Wind-Driven Angular Dependence of Sea-Surface Reflectance Measured with an Airborne Doppler Lidar
Tratt, David M.; Menzies, Robert T.; Cutten, Dean R.
1998-01-01
The effects of wind-stress on the optical properties of the ocean surface have been studied for several decades. In particular, the classic study by Cox and Munk (1954) linking sea-surface wind field to wave slope statistics provides a phenomenology by which the sea-surface wind velocity can be estimated from direct measurement of the wave-modulated surface reflectance. A limited number of studies along these lines have been conducted using airborne or spaceborne lidar systems. In these instances, truthing was provided by in situ ship reports or satellite microwave remote sensing instruments (e.g., ERS scatterometer, SSM/I). During the second deployment of the MACAWS Doppler wind lidar in the summer of 1996 measurements of sea-surface reflectance as a function of azimuth- and nadir-viewing angles were acquired off the California coast. MACAWS data products include directly measured winds, as well as calibrated backscatter/reflectance profiles, thus enabling comparison of the winds inferred from sea-surface reflectance measurements with those deriving from the Doppler-processed direct line-of-sight (LOS) estimates. Additional validation data was extracted from the ERS and SSM/I satellite microwave sensor archives maintained by the JPL Physical Oceanography Distributed Active Archive Center (PO- DAAC).
Dependency injection with AngularJS
Knol, Alex
2013-01-01
This book is a practical, hands-on approach to using dependency injection and implementing test-driven development using AngularJS. Dependency Injection with AngularJS is aimed at developers who are aware of AngularJS but need to get started with using it in real life applications. Also, developers who want to get into test-driven development with AngularJS can use this book as practical guide. Even if you know about dependency injection, it can serve as a good reference on how it is used within AngularJS. Readers are expected to have some experience with JavaScript.
Total internal reflection of orbital angular momentum beams
International Nuclear Information System (INIS)
We investigate how beams with orbital angular momentum (OAM) behave under total internal reflection. This is studied in two complementary experiments: in the first experiment, we study geometric shifts of OAM beams upon total internal reflection (Goos–Hänchen and Imbert–Fedorov shifts, for each the spatial and angular variant), and in the second experiment we determine changes in the OAM mode spectrum of a beam, again upon total internal reflection. As a result we find that, in the first case, the shifts are independent of OAM and beam focusing, while in the second case, modifications in the OAM spectrum occur which depend on the input OAM mode as well as on the beam focusing. This is investigated by experiment and theory. We also show how the two methods, beam shifts on the one hand, and OAM spectrum changes on the other, are related theoretically. (paper)
Total Internal Reflection of Orbital Angular Momentum Beams
Löffler, W; Aiello, Andrea; Woerdman, J P
2012-01-01
We investigate how beams with orbital angular momentum (OAM) behave under total internal reflection. This is studied in two complementary experiments: In the first experiment, we study geometric shifts of OAM beams upon total internal reflection (Goos-H\\"anchen and Imbert-Fedorov shifts, for each the spatial and angular variant), and in the second experiment we determine changes in the OAM mode spectrum of a beam, again upon total internal reflection. As a result we find that in the first case, the shifts are independent of OAM and beam focussing, while in the second case, modifications in the OAM spectrum occur which depend on the input OAM mode as well as on the beam focussing. This is investigated by experiment and theory. We also show how the two methods, beam shifts on the one hand, and OAM spectrum changes on the other, are related theoretically.
Total Internal Reflection of Orbital Angular Momentum Beams
Loffler W.; Hermosa N.; Aiello A.; Woerdman J.P.
2012-01-01
We investigate how beams with orbital angular momentum (OAM) behave under total internal reflection. This is studied in two complementary experiments: In the first experiment, we study geometric shifts of OAM beams upon total internal reflection (Goos-H\\"anchen and Imbert-Fedorov shifts, for each the spatial and angular variant), and in the second experiment we determine changes in the OAM mode spectrum of a beam, again upon total internal reflection. As a result we find that in the first cas...
Angular dependent light emission from planar waveguides
International Nuclear Information System (INIS)
We have investigated the angular dependence of amplified spontaneous emission (ASE) and laser emission from an asymmetric and free-standing polymer thin films doped with rhodamine 6G, which is transversely pumped by a pulsed Nd:YAG laser. A semi-leaky waveguide or quasi-waveguide structure has been developed by spin coating technique. In these waveguides, the light was confined by the film/air-film/glass substrate interfaces. At the film/substrate interface, a portion of light will reflect back into the film (guided mode) and the remaining refracted to the substrate resulting in cutoff modes. A blue-shift in ASE has been observed when the pump power was increased from 8 to 20 mW allowing a limited range of tuning of emission wavelength. To study the directionality of the ASE from the waveguide, we have measured the output intensity and FWHM of emission spectra as a function of viewing angle (θ) from the plane parallel to film. From the detailed examination of the output emission spectra, as +θ increases from 0° there has been an initial decrease in output intensity, but at a particular angle ≈10° an increase in output intensity was observed. This additional peak in output intensity as +θ is a clear indication of coexistence of the cutoff mode. We also present a compact solid-state laser based on leaky mode propagation from the dye-doped polymer free-standing film (∼50 μm thickness) waveguide. The partial reflections from the broad lateral surfaces of the free-standing films provided the optical feedback for the laser emission with high directionality. For a pump power of 22 mW, an intense line with FWHM <0.2 nm was observed at 578 nm
Probabilistic calculation for angular dependence collision
International Nuclear Information System (INIS)
This collision probabilistic method is broadly used in cylindrical geometry (in one- or two-dimensions). It constitutes a powerful tool for the heterogeneous Response Method where, the coupling current is of the cosine type, that is, without angular dependence at azimuthal angle θ and proportional to μ (cosine of the θ polar angle). (Author)
Time-dependent angularly averaged inverse transport
Bal, Guillaume; Jollivet, Alexandre
2009-01-01
This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from knowledge of angularly averaged measurements performed at the boundary of a domain of interest. We show that the absorption coefficient and the spatial component of the scattering coefficient are uniquely determined by such measurements. We obtain stability results on the reconstruction of the absorption and scattering parameters with respect to the measured al...
Differential reflective fiber-optic angular displacement sensor
Shan, Mingguang; Min, Rui; Zhong, Zhi; Wang, Ying; Zhang, Yabin
2015-05-01
Using the characteristic that the distance apart between the emitting fiber and receiving fiber only shifts the angular-power curve, a differential reflective fiber-optic sensor for angular displacement measurement is presented through subtraction of two power signals from two receiving fibers placed on both sides of one emitting fiber. A theoretical model is established to characterize the performance of the differential reflective fiber-optic angular displacement sensor. The measurements made indicate that the general behavior of the experimental results agrees with that of the theoretical results, and the sensor can improve sensitivity by about 120%, resulting in the significant improvement of anti-interference capability, which will be more suitable for high accuracy bipolar absolute angular displacement measurement. Design guidelines are also suggested to achieve desired sensor performances.
How orbital angular momentum affects beam shifts in optical reflection
International Nuclear Information System (INIS)
It is well known that reflection of a Gaussian light beam (TEM00) by a planar dielectric interface leads to four beam shifts when compared to the geometrical-optics prediction. These are the spatial Goos-Haenchen (GH) shift, the angular GH shift, the spatial Imbert-Fedorov (IF) shift, and the angular IF shift. We report here, theoretically and experimentally, that endowing the beam with orbital angular momentum leads to coupling of these four shifts; this is described by a 4x4 mixing matrix.
Time-dependent angularly averaged inverse transport
International Nuclear Information System (INIS)
This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from knowledge of angularly averaged measurements performed at the boundary of a domain of interest. Such measurement settings find applications in medical and geophysical imaging. We show that the absorption coefficient and the spatial component of the scattering coefficient are uniquely determined by such measurements. We obtain stability results on the reconstruction of the absorption and scattering parameters with respect to the measured albedo operator. The stability results are obtained by a precise decomposition of the measurements into components with different singular behavior in the time domain
Time-dependent angularly averaged inverse transport
Bal, Guillaume
2009-01-01
This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from knowledge of angularly averaged measurements performed at the boundary of a domain of interest. We show that the absorption coefficient and the spatial component of the scattering coefficient are uniquely determined by such measurements. We obtain stability results on the reconstruction of the absorption and scattering parameters with respect to the measured albedo operator. The stability results are obtained by a precise decomposition of the measurements into components with different singular behavior in the time domain.
Orbital angular momentum is dependent on polarization
Li, Chun-Fang
2009-01-01
It is shown that the momentum density of free electromagnetic field splits into two parts. One has no contribution to the net momentum due to the transversality condition. The other yields all the momentum. The angular momentum that originates from the former part is spin, and the angular momentum that originates from the latter part is orbital angular momentum. Expressions for the spin and orbital angular momentum are given in terms of the electric vector in reciprocal space. The spin and or...
Relativistic calculations of angular dependent photoemission time delay
Kheifets, A S; Deshmukh, P C; Dolmatov, V K; Manson, S T
2016-01-01
Angular dependence of photoemission time delay for the valence $np_{3/2}$ and $np_{1/2}$ subshells of Ar, Kr and Xe is studied in the dipole relativistic random phase approximation. Strong angular anisotropy of the time delay is reproduced near respective Cooper minima while the spin-orbit splitting affects the time delay near threshold.
Angular dependence of anisotropic magnetoresistance in magnetic systems
Zhang, Steven S.-L.; Zhang, Shufeng
2014-05-01
Anisotropic magnetoresistance (AMR), whose physical origin is attributed to the combination of spin dependent scattering and spin orbital coupling (SOC), usually displays simple angular dependence for polycrystalline ferromagnetic metals. By including generic spin dependent scattering and spin Hall (SH) terms in the Ohm's law, we explicitly show that various magneto-transport phenomena such as anomalous Hall (AH), SH, planar Hall (PH) and AMR could be quantitatively related for bulk polycrystalline ferromagnetic metals. We also discuss how AMR angular dependence is affected by the presence of interfacial SOC in magnetic layered structure.
Modeling of the angular dependence of plasma etching
International Nuclear Information System (INIS)
An understanding of the angular dependence of etching yield is essential to investigate the origins of sidewall roughness during plasma etching. In this article the angular dependence of polysilicon etching in Cl2 plasma was modeled as a combination of individual angular-dependent etching yields for ion-initiated processes including physical sputtering, ion-induced etching, vacancy generation, and removal. The modeled etching yield exhibited a maximum at ∼60 degree sign off-normal ion angle at low flux ratio, indicative of physical sputtering. It transformed to the angular dependence of ion-induced etching with the increase in the neutral-to-ion flux ratio. Good agreement between the modeling and the experiments was achieved for various flux ratios and ion energies. The variation of etching yield in response to the ion angle was incorporated in the three-dimensional profile simulation and qualitative agreement was obtained. The surface composition was calculated and compared to x-ray photoelectron spectroscopy (XPS) analysis. The modeling indicated a Cl areal density of 3x1015 atoms/cm2 on the surface that is close to the value determined by the XPS analysis. The response of Cl fraction to ion energy and flux ratio was modeled and correlated with the etching yields. The complete mixing-layer kinetics model with the angular dependence effect will be used for quantitative surface roughening analysis using a profile simulator in future work.
Angular and energetic dependence of photographic dosemeters for beta radiation
International Nuclear Information System (INIS)
Photographic dosemeters (Agfa-Gevaert) used in personal monitoring at IPEN/CNEN-SP (Brazil) are studied. The angular (between O and 1800) and energetic dependence in beta radiation exposures are discussed. The dosemeters are analysed with and without dosemeter - holder and retroscatter material. (M.A.C.)
Angular dependence of spin-orbit spin-transfer torques
Lee, Ki-Seung
2015-04-06
In ferromagnet/heavy-metal bilayers, an in-plane current gives rise to spin-orbit spin-transfer torque, which is usually decomposed into fieldlike and dampinglike torques. For two-dimensional free-electron and tight-binding models with Rashba spin-orbit coupling, the fieldlike torque acquires nontrivial dependence on the magnetization direction when the Rashba spin-orbit coupling becomes comparable to the exchange interaction. This nontrivial angular dependence of the fieldlike torque is related to the Fermi surface distortion, determined by the ratio of the Rashba spin-orbit coupling to the exchange interaction. On the other hand, the dampinglike torque acquires nontrivial angular dependence when the Rashba spin-orbit coupling is comparable to or stronger than the exchange interaction. It is related to the combined effects of the Fermi surface distortion and the Fermi sea contribution. The angular dependence is consistent with experimental observations and can be important to understand magnetization dynamics induced by spin-orbit spin-transfer torques.
Angular dependence of Wigner time delay: Relativistic Effects
Mandal, A.; Deshmukh, P. C.; Manson, S. T.; Kkeifets, A. S.
2016-05-01
Laser assisted photoionization time delay mainly consists of two parts: Wigner time delay, and time delay in continuum-continuum transition. Wigner time delay results from the energy derivative of the phase of the photoionization amplitude (matrix element). In general, the photoionization time delay is not the same in all directions relative to the incident photon polarization, although when a single transition dominates the amplitude, the resultant time delay is essentially isotropic. The relativistic-random-phase approximation is employed to determine the Wigner time delay in photoionization from the outer np subshells of the noble gas atoms, Ne through Xe. The time delay is found to significantly depend on angle, as well as energy. The angular dependence of the time delay is found to be quite sensitive to atomic dynamics and relativistic effects, and exhibit strong energy and angular variation in the neighborhood of Cooper minima. Work supported by DOE, Office of Chemical Sciences and DST (India).
Angular dependence of dosimetric films for gamma radiation
International Nuclear Information System (INIS)
In most situations, radiations workers are subjected to radiation exposures at randon angles of incidence. Consequentetly, the personnel dose estimates would be lower since calibration is usually accomplished with stationary films positioned perpendicular to beam on radiation, i.e., at normal incidence. In oder to obtain an error estimate due to angular dependence the radiation incidence angle related to badges having Agfa Gevaert Struturix D2 and D10 (commonly used in individual dosimeter) was variated between 0 and 900. (author)
Angular dependence of silicon oxide etching yield in fluorocarbon chemistries
International Nuclear Information System (INIS)
High density fluorocarbon plasma for silicon oxide etching has various ion and neutral species. Profile evolution modeling can provide understanding of many difficulties caused by the complexity of the plasma in etching. In this research we have measured etching and deposition rates as functions of ion impinging angle, sample temperature, which are necessary for profile evolution modeling of silicon oxide etching in inductively coupled plasma. Angular dependence of etching yield of oxide in fluorocarbon plasma shows very unique behavior unlike typical ion-induced chemical etching or physical sputtering. Ion-induced deposition model is suggested and tested
Angular momentum of non-paraxial light beam: Dependence of orbital angular momentum on polarization
Li, Chun-Fang
2009-01-01
It is shown that the momentum density of free electromagnetic field splits into two parts. One has no contribution to the net momentum due to the transversality condition. The other yields all the momentum. The angular momentum that is associated with the former part is spin, and the angular momentum that is associated with the latter part is orbital angular momentum. Expressions for the spin and orbital angular momentum are given in terms of the electric vector in reciprocal space. The spin ...
Angular dependence of primordial trispectra and CMB spectral distortions
Shiraishi, Maresuke; Liguori, Michele
2016-01-01
Under the presence of anisotropic sources in the inflationary era, the trispectrum of the primordial curvature perturbation is sensitive to the angles between each wave vector. We examine the imprints left by curvature trispectra, in which the angular dependence is described by Legendre polynomials, on the $TT\\mu$ bispectrum, generated by the correlation between temperature anisotropies (T) and chemical potential spectral distortions ($\\mu$) of the Cosmic Microwave Background (CMB). Due to the angular dependence of the primordial signal, the corresponding $TT\\mu$ bispectrum strongly differs in shape from $TT\\mu$ sourced by the usual $g_{\\rm NL}$ or $\\tau_{\\rm NL}$ local trispectra, enabling us to obtain an unbiased estimation. From a Fisher matrix analysis, we find that, in a cosmic-variance-limited (CVL) survey of $TT\\mu$, a minimum detectable value of the quadrupolar Legendre coefficient is $d_2 \\sim 0.01$, which is 4 orders of magnitude better than the best value attainable from the $TTTT$ CMB trispectrum....
Angular dose dependency of MatriXX and its calibration
International Nuclear Information System (INIS)
Objective: To characterize angular dependency of MatriXX and develop a method for its calibration in order to verify treatment plan with original gantry angles. Methods: Absolute dose calibration was carried with thimble ionization chamber on the linear accelerator, so as to make sure 1 MU=1 cGy at the depth of maximum dose (dmax). A MatriXX was put into a Mutlicube phantom, and the ionization chamber matrix was calibrated with absolute dose. In order to determine a correction factor CF as a function of gantry angle θ, open beam fields of 10 cm×10 cm size were irradiated for gantry angles θ=0°-180° (every 5°) and every 1°for lateral angles θ in the range of 85°-95°. CF was defined as the ratio of the dose measured with ionization chamber and the dose from MatriXX. Results: Relatively large discrepancies in response to posterior VS, anterior fields for MatriXX detectors (up to 10%) were found during the experiment and relatively large variability of response as a function of gantry angle. The pass rate of treatment plan in lateral beams was lower than that of other beams. The isodose distribution of corrected MatriXX matched well with the outcome from the treatment planning system. Conclusions: The angular dose dependency of MatriXX must be considered when it is used to verify the treatment plan with original gantry angles. (authors)
International Nuclear Information System (INIS)
The reflection and transmission of a paraxial light beam carrying the intrinsic orbital angular momentum (IOAM) at the plane interface of two isotropic transparent media are considered. The physical explanations of the IOAM-dependent effects accompanying this process are given. These effects are as follows: the changes of the IOAM after the beam's reflection and transmission and the IOAM-stipulated changes of the intensity distribution inside the secondary beams; the latter effects entail the specific shifts of the centers of gravity of the secondary beams in the direction perpendicular to the plane of incidence
Angular dependence of the coercivity in arrays of ferromagnetic nanowires
International Nuclear Information System (INIS)
We present a new magnetic model for polycrystalline nanowires arrays in porous anodic aluminum oxide. The principal consideration here is the crystalline structure and the morphology of the wires and them the dipolar interactions between the crystals into the wire. Other aspect here is the direct calculation of the dipolar energy for the interaction of one wire with the others in the array. The free energy density was formulated for polycrystalline nanowires arrays in order to determinate the anisotropy effective field. It was using the microstructure study by scanning and transmission electron microscopy for the estimation of the real structure of the wires. After the structural analysis we used the angular dependences for the coercivity field and for the remnant magnetization to determine the properties of the wires. All analysis were made by the theory treatment proposed by Stoner and Wohlfarth
Angular dependence of interactions in polycrystalline Co nanowire arrays
International Nuclear Information System (INIS)
Ordered Co nanowire arrays with a constant geometry (∼40 nm diameter, ∼10 μm length and ∼100 nm interwire distance) were ac pulse electrodeposited into anodic aluminum oxide template under different deposition current densities (5.31, 7.08 and 8.85 mA/cm2). Microstructure and magnetic properties of the samples were studied using X-ray diffraction (XRD) pattern, selected area diffraction (SAED) pattern and first-order reversal curve (FORC) diagrams. SAED patterns showed inhomogeneous polycrystalline structure along the length of a nanowire. FORC diagrams revealed two-phase magnetic behavior in which soft and hard magnetic phases related to triplet cobalt crystalline directions. Despite the fact that angular dependence of hysteresis loops provides information about magnetization reversal, angular FORC offers additional information on the magnetostatic and interphase interactions depending on angle between the field and nanowires axis (α). Different magnetic behaviors were seen by change in α; interacting two-phase behavior in α = 0° which reduced to a non-interacting behavior for α > 60° may be attributed to reduce delay in magnetization reversal of two phases. Increasing the reversible portion of the major hysteresis loop in α = 90° is a possible source of difference between the hard to soft ratio obtained from FORC diagrams and XRD patterns. - Highlights: • Increasing α cause to reduce demagnetizing interaction and remove additional feature in 90°. • Magnetic behavior of Co-hcp(002) change from hard to soft phase as α increased from 0 to 90°. • Increasing reversible portion in 90° is source of different hard-soft ratio obtained from FORC and XRD
International Nuclear Information System (INIS)
Using the computer experiment methods directional effects of relativistic electrons' coherent reflection from crystal surface at glancing incidence were studied in conditions when it is due to multiple transversal scattering of particles by atomic chains (axial surface channeling). Directional dependencies of backscattering coefficients, ranges and depths of reflected electrons' penetration in crystal and their angular distributions have been calculated. It has allowed to elicit the directional effects of strings that lead to reflection at grazing angles close to the beam incident angle with respect to atomic chain as well as kinetic effects of surface plane that result in specular reflection and dominate at large beam misalignments with respect to low-index crystallographic directions
Angular dependence of the spin textures in two-dimensional chiral magnets
Energy Technology Data Exchange (ETDEWEB)
Tang, Dan [Institute of Materials Physics and Chemistry, Northeastern University, Shenyang 110004 (China); Institute of Applied Physics and Technology, Liaoning Technical University, Huludao 125105 (China); Qi, Yang, E-mail: qiyang@imp.neu.edu.cn [Institute of Materials Physics and Chemistry, Northeastern University, Shenyang 110004 (China)
2015-05-28
The angular dependence of spin textures in thin helimagnetic films is investigated by a Monte Carlo simulation. When an external field is applied at an angle relative to the film normal, we find that the skyrmion states with broken axis-symmetric structure are able to persist over a wide range of angles by changing the spin orientation. In addition, the uniaxial anisotropy is able to stabilize the distorted skyrmions. This behavior reflects the robust topological stability of skyrmion states in helimagnets and favors their application in spintronic devices.
Russo, Juan M.; Castillo, Jose E.; Aspnes, Eric D.; Kostuk, Raymond K.; Rosenberg, Glenn
2010-08-01
Dual aperture holographic planar concentrator (DA-HPC) technology consists of bifacial cells separated by strips of holographic film that diffract the light from the spacing into the cells for direct incident, diffuse, roof-reflected and albedo irradiance. The holographic film is angularly dependent of the seasonal sun angle. DA-HPC modules are compared to single aperture conventional modules for clear and cloudy days as well as for a seasonal period of eight months. Direct-current IV and alternating-current power curves are used to compare modules with comparable silicon active area and cell efficiency.
Sensitivity in frequency dependent angular rotation of optical vortices.
Rumala, Yisa S
2016-03-10
This paper presents robust strategies to enhance the rotation sensitivity (and resolution) of a coherent superposition of optical vortices emerging from a single spiral phase plate (SPP) device when light's optical frequency (or wavelength) going into the SPP device is varied. The paper discusses the generation and measurement of ultrasmall rotation. Factors that affect the ability to perform precision rotation measurements include the linewidth and stability of the input light source, the number of photon counts making position rotation measurements on the CCD detector, SPP reflectivity, the length of SPP device, and the angular modulation frequency of the intensity pattern due to a coherent superposition of optical vortices in a single SPP device. This paper also discusses parameters to obtain a high-sensitivity single shot measurement and multiple measurements. Furthermore, it presents what I believe is a new scaling showing the enhancement in sensitivity (and resolution) in the standard quantum limit and Heisenberg limit. With experimentally realizable parameters, there is an enhancement of rotation sensitivity by at least one order of magnitude compared to previous rotation measurements with optical vortices. Understanding robust strategies to enhance the rotation sensitivity in an SPP device is important to metrology in general and for building compact SPP sensors such as gyroscopes, molecular sensors, and thermal sensors. PMID:26974798
Angular dependent rebalance method for solving the neutron transport equation
International Nuclear Information System (INIS)
objective of this thesis is to develop an acceleration technique that has good stability and rapid convergence for general discrete ordinates transport methods. For this purpose, the author develops a new general nonlinear iteration method based on angular dependent rebalance factor concept called the Angular Dependent Rebalance (ADR) Method. The acceleration method uses a lower-order equation at each iteration to improve the result of the higher-order equation. In deriving the lower-order equation, the rebalance factor is used similarly as in the conventional fine-mesh rebalance (FMR) method. However, in the ADR method, the rebalance factor is angular space. In fact, the angular dependency of the rebalance factor is approximated by the DPN expansion method and the low order SN expansion method for the case of one-dimensional geometry and by the S2 method for the case of two-dimensional geometry. As a result, the lower-order equation of the ADR method resembles the transport equation. Therefore, the lower equation is very easily derived and simple to implement for various kinds of the numerical transport methods in general geometries. Also, the ADR method avoids the 'consistent differencing' issues in DSA because the lower-order equation is derived exactly from the transport equation except for the approximation in angular dependency of the rebalance factor. Unlike previous methods, the ADR method allows the inconsistent combination of lower-order equation and higher-order equation and these inconsistent combinations do not generate numerical instabilities. The similarity of the lower-order equation to the transport equation requires an effective iterative method for solving the lower-order equation. The speedup of ADR with respect to SI is highly dependent on how efficiently the lower-order equation is solved. In this thesis, three methods are considered as an effective solver to solve the lower-order equation of ADR. First is the two cyclic iterative method (or
Yonetani, Yusuke; Nitta, Kouichi; Matoba, Osamu
2010-02-01
We evaluate numerically the effect of shrinkage of photopolymer on the bit error rate or signal-to-noise ratio in a reflection-type holographic data storage system with angular multiplexing. In the evaluation, we use a simple model where the material is divided into layered structures and then the shrinkage rate is proportional to the intensity in each layer. We present the effectiveness of the proposed model from the experimental results in the recording of the plane waves both in a transmission-type hologram and a reflection-type one. Several kinds of shrinkage rates are used to evaluate the characteristics of angular multiplexing in the reflection-type holographic memory. PMID:20119021
Reflection of the light beam carrying orbital angular momentum from a lossy medium
Energy Technology Data Exchange (ETDEWEB)
Fedoseyev, V.G. [Institute of Physics, University of Tartu, Riia 142, 51014 Tartu (Estonia)], E-mail: fedo@fi.tartu.ee
2008-03-31
It is shown that after reflection from a lossy medium the s- or p-polarized paraxial light beam carrying the orbital angular momentum suffers the 2D shift of the beam's centre of gravity relative the geometric optic axis. The direction as well as the length of the 2D vector, which describes the shift, change smoothly with the change of the angle of incidence.
Practical Reflection and Metaprogramming for Dependent Types
DEFF Research Database (Denmark)
Christiansen, David Raymond
2016-01-01
program in these embedded languages. Interpreters and compilers must always take these invariants into account at each stage, and authors of embedded languages must work hard to relieve users of the burden of proving these properties. Idris is a dependently typed functional programming language whose...... semantics are given by elaboration to a core dependent type theory through a tactic language. This dissertation introduces elaborator reflection, in which the core operators of the elaborator are realized as a type of computations that are executed during the elaboration process of Idris itself, along with...
Angular dependence to the threshold intensity of scattered radiation for passing ionic-sound waves
International Nuclear Information System (INIS)
Present article is devoted to angular dependence to the threshold intensity of scattered radiation for passing ionic-sound waves. The angular dependence of intensity of scattered radiation in two-dimensional field of localization of a wave of a rating of passing ionic-sound waves at any scattering angles was considered. (author)
Karras, G.; Kosmidis, C.
2010-10-01
The angular distribution of the fragment ions ejected from the interaction of methyl iodide clusters with 20 fs strong laser pulses is studied by means of a mass spectrometer. Three types of angular distributions, one isotropic and two anisotropic, have been observed and their dependence on the laser intensity has been studied. There is strong evidence that the ions exhibiting anisotropic angular distribution with a maximum in the direction parallel to the laser polarization vector are produced via an electron impact ionization process.
Light scattering by fractal dust aggregates: I. Angular dependence of scattering
Tazaki, Ryo; Okuzumi, Satoshi; Kataoka, Akimasa; Nomura, Hideko
2016-01-01
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 (BPCAs). 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 scatteri...
Depth and latitude dependence of the solar internal angular velocity
Energy Technology Data Exchange (ETDEWEB)
Rhodes, E.J. Jr.; Cacciani, A.; Korzennik, S.; Tomczyk, S.; Ulrich, R.K.; Woodard, M.F. (Southern California Univ., Los Angeles, CA (USA) JPL, Pasadena, CA (USA) Roma I Universita (Italy) California Univ., Los Angeles (USA))
1990-03-01
One of the design goals for the dedicated helioseismology observing state located at Mount Wilson Observatory was the measurement of the internal solar rotation using solar p-mode oscillations. In this paper, the first p-mode splittings obtained from Mount Wilson are reported and compared with those from several previously published studies. It is demonstrated that the present splittings agree quite well with composite frequency splittings obtained from the comparisons. The splittings suggest that the angular velocity in the solar equatorial plane is a function of depth below the photosphere. The latitudinal differential rotation pattern visible at the surface appears to persist at least throughout the solar convection zone. 43 refs.
Depth and latitude dependence of the solar internal angular velocity
Rhodes, Edward J., Jr.; Cacciani, Alessandro; Korzennik, Sylvain; Tomczyk, Steven; Ulrich, Roger K.; Woodard, Martin F.
1990-01-01
One of the design goals for the dedicated helioseismology observing state located at Mount Wilson Observatory was the measurement of the internal solar rotation using solar p-mode oscillations. In this paper, the first p-mode splittings obtained from Mount Wilson are reported and compared with those from several previously published studies. It is demonstrated that the present splittings agree quite well with composite frequency splittings obtained from the comparisons. The splittings suggest that the angular velocity in the solar equatorial plane is a function of depth below the photosphere. The latitudinal differential rotation pattern visible at the surface appears to persist at least throughout the solar convection zone.
International Nuclear Information System (INIS)
A new coarse-mesh rebalance method is developed and tested to accelerate one-dimensional discrete ordinates neutron transport equation. The method is based on the use of angular dependent rebalance factors. Unlike the original Coarse-Mesh Rebalance method, Fourier analysis and numerical results show that this Angular Dependent Coarse-Mesh Rebalance(ADCMR) method is unconditionally stable for any optical thickness and that the acceleration effect is significant
Characterization of multi-angular hyperspectral polarized reflectance from coastal waters
Gilerson, A.; Tonizzo, A.; Zhou, J.; Dyer, R.; Chowdhary, J.; Gross, B.; Moshary, F.; Ahmed, S.
2008-10-01
Since scattering by molecules, particles, aerosols, hydrosols and reflection at the sea surface introduce and modify the polarization state of light, the polarized underwater light field contains embedded information about the intrinsic nature of various water constituents (biogenic, nonalgal and inorganic particles, dissolved matter), and can be used in retrieval algorithms for the separation of organic and inorganic particulates, in improving underwater visibility and in other active techniques and applications. To study underwater polarization characteristics a new instrument has been developed by the Optical Remote Sensing Laboratory at CCNY. The instrument consists of three Satlantic Hyperspectral radiance sensors mounted on a scanning system controlled by an underwater electric stepper motor. The motor rotates the sensors in a vertical plane in a specific angular range. This can be adjusted according to the solar altitude angle in order to cover the full 0-180° scattering angle range. Linear polarizers are attached in front of the sensors; the polarizers are oriented at 0° (vertical), 90 °(horizontal) and 45°. By rotating the sensors relative to the nadir direction, the instrument scans the angular features of the underwater polarized light field in a vertical plane defined by its azimuth angle relative to the sun. Angular variations of the degree of polarization are found to be consistent with theory. Maximum values of the degree of polarization do not exceed 0.5 while the position of the maximum is shifted from 90° towards higher scattering angles. The results presented here will need to be corroborated with additional measurements in varying water conditions.
Sun, Z. Q.; Wu, Z. F.; Zhao, Y. S.
2014-01-01
In this paper, the design and operation of the Northeast Normal University Laboratory Goniospectrometer System for performing multi-angular reflected and polarized measurements under controlled illumination conditions is described. A semi-automatic arm, which is carried on a rotated circular ring, enables the acquisition of a large number of measurements of surface Bidirectional Reflectance Factor (BRF) over the full hemisphere. In addition, a set of polarizing optics enables the linear polarization over the spectrum from 350 nm to 2300 nm. Because of the stable measurement condition in the laboratory, the BRF and linear polarization has an average uncertainty of 1% and less than 5% depending on the sample property, respectively. The polarimetric accuracy of the instrument is below 0.01 in the form of the absolute value of degree of linear polarization, which is established by measuring a Spectralon plane. This paper also presents the reflectance and polarization of snow, soil, sand, and ice measured during 2010-2013 in order to illustrate its stability and accuracy. These measurement results are useful to understand the scattering property of natural surfaces on Earth.
Practical Reflection and Metaprogramming for Dependent Types
DEFF Research Database (Denmark)
Christiansen, David Raymond
2016-01-01
a programmable programming language and allowing code re-use across all three stages: elaboration, type checking, and execution. Beyond elaborator reflection, other forms of compile-time reflection have proven useful for embedded languages. This dissertation also describes error reflection, in which...... Idris code can rewrite DSL error messages before presenting domain-specific messages to users, as well as a means for integrating quasiquotation into a tactic-based elaborator so that high-level syntax can be used for low-level reflected terms....
Angular dependence of surfactant-mediated forces between carbon nanotubes.
Müter, Dirk; Angelikopoulos, Panagiotis; Bock, Henry
2012-12-27
We employ dissipative particle dynamics to examine surfactant-mediated forces between two carbon nanotubes. Calculations are performed varying both the distance and the angle between the nanotubes. For small distances, a repulsive region is observed, followed by an overall attractive interval with strong oscillations in the force. Decreasing the angle between the tubes leads to a steady increase in the force, but the relative dependence on the separation distance is preserved. We find that the force scales linearly with the size of the overlap area between the tubes. This allows us to express the angle dependence by a simple equation, whereas the distance dependence is represented by a master curve. For the parallel case, the behavior is significantly different. PMID:23116052
ANGULAR VELOCITY AND CORIOLIS EFFECT IN TIME-DEPENDENT QUANTUM MECHANICAL SU2 ROTATION
Institute of Scientific and Technical Information of China (English)
FAN HONG-YI; SUN MING-ZHAI
2001-01-01
Starting from a time-dependent rotation U (t) in SU2 group element space, we derive its corresponding quantum mechanical dynamic Coriolis term and the relationship between U (t) and rotational angular velocity. Throughout our discussion, the technique of integration within an ordered product of operators is fully used, which has the advantage that the correspondence between the classical rotation and the quantum rotation is in a transparent fashion. A new angular-velocity formula is also derived.
Hori, Masahiro; Aoki, Teruo; Tanikawa, Tomonori; Hachikubo, Akihiro; Sugiura, Konosuke; Kuchiki, Katsuyuki; Niwano, Masashi
2013-10-20
A model of angular-dependent emissivity spectra of snow and ice in the 8-14 μm atmospheric window is constructed. Past field research revealed that snow emissivity varies depending on snow grain size and the exitance angle. Thermography images acquired in this study further revealed that not only welded snow particles such as sun crust, but also disaggregated particles such as granular snow and dendrite crystals exhibit high reflectivity on their crystal facets, even when the bulk snow surface exhibits blackbody-like behavior as a whole. The observed thermal emissive behaviors of snow particles suggest that emissivity of the bulk snow surface can be expressed by a weighted sum of two emissivity components: those of the specular and blackbody surfaces. Based on this assumption, a semi-empirical emissivity model was constructed; it is expressed by a linear combination of specular and blackbody surfaces' emissivities with a weighting parameter characterizing the specularity of the bulk surface. Emissivity spectra calculated using the model succeeded in reproducing the past in situ measured directional spectra of various snow types by employing a specific weighting parameter for each snow type. PMID:24216578
Angular dependent transport properties of MgB2 films with columnar grains
International Nuclear Information System (INIS)
We studied the angular dependence of the transport properties of MgB2 films with columnar grains grown by hybrid physical chemical vapor deposition method, one sample with unreacted boron in the volume and the other sample with no traceable impurity phase. The angular dependence of resistivity and critical current density in applied magnetic fields for both samples showed a flux pinning effect by the grain boundaries between columnar grains. The temperature dependence of the upper critical fields was analyzed by using the dirty-limit two-gap model. We found that the unreacted boron in the body of the film had negative effect on flux pinning and intraband electron diffusivities
A study of angular dependence in the ablation rate of polymers by nanosecond pulses
Pedder, James E. A.; Holmes, Andrew S.
2006-02-01
Measurements of ablation rate have traditionally been carried out only at normal incidence. However, in real-world applications ablation is often carried out at oblique angles, and it is useful to have prior knowledge of the ablation rate in this case. Detailed information about the angular dependence is also important for the development of ablation simulation tools, and can provide additional insight into the ablation mechanism. Previously we have reported on the angular dependence of direct-write ablation at 266 nm wavelength in solgel and polymer materials. In this paper we present a systematic study of angular dependence for excimer laser ablation of two polymer materials of interest for microfabrication: polycarbonate and SU8 photoresist. The results are used to improve simulation models to aid in mask design.
International Nuclear Information System (INIS)
X-ray reflection models are used to constrain the properties of the accretion disk, such as the degree of ionization of the gas and the elemental abundances. In combination with general relativistic ray tracing codes, additional parameters like the spin of the black hole and the inclination to the system can be determined. However, current reflection models used for such studies only provide angle-averaged solutions for the flux reflected at the surface of the disk. Moreover, the emission angle of the photons changes over the disk due to relativistic light bending. To overcome this simplification, we have constructed an angle-dependent reflection model with the XILLVER code and self-consistently connected it with the relativistic blurring code RELLINE. The new model, relxill, calculates the proper emission angle of the radiation at each point on the accretion disk and then takes the corresponding reflection spectrum into account. We show that the reflected spectra from illuminated disks follow a limb-brightening law highly dependent on the ionization of disk and yet different from the commonly assumed form I∝ln (1 + 1/μ). A detailed comparison with the angle-averaged model is carried out in order to determine the bias in the parameters obtained by fitting a typical relativistic reflection spectrum. These simulations reveal that although the spin and inclination are mildly affected, the Fe abundance can be overestimated by up to a factor of two when derived from angle-averaged models. The fit of the new model to the Suzaku observation of the Seyfert galaxy Ark 120 clearly shows a significant improvement in the constraint of the physical parameters, in particular by enhancing the accuracy in the inclination angle and the spin determinations.
Angular dependence of magnetoresistance in silicon with nanoclusters of manganese atoms
International Nuclear Information System (INIS)
In silicon samples doped by manganese a significant angular dependence of magnetoresistance has been experimentally observed. In samples in which the greater part of atoms is located in clusters, the negative magnetoresistance has maximal value at φ=90 deg and 270 deg and minimal one at φ=0 deg, 180 deg and 360 deg. In overcompensated samples, where nanoclusters did not reveal, on the contrary, the magnetoresistance has maximal value at φ=0 deg, 180 deg and 360 deg and minimal value at φ=90 deg and 270 deg. A character of angular dependence of magnetoresistance does not affected by temperature and level of lighting of samples. (authors)
Light Scattering by Fractal Dust Aggregates. I. Angular Dependence of Scattering
Tazaki, Ryo; Tanaka, Hidekazu; Okuzumi, Satoshi; Kataoka, Akimasa; Nomura, Hideko
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.
Determination of the angular dependence of the detector matrix Matrix X-evolution of IBA
International Nuclear Information System (INIS)
The objective of this work consists in determining the correction for the angular dependence of the detector-Evolution Matrix x matrix (IBA, Germany), when used in the multi cube dummy (IBA, Germany), verification of treatment VMAT IMRT, using the software OP'IMRT (IBA, Germany).
Temperature and angular momentum dependence of the quadrupole deformation in sd-shell
Indian Academy of Sciences (India)
P A Ganai; J A Sheikh; I Maqbool; R P Singh
2009-11-01
Temperature and angular momentum dependence of the quadrupole deformation is studied in the middle of the sd-shell for 28Si and 27Si isotopes using the spherical shell model approach. The shell model calculations have been performed using the standard universal sd-shell (USD) interaction and the canonical partition function constructed from the calculated eigensolutions. It is shown that the extracted average quadrupole moments show a transitional behaviour as a function of temperature and the infered transitional temperature is shown to vary with angular momentum. The quadrupole deformation of the individual eigenstate is also analysed.
Temperature and angular momentum dependence of the quadrupole deformation in sd-shell
Ganai, P A; Maqbool, I; Singh, R P
2009-01-01
Temperature and angular momentum dependence of the quadrupole deformation is studied in the middle of the sd-shell for 28Si and 27Si isotopes using the spherical shell model approach. The shell model calculations have been performed using the standard USD interaction and the canonical partition function constructed from the calculated eigen-solutions. It is shown that the extracted average quadrupole moments show a transitional behavior as a function of temperature and the inferred transitional temperature is shown to vary with angular-momentum. The quadrupole deformation of the individual eigen-states is also analyzed.
Energy Technology Data Exchange (ETDEWEB)
Fedoseyev, V G [Institute of Physics, University of Tartu, Riia 142, 51014 Tartu (Estonia)], E-mail: fedo@fi.tartu.ee
2008-12-19
The transformation of the orbital angular momentum (OAM) at the reflection and transmission of a paraxial light beam on a plane interface of two isotropic transparent media is considered. The unitary formula for the intrinsic OAMs of the incident, reflected and transmitted beams is derived. The processes of the change of the intrinsic OAM at reflection and transmission, and the appearance of the extrinsic OAMs, which are generated by the respective shifts of the centres of gravity of secondary beams, are analysed on the basis of the conservation laws.
International Nuclear Information System (INIS)
Previous studies have shown that glass displays extracted from mobile phones are suitable as emergency dosimeters in case of an accidental radiation overexposure using the thermoluminescence (TL) method. So far these studies have focused only on recovering the absorbed dose to the material. However, dose in air or dose to the victim carrying the device might be significantly different. Therefore the aim of this work was to investigate photon energy dependence and angular response of glass display used in modern mobile phones. An over-response of about a factor of five is observed for low photon energies compared to the response to Cs-137 (662 keV) which is in reasonable agreement with calculated values mass energy-absorption coefficients of glass and air. Little variation in the energy dependence can be seen for glass displays coming from three different mobile phone models. The angular response for display glass is flat with regard to air kerma within the incident angle of ±60°, independent of the irradiation setup used (with a water phantom or with air kerma reference conditions). For incident angles of 90° the shielding effect of the mobile phones becomes important. With the dosimetric characterization of the photon energy and angular dependencies the absorbed dose in a glass display can be transferred to a reference air kerma dose and provides a useful option for retrospective accident dosimetry. - Highlights: • Determination of the photon energy dependence and angular response for display glass used as an accident dosimeter. • Over-response of about a factor of five for low photon energies. • Flat angular response within incident angles between ±60°
Angular dependence of coercivity with temperature in Co-based nanowires
Energy Technology Data Exchange (ETDEWEB)
Bran, C., E-mail: cristina.bran@icmm.csic.es [Institute of Materials Science of Madrid, CSIC, 28049 Madrid (Spain); Espejo, A.P. [Departamento de Física, Universidad de Santiago de Chile (USACH) and Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avenida Ecuador 3493, 9170124 Santiago (Chile); Palmero, E.M. [Institute of Materials Science of Madrid, CSIC, 28049 Madrid (Spain); Escrig, J. [Departamento de Física, Universidad de Santiago de Chile (USACH) and Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Avenida Ecuador 3493, 9170124 Santiago (Chile); Vázquez, M. [Institute of Materials Science of Madrid, CSIC, 28049 Madrid (Spain)
2015-12-15
The magnetic behavior of arrays of Co and CoFe nanowire arrays has been measured in the temperature range between 100 and 300 K. We have paid particular attention to the angular dependence of magnetic properties on the applied magnetic field orientation. The experimental angular dependence of coercivity has been modeled according to micromagnetic analytical calculations, and we found that the propagation of a transversal domain wall mode gives the best fitting with experimental observations. That reversal mode holds in the whole measuring temperature range, for nanowires with different diameters and crystalline structure. Moreover, the quantitative strength of the magnetocrystalline anisotropy and its magnetization easy axis are determined to depend on the crystalline structure and nanowires diameter. The evolution of the magnetocrystalline anisotropy with temperature for nanowires with different composition gives rise to an opposite evolution of coercivity with increasing temperature: it decreases for CoFe while it increases for Co nanowire arrays.
Angular dependence of coercivity with temperature in Co-based nanowires
International Nuclear Information System (INIS)
The magnetic behavior of arrays of Co and CoFe nanowire arrays has been measured in the temperature range between 100 and 300 K. We have paid particular attention to the angular dependence of magnetic properties on the applied magnetic field orientation. The experimental angular dependence of coercivity has been modeled according to micromagnetic analytical calculations, and we found that the propagation of a transversal domain wall mode gives the best fitting with experimental observations. That reversal mode holds in the whole measuring temperature range, for nanowires with different diameters and crystalline structure. Moreover, the quantitative strength of the magnetocrystalline anisotropy and its magnetization easy axis are determined to depend on the crystalline structure and nanowires diameter. The evolution of the magnetocrystalline anisotropy with temperature for nanowires with different composition gives rise to an opposite evolution of coercivity with increasing temperature: it decreases for CoFe while it increases for Co nanowire arrays
Energy and angular dependence of the personal dosemeter in use at ITN-DPRSN
International Nuclear Information System (INIS)
In this paper the characterization of the dosimetry system and of the personal dosemeter in terms of the stability of the reader calibration factors and of the linearity of the response for the 137Cs reference radiation is presented. The energy and angular dependence of the whole body dosemeter are also shown. The energy dependence was determined performing irradiations with the X-ray narrow series beams N30, N40, N60, N80, N100, N120 and with the gamma reference radiations of 137Cs and 60Co [ISO 4037-1, 1996. X and Gamma Reference Radiation for Calibrating Dosemeters and Doserate Meters and for Determining Their Response as a Function of Photon Energy-Part 1: Radiation Characteristics and Production Methods. International Organization for Standardization, Geneva] in terms of Hp(10) incident on the ISO water slab phantom. The angular dependence of the dosemeter was determined for the angles 0 deg., ±20 deg., ±40 deg. and ±60 deg. with normal using the above mentioned radiation fields. All irradiations were performed at the Laboratorio de Metrologia das Radiacoes lonizantes of ITN-DPRSN. The experiments presented in this paper show the thermoluminescence dosimetry (TLD) system is stable and presents a linear behaviour over and extended dose range. The measurements allowed the determination of the energy dependence at normal incidence and of the angular dependence of the dosemeter currently in use. Further studies are being carried out in order to implement correction factors for supralinearity and low energy measurements
Angular-dependent Raman study of a- and s-plane InN
International Nuclear Information System (INIS)
Angular-dependent polarized Raman spectroscopy was utilized to study nonpolar a-plane (11¯20) and semipolar s-plane (101¯1) InN epilayers. The intensity dependence of the Raman peaks assigned to the vibrational modes A1(TO), E1(TO), and E2h on the angle ψ that corresponds to rotation around the growth axis, is very well reproduced by using expressions taking into account the corresponding Raman tensors and the experimental geometry, providing thus a reliable technique towards assessing the sample quality. The s- and a-plane InN epilayers grown on nitridated r-plane sapphire (Al2O3) exhibit good crystalline quality as deduced from the excellent fitting of the experimental angle-dependent peak intensities to the theoretical expressions as well as from the small width of the Raman peaks. On the contrary, in the case of the s-plane epilayer grown on non-nitridated r-plane sapphire, fitting of the angular dependence is much worse and can be modeled only by considering the presence of two structural modifications, rotated so as their c-axes are almost perpendicular to each other. Although the presence of the second variant is verified by transmission electron and atomic force microscopies, angular dependent Raman spectroscopy offers a non-destructive and quick way for its quantification. Rapid thermal annealing of this sample did not affect the angular dependence of the peak intensities. The shift of the E1(TO) and E2h Raman peaks was used for the estimation of the strain state of the samples
Q- and Z-dependence of angular momentum transfer in deeply inelastic collisions of 86Kr with 209Bi
International Nuclear Information System (INIS)
The dependence of the in-plane and out-of-plane angular correlations of fragments from fissioning heavy products on the kinetic energy and Z of the light reaction partner have been measured. From the dependence of the angular correlations on Q-value and hence energy loss, together with existing data from which the total angular-integrated cross section as a function of energy loss can be extracted, the dependence of the angular momentum transferred to the heavy product on the initial orbital angular momentum or impact parameter has been determined. The resulting dependence is qualitatively consistent with the sticking limit for a reaction intermediate of touching deformed fragments. More specific nuclear models generally underestimate the angular momentum transfer, although the one-body proximity-friction model accounts for the major fraction of the angular momentum transfer. A recent model incorporating both one-body proximity friction and collective excitations accounts quite well for the observed angular momentum transfer. The Z-dependence of the anisotropy shows the importance of angular momentum fractionation for the less probable events, where the Z of the fissioning system is appreciably less than that of the target. The transferred angular momentum is shown to be fairly strongly aligned along the perpendicular to the reaction plane, with alignment values of 0.6 to 0.8. The component of angular momentum not along the perpendicular to the reaction plane is found to be primarily oriented perpendicular rather than parallel to the recoil directions. The absolute fission probabilities are found to be qualitatively consistent with J-dependent calculations using the J-values deduced from the angular correlations. (Auth.)
Angular dependence of thermoluminescent dosemeters for gamma and beta radiation in nuclear medicine
International Nuclear Information System (INIS)
The gamma and beta radiation sources are widely used in Nuclear Medicine for diagnostic and therapeutic purposes. Workers of these services receive dose of whole body and end due to the activities of the therapeutic dose preparation and testing, administration radiopharmaceuticals and obtention of image. Hands receive higher doses than other parts of the body. Currently the individual monitoring for the gamma radiation is already well established; However, the determination of the dose due to beta radiation still faces some difficulties. In this work it was studied the angular dependence of thermoluminescent dosemeters detectors in beams of gamma and beta radiation. Detectors of CaSO4:Dy + Teflon produced at IPEN - the Brazilian Institute for Nuclear and Energy Researches - were used. The angular dependence was studied varying the angle between 0 and 180 deg. The results obtained proved to be suitable for use in individual monitoring of workers exposed to beta and gamma radiation
Oliveira, A. B.; Rodriguez-Suarez, R. L.; Michea, S.; Vega, H.; Azevedo, A.; Rezende, S. M.; Aliaga, C.; Denardin, J.
2014-07-01
The angular dependence of the hysteresis shift has been investigated in ferromagnetic/antiferromagnetic (NiFe/IrMn) bilayers grown by oblique deposition under the influence of a static magnetic field applied perpendicular to the uniaxial anisotropy direction induced during the growth process. It was found that at low oblique deposition angles, the unidirectional anisotropy field is much greater than the uniaxial anisotropy field and the corresponding anisotropies directions are noncollinear. In these conditions, the angular dependence of the hysteresis loop shift exhibits the well know cosine like shape but demanding a phase shift. Contrary to this, at high oblique deposition angle (70°), the uniaxial anisotropy plays the fundamental role and the anisotropies directions are collinear. In this case, the exchange bias displays a jump phenomenon. The numerical calculations are consistent with the experimental data obtained from magneto-optical Kerr effect and ferromagnetic resonance.
Yu, Shixing; Li, Long; Shi, Guangming; Zhu, Cheng; Zhou, Xiaoxiao; Shi, Yan
2016-03-01
In this paper, a reflective metasurface is designed, fabricated, and experimentally demonstrated to generate an orbital angular momentum (OAM) vortex wave in radio frequency domain. Theoretical formula of phase-shift distribution is deduced and used to design the metasurface producing vortex radio waves. The prototype of a practical configuration is designed, fabricated, and measured to validate the theoretical analysis at 5.8 GHz. The simulated and experimental results verify that the vortex waves with different OAM mode numbers can be flexibly generated by using sub-wavelength reflective metasurfaces. The proposed method and metasurface pave a way to generate the OAM vortex waves for radio and microwave wireless communication applications.
Angular dependence of recoil proton polarization in high-energy gamma d to p n
International Nuclear Information System (INIS)
We measured the angular dependence of the three recoil proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily.. Transverse polarizations are not well described, but suggest isovector dominance
WIND TURBINE SIMULATION FOR TIME-DEPENDENT ANGULAR VELOCITY, TORQUE, AND POWER
YONGHO LEE
2013-01-01
Albeit the prediction of time-dependent properties of wind turbines is not required for common applications, such time-varying properties may play an important role during transient operations occurring due to various reasons. Unlike the conventional numerical simulations of wind turbine rotations that fix the angular velocity to an assumed value, the present work numerically simulates the time-varying turbine rotation in both unsteady and quasi-steady operation regimes, without specifying th...
An Extended Greuling-Goertzel Approximation with a Pn-Approximation in the Angular Dependence
International Nuclear Information System (INIS)
The slowing-down spectrum has been calculated for different media. It is given in slab geometry as a function of space at the beginning of the epithermal region (10 eV). The angular dependence is also shown. The basic method is that given by E. Greuling, F. Clark and G. Goertzel in a NDA report, but in this report it is permissible to include more terms in the legendre expansion
International Nuclear Information System (INIS)
The first-order neutron transport equation is solved by the least-squares finite element method based on the discrete ordinates discretization. The angular dependent rebalance (ADR) acceleration arithmetic and its extrapolate method are given. The numerical results of some benchmark problems demonstrate that the arithmetic can shorten the CPU time to 34% ∼ 50% and it is effective even for the strong scattering problem. (authors)
Angular dependence of recoil proton polarization in high-energy \\gamma d \\to p n
Energy Technology Data Exchange (ETDEWEB)
X. Jiang; J. Arrington; F. Benmokhtar; A. Camsonne; J.P. Chen; S. Choi; E. Chudakov; F. Cusanno; A. Deur; D. Dutta; F. Garibaldi; D. Gaskell; O. Gayou; R. Gilman; C. Glashauser; D. Hamilton; O. Hansen; D.W. Higinbotham; R.J. Holt; C.W. de Jager; M.K. Jones; L.J. Kaufman; E.R. Kinney; K. Kramer; L. Lagamba; R. de Leo; J. Lerose; D. Lhuillier; R. Lindgren; N. Liyanage; K. McCormick; Z.-E. Meziani; R. Michaels; B. Moffit; P. Monaghan; S. Nanda; K.D. Paschke; C.F. Perdrisat; V. Punjabi; I.A. Qattan; R.D. Ransome; P.E. Reimer; B. Reitz; A. Saha; E.C. Schulte; R. Sheyor; K. Slifer; P. Solvignon; V. Sulkosky; G.M. Urciuoli; E. Voutier; K. Wang; K. Wijesooriya; B. Wojtsekhowski; L. Zhu
2007-02-26
We measured the angular dependence of the three recoil proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily.. Transverse polarizations are not well described, but suggest isovector dominance.
Angular dependence of recoil proton polarization in high-energy \\gamma d \\to p n
Jiang, X; Benmokhtar, F; Camsonne, A; Chen, J P; Choi, S; Chudakov, E; Cusanno, F; De Jager, C W; De Leo, R; Deur, A; Dutta, D; Garibaldi, F; Gaskell, D; Gayou, O; Gilman, R; Glashauser, C; Hamilton, D; Hansen, O; Higinbotham, D W; Holt, R J; Jones, M K; Kaufman, L J; Kinney, E R; Krämer, K; Lagamba, L; Lerose, J; Lhuillier, D; Lindgren, R; Liyanage, N; McCormick, K; Meziani, Z E; Michaels, R; Moffit, B; Monaghan, P; Nanda, S; Paschke, K D; Perdrisat, C F; Punjabi, V; Qattan, I A; Ransome, R D; Reimer, P E; Reitz, B; Saha, A; Schulte, E C; Sheyor, R; Slifer, K J; Solvignon, P; Sulkosky, V; Urciuoli, G M; Voutier, E; Wang, K; Wijesooriya, K; Wojtsekhowski, B; Zhu, L
2007-01-01
We measured the angular dependence of the three recoil proton polarization components in two-body photodisintegration of the deuteron at a photon energy of 2 GeV. These new data provide a benchmark for calculations based on quantum chromodynamics. Two of the five existing models have made predictions of polarization observables. Both explain the longitudinal polarization transfer satisfactorily.. Transverse polarizations are not well described, but suggest isovector dominance.
Angular Dependence of 3 Omega 0/2 Spectra from Laser-produced Plasmas
International Nuclear Information System (INIS)
Scattered light at three-halves of the incident laser frequency from solid targets is observed at five different angles. When the incident laser intensity is low enough, rescattering of two plasmon decay (TPD) instability electron plasma waves by ion acoustic waves is not significant. In this regime, Thomson scattering measurements of the electron temperature and the plasma flow velocity allow quantitative comparison of the angular dependence of the spectrum to theory
Palov, A. P.; Mankelevich, Yu A.; Rakhimova, T. V.; Baklanov, M. R.
2016-03-01
Ion-stimulated etching of dielectrics in radio frequency plasma results in positive charging of a trench bottom because of the significant difference in the angular distribution functions of ions and electrons. They are anisotropic for ions and quasi-isotropic for electrons. The charging leads to a decrease in the energy of the ions bombarding the trench bottom and to undesirable sputtering of the walls near the trench bottom because of the curving of the ion trajectories. This process is normally investigated by Monte Carlo methods in the absence of experimental data. In this paper the analytical dependence of the ion flux bombarding the trench bottom on a trench aspect ratio and ion angular distribution function is obtained. Numerical calculations of the electric potential on the trench bottom for a set of trench aspect ratios and angles of the ion angular distribution function were performed based on a Monte Carlo method to demonstrate the ion flux and electric potential correlated well with each other. The proposed formula for an ion flux is suggested to be helpful for analyzing charging the trenches with different aspect ratios in plasma with an arbitrary angular ion distribution function.
Liu, Hongxue; Lu, Jiwei; Wolf, Stuart; Hodgson, Jim; Rutgers, Maarten
2013-01-01
We demonstrate a versatile variable field module (VFM) with capability of both field and angular dependent measurements up to 1800 Oe for scanning probe system. The magnetic field strength is changed by adjusting the distance between a rare earth magnet and the probe tip and is monitored in-situ by a built-in Hall sensor. Rotating the magnet allows the field vector to change from the horizontal to vertical direction and makes it possible to do angular dependent measurements. The capability of the VFM system is demonstrated by degaussing a floppy disk media with increasing magnetic field. Angular dependent measurements clearly show the evolution of magnetic domain structures, with a completely reversible magnetic force microscopy phase contrast observed when the magnetic field is rotated by 180{\\deg}. A further demonstration of out-of-plane and in-plane magnetic switching of CoFe2O4 pillars in CoFe2O4-BiFeO3 nanocomposites was presented and discussed.
WIND TURBINE SIMULATION FOR TIME-DEPENDENT ANGULAR VELOCITY, TORQUE, AND POWER
Directory of Open Access Journals (Sweden)
YONGHO LEE
2013-02-01
Full Text Available Albeit the prediction of time-dependent properties of wind turbines is not required for common applications, such time-varying properties may play an important role during transient operations occurring due to various reasons. Unlike the conventional numerical simulations of wind turbine rotations that fix the angular velocity to an assumed value, the present work numerically simulates the time-varying turbine rotation in both unsteady and quasi-steady operation regimes, without specifying the angular velocity of the turbine a priori, but by calculating the actual time-dependent angular velocity and aerodynamic torque along with other properties in the course of simulation. In the present work, successful results obtained by an efficient computational fluid dynamics technique are shown, as a demonstration, for a vertical-axis wind turbine with a two-dimensionalSavonius rotor, and the cycle-averaged output powers are compared with experimental power curves and a theory developed on the basis of experimental observations.
Angular correlations in multi-jet final states from k perpendicularto -dependent parton showers
International Nuclear Information System (INIS)
Angular correlations in final states with multiple hadronic jets have recently been measured in DIS production at HERA. Next-to-leading-order QCD results for these observables turn out to be affected by sizeable theoretical uncertainties in the kinematic region of the data. We investigate the effects of multiple QCD radiation at higher order using parton-shower methods based on transverse-momentum dependent parton distributions and matrix elements. We observe that significant contributions to the angular correlations measured in three-jet production arise from regions in which transverse momenta in the initial-state shower are not ordered. We present Monte Carlo results for azimuthal two-jet and three-jet distributions, for jet multiplicities and for correlations in the transverse-momentum imbalance between the leading jets. We discuss the comparison with experimental data. (orig.)
Study of angular dependences of ion component parameters in CO2-laser-produced plasma
International Nuclear Information System (INIS)
CO2-laser-produced plasma ion component parameters were studied for aluminium and lead targets at laser intensity of P = 4x1013 W cm-2 and pulse duration of τ = 15 ns experimentally and numerically. Angular dependences of ion number density for different charge states, average velocity and its spread were measured by time-of-flight method. Ion charge state distribution shows high-charge and low-charge state groups at normal expansion direction. Ions in these groups have different average expansion velocity and longitudinal velocity spread. Angular distribution of high-charge states is narrower than that of the low-charge state ion group, maximum yield of low-charge states occur at some angle from normal. For Al target results show similar trends as for Pb target, but simulations have indicated that the effect of laser ponderomotive force is more pronounced in this case
Angular dependence of OSL commercial detectors in standard beta radiation beams
International Nuclear Information System (INIS)
Full text: Optical stimulated luminescence (OSL) is a very successful dosimetry technique, in particular using the Al2O3:C crystals as dosimeter. This detector has become the main OSL material as a personal dosimeter. Commercial dosimeters of Al2O3:C have been developed and tested; however, most of the tests have been performed with gamma beams. Beta radiation dosimetry might be performed with Al2O3:C detectors, if the crystals are sufficient thin to avoid the radiation attenuation. The dosimeter thickness is also important to allow a satisfactory accuracy of the measured dose, despite the incidence radiation angle or the beta energy. Previous studies show that the Al2O3:C dosimeters present a very high energy dependence that can be minimized by using filters. This work aims to compare the angular dependence of commercial Al2O3:C dosimeters with and without the filters used to minimize the beta energy dependence of Al2O3:C, when the detectors were exposed to standard beta beams. The beta irradiations of the OSL detectors were performed using the beta secondary standard system of the Calibration Laboratory at IPEN, with 90Sr + 90Y, 85Kr and 147Pm sources, manufactured by Buchler GmbH and Co, Germany, calibrated by the primary standard laboratory Physikalisch-Technische Bundesanstalt (PTB), Germany. The OSL measurements were evaluated using a microStar reader and software of Landauer. The angular dependence was determined by using a goniometer. The incident radiation angle was varied from 0 deg to 180 deg. The results show that that the angular dependence curves present similar behavior, despite the use of filters
Azzam, R M A
2015-12-01
Conditions for achieving equal and opposite angular deflections of a light beam by reflection and refraction at an air-dielectric boundary are determined. Such angularly symmetric beam splitting (ASBS) is possible only if the angle of incidence is >60° by exactly one third of the angle of refraction. This simple law, plus Snell's law, leads to several analytical results that clarify all aspects of this phenomenon. In particular, it is shown that the intensities of the two symmetrically deflected beams can be equalized by proper choice of the prism refractive index and the azimuth of incident linearly polarized light. ASBS enables a geometrically attractive layout of optical systems that employ multiple prism beam splitters. PMID:26831398
Gaus, Michael; Jin, Haiyun; Demapan, Darren; Christensen, Anders S; Goyal, Puja; Elstner, Marcus; Cui, Qiang
2015-09-01
We report the parametrization of a density functional tight binding method (DFTB3) for copper in a spin-polarized formulation. The parametrization is consistent with the framework of 3OB for main group elements (ONCHPS) and can be readily used for biological applications that involve copper proteins/peptides. The key to our parametrization is to introduce orbital angular momentum dependence of the Hubbard parameter and its charge derivative, thus allowing the 3d and 4s orbitals to adopt different sizes and responses to the change of charge state. The parametrization has been tested by applying to a fairly broad set of molecules of biological relevance, and the properties of interest include optimized geometries, ligand binding energies, and ligand proton affinities. Compared to the reference QM level (B3LYP/aug-cc-pVTZ, which is shown here to be similar to the B97-1 and CCSD(T) results, in terms of many properties of interest for a set of small copper containing molecules), our parametrization generally gives reliable structural properties for both Cu(I) and Cu(II) compounds, although several exceptions are also noted. For energetics, the results are more accurate for neutral ligands than for charged ligands, likely reflecting the minimal basis limitation of DFTB3; the results generally outperform NDDO based methods such as PM6 and even PBE with the 6-31+G(d,p) basis. For all ligand types, single-point B3LYP calculations at DFTB3 geometries give results very close (∼1-2 kcal/mol) to the reference B3LYP values, highlighting the consistency between DFTB3 and B3LYP structures. Possible further developments of the DFTB3 model for a better treatment of transition-metal ions are also discussed. In the current form, our first generation of DFTB3 copper model is expected to be particularly valuable as a method that drives sampling in systems that feature a dynamical copper binding site. PMID:26575916
On the angular dependence of the photoemission time delay in helium
Ivanov, I A; Lindroth, E; Kheifets, A S
2016-01-01
We investigate an angular dependence of the photoemission time delay in helium as measured by the RABBITT (Reconstruction of Attosecond Beating By Interference of Two-photon Transitions) technique. The measured time delay $ \\tau_a=\\tau_W+\\tau_{cc} $ contains two distinct components: the Wigner time delay $\\tau_W$ and the continuum-continuum CC) correction $\\tau_{cc}$. In the case of helium with only one $1s\\to Ep$ photoemission channel, the Wigner time delay $\\tau_W$ does not depend on the photoelectron detection angle relative to the polarization vector. However, the CC correction $\\tau_{cc}$ shows a noticeable angular dependence. We illustrate these findings by performing two sets of calculations. In the first set, we solve the time-dependent Schr\\"odinger equation for the helium atom ionized by an attosecond pulse train and probed by an IR pulse. In the second approach, we employ the lowest order perturbation theory which describes absorption of the XUV and IR photons. Both calculations produce close resul...
XFEL OSCILLATOR SIMULATION INCLUDING ANGLE-DEPENDENT CRYSTAL REFLECTIVITY
International Nuclear Information System (INIS)
The oscillator package within the GINGER FEL simulation code has now been extended to include angle-dependent reflectivity properties of Bragg crystals. Previously, the package was modified to include frequencydependent reflectivity in order to model x-ray FEL oscillators from start-up from shot noise through to saturation. We present a summary of the algorithms used for modeling the crystal reflectivity and radiation propagation outside the undulator, discussing various numerical issues relevant to the domain of high Fresnel number and efficient Hankel transforms. We give some sample XFEL-O simulation results obtained with the angle-dependent reflectivity model, with particular attention directed to the longitudinal and transverse coherence of the radiation output.
Complete and incomplete jump phenomenon in the angular dependence of the noncollinear exchange bias
International Nuclear Information System (INIS)
The angular dependence of the exchange bias (ADEB) has been investigated in detail for ferromagnetic/antiferromagnetic bilayers with noncollinear uniaxial and unidirectional anisotropies. Two different types of the jump phenomenon, complete and incomplete jump phenomena, have been proved to occur at the orientations of the intrinsic easy and hard axes. A special position for the intrinsic easy and hard axes, which makes an angular deviation of 58.2826° from the uniaixal anisotropy axis, has been deduced by analyzing the magnetization reversal processes based on the principle of minimal energy. When the angular deviation of the intrinsic easy or hard axis from the uniaxial anisotropy axis is above the critical value of 58.2826°, the complete jump phenomenon will be shown in the ADEB. On the contrary, once this angular deviation is not more than 58.2826°, the incomplete jump phenomenon occurs, and the critical angle will be observed in the ADEB. The determined formula of the critical angle is also obtained by analyzing the magnetization reversal processes. Additionally, the extreme value problem of the exchange bias is studied in this paper. The coercivity always reaches its maximum value when the external field points along the intrinsic easy axis. The minimal coercivity occurs at the orientation of the critical angle. However, there are two orientations of the applied field to gain the maximal exchange bias field. One is the direction of the intrinsic hard axis when the complete jump phenomenon occurs at this orientation. The other one is the orientation of the critical angle under the condition that the incomplete jump phenomenon takes place at the intrinsic hard axis. The numerical calculations are consistent with the involved experimental observations, indicating that our method is valid to study the ADEB and it is an effective method to achieve the maximal exchange bias field as well as the maximal or minimal coercivity by adjusting the orientation of the
Equivalence between deep energy-dependent and shallow angular momentum dependent potentials
International Nuclear Information System (INIS)
Recently Baye showed that supersymmetry can be applied to determine a shallow l-dependent potential phase equivalent to a deep potential, assumed to be energy-independent and have Panli forbidden states (PFS), for α-α scattering. The PFS are eliminated by this procedure. Such deep potentials are generated as equivalent local potentials (ELP) to the Resonating Group Model (RGM) and are generally energy-dependent. To eliminate this E-dependence as required for the application of Baye's method, l-dependent, but E-independent, deep local potentials were generated by the exact inversion method of Marchenko. Subsequently, the supersymmetric method was used to eliminate the PFS, ensuring that the generalized Levinson theorem is satisfied. As an example, the method was applied to the simple model of two dineutrons scattering in the RGM, where the deep ELP of Horiuchi has a substantial energy-dependence and one PFS only for l=O. 16 refs., 5 figs
Yu, Shixing; Li, Long; Shi, Guangming
2016-08-01
A metasurface, which is composed of printed cross-dipole elements with different arm lengths, is designed, fabricated, and experimentally demonstrated to generate orbital angular momentum (OAM) vortex waves of dual polarizations and dual modes in the radio frequency domain simultaneously. The prototype of a practical metasurface is fabricated and measured to validate the results of theoretical analysis and design at 5.8 GHz. Numerical and experimental results verify that vortex waves with dual OAM modes and dual polarizations can be flexibly generated by using a reflective metasurface. The proposed method paves a way to generate diverse OAM vortex waves for radio frequency and microwave wireless communication applications.
Effect of Angular Velocity on Sensors Based on Morphology Dependent Resonances
Directory of Open Access Journals (Sweden)
Amir R. Ali
2014-04-01
Full Text Available We carried out an analysis to investigate the morphology dependent optical resonances shift (MDR of a rotating spherical resonator. The spinning resonator experiences an elastic deformation due to the centrifugal force acting on it, leading to a shift in its MDR. Experiments are also carried out to demonstrate the MDR shifts of a spinning polydimethylsiloxane (PDMS microsphere. The experimental results agree well with the analytical prediction. These studies demonstrated that spinning sensor based on MDR may experience sufficient shift in the optical resonances, therefore interfering with its desirable operational sensor design. Also the results show that angular velocity sensors could be designed using this principle.
Effect of angular velocity on sensors based on morphology dependent resonances.
Ali, Amir R; Ioppolo, Tindaro
2014-01-01
We carried out an analysis to investigate the morphology dependent optical resonances shift (MDR) of a rotating spherical resonator. The spinning resonator experiences an elastic deformation due to the centrifugal force acting on it, leading to a shift in its MDR. Experiments are also carried out to demonstrate the MDR shifts of a spinning polydimethylsiloxane (PDMS) microsphere. The experimental results agree well with the analytical prediction. These studies demonstrated that spinning sensor based on MDR may experience sufficient shift in the optical resonances, therefore interfering with its desirable operational sensor design. Also the results show that angular velocity sensors could be designed using this principle. PMID:24759108
Measuring the angular dependence of betatron x-ray spectra in a laser-wakefield accelerator
Energy Technology Data Exchange (ETDEWEB)
Albert, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pollock, B. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Shaw, J. L. [Univ. of California, Los Angeles, CA (United States); Marsh, K. A. [Univ. of California, Los Angeles, CA (United States); Ralph, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Chen, Y. -H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Alessi, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Pak, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Clayton, C. E. [Univ. of California, Los Angeles, CA (United States); Glenzer, S. H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Joshi, C. [Univ. of California, Los Angeles, CA (United States)
2014-07-22
This paper presents a new technique to measure the angular dependence of betatron x-ray spectra in a laser-wakefield accelerator. Measurements are performed with a stacked image plates spectrometer, capable of detecting broadband x-ray radiation up to 1 MeV. It can provide measurements of the betatron x-ray spectrum at any angle of observation (within a 40 mrad cone) and of the beam profile. A detailed description of our data analysis is given, along with comparison for several shots. As a result, these measurements provide useful information on the dynamics of the electrons are they are accelerated and wiggled by the wakefield.
Angular-dependent interatomic potential for the aluminum-hydrogen system
Apostol, F.; Mishin, Y.
2010-10-01
We report on the development of an angular-dependent interatomic potential for hydrogen and the aluminum-hydrogen system. The potential reproduces properties of diatomic hydrogen gas, accurate solution energies of hydrogen atoms in crystalline Al, the energetic preference of the tetrahedral interstitial site occupation over octahedral, the hydrogen diffusion barrier in Al, and a number of other properties. Some of the results predicted by the potential have been tested by molecular dynamics simulations. It is suggested that the new potential can be used in atomistic simulations of the effect of dissolved hydrogen on deformation and fracture of Al, a problem which is relevant to hydrogen-induced degradation of Al alloys.
International Nuclear Information System (INIS)
A study of the behavior of reflected gamma radiation inside a spherical, steel-lined, concrete-walled room has been conducted using the discrete ordinates S/sub n/ code ANISN. The purpose of this study was to investigate the effect of the scattered radiation on the calculated gamma dose rate expected following a severe accident inside a reactor containment building. This paper presents an analysis of the angular, radial, and energy dependence of the scattered fluence. An empirical approximation for the radial dependence of the contribution of the scattered radiation is presented. Major conclusions are that the total scattered radiation is approximately twice the product of the incident fluence and the albedo near the wall, and that the presence of a steel liner significantly reduces the scattered radiation. Generally, good agreement was observed between the discrete ordinates results and published Monte Carlo data
Angular dependence of the coercivity and remanence of ordered arrays of Co nanowires
International Nuclear Information System (INIS)
The angular dependence of the coercivity and remanence of ordered hexagonal arrays of Co nanowires prepared using anodic aluminum oxide templates was investigated. The experimental evolution of coercivity as a function of the angle, in which the external field is applied, is interpreted considering micromagnetic simulations. Depending on the angle between the axis of the wire and the applied magnetic field direction our results show that the magnetization reversal mode changes from vortex to a transverse domain wall. Besides, we observed that the dipolar interactions cause a reduction in coercive fields, mainly in the direction of easy magnetization of the nanowires. Good agreement between numerical and experimental data is obtained. - Highlights: ► Angular dependence of the coercivity and remanence of Co nanowire arrays. ► Results show that the magnetization reversal mode changes from vortex to a transverse domain wall. ► Dipolar interactions cause a reduction in coercive fields, which is the strongest in the direction of easy magnetization of the nanowire.
Imaging frequency-dependent reflectivity from synthetic-aperture radar
International Nuclear Information System (INIS)
This paper develops a method for using a synthetic-aperture radar system to obtain not only a spatial image of a scene but also the localized frequency dependence of the scene reflectivity. In other words, for each image pixel, we also obtain a plot of the frequency dependence of the reflectivity in that pixel. We present a method for extracting this information from the data, and also a formula that characterizes the performance of this imaging system. We conclude with some simulations suggesting that the method may be promising. (paper)
Angular dependence of the FMR linewidth and the anisotropy of the relaxation time in iron garnets
Kobelev, A. V.; Shvachko, Yu. N.; Ustinov, V. V.
2016-01-01
This work is devoted to the problem of extracting the contribution of the anisotropy of relaxation to the angular dependence of the FMR linewidth and to the opportunity of determining the values of the parameters of relaxation. The results of the FMR study of films based on the yttrium iron garnet prepared by the method of liquid-phase epitaxy are given. The orientational dependence of the linewidth has been calculated using the traditional method of measuring an FMR spectrum and a method based on scanning at an angle to the resonance field for obtaining the minimum linewidth. A model for calculating the linewidth has been proposed that takes into account the anisotropy of the relaxation term in the equation of motion of the magnetic moment. The model leads to a dependence that agrees well with the experimental data, which makes it possible to state that the anisotropy of relaxation most likely takes place in the samples under consideration at the temperatures employed.
Angular dependence of electron emission induced by grazing-ion surface collisions
Gravielle, M. S.; Miraglia, J. E.; Otero, G. G.; Sánchez, E. A.; Grizzi, O.
2004-04-01
In this work, electron emission spectra produced by impact of fast protons on Al(111) surfaces are theoretically and experimentally studied. Contributions coming from the different electronic sources of the metal—atomic inner shells and valence band—are analyzed as a function of the angle of electron emission. In the forward direction, the inner-shell ionization process is the dominant mechanism. The valence emission, instead, becomes important when the ejection angle is separated from the specular-reflection direction. In both angular regions, theoretical and experimental values are in reasonable agreement. The energy shift and broadening of the convoy electron peak at glancing observation angles are well described by the present model, which takes into account the influence of the induced surface field on the ionized electron.
Matsuura, Yutaka; Kitai, Nobuyuki; Hosokawa, Seiichi; Hoshijima, Jun
2016-08-01
The relation of the coercive force decrease ratio (CFDR) and the angular dependence of the coercive force (ADCF) of ferrite magnets and their temperature properties were investigated. When we compared that against the angle of the magnetization reverse area obtained from these calculation results, which was obtained from the Gaussian distribution of the grain alignment and the postulation that every grain follows the Kondorskii law or the 1/cos θ law, and against the angle of the reverse magnetization area calculated from the experiment CFDR data of these magnets, it was found that this latter expanded at room temperature, to 36° from the calculated angle, for magnet with α=0.96. It was also found that, as temperature increased from room temperature to 413 K, the angle of the reverse magnetization area of ferrite magnets obtained from the experiment data expanded from 36° to 41°. When we apply these results to the temperature properties of ADCF, it seems that the calculated ADCF could qualitatively and reasonably explain these temperature properties, even though the difference between the calculated angular dependence and the experimental data still exists in the high angle range. These results strongly suggest that the coercive force of these magnets is determined by the magnetic domain wall motion. The magnetic domain walls are strongly pinned at tilted grains, and when the domain walls are de-pinned from their pinning sites, the coercive force is determined.
Reflectance dependence of polytetrafluoroethylene on thickness for xenon scintillation light
Haefner, Jonathan; Arthurs, Maris; Batista, Elizabeth; Morton, Daniel; Okunawo, Matt; Pushkin, Kirill; Sander, Aaron; Wang, Yuhan; Lorenzon, Wolfgang
2016-01-01
Many rare event searches including dark matter direct detection and neutrinoless double beta decay experiments take advantage of the high VUV reflective surfaces made from polytetrafluoroethylene (PTFE) reflector materials to achieve high light collection efficiency in their detectors. As the detectors have grown in size over the past decade, there has also been an increased need for ever thinner detector walls without significant loss in reflectance to reduce dead volumes around active noble liquids, outgassing, and potential backgrounds. We report on the experimental results to measure the dependence of the reflectance on thickness of two PTFE samples at wavelengths near 178 nm. No change in reflectance was observed as the thickness of a cylindrically shaped PTFE vessel immersed in liquid xenon was varied between 1 mm to 9.5 mm.
Crack depth profiling using guided wave angle dependent reflectivity
International Nuclear Information System (INIS)
Tomographic corrosion monitoring techniques have been developed, using two rings of sensors around the circumference of a pipe. This technique is capable of providing a detailed wall thickness map, however this might not be the only type of structural damage. Therefore this concept is expanded to detect and size cracks and small corrosion defects like root corrosion. The expanded concept uses two arrays of guided-wave transducers, collecting both reflection and transmission data. The data is processed such that the angle-dependent reflectivity is obtained without using a baseline signal of a defect-free situation. The angle-dependent reflectivity is the input of an inversion scheme that calculates a crack depth profile. From this profile, the depth and length of the crack can be determined. Preliminary experiments show encouraging results. The depth sizing accuracy is in the order of 0.5 mm
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Radiation management departments place more emphasis on the accuracy of measurements than on the increase in the average dose and personal exposure dose from the use of radiation equipment and radioactive isotopes. Although current measurements are taken using devices, such as film badge dosimeters, pocket dosimeters and thermoluminescent dosimeters (TLDs), this study compared the angular dependence between the widely used TLDs and photoluminescent dosimeter (PLDs) in order to present primary data and evaluate the utility of PLD as a new dosimeter device. For X-ray fluoroscopy, a whole body phantom was placed on a table with a setting for the G-I technical factors fixed at a range of approximately 40 cm with a range of ±90o at an interval scale of 15o from the center location of an average radiological worker for PLDs (GD-450) and TLDs (Carot). This process was repeated 10 times, and at each time, the cumulative dosage was interpreted from 130 dosimeters using TLDs (UD-710R, Panasonic) and PLDs (FGD-650). The TLD and PLD showed a 52% and 23% decrease in the depth dosage from 0o to -90o, respectively. Therefore, PLDs have a lower angular dependence than TLDs.
Energy Technology Data Exchange (ETDEWEB)
Dong, Kyung-Rae [Department of Radiological Technology, Gwangju Health College University (Korea, Republic of); Department of Nuclear Engineering, Chosun University (Korea, Republic of); Kweon, Dae Cheol [Department of Radiologic Science, Shin Heung College University (Korea, Republic of); Chung, Woon-Kwan, E-mail: wkchung@chosun.ac.kr [Department of Nuclear Engineering, Chosun University (Korea, Republic of); Goo, Eun-Hoe [Department of Diagnostic Radiology, Seoul National University Hospital (Korea, Republic of); Department of Physics, Soonchunhyang University (Korea, Republic of); Dieter, Kevin [Department of Physical Therapy, Gwangju Health College University (Korea, Republic of); Choe, Chong-Hwan [Department of White Memorial Medical Center (United States)
2011-02-15
Radiation management departments place more emphasis on the accuracy of measurements than on the increase in the average dose and personal exposure dose from the use of radiation equipment and radioactive isotopes. Although current measurements are taken using devices, such as film badge dosimeters, pocket dosimeters and thermoluminescent dosimeters (TLDs), this study compared the angular dependence between the widely used TLDs and photoluminescent dosimeter (PLDs) in order to present primary data and evaluate the utility of PLD as a new dosimeter device. For X-ray fluoroscopy, a whole body phantom was placed on a table with a setting for the G-I technical factors fixed at a range of approximately 40 cm with a range of {+-}90{sup o} at an interval scale of 15{sup o} from the center location of an average radiological worker for PLDs (GD-450) and TLDs (Carot). This process was repeated 10 times, and at each time, the cumulative dosage was interpreted from 130 dosimeters using TLDs (UD-710R, Panasonic) and PLDs (FGD-650). The TLD and PLD showed a 52% and 23% decrease in the depth dosage from 0{sup o} to -90{sup o}, respectively. Therefore, PLDs have a lower angular dependence than TLDs.
Angular dependence of depth doses in a tissue slab irradiated with monoenergetic photons
International Nuclear Information System (INIS)
This report presents dose equivalents from external photon irradiation, normalised to air kerma free in air, on the central axis of a cuboid slab of ICRU tissue for various depths, photon energies and angles of beam incidence. The data were calculated by a Monte Carlo method using an idealised planar parallel source of monoenergetic photons. The data presented here aim at facilitating the calibration of individual dosimeters; they provide also an estimate of the quantity 'personal dose equivalent' defined by the ICRU. A detailed evaluation of the dependence of the calculated conversion coefficients on depth in the slab, photon energy and angle of incidence is given. A comparison with published measured an calculated values of angular dependence factors is made. (orig.)
Paris-Mandoki, Asaf; Gorniaczyk, Hannes; Tresp, Christoph; Mirgorodskiy, Ivan; Hofferberth, Sebastian
2016-08-01
Förster resonances provide a highly flexible tool to tune both the strength and the angular shape of interactions between two Rydberg atoms. We give a detailed explanation about how Förster resonances can be found by searching through a large range of possible quantum number combinations. We apply our search method to SS, SD and DD pair states of 87Rb with principal quantum numbers from 30 to 100, taking into account the fine structure splitting of the Rydberg states. We find various strong resonances between atoms with a large difference in principal quantum numbers. We quantify the strength of these resonances by introducing a figure of merit {\\tilde{C}}3 which is independent of the magnetic quantum numbers and geometry to classify the resonances by interaction strength. We further predict to what extent excitation exchange is possible on different resonances and point out limitations of the coherent hopping process. Finally, we discuss the angular dependence of the dipole–dipole interaction and its tunability near resonances.
Paris-Mandoki, Asaf; Tresp, Christoph; Mirgorodskiy, Ivan; Hofferberth, Sebastian
2016-01-01
F\\"orster resonances provide a highly flexible tool to tune both the strength and the angular shape of interactions between two Rydberg atoms. We give a detailed explanation about how F\\"orster resonances can be found by searching through a large range of possible quantum number combinations. We apply our search method to $SS$, $SD$ and $DD$ pair states of $^{87}$Rb with principal quantum numbers from 30 to 100, taking into account the fine structure splitting of the Rydberg states. We find various strong resonances between atoms with a large difference in principal quantum numbers. We quantify the strength of these resonances by introducing a figure of merit $\\tilde C_3$ which is independent of the magnetic quantum number and geometry to classify the resonances by interaction strength. We further predict to what extent interaction exchange is possible on different resonances and point out limitations of the coherent hopping process. Finally, we discuss the angular dependence of the dipole-dipole interaction ...
Transverse shift of a beam with orbital angular momentum under reflection from a dielectric film
Kundikova, N D
2013-01-01
We present the results of numerical analysis of Gauss-Bessel beam reflection from a dielectric film under different angles of incidence. A transverse shift of the beam under the orbital momentum sign change is observed. The value of the shift is independent of the polarization state of the incident beam.
Frequency-dependent seismic reflection coefficient for discriminating gas reservoirs
International Nuclear Information System (INIS)
The asymptotic equation of wave propagation in fluid-saturated porous media is available for calculating the normal reflection coefficient within a seismic frequency band. This frequency-dependent reflection coefficient is expressed in terms of a dimensionless parameter ε, which is the product of the reservoir fluid mobility (i.e. inverse viscosity), fluid density and the frequency of the signal. In this paper, we apply this expression to the Xinchang gas field, China, where reservoirs are in super-tight sands with very low permeability. We demonstrate that the variation in the reflection coefficient at a gas–water contact as a transition zone within a sand formation is observable within the seismic frequency band. Then, we conduct seismic inversion to generate attributes which first indicate the existence of fluid (either gas or water), and then discriminate a gas reservoir from a water reservoir
Angular dependence study on dose distribution of MatriXX 2-D chamber array
International Nuclear Information System (INIS)
With the gantry angles of 0 degree 80 degree and 280 degree 360 degree (0 degree), the off axis distance (OAR) profiles curves of 6 MV X-ray were obtained by Monte Carlo simulation, 3-D water phantom measurement and MatriXX measurement. Comparing the three types of curves, we analyzed the angular dependence of MatriXX 2-D chamber array. The results revealed that the three types of curves agreed well with the gantry angles of 0 degree 60 degree and 300 degree 360 degree(0 degree). Curves and centre point dose on plane from Monte Carlo simulation differed obviously from those of MatriXX measurement in gantry angles of 70 degree 90 degree and 270 degree 290 degree. It is possible to verify the dose distribution of intensity modulated radiation therapy (IMRT) plan using the Multi-Gantry-Angle Composite (MGAC). (authors)
International Nuclear Information System (INIS)
The first-order neutron transport equation was solved by the least-squares finite element method based on the discrete ordinates discretization. For the traditional source iteration method is very slowly for the optically thick diffusive medium, sometime even divergent especially for the scattering ratio is close to unity, so the acceleration method should be proposed. There is only diffusive synthetical acceleration (DSA) for the discontinuous finite element method (DFEM) and almost no one for the least- squares finite element method. The additive angular dependent rebalance (AADR) acceleration arithmetic and its extrapolate method were given, in which the additive modification was used. It was applied to solve the transport equation with fixed source, fission source, in optically thick diffusive regions and with unstructured-mesh. The numerical results of benchmark problems demonstrate that the arithmetic can shorten the CPU time about 1.5-2 times and give high precise. (authors)
International Nuclear Information System (INIS)
We have investigated the angular dependence of the magnetic properties of cylindrical nanostructures comprised of a pair of nanotube and nanowire segments. We compared the magnetic behavior of these structures with the properties observed in an isolated nanowire and nanotube. Thus, we observed that the hysteresis curves of the cylindrical nanostructure with wire–tube morphology exhibits a step or plateau corresponding to a partial pinning of the domain wall at the interface between wire and tube sections. However, this step gradually disappears as we change the angle at which the external magnetic field is applied, thus enabling control of nucleation and release of a domain wall. Moreover, for small angles the nucleation and propagation of domain walls is observed, while for large angles is observed a quasi-coherent rotation. Finally, the possibility to alter the magnetization reversal mode in such nanostructures provides an attractive way to control the motion of magnetic domain walls. (papers)
Secondary-electron-emission spectroscopy of tungsten: Angular dependence and phenomenology
DEFF Research Database (Denmark)
Willis, Roy F.; Christensen, Niels Egede
1978-01-01
Angle-resolved energy-distribution measurements of secondary-electron emission (SEE) from metals reveal spectral fine structure that relates directly to the density distribution of the one-electron states throughout E-K→ space located above the vacuum level Ev. The angular dependence of the SEE...... have been carried out in both "reduced" and "extended" K→ space in order to assess the relative contribution of elastic umklapp scattering to the density distribution of contributing states profiles. The results indicate that the overall secondary-electron yield may be represented as the sum of....... Bulk and surface band-structure effects are concurrently manifest in the SEE spectra via the wave-matching conditions imposed at the solid-vacuum interface. The results are discussed within the general conceptual framework provided by "the (time-reversed) incoming final-state wave-function" approach to...
On the angular dependence and scattering model of polar mesospheric summer echoes at VHF
Sommer, Svenja; Stober, Gunter; Chau, Jorge L.
2016-01-01
We present measurements of the angular dependence of polar mesospheric summer echoes (PMSE) with the Middle Atmosphere Alomar Radar System in Northern Norway (69.30° N, 16.04° E). Our results are based on multireceiver and multibeam observations using beam pointing directions with off-zenith angles up to 25° as well as on spatial correlation analysis (SCA) from vertical beam observations. We consider a beam filling effect at the upper and lower boundaries of PMSE in tilted beams, which determines the effective mean angle of arrival. Comparing the average power of the vertical beam to the oblique beams suggests that PMSE are mainly not as aspect sensitive as in contrast to previous studies. However, from SCA, times of enhanced correlation are found, indicating aspect sensitivity or a localized scattering mechanism. Our results suggest that PMSE consist of nonhomogeneous isotropic scattering and previously reported aspect sensitivity values might have been influenced by the inhomogeneous nature of PMSE.
Angular and dose dependence of CR-39 neutron response for shape-selected tracks
Tam, N C; Lakosi, L
1999-01-01
A shape selection method corresponding to an energy discrimination was used to eliminate unwanted events disturbing evaluation of CR-39 detectors in detecting tracks induced by particles both of perpendicular and oblique incidence. The angular dependence of the response was examined, detecting fast neutrons from sup 2 sup 5 sup 2 Cf with shape selection technique at various angles and distances. Also, the CR-39 track detectors with the sup 2 sup 5 sup 2 Cf source were exposed to high gamma-intensity of a sup 6 sup 0 Co irradiation facility in the range 0.1 to 4.5 kGy, similar to the exposures inside spent fuel assemblies. Using the two functions the lower limit of burnup could be determined by the method.
International Nuclear Information System (INIS)
The x-ray drive on a capsule in an inertial confinement fusion setup is crucial for ignition. Unfortunately, a direct measurement has not been possible so far. We propose an angular radiation temperature simulation to predict the time-dependent drive on the capsule. A simple model, based on the view-factor method for the simulation of the radiation temperature, is presented and compared with the experimental data obtained using the OMEGA laser facility and the simulation results acquired with VISRAD code. We found a good agreement between the time-dependent measurements and the simulation results obtained using this model. The validated model was then used to analyze the experimental results from the Shenguang-III prototype laser facility. More specifically, the variations of the peak radiation temperatures at different view angles with the albedo of the hohlraum, the motion of the laser spots, the closure of the laser entrance holes, and the deviation of the laser power were investigated. Furthermore, the time-dependent radiation temperature at different orientations and the drive history on the capsule were calculated. The results indicate that the radiation temperature from “U20W112” (named according to the diagnostic hole ID on the target chamber) can be used to approximately predict the drive temperature on the capsule. In addition, the influence of the capsule on the peak radiation temperature is also presented
Energy Technology Data Exchange (ETDEWEB)
Jing, Longfei; Yang, Dong; Li, Hang; Zhang, Lu; Lin, Zhiwei; Li, Liling; Kuang, Longyu [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Jiang, Shaoen, E-mail: jiangshn@vip.sina.com; Ding, Yongkun [Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China); Huang, Yunbao, E-mail: huangyblhy@gmail.com [Mechatronics School of Guangdong University of Technology, Guangzhou 510080 (China)
2015-02-15
The x-ray drive on a capsule in an inertial confinement fusion setup is crucial for ignition. Unfortunately, a direct measurement has not been possible so far. We propose an angular radiation temperature simulation to predict the time-dependent drive on the capsule. A simple model, based on the view-factor method for the simulation of the radiation temperature, is presented and compared with the experimental data obtained using the OMEGA laser facility and the simulation results acquired with VISRAD code. We found a good agreement between the time-dependent measurements and the simulation results obtained using this model. The validated model was then used to analyze the experimental results from the Shenguang-III prototype laser facility. More specifically, the variations of the peak radiation temperatures at different view angles with the albedo of the hohlraum, the motion of the laser spots, the closure of the laser entrance holes, and the deviation of the laser power were investigated. Furthermore, the time-dependent radiation temperature at different orientations and the drive history on the capsule were calculated. The results indicate that the radiation temperature from “U20W112” (named according to the diagnostic hole ID on the target chamber) can be used to approximately predict the drive temperature on the capsule. In addition, the influence of the capsule on the peak radiation temperature is also presented.
Soliton-dependent plasmon reflection at bilayer graphene domain walls
Jiang, Lili; Shi, Zhiwen; Zeng, Bo; Wang, Sheng; Kang, Ji-Hun; Joshi, Trinity; Jin, Chenhao; Ju, Long; Kim, Jonghwan; Lyu, Tairu; Shen, Yuen-Ron; Crommie, Michael; Gao, Hong-Jun; Wang, Feng
2016-08-01
Layer-stacking domain walls in bilayer graphene are emerging as a fascinating one-dimensional system that features stacking solitons structurally and quantum valley Hall boundary states electronically. The interactions between electrons in the 2D graphene domains and the one-dimensional domain-wall solitons can lead to further new quantum phenomena. Domain-wall solitons of varied local structures exist along different crystallographic orientations, which can exhibit distinct electrical, mechanical and optical properties. Here we report soliton-dependent 2D graphene plasmon reflection at different 1D domain-wall solitons in bilayer graphene using near-field infrared nanoscopy. We observe various domain-wall structures in mechanically exfoliated graphene bilayers, including network-forming triangular lattices, individual straight or bent lines, and even closed circles. The near-field infrared contrast of domain-wall solitons arises from plasmon reflection at domain walls, and exhibits markedly different behaviours at the tensile- and shear-type domain-wall solitons. In addition, the plasmon reflection at domain walls exhibits a peculiar dependence on electrostatic gating. Our study demonstrates the unusual and tunable coupling between 2D graphene plasmons and domain-wall solitons.
Flux decomposition method: application to energy dependent particle reflection
International Nuclear Information System (INIS)
In this paper an analytical approximate method for solving Boltzmann transport equation is developed and its efficiency for treating energy dependent particle reflection is investigated. Procedure is based on particle flux decomposition in two parts. The first one is derived exactly and the second one is determined approximately by ordinary DPN method. Transport equation for a semi - infinite planar medium is rederived by assuming that slowing down of particles is described by energy independent total cross section and by four different models of synthetic scattering kernel. Energy reflection coefficients are computed for mono directional and isotropic incident flux and the accuracy of the flux decomposition method is assessed by comparison with exact solution, variational method and ordinary DPN approximations. (author). 21 refs., 3 figs., 4 tabs
International Nuclear Information System (INIS)
The results of the experiment on measuring the energy dependence of fission fragment angular anisotropy in resonance neutron induced fission of 235U aligned target in energy region up to 42 eV are presented. The agreement with the data of Pattenden and Postma in resonances is good enough, while the theoretical curve, calculated using the R-matrix multilevel two fission channel approach, does not seem to describe the energy dependence of fission fragment angular anisotropy property. The necessity of taking into account the interference between levels with different spins is discussed. 11 refs., 2 figs
International Nuclear Information System (INIS)
Based on simple random sampling (SRS), we propose a Monte Carlo method for the faster computation of the smoothed part of the density of nuclear states. To test the applicability of the SRS approach we study in this framework the excitation energy (E), angular momentum (J) and parity dependence of nuclear level densities for an independent particle system. As an illustrative example, we consider a pf-shell nucleus, 48Cr. It is found that the values of a few lower order moments for the state density I(E) calculated using SRS and combinatorial (or direct counting) methods are almost the same and a locally smoothed part of the state density can be constructed using these moments in a univariate Edgeworth expansion. We calculate the energy dependent spin-cutoff factor and parity asymmetry and find that for both cases the SRS approach works quite well. We use the SRS moments to construct different forms of the bivariate distribution for I(E,M) (M is the z-component of J) namely (a) a bivariate Edgeworth expansion, (b) a product of the univariate Edgeworth expansion (I(E)) and a Gaussian form for conditional M distribution I(M vertical stroke E) and (c) a product of the univariate Edgeworth expansions for both I(E) and I(M vertical stroke E) and compare the resulting fixed-J level density Il(E,J) with the corresponding combinatorial results. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Jursinic, Paul A., E-mail: pjursinic@wmcc.org [West Michigan Cancer Center, 200 North Park Street, Kalamazoo, Michigan 49007 (United States)
2015-10-15
Purpose: A type of in vivo dosimeter, an optically stimulated luminescent dosimeter, OSLD, may have dose sensitivity that depends on the angle of incidence of radiation. This work measures how angular dependence of a nanoDot changes with the geometry of the phantom in which irradiation occurs and with the intrinsic structure of the nanoDot. Methods: The OSLDs used in this work were nanoDot dosimeters (Landauer, Inc., Glenwood, IL), which were read with a MicroStar reader (Landauer, Inc., Glenwood, IL). Dose to the OSLDs was delivered by 6 MV x-rays. NanoDots with various intrinsic sensitivities were irradiated in numerous phantoms that had geometric shapes of cylinders, rectangles, and a cube. Results: No angular dependence was seen in cylindrical phantoms, cubic phantoms, or rectangular phantoms with a thickness to width ratio of 0.3 or 1.5. An angular dependence of 1% was observed in rectangular phantoms with a thickness to width of 0.433–0.633. A group of nanoDots had sensitive layers with mass density of 2.42–2.58 g/cm{sup 3} and relative sensitivity of 0.92–1.09 and no difference in their angular dependence. Within experimental uncertainty, nanoDot measurements agree with a parallel-plate ion chamber at a depth of maximum dose. Conclusions: When irradiated in cylindrical, rectangular, and cubic phantoms, nanoDots show a maximum angular dependence of 1% or less at an incidence angle of 90°. For a sample of 78 new nanoDots, the range of their relative intrinsic sensitivity is 0.92–1.09. For a sample of ten nanoDots, on average, the mass in the sensitive layer is 73.1% Al{sub 2}O{sub 3}:C and 26.9% polyester. The mass density of the sensitive layer of a nanoDot disc is between 2.42 and 2.58 g/cm{sup 3}. The angular dependence is not related to Al{sub 2}O{sub 3}:C loading of the nanoDot disc. The nanoDot at the depth of maximum dose has no more angular dependence than a parallel-plate ion chamber.
International Nuclear Information System (INIS)
Purpose: A type of in vivo dosimeter, an optically stimulated luminescent dosimeter, OSLD, may have dose sensitivity that depends on the angle of incidence of radiation. This work measures how angular dependence of a nanoDot changes with the geometry of the phantom in which irradiation occurs and with the intrinsic structure of the nanoDot. Methods: The OSLDs used in this work were nanoDot dosimeters (Landauer, Inc., Glenwood, IL), which were read with a MicroStar reader (Landauer, Inc., Glenwood, IL). Dose to the OSLDs was delivered by 6 MV x-rays. NanoDots with various intrinsic sensitivities were irradiated in numerous phantoms that had geometric shapes of cylinders, rectangles, and a cube. Results: No angular dependence was seen in cylindrical phantoms, cubic phantoms, or rectangular phantoms with a thickness to width ratio of 0.3 or 1.5. An angular dependence of 1% was observed in rectangular phantoms with a thickness to width of 0.433–0.633. A group of nanoDots had sensitive layers with mass density of 2.42–2.58 g/cm3 and relative sensitivity of 0.92–1.09 and no difference in their angular dependence. Within experimental uncertainty, nanoDot measurements agree with a parallel-plate ion chamber at a depth of maximum dose. Conclusions: When irradiated in cylindrical, rectangular, and cubic phantoms, nanoDots show a maximum angular dependence of 1% or less at an incidence angle of 90°. For a sample of 78 new nanoDots, the range of their relative intrinsic sensitivity is 0.92–1.09. For a sample of ten nanoDots, on average, the mass in the sensitive layer is 73.1% Al2O3:C and 26.9% polyester. The mass density of the sensitive layer of a nanoDot disc is between 2.42 and 2.58 g/cm3. The angular dependence is not related to Al2O3:C loading of the nanoDot disc. The nanoDot at the depth of maximum dose has no more angular dependence than a parallel-plate ion chamber
Impact of surface-polish on the angular and wavelength dependence of fiber focal ratio degradation
Eigenbrot, Arthur D; Wood, Corey M
2012-01-01
We present measurements of how multimode fiber focal-ratio degradation (FRD) and throughput vary with levels of fiber surface polish from 60 to 0.5 micron grit. Measurements used full-beam and laser injection methods at wavelengths between 0.4 and 0.8 microns on 17 meter lengths of Polymicro FBP 300 and 400 micron core fiber. Full-beam injection probed input focal-ratios between f/3 and f/13.5, while laser injection allowed us to isolate FRD at discrete injection angles up to 17 degrees (f/1.6 marginal ray). We find (1) FRD effects decrease as grit size decreases, with the largest gains in beam quality occurring at grit sizes above 5 microns; (2) total throughput increases as grit size decreases, reaching 90% at 790 nm with the finest polishing levels; (3) total throughput is higher at redder wavelengths for coarser polishing grit, indicating surface-scattering as the primary source of loss. We also quantify the angular dependence of FRD as a function of polishing level. Our results indicate that a commonly a...
Angular Dependence of the Facular-Sunspot Coverage Relation as Derived by MDI Magnetograms
Criscuoli, S.
2016-07-01
Previous studies have shown that the variation over the solar magnetic activity cycle of the area of facular/network features identified from broad-band and narrow-band imagery is positively correlated with the sunspot area and number, the relation being described as either linear or quadratic. On the other hand, the temporal variation of the spatial distributions of faculae, network and sunspots follows patterns that are less obviously correlated, so that we expect the relation that describes variation of the area coverage of different types of magnetic features to vary with the position over the disk. In this work we employ Michelson Doppler Interferometer (MDI) full-disk magnetograms acquired during solar cycle 23 and at the beginning of cycle 24 to investigate the relation between the coverage of magnetic elements characterized by different amounts of magnetic flux and located at different angular distances from disk center with the sunspot number. In agreement with some previous studies we find that daily data are best described by a quadratic function while data averaged over six months are best described by a linear function. In both cases the coefficients of the fits show large dependence on the position over the disk and the magnetic flux. We also find that toward disk center six-month averaged data show asymmetries between the ascending and the descending phases. The implications for solar irradiance modeling are discussed.
Improved angular momentum evolution model for solar-like stars II. Exploring the mass dependence
Gallet, Florian
2015-01-01
We developed angular momentum evolution models for 0.5 and 0.8 $M_{\\odot}$ stars. The parametric models include a new wind braking law based on recent numerical simulations of magnetised stellar winds, specific dynamo and mass-loss rate prescriptions, as well as core/envelope decoupling. We compare model predictions to the distributions of rotational periods measured for low mass stars belonging to star forming regions and young open clusters. Furthermore, we explore the mass dependence of model parameters by comparing these new models to the solar-mass models we developed earlier. Rotational evolution models are computed for slow, median, and fast rotators at each stellar mass. The models reproduce reasonably well the rotational behaviour of low-mass stars between 1~Myr and 8-10~Gyr, including pre-main sequence to zero-age main sequence spin up, prompt zero-age main sequence spin down, and early-main sequence convergence of the surface rotation rates. Fast rotators are found to have systematically shorter di...
Angular Momentum Dependent Quark Potential of QCD Traits and Dynamical O(4) Symmetry
Compean, C B
2006-01-01
A common quark potential that captures the essential traits of the QCD quark-gluon dynamics is expected to (i) interpolate between a Coulomb-like potential (associated with one-gluon exchange) and the infinite wall potential (associated with trapped but asymptotically free quarks), (ii) reproduce in the intermediary region the linear confinement potential (associated with multi-gluon self-interactions) as established by lattice QCD calculations of hadron properties. We first show that the exactly soluble trigonometric Rosen-Morse potential possesses all these properties. Next we observe that this potential, once interpreted as angular momentum dependent, acquires a dynamical O(4) symmetry and reproduces exactly quantum numbers and level splittings of the non-strange baryon spectra in the SU(2)_I* O(4) classification scheme according to which baryons cling on to multi-spin parity clusters of the type (K/2,K/2)*[(1/2,0) + (0, 1/2)], whose relativistic image is \\psi_{\\mu_{1}...\\mu_{K}}. Finally, we bring exact e...
Juang, Fuh-Shyang; Laih, Li-Hong; Lin, Chia-Ju; Hsu, Yu-Jen
2002-04-01
An optical microcavity structure was used in organic light emitting diodes. We succeeded in fabricating a device with sharply directed emission vertical to an emission surface. The device shows green emission (bright green) at normal position which turns red (bright red) at the 30° position. The angular dependences of the electroluminescence and the emission patterns versus viewing angle in the microcavity OLED were studied. The resonance wavelength λ decreases with viewing angle. The emission peak at 490 nm is directed vertically to the device surface more sharply than that at 632 nm. The microcavity structure shows non-Lambertian emission. The spectra appear more blue off-axis and the intensity of the green-like emission decreases rapidly with increasing viewing angle. A significantly narrow linewidth of 7.4 nm in the 0° direction for the 490 nm peak was observed. The full-widths at half maximum (FWHM) of the green-like spectra are much smaller than those of the red-like ones, indicating better cavity quality.
Tomographic imaging of the angular-dependent coherent-scatter cross section.
Westmore, M S; Fenster, A; Cunningham, I A
1997-01-01
A new special-purpose computed tomographic (CT) imaging system is described which produces images based on measurements of the low-angle (0-10 degrees) x-ray diffraction properties of an object. Low-angle scatter in the diagnostic x-ray energy range is dominated by coherent scatter, and the system uses first-generation CT geometry to acquire a diffraction pattern for each pencil beam. The patterns are used to reconstruct a series of images which represent the coherent-scatter intensity at a series of scatter angles. To demonstrate the potential of coherent-scatter CT (CSCT), the scanner has been built and used to image a phantom consisting of a water-filled Lucite cylinder containing rods of polyethylene, Lucite, polycarbonate, and nylon. In this paper, the system is described and a sequence of CSCT images of this phantom is shown. Coherent-scatter cross sections of these materials are generated for each pixel from this sequence of images and compared with cross sections measured separately. The resulting excellent agreement shows that the angular-dependent coherent-scatter cross section can be accurately imaged in a tomographic slice through an object. These cross sections give material-specific information about the object. The long-term goal of this research is to make measurements of bone-mineral content for every pixel in a tomographic slice. PMID:9029536
Institute of Scientific and Technical Information of China (English)
H. M. Al-Khateeb; M. K. Alqadi; F. Y. Alzoubi; N. Y. Ayoub
2007-01-01
The dipole-dipole interaction model is used to calculate the angular dependence of lateral and levitation forces on a small permanent magnet and a cylindrical superconductor in the Meissner state lying laterally offthe symmetric axis of the cylinder. Under the assumption that the lateral displacement of the magnet is small compared with the physical dimensions of the system, we obtain analytical expressions for the lateral and levitation forces as functions of geometrical parameters of the superconductor as well as the height, the lateral displacement and the orientation of magnetic moment of the magnet. The effect of thickness and radius of the superconductor on the levitation force is similar to that for a symmetric magnet/superconducting cylinder system, but within the range of lateral displacement. The splitting in the levitation force increases with the increasing angle of orientation of the magnetic moment of the magnet. For a given lateral displacement of the magnet, the lateral force vanishes when the magnetic moment is perpendicular to the surface of the superconductor and has a maximum value when the moment is parallel to the surface. For a given orientation of the magnetic moment, the lateral force has a linear relationship with the lateral displacement. The stability of the magnet above the superconducting cylinder is discussed in detail.
Spectral dependence of angular distribution halfwidths of Vavilov-Cherenkov radiation
International Nuclear Information System (INIS)
Angular distributions of Vavilov-Cherenkov radiation have been measured. This radiaiton is excited during 210 keV electron propagation in a mica 2.5 mm thick target in a spectral range from 2500 up to 5000 A. A formula for diffraction halfwidth of angular distribution has been derived, its applicability limits are pointed out. Experimental halfwidth agrees with the calculated ones. The deviation of angular distribution maximum from Vavilov-Cherenkov radiation angle is analyzed. This deviation is due to radiator boundaries and multiple scattering of electrons
Energy Technology Data Exchange (ETDEWEB)
Brady, J.W. Jr.; Doll, J.D.; Thompson, D.L.
1978-10-15
The angular and velocity distributions for gas/solid-surface collisions are examined. It is shown that the envelope of the scattered phase-space distribution is quite sensitive to the gas/surface interaction potential.
Qin, S; Chen, T; Wang, L; Tu, Y; Yue, N; Zhou, J
2014-08-01
The focus of this study is the angular dependence of two types of Metal Oxide Semiconductor Field Effect Transistor (MOSFET) dosimeters (MOSFET20 and OneDose/OneDosePlus) when used for surface dose measurements. External beam radiationat different gantry angles were delivered to a cubic solid water phantom with a MOSFET placed on the top surface at CAX. The long axis of the MOSFET was oriented along the gantry axis of rotation, with the dosimeter (bubble side) facing the radiation source. MOSFET-measured surface doses were compared against calibrated radiochromic film readings. It was found that both types of MOSFET dosimeters exhibited larger than previously reported angular dependence when measuring surface dose in beams at large oblique angles. For the MOSFET20 dosimeter the measured surface dose deviation against film readings was as high as 17% when the incident angle was 72 degrees to the norm of the phantom surface. It is concluded that some MOSFET dosimeters may have a strong angular dependence when placed on the surface of water-equivalent material, even though they may have an isotropic angular response when surrounded by uniform medium. Extra on-surface calibration maybe necessary before using MOSFET dosimeters for skin dose measurement in tangential fields. PMID:24206205
Directory of Open Access Journals (Sweden)
Sonia Garcia Pereira Cecatti
2006-12-01
Full Text Available As dependências energética e angular de diferentes materiais termoluminescentes foram estudadas com o objetivo de verificar que tipo de detector seria o mais adequado para a monitoração de trabalhadores envolvidos com a radiação beta. Três tipos de pastilhas de CaSO4:Dy + teflon foram estudados. A dependência energética foi verificada usando-se fontes padrões de radiação beta (147Pm, 204Tl e 90Sr+90Y. A dependência angular foi verificada irradiando-se as amostras com feixes de radiação beta, variando-se o ângulo de incidência entre 0° e 90°. Os dosímetros de CaSO4:Dy + teflon + 10% C mostram-se os mais adequados para uso na monitoração de trabalhadores expostos à radiação beta, em relação às características estudadas.Energy and angular dependences of different thermoluminescent materials were studied with the objective to verify which type of detector would be the most appropriate for beta monitoring of workers. Three types of CaSO4:Dy + teflon pellets were studied. The energy dependence was evaluated using standard beta radiation sources (147Pm, 204Tl and 90Sr+90Y. For the angular dependence study, the pellets were exposed to beta radiation of the 90Sr+90Y source, varying the incidence angle between 0° and 90°. In relation to the studied characteristics, the CaSO4:Dy + 10% C dosimeters were the most adequate for use in beta monitoring of workers.
International Nuclear Information System (INIS)
The present thesis describes the measurement of α and proton anisotropies in the Darmstadt-Heidelberg crystal ball relative to the spin direction and in dependence on the prompt detector multiplicity for 155,159,161Ho compound nuclei from the fusion reactions 37Cl+124Sn at 200 and 251 MeV incident energy, 37Cl+118Sn at 251 MeV, as well as 173 MeV 18O+141Pr. A novel and reliable procedure for the determination of the anisotropy is given which regards the broadening of the spin distribution by measurement of the E2-inertia ellipsoid at limited photon number as well as the statistical particle cascade on a purely experimental base. Only for the correction for ''defects'' of the crystal ball simulation calculations are necessary. The main results are: (1) Detection of a superdeformation (vertical strokeδvertical stroke≥0.6) of α emitting nuclei in the range of the neutron number 85≤N≤89. vertical strokeδvertical stroke grows with increasing angular momentum of the emitting nuclei and reaches the value vertical strokeδvertical stroke≅0.6 in the 251 MeV 37Cl+124Sn→161Ho reaction at I≅80ℎ, in the 37Cl+118Sn→155Ho reaction at I≅55ℎ. (2) The α emitting residual nuclei formed in the 251 MeV 37Cl+118Sn reaction (anti N 85) show significantly larger deformations than those formed in 251 MeV 37Cl+124Sn (anti N 88). The extremely large deformation of the formed nuclei seems to confirm the shape isomerism of 156Er (N=88) predicted by Aberg and the superdeformation at 152Dy reported by Nyako et al. as nuclear property of the transition region. (orig.)
Zou, L. K.; Zhang, Y.; Gu, L.; Cai, J. W.; Sun, L.
2016-02-01
Angular-dependent magnetoresistance (MR) is considered to be intrinsic to spintronic materials, represented by the classical anisotropic MR (AMR) phenomenon and the recently emerged spin Hall MR (SMR). So far, isotropic AMR, AMR with geometric size effect and interfacial effect, and SMR have been treated separately to explain distinct MR correlations observed in various systems. Current study shows all four types of MR correlations can be reproduced in Fe thin films depending on the film thickness, texture, interface, and morphology. Results suggest previous explanations of the thin-film MR correlations are incomplete and it is inappropriate to use a specific MR angular-dependent correlation as the sole criterion in determining the origin of AMR or ascertaining the exclusive existence of SMR.
Angular dependence of the luminance and contrast in medical monochrome liquid crystal displays
International Nuclear Information System (INIS)
Active-matrix liquid crystal displays (AMLCDs) are light-modulating devices that generate images by differentially transmitting a nearly uniform luminous field provided by a backlight. While emissive displays exhibit a quasi-Lambertian emission with almost constant contrast at off-normal viewing, the anisotropy of the electro-optic effect that controls light transmission in AMLCDs causes a pixel luminance that varies, sometimes strongly, with viewing angle. These variations are not identical for all gray levels and can eventually cause grayscale inversions. In this paper, we measured the luminance emission of a monochrome medical AMLCD, a medical cathode-ray tube monitor, and a color desktop AMLCD, using a collimated photopic probe positioned on a manual rotation arm, and a research radiometer with automatic readout. The probe measures luminance with a small acceptance angle and provides optical shielding from emissions at other viewing directions that contaminate the readings. We obtained luminance response curves versus angle in the vertical, horizontal and at 45 deg. diagonal directions. The display systems were calibrated to reflect the DICOM Part 3.14 standard grayscale display function (GDF) when measured using the manufacturer's probe and software tools. We analyzed the measurements at different viewing directions with respect to their departure from the GDF by computing the normalized contrast (ΔL/L) as a function of the DICOM just-noticeable difference index. Although cathode-ray tubes are known to be quasi-Lambertian emitters, the luminance at normal viewing is higher than the luminance observed at large angles. This decrease in luminance is however proportionally similar for all gray levels, resulting in a relatively flat contrast response for all angles. In addition to being more pronounced, the angular variation in AMLCDs does not follow the same profile at different intensities with the subsequent variation in the achieved display contrast. The
Directory of Open Access Journals (Sweden)
Andreas Burkart
2015-01-01
Full Text Available In this study we present a hyperspectral flying goniometer system, based on a rotary-wing unmanned aerial vehicle (UAV equipped with a spectrometer mounted on an active gimbal. We show that this approach may be used to collect multiangular hyperspectral data over vegetated environments. The pointing and positioning accuracy are assessed using structure from motion and vary from σ = 1° to 8° in pointing and σ = 0.7 to 0.8 m in positioning. We use a wheat dataset to investigate the influence of angular effects on the NDVI, TCARI and REIP vegetation indices. Angular effects caused significant variations on the indices: NDVI = 0.83–0.95; TCARI = 0.04–0.116; REIP = 729–735 nm. Our analysis highlights the necessity to consider angular effects in optical sensors when observing vegetation. We compare the measurements of the UAV goniometer to the angular modules of the SCOPE radiative transfer model. Model and measurements are in high accordance (r2 = 0.88 in the infrared region at angles close to nadir; in contrast the comparison show discrepancies at low tilt angles (r2 = 0.25. This study demonstrates that the UAV goniometer is a promising approach for the fast and flexible assessment of angular effects.
Surrogate Reaction Measurement of Angular Dependent 239Pu (n , f) Probabilities
Koglin, Johnathon; Burke, Jason; Casperson, Robert; Jovanovic, Igor
2015-10-01
The surrogate method has previously been used to measure (n , f) cross sections of difficult to produce actinide isotopes. These measurements have inaccuracies at excitation energies below 1.5 MeV where the distribution of angular momentum states populated in the compound nucleus created by neutron absorption significantly differs from that arising from direct reactions. A method to measure the fission probability of individual angular momentum states arising from 239Pu (d , pf) and 239Pu (α ,α' f) reactions has been developed. This experimental apparatus consists of charged particle detectors with 40 keV FWHM resolution at 13 angles up and downstream of the particle beam. A segmented array of photovoltaic (solar) cells is used to measure the angular distribution of fission fragments. This distribution uniquely identifies the populated angular momentum states. These are fit to expected distributions to determine the contribution of each state. The charged particle and fission rates matrix obtained from this analysis determines fission probabilities of specific angular momentum states in the transition nucleus. Development of this scheme and first results will be discussed.
Hu, T.; Xiao, H; Sayles, T. A.; M.B. Maple; Maki, Kazumi; Dora, B.; Almasan, C. C.
2006-01-01
In-plane angular dependent resistivity ADR was measured in the non-Fermi liquid regime of CeCoIn$_5$ single crystals at temperatures $T \\le 20$ K and in magnetic fields $H$ up to 14 T. Two scaling behaviors were identified in low field region where resistivity shows T-linear dependence, separated by a critical angle $\\theta_{c}$ which is determined by the anisotropy of CeCoIn$_5$; i.e., ADR depends only on the perpendicular (parallel) field component below (above) $\\theta_c$. These scaling be...
Lu, Wanglin; Ma, Xiaomeng; Fei, Zhen; Zhou, Jianguang; Zhang, Zhiyong; Jin, Chuanhong; Zhang, Ze
2015-07-01
In this study, we correlated the angular dependence of the Raman response of black phosphorus to its crystallographic orientation by using transmission electron microscopy and Raman spectroscopy. It was found that the intensity of the Ag 2 mode reached a maximum when the polarization direction of the incident light was parallel to the zigzag crystallographic orientation. Notably, it was further confirmed that the zigzag crystallographic direction exhibited superior conductance and carrier mobility. Because of the lattice extension along the armchair direction, an intensification of the anisotropic Raman response was observed. This work provides direct evidence of the correlation between anisotropic properties and crystallographic direction and represents a turning point in the discussion of the angular-dependent electronic properties of black phosphorus.
Energy Technology Data Exchange (ETDEWEB)
Perini, Ana P.; Neves, Lucio P.; Xavier, Marcos; Caldas, Linda V.E., E-mail: mxavier@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Khoury, Helen J., E-mail: khoury@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear
2011-07-01
In this paper a pencil-type ionization chamber designed and manufactured at Instituto de Pesquisas Energeticas e Nucleares was evaluated for dosimetric applications in computed tomography beams. To evaluate the performance of this chamber two tests were undertaken: linearity of response and angular dependence. The results obtained in these tests showed good results, within the international recommendations. Moreover, this homemade ionization chamber is easy to manufacture, of low cost and efficient. (author)
Dasgupta, Basudeb; Sen, Manibrata
2016-01-01
It has been recently pointed out that neutrino fluxes from a supernova can show substantial flavor conversions almost immediately above the core. Using linear stability analyses and numerical solutions of the fully nonlinear equations of motion, we perform a detailed study of these fast conversions, focussing on the region just above the supernova core. We carefully specify the instabilities for evolution in space or time, and find that neutrinos travelling towards the core make fast conversions more generic, i.e., possible for a wider range of flux ratios and angular asymmetries. Using fluxes and angular distributions predicted by supernova simulations, we find that fast conversions can occur within tens of nanoseconds, only a few meters away from the putative neutrinospheres. If these fast flavor conversions indeed take place, they would have important implications for the supernova explosion mechanism and nucleosynthesis.
Energy Technology Data Exchange (ETDEWEB)
Seregin, A.A.
1976-03-01
In framework of a phenomenological collective nuclear theory the dependence of the moment of inertia on the angular velocity squared is studied. It is shown that this theory may explain the S shape of dependence of J on ..omega../sup 2/ if the collective motion potential V(..beta..) has two points of inflection. Anomalies in the low-lying part of the energy spectrum of the nuclei /sup 184/Hg and /sup 186/Hg are related to inflection points of the potential.
Vasques, Richard
2013-01-01
This paper extends a recently introduced theory describing particle transport for random statistically homogeneous systems in which the distribution function p(s) for chord lengths between scattering centers is non-exponential. Here, we relax the previous assumption that p(s) does not depend on the direction of flight \\Omega; this leads to an extended generalized linear Boltzmann equation that includes angular-dependent cross sections, and to an extended generalized diffusion equation that accounts for anisotropic behavior resulting from the statistics of the system.
Energy Technology Data Exchange (ETDEWEB)
Geerkens, A.; Frenck, H.J.; Ewert, S. [Technical Univ. of Cottbus (Germany)] [and others
1994-12-31
The angular dependence of the critical current density and the magnetoresistance of high-T{sub c}-films in high and low magnetic fields and for different temperatures were measured to investigate the flux pinning and the superconducting properties. A comparison of the results for the different superconductors shows their increasing dependence on the angle {Theta} between the magnetic field and the c-axis of the film due to the anisotropy of the chosen superconductor. Furthermore the influence of the current direction to the {Theta}-rotation plane is discussed.
International Nuclear Information System (INIS)
An additive angular-dependent re-balance (AADR) factor acceleration method is described to accelerate the source iteration of discrete ordinates transport calculation. The formulation of the AADR method follows that of the angular-dependent re-balance (ADR) method in that the re-balance factor is defined only on the cell interface and in that the low-order equation is derived by integrating the transport equation (high-order equation) over angular subspaces. But, the re-balance factor is applied additively. While the AADR method is similar to the boundary projection acceleration and the alpha-weighted linear acceleration, it is more general and does have distinct features. The method is easily extendible to DPN and low-order SN re-balancing, and it does not require consistent discretizations between the high- and low-order equations as in diffusion synthetic acceleration. We find by Fourier analysis and numerical results that the AADR method with a chosen form of weighting functions is unconditionally stable and very effective. There also exists an optimal weighting parameter that leads to the smallest spectral radius. The AADR acceleration method described in this paper is simple to implement, unconditionally stable, and very effective. It uses a physically based weighting function with an optimal parameter, leading to the best spectral radius of ρ<0.1865, compared to ρ<0.2247 of DSA. The application of the AADR acceleration method with the LMB scheme on a test problem shows encouraging results
Reactor analysis methods. 6. Angular Dependence of the Fast Flux in Reactor Lattices
International Nuclear Information System (INIS)
We study the high-energy ('fast') angular flux in an infinite lattice of fuel and moderator, finding that the flux is a bumpy, irregular function of azimuthal direction. We approximate the problem as an infinite lattice of identical pins (with cladding and gap homogenized into the fuel) in a sea of moderator. A unit cell in this lattice has a quarter-circle fuel pin inside a square of moderator, with the center of the circle at one corner of the square. To facilitate easy calculation with different transport codes, we have approximated this geometry by using square fuel pins, as shown in Fig. 1. In our idealized two-dimensional (2-D) problem, the pins and moderator are infinite in the axial direction. The materials have the following properties: 1. The fast-neutron source is in the fuel only. 2. There is within-group scattering in the fuel but almost none in the moderator. (Most scatters in the moderator will remove the neutron from the fast group.) 3. The fuel pin is n) to represent accurately, and difficult for Monte Carlo methods to sample adequately. We remark that the variation in the polar variable μ is relatively smooth (as is true in most 2-D problems). We further remark that homogenized pin cells do not produce complicated angular variations -this is a challenge encountered when we attack the transport problem with heterogeneous pin cells. (When Smith began using a long characteristic code to solve heterogeneous instead of homogenized pin cells he initially obtained large errors; subsequent discussion led us to perform the study reported here). Finally, we remark that the square fuel pins do not cause the complex behavior; preliminary investigations (and geometrical reasoning) indicate that round pins generate similar complexities. Within the discrete ordinates framework, this problem calls for a 'product' quadrature (which uses separate quadratures for the γ and μ integrals) because there is far more complexity in γ than in m. We have experimented
International Nuclear Information System (INIS)
Calibrations of instrument efficiency of surface contamination meters are usually made with extended reference sources which are standardized in terms of 2π surface β-particle emission rates from the source surface including backscattered particles. Extended sources supplied from various metrology institutes or calibration laboratories, but the source-types such as structure, preparation method, backing and covering materials vary between manufacturers. In this work first we show how the calibration results are dependent on the source type. Second, in order to clarify the possible reason of such discrepancy, we examined the isotropy of β-particle fluences by the use of a proportional counter and also observed the angular dependence of β-particle spectra by the use of small plastic scintillation spectrometer, where the source mount can rotate relative to the detector window at various obliquities. The discrepancy in the instrument-calibration of surface contamination meters, which are mainly used under the conditions of large source-to-detector geometry, can be explained. - Highlights: ► We show how the calibration results are dependent on the source type. ► We examined the isotropy of β-particle fluences and observed the angular dependence. ► Discrepancy of instrument efficiencies using different type of sources is explained.
International Nuclear Information System (INIS)
Epitaxial thin films of HoNi2B2C and related superconducting rare earth borocarbide compounds act as a suitable basis for numerous investigations on structural and superconductive properties such as Tc, Hc2 and Jc. A new batch of HoNi2B2C thin films was grown on ceramic single crystal magnesium oxide substrates under ultra-high vacuum conditions using pulsed laser deposition. A detailed view on the deposition parameters and the physical film properties is presented and angular Hc2- and Jc-measurements are shown. (orig.)
Refractive index dependence of Papilio Ulysses butterfly wings reflectance spectra
Isnaeni, Muslimin, Ahmad Novi; Birowosuto, Muhammad Danang
2016-02-01
We have observed and utilized butterfly wings of Papilio Ulysses for refractive index sensor. We noticed this butterfly wings have photonic crystal structure, which causes blue color appearance on the wings. The photonic crystal structure, which consists of cuticle and air void, is approximated as one dimensional photonic crystal structure. This photonic crystal structure opens potential to several optical devices application, such as refractive index sensor. We have utilized small piece of Papilio Ulysses butterfly wings to characterize refractive index of several liquid base on reflectance spectrum of butterfly wings in the presence of sample liquid. For comparison, we simulated reflectance spectrum of one dimensional photonic crystal structure having material parameter based on real structure of butterfly wings. We found that reflectance spectrum peaks shifted as refractive index of sample changes. Although there is a slight difference in reflectance spectrum peaks between measured spectrum and calculated spectrum, the trend of reflectance spectrum peaks as function of sample's refractive index is the similar. We assume that during the measurement, the air void that filled by sample liquid is expanded due to liquid pressure. This change of void shape causes non-similarity between measured spectrum and calculated spectrum.
Spin and temperature dependence of nuclear deformation using alpha-gamma angular correlations
International Nuclear Information System (INIS)
Alpha-particle angular distributions with respect to the spin direction of residual nuclei have been measured in heavy-ion fusion reactions. The spin direction was determined by measuring the γ-ray angular distributions, for each event, using the spin spectrometer. α-particle anisotropies have been extracted for the compound nuclear systems: 110Sn*(94 MeV), 114Sn*(80 MeV), 138Nd*(82 MeV), 164Yb*(67 MeV) and 170Yb*(135 MeV) as a function of the α-particle energy and γ-ray multiplicity. The results are compared with statistical model calculations using transmission coefficients from a spherically symmetric optical model potential. The trend of the anisotropy coefficients below the evaporation Coulomb barrier is consistent with spherical emitting shapes in the case of the Sn* isotopes. Small deformation effects are suggested by the 138Nd* and 164Yb* data. The 170Yb* data indicate a large deformation which increases considerably with increasing spin. These results are in agreement with findings for similar systems in which the decay of the giant resonances built on excited states have been studied. 16 refs., 5 figs
International Nuclear Information System (INIS)
To investigate the influence of expansion of double kinks on flux pinning properties in films with high density of columnar defects (CDs), heavy ions were irradiated onto YBCO thin films along the c-axis. The n-value exhibited a peak around B ‖ c-axis in angular dependences as well as Jc for films even with Bϕ = 12 T, while the inverse correlation between Jc and n-value was observed around B ‖ ab. The introduction of a large amount of CDs into YBCO thin films also led to much larger dynamic critical exponent z. (author)
Adams, J; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Bezverkhny, B I; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, C O; Blyth, S L; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Bravar, A; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca-Sanchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, Y; Cheng, J; Cherney, M; Chikanian, A; Choi, H A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; Daugherity, M; De Moura, M M; Dedovich, T G; De Phillips, M; Derevshchikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Dutta-Majumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Yu; Fu, J; Gagliardi, C A; Gaillard, L; Gans, J; Ganti, M S; Ghazikhanian, V; Ghosh, P; González, J E; Gorbunov, Y G; Gos, H; Grebenyuk, O; Grosnick, D P; Guertin, S M; Guimaraes, K S F F; Guo, Y; Gupta, N; Gutíerrez, T D; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horner, M J; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Jacobs, P; Jacobs, W W; Jakl, P; Jia, F; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Krämer, M; Kravtsov, P; Kravtsov, V I; Krüger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; La Pointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C H; Lehocka, S; Le Vine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; López-Noriega, M; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Melnik, Yu M; Meschanin, A; Miller, M L; Minaev, N G; Mioduszewski, S; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnár, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Netrakanti, P K; Nikitin, V A; Nogach, L V; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pachr, M; Pal, S K; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevozchikov, V; Perkins, C; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Poljak, N; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M V; Potrebenikova, E V; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ray, R L; Razin, S V; Reinnarth, J; Relyea, D; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimansky, S S; ESichtermann; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sørensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Suaide, A A P; Sugarbaker, E R; Sumbera, M; Sun, Z; Surrow, B; Swanger, M; Symons, T J M; Szanto, A; de Toledo; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T J; Thein, D; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; Van der Kolk, N; Van Leeuwen, M; Van der Molen, A M; Varma, R; Vasilevski, I M; Vasilev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I K; Yurevich, V I; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X
2006-01-01
We present the first study of the energy dependence of $p_t$ angular correlations inferred from event-wise mean transverse momentum $$ fluctuations in heavy ion collisions. We compare our large-acceptance measurements at CM energies $\\sqrt{s_{NN}} =$ 19.6, 62.4, 130 and 200 GeV to SPS measurements at 12.3 and 17.3 GeV. $p_t$ angular correlation structure suggests that the principal source of $p_t$ correlations and fluctuations is minijets (minimum-bias parton fragments). We observe a dramatic increase in correlations and fluctuations from SPS to RHIC energies, increasing linearly with $\\ln \\sqrt{s_{NN}}$ from the onset of observable jet-related $$ fluctuations near 10 GeV.
Angular dependent torque measurements on CaFe0.88Co0.12AsF
Xiao, H.; Gao, B.; Ma, Y. H.; Li, X. J.; Mu, G.; Hu, T.
2016-08-01
Out-of-plane angular dependent torque measurements were performed on CaFe0.88Co0.12AsF (Ca1 1 1 1) single crystals. In the normal state, the torque data shows \\sin 2θ angular dependence and H 2 magnetic field dependence, as a result of paramagnetism. In the mixed state, the torque signal is a combination of the vortex torque and paramagnetic torque, and the former allows the determination of the anisotropy parameter γ. At T = 11.5 K, γ (11.5 K ≃ 0.5 T c) = 19.1, which is similar to the result of SmFeAsO0.8F0.2, γ ≃ 23 at T≃ 0.4{{T}\\text{c}} . So the 11 1 1 is more anisotropic compared to 11 and 122 families of iron-based superconductors. This may suggest that the electronic coupling between layers in 1 1 1 1 is less effective than in 11 and 122 families.
Study on Angular Dependence in Micro-cavity OLED%微腔OLED的视角特性研究
Institute of Scientific and Technical Information of China (English)
袁桃利; 张方辉; 牟强; 马颖; 张思璐
2012-01-01
The angular dependence of QLED is studied and it showed that the brightness and current efficiency gradually decreased with increased view angle, the intensity and current efficiency at 50 degrees dropped to 1/3 and 40% respectively with respect to the normal direction. And Color coordinates produce drift at a certain extent with increased view angle, but spectral peak and FWHM didn＇t change depend on the angle. Reasons for the occurrence of angular dependence were discussed.%文章研究了微腔OLED的视角特性,结果表明,亮度和发光效率随着视角的增加逐渐减小,当视角增加到50°时,其亮度降为正面输出的1/3;发光效率下降了约40%左右;色坐标随着视角的增加产生漂移,而光谱峰值和半高宽基本不随视角的变化而变化。同时分析并讨论了视角特性产生的原因。
Energy Technology Data Exchange (ETDEWEB)
Stueber, P; Wissel, T; Wagner, B [Institute for Robotics and Cognitive Systems, University of Luebeck, Luebeck (Germany); Graduate School for Computing in Life Science, University of Luebeck, Luebeck (Germany); Bruder, R; Schweikard, A; Ernst, F [Institute for Robotics and Cognitive Systems, University of Luebeck, Luebeck (Germany)
2014-06-01
Purpose: Recent research has shown that optical features significantly improve marker-less optical head-tracking for cranial radiotherapy. Simulations, however, showed that these optical features, which are used to derive tissue thickness, depend on the incident angle of the IR scanning laser beam and the perspective of the camera analyzing the reflective patterns. We present an experimental analysis determining which is the most robust optical setup concerning angular influences. Methods: In three consecutive experiments, the incident angle of the laser (1), the perspective of the camera (2) or both simultaneously (3, ‘inBeam’-perspective) were changed with respect to the target. We analyzed how this affects feature intensity. These intensities were determined from seven concentric regions of interest (ROIs) around the laser spot. Two targets were used: a tissue-like silicone phantom and a human's forehead. Results: For each experiment, the feature intensity generally decreases with increasing angle. We found that the optical properties of the silicone phantom do not fit the properties of human skin. Furthermore, the angular influence of the laser on the features is significantly higher than the perspective of the camera. With the ‘inBeam’- perspective, the smoothest decays of feature intensity were found. We suppose that this is because of a fixed relationship between both devices. This smoothness, suggesting a predictable functional relationship, may simplify angle compensation for machine learning algorithms. This is particularly prominent for the medial ROIs. The inner ROIs highly depend on the angle and power of the laser. The outer ROIs show less angular dependency but the signal strength is critically low and prone to artifacts. Therefore and because of the smooth decays, medial ROIs are a suitable tradeoff between susceptibility, signal-noise-ratio and distance to the center of the laser spot. Conclusion: For tissue thickness correlated
International Nuclear Information System (INIS)
Purpose: Recent research has shown that optical features significantly improve marker-less optical head-tracking for cranial radiotherapy. Simulations, however, showed that these optical features, which are used to derive tissue thickness, depend on the incident angle of the IR scanning laser beam and the perspective of the camera analyzing the reflective patterns. We present an experimental analysis determining which is the most robust optical setup concerning angular influences. Methods: In three consecutive experiments, the incident angle of the laser (1), the perspective of the camera (2) or both simultaneously (3, ‘inBeam’-perspective) were changed with respect to the target. We analyzed how this affects feature intensity. These intensities were determined from seven concentric regions of interest (ROIs) around the laser spot. Two targets were used: a tissue-like silicone phantom and a human's forehead. Results: For each experiment, the feature intensity generally decreases with increasing angle. We found that the optical properties of the silicone phantom do not fit the properties of human skin. Furthermore, the angular influence of the laser on the features is significantly higher than the perspective of the camera. With the ‘inBeam’- perspective, the smoothest decays of feature intensity were found. We suppose that this is because of a fixed relationship between both devices. This smoothness, suggesting a predictable functional relationship, may simplify angle compensation for machine learning algorithms. This is particularly prominent for the medial ROIs. The inner ROIs highly depend on the angle and power of the laser. The outer ROIs show less angular dependency but the signal strength is critically low and prone to artifacts. Therefore and because of the smooth decays, medial ROIs are a suitable tradeoff between susceptibility, signal-noise-ratio and distance to the center of the laser spot. Conclusion: For tissue thickness correlated feature
On solving the orientation gradient dependency of high angular resolution EBSD
Energy Technology Data Exchange (ETDEWEB)
Maurice, Claire, E-mail: maurice@emse.fr [Ecole des Mines de Saint-Etienne, UMR CNRS 5146 LCG, 158 cours Fauriel, F-42023 Saint-Etienne (France); Driver, Julian H. [Ecole des Mines de Saint-Etienne, UMR CNRS 5146 LCG, 158 cours Fauriel, F-42023 Saint-Etienne (France); Fortunier, Roland [Universite de Lyon, ENISE, UMR CNRS 5513 LTDS, 58 rue Jean Parot, F-42100 Saint-Etienne (France)
2012-02-15
Current high angular resolution electron backscatter diffraction (HR-EBSD) methods are successful at measuring pure elastic strains but have difficulties with plastically deformed metals containing orientation gradients. The strong influences of these rotations have been systematically studied using simulated patterns based on the many-beam dynamic theory of EBSP formation; a rotation of only 1 Degree-Sign can lead to apparent elastic strains of several hundred microstrains. A new method is proposed to correct for orientation gradient effects using a two-step procedure integrating finite strain theory: (i) reference pattern rotation and (ii) cross-correlation; it reduces the strain errors on the simulated patterns to tens of microstrains. An application to plastically deformed ferritic steel to generates elastic strain maps with significantly reduced values of both strains and residual errors in regions of rotations exceeding 1 Degree-Sign . -- Highlights: Black-Right-Pointing-Pointer Many-beam theory simulations show that HR-EBSD is sensitive to orientation gradients. Black-Right-Pointing-Pointer Finite strain theory and rotation processing the reference EBSP solves the problem. Black-Right-Pointing-Pointer New method succesfully applied to plastically strained IF steel.
Angular dependence of the facular-sunspot coverage relation as derived by MDI magnetograms
Criscuoli, Serena
2016-01-01
Previous studies have shown that the variation over the solar magnetic activity cycle of the area of facular/network features identified on broad band and narrow band imagery is positively correlated with the sunspot area and number, the relation between the area coverages being described as either linear or quadratic. On the other hand, the temporal variation of the spatial distributions of faculae, network and sunspots follows patterns that are less obviously correlated, so that we expect the relation that describes variation of the area coverage of different types of magnetic features to vary with the position over the disk. In this work we employ MDI full-disk magnetograms acquired during Cycle 23 and at the beginning of Cycle 24 to investigate the relation between the coverage of magnetic elements characterized by different amounts of magnetic flux and located at different angular distances from disk center with the sunspot number. In agreement with some previous studies we find that daily data are best ...
Angular and energy dependence of ion bombardment of Mo/Si multilayers
DEFF Research Database (Denmark)
Voorma, H.J.; Louis, E.; Bijkerk, F.;
1997-01-01
The process of ion bombardment is investigated for the fabrication of Mo/Si multilayer x-ray mirrors using e-beam evaporation. The ion treatment is applied immediately after deposition of each of the Si layers to smoothen the layers by removing an additional thickness of the Si layer. In this study....... The multilayer structures are analyzed further with small-angle reflectivity measurements using both specular reflectivity and diffuse x-ray scattering. The optimal smoothening parameters are obtained by determining the effect of ion bombardment on the interface roughness of the Si layer. The optimal...... roughness is determined by ion induced viscous flow, an effect which increases with ion energy as well as angle of incidence. In order to determine the effect of intermixing of the Si and Mo atoms, the penetration depth of the Kr+ ions is calculated as a function of ion energy and angle of incidence...
Angular dependence of energy and particle fluxes in a magnetized plasma
International Nuclear Information System (INIS)
A flat probe allowing simultaneous measurements of energy flux and current density as functions of a bias voltage was rotated in a spatially homogeneous plasma. The experiments were conducted at the PSI-2 facility, a linear divertor simulator with moderate magnetic field strength. Sheath parameters (ion current density j i, floating potential U f, energy flux density q, ion energy reflection coefficient R E and sheath energy transmission coefficient γ) were determined as functions of the angle α between the probe surface normal and the magnetic field. A geometric model has been developed to explain the ion flux density at grazing incidence
Angular dependence of the redeposition rates during SiO2 etching in a CF4 plasma
International Nuclear Information System (INIS)
The angular dependence of the redeposition rates during SiO2 etching in a CF4 plasma was studied using three types of Faraday cages located in a transformer coupled plasma etcher. The SiO2 substrates were fixed on sample holder slopes that have different angles to the cathode. The substrate was subjected to one of three processes depending on the design of the Faraday cage, i.e., redeposition of sputtered particles from the SiO2 bottom surface (case I), substrate etching by incident ions (case II), or simultaneous etching and redeposition (case III). Both the redeposition and the etch rates were measured by changing the substrate-surface angle and the self-bias voltage in the range of -100 to -800 V. The redeposition-only rates (case I) at -450 and -800 V closely followed the quadratic curve of the angle whereas the rates at -100 V followed the cubic curve, indicating different mechanisms of the bottom SiO2 etching depending on the energy regimes. The steep increase of the redeposition rate with the angle was attributed to three factors: the substrate-bottom distance, the angular distribution of emitted particles from the bottom surface, and the particle incident angle on the substrate surface. The etch-only rate curves (case II) closely followed the cosine of the surface angle. The etch-rate curve changed into a reverse-S shape when the substrate was subjected to simultaneous etching and redeposition (case III). The net etch rate for case III decreased drastically above 60 deg. , showing a negative value, i.e., a net redeposition, beyond 75 deg. . The drastic decrease in the net etch rate coincided with the steep increase in the redeposition rate, implying the significant effect of redeposition
Rozhkova, E. I.; Pivovarov, Yu. L.
2016-07-01
The Cherenkov radiation (ChR) angular distribution is usually described by the Tamm-Frank (TF) theory, which assumes that relativistic charged particle moves uniformly and rectilinearly in the optically transparent radiator. According to the TF theory, the full width at half maximum (FWHM) of the ChR angular distribution inversely depends on the radiator thickness. In the case of relativistic heavy ions (RHI) a slowing-down in the radiator may sufficiently change the angular distribution of optical radiation in vicinity of the Cherenkov cone, since there appears a mixed ChR-Bremsstrahlung radiation. As a result, there occurs a drastic transformation of the FWHM of optical radiation angular distribution in dependence on the radiator thickness: from inversely proportional (TF theory) to the linearly proportional one. In our paper we present the first analysis of this transformation taking account of the gradual velocity decrease of RHI penetrating through a radiator.
Mirzanian, S. M.; Shokri, A. A.; Mikaili Agah, K.; Elahi, S. M.
2015-09-01
We investigate theoretically the effects of Dresselhaus spin-orbit coupling (DSOC) on the spin-dependent current and shot noise through II-VI diluted magnetic semiconductor/nonmagnetic semiconductor (DMS/NMS) barrier structures. The calculation of transmission probability is based on an effective mass quantum-mechanical approach in the presence of an external magnetic field applied along the growth direction of the junction and also applied voltage. We also study the dependence of spin-dependent properties on external magnetic field and relative angle between the magnetizations of two DMS layers in CdTe/CdMnTe heterostructures by including the DSOC effect. The results show that the DSOC has great different influence on transport properties of electrons with spin up and spin down in the considered system and this aspect may be utilized in designing new spintronics devices.
Angular dependence of L X-rays emission for Ag by 10 keV electron-impact
Wang, Xing; Xu, Zhongfeng; Zhang, Ying; Ma, Chao; Zhu, Chengwei
2016-08-01
The characteristic X-ray intensities of Ag-Lα, Lβ1, Lβ2 and Lγ1 are measured in electron-impact ionization at energy of 10 keV. The emission angle in this work ranges from 0° to 20° at interval of 5°. The angular dependence of L X-ray intensity ratios has been investigated for Lα / Lβ1, Lβ2 / Lβ1 and Lγ1 / Lβ1. It is found from the experimental results that the emissions of Lβ1, Lβ2 and Lγ1 X-rays are spatially isotropic, while the Lα X-rays exhibit anisotropic emission. Consequently, the alignment behavior of vacancy states is discussed with thorough analysis of vacancy transfer process.
International Nuclear Information System (INIS)
We report on the results of measurements of the angular dependence of magnetization of high-Tc superconducting YBa2Cu3O7-δ and La1.85Sr0.15CuO4 thin films and superconducting/ferromagnetic YBa2Cu3O7-δ/Nd0.76Sr0.33MnO3 superlattices. We compare our present results to our results, previously obtained for YBa2Cu3O7-δ and Bi2Sr2CaCu2O8 single crystals. We discuss the influence of the presence of Nd0.67Sr0.33MnO3 sublayers in YBa2Cu3O7-δ/Nd0.67Sr0.33MnO3 superlattices on the critical temperature, flux pinning, and the critical field for the first vortex penetration. (orig.)
International Nuclear Information System (INIS)
Energy-dependent photoelectron angular distributions from two-color two-photon above threshold ionizations are investigated to determine the partial-wave characteristics of free-free electronic transitions in helium. Sideband photoelectron energies ranging from 0.18 to 13.0 eV are measured with different wavelengths of the perturbative infrared dressing field as well as different individually selected high-order harmonics. Using the experimentally measured cross-section ratios and anisotropy parameters together with analytical expressions derived from second-order perturbation theory, the partial-wave branching fractions going to the S and D waves in the positive and negative sidebands are determined as a function of photoelectron kinetic energy. The results provide a sensitive test for theoretical models of two-color two-photon above threshold ionization in atoms and molecules.
Angular dependence of transport current near critical at fields to 4 T in metalorganic thin films
International Nuclear Information System (INIS)
Values of the transport current have been obtained as a function of angle of the magnetic field to the plane of the thin film YBa2Cu3O7-d (YBCO) prepared by metalorganic deposition. Current flowed in the a.b planes at various angles to the applied magnetic fields to 4.2 T. Films with thicknesses near 350 nm were studied. For these thin films and H|c a secondary maximum is observed when Jc > 1 MA/cm2. Near H|a, b a large increase in Ic is observed, and the sharpness, field dependence, and field directional dependence is discussed. The response to currents above Ic is determined and the fit to a power law V approximately In shows a strong correlation between Ic and n. 14 refs., 11 figs., 1 tab
Effect of Angular Velocity on Sensors Based on Morphology Dependent Resonances
Ali, Amir R.; Tindaro Ioppolo
2014-01-01
We carried out an analysis to investigate the morphology dependent optical resonances shift (MDR) of a rotating spherical resonator. The spinning resonator experiences an elastic deformation due to the centrifugal force acting on it, leading to a shift in its MDR. Experiments are also carried out to demonstrate the MDR shifts of a spinning polydimethylsiloxane (PDMS) microsphere. The experimental results agree well with the analytical prediction. These studies demonstrated that spinning senso...
Angular Dependence of ϕ Meson Production for Different Photon Beam Energies
International Nuclear Information System (INIS)
The dependence of ϕ-meson photoproduction on the polar angle is investigated in the framework of a multisource thermal model. We present a detailed comparison between our results and experimental data of the neutral decay mode in the reaction γp→pϕ(KSKL). The results are in good agreement with the experimental data. It is found that the movement factor bz increases linearly with the photon beam energies
Chen, Jian; Bai, Xiaolong; Yang, Keji; Ju, Bing-Feng
2012-01-01
For inspection of mechanical properties and integrity of critical components such as integrated circuits or composite materials by acoustic methodology, it is imperative to evaluate their acoustic reflection coefficients, which are in close correlation with the elastic properties, thickness, density, and attenuation and interface adhesion of these layered structures. An experimental method based on angular spectrum to evaluate the acoustic coefficient as a function of the incident angle, θ, and frequency, ω, is presented with high frequency time-resolved acoustic microscopy. In order to achieve a high spatial resolution for evaluation of thin plates with thicknesses about one or two wavelengths, a point focusing transducer with a nominal center frequency of 25 MHz is adopted. By measuring the V(z, t) data in pulse mode, the reflection coefficient, R(θ, ω), can be reconstructed from its two-dimensional spectrum. It brings simplicity to experimental setup and measurement procedure since only single translation of the transducer in the vertical direction is competent for incident angle and frequency acquisition. It overcomes the disadvantages of the conventional methods requiring the spectroscopy for frequency scanning and/or ultrasonic goniometer for angular scanning. Two substrates of aluminum and Plexiglas and four stainless plates with various thicknesses of 100 μm, 150 μm, 200 μm, and 250 μm were applied. The acoustic reflection coefficients are consistent with the corresponding theoretical calculations. It opened the way of non-destructive methodology to evaluate the elastic and geometrical properties of very thin multi-layers structures simultaneously.
Masir, M. Ramezani; Vasilopoulos, P.; Matulis, A.; Peeters, F. M.
2010-01-01
We evaluate the transmission through magnetic barriers in graphene-based nanostructures. Several particular cases are considered: a magnetic step, single and double barriers, δ -function barriers as well as barrier structures with inhomogeneous magnetic field profiles but with average magnetic field equal to zero. The transmission exhibits a strong dependence on the direction of the incident wave vector. In general the resonant structure of the transmission is significantly more pronounced for (Dirac) electrons with linear spectrum compared to that for electrons with a parabolic one.
YouLiang Jing; ZhiFeng Li; Qian Li; PingPing Chen; XiaoHao Zhou; Han Wang; Ning Li; Wei Lu
2016-01-01
We report the dependence of the near-field optical modes in metal-insulator-metal quantum well infrared photodetector (MIM-QWIP) on the incident angles. Three optical modes are observed and attributed to the 2nd- and the 3rd-order surface plasmon polariton (SPP) modes and the localized surface polariton (LSP) mode. In addition to the observation of a responsivity enhancement of 14 times by the LSP mode, the varying pattern of the three modes against the incident angle are revealed, in which t...
THE MASS-DEPENDENCE OF ANGULAR MOMENTUM EVOLUTION IN SUN-LIKE STARS
Energy Technology Data Exchange (ETDEWEB)
Matt, Sean P.; Baraffe, Isabelle; Chabrier, Gilles [Department of Physics and Astronomy, University of Exeter, Physics Building, Stocker Road, Exeter, EX4 4QL (United Kingdom); Brun, A. Sacha [Laboratoire AIM Paris-Saclay, CEA/Irfu Université Paris-Diderot CNRS/INSU, F-91191 Gif-sur-Yvette (France); Bouvier, Jérôme, E-mail: s.matt@exeter.ac.uk [Université de Grenoble Alpes, IPAG, F-38000 Grenoble (France)
2015-02-01
To better understand the observed distributions of the rotation rate and magnetic activity of Sun-like and low-mass stars, we derive a physically motivated scaling for the dependence of the stellar wind torque on the Rossby number. The torque also contains an empirically derived scaling with stellar mass (and radius), which provides new insight into the mass-dependence of stellar magnetic and wind properties. We demonstrate that this new formulation explains why the lowest mass stars are observed to maintain rapid rotation for much longer than solar-mass stars, and simultaneously why older populations exhibit a sequence of slowly rotating stars, in which the low-mass stars rotate more slowly than solar-mass stars. The model also reproduces some previously unexplained features in the period-mass diagram for the Kepler field, notably: the particular shape of the ''upper envelope'' of the distribution, suggesting that ∼95% of Kepler field stars with measured rotation periods are younger than ∼4 Gyr; and the shape of the ''lower envelope'', corresponding to the location where stars transition between magnetically saturated and unsaturated regimes.
Angular dependence and symmetry of Rashba spin torque in ferromagnetic heterostructures
Ortiz Pauyac, Christian
2013-06-26
In a ferromagnetic heterostructure, the interplay between Rashba spin-orbit coupling and exchange splitting gives rise to a current-driven spin torque. In a realistic device setup, we investigate the Rashba spin torque in the diffusive regime and report two major findings: (i) a nonvanishing torque exists at the edges of the device even when the magnetization and effective Rashba field are aligned; (ii) anisotropic spin relaxation rates driven by the Rashba spin-orbit coupling assign the spin torque a general expression T = T y (θ) m × (y × m) + T y (θ) y × m + T z (θ) m × (z × m) + T z (θ) z × m, where the coefficients T, y, z depend on the magnetization direction. Our results agree with recent experiments. © 2013 AIP Publishing LLC.
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General expressions of the electron yield in 57Fe integral conversion electron Mössbauer spectroscopy were derived depending on the glancing angle of the γ photons, on the source polarization and on the isotopic abundance of the source and the absorber (blackness effects) using an exponential escape function of the electrons originating from all Mössbauer-resonance-related processes. The present approach provides a firm theoretical basis to determine the alignment and direction of magnetization in the absorber. The intensity formulae were justified by least squares fits of α-57Fe spectral intensities measured in linearly and elliptically polarized source and absorber geometries. The fits reproduce the experimentally set angles with high accuracy. Limits of the current approach and its relation to other, less complete treatments in the literature are discussed
Simulations of the angular dependence of the dipole–dipole interaction among Rydberg atoms
Bigelow, Jacob L.; Paul, Jacob T.; Peleg, Matan; Sanford, Veronica L.; Carroll, Thomas J.; Noel, Michael W.
2016-08-01
The dipole–dipole interaction between two Rydberg atoms depends on the relative orientation of the atoms and on the change in the magnetic quantum number. We simulate the effect of this anisotropy on the energy transport in an amorphous many atom system subject to a homogeneous applied electric field. We consider two experimentally feasible geometries and find that the effects should be measurable in current generation imaging experiments. In both geometries atoms of p character are localized to a small region of space which is immersed in a larger region that is filled with atoms of s character. Energy transfer due to the dipole–dipole interaction can lead to a spread of p character into the region initially occupied by s atoms. Over long timescales the energy transport is confined to the volume near the border of the p region which suggests Anderson localization. We calculate a correlation length of 6.3 μm for one particular geometry.
Angular and Frequency-Dependent Wave Velocity and Attenuation in Fractured Porous Media
Carcione, José M.; Gurevich, Boris; Santos, Juan E.; Picotti, Stefano
2013-11-01
Wave-induced fluid flow generates a dominant attenuation mechanism in porous media. It consists of energy loss due to P-wave conversion to Biot (diffusive) modes at mesoscopic-scale inhomogeneities. Fractured poroelastic media show significant attenuation and velocity dispersion due to this mechanism. The theory has first been developed for the symmetry axis of the equivalent transversely isotropic (TI) medium corresponding to a poroelastic medium containing planar fractures. In this work, we consider the theory for all propagation angles by obtaining the five complex and frequency-dependent stiffnesses of the equivalent TI medium as a function of frequency. We assume that the flow direction is perpendicular to the layering plane and is independent of the loading direction. As a consequence, the behaviour of the medium can be described by a single relaxation function. We first consider the limiting case of an open (highly permeable) fracture of negligible thickness. We then compute the associated wave velocities and quality factors as a function of the propagation direction (phase and ray angles) and frequency. The location of the relaxation peak depends on the distance between fractures (the mesoscopic distance), viscosity, permeability and fractures compliances. The flow induced by wave propagation affects the quasi-shear (qS) wave with levels of attenuation similar to those of the quasi-compressional (qP) wave. On the other hand, a general fracture can be modeled as a sequence of poroelastic layers, where one of the layers is very thin. Modeling fractures of different thickness filled with CO2 embedded in a background medium saturated with a stiffer fluid also shows considerable attenuation and velocity dispersion. If the fracture and background frames are the same, the equivalent medium is isotropic, but strong wave anisotropy occurs in the case of a frameless and highly permeable fracture material, for instance a suspension of solid particles in the fluid.
Angular Dependence of Jet Quenching Indicates Its Strong Enhancement Near the QCD Phase Transition
Energy Technology Data Exchange (ETDEWEB)
Liao, Jinfeng; Shuryak, Edward
2008-10-22
We study dependence of jet quenching on matter density, using 'tomography' of the fireball provided by RHIC data on azimuthal anisotropy v{sub 2} of high p{sub t} hadron yield at different centralities. Slicing the fireball into shells with constant (entropy) density, we derive a 'layer-wise geometrical limit' v{sub 2}{sup max} which is indeed above the data v{sub 2} < v{sub x}{sup max}. Interestingly, the limit is reached only if quenching is dominated by shells with the entropy density exactly in the near-T{sub c} region. We show two models that simultaneously describe the high p{sub t} v{sub 2} and R{sub AA} data and conclude that such a description can be achieved only if the jet quenching is few times stronger in the near-T{sub c} region relative to QGP at T > T{sub c}. One possible reason for that may be recent indications that the near-T{sub c} region is a magnetic plasma of relatively light color-magnetic monopoles.
Directory of Open Access Journals (Sweden)
YouLiang Jing
2016-04-01
Full Text Available We report the dependence of the near-field optical modes in metal-insulator-metal quantum well infrared photodetector (MIM-QWIP on the incident angles. Three optical modes are observed and attributed to the 2nd- and the 3rd-order surface plasmon polariton (SPP modes and the localized surface polariton (LSP mode. In addition to the observation of a responsivity enhancement of 14 times by the LSP mode, the varying pattern of the three modes against the incident angle are revealed, in which the LSP mode is fixed while the 2nd SPP mode splits into two branches and the 3rd SPP mode red-shifts. The detailed mechanisms are analyzed and numerically simulated. The results fit the experiments very well, demonstrating the wavevector coupling effect between the incident light and the metal gratings on the SPP modes. Our work will pave the way to fully understanding the influence of incident angles on a detector’s response for applying the MIM-QWIP to focal plane arrays.
Jing, YouLiang; Li, ZhiFeng; Li, Qian; Chen, PingPing; Zhou, XiaoHao; Wang, Han; Li, Ning; Lu, Wei
2016-04-01
We report the dependence of the near-field optical modes in metal-insulator-metal quantum well infrared photodetector (MIM-QWIP) on the incident angles. Three optical modes are observed and attributed to the 2nd- and the 3rd-order surface plasmon polariton (SPP) modes and the localized surface polariton (LSP) mode. In addition to the observation of a responsivity enhancement of 14 times by the LSP mode, the varying pattern of the three modes against the incident angle are revealed, in which the LSP mode is fixed while the 2nd SPP mode splits into two branches and the 3rd SPP mode red-shifts. The detailed mechanisms are analyzed and numerically simulated. The results fit the experiments very well, demonstrating the wavevector coupling effect between the incident light and the metal gratings on the SPP modes. Our work will pave the way to fully understanding the influence of incident angles on a detector's response for applying the MIM-QWIP to focal plane arrays.
Yamada, Takahiro; Kawada, Yasushi; Ishizu, Hidetake; Yamamoto, Shinich; Yunoki, Akira; Sato, Yasushi; Unno, Yasuhiro; Hino, Yoshio
2012-09-01
Calibrations of instrument efficiency of surface contamination meters are usually made with extended reference sources which are standardized in terms of 2π surface β-particle emission rates from the source surface including backscattered particles. Extended sources supplied from various metrology institutes or calibration laboratories, but the source-types such as structure, preparation method, backing and covering materials vary between manufacturers. In this work first we show how the calibration results are dependent on the source type. Second, in order to clarify the possible reason of such discrepancy, we examined the isotropy of β-particle fluences by the use of a proportional counter and also observed the angular dependence of β-particle spectra by the use of small plastic scintillation spectrometer, where the source mount can rotate relative to the detector window at various obliquities. The discrepancy in the instrument-calibration of surface contamination meters, which are mainly used under the conditions of large source-to-detector geometry, can be explained. PMID:22424745
Takahashi, Kayori; Kato, Haruhisa; Kinugasa, Shinichi
2011-01-01
A standard method for nanoparticle sizing based on the angular dependence of dynamic light scattering was developed. The dependences of the diffusion coefficients for aqueous suspensions of polystyrene latex on the concentration and scattering angle were accurately measured by using a high-resolution dynamic light-scattering instrument. Precise measurements of the short-time correlation function at seven scattering angles and five concentrations were made for suspensions of polystyrene latex particles with diameters from 30 to 100 nm. The apparent diffusion coefficients obtained at various angles and concentrations showed properties characteristic of polystyrene latex particles with electrostatic interactions. A simulation was used to calculate a dynamic structure factor representing the long-range interactions between particles. Extrapolations to infinite dilution and to low angles gave accurate particle sizes by eliminating the effects of long-range interactions. The resulting particle sizes were consistent with those measured by using a differential mobility analyzer and those obtained by pulsed-field gradient nuclear magnetic resonance measurements. PMID:21747185
Yasuzuka, Syuma; Uji, Shinya; Konoike, Takako; Terashima, Taichi; Graf, David; Choi, Eun Sang; Brooks, James S.; Yamamoto, Hiroshi M.; Kato, Reizo
2016-08-01
This paper reports the experimental results of the Shubnikov-de Haas (SdH) effect and angular-dependent magnetoresistance oscillation (AMRO) for the organic conductor β''-(ET)(TCNQ). We observed several two dimensional (2D) SdH frequencies, whose cross-sectional areas of the Fermi surfaces (FSs) correspond to only a few percent of the first Brillouin zone. Such small 2D FSs are not predicted by band-structure calculations, suggesting that these FS pockets are created by an imperfect nesting of FSs at low temperatures. It is found that the AMRO consists of a long-period oscillation and a short-period one. The long-period oscillation is associated with the Yamaji oscillation corresponding to the α orbit, whose shape and area are consistent with previous magneto-optical measurement. The short-period oscillation is not caused by peaks instead but dips. The dip structure is discussed in terms of the AMRO of a quasi-2D electron system with a periodic potential caused by the possible density-wave related to the ET layers or the 4kF charge-density-wave associated with the TCNQ layers.
International Nuclear Information System (INIS)
We investigate the impact of nonlinear evolution of the gravitational potentials in the ΛCDM model on the integrated Sachs-Wolfe (ISW) contribution to the cosmic microwave background (CMB) temperature power spectrum, and on the cross-power spectrum of the CMB and a set of biased tracers of the mass. We use an ensemble of N-body simulations to directly follow the potentials and compare the results to analytic PT methods. The predictions from the PT match the results to high precision for k-1. We compute the nonlinear corrections to the angular power spectrum and find them to be 100 the departures are more significant; however, the CMB signal is more than a factor 103 larger at this scale. Nonlinear ISW effects therefore play no role in shaping the CMB power spectrum for lm(z)<0.3. Numerical results confirm these expectations and we find no sign change in ISW large-scale structure cross power for low redshifts. Corrections due to nonlinearity and scale dependence of the bias are found to be <10% for l<100, and are therefore below the signal to noise of the current and future measurements. Finally, we estimate the cross-correlation coefficient between the CMB and halos and show that it can be made to match that for the dark matter and CMB to within 5% for thin redshift shells, thus mitigating the need to model bias evolution.
Angular dependence of ferromagnetic resonance in Tb-doped Ni{sub 80}Fe{sub 20} thin films
Energy Technology Data Exchange (ETDEWEB)
Luo, Chen [Physics Department, Southeast University, Nanjing 211189 (China); Zhang, Dong [Physics Department, Southeast University, Nanjing 211189 (China); School of Physics Science and Information Engineering, Liaocheng University, Liaocheng 252059 (China); Wang, Yukun [Physics Department, Southeast University, Nanjing 211189 (China); Huang, Haibo [College of Material Science and Engineering, Southeast University, Nanjing 211189 (China); Zhai, Ya, E-mail: yazhai@seu.edu.cn [Physics Department, Southeast University, Nanjing 211189 (China); Zhai, Hongru [National Laboratory of Solid Microstructures, Nanjing University, Nanjing 210093 (China)
2014-06-15
Highlights: • The soft magnetic properties of Ni{sub 80}Fe{sub 20} films with Tb dopants up to 8.4% are kept. • The different mechanisms of FMR linewidth are separated and studied. • Magnetic anisotropy constants, Lande g factor, etc. are discussed quantitatively. • The Gilbert damping is increased by more than 50 times with 8.4% of Tb dopants. - Abstract: The mechanisms of angular dependence of ferromagnetic resonance (FMR) linewidth of dilute Tb doping in Ni{sub 80}Fe{sub 20} thin films are investigated by experimental approach and the theoretical fitting by considering the contributions from intrinsic spin–orbit coupling, two-magnon scattering and inhomogeneous broadening. It is shown that the damping coefficient α, by intrinsic contribution extracted from FMR linewidth, is increased by more than 50 times as the Tb concentration increases to 8.4%, indicating that the spin–orbit coupling of this system increases with the introduction of Tb impurities. The magnetic anisotropy constants K{sub 1} and K{sub 2} are obtained and show an increasing trend from negative to positive, which implies that the Tb dopants could enhance the perpendicular anisotropy.
Energy Technology Data Exchange (ETDEWEB)
Kolesnik, S.; Skoskiewicz, T.; Przyslupski, P.; Cieplak, M.Z. [Polska Akademia Nauk, Warsaw (Poland). Inst. Fizyki
2000-07-01
We report on the results of measurements of the angular dependence of magnetization of high-T{sub c} superconducting YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} and La{sub 1.85}Sr{sub 0.15}CuO{sub 4} thin films and superconducting/ferromagnetic YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}/Nd{sub 0.76}Sr{sub 0.33}MnO{sub 3} superlattices. We compare our present results to our results, previously obtained for YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} and Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8} single crystals. We discuss the influence of the presence of Nd{sub 0.67}Sr{sub 0.33}MnO{sub 3} sublayers in YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}/Nd{sub 0.67}Sr{sub 0.33}MnO{sub 3} superlattices on the critical temperature, flux pinning, and the critical field for the first vortex penetration. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Schmitt, R.P.
1978-05-01
The dependence of deep-inelastic processes on entrance channel asymmetry and on excitation energy was investigated. Thin targets of /sup nat/At, /sup 159/Tb, /sup 181/Ta and /sup 197/Au were bombarded with 620 MeV /sup 86/Kr ions. Additional measurements were performed on the reactions /sup nat/Ag + /sup 86/Kr and /sup 197/Au + /sup 86/Kr at 506 and 732 MeV incident energy. The energy spectra, the charge distributions and the angular distributions of these fragments were measured. At 620 MeV the energy spectra show that the distinction between quasi-elastic and deep-inelastic processes diminishes as the target mass is increased. The charge distributions, which are peaked at symmetry for /sup nat/Ag, tend to become increasingly asymmetric for the heavier systems. Likewise, the angular distributions exhibit a strong dependence on the entrance channel asymmetry. For the lightest system, /sup nat/Ag + /sup 86/Kr, the angular distributions are essentially forward peaked, aside from a separable quasi-elastic component. For the heaviest system, /sup 197/Au + /sup 86/Kr, the angular distributions are side-peaked. The transition between these two regimes occurs smoothly with increasing target mass. The results at 506 and 732 MeV show that the widths of the charge distributions are strongly dependent on the excitation energy. The angular distributions for the reaction /sup nat/Ag + /sup 86/Kr become increasingly more forward peaked at higher bombarding energies. The angular distributions for /sup 197/Au + /sup 86/Kr, which are strongly focused at 506 MeV, also tend to be more forward peaked at the highest incident energy. The results are interpreted by assuming that the projectile and target form an intermediate complex and that they exchange mass via a diffusion process. Because of the systematic nature of this study, the data should serve as a guide in the development of models of deep-inelastic processes.
International Nuclear Information System (INIS)
We present measurements of electron-impact excitation cross sections into levels of the 4p55p configuration from the J=0 and J=2 metastable levels of krypton. Metastable-atom targets were generated using two different sources, a hollow-cathode discharge and via charge-exchange collisions between a fast Kr+ beam and Cs atoms. The metastable atoms are excited to 4p55p levels by a monoenergetic electron beam and the fluorescence from the levels are used to determine the excitation cross sections. Laser quenching of the hollow-cathode target is used to separate the signal contributions from excitation of the two metastable levels. Like excitation from the metastable levels of Ar, cross sections for dipole-allowed excitations are generally larger than ones for dipole-forbidden excitations. Krypton differs from Ar and Ne, however, in having a larger spin-orbit coupling for the 4p5 core so that the energy levels of each excited configuration segregate into two tiers based on the value of the core angular momentum. Cross sections for dipole-allowed excitation with a change in the core angular momentum are not only much smaller than their core-preserving counterparts, but also have different energy dependence. The measured cross sections are compared with recent theoretical calculations and with previous experimental work
Time-Dependent and Time-Integrated Angular Analysis of B -> phi Ks pi0 and B -> phi K+ pi-
Energy Technology Data Exchange (ETDEWEB)
Aubert, B; Bona, M; Karyotakis, Y; Lees, J P; Poireau, V
2008-08-04
We perform a time-dependent and time-integrated angular analysis of the B{sup 0} {yields} {psi}K*(892){sup 0}, {psi}K*{sub 2}(1430{sup 0}), and {psi}(K{pi}){sub S-wave}{sup 0} decays with the final sample of about 465 million B{bar B} pairs recorded with the BABAR detector. Overall, twelve parameters are measured for the vector-vector decay, nine parameters for the vector-tensor decay, and three parameters for the vector-scalar decay, including the branching fractions, CP-violation parameters, and parameters sensitive to final state interaction. We use the dependence on the K{pi} invariant mass of the interference between the scalar and vector or tensor components to resolve discrete ambiguities of the strong and weak phases. We use the time-evolution of the B {yields} {psi}K{sub S}{sup 0}{pi}{sup 0} channel to extract the CP-violation phase difference {Delta}{phi}{sub 00} = 0.28 {+-} 0.42 {+-} 0.04 between the B and {bar B} decay amplitudes. When the B {yields} {psi}K{sup {+-}}{pi}{sup {-+}} channel is included, the fractions of longitudinal polarization f{sub L} of the vector-vector and vector-tensor decay modes are measured to be 0.494 {+-} 0.034 {+-} 0.013 and 0.901{sub -0.058}{sup +0.046} {+-} 0.037, respectively. This polarization pattern requires the presence of a helicity-plus amplitude in the vector-vector decay from a presently unknown source.
International Nuclear Information System (INIS)
The temperature and angular dependences of upper critical fields H/sub c2/ have been measured for several 2H-NbSe2 single crystals by use of an electrical conduction method in magnetic fields up to 150 kOe. As the temperature approaches the transition temperature T/sub c/, the value of H/sub c2 parallel/ (parallel to the layer planes) decreases with a positive curvature, while the value of H/sub c2 perpendicular/ (perpendicular to the layer planes) decreases almost linearly. The ratio of H/sub c2 parallel/ to H/sub c2 perpendicular/ increases monotonically from 2.4 near T/sub c/ with decreasing temperature and reaches the constant value of 3.2 at the lowest temperature. It becomes clear that the simple effective mass model based on the anisotropic Ginzburg--Landau theory does not explain our experimental results. The anisotropic behavior of H/sub c2/ can be accounted for by the Takanaka theory, which includes anisotropies of both the Fermi velocity and the energy gap and the effect of nonlocality. Agreement between experimental results and the theoretical prediction is obtained by the use of values of 0.16 approximately less than epsilon12 approximately less than 0.25 and -0.6 approximately less than epsilon2 approximately less than -0.3, where epsilon1 is the mass anisotropy parameter and epsilon2 the gap anisotropy parameter. The coupling strength between layers is too strong to be explained by the Josephson phase coupling model proposed for quasi-two-dimensional layer superconductors
International Nuclear Information System (INIS)
Highlights: • We construct and analyze random and crystal arrangements of pebble bed cores. • We investigate anisotropic diffusion of neutrons in the interior of the cores. • We generate benchmark numerical results using Monte Carlo. • We obtain model estimates for the anisotropic diffusion coefficients. • We find that the new theory is accurate and able to predict anisotropic diffusion. - Abstract: We describe an analysis of neutron transport in the interior of model pebble bed reactor (PBR) cores, considering both crystal and random pebble arrangements. Monte Carlo codes were developed for (i) generating random realizations of the model PBR core, and (ii) performing neutron transport inside the crystal and random heterogeneous cores; numerical results are presented for two different choices of material parameters. These numerical results are used to investigate the anisotropic behavior of neutrons in each case and to assess the accuracy of estimates for the diffusion coefficients obtained with the diffusion approximations of different models: the atomic mix model, the Behrens correction, the Lieberoth correction, the generalized linear Boltzmann equation (GLBE), and the new GLBE with angular-dependent path-length distributions. This new theory utilizes a non-classical form of the Boltzmann equation in which the locations of the scattering centers in the system are correlated and the distance-to-collision is not exponentially distributed; this leads to an anisotropic diffusion equation. We show that the results predicted using the new GLBE theory are extremely accurate, correctly identifying the anisotropic diffusion in each case and greatly outperforming the other models for the case of random systems
High-Order Non-Reflecting Boundary Scheme for Time-Dependent Waves
Givoli, Dan; Neta, Beny
2002-01-01
A new non-reflecting boundary scheme is proposed for time-dependent wave problems in unbounded domains. The linear time-dependent wave equation, with or without a disper- sive term, is considered outside of an obstacle or in a semi-infinite wave guide. The infinite domain is truncated via an artificial boundary B, and a high-order Non-Reflecting Boundary Condition (NRBC) is imposed on B. Then the problem is solved numerically in the finite domain bounded by B. The new boundary scheme is based...
Effect of Fresnel Reflectivity in a Spherical Turbid Medium
International Nuclear Information System (INIS)
Radiative transfer problem for anisotropic scattering in a spherical homogeneous, turbid medium with angular dependent (specular) reflecting boundary is solved using the pomraning-Eddington approximation method. The angular dependent reflectivity of the boundary is considered as Fresnel's reflection probability function. The partial heat flux is calculated with anisotropic scattering through a homogeneous solid sphere. our results are compared with the available data and give an excellent agreement
International Nuclear Information System (INIS)
When performing dose measurements on an X-ray device with multiple angles of irradiation, it is necessary to take the angular dependence of metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters into account. The objective of this study was to investigate the angular sensitivity dependence of MOSFET dosimeters in three rotational axes measured free-in-air and in soft-tissue equivalent material using dental photon energy. Free-in-air dose measurements were performed with three MOSFET dosimeters attached to a carbon fibre holder. Soft tissue measurements were performed with three MOSFET dosimeters placed in a polymethylmethacrylate (PMMA) phantom. All measurements were made in the isocenter of a dental cone-beam computed tomography (CBCT) scanner using 5° angular increments in the three rotational axes: axial, normal-to-axial and tangent-to-axial. The measurements were referenced to a RADCAL 1015 dosimeter. The angular sensitivity free-in-air (1 SD) was 3.7 ± 0.5 mV/mGy for axial, 3.8 ± 0.6 mV/mGy for normal-to-axial and 3.6 ± 0.6 mV/mGy for tangent-to-axial rotation. The angular sensitivity in the PMMA phantom was 3.1 ± 0.1 mV/mGy for axial, 3.3 ± 0.2 mV/mGy for normal-to-axial and 3.4 ± 0.2 mV/mGy for tangent-to-axial rotation. The angular sensitivity variations are considerably smaller in PMMA due to the smoothing effect of the scattered radiation. The largest decreases from the isotropic response were observed free-in-air at 90° (distal tip) and 270° (wire base) in the normal-to-axial and tangent-to-axial rotations, respectively. MOSFET dosimeters provide us with a versatile dosimetric method for dental radiology. However, due to the observed variation in angular sensitivity, MOSFET dosimeters should always be calibrated in the actual clinical settings for the beam geometry and angular range of the CBCT exposure. (author)
Koivisto, Juha; Kiljunen, Timo; Wolff, Jan; Kortesniemi, Mika
2013-09-01
When performing dose measurements on an X-ray device with multiple angles of irradiation, it is necessary to take the angular dependence of metal-oxide-semiconductor field-effect transistor (MOSFET) dosimeters into account. The objective of this study was to investigate the angular sensitivity dependence of MOSFET dosimeters in three rotational axes measured free-in-air and in soft-tissue equivalent material using dental photon energy. Free-in-air dose measurements were performed with three MOSFET dosimeters attached to a carbon fibre holder. Soft tissue measurements were performed with three MOSFET dosimeters placed in a polymethylmethacrylate (PMMA) phantom. All measurements were made in the isocenter of a dental cone-beam computed tomography (CBCT) scanner using 5º angular increments in the three rotational axes: axial, normal-to-axial and tangent-to-axial. The measurements were referenced to a RADCAL 1015 dosimeter. The angular sensitivity free-in-air (1 SD) was 3.7 ± 0.5 mV/mGy for axial, 3.8 ± 0.6 mV/mGy for normal-to-axial and 3.6 ± 0.6 mV/mGy for tangent-to-axial rotation. The angular sensitivity in the PMMA phantom was 3.1 ± 0.1 mV/mGy for axial, 3.3 ± 0.2 mV/mGy for normal-to-axial and 3.4 ± 0.2 mV/mGy for tangent-to-axial rotation. The angular sensitivity variations are considerably smaller in PMMA due to the smoothing effect of the scattered radiation. The largest decreases from the isotropic response were observed free-in-air at 90° (distal tip) and 270° (wire base) in the normal-to-axial and tangent-to-axial rotations, respectively. MOSFET dosimeters provide us with a versatile dosimetric method for dental radiology. However, due to the observed variation in angular sensitivity, MOSFET dosimeters should always be calibrated in the actual clinical settings for the beam geometry and angular range of the CBCT exposure. PMID:23520268
International Nuclear Information System (INIS)
The method for calculation of energy dependence of fusion (in general case the sum of complete and incomplete fusion, quasi fission and deep inelastic collisions) and total peripheral reaction cross sections is developed on the basis of finite set of elastic scattering angular distributions analysis for given pair of nuclei. Predictive possibilities of the method are illustrated for the 16O+208Pb system, for which calculations are made in the laboratory energy interval Elab = 70 - 450 MeV
Garraffo, Cecilia; Cohen, Ofer
2015-01-01
Rotation evolution of late-type stars is dominated by magnetic braking and the underlying factors that control this angular momentum loss are important for the study of stellar spin-down. In this work, we study angular momentum loss as a function of two different aspects of magnetic activity using a calibrated Alfv\\'en wave-driven magnetohydrodynamic wind model: the strengths of magnetic spots and their distribution in latitude. By driving the model using solar and modified solar surface magnetograms, we show that the topology of the field arising from the net interaction of both small-scale and large-scale field is important for spin-down rates and that angular momentum loss is not a simple function of large scale magnetic field strength. We find that changing the latitude of magnetic spots can modify mass and angular momentum loss rates by a factor of two. The general effect that causes these differences is the closing down of large-scale open field at mid- and high-latitudes by the addition of the small-sc...
International Nuclear Information System (INIS)
The fission of 210Po, produced by three different nuclear reactions (209Bi + p, 206Pb + α and 198Pt + 12C), has been studied in detail in order to establish the dependence of various scission-point properties on the excitation energy and angular-momentum distribution of the fissioning nucleus. Excitation energies of 31, 44 and 57 MeV were chosen so as to give reasonable fission cross-sections, while avoiding a large contribution from second chance fission. The experiments were conducted on a beam line of the Harwell Variable Energy Cyclotron. The mean-fragment total-kinetic-energy release was found to be dependent on the 210Po excitation energy and angular-momentum distribution. The variances of the total-kinetic energy and mass distributions were found to be a strongly dependent on excitation energy but not on angular momentum. The experimental results of this work were found to be in good agreement with the theoretical liquid-drop-model calculations of Nix and Swiatecki. (author)
Microwave bistatic reflectivity dependence on the moisture content and matric potential of bare soil
Waite, W. P.; Sadeghi, A. M.; Scott, H. D.
1984-01-01
Results are presented of an experimental program to determine the functional dependence of the microwave reflectivity of nonvegetated soil surfaces upon volumetric soil moisture and matric potential. A combination evaporation-drainage field experiment was conducted on a bare Captina slit loam with reflectivity, soil moisture content, and matric potential monitored for extended time periods. Results show that for a restricted pressure range (approximately -0.05 to -0.75 bar) there is excellent linear correlation between the log of bistatic reflectivity and both volumetric moisture content and matric potential. Layering effects due to steep moisture content (and matric potential) gradients in the profile are demonstrated to have two distinct and significant effects on the reflectivity response. At near saturation of rough surfaces a very thin dry surface layer appears to modify the effective roughness. This leads to a saturation of reflectivity at high moisture contents. As the surface proceeds to dry further, deeper layers produce coherent interference patterns in the reflectivity response, particularly at the higher frequencies.
New method for continuous determination of depth-dependent reflection coefficients of Rayleigh waves
International Nuclear Information System (INIS)
A new experimental method and principle were presented for the continuous measurement of the depth-dependant reflection coefficient of Rayleigh waves or their pulse interacting with various surface discontinuities. The method was to record the reflection-echo-amplitudes for varying depth during scanning the Rayleigh wave pulse with a small lateral beam width along a surface discontinuity with a small slope in depth. In the experiments using a declined slot and intensively focused Rayleigh waves, the coefficients were continuously measured with quite good reproducibility in the range of $0.05
International Nuclear Information System (INIS)
Interface perpendicular magnetic anisotropy (PMA) in ultrathin Fe/MgO (001) has been investigated using angular-dependent x-ray magnetic circular dichroism (XMCD). We found that anisotropic orbital magnetic moments deduced from the analysis of XMCD contribute to the large PMA energies, whose values depend on the annealing temperature. The large PMA energies determined from magnetization measurements are related to those estimated from the XMCD and the anisotropic orbital magnetic moments through the spin-orbit interaction. The enhancement of anisotropic orbital magnetic moments can be explained mainly by the hybridization between the Fe 3dz2 and O 2pz states.
Energy Technology Data Exchange (ETDEWEB)
Okabayashi, J. [Research Center for Spectrochemistry, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan); Koo, J. W.; Mitani, S. [National Institute for Materials Science (NIMS), Tsukuba 305-0047 (Japan); Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8577 (Japan); Sukegawa, H. [National Institute for Materials Science (NIMS), Tsukuba 305-0047 (Japan); Takagi, Y.; Yokoyama, T. [Institute of Molecular Science, Okazaki, Aichi 444-8585 (Japan)
2014-09-22
Interface perpendicular magnetic anisotropy (PMA) in ultrathin Fe/MgO (001) has been investigated using angular-dependent x-ray magnetic circular dichroism (XMCD). We found that anisotropic orbital magnetic moments deduced from the analysis of XMCD contribute to the large PMA energies, whose values depend on the annealing temperature. The large PMA energies determined from magnetization measurements are related to those estimated from the XMCD and the anisotropic orbital magnetic moments through the spin-orbit interaction. The enhancement of anisotropic orbital magnetic moments can be explained mainly by the hybridization between the Fe 3d{sub z}{sup 2} and O 2p{sub z} states.
Energy Technology Data Exchange (ETDEWEB)
Gibson, S T; Cavanagh, S J; Lewis, B R [Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Gascooke, J R [School of Chemistry, Physics and Earth Sciences, Flinders University, SA 5001 (Australia); Mabbs, R [Department of Chemistry, Washington University, St Louis MO 63930-4899 (United States); Sanov, A, E-mail: Stephen.Gibson@anu.edu.a, E-mail: Steven.Cavanagh@anu.edu.a [Department of Chemistry, University of Arizona, Tucson AZ 85721-0041 (United States)
2009-11-01
The photodetachment spectrum of O{sub 2}{sup -} has been measured at a number of wavelengths using velocity-map imaging. The electron kinetic-energy resolution (< 5 meV) is sufficient to resolve the anion fine-structure splitting, vibrational and electronic structure. The electron angular distribution varies with the electron kinetic-energy, with a different behaviour for each vibronic band.
Yamilov, A; Sarma, R; Cao, H
2015-01-01
The universal bimodal distribution of transmission eigenvalues in lossless diffusive systems un- derpins such celebrated phenomena as universal conductance fluctuations, quantum shot noise in condensed matter physics and enhanced transmission in optics and acoustics. Here, we show that in the presence of absorption, density of the transmission eigenvalues depends on the confinement geometry of scattering media. Furthermore, in an asymmetric waveguide, densities of the reflection and absorption eigenvalues also depend of the side from which the waves are incident. With increas- ing absorpotion, the density of absorption eigenvalues transforms from single-peak to double-peak function. Our findings open a new avenue for coherent control of wave transmission, reflection and absorption in random media.
Directory of Open Access Journals (Sweden)
TalDotanBen-Soussan
2014-02-01
Full Text Available Quadrato Motor Training (QMT is a specifically-structured walking meditation, aimed at improving reflectivity and lowering habitual thought and movement. Here we set out to examine the possible effect of QMT on reflectivity, employing the Hidden Figures Test (HFT, which assesses both spatial performance (measured by correct answers as well as reflectivity (interpolated from correct answers and reaction time. In the first study (n = 24, only females, we showed that QMT significantly improves HFT performance, compared to two groups, controlling for cognitive or motor aspects of the QMT: Verbal Training (identical cognitive training with verbal response and Simple Motor Training (similar motor training with reduced choice requirements. These results show that QMT improves HFT performance above the pre-post expected learning. In the second study, building on previous literature showing gender-dependent effects on cognitive performance, we conducted a preliminary pilot examining gender-dependent effect of training on reflectivity and its electrophysiological counterparts. EEG analyses focused on theta, alpha and gamma coherence. HFT performance and resting-state EEG were measured in 37 participants (20 males, using a within-subject pre-post design. Following training, HFT performance improved in both genders. However, we found a gender-dependent difference in functional connectivity: While theta and alpha intra-hemispheric coherence was enhanced in females, the opposite pattern was found in males. These results are discussed in relation to neuronal efficiency theory. Together, the results demonstrate that QMT improves spatial performance, and may involve a gender-dependent electrophysiological effect. This study emphasizes both the importance of studying gender-related training effects within the contemplative neuroscience endeavor, as well as the need to widen its scope towards including "contemplation in action".
Ben-Soussan, Tal Dotan; Berkovich-Ohana, Aviva; Glicksohn, Joseph; Goldstein, Abraham
2014-01-01
Quadrato Motor Training (QMT) is a specifically-structured walking meditation, aimed at improving reflectivity and lowering habitual thought and movement. Here we set out to examine the possible effect of QMT on reflectivity, employing the Hidden Figures Test (HFT), which assesses both spatial performance (measured by correct answers) as well as reflectivity (interpolated from correct answers and reaction time). In the first study (n = 24, only females), we showed that QMT significantly improves HFT performance, compared to two groups, controlling for cognitive or motor aspects of the QMT: Verbal Training (identical cognitive training with verbal response) and Simple Motor Training (similar motor training with reduced choice requirements). These results show that QMT improves HFT performance above the pre-post expected learning. In the second study, building on previous literature showing gender-dependent effects on cognitive performance, we conducted a preliminary pilot examining gender-dependent effect of training on reflectivity and its electrophysiological counterparts. EEG analyses focused on theta, alpha and gamma coherence. HFT performance and resting-state EEG were measured in 37 participants (20 males), using a within-subject pre-post design. Following training, HFT performance improved in both genders. However, we found a gender-dependent difference in functional connectivity: while theta and alpha intra-hemispheric coherence was enhanced in females, the opposite pattern was found in males. These results are discussed in relation to neuronal efficiency theory. Together, the results demonstrate that QMT improves spatial performance, and may involve a gender-dependent electrophysiological effect. This study emphasizes both the importance of studying gender-related training effects within the contemplative neuroscience endeavor, as well as the need to widen its scope toward including "contemplation in action." PMID:24550872
Time-dependent Bragg diffraction and short-pulse reflection by one-dimensional photonic crystals
André, Jean-michel
2015-01-01
The time-dependence of the Bragg diffraction by one-dimensional photonic crystals and its influence on the short pulse reflection are studied in the framework of the coupled- wave theory. The indicial response of the photonic crystal is calculated and it appears that it presents a time-delay effect with a transient time conditioned by the extinction length. A numerical simulation is presented for a Bragg mirror in the x-ray domain and a pulse envelope modelled by a sine-squared shape. The potential consequences of the time-delay effect in time-dependent optics of short-pulses are emphasized.
Absence of phase-dependent noise in time-domain reflectivity studies of impulsively excited phonons
Hussain, A.
2010-06-17
There have been several reports of phase-dependent noise in time-domain reflectivity studies of optical phonons excited by femtosecond laser pulses in semiconductors, semimetals, and superconductors. It was suggested that such behavior is associated with the creation of squeezed phonon states although there is no theoretical model that directly supports such a proposal. We have experimentally re-examined the studies of phonons in bismuth and gallium arsenide, and find no evidence of any phase-dependent noise signature associated with the phonons. We place an upper limit on any such noise at least 40–50 dB lower than previously reported.
Loiko, V. A.; Krakhalev, M. N.; Konkolovich, A. V.; Prishchepa, O. O.; Miskevich, A. A.; Zyryanov, V. Ya.
2016-07-01
Light scattering by a monolayer of bipolar nematic droplets encapsulated in polymer film is examined both experimentally and theoretically. A method for the simulation of the angular distribution of scattered light is based on the anomalous diffraction and interference approximations taking into account the director configuration within liquid crystal droplets and their bipolar axes orientation. The director configuration in nematic droplets is calculated using the relaxation method of the free energy minimization. The characteristics of the sample, including distribution of droplet sizes and shape anisometry, are measured in details. The experimental results and theoretical data agree closely with each other.
Soliton-dependent plasmon reflection at bilayer graphene domain walls.
Jiang, Lili; Shi, Zhiwen; Zeng, Bo; Wang, Sheng; Kang, Ji-Hun; Joshi, Trinity; Jin, Chenhao; Ju, Long; Kim, Jonghwan; Lyu, Tairu; Shen, Yuen-Ron; Crommie, Michael; Gao, Hong-Jun; Wang, Feng
2016-08-01
Layer-stacking domain walls in bilayer graphene are emerging as a fascinating one-dimensional system that features stacking solitons structurally and quantum valley Hall boundary states electronically. The interactions between electrons in the 2D graphene domains and the one-dimensional domain-wall solitons can lead to further new quantum phenomena. Domain-wall solitons of varied local structures exist along different crystallographic orientations, which can exhibit distinct electrical, mechanical and optical properties. Here we report soliton-dependent 2D graphene plasmon reflection at different 1D domain-wall solitons in bilayer graphene using near-field infrared nanoscopy. We observe various domain-wall structures in mechanically exfoliated graphene bilayers, including network-forming triangular lattices, individual straight or bent lines, and even closed circles. The near-field infrared contrast of domain-wall solitons arises from plasmon reflection at domain walls, and exhibits markedly different behaviours at the tensile- and shear-type domain-wall solitons. In addition, the plasmon reflection at domain walls exhibits a peculiar dependence on electrostatic gating. Our study demonstrates the unusual and tunable coupling between 2D graphene plasmons and domain-wall solitons. PMID:27240109
Energy Technology Data Exchange (ETDEWEB)
Singh, Braj Bhusan; Chaudhary, Sujeet, E-mail: sujeetc@physics.iitd.ac.in
2015-07-01
We report the investigation of the in-plane azimuthal angular dependence of the magnetization reversal in the ion beam sputtered exchanged biased NiFe(111)/FeMn(111)/CoFeB(amorphous) stack. Compared to the as-deposited case, the magnetic annealing resulted in 3 fold enhancement in exchange bias but decrease in coercivity. The observed cosine dependence of exchange biased CoFeB layer on the in-plane azimuthal angle of applied field is corroborated with Meiklejohn and Bean model. The training effect associated with the exchange bias showed unconventional increase in coercivity after first cycle of hysteresis loop, while the exchange bias decreases sharply, and for subsequent cycles the exchange bias follows the empirical relation based on the energy dissipation in the AF layer. The ferromagnetic resonance (FMR) measurements also exhibited the in-plane azimuthal angle dependence of the magnetic resonance field indicating that the uniaxial and unidirectional anisotropies are not collinear, although they lie in the same plane. However, no misalignment between the unidirectional anisotropy and the exchange bias direction is observed. The misalignment angle between the uniaxial and unidirectional anisotropy, as measured by FMR, is found to be 10° and 14° for CoFeB and NiFe, respectively. This misalignment is attributed to the interface roughness as revealed by x-ray reflectance measurements. - Highlights: • In-plane azimuthal angular dependence of the magnetization reversal in the ion beam sputtered exchanged biased NiFe(111)/FeMn(111)/ CoFeB(amorphous) stack. • The observed cosine dependence of exchange biased CoFeB layer on the in-plane azimuthal angle of applied field is corroborated with Meiklejohn and Bean model. • In-plane azimuthal angle dependence of the magnetic resonance field indicates that the uniaxial and unidirectional anisotropies are not collinear, although they lie in the same plane. • The misalignment angle between the uniaxial and
Duveiller, G.; Lopez-Lozano, R.
2013-12-01
Global agricultural monitoring requires satellite Earth Observation systems that maximize the observation revisit frequency over the largest possible geographical coverage. Such compromise has thus far resulted in using a spatial resolution that is often coarser than desired. As a consequence, for many agricultural landscapes across the world, crop status can only be inferred from a mixed signal of the landscape (with a pixel size typically close to 1 km), composed of reflectance from neighbouring fields with potentially different crops, variable phenological behaviours and distinct management practices. MODIS has been providing, since 2000, a higher spatial resolution (~250m) that is closer to the size of individual fields in many agro-ecological landscapes. However, the challenge for operational crop specific monitoring remains to identify in time where a given crop has been sown during the current growing season. An innovative use of MODIS daily data is proposed for crop identification based on the stability of the multi-angular signal. MODIS is a whiskbroom sensor with a large swath. For any given place, consecutive MODIS observations are made with considerably different viewing angles according to the daily change in orbit. Consequently, the footprint of the observation varies considerably, thereby sampling the vicinity around the centre of the grid cell in which the time series is ultimately recorded in. If the consecutive observations that have sampled the vicinity provide similar NDVI values (for which BRDF effects are reduced), the resulting temporal signal is relatively stable. This stability indicated that the signal comes from a spatially homogeneous surface, such as a single large field covered by the same crop with similar agro-management practices. If the resulting temporal signal is noisy, it is probable that the consecutive daily observations have sampled different land uses, thus contaminating the signal. Such time series can therefore be
Rahmanseresht, Sheema; Gamari, Ben D; Goldner, Lori S
2014-01-01
We report on the observation of a change in the bend angle of an RNA kissing complex upon Rop binding using single-molecular-pair FRET. The angular relationship between the dyes, rather than the distance between them, is shown to be responsible for the observed change in energy transfer. It has long been thought that Rop increases the bend angle of the R1inv-R2inv complex upon binding, but this has never been directly observed. In contrast, we find an increase in FRET upon the addition of Rop that is shown via modeling to be consistent with a decrease in the bend angle of the complex of $-15^{\\circ}\\pm7^{\\circ}$. The model predicts FRET from dye trajectories generated using molecular dynamics simulations of Cy3 and Cy5 attached to $5'$ terminal cytosine or guanosine on RNA. While FRET is commonly used to observe global changes in molecular structure attributed to changes in the distance between dyes, it is rarely, if ever, used to elucidate angular changes. Subtle global changes in molecular structure upon bi...
Polarization dependent diffraction anomalous fine structure of rutile TiO2 001 and 111 reflections
International Nuclear Information System (INIS)
Energy and polarization dependent Diffraction Anomalous Fine Structure (DAFS) also known as Anisotropic Anomalous Scattering (AAS) can be employed in addition to X-ray Absorption Fine Structure (XAFS) to study electronic transitions from core states to unoccupied states. Here, we present results from resonant X-ray diffraction experiments on TiO2 rutile, space group (136) P42/mnm. For this model structure, site symmetry information was extracted from determination of the structure factor tensor by refining elements of Ti atomic scattering factor tensors. Influences of oxygen vacancies on the anomalous scattering contributions have been studied on a series of rutile wafers of different oxygen concentration. Samples investigated were 10 x 10 x 1 mm3 single crystal wafers and experiments were carried out at DESY/HASYLAB beamlines C and E2 using a Si(111) double crystal monochromator in the vicinity of the Ti-K absorption edge. Considered reflections include the 'forbidden' 001 and allowed 111 reflection.
Zhang, Jingchuan; Lörscher, Christopher; Gu, Qiang; Klemm, Richard A.
2014-01-01
We calculate the temperature $T$ and angular $(\\theta,\\phi)$ dependence of the upper critical induction $B_{c2}(\\theta,\\phi,T)$ for parallel-spin superconductors with an axially symmetric $p$-wave pairing interaction pinned to the lattice and a dominant ellipsoidal Fermi surface (FS). For all FS anisotropies, the chiral Scharnberg-Klemm state $B_{c2}(\\theta,\\phi,T)$ exceeds that of the chiral Anderson-Brinkman-Morel state, and exhibits a kink at $\\theta=\\theta^{*}(T,\\phi)$, indicative of a fi...
International Nuclear Information System (INIS)
Full text: The determination of the CP-violating phase in Bs0→JΨΦ decays is one of the key goals of the LHCb experiment. Its value is predicted to be very small in the Standard Model but can be significantly enhanced in many models of New Physics. The steps towards a precise determination of this phase with a flavour-tagged, time-dependent, angular analysis of the decay Bs0→JΨΦ will be reviewed and first studies performed with data collected at LHC in pp collisions at 7 TeV center-of-mass energy will be presented. (author)
Angular dependence of the upper critical field in Bi sub 2 Sr sub 2 CuO sub 6 sub + subdelta
Vedeneev, S I
2002-01-01
The angular dependence of the upper critical field has been investigated in a wide range of temperatures in very high-quality Bi sub 2 Sr sub 2 CuO sub 6 sub + subdelta single crystals with critical temperature approx = 9 K in magnetic fields up to 28 T. Although the typical value of the normal state resistivity ratio approx = 10 sup 4 , the anisotropy ratio of the upper critical fields is much smaller. A model is proposed based on a strong anisotropy and a small transparency between superconducting layers
... A This image displays a frequent location for candida infection (angular cheilitis), the corners of the mouth. Overview ... infection, those affected may also have thrush (oral candidiasis). The areas are generally slightly painful. The condition ...
International Nuclear Information System (INIS)
Purpose: To evaluate the angular dependence correction for Matrix Evolution 2D array detector in quality assurance of volumetric modulated arc therapy(VMAT). Methods: Total ten patients comprising of different sites were planned for VMAT and taken for the study. Each plan was exposed on Matrix Evolution 2D array detector with Omnipro IMRT software based on the following three different methods using 6MV photon beams from Elekta Synergy linear accelerator. First method, VMAT plan was delivered on Matrix Evolution detector as it gantry mounted with dedicated holder with build-up of 2.3cm. Second, the VMAT plan was delivered with the static gantry angle on to the table mounted setup. Third, the VMAT plan was delivered with actual gantry angle on Matrix Evolution detector fixed in Multicube phantom with gantry angle sensor and angular dependence correction were applied to quantify the plan quality. For all these methods, the corresponding QA plans were generated in TPS and the dose verification was done for both point and 2D fluence analysis with pass criteria of 3% dose difference and 3mm distance to agreement. Results: The measured point dose variation for the first method was observed as 1.58±0.6% of mean and SD with TPS calculated. For second and third method, the mean and standard deviation(SD) was observed as 1.67±0.7% and 1.85±0.8% respectively. The 2D fluence analysis of measured and TPS calculated has the mean and SD of 97.9±1.1%, 97.88±1.2% and 97.55±1.3% for first, second and third methods respectively. The calculated two-tailed Pvalue for point dose and 2D fluence analysis shows the insignificance with values of 0.9316 and 0.9015 respectively, among the different methods of QA. Conclusion: The qualitative evaluation of angular dependence correction for Matrix Evolution 2D array detector shows its competency in accuracy of quality assurance measurement of composite dose distribution of volumetric modulated arc therapy
Dmitrašinović, V
2015-01-01
We present results of numerical calculations showing a three-body orbit's period's $T$ dependence on its topology. This dependence is a simple linear one, when expressed in terms of appropriate variables, suggesting an exact mathematical law. This is the first known relation between topological and kinematical properties of three-body systems. We have used these results to predict the periods of several sets of as yet undiscovered orbits, but the relation also indicates that the number of periodic three-body orbits with periods shorter than any finite number is countable.
DEFF Research Database (Denmark)
Rasmussen, Mads Olander; Pinheiro, AC; Proud, Simon Richard;
2010-01-01
Satellite-based estimates of land surface temperature (LST) are widely applied as an input to models. A model output is often very sensitive to error in the input data, and high-quality inputs are therefore essential. One of the main sources of errors in LST estimates is the dependence on vegetat...
International Nuclear Information System (INIS)
We calculate the temperature T and angular (θ, ϕ) dependencies of the upper critical induction Bc2(θ, ϕ, T) for parallel-spin superconductors with an axially symmetric p-wave pairing interaction pinned to the lattice and a dominant ellipsoidal Fermi surface (FS). For all FS anisotropies, the chiral Scharnberg–Klemm (SK) state Bc2(θ, ϕ, T) exceeds that of the chiral Anderson–Brinkman–Morel (ABM) state and exhibits a kink at θ = θ*(T, ϕ), indicative of a first-order transition from its chiral, nodal-direction behavior to its non-chiral, antinodal-direction behavior. Applicabilities to Sr2RuO4, UCoGe and the candidate topological superconductor CuxBi2Se3 are discussed. (fast track communication)
Okabayashi, Jun; Sukegawa, Hiroaki; Wen, Zhenchao; Inomata, Koichiro; Mitani, Seiji
2013-09-01
Perpendicular magnetic anisotropy (PMA) in Heusler alloy Co2FeAl thin films sharing an interface with a MgO layer is investigated by angular-dependent x-ray magnetic circular dichroism. Orbital and spin magnetic moments are deduced separately for Fe and Co 3d electrons. In addition, the PMA energies are estimated using the orbital magnetic moments parallel and perpendicular to the film surfaces. We found that PMA in Co2FeAl is determined mainly by the contribution of Fe atoms with large orbital magnetic moments, which are enhanced at the interface between Co2FeAl and MgO. Furthermore, element specific magnetization curves of Fe and Co are found to be similar, suggesting the existence of ferromagnetic coupling between Fe and Co PMA directions.
International Nuclear Information System (INIS)
The angular dependences of proton photoproduction on the C12, Cu63 and Pb208 nuclei by bremsstrahlung γ-quanta with the maximum energy 4.5 GeV both in cumulattive region (i.e. in kinematical region in which the production of protons at collision of γ-quanta of the given energy with the quasi-free nuclear nucleon is forbidden) and in non-cumulative region are investigated. Invariant cross sections on the photonuclear reactions are presented. The obtained experimental data are compared with the results of theoretical calculations of cumulative proton photoproduction according to the following models: quasi-two-body scaling model, low-nucleon correlation model fluctuon model and cluster model. The best agreement has been obtained for the cluster model
Energy Technology Data Exchange (ETDEWEB)
Bellei, C.; Divol, L.; Kemp, A. J.; Key, M. H.; Larson, D. J.; Strozzi, D. J.; Marinak, M. M.; Tabak, M.; Patel, P. K. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States)
2013-05-15
The energy and angular distributions of the fast electrons predicted by particle-in-cell (PIC) simulations differ from those historically assumed in ignition designs of the fast ignition scheme. Using a particular 3D PIC calculation, we show how the ignition energy varies as a function of source-fuel distance, source size, and density of the pre-compressed fuel. The large divergence of the electron beam implies that the ignition energy scales with density more weakly than the ρ{sup −2} scaling for an idealized beam [S. Atzeni, Phys. Plasmas 6, 3316 (1999)], for any realistic source that is at some distance from the dense deuterium-tritium fuel. Due to the strong dependence of ignition energy with source-fuel distance, the use of magnetic or electric fields seems essential for the purpose of decreasing the ignition energy.
Vasques, Richard
2013-01-01
We describe an analysis of neutron transport in the interior of model pebble bed reactor (PBR) cores, considering both crystal and random pebble arrangements. Monte Carlo codes were developed for (i) generating random realizations of the model PBR core, and (ii) performing neutron transport inside the crystal and random heterogeneous cores; numerical results are presented for two different choices of material parameters. These numerical results are used to investigate the anisotropic behavior of neutrons in each case and to assess the accuracy of estimates for the diffusion coefficients obtained with the diffusion approximations of different models: the atomic mix model, the Behrens correction, the Lieberoth correction, the generalized linear Boltzmann equation (GLBE), and the new GLBE with angular-dependent path-length distributions. This new theory utilizes a non-classical form of the Boltzmann equation in which the locations of the scattering centers in the system are correlated and the distance-to-collisi...
On the relation between angular momentum and angular velocity
Silva, J. P.; Tavares, J. M.
2007-01-01
Students of mechanics usually have difficulties when they learn about the rotation of a rigid body. These difficulties are rooted in the relation between angular momentum and angular velocity, because these vectors are not parallel, and we need in general to utilize a rotating frame of reference or a time dependent inertia tensor. We discuss a series of problems that introduce both difficulties.
DEFF Research Database (Denmark)
Sing, M; Meyer, J; Hoinkis, M; Glawion, S; Blaha, P; Gavrila, G; Jacobsen, Claus Schelde; Claessen, R
2007-01-01
We have performed angle-dependent near-edge x-ray absorption fine structure measurements in the Auger electron yield mode on the correlated quasi-one-dimensional organic conductor tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) in order to determine the orientation of the molecules in the...... the one-dimensional Hubbard model. Thereby, recent theoretical results are corroborated which invoke long-range Coulomb repulsion as alternative explanation to understand the spectral dispersions of TTF-TCNQ quantitatively within an extended Hubbard model....
International Nuclear Information System (INIS)
The dynamics of the O(1D) + Xe electronic quenching reaction was investigated in a crossed beam experiment at four collision energies. Marked large-scale oscillations in the differential cross sections were observed for the inelastic scattering products, O(3P) and Xe. The shape and relative phases of the oscillatory structure depend strongly on collision energy. Comparison of the experimental results with time-independent scattering calculations shows qualitatively that this behavior is caused by Stueckelberg interferences, for which the quantum phases of the multiple reaction pathways accessible during electronic quenching constructively and destructively interfere
International Nuclear Information System (INIS)
We investigate the excitation energy (E*) and angular momentum (J) dependence of nuclear level density and spin cut-off factor (σ) within microscopic approaches based on SPA and its extension SPA+RPA representation of the grand partition function for quadrupole-quadrupole interaction model Hamiltonian. For 110Sn, we find that excitation energy dependence of the total level density obtained within these approaches is significantly different. On the other hand, these approaches yield similar behaviour for J-dependence of the level density at fixed values of E*. Values of σSPA+RPA at low E* are found to be slightly smaller than σSPA but they tend to become almost the same at higher E* (>30 MeV). We also find that Bethe's formula for fixed-J level density based on the spin cut-off approximation can be used to compute ρ(E*,J) near the yrast line provided one uses an appropriate value of the spin cut-off factor. (orig.)
International Nuclear Information System (INIS)
We have performed angle-dependent near-edge x-ray absorption fine structure measurements in the Auger electron yield mode on the correlated quasi-one-dimensional organic conductor tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) in order to determine the orientation of the molecules in the topmost surface layer. We find that the tilt angles of the molecules with respect to the one-dimensional axis are essentially the same as in the bulk. Thus, we can rule out surface relaxation as the origin of the renormalized band widths which were inferred from the analysis of photoemission data within the one-dimensional Hubbard model. Thereby, recent theoretical results are corroborated which invoke long-range Coulomb repulsion as alternative explanation to understand the spectral dispersions of TTF-TCNQ quantitatively within an extended Hubbard model
International Nuclear Information System (INIS)
Purpose: The quantification of the relative surface dose enhancement in dependence on the angle of incidence and the atomic number Z of the surface material. Methods: Experiments were performed with slabs made of aluminum, titanium, copper, silver, dental gold and lead. The metal slabs with equal sizes of 1.0×8.0×8.8mm3 were embedded in an Octavius 4D phantom (PTW Freiburg, Germany). Radiochromic EBT3 films were used to measure the surface dose for angles of incidence ranging from 0° to 90°. The setup with the metals slabs at the isocenter was irradiated with acceleration voltages of 6MV and 10MV. Water reference measurements were taken under equal conditions. Results: The surface dose enhancement is highest for angles of incidence below 30° and drops significantly for higher. The surface dose enhancement produced by lead and dental gold at 6MV showed a peak of 65%. At 90°, the surface dose enhancement dropped to 15% for both materials. The surface dose enhancements for silver, copper, titanium and aluminum were 45%, 32%, 22% and 12% at 0°, respectively. At an angle of incidence of 80°, the values dropped to 22%, 18%, 12% und 6%. The values for 10MV were very similar. Lead and dental gold showed peaks of 65% und 60%. Their values dropped to 18% at an angle of 90°. The surface dose enhancements for silver, copper, titanium and aluminum were 45%, 30%, 20% and 8% at 0°. At 80° the values dropped to 30%, 20%, 12% and 5%. A dependence of the magnitude of the surface dose enhancement on the atomic number of the surface material can be seen, which is in consistence with literature. Conclusion: The results show that the surface dose enhancements near implant materials with high Z-values should be taken into consideration in radio therapy, even when the angle of incidence is flat
Energy Technology Data Exchange (ETDEWEB)
Jansen, A; Schoenfeld, A; Poppinga, D; Chofor, N; Poppe, B [University of Oldenburg, Oldenburg (Germany); Pius Hospital Oldenburg, Oldenburg (Germany)
2014-06-01
Purpose: The quantification of the relative surface dose enhancement in dependence on the angle of incidence and the atomic number Z of the surface material. Methods: Experiments were performed with slabs made of aluminum, titanium, copper, silver, dental gold and lead. The metal slabs with equal sizes of 1.0×8.0×8.8mm{sup 3} were embedded in an Octavius 4D phantom (PTW Freiburg, Germany). Radiochromic EBT3 films were used to measure the surface dose for angles of incidence ranging from 0° to 90°. The setup with the metals slabs at the isocenter was irradiated with acceleration voltages of 6MV and 10MV. Water reference measurements were taken under equal conditions. Results: The surface dose enhancement is highest for angles of incidence below 30° and drops significantly for higher. The surface dose enhancement produced by lead and dental gold at 6MV showed a peak of 65%. At 90°, the surface dose enhancement dropped to 15% for both materials. The surface dose enhancements for silver, copper, titanium and aluminum were 45%, 32%, 22% and 12% at 0°, respectively. At an angle of incidence of 80°, the values dropped to 22%, 18%, 12% und 6%. The values for 10MV were very similar. Lead and dental gold showed peaks of 65% und 60%. Their values dropped to 18% at an angle of 90°. The surface dose enhancements for silver, copper, titanium and aluminum were 45%, 30%, 20% and 8% at 0°. At 80° the values dropped to 30%, 20%, 12% and 5%. A dependence of the magnitude of the surface dose enhancement on the atomic number of the surface material can be seen, which is in consistence with literature. Conclusion: The results show that the surface dose enhancements near implant materials with high Z-values should be taken into consideration in radio therapy, even when the angle of incidence is flat.
Energy Technology Data Exchange (ETDEWEB)
Edmonds, Ian [Solartran Pty Ltd., 12 Lentara St, Kenmore, Brisbane 4069 (Australia); Smith, Geoff [Physics and Advanced Materials, University of Technology, Sydney, PO Box 123, Broadway, New South Wales 2007 (Australia)
2011-05-15
A means of assessing the relative impact of different renewable energy technologies on global warming has been developed. All power plants emit thermal energy to the atmosphere. Fossil fuel power plants also emit CO{sub 2} which accumulates in the atmosphere and provides an indirect increase in global warming via the greenhouse effect. A fossil fuel power plant may operate for some time before the global warming due to its CO{sub 2} emission exceeds the warming due to its direct heat emission. When a renewable energy power plant is deployed instead of a fossil fuel power plant there may be a significant time delay before the direct global warming effect is less than the combined direct and indirect global warming effect from an equivalent output coal fired plant - the ''business as usual'' case. Simple expressions are derived to calculate global temperature change as a function of ground reflectance and conversion efficiency for various types of fossil fuelled and renewable energy power plants. These expressions are used to assess the global warming mitigation potential of some proposed Australian renewable energy projects. The application of the expressions is extended to evaluate the deployment in Australia of current and new geo-engineering and carbon sequestration solutions to mitigate global warming. Principal findings are that warming mitigation depends strongly on the solar to electric conversion efficiency of renewable technologies, geo-engineering projects may offer more economic mitigation than renewable energy projects and the mitigation potential of reforestation projects depends strongly on the location of the projects. (author)
LHCb: Tagged time-dependent angular analysis of $B^0_s \\to J/\\psi K^+ K^-$ at LHCb
Syropoulos, V
2013-01-01
The time-dependent CP-violating asymmetry in $B^0_s\\to J/\\psi K^{+}K^{-}$ decays is measured using $1.0^{-1}$ of $pp$ of collisions at $\\sqrt{s}=7$ TeV collected with the LHCb detector. The decay time distribution of $B^0_s\\to J/\\psi K^{+}K^{-}$ is characterized by the decay widths $\\Gamma_{\\mathrm{H}}$ and $\\Gamma_{\\mathrm{L}}$ of the heavy and light mass eigenstates of the $B^0_s - \\bar{B^0_s}$ system and by a CP-violating phase $\\phi_s$. In a sample of approximately 27600 $B^0_s\\to J/\\psi K^{+}K^{-}$ events we measure $\\phi_s \\: = \\: 0.068 \\: \\pm \\: 0.091 \\: \\text{(stat)} \\: \\pm \\: 0.011 \\: \\text{(syst)} \\: \\text{rad}$. We also find an average $B^0_s$ decay width $\\Gamma_s \\equiv (\\Gamma_{\\mathrm{L}}+\\Gamma_{\\mathrm{H}})/2 \\: = \\: 0.671 \\: \\pm \\: 0.005 \\: \\text{(stat)} \\: \\pm \\: 0.006 \\: \\text{(syst)} \\: ps^{-1}$ and a decay width difference $\\Delta \\Gamma_s \\equiv \\Gamma_{\\mathrm{L}} - \\Gamma_{\\mathrm{H}} \\: = \\: 0.100 \\: \\pm \\: 0.016 \\: \\text{(stat)} \\: \\pm \\: 0.003 \\: \\text{(syst)} \\: ps^...
Achromatic orbital angular momentum generator
Bouchard, Frédéric; Mand, Harjaspreet; Mirhosseini, Mohammad; Karimi, Ebrahim; Boyd, Robert W
2014-01-01
We describe a novel approach for generating light beams that carry orbital angular momentum (OAM) by means of total internal reflection in an isotropic medium. A continuous space-varying cylindrically symmetric reflector, in the form of \\textit{two glued hollow axicons}, is used to introduce a nonuniform rotation of polarisation into a linearly polarised input beam. This device acts as a full spin-to-orbital angular momentum convertor. It functions by switching the helicity of the incoming be...
Ben-Soussan, Tal Dotan; Berkovich-Ohana, Aviva; Glicksohn, Joseph; Goldstein, Abraham
2014-01-01
Quadrato Motor Training (QMT) is a specifically-structured walking meditation, aimed at improving reflectivity and lowering habitual thought and movement. Here we set out to examine the possible effect of QMT on reflectivity, employing the Hidden Figures Test (HFT), which assesses both spatial performance (measured by correct answers) as well as reflectivity (interpolated from correct answers and reaction time). In the first study (n = 24, only females), we showed that QMT significantly impro...
Energy Technology Data Exchange (ETDEWEB)
T' Jampens, Stephane; /Orsay
2006-09-18
This thesis presents the full-angular time-dependent analysis of the vector-vector channel B{sub d}{sup 0} {yields} J/{psi}(K{sub S}{sup 0}{pi}{sup 0})*{sup 0}. After a review of the CP violation in the B meson system, the phenomenology of the charmonium-K*(892) channels is exposed. The method for the measurement of the transversity amplitudes of the B {yields} J/{psi}K*(892), based on a pseudo-likelihood method, is then exposed. The results from a 81.9 fb{sup -1} of collected data by the BABAR detector at the {Upsilon}(4S) resonance peak are |A{sub 0}|{sup 2} = 0.565 {+-} 0.011 {+-} 0.004, |A{sub {parallel}}|{sup 2} = 0.206 {+-} 0.016 {+-} 0.007, |A{sub {perpendicular}}|{sup 2} = 0.228 {+-} 0.016 {+-} 0.007, {delta}{sub {parallel}} = -2.766 {+-} 0.105 {+-} 0.040 and {delta}{sub {perpendicular}} = 2.935 {+-} 0.067 {+-} 0.040. Note that ({delta}{sub {parallel}}, {delta}{sub {perpendicular}}) {yields} (-{delta}{sub {parallel}}, {pi} - {delta}{sub {perpendicular}}) is also a solution. The strong phases {delta}{sub {parallel}} and {delta}{sub {perpendicular}} are at {approx}> 3{sigma} from {+-}{pi}, signing the presence of final state interactions and the breakdown of the factorization hypothesis. The forward-backward analysis of the K{pi} mass spectrum revealed the presence of a coherent S-wave interfering with the K*(892). It is the first evidence of this wave in the K{pi} system coming from a B meson. The particularity of the B{sub d}{sup 0} {yields} J/{psi}(K{sub S}{sup 0}{pi}{sup 0})*{sup 0} channel is to have a time-dependent but also an angular distribution which allows to measure sin 2{beta} but also cos2{beta}. The results from an unbinned maximum likelihood fit are sin 2{beta} = -0.10 {+-} 0.57 {+-} 0.14 and cos 2{beta} = 3.32{sub -0.96}{sup +0.76} {+-} 0.27 with the transversity amplitudes fixed to the values given above. The other solution for the strong phases flips the sign of cos 2{beta}. Theoretical considerations based on the s-quark helicity
Simultaneous reflection masking: dependency on direct sound level and hearing-impairment
DEFF Research Database (Denmark)
Buchholz, Jörg; Mihai, Paul Glad
2008-01-01
Simultaneous reflection masked thresholds (RMTs) were measured for 3 normal-hearing (NH) and 3 hearing-impaired (HI) subjects as a function of reflection delay. All stimuli were presented diotically and dichotically, using a 200 ms long broadband noise (100-50000 Hz) as input signal. For 55 dB-SL...
Aubert, B; Boutigny, D; Couderc, F; Gaillard, J M; Hicheur, A; Karyotakis, Yu; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Shelkov, V G; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Foulkes, S D; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Lockman, W S; Nesom, G; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, Klaus R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Patteri, P; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, Erwin; Gamet, R; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Harrison, P F; Mohanty, G B; Cowan, G; Flack, R L; Flächer, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Fabozzi, F; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; LoSecco, J M; Gabriel, T A; Allmendinger, T; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; La Vaissière, C de; Del Buono, L; Hamon, O; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Anulli, F; Biasini, M; Peruzzi, I M; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martínez-Vidal, F; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai-Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B J; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel de Monchenault, G; Kozanecki, Witold; Langer, M; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, Gallieno; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Vavra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, Patricia R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R V; Roney, J M; Sobie, R J; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihályi, A; Mohapatra, A K; Pan, Y; Prepost, R; Rubin, A E; Sekula, S J; Tan, P; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H
2004-01-01
We present results on $B\\to J/\\psi\\xspace K\\pi$ decays using $e^+e^-$ annihilation data collected with the BABAR detector at the $\\Upsilon(4S)$ resonance. The detector is located at the PEP-II asymmetric-energy storage ring facility at the Stanford Linear Accelerator Center. Using approximately 88 million $B\\bar{B}$ pairs, we measure the decay amplitudes for the flavor eigenmodes and observe strong-phase differences indicative of final-state interactions with a significance of 7.6 standard deviations. We use the interference between the $K\\pi$ $S$-wave and $P$-wave amplitudes in the region of the $K^*(892)$ to resolve the ambiguity in the determination of these strong phases. We then perform an ambiguity-free measurement of $\\cos2\\beta$ using the angular and time-dependent asymmetry in $B\\to J/\\psi\\xspace K^{*0}(K_S^0\\pi^0$) dec With $\\sin 2 \\beta$ fixed at its measured value and $\\cos 2 \\beta$ treated as an in we find $\\cos 2\\beta=2.72_{-0.79}^{+0.50}\\mathrm{(stat)} \\pm 0.27\\mathrm{(syst)}$, de sign of $\\cos...
Klimov, Vasily V; Ducloy, Martial; Leite, Jose Roberto Rios
2012-01-01
We show that propagating optical fields bearing an axial symmetry are not truly hollow in spite of a null electric field on-axis. The result, obtained by general arguments based upon the vectorial nature of electromagnetic fields, is of particular significance in the situation of an extreme focusing, when the paraxial approximation no longer holds. The rapid spatial variations of fields with a "complicated" spatial structure are extensively analyzed in the general case and for a Laguerre-Gauss beam 2 as well, notably for beams bearing a |l| = 2 orbital angular momentum for which a magnetic field and a gradient of the electric field are present on-axis. We thus analyze the behavior of a atomic size light-detector, sensitive as well to quadrupole electric transitions and to magnetic dipole transitions, and apply it to the case of Laguerre-Gauss beam. We detail how the mapping of such a beam depends on the nature and on the specific orientation of the detector. We show also that the interplay of mixing of polari...
Fine structural dependence of ultraviolet reflections in the King Penguin beak horn.
Dresp, Birgitta; Langley, Keith
2006-03-01
The visual perception of many birds extends into the near-ultraviolet (UV) spectrum and ultraviolet is used by some to communicate. The beak horn of the King Penguin (Aptenodytes patagonicus) intensely reflects in the ultraviolet and this appears to be implicated in partner choice. In a preliminary study, we recently demonstrated that this ultraviolet reflectance has a structural basis, resulting from crystal-like photonic structures, capable of reflecting in the near-UV. The present study attempted to define the origin of the photonic elements that produce the UV reflectance and to better understand how the UV signal is optimized by their fine structure. Using light and electron microscopic analysis combined with new spectrophotometric data, we describe here in detail the fine structure of the entire King Penguin beak horn in addition to that of its photonic crystals. The data obtained reveal a one-dimensional structural periodicity within this tissue and demonstrate a direct relationship between its fine structure and its function. In addition, they suggest how the photonic structures are produced and how they are stabilized. The measured lattice dimensions of the photonic crystals, together with morphological data on its composition, permit predictions of the wavelength of reflected light. These correlate well with experimentally observed values. The way the UV signal is optimized by the fine structure of the beak tissue is discussed with regard to its putative biological role. PMID:16470837
Angular momentum in subbarrier fusion
International Nuclear Information System (INIS)
We have measured the ratio of the isomer to ground-state yields of 137Ce produced in the fusion reactions 128Te(12C,3n), 133Cs(7Li,3n), 136Ba(3He,2n), 136Ba(4He,3n), and 137Ba(3He,3n), from energies above the Coulomb barrier to energies typically 20--30% below the barrier by observing the delayed x- and γ-ray emission. We deduce the average angular momentum, , from the measured isomer ratios with a statistical model. In the first three reactions we observe that the values of exhibit the behavior predicted for low energies and the expected variation with the reduced mass of the entrance channel. We analyze these data and the associated cross sections with a barrier penetration model that includes the coupling of inelastic channels. Measurements of average angular momenta and cross sections made on other systems using the γ-multiplicity and fission-fragment angular correlation techniques are then analyzed in a similar way with this model. The discrepancies with theory for the γ-multiplicity data show correlations in cross section and angular momentum that suggest a valid model can be found. The measurements of angular momentum using the fission fragment angular correlation technique, however, do not appear reconcilable with the energy dependence of the cross sections. This systematic overview suggests, in particular, that our current understanding of the relationship of angular momentum and anisotropy in fission fragment angular correlations is incomplete. 26 refs
DEFF Research Database (Denmark)
Kristensen, Morten Pilgaard; Rector, D M; Poe, G R;
1996-01-01
Activity within the cat paraventricular hypothalamus (PVH) during sleep and waking states was measured by quantifying intrinsic tissue reflectivity. A fiber optic probe consisting of a 1.0 mm coherent image conduit, surrounded by plastic fibers which conducted 660 nm source light, was attached...... to a charge-coupled device camera, and positioned over the PVH in five cats. Electrodes for assessing state variables, including electroencephalographic activity, eye movement, and somatic muscle tone were also placed. After surgical recovery, reflected light intensity was measured continuously at 2.5 Hz...
Achromatic orbital angular momentum generator
Bouchard, Frédéric; Mirhosseini, Mohammad; Karimi, Ebrahim; Boyd, Robert W
2014-01-01
We describe a novel approach for generating light beams that carry orbital angular momentum (OAM) by means of total internal reflection in an isotropic medium. A continuous space-varying cylindrically symmetric reflector, in the form of \\textit{two glued hollow axicons}, is used to introduce a nonuniform rotation of polarisation into a linearly polarised input beam. This device acts as a full spin-to-orbital angular momentum convertor. It functions by switching the helicity of the incoming beam's polarisation, and by conservation of total angular momentum thereby generates a well-defined value of OAM. Our device is broadband, since the phase shift due to total internal reflection is nearly independent of wavelength. We verify the broad-band behaviour by measuring the conversion efficiency of the device for three different wavelengths corresponding to the RGB colours, red, green and blue. An average conversion efficiency of $95\\%$ for these three different wavelengths is observed. %, which confirms its wavelen...
Orbital angular momentum induced beam shifts
Hermosa N.; Merano M.; Aiello A.; Woerdman J.P.
2011-01-01
We present experiments on Orbital Angular Momentum (OAM) induced beam shifts in optical reflection. Specifically, we observe the spatial Goos-H\\"anchen shift in which the beam is displaced parallel to the plane of incidence and the angular Imbert-Fedorov shift which is a transverse angular deviation from the geometric optics prediction. Experimental results agree well with our theoretical predictions. Both beam shifts increase with the OAM of the beam; we have measured these for OAM indices u...
A selective reflecting film with a temperature-dependent pitch length
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
A(polymer network/liquid crystal/chiral dopants) composite exhibiting a temperature-sensing switch of infrared spectrum has been developed.Because of the different change of the chiral dopant in the helical twisting power and the anchoring effect of the polymer network,the polymer stabilized liquid crystal(PSLC) films,of which the bandwidth of the selective reflection spectra increased with changing temperature,were obtained.
International Nuclear Information System (INIS)
A CdTe solid-state detector was applied to the measurement of polarization-dependent total-reflection fluorescence XAFS spectra. The data revealed that the detector has good sensitivity, and this, together with its compact size, make it appropriate for in-situ measurements and removal of X-ray Bragg diffraction. The detector efficiently recorded the high-energy K-edge XAFS spectra for molybdenum oxides supported on TiO2 (110). (au) 10 refs
Energy Technology Data Exchange (ETDEWEB)
Pompeo, N., E-mail: pompeo@fis.uniroma3.it [Dipartimento di Fisica ' E. Amaldi' and Unita CNISM, Universita Roma Tre, Via della Vasca Navale 84, 00146 Roma (Italy); Rogai, R.; Torokhtii, K. [Dipartimento di Fisica ' E. Amaldi' and Unita CNISM, Universita Roma Tre, Via della Vasca Navale 84, 00146 Roma (Italy); Augieri, A.; Celentano, G.; Galluzzi, V. [ENEA-Frascati, Via Enrico Fermi 45, 00044 Frascati, Roma (Italy); Silva, E. [Dipartimento di Fisica ' E. Amaldi' and Unita CNISM, Universita Roma Tre, Via della Vasca Navale 84, 00146 Roma (Italy)
2012-09-15
We present a microwave study of the angular dependence of the flux-flow resistivity {rho}{sub ff} and of the pinning constant k{sub p} in YBCO thin films containing BZO nanorods. We find that BZO nanorods are very efficient pinning centers, even in tilted fields. We find that {rho}{sub ff} is a scaling function of a reduced field H/f({theta}). We extend a model for the anisotropic motion of vortices in uniaxially anisotropic superconductor, able to describe the experimental f({theta}) on the basis of only the intrinsic anisotropy of YBCO. The pinning constant k{sub p}, by contrast, exhibits different field dependences in different angular ranges, consistent with pinning by BZO at angles as large as 60 Degree-Sign , and with pinning along the a,b planes as originating from the same mechanism as in pure YBCO with the field along the c axis.
International Nuclear Information System (INIS)
We present a microwave study of the angular dependence of the flux-flow resistivity ρff and of the pinning constant kp in YBCO thin films containing BZO nanorods. We find that BZO nanorods are very efficient pinning centers, even in tilted fields. We find that ρff is a scaling function of a reduced field H/f(θ). We extend a model for the anisotropic motion of vortices in uniaxially anisotropic superconductor, able to describe the experimental f(θ) on the basis of only the intrinsic anisotropy of YBCO. The pinning constant kp, by contrast, exhibits different field dependences in different angular ranges, consistent with pinning by BZO at angles as large as 60°, and with pinning along the a,b planes as originating from the same mechanism as in pure YBCO with the field along the c axis.
Angular momentum projected semiclassics
Hasse, Rainer W.
1987-06-01
By using angular momentum projected plane waves as wave functions, we derive semiclassical expressions for the single-particle propagator, the partition function, the nonlocal density matrix, the single-particle density and the one particle-one hole level density for fixed angular momentum and fixed z-component or summed over the z-components. Other quantities can be deduced from the propagator. In coordinate space ( r, r') the relevant quantities depend on |r-r'| instead of | r- r'| and in Wigner space ( R, P) they become proportional to the angular momentum constraints δ(| R × P|/ h̵-l) and δ( R × P) z/ h̵-m) . As applications we calculate the single-particle and one-particle-one hole level densities for harmonic oscillator and Hill-Wheeler box potentials and the imaginary part of the optical potential and its volume integral with an underlying harmonic oscillator potential and a zero range two-body interaction.
International Nuclear Information System (INIS)
Rous sarcoma virus (RSV) requires incomplete splicing of its viral transcripts to maintain efficient replication. A splicing inhibitor element, the negative regulator of splicing (NRS), is located near the 5' end of the RNA but the significance of this positioning is not known. In a heterologous intron the NRS functions optimally when positioned close to the authentic 5' splice site. This observation led us to investigate the basis of the position dependence. Four explanations were put forth and stressed the role of three major elements involved in splicing, the 3' splice site, the 5' splice site, and the 5' end cap structure. NRS function was unrelated to its position relative to the 3' splice site or the cap structure and appeared to depend on its position relative to the authentic 5' splice site. We conclude that position dependence may reflect distance constraints necessary for competition of the NRS with the authentic 5' splice site for pairing with the 3' splice sites
Phase-Shifted Based Numerical Method for Modeling Frequency-Dependent Effects on Seismic Reflections
Chen, Xuehua; Qi, Yingkai; He, Xilei; He, Zhenhua; Chen, Hui
2016-04-01
The significant velocity dispersion and attenuation has often been observed when seismic waves propagate in fluid-saturated porous rocks. Both the magnitude and variation features of the velocity dispersion and attenuation are frequency-dependent and related closely to the physical properties of the fluid-saturated porous rocks. To explore the effects of frequency-dependent dispersion and attenuation on the seismic responses, in this work, we present a numerical method for seismic data modeling based on the diffusive and viscous wave equation (DVWE), which introduces the poroelastic theory and takes into account diffusive and viscous attenuation in diffusive-viscous-theory. We derive a phase-shift wave extrapolation algorithm in frequencywavenumber domain for implementing the DVWE-based simulation method that can handle the simultaneous lateral variations in velocity, diffusive coefficient and viscosity. Then, we design a distributary channels model in which a hydrocarbon-saturated sand reservoir is embedded in one of the channels. Next, we calculated the synthetic seismic data to analytically and comparatively illustrate the seismic frequency-dependent behaviors related to the hydrocarbon-saturated reservoir, by employing DVWE-based and conventional acoustic wave equation (AWE) based method, respectively. The results of the synthetic seismic data delineate the intrinsic energy loss, phase delay, lower instantaneous dominant frequency and narrower bandwidth due to the frequency-dependent dispersion and attenuation when seismic wave travels through the hydrocarbon-saturated reservoir. The numerical modeling method is expected to contribute to improve the understanding of the features and mechanism of the seismic frequency-dependent effects resulted from the hydrocarbon-saturated porous rocks.
Energy Technology Data Exchange (ETDEWEB)
Royer, A. [European Synchrotron Radiation Facility (ESRF), 38 - Grenoble (France); Bastie, P. [Laboratoire de Spectrometrie Physique, Universite Joseph Fourier, Grenoble I-CNRS, UMR 5588, BP 87, F-38402, Saint-Martin-d`Heres Cedex (France); Veron, M. [LTPCM, UMR.CNRS/INPG/UJF, BP 75, F-38402, Saint-Martin-d`Heres Cedex (France)
1997-08-30
High-energy X-ray synchrotron radiation was used to measure internal strains inside the bulk of creep deformed AM1 single crystal superalloy specimen. A sample creep deformed at 1050 C with {gamma}` raft-like precipitates was studied `in situ` in temperature. The superstructure reflections (100) and (001) as well as fundamental reflections (200) and (002) were measured up to the temperature of deformation using a high-resolution triple crystal diffractometer. The lattice parameter distribution which is related to internal stress distribution was determined for each phase in parallel and perpendicularly to the rafts. It was shown that these parameters depend strongly on the thermomechanical history of the analysed material and on the temperature at which measurement is performed. (orig.) 12 refs.
Miller, Mollie E; Sigmon, Stacey C
2015-08-01
While rates of smoking in the general population have decreased in recent years, dramatic disparities remain among disadvantaged subgroups of smokers, particularly those with concurrent substance abuse. Prevalence rates of smoking among opioid-dependent patients, for example, are fourfold those of the general population. While pharmacotherapies are recommended as a first-line treatment for nicotine dependence, the few studies that have investigated their effectiveness in this population have shown dramatically poorer outcomes compared to the general population. Indeed, these findings have led some researchers to suggest that pharmacotherapies may simply be ineffective in opioid-maintained smokers. In this commentary, we briefly summarize the extant literature on pharmacotherapies in opioid-maintained smokers and contribute new data investigating the contribution of bupropion on smoking outcomes in 81 methadone- and buprenorphine-maintained participants from two randomized trials of financial incentives for smoking cessation. We also discuss several important parameters (ie, timing of the quit attempt, medication adherence, nicotine withdrawal) that may be leveraged to strengthen smoking pharmacotherapy outcomes in opioid-dependent patients. Taken together, an improved understanding of these issues will aid efforts to reduce tobacco-related health disparities in this group of challenging smokers. PMID:26180219
Waro Nakanishi; Satoko Hayashi; Akito Tanioku
2009-01-01
Nuclear couplings for the Se-Se bonds, 1 J(Se, Se), are analyzed on the basis of the molecular orbital (MO) theory. The values are calculated by employing the triple ζ basis sets of the Slater type at the DFT level. 1 J(Se, Se) are calculated modeled by MeSeSeMe (1a), which shows the typical torsional angular dependence on ϕ(CMeSeSeCMe). The dependence explains well the observed 1 J obsd (Se, Se) of small values (≤ 64 Hz) for RSeSeR′ (1) (simple derivatives of 1a) and large values (330–380 Hz...
International Nuclear Information System (INIS)
In this thesis we report on the rst results on the transverse target-spin asymmetry associated with deeply virtual Compton scattering on the proton. It is shown that this asymmetry can provide one of the rare possibilities to access the Generalized Parton Distribution (GPD) E of the nucleon, and thus, through models for E, also to the total angular momentum of u and d quarks in the nucleon. The measurement was performed using the 27.6 GeV positron beam of the HERA storage ring and the transversely polarized hydrogen target of the HERMES experiment at DESY. The two leading azimuthal amplitudes of the asymmetry are extracted from the HERMES 2002-2004 data, corresponding to an integrated luminosity of 65.3 pb.1. By comparing the results obtained at HERMES and theoretical predictions based on a phenomenological model of GPDs, we obtain a model-dependent constraint on the total angular momentum of quarks in the nucleon. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Ye, Zhenyu
2007-02-15
In this thesis we report on the rst results on the transverse target-spin asymmetry associated with deeply virtual Compton scattering on the proton. It is shown that this asymmetry can provide one of the rare possibilities to access the Generalized Parton Distribution (GPD) E of the nucleon, and thus, through models for E, also to the total angular momentum of u and d quarks in the nucleon. The measurement was performed using the 27.6 GeV positron beam of the HERA storage ring and the transversely polarized hydrogen target of the HERMES experiment at DESY. The two leading azimuthal amplitudes of the asymmetry are extracted from the HERMES 2002-2004 data, corresponding to an integrated luminosity of 65.3 pb.1. By comparing the results obtained at HERMES and theoretical predictions based on a phenomenological model of GPDs, we obtain a model-dependent constraint on the total angular momentum of quarks in the nucleon. (orig.)
Orbital angular momentum and the parton model
Energy Technology Data Exchange (ETDEWEB)
Ratcliffe, P.G.
1987-06-25
The role of orbital angular momentum is discussed within the framework of the parton model. It is shown that a consistent interpretation of the Altarelli-Parisi equations governing the Q/sup 2/-evolution of helicity-weighted parton distributions necessitates the assumption that partons carry a large orbital angular momentum, contrary to popular belief. In developing the arguments presented, the Altarelli-Parisi formalism is extended to include orbital angular momentum dependence.
Energy Technology Data Exchange (ETDEWEB)
Takemoto, Hiroki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Horiuchi, Hisashi [Kyoto Univ. (Japan). Dept. of Physics; Ono, Akira [Tohoku Univ., Sendai (Japan). Dept. of Physics
2000-05-01
We investigate how clustering structure of neutron drip-line nucleus {sup 19}B is reflected in heavy-ion reactions. We compare {sup 19}B fragmentation in {sup 19}B+{sup 14}N reactions with {sup 13}B fragmentation in {sup 13}B+{sup 14}N reactions calculated by antisymmetrized molecular dynamics, where {sup 19}B has a well developed cluster structure in its ground state while {sup 13}B has no clustering features in its structure. The clustering structure of the {sup 19}B nucleus is reflected in its fragmentation as the simultaneous breakup of {sup 19}B into He and Li isotopes, and we investigate the dependence of this cluster breakup of the {sup 19}B nucleus on incident energy. We find that the most adequate incident energy for verification of the clustering structure of the {sup 19}B nucleus by the use of the coincident experiment between He and Li isotopes is around 30 MeV/nucleon. This incident-energy dependence can be explained in terms of the competition between the mean-field effect and nucleon-nucleon collision processes. The mean-field effect causes the cluster breakup of the {sup 19}B nucleus, while nucleon-nucleon collision processes work to destroy constituent clusters of the {sup 19}B nucleus. We also investigate the influence of the neutron-rich property of the {sup 19}B nucleus. (author)
International Nuclear Information System (INIS)
The temperature dependence between 30 and 300 K of the intensities of 24 reflections of the column-composite structure Hg0.776(BEDT-TTF)SCN [Wang, Beno, Carlson, Thorup, Murray, Porter, Williams, Maly, Bu, Petricek, Cisarova, Coppens, Jung, Whangbo, Shirber and Overmyer (1991). Chem. Mater. 3, 508-513; BEDT-TTF=3,4,3',4'-bis(ethylenedithio)-2,2',5,5'-tetrathiafulvalene] has been analyzed in terms of a model including phason temperature factors. The temperature dependence of the main and first-order satellite reflections is reasonably well reproduced in a refinement with 236 observations and four variables. The results are interpreted in terms of a temperature independence of the static displacement amplitudes. The room-temperature r.m.s. phason fluctuations of the mercury sublattice are 50(2) . This value implies that the mean mercury displacement amplitude will increase by ∝60% on lowering of the temperature to within the liquid-helium range. The thermal contraction on cooling is the same for the two sublattices. (orig.)
Faces in-between: evaluations reflect the interplay of facial features and task-dependent fluency.
Winkielman, Piotr; Olszanowski, Michal; Gola, Mateusz
2015-04-01
Facial features influence social evaluations. For example, faces are rated as more attractive and trustworthy when they have more smiling features and also more female features. However, the influence of facial features on evaluations should be qualified by the affective consequences of fluency (cognitive ease) with which such features are processed. Further, fluency (along with its affective consequences) should depend on whether the current task highlights conflict between specific features. Four experiments are presented. In 3 experiments, participants saw faces varying in expressions ranging from pure anger, through mixed expression, to pure happiness. Perceivers first categorized faces either on a control dimension, or an emotional dimension (angry/happy). Thus, the emotional categorization task made "pure" expressions fluent and "mixed" expressions disfluent. Next, participants made social evaluations. Results show that after emotional categorization, but not control categorization, targets with mixed expressions are relatively devalued. Further, this effect is mediated by categorization disfluency. Additional data from facial electromyography reveal that on a basic physiological level, affective devaluation of mixed expressions is driven by their objective ambiguity. The fourth experiment shows that the relative devaluation of mixed faces that vary in gender ambiguity requires a gender categorization task. Overall, these studies highlight that the impact of facial features on evaluation is qualified by their fluency, and that the fluency of features is a function of the current task. The discussion highlights the implications of these findings for research on emotional reactions to ambiguity. PMID:25642724
On Dunkl angular momenta algebra
Feigin, Misha; Hakobyan, Tigran
2015-11-01
We consider the quantum angular momentum generators, deformed by means of the Dunkl operators. Together with the reflection operators they generate a subalgebra in the rational Cherednik algebra associated with a finite real reflection group. We find all the defining relations of the algebra, which appear to be quadratic, and we show that the algebra is of Poincaré-Birkhoff-Witt (PBW) type. We show that this algebra contains the angular part of the Calogero-Moser Hamiltonian and that together with constants it generates the centre of the algebra. We also consider the gl( N ) version of the subalge-bra of the rational Cherednik algebra and show that it is a non-homogeneous quadratic algebra of PBW type as well. In this case the central generator can be identified with the usual Calogero-Moser Hamiltonian associated with the Coxeter group in the harmonic confinement.
X-Ray Reflectivity from the Surface of a Liquid Crystal:
DEFF Research Database (Denmark)
Pershan, P.S.; Als-Nielsen, Jens Aage
1984-01-01
X-ray reflectivity from the surface of a nematic liquid crystal is interpreted as the coherent superposition of Fresnel reflection from the surface and Bragg reflection from smectic order induced by the surface. Angular dependence of the Fresnel effect yields information on surface structure. Mea....... Measurement of the intensity of diffuse critical scattering relative to the Fresnel reflection yields the absolute value of the critical part of the density-density correlation function....
X-Ray Reflectivity from the Surface of a Liquid Crystal:
DEFF Research Database (Denmark)
Pershan, P.S.; Als-Nielsen, Jens Aage
1984-01-01
X-ray reflectivity from the surface of a nematic liquid crystal is interpreted as the coherent superposition of Fresnel reflection from the surface and Bragg reflection from smectic order induced by the surface. Angular dependence of the Fresnel effect yields information on surface structure....... Measurement of the intensity of diffuse critical scattering relative to the Fresnel reflection yields the absolute value of the critical part of the density-density correlation function....
International Nuclear Information System (INIS)
The growth of BaZrO3 (BZO) in pulsed laser deposited YBa2Cu3O7−δ (YBCO) thin films was studied by varying the deposition temperature. It was found that there are three deposition temperature ranges based on the properties of Jc(θ), the angular dependence of critical current density. Samples made at a relatively low temperature (low-T samples) do not show a c-axis peak in Jc(θ) whereas mid-T samples exhibit a peak as B∥c-axis of YBCO. In high-T samples the c-peak disappears again. In the low-T samples BZO rods are too splayed and short for a c-axis peak whereas in the high-T samples vortices move along correlated, but shortened rods as well as along stacking faults, which causes the c-axis peak to disappear. The superconducting properties of the films were studied with both magnetic and transport measurements and the structural properties were characterized using X-ray diffraction and transmission electron microscopy. Correlations between the structural and superconducting properties were analyzed using the vortex path model. - Highlights: • Growth temperature (Tdep) dependent pinning structure in YBa2Cu3O7−δ is revealed. • Three different regimes of Tdep related to BaZrO3 pinning structure are found. • A c-axis peak in angular dependence of critical current density Jc at certain Tdep. • The theoretical vortex path model explains the behavior of angular dependence of Jc. • The model is in good agreement with structural properties
International Nuclear Information System (INIS)
We studied the influence of three gravity levels (0, 1 and 1.8 g) on unilateral lung aeration in a left lateral position by the application of absolute electrical impedance tomography. The electrical resistivity of the lung tissue was considered to be a meaningful indicator for lung aeration since changes in resistivity have already been validated in other studies to be proportional to changes in lung volume. Twenty-two healthy volunteers were studied during parabolic flights with three phases of different gravity, each lasting ∼20–22 s. Spontaneous breathing at normal tidal volume VT and at increased VT was performed. During transition to hyper-gravity mean expiratory resistivities (±SD in Ωm) increased at normal VT in the upper (right) lung from 7.6 ± 1.5 to 8.0 ± 1.7 and decreased from 5.8 ± 1.2 to 5.7 ± 1.2 in the lower (left) lung. Inspiratory resistivity values are 8.3 ± 1.6 to 8.8 ± 1.8 (right) and 6.3 ± 1.3 to 6.0 ± 1.3 (left). At increased VT, the changes in resistivities at end-expiration were 7.7 ± 1.5 to 8.0 ± 1.7 (right) and 5.8 ± 1.2 to 5.7 ± 1.2 (left). Corresponding end-inspiratory values are 9.9 ± 1.9 to 10.0 ± 2.0 (right) and 8.6 ± 2.1 to 7.9 ± 2.0 (left). During weightlessness, the distortion in the lungs disappeared and both lungs showed a nearly identical aeration, which was between the levels displayed at normal gravity. The small increase in resistivity for the upper lung during transition to hyper-gravity from 1 to 1.8 g at increased VT suggests that the degressive part of the pressure–volume curve has already been reached at end-inspiration. The results for a left lateral position are in agreement with West's lung model which has been introduced for cranio-caudal gravity dependence in the lungs. (paper)
Webber, Matthew W.; Lewis, Nikole K.; Marley, Mark; Morley, Caroline; Fortney, Jonathan J.; Cahoy, Kerri
2015-05-01
We use a planetary albedo model to investigate variations in visible wavelength phase curves of exoplanets. Thermal and cloud properties for these exoplanets are derived using one-dimensional radiative-convective and cloud simulations. The presence of clouds on these exoplanets significantly alters their planetary albedo spectra. We confirm that non-uniform cloud coverage on the dayside of tidally locked exoplanets will manifest as changes to the magnitude and shift of the phase curve. In this work, we first investigate a test case of our model using a Jupiter-like planet, at temperatures consistent to 2.0 AU insolation from a solar type star, to consider the effect of H2O clouds. We then extend our application of the model to the exoplanet Kepler-7b and consider the effect of varying cloud species, sedimentation efficiency, particle size, and cloud altitude. We show that, depending on the observational filter, the largest possible shift of the phase curve maximum will be ˜2°-10° for a Jupiter-like planet, and up to ˜30° (˜0.08 in fractional orbital phase) for hot-Jupiter exoplanets at visible wavelengths as a function of dayside cloud distribution with a uniformly averaged thermal profile. The models presented in this work can be adapted for a variety of planetary cases at visible wavelengths to include variations in planet-star separation, gravity, metallicity, and source-observer geometry. Finally, we tailor our model for comparison with, and confirmation of, the recent optical phase-curve observations of Kepler-7b with the Kepler space telescope. The average planetary albedo can vary between 0.1 and 0.6 for the 1300 cloud scenarios that were compared to the observations. Many of these cases cannot produce a high enough albedo to match the observations. We observe that smaller particle size and increasing cloud altitude have a strong effect on increasing albedo. In particular, we show that a set of models where Kepler-7b has roughly half of its dayside
International Nuclear Information System (INIS)
Inclusive energy spectra and angular distributions have been measured for light charged particles with Z=1-4 emitted in the interaction of 22Ne ions with a 181Ta target. The reaction products were analysed and detected by means of a system of ΔE-E telescopes placed in the focal plane of a magnetic spectrometer. Energy spectra of light particles (p, d, t and He, Li, Be isotopes) correspond to the calculated kinematic limits taking into account the rotational energy of the residual nucleus. The angular distributions of the high-energy particles are strongly forward directed. The data obtained are analysed on the basis of the moving source, rotating hot spot, massive transfer and breakup-fusion models. The relative yields of the different isotopes and their most probable energies are described by the massive transfer model. The qualitative behaviour of the spectra in the vicinity of the kinematic limits can be explained in terms of the breakup-fusion model
International Nuclear Information System (INIS)
The purpose of the study was to create detector element-specific angular correction factors for each detector of the MatriXX planar ion chamber array and compare them to vendor-default angular correction factors. Additionally, the impact of both factors on gamma index was quantified using two corrections. The correction factor of each element is determined irradiating the detector at different incidences by the ratio of the calculated expected dose to the MatriXX measured dose as a gantry angle function. To evaluate its impact, sixty-five pre-irradiated patient-specific dose validations were re-analyzed using the gamma index with: 3%/3 mm, 2%/2 mm, 1%/1 mm criteria. The factors for 6 MV were found to differ (7%) from the default ones for specific angles particularly for 85 degree centigrade to 95 degree centigrade. For 10 MV, differences (1.0%) existed when correction factors were created using various ROI's. Two corrections were proposed, absolute differences for 3%/3 mm, 2%/2 mm, and 1%/1 mm were up to 1.5%, 4.2% and 4.1% ( p < 0.01), respectively. Large differences in the default and specific factors were noted for 6 MV and lead to improvement of the absolute gamma index value of up to 4.2%. In general, gamma index value increases for patient specific dose validations when using device specific factors. (Author)
Janković, Marija R.; Dmitrašinović, V.
2016-02-01
We use 57 recently found topological satellites of Broucke-Hadjidemetriou-Hénon's periodic orbits with values of the topological exponent k ranging from k =3 to k =58 to plot the angular momentum L as a function of the period T , with both L and T rescaled to energy E =-0.5 . Upon plotting L (T /k ) we find that all our solutions fall on a curve that is virtually indiscernible by the naked eye from the L (T ) curve for nonsatellite solutions. The standard deviation of the satellite data from the sixth-order polynomial fit to the progenitor data is σ =0.13 . This regularity supports Hénon's 1976 conjecture that the linearly stable Broucke-Hadjidemetriou-Hénon orbits are also perpetually, or Kol'mogorov-Arnol'd-Moser, stable.
Janković, Marija R
2016-01-01
We use 57 recently found topological satellites of Broucke-Hadjidemetriou-Henon's periodic orbits with values of the topological exponent $k$ ranging from $k$ = 3 to $k$ = 58 to plot the angular momentum $L$ as a function of the period $T$, with both $L$ and $T$ rescaled to energy $E=-\\frac12$. Upon plotting $L(T/k)$ we find that all our solutions fall on a curve that is virtually indiscernible by naked eye from the $L(T)$ curve for non-satellite solutions. The standard deviation of the satellite data from the sixth-order polynomial fit to the progenitor data is $\\sigma = 0.13$. This regularity supports Henon's 1976 conjecture that the linearly stable Broucke-Hadjidemetriou-Henon orbits are also perpetually, or Kolmogorov-Arnold-Moser stable.
Karpov, Valeri
2015-01-01
A comprehensive guide to AngularJS, Google's open-source client-side framework for app development. Most of the existing guides to AngularJS struggle to provide simple and understandable explanations for more advanced concepts. As a result, some developers who understand all the basic concepts of AngularJS struggle when it comes to building more complex real-world applications. Professional AngularJS provides a thorough understanding of AngularJS, covering everything from basic concepts, such as directives and data binding, to more advanced concepts like transclusion, build systems, and auto
Geng, Xu; Angal, Amit; Sun, Junqiang; Chen, Hongda; Wu, Aisheng; Li, Yonghong; Link, Daniel; Xiong, Xiaoxiong
2014-09-01
The MODerate resolution Imaging Spectroradiometer (MODIS) has 20 reflective solar bands (RSB), which are calibrated using a solar diffuser (SD) and near-monthly scheduled lunar observations via a space view (SV) port. The sensor responses observed at two different angles of incidence (AOI) from the SD and lunar measurements are used to track the on-orbit RSB gain changes as well as the response versus scan-angle (RVS) changes. The MODIS RSB have experienced wavelength dependent degradation since launch with the larger degradation observed at the shorter wavelengths. In addition to the SD and lunar observations, the MODIS Characterization Support Team (MCST) regularly monitors the response trending at multiple AOI over selected desert sites. In Collection 6 (C6), a new algorithm using the EV measurements from pseudoinvariant desert sites was developed to better characterize the MODIS scan-angle dependence and it led to a significant improvement in the long-term calibration consistency of the MODIS Level 1B (L1B) products. This approach is formulated for all RSB, and its application was recently extended to Terra band 10, leading to a significant improvement in the ocean-color products. This paper discusses the current status and performance of the on-orbit RVS characterization as applied in C6. Also, the various challenges and future improvement strategies associated with trending the EV response for the high-gain ocean bands are discussed.
Achromatic orbital angular momentum generator
International Nuclear Information System (INIS)
We describe a novel approach for generating light beams that carry orbital angular momentum (OAM) by means of total internal reflection in an isotropic medium. A continuous space-varying cylindrically symmetric reflector, in the form of two glued hollow axicons, is used to introduce a nonuniform rotation of polarization into a linearly polarized input beam. This device acts as a full spin-to-orbital angular momentum convertor. It functions by switching the helicity of the incoming beam's polarization, and by conservation of total angular momentum thereby generates a well-defined value of OAM. Our device is broadband, since the phase shift due to total internal reflection is nearly independent of wavelength. We verify the broad-band behaviour by measuring the conversion efficiency of the device for three different wavelengths corresponding to the RGB colours, red, green and blue. An average conversion efficiency of 95% for these three different wavelengths is observed. This device may find applications in imaging from micro- to astronomical systems where a white vortex beam is needed. (paper)
Fission at high angular momenta
International Nuclear Information System (INIS)
By studies on the system 40Ar+165Ho by means of selected measuring methods which made a differential selection of certain angular momentum ranges and by this a discrimination between ''fast fission'' and compound-nucleus fission possible the validity of fundamental predictions of the model of the ''fast fission'' hitherto experimentally no yet confirmed was studied: 1) At the turning point of the trajectory for ''fast fission'' calculated by Gregoire the corresponding shape of which must be responsible for the angular distribution the centers of the two fragments must be separated by about 11 fm. 2) The widths of the mass distributions after ''fast fission'' and compound-nucleus fission must be different by a factor 2. The measurements of the angular dependence showed that both prediction cannot be simultaneously brought into accordance with the experimental results. The results of coincidence measurements between fission fragments and alpha particles confirmed the assumption mentioned under topic 2. The analysis of the angular dependence then yielded for the shape of the nuclear complex leading to ''fast fission'' a more compact shape than that indicated by Gregoire, namely with a distance of the fragments of about 7 fm. (orig.)
International Nuclear Information System (INIS)
Poly(9,9-dioctylfluorene) (PFO) polymer films were deposited by matrix-assisted pulsed laser evaporation (MAPLE) technique. The polymer was diluted (0.5 wt%) in tetrahydrofuran and, once cooled to liquid nitrogen temperature, it was irradiated with a KrF excimer laser. 10,000 laser pulses were used to deposit PFO films on Si substrates at different temperatures (-16, 30, 50 and 70 deg. C). One PFO film was deposited with 16,000 laser pulses at a substrate temperature of 50 deg. C. The morphology, optical and structural properties of the films were investigated by SEM, AFM, PL and FTIR spectroscopy. SEM inspection showed different characteristic features on the film surface, like deflated balloons, droplets and entangled polymer filaments. The roughness of the films was, at least partially, controlled by substrate heating, which however had the effect to reduce the deposition rate. The increase of the laser pulse number modified the target composition and increased the surface roughness. The angular distribution of the material ejected from the target confirmed the forward ejection of the target material. PFO films presented negligible modification of the chemical structure respect to the bulk material.
Pershan, Peter S.; Als-Nielsen, J.
1984-01-01
X-ray reflectivity from the surface of a nematic liquid crystal is interpreted as the coherent superposition of Fresnel reflection from the surface and Bragg reflection from smectic order induced by the surface. Angular dependence of the Fresnel effect yields information on surface structure. Measurement of the intensity of diffuse critical scattering relative to the Fresnel reflection yields the absolute value of the critical part of the density-density correlation function.
Quark Orbital Angular Momentum
Burkardt Matthias
2015-01-01
Definitions of orbital angular momentum based on Wigner distributions are used as a framework to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. We find that the difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that change is similar to the mechanism that causes transverse single-spin asy...
Partonic orbital angular momentum
Arash, Firooz; Taghavi-Shahri, Fatemeh; Shahveh, Abolfazl
2013-04-01
Ji's decomposition of nucleon spin is used and the orbital angular momentum of quarks and gluon are calculated. We have utilized the so called valon model description of the nucleon in the next to leading order. It is found that the average orbital angular momentum of quarks is positive, but small, whereas that of gluon is negative and large. Individual quark flavor contributions are also calculated. Some regularities on the total angular momentum of the quarks and gluon are observed.
Marković Vladimir M.; Krstić Dragana; Stevanović Nenad; Nikezić Dragoslav R.
2013-01-01
Total number and angular albedo were calculated for commonly used shielding materials, water, concrete, and iron, for photons with initial energies from 10 keV up to 10 MeV and normal incident angle. Influence of material thickness on total number albedo was also investigated. Double differential albedo was determined from simulation of photon transport through materials by using PENELOPE and MCNP software. Backscattered photons were scored and grouped in equal intervals of energy and a...
Trainor, Thomas A
2015-01-01
An established phenomenology and theoretical interpretation of $p$-$p$ collision data at lower collision energies should provide a reference for $p$-$p$ and other collision systems at higher energies, against which claims of novel physics may be tested. The description of $p$-$p$ collisions at the relativistic heavy ion collider (RHIC) has remained incomplete even as claims for collectivity and other novelties in data from smaller systems at the large hadron collider (LHC) have emerged recently. In this study we report the charge-multiplicity dependence of two-dimensional (2D) angular correlations and of single-particle (SP) densities on transverse rapidity $y_t$ and pseudorapidity $\\eta$ from 200 GeV $p$-$p$ collisions. We define a comprehensive and self-consistent two-component (soft + hard) model (TCM) for hadron production and report a significant $p$-$p$ nonjet (NJ) quadrupole component as a third (angular-correlation) component. Our results have implications for $p$-$p$ centrality, the underlying event ...
Trainor, Thomas A.; Prindle, Duncan J.
2016-01-01
An established phenomenology and theoretical interpretation of p -p collision data at lower collision energies should provide a reference for p -p and other collision systems at higher energies, against which claims of novel physics may be tested. The description of p -p collisions at the relativistic heavy ion collider has remained incomplete even as claims for collectivity and other novelties in data from smaller systems at the large hadron collider have emerged recently. In this study we report the charge-multiplicity dependence of two-dimensional angular correlations and of single-particle (SP) densities on transverse rapidity yt and pseudorapidity η from 200 GeV p -p collisions. We define a comprehensive and self-consistent two-component (soft+hard ) model for hadron production and report a significant p -p nonjet quadrupole component as a third (angular-correlation) component. Our results have implications for p -p centrality, the underlying event, collectivity in small systems and the existence of flows in high-energy nuclear collisions.
Rotations and angular momentum
International Nuclear Information System (INIS)
This paper is devoted to the analysis of rotational invariance and the properties of angular momentum in quantum mechanics. In particular, the problem of addition of angular momenta is treated in detail, and tables of Clebsch-Gordan coefficients are included
Directory of Open Access Journals (Sweden)
Lind L
2012-07-01
Full Text Available Lars Lind,1 Johannes Hulthe,2,3 Annika Johansson,3 Ewa Hedner31Department of Medicine, University Hospital, Uppsala, 2Sahlgrenska Hospital, Gothenburg, 3AstraZeneca Research and Development, Mölndal, SwedenBackground: Inflammation induced by either endotoxin or vaccination has previously been shown to impair endothelium-dependent vasodilation (EDV in healthy young individuals. However, the vascular effects of these two mechanisms of inducing inflammation have not been compared in the same individuals.Methods: Twelve young healthy males were studied at the same time of the day on three occasions in a random order; on one occasion 4 hours following an endotoxin injection (Escherichia coli endotoxin, 20 IU/kg, on another occasion 8 hours following vaccination against Salmonella typhi, and on a third occasion 4 hours following a saline control injection. EDV and endothelium-independent vasodilation (EIDV were evaluated by local infusions of acetylcholine and sodium nitroprusside in the brachial artery, and forearm blood flow was measured with venous occlusion plethysmography. The augmentation index was determined by pulse wave analysis as an index of pulse wave reflection.Results: Both endotoxin and vaccination impaired EDV to a similar degree compared with the saline control (P = 0.005 and P = 0.014, respectively. EIDV was not significantly affected by inflammation. Endotoxin, but not vaccination, increased body temperature and circulating levels of intracellular adhesion molecule-1 and interleukin-6. Augmentation index was not affected by the interventions.Conclusion: Despite the fact that endotoxin induced a more pronounced degree of inflammation than vaccination, both inflammatory challenges impaired EDV to a similar degree, supporting the view that different inflammatory stimuli could induce harmful effects on the vasculature.Keywords: endothelium, endotoxin, vaccination, vasodilation, inflammation
Energy Technology Data Exchange (ETDEWEB)
Grandum, Oddbjoern
1997-12-31
In optimizing solar systems, it is necessary to know the spectral and angular dependence of the radiation. The general nonlinear character of most solar energy systems accentuates this. This thesis describes a spectroradiometer that will measure both the direct component of the solar radiation and the angular dependence of the diffuse component. Radiation from a selected part of the sky is transported through a movable set of tube sections on to a stationary set of three monochromators with detectors. The beam transport system may effectively be looked upon as a single long tube aimed at a particular spot in the sky. The half value of the effective opening angle is 1.3{sup o} for diffuse radiation and 2.8{sup o} for direct radiation. The whole measurement process is controlled and operated by a PC and normally runs without manual attention. The instrument is built into a caravan. The thesis describes in detail the experimental apparatus, calibration and measurement accuracies. To map the diffuse radiation, one divides the sky into 26 sectors of equal solid angle. A complete measurement cycle is then made at a random point within each sector. These measurements are modelled by fitting to spherical harmonics, enforcing symmetry around the solar direction and the horizontal plane. The direct radiation is measured separately. Also the circumsolar sector is given special treatment. The measurements are routinely checked against global radiation measured in parallel by a standard pyranometer, and direct solar radiation by a pyrheliometer. An extensive improvement programme is being planned for the instrument, including the use of a photomultiplier tube to measure the UV part of the spectrum, a diode array for the 400-1100 nm range, and use of a Ge diode for the 1000-1900 nm range. 78 refs., 90 figs., 31 tabs.
Angular Momentum and Galaxy Formation Revisited
Romanowsky, Aaron J.; Fall, S. Michael
2012-12-01
Motivated by a new wave of kinematical tracers in the outer regions of early-type galaxies (ellipticals and lenticulars), we re-examine the role of angular momentum in galaxies of all types. We present new methods for quantifying the specific angular momentum j, focusing mainly on the more challenging case of early-type galaxies, in order to derive firm empirical relations between stellar j sstarf and mass M sstarf (thus extending earlier work by Fall). We carry out detailed analyses of eight galaxies with kinematical data extending as far out as 10 effective radii, and find that data at two effective radii are generally sufficient to estimate total j sstarf reliably. Our results contravene suggestions that ellipticals could harbor large reservoirs of hidden j sstarf in their outer regions owing to angular momentum transport in major mergers. We then carry out a comprehensive analysis of extended kinematic data from the literature for a sample of ~100 nearby bright galaxies of all types, placing them on a diagram of j sstarf versus M sstarf. The ellipticals and spirals form two parallel j sstarf-M sstarf tracks, with log-slopes of ~0.6, which for the spirals are closely related to the Tully-Fisher relation, but for the ellipticals derives from a remarkable conspiracy between masses, sizes, and rotation velocities. The ellipticals contain less angular momentum on average than spirals of equal mass, with the quantitative disparity depending on the adopted K-band stellar mass-to-light ratios of the galaxies: it is a factor of ~3-4 if mass-to-light ratio variations are neglected for simplicity, and ~7 if they are included. We decompose the spirals into disks and bulges and find that these subcomponents follow j sstarf-M sstarf trends similar to the overall ones for spirals and ellipticals. The lenticulars have an intermediate trend, and we propose that the morphological types of galaxies reflect disk and bulge subcomponents that follow separate, fundamental j sstarf
Lenk, D.; Hemmida, M.; Morari, R.; Zdravkov, V. I.; Ullrich, A.; Müller, C.; Sidorenko, A. S.; Horn, S.; Tagirov, L. R.; Loidl, A.; von Nidda, H.-A. Krug; Tidecks, R.
2016-05-01
We investigated the upper critical magnetic field Hc of a superconductor-ferromagnet (S/F) bilayer of Nb/Cu41Ni59 and a Nb film (as reference). We obtained the dependence of Hc ⊥ and Hc ∥ (perpendicular and parallel to the film plane, respectively) on the temperature T by measurements of the resistive transitions and the dependence on the inclination angle θ of the applied field to the film plane, by nonresonant microwave absorption. Over a wide range, Hc ⊥ and Hc ∥ show the temperature dependence predicted by the Ginzburg-Landau theory. At low temperatures and close to the critical temperature, deviations are observed. While Hc(θ ) of the Nb film follows the Tinkham prediction for thin superconducting films, the Nb/Cu41Ni59 -bilayer data exhibit deviations when θ approaches zero. We attribute this finding to the additional anisotropy induced by the quasi-one-dimensional Fulde-Ferrell-Larkin-Ovchinnikov (FFLO)-like state and propose a new vortex structure in S/F bilayers, adopting the segmentation approach from high-temperature superconductors.
International Nuclear Information System (INIS)
The present work investigates the anisotropy of the γ-radiation of optically orientated radioactive 203Hg atomic nuclei. Through the simultaneous action of direct and alternating magnetic fields on the optically pumped spin system, a time-dependent (dynamic) orientation structure is created which is expressed by a time-modulated, anisotropic γ-radiation. By measuring the anisotropy and the time modulations of the intensity of the γ-radiation using various outlined measuring methods, the dynamic orientation structure is examined in detail. (orig./LH)
Pretzelosity TMD and Quark Orbital Angular Momentum
Lorce, Cédric; Pasquini, B.
2015-01-01
We study the connection between the quark orbital angular momentum and the pretzelosity transverse-momentum dependent parton distribution function. We discuss the origin of this relation in quark models, identifying as key ingredient for its validity the assumption of spherical symmetry for the nucleon in its rest frame. Finally we show that the individual quark contributions to the orbital angular momentum obtained from this relation can not be interpreted as the intrinsic contributions, but...
Liebe, Wolfgang
1944-01-01
In many studies, especially of nonstationary flight motion, it is necessary to determine the angular velocities at which the airplane rotates about its various axes. The three-component recorder is designed to serve this purpose. If the angular velocity for one flight attitude is known, other important quantities can be derived from its time rate of change, such as the angular acceleration by differentiations, or - by integration - the angles of position of the airplane - that is, the angles formed by the airplane axes with the axis direction presented at the instant of the beginning of the motion that is to be investigated.
Quark Orbital Angular Momentum
Directory of Open Access Journals (Sweden)
Burkardt Matthias
2015-01-01
Full Text Available Definitions of orbital angular momentum based on Wigner distributions are used as a framework to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. We find that the difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that change is similar to the mechanism that causes transverse single-spin asymmetries in semi-inclusive deep-inelastic scattering.
International Nuclear Information System (INIS)
For many years the Institute of Physics has published books on hot topics based on a collection of reprints from different journals, including some remarks by the editors of each volume. The book on Optical Angular Momentum, edited by L Allen, S M Barnett and M J Padgett, is a recent addition to the series. It reproduces forty four papers originally published in different journals and in a few cases it provides direct access to works not easily accessible to a web navigator. The collection covers nearly a hundred years of progress in physics, starting from an historic 1909 paper by Poynting, and ending with a 2002 paper by Padgett, Barnett and coworkers on the measurement of the orbital angular momentum of a single photon. The field of optical angular momentum has expanded greatly, creating an interdisciplinary attraction for researchers operating in quantum optics, atomic physics, solid state physics, biophysics and quantum information theory. The development of laser optics, especially the control of single mode sources, has made possible the specific design of optical radiation modes with a high degree of control on the light angular momentum. The editors of this book are important figures in the field of angular momentum, having contributed to key progress in the area. L Allen published an historical paper in 1999, he and M J Padgett (together with M Babiker) produced few years ago a long review article which is today still the most complete basic introduction to the angular momentum of light, while S M Barnett has contributed several high quality papers to the progress of this area of physics. The editors' choice provides an excellent overview to all readers, with papers classified into eight different topics, covering the basic principles of the light and spin and orbital angular momentum, the laboratory tools for creating laser beams carrying orbital angular momentum, the optical forces and torques created by laser beams carrying angular momentum on
International Nuclear Information System (INIS)
The critical current density Jc as a function of the temperature T, magnetic field intensity H and angle θ between the direction of applied magnetic field and the c-axis of the samples was measured on epitaxial 10 at.% Ca-substituted YBa2Cu3O7-δ (YCBCO) thin films grown by the pulsed laser deposition technique on (001)-SrTiO3 (STO) and CeO2 buffered r-cut Al2O3 (CAO) substrates. Films exhibited comparable values of critical temperature (Tc∼78 K) while higher self-field Jc values for SrTiO3 were observed. Dissipation regimes related to growth boundary and intra-grain pinning mechanisms showed a qualitatively similar contribution for YCBCO films deposited on both substrates when the applied magnetic field direction is parallel to the c-axis (θ = 00). However, a weaker efficiency of pinning related to growth boundaries as well as a wider field range where this dissipation mechanism is active were observed for films grown on CeO2-buffered sapphire. These films exhibited a broad peak centred at θ = 00 in the Jc versus angle behaviour, not observed using a SrTiO3 substrate. The analysis of the Jc(H) dependences collected at θ = 900 revealed that this feature can be partially ascribed to a dramatic decrease of the intrinsic pinning efficiency
Van Essen, H.
2004-01-01
This paper addresses the problem of the separation of rotational and internal motion. It introduces the concept of average angular velocity as the moment of inertia weighted average of particle angular velocities. It extends and elucidates the concept of Jellinek and Li (1989) of separation of the energy of overall rotation in an arbitrary (non-linear) $N$-particle system. It generalizes the so called Koenig's theorem on the two parts of the kinetic energy (center of mass plus internal) to th...
Angular velocity discrimination
Kaiser, Mary K.
1990-01-01
Three experiments designed to investigate the ability of naive observers to discriminate rotational velocities of two simultaneously viewed objects are described. Rotations are constrained to occur about the x and y axes, resulting in linear two-dimensional image trajectories. The results indicate that observers can discriminate angular velocities with a competence near that for linear velocities. However, perceived angular rate is influenced by structural aspects of the stimuli.
Orbital angular momentum effects
International Nuclear Information System (INIS)
This paper reports that in the context of the parton model description of baryon structure orbital angular momentum effects have long been considered negligible. However, recent results obtained within the framework of QCD and presented in this talk indicate that a substantial fraction of the baryon spin may be carried as orbital angular momentum of its constituents. These results are of particular relevance in the light of new data on the spin structure of the proton recently published by the EMC collaboration
International Nuclear Information System (INIS)
Highlights: •BZO/YBCO multilayered films were irradiated using 200 MeV Xe ions along c-axis. •Size and spatial distribution of particles were tuned by the growth temperature. •The difference in growth temperatures stand out on the Jc(θ), especially for high B. •A shoulder behaviour occurs on the Jc(θ) in the multilayered films with CDs. •The inverse correlation between Jc and n-value emerges around B||c at high T. -- Abstract: BaZrO3/YBa2Cu3Oy quasi-multilayered films, in which the size and the spatial distribution of BaZrO3 nano-particles were controlled, were irradiated using 200 MeV Xe ions along the c-axis direction. When the BaZrO3 nano-particles were larger in size, the flux lines not captured by CDs, such as interstitial flux lines between CDs and double kinks of flux lines, can be pinned more effectively by the BaZrO3 nano-particles, so that the Jc enhances for high magnetic fields and high temperature. In addition, the inverse correlation between Jc and n-value appears at high temperature in increasing magnetic field for the film with correlated rows of the nano-particles which might be curved off the c-axis. These suggest that the hybrid flux pinning depends not only on the combination of one-dimensional (1D) and three-dimensional pinning centers (3D-PCs) but also on the size and the spatial distribution of the 3D-PCs
International Nuclear Information System (INIS)
Transmission spectra of a one-dimensional photonic crystal (PC) formed by two multilayer dielectric mirrors and a planar oriented layer of 5CB nematic liquid crystal (LC) that is sandwiched between these mirrors and serves as a structure defect are investigated experimentally. Specific features of the behavior of the spectrum of defect modes as a function of the angle of incidence of light on the crystal are studied for two polarizations: parallel and perpendicular to the director of the LC; the director either lies in the plane of incidence or is perpendicular to it. It is shown that, for the configurations considered, the maxima of the defect modes shift toward the short-wavelength region as the tilt angle of incidence radiation increases; this tendency is more manifest for the parallel-polarized component, when the director lies in the plane of incidence. In the latter case, the width of the photonic band gap (PBG) appreciably decreases. The temperature dependence of the polarization components of the transmission spectra of a PC is investigated in the case of normal incidence of light. The spectral shift of defect modes due to the variation of the refractive index of the LC at the nematic-isotropic liquid phase transition point is measured. It is shown that, in real PCs, the amplitude of defect modes decreases when approaching the center of the band gap, as well as when the number of layers in the dielectric mirrors increases. Theoretical transmission spectra of the PCs calculated by the method of recurrence relations with regard to the decay of defect modes are in good agreement with experimental data.
International Nuclear Information System (INIS)
Transmission spectra of a one-dimensional photonic crystal (PC) formed by two multilayer dielectric mirrors and a planar oriented layer of 5CB nematic liquid crystal (LC) that is sandwiched between these mirrors and serves as a structure defect are investigated experimentally. Specific features of the behavior of the spectrum of defect modes as a function of the angle of incidence of light on the crystal are studied for two polarizations: parallel and perpendicular to the director of the LC; the director either lies in the plane of incidence or is perpendicular to it. It is shown that, for the configurations considered, the maxima of the defect modes shift toward the short-wavelength region as the tilt angle of incidence radiation increases; this tendency is more manifest for the parallel-polarized component, when the director lies in the plane of incidence. In the latter case, the width of the photonic band gap (PBG) appreciably decreases. The temperature dependence of the polarization components of the transmission spectra of a PC is investigated in the case of normal incidence of light. The spectral shift of defect modes due to the variation of the refractive index of the LC at the nematic-isotropic liquid phase transition point is measured. It is shown that, in real PCs, the amplitude of defect modes decreases when approaching the center of the band gap, as well as when the number of layers in the dielectric mirrors increases. Theoretical transmission spectra of the PCs calculated by the method of recurrence relations with regard to the decay of defect modes are in good agreement with experimental data
Arkhipkin, V. G.; Gunyakov, V. A.; Myslivets, S. A.; Gerasimov, V. P.; Zyryanov, V. Ya.; Vetrov, S. Ya.; Shabanov, V. F.
2008-02-01
Transmission spectra of a one-dimensional photonic crystal (PC) formed by two multilayer dielectric mirrors and a planar oriented layer of 5CB nematic liquid crystal (LC) that is sandwiched between these mirrors and serves as a structure defect are investigated experimentally. Specific features of the behavior of the spectrum of defect modes as a function of the angle of incidence of light on the crystal are studied for two polarizations: parallel and perpendicular to the director of the LC; the director either lies in the plane of incidence or is perpendicular to it. It is shown that, for the configurations considered, the maxima of the defect modes shift toward the short-wavelength region as the tilt angle of incidence radiation increases; this tendency is more manifest for the parallel-polarized component, when the director lies in the plane of incidence. In the latter case, the width of the photonic band gap (PBG) appreciably decreases. The temperature dependence of the polarization components of the transmission spectra of a PC is investigated in the case of normal incidence of light. The spectral shift of defect modes due to the variation of the refractive index of the LC at the nematic-isotropic liquid phase transition point is measured. It is shown that, in real PCs, the amplitude of defect modes decreases when approaching the center of the band gap, as well as when the number of layers in the dielectric mirrors increases. Theoretical transmission spectra of the PCs calculated by the method of recurrence relations with regard to the decay of defect modes are in good agreement with experimental data.
Energy Technology Data Exchange (ETDEWEB)
Augieri, A [ENEA CR Frascati, Via E Fermi 45, 00044 Frascati, Rome (Italy); Celentano, G [ENEA CR Frascati, Via E Fermi 45, 00044 Frascati, Rome (Italy); Gambardella, U [INFN-LNF, Via Enrico Fermi 40, 00044 Frascati (Italy); Halbritter, J [Forschungszentrum Karlsruhe, IHM, Postfach 3640 76021 Karlsruhe (Germany); Petrisor, T [Technical University of Cluj, Str C. Daicoviciu 15, 3400 Cluj-Napoca (Romania)
2007-04-15
The critical current density J{sub c} as a function of the temperature T, magnetic field intensity H and angle {theta} between the direction of applied magnetic field and the c-axis of the samples was measured on epitaxial 10 at.% Ca-substituted YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YCBCO) thin films grown by the pulsed laser deposition technique on (001)-SrTiO{sub 3} (STO) and CeO{sub 2} buffered r-cut Al{sub 2}O{sub 3} (CAO) substrates. Films exhibited comparable values of critical temperature (T{sub c}{approx}78 K) while higher self-field J{sub c} values for SrTiO{sub 3} were observed. Dissipation regimes related to growth boundary and intra-grain pinning mechanisms showed a qualitatively similar contribution for YCBCO films deposited on both substrates when the applied magnetic field direction is parallel to the c-axis ({theta} = 0{sup 0}). However, a weaker efficiency of pinning related to growth boundaries as well as a wider field range where this dissipation mechanism is active were observed for films grown on CeO{sub 2}-buffered sapphire. These films exhibited a broad peak centred at {theta} = 0{sup 0} in the J{sub c} versus angle behaviour, not observed using a SrTiO{sub 3} substrate. The analysis of the J{sub c}(H) dependences collected at {theta} = 90{sup 0} revealed that this feature can be partially ascribed to a dramatic decrease of the intrinsic pinning efficiency.
Time-resolved orbital angular momentum spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Noyan, Mehmet A.; Kikkawa, James M. [Department of Physics and Astronomy, The University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)
2015-07-20
We introduce pump-probe magneto-orbital spectroscopy, wherein Laguerre-Gauss optical pump pulses impart orbital angular momentum to the electronic states of a material and subsequent dynamics are studied with 100 fs time resolution. The excitation uses vortex modes that distribute angular momentum over a macroscopic area determined by the spot size, and the optical probe studies the chiral imbalance of vortex modes reflected off the sample. First observations in bulk GaAs yield transients that evolve on time scales distinctly different from population and spin relaxation, as expected, but with surprisingly large lifetimes.
Time-resolved orbital angular momentum spectroscopy
International Nuclear Information System (INIS)
We introduce pump-probe magneto-orbital spectroscopy, wherein Laguerre-Gauss optical pump pulses impart orbital angular momentum to the electronic states of a material and subsequent dynamics are studied with 100 fs time resolution. The excitation uses vortex modes that distribute angular momentum over a macroscopic area determined by the spot size, and the optical probe studies the chiral imbalance of vortex modes reflected off the sample. First observations in bulk GaAs yield transients that evolve on time scales distinctly different from population and spin relaxation, as expected, but with surprisingly large lifetimes
Fourier relationship between angular position and optical orbital angular momentum
Yao, E.; Franke-Arnold, S.; Courtial, J.; Barnett, S.; Padgett, M. J.
2006-01-01
We demonstrate the Fourier relationship between angular position and angular momentum for a light mode. In particular we measure the distribution of orbital angular momentum states of light that has passed through an aperture and verify that the orbital angular momentum distribution is given by the complex Fourier-transform of the aperture function. We use spatial light modulators, configured as diffractive optical components, to define the initial orbital angular momentum state of the beam, ...
Fluidic angular velocity sensor
Berdahl, C. M. (Inventor)
1986-01-01
A fluidic sensor providing a differential pressure signal proportional to the angular velocity of a rotary input is described. In one embodiment the sensor includes a fluid pump having an impeller coupled to a rotary input. A housing forming a constricting fluid flow chamber is connected to the fluid input of the pump. The housing is provided with a fluid flow restrictive input to the flow chamber and a port communicating with the interior of the flow chamber. The differential pressure signal measured across the flow restrictive input is relatively noise free and proportional to the square of the angular velocity of the impeller. In an alternative embodiment, the flow chamber has a generally cylindrical configuration and plates having flow restrictive apertures are disposed within the chamber downstream from the housing port. In this embodiment, the differential pressure signal is found to be approximately linear with the angular velocity of the impeller.
Metamaterial broadband angular selectivity
Shen, Yichen; Ye, Dexin; Wang, Li; Celanovic, Ivan; Ran, Lixin; Joannopoulos, John D.; Soljačić, Marin
2014-09-01
We demonstrate how broadband angular selectivity can be achieved with stacks of one-dimensionally periodic photonic crystals, each consisting of alternating isotropic layers and effective anisotropic layers, where each effective anisotropic layer is constructed from a multilayered metamaterial. We show that by simply changing the structure of the metamaterials, the selective angle can be tuned to a broad range of angles; and, by increasing the number of stacks, the angular transmission window can be made as narrow as desired. As a proof of principle, we realize the idea experimentally in the microwave regime. The angular selectivity and tunability we report here can have various applications such as in directional control of electromagnetic emitters and detectors.
Metamaterial Broadband Angular Selectivity
Shen, Yichen; Wang, Zhiyu; Wang, Li; Celanovic, Ivan; Ran, Lixin; Joannopoulos, John D; Soljacic, Marin
2014-01-01
We demonstrate how broadband angular selectivity can be achieved with stacks of one-dimensionally periodic photonic crystals, each consisting of alternating isotropic layers and effective anisotropic layers, where each effective anisotropic layer is constructed from a multilayered metamaterial. We show that by simply changing the structure of the metamaterials, the selective angle can be tuned to a broad range of angles; and, by increasing the number of stacks, the angular transmission window can be made as narrow as desired. As a proof of principle, we realize the idea experimentally in the microwave regime. The angular selectivity and tunability we report here can have various applications such as in directional control of electromagnetic emitters and detectors.
Barron, S. C.; Patel, M. P.; Nguyen, Nam; Nguyen, N. V.; Green, M. L.
2015-11-01
A metrology and data analysis protocol is described for high throughput determination of thermochromic metal-insulator phase diagrams for lightly substituted VO2 thin films. The technique exploits the abrupt change in near infrared optical properties, measured in reflection, as an indicator of the temperature- or impurity-driven metal-insulator transition. Transition metal impurities were introduced in a complementary combinatorial synthesis process for producing thin film libraries with the general composition space V 1-x-yMxM'yO2, with M and M' being transition metals and x and y varying continuously across the library. The measurement apparatus acquires reflectance spectra in the visible or near infrared at arbitrarily many library locations, each with a unique film composition, at temperatures of 1 °C-85 °C. Data collection is rapid and automated; the measurement protocol is computer controlled to automate the collection of thousands of reflectance spectra, representing hundreds of film compositions at tens of different temperatures. A straightforward analysis algorithm is implemented to extract key information from the thousands of spectra such as near infrared thermochromic transition temperatures and regions of no thermochromic transition; similarly, reflectance to the visible spectrum generates key information for materials selection of smart window materials. The thermochromic transition for 160 unique compositions on a thin film library with the general formula V 1-x-yMxM'yO2 can be measured and described in a single 20 h experiment. The resulting impurity composition-temperature phase diagrams will contribute to the understanding of metal-insulator transitions in doped VO2 systems and to the development of thermochromic smart windows.
Dirac Green function for angular projection potentials.
Zeller, Rudolf
2015-11-25
The aim of this paper is twofold: first, it is shown that the angular dependence of the Dirac Green function can be described analytically for potentials with non-local dependence on the angular variables if they are chosen as projection potentials in angular momentum space. Because the local dependence on the radial variable can be treated to any precision with present computing capabilities, this means that the Green function can be calculated practically exactly. Second, it is shown that a result of this kind not only holds for a single angular projection potential but also more generally, for instance if space is divided into non-overlapping cells and a separate angular projection potential is used in each cell. This opens the way for relativistic density-functional calculations within a different perspective than the conventional one. Instead of trying to obtain the density for a given potential approximately as well as possible, the density is determined exactly for non-local potentials which can approximate arbitrary local potentials as well as desired. PMID:26523824
Dirac Green function for angular projection potentials
Zeller, Rudolf
2015-11-01
The aim of this paper is twofold: first, it is shown that the angular dependence of the Dirac Green function can be described analytically for potentials with non-local dependence on the angular variables if they are chosen as projection potentials in angular momentum space. Because the local dependence on the radial variable can be treated to any precision with present computing capabilities, this means that the Green function can be calculated practically exactly. Second, it is shown that a result of this kind not only holds for a single angular projection potential but also more generally, for instance if space is divided into non-overlapping cells and a separate angular projection potential is used in each cell. This opens the way for relativistic density-functional calculations within a different perspective than the conventional one. Instead of trying to obtain the density for a given potential approximately as well as possible, the density is determined exactly for non-local potentials which can approximate arbitrary local potentials as well as desired.
Essén, H
2003-01-01
This paper addresses the problem of the separation of rotational and internal motion. It introduces the concept of average angular velocity as the moment of inertia weighted average of particle angular velocities. It extends and elucidates the concept of Jellinek and Li (1989) of separation of the energy of overall rotation in an arbitrary (non-linear) $N$-particle system. It generalizes the so called Koenig's theorem on the two parts of the kinetic energy (center of mass plus internal) to three parts: center of mass, rotational, plus the remaining internal energy relative to an optimally translating and rotating frame.
Energy Technology Data Exchange (ETDEWEB)
Jankowiak, Martin; Larkoski, Andrew J.; /SLAC
2012-02-17
We introduce a jet shape observable defined for an ensemble of jets in terms of two-particle angular correlations and a resolution parameter R. This quantity is infrared and collinear safe and can be interpreted as a scaling exponent for the angular distribution of mass inside the jet. For small R it is close to the value 2 as a consequence of the approximately scale invariant QCD dynamics. For large R it is sensitive to non-perturbative effects. We describe the use of this correlation function for tests of QCD, for studying underlying event and pile-up effects, and for tuning Monte Carlo event generators.
Mahfouzi, Farzad; Nikolić, Branislav K.; Kioussis, Nicholas
2016-03-01
Motivated by recent experiments observing spin-orbit torque (SOT) acting on the magnetization m ⃗ of a ferromagnetic (F) overlayer on the surface of a three-dimensional topological insulator (TI), we investigate the origin of the SOT and the magnetization dynamics in such systems. We predict that lateral F/TI bilayers of finite length, sandwiched between two normal metal leads, will generate a large anti-damping-like SOT per very low charge current injected parallel to the interface. The large values of anti-damping-like SOT are spatially localized around the transverse edges of the F overlayer. Our analysis is based on adiabatic expansion (to first order in ∂ m ⃗/∂ t ) of time-dependent nonequilibrium Green functions (NEGFs), describing electrons pushed out of equilibrium both by the applied bias voltage and by the slow variation of a classical degree of freedom [such as m ⃗(t ) ]. From it we extract formulas for spin torque and charge pumping, which show that they are reciprocal effects to each other, as well as Gilbert damping in the presence of SO coupling. The NEGF-based formula for SOT naturally splits into four components, determined by their behavior (even or odd) under the time and bias voltage reversal. Their complex angular dependence is delineated and employed within Landau-Lifshitz-Gilbert simulations of magnetization dynamics in order to demonstrate capability of the predicted SOT to efficiently switch m ⃗ of a perpendicularly magnetized F overlayer.
Light with orbital angular momentum interacting with trapped ions
Schmiegelow, Christian Tomás; Schmidt-Kaler, Ferdinand
2011-01-01
We study the interaction of a light beams carrying angular momentum with a single, trapped and well localized ion. We provide a detailed calculation of selection rules and excitation probabilities for quadrupole transitions. The results show the dependencies on the angular momentum and polarization of the laser beam as well as the direction of the quantization magnetic field. In order to observe optimally the specific effects, focusing the angular momentum beam close to the diffraction limit ...
Indian Academy of Sciences (India)
Pradeep Kumar; Surajit Saha; C R Serrao; A K Sood; C N R Rao
2010-02-01
We have measured near normal incidence far-infrared (FIR) reflectivity spectra of a single crystal of TbMnO3 from 10 K to 300 K in the spectral range of 50 cm-1 –700 cm-1. Fifteen transverse optic (TO) and longitudinal optic (LO) modes are identified in the imaginary part of the dielectric function 2 ()$ and energy loss function Im(−1/()), respectively. Some of the observed phonon modes show anomalous softening below the magnetic transition temperature N (∼ 46 K). We attribute this anomalous softening to the spin-phonon coupling caused by phonon modulation of the superexchange integral between the Mn3+ spins. The effective charge of oxygen (O) calculated using the measured LO–TO splitting increases below N.
Reflecting Reflective Practice
Galea, Simone
2012-01-01
This paper demystifies reflective practice on teaching by focusing on the idea of reflection itself and how it has been conceived by two philosophers, Plato and Irigaray. It argues that reflective practice has become a standardized method of defining the teacher in teacher education and teacher accreditation systems. It explores how practices of…
Wigner Functions and Quark Orbital Angular Momentum
Mukherjee Asmita; Nair Sreeraj; Ojha Vikash Kumar
2014-01-01
Wigner distributions contain combined position and momentum space information of the quark distributions and are related to both generalized parton distributions (GPDs) and transverse momentum dependent parton distributions (TMDs). We report on a recent model calculation of the Wigner distributions for the quark and their relation to the orbital angular momentum.
Wigner Functions and Quark Orbital Angular Momentum
Directory of Open Access Journals (Sweden)
Mukherjee Asmita
2015-01-01
Full Text Available Wigner distributions contain combined position and momentum space information of the quark distributions and are related to both generalized parton distributions (GPDs and transverse momentum dependent parton distributions (TMDs. We report on a recent model calculation of the Wigner distributions for the quark and their relation to the orbital angular momentum.
Wang, Leiming; Lu, Hanbing; Brown, P Leon; Rea, William; Vaupel, Bruce; Yang, Yihong; Stein, Elliot; Shepard, Paul D.
2015-01-01
Manganese-enhanced magnetic resonance imaging (MEMRI) is a powerful technique for assessing the functional connectivity of neurons within the central nervous system. Despite the widely held proposition that MEMRI signal is dependent on neuronal activity, few studies have directly tested this implicit hypothesis. In the present series of experiments, MnCl2 was injected into the habenula of urethane-anesthetized rats alone or in combination with drugs known to alter neuronal activity by modulat...
Reflecting reflection in supervision
DEFF Research Database (Denmark)
Lystbæk, Christian Tang
Reflection has moved from the margins to the mainstream in supervision. Notions of reflection have become well established since the late 1980s. These notions have provided useful framing devices to help conceptualize some important processes in guidance and counseling. However, some applications...... previously associated with reflection and an exploration of alternative conceptions that view reflection within the context of settings which have a more group- and team-based orientation. Drawing on an action research project on health care supervision, the paper questions whether we should reject earlier...... views of reflection, rehabilitate them in order to capture broader connotations or move to new ways of regarding reflection that are more in keeping with not only reflective but also emotive, normative and formative views on supervision. The paper presents a critical perspective on supervision that...
Angular momentum transfer in deep inelastic scattering
International Nuclear Information System (INIS)
The measured γ-ray multiplicities as a function of exit channel kinetic energy and mass asymmetry for the reactions Au, Ho, Ag + 620 MeV Kr are compared with a diffusion calculation based exclusively upon particle transfer and which reproduces the Z distributions as well as the angular distributions as function of Z. The model correctly predicts the energy and Z dependence of the γ-ray multiplicities, thus lending support to the one-body model on one hand and to the angular-momentum fractionation along the mass asymmetry coordinate on the other
Evolution Equations for Higher Moments of Angular Momentum Distributions
Haegler, P.; Schaefer, A
1998-01-01
Based on a sumrule for the nucleon spin we expand quark and gluon orbital angular momentum operators and derive an evolution matrix for higher moments of the corresponding distributions. In combination with the spin-dependent DGLAP-matrix we find a complete set of spin and orbital angular momentum evolution equations.
On angular momentum transport in convection-dominated accretion flows
Igumenshchev, I V
2002-01-01
Convection-dominated accretion flow (CDAF) is a promising model to explain underluminous accreting black holes in X-ray binaries and galactic nuclei. I discuss effects of angular momentum transport in viscous hydrodynamical and MHD CDAFs. In hydrodynamical CDAFs, convection transports angular momentum inward, and this together with outward convection transport of thermal energy determine the radial structure of the flow. In MHD CDAFs, convection can transport angular momentum either inward or outward, depending on properties of turbulence in rotating magnetized plasma, which are not fully understood yet. Direction of convection angular momentum transport can affect the law of rotation of MHD CDAFs.
Angular Distribution and Angular Dispersion in Collision of 19F+27A1 at 114 MeV
Institute of Scientific and Technical Information of China (English)
WANG Qi; Li Zhi-Chang; LU Xiu-Qin; ZHAO Kui; LIU Jian-Cheng; SERGEY Yu-Kun; DONG Yu-Chuan; LI Song-Lin; DUAN Li-Min; XU Hu-Shan; XU Hua-Gen; CHEN Ruo-Fu; WU He-Yu; HAN Jian-Long
2004-01-01
Angular distributions of fragments B, C, N, O, F, Ne, Na, Mg and Al induced by the collision of 19F+27 A1 at 114MeV have been measured. Angular dispersion parameters are extracted from the experimental data and compared with the theoretical ones. The dynamic dispersions for dissipative products depend strongly on the charge number Z of the fragments.
An orbital angular momentum spectrometer for electrons
Harvey, Tyler; Grillo, Vincenzo; McMorran, Benjamin
2016-05-01
With the advent of techniques for preparation of free-electron and neutron orbital angular momentum (OAM) states, a basic follow-up question emerges: how do we measure the orbital angular momentum state distribution in matter waves? Control of both the energy and helicity of light has produced a range of spectroscopic applications, including molecular fingerprinting and magnetization mapping. Realization of an analogous dual energy-OAM spectroscopy with matter waves demands control of both initial and final energy and orbital angular momentum states: unlike for photons, final state post-selection is necessary for particles that cannot be annihilated. We propose a magnetic field-based mechanism for quantum non-demolition measurement of electron OAM. We show that OAM-dependent lensing is produced by an operator of form U =exp iLzρ2/ℏb2 where ρ =√{x2 +y2 } is the radial position operator, Lz is the orbital angular momentum operator along z, and b is the OAM dispersion length. We can physically realize this operator as a term in the time evolution of an electron in magnetic round lens. We discuss prospects and practical challenges for implementation of a lensing orbital angular momentum measurement. This work was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under the Early Career Research Program Award # DE-SC0010466.
Reflecting on Cherenkov reflections
Fargion, D.; Gaug, M.; Oliva, P.
2007-01-01
Magic Telescope may observe and reveal at horizons lights from air-shower Cherenkov reflections. The ground, the sea, the cloudy sky (below the mountain) may reflect PeVs-EeV UHECR Cherenkov lights observable by MAGIC telescopes. Even rarest UHE neutrino skimming the atmosphere or skimming the Earth may induce upward-horizontal airshowers: a new Neutrino Astronomy. These fluorescence signals or the Cherenkov reflections in upper cloudy sky may flash in correlated BL-Lac or GRB shining at oppo...
Quark Orbital Angular Momentum
Burkardt, Matthias
2016-06-01
Generalized parton distributions provide information on the distribution of quarks in impact parameter space. For transversely polarized nucleons, these impact parameter distributions are transversely distorted and this deviation from axial symmetry leads on average to a net transverse force from the spectators on the active quark in a DIS experiment. This force when acting along the whole trajectory of the active quark leads to transverse single-spin asymmetries. For a longitudinally polarized nucleon target, the transverse force implies a torque acting on the quark orbital angular momentum (OAM). The resulting change in OAM as the quark leaves the target equals the difference between the Jaffe-Manohar and Ji OAMs.
Quark Orbital Angular Momentum
Burkardt, Matthias
2016-03-01
Generalized parton distributions provide information on the distribution of quarks in impact parameter space. For transversely polarized nucleons, these impact parameter distributions are transversely distorted and this deviation from axial symmetry leads on average to a net transverse force from the spectators on the active quark in a DIS experiment. This force when acting along the whole trajectory of the active quark leads to transverse single-spin asymmetries. For a longitudinally polarized nucleon target, the transverse force implies a torque acting on the quark orbital angular momentum (OAM). The resulting change in OAM as the quark leaves the target equals the difference between the Jaffe-Manohar and Ji OAMs.
Vanston, Alex
2013-01-01
This book uses a practical, step-by-step approach, starting with how to build directives from the ground up before moving on to creating web applications comprised of multiple modules all working together to provide the best user experience possible.This book is intended for intermediate JavaScript developers who are looking to enhance their understanding of single-page web application development with a focus on AngularJS and the JavaScript MVC frameworks.It is expected that readers will understand basic JavaScript patterns and idioms and can recognize JSON formatted data.
Asymmetry in the angular distributions of spectator-nucleons
International Nuclear Information System (INIS)
The asymmetry in the angular distributions of spectator-nucleons has been studied in dp interactions, and it has been found that the sign of the asymmetry depends on the reaction channel. It is shown that in the momentum interval 0-200 MeV/c of spectators basic features of the angular distributions can be reproduced in the framework of the spectator model taking into account the energy dependence of the NN cross section and the flux-factor
Quark Wigner distributions and orbital angular momentum
International Nuclear Information System (INIS)
We study the Wigner functions of the nucleon which provide multidimensional images of the quark distributions in phase space. These functions can be obtained through a Fourier transform in the transverse space of the generalized transverse-momentum dependent parton distributions. They depend on both the transverse position and the three-momentum of the quark relative to the nucleon, and therefore combine in a single picture all the information contained in the generalized parton distributions and the transverse-momentum dependent parton distributions. We focus the discussion on the distributions of unpolarized/longitudinally polarized quark in an unpolarized/longitudinally polarized nucleon. In this way, we can study the role of the orbital angular momentum of the quark in shaping the nucleon and its correlations with the quark and nucleon polarizations. The quark orbital angular momentum is also calculated from its phase-space average weighted with the Wigner distribution of unpolarized quarks in a longitudinally polarized nucleon. The corresponding results obtained within different light-cone quark models are compared with alternative definitions of the quark orbital angular momentum, as given in terms of generalized parton distributions and transverse-momentum dependent parton distributions.
A Language Model Reflecting Long Distance Dependency Relation%一种体现长距离依赖关系的语言模型
Institute of Scientific and Technical Information of China (English)
李春生
2014-01-01
The N-gram language model which can capture local dependency relationship between words, is widely used in speech recognition, machine translation and some other fields of nature language process, but there is still the limitation in capturing long distance relations. A dependency syntax tree can reflect semantic relation between the components of a sentence which means it can model the long distance collocations explicitly. Based on the max entropy method, the paper constructs a new language model which can capture the long distance dependency relation between words.%基于N-gram的语言模型广泛应用于语音识别、机器翻译等众多自然语言处理相关领域，捕获的主要是词之间的局部依赖关系，但其本身存在一定的局限性。依存句法树能够反映出句子中各成分之间的语义修饰关系，显式地对词之间的长距离搭配关系进行建模。本文利用最大熵方法整合句子的局部依赖关系和长距离搭配关系，构建一种包含长距离依赖关系的语言模型。
Satoh, N.; Fukuda, H.; Miyairi, Y.; Yokoyama, Y.; Nagata, T.
2015-12-01
Radiocarbon in dissolved inorganic carbon (DIC) in seawater varies greatly, both geographically and with depth. This "reservoir effect" is thought to be reflected in the radiocarbon content (∆14C) of marine organisms, via DIC fixation by primary producers and subsequent trophic transfer. The ∆14C of marine organismal soft tissues might thus provide unique information about their habitats, diets, migration and other environmental histories. However, the effectiveness of this approach has yet to be extensively explored, with data on ∆14C variability in soft tissues of marine organisms being markedly limited. Here we examined whether ∆14C values of individual pinnate blades (leaf-like structures) of brown seaweed (Undaria pinnatifida) reflect the ∆14C of DIC in the water current prevailing at the time of blade formation. The study was conducted in Otsuchi Bay located in the Sanriku coastal region, northeastern Japan, where 14C-depleted cold Oyashio current and warm Tsugaru current (high ∆14C) converge, affecting the physiology and growth of marine organisms growing there. U. pinnatifida individuals cultured in the bay (length of saprophytes, 140-215 cm) were harvested in April 2014 and ∆14C of blades were determined by accelerator mass spectrometry. Younger blades formed after the Oyashio water intrusion had significantly lower ∆14C values compared to older blades formed before the event. The ∆14C values of younger and older blades were generally consistent with the ∆14C of DIC in Oyashio (-60.5 ‰) and Tsugaru (24.9 ‰) waters, respectively. Thus, despite possible turnover of organic carbon in seaweed soft tissues, blade-order-dependent ∆14C variability appeared to strongly reflect the Oyashio intrusion event (radiocarbon shift) in the bay.
Bai, Long; Zhang, Rong; Duan, Chen-Long
2012-01-01
: Using the nonequilibrium Green's function method, we theoretically study the Andreev reflection(AR) in a four-terminal Aharonov-Bohm interferometer containing a coupled double quantum dot with the Rashba spin-orbit interaction (RSOI) and the coherent indirect coupling via two ferromagnetic leads. When two ferromagnetic electrodes are in the parallel configuration, the spin-up conductance is equal to the spin-down conductance due to the absence of the RSOI. However, for the antiparallel alignment, the spin-polarized AR occurs resulting from the crossed AR (CAR) and the RSOI. The effects of the coherent indirect coupling, RSOI, and magnetic flux on the Andreev-reflected tunneling magnetoresistance are analyzed at length. The spin-related current is calculated, and a distinct swap effect emerges. Furthermore, the pure spin current can be generated due to the CAR when two ferromagnets become two half metals. It is found that the strong RSOI and the large indirect coupling are in favor of the CAR and the production of the strong spin current. The properties of the spin-related current are tunable in terms of the external parameters. Our results offer new ways to manipulate the spin-dependent transport. PMID:23228047
Energy Technology Data Exchange (ETDEWEB)
Watanabe, Yoshihide, E-mail: e0827@mosk.tytlabs.co.jp; Nishimura, Yusaku F.; Suzuki, Ryo; Beniya, Atsushi; Isomura, Noritake [Toyota Central R& D Labs., Inc., Yokomichi 41-1, Nagakute, Aichi 480-1192 (Japan); Uehara, Hiromitsu; Asakura, Kiyotaka; Takakusagi, Satoru [Catalysis Research Center, Hokkaido University, Kita 21-10, Sapporo, Hokkaido 001-0021 (Japan); Nimura, Tomoyuki [AVC Co., Ltd., Inada 1450-6, Hitachinaka, Ibaraki 312-0061 (Japan)
2016-03-15
A portable ultrahigh-vacuum sample storage system was designed and built to investigate the detailed geometric structures of mass-selected metal clusters on oxide substrates by polarization-dependent total-reflection fluorescence x-ray absorption fine structure spectroscopy (PTRF-XAFS). This ultrahigh-vacuum (UHV) sample storage system provides the handover of samples between two different sample manipulating systems. The sample storage system is adaptable for public transportation, facilitating experiments using air-sensitive samples in synchrotron radiation or other quantum beam facilities. The samples were transferred by the developed portable UHV transfer system via a public transportation at a distance over 400 km. The performance of the transfer system was demonstrated by a successful PTRF-XAFS study of Pt{sub 4} clusters deposited on a TiO{sub 2}(110) surface.
International Nuclear Information System (INIS)
A portable ultrahigh-vacuum sample storage system was designed and built to investigate the detailed geometric structures of mass-selected metal clusters on oxide substrates by polarization-dependent total-reflection fluorescence x-ray absorption fine structure spectroscopy (PTRF-XAFS). This ultrahigh-vacuum (UHV) sample storage system provides the handover of samples between two different sample manipulating systems. The sample storage system is adaptable for public transportation, facilitating experiments using air-sensitive samples in synchrotron radiation or other quantum beam facilities. The samples were transferred by the developed portable UHV transfer system via a public transportation at a distance over 400 km. The performance of the transfer system was demonstrated by a successful PTRF-XAFS study of Pt4 clusters deposited on a TiO2(110) surface
Orbital angular momentum microlaser
Miao, Pei; Zhang, Zhifeng; Sun, Jingbo; Walasik, Wiktor; Longhi, Stefano; Litchinitser, Natalia M.; Feng, Liang
2016-07-01
Structured light provides an additional degree of freedom for modern optics and practical applications. The effective generation of orbital angular momentum (OAM) lasing, especially at a micro- and nanoscale, could address the growing demand for information capacity. By exploiting the emerging non-Hermitian photonics design at an exceptional point, we demonstrate a microring laser producing a single-mode OAM vortex lasing with the ability to precisely define the topological charge of the OAM mode. The polarization associated with OAM lasing can be further manipulated on demand, creating a radially polarized vortex emission. Our OAM microlaser could find applications in the next generation of integrated optoelectronic devices for optical communications in both quantum and classical regimes.
Orbital angular momentum microlaser.
Miao, Pei; Zhang, Zhifeng; Sun, Jingbo; Walasik, Wiktor; Longhi, Stefano; Litchinitser, Natalia M; Feng, Liang
2016-07-29
Structured light provides an additional degree of freedom for modern optics and practical applications. The effective generation of orbital angular momentum (OAM) lasing, especially at a micro- and nanoscale, could address the growing demand for information capacity. By exploiting the emerging non-Hermitian photonics design at an exceptional point, we demonstrate a microring laser producing a single-mode OAM vortex lasing with the ability to precisely define the topological charge of the OAM mode. The polarization associated with OAM lasing can be further manipulated on demand, creating a radially polarized vortex emission. Our OAM microlaser could find applications in the next generation of integrated optoelectronic devices for optical communications in both quantum and classical regimes. PMID:27471299
Jet angular distribution from quantum chromodynamics
International Nuclear Information System (INIS)
The quantum chromodynamic correction to jet (defined a la Sterman and Weinberg) angular distribution in energetic e+e- annihilation is calculated to order α/sub s/ keeping exact dependence on epsilon and delta. Deviations from the zeroth order distribution, 1 + cos2theta, for are found relatively large values of epsilon and delta. This effect could be tested at the existing e+e- colliding beam facilities
Wigner distributions and quark orbital angular momentum
Cedric LorceOrsay, IPN and Orsay, LPT; Barbara Pasquini(Pavia U. and INFN, Pavia)
2015-01-01
We discuss the quark phase-space or Wigner distributions of the nucleon which combine in a single picture all the information contained in the generalized parton distributions and the transverse-momentum dependent parton distributions. In particular, we present results for the distribution of unpolarized quarks in a longitudinally polarized nucleon obtained in a light-front constituent quark model. We show how the quark orbital angular momentum can be extracted from the Wigner distributions a...
Angular Diameter Distances in Clumpy Friedmann Universes
Tomita, Kenji
1998-01-01
Solving null-geodesic equations, behavior of angular diameter distances is studied in inhomogeneous cosmological models, which are given by performing N-body simulations with the CDM spectrum. The distances depend on the separation angle of ray pairs, the mass and the radius of particles cosisting of galaxies and dark matter balls, and cosmological model parameters. The calculated distances are compared with the Dyer- Roeder distance, and after many ray-shooting, the average, dispersion and d...
γ - γ Angular Correlation Measurements With GRIFFIN
Maclean, Andrew; Griffin Collaboration
2015-10-01
When an excited nuclear state emits successive γ-rays causing a γ - γ cascade an anisotropy is found in the spatial distribution of γ2 with respect to γ1. Defining the direction of γ1 as the z-axis, the intermediate level, in general will have an uneven distribution of m-states. This causes an anisotropy in the angular correlation of the second γ-ray with respect to the first. These angular correlations are expressed by the W (θ) that depends on numerical coefficients described by the sequence of spin-parity values for the nuclear states involved, the multipolarities and mixing ratios. Angular correlations can be used for the assignment of spins and parities for the nuclear states, and thus provide a powerful means to elucidate the structure of nuclei far from stability through β - γ - γ coincidence measurements. In order to explore the sensitivity of the new 16 clover-detector GRIFFIN γ-ray spectrometer at TRIUMF-ISAC to such γ - γ angular correlations, and to optimize its performance for these measurements we have studied a well known γ - γ cascade from 60Co decay through both experimental measurements and Geant4 simulation. Results will be shown in this talk. Work supported by the Canada Foundation for Innovation, the Natural Sciences and Engineering Research Council of Canada and the National Research Council of Canada.
Novel Method to Evaluate Angular Stiffness of Prosthetic Feet From Linear Compression Tests
Adamczyk, Peter G.; Roland, Michelle; Hahn, Michael E.
2013-01-01
Lower limb amputee gait during stance phase is related to the angular stiffness of the prosthetic foot, which describes the dependence of ankle torque on angular progression of the shank. However, there is little data on angular stiffness of prosthetic feet, and no method to directly measure it has been described. The objective of this study was to derive and evaluate a method to estimate the angular stiffness of prosthetic feet using a simple linear compression test. Linear vertical compress...
Farrell, Thomas S. C.
2013-01-01
Thomas Farrell's "Reflective Teaching" outlines four principles that take teachers from just doing reflection to making it a way of being. Using the four principles, Reflective Practice Is Evidence Based, Reflective Practice Involves Dialogue, Reflective Practice Links Beliefs and Practices, and Reflective Practice Is a Way of Life,…
Li, Panyun; Zhang, Kai; Bao, Yuan; Ren, Yuqi; Ju, Zaiqiang; Wang, Yan; He, Qili; Zhu, Zhongzhu; Huang, Wanxia; Yuan, Qingxi; Zhu, Peiping
2016-03-21
Microscopy techniques using visible photons, x-rays, neutrons, and electrons have made remarkable impact in many scientific disciplines. The microscopic data can often be expressed as the convolution of the spatial distribution of certain properties of the specimens and the inherent response function of the imaging system. The x-ray grating interferometer (XGI), which is sensitive to the deviation angle of the incoming x-rays, has attracted significant attention in the past years due to its capability in achieving x-ray phase contrast imaging with low brilliance source. However, the comprehensive and analytical theoretical framework is yet to be presented. Herein, we propose a theoretical framework termed angular signal radiography (ASR) to describe the imaging process of the XGI system in a classical, comprehensive and analytical manner. We demonstrated, by means of theoretical deduction and synchrotron based experiments, that the spatial distribution of specimens' physical properties, including absorption, refraction and scattering, can be extracted by ASR in XGI. Implementation of ASR in XGI offers advantages such as simplified phase retrieval algorithm, reduced overall radiation dose, and improved image acquisition speed. These advantages, as well as the limitations of the proposed method, are systematically investigated in this paper. PMID:27136780
A New Open-Loop Fiber Optic Gyro Error Compensation Method Based on Angular Velocity Error Modeling
Yanshun Zhang; Yajing Guo; Chunyu Li; Yixin Wang; Zhanqing Wang
2015-01-01
With the open-loop fiber optic gyro (OFOG) model, output voltage and angular velocity can effectively compensate OFOG errors. However, the model cannot reflect the characteristics of OFOG errors well when it comes to pretty large dynamic angular velocities. This paper puts forward a modeling scheme with OFOG output voltage and temperature as the input variables and angular velocity error as the output variable. Firstly, the angular ve...
The pretzelosity TMD and quark orbital angular momentum
Energy Technology Data Exchange (ETDEWEB)
Lorce, C. [IPNO, Universite Paris-Sud, CNRS/IN2P3, 91406 Orsay (France); LPT, Universite Paris-Sud, CNRS, 91406 Orsay (France); Pasquini, B., E-mail: pasquini@pv.infn.it [Dipartimento di Fisica, Universita degli Studi di Pavia, Pavia (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Pavia, Pavia (Italy)
2012-04-12
We study the connection between the quark orbital angular momentum and the pretzelosity transverse-momentum dependent parton distribution function. We discuss the origin of this relation in quark models, identifying as key ingredient for its validity the assumption of spherical symmetry for the nucleon in its rest frame. Finally we show that the individual quark contributions to the orbital angular momentum obtained from this relation cannot be interpreted as the intrinsic contributions, but include the contribution from the transverse centre of momentum which cancels out only in the total orbital angular momentum.
Angular resolution of air-shower array-telescopes
Linsley, J.
1985-01-01
A fundamental limit on the angular resolution of air shower array-telescopes is set by the finite number of shower particles coupled with the finite thickness of the particle swarm. Consequently the angular resolution which can be achieved in practice depends in a determinant manner on the size and number of detectors in an array-telescope, as well as on the detector separation and the timing resolution. It is also necessary to examine the meaning of particle density in whatever type of detector is used. Results are given which can be used to predict the angular resolution of a given instrument for showers of various sizes, and to compare different instruments.
The pretzelosity TMD and quark orbital angular momentum
International Nuclear Information System (INIS)
We study the connection between the quark orbital angular momentum and the pretzelosity transverse-momentum dependent parton distribution function. We discuss the origin of this relation in quark models, identifying as key ingredient for its validity the assumption of spherical symmetry for the nucleon in its rest frame. Finally we show that the individual quark contributions to the orbital angular momentum obtained from this relation cannot be interpreted as the intrinsic contributions, but include the contribution from the transverse centre of momentum which cancels out only in the total orbital angular momentum.
Control of Angular Intervals for Angle-Multiplexed Holographic Memory
Kinoshita, Nobuhiro; Muroi, Tetsuhiko; Ishii, Norihiko; Kamijo, Koji; Shimidzu, Naoki
2009-03-01
In angle-multiplexed holographic memory, the full width at half maximum of the Bragg selectivity curves is dependent on the angle formed between the medium and incident laser beams. This indicates the possibility of high density and high multiplexing number by varying the angular intervals between adjacent holograms. We propose an angular interval scheduling for closely stacking holograms into medium even when the angle range is limited. We obtained bit error rates of the order of 10-4 under the following conditions: medium thickness of 1 mm, laser beam wavelength of 532 nm, and angular multiplexing number of 300.
Two-color ghost imaging with enhanced angular resolving power
International Nuclear Information System (INIS)
This article reports an experimental demonstration on nondegenerate, two-color, biphoton ghost imaging which reproduced a ghost image with enhanced angular resolving power by means of a greater field of view compared with that of classical imaging. With the same imaging magnification, the enhanced angular resolving power and field of view compared with those of classical imaging are 1.25:1 and 1.16:1, respectively. The enhancement of angular resolving power depends on the ratio between the idler and the signal photon frequencies, and the enhancement of the field of view depends mainly on the same ratio and also on the distances of the object plane and the imaging lens from the two-photon source. This article also reports the possibility of reproducing a ghost image with the enhancement of the angular resolving power by means of a greater imaging amplification compared with that of classical imaging.
Self-sputtering and reflection
International Nuclear Information System (INIS)
Self-sputtering and reflection are investigated with the Monte Carlo program TRIMSP. The results include particle and energy reflection coefficients, sputtering yields and sputtered energy versus incident angle and energy. Angular and energy distributions of reflected and sputtered particles are also given. Reflection and sputtering values are compared to show their contributions to selfsputtering. A comparison of calculated sputtering yields and sputtering efficiencies (sputtering energy) with experimental data is carried out. The systems investigated are mainly the bombardment of C, Ni, and W with self-ions. (orig.)
Quark Orbital Angular Momentum and Exclusive Processes at HERMES
International Nuclear Information System (INIS)
A first attempt for a model-dependent extraction of the orbital angular momentum of quarks in the nucleon has been made, based on HERMES data on exclusive processes and their description in terms of generalized parton distributions. An overview of the HERMES data on hard exclusive electroproduction of real photons (Deeply-Virtual Compton Scattering) and mesons is given, focusing on the measurements relevant to the extraction of quark orbital angular momentum
Quark Orbital Angular Momentum and Exclusive Processes at HERMES
Ellinghaus, F.
2006-11-01
A first attempt for a model-dependent extraction of the orbital angular momentum of quarks in the nucleon has been made, based on HERMES data on exclusive processes and their description in terms of generalized parton distributions. An overview of the HERMES data on hard exclusive electroproduction of real photons (Deeply-Virtual Compton Scattering) and mesons is given, focusing on the measurements relevant to the extraction of quark orbital angular momentum.
Reflectance measurements from particulate surfaces
Peltoniemi, J.; Gritsevich, M.; Hakala, T.; Penttilä, A.; Eskelinen, J.; Dagsson-Waldhauserova, P.; Arnalds, O.; Guirado, D.; Muinonen, K.
2014-07-01
Asteroids consists of, e.g., metals and rocky materials, and comets consist of, e.g., icy and rocky materials and dust. Their surfaces can be covered by small particles. To certain extent, these surfaces can resemble some natural or artificial surfaces on the Earth, such as snow layers, sand, gravels, or silt. By measuring the reflectance from such surfaces, one can gain better understanding on how to interpret astronomical observations of asteroids and comets. Even if not completely analogous, these samples and measurements provide a strict test bed for the scattering models applied to interpret observations of small Solar System bodies. FIGIFIGO (Finnish Geodetic Institute's Field Gonio-spectro-polari- radiometer) can measure the bidirectional reflectance factor (BRF) of surface targets of a diameter of around 10 cm, in a selected angular range and resolution, in the spectral range of 400-2400 nm, at about 10-nm resolution, including linear polarisation (Stokes I, Q, and U, or reflection coefficient matrix elements R_{11}, R_{12}, and R_{13}). Using FIGIFIGO, over 500 samples have been measured over the past years, including over 100 snow samples and almost 100 samples resembling sand, silt, soil, dust, or gravel. For planetary studies, especially interesting are dark volcanic ash and silt samples from Eyjafjallajökull and Grímsvönt eruptions. These have been measured loose and compressed, smooth and rough, purely and deposited on snow. Further single-scattering measurements using the Granada setup and measurements using the Univ. Helsinki integrating sphere complement the picture. Generally, we have observed that the reflectance from volcanic materials behaves mostly as expected and modelled. BRF shows typical bowl shape with strong phase-angle dependence. Spectral features are smooth, with slight angular dependence. Polarisation depends strongly on the phase angle, weaker on other angles defining the scattering geometry, and smoothly on the wavelength. There
Bailey, Simon
2015-01-01
This book is intended for developers who have an understanding of the basic principles behind both AngularJS and test-driven development. You, as a developer, are interested in eliminating the fear related to either introducing tests to an existing codebase or starting out testing on a fresh AngularJS application. If you're a team leader or part of a QA team with the responsibility of ensuring full test coverage of an application, then this book is ideal for you to comprehend the full testing scope required by your developers. Whether you're new to or are well versed with AngularJS, this book
Orbit-orbit interaction and photonic orbital Hall effect in reflection of a light beam
International Nuclear Information System (INIS)
We examine the orbit—orbit interaction when a paraxial beam with intrinsic orbital angular momentum (IOAM) reflects at an air—glass interface. The orbital-dependent splitting of the beam intensity distribution arises due to the interaction between IOAM and extrinsic orbital angular momentum (EOAM). In addition, we find that the beam centroid shows an orbital-dependent rotation when seen along the propagation axis. However, the motion of the beam centroid related to the orbit—orbit interaction undergoes a straight line trajectory with a small angle inclining from the propagation axis. Similar to a previously developed spin-dependent splitting in the photonic spin Hall effect, the orbital-dependent splitting could lead to the photonic orbital Hall effect
Reflection, Reflective Practice and Embodied Reflective Practice
Leigh, Jennifer S; Bailey, Richard
2013-01-01
Although widely employed in professional practice of all kinds, ‘reflection’ and ‘reflective practice’ can be considered ‘success words’. That is, they elicit positive and supportive responses and yet the concepts are vague, ill-defined, contradictory and reflective skills can be hard to teach. Using examples from education and somatic movement therapy, we argue that a purely analytical approach to reflective practice that involves reflecting on thoughts alone is likely to lead into a negativ...
The integration of angular velocity
Boyle, Michael
2016-01-01
A common problem in physics and engineering is determination of the orientation of an object given its angular velocity. When the direction of the angular velocity changes in time, this is a nontrivial problem involving coupled differential equations. Several possible approaches are examined, along with various improvements over previous efforts. These are then evaluated numerically by comparison to a complicated but analytically known rotation that is motivated by the important astrophysical...
MBL Experiment in Angular Momentum
Gluck, Paul
2002-04-01
Among the series of beautiful take-home experiments designed by A.P. French and J.G. King for MIT students, the one on angular momentum studies the loss and conservation of angular momentum using a small dc motor as generator. Here we describe a version of the experiment that increases its accuracy, enables students to perform detailed rotational dynamics calculations, and sharpens the ability to isolate the region where the collision occurs.
Greenslade, Thomas B., Jr.
1994-01-01
Discusses and provides an example of reflectivity approximation to determine whether reflection will occur. Provides a method to show thin-film interference on a projection screen. Also applies the reflectivity concepts to electromagnetic wave systems. (MVL)
Orbital angular momentum of the laser beam and the second order intensity moments
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
From the wave equation of a generalized beam the orbital angular momentum is studied. It is shown that the orbital angular momentum exists not only in the Laguerre_Gaussian beam,but in any beam with an angular_dependent structure. By calculating the second order intensity moments of the beam the relation between the orbital angular momentum and the second order moments 〈xθy〉, 〈yθx〉 is given. As an example the orbital angular momentum of the general astigmatic Gaussian beam is studied.
Orbital angular momentum of the laser beam and the second order intensity moments
Institute of Scientific and Technical Information of China (English)
高春清[1; 魏光辉[2; HorstWeber[3
2000-01-01
From the wave equation of a generalized beam the orbital angular momentum is studied. It is shown that the orbital angular momentum exists not only in the Laguerre-Gaussian beam, but in any beam with an angular-dependent structure. By calculating the second order intensity moments of the beam the relation between the orbital angular momentum and the second order moments 〈xθy〉, 〈yθx〉 is given. As an example the orbital angular momentum of the general astigmatic Gaussian beam is studied.
Interpretation of angular distributions of Z-boson production at colliders
Directory of Open Access Journals (Sweden)
Jen-Chieh Peng
2016-07-01
Full Text Available High precision data of dilepton angular distributions in γ⁎/Z production were reported recently by the CMS Collaboration covering a broad range of the dilepton transverse momentum, qT, up to ∼300 GeV. Pronounced qT dependencies of the λ and ν parameters, characterizing the cos2θ and cos2ϕ angular distributions, were found. Violation of the Lam–Tung relation was also clearly observed. We show that the qT dependence of λ allows a determination of the relative contributions of the qq¯ annihilation versus the qG Compton process. The violation of the Lam–Tung relation is attributed to the presence of a non-zero component of the q−q¯ axis in the direction normal to the “hadron plane” formed by the colliding hadrons. The magnitude of the violation of the Lam–Tung relation is shown to reflect the amount of this ‘non-coplanarity”. The observed qT dependencies of λ and ν from the CMS and the earlier CDF data can be well described using this approach.
The evolution of black-hole mass and angular momentum
King, A R
1999-01-01
We show that neither accretion nor angular momentum extraction are likely to lead to significant changes in the mass M_1 or angular momentum parameter a_* of a black hole in a binary system with realistic parameters. Current values of M_1 and a_* therefore probably reflect those at formation. We show further that sufficiently energetic jet ejection powered by the black hole's rotational energy can stabilize mass transfer in systems with large adverse mass ratios, and even reduce the mass transfer rate to the point where the binary becomes transient.
Evers, N M; van de Klundert, T M C; van Aesch, Y M; Wang, S; de Roos, W K; Romano, A; de Haan, L H J; Murk, A J; Ederveen, A G H; Rietjens, I M C M; Groten, J P
2013-09-01
T47D-ERβ breast cancer cells with tetracycline-dependent ERβ expression and constant ERα expression can be used to investigate effects of varying ERα/ERβ ratios on estrogen-induced cellular responses. This study defines conditions at which ERα/ERβ ratios in T47D-ERβ cells best mimic ERα/ERβ ratios in breast and other estrogen-sensitive tissues in vivo in rat as well as in human. Protein and mRNA levels of ERα and ERβ were analyzed in T47D-ERβ cells exposed to a range of tetracycline concentrations and compared to ERα and ERβ levels found in breast, prostate, and uterus from rat and human origin. The ERα/ERβ ratio in T47D-ERβ cells exposed to >150ng/ml tetracycline is comparable to the ratio found in rat mammary gland and in human breast tissue. The ERα/ERβ ratio of other estrogen-sensitive rat and human tissues can also be mimicked in T47D-ERβ cells. The ERα/ERβ ratio found in MCF-7 and native T47D breast cancer cell lines did not reflect ratios in analyzed rat and human tissues, which further supports the use of T47D-ERβ cells as model for estrogen-responsive tissues. Using 17β-estradiol and the T47D-ERβ cells under the conditions defined to mimic various tissues it could be demonstrated how these different tissues vary in their proliferative response. PMID:23680332
International Nuclear Information System (INIS)
The aim of this study is to measure the angular momentum transferred to the target-like product, in the Kr + U reaction at 35 A.MeV, as a function of the excitation energy. The measured neutron multiplicity, as seen by the detector ORION, was used as the basic event selection criterion. This multiplicity also allows an estimation of the excitation energy transferred to the target-like product on an event by event basis. The study of the behaviour of the projectile-like component allows one to characterize two-body mechanisms, which are associated with a large energy dissipation for less peripheral collisions. The spin transferred to the target-like component is deduced from the out-plane angular distributions of the fission fragments. The study of the angular correlation between these fission fragments confirms that the dominant mechanism is essentially a two-body process. We show that the angular momentum values obtained, as a function of the excitation energy of the target-like product, have little dependence on the time taken for the nucleus to reach the saddle point. We observe a constant increase in the target-like component's spin, varying from 15ℎ to 60ℎ, as the excitation energy increases from roughly 8 to 400 MeV. For the higher excitation energies the spin does not increase. This behaviour reflects the vanishing binary fission mechanism at high angular momenta. (author)
Stellar Diameters and Temperatures IV. Predicting Stellar Angular Diameters
Boyajian, Tabetha; von Braun, Kaspar
2013-01-01
The number of stellar angular diameter measurements has greatly increased over the past few years due to innovations and developments in the field of long baseline optical interferometry (LBOI). We use a collection of high-precision angular diameter measurements for nearby, main-sequence stars to develop empirical relations that allow the prediction of stellar angular sizes as a function of observed photometric color. These relations are presented for a combination of 48 broad-band color indices. We empirically show for the first time a dependence on metallicity to these relations using Johnson $(B-V)$ and Sloan $(g-r)$ colors. Our relations are capable of predicting diameters with a random error of less than 5% and represent the most robust and empirical determinations to stellar angular sizes to date.
Portable device for characterizing the angular response of UV spectroradiometers
International Nuclear Information System (INIS)
This paper introduces a device that was developed to measure the angular response of UV spectroradiometers in the field. This device is designed to be used at the operating position of spectroradiometers; thus the derived angular response also includes any effects from imperfect leveling of the diffuser and corresponds to the actual operational angular response. The design and characterization of the device and the results from its application on 11 different spectroradiometers that operate at different European UV stations are presented. Various sources of uncertainties that were identified result in a combined uncertainty in determining the angular response, which ranges between approximately 1.5% and 10%, depending on the incidence angle and the characteristics of the diffuser. For the 11 instruments, the error in reporting the diffuse irradiance ranges between 2% and -13%, assuming isotropic distribution of the downwelling radiances
Quantum optimal control of photoelectron spectra and angular distributions
Goetz, R Esteban; Santra, Robin; Koch, Christiane P
2016-01-01
Photoelectron spectra and photoelectron angular distributions obtained in photoionization reveal important information on e.g. charge transfer or hole coherence in the parent ion. Here we show that optimal control of the underlying quantum dynamics can be used to enhance desired features in the photoelectron spectra and angular distributions. To this end, we combine Krotov's method for optimal control theory with the time-dependent configuration interaction singles formalism and a splitting approach to calculate photoelectron spectra and angular distributions. The optimization target can account for specific desired properties in the photoelectron angular distribution alone, in the photoelectron spectrum, or in both. We demonstrate the method for hydrogen and then apply it to argon under strong XUV radiation, maximizing the difference of emission into the upper and lower hemispheres, in order to realize directed electron emission in the XUV regime.
Quantum optimal control of photoelectron spectra and angular distributions
Goetz, R. Esteban; Karamatskou, Antonia; Santra, Robin; Koch, Christiane P.
2016-01-01
Photoelectron spectra and photoelectron angular distributions obtained in photoionization reveal important information on, e.g., charge transfer or hole coherence in the parent ion. Here we show that optimal control of the underlying quantum dynamics can be used to enhance desired features in the photoelectron spectra and angular distributions. To this end, we combine Krotov's method for optimal control theory with the time-dependent configuration interaction singles formalism and a splitting approach to calculate photoelectron spectra and angular distributions. The optimization target can account for specific desired properties in the photoelectron angular distribution alone, in the photoelectron spectrum, or in both. We demonstrate the method for hydrogen and then apply it to argon under strong XUV radiation, maximizing the difference of emission into the upper and lower hemispheres, in order to realize directed electron emission in the XUV regime.
Angular Diameter Distances in Clumpy Friedmann Universes
Tomita, K
1998-01-01
Solving null-geodesic equations, behavior of angular diameter distances is studied in inhomogeneous cosmological models, which are given by performing N-body simulations with the CDM spectrum. The distances depend on the separation angle of ray pairs, the mass and the radius of particles cosisting of galaxies and dark matter balls, and cosmological model parameters. The calculated distances are compared with the Dyer- Roeder distance, and after many ray-shooting, the average, dispersion and distribution of the clumpiness parameter are derived.
Degradation nonuniformity in the solar diffuser bidirectional reflectance distribution function.
Sun, Junqiang; Chu, Mike; Wang, Menghua
2016-08-01
The assumption of angular dependence stability of the solar diffuser (SD) throughout degradation is critical to the on-orbit calibration of the reflective solar bands (RSBs) in many satellite sensors. Recent evidence has pointed to the contrary, and in this work, we present a thorough investigative effort into the angular dependence of the SD degradation for the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite and for the twin Moderate-resolution Imaging Spectroradiometer (MODIS) onboard Terra and Aqua spacecrafts. One common key step in the RSB calibration is the use of the SD degradation performance measured by an accompanying solar diffuser stability monitor (SDSM) as a valid substitute for the SD degradation factor in the direction of the RSB view. If SD degradations between these two respective directions do not maintain the same relative relationship over time, then the unmitigated use of the SDSM-measured SD degradation factor in the RSB calibration calculation will generate bias, and consequently, long-term drift in derived science products. We exploit the available history of the on-orbit calibration events to examine the response of the SDSM and the RSB detectors to the incident illumination reflecting off SD versus solar declination angle and show that the angular dependency, particularly at short wavelengths, evolves with respect to time. The generalized and the decisive conclusion is that the bidirectional reflectance distribution function (BRDF) of the SD degrades nonuniformly with respect to both incident and outgoing directions. Thus, the SDSM-based measurements provide SD degradation factors that are biased relative to the RSB view direction with respect to the SD. The analysis also reveals additional interesting phenomena, for example, the sharp behavioral change in the evolving angular dependence observed in Terra MODIS and SNPP VIIRS. For SNPP VIIRS the mitigation for this
Factors influencing perceived angular velocity
Kaiser, Mary K.; Calderone, Jack B.
1991-01-01
Angular velocity perception is examined for rotations both in depth and in the image plane and the influence of several object properties on this motion parameter is explored. Two major object properties are considered, namely, texture density which determines the rate of edge transitions for rotations in depth, i.e., the number of texture elements that pass an object's boundary per unit of time, and object size which determines the tangential linear velocities and 2D image velocities of texture elements for a given angular velocity. Results of experiments show that edge-transition rate biased angular velocity estimates only when edges were highly salient. Element velocities had an impact on perceived angular velocity; this bias was associated with 2D image velocity rather than 3D tangential velocity. Despite these biases judgements were most strongly determined by the true angular velocity. Sensitivity to this higher order motion parameter appeared to be good for rotations both in depth (y-axis) and parallel to the line of sight (z-axis).
A Stern-Gerlach-like approach to electron orbital angular momentum measurement
Harvey, Tyler R
2016-01-01
Many methods now exist to prepare free electrons into orbital angular momentum states, and the predicted applications of these electron states as probes of materials and scattering processes are numerous. The development of electron orbital angular momentum measurement techniques has lagged behind. We show that coupling between electron orbital angular momentum and a spatially varying magnetic field produces an angular momentum-dependent focusing effect. We propose a design for an orbital angular momentum measurement device built on this principle. As the method of measurement is non-interferometric, the device works equally well for mixed, superposed and pure final orbital angular momentum states. The energy and orbital angular momentum distributions of inelastically scattered electrons may be simultaneously measurable with this technique.
On the transformations generated by the electromagnetic spin and orbital angular momentum operators
Fernandez-Corbaton, Ivan; Molina-Terriza, Gabriel
2013-01-01
We present a study of the properties of the transversal "spin angular momentum" and "orbital angular momentum" operators. We show that the "spin angular momentum" operators are generators of spatial translations which depend on helicity and frequency and that the "orbital angular momentum" operators generate transformations which are a sequence of this kind of translations and rotations. We give some examples of the use of these operators in light matter interaction problems. Their relationship with the helicity operator allows to involve the electromagnetic duality symmetry in the analysis. We also find that simultaneous eigenstates of the three "spin" operators and parity define a kind of standing modes which have been recently singled out for the interaction of light with chiral molecules. With respect to the relationship between "spin angular momentum", polarization, and total angular momentum, we show that, except for the case of a single plane wave, the total angular momentum of a beam is decoupled from...
International Nuclear Information System (INIS)
It is well known that, for any monochromatic field, the spatial extent of the focus has a lower bound dependent on the field's directional spread. The influences that the orbital angular momentum and, for vector fields, the (spin or intrinsic) angular momentum due to polarization have on this lower bound are studied here for fields not constrained by the paraxial approximation
Menard, Dan
2013-01-01
Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. This book is written in an easytoread style, with a strong emphasis on realworld, practical examples. Stepbystep explanations are provided for performing important tasks.This book is for web developers familiar with JavascriptIt doesn't cover the history of AngularJS, and it's not a pitch to convince you that AngularJS is the best framework on the entire web. It's a guide to help you learn everything you need to know about AngularJS in as few pa
Non-Colinearity of Angular Velocity and Angular Momentum
Burr, A. F.
1974-01-01
Discusses the principles, construction, and operation of an apparatus which serves to demonstrate the non-colinearity of the angular velocity and momentum vectors as well as the inertial tensors. Applications of the apparatus to teaching of advanced undergraduate mechanics courses are recommended. (CC)
Quantum theory of angular momentum
International Nuclear Information System (INIS)
This monograph pertains to the angular momentum coupling and recoupling coefficients and their relation to generalized hypergeometric functions; their q-generalization; their polynomial zeros; their relation to orthogonal polynomials; and their numerical computation. The book builds on standard textbook material on Angular Momentum Theory and leads the reader to the recent developments in the selected topics. Fortran programs for the computation of the 3-j, 6-j and 9-j coefficients are included for use by atomic, molecular and nuclear physicists/chemists. (orig.)
Gillette, Brandon; Hamilton, Cheri
2011-01-01
When viewing objects of different colors, you might notice that some appear brighter than others. This is because light is reflected differently from various surfaces, depending on their physical properties. The word "albedo" is used to describe how reflective a surface is. The Earth-atmosphere has a combined albedo of about 30%, a number that is…
REVIEW ARTICLE: Angular selective window coatings: theory and experiments
Mbise, G. W.; LeBellac, D.; Niklasson, G. A.; Granqvist, C. G.
1997-08-01
This review is devoted to the angular selectivity that can be obtained in thin films prepared under conditions such that they contain inclined absorbing regions of sizes much smaller than the wavelength of visible light. The films are of considerable interest as window coatings for energy-conscious architecture and, potentially, in the automotive sector. The theoretical basis for modelling the optical properties is presented, comprising rigorous bounds on the dielectric function, effective medium theories pertinent to different microgeometries and equations for treating the optics of anisotropic thin films. Experimental data are reported for films made by oblique-angle evaporation of Cr and for reactive and non-reactive oblique-angle sputtering of Cr, Al, Ti and W. The highest angular selectivity was obtained with evaporated Cr, whereas the highest luminous transmittance, combined with some angular selectivity, was found with reactively sputtered Al. Films made from Ti showed angular selectivity mainly in the infrared, whereas films made from W could display angular selective electrochromism. Samples of several types were subjected to elaborate theoretical analysis using effective-medium theories and it was seen that theory and experiment could be reconciled using plausible parameters to specify the microstructures of the films. Thus it appears that the angular, spectral and polarization dependences of obliquely deposited films can be understood, at least approximately, in terms of conceptually simple theoretical models.
Bouchard, Frédéric; De Leon, Israel; Schulz, Sebastian A.; Upham, Jeremy; Karimi, Ebrahim; Boyd, Robert W.
2014-01-01
Orbital angular momentum associated with the helical phase-front of optical beams provides an unbounded \\qo{space} for both classical and quantum communications. Among the different approaches to generate and manipulate orbital angular momentum states of light, coupling between spin and orbital angular momentum allows a faster manipulation of orbital angular momentum states because it depends on manipulating the polarisation state of light, which is simpler and generally faster than manipulat...
Turbodrill rod angular velocity indicator
Energy Technology Data Exchange (ETDEWEB)
Rogachev, O.K.; Belozerova, L.P.; Konenkov, A.K.
1984-01-01
This paper outlines shortcomings of existing types of telemetry systems which resulted in production of the IChT-1 unit. Unit is intended for control of angular velocity of serially produced turbodrill rods, during drilling of wells up to 5000 m deep, and bottomhole temperatures to 100C. The paper provides a detailed description and diagrams for installing this unit.
Inverse cascades of angular momentum
International Nuclear Information System (INIS)
Most theoretical and computational studies of turbulence in Navier-Stokes fluids and/or guiding-centre plasmas have been carried out in the presence of spatially periodic boundary conditions. In view of the frequently reproduced result that two-dimensional and/or MHD decaying turbulence leads to structures comparable in length scae to a box dimension, it is natural to ask if periodic boundary conditions are an adequate representation of any physical situation. Here, we study, computationally, the decay of two-dimensional turbulence in a Navier-Stokes fluid or guiding-centre plasma in the presence of circular no-slip rigid walls. The method is wholly spectral, and relies on a Galerkin approximation by a set of functions that obey two boundary conditions at the wall radius (analogues of the Chandrasekhar-Reid functions). It is possible to explore Reynolds numbers up to the order of 1250, based on an RMS velocity and a box radius. It is found that decaying turbulence is altered significantly by the no-slip boundaries. First, strong boundary layers serve as sources of vorticity and enstrophy and enhance the early-time energy decay rate, for a given Reynolds number, well above the periodic boundary condition values. More importantly, angular momentum turns out to be an even more slowly decaying ideal invariant than energy, and to a considerable extent governs the dynamics of the decay. Angular momentum must be taken into account, for example, in order to achieve quantitative agreement with the prediction of maximum entropy, or 'most probable', states. These are predictions of conditions that are established after several eddy turnover times but before the energy has decayed away. Angular momentum will cascade to lower azimuthal mode numbers, even if absent there initially, and the angular momentum modal spectrum is eventually dominated by the lowest mode available. When no initial angular momentum is present, no behaviour that suggests the likelihood of inverse cascades
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav
2014-01-01
Roč. 90, č. 5 (2014), "052007-1"-"052007-26". ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : scattering flavor * ATLAS * time dependence * CERN LHC Coll Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014
Czech Academy of Sciences Publication Activity Database
Aad, G.; Abajyan, T.; Abbott, B.; Böhm, Jan; Chudoba, Jiří; Gallus, Petr; Gunther, Jaroslav; Jakoubek, Tomáš; Juránek, Vojtěch; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Marčišovský, Michal; Mikeštíková, Marcela; Myška, Miroslav; Němeček, Stanislav; Růžička, Pavel; Schovancová, Jaroslava; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Tic, Tomáš; Valenta, J.; Vrba, Václav; Zeman, Martin
2012-01-01
Roč. 2012, č. 12 (2012), s. 1-18. ISSN 1029-8479 R&D Projects: GA MŠk LA08032 Institutional support: RVO:68378271 Keywords : scattering * J/psi(3100) * ATLAS * time dependence * B/s0 * lifetime * amplitude analysis * transversity * experimental results * CERN LHC Coll Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders
Plate tectonics conserves angular momentum
Directory of Open Access Journals (Sweden)
C. Bowin
2009-03-01
Full Text Available A new combined understanding of plate tectonics, Earth internal structure, and the role of impulse in deformation of the Earth's crust is presented. Plate accelerations and decelerations have been revealed by iterative filtering of the quaternion history for the Euler poles that define absolute plate motion history for the past 68 million years, and provide an unprecedented precision for plate angular rotation variations with time at 2-million year intervals. Stage poles represent the angular rotation of a plate's motion between adjacent Euler poles, and from which the maximum velocity vector for a plate can be determined. The consistent maximum velocity variations, in turn, yield consistent estimates of plate accelerations and decelerations. The fact that the Pacific plate was shown to accelerate and decelerate, implied that conservation of plate tectonic angular momentum must be globally conserved, and that is confirmed by the results shown here (total angular momentum ~1.4 E+27 kgm^{2}s^{−1}. Accordingly, if a plate decelerates, other plates must increase their angular momentums to compensate. In addition, the azimuth of the maximum velocity vectors yields clues as to why the "bend" in the Emperor-Hawaiian seamount trend occurred near 46 Myr. This report summarizes processing results for 12 of the 14 major tectonic plates of the Earth (except for the Juan de Fuca and Philippine plates. Plate accelerations support the contention that plate tectonics is a product of torques that most likely are sustained by the sinking of positive density anomalies due to phase changes in subducted gabbroic lithosphere at depth in the upper lower mantle (above 1200 km depth. The tectonic plates are pulled along by the sinking of these positive mass anomalies, rather than moving at near constant velocity on the crests of convection cells driven by rising heat. These results imply that spreading centers are primarily passive reactive
Orbital angular momentum in phase space
Rigas, I.; Sanchez-Soto, L. L.; Klimov, A. B.; Rehacek, J.; Hradil, Z.
2010-01-01
A comprehensive theory of the Weyl-Wigner formalism for the canonical pair angle-angular momentum is presented. Special attention is paid to the problems linked to rotational periodicity and angular-momentum discreteness.
AngularJS test-driven development
Chaplin, Tim
2015-01-01
This book is for developers who want to learn about AngularJS development by applying testing techniques. You are assumed to have a basic knowledge and understanding of HTML, JavaScript, and AngularJS.
Phonons with orbital angular momentum
Energy Technology Data Exchange (ETDEWEB)
Ayub, M. K. [Theoretical Plasma Physics Division, PINSTECH, P. O. Nilore, Islamabad (Pakistan); National Centre for Physics, Shahdra Valley Road, Quaid-i-Azam University Campus, Islamabad 44000 (Pakistan); Ali, S. [National Centre for Physics, Shahdra Valley Road, Quaid-i-Azam University Campus, Islamabad 44000 (Pakistan); Mendonca, J. T. [IPFN, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal)
2011-10-15
Ion accoustic waves or phonon modes are studied with orbital angular momentum (OAM) in an unmagnetized collissionless uniform plasma, whose constituents are the Boltzmann electrons and inertial ions. For this purpose, we have employed the fluid equations to obtain a paraxial equation in terms of ion density perturbations and discussed its Gaussian beam and Laguerre-Gauss (LG) beam solutions. Furthermore, an approximate solution for the electrostatic potential problem is presented, allowing to express the components of the electric field in terms of LG potential perturbations. The energy flux due to phonons is also calculated and the corresponding OAM is derived. Numerically, it is shown that the parameters such as azimuthal angle, radial and angular mode numbers, and beam waist, strongly modify the profiles of the phonon LG potential. The present results should be helpful in understanding the phonon mode excitations produced by Brillouin backscattering of laser beams in a uniform plasma.
Phonons with orbital angular momentum
International Nuclear Information System (INIS)
Ion accoustic waves or phonon modes are studied with orbital angular momentum (OAM) in an unmagnetized collissionless uniform plasma, whose constituents are the Boltzmann electrons and inertial ions. For this purpose, we have employed the fluid equations to obtain a paraxial equation in terms of ion density perturbations and discussed its Gaussian beam and Laguerre-Gauss (LG) beam solutions. Furthermore, an approximate solution for the electrostatic potential problem is presented, allowing to express the components of the electric field in terms of LG potential perturbations. The energy flux due to phonons is also calculated and the corresponding OAM is derived. Numerically, it is shown that the parameters such as azimuthal angle, radial and angular mode numbers, and beam waist, strongly modify the profiles of the phonon LG potential. The present results should be helpful in understanding the phonon mode excitations produced by Brillouin backscattering of laser beams in a uniform plasma.
Angular momentum in QGP holography
Directory of Open Access Journals (Sweden)
Brett McInnes
2014-10-01
Full Text Available The quark chemical potential is one of the fundamental parameters describing the quark–gluon plasma produced by sufficiently energetic heavy-ion collisions. It is not large at the extremely high temperatures probed by the LHC, but it plays a key role in discussions of the beam energy scan programmes at the RHIC and other facilities. On the other hand, collisions at such energies typically (that is, in peripheral collisions give rise to very high values of the angular momentum density. Here we explain that holographic estimates of the quark chemical potential of a rotating sample of plasma can be very considerably improved by taking the angular momentum into account.
Angular distribution of coherent bremsstrahlung
International Nuclear Information System (INIS)
The angular distribution of the linearly polarised photon beam produced by coherent bremsstrahlung from an aligned diamond radiator has been measured at the MAMI A2 tagged photon facility. The measurements were made with a prototype position sensitive photon detector which utilises the pair production process and a double sided silicon strip detector. This polarised photon beam is used for nuclear and hadronic experiments and in their analysis the polarisation is obtained from a calculation, which matches the experimental intensity spectrum. As the polarisation is related to the photon beam angular distribution, the present measurements can be used to test this calculation. The overall agreement is found to be good although there are some regions where significant discrepancies exist.
The integration of angular velocity
Boyle, Michael
2016-01-01
A common problem in physics and engineering is determination of the orientation of an object given its angular velocity. When the direction of the angular velocity changes in time, this is a nontrivial problem involving coupled differential equations. Several possible approaches are examined, along with various improvements over previous efforts. These are then evaluated numerically by comparison to a complicated but analytically known rotation that is motivated by the important astrophysical problem of precessing black-hole binaries. It is shown that a straightforward solution directly using quaternions is most efficient and accurate, and that the norm of the quaternion is irrelevant. Integration of the generator of the rotation can also be made roughly as efficient as integration of the rotation. Both methods will typically be twice as efficient naive vector- or matrix-based methods. Implementation by means of standard general-purpose numerical integrators is stable and efficient, so that such problems can ...
Orbital angular momentum of general astigmatic modes
International Nuclear Information System (INIS)
We present an operator method to obtain complete sets of astigmatic Gaussian solutions of the paraxial wave equation. In case of general astigmatism, the astigmatic intensity and phase distribution of the fundamental mode differ in orientation. As a consequence, the fundamental mode has a nonzero orbital angular momentum, which is not due to phase singularities. Analogous to the operator method for the quantum harmonic oscillator, the corresponding astigmatic higher-order modes are obtained by repeated application of raising operators on the fundamental mode. The nature of the higher-order modes is characterized by a point on a sphere, in analogy with the representation of polarization on the Poincare sphere. The north and south poles represent astigmatic Laguerre-Gaussian modes, similar to circular polarization on the Poincare sphere, while astigmatic Hermite-Gaussian modes are associated with points on the equator, analogous to linear polarization. We discuss the propagation properties of the modes and their orbital angular momentum, which depends on the degree of astigmatism and on the location of the point on the sphere
Understanding GRETINA using angular correlation method
Austin, Madeline
2015-10-01
The ability to trace the path of gamma rays through germanium is not only necessary for taking full advantage of GRETINA but also a promising possibility for homeland security defense against nuclear threats. This research tested the current tracking algorithm using the angular correlation method by comparing results from raw and tracked data to the theoretical model for Co-60. It was found that the current tracking method is unsuccessful in reproducing angular correlation. Variations to the tracking algorithm were made in the FM value, tracking angle, number of angles of separation observed, and window of coincidence in attempt to improve correlation results. From these variations it was observed that having a larger FM improved results, reducing the number of observational angles worsened correlation, and that overall larger tracking angles improved with larger windows of coincidence and vice-verse. Future research would be to refine the angle of measurement for raw data and to explore the possibility of an energy dependence by testing other elements. This work is supported by the United States Department of Energy, Office of Science, under Contract Number DE-AC02-06CH11357
Integrating rotation from angular velocity
Zupan, Eva; Saje, Miran
2011-01-01
Abstract The integration of the rotation from a given angular velocity is often required in practice. The present paper explores how the choice of the parametrization of rotation, when employed in conjuction with different numerical time-integration schemes, effects the accuracy and the computational efficiency. Three rotation parametrizations – the rotational vector, the Argyris tangential vector and the rotational quaternion – are combined with three different numerical time-integration ...
Spin Angular Momentum Imparted by Gravitational Waves
Sharif, M.
2007-01-01
Following the demonstration that gravitational waves impart linear momentum, it is argued that if they are polarized they should impart angular momentum to appropriately placed 'test rods' in their path. A general formula for this angular momentum is obtained and used to provide expressions for the angular momentum imparted by plane and cylindrical gravitational waves.
Angular Momentum Decomposition for an Electron
Burkardt, Matthias; BC, Hikmat
2008-01-01
We calculate the orbital angular momentum of the `quark' in the scalar diquark model as well as that of the electron in QED (to order $\\alpha$). We compare the orbital angular momentum obtained from the Jaffe-Manohar decomposition to that obtained from the Ji relation and estimate the importance of the vector potential in the definition of orbital angular momentum.
AngularJS web application development
Darwin, Peter Bacon
2013-01-01
The book will be a step-by-step guide showing the readers how to build a complete web app with AngularJSJavaScript developers who want to learn AngularJS for developing web apps. Knowledge of JavaScript and HTML is expected. No knowledge of AngularJS is required.
Angular Spacing Control for Segmented Data Pages in Angle-Multiplexed Holographic Memory
Kinoshita, Nobuhiro; Muroi, Tetsuhiko; Ishii, Norihiko; Kamijo, Koji; Kikuchi, Hiroshi; Shimidzu, Naoki; Ando, Toshio; Masaki, Kazuyoshi; Shimizu, Takehiro
2011-09-01
To improve the recording density of angle-multiplexed holographic memory, it is effective to increase the numerical aperture of the lens and to shorten the wavelength of the laser source as well as to increase the multiplexing number. The angular selectivity of a hologram, which determines the multiplexing number, is dependent on the incident angle of not only the reference beam but also the signal beam to the holographic recording medium. The actual signal beam, which is a convergent or divergent beam, is regarded as the sum of plane waves that have different propagation directions, angular selectivities, and optimal angular spacings. In this paper, focusing on the differences in the optimal angular spacing, we proposed a method to control the angular spacing for each segmented data page. We investigated the angular selectivity of a hologram and crosstalk for segmented data pages using numerical simulation. The experimental results showed a practical bit-error rate on the order of 10-3.
Templates for the Sunyaev-Zel'dovich Angular Power Spectrum
Trac, Hy; Ostriker, Jeremiah P
2010-01-01
We present templates for the Sunyaev-Zel'dovich (SZ) angular power spectrum based on four models for the nonlinear gas distribution. The frequency-dependent SZ temperature fluctuations, with thermal (TSZ) and kinetic (KSZ) contributions, are calculated by tracing through a dark matter simulation, processed to include gas in dark matter halos and in the filamentary intergalactic medium. Different halo gas models are compared to study how star formation, energetic feedback, and nonthermal pressure support influence the angular power spectrum. The standard model has been calibrated to reproduce the stellar and gas fractions and X-ray scaling relations measured from low redshift clusters and groups. The other models illustrate the current theoretical and empirical uncertainties relating to properties of the intracluster medium. Relative to the standard model, their angular power spectra differ by approximately 50% (TSZ), 20% (KSZ), and 40% (SZ at 148 GHz) for l=3000, sigma_8=0.8, and homogeneous reionization at z...
Valley-contrasting orbital angular momentum in photonic valley crystals
Chen, Xiaodong; Dong, Jianwen
2016-01-01
Valley, as a degree of freedom, has been exploited to realize valley-selective Hall transport and circular dichroism in two-dimensional layered materials. On the other hand, orbital angular momentum of light with helical phase distribution has attracted great attention for its unprecedented opportunity to optical communicagtions, atom trapping, and even nontrivial topology engineering. Here, we reveal valley-contrasting orbital angular momentum in all-dielectric photonic valley crystals. Selective excitation of valley chiral bulk states is realized by sources carrying orbital angular momentum with proper chirality. Valley dependent edge states, predictable by nonzero valley Chern number, enable to suppress the inter-valley scattering along zigzag boundary, leading to broadband robust transmission in Z-shape bend without corner morphological optimization. Our work may open up a new door towards the discovery of novel quantum states and the manipulation of spin-orbit interaction of light in nanophotonics.
International Nuclear Information System (INIS)
In 2005, PISA organised proactive meetings of reflection groups on involvement in decision making, expert culture and ethical aspects of radiation protection.All reflection group meetings address particular targeted audiences while the output publication in book form is put forward
Fang, Liang; Wang, Jian
2015-09-01
By exploiting helical gratings (HGs), we propose and simulate flexible generation, conversion, and exchange of fiber-guided orbital angular momentum (OAM) modes. HGs can enable the generation of OAM modes, and the OAM conversion between two arbitrary modes guided in fibers. A specific HG can exchange the OAM states of a couple of OAM modes, i.e., OAM exchange. In addition, a Fabry-Perot (F-P) cavity cascaded with two identical reflective HGs can reflect converted OAM modes with a comb spectrum. The HG-based generation/conversion/exchange of OAM modes are dependent on helix period, orientation, and the fold number of helical fringes. The proposed method of generation, conversion, and exchange of fiber-guided OAM modes using HGs is flexible and well compatible with OAM fibers, featuring a high conversion efficiency close to 100% and a conversion bandwidth about 10 nm in transmission spectra, while less than 1 nm in reflection spectra. PMID:26368699
Angular reduction in multiparticle matrix elements
International Nuclear Information System (INIS)
A general method for reduction of coupled spherical harmonic products is presented. When the total angular coupling is zero, the reduction leads to an explicitly real expression in the scalar products of the unit vector arguments of the spherical harmonics. For nonscalar couplings, the reduction gives Cartesian tensor forms for the spherical harmonic products; tensors built from the physical vectors in the original expression. The reduction for arbitrary couplings is given in closed form, making it amenable to symbolic manipulation on a computer. The final expressions do not depend on a special choice of coordinate axes, nor do they contain azimuthal quantum number summations, or do they have complex tensor terms for couplings to a scalar; consequently, they are easily interpretable from the properties of the physical vectors they contain
Angular energy response of personnel thermoluminescent dosimeters
International Nuclear Information System (INIS)
The angular energy dependence of the response of two commercial thermoluminescent dosimeter systems was investigated. The first personnel dosimeter investigated was the Radi-Guard which is a multi-area LiF (TLD-700) locked in Teflon matrix and incorporated with a PB-2 holder developed by Teledyne Isotopes. The second one was the BG-7 which is comprised of two LiF (TLD-700) chips developed by Harshaw, but the TH-2 holder was fabricated at National Tsing Hua University. The angle of incidence was varied from perpendicular to parallel for 90Sr-90Y β radiation, 241Am and 60Co γ radiation. Experimental results are presented and discussed
Malik, Mehul; Leach, Jonathan; Boyd, Robert W
2012-01-01
We implement an interferometric method using two angular slits to measure the orbital angular momentum (OAM) mode spectrum of a partially coherent field. As the angular separation of the slits changes, an interference pattern for a particular OAM mode is obtained. The visibility of this interference pattern as a function of angular separation is equivalent to the angular correlation function of the field. By Fourier transforming the angular correlation function obtained from the double angular slit interference, we are able to calculate the OAM spectrum of the partially coherent field. This method has potential application for characterizing the OAM spectrum in high-dimensional quantum information protocols.
Ultrashort Laguerre-Gaussian pulses with angular and group velocity dispersion compensation.
Zeylikovich, I; Sztul, H I; Kartazaev, V; Le, T; Alfano, R R
2007-07-15
Coherent optical vortices are generated from ultrashort 6.4 fs pulses. Our results demonstrate angular dispersion compensation of ultrashort 6.4 fs Laguerre-Gaussian (LG) pulses as well as what is believed to be the first direct autocorrelation measurement of 80 fs LG amplified pulses. A reflective-mirror-based 4f-compressor is proposed to compensate the angular and group velocity dispersion of the ultrashort LG pulses. PMID:17632631
An optical filter with angular selectivity of the light transmission
Zakirullin, Rustam S.
2015-09-01
Features of the application of a novel optical filter with angular selectivity of the light transmission to architectural glazing are considered. The filter consists of a sheet transparent substrate with thin-film grating layers on both surfaces. The gratings formed by directionally transmissive strips, alternating with absorptive, reflective, or scattering strips. Their relative position on the input and output surfaces provides angular selectivity of the directional light transmission - as the incidence angle changes, the proportion of radiation that passes through both gratings of the filter also changes. Chromogenic materials currently used in the laminated smart windows, providing control over the intensity and spectrum of the transmitted solar radiation, cannot achieve the selective regulation on the ranges of incidence angles. Such a regulation requires the use of additional daylight-redirecting devices, especially blinds, to dynamically adapt to the position of the sun. The grating optical filter provides angular selectivity of the light transmission of a window without such devices. The features of using this filter in the single and double glazed windows are described. A graphic analytical calculation method is proposed for estimating the effect of geometrical and optical parameters of the filter on the angular characteristics of the light transmission. An algorithm to optimize filtering solar radiation taking into account the geographical coordinates of terrain, time of day and year and the orientation of the window to the cardinal is set. An algorithm to calculating geometrical parameters of the filter with pre-specified characteristics of the light transmission is obtained.
DEFF Research Database (Denmark)
Alcock, Gordon Lindsay
2013-01-01
This paper documents 1st semester student reflections on “learning to learn” in a team-based PBL environment with quantitative and qualitative student reflective feedback on the learning gains of 60 Architectural Technology and Construction Management students at VIA University College, Denmark. It...... contrasts the students’ self-assessment in a range of ‘product’ skills such as Revit, Structural Design, Mathematics of construction, Technical Installations; as well as ‘process’ competencies such as ‘Working in a team’, Sharing knowledge, Maintaining a portfolio and Reflecting ON learning and FOR learning...
Matter waves with angular momentum
Bracher, C; Kleber, M; Bracher, Christian; Kramer, Tobias; Kleber, Manfred
2003-01-01
An alternative description of quantum scattering processes rests on inhomogeneous terms amended to the Schr\\"odinger equation. We detail the structure of sources that give rise to multipole scattering waves of definite angular momentum, and introduce pointlike multipole sources as their limiting case. Partial wave theory is recovered for freely propagating particles. We obtain novel results for ballistic scattering in an external uniform force field, where we provide analytical solutions for both the scattering waves and the integrated particle flux. As an illustration of the theory, we predict some properties of vortex-bearing atom laser beams outcoupled from a rotating Bose--Einstein condensate under the influence of gravity.
International Nuclear Information System (INIS)
A new class of coplanar two-axis angular effectors is described. These effectors combine a two-axis rotational joint analogous to a Cardan joint with linear actuators in a manner to produce a wider range of rotational motion about both axes defined by the joint. This new class of effectors also allows design of robotic manipulators having very high strength and efficiency. These effectors are particularly suited for remote operation in unknown surroundings, because of their extraordinary versatility. An immediate application is to the problems which arise in nuclear waste remediation. 11 figs
Directory of Open Access Journals (Sweden)
P. A. González Crespo
2013-01-01
Full Text Available Six specimens of an aluminum alloy (AA-5083 extruded by Equal Channel Angular Pressing following two different routes plus a blank sample were examined with a neutron radiation of 1.5448 Å. Macrostrain maps from the (311 reflection were obtained. A clear difference about accumulated macrostrain with the extrusion cycles between the two routes is shown. The diffraction data of annealed specimens did permit to estimate crystallite sizes that range between 89 nm and 115 nm depending on the routes.
González Crespo, P. A.; C. Luis Pérez; Hughes, Darren J.; Turrillas, X.
2013-01-01
Six specimens of an aluminum alloy (AA-5083) extruded by Equal Channel Angular Pressing following two different routes plus a blank sample were examined with a neutron radiation of 1.5448 Å. Macrostrain maps from the (311) reflection were obtained. A clear difference about accumulated macrostrain with the extrusion cycles between the two routes is shown. The diffraction data of annealed specimens did permit to estimate crystallite sizes that range between 89 nm and 115 nm depending on the rou...
Evers, N.M.; Klundert, van de T.M.C.; Aesch, van Y.M.; Wang, S.; Roos, de W.K.; Romano, A.; Haan, de L.H.J.; Murk, A.J.; Ederveen, A.G.H.; Rietjens, I.M.C.M.; Groten, J.P.
2013-01-01
T47D-ER beta breast cancer cells with tetracycline-dependent ER beta expression and constant ER alpha expression can be used to investigate effects of varying ER alpha/ER beta ratios on estrogen-induced cellular responses. This study defines conditions at which ER alpha/ER beta ratios in T47D-ER bet
Fernando, J; Pilorget, C; Pinet, P; Ceamanos, X; Douté, S; Daydou, Y; Costard, F
2014-01-01
The analysis of the surface texture from the particle (grain size, shape and internal structure) to its organization (surface roughness) provides information on the geological processes. CRISM multi-angular observations (varied emission angles) allow to characterize the surface scattering behavior which depends on the composition but also the material physical properties (e.g., grain size, shape, internal structure, the surface roughness). After an atmospheric correction by the Multi-angle Approach for Retrieval of the Surface Reflectance from CRISM Observations, the surface reflectances at different geometries are analyzed by inverting the Hapke photometric model depending on the single scattering albedo, the 2-term phase function, the macroscopic roughness and the 2-term opposition effects. Surface photometric maps are created to observe the spatial variations of surface scattering properties as a function of geological units at the CRISM spatial resolution (200m/pixel). An application at the Mars Explorati...
Role of electron-molecule angular scattering in shaping the electron-velocity distribution
Energy Technology Data Exchange (ETDEWEB)
Kunhardt, E.E.; Tzeng, Y.
1986-09-01
Five models has been studied to elucidate the role of electron-molecule angular scattering in shaping the velocity distribution for electrons in nitrogen at E/N values of 300 and 1500 Td. The angular dependence of the differential scattering cross sections for elastic and inelastic collisions has been observed to have significant effects on the shape of the velocity distribution, the rate coefficients, and the transport parameters. The velocity distribution is most sensitive to the angular dependence of elastic scattering. Moreover, for a given elastic differential scattering cross section, variations in the angular dependence of inelastic scattering cause significant changes in the distribution. The magnitude of these changes depends on the relative action of the inelastic collisions with respect to the elastic collisions for a given energy interval, i.e., whether the scattering by the inelastic collisions is isotropic, forward, or backward in a given energy interval.
Reflective self-awareness and conscious states
DEFF Research Database (Denmark)
Kjaer, Troels W; Nowak, Markus; Lou, Hans C
2002-01-01
A recent meta-analysis has shown precuneus, angular gyri, anterior cingulate gyri, and adjacent structures to be highly metabolically active in support of resting consciousness. We hypothesize that these regions constitute a functional network of reflective self-awareness thought to be a core...... during reflective self-awareness. The commonality between the neural networks of the resting conscious state and self-awareness reflects the phenomenological concept of a fundamental contribution of reflective self-awareness to the contents and coherence of the conscious state....
Controlling neutron orbital angular momentum.
Clark, Charles W; Barankov, Roman; Huber, Michael G; Arif, Muhammad; Cory, David G; Pushin, Dmitry A
2015-09-24
The quantized orbital angular momentum (OAM) of photons offers an additional degree of freedom and topological protection from noise. Photonic OAM states have therefore been exploited in various applications ranging from studies of quantum entanglement and quantum information science to imaging. The OAM states of electron beams have been shown to be similarly useful, for example in rotating nanoparticles and determining the chirality of crystals. However, although neutrons--as massive, penetrating and neutral particles--are important in materials characterization, quantum information and studies of the foundations of quantum mechanics, OAM control of neutrons has yet to be achieved. Here, we demonstrate OAM control of neutrons using macroscopic spiral phase plates that apply a 'twist' to an input neutron beam. The twisted neutron beams are analysed with neutron interferometry. Our techniques, applied to spatially incoherent beams, demonstrate both the addition of quantum angular momenta along the direction of propagation, effected by multiple spiral phase plates, and the conservation of topological charge with respect to uniform phase fluctuations. Neutron-based studies of quantum information science, the foundations of quantum mechanics, and scattering and imaging of magnetic, superconducting and chiral materials have until now been limited to three degrees of freedom: spin, path and energy. The optimization of OAM control, leading to well defined values of OAM, would provide an additional quantized degree of freedom for such studies. PMID:26399831
Dijet angular distributions in direct and resolved photoproduction at HERA
International Nuclear Information System (INIS)
Jet photoproduction, where the two highest transverse energy (ETjet) jets have ETjet above 6 GeV and a jet-jet invariant mass above 23 GeV, has been studied with the ZEUS detector at the HERA ep collider. Resolved and direct photoproduction samples have been separated. The cross section as a function of the angle between the jet-jet axis and the beam direction in the dijet rest frame has been measured for the two samples. The measured angular distributions differ markedly from each other. They agree with the predictions of QCD calculations, where the different angular distributions reflect the different spins of the quark and gluon exchanged in the hard subprocess. (orig.)
High angular sensitivity thin film tin oxide sensor
Kaur, Davinder; Madaan, Divya; Sharma, V. K.; Kapoor, A.
2016-05-01
We present theoretical anlaysis of a thin film SnO2 (Tin Oxide) sensor for the measurement of variation in the refractive index of the bulk media. It is based on lossy mode resonance between the absorbing thin film lossy modes and the evanescent wave. Also the addition of low index dielectric matching layer between the prism and the lossy waveguiding layer future increase the angular sensitivity and produce an efficient refractive index sensor. The angular interrogation is done and obtained sensitivity is 110 degree/RIU. Theoretical analysis of the proposed sensor based on Fresnel reflection coefficients is presented. This enhanced sensitivity will further improve the monitoring of biomolecular interactions and the higher sensitivity of the proposed configurations makes it to be a much better option to be employed for biosensing applications.
Helicon modes in uniform plasmas. III. Angular momentum
International Nuclear Information System (INIS)
Helicons are electromagnetic waves with helical phase fronts propagating in the whistler mode in magnetized plasmas and solids. They have similar properties to electromagnetic waves with angular momentum in free space. Helicons are circularly polarized waves carrying spin angular momentum and orbital angular momentum due to their propagation around the ambient magnetic field B0. These properties have not been considered in the community of researchers working on helicon plasma sources, but are the topic of the present work. The present work focuses on the field topology of helicons in unbounded plasmas, not on helicon source physics. Helicons are excited in a large uniform laboratory plasma with a magnetic loop antenna whose dipole axis is aligned along or across B0. The wave fields are measured in orthogonal planes and extended to three dimensions (3D) by interpolation. Since density and B0 are uniform, small amplitude waves from loops at different locations can be superimposed to generate complex antenna patterns. With a circular array of phase shifted loops, whistler modes with angular and axial wave propagation, i.e., helicons, are generated. Without boundaries radial propagation also arises. The azimuthal mode number m can be positive or negative while the field polarization remains right-hand circular. The conservation of energy and momentum implies that these field quantities are transferred to matter which causes damping or reflection. Wave-particle interactions with fast electrons are possible by Doppler shifted resonances. The transverse Doppler shift is demonstrated. Wave-wave interactions are also shown by showing collisions between different helicons. Whistler turbulence does not always have to be created by nonlinear wave-interactions but can also be a linear superposition of waves from random sources. In helicon collisions, the linear and/or orbital angular momenta can be canceled, which results in a great variety of field topologies. The work will
Helicon modes in uniform plasmas. III. Angular momentum
Energy Technology Data Exchange (ETDEWEB)
Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)
2015-09-15
Helicons are electromagnetic waves with helical phase fronts propagating in the whistler mode in magnetized plasmas and solids. They have similar properties to electromagnetic waves with angular momentum in free space. Helicons are circularly polarized waves carrying spin angular momentum and orbital angular momentum due to their propagation around the ambient magnetic field B{sub 0}. These properties have not been considered in the community of researchers working on helicon plasma sources, but are the topic of the present work. The present work focuses on the field topology of helicons in unbounded plasmas, not on helicon source physics. Helicons are excited in a large uniform laboratory plasma with a magnetic loop antenna whose dipole axis is aligned along or across B{sub 0}. The wave fields are measured in orthogonal planes and extended to three dimensions (3D) by interpolation. Since density and B{sub 0} are uniform, small amplitude waves from loops at different locations can be superimposed to generate complex antenna patterns. With a circular array of phase shifted loops, whistler modes with angular and axial wave propagation, i.e., helicons, are generated. Without boundaries radial propagation also arises. The azimuthal mode number m can be positive or negative while the field polarization remains right-hand circular. The conservation of energy and momentum implies that these field quantities are transferred to matter which causes damping or reflection. Wave-particle interactions with fast electrons are possible by Doppler shifted resonances. The transverse Doppler shift is demonstrated. Wave-wave interactions are also shown by showing collisions between different helicons. Whistler turbulence does not always have to be created by nonlinear wave-interactions but can also be a linear superposition of waves from random sources. In helicon collisions, the linear and/or orbital angular momenta can be canceled, which results in a great variety of field
Helicon modes in uniform plasmas. III. Angular momentum
Stenzel, R. L.; Urrutia, J. M.
2015-09-01
Helicons are electromagnetic waves with helical phase fronts propagating in the whistler mode in magnetized plasmas and solids. They have similar properties to electromagnetic waves with angular momentum in free space. Helicons are circularly polarized waves carrying spin angular momentum and orbital angular momentum due to their propagation around the ambient magnetic field B0. These properties have not been considered in the community of researchers working on helicon plasma sources, but are the topic of the present work. The present work focuses on the field topology of helicons in unbounded plasmas, not on helicon source physics. Helicons are excited in a large uniform laboratory plasma with a magnetic loop antenna whose dipole axis is aligned along or across B0. The wave fields are measured in orthogonal planes and extended to three dimensions (3D) by interpolation. Since density and B0 are uniform, small amplitude waves from loops at different locations can be superimposed to generate complex antenna patterns. With a circular array of phase shifted loops, whistler modes with angular and axial wave propagation, i.e., helicons, are generated. Without boundaries radial propagation also arises. The azimuthal mode number m can be positive or negative while the field polarization remains right-hand circular. The conservation of energy and momentum implies that these field quantities are transferred to matter which causes damping or reflection. Wave-particle interactions with fast electrons are possible by Doppler shifted resonances. The transverse Doppler shift is demonstrated. Wave-wave interactions are also shown by showing collisions between different helicons. Whistler turbulence does not always have to be created by nonlinear wave-interactions but can also be a linear superposition of waves from random sources. In helicon collisions, the linear and/or orbital angular momenta can be canceled, which results in a great variety of field topologies. The work will
Angular velocity and centripetal acceleration relationship
Monteiro, Martín; Cabeza, Cecilia; Marti, Arturo C.; Vogt, Patrik; Kuhn, Jochen
2014-05-01
During the last few years, the growing boom of smartphones has given rise to a considerable number of applications exploiting the functionality of the sensors incorporated in these devices. A sector that has unexpectedly taken advantage of the power of these tools is physics teaching, as reflected in several recent papers. In effect, the use of smartphones has been proposed in several physics experiments spanning mechanics, electromagnetism, optics, oscillations, and waves, among other subjects. Although mechanical experiments have received considerable attention, most of them are based on the use of the accelerometer. An aspect that has received less attention is the use of rotation sensors or gyroscopes. An additional advance in the use of these devices is given by the possibility of obtaining data using the accelerometer and the gyroscope simultaneously. The aim of this paper is to consider the relation between the centripetal acceleration and the angular velocity. Instead of using a formal laboratory setup, in this experiment a smartphone is attached to the floor of a merry-go-round, found in many playgrounds. Several experiments were performed with the roundabout rotating in both directions and with the smart-phone at different distances from the center. The coherence of the measurements is shown.
Varro, S
2006-01-01
The reflection and transmission of a few-cycle femtosecond Ti:Sa laser pulse impinging on a metal nano-layer have been analysed. The thickness of the layer was assumed to be of order of 2-10 nm, and the metallic free electrons were represented by a surface current density distributed at the plane boundary of a dielectric substrate. The target studied this way can be imagined, for instance, as a semi-transparent mirror produced by evapotating a thin aluminum layer on the surface of a glass plate. The exact analytic solution has been given for the system of the coupled Maxwell-Lorentz equations decribing the dynamics of the surface current and the scattered radiation fields. It has been shown that in general a non-oscillatoty frozen-in wake-field appears following the main pulse with an exponential decay and with a definite sign of the electric field. The characteristic time of these wake-fields is inversely proportional with the square of the plasma frequency and with the thickness of the metal nano-layer, and...
Optical design for laser Doppler angular encoder with sub-nanoradian sensitivity
Energy Technology Data Exchange (ETDEWEB)
Shu, D.; Alp, E.E.; Barraza, J.; Kuzay, T.M.; Mooney, T.
1997-09-01
A novel laser angular encoder system has been developed based on the principles of radar, the Doppler effect, optical heterodyning, and self aligning multiple reflection optics. Using this novel three dimensional multiple reflection optical path, a 10 to 20 times better resolution has been reached compared to commercially available laser Doppler displacement meters or laser interferometer systems. With the new angular encoder, sub-nanoradian resolution has been attained in the 8 degree measuring range in a compact setup about 60 mm (H) x 150 mm (W) x 370 mm (L) in size for high energy resolution applications at the Advanced Photon Source undulator beamline 3-ID.
The difficulty of measuring orbital angular momentum
Preece, D; Nieminen, T. A.; Asavei, T.; Heckenberg, N. R.; Rubinsztein-Dunlop, H.
2011-01-01
Light can carry angular momentum as well as energy and momentum; the transfer of this angular momentum to an object results in an optical torque. The development of a rotational analogue to the force measurement capability of optical tweezers is hampered by the difficulty of optical measurement of orbital angular momentum. We present an experiment with encouraging results, but emphasise the difficulty of the task.
The difficulty of measuring orbital angular momentum
Directory of Open Access Journals (Sweden)
D. Preece
2011-09-01
Full Text Available Light can carry angular momentum as well as energy and momentum; the transfer of this angular momentum to an object results in an optical torque. The development of a rotational analogue to the force measurement capability of optical tweezers is hampered by the difficulty of optical measurement of orbital angular momentum. We present an experiment with encouraging results, but emphasise the difficulty of the task.
Photoionization with Orbital Angular Momentum Beams
Picón, A.; Mompart, J.; de Aldana, J. R. Vázquez; Plaja, L.; Calvo, G. F.; Roso, L.
2010-01-01
Intense laser ionization expands Einstein's photoelectric effect rules giving a wealth of phenomena widely studied over the last decades. In all cases, so far, photons were assumed to carry one unit of angular momentum. However it is now clear that photons can possess extra angular momentum, the orbital angular momentum (OAM), related to their spatial profile. We show a complete description of photoionization by OAM photons, including new selection rules involving more than one unit of angula...
Quantum formulation of fractional orbital angular momentum
Götte, Jörg B; Franke-Arnold, Sonja; Zambrini, Roberta; Barnett, Stephen M.
2007-01-01
The quantum theory of rotation angles (S. M. Barnett and D. T. Pegg, Phys. Rev. A, 41, 3427-3425 (1990)) is generalised to non-integer values of the orbital angular momentum. This requires the introduction of an additional parameter, the orientation of a phase discontinuity associated with fractional values of the orbital angular momentum. We apply our formalism to the propagation of light modes with fractional orbital angular momentum in the paraxial and non-paraxial regime.
Orbital angular momentum in phase space
International Nuclear Information System (INIS)
Research highlights: → We propose a comprehensive Weyl-Wigner formalism for the canonical pair angle-angular momentum. → We present a simple and useful toolkit for the practitioner. → We derive simple evolution equations in terms of a star product in the semiclassical limit. - Abstract: A comprehensive theory of the Weyl-Wigner formalism for the canonical pair angle-angular momentum is presented. Special attention is paid to the problems linked to rotational periodicity and angular-momentum discreteness.
Useful angular selectivity in oblique columnar aluminum
Ditchburn, R. J.; Smith, G. B.
1991-03-01
A useful magnitude of angular selective transmittance of incident unpolarized light is demonstrated in obliquely deposited aluminum. Required deposition procedures and anisotropic optical properties are discussed. Angular selectivity is very strong at visible wavelengths but both experiment and theory indicate that a single oblique layer with well defined columns gives high transmittance at near-infrared wavelengths compared with normal films. There are ways of reducing this to enhance the energy control capability. Both solar and luminous angular selectivity are reported.
Korsch, Dietrich
1991-01-01
This is the first book dedicated exclusively to all-reflective imaging systems. It is a teaching tool as well as a practical design tool for anyone who specializes in optics, particularly for those interested in telescopes, infrared, and grazing-incidence systems. The first part of the book describes a unified geometric optical theory of all-reflective imaging systems (from near-normal to grazing incidence) developed from basic principles. The second part discusses correction methods and a multitude of closed-form solutions of well-corrected systems, supplemented with many conventional and unc
Angular Anisotropy and Mass Asymmetry of Thorium-232 Fission Fragments
International Nuclear Information System (INIS)
A large number of experimental and theoretical papers on the angular distribution of the fission fragments of nuclei indicate that it is satisfactorily described by the parameters of the fissioning nucleus at the saddle point. The problem of the effect of these parameters on the distribution of the fragments according to mass has as yet found no generally accepted solution. It remains unclear to what extent the 'good' quantum numbers characteristic of the nucleus at the saddle point remain equally ''good'' when the nucleus passes from the saddle point to the moment of breakdown. If at the saddle point the nucleus has a set of different configurations, this must be apparent in some way in the distribution of the fragments by mass and in their angular distribution (via the moment of inertia of the nucleus). The paper investigates the angular anisotropy of fragments with different masses in the fission of thorium-232 by fast neutrons. The masses of the fragments were determined by simultaneous recording of the kinetic energy of paired fragments in a double ionization chamber with grids. The direction of flight of the fragments was determined using a mechanical collimator. The neutrons causing fission had an extended spectrum, but the contribution of fissions via the (n, n'f) reaction did not exceed a few per cent. The fragments were sorted out according to energy by a two-dimensional 128 x 128 channel analyser with a memory on ferrite. The dependence of angular anisotropy on the mass of the fragments and on their kinetic energy with fixed mass is discussed. The first dependence makes it possible to judge the degree to which the saddle point affects the distribution of the fragments according to mass, while the second gives information about the degree to which the configuration of the nucleus at the moment of breakdown affects the angular anisotropy of the fragments. (author)
The role of angular momentum conservation law in statistical mechanics
Directory of Open Access Journals (Sweden)
I.M. Dubrovskii
2008-12-01
Full Text Available Within the limits of Khinchin ideas [A.Y. Khinchin, Mathematical Foundation of Statistical Mechanics. NY, Ed. Dover, 1949] the importance of momentum and angular momentum conservation laws was analyzed for two cases: for uniform magnetic field and when magnetic field is absent. The law of momentum conservation does not change the density of probability distribution in both cases, just as it is assumed in the conventional theory. It is shown that in systems where the kinetic energy depends only on particle momenta canonically conjugated with Cartesian coordinates being their diagonal quadric form,the angular momentum conservation law changes the density of distribution of the system only in case the full angular momentum of a system is not equal to zero. In the gas of charged particles in a uniform magnetic field the density of distribution also varies if the angular momentum is zero [see Dubrovskii I.M., Condensed Matter Physics, 2206, 9, 23]. Two-dimensional gas of charged particles located within a section of an endless strip filled with gas in magnetic field is considered. Under such conditions the angular momentum is not conserved. Directional particle flows take place close to the strip boundaries, and, as a consequence, the phase trajectory of the considered set of particles does not remain within the limited volume of the phase space. In order to apply a statistical thermodynamics method, it was suggested to consider near-boundary trajectories relative to a reference system that moves uniformly. It was shown that if the diameter of an orbit having average thermal energy is much smaller than a strip width, the corrections to thermodynamic functions are small depending on magnetic field. Only the average velocity of near-boundary particles that form near-boundary electric currents creating the paramagnetic moment turn out to be essential.
The Angular Momentum of the Solar System
Cang, Rongquin; Guo, Jianpo; Hu, Juanxiu; He, Chaoquiong
2016-05-01
The angular momentum of the Solar System is a very important physical quantity to the formation and evolution of the Solar System. Previously, the spin angular momentum of the Sun and the orbital angular momentum of the Eight Giant Planets were only taken into consideration, when researchers calculated the angular momentum of the Solar System. Nowadays, it seems narrow and conservative. Using Eggleton's code, we calculate the rotational inertia of the Sun. Furthermore, we obtain that the spin angular momentum of the Sun is 1.8838 x 10^41 kg m^2 s^-1. Besides the spin angular momentum of the Sun and the orbital angular momentum of the Eight Giant Planets, we also account for the orbital angular momentum of the Asteroid Belt, the Kuiper Belt, the Oort Cloud, the Ninth Giant Planet and the Solar Companion. We obtain that the angular momentum of the whole Solar System is 3.3212 x 10^45 kg m^2 s^-1.
Polarized reflectance and transmittance distribution functions of the ocean surface.
Hieronymi, Martin
2016-07-11
Two aspects of ocean modelling are treated: representation of ocean waves considering all size-classes of waves and tracing of light-interactions at the wavy sea surface. Nonlinear wave profiles are realized accounting for a wide range of climatologically relevant sea states and wind speeds. Polarized ray tracing is used to investigate air-incident and whitecap-free reflectance and transmittance distributions with high angular resolution subject to sea-characterizing parameters, such as significant wave height, peak wave period, wind speed, and surface roughness. Wave-shadowing effects of incident and multiple reflected rays are fully considered. Their influence mostly starts with incidence angles greater than 60°, i.e., when the sun is near the horizon, and is especially pronounced for steep sea states. The net effect of multiple reflections is a redistribution of reflectance and transmittance fractions in their respective hemispheres and a slight increase of the net transmission of light into the sea. Revised reflectance and transmittance distribution functions, RDF and TDF, are provided depending on surface roughness in terms of the mean-square slope; reference is made to other sea state parameters. In comparison with the slope statistics approach, uncertainties related to sun near the horizon are reduced and on average this study yields somewhat higher reflectance values with some variability related to the sea state. By means of provided data, irradiance and radiance reflectances can be computed using desired sky radiance distributions, e.g., clear sky, overcast or partly cloudy sky, as well as wind or sea state information including wave propagation direction. PMID:27410893
Semiclassical model for attosecond angular streaking.
Smolarski, M; Eckle, P; Keller, U; Dörner, R
2010-08-16
Attosecond angular streaking is a new technique to achieve unsurpassed time accuracy of only a few attoseconds. Recently this has been successfully used to set an upper limit on the electron tunneling delay time in strong laser field ionization. The measurement technique can be modeled with either the time-dependent Schrödinger equation (TDSE) or a more simple semiclassical approach that describes the process in two steps in analogy to the three-step model in high harmonic generation (HHG): step one is the tunnel ionization and step two is the classical motion in the strong laser field. Here we describe in detail a semiclassical model which is based on the ADK theory for the tunneling step, with subsequent classical propagation of the electron in the laser field. We take into account different ellipticities of the laser field and a possible wavelength-dependent ellipticity that is typically observed for pulses in the two-optical-cycle regime. This semiclassical model shows excellent agreement with the experimental result. PMID:20721150
Energy Technology Data Exchange (ETDEWEB)
Sharkey, Michael A.; Oliveira, Tânia F.; Engel, Paul C.; Khan, Amir R. [Trinity; (FCT/UNL); (UC-Dublin)
2013-09-05
Glutamate dehydrogenases catalyse the oxidative deamination of _{L}-glutamate to α-ketoglutarate, using NAD^{+} and/or NADP^{+} as a cofactor. Subunits of homo-hexameric bacterial enzymes comprise a substrate-binding domain I followed by a nucleotide-binding domain II. The reaction occurs in a catalytic cleft between the two domains. Although conserved residues in the nucleotide-binding domains of various dehydrogenases have been linked to cofactor preferences, the structural basis for specificity in the GDH family remains poorly understood. Here, the refined crystal structure of Escherichia coli GDH in the absence of reactants is described at 2.5-Å resolution. Modelling of NADP^{+} in domain II reveals the potential contribution of positively charged residues from a neighbouring α-helical hairpin to phosphate recognition. In addition, a serine that follows the P7 aspartate is presumed to form a hydrogen bond with the 2'-phosphate. Mutagenesis and kinetic analysis confirms the importance of these residues in NADP^{+} recognition. Surprisingly, one of the positively charged residues is conserved in all sequences of NAD^{+}-dependent enzymes, but the conformations adopted by the corresponding regions in proteins whose structure has been solved preclude their contribution to the coordination of the 2'-ribose phosphate of NADP^{+}. These studies clarify the sequence–structure relationships in bacterial GDHs, revealing that identical residues may specify different coenzyme preferences, depending on the structural context. Primary sequence alone is therefore not a reliable guide for predicting coenzyme specificity. We also consider how it is possible for a single sequence to accommodate both coenzymes in the dual-specificity GDHs of animals.
The role of angular momentum conservation law in statistical mechanics
I.M. Dubrovskii
2008-01-01
Within the limits of Khinchin ideas [A.Y. Khinchin, Mathematical Foundation of Statistical Mechanics. NY, Ed. Dover, 1949] the importance of momentum and angular momentum conservation laws was analyzed for two cases: for uniform magnetic field and when magnetic field is absent. The law of momentum conservation does not change the density of probability distribution in both cases, just as it is assumed in the conventional theory. It is shown that in systems where the kinetic energy depends onl...
Parton Transverse Momentum and Orbital Angular Momentum Distributions
Rajan, Abha; Courtoy, Aurore; Engelhardt, Michael; Liuti, Simonetta
2016-01-01
The quark orbital angular momentum component of proton spin, $L_q$, can be defined in QCD as the integral of a Wigner phase space distribution weighting the cross product of the quark's transverse position and momentum. It can also be independently defined from the operator product expansion for the off-forward Compton amplitude in terms of a twist-three generalized parton distribution. We provide an explicit link between the two definitions, connecting them through their dependence on parton...
The orbital angular momentum of down-converted photons
Energy Technology Data Exchange (ETDEWEB)
Ren Xifeng; Guo Guoping; Yu Bo; Li Jian; Guo Guangcan [Key Laboratory of Quantum Information, University of Science and Technology of China, CAS, Hefei 230026 (China)
2004-04-01
We calculate the relative amplitude of the orbital angular momentum (OAM) of entangled photon pairs from the spontaneous parametric down-conversion of a thin quadratic nonlinear crystal. The results show that the amplitude depends on both of the two Laguerre indices l, p. We also discuss the influences of the commonly used holograms and mono-mode fibres for mode analysis. We conclude that only a few dimensions can be explored from the infinite OAM modes of down-converted photon pairs.
Dynamic interferometry measurement of orbital angular momentum of light
Jianji, Dong; Hailong, Zhou; Xinliang, Zhang
2014-01-01
We present a dynamic interferometry to measure the orbital angular momentum (OAM) of beams. An opaque screen with two air slits is employed, which can be regarded as the Youngs double-pinhole interference. When the OAM beams with an annular intensity distribution vertically incident, the far-field interference patterns depend on the phase difference of the light in the two pinholes. We scan the angle between the two slits, the output intensity at center changes alternatively between darkness ...
Langmuir monolayers on water surface investigated by X-ray total reflection fluorescence
International Nuclear Information System (INIS)
Langmuir monolayers of metal-rich phthalocyanines (Pc) and phospholipid at air/water interface have been studied by X-ray total reflection fluorescence at SR beam line ID 10B (ESRF). Experimental fluorescence angular dependences from 'heavy' ions of a monolayer alone on water surface modulated by evanescent wave/X-ray standing wave pattern have been detected for the first time, are in good agreement with calculations and provide information about the position of metal ions in organic molecule with respect to water surface
Langmuir monolayers on water surface investigated by X-ray total reflection fluorescence
Energy Technology Data Exchange (ETDEWEB)
Zheludeva, S.I.; Novikova, N.N.; Konovalov, O.V.; Kovalchuk, M.V.; Stepina, N.D.; Tereschenko, E.Yu
2003-10-15
Langmuir monolayers of metal-rich phthalocyanines (Pc) and phospholipid at air/water interface have been studied by X-ray total reflection fluorescence at SR beam line ID 10B (ESRF). Experimental fluorescence angular dependences from 'heavy' ions of a monolayer alone on water surface modulated by evanescent wave/X-ray standing wave pattern have been detected for the first time, are in good agreement with calculations and provide information about the position of metal ions in organic molecule with respect to water surface.
The angular two-point correlation of NVSS galaxies revisited
Chen, Song
2015-01-01
We measure the angular two-point correlation and angular power spectrum from the NRAO VLA Sky Survey (NVSS) of radio galaxies. Contrary to previous claims in the literature, we show that it is consistent with primordial Gaussianity on all angular scales and it is consistent with the best-fit cosmological model from the Planck analysis, as well as the redshift distribution obtained from the Combined EIS-NVSS Survey Of Radio Sources (CENSORS). Our analysis is based on an optimal estimation of the two-point correlation function and makes use of a new mask, which takes into account direction dependent effects of the observations, side lobe effects of bright sources and galactic foreground. We also use a lower flux threshold and take the cosmic radio dipole into account. The latter turns out to be an essential step in the analysis. This improved cosmological analysis of the NVSS stresses the importance of a flux calibration that is robust and stable on large angular scales for future radio continuum surveys.
Angular and linear accelerations of a rolling cylinder acted by an external force
Energy Technology Data Exchange (ETDEWEB)
Oliveira, V, E-mail: voliveira@isel.ipl.pt [Instituto Superior Engenharia de Lisboa, Avenida Conselheiro Emidio Navarro no 1, 1959-007 Lisboa (Portugal)
2011-03-15
The dynamics of a cylinder rolling on a horizontal plane acted on by an external force applied at an arbitrary angle is studied with emphasis on the directions of the acceleration of the centre-of-mass and the angular acceleration of the body. If rolling occurs without slipping, there is a relationship between the directions of these accelerations. If the linear acceleration points to the right, then the angular acceleration is clockwise. On the other hand, if it points to the left, then the angular acceleration is counterclockwise. In contrast, if rolling and slipping occurs, the direction of the linear acceleration does not determine the direction of the angular acceleration. For example, the linear acceleration may point to the right and the angular acceleration clockwise or counterclockwise depending on the external force orientation and point of application.
Measurement of anisotropic reflection of flowing blood using optical coherence tomography
Nam, Kweon-Ho; Jeong, Bosu; Jung, In Oh; Ha, Hojin; Kim, Ki Hean; Lee, Sang Joon
2011-12-01
Light reflectance of blood is a complex phenomenon affected by hematocrit and red blood cell (RBC) aggregation (rouleaux formation). According to the hypothesis that RBC rouleaux are aligned with the direction of blood flow, the spatial alignment of RBC rouleaux, as well as their size and quantity in the blood, may also affect light reflectance. The present study aims to investigate the effect of the spatial alignment and distribution of RBC rouleaux on light reflection using optical coherence tomography (OCT). Blood flow velocity and reflectance profiles in a rat jugular-femoral bypass loop were simultaneously measured using a Doppler swept-source OCT system at various incident angles from -30 to +30 deg. The reflectance profiles of flowing blood show nonmonotonous decay with a local negative peak at the center of the tube. The profiles vary depending on the incident angle. This angular dependence is stronger at a higher angle of incidence. The anisotropic reflectance of flowing blood is consistent with the hypothesis on the spatial alignment of RBC rouleaux.
Transverse and longitudinal angular momenta of light
International Nuclear Information System (INIS)
We review basic physics and novel types of optical angular momentum. We start with a theoretical overview of momentum and angular momentum properties of generic optical fields, and discuss methods for their experimental measurements. In particular, we describe the well-known longitudinal (i.e., aligned with the mean momentum) spin and orbital angular momenta in polarized vortex beams. Then, we focus on the transverse (i.e., orthogonal to the mean momentum) spin and orbital angular momenta, which were recently actively discussed in theory and observed in experiments. First, the recently-discovered transverse spin angular momenta appear in various structured fields: evanescent waves, interference fields, and focused beams. We show that there are several kinds of transverse spin angular momentum, which differ strongly in their origins and physical properties. We describe extraordinary features of the transverse optical spins and overview recent experiments. In particular, the helicity-independent transverse spin inherent in edge evanescent waves offers robust spin–direction coupling at optical interfaces (the quantum spin Hall effect of light). Second, we overview the transverse orbital angular momenta of light, which can be both extrinsic and intrinsic. These two types of the transverse orbital angular momentum are produced by spatial shifts of the optical beams (e.g., in the spin Hall effect of light) and their Lorentz boosts, respectively. Our review is underpinned by a unified theory of the angular momentum of light based on the canonical momentum and spin densities, which avoids complications associated with the separation of spin and orbital angular momenta in the Poynting picture. It allows us to construct a comprehensive classification of all known optical angular momenta based on their key parameters and main physical properties
Transverse and longitudinal angular momenta of light
Energy Technology Data Exchange (ETDEWEB)
Bliokh, Konstantin Y., E-mail: k.bliokh@gmail.com [Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Nonlinear Physics Centre, RSPhysE, The Australian National University, Canberra, ACT 0200 (Australia); Nori, Franco [Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, MI 48109-1040 (United States)
2015-08-26
We review basic physics and novel types of optical angular momentum. We start with a theoretical overview of momentum and angular momentum properties of generic optical fields, and discuss methods for their experimental measurements. In particular, we describe the well-known longitudinal (i.e., aligned with the mean momentum) spin and orbital angular momenta in polarized vortex beams. Then, we focus on the transverse (i.e., orthogonal to the mean momentum) spin and orbital angular momenta, which were recently actively discussed in theory and observed in experiments. First, the recently-discovered transverse spin angular momenta appear in various structured fields: evanescent waves, interference fields, and focused beams. We show that there are several kinds of transverse spin angular momentum, which differ strongly in their origins and physical properties. We describe extraordinary features of the transverse optical spins and overview recent experiments. In particular, the helicity-independent transverse spin inherent in edge evanescent waves offers robust spin–direction coupling at optical interfaces (the quantum spin Hall effect of light). Second, we overview the transverse orbital angular momenta of light, which can be both extrinsic and intrinsic. These two types of the transverse orbital angular momentum are produced by spatial shifts of the optical beams (e.g., in the spin Hall effect of light) and their Lorentz boosts, respectively. Our review is underpinned by a unified theory of the angular momentum of light based on the canonical momentum and spin densities, which avoids complications associated with the separation of spin and orbital angular momenta in the Poynting picture. It allows us to construct a comprehensive classification of all known optical angular momenta based on their key parameters and main physical properties.
Angular-Rate Estimation using Star Tracker Measurements
Azor, R.; Bar-Itzhack, Itzhack Y.; Deutschmann, Julie K.; Harman, Richard R.
1999-01-01
This paper presents algorithms for estimating the angular-rate vector of satellites using quaternion measurements. Two approaches are compared, one that uses differentiated quaternion measurements to yield coarse rate measurements which are then fed into two different estimators. In the other approach the raw quaternion measurements themselves are fed directly into the two estimators. The two estimators rely on the ability to decompose the non-linear rate dependent part of the rotational dynamics equation of a rigid body into a product of an angular-rate dependent matrix and the angular-rate vector itself. This decomposition, which is not unique, enables the treatment of the nonlinear spacecraft dynamics model as a linear one and, consequently, the application of a Pseudo-Linear Kalman Filter (PSELIKA). It also enables the application of a special Kalman filter which is based on the use of the solution of the State Dependent Algebraic Riccati Equation (SDARE) in order to compute the Kalman gain matrix and thus eliminates the need to propagate and update the filter covariance matrix. The replacement of the elaborate rotational dynamics by a simple first order Markov model is also examined. In this paper a special consideration is given to the problem of delayed quaternion measurements. Two solutions to this problem are suggested and tested. Real Rossi X-Ray Timing Explorer (RXTE) data is used to test these algorithms, and results of these tests are presented.
Raz, Gal; Jacob, Yael; Gonen, Tal; Winetraub, Yonatan; Flash, Tamar; Soreq, Eyal; Hendler, Talma
2014-01-01
Two empathy-related processes were recently distinguished neuroscientifically: automatic embodied-simulation (ES) based on visceromotor representation of another's affective state via cingulo-insulary circuit, and emotional sharing relying on cognitive 'theory of mind' (ToM) via prefrontal-temporo-parietal circuit. Evidence that these regions are not only activated but also function as networks during empathic experience has yet to been shown. Employing a novel approach by analyzing fMRI fluctuations of network cohesion while viewing films portraying personal loss, this study demonstrates increased connectivity during empathic engagement (probed by behavioral and parasympathetic indices) both within these circuits, and between them and a set of limbic regions. Notably, this effect was context-dependent: when witnessing as a determined-loss presented as a future event, the ToM and ToM-limbic cohesion positively correlated with state- and empathy indices. During the dramatic peak of this condition, the ToM cohesion was positively correlated with the trait-empathy index of personal distress. However, when the loss was presented as a probabilistic real-time occurrence, ToM cohesion negatively correlated with state-empathy index, which positively correlated with ES-limbic cohesion. In this case, it was the ES-limbic cohesion during the emotional peak which was correlated with personal distress scores. The findings indicate a dichotomy between regulated empathy toward determined-loss and vicarious empathy toward a real-time occurrence. PMID:23615766
Experimental determination of high angular momentum states
International Nuclear Information System (INIS)
The current knowledge of the atomic nucleus structure is summarized. A short abstract of the nuclear properties at high angular momentum and a more detailed description of the experimental methods used in the study of high angular momenta is made. (L.C.)
Orbital Angular Momentum in the Nucleon
Garvey, Gerald T.
2010-01-01
Analysis of the measured value of the integrated \\bar{d}-\\bar{u} asymmetry (Ifas = 0.147+-0.027) in the nucleon show it to arise from nucleon fluctuations into baryon plus pion. Requiring angular momentum conservation in these fluctuations shows the associated orbital angular momentum is equal to the value of the flavor asymmetry.
Detecting orbital angular momentum in radio signals
Then, H.; Thidé, B.; Mendonça, J T; Carozzi, T.D.; Bergman, J.; Baan, W. A.; Mohammadi, S. (Siawoosh); Eliasson, B.
2008-01-01
Electromagnetic waves with an azimuthal phase shift are known to have a well defined orbital angular momentum. Different methods that allow for the detection of the angular momentum are proposed. For some, we discuss the required experimental setup and explore the range of applicability.
The Orbital Angular Momentum Sum Rule
Aslan, Fatma; Burkardt, Matthias
2015-10-01
As an alternative to the Ji sum rule for the quark angular momentum, a sum rule for the quark orbital angular momentum, based on a twist-3 generalized parton distribution, has been suggested. We study the validity of this sum rule in the context of scalar Yukawa interactions as well as in QED for an electron.
Responsive web design with AngularJS
Patel, Sandeep Kumar
2014-01-01
If you are an AngularJS developer who wants to learn about responsive web application development, this book is ideal for you. Responsive Web Design with AngularJS is intended for web developers or designers with a basic knowledge of HTML, CSS, and JavaScript.
Exposing Library Services with AngularJS
Jakob Voß; Moritz Horn
2014-01-01
This article provides an introduction to the JavaScript framework AngularJS and specific AngularJS modules for accessing library services. It shows how information such as search suggestions, additional links, and availability can be embedded in any website. The ease of reuse may encourage more libraries to expose their services via standard APIs to allow usage in different contexts.
Angular-Rate Estimation Using Quaternion Measurements
Azor, Ruth; Bar-Itzhack, Y.; Deutschmann, Julie K.; Harman, Richard R.
1998-01-01
In most spacecraft (SC) there is a need to know the SC angular rate. Precise angular rate is required for attitude determination, and a coarse rate is needed for attitude control damping. Classically, angular rate information is obtained from gyro measurements. These days, there is a tendency to build smaller, lighter and cheaper SC, therefore the inclination now is to do away with gyros and use other means and methods to determine the angular rate. The latter is also needed even in gyro equipped satellites when performing high rate maneuvers whose angular-rate is out of range of the on board gyros or in case of gyro failure. There are several ways to obtain the angular rate in a gyro-less SC. When the attitude is known, one can differentiate the attitude in whatever parameters it is given and use the kinematics equation that connects the derivative of the attitude with the satellite angular-rate and compute the latter. Since SC usually utilize vector measurements for attitude determination, the differentiation of the attitude introduces a considerable noise component in the computed angular-rate vector.
Angular momentum decomposition of Richardson's pairs
International Nuclear Information System (INIS)
The angular momentum decomposition of pairs obtained using Richardson's exact solution of the pairing Hamiltonian for the deformed 174Yb nucleus are displayed. The probabilities for low angular momenta of the collective pairs are strikingly different from the ones obtained in the BCS ground state
Quark angular momentum in a spectator model
International Nuclear Information System (INIS)
We investigate the quark angular momentum in a model with the nucleon being a quark and a spectator. Both scalar and axial-vector spectators are included. We perform the calculations in the light-cone formalism where the parton concept is well defined. We calculate the quark helicity and canonical orbital angular momentum. Then we calculate the gravitational form factors which are often related to the kinetic angular momentums, and find that even in a no gauge field model we cannot identify the canonical angular momentums with half the sum of gravitational form factors. In addition, we examine the model relation between the orbital angular momentum and pretzelosity, and find it is violated in the axial-vector case
Quark angular momentum in a spectator model
Directory of Open Access Journals (Sweden)
Tianbo Liu
2015-02-01
Full Text Available We investigate the quark angular momentum in a model with the nucleon being a quark and a spectator. Both scalar and axial-vector spectators are included. We perform the calculations in the light-cone formalism where the parton concept is well defined. We calculate the quark helicity and canonical orbital angular momentum. Then we calculate the gravitational form factors which are often related to the kinetic angular momentums, and find that even in a no gauge field model we cannot identify the canonical angular momentums with half the sum of gravitational form factors. In addition, we examine the model relation between the orbital angular momentum and pretzelosity, and find it is violated in the axial-vector case.
Does high harmonic generation conserve angular momentum?
Fleischer, Avner; Diskin, Tzvi; Sidorenko, Pavel; Cohen, Oren
2013-01-01
High harmonic generation (HHG) is a unique and useful process in which infrared or visible radiation is frequency up converted into the extreme ultraviolet and x ray spectral regions. As a parametric process, high harmonic generation should conserve the radiation energy, momentum and angular momentum. Indeed, conservation of energy and momentum have been demonstrated. Angular momentum of optical beams can be divided into two components: orbital and spin (polarization). Orbital angular momentum is assumed to be conserved and recently observed deviations were attributed to propagation effects. On the other hand, conservation of spin angular momentum has thus far never been studied, neither experimentally nor theoretically. Here, we present the first study on the role of spin angular momentum in extreme nonlinear optics by experimentally generating high harmonics of bi chromatic elliptically polarized pump beams that interact with isotropic media. While observing that the selection rules qualitatively correspond...
Physical Angular Momentum Separation for QED
Sun, Weimin
2016-01-01
We study the non-uniqueness problem of the gauge-invariant angular momentum separation for the case of QED, which stems from the recent controversy concerning the proper definitions of the orbital angular momentum and spin operator of the individual parts of a gauge field system. For the free quantum electrodynamics without matter, we show that the basic requirement of Euclidean symmetry selects a unique physical angular momentum separation scheme from the multitude of the possible angular momentum separation schemes constructed using the various Gauge Invariant Extentions. Based on these results, we propose a set of natural angular momentum separation schemes for the case of interacting QED by invoking the formalism of asymptotic fields. Some perspectives on such a problem for the case of QCD are briefly discussed.
Perturbed angular correlations and distributions
International Nuclear Information System (INIS)
The present index comprises original works and review papers on the perturbed angular correlations (PAC) and distributions (PAD). The articles published in the Soviet and foreign journals as well as the materials of conferences, monographs and collections published in the USSR and abroad, the preprints produced by various institutes and abstracts of disertations are included from 1948 up to 1973. The whole material compiled in this index is divided into three parts. Part one is a bibliographic index. All papers in this part are divided into three sections. Section one comprises the papers devoted to the theoretical works on PAC, review papers, monographs, materials of conferences. Section two deals with the works of methodical character where correlation spectrometers as well as the treatment of experimental data are described. In section three experimental works with concrete nuclei are compiled. Part two gives the characteristic of works performed with concrete nuclei. This part is presented in the form of the table in which the works are systematized according to the chemical elements and isotopes. The table shows the characteristics of the nuclear levels used in the investigations by PAC as well as brief characteristics of experiments and results obtained. Part three - appendix contains alphabetic index of the authors, the list of the used editions with the abbreviations of the titles of these editions. The lists indicating the dynamic of the quantity of works on PAC and the distribution according to the literature sources are also given
Ojanen, Teemu
2016-05-01
Recently, it was discovered that the ground-state orbital angular momentum in two-dimensional chiral superfluids with pairing symmetry (px+i py) ν depends on the winding number ν in a striking manner. The ground-state value for the ν =1 case is Lz=ℏ N /2 as expected by counting the Cooper pairs, while a dramatic cancellation takes place for ν >1 . The origin of the cancellation is associated with the topological edge states that appear in a finite geometry and give rise to a spectral asymmetry. Here, we study the reduction of orbital angular momentum for different potential profiles and pairing strengths, showing that the result Lz=ℏ N /2 is robust for ν =1 under all studied circumstances. We study how angular momentum depends on the gap size Δ /EF and obtain the result Lz=ℏ/ν 2 N (1 -μ/EF) for ν =2 ,3 . Thus, the gap dependence of Lz for ν <4 enters at most through the chemical potential while ν ≥4 is qualitatively different. In addition, we generalize the spectral asymmetry arguments to total angular momentum in the ground state of triplet superfluids where due to a spin-orbit coupling Lz is not a good quantum number. We find that the ground-state total angular momentum also behaves very differently depending on total angular momentum of the Cooper pairs.
Modelling of atmospheric effects on the angular distribution of a backscattering peak
International Nuclear Information System (INIS)
If off-nadir satellite sensing of vegetative surfaces is considered, understanding the angular distribution of the radiance exiting the atmosphere in all upward directions is of interest. Of particular interest is the discovery of those reflectance features which are invariant to atmospheric perturbations. When mono-directional radiation is incident on a vegetative scene a characteristic angular signature called the hot-spot is produced in the solar retro-direction. The remotely sensed hot-spot is modified by atmospheric extinction of the direct and reflected solar radiation, atmospheric backscattering, and the diffuse sky irradiance incident on the surface. It is demonstrated, however, by radiative transfer calculations through model atmospheres that at least one parameter which characterizes the canopy hot-spot, namely its angular half width, is invariant to atmospheric perturbations. 7 refs., 4 figs., 1 tab
Theoretical Manifestation of the Broadening Effect on Photoelectron Angular Distributions
Institute of Scientific and Technical Information of China (English)
ZHANG Jing-Tao(张敬涛); ZHOU Lan(周岚); ZHANG Wen-Qi(张文琦); XU Zhi-Zhan(徐至展); GUO Dong-Sheng(郭东升); R.R.Freeman
2003-01-01
The broadening effect in photoelectron angular distributions (PADs) observed by Freeman et al. Is studied theoretically. Using a nonperturbative scattering theory developed for multiphoton ionization with the inclusion of spontaneous emission, we calculate the PADs for above-threshold ionization (ATI) peaks. The numerical calculations from our theory reproduce the kinetic-energy dependence and the laser-intensity dependence of PADs of ATI peaks observed by Freeman et al., [Phys. Rev. Lett. 57 (1986) 3156] and provide an evidence for the existence of the ponderomotive momentum of intense laser fields.
Analytical model for CMB temperature angular power spectrum from cosmic (super-)strings
Yamauchi, Daisuke; Takahashi, Keitaro; Sendouda, Yuuiti; Yoo, Chul-Moon; Sasaki, Misao
2010-01-01
We present a new analytical method to calculate the small angle CMB temperature angular power spectrum due to cosmic (super-)string segments. In particular, using our method, we clarify the dependence on the intercommuting probability $P$. We find that the power spectrum is dominated by Poisson-distributed string segments. The power spectrum for a general value of $P$ has a plateau on large angular scales and shows a power-law decrease on small angular scales. The resulting spectrum in the ca...
Is photon angular momentum important in molecular collision processes occurring in a laser field
Devries, P. L.; George, T. F.
1978-01-01
The importance of the rigorous treatment of photon angular momentum in molecular-collision processes occurring in the presence of intense radiation is investigated. An alternate approximate treatment, which essentially neglects the angular momentum coupling between the photon and the molecular degrees of freedom by averaging over the angular dependence of the interaction matrix elements, is presented and applied to a model calculation. The degeneracy-averaged results of this calculation compare remarkably well with the results of a rigorous calculation, from which we conclude (with reservation) that the explicit consideration of photoangular momentum coupling in molecular-collision problems is unnecessary.
Angular-Rate Estimation Using Delayed Quaternion Measurements
Azor, R.; Bar-Itzhack, I. Y.; Harman, R. R.
1999-01-01
This paper presents algorithms for estimating the angular-rate vector of satellites using quaternion measurements. Two approaches are compared one that uses differentiated quaternion measurements to yield coarse rate measurements, which are then fed into two different estimators. In the other approach the raw quaternion measurements themselves are fed directly into the two estimators. The two estimators rely on the ability to decompose the non-linear part of the rotas rotational dynamics equation of a body into a product of an angular-rate dependent matrix and the angular-rate vector itself. This non unique decomposition, enables the treatment of the nonlinear spacecraft (SC) dynamics model as a linear one and, thus, the application of a PseudoLinear Kalman Filter (PSELIKA). It also enables the application of a special Kalman filter which is based on the use of the solution of the State Dependent Algebraic Riccati Equation (SDARE) in order to compute the gain matrix and thus eliminates the need to compute recursively the filter covariance matrix. The replacement of the rotational dynamics by a simple Markov model is also examined. In this paper special consideration is given to the problem of delayed quaternion measurements. Two solutions to this problem are suggested and tested. Real Rossi X-Ray Timing Explorer (RXTE) data is used to test these algorithms, and results are presented.
Evaluation of BRDF Archetypes for Representing Surface Reflectance Anisotropy Using MODIS BRDF Data
Hu Zhang; Ziti Jiao; Yadong Dong; Xiaowen Li
2015-01-01
Bidirectional reflectance distribution function (BRDF) archetypes extracted from the Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF/Albedo product over the global Earth Observing System Land Validation Core Sites can be used to simplify BRDF models. The present study attempts to evaluate the representativeness of BRDF archetypes for surface reflectance anisotropy. Five-year forward-modeled MODIS multi-angular reflectance (MCD-ref) and aditional actual MODIS multi-angular observat...
State-selective velocity and angular distributions of NO molecules scattered from a graphite surface
Energy Technology Data Exchange (ETDEWEB)
Hager, J.; Shen, Y.R.; Walther, H.
1985-03-01
Laser ionization was used to measure the state-selective angular and velocity distributions of NO molecules scattered from a graphite surface. The data showed that at sufficiently low surface temperatures, the scattered molecules were generally composed of quasispecular reflected part and a diffusive scattered part with different translational and rotational behavior.
Twist Three Generalized Parton Distributions for Orbital Angular Momentum
Rajan, Abha
2016-01-01
We study the orbital angular momentum contribution to the spin structure of the proton. It is well known that the quark and gluon spin contributions do not add up to the proton spin. We motivate the connection between the Generalized Transverse Momentum Distribution (GTMD) $F_{14}$, and orbital angular momentum by exploring the underlying quark proton helicity amplitude structure. The twist three Generalized Parton Distribution (GPD) $\\tilde{E}_{2T}$, was shown to connect to OAM. We study these functions using a diquark model calculation. The GTMD $F_{14}$ is unique in that it can describe both Jaffe-Manohar and Ji OAM depending on choice of gauge link, i.e. whether final state interactions are included or not. We perform a calculation of $F_{14}$ in both scenarios.
Parton Transverse Momentum and Orbital Angular Momentum Distributions
Rajan, Abha; Engelhardt, Michael; Liuti, Simonetta
2016-01-01
The quark orbital angular momentum component of proton spin, $L_q$, can be defined in QCD as the integral of a Wigner phase space distribution weighting the cross product of the quark's transverse position and momentum. It can also be independently defined from the operator product expansion for the off-forward Compton amplitude in terms of a twist-three generalized parton distribution. We provide an explicit link between the two definitions, connecting them through their dependence on partonic intrinsic transverse momentum. Connecting the definitions provides the key for correlating direct experimental determinations of $L_q$, and evaluations through Lattice QCD calculations. The direct observation of quark orbital angular momentum does not require transverse spin polarization, but can occur using longitudinally polarized targets.
Resolving enantiomers using the optical angular momentum of twisted light.
Brullot, Ward; Vanbel, Maarten K; Swusten, Tom; Verbiest, Thierry
2016-03-01
Circular dichroism and optical rotation are crucial for the characterization of chiral molecules and are of importance to the study of pharmaceutical drugs, proteins, DNA, and many others. These techniques are based on the different interactions of enantiomers with circularly polarized components of plane wave light that carries spin angular momentum (SAM). For light carrying orbital angular momentum (OAM), for example, twisted or helical light, the consensus is that it cannot engage with the chirality of a molecular system as previous studies failed to demonstrate an interaction between optical OAM and chiral molecules. Using unique nanoparticle aggregates, we prove that optical OAM can engage with materials' chirality and discriminate between enantiomers. Further, theoretical results show that compared to circular dichroism, mainly based on magnetic dipole contributions, the OAM analog helical dichroism (HD) is critically dependent on fundamentally different chiral electric quadrupole contributions. Our work opens new venues to study chirality and can find application in sensing and chiral spectroscopy. PMID:26998517
Angular evolution of peripheral heavy ion reactions at intermediate energies
International Nuclear Information System (INIS)
Energy spectra and angular distributions of projectile-like fragments have been measured in the vicinity of the grazing angle for the 40Ar+40Ca and 40Ar+208Pb reactions at 44MeV/nucleon. Measurements of the 40Ar+40Ca system at 27MeV/nucleon and 20Ne+208Pb reaction at 44MeV/nucleon at one angle have also been performed. For fragments with charge and mass close to the projectile numerous deviations from the standard fragmentation model have been observed including rapidly changing shapes of the angular distributions with the fragment mass. Moreover the isotopic distributions and mean fragment velocities are strongly dependent on detection angle. A surface transfer reaction component dominant at the grazing angle can be separated from a second component which cannot be entirely accounted for by a simple fragmentation mechanism
Angular velocity of gravitational radiation from precessing binaries and the corotating frame
Boyle, Michael
2013-01-01
This paper defines an angular velocity for time-dependent functions on the sphere, and applies it to gravitational waveforms from compact binaries. Because it is geometrically meaningful and has a clear physical motivation, the angular velocity is uniquely useful in helping to solve an important---and largely ignored---problem in models of compact binaries: the inverse problem of deducing the physical parameters of a system from the gravitational waves alone. It is also used to define the cor...
Wiltshire, R. J.
2003-01-01
Einstein's equations for a Robertson-Walker fluid source endowed with rotation Einstein's equations for a Robertson-Walker fluid source endowed with rotation are presented upto and including quadratic terms in angular velocity parameter. A family of analytic solutions are obtained for the case in which the source angular velocity is purely time-dependent. A subclass of solutions is presented which merge smoothly to homogeneous rotating and non-rotating central sources. The particular solution...
Form features provide a cue to the angular velocity of rotating objects
Blair, Christopher David; Goold, Jessica; Killebrew, Kyle; Caplovitz, Gideon Paul
2013-01-01
As an object rotates, each location on the object moves with an instantaneous linear velocity dependent upon its distance from the center of rotation, while the object as a whole rotates with a fixed angular velocity. Does the perceived rotational speed of an object correspond to its angular velocity, linear velocities, or some combination of the two? We had observers perform relative speed judgments of different sized objects, as changing the size of an object changes the l...
Diffraction of orbital angular momentum carrying optical beams by a circular aperture.
Ambuj, A; Vyas, R; Singh, S
2014-10-01
Far field diffraction of Laguerre-Gauss vortex (LGV) beams of different angular momentum index by a circular aperture placed at different locations with respect to incident beam waist is studied experimentally. The experiments reveal a surprisingly simple structure for the diffraction pattern and its dependence on the orbital angular momentum index of the incident beam when the aperture size is small compared to the beam radius. PMID:25360906
Observation of Interaction of Spin and Intrinsic Orbital Angular Momentum of Light
Vitullo, Dashiell L. P.; Leary, Cody C.; Gregg, Patrick; Smith, Roger A.; Reddy, Dileep V.; Ramachandran, Siddharth; Raymer, Michael G.
2016-01-01
Spin and intrinsic orbital angular momentum interaction of light is observed, as evidenced by length-dependent rotations of both spatial patterns and optical polarization in an isotropic optical fiber. The distinction between intrinsic and extrinsic orbital angular momentum (as seen in helically coiled fiber) is made clear by controllable excitation of a small number of optical modes in a straight, few-mode fiber.
Nonlinear management of the angular momentum of soliton clusters: Theory and experiment
International Nuclear Information System (INIS)
We demonstrate, both theoretically and experimentally, how to acquire nonlinear control over the angular momentum of a cluster of solitary waves. Our results, stemming from a universal theoretical model, show that the angular momentum can be adjusted by acting on the global energy input in the system. The phenomenon is experimentally ascertained in nematic liquid crystals by observing a power-dependent rotation of a two-soliton ensemble
Polarization resolved angular optical scattering of aerosol particles
Redding, B.; Pan, Y.; Wang, C.; Videen, G.; Cao, Hui
2014-05-01
Real-time detection and identification of bio-aerosol particles are crucial for the protection against chemical and biological agents. The strong elastic light scattering properties of airborne particles provides a natural means for rapid, non-invasive aerosol characterization. Recent theoretical predictions suggested that variations in the polarization dependent angular scattering cross section could provide an efficient means of classifying different airborne particles. In particular, the polarization dependent scattering cross section of aggregate particles is expected to depend on the shape of the primary particles. In order to experimentally validate this prediction, we built a high throughput, sampling system, capable of measuring the polarization resolved angular scattering cross section of individual aerosol particles flowing through an interrogating volume with a single shot of laser pulse. We calibrated the system by comparing the polarization dependent scattering cross section of individual polystyrene spheres with that predicted by Mie theory. We then used the system to study different particles types: Polystyrene aggregates composed 500 nm spheres and Bacillus subtilis (BG, Anthrax simulant) spores composed of elongated 500 nm × 1000 nm cylinder-line particles. We found that the polarization resolved scattering cross section depends on the shape of the constituent elements of the aggregates. This work indicates that the polarization resolved scattering cross section could be used for rapid discrimination between different bio-aerosol particles.
Angular velocity: a new dimension in nuclei
Energy Technology Data Exchange (ETDEWEB)
Diamond, R.M.; Stephens, F.S.
1984-08-09
Nuclei can be studied from their ground states (approx.O(h/2..pi..)) up to angular momenta of order 100 (h/2..pi..), where they are literally pulled apart by centrifugal effects. This range of angular momenta can be viewed as resulting from cranking the nucleus around a rotation axis, where the critical variable is the cranking velocity. The calculated response of nuclei to such an imposed angular velocity corresponds well with recent observations, and includes a rich and varied interplay of collective and single-particle phenomena.
Angular momentum conservation for dynamical black holes
Hayward, Sean A.
2006-01-01
Angular momentum can be defined by rearranging the Komar surface integral in terms of a twist form, encoding the twisting around of space-time due to a rotating mass, and an axial vector. If the axial vector is a coordinate vector and has vanishing transverse divergence, it can be uniquely specified under certain generic conditions. Along a trapping horizon, a conservation law expresses the rate of change of angular momentum of a general black hole in terms of angular momentum densities of ma...
Quartz angular rate sensor for automotive navigation
Energy Technology Data Exchange (ETDEWEB)
Nozoe, Toshiyuki; Ichinose, Toshihiko; Kawasaki, Syusaku; Hatanaka, Masakazu; Kuroda, Keisuke [Matsushita Electronic Components Co. Ltd. (Japan); Yamamoto, Kohji; Ogata, Motoki; Takeno, Shoichi [Fukui Matsushita Electric Co. Ltd. (Japan); Ishihara, Minoru; Ishii, Tadashi; Umeki, Mitoshi [Nihonn Denpa Kogyo Co. Ltd. (Japan)
1999-07-01
Many of the recent automotive navigation systems are introducing an angular rate sensor that detect vehicle yaw in their system due to the advantage of higher accuracy, in addition to a conventional GPS (Global Positioning System) and vehicle speed signals. Though there are a couple of other methods to get a vehicle direction information, the angular rate sensor is the most suitable device as a gyro in accuracy and reliability point of view. Matsushita developed a new compact angular rate sensor using quartz crystal for automotive navigation systems. The sensor's operation is based upon Coriolis force imposed on a vibrating quartz tuning fork. (orig.)
Bouchard, Frédéric; Schulz, Sebastian A; Upham, Jeremy; Karimi, Ebrahim; Boyd, Robert W
2014-01-01
Orbital angular momentum associated with the helical phase-front of optical beams provides an unbounded \\qo{space} for both classical and quantum communications. Among the different approaches to generate and manipulate orbital angular momentum states of light, coupling between spin and orbital angular momentum allows a faster manipulation of orbital angular momentum states because it depends on manipulating the polarisation state of light, which is simpler and generally faster than manipulating conventional orbital angular momentum generators. In this work, we design and fabricate an ultra-thin spin-to-orbital angular momentum converter, based on plasmonic nano-antennas and operating in the visible wavelength range that is capable of converting spin to an arbitrary value of OAM $\\ell$. The nano-antennas are arranged in an array with a well-defined geometry in the transverse plane of the beam, possessing a specific integer or half-integer topological charge $q$. When a circularly polarised light beam traverse...
DEFF Research Database (Denmark)
Blasco, Maribel
2012-01-01
This article explores how the concept of reflexivity is used in intercultural education. Reflexivity is often presented as a key learning goal in acquiring intercultural competence (ICC). Yet, reflexivity can be defined in different ways, and take different forms across time and space, depending on...
DEFF Research Database (Denmark)
Muchie, Mammo
2011-01-01
life is not free from fluctuations, cycles, disruptions, crises and destructions both human and ecological. Innovation research ought to position itself to address environmental, financial and economic crises. The third is innovation research for development by addressing not only poverty erdaication......A numberof Chris Freeman's colleagues were asked to reflect on what they thought describes his life and work in a few words. Some of the colleagues replied including former SPRU students that were taught or supervised by Chris Freeman. Their views on what they thought were Chris Freeman's defining...... contributions have been put together. There are a number of ways to continue Chris Freeman's legacy on innovation research. The first is to build in a critical tradition in the economics of innovation research by introducing fearlessly emancipatory epistemology. Second the economic system that dominates social...
Gravitational waves carrying orbital angular momentum
Bialynicki-Birula, Iwo; Bialynicka-Birula, Zofia
2016-02-01
Spinorial formalism is used to map every electromagnetic wave into the gravitational wave (within the linearized gravity). In this way we can obtain the gravitational counterparts of Bessel, Laguerre-Gauss, and other light beams carrying orbital angular momentum.
The physics of angular momentum radio
Thidé, B; Then, H; Someda, C G; Ravanelli, R A
2014-01-01
Wireless communications, radio astronomy and other radio science applications are mainly implemented with techniques built on top of the electromagnetic linear momentum (Poynting vector) physical layer. As a supplement and/or alternative to this conventional approach, techniques rooted in the electromagnetic angular momentum physical layer have been advocated, and promising results from proof-of-concept radio communication experiments using angular momentum were recently published. This sparingly exploited physical observable describes the rotational (spinning and orbiting) physical properties of the electromagnetic fields and the rotational dynamics of the pertinent charge and current densities. In order to facilitate the exploitation of angular momentum techniques in real-world implementations, we present a systematic, comprehensive theoretical review of the fundamental physical properties of electromagnetic angular momentum observable. Starting from an overview that puts it into its physical context among ...
Angular Momentum Acquisition in Galaxy Halos
Stewart, Kyle R; Bullock, James S; Maller, Ariyeh H; Diemand, Juerg; Wadsley, James; Moustakas, Leonidas A
2013-01-01
We use high-resolution cosmological hydrodynamic simulations to study the angular momentum acquisition of gaseous halos around Milky Way sized galaxies. We find that cold mode accreted gas enters a galaxy halo with ~70% more specific angular momentum than dark matter averaged over cosmic time (though with a very large dispersion). In fact, we find that all matter has a higher spin parameter when measured at accretion than when averaged over the entire halo lifetime, and is well characterized by \\lambda~0.1, at accretion. Combined with the fact that cold flow gas spends a relatively short time (1-2 dynamical times) in the halo before sinking to the center, this naturally explains why cold flow halo gas has a specific angular momentum much higher than that of the halo and often forms "cold flow disks". We demonstrate that the higher angular momentum of cold flow gas is related to the fact that it tends to be accreted along filaments.
Gravitational waves carrying orbital angular momentum
Bialynicki-Birula, Iwo
2015-01-01
Spinorial formalism is used to map every electromagnetic wave into the gravitational wave (within the linearized gravity). In this way we can obtain the gravitational counterparts of Bessel, Laguerre-Gauss, and other light beams carrying orbital angular momentum.
Radiofrequency encoded angular-resolved light scattering
DEFF Research Database (Denmark)
Buckley, Brandon W.; Akbari, Najva; Diebold, Eric D.;
2015-01-01
The sensitive, specific, and label-free classification of microscopic cells and organisms is one of the outstanding problems in biology. Today, instruments such as the flow cytometer use a combination of light scatter measurements at two distinct angles to infer the size and internal complexity...... of cells at rates of more than 10,000 per second. However, by examining the entire angular light scattering spectrum it is possible to classify cells with higher resolution and specificity. Current approaches to performing these angular spectrum measurements all have significant throughput limitations...... Encoded Angular-resolved Light Scattering (REALS), this technique multiplexes angular light scattering in the radiofrequency domain, such that a single photodetector captures the entire scattering spectrum from a particle over approximately 100 discrete incident angles on a single shot basis. As a proof...
ZKDR Distance, Angular Size and Phantom Cosmology
R.C. Santos; Lima, J. A. S.
2006-01-01
The influence of mass inhomogeneities on the angular size-redshift test is investigated for a large class of flat cosmological models driven by dark energy plus a cold dark matter component. The results are presented in two steps. First, the mass inhomogeneities are modeled by a generalized Zeldovich-Kantowski-Dyer-Roeder (ZKDR) distance which is characterized by a smoothness parameter $\\alpha(z)$ and a power index $\\gamma$, and, second, we provide a statistical analysis to angular size data ...
Mastering AngularJD for .NET developers
Majid, Mohammad Wadood
2015-01-01
This book is envisioned for traditional developers and programmers who want to develop client-side applications using the AngularJS framework and ASP.NET Web API 2 with Visual Studio. .NET developers who have already built web applications or web services and who have a fundamental knowledge of HTML, JavaScript, and CSS and want to explore single-page applications will also find this guide useful. Basic knowledge of AngularJS would be helpful.
Shell effects and fission fragments angular anisotropy
International Nuclear Information System (INIS)
The impact of the shell corrections attenuation effect with growth of the fissionable nuclei temperature on the angular anisotropy of the fission fragments is considered. The experimental data on the anisotropy of the fission fragments angular distributions of the compound nucleus, formed in the 4He + 238U reactions, are analyzed within the frames of the transition states model in the fission barriers saddle point and statistic theory of nuclear reactions. The obvious kind of the shell corrections attenuation function is obtained
Integrating rotation and angular velocity from curvature
Saje, Miran; Treven, Anita
2016-01-01
The problem of integrating the rotational vector from a given angular velocity vector is met in such diverse fields as the navigation, robotics, computer graphics, optical tracking and non-linear dynamics of flexible beams. For example, if the numerical formulation of non-linear dynamics of flexible beams is based on the interpolation of curvature, one needs to derive the rotation from the assumed curvature field. The relation between the angular velocity and the rotation is described by the ...