Mapping the magnetic field vector in a fountain clock
Gertsvolf, Marina; Marmet, Louis [National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada)
2011-12-15T23:59:59.000Z
We show how the mapping of the magnetic field vector components can be achieved in a fountain clock by measuring the Larmor transition frequency in atoms that are used as a spatial probe. We control two vector components of the magnetic field and apply audio frequency magnetic pulses to localize and measure the field vector through Zeeman spectroscopy.
Height variation of the vector magnetic field in solar spicules
Suarez, D Orozco; Bueno, J Trujillo
2015-01-01T23:59:59.000Z
Proving the magnetic configuration of solar spicules has hitherto been difficult due to the lack of spatial resolution and image stability during off-limb ground-based observations. We report spectropolarimetric observations of spicules taken in the He I 1083 nm spectral region with the Tenerife Infrared Polarimeter II at the German Vacuum Tower Telescope of the Observatorio del Teide (Tenerife; Canary Islands; Spain). The data provide the variation with geometrical height of the Stokes I, Q, U, and V profiles whose encoded information allows the determination of the magnetic field vector by means of the HAZEL inversion code. The inferred results show that the average magnetic field strength at the base of solar spicules is about 80 gauss and then it decreases rapidly with height to about 30 gauss at a height of 3000 km above the visible solar surface. Moreover, the magnetic field vector is close to vertical at the base of the chromosphere and has mid inclinations (about 50 degree) above 2 Mm height.
Tracking Vector Magnetograms with the Magnetic Induction Equation
P. W. Schuck
2008-07-11T23:59:59.000Z
The differential affine velocity estimator (DAVE) developed in Schuck (2006) for estimating velocities from line-of-sight magnetograms is modified to directly incorporate horizontal magnetic fields to produce a differential affine velocity estimator for vector magnetograms (DAVE4VM). The DAVE4VM's performance is demonstrated on the synthetic data from the anelastic pseudospectral ANMHD simulations that were used in the recent comparison of velocity inversion techniques by Welsch (2007). The DAVE4VM predicts roughly 95% of the helicity rate and 75% of the power transmitted through the simulation slice. Inter-comparison between DAVE4VM and DAVE and further analysis of the DAVE method demonstrates that line-of-sight tracking methods capture the shearing motion of magnetic footpoints but are insensitive to flux emergence -- the velocities determined from line-of-sight methods are more consistent with horizontal plasma velocities than with flux transport velocities. These results suggest that previous studies that rely on velocities determined from line-of-sight methods such as the DAVE or local correlation tracking may substantially misrepresent the total helicity rates and power through the photosphere.
X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in...
Predicting the magnetic vectors within coronal mass ejections arriving at Earth
Savani, N P; Szabo, A; Mays, M L; Thompson, B J; Richardson, I G; Evans, R; Pulkkinen, A; Nieves-Chinchilla, T
2015-01-01T23:59:59.000Z
The process by which the Sun affects the terrestrial environment on short timescales is predominately driven by the amount of magnetic reconnection between the solar wind and Earth's magnetosphere. Reconnection occurs most efficiently when the solar wind magnetic field has a southward component. The most severe impacts are during the arrival of a coronal mass ejection (CME) when the magnetosphere is both compressed and magnetically connected to the heliospheric environment, leading to disruptions to, for example, power grids and satellite navigation. Unfortunately, forecasting magnetic vectors within coronal mass ejections remains elusive. Here we report how, by combining a statistically robust helicity rule for a CME's solar origin with a simplified flux rope topology the magnetic vectors within the Earth-directed segment of a CME can be predicted. In order to test the validity of this proof-of-concept architecture for estimating the magnetic vectors within CMEs, a total of eight CME events (between 2010 and...
GravitoMagnetic Field in Tensor-Vector-Scalar Theory
Exirifard, Qasem, E-mail: exir@theory.ipm.ac.ir [Institute for Research in Fundamental Sciences (IPM), Tehran (Iran, Islamic Republic of)
2013-04-01T23:59:59.000Z
We study the gravitomagnetism in the TeVeS theory. We compute the gravitomagnetic field that a slow moving mass distribution produces in its Newtonian regime. We report that the consistency between the TeVeS gravitomagnetic field and that predicted by the Einstein-Hilbert theory leads to a relation between the vector and scalar coupling constants of the theory. We translate the Lunar Laser Ranging measurement's data into a constraint on the deviation from this relation.
Observational Evidence of Changing Photospheric Vector Magnetic Fields Associated with Solar Flares
of Sciences, 20A Datun Road, Chaoyang District, Beijing, 100012, China 3. Key Laboratory of Solar ActivityObservational Evidence of Changing Photospheric Vector Magnetic Fields Associated with Solar Flares University, Beijing 100875, China sjt@bao.ac.cn Received ; accepted Not to appear in Nonlearned J., 45. #12
He I vector magnetic field maps of a sunspot and its superpenumbral fine-structure
Schad, T A; Lin, H; Tritschler, A
2015-01-01T23:59:59.000Z
Advanced inversions of high-resolution spectropolarimetric observations of the He I triplet at 1083 nm are used to generate unique maps of the chromospheric magnetic field vector across a sunspot and its superpenumbral canopy. The observations were acquired by the Facility Infrared Spectropolarimeter (FIRS) at the Dunn Solar Telescope (DST) on 29 January 2012. Multiple atmospheric models are employed in the inversions, as superpenumbral Stokes profiles are dominated by atomic-level polarization while sunspot profiles are Zeeman-dominated but also exhibit signatures perhaps induced by symmetry breaking effects of the radiation field incident on the chromospheric material. We derive the equilibrium magnetic structure of a sunspot in the chromosphere, and further show that the superpenumbral magnetic field does not appear finely structured, unlike the observed intensity structure. This suggests fibrils are not concentrations of magnetic flux but rather distinguished by individualized thermalization. We also dire...
CMC surfaces in metric Lie groups Joaquin Perez
Perez, Joaquin
invariant X = Xa g = ({left inv vector fields} TeG, [·, ·]) Lie algebra of G. g = ({right inv vector fields} TeG, [·, ·]) = g (Lie algebra isom) If G is simply-connected, then g determines G up
Hinode Observations of Vector Magnetic Field Change Associated with a Flare on 2006 December 13
Masahito Kubo; Takaaki Yokoyama; Yukio Katsukawa; Bruce W Lites; Saku Tsuneta; Yoshinori Suematsu; Kiyoshi Ichimoto; Toshifumi Shimizu; Shin'ichi Nagata; Theodore D Tarbell; Richard A Shine; Alan M Title; David Elmore
2007-09-17T23:59:59.000Z
Continuous observations of a flare productive active region 10930 were successfully carried out with the Solar Optical Telescope onboard the Hinode spacecraft during 2007 December 6 to 19. We focus on the evolution of photospheric magnetic fields in this active region, and magnetic field properties at the site of the X3.4 class flare, using a time series of vector field maps with high spatial resolution. The X3.4 class flare occurred on 2006 December 13 at the apparent collision site between the large, opposite polarity umbrae. Elongated magnetic structures with alternatingly positive and negative polarities resulting from flux emergence appeared one day before the flare in the collision site penumbra. Subsequently, the polarity inversion line at the collision site became very complicated. The number of bright loops in Ca II H increased during the formation of these elongated magnetic structures. The flare ribbons and bright loops evolved along the polarity inversion line and one footpoint of the bright loop was located in a region having a large departure of field azimuth angle with respect to its surroundings. The SOT observations with high spatial resolution and high polarization precision reveal temporal change in fine structure of magnetic fields at the flare site: some parts of the complicated polarity inversion line then disappeared, and in those regions the azimuth angle of photospheric magnetic field changed by about 90 degrees, becoming more spatially uniform within the collision site.
Jacobi-Lie systems: fundamentals and low-dimensional classification
F. J. Herranz; J. de Lucas; C. Sardon
2014-11-30T23:59:59.000Z
A Lie system is a system of differential equations describing the integral curves of a $t$-dependent vector field taking values in a finite-dimensional real Lie algebra of vector fields, a Vessiot-Guldberg Lie algebra. We define and analyze Lie systems possessing a Vessiot-Guldberg Lie algebra of Hamiltonian vector fields relative to a Jacobi manifold, the hereafter called Jacobi-Lie systems. We classify Jacobi-Lie systems on $\\mathbb{R}$ and $\\mathbb{R}^2$. Our results shall be illustrated through examples of physical and mathematical interest.
Fine Entanglement and State Manipulation of Two Spin Coupled Qubits: A Lie Theoretic Overview
Roderick Vance
2015-02-18T23:59:59.000Z
By building on the work in Kuzmak & Tkachuk, "Preparation of quantum states of two spin-$\\frac{1}{2}$ particles in the form of the Schmidt decomposition", Physics Letters A, {\\bf 378}, pp1469-1474, which outlined the control of the degree of entanglement within this system, it is proven that any $SU(4)$ state manipulation operator can be realised for this system using a sequence of pulsed magnetic fields in either two linearly independent directions if the gyromagnetic ratios are unequal or three directions for equal gyromagnetic ratios. To achieve this goal, an elementary Lie theoretic proof of the fact that the group of transformations generated by finite products of exponentials of a set of Lie algebra vectors is equal to the Lie group generated by the smallest Lie algebra containing those vectors is rewritten into an explicit algorithm. A numerical example as well as the proof of the algorithm's effectiveness is given.
Schad, T A
2015-01-01T23:59:59.000Z
We study 7530 sunspot umbrae and pores measured by the Hinode Spectropolarimeter (SP) between November 2006 and November 2012. We primarily seek confirmation of the long term secular decrease in the mean magnetic field strength of sunspot umbrae found by Penn and Livingston (2011, IAU Symp. 273,126) between 1998 and 2011. The excellent SP photometric properties and full vector magnetic field determinations from full-Stokes Milne-Eddington inversions are used to address the interrelated properties of the magnetic field strength and brightness temperature for all umbral cores. We find non-linear relationships between magnetic field strength and umbral temperature (and continuum contrast), as well as between umbral radius and magnetic field strength. Using disambiguated vector data, we find that the azimuths measured in the umbral cores reflect an organization weakly influenced by Joy's law. The large selection of umbrae displays a log-normal size spectrum similar to earlier solar cycles. Influenced by the ampli...
Vector-current correlation and charge separation via the chiral-magnetic effect
Nam, Seung-il [Department of Physics, Chung-Yuan Christian University, Chung-Li 32023, Taiwan (China); Research Institute of Basic Sciences, Korea Aerospace University, Goyang, 412-791 (Korea, Republic of)
2010-08-15T23:59:59.000Z
We investigate the vector-current correlation {Pi}{sub {mu}{nu}}(VCC) in the presence of a strong external magnetic field (B=B{sub 0} in the z direction) at low temperature (T < or approx. T{sub c}{sup {chi}}) with P and CP violations, indicated by the nonzero chiral-chemical potential ({mu}{sub {chi}{ne}0}), i.e. the chiral-magnetic effect (CME). For this purpose, we employ the instanton-vacuum configuration at finite T with nonzero topological charge (Q{sub t{ne}}0). We also consider a simple estimation for the nonzero-mode contributions to the quark propagator, in addition to the zero-mode approximation. From the numerical calculations, it turns out that the longitudinal component of the connected VCC is linear in B{sub 0} and shows a bump, representing a corresponding vector meson at |Q|=(300{approx}400) MeV for T=0. The bump becomes enhanced as T increases and the bump position shifts to a lager |Q| value. In the limit of |Q|{yields}0, the transverse component of the connected VCC disappears, whereas the longitudinal one remains finite and becomes insensitive to B{sub 0} with respect to T, due to diluting instanton contributions. Considering the simple collision geometry of heavy-ion collision and some assumptions on the induced magnetic field and screening effect, we can estimate the charge separation as a function of centrality using the present results for the VCC. The numerical results show a qualitative agreement with experiments for the Au+Au and Cu+Cu collisions. These results are almost independent on the source of the CME, instanton, or sphaleron, as long as the CME current is linear in B{sub 0}.
Lie symmetries for Lie systems: applications to systems of ODEs and PDEs
P. G. Estévez; F. J. Herranz; J. de Lucas; C. Sardón
2014-04-10T23:59:59.000Z
A {\\it Lie system} is a nonautonomous system of first-order differential equations admitting a {\\it superposition rule}, i.e., a map expressing its general solution in terms of a generic family of particular solutions and some constants. Using that a Lie system can be considered as a curve in a finite-dimensional Lie algebra of vector fields, a so-called {\\it Vessiot--Guldberg Lie algebra}, we associate every Lie system with a Lie algebra of Lie point symmetries induced by the Vessiot--Guldberg Lie algebra. This enables us to derive Lie symmetries of relevant physical systems described by first- and higher-order systems of differential equations by means of Lie systems in an easier way than by standard methods. A generalization of our results to partial differential equations is introduced. Among other applications, Lie symmetries for several new and known generalizations of the real Riccati equation are studied.
Solar Flare Prediction Using SDO/HMI Vector Magnetic Field Data with a Machine-Learning Algorithm
Bobra, Monica G
2014-01-01T23:59:59.000Z
We attempt to forecast M-and X-class solar flares using a machine-learning algorithm, called Support Vector Machine (SVM), and four years of data from the Solar Dynamics Observatory's Helioseismic and Magnetic Imager, the first instrument to continuously map the full-disk photospheric vector magnetic field from space. Most flare forecasting efforts described in the literature use either line-of-sight magnetograms or a relatively small number of ground-based vector magnetograms. This is the first time a large dataset of vector magnetograms has been used to forecast solar flares. We build a catalog of flaring and non-flaring active regions sampled from a database of 2,071 active regions, comprised of 1.5 million active region patches of vector magnetic field data, and characterize each active region by 25 parameters. We then train and test the machine-learning algorithm and we estimate its performances using forecast verification metrics with an emphasis on the True Skill Statistic (TSS). We obtain relatively h...
GLOBAL TWIST OF SUNSPOT MAGNETIC FIELDS OBTAINED FROM HIGH-RESOLUTION VECTOR MAGNETOGRAMS
Tiwari, Sanjiv Kumar; Venkatakrishnan, P. [Udaipur Solar Observatory, Physical Research Laboratory, Dewali, Bari Road, Udaipur-313 001 (India); Sankarasubramanian, K. [Space Astronomy and Instrumentation Division, ISRO Satellite Center, Airport Road, Vimanapura, Bangalore-560017 (India)], E-mail: stiwari@prl.res.in, E-mail: pvk@prl.res.in, E-mail: sankark@isac.gov.in
2009-09-10T23:59:59.000Z
The presence of fine structures in sunspot vector magnetic fields has been confirmed from Hinode as well as other earlier observations. We studied 43 sunspots based on the data sets taken from ASP/DLSP, Hinode (SOT/SP), and SVM (USO). In this Letter, (1) we introduce the concept of signed shear angle (SSA) for sunspots and establish its importance for non-force-free fields. (2) We find that the sign of global {alpha} (force-free parameter) is well correlated with that of the global SSA and the photospheric chirality of sunspots. (3) Local {alpha} patches of opposite signs are present in the umbra of each sunspot. The amplitude of the spatial variation of local {alpha} in the umbra is typically of the order of the global {alpha} of the sunspot. (4) We find that the local {alpha} is distributed as alternately positive and negative filaments in the penumbra. The amplitude of azimuthal variation of the local {alpha} in the penumbra is approximately an order of magnitude larger than that in the umbra. The contributions of the local positive and negative currents and {alpha} in the penumbra cancel each other giving almost no contribution for their global values for the whole sunspot. (5) Arc-like structures (partial rings) with a sign opposite to that of the dominant sign of {alpha} of the umbral region are seen at the umbral-penumbral boundaries of some sunspots. (6) Most of the sunspots studied belong to the minimum epoch of the 23rd solar cycle and do not follow the so-called hemispheric helicity rule.
Arbelaez, D.; Black, A.; Prestemon, S.O.; Wang, S.; Chen, J.; Arenholz, E.
2010-01-13T23:59:59.000Z
An eight-pole superconducting magnet is being developed for soft x-ray magnetic dichroism (XMD) experiments at the Advanced Light Source, Lawrence Berkley National Laboratory (LBNL). Eight conical Nb{sub 3}Sn coils with Holmium poles are arranged in octahedral symmetry to form four dipole pairs that provide magnetic fields of up to 5 T in any direction relative to the incoming x-ray beam. The dimensions of the magnet yoke as well as pole taper, diameter, and length were optimized for maximum peak field in the magnet center using the software package TOSCA. The structural analysis of the magnet is performed using ANSYS with the coil properties derived using a numerical homogenization scheme. It is found that the use of orthotropic material properties for the coil has an important influence in the design of the magnet.
Kong, Seong Deok
2010-01-01T23:59:59.000Z
a demonstration of remote heating as a function of applied55 Figure 27. Remote magnetic field heating of fluid (water)Figure 27. Remote magnetic field heating of fluid (water)
Gosain, S; Rudenko, G V; Anfinogentov, S A
2013-01-01T23:59:59.000Z
We use daily full-disk vector magnetograms from Vector Spectromagnetograph (VSM) on Synoptic Optical Long-term Investigations of the Sun (SOLIS) system to synthesize the first Carrington maps of the photospheric vector magnetic field. We describe these maps and make a comparison of observed radial field with the radial field estimate from LOS magnetograms. Further, we employ these maps to study the hemispheric pattern of current helicity density, Hc, during the rising phase of the solar cycle 24. Longitudinal average over the 23 consecutive solar rotations shows a clear signature of the hemispheric helicity rule, i.e. Hc is predominantly negative in the North and positive in South. Although our data include the early phase of cycle 24, there appears no evidence for a possible (systematic) reversal of the hemispheric helicity rule at the beginning of cycle as predicted by some dynamo models. Further, we compute the hemispheric pattern in active region latitudes (-30 deg \\le \\theta \\le 30 deg) separately for we...
Stator-flux-based vector control of induction machines in magnetic saturation
Hofmann, H.; Sanders, S.R.; Sullivan, C. [Univ. of California, Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Sciences
1995-12-31T23:59:59.000Z
In many variable-torque applications of induction machines it is desirable to operate the machine in magnetic saturation, thus allowing the machine to produce higher torques. Stator-flux-based control schemes have been developed as a possible alternative method of control of induction machines. Stator-flux-based control schemes need not depend on the magnetic characteristics of the machine, and hence are potentially more robust and easier to implement in magnetic saturation than rotor-flux-based control. The authors analyze the induction machine in saturation using a nonlinear {pi}-model of the machine`s magnetics, and develop a control scheme in the stator flux reference frame that is independent of magnetics. Experiments carried out on a 3 hp, 1,800 rpm wound rotor induction machine show smooth operation of the control scheme at torque levels up to at least 4 times rated torque.
Gosain, S.; Pevtsov, A. A. [National Solar Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Rudenko, G. V.; Anfinogentov, S. A. [Institute of Solar-Terrestrial Physics (ISTP), Russian Academy of Sciences, Irkutsk (Russian Federation)
2013-07-20T23:59:59.000Z
We use daily full-disk vector magnetograms from Vector Spectromagnetograph on Synoptic Optical Long-term Investigations of the Sun system to synthesize the first Carrington maps of the photospheric vector magnetic field. We describe these maps and make a comparison of the observed radial field with the radial field estimate from line-of-sight magnetograms. Furthermore, we employ these maps to study the hemispheric pattern of current helicity density, H{sub c} , during the rising phase of solar cycle 24. The longitudinal average over the 23 consecutive solar rotations shows a clear signature of the hemispheric helicity rule, i.e., H{sub c} is predominantly negative in the north and positive in the south. Although our data include the early phase of cycle 24, there appears to be no evidence for a possible (systematic) reversal of the hemispheric helicity rule at the beginning of the cycle as predicted by some dynamo models. Furthermore, we compute the hemispheric pattern in active region latitudes (-30 Degree-Sign {<=} {theta} {<=} 30 Degree-Sign ) separately for weak (100 G < |B{sub r} | < 500 G) and strong (|B{sub r} | > 1000 G) radial magnetic fields. We find that while the current helicity of strong fields follows the well-known hemispheric rule (i.e., {theta} {center_dot} H{sub c} < 0), H{sub c} of weak fields exhibits an inverse hemispheric behavior (i.e., {theta} {center_dot} H{sub c} > 0), albeit with large statistical scatter. We discuss two plausible scenarios to explain the opposite hemispheric trend of helicity in weak and strong field regions.
Hayashi, Keiji; Liu, Yang; Bobra, Monica G; Sun, Xudong D; Norton, Aimee A
2015-01-01T23:59:59.000Z
Time-dependent three-dimensional magnetohydrodynamics (MHD) simulation modules are implemented at the Joint Science Operation Center (JSOC) of Solar Dynamics Observatory (SDO). The modules regularly produce three-dimensional data of the time-relaxed minimum-energy state of the solar corona using global solar-surface magnetic-field maps created from Helioseismic Magnetic Imager (HMI) full-disk magnetogram data. With the assumption of polytropic gas with specific heat ratio of 1.05, three types of simulation products are currently generated: i) simulation data with medium spatial resolution using the definitive calibrated synoptic map of the magnetic field with a cadence of one Carrington rotation, ii) data with low spatial resolution using the definitive version of the synchronic frame format of the magnetic field, with a cadence of one day, and iii) low-resolution data using near-real-time (NRT) synchronic format of the magnetic field on daily basis. The MHD data available in the JSOC database are three-dimen...
Magnetic moments of vector, axial, and tensor mesons in lattice QCD
Lee, F X; Wilcox, W
2008-01-01T23:59:59.000Z
We present a calculation of magnetic moments for selected spin-1 mesons using the techniques of lattice QCD. This is carried out by introducing progressively small static magnetic field on the lattice and measuring the linear response of a hadron's mass shift. The calculations are done on $24^4$ quenched lattices using standard Wilson actions, with $\\beta$=6.0 and pion mass down to 500 MeV. The results are compared to those from the form factor method where available.
Energy Levels and Wave Functions of Vector Bosons in Homogeneous Magnetic Field
K. Sogut; A. Havare; I. Acikgoz
2001-10-24T23:59:59.000Z
We aimed to obtain the energy levels of spin-1 particles moving in a constant magnetic field. The method used here is completely algebraic. In the process to obtain the energy levels the wave function is choosen in terms of Laguerre Polynomials.
Controllability of Linear Systems with inner derivation on Lie Groups
Boyer, Edmond
Controllability of Linear Systems with inner derivation on Lie Groups Philippe JOUAN November 2 group of automorphisms. A control-ane system is linear if the drift is linear and the controlled vector groups are stated. The paper ends by many examples. Keywords: Lie groups; Linear systems; controllability
THE ELEMENTARY GEOMETRIC STRUCTURE OF COMPACT LIE GROUPS
Wilkerson, Clarence
map (resp. a homomorphism which is also a diffeomorphism). If G is a Lie group then TeG denotes gives a linear map (d)e : TeG TeH. Occasionally we treat a real vector space V as a (noncompact) Lie
Clean measurements of the nucleon axial-vector and free-neutron magnetic form factors
Alexandre Deur
2014-07-21T23:59:59.000Z
We discuss the feasibility of a weak charged current experiment using a low energy electron beam. A first goal is to measure the Q^2 dependence of the axial-vector form factor g_a(Q^2). It can be measured model-independently and as robustly as for electromagnetic form factors from typical electron scattering experiments, in contrast to the methods used so far to measure g_a(Q^2). If g_a(Q^2) follows a dipole form, the axial mass can be extracted with a better accuracy than the world data altogether. The most important detection equipment would be a segmented neutron detector with good momentum and angular resolution that is symmetric about the beam direction, and covers a moderate angular range. A high intensity beam (100 uA) is necessary. Beam polarization is highly desirable as it provides a clean measurement of the backgrounds. Beam energies between 70 and 110 MeV are ideal. This range would provide a Q^2 mapping of g_a between 0.01
VB-algebroids and representation theory of Lie algebroids
Gracia-Saz, Alfonso
2008-01-01T23:59:59.000Z
A VB-algebroid is essentially defined as a Lie algebroid object in the category of vector bundles. There is a one-to-one correspondence between VB-algebroids and certain flat Lie algebroid superconnections, up to a natural notion of equivalence. In this setting, we are able to construct characteristic classes, which in special cases reproduce characteristic classes constructed by Crainic and Fernandes. We give a complete classification of regular VB-algebroids, and in the process we obtain another characteristic class of Lie algebroids that does not appear in the ordinary representation theory of Lie algebroids.
Lie algebraic noncommutative gravity
Banerjee, Rabin; Samanta, Saurav [S. N. Bose National Centre for Basic Sciences, JD Block, Sector III, Salt Lake, Kolkata-700098 (India); Mukherjee, Pradip [Presidency College, 86/1 College Street, Kolkata-700073, West-Bengal (India)
2007-06-15T23:59:59.000Z
We exploit the Seiberg-Witten map technique to formulate the theory of gravity defined on a Lie algebraic noncommutative space-time. Detailed expressions of the Seiberg-Witten maps for the gauge parameters, gauge potentials, and the field strengths have been worked out. Our results demonstrate that notwithstanding the introduction of more general noncommutative structure there is no first order correction, exactly as happens for a canonical (i.e. constant) noncommutativity.
Optimal control of affine connection control systems from the point of view of Lie algebroids
L. Abrunheiro; M. Camarinha
2014-06-13T23:59:59.000Z
The purpose of this paper is to use the framework of Lie algebroids to study optimal control problems for affine connection control systems on Lie groups. In this context, the equations for critical trajectories of the problem are geometrically characterized as a Hamiltonian vector field.
Parabolic curves in Lie groups
Pauley, Michael [School of Mathematics and Statistics, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009 (Australia)
2010-05-15T23:59:59.000Z
To interpolate a sequence of points in Euclidean space, parabolic splines can be used. These are curves which are piecewise quadratic. To interpolate between points in a (semi-)Riemannian manifold, we could look for curves such that the second covariant derivative of the velocity is zero. We call such curves Jupp and Kent quadratics or JK-quadratics because they are a special case of the cubic curves advocated by Jupp and Kent. When the manifold is a Lie group with bi-invariant metric, we can relate JK-quadratics to null Lie quadratics which arise from another interpolation problem. We solve JK-quadratics in the Lie groups SO(3) and SO(1,2) and in the sphere and hyperbolic plane, by relating them to the differential equation for a quantum harmonic oscillator00.
Guilfoyle, R.A.; Smith, L.M.
1994-12-27T23:59:59.000Z
A vector comprising a filamentous phage sequence containing a first copy of filamentous phage gene X and other sequences necessary for the phage to propagate is disclosed. The vector also contains a second copy of filamentous phage gene X downstream from a promoter capable of promoting transcription in a bacterial host. In a preferred form of the present invention, the filamentous phage is M13 and the vector additionally includes a restriction endonuclease site located in such a manner as to substantially inactivate the second gene X when a DNA sequence is inserted into the restriction site. 2 figures.
Properties of an axially periodic magnetic field in a betatron
Zvontsov, A.A.; Filinova, V.A.; Chakhlov, V.L.
1983-07-01T23:59:59.000Z
It is shown by solving an equation for the vector potential A (r, z) of the magnetic field that under appropriate conditions the focusing properties of a betatron magnetic field are periodic with respect to the z coordinate. Under these conditions there may be several equilibrium orbits lying in parallel planes z = 0, z = z/sub 01/ xxx, z = mz/sub 01/ in the accelerator. An equation is derived for the distance z/sub 01/ between the equilibrium orbit planes for a given orbit radius r/sub 0/ and field decay exponent n/sub 0/. The operation of such accelerators is described.
Reception of longitudinal vector potential radiation with a plasma antenna
Zimmerman, Robert K. Jr. [Sigma Space Corporation, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, Maryland 20771 (United States)] [Sigma Space Corporation, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, Maryland 20771 (United States)
2013-07-28T23:59:59.000Z
To help resolve the long-running debate between physicists and engineers regarding the existence of the magnetic vector potential, herewith we describe an experiment demonstrating reception of time-harmonic vector potential radiation at 1.3 GHz.
Cremmer-Gervais Quantum Lie Algebra
O. Ogievetsky; T. Popov
2009-05-06T23:59:59.000Z
We describe a quantum Lie algebra based on the Cremmer-Gervais R-matrix. The algebra arises upon a restriction of an infinite-dimensional quantum Lie algebra.
On infinite-dimensional 3-Lie algebras
Ding, Lu; Jia, Xiaoyu [Institute of Applied Mathematics, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China)] [Institute of Applied Mathematics, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China); Zhang, Wei, E-mail: wzhangbit@gmail.com [School of Mathematics and Statistics, Beijing Institute of Technology, Beijing 100081 (China)] [School of Mathematics and Statistics, Beijing Institute of Technology, Beijing 100081 (China)
2014-04-15T23:59:59.000Z
In this paper, we study some properties of w{sub ?}?3-Lie algebra and SDiff(T{sup 2}) 3-Lie algebra and prove that they do not have non-trivial central extensions.
On Characters of F_4 Lie Algebra
M. Gungormez; H. R. Karadayi
2008-10-15T23:59:59.000Z
In a previous work, we have given an explicit method to obtain irreducible characters of finite Lie algebras without referring to Weyl character formula. Irreducible characters of $G_2$ Lie algebra has been given as an example. The work is now extended to somewhat more complicated case of $F_4$ Lie algebra, in the same manner.
Magnetic Geodesic Flows on Coadjoint Orbits Alexey V. Bolsinov , Bozidar Jovanovic
). 2 Magnetic Coadjoint Orbits Let G be a compact connected Lie group with the Lie algebra g = TeG. Let
Broader source: Energy.gov [DOE]
Geeks, pay attention! We've got a BioEnergy Atlas, aerosols and climate, sour stuff, and 3D magnetic interactions in this edition of the Geek Up!
Fisher, George H; Bercik, David J; Kazachenko, Maria D; Lynch, Benjamin J; Welsch, Brian T; Hoeksema, J Todd; Hayashi, Keiji; Liu, Yang; Norton, Aimee A; Dalda, Alberto Sainz; Sun, Xudong; DeRosa, Marc L; Cheung, Mark C M
2015-01-01T23:59:59.000Z
The most violent space weather events (eruptive solar flares and coronal mass ejections) are driven by the release of free magnetic energy stored in the solar corona. Energy can build up on timescales of hours to days, and then may be suddenly released in the form of a magnetic eruption, which then propagates through interplanetary space, possibly impacting the Earth's space environment. Can we use the observed evolution of the magnetic and velocity fields in the solar photosphere to model the evolution of the overlying solar coronal field, including the storage and release of magnetic energy in such eruptions? The objective of CGEM, the Coronal Global Evolutionary Model, funded by the NASA/NSF Space Weather Modeling program, is to develop and evaluate such a model for the evolution of the coronal magnetic field. The evolving coronal magnetic field can then be used as a starting point for magnetohydrodynamic (MHD) models of the corona, which can then be used to drive models of heliospheric evolution and predi...
Theory of Lie Groups Claude Chevalley
Landweber, Laura
Theory of Lie Groups Claude Chevalley French mathematician Claude Chevalley had a major influence on the development of several areas of mathematics, but his most important con- tribution is his work on group theory. In Theory of Lie Groups, Chevalley fur- ther developed the ideas that Hermann Weyl pre- sented
Dirac--Lie systems and Schwarzian equations
J. F. Cariñena; J. Grabowski; J. de Lucas; C. Sardón
2014-06-03T23:59:59.000Z
A Lie system is a system of differential equations admitting a superposition rule, i.e., a function describing its general solution in terms of any generic set of particular solutions and some constants. Following ideas going back to the Dirac's description of constrained systems, we introduce and analyse a particular class of Lie systems on Dirac manifolds, called Dirac--Lie systems, which are associated with `Dirac--Lie Hamiltonians'. Our results enable us to investigate constants of the motion, superposition rules, and other general properties of such systems in a more effective way. Several concepts of the theory of Lie systems are adapted to this `Dirac setting' and new applications of Dirac geometry in differential equations are presented. As an application, we analyze traveling wave solutions of Schwarzian equations, but our methods can be applied also to other classes of differential equations important for Physics.
Walker, Thad Gilbert; Lancor, Brian Robert; Wyllie, Robert
2014-04-15T23:59:59.000Z
Precise measurements of a precessional rate of noble gas in a magnetic field is obtained by constraining the time averaged direction of the spins of a stimulating alkali gas to lie in a plane transverse to the magnetic field. In this way, the magnetic field of the alkali gas does not provide a net contribution to the precessional rate of the noble gas.
arXiv:1307.7635v1[math.RA]29Jul2013 HOPF ALGEBRAS IN NON-ASSOCIATIVE LIE THEORY
construction identifies the tangent space TeG with the vector space of left-invariant vector fields on G-invariant, and defines the Lie bracket on TeG. This definition can be stated in different terms. On the tangent bundle on G. This implies that the torsion tensor T is defined completely by its value on TeG, which
Concept of Lie Derivative of Spinor Fields. A Geometric Motivated Approach
Rafael F. Leão; Waldyr A. Rodrigues Jr; Samuel A. Wainer
2015-02-13T23:59:59.000Z
In this paper using the Clifford bundle (Cl(M,g)) and spin-Clifford bundle (Cl_{Spin_{1,3}^{e}}(M,g)) formalism, which permit to give a meaningfull representative of a Dirac-Hestenes spinor field (even section of Cl_{Spin_{1,3}^{e}}(M,g)) in the Clifford bundle , we give a geometrical motivated definition for the Lie derivative of spinor fields in a Lorentzian structure (M,g) where M is a manifold such that dimM =4, g is Lorentzian of signature (1,3). Our Lie derivative, called the spinor Lie derivative (and denoted {\\pounds}_{{\\xi}}) is given by nice formulas when applied to Clifford and spinor fields, and moreoverl {\\pounds}_{{\\xi}}g=0 for any vector field {\\xi}. We compare our definitions and results with the many others appearing in literature on the subject.
Symplectic, orthogonal and linear Lie groups in Clifford algebra
D. S. Shirokov
2014-09-08T23:59:59.000Z
In this paper we prove isomorphisms between 5 Lie groups (of arbitrary dimension and fixed signatures) in Clifford algebra and classical matrix Lie groups - symplectic, orthogonal and linear groups. Also we obtain isomorphisms of corresponding Lie algebras.
Representations up to homotopy of Lie algebroids
Abad, Camilo Arias
2009-01-01T23:59:59.000Z
This is the first in a series of papers devoted to the study of the cohomology of classifying spaces. The aim of this paper is to introduce and study the notion of representation up to homotopy and to make sense of the adjoint representation of a Lie algebroid. Our construction is inspired by Quillen's notion of superconnection and fits into the general theory of structures up to homotopy. The advantage of considering such representations is that they are flexible and general enough to contain interesting examples which are the correct generalization of the corresponding notions for Lie algebras. They also allow one to identify seemingly ad-hoc constructions and cohomology theories as instances of the cohomology with coefficients in representations (up to homotopy). In particular, we show that the adjoint representation of a Lie algebroid makes sense as a representation up to homotopy and that, similar to the case of Lie algebras, the resulting cohomology controls the deformations of the Lie algebroid (i.e. i...
Vector Microprocessors Krste Asanovic
AsanoviÃ¦, Krste
Vector Microprocessors by Krste AsanoviÂ´c B.A. (University of Cambridge) 1987 A dissertation 1998 #12;Vector Microprocessors Copyright 1998 by Krste AsanoviÂ´c #12;1 Abstract Vector Microprocessors microprocessor imple- mentations targeting a much broader range of applications. I present the design
SOLIS Vector Spectromagnetograph: status and science
Henney, C J; Harvey, J W; Georgoulis, M K; Hadder, N L; Norton, A A; Raouafi, N -E; Toussaint, R M
2008-01-01T23:59:59.000Z
The Vector Spectromagnetograph (VSM) instrument has been recording photospheric and chromospheric magnetograms daily since August 2003. Full-disk photospheric vector magnetograms are observed at least weekly and, since November 2006, area-scans of active regions daily. Quick-look vector magnetic images, plus X3D and FITS formated files, are now publicly available daily. In the near future, Milne-Eddington inversion parameter data will also be available and a typical observing day will include three full-disk photospheric vector magnetograms. Besides full-disk observations, the VSM is capable of high temporal cadence area-scans of both the photosphere and chromosphere. Carrington rotation and daily synoptic maps are also available from the photospheric magnetograms and coronal hole estimate images.
SOLIS Vector Spectromagnetograph: status and science
C. J. Henney; C. U. Keller; J. W. Harvey; M. K. Georgoulis; N. L. Hadder; A. A. Norton; N. -E. Raouafi; R. M. Toussaint
2007-12-28T23:59:59.000Z
The Vector Spectromagnetograph (VSM) instrument has been recording photospheric and chromospheric magnetograms daily since August 2003. Full-disk photospheric vector magnetograms are observed at least weekly and, since November 2006, area-scans of active regions daily. Quick-look vector magnetic images, plus X3D and FITS formated files, are now publicly available daily. In the near future, Milne-Eddington inversion parameter data will also be available and a typical observing day will include three full-disk photospheric vector magnetograms. Besides full-disk observations, the VSM is capable of high temporal cadence area-scans of both the photosphere and chromosphere. Carrington rotation and daily synoptic maps are also available from the photospheric magnetograms and coronal hole estimate images.
The Rahman polynomials and the Lie algebra sl_3(C)
Iliev, Plamen
2010-01-01T23:59:59.000Z
We interpret the Rahman polynomials in terms of the Lie algebra $sl_3(C)$. Using the parameters of the polynomials we define two Cartan subalgebras for $sl_3(C)$, denoted $H$ and $\\tilde{H}$. We display an antiautomorphism $\\dagger$ of $sl_3(C)$ that fixes each element of $H$ and each element of $\\tilde{H}$. We consider a certain finite-dimensional irreducible $sl_3(C)$-module $V$ consisting of homogeneous polynomials in three variables. We display a nondegenerate symmetric bilinear form $$ on $V$ such that $ = $ for all $\\beta \\in sl_3(C)$ and $\\xi,\\zeta \\in V$. We display two bases for $V$; one diagonalizes $H$ and the other diagonalizes $\\tilde{H}$. Both bases are orthogonal with respect to $$. We show that when $$ is applied to a vector in each basis, the result is a trivial factor times a Rahman polynomial evaluated at an appropriate argument. Thus for both transition matrices between the bases each entry is described by a Rahman polynomial. From these results we recover the previously known orthogonalit...
Cohen, Arjeh M.
Technische Universiteit Eindhoven P.O. Box 513, 5600 MB Eindhoven, the Netherlands a.m.cohen@tue.nl JAN DRAISMA Department of Mathematics and Computing Science Technische Universiteit Eindhoven P.O. Box 513, 5600 MB Eindhoven, the Netherlands j.draisma@tue.nl Abstract. The action of an affine algebraic group G
Convergence of Galerkin Variational Integrators for Vector Spaces and Lie Groups
Hall, James Brian
attraction. Kepler’s law of gravitation states that theSystem under these laws of gravitation is an open question.
Quantization of extended SchrÄodinger-Virasoro Lie algebra
Lamei Yuan; Liji Zhou
2010-04-21T23:59:59.000Z
In present paper, we quantize the extended Schr\\"Aodinger-Virasoro Lie algebra in char- acteristic zero with its Lie bialgebra structures classified by Yuan-Wu-Xu, and get a new Hopf algebra.
Vector generator scan converter
Moore, James M. (Livermore, CA); Leighton, James F. (Livermore, CA)
1990-01-01T23:59:59.000Z
High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O (input/output) channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardward for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold.
Vector generator scan converter
Moore, J.M.; Leighton, J.F.
1988-02-05T23:59:59.000Z
High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardware for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold. 7 figs.
Lie-Algebroid Formulation of k-Cosymplectic Field Theories
Roman-Roy, Narciso [Departamento de Matematica Aplicada IV. Edificio C-3, Campus Norte UPC. C/Jordi Girona 1. 08034 Barcelona (Spain); Salgado, Modesto; Vilarino, Silvia [Departamento de Xeometria e Topoloxia. Facultade de Matematicas, Universidade de Santiago de Compostela. 15782 Santiago de Compostela (Spain)
2009-05-06T23:59:59.000Z
We present a description for the k-cosymplectic formalism of Hamiltonian field theories in terms of Lie algebroids.
Homotopy commutative algebra and 2-nilpotent Lie algebra
Paris-Sud XI, Université de
Homotopy commutative algebra and 2-nilpotent Lie algebra Michel Dubois-Violette and Todor Popov commutative algebra, or C-algebra, on the cohomology of the free 2-nilpotent Lie algebra. The latter C-algebra Universal Enveloping Algebra (UEA) Ug of a finite dimensional positively graded Lie algebra g belongs
33rd International Lie`ge Colloquium on Ocean Dynamics Lie`ge, Belgium, May 711, 2001
Leonard, John J.
Preface 33rd International Lie`ge Colloquium on Ocean Dynamics Lie`ge, Belgium, May 7Â11, 2001 The International Lie`ge Colloquium on Ocean Dynamics is organized annually. The topic differs from year to year. Assembling a group of active and eminent scien- tists from various countries and often different disci
Dark matter monopoles, vectors and photons
Valentin V. Khoze; Gunnar Ro
2014-06-10T23:59:59.000Z
In a secluded dark sector which is coupled to the Standard Model via a Higgs portal interaction we arrange for the existence of 't Hooft-Polyakov magnetic monopoles and study their implications for cosmology. We point out that a dark sector which can accommodate stable monopoles will also contain massless dark photons gamma' as well as charged massive vector bosons W'. The dark matter in this scenario will be a combination of magnetically and electrically charged species under the unbroken U(1) subgroup of the dark sector. We estimate the cosmological production rate of monopoles and the rate of monopole-anti-monopole annihilation and conclude that monopoles with masses of few hundred TeV or greater, can produce sizeable contributions to the observed dark matter relic density. We scan over the parameter space and compute the relic density for monopoles and vector bosons. Turning to the dark photon radiation, we compute their contribution to the measured density of relativistic particles Neff and also apply observational constraints from the Bullet cluster and other large scale galaxies on long-range interactions for the self-interacting dark matter components made out of monopoles and out of dark vector bosons. At scales relevant for dwarf galaxies we identify regions on the parameter space where self-interacting monopole and vector dark mater components can aid solving the core-cusp and the too-big-to-fail problems.
Alexander Milov
2008-12-21T23:59:59.000Z
This article reviews the current status of experimental results obtained in the measurement of light vector mesons produced in proton-proton and heavy ion collisions at different energies. The review is focused on two phenomena related to the light vector mesons; the modification of the spectral shape in search of Chiral symmetry restoration and suppression of the meson production in heavy ion collisions. The experimental results show that the spectral shape of light vector mesons are modified compared to the parameters measured in vacuum. The nature and the magnitude of the modification depends on the energy density of the media in which they are produced. The suppression patterns of light vector mesons are different from the measurements of other mesons and baryons. The mechanisms responsible for the suppression of the mesons are not yet understood. Systematic comparison of existing experimental results points to the missing data which may help to resolve the problem.
Carrigan, Charles R. (Tracy, CA)
2011-08-02T23:59:59.000Z
A determination is made of frequency components associated with a particular bearing or location resulting from sources emitting electromagnetic-wave energy for which a Poynting-Vector can be defined. The broadband frequency components associated with a specific direction or location of interest are isolated from other components in the power spectrum that are not associated with the direction or location of interest. The collection of pointing vectors can be used to characterize the source.
M. K. Georgoulis; Barry J. LaBonte
2007-06-27T23:59:59.000Z
We self-consistently derive the magnetic energy and relative magnetic helicity budgets of a three-dimensional linear force-free magnetic structure rooted in a lower boundary plane. For the potential magnetic energy we derive a general expression that gives results practically equivalent to those of the magnetic Virial theorem. All magnetic energy and helicity budgets are formulated in terms of surface integrals applied to the lower boundary, thus avoiding computationally intensive three-dimensional magnetic field extrapolations. We analytically and numerically connect our derivations with classical expressions for the magnetic energy and helicity, thus presenting a so-far lacking unified treatment of the energy/helicity budgets in the constant-alpha approximation. Applying our derivations to photospheric vector magnetograms of an eruptive and a noneruptive solar active regions, we find that the most profound quantitative difference between these regions lies in the estimated free magnetic energy and relative magnetic helicity budgets. If this result is verified with a large number of active regions, it will advance our understanding of solar eruptive phenomena. We also find that the constant-alpha approximation gives rise to large uncertainties in the calculation of the free magnetic energy and the relative magnetic helicity. Therefore, care must be exercised when this approximation is applied to photospheric magnetic field observations. Despite its shortcomings, the constant-alpha approximation is adopted here because this study will form the basis of a comprehensive nonlinear force-free description of the energetics and helicity in the active-region solar corona, which is our ultimate objective.
High performance magnetic bearing systems using high temperature superconductors
Abboud, Robert G. (Barrington Hills, IL)
1998-01-01T23:59:59.000Z
A magnetic bearing apparatus and a method for providing at least one stabilizing force in a magnetic bearing structure with a superconducting magnetic assembly and a magnetic assembly, by providing a superconducting magnetic member in the superconducting magnetic assembly with a plurality of domains and arranging said superconducting magnetic member such that at least one domain has a domain C-axis vector alignment angularly disposed relative to a reference axis of the magnetic member in the magnetic assembly.
High performance magnetic bearing systems using high temperature superconductors
Abboud, R.G.
1998-05-05T23:59:59.000Z
Disclosed are a magnetic bearing apparatus and a method for providing at least one stabilizing force in a magnetic bearing structure with a superconducting magnetic assembly and a magnetic assembly, by providing a superconducting magnetic member in the superconducting magnetic assembly with a plurality of domains and arranging said superconducting magnetic member such that at least one domain has a domain C-axis vector alignment angularly disposed relative to a reference axis of the magnetic member in the magnetic assembly. 7 figs.
Polytope expansion of Lie characters and applications
Walton, Mark A., E-mail: walton@uleth.ca [Department of Physics and Astronomy, University of Lethbridge, Lethbridge, Alberta T1K 3M4 (Canada)
2013-12-15T23:59:59.000Z
The weight systems of finite-dimensional representations of complex, simple Lie algebras exhibit patterns beyond Weyl-group symmetry. These patterns occur because weight systems can be decomposed into lattice polytopes in a natural way. Since lattice polytopes are relatively simple, this decomposition is useful, in addition to being more economical than the decomposition into single weights. An expansion of characters into polytope sums follows from the polytope decomposition of weight systems. We study this polytope expansion here. A new, general formula is given for the polytope sums involved. The combinatorics of the polytope expansion are analyzed; we point out that they are reduced from those of the Weyl character formula (described by the Kostant partition function) in an optimal way. We also show that the weight multiplicities can be found easily from the polytope multiplicities, indicating explicitly the equivalence of the two descriptions. Finally, we demonstrate the utility of the polytope expansion by showing how polytope multiplicities can be used in the calculation of tensor product decompositions, and subalgebra branching rules.
Higher jet prolongation Lie algebras and Backlund transformations for (1+1)-dimensional PDEs
Sergey Igonin
2013-05-30T23:59:59.000Z
For any (1+1)-dimensional (multicomponent) evolution PDE, we define a sequence of Lie algebras $F^p$, $p=0,1,2,3,...$, which are responsible for all Lax pairs and zero-curvature representations (ZCRs) of this PDE. In our construction, jets of arbitrary order are allowed. In the case of lower order jets, the algebras $F^p$ generalize Wahlquist-Estabrook prolongation algebras. To achieve this, we find a normal form for (nonlinear) ZCRs with respect to the action of the group of gauge transformations. One shows that any ZCR is locally gauge equivalent to the ZCR arising from a vector field representation of the algebra $F^p$, where $p$ is the order of jets involved in the $x$-part of the ZCR. More precisely, we define a Lie algebra $F^p$ for each nonnegative integer $p$ and each point $a$ of the infinite prolongation $E$ of the evolution PDE. So the full notation for the algebra is $F^p(E,a)$. Using these algebras, one obtains a necessary condition for two given evolution PDEs to be connected by a Backlund transformation. In this paper, the algebras $F^p(E,a)$ are computed for some PDEs of KdV type. In a different paper with G. Manno, we compute $F^p(E,a)$ for multicomponent Landau-Lifshitz systems of Golubchik and Sokolov. Among the obtained Lie algebras, one encounters infinite-dimensional algebras of certain matrix-valued functions on some algebraic curves. Besides, some solvable ideals and semisimple Lie algebras appear in the description of $F^p(E,a)$. Applications to classification of KdV and Krichever-Novikov type equations with respect to Backlund transformations are also briefly discussed.
THE ELEMENTARY GEOMETRIC STRUCTURE OF COMPACT LIE GROUPS
a diffeomorphism). If G is a Lie group then TeG denotes the tangent space to G at the identity element e. If : G H is homomorphism of Lie groups, the differential d gives a linear map (d)e : TeG TeH. Occasionally
A Fractional Lie Group Method For Anomalous Diffusion Equations
Guo-cheng Wu
2010-09-21T23:59:59.000Z
Lie group method provides an efficient tool to solve a differential equation. This paper suggests a fractional partner for fractional partial differential equations using a fractional characteristic method. A space-time fractional diffusion equation is used as an example to illustrate the effectiveness of the Lie group method.
ccsd-00001485,version1-26Apr2004 On the Lie envelopping algebra of a pre-Lie algebra
Boyer, Edmond
ccsd-00001485,version1-26Apr2004 On the Lie envelopping algebra of a pre-Lie algebra J.-M. Oudom combinatorics Hopf algebras were introduced in different settings. One can quote the Hopf algebras of C. Brouder that a lot of these Hopf algebras are related to general algebraic constructions. In the commutative (or
Synchrotron radiation of vector bosons at relativistic colliders
Kirill Tuchin
2014-07-09T23:59:59.000Z
Magnetic fields produced in collisions of electrically charged particles at relativistic energies are strong enough to affect the dynamics of the strong interactions. In particular, it induces radiation of vector bosons by relativistic fermions. To develop deeper insight into this problem, I calculate the corresponding spectrum in constant magnetic field and analyze its angular distribution and mass dependence. As an application, I consider synchrotron radiation of virtual photon by the quark-gluon plasma.
Krawtchouk polynomials, the Lie algebra $\\mathfrak{sl}_2$, and Leonard pairs
Nomura, Kazumasa
2012-01-01T23:59:59.000Z
A Leonard pair is a pair of diagonalizable linear transformations of a finite-dimensional vector space, each of which acts in an irreducible tridiagonal fashion on an eigenbasis for the other one. In the present paper we give an elementary but comprehensive account of how the following are related: (i) Krawtchouk polynomials; (ii) finite-dimensional irreducible modules for the Lie algebra ${\\mathfrak{sl}_2}$; (iii) a class of Leonard pairs said to have Krawtchouk type. Along the way we obtain elementary proofs of some well-known facts about Krawtchouk polynomials, such as the three-term recurrence, the orthogonality, the difference equation, and the generating function. The paper is a tutorial meant for a graduate student or a researcher unfamiliar with the above topics.
Internet Supplement for Vector Calculus
Jerry Marsden
2003-10-07T23:59:59.000Z
Apr 3, 2010 ... Page i. Internet Supplement for Vector Calculus. Fifth Edition. Version: October, 2003. Jerrold E. Marsden. California Institute of Technology.
Quantized Nambu-Poisson manifolds and n-Lie algebras
DeBellis, Joshua; Saemann, Christian; Szabo, Richard J. [Department of Mathematics, Heriot-Watt University, Colin Maclaurin Building, Riccarton, Edinburgh EH14 4AS (United Kingdom) and Maxwell Institute for Mathematical Sciences, Edinburgh (United Kingdom)
2010-12-15T23:59:59.000Z
We investigate the geometric interpretation of quantized Nambu-Poisson structures in terms of noncommutative geometries. We describe an extension of the usual axioms of quantization in which classical Nambu-Poisson structures are translated to n-Lie algebras at quantum level. We demonstrate that this generalized procedure matches an extension of Berezin-Toeplitz quantization yielding quantized spheres, hyperboloids, and superspheres. The extended Berezin quantization of spheres is closely related to a deformation quantization of n-Lie algebras as well as the approach based on harmonic analysis. We find an interpretation of Nambu-Heisenberg n-Lie algebras in terms of foliations of R{sup n} by fuzzy spheres, fuzzy hyperboloids, and noncommutative hyperplanes. Some applications to the quantum geometry of branes in M-theory are also briefly discussed.
Thomas Hambye
2010-03-16T23:59:59.000Z
We show that dark matter could be made of massive gauge bosons whose stability doesn't require to impose by hand any discrete or global symmetry. Stability of gauge bosons can be guaranteed by the custodial symmetry associated to the gauge symmetry and particle content of the model. The particle content we consider to this end is based on a hidden sector made of a vector multiplet associated to a non-abelian gauge group and of a scalar multiplet charged under this gauge group. The hidden sector interacts with the Standard Model particles through the Higgs portal quartic scalar interaction in such a way that the gauge bosons behave as thermal WIMPS. This can lead easily to the observed dark matter relic density in agreement with the other various constraints, and can be tested experimentally in a large fraction of the parameter space. In this model the dark matter direct detection rate and the annihilation cross section can decouple if the Higgs portal interaction is weak.
Exceptional Lie Groups, E-infinity Theory and Higgs Boson
Ayman A. El-Okaby
2007-12-30T23:59:59.000Z
In this paper, we study the correlation between the exceptional lie groups and El-Naschie's transfinite E-infinity spacetime theory. Subsequently this is used to calculate the number of elementary particles in the standard model, mass of the Higgs boson and some coupling constants.
An introduction to Lie group integrators – basics, new developments and applications
Celledoni, Elena, E-mail: elenac@math.ntnu.no [Department of Mathematical Sciences, NTNU, N-7491 Trondheim (Norway)] [Department of Mathematical Sciences, NTNU, N-7491 Trondheim (Norway); Marthinsen, Håkon, E-mail: hakonm@math.ntnu.no [Department of Mathematical Sciences, NTNU, N-7491 Trondheim (Norway)] [Department of Mathematical Sciences, NTNU, N-7491 Trondheim (Norway); Owren, Brynjulf, E-mail: bryn@math.ntnu.no [Department of Mathematical Sciences, NTNU, N-7491 Trondheim (Norway)] [Department of Mathematical Sciences, NTNU, N-7491 Trondheim (Norway)
2014-01-15T23:59:59.000Z
We give a short and elementary introduction to Lie group methods. A selection of applications of Lie group integrators are discussed. Finally, a family of symplectic integrators on cotangent bundles of Lie groups is presented and the notion of discrete gradient methods is generalised to Lie groups.
247VECTORIZING THE COMMUNITY LAND MODEL VECTORIZING THE COMMUNITY
Hoffman, Forrest M.
systems models (including the CLM) on vector architectures. However, the prior development of the CLM in Japan and the Cray X1 at Oak Ridge National Laboratory (ORNL) spawned renewed interest in running Earth
Electric-magnetic duality implies (global) conformal invariance
Sung-Pil Moon; Sang-Jin Lee; Ji-Hye Lee; Jae-Hyuk Oh
2014-05-30T23:59:59.000Z
We have examined quantum theories of electric magnetic duality invariant vector fields enjoying classical conformal invariance in 4-dimensional flat spacetime. We extend Dirac's argument about "the conditions for a quantum field theory to be relativistic" to "those for a quantum theory to be conformal". We realize that electric magnetic duality invariant vector theories together with classical conformal invariance defined in 4-$d$ flat spacetime are still conformally invariant theories when they are quantized in a way that electric magnetic duality is manifest.
Lie-transform theory of transport in plasma turbulence
Wang, Shaojie, E-mail: wangsj@ustc.edu.cn [Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)
2014-07-15T23:59:59.000Z
From the Vlasov equation, a phase-space transport equation is derived by using the Lie-transform approach, and its connection with the quasilinear transport, nonlinear stochastic transport, and fractional transport equations are discussed. The phase-space transport equation indicates a particle redistribution in the real space induced by the inhomogeneity in the energy space distribution and by the correlation between the change of position and the change of energy.
Matrix adaptation in discriminative vector quantization
Zachmann, Gabriel
. Gabriel Zachmann (Computer Graphics) #12;Matrix adaptation in discriminative vector quantization Petra
Matrix Learning in Learning Vector Quantization
Biehl, Michael
Zachmann (Computer Graphics) #12;Matrix Learning in Learning Vector Quantization Michael Biehl1 , Barbara
Temnov, Vasily V.
The magnetic field is an interesting candidate for the development of active plasmonic devices as it is able to modify the surface plasmon polariton (SPP) wave vector. Both real and imaginary parts of the SPP wave vector ...
Hom Gel'fand-Dorfman bialgebras and Hom-Lie conformal algebras
Yuan, Lamei, E-mail: lmyuan@hit.edu.cn [Science Research Center, Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150080 (China)] [Science Research Center, Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150080 (China)
2014-04-15T23:59:59.000Z
The aim of this paper is to introduce the notions of Hom Gel'fand-Dorfman bialgebra and Hom-Lie conformal algebra. In this paper, we give four constructions of Hom Gel'fand-Dorfman bialgebras. Also, we provide a general construction of Hom-Lie conformal algebras from Hom-Lie algebras. Finally, we prove that a Hom Gel'fand-Dorfman bialgebra is equivalent to a Hom-Lie conformal algebra of degree 2.
Simultaneous description of low-lying positive and negative parity bands in heavy even-even nuclei
H. G. Ganev
2014-09-05T23:59:59.000Z
The low-lying spectra including the first few excited positive and negative parity bands of some heavy even-even nuclei from the rare earth and actinide mass regions are investigated within the framework of the symplectic Interacting Vector Boson Model with Sp(12,$R$) dynamical symmetry group. Symplectic dynamical symmetries allow the change of the number of excitation quanta or phonons building the collective states providing for larger representation spaces and richer subalgebraic structures to incorporate more complex nuclear spectra. The theoretical predictions for the energy levels and the electromagnetic transitions between the collective states of the ground state band and $K^{\\pi}=0^{-}$ band are compared with experiment and some other collective models incorporating octupole and/or dipole degrees of freedom. The energy staggering which is a sensitive indicator of the octupole correlations in the even-even nuclei is also calculated and compared with experiment. The results obtained for the energy levels, energy staggering and transition strengths reveal the relevance of the used dynamical symmetry of the model for the simultaneous description of both positive and negative parity low-lying collective bands.
Distribution Amplitudes of Vector Mesons
V. M. Braun; D. Brömmel; M. Göckeler; R. Horsley; Y. Nakamura; H. Perlt; D. Pleiter; P. E. L. Rakow; A. Schäfer; G. Schierholz; A. Schiller; W. Schroers; T. Streuer; H. Stüben; J. M. Zanotti
2007-11-14T23:59:59.000Z
Results are presented for the lowest moment of the distribution amplitude for the K-star vector meson. Both longitudinal and transverse moments are investigated. We use two flavours of O(a) improved Wilson fermions, together with a non-perturbative renormalisation of the matrix element.
Lie group classifications and exact solutions for time-fractional Burgers equation
Guo-cheng Wu
2010-11-16T23:59:59.000Z
Lie group method provides an efficient tool to solve nonlinear partial differential equations. This paper suggests a fractional Lie group method for fractional partial differential equations. A time-fractional Burgers equation is used as an example to illustrate the effectiveness of the Lie group method and some classes of exact solutions are obtained.
The Hopf algebra of Fliess operators and its dual pre-Lie Loc Foissy
Paris-Sud XI, Université de
The Hopf algebra of Fliess operators and its dual pre-Lie algebra Loïc Foissy Laboratoire de.foissy@univ-reims.fr ABSTRACT. We study the Hopf algebra H of Fliess operators coming from Control Theory in the one space R x0, x1 is both a pre-Lie algebra for the pre-Lie product dual of the coproduct of H
Vector-thread architecture and implementation
Krashinsky, Ronny (Ronny Meir), 1978-
2007-01-01T23:59:59.000Z
This thesis proposes vector-thread architectures as a performance-efficient solution for all-purpose computing. The VT architectural paradigm unifies the vector and multithreaded compute models. VT provides the programmer ...
Dirac quantization of the vector superfield
Barcelos-Neto, J.; Braga, N.R.F.
1989-01-15T23:59:59.000Z
We use the Dirac quantization method in superspace to quantize the Abelian vector superfield in the Wess-Zumino gauge.
Optimization Online - Vector Space Decomposition for Linear ...
Jean Bertrand Gauthier
2015-02-26T23:59:59.000Z
Feb 26, 2015 ... Abstract: This paper describes a vector space decomposition algorithmic framework for linear programming guided by dual feasibility ...
Bret, A., E-mail: antoineclaude.bret@uclm.es [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain and Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain)
2014-02-15T23:59:59.000Z
The filamentation (Weibel) instability plays a key role in the formation of collisionless shocks which are thought to produce Gamma-Ray-Bursts and High-Energy-Cosmic-Rays in astrophysical environments. While it has been known for long that a flow-aligned magnetic field can completely quench the instability, it was recently proved in 2D that in the cold regime, such cancelation is possible if and only if the field is perfectly aligned. Here, this result is finally extended to a 3D geometry. Calculations are conducted for symmetric and asymmetric counter-streaming relativistic plasma shells. 2D results are retrieved in 3D: the instability can never be completely canceled for an oblique magnetic field. In addition, the maximum growth-rate is always larger for wave vectors lying in the plan defined by the flow and the oblique field. On the one hand, this bears consequences on the orientation of the generated filaments. On the other hand, it certifies 2D simulations of the problem can be performed without missing the most unstable filamentation modes.
Classification of prostate magnetic resonance spectra using support vector machine
Paris-Sud XI, Université de
Professeur Marion, 21000 Dijon, France d Oncodesign SA, 20 rue Jean Mazen B.P. 27627, 21076 Dijon, France
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening aTurbulenceUtilize Available Resources PrintValVapor
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening aTurbulenceUtilize Available Resources PrintValVaporRunning jobs
Gauge Theories on de Sitter space and Killing Vectors
Rabin Banerjee
2006-08-14T23:59:59.000Z
We provide a general method for studying a manifestly covariant formulation of $p$-form gauge theories on the de Sitter space. This is done by stereographically projecting the corresponding theories, defined on flat Minkowski space, onto the surface of a de Sitter hyperboloid. The gauge fields in the two descriptions are mapped by conformal Killing vectors allowing for a very transparent analysis and compact presentation of results. As applications, the axial anomaly is computed and the electric-magnetic duality is exhibited. Finally, the zero curvature limit is shown to yield consistent results.
Space Vector PWM Control Synthesis for a H-Bridge Drive in Electric Vehicles
Paris-Sud XI, Université de
Space Vector PWM Control Synthesis for a H-Bridge Drive in Electric Vehicles A. Kolli1 , Student Magnet Synchronous Machine in Electric Vehicle application. First, a short survey of existing power regarding compactness and vehicle integration. More specifically electric vehicles (EVs) require a high
Thermomagnetic burn control for magnetic fusion reactor
Rawls, J.M.; Peuron, A.U.
1980-07-01T23:59:59.000Z
Apparatus is provided for controlling the plasma energy production rate of a magnetic-confinement fusion reactor, by controlling the magnetic field ripple. The apparatus includes a group of shield sectors formed of ferromagnetic material which has a temperature-dependent saturation magnetization, with each shield lying between the plasma and a toroidal field coil. A mechanism for controlling the temperature of the magnetic shields, as by controlling the flow of cooling water therethrough, thereby controls the saturation magnetization of the shields and therefore the amount of ripple in the magnetic field that confines the plasma, to thereby control the amount of heat loss from the plasma. This heat loss in turn determines the plasma state and thus the rate of energy production.
Thermomagnetic burn control for magnetic fusion reactor
Rawls, John M. (Del Mar, CA); Peuron, Unto A. (Solana Beach, CA)
1982-01-01T23:59:59.000Z
Apparatus is provided for controlling the plasma energy production rate of a magnetic-confinement fusion reactor, by controlling the magnetic field ripple. The apparatus includes a group of shield sectors (30a, 30b, etc.) formed of ferromagnetic material which has a temperature-dependent saturation magnetization, with each shield lying between the plasma (12) and a toroidal field coil (18). A mechanism (60) for controlling the temperature of the magnetic shields, as by controlling the flow of cooling water therethrough, thereby controls the saturation magnetization of the shields and therefore the amount of ripple in the magnetic field that confines the plasma, to thereby control the amount of heat loss from the plasma. This heat loss in turn determines the plasma state and thus the rate of energy production.
A Vector-Like Fourth Generation with A Discrete Symmetry From Split-UED
Kong, Kyoungchul; /SLAC; Park, Seong Chan; /Tokyo U., IPMU; Rizzo, Thomas G.; /SLAC
2011-08-19T23:59:59.000Z
Split-UED allows for the possibility that the lowest lying KK excitations of the Standard Model fermions can be much lighter than the corresponding gauge or Higgs KK states. This can happen provided the fermion bulk masses are chosen to be large, in units of the inverse compactification radius, 1/R, and negative. In this setup, all of the other KK states would be effectively decoupled from low energy physics. Such a scenario would then lead to an apparent vector-like fourth generation with an associated discrete symmetry that allows us to accommodate a dark matter candidate. In this paper the rather unique phenomenology presented by this picture will be examined.
Solving Linearized Equations of the $N$-body Problem Using the Lie-integration Method
Andras Pal; Aron Suli
2007-07-23T23:59:59.000Z
Several integration schemes exits to solve the equations of motion of the $N$-body problem. The Lie-integration method is based on the idea to solve ordinary differential equations with Lie-series. In the 1980s this method was applied for the $N$-body problem by giving the recurrence formula for the calculation of the Lie-terms. The aim of this works is to present the recurrence formulae for the linearized equations of motion of $N$-body systems. We prove a lemma which greatly simplifies the derivation of the recurrence formulae for the linearized equations if the recurrence formulae for the equations of motions are known. The Lie-integrator is compared with other well-known methods. The optimal step size and order of the Lie-integrator are calculated. It is shown that a fine-tuned Lie-integrator can be 30%-40% faster than other integration methods.
Formation of magnetic discontinuities through viscous relaxation
Kumar, Sanjay; Bhattacharyya, R. [Udaipur Solar Observatory, Physical Research Laboratory, Dewali, Bari Road, Udaipur-313001 (India); Smolarkiewicz, P. K. [European Centre for Medium-Range Weather Forecasts, Reading RG2 9AX (United Kingdom)
2014-05-15T23:59:59.000Z
According to Parker's magnetostatic theorem, tangential discontinuities in magnetic field, or current sheets (CSs), are generally unavoidable in an equilibrium magnetofluid with infinite electrical conductivity and complex magnetic topology. These CSs are due to a failure of a magnetic field in achieving force-balance everywhere and preserving its topology while remaining in a spatially continuous state. A recent work [Kumar, Bhattacharyya, and Smolarkiewicz, Phys. Plasmas 20, 112903 (2013)] demonstrated this CS formation utilizing numerical simulations in terms of the vector magnetic field. The magnetohydrodynamic simulations presented here complement the above work by demonstrating CS formation by employing a novel approach of describing the magnetofluid evolution in terms of magnetic flux surfaces instead of the vector magnetic field. The magnetic flux surfaces being the possible sites on which CSs develop, this approach provides a direct visualization of the CS formation, helpful in understanding the governing dynamics. The simulations confirm development of tangential discontinuities through a favorable contortion of magnetic flux surfaces, as the magnetofluid undergoes a topology-preserving viscous relaxation from an initial non-equilibrium state with twisted magnetic field. A crucial finding of this work is in its demonstration of CS formation at spatial locations away from the magnetic nulls.
Kinematics in Vector Boson Fusion
D. Green
2006-03-02T23:59:59.000Z
The vector boson fusion process leads to two forward/backward jets (tag jets) and the produced state, a Higgs boson in this case, moving slowly in the p-p C.M. frame at the LHC. For the case of Higgs decaying to W+W (W*) with Higgs mass below 180 GeV, the W bosons have low momentum in the Higgs C.M. For the case of W leptonic decays, this fact allows for an approximate reconstruction of the two final state neutrinos. In turn, those solutions then provide additional kinematic cuts against background.
Vector field theories in cosmology
A. Tartaglia; N. Radicella
2007-08-05T23:59:59.000Z
Recently proposed theories based on the cosmic presence of a vectorial field are compared and contrasted. In particular the so called Einstein aether theory is discussed in parallel with a recent proposal of a strained space-time theory (Cosmic Defect theory). We show that the latter fits reasonably well the cosmic observed data with only one, or at most two, adjustable parameters, whilst other vector theories use much more. The Newtonian limits are also compared. Finally we show that the CD theory may be considered as a special case of the aether theories, corresponding to a more compact and consistent paradigm.
The Higgs mass derived from the U(3) Lie group
Trinhammer, Ole L; Jensen, Mogens Stibius
2015-01-01T23:59:59.000Z
The Higgs mass value is derived from a Hamiltonian on the Lie group U(3) where we relate strong and electroweak energy scales. The baryon states of nucleon and delta resonances originate in specific Bloch wave degrees of freedom coupled to a Higgs mechanism which also gives rise to the usual gauge boson masses. The derived Higgs mass is around 125 GeV. From the same Hamiltonian we derive the relative neutron to proton mass ratio. All compare rather well with the experimental values. We predict scarce neutral flavour baryon singlets that should be visible in scattering cross sections for negative pions on protons, in photoproduction on neutrons, in neutron diffraction dissociation experiments and in invariant mass spectra of protons and negative pions in B-decays. The fundamental predictions are based on just one length scale and the fine structure constant. More particular predictions rely also on the weak mixing angle and the up-down quark flavour mixing matrix element. With differential forms on the measure...
The Higgs mass derived from the U(3) Lie group
Ole L. Trinhammer; Henrik G. Bohr; Mogens Stibius Jensen
2014-12-07T23:59:59.000Z
The Higgs mass value is derived from a Hamiltonian on the Lie group U(3) where we relate strong and electroweak energy scales. The baryon states of nucleon and delta resonances originate in specific Bloch wave degrees of freedom coupled to a Higgs mechanism which also gives rise to the usual gauge boson masses. The derived Higgs mass is around 125 GeV. From the same Hamiltonian we derive the relative neutron to proton mass ratio. All compare rather well with the experimental values. We predict scarce neutral flavour baryon singlets that should be visible in scattering cross sections for negative pions on protons, in photoproduction on neutrons, in neutron diffraction dissociation experiments and in invariant mass spectra of protons and negative pions in B-decays. The fundamental predictions are based on just one length scale and the fine structure constant. More particular predictions rely also on the weak mixing angle and the up-down quark flavour mixing matrix element. With differential forms on the measure-scaled wavefunction, we could generate approximate parton distribution functions for the u and d valence quarks of the proton that compare well with established experimental analysis.
Sistemas de Lie y sus aplicaciones en Física y Teoría de Control
Arturo Ramos
2011-06-19T23:59:59.000Z
Doctoral Thesis, year 2002, about Lie systems and applications in Physics and Control Theory. The text is in English. Advisor: Jos\\'e F. Cari\\~nena
Analysis of the optics of the Final Focus Test Beam using Lie algebra based techniques
Roy, G.J.
1992-09-01T23:59:59.000Z
This report discusses the analysis of the beam optics of the final focus test beam at the Stanford Linear Collider using Lie algebra. (LSP).
Adjustable permanent magnet assembly for NMR and MRI
Pines, Alexander; Paulsen, Jeffrey; Bouchard, Louis S; Blumich, Bernhard
2013-10-29T23:59:59.000Z
System and methods for designing and using single-sided magnet assemblies for magnetic resonance imaging (MRI) are disclosed. The single-sided magnet assemblies can include an array of permanent magnets disposed at selected positions. At least one of the permanent magnets can be configured to rotate about an axis of rotation in the range of at least +/-10 degrees and can include a magnetization having a vector component perpendicular to the axis of rotation. The single-sided magnet assemblies can further include a magnet frame that is configured to hold the permanent magnets in place while allowing the at least one of the permanent magnets to rotate about the axis of rotation.
Equivalence of Control Systems with Linear Systems on Lie Groups and Homogeneous Spaces
Paris-Sud XI, Université de
Equivalence of Control Systems with Linear Systems on Lie Groups and Homogeneous Spaces Philippe of geometric control theory arguments. Keywords: Lie groups; Homogeneous spaces; Linear systems; Com- plete JOUAN 28th November 2008 Abstract The aim of this paper is to prove that a control affine system
Paris-Sud XI, Université de
DISCRETE EXTENDED KALMAN FILTER ON LIE GROUPS Guillaume Bourmaud, Rémi Mégret, Audrey Giremus, 33405 Talence cedex, France ABSTRACT In this paper, we generalize the Discrete Extended Kalman Filter (D called Discrete Extended Kalman Filter on Lie Groups (D- LG-EKF). It assumes that the posterior
J. Abedi-Fardad; A. Rezaei-Aghdam; Gh. Haghighatdoost
2014-05-26T23:59:59.000Z
We construct integrable and superintegrable Hamiltonian systems using the realizations of four dimensional real Lie algebras as a symmetry of the system with the phase space R4 and R6. Furthermore, we construct some integrable and superintegrable Hamiltonian systems for which the symmetry Lie group is also the phase space of the system.
Knowledge discovery using data mined from Nuclear Magnetic
Narasayya, Vivek
Knowledge discovery using data mined from Nuclear Magnetic Resonance spectral images William J cyberinfrastructure · Method Solid State ab initio calculations Nuclear Magnetic Resonance (NMR) Support Vector refined (and/or relaxed) structure, perform Self-Consistent Field calculation for electronic structure
The interplay of long-range magnetic order and single-ion anisotropy in rare earth nickel germanides
Islam, Z.
1999-05-10T23:59:59.000Z
This dissertation is concerned with the interplay of long-range order and anisotropy in the tetragonal RNi{sub 2}Ge{sub 2} (R = rare earth) family of compounds. Microscopic magnetic structures were studied using both neutron and x-ray resonant exchange scattering (XRES) techniques. The magnetic structures of Tb, Dy, Eu and Gd members have been determined using high-quality single-crystal samples. This work has correlated a strong Fermi surface nesting to the magnetic ordering in the RNi{sub 2}Ge{sub 2} compounds. Generalized susceptibility, {chi}{sub 0}(q), calculations found nesting to be responsible for both incommensurate ordering wave vector in GdNi{sub 2}Ge{sub 2}, and the commensurate structure in EuNi{sub 2}Ge{sub 2}. A continuous transition from incommensurate to commensurate magnetic structures via band filling is predicted. The surprisingly higher T{sub N} in EuNi{sub 2}Ge{sub 2} than that in GdNi{sub 2}Ge{sub 2} is also explained. Next, all the metamagnetic phases in TbNi{sub 2}Ge{sub 2} with an applied field along the c axis have been characterized with neutron diffraction measurements. A mixed phase model for the first metamagnetic structure consisting of fully-saturated as well as reduced-moment Tb ions is presented. The moment reduction may be due to moment instability which is possible if the exchange is comparable to the low-lying CEF level splitting and the ground state is a singlet. In such a case, certain Tb sites may experience a local field below the critical value needed to reach saturation.
On the magnetic order of Gd{sub 5}Ge{sub 3}
Cadogan, J. M. [School of Physical, Environmental and Mathematical Sciences, UNSW Canberra at the Australian Defence Force Academy, Canberra, ACT BC 2610 (Australia); Ryan, D. H., E-mail: dhryan@physics.mcgill.ca [Physics Department and Centre for the Physics of Materials, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Mudryk, Ya.; Pecharsky, V. K.; Gschneidner, K. A. [Ames Laboratory of the U.S. Department of Energy, Iowa State University, Ames, Iowa 50011-3020, USA and Department of Materials Science and Engineering, Iowa State University, Ames, Iowa 50011-2300 (United States)
2014-05-07T23:59:59.000Z
We have investigated the magnetic structure of Gd{sub 5}Ge{sub 3} by neutron powder diffraction down to 3.6?K. This compound presents three events in the heat capacity which we show are related to fundamental changes in the magnetic order. The primary antiferromagnetic ordering occurs at 82(2) K and produces a magnetic cell that is tripled with respect to the underlying orthorhombic crystal cell. The propagation vector is k{sub 1}=[0?0?1/3 ]. At 74(2) K, the magnetic order becomes “anti-C” with a propagation vector k{sub 2}?=?[1 0 0]. A third change in the magnetic order occurs at 40(2) K, and the new magnetic structure is essentially the “anti-C” structure but with the addition of a tripled magnetic component corresponding to a propagation vector k{sub 3}?=?[1/3 ?0?0].
DAMAGE LOCALIZATION USING LOAD VECTORS Dionisio Bernal
Bernal, Dionisio
DAMAGE LOCALIZATION USING LOAD VECTORS Dionisio Bernal Associate Professor Department of Civil: A technique to localize damage in structures that can be treated as linear in the pre and post-damage state is presented. Central to the approach is the computation of a set of vectors, designated as Damage Locating
Vector particles tunneling from BTZ black holes
Ge-Rui Chen; Shiwei Zhou; Yong-Chang Huang
2014-09-21T23:59:59.000Z
In this paper we investigate vector particles' Hawking radiation from a BTZ black hole. By applying the WKB approximation and the Hamilton-Jacobi Ansatz to the Proca equation, we obtain the tunneling spectrum of vector particles. The expected Hawking temperature is recovered.
Wavelet Transforms for Vector Fields Using Omnidirectionally Balanced Multiwavelets
Fowler, James E.
Wavelet Transforms for Vector Fields Using Omnidirectionally Balanced Multiwavelets James E. Fowler, Senior Member, IEEE, and Li Hua, Student Member, IEEE Abstract--Vector wavelet transforms for vector implementation of a vector wavelet transform, namely the application of a scalar transform to each vector
THE MAGNETIC ENERGY-HELICITY DIAGRAM OF SOLAR ACTIVE REGIONS
Tziotziou, Kostas; Georgoulis, Manolis K. [Research Center for Astronomy and Applied Mathematics (RCAAM), Academy of Athens, 4 Soranou Efesiou Street, Athens, GR-11527 (Greece); Raouafi, Nour-Eddine [Johns Hopkins University Applied Physics Laboratory (JHU/APL), 11100 Johns Hopkins Rd. Laurel, MD 20723-6099 (United States)
2012-11-01T23:59:59.000Z
Using a recently proposed nonlinear force-free method designed for single-vector magnetograms of solar active regions, we calculate the instantaneous free magnetic energy and relative magnetic helicity budgets in 162 vector magnetograms corresponding to 42 different active regions. We find a statistically robust, monotonic correlation between the free magnetic energy and the relative magnetic helicity in the studied regions. This correlation implies that magnetic helicity, in addition to free magnetic energy, may be an essential ingredient for major solar eruptions. Eruptive active regions appear well segregated from non-eruptive ones in both free energy and relative helicity with major (at least M-class) flares occurring in active regions with free energy and relative helicity exceeding 4 Multiplication-Sign 10{sup 31} erg and 2 Multiplication-Sign 10{sup 42} Mx{sup 2}, respectively. The helicity threshold agrees well with estimates of the helicity contents of typical coronal mass ejections.
Protostellar Accretion Flows Destabilized by Magnetic Flux Redistribution
Krasnopolsky, Ruben; Shang, Hsien; Zhao, Bo
2012-01-01T23:59:59.000Z
Magnetic flux redistribution lies at the heart of the problem of star formation in dense cores of molecular clouds that are magnetized to a realistic level. If all of the magnetic flux of a typical core were to be dragged into the central star, the stellar field strength would be orders of magnitude higher than the observed values. This well-known "magnetic flux problem" can in principle be resolved through non-ideal MHD effects. Two dimensional (axisymmetric) calculations have shown that ambipolar diffusion, in particular, can transport magnetic flux outward relative to matter, allowing material to enter the central object without dragging the field lines along. We show through simulations that such axisymmetric protostellar accretion flows are unstable in three dimensions to magnetic interchange instability in the azimuthal direction. The instability is driven by the magnetic flux redistributed from the matter that enters the central object. It typically starts to develop during the transition from the pres...
Monte Carlo Filtering on Lie Groups Alessandro Chiuso 1 and Stefano Soatto 2
Soatto, Stefano
Monte Carlo Filtering on Lie Groups Alessandro Chiuso 1 and Stefano Soatto 2 Abstract We propose to be consistent with the updated conditional distribution. The algorithm proposed, like other Monte Carlo methods
Low-Lying Isomers of the B9- Boron Cluster: The Planar Molecular...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Isomers of the B9- Boron Cluster: The Planar Molecular Wheel Versus Three-Dimensional Structures. Low-Lying Isomers of the B9- Boron Cluster: The Planar Molecular Wheel Versus...
Poynting-vector based method for determining the bearing and location of electromagnetic sources
Simons, David J. (Modesto, CA); Carrigan, Charles R. (Tracy, CA); Harben, Philip E. (Livermore, CA); Kirkendall, Barry A. (Golden, CO); Schultz, Craig A. (Danville, CA)
2008-10-21T23:59:59.000Z
A method and apparatus is utilized to determine the bearing and/or location of sources, such as, alternating current (A.C.) generators and loads, power lines, transformers and/or radio-frequency (RF) transmitters, emitting electromagnetic-wave energy for which a Poynting-Vector can be defined. When both a source and field sensors (electric and magnetic) are static, a bearing to the electromagnetic source can be obtained. If a single set of electric (E) and magnetic (B) sensors are in motion, multiple measurements permit location of the source. The method can be extended to networks of sensors allowing determination of the location of both stationary and moving sources.
Skadron, Kevin
-spin- rate flywheel. This application is representative of many control environments that require both high. Keywords Active magnetic bearing, flywheel, vector instructions, API, multi-threaded execution. 1-speed, energy-storage flywheel, and the purpose of the testbed is to provide a platform in which new
Parameter estimation of vector controlled induction machine
Rahman, Tahmid Ur
2002-01-01T23:59:59.000Z
and operation at low speed, indirect vector control is becoming popular. But as the rotor time constant varies the detuning of the control system occurs. Without exact rotor time constant the slip frequency calculation becomes inexact. In this thesis most...
Emergence of generalized seniority in low-lying states with random interactions
Lei, Y.; Xu, Z. Y. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhao, Y. M. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 730000 (China); Pittel, S. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Arima, A. [Department of Physics, Shanghai Jiao Tong University, Shanghai 200240 (China); Science Museum, Japan Science Foundation, 2-1 Kitanomaru-koen, Chiyoda ku, Tokyo 102-0091 (Japan)
2011-02-15T23:59:59.000Z
We study the generalized seniority properties of the low-lying states of two semimagic pseudonuclei {sup 22}O and {sup 46}Ca in the presence of one- and two-body random interactions. When the single-particle splittings are sufficiently large, S-pair correlation is found to be important in the low-lying states of these systems in the presence of random interactions.
Vertices of Lie Modules Roger M. Bryant, Susanne Danz, Karin Erdmann, and Jrgen Mller
Mueller, JÃ¼rgen
Vertices of Lie Modules Roger M. Bryant, Susanne Danz, Karin Erdmann, and JÃ¼rgen MÃ¼ller September 9 studied by Erdmann#21;Tan [14], and by Bryant#21;Lim#21;Tan [5]. By [5, Thm. 1.2], one has dim(Lie pr F (n to the principal block of FS n , and Bryant#21;Erdmann [4] have studied indecomposable direct sum decompositions
Vertices of Lie Modules Roger M. Bryant, Susanne Danz, Karin Erdmann, and J#rgen M#ller
Mueller, JÃ¼rgen
Vertices of Lie Modules Roger M. Bryant, Susanne Danz(LieprF(n))= dim(LieF(n)) has re* *cently been studied by Erdmann~Tan [14], and by Bryant~Lim~Tan [5]. By [5, Thm LiepfF(n) of LieF(n) always belongs to the principal block of F Sn, and Bryant~* *Erdmann [4] have
Killing vector fields and harmonic superfield theories
Groeger, Josua, E-mail: groegerj@mathematik.hu-berlin.de [Humboldt-Universität zu Berlin, Institut für Mathematik, Rudower Chaussee 25, 12489 Berlin (Germany)
2014-09-15T23:59:59.000Z
The harmonic action functional allows a natural generalisation to semi-Riemannian supergeometry, also referred to as harmonic, which resembles the supersymmetric sigma models studied in high energy physics. We show that Killing vector fields are infinitesimal supersymmetries of this harmonic action and prove three different Noether theorems in this context. En passant, we provide a homogeneous treatment of five characterisations of Killing vector fields on semi-Riemannian supermanifolds, thus filling a gap in the literature.
Bath, G.D.; Jahren, C.E.; Rosenbaum, J.G. [Geological Survey, Denver, CO (USA); Baldwin, M.J. [Fenix and Scisson, Inc., Mercury, NV (USA)
1983-12-31T23:59:59.000Z
Air and ground magnetic anomalies in the Climax stock area of the NTS help define the gross configuration of the stock and detailed configuration of magnetized rocks at the Boundary and Tippinip faults that border the stock. Magnetizations of geologic units were evaluated by measurements of magnetic properties of drill core, minimum estimates of magnetizations from ground magnetic anomalies for near surface rocks, and comparisons of measured anomalies with anomalies computed by a three-dimensional forward program. Alluvial deposits and most sedimentary rocks are nonmagnetic, but drill core measurements reveal large and irregular changes in magnetization for some quartzites and marbles. The magnetizations of quartz monzonite and granodiorite near the stock surface are weak, about 0.15 A/m, and increase at a rate of 0.00196 A/m/m to 1.55 A/m, at depths greater than 700 m (2300 ft). The volcanic rocks of the area are weakly magnetized. Aeromagnetic anomalies 850 m (2800 ft) above the stock are explained by a model consisting of five vertical prisms. Prisms 1, 2, and 3 represent the near surface outline of the stock, prism 4 is one of the models developed by Whitehill (1973), and prism 5 is modified from the model developed by Allingham and Zietz (1962). Most of the anomaly comes from unsampled and strongly-magnetized deep sources that could be either granite or metamorphosed sedimentary rocks. 48 refs., 23 figs., 3 tabs.
B --> rho K* decays and other rare vector-vector modes
G. Vasseur
2007-04-03T23:59:59.000Z
The recent analyses of the following rare vector-vector decays of the B meson are presented: rho K*, omega K*, omega rho, omega omega, and omega phi charmless final states. The latest results indicate that the fraction of longitudinal polarization is about 0.5 in penguin-dominated modes and close to 1 for tree-dominated modes.
Magnetic Field Safety Magnetic Field Safety
McQuade, D. Tyler
Magnetic Field Safety Training #12;Magnetic Field Safety Strong Magnetic Fields exist around energized magnets. High magnetic fields alone are a recognized hazard only for personnel with certain medical conditions such as pacemakers, magnetic implants, or embedded shrapnel. In addition, high magnetic
Thomas R. Hemmert; Ulf-G. Meissner; Sven Steininger
1998-11-09T23:59:59.000Z
We present an analytic and parameter-free expression for the momentum dependence of the strange magnetic form factor of the nucleon and its corresponding radius which has been derived in Heavy Baryon Chiral Perturbation Theory. We also discuss a model-independent relation between the isoscalar magnetic and the strange magnetic form factors of the nucleon based on chiral symmetry and SU(3) only. These limites are used to derive bounds on the strange magnetic moment of the proton from the recent measurement by the SAMPLE collaboration.
Covariant Lyapunov vectors for rigid disk systems
Hadrien Bosetti; Harald A. Posch
2010-06-30T23:59:59.000Z
We carry out extensive computer simulations to study the Lyapunov instability of a two-dimensional hard disk system in a rectangular box with periodic boundary conditions. The system is large enough to allow the formation of Lyapunov modes parallel to the x axis of the box. The Oseledec splitting into covariant subspaces of the tangent space is considered by computing the full set of covariant perturbation vectors co-moving with the flow in tangent-space. These vectors are shown to be transversal, but generally not orthogonal to each other. Only the angle between covariant vectors associated with immediate adjacent Lyapunov exponents in the Lyapunov spectrum may become small, but the probability of this angle to vanish approaches zero. The stable and unstable manifolds are transverse to each other and the system is hyperbolic.
Glenn E. Ciolek; Shantanu Basu
2000-09-18T23:59:59.000Z
We review theoretical models of the early stages of star formation, in which gravitational collapse is strongly regulated by magnetic fields and the associated process of ambipolar diffusion. We discuss results of numerical simulations and analytical studies of core formation and collapse, which can be directly tested against observation. We also focus on recent data which are relevant to this theory of star formation, such as: observations of extended infall in protostellar cores, estimates of evolutionary timescales ~ 1 Myr for cores, measured mass-to-flux ratios of cores, and the relative alignment of polarization vectors with apparent cloud elongation. It is shown that in all of these areas, the data lie within the observationally allowable range of parameter space. Other areas of interest (protostellar accretion rates and the presence of core edges) and issues that remain unresolved or under study (the role of non-thermal motions and cluster formation) are also discussed. Moreover, we highlight some differences between our model predictions and those of highly turbulent star formation models, and discuss how these differences can be distinguished observationally.
(New hosts and vectors for genome cloning)
Not Available
1991-01-01T23:59:59.000Z
The main goal of our project remains the development of new bacterial hosts and vectors for the stable propagation of human DNA clones in E. coli. During the past six months of our current budget period, we have (1) continued to develop new hosts that permit the stable maintenance of unstable features of human DNA, and (2) developed a series of vectors for (a) cloning large DNA inserts, (b) assessing the frequency of human sequences that are lethal to the growth of E. coli, and (c) assessing the stability of human sequences cloned in M13 for large-scale sequencing projects.
A multistage approach to vector quantization
Bellubbi, Rajeev V.
1992-01-01T23:59:59.000Z
. Grubbs, Jr (Member) J. W. Howze (Head of Department) August 1992 ABSTRACT A Multistage Approach to Vector Quantization. (August 1992) Rajeev V. Bellubbi, B. E. , Bangalore University; India Chair of Advisory Committee: Dr. Vinay Vaishampayan We... is achieved by coding vectors instead of scalars. This fact is true for mem- Journal model is IEEE Transactions on Automatic Controk oryless dais, sonrc& s as w& II as I'or so?r?s with memory. Cloud design tech?iques I'or v&'ctor co&I&'rs &v&sne v& ly...
Chiral Magnetic Effect in QED induced by longitudinal photons
J. L. Acosta Avalo; H. Perez Rojas
2015-02-26T23:59:59.000Z
We demonstrate the existence of the chiral magnetic effect in an electron-positron magnetized gas. A pseudo-vector(conserved)Ohm current is induced by the electric field related to the longitudinal QED mode propagating parallel to the external magnetic field $\\textbf{B}$ and separating opposite charges of the same heliticity. From a relation between axial and electromagnetic currents we obtain a non-conserved current leading to an expression close to the usual axial anomaly. The effect is interesting in connection to the QCD chiral magnetic case reported in current literature.
Kerns, J.A.; Stone, R.R.; Fabyan, J.
1985-02-12T23:59:59.000Z
A magnetically-conductive filler material bridges the gap between a multi-part magnetic shield structure which substantially encloses a predetermined volume so as to minimize the ingress or egress of magnetic fields with respect to that volume. The filler material includes a heavy concentration of single-magnetic-domain-sized particles of a magnetically conductive material (e.g. soft iron, carbon steel or the like) dispersed throughout a carrier material which is generally a non-magnetic material that is at least sometimes in a plastic or liquid state. The maximum cross-sectional particle dimension is substantially less than the nominal dimension of the gap to be filled. An epoxy base material (i.e. without any hardening additive) low volatility vacuum greases or the like may be used for the carrier material. The structure is preferably exposed to the expected ambient field while the carrier is in a plastic or liquid state so as to facilitate alignment of the single-magnetic-domain-sized particles with the expected magnetic field lines.
Magnetic Fields in Quantum Degenerate Systems and in Vacuum
H. Perez Rojas; E. Rodriguez Querts
2006-12-28T23:59:59.000Z
We consider self-magnetization of charged and neutral vector bosons bearing a magnetic moment in a gas and in vacuum. For charged vector bosons (W bosons) a divergence of the magnetization in both the medium and the electroweak vacuum occurs for the critical field B=B_{wc}=m_{w}^{2}/e. For B>B_{wc} the system is unstable. This behavior suggests the occurrence of a phase transition at B=B_{c}, where the field is self-consistently maintained. This mechanism actually prevents $B$ from reaching the critical value B_{c}. For virtual neutral vector bosons bearing an anomalous magnetic moment, the ground state has a similar behavior for B=B_{nbc}=m_{nb}^{2}/q . The magnetization in the medium is associated to a Bose-Einstein condensate and we conjecture a similar condensate occurs also in the case of vacuum. The model is applied to virtual electron-positron pairs bosonization in a magnetic field B \\sim B_{pc}\\lesssim 2m_{e}^{2}/e, where m_e is the electron mass. This would lead also to vacuum self-magnetization in QED, where in both cases the symmetry breaking is due to a condensate of quasi-massless particles.
Matsui, Hiroshi (Glen Rock, NJ); Matsunaga, Tadashi (Tokyo, JP)
2010-11-16T23:59:59.000Z
A magnetic nanotube includes bacterial magnetic nanocrystals contacted onto a nanotube which absorbs the nanocrystals. The nanocrystals are contacted on at least one surface of the nanotube. A method of fabricating a magnetic nanotube includes synthesizing the bacterial magnetic nanocrystals, which have an outer layer of proteins. A nanotube provided is capable of absorbing the nanocrystals and contacting the nanotube with the nanocrystals. The nanotube is preferably a peptide bolaamphiphile. A nanotube solution and a nanocrystal solution including a buffer and a concentration of nanocrystals are mixed. The concentration of nanocrystals is optimized, resulting in a nanocrystal to nanotube ratio for which bacterial magnetic nanocrystals are immobilized on at least one surface of the nanotubes. The ratio controls whether the nanocrystals bind only to the interior or to the exterior surfaces of the nanotubes. Uses include cell manipulation and separation, biological assay, enzyme recovery, and biosensors.
Shape mixing dynamics in the low-lying states of proton-rich Kr isotopes
Koichi Sato; Nobuo Hinohara
2010-06-18T23:59:59.000Z
We study the oblate-prolate shape mixing in the low-lying states of proton-rich Kr isotopes using the five-dimensional quadrupole collective Hamiltonian. The collective Hamiltonian is derived microscopically by means of the CHFB (constrained Hartree-Fock-Bogoliubov) + Local QRPA (quasiparticle random phase approximation) method, which we have developed recently on the basis of the adiabatic self-consistent collective coordinate method. The results of the numerical calculation show the importance of large-amplitude collective vibrations in the triaxial shape degree of freedom and rotational effects on the oblate-prolate shape mixing dynamics in the low-lying states of these isotopes.
Song, Yongliang
2015-01-01T23:59:59.000Z
It is generally believed that the evolution of magnetic helicity has a close relationship with solar activity. Before the launch of SDO, earlier studies have mostly used MDI/SOHO line of sight magnetograms and assumed that magnetic fields are radial when calculating magnetic helicity injection rate from photospheric magnetograms. However, this assumption is not necessarily true. Here we use the vector magnetograms and line of sight magnetograms, both taken by HMI/SDO, to estimate the effects of non-radial magnetic field on measuring magnetic helicity injection rate. We find that: 1) The effect of non-radial magnetic field on estimating tangential velocity is relatively small; 2) On estimating magnetic helicity injection rate, the effect of non-radial magnetic field is strong when active regions are observed near the limb and is relatively small when active regions are close to disk center; 3) The effect of non-radial magnetic field becomes minor if the amount of accumulated magnetic helicity is the only conce...
Support Vector Machines with Example Dependent Costs
Brefeld, Ulf
Support Vector Machines with Example Dependent Costs Ulf Brefeld, Peter Geibel, and Fritz Wysotzki neu- ral networks and machine learning, typically, do not take any costs into account or allow only costs depending on the classes of the examples that are used for learning. As an extension of class
Hessian structures, Euler vector fields, and thermodynamics
M. Á. García-Ariza
2015-03-02T23:59:59.000Z
In this paper, a geometric structure which generalizes that of thermodynamics is presented; spaces of equilibrium states are portrayed as a particular case of the former. For this end, concepts like Euler vector field and extensive function, which are usual in thermodynamics, are introduced in a wider context.
Averages in vector spaces over finite fields
Wright J.; Carbery A.; Stones B.
2008-01-01T23:59:59.000Z
We study the analogues of the problems of averages and maximal averages over a surface in R-n when the euclidean structure is replaced by that of a vector space over a finite field, and obtain optimal results in a number ...
Spatial resolution in vector potential photoelectron microscopy
Browning, R. [R. Browning Consultants, 1 Barnhart Place, Shoreham, New York 11786 (United States)] [R. Browning Consultants, 1 Barnhart Place, Shoreham, New York 11786 (United States)
2014-03-15T23:59:59.000Z
The experimental spatial resolution of vector potential photoelectron microscopy is found to be much higher than expected because of the cancellation of one of the expected contributions to the point spread function. We present a new calculation of the spatial resolution with support from finite element ray tracing, and experimental results.
Note: Vector reflectometry in a beam waveguide
Eimer, J. R.; Bennett, C. L. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Chuss, D. T.; Wollack, E. J. [NASA Goddard Space Flight Center, Code 665, Greenbelt, Maryland 20771 (United States)
2011-08-15T23:59:59.000Z
We present a one-port calibration technique for characterization of beam waveguide components with a vector network analyzer. This technique involves using a set of known delays to separate the responses of the instrument and the device under test. We demonstrate this technique by measuring the reflected performance of a millimeter-wave variable-delay polarization modulator.
Magnets & Magnet Condensed Matter Science
McQuade, D. Tyler
18 No. 1 CONDENSED MATTER SCIENCE Technique development, graphene, magnetism & magnetic materials Pressure 9 Metal to Insulator Transition on the N=0 Landau Level in Graphene 10 Evidence for Fractional Quantum Hall States in Suspended Bilayer and Trilayer Graphene 11 Fractional Quantum Hall Effect
Can (electric-magnetic) duality be gauged?
Bunster, Claudio [Centro de Estudios Cientificos (CECS), Casilla 1469, Valdivia (Chile); Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Muehlenberg 1, D-14476 Potsdam (Germany); Henneaux, Marc [Centro de Estudios Cientificos (CECS), Casilla 1469, Valdivia (Chile); Universite Libre de Bruxelles and International Solvay Institutes, ULB-Campus Plaine CP231, B-1050 Brussels (Belgium); Max-Planck-Institut fuer Gravitationsphysik (Albert-Einstein-Institut), Muehlenberg 1, D-14476 Potsdam (Germany)
2011-02-15T23:59:59.000Z
There exists a formulation of the Maxwell theory in terms of two vector potentials, one electric and one magnetic. The action is then manifestly invariant under electric-magnetic duality transformations, which are rotations in the two-dimensional internal space of the two potentials, and local. We ask the question: Can duality be gauged? The only known and battle-tested method of accomplishing the gauging is the Noether procedure. In its decanted form, it amounts to turning on the coupling by deforming the Abelian gauge group of the free theory, out of whose curvatures the action is built, into a non-Abelian group which becomes the gauge group of the resulting theory. In this article, we show that the method cannot be successfully implemented for electric-magnetic duality. We thus conclude that, unless a radically new idea is introduced, electric-magnetic duality cannot be gauged. The implication of this result for supergravity is briefly discussed.
Kjall, Jonas Alexander
2012-01-01T23:59:59.000Z
Magnetism in Ultracold Gases 4 Magnetic phase diagram of aMagnetism . . . . . . . . . . . .1.3 Magnetism in condensedIntroduction 1 Brief introduction to magnetism 1.1 Classic
Isospectral Metrics on Classical Compact Simple Lie Groups Submitted to the Faculty
Proctor, Emily
Isospectral Metrics on Classical Compact Simple Lie Groups A Thesis Submitted to the Faculty;Acknowledgements This thesis is the product of support from a number of people. First and foremost, it has been. I give thanks to Peter Doyle for leading me out of a blind alley, to Dorothee Schueth for helping me
A Robust Audio Classification and Segmentation Method Lie Lu, Hao Jiang and HongJiang Zhang
Jiang, Hao
A Robust Audio Classification and Segmentation Method Lie Lu, Hao Jiang and HongJiang Zhang for audio classification that is capable of segmenting and classifying an audio stream into speech, music, environment sound and silence. Audio classification is processed in two steps, which makes it suitable
Vision-Based Control on Lie groups with Application to Needle Steering
Vision-Based Control on Lie groups with Application to Needle Steering by Vinutha Kallem steering and (2) kernel-based visual servoing. The core of this thesis is motivated by image-guided control model of flexible bevel-tip needle steering in which the needle is inserted and rotated at its base
A Note on Gauge Systems from the Point of View of Lie Algebroids
Barnich, G. [Physique Theorique et Mathematique, Universite Libre de Bruxelles and International Solvay Institutes, Campus Plaine C.P. 231, B-1050 Bruxelles (Belgium)
2010-11-25T23:59:59.000Z
In the context of the variational bi-complex, we re-explain that irreducible gauge systems define a particular example of a Lie algebroid. This is used to review some recent and not so recent results on gauge, global and asymptotic symmetries.
Thompson's conjecture for real semisimple Lie groups JiangHua Lu # and Sam Evens +
Evens, Sam
Thompson's conjecture for real semiÂsimple Lie groups JiangÂHua Lu # and Sam Evens + June 13, 2005 Dedicated to Professor Alan Weinstein for his 60th birthday Abstract A proof of Thompson's conjecture geometry. 1 Introduction Thompson's conjecture [T] for the group GL(n, C), which relates eigenvalues
Coverage of Wireless Sensor Networks Guo-Lie Lan 1,2
Ma, Zhi-Ming
Coverage of Wireless Sensor Networks Guo-Lie Lan 1,2 and Zhi-Ming Ma1 and Su-Yong Sun 1,2 1, sensor network, large-scale, wireless, uniform distribution. 1 Introduction Recently, there has been a growing interest in studying large-scale wireless sensor networks. Such a network consists of a large
THE RICCI BRACKET FLOW FOR SOLVABLE LIE GROUPS KEVIN KOZLOWSKI AND BRENNAN VINCENT
Young, Andrea
, and the bracket is derived from the group multiplication. For all n-dimensional Lie groups G, TeG is isomorphic, but rather in the bracket. If we pick the inner product on TeG to be the standard inner product on Rn , we
Grupos de Lie, CIMAT, agsto-dic, 2007 Notas num. 2
Bor, Gil
invariantes por la izquierda TeG. La correspondencia est´a dada por (0), X X(e). Definici´on. La ´algebra de Lie de G es el espacio tangente TeG equipado con el corchete inducido por la identificaci´on con
Optimization and Large Scale Learning Optimization lies at the heart of almost every machine
Optimization and Large Scale Learning Optimization lies at the heart of almost every machine these facets requires optimization techniques tailored to not only respect them but to ag- gressively exploit by looking at the recent book [1] (MIT Press, 2011), or at the follow- ing workshops: (i) "Optimization
Low-lying levels in Cu-57 and the rp process
Zhou, XG; Dejbakhsh, H.; Gagliardi, Carl A.; Jiang, J.; Trache, L.; Tribble, Robert E.
1996-01-01T23:59:59.000Z
. In particular, a comparison of the low-lying levels of 57Cu with the well-determined excited states of its mirror nucleus 57Ni is important for studying the charge symmetry of the nucleus. The structure of 57Cu also plays a key role in the nucleo- synthesis...
Rev. of Keaton: The Man Who Wouldn't Lie Down, by Tom Dardis
Levine, Stuart
1981-01-01T23:59:59.000Z
: No. 41: Janet Lewis by Charles L. Crow; No. 42: Tom Rob bins by Mark Siegel; No. 43: Joaquin Miller by Benjamin S. Lawson; No. 44: Dorothy Johnson by Judy Alter; No. 45: Leslie Marmon Silko by Per Seyersted. KEATON: The Man Who Wouldn't Lie...
Coherent states, quantum gravity and the Born-Oppenheimer approximation, II: Compact Lie Groups
Alexander Stottmeister; Thomas Thiemann
2015-04-09T23:59:59.000Z
In this article, the second of three, we discuss and develop the basis of a Weyl quantisation for compact Lie groups aiming at loop quantum gravity-type models. This Weyl quantisation may serve as the main mathematical tool to implement the program of space adiabatic perturbation theory in such models. As we already argued in our first article, space adiabatic perturbation theory offers an ideal framework to overcome the obstacles that hinder the direct implementation of the conventional Born-Oppenheimer approach in the canonical formulation of loop quantum gravity. Additionally, we conjecture the existence of a new form of the Segal-Bargmann-Hall "coherent state" transform for compact Lie groups $G$, which we prove for $G=U(1)^{n}$ and support by numerical evidence for $G=SU(2)$. The reason for conjoining this conjecture with the main topic of this article originates in the observation, that the coherent state transform can be used as a basic building block of a coherent state quantisation (Berezin quantisation) for compact Lie groups $G$. But, as Weyl and Berezin quantisation for $\\mathbb{R}^{2d}$ are intimately related by heat kernel evolution, it is natural to ask, whether a similar connection exists for compact Lie groups, as well. Moreover, since the formulation of space adiabatic perturbation theory requires a (deformation) quantisation as minimal input, we analyse the question to what extent the coherent state quantisation, defined by the Segal-Bargmann-Hall transform, can serve as basis of the former.
Ingram, Kevin
2006-01-01T23:59:59.000Z
Sanford, Lost Lexicon: Secret Meanings in the Vocabulary ofOF CALIFORNIA, SAN DIEGO Secret Lives, Public Lies: TheChapter 6: Diego Velázquez’s Secret History…………………………………
A MAGNETIC CALIBRATION OF PHOTOSPHERIC DOPPLER VELOCITIES
Welsch, Brian T.; Fisher, George H. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Sun, Xudong [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)
2013-03-10T23:59:59.000Z
The zero point of measured photospheric Doppler shifts is uncertain for at least two reasons: instrumental variations (from, e.g., thermal drifts); and the convective blueshift, a known correlation between intensity and upflows. Accurate knowledge of the zero point is, however, useful for (1) improving estimates of the Poynting flux of magnetic energy across the photosphere, and (2) constraining processes underlying flux cancellation, the mutual apparent loss of magnetic flux in closely spaced, opposite-polarity magnetogram features. We present a method to absolutely calibrate line-of-sight (LOS) velocities in solar active regions (ARs) near disk center using three successive vector magnetograms and one Dopplergram coincident with the central magnetogram. It exploits the fact that Doppler shifts measured along polarity inversion lines (PILs) of the LOS magnetic field determine one component of the velocity perpendicular to the magnetic field, and optimizes consistency between changes in LOS flux near PILs and the transport of transverse magnetic flux by LOS velocities, assuming that ideal electric fields govern the magnetic evolution. Previous calibrations fitted the center-to-limb variation of Doppler velocities, but this approach cannot, by itself, account for residual convective shifts at the limb. We apply our method to vector magnetograms of AR 11158, observed by the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory, and find clear evidence of offsets in the Doppler zero point in the range of 50-550 m s{sup -1}. In addition, we note that a simpler calibration can be determined from an LOS magnetogram and Dopplergram pair from the median Doppler velocity among all near-disk-center PIL pixels. We briefly discuss shortcomings in our initial implementation, and suggest ways to address these. In addition, as a step in our data reduction, we discuss the use of temporal continuity in the transverse magnetic field direction to correct apparently spurious fluctuations in resolution of the 180 Degree-Sign ambiguity.
Solar nebula magnetic fields recorded in the Semarkona meteorite
Fu, Roger R.; Weiss, Benjamin P.; Lima, Eduardo A.; Harrison, Richard J.; Bai, Xue-Ning; Desch, Steven J.; Ebel, Denton S.; Suavet, Clement; Wang, Huapei; Glenn, David; Le Sage, David; Kasama, Takeshi; Walsworth, Ronald L.; Kuan, Aaron T.
2014-11-13T23:59:59.000Z
images of all three vector 492 components of the magnetic field produced by the sample in the plane of NV sensors using 493 optically-detected magnetic resonance (ODMR) spectroscopy. In this technique, described by 494 Le Sage et al. (74... Figure 1. Dusty olivine-bearing chondrules from the Semarkona meteorite. (A) Optical 224 photomicrograph of chondrule DOC4 showing the location of dusty olivine grains. Image taken 225 in reflected light with crossed polarizers. (B) Annular...
Charmless Hadronic B Decays into Vector, Axial Vector and Tensor Final States at BaBar
Gandini, Paolo; /Milan U. /INFN, Milan
2012-04-06T23:59:59.000Z
We present experimental measurements of branching fraction and longitudinal polarization fraction in charmless hadronic B decays into vector, axial vector and tensor final states with the final dataset of BABAR. Measurements of such kind of decays are a powerful tool both to test the Standard Model and search possible sources of new physics. In this document we present a short review of the last experimental results at BABAR concerning charmless quasi two-body decays in final states containing particles with spin 1 or spin 2 and different parities. This kind of decays has received considerable theoretical interest in the last few years and this particular attention has led to interesting experimental results at the current b-factories. In fact, the study of longitudinal polarization fraction f{sub L} in charmless B decays to vector vector (VV), vector axial-vector (VA) and axial-vector axial-vector (AA) mesons provides information on the underlying helicity structure of the decay mechanism. Naive helicity conservation arguments predict a dominant longitudinal polarization fraction f{sub L} {approx} 1 for both tree and penguin dominated decays and this pattern seems to be confirmed by tree-dominated B {yields} {rho}{rho} and B{sup +} {yields} {Omega}{rho}{sup +} decays. Other penguin dominated decays, instead, show a different behavior: the measured value of f{sub L} {approx} 0.5 in B {yields} {phi}K* decays is in contrast with naive Standard Model (SM) calculations. Several solutions have been proposed such as the introduction of non-factorizable terms and penguin-annihilation amplitudes, while other explanations invoke new physics. New modes have been investigated to shed more light on the problem.
Controlling Magnetism at the Nanoscale
Wong, Jared
2012-01-01T23:59:59.000Z
Manipulation of Magnetism - External148 Conclusion A The Magnetism Cheat Sheet A.1 Magnetic157 A.2 Magnetism Unit Conversion
Characterization and removal of errors due to local magnetic anomalies in directional drilling of Geophysics, Colorado School of Mines Summary Directional drilling has evolved over the last few decades utilizes a technique known as magnetic Measurement While Drilling (MWD). Vector measurements of geomagnetic
Paris-Sud XI, UniversitÃ© de
Terms--Direct control, hybrid dynamic systems, perma- nent magnet synchronous machine (PMSM), physical magnet synchronous machine (PMSM) and a two-level voltage inverter (Fig. 1). The PMSM constitutes variables) so hybrid control strategies apply adequately. For PMSM drives, vector control has been
Orthogonal Sets of Vectors and the Gram-Schmidt Process
PRETEX (Halifax NS) #1 1054 1999 Mar 05 10:59:16
2010-02-12T23:59:59.000Z
Feb 16, 2007 ... 2007/2/16 page 323 i i i i. 4.12. Orthogonal Sets of Vectors and the Gram-Schmidt Process 323. 16. Using Equation (4.11.11), determine all vectors sat- isfying ?v ...
Chakrabarti, Sudipto; Pal, Amlan J., E-mail: sspajp@iacs.res.in [Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)
2014-01-06T23:59:59.000Z
We form a monolayer of magnetic organic molecules and immobilize their moments pointing either upwards or downwards with respect to the substrate through an electrostatic-binding process. Such a monolayer is probed with a scanning tunneling microscope tip, which is also magnetized with the magnetization vector pointing towards (or away from) apex of the tip. From spin-polarized tunneling current, we show that the current was higher when magnetization vectors of the tip and molecules were parallel as compared to that when they were anti-parallel. We show that for tunneling of spin-polarized electrons, aligned organic molecular magnets can act as a valve.
Neutrino magnetic moment in a magnetized plasma
N. V. Mikheev; E. N. Narynskaya
2010-11-08T23:59:59.000Z
The contribution of a magnetized plasma to the neutrino magnetic moment is calculated. It is shown that only part of the additional neutrino energy in magnetized plasma connecting with its spin and magnetic field strength defines the neutrino magnetic moment. It is found that the presence of magnetized plasma does not lead to the considerable increase of the neutrino magnetic moment in contrast to the results presented in literature previously.
Infinite Support Vector Machines in Speech Recognition
Yang, Jingzhou; van Dalien, Rogier C.; Gales, M. J. F.
2013-01-01T23:59:59.000Z
Infinite Support Vector Machines in Speech Recognition Jingzhou Yang, Rogier C. van Dalen and Mark Gales Department of Engineering, University of Cambridge Trumpington Street, Cambridge, CB2 1PZ, UK {jy308,rcv25,mjfg}@eng.cam.ac.uk Abstract... ., Secaucus, NJ, USA, 2006. [14] Carl Edward Rasmussen, “The infinite Gaussian mixture model,” in Advances in Neural Information Processing Systems 12. 2000, pp. 554–560, MIT Press. [15] Yee Whye Teh, “Dirichlet processes,” in Encyclopedia of Ma- chine...
NLO Vector Boson Production With Light Jets
Bern, Z.; Diana, G.; Dixon, L.J.; Febres Cordero, F.; Forde, D.; Gleisberg, T.; Hoeche, S.; Ita, H.; Kosower, D.A.; Maitre, D.; Ozeren, K.
2012-02-15T23:59:59.000Z
In this contribution we present recent progress in the computation of next-to-leading order (NLO) QCD corrections for the production of an electroweak vector boson in association with jets at hadron colliders. We focus on results obtained using the virtual matrix element library BlackHat in conjunction with SHERPA, focusing on results relevant to understanding the background to top production. The production of a vector boson in association with several jets at the Large Hadron Collider (LHC) is an important background for other Standard Model processes as well as new physics signals. In particular, the production of a W boson in association with many jets is an important background for processes involving one or more top quarks. Precise predictions for the backgrounds are crucial to measurement of top-quark processes. Vector boson production in association with multiple jets is also a very important background for many SUSY searches, as it mimics the signatures of many typical decay chains. Here we will discuss how polarization information can be used as an additional handle to differentiate top pair production from 'prompt' W-boson production. More generally, ratios of observables, for example for events containing a W boson versus those containing a Z boson, are expected to be better-behaved as many uncertainties cancel in such ratios. Precise calculation of ratios, along with measurement of one of the two processes in the ratio, can be used in data-driven techniques for estimating backgrounds.
Simons, Jack
Very Large Scale Computations of the Free Energies of Eight Low-Lying Structures of Arginine and free energies of five canonical and three zwitterionic low-lying structures of the arginine molecule have been used on state-of-the-art parallel computers. The electronic energy and Gibbs free energy
Petroglyphs, Lighting, and Magnetism
Walker, Merle F
2007-01-01T23:59:59.000Z
1950 Electricity and Magnetism: Theory and Applications.I Petroglyphs, Lightning, and Magnetism | Walker Figure 8.I Petroglyphs, Lightning, and Magnetism | Walker Figure IL
Nash Equilibrium Seeking in Multi-Vehicle Systems: A Lie Bracket Approximation-Based Approach
Dürr, Hans-Bernd; Johansson, Karl H
2011-01-01T23:59:59.000Z
We consider problems in multi-agent systems where a network of autonomous vehicles needs to self-organize such that some global objective function is maximized. To deal with the agents' lack of global information we define the problem as a potential game where the agents/players are only able to access local measurements of their individual utility functions whose parameters and detailed analytical forms may be unknown. We then propose a distributed and adaptive continuous-time algorithm, where each agent applies a local sinusoidal extremum seeking feedback adopted to its specific motion dynamics. By interpreting this multi-vehicle system as an input-affine system with periodic excitations and by using geometric methods based on Lie brackets, we calculate a simplified system which approximates the qualitative behavior of the original one better than existing methods, while only requiring twice differentiability of the utility functions. We show that the Lie bracket direction is directly related to the unknown...
Reconstruction of nuclear charged fragment trajectories from a large gap sweeper magnet
N. Frank; A. Schiller; D. Bazin; W. A. Peters; M. Thoennessen
2007-08-29T23:59:59.000Z
A new method to reconstruct charged fragment four-momentum vectors from measured trajectories behind an open, large gap, magnetic dispersion element (a sweeper magnet) has been developed. In addition to the position and angle behind the magnet it includes the position measurement in the dispersive direction at the target. The method improves the energy and angle resolution of the reconstruction significantly for experiments with fast rare isotopes, where the beam size at the target position is large.
Integration of geodesic flows on homogeneous spaces: the case of a wild lie group
A. A. Magazev; I. V. Shirokov
2007-03-21T23:59:59.000Z
We obtain necessary and sufficient conditions for the integrability in quadratures of geodesic flows on homogeneous spaces $M$ with invariant and central metrics. The proposed integration algorithm consists in using a special canonical transformation in the space $T^*M$ based on constructing the canonical coordinates on the orbits of the coadjoint representation and on the simplectic sheets of the Poisson algebra of invariant functions. This algorithm is applicable to integrating geodesic flows on homogeneous spaces of a wild Lie group.
Chaotic wave functions and exponential convergence of low-lying energy eigenvalues
Mihai Horoi; Alexander Volya; Vladimir Zelevinsky
1998-06-04T23:59:59.000Z
We suggest that low-lying eigenvalues of realistic quantum many-body hamiltonians, given, as in the nuclear shell model, by large matrices, can be calculated, instead of the full diagonalization, by the diagonalization of small truncated matrices with the exponential extrapolation of the results. We show numerical data confirming this conjecture. We argue that the exponential convergence in an appropriate basis may be a generic feature of complicated ("chaotic") systems where the wave functions are localized in this basis.
Fusion rules and complete reducibility of certain modules for affine Lie algebras
Drazen Adamovic; Ozren Perse
2013-03-26T23:59:59.000Z
We develop a new method for obtaining branching rules for affine Kac-Moody Lie algebras at negative integer levels. This method uses fusion rules for vertex operator algebras of affine type. We prove that an infinite family of ordinary modules for affine vertex algebra of type A investigated in Adamovi\\'c and O. Per\\v{s}e (2008) is closed under fusion. Then we apply these fusion rules on explicit bosonic realization of level -1 modules for the affine Lie algebra of type $A_{\\ell-1}^{(1)}$, obtain a new proof of complete reducibility for these representations, and the corresponding decomposition for $\\ell \\ge 3$. We also obtain the complete reducibility of the associated level -1 modules for affine Lie algebra of type $C_{\\ell}^{(1)}$. Next we notice that the category of $D_{2 \\ell -1}^{(1)}$ modules at level $- 2 \\ell +3 $ obtained in Per\\v{s}e (2012) has the isomorphic fusion algebra. This enables us to decompose certain $E_6 ^{(1)}$ and $F_4 ^{(1)}$--modules at negative levels.
Bouchard, Louis-Serge; Pines, Alexander; Demas, Vasiliki
2014-01-21T23:59:59.000Z
A system and method for Fourier encoding a nuclear magnetic resonance (NMR) signal is disclosed. A static magnetic field B.sub.0 is provided along a first direction. An NMR signal from the sample is Fourier encoded by applying a rotating-frame gradient field B.sub.G superimposed on the B.sub.0, where the B.sub.G comprises a vector component rotating in a plane perpendicular to the first direction at an angular frequency .omega.in a laboratory frame. The Fourier-encoded NMR signal is detected.
Magnetic Relativistic Schrödinger Operators and \\\\Imaginary-time Path Integrals
Takashi Ichinose
2014-03-24T23:59:59.000Z
Three magnetic relativistic Schr\\"odinger operators corresponding to the classical relativistic Hamiltonian symbol with magnetic vector and electric scalar potentials are considered, dependent on how to quantize the kinetic energy term $\\sqrt{(\\xi-A(x))^2 +m^2}$. We discuss their difference in general and their coincidence in the case of constant magnetic fields, and also study whether they are covariant under gauge transformation. Then results are reviewed on path integral representations for their respective imaginary-time relativistic Schr\\"odinger equations, i.e. heat equations, by means of the probability path space measure related to the L\\'evy process concerned.
Magnetic Catalysis vs Magnetic Inhibition
Kenji Fukushima; Yoshimasa Hidaka
2012-09-06T23:59:59.000Z
We discuss the fate of chiral symmetry in an extremely strong magnetic field B. We investigate not only quark fluctuations but also neutral meson effects. The former would enhance the chiral-symmetry breaking at finite B according to the Magnetic Catalysis, while the latter would suppress the chiral condensate once B exceeds the scale of the hadron structure. Using a chiral model we demonstrate how neutral mesons are subject to the dimensional reduction and the low dimensionality favors the chiral-symmetric phase. We point out that this effect, the Magnetic Inhibition, can be a feasible explanation for recent lattice-QCD data indicating the decreasing behavior of the chiral-restoration temperature with increasing B.
Thomas Wiegelmann; Bernd Inhester
2006-12-21T23:59:59.000Z
The space mission STEREO will provide images from two viewpoints. An important aim of the STEREO mission is to get a 3D view of the solar corona. We develop a program for the stereoscopic reconstruction of 3D coronal loops from images taken with the two STEREO spacecraft. A pure geometric triangulation of coronal features leads to ambiguities because the dilute plasma emissions complicates the association of features in image 1 with features in image 2. As a consequence of these problems the stereoscopic reconstruction is not unique and multiple solutions occur. We demonstrate how these ambiguities can be resolved with the help of different coronal magnetic field models (potential, linear and non-linear force-free fields). The idea is that, due to the high conductivity in the coronal plasma, the emitting plasma outlines the magnetic field lines. Consequently the 3D coronal magnetic field provides a proxy for the stereoscopy which allows to eliminate inconsistent configurations. The combination of stereoscopy and magnetic modelling is more powerful than one of these tools alone. We test our method with the help of a model active region and plan to apply it to the solar case as soon as STEREO data become available.
He Lung Imaging in an Open Access, Very-Low-Field Human Magnetic Resonance Imaging System
Walsworth, Ronald L.
3 He Lung Imaging in an Open Access, Very-Low-Field Human Magnetic Resonance Imaging System R. W. Butler,6 F. W. Hersman,4 and R. L. Walsworth1 The human lung and its functions are extremely sensitive lung restrict sub- jects to lying horizontally. Imaging of human lungs using inhaled laser-polarized 3
Superconducting Magnet Division
Superconducting Magnet Division DOE NP Program Review - July 06 1 Brookhaven Magnet Division - Nuclear Physics Program Support Activities Superconducting Magnet Program RHIC Operations Support Spin Summary Peter Wanderer, DOE review, July 25, 2006 Acting Head, Superconducting Magnet Division #12
Theoretical investigation of the magnetic structure in YBa_2Cu_3O_6
Ekkehard Krüger
2006-08-07T23:59:59.000Z
As experimentally well established, YBa_2Cu_3O_6 is an antiferromagnet with the magnetic moments lying on the Cu sites. Starting from this experimental result and the assumption, that nearest-neighbor Cu atoms within a layer have exactly antiparallel magnetic moments, the orientation of the magnetic moments has been determined within a nonadiabatic extension of the Heisenberg model of magnetism, called nonadiabatic Heisenberg model. Within this group-theoretical model there exist four stable magnetic structures in YBa_2Cu_3O_6, two of them are obviously identical with the high- and low-temperature structure established experimentally. However, not all the magnetic moments which appear to be antiparallel in neutron-scattering experiments are exactly antiparallel within this group-theoretical model. Furthermore, within this model the magnetic moments are not exactly perpendicular to the orthorhombic c axis.
Spontaneous generation of local CP violation and inverse magnetic catalysis
Lang Yu; Hao Liu; Mei Huang
2014-09-14T23:59:59.000Z
In the chiral symmetric phase, the polarized instanton--anti-instanton molecule pairing induces a nontrivial repulsive interaction in the iso-scalar axial-vector channel. As a consequence, one unusual property is observed that in the chiral restoration phase, there is a first order phase transition for the spontaneous generation of local CP violation and chiral imbalance. Furthermore, it is found that external magnetic fields will lower the critical temperature for the local CP-odd phase transition and catalyze the chiral imbalance, which destroys the chiral condensate with pairing quarks between different chiralities. A reasonable strength of the repulsive interaction in the iso-scalar axial-vector channel can naturally explain the inverse magnetic catalysis around the critical temperature under external magnetic fields.
N. V. Antonov; N. M. Gulitskiy
2015-01-21T23:59:59.000Z
Inertial-range asymptotic behavior of a vector (e.g., magnetic) field, passively advected by a strongly anisotropic turbulent flow, is studied by means of the field theoretic renormalization group and the operator product expansion. The advecting velocity field is Gaussian, not correlated in time, with the pair correlation function of the form $\\propto \\delta(t-t') / k_{\\bot}^{d-1+\\xi}$, where $k_{\\bot}=|{\\bf k}_{\\bot}|$ and ${\\bf k}_{\\bot}$ is the component of the wave vector, perpendicular to the distinguished direction (`direction of the flow') -- the $d$-dimensional generalization of the ensemble introduced by Avellaneda and Majda [{\\it Commun. Math. Phys.} {\\bf 131}: 381 (1990)]. The stochastic advection-diffusion equation for the transverse (divergence-free) vector field includes, as special cases, the kinematic dynamo model for magnetohydrodynamic turbulence and the linearized Navier--Stokes equation. In contrast to the well known isotropic Kraichnan's model, where various correlation functions exhibit anomalous scaling behavior with infinite sets of anomalous exponents, here the dependence on the integral turbulence scale $L$ has a logarithmic behavior: instead of power-like corrections to ordinary scaling, determined by naive (canonical) dimensions, the anomalies manifest themselves as polynomials of logarithms of $L$. The key point is that the matrices of scaling dimensions of the relevant families of composite operators appear nilpotent and cannot be diagonalized. The detailed proof of this fact is given for correlation functions of arbitrary order.
Vectorizing the Community Land Model (CLM)
Hoffman, Forrest M [ORNL; Vertenstein, Mariana [National Center for Atmospheric Research (NCAR); Kitabata, Hideyuki [Central Research Institute of Electric Power Industry, Japan; White III, James B [ORNL
2005-01-01T23:59:59.000Z
In this paper we describe our extensive efforts to rewrite the Community Land Model (CLM) so that it provides good vector performance on the Earth Simulator in Japan and the Cray X1 at Oak Ridge National Laboratory. We present the technical details of the old and new internal data structures, the required code reorganization, and the resulting performance improvements. We describe and compare the performance and scaling of the final CLM Version 3.0 (CLM3.0) on the IBM Power4, the Earth Simulator, and the Cray X1. At 64 processors, the performance of the model is similar on the IBM Power4, the Earth Simulator, and the Cray X1. However, the Cray X1 offers the best performance of all three platforms tested from 4 to 64 processors when OpenMP is used. Moreover, at low processor counts (16 or fewer), the model performs significantly better on the Cray X1 than on the other platforms. The vectorized version of CLM was publicly released by the National Center for Atmospheric Research as the standalone CLM3.0, as a part of the new Community Atmosphere Model Version 3.0 (CAM3.0), and as a component of the Community Climate System Model Version 3.0 (CCSM3.0) on June 23, 2004.
Light Vector Mesons in the Nuclear Medium
M. H. Wood; R. Nasseripour; D. P. Weygand; C. Djalali; C. Tur; U. Mosel; P. Muehlich; CLAS Collaboration
2008-03-04T23:59:59.000Z
The light vector mesons ($\\rho$, $\\omega$, and $\\phi$) were produced in deuterium, carbon, titanium, and iron targets in a search for possible in-medium modifications to the properties of the $\\rho$ meson at normal nuclear densities and zero temperature. The vector mesons were detected with the CEBAF Large Acceptance Spectrometer (CLAS) via their decays to $e^{+}e^{-}$. The rare leptonic decay was chosen to reduce final-state interactions. A combinatorial background was subtracted from the invariant mass spectra using a well-established event-mixing technique. The $\\rho$ meson mass spectrum was extracted after the $\\omega$ and $\\phi$ signals were removed in a nearly model-independent way. Comparisons were made between the $\\rho$ mass spectra from the heavy targets ($A > 2$) with the mass spectrum extracted from the deuterium target. With respect to the $\\rho$-meson mass, we obtain a small shift compatible with zero. Also, we measure widths consistent with standard nuclear many-body effects such as collisional broadening and Fermi motion.
Masaaki Yamada, Russell Kulsrud and Hantao Ji
2009-09-17T23:59:59.000Z
We review the fundamental physics of magnetic reconnection in laboratory and space plasmas, by discussing results from theory, numerical simulations, observations from space satellites, and the recent results from laboratory plasma experiments. After a brief review of the well-known early work, we discuss representative recent experimental and theoretical work and attempt to interpret the essence of significant modern findings. In the area of local reconnection physics, many significant findings have been made with regard to two- uid physics and are related to the cause of fast reconnection. Profiles of the neutral sheet, Hall currents, and the effects of guide field, collisions, and micro-turbulence are discussed to understand the fundamental processes in a local reconnection layer both in space and laboratory plasmas. While the understanding of the global reconnection dynamics is less developed, notable findings have been made on this issue through detailed documentation of magnetic self-organization phenomena in fusion plasmas. Application of magnetic reconnection physics to astrophysical plasmas is also brie y discussed.
Ringberg 2003 Vector Mesons Paul Thompson 1 Paul Thompson
Ringberg 2003 Vector Mesons Paul Thompson 1 Paul Thompson B i r mi ng ham U ni v e r si t y S ummar y H 1 and Z E U S C ollab or at i ons #12;Ringberg 2003 Vector Mesons Paul Thompson 2 Motivation s s e s #12;Ringberg 2003 Vector Mesons Paul Thompson 3 Â§ Experimentally clean process Â§ w id e k
Patterned Magnetic Nanostructures and Quantized Magnetic Disks
-increasing demands in data storage and to new applications of magnetic devices in the field of sensors. NewPatterned Magnetic Nanostructures and Quantized Magnetic Disks STEPHEN Y. CHOU Invited Paper, opens up new opportunities for engineering innovative magnetic materials and devices, developing ultra
Origin of Low-Lying Enhanced E1 Strength in Rare-Earth Nuclei
Spieker, M; Zilges, A; Iachello, F
2015-01-01T23:59:59.000Z
The experimental $E1$ strength distribution below 4 MeV in rare-earth nuclei suggests a local breaking of isospin symmetry. In addition to the octupole states, additional $1^-$ states with enhanced E1 strength have been observed in rare-earth nuclei by means of ($\\gamma,\\gamma'$) experiments. By reproducing the experimental results, the spdf interacting boson model calculations provide further evidence for the formation of an $\\alpha$ cluster in medium-mass nuclei and might provide a new understanding of the origin of low-lying E1 strength.
Origin of Low-Lying Enhanced E1 Strength in Rare-Earth Nuclei
M. Spieker; S. Pascu; A. Zilges; F. Iachello
2015-05-17T23:59:59.000Z
The experimental $E1$ strength distribution below 4 MeV in rare-earth nuclei suggests a local breaking of isospin symmetry. In addition to the octupole states, additional $1^-$ states with enhanced E1 strength have been observed in rare-earth nuclei by means of ($\\gamma,\\gamma'$) experiments. By reproducing the experimental results, the spdf interacting boson model calculations provide further evidence for the formation of an $\\alpha$ cluster in medium-mass nuclei and might provide a new understanding of the origin of low-lying E1 strength.
Multi-group Support Vector Machines with measurement costs
Emilio Carrizosa
2006-05-11T23:59:59.000Z
May 11, 2006 ... Multi-group Support Vector Machines with measurement costs: a biobjective approach. Emilio Carrizosa (ecarrizosa ***at*** us.es)
Hybrid MPI/OpenMP parallel support vector machine training
Kristian Woodsend
2009-01-12T23:59:59.000Z
Jan 12, 2009 ... A parallel implementation of Support Vector Machine training has been developed, using a combination of MPI and OpenMP. Using an interior ...
adenovirus vector transfer: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
system with regard to the current reconstructed vector. Here we extend TERV for multivariate time series, and account for the presence of confounding variables, called partial...
Vector Network Analyzer Techniques to measure WR340 Waveguide...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
6 Vector Network Analyzer Techniques to Measure WR340 Waveguide Windows T. L. Smith ASD RF Group Advanced Photon Source Argonne National Laboratory June 26, 2002 Table of...
Development Of Active Seismic Vector-Wavefield Imaging Technology...
LibraryAdd to library Report: Development Of Active Seismic Vector-Wavefield Imaging Technology For Geothermal Applications Abstract This report describes the development and...
An optimized magnet for magnetic refrigeration
Bjørk, R; Smith, A; Christensen, D V; Pryds, N
2014-01-01T23:59:59.000Z
A magnet designed for use in a magnetic refrigeration device is presented. The magnet is designed by applying two general schemes for improving a magnet design to a concentric Halbach cylinder magnet design and dimensioning and segmenting this design in an optimum way followed by the construction of the actual magnet. The final design generates a peak value of 1.24 T, an average flux density of 0.9 T in a volume of 2 L using only 7.3 L of magnet, and has an average low flux density of 0.08 T also in a 2 L volume. The working point of all the permanent magnet blocks in the design is very close to the maximum energy density. The final design is characterized in terms of a performance parameter, and it is shown that it is one of the best performing magnet designs published for magnetic refrigeration.
GROUPES DE LIE COMPACTS ET LEURS REPRESENTATIONS Examen du 18 janvier 2008, 14h 17h30
Wurzbacher, Tilmann
que pour G comme ci-dessus et X = A E = TeG on a pour tout g dans G, XL (g) = g·A E = TgG. (I·X·g-1 pour tout X dans E = TeG. (I.i) Soit f : K M un homomorphisme de groupes de Lie. Montrer que exp un homomorphisme de groupes de Lie. Posons ad = Ade . Montrer que X, Y E = TeG, ad(X)(Y ) = [X, Y ]E
Vector analyzing power of {pi}{sup +7}Li scattering in the region of the {delta}{sub 33} resonance
Ibraeva, E. T. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Zhusupov, M. A. [Kazakh State University, Institute of Experimental and Theoretical Physics (Kazakhstan); Zaykin, A. Yu. [National Nuclear Center of the Republic of Kazakhstan, Institute of Nuclear Physics (Kazakhstan); Imambekov, O. [Kazakh State University, Institute of Experimental and Theoretical Physics (Kazakhstan)
2006-04-15T23:59:59.000Z
Within Glauber diffraction theory, the vector analyzing power iT{sub 11} is calculated at three energies of positively charged pions, 134, 164, and 194 MeV, incident to {sup 7}Li nuclei. These energy values lie in the region of the {delta}{sub 33} resonance in {pi}{sup {+-}}N interaction, the resonance maximum being at 180 MeV. The calculation of iT{sub 11} was performed with several model {sup 7}Li wave functions, including the {alpha}t-cluster and shell-model ones. The properties of {pi}{sup +7}Li scattering are found to be sensitive to the structural features of the target nucleus. A comparison of the results of the calculations with experimental data shows that the wave functions in question and the potentials used to calculate them are quite appropriate.
Thermal neutron diffraction determination of the magnetic structure of EuCu{sub 2}Ge{sub 2}
Rowan-Weetaluktuk, W. N.; Ryan, D. H., E-mail: dhryan@physics.mcgill.ca [Department of Physics, and Centre for the Physics of Materials, McGill University, 3600 University Street, Montreal, Quebec H3A 2T8 (Canada); Lemoine, P. [Laboratoire CRISMAT, ENSICAEN, UMR 6508 CNRS, 6 Boulevard du Maréchal Juin, 14050 Caen Cedex 4 (France); Cadogan, J. M. [School of Physical, Environmental and Mathematical Sciences, UNSW Canberra at the Australian Defence Force Academy, Canberra BC 2610 (Australia)
2014-05-07T23:59:59.000Z
The magnetic structure of EuCu{sub 2}Ge{sub 2} has been determined by flat-plate neutron powder diffraction. Two magnetic phases are present in the neutron diffraction pattern at 3.5?K. They have the same moment, within error, and a common transition temperature. Both {sup 151}Eu and {sup 153}Eu Mössbauer spectroscopy show that the two magnetic phases belong to the same crystallographic phase. Both phases can be modelled by planar helimagnetic structures: one with a propagation vector of [0.654(1), 0, 0], the other with a propagation vector of [0.410(1), 0.225(1), 0].
Local momentum space and the vector field
David J. Toms
2014-08-04T23:59:59.000Z
The local momentum space expansion for the real vector field is considered. Using Riemann normal coordinates we obtain an expansion of the Feynman Green function up and including terms that are quadratic in the curvature. The results are valid for a non-minimal operator such as that arising from a general Feynman type gauge fixing condition. The result is used to derive the first three terms in the asymptotic expansion for the coincidence limit of the heat kernel without taking the trace, thus obtaining the untraced heat kernel coefficients. The spacetime dimension is kept general before specializing to four dimensions for comparison with previously known results. As a further application we re-examine the anomalous trace of the stress-energy-momentum tensor for the Maxwell field and comment on the gauge dependence.
CMB non-gaussianity from vector fields
Peloso, Marco [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)
2014-06-24T23:59:59.000Z
The Planck satellite has recently measured the CMB temperature anisotropies with unprecedented accuracy, and it has provided strong bounds on primordial non-gaussianity. Such bounds constrain models of inflation, and mechanisms that produce the primordial perturbations. We discuss the non-gaussian signatures from the interactions of the inflation ? with spin-1 fields. We study the two different cases in which the inflaton is (i) a pseudo-scalar field with a (?)/(fa) F·F interaction with a vector field, and (ii) a scalar field with a f (?)F{sup 2} interaction. In the first case we obtain the strong limit f{sub a} ? 10{sup 16}GeV on the decay constant. In the second case, specific choices of the function f (?) can lead to a non-gaussianity with a characteristic shape not encountered in standard models of scalar field inflation, and which has also been constrained by Planck.
Sweeney, George Franklin; Sweeney, George Franklin
2012-01-01T23:59:59.000Z
75 CSP #1: A vector in R 2 is defined as a space. . 78 CSP #2: stretched. . 89 CSP # 3: Setting up
Superconducting Magnet Division
Gupta, Ramesh
Superconducting Magnet Division Permanent Magnet Designs with Large Variations in Field Strength the residual field of the magnetized bricks by concentrating flux lines at the iron pole. Low Field Design Medium Field Design Superconducting Magnet Division Dipole and Quadrupole Magnets for RHIC e
The toric h-vectors of partially ordered sets
Bayer, Margaret M.; Ehrenborg, R.
2000-01-01T23:59:59.000Z
An explicit formula for the toric h-vector of an Eulerian poset in terms of the cd-index is developed using coalgebra techniques. The same techniques produce a formula in terms of the ag h-vector. For this, another proof based on Fine's algorithm...
A Note on Platt's Probabilistic Outputs for Support Vector Machines
Abu-Mostafa, Yaser S.
A Note on Platt's Probabilistic Outputs for Support Vector Machines Hsuan-Tien Lin (htlin, National Chengchi University, Taipei 116, Taiwan Abstract. Platt's probabilistic outputs for Support Vector Machines (Platt, 2000) has been popular for applications that require posterior class probabilities
Vector dark domain wall solitons in a fiber ring laser
H. Zhang; D. Y. Tang; L. M. Zhao; R. J. Knize
2009-10-15T23:59:59.000Z
We observe a novel type of vector dark soliton in a fiber ring laser. The vector dark soliton consists of stable localized structures separating the two orthogonal linear polarization eigenstates of the laser emission and is visible only when the total laser emission is measured. Moreover, polarization domain splitting and moving polarization domain walls (PDWs) were also experimentally observed.
ICMP: an Attack Vector against IPsec Gateways Ludovic Jacquin
Paris-Sud XI, UniversitÃ© de
ICMP: an Attack Vector against IPsec Gateways Ludovic Jacquin Inria, France ludovic Protocol (ICMP) can be used as an attack vector against IPsec gateways. The main contribution of this work is to demonstrate that an attacker having eavesdropping and traffic injection capabilities in the black untrusted
Laterotactile Rendering of Vector Graphics with the Stroke Pattern
Hayward, Vincent
Laterotactile Rendering of Vector Graphics with the Stroke Pattern Vincent LÃ©vesque1 and Vincent are used extensively in the design of tactile graphics for persons with visual impairments. A tactile is demonstrated with the rendering of lines, circles and polygons, and is extensible to other vector graphics
Iterative Water-filling for Gaussian Vector Multiple Access Channels
Li, Tiffany Jing
Iterative Water-filling for Gaussian Vector Multiple Access Channels W. Yu, W. Rhee, S. Boyd, and J. Cioffi Zhenlei Shen Lehigh University March 29, 2005 Zhenlei Shen (Lehigh) Iterative Water-filling for Gaussian Vector Multiple Access ChannelsMarch 29, 2005 1 / 13 #12;1 Quick Review 2 Iterative Water
Support Vector Learning for Fuzzy Rule-Based Classification Systems
Chen, Yixin
. As a powerful machine learning approach for pattern recognition problems, support vector machine (SVM) is known1 Support Vector Learning for Fuzzy Rule-Based Classification Systems Yixin Chen, Student Member DRAFT #12;2 Abstract To design a fuzzy rule-based classification system (fuzzy classifier) with good
Satti, John A. (Naperville, IL)
1980-01-01T23:59:59.000Z
A superconducting magnet designed to produce magnetic flux densities of the order of 4 to 5 Webers per square meter is constructed by first forming a cable of a plurality of matrixed superconductor wires with each wire of the plurality insulated from each other one. The cable is shaped into a rectangular cross-section and is wound with tape in an open spiral to create cooling channels. Coils are wound in a calculated pattern in saddle shapes to produce desired fields, such as dipoles, quadrupoles, and the like. Wedges are inserted between adjacent cables as needed to maintain substantially radial placement of the long dimensions of cross sections of the cables. After winding, individual strands in each of the cables are brought out to terminals and are interconnected to place all of the strands in series and to maximize the propagation of a quench by alternating conduction from an inner layer to an outer layer and from top half to bottom half as often as possible. Individual layers are separated from others by spiraled aluminum spacers to facilitate cooling. The wound coil is wrapped with an epoxy tape that is cured by heat and then machined to an interference fit with an outer aluminum pipe which is then affixed securely to the assembled coil by heating it to make a shrink fit. In an alternate embodiment, one wire of the cable is made of copper or the like to be heated externally to propagate a quench.
Video-rate terahertz electric-field vector imaging
Takai, Mayuko; Takeda, Masatoshi; Sasaki, Manabu; Tachizaki, Takehiro; Yasumatsu, Naoya; Watanabe, Shinichi, E-mail: watanabe@phys.keio.ac.jp [Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522 (Japan)
2014-10-13T23:59:59.000Z
We present an experimental setup to dramatically reduce a measurement time for obtaining spatial distributions of terahertz electric-field (E-field) vectors. The method utilizes the electro-optic sampling, and we use a charge-coupled device to detect a spatial distribution of the probe beam polarization rotation by the E-field-induced Pockels effect in a ?110?-oriented ZnTe crystal. A quick rotation of the ZnTe crystal allows analyzing the terahertz E-field direction at each image position, and the terahertz E-field vector mapping at a fixed position of an optical delay line is achieved within 21 ms. Video-rate mapping of terahertz E-field vectors is likely to be useful for achieving real-time sensing of terahertz vector beams, vector vortices, and surface topography. The method is also useful for a fast polarization analysis of terahertz beams.
Iso-vector form factors of the delta and nucleon in QCD sum rules
Ozpineci, A. [Physics Department, Middle East Technical University, 06800 (Turkey)
2012-10-23T23:59:59.000Z
Form factors are important non-perturbative properties of hadrons. They give information about the internal structure of the hadrons. In this work, iso-vector axial-vector and iso-vector tensor form factors of the nucleon and the iso-vector axial-vector {Delta}{yields}N transition form factor calculations in QCD Sum Rules are presented.
Nanostructured magnetic materials
Chan, Keith T.
2011-01-01T23:59:59.000Z
Magnetism and Magnetic Materials Conference, Atlanta, GA (Nanostructured Magnetic Materials by Keith T. Chan Doctor ofinduced by a Si-based material occurs at a Si/Ni interface
Interface Magnetism in Multiferroics
He, Qing
2011-01-01T23:59:59.000Z
1.2.1 Magnetism . . . . . . . . . . . . . . . . . . . 1.2.2domain walls . . . . . 3 Magnetism of domain walls in BiFeOof electrical control of magnetism in mixed phase BiFeO 3
Laced permanent magnet quadrupole drift tube magnets
Feinberg, B.; Behrsing, G.U.; Halbach, K.; Marks, J.S.; Morrison, M.E.; Nelson, D.H.
1989-03-01T23:59:59.000Z
Twenty-three laced permanent magnet quadrupole drift tube magnets have been constructed, tested, and installed in the SuperHILAC heavy ion linear accelerator at LBL, marking the first accelerator use of this new type of quadrupole. The magnets consist of conventional tape-wound quadrupole electromagnets, using iron pole-pieces, with permanent magnet material (samarium cobalt) inserted between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the individual quadrupole magnets in a drift tube linac is never reversed, we can take advantage of this asymmetrical saturation to provide about 20% greater focusing strength than is available with conventional quadrupoles, while replacing the vanadium permendur poletips with iron poletips. Comparisons between these magnets and conventional tape-wound quadrupoles will be presented. 3 refs., 5 figs.
Animalu, A.O.E.
1987-11-01T23:59:59.000Z
A new approach to the ''extended relativity'' principle proposed by Recami, Mignani, and others, in which the speed of light (c) is invariant with respect to both subluminal (v
Yuya Sasai; Naoki Sasakura
2009-05-13T23:59:59.000Z
We investigate the unitarity of three dimensional noncommutative scalar field theory in the Lie algebraic noncommutative spacetime [x^i,x^j]=2i kappa epsilon^{ijk}x_k. This noncommutative field theory possesses a SL(2,R)/Z_2 group momentum space, which leads to a Hopf algebraic translational symmetry. We check the Cutkosky rule of the one-loop self-energy diagrams in the noncommutative phi^3 theory when we include a braiding, which is necessary for the noncommutative field theory to possess the Hopf algebraic translational symmetry at quantum level. Then, we find that the Cutkosky rule is satisfied if the mass is less than 1/(2^(1/2)kappa).
T. Sumikama; K. Matsuta; T. Nagatomo; M. Ogura; T. Iwakoshi; Y. Nakashima; H. Fujiwara; M. Fukuda; M. Mihara; K. Minamisono; T. Yamaguchi; T. Minamisono
2011-05-09T23:59:59.000Z
The beta-ray angular correlations for the spin alignments of 8Li and 8B have been observed in order to test the conserved vector current (CVC) hypothesis. The alignment correlation terms were combined with the known beta-alpha-angular correlation terms to determine all the matrix elements contributing to the correlation terms. The weak magnetism term, 7.5\\pm0.2, deduced from the beta-ray correlation terms was consistent with the CVC prediction 7.3\\pm0.2, deduced from the analog-gamma-decay measurement based on the CVC hypothesis. However, there was no consistent CVC prediction for the second-forbidden term associated with the weak vector current. The experimental value for the second-forbidden term was 1.0 \\pm 0.3, while the CVC prediction was 0.1 \\pm 0.4 or 2.1 \\pm 0.5.
Lie-Santilli isoapproach to the unification of gravity and electromagnetism
Animalu, A.O.E. [Univ. of Nigeria, Nsukka (Nigeria)]|[Istituto per la Ricerca di Base, Monteroduni (Italy)
1996-06-01T23:59:59.000Z
The author reviews the problem of Einstein`s original proposal for the unification of gravity and electromagnetism in space-time differential geometry along the lines of the recent contributions by A.A. Logunov, R.M. Santilli, D.F. Lopez and others. The author presents a new method of unification based on the Lie-Santilli isotopic theory whereby the unified field tensor g = (g{sub {mu}{nu}}) is constructed from the symmetric Riemannian gravitational tensor, g = (g{mu}{nu}), and the antisymmetric electromagnetic field tensor F = (F{sub {mu}{nu}}) via an isotopic lifting g {yields} {cflx g} = Fg of the type of Lax pairing, where det F {ne} 0, the unified field {cflx g} satisfies Logunov-Santilli equations while g and F are treated as Lax pair. Because of Santilli`s isotopic equivalence between Minkowskian and Riemannian geometries, the author infers that in the Minkowskian limit F = f, g = {eta}, the metric {eta} satisfies Lax`s equation of motion {partial_derivative}{eta}/{partial_derivative}t = f{eta} {minus} {eta}f which insures the conservation of the eigenvalues of g. The invariance of the electromagnetic group of transformations (F) in Minkowski space is determined by the eigenvalue equations, det (F{sub {mu}{nu}}){minus}{lambda}{eta}{sub {mu}{nu}} = 0, from which the author deduces a Lie-isotopic {open_quotes}extended{close_quotes} relativity principle. A wave equation for a spin-2 particle in the unified field is derived, and the experimental consequences of the theory are discussed.
SUPERCONDUCTING MAGNETIC ENERGY STORAGE
Hassenzahl, W.
2011-01-01T23:59:59.000Z
Superconducting 30-MJ Energy Storage Coil", Proc. 19 80 ASC,Superconducting Magnetic Energy Storage Plant", IEEE Trans.SlIperconducting Magnetic Energy Storage Unit", in Advances
SUPERCONDUCTING MAGNETIC ENERGY STORAGE
Hassenzahl, W.
2011-01-01T23:59:59.000Z
Design of the BPA Superconducting 30-MJ Energy Storagefor a Utility Scale Superconducting Magnetic Energy Storagefor a Lnrge Scale Superconducting Magnetic Energy Storage
Statistical performance of support vector machines
Blanchard, Gilles; Massart, Pascal
2008-01-01T23:59:59.000Z
The support vector machine (SVM) algorithm is well known to the computer learning community for its very good practical results. The goal of the present paper is to study this algorithm from a statistical perspective, using tools of concentration theory and empirical processes. Our main result builds on the observation made by other authors that the SVM can be viewed as a statistical regularization procedure. From this point of view, it can also be interpreted as a model selection principle using a penalized criterion. It is then possible to adapt general methods related to model selection in this framework to study two important points: (1) what is the minimum penalty and how does it compare to the penalty actually used in the SVM algorithm; (2) is it possible to obtain ``oracle inequalities'' in that setting, for the specific loss function used in the SVM algorithm? We show that the answer to the latter question is positive and provides relevant insight to the former. Our result shows that it is possible to...
$D^+ \\to K^- ?^+ ?^+$ - the weak vector current
P. C. Magalhães; M. R. Robilotta
2015-04-23T23:59:59.000Z
Studies of D and B mesons decays into hadrons have been used to test the standard model in the last fifteen years. A heavy meson decay involves the combined effects of a primary weak vertex and subsequent hadronic final state interactions, which determine the shapes of Dalitz plots. The fact that final products involve light mesons indicates that the QCD vacuum is an active part of the problem. This makes the description of these processes rather involved and, in spite of its importance, phenomenological analyses tend to rely on crude models. Our group produced, some time ago, a schematic calculation of the decay $D^+ \\to K^- \\pi^+ \\pi^+$, which provided a reasonable description of data. Its main assumption was the dominance of the weak vector-current, which yields a non-factorizable interaction. Here we refine that calculation by including the correct momentum dependence of the weak vertex and extending the energy ranges of $\\pi\\pi$ and $K\\pi$ subamplitudes present into the problem. These new features make the present treatment more realistic and bring theory closer to data.
Quantum dynamics of a particle constrained to lie on a surface
Gustavo de Oliveira
2014-09-04T23:59:59.000Z
We consider the quantum dynamics of a charged particle in Euclidean space subjected to electric and magnetic fields under the presence of a potential that forces the particle to stay close to a compact surface. We prove that, as the strength of this constraining potential tends to infinity, the motion of this particle converges to a motion generated by a Hamiltonian over the surface superimposed by an oscillatory motion in the normal directions. Our result extend previous results by allowing magnetic potentials and more general constraining potentials.
Vermont, University of
MODELING/GIS, RISK ASSESSMENT, ECONOMIC IMPACT Household Model of Chagas Disease Vectors (Hemiptera vectors (Hemiptera: Reduviidae) of the causative parasite Trypanosoma cruzi (Kinetoplastida bitten by infected insect vectors. There are 130 species in the subfamily Triatominae (Hemiptera
Magnetic polarizabilities of light mesons in $SU(3)$ lattice gauge theory
E. V. Luschevskaya; O. E. Solovjeva; O. A. Kochetkov; O. V. Teryaev
2015-02-27T23:59:59.000Z
We investigate the masses (ground state energies) of neutral pseudoscalar and vector meson in $SU(3)$ lattice gauge theory in strong abelian magnetic field. The energy of $\\rho^0$ meson with zero spin projection $s_z=0$ on the axis of the external magnetic field decreases, while the energies with non-zero spins $s_z=-1$ and $+1$ increase with the field. The energy of $\\pi^0$ meson decrease as a function of the magnetic field. We calculated the magnetic polarizabilities of pseudoscalar and vector mesons for lattice volume $18^4$. For $\\rho^0$ with spin $|s_z|=1$ and $\\pi^0$ meson the extrapolations to zero lattice spacing have been done. We do not observe any evidence in favour of tachyonic mode existence.
Magnetic polarizabilities of light mesons in $SU(3)$ lattice gauge theory
E. V. Luschevskaya; O. E. Solovjeva; O. A. Kochetkov; O. V. Teryaev
2015-02-17T23:59:59.000Z
We investigate the masses (ground state energies) of neutral pseudoscalar and vector meson in $SU(3)$ lattice gauge theory in strong abelian magnetic field. The energy of $\\rho^0$ meson with zero spin projection $s_z=0$ on the axis of the external magnetic field decreases, while the energies with non-zero spins $s_z=-1$ and $+1$ increase with the field. The energy of $\\pi^0$ meson decrease as a function of the magnetic field. We calculated the magnetic polarizabilities of pseudoscalar and vector mesons for lattice volume $18^4$. For $\\rho^0$ with spin $|s_z|=1$ and $\\pi^0$ meson the extrapolations to zero lattice spacing have been done. We do not observe any evidence in favour of tachyonic mode existence.
Optimization code with weighting function for the reconstruction of coronal magnetic fields
T. Wiegelmann
2008-02-01T23:59:59.000Z
We developed a code for the reconstruction of nonlinear force-free and non-force-free coronal magnetic fields. The 3D magnetic field is computed numerically with the help of an optimization principle. The force-free and non-force-free codes are compiled in one program. The force-free approach needs photospheric vector magnetograms as input. The non-force-free code additionally requires the line-of-sight integrated coronal density distribution in combination with a tomographic inversion code. Previously the optimization approach has been used to compute magnetic fields using all six boundaries of a computational box. Here we extend this method and show how the coronal magnetic field can be reconstructed only from the bottom boundary, where the boundary conditions are measured with vector magnetographs. The program is planed for use within the Stereo mission.
A MATHEMATICAL MODEL FOR AN HOURGLASS MAGNETIC FIELD
Ewertowski, Bartek; Basu, Shantanu, E-mail: basu@uwo.ca [Department of Physics and Astronomy, Western University, London, Ontario N6A 3K7 (Canada)] [Department of Physics and Astronomy, Western University, London, Ontario N6A 3K7 (Canada)
2013-04-10T23:59:59.000Z
Starting with a mathematical boundary value problem for the magnetic vector potential in an axisymmetric cylindrical coordinate system, we derive a general solution for any arbitrary current distribution using the method of Green's functions. We use this to derive an analytic form for an hourglass magnetic field pattern created by electrical currents that are concentrated near (but not confined within) the equatorial plane of a cylindrical coordinate system. Our solution is not characterized by a cusp at the equatorial plane, as in previous solutions based on a current sheet. The pattern we derive provides a very good fit to hourglass magnetic field patterns emerging from three-dimensional numerical simulations of core formation, and can in principle be used for source-fitting of observed magnetic hourglass patterns.
Configuration and temperature dependence of magnetic damping in spin valves
Joyeux, X.; Devolder, T.; Kim, Joo-Von; Gomez de la Torre, Y.; Eimer, S.; Chappert, C. [Institut d'Electronique Fondamentale, University Paris-Sud, 91405 Orsay (France); UMR8622, CNRS, University Paris-Sud, 91405 Orsay (France)
2011-09-15T23:59:59.000Z
Using vector-analyzer ferromagnetic resonance, we have studied the microwave susceptibility of a Py/Co/Cu/Co/MnIr spin valve over a large temperature range (5-450 K) and as a function of the magnetic configuration. An effective magnetization and Gilbert damping constant of 1.1 T and 0.021, respectively, are found for the permalloy free layer, with no discernible variation in temperature observed for either quantities. In contrast, the pinned layer magnetization is reduced by heating, and the exchange bias collapses near a temperature of 450 K. The ferromagnetic resonance linewidth of the free layer increases by 500 MHz when the layer magnetizations are aligned in antiparallel, which is attributed to a configuration-dependent contribution to the damping from spin pumping effects.
Dynamics of molecular superrotors in external magnetic field
Korobenko, Aleksey
2015-01-01T23:59:59.000Z
We excite diatomic oxygen and nitrogen to high rotational states with an optical centrifuge and study their dynamics in external magnetic field. Ion imaging is employed to directly visualize, and follow in time, the rotation plane of molecular superrotors. The two different mechanisms of interaction between the magnetic field and the molecular angular momentum in paramagnetic oxygen and non-magnetic nitrogen lead to the qualitatively different behaviour. In nitrogen, we observe the precession of the molecular angular momentum around the field vector. In oxygen, strong spin-rotation coupling results in faster and richer dynamics, encompassing the splitting of the rotation plane in three separate components. As the centrifuged molecules evolve with no significant dispersion of the molecular wave function, the observed magnetic interaction presents an efficient mechanism for controlling the plane of molecular rotation.
Nonlinear force-free modeling of the solar coronal magnetic field
T. Wiegelmann
2008-01-18T23:59:59.000Z
The coronal magnetic field is an important quantity because the magnetic field dominates the structure of the solar corona. Unfortunately direct measurements of coronal magnetic fields are usually not available. The photospheric magnetic field is measured routinely with vector magnetographs. These photospheric measurements are extrapolated into the solar corona. The extrapolated coronal magnetic field depends on assumptions regarding the coronal plasma, e.g. force-freeness. Force-free means that all non-magnetic forces like pressure gradients and gravity are neglected. This approach is well justified in the solar corona due to the low plasma beta. One has to take care, however, about ambiguities, noise and non-magnetic forces in the photosphere, where the magnetic field vector is measured. Here we review different numerical methods for a nonlinear force-free coronal magnetic field extrapolation: Grad-Rubin codes, upward integration method, MHD-relaxation, optimization and the boundary element approach. We briefly discuss the main features of the different methods and concentrate mainly on recently developed new codes.
MAGNETIC FIELD IN THE ISOLATED MASSIVE DENSE CLUMP IRAS 20126+4104
Shinnaga, Hiroko; Phillips, Thomas G. [California Institute of Technology Submillimeter Observatory, 111 Nowelo Street, Hilo, HI 96720 (United States); Novak, Giles [Department of Physics and Astronomy, Northwestern University, 633 Clark Street Evanston, IL 60208 (United States); Vaillancourt, John E. [Stratospheric Observatory for Infrared Astronomy, Universities Space Research Association, NASA Ames Research Center, Moffet Field, CA 94035 (United States); Machida, Masahiro N. [Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Kataoka, Akimasa [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Tomisaka, Kohji [National Astronomical Observatory of Japan and Department of Astronomy, School of Physical Sciences, Graduate University for Advanced Studies (SOKENDAI), Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan); Davidson, Jacqueline; Houde, Martin [School of Physics, University of Western Australia, 35 Stirling Highway, Crawley WA 6009, Perth (Australia); Dowell, C. Darren [Jet Propulsion Laboratory, California Institute of Technology, MS 169-506, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Leeuw, Lerothodi [SETI Institute, 515 North Whisman Avenue, Mountain View, CA 94043 (United States)
2012-05-10T23:59:59.000Z
We measured polarized dust emission at 350 {mu}m toward the high-mass star-forming massive dense clump IRAS 20126+4104 using the SHARC II Polarimeter, SHARP, at the Caltech Submillimeter Observatory. Most of the observed magnetic field vectors agree well with magnetic field vectors obtained from a numerical simulation for the case when the global magnetic field lines are inclined with respect to the rotation axis of the dense clump. The results of the numerical simulation show that rotation plays an important role on the evolution of the massive dense clump and its magnetic field. The direction of the cold CO 1-0 bipolar outflow is parallel to the observed magnetic field within the dense clump as well as the global magnetic field, as inferred from optical polarimetry data, indicating that the magnetic field also plays a critical role in an early stage of massive star formation. The large-scale Keplerian disk of the massive (proto)star rotates in an almost opposite sense to the clump's envelope. The observed magnetic field morphology and the counterrotating feature of the massive dense clump system provide hints to constrain the role of magnetic fields in the process of high-mass star formation.
Energy momentum flows for the massive vector field
George Horton; Chris Dewdney
2006-09-26T23:59:59.000Z
We present a causal trajectory interpretation for the massive vector field, based on the flows of rest energy and a conserved density defined using the time-like eigenvectors and eigenvalues of the stress-energy-momentum tensor. This work extends our previous work which used a similar procedure for the scalar field. The massive, spin-one, complex vector field is discussed in detail and solutions are classified using the Pauli-Lubanski spin vector. The flows of energy-momentum are illustrated in a simple example of standing waves in a plane.
Characterizing cluster morphology using vector-valued Minkowski functionals
Claus Beisbart; Thomas Buchert
1997-11-04T23:59:59.000Z
The morphology of galaxy clusters is quantified using Minkowski functionals, especially the vector-valued ones, which contain directional information and are related to curvature centroids. The asymmetry of clusters and the amount of their substructure can be characterized in a unique way using these measures. -- We briefly introduce vector-valued Minkowski functionals (also known as Querma\\ss vectors) and suggest their application to cluster data in terms of a morphological characterization of excursion sets. Furthermore, we develop robust structure functions which describe the dynamical state of a cluster and study the evolution of clusters using numerical simulations.
The Vacuum Structure of Vector Mesons in QCD
Rennecke, Fabian
2015-01-01T23:59:59.000Z
We study the chiral dynamics of vector mesons in two-flavor QCD in vacuum by utilizing a functional renormalization group approach. This allows us to capture the dynamical transition from the quark-gluon phase at high energies to the hadronic phase at low energies without the necessity of model parameter tuning. We use this to analyze the scaling of vector meson masses towards the chiral symmetry breaking scale, the decoupling of the mesons at high energies and the validity of vector meson dominance.
Adiabatic expansion and magnetic fields in AGN jets
A. B. Pushkarev; Y. Y. Kovalev; A. P. Lobanov
2008-12-25T23:59:59.000Z
Results of high-resolution simultaneous multi-frequency 8.1-15.4 GHz VLBA polarimetric observations of relativistic jets in active galactic nuclei (the MOJAVE-2 project) are analyzed. We compare characteristics of VLBI features with jet model predictions and test if adiabatic expansion is a dominating mechanism for the evolution of relativistic shocks in parsec-scale AGN jets. We also discuss magnetic field configuration, both predicted by the model and deduced from electric vector position angle measurements.
Magnetic Phase Transitions in NdCoAsO
McGuire, Michael A [ORNL; Gout, Delphine J [ORNL; Garlea, Vasile O [ORNL; Sefat, A. S. [Oak Ridge National Laboratory (ORNL); Sales, Brian C [ORNL; Mandrus, David [ORNL
2010-01-01T23:59:59.000Z
NdCoAsO undergoes three magnetic phase transitions below room temperature. Here we report the results of our experimental investigation of this compound, including determination of the crystal and magnetic structures using powder neutron diffraction, as well as measurements of electrical resistivity, thermal conductivity, Seebeck coefficient, magnetization, and heat capacity. These results show that upon cooling a ferromagnetic state emerges near 69 K with a small saturation moment of -0.2{micro}{sub B}, likely on Co atoms. At 14 K the material enters an antiferromagnetic state with propagation vector (0 0 1/2) and small ordered moments (-0.4{micro}{sub B}) on Co and Nd. Near 3.5 K a third transition is observed, and corresponds to the antiferromagnetic ordering of larger moments on Nd, with the same propagation vector. The ordered moment on Nd reaches 1.39(5){micro}{sub B} at 300 mK. Anomalies in the magnetization, electrical resistivity, and heat capacity are observed at all three magnetic phase transitions.
3D reconstruction of tensors and vectors
Defrise, Michel; Gullberg, Grant T.
2005-02-17T23:59:59.000Z
Here we have developed formulations for the reconstruction of 3D tensor fields from planar (Radon) and line-integral (X-ray) projections of 3D vector and tensor fields. Much of the motivation for this work is the potential application of MRI to perform diffusion tensor tomography. The goal is to develop a theory for the reconstruction of both Radon planar and X-ray or line-integral projections because of the flexibility of MRI to obtain both of these type of projections in 3D. The development presented here for the linear tensor tomography problem provides insight into the structure of the nonlinear MRI diffusion tensor inverse problem. A particular application of tensor imaging in MRI is the potential application of cardiac diffusion tensor tomography for determining in vivo cardiac fiber structure. One difficulty in the cardiac application is the motion of the heart. This presents a need for developing future theory for tensor tomography in a motion field. This means developing a better understanding of the MRI signal for diffusion processes in a deforming media. The techniques developed may allow the application of MRI tensor tomography for the study of structure of fiber tracts in the brain, atherosclerotic plaque, and spine in addition to fiber structure in the heart. However, the relations presented are also applicable to other fields in medical imaging such as diffraction tomography using ultrasound. The mathematics presented can also be extended to exponential Radon transform of tensor fields and to other geometric acquisitions such as cone beam tomography of tensor fields.
Laced permanent magnet quadrupole drift tube magnets
Feinberg, B.; Behrsing, G.U.; Halbach, K.; Marks, J.S.; Morrison, M.E.; Nelson, D.H.
1988-10-01T23:59:59.000Z
A laced permanent magnet quadrupole drift tube magnet has been constructed for a proof-of-principle test. The magnet is a conventional tape-wound quadrupole electromagnet, using iron pole- pieces, with the addition of permanent magnet material (neodymium iron) between the poles to reduce the effects of saturation. The iron is preloaded with magnetic flux generated by the permanent magnet material, resulting in an asymmetrical saturation curve. Since the polarity of the quadrupole magnets in a drift tube linac is not reversed we can take advantage of this asymmetrical saturation to provide greater focusing strength. The magnet configuration has been optimized and the vanadium permendur poles needed in a conventional quadrupole have been replaced with iron poles. The use of permanent magnet material has allowed us to increase the focusing strength of the magnet by about 20% over that of a conventional tape-wound quadrupole. Comparisons will be made between this magnet and the conventional tape-wound quadrupole. 3 refs., 5 figs.
New techniques for the scientific visualization of three-dimensional multi-variate and vector fields
Crawfis, R.A.
1995-10-01T23:59:59.000Z
Volume rendering allows us to represent a density cloud with ideal properties (single scattering, no self-shadowing, etc.). Scientific visualization utilizes this technique by mapping an abstract variable or property in a computer simulation to a synthetic density cloud. This thesis extends volume rendering from its limitation of isotropic density clouds to anisotropic and/or noisy density clouds. Design aspects of these techniques are discussed that aid in the comprehension of scientific information. Anisotropic volume rendering is used to represent vector based quantities in scientific visualization. Velocity and vorticity in a fluid flow, electric and magnetic waves in an electromagnetic simulation, and blood flow within the body are examples of vector based information within a computer simulation or gathered from instrumentation. Understand these fields can be crucial to understanding the overall physics or physiology. Three techniques for representing three-dimensional vector fields are presented: Line Bundles, Textured Splats and Hair Splats. These techniques are aimed at providing a high-level (qualitative) overview of the flows, offering the user a substantial amount of information with a single image or animation. Non-homogenous volume rendering is used to represent multiple variables. Computer simulations can typically have over thirty variables, which describe properties whose understanding are useful to the scientist. Trying to understand each of these separately can be time consuming. Trying to understand any cause and effect relationships between different variables can be impossible. NoiseSplats is introduced to represent two or more properties in a single volume rendering of the data. This technique is also aimed at providing a qualitative overview of the flows.
Introduction Magnetic Anisotropy of
Rossak, Wilhelm R.
not completely understood interesting for dilute magnetic semiconductors (DMSs) transparent ferromagnets
Magnetic Imaging Wolfgang Kuch
Kuch, Wolfgang
Magnetic Imaging Wolfgang Kuch Freie UniversitÂ¨at Berlin, Institut fÂ¨ur Experimentalphysik, Arnimallee 14, 14195 Berlin, Germany kuch@physik.fu-berlin.de Abstract. Imaging of magnetic domains has- ern techniques is used nowadays routinely for magnetic imaging of magnetic ma- terials
Superconducting Magnet Division
McDonald, Kirk
Superconducting Magnet Division Ramesh Gupta 20T Target Solenoid with HTS Insert Solenoid Capture Laboratory New York, USA http://www.bnl.gov/magnets/staff/gupta #12;Superconducting Magnet Division Ramesh of HTS may significantly reduce the amount of Tungsten shielding Â· Summary #12;Superconducting Magnet
Jiang, Chaowei
2015-01-01T23:59:59.000Z
In the solar corona, magnetic flux rope is believed to be a fundamental structure accounts for magnetic free energy storage and solar eruptions. Up to the present, the extrapolation of magnetic field from boundary data is the primary way to obtain fully three-dimensional magnetic information of the corona. As a result, the ability of reliable recovering coronal magnetic flux rope is important for coronal field extrapolation. In this paper, our coronal field extrapolation code (CESE-MHD-NLFFF, Jiang & Feng 2012) is examined with an analytical magnetic flux rope model proposed by Titov & Demoulin (1999), which consists of a bipolar magnetic configuration holding an semi-circular line-tied flux rope in force-free equilibrium. By using only the vector field in the bottom boundary as input, we test our code with the model in a representative range of parameter space and find that the model field is reconstructed with high accuracy. Especially, the magnetic topological interfaces formed between the flux rop...
The Variable Vector Countermeasure Suit for space habitation and exploration
Vasquez, Rebecca (Rebecca Ann)
2014-01-01T23:59:59.000Z
The Variable Vector Countermeasure Suit (V2Suit) is a countermeasure suit for sensorimotor adaptation and musculoskeletal deconditioning in microgravity. The V2suit will consist of modules containing arrays of control ...
Hamiltonian Vector Fields on Multiphase Spaces of Classical Field Theory
Michael Forger; Mário Otávio Salles
2010-10-02T23:59:59.000Z
We present a classification of hamiltonian vector fields on multisymplectic and polysymplectic fiber bundles closely analogous to the one known for the corresponding dual jet bundles that appear in the multisymplectic and polysymplectic approach to first order classical field theories.
ASYMPTOTIC THEORY FOR A VECTOR ARMA-GARCH MODEL
Ling, Shiqing
ASYMPTOTIC THEORY FOR A VECTOR ARMA-GARCH MODEL SHHHIIIQQQIIINNNGGG LIIINNNGGG Hong Kong University conditional heteroskedasticity ~ARMA- GARCH! model+ The conditions for the strict stationarity, the ergodicity for the univariate auto- regressive conditional heteroskedasticity ~ARCH! and GARCH models+ More- over
3.3 Construction of vector edge elements
2011-10-05T23:59:59.000Z
Figure 3.1: Linear tetrahedral element. 3.3 Construction of vector edge elements. Let us first consider the linear tetrahedral element, as seen in Figure 3.1. Within.
A vector-free microfluidic platform for intracellular delivery
Sharei, Armon Reza
Intracellular delivery of macromolecules is a challenge in research and therapeutic applications. Existing vector-based and physical methods have limitations, including their reliance on exogenous materials or electrical ...
Syllabus for MATH 362 Spring 2015: Topics in Vector Calculus
2014-12-23T23:59:59.000Z
Page 1. Syllabus for MATH 362 Spring 2015: Topics in Vector Calculus. Alex Misiats omisiats@purdue.edu. December 23, 2014. Lectures: MWF, 12:30 - 1:20
Off-shell Bethe vectors and Drinfeld currents
Sergey Khoroshkin; Stanislav Pakuliak; Vitaly Tarasov
2006-12-12T23:59:59.000Z
In this paper we compare two constructions of weight functions (off-shell Bethe vectors) for the quantum affine algebra $U_q(\\hat{\\mathfrak{gl}}_N)$. The first construction comes from the algebraic nested Bethe ansatz. The second one is defined in terms of certain projections of products of Drinfeld currents. We show that two constructions give the same result in tensor products of vector representations of $U_q(\\hat{\\mathfrak{gl}}_N)$.
Trellis coded vector quantization for the intraframe coding of images
Chauvin, Todd Henry
1989-01-01T23:59:59.000Z
quantization in both conligurations. The design algo- rithm is also developed for the case of a, constrainl, on the entropy of the channel indices. Performance is evaluated by computer simulation for a variety of encoding rates, number of trellis states.... Rate Expansion . 2. Set Partitioning 3. Viterbi Encoding . C. Codebook Design 15 15 17 17 23 28 29 IV PREDICTIVE TRELLIS CODED VECTOR QUANTIZATION. . . 30 A. Implementation Structure . B. Design of Predictive TCVQ Coders 1. Vector...
Magnetic Landscape of Sun's Polar Region
S. Tsuneta; K. Ichimoto; Y. Katsukawa; B. W. Lites; K. Matsuzaki; S. Nagata; D. Orozco Suarez; T. Shimizu; M. Shimojo; R. A. Shine; Y. Suematsu; T. K. Suzuki; T. D. Tarbell; A. M. Title
2008-08-08T23:59:59.000Z
We present the magnetic landscape of the polar region of the Sun that is unprecedented in terms of high spatial resolution, large field of view, and polarimetric precision. These observations were carried out with the Solar Optical Telescope aboard \\emph{Hinode}. Using a Milne-Eddington inversion, we found many vertically-oriented magnetic flux tubes with field strength as strong as 1 kG that are scattered in latitude between 70-90 degree. They all have the same polarity, consistent with the global polarity of the polar region. The field vectors were observed to diverge from the center of the flux elements, consistent with a view of magnetic fields that expand and fan out with height. The polar region is also covered with ubiquitous horizontal fields. The polar regions are the source of the fast solar wind channelled along unipolar coronal magnetic fields whose photospheric source is evidently rooted in the strong field, vertical patches of flux. We conjecture that vertical flux tubes with large expansion around the photosphere-corona boundary serve as efficient chimneys for Alfven waves that accelerate the solar wind.
Geek-Up[10.01.10] -- Mapping Bioenergy and Magnetic Vector Potential...
Broader source: Energy.gov (indexed) [DOE]
of aerosols such as concentration, size distributions, light scattering, light absorption and propensity for cloud formation." The word sour is not only fitting to describe...
Properties of the low-lying electronic states of phenanthrene: Exact PPP results
Chakrabarti, A.; Ramasesha, S. [Indian Institute of Science, Bangalore (India)] [Indian Institute of Science, Bangalore (India)
1996-10-05T23:59:59.000Z
The authors report properties of the exact low-lying states of phenanthrene, its anion and dianion within the Pariser-Parr-Pople (PPP) model. The experimentally known singlet states of the neutral molecule are well reproduced by the model. The intensities for one and two photon absorption to various single states are also in good agreement with experiment. From the bond orders of these states, the authors predict the equilibrium geometries. The relaxation energies of these states, computed from charge-charge correlations and bond orders, are presented. The authors also present results of ring current calculations in the singlet ground state of phenanthrene. The authors have also reported energies, spin densities, bond orders, and relaxation energies of several triplet states and compared then with experiments as well as with other calculations, where available. The fine structure constants D and E, computed in the lowest triplet state, compare well with those obtained from experiments. These properties are also presented for the anions and the dianions. The PPP model in these cases predicts a low-energy (< 1 eV) dipole excitation. 31 refs., 4 figs., 9 tabs.
Varieties of nilpotent elements for simple Lie algebras. II. Bad primes.
Georgia Vigre; Algebra Group; David J. Benson; Philip Bergonio; Brian D; Leonard Chastkofsky; Bobbe Cooper; G. Michael Guy; Jeremiah Hower; Markus Hunziker
Let G be a simple algebraic group over an algebraically closed field k of characteristic p ? 0 with Lie algebra g. Denote the set of nilpotent elements in g (resp. unipotent elements in G) by N(g) (resp. U(G)). For a nontrivial representation ?: G ? GL(V) of G and a positive integer r, we set Nr,?(g) = {x ? N(g) | d?(x) r = 0} and Ur,?(G) = {x ? U(G) | (?(x) ? 1) r = 0}. In the special case where r = p> 0, the varieties Np,?(g) and Up,?(G) do not depend on ?, and they are denoted by N1(g) and U1(G) respectively. In the paper under review the authors give explicit descriptions of the varieties Nr,?(g) and Ur,?(G) as unions of the orbit closures when p is bad for G and ? is the minimal or the adjoint representation (the case where p is good was already treated in Part I [J. Algebra 280 (2004), no. 2, 719–737; MR2090060 (2005h:17016)]). Together with the result in Part I, the following results are established for all primes p: the varieties N1(g) and U1(G) are irreducible, and there exists an order-preserving bijection between N1(g) and U1(G).
Non-Hermitian systems of Euclidean Lie algebraic type with real energy spectra
Dey, Sanjib, E-mail: sanjib.dey.1@city.ac.uk; Fring, Andreas, E-mail: a.fring@city.ac.uk; Mathanaranjan, Thilagarajah, E-mail: thilagarajah.mathanaranjan.1@city.ac.uk
2014-07-15T23:59:59.000Z
We study several classes of non-Hermitian Hamiltonian systems, which can be expressed in terms of bilinear combinations of Euclidean–Lie algebraic generators. The classes are distinguished by different versions of antilinear (PT)-symmetries exhibiting various types of qualitative behaviour. On the basis of explicitly computed non-perturbative Dyson maps we construct metric operators, isospectral Hermitian counterparts for which we solve the corresponding time-independent Schrödinger equation for specific choices of the coupling constants. In these cases general analytical expressions for the solutions are obtained in the form of Mathieu functions, which we analyze numerically to obtain the corresponding energy spectra. We identify regions in the parameter space for which the corresponding spectra are entirely real and also domains where the PT symmetry is spontaneously broken and sometimes also regained at exceptional points. In some cases it is shown explicitly how the threshold region from real to complex spectra is characterized by the breakdown of the Dyson maps or the metric operator. We establish the explicit relationship to models currently under investigation in the context of beam dynamics in optical lattices. -- Highlights: •Different PT-symmetries lead to qualitatively different systems. •Construction of non-perturbative Dyson maps and isospectral Hermitian counterparts. •Numerical discussion of the eigenvalue spectra for one of the E(2)-systems. •Established link to systems studied in the context of optical lattices. •Setup for the E(3)-algebra is provided.
A finite subgroup of the exceptional Lie group G 2 R C Kingyx F Toumazetz--and B. G. Wybourne#%
Toumazet, Frédéric
of the rotation group in seven dimensions, SO(7), and furthermore, that the physical rotation group SO(3A finite subgroup of the exceptional Lie group G 2 R C Kingyx F Toumazetz-- and B. G. Wybourne#% y Abstract. With a view to further refining the use of the exceptional group G 2 in atomic and nuclear
Chapman, Robin
's eight term exact sequence in integral group homology [BrLo] to an eight term exact sequence in group of nonabelian derived functors, an eight term exact sequence of Lie algebra homology with /q coefficients homology with Zq = Z/qZ coefficients, where q is a nonnegative integer. For any group G and its normal
Saldin, Dilano
Germany lies in the heart of Europe where more people speak German as their native language than any other language in Europe. Germany has a population of about 83 million and is the most populous- wide? As a nation, Germany has one of the top ten econo- mies in the world. It is the home
Yoshinaga, N. [Department of Physics, Saitama University, Saitama City 338-8570 (Japan); Arima, A. [Science Museum, Japan Science Foundation, 2-1 Kitanomaru-koen, Chiyoda ku, Tokyo 102-0091 (Japan)
2010-04-15T23:59:59.000Z
We propose some new, efficient, and practical extrapolation methods to obtain a few low-lying eigenenergies of a large-dimensional Hamiltonian matrix in the nuclear shell model. We obtain those energies at the desired accuracy by extrapolation after diagonalizing small-dimensional submatrices of the sorted Hamiltonian matrix.
of security, and secure transaction processing. My recent research has expanded beyond information systemsResearch With Students My principal research activities lie in information systems security and mining, semantic web and multimedia delivery. 1 Major Results · Security solutions for workflow systems
Plotkin, Joshua B.
Center for Bioinformatics, which provide a focus for genomics and computational biology on the PennGenomics and Computational Biology lie at the center of a rapid convergence of biomedical research in genomics, as well as computational activities in bioinformatics. Students and faculty in Penn's Genomics
California at Santa Cruz, University of
are the traceless hermitian generators of the Lie algebra su(3), analogous to the Pauli matrices of su(2). The eight
California at Santa Cruz, University of
are the traceless hermitian generators of the Lie algebra su(3), analogous to the Pauli matrices of su(2). The eight
Nanocomposite Magnets: Transformational Nanostructured Permanent Magnets
None
2010-10-01T23:59:59.000Z
Broad Funding Opportunity Announcement Project: GE is using nanomaterials technology to develop advanced magnets that contain fewer rare earth materials than their predecessors. Nanomaterials technology involves manipulating matter at the atomic or molecular scale, which can represent a stumbling block for magnets because it is difficult to create a finely grained magnet at that scale. GE is developing bulk magnets with finely tuned structures using iron-based mixtures that contain 80% less rare earth materials than traditional magnets, which will reduce their overall cost. These magnets will enable further commercialization of HEVs, EVs, and wind turbine generators while enhancing U.S. competitiveness in industries that heavily utilize these alternatives to rare earth minerals.
Magnetic field distribution in the plasma flow generated by a plasma focus discharge
Mitrofanov, K. N., E-mail: mitrofan@triniti.ru [Troitsk Institute for Innovaiton and Fusion Research (Russian Federation); Krauz, V. I., E-mail: krauz_vi@nrcki.ru; Myalton, V. V.; Velikhov, E. P.; Vinogradov, V. P.; Vinogradova, Yu. V. [National Research Centre Kurchatov Institute (Russian Federation)
2014-11-15T23:59:59.000Z
The magnetic field in the plasma jet propagating from the plasma pinch region along the axis of the chamber in a megajoule PF-3 plasma focus facility is studied. The dynamics of plasma with a trapped magnetic flow is analyzed. The spatial sizes of the plasma jet region in which the magnetic field concentrates are determined in the radial and axial directions. The magnetic field configuration in the plasma jet is investigated: the radial distribution of the azimuthal component of the magnetic field inside the jet is determined. It is shown that the magnetic induction vector at a given point in space can change its direction during the plasma flight. Conclusions regarding the symmetry of the plasma flow propagation relative to the chamber axis are drawn.
Mueller, Fred M. (Los Alamos, NM); Bronisz, Lawrence (Los Alamos, NM); Grube, Holger (Los Alamos, NM); Nelson, David C. (Santa Fe, NM); Mace, Jonathan L. (Los Alamos, NM)
2006-11-14T23:59:59.000Z
A magnetic infrasound sensor is produced by constraining a permanent magnet inside a magnetic potential well above the surface of superconducting material. The magnetic infrasound sensor measures the position or movement of the permanent magnet within the magnetic potential well, and interprets the measurements. Infrasound sources can be located and characterized by combining the measurements from one or more infrasound sensors. The magnetic infrasound sensor can be tuned to match infrasound source types, resulting in better signal-to-noise ratio. The present invention can operate in frequency modulation mode to improve sensitivity and signal-to-noise ratio. In an alternate construction, the superconductor can be levitated over a magnet or magnets. The system can also be driven, so that time resolved perturbations are sensed, resulting in a frequency modulation version with improved sensitivity and signal-to-noise ratio.
Ultrafast Magnetism Dynamics Measure Using Tabletop Ultrafast EUV Sources
Silva, Thomas J. [NIST] [NIST; Murnane, Margaret [University of Colorado] [University of Colorado
2013-08-21T23:59:59.000Z
In our work to date, we made two significant advances. First we demonstrated element-selective demagnetization dynamics for the first time, with a record time resolution for x-ray probing of 55 fs. Second, in new work, we were able to probe the timescale of the exchange interaction in magnetic materials, also for the first time. Our measurements were made using the transverse magneto-optic Kerr effect (T-MOKE) geometry, since the reflectivity of a magnetic material changes with the direction of the magnetization vector of a surface. In our experiment, we periodically reversed the magnetization direction of a grating structure made of Permalloy (Ni80Fe20) using an external magnetic field. To achieve maximum contrast, we used HHG light spanning the M-shell (3p) absorption edges of Fe and Ni. Our characterization of the static magnetization of a Permalloy sample shows high magnetic asymmetry at photon energies just above and below the absorption edges at 55 eV and 65 eV, respectively. This result is in excellent agreement with measurements done on the same using a synchrotron source.
Transient horizontal magnetic fields in solar plage regions
R. Ishikawa; S. Tsuneta; K. Ichimoto; H. Isobe; Y. Katsukawa; B. W. Lites; S. Nagata; T. Shimizu; R. A. Shine; Y. Suematsu; T. D. Tarbell; A. M. Title
2008-02-13T23:59:59.000Z
We report the discovery of isolated, small-scale emerging magnetic fields in a plage region with the Solar Optical Telescope aboard Hinode. Spectro-polarimetric observations were carried out with a cadence of 34 seconds for the plage region located near disc center. The vector magnetic fields are inferred by Milne-Eddington inversion. The observations reveal widespread occurrence of transient, spatially isolated horizontal magnetic fields. The lateral extent of the horizontal magnetic fields is comparable to the size of photospheric granules. These horizontal magnetic fields seem to be tossed about by upflows and downflows of the granular convection. We also report an event that appears to be driven by the magnetic buoyancy instability. We refer to buoyancy-driven emergence as type1 and convection-driven emergence as type2. Although both events have magnetic field strengths of about 600 G, the filling factor of type1 is a factor of two larger than that of type2. Our finding suggests that the granular convection in the plage regions is characterized by a high rate of occurrence of granular-sized transient horizontal fields.
Tamper resistant magnetic stripes
Naylor, Richard Brian (Albuquerque, NM); Sharp, Donald J. (Albuquerque, NM)
1999-01-01T23:59:59.000Z
This invention relates to a magnetic stripe comprising a medium in which magnetized particles are suspended and in which the encoded information is recorded by actual physical rotation or alignment of the previously magnetized particles within the flux reversals of the stripe which are 180.degree. opposed in their magnetic polarity. The magnetized particles are suspended in a medium which is solid, or physically rigid, at ambient temperatures but which at moderately elevated temperatures, such as 40.degree. C., is thinable to a viscosity permissive of rotation of the particles therein under applications of moderate external magnetic field strengths within acceptable time limits.
Formation of Moving Magnetic Features and Penumbral Magnetic Fields with Hinode/SOT
Masahito Kubo; Kiyoshi Ichimoto; Toshifumi Shimizu; Saku Tsuneta; Yoshinori Suematsu; Yukio Katsukawa; Shin'ichi Nagata; Theodore D Tarbell; Richard A Shine; Alan M Title; Zoe A Frank; Bruce W Lites; David Elmore
2007-09-12T23:59:59.000Z
Vector magnetic fields of moving magnetic features (MMFs) are well observed with the Solar Optical Telescope (SOT) aboard the Hinode satellite. We focus on the evolution of three MMFs with the SOT in this study. We found that an MMF having relatively vertical fields with polarity same as the sunspot is detached from the penumbra around the granules appeared in the outer penumbra. This suggests that granular motions in the outer penumbra are responsible for the disintegration of the sunspot. Two MMFs with polarity opposite to the sunspot are located around the outer edge of horizontal fields extending from the penumbra. This is an evidence that the MMFs with polarity opposite to the sunspot are prolongation of penumbral horizontal fields. Radshifts larger than sonic velocity in the photosphere are detected for some of the MMFs with polarity opposite to the sunspot.
Journal of Magnetism and Magnetic Materials ] (
McHenry, Michael E.
magnetic properties were measured with a vibrating sample magnetometer. The mass-specific power loss.40.Rs Keywords: Nanocrystalline alloys; Amorphous alloys; Field annealing; Power loss; Soft magnets the hysteretic power loss while maintaining high-temperature operability [4]. Other goals have included studies
Plasma sweeper to control the coupling of RF power to a magnetically confined plasma
Motley, Robert W. (Princeton, NJ); Glanz, James (Lawrenceville, NJ)
1985-01-01T23:59:59.000Z
A device for coupling RF power (a plasma sweeper) from a phased waveguide array for introducing RF power to a plasma having a magnetic field associated therewith comprises at least one electrode positioned near the plasma and near the phased waveguide array; and a potential source coupled to the electrode for generating a static electric field at the electrode directed into the plasma and having a component substantially perpendicular to the plasma magnetic field such that a non-zero vector cross-product of the electric and magnetic fields exerts a force on the plasma causing the plasma to drift.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
for magnetic circular dichroism (XMCD) and magnetic scattering experiments. Sunset Yellow 6-ID-B: Resonant and In-Field Scattering Beamline 6-ID-B,C is the primary beamline on...
Buz, Jennifer
2011-01-01T23:59:59.000Z
The magnetization of young lunar samples (magnetic fields (e.g. core dynamo and long-lived impact plasma fields) have not been present within the last 1.5 Ga. To better ...
Barclay, John A. (Los Alamos, NM); Steyert, William A. (Los Alamos, NM)
1982-01-01T23:59:59.000Z
The disclosure is directed to an active magnetic regenerator apparatus and method. Brayton, Stirling, Ericsson, and Carnot cycles and the like may be utilized in an active magnetic regenerator to provide efficient refrigeration over relatively large temperature ranges.
Raizen, Mark G.
The world relies today on enriched isotopes for medicine, basic science and energy, and the need will only excitation, and similarly requires high-power lasers. A lower power laser isotope enrichment (LIE) methodMagnetically activated and guided isotope separation This article has been downloaded from
Magnetism Theory Group / POSTECH Magnetism Theory Group / POSTECH
Min, Byung Il
Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH #12;Magnetism Theory Group / POSTECH J.H . Park et al. #12;'s of FeinCsm e tal The chargeandorbitalordering geom etryin YB a C o 2 O 5 S. K. Kwon etal .Magnetism Theory
Magnetic susceptibility in QCD
V. D. Orlovsky; Yu. A. Simonov
2014-05-12T23:59:59.000Z
Magnetic susceptibility in the deconfined phase of QCD is calculated in a closed form using a recent general expression for the quark gas pressure in magnetic field. Quark selfenergies are entering the result via Polyakov line factors and ensure the total paramagnetic effect, increasing with temperature. A generalized form of magnetic susceptibility in nonzero magnetic field suitable for experimental and lattice measurements is derived, showing a good agreement with available lattice data.
Spectrum of Perturbations in Anisotropic Inflationary Universe with Vector Hair
Burak Himmetoglu
2009-10-27T23:59:59.000Z
We study both the background evolution and cosmological perturbations of anisotropic inflationary models supported by coupled scalar and vector fields. The models we study preserve the U(1) gauge symmetry associated with the vector field, and therefore do not possess instabilities associated with longitudinal modes (which instead plague some recently proposed models of vector inflation and curvaton). We first intoduce a model in which the background anisotropy slowly decreases during inflation; we then confirm the stability of the background solution by studying the quadratic action for all the perturbations of the model. We then compute the spectrum of the $h_{\\times}$ gravitational wave polarization. The spectrum we find breaks statistical isotropy at the largest scales and reduces to the standard nearly scale invariant form at small scales. We finally discuss the possible relevance of our results to the large scale CMB anomalies.
New dynamo pattern revealed by solar helical magnetic fields
Zhang, Hongqi; Pevtsov, A; Gao, Yu; Xu, Haiqing; Sokoloff, D D; Kuzanyan, K
2009-01-01T23:59:59.000Z
Previously unobservable mirror asymmetry of the solar magnetic field -- a key ingredient of the dynamo mechanism which is believed to drive the 11-year activity cycle -- has now been measured. This was achieved through systematic monitoring of solar active regions carried out for more than 20 years at observatories in Mees, Huairou, and Mitaka. In this paper we report on detailed analysis of vector magnetic field data, obtained at Huairou Solar Observing Station in China. Electric current helicity (the product of current and magnetic field component in the same direction) was estimated from the data and a latitude-time plot of solar helicity during the last two solar cycles has been produced. We find that like sunspots helicity patterns propagate equatorwards but unlike sunspot polarity helicity in each solar hemisphere does not change sign from cycle to cycle - confirming the theory. There are, however, two significant time-latitudinal domains in each cycle when the sign does briefly invert. Our findings she...
Magnetic nanohole superlattices
Liu, Feng
2013-05-14T23:59:59.000Z
A magnetic material is disclosed including a two-dimensional array of carbon atoms and a two-dimensional array of nanoholes patterned in the two-dimensional array of carbon atoms. The magnetic material has long-range magnetic ordering at a temperature below a critical temperature Tc.
Kravtsov, Yu. A. [Space Research Institute, Profsoyuznaya St. 82/34, Moscow 117997 (Russian Federation); Institute of Physics, Maritime University of Szczecin, Waly Chrobrego 1/., 70-500 Szczecin (Poland); Bieg, B. [Institute of Physics, Maritime University of Szczecin, Waly Chrobrego 1/., 70-500 Szczecin (Poland); Bliokh, K. Yu. [Institute of Radio Astronomy, 4 Krasnoznamyonnaya St., Kharkov 61002 (Ukraine); Optical Engineering Laboratory, Faculty of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Hirsch, M. [Max Planck Institute for Plasma Physics, Greifswald, Wendelsteinstrasse D-17491 (Germany)
2008-03-19T23:59:59.000Z
Three different theoretical approaches are presented: quasi-isotropic approximation (QIA), Stokes vector formalism and complex polarization angle method, which allow describing polarization of electromagnetic waves in weakly anisotropic plasma. QIA stems directly from the Maxwell equations under assumption of weak anisotropy and has a form of coupled differential equations for the transverse components of the electromagnetic wave field. Being applied to high frequency (microwave or IR) electromagnetic waves in magnetized plasma, QIA describes combined action of Faraday and Cotton-Mouton phenomena. QIA takes into account curvature and torsion of the ray, describes normal modes conversion in the inhomogeneous plasma and allows specifying area of applicability of the method.In distinction to QIA, Stokes vector formalism (SVF) deals with quantities, quadratic in a wave field. It is shown (and this is the main result of the paper) that equation for Stokes vector evolution can be derived directly from QIA. This evidences deep unity of two seemingly different approaches. In fact QIA suggests somewhat more information than SVF; in particular, it describes the phases of both transverse components of the electromagnetic field, whereas SVF operates only with the phase difference.At last, the coupled equations of the quasi-isotropic approximation can be reduced to a single equation for complex polarization angle (CPA), which describes both the shape and orientation of the polarization ellipse. In turn, equation for CPA allows obtaining equations for traditional parameters of polarization ellipse, which in fact are equivalent to the equation for Stokes vector evolution. It is pointed out that every method under discussion has its own advantages plasma polarimetry.
Computing nonlinear force free coronal magnetic fields
T. Wiegelmann; T. Neukirch
2008-01-21T23:59:59.000Z
Knowledge of the structure of the coronal magnetic field is important for our understanding of many solar activity phenomena, e.g. flares and CMEs. However, the direct measurement of coronal magnetic fields is not possible with present methods, and therefore the coronal field has to be extrapolated from photospheric measurements. Due to the low plasma beta the coronal magnetic field can usually be assumed to be approximately force free, with electric currents flowing along the magnetic field lines. There are both observational and theoretical reasons which suggest that at least prior to an eruption the coronal magnetic field is in a nonlinear force free state. Unfortunately the computation of nonlinear force free fields is way more difficult than potential or linear force free fields and analytic solutions are not generally available. We discuss several methods which have been proposed to compute nonlinear force free fields and focus particularly on an optimization method which has been suggested recently. We compare the numerical performance of a newly developed numerical code based on the optimization method with the performance of another code based on an MHD relaxation method if both codes are applied to the reconstruction of a semi-analytic nonlinear force-free solution. The optimization method has also been tested for cases where we add random noise to the perfect boundary conditions of the analytic solution, in this way mimicking the more realistic case where the boundary conditions are given by vector magnetogram data. We find that the convergence properties of the optimization method are affected by adding noise to the boundary data and we discuss possibilities to overcome this difficulty.
Kinetic models of current sheets with a sheared magnetic field
Mingalev, O. V.; Mingalev, I. V.; Mel'nik, M. N. [Russian Academy of Sciences, Polar Geophysical Institute, Cola Science Center (Russian Federation); Artemyev, A. V.; Malova, H. V.; Popov, V. Yu. [Russian Academy of Sciences, Space Research Institute (Russian Federation); Chao, Shen [Chinese Academy of Sciences, Center for Space Science and Applied Research (China); Zelenyi, L. M. [Russian Academy of Sciences, Space Research Institute (Russian Federation)
2012-04-15T23:59:59.000Z
Thin current sheets, whose existence in the Earth's magnetotail is confirmed by numerous spacecraft measurements, are studied analytically and numerically. The thickness of such sheets is on the order of the ion Larmor radius, and the normal component of the magnetic field (B{sub z}) in the sheet is almost constant, while the tangential (B{sub x}) and shear (B{sub y}) components depend on the transverse coordinate z. The current density in the sheet also has two self-consistent components (j{sub x} and j{sub y}, respectively), and the magnetic field lines are deformed and do not lie in a single plane. To study such quasi-one-dimensional current configurations, two kinetic models are used, in particular, a numerical model based on the particle-in-cell method and an analytical model. The calculated results show that two different modes of the self-consistent shear magnetic field B{sub y} and, accordingly, two thin current sheet configurations can exist for the same input parameters. For the mode with an antisymmetric z profile of the B{sub y} component, the magnetic field lines within the sheet are twisted, whereas the profiles of the plasma density, current density component j{sub y}, and magnetic field component B{sub x} differ slightly from those in the case of a shearless magnetic field (B{sub y} = 0). For the symmetric B{sub y} mode, the magnetic field lines lie in a curved surface. In this case, the plasma density in the sheet varies slightly and the current sheet is two times thicker. Analysis of the dependence of the current sheet structure on the flow anisotropy shows that the sheet thickness decreases significantly with decreasing ratio between the thermal and drift plasma velocities, which is caused by the dynamics of quasi-adiabatic ions. It is shown that the results of the analytical and numerical models are in good agreement. The problems of application of these models to describe current sheets at the magnetopause and near magnetic reconnection regions are discussed.
Mean-field analysis of ground state and low-lying electric dipole strength in $^{22}$C
Tsunenori Inakura; W. Horiuchi; Y. Suzuki; T. Nakatsukasa
2014-05-30T23:59:59.000Z
Properties of neutron-rich $^{22}$C are studied using the mean-field approach with Skyrme energy density functionals. Its weak binding and large total reaction cross section, which are suggested by recent experiments, are simulated by modifying the central part of Skyrme potential. Calculating $E1$ strength distribution by using the random-phase approximation, we investigate developments of low-lying electric dipole ($E1$) strength and a contribution of core excitations of $^{20}$C. As the neutron Fermi level approaches the zero energy threshold ($\\varepsilon_F >\\sim -1$ MeV), we find that the low-lying $E1$ strength exceeds the energy-weighted cluster sum rule, which indicates an importance of the core excitations with the $1d_{5/2}$ orbit.
[New hosts and vectors for genome cloning]. Progress report
Not Available
1991-12-31T23:59:59.000Z
The main goal of our project remains the development of new bacterial hosts and vectors for the stable propagation of human DNA clones in E. coli. During the past six months of our current budget period, we have (1) continued to develop new hosts that permit the stable maintenance of unstable features of human DNA, and (2) developed a series of vectors for (a) cloning large DNA inserts, (b) assessing the frequency of human sequences that are lethal to the growth of E. coli, and (c) assessing the stability of human sequences cloned in M13 for large-scale sequencing projects.
Magnetically attached sputter targets
Makowiecki, D.M.; McKernan, M.A.
1994-02-15T23:59:59.000Z
An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material is described. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly. 11 figures.
The chiral magnetic nanomotors
Morozov, Konstantin I
2013-01-01T23:59:59.000Z
Propulsion of the chiral magnetic nanomotors powered by a rotating magnetic field is in the focus of the modern biomedical applications. This technology relies on strong interaction of dynamic and magnetic degrees of freedom of the system. Here we study in detail various experimentally observed regimes of the helical nanomotor orientation and propulsion depending on the actuation frequency, and establish the relation of these two properties with remanent magnetization and geometry of the helical nanomotors. The theoretical predictions for the transition between the regimes and nanomotor orientation and propulsion speed are in excellent agreement with available experimental data. The proposed theory offers a few simple guidelines towards the optimal design of the magnetic nanomotors. In particular, efficient nanomotors should be fabricated of hard magnetics, e.g., cobalt, magnetized transversally and have the geometry of a normal helix with a helical angle of 35-45 degrees.
Magnetic helicity and energy spectra of a solar active region
Zhang, Hongqi; Sokoloff, D D
2013-01-01T23:59:59.000Z
We compute magnetic helicity and energy spectra of the solar active region NOAA 11158 during 11-15 February 2011 at 20 degr southern heliographic latitude using observational photospheric vector magnetograms. We adopt the isotropic representation of the Fourier-transformed two-point correlation tensor of the magnetic field. The sign of magnetic helicity turns out to be predominantly positive at all wavenumbers. This sign is consistent with what is theoretically expected for the southern hemisphere. The relative magnetic helicity is around 8% and strongest at intermediate wavenumbers of k ~ 0.4 Mm^{-1}, corresponding to a scale of 2 pi/k ~ 16 Mm. The same sign and a somewhat smaller value is also found for the relative current helicity evaluated in real space based on the vertical components of magnetic field and current density. The current helicity spectrum is estimated from the magnetic helicity spectrum and its modulus shows a k^{-5/3} spectrum at large wavenumbers. A similar power law is also obtained for...
Sheath formation criterion in magnetized electronegative plasmas with thermal ions
Hatami, M. M. [Physics Department of K N Toosi University of Technology, 15418-49611 Tehran (Iran, Islamic Republic of); Shokri, B. [Physics Department and Laser-Plasma Research Institute of Shahid Beheshti University, G. C., Evin, Tehran (Iran, Islamic Republic of)
2013-03-15T23:59:59.000Z
Taking into account the effect of collisions and positive ion temperatures, the sheath formation criterion is investigated in a weakly magnetized electronegative plasma consisting of electrons, negative and positive ions by using the hydrodynamics equations. It is assumed that the electron and negative ion density distributions are the Boltzmann distribution with two different temperatures. Also, it is assumed that the velocity of positive ions at the sheath edge is not normal to the wall (oblique entrance). Our results show that a sheath region will be formed when the initial velocity of positive ions or the ion Mach number M lies in a specific interval with particular upper and lower limits. Also, it is shown that the presence of the magnetic field affects both of these limits. Moreover, as an practical application, the density distribution of charged particles in the sheath region is studied for an allowable value of M, and it is seen that monotonically reduction of the positive ion density distribution leading to the sheath formation occurs only when M lies between two above mentioned limits.
December 2001 Trevor Hastie, Stanford Statistics 1 Support Vector Machines,
Hastie, Trevor
December 2001 Trevor Hastie, Stanford Statistics 1 Support Vector Machines, Kernel Logistic in Optimization and Computational Algorithms (NTOC2001) December 9-13, 2001, Kyodai-Kaikan, Kyoto, Japan http://www-stat.stanford.edu/hastie/Papers/ivmtalk.pdf #12;December 2001 Trevor Hastie, Stanford Statistics 2 Outline Â· Optimal separating hyperplanes
An Equivalence Between Sparse Approximation and Support Vector Machines 1
Poggio, Tomaso
An Equivalence Between Sparse Approximation and Support Vector Machines 1 Federico Girosi Center is equivalent to SVM in the following sense: if applied to the same data set the two techniques give the same; Chen, Donoho and Saunders, 1995), are actually equivalent, in the case of noiseless data. By equivalent
The study of topology of the universe using multipole vectors
P. Bielewicz; A. Riazuelo
2009-04-10T23:59:59.000Z
We study a multipole vector-based decomposition of cosmic microwave background (CMB) data in order to search for signatures of a multiconnected topology of the universe. Using 10^6 simulated maps, we analyse the multipole vector distribution on the sky for the lowest order multipoles together with the probability distribution function of statistics based on the sum of the dot products of the multipole vectors for both the simply-connected flat universe and universes with the topology of a 3-torus. The estimated probabilities of obtaining lower values for these statistics as compared to the 5-year WMAP data indicate that the observed alignment of the quadrupole and octopole is statistically favoured in a 3-torus topology where at least one dimension of the fundamental domain is significantly shorter than the diameter of the observable universe, as compared to the usual standard simply-connected universe. However, none of the obtained results are able to clearly rule out the latter (at more than 97% confidence level). Multipole vector statistics do not appear to be very sensitive to the signatures of a 3-torus topology if the shorter dimension of the domain becomes comparable to the diameter of the observable universe. Unfortunately, the signatures are also significantly diluted by the integrated Sachs-Wolfe effect.
Using Super-Vector Coding for Image Classification and Retrieval
Tian, Qi
.g. SIFT X1 X2 XN 128 N SIFTs Bag-of-Word K-Means clusteringK dim Histogram K × N dim #12;Motivation derivative smooth K-Means (1) (2) #12;Descriptor Coding · Super-Vector (SV) coding #12;Descriptor Coding (2 #12;Experiments - Comparison of nonlinear coding methods |C| = 512 #12;Experiments - Comparison
On the Context-Freeness Problem for Vector Addition Systems
, or equivalently vector addition systems (VAS), are widely recognized as a central model for concurrent systems one of the most studied formalisms for the modeling and analysis of concurrent systems. Despite their fairly large expressive power, many verification problems are decidable for VAS: boundedness
Fusion and the Neveu-Schwarz Singular Vectors
L. Benoit; Y. Saint-Aubin
1992-11-04T23:59:59.000Z
Bauer, Di Francesco, Itzykson and Zuber proposed recently an algorithm to construct all singular vectors of the Virasoro algebra. It is based on the decoupling of (already known) singular fields in the fusion process. We show how to extend their algorithm to the Neveu-Schwarz superalgebra.
Vector Boson Fusion Higgs Production at the LHC - Mass Variables
Dan Green
2005-01-12T23:59:59.000Z
There exist substantial backgrounds to the vector boson fusion production of Higgs at the LHC. Mass variables are studied which may alleviate the need to assume a spin zero WW resonance in order to achieve a sufficient signal to noise ratio in the two jet plus two lepton and missing energy final state.
Fast Bootstrap for Least-square Support Vector Machines
Verleysen, Michel
Fast Bootstrap for Least-square Support Vector Machines A. Lendasse1 , G. Simon2 , V. Wertz3 , M, CESAME, 4 av. G. Lemaître B-1348 Louvain-la-Neuve, Belgium, wertz@auto.ucl.ac.be. Abstract. The Bootstrap of the Bootstrap implies a high computational load. In this paper we present a simple procedure to obtain a fast
Supersymmetric Higgs Production in Vector-Boson Fusion
Michael Rauch; Wolfgang Hollik; Tilman Plehn; Heidi Rzehak
2010-04-14T23:59:59.000Z
We present a full calculation of the supersymmetric NLO corrections to Higgs boson production via vector-boson fusion. The supersymmetric QCD corrections turn out to be significantly smaller than the electroweak ones. These higher-order corrections are an important ingredient to a precision analysis of the Higgs sector at the LHC.
Vector Symbolic Architectures: A New Building Material for Artificial General
Levy, Simon D.
Vector Symbolic Architectures: A New Building Material for Artificial General Intelligence1 Simon D. LEVY a,2 , and Ross GAYLER b a Washington and Lee University, USA b Veda Advantage Solutions, Australia. By directly encoding structure using famil- iar, computationally efficient algorithms, VSA bypasses many
On the Massless Vector Fields in a Rindler Space
Soldati, Roberto
2015-01-01T23:59:59.000Z
We study the quantum theory of the mass-less vector fields on the Rindler space. We evaluate the Bogoliubov coefficients by means of a new technique based upon the use of light-front coordinates and Mellin transform. We briefly comment about the ensuing Unruh effect and its consequences.
On a New 4-Vector Cosmological Field Theory
G. G. Nyambuya
2009-05-05T23:59:59.000Z
The original Dirac Equation is modified in the simplest imaginable and most trivial manner to include a universal 4-Vector Cosmological Field term in the space and time dimensions. This cosmological field leads to a modified Dirac Equation capable of explaining why the Universe appears to be made up chiefly of matter. It is seen that this 4-Vector Cosmological Field is actually a particle field and this particle field can possibly be identified with the darkmatter and darkenergy field. Further, this 4-Vector Cosmological Field is seen to give spacetime the desired quantum mechanical properties of randomness. Furthermore, it is seen that in the emergent Universe, the position coordinates of a particle in space -- contrary to the widely accepted belief that the position of a particle in space has no physical significance, we see that that opposite is true - namely that the position of a particle has physical significance. We further note that the 4-Vector Cosmological Field modification to the Dirac Equation leads us to a vacuum model redolent but different from that of Quantum Electrodynamics (QED). This new vacuum model is without virtual particles but darkparticles. We dare to make the suggestion that these darkparticles may possibly explain the current mystery of what really is darkmatter and darkenergy.
Adventures in Vectorizing the Community Land Model Forrest M. Hoffman
Hoffman, Forrest M.
Institute of Electric Power Industry (CRIEPI) James B. White III, Patrick Worley, and John Drake Oak Ridge) on the IBM Power4, the Earth Simulator, and the Cray X1 are compared. #12;1 Introduction The Community Land-based scalar multi-processor computer platforms and re- sulted in code which would not vectorize. The avail
THE LAW OF VECTOR FIELDS Daniel H. Gottlieb
DANIEL H. GOTTLIEB What do I mean ? Look at the example of Newton's Law of Gravitation. HereTHE LAW OF VECTOR FIELDS Daniel H. Gottlieb 1. Introduction. When I was 13, the intellectual world. Something fantastically beautiful. This something is the existence of a few general laws or principles which
THE LAW OF VECTOR FIELDS Daniel H. Gottlieb
;2 DANIEL H. GOTTLIEB What do I mean ? Look at the example of Newton's Law of Gravitation. Here THE LAW OF VECTOR FIELDS Daniel H. Something fantastically beautiful. This something is the existence of a few general laws or principles which
Statistical traffic classification by Boosting Support Vector Machines
Statistical traffic classification by Boosting Support Vector Machines Gabriel Gómez Sena Facultad years, traffic classification based on the statistical properties of flows has become an important topic. In this paper we statistically analyze the data length of the first few segments exchanged by a transport flow
Evaluation of a Vector Hypercube for Seismic Modelling Seismic modelling
Renaut, Rosemary
Evaluation of a Vector Hypercube for Seismic Modelling Abstract Seismic modelling is a computationally to produce realistic seismic traces intensive problem. A 2D syn- Rosemary Renautt and Johnny equation is the first step in the generation of a synthetic seismogram as an aid in the interpretation
Search for first-generation scalar and vector leptoquarks
Baringer, Philip S.; Bean, Alice; Coppage, Don; Hebert, C.
2001-09-09T23:59:59.000Z
We describe a search for the pair production of first-generation scalar and vector leptoquarks in the eejj and e?jj channels by the DØ Collaboration. The data are from the 1992–1996 pp-bar run at s?=1.8?TeV at the Fermilab Tevatron collider. We find...
Quantization of the Laplacian operator on vector bundles I
Julien Keller; Julien Meyer; Reza Seyyedali
2015-05-14T23:59:59.000Z
Let $(E,h)$ be a holomorphic Hermitian vector bundle over a polarized manifold. We provide a canonical quantization of the Laplacian operator acting on sections of the bundle of Hermitian endomorphisms of $E$. If $E$ is simple we obtain an approximation of the eigenvalues and eigenspaces of the Laplacian.
Covariant Lyapunov Vectors for Rigid Disk Systems Hadrien Bosetti
Posch, Harald A.
Covariant Lyapunov Vectors for Rigid Disk Systems Hadrien Bosetti and Harald A. Posch Computational: October 17, 2010) We carry out extensive computer simulations to study the Lyapunov instability of a two enough to allow the formation of Lyapunov modes parallel to the x-axis of the box. The Oseledec splitting
Probabilistic Wind Vector Forecasting Using Ensembles and Bayesian Model Averaging
Raftery, Adrian
: J. McLean Sloughter, Department of Mathematics, Seattle University, 901 12th Ave., P.O. Box 222000Probabilistic Wind Vector Forecasting Using Ensembles and Bayesian Model Averaging J. MCLEAN SLOUGHTER Seattle University, Seattle, Washington TILMANN GNEITING Heidelberg University, Heidelberg
Relation between photospheric flow fields and the magnetic field distribution on the solar surface
Simon, G.W.; Title, A.M.; Topka, K.P.; Tarbell, T.D.; Shine, R.A.
1988-04-01T23:59:59.000Z
Using the technique of local correlation tracking on a 28 minute time sequence of white-light images of solar granulation, the horizontal flow field on the solar surface is measured. The time series was obtained by the Solar Optical Universal Polarimeter (SOUP) on Spacelab 2 (Space Shuttle flight 51-F) and is free from atmospheric blurring and distortion. The SOUP flow fields have been compared with carefully aligned magnetograms taken over a nine hour period at the Big Bear Solar Observatory before, during, and after the SOUP images. The flow field and the magnetic field agree in considerable detail: vectors which define the flow of the white-light intensity pattern (granulation) point toward magnetic field regions, magnetic fields surround flow cells, and magnetic features move along the flow arrows. The projected locations of free particles (corks) in the measured flow field congregate at the same locations where the magnetic field is observed. 31 references.
Maximum Likelihood Estimation (MLE) of students' understanding of vector subtraction
Zollman, Dean
and Electricity and Magnetism have been collapsed together. In this short paper, we use an easily-understood exam (Mechanics) or second quarter (Electricity and Magnetism) introductory calculus-based physics course homework assignment con- sisted of participating in a one-hour session in a physics education research lab
Vladimir A. Miransky; Igor A. Shovkovy
2015-03-02T23:59:59.000Z
A range of quantum field theoretical phenomena driven by external magnetic fields and their applications in relativistic systems and quasirelativistic condensed matter ones, such as graphene and Dirac/Weyl semimetals, are reviewed. We start by introducing the underlying physics of the magnetic catalysis. The dimensional reduction of the low-energy dynamics of relativistic fermions in an external magnetic field is explained and its role in catalyzing spontaneous symmetry breaking is emphasized. The general theoretical consideration is supplemented by the analysis of the magnetic catalysis in quantum electrodynamics, chromodynamics and quasirelativistic models relevant for condensed matter physics. By generalizing the ideas of the magnetic catalysis to the case of nonzero density and temperature, we argue that other interesting phenomena take place. The chiral magnetic and chiral separation effects are perhaps the most interesting among them. In addition to the general discussion of the physics underlying chiral magnetic and separation effects, we also review their possible phenomenological implications in heavy-ion collisions and compact stars. We also discuss the application of the magnetic catalysis ideas for the description of the quantum Hall effect in monolayer and bilayer graphene, and conclude that the generalized magnetic catalysis, including both the magnetic catalysis condensates and the quantum Hall ferromagnetic ones, lies at the basis of this phenomenon. We also consider how an external magnetic field affects the underlying physics in a class of three-dimensional quasirelativistic condensed matter systems, Dirac semimetals. While at sufficiently low temperatures and zero density of charge carriers, such semimetals are expected to reveal the regime of the magnetic catalysis, the regime of Weyl semimetals with chiral asymmetry is realized at nonzero density...
Vladimir A. Miransky; Igor A. Shovkovy
2015-04-10T23:59:59.000Z
A range of quantum field theoretical phenomena driven by external magnetic fields and their applications in relativistic systems and quasirelativistic condensed matter ones, such as graphene and Dirac/Weyl semimetals, are reviewed. We start by introducing the underlying physics of the magnetic catalysis. The dimensional reduction of the low-energy dynamics of relativistic fermions in an external magnetic field is explained and its role in catalyzing spontaneous symmetry breaking is emphasized. The general theoretical consideration is supplemented by the analysis of the magnetic catalysis in quantum electrodynamics, chromodynamics and quasirelativistic models relevant for condensed matter physics. By generalizing the ideas of the magnetic catalysis to the case of nonzero density and temperature, we argue that other interesting phenomena take place. The chiral magnetic and chiral separation effects are perhaps the most interesting among them. In addition to the general discussion of the physics underlying chiral magnetic and separation effects, we also review their possible phenomenological implications in heavy-ion collisions and compact stars. We also discuss the application of the magnetic catalysis ideas for the description of the quantum Hall effect in monolayer and bilayer graphene, and conclude that the generalized magnetic catalysis, including both the magnetic catalysis condensates and the quantum Hall ferromagnetic ones, lies at the basis of this phenomenon. We also consider how an external magnetic field affects the underlying physics in a class of three-dimensional quasirelativistic condensed matter systems, Dirac semimetals. While at sufficiently low temperatures and zero density of charge carriers, such semimetals are expected to reveal the regime of the magnetic catalysis, the regime of Weyl semimetals with chiral asymmetry is realized at nonzero density...
Observation of high-lying resonances in the H sup minus ion
Harris, P.G. (Los Alamos National Lab., NM (USA) New Mexico Univ., Albuquerque, NM (USA). Dept. of Physics and Astronomy)
1990-05-01T23:59:59.000Z
This dissertation reports the observation of several series of resonances, for which both electrons are in excited states, in the photodetachment cross section of H{sup {minus}}. These {sup 1}P doubly-excited states interfere with the continuum in which they are embedded, and appear as dips in the production cross section of excited neutral hydrogen. The experiment was performed by intersecting an 800 MeV H{sup {minus}} beam with a (266 nm) laser beam at varying angles; the relativistic Doppler shift then tuned'' the photon energy in the barycentric frame. The process was observed by using a magnet strong enough the strip the electrons from the excited hydrogen atoms in selected states n and detecting the resulting protons, which allowed the isolation of the individual n channels. Three resonances are clearly visible in each channel. The data support recent theoretical calculations for the positions of doubly-excited {sup 1}P resonances, and verify a new Rydberg-like formula for the modified Coulomb potential.
Passive magnetic bearing system
Post, Richard F.
2014-09-02T23:59:59.000Z
An axial stabilizer for the rotor of a magnetic bearing provides external control of stiffness through switching in external inductances. External control also allows the stabilizer to become a part of a passive/active magnetic bearing system that requires no external source of power and no position sensor. Stabilizers for displacements transverse to the axis of rotation are provided that require only a single cylindrical Halbach array in its operation, and thus are especially suited for use in high rotation speed applications, such as flywheel energy storage systems. The elimination of the need of an inner cylindrical array solves the difficult mechanical problem of supplying support against centrifugal forces for the magnets of that array. Compensation is provided for the temperature variation of the strength of the magnetic fields of the permanent magnets in the levitating magnet arrays.
Christiansen, D.W.; Brown, W.F.
1984-01-01T23:59:59.000Z
A welder is described for automated closure of fuel pins by a pulsed magnetic process in which the open end of a length of cladding is positioned within a complementary tube surrounded by a pulsed magnetic welder. Seals are provided at each end of the tube, which can be evacuated or can receive tag gas for direct introduction to the cladding interior. Loading of magnetic rings and end caps is accomplished automatically in conjunction with the welding steps carried out within the tube.
Marts, Donna J. (Idaho Falls, ID); Richardson, John G. (Idaho Falls, ID); Albano, Richard K. (Idaho Falls, ID); Morrison, Jr., John L. (Idaho Falls, ID)
1995-01-01T23:59:59.000Z
This invention discloses a D.C. magnetic latching solenoid that retains a moving armature in a first or second position by means of a pair of magnets, thereby having a zero-power requirement after actuation. The first or second position is selected by reversing the polarity of the D.C. voltage which is enough to overcome the holding power of either magnet and transfer the armature to an opposite position. The coil is then de-energized.
Holographic Magnetic Phase Transition
Gilad Lifschytz; Matthew Lippert
2009-06-21T23:59:59.000Z
We study four-dimensional interacting fermions in a strong magnetic field, using the holographic Sakai-Sugimoto model of intersecting D4 and D8 branes in the deconfined, chiral-symmetric parallel phase. We find that as the magnetic field is varied, while staying in the parallel phase, the fermions exhibit a first-order phase transition in which their magnetization jumps discontinuously. Properties of this transition are consistent with a picture in which some of the fermions jump to the lowest Landau level. Similarities to known magnetic phase transitions are discussed.
Magnetic Braids Anthony Yeates
Dundee, University of
flux function Main result Conclusion 2. Thermonuclear confinement devices. ITER (Internat'l Thermonuclear Experimental Reactor). Inside the KSTAR tokamak. Correspond to periodic magnetic braids. 4 / 22
Conceptual design of a thrust-vectoring tailcone for underwater robotics
Nawrot, Michael T
2012-01-01T23:59:59.000Z
Thrust-vectoring on Autonomous Underwater Vehicles is an appealing directional-control solution because it improves turning radius capabilities. Unfortunately, thrust-vectoring requires the entire propulsion system be ...
Kollegala, Revathi
2012-07-16T23:59:59.000Z
of wavelet functions as kernels with Support Vector Data Description for target detection in hyperspectral images. Specifically, it proposes the Adaptive Wavelet Kernel Support Vector Data Description (AWK-SVDD) that learns the optimal wavelet function...
Direct Volume Visualization of Three-Dimensional Vector Fields Roger Crawfis
Crawfis, Roger
. Particle systems [Reeves85] can be used to represent both scalar ([Max90], [Sabella88]) and vector fields
Low-lying isomeric state in {sup 80}Ga from the {beta}{sup -} decay of {sup 80}Zn
LicA, R.; Marginean, N.; Ghita, D.G. [Horia Hulubei National Institute for Physics and Nuclear Engineering, Bucharest (Romania); and others
2012-10-20T23:59:59.000Z
A new level scheme was constructed for {sup 80}Ga which is significantly different from the one previously reported. The excitation energy of a new low-lying state recently reported in [2] was identified at 22.4 keV. Properties of the level scheme suggest that the ground state has spin J = 6 and the first excited state has spin J = 3. The spin assignments are in agreement with laser spectroscopy values previously measured. Our work provides the first evidence for the J = 6 being the ground state.
N. J. MacKay; A. Taylor
2007-11-24T23:59:59.000Z
We use Cvitanovic's diagrammatic techniques to construct the rational solutions of the Yang-Baxter equation associated with the $e_6$ and $e_7$ families of Lie algebras, and thus explain Westbury's observations about their uniform spectral decompositions. In doing so we explore the extensions of the Brauer and symmetric group algebras to the centralizer algebras of $e_7$ and $e_6$ on their lowest-dimensional representations and (up to three-fold) tensor products thereof, giving bases for them and a number of identities satisfied by the algebras' defining invariant tensors.
Charge and magnetization inhomogeneities in diluted magnetic semiconductors
Timm, Carsten
2006-03-01T23:59:59.000Z
It is predicted that III-V diluted magnetic semiconductors can exhibit stripelike modulations of magnetization and carrier concentration. This inhomogeneity results from the strong dependence of the magnetization on the carrier concentration. Within...
Classification using Intersection Kernel Support Vector Machines is Efficient Subhransu Maji
O'Brien, James F.
Classification using Intersection Kernel Support Vector Machines is Efficient Subhransu Maji EECS classification using kernelized SVMs re- quires evaluating the kernel for a test vector and each of the support vectors. For a class of kernels we show that one can do this much more efficiently. In particular we show
Feature Selection for Support Vector Regression in the Application of Building Energy Prediction
Paris-Sud XI, Université de
Feature Selection for Support Vector Regression in the Application of Building Energy Prediction--When using support vector regression to predict building energy consumption, since the energy influence and reduces the computational time. Keywords-support vector regression; feature selection; build- ing; energy
A long state vector Kalman filter for speech enhancement Stephen So and Kuldip K. Paliwal
A long state vector Kalman filter for speech enhancement Stephen So and Kuldip K. Paliwal Signal.so@griffith.edu.au, k.paliwal@griffith.edu.au Abstract In this paper, we investigate a long state vector Kalman filter studies that a vector Kalman filter achieves better enhance- ment than the scalar Kalman filter
Vector and Matrix Operations Programmed with UDFs in a Relational DBMS
Ordonez, Carlos
Vector and Matrix Operations Programmed with UDFs in a Relational DBMS Carlos Ordonez University, a relational DBMS provides limited capabilities to perform multidimensional statistical analysis, which re- quires manipulating vectors and matrices. In this work, we study how to extend a DBMS with basic vector
Lyapunov Vector Fields for Autonomous UAV Flight Control1 Dale A. Lawrence2
Frew, Eric W.
Lyapunov Vector Fields for Autonomous UAV Flight Control1 Dale A. Lawrence2 , Eric. W. Frew3 that incorporate Lyapunov stability properties to produce simple, globally stable vector fields in 3D. Use of the vector field is considered, using Lyapunov techniques to show global stability of heading and path
Neumark, Daniel M.
Study of the low-lying states of Ge2 and Ge2 using negative ion zero electron kinetic energy The low-lying states of Ge2 and Ge2 are probed using negative ion zero electron kinetic energy ZEKE spectroscopy. The ZEKE spectrum of Ge2 yields an electron affinity of 2.035 0.001 eV for Ge2, as well as term
Biosensor method and system based on feature vector extraction
Greenbaum, Elias; Rodriguez, Jr., Miguel; Qi, Hairong; Wang, Xiaoling
2013-07-02T23:59:59.000Z
A system for biosensor-based detection of toxins includes providing at least one time-dependent control signal generated by a biosensor in a gas or liquid medium, and obtaining a time-dependent biosensor signal from the biosensor in the gas or liquid medium to be monitored or analyzed for the presence of one or more toxins selected from chemical, biological or radiological agents. The time-dependent biosensor signal is processed to obtain a plurality of feature vectors using at least one of amplitude statistics and a time-frequency analysis. At least one parameter relating to toxicity of the gas or liquid medium is then determined from the feature vectors based on reference to the control signal.
Biosensor method and system based on feature vector extraction
Greenbaum, Elias (Knoxville, TN); Rodriguez, Jr., Miguel (Oak Ridge, TN); Qi, Hairong (Knoxville, TN); Wang, Xiaoling (San Jose, CA)
2012-04-17T23:59:59.000Z
A method of biosensor-based detection of toxins comprises the steps of providing at least one time-dependent control signal generated by a biosensor in a gas or liquid medium, and obtaining a time-dependent biosensor signal from the biosensor in the gas or liquid medium to be monitored or analyzed for the presence of one or more toxins selected from chemical, biological or radiological agents. The time-dependent biosensor signal is processed to obtain a plurality of feature vectors using at least one of amplitude statistics and a time-frequency analysis. At least one parameter relating to toxicity of the gas or liquid medium is then determined from the feature vectors based on reference to the control signal.
Particle production of vector fields: Scale invariance is attractive
Wagstaff, Jacques M.; Dimopoulos, Konstantinos [Physics Department, Lancaster University, Lancaster LA1 4YB (United Kingdom)
2011-01-15T23:59:59.000Z
In a model of an Abelian vector boson with a Maxwell kinetic term and non-negative mass-squared it is demonstrated that, under fairly general conditions during inflation, a scale-invariant spectrum of perturbations for the components of a vector field, massive or not, whose kinetic function (and mass) is modulated by the inflaton field is an attractor solution. If the field is massless, or if it remains light until the end of inflation, this attractor solution also generates anisotropic stress, which can render inflation weakly anisotropic. The above two characteristics of the attractor solution can source (independently or combined together) significant statistical anisotropy in the curvature perturbation, which may well be observable in the near future.
Multipole structure of current vectors in curved spacetime
Abraham I. Harte
2006-11-17T23:59:59.000Z
A method is presented which allows the exact construction of conserved (i.e. divergence-free) current vectors from appropriate sets of multipole moments. Physically, such objects may be taken to represent the flux of particles or electric charge inside some classical extended body. Several applications are discussed. In particular, it is shown how to easily write down the class of all smooth and spatially-bounded currents with a given total charge. This implicitly provides restrictions on the moments arising from the smoothness of physically reasonable vector fields. We also show that requiring all of the moments to be constant in an appropriate sense is often impossible; likely limiting the applicability of the Ehlers-Rudolph-Dixon notion of quasirigid motion. A simple condition is also derived that allows currents to exist in two different spacetimes with identical sets of multipole moments (in a natural sense).
Prototype Vector Machine for Large Scale Semi-Supervised Learning
Zhang, Kai; Kwok, James T.; Parvin, Bahram
2009-04-29T23:59:59.000Z
Practicaldataminingrarelyfalls exactlyinto the supervisedlearning scenario. Rather, the growing amount of unlabeled data poses a big challenge to large-scale semi-supervised learning (SSL). We note that the computationalintensivenessofgraph-based SSLarises largely from the manifold or graph regularization, which in turn lead to large models that are dificult to handle. To alleviate this, we proposed the prototype vector machine (PVM), a highlyscalable,graph-based algorithm for large-scale SSL. Our key innovation is the use of"prototypes vectors" for effcient approximation on both the graph-based regularizer and model representation. The choice of prototypes are grounded upon two important criteria: they not only perform effective low-rank approximation of the kernel matrix, but also span a model suffering the minimum information loss compared with the complete model. We demonstrate encouraging performance and appealing scaling properties of the PVM on a number of machine learning benchmark data sets.
Boundary filters for vector particles passing parity breaking domains
Kolevatov, S. S.; Andrianov, A. A. [Saint Petersburg State University, 1 ul. Ulyanovskaya, St. Petersburg, 198504 (Russian Federation)
2014-07-23T23:59:59.000Z
The electrodynamics supplemented with a Lorenz and CPT invariance violating Chern-Simons (CS) action (Carrol-Field-Jackiw electrodynamics) is studied when the parity-odd medium is bounded by a hyperplane separating it from the vacuum. The solutions in both half-spaces are carefully discussed and for space-like boundary stitched on the boundary with help of the Bogolubov transformations. The presence of two different Fock vacua is shown. The passage of photons and massive vector mesons through a boundary between the CS medium and the vacuum of conventional Maxwell electrodynamics is investigated. Effects of reflection from a boundary (up to the total one) are revealed when vector particles escape to vacuum and income from vacuum passing the boundary.
Electroweak baryogenesis in the MSSM with vector-like superfields
Xue Chang; Ran Huo
2014-03-06T23:59:59.000Z
Introducing heavy particles with strong couplings to the Higgs field can strengthen electroweak phase transition, through the entropy release mechanism from both bosons and fermions. We analyze the possibility of electroweak baryogenesis in the MSSM with new vector-like superfields. The new vector-like particles belong to the representation 5+5bar+10+10bar of SU(5). By analyzing in detail the effective potential at finite temperature, we show that a strongly first order electroweak phase transition in this model is ruled out by a combination of 125 GeV Higgs requirement, the bound for exotic quarks, the gluon fusion Higgs production rate and the Higgs diphoton decay rate as well as the electroweak precision measurement.
Observation of ?c1 Decays into Vector Meson Pairs ??, ?? and, ??
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ablikim, M.; Achasov, M. N.; An, L.; An, Q.; An, Z. H.; Bai, J. Z.; Baldini, R.; Ban, Y.; Becker, J.; Berger, N.; Bertani, M.; Bian, J. M.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Cao, G. F.; Cao, X. X.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J. C.; Chen, M. L.; Chen, S. J.; Chen, Y.; Chen, Y. B.; Cheng, H. P.; Chu, Y. P.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J. P.; Dedovich, D.; Deng, Z. Y.; Denysenko, I.; Destefanis, M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Duan, M. Y.; Fan, R. R.; Fang, J.; Fang, S. S.; Feng, C. Q.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Greco, M.; Grishin, S.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A. Q.; Guo, L. B.; Guo, Y. P.; Hao, X. Q.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Heng, Y. K.; Hou, Z. L.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, B.; Huang, G. M.; Huang, J. S.; Huang, X. T.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, X. B.; Ji, X. L.; Jia, L. K.; Jiang, L. L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kavatsyuk, M.; Komamiya, S.; Kuehn, W.; Lange, J. S.; Leung, J. K. C.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H. B.; Li, J. C.; Li, Lei; Li, N. B.; Li, Q. J.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y. T.; Liao, G. R.; Liao, X. T.; Liu, B. J.; Liu, B. J.; Liu, C. L.; Liu, C. X.; Liu, C. Y.; Liu, F. H.; Liu, Fang; Liu, Feng; Liu, G. C.; Liu, H.; Liu, H. B.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K.; Liu, K. Y.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, X. H.; Liu, Y. B.; Liu, Y. W.; Liu, Yong; Liu, Z. A.; Liu, Z. Q.; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J. G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X. L.; Ma, C. L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, T.; Ma, X.; Ma, X. Y.; Maggiora, M.; Malik, Q. A.; Mao, H.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Mitchell, R. E.; Mo, X. H.; Muchnoi, N. Yu.; Nefedov, Y.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Pelizaeus, M.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Pun, C. S. J.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, X. S.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schulze, J.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Sonoda, S.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J. F.; Sun, S. S.; Sun, X. D.; Sun, Y. J.; Sun, Y. Z.; Sun, Z. J.; Sun, Z. T.; Tang, C. J.; Tang, X.; Tang, X. F.; Tian, H. L.; Toth, D.; Varner, G. S.; Wan, X.; Wang, B. Q.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q.; Wang, S. G.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z. Y.; Wei, D. H.; Wen, Q. G.; Wen, S. P.; Wiedner, U.; Wu, L. H.; Wu, N.; Wu, W.; Wu, Z.; Xiao, Z. J.; Xie, Y. G.; Xu, G. F.; Xu, G. M.; Xu, H.; Xu, Y.; Xu, Z. R.; Xu, Z. Z.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, M.; Yang, T.; Yang, Y.; Yang, Y. X.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, L.; Yuan, C. Z.; Yuan, W. L.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, L.; Zhang, S. H.; Zhang, T. R.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, H. S.; Zhao, Jiawei; Zhao, Jingwei; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, S. J.; Zhao, T. C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhao, Z. L.; Zhemchugov, A.; Zheng, B.; Zheng, J. P.; Zheng, Y. H.; Zheng, Z. P.; Zhong, B.; Zhong, J.; Zhong, L.; Zhou, L.; Zhou, X. K.; Zhou, X. R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S. H.; Zhu, X. L.; Zhu, X. W.; Zhu, Y. S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Zuo, J. X.; Zweber, P.
2011-08-01T23:59:59.000Z
Using (106±4)×10? ?(3686) events accumulated with the BESIII detector at the BEPCII e?e? collider, we present the first measurement of decays of ?c1 to vector meson pairs ??, ??, and ??. The branching fractions are measured to be (4.4±0.3±0.5)×10??, (6.0±0.3±0.7)×10??, and (2.2±0.6±0.2)×10??, for ?c1 ???, ??, and ??, respectively, which indicates that the hadron helicity selection rule is significantly violated in ?cJ decays. In addition, the measurement of ?cJ??? provides the first indication of the rate of doubly OZI-suppressed ?cJ decay. Finally, we present improved measurements for the branching fractions of ?c0 and ?c2 to vector meson pairs.
An efficient parallel algorithm for matrix-vector multiplication
Hendrickson, B.; Leland, R.; Plimpton, S.
1993-03-01T23:59:59.000Z
The multiplication of a vector by a matrix is the kernel computation of many algorithms in scientific computation. A fast parallel algorithm for this calculation is therefore necessary if one is to make full use of the new generation of parallel supercomputers. This paper presents a high performance, parallel matrix-vector multiplication algorithm that is particularly well suited to hypercube multiprocessors. For an n x n matrix on p processors, the communication cost of this algorithm is O(n/[radical]p + log(p)), independent of the matrix sparsity pattern. The performance of the algorithm is demonstrated by employing it as the kernel in the well-known NAS conjugate gradient benchmark, where a run time of 6.09 seconds was observed. This is the best published performance on this benchmark achieved to date using a massively parallel supercomputer.
Probability-theoretical analog of the vector Lyapunov function method
Nakonechnyi, A.N.
1995-01-01T23:59:59.000Z
The main ideas of the vector Lyapunov function (VLF) method were advanced in 1962 by Bellman and Matrosov. In this method, a Lyapunov function and a comparison equation are constructed for each subsystem. Then the dependences between the subsystems and the effect of external noise are allowed for by constructing a vector Lyapunov function (as a collection of the scalar Lyapunov functions of the subsystems) and an aggregate comparison function for the entire complex system. A probability-theoretical analog of this method for convergence analysis of stochastic approximation processes has been developed. The abstract approach proposed elsewhere eliminates all restrictions on the system phase space, the system trajectories, the class of Lyapunov functions, etc. The analysis focuses only on the conditions that relate sequences of Lyapunov function values with the derivative and ensure a particular type (mode, character) of stability. In our article, we extend this approach to the VLF method for discrete stochastic dynamic systems.
Non-stationary measurements of Chiral Magnetic Effect
Shevchenko, V.I., E-mail: vladimir.i.shevchenko@gmail.com
2013-12-15T23:59:59.000Z
We discuss the Chiral Magnetic Effect from the quantum theory of measurements point of view for non-stationary measurements. The effect of anisotropy for fluctuations of electric currents in a magnetic field is addressed. It is shown that anisotropy caused by nonzero axial chemical potential is indistinguishable in this framework from anisotropy caused by finite measurement time or finite lifetime of the magnetic field, and in all cases it is related to abelian triangle anomaly. Possible P-odd effects in central heavy-ion collisions (where the Chiral Magnetic Effect is absent) are discussed in this context. This paper is dedicated to the memory of Professor Mikhail Polikarpov (1952–2013). -- Highlights: •Asymmetry in the response function for vector currents of massless fermions in the magnetic field is computed. •Asymmetry caused by axial chemical potential is practically indistinguishable from the one caused by non-stationarity. •The CME current is non-dissipative in the stationary case and dissipative in the non-stationary case. •Importance of studies of P-odd signatures in central collisions is emphasized.
Ballistic dynamics of Dirac particles in electro-magnetic fields
Josef Mehringer; Edgardo Stockmeyer
2014-11-21T23:59:59.000Z
Investigating properties of two-dimensional Dirac operators coupled to an electric and a magnetic field (perpendicular to the plane) requires in general unbounded (vector-) potentials. If the system has a certain symmetry, the fields can be described by one-dimensional potentials $V$ and $A$. Assuming that $|A|<|V|$ outside some arbitrary large ball, we show that absolutely continuous states of the effective Dirac operators spread ballistically. These results are based on well-known methods in spectral dynamics together with certain new Hilbert-Schmidt bounds. We use Lorentz boosts to derive these new estimates.
Magnetic Charge of the Stark States of Hydrogen Atoms
T. Pradhan
2008-09-28T23:59:59.000Z
It is conjectured that Stark states of excited hydrogen atom posses magnetic charge for which the quantum mechanical operator is $${\\cal G}_{op} = {e\\over \\hbar} (\\vec\\sigma\\cdot\\vec A)$$ where $\\vec A$ is the Runge-Lenz vector. The expectation value $g$ of this operator for Stark states is found to be $$ g = e(n_1-n_2)$$ which obeys a Dirac-Saha type quantization formula $${eg\\over c} = (n_1-n_2)\\alpha$$ where $\\alpha$ is the fine structure constant and $n_1$ and $n_2$ are parabolic quantum numbers. An experimental arrangement is outlined to test this conjecture.
Vector Quantization: L'algorithme k-Means Frank NIELSEN
Nielsen, Frank
INF555 TD5 Vector Quantization: L'algorithme k-Means Frank NIELSEN nielsen@lix.polytechnique.fr 13 pixel en un point 3D Â´equivalent (r, g, b) dans l'espace des couleurs. Â· Implanter l'algorithme k-means points 3D des couleurs des pixels et les diffÂ´erentes itÂ´erations de l'algorithme k-means. Â· Utiliser l
Vector Quantization: L'algorithme k-Means Frank NIELSEN
Nielsen, Frank
INF555 TD5 Vector Quantization: L'algorithme k-Means Frank NIELSEN nielsen@lix.polytechnique.fr 12) dans l'espace des couleurs. Â· Implanter l'algorithme k-means pour trouver une table des couleurs couleurs des pixels et les diffÂ´erentes itÂ´erations de l'algorithme k-means. Â· Utiliser l'initialisation de
Search for DM at the LHC using vector boson fusion
Dutta, Bhaskar [Department of Physics and Astronomy, Texas A and M University College Station, TX (United States)
2014-06-24T23:59:59.000Z
The Supersymmetry (SUSY) models are the best candidates to provide a cosmological connection to particle physics. The SUSY particles responsible for satisfying the dark matter content can be observed via cascade decay prcesses from the squarks, gluino productions. However if the squarks, gluinos are heavy, these particles also can be detected via vector boson fusion (VBF) production processes. In this review, I will summarize the search strategies involve VBF which will be very important to establish the cosmological connection.
Methods of treating Parkinson's disease using viral vectors
Bankiewicz, Krys; Cunningham, Janet
2012-11-13T23:59:59.000Z
Methods of delivering viral vectors, particularly recombinant AAV virions, to the central nervous system (CNS) are provided for the treatment of CNS disorders, particularly those disorders which involve the neurotransmitter dopamine. The methods entail providing rAAV virions that comprise a transgene encoding aromatic amino acid decarboxylase (AADC) and administering the virions to the brain of a mammal using a non-manual pump.
Transposon-containing DNA cloning vector and uses thereof
Berg, Claire M. (W. Willington, CT); Berg, Douglas E. (St. Louis, MO); Wang, Gan (Storrs, CT)
1997-01-01T23:59:59.000Z
The present invention discloses a rapid method of restriction mapping, sequencing or localizing genetic features in a segment of deoxyribonucleic acid (DNA) that is up to 42 kb in size. The method in part comprises cloning of the DNA segment in a specialized cloning vector and then isolating nested deletions in either direction in vivo by intramolecular transposition into the cloned DNA. A plasmid has been prepared and disclosed.
Journal of Magnetism and Magnetic Materials 252 (2002) 159161 Magnetically induced alignment of FNS
Reznikov, Yuri
Journal of Magnetism and Magnetic Materials 252 (2002) 159Â161 Magnetically induced alignment the observation of magnetically controlled anchoring of ferro-nematic suspensions. We found that application of a weak magnetic field to a cell with the ferro-suspension induces an easy orientation axis with weak
High Temperature, Permanent Magnet Biased Magnetic Bearings
Gandhi, Varun R.
2010-07-14T23:59:59.000Z
, then the molding process was carried out to form the potting cement on the each stator. After this the stators are baked in the oven and once ready the magnets and back-irons are put onto the stator. Shown below in Figure 3-11 is an assembly tool designed... rings. The bearing and its support rings were then carried onto the test rig and mounted at one end of the table. Throughout the assembly process a lot of care had to be taken so as to avoid damaging of the permanent magnets, stator and its coils...
Magnetic Gas Sensing Using a Dilute Magnetic Semiconductor. ...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Abstract: The authors report on a magnetic gas sensing methodology to detect hydrogen using the ferromagnetic properties of a nanoscale dilute magnetic semiconductor...
Test of OZI violation in vector meson production with COMPASS
Johannes Bernhard; Karin Schönning; for the COMPASS collaboration
2012-03-28T23:59:59.000Z
The COMPASS experiment at CERN SPS completed its data taking with hadron beams (p, \\pi, K) in the years 2008 and 2009 by collecting a large set of data using different targets (H2, Pb, Ni, W). These data are dedicated to hadron spectroscopy, where the focus is directed to the search for exotic bound states of quarks and gluons (hybrids, glueballs). The production of such states is known to be favoured in glue-rich environments, e.g. so-called OZI-forbidden processes. The OZI rule postulates that processes with disconnected quark line diagrams are forbidden. On the one hand, the study of the degree of OZI violation in vector meson production yields the possibility to learn more about the involved production mechanisms. On the other hand it helps to understand the nucleon's structure itself. Contrary to former experiments, the large data sample allows for detailed studies in respect to Feynman's variable xF. We present results from the ongoing analysis on the comparison of \\omega and \\phi vector mesons production in pp->p(\\omega/\\phi)p, where the possibility of measuring the spin alignment of both vector mesons at the same time makes COMPASS unique.
Axial-vector coupling constants and chiral-symmetry restoration
Henley, E.M. (Department of Physics FM-15 and Institute for Nuclear Theory HN-12, University of Washington, Seattle, Washington 98195 (United States)); Hwang, W.P. (Department of Physics, National Taiwan University, Taipei, Taiwan 10764 (Taiwan, Province of China)); Kisslinger, L.S. (Department of Physics, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213 (United States))
1992-07-01T23:59:59.000Z
The isovector axial-vector coupling constant {ital g}{sub {ital A}} is determined by using the method of QCD sum rules. A sum rule for ({ital g}{sub {ital A}}{minus}1) is obtained, and it is shown that, with standard values of the quark condensates, {ital g}{sub {ital A}}=1.26{plus minus}0.08. It is also shown that the isovector axial-vector coupling ({ital g}{sub {ital A}}{minus}1)=0 in the limit in which chiral symmetry is restored, and the quark condensate vanishes. A sum rule is also obtained for the isoscalar'' axial-vector coupling constant {ital g}{sub {ital A}}{sup {ital S}}, which is found to be 0.13 if the isovector values of susceptibilities are used. On the other hand, {ital g}{sub {ital A}}{sup {ital S}}={minus}0.68 if the quark condensate is set to zero while {ital g}{sub {ital A}}{sup {ital S}}={minus}1.00 if both the quark and gluon condensates vanish in the event of chiral-symmetry restoration. The values of {ital g}{sub {ital A}} and {ital g}{sub {ital A}}{sup {ital S}} allow us to deduce {Delta}{ital u} and {Delta}{ital d} in the proton.
Superconducting Magnet Division
Ohta, Shigemi
Superconducting Magnet Division MAGNETIC DESIGN OF E-LENS SOLENOID AND CORRECTOR SYSTEM FOR RHIC* R.6 A gun collectors gun Combined Horizontal and Vertical Corrector Design Both types of dipole correctors. Gupta, M. Anerella, W. Fischer, G. Ganetis, X. Gu, A. Ghosh, A. Jain, P. Kovach, A. Marone, S. Plate, A
Passive magnetic bearing configurations
Post, Richard F. (Walnut Creek, CA)
2011-01-25T23:59:59.000Z
A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.
Active Magnetic Regenerator Experimental Optimization
Victoria, University of
the potential to create more efficient and compact refrigeration devices is an Active Magnetic Regenerative temperature refrigerators, as well as efficient gas liquefaction plants (AMRLs). Active Magnetic Regenerator Refrigeration exploits the magnetocaloric effect displayed by magnetic materials whereby a reversible
R. Y. Chiao
2012-06-23T23:59:59.000Z
The flux as measured by the Josephson effect in a SQUID-like configuration with a ferromagnetic core inserted into its center, is shown to be sensitive to the vector potential arising from the central ferromagnetic core, even when the core is covered with a superconducting material that prevents any magnetic field lines from ever reaching the perimeter of the SQUID-like configuration. This leads to a macroscopic, Aharonov-Bohm-like effect that is observable in an asymmetric hysteresis loop in the response of the SQUID-like configuration to an externally applied magnetic field.
El-Refaie, Ayman M [ORNL; Jahns, Thomas M [ORNL; Reddy, Patel [University of Wisconsin; McKeever, John W [ORNL
2008-01-01T23:59:59.000Z
This paper presents a modified vector control algorithm for a fractional-slot concentrated-winding surface permanent magnet (SPM) machine that has been developed to maximize the machine's partial-load efficiency over a wide range of operating conditions. By increasing the amplitude of the negative d-axis current, the resulting increase in the stator copper losses can be more than offset by the reduction in the iron core losses achieved by lowering the stator d-axis flux amplitude. The effectiveness of this technique has been demonstrated using both analytical models and finite element analysis for a 55-kW (peak) SPM machine design developed for a demanding set of traction drive performance requirements. For this example, the modified control strategy increases the partial-load efficiency at 20% of rated torque by > 6% at 2000 r/min compared to the maximum torque/ampere algorithm, making the machine much more attractive for its intended application.
Review and comparison of magnet designs for magnetic refrigeration
Bjørk, R; Smith, A; Pryds, N
2014-01-01T23:59:59.000Z
One of the key issues in magnetic refrigeration is generating the magnetic field that the magnetocaloric material must be subjected to. The magnet constitutes a major part of the expense of a complete magnetic refrigeration system and a large effort should therefore be invested in improving the magnet design. A detailed analysis of the efficiency of different published permanent magnet designs used in magnetic refrigeration applications is presented in this paper. Each design is analyzed based on the generated magnetic flux density, the volume of the region where this flux is generated and the amount of magnet material used. This is done by characterizing each design by a figure of merit magnet design efficiency parameter, $\\Lambda_\\mathrm{cool}$. The designs are then compared and the best design found. Finally recommendations for designing the ideal magnet design are presented based on the analysis of the reviewed designs.
Condensed Matter and Magnet Science
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
and HC) Suite of nondestructive pulsed magnets up to 100 tesla Thermoacoustics and fluid dynamics Transport, magnetism, and thermodynamic characterization at extreme conditions of...
QUENCHES IN LARGE SUPERCONDUCTING MAGNETS
Eberhard, P.H.
2010-01-01T23:59:59.000Z
QUENCHES IN LARGE SUPERCONDUCTING MAGNETS. P. H. Eberhard,Study of an Unprotected Superconducting Coil Going Normal,"Method for Testing Superconducting Magnets," LBL Physics
Large Magnetization at Carbon Surfaces
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Large Magnetization at Carbon Surfaces Large Magnetization at Carbon Surfaces Print Wednesday, 31 August 2011 00:00 From organic matter to pencil lead, carbon is a versatile...
Bernard Jancewicz
1998-07-17T23:59:59.000Z
We present pictorial means of distinguishing contravariant vectors (or simply vectors) from covariant vectors (or linear forms). When one depicts vector as the directed segment, then the pictorial image of a linear form is a family of equidistant parallel planes with an arrow joining the neighbouring planes and showing the direction of increase of the form. First of these planes is the linear subspace of dimension two on which the linear form gives value zero. Several examples of physical quantities are given which are naturally vectors, and others which are naturally linear forms.
Journal of Magnetism and Magnetic Materials ] (
Schumann, Rolf
width of internal field fluctuations. For the ``normal'' TR of the metallic magnets SmCo5; Sm2Co17 of the parameters for SmCo5 and barium ferrite. Susceptibility measurements with small alternating fields, carried out at different points of the TR curve, as well as repeating TR-experiments at SmCo5 demonstrate
Collective Modes of Chiral Kinetic Theory in Magnetic Field
Mikhail Stephanov; Ho-Ung Yee; Yi Yin
2014-12-31T23:59:59.000Z
We study collective excitations in systems described by chiral kinetic theory in external magnetic field. We consider high-temperature weak-coupling plasma, as well as high-density Landau Fermi liquid with interaction not restricted to be weak. We show that chiral magnetic wave (CMW) emerges in hydrodynamic regime (at frequencies smaller than collision relaxation rate) and the CMW velocity is determined by thermodynamic properties only. We find that in a plasma of opposite chiralities, at frequencies smaller than the chirality-flipping rate, the CMW excitation turns into a vector-like diffusion mode. In the interacting Fermi liquid, the CMW turns into the Landau zero sound mode in the high-frequency collisionless regime.
Collective Modes of Chiral Kinetic Theory in Magnetic Field
Stephanov, Mikhail; Yin, Yi
2015-01-01T23:59:59.000Z
We study collective excitations in systems described by chiral kinetic theory in external magnetic field. We consider high-temperature weak-coupling plasma, as well as high-density Landau Fermi liquid with interaction not restricted to be weak. We show that chiral magnetic wave (CMW) emerges in hydrodynamic regime (at frequencies smaller than collision relaxation rate) and the CMW velocity is determined by thermodynamic properties only. We find that in a plasma of opposite chiralities, at frequencies smaller than the chirality-flipping rate, the CMW excitation turns into a vector-like diffusion mode. In the interacting Fermi liquid, the CMW turns into the Landau zero sound mode in the high-frequency collisionless regime.
Screening magnetic fields by superconductors: A simple model
Caputo, J.-G., E-mail: caputo@insa-rouen.fr [Laboratoire de Mathématiques, INSA de Rouen, Avenue de l'Université, 76801 Saint-Etienne du Rouvray (France); Gozzelino, L.; Laviano, F.; Ghigo, G.; Gerbaldo, R. [Department of Applied Science and Technology, Politecnico di Torino, 10129, Torino (Italy); Noudem, J.; Thimont, Y.; Bernstein, P. [CRISMAT/LUSAC, Physics Department, Université de Caen (France)
2013-12-21T23:59:59.000Z
We introduce a simple approach to evaluate the magnetic field distribution around superconducting samples, based on the London equations; the elementary variable is the vector potential. This procedure has no adjustable parameters, only the sample geometry and the London length, ?, determine the solution. This approach was validated by comparing the induction field calculated to the one measured above MgB{sub 2} disks of different diameters, at 20?K and for applied fields lower than 0.4?T. The model can be applied if the flux line penetration inside the sample can be neglected when calculating the induction field distribution outside the superconductor. We conclude by showing on a cup-shape geometry how one can design a magnetic shield satisfying a specific constraint.
Emergence of Small-Scale Magnetic Loops in the Quiet Sun Internetwork
R. Centeno; H. Socas-Navarro; B. Lites; M. Kubo; Z. Frank; R. Shine; T. Tarbell; A. Title; K. Ichimoto; S. Tsuneta; Y. Katsukawa; Y. Suematsu; T. Shimizu; S. Nagata
2007-08-06T23:59:59.000Z
We study the emergence of magnetic flux at very small spatial scales (less than 2 arcsec) in the quiet Sun internetwork. To this aim, a time series of spectropolarimetric maps was taken at disk center using the instrument SP/SOT on board Hinode. The LTE inversion of the full Stokes vector measured in the Fe I 6301 and 6302 A lines allows us to retrieve the magnetic flux and topology in the region of study. In the example presented here, the magnetic flux emerges within a granular structure. The horizontal magnetic field appears prior to any significant amount of vertical field. As time goes on, the traces of the horizontal field disappear while the the vertical dipoles drift -carried by the plasma motions- towards the surrounding intergranular lanes. These events take place within typical granulation timescales.
Permanent magnet energy conversion machine with magnet mounting arrangement
Hsu, John S. (Oak Ridge, TN); Adams, Donald J. (Knoxville, TN)
1999-01-01T23:59:59.000Z
A hybrid permanent magnet dc motor includes three sets of permanent magnets supported by the rotor and three sets of corresponding stators fastened to the surrounding frame. One set of magnets operates across a radial gap with a surrounding radial gap stator, and the other two sets of magnets operate off the respective ends of the rotor across respective axial gaps.
Magnetic Resonance Imaging System Based on Earth's Magnetic Field
Stepi?nik, Janez
Magnetic Resonance Imaging System Based on Earth's Magnetic Field Ales Mohoric,1,* Gorazd Planinsic magnetic field can be partly compensated by the receiving coil design and shielding of electromagnetic pick and must be monitored accurately.[8 10] The importance of NMR in a non-uniform magnetic field
Bonanos, Peter (East Brunswick, NJ)
1983-01-01T23:59:59.000Z
A toroidal magnet for confining a high magnetic field for use in fusion reactor research and nuclear particle detection. The magnet includes a series of conductor elements arranged about and fixed at its small major radius portion to the outer surface of a central cylindrical support each conductor element having a geometry such as to maintain the conductor elements in pure tension when a high current flows therein, and a support assembly which redistributes all or part of the tension which would otherwise arise in the small major radius portion of each coil element to the large major radius portion thereof.
Sasmal, Sudip; Nayak, Malaya K; Vaval, Nayana; Pal, Sourav
2015-01-01T23:59:59.000Z
The molecular dipole moment and magnetic hyperfine structure constant demand an accurate wavefunction far from the nucleus and in near nuclear region, respectively. We, therefore, employ the so-called Z-vector method in the domain of relativistic coupled cluster theory to calculate the first order property of molecular systems in their open-shell ground state configuration. The implemented method is applied to calculate molecular dipole moment and parallel component of the magnetic hyperfine structure constant of SrF molecule. The results of our calculation are compared with the experimental and other available theoretically calculated values. We are successful in achieving good accordance with the experimental results. The result of our calculation of molecular dipole moment is in the accuracy of ~? 0.5 %, which is clearly an improvement over the previous calculation based on the expectation value method in the four component coupled cluster framework [V. S. Prasannaa et al, Phys. Rev. A 90, 052507 (2014)] a...
Skobelev, V. V., E-mail: v.skobelev@inbox.ru [Moscow State Industrial University (Russian Federation)
2011-04-15T23:59:59.000Z
The absence of divergences and singularities in effectively two-dimensional field theory induced by a superstrong magnetic field is demonstrated for the example where loop diagrams involving two vector and two pseudovector vertices are calculated. The form of effective low-energy Lagrangians for ({gamma}{nu}{nu}) and (a{nu}{nu}) interactions in a superstrong magnetic field is presented. The role of photon and axion decays to neutrinos in the early universe is discussed.
Thierry-Mieg, J
2006-01-01T23:59:59.000Z
In Yang-Mills theory, the charges of the left and right massless Fermions are independent of each other. We propose a new paradigm where we remove this freedom and densify the algebraic structure of Yang-Mills theory by integrating the scalar Higgs field into a new gauge-chiral 1-form which connects Fermions of opposite chiralities. Using the Biancchi identity, we prove that the corresponding covariant differential is associative if and only if we gauge a Lie-Kac super-algebra. In this model, spontaneous symmetry breakdown naturally occurs along an odd generator of the super-algebra and induces a representation of the Connes-Lott non commutative differential geometry of the 2-point finite space.
Hofmann, M. [Naturwissenschaftlich-Technische Fakultät, Universität Siegen, Walter-Flex-Str. 3, 57068 Siegen (Germany)] [Naturwissenschaftlich-Technische Fakultät, Universität Siegen, Walter-Flex-Str. 3, 57068 Siegen (Germany); Rudolph, G.; Schmidt, M. [Institut für Theoretische Physik, Universität Leipzig, Augustusplatz 10/11, 04109 Leipzig (Germany)] [Institut für Theoretische Physik, Universität Leipzig, Augustusplatz 10/11, 04109 Leipzig (Germany)
2013-08-15T23:59:59.000Z
We consider a system with symmetries whose configuration space is a compact Lie group, acted upon by inner automorphisms. The classical reduced phase space of this system decomposes into connected components of orbit type subsets. To investigate hypothetical quantum effects of this decomposition one has to construct the associated costratification of the Hilbert space of the quantum system in the sense of Huebschmann. In the present paper, instead of the decomposition by orbit types, we consider the related decomposition by reflection types (conjugacy classes of reflection subgroups). These two decompositions turn out to coincide, e.g., for the classical groups SU(n) and Sp(n). We derive defining relations for reflection type subsets in terms of irreducible characters and discuss how to obtain from that the corresponding costratification of the Hilbert space of the system. To illustrate the method, we give explicit results for some low rank classical groups.
J. Terasaki; J. Engel
2011-05-19T23:59:59.000Z
Although nuclear energy density functionals are determined primarily by fitting to ground state properties, they are often applied in nuclear astrophysics to excited states, usually through the quasiparticle random phase approximation (QRPA). Here we test the Skyrme functionals SkM* and SLy4 along with the self-consistent QRPA by calculating properties of low-lying vibrational states in a large number of well-deformed even-even rare-earth nuclei. We reproduce trends in energies and transition probabilities associated with gamma-vibrational states, but our results are not perfect and indicate the presences of multi-particle-hole correlations that are not included in the QRPA. The Skyrme functional SkM* performs noticeably better than SLy4. In a few nuclei, changes in the treatment of the pairing energy functional have a significant effect. The QRPA is less successful with "beta-vibrational" states than with the gamma-vibrational states.
MAGNETIC NONPOTENTIALITY IN PHOTOSPHERIC ACTIVE REGIONS AS A PREDICTOR OF SOLAR FLARES
Yang Xiao; Lin Ganghua; Zhang Hongqi; Mao Xinjie, E-mail: yangx@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Beijing 100012 (China)
2013-09-10T23:59:59.000Z
Based on several magnetic nonpotentiality parameters obtained from the vector photospheric active region magnetograms obtained with the Solar Magnetic Field Telescope at the Huairou Solar Observing Station over two solar cycles, a machine learning model has been constructed to predict the occurrence of flares in the corresponding active region within a certain time window. The Support Vector Classifier, a widely used general classifier, is applied to build and test the prediction models. Several classical verification measures are adopted to assess the quality of the predictions. We investigate different flare levels within various time windows, and thus it is possible to estimate the rough classes and erupting times of flares for particular active regions. Several combinations of predictors have been tested in the experiments. The True Skill Statistics are higher than 0.36 in 97% of cases and the Heidke Skill Scores range from 0.23 to 0.48. The predictors derived from longitudinal magnetic fields do perform well, however, they are less sensitive in predicting large flares. Employing the nonpotentiality predictors from vector fields improves the performance of predicting large flares of magnitude {>=}M5.0 and {>=}X1.0.
Modular tokamak magnetic system
Yang, Tien-Fang (Wayland, MA)
1988-01-01T23:59:59.000Z
A modular tokamak system comprised of a plurality of interlocking moldules. Each module is comprised of a vacuum vessel section, a toroidal field coil, moldular saddle coils which generate a poloidal magnetic field and ohmic heating coils.
Geometrically frustrated quantum magnets
NikoliÄ‡ , Predrag, 1974-
2004-01-01T23:59:59.000Z
(cont.) more general lessons on frustrated quantum magnetism. At the end, we demonstrate some new mathematical tools on two other frustrated two-dimensional systems, and summarize our conclusions, with an outlook to remaining ...
Makarov, Sergey V; Krasnok, Alexander E; Belov, Pavel A
2015-01-01T23:59:59.000Z
We propose a novel concept for efficient dynamic tuning of optical properties of a high refractive index subwavelength nanoparticle with a magnetic Mie-type resonance by means of femtosecond laser radiation. This concept is based on ultrafast generation of electron-hole plasma within such nanoparticle, drastically changing its transient dielectric permittivity. This allows to manipulate by both electric and magnetic nanoparticle responses, resulting in dramatic changes of its extinction cross section and scattering diagram. Specifically, we demonstrate the effect of ultrafast switching-on a Huygens source in the vicinity of the magnetic dipole resonance. This approach enables to design ultrafast and compact optical switchers and modulators based on the "ultrafast magnetic light" concept.
Meyer, Ross E. (Los Alamos, NM)
1993-01-01T23:59:59.000Z
A climbing apparatus is provided for climbing ferromagnetic surfaces, such as storage tanks and steel frame structures. A magnet assembly is rotatably mounted in a frame assembly. The frame assembly provides a pair of cam surfaces having different dimensions so that, when the frame is rotated, the cam surfaces contact the ferromagnetic surface to separate the magnet assembly from the surface. The different cam dimensions enable one side of the magnet at a time to be detached from the surface to reduce the effort needed to disengage the climbing apparatus. The cam surface also provides for smoothly attaching the apparatus. A hardened dowel pin is also attached to the frame and the pointed end of the dowel engages the surface when the magnet is attached to the surface to prevent downward sliding movement of the assembly under the weight of the user.
Meyer, R.E.
1993-03-09T23:59:59.000Z
A climbing apparatus is provided for climbing ferromagnetic surfaces, such as storage tanks and steel frame structures. A magnet assembly is rotatably mounted in a frame assembly. The frame assembly provides a pair of cam surfaces having different dimensions so that, when the frame is rotated, the cam surfaces contact the ferromagnetic surface to separate the magnet assembly from the surface. The different cam dimensions enable one side of the magnet at a time to be detached from the surface to reduce the effort needed to disengage the climbing apparatus. The cam surface also provides for smoothly attaching the apparatus. A hardened dowel pin is also attached to the frame and the pointed end of the dowel engages the surface when the magnet is attached to the surface to prevent downward sliding movement of the assembly under the weight of the user.
2T Physics, Scale Invariance and Topological Vector Fields
W. Chagas-Filho
2007-11-22T23:59:59.000Z
We construct, in classical two-time physics, the necessary structure for the most general configuration space formulation of quantum mechanics containing gravity in d+2 dimensions. This structure is composed of a symmetric Riemannian metric tensor and of a vector field that defines a section of a flat U(1) bundle over space-time. This construction is possible because of the existence of a finite local scale invariance of the Hamiltonian and because two-time physics contains, at the classical level, a local generalization of the discrete duality symmetry between position and momentum that underlies the structure of quantum mechanics.
Fusion in coset CFT from admissible singular-vector decoupling
P. Mathieu; J. Rasmussen; M. A. Walton
2000-07-11T23:59:59.000Z
Fusion rules for Wess-Zumino-Witten (WZW) models at fractional level can be defined in two ways, with distinct results. The Verlinde formula yields fusion coefficients that can be negative. These signs cancel in coset fusion rules, however. On the other hand, the fusion coefficients calculated from decoupling of singular vectors are non-negative. They produce incorrect coset fusion rules, however, when factorisation is assumed. Here we give two prescriptions that yield the correct coset fusion rules from those found for the WZW models by the decoupling method. We restrict to the Virasoro minimal models for simplicity, and because decoupling results are only complete in the $\\su(2)$ case.
Characteristic Lyapunov vectors in chaotic time-delayed systems
Diego Pazó; Juan M. López
2011-01-14T23:59:59.000Z
We compute Lyapunov vectors (LVs) corresponding to the largest Lyapunov exponents in delay-differential equations with large time delay. We find that characteristic LVs, and backward (Gram-Schmidt) LVs, exhibit long-range correlations, identical to those already observed in dissipative extended systems. In addition we give numerical and theoretical support to the hypothesis that the main LV belongs, under a suitable transformation, to the universality class of the Kardar-Parisi-Zhang equation. These facts indicate that in the large delay limit (an important class of) delayed equations behave exactly as dissipative systems with spatiotemporal chaos.
Magnetic susceptibility, magnetization, magnetic moment and characterization of Carancas meteorite
Rosales, Domingo
2015-01-01T23:59:59.000Z
On September, 15th, 2007, in the community of Carancas (Puno, Peru) a stony meteorite formed a crater explosive type with a mean diameter of 13.5 m. some samples meteorite fragments were collected. The petrologic analysis performed corresponds to a meteorite ordinary chondrite H 4-5. In this paper we have analyzed the magnetic properties of a meteorite fragment with a proton magnetometer. Also in order to have a complete characterization of the Carancas meteorite and its crater, from several papers, articles and reports, we have made a compilation of the most important characteristics and properties of this meteorite.
Permanent Magnet Ecr Plasma Source With Magnetic Field Optimization
Doughty, Frank C. (Plano, TX); Spencer, John E. (Plano, TX)
2000-12-19T23:59:59.000Z
In a plasma-producing device, an optimized magnet field for electron cyclotron resonance plasma generation is provided by a shaped pole piece. The shaped pole piece adjusts spacing between the magnet and the resonance zone, creates a convex or concave resonance zone, and decreases stray fields between the resonance zone and the workpiece. For a cylindrical permanent magnet, the pole piece includes a disk adjacent the magnet together with an annular cylindrical sidewall structure axially aligned with the magnet and extending from the base around the permanent magnet. The pole piece directs magnetic field lines into the resonance zone, moving the resonance zone further from the face of the magnet. Additional permanent magnets or magnet arrays may be utilized to control field contours on a local scale. Rather than a permeable material, the sidewall structure may be composed of an annular cylindrical magnetic material having a polarity opposite that of the permanent magnet, creating convex regions in the resonance zone. An annular disk-shaped recurve section at the end of the sidewall structure forms magnetic mirrors keeping the plasma off the pole piece. A recurve section composed of magnetic material having a radial polarity forms convex regions and/or magnetic mirrors within the resonance zone.
Nance, Thomas A. (Aiken, SC)
2009-08-18T23:59:59.000Z
A quick connect/disconnect coupling apparatus is provided in which a base member is engaged by a locking housing through a series of interengagement pins. The pins maintain the shaft in a locked position. Upon exposure to an appropriately positioned magnetic field, pins are removed a sufficient distance such that the shaft may be withdrawn from the locking housing. The ability to lock and unlock the connector assembly requires no additional tools or parts apart from a magnetic key.
Berman, S.M.; Richardson R.W.
1983-12-29T23:59:59.000Z
The radiant emission of a mercury-argon discharge in a fluorescent lamp assembly is enhanced by providing means for establishing a magnetic field with lines of force along the path of electron flow through the bulb of the lamp assembly, to provide Zeeman splitting of the ultraviolet spectral line. Optimum results are obtained when the magnetic field strength causes a Zeeman splitting of approximately 1.7 times the thermal line width.
Freely oriented portable superconducting magnet
Schmierer, Eric N. (Los Alamos, NM); Prenger, F. Coyne (Los Alamos, NM); Hill, Dallas D. (Los Alamos, NM)
2010-01-12T23:59:59.000Z
A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.
Hood, R.Q.
1994-04-01T23:59:59.000Z
Utilizing self-consistent Hartree-Fock calculations, several aspects of multilayers and interfaces are explored: enhancement and reduction of the local magnetic moments, magnetic coupling at the interfaces, magnetic arrangements within each film and among non-neighboring films, global symmetry of the systems, frustration, orientation of the various moments with respect to an outside applied field, and magnetic-field induced transitions. Magnetoresistance of ferromagnetic-normal-metal multilayers is found by solving the Boltzmann equation. Results explain the giant negative magnetoresistance encountered in these systems when an initial antiparallel arrangement is changed into a parallel configuration by an external magnetic field. The calculation depends on (1) geometric parameters (thicknesses of layers), (2) intrinsic metal parameters (number of conduction electrons, magnetization, and effective masses in layers), (3) bulk sample properties (conductivity relaxation times), (4) interface scattering properties (diffuse scattering versus potential scattering at the interfaces, and (5) outer surface scattering properties (specular versus diffuse surface scattering). It is found that a large negative magnetoresistance requires considerable asymmetry in interface scattering for the two spin orientations. Features of the interfaces that may produce an asymmetrical spin-dependent scattering are studied: varying interfacial geometric random roughness with no lateral coherence, correlated (quasi-periodic) roughness, and varying chemical composition of the interfaces. The interplay between these aspects of the interfaces may enhance or suppress the magnetoresistance, depending on whether it increases or decreases the asymmetry in the spin-dependent scattering of the conduction electrons.
Exact Rotating Magnetic Traversable Wormholes satisfying the Energy Conditions
Matos, Tonatiuh
2015-01-01T23:59:59.000Z
In this work we wonder if there is a way to generate a wormhole (WH) in nature using "normal" matter. In order to give a first answer to this question, we study a massless scalar field coupled to an electromagnetic one (dilatonic field) with an arbitrary coupling constant, as source of gravitation. We obtain an exact solution of the Einstein equations using this source that represents a magnetized rotating WH. This space-time has a naked ring singularity, probably untouchable as in \\cite{Matos:2012gj}, but otherwise regular. The WH throat lies on the disc bounded by the ring singularity, which keeps the throat open without requiring exotic matter, that means, satisfying all the energy conditions. After analyzing the geodesic motion and the tidal forces we find that a test particle can go through the WH without troubles.
Real-time individualized training vectors for experiential learning.
Willis, Matt; Tucker, Eilish Marie; Raybourn, Elaine Marie; Glickman, Matthew R.; Fabian, Nathan
2011-01-01T23:59:59.000Z
Military training utilizing serious games or virtual worlds potentially generate data that can be mined to better understand how trainees learn in experiential exercises. Few data mining approaches for deployed military training games exist. Opportunities exist to collect and analyze these data, as well as to construct a full-history learner model. Outcomes discussed in the present document include results from a quasi-experimental research study on military game-based experiential learning, the deployment of an online game for training evidence collection, and results from a proof-of-concept pilot study on the development of individualized training vectors. This Lab Directed Research & Development (LDRD) project leveraged products within projects, such as Titan (Network Grand Challenge), Real-Time Feedback and Evaluation System, (America's Army Adaptive Thinking and Leadership, DARWARS Ambush! NK), and Dynamic Bayesian Networks to investigate whether machine learning capabilities could perform real-time, in-game similarity vectors of learner performance, toward adaptation of content delivery, and quantitative measurement of experiential learning.
Combined dispersive/interference spectroscopy for producing a vector spectrum
Erskine, David J. (Oakland, CA)
2002-01-01T23:59:59.000Z
A method of measuring the spectral properties of broadband waves that combines interferometry with a wavelength disperser having many spectral channels to produce a fringing spectrum. Spectral mapping, Doppler shifts, metrology of angles, distances and secondary effects such as temperature, pressure, and acceleration which change an interferometer cavity length can be measured accurately by a compact instrument using broadband illumination. Broadband illumination avoids the fringe skip ambiguities of monochromatic waves. The interferometer provides arbitrarily high spectral resolution, simple instrument response, compactness, low cost, high field of view and high efficiency. The inclusion of a disperser increases fringe visibility and signal to noise ratio over an interferometer used alone for broadband waves. The fringing spectrum is represented as a wavelength dependent 2-d vector, which describes the fringe amplitude and phase. Vector mathematics such as generalized dot products rapidly computes average broadband phase shifts to high accuracy. A Moire effect between the interferometer's sinusoidal transmission and the illumination heterodynes high resolution spectral detail to low spectral detail, allowing the use of a low resolution disperser. Multiple parallel interferometer cavities of fixed delay allow the instantaneous mapping of a spectrum, with an instrument more compact for the same spectral resolution than a conventional dispersive spectrometer, and not requiring a scanning delay.
Bootstrapping $O(N)$ Vector Models in $4
Shai M. Chester; Silviu S. Pufu; Ran Yacoby
2015-01-06T23:59:59.000Z
We use the conformal bootstrap to study conformal field theories with $O(N)$ global symmetry in $d=5$ and $d=5.95$ spacetime dimensions that have a scalar operator $\\phi_i$ transforming as an $O(N)$ vector. The crossing symmetry of the four-point function of this $O(N)$ vector operator, along with unitarity assumptions, determine constraints on the scaling dimensions of conformal primary operators in the $\\phi_i \\times \\phi_j$ OPE. Imposing a lower bound on the second smallest scaling dimension of such an $O(N)$-singlet conformal primary, and varying the scaling dimension of the lowest one, we obtain an allowed region that exhibits a kink located very close to the interacting $O(N)$-symmetric CFT conjectured to exist recently by Fei, Giombi, and Klebanov. Under reasonable assumptions on the dimension of the second lowest $O(N)$ singlet in the $\\phi_i \\times \\phi_j$ OPE, we observe that this kink disappears in $d =5$ for small enough $N$, suggesting that in this case an interacting $O(N)$ CFT may cease to exist for $N$ below a certain critical value.
Couples Magnetic and Structural Transitions in High-Purity Dy and Gd5SbxGe4-x
Alexander S. Chernyshov
2006-08-09T23:59:59.000Z
Magnetic materials exhibiting magnetic phase transitions simultaneously with structural rearrangements of their crystal lattices hold a promise for numerous applications including magnetic refrigeration, magnetomechanical devices and sensors. We undertook a detailed study of a single crystal of dysprosium metal, which is a classical example of a system where magnetic and crystallographic sublattices can be either coupled or decoupled from one another. Magnetocaloric effect, magnetization, ac magnetic susceptibility, and heat capacity of high purity single crystals of dysprosium have been investigated over broad temperature and magnetic field intervals with the magnetic field vector parallel to either the a- or c-axes of the crystal. Notable differences in the behavior of the physical properties when compared to Dy samples studied in the past have been observed between 110 K and 125 K, and between 178 K and {approx}210 K. A plausible mechanism based on the formation of antiferromagnetic clusters in the impure Dy has been suggested in order to explain the reduction of the magnetocaloric effect in the vicinity of the Neel point. Experimental and theoretical investigations of the influence of commensurability effects on the magnetic phase diagram and the value of the magnetocaloric effect have been conducted. The presence of newly found anomalies in the physical properties has been considered as evidence of previously unreported states of Dy. The refined magnetic phase diagram of dysprosium with the magnetic field vector parallel to the a-axis of a crystal has been constructed and discussed. The magnetic and crystallographic properties of Gd{sub 5}Sb{sub x}Ge{sub 4-x} pseudo-binary system were studied by x-ray diffraction (at room temperature), heat capacity, ac-magnetic susceptibility, and magnetization in the temperature interval 5-320 K in magnetic fields up to 100 kOe. The magnetic properties of three composition (x = 0.5, 1,2) were examined in detail. The Gd{sub 5}Sb{sub 2}Ge{sub 2} compound that adopts Tm{sub 5}Sb{sub 2}Si{sub 2}-type of structure (space group is Cmca), shows a second order FM-PM transition at 200 K, whereas Gd{sub 5}Sb{sub x}Ge{sub 4-x} compounds for x = 0.5 and x = 1 (Sm{sub 5}Ge{sub 4}-type of structure, space group is Pnma) exhibit first order phase transformations at 45 K and 37 K, respectively.
Five-Dimensional Tangent Vectors in Space-Time: IV. Generalization of Exterior Calculus
Alexander Krasulin
1998-08-18T23:59:59.000Z
This part of the series is devoted to the generalization of exterior differential calculus. I give definition to the integral of a five-vector form over a limited space-time volume of appropriate dimension; extend the notion of the exterior derivative to the case of five-vector forms; and formulate the corresponding analogs of the generalized Stokes theorem and of the Poincare theorem about closed forms. I then consider the five-vector generalization of the exterior derivative itself; prove a statement similar to the Poincare theorem; define the corresponding five-vector generalization of flux; and derive the analog of the formula for integration by parts. I illustrate the ideas developed in this paper by reformulating the Lagrange formalism for classical scalar fields in terms of five-vector forms. In conclusion, I briefly discuss the five-vector analog of the Levi-Civita tensor and dual forms.
Ellis, Sebastian A R; Gopalakrishna, Shrihari; Wells, James D
2014-01-01T23:59:59.000Z
With the renewed interest in vector-like fermion extensions of the Standard Model, we present here a study of multiple vector-like theories and their phenomenological implications. Our focus is mostly on minimal flavor conserving theories that couple the vector-like fermions to the SM gauge fields and mix only weakly with SM fermions so as to avoid flavor problems. We present calculations for precision electroweak and vector-like state decays, which are needed to investigate compatibility with currently known data. We investigate the impact of vector-like fermions on Higgs boson production and decay, including loop contributions, in a wide variety of vector-like extensions and their parameter spaces.
Thomas Wiegelmann; Bernd Inhester; Bernhard Kliem; Gherardo Valori; Thomas Neukirch
2006-12-21T23:59:59.000Z
CONTEXT: As the coronal magnetic field can usually not be measured directly, it has to be extrapolated from photospheric measurements into the corona. AIMS: We test the quality of a non-linear force-free coronal magnetic field extrapolation code with the help of a known analytical solution. METHODS: The non-linear force-free equations are numerically solved with the help of an optimization principle. The method minimizes an integral over the force-free and solenoidal condition. As boundary condition we use either the magnetic field components on all six sides of the computational box in Case I or only on the bottom boundary in Case II. We check the quality of the reconstruction by computing how well force-freeness and divergence-freeness are fulfilled and by comparing the numerical solution with the analytical solution. The comparison is done with magnetic field line plots and several quantitative measures, like the vector correlation, Cauchy Schwarz, normalized vector error, mean vector error and magnetic energy. RESULTS: For Case I the reconstructed magnetic field shows good agreement with the original magnetic field topology, whereas in Case II there are considerable deviations from the exact solution. This is corroborated by the quantitative measures, which are significantly better for Case I. CONCLUSIONS: Despite the strong nonlinearity of the considered force-free equilibrium, the optimization method of extrapolation is able to reconstruct it; however, the quality of reconstruction depends significantly on the consistency of the input data, which is given only if the known solution is provided also at the lateral and top boundaries, and on the presence or absence of flux concentrations near the boundaries of the magnetogram.
Magnetic monopole and the nature of the static magnetic field
Xiuqing Huang
2008-12-10T23:59:59.000Z
We investigate the factuality of the hypothetical magnetic monopole and the nature of the static magnetic field. It is shown from many aspects that the concept of the massive magnetic monopoles clearly is physically untrue. We argue that the static magnetic field of a bar magnet, in fact, is the static electric field of the periodically quasi-one-dimensional electric-dipole superlattice, which can be well established in some transition metals with the localized d-electron. This research may shed light on the perfect unification of magnetic and electrical phenomena.
N. I. Stoilova; J. Van der Jeugt
2010-04-14T23:59:59.000Z
A Gel'fand-Zetlin basis is introduced for the irreducible covariant tensor representations of the Lie superalgebra gl(m|n). Explicit expressions for the generators of the Lie superalgebra acting on this basis are determined. Furthermore, Clebsch-Gordan coefficients corresponding to the tensor product of any covariant tensor representation of gl(m|n) with the natural representation V ([1,0,...,0]) of gl(m|n) with highest weight (1,0,. . . ,0) are computed. Both results are steps for the explicit construction of the parastatistics Fock space.
Jose M. Pacheco
2007-01-21T23:59:59.000Z
Often some interesting or simply curious points are left out when developing a theory. It seems that one of them is the existence of an upper bound for the fraction of area of a convex and closed plane area lying outside a circle with which it shares a diameter, a problem stemming from the theory of isoperimetric inequalities. In this paper such a bound is constructed and shown to be attained for a particular area. It is also shown that convexity is a necessary condition in order to avoid the whole area lying outside the circle.
The B{sup ?3/2} diffusion in magnetized plasma
Hsu, Jang-Yu; Wu, KaiBang [Department of Physics, National Cheng Kung University, Tainan, Taiwan (China)] [Department of Physics, National Cheng Kung University, Tainan, Taiwan (China); Kumar Agarwal, Sujeet [Ansal Institute of Technology and Management, Lucknow (India)] [Ansal Institute of Technology and Management, Lucknow (India); Ryu, Chang-Mo [Department of Physics, Pohang University of Science and Technology, Pohang, Kyungbuk 790-784 (Korea, Republic of)] [Department of Physics, Pohang University of Science and Technology, Pohang, Kyungbuk 790-784 (Korea, Republic of)
2013-06-15T23:59:59.000Z
Fluid equations with transport effects have been derived from summing up discrete particle effects in the configuration space. The diffusion coefficient takes a form different from, but equivalent to, the Kubo formula. By taking into account the decoherence along the field lines, the diffusive damping in the perpendicular direction, and the finite Larmor radius effect in the cyclotron resonance, it is shown that the diffusion of magnetized 3d plasma has a regime of B{sup ?3/2} scaling which lies between the Bohm diffusion of B{sup ?1} and the classical diffusion of B{sup ?2}.
Barclay, J.A.; Steyert, W.A.
1981-01-27T23:59:59.000Z
An apparatus and method for refrigeration are disclosed which provides efficient refrigeration over temperature ranges in excess of 20/sup 0/C and which requires no maintenance and is, therefore, usable on an unmanned satellite. The apparatus comprises a superconducting magnet which may be solenoidal. A piston comprising a substance such as a rare earth substance which is maintained near its Curie temperature reciprocates through the bore of the solenoidal magnet. A magnetic drive rod is connected to the piston and appropriate heat sinks are connected thereto. The piston is driven by a suitable mechanical drive such as an electric motor and cam. In practicing the invention, the body of the piston is magnetized and demagnetized as it moves through the magnetic field of the solenoid to approximate any of the following cycles or a condition thereof as well as, potentially, other cycles: Brayton, Carnot, Ericsson, and Stirling. Advantages of the present invention include: that refrigeration can be accomplished over at least a 20/sup 0/C scale at superconducting temperatures as well as at more conventional temperatures; very high efficiency, high reliability, and small size. (LCL)
The Poincare'-Lyapounov-Nekhoroshev theorem for involutory systems of vector fields
G. Gaeta
2006-03-05T23:59:59.000Z
We extend the Poincare'-Lyapounov-Nekhoroshev theorem from torus actions and invariant tori to general (non-abelian) involutory systems of vector fields and general invariant manifolds.
The $N-?$ Weak Axial-Vector Amplitude $C_{5}^a(0)$
Milton Dean Slaughter
1999-03-01T23:59:59.000Z
The weak $N-\\Delta$ axial-vector transition amplitude $$ - important in $N^{*}$ production processes in general and in isobar models describing $\
Geddes, Cameron Guy Robinson
Platforms Michael Welcome, Charles Rendleman, Leonid Oliker Computational Research Division Lawrence. It is therefore imperative to understand the tradeoffs between conventional scalar and parallel-vector platforms
The Poincare-Lyapounov-Nekhoroshev theorem for involutory systems of vector fields
Gaeta, Giuseppe [Dipartimento di Matematica, Universita di Milano, via Saldini 50, I-20133 Milan (Italy)]. E-mail: gaeta@mat.unimi.it
2006-06-15T23:59:59.000Z
We extend the Poincare-Lyapounov-Nekhoroshev theorem from torus actions and invariant tori to general (non-abelian) involutory systems of vector fields and general invariant manifolds.
Telloni, D. [National Institute for Astrophysics, Astrophysical Observatory of Torino, Via Osservatorio 20, I-10025 Pino Torinese (Italy); Perri, S.; Carbone, V. [Department of Physics, University of Calabria, Ponte P. Bucci Cubo 31C, I-87036 Rende (Italy); Bruno, R.; D Amicis, R. [National Institute for Astrophysics, Institute for Space Astrophysics and Planetology, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy)
2013-10-10T23:59:59.000Z
A statistical analysis of magnetic flux ropes, identified by large-amplitude, smooth rotations of the magnetic field vector and a low level of both proton density and temperature, has been performed by computing the invariants of the ideal magnetohydrodynamic (MHD) equations, namely the magnetic helicity, the cross-helicity, and the total energy, via magnetic field and plasma fluctuations in the interplanetary medium. A technique based on the wavelet spectrograms of the MHD invariants allows the localization and characterization of those structures in both scales and time: it has been observed that flux ropes show, as expected, high magnetic helicity states (|?{sub m}| in [0.6: 1]), but extremely variable cross-helicity states (|?{sub c}| in [0: 0.8]), which, however, are not independent of the magnetic helicity content of the flux rope itself. The two normalized MHD invariants observed within the flux ropes tend indeed to distribute, neither trivially nor automatically, along the ?(?{sub m}{sup 2}+?{sub c}{sup 2})=1 curve, thus suggesting that some constraint should exist between the magnetic and cross-helicity content of the structures. The analysis carried out has further showed that the flux rope properties are totally independent of their time duration and that they are detected either as a sort of interface between different portions of solar wind or as isolated structures embedded in the same stream.
Frustrated Magnetism in Low-Dimensional Lattices
Tovar, Mayra
2011-01-01T23:59:59.000Z
and C. Baines. Quantum magnetism in the paratacamite family:14] Stephen Blundell. Magnetism in Condensed Matter. OxfordElectrons and Quantum Magnetism. Graduate Texts in Con-
Magnetic spectroscopy and microscopy of functional materials
Jenkins, C.A.
2012-01-01T23:59:59.000Z
transitions for magnetic refrigeration. Appl Phys Lett, 97(these e?ects in magnetic refrigeration and actuation makesheat ?ow with the goal of magnetic refrigeration (adiabatic
Superconducting Magnet Technology for Future Hadron Colliders
Scanlan, R.M.
2011-01-01T23:59:59.000Z
I. Superconducting Magnet Technology for Future Hadl"On1994. M.N. Wilson, Superconducting Magnets (Clarendon Press,The application of superconducting magnets to large-scale
Aized, D.; Schwall, R.E.
1999-06-22T23:59:59.000Z
A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil. 15 figs.
Aized, Dawood (Marlboro, MA); Schwall, Robert E. (Northborough, MA)
1999-06-22T23:59:59.000Z
A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil.
Magnetic fluid flow phenomena in DC and rotating magnetic fields
Rhodes, Scott E. (Scott Edward), 1981-
2004-01-01T23:59:59.000Z
An investigation of magnetic fluid experiments and analysis is presented in three parts: a study of magnetic field induced torques in magnetorheological fluids, a characterization and quantitative measurement of properties ...
Magnetic catalysis and inverse magnetic catalysis in QCD
Niklas Mueller; Jan M. Pawlowski
2015-02-27T23:59:59.000Z
We investigate the effects of strong magnetic fields on the QCD phase structure at vanishing density by solving the gluon and quark gap equations, and by studying the dynamics of the quark scattering with the four-fermi coupling. The chiral crossover temperature as well as the chiral condensate are computed. For asymptotically large magnetic fields we find magnetic catalysis, while we find inverse magnetic catalysis for intermediate magnetic fields. Moreover, for large magnetic fields the chiral phase transition for massless quarks turns into a crossover. The underlying mechanisms are then investigated analytically within a few simplifications of the full numerical analysis. We find that a combination of gluon screening effects and the weakening of the strong coupling is responsible for the phenomenon of inverse catalysis. In turn, the magnetic catalysis at large magnetic field is already indicated by simple arguments based on dimensionality.
Magnetic nanowire based high resolution magnetic force microscope probes
Qin, Lu-Chang
-resolution magnetic force microscope probes using preformed magnetic nanowires. Nickel and cobalt nanowires produced by electrodeposition were directly assembled onto the tip of a commercial atomic force microscope cantilever
Translating Answer-Set Programs into Bit-Vector Logic
Nguyen, Mai; Niemelä, Ilkka
2011-01-01T23:59:59.000Z
Answer set programming (ASP) is a paradigm for declarative problem solving where problems are first formalized as rule sets, i.e., answer-set programs, in a uniform way and then solved by computing answer sets for programs. The satisfiability modulo theories (SMT) framework follows a similar modelling philosophy but the syntax is based on extensions of propositional logic rather than rules. Quite recently, a translation from answer-set programs into difference logic was provided---enabling the use of particular SMT solvers for the computation of answer sets. In this paper, the translation is revised for another SMT fragment, namely that based on fixed-width bit-vector theories. Thus, even further SMT solvers can be harnessed for the task of computing answer sets. The results of a preliminary experimental comparison are also reported. They suggest a level of performance which is similar to that achieved via difference logic.
Exploring Vector Fields with Distribution-based Streamline Analysis
Lu, Kewei; Chaudhuri, Abon; Lee, Teng-Yok; Shen, Han-Wei; Wong, Pak C.
2013-02-26T23:59:59.000Z
Streamline-based techniques are designed based on the idea that properties of streamlines are indicative of features in the underlying field. In this paper, we show that statistical distributions of measurements along the trajectory of a streamline can be used as a robust and effective descriptor to measure the similarity between streamlines. With the distribution-based approach, we present a framework for interactive exploration of 3D vector fields with streamline query and clustering. Streamline queries allow us to rapidly identify streamlines that share similar geometric features to the target streamline. Streamline clustering allows us to group together streamlines of similar shapes. Based on users selection, different clusters with different features at different levels of detail can be visualized to highlight features in 3D flow fields. We demonstrate the utility of our framework with simulation data sets of varying nature and size.
Vector norms, convex bodies and subordinate matrix norms
Dean, Joe Harvey
1971-01-01T23:59:59.000Z
y + . . . + x y n n' Efe have [6] (2. 4) o & I Ix~oyl I, = &x+a?x+?) = ( -) + &x y' + ' 2 = I I I I', + o(x?) + (x, y) + ' " I lyl 12 Echen (x, y) = 0, the Cauchy-ScEurartz inequality is obviously true. Ec'hen (x, y) $ 0, let u = ? I I xl I (x... sum, ;-ill be used in proving an eouality . ;Ixich will be used in the proof of Theorea 4. 1. DEFTNITTON 4. L. The Ninkowski sum [4] of ts;o; ts. G and 8 n in E is given by G 6 Ii = {g -I- h ~ g G, h s ii). Normal vector n addition in E is used...
Limited Holism and Real-Vector-Space Quantum Theory
Lucien Hardy; William K. Wootters
2010-05-26T23:59:59.000Z
Quantum theory has the property of "local tomography": the state of any composite system can be reconstructed from the statistics of measurements on the individual components. In this respect the holism of quantum theory is limited. We consider in this paper a class of theories more holistic than quantum theory in that they are constrained only by "bilocal tomography": the state of any composite system is determined by the statistics of measurements on pairs of components. Under a few auxiliary assumptions, we derive certain general features of such theories. In particular, we show how the number of state parameters can depend on the number of perfectly distinguishable states. We also show that real-vector-space quantum theory, while not locally tomographic, is bilocally tomographic.
Magnetic Field Measurement System
Kulesza, Joe; Johnson, Eric; Lyndaker, Aaron; Deyhim, Alex; Waterman, Dave; Blomqvist, K. Ingvar [Advanced Design Consulting USA, 126 Ridge Road, P.O. Box 187, Lansing, NY 14882 (United States); Dunn, Jonathan Hunter [MAX-lab, SE-221 00 Lund (Sweden)
2007-01-19T23:59:59.000Z
A magnetic field measurement system was designed, built and installed at MAX Lab, Sweden for the purpose of characterizing the magnetic field produced by Insertion Devices (see Figure 1). The measurement system consists of a large granite beam roughly 2 feet square and 14 feet long that has been polished beyond laboratory grade for flatness and straightness. The granite precision coupled with the design of the carriage yielded minimum position deviations as measured at the probe tip. The Hall probe data collection and compensation technique allows exceptional resolution and range while taking data on the fly to programmable sample spacing. Additional flip coil provides field integral data.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power Administration would likeConstitution AndControllingCool Magnetic Molecules Cool Magnetic
Vector spectropolarimetry of dark-cored penumbral filaments with Hinode
L. R. Bellot Rubio; S. Tsuneta; K. Ichimoto; Y. Katsukawa; B. W. Lites; S. Nagata; T. Shimizu; R. A. Shine; Y. Suematsu; T. D. Tarbell; A. M. Title; J. C. del Toro Iniesta
2007-08-21T23:59:59.000Z
We present spectropolarimetric measurements of dark-cored penumbral filaments taken with Hinode at a resolution of 0.3". Our observations demonstrate that dark-cored filaments are more prominent in polarized light than in continuum intensity. Far from disk center, the Stokes profiles emerging from these structures are very asymmetric and show evidence for magnetic fields of different inclinations along the line of sight, together with strong Evershed flows of at least 6-7 km/s. In sunspots closer to disk center, dark-cored penumbral filaments exhibit regular Stokes profiles with little asymmetries due to the vanishing line-of-sight component of the horizontal Evershed flow. An inversion of the observed spectra indicates that the magnetic field is weaker and more inclined in the dark cores as compared with the surrounding bright structures. This is compatible with the idea that dark-cored filaments are the manifestation of flux tubes carrying hot Evershed flows.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
and users are interested in understanding all of these large processes and more, by examining them at the size that matters most: the pore scale. Through creation of...
Seward, Trenee
2010-07-14T23:59:59.000Z
. Be fore I could properly adjust things, Daddy nudged me in my ribs with the television remo te and motioned for me to move out of his way. I playfully punched his arm and turned to see what had him adjusting his eyeglasses. For several minutes we... instructed her not to add any ice to his sweet tea, like she didn?t know his preferences by now. ? Jeopardy time, huh boy?? Daddy peered over the top of his eyeglasses and stared over at me. Daddy?s hair had been fu lly grey and his eyes bad since the day...
Magnetic nanoworms Systematic Surface Engineering of Magnetic Nanoworms
Bhatia, Sangeeta
Magnetic nanoworms Systematic Surface Engineering of Magnetic Nanoworms for in vivo Tumor Targeting and Engineering Program Department of Chemistry and Biochemistry University of California, San Diego 9500 Gilman magnetic materials nanoworms peptides tumor targeting 694 ß 2009 Wiley-VCH Verlag GmbH & Co. KGa
Magnetic Coordinates for Systems with Imperfect Magnetic Surfaces
Dewar, Robert L.
Magnetic Coordinates for Systems with Imperfect Magnetic Surfaces R. L. Dewar and S. R. Hudson & Engineering, The Australian National University, Canberra, A.C.T. 0200, Australia e-mail: robert-orbits, and the surfaces are formed from a continuous one-parameter family of such orbits. Magnetic field-line flow
Ole L. Trinhammer
2012-06-25T23:59:59.000Z
We present a hamiltonian structure on the Lie group u(3) to describe the baryon spectrum. The ground state is identified with the proton. From this single fit we calculate approximately the relative neutron to proton mass shift to within half a percentage of the experimental value. From the same fit we calculate the nucleon and delta resonance spectrum with correct grouping and no missing resonances. For specific spin eigenfunctions we calculate the delta to nucleon mass ratio to within one percent. Finally we derive parton distribution functions that compare well with those for the proton valence quarks. The distributions are generated by projecting the proton state to space via the exterior derivative on u(3). We predict scarce neutral flavour singlets which should be visible in neutron diffraction dissociation experiments or in invariant mass spectra of protons and negative pions in B-decays and in photoproduction on neutrons. The presence of such singlet states distinguishes experimentally the present model from the standard model as does the prediction of the neutron to proton mass splitting. Conceptually the Hamiltonian may describe an effective phenomenology or more radically describe interior dynamics implying quarks and gluons as projections from u(3) which we then call allospace.
Lee, Jae-Kwang; Fujiwara, Takashige; Kofron, William G. [Department of Chemistry and Center for Laser and Optical Spectroscopy, University of Akron, Akron, Ohio 44325-3601 (United States); Zgierski, Marek Z.; Lim, Edward C. [Steacie Institute for Molecular Sciences, National Research Council of Canada, Ottawa K1A 0R6 (Canada)
2008-04-28T23:59:59.000Z
Electronic absorption spectra of the low-lying {pi}{pi}* and {pi}{sigma}* states of several aminobenzonitriles and 4-dimethylaminobenzethyne have been studied by time-resolved transient absorption and time-dependent density functional theory calculation. In acetonitrile, the lifetime of the {pi}{sigma}*-state absorption is very short (picoseconds or subpicosecond) for molecules that exhibit intramolecular charge transfer (ICT), and very long (nanoseconds) for those that do not. Where direct comparison of the temporal characteristics of the {pi}{sigma}*-state and the ICT-state transients could be made, the formation rate of the ICT state is identical to the decay rate of the {pi}{sigma}* state within the experimental uncertainty. These results are consistent with the {pi}{sigma}*-mediated ICT mechanism, L{sub a} ({pi}{pi}*){yields}{pi}{sigma}*{yields}ICT, in which the decay rate of the {pi}{sigma}* state is determined by the rate of the solvent-controlled {pi}{sigma}*{yields}ICT charge-shift reaction. The {pi}{pi}*{yields}{pi}{sigma}* state crossing does not occur in 3-dimethylaminobenzonitrile or 2-dimethylaminobenzonitrile, as predicted by the calculation, and 4-aminobenzonitrile and 4-dimethylaminobenzethyne does not exhibit the ICT reaction, consistent with the higher energy of the ICT state relative to the {pi}{sigma}* state.
Chapman, Robin
's eight term exact sequence in integral group homology [BrLo] to an eight term exact sequence in group of nonabelian derived functors, an eight term exact sequence of Lie algebra homology with #/q# coe homology with Z q = Z/qZ coe#cients, where q is a nonnegative integer. For any group G and its normal
Mei, H; Yao, J M; Motoba, T
2015-01-01T23:59:59.000Z
We present a detailed formalism of the microscopic particle-rotor model for hypernuclear low-lying states based on a covariant density functional theory. In this method, the hypernuclear states are constructed by coupling a hyperon to low-lying states of the core nucleus, which are described by the generator coordinate method (GCM) with the particle number and angular momentum projections. We apply this method to study in detail the low-lying spectrum of $^{13}_{~\\Lambda}$C and $^{21}_{~\\Lambda}$Ne hypernuclei. We also briefly discuss the structure of $^{155}_{~~\\Lambda}$Sm as an example of heavy deformed hypernuclei. It is shown that the low-lying excitation spectrum with positive parity states of the hypernuclei, which are dominated by $\\Lambda$ hyperon in $s$-orbital coupled to the core states, are similar to that for the corresponding core states, while the electric quadrupole transition strength, $B(E2)$, from the 2$^+_1$ state to the ground state is reduced according to the mass number of the hypernucle...
Multireference Ab Initio Study of the Ground and Low-Lying Excited States of Cr(CO)2 and Cr(CO)3
Ihee, Hyotcherl
Multireference Ab Initio Study of the Ground and Low-Lying Excited States of Cr(CO)2 and Cr(CO)3 chromium carbonyls, Cr(CO)2 and Cr(CO)3, using multiconfigurational ab initio perturbation theory. Unlike of the ground states of Cr(CO)2 and Cr(CO)3. From multireference ab initio calculations considering the full
Magnetic refrigeration apparatus and method
Barclay, John A. (Los Alamos, NM); Overton, Jr., William C. (Los Alamos, NM); Stewart, Walter F. (Los Alamos, NM)
1984-01-01T23:59:59.000Z
The disclosure relates to refrigeration through magnetizing and demagnitizing a body by rotating it within a magnetic field. Internal and external heat exchange fluids and in one embodiment, a regenerator, are used.
Large Magnetization at Carbon Surfaces
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure...
Optically Enhanced Magnetic Resonance
Suter, Dieter
, like spatial structures or molecular dynamics. While the direct excitation of nuclear spin transitions.1 Motivation The physical mechanism of nuclear magnetic resonance spectroscopy, the excitation of transitions light for polarizing the spin system or for observing its dynamics. This possibility arises from
Kirol, Lance D. (Shelly, ID)
1988-01-01T23:59:59.000Z
A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.
Kirol, L.D.
1987-02-11T23:59:59.000Z
A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.
Jackson, Jasper A. (Los Alamos, NM); Cooper, Richard K. (Los Alamos, NM)
1982-01-01T23:59:59.000Z
Means for producing a region of homogeneous magnetic field remote from the source of the field, wherein two equal field sources are arranged axially so their fields oppose, producing a region near the plane perpendicular to the axis midway between the sources where the radial component of the field goes through a maximum. Near the maximum, the field is homogeneous over prescribed regions.
G. Giacomelli; L. Patrizii
2005-06-07T23:59:59.000Z
In these lecture notes we discuss the status of the searches for classical Dirac Magnetic Monopoles (MMs) at accelerators, for GUT superheavy MMs in the penetrating cosmic radiation and for Intermediate Mass MMs. Also the searches for nuclearites and Q-balls are considered.
Magnetic refrigeration for spacecraft systems
Barclay, J.A.
1981-01-01T23:59:59.000Z
Magnetic refrigerators, i.e., those that use the magnetocaloric effect of a magnetic working material in a thermodynamic cycle, offer potentially reliable, and efficient refrigeration over a variety of temperature ranges and cooling powers. A descriptive analysis of magnetic refrigeration systems is performed with particular emphasis on more efficient infrared detector cooling. Three types of magnetic refrigerator designs are introduced to illustrate some of the possibilities.
Ames Lab 101: Magnetic Refrigeration
Pecharsky, Vitalij
2013-03-01T23:59:59.000Z
Vitalij Pecharsky, distinguished professor of materials science and engineering, discusses his research in magnetic refrigeration at Ames Lab.
Ames Lab 101: Magnetic Refrigeration
Pecharsky, Vitalij
2011-01-01T23:59:59.000Z
Vitalij Pecharsky, distinguished professor of materials science and engineering, discusses his research in magnetic refrigeration at Ames Lab.
Magnetic reconnection in nontoroidal plasmas
Boozer, Allen H. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)
2005-07-15T23:59:59.000Z
Magnetic reconnection is a major issue in solar and astrophysical plasmas. The mathematical result that the evolution of a magnetic field with only point nulls is always locally ideal limits the nature of reconnection in nontoroidal plasmas. Here it is shown that the exponentially increasing separation of neighboring magnetic field lines, which is generic, tends to produce rapid magnetic reconnection if the length of the field lines is greater than about 20 times the exponentiation, or Lyapunov, length.
Mao, S. A. [National Radio Astronomy Observatory, P.O. Box O, Socorro, NM 87801 (United States); McClure-Griffiths, N. M.; McConnell, D. [Australia Telescope National Facility, CSIRO Astronomy and Space Science, Epping, NSW 1710 (Australia); Gaensler, B. M. [Sydney Institute for Astronomy, School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Haverkorn, M. [Department of Astrophysics, Radboud University, P.O. Box 9010, 6500-GL Nijmegen (Netherlands); Beck, R. [Max-Planck-Institut fuer Radioastronomie, D-53121 Bonn (Germany); Wolleben, M. [Square Kilometre Array South Africa, The Park, Pinelands 7405 (South Africa); Stanimirovic, S. [Department of Astronomy, University of Wisconsin, Madison, WI 53706 (United States); Dickey, J. M. [Physics Department, University of Tasmania, Hobart, TAS 7001 (Australia); Staveley-Smith, L., E-mail: mao@astro.wisc.edu [International Centre for Radio Astronomy Research (ICRAR), The University of Western Australia, Crawley, WA 6009 (Australia)
2012-11-01T23:59:59.000Z
We present a study of the magnetic field of the Large Magellanic Cloud (LMC), carried out using diffuse polarized synchrotron emission data at 1.4 GHz acquired at the Parkes Radio Telescope and the Australia Telescope Compact Array. The observed diffuse polarized emission is likely to originate above the LMC disk on the near side of the galaxy. Consistent negative rotation measures (RMs) derived from the diffuse emission indicate that the line-of-sight magnetic field in the LMC's near-side halo is directed coherently away from us. In combination with RMs of extragalactic sources that lie behind the galaxy, we show that the LMC's large-scale magnetic field is likely to be of quadrupolar geometry, consistent with the prediction of dynamo theory. On smaller scales, we identify two brightly polarized filaments southeast of the LMC, associated with neutral hydrogen arms. The filaments' magnetic field potentially aligns with the direction toward the Small Magellanic Cloud (SMC). We suggest that tidal interactions between the SMC and the LMC in the past 10{sup 9} years are likely to have shaped the magnetic field in these filaments.
Rajpoot, Nasir
Wavelets and Support Vector Machines for Texture Classification Kashif Mahmood Rajpoot Nasir@dcs.warwick.ac.uk Abstract We present a novel texture classification algorithm using 2-D discrete wavelet transform (DWT, and a local energy function is computed corresponding to each pixel of the feature images. This feature vector
Numerical methods for vector Stefan models of solid-state alloys
Vuik, Kees
-called aluminium-based alloys. Subsequently, the obtained alloy is cast into a mould where it solidifies. DuringNumerical methods for vector Stefan models of solid-state alloys PROEFSCHRIFT ter verkrijging van for vector Stefan models of solid-state alloys. Dissertation at Delft University of Technology. Copyright c
Johnson, Brody Dylan
ORTHOGONAL WAVELET FRAMES AND VECTOR-VALUED WAVELET TRANSFORMS GHANSHYAM BHATT, BRODY DYLAN JOHNSON for the construction of orthogonal MRA wavelet frames in L2 (R) from a suitable scaling function. These constructions banks, the orthogonal wavelet frames give rise to a vector-valued discrete wavelet transform (VDWT
Accelerating SSL using the Vector processors in IBM's Cell Broadband Engine
Accelerating SSL using the Vector processors in IBM's Cell Broadband Engine for Sony's Playstation and performance gains when using the vector processing capabilities for SSL and shows that big improve- ments are still possible with the hardware designed primarily for other purposes. 1 Why SSL? Despite huge gains
Artistic Resizing: A Technique for Rich Scale-Sensitive Vector Graphics Pierre Dragicevic
Artistic Resizing: A Technique for Rich Scale-Sensitive Vector Graphics Pierre Dragicevic, vector graphics with non-uniform resizing: the 2nd and 4th variants have been drawn in Illustrator is given more and more importance in graphical user interfaces. This points out the need for new methods
Majumdar, Sharan
of winds of hurricane force (32.9 m sÀ1 ) in extratropical cyclones and marine weather over the open oceanValidation of QuikSCAT wind vectors by dropwindsonde data from Dropwindsonde Observations January 2010. [1] The accuracy of 10 m wind vectors derived from the QuikSCAT satellite near tropical
Identifying damage locations under ambient vibrations utilizing vector autoregressive models Keywords: Damage location Ambient vibration Vector Autoregressive model Statistical pattern recognition Bridges Structural health monitoring a b s t r a c t This paper presents a study for identifying damage
Exclusive search for Higgs boson to gamma-gamma decay via vector boson fusion production mechanism
Rankin, Dylan Sheldon
2012-01-01T23:59:59.000Z
We perform an exclusive search for the Higgs boson to gamma-gamma decay via vector boson fusion. We utilize the characteristic features of vector boson fusion, such as the di-jet [Delta][eta] and mass, as well as the ...
Using Bit-Vector Decision Procedures for Analysis of Protein Folding Pathways
Langmead, Christopher James
Using Bit-Vector Decision Procedures for Analysis of Protein Folding Pathways Christopher James-vector decision procedures for the analysis of protein folding pathways. We argue that the protein fold- ing by the different nature of the protein folding problem, we present a translation of the protein folding pathways
Beaver: Engineering an Efficient SMT Solver for Bit-Vector Arithmetic
Seshia, Sanjit A.
Beaver: Engineering an Efficient SMT Solver for Bit-Vector Arithmetic Susmit Jha, Rhishikesh Limaye the key ideas in the design and implementation of Beaver, an SMT solver for quantifier-free finite-precision bit-vector logic (QF BV). Beaver uses an eager approach, encoding the original SMT problem
Comets: A Fast, Intuitive, 3D Vector Glyph Alejandro Aceves-Gaona and Robert R. Lewis
Lewis, Robert R.
State University School of Electrical Engineering and Computer Science e-mail: {aaceves, bobl}@tricity.wsu.edu Abstract We present a new glyph called a "comet" to represent vectors. Comets improve the accuracy an ambiguity possible with conventional vector glyphs. By using a hue-lightness-saturation (HLS) color space
Detecting Selective Forwarding Attacks in Wireless Sensor Networks using Support Vector Machines
Shilton, Alistair
concerning energy . In this article, we propose a centralized intrusion detection scheme based on SupportDetecting Selective Forwarding Attacks in Wireless Sensor Networks using Support Vector Machines Vector Machines (SVMs) and sliding windows. We find that our system can detect black hole attacks
Zero-knowledge Test of Vector Equivalence and Granulation of User Data with Privacy
Canny, John
Zero-knowledge Test of Vector Equivalence and Granulation of User Data with Privacy Yitao Duan architecture and practical protocols for user data validation and vector addition based computation. It turned, in a privacy-preserving manner. They can also be of independent interest for other fields such as data mining
Effects of (N)over-Barn Polarization on Vector-Meson Masses at Finite-Temperature
Song, C. S.; Xia, P. W.; Ko, Che Ming.
1995-01-01T23:59:59.000Z
Effects of (N) over bar N polarization on vector meson (rho and omega) masses at finite temperature are studied. Including a reduced nucleon mass in a hot matter, we find that the reduction of vector meson masses due to the vacuum effect is larger...
Covariant Lyapunov vectors for rigid disk systems Hadrien Bosetti, Harald A. Posch *
Dellago, Christoph
Covariant Lyapunov vectors for rigid disk systems Hadrien Bosetti, Harald A. Posch * Computational l e i n f o Article history: Available online 10 June 2010 Keywords: Lyapunov instability Hard disks Covariant vectors Statistical mechanics Computer simulation Fluids Lyapunov modes a b s t r a c t We carry
Covariant Lyapunov vectors and local exponents Harald A. Posch and Hadrien Bosetti
Posch, Harald A.
Covariant Lyapunov vectors and local exponents Harald A. Posch and Hadrien Bosetti Faculty the perturbation vectors in tangent space and the associated local Lyapunov exponents. We also find that the local covariant exponents vary discontinuously along directions transverse to the phase flow. Keywords: Lyapunov
An Electron Fixed Target Experiment to Search for a New Vector Boson A' Decaying to e+e-
Essig, Rouven; Schuster, Philip; /SLAC; Toro, Natalia; /Stanford U., Phys. Dept.; Wojtsekhowski, Bogdan; /Jefferson Lab; ,
2010-06-11T23:59:59.000Z
We describe an experiment to search for a new vector boson A' with weak coupling {alpha}' {approx}> 6 x 10{sup -8} {alpha} to electrons ({alpha} = e{sup 2}/4{pi}) in the mass range 65 MeV < m{sub A'} < 550 MeV. New vector bosons with such small couplings arise naturally from a small kinetic mixing of the 'dark photon' A' with the photon - one of the very few ways in which new forces can couple to the Standard Model - and have received considerable attention as an explanation of various dark matter related anomalies. A' bosons are produced by radiation off an electron beam, and could appear as narrow resonances with small production cross-section in the trident e{sup +}e{sup -} spectrum. We summarize the experimental approach described in a proposal submitted to Jefferson Laboratory's PAC35, PR-10-009. This experiment, the A' Experiment (APEX), uses the electron beam of the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory (CEBAF) at energies of {approx} 1-4 GeV incident on 0.5-10% radiation length Tungsten wire mesh targets, and measures the resulting e{sup +}e{sup -} pairs to search for the A' using the High Resolution Spectrometer and the septum magnet in Hall A. With a {approx} 1 month run, APEX will achieve very good sensitivity because the statistics of e{sup +}e{sup -} pairs will be {approx} 10,000 times larger in the explored mass range than any previous search for the A' boson. These statistics and the excellent mass resolution of the spectrometers allow sensitivity to {alpha}'/{alpha} one to three orders of magnitude below current limits, in a region of parameter space of great theoretical and phenomenological interest. Similar experiments could also be performed at other facilities, such as the Mainz Microtron.
Andrew Chubykalo; Augusto Espinoza; Rumen Tzonchev
2005-03-24T23:59:59.000Z
It is shown that the generally accepted definition of the Poynting vector and the energy flux vector defined by means of the energy density of the electromagnetic field (Umov vector) lead to the prediction of the different results touching electromagnetic energy flux. The experiment shows that within the framework of the mentioned generally accepted definitions the Poynting vector adequately describes the electromagnetic energy flux unlike the Umov vector. Therefore one can conclude that a generally accepted definitions of the electromagnetic energy density and the Poynting vector, in general, are not always compatible.
Obliquely propagating waves in the magnetized strongly coupled one-component plasma
Kählert, Hanno; Kalman, Gabor J. [Department of Physics, Boston College, 140 Commonwealth Ave, Chestnut Hill, Massachusetts 02467 (United States)] [Department of Physics, Boston College, 140 Commonwealth Ave, Chestnut Hill, Massachusetts 02467 (United States); Ott, Torben; Bonitz, Michael [Institut für Theoretische Physik und Astrophysik, Christian-Albrechts Universität zu Kiel, Leibnizstr. 15, 24098 Kiel (Germany)] [Institut für Theoretische Physik und Astrophysik, Christian-Albrechts Universität zu Kiel, Leibnizstr. 15, 24098 Kiel (Germany); Reynolds, Alexi [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)] [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)
2013-05-15T23:59:59.000Z
The quasi-localized charge approximation is used to calculate the wave spectrum of the magnetized three-dimensional strongly coupled one-component plasma at arbitrary angles ? between the wave vector and the magnetic field axis. Three frequency branches are identified whose interplay is strongly determined by ?=?{sub c}/?{sub p}, the ratio of the cyclotron frequency ?{sub c}, and the plasma frequency ?{sub p}. The frequency dispersion relations for the three principal modes along the magnetic field cross in the case ?<1, which strongly affects the transition from parallel to perpendicular wave propagation. For ?>1, the frequencies of the different branches are well separated, and the long-wavelength dispersion in the intermediate and upper branch changes sign as ? is varied from 0 to ?/2. In addition to the frequencies, we also investigate the waves' polarization properties.
A simple method for characterization of the magnetic field in an ion trap using Be+ ions
Jianwei Shen; Andrii Borodin; Stephan Schiller
2014-10-06T23:59:59.000Z
We demonstrate a simple method for the determination of the magnetic field in an ion trap using laser-cooled Be+ ions. The method is not based on magnetic resonance and thus does not require delivering radiofrequency (RF) radiation to the trap. Instead, stimulated Raman spectroscopy is used, and only an easily generated optical sideband of the laser cooling wave is required. The d.c. magnetic vector, averaged over the Be+ ion ensemble, is determined. Furthermore, the field strength can be minimized and an upper limit for the field gradient can be determined. The resolution of the method is 0.04 G at present. The relevance for precision rovibrational spectroscopy of molecular hydrogen ions is briefly discussed.
Jeremy S. Heyl; Don Lloyd; Nir J. Shaviv
2005-02-17T23:59:59.000Z
In the presence of strong magnetic fields, the vacuum becomes a birefringent medium. We show that this QED effect couples the direction of the polarization of photons leaving the NS surface, to the direction of the magnetic field along the ray's path. We analyze the consequences that this effect has on aligning the polarization vectors to generate large net polarizations, while considering thermal radiation originating from a thermal hydrogen atmosphere. Counter to previous predictions, we show that the thermal radiation should be highly polarized even in the optical. When detected, this polarization will be the first demonstration of vacuum birefringence. It could be used as a tool to prove the high magnetic field nature of AXPs and it could also be used to constrain physical NS parameters, such as $R/M$, to which the net polarization is sensitive.
Compositional dependence of the magnetic properties of epitaxial FeV/MgO thin films
Devolder, T., E-mail: thibaut.devolder@u-psud.fr; Eimer, S. [Institut d'Electronique Fondamentale, CNRS, UMR 8622, Orsay (France) [Institut d'Electronique Fondamentale, CNRS, UMR 8622, Orsay (France); Univ. Paris-Sud, 91405 Orsay (France); Tahmasebi, T. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium)] [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Hauet, T.; Andrieu, S. [Institut Jean Lamour, CNRS - Universite de Lorraine, Boulevard des aiguillettes BP 70239, F-54506 Vandoeuvre le‘s Nancy (France)] [Institut Jean Lamour, CNRS - Universite de Lorraine, Boulevard des aiguillettes BP 70239, F-54506 Vandoeuvre le‘s Nancy (France)
2013-12-09T23:59:59.000Z
Owing to their bcc structures and the low lattice misfit with MgO, FeV alloys are interesting for MgO-based magnetic tunnel junctions. We use vector network analyzer ferromagnetic resonance to measure the magnetization, anisotropy, exchange stiffness, and damping of epitaxial FeV/MgO thin alloys of various V contents. The low magnetization, very high exchange stiffness (23 pJ/m) and very low effective damping (<0.0026) of the alloy with 20% V content makes it an interesting candidate for spin torque applications. The ultralow damping is consistent with a spin-orbit origin, which sheds light on the possible strategies to reduce the damping in alloys.
Future Directions for Magnetic Sensors
and Engineering Laboratory Magnetic tunnel junction (MTJ) sensors are rapidly becoming the technology of choiceFuture Directions for Magnetic Sensors: HYBRIDMATERIALS Our goal is to develop the scientific expertise needed to allow modeling and simulation to become the driving force in improving magnetic sensors
Weston, Ken
at the Magnet Lab like? Often, it's about solving problems. That's what engineers Scott Bole and Lee Marks didRobotics Club! page 16 Using magnets to analyze oil page 28 #12;editor's note What's a typical day recently. Their story began when Lee noticed something odd going on during a magnet-building project: When
LABORATORY VI ELECTRICITY FROM MAGNETISM
Minnesota, University of
LABORATORY VI ELECTRICITY FROM MAGNETISM Lab VI - 1 In the previous problems you explored the magnetic field and its effect on moving charges. You also saw how electric currents could create magnetic can give rise to electric currents. This is the effect that allows the generation of electricity
Enlarge Image Peer pressure. Magnetic
Thywissen, Joseph
to stick it to your refrigerator, but an ultra-cold gas magnetizes itself just as do metals such as ironEnlarge Image Peer pressure. Magnetic domains in steel (vertical bans) arise when neighboring electrons point their magnetic poles in the same direction. CREDIT: ZUREKS, CHRIS VARDON
Low-temperature magnetic refrigerator
Barclay, J.A.
1983-05-26T23:59:59.000Z
The invention relates to magnetic refrigeration and more particularly to low temperature refrigeration between about 4 and about 20 K, with an apparatus and method utilizing a belt of magnetic material passed in and out of a magnetic field with heat exchangers within and outside the field operably disposed to accomplish refrigeration.
Low-temperature magnetic refrigerator
Barclay, John A. (Los Alamos, NM)
1985-01-01T23:59:59.000Z
The disclosure is directed to a low temperature 4 to 20 K. refrigeration apparatus and method utilizing a ring of magnetic material moving through a magnetic field. Heat exchange is accomplished in and out of the magnetic field to appropriately utilize the device to execute Carnot and Stirling cycles.
Low field magnetic resonance imaging
Pines, Alexander (Berkeley, CA); Sakellariou, Dimitrios (Billancourt, FR); Meriles, Carlos A. (Fort Lee, NJ); Trabesinger, Andreas H. (London, GB)
2010-07-13T23:59:59.000Z
A method and system of magnetic resonance imaging does not need a large homogenous field to truncate a gradient field. Spatial information is encoded into the spin magnetization by allowing the magnetization to evolve in a non-truncated gradient field and inducing a set of 180 degree rotations prior to signal acquisition.
THE MAGNETIC FIELD IN TAURUS PROBED BY INFRARED POLARIZATION
Chapman, Nicholas L.; Goldsmith, Paul F.; Pineda, Jorge L.; Li Di [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, MS 301-429, Pasadena, CA 91109 (United States); Clemens, D. P. [Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Krco, Marko, E-mail: nchapman@u.northwestern.edu [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States)
2011-11-01T23:59:59.000Z
We present maps of the plane-of-sky magnetic field within two regions of the Taurus molecular cloud: one in the dense core L1495/B213 filament and the other in a diffuse region to the west. The field is measured from the polarization of background starlight seen through the cloud. In total, we measured 287 high-quality near-infrared polarization vectors in these regions. In L1495/B213, the percent polarization increases with column density up to A{sub V} {approx} 9 mag, the limits of our data. The radiative torques model for grain alignment can explain this behavior, but models that invoke turbulence are inconsistent with the data. We also combine our data with published optical and near-infrared polarization measurements in Taurus. Using this large sample, we estimate the strength of the plane-of-sky component of the magnetic field in nine subregions. This estimation is done with two different techniques that use the observed dispersion in polarization angles. Our values range from 5 to 82 {mu}G and tend to be higher in denser regions. In all subregions, the critical index of the mass-to-magnetic flux ratio is sub-unity, implying that Taurus is magnetically supported on large scales ({approx}2 pc). Within the region observed, the B213 filament takes a sharp turn to the north and the direction of the magnetic field also takes a sharp turn, switching from being perpendicular to the filament to becoming parallel. This behavior can be understood if we are observing the rim of a bubble. We argue that it has resulted from a supernova remnant associated with a recently discovered nearby gamma-ray pulsar.
Vector Calculus in Non-Integer Dimensional Space and its Applications to Fractal Media
Vasily E. Tarasov
2015-03-06T23:59:59.000Z
We suggest a generalization of vector calculus for the case of non-integer dimensional space. The first and second orders operations such as gradient, divergence, the scalar and vector Laplace operators for non-integer dimensional space are defined. For simplification we consider scalar and vector fields that are independent of angles. We formulate a generalization of vector calculus for rotationally covariant scalar and vector functions. This generalization allows us to describe fractal media and materials in the framework of continuum models with non-integer dimensional space. As examples of application of the suggested calculus, we consider elasticity of fractal materials (fractal hollow ball and fractal cylindrical pipe with pressure inside and outside), steady distribution of heat in fractal media, electric field of fractal charged cylinder. We solve the correspondent equations for non-integer dimensional space models.
A Study of Liquid Metal Film Flow, Under Fusion Relevant Magnetic Fields
Narula, M.; Ying, A.; Abdou, M.A. [UCLA (United States)
2005-04-15T23:59:59.000Z
The use of flowing liquid metal streams or 'liquid walls' as a plasma contact surface is a very attractive option and has received considerable attention over the past several years both in the plasma physics and fusion engineering programs. A key issue for the feasibility of flowing liquid metal plasma facing component (PFC) systems, lies in their magnetohydrodynamic (MHD) behavior. The spatially varying magnetic field environment, typical of a fusion device can lead to serious flow disrupting MHD forces that hinder the development of a smooth and controllable flow needed for PFC applications. The present study builds up on the ongoing research effort at UCLA, directed towards providing qualitative and quantitative data on liquid metal free surface flow behavior under fusion relevant magnetic fields, to aid in better understanding of flowing liquid metal PFC systems.
Large-scale weakly nonlinear perturbations of convective magnetic dynamos in a rotating layer
Chertovskih, Roman
2015-01-01T23:59:59.000Z
We present a new mechanism for generation of large-scale magnetic field by thermal convection which does not involve the alpha-effect. We consider weakly nonlinear perturbations of space-periodic steady convective magnetic dynamos in a rotating layer that were identified in our previous work. The perturbations have a spatial scale in the horizontal direction that is much larger than the period of the perturbed convective magnetohydrodynamic state. Following the formalism of the multiscale stability theory, we have derived the system of amplitude equations governing the evolution of the leading terms in expansion of the perturbations in power series in the scale ratio. This asymptotic analysis is more involved than in the cases considered earlier, because the kernel of the operator of linearisation has zero-mean neutral modes whose origin lies in the spatial invariance of the perturbed regime, the operator reduced on the generalised kernel has two Jordan normal form blocks of size two, and simplifying symmetri...
J. R. Herrnstein; J. M. Moran; L. J. Greenhill; E. G. Blackman; P. J. Diamond
1998-05-08T23:59:59.000Z
We report VLA 1 sigma upper limits of 1.5% and 3% on the intrinsic circular and linear fractional polarizations, respectively, of the water vapor maser emission 0.2 pc from the central engine of NGC 4258. A corresponding 0.5% upper limit on any Zeeman-splitting-induced circular polarization translates to a 1 sigma upper limit on the parallel, or toroidal, component of the magnetic field of 300 mG. Assuming magnetic and thermal pressure balance in the disk, this magnetic field upper limit corresponds to a model-dependent estimate of the accretion rate through the molecular disk of 10^-1.9 alpha solar masses per year for the case where the magnetic field lies along the line of sight.
Azimuth ambiguity removal and non-linear force-free extrapolation of near-limb magnetic regions
Rudenko, G V; Anfnogentov, S A
2010-01-01T23:59:59.000Z
Possibilities in principle for satisfactory removal of the 180-azimuthal ambiguity in the transverse field of vector magnetograms and the extrapolation of magnetic fields independently of their position on the solar disk are shown. Revealed here is an exact correspondence between the estimated field and the nonpotential loop structure on the limb. The Metropolis's algorithm modified to work in spherical geometry is used to resolve the azimuthal ambiguity. Based on a version of the optimization method from Rudenko and Myshyakov (2009), we use corrected magnetograms as boundary conditions for magnetic field extrapolation in the nonlinear force-free approximation.
Method of making permanent magnets
McCallum, R.W.; Dennis, K.W.; Lograsso, B.K.; Anderson, I.E.
1993-09-07T23:59:59.000Z
A method for making an isotropic permanent magnet comprises atomizing a melt of a rare earth-transition metal alloy (e.g., an Nd--Fe--B alloy enriched in Nd and B) under conditions to produce protectively coated, rapidly solidified, generally spherical alloy particles. Wherein a majority of the particles are produced/size classified within a given size fraction (e.g., 5 to 40 microns diameter) exhibiting optimum as-atomized magnetic properties and subjecting the particles to concurrent elevated temperature and elevated isotropic pressure for a time effective to yield a densified, magnetically isotropic magnet compact having enhanced magnetic properties and mechanical properties. 13 figures.
Magnetic Edge States in Graphene
Gabriela Murguia
2010-08-29T23:59:59.000Z
Magnetic confinement in graphene has been of recent and growing interest because its potential applications in nanotechnology. In particular, the observation of the so called magnetic edge states in graphene has opened the possibility to deepen into the generation of spin currents and its applications in spintronics. We study the magnetic edge states of quasi-particles arising in graphene monolayers due to an inhomogeneous magnetic field of a magnetic barrier in the formalism of the two-dimensional massless Dirac equation. We also show how the solutions of such states in each of both triangular sublattices of the graphene are related through a supersymmetric transformation in the quantum mechanical sense.
Fast superconducting magnetic field switch
Goren, Yehuda (Mountain View, CA); Mahale, Narayan K. (The Woodlands, TX)
1996-01-01T23:59:59.000Z
The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles.
Generation of vector beams with liquid crystal disclination lines
Miha ?an?ula; Miha Ravnik; Slobodan Žumer
2014-08-12T23:59:59.000Z
We report that guiding light beams, ranging from continuous beams to femtosecond pulses, along liquid crystal defect lines can transform them into vector beams with various polarization profiles. Using Finite Difference Time Domain numerical solving of Maxwell equations, we confirm that the defect in the orientational order of the liquid crystal induces a defect in the light field with twice the winding number of the liquid crystal defect, coupling the topological invariants of both fields. For example, it is possible to transform uniformly-polarized light into light with a radial polarization profile. Our approach also correctly yields a zero-intensity region near the defect core, which is always present in areas of discontinuous light polarization or phase. Using circularly polarized incident light, we show that defects with non-integer winding numbers can be obtained, where topological constants are preserved by phase vortices, demonstrating coupling between the light's spin, orbital angular momentum and polarization profile. Further, we find an ultrafast femtosecond laser pulse travelling along a defect line splits into multiple intensity regions, again depending on the defect's winding number, allowing applications in beam steering and filtering. Finally, our approach describing generation of complex optical fields via coupling with topological defect lines in optically birefringent nematic fluids can be easily extended to high-intensity beams that affect nematic ordering.