing high-resolution estimates of the model, and of handling wave propagation of arbitrary complexity (visco-elastic, anisotropic); yet, it often fails to retrieve high-contrast geological structures, such as salt. One of the reasons for the FWI failure is that the updates at earlier iterations are too smooth to capture the sharp edges of the salt boundary. We compare several regularization approaches, which promote sharpness of the edges. Minimum gradient support (MGS) regularization focuses the inversion on blocky models, even more than the total variation (TV) does. However, both approaches try to invert undesirable high wavenumbers in the model too early for a model of complex structure. Therefore, we apply the Sobolev space norm as a regularizing term in order to maintain a balance between sharp and smooth updates in FWI. We demonstrate the application of these regularizations on a Marmousi model, enriched by a chunk of salt. The model turns out to be too complex in some parts to retrieve its full velocity distribution, yet the salt shape and contrast are retrieved.

A two-stage method for inverse medium scattering

KAUST Repository

Ito, Kazufumi

2013-03-01

We present a novel numerical method to the time-harmonic inverse medium scattering problem of recovering the refractive index from noisy near-field scattered data. The approach consists of two stages, one pruning step of detecting the scatterer support, and one resolution enhancing step with nonsmooth mixed regularization. The first step is strictly direct and of sampling type, and it faithfully detects the scatterer support. The second step is an innovative application of nonsmooth mixed regularization, and it accurately resolves the scatterer size as well as intensities. The nonsmooth model can be efficiently solved by a semi-smooth Newton-type method. Numerical results for two- and three-dimensional examples indicate that the new approach is accurate, computationally efficient, and robust with respect to data noise. © 2012 Elsevier Inc.

Thomson scattering diagnostic for the Microwave Tokamak Experiment

International Nuclear Information System (INIS)

Foote, J.H.; Barter, J.D.; Sewall, N.R.; Jolly, J.J.; Schlander, L.F.

1990-01-01

The Thomson-scattering diagnostic system (TSS) on the Microwave Tokamak Experiment (MTX) at LLNL routinely monitors electron temperature (T e ) and density. Typical measured values at the plasma center under clean conditions are 900 ± 70 eV and 1 to 2 x 10 14 (±30%) cm -3 . The TSS apparatus is compact, with all elements mounted on one sturdy, two-level optics table. Because of this, we maintain with minimum effort the alignment of both the ruby-laser input optics and the scattered-light collecting optics. Undesired background signals, e.g., plasma light as well as ruby-laser light scattered off obstacles and walls, are generally small compared with the Thomson-scattered signals we normally detect. In the MTX T e region, the TSS data are definitely fitted better when relativistic effects are included in the equations. Besides determining the temperature of the Maxwellian electron distribution, the system is designed to detect electron heating from GW-level free-electron laser (FEL) pulses by measuring large wavelength shifts of the scattered laser photons. TSS data suggest that we may indeed by able to detect these electrons, which can have energies up to 10 keV, according to computer simulation. 7 refs., 4 figs

Proposed minimum requirements for the operational characteristics and testing of closed circuit life support system control electronics.

Science.gov (United States)

Kirk, J C

1998-01-01

The popularization and transformation of scuba diving into a broadly practiced sport has served to ignite the interest of technically oriented divers into ever more demanding areas. This, along with the gradual release of military data, equipment, and techniques of closed circuit underwater breathing apparatus, has resulted in a virtual explosion of semiclosed and closed circuit systems for divers. Although many of these systems have been carefully thought out by capable designers, the impulse to rush to market with equipment that has not been fully developed and carefully tested is irresistible to marketers. In addition, the presence of systems developed by well-intentioned and otherwise competent designers who are, nonetheless, inexperienced in the field of life support can result in the sale of failure-prone equipment to divers who lack the knowledge and skills to identify deficiencies before disaster occurs. For this reason, a set of industry standards establishing minimum requirements and testing is needed to guide the designers of this equipment, and to protect the user community from incomplete or inadequate design. Many different technologies go into the development of closed circuit scuba. One key area is the design of electronics to monitor and maintain the critical gas mixtures of the closed circuit loop. Much of the system reliability and inherent danger is resident in the design of the circuitry and the software (if any) that runs it. This article will present a set of proposed minimum requirements, with the goal of establishing a dialog for the creation of guidelines for the classification, rating, design, and testing of embedded electronics for life support systems used in closed circuit applications. These guidelines will serve as the foundation for the later creation of a set of industry specifications.

Directional Scattering of Semiconductor Nanoparticles Embedded in a Liquid Crystal

Directory of Open Access Journals (Sweden)

Braulio García-Cámara

2014-04-01

Full Text Available Light scattering by semiconductor nanoparticles has been shown to be more complex than was believed until now. Both electric and magnetic responses emerge in the visible range. In addition, directional effects on light scattering of these nanoparticles were recently obtained. In particular, zero backward and minimum-forward scattering are observed. These phenomena are very interesting for several applications such as, for instance, optical switches or modulators. The strong dependence of these phenomena on the properties of both the particle and the surrounding medium can be used to tune them. The electrical control on the optical properties of liquid crystals could be used to control the directional effects of embedded semiconductor nanoparticles. In this work, we theoretically analyze the effects on the directional distribution of light scattering by these particles when the refractive index of a surrounded liquid crystal changes from the ordinary to the extraordinary configuration. Several semiconductor materials and liquid crystals are studied in order to optimize the contrast between the two states.

A direct sampling method for inverse electromagnetic medium scattering

KAUST Repository

Ito, Kazufumi; Jin, Bangti; Zou, Jun

2013-01-01

In this paper, we study the inverse electromagnetic medium scattering problem of estimating the support and shape of medium scatterers from scattered electric/magnetic near-field data. We shall develop a novel direct sampling method based

Efficient scattering angle filtering for Full waveform inversion

KAUST Repository

Alkhalifah, Tariq Ali

2015-01-01

Controlling the scattering angles between the state and the adjoint variables for the energy admitted into an inversion gradient or an image can help improve these functions for objectives in full waveform inversion (FWI) or seismic imaging. However, the access of the scattering angle information usually requires an axis extension that could be costly, especially in 3D. For the purpose of a scattering angle filter, I develop techniques that utilize the mapping nature (no domain extension) of the filter for constant-velocity background models to interpolate between such filtered gradients using the actual velocity. The concept has well known roots in the application of phase-shift-plus-interpolation utilized commonly in the downward continuation process. If the difference between the minimum and maximum velocity of the background medium is large, we obtain filtered gradients corresponding to more constant velocity backgrounds and use linear interpolation between such velocities. The accuracy of this approximation for the Marmousi model gradient demonstrates the e ectiveness of the approach.

Efficient scattering angle filtering for Full waveform inversion

KAUST Repository

Alkhalifah, Tariq Ali

2015-08-19

Controlling the scattering angles between the state and the adjoint variables for the energy admitted into an inversion gradient or an image can help improve these functions for objectives in full waveform inversion (FWI) or seismic imaging. However, the access of the scattering angle information usually requires an axis extension that could be costly, especially in 3D. For the purpose of a scattering angle filter, I develop techniques that utilize the mapping nature (no domain extension) of the filter for constant-velocity background models to interpolate between such filtered gradients using the actual velocity. The concept has well known roots in the application of phase-shift-plus-interpolation utilized commonly in the downward continuation process. If the difference between the minimum and maximum velocity of the background medium is large, we obtain filtered gradients corresponding to more constant velocity backgrounds and use linear interpolation between such velocities. The accuracy of this approximation for the Marmousi model gradient demonstrates the e ectiveness of the approach.

Information entropies in antikaon-nucleon scattering and optimal state analysis

International Nuclear Information System (INIS)

Ion, D.B.; Ion, M.L.; Petrascu, C.

1998-01-01

It is known that Jaynes interpreted the entropy as the expected self-information of a class of mutually exclusive and exhaustive events, while the probability is considered to be the rational degree of belief we assign to events based on available experimental evidence. The axiomatic derivation of Jaynes principle of maximum entropy as well as of the Kullback principle of minimum cross-entropy have been reported. Moreover, the optimal states in the Hilbert space of the scattering amplitude, which are analogous to the coherent states from the Hilbert space of the wave functions, were introduced and developed. The possibility that each optimal state possesses a specific minimum entropic uncertainty relation similar to that of the coherent states was recently conjectured. In fact, the (angle and angular momenta) information entropies, as well as the entropic angle-angular momentum uncertainty relations, in the hadron-hadron scattering, are introduced. The experimental information entropies for the pion-nucleon scattering are calculated by using the available phase shift analyses. These results are compared with the information entropies of the optimal states. Then, the optimal state dominance in the pion-nucleon scattering is systematically observed for all P LAB = 0.02 - 10 GeV/c. Also, it is shown that the angle-angular momentum entropic uncertainty relations are satisfied with high accuracy by all the experimental information entropies. In this paper the (angle and angular momentum) information entropies of hadron-hadron scattering are experimentally investigated by using the antikaon-nucleon phase shift analysis. Then, it is shown that the experimental entropies are in agreement with the informational entropies of optimal states. The results obtained in this paper can be explained not only by the presence of an optimal background which accompanied the production of the elementary resonances but also by the presence of the optimal resonances. On the other hand

The application of inelastic neutron scattering to investigate the steam reforming of methane over an alumina-supported nickel catalyst

International Nuclear Information System (INIS)

McFarlane, Andrew R.; Silverwood, Ian P.; Norris, Elizabeth L.; Ormerod, R. Mark; Frost, Christopher D.; Parker, Stewart F.; Lennon, David

2013-01-01

Highlights: • Inelastic neutron scattering has been used to investigate a Ni/alumina catalyst. • The extent of hydrogen retention by the catalyst has been determined. • Filamentous carbon is identified as a by-product. - Abstract: An alumina-supported nickel catalyst, previously used in methane reforming experiments employing CO 2 as the oxidant, is applied here in the steam reforming variant of the process. Micro-reactor experiments are used to discern an operational window compatible with sample cells designed for inelastic neutron scattering (INS) experiments. INS spectra are recorded after 6 h reaction of a 1:1 mixture of CH 4 and H 2 O at 898 K. Weak INS spectra are observed, indicating minimal hydrogen retention by the catalyst in this operational regime. Post-reaction, the catalyst is further characterised by powder X-ray diffraction, transmission electron microscopy and Raman scattering. In a comparable fashion to that seen for the ‘dry’ reforming experiments, the catalyst retains substantial quantities of carbon in the form of filamentous coke. The role for hydrogen incorporation by the catalyst is briefly considered

The application of inelastic neutron scattering to investigate the steam reforming of methane over an alumina-supported nickel catalyst

Energy Technology Data Exchange (ETDEWEB)

McFarlane, Andrew R.; Silverwood, Ian P. [School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Norris, Elizabeth L.; Ormerod, R. Mark [Department of Chemistry, School of Physical and Geographical Sciences, Keele University, Staffs ST5 5BG (United Kingdom); Frost, Christopher D.; Parker, Stewart F. [ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Lennon, David, E-mail: David.Lennon@glasgow.ac.uk [School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2013-12-12

Highlights: • Inelastic neutron scattering has been used to investigate a Ni/alumina catalyst. • The extent of hydrogen retention by the catalyst has been determined. • Filamentous carbon is identified as a by-product. - Abstract: An alumina-supported nickel catalyst, previously used in methane reforming experiments employing CO{sub 2} as the oxidant, is applied here in the steam reforming variant of the process. Micro-reactor experiments are used to discern an operational window compatible with sample cells designed for inelastic neutron scattering (INS) experiments. INS spectra are recorded after 6 h reaction of a 1:1 mixture of CH{sub 4} and H{sub 2}O at 898 K. Weak INS spectra are observed, indicating minimal hydrogen retention by the catalyst in this operational regime. Post-reaction, the catalyst is further characterised by powder X-ray diffraction, transmission electron microscopy and Raman scattering. In a comparable fashion to that seen for the ‘dry’ reforming experiments, the catalyst retains substantial quantities of carbon in the form of filamentous coke. The role for hydrogen incorporation by the catalyst is briefly considered.

Pay equity, minimum wage and equality at work

OpenAIRE

Rubery, Jill

2003-01-01

Reviews the underlying causes of pay discrimination embedded within the organization of the labour market and structures of pay and reward. Discusses the need to focus on pay equity as part of a general strategy of promoting equity and decent work and examines the case for using minimum wage policies in comparison to more targeted equal pay policies to reduce gender pay equity. Identifies potential obstacles to or support for such policies and describes experiences of the use of minimum wages...

The Minimum Core for Language and Literacy Audit and Test

CERN Document Server

Machin, Lynn

2007-01-01

This book supports trainee teachers in the Lifelong Learning Sector in the assessment of their literacy knowledge. A self-audit section is included to help trainees understand their level of competence and confidence in literacy and will help them identify any gaps in their knowledge and skills. This is followed by exercises and activities to support and enhance learning. The book covers all the content of the LLUK standards for the minimum core for literacy. Coverage and assessment of the minimum core have to be embedded in all Certificate and Diploma courses leading to QTLS and ATLS status.

Scattering equations, supergravity integrands, and pure spinors

Energy Technology Data Exchange (ETDEWEB)

Adamo, Tim; Casali, Eduardo [Department of Applied Mathematics & Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

2015-05-25

The tree-level S-matrix of type II supergravity can be computed in scattering equation form by correlators in a worldsheet theory analogous to a chiral, infinite tension limit of the pure spinor formalism. By defining a non-minimal version of this theory, we give a prescription for computing correlators on higher genus worldsheets which manifest space-time supersymmetry. These correlators are conjectured to provide the loop integrands of supergravity scattering amplitudes, supported on the scattering equations. We give non-trivial evidence in support of this conjecture at genus one and two with four external states. Throughout, we find a close correspondence with the pure spinor formalism of superstring theory, particularly regarding regulators and zero-mode counting.

Scattering equations, supergravity integrands, and pure spinors

International Nuclear Information System (INIS)

Adamo, Tim; Casali, Eduardo

2015-01-01

The tree-level S-matrix of type II supergravity can be computed in scattering equation form by correlators in a worldsheet theory analogous to a chiral, infinite tension limit of the pure spinor formalism. By defining a non-minimal version of this theory, we give a prescription for computing correlators on higher genus worldsheets which manifest space-time supersymmetry. These correlators are conjectured to provide the loop integrands of supergravity scattering amplitudes, supported on the scattering equations. We give non-trivial evidence in support of this conjecture at genus one and two with four external states. Throughout, we find a close correspondence with the pure spinor formalism of superstring theory, particularly regarding regulators and zero-mode counting.

The equivalent square concept for the head scatter factor based on scatter from flattening filter

Energy Technology Data Exchange (ETDEWEB)

Kim, Siyong; Palta, Jatinder R.; Zhu, Timothy C. [Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, Florida (United States)

1998-06-01

The equivalent field relationship between square and circular fields for the head scatter factor was evaluated at the source plane. The method was based on integrating the head scatter parameter for projected shaped fields in the source plane and finding a field that produced the same ratio of head scatter to primary dose on the central axis. A value of {sigma}/R{approx_equal}0.9 was obtained, where {sigma} was one-half of the side length of the equivalent square and R was the radius of the circular field. The assumptions were that the equivalent field relationship for head scatter depends primarily on the characteristics of scatter from the flattening filter, and that the differential scatter-to-primary ratio of scatter from the flattening filter decreases linearly with the radius, within the physical radius of the flattening filter. Lam and co-workers showed empirically that the area-to-perimeter ratio formula, when applied to an equivalent square formula at the flattening filter plane, gave an accurate prediction of the head scatter factor. We have analytically investigated the validity of the area-to-perimeter ratio formula. Our results support the fact that the area-to-perimeter ratio formula can also be used as the equivalent field formula for head scatter at the source plane. The equivalent field relationships for wedge and tertiary collimator scatter were also evaluated. (author)

The equivalent square concept for the head scatter factor based on scatter from flattening filter

International Nuclear Information System (INIS)

Kim, Siyong; Palta, Jatinder R.; Zhu, Timothy C.

1998-01-01

The equivalent field relationship between square and circular fields for the head scatter factor was evaluated at the source plane. The method was based on integrating the head scatter parameter for projected shaped fields in the source plane and finding a field that produced the same ratio of head scatter to primary dose on the central axis. A value of σ/R≅0.9 was obtained, where σ was one-half of the side length of the equivalent square and R was the radius of the circular field. The assumptions were that the equivalent field relationship for head scatter depends primarily on the characteristics of scatter from the flattening filter, and that the differential scatter-to-primary ratio of scatter from the flattening filter decreases linearly with the radius, within the physical radius of the flattening filter. Lam and co-workers showed empirically that the area-to-perimeter ratio formula, when applied to an equivalent square formula at the flattening filter plane, gave an accurate prediction of the head scatter factor. We have analytically investigated the validity of the area-to-perimeter ratio formula. Our results support the fact that the area-to-perimeter ratio formula can also be used as the equivalent field formula for head scatter at the source plane. The equivalent field relationships for wedge and tertiary collimator scatter were also evaluated. (author)

Reforming the minimum wage: Toward a psychological perspective.

Science.gov (United States)

Smith, Laura

2015-09-01

The field of psychology has periodically used its professional and scholarly platform to encourage national policy reform that promotes the public interest. In this article, the movement to raise the federal minimum wage is presented as an issue meriting attention from the psychological profession. Psychological support for minimum wage reform derives from health disparities research that supports the causal linkages between poverty and diminished physical and emotional well-being. Furthermore, psychological scholarship relevant to the social exclusion of low-income people not only suggests additional benefits of financially inclusive policymaking, it also indicates some of the attitudinal barriers that could potentially hinder it. Although the national living wage debate obviously extends beyond psychological parameters, psychologists are well-positioned to evaluate and contribute to it. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Robust inverse scattering full waveform seismic tomography for imaging complex structure

International Nuclear Information System (INIS)

Nurhandoko, Bagus Endar B.; Sukmana, Indriani; Wibowo, Satryo; Deny, Agus; Kurniadi, Rizal; Widowati, Sri; Mubarok, Syahrul; Susilowati; Kaswandhi

2012-01-01

Seismic tomography becomes important tool recently for imaging complex subsurface. It is well known that imaging complex rich fault zone is difficult. In this paper, The application of time domain inverse scattering wave tomography to image the complex fault zone would be shown on this paper, especially an efficient time domain inverse scattering tomography and their run in cluster parallel computer which has been developed. This algorithm is purely based on scattering theory through solving Lippmann Schwienger integral by using Born's approximation. In this paper, it is shown the robustness of this algorithm especially in avoiding the inversion trapped in local minimum to reach global minimum. A large data are solved by windowing and blocking technique of memory as well as computation. Parameter of windowing computation is based on shot gather's aperture. This windowing technique reduces memory as well as computation significantly. This parallel algorithm is done by means cluster system of 120 processors from 20 nodes of AMD Phenom II. Benchmarking of this algorithm is done by means Marmoussi model which can be representative of complex rich fault area. It is shown that the proposed method can image clearly the rich fault and complex zone in Marmoussi model even though the initial model is quite far from the true model. Therefore, this method can be as one of solution to image the very complex mode.

Robust inverse scattering full waveform seismic tomography for imaging complex structure

Energy Technology Data Exchange (ETDEWEB)

Nurhandoko, Bagus Endar B.; Sukmana, Indriani; Wibowo, Satryo; Deny, Agus; Kurniadi, Rizal; Widowati, Sri; Mubarok, Syahrul; Susilowati; Kaswandhi [Wave Inversion and Subsurface Fluid Imaging Research (WISFIR) Lab., Complex System Research Division, Physics Department, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung. and Rock Fluid Imaging Lab., Rock Physics and Cluster C (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung (Indonesia); Physics Department of Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung, Indonesia and Institut Teknologi Telkom, Bandung (Indonesia); Rock Fluid Imaging Lab., Rock Physics and Cluster Computing Center, Bandung (Indonesia)

2012-06-20

Seismic tomography becomes important tool recently for imaging complex subsurface. It is well known that imaging complex rich fault zone is difficult. In this paper, The application of time domain inverse scattering wave tomography to image the complex fault zone would be shown on this paper, especially an efficient time domain inverse scattering tomography and their run in cluster parallel computer which has been developed. This algorithm is purely based on scattering theory through solving Lippmann Schwienger integral by using Born's approximation. In this paper, it is shown the robustness of this algorithm especially in avoiding the inversion trapped in local minimum to reach global minimum. A large data are solved by windowing and blocking technique of memory as well as computation. Parameter of windowing computation is based on shot gather's aperture. This windowing technique reduces memory as well as computation significantly. This parallel algorithm is done by means cluster system of 120 processors from 20 nodes of AMD Phenom II. Benchmarking of this algorithm is done by means Marmoussi model which can be representative of complex rich fault area. It is shown that the proposed method can image clearly the rich fault and complex zone in Marmoussi model even though the initial model is quite far from the true model. Therefore, this method can be as one of solution to image the very complex mode.

Faster Fully-Dynamic minimum spanning forest

DEFF Research Database (Denmark)

Holm, Jacob; Rotenberg, Eva; Wulff-Nilsen, Christian

2015-01-01

We give a new data structure for the fully-dynamic minimum spanning forest problem in simple graphs. Edge updates are supported in O(log4 n/log logn) expected amortized time per operation, improving the O(log4 n) amortized bound of Holm et al. (STOC’98, JACM’01).We also provide a deterministic data...

Excitation function of elastic $pp$ scattering from a unitarily extended Bialas-Bzdak model

CERN Document Server

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 ...

Evaluation of aggregate stability of Haplic Stagnosols using dynamic light scattering, phase analysis light scattering and color coordinates

Czech Academy of Sciences Publication Activity Database

Artemyeva, Z.; Žigová, Anna; Kirillova, N.; Šťastný, Martin; Holubík, O.; Podrázský, V.

2017-01-01

Roč. 63, č. 13 (2017), s. 1838-1851 ISSN 0365-0340 Institutional support: RVO:67985831 Keywords : land use * aggregate stability * organo-clay complexes * dynamic light scattering * phase analysis light scattering * color coordinates Subject RIV: DF - Soil Science OBOR OECD: Soil science Impact factor: 2.137, year: 2016

Automatic scatter detection in fluorescence landscapes by means of spherical principal component analysis

DEFF Research Database (Denmark)

Kotwa, Ewelina Katarzyna; Jørgensen, Bo Munk; Brockhoff, Per B.

2013-01-01

In this paper, we introduce a new method, based on spherical principal component analysis (S‐PCA), for the identification of Rayleigh and Raman scatters in fluorescence excitation–emission data. These scatters should be found and eliminated as a prestep before fitting parallel factor analysis...... models to the data, in order to avoid model degeneracies. The work is inspired and based on a previous research, where scatter removal was automatic (based on a robust version of PCA called ROBPCA) and required no visual data inspection but appeared to be computationally intensive. To overcome...... this drawback, we implement the fast S‐PCA in the scatter identification routine. Moreover, an additional pattern interpolation step that complements the method, based on robust regression, will be applied. In this way, substantial time savings are gained, and the user's engagement is restricted to a minimum...

Protons scattering on Li isotopes at intermediate energies

International Nuclear Information System (INIS)

Zhusupov, M.A.; Imambekov, O.; Sanfirova, A.V.; Ibraeva, E.T.

2003-01-01

The protons scattering differential cross section on the 6,7,8 Li nuclei are calculated within the framework the Glauber-Sitenko multiple scattering theory at intermediate energies (from 100 to 1000 MeV). In the calculations the multi-cluster wave functions (αt for 7 Li, αnp for 6 Li, and αtn for 8 Li) considering within potential cluster model have been used. Differential cross sections for 6 Li, 7 Li, 8 Li and 9 Li nuclei are similar: absolute cross sections are almost the same, diffraction minimum for large A shifting to the field of the least scattering angles that reflecting increase of the material radius. For the 11 Li the differential cross section absolute value is smaller about in two time than for the rest isotopes. At present it is reliably established, that the 11 Li nucleus has an exotic structure - the nine-nucleon core ( 9 Li) around which the two-neutron halo is rotating. The principal characteristics of the Li nuclei are presented in tabular form

Electron–phonon interaction and scattering in phosphorene

Science.gov (United States)

Fan, Xiaolin; Zhao, Guojun; Wang, Shudong

2018-04-01

The electron–phonon scattering of phosphorene is investigated via performing first-principles calculations. Our results reveal that the scattering rates are negligible at the valence band maximum (VBM) and conduction band minimum, but they are much larger away from the band edges. The scattering rates increase with the rising temperature. The relaxation times run up to ~850 fs around the VBM at 1 K, and they will decrease with the increasing temperature. In addition, we find that the mean free paths (MFPs) are anisotropic. The MFPs along the armchair direction are two times larger than that along the zigzag direction near the band edges. According to our results, we predict that the extraction of hot holes is best achieved along the armchair direction in phosphorene with a 65 nm range at 1 K. The best extraction range of hot electrons is less than 30 nm along the armchair direction at 1 K. On the other hand, the extraction range of hot holes and hot electrons will decrease to 15 nm along both directions in phosphorene at 300 K.

Minimum area thresholds for rattlesnakes and colubrid snakes on islands in the Gulf of California, Mexico.

Science.gov (United States)

Meik, Jesse M; Makowsky, Robert

2018-01-01

We expand a framework for estimating minimum area thresholds to elaborate biogeographic patterns between two groups of snakes (rattlesnakes and colubrid snakes) on islands in the western Gulf of California, Mexico. The minimum area thresholds for supporting single species versus coexistence of two or more species relate to hypotheses of the relative importance of energetic efficiency and competitive interactions within groups, respectively. We used ordinal logistic regression probability functions to estimate minimum area thresholds after evaluating the influence of island area, isolation, and age on rattlesnake and colubrid occupancy patterns across 83 islands. Minimum area thresholds for islands supporting one species were nearly identical for rattlesnakes and colubrids (~1.7 km 2 ), suggesting that selective tradeoffs for distinctive life history traits between rattlesnakes and colubrids did not result in any clear advantage of one life history strategy over the other on islands. However, the minimum area threshold for supporting two or more species of rattlesnakes (37.1 km 2 ) was over five times greater than it was for supporting two or more species of colubrids (6.7 km 2 ). The great differences between rattlesnakes and colubrids in minimum area required to support more than one species imply that for islands in the Gulf of California relative extinction risks are higher for coexistence of multiple species of rattlesnakes and that competition within and between species of rattlesnakes is likely much more intense than it is within and between species of colubrids.

Application of support vector regression for optimization of vibration flow field of high-density polyethylene melts characterized by small angle light scattering

Science.gov (United States)

Xian, Guangming

2018-03-01

In this paper, the vibration flow field parameters of polymer melts in a visual slit die are optimized by using intelligent algorithm. Experimental small angle light scattering (SALS) patterns are shown to characterize the processing process. In order to capture the scattered light, a polarizer and an analyzer are placed before and after the polymer melts. The results reported in this study are obtained using high-density polyethylene (HDPE) with rotation speed at 28 rpm. In addition, support vector regression (SVR) analytical method is introduced for optimization the parameters of vibration flow field. This work establishes the general applicability of SVR for predicting the optimal parameters of vibration flow field.

Nursing Minimum Data Set Based on EHR Archetypes Approach.

Science.gov (United States)

Spigolon, Dandara N; Moro, Cláudia M C

2012-01-01

The establishment of a Nursing Minimum Data Set (NMDS) can facilitate the use of health information systems. The adoption of these sets and represent them based on archetypes are a way of developing and support health systems. The objective of this paper is to describe the definition of a minimum data set for nursing in endometriosis represent with archetypes. The study was divided into two steps: Defining the Nursing Minimum Data Set to endometriosis, and Development archetypes related to the NMDS. The nursing data set to endometriosis was represented in the form of archetype, using the whole perception of the evaluation item, organs and senses. This form of representation is an important tool for semantic interoperability and knowledge representation for health information systems.

Quasiparticle Scattering in the Rashba Semiconductor BiTeBr: The Roles of Spin and Defect Lattice Site.

Science.gov (United States)

Butler, Christopher John; Yang, Po-Ya; Sankar, Raman; Lien, Yen-Neng; Lu, Chun-I; Chang, Luo-Yueh; Chen, Chia-Hao; Wei, Ching-Ming; Chou, Fang-Cheng; Lin, Minn-Tsong

2016-09-28

Observations of quasiparticle interference have been used in recent years to examine exotic carrier behavior at the surfaces of emergent materials, connecting carrier dispersion and scattering dynamics to real-space features with atomic resolution. We observe quasiparticle interference in the strongly Rashba split 2DEG-like surface band found at the tellurium termination of BiTeBr and examine two mechanisms governing quasiparticle scattering: We confirm the suppression of spin-flip scattering by comparing measured quasiparticle interference with a spin-dependent elastic scattering model applied to the calculated spectral function. We also use atomically resolved STM maps to identify point defect lattice sites and spectro-microscopy imaging to discern their varying scattering strengths, which we understand in terms of the calculated orbital characteristics of the surface band. Defects on the Bi sublattice cause the strongest scattering of the predominantly Bi 6p derived surface band, with other defects causing nearly no scattering near the conduction band minimum.

An Evaluation of Recent Evidence on the Employment Effects of Minimum and Subminimum Wages

OpenAIRE

David Card; Lawrence F. Katz; Alan B. Krueger

1993-01-01

We re-examine recent cross-state evidence on the employment effect of the minimum wage. A re-evaluation of the data used in Neumark and Wascher's (1992) study of the minimum wage provides no support for their conclusion that the minimum wage has an adverse effect on teenage employment. Neumark and Wascher's findings are shown to be due to an inadvertent mistake in the definition of their school enrollment variable. In addition, Neumark and Wascher's coverage-weighted relative minimum wage ind...

MO-D-211-01: Medical Physics Practice Guidelines - The Minimum Level of Medical Physics Support in Clinical Practice Settings.

Science.gov (United States)

Chan, M; Fontenot, J; Halvorsen, P

2012-06-01

The American Association of Physicists in Medicine (AAPM) has long advocated a consistent level of medical physics practice, and has published many guidelines and position statements toward that goal, such as Science Council Task Group reports related to calibration and quality assurance, Education Council and Professional Council Task Group reports related to education, training, and peer review, and Board-approved Position Statements related to the Scope of Practice, physicist qualifications, and other aspects of medical physicspractice. Despite these concerted and enduring efforts, the profession does not have a clear and concise statement of the acceptable practice guidelines for routine clinical medical physics. As accreditation of clinical practices becomes more common, Medical Physics Practice Guidelines (MPPGs) will be crucial to ensuring a consistent benchmark for accreditation programs. The AAPM will lead the development of MPPGs in collaboration with other professional societies. The MPPGs will be freely available to the general public. Accrediting organizations, regulatory agencies and legislators will be encouraged to reference these MPPGs when defining their respective requirements. MPPGs are intended to provide the medical community with a clear description of the minimum level of medical physics support that the AAPM would consider to be prudent in all clinical practice settings. Support includes but is not limited to staffing, equipment, machine access, and training. These MPPGs are not designed to replace extensive Task Group reports or review articles, but rather to describe the recommended minimum level of medical physics support for specific clinical services. This course will describe the purpose and scope of MPPGs, the procedure for the development of a MPPG, as well as the progress of Therapy MPPG TG #1 on "Evaluation and quality assurance of x-ray based image guided radiotherapy systems" and Diagnostic MPPG TG #2 on "CT Protocol management

Neutron scattering science in Australia

International Nuclear Information System (INIS)

Knott, Robert

1999-01-01

Neutron scattering science in Australia is making an impact on a number of fields in the scientific and industrial research communities. The unique properties of the neutron are being used to investigate problems in chemistry, materials science, physics, engineering and biology. The reactor HIFAR at the Australian Nuclear Science and Technology Organisation research laboratories is the only neutron source in Australia suitable for neutron scattering science. A suite of instruments provides a wide range of opportunities for the neutron scattering community that extends throughout universities, government and industrial research laboratories. Plans are in progress to replace the present research reactor with a modern multi-purpose research reactor to offer the most advanced neutron scattering facilities. The experimental and analysis equipment associated with a modern research reactor will permit the establishment of a national centre for world class neutron science research focussed on the structure and functioning of materials, industrial irradiations and analyses in support of Australian manufacturing, minerals, petrochemical, pharmaceuticals and information science industries. (author)

Neutron scattering science in Australia

Energy Technology Data Exchange (ETDEWEB)

Knott, Robert [Australian Nuclear Science and Technology Organisation, Menai, NSW (Australia)

1999-10-01

Neutron scattering science in Australia is making an impact on a number of fields in the scientific and industrial research communities. The unique properties of the neutron are being used to investigate problems in chemistry, materials science, physics, engineering and biology. The reactor HIFAR at the Australian Nuclear Science and Technology Organisation research laboratories is the only neutron source in Australia suitable for neutron scattering science. A suite of instruments provides a wide range of opportunities for the neutron scattering community that extends throughout universities, government and industrial research laboratories. Plans are in progress to replace the present research reactor with a modern multi-purpose research reactor to offer the most advanced neutron scattering facilities. The experimental and analysis equipment associated with a modern research reactor will permit the establishment of a national centre for world class neutron science research focussed on the structure and functioning of materials, industrial irradiations and analyses in support of Australian manufacturing, minerals, petrochemical, pharmaceuticals and information science industries. (author)

(p,4He) elastic scattering at 350, 650, 1050, and 1150 MeV

International Nuclear Information System (INIS)

Aslanides, E.; Brochard, F.; Gorodetzky, P.; Hibou, F.; Lambert, E.

1977-01-01

Angular distributions of p- 4 He elastic scattering differential cross sections have been measured at 350, 650, 1050 and 1150 MeV, in regions of four-momentum transfer squared t=0.02-0.71 (GeV/c) 2 . These new measurements confirm the absence of a pronounced first diffraction minimum. New theoretical analyses are also presented. (Auth.)

The Kinetics of Crystallization of Colloids and Proteins: A Light Scattering Study

Science.gov (United States)

McClymer, Jim

2002-01-01

ALV light detection optics, which is fed into an APD detector module and linked to a computer. The scattering angle (between 12 and 160 degrees), scattering angle step size (0.1 degree minimum) and acquisition time (minimum 3 s) is set by the user.

Stellar Spectral Classification with Minimum Within-Class and ...

Indian Academy of Sciences (India)

Support Vector Machine (SVM) is one of the important stellar spectral classification methods, and it is widely used in practice. But its classification efficiencies cannot be greatly improved because it does not take the class distribution into consideration. In view of this, a modified SVM-named Minimum within-class and ...

Optical scattering measurement and analysis

CERN Document Server

Stover, John C

2012-01-01

Newly included are scatter models for pits and particles as well as the use of wafer scanners to locate and size isolated surface features. New sections cover the multimillion-dollar wafer scanner business, establishing that microroughness is the noise, not the signal, in these systems. Scatter measurements, now routinely used to determine whether small-surface features are pits or particles and inspiring new technology that provides information on particle material, are also discussed. These new capabilities are now supported by a series of international standards, and a new chapter reviews t

Solving crystal structures with the symmetry minimum function

International Nuclear Information System (INIS)

Estermann, M.A.

1995-01-01

Unravelling the Patterson function (the auto-correlation function of the crystal structure) (A.L. Patterson, Phys. Rev. 46 (1934) 372) can be the only way of solving crystal structures from neutron and incomplete diffraction data (e.g. powder data) when direct methods for phase determination fail. The negative scattering lengths of certain isotopes and the systematic loss of information caused by incomplete diffraction data invalidate the underlying statistical assumptions made in direct methods. In contrast, the Patterson function depends solely on the quality of the available diffraction data. Simpson et al. (P.G. Simpson et al., Acta Crystallogr. 18 (1965) 169) showed that solving a crystal structure with a particular superposition of origin-shifted Patterson functions, the symmetry minimum function, is advantageous over using the Patterson function alone, for single-crystal X-ray data.This paper describes the extension of the Patterson superposition approach to neutron data and powder data by (a) actively using the negative regions in the Patterson map caused by negative scattering lengths and (b) using maximum entropy Patterson maps (W.I.F. David, Nature 346 (1990) 731). Furthermore, prior chemical knowledge such as bond lengths and angles from known fragments have been included. Two successful structure solutions of a known and a previously unknown structure (M. Hofmann, J. Solid State Chem., in press) illustrate the potential of this new development. ((orig.))

Minimum energy consumption process synthesis for energy saving

Energy Technology Data Exchange (ETDEWEB)

Xiao-Ping, Jia [Institute for Petroleum and Chemical Industry, Qingdao University of Science and Technology, Qingdao 266042, Shandong (China); Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Fang, Wang; Shu-Guang, Xiang; Xin-Sun, Tan; Fang-Yu, Han [Institute for Petroleum and Chemical Industry, Qingdao University of Science and Technology, Qingdao 266042, Shandong (China)

2008-05-15

The paper presents a synthesis strategy for the chemical processes with energy saving. The concept of minimum energy consumption process (MECP) is proposed. Three characteristics of MECP are introduced, including thermodynamic minimum energy demand, energy consumption efficiency and integration degree. These characteristics are evaluated according to quantitative thermodynamic analysis and qualitative knowledge rules. The procedure of synthesis strategy is proposed to support the generation of MECP alternatives, which combine flowsheet integration and heat integration. The cases studies will focus on how integration degrees of a process affect the energy-saving results. The separation sequences of the hydrodealkylation of toluene (HDA) process and ethanol distillation process as case studies are used to illustrate. (author)

Development of ε-insensitive smooth support vector regression for predicting minimum miscibility pressure in CO2 flooding

Directory of Open Access Journals (Sweden)

Shahram Mollaiy-Berneti

2018-02-01

Full Text Available Successful design of a carbon dioxide (CO2 flooding in enhanced oil recovery projects mostly depends on accurate determination of CO2-crude oil minimum miscibility pressure (MMP. Due to the high expensive and time-consuming of experimental determination of MMP, developing a fast and robust method to predict MMP is necessary. In this study, a new method based on ε-insensitive smooth support vector regression (ε-SSVR is introduced to predict MMP for both pure and impure CO2 gas injection cases. The proposed ε-SSVR is developed using dataset of reservoir temperature, crude oil composition and composition of injected CO2. To serve better understanding of the proposed, feed-forward neural network and radial basis function network applied to denoted dataset. The results show that the suggested ε-SSVR has acceptable reliability and robustness in comparison with two other models. Thus, the proposed method can be considered as an alternative way to monitor the MMP in miscible flooding process.

Interband coupling and transport interband scattering in s_± superconductors

Energy Technology Data Exchange (ETDEWEB)

Kogan, Vladimir [Ames Lab., Ames, IA (United States); Prozorov, Ruslan [Ames Lab., Ames, IA (United States); Iowa State Univ., Ames, IA (United States)

2016-04-04

A two-band model with repulsive interband coupling and interband transport (potential) scattering is considered to elucidate their effects on material properties. In agreement with previous work, we find that the bands order parameters Δ_1,2 differ and the large is at the band with a smaller normal density of states (DOS), N_n2 < N_n1. However, the bands energy gaps, as determined by the energy dependence of the DOS, are equal due to scattering. For each temperature, the gaps turn zero at a certain critical interband scattering rate, i.e. for strong enough scattering the model material becomes gappless. In the gapless state, the DOS at the band 2 is close to the normal state value, whereas at the band 1 it has a V-shape with non-zero minimum. When the normal bands DOS' are mismatched, N_n1 6= N_n2, the critical temperature T_c is suppressed even in the absence of interband scattering, T_c(N_n1) has a dome-like shape. With increasing interband scattering, the London penetration depth at low temperatures evolves from being exponentially at to the powerlaw and even to near linear behavior in the gapless state, the latter being easily misinterpreted as caused by order parameter nodes.

Thermal-neutron multiple scattering: critical double scattering

International Nuclear Information System (INIS)

Holm, W.A.

1976-01-01

A quantum mechanical formulation for multiple scattering of thermal-neutrons from macroscopic targets is presented and applied to single and double scattering. Critical nuclear scattering from liquids and critical magnetic scattering from ferromagnets are treated in detail in the quasielastic approximation for target systems slightly above their critical points. Numerical estimates are made of the double scattering contribution to the critical magnetic cross section using relevant parameters from actual experiments performed on various ferromagnets. The effect is to alter the usual Lorentzian line shape dependence on neutron wave vector transfer. Comparison with corresponding deviations in line shape resulting from the use of Fisher's modified form of the Ornstein-Zernike spin correlations within the framework of single scattering theory leads to values for the critical exponent eta of the modified correlations which reproduce the effect of double scattering. In addition, it is shown that by restricting the range of applicability of the multiple scattering theory from the outset to critical scattering, Glauber's high energy approximation can be used to provide a much simpler and more powerful description of multiple scattering effects. When sufficiently close to the critical point, it provides a closed form expression for the differential cross section which includes all orders of scattering and has the same form as the single scattering cross section with a modified exponent for the wave vector transfer

Setting a minimum age for juvenile justice jurisdiction in California.

Science.gov (United States)

S Barnert, Elizabeth; S Abrams, Laura; Maxson, Cheryl; Gase, Lauren; Soung, Patricia; Carroll, Paul; Bath, Eraka

2017-03-13

Purpose Despite the existence of minimum age laws for juvenile justice jurisdiction in 18 US states, California has no explicit law that protects children (i.e. youth less than 12 years old) from being processed in the juvenile justice system. In the absence of a minimum age law, California lags behind other states and international practice and standards. The paper aims to discuss these issues. Design/methodology/approach In this policy brief, academics across the University of California campuses examine current evidence, theory, and policy related to the minimum age of juvenile justice jurisdiction. Findings Existing evidence suggests that children lack the cognitive maturity to comprehend or benefit from formal juvenile justice processing, and diverting children from the system altogether is likely to be more beneficial for the child and for public safety. Research limitations/implications Based on current evidence and theory, the authors argue that minimum age legislation that protects children from contact with the juvenile justice system and treats them as children in need of services and support, rather than as delinquents or criminals, is an important policy goal for California and for other national and international jurisdictions lacking a minimum age law. Originality/value California has no law specifying a minimum age for juvenile justice jurisdiction, meaning that young children of any age can be processed in the juvenile justice system. This policy brief provides a rationale for a minimum age law in California and other states and jurisdictions without one.

Scattering and extinction by spherical particles immersed in an absorbing host medium

Science.gov (United States)

Mishchenko, Michael I.; Dlugach, Janna M.

2018-05-01

Many applications of electromagnetic scattering involve particles immersed in an absorbing rather than lossless medium, thereby making the conventional scattering theory potentially inapplicable. To analyze this issue quantitatively, we employ the FORTRAN program developed recently on the basis of the first-principles electromagnetic theory to study far-field scattering by spherical particles embedded in an absorbing infinite host medium. We further examine the phenomenon of negative extinction identified recently for monodisperse spheres and uncover additional evidence in favor of its interference origin. We identify the main effects of increasing the width of the size distribution on the ensemble-averaged extinction efficiency factor and show that negative extinction can be eradicated by averaging over a very narrow size distribution. We also analyze, for the first time, the effects of absorption inside the host medium and ensemble averaging on the phase function and other elements of the Stokes scattering matrix. It is shown in particular that increasing absorption significantly suppresses the interference structure and can result in a dramatic expansion of the areas of positive polarization. Furthermore, the phase functions computed for larger effective size parameters can develop a very deep minimum at side-scattering angles bracketed by a strong diffraction peak in the forward direction and a pronounced backscattering maximum.

Do Minimum Wages Fight Poverty?

OpenAIRE

David Neumark; William Wascher

1997-01-01

The primary goal of a national minimum wage floor is to raise the incomes of poor or near-poor families with members in the work force. However, estimates of employment effects of minimum wages tell us little about whether minimum wages are can achieve this goal; even if the disemployment effects of minimum wages are modest, minimum wage increases could result in net income losses for poor families. We present evidence on the effects of minimum wages on family incomes from matched March CPS s...

Surface enhanced Raman scattering of gold nanoparticles supported on copper foil with graphene as a nanometer gap

International Nuclear Information System (INIS)

Xiang, Quan; Zhu, Xupeng; Chen, Yiqin; Duan, Huigao

2016-01-01

Gaps with single-nanometer dimensions (<10 nm) between metallic nanostructures enable giant local field enhancements for surface enhanced Raman scattering (SERS). Monolayer graphene is an ideal candidate to obtain a sub-nanometer gap between plasmonic nanostructures. In this work, we demonstrate a simple method to achieve a sub-nanometer gap by dewetting a gold film supported on monolayer graphene grown on copper foil. The Cu foil can serve as a low-loss plasmonically active metallic film that supports the imaginary charge oscillations, while the graphene can not only create a stable sub-nanometer gap for massive plasmonic field enhancements but also serve as a chemical enhancer. We obtained higher SERS enhancements in this graphene-gapped configuration compared to those in Au nanoparticles on Cu film or on graphene–SiO 2 –Si. Also, the Raman signals measured maintained their fine features and intensities over a long time period, indicating the stability of this Au–graphene–Cu hybrid configuration as an SERS substrate. (paper)

The self-association of acebutolol: Conductometry and light scattering

Science.gov (United States)

Ruso, Juan M.; López-Fontán, José L.; Prieto, Gerardo; Sarmiento, Félix

2003-04-01

The association characteristics of an amphiphilic beta-blocker drug, acebutolol hydrochloride, in aqueous solution containing high concentrations of electrolyte and at different temperatures have been examined by static and dynamic light scattering and electrical conductivity. Time averaged light scattering measurements on aqueous solutions of acebutolol at 298.15 K in the presence of added electrolyte (0.4-1.0 mol kg-1 NaCl) have shown discontinuities which reflect the appearance of aggregates. The critical micelle concentration, aggregation numbers, effective micelle charges, and degree of micellar ionization were calculated. Dynamic light scattering has shown an increase in micellar size with increase in concentration of added electrolyte. Data have been interpreted using the DLVO theory to quantify the interaction between the drug aggregates and the colloidal stability. Critical micelle concentrations in water have been calculated from conductivity measurements over the temperature range 288.15-313.15 K. The variation in critical concentration with temperature passes through a minimum close to 294 K. Thermodynamic parameters of aggregate formation (ΔGm0,ΔHm0,ΔSm0) were obtained from a variation of the mass action model applicable to systems of low aggregation number.

Support for cold neutron utilization

International Nuclear Information System (INIS)

Lee, Kye Hong; Han, Young Soo; Choi, Sungmin; Choi, Yong; Kwon, Hoon; Lee, Kwang Hee

2012-06-01

- Support for experiments by users of cold neutron scattering instrument - Short-term training of current and potential users of cold neutron scattering instrument for their effective use of the instrument - International collaboration for advanced utilization of cold neutron scattering instruments - Selection and training of qualified instrument scientists for vigorous research endeavors and outstanding achievements in experiments with cold neutron - Research on nano/bio materials using cold neutron scattering instruments - Bulk nano structure measurement using small angle neutron scattering and development of analysis technique

Characterization of enzymatically induced aggregation of casein micelles in natural concentration by in situ static light scattering and ultra low shear viscosimetry

DEFF Research Database (Denmark)

Lehner, D.; Worning, Peder; G, Fritz

1999-01-01

of multiple scattering whenthe transmission is above 0.85. Due to the very complex and porous structure of the casein aggregates theRayleigh-Debye-Gans scattering theory has been used in the data analysis. Measurements with a newinstrument using ultra low shear showed good agreement with theory. Copyright......The aggregation of casein micelles in undiluted skim milk after the addition of chymosin was studied bystatic light scattering and ultra low shear viscometry. The static light scattering measurements were madewith two different sample thicknesses, 72 and 16 mum. The scattering data were analyzed...... by indirect Fouriertransformation and by the polydispersity inversion technique which led to pair distance distributionfunctions and size distribution function, respectively. The minimum scattering angle was 1 degrees, whichallows for the determination of particle sizes up to a maximum diameter of 12 mum...

Multiple-scattering in radar systems: A review

International Nuclear Information System (INIS)

Battaglia, Alessandro; Tanelli, Simone; Kobayashi, Satoru; Zrnic, Dusan; Hogan, Robin J.; Simmer, Clemens

2010-01-01

Although extensively studied within the lidar community, the multiple scattering phenomenon has always been considered a rare curiosity by radar meteorologists. Up to few years ago its appearance has only been associated with two- or three-body-scattering features (e.g. hail flares and mirror images) involving highly reflective surfaces. Recent atmospheric research aimed at better understanding of the water cycle and the role played by clouds and precipitation in affecting the Earth's climate has driven the deployment of high frequency radars in space. Examples are the TRMM 13.5 GHz, the CloudSat 94 GHz, the upcoming EarthCARE 94 GHz, and the GPM dual 13-35 GHz radars. These systems are able to detect the vertical distribution of hydrometeors and thus provide crucial feedbacks for radiation and climate studies. The shift towards higher frequencies increases the sensitivity to hydrometeors, improves the spatial resolution and reduces the size and weight of the radar systems. On the other hand, higher frequency radars are affected by stronger extinction, especially in the presence of large precipitating particles (e.g. raindrops or hail particles), which may eventually drive the signal below the minimum detection threshold. In such circumstances the interpretation of the radar equation via the single scattering approximation may be problematic. Errors will be large when the radiation emitted from the radar after interacting more than once with the medium still contributes substantially to the received power. This is the case if the transport mean-free-path becomes comparable with the instrument footprint (determined by the antenna beam-width and the platform altitude). This situation resembles to what has already been experienced in lidar observations, but with a predominance of wide- versus small-angle scattering events. At millimeter wavelengths, hydrometeors diffuse radiation rather isotropically compared to the visible or near infrared region where scattering is

Optimized cylindrical invisibility cloak with minimum layers of non-magnetic isotropic materials

International Nuclear Information System (INIS)

Yu Zhenzhong; Feng Yijun; Xu Xiaofei; Zhao Junming; Jiang Tian

2011-01-01

We present optimized design of cylindrical invisibility cloak with minimum layers of non-magnetic isotropic materials. Through an optimization procedure based on genetic algorithm, simpler cloak structure and more realizable material parameters can be achieved with better cloak performance than that of an ideal non-magnetic cloak with a reduced set of parameters. We demonstrate that a cloak shell with only five layers of two normal materials can result in an average 20 dB reduction in the scattering width for all directions when covering the inner conducting cylinder with the cloak. The optimized design can substantially simplify the realization of the invisibility cloak, especially in the optical range.

Setting a minimum age for juvenile justice jurisdiction in California

Science.gov (United States)

Barnert, Elizabeth S.; Abrams, Laura S.; Maxson, Cheryl; Gase, Lauren; Soung, Patricia; Carroll, Paul; Bath, Eraka

2018-01-01

Purpose Despite the existence of minimum age laws for juvenile justice jurisdiction in 18 US states, California has no explicit law that protects children (i.e. youth less than 12 years old) from being processed in the juvenile justice system. In the absence of a minimum age law, California lags behind other states and international practice and standards. The paper aims to discuss these issues. Design/methodology/approach In this policy brief, academics across the University of California campuses examine current evidence, theory, and policy related to the minimum age of juvenile justice jurisdiction. Findings Existing evidence suggests that children lack the cognitive maturity to comprehend or benefit from formal juvenile justice processing, and diverting children from the system altogether is likely to be more beneficial for the child and for public safety. Research limitations/implications Based on current evidence and theory, the authors argue that minimum age legislation that protects children from contact with the juvenile justice system and treats them as children in need of services and support, rather than as delinquents or criminals, is an important policy goal for California and for other national and international jurisdictions lacking a minimum age law. Originality/value California has no law specifying a minimum age for juvenile justice jurisdiction, meaning that young children of any age can be processed in the juvenile justice system. This policy brief provides a rationale for a minimum age law in California and other states and jurisdictions without one. Paper type Conceptual paper PMID:28299968

Means on scattered compacta

Czech Academy of Sciences Publication Activity Database

Banakh, T.; Bonnet, R.; Kubiś, Wieslaw

2014-01-01

Roč. 2, č. 1 (2014), s. 5-10 ISSN 2299-3231 R&D Projects: GA ČR(CZ) GAP201/12/0290 Institutional support: RVO:67985840 Keywords : scattered compact space * mean operation Subject RIV: BA - General Mathematics http://www.degruyter.com/view/j/taa.2014.2.issue-1/taa-2014-0002/taa-2014-0002.xml

Preference of small molecules for local minimum conformations when binding to proteins.

Directory of Open Access Journals (Sweden)

Qi Wang

2007-09-01

Full Text Available It is well known that small molecules (ligands do not necessarily adopt their lowest potential energy conformations when binding to proteins. Analyses of protein-bound ligand crystal structures have reportedly shown that many of them do not even adopt the conformations at local minima of their potential energy surfaces (local minimum conformations. The results of these analyses raise a concern regarding the validity of virtual screening methods that use ligands in local minimum conformations. Here we report a normal-mode-analysis (NMA study of 100 crystal structures of protein-bound ligands. Our data show that the energy minimization of a ligand alone does not automatically stop at a local minimum conformation if the minimum of the potential energy surface is shallow, thus leading to the folding of the ligand. Furthermore, our data show that all 100 ligand conformations in their protein-bound ligand crystal structures are nearly identical to their local minimum conformations obtained from NMA-monitored energy minimization, suggesting that ligands prefer to adopt local minimum conformations when binding to proteins. These results both support virtual screening methods that use ligands in local minimum conformations and caution about possible adverse effect of excessive energy minimization when generating a database of ligand conformations for virtual screening.

The impact of radiation belts region on top side ionosphere condition during last solar minimum.

Science.gov (United States)

Rothkaehl, Hanna; Przepiórka, Dororta; Matyjasiak, Barbara

2014-05-01

The wave particle interactions in radiation belts region are one of the key parameters in understanding the global physical processes which govern the near Earth environment. The populations of outer radiation belts electrons increasing in response to changes in the solar wind and the interplanetary magnetic field, and decreasing as a result of scattering into the loss cone and subsequent absorption by the atmosphere. The most important question in relation to understanding the physical processes in radiation belts region relates to estimate the ratio between acceleration and loss processes. This can be also very useful for construct adequate models adopted in Space Weather program. Moreover the wave particle interaction in inner radiation zone and in outer radiation zone have significant influence on the space plasma property at ionospheric altitude. The aim of this presentation is to show the manifestation of radiation belts region at the top side ionosphere during the last long solar minimum. The presentation of longitude and seasonal changes of plasma parameters affected by process occurred in radiation belts region has been performed on the base of the DEMETER and COSMIC 3 satellite registration. This research is partly supported by grant O N517 418440

The minimum mass of detectable planets in protoplanetary discs and the derivation of planetary masses from high-resolution observations.

Science.gov (United States)

Rosotti, Giovanni P; Juhasz, Attila; Booth, Richard A; Clarke, Cathie J

2016-07-01

We investigate the minimum planet mass that produces observable signatures in infrared scattered light and submillimetre (submm) continuum images and demonstrate how these images can be used to measure planet masses to within a factor of about 2. To this end, we perform multi-fluid gas and dust simulations of discs containing low-mass planets, generating simulated observations at 1.65, 10 and 850 μm. We show that the minimum planet mass that produces a detectable signature is ∼15 M ⊕ : this value is strongly dependent on disc temperature and changes slightly with wavelength (favouring the submm). We also confirm previous results that there is a minimum planet mass of ∼20 M ⊕ that produces a pressure maximum in the disc: only planets above this threshold mass generate a dust trap that can eventually create a hole in the submm dust. Below this mass, planets produce annular enhancements in dust outwards of the planet and a reduction in the vicinity of the planet. These features are in steady state and can be understood in terms of variations in the dust radial velocity, imposed by the perturbed gas pressure radial profile, analogous to a traffic jam. We also show how planet masses can be derived from structure in scattered light and submm images. We emphasize that simulations with dust need to be run over thousands of planetary orbits so as to allow the gas profile to achieve a steady state and caution against the estimation of planet masses using gas-only simulations.

Low scatter edge blackening compounds for refractive optical elements

International Nuclear Information System (INIS)

Lewis, I.T.; Telkamp, A.R.; Ledebuhr, A.G.

1989-01-01

This paper reports on low scatter edge blackening compounds for refractive optical elements. Perkin-Elmer's Applied Optics Operation recently delivered several prototype wide-field-of-view (WFOV), F/2.8, 250 mm efl, near diffraction limited, concentric lenses toLawrence Livermore National Laboratory (LLNL). In these lenses, special attention was paid to reducing stray light to allow viewing of very dim objects. Because of the very large FOV, the use of a long baffle to eliminate direct illumination of lens edges was not practical. With the existing relatively short baffle design, one-bounce stray light paths off the element edges are possible. The scattering off the inside edges thus had to be kept to an absolute minimum. While common means for blackening the edges of optical elements are easy to apply and quite cost effective for normal lens assemblies, their blackening effect is limited by the Fresnel reflection due to the index of refraction mismatch at the glass boundary. At high angles of incidence, total internal reflection (TIR) might occur ruining the effect of the blackening process. An index-match absorbing medium applied to the edges of such elements is the most effective approach for reducing the amount of undesired light reflection or scattered off these edges. The presence of such a medium provides an extended path outside the glass boundary in which an absorptive non-scattering dye can be used to eliminate light that might otherwise have propagated to the focal plane

Rising above the Minimum Wage.

Science.gov (United States)

Even, William; Macpherson, David

An in-depth analysis was made of how quickly most people move up the wage scale from minimum wage, what factors influence their progress, and how minimum wage increases affect wage growth above the minimum. Very few workers remain at the minimum wage over the long run, according to this study of data drawn from the 1977-78 May Current Population…

The circuit of polychromator for Experimental Advanced Superconducting Tokamak edge Thomson scattering diagnostic

International Nuclear Information System (INIS)

Zang, Qing; Zhao, Junyu; Chen, Hui; Li, Fengjuan; Hsieh, C. L.

2013-01-01

The detector circuit is the core component of filter polychromator which is used for scattering light analysis in Thomson scattering diagnostic, and is responsible for the precision and stability of a system. High signal-to-noise and stability are primary requirements for the diagnostic. Recently, an upgraded detector circuit for weak light detecting in Experimental Advanced Superconducting Tokamak (EAST) edge Thomson scattering system has been designed, which can be used for the measurement of large electron temperature (T e ) gradient and low electron density (n e ). In this new circuit, a thermoelectric-cooled avalanche photodiode with the aid circuit is involved for increasing stability and enhancing signal-to-noise ratio (SNR), especially the circuit will never be influenced by ambient temperature. These features are expected to improve the accuracy of EAST Thomson diagnostic dramatically. Related mechanical construction of the circuit is redesigned as well for heat-sinking and installation. All parameters are optimized, and SNR is dramatically improved. The number of minimum detectable photons is only 10

Light scattering measurements supporting helical structures for chromatin in solution.

Science.gov (United States)

Campbell, A M; Cotter, R I; Pardon, J F

1978-05-01

Laser light scattering measurements have been made on a series of polynucleosomes containing from 50 to 150 nucleosomes. Radii of gyration have been determined as a function of polynucleosome length for different ionic strength solutions. The results suggest that at low ionic strength the chromatin adopts a loosely helical structure rather than a random coil. The helix becomes more regular on increasing the ionic strength, the dimension resembling those proposed by Finch and Klug for their solenoid model.

Computer simulation program for medium-energy ion scattering and Rutherford backscattering spectrometry

Science.gov (United States)

Nishimura, Tomoaki

2016-03-01

A computer simulation program for ion scattering and its graphical user interface (MEISwin) has been developed. Using this program, researchers have analyzed medium-energy ion scattering and Rutherford backscattering spectrometry at Ritsumeikan University since 1998, and at Rutgers University since 2007. The main features of the program are as follows: (1) stopping power can be chosen from five datasets spanning several decades (from 1977 to 2011), (2) straggling can be chosen from two datasets, (3) spectral shape can be selected as Gaussian or exponentially modified Gaussian, (4) scattering cross sections can be selected as Coulomb or screened, (5) simulations adopt the resonant elastic scattering cross section of 16O(4He, 4He)16O, (6) pileup simulation for RBS spectra is supported, (7) natural and specific isotope abundances are supported, and (8) the charge fraction can be chosen from three patterns (fixed, energy-dependent, and ion fraction with charge-exchange parameters for medium-energy ion scattering). This study demonstrates and discusses the simulations and their results.

Minimum Lens Size Supporting the Leaky-Wave Nature of Slit Dipole Antenna at Terahertz Frequency

Directory of Open Access Journals (Sweden)

Niamat Hussain

2016-01-01

Full Text Available We designed a slit dipole antenna backed by an extended hemispherical silicon lens and investigated the minimum lens size in which the slit dipole antenna works as a leaky-wave antenna. The slit dipole antenna consists of a planar feeding structure, which is a center-fed and open-ended slot line. A slit dipole antenna backed by an extended hemispherical silicon lens is investigated over a frequency range from 0.2 to 0.4 THz with the center frequency at 0.3 THz. The numerical results show that the antenna gain responses exhibited an increased level of sensitivity to the lens size and increased linearly with increasing lens radius. The lens with the radius of 1.2λo is found to be the best possible minimum lens size for a slit dipole antenna on an extended hemispherical silicon lens.

Neutron scattering instruments for the Spallation Neutron Source (SNS)

International Nuclear Information System (INIS)

Crawford, R.K.; Fornek, T.; Herwig, K.W.

1998-01-01

The Spallation Neutron Source (SNS) is a 1 MW pulsed spallation source for neutron scattering planned for construction at Oak Ridge National Laboratory. This facility is being designed as a 5-laboratory collaboration project. This paper addresses the proposed facility layout, the process for selection and construction of neutron scattering instruments at the SNS, the initial planning done on the basis of a reference set of ten instruments, and the plans for research and development (R and D) to support construction of the first ten instruments and to establish the infrastructure to support later development and construction of additional instruments

Proposal for a new Thomson scattering technique for large fusion devices

International Nuclear Information System (INIS)

Salzmann, H.; Hirsch, K.

1982-11-01

The application of 180 0 scattering using ultrashort laser pulses is proposed. Spatial resolution along the laser beam is achieved by high-speed detection allowing time-of-flight measurements. This LIDAR technique uses a minimum number of window ports, reduces drastically the number of optical components in the vicinity of the discharge vessel and makes remote control unnecessary. As an example the performance of such a system is discussed on the basis of available laser and detection technology for the JET geometry. (orig.)

Compton scattering collision module for OSIRIS

Science.gov (United States)

Del Gaudio, Fabrizio; Grismayer, Thomas; Fonseca, Ricardo; Silva, Luís

2017-10-01

Compton scattering plays a fundamental role in a variety of different astrophysical environments, such as at the gaps of pulsars and the stagnation surface of black holes. In these scenarios, Compton scattering is coupled with self-consistent mechanisms such as pair cascades. We present the implementation of a novel module, embedded in the self-consistent framework of the PIC code OSIRIS 4.0, capable of simulating Compton scattering from first principles and that is fully integrated with the self-consistent plasma dynamics. The algorithm accounts for the stochastic nature of Compton scattering reproducing without approximations the exchange of energy between photons and unbound charged species. We present benchmarks of the code against the analytical results of Blumenthal et al. and the numerical solution of the linear Kompaneets equation and good agreement is found between the simulations and the theoretical models. This work is supported by the European Research Council Grant (ERC- 2015-AdG 695088) and the Fundao para a Céncia e Tecnologia (Bolsa de Investigao PD/BD/114323/2016).

A compact multichannel spectrometer for Thomson scattering

International Nuclear Information System (INIS)

Schoenbeck, N. L.; Schlossberg, D. J.; Dowd, A. S.; Fonck, R. J.; Winz, G. R.

2012-01-01

The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of T e e > 100 eV by a 2072 l/mm VPH grating. The spectrometer uses a fast-gated (∼2 ns) ICCD camera for detection. A Gen III image intensifier provides ∼45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction.

A compact multichannel spectrometer for Thomson scattering.

Science.gov (United States)

Schoenbeck, N L; Schlossberg, D J; Dowd, A S; Fonck, R J; Winz, G R

2012-10-01

The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of T(e) VPH grating and measurements T(e) > 100 eV by a 2072 l∕mm VPH grating. The spectrometer uses a fast-gated (~2 ns) ICCD camera for detection. A Gen III image intensifier provides ~45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction.

Employment effects of minimum wages

OpenAIRE

Neumark, David

2014-01-01

The potential benefits of higher minimum wages come from the higher wages for affected workers, some of whom are in low-income families. The potential downside is that a higher minimum wage may discourage employers from using the low-wage, low-skill workers that minimum wages are intended to help. Research findings are not unanimous, but evidence from many countries suggests that minimum wages reduce the jobs available to low-skill workers.

Impact of HIPAA's minimum necessary standard on genomic data sharing.

Science.gov (United States)

Evans, Barbara J; Jarvik, Gail P

2018-04-01

This article provides a brief introduction to the Health Insurance Portability and Accountability Act of 1996 (HIPAA) Privacy Rule's minimum necessary standard, which applies to sharing of genomic data, particularly clinical data, following 2013 Privacy Rule revisions. This research used the Thomson Reuters Westlaw database and law library resources in its legal analysis of the HIPAA privacy tiers and the impact of the minimum necessary standard on genomic data sharing. We considered relevant example cases of genomic data-sharing needs. In a climate of stepped-up HIPAA enforcement, this standard is of concern to laboratories that generate, use, and share genomic information. How data-sharing activities are characterized-whether for research, public health, or clinical interpretation and medical practice support-affects how the minimum necessary standard applies and its overall impact on data access and use. There is no clear regulatory guidance on how to apply HIPAA's minimum necessary standard when considering the sharing of information in the data-rich environment of genomic testing. Laboratories that perform genomic testing should engage with policy makers to foster sound, well-informed policies and appropriate characterization of data-sharing activities to minimize adverse impacts on day-to-day workflows.

Application of the equivalent radiator method for radiative corrections to the spectra of elastic electron scattering by nuclei

Directory of Open Access Journals (Sweden)

I. S. Timchenko

2015-07-01

Full Text Available For calculating the radiative tails in the spectra of inelastic electron scattering by nuclei, the approximation, namely, the equivalent radiator method (ERM, is used. However, the applicability of this method for evaluating the radiative tail from the elastic scattering peak has been little investigated, and therefore, it has become the subject of the present study for the case of light nuclei. As a result, spectral regions were found, where a significant discrepancy between the ERM calculation and the exact-formula calculation was observed. A link was established between this phenomenon and the diffraction minimum of the squared form-factor of the nuclear ground state. Varieties of calculations were carried out for different kinematics of electron scattering by nuclei. The analysis of the calculation results has shown the conditions, at which the equivalent radiator method can be applied for adequately evaluating the radiative tail of the elastic scattering peak.

Direct nn-scattering at the YAGUAR reactor

Energy Technology Data Exchange (ETDEWEB)

Crawford, B.E. [Gettysburg College, Department of Physics, Gettysburg, PA 17325 (United States)]. E-mail: bcrawfor@gettysburg.edu; Furman, W.I. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Howell, C.R. [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Lychagin, E.V. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Levakov, B.G. [Russian Federal Nuclear Center-All Russian Research Institute of Technical Physics, P.O. Box 245, Snezhinsk 456770 (Russian Federation); Litvin, V.I. [Russian Federal Nuclear Center-All Russian Research Institute of Technical Physics, P.O. Box 245, Snezhinsk 456770 (Russian Federation); Lyzhin, A.E. [Russian Federal Nuclear Center-All Russian Research Institute of Technical Physics, P.O. Box 245, Snezhinsk 456770 (Russian Federation); Magda, E.P. [Russian Federal Nuclear Center-All Russian Research Institute of Technical Physics, P.O. Box 245, Snezhinsk 456770 (Russian Federation); Mitchell, G.E. [North Carolina State University, Raleigh, NC 27695-8202 (United States); Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States); Muzichka, A.Yu. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Nekhaev, G.V. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Sharapov, E.I. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Shvetsov, V.N. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Stephenson, S.L. [Gettysburg College, Department of Physics, Gettysburg, PA 17325 (United States); Strelkov, A.V. [Joint Institute for Nuclear Research, Dubna 141980 (Russian Federation); Tornow, W. [Duke University and Triangle Universities Nuclear Laboratory, Durham, NC 27708-0308 (United States)

2005-12-15

The Direct Investigation of a {sub nn} Association (DIANNA) is finalizing the design of a direct measurement of the nn-scattering length to be performed at the YAGUAR reactor in Snezhinsk, Russia. Extensive modeling of the neutron field, nn-scattering kinematics, and sources of detector background have verified the plan for a 3% measurement of a {sub nn}. Measurements of the neutron flux support the neutron field modeling. Initial test measurements of the neutron field inside the underground channel have confirmed calculations of the thermal neutron background.

The challenge of observation on livings things by employing an ultra small-angle neutron scattering method

International Nuclear Information System (INIS)

Koizumi, Satoshi; Motokawa, Ryuhei; Iwase, Hiroki; Miyamoto, Nobuyoshi; Tanaka, Kazuhiro; Masui, Tomomi; Iida, You; Yue, Zhao; Chiba, Kaori; Kumada, Takayuki; Yamaguchi, Daisuke; Hashimoto, Takeji

2007-01-01

To address the question as to how small-angle scattering is effectively applied to the cell, i.e., a hierarchically ordered system comprising multi-components of macro and small molecules, the size of which ranges from 100 μm to several μm, we reconstructed SANS-J (pinhole small-angle neutron scattering spectrometer at research reactor JRR3, Tokai) to focusing and polarized neutron small-angle spectrometer (SANS-J-II), by employing focusing neutron lenses and high resolution photomultiplier. Consequently, an accessible minimum wave number q min was improved from 3x10 -3 A -1 to medium ultra-small angle scattering of 3x10 -4 A -1 . The focusing USANS method, thus developed, is crucial to fill the gap in wave number q between those covered by a double crystal method and by a conventional pin-hole method. (author)

Minimum Wages and Poverty

OpenAIRE

Fields, Gary S.; Kanbur, Ravi

2005-01-01

Textbook analysis tells us that in a competitive labor market, the introduction of a minimum wage above the competitive equilibrium wage will cause unemployment. This paper makes two contributions to the basic theory of the minimum wage. First, we analyze the effects of a higher minimum wage in terms of poverty rather than in terms of unemployment. Second, we extend the standard textbook model to allow for incomesharing between the employed and the unemployed. We find that there are situation...

75 FR 6151 - Minimum Capital

Science.gov (United States)

2010-02-08

... capital and reserve requirements to be issued by order or regulation with respect to a product or activity... minimum capital requirements. Section 1362(a) establishes a minimum capital level for the Enterprises... entities required under this section.\\6\\ \\3\\ The Bank Act's current minimum capital requirements apply to...

A Pareto-Improving Minimum Wage

OpenAIRE

Eliav Danziger; Leif Danziger

2014-01-01

This paper shows that a graduated minimum wage, in contrast to a constant minimum wage, can provide a strict Pareto improvement over what can be achieved with an optimal income tax. The reason is that a graduated minimum wage requires high-productivity workers to work more to earn the same income as low-productivity workers, which makes it more difficult for the former to mimic the latter. In effect, a graduated minimum wage allows the low-productivity workers to benefit from second-degree pr...

Proposal for the design of a small-angle neutron scattering facility at a pulsed neutron source

International Nuclear Information System (INIS)

Kley, W.

1980-01-01

The intensity-resolution-background considerations of an optimized small angle neutron scattering facility are reviewed for the special case of a pulsed neutron source. In the present proposal we conclude that for 'true elastic scattering experiments' filters can be used instead of expensive neutron guide tubes since low background conditions can be achieved by a combined action of filters as well as a proper time gating of the twodimensional detector. The impinging neutron beam is monochromatized by phasing a disk chopper to the neutron source pulses and in the scattered beam a second disk chopper is used to eliminate the inelastically scattered neutrons. Therefore, no time of fligh analysis is necessary for the scattered neutron intensity and true-elastic conditions are obtained by simply gating the two-dimensional detector. Considering a 4 m thick shield for the pulsed neutron source and choosing for optimum conditions a detector area element of (2.5 cm) 2 and a sample area of (1.25 cm) 2 , than for a minimum sample-detector-distance of 1.5 m, a maximum neutron source diameter of 6.67 cm is required in order to maintain always the optimum intensity- and resolution requirements

Control of light scattering by nanoparticles with optically-induced magnetic responses

International Nuclear Information System (INIS)

Liu Wei; Miroshnichenko, Andrey E.; Kivshar, Yuri S.

2014-01-01

Conventional approaches to control and shape the scattering patterns of light generated by different nanostructures are mostly based on engineering of their electric response due to the fact that most metallic nanostructures support only electric resonances in the optical frequency range. Recently, fuelled by the fast development in the fields of metamaterials and plasmonics, artificial optically-induced magnetic responses have been demonstrated for various nanostructures. This kind of response can be employed to provide an extra degree of freedom for the efficient control and shaping of the scattering patterns of nanoparticles and nanoantennas. Here we review the recent progress in this research direction of nanoparticle scattering shaping and control through the interference of both electric and optically-induced magnetic responses. We discuss the magnetic resonances supported by various structures in different spectral regimes, and then summarize the original results on the scattering shaping involving both electric and magnetic responses, based on the interference of both spectrally separated (with different resonant wavelengths) and overlapped dipoles (with the same resonant wavelength), and also other higher-order modes. Finally, we discuss the scattering control utilizing Fano resonances associated with the magnetic responses. (topical review - plasmonics and metamaterials)

Speckle-learning-based object recognition through scattering media.

Science.gov (United States)

Ando, Takamasa; Horisaki, Ryoichi; Tanida, Jun

2015-12-28

We experimentally demonstrated object recognition through scattering media based on direct machine learning of a number of speckle intensity images. In the experiments, speckle intensity images of amplitude or phase objects on a spatial light modulator between scattering plates were captured by a camera. We used the support vector machine for binary classification of the captured speckle intensity images of face and non-face data. The experimental results showed that speckles are sufficient for machine learning.

Modelling grain-scattered ultrasound in austenitic stainless-steel welds: A hybrid model

International Nuclear Information System (INIS)

Nowers, O.; Duxbury, D. J.; Velichko, A.; Drinkwater, B. W.

2015-01-01

The ultrasonic inspection of austenitic stainless steel welds can be challenging due to their coarse grain structure, charaterised by preferentially oriented, elongated grains. The anisotropy of the weld is manifested as both a ‘steering’ of the beam and the back-scatter of energy due to the macroscopic granular structure of the weld. However, the influence of weld properties, such as mean grain size and orientation distribution, on the magnitude of scattered ultrasound is not well understood. A hybrid model has been developed to allow the study of grain-scatter effects in austenitic welds. An efficient 2D Finite Element (FE) method is used to calculate the complete scattering response from a single elliptical austenitic grain of arbitrary length and width as a function of the specific inspection frequency. A grain allocation model of the weld is presented to approximate the characteristic structures observed in austenitic welds and the complete scattering behaviour of each grain calculated. This model is incorporated into a semi-analytical framework for a single-element inspection of a typical weld in immersion. Experimental validation evidence is demonstrated indicating excellent qualitative agreement of SNR as a function of frequency and a minimum SNR difference of 2 dB at a centre frequency of 2.25 MHz. Additionally, an example Monte-Carlo study is presented detailing the variation of SNR as a function of the anisotropy distribution of the weld, and the application of confidence analysis to inform inspection development

Computer simulation program for medium-energy ion scattering and Rutherford backscattering spectrometry

Energy Technology Data Exchange (ETDEWEB)

Nishimura, Tomoaki, E-mail: t-nishi@hosei.ac.jp

2016-03-15

A computer simulation program for ion scattering and its graphical user interface (MEISwin) has been developed. Using this program, researchers have analyzed medium-energy ion scattering and Rutherford backscattering spectrometry at Ritsumeikan University since 1998, and at Rutgers University since 2007. The main features of the program are as follows: (1) stopping power can be chosen from five datasets spanning several decades (from 1977 to 2011), (2) straggling can be chosen from two datasets, (3) spectral shape can be selected as Gaussian or exponentially modified Gaussian, (4) scattering cross sections can be selected as Coulomb or screened, (5) simulations adopt the resonant elastic scattering cross section of {sup 16}O({sup 4}He, {sup 4}He){sup 16}O, (6) pileup simulation for RBS spectra is supported, (7) natural and specific isotope abundances are supported, and (8) the charge fraction can be chosen from three patterns (fixed, energy-dependent, and ion fraction with charge-exchange parameters for medium-energy ion scattering). This study demonstrates and discusses the simulations and their results.

Non-equilibrium current via geometric scatterers

Czech Academy of Sciences Publication Activity Database

Exner, Pavel; Neidhardt, H.; Tater, Miloš; Zagrebnov, V. A.

2014-01-01

Roč. 47, č. 39 (2014), s. 395301 ISSN 1751-8113 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : non-equilibrioum steady states * geometric scatterer * Landauer-Buttiker formula Subject RIV: BE - Theoretical Physics Impact factor: 1.583, year: 2014

Minimum critical mass systems

International Nuclear Information System (INIS)

Dam, H. van; Leege, P.F.A. de

1987-01-01

An analysis is presented of thermal systems with minimum critical mass, based on the use of materials with optimum neutron moderating and reflecting properties. The optimum fissile material distributions in the systems are obtained by calculations with standard computer codes, extended with a routine for flat fuel importance search. It is shown that in the minimum critical mass configuration a considerable part of the fuel is positioned in the reflector region. For 239 Pu a minimum critical mass of 87 g is found, which is the lowest value reported hitherto. (author)

Transmittance and scattering during wound healing after refractive surgery

Science.gov (United States)

Mar, Santiago; Martinez-Garcia, C.; Blanco, J. T.; Torres, R. M.; Gonzalez, V. R.; Najera, S.; Rodriguez, G.; Merayo, J. M.

2004-10-01

Photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) are frequent techniques performed to correct ametropia. Both methods have been compared in their way of healing but there is not comparison about transmittance and light scattering during this process. Scattering in corneal wound healing is due to three parameters: cellular size and density, and the size of scar. Increase in the scattering angular width implies a decrease the contrast sensitivity. During wound healing keratocytes activation is induced and these cells become into fibroblasts and myofibroblasts. Hens were operated using PRK and LASIK techniques. Animals used in this experiment were euthanized, and immediately their corneas were removed and placed carefully into a cornea camera support. All optical measurements have been done with a scatterometer constructed in our laboratory. Scattering measurements are correlated with the transmittance -- the smaller transmittance is the bigger scattering is. The aim of this work is to provide experimental data of the corneal transparency and scattering, in order to supply data that they allow generate a more complete model of the corneal transparency.

Combination scattering of dissociating gas applied to measurements of temperature and concentration of components

International Nuclear Information System (INIS)

Pashkov, V.A.; Kurganova, F.I.; Grishchuk, M.Kh.

1987-01-01

The method to calculate the combination scattering power of the components of the dissociating N 2 O 4 ↔ 2NO 2 → 2NO+O 2 gas subjected to the laser radiation effect is given. The combination scattering power has been calculated for temperatures 400-600 K, pressures 1-3 MPa, with the neodymium laser (λ=1.06 μm) as a source and the possibility of measuring the local temperatures and concentration of the given gas components with the help of the combination scattering has been analysed. It follows from the calculated data that combination scattering power of N 2 O 4 ↔ 2NO 2 ↔ 2NO+O 2 gas in excitation with the neodymium laser as a source is sufficient for detection. Gas temperature is likely to be measured with the minimum error relative to stokes and anti-stokes bands of the combination scattering, produced by nitrogen tetroxide. From calculated data it also follows that measurement of NO 2 concentration in the range 400-600 K is possible. At the same time combination scattering power, produced by NO and O 2 components is sufficient for measurement merely with the concentration of the components of the order of 10 18 molecules/cm 3 guaranteed in static conditions only at N 2 O 4 ↔ 2NO 2 ↔ 2NO+O 2 gas temperature 500 K and higher

Neutron-deuteron scattering calculations with W-matrix representation of the two-body input

International Nuclear Information System (INIS)

Bartnik, E.A.; Haberzettl, H.; Januschke, T.; Kerwath, U.; Sandhas, W.

1987-05-01

Employing the W-matrix representation of the partial-wave T matrix introduced by Bartnik, Haberzettl, and Sandhas, we show for the example of the Malfliet-Tjon potentials I and III that the single-term separable part of the W-matrix representation, when used as input in three-nucleon neutron-deuteron scattering calculations, is fully capable of reproducing the exact results obtained by Kloet and Tjon. This approximate two-body input not only satisfies the two-body off-shell unitarity relation but, moreover, it also contains a parameter which may be used in optimizing the three-body data. We present numerical evidence that there exists a variational (minimum) principle for the determination of the three-body binding energy which allows one to choose this parameter also in the absence of an exact reference calculation. Our results for neutron-deuteron scattering show that it is precisely this choice of the parameter which provides optimal scattering data. We conclude that the W-matrix approach, despite its simplicity, is a remarkably efficient tool for high-quality three-nucleon calculations. (orig.)

Nanometer-range atomic order directly recovered from resonant diffuse scattering

Czech Academy of Sciences Publication Activity Database

Kopecký, Miloš; Kub, Jiří; Fábry, Jan; Hlinka, Jiří

2016-01-01

Roč. 93, č. 5 (2016), 1-8, č. článku 054202. ISSN 1098-0121 R&D Projects: GA ČR GA15-04121S Institutional support: RVO:68378271 Keywords : diffuse scattering * resonant scattering * atomic structure * perovskites * relaxors * PbMg 1/3 Nb 2/3 O 3 (PMN) Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.736, year: 2014

5 CFR 551.301 - Minimum wage.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Minimum wage. 551.301 Section 551.301... FAIR LABOR STANDARDS ACT Minimum Wage Provisions Basic Provision § 551.301 Minimum wage. (a)(1) Except... employees wages at rates not less than the minimum wage specified in section 6(a)(1) of the Act for all...

Development of multiple scattering lidar to retrieve cloud extinction and size information

International Nuclear Information System (INIS)

Kim, Dukhyeon; Cheong, Hai Du; Kim, Young Gi; Park, Sun Ho

2008-01-01

Traditional Mie scattering cloud lidar have some limitations because of multiple scattering effects. Because this multiple scattering effects induce depolarization of spherical particle and enhancement of extinction coefficient. We cannot measure the phase of water with depolarization lidar, and also cannot measure the extinction coefficient with single FOV(Field Of View)Mie cloud lidar system. In the study, we have developed a multiple field of view Mie cloud liar system which can give many information about the cloud droplet such as cloud effective size, cloud number density, extinction coefficient of cloud, and phase of water through the correction of multiple scattering effects. For this purpose, we have developed a multiple field of view lidar system which composed of 32 different pinholes. Figure 1 shows the schematic diagram and picture of pinholes which start from 100μm to 8mm. Pihole is located at the focal plane of the parabolic mirror, in this case the minimum FOV is 67μrad, maximum FOV is 5.3 mrad. Figure 2 shows Monte Carlo simulation of the multiple scattering photons vs. cloud depth. In this calculation we assumed that wavelength normalized aerosol size(x)is 100, and density of cloud (extinction efficiency)is 0.01m"-1". By measuring FOV dependent signals and aerosol extinction coefficient we can extract effective droplet size through following equations. Here θ"d"is aerosol effective size, and z"j", f, Θ(z)are height, aerosol density dependent function, and angular size of lidar signal at the height z. Finally. f(z)depends on the light mean free path and number of scattering

Elastic nucleon-deuteron scattering and breakup with chiral forces

Directory of Open Access Journals (Sweden)

Witała Henryk

2016-01-01

Full Text Available Results on three-nucleon (3N elastic scattering and breakup below the pion production threshold are discussed. The large discrepancies found between a theory based on numerical solutions of 3N Faddeev equations with standard nucleon-nucleon (NN potentials only and data point to the need for three-nucleon forces (3NF’s. This notion is supported by the fact that another possible reason for the discrepancies in elastic nucleon-deuteron (Nd scattering, relativistic effects, turned out to be small. Results for a new generation of chiral NN forces (up to N4LO together with theoretical truncation errors are shown. They support conclusions obtained with standard NN potentials

Cooperative scattering of scalar waves by optimized configurations of point scatterers

Science.gov (United States)

Schäfer, Frank; Eckert, Felix; Wellens, Thomas

2017-12-01

We investigate multiple scattering of scalar waves by an ensemble of N resonant point scatterers in three dimensions. For up to N = 21 scatterers, we numerically optimize the positions of the individual scatterers, to maximize the total scattering cross section for an incoming plane wave, on the one hand, and to minimize the decay rate associated to a long-lived scattering resonance, on the other. In both cases, the optimum is achieved by configurations where all scatterers are placed on a line parallel to the direction of the incoming plane wave. The associated maximal scattering cross section increases quadratically with the number of scatterers for large N, whereas the minimal decay rate—which is realized by configurations that are not the same as those that maximize the scattering cross section—decreases exponentially as a function of N. Finally, we also analyze the stability of our optimized configurations with respect to small random displacements of the scatterers. These results demonstrate that optimized configurations of scatterers bear a considerable potential for applications such as quantum memories or mirrors consisting of only a few atoms.

A Computable Plug-In Estimator of Minimum Volume Sets for Novelty Detection

KAUST Repository

Park, Chiwoo; Huang, Jianhua Z.; Ding, Yu

2010-01-01

A minimum volume set of a probability density is a region of minimum size among the regions covering a given probability mass of the density. Effective methods for finding the minimum volume sets are very useful for detecting failures or anomalies in commercial and security applications-a problem known as novelty detection. One theoretical approach of estimating the minimum volume set is to use a density level set where a kernel density estimator is plugged into the optimization problem that yields the appropriate level. Such a plug-in estimator is not of practical use because solving the corresponding minimization problem is usually intractable. A modified plug-in estimator was proposed by Hyndman in 1996 to overcome the computation difficulty of the theoretical approach but is not well studied in the literature. In this paper, we provide theoretical support to this estimator by showing its asymptotic consistency. We also show that this estimator is very competitive to other existing novelty detection methods through an extensive empirical study. ©2010 INFORMS.

A Computable Plug-In Estimator of Minimum Volume Sets for Novelty Detection

KAUST Repository

Park, Chiwoo

2010-10-01

A minimum volume set of a probability density is a region of minimum size among the regions covering a given probability mass of the density. Effective methods for finding the minimum volume sets are very useful for detecting failures or anomalies in commercial and security applications-a problem known as novelty detection. One theoretical approach of estimating the minimum volume set is to use a density level set where a kernel density estimator is plugged into the optimization problem that yields the appropriate level. Such a plug-in estimator is not of practical use because solving the corresponding minimization problem is usually intractable. A modified plug-in estimator was proposed by Hyndman in 1996 to overcome the computation difficulty of the theoretical approach but is not well studied in the literature. In this paper, we provide theoretical support to this estimator by showing its asymptotic consistency. We also show that this estimator is very competitive to other existing novelty detection methods through an extensive empirical study. ©2010 INFORMS.

Non-eikonal corrections for the scattering of spin-one particles

Energy Technology Data Exchange (ETDEWEB)

Gaber, M.W.; Wilkin, C. [Department of Physics and Astronomy, University College London, WC1E 6BT, London (United Kingdom); Al-Khalili, J.S. [Department of Physics, University of Surrey, GU2 7XH, Guildford, Surrey (United Kingdom)

2004-08-01

The Wallace Fourier-Bessel expansion of the scattering amplitude is generalised to the case of the scattering of a spin-one particle from a potential with a single tensor coupling as well as central and spin-orbit terms. A generating function for the eikonal-phase (quantum) corrections is evaluated in closed form. For medium-energy deuteron-nucleus scattering, the first-order correction is dominant and is shown to be significant in the interpretation of analysing power measurements. This conclusion is supported by a numerical comparison of the eikonal observables, evaluated with and without corrections, with those obtained from a numerical resolution of the Schroedinger equation for d-{sup 58}Ni scattering at incident deuteron energies of 400 and 700 MeV. (orig.)

Ion trapping in one-minimum potentials via charge-exchange collisions

International Nuclear Information System (INIS)

Maier, H.; Kuhn, S.

1994-01-01

A (1 d, 2 v), electrostatic, kinetics model for time-independent single-ended Q-machine states with a positively biased cold plate and a single internal minimum near the hot plate is presented. While the electrons are treated as collisionless, charge-exchange collisions between the ions and the neutral background gas atoms are taken into account by means of a linearized Boltzmann collision operator. The self-consistent plasma states are found by using an iterative analytic-numerical trajectory-simulation method in which the charge-density and potential distributions are alternately determined numerical results clearly demonstrate the sensitive role that trapped ions play in shaping the microscopic and macroscopic properties of the dc states under study. The trapped-ion distributions themselves are shown to be controlled critically by the detailed scattering conditions, which in turn are determined by the choice of the background properties. (author). 10 refs, 3 figs

Inelastic scattering with Chebyshev polynomials and preconditioned conjugate gradient minimization.

Science.gov (United States)

Temel, Burcin; Mills, Greg; Metiu, Horia

2008-03-27

We describe and test an implementation, using a basis set of Chebyshev polynomials, of a variational method for solving scattering problems in quantum mechanics. This minimum error method (MEM) determines the wave function Psi by minimizing the least-squares error in the function (H Psi - E Psi), where E is the desired scattering energy. We compare the MEM to an alternative, the Kohn variational principle (KVP), by solving the Secrest-Johnson model of two-dimensional inelastic scattering, which has been studied previously using the KVP and for which other numerical solutions are available. We use a conjugate gradient (CG) method to minimize the error, and by preconditioning the CG search, we are able to greatly reduce the number of iterations necessary; the method is thus faster and more stable than a matrix inversion, as is required in the KVP. Also, we avoid errors due to scattering off of the boundaries, which presents substantial problems for other methods, by matching the wave function in the interaction region to the correct asymptotic states at the specified energy; the use of Chebyshev polynomials allows this boundary condition to be implemented accurately. The use of Chebyshev polynomials allows for a rapid and accurate evaluation of the kinetic energy. This basis set is as efficient as plane waves but does not impose an artificial periodicity on the system. There are problems in surface science and molecular electronics which cannot be solved if periodicity is imposed, and the Chebyshev basis set is a good alternative in such situations.

Neutron scattering. Lectures

International Nuclear Information System (INIS)

Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

2012-01-01

The following topics are dealt with: Neutron scattering in contemporary research, neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

Experimental investigation of quantum effects in time-resolved resonance Rayleigh scattering from quantum well excitons

DEFF Research Database (Denmark)

Birkedal, Dan; Shah, Jagdeep; Shchegrov, Andrei V.

2000-01-01

Resonant Rayleigh scattering from quantum well excitons is investigated using ultrafast spectral interferometry. We isolate the coherent Rayleigh scattering from incoherent luminescence in a single speckle. Averaging the resonant Rayleigh intensity over several speckles allows us to identify...... features in support of quantum corrections to the classical description of the underlying scattering process....

Neutron scattering (progress report) January - December 1991

International Nuclear Information System (INIS)

Buehrer, W.; Fischer, P.; Furrer, A.

1992-02-01

Progress made by the Laboratory for Neutron Scattering of the Swiss Federal Institute of Technology during the year 1991 in the fields of high-T c superconductors, materials science, magnetism, structural research, lattice dynamics, phase transitions, instrumental and support activities is reported. figs., tabs., refs

Elastic pion-nucleon P-wave scattering in soliton models

International Nuclear Information System (INIS)

Holzwarth, G.

1990-01-01

The equivalence of low-energy P-wave πN scattering in soliton models with the well-established Δ-isobar model is shown to hold even if all constraints on redundant collective variables are ignored. This provides strong support for the unusual (time-derivative) form of meson-baryon coupling in such models, and for the expectation that the soliton description of πN-scattering can be reliably extended down to pion threshold energies in a technically simple way. (orig.)

Beam-guiding system for Rutherford-scattering diagnostic at TEXTOR

International Nuclear Information System (INIS)

Cosler, A; Bertschinger, G.; Kemmereit, E.; Ven, H.W. van der; Barbian, E.P.; Blokland, A.A.E. van

1988-01-01

A beam-guiding system for a neutral beam probe diagnostic has been developed for implementation at TEXTOR. Energetic helium atoms scattered on the plasma ions provide information about the local ion temperature. Time resolution is attained by sampling scattered particles measured individually by a time-of-flight analyser. The mechanical supports have been designed for lateral and angular movement of the beam-guiding system to be used for radial scanning of the torus and for optimization of the scattering angle. The parameters of the probing beam itself can be controlled jby a small beam profile diagnsotic. Provisions are made to observe separately the radial or axial component of the ion velocity distribution. (author). 10 refs.; 7 figs

Solar Cycle Variability and Grand Minima Induced by Joy's Law Scatter

Science.gov (United States)

Karak, Bidya Binay; Miesch, Mark S.

2017-08-01

The strength of the solar cycle varies from one cycle to another in an irregular manner and the extreme example of this irregularity is the Maunder minimum when Sun produced only a few spots for several years. We explore the cause of these variabilities using a 3D Babcock--Leighton dynamo. In this model, based on the toroidal flux at the base of the convection zone, bipolar magnetic regions (BMRs) are produced with flux, tilt angle, and time of emergence all obtain from their observed distributions. The dynamo growth is limited by a tilt quenching.The randomnesses in the BMR emergences make the poloidal field unequal and eventually cause an unequal solar cycle. When observed fluctuations of BMR tilts around Joy's law, i.e., a standard deviation of 15 degrees, are considered, our model produces a variation in the solar cycle comparable to the observed solar cycle variability. Tilt scatter also causes occasional Maunder-like grand minima, although the observed scatter does not reproduce correct statistics of grand minima. However, when we double the tilt scatter, we find grand minima consistent with observations. Importantly, our dynamo model can operate even during grand minima with only a few BMRs, without requiring any additional alpha effect.

Minimum income protection in the Netherlands

NARCIS (Netherlands)

van Peijpe, T.

2009-01-01

This article offers an overview of the Dutch legal system of minimum income protection through collective bargaining, social security, and statutory minimum wages. In addition to collective agreements, the Dutch statutory minimum wage offers income protection to a small number of workers. Its

Electric field measurements at near-atmospheric pressure by coherent Raman scattering of laser beams

International Nuclear Information System (INIS)

Ito, Tsuyohito; Kobayashi, Kazunobu; Hamaguchi, Satoshi; Mueller, Sarah; Czarnetzki, Uwe

2010-01-01

Electric field measurements at near-atmospheric pressure environments based on electric-field induced Raman scattering are applied to repetitively pulsed nanosecond discharges. The results have revealed that the peak electric field near the centre of the gap is almost independent of the applied voltage. Minimum sustainable voltage measurements suggests that, at each discharge pulse, charged particles that remain from the previous pulse serve as discharge seeds and play an important role for generation of uniform glow-like discharges.

A compact multichannel spectrometer for Thomson scattering

Energy Technology Data Exchange (ETDEWEB)

Schoenbeck, N. L.; Schlossberg, D. J.; Dowd, A. S.; Fonck, R. J.; Winz, G. R. [Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)

2012-10-15

The availability of high-efficiency volume phase holographic (VPH) gratings and intensified CCD (ICCD) cameras have motivated a simplified, compact spectrometer for Thomson scattering detection. Measurements of T{sub e} < 100 eV are achieved by a 2971 l/mm VPH grating and measurements T{sub e} > 100 eV by a 2072 l/mm VPH grating. The spectrometer uses a fast-gated ({approx}2 ns) ICCD camera for detection. A Gen III image intensifier provides {approx}45% quantum efficiency in the visible region. The total read noise of the image is reduced by on-chip binning of the CCD to match the 8 spatial channels and the 10 spectral bins on the camera. Three spectrometers provide a minimum of 12 spatial channels and 12 channels for background subtraction.

Observation of mass loss in R CrB during the visual light minimum

International Nuclear Information System (INIS)

Kameswara Rao, N.

1981-01-01

Visual light minima of R CrB stars are thought to be caused by the formation of circumstellar dust. It has been observed at the time of the light minimum that there is difference in the reddening between the descending and the rising branches of the light curves. The extinction during the descending branch tends to be neutral with not much of colour change, while there occurs redder colours during the recovery part of the light curve (Forrest 1974). It is probable that the gas causing the broad emission lines with Ne approximately 5 x 10 11 cm -3 also produces the neutral extinction due to electron scattering. An extinction of 4.5 mag can result if this region is assumed to extend to 2R. (Auth.)

Core-control assembly with a fixed fuel support

International Nuclear Information System (INIS)

Challberg, R.C.

1993-01-01

A core-control assembly is described comprising: a control rod having a plurality of blades; a control-rod guide tube for guiding vertical motion of said control rod; a fuel support for supporting fuel bundles separated by said blades, said fuel support having an aperture conforming to a cross section of said control rod through said blades for preventing rotational movement of said control rod to a decoupling orientation when said control rod is between a maximum power position and a minimum power position, said minimum power position being above said maximum power position, said fuel support being supported by said control-rod guide tube; control-rod drive means for controlling vertical motion of said control rod, said control-rod drive means providing for vertical motion between said maximum power position and said minimum power position, said control-rod drive means providing for vertical movement to a decoupling position, said decoupling position being no lower than said minimum power position, said decoupling position being at a level sufficient to permit said control rod to rotate to a decoupling orientation relative to said fuel support; and coupling means for coupling said control rod to said control rod drive means, said coupling means being releasable by rotational movement of said control rod to said decoupling orientation relative to said control-rod drive means

Light scattering reviews 8 radiative transfer and light scattering

CERN Document Server

Kokhanovsky, Alexander A

2013-01-01

Light scattering review (vol 8) is aimed at the presentation of recent advances in radiative transfer and light scattering optics. The topics to be covered include: scattering of light by irregularly shaped particles suspended in atmosphere (dust, ice crystals), light scattering by particles much larger as compared the wavelength of incident radiation, atmospheric radiative forcing, astrophysical radiative transfer, radiative transfer and optical imaging in biological media, radiative transfer of polarized light, numerical aspects of radiative transfer.

Effective temperatures and scattering cross sections in water mixtures determined by Deep Inelastic Neutron Scattering

International Nuclear Information System (INIS)

Dawidowski, J.; Rodríguez Palomino, L.A.; Márquez Damián, J.I.; Blostein, J.J.; Cuello, G.J.

2016-01-01

Highlights: • Effective temperatures of atoms can be determined by the DINS technique. • This is the first time that such application of this experimental technique is made. • This technique is able to measure the known cross sections of the atoms. • No anomalous cross section was found, at variance with Dreissmann’s et al. claims. - Abstract: The present work shows a series of results of Deep Inelastic Neutron Scattering (DINS) experiments on light and heavy water mixtures performed at the spectrometer VESUVIO (Rutherford Appleton Laboratory, UK) employing an analysis method based on the information provided by individual detectors in forward and backward scattering positions. We investigated the effective temperatures of the different atoms composing the samples, a magnitude of considerable interest for Nuclear Engineering. The peak intensities and their relation with the bound-atom cross sections is analyzed, showing a good agreement with tabulated values which supports the use of this technique as non-destructive mass spectrometry. Previous results in the determination of scattering cross sections by this technique (known in the literature) that were at variance with the present findings are commented.

X-ray, neutron, and electron scattering. Report of a materials sciences workshop

International Nuclear Information System (INIS)

1977-08-01

The ERDA Workshop on X-ray, Neutron, and Electron Scattering to assess needs and establish priorities for energy-related basic research on materials. The general goals of the Workshop were: (1) to review various energy technologies where x-ray, neutron, and electron scattering techniques might make significant contributions, (2) to identify present and future materials problems in the energy technologies and translate these problems into requirements for basic research by x-ray, neutron, and electron scattering techniques, (3) to recommend research areas utilizing these three scattering techniques that should be supported by the DPR Materials Sciences Program, and (4) to assign priorities to these research areas

Scattering properties of a PT dipole

Czech Academy of Sciences Publication Activity Database

Staliunas, K.; Markoš, P.; Kuzmiak, Vladimír

2017-01-01

Roč. 96, č. 4 (2017), č. článku 043852. ISSN 2469-9926 R&D Projects: GA ČR(CZ) GA16-00329S Institutional support: RVO:67985882 Keywords : Scattering field * Electromagnetic response * Refractive index Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering OBOR OECD: Electrical and electronic engineering Impact factor: 2.925, year: 2016

Minimum acceptable face velocities of laboratory fume hoods and guidelines for their classification

International Nuclear Information System (INIS)

Bolton, N.E.; Porter, W.E.; Alcorn, S.P.; Everett, W.S.; Hunt, J.B.; Morehead, J.F.; Higdon, H.F.

1978-06-01

Data developed to support the requirement of a 100 LFM minimum face velocity requirement for laboratory fume hoods are summarized. Also included is a description of the Y-12 test hood as well as guidelines for a hood classification scheme

1D energy transport in a strongly scattering laboratory model

International Nuclear Information System (INIS)

Wijk, Kasper van; Scales, John A.; Haney, Matthew

2004-01-01

Radiative transfer (RT) theory is often invoked to describe energy propagation in strongly scattering media. Fitting RT to measured wave field intensities is rather different at late times, when the transport is diffusive, than at intermediate times (around one extinction mean free time), when ballistic and diffusive behavior coexist. While there are many examples of late-time RT fits, we describe ultrasonic multiple scattering measurements with RT over the entire range of times--from ballistic to diffusive. In addition to allowing us to retrieve the scattering and absorption mean free paths independently, our results also support theoretical predictions in 1D that suggest an intermediate regime of diffusive (nonlocalized) behavior

Scatter-Reducing Sounding Filtration Using a Genetic Algorithm and Mean Monthly Standard Deviation

Science.gov (United States)

Mandrake, Lukas

2013-01-01

Retrieval algorithms like that used by the Orbiting Carbon Observatory (OCO)-2 mission generate massive quantities of data of varying quality and reliability. A computationally efficient, simple method of labeling problematic datapoints or predicting soundings that will fail is required for basic operation, given that only 6% of the retrieved data may be operationally processed. This method automatically obtains a filter designed to reduce scatter based on a small number of input features. Most machine-learning filter construction algorithms attempt to predict error in the CO2 value. By using a surrogate goal of Mean Monthly STDEV, the goal is to reduce the retrieved CO2 scatter rather than solving the harder problem of reducing CO2 error. This lends itself to improved interpretability and performance. This software reduces the scatter of retrieved CO2 values globally based on a minimum number of input features. It can be used as a prefilter to reduce the number of soundings requested, or as a post-filter to label data quality. The use of the MMS (Mean Monthly Standard deviation) provides a much cleaner, clearer filter than the standard ABS(CO2-truth) metrics previously employed by competitor methods. The software's main strength lies in a clearer (i.e., fewer features required) filter that more efficiently reduces scatter in retrieved CO2 rather than focusing on the more complex (and easily removed) bias issues.

Neutron scattering. Lectures

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)

Neutron scattering. Lectures

International Nuclear Information System (INIS)

Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

2010-01-01

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)

CRAPONE, Optical Model Potential Fit of Neutron Scattering Data

International Nuclear Information System (INIS)

Fabbri, F.; Fratamico, G.; Reffo, G.

2004-01-01

1 - Description of problem or function: Automatic search for local and non-local optical potential parameters for neutrons. Total, elastic, differential elastic cross sections, l=0 and l=1 strength functions and scattering length can be considered. 2 - Method of solution: A fitting procedure is applied to different sets of experimental data depending on the local or non-local approximation chosen. In the non-local approximation the fitting procedure can be simultaneously performed over the whole energy range. The best fit is obtained when a set of parameters is found where CHI 2 is at its minimum. The solution of the system equations is obtained by diagonalization of the matrix according to the Jacobi method

Neutron scattering. Lectures

International Nuclear Information System (INIS)

Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

2013-01-01

The following topics are dealt with: Neutron sources, symmetry of crystals, nanostructures investigated by small-angle neutron scattering, structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic neutron scattering, strongly correlated electrons, polymer dynamics, applications of neutron scattering. (HSI)

Spectrometer Development in Support of Thomson Scattering Investigations for the Helicon Plasma Experiment (HPX)

Science.gov (United States)

Sandri, Eva; Davies, Richard; Azzari, Phil; Frank, John; Frank, Jackson; James, Royce; Hopson, Jordon; Duke-Tinson, Omar; Paolino, Richard; Sherman, Justin; Wright, Erin; Turk, Jeremy

2016-10-01

Now that reproducible plasmas have been created on the Helicon Plasma Experiment (HPX) at the Coast Guard Academy Plasma Laboratory (CGAPL), a high-performance spectrometer utilizing volume-phase-holographic (VPH) grating and a charge coupled device (CCD) camera with a range of 380-1090 nm and resolution of 1024x1024 is being assembled. This spectrometer will collect doppler shifted photons created by exciting the plasma with the first harmonic of a 2.5 J Nd:YAG laser at a wavelength of 1064 nm. Direct measurements of the plasma's temperature and density will be determined using HPX's Thomson Scattering (TS) system as a single spatial point diagnostic. TS has the capability of determining plasma properties on short time scales and will be used to create a robust picture of the internal plasma parameters. A prototype spectrometer has been constructed to explore the Andor CCD camera's resolution and sensitivity. Concurrently, through intensive study of the high energy TS system, safety protocols and standard operation procedures (SOP) for the Coast Guard's largest and most powerful Laser have been developed. The current status of the TS SOP, diagnostic development, and the collection optic's spectrometer will be reported. Supported by U.S. DEPS Grant [HEL-JTO] PRWJFY15-16.

Neutron scattering. Lectures

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, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

Neutron scattering. Lectures

International Nuclear Information System (INIS)

Brueckel, Thomas; Heger, Gernot; Richter, Dieter; Roth, Georg; Zorn, Reiner

2010-01-01

The following topics are dealt with: Neutron sources, symmetry of crystals, diffraction, nanostructures investigated by small-angle neutron scattering, the structure of macromolecules, spin dependent and magnetic scattering, structural analysis, neutron reflectometry, magnetic nanostructures, inelastic scattering, strongly correlated electrons, dynamics of macromolecules, applications of neutron scattering. (HSI)

Pragmatic, consensus-based minimum standards and structured interview to guide the selection and development of cancer support group leaders: a protocol paper.

Science.gov (United States)

Pomery, Amanda; Schofield, Penelope; Xhilaga, Miranda; Gough, Karla

2017-06-30

Across the globe, peer support groups have emerged as a community-led approach to accessing support and connecting with others with cancer experiences. Little is known about qualities required to lead a peer support group or how to determine suitability for the role. Organisations providing assistance to cancer support groups and their leaders are currently operating independently, without a standard national framework or published guidelines. This protocol describes the methods that will be used to generate pragmatic consensus-based minimum standards and an accessible structured interview with user manual to guide the selection and development of cancer support group leaders. We will: (A) identify and collate peer-reviewed literature that describes qualities of support group leaders through a systematic review; (B) content analyse eligible documents for information relevant to requisite knowledge, skills and attributes of group leaders generally and specifically to cancer support groups; (C) use an online reactive Delphi method with an interdisciplinary panel of experts to produce a clear, suitable, relevant and appropriate structured interview comprising a set of agreed questions with behaviourally anchored rating scales; (D) produce a user manual to facilitate standard delivery of the structured interview; (E) pilot the structured interview to improve clinical utility; and (F) field test the structured interview to develop a rational scoring model and provide a summary of existing group leader qualities. The study is approved by the Department Human Ethics Advisory Group of The University of Melbourne. The study is based on voluntary participation and informed written consent, with participants able to withdraw at any time. The results will be disseminated at research conferences and peer review journals. Presentations and free access to the developed structured interview and user manual will be available to cancer agencies. © Article author(s) (or their

Understanding the Minimum Wage: Issues and Answers.

Science.gov (United States)

Employment Policies Inst. Foundation, Washington, DC.

This booklet, which is designed to clarify facts regarding the minimum wage's impact on marketplace economics, contains a total of 31 questions and answers pertaining to the following topics: relationship between minimum wages and poverty; impacts of changes in the minimum wage on welfare reform; and possible effects of changes in the minimum wage…

Youth minimum wages and youth employment

NARCIS (Netherlands)

Marimpi, Maria; Koning, Pierre

2018-01-01

This paper performs a cross-country level analysis on the impact of the level of specific youth minimum wages on the labor market performance of young individuals. We use information on the use and level of youth minimum wages, as compared to the level of adult minimum wages as well as to the median

Minimum Map of Social Institutional Network: a multidimensional strategy for research in Nursing

Directory of Open Access Journals (Sweden)

Diene Monique Carlos

2016-06-01

Full Text Available Objective To analyze the use of methodological strategies in qualitative research - Minimum Maps of Social Institutional Network, as proposed to understand the phenomena in the multidimensional perspective. Method Methodological theoretical essay in which we aimed to reflect on the use of innovative methodological strategies in nursing research, supported in Complex Paradigm fundamentals. Results The minimum map of Social Institutional External Network aims to identify institutional linkages and gaps for the intervention work of the surveyed institutions. The use of these maps provided important advances in know-how qualitative research in Health and Nursing. Conclusions In this perspective, the use of minimum Social Intitutional Network maps can be stimulated and enhanced to meet the current demands of the contemporary world, particularly for its flexibility in adapting to various research subjects; breadth and depth of discussion; and possibilities with health services.

Discretization of space and time: determining the values of minimum length and minimum time

OpenAIRE

Roatta , Luca

2017-01-01

Assuming that space and time can only have discrete values, we obtain the expression of the minimum length and the minimum time interval. These values are found to be exactly coincident with the Planck's length and the Planck's time but for the presence of h instead of ħ .

Minimum wage development in the Russian Federation

OpenAIRE

Bolsheva, Anna

2012-01-01

The aim of this paper is to analyze the effectiveness of the minimum wage policy at the national level in Russia and its impact on living standards in the country. The analysis showed that the national minimum wage in Russia does not serve its original purpose of protecting the lowest wage earners and has no substantial effect on poverty reduction. The national subsistence minimum is too low and cannot be considered an adequate criterion for the setting of the minimum wage. The minimum wage d...

Certain theories of multiple scattering in random media of discrete scatterers

International Nuclear Information System (INIS)

Olsen, R.L.; Kharadly, M.M.Z.; Corr, D.G.

1976-01-01

New information is presented on the accuracy of the heuristic approximations in two important theories of multiple scattering in random media of discrete scatterers: Twersky's ''free-space'' and ''two-space scatterer'' formalisms. Two complementary approaches, based primarily on a one-dimensional model and the one-dimensional forms of the theories, are used. For scatterer distributions of low average density, the ''heuristic'' asymptotic forms for the coherent field and the incoherent intensity are compared with asymptotic forms derived from a systematic analysis of the multiple scattering processes. For distributions of higher density, both in the average number of scatterers per wavelength and in the degree of packing of finite-size scatterers, the analysis is carried out ''experimentally'' by means of a Monte Carlo computer simulation. Approximate series expressions based on the systematic approach are numerically evaluated along with the heuristic expressions. The comparison (for both forward- and back-scattered field moments) is made for the worst-case conditions of strong multiple scattering for which the theories have not previously been evaluated. Several significant conclusions are drawn which have certain practical implications: in application of the theories to describe some of the scattering phenomena which occur in the troposphere, and in the further evaluation of the theories using experiments on physical models

Can households earning minimum wage in Nova Scotia afford a nutritious diet?

Science.gov (United States)

Williams, Patricia L; Johnson, Christine P; Kratzmann, Meredith L V; Johnson, C Shanthi Jacob; Anderson, Barbara J; Chenhall, Cathy

2006-01-01

To assess the affordability of a nutritious diet for households earning minimum wage in Nova Scotia. Food costing data were collected in 43 randomly selected grocery stores throughout NS in 2002 using the National Nutritious Food Basket (NNFB). To estimate the affordability of a nutritious diet for households earning minimum wage, average monthly costs for essential expenses were subtracted from overall income to see if enough money remained for the cost of the NNFB. This was calculated for three types of household: 1) two parents and two children; 2) lone parent and two children; and 3) single male. Calculations were also made for the proposed 2006 minimum wage increase with expenses adjusted using the Consumer Price Index (CPI). The monthly cost of the NNFB priced in 2002 for the three types of household was 572.90 dollars, 351.68 dollars, and 198.73 dollars, respectively. Put into the context of basic living, these data showed that Nova Scotians relying on minimum wage could not afford to purchase a nutritious diet and meet their basic needs, placing their health at risk. These basic expenses do not include other routine costs, such as personal hygiene products, household and laundry cleaners, and prescriptions and costs associated with physical activity, education or savings for unexpected expenses. People working at minimum wage in Nova Scotia have not had adequate income to meet basic needs, including a nutritious diet. The 2006 increase in minimum wage to 7.15 dollars/hr is inadequate to ensure that Nova Scotians working at minimum wage are able to meet these basic needs. Wage increases and supplements, along with supports for expenses such as childcare and transportation, are indicated to address this public health problem.

The impact of the UK National Minimum Wage on mental health

Directory of Open Access Journals (Sweden)

Christoph Kronenberg

2017-12-01

Full Text Available Despite an emerging literature, there is still sparse and mixed evidence on the wider societal benefits of Minimum Wage policies, including their effects on mental health. Furthermore, causal evidence on the relationship between earnings and mental health is limited. We focus on low-wage earners, who are at higher risk of psychological distress, and exploit the quasi-experiment provided by the introduction of the UK National Minimum Wage (NMW to identify the causal impact of wage increases on mental health. We employ difference-in-differences models and find that the introduction of the UK NMW had no effect on mental health. Our estimates do not appear to support earlier findings which indicate that minimum wages affect mental health of low-wage earners. A series of robustness checks accounting for measurement error, as well as treatment and control group composition, confirm our main results. Overall, our findings suggest that policies aimed at improving the mental health of low-wage earners should either consider the non-wage characteristics of employment or potentially larger wage increases.

The impact of the UK National Minimum Wage on mental health.

Science.gov (United States)

Kronenberg, Christoph; Jacobs, Rowena; Zucchelli, Eugenio

2017-12-01

Despite an emerging literature, there is still sparse and mixed evidence on the wider societal benefits of Minimum Wage policies, including their effects on mental health. Furthermore, causal evidence on the relationship between earnings and mental health is limited. We focus on low-wage earners, who are at higher risk of psychological distress, and exploit the quasi-experiment provided by the introduction of the UK National Minimum Wage (NMW) to identify the causal impact of wage increases on mental health. We employ difference-in-differences models and find that the introduction of the UK NMW had no effect on mental health. Our estimates do not appear to support earlier findings which indicate that minimum wages affect mental health of low-wage earners. A series of robustness checks accounting for measurement error, as well as treatment and control group composition, confirm our main results. Overall, our findings suggest that policies aimed at improving the mental health of low-wage earners should either consider the non-wage characteristics of employment or potentially larger wage increases.

Minimum emittance of three-bend achromats

International Nuclear Information System (INIS)

Li Xiaoyu; Xu Gang

2012-01-01

The calculation of the minimum emittance of three-bend achromats (TBAs) made by Mathematical software can ignore the actual magnets lattice in the matching condition of dispersion function in phase space. The minimum scaling factors of two kinds of widely used TBA lattices are obtained. Then the relationship between the lengths and the radii of the three dipoles in TBA is obtained and so is the minimum scaling factor, when the TBA lattice achieves its minimum emittance. The procedure of analysis and the results can be widely used in achromats lattices, because the calculation is not restricted by the actual lattice. (authors)

Scattering transform and LSPTSVM based fault diagnosis of rotating machinery

Science.gov (United States)

Ma, Shangjun; Cheng, Bo; Shang, Zhaowei; Liu, Geng

2018-05-01

This paper proposes an algorithm for fault diagnosis of rotating machinery to overcome the shortcomings of classical techniques which are noise sensitive in feature extraction and time consuming for training. Based on the scattering transform and the least squares recursive projection twin support vector machine (LSPTSVM), the method has the advantages of high efficiency and insensitivity for noise signal. Using the energy of the scattering coefficients in each sub-band, the features of the vibration signals are obtained. Then, an LSPTSVM classifier is used for fault diagnosis. The new method is compared with other common methods including the proximal support vector machine, the standard support vector machine and multi-scale theory by using fault data for two systems, a motor bearing and a gear box. The results show that the new method proposed in this study is more effective for fault diagnosis of rotating machinery.

Inelastic scattering in condensed matter with high intensity Moessbauer radiation

International Nuclear Information System (INIS)

Yelon, W.B.; Schupp, G.

1990-10-01

We give a progress report for the work which has been carried out in the last three years with DOE support. A facility for high-intensity Moessbauer scattering is now fully operational at the University of Missouri Research Reactor (MURR) as well as facility at Purdue, using special isotopes produced at MURR. High precision, fundamental Moessbauer effect studies have been carried out using scattering to filter the unwanted radiation. These have led to a new Fourier transform method for describing Moessbauer effect (ME) lineshape and a direct method of fitting ME data to the convolution integral. These methods allow complete correction for source resonance self absorption (SRSA) and the accurate representation of interference effects that add an asymmetric component to the ME lines. We have begun applying these techniques to attenuated ME sources whose central peak has been attenuated by stationary resonant absorbers, to more precisely determine interference parameters and line-shape behavior in the resonance asymptotic region. This analysis is important to both the fundamental ME studies and to scattering studies for which a deconvolution is essential for extracting the correct recoilless fractions and interference parameters. A number of scattering studies have been successfully carried out including a study of the thermal diffuse scattering in Si, which led to an analysis of the resolution function for gamma-ray scattering. Also studied was the anharmonic motion in Na and the satellite reflection Debye-Waller factor in TaS 2 , which indicate phason rather than phonon behavior. We have begun quasielastic diffusion studies in viscous liquids and current results are summarized. These advances, coupled to our improvements in MIcrofoil Conversion Electron spectroscopy lay the foundation for the proposed research outlined in this request for a three-year renewal of DOE support

Gamma scattering in condensed matter with high intensity Moessbauer radiation

International Nuclear Information System (INIS)

1990-01-01

We give a progress report for the work which has been carried out in the last three years with DOE support. A facility for high-intensity Moessbauer scattering is now fully operational at the University of Missouri Research Reactor (MURR) as well as a facility at Purdue, using special isotopes produced at MURR. High precision, fundamental Moessbauer effect studies have been carried out using scattering to filter the unwanted radiation. These have led to a new Fourier transform method for describing Moessbauer effect (ME) lineshape and a direct method of fitting ME data to the convolution integral. These methods allow complete correction for source resonance self absorption (SRSA) and the accurate representation of interference effects that add an asymmetric component to the ME lines. We have begun applying these techniques to attenuated ME sources whose central peak has been attenuated by stationary resonant absorbers, to more precisely determine interference parameters and line-shape behavior in the resonance asymptotic region. This analysis is important to both the fundamental ME studies and to scattering studies for which a deconvolution is essential for extracting the correct recoilless fractions and interference parameters. A number of scattering studies have been successfully carried out including a study of the thermal diffuse scattering in Si, which led to an analysis of the resolution function for gamma-ray scattering. Also studied was the anharmonic motion in Na and the satellite reflection Debye-Waller factor in TaS 2 , which indicate phason rather than phonon behavior. We have begun quasielastic diffusion studies in viscous liquids and current results are summarized. These advances, coupled to our improvements in MIcrofoil Conversion Electron spectroscopy lay the foundation for the proposed research outlined in this request for a three-year renewal of DOE support

30 CFR 57.19021 - Minimum rope strength.

Science.gov (United States)

2010-07-01

... feet: Minimum Value=Static Load×(7.0−0.001L) For rope lengths 3,000 feet or greater: Minimum Value=Static Load×4.0. (b) Friction drum ropes. For rope lengths less than 4,000 feet: Minimum Value=Static Load×(7.0−0.0005L) For rope lengths 4,000 feet or greater: Minimum Value=Static Load×5.0. (c) Tail...

30 CFR 56.19021 - Minimum rope strength.

Science.gov (United States)

2010-07-01

... feet: Minimum Value=Static Load×(7.0-0.001L) For rope lengths 3,000 feet or greater: Minimum Value=Static Load×4.0 (b) Friction drum ropes. For rope lengths less than 4,000 feet: Minimum Value=Static Load×(7.0-0.0005L) For rope lengths 4,000 feet or greater: Minimum Value=Static Load×5.0 (c) Tail ropes...

Polarimetric observations of the R Coronae Borealis during its minimum in 1977

Energy Technology Data Exchange (ETDEWEB)

Efimov, Y S

1980-01-01

The photometry and polarimetry R CrB in five ranges of visible spectra during its brightness minimum in 1977 was made. An extremely large (up to 14%) and variable linear polarization with a practically constant position angle was found. The variations of the wavelength dependence of polarization was studied. It is shown that the wavelength dependence of polarization becomes steeper when the degree of polarization is risen. The polarization maximum shifts to the longer wavelength in comparison to its position during increasing star brightness time interval. Strong correlation between brightness and polarization variations was found: the polarization is declined when the star becomes brighter and visa versa. A light scattering by small particles (approximately 0.07 ..mu..m) dominates when the star brightness increases and the particles become larger (approximately 0.10 ..mu..m) when the brightness decreases.

Strong paramagnon scattering in single atom Pd contacts

DEFF Research Database (Denmark)

Schendel, V.; Barreteau, Cyrille; Brandbyge, Mads

2017-01-01

Pd contacts shows a reduction with increasing bias, which gives rise to a peculiar Lambda-shaped spectrum. Supported by theoretical calculations, we correlate this finding with the lifetime of hot quasiparticles in Pd, which is strongly influenced by paramagnon scattering. In contrast to this, Co...

Toward a new polyethylene scattering law determined using inelastic neutron scattering

International Nuclear Information System (INIS)

Lavelle, C.M.; Liu, C.-Y.; Stone, M.B.

2013-01-01

Monte Carlo neutron transport codes such as MCNP rely on accurate data for nuclear physics cross-sections to produce accurate results. At low energy, this takes the form of scattering laws based on the dynamic structure factor, S(Q,E). High density polyethylene (HDPE) is frequently employed as a neutron moderator at both high and low temperatures, however the only cross-sections available are for ambient temperatures (∼300K), and the evaluation has not been updated in quite some time. In this paper we describe inelastic neutron scattering measurements on HDPE at 5 and 294 K which are used to improve the scattering law for HDPE. We review some of the past HDPE scattering laws, describe the experimental methods, and compare computations using these models to the measured S(Q,E). The total cross-section is compared to available data, and the treatment of the carbon secondary scatterer as a free gas is assessed. We also discuss the use of the measurement itself as a scattering law via the one phonon approximation. We show that a scattering law computed using a more detailed model for the Generalized Density of States (GDOS) compares more favorably to this experiment, suggesting that inelastic neutron scattering can play an important role in both the development and validation of new scattering laws for Monte Carlo work. -- Highlights: ► Polyethylene at 5 K and 300 K is measured using inelastic neutron scattering (INS). ► Measurements conducted at the Wide Angular-Range Chopper Spectrometer at SNS. ► Several models for Polyethylene are compared to measurements. ► Improvements to existing models for the polyethylene scattering law are suggested. ► INS is shown to be highly valuable tool for scattering law development

Hole mobility and remote scattering in strained InGaSb quantum well MOSFET channels with Al{sub 2}O{sub 3} oxide

Energy Technology Data Exchange (ETDEWEB)

Kumar Madisetti, Shailesh; Chidambaram, Thenappan; Nagaiah, Padmaja; Tokranov, Vadim; Yakimov, Michael; Oktyabrsky, Serge [College of Nanoscale Science and Engineering, University at Albany - SUNY, 257 Fuller Road, Albany, NY 12203 (United States)

2013-08-15

Hall mobility and major scattering mechanisms in surface and buried MBE grown strained InGaSb quantum well (QW) MOSFET channels with in-situ grown Al{sub 2}O{sub 3} gate oxide are analyzed as a function of sheet hole density, top-barrier thickness and temperature. Mobility dependence on Al{sub 0.8}Ga{sub 0.2}Sb top-barrier thickness shows that the relative contribution of interface-related scattering is as low as {proportional_to}30% in the surface QW channel. An InAs top capping layer reduces the interface scattering even further; the sample with 3 nm total top-barrier thickness demonstrates mobility of 980 cm{sup 2}/Vs giving sheet resistance of 4.3 k{Omega}/sq, very close to the minimum QW resistance in the bulk. The mobility-temperature dependences indicate that the interface-related scattering is dominated by remote Coulomb scattering at hole densities <1 x 10{sup 12} cm{sup -2}. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Scattering and multiple scattering in disordered materials

International Nuclear Information System (INIS)

Weaver, R.L.; Butler, W.H.

1992-01-01

The papers in this section were presented at a joint session of symposium V on Applications of Multiple Scattering Theory and of Symposium P on Disordered Systems. They show that the ideas of scattering theory can help us to understand a very broad class of phenomena

Modeling single-scattering properties of small cirrus particles by use of a size-shape distribution of ice spheroids and cylinders

International Nuclear Information System (INIS)

Liu Li; Mishchenko, Michael I.; Cairns, Brian; Carlson, Barbara E.; Travis, Larry D.

2006-01-01

In this study, we model single-scattering properties of small cirrus crystals using mixtures of polydisperse, randomly oriented spheroids and cylinders with varying aspect ratios and with a refractive index representative of water ice at a wavelength of 1.88 μm. The Stokes scattering matrix elements averaged over wide shape distributions of spheroids and cylinders are compared with those computed for polydisperse surface-equivalent spheres. The shape-averaged phase function for a mixture of oblate and prolate spheroids is smooth, featureless, and nearly flat at side-scattering angles and closely resembles those typically measured for cirrus. Compared with the ensemble-averaged phase function for spheroids, that for a shape distribution of cylinders shows a relatively deeper minimum at side-scattering angles. This may indicate that light scattering from realistic cirrus crystals can be better represented by a shape mixture of ice spheroids. Interestingly, the single-scattering properties of shape-averaged oblate and prolate cylinders are very similar to those of compact cylinders with a diameter-to-length ratio of unity. The differences in the optical cross sections, single-scattering albedo, and asymmetry parameter between the spherical and the nonspherical particles studied appear to be relatively small. This may suggest that for a given optical thickness, the influence of particle shape on the radiative forcing caused by a cloud composed of small ice crystals can be negligible

30 CFR 77.1431 - Minimum rope strength.

Science.gov (United States)

2010-07-01

... feet: Minimum Value=Static Load×(7.0−0.001L) For rope lengths 3,000 feet or greater: Minimum Value=Static Load×4.0 (b) Friction drum ropes. For rope lengths less than 4,000 feet: Minimum Value=Static Load×(7.0−0.0005L) For rope lengths 4,000 feet or greater: Minimum Value=Static Load×5.0 (c) Tail ropes...

Fast scattering simulation tool for multi-energy x-ray imaging

Energy Technology Data Exchange (ETDEWEB)

Sossin, A., E-mail: artur.sossin@cea.fr [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Tabary, J.; Rebuffel, V. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Létang, J.M.; Freud, N. [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard (France); Verger, L. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France)

2015-12-01

A combination of Monte Carlo (MC) and deterministic approaches was employed as a means of creating a simulation tool capable of providing energy resolved x-ray primary and scatter images within a reasonable time interval. Libraries of Sindbad, a previously developed x-ray simulation software, were used in the development. The scatter simulation capabilities of the tool were validated through simulation with the aid of GATE and through experimentation by using a spectrometric CdTe detector. A simple cylindrical phantom with cavities and an aluminum insert was used. Cross-validation with GATE showed good agreement with a global spatial error of 1.5% and a maximum scatter spectrum error of around 6%. Experimental validation also supported the accuracy of the simulations obtained from the developed software with a global spatial error of 1.8% and a maximum error of around 8.5% in the scatter spectra.

A Phosphate Minimum in the Oxygen Minimum Zone (OMZ) off Peru

Science.gov (United States)

Paulmier, A.; Giraud, M.; Sudre, J.; Jonca, J.; Leon, V.; Moron, O.; Dewitte, B.; Lavik, G.; Grasse, P.; Frank, M.; Stramma, L.; Garcon, V.

2016-02-01

The Oxygen Minimum Zone (OMZ) off Peru is known to be associated with the advection of Equatorial SubSurface Waters (ESSW), rich in nutrients and poor in oxygen, through the Peru-Chile UnderCurrent (PCUC), but this circulation remains to be refined within the OMZ. During the Pelágico cruise in November-December 2010, measurements of phosphate revealed the presence of a phosphate minimum (Pmin) in various hydrographic stations, which could not be explained so far and could be associated with a specific water mass. This Pmin, localized at a relatively constant layer ( 20minimum with a mean vertical phosphate decrease of 0.6 µM but highly variable between 0.1 and 2.2 µM. In average, these Pmin are associated with a predominant mixing of SubTropical Under- and Surface Waters (STUW and STSW: 20 and 40%, respectively) within ESSW ( 25%), complemented evenly by overlying (ESW, TSW: 8%) and underlying waters (AAIW, SPDW: 7%). The hypotheses and mechanisms leading to the Pmin formation in the OMZ are further explored and discussed, considering the physical regional contribution associated with various circulation pathways ventilating the OMZ and the local biogeochemical contribution including the potential diazotrophic activity.

Diffractive scattering on nuclei in multiple scattering theory with inelastic screening

International Nuclear Information System (INIS)

Zoller, V.R.

1988-01-01

The cross sections for the diffractive scattering of hadrons on nuclei are calculated in the two-channel approximation of multiple scattering theory. In contrast to the standard Glauber approach, it is not assumed that the nucleon scattering profile is a Gaussian or that the Regge radius of the hadron is small compared to the nuclear radius. The AGK Reggeon diagrammatic technique is used to calculate the topological cross sections and the cross sections for coherent and incoherent diffractive dissociation and quasielastic scattering. The features of hadron-nucleus scattering at superhigh energies are discussed

Compton-scatter tissue densitometry: calculation of single and multiple scatter photon fluences

International Nuclear Information System (INIS)

Battista, J.J.; Bronskill, M.J.

1978-01-01

The accurate measurement of in vivo electron densities by the Compton-scatter method is limited by attenuations and multiple scattering in the patient. Using analytic and Monte Carlo calculation methods, the Clarke tissue density scanner has been modelled for incident monoenergetic photon energies from 300 to 2000 keV and for mean scattering angles of 30 to 130 degrees. For a single detector focussed to a central position in a uniform water phantom (25 x 25 x 25 cm 3 ) it has been demonstrated that: (1) Multiple scatter contamination is an inherent limitation of the Compton-scatter method of densitometry which can be minimised, but not eliminated, by improving the energy resolution of the scattered radiation detector. (2) The choice of the incident photon energy is a compromise between the permissible radiation dose to the patient and the tolerable level of multiple scatter contamination. For a mean scattering angle of 40 degrees, the intrinsic multiple-single scatter ratio decreases from 64 to 35%, and the radiation dose (per measurement) increases from 1.0 to 4.1 rad, as the incident photon energy increases from 300 to 2000 keV. These doses apply to a sampled volume of approximately 0.3 cm 3 and an electron density precision of 0.5%. (3) The forward scatter densitometer configuration is optimum, minimising both the dose and the multiple scatter contamination. For an incident photon energy of 1250 keV, the intrinsic multiple-single scatter ratio reduces from 122 to 27%, and the dose reduces from 14.3 to 1.2 rad, as the mean scattering angle decreases from 130 to 30 degrees. These calculations have been confirmed by experimental measurements. (author)

Scatter radiation in digital tomosynthesis of the breast

International Nuclear Information System (INIS)

Sechopoulos, Ioannis; Suryanarayanan, Sankararaman; Vedantham, Srinivasan; D'Orsi, Carl J.; Karellas, Andrew

2007-01-01

effect on the scatter PSF and on the SPR. Glandular fraction and compressed breast size were found to have a small effect, while compressed breast thickness and projection angle, as expected, introduced large variations in both the scatter PSF and SPR. The presence of the breast support plate and the detector cover plate in the simulations introduced important effects on the SPR, which are also relevant to the scatter content in planar mammography

Neutron Scattering Software

Science.gov (United States)

Home Page | Facilities | Reference | Software | Conferences | Announcements | Mailing Lists Neutron Scattering Banner Neutron Scattering Software A new portal for neutron scattering has just been established sets KUPLOT: data plotting and fitting software ILL/TAS: Matlab probrams for analyzing triple axis data

Measurement of proton inelastic scattering cross sections on fluorine

Energy Technology Data Exchange (ETDEWEB)

Chiari, M., E-mail: chiari@fi.infn.it [Department of Physics and Astronomy, University of Florence and INFN Florence, Sesto Fiorentino (Italy); Caciolli, A. [Department of Physics and Astronomy, University of Padua and INFN Padua, Padova (Italy); Calzolai, G. [Department of Physics and Astronomy, University of Florence and INFN Florence, Sesto Fiorentino (Italy); Climent-Font, A. [CMAM, Universidad Autonoma de Madrid, Madrid (Spain); Lucarelli, F.; Nava, S. [Department of Physics and Astronomy, University of Florence and INFN Florence, Sesto Fiorentino (Italy)

2016-10-01

Differential cross-sections for proton inelastic scattering on fluorine, {sup 19}F(p,p’){sup 19}F, from the first five excited levels of {sup 19}F at 110, 197, 1346, 1459 and 1554 keV were measured for beam energies from 3 to 7 MeV at a scattering angle of 150° using a LiF thin target (50 μg/cm{sup 2}) evaporated on a self-supporting C thin film (30 μg/cm{sup 2}). Absolute differential cross-sections were calculated with a method not dependent on the absolute values of collected beam charge and detector solid angle. The validity of the measured inelastic scattering cross sections was then tested by successfully reproducing EBS spectra collected from a thick Teflon (CF{sub 2}) target. As a practical application of these measured inelastic scattering cross sections in elastic backscattering spectroscopy (EBS), the feasibility of quantitative light element (C, N and O) analysis in aerosol particulate matter samples collected on Teflon by EBS measurements and spectra simulation is demonstrated.

Resonant proton scattering of $^{22}$Mg and $^{21}$Na

CERN Multimedia

Di julio, D D; Jansson, K; Rudolph, D; Fynbo, H O U; Nilsson, T; Perea martinez, A

In our letter-of-intent, INTC-I-051, we discussed the physics case for scattering and transfer reactions involving light nuclei in the break-out region of the rp-process. The Committee found the physics case compelling and supported the letter-of-intent under the premise that beams of proper quality were developed and that an adequate detector set-up was presented. As these two requirements have been met recently we now propose to study resonant proton scattering of $^{22}$Mg to identify the states at 1.733 MeV and 2.575 MeV in $^{23}$Al that have been reported from the $^{24}$Mg($^{7}$Li,$^{8}$He)$\\,^{23}\\!$Al reaction but that remained unobserved in the only resonant proton scattering experiment performed with $^{22}$Mg so far. In particular we should be able to investigate the character of the proton emission of the 2.575 MeV state which may also have a significant inelastic branch. We also propose to perform resonant proton scattering on $^{21}$Na above $\\alpha$-particle threshold with $^{18}$Ne to study ...

Energy and intensity distributions of 0.279 MeV multiply Compton-scattered photons in soldering material

International Nuclear Information System (INIS)

Singh, Manpreet; Singh, Gurvinderjit; Singh, Bhajan; Sandhu, B.S.

2007-01-01

An inverse response matrix converts the observed pulse-height distribution of a NaI(Tl) scintillation detector to a photon spectrum. This also results in extraction of intensity distribution of multiply scattered events originating from interactions of 0.279 MeV photons with thick targets of soldering material. The observed pulse-height distributions are a composite of singly and multiply scattered events in addition to bremmstrahlung-and Rayleigh-scattered events. To evaluate the contribution of multiply scattered events, the spectrum of singly scattered events contributing to inelastic Compton peak is reconstructed analytically. The optimum thickness (saturation depth), at which the number of multiply scattered events saturates, has been measured. Monte Carlo calculations also support the present results

Primary and secondary contributions to aerosol light scattering and absorption in Mexico City during the MILAGRO 2006 campaign

Directory of Open Access Journals (Sweden)

G. Paredes-Miranda

2009-06-01

Full Text Available A photoacoustic spectrometer, a nephelometer, an aethalometer, and an aerosol mass spectrometer were used to measure at ground level real-time aerosol light absorption, scattering, and chemistry at an urban site located in North East Mexico City (Instituto Mexicano del Petroleo, Mexican Petroleum Institute, denoted by IMP, as part of the Megacity Impact on Regional and Global Environments field experiment, MILAGRO, in March 2006. Photoacoustic and reciprocal nephelometer measurements at 532 nm accomplished with a single instrument compare favorably with conventional measurements made with an aethalometer and a TSI nephelometer. The diurnally averaged single scattering albedo at 532 nm was found to vary from 0.60 to 0.85 with the peak value at midday and the minimum value at 07:00 a.m. local time, indicating that the Mexico City plume is likely to have a net warming effect on local climate. The peak value is associated with strong photochemical generation of secondary aerosol. It is estimated that the photochemical production of secondary aerosol (inorganic and organic is approximately 75% of the aerosol mass concentration and light scattering in association with the peak single scattering albedo. A strong correlation of aerosol scattering at 532 nm and total aerosol mass concentration was found, and an average mass scattering efficiency factor of 3.8 m²/g was determined. Comparisons of photoacoustic and aethalometer light absorption with oxygenated organic aerosol concentration (OOA indicate a very small systematic bias of the filter based measurement associated with OOA and the peak aerosol single scattering albedo.

Primary and secondary contributions to aerosol light scattering and absorption in Mexico City during the MILAGRO 2006 campaign

Science.gov (United States)

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

2009-06-01

A photoacoustic spectrometer, a nephelometer, an aethalometer, and an aerosol mass spectrometer were used to measure at ground level real-time aerosol light absorption, scattering, and chemistry at an urban site located in North East Mexico City (Instituto Mexicano del Petroleo, Mexican Petroleum Institute, denoted by IMP), as part of the Megacity Impact on Regional and Global Environments field experiment, MILAGRO, in March 2006. Photoacoustic and reciprocal nephelometer measurements at 532 nm accomplished with a single instrument compare favorably with conventional measurements made with an aethalometer and a TSI nephelometer. The diurnally averaged single scattering albedo at 532 nm was found to vary from 0.60 to 0.85 with the peak value at midday and the minimum value at 07:00 a.m. local time, indicating that the Mexico City plume is likely to have a net warming effect on local climate. The peak value is associated with strong photochemical generation of secondary aerosol. It is estimated that the photochemical production of secondary aerosol (inorganic and organic) is approximately 75% of the aerosol mass concentration and light scattering in association with the peak single scattering albedo. A strong correlation of aerosol scattering at 532 nm and total aerosol mass concentration was found, and an average mass scattering efficiency factor of 3.8 m2/g was determined. Comparisons of photoacoustic and aethalometer light absorption with oxygenated organic aerosol concentration (OOA) indicate a very small systematic bias of the filter based measurement associated with OOA and the peak aerosol single scattering albedo.

Reconstruction formula for a 3-d phaseless inverse scattering problem for the Schrodinger equation

OpenAIRE

Klibanov, Michael V.; Romanov, Vladimir G.

2014-01-01

The inverse scattering problem of the reconstruction of the unknown potential with compact support in the 3-d Schr\\"odinger equation is considered. Only the modulus of the scattering complex valued wave field is known, whereas the phase is unknown. It is shown that the unknown potential can be reconstructed via the inverse Radon transform. Therefore, a long standing problem posed in 1977 by K. Chadan and P.C. Sabatier in their book "Inverse Problems in Quantum Scattering Theory" is solved.

12 CFR 564.4 - Minimum appraisal standards.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Minimum appraisal standards. 564.4 Section 564.4 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY APPRAISALS § 564.4 Minimum appraisal standards. For federally related transactions, all appraisals shall, at a minimum: (a...

The minimum wage in the Czech enterprises

OpenAIRE

Eva Lajtkepová

2010-01-01

Although the statutory minimum wage is not a new category, in the Czech Republic we encounter the definition and regulation of a minimum wage for the first time in the 1990 amendment to Act No. 65/1965 Coll., the Labour Code. The specific amount of the minimum wage and the conditions of its operation were then subsequently determined by government regulation in February 1991. Since that time, the value of minimum wage has been adjusted fifteenth times (the last increase was in January 2007). ...

Minimum Wages and Regional Disparity: An analysis on the evolution of price-adjusted minimum wages and their effects on firm profitability (Japanese)

OpenAIRE

MORIKAWA Masayuki

2013-01-01

This paper, using prefecture level panel data, empirically analyzes 1) the recent evolution of price-adjusted regional minimum wages and 2) the effects of minimum wages on firm profitability. As a result of rapid increases in minimum wages in the metropolitan areas since 2007, the regional disparity of nominal minimum wages has been widening. However, the disparity of price-adjusted minimum wages has been shrinking. According to the analysis of the effects of minimum wages on profitability us...

Applying machine learning methods for characterization of hexagonal prisms from their 2D scattering patterns - an investigation using modelled scattering data

Science.gov (United States)

Salawu, Emmanuel Oluwatobi; Hesse, Evelyn; Stopford, Chris; Davey, Neil; Sun, Yi

2017-11-01

Better understanding and characterization of cloud particles, whose properties and distributions affect climate and weather, are essential for the understanding of present climate and climate change. Since imaging cloud probes have limitations of optical resolution, especially for small particles (with diameter < 25 μm), instruments like the Small Ice Detector (SID) probes, which capture high-resolution spatial light scattering patterns from individual particles down to 1 μm in size, have been developed. In this work, we have proposed a method using Machine Learning techniques to estimate simulated particles' orientation-averaged projected sizes (PAD) and aspect ratio from their 2D scattering patterns. The two-dimensional light scattering patterns (2DLSP) of hexagonal prisms are computed using the Ray Tracing with Diffraction on Facets (RTDF) model. The 2DLSP cover the same angular range as the SID probes. We generated 2DLSP for 162 hexagonal prisms at 133 orientations for each. In a first step, the 2DLSP were transformed into rotation-invariant Zernike moments (ZMs), which are particularly suitable for analyses of pattern symmetry. Then we used ZMs, summed intensities, and root mean square contrast as inputs to the advanced Machine Learning methods. We created one random forests classifier for predicting prism orientation, 133 orientation-specific (OS) support vector classification models for predicting the prism aspect-ratios, 133 OS support vector regression models for estimating prism sizes, and another 133 OS Support Vector Regression (SVR) models for estimating the size PADs. We have achieved a high accuracy of 0.99 in predicting prism aspect ratios, and a low value of normalized mean square error of 0.004 for estimating the particle's size and size PADs.

Contribution of ultrasound forward scattering to tissue structure study

International Nuclear Information System (INIS)

Edee, M.K.

1987-12-01

In this paper, we show how to get useful information of tissue structure by merely interpreting some experimental graphs such as energy spectral density and autocorrelation function of an ultrasonic beam travelling through tissues. To support these interpretations, we needed just some well-known theorems rather than heavy and complicated mathematical equations, so we measured the dimensions of scatterers within specimens by using the graphical representation of autocorrelation function. We related these measurements to the scattered peaks which appear in energy density spectrum. The values we found were equal to those obtained from biologists within ∼ 15%. (author) 26 refs, 6 figs, tabs

41 CFR 50-201.1101 - Minimum wages.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Minimum wages. 50-201... Contracts PUBLIC CONTRACTS, DEPARTMENT OF LABOR 201-GENERAL REGULATIONS § 50-201.1101 Minimum wages. Determinations of prevailing minimum wages or changes therein will be published in the Federal Register by the...

Testing the Feasibility of Using PERM to Apply Scattering-Angle Filtering in the Image-Domain for FWI Applications

KAUST Repository

Alzahrani, Hani Ataiq

2014-09-01

ABSTRACT Testing the Feasibility of Using PERM to Apply Scattering-Angle Filtering in the Image-Domain for FWI Applications Hani Ataiq Alzahrani Full Waveform Inversion (FWI) is a non-linear optimization problem aimed to estimating subsurface parameters by minimizing the mis t between modeled and recorded seismic data using gradient descent methods, which are the only practical choice because of the size of the problem. Due to the high non-linearity of the problem, gradient methods will converge to a local minimum if the starting model is not close to the true one. The accuracy of the long-wavelength components of the initial model controls the level of non-linearity of the inversion. In order for FWI to converge to the global minimum, we have to obtain the long wavelength components of the model before inverting for the short wavelengths. Ultra-low temporal frequencies are sensitive to the smooth (long wavelength) part of the model, and can be utilized by waveform inversion to resolve that part. Un- fortunately, frequencies in this range are normally missing in eld data due to data- acquisition limitations. The lack of low frequencies can be compensated for by uti- lizing wide-aperture data, as they include arrivals that are especially sensitive to the long wavelength components of the model. The higher the scattering angle of a 5 recorded event, the higher the model wavelength it can resolve. Based on this prop- erty, a scattering-angle ltering algorithm is proposed to start the inversion process with events corresponding to the highest scattering angle available in the data, and then include lower scattering angles progressively. The large scattering angles will resolve the smooth part of the model and reduce the non-linearity of the problem, then the lower ones will enhance the resolution of the model. Recorded data is rst migrated using Pre-stack Exploding Re ector Migration (PERM), then the resulting pre-stack image is transformed into angle gathers to which

J-matrix method of scattering in one dimension: The nonrelativistic theory

International Nuclear Information System (INIS)

Alhaidari, A.D.; Bahlouli, H.; Abdelmonem, M.S.

2009-01-01

We formulate a theory of nonrelativistic scattering in one dimension based on the J-matrix method. The scattering potential is assumed to have a finite range such that it is well represented by its matrix elements in a finite subset of a basis that supports a tridiagonal matrix representation for the reference wave operator. Contrary to our expectation, the 1D formulation reveals a rich and highly nontrivial structure compared to the 3D formulation. Examples are given to demonstrate the utility and accuracy of the method. It is hoped that this formulation constitutes a viable alternative to the classical treatment of 1D scattering problem and that it will help unveil new and interesting applications.

Cross plane scattering correction

International Nuclear Information System (INIS)

Shao, L.; Karp, J.S.

1990-01-01

Most previous scattering correction techniques for PET are based on assumptions made for a single transaxial plane and are independent of axial variations. These techniques will incorrectly estimate the scattering fraction for volumetric PET imaging systems since they do not take the cross-plane scattering into account. In this paper, the authors propose a new point source scattering deconvolution method (2-D). The cross-plane scattering is incorporated into the algorithm by modeling a scattering point source function. In the model, the scattering dependence both on axial and transaxial directions is reflected in the exponential fitting parameters and these parameters are directly estimated from a limited number of measured point response functions. The authors' results comparing the standard in-plane point source deconvolution to the authors' cross-plane source deconvolution show that for a small source, the former technique overestimates the scatter fraction in the plane of the source and underestimate the scatter fraction in adjacent planes. In addition, the authors also propose a simple approximation technique for deconvolution

Magnetic photon scattering

International Nuclear Information System (INIS)

Lovesey, S.W.

1987-05-01

The report reviews, at an introductory level, the theory of photon scattering from condensed matter. Magnetic scattering, which arises from first-order relativistic corrections to the Thomson scattering amplitude, is treated in detail and related to the corresponding interaction in the magnetic neutron diffraction amplitude. (author)

Evolution from the coplanar to the perpendicular plane geometry of helium (e,2e) differential cross sections symmetric in scattering angle and energy

International Nuclear Information System (INIS)

Murray, A.J.; Read, F.H.

1993-01-01

Experimentally determined differential cross sections are presented for the (e,2e) process in helium, in which the two outgoing electrons have the same energy and the same scattering angle with respect to the incident beam. At four incident energies from 20 to 50 eV above the ionization threshold the detection plane defined by the outgoing electrons was varied from being coplanar with the incident beam to being perpendicular to the beam. The differential cross section evolves from a two-peak structure in coplanar geometry to a three-peak structure in the perpendicular plane. At the lowest energy the forward-scattering coplanar peak is smaller than the backscatter peak, in contrast to the results at higher energies. A deep minimum is seen at an intermediate plane angle of 67.5 degree, this minimum being deepest at 40 eV above the ionization threshold. The results are normalized to an absolute scale using previous coplanar measurements as discussed in the text. The spectrometer used to collect these results is fully computer controlled and real-time computer optimized

Minimum Wage Laws and the Distribution of Employment.

Science.gov (United States)

Lang, Kevin

The desirability of raising the minimum wage long revolved around just one question: the effect of higher minimum wages on the overall level of employment. An even more critical effect of the minimum wage rests on the composition of employment--who gets the minimum wage job. An examination of employment in eating and drinking establishments…

29 CFR 505.3 - Prevailing minimum compensation.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Prevailing minimum compensation. 505.3 Section 505.3 Labor... HUMANITIES § 505.3 Prevailing minimum compensation. (a)(1) In the absence of an alternative determination...)(2) of this section, the prevailing minimum compensation required to be paid under the Act to the...

Minimum oxygen flow needed for vital support during simulated post-cardiorespiratory arrest resuscitation.

Science.gov (United States)

Sanz-Sanjosé, E; Ariño Irujo, J J; Sánchez Martín, C E; González Perrino, C; López-Timoneda, F

2016-05-01

According to the ERC and the AHA guidelines, FiO2 should be titrated to achieve an O2Sat ≥ 94%. The aim of this study was to determine the minimum oxygen flow and time needed to reach an FiO2 of 0.32 and 0.80 during post-cardiac arrest care. An experimental analysis was performed that consisted of a simulated post-cardiac arrest situation. Different resuscitators were tested and connected to an artificial lung: Mark IV, SPUR II, Revivator Res-Q, O-TWO. The oxygen flow levels tested were 2, 5, 10 and 15 lpm. Bonferroni and Mann-Whitney U tests were used. An FiO2 of 0.32 or more was obtained using any of the oxygen flow and resuscitators. Only the Mark IV achieved an FiO2 of 0.80 after a minimum of 75s ventilating with 2 or 5 lpm. Clinical and statistical differences (P<.05) were found: at 15 lpm it took 35s to reach an FiO2 of 0.80 or more for Mark IV (85.6 [0.3]) and Revivator (84.3 [1.5]) compared to 50s for SPUR II (87.1 [6.4]); at 2 lpm, all of the devices reached an FiO2 of ≥ 0.32 at 30s(Mark IV (34.8 [1.3]), Revivator (35.7 [1.5]) and SPUR II (34.4 [2.1]), except for O-TWO, which took 35s (36.3 [4.3]). Patients could be ventilated with any of the resuscitators using 2 lpm to obtain an FiO2 of 0.32, although possibly O-TWO would be the last option during the first 60s. In order to reach an FiO2 of 0.80, ventilating with 10 lpm should be sufficient, and preferably using Mark IV or Revivator Res-Q. In conclusion, on observing the results of our study, in any possible scenario, it would be advisable to use Revivator Res-Q or Mark IV rather than O-TWO or SPUR II. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Possible role of double scattering in electron-atom scattering in a laser field

International Nuclear Information System (INIS)

Rabadan, I.; Mendez, L.; Dickinson, A.S.

1996-01-01

By considering observations of double-scattering effects in the excitation of the 2 1 P level of He, gas density values estimated for the laser-assisted elastic scattering experiments of Wallbank and Holmes (1993, 1994a,b) for which the Kroll-Watson approximation appears to fail. Using comparable densities for He and lower densities for Ar, and assuming the Kroll-Watson approximation for single-scattering events, differential cross sections are calculated including double scattering for laser-assisted scattering for a range of energies and scattering angles. Comparison with the observed values shows that double-scattering effects can give a semi-quantitative explanation of the apparent breakdown of the Kroll-Watson approximation in both He and Ar. (author)

Minimum DNBR Prediction Using Artificial Intelligence

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Su; Kim, Ju Hyun; Na, Man Gyun [Chosun University, Gwangju (Korea, Republic of)

2011-05-15

The minimum DNBR (MDNBR) for prevention of the boiling crisis and the fuel clad melting is very important factor that should be consistently monitored in safety aspects. Artificial intelligence methods have been extensively and successfully applied to nonlinear function approximation such as the problem in question for predicting DNBR values. In this paper, support vector regression (SVR) model and fuzzy neural network (FNN) model are developed to predict the MDNBR using a number of measured signals from the reactor coolant system. Also, two models are trained using a training data set and verified against test data set, which does not include training data. The proposed MDNBR estimation algorithms were verified by using nuclear and thermal data acquired from many numerical simulations of the Yonggwang Nuclear Power Plant Unit 3 (YGN-3)

Reduction of Raman scattering and fluorescence from anvils in high pressure Raman scattering

Science.gov (United States)

Dierker, S. B.; Aronson, M. C.

2018-05-01

We describe a new design and use of a high pressure anvil cell that significantly reduces the Raman scattering and fluorescence from the anvils in high pressure Raman scattering experiments. The approach is particularly useful in Raman scattering studies of opaque, weakly scattering samples. The effectiveness of the technique is illustrated with measurements of two-magnon Raman scattering in La2CuO4.

FDTD scattered field formulation for scatterers in stratified dispersive media.

Science.gov (United States)

Olkkonen, Juuso

2010-03-01

We introduce a simple scattered field (SF) technique that enables finite difference time domain (FDTD) modeling of light scattering from dispersive objects residing in stratified dispersive media. The introduced SF technique is verified against the total field scattered field (TFSF) technique. As an application example, we study surface plasmon polariton enhanced light transmission through a 100 nm wide slit in a silver film.

Photophoresis and the scattering of electromagnetic radiation

International Nuclear Information System (INIS)

Ipser, J.R.

1985-09-01

Electron-microscope photographs of soot lend support to the picture in which a soot particle is modeled as a collection of chains of small carbon spheres. The soot particle itself is typically considerably larger than the small carbon spheres making up the chains. Thus the soot particles might have a size approx.0.1 - 1 μm while the small carbon spheres might have a size approx.0.03 μm in typical situations. Further, measurements of the density of soot yield values much less than that of normal carbon, indicating that an individual soot particle has a rather small filling factor, i.e., the fraction of the volume of the particle tht is occupied by chains. If a soot particle is taken to be a sphere partially filled with carbon chains, what are its scattering and absorption properties. Several workers have adopted the view that the net scattering and absorption properties can be determined simply by summing the cross-sections for the individual small carbon spheres. We feel that such a procedure cannot be valid in general because it neglects coherence effects among the various randomly located scatterers within the soot particle. It appears that in a first rough approximation the scattering and absorption properties of soot can be determined by estimating the effective dielectric constant of a soot sphere

PREFACE: Atom-surface scattering Atom-surface scattering

Science.gov (United States)

Miret-Artés, Salvador

2010-08-01

It has been a privilege and a real pleasure to organize this special issue or festschrift in the general field of atom-surface scattering (and its interaction) in honor of J R Manson. This is a good opportunity and an ideal place to express our deep gratitude to one of the leaders in this field for his fundamental and outstanding scientific contributions. J R Manson, or Dick to his friends and colleagues, is one of the founding fathers, together with N Cabrera and V Celli, of the 'Theory of surface scattering and detection of surface phonons'. This is the title of the very well-known first theoretical paper by Dick published in Physical Review Letters in 1969. My first meeting with Dick was around twenty years ago in Saclay. J Lapujoulade organized a small group seminar about selective adsorption resonances in metal vicinal surfaces. We discussed this important issue in surface physics and many other things as if we had always known each other. This familiarity and warm welcome struck me from the very beginning. During the coming years, I found this to be a very attractive aspect of his personality. During my stays in Göttingen, we had the opportunity to talk widely about science and life at lunch or dinner time, walking or cycling. During these nice meetings, he showed, with humility, an impressive cultural background. It is quite clear that his personal opinions about history, religion, politics, music, etc, come from considering and analyzing them as 'open dynamical systems'. In particular, with good food and better wine in a restaurant or at home, a happy cheerful soirée is guaranteed with him, or even with only a good beer or espresso, and an interesting conversation arises naturally. He likes to listen before speaking. Probably not many people know his interest in tractors. He has an incredible collection of very old tractors at home. In one of my visits to Clemson, he showed me the collection, explaining to me in great detail, their technical properties

Lax-Phillips scattering theory with two Hilbert spaces V(x)=0((1)/|x|β), β>1

International Nuclear Information System (INIS)

Brambila Paz, F.

1988-10-01

A scattering theory for the wave equation with a perturbation with compact support was developed by Lax and Phillips in 1967. Using Enss approach Phillips developed a Lax-Phillips scattering theory for perturbations V such that V(x)=0((1)/|x| β ), β>2. In this paper we develop a scattering theory for more general perturbations V, i.e. for V(x)=0((1)/|x| β ), β>1. (author). 8 refs

Finite temperature grand canonical ensemble study of the minimum electrophilicity principle.

Science.gov (United States)

Miranda-Quintana, Ramón Alain; Chattaraj, Pratim K; Ayers, Paul W

2017-09-28

We analyze the minimum electrophilicity principle of conceptual density functional theory using the framework of the finite temperature grand canonical ensemble. We provide support for this principle, both for the cases of systems evolving from a non-equilibrium to an equilibrium state and for the change from one equilibrium state to another. In doing so, we clearly delineate the cases where this principle can, or cannot, be used.

Noncommutative Cantor–Bendixson derivatives and scattered C⁎-algebras

Czech Academy of Sciences Publication Activity Database

Ghasemi, Saeed; Koszmider, P.

2018-01-01

Roč. 240, 15 May (2018), s. 183-209 ISSN 0166-8641 Institutional support: RVO:67985840 Keywords : C*-algebras * Cantor-Bendixson derivative * scattered locally compact spaces Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.377, year: 2016 https://www.sciencedirect.com/science/ article /pii/S0166864118301688?via%3Dihub

Noncommutative Cantor–Bendixson derivatives and scattered C⁎-algebras

Czech Academy of Sciences Publication Activity Database

Ghasemi, Saeed; Koszmider, P.

2018-01-01

Roč. 240, 15 May (2018), s. 183-209 ISSN 0166-8641 Institutional support: RVO:67985840 Keywords : C*-algebras * Cantor-Bendixson derivative * scattered locally compact spaces Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 0.377, year: 2016 https://www.sciencedirect.com/science/article/pii/S0166864118301688?via%3Dihub

What is the Minimum EROI that a Sustainable Society Must Have?

Directory of Open Access Journals (Sweden)

David J.R. Murphy

2009-01-01

Full Text Available Economic production and, more generally, most global societies, are overwhelmingly dependant upon depleting supplies of fossil fuels. There is considerable concern amongst resource scientists, if not most economists, as to whether market signals or cost benefit analysis based on today’s prices are sufficient to guide our decisions about our energy future. These suspicions and concerns were escalated during the oil price increase from 2005 – 2008 and the subsequent but probably related market collapse of 2008. We believe that Energy Return On Investment (EROI analysis provides a useful approach for examining disadvantages and advantages of different fuels and also offers the possibility to look into the future in ways that markets seem unable to do. The goal of this paper is to review the application of EROI theory to both natural and economic realms, and to assess preliminarily the minimum EROI that a society must attain from its energy exploitation to support continued economic activity and social function. In doing so we calculate herein a basic first attempt at the minimum EROI for current society and some of the consequences when that minimum is approached. The theory of the minimum EROI discussed here, which describes the somewhat obvious but nonetheless important idea that for any being or system to survive or grow it must gain substantially more energy than it uses in obtaining that energy, may be especially important. Thus any particular being or system must abide by a “Law of Minimum EROI”, which we calculate for both oil and corn-based ethanol as about 3:1 at the mine-mouth/farm-gate. Since most biofuels have EROI’s of less than 3:1 they must be subsidized by fossil fuels to be useful.

Do Some Workers Have Minimum Wage Careers?

Science.gov (United States)

Carrington, William J.; Fallick, Bruce C.

2001-01-01

Most workers who begin their careers in minimum-wage jobs eventually gain more experience and move on to higher paying jobs. However, more than 8% of workers spend at least half of their first 10 working years in minimum wage jobs. Those more likely to have minimum wage careers are less educated, minorities, women with young children, and those…

Does the Minimum Wage Affect Welfare Caseloads?

Science.gov (United States)

Page, Marianne E.; Spetz, Joanne; Millar, Jane

2005-01-01

Although minimum wages are advocated as a policy that will help the poor, few studies have examined their effect on poor families. This paper uses variation in minimum wages across states and over time to estimate the impact of minimum wage legislation on welfare caseloads. We find that the elasticity of the welfare caseload with respect to the…

29 CFR 4.159 - General minimum wage.

Science.gov (United States)

2010-07-01

... 29 Labor 1 2010-07-01 2010-07-01 true General minimum wage. 4.159 Section 4.159 Labor Office of... General minimum wage. The Act, in section 2(b)(1), provides generally that no contractor or subcontractor... a contract less than the minimum wage specified under section 6(a)(1) of the Fair Labor Standards...

Neutron scattering by normal liquids

Energy Technology Data Exchange (ETDEWEB)

Gennes, P.G. de [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

Neutron data on motions in normal liquids well below critical point are reviewed and classified according to the order of magnitude of momentum transfers {Dirac_h}q and energy transfers {Dirac_h}w. For large momentum transfers a perfect gas model is valid. For smaller q and incoherent scattering, the major effects are related to the existence of two characteristic times: the period of oscillation of an atom in its cell, and the average lifetime of the atom in a definite cell. Various interpolation schemes covering both time scales are discussed. For coherent scattering and intermediate q, the energy spread is expected to show a minimum whenever q corresponds to a diffraction peak. For very small q the standard macroscopic description of density fluctuations is applicable. The limits of the various (q) and (w) domains and the validity of various approximations are discussed by a method of moments. The possibility of observing discrete transitions due to internal degrees of freedom in polyatomic molecules, in spite of the 'Doppler width' caused by translational motions, is also examined. (author) [French] L'auteur examine les donnees neutroniques sur les mouvements dans les liquides normaux, bien au-dessous du point critique, et les classe d'apres l'ordre de grandeur des transferts de quantite de mouvement {Dirac_h}q et des transferts d'energie {Dirac_h}w. Pour les grands transferts de, quantite de mouvement, un modele de gaz parfait est valable. En ce qui concerne les faibles valeurs de q et la diffussion incoherente, les principaux effets sont lies a l'existence de deux temps caracteristiques: la periode d'oscillation d'un atome dans sa cellule et la duree moyenne de vie de l'atome dans une cellule determinee. L'auteur etudie divers systemes d'interpolation se rapportant aux deux echelles de temps. Pour la diffusion coherente et les valeurs intermediaires de q, on presume que le spectre d'energie accuse un minimum chaque fois que q correspond a un pic de

Neutron-proton scattering

International Nuclear Information System (INIS)

Doll, P.

1990-02-01

Neutron-proton scattering as fundamental interaction process below and above hundred MeV is discussed. Quark model inspired interactions and phenomenological potential models are described. The seminar also indicates the experimental improvements for achieving new precise scattering data. Concluding remarks indicate the relevance of nucleon-nucleon scattering results to finite nuclei. (orig.) [de

Scattering theory

International Nuclear Information System (INIS)

Sitenko, A.

1991-01-01

This book emerged out of graduate lectures given by the author at the University of Kiev and is intended as a graduate text. The fundamentals of non-relativistic quantum scattering theory are covered, including some topics, such as the phase-function formalism, separable potentials, and inverse scattering, which are not always coverded in textbooks on scattering theory. Criticisms of the text are minor, but the reviewer feels an inadequate index is provided and the citing of references in the Russian language is a hindrance in a graduate text

The role of water-vapour photodissociation on the formation of a deep minimum in mesopause ozone

Directory of Open Access Journals (Sweden)

I. M. Vardavas

1998-02-01

Full Text Available A one-dimensional atmospheric photochemical model with an altitude grid of about 1.5 km was used to examine the structure of the global mean vertical ozone profile and its night-time-to-daytime variation in the upper atmosphere. Two distinct ozone layers are predicted, separated by a sharp drop in the ozone concentration near the mesopause. This naturally occurring mesopause ozone deep minimum is primarily produced by the rapid increase in the destruction of water vapour, and hence increase in HOx, at altitudes between 80 and 85 km, a region where water-vapour photodissociation by ultraviolet radiation of the solar Lyman-alpha line is significant, and where the supply of water vapour is maintained by methane oxidation even for very dry conditions at the tropospheric-stratospheric exchange region. The model indicates that the depth of the mesopause ozone minimum is limited by the efficiency with which inactive molecular hydrogen is produced, either by the conversion of atomic hydrogen to molecular hydrogen via one of the reaction channels of H with HO2, or by Lyman-alpha photodissociation of water vapour via the channel that leads to the production of molecular hydrogen. The ozone concentration rapidly recovers above 85 km due to the rapid increase in O produced by the photodissociation of O2 by absorption of ultraviolet solar radiation in the Schumann-Runge bands and continuum. Above 90 km, there is a decrease in ozone due to photolysis as the production of ozone through the three-body recombination of O2 and O becomes slower with decreasing pressure. The model also predicts two peaks in the night-time/daytime ozone ratio, one near 75 km and the other near 110 km, plus a strong peak in the night-time/daytime ratio of OH near 110 km. Recent observational evidence supports the predictions of the model.Key words. Atmospheric composition and structure · Middle atmosphere · Thermosphere · Transmission and scattering of radiation

Small angle X-ray scattering on concentrated hemoglobin solutions

International Nuclear Information System (INIS)

Zinke, M.; Damaschun, G.; Mueller, J.J.; Ruckpaul, K.

1978-01-01

The small-angle X-ray scattering technique was used to determine the intermolecular structure and interaction potentials in oxi-and deoxi-hemoglobin solutions. The pair correlation function obtained by the ZERNICKE-PRINS equation characterizes the intermolecular structure of the hemoglobin molecules. The intermolecular structure is concentration dependent. The hemoglobin molecules have a 'short range order structure' with a range of about 4 molecule diameters at 324 g/l. The potential functions of the hemoglobin-hemoglobin interaction have been determined on the basis of fluid theories. Except for the deoxi-hemoglobin solution having the concentration 370 g/l, the pair interaction consists in a short repulsion and a weak short-range attraction against kT. The potential minimum is between 1.2 - 1.5 nm above the greatest hemoglobin diameter. (author)

Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures

Energy Technology Data Exchange (ETDEWEB)

Addai, Emmanuel Kwasi, E-mail: emmanueladdai41@yahoo.com; Gabel, Dieter; Krause, Ulrich

2016-04-15

Highlights: • Ignition sensitivity of a highly flammable dust decreases upon addition of inert dust. • Minimum ignition temperature of a highly flammable dust increases when inert concentration increase. • Minimum ignition energy of a highly flammable dust increases when inert concentration increase. • The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. - Abstract: The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%.

Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures

International Nuclear Information System (INIS)

Addai, Emmanuel Kwasi; Gabel, Dieter; Krause, Ulrich

2016-01-01

Highlights: • Ignition sensitivity of a highly flammable dust decreases upon addition of inert dust. • Minimum ignition temperature of a highly flammable dust increases when inert concentration increase. • Minimum ignition energy of a highly flammable dust increases when inert concentration increase. • The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. - Abstract: The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%.

Laser light scatter experiments on plasma focus plant

International Nuclear Information System (INIS)

Wenzel, N.

1985-01-01

The plasma focus plant is an experiment on nuclear fusion, which is distinguished by a high neutron yield. Constituting an important method of diagnosis in plasma focussing, the laser light scatter method makes it possible, apart from finding the electron temperature and density, to determine the ion temperature resolved according to time and place and further, to study the occurrence of micro-turbulent effects. Starting from the theoretical basis, this dissertation describes light scatter measurements with ruby lasers on the POSEIDON plasma focus. They are given, together with earlier measurements on the Frascati 1 MJ plant and the Heidelberg 12 KJ plant. The development of the plasma parameters and the occurrence of superthermal light scatter events are discussed in connection with the dynamics of the plasma and the neutron emission characteristics of the individual plants. The results support the view that the thermo-nuclear neutron production at the plasma focus is negligible. Although the importance of micro-turbulent mechanisms in producing neutrons cannot be finally judged, important guidelines are given for the spatial and time relationships with plasma dynamics, plasma parameters and neutron emission. The work concludes with a comparison of all light scatter measurements at the plasma focus described in the literature. (orig.) [de

Increasing the minimum age of marriage program to improve maternal and child health in Indonesia

Science.gov (United States)

Anjarwati

2017-08-01

The objective of the article is to review the importance of understanding the adolescent reproductive health, especially the impact of early marriage to have commitment for health maintenance by increasing the minimum age of marriage. There are countless studies describing the impact of pregnancy at a very young age, the risk that young people must understand to support the program of increasing minimum age of marriage in Indonesia. Increasing the minimum age of marriage is as one of the government programs in improving maternal and child health. It also supports the Indonesian government's program about a thousand days of life. It is required that teens understand the impact of early marriage to prepare for optimal health for future generations. The maternal mortality rate and infant mortality rate in Indonesia is still high because health is not optimal since the early period of pregnancy. These studies reveal that the increased number of early marriages leads to rising divorce rate, maternal mortality rate, and infant mortality and intensifies the risk of cervical cancer. The increase in early marriage is mostly attributed to unwanted pregnancy. It is revealed that early marriage increases the rate of pregnancy at too young an age with the risk of maternal and child health in Indonesia.

Experimental observation of energy dependence of saturation thickness of multiply scattered gamma photons

International Nuclear Information System (INIS)

Singh, Manpreet; Singh, Gurvinderjit; Singh, Bhajan; Sandhu, B.S.

2008-01-01

The gamma photons continue to soften in energy as the number of scatterings increases in the target having finite dimensions both in depth and lateral dimensions. The number of multiply scattered photons increases with an increase in target thickness, and saturates at a particular value of the target thickness known as saturation thickness (depth). The present measurements are carried out to study the energy dependence of saturation thickness of multiply scattered gamma photons from targets of various thicknesses. The scattered photons are detected by a properly shielded NaI(Tl) gamma ray detector placed at 90 deg. to the incident beam. We observe that the saturation thickness increases with increasing incident gamma photon energy. Monte Carlo calculations based upon the package developed by Bauer and Pattison [Compton scattering experiments at the HMI (1981), HMI-B 364, pp. 1-106] support the present experimental results

New Minimum Wage Research: A Symposium.

Science.gov (United States)

Ehrenberg, Ronald G.; And Others

1992-01-01

Includes "Introduction" (Ehrenberg); "Effect of the Minimum Wage [MW] on the Fast-Food Industry" (Katz, Krueger); "Using Regional Variation in Wages to Measure Effects of the Federal MW" (Card); "Do MWs Reduce Employment?" (Card); "Employment Effects of Minimum and Subminimum Wages" (Neumark,…

Spectral statistics and scattering resonances of complex primes arrays

Science.gov (United States)

Wang, Ren; Pinheiro, Felipe A.; Dal Negro, Luca

2018-01-01

We introduce a class of aperiodic arrays of electric dipoles generated from the distribution of prime numbers in complex quadratic fields (Eisenstein and Gaussian primes) as well as quaternion primes (Hurwitz and Lifschitz primes), and study the nature of their scattering resonances using the vectorial Green's matrix method. In these systems we demonstrate several distinctive spectral properties, such as the absence of level repulsion in the strongly scattering regime, critical statistics of level spacings, and the existence of critical modes, which are extended fractal modes with long lifetimes not supported by either random or periodic systems. Moreover, we show that one can predict important physical properties, such as the existence spectral gaps, by analyzing the eigenvalue distribution of the Green's matrix of the arrays in the complex plane. Our results unveil the importance of aperiodic correlations in prime number arrays for the engineering of gapped photonic media that support far richer mode localization and spectral properties compared to usual periodic and random media.

Concentric layered Hermite scatterers

Science.gov (United States)

Astheimer, Jeffrey P.; Parker, Kevin J.

2018-05-01

The long wavelength limit of scattering from spheres has a rich history in optics, electromagnetics, and acoustics. Recently it was shown that a common integral kernel pertains to formulations of weak spherical scatterers in both acoustics and electromagnetic regimes. Furthermore, the relationship between backscattered amplitude and wavenumber k was shown to follow power laws higher than the Rayleigh scattering k2 power law, when the inhomogeneity had a material composition that conformed to a Gaussian weighted Hermite polynomial. Although this class of scatterers, called Hermite scatterers, are plausible, it may be simpler to manufacture scatterers with a core surrounded by one or more layers. In this case the inhomogeneous material property conforms to a piecewise continuous constant function. We demonstrate that the necessary and sufficient conditions for supra-Rayleigh scattering power laws in this case can be stated simply by considering moments of the inhomogeneous function and its spatial transform. This development opens an additional path for construction of, and use of scatterers with unique power law behavior.

Teaching the Minimum Wage in Econ 101 in Light of the New Economics of the Minimum Wage.

Science.gov (United States)

Krueger, Alan B.

2001-01-01

Argues that the recent controversy over the effect of the minimum wage on employment offers an opportunity for teaching introductory economics. Examines eight textbooks to determine topic coverage but finds little consensus. Describes how minimum wage effects should be taught. (RLH)

SCATTER

International Nuclear Information System (INIS)

Broome, J.

1965-11-01

The programme SCATTER is a KDF9 programme in the Egtran dialect of Fortran to generate normalized angular distributions for elastically scattered neutrons from data input as the coefficients of a Legendre polynomial series, or from differential cross-section data. Also, differential cross-section data may be analysed to produce Legendre polynomial coefficients. Output on cards punched in the format of the U.K. A. E. A. Nuclear Data Library is optional. (author)

Nonlinear Scattering of VLF Waves in the Radiation Belts

Science.gov (United States)

Crabtree, Chris; Rudakov, Leonid; Ganguli, Guru; Mithaiwala, Manish

2014-10-01

Electromagnetic VLF waves, such as whistler mode waves, control the lifetime of trapped electrons in the radiation belts by pitch-angle scattering. Since the pitch-angle scattering rate is a strong function of the wave properties, a solid understanding of VLF wave sources and propagation in the magnetosphere is critical to accurately calculate electron lifetimes. Nonlinear scattering (Nonlinear Landau Damping) is a mechanism that can strongly alter VLF wave propagation [Ganguli et al. 2010], primarily by altering the direction of propagation, and has not been accounted for in previous models of radiation belt dynamics. Laboratory results have confirmed the dramatic change in propagation direction when the pump wave has sufficient amplitude to exceed the nonlinear threshold [Tejero et al. 2014]. Recent results show that the threshold for nonlinear scattering can often be met by naturally occurring VLF waves in the magnetosphere, with wave magnetic fields of the order of 50-100 pT inside the plasmapause. Nonlinear scattering can then dramatically alter the macroscopic dynamics of waves in the radiation belts leading to the formation of a long-lasting wave-cavity [Crabtree et al. 2012] and, when amplification is present, a multi-pass amplifier [Ganguli et al. 2012]. By considering these effects, the lifetimes of electrons can be dramatically reduced. This work is supported by the Naval Research Laboratory base program.

High-k Scattering Receiver Mixer Performance for NSTX-U

Science.gov (United States)

Barchfeld, Robert; Riemenschneider, Paul; Domier, Calvin; Luhmann, Neville; Ren, Yang; Kaita, Robert

2016-10-01

The High-k Scattering system detects primarily electron-scale turbulence k θ spectra for studying electron thermal transport in NSTX-U. A 100 mW, 693 GHz probe beam passes through plasma, and scattered power is detected by a 4-pixel quasi optical, mixer array. Remotely controlled receiving optics allows the scattering volume to be located from core to edge with a k θ span of 7 to 40 cm-1. The receiver array features 4 RF diagonal input horns, where the electric field polarization is aligned along the diagonal of a square cross section horn, at 30 mm channel spacing. The local oscillator is provided by a 14.4 GHz source followed by a x48 multiplier chain, giving an intermediate frequency of 1 GHz. The receiver optics receive 4 discreet scattering angles simultaneously, and then focus the signals as 4 parallel signals to their respective horns. A combination of a steerable probe beam, and translating receiver, allows for upward or downward scattering which together can provide information about 2D turbulence wavenumber spectrum. IF signals are digitized and stored for later computer analysis. The performance of the receiver mixers is discussed, along with optical design features to enhance the tuning and performance of the mixers. Work supported in part by U.S. DOE Grant DE-FG02-99ER54518 and DE-AC02-09CH1146.

30 CFR 75.1431 - Minimum rope strength.

Science.gov (United States)

2010-07-01

..., including rotation resistant). For rope lengths less than 3,000 feet: Minimum Value=Static Load×(7.0−0.001L) For rope lengths 3,000 feet or greater: Minimum Value=Static Load×4.0 (b) Friction drum ropes. For rope lengths less than 4,000 feet: Minimum Value=Static Load×(7.0−0.0005L) For rope lengths 4,000 feet...

Detection and mapping of polar stratospheric clouds using limb scattering observations

Directory of Open Access Journals (Sweden)

C. von Savigny

2005-01-01

Full Text Available Satellite-based measurements of Visible/NIR limb-scattered solar radiation are well suited for the detection and mapping of polar stratospheric clouds (PSCs. This publication describes a method to detect PCSs from limb scattering observations with the Scanning Imaging Absorption spectroMeter for Atmospheric CartograpHY (SCIAMACHY on the European Space Agency's Envisat spacecraft. The method is based on a color-index approach and requires a priori knowledge of the stratospheric background aerosol loading in order to avoid false PSC identifications by stratospheric background aerosol. The method is applied to a sample data set including the 2003 PSC season in the Southern Hemisphere. The PSCs are correlated with coincident UKMO model temperature data, and with very few exceptions, the detected PSCs occur at temperatures below 195–198 K. Monthly averaged PSC descent rates are about 1.5 km/month for the −50° S to −75° S latitude range and assume a maximum between August and September with a value of about 2.5 km/month. The main cause of the PSC descent is the slow descent of the lower stratospheric temperature minimum.

DISCUS, Neutron Single to Double Scattering Ratio in Inelastic Scattering Experiment by Monte-Carlo

International Nuclear Information System (INIS)

Johnson, M.W.

1993-01-01

1 - Description of problem or function: DISCUS calculates the ratio of once-scattered to twice-scattered neutrons detected in an inelastic neutron scattering experiment. DISCUS also calculates the flux of once-scattered neutrons that would have been observed if there were no absorption in the sample and if, once scattered, the neutron would emerge without further re-scattering or absorption. Three types of sample geometry are used: an infinite flat plate, a finite flat plate or a finite length cylinder. (The infinite flat plate is included for comparison with other multiple scattering programs.) The program may be used for any sample for which the scattering law is of the form S(/Q/, omega). 2 - Method of solution: Monte Carlo with importance sampling is used. Neutrons are 'forced' both into useful angular trajectories, and useful energy bins. Biasing of the collision point according to the point of entry of the neutron into the sample is also utilised. The first and second order scattered neutron fluxes are calculated in independent histories. For twice-scattered neutron histories a square distribution in Q-omega space is used to sample the neutron coming from the first scattering event, whilst biasing is used for the second scattering event. (A square distribution is used so as to obtain reasonable inelastic-inelastic statistics.) 3 - Restrictions on the complexity of the problem: Unlimited number of detectors. Max. size of (Q, omega) matrix is 39*149. Max. number of points in momentum space for the scattering cross section is 199

Enhanced Raman scattering on functionalized graphene substrates

Czech Academy of Sciences Publication Activity Database

Valeš, Václav; Kovaříček, Petr; Fridrichová, Michaela; Ji, X.; Ling, X.; Kong, J.; Dresselhaus, M. S.; Kalbáč, Martin

2017-01-01

Roč. 4, č. 2 (2017), č. článku 025087. ISSN 2053-1583 R&D Projects: GA ČR(CZ) GA15-01953S Grant - others:AVČR PPPLZ(CZ) L200401551 Institutional support: RVO:61388955 Keywords : spectroscopy * molecules * graphene * graphene enhanced Raman scattering * functionalized graphene Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 6.937, year: 2016

Some Notes on Neutron Up-Scattering and the Doppler-Broadening of High-Z Scattering Resonances

Energy Technology Data Exchange (ETDEWEB)

Parsons, Donald Kent [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-09-28

When neutrons are scattered by target nuclei at elevated temperatures, it is entirely possible that the neutron will actually gain energy (i.e., up-scatter) from the interaction. This phenomenon is in addition to the more usual case of the neutron losing energy (i.e., down-scatter). Furthermore, the motion of the target nuclei can also cause extended neutron down-scattering, i.e., the neutrons can and do scatter to energies lower than predicted by the simple asymptotic models. In recent years, more attention has been given to temperature-dependent scattering cross sections for materials in neutron multiplying systems. This has led to the inclusion of neutron up-scatter in deterministic codes like Partisn and to free gas scattering models for material temperature effects in Monte Carlo codes like MCNP and cross section processing codes like NJOY. The free gas scattering models have the effect of Doppler Broadening the scattering cross section output spectra in energy and angle. The current state of Doppler-Broadening numerical techniques used at Los Alamos for scattering resonances will be reviewed, and suggestions will be made for further developments. The focus will be on the free gas scattering models currently in use and the development of new models to include high-Z resonance scattering effects. These models change the neutron up-scattering behavior.

Means for supporting nuclear fuel

International Nuclear Information System (INIS)

Cocker, P.; Price, M.A.

1975-01-01

Reference is made to means for supporting nuclear fuel pins in a reactor coolant channel and the problems that arise in this connection. For reasons of nuclear reactivity and neutron economy 'parasitic' material in a reactor core must be kept to a minimum, whilst for heat transfer reasons the use of fuel pins of large cross-sectional areas should be avoided. Fuel pins tend to be long thin objects having a can of minimum thickness and typically a pin may have a length/diameter ratio of about 500/1 and for fast reactor fuel pins, the outside diameter may be about 0.2 inch. The long slender pins must also be spaced very close together. A fast reactor fuel assembly may involve 200 to 300 fuel pins, each a few tenths of an inch in diameter, supported end on to coolant flowing up a channel of about 22 square inches in total area. The pins have a heavy metal oxide filling and require support. Details are given of a suitable method of support. Such support also allows withdrawal of pins from a fuel channel without the risk of breach of the can, after irradiation. (U.K.)

Thomson Scattering

NARCIS (Netherlands)

Donne, A. J. H.

1994-01-01

Thomson scattering is a very powerful diagnostic which is applied at nearly every magnetic confinement device. Depending on the experimental conditions different plasma parameters can be diagnosed. When the wave vector is much larger than the plasma Debye length, the total scattered power is

Polarized Neutron Scattering

OpenAIRE

Roessli, B.; Böni, P.

2000-01-01

The technique of polarized neutron scattering is reviewed with emphasis on applications. Many examples of the usefulness of the method in various fields of physics are given like the determination of spin density maps, measurement of complex magnetic structures with spherical neutron polarimetry, inelastic neutron scattering and separation of coherent and incoherent scattering with help of the generalized XYZ method.

Neutron scattering lengths of molten metals determined by gravity refractometry

Energy Technology Data Exchange (ETDEWEB)

Reiner, G.; Waschkowski, W.; Koester, L. (Technische Univ. Muenchen, Garching (Germany, F.R.). Fakultaet fuer Physik)

1990-10-01

Very accurate values of the coherent neutron scattering lengths of the heavy elements Bi and Pb are important quantities for the investigation of the electric interactions of neutrons with atoms. We performed, therefore, a series of experiments to determine accurate scattering lengths by means of neutron gravity refractometry on liquid mirrors of molten metals. The possible perturbations of the necessary reflection measurements have been discussed in details. After taking into account the uncertainties and corrections associated with observable perturbations we obtained the following values for bound atoms: b(Bi)=8.532{plus minus}0.002 fm, b(Pb)=9.405{plus minus}0.003 fm, b(Tl)=8.776{plus minus}0.005 fm, b(Sn)=6.225{plus minus}0.002 fm and b(Ga)=7.288{plus minus}0.002 fm. These data are corrected for the local field effect occuring in the reflection on liquids. The recently reported results for the neutron's electric polarizability and the neutron-electron scattering length are supported by the Bi- and Pb-scattering length of this work. (orig.).

Neutron scattering lengths of molten metals determined by gravity refractometry

International Nuclear Information System (INIS)

Reiner, G.; Waschkowski, W.; Koester, L.

1990-01-01

Very accurate values of the coherent neutron scattering lengths of the heavy elements Bi and Pb are important quantities for the investigation of the electric interactions of neutrons with atoms. We performed, therefore, a series of experiments to determine accurate scattering lengths by means of neutron gravity refractometry on liquid mirrors of molten metals. The possible perturbations of the necessary reflection measurements have been discussed in details. After taking into account the uncertainties and corrections associated with observable perturbations we obtained the following values for bound atoms: b(Bi)=8.532±0.002 fm, b(Pb)=9.405±0.003 fm, b(Tl)=8.776±0.005 fm, b(Sn)=6.225±0.002 fm and b(Ga)=7.288±0.002 fm. These data are corrected for the local field effect occuring in the reflection on liquids. The recently reported results for the neutron's electric polarizability and the neutron-electron scattering length are supported by the Bi- and Pb-scattering length of this work. (orig.)

Neutron scattering lengths of molten metals determined by gravity refractometry

Energy Technology Data Exchange (ETDEWEB)

Reiner, G; Waschkowski, W; Koester, L [Technische Univ. Muenchen, Garching (Germany, F.R.). Fakultaet fuer Physik

1990-10-01

Very accurate values of the coherent neutron scattering lengths of the heavy elements Bi and Pb are important quantities for the investigation of the electric interactions of neutrons with atoms. We performed, therefore, a series of experiments to determine accurate scattering lengths by means of neutron gravity refractometry on liquid mirrors of molten metals. The possible perturbations of the necessary reflection measurements have been discussed in details. After taking into account the uncertainties and corrections associated with observable perturbations we obtained the following values for bound atoms: b(Bi)=8.532{plus minus}0.002 fm, b(Pb)=9.405{plus minus}0.003 fm, b(Tl)=8.776{plus minus}0.005 fm, b(Sn)=6.225{plus minus}0.002 fm and b(Ga)=7.288{plus minus}0.002 fm. These data are corrected for the local field effect occuring in the reflection on liquids. The recently reported results for the neutron's electric polarizability and the neutron-electron scattering length are supported by the Bi- and Pb-scattering length of this work. (orig.).

Coupling a Federal Minimum Wage Hike with Public Investments to Make Work Pay and Reduce Poverty

Directory of Open Access Journals (Sweden)

Jennifer Romich

2018-02-01

Full Text Available For more than a century, advocates have promoted minimum wage laws to protect workers and their families from poverty. Opponents counter that the policy has, at best, small poverty-reducing effects. We summarize the evidence and describe three factors that might dampen the policy’s effects on poverty: imperfect targeting, heterogeneous labor market effects, and interactions with income support programs. To boost the poverty-reducing effects of the minimum wage, we propose increasing the federal minimum wage to $12 per hour and temporarily expanding an existing employer tax credit. This is a cost-saving proposal because it relies on regulation and creates no new administrative functions. We recommend using those savings to “make work pay” and improve upward mobility for low-income workers through lower marginal tax rates.

Ultrasound scatter in heterogeneous 3D microstructures: Parameters affecting multiple scattering

Science.gov (United States)

Engle, B. J.; Roberts, R. A.; Grandin, R. J.

2018-04-01

This paper reports on a computational study of ultrasound propagation in heterogeneous metal microstructures. Random spatial fluctuations in elastic properties over a range of length scales relative to ultrasound wavelength can give rise to scatter-induced attenuation, backscatter noise, and phase front aberration. It is of interest to quantify the dependence of these phenomena on the microstructure parameters, for the purpose of quantifying deleterious consequences on flaw detectability, and for the purpose of material characterization. Valuable tools for estimation of microstructure parameters (e.g. grain size) through analysis of ultrasound backscatter have been developed based on approximate weak-scattering models. While useful, it is understood that these tools display inherent inaccuracy when multiple scattering phenomena significantly contribute to the measurement. It is the goal of this work to supplement weak scattering model predictions with corrections derived through application of an exact computational scattering model to explicitly prescribed microstructures. The scattering problem is formulated as a volume integral equation (VIE) displaying a convolutional Green-function-derived kernel. The VIE is solved iteratively employing FFT-based con-volution. Realizations of random microstructures are specified on the micron scale using statistical property descriptions (e.g. grain size and orientation distributions), which are then spatially filtered to provide rigorously equivalent scattering media on a length scale relevant to ultrasound propagation. Scattering responses from ensembles of media representations are averaged to obtain mean and variance of quantities such as attenuation and backscatter noise levels, as a function of microstructure descriptors. The computational approach will be summarized, and examples of application will be presented.

Rayleigh scattering in the atmospheres of hot stars

Czech Academy of Sciences Publication Activity Database

Fišák, J.; Krtička, J.; Munzar, D.; Kubát, Jiří

2016-01-01

Roč. 590, June (2016), A95/1-A95/6 ISSN 0004-6361 R&D Projects: GA ČR(CZ) GA14-02385S Grant - others:GA MŠk(CZ) LM2010005 Institutional support: RVO:67985815 Keywords : atomic processes * scattering * stars: chemically peculiar Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.378, year: 2014

Sound Scattering by a Flexible Plate Embedded on Free Surface

Directory of Open Access Journals (Sweden)

Eldad J. Avital

2012-01-01

Full Text Available Sound wave scattering by a flexible plate embedded on water surface is considered. Linear acoustics and plate elasticity are assumed. The aim is to assess the effect of the plate’s flexibility on sound scattering and the potential in using that flexibility for this purpose. A combined sound-structure solution is used, which is based on a Fourier transform of the sound field and a finite-difference numerical-solution of the plate’s dynamics. The solution is implemented for a circular plate subject to a perpendicular incoming monochromatic sound wave. A very good agreement is achieved with a finite-difference solution of the sound field. It is shown that the flexibility of the plate dampens its scattered sound wave regardless of the type of the plate’s edge support. A hole in the plate is shown to further scatter the sound wave to form maxima in the near sound field. It is suggested that applying an external oscillatory pressure on the plate can reduce significantly and even eliminate its scattered wave, thus making the plate close to acoustically invisible. A uniformly distributed external pressure is found capable of achieving that aim as long as the plate is free edged or is not highly acoustically noncompact.

New focus for elastic and diffractive scattering

International Nuclear Information System (INIS)

Kwiecinski, J.

1995-01-01

A regular feature of the international physics calendar is the International Conference on Elastic and Diffractive Scattering, known also as the Blois Workshops, after their 1985 birthplace in France. The content of this year's meeting embraced a broad spectrum of problems ranging from the classical analysis of elastic scattering and total cross-sections to the ''hard'' or deep inelastic phenomena which test the underlying quark-gluon structure of hadrons. These meetings have traditionally concentrated on broad questions of elastic and diffractive scattering, however the shift of emphasis in physics is now reflected at Blois by interest in the wide range of 'soft' hadronic processes which dominate reaction cross-sections. On the traditional side, a substantial part of the conference was devoted to analysis of forward scattering parameters like total cross-sections, real parts etc, using dispersion relations and fundamental asymptotic theorems which bound the possible growth of those parameters with energy. The present experimental situation in this field was summarized by S. Pruss, followed by theoretical presentations by B. Nicolescu, A. Donnachie, T.T. Wu, A. Martin and others. The data for proton-proton and proton-antiproton scattering seem to support dominance of the 'crossing-even' part of the scattering amplitude (which contributes equally to both proton-proton and protonantiproton scattering), with little evidence for a substantial 'odderon' term which contributes with opposite sign in the two cases. The 'pomeron' physics of high energy behaviour was a central feature of the conference. The experimental data seem to suggest that behaviour with increasing energy depends on the magnitude of the scale which characterizes the process - i.e. whether the process is ''soft'' or ''hard''. Hard processes, in general, show a much more rapid increase with increasing

Implementing the correlated fermi gas nuclear model for quasielastic neutrino-nucleus scattering

Science.gov (United States)

Tockstein, Jameson

2017-09-01

When studying neutrino oscillations an understanding of charged current quasielastic (CCQE) neutrino-nucleus scattering is imperative. This interaction depends on a nuclear model as well as knowledge of form factors. Neutrino experiments, such as MiniBooNE, often use the Relativistic Fermi Gas (RFG) nuclear model. Recently, the Correlated Fermi Gas (CFG) nuclear model was suggested in, based on inclusive and exclusive scattering experiments at JLab. We implement the CFG model for CCQE scattering. In particular, we provide analytic expressions for this implementation that can be used to analyze current and future neutrino CCQE data. This project was supported through the Wayne State University REU program under NSF Grant PHY-1460853 and by the DOE Grant DE-SC0007983.

30 CFR 281.30 - Minimum royalty.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Minimum royalty. 281.30 Section 281.30 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF MINERALS OTHER THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF Financial Considerations § 281.30 Minimum royalty...

Robust organelle size extractions from elastic scattering measurements of single cells (Conference Presentation)

Science.gov (United States)

Cannaday, Ashley E.; Draham, Robert; Berger, Andrew J.

2016-04-01

The goal of this project is to estimate non-nuclear organelle size distributions in single cells by measuring angular scattering patterns and fitting them with Mie theory. Simulations have indicated that the large relative size distribution of organelles (mean:width≈2) leads to unstable Mie fits unless scattering is collected at polar angles less than 20 degrees. Our optical system has therefore been modified to collect angles down to 10 degrees. Initial validations will be performed on polystyrene bead populations whose size distributions resemble those of cell organelles. Unlike with the narrow bead distributions that are often used for calibration, we expect to see an order-of-magnitude improvement in the stability of the size estimates as the minimum angle decreases from 20 to 10 degrees. Scattering patterns will then be acquired and analyzed from single cells (EMT6 mouse cancer cells), both fixed and live, at multiple time points. Fixed cells, with no changes in organelle sizes over time, will be measured to determine the fluctuation level in estimated size distribution due to measurement imperfections alone. Subsequent measurements on live cells will determine whether there is a higher level of fluctuation that could be attributed to dynamic changes in organelle size. Studies on unperturbed cells are precursors to ones in which the effects of exogenous agents are monitored over time.

Neutron scattering of a floating heavy water bridge

International Nuclear Information System (INIS)

Fuchs, Elmar C; Bitschnau, Brigitte; Woisetschlaeger, Jakob; Maier, Eugen; Beuneu, Brigitte; Teixeira, Jose

2009-01-01

When high voltage is applied to distilled water filled into two beakers close to each other, a water connection forms spontaneously, giving the impression of a floating water bridge (Fuchs et al 2007 J. Phys. D: Appl. Phys. 40 6112-4, 2008 J. Phys. D: Appl. Phys. 41 185502). This phenomenon is of special interest, since it comprises a number of phenomena currently tackled in modern water science. In this work, the first data on neutron scattering of a floating heavy water bridge are presented and possible interpretations are discussed. D 2 O was measured instead of H 2 O because of the very strong incoherent scattering of H. The obtained data support the 'bubble hypothesis' suggested earlier (Fuchs et al 2008).

State cigarette minimum price laws - United States, 2009.

Science.gov (United States)

2010-04-09

Cigarette price increases reduce the demand for cigarettes and thereby reduce smoking prevalence, cigarette consumption, and youth initiation of smoking. Excise tax increases are the most effective government intervention to increase the price of cigarettes, but cigarette manufacturers use trade discounts, coupons, and other promotions to counteract the effects of these tax increases and appeal to price-sensitive smokers. State cigarette minimum price laws, initiated by states in the 1940s and 1950s to protect tobacco retailers from predatory business practices, typically require a minimum percentage markup to be added to the wholesale and/or retail price. If a statute prohibits trade discounts from the minimum price calculation, these laws have the potential to counteract discounting by cigarette manufacturers. To assess the status of cigarette minimum price laws in the United States, CDC surveyed state statutes and identified those states with minimum price laws in effect as of December 31, 2009. This report summarizes the results of that survey, which determined that 25 states had minimum price laws for cigarettes (median wholesale markup: 4.00%; median retail markup: 8.00%), and seven of those states also expressly prohibited the use of trade discounts in the minimum retail price calculation. Minimum price laws can help prevent trade discounting from eroding the positive effects of state excise tax increases and higher cigarette prices on public health.

Update on the direct n-n scattering experiment at the reactor YAGUAR

Science.gov (United States)

Stephenson, S. L.; Crawford, B. E.; Furman, W. I.; Lychagin, E. V.; Muzichka, A. Yu.; Nekhaev, G. V.; Sharapov, E. I.; Shvetsov, V. N.; Strelkov, A. V.; Levakov, B. G.; Lyzhin, A. E.; Chernukhin, Yu. I.; Howell, C. R.; Mitchell, G. E.; Tornow, W.; Showalter-Bucher, R. A.

2013-10-01

The first direct measurement of the 1S0 neutron-neutron scattering experiment using the YAGUAR aperiodic reactor at the Russian Federal Nuclear Center - All Russian Research Institute of Technical Physics has preliminary results. Thermal neutrons are scattered from a thermal neutron ``gas'' within the scattering chamber of the reactor and measured via time-of-flight. These initial results show an unexpectedly large thermal neutron background now understood to be from radiation-induced desorption within the scattering chamber. Analysis of the neutron time-of-flight spectra suggests neutron scattering from H2 and possibly H2O molecules. An experimental value for the desorption yield ηγ of 0.02 molecules/gamma agrees with modeled results. Techniques to reduce the effect of the nonthermal desorption will be presented. This work was supported in part by ISTC project No. 2286, Russia Found. Grant 01-02-17181, the US DOE grants Nos. DE-FG02-97-ER41042 and DE-FG02-97-ER41033, and by the US NSF through Award Nos. 0107263 and 0555652.

Parity violation in polarized electron scattering

International Nuclear Information System (INIS)

Prescott, C.Y.

1980-10-01

The weak forces are responsible for the decay of radioactive nuclei, and it was in these decay processes where parity non-conservation was first observed. Beta decay occurs through emission of e + or e - particles, indicating that the weak force can carry charge of both signs, and it was natural to speculate on the existence of a neutral component of the weak force. Even though weak neutral forces had not been observed it was conjectured that a neutral component of weak decay could exist, and Zel'dovich in 1957 suggested that parity violating effects may be observable in electron scattering and in atomic spectra. More than twenty years have passed since the early conjectures, and a great deal has been learned. Progress in quantum field theory led to the development of the SU(2) x U(1) gauge theory of weak and electromagnetic interactions and provided a renormalizable theory with a minimum of additional assumptions. Gauge theories predicted the existence of a new force, the neutral current interaction. This new interaction was first seen in 1973 in the Gargamelle bubble chamber at CERN. Today the neutral currents are accepted as well established, and it is the details of the neutral current structure that occupy attention. In particular the role that electrons play cannot be tested readily in neutrino beams (recent neutrino-electron scattering experiments are, however, rapidly improving this situation) and therefore interest in electron-hadron neutral current effects has been high. Parity violation is a unique signature of weak currents, and measurements of its size are a particularly important and sensitive means for determining the neutral current structure

Shaping the light for the investigation of depth-extended scattering media

Science.gov (United States)

Osten, W.; Frenner, K.; Pedrini, G.; Singh, A. K.; Schindler, J.; Takeda, M.

2018-02-01

Scattering media are an ongoing challenge for all kind of imaging technologies including coherent and incoherent principles. Inspired by new approaches of computational imaging and supported by the availability of powerful computers, spatial light modulators, light sources and detectors, a variety of new methods ranging from holography to time-of-flight imaging, phase conjugation, phase recovery using iterative algorithms and correlation techniques have been introduced and applied to different types of objects. However, considering the obvious progress in this field, several problems are still matter of investigation and their solution could open new doors for the inspection and application of scattering media as well. In particular, these open questions include the possibility of extending the 2d-approach to the inspection of depth-extended objects, the direct use of a scattering media as a simple tool for imaging of complex objects and the improvement of coherent inspection techniques for the dimensional characterization of incoherently radiating spots embedded in scattering media. In this paper we show our recent findings in coping with these challenges. First we describe how to explore depth-extended objects by means of a scattering media. Afterwards, we extend this approach by implementing a new type of microscope making use of a simple scatter plate as a kind of flat and unconventional imaging lens. Finally, we introduce our shearing interferometer in combination with structured illumination for retrieving the axial position of fluorescent light emitting spots embedded in scattering media.

Length-scale dependent ensemble-averaged conductance of a 1D disordered conductor: Conductance minimum

International Nuclear Information System (INIS)

Tit, N.; Kumar, N.; Pradhan, P.

1993-07-01

Exact numerical calculation of ensemble averaged length-scale dependent conductance for the 1D Anderson model is shown to support an earlier conjecture for a conductance minimum. Numerical results can be understood in terms of the Thouless expression for the conductance and the Wigner level-spacing statistics. (author). 8 refs, 2 figs

Transic time measures in scattering theory

International Nuclear Information System (INIS)

MacMillan, L.W.; Osborn, T.A.

1980-01-01

This paper studies the time evolution of state vectors that are the solutions of the time-dependent Schroedinger equation, characterized by a Hamiltonian h. We employ trace-theorem methods to prove that the transit time of state vectors through a finite space region, Σ, may be used to construct a family in the energy variable, epsilon, of unique, positive, trace-class operators. The matrix elements of these operators, give the transit time of any vector through Σ, It is proved that the trace of these operators, for a fixed energy epsilon, provide a function which simultaneously gives the sum of all orbital transit times through region Σ and represents the state density of all vectors that have support on Σ and energy epsilon. We use the transit-time operators to recover the usual theory of time delay for single-channel scattering systems. In the process we extend the known results on time delay to include scattering by fixed impurities in a periodic medium

Theoretically unprejudiced fits to proton scattering

International Nuclear Information System (INIS)

Kobos, A.M.; Mackintosh, R.S.

1979-01-01

By using a spline interpolation method applied to all components of the proton optical potential we have fitted elastic scattering from 40 Ca and from 16 O at a range of energies. The potentials are highly oscillatory and we have shown that similar oscillations are found when the spline fitting procedure is applied to pseudo-data generated from potentials of known l-dependence. Moreover, we show how to find an l-independent potential equivalent to one that is l-dependent and we find that it is oscillatory and that various characteristic features of empirical spline fit potentials can be explained. Thus, by fitting the data with model indenpendt l-independent potentials we have found support for the contention that the nucleon optical potential should be viewed as being l-dependent. This work may be regarded as an example of the kind of physical information that can be gained by pursuing exact fits to proton elastic scattering data

9 CFR 147.51 - Authorized laboratory minimum requirements.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Authorized laboratory minimum requirements. 147.51 Section 147.51 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE... Authorized Laboratories and Approved Tests § 147.51 Authorized laboratory minimum requirements. These minimum...

BUILDING A NETWORK FOR NEUTRON SCATTERING EDUCATION

International Nuclear Information System (INIS)

Pynn, Roger; Baker, Shenda Mary; Louca, Despo A.; McGreevy, Robert L.; Ekkebus, Allen E.; Kszos, Lynn A.; Anderson, Ian S.

2008-01-01

In a concerted effort supported by the National Science Foundation, the Department of Commerce, and the Department of Energy, the United States is rebuilding its leadership in neutron scattering capability through a significant investment in U.S. neutron scattering user facilities and related instrumentation. These unique facilities provide opportunities in neutron scattering to a broad community of researchers from academic institutions, federal laboratories, and industry. However, neutron scattering is often considered to be a tool for 'experts only' and in order for the U.S. research community to take full advantage of these new and powerful tools, a comprehensive education and outreach program must be developed. The workshop described below is the first step in developing a national program that takes full advantage of modern education methods and leverages the existing educational capacity at universities and national facilities. During March 27-28, 2008, a workshop entitled 'Building a Network for Neutron Scattering Education' was held in Washington, D.C. The goal of the workshop was to define and design a roadmap for a comprehensive neutron scattering education program in the United States. Successful implementation of the roadmap will maximize the national intellectual capital in neutron sciences and will increase the sophistication of research questions addressed by neutron scattering at the nation's forefront facilities. (See Appendix A for the list of attendees, Appendix B for the workshop agenda, Appendix C for a list of references. Appendix D contains the results of a survey given at the workshop; Appendix E contains summaries of the contributed talks.) The workshop brought together U.S. academicians, representatives from neutron sources, scientists who have developed nontraditional educational programs, educational specialists, and managers from government agencies to create a national structure for providing ongoing neutron scattering education. A

BUILDING A NETWORK FOR NEUTRON SCATTERING EDUCATION

Energy Technology Data Exchange (ETDEWEB)

Pynn, Roger [ORNL; Baker, Shenda Mary [ORNL; Louca, Despo A [ORNL; McGreevy, Robert L [ORNL; Ekkebus, Allen E [ORNL; Kszos, Lynn A [ORNL; Anderson, Ian S [ORNL

2008-10-01

In a concerted effort supported by the National Science Foundation, the Department of Commerce, and the Department of Energy, the United States is rebuilding its leadership in neutron scattering capability through a significant investment in U.S. neutron scattering user facilities and related instrumentation. These unique facilities provide opportunities in neutron scattering to a broad community of researchers from academic institutions, federal laboratories, and industry. However, neutron scattering is often considered to be a tool for 'experts only' and in order for the U.S. research community to take full advantage of these new and powerful tools, a comprehensive education and outreach program must be developed. The workshop described below is the first step in developing a national program that takes full advantage of modern education methods and leverages the existing educational capacity at universities and national facilities. During March 27-28, 2008, a workshop entitled 'Building a Network for Neutron Scattering Education' was held in Washington, D.C. The goal of the workshop was to define and design a roadmap for a comprehensive neutron scattering education program in the United States. Successful implementation of the roadmap will maximize the national intellectual capital in neutron sciences and will increase the sophistication of research questions addressed by neutron scattering at the nation's forefront facilities. (See Appendix A for the list of attendees, Appendix B for the workshop agenda, Appendix C for a list of references. Appendix D contains the results of a survey given at the workshop; Appendix E contains summaries of the contributed talks.) The workshop brought together U.S. academicians, representatives from neutron sources, scientists who have developed nontraditional educational programs, educational specialists, and managers from government agencies to create a national structure for providing ongoing neutron

Experimental investigations of the minimum ignition energy and the minimum ignition temperature of inert and combustible dust cloud mixtures.

Science.gov (United States)

Addai, Emmanuel Kwasi; Gabel, Dieter; Krause, Ulrich

2016-04-15

The risks associated with dust explosions still exist in industries that either process or handle combustible dust. This explosion risk could be prevented or mitigated by applying the principle of inherent safety (moderation). This is achieved by adding an inert material to a highly combustible material in order to decrease the ignition sensitivity of the combustible dust. The presented paper deals with the experimental investigation of the influence of adding an inert dust on the minimum ignition energy and the minimum ignition temperature of the combustible/inert dust mixtures. The experimental investigation was done in two laboratory scale equipment: the Hartmann apparatus and the Godbert-Greenwald furnace for the minimum ignition energy and the minimum ignition temperature test respectively. This was achieved by mixing various amounts of three inert materials (magnesium oxide, ammonium sulphate and sand) and six combustible dusts (brown coal, lycopodium, toner, niacin, corn starch and high density polyethylene). Generally, increasing the inert materials concentration increases the minimum ignition energy as well as the minimum ignition temperatures until a threshold is reached where no ignition was obtained. The permissible range for the inert mixture to minimize the ignition risk lies between 60 to 80%. Copyright © 2016 Elsevier B.V. All rights reserved.

Light Scattering at Various Angles

Science.gov (United States)

Latimer, Paul; Pyle, B. E.

1972-01-01

The Mie theory of scattering is used to provide new information on how changes in particle volume, with no change in dry weight, should influence light scattering for various scattering angles and particle sizes. Many biological cells (e.g., algal cells, erythrocytes) and large subcellular structures (e.g., chloroplasts, mitochondria) in suspension undergo this type of reversible volume change, a change which is related to changes in the rates of cellular processes. A previous study examined the effects of such volume changes on total scattering. In this paper scattering at 10° is found to follow total scattering closely, but scattering at 45°, 90°, 135°, and 170° behaves differently. Small volume changes can cause very large observable changes in large angle scattering if the sample particles are uniform in size; however, the natural particle size heterogeneity of most samples would mask this effect. For heterogeneous samples of most particle size ranges, particle shrink-age is found to increase large angle scattering. PMID:4556610

Inelastic Light Scattering Processes

Science.gov (United States)

Fouche, Daniel G.; Chang, Richard K.

1973-01-01

Five different inelastic light scattering processes will be denoted by, ordinary Raman scattering (ORS), resonance Raman scattering (RRS), off-resonance fluorescence (ORF), resonance fluorescence (RF), and broad fluorescence (BF). A distinction between fluorescence (including ORF and RF) and Raman scattering (including ORS and RRS) will be made in terms of the number of intermediate molecular states which contribute significantly to the scattered amplitude, and not in terms of excited state lifetimes or virtual versus real processes. The theory of these processes will be reviewed, including the effects of pressure, laser wavelength, and laser spectral distribution on the scattered intensity. The application of these processes to the remote sensing of atmospheric pollutants will be discussed briefly. It will be pointed out that the poor sensitivity of the ORS technique cannot be increased by going toward resonance without also compromising the advantages it has over the RF technique. Experimental results on inelastic light scattering from I(sub 2) vapor will be presented. As a single longitudinal mode 5145 A argon-ion laser line was tuned away from an I(sub 2) absorption line, the scattering was observed to change from RF to ORF. The basis, of the distinction is the different pressure dependence of the scattered intensity. Nearly three orders of magnitude enhancement of the scattered intensity was measured in going from ORF to RF. Forty-seven overtones were observed and their relative intensities measured. The ORF cross section of I(sub 2) compared to the ORS cross section of N2 was found to be 3 x 10(exp 6), with I(sub 2) at its room temperature vapor pressure.

Scattering with polarized neutrons

International Nuclear Information System (INIS)

Schweizer, J.

2007-01-01

In the history of neutron scattering, it was shown very soon that the use of polarized neutron beams brings much more information than usual scattering with unpolarized neutrons. We shall develop here the different scattering methods that imply polarized neutrons: 1) polarized beams without polarization analysis, the flipping ratio method; 2) polarized beams with a uniaxial polarization analysis; 3) polarized beams with a spherical polarization analysis. For all these scattering methods, we shall give examples of the physical problems which can been solved by these methods, particularly in the field of magnetism: investigation of complex magnetic structures, investigation of spin or magnetization densities in metals, insulators and molecular compounds, separation of magnetic and nuclear scattering, investigation of magnetic properties of liquids and amorphous materials and even, for non magnetic material, separation between coherent and incoherent scattering. (author)

Introductory theory of neutron scattering

International Nuclear Information System (INIS)

Gunn, J.M.F.

1986-12-01

The paper comprises a set of six lecture notes which were delivered to the summer school on 'Neutron Scattering at a pulsed source', Rutherford Laboratory, United Kingdom, 1986. The lectures concern the physical principles of neutron scattering. The topics of the lectures include: diffraction, incoherent inelastic scattering, connection with the Schroedinger equation, magnetic scattering, coherent inelastic scattering, and surfaces and neutron optics. (UK)

Full-potential multiple scattering theory with space-filling cells for bound and continuum states.

Science.gov (United States)

Hatada, Keisuke; Hayakawa, Kuniko; Benfatto, Maurizio; Natoli, Calogero R

2010-05-12

We present a rigorous derivation of a real-space full-potential multiple scattering theory (FP-MST) that is free from the drawbacks that up to now have impaired its development (in particular the need to expand cell shape functions in spherical harmonics and rectangular matrices), valid both for continuum and bound states, under conditions for space partitioning that are not excessively restrictive and easily implemented. In this connection we give a new scheme to generate local basis functions for the truncated potential cells that is simple, fast, efficient, valid for any shape of the cell and reduces to the minimum the number of spherical harmonics in the expansion of the scattering wavefunction. The method also avoids the need for saturating 'internal sums' due to the re-expansion of the spherical Hankel functions around another point in space (usually another cell center). Thus this approach provides a straightforward extension of MST in the muffin-tin (MT) approximation, with only one truncation parameter given by the classical relation l(max) = kR(b), where k is the electron wavevector (either in the excited or ground state of the system under consideration) and R(b) is the radius of the bounding sphere of the scattering cell. Moreover, the scattering path operator of the theory can be found in terms of an absolutely convergent procedure in the l(max) --> ∞ limit. Consequently, this feature provides a firm ground for the use of FP-MST as a viable method for electronic structure calculations and makes possible the computation of x-ray spectroscopies, notably photo-electron diffraction, absorption and anomalous scattering among others, with the ease and versatility of the corresponding MT theory. Some numerical applications of the theory are presented, both for continuum and bound states.

Electron scattering from tetrahydrofuran

International Nuclear Information System (INIS)

Fuss, M C; Sanz, A G; García, G; Muñoz, A; Oller, J C; Blanco, F; Do, T P T; Brunger, M J; Almeida, D; Limão-Vieira, P

2012-01-01

Electron scattering from Tetrahydrofuran (C 4 H 8 O) was investigated over a wide range of energies. Following a mixed experimental and theoretical approach, total scattering, elastic scattering and ionization cross sections as well as electron energy loss distributions were obtained.

Minimum Price Guarantees In a Consumer Search Model

NARCIS (Netherlands)

M.C.W. Janssen (Maarten); A. Parakhonyak (Alexei)

2009-01-01

textabstractThis paper is the first to examine the effect of minimum price guarantees in a sequential search model. Minimum price guarantees are not advertised and only known to consumers when they come to the shop. We show that in such an environment, minimum price guarantees increase the value of

Conditions of Minimum Wage Indexation in Czech and Slovak Legislation in the Context of Business Economics

Directory of Open Access Journals (Sweden)

Pernica Martin

2016-12-01

Full Text Available The aim of the article is to assess – on the basis of a comparison of Czech and Slovak legislation relating to the conditions of the minimum wage indexation – whether it would be appropriate to use certain aspects of Slovak legislation in the Czech legislation and vice versa. When elaborating the article, some logical methods were used. In order to collect data, important employers were addressed in the South-Moravian Region. A carrying method used during the work was a comparison. Analyses were processed using the data of the Czech Statistical Office, the European Statistical Office and the Ministry of Labour and Social Affairs of the Czech Republic. To evaluate the research, the percentage representation of positive and negative responses and Pearson’s Chi-square test were used. The paper presents the results of research whose aim was to get the views of entrepreneurs regarding the minimum wage level and conditions of its indexation. Employers supported the idea of maintaining the institution of the minimum wage. A predominant portion of companies would welcome it if the minimum wage were derived on the basis of an average wage, and the vast majority of companies would welcome the annual indexation of the minimum wage by inflation.

Experimental investigations of multiple scattering of 662 keV gamma photons in elements and binary alloys

International Nuclear Information System (INIS)

Singh, Gurvinderjit; Singh, Manpreet; Sandhu, B.S.; Singh, Bhajan

2008-01-01

The energy, intensity and angular distributions of multiple scattering of 662 keV gamma photons, emerging from targets of pure elements and binary alloys, are observed as a function of target thickness in reflection and transmission geometries. The observed spectra recorded by a properly shielded NaI (Tl) scintillation detector, in addition to singly scattered events, consist of photons scattered more than once for thick targets. To extract the contribution of multiply scattered photons from the measured spectra, a singly scattered distribution is reconstructed analytically. We observe that the numbers of multiply scattered events increase with increase in target thickness, and saturate for a particular thickness called saturation thickness. The saturation thickness decreases with increasing atomic number. The multiple scattering, an interfering background noise in Compton profiles and Compton cross-section measurements, has been successfully used as a new technique to assign the 'effective atomic number' to binary alloys. Monte Carlo calculations support the present experimental results

Competition Between Radial Loss and EMIC Wave Scattering of MeV Electrons During Strong CME-shock Driven Storms

Science.gov (United States)

Hudson, M. K.; Jaynes, A. N.; Li, Z.; Malaspina, D.; Millan, R. M.; Patel, M.; Qin, M.; Shen, X.; Wiltberger, M. J.

2017-12-01

The two strongest storms of Solar Cycle 24, 17 March and 22 June 2015, provide a contrast between magnetospheric response to CME-shocks at equinox and solstice. The 17 March CME-shock initiated storm produced a stronger ring current response with Dst = - 223 nT, while the 22 June CME-shock initiated storm reached a minimum Dst = - 204 nT. The Van Allen Probes ECT instrument measured a dropout in flux for both events which can be characterized by magnetopause loss at higher L values prior to strong recovery1. However, rapid loss is seen at L 3 for the June storm at high energies with maximum drop in the 5.2 MeV channel of the REPT instrument coincident with the observation of EMIC waves in the H+ band by the EMFISIS wave instrument. The rapid time scale of loss can be determined from the 65 minute delay in passage of the Probe A relative to the Probe B spacecraft. The distinct behavior of lower energy electrons at higher L values has been modeled with MHD-test particle simulations, while the rapid loss of higher energy electrons is examined in terms of the minimum resonant energy criterion for EMIC wave scattering, and compared with the timescale for loss due to EMIC wave scattering which has been modeled for other storm events.2 1Baker, D. N., et al. (2016), Highly relativistic radiation belt electron acceleration, transport, and loss: Large solar storm events of March and June 2015, J. Geophys. Res. Space Physics, 121, 6647-6660, doi:10.1002/2016JA022502. 2Li, Z., et al. (2014), Investigation of EMIC wave scattering as the cause for the BARREL 17 January 2013 relativistic electron precipitation event: A quantitative comparison of simulation with observations, Geophys. Res. Lett., 41, 8722-8729, doi:10.1002/2014GL062273.

MAGNETIC NEUTRON SCATTERING

Energy Technology Data Exchange (ETDEWEB)

ZALIZNYAK,I.A.; LEE,S.H.

2004-07-30

Much of our understanding of the atomic-scale magnetic structure and the dynamical properties of solids and liquids was gained from neutron-scattering studies. Elastic and inelastic neutron spectroscopy provided physicists with an unprecedented, detailed access to spin structures, magnetic-excitation spectra, soft-modes and critical dynamics at magnetic-phase transitions, which is unrivaled by other experimental techniques. Because the neutron has no electric charge, it is an ideal weakly interacting and highly penetrating probe of matter's inner structure and dynamics. Unlike techniques using photon electric fields or charged particles (e.g., electrons, muons) that significantly modify the local electronic environment, neutron spectroscopy allows determination of a material's intrinsic, unperturbed physical properties. The method is not sensitive to extraneous charges, electric fields, and the imperfection of surface layers. Because the neutron is a highly penetrating and non-destructive probe, neutron spectroscopy can probe the microscopic properties of bulk materials (not just their surface layers) and study samples embedded in complex environments, such as cryostats, magnets, and pressure cells, which are essential for understanding the physical origins of magnetic phenomena. Neutron scattering is arguably the most powerful and versatile experimental tool for studying the microscopic properties of the magnetic materials. The magnitude of the cross-section of the neutron magnetic scattering is similar to the cross-section of nuclear scattering by short-range nuclear forces, and is large enough to provide measurable scattering by the ordered magnetic structures and electron spin fluctuations. In the half-a-century or so that has passed since neutron beams with sufficient intensity for scattering applications became available with the advent of the nuclear reactors, they have became indispensable tools for studying a variety of important areas of modern

Evaluation of six scatter correction methods based on spectral analysis in 99m Tc SPECT imaging using SIMIND Monte Carlo simulation

Directory of Open Access Journals (Sweden)

Mahsa Noori Asl

2013-01-01

Full Text Available Compton-scattered photons included within the photopeak pulse-height window result in the degradation of SPECT images both qualitatively and quantitatively. The purpose of this study is to evaluate and compare six scatter correction methods based on setting the energy windows in 99m Tc spectrum. SIMIND Monte Carlo simulation is used to generate the projection images from a cold-sphere hot-background phantom. For evaluation of different scatter correction methods, three assessment criteria including image contrast, signal-to-noise ratio (SNR and relative noise of the background (RNB are considered. Except for the dual-photopeak window (DPW method, the image contrast of the five cold spheres is improved in the range of 2.7-26%. Among methods considered, two methods show a nonuniform correction performance. The RNB for all of the scatter correction methods is ranged from minimum 0.03 for DPW method to maximum 0.0727 for the three energy window (TEW method using trapezoidal approximation. The TEW method using triangular approximation because of ease of implementation, good improvement of the image contrast and the SNR for the five cold spheres, and the low noise level is proposed as most appropriate correction method.

Wage inequality, minimum wage effects and spillovers

OpenAIRE

Stewart, Mark B.

2011-01-01

This paper investigates possible spillover effects of the UK minimum wage. The halt in the growth in inequality in the lower half of the wage distribution (as measured by the 50:10 percentile ratio) since the mid-1990s, in contrast to the continued inequality growth in the upper half of the distribution, suggests the possibility of a minimum wage effect and spillover effects on wages above the minimum. This paper analyses individual wage changes, using both a difference-in-differences estimat...

LIGHT SCATTERING BY FRACTAL DUST AGGREGATES. I. ANGULAR DEPENDENCE OF SCATTERING

Energy Technology Data Exchange (ETDEWEB)

Tazaki, Ryo [Department of Astronomy, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Tanaka, Hidekazu [Astronomical Institute, Tohoku University, 6-3 Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Okuzumi, Satoshi; Nomura, Hideko [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Kataoka, Akimasa, E-mail: rtazaki@kusastro.kyoto-u.ac.jp [Institute for Theoretical Astrophysics, Heidelberg University, Albert-Ueberle-Strasse 2, D-69120 Heidelberg (Germany)

2016-06-01

In protoplanetary disks, micron-sized dust grains coagulate to form highly porous dust aggregates. Because the optical properties of these aggregates are not completely understood, it is important to investigate how porous dust aggregates scatter light. In this study, the light scattering properties of porous dust aggregates were calculated using a rigorous method, the T -matrix method, and the results were then compared with those obtained using the Rayleigh–Gans–Debye (RGD) theory and Mie theory with the effective medium approximation (EMT). The RGD theory is applicable to moderately large aggregates made of nearly transparent monomers. This study considered two types of porous dust aggregates—ballistic cluster–cluster agglomerates (BCCAs) and ballistic particle–cluster agglomerates. First, the angular dependence of the scattered intensity was shown to reflect the hierarchical structure of dust aggregates; the large-scale structure of the aggregates is responsible for the intensity at small scattering angles, and their small-scale structure determines the intensity at large scattering angles. Second, it was determined that the EMT underestimates the backward scattering intensity by multiple orders of magnitude, especially in BCCAs, because the EMT averages the structure within the size of the aggregates. It was concluded that the RGD theory is a very useful method for calculating the optical properties of BCCAs.

Diffuse scattering of neutrons

International Nuclear Information System (INIS)

Novion, C.H. de.

1981-02-01

The use of neutron scattering to study atomic disorder in metals and alloys is described. The diffuse elastic scattering of neutrons by a perfect crystal lattice leads to a diffraction spectrum with only Bragg spreads. the existence of disorder in the crystal results in intensity and position modifications to these spreads, and above all, to the appearance of a low intensity scatter between Bragg peaks. The elastic scattering of neutrons is treated in this text, i.e. by measuring the number of scattered neutrons having the same energy as the incident neutrons. Such measurements yield information on the static disorder in the crystal and time average fluctuations in composition and atomic displacements [fr

Gravitational Bhabha scattering

International Nuclear Information System (INIS)

Santos, A F; Khanna, Faqir C

2017-01-01

Gravitoelectromagnetism (GEM) as a theory for gravity has been developed similar to the electromagnetic field theory. A weak field approximation of Einstein theory of relativity is similar to GEM. This theory has been quantized. Traditional Bhabha scattering, electron–positron scattering, is based on quantized electrodynamics theory. Usually the amplitude is written in terms of one photon exchange process. With the development of quantized GEM theory, the scattering amplitude will have an additional component based on an exchange of one graviton at the lowest order of perturbation theory. An analysis will provide the relative importance of the two amplitudes for Bhabha scattering. This will allow an analysis of the relative importance of the two amplitudes as the energy of the exchanged particles increases. (paper)

Minimum Variance Portfolios in the Brazilian Equity Market

Directory of Open Access Journals (Sweden)

Alexandre Rubesam

2013-03-01

Full Text Available We investigate minimum variance portfolios in the Brazilian equity market using different methods to estimate the covariance matrix, from the simple model of using the sample covariance to multivariate GARCH models. We compare the performance of the minimum variance portfolios to those of the following benchmarks: (i the IBOVESPA equity index, (ii an equally-weighted portfolio, (iii the maximum Sharpe ratio portfolio and (iv the maximum growth portfolio. Our results show that the minimum variance portfolio has higher returns with lower risk compared to the benchmarks. We also consider long-short 130/30 minimum variance portfolios and obtain similar results. The minimum variance portfolio invests in relatively few stocks with low βs measured with respect to the IBOVESPA index, being easily replicable by individual and institutional investors alike.

Scattering through a straight quantum waveguide with combined boundary conditions

Czech Academy of Sciences Publication Activity Database

Briet, Ph.; Dittrich, Jaroslav; Soccorsi, E.

2014-01-01

Roč. 55, č. 11 (2014), s. 112104 ISSN 0022-2488 R&D Projects: GA ČR(CZ) GA14-06818S Institutional support: RVO:61389005 Keywords : quantum waveguide * scattering * Dirichlet boundary condition * Neumann boundary condition Subject RIV: BE - Theoretical Physics Impact factor: 1.243, year: 2014

Minimum Covers of Fixed Cardinality in Weighted Graphs.

Science.gov (United States)

White, Lee J.

Reported is the result of research on combinatorial and algorithmic techniques for information processing. A method is discussed for obtaining minimum covers of specified cardinality from a given weighted graph. By the indicated method, it is shown that the family of minimum covers of varying cardinality is related to the minimum spanning tree of…

Activity report on neutron scattering research. V. 1, 1994

International Nuclear Information System (INIS)

Fujii, Y.; Oohara, Y.

1994-09-01

In April, 1993, the Neutron Scattering Laboratory attached to the Institute for Solid State Physics, University of Tokyo, was newly established in Tokai, Ibaraki Prefecture, to promote nationwide users' programs for utilizing the university-owned neutron instruments installed at the JRR-3M reactor of Japan Atomic Energy Research Institute. This upgraded reactor (20 MW, the cold source is installed) has drastically expanded the number of users and research areas since 1990 when it became operational. Currently 8 and 3 out of 18 new spectrometers in total at the JRR-3M are owned by ISSP and Tohoku University, respectively, while the remaining 7 spectrometers belong to JAERI. In addition, 3 conventional spectrometers in the 30 years old JRR-2 reactor (10 MW) have also supported research activities. This is the first issue of 'Activity report on neutron scattering research', and it is to be published annually. In this report, the brief history of neutron scattering research, the users' programs, the committees, the neutron scattering instruments available at the JRR-3M and the JRR-2M, the activity reports on structures and excitation, magnetism, superconductors, liquid and glass, material science, polymers, biology and instrumentation, and publication list are reported. (K.I.)

Who Benefits from a Minimum Wage Increase?

OpenAIRE

John W. Lopresti; Kevin J. Mumford

2015-01-01

This paper addresses the question of how a minimum wage increase affects the wages of low-wage workers. Most studies assume that there is a simple mechanical increase in the wage for workers earning a wage between the old and the new minimum wage, with some studies allowing for spillovers to workers with wages just above this range. Rather than assume that the wages of these workers would have remained constant, this paper estimates how a minimum wage increase impacts a low-wage worker's wage...

N2 production rates limited by nitrite availability in the Bay of Bengal oxygen minimum zone

DEFF Research Database (Denmark)

Bristow, Laura A.; Callbeck, C. M.; Larsen, M

2017-01-01

with isotopically labelled nitrogen compounds and analyse geochemical signatures of these processes in the water column. We find that the Bay of Bengal supports denitrifier and anammox microbial populations, mediating low, but significant N loss. Yet, unlike other oxygen minimum zones, our measurements using...

Economic potential for switchgrass production in the U.S. Northern Plains: A minimum-data analysis

Science.gov (United States)

There is a demand for timely information to support policy decision making. There is also interest in the potential for alternative crops such as switchgrass to be used for ethanol production and which would have a positive impact on net greenhouse gas emission. This paper uses a new minimum-data mo...

Bubble nonlinear dynamics and stimulated scattering process

Science.gov (United States)

Jie, Shi; De-Sen, Yang; Sheng-Guo, Shi; Bo, Hu; Hao-Yang, Zhang; Shi-Yong, Hu

2016-02-01

A complete understanding of the bubble dynamics is deemed necessary in order to achieve their full potential applications in industry and medicine. For this purpose it is first needed to expand our knowledge of a single bubble behavior under different possible conditions including the frequency and pressure variations of the sound field. In addition, stimulated scattering of sound on a bubble is a special effect in sound field, and its characteristics are associated with bubble oscillation mode. A bubble in liquid can be considered as a representative example of nonlinear dynamical system theory with its resonance, and its dynamics characteristics can be described by the Keller-Miksis equation. The nonlinear dynamics of an acoustically excited gas bubble in water is investigated by using theoretical and numerical analysis methods. Our results show its strongly nonlinear behavior with respect to the pressure amplitude and excitation frequency as the control parameters, and give an intuitive insight into stimulated sound scattering on a bubble. It is seen that the stimulated sound scattering is different from common dynamical behaviors, such as bifurcation and chaos, which is the result of the nonlinear resonance of a bubble under the excitation of a high amplitude acoustic sound wave essentially. The numerical analysis results show that the threshold of stimulated sound scattering is smaller than those of bifurcation and chaos in the common condition. Project supported by the Program for Changjiang Scholars and Innovative Research Team in University, China (Grant No. IRT1228) and the Young Scientists Fund of the National Natural Science Foundation of China (Grant Nos. 11204050 and 11204049).

Some results on inverse scattering

International Nuclear Information System (INIS)

Ramm, A.G.

2008-01-01

A review of some of the author's results in the area of inverse scattering is given. The following topics are discussed: (1) Property C and applications, (2) Stable inversion of fixed-energy 3D scattering data and its error estimate, (3) Inverse scattering with 'incomplete' data, (4) Inverse scattering for inhomogeneous Schroedinger equation, (5) Krein's inverse scattering method, (6) Invertibility of the steps in Gel'fand-Levitan, Marchenko, and Krein inversion methods, (7) The Newton-Sabatier and Cox-Thompson procedures are not inversion methods, (8) Resonances: existence, location, perturbation theory, (9) Born inversion as an ill-posed problem, (10) Inverse obstacle scattering with fixed-frequency data, (11) Inverse scattering with data at a fixed energy and a fixed incident direction, (12) Creating materials with a desired refraction coefficient and wave-focusing properties. (author)

The minimum wage in the Czech enterprises

Directory of Open Access Journals (Sweden)

Eva Lajtkepová

2010-01-01

Full Text Available Although the statutory minimum wage is not a new category, in the Czech Republic we encounter the definition and regulation of a minimum wage for the first time in the 1990 amendment to Act No. 65/1965 Coll., the Labour Code. The specific amount of the minimum wage and the conditions of its operation were then subsequently determined by government regulation in February 1991. Since that time, the value of minimum wage has been adjusted fifteenth times (the last increase was in January 2007. The aim of this article is to present selected results of two researches of acceptance of the statutory minimum wage by Czech enterprises. The first research makes use of the data collected by questionnaire research in 83 small and medium-sized enterprises in the South Moravia Region in 2005, the second one the data of 116 enterprises in the entire Czech Republic (in 2007. The data have been processed by means of the standard methods of descriptive statistics and of the appropriate methods of the statistical analyses (Spearman correlation coefficient of sequential correlation, Kendall coefficient, χ2 - independence test, Kruskal-Wallis test, and others.

Quasiresonant scattering

International Nuclear Information System (INIS)

Hategan, Cornel; Comisel, Horia; Ionescu, Remus A.

2004-01-01

The quasiresonant scattering consists from a single channel resonance coupled by direct interaction transitions to some competing reaction channels. A description of quasiresonant Scattering, in terms of generalized reduced K-, R- and S- Matrix, is developed in this work. The quasiresonance's decay width is, due to channels coupling, smaller than the width of the ancestral single channel resonance (resonance's direct compression). (author)

How unprecedented a solar minimum was it?

Science.gov (United States)

Russell, C T; Jian, L K; Luhmann, J G

2013-05-01

The end of the last solar cycle was at least 3 years late, and to date, the new solar cycle has seen mainly weaker activity since the onset of the rising phase toward the new solar maximum. The newspapers now even report when auroras are seen in Norway. This paper is an update of our review paper written during the deepest part of the last solar minimum [1]. We update the records of solar activity and its consequent effects on the interplanetary fields and solar wind density. The arrival of solar minimum allows us to use two techniques that predict sunspot maximum from readings obtained at solar minimum. It is clear that the Sun is still behaving strangely compared to the last few solar minima even though we are well beyond the minimum phase of the cycle 23-24 transition.

Elastic and quasielastic scattering of light nuclei in the theory of multiple scattering

International Nuclear Information System (INIS)

Ismatov, E.I.; Kuterbekov, K.A.; Dzhuraev, Sh.Kh.; Ehsaniyazov, Sh.P.; Zholdasova, S.M.

2005-01-01

In the work the calculation method for diffraction scattering amplitudes of light nuclei by heavy nuclei is developed. For A 1 A 2 -scattering effects of pair-, three-fold, and four-fold screenings are estimated. It is shown, that in amplitude calculations for A 1 A 2 elastic scattering it is enough come to nothing more than accounting of total screenings in the first order. Analysis of nucleus-nucleus scattering sensitive characteristics to choice of single-particle nuclear densities parametrization is carried out

Continuum multiple-scattering approach to electron-molecule scattering and molecular photoionization

International Nuclear Information System (INIS)

Dehmer, J.L.; Dill, D.

1979-01-01

The multiple-scattering approach to the electronic continuum of molecules is described. The continuum multiple-scattering model (CMSM) was developed as a survey tool and, as such was required to satisfy two requirements. First, it had to have a very broad scope, which means (i) molecules of arbitrary geometry and complexity containing any atom in the periodic system, (ii) continuum electron energies from 0-1000 eV, and (iii) capability to treat a large range of processes involving both photoionization and electron scattering. Second, the structure of the theory was required to lend itself to transparent, physical interpretation of major spectral features such as shape resonances. A comprehensive theoretical framework for the continuum multiple scattering method is presented, as well as its applications to electron-molecule scattering and molecular photoionization. Highlights of recent applications in these two areas are reviewed. The major impact of the resulting studies over the last few years has been to establish the importance of shape resonances in electron collisions and photoionization of practically all (non-hydride) molecules

Minimum-Cost Reachability for Priced Timed Automata

DEFF Research Database (Denmark)

Behrmann, Gerd; Fehnker, Ansgar; Hune, Thomas Seidelin

2001-01-01

This paper introduces the model of linearly priced timed automata as an extension of timed automata, with prices on both transitions and locations. For this model we consider the minimum-cost reachability problem: i.e. given a linearly priced timed automaton and a target state, determine...... the minimum cost of executions from the initial state to the target state. This problem generalizes the minimum-time reachability problem for ordinary timed automata. We prove decidability of this problem by offering an algorithmic solution, which is based on a combination of branch-and-bound techniques...

Ocular forward light scattering and corneal backward light scattering in patients with dry eye.

Science.gov (United States)

Koh, Shizuka; Maeda, Naoyuki; Ikeda, Chikako; Asonuma, Sanae; Mitamura, Hayato; Oie, Yoshinori; Soma, Takeshi; Tsujikawa, Motokazu; Kawasaki, Satoshi; Nishida, Kohji

2014-09-18

To evaluate ocular forward light scattering and corneal backward light scattering in patients with dry eye. Thirty-five eyes in 35 patients with dry eye and 20 eyes of 20 healthy control subjects were enrolled. The 35 dry eyes were classified into two groups according to whether superficial punctate keratopathy in the central 6-mm corneal zone (cSPK) was present or not. Ocular forward light scattering was quantified with a straylight meter. Corneal backward light scattering from the anterior, middle, and posterior corneal parts was assessed with a corneal densitometry program using the Scheimpflug imaging system. Both dry eye groups had significantly higher intraocular forward light scattering than the control group (both Pdry eye group with cSPK had significantly higher values in anterior and total corneal backward light scattering than the other two groups. Moderate positive correlations were observed between the cSPK score and corneal backward light scattering from the anterior cornea (R=0.60, Pdry eyes than in normal eyes. Increased corneal backward light scattering in dry eye at least partially results from cSPK overlying the optical zone. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Minimum Q Electrically Small Antennas

DEFF Research Database (Denmark)

Kim, O. S.

2012-01-01

Theoretically, the minimum radiation quality factor Q of an isolated resonance can be achieved in a spherical electrically small antenna by combining TM1m and TE1m spherical modes, provided that the stored energy in the antenna spherical volume is totally suppressed. Using closed-form expressions...... for a multiarm spherical helix antenna confirm the theoretical predictions. For example, a 4-arm spherical helix antenna with a magnetic-coated perfectly electrically conducting core (ka=0.254) exhibits the Q of 0.66 times the Chu lower bound, or 1.25 times the minimum Q....

Protograph based LDPC codes with minimum distance linearly growing with block size

Science.gov (United States)

Divsalar, Dariush; Jones, Christopher; Dolinar, Sam; Thorpe, Jeremy

2005-01-01

We propose several LDPC code constructions that simultaneously achieve good threshold and error floor performance. Minimum distance is shown to grow linearly with block size (similar to regular codes of variable degree at least 3) by considering ensemble average weight enumerators. Our constructions are based on projected graph, or protograph, structures that support high-speed decoder implementations. As with irregular ensembles, our constructions are sensitive to the proportion of degree-2 variable nodes. A code with too few such nodes tends to have an iterative decoding threshold that is far from the capacity threshold. A code with too many such nodes tends to not exhibit a minimum distance that grows linearly in block length. In this paper we also show that precoding can be used to lower the threshold of regular LDPC codes. The decoding thresholds of the proposed codes, which have linearly increasing minimum distance in block size, outperform that of regular LDPC codes. Furthermore, a family of low to high rate codes, with thresholds that adhere closely to their respective channel capacity thresholds, is presented. Simulation results for a few example codes show that the proposed codes have low error floors as well as good threshold SNFt performance.

Stochastic variational approach to minimum uncertainty states

Energy Technology Data Exchange (ETDEWEB)

Illuminati, F.; Viola, L. [Dipartimento di Fisica, Padova Univ. (Italy)

1995-05-21

We introduce a new variational characterization of Gaussian diffusion processes as minimum uncertainty states. We then define a variational method constrained by kinematics of diffusions and Schroedinger dynamics to seek states of local minimum uncertainty for general non-harmonic potentials. (author)

Quantum theory of scattering

CERN Document Server

Wu Ta You

1962-01-01

This volume addresses the broad formal aspects and applications of the quantum theory of scattering in atomic and nuclear collisions. An encyclopedic source of pioneering work, it serves as a text for students and a reference for professionals in the fields of chemistry, physics, and astrophysics. The self-contained treatment begins with the general theory of scattering of a particle by a central field. Subsequent chapters explore particle scattering by a non-central field, collisions between composite particles, the time-dependent theory of scattering, and nuclear reactions. An examinati

Comparative Analysis of Minimum Income Guaranteed Schemes within the Member States of the European Union

Directory of Open Access Journals (Sweden)

Simona Maria Stănescu

2015-09-01

Full Text Available The commitment of the European Union (EU Member States towards accomplishing the commonly agreed goals (1997 European Employment Strategy, Lisbon 2000, and Europe 2020 is supported by a continuous assessment of domestic social policy tendencies. From this perspective, the main goal of the paper is to comparatively analyse the last safety net for the most vulnerable people. The screening of guaranteed minimum resources provides an overview of the applicable statutory basis, schemes in place, types of social benefits concerned, financing and organisation mechanisms, eligibility conditions, duration and time limits. As methodology, the article uses the MISSOC database, and due to the current lack of comparable information, recommendations for further harmonisation are included. 20 of the EU member states follow the minimum income guaranteed (MIG regulations adopted already during the pre-accession period and updated after the accession phase. Seven types of domestic regulations are in force, among which the most frequent ones are acts and laws (ten countries. Common concepts used are social, and assistance. Provided allowances are mainly focused on elderly people, unemployment benefits, pensions, allowances supporting various house related costs, and benefits for disabled people. In line with 2007, 2010, and 2014 data, the financing of guaranteed minimum resources continues to remain mainly central with a shift in 2014 towards mixed financing (both central and local. The management in 2014 continues to be mainly centrally organised but the local stakeholders are also empowered. The residency is the most frequent eligibility condition. No nationality is required in 24 EU member states, for all allowances (21 countries or for particular ones (three countries. 17 member states require no age conditions. Unlimited guaranteed minimum resources were provided in 2014 as long as the eligibility criteria were met in 23 EU member states.

Alignment of the Thomson scattering diagnostic on NSTX

International Nuclear Information System (INIS)

LeBlanc, B P; Diallo, A

2013-01-01

The Thomson scattering diagnostic can provide profile measurement of the electron temperature, T e , and density, n e , in plasmas. Proper laser beam path and optics arrangement permits profiles T e (R) and n e (R) measurement along the major radius R. Keeping proper alignment between the laser beam path and the collection optics is necessary for an accurate determination of the electron density. As time progresses the relative position of the collection optics field of view with respect to the laser beam path will invariably shift. This can be kept to a minimum by proper attention to the physical arrangement of the collection and laser-beam delivery optics. A system has been in place to monitor the relative position between laser beam and collection optics. Variation of the alignment can be detected before it begins to affect the quality of the profile data. This paper discusses details of the instrumentation and techniques used to maintain alignment during NSTX multi-month experimental campaigns

Gravitational scattering of electromagnetic radiation

Science.gov (United States)

Brooker, J. T.; Janis, A. I.

1980-01-01

The scattering of electromagnetic radiation by linearized gravitational fields is studied to second order in a perturbation expansion. The incoming electromagnetic radiation can be of arbitrary multipole structure, and the gravitational fields are also taken to be advanced fields of arbitrary multipole structure. All electromagnetic multipole radiation is found to be scattered by gravitational monopole and time-varying dipole fields. No case has been found, however, in which any electromagnetic multipole radiation is scattered by gravitational fields of quadrupole or higher-order multipole structure. This lack of scattering is established for infinite classes of special cases, and is conjectured to hold in general. The results of the scattering analysis are applied to the case of electromagnetic radiation scattered by a moving mass. It is shown how the mass and velocity may be determined by a knowledge of the incident and scattered radiation.

«Paralipomena» on uniqueness in inverse scattering from a finite number of data

Directory of Open Access Journals (Sweden)

R. Persico

2007-06-01

Full Text Available This paper shows new proof of non-uniqueness of the solution for the retrieving of a compact-supported function starting from a finite number of samples of its spectrum. As will be shown, this is relevant for linear inverse scattering problems, that in many cases can be recast as the reconstruction of a compact supported function from a finite set of samples of its spectrum. Since this reconstruction is not unique, from a practical point of view, any linear inverse scattering algorithm that can be recast in terms of a Fourier relationship between unknowns and data necessarily «trusts» on the absence of invisible objects in the particular situation at hand.

Inelastic scattering in condensed matter with high intensity moessbauer radiation

International Nuclear Information System (INIS)

Yelon, W.B.; Schupp, G.

1991-05-01

We give a progress report for the work which has been carried out in the last three years with DOE support. A facility for high-intensity Moessbauer scattering is not fully operational at the University of Missouri Research Reactor (MURR) as well as a facility at Purdue, using special isotopes produced at MURR. High precision, fundamental Moessbauer effect studies have been carried out using Bragg scattering filters to suppress unwanted radiation. These have led to a Fourier transform method for describing Moessbauer effect (ME) lineshape and a direct method of fitting ME data to the convolution integral. These methods allow complete correction for source resonance self absorption and the accurate representation of interference effects that add an asymmetric component to the ME lines. We have begun applying these techniques to attenuated ME sources whose central peak has been attenuated by stationary resonant absorbers, to make a novel independent determination of interference parameters and line-shape behavior in the resonance asymptotic region. This analysis is important to both fundamental ME studies and to scattering studies for which a deconvolution is essential for extracting the correct recoilless fractions and interference parameters. A number of scattering studies have been successfully carried out including a study of the thermal diffuse scattering in Si, which led to an analysis of the resolution function for gamma-ray scattering. Also studied was the anharmonic motion in Na metal and the charge density wave satellite reflection Debye-Waller factor in TaS 2 , which indicate phason rather than phonon behavior. Using a specially constructed sample cell which enables us to vary temperatures from -10 C to 110 C, we have begun quasielastic diffusion studies in viscous liquids and current results are summarized. Included are the temperature and Q dependence of the scattering in pentadecane and diffusion in glycerol

Medical Physics Practice Guidelines - the AAPM's minimum practice recommendations for medical physicists.

Science.gov (United States)

Mills, Michael D; Chan, Maria F; Prisciandaro, Joann I; Shepard, Jeff; Halvorsen, Per H

2013-11-04

The AAPM has long advocated a consistent level of medical physics practice, and has published many recommendations and position statements toward that goal, such as Science Council Task Group reports related to calibration and quality assurance, Education Council and Professional Council Task Group reports related to education, training, and peer review, and Board-approved Position Statements related to the Scope of Practice, physicist qualifications, and other aspects of medical physics practice. Despite these concerted and enduring efforts, the profession does not have clear and concise statements of the acceptable practice guidelines for routine clinical medical physics. As accreditation of clinical practices becomes more common, Medical Physics Practice Guidelines (MPPGs) will be crucial to ensuring a consistent benchmark for accreditation programs. To this end, the AAPM has recently endorsed the development of MPPGs, which may be generated in collaboration with other professional societies. The MPPGs are intended to be freely available to the general public. Accrediting organizations, regulatory agencies, and legislators will be encouraged to reference these MPPGs when defining their respective requirements. MPPGs are intended to provide the medical community with a clear description of the minimum level of medical physics support that the AAPM would consider prudent in clinical practice settings. Support includes, but is not limited to, staffing, equipment, machine access, and training. These MPPGs are not designed to replace extensive Task Group reports or review articles, but rather to describe the recommended minimum level of medical physics support for specific clinical services. This article has described the purpose, scope, and process for the development of MPPGs.

Diffuse scattering in Ih ice

International Nuclear Information System (INIS)

Wehinger, Björn; Krisch, Michael; Bosak, Alexeï; Chernyshov, Dmitry; Bulat, Sergey; Ezhov, Victor

2014-01-01

Single crystals of ice Ih, extracted from the subglacial Lake Vostok accretion ice layer (3621 m depth) were investigated by means of diffuse x-ray scattering and inelastic x-ray scattering. The diffuse scattering was identified as mainly inelastic and rationalized in the frame of ab initio calculations for the ordered ice XI approximant. Together with Monte-Carlo modelling, our data allowed reconsidering previously available neutron diffuse scattering data of heavy ice as the sum of thermal diffuse scattering and static disorder contribution. (paper)

Scattering of intermediate energy protons

International Nuclear Information System (INIS)

Chaumeaux, Alain.

1980-06-01

The scattering of 1 GeV protons appears to be a powerful means of investigating nuclear matter. We worked with SPESI and the formalism of Kerman-Mc Manus and Thaler. The amplitude of nucleon-nucleon scattering was studied as were the aspects of 1 GeV proton scattering (multiple scattering, absorption, spin-orbit coupling, N-N amplitude, KMT-Glauber comparison, second order effects). The results of proton scattering on 16 O, the isotopes of calcium, 58 Ni, 90 Zr and 208 Pb are given [fr

A GIS-Based Procedure for Landslide Intensity Evaluation and Specific risk Analysis Supported by Persistent Scatterers Interferometry (PSI

Directory of Open Access Journals (Sweden)

Silvia Bianchini

2017-10-01

Full Text Available The evaluation of landslide specific risk, defined as the expected degree of loss due to landslides, requires the parameterization and the combination of a number of socio-economic and geological factors, which often needs the interaction of different skills and expertise (geologists, engineers, planners, administrators, etc.. The specific risk sub-components, i.e., hazard and vulnerability of elements at risk, can be determined with different levels of detail depending on the available auxiliary data and knowledge of the territory. These risk factors are subject to short-term variations and nowadays turn out to be easily mappable and evaluable through remotely sensed data and GIS (Geographic Information System tools. In this work, we propose a qualitative approach at municipal scale for producing a “specific risk” map, supported by recent satellite PSI (Persistent Scatterer Interferometry data derived from SENTINEL-1 C-band images in the spanning time 2014–2017, implemented in a GIS environment. In particular, PSI measurements are useful for the updating of a landslide inventory map of the area of interest and are exploited for the zonation map of the intensity of ground movements, needed for evaluating the vulnerability over the study area. Our procedure is presented throughout the application to the Volterra basin and the output map could be useful to support the local authorities with updated basic information required for environmental knowledge and planning at municipal level. Moreover, the proposed procedure is easily managed and repeatable in other case studies, as well as exploiting different SAR sensors in L- or X-band.

Relevance vector machine technique for the inverse scattering problem

International Nuclear Information System (INIS)

Wang Fang-Fang; Zhang Ye-Rong

2012-01-01

A novel method based on the relevance vector machine (RVM) for the inverse scattering problem is presented in this paper. The nonlinearity and the ill-posedness inherent in this problem are simultaneously considered. The nonlinearity is embodied in the relation between the scattered field and the target property, which can be obtained through the RVM training process. Besides, rather than utilizing regularization, the ill-posed nature of the inversion is naturally accounted for because the RVM can produce a probabilistic output. Simulation results reveal that the proposed RVM-based approach can provide comparative performances in terms of accuracy, convergence, robustness, generalization, and improved performance in terms of sparse property in comparison with the support vector machine (SVM) based approach. (general)

Small angle neutron scattering and small angle X-ray scattering ...

Indian Academy of Sciences (India)

Abstract. The morphology of carbon nanofoam samples comprising platinum nanopar- ticles dispersed in the matrix was characterized by small angle neutron scattering (SANS) and small angle X-ray scattering (SAXS) techniques. Results show that the structure of pores of carbon matrix exhibits a mass (pore) fractal nature ...

Propagation and scattering in Lower Hybrid Current Drive (LHCD)

International Nuclear Information System (INIS)

Horton, W.; Goniche, M.; Peysson, Y.; Decker, J.; Ekedahl, A.; Litaudon, X.

2015-01-01

Full text of publication follows. The propagation and scattering of the 5 GHz RF waves planned for driving and controlling the plasma current in stage 2 of ITER is analyzed with theory, simulations and data from Tore Supra. The internal RF wavenumber spectrum is determined by a combination of elements including the (1) the azimuthal spectrum launched by the antenna, (2) coupling of the radial and azimuthal oscillations of the ray trajectories described the ray Hamiltonian with the radial and the poloidal variation of plasma and scattering from the drift wave turbulence (ref. 1, 2). The scattering of the RF waves from the drift wave turbulence in the plasma is described through a Fokker-Planck equation for the probability density of the rays. The new 4D ray kinetic equation has (1) an edge source from the antenna, (2) a core sink from the electron resonances, and (3) a global scattering rate tensor D ij (k,r,t) derived from the ambient plasma turbulence. The tensor reduces to a parallel and cross-field component with the cross-field component describing side-scatter of the RF waves. The solutions give a spectral distribution for the parallel index of refraction from the antenna to the region of three times the core electron thermal velocity. Strong absorption of the rays occurs where the plateau in the fast electron distribution joins the steeply increasing slope of the thermal electron phase space density (ref. 3). Solutions of the ray kinetic equation with the source, sink and scattering provide the filling of the spectral gap and the efficiency of the LHCD system. The ETG turbulence is modified by the temperature anisotropies and the sharp radial gradients of the LHCD electron distribution function (ref. 3). In the presence of the ETG turbulence projections of the partial differential equations to low-order transport models are derived with dynamical feed-forward/ feedback loops following L-H-ELM modeling (ref. 4). The low-order models may be used with feedback

Linear systems formulation of scattering theory for rough surfaces with arbitrary incident and scattering angles.

Science.gov (United States)

Krywonos, Andrey; Harvey, James E; Choi, Narak

2011-06-01

Scattering effects from microtopographic surface roughness are merely nonparaxial diffraction phenomena resulting from random phase variations in the reflected or transmitted wavefront. Rayleigh-Rice, Beckmann-Kirchhoff. or Harvey-Shack surface scatter theories are commonly used to predict surface scatter effects. Smooth-surface and/or paraxial approximations have severely limited the range of applicability of each of the above theoretical treatments. A recent linear systems formulation of nonparaxial scalar diffraction theory applied to surface scatter phenomena resulted first in an empirically modified Beckmann-Kirchhoff surface scatter model, then a generalized Harvey-Shack theory that produces accurate results for rougher surfaces than the Rayleigh-Rice theory and for larger incident and scattered angles than the classical Beckmann-Kirchhoff and the original Harvey-Shack theories. These new developments simplify the analysis and understanding of nonintuitive scattering behavior from rough surfaces illuminated at arbitrary incident angles.

Angular distribution for the elastic scattering of electrons from Ar+(3s23p52P) above the first inelastic threshold

International Nuclear Information System (INIS)

Brotton, S.J.; McKenna, P.; Gribakin, G.; Williams, I.D.

2002-01-01

The measured angular differential cross section (DCS) for the elastic scattering of electrons from Ar + (3s 2 3p 5 2 P) at the collision energy of 16 eV is presented. By solving the Hartree-Fock equations, we calculate the corresponding theoretical DCS including the coupling between the orbital angular momenta and spin of the incident electron and those of the target ion and also relaxation effects. Since the collision energy is above one inelastic threshold for the transition 3s 2 3p 5 2 P-3s3p 6 2 S, we consider the effects on the DCS of inelastic absorption processes and elastic resonances. The measurements deviate significantly from the Rutherford cross section over the full angular range observed, especially in the region of a deep minimum centered at approximately 75 deg. Our theory and an uncoupled, unrelaxed method using a local, spherically symmetric potential by Manson [Phys. Rev. 182, 97 (1969)] both reproduce the overall shape of the measured DCS, although the coupled Hartree-Fock approach describes the depth of the minimum more accurately. The minimum is shallower in the present theory owing to our lower average value for the d-wave non-Coulomb phase shift σ 2 , which is due to the high sensitivity of σ 2 to the different scattering potentials used in the two models. The present measurements and calculations therefore show the importance of including coupling and relaxation effects when accurately modeling electron-ion collisions. The phase shifts obtained by fitting to the measurements are compared with the values of Manson and the present method

Minimum emittance in TBA and MBA lattices

Science.gov (United States)

Xu, Gang; Peng, Yue-Mei

2015-03-01

For reaching a small emittance in a modern light source, triple bend achromats (TBA), theoretical minimum emittance (TME) and even multiple bend achromats (MBA) have been considered. This paper derived the necessary condition for achieving minimum emittance in TBA and MBA theoretically, where the bending angle of inner dipoles has a factor of 31/3 bigger than that of the outer dipoles. Here, we also calculated the conditions attaining the minimum emittance of TBA related to phase advance in some special cases with a pure mathematics method. These results may give some directions on lattice design.

Minimum emittance in TBA and MBA lattices

International Nuclear Information System (INIS)

Xu Gang; Peng Yuemei

2015-01-01

For reaching a small emittance in a modern light source, triple bend achromats (TBA), theoretical minimum emittance (TME) and even multiple bend achromats (MBA) have been considered. This paper derived the necessary condition for achieving minimum emittance in TBA and MBA theoretically, where the bending angle of inner dipoles has a factor of 3 1/3 bigger than that of the outer dipoles. Here, we also calculated the conditions attaining the minimum emittance of TBA related to phase advance in some special cases with a pure mathematics method. These results may give some directions on lattice design. (authors)

Effect of detector collimator and sample thickness on 0.662 MeV multiply Compton-scattered gamma rays

International Nuclear Information System (INIS)

Singh, Manpreet; Singh, Gurvinderjit; Sandhu, B.S.; Singh, Bhajan

2006-01-01

The simultaneous effect of detector collimator and sample thickness on 0.662 MeV multiply Compton-scattered gamma photons was studied experimentally. An intense collimated beam, obtained from 6-Ci 137 Cs source, is allowed to impinge on cylindrical aluminium samples of varying diameter and the scattered photons are detected by a 51 mmx51 mm NaI(Tl) scintillation detector placed at 90 o to the incident beam. The full energy peak corresponding to singly scattered events is reconstructed analytically. The thickness at which the multiply scattered events saturate is determined for different detector collimators. The parameters like signal-to-noise ratio and multiply scatter fraction (MSF) have also been deduced and support the work carried out by Shengli et al. [2000. EGS4 simulation of Compton scattering for nondestructive testing. KEK proceedings 200-20, Tsukuba, Japan, pp. 216-223] and Barnea et al. [1995. A study of multiple scattering background in Compton scatter imaging. NDT and E International 28, 155-162] based upon Monte Carlo calculations

25 CFR 47.9 - What are the minimum requirements for the local educational financial plan?

Science.gov (United States)

2010-04-01

... EDUCATION UNIFORM DIRECT FUNDING AND SUPPORT FOR BUREAU-OPERATED SCHOOLS § 47.9 What are the minimum..., including each program funded through the Indian School Equalization Program; (2) A budget showing the costs...) Certification by the chairman of the school board that the plan has been ratified in an action of record by the...

SU-E-I-55: The Contribution to Skin Dose Due to Scatter From the Patient Table and the Head Holder During Fluoroscopy

International Nuclear Information System (INIS)

Islam, N; Xiong, Z; Vijayan, S; Rudin, S; Bednarek, D

2015-01-01

Purpose: To determine contributions to skin dose due to scatter from the table and head holder used during fluoroscopy, and also to explore alternative design material to reduce the scatter dose. Methods: Measurements were made of the primary and scatter components of the xray beam exiting the patient table and a cylindrical head holder used on a Toshiba Infinix c-arm unit as a function of kVp for the various beam filters on the machine and for various field sizes. The primary component of the beam was measured in air with the object placed close to the x-ray tube with an air gap between it and a 6 cc parallel-plate ionization chamber and with the beam collimated to a size just larger than the chamber. The primary plus scatter radiation components were measured with the object moved to a position in the beam next to the chamber for larger field sizes. Both sets of measurements were preformed while keeping the source-to-chamber distance fixed. The scatter fraction was estimated by taking the ratio of the difference between the two measurements and the reading that included both primary and scatter. Similar measurements were also made for a 2.3 cm thick Styrofoam block which could substitute for the patient support. Results: The measured scatter fractions indicate that the patient table as well as the head holder contributes an additional 10–16% to the patient entrance dose depending on field size. Forward scatter was reduced with the Styrofoam block so that the scatter fraction was about 4–5%. Conclusion: The results of this investigation demonstrated that scatter from the table and head holder used in clinical fluoroscopy contribute substantially to the skin dose. The lower contribution of scatter from Styrofoam suggests that there is an opportunity to redesign patient support accessories to reduce the skin dose. Partial support from NIH grant R01EB002873 and Toshiba Medical Systems Corporation Equipment Grant

SU-E-I-55: The Contribution to Skin Dose Due to Scatter From the Patient Table and the Head Holder During Fluoroscopy

Energy Technology Data Exchange (ETDEWEB)

Islam, N; Xiong, Z; Vijayan, S; Rudin, S; Bednarek, D [Toshiba Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY (United States)

2015-06-15

Purpose: To determine contributions to skin dose due to scatter from the table and head holder used during fluoroscopy, and also to explore alternative design material to reduce the scatter dose. Methods: Measurements were made of the primary and scatter components of the xray beam exiting the patient table and a cylindrical head holder used on a Toshiba Infinix c-arm unit as a function of kVp for the various beam filters on the machine and for various field sizes. The primary component of the beam was measured in air with the object placed close to the x-ray tube with an air gap between it and a 6 cc parallel-plate ionization chamber and with the beam collimated to a size just larger than the chamber. The primary plus scatter radiation components were measured with the object moved to a position in the beam next to the chamber for larger field sizes. Both sets of measurements were preformed while keeping the source-to-chamber distance fixed. The scatter fraction was estimated by taking the ratio of the difference between the two measurements and the reading that included both primary and scatter. Similar measurements were also made for a 2.3 cm thick Styrofoam block which could substitute for the patient support. Results: The measured scatter fractions indicate that the patient table as well as the head holder contributes an additional 10–16% to the patient entrance dose depending on field size. Forward scatter was reduced with the Styrofoam block so that the scatter fraction was about 4–5%. Conclusion: The results of this investigation demonstrated that scatter from the table and head holder used in clinical fluoroscopy contribute substantially to the skin dose. The lower contribution of scatter from Styrofoam suggests that there is an opportunity to redesign patient support accessories to reduce the skin dose. Partial support from NIH grant R01EB002873 and Toshiba Medical Systems Corporation Equipment Grant.

Critical scattering

International Nuclear Information System (INIS)

Stirling, W.G.; Perry, S.C.

1996-01-01

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 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

41 CFR 50-202.2 - Minimum wage in all industries.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Minimum wage in all... Public Contracts PUBLIC CONTRACTS, DEPARTMENT OF LABOR 202-MINIMUM WAGE DETERMINATIONS Groups of Industries § 50-202.2 Minimum wage in all industries. In all industries, the minimum wage applicable to...

A hybrid Scatter/Transform cloaking model

Directory of Open Access Journals (Sweden)

Gad Licht

2015-01-01

Full Text Available A new Scatter/Transform cloak is developed that combines the light bending of refraction characteristic of a Transform cloak with the scatter cancellation characteristic of a Scatter cloak. The hybrid cloak incorporates both Transform’s variable index of refraction with modified linear intrusions to maximize the Scatter cloak effect. Scatter/Transform improved the scattering cross-section of cloaking in a 2-dimensional space to 51.7% compared to only 39.6% or 45.1% respectively with either Scatter or Transform alone. Metamaterials developed with characteristics based on the new ST hybrid cloak will exhibit superior cloaking capabilities.

29 CFR 525.13 - Renewal of special minimum wage certificates.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Renewal of special minimum wage certificates. 525.13... minimum wage certificates. (a) Applications may be filed for renewal of special minimum wage certificates.... (c) Workers with disabilities may not continue to be paid special minimum wages after notice that an...

An analytical theory of radio-wave scattering from meteoric ionization - I. Basic equation

Czech Academy of Sciences Publication Activity Database

Pecina, Petr

2016-01-01

Roč. 455, č. 2 (2016), s. 2200-2206 ISSN 0035-8711 Institutional support: RVO:67985815 Keywords : scattering * radar astronomy * meteorites Subject RIV: BN - Astronomy , Celestial Mechanics, Astrophysics Impact factor: 4.961, year: 2016

Study on the scattering law and scattering kernel of hydrogen in zirconium hydride

International Nuclear Information System (INIS)

Jiang Xinbiao; Chen Wei; Chen Da; Yin Banghua; Xie Zhongsheng

1999-01-01

The nuclear analytical model of calculating scattering law and scattering kernel for the uranium zirconium hybrid reactor is described. In the light of the acoustic and optic model of zirconium hydride, its frequency distribution function f(ω) is given and the scattering law of hydrogen in zirconium hydride is obtained by GASKET. The scattering kernel σ l (E 0 →E) of hydrogen bound in zirconium hydride is provided by the SMP code in the standard WIMS cross section library. Along with this library, WIMS is used to calculate the thermal neutron energy spectrum of fuel cell. The results are satisfied

Light scattering studies at UNICAMP

International Nuclear Information System (INIS)

Luzzi, R.; Cerdeira, H.A.; Salzberg, J.; Vasconcellos, A.R.; Frota Pessoa, S.; Reis, F.G. dos; Ferrari, C.A.; Algarte, C.A.S.; Tenan, M.A.

1975-01-01

Current theoretical studies on light scattering spectroscopy at UNICAMP is presented briefly, such as: inelastic scattering of radiation from a solid state plasma; resonant Ramman scattering; high excitation effects; saturated semiconductors and glasses

Many-body theory of charge transfer in hyperthermal atomic scattering

International Nuclear Information System (INIS)

Marston, J.B.; Andersson, D.R.; Behringer, E.R.; Cooper, B.H.; DiRubio, C.A.; Kimmel, G.A.; Richardson, C.

1993-01-01

We use the Newns-Anderson Hamiltonian to describe many-body electronic processes that occur when hyperthermal alkali atoms scatter off metallic surfaces. Following Brako and Newns, we expand the electronic many-body wave function in the number of particle-hole pairs (we keep terms up to and including a single particle-hole pair). We extend their earlier work by including level crossings, excited neutrals, and negative ions. The full set of equations of motion is integrated numerically, without further approximations, to obtain the many-body amplitudes as a function of time. The velocity and work-function dependence of final-state quantities such as the distribution of ion charges and excited atomic occupancies are compared with experiment. In particular, experiments that scatter alkali ions off clean Cu(001) surfaces in the energy range 5--1600 eV constrain the theory quantitatively. The neutralization probability of Na + ions shows a minimum at intermediate velocity in agreement with the theory. This behavior contrasts with that of K + , which shows virtually no neutralization, and with Li + , which exhibits a monotonically increasing neutral fraction with decreasing velocity. Particle-hole excitations are left behind in the metal during a fraction of the collision events; this dissipated energy is predicted to be quite small (on the order of tenths of an electron volt). Indeed, classical trajectory simulations of the surface dynamics account well for the observed energy loss, and thus provide some justification for our truncation of the equations of motion at the single particle-hole pair level. Li + scattering experiments off low work-function surfaces provide qualitative information on the importance of many-body effects. At sufficiently low work function, the negative ions predicted to occur are in fact observed

An Empirical Analysis of the Relationship between Minimum Wage ...

African Journals Online (AJOL)

An Empirical Analysis of the Relationship between Minimum Wage, Investment and Economic Growth in Ghana. ... In addition, the ratio of public investment to tax revenue must increase as minimum wage increases since such complementary changes are more likely to lead to economic growth. Keywords: minimum wage ...

Equilibrium limit of thermal conduction and boundary scattering in nanostructures.

Science.gov (United States)

Haskins, Justin B; Kınacı, Alper; Sevik, Cem; Çağın, Tahir

2014-06-28

Determining the lattice thermal conductivity (κ) of nanostructures is especially challenging in that, aside from the phonon-phonon scattering present in large systems, the scattering of phonons from the system boundary greatly influences heat transport, particularly when system length (L) is less than the average phonon mean free path (MFP). One possible route to modeling κ in these systems is through molecular dynamics (MD) simulations, inherently including both phonon-phonon and phonon-boundary scattering effects in the classical limit. Here, we compare current MD methods for computing κ in nanostructures with both L ⩽ MFP and L ≫ MFP, referred to as mean free path constrained (cMFP) and unconstrained (uMFP), respectively. Using a (10,0) CNT (carbon nanotube) as a benchmark case, we find that while the uMFP limit of κ is well-defined through the use of equilibrium MD and the time-correlation formalism, the standard equilibrium procedure for κ is not appropriate for the treatment of the cMFP limit because of the large influence of boundary scattering. To address this issue, we define an appropriate equilibrium procedure for cMFP systems that, through comparison to high-fidelity non-equilibrium methods, is shown to be the low thermal gradient limit to non-equilibrium results. Further, as a means of predicting κ in systems having L ≫ MFP from cMFP results, we employ an extrapolation procedure based on the phenomenological, boundary scattering inclusive expression of Callaway [Phys. Rev. 113, 1046 (1959)]. Using κ from systems with L ⩽ 3 μm in the extrapolation, we find that the equilibrium uMFP κ of a (10,0) CNT can be predicted within 5%. The equilibrium procedure is then applied to a variety of carbon-based nanostructures, such as graphene flakes (GF), graphene nanoribbons (GNRs), CNTs, and icosahedral fullerenes, to determine the influence of size and environment (suspended versus supported) on κ. Concerning the GF and GNR systems, we find that

12 CFR 3.6 - Minimum capital ratios.

Science.gov (United States)

2010-01-01

... should have well-diversified risks, including no undue interest rate risk exposure; excellent control... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Minimum capital ratios. 3.6 Section 3.6 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY MINIMUM CAPITAL RATIOS; ISSUANCE...

12 CFR 615.5330 - Minimum surplus ratios.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Minimum surplus ratios. 615.5330 Section 615.5330 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM FUNDING AND FISCAL AFFAIRS, LOAN POLICIES AND OPERATIONS, AND FUNDING OPERATIONS Surplus and Collateral Requirements § 615.5330 Minimum...

Incoherent Thomson scattering

NARCIS (Netherlands)

Donne, A. J. H.

1996-01-01

Thomson scattering is a very powerful diagnostic which is applied at nearly every magnetic confinement device. Depending on the experimental conditions different plasma parameters can be diagnosed. When the wave vector is much larger than the plasma Debye length, the total scattered power is

Single Crystal Diffuse Neutron Scattering

Directory of Open Access Journals (Sweden)

Richard Welberry

2018-01-01

Full Text Available Diffuse neutron scattering has become a valuable tool for investigating local structure in materials ranging from organic molecular crystals containing only light atoms to piezo-ceramics that frequently contain heavy elements. Although neutron sources will never be able to compete with X-rays in terms of the available flux the special properties of neutrons, viz. the ability to explore inelastic scattering events, the fact that scattering lengths do not vary systematically with atomic number and their ability to scatter from magnetic moments, provides strong motivation for developing neutron diffuse scattering methods. In this paper, we compare three different instruments that have been used by us to collect neutron diffuse scattering data. Two of these are on a spallation source and one on a reactor source.

Scattering of electrons from argon atoms

International Nuclear Information System (INIS)

Dasgupta, A.; Bhatia, A.K.

1985-01-01

The scattering of electrons from argon atoms is studied by the method of polarized orbitals. The 3p→d perturbed orbital calculated using the Sternheimer approximation gives the polarizability 14.29a 0 3 . The perturbation of the orbitals 1s, 2s, 2p, and 3s is taken into account by renormalizing the 3p→d orbitals to give the experimental value 11.06a 0 3 . Using only the modified orbital in the total wave function, phase shifts for various partial waves have been calculated in the exchange, exchange-adiabatic, and polarized-orbital approximations. They are compared with the results of the previous calculations. The calculated total elastic, differential, and momentum-transfer cross sections are compared with the experimental results. The elastic total cross sections obtained in the polarized-orbital approximation agree very closely with the recently measured cross sections by Jost et al. and Nickel et al. The critical point (the value of k 2 and theta at which the differential cross section is minimum) is at 0.306 eV and 80 0 , in good agreement with the measurements of Weyhreter et al

Non-eikonal effects in high-energy scattering IV. Inelastic scattering

International Nuclear Information System (INIS)

Gurvitz, S.A.; Kok, L.P.; Rinat, A.S.

1978-01-01

Amplitudes of inelastically scattered high-energy projections were calculated. In the scattering on 12 C(Tsub(P)=1 GeV) sizeable non-eikonal corrections in diffraction extrema even for relatively small q 2 are demonstrated. At least part of the anomaly in the 3 - distribution may be due to these non-eikonal effects. (B.G.)

A Discrete Scatterer Technique for Evaluating Electromagnetic Scattering from Trees

Science.gov (United States)

2016-09-01

Trees by DaHan Liao Approved for public release; distribution is unlimited. NOTICES Disclaimers The findings...for Evaluating Electromagnetic Scattering from Trees by DaHan Liao Sensors and Electron Devices Directorate, ARL...Technique for Evaluating Electromagnetic Scattering from Trees 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S

Scattering from black holes

International Nuclear Information System (INIS)

Futterman, J.A.H.; Handler, F.A.; Matzner, R.A.

1987-01-01

This book provides a comprehensive treatment of the propagation of waves in the presence of black holes. While emphasizing intuitive physical thinking in their treatment of the techniques of analysis of scattering, the authors also include chapters on the rigorous mathematical development of the subject. Introducing the concepts of scattering by considering the simplest, scalar wave case of scattering by a spherical (Schwarzschild) black hole, the book then develops the formalism of spin weighted spheroidal harmonics and of plane wave representations for neutrino, electromagnetic, and gravitational scattering. Details and results of numerical computations are given. The techniques involved have important applications (references are given) in acoustical and radar imaging

Applications of inverse and algebraic scattering theories

Energy Technology Data Exchange (ETDEWEB)

Amos, K. [Qinghua Univ., Beijing, BJ (China). Dept. of Physics

1997-06-01

Inverse scattering theories, algebraic scattering theory and exactly solvable scattering potentials are diverse ways by which scattering potentials can be defined from S-functions specified by fits to fixed energy, quantal scattering data. Applications have been made in nuclear (heavy ion and nucleon-nucleus scattering), atomic and molecular (electron scattering from simple molecules) systems. Three inverse scattering approaches are considered in detail; the semiclassical WKB and fully quantal Lipperheide-Fiedeldey method, than algebraic scattering theory is applied to heavy ion scattering and finally the exactly solvable Ginocchio potentials. Some nuclear results are ambiguous but the atomic and molecular inversion potentials are in good agreement with postulated forms. 21 refs., 12 figs.

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.

High energy deeply virtual Compton scattering on a photon and related meson exclusive production

International Nuclear Information System (INIS)

Machado, Magno V. T.

2007-01-01

In this work we estimate the differential cross section for the high energy deeply virtual Compton scattering on a photon target, γ*γ→γγ, within the QCD dipole-dipole scattering formalism. For the phenomenology, a saturation model for the dipole-dipole cross section for two photon scattering is considered. Its robustness is supported by a good description of current accelerator data. In addition, we consider the related exclusive vector meson production processes, γ*γ→Vγ. This analysis is focused on the light ρ and φ meson production, which produces larger cross sections. The phenomenological results are compared with the theoretical calculation using the color-dipole Balitsky-Fadin-Kuraev-Lipatov approach

Improved Limits on Scattering of Weakly Interacting Massive Particles from Reanalysis of 2013 LUX Data

Science.gov (United States)

Akerib, D. S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Bradley, A.; Bramante, R.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chapman, J. J.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; de Viveiros, L.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Ihm, M.; Jacobsen, R. G.; Ji, W.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Malling, D. C.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Ott, R. A.; Palladino, K. J.; Pangilinan, M.; Pease, E. K.; Phelps, P.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration

2016-04-01

We present constraints on weakly interacting massive particles (WIMP)-nucleus scattering from the 2013 data of the Large Underground Xenon dark matter experiment, including 1.4 ×104 kg day of search exposure. This new analysis incorporates several advances: single-photon calibration at the scintillation wavelength, improved event-reconstruction algorithms, a revised background model including events originating on the detector walls in an enlarged fiducial volume, and new calibrations from decays of an injected tritium β source and from kinematically constrained nuclear recoils down to 1.1 keV. Sensitivity, especially to low-mass WIMPs, is enhanced compared to our previous results which modeled the signal only above a 3 keV minimum energy. Under standard dark matter halo assumptions and in the mass range above 4 GeV c-2 , these new results give the most stringent direct limits on the spin-independent WIMP-nucleon cross section. The 90% C.L. upper limit has a minimum of 0.6 zb at 33 GeV c-2 WIMP mass.

5 CFR 551.601 - Minimum age standards.

Science.gov (United States)

2010-01-01

... ADMINISTRATION UNDER THE FAIR LABOR STANDARDS ACT Child Labor § 551.601 Minimum age standards. (a) 16-year... subject to its child labor provisions, with certain exceptions not applicable here. (b) 18-year minimum... occupation found and declared by the Secretary of Labor to be particularly hazardous for the employment of...

12 CFR 932.8 - Minimum liquidity requirements.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Minimum liquidity requirements. 932.8 Section... CAPITAL STANDARDS FEDERAL HOME LOAN BANK CAPITAL REQUIREMENTS § 932.8 Minimum liquidity requirements. In addition to meeting the deposit liquidity requirements contained in § 965.3 of this chapter, each Bank...

[Hospitals failing minimum volumes in 2004: reasons and consequences].

Science.gov (United States)

Geraedts, M; Kühnen, C; Cruppé, W de; Blum, K; Ohmann, C

2008-02-01

In 2004 Germany introduced annual minimum volumes nationwide on five surgical procedures: kidney, liver, stem cell transplantation, complex oesophageal, and pancreatic interventions. Hospitals that fail to reach the minimum volumes are no longer allowed to perform the respective procedures unless they raise one of eight legally accepted exceptions. The goal of our study was to investigate how many hospitals fell short of the minimum volumes in 2004, whether and how this was justified, and whether hospitals that failed the requirements experienced any consequences. We analysed data on meeting the minimum volume requirements in 2004 that all German hospitals were obliged to publish as part of their biannual structured quality reports. We performed telephone interviews: a) with all hospitals not achieving the minimum volumes for complex oesophageal, and pancreatic interventions, and b) with the national umbrella organisations of all German sickness funds. In 2004, one quarter of all German acute care hospitals (N=485) performed 23,128 procedures where minimum volumes applied. 197 hospitals (41%) did not meet at least one of the minimum volumes. These hospitals performed N=715 procedures (3.1%) where the minimum volumes were not met. In 43% of these cases the hospitals raised legally accepted exceptions. In 33% of the cases the hospitals argued using reasons that were not legally acknowledged. 69% of those hospitals that failed to achieve the minimum volumes for complex oesophageal and pancreatic interventions did not experience any consequences from the sickness funds. However, one third of those hospitals reported that the sickness funds addressed the issue and partially announced consequences for the future. The sickness funds' umbrella organisations stated that there were only sparse activities related to the minimum volumes and that neither uniform registrations nor uniform proceedings in case of infringements of the standards had been agreed upon. In spite of the

Bidirectional optical scattering facility

Data.gov (United States)

Federal Laboratory Consortium — Goniometric optical scatter instrument (GOSI)The bidirectional reflectance distribution function (BRDF) quantifies the angular distribution of light scattered from a...

The Distribution of the Sample Minimum-Variance Frontier

OpenAIRE

Raymond Kan; Daniel R. Smith

2008-01-01

In this paper, we present a finite sample analysis of the sample minimum-variance frontier under the assumption that the returns are independent and multivariate normally distributed. We show that the sample minimum-variance frontier is a highly biased estimator of the population frontier, and we propose an improved estimator of the population frontier. In addition, we provide the exact distribution of the out-of-sample mean and variance of sample minimum-variance portfolios. This allows us t...

Instantons in the QCD vacuum and in deep inelastic scattering

International Nuclear Information System (INIS)

Ringwald, A.; Schrempp, F.

1999-01-01

We give a brief status report on our on-going investigation of the prospects to discover QCD instantons in deep inelastic scattering (DIS) at HERA. A recent high-quality lattice study of the topological structure of the QCD vacuum is exploited to provide crucial support of our predictions for DIS, based on instanton perturbation theory

Forbidden Raman scattering processes. I. General considerations and E1--M1 scattering

International Nuclear Information System (INIS)

Harney, R.C.

1979-01-01

The generalized theory of forbidden Raman scattering processes is developed in terms of the multipole expansion of the electromagnetic interaction Hamiltonian. Using the general expressions, the theory of electric dipole--magnetic dipole (E1--M1) Raman scattering is derived in detail. The 1 S 0 → 3 P 1 E1--M1 Raman scattering cross section in atomic magnesium is calculated for two applicable laser wavelengths using published f-value data. Since resonantly enhanced cross sections larger than 10 -29 cm 2 /sr are predicted it should be possible to experimentally observe this scattering phenomenon. In addition, by measuring the frequency dependence of the cross section near resonance, it may be possible to directly determine the relative magnitudes of the Axp and AxA contributions to the scattering cross section. Finally, possible applications of the effect in atomic and molecular physics are discussed

Screening-induced surface polar optical phonon scattering in dual-gated graphene field effect transistors

Energy Technology Data Exchange (ETDEWEB)

Hu, Bo, E-mail: hubo2011@semi.ac.cn

2015-03-15

The effect of surface polar optical phonons (SOs) from the dielectric layers on electron mobility in dual-gated graphene field effect transistors (GFETs) is studied theoretically. By taking into account SO scattering of electron as a main scattering mechanism, the electron mobility is calculated by the iterative solution of Boltzmann transport equation. In treating scattering with the SO modes, the dynamic dielectric screening is included and compared to the static dielectric screening and the dielectric screening in the static limit. It is found that the dynamic dielectric screening effect plays an important role in the range of low net carrier density. More importantly, in-plane acoustic phonon scattering and charged impurity scattering are also included in the total mobility for SiO{sub 2}-supported GFETs with various high-κ top-gate dielectric layers considered. The calculated total mobility results suggest both Al{sub 2}O{sub 3} and AlN are the promising candidate dielectric layers for the enhancement in room temperature mobility of graphene in the future.

Haag-Ruelle scattering theory as a scattering theory in different spaces of states

International Nuclear Information System (INIS)

Koshmanenko, V.D.

1979-01-01

The aim of the paper is the extraction of the abstract content from the Haag-Ruelle theory, i.e. to find out the total mathematical scheme of the theory without the account of physical axiomatics. It is shown that the Haag-Ruelle scattering theory may be naturally included into the scheme of the abstract theory of scattering with the pair of spaces, the wave operators being determined by the method of bilinear functionals. A number of trivial features of the scattering operator is found in the abstract theory. The concrete prospects of the application of the data obtained are outlined in the problem of the scattering of the field quantum theory

Interface morphology of Mo/Si multilayer systems with varying Mo layer thickness studied by EUV diffuse scattering.

Science.gov (United States)

Haase, Anton; Soltwisch, Victor; Braun, Stefan; Laubis, Christian; Scholze, Frank

2017-06-26

We investigate the influence of the Mo-layer thickness on the EUV reflectance of Mo/Si mirrors with a set of unpolished and interface-polished Mo/Si/C multilayer mirrors. The Mo-layer thickness is varied in the range from 1.7 nm to 3.05 nm. We use a novel combination of specular and diffuse intensity measurements to determine the interface roughness throughout the multilayer stack and do not rely on scanning probe measurements at the surface only. The combination of EUV and X-ray reflectivity measurements and near-normal incidence EUV diffuse scattering allows to reconstruct the Mo layer thicknesses and to determine the interface roughness power spectral density. The data analysis is conducted by applying a matrix method for the specular reflection and the distorted-wave Born approximation for diffuse scattering. We introduce the Markov-chain Monte Carlo method into the field in order to determine the respective confidence intervals for all reconstructed parameters. We unambiguously detect a threshold thickness for Mo in both sample sets where the specular reflectance goes through a local minimum correlated with a distinct increase in diffuse scatter. We attribute that to the known appearance of an amorphous-to-crystallization transition at a certain thickness threshold which is altered in our sample system by the polishing.

24 CFR 891.145 - Owner deposit (Minimum Capital Investment).

Science.gov (United States)

2010-04-01

... General Program Requirements § 891.145 Owner deposit (Minimum Capital Investment). As a Minimum Capital... Investment shall be one-half of one percent (0.5%) of the HUD-approved capital advance, not to exceed $25,000. ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Owner deposit (Minimum Capital...

Observations of resonance-like structures for positron-atom scattering at intermediate energies

International Nuclear Information System (INIS)

Dou, L.

1993-01-01

Absolute values of elastic differential cross sections (DCS's) are measured for position (e + ) scattering by argon (8.7-300 eV) krypton (6.7-400 eV) and also neon (13.6-400 eV) using a crossed-beam experimental setup. When the DCS's are plotted at fixed scattering angles of 30 degrees, 60 degrees, 90 degrees and 120 degrees versus energy it has been found that well-defined resonance-like structures are found at an energy of 55-60 eV for argon and at 25 and 200 eV for krypton, with a broader structure found between 100-200 eV for neon. These observed resonance-like structures are unusual because they occur at energies well above the known inelastic thresholds for these atoms. They may represent examples of open-quotes coupled channel shape resonancesclose quotes, first predicted by Higgins and Burke [1] for e + -H scattering in the vicinity of 36 eV (width ∼ 4 eV), which occurs only when both the elastic and positronium formation scattering channels are considered together. A more recent e + -H calculation by Hewitt et al. [2] supports the Higgins and Burke prediction. These predictions and the present observations suggest the existence of a new type of atomic scattering resonance

Stationary theory of scattering

International Nuclear Information System (INIS)

Kato, T.

1977-01-01

A variant of the stationary methods is described, and it is shown that it is useful in a wide range of problems, including scattering, by long-range potentials, two-space scattering, and multichannel scattering. The method is based on the notion of spectral forms. The paper is restricted to the simplest case of continuous spectral forms defined on a Banach space embedded in the basic Hilbert space. (P.D.)

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Scattering resonances in a low-dimensional Rashba-Dresselhaus spin-orbit coupled quantum gas

Science.gov (United States)

Wang, Su-Ju; Blume, D.

2017-04-01

Confinement-induced resonances allow for the tuning of the effective one-dimensional coupling constant. When the scattering state associated with the ground transverse mode is brought into resonance with the bound state attached to the energetically excited transverse modes, the atoms interact through an infinitely strong repulsion. This provides a route to realize the Tonks-Girardeau gas. On the other hand, the realization of synthetic gauge fields in cold atomic systems has attracted a lot of attention. For instance, bound-state formation is found to be significantly modified in the presence of spin-orbit coupling in three dimensions. This motivates us to study ultracold collisions between two Rashba-Dresselhaus spin-orbit coupled atoms in a quasi-one-dimensional geometry. We develop a multi-channel scattering formalism that accounts for the external transverse confinement and the spin-orbit coupling terms. The interplay between these two single-particle terms is shown to give rise to new scattering resonances. In particular, it is analyzed what happens when the scattering energy crosses the various scattering thresholds that arise from the single-particle confinement and the spin-orbit coupling. Support by the NSF is gratefully acknowledged.

P-wave scattering and the distribution of heterogeneity around Etna volcano

Directory of Open Access Journals (Sweden)

Toni Zieger

2016-09-01

Full Text Available Volcanoes and fault zones are areas of increased heterogeneity in the Earth crust that leads to strong scattering of seismic waves. For the understanding of the volcanic structure and the role of attenuation and scattering processes it is important to investigate the distribution of heterogeneity. We used the signals of air-gun shots to investigate the distribution of heterogeneity around Mount Etna. We devise a new methodology that is based on the coda energy ratio which we define as the ratio between the energy of the direct P-wave and the energy in a later coda window. This is based on the basic assumption that scattering caused by heterogeneity removes energy from the direct P-waves. We show that measurements of the energy ratio are stable with respect to changes of the details of the time windows definitions. As an independent proxy of the scattering strength along the ray path we measure the peak delay time of the direct P-wave. The peak delay time is well correlated with the coda energy ratio. We project the observation in the directions of the incident rays at the stations. Most notably is an area with increased wave scattering in the volcano and east of it. The strong heterogeneity found supports earlier observations and confirms the possibility to use P-wave sources for the determination of scattering properties. We interpret the extension of the highly heterogeneous zone towards the east as a potential signature of inelastic deformation processes induced by the eastward sliding of flank of the volcano.

The minimum information about a genome sequence (MIGS) specification

DEFF Research Database (Denmark)

Field, D; Garrity, G; Gray, T

2008-01-01

With the quantity of genomic data increasing at an exponential rate, it is imperative that these data be captured electronically, in a standard format. Standardization activities must proceed within the auspices of open-access and international working bodies. To tackle the issues surrounding the...... that will be required to develop improved mechanisms of metadata capture and exchange. As part of its wider goals, the GSC also supports improving the 'transparency' of the information contained in existing genomic databases....... the development of better descriptions of genomic investigations, we have formed the Genomic Standards Consortium (GSC). Here, we introduce the minimum information about a genome sequence (MIGS) specification with the intent of promoting participation in its development and discussing the resources...

Scattering theory and chemical reactions

International Nuclear Information System (INIS)

Kuppermann, A.

1988-01-01

In this course, scattering theory and chemical reactions are presented including scattering of one particle by a potential, n-particle systems, colinear triatomic molecules and the study of reactive scattering for 3-dimensional triatomic systems. (A.C.A.S.) [pt

Hierarchical nanoparticle morphology for platinum supported on SrTiO3 (0 0 1): A combined microscopy and X-ray scattering study

International Nuclear Information System (INIS)

Christensen, Steven T.; Lee, Byeongdu; Feng Zhenxing; Hersam, Mark C.; Bedzyk, Michael J.

2009-01-01

The morphology of metal nanoparticles supported on oxide substrates plays an important role in heterogeneous catalysis and in the nucleation of thin films. For platinum evaporated onto SrTiO 3 (0 0 1) and vacuum annealed we find an unexpected growth formation of Pt nanoparticles that aggregate into clusters without coalescence. This hierarchical nanoparticle morphology with an enhanced surface-to-volume ratio for Pt is analyzed by grazing incidence small-angle X-ray scattering (GISAXS), X-ray fluorescence (XRF), atomic force microscopy (AFM) and high-resolution scanning electron microscopy (SEM). The nanoparticle constituents of the clusters measure 2-4 nm in size and are nearly contiguously spaced where the average edge-to-edge spacing is less than 1 nm. These particles make up the clusters, which are 10-50 nm in diameter and are spaced on the order of 100 nm apart.

Polarized X-ray excitation for scatter reduction in X-ray fluorescence computed tomography.

Science.gov (United States)

Vernekohl, Don; Tzoumas, Stratis; Zhao, Wei; Xing, Lei

2018-05-25

reconstruction showed that for a scatter magnitude decrease by a factor of 2.4, the molecular sensitivity could almost be doubled. Scatter reduction lowers the amount of noise in the projection datasets and reconstructed images which enhances molecular sensitivity at equal dose. The results support the use of linear polarized X-rays to reduce scatter in XFCT imaging. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Minimum Wages and the Distribution of Family Incomes

OpenAIRE

Dube, Arindrajit

2017-01-01

Using the March Current Population Survey data from 1984 to 2013, I provide a comprehensive evaluation of how minimum wage policies influence the distribution of family incomes. I find robust evidence that higher minimum wages shift down the cumulative distribution of family incomes at the bottom, reducing the share of non-elderly individuals with incomes below 50, 75, 100, and 125 percent of the federal poverty threshold. The long run (3 or more years) minimum wage elasticity of the non-elde...

7 CFR 1610.5 - Minimum Bank loan.

Science.gov (United States)

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Minimum Bank loan. 1610.5 Section 1610.5 Agriculture Regulations of the Department of Agriculture (Continued) RURAL TELEPHONE BANK, DEPARTMENT OF AGRICULTURE LOAN POLICIES § 1610.5 Minimum Bank loan. A Bank loan will not be made unless the applicant qualifies for a Bank...

Minimum Wage Effects in the Longer Run

Science.gov (United States)

Neumark, David; Nizalova, Olena

2007-01-01

Exposure to minimum wages at young ages could lead to adverse longer-run effects via decreased labor market experience and tenure, and diminished education and training, while beneficial longer-run effects could arise if minimum wages increase skill acquisition. Evidence suggests that as individuals reach their late 20s, they earn less the longer…

29 CFR 783.43 - Computation of seaman's minimum wage.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Computation of seaman's minimum wage. 783.43 Section 783.43...'s minimum wage. Section 6(b) requires, under paragraph (2) of the subsection, that an employee...'s minimum wage requirements by reason of the 1961 Amendments (see §§ 783.23 and 783.26). Although...

12 CFR 931.3 - Minimum investment in capital stock.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Minimum investment in capital stock. 931.3... CAPITAL STANDARDS FEDERAL HOME LOAN BANK CAPITAL STOCK § 931.3 Minimum investment in capital stock. (a) A Bank shall require each member to maintain a minimum investment in the capital stock of the Bank, both...

Astrophysical applications of Delbrück scattering: Dust scattered gamma radiation from gamma ray bursts

International Nuclear Information System (INIS)

Kunwar, B.; Bhadra, A.; Gupta, S.K. Sen

2014-01-01

A preliminary, and perhaps the first, study of astrophysical applications of Delbrück scattering in a gamma-ray emitting celestial object like a gamma-ray burst (GRB) has been made. At energies≥100 MeV the elastic scattering of gamma-ray photons off the molecular dust surrounding the GRB site is dominated by Delbrück scattering. Expressions for Delbrück-scattered gamma-ray flux as a function of time has been obtained for a few selected energies by assuming a simple model of GRB. These are compared with Compton-scattered flux. At certain situations, interestingly, the former is found to exceed the latter for the first few milliseconds of the burst. The issue of detectability of Delbrück-scattered gamma-ray echo from the cloud of a GRB is discussed. Although it is observed that the detection of such an echo is not within the capability of the presently operating gamma-ray missions such as Fermi LAT, a rough estimate shows that one can be optimistic that future generation gamma-ray telescopes might be able to see such photons' contribution to the total flux. - Highlights: ► Astrophysical application of Delbrück scattering in a GRB has been made. ► Initially, the Delbrück scattering may dominate the scattering of GeV γ-rays. ► The issue of detectability of such radiations is discussed

Scattered-field FDTD and PSTD algorithms with CPML absorbing boundary conditions for light scattering by aerosols

International Nuclear Information System (INIS)

Sun, Wenbo; Videen, Gorden; Fu, Qiang; Hu, Yongxiang

2013-01-01

As fundamental parameters for polarized-radiative-transfer calculations, the single-scattering phase matrix of irregularly shaped aerosol particles must be accurately modeled. In this study, a scattered-field finite-difference time-domain (FDTD) model and a scattered-field pseudo-spectral time-domain (PSTD) model are developed for light scattering by arbitrarily shaped dielectric aerosols. The convolutional perfectly matched layer (CPML) absorbing boundary condition (ABC) is used to truncate the computational domain. It is found that the PSTD method is generally more accurate than the FDTD in calculation of the single-scattering properties given similar spatial cell sizes. Since the PSTD can use a coarser grid for large particles, it can lower the memory requirement in the calculation. However, the Fourier transformations in the PSTD need significantly more CPU time than simple subtractions in the FDTD, and the fast Fourier transform requires a power of 2 elements in calculations, thus using the PSTD could not significantly reduce the CPU time required in the numerical modeling. Furthermore, because the scattered-field FDTD/PSTD equations include incident-wave source terms, the FDTD/PSTD model allows for the inclusion of an arbitrarily incident wave source, including a plane parallel wave or a Gaussian beam like those emitted by lasers usually used in laboratory particle characterizations, etc. The scattered-field FDTD and PSTD light-scattering models can be used to calculate single-scattering properties of arbitrarily shaped aerosol particles over broad size and wavelength ranges. -- Highlights: • Scattered-field FDTD and PSTD models are developed for light scattering by aerosols. • Convolutional perfectly matched layer absorbing boundary condition is used. • PSTD is generally more accurate than FDTD in calculating single-scattering properties. • Using same spatial resolution, PSTD requires much larger CPU time than FDTD

The investigation of the elastic photon scattering cross sections by copper atoms and ions

International Nuclear Information System (INIS)

Kuplyauskene, A.B.

1976-01-01

The differential cross sections of coherent scattering of photons on a copper atom and ions Cu + and Cu 2+ and also on ions Zn + and Ga 2+ in their ground states have been studied theoretically. The energy of an incident photon has varied in the range from 0.5 keV to 200 keV, and the scattering cross sections are given for angles of 30 deg, 60 deg, 90 deg, 120 deg, 150 deg. The calculations are performed in the formfactor approximation with the use of generalized hydrogen-like analytical radial orbitals. To clarify the contribution from individual shells the cross sections of photon scattering on individual electron of shells are calculated. It follows from the calculations that when the energies of the incident photon are less than 4 keV, the main contribution into the differential cross section is made by external electrons. Then, alongside with the increase of the energy, the contribution of the electrons decreases, and the inner shells begin to play a more important role. Therefore the photon cross sections for the energies greater than 50 keV practically coincide for atoms and ions of copper. The general regularities of the cross section variation accompanying the increase of the photon energy are similar for all the elements under study. The angular dependences of cross sections are such that they decrease first and after reaching the minimum at angles of 90 deg - 120 deg increase again

Analyticity and unitarity as constraints to obtain scattering phase shifts and applications to e-He scattering

International Nuclear Information System (INIS)

Huber, H.; Lun, D.R.; Allen, L.J.; Amos, K.

1997-01-01

The requirements that the scattering functions for quantal scattering at energies below the first inelastic threshold be unitary and analytic have been used to establish a process that gives the complex scattering amplitudes from differential cross sections. From those amplitudes scattering phase shifts have been deduced by Legendre integration. The effects of the natural ambiguity of the phase of the scattering phase shifts have been deduced by Legendre integration. The effects of the natural ambiguity of the phase of the scattering amplitude, under conditions for which uniqueness and (numerical) stability of solutions are not assured, also have been developed to specify the scattering phase shifts can give stable nonspurious results. The scattering of electrons from He atoms for incident energies ranging from 1.5 to 19 eV are considered as an example of the procedure. Phase shift analyses of that data have been made with a variety of other techniques to allow a comparative study of these results and of sets with which are associated fits to cross sections that are statistically significant. 18 refs., 2 tabs., 8 figs

Minimum-Cost Reachability for Priced Timed Automata

DEFF Research Database (Denmark)

Behrmann, Gerd; Fehnker, Ansgar; Hune, Thomas Seidelin

2001-01-01

This paper introduces the model of linearly priced timed automata as an extension of timed automata, with prices on both transitions and locations. For this model we consider the minimum-cost reachability problem: i.e. given a linearly priced timed automaton and a target state, determine...... the minimum cost of executions from the initial state to the target state. This problem generalizes the minimum-time reachability problem for ordinary timed automata. We prove decidability of this problem by offering an algorithmic solution, which is based on a combination of branch-and-bound techniques...... and a new notion of priced regions. The latter allows symbolic representation and manipulation of reachable states together with the cost of reaching them....

CONFERENCE: Elastic and diffractive scattering

Energy Technology Data Exchange (ETDEWEB)

White, Alan

1989-09-15

Elastic scattering, when particles appear to 'bounce' off each other, and the related phenomena of diffractive scattering are currently less fashionable than the study of hard scattering processes. However this could change rapidly if unexpected results from the UA4 experiment at the CERN Collider are confirmed and their implications tested. These questions were highlighted at the third 'Blois Workshop' on Elastic and Diffractive Scattering, held early in May on the Evanston campus of Northwestern University, near Chicago.

Disturbance zonal and vertical plasma drifts in the Peruvian sector during solar minimum phases

Science.gov (United States)

Santos, A. M.; Abdu, M. A.; Souza, J. R.; Sobral, J. H. A.; Batista, I. S.

2016-03-01

In the present work, we investigate the behavior of the equatorial F region zonal plasma drifts over the Peruvian region under magnetically disturbed conditions during two solar minimum epochs, one of them being the recent prolonged solar activity minimum. The study utilizes the vertical and zonal components of the plasma drifts measured by the Jicamarca (11.95°S; 76.87°W) incoherent scatter radar during two events that occurred on 10 April 1997 and 24 June 2008 and model calculation of the zonal drift in a realistic ionosphere simulated by the Sheffield University Plasmasphere-Ionosphere Model-INPE. Two main points are focused: (1) the connection between electric fields and plasma drifts under prompt penetration electric field during a disturbed periods and (2) anomalous behavior of daytime zonal drift in the absence of any magnetic storm. A perfect anticorrelation between vertical and zonal drifts was observed during the night and in the initial and growth phases of the magnetic storm. For the first time, based on a realistic low-latitude ionosphere, we will show, on a detailed quantitative basis, that this anticorrelation is driven mainly by a vertical Hall electric field induced by the primary zonal electric field in the presence of an enhanced nighttime E region ionization. It is shown that an increase in the field line-integrated Hall-to-Pedersen conductivity ratio (∑H/∑P), which can arise from precipitation of energetic particles in the region of the South American Magnetic Anomaly, is capable of explaining the observed anticorrelation between the vertical and zonal plasma drifts. Evidence for the particle ionization is provided from the occurrence of anomalous sporadic E layers over the low-latitude station, Cachoeira Paulista (22.67°S; 44.9°W)—Brazil. It will also be shown that the zonal plasma drift reversal to eastward in the afternoon two hours earlier than its reference quiet time pattern is possibly caused by weakening of the zonal wind

Is the minimum enough? Affordability of a nutritious diet for minimum wage earners in Nova Scotia (2002-2012).

Science.gov (United States)

Newell, Felicia D; Williams, Patricia L; Watt, Cynthia G

2014-05-09

This paper aims to assess the affordability of a nutritious diet for households earning minimum wage in Nova Scotia (NS) from 2002 to 2012 using an economic simulation that includes food costing and secondary data. The cost of the National Nutritious Food Basket (NNFB) was assessed with a stratified, random sample of grocery stores in NS during six time periods: 2002, 2004/2005, 2007, 2008, 2010 and 2012. The NNFB's cost was factored into affordability scenarios for three different household types relying on minimum wage earnings: a household of four; a lone mother with three children; and a lone man. Essential monthly living expenses were deducted from monthly net incomes using methods that were standardized from 2002 to 2012 to determine whether adequate funds remained to purchase a basic nutritious diet across the six time periods. A 79% increase to the minimum wage in NS has resulted in a decrease in the potential deficit faced by each household scenario in the period examined. However, the household of four and the lone mother with three children would still face monthly deficits ($44.89 and $496.77, respectively, in 2012) if they were to purchase a nutritiously sufficient diet. As a social determinant of health, risk of food insecurity is a critical public health issue for low wage earners. While it is essential to increase the minimum wage in the short term, adequately addressing income adequacy in NS and elsewhere requires a shift in thinking from a focus on minimum wage towards more comprehensive policies ensuring an adequate livable income for everyone.

Neutron scattering and magnetism

International Nuclear Information System (INIS)

Mackintosh, A.R.

1983-01-01

Those properties of the neutron which make it a unique tool for the study of magnetism are described. The scattering of neutrons by magnetic solids is briefly reviewed, with emphasis on the information on the magnetic structure and dynamics which is inherent in the scattering cross-section. The contribution of neutron scattering to our understanding of magnetic ordering, excitations and phase transitions is illustrated by experimental results on a variety of magnetic crystals. (author)

Employment Effects of Minimum and Subminimum Wages. Recent Evidence.

Science.gov (United States)

Neumark, David

Using a specially constructed panel data set on state minimum wage laws and labor market conditions, Neumark and Wascher (1992) presented evidence that countered the claim that minimum wages could be raised with no cost to employment. They concluded that estimates indicating that minimum wages reduced employment on the order of 1-2 percent for a…

Minimum Wage Effects on Educational Enrollments in New Zealand

Science.gov (United States)

Pacheco, Gail A.; Cruickshank, Amy A.

2007-01-01

This paper empirically examines the impact of minimum wages on educational enrollments in New Zealand. A significant reform to the youth minimum wage since 2000 has resulted in some age groups undergoing a 91% rise in their real minimum wage over the last 10 years. Three panel least squares multivariate models are estimated from a national sample…

WE-EF-207-06: Dedicated Cone-Beam Breast CT with Laterally-Shifted Detector: Monte Carlo Evaluation of X-Ray Scatter Distribution and Scatter-To-Primary Ratio

International Nuclear Information System (INIS)

Shi, L; Vedantham, S; Karellas, A

2015-01-01

(60kVp) were 0.09/0.25/0.73 for 10/14/18-cm diameter breasts. Conclusion: CBBCT with laterally-shifted detector geometry and with appropriate kVp/beam quality reduces SPR. If residual scatter needs correction, the location corresponding to scatter-peak can be analytically computed. This work was supported in part by NIH R01 CA128906. The contents are solely the responsibility of the authors and do not reflect the official views of the NIH or NCI

Dual-window dual-bandwidth spectroscopic optical coherence tomography metric for qualitative scatterer size differentiation in tissues.

Science.gov (United States)

Tay, Benjamin Chia-Meng; Chow, Tzu-Hao; Ng, Beng-Koon; Loh, Thomas Kwok-Seng

2012-09-01

This study investigates the autocorrelation bandwidths of dual-window (DW) optical coherence tomography (OCT) k-space scattering profile of different-sized microspheres and their correlation to scatterer size. A dual-bandwidth spectroscopic metric defined as the ratio of the 10% to 90% autocorrelation bandwidths is found to change monotonically with microsphere size and gives the best contrast enhancement for scatterer size differentiation in the resulting spectroscopic image. A simulation model supports the experimental results and revealed a tradeoff between the smallest detectable scatterer size and the maximum scatterer size in the linear range of the dual-window dual-bandwidth (DWDB) metric, which depends on the choice of the light source optical bandwidth. Spectroscopic OCT (SOCT) images of microspheres and tonsil tissue samples based on the proposed DWDB metric showed clear differentiation between different-sized scatterers as compared to those derived from conventional short-time Fourier transform metrics. The DWDB metric significantly improves the contrast in SOCT imaging and can aid the visualization and identification of dissimilar scatterer size in a sample. Potential applications include the early detection of cell nuclear changes in tissue carcinogenesis, the monitoring of healing tendons, and cell proliferation in tissue scaffolds.

Tokamak T-10 multipulse laser scattering: Instrumentation modernization

International Nuclear Information System (INIS)

Baukov, V.A.; Ponomarev, A.V.; Gorshkov, A.V.; Rossikhin, B.A.; Sannikov, V.V.; Grek, B.

1994-01-01

The modernized Thomson scattering diagnostic complex of Tokamak T-10 is described. The complex is based on a high-power neodimium laser. Both the laser fundamental and second harmonics serve to find out the time-dependence of plasma electron temperature and density profiles, as well as to measure the electron distribution function. One detected the scattered laser radiation at θ = 90 degrees and 2.5 degrees angles. The new-version Nd laser generates eight-pulse sequences. The laser radiation energy is E o = 30-50 J/pulse. The radiation divergence was smaller than var-phi = 0.15 mrad. The multiple radiation parameters were found to be very stable. The operator could vary the inter-pulse time intervals within the pulse sequence. The second-harmonic radiation energy was E 2 = 10-15 J/pulse. The data acquisition and analysis system was supported by IBM/AT and Macintosh computers. 6 refs., 1 fig

Zero forcing parameters and minimum rank problems

NARCIS (Netherlands)

Barioli, F.; Barrett, W.; Fallat, S.M.; Hall, H.T.; Hogben, L.; Shader, B.L.; Driessche, van den P.; Holst, van der H.

2010-01-01

The zero forcing number Z(G), which is the minimum number of vertices in a zero forcing set of a graph G, is used to study the maximum nullity/minimum rank of the family of symmetric matrices described by G. It is shown that for a connected graph of order at least two, no vertex is in every zero

Minimum bias measurement at 13 TeV

CERN Document Server

Orlando, Nicola; The ATLAS collaboration

2017-01-01

The modelling of Minimum Bias (MB) is a crucial ingredient to learn about the description of soft QCD processes and to simulate the environment at the LHC with many concurrent pp interactions (pile-up). We summarise the ATLAS minimum bias measurements with proton-proton collision at 13 TeV center-of-mass-energy at the Large Hadron Collider.

Dynamics of chemical reactions of multiply-charged cations: Information from beam scattering experiments

Czech Academy of Sciences Publication Activity Database

Herman, Zdeněk

2015-01-01

Roč. 378, FEB 2015 (2015), s. 113-126 ISSN 1387-3806 Institutional support: RVO:61388955 Keywords : Multiply-charged ions * Dynamics of chemical reactions * Beam scattering Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.183, year: 2015

Quasielastic scattering of slow-neutron in water-alcohol solutions

Directory of Open Access Journals (Sweden)

N. O. Atamas

2010-06-01

Full Text Available Research of molecules dynamics of solutions “water - propyl alcohol” of different concentration at the temperature 281 K is conducted by the method of slow-neutron quasi-elastic scattering. There were experimentally exposed the feature of effective self-diffusion coefficient of molecules of the indicated solutions. Based on the time- scale hierarchy the division of selfdiffusion coefficient to one-particle and collective contributions was conducted, and the time of the molecules settled life in position of equilibrium was calculated. There were also exposed the feature of self-diffusion concentration dependence of coefficient of self-diffusion and his selfpart contribution, namely: presence of two minimums is in the areas of concentrations (0,04 ÷ 0,05 of mass fraction and (0,18 ÷ 0,22 m.c. of the alcohol and continuous character of diffusion at concentrations higher then 0,4 m.c. of the alcohol. It is shown that the indicated concentration areas correspond the certain local structures of investigational solution.

Minimum airflow reset of single-duct VAV terminal boxes

Science.gov (United States)

Cho, Young-Hum

Single duct Variable Air Volume (VAV) systems are currently the most widely used type of HVAC system in the United States. When installing such a system, it is critical to determine the minimum airflow set point of the terminal box, as an optimally selected set point will improve the level of thermal comfort and indoor air quality (IAQ) while at the same time lower overall energy costs. In principle, this minimum rate should be calculated according to the minimum ventilation requirement based on ASHRAE standard 62.1 and maximum heating load of the zone. Several factors must be carefully considered when calculating this minimum rate. Terminal boxes with conventional control sequences may result in occupant discomfort and energy waste. If the minimum rate of airflow is set too high, the AHUs will consume excess fan power, and the terminal boxes may cause significant simultaneous room heating and cooling. At the same time, a rate that is too low will result in poor air circulation and indoor air quality in the air-conditioned space. Currently, many scholars are investigating how to change the algorithm of the advanced VAV terminal box controller without retrofitting. Some of these controllers have been found to effectively improve thermal comfort, indoor air quality, and energy efficiency. However, minimum airflow set points have not yet been identified, nor has controller performance been verified in confirmed studies. In this study, control algorithms were developed that automatically identify and reset terminal box minimum airflow set points, thereby improving indoor air quality and thermal comfort levels, and reducing the overall rate of energy consumption. A theoretical analysis of the optimal minimum airflow and discharge air temperature was performed to identify the potential energy benefits of resetting the terminal box minimum airflow set points. Applicable control algorithms for calculating the ideal values for the minimum airflow reset were developed and

Pion scattering from very light nuclei

International Nuclear Information System (INIS)

Berman, B.

1993-01-01

Selected recent elastic and inelastic pion-scattering experiments on 3 H, 3 He, and 4 He will be reviewed. Particular attention will be given to multinucleon or cluster aspects of the data, and to possible comparisons with electron-scattering results. From elastic scattering from 3 H and 3 He at forward angles, one can extract the matter distribution of the paired neutrons in 3 H as well as that of the paired protons in 3 He. At backward angles, scattering from correlated nucleon pairs and/or two-step processes play an important role. For inelastic scattering, the momentum-transfer dependence of the cross section varies strongly with incident energy. Elastic scattering from a polarized 3 He target shows a strong asymmetry near 90 degrees. Elastic scattering from 4 He yields results which cannot be fitted with a simple optical model. An for inelastic scattering from 4 He, analysis of the data requires an important contribution from direct triton knockout

Hermite scatterers in an ultraviolet sky

Science.gov (United States)

Parker, Kevin J.

2017-12-01

The scattering from spherical inhomogeneities has been a major historical topic in acoustics, optics, and electromagnetics and the phenomenon shapes our perception of the world including the blue sky. The long wavelength limit of ;Rayleigh scattering; is characterized by intensity proportional to k4 (or λ-4) where k is the wavenumber and λ is the wavelength. With the advance of nanotechnology, it is possible to produce scatterers that are inhomogeneous with material properties that are functions of radius r, such as concentric shells. We demonstrate that with proper choice of material properties linked to the Hermite polynomials in r, scatterers can have long wavelength scattering behavior of higher powers: k8, k16, and higher. These ;Hermite scatterers; could be useful in providing unique signatures (or colors) to regions where they are present. If suspended in air under white light, the back-scattered spectrum would be shifted from blue towards violet and then ultraviolet as the higher order Hermite scatterers were illuminated.

CONFERENCE: Elastic and diffractive scattering

International Nuclear Information System (INIS)

White, Alan

1989-01-01

Elastic scattering, when particles appear to 'bounce' off each other, and the related phenomena of diffractive scattering are currently less fashionable than the study of hard scattering processes. However this could change rapidly if unexpected results from the UA4 experiment at the CERN Collider are confirmed and their implications tested. These questions were highlighted at the third 'Blois Workshop' on Elastic and Diffractive Scattering, held early in May on the Evanston campus of Northwestern University, near Chicago

Polyhydroxyalkanoate-based natural-synthetic hybrid copolymer films: A small-angle neutron scattering study

International Nuclear Information System (INIS)

Foster, L. John R.; Knott, Robert; Sanguanchaipaiwong, Vorapat; Holden, Peter J.

2006-01-01

Polyhydroxyalkanoates have attracted attention as biodegradable alternatives to conventional thermoplastics and as biomaterials. Through modification of their biosynthesis using Pseudomonas oleovorans, we have manipulated the material properties of these biopolyesters and produced a natural-synthetic hybrid copolymer of polyhydroxyoctanoate-block-diethylene glycol (PHO-b-DEG). A mixture of PHO and PHO-DEG were solvent cast from analytical grade chloroform and analysed using small-angle neutron scattering. A scattering pattern, easily distinguished above the background, was displayed by the films with a diffraction ring at q∼0.12 A -1 . This narrow ring of intensity is suggestive of a highly ordered system. Analysis of the diffraction pattern supported this concept and showed a d-spacing of approximately 50 A. In addition, conformation of the hybrid polymer chains can be manipulated to support their self-assembly into ordered microporous films

Minimum wall pressure coefficient of orifice plate energy dissipater

Directory of Open Access Journals (Sweden)

Wan-zheng Ai

2015-01-01

Full Text Available Orifice plate energy dissipaters have been successfully used in large-scale hydropower projects due to their simple structure, convenient construction procedure, and high energy dissipation ratio. The minimum wall pressure coefficient of an orifice plate can indirectly reflect its cavitation characteristics: the lower the minimum wall pressure coefficient is, the better the ability of the orifice plate to resist cavitation damage is. Thus, it is important to study the minimum wall pressure coefficient of the orifice plate. In this study, this coefficient and related parameters, such as the contraction ratio, defined as the ratio of the orifice plate diameter to the flood-discharging tunnel diameter; the relative thickness, defined as the ratio of the orifice plate thickness to the tunnel diameter; and the Reynolds number of the flow through the orifice plate, were theoretically analyzed, and their relationships were obtained through physical model experiments. It can be concluded that the minimum wall pressure coefficient is mainly dominated by the contraction ratio and relative thickness. The lower the contraction ratio and relative thickness are, the larger the minimum wall pressure coefficient is. The effects of the Reynolds number on the minimum wall pressure coefficient can be neglected when it is larger than 105. An empirical expression was presented to calculate the minimum wall pressure coefficient in this study.

A Monte Carlo evaluation of analytical multiple scattering corrections for unpolarised neutron scattering and polarisation analysis data

International Nuclear Information System (INIS)

Mayers, J.; Cywinski, R.

1985-03-01

Some of the approximations commonly used for the analytical estimation of multiple scattering corrections to thermal neutron elastic scattering data from cylindrical and plane slab samples have been tested using a Monte Carlo program. It is shown that the approximations are accurate for a wide range of sample geometries and scattering cross-sections. Neutron polarisation analysis provides the most stringent test of multiple scattering calculations as multiply scattered neutrons may be redistributed not only geometrically but also between the spin flip and non spin flip scattering channels. A very simple analytical technique for correcting for multiple scattering in neutron polarisation analysis has been tested using the Monte Carlo program and has been shown to work remarkably well in most circumstances. (author)

Decoupling single nanowire mobilities limited by surface scattering and bulk impurity scattering

International Nuclear Information System (INIS)

Khanal, D. R.; Levander, A. X.; Wu, J.; Yu, K. M.; Liliental-Weber, Z.; Walukiewicz, W.; Grandal, J.; Sanchez-Garcia, M. A.; Calleja, E.

2011-01-01

We demonstrate the isolation of two free carrier scattering mechanisms as a function of radial band bending in InN nanowires via universal mobility analysis, where effective carrier mobility is measured as a function of effective electric field in a nanowire field-effect transistor. Our results show that Coulomb scattering limits effective mobility at most effective fields, while surface roughness scattering only limits mobility under very high internal electric fields. High-energy α particle irradiation is used to vary the ionized donor concentration, and the observed decrease in mobility and increase in donor concentration are compared to Hall effect results of high-quality InN thin films. Our results show that for nanowires with relatively high doping and large diameters, controlling Coulomb scattering from ionized dopants should be given precedence over surface engineering when seeking to maximize nanowire mobility.

An empirical correction for moderate multiple scattering in super-heterodyne light scattering.

Science.gov (United States)

Botin, Denis; Mapa, Ludmila Marotta; Schweinfurth, Holger; Sieber, Bastian; Wittenberg, Christopher; Palberg, Thomas

2017-05-28

Frequency domain super-heterodyne laser light scattering is utilized in a low angle integral measurement configuration to determine flow and diffusion in charged sphere suspensions showing moderate to strong multiple scattering. We introduce an empirical correction to subtract the multiple scattering background and isolate the singly scattered light. We demonstrate the excellent feasibility of this simple approach for turbid suspensions of transmittance T ≥ 0.4. We study the particle concentration dependence of the electro-kinetic mobility in low salt aqueous suspension over an extended concentration regime and observe a maximum at intermediate concentrations. We further use our scheme for measurements of the self-diffusion coefficients in the fluid samples in the absence or presence of shear, as well as in polycrystalline samples during crystallization and coarsening. We discuss the scope and limits of our approach as well as possible future applications.

Scattering theory

CERN Document Server

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...

Scattered light characterization of FORTIS

Science.gov (United States)

McCandliss, Stephan R.; Carter, Anna; Redwine, Keith; Teste, Stephane; Pelton, Russell; Hagopian, John; Kutyrev, Alexander; Li, Mary J.; Moseley, S. Harvey

2017-08-01

We describe our efforts to build a Wide-Field Lyman alpha Geocoronal simulator (WFLaGs) for characterizing the end-to-end sensitivity of FORTIS (Far-UV Off Rowland-circle Telescope for Imaging and Spectroscopy) to scattered Lyman α emission from outside of the nominal (1/2 degree)2 field-of-view. WFLaGs is a 50 mm diameter F/1 aluminum parabolic collimator fed by a hollow cathode discharge lamp with a 80 mm clear MgF2 window housed in a vacuum skin. It creates emission over a 10 degree FOV. WFLaGS will allow us to validate and refine a recently developed scattered light model and verify our scatter light mitigation strategies, which will incorporate low scatter baffle materials, and possibly 3-d printed light traps, covering exposed scatter centers. We present measurements of scattering intensity of Lyman alpha as a function of angle with respect to the specular reflectance direction for several candidate baffle materials. Initial testing of WFLaGs will be described.

Imaging back scattered and near back scattered light in ignition scale plasmas

International Nuclear Information System (INIS)

Kirkwood, R.K.; Back, C.A.; Glenzer, S.H.; Moody, J.D.

1996-01-01

Diagnostics have been developed and fielded at the Nova laser facility that image scattered light in the vicinity of the final laser focusing lens. The absolute calibration of optical components exposed to the target debris have been achieved by a combination of routine in situ calibration and maintenance. The scattering observed from plasmas relevant to ignition experiments indicates that light scattered just outside the lens can be larger than that collected by the lens, and is a significant factor in the energy balance when the f number is high

Plane-dependent ML scatter scaling: 3D extension of the 2D simulated single scatter (SSS) estimate

Science.gov (United States)

Rezaei, Ahmadreza; Salvo, Koen; Vahle, Thomas; Panin, Vladimir; Casey, Michael; Boada, Fernando; Defrise, Michel; Nuyts, Johan

2017-08-01

Scatter correction is typically done using a simulation of the single scatter, which is then scaled to account for multiple scatters and other possible model mismatches. This scaling factor is determined by fitting the simulated scatter sinogram to the measured sinogram, using only counts measured along LORs that do not intersect the patient body, i.e. ‘scatter-tails’. Extending previous work, we propose to scale the scatter with a plane dependent factor, which is determined as an additional unknown in the maximum likelihood (ML) reconstructions, using counts in the entire sinogram rather than only the ‘scatter-tails’. The ML-scaled scatter estimates are validated using a Monte-Carlo simulation of a NEMA-like phantom, a phantom scan with typical contrast ratios of a 68Ga-PSMA scan, and 23 whole-body 18F-FDG patient scans. On average, we observe a 12.2% change in the total amount of tracer activity of the MLEM reconstructions of our whole-body patient database when the proposed ML scatter scales are used. Furthermore, reconstructions using the ML-scaled scatter estimates are found to eliminate the typical ‘halo’ artifacts that are often observed in the vicinity of high focal uptake regions.

Real or perceived impediments to minimum pricing of alcohol in Australia: public opinion, the industry and the law.

Science.gov (United States)

Chalmers, Jenny; Carragher, Natacha; Davoren, Sondra; O'Brien, Paula

2013-11-01

A burgeoning body of empirical evidence demonstrates that increases in the price of alcohol can reduce per capita alcohol consumption and harmful drinking. Taxes on alcohol can be raised to increase prices, but this strategy can be undermined if the industry absorbs the tax increase and cross-subsidises the price of one alcoholic beverage with other products. Such loss-leading strategies are not possible with minimum pricing. We argue that a minimum (or floor) price for alcohol should be used as a complement to alcohol taxation. Several jurisdictions have already introduced minimum pricing (e.g., Canada, Ukraine) and others are currently investigating pathways to introduce a floor price (e.g., Scotland). Tasked by the Australian government to examine the public interest case for a minimum price, Australia's peak preventative health agency recommended against setting one at the present time. The agency was concerned that there was insufficient Australian specific modelling evidence to make robust estimates of the net benefits. Nonetheless, its initial judgement was that it would be difficult for a minimum price to produce benefits for Australia at the national level. Whilst modelling evidence is certainly warranted to support the introduction of the policy, the development and uptake of policy is influenced by more than just empirical evidence. This article considers three potential impediments to minimum pricing: public opinion and misunderstandings or misgivings about the operation of a minimum price; the strength of alcohol industry objections and measures to undercut the minimum price through discounts and promotions; and legal obstacles including competition and trade law. The analysis of these factors is situated in an Australian context, but has salience internationally. Copyright © 2013 Elsevier B.V. All rights reserved.

Geometrical effects in X-mode scattering

International Nuclear Information System (INIS)

Bretz, N.

1986-10-01

One technique to extend microwave scattering as a probe of long wavelength density fluctuations in magnetically confined plasmas is to consider the launching and scattering of extraordinary (X-mode) waves nearly perpendicular to the field. When the incident frequency is less than the electron cyclotron frequency, this mode can penetrate beyond the ordinary mode cutoff at the plasma frequency and avoid significant distortions from density gradients typical of tokamak plasmas. In the more familiar case, where the incident and scattered waves are ordinary, the scattering is isotropic perpendicular to the field. However, because the X-mode polarization depends on the frequency ratios and the ray angle to the magnetic field, the coupling between the incident and scattered waves is complicated. This geometrical form factor must be unfolded from the observed scattering in order to interpret the scattering due to density fluctuations alone. The geometrical factor is calculated here for the special case of scattering perpendicular to the magnetic field. For frequencies above the ordinary mode cutoff the scattering is relatively isotropic, while below cutoff there are minima in the forward and backward directions which go to zero at approximately half the ordinary mode cutoff density

Three-dimensional imaging of flat natural and cultural heritage objects by a Compton scattering modality

Science.gov (United States)

Guerrero Prado, Patricio; Nguyen, Mai K.; Dumas, Laurent; Cohen, Serge X.

2017-01-01

Characterization and interpretation of flat ancient material objects, such as those found in archaeology, paleoenvironments, paleontology, and cultural heritage, have remained a challenging task to perform by means of conventional x-ray tomography methods due to their anisotropic morphology and flattened geometry. To overcome the limitations of the mentioned methodologies for such samples, an imaging modality based on Compton scattering is proposed in this work. Classical x-ray tomography treats Compton scattering data as noise in the image formation process, while in Compton scattering tomography the conditions are set such that Compton data become the principal image contrasting agent. Under these conditions, we are able, first, to avoid relative rotations between the sample and the imaging setup, and second, to obtain three-dimensional data even when the object is supported by a dense material by exploiting backscattered photons. Mathematically this problem is addressed by means of a conical Radon transform and its inversion. The image formation process and object reconstruction model are presented. The feasibility of this methodology is supported by numerical simulations.

Comprehensive study of the electron scattering mechanisms in 4H-SiC MOSFETs

Czech Academy of Sciences Publication Activity Database

Uhnevionak, V.; Burenkov, A.; Strenger, C.; Ortiz, G.; Bedel-Pereira, E.; Mortet, Vincent; Cristiano, F.; Bauer, A.J.; Pichler, P.

2015-01-01

Roč. 62, č. 8 (2015), s. 2562-2570 ISSN 0018-9383 Institutional support: RVO:68378271 Keywords : electron mobility * Hall effect * scattering mechanisms * SiC MOSFET Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.207, year: 2015

Neutron monitor latitude survey of cosmic ray intensity during the 1986/1987 solar minimum

International Nuclear Information System (INIS)

Moraal, H.; Potgieter, M.S.; Stoker, P.H.; van der Walt, A.J.

1989-01-01

A latitude survey of the cosmic ray intensity at sea level was conducted during the 1986/1987 solar minimum period on commercial vessels of the South African Marine Corporation (SAFMARINE). The results show that the differential response function for the 1986/1987 solar minimum agrees well with that measured in 1965. Both these response functions are significantly lower than those for 1976 and 1954. This result supports the 22-year modulation cycle as predicted, for example, by models including drift effects of the charged cosmic ray particles in the large-scale interplanetary magnetic field. A crossover of the spectra at rigidities of about 7 GV was also observed. Such a crossover is necessary to explain both the stationary neutron monitor counting rates and the lower-energy balloon and space observations in consecutive solar cycles. copyright American Geophysical Union 1989

Detection of explosives by neutron scattering

International Nuclear Information System (INIS)

Brooks, F.D.; Buffler, A.; Allie, M.S.; Nchodu, M.R.; Bharuth-Ram, K.

1998-01-01

For non-intrusive detection of hidden explosives or other contraband such as narcotics a fast neutron scattering analysis (FNSA) technique is proposed. An experimental arrangement uses a collimated, pulsed beam of neutrons directed at the sample. Scattered neutrons are detected by liquid scintillation counters at different scattering angles. A scattering signature is derived from two-parameter data, counts vs pulse height and time-of-flight measured for each element (H, C, N or O) at each of two scattering angles and two neutron energies. The elemental signatures are very distinctive and constitute a good response matrix for unfolding elemental components from the scattering signatures measured for different compounds

Λ scattering equations

Science.gov (United States)

Gomez, Humberto

2016-06-01

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 Λ 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 Λ 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 Λ algorithm.

Metagenomic analysis of size-fractionated picoplankton in a marine oxygen minimum zone

OpenAIRE

Ganesh, Sangita; Parris, Darren J; DeLong, Edward F; Stewart, Frank J

2013-01-01

Marine oxygen minimum zones (OMZs) support diverse microbial communities with roles in major elemental cycles. It is unclear how the taxonomic composition and metabolism of OMZ microorganisms vary between particle-associated and free-living size fractions. We used amplicon (16S rRNA gene) and shotgun metagenome sequencing to compare microbial communities from large (>1.6 μm) and small (0.2–1.6 μm) filter size fractions along a depth gradient in the OMZ off Chile. Despite steep vertical redox ...

Investigation of the core-halo structure of the neutron-rich nuclei {sup 6}He and {sup 8}He by intermediate-energy elastic proton scattering at high momentum transfer; Etude de la structure coeur-halo des noyaux riches en neutron {sup 6}He et {sup 8}He par la diffusion elastique de protons aux energies intermediaires etendue a la region du premier minimum de diffraction

Energy Technology Data Exchange (ETDEWEB)

Aksouh, F

2002-12-01

The elastic proton scattering from the halo nuclei {sup 6}He and {sup 8}He was investigated in inverse kinematics at energies around 700 MeV/u with the aim to deduce the differential cross sections for the region of high momentum transfer, covering the first diffraction minimum. For this purpose, a liquid-hydrogen target was specially developed and used for the first time allowing to obtain low-background data as compared to commonly used targets made from C-H compounds. Previous data taken in the region of small momentum transfer were sensitive to the size and the peripheral shape of the total nuclear matter density distribution but not to the inner part. The present data allow for a more detailed insight in the structure of the alike core in {sup 6,8}He through a better determination of the matter density distributions. Several density distributions calculated from different microscopic models were used to derive elastic scattering cross sections which are compared with the obtained data. (author)

Tunable output-frequency filter algorithm for imaging through scattering media under LED illumination

Science.gov (United States)

Zhou, Meiling; Singh, Alok Kumar; Pedrini, Giancarlo; Osten, Wolfgang; Min, Junwei; Yao, Baoli

2018-03-01

We present a tunable output-frequency filter (TOF) algorithm to reconstruct the object from noisy experimental data under low-power partially coherent illumination, such as LED, when imaging through scattering media. In the iterative algorithm, we employ Gaussian functions with different filter windows at different stages of iteration process to reduce corruption from experimental noise to search for a global minimum in the reconstruction. In comparison with the conventional iterative phase retrieval algorithm, we demonstrate that the proposed TOF algorithm achieves consistent and reliable reconstruction in the presence of experimental noise. Moreover, the spatial resolution and distinctive features are retained in the reconstruction since the filter is applied only to the region outside the object. The feasibility of the proposed method is proved by experimental results.

Assessment of capacity support and scattering in experimental high speed vehicle to vehicle MIMO links

DEFF Research Database (Denmark)

Eggers, Patrick Claus F.; Brown, Tim; Olesen, Kim

2007-01-01

Preliminary results on the use of the vehicle to vehicle MIMO channel in a rural highway environment are presented. This is looked at both in terms of the available spatial multiplexing through singular value decomposition and also angular distribution within the channel. Results indicate a strong...... predominant line of sight link in general while instances of scattering from other vehicles will cause changes in the Doppler spectrum as well as beamforming jitter....

Dispersion Decay and Scattering Theory

CERN Document Server

Komech, Alexander

2012-01-01

A simplified, yet rigorous treatment of scattering theory methods and their applications Dispersion Decay and Scattering Theory provides thorough, easy-to-understand guidance on the application of scattering theory methods to modern problems in mathematics, quantum physics, and mathematical physics. Introducing spectral methods with applications to dispersion time-decay and scattering theory, this book presents, for the first time, the Agmon-Jensen-Kato spectral theory for the Schr?dinger equation, extending the theory to the Klein-Gordon equation. The dispersion decay plays a crucial role i

High frequency and pulse scattering physical acoustics

CERN Document Server

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

76 FR 15368 - Minimum Security Devices and Procedures

Science.gov (United States)

2011-03-21

... DEPARTMENT OF THE TREASURY Office of Thrift Supervision Minimum Security Devices and Procedures... concerning the following information collection. Title of Proposal: Minimum Security Devices and Procedures... security devices and procedures to discourage robberies, burglaries, and larcenies, and to assist in the...

Operational forecasting of daily temperatures in the Valencia Region. Part II: minimum temperatures in winter.

Science.gov (United States)

Gómez, I.; Estrela, M.

2009-09-01

Extreme temperature events have a great impact on human society. Knowledge of minimum temperatures during winter is very useful for both the general public and organisations whose workers have to operate in the open, e.g. railways, roadways, tourism, etc. Moreover, winter minimum temperatures are considered a parameter of interest and concern since persistent cold-waves can affect areas as diverse as public health, energy consumption, etc. Thus, an accurate forecasting of these temperatures could help to predict cold-wave conditions and permit the implementation of strategies aimed at minimizing the negative effects that low temperatures have on human health. The aim of this work is to evaluate the skill of the RAMS model in determining daily minimum temperatures during winter over the Valencia Region. For this, we have used the real-time configuration of this model currently running at the CEAM Foundation. To carry out the model verification process, we have analysed not only the global behaviour of the model for the whole Valencia Region, but also its behaviour for the individual stations distributed within this area. The study has been performed for the winter forecast period from 1 December 2007 - 31 March 2008. The results obtained are encouraging and indicate a good agreement between the observed and simulated minimum temperatures. Moreover, the model captures quite well the temperatures in the extreme cold episodes. Acknowledgement. This work was supported by "GRACCIE" (CSD2007-00067, Programa Consolider-Ingenio 2010), by the Spanish Ministerio de Educación y Ciencia, contract number CGL2005-03386/CLI, and by the Regional Government of Valencia Conselleria de Sanitat, contract "Simulación de las olas de calor e invasiones de frío y su regionalización en la Comunidad Valenciana" ("Heat wave and cold invasion simulation and their regionalization at Valencia Region"). The CEAM Foundation is supported by the Generalitat Valenciana and BANCAIXA (Valencia

Scatter from optical components

International Nuclear Information System (INIS)

Stover, J.C.

1989-01-01

This book is covered under the following topics: measurement and analysis techniques; BRDF standards, comparisons, and anomalies; scatter measurement of several materials; scatter from contaminations; and optical system contamination: effects, measurement, and control

Crossover from incoherent to coherent phonon scattering in epitaxial oxide superlattices.

Science.gov (United States)

Ravichandran, Jayakanth; Yadav, Ajay K; Cheaito, Ramez; Rossen, Pim B; Soukiassian, Arsen; Suresha, S J; Duda, John C; Foley, Brian M; Lee, Che-Hui; Zhu, Ye; Lichtenberger, Arthur W; Moore, Joel E; Muller, David A; Schlom, Darrell G; Hopkins, Patrick E; Majumdar, Arun; Ramesh, Ramamoorthy; Zurbuchen, Mark A

2014-02-01

Elementary particles such as electrons or photons are frequent subjects of wave-nature-driven investigations, unlike collective excitations such as phonons. The demonstration of wave-particle crossover, in terms of macroscopic properties, is crucial to the understanding and application of the wave behaviour of matter. We present an unambiguous demonstration of the theoretically predicted crossover from diffuse (particle-like) to specular (wave-like) phonon scattering in epitaxial oxide superlattices, manifested by a minimum in lattice thermal conductivity as a function of interface density. We do so by synthesizing superlattices of electrically insulating perovskite oxides and systematically varying the interface density, with unit-cell precision, using two different epitaxial-growth techniques. These observations open up opportunities for studies on the wave nature of phonons, particularly phonon interference effects, using oxide superlattices as model systems, with extensive applications in thermoelectrics and thermal management.

Study of the structure of the Hoyle state by refractive α-scattering

Directory of Open Access Journals (Sweden)

Goncharov S.A.

2014-03-01

Full Text Available α + 12C elastic and inelastic to the Hoyle state (0+2, 7.65 MeV differential cross-sections were measured at the energies 60 and 65 MeV with the aim of testing the microscopic wave function [1] widely used in modern structure calculations of 12C. Deep rainbow (Airy minima were observed in all four curves. The minima in the inelastic angular distributions are shifted to the larger angles relatively those in the elastic ones, which testify the radius enhancement of the Hoyle state. In general, the DWBA calculations failed to reproduce the details of the cross sections in the region of therainbow minima in the inelastic scattering data. However, by using the phenomenological density with rms radius equal 2.9 fm, we can reproduce the Airy minimum positions.

Visualizing One-Dimensional Electronic States and their Scattering in Semi-conducting Nanowires

Science.gov (United States)

Beidenkopf, Haim; Reiner, Jonathan; Norris, Andrew; Nayak, Abhay Kumar; Avraham, Nurit; Shtrikman, Hadas

One-dimensional electronic systems constitute a fascinating playground for the emergence of exotic electronic effects and phases, within and beyond the Tomonaga-Luttinger liquid paradigm. More recently topological superconductivity and Majorana modes were added to that long list of phenomena. We report scanning tunneling microscopy and spectroscopy measurements conducted on pristine, epitaxialy grown InAs nanowires. We resolve the 1D electronic band structure manifested both via Van-Hove singularities in the local density-of-states, as well as by the quasi-particle interference patterns, induced by scattering from surface impurities. By studying the scattering of the one-dimensional electronic states off various scatterers, including crystallographic defects and the nanowire end, we identify new one-dimensional relaxation regimes and yet unexplored effects of interactions. Some of these may bear implications on the topological superconducting state and Majorana modes therein. The authors acknowledge support from the Israeli Science Foundation (ISF).

Ultra-small-angle X-ray scattering characterization of diesel/gasoline soot: sizes and particle-packing conditions

Science.gov (United States)

Kameya, Yuki; Lee, Kyeong O.

2013-10-01

Regulations on particulate emissions from internal combustion engines tend to become more stringent, accordingly the importance of particulate filters in the after-treatment system has been increasing. In this work, the applicability of ultra-small-angle X-ray scattering (USAXS) to diesel soot cake and gasoline soot was investigated. Gasoline-direct-injection engine soot was collected at different fuel injection timings. The unified fits method was applied to analyze the resultant scattering curves. The validity of analysis was supported by comparing with carbon black and taking the sample images using a transmission electron microscope, which revealed that the primary particle size ranged from 20 to 55 nm. In addition, the effects of particle-packing conditions on the USAXS measurement were demonstrated by using samples suspended in acetone. Then, the investigation was extended to characterization of diesel soot cake deposited on a diesel particulate filter (DPF). Diesel soot was trapped on a small piece of DPF at different deposition conditions which were specified using the Peclet number. The dependence of scattering curve on soot-deposition conditions was demonstrated. To support the interpretation of the USAXS results, soot cake samples were observed using a scanning electron microscope and the influence of particle-packing conditions on scattering curve was discussed.

Ultra-small-angle X-ray scattering characterization of diesel/gasoline soot: sizes and particle-packing conditions

International Nuclear Information System (INIS)

Kameya, Yuki; Lee, Kyeong O.

2013-01-01

Regulations on particulate emissions from internal combustion engines tend to become more stringent, accordingly the importance of particulate filters in the after-treatment system has been increasing. In this work, the applicability of ultra-small-angle X-ray scattering (USAXS) to diesel soot cake and gasoline soot was investigated. Gasoline-direct-injection engine soot was collected at different fuel injection timings. The unified fits method was applied to analyze the resultant scattering curves. The validity of analysis was supported by comparing with carbon black and taking the sample images using a transmission electron microscope, which revealed that the primary particle size ranged from 20 to 55 nm. In addition, the effects of particle-packing conditions on the USAXS measurement were demonstrated by using samples suspended in acetone. Then, the investigation was extended to characterization of diesel soot cake deposited on a diesel particulate filter (DPF). Diesel soot was trapped on a small piece of DPF at different deposition conditions which were specified using the Peclet number. The dependence of scattering curve on soot-deposition conditions was demonstrated. To support the interpretation of the USAXS results, soot cake samples were observed using a scanning electron microscope and the influence of particle-packing conditions on scattering curve was discussed

Ultra-small-angle X-ray scattering characterization of diesel/gasoline soot: sizes and particle-packing conditions

Energy Technology Data Exchange (ETDEWEB)

Kameya, Yuki, E-mail: ykameya@anl.gov; Lee, Kyeong O. [Argonne National Laboratory, Center for Transportation Research (United States)

2013-10-15

Regulations on particulate emissions from internal combustion engines tend to become more stringent, accordingly the importance of particulate filters in the after-treatment system has been increasing. In this work, the applicability of ultra-small-angle X-ray scattering (USAXS) to diesel soot cake and gasoline soot was investigated. Gasoline-direct-injection engine soot was collected at different fuel injection timings. The unified fits method was applied to analyze the resultant scattering curves. The validity of analysis was supported by comparing with carbon black and taking the sample images using a transmission electron microscope, which revealed that the primary particle size ranged from 20 to 55 nm. In addition, the effects of particle-packing conditions on the USAXS measurement were demonstrated by using samples suspended in acetone. Then, the investigation was extended to characterization of diesel soot cake deposited on a diesel particulate filter (DPF). Diesel soot was trapped on a small piece of DPF at different deposition conditions which were specified using the Peclet number. The dependence of scattering curve on soot-deposition conditions was demonstrated. To support the interpretation of the USAXS results, soot cake samples were observed using a scanning electron microscope and the influence of particle-packing conditions on scattering curve was discussed.

Hadron transverse momentum distributions in muon deep inelastic scattering at 160 GeV/c

Czech Academy of Sciences Publication Activity Database

Adolph, C.; Alekseev, M.; Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Austregisilio, A.; Badelek, B.; Balestra, F.; Barth, J.; Baum, G.; Bedfer, Y.; Berlin, A.; Bernhard, J.; Bertini, R.; Bicker, K.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bravar, A.; Bressan, A.; Büchele, M.; Burtin, E.; Capozza, L.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Crespo, M.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Denisov, O.; Donskov, S.; Doshita, N.; Duic, V.; Dünnweber, W.; Dziewiecki, M.; Efremov, A.V.; Elia, C.; Eversheim, P.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; Finger jr., M.; Fischer, H.; Franco, C.; Fresne von Hohenesche, N.; Friedrich, J.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gnesi, I.; Gobbo, B.; Goertz, S.; Grabmüller, S.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Guthörl, T.; Haas, F.; von Harrach, D.; Heinsius, F.; Herrmann, F.; Hess, C.; Hinterberger, F.; Horikawa, N.; Höppner, Ch.; d'Hose, N.; Huber, S.; Ishimoto, S.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Joosten, R.; Kabuss, E.; Kang, D.; Ketzer, B.; Khaustov, G.; Khokhlov, Y.; Kisselev, Y.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.; Kolosov, V.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V.; Kotzinian, A.; Kouznetsov, O.; Krämer, M.; Kroumchtein, Z.; Kuchinski, N.; Kunne, F.; Kurek, K.; Kurjata, R. P.; Lednev, A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G.; Mann, A.; Marchand, C.; Martin, A.; Marzec, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Y.; Morreale, A.; Nagaytsev, A.; Nagel, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.; Nový, J.; Nowak, W. D.; Nunes, A.S.; Olshevsky, A.; Ostrick, M.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.; Pretz, J.; Quaresma, M.; Quintans, C.; Rajotte, J.; Ramos, S.; Reicherz, G.; Rocco, E.; Rodionov, V. K.; Rondio, E.; Rossiyskaya, N. S.; Ryabchikov, D.; Samoylenko, V.; Sandacz, A.; Sapozhnikov, M.; Sarkar, S.; Savin, I.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schlütter, T.; Schmidt, A.; Schmidt, K.; Schmiden, H.; Schmitt, L.; Schönning, K.; Schopferer, S.; Schott, M.; Shevchenko, O.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sosio, S.; Sozzi, F.; Srnka, Aleš; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Sznajder, P.; Takekawa, S.; Ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Uhl, S.; Uman, I.; Vandenbroucke, M.; Virius, M.; Wang, L.; Weisrock, T.; Wilfert, M.; Windmolders, R.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Zhuravlev, N.; Ziembicki, M.

2013-01-01

Roč. 73, č. 8 (2013), 2531:1-15 ISSN 1434-6044 Institutional support: RVO:68081731 Keywords : hadron * inelastic scattering Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 5.436, year: 2013

Time-reversal of electromagnetic scattering for small scatterer classification

International Nuclear Information System (INIS)

Smith, J Torquil; Berryman, James G

2012-01-01

Time-reversal operators, or the alternatively labelled, but equivalent, multistatic response matrix methods, are used to show how to determine the number of scatterers present in an electromagnetic scattering scenario that might be typical of UneXploded Ordinance (UXO) detection, classification and removal applications. Because the nature of the target UXO application differs from that of many other common inversion problems, emphasis is placed here on classification and enumeration rather than on detailed imaging. The main technical issues necessarily revolve around showing that it is possible to find a sufficient number of constraints via multiple measurements (i.e. using several distinct views at the target site) to solve the enumeration problem. The main results show that five measurements with antenna pairs are generally adequate to solve the classification and enumeration problems. However, these results also demonstrate a need for decreasing noise levels in the multistatic matrix as the number n of scatterers increases for the intended practical applications of the method. (paper)

Light scattering by small particles

CERN Document Server

Hulst, H C van de

1981-01-01

""A must for researchers using the techniques of light scattering."" ? S. C. Snowdon, Journal of the Franklin InstituteThe measurement of light scattering of independent, homogeneous particles has many useful applications in physical chemistry, meteorology and astronomy. There is, however, a sizeable gap between the abstract formulae related to electromagnetic-wave-scattering phenomena, and the computation of reliable figures and curves. Dr. van de Hulst's book enables researchers to bridge that gap. The product of twelve years of work, it is an exhaustive study of light-scattering properties

Applied electromagnetic scattering theory

CERN Document Server

Osipov, Andrey A

2017-01-01

Besides classical applications (radar and stealth, antennas, microwave engineering), scattering and diffraction are enabling phenomena for some emerging research fields (artificial electromagnetic materials or metamaterials, terahertz technologies, electromagnetic aspects of nano-science). This book is a tutorial for advanced students who need to study diffraction theory. The textbook gives fundamental knowledge about scattering and diffraction of electromagnetic waves and provides some working examples of solutions for practical high-frequency scattering and diffraction problems. The book focuses on the most important diffraction effects and mechanisms influencing the scattering process and describes efficient and physically justified simulation methods - physical optics (PO) and the physical theory of diffraction (PTD) - applicable in typical remote sensing scenarios. The material is presented in a comprehensible and logical form, which relates the presented results to the basic principles of electromag...

Chaotic scattering and quantum dynamics

International Nuclear Information System (INIS)

Doron, Eyal.

1992-11-01

The main concern of this thesis is the application of the semiclassical approximation to quantum chaotic scattering systems. We deal with two separate, although interconnected, subjects. The first subject dealt with is the semiclassical characterization of the fluctuations of the S matrix. A particular important parameter is the magnetic field B, and we show how the correlation length and line shape of S matrix elements under a change of B may be derived. An effect which is present in many physical wave systems is absorption of energy flux. We show how absorption affects both the reflectivity and the scattering phase and time delay of a scattering system. In the second part of the thesis, we show how the formalism and results obtained from chaotic scattering can be applied to the investigation of closed chaotic systems, and in particular to chaotic billiards. The semiclassical expansion for billiards is presented. In the last part of the thesis we deal with the statistics of S matrices of chaotic scattering systems. The main message of this work is that scattering matrix, and its classical counterpart the Poincare Scattering Map can be used to yield a powerful formulation of the quantum mechanical dynamics of bounded systems. (author)

Effect of multiple scattering on lidar measurements

International Nuclear Information System (INIS)

Cohen, A.

1977-01-01

The lidar equation in its standard form involves the assumption that the scattered irradiance reaching the lidar receiver has been only singly scattered. However, in the cases of scattering from clouds and thick aerosol layers, it is shown that multiple scattering cannot be neglected. An experimental method for the detection of multiple scattering by depolarization measurement techniques is discussed. One method of theoretical calculations of double-scattering is presented and discussed

Two-magnon Raman scattering in LiMnPO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Calderon Filho, C.J. [Instituto de Física ”Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo (Brazil); Gomes, P.F. [Instituto de Física ”Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo (Brazil); Universidade Federal de Goiás, 75801-615, Jataí, Goiás (Brazil); García-Flores, A.F.; Barberis, G.E. [Instituto de Física ”Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo (Brazil); Granado, E., E-mail: egranado@ifi.unicamp.br [Instituto de Física ”Gleb Wataghin”, UNICAMP, 13083-859, Campinas, São Paulo (Brazil)

2015-03-01

Two-magnon Raman scattering is observed in the orthophosphate LiMnPO{sub 4}, carrying quantitative information on the magnetic interactions between local Mn{sup 2+} moments. A simulated annealing fitting procedure of the Raman signal to theoretical curves derived from a magnetic Hamiltonian was carried out, taking exchange and anisotropy constants as free fitting parameters. Previously reported inelastic neutron scattering (INS) data [J. Li et al., Phys. Rev. B 79, 144410 (2009)] were also used in the fit. It is shown that the combined application of INS and Raman scattering data in the fit reduces the ambiguity of the determined set of exchange parameters with respect to fitting procedures using INS or Raman data independently. The temperature dependence of the Raman signal does not show a collapse of the two-magnon excitations at the long-range magnetic ordering temperature, T{sub N}=34K, supporting significant short-range spin correlations above T{sub N}. - Highlights: • A two-magnon Raman scattering signal was observed in the orthophosphate LiMnPO{sub 4}. • Calculations under the Fleury–Loudon were carried out to simulate the observed signal. • A combined fit using Raman and neutron data yields a robust set of magnetic parameters. • The nearest-neighbor interaction is largely dominant over the remaining terms. • This work is a step forward in combining techniques to obtain exchange constants.

76 FR 30243 - Minimum Security Devices and Procedures

Science.gov (United States)

2011-05-24

... DEPARTMENT OF THE TREASURY Office of Thrift Supervision Minimum Security Devices and Procedures.... Title of Proposal: Minimum Security Devices and Procedures. OMB Number: 1550-0062. Form Number: N/A... respect to the installation, maintenance, and operation of security devices and procedures to discourage...

Elastic scattering of low-energy electrons with Sr atoms

International Nuclear Information System (INIS)

Yuan, J.; Zhang, Z.; Wan, H.

1990-01-01

Static-exchange, plus correlation-polarization-potential calculations are performed for elastic low-energy electron scattering from Sr atoms while paying attention to the low-lying shape resonances. The correlation potential is calculated both with and without a scaling factor. A 2 D-shape resonance is produced at 1.0 eV with a parameter-free, and at 1.25 eV with a scaled, correlation potential. No 2 P-shape resonances are predicted, but evidence to support the existence of a stable negative ion Sr - in the 5s 2 5p electron configuration is given from the viewpoint of electron scattering. The bound energy of the extra electron in the negative ion is estimated by transforming the phase shift of the corresponding partial wave into the polarization quantum-defect number and extrapolating the number from positive to negative energies

Support for User Interfaces for Distributed Systems

Science.gov (United States)

Eychaner, Glenn; Niessner, Albert

2005-01-01

An extensible Java(TradeMark) software framework supports the construction and operation of graphical user interfaces (GUIs) for distributed computing systems typified by ground control systems that send commands to, and receive telemetric data from, spacecraft. Heretofore, such GUIs have been custom built for each new system at considerable expense. In contrast, the present framework affords generic capabilities that can be shared by different distributed systems. Dynamic class loading, reflection, and other run-time capabilities of the Java language and JavaBeans component architecture enable the creation of a GUI for each new distributed computing system with a minimum of custom effort. By use of this framework, GUI components in control panels and menus can send commands to a particular distributed system with a minimum of system-specific code. The framework receives, decodes, processes, and displays telemetry data; custom telemetry data handling can be added for a particular system. The framework supports saving and later restoration of users configurations of control panels and telemetry displays with a minimum of effort in writing system-specific code. GUIs constructed within this framework can be deployed in any operating system with a Java run-time environment, without recompilation or code changes.

Does increasing the minimum wage reduce poverty in developing countries?

OpenAIRE

Gindling, T. H.

2014-01-01

Do minimum wage policies reduce poverty in developing countries? It depends. Raising the minimum wage could increase or decrease poverty, depending on labor market characteristics. Minimum wages target formal sector workers—a minority of workers in most developing countries—many of whom do not live in poor households. Whether raising minimum wages reduces poverty depends not only on whether formal sector workers lose jobs as a result, but also on whether low-wage workers live in poor househol...

Neutron scattering-instrumentation at the upgraded research reactor BER II

International Nuclear Information System (INIS)

1991-01-01

The Berlin Neutron Scattering Centre (BENSC) is a newly created special department of the Hahn-Meitner-Institut, in the framework of which the BER II neutron beam reactor is made available to external users. BENSC is devoted to development, continuous modernisation and maintenance of the scientific instrumets at the BER II and to the support of their users. (orig./HSI)

Electric field measurement in an atmospheric or higher pressure gas by coherent Raman scattering of nitrogen

International Nuclear Information System (INIS)

Ito, Tsuyohito; Kobayashi, Kazunobu; Hamaguchi, Satoshi; Mueller, Sarah; Luggenhoelscher, Dirk; Czarnetzki, Uwe

2009-01-01

The feasibility of electric field measurement based on field-induced coherent Raman scattering is demonstrated for the first time in a nitrogen containing gas at atmospheric or higher pressure, including open air. The technique is especially useful for the determination of temporal and spatial profiles of the electric field in air-based microdischarges, where nitrogen is abundant. In our current experimental setup, the minimum detectable field strength in open air is about 100 V mm -1 , which is sufficiently small compared with the average field present in typical microdischarges. No further knowledge of other gas/plasma parameters such as the nitrogen density is required. (fast track communication)

Controlled light scattering in transparent polycrystalline ferroelectrics

International Nuclear Information System (INIS)

Vasilevskaya, A.S.; Grodnenskij, I.M.; Sonin, A.S.

1977-01-01

Scattering indicatrices, birefringence, attenuation factor and time characteristics of the light scattering effect have been investigated in a polycrystal solid solution of Pbsub(0.92)Lasub(0.08)(Zrsub(0.65)Tisub(0.35))Osub(3) with the crystallite dimension 4-5 μm. The measurements have been taken for longitudinal and transverse scattering effects in the visible range of spectrum in the temperature range 20-200 deg C. The time characteristics of the scattering effect have been found to be significantly different when a sample transfers from a thermally depolarized state to an electrically polarized one and from an electrically polarized state to an electrically depolarized one. The shape of the scattering indicatrices depends on the polarization state of a sample. The distribution of the scattered light intensity in the part of the indicatrix characterizing the fundamental scattering is satisfactorily described by the Rayleigh-Hans theory. The diameter of scattering centres responsible for the scattering has been determined to be 6-7 μm. The experimental data show that there are different types of scattering centres, in the material. The fundamental scattering is caused by centres arising irreversibly during initial polarization of the sample. The second type of centres is responsible for the controlled part of scattering during repolarization

The SME gauge sector with minimum length

Science.gov (United States)

Belich, H.; Louzada, H. L. C.

2017-12-01

We study the gauge sector of the Standard Model Extension (SME) with the Lorentz covariant deformed Heisenberg algebra associated to the minimum length. In order to find and estimate corrections, we clarify whether the violation of Lorentz symmetry and the existence of a minimum length are independent phenomena or are, in some way, related. With this goal, we analyze the dispersion relations of this theory.

The SME gauge sector with minimum length

Energy Technology Data Exchange (ETDEWEB)

Belich, H.; Louzada, H.L.C. [Universidade Federal do Espirito Santo, Departamento de Fisica e Quimica, Vitoria, ES (Brazil)

2017-12-15

We study the gauge sector of the Standard Model Extension (SME) with the Lorentz covariant deformed Heisenberg algebra associated to the minimum length. In order to find and estimate corrections, we clarify whether the violation of Lorentz symmetry and the existence of a minimum length are independent phenomena or are, in some way, related. With this goal, we analyze the dispersion relations of this theory. (orig.)

Akibat Hukum Bagi Bank Bila Kewajiban Modal Inti Minimum Tidak Terpenuhi

Directory of Open Access Journals (Sweden)

Indira Retno Aryatie

2012-02-01

Full Text Available As an implementation of the Indonesian Banking Architecture policy, the government issues Bank Indonesia Regulation No. 9/16/ PBI/2007 on Minimum Tier One Capital that increases the minimum capital to 100 billion rupiah. This writing discusses the legal complication that a bank will face should it fail to fulfil the minimum ratio. Sebagai tindak lanjut dari kebijakan Arsitektur Perbankan Indonesia, pemerintah mengeluarkan Peraturan Bank Indonesia 9/16/PBI/2007 tentang Kewajiban Modal Inti Minimum Bank yang menaikkan modal inti minimum bank umum menjadi 100 miliar rupiah. Tulisan ini membahas akibat hukum yang akan dialami bank bila kewajiban modal minimum tersebut gagal dipenuhi.

The impact of minimum wage adjustments on Vietnamese wage inequality

DEFF Research Database (Denmark)

Hansen, Henrik; Rand, John; Torm, Nina

Using Vietnamese Labour Force Survey data we analyse the impact of minimum wage changes on wage inequality. Minimum wages serve to reduce local wage inequality in the formal sectors by decreasing the gap between the median wages and the lower tail of the local wage distributions. In contrast, local...... wage inequality is increased in the informal sectors. Overall, the minimum wages decrease national wage inequality. Our estimates indicate a decrease in the wage distribution Gini coefficient of about 2 percentage points and an increase in the 10/50 wage ratio of 5-7 percentage points caused...... by the adjustment of the minimum wages from 2011to 2012 that levelled the minimum wage across economic sectors....

Progresses in the measurement and evaluation of small-angle x-ray scattering data

International Nuclear Information System (INIS)

Bergmann, A.

2000-08-01

Scattering methods are a widely used technique for determining size and shape of particles in the mesoscopic size range. This work deals on the one hand with the development of instruments in the field of Small Angle x-ray Scattering (SAXS) and on the other hand with methodical contributions concerning the interpretation of small angle scattering data. After a short introduction about Small Angle Scattering (SAS) and its application in chapter one, follows in chapter two a derivation of the theory of Small Angle x-ray scattering. Thereafter indirect transformations (Generalized Indirect Fourier Transformation [GIFT], Indirect Fourier Transformation [IFT]) are discussed and in this connection the optimization of multidimensional hyper surfaces is described. There are different possibilities for optimizing such multidimensional surfaces. The pros and contras of the different optimization methods with respect to the evaluation of small angle scattering data from interacting systems are discussed in detail. Global optimization methods are mainly used, if the hypersurface, which has to be optimized, shows many local minima. The goal of the optimization is it to find the global minimum. It is essential, that the parameters of the hyper surface are independent of each other, as it is the case in the GIFT. If someone deals with problems in only few dimensions or with many boundary conditions, mostly local optimization routines are sufficient. Therefore a number of starting parameters for the optimization is chosen, which can be obtained systematically or randomly. The best solution obtained represents the result of the optimization procedure. Chapter 3 deals with the description of instruments used in the field of Small Angle x-ray Scattering. After a description of the components (x-ray sources, monochromators, detectors) of these instruments, the different beam geometries are discussed. In chapter 4 improvements of SAXS measurements on Kratky slit systems by Goebel

Risk control and the minimum significant risk

International Nuclear Information System (INIS)

Seiler, F.A.; Alvarez, J.L.

1996-01-01

Risk management implies that the risk manager can, by his actions, exercise at least a modicum of control over the risk in question. In the terminology of control theory, a management action is a control signal imposed as feedback on the system to bring about a desired change in the state of the system. In the terminology of risk management, an action is taken to bring a predicted risk to lower values. Even if it is assumed that the management action taken is 100% effective and that the projected risk reduction is infinitely well known, there is a lower limit to the desired effects that can be achieved. It is based on the fact that all risks, such as the incidence of cancer, exhibit a degree of variability due to a number of extraneous factors such as age at exposure, sex, location, and some lifestyle parameters such as smoking or the consumption of alcohol. If the control signal is much smaller than the variability of the risk, the signal is lost in the noise and control is lost. This defines a minimum controllable risk based on the variability of the risk over the population considered. This quantity is the counterpart of the minimum significant risk which is defined by the uncertainties of the risk model. Both the minimum controllable risk and the minimum significant risk are evaluated for radiation carcinogenesis and are shown to be of the same order of magnitude. For a realistic management action, the assumptions of perfectly effective action and perfect model prediction made above have to be dropped, resulting in an effective minimum controllable risk which is determined by both risk limits. Any action below that effective limit is futile, but it is also unethical due to the ethical requirement of doing more good than harm. Finally, some implications of the effective minimum controllable risk on the use of the ALARA principle and on the evaluation of remedial action goals are presented

Scattering Of Nonplanar Acoustic Waves

Science.gov (United States)

Gillman, Judith M.; Farassat, F.; Myers, M. K.

1995-01-01

Report presents theoretical study of scattering of nonplanar acoustic waves by rigid bodies. Study performed as part of effort to develop means of predicting scattering, from aircraft fuselages, of noise made by rotating blades. Basic approach was to model acoustic scattering by use of boundary integral equation to solve equation by the Galerkin method.

Electron scattering for exotic nuclei

Indian Academy of Sciences (India)

2014-11-04

Nov 4, 2014 ... A brand-new electron scattering facility, the SCRIT Electron Scattering Facility, will soon start its operation at RIKEN RI Beam Factory, Japan. This is the world's first electron scattering facility dedicated to the structure studies of short-lived nuclei. The goal of this facility is to determine the charge density ...

Pion-pion scattering

International Nuclear Information System (INIS)

Kuehnelt, H.

1975-01-01

We discuss a few properties of scattering amplitudes proved within the framework of the field theory and their significance in the derivation of quantitative statements. The state of the boundaries for the scattering lengths is to be especially discussed as well as the question as to how far it is possible to exclude various solutions from phase displacement analyses. (orig./LH) [de

The minimum information about a genome sequence (MIGS) specification

Science.gov (United States)

Field, Dawn; Garrity, George; Gray, Tanya; Morrison, Norman; Selengut, Jeremy; Sterk, Peter; Tatusova, Tatiana; Thomson, Nicholas; Allen, Michael J; Angiuoli, Samuel V; Ashburner, Michael; Axelrod, Nelson; Baldauf, Sandra; Ballard, Stuart; Boore, Jeffrey; Cochrane, Guy; Cole, James; Dawyndt, Peter; De Vos, Paul; dePamphilis, Claude; Edwards, Robert; Faruque, Nadeem; Feldman, Robert; Gilbert, Jack; Gilna, Paul; Glöckner, Frank Oliver; Goldstein, Philip; Guralnick, Robert; Haft, Dan; Hancock, David; Hermjakob, Henning; Hertz-Fowler, Christiane; Hugenholtz, Phil; Joint, Ian; Kagan, Leonid; Kane, Matthew; Kennedy, Jessie; Kowalchuk, George; Kottmann, Renzo; Kolker, Eugene; Kravitz, Saul; Kyrpides, Nikos; Leebens-Mack, Jim; Lewis, Suzanna E; Li, Kelvin; Lister, Allyson L; Lord, Phillip; Maltsev, Natalia; Markowitz, Victor; Martiny, Jennifer; Methe, Barbara; Mizrachi, Ilene; Moxon, Richard; Nelson, Karen; Parkhill, Julian; Proctor, Lita; White, Owen; Sansone, Susanna-Assunta; Spiers, Andrew; Stevens, Robert; Swift, Paul; Taylor, Chris; Tateno, Yoshio; Tett, Adrian; Turner, Sarah; Ussery, David; Vaughan, Bob; Ward, Naomi; Whetzel, Trish; Gil, Ingio San; Wilson, Gareth; Wipat, Anil

2008-01-01

With the quantity of genomic data increasing at an exponential rate, it is imperative that these data be captured electronically, in a standard format. Standardization activities must proceed within the auspices of open-access and international working bodies. To tackle the issues surrounding the development of better descriptions of genomic investigations, we have formed the Genomic Standards Consortium (GSC). Here, we introduce the minimum information about a genome sequence (MIGS) specification with the intent of promoting participation in its development and discussing the resources that will be required to develop improved mechanisms of metadata capture and exchange. As part of its wider goals, the GSC also supports improving the ‘transparency’ of the information contained in existing genomic databases. PMID:18464787

Wind Turbine Down-regulation Strategy for Minimum Wake Deficit

DEFF Research Database (Denmark)

Ma, Kuichao; Zhu, Jiangsheng; N. Soltani, Mohsen

2017-01-01

Down-regulation mode of wind turbine is commonly used no matter for the reserve power for supporting ancillary service to the grid, power optimization in wind farm or reducing power loss in the fault condition. It is also a method to protect faulty turbine. A down-regulation strategy based...... on minimum wake deficit is proposed in this paper, for the power improvement of the downwind turbine in low and medium wind speed region. The main idea is to operate turbine work at an appropriate operating point through rotor speed and torque control. The effectiveness of the strategy is verified...... by comparing with maximum rotor speed strategy. The result shows that the proposed strategy can improve the power of downwind turbine effectively....

42 CFR 84.197 - Respirator containers; minimum requirements.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.197... Cartridge Respirators § 84.197 Respirator containers; minimum requirements. Respirators shall be equipped with a substantial, durable container bearing markings which show the applicant's name, the type and...

42 CFR 84.174 - Respirator containers; minimum requirements.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.174... Air-Purifying Particulate Respirators § 84.174 Respirator containers; minimum requirements. (a) Except..., durable container bearing markings which show the applicant's name, the type of respirator it contains...

A full-angle Monte-Carlo scattering technique including cumulative and single-event Rutherford scattering in plasmas

Science.gov (United States)

Higginson, Drew P.

2017-11-01

We describe and justify a full-angle scattering (FAS) method to faithfully reproduce the accumulated differential angular Rutherford scattering probability distribution function (pdf) of particles in a plasma. The FAS method splits the scattering events into two regions. At small angles it is described by cumulative scattering events resulting, via the central limit theorem, in a Gaussian-like pdf; at larger angles it is described by single-event scatters and retains a pdf that follows the form of the Rutherford differential cross-section. The FAS method is verified using discrete Monte-Carlo scattering simulations run at small timesteps to include each individual scattering event. We identify the FAS regime of interest as where the ratio of temporal/spatial scale-of-interest to slowing-down time/length is from 10-3 to 0.3-0.7; the upper limit corresponds to Coulomb logarithm of 20-2, respectively. Two test problems, high-velocity interpenetrating plasma flows and keV-temperature ion equilibration, are used to highlight systems where including FAS is important to capture relevant physics.

Design of a minimum emittance nBA lattice

Science.gov (United States)

Lee, S. Y.

1998-04-01

An attempt to design a minimum emittance n-bend achromat (nBA) lattice has been made. One distinct feature is that dipoles with two different lengths were used. As a multiple bend achromat, five bend achromat lattices with six superperiod were designed. The obtained emittace is three times larger than the theoretical minimum. Tunes were chosen to avoid third order resonances. In order to correct first and second order chromaticities, eight family sextupoles were placed. The obtained emittance of five bend achromat lattices is almost equal to the minimum emittance of five bend achromat lattice consisting of dipoles with equal length.

Quantum mechanics the theoretical minimum

CERN Document Server

Susskind, Leonard

2014-01-01

From the bestselling author of The Theoretical Minimum, an accessible introduction to the math and science of quantum mechanicsQuantum Mechanics is a (second) book for anyone who wants to learn how to think like a physicist. In this follow-up to the bestselling The Theoretical Minimum, physicist Leonard Susskind and data engineer Art Friedman offer a first course in the theory and associated mathematics of the strange world of quantum mechanics. Quantum Mechanics presents Susskind and Friedman’s crystal-clear explanations of the principles of quantum states, uncertainty and time dependence, entanglement, and particle and wave states, among other topics. An accessible but rigorous introduction to a famously difficult topic, Quantum Mechanics provides a tool kit for amateur scientists to learn physics at their own pace.

Minimum resolvable power contrast model

Science.gov (United States)

Qian, Shuai; Wang, Xia; Zhou, Jingjing

2018-01-01

Signal-to-noise ratio and MTF are important indexs to evaluate the performance of optical systems. However,whether they are used alone or joint assessment cannot intuitively describe the overall performance of the system. Therefore, an index is proposed to reflect the comprehensive system performance-Minimum Resolvable Radiation Performance Contrast (MRP) model. MRP is an evaluation model without human eyes. It starts from the radiance of the target and the background, transforms the target and background into the equivalent strips,and considers attenuation of the atmosphere, the optical imaging system, and the detector. Combining with the signal-to-noise ratio and the MTF, the Minimum Resolvable Radiation Performance Contrast is obtained. Finally the detection probability model of MRP is given.

Observations of resonance-like structures for positron-atom elastic scattering at intermediate energies

International Nuclear Information System (INIS)

Dou, L.; Kauppila, W.E.; Kwan, C.K.; Stein, T.S.

1993-01-01

We have measured absolute values of elastic differential cross sections (DCS's) for positron (e + ) scattering by argon (8.7-300 eV), krypton (6.7-400 eV), and also neon (13.6-400 eV) using a crossed-beam experimental setup. When the DCS's are plotted at fixed scattering angles of 30 degrees, 60 degrees, 90 degrees, and 120 degrees versus energy it has been found that well-defined resonance-like structures were found at an energy of 55-60 eV for argon and at 25 and 200 eV for krypton, with a broader structure found between 100-200 eV for neon. These observed resonance-like structures are unusual because they occur at energies well above the known inelastic thresholds for these atoms. They may represent examples of open-quotes coupled channel shape resonancesclose quotes, first predicted by Higgins and Burke for e + -H scattering in the vicinity of 36 eV (width ∼ 4 eV), which occurs only when both the elastic and positronium formation scattering channels are considered together. A more recent e + -H calculation by Hewitt et al. supports the Higgins and Burke prediction. These predictions and the present observations suggest the existence of a new type of atomic scattering resonance

Reliability and Minimum Detectable Change of Temporal-Spatial, Kinematic, and Dynamic Stability Measures during Perturbed Gait.

Directory of Open Access Journals (Sweden)

Christopher A Rábago

lowest minimum detectable change values, supporting their use for tracking changes over multiple testing sessions. The between-session reliability and minimum detectable change values reported here provide an objective means for interpreting changes in temporal-spatial, kinematic variability, and dynamic stability measures during perturbed walking which may assist in identifying instability.

Polaron scattering by an external field

International Nuclear Information System (INIS)

Kochetov, E.A.

1980-01-01

The problem of polaron scattering by an external field is studied. The problem is solved using the stationary scattering theory formalism based on two operators: the G Green function operator and the T scattering operator. The dependence of the scattering amplitude on the quasi particle structure is studied. The variation approach is used for estimation of the ground energy level

Computer Support for Conducting Supportability Trade-Offs in a Team Setting

Science.gov (United States)

1990-01-01

with the ability of the product to be satisfactorily maintained throughout its intended useful life span with minimum expenditures of money and effort...during the pre-concept phase, thereby ensuring a reduction in cost due to reducing eventual retrofits, and a more supportable weapon system. Lauder ...It is shown that although large sums of money are expended on producing reliable components, these are vitiated if the end equipment is not exposed

Scattering Properties of Ground-State 23Na Vapor Using Generalized Scattering Theory

Science.gov (United States)

Al-Harazneh, A. A.; Sandouqa, A. S.; Joudeh, B. R.; Ghassib, H. B.

2018-04-01

The scattering properties of ground-state 23Na vapor are investigated within the framework of the Galitskii-Migdal-Feynman formalism. Viewed as a generalized scattering theory, this formalism is used to calculate the medium phase shifts. The scattering properties of the system—the total, viscosity, spin-exchange, and average cross sections—are then computed using these phase shifts according to standard recipes. The total cross section is found to exhibit the Ramsauer-Townsend effect as well as resonance peaks. These peaks are caused by the large difference between the potentials for electronic spin-singlet and spin-triplet states. They represent quasi-bound states in the system. The results obtained for the complex spin-exchange cross sections are particularly highlighted because of their importance in the spectroscopy of the Na2 dimer. So are the results for the scattering lengths pertaining to both singlet and triplet states. Wherever possible, comparison is made with other published results.

Experimental study of Rayleigh scattering with a ruby laser beam: relative variation of scattered light with the number of scattering center and the gases nature

International Nuclear Information System (INIS)

Bayer, Charles

1973-06-01

The experimental variation of the scattered light with the number of scattering centers and with the refraction index of gases is in agreement with the theoretical Rayleigh scattering. A direct calibration System gives the absolute value of the Rayleigh ratio. The experimental value appears to be half of the theoretical one. (author) [fr

Listening to light scattering in turbid media: quantitative optical scattering imaging using photoacoustic measurements with one-wavelength illumination

International Nuclear Information System (INIS)

Yuan, Zhen; Li, Xiaoqi; Xi, Lei

2014-01-01

Biomedical photoacoustic tomography (PAT), as a potential imaging modality, can visualize tissue structure and function with high spatial resolution and excellent optical contrast. It is widely recognized that the ability of quantitatively imaging optical absorption and scattering coefficients from photoacoustic measurements is essential before PAT can become a powerful imaging modality. Existing quantitative PAT (qPAT), while successful, has been focused on recovering absorption coefficient only by assuming scattering coefficient a constant. An effective method for photoacoustically recovering optical scattering coefficient is presently not available. Here we propose and experimentally validate such a method for quantitative scattering coefficient imaging using photoacoustic data from one-wavelength illumination. The reconstruction method developed combines conventional PAT with the photon diffusion equation in a novel way to realize the recovery of scattering coefficient. We demonstrate the method using various objects having scattering contrast only or both absorption and scattering contrasts embedded in turbid media. The listening-to-light-scattering method described will be able to provide high resolution scattering imaging for various biomedical applications ranging from breast to brain imaging. (papers)

Calculation of the minimum critical mass of fissile nuclides