Offset-free control of constrained linear discrete-time systems subject to persistent
Cambridge, University of
Offset-free control of constrained linear discrete-time systems subject to persistent unmeasured-free control of constrained linear discrete-time systems subject to persistent unmeasured disturbances Gabriele Technical report CUED/F-INFENG/TR.466 September 10, 2003 #12;#12;Offset-free control of constrained linear
Cambridge, University of
Offset-free control of constrained linear discrete-time systems subject to persistent unmeasured, this objective is obtained by designing a dynamic, linear, time-invariant, offset-free controller, and an appropriate domain of attraction for this linear controller is defined. Following this, the linear
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Daley, Thomas M.; Hendrickson, Joel; Queen, John H.
2014-01-01T23:59:59.000Z
A time-lapse Offset Vertical Seismic Profile (OVSP) data set was acquired as part of a subsurface monitoring program for geologic sequestration of CO2. The storage site at Cranfield, near Natchez, Mississippi, is part of a detailed area study (DAS) site for geologic carbon sequestration operated by the U.S. Dept. of Energy’s Southeast Regional Carbon Sequestration Partnership (SECARB). The DAS site includes three boreholes, an injection well and two monitoring wells. The project team selected the DAS site to examine CO2 sequestration multiphase fluid flow and pressure at the interwell scale in a brine reservoir. The time-lapse (TL) OVSP was partmore »of an integrated monitoring program that included well logs, crosswell seismic, electrical resistance tomography and 4D surface seismic. The goals of the OVSP were to detect the CO2 induced change in seismic response, give information about the spatial distribution of CO2 near the injection well and to help tie the high-resolution borehole monitoring to the 4D surface data. The VSP data were acquired in well CFU 31-F1, which is the ~3200 m deep CO2 injection well at the DAS site. A preinjection survey was recorded in late 2009 with injection beginning in December 2009, and a post injection survey was conducted in Nov 2010 following injection of about 250 kT of CO2. The sensor array for both surveys was a 50-level, 3-component, Sercel MaxiWave system with 15 m (49 ft) spacing between levels. The source for both surveys was an accelerated weight drop, with different source trucks used for the two surveys. Consistent time-lapse processing was applied to both data sets. Time-lapse processing generated difference corridor stacks to investigate CO2 induced reflection amplitude changes from each source point. Corridor stacks were used for amplitude analysis to maximize the signal-to-noise ratio (S/N) for each shot point. Spatial variation in reflectivity (used to ‘map’ the plume) was similar in magnitude to the corridor stacks but, due to relatively lower S/N, the results were less consistent and more sensitive to processing and therefore are not presented. We examined the overall time-lapse repeatability of the OVSP data using three methods, the NRMS and Predictability (Pred) measures of Kragh and Christie (2002) and the signal-to-distortion ratio (SDR) method of Cantillo (2011). Because time-lapse noise was comparable to the observed change, multiple methods were used to analyze data reliability. The reflections from the top and base reservoir were identified on the corridor stacks by correlation with a synthetic response generated from the well logs. A consistent change in the corridor stack amplitudes from pre- to post-CO2 injection was found for both the top and base reservoir reflections on all ten shot locations analyzed. In addition to the well-log synthetic response, a finite-difference elastic wave propagation model was built based on rock/fluid properties obtained from well logs, with CO2 induced changes guided by time-lapse crosswell seismic tomography (Ajo-Franklin, et al., 2013) acquired at the DAS site. Time-lapse seismic tomography indicated that two reservoir zones were affected by the flood. The modeling established that interpretation of the VSP trough and peak event amplitudes as reflectivity from the top and bottom of reservoir is appropriate even with possible tuning effects. Importantly, this top/base change gives confidence in an interpretation that these changes arise from within the reservoir, not from bounding lithology. The modeled time-lapse change and the observed field data change from 10 shotpoints are in agreement for both magnitude and polarity of amplitude change for top and base of reservoir. Therefore, we conclude the stored CO2 has been successfully detected and, furthermore, the observed seismic reflection change can be applied to Cranfield’s 4D surface seismic for spatially delineating the CO2/brine interface.« less
Alpay, S. Pamir
Strain induced variations in band offsets and built-in electric fields in InGaN/GaN multiple InxGa1-xN(InGaN)/GaN multilayers on the In composition and misfit strain. The results indicate that for non-polar m-plane configurations with ½1210InGaN//½1210GaN and ½0001InGaN//½0001GaN epitaxial
in each layer reverses. As applications to practical systems, we calculated 1 the piezoelectric fields of piezoelectric fields T. D. Wena and L. P. Xu Department of Physics, North University of China, Taiyuan, Shanxi have been performed to study the effects of piezoelectric fields in superlattice systems. The results
Daley, Thomas M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hendrickson, Joel [Steelhead Geophysical LLC, New Orleans, LA (United States); Queen, John H. [Hi-Q Geophysical Inc., Ponca City, OK (United States)
2014-12-31T23:59:59.000Z
A time-lapse Offset Vertical Seismic Profile (OVSP) data set was acquired as part of a subsurface monitoring program for geologic sequestration of CO_{2}. The storage site at Cranfield, near Natchez, Mississippi, is part of a detailed area study (DAS) site for geologic carbon sequestration operated by the U.S. Dept. of Energy’s Southeast Regional Carbon Sequestration Partnership (SECARB). The DAS site includes three boreholes, an injection well and two monitoring wells. The project team selected the DAS site to examine CO_{2} sequestration multiphase fluid flow and pressure at the interwell scale in a brine reservoir. The time-lapse (TL) OVSP was part of an integrated monitoring program that included well logs, crosswell seismic, electrical resistance tomography and 4D surface seismic. The goals of the OVSP were to detect the CO_{2} induced change in seismic response, give information about the spatial distribution of CO_{2} near the injection well and to help tie the high-resolution borehole monitoring to the 4D surface data. The VSP data were acquired in well CFU 31-F1, which is the ~3200 m deep CO_{2} injection well at the DAS site. A preinjection survey was recorded in late 2009 with injection beginning in December 2009, and a post injection survey was conducted in Nov 2010 following injection of about 250 kT of CO_{2}. The sensor array for both surveys was a 50-level, 3-component, Sercel MaxiWave system with 15 m (49 ft) spacing between levels. The source for both surveys was an accelerated weight drop, with different source trucks used for the two surveys. Consistent time-lapse processing was applied to both data sets. Time-lapse processing generated difference corridor stacks to investigate CO_{2} induced reflection amplitude changes from each source point. Corridor stacks were used for amplitude analysis to maximize the signal-to-noise ratio (S/N) for each shot point. Spatial variation in reflectivity (used to ‘map’ the plume) was similar in magnitude to the corridor stacks but, due to relatively lower S/N, the results were less consistent and more sensitive to processing and therefore are not presented. We examined the overall time-lapse repeatability of the OVSP data using three methods, the NRMS and Predictability (Pred) measures of Kragh and Christie (2002) and the signal-to-distortion ratio (SDR) method of Cantillo (2011). Because time-lapse noise was comparable to the observed change, multiple methods were used to analyze data reliability. The reflections from the top and base reservoir were identified on the corridor stacks by correlation with a synthetic response generated from the well logs. A consistent change in the corridor stack amplitudes from pre- to post-CO_{2} injection was found for both the top and base reservoir reflections on all ten shot locations analyzed. In addition to the well-log synthetic response, a finite-difference elastic wave propagation model was built based on rock/fluid properties obtained from well logs, with CO_{2} induced changes guided by time-lapse crosswell seismic tomography (Ajo-Franklin, et al., 2013) acquired at the DAS site. Time-lapse seismic tomography indicated that two reservoir zones were affected by the flood. The modeling established that interpretation of the VSP trough and peak event amplitudes as reflectivity from the top and bottom of reservoir is appropriate even with possible tuning effects. Importantly, this top/base change gives confidence in an interpretation that these changes arise from within the reservoir, not from bounding lithology. The modeled time-lapse change and the observed field data change from 10 shotpoints are in agreement for both magnitude and polarity of amplitude change for top and base of reservoir. Therefore, we conclude the stored CO_{2} has been successfully detected and, furthermore, the observed seismic reflection change can
The past and future of greenhouse gas offset projects
Trexler, M.C.; Kosloff, L.H. [Trexler and Associates, Inc., Portland, OR (United States)
1997-12-31T23:59:59.000Z
Researchers now have almost 10 years of experience with on-the-ground carbon offset projects for climate change mitigation purposes. The field is evolving from one driven primarily by public and governmental relations, to one driven by companies` perceived need to adapt to anticipated national and international regulation of greenhouse gas emissions. Offset project participants are seeking to identify offset opportunities, come up the regulatory and technical learning curves, and identify new market opportunities. Offset projects being implemented today can be evaluated through several lenses including offset performance and benefit quantification, cost-effectiveness, and political and environmental acceptability. Careful evaluation of existing offset experience is important in order to guide national and international policy development. This paper will review the history and trends of offset project development, use existing experience to identify advantages and disadvantages associated with different offsets, and identify lessons that can guide future project development. The lead author carried out the CO{sub 2} benefit analysis for the first offset project (AES Corp.`s CARE Guatemala reforestation project), and has developed and evaluated dozens of domestic and international offset projects and proposals. The authors` company is currently implementing more than a half-dozen offset projects and they are intimately involved in ongoing technical and policy development of the field.
Sahin, Cenk
2012-08-31T23:59:59.000Z
In this work we compute the capacities and the pragmatic capacities of military-standard shaped-offset quadrature phase-shift keying (SOQPSK-MIL) and aeronautical telemetry SOQPSK (SOQPSK-TG). In the pragmatic approach, SOQPSK is treated as a...
Noncommutative Time in Quantum Field Theory
Tapio Salminen; Anca Tureanu
2011-07-19T23:59:59.000Z
We analyze, starting from first principles, the quantization of field theories, in order to find out to which problems a noncommutative time would possibly lead. We examine the problem in the interaction picture (Tomonaga-Schwinger equation), the Heisenberg picture (Yang-Feldman-K\\"all\\'{e}n equation) and the path integral approach. They all indicate inconsistency when time is taken as a noncommutative coordinate. The causality issue appears as the key aspect, while the unitarity problem is subsidiary. These results are consistent with string theory, which does not admit a time-space noncommutative quantum field theory as its low-energy limit, with the exception of light-like noncommutativity.
Offset-free Receding Horizon Control of Constrained Linear Systems subject to
Cambridge, University of
Offset-free Receding Horizon Control of Constrained Linear Systems subject to Time/F-INFENG/TR.468 November 4, 2003 #12;Offset-free Receding Horizon Control of Constrained Linear Systems subject and offset-free control of con- strained, linear time-invariant systems in the presence of time
Agricultural Mitigation and Offsets: Policy Issues, Progress
Agricultural Mitigation and Offsets: Policy Issues, Progress Purdue Climate Change Research Center, 2010 #12;Agricultural Mitigation and Offsets: Policy Issues, Progress Presentation Overview: Global Climate Change...and Agriculture Policy Landscape: US and International Agricultural Offsets and Policy
Analysis of amplitude versus offset
Du, Xiaotao
1990-01-01T23:59:59.000Z
: Geophysics ANALYSIS OF AMPLITUDE VERSUS OFFSET A Thesis by XIAOTAO DU Approved as to style and content by: T~ RY VV. SP CER 'r of Co JOEL S. %ATKINS (Member) RONALD M. BRIMHALL (Member) OEL S. tVATKINS (Head of Department) August 1990 ABSTRACT... Analysis of Amplitude versus Offset. (August 1990) Xiaotao Du, B. S. , East China, Petroleum Institute Chair of Advisory Committee: Terry W. Spencer Conditions are described under winch noise-free AVO data, can be inverted for the medium parameters...
Mean Field Variational Approximations in Continuous-Time Markov Processes
Friedman, Nir
Mean Field Variational Approximations in Continuous-Time Markov Processes A thesis submitted Processes . . . . . . . . . . . . . . . . . . . 18 2.3 Continuous Time Markov Processes-component Representation - Continuous Time Bayesian Networks . 24 2.3.3 Inference in Continuous Time Markov Processes
Continuous Time Finite State Mean Field Games
Gomes, Diogo A., E-mail: dgomes@math.ist.utl.pt [Instituto Superior Tecnico, Center for Mathematical Analysis, Geometry, and Dynamical Systems, Departamento de Matematica (Portugal); Mohr, Joana, E-mail: joana.mohr@ufrgs.br; Souza, Rafael Rigao, E-mail: rafars@mat.ufrgs.br [UFRGS, Instituto de Matematica (Brazil)
2013-08-01T23:59:59.000Z
In this paper we consider symmetric games where a large number of players can be in any one of d states. We derive a limiting mean field model and characterize its main properties. This mean field limit is a system of coupled ordinary differential equations with initial-terminal data. For this mean field problem we prove a trend to equilibrium theorem, that is convergence, in an appropriate limit, to stationary solutions. Then we study an N+1-player problem, which the mean field model attempts to approximate. Our main result is the convergence as N{yields}{infinity} of the mean field model and an estimate of the rate of convergence. We end the paper with some further examples for potential mean field games.
Space-Time Noncommutative Field Theories And Unitarity
Jaume Gomis; Thomas Mehen
2000-08-01T23:59:59.000Z
We study the perturbative unitarity of noncommutative scalar field theories. Field theories with space-time noncommutativity do not have a unitary S-matrix. Field theories with only space noncommutativity are perturbatively unitary. This can be understood from string theory, since space noncommutative field theories describe a low energy limit of string theory in a background magnetic field. On the other hand, there is no regime in which space-time noncommutative field theory is an appropriate description of string theory. Whenever space-time noncommutative field theory becomes relevant massive open string states cannot be neglected.
Reservoir offset models for Radiocarbon calibration
Nicholls, Geoff
Reservoir offset models for Radiocarbon calibration Martin Jones Department of Anthropology mdj offset is to enable the application of calibration data (Âµ(), e.g. Stuiver et al. 1998) developed for one are not independent. However, the standard procedure for incorporating offset error into calibrated distributions
Space-Time Galerkin Projection of Electro-Magnetic Fields
Wang, Zifu; Hofmann, Heath
2015-01-01T23:59:59.000Z
Spatial Galerkin projection transfers fields between different meshes. In the area of finite element analysis of electromagnetic fields, it provides great convenience for remeshing, multi-physics, domain decomposition methods, etc. In this paper, a space-time Galerkin projection is developed in order to transfer fields between different spatial and temporal discretization bases.
Linear electric field time-of-flight ion mass spectrometer
Funsten, Herbert O. (Los Alamos, NM); Feldman, William C. (Los Alamos, NM)
2008-06-10T23:59:59.000Z
A linear electric field ion mass spectrometer having an evacuated enclosure with means for generating a linear electric field located in the evacuated enclosure and means for injecting a sample material into the linear electric field. A source of pulsed ionizing radiation injects ionizing radiation into the linear electric field to ionize atoms or molecules of the sample material, and timing means determine the time elapsed between ionization of atoms or molecules and arrival of an ion out of the ionized atoms or molecules at a predetermined position.
Evaluating transport coefficients in real time thermal field theory
S. Mallik; Sourav Sarkar
2012-11-12T23:59:59.000Z
Transport coefficients in a hadronic gas have been calculated earlier in the imaginary time formulation of thermal field theory. The steps involved are to relate the defining retarded correlation function to the corresponding time-ordered one and to evaluate the latter in the conventional perturbation expansion. Here we carry out both the steps in the real time formulation.
Time evolution of negative binomial optical field in diffusion channel
Liu Tang-Kun; Wu Pan-Pan; Shan Chuan-Jia; Liu Ji-Bing; Fan Hong-Yi
2015-04-17T23:59:59.000Z
We find time evolution law of negative binomial optical field in diffusion channel. We reveal that by adjusting the diffusion parameter, photon number can controlled. Therefore, the diffusion process can be considered a quantum controlling scheme through photon addition.
Offset-free Receding Horizon Control of Constrained Linear Gabriele Pannocchia1 Eric C. Kerrigan2
Cambridge, University of
Offset-free Receding Horizon Control of Constrained Linear Systems Gabriele Pannocchia1 Eric C stability and offset-free control of constrained linear systems in the presence of time-varying setpoints-free controller and computing an appropriate domain of attraction for this controller. The linear (unconstrained
Multi-time wave functions for quantum field theory
Petrat, Sören, E-mail: petrat@math.lmu.de [Mathematisches Institut, Ludwig-Maximilians-Universität, Theresienstr. 39, 80333 München (Germany); Tumulka, Roderich, E-mail: tumulka@math.rutgers.edu [Department of Mathematics, Rutgers University, 110 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States)
2014-06-15T23:59:59.000Z
Multi-time wave functions such as ?(t{sub 1},x{sub 1},…,t{sub N},x{sub N}) have one time variable t{sub j} for each particle. This type of wave function arises as a relativistic generalization of the wave function ?(t,x{sub 1},…,x{sub N}) of non-relativistic quantum mechanics. We show here how a quantum field theory can be formulated in terms of multi-time wave functions. We mainly consider a particular quantum field theory that features particle creation and annihilation. Starting from the particle–position representation of state vectors in Fock space, we introduce multi-time wave functions with a variable number of time variables, set up multi-time evolution equations, and show that they are consistent. Moreover, we discuss the relation of the multi-time wave function to two other representations, the Tomonaga–Schwinger representation and the Heisenberg picture in terms of operator-valued fields on space–time. In a certain sense and under natural assumptions, we find that all three representations are equivalent; yet, we point out that the multi-time formulation has several technical and conceptual advantages. -- Highlights: •Multi-time wave functions are manifestly Lorentz-covariant objects. •We develop consistent multi-time equations with interaction for quantum field theory. •We discuss in detail a particular model with particle creation and annihilation. •We show how multi-time wave functions are related to the Tomonaga–Schwinger approach. •We show that they have a simple representation in terms of operator valued fields.
Electromagnetic Field Quantization in Time-Dependent Dielectric Media
Xiao-Min Bei; Zhong-Zhu Liu
2011-04-18T23:59:59.000Z
We present a Gupta-Bleuler quantization scheme for the electromagnetic field in time-dependent dielectric media. Starting from the Maxwell equations, a generalization of the Lorentz gauge condition adapted to time varying dielectrics is derived. Using this gauge, a Gupta-Bleuler approach to quantize all polarizations of the radiation field and the corresponding constraint condition are introduced. This new approach is different from the quantized electromagnetic field in vacuum in the sense that here the contributions of unphysical photons cannot be thoroughly eliminated, which further lead to a surface charge density. Finally, a discussion of potential experimental tests and possible implication is also made.
Remarks on Time-Space Noncommutative Field Theories
L. Alvarez-Gaume; J. L. F. Barbon; R. Zwicky
2001-03-09T23:59:59.000Z
We propose a physical interpretation of the perturbative breakdown of unitarity in time-like noncommutative field theories in terms of production of tachyonic particles. These particles may be viewed as a remnant of a continuous spectrum of undecoupled closed-string modes. In this way, we give a unified view of the string-theoretical and the field-theoretical no-go arguments against time-like noncommutative theories. We also perform a quantitative study of various locality and causality properties of noncommutative field theories at the quantum level.
Time-Periodic Solutions of the Einstein's Field Equations II
De-Xing Kong; Kefeng Liu; Ming Shen
2008-07-31T23:59:59.000Z
In this paper, we construct several kinds of new time-periodic solutions of the vacuum Einstein's field equations whose Riemann curvature tensors vanish, keep finite or take the infinity at some points in these space-times, respectively. The singularities of these new time-periodic solutions are investigated and some new physical phenomena are found. The applications of these solutions in modern cosmology and general relativity can be expected.
Topological Field Theory of Time-Reversal Invariant Insulators
Qi, Xiao-Liang; Hughes, Taylor; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.
2010-03-19T23:59:59.000Z
We show that the fundamental time reversal invariant (TRI) insulator exists in 4 + 1 dimensions, where the effective field theory is described by the 4 + 1 dimensional Chern-Simons theory and the topological properties of the electronic structure is classified by the second Chern number. These topological properties are the natural generalizations of the time reversal breaking (TRB) quantum Hall insulator in 2 + 1 dimensions. The TRI quantum spin Hall insulator in 2 + 1 dimensions and the topological insulator in 3 + 1 dimension can be obtained as descendants from the fundamental TRI insulator in 4 + 1 dimensions through a dimensional reduction procedure. The effective topological field theory, and the Z{sub 2} topological classification for the TRI insulators in 2+1 and 3+1 dimensions are naturally obtained from this procedure. All physically measurable topological response functions of the TRI insulators are completely described by the effective topological field theory. Our effective topological field theory predicts a number of novel and measurable phenomena, the most striking of which is the topological magneto-electric effect, where an electric field generates a magnetic field in the same direction, with an universal constant of proportionality quantized in odd multiples of the fine structure constant {alpha} = e{sup 2}/hc. Finally, we present a general classification of all topological insulators in various dimensions, and describe them in terms of a unified topological Chern-Simons field theory in phase space.
CARBON OFFSETTING IN A TOURSIM CONTEXT: WHISTLER BC
CARBON OFFSETTING IN A TOURSIM CONTEXT: WHISTLER BC by Katie von Gaza Bachelor of Environmental: Carbon offsetting in a Tourism Context: Whistler, BC. Project No.: 471 Examining Committee: Chair 2.2 Carbon Offsetting
Extended gyrokinetic field theory for time-dependent magnetic confinement fields
Sugama, H.; Watanabe, T.-H.; Nunami, M. [National Institute for Fusion Science, Toki 509-5292 (Japan)] [National Institute for Fusion Science, Toki 509-5292 (Japan)
2014-01-15T23:59:59.000Z
A gyrokinetic system of equations for turbulent toroidal plasmas in time-dependent axisymmetric background magnetic fields is derived from the variational principle. Besides governing equations for gyrocenter distribution functions and turbulent electromagnetic fields, the conditions which self-consistently determine the background magnetic fields varying on a transport time scale are obtained by using the Lagrangian, which includes the constraint on the background fields. Conservation laws for energy and toroidal angular momentum of the whole system in the time-dependent background magnetic fields are naturally derived by applying Noether's theorem. It is shown that the ensemble-averaged transport equations of particles, energy, and toroidal momentum given in the present work agree with the results from the conventional recursive formulation with the WKB representation except that collisional effects are disregarded here.
Financing Residential Energy Efficiency with Carbon Offsets Transcript...
Financing Residential Energy Efficiency with Carbon Offsets Transcript Financing Residential Energy Efficiency with Carbon Offsets Transcript This document contains the transcript...
FIELD-BASED TECHNOLOGY EDUCATION: JUST IN TIME TECHNOLOGY TRAINING
Larkin, Teresa L.
FIELD-BASED TECHNOLOGY EDUCATION: JUST IN TIME TECHNOLOGY TRAINING Sarah Irvine Belson1 and Teresa, Audio Technology, and Physics, American University, 4400 Massachusetts Ave. NW, Washington, DC 20016, tlarkin@american.edu Abstract -- This paper outlines the current status of technology integration
Time-aging time-stress superposition in soft glass under tensile deformation field
Asima Shaukat; Ashutosh Sharma; Yogesh M. Joshi
2010-06-10T23:59:59.000Z
We have studied the tensile deformation behaviour of thin films of aging aqueous suspension of Laponite, a model soft glassy material, when subjected to a creep flow field generated by a constant engineering normal stress. Aqueous suspension of Laponite demonstrates aging behaviour wherein it undergoes time dependent enhancement of its elastic modulus as well as its characteristic relaxation time. However, under application of the normal stress, the rate of aging decreases and in the limit of high stress, the aging stops with the suspension now undergoing a plastic deformation. Overall, it is observed that the aging that occurs over short creep times at small normal stresses is same as the aging that occurs over long creep times at large normal stresses. This observation allows us to suggest an aging time - process time - normal stress superposition principle, which can predict rheological behaviour at longer times by carrying out short time tests.
Space-time as a discrete field noncommutative causal network
G. L. Stavraki
2009-07-02T23:59:59.000Z
The necessity of rejecting the numerical model of geometrical extension is postulated on the basis of the idea of identity of space-time and physical vacuum. An attempt is made to define space-time not via the concept of manifold, but via the store of physical functions defined on it. The new description is based on the commutator representation of the causal structure of operator field theory. It is not the world point, but a universal field supermatrix complex U that is assumed to be the carrier of possible local events. This complex involves a complete set of Heisenberg local field operators together with their spin-group bases in the Fermi-field representation. The fundamental element of the extension is described in the model by the equation of a special commutator algebra closed on two such local complexes U_1 and U_2 "nearest" in the two-sided light-like connection and linked by a single virtual field interaction vertex. The discrete character of the constructed "quantum proximity" equation containing the gravitational constant is associated with the existence of local curvature on the Planck scale. Algebraic closed-ness of the basic equation suggests that the charge symmetry group should be group E_6 with non-standard representations of the fermion and scalar fields. On the basis of the calculated U expression we propose an effective superinvariant Lagrangian with fixed coefficients on the near-Planck scale, from which one can in principle try to obtain a low-energy limit for comparison with the real world.
Carbon offsets, the CDM, and sustainable development
for research on post-2012 climate policy at the British Tyndall Centre for Climate Change, and chairsChapter 11 Carbon offsets, the CDM, and sustainable development Diana M. Liverman Diana M. Liverman of the ESSP. Her research has focused on the human dimensions of global environmental change, especially
Severino, Clizia Tecla; Silari, Marco
Real-time measurement of radon activity and mixed radiation fields characterization with silicon pixel detector
Quantum Space-Time and Noncommutative Gauge Field Theories
Sami Saxell
2009-09-17T23:59:59.000Z
The three original publications in this thesis encompass various aspects in the still developing area of noncommutative quantum field theory, ranging from fundamental concepts to model building. One of the key features of noncommutative space-time is the apparent loss of Lorentz invariance that has been addressed in different ways in the literature. One recently developed approach is to eliminate the Lorentz violating effects by integrating over the parameter of noncommutativity. Fundamental properties of such theories are investigated in this thesis. Another issue addressed is model building, which is difficult in the noncommutative setting due to severe restrictions on the possible gauge symmetries imposed by the noncommutativity of the space-time. Possible ways to relieve these restrictions are investigated and applied and a noncommutative version of the Minimal Supersymmetric Standard Model is presented. While putting the results obtained in the three original publications into their proper context, the introductory part of this thesis aims to provide an overview of the present situation in the field.
Continuous space-time symmetries in a lattice field theory
H. B. Thacker
1998-09-18T23:59:59.000Z
For purposes of regularization as well as numerical simulation, the discretization of Lorentz invariant continuum field theories on a space-time lattice is often convenient. In general, this discretization destroys the rotational or Lorentz-frame independence of the theory, which is only recovered in the continuum limit. The Baxter 8-vertex model may be interpreted as a particular discretization of a self-interacting massive Dirac fermion theory in two dimensions (the massive Thirring model). Here it is shown that, in the 8-vertex/massive Thirring model, the Lorentz frame independence of the theory remains undisturbed on the lattice. The only effect of the discretization is to compactify the manifold of Lorentz frames. The relationship between this lattice Lorentz symmetry and the Yang-Baxter relations is discussed.
Seismic Amplitude Versus Offset (AVO) Character of Geopressured Transition Zones
on well logs from sealed transitions n demonstrate their unusual AVO character. A long-offset COCORP
Visualization of time-dependent seismic vector fields with glyphs
McQuinn, Emmett
2010-01-01T23:59:59.000Z
tensor fields in geomechanics. Visualization Conference,single timestep of a geomechanics simulation. Glyph geometry
Developments in deep brain stimulation using time dependent magnetic fields
Crowther, L.J.; Nlebedim, I.C.; Jiles, D.C.
2012-03-07T23:59:59.000Z
The effect of head model complexity upon the strength of field in different brain regions for transcranial magnetic stimulation (TMS) has been investigated. Experimental measurements were used to verify the validity of magnetic field calculations and induced electric field calculations for three 3D human head models of varying complexity. Results show the inability for simplified head models to accurately determine the site of high fields that lead to neuronal stimulation and highlight the necessity for realistic head modeling for TMS applications.
The sensitivity of patient specific IMRT QC to systematic MLC leaf bank offset errors
Rangel, Alejandra; Palte, Gesa; Dunscombe, Peter [Department of Medical Physics, Tom Baker Cancer Centre, 1331-29 Street NW, Calgary, Alberta T2N 4N2, Canada and Department of Physics and Astronomy, University of Calgary, 2500 University Drive North West, Calgary, Alberta T2N 1N4 (Canada); Department of Medical Physics, Tom Baker Cancer Centre, 1331-29 Street NW, Calgary, Alberta T2N 4N2 (Canada); Department of Medical Physics, Tom Baker Cancer Centre, 1331-29 Street NW, Calgary, Alberta T2N 4N2 (Canada); Department of Physics and Astronomy, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4 (Canada) and Department of Oncology, Tom Baker Cancer Centre, 1331-29 Street NW, Calgary, Alberta T2N 4N2 (Canada)
2010-07-15T23:59:59.000Z
Purpose: Patient specific IMRT QC is performed routinely in many clinics as a safeguard against errors and inaccuracies which may be introduced during the complex planning, data transfer, and delivery phases of this type of treatment. The purpose of this work is to evaluate the feasibility of detecting systematic errors in MLC leaf bank position with patient specific checks. Methods: 9 head and neck (H and N) and 14 prostate IMRT beams were delivered using MLC files containing systematic offsets ({+-}1 mm in two banks, {+-}0.5 mm in two banks, and 1 mm in one bank of leaves). The beams were measured using both MAPCHECK (Sun Nuclear Corp., Melbourne, FL) and the aS1000 electronic portal imaging device (Varian Medical Systems, Palo Alto, CA). Comparisons with calculated fields, without offsets, were made using commonly adopted criteria including absolute dose (AD) difference, relative dose difference, distance to agreement (DTA), and the gamma index. Results: The criteria most sensitive to systematic leaf bank offsets were the 3% AD, 3 mm DTA for MAPCHECK and the gamma index with 2% AD and 2 mm DTA for the EPID. The criterion based on the relative dose measurements was the least sensitive to MLC offsets. More highly modulated fields, i.e., H and N, showed greater changes in the percentage of passing points due to systematic MLC inaccuracy than prostate fields. Conclusions: None of the techniques or criteria tested is sufficiently sensitive, with the population of IMRT fields, to detect a systematic MLC offset at a clinically significant level on an individual field. Patient specific QC cannot, therefore, substitute for routine QC of the MLC itself.
Miller, William H.
Quantum time evolution in time-dependent fields and time-independent reactive is suggested for accurate large-scale quantum dynamics simulations. The time-dependent Schro¨dinger equation with finite time-dependent interaction terms is replaced by an inhomogeneous equation with imaginary boundary
Carbon Offsets for Forestry and Bioenergy: Researching Opportunities...
Researching Opportunities for Poor Rural Communities Jump to: navigation, search Name Carbon Offsets for Forestry and Bioenergy: Researching Opportunities for Poor Rural...
Divergence and Lifecycle Offsets in Product Families with Commonality
de Weck, Olivier L.
of seven complex product families that span the aerospace, automotive, semiconductor capital equipment: commonality; platform strategy; platform management; product development; divergence; lifecycle offsets 1
1 18 June 2009 Thermal excitation of large charge offsets
Paris-Sud XI, Université de
1 18 June 2009 Thermal excitation of large charge offsets in a single-Cooper-pair transistor L.R.Simkins
Time Evolution of Electric Fields in CDMS Detectors
Leman, S.W.; /MIT, MKI; Brandt, D.; Brink, P.L.; /SLAC; Cabrera, B.; /Stanford U., Phys. Dept.; Chagani, H.; Cherry, M.; Cushman, P.; /Minnesota U.; Do Couto E.Silva, E.; /SLAC; Doughty, T.; /UC, Berkeley; Figueroa-Feliciano, E.; /MIT, MKI; Mandic, V.; /Minnesota U.; McCarthy, K.A.; /MIT, MKI; Mirabolfathi, N.; /UC, Berkeley; Pyle, M.; /Stanford U., Phys. Dept.; Reisetter, A.; /St. Olaf Coll.; Resch, R.; /SLAC; Sadoulet, B.; /Stanford U., Phys. Dept.; Serfass, B.; Sundqvist, K.M.; /UC, Berkeley; Tomada, A.; /SLAC; Young, B.A.; /Minnesota U.
2012-06-06T23:59:59.000Z
The Cryogenic Dark Matter Search (CDMS) utilizes large mass, 3-inch diameter x 1-inch thick target masses as particle detectors. The target is instrumented with both phonon and ionization sensors, the later providing a {approx}1 V cm{sup -1} electric field in the detector bulk. Cumulative radiation exposure which creates {approx}200 x 10{sup 6} electron-hole pairs could be sufficient to produce a comparable reverse field in the detector thereby degrading the ionization channel performance, if it was not shielded by image charges on the electrodes. To study this, the existing CDMS detector Monte Carlo has been modified to allow for an event by event evolution of the bulk electric field, in three spatial dimensions. Surprisingly, this simple model is not sufficient to explain the degradation of detector performance. Our most recent results and interpretation are discussed.
Path integral for space-time noncommutative field theory
Fujikawa, Kazuo [Institute of Quantum Science, College of Science and Technology, Nihon University, Chiyoda-ku, Tokyo 101-8308 (Japan)
2004-10-15T23:59:59.000Z
The path integral for space-time noncommutative theory is formulated by means of Schwinger's action principle, which is based on the equations of motion and a suitable ansatz of asymptotic conditions. The resulting path integral has essentially the same physical basis as the Yang-Feldman formulation. It is first shown that higher derivative theories are neatly dealt with by the path integral formulation, and the underlying canonical structure is recovered by the Bjorken-Johnson-Low (BJL) prescription from correlation functions defined by the path integral. A simple theory which is nonlocal in time is then analyzed for an illustration of the complications related to quantization, unitarity, and positive energy conditions. From the viewpoint of the BJL prescription, the naive quantization in the interaction picture is justified for space-time noncommutative theory but not for the simple theory nonlocal in time. We finally show that the perturbative unitarity and the positive energy condition, in the sense that only the positive energy flows in the positive time direction for any fixed time slice in space-time, are not simultaneously satisfied for space-time noncommutative theory by the known methods of quantization.
Dependence of Brownian and Néel relaxation times on magnetic field strength
Deissler, Robert J., E-mail: rjd42@case.edu; Wu, Yong; Martens, Michael A. [Department of Physics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)] [Department of Physics, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106 (United States)
2014-01-15T23:59:59.000Z
Purpose: In magnetic particle imaging (MPI) and magnetic particle spectroscopy (MPS) the relaxation time of the magnetization in response to externally applied magnetic fields is determined by the Brownian and Néel relaxation mechanisms. Here the authors investigate the dependence of the relaxation times on the magnetic field strength and the implications for MPI and MPS. Methods: The Fokker–Planck equation with Brownian relaxation and the Fokker–Planck equation with Néel relaxation are solved numerically for a time-varying externally applied magnetic field, including a step-function, a sinusoidally varying, and a linearly ramped magnetic field. For magnetic fields that are applied as a step function, an eigenvalue approach is used to directly calculate both the Brownian and Néel relaxation times for a range of magnetic field strengths. For Néel relaxation, the eigenvalue calculations are compared to Brown's high-barrier approximation formula. Results: The relaxation times due to the Brownian or Néel mechanisms depend on the magnitude of the applied magnetic field. In particular, the Néel relaxation time is sensitive to the magnetic field strength, and varies by many orders of magnitude for nanoparticle properties and magnetic field strengths relevant for MPI and MPS. Therefore, the well-known zero-field relaxation times underestimate the actual relaxation times and, in particular, can underestimate the Néel relaxation time by many orders of magnitude. When only Néel relaxation is present—if the particles are embedded in a solid for instance—the authors found that there can be a strong magnetization response to a sinusoidal driving field, even if the period is much less than the zero-field relaxation time. For a ferrofluid in which both Brownian and Néel relaxation are present, only one relaxation mechanism may dominate depending on the magnetic field strength, the driving frequency (or ramp time), and the phase of the magnetization relative to the applied magnetic field. Conclusions: A simple treatment of Néel relaxation using the common zero-field relaxation time overestimates the relaxation time of the magnetization in situations relevant for MPI and MPS. For sinusoidally driven (or ramped) systems, whether or not a particular relaxation mechanism dominates or is even relevant depends on the magnetic field strength, the frequency (or ramp time), and the phase of the magnetization relative to the applied magnetic field.
Report of the Offset Drilling Workshop Ocean Drilling Program
Report of the Offset Drilling Workshop held at Ocean Drilling Program Texas A&M University College Need for an Engineering Leg 35 Realistic Strategies for Offset Drilling 37 Appendix 1 Workshop (Leg 153) 21 Figure 4 "Rig Floor Perception" of Generic Boreholes Drilled During Leg 153 22 Figure 5
EXPLAINING THE PRICE OF VOLUNTARY CARBON OFFSETS MARC N. CONTE
Kotchen, Matthew J.
EXPLAINING THE PRICE OF VOLUNTARY CARBON OFFSETS MARC N. CONTE Stanford University, Stanford, CA matthew.kotchen@yale.edu This paper identifies factors that explain the large variability in the price of voluntary carbon offsets. We estimate hedonic price functions using a variety of provider- and project
Influence of Time-Varying External Magnetic Fields on Trapped Fields in Bulk Superconductors
Zou, Jin; Ainslie, Mark D.; Hu, Di; Cardwell, David A.
2014-12-12T23:59:59.000Z
Large, single-grain bulk high-temperature superconductors (HTS) can trap magnetic fields over 17 T below 30 K and up to 3 T at 77 K, and have significant potential to replace permanent magnets, the fields from which are limited to significantly less...
Linear electronic field time-of-flight ion mass spectrometers
Funsten, Herbert O. (Los Alamos, NM)
2010-08-24T23:59:59.000Z
Time-of-flight mass spectrometer comprising a first drift region and a second drift region enclosed within an evacuation chamber; a means of introducing an analyte of interest into the first drift region; a pulsed ionization source which produces molecular ions from said analyte of interest; a first foil positioned between the first drift region and the second drift region, which dissociates said molecular ions into constituent atomic ions and emits secondary electrons; an electrode which produces secondary electrons upon contact with a constituent atomic ion in second drift region; a stop detector comprising a first ion detection region and a second ion detection region; and a timing means connected to the pulsed ionization source, to the first ion detection region, and to the second ion detection region.
How Much Energy Have Real Fields Time and Space in Multifractal Universe?
L. Ya. Kobelev
2000-11-16T23:59:59.000Z
On the base of multifractal theory of time and space (see \\cite{kob1}-\\cite{kob16}) in this paper shown presence in every space and time volumes of real space and time fields a huge supply of energy . In the multifractal Universe every space volume or time interval possesses by huge amount of energy($\\sim10^{60}cm^{3}$) and we discuss the problem is it possible this new for mankind sorts of energy to extract. Contents: 1. Introduction 2. What are Energy Densities of Real Space and Time Fields in Multifractal Universe? 3. How Much Energy Space and Time Continually Lose?
Wick rotation for quantum field theories on degenerate Moyal space(-time)
Grosse, Harald; Lechner, Gandalf [Department of Physics, University of Vienna, 1090 Vienna (Austria)] [Department of Physics, University of Vienna, 1090 Vienna (Austria); Ludwig, Thomas [Max-Planck-Institute for Mathematics in the Sciences, 04103 Leipzig (Germany) [Max-Planck-Institute for Mathematics in the Sciences, 04103 Leipzig (Germany); Institute for Theoretical Physics, University of Leipzig, 04009 Leipzig (Germany); Verch, Rainer [Institute for Theoretical Physics, University of Leipzig, 04009 Leipzig (Germany)] [Institute for Theoretical Physics, University of Leipzig, 04009 Leipzig (Germany)
2013-02-15T23:59:59.000Z
In this paper the connection between quantum field theories on flat noncommutative space(-times) in Euclidean and Lorentzian signature is studied for the case that time is still commutative. By making use of the algebraic framework of quantum field theory and an analytic continuation of the symmetry groups which are compatible with the structure of Moyal space, a general correspondence between field theories on Euclidean space satisfying a time zero condition and quantum field theories on Moyal Minkowski space is presented ('Wick rotation'). It is then shown that field theories transferred to Moyal space(-time) by Rieffel deformation and warped convolution fit into this framework, and that the processes of Wick rotation and deformation commute.
Azimuthal Offset-Dependent Attributes (AVO And FVO) Applied To Fracture Detection
Shen, Feng
1999-01-01T23:59:59.000Z
Using the amplitude versus offset (AVO) and the frequency versus offset (FVO) information, the diagnostic ability of P-wave seismic data in fracture detection is investigated. The offset-dependent attributes (AVO and FVO) ...
SPECTRAL DECOMPOSITION APPLIED TO TIME-LAPSE SEISMIC INTERPRETATION AT RULISON FIELD,
SPECTRAL DECOMPOSITION APPLIED TO TIME-LAPSE SEISMIC INTERPRETATION AT RULISON FIELD, GARFIELD focuses on the application of this technique to time-lapse seismic interpretation using nine-component 4D-lapse interpretation through a cross equalization process. I analyzed two time-lapse pairs of seismic surveys: 2003
McCarl, Bruce A.
support for allocating resources to alter the market mix of carbon sequestration and direct emission carbon sequestration practices also influence the environment by for example reducing erosion1 Sequestration Offsets versus Direct Emission Reductions: Consideration of Environmental
29 April 2010 The What, Why, and How of Offsets
Examples of Offset Projects Biomass and Waste mgt Small Scale Hydropower Animal Waste Biodigestors Landfill Methane Agricultural Biodigestors #12;© Det Norske Veritas AS. All rights reserved. Thursday, 29 April
Missouri: EERE Funds Help Offset City Electricity Expenses |...
produce between 90,000 and 100,000 kilowatt-hours (kWh) annually. This renewable energy production will offset 10% of the facility's total electricity usage (just over 12,000...
Notes on Gauss law applied for time varying electric field in vacuum
Zhakatayev, Altay
2015-01-01T23:59:59.000Z
Gauss's law in integral form states that closed surface integral of electric field is proportional to net charge present within the volume bounded by this closed surface. Gauss's law in differential form states that divergence of electric field is proportional to charge's volume density. From Gauss's law it is concluded that in vacuum, where no electric charges are present, divergence of electric field and closed surface integral of electric field are zero. In this paper we make an attempt to theoretically prove that for time-varying electric fields Gauss's law is not valid. In other words, for time-varying electric field even in vacuum divergence of electric field and closed surface integral of electric field are non-zero. We do this by considering simple sinusoidal motion of the charge and then by calculating closed surface integral at specific time of time-varying electric field due to charge motion. Results show that for charges at still and at motion with constant velocity Gauss's law is valid. However f...
N. Seiberg; L. Susskind; N. Toumbas
2000-05-04T23:59:59.000Z
Searching for space/time noncommutativity we reconsider open strings in a constant background electric field. The main difference between this situation and its magnetic counterpart is that here there is a critical electric field beyond which the theory does not make sense. We show that this critical field prevents us from finding a limit in which the theory becomes a field theory on a noncommutative spacetime. However, an appropriate limit toward the critical field leads to a novel noncritical string theory on a noncommutative spacetime.
Time-odd mean fields in covariant density functional theory I. Non-rotating systems
A. V. Afanasjev; H. Abusara
2010-10-09T23:59:59.000Z
Time-odd mean fields (nuclear magnetism) are analyzed in the framework of covariant density functional theory (CDFT). It is shown that they always provide additional binding to the binding energies of odd-mass nuclei. This additional binding only weakly depends on the RMF parametrization reflecting good localization of the properties of time-odd mean fields in CDFT. The underlying microscopic mechanism is discussed in detail. Time-odd mean fields affect odd-even mass differences. However, our analysis suggests that the modifications of the strength of pairing correlations required to compensate for their effects are modest. In contrast, time-odd mean fields have profound effect on the properties of odd-proton nuclei in the vicinity of proton-drip line. Their presence can modify the half-lives of proton-emitters (by many orders of magnitude in light nuclei) and affect considerably the possibilities of their experimental observation.
DYNAMIC RESERVOIR CHARACTERIZATION USING P-WAVE SEISMIC TIME-LAPSE AT POSTLE FIELD,
DYNAMIC RESERVOIR CHARACTERIZATION USING P-WAVE SEISMIC TIME-LAPSE AT POSTLE FIELD, TEXAS COUNTY characterize the reservoir at Postle Field. RCP shot a 6.25 square miles 4D, 9C seismic survey in March 2008.3 to 0.15. Quadrature attribute and seismic inversion-of-difference provide qualitative and quantitative
Time-dependent variational approach to molecules in strong laser fields
Gross, E.K.U.
. Owing to their ultra-short duration, femtosecond pulses allow for the direct observation of chemicalTime-dependent variational approach to molecules in strong laser fields Thomas Kreibich a , Robert in strong laser fields using an ansatz for the wavefunction that explicitly incorporates the electron
Quantum Field Theory on Noncommutative Space-Times and the Persistence of Ultraviolet Divergences
M. Chaichian; A. Demichev; P. Presnajder
1999-04-13T23:59:59.000Z
We study properties of a scalar quantum field theory on two-dimensional noncommutative space-times. Contrary to the common belief that noncommutativity of space-time would be a key to remove the ultraviolet divergences, we show that field theories on a noncommutative plane with the most natural Heisenberg-like commutation relations among coordinates or even on a noncommutative quantum plane with $E_q(2)$-symmetry have ultraviolet divergences, while the theory on a noncommutative cylinder is ultraviolet finite. Thus, ultraviolet behaviour of a field theory on noncommutative spaces is sensitive to the topology of the space-time, namely to its compactness. We present general arguments for the case of higher space-time dimensions and as well discuss the symmetry transformations of physical states on noncommutative space-times.
Unitarity bounds and RG flows in time dependent quantum field theory
Xi Dong; Bart Horn; Eva Silverstein; Gonzalo Torroba
2012-03-08T23:59:59.000Z
We generalize unitarity bounds on operator dimensions in conformal field theory to field theories with spacetime dependent couplings. Below the energy scale of spacetime variation of the couplings, their evolution can strongly affect the physics, effectively shifting the infrared operator scaling and unitarity bounds determined from correlation functions in the theory. We analyze this explicitly for large-$N$ double-trace flows, and connect these to UV complete field theories. One motivating class of examples comes from our previous work on FRW holography, where this effect explains the range of flavors allowed in the dual, time dependent, field theory.
Unitarity Bounds and RG Flows in Time Dependent Quantum Field Theory
Dong, Xi; Horn, Bart; Silverstein, Eva; Torroba, Gonzalo; /Stanford U., ITP /Stanford U., Phys. Dept. /SLAC
2012-04-05T23:59:59.000Z
We generalize unitarity bounds on operator dimensions in conformal field theory to field theories with spacetime dependent couplings. Below the energy scale of spacetime variation of the couplings, their evolution can strongly affect the physics, effectively shifting the infrared operator scaling and unitarity bounds determined from correlation functions in the theory. We analyze this explicitly for large-N double-trace flows, and connect these to UV complete field theories. One motivating class of examples comes from our previous work on FRW holography, where this effect explains the range of flavors allowed in the dual, time dependent, field theory.
The development of the time dependence of the nuclear EMP electric field
Eng, C
2009-10-30T23:59:59.000Z
The nuclear electromagnetic pulse (EMP) electric field calculated with the legacy code CHAP is compared with the field given by an integral solution of Maxwell's equations, also known as the Jefimenko equation, to aid our current understanding on the factors that affect the time dependence of the EMP. For a fair comparison the CHAP current density is used as a source in the Jefimenko equation. At first, the comparison is simplified by neglecting the conduction current and replacing the standard atmosphere with a constant density air slab. The simplicity of the resultant current density aids in determining the factors that affect the rise, peak and tail of the EMP electric field versus time. The three dimensional nature of the radiating source, i.e. sources off the line-of-sight, and the time dependence of the derivative of the current density with respect to time are found to play significant roles in shaping the EMP electric field time dependence. These results are found to hold even when the conduction current and the standard atmosphere are properly accounted for. Comparison of the CHAP electric field with the Jefimenko electric field offers a direct validation of the high-frequency/outgoing wave approximation.
Attoclock time and exit momentum in strong-field tunnel ionization
Teeny, Nicolas; Bauke, Heiko; Keitel, Christoph H
2015-01-01T23:59:59.000Z
Tunnel ionization belongs to the fundamental processes of atomic physics. The so-called two-step model, which describes the ionization as instantaneous tunneling at electric field maximum and classical motion afterwards, is commonly employed to describe tunnel ionization in adiabatic regimes. In this contribution, we first show by solving numerically the time-dependent Schr\\"odinger equation in one dimension that there is a time delay between the electric field maximum and the maximum of the ionization rate. This delay is identified as the response time needed by the wavefunction to react to the field maximum. Furthermore, there is a difference between the quantum momentum and the classical momentum from the two-step model after interaction with the driving electric field. Combining both results, we conclude that the electron has an effective initial momentum at the tunneling exit. Our results imply that the two-step model needs modification. The electron's initial momentum has to be incorporated, when tunnel...
Lifshitz field theories, Snyder noncomutative space-time and momentum dependent metric
Romero, Juan M
2015-01-01T23:59:59.000Z
In this work, we propose three different modified relativistic particles. In the first case, we propose a particle with metrics depending on the momenta and we show that the quantum version of these systems includes different field theories, as anisotropic field theories. As a second case we propose a particle that implies a modified symplectic structure and we show that the quantum version of this system gives different noncommutative space-times, for example the Snyder space-time. In the third case, we combine both structures before mentioned, namely noncommutative space-times and momentum dependent metrics. In this last case, we show that anisotropic field theories can be seen as a limit of no commutative field theory.
P-WAVE TIME-LAPSE SEISMIC DATA INTERPRETATION AT RULISON FIELD, PICEANCE BASIN, COLORADO
P-WAVE TIME-LAPSE SEISMIC DATA INTERPRETATION AT RULISON FIELD, PICEANCE BASIN, COLORADO by Donald-lapse seismic surveys, shot by the Reservoir Characterization Project in the fall of 2003 and 2004, at Rulison seismic can monitor tight gas reservoirs, to a limited extent, over a short period of time. Repeat surveys
Photon emission in a constant magnetic field in 2+1 dimensional space-time
J. T. S. Amaral; S. I. Zlatev
2005-11-01T23:59:59.000Z
We calculate by the proper-time method the amplitude of the two-photon emission by a charged fermion in a constant magnetic field in (2+1)-dimensional space-time. The relevant dynamics reduces to that of a supesymmetric quantum-mechanical system with one bosonic and one fermionic degrees of freedom.
SHEAR WAVE TIME-LAPSE SEISMIC MONITORING OF A TIGHT GAS SANDSTONE RESERVOIR, RULISON FIELD, COLORADO
SHEAR WAVE TIME-LAPSE SEISMIC MONITORING OF A TIGHT GAS SANDSTONE RESERVOIR, RULISON FIELD focused specifically on the use of time-lapse (4D) poststack migrated shear-wave seismic data of shear wave data as a tool for monitoring 4D changes. The basin centered tight gas sandstone reservoir
Beyond Additionality in Cap-and-Trade Offset Policy Reuters/Nguyen Huy Kham
the cap. Offsets have assumed an important role in many recent emissions trading programs for greenhouse
Real-Time Magnetic Field Pitch Angle Estimation with a Motional Stark Effect Diagnostic Using Kalman Filtering
A late time accelerated FRW model with scalar and vector fields via Noether symmetry
Babak Vakili
2014-10-22T23:59:59.000Z
We study the evolution of a three-dimensional minisuperspace cosmological model by the Noether symmetry approach. The phase space variables turn out to correspond to the scale factor of a flat Friedmann-Robertson-Walker (FRW) model, a scalar field with potential function $V(\\phi)$ with which the gravity part of the action is minimally coupled and a vector field of its kinetic energy is coupled with the scalar field by a coupling function $f(\\phi)$. Then, the Noether symmetry of such a cosmological model is investigated by utilizing the behavior of the corresponding Lagrangian under the infinitesimal generator of the desired symmetry. We explicitly calculate the form of the coupling function between the scalar and the vector fields and also the scalar field potential function for which such symmetry exists. Finally, by means of the corresponding Noether current, we integrate the equations of motion and obtain exact solutions for the scale factor, scalar and vector fields. It is shown that the resulting cosmology is an accelerated expansion universe for which its expansion is due to the presence of the vector field in the early times, while the scalar field is responsible of its late time expansion.
Localisation of beam offset jitter sources at ATF2
Pfingstner, J; Patecki, M; Schulte, D; Tomás, R
2014-01-01T23:59:59.000Z
For the commissioning and operation of modern particle accelerators, automated error detection and diagnostics methods are becoming increasingly important. In this paper, we present two such methods, which are capable of localising sources of beam offset jitter with a combination of correlation studies and so called degree of freedom plots. The methods were applied to the ATF2 beam line at KEK, where one of the major goals is the reduction of the beam offset jitter. Results of this localisation are shown in this paper. A big advantage of the presented method is its high robustness especially to varying optics parameters. Therefore, we believe that the developed beam offset jitter localisation methods can be easily applied to other accelerators.
Edinburgh, University of
1991-01-01T23:59:59.000Z
rockmass. Such information is important for reservoir characterization and other hydrocarbon production versus offset (AVO) techniques are studied to see if they provide a more viable method of determining. Crampin time delays to build up. In many cases, such as the Austin Chalk in Texas, where the structure
Demers, D. R.; Chen, X.; Schoch, P. M. [Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Fimognari, P. J. [University of Wisconsin, Madison, Wisconsin 53706 (United States)
2010-10-15T23:59:59.000Z
Operation of a heavy ion beam probe (HIBP) on a reversed field pinch is unique from other toroidal applications because the magnetic field is more temporal and largely produced by plasma current. Improved confinement, produced through the transient application of a poloidal electric field which leads to a reduction of dynamo activity, exhibits gradual changes in equilibrium plasma quantities. A consequence of this is sweeping of the HIBP trajectories by the dynamic magnetic field, resulting in motion of the sample volume. In addition, the plasma potential evolves with the magnetic equilibrium. Measurement of the potential as a function of time is thus a combination of temporal changes of the equilibrium and motion of the sample volume. A frequent additional complication is a nonideal balance of ion current on the detectors resulting from changes in the beam trajectory (magnetic field) and energy (plasma potential). This necessitates use of data selection criteria. Nevertheless, the HIBP on the Madison Symmetric Torus has acquired measurements as a function of time throughout improved confinement. A technique developed to infer the potential in the improved confinement reversed field pinch from HIBP data in light of the time varying plasma equilibrium will be discussed.
Quantum field theory in spaces with closed time-like curves
Boulware, D.G.
1992-12-31T23:59:59.000Z
Gott spacetime has closed timelike curves, but no locally anomalous stress-energy. A complete orthonormal set of eigenfunctions of the wave operator is found in the special case of a spacetime in which the total deficit angle is 27{pi}. A scalar quantum field theory is constructed using these eigenfunctions. The resultant interacting quantum field theory is not unitary because the field operators can create real, on-shell, particles in the acausal region. These particles propagate for finite proper time accumulating an arbitrary phase before being annihilated at the same spacetime point as that at which they were created. As a result, the effective potential within the acausal region is complex, and probability is not conserved. The stress tensor of the scalar field is evaluated in the neighborhood of the Cauchy horizon; in the case of a sufficiently small Compton wavelength of the field, the stress tensor is regular and cannot prevent the formation of the Cauchy horizon.
Quantum field theory in spaces with closed time-like curves. [Gott space
Boulware, D.G.
1992-01-01T23:59:59.000Z
Gott spacetime has closed timelike curves, but no locally anomalous stress-energy. A complete orthonormal set of eigenfunctions of the wave operator is found in the special case of a spacetime in which the total deficit angle is 27[pi]. A scalar quantum field theory is constructed using these eigenfunctions. The resultant interacting quantum field theory is not unitary because the field operators can create real, on-shell, particles in the acausal region. These particles propagate for finite proper time accumulating an arbitrary phase before being annihilated at the same spacetime point as that at which they were created. As a result, the effective potential within the acausal region is complex, and probability is not conserved. The stress tensor of the scalar field is evaluated in the neighborhood of the Cauchy horizon; in the case of a sufficiently small Compton wavelength of the field, the stress tensor is regular and cannot prevent the formation of the Cauchy horizon.
Fermion Fields in BTZ Black Hole Space-Time and Entanglement Entropy
Dharm Veer Singh; Sanjay Siwach
2015-08-07T23:59:59.000Z
We study the entanglement entropy of fermion fields in BTZ black hole space-time and calculate pre- factor of the leading and sub-leading terms and logarithmic divergence term of the entropy using the discretized model. The leading term is the standard Bekenstein-Hawking area law and sub-leading term corresponds to first quantum corrections in black hole entropy. We also investigate the corrections to entanglement entropy for massive fermion fields in BTZ space-time. The mass term does not affect the area law.
Imaginary time correlations and the phaseless auxiliary field quantum Monte Carlo
Motta, M.; Galli, D. E.; Vitali, E. [Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy)] [Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, 20133 Milano (Italy); Moroni, S. [IOM-CNR DEMOCRITOS National Simulation Center and SISSA, via Bonomea 265, 34136 Trieste (Italy)] [IOM-CNR DEMOCRITOS National Simulation Center and SISSA, via Bonomea 265, 34136 Trieste (Italy)
2014-01-14T23:59:59.000Z
The phaseless Auxiliary Field Quantum Monte Carlo (AFQMC) method provides a well established approximation scheme for accurate calculations of ground state energies of many-fermions systems. Here we address the possibility of calculating imaginary time correlation functions with the phaseless AFQMC. We give a detailed description of the technique and test the quality of the results for static properties and imaginary time correlation functions against exact values for small systems.
Sergey V. Yakovlev
2011-12-21T23:59:59.000Z
Were investigated anisotropic metric of higher dimensional space-time with only cosmological term and scalar field. Showed, that presence of scalar field is equivalent to anisotropic metric in the multy dimensional space-time and proposed idea of dimensions generation by scalar field. Were solved Einstein's equations for higher dimensional space-time of Kazner's type and derived expressions for density of energy for scalar field, which generate additional dimensions, and proposed the procedure of renormalization of the metric.
A computing strategyfor applicationsinvolving offsets,sweeps,and Minkowski operations
Suresh, Krishnan
.E.Hartquista,J.P.Menonb,K. Sureshc,H.B. Voe1ckera.*,1.Zagajacd "The Sibley School of Mechanical and Aero Engineering, Cornell,Ford Motor Company, Dearborn, MI, USA Received 29 June 1998; accepted 24 September 1998 Abstract Offsets
POTENTIAL MEXICAN OFFSETS TO Business Council for Sustainable Development Mexico
California at Davis, University of
on selected states of Mexico in renewable energy, cogeneration and efficient transportation, with potential, accounting for 26.3 bn exports to Mexico in 2012. · California is a low energy intensive economy (technology initiatives to Produce Carbon Offsets for the California Market (Renewables and Transportation) WIND ENERGY
Jeong, Jaehoon
2009-05-15T23:59:59.000Z
and multiconductor transmission lines. The method is extended to represent the general solution to Maxwell’s differential equations in vector matrix form. It is shown that, given the electromagnetic field and boundary conditions at a given instant in time, the free...
Attoclock time and exit momentum in strong-field tunnel ionization
Nicolas Teeny; Enderalp Yakaboylu; Heiko Bauke; Christoph H. Keitel
2015-02-20T23:59:59.000Z
Tunnel ionization belongs to the fundamental processes of atomic physics. The so-called two-step model, which describes the ionization as instantaneous tunneling at electric field maximum and classical motion afterwards, is commonly employed to describe tunnel ionization in adiabatic regimes. In this contribution, we first show by solving numerically the time-dependent Schr\\"odinger equation in one dimension that there is a time delay between the electric field maximum and the maximum of the ionization rate. This delay is identified as the response time needed by the wavefunction to react to the field maximum. Furthermore, there is a difference between the quantum momentum and the classical momentum from the two-step model after interaction with the driving electric field. Combining both results, we conclude that the electron has an effective initial momentum at the tunneling exit. Our results imply that the two-step model needs modification. The electron's initial momentum has to be incorporated, when tunneling times shall be determined in attoclock experiments.
Results from field tests of the one-dimensional Time-Encoded Imaging System.
Marleau, Peter; Brennan, James S.; Brubaker, Erik
2014-09-01T23:59:59.000Z
A series of field experiments were undertaken to evaluate the performance of the one dimensional time encoded imaging system. The significant detection of a Cf252 fission radiation source was demonstrated at a stand-off of 100 meters. Extrapolations to different quantities of plutonium equivalent at different distances are made. Hardware modifications to the system for follow on work are suggested.
3-D Time-Accurate CFD Simulations of Wind Turbine Rotor Flow Fields
3-D Time-Accurate CFD Simulations of Wind Turbine Rotor Flow Fields Nilay Sezer-Uzol and Lyle N around the National Renewable Energy Laboratory (NREL) Phase VI horizontal axis wind turbine rotor. The 3 turbulent flow that generates the noise, in the context of the wind turbine application. I. Introduction
Near-field Mapping System to Scan in Time Domain the Magnetic Emissions of Integrated Circuits
Paris-Sud XI, Université de
low amplitude and need to be amplified. This is achieved, as shown figure 1, by a low noise 63db of instructions. Application of this measurement system is given to an industrial chip designed with a 180nm CMOS a low cost near-field mapping system. This system scans automatically and dynamically, in the time
Field Test to Demonstrate Real-Time In-Situ Detection of Volatile Organic Compounds
Ho, Cliff
1 Field Test to Demonstrate Real-Time In-Situ Detection of Volatile Organic Compounds Hazmat Spill Center, Nevada Test Site September 19-25, 2001 Clifford K. Ho Sandia National Laboratories Albuquerque-filled 55- gallon drum at the Hazmat Spill Center at the Nevada Test Site. Background and Objectives Tens
Space-Time Models based on Random Fields with Local Interactions
Dionissios T. Hristopulos; Ivi C. Tsantili
2015-03-06T23:59:59.000Z
The analysis of space-time data from complex, real-life phenomena requires the use of flexible and physically motivated covariance functions. In most cases, it is not possible to explicitly solve the equations of motion for the fields or the respective covariance functions. In the statistical literature, covariance functions are often based on mathematical constructions. We propose deriving space-time covariance functions by solving "effective equations of motion", which can be used as statistical representations of systems with diffusive behavior. In particular, we propose using the linear response theory to formulate space-time covariance functions based on an equilibrium effective Hamiltonian. The effective space-time dynamics are then generated by a stochastic perturbation around the equilibrium point of the classical field Hamiltonian leading to an associated Langevin equation. We employ a Hamiltonian which extends the classical Gaussian field theory by including a curvature term and leads to a diffusive Langevin equation. Finally, we derive new forms of space-time covariance functions.
Propagation of Test Particles and Scalar Fields on a Class of Wormhole Space-Times
Peter Taylor
2014-08-18T23:59:59.000Z
In this paper, we consider the problem of test particles and test scalar fields propagating on the background of a class of wormhole space-times. For test particles, we solve for arbitrary causal geodesics in terms of integrals which are solved numerically. These integrals are parametrized by the radius and shape of the wormhole throat as well as the initial conditions of the geodesic trajectory. In terms of these parameters, we compute the conditions for the geodesic to traverse the wormhole, to be reflected by the wormhole's potential or to be captured on an unstable bound orbit at the wormhole's throat. These causal geodesics are visualized by embedding plots in Euclidean space in cylindrical coordinates. For test scalar fields, we compute transmission coefficients and quasi-normal modes for arbitrary coupling of the field to the background geometry in the WKB approximation. We show that there always exists an unstable mode whenever the coupling constant is greater than 1/2. This analysis is interesting since recent computations of self-interactions of a static scalar field in wormhole space-times reveal some anomalous dependence on the coupling constant, principally, the existence of an infinite discrete set of poles. We show that this pathological behavior of the self-field is an artifact of computing the interaction for values of the coupling constant that do not lie in the domain of stability.
Strong Field of Binary Systems And Its Effects On Pulsar Arrival Times
M. I. Wanas; N. S. Awadalla; W. S. El Hanafy
2012-10-05T23:59:59.000Z
In the present work, the exact solution of Einstein's field equations which has been given by Curzon in 1924 representing the field of a static binary system is reviewed. An adapted version of this solution is obtained to describe a dynamical binaries in a rotating coordinate system. It is shown that this version of the solution is time-dependent. It reduces to the later one in the static case if the rotation goes to zero. The original Curzon solution shows that there are two singularities at the two masses, while in the modified version the singularities become on the world-line of the two masses. The solution shows no additional coordinate singularities. The killing vector field of the axial symmetry is obtained in the modified version. In addition, the rotation admits a further rotational symmetry, so a rotation killing vector field is also obtained and discussed. The equations of motion for a test particle in the field of a binary system are formulated and solved. Such equations have been used to study the gravitational time delay of arrival (Shapiro delay) of signals from binary pulsar systems resulted from our suggested modifications containing additional terms. These terms are interpreted as higher order corrections to the masses. In particular we investigate the gravito-magnetic effect due to orbital angular motion of the double pulsars. We give numerical estimates of this type of the time delay in the case of the double-pulsar system PSR J0737-3039 A/B. We draw a model curve for the gravito-magnetic time delay during one orbital revolution. We suggest that this type of delay will have a larger contribution during the last phase of the system evolution.
Zhu, Hong-Ming; Chen, Jin-Wang; Pan, Xiao-Yin, E-mail: panxiaoyin@nbu.edu.cn [Department of Physics, Ningbo University, Ningbo 315211 (China)] [Department of Physics, Ningbo University, Ningbo 315211 (China); Sahni, Viraht [Department of Physics, Brooklyn College and The Graduate School of the City University of New York, New York, New York 10016 (United States)] [Department of Physics, Brooklyn College and The Graduate School of the City University of New York, New York, New York 10016 (United States)
2014-01-14T23:59:59.000Z
We derive via the interaction “representation” the many-body wave function for harmonically confined electrons in the presence of a magnetostatic field and perturbed by a spatially homogeneous time-dependent electric field—the Generalized Kohn Theorem (GKT) wave function. In the absence of the harmonic confinement – the uniform electron gas – the GKT wave function reduces to the Kohn Theorem wave function. Without the magnetostatic field, the GKT wave function is the Harmonic Potential Theorem wave function. We further prove the validity of the connection between the GKT wave function derived and the system in an accelerated frame of reference. Finally, we provide examples of the application of the GKT wave function.
Economic investigation of discount factors for agricultural greenhouse gas emission offsets
Kim, Man-Keun
2005-08-29T23:59:59.000Z
. The permanence discount depends on the project design including practice continuation after the program and the dynamic rate of offset. Also, consideration of multiple offsets is important. Uncertainty arises due to the stochastic nature of project quantity...
Mei Xiaochun
2008-04-19T23:59:59.000Z
Based on Document (1), by considering the retarded interaction of radiation fields, the third order transition probabilities of stimulated radiations and absorptions of light are calculated. The revised formulas of nonlinear polarizations are provided. The results show that that the general processes of non-linear optics violate time reversal symmetry. The phenomena of non-linear optics violating time reversal symmetry just as sum frequency, double frequency, different frequencies, double stable states, self-focusing and self-defocusing, echo phenomena, as well as optical self-transparence and self absorptions and so on are analyzed.
Time-odd triaxial relativistic mean field approach for nuclear magnetic moments
J. M. Yao; H. Chen; J. Meng
2006-06-21T23:59:59.000Z
The time-odd triaxial relativistic mean field approach is developed and applied to the investigation of the ground-state properties of light odd-mass nuclei near the double-closed shells. The nuclear magnetic moments including the isoscalar and isovector ones are calculated and good agreement with Schmidt values is obtained. Taking $^{17}$F as an example, the splitting of the single particle levels (around $~0.7$ MeV near the Fermi level), the nuclear current, the core polarizations, and the nuclear magnetic potential, i.e., the spatial part of the vector potential, due to the violation of the time reversal invariance are investigated in detail.
Landau levels for discrete-time quantum walks in artificial magnetic fields
Pablo Arnault; Fabrice Debbasch
2014-12-14T23:59:59.000Z
A new family of 2D discrete-time quantum walks (DTQWs) is presented and shown to coincide, in the continuous limit, with the Dirac dynamics of a spin 1/2 fermion coupled to a constant and homogeneous magnetic field. Landau levels are constructed, not only in the continuous limit, but also for the DTQWs i.e. for finite non-vanishing values of the time- and position-steps. All results are supported by numerical simulations. The possibility of quantum simulation of condensed matter systems by DTQWs is also discussed.
Controlling NOx to Obtain Offsets or Meet Compliance
Mincy, J. E.
Controlling NOx to Obtain Offsets or Meet Compliance John E. Mincy, Market Development Manager, Nalco Fuel Tech Table I Typical Refinery NOx ProducersINTRODUCTION Even before the Clean Air Act Amendments of 1990, regu latory authorities... monitored and regu lated a number of pollutants: lead, carbon monoxide, oxides of sulfur, oxides of nitrogen, ozone and PM-lO. The Clean Air Act Amendments increased the focus on these pollutants, mandating the reductions to specified limits. Title I...
Hossein Ghaffarnejad
2015-04-29T23:59:59.000Z
Aim of the paper is to obtain 2d analogue of the backreaction equation which will be useful to study final state of quantum perturbed spherically symmetric curved space times. Thus we take Einstein-massless-scalar $\\psi$ tensor gravity model described on class of spherically symmetric curved space times. We rewrite the action functional in 2d analogue in terms of dimensionless dilaton-matter field $(\\chi=\\Phi\\psi)$ where dilaton field $\\Phi$ is conformal factor of 2-sphere. Then we seek renormalized expectation value of quantum dilaton-matter field stress tensor operator by applying Hadamard rennormalization prescription. Singularity of the Green function is assumed to be has logarithmic form. Covariantly conservation condition on the renormalized quantum dilaton-matter stress tensor demands to input a variable cosmological parameter $\\lambda(x)$. Energy conditions (weak, strong and null) is studied on the obtained renormalized stress tensor leading to dynamical equations for $\\lambda(x), \\Phi$ and quantum vacuum state $W_0(x)=_{ren}.$ In weak quantum field limits our obtained trace anomaly corresponds to one which obtained from zeta function regularization method. Setting null-like apparent horizon equation $\
Early Time Dynamics of Gluon Fields in High Energy Nuclear Collisions
G. Chen; R. J. Fries; J. I. Kapusta; Y. Li
2015-07-13T23:59:59.000Z
Nuclei colliding at very high energy create a strong, quasi-classical gluon field during the initial phase of their interaction. We present an analytic calculation of the initial space-time evolution of this field in the limit of very high energies using a formal recursive solution of the Yang-Mills equations. We provide analytic expressions for the initial chromo-electric and chromo-magnetic fields and for their energy-momentum tensor. In particular, we discuss event-averaged results for energy density and energy flow as well as for longitudinal and transverse pressure of this system. For example, we find that the ratio of longitudinal to transverse pressure very early in the system behaves as $p_L/p_T = -[1-\\frac{3}{2a}(Q\\tau)^2]/[1-\\frac{1}{a}(Q\\tau)^2]+\\mathcal{O}(Q\\tau)^4$ where $\\tau$ is the longitudinal proper time, $Q$ is related to the saturation scales $Q_s$ of the two nuclei, and $a = \\ln (Q^2/\\hat{m}^2)$ with $\\hat m$ a scale to be defined later. Our results are generally applicable if $\\tau \\lesssim 1/Q$. As already discussed in a previous paper, the transverse energy flow $S^i$ of the gluon field exhibits hydrodynamic-like contributions that follow transverse gradients of the energy density $\
Kossow, Marcel [I. Institut fuer Theoretische Physik, Universitaet Hamburg, Jungiusstrasse 9, D - 20355 Hamburg (Germany)
2008-03-15T23:59:59.000Z
An energy correction is calculated in the time-independent perturbation setup using a regularized ultraviolet finite Hamiltonian on the noncommutative Minkowski space. The correction to the energy is invariant under rotation and translation but is not Lorentz covariant, and this leads to a distortion of the dispersion relation. In the limit where the noncommutativity vanishes, the common quantum field theory on the commutative Minkowski space is reobtained. The calculations are restricted to the regularized cubic interaction.
TASI Lectures on Holographic Space-Time, SUSY and Gravitational Effective Field Theory
Tom Banks
2010-09-23T23:59:59.000Z
I argue that the conventional field theoretic notion of vacuum state is not valid in quantum gravity. The arguments use gravitational effective field theory, as well as results from string theory, particularly the AdS/CFT correspondence. Different solutions of the same low energy gravitational field equations correspond to different quantum systems, rather than different states in the same system. I then introduce {\\it holographic space-time} a quasi-local quantum mechanical construction based on the holographic principle. I argue that models of quantum gravity in asymptotically flat space-time will be exactly super-Poincare invariant, because the natural variables of holographic space-time for such a system, are the degrees of freedom of massless superparticles. The formalism leads to a non-singular quantum Big Bang cosmology, in which the asymptotic future is required to be a de Sitter space, with cosmological constant (c.c.) determined by cosmological initial conditions. It is also approximately SUSic in the future, with the gravitino mass $K \\Lambda^{1/4}$.
Thermonuclear Supernovae: Probing Magnetic Fields by Late-Time IR Line Profiles
Penney, R
2014-01-01T23:59:59.000Z
We study the imprint of magnetic fields B on late-time IR line profiles and light curves of Type Ia Supernovae. As a benchmark, we use the explosion of a Chandrasekhar mass M_{Ch White Dwarf (WD) and, specifically, a delayed detonation model. We assume WDs with initial magnetic surface fields between 1 and 1E9G. We discuss large-scale dipole and small-scale magnetic fields. We find that the [Fe II] line at 1.644 mu can be used to analyze the overall chemical and density structure of the exploding WD up to day 200 without considering B. Subsequently, positron transport and magnetic field effects become important. By day 500, the profile becomes sensitive to the morphology of B and directional dependent for dipole fields. Small or no directional dependence of the spectra is found for small-scale B. After about 200 days, persistent broad-line, flat-topped or stumpy profiles require high density burning which is the signature of a WD close to M_Ch. Narrow peaked profiles are a signature of chemical mixing or sub-...
Lifetime, turnover time, and fast magnetic field regeneration in random flows
Tanner, S. E. M. [School of Mathematical Sciences, Dublin City University, Dublin 9 (Ireland)
2007-10-15T23:59:59.000Z
The fast dynamo is thought to be relevant in the regeneration of magnetic fields in astrophysics where the value of the magnetic Reynolds number (Rm) is immense. The fast dynamo picture is one in which chaotic flows provide a mechanism for the stretching of magnetic field lines. Furthermore, a cascade of energy down to small scales results in intermittent regions of a small-scale, intense magnetic field. Given this scenario it is natural to invoke the use of kinematic random flows in order to understand field regeneration mechanisms better. Here a family of random flows is used to study the effects that L, the lifetime of the cell, and {tau}, the turnover time of the cell, may have on magnetic field regeneration. Defining the parameter {gamma}=L/{tau}, it has been varied according to {gamma}>1, {gamma}<1, {gamma}{approx}O(1). In the kinematic regime, dynamo growth rates and Lyapunov exponents are examined at varying values of Rm. The possibility of fast dynamo action is considered. In the nonlinear regime, magnetic and kinetic energies are examined. Results indicate that there does appear to be a relationship between {gamma} and dynamo efficiency. In particular, the most efficient dynamos seem to operate at lower values of {gamma}.
First principles investigation of scaling trends of zirconium silicate interface band offsets
Dutton, Robert W.
First principles investigation of scaling trends of zirconium silicate interface band offsets out to investigate the scaling trends of band offsets at model silicon/zirconium silicate interfaces. Owing to the d character of zirconium silicate conduction bands, the band gap and band offset are shown
A Non-Riemannian Metric on Space-Time Emergent From Scalar Quantum Field Theory
Kar, Arnab
2012-01-01T23:59:59.000Z
We show that the standard deviation \\sigma(x,x') = \\sqrt{} of a scalar quantum field theory is a metric (i.e., a symmetric positive function satisfying the triangle inequality) on space-time (with imaginary time). It is very different from the Euclidean metric |x-x'|: for four dimensional free scalar field theory, \\sigma(x,x') \\to \\frac{\\sigma_{4}}{a^{2}} -\\frac{\\sigma_{4}'}{|x-x'|^{2}} + \\mathrm{O}(|x-x'|^{-3}), as |x-x'|\\to\\infty. According to \\sigma, space-time has a finite diameter \\frac{\\sigma_{4}}{a^{2}} which is not universal (i.e., depends on the UV cut-off a and the regularization method used). The Lipschitz equivalence class of the metric is independent of the cut-off. \\sigma(x,x') is not the length of the geodesic in any Riemannian metric, as it does not have the intermediate point property: for a pair (x,x') there is in general no point x" such that \\sigma(x,x')=\\sigma(x,x")+\\sigma(x",x'). Nevertheless, it is possible to embed space-time in a higher dimensional space of negative curvature so that ...
Thermonuclear supernovae: probing magnetic fields by positrons and late-time IR line profiles
Penney, R.; Hoeflich, P., E-mail: phoeflich77@gmail.com, E-mail: rpenney@g.clemson.edu [Department of Physics, Florida State University, Tallahassee, FL 32305 (United States)
2014-11-01T23:59:59.000Z
We show the importance of ? and positron transport for the formation of late-time spectra in Type Ia supernovae (SNe Ia). The goal is to study the imprint of magnetic fields (B) on late-time IR line profiles, particularly the [Fe II] feature at 1.644 ?m, which becomes prominent two to three months after the explosion. As a benchmark, we use the explosion of a Chandrasekhar mass (M {sub Ch}) white dwarf (WD) and, specifically, a delayed detonation model that can reproduce the light curves and spectra for a Branch-normal SN Ia. We assume WDs with initial magnetic surface fields between 1 and 10{sup 9} G. We discuss large-scale dipole and small-scale magnetic fields. We show that positron transport effects must be taken into account for the interpretation of emission features starting at about one to two years after maximum light, depending on the size of B. The [Fe II] line profile and its evolution with time can be understood in terms of the overall energy input by radioactive decay and the transition from a ?-ray to a positron-dominated regime. We find that the [Fe II] line at 1.644 ?m can be used to analyze the overall chemical and density structure of the exploding WD up to day 200 without considering B. At later times, positron transport and magnetic field effects become important. After about day 300, the line profile allows one to probe the size of the B-field. The profile becomes sensitive to the morphology of B at about day 500. In the presence of a large-scale dipole field, a broad line is produced in M {sub Ch} mass explosions that may appear flat-topped or rounded depending on the inclination at which the SN is observed. Small or no directional dependence of the spectra is found for small-scale B. We note that narrow-line profiles require central {sup 56}Ni as shown in our previous studies. Persistent broad-line, flat-topped profiles require high-density burning, which is the signature of a WD close to M {sub Ch}. Good time coverage is required to separate the effects of optical depth, the size and morphology of B, and the aspect angle of the observer. The spectra require a resolution of about 500 km s{sup –1} and a signal-to-noise ratio of about 20%. Two other strong near-IR spectral features at about 1.5 and 1.8 ?m are used to demonstrate the importance of line blending, which may invalidate a kinematic interpretation of emission lines. Flat-topped line profiles between 300 and 400 days have been observed and reported in the literature. They lend support for M {sub Ch} mass explosions in at least some cases and require magnetic fields equal to or in excess of 10{sup 6} G. We briefly discuss the effects of the size and morphology of B on light curves, as well as limitations. We argue that line profiles are a more direct measurement of B than light curves because they measure both the distribution of {sup 56}Ni and the redistribution of the energy input by positrons rather than the total energy input. Finally, we discuss possible mechanisms for the formation of high B-fields and the limitations of our analysis.
Early Time Dynamics of Gluon Fields in High Energy Nuclear Collisions
Chen, G; Kapusta, J I; Li, Y
2015-01-01T23:59:59.000Z
Nuclei colliding at very high energy create a strong, quasi-classical gluon field during the initial phase of their interaction. We present an analytic calculation of the initial space-time evolution of this field in the limit of very high energies using a formal recursive solution of the Yang-Mills equations. We provide analytic expressions for the initial chromo-electric and chromo-magnetic fields and for their energy-momentum tensor. In particular, we discuss event-averaged results for energy density and energy flow as well as for longitudinal and transverse pressure of this system. For example, we find that the ratio of longitudinal to transverse pressure very early in the system behaves as $p_L/p_T = -[1-\\frac{3}{2a}(Q\\tau)^2]/[1-\\frac{1}{a}(Q\\tau)^2]+\\mathcal{O}(Q\\tau)^4$ where $\\tau$ is the longitudinal proper time, $Q$ is related to the saturation scales $Q_s$ of the two nuclei, and $a = \\ln (Q^2/\\hat{m}^2)$ with $\\hat m$ a scale to be defined later. Our results are generally applicable if $\\tau \\less...
The SAMI Galaxy Survey: Unveiling the nature of kinematically offset active galactic nuclei
Allen, J T; Scott, N; Fogarty, L M R; Ho, I -T; Medling, A M; Leslie, S K; Bland-Hawthorn, J; Bryant, J J; Croom, S M; Goodwin, M; Green, A W; Konstantopoulos, I S; Lawrence, J S; Owers, M S; Richards, S N; Sharp, R
2015-01-01T23:59:59.000Z
We have observed two kinematically offset active galactic nuclei (AGN), whose ionised gas is at a different line-of-sight velocity to their host galaxies, with the SAMI integral field spectrograph (IFS). One of the galaxies shows gas kinematics very different to the stellar kinematics, indicating a recent merger or accretion event. We demonstrate that the star formation associated with this event was triggered within the last 100 Myr. The other galaxy shows simple disc rotation in both gas and stellar kinematics, aligned with each other, but in the central region has signatures of an outflow driven by the AGN. Other than the outflow, neither galaxy shows any discontinuity in the ionised gas kinematics at the galaxy's centre. We conclude that in these two cases there is no direct evidence of the AGN being in a supermassive black hole binary system. Our study demonstrates that selecting kinematically offset AGN from single-fibre spectroscopy provides, by definition, samples of kinematically peculiar objects, bu...
Tensor Hierarchy and Generalized Cartan Calculus in SL(3)$\\times$SL(2) Exceptional Field Theory
Hohm, Olaf
2015-01-01T23:59:59.000Z
We construct exceptional field theory for the duality group SL(3)$\\times$SL(2). The theory is defined on a space with 8 `external' coordinates and 6 `internal' coordinates in the $(3,2)$ fundamental representation, leading to a 14-dimensional generalized spacetime. The bosonic theory is uniquely determined by gauge invariance under generalized external and internal diffeomorphisms. The latter invariance can be made manifest by introducing higher form gauge fields and a so-called tensor hierarchy, which we systematically develop to much higher degree than in previous studies. To this end we introduce a novel Cartan-like tensor calculus based on a covariant nil-potent differential, generalizing the exterior derivative of conventional differential geometry. The theory encodes the full $D=11$ or type IIB supergravity, respectively.
Tensor Hierarchy and Generalized Cartan Calculus in SL(3)$\\times$SL(2) Exceptional Field Theory
Olaf Hohm; Yi-Nan Wang
2015-01-30T23:59:59.000Z
We construct exceptional field theory for the duality group SL(3)$\\times$SL(2). The theory is defined on a space with 8 `external' coordinates and 6 `internal' coordinates in the $(3,2)$ fundamental representation, leading to a 14-dimensional generalized spacetime. The bosonic theory is uniquely determined by gauge invariance under generalized external and internal diffeomorphisms. The latter invariance can be made manifest by introducing higher form gauge fields and a so-called tensor hierarchy, which we systematically develop to much higher degree than in previous studies. To this end we introduce a novel Cartan-like tensor calculus based on a covariant nil-potent differential, generalizing the exterior derivative of conventional differential geometry. The theory encodes the full $D=11$ or type IIB supergravity, respectively.
Real-Time Maps of Fluid Flow Fields in Porous Biomaterials
Julia J. Mack; Khalid Youssef; Onika D. V. Noel; Michael Lake; Ashley Wu; M. Luisa Iruela-Arispe; Louis-S. Bouchard
2013-01-13T23:59:59.000Z
Mechanical forces such as fluid shear have been shown to enhance cell growth and differentiation, but knowledge of their mechanistic effect on cells is limited because the local flow patterns and associated metrics are not precisely known. Here we present real-time, noninvasive measures of local hydrodynamics in 3D biomaterials based on nuclear magnetic resonance. Microflow maps were further used to derive pressure, shear and fluid permeability fields. Finally, remodeling of collagen gels in response to precise fluid flow parameters was correlated with structural changes. It is anticipated that accurate flow maps within 3D matrices will be a critical step towards understanding cell behavior in response to controlled flow dynamics.
Real-Time Maps of Fluid Flow Fields in Porous Biomaterials
Mack, Julia J; Noel, Onika D V; Lake, Michael; Wu, Ashley; Iruela-Arispe, M Luisa; Bouchard, Louis-S; 10.1016/j.biomaterials.2012.11.030
2013-01-01T23:59:59.000Z
Mechanical forces such as fluid shear have been shown to enhance cell growth and differentiation, but knowledge of their mechanistic effect on cells is limited because the local flow patterns and associated metrics are not precisely known. Here we present real-time, noninvasive measures of local hydrodynamics in 3D biomaterials based on nuclear magnetic resonance. Microflow maps were further used to derive pressure, shear and fluid permeability fields. Finally, remodeling of collagen gels in response to precise fluid flow parameters was correlated with structural changes. It is anticipated that accurate flow maps within 3D matrices will be a critical step towards understanding cell behavior in response to controlled flow dynamics.
Time-Resolved Imaging and Manipulation of H{sub 2} Fragmentation in Intense Laser Fields
Ergler, Th.; Rudenko, A.; Feuerstein, B.; Zrost, K.; Schroeter, C.D.; Moshammer, R.; Ullrich, J. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany)
2005-08-26T23:59:59.000Z
We report on the experimental realization of time-resolved coincident Coulomb explosion imaging of H{sub 2} fragmentation in 10{sup 14} W/cm{sup 2} laser fields. Combining a high-resolution 'reaction microscope' and a fs pump-probe setup, we map the motion of wave packets dissociating via one- or two-photon channels, respectively, and observe a new region of enhanced ionization. The long-term interferometric stability of our system allows us to extend pump-probe experiments into the region of overlapping pulses, which offers new possibilities for the manipulation of ultrafast molecular fragmentation dynamics.
Borgogno, D. [Dipartimento di Energetica, Politecnico di Torino, Torino (Italy); Grasso, D. [Dipartimento di Energetica, Politecnico di Torino, Torino (Italy); CNR Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, Dipartimento di Energetica, Politecnico di Torino, Torino (Italy); Pegoraro, F. [Physics Department, Pisa University, Pisa, CNISM (Italy); Schep, T. J. [Physics Department, Eindhoven University of Technology, Eindhoven (Netherlands)
2011-10-15T23:59:59.000Z
The transitional phase from local to global chaos in the magnetic field of a reconnecting current layer is investigated. Regions where the magnetic field is stochastic exist next to regions where the field is more regular. In regions between stochastic layers and between a stochastic layer and an island structure, the field of the finite time Lyapunov exponent (FTLE) shows a structure with ridges. These ridges, which are special gradient lines that are transverse to the direction of minimum curvature of this field, are approximate Lagrangian coherent structures (LCS) that act as barriers for the transport of field lines.
Tretiak, Sergei [Los Alamos National Laboratory
2008-01-01T23:59:59.000Z
Four different numerical algorithms suitable for a linear scaling implementation of time-dependent Hartree-Fock and Kohn-Sham self-consistent field theories are examined. We compare the performance of modified Lanczos, Arooldi, Davidson, and Rayleigh quotient iterative procedures to solve the random-phase approximation (RPA) (non-Hermitian) and Tamm-Dancoff approximation (TDA) (Hermitian) eigenvalue equations in the molecular orbital-free framework. Semiempirical Hamiltonian models are used to numerically benchmark algorithms for the computation of excited states of realistic molecular systems (conjugated polymers and carbon nanotubes). Convergence behavior and stability are tested with respect to a numerical noise imposed to simulate linear scaling conditions. The results single out the most suitable procedures for linear scaling large-scale time-dependent perturbation theory calculations of electronic excitations.
Reconstructing the Profile of Time-Varying Magnetic Fields With Quantum Sensors
Easwar Magesan; Alexandre Cooper; Honam Yum; Paola Cappellaro
2013-05-28T23:59:59.000Z
Quantum systems have shown great promise for precision metrology thanks to advances in their control. This has allowed not only the sensitive estimation of external parameters but also the reconstruction of their temporal profile. In particular, quantum control techniques and orthogonal function theory have been applied to the reconstruction of the complete profiles of time-varying magnetic fields. Here, we provide a detailed theoretical analysis of the reconstruction method based on the Walsh functions, highlighting the relationship between the orthonormal Walsh basis, sensitivity of field reconstructions, data compression techniques, and dynamical decoupling theory. Specifically, we show how properties of the Walsh basis and a detailed sensitivity analysis of the reconstruction protocol provide a method to characterize the error between the reconstructed and true fields. In addition, we prove various results about the negligibility function on binary sequences which lead to data compression techniques in the Walsh basis and a more resource-efficient reconstruction protocol. The negligibility proves a fruitful concept to unify the information content of Walsh functions and their dynamical decoupling power, which makes the reconstruction method robust against noise.
Semiclassical Strings in Electric and Magnetic Fields Deformed $AdS_5 \\times S^5$ Spacetimes
Wung-Hong Huang
2006-01-06T23:59:59.000Z
We first apply the transformation of mixing azimuthal and internal coordinate or mixing time and internal coordinate to the 11D M-theory with a stack N M2-branes to find the spacetime of a stack of N D2-branes with magnetic or electric flux in 10 D IIA string theory, after the Kaluza-Klein reduction. We then perform the T duality to the spacetime to find the background of a stack of N D3-branes with magnetic or electric flux. In the near-horizon limit the background becomes the magnetic or electric field deformed $AdS_5 \\times S^5$. We adopt an ansatz to find the classical string solution which is rotating in the deformed $S^5$ with three angular momenta in the three rotation planes. The relations between the classical string energy and its angular momenta are found and results show that the external magnetic and electric fluxes will increase the string energy. Therefore, from the AdS/CFT point of view, the corrections of the anomalous dimensions of operators in the dual SYM theory will be positive. We also investigate the small fluctuations in these solutions and discuss the effects of magnetic and electric fields on the stability of these classical rotating string solutions. Finally, we find the possible solutions of string pulsating on the deformed spacetimes and show that the corrections to the anomalous dimensions of operators in the dual SYM theory are non-negative.
Transmission line relay mis-operation detection based on time-synchronized field data
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Esmaeilian, Ahad; Popovic, Tomo; Kezunovic, Mladen
2015-08-01T23:59:59.000Z
In this paper, a real-time tool to detect transmission line relay mis-operation is implemented. The tool uses time-synchronized measurements obtained from both ends of the line during disturbances. The proposed fault analysis tool comes into the picture only after the protective device has operated and tripped the line. The proposed methodology is able not only to detect, classify, and locate transmission line faults, but also to accurately confirm whether the line was tripped due to a mis-operation of protective relays. The analysis report includes either detailed description of the fault type and location or detection of relay mis-operation. As such,more »it can be a source of very useful information to support the system restoration. The focus of the paper is on the implementation requirements that allow practical application of the methodology, which is illustrated using the field data obtained the real power system. Testing and validation is done using the field data recorded by digital fault recorders and protective relays. The test data included several hundreds of event records corresponding to both relay mis-operations and actual faults. The discussion of results addresses various challenges encountered during the implementation and validation of the presented methodology.« less
Change in Hamiltonian General Relativity from the Lack of a Time-like Killing Vector Field
J. Brian Pitts
2014-06-07T23:59:59.000Z
In General Relativity in Hamiltonian form, change has seemed to be missing, defined only asymptotically, or otherwise obscured at best, because the Hamiltonian is a sum of first-class constraints and a boundary term and thus supposedly generates gauge transformations. Attention to the gauge generator G of Rosenfeld, Anderson, Bergmann, Castellani et al., a specially tuned sum of first-class constraints, facilitates seeing that a solitary first-class constraint in fact generates not a gauge transformation, but a bad physical change in electromagnetism (changing E) or GR. The change spoils the Lagrangian constraints in terms of the physically relevant velocities rather than auxiliary canonical momenta. While Maudlin has defended change in GR much as G. E. Moore resisted skepticism, there remains a need to exhibit the technical flaws in the argument. Insistence on Hamiltonian-Lagrangian equivalence, a theme emphasized by Mukunda, Castellani, Sugano, Pons, Salisbury, Shepley and Sundermeyer among others, holds the key. Taking objective change to be ineliminable time dependence, there is change in vacuum GR just in case there is no time-like vector field satisfying Killing's equation. Throwing away the spatial dependence of GR for convenience, one finds that the time evolution from Hamilton's equations is real change just when there is no time-like Killing vector. Hence change is real and local even in the Hamiltonian formalism. The considerations here resolve the Earman-Maudlin standoff: the Hamiltonian formalism is helpful, and, suitably reformed, it does not have absurd consequences for change. Hence the classical problem of time is resolved, apart from the issue of observables, for which the solution is outlined. The quantum problem of time, however, is not automatically resolved due to issues of quantum constraint imposition.
THE ROCKSTAR PHASE-SPACE TEMPORAL HALO FINDER AND THE VELOCITY OFFSETS OF CLUSTER CORES
Behroozi, Peter S.; Wechsler, Risa H.; Wu, Hao-Yi [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics, Stanford University, Stanford, CA 94305 (United States)] [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics, Stanford University, Stanford, CA 94305 (United States)
2013-01-10T23:59:59.000Z
We present a new algorithm for identifying dark matter halos, substructure, and tidal features. The approach is based on adaptive hierarchical refinement of friends-of-friends groups in six phase-space dimensions and one time dimension, which allows for robust (grid-independent, shape-independent, and noise-resilient) tracking of substructure; as such, it is named ROCKSTAR (Robust Overdensity Calculation using K-Space Topologically Adaptive Refinement). Our method is massively parallel (up to 10{sup 5} CPUs) and runs on the largest current simulations (>10{sup 10} particles) with high efficiency (10 CPU hours and 60 gigabytes of memory required per billion particles analyzed). A previous paper has shown ROCKSTAR to have excellent recovery of halo properties; we expand on these comparisons with more tests and higher-resolution simulations. We show a significant improvement in substructure recovery compared to several other halo finders and discuss the theoretical and practical limits of simulations in this regard. Finally, we present results that demonstrate conclusively that dark matter halo cores are not at rest relative to the halo bulk or substructure average velocities and have coherent velocity offsets across a wide range of halo masses and redshifts. For massive clusters, these offsets can be up to 350 km s{sup -1} at z = 0 and even higher at high redshifts. Our implementation is publicly available at http://code.google.com/p/rockstar.
Fast evaluation of far-field signals for time-domain wave propagation
Scott E. Field; Stephen R. Lau
2014-09-20T23:59:59.000Z
Time-domain simulation of wave phenomena on a finite computational domain often requires a fictitious outer boundary. An important practical issue is the specification of appropriate boundary conditions on this boundary, often conditions of complete transparency. Attention to this issue has been paid elsewhere, and here we consider a different, although related, issue: far-field signal recovery. Namely, from smooth data recorded on the outer boundary we wish to recover the far-field signal which would reach arbitrarily large distances. These signals encode information about interior scatterers and often correspond to actual measurements. This article expresses far-field signal recovery in terms of time-domain convolutions, each between a solution multipole moment recorded at the boundary and a sum-of-exponentials kernel. Each exponential corresponds to a pole term in the Laplace transform of the kernel, a finite sum of simple poles. Greengard, Hagstrom, and Jiang have derived the large-$\\ell$ (spherical-harmonic index) asymptotic expansion for the pole residues, and their analysis shows that, when expressed in terms of the exact sum-of-exponentials, large-$\\ell$ signal recovery is plagued by cancellation errors. Nevertheless, through an alternative integral representation of the kernel and its subsequent approximation by a {\\em smaller} number of exponential terms (kernel compression), we are able to alleviate these errors and achieve accurate signal recovery. We empirically examine scaling relations between the parameters which determine a compressed kernel, and perform numerical tests of signal "teleportation" from one radial value $r_1$ to another $r_2$, including the case $r_2=\\infty$. We conclude with a brief discussion on application to other hyperbolic equations posed on non-flat geometries where waves undergo backscatter.
Environmental Measurement While Drilling System for Real-Time Field Screening of Contaminants
Lockwood, G.J.; Normann, R.A.; Williams, C.V.
1999-02-22T23:59:59.000Z
Sampling during environmental drilling is essential to fully characterize the spatial distribution and migration of subsurface contaminants. However, analysis of the samples is expensive and time-consuming: off-site laboratory analysis can take weeks or months. Real-time information on environmental conditions, drill bit location and temperature during drilling is valuable in many environmental restoration operations. This type of information can be used to provide field screening data and improved efficiency of site characterization activities. The Environmental Measurement-While-Drilling (EMWD) System represents an innovative blending of new and existing technology in order to obtain real-time data during drilling. The system consists of two subsystems. The down-hole subsystem (at the drill bit) consists of sensors, a power supply, a signal conditioning and transmitter board, and a radio-frequency (RF) coaxial cable. The up-hole subsystem consists of a battery pack/coil, pickup coil, receiver, and personal computer. The system is compatible with fluid miser drill pipe, a directional drilling technique that uses minimal drilling fluids and generates little to no secondary waste. In EMWD, downhole sensors are located behind the drill bit and linked by a high-speed data transmission system to a computer at the surface. Sandia-developed Windows{trademark}-based software is used for data display and storage. As drilling is conducted, data is collected on the nature and extent of contamination, enabling on-the-spot decisions regarding drilling and sampling strategies. Initially, the downhole sensor consisted of a simple gamma radiation detector, a Geiger-Mueller tube (GMT). The design includes data assurance techniques to increase safety by reducing the probability of giving a safe indication when an unsafe condition exists. The EMWD system has been improved by the integration of a Gamma Ray Spectrometer (GRS) in place of the GMT. The GRS consists of a sodium iodide-thallium activated crystal coupled to a photomultiplier tube (PMT). The output of the PMT goes to a multichannel analyzer (MCA).The MCA data is transmitted to the surface via a signal conditioning and transmitter board similar to that used with the GMT. The EMWD system is described and the results of the GRS field tests and field demonstration are presented.
Time-reversal symmetry breaking and the field theory of quantum chaos
Simons, B.D. [Cavendish Laboratory, Madingley Road, Cambridge, CB3 0HE (United Kingdom)] [Cavendish Laboratory, Madingley Road, Cambridge, CB3 0HE (United Kingdom); Agam, O. [NEC Research Institute, 4 Independence Way, Princeton, New Jersey 08540 (United States)] [NEC Research Institute, 4 Independence Way, Princeton, New Jersey 08540 (United States); Andreev, A.V. [Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)] [Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)
1997-04-01T23:59:59.000Z
Recent studies have shown that the quantum statistical properties of systems which are chaotic in their classical limit can be expressed in terms of an effective field theory. Within this description, spectral properties are determined by low energy relaxation modes of the classical evolution operator. It is in the interaction of these modes that quantum interference effects are encoded. In this paper we review this general approach and discuss how the theory is modified to account for time-reversal symmetry breaking. To keep our discussion general, we will also briefly describe how the theory is modified by the presence of an additional discrete symmetry such as inversion. Throughout, parallels are drawn between quantum chaotic systems and the properties of weakly disordered conductors. {copyright} {ital 1997 American Institute of Physics.}
Krivobokova, Tatyana
Do Shocks of Civil War Alter Social, Risk and Time Preferences? Results from Field Experiments us to investigate the relationship between civil war shocks on preferences, whilst controlling to their neighbours, are more risk seeking and have higher discount rates. Keywords: civil war, preferences, field
Band offsets at heterojunctions and the charge neutrality condition
Taferner, Waltraud Teresa
1990-01-01T23:59:59.000Z
P InSb ZnSe Znte Gap indirect indirect indirect indirect direct indirect direct direct direct direct direct direct E4 (eV) O'K 0. 76 1. 13 2. 30 1. 88 1. 55 2. 35 0. 78 0. 43 1. 41 0. 23 2. 68 2. 56 If the atoms of a...&' ?r&rl c!?? &'nt h&: R . F. . X I 1 e n t C. 'k&r&ic &?f l'nn&rr&it&ee) l. H. B. r&ss (:& I e m h e r! R. R. L?cchese (lvlpmhe& ) etta. g R. AIT&&J?' &t t (Ifead of Department) May 1990 ABSTRACT Band OfFsets at Heterojunctions...
The time evolution of turbulent parameters in reversed-field pinch plasmas
Titus, J. B.; Alexander, Brandon [Florida A and M University, Tallahassee, Florida 32310 (United States); Johnson, J. A. III [Pyramid Plasmas LLC, Lawrenceville, Georgia 30043 (United States)
2013-04-28T23:59:59.000Z
Turbulence is abundant in fully ionized fusion plasmas, with unique turbulent characteristics in different phases of the discharge. Using Fourier and chaos-based techniques, a set of parameters have been developed to profile the time evolution of turbulence in high temperature, fusion plasmas, specifically in self-organized, reversed-field pinch plasma in the Madison Symmetric Torus. With constant density and plasma current, the turbulence profile is measured during ramp-up, magnetic reconnection, and increased confinement phases. During magnetic reconnection, a scan of plasma current is performed with a constant density. Analysis revealed that the energy associated with turbulence (turbulent energy) is found to increase when changes in magnetic energy occur and is correlated to edge ion temperatures. As the turbulent energy increases with increasing current, the rate at which this energy flow between scales (spectral index) and anti-persistence of the fluctuations increases (Hurst exponent). These turbulent parameters are then compared to the ramp-up phase and increased confinement regime.
Economic Trade-Offs between Carbon Offset and Timber Opportunities in British Columbia's Central on the implications of timber harvest and carbon offset projects in British Columbia. I would also like to thank Research Project Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Resource
An enhanced model for calculating delay as a function of offset
Jain, Shweta
1996-01-01T23:59:59.000Z
This thesis presents the enhancements made to an existing model for calculating delay as a function of offset between the traffic signals of a link. The delay-difference-of offset technique is a signal control concept used for strategic optimization...
Blade Offset and Pitch Effects on a High Solidity Vertical Axis Wind Turbine
Tullis, Stephen
Blade Offset and Pitch Effects on a High Solidity Vertical Axis Wind Turbine Andrzej J. Fiedler ABSTRACT A high solidity, small scale, 2.5m diameter by 3m high Vertical Axis Wind Turbine (VAWT turbines. Keywords: Vertical Axis Wind Turbine, VAWT, airfoil, pitch, blade, mount, offset, high solidity
An enhanced model for calculating delay as a function of offset
Jain, Shweta
1996-01-01T23:59:59.000Z
This thesis presents the enhancements made to an existing model for calculating delay as a function of offset between the traffic signals of a link. The delay-difference-of offset technique is a signal control concept used for strategic optimization...
Effect of the electric field on the creation of fermions in de-Sitter space-time
Haouat, S
2015-01-01T23:59:59.000Z
The effect of the electric field on the creation of spin 1/2 particles from vacuum in the (1+1) dimensional de-Sitter space-time is studied. The Dirac equation with a constant electric field is solved by introducing an unitary transformation. Then the canonical method based on Bogoliubov transformation is applied to calculate the pair creation probability and the density of created particles both for positive or negative wave vector. By doing summation over all allowed states, the number of created particles per unit of time per unit of length and the imaginary part of the Schwinger effective action are expressed in closed forms. It is shown that the electric field leads to a significant enhancement of the particle creation. The weak expansion case and the limit H=0, where dS space reduces to the flat Minkowski space-time, are discussed.
Sujan Sengupta
1998-01-29T23:59:59.000Z
The ohmic decay of magnetic fields confined within the crust of neutron stars is considered by incorporating both the effect of neutron star cooling and the effect of space-time curvature produced by the intense gravitational field of the star. For this purpose a stationary and static gravitational field has been considered with the standard as well as the accelerated cooling models of neutron stars. It is shown that general relativistic effect reduces the magnetic field decay rate substantially. At the late stage of evolution when the field decay is mainly determined by the impurity-electron scattering, the effect of space-time curvature suppresses the role of the impurity content significantly and reduces the decay rate by more than an order of magnitude. Even with a high impurity content the decay rate is too low to be of observational interest if the accelerated cooling model along with the effect of space-time curvature is taken into account. It is, therefore, pointed out that if a decrease in the magnetic field strength by more than two orders of magnitude from its initial value is detected by observation then the existence of quark in the core of the neutron star would possibly be ruled out.
Lee, KyeoReh; Park, Jung-Hoon; Park, Ji-Ho; Park, YongKeun
2015-01-01T23:59:59.000Z
Rewinding the arrow of time via phase conjugation is an intriguing phenomena made possible by the wave property of light. To exploit this phenomenon, many diverse research fields have pursed the realization of an ideal phase conjugation mirror, but the ideal phase conjugation mirror - an optical system that requires a single-input and a single-output beam, like natural conventional mirrors - has never been demonstrated. Here, we demonstrate the realization of a one-wave optical time-reversal mirror using a spatial light modulator and a single-mode reflector. Our method is simple, alignment free, and fast while allowing unlimited power throughput in the time reversed wave, which have not been simultaneously demonstrated before. Using our method, we demonstrate high throughput time-reversal full-field light delivery through highly scattering biological tissue and multimode fibers, even for quantum dot fluorescence.
Linear Boltzmann equation as the long time dynamics of an electron weakly coupled to a phonon field
Laszlo Erdos
2001-08-29T23:59:59.000Z
We consider the long time evolution of a quantum particle weakly interacting with a phonon field. We show that in the weak coupling limit the Wigner distribution of the electron density matrix converges to the solution of the linear Boltzmann equation globally in time. The collision kernel is identified as the sum of an emission and an absorption term that depend on the equilibrium distribution of the free phonon modes.
Kim, Jieun, S.M. Massachusetts Institute of Technology
2010-01-01T23:59:59.000Z
Carbon offset is one type of flexibility mechanism in greenhouse gas emission trading schemes that helps nations meet their emission commitments at lower costs. Carbon offsets take advantage of lower abatement cost ...
ZnO/Sn:In2O3 and ZnO/CdTe band offsets for extremely thin absorber...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
ZnOSn:In2O3 and ZnOCdTe band offsets for extremely thin absorber photovoltaics . ZnOSn:In2O3 and ZnOCdTe band offsets for extremely thin absorber photovoltaics . Abstract: Band...
A Parallel Coiled-Coil Tetramer with Offset Helices
Liu,J.; Deng, Y.; Zheng, Q.; Cheng, C.; Kallenbach, N.; Lu, M.
2006-01-01T23:59:59.000Z
Specific helix-helix interactions are fundamental in assembling the native state of proteins and in protein-protein interfaces. Coiled coils afford a unique model system for elucidating principles of molecular recognition between {alpha} helices. The coiled-coil fold is specified by a characteristic seven amino acid repeat containing hydrophobic residues at the first (a) and fourth (d) positions. Nonpolar side chains spaced three and four residues apart are referred to as the 3-4 hydrophobic repeat. The presence of apolar amino acids at the e or g positions (corresponding to a 3-3-1 hydrophobic repeat) can provide new possibilities for close-packing of {alpha}-helices that includes examples such as the lac repressor tetramerization domain. Here we demonstrate that an unprecedented coiled-coil interface results from replacement of three charged residues at the e positions in the dimeric GCN4 leucine zipper by nonpolar valine side chains. Equilibrium circular dichroism and analytical ultracentrifugation studies indicate that the valine-containing mutant forms a discrete {alpha}-helical tetramer with a significantly higher stability than the parent leucine-zipper molecule. The 1.35 {angstrom} resolution crystal structure of the tetramer reveals a parallel four-stranded coiled coil with a three-residue interhelical offset. The local packing geometry of the three hydrophobic positions in the tetramer conformation is completely different from that seen in classical tetrameric structures yet bears resemblance to that in three-stranded coiled coils. These studies demonstrate that distinct van der Waals interactions beyond the a and d side chains can generate a diverse set of helix-helix interfaces and three-dimensional supercoil structures.
Initial Simulation Results of Storm-Time Ring Current in a Self-Consistent Magnetic Field Model
Lyons, Larry
, and electrons. The ring current is greatly intensified during geomagnetic storms, and produces large measurement of the magnetic disturbances from all magnetospheric currents on the surface of the EarthInitial Simulation Results of Storm-Time Ring Current in a Self-Consistent Magnetic Field Model S
A charged particle in a homogeneous magnetic field accelerated by a time periodic Aharonov-Bohm flux
T. Kalvoda; P. Stovicek
2011-07-14T23:59:59.000Z
We consider a nonrelativistic quantum charged particle moving on a plane under the influence of a uniform magnetic field and driven by a periodically time-dependent Aharonov-Bohm flux. We observe an acceleration effect in the case when the Aharonov-Bohm flux depends on time as a sinusoidal function whose frequency is in resonance with the cyclotron frequency. In particular, the energy of the particle increases linearly for large times. An explicit formula for the acceleration rate is derived with the aid of the quantum averaging method, and then it is checked against a numerical solution with a very good agreement.
Carbon Offsets as a Cost Containment Instrument: A Case Study of Reducing Emissions from and Policy Program #12;2 #12;3 Carbon Offsets as a Cost Containment Instrument: A Case Study of Reducing in Technology and Policy Abstract Carbon offset is one type of flexibility mechanism in greenhouse gas emission
Neogene tectonics of northern Central America prior to offset across the polochic fault
Burkart, B.; Sanchez-Barreda, L.A.; Deaton, B.C.
1985-01-01T23:59:59.000Z
The reconstruction which removes 130 km of documented left slip across the Polochic fault of northern Guatemala and southern Chiapas juxtaposes the foundered block of the Gulf of Tehuantepec and extensional terrane of Guatemala, lining up prolongations of the Motagua and Jocotan faults with known structures along the coastal margin of the Chiapas massif and within the Gulf. Coast-parallel faults with sinistral displacement, located along the margins of the Chiapas depression, were also active during the Miocene time interval of south-easterly migration of the Gulf of Tehuantepec block. Extensional terrane is well expressed in Guatemala and Honduras south of the Jocotan boundary fault, beginning where the southeasterly-moving block encounters the abrupt bend in the boundary fault. This complex plate boundary became simpler when the left-lateral, east-west-trending Polochic fault sliced across the isthmus in late Miocene, offsetting Laramide structures and the arcuate Neogene plate boundary faults. During its time of major activity the Polochic served as the principal plate boundary fault, across which the major displacement occurred. Today the western part of the NOAM-CARIB plate boundary is diffuse. From western Guatemala and southern Chiapas, where buckling and locking of the Polochic fault has taken place, displacement is distributed among countless shears which extend in a belt from western Guatemala across the Chiapas massif to the western landframe of the Gulf of Tehuantepec.
EECBG Success Story: Small Town Using Wind Power to Offset Electricity...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Wind Power to Offset Electricity Costs September 8, 2010 - 10:26am Addthis Carmen, Oklahoma, is not your average small town. It was the first recipient of an Energy Efficiency...
Economic investigation of discount factors for agricultural greenhouse gas emission offsets
Kim, Man-Keun
2005-08-29T23:59:59.000Z
This dissertation analyzes the basis for and magnitudes of discount factors based on the characteristics of greenhouse gas emission (GHGE) offsets that are applied to the GHGE reduction projects, concentrating on agricultural projects. Theoretical...
Fermion production by a dependent of time electric field in de Sitter universe
Cosmin Crucean
2013-07-03T23:59:59.000Z
Fermion production by the electric field of a charge on de Sitter expanding universe is analyzed. The amplitude and probability of pair production are computed. We obtain from our calculations that the modulus of the momentum is no longer conserved and that there are probabilities for production processes where the helicity is no longer conserved. The rate of pair production in an electric field is found to be important in the early universe when the expansion factor was large comparatively with the particle mass.
TIME-LAPSE VP/VS ANALYSIS FOR RESERVOIR CHARACTERIZATION, RULISON FIELD, COLORADO
from post-stack inversion of P- and S- wave datasets from three (3) time-lapse dedicated 9C surveys-component seismic is used to help with reservoir characterization of tight gas sands via time-lapse VP/VS volumes11 and slow-shear S22) I performed post-stack inversion of the corresponding datasets to obtain
Commensurate Two-Quantum Coherences Induced by Time-Delayed THz Fields
Fleischer, Sharly
The interaction of carbonyl sulfide dipolar gas molecules with two time-delayed, single-cycle THz pulses is shown both experimentally and theoretically to induce two-quantum rotational coherences that are significantly ...
Helium in chirped laser fields as a time-asymmetric atomic switch
Kaprálová-Ž?ánská, Petra Ruth, E-mail: kapralova@jh-inst.cas.cz [Department of Radiation and Chemical Physics, Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8 (Czech Republic); J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, 182 23 Prague 8 (Czech Republic); Moiseyev, Nimrod, E-mail: nimrod@tx.technion.ac.il [Schulich Faculty of Chemistry and Faculty of Physics, Technion – Israel Institute of Technology, Haifa 32000 (Israel)
2014-07-07T23:59:59.000Z
Tuning the laser parameters exceptional points in the spectrum of the dressed laser helium atom are obtained. The weak linearly polarized laser couples the ground state and the doubly excited P-states of helium. We show here that for specific chirped laser pulses that encircle an exceptional point one can get the time-asymmetric phenomenon, where for a negative chirped laser pulse the ground state is transformed into the doubly excited auto-ionization state, while for a positive chirped laser pulse the resonance state is not populated and the neutral helium atoms remains in the ground state as the laser pulse is turned off. Moreover, we show that the results are very sensitive to the closed contour we choose. This time-asymmetric state exchange phenomenon can be considered as a time-asymmetric atomic switch. The optimal time-asymmetric switch is obtained when the closed loop that encircles the exceptional point is large, while for the smallest loops, the time-asymmetric phenomenon does not take place. A systematic way for studying the effect of the chosen closed contour that encircles the exceptional point on the time-asymmetric phenomenon is proposed.
Green, Mike; Green, M.A.; Strauss, B.P.
2007-08-27T23:59:59.000Z
By various theorems one can relate the capital cost of superconducting magnets to the magnetic energy stored within that magnet. This is particularly true for magnet where the cost is dominated by the structure needed to carry the magnetic forces. One can also relate the cost of the magnet to the product of the magnetic induction and the field volume. The relationship used to estimate the cost the magnet is a function of the type of magnet it is. This paper updates the cost functions given in two papers that were published in the early 1990 s. The costs (escalated to 2007 dollars) of large numbers of LTS magnets are plotted against stored energy and magnetic field time field volume. Escalated costs for magnets built since the early 1990 s are added to the plots.
Tanimura, Yusuke; Scamps, Guillaume
2015-01-01T23:59:59.000Z
Given a set of collective variables, a method is proposed to obtain the associated conjugated collective momenta and masses starting from a microscopic time-dependent mean-field theory. The construction of pairs of conjugated variables is the first step to bridge microscopic and macroscopic approaches. The method is versatile and can be applied to study a large class of nuclear processes. An illustration is given here with the fission of $^{258}$Fm. Using the quadrupole moment and eventually higher-order multipole moments, the associated collective masses are estimated along the microscopic mean-field evolution. When more than one collective variable are considered, it is shown that the off-diagonal matrix elements of the inertia play a crucial role. Using the information on the quadrupole moment and associated momentum, the collective evolution is studied. It is shown that dynamical effects beyond the adiabatic limit are important. Nuclei formed after fission tend to stick together for longer time leading to...
Field Instruments for Real Time In-Situ Crude Oil Concentration Measurements
Fuller, C. B.; Bonner, J. S.; Page, C. A.; Arrambide, G.; Sterling Jr., M. C.; Ojo, T.
&M University - Corpus Christi Near-shore Environments ? Major changes in near-shore ecosystems occur as pulses during stochastic events ? Sampling frequency must be greater than inherent frequency of the system ? Punctual sampling generally will miss... Instrumentation ECO-FL3 by WET Labs 10-AU Field Fluorometer by Turner Designs FlashLamp by WET Labs Photos from manufacturers? websites Methods/Materials (Reactor Set-up) ? The Reactor Set-up ? derivative of standard jar test apparatus ? agitated using a...
Offset, tilted dipole models of Uranian smooth high-frequency radio emission
Schweitzer, A.E.; Romig, J.H.; Evans, D.R.; Sawyer, C.B. (Radiophysics, Inc., Boulder, CO (USA)); Warwick, J.W. (Radiophysics, Inc., Boulder, CO (USA) Univ. of Colorado, Boulder (USA))
1990-09-01T23:59:59.000Z
During the Voyager 2 encounter with Uranus in January 1986, the Planetary Radio Astronomy (PRA) experiment detected a complex pattern of radio emissions. Two types of emissions were seen: smooth and bursty. The smooth emission has been divided into smooth high-frequency (SHF) and smooth low-frequency (SLF) components which are presumed to come from different sources because of their distinctly different characteristics. The SHF component is considered in this paper. The SHF emission has been modeled by many authors on OTD (offset, tilted dipole (Ness et al., 1986)) L shells ranging from 5 to 40. However, the bursts have been modeled at much higher L shells. The authors complete an OTD investigation of the SHF emission at high L shells within the range of the bursty source locations, and present a viable high L shell model. This model has fundamentally the same longitudinally symmetric net emission pattern in space as the L shell 5 model presented in Romig et al. (1987) and Barbosa (1988). However, they were unable to produce an acceptable model on intermediate L shells without restricting source longitude. They discuss the similarities and distinctions between their two models and the models of other authors. They believe that the high L shell model (and others similar to it) cannot account for the observed smoothness and periodicity of the SHF emissions because it has open field lines containing untrapped particles, which should produce more variable emission than that seen in the SHF data. Therefore, the authors prefer models at L shells less than 18, the boundary for closed field lines (Ness et al., 1986). They then discuss and contrast two models within this boundary: the L = 5 model and an L {approx} 12 model by Kaiser et al. (1987) and Farrell and Calvert (1989b). The main distinction between these two models is the longitudinal extent of the source location.
Real-Time Data Processing and Magnetic Field Pitch Angle Estimation of the JET Motional Stark Effect Diagnostic based on Kalman Filtering
Wu, Yue-Liang
2015-01-01T23:59:59.000Z
Treating the gravitational force on the same footing as the electroweak and strong forces, we present a quantum field theory (QFT) of gravity based on spinnic and scaling gauge symmetries. The so-called Gravifield sided on both locally flat non-coordinate space-time and globally flat Minkowski space-time is an essential ingredient for gauging global spinnic and scaling symmetries. The locally flat Gravifield space-time spanned by the Gravifield is associated with a non-commutative geometry characterized by a gauge-type field strength of Gravifield. A gauge invariant and coordinate independent action for the quantum gravity is built in the Gravifield basis, we derive equations of motion for all quantum fields with including the gravitational effect and obtain basic conservation laws for all symmetries. The equation of motion for Gravifield tensor is deduced in connection directly with the energy-momentum tensor. When the spinnic and scaling gauge symmetries are broken down to a background structure that posses...
Chu, Shih-I; Chu, Xi
2001-01-17T23:59:59.000Z
We present a self-interaction-free time-dependent density-functional theory (TDDFT) for nonperturbative treatment of multiphoton processes of many-electron molecular systems in intense laser fields. The time-dependent ...
Persistence of transition state structure in chemical reactions driven by fields oscillating in time
Galen T. Craven; Thomas Bartsch; Rigoberto Hernandez
2014-04-29T23:59:59.000Z
Chemical reactions subjected to time-varying external forces cannot generally be described through a fixed bottleneck near the transition state barrier or dividing surface. A naive dividing surface attached to the instantaneous, but moving, barrier top also fails to be recrossing-free. We construct a moving dividing surface in phase space over a transition state trajectory. This surface is recrossing-free for both Hamiltonian and dissipative dynamics. This is confirmed even for strongly anharmonic barriers using simulation. The power of transition state theory is thereby applicable to chemical reactions and other activated processes even when the bottlenecks are time-dependent and move across space.
Supplementary Material for The Shape-Time Random Field for Semantic Video Labeling
Massachusetts at Amherst, University of
]. We first describe the inference and learn- ing procedures for the temporal SCRF and STRF models in Section 3. 1. Temporal SCRF 1.1. Inference For the first frame (time t = 1), the SCRF is used for inference, since it does not depend on previous frames. Af- terward, inference in the temporal SCRF
Koch, Othmar
calculations of electronic structure. When a large number of states is involved, such a description be- comes The multiconfiguration time-dependent Hartree-Fock approach for the description of correlated few-electron dynamics ionization and electron spectra for the ground and first excited ionic channels are calculated for one
Jeong, Jaehoon
2009-05-15T23:59:59.000Z
in the form of an exact time domain propagator operating on the line voltage and current. It is shown that the analytical equations lead to a stable numerical method that can be used in the analysis of both homogeneous and inhomogeneous transmission lines. A...
Field-Deployable, High-Resolution, Time-of-Flight Aerosol Mass Spectrometer
Jimenez, Jose-Luis
as a powerful tool to characterize aerosols. A number of laser ablation instruments have been developed and trigger a laser ablation time-of-flight mass spectrometer, which determines the composition of the sized surface rather than by ablation lasers.8-10 At present, the most commonly used instrument of this type
A FEMTOSECOND-LEVEL FIBER-OPTICS TIMING DISTRIBUTION SYSTEM USING FREQUENCY-OFFSET INTERFEROMETRY
Staples, J.W.
2008-01-01T23:59:59.000Z
Figure 3: 2.8 km SLAC klystron gallery phase variation (km ?ber loop in the SLAC klystron gallery, exposed to fullperturbation of the klystron modulators. Mea- surement were
A FEMTOSECOND-LEVEL FIBER-OPTICS TIMING DISTRIBUTION SYSTEM USING FREQUENCY-OFFSET INTERFEROMETRY
Staples, J.W.
2008-01-01T23:59:59.000Z
sideband suppressed-carrier (DSSC) calibrate sig- nal isstabilized by injection of a DSSC calibrate signal. Figure 5signal. The FPGA generates a DSSC signal and injects it as
Chu, Shih-I
Time-dependent density-functional theory for strong-field multiphoton processes: Application 1997 We present a self-interaction-free time-dependent density-functional theory TDDFT. The theory is based on the extension of the time-dependent Kohn-Sham formalism. The time-dependent exchange
Chu, Shih-I
in crossed magnetic and electric fields Xiao-Min Tong and Shih-I Chu Department of Chemistry, University time-dependent study of three- dimensional Rydberg H atoms in crossed magnetic and electric fields magnetic and electric fields has attracted considerable attention in the last several years both
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Benioff, Paul
2009-01-01T23:59:59.000Z
This work is based on the field of reference frames based on quantum representations of real and complex numbers described in other work. Here frame domains are expanded to include space and time lattices. Strings of qukits are described as hybrid systems as they are both mathematical and physical systems. As mathematical systems they represent numbers. As physical systems in each frame the strings have a discrete Schrodinger dynamics on the lattices. The frame field has an iterative structure such that the contents of a stagejframe have images in a stagej-1(parent) frame. A discussion of parent frame images includes themore »proposal that points of stagejframe lattices have images as hybrid systems in parent frames. The resulting association of energy with images of lattice point locations, as hybrid systems states, is discussed. Representations and images of other physical systems in the different frames are also described.« less
Optical force on a discrete invisibility cloak in time-dependent fields
Chaumet, Patrick C.; Zolla, Frederic; Nicolet, Andre; Belkebir, Kamal [Institut Fresnel, CNRS, Aix-Marseille Universite, Campus de St-Jerome 13013 Marseille (France); Rahmani, Adel [Department of Mathematical Sciences, University of Technology, Sydney, Broadway NSW 2007 (Australia)
2011-09-15T23:59:59.000Z
We study, in time domain, the exchange of momentum between an electromagnetic pulse and a three-dimensional, discrete, spherical invisibility cloak. We find that a discrete cloak, initially at rest, would experience an electromagnetic force due to the pulse but would acquire zero net momentum and net displacement. On the other hand, we find that while the cloak may manage to conceal an object and shroud it from the electromagnetic forces associated with the pulse, the cloak itself can experience optomechanical stress on a scale much larger than the object would in the absence of the cloak. We also consider the effects of material dispersion and losses on the electromagnetic forces experienced by the cloak and show that they lead to a transfer of momentum from the pulse to the cloak.
Tureanu, Anca [High Energy Physics Division, Department of Physical Sciences, University of Helsinki and Helsinki Institute of Physics, P.O. Box 64, FIN-00014 Helsinki (Finland)
2006-09-15T23:59:59.000Z
In the framework of quantum field theory on noncommutative space-time with the symmetry group O(1,1)xSO(2), we prove that the Jost-Lehmann-Dyson representation, based on the causality condition taken in connection with this symmetry, leads to the mere impossibility of drawing any conclusion on the analyticity of the 2{yields}2-scattering amplitude in cos {theta}, {theta} being the scattering angle. Discussions on the possible ways of obtaining high-energy bounds analogous to the Froissart-Martin bound on the total cross section are also presented.
S. George; G. Audi; B. Blank; K. Blaum; M. Breitenfeldt; U. Hager; F. Herfurth; A. Herlert; A. Kellerbauer; H. -J. Kluge; M. Kretzschmar; D. Lunney; R. Savreux; S. Schwarz; L. Schweikhard; C. Yazidjian
2008-01-17T23:59:59.000Z
High-precision Penning trap mass measurements on the stable nuclide 27Al as well as on the short-lived radionuclides 26Al and 38,39Ca have been performed by use of radiofrequency excitation with time-separated oscillatory fields, i.e. Ramsey's method, as recently introduced for the excitation of the ion motion in a Penning trap, was applied. A comparison with the conventional method of a single continuous excitation demonstrates its advantage of up to ten times shorter measurements. The new mass values of 26,27Al clarify conflicting data in this specific mass region. In addition, the resulting mass values of the superallowed beta-emitter 38Ca as well as of the groundstate of the beta-emitter 26Al m confirm previous measurements and corresponding theoretical corrections of the ft-values.
Temperature dependent band offsets in PbSe/PbEuSe quantum well heterostructures
Simma, M.; Bauer, G.; Springholz, G. [Institut fuer Halbleiter und Festkoerperphysik, Johannes Kepler Universitaet, A-4040 Linz (Austria)
2012-10-22T23:59:59.000Z
The band offsets of PbSe/Pb{sub 1-x}Eu{sub x}Se multi-quantum wells grown by molecular beam epitaxy are determined as a function of temperature and europium content using temperature-modulated differential transmission spectroscopy. The confined quantum well states in the valence and conduction bands are analyzed using a k{center_dot}p model with envelope function approximation. From the fit of the experimental data, the normalized conduction band offset is determined as 0.45{+-}0.15 of the band gap difference, independently of Eu content up to 14% and temperature from 20 to 300 K.
Timing of structural growth at Northwest Stevens field as evidenced by Stevens channel geometries
Berkman, T.A. (ARCO Oil and Gas Co., Bakersfield, CA (United States))
1991-02-01T23:59:59.000Z
Stacked upper Miocene Stevens sandstone bodies at Northwest Stevens (Tule Elk) are the product of two coalescing turbidite channels which reflect the influence of growing structure during deposition. One channel can be traced from the south through ARCO's 555 zone unit, the 26R and 2B pools at Elk Hills, and into Northwest Stevens. The 800-ft-thick T' turbidite sands from this channel form offlapping geometries and structural/stratigraphic traps due to deposition across the rising northwest-plunging nose of the Northwest Stevens anticline. They are medium- to coarse-grained with abundant mudstone interbeds and are interpreted to represent a depositional channel fill which grades laterally to less permeable finer grained overbank deposits along the east side of Northwest Stevens. The second coeval channel can be traced from McKittrick through Asphalto and the 24Z pool at Elk Hills into Northwest Stevens, where it forms a 1,700-ft-thick sequence of 80 to 500-ft-thick sand packages at the 7R pool. Sand-shale ratios in these pebbly sandstones are nearly 9 to 1 with abundant conglomeratic interbeds. These channel sands display blocky electric log signatures, have lenticular geometries at the top of the sequence and offlapping geometries at the base, and document deposition in a structural low adjacent to the rising Northwest Stevens structure. The upper Miocene correlation point (UMPC) is sanded out at the 7R pool, indicating that turbidite sand deposition there persisted into lower Reef Ridge time. Well correlations indicate only minor erosive deposition and amalgamation; thus, the sand bodies at Northwest Stevens are additive to the section.
Eugene V. Stefanovich
2015-02-16T23:59:59.000Z
This book is an attempt to build a consistent relativistic quantum theory of interacting particles. In the first part of the book "Quantum electrodynamics" we follow rather traditional approach to particle physics. Our discussion proceeds systematically from the principle of relativity and postulates of quantum measurements to the renormalization in quantum electrodynamics. In the second part of the book "Quantum theory of particles" this traditional approach is reexamined. We find that formulas of special relativity should be modified to take into account particle interactions. We also suggest reinterpreting quantum field theory in the language of physical "dressed" particles. This formulation eliminates the need for renormalization and opens up a new way for studying dynamical and bound state properties of quantum interacting systems. The developed theory is applied to realistic physical objects and processes including the energy spectrum of the hydrogen atom, the decay law of moving unstable particles, and the electric field of relativistic electron beams. These results force us to take a fresh look at some core issues of modern particle theories, in particular, the Minkowski space-time unification, the role of quantum fields and renormalization as well as the alleged impossibility of action-at-a-distance. A new perspective on these issues is suggested. It can help to solve the old problem of theoretical physics -- a consistent unification of relativity and quantum mechanics.
Yusuke Tanimura; Denis Lacroix; Guillaume Scamps
2015-05-21T23:59:59.000Z
Given a set of collective variables, a method is proposed to obtain the associated conjugated collective momenta and masses starting from a microscopic time-dependent mean-field theory. The construction of pairs of conjugated variables is the first step to bridge microscopic and macroscopic approaches. The method is versatile and can be applied to study a large class of nuclear processes. An illustration is given here with the fission of $^{258}$Fm. Using the quadrupole moment and eventually higher-order multipole moments, the associated collective masses are estimated along the microscopic mean-field evolution. When more than one collective variable are considered, it is shown that the off-diagonal matrix elements of the inertia play a crucial role. Using the information on the quadrupole moment and associated momentum, the collective evolution is studied. It is shown that dynamical effects beyond the adiabatic limit are important. Nuclei formed after fission tend to stick together for longer time leading to a dynamical scission point at larger distance between nuclei compared to the one anticipated from the adiabatic energy landscape. The effective nucleus-nucleus potential felt by the emitted nuclei is finally extracted.
Ling, Junpu; He, Juntao, E-mail: hejuntao12@163.com; Zhang, Jiande; Jiang, Tao; Hu, Yi [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)
2014-09-15T23:59:59.000Z
An improved foilless Ku-band transit-time oscillator with low guiding magnetic field is proposed and investigated in this paper. With a non-uniform buncher and a coaxial TM{sub 02} mode dual-resonant reflector, this improved device can output gigawatt level Ku-band microwave with relatively compact radial dimensions. Besides the above virtue, this novel reflector also has the merits of high TEM reflectance, being more suitable for pre-modulating the electron beam and enhancing the conversion efficiency. Moreover, in order to further increase the conversion efficiency and lower the power saturation time, a depth-tunable coaxial collector and a resonant cavity located before the extractor are employed in our device. Main structure parameters of the device are optimized by particle in cell simulations. The typical simulation result is that, with a 380?kV, 8.2?kA beam guided by a magnetic field of about 0.6?T, 1.15?GW microwave pulse at 14.25?GHz is generated, yielding a conversion efficiency of about 37%.
Hamad, I Abou; Wipf, D O; Rikvold, P A
2010-01-01T23:59:59.000Z
We have recently proposed a new method for charging Li-ion batteries based on large-scale molecular dynamics studies (I. Abou Hamad et al, Phys. Chem. Chem. Phys., 12, 2740 (2010)). Applying an additional oscillating electric field in the direction perpendicular to the graphite sheets of the anode showed an exponential decrease in charging time with increasing amplitude of the applied oscillating field. Here we present new results exploring the effect on the charging time of changing the orientation of the oscillating field. Results for oscillating fields in three orthogonal directions are compared.
RodrÃguez, Rodolfo
AN EDDY CURRENT PROBLEM IN TERMS OF A TIME-PRIMITIVE OF THE ELECTRIC FIELD WITH NON-LOCAL SOURCE Abstract. The aim of this paper is to analyze a formulation of the eddy current problem in terms of a time and phrases: Eddy current problems, time-dependent electromagnetic problems, input current intensities
Shyamoli Chaudhuri
2014-12-11T23:59:59.000Z
We derive the Euclidean time formulation for the equilibrium canonical ensemble of the type IIA and type IIB superstrings, and the spin(32)$/{\\rm Z}_2$ heterotic string. We compactify on $R^8 \\times T^2$, and twist by the Neveu-Schwarz sector antisymmetric 2-form $B$-field potential, spontaneously breaking supersymmetry at low temperatures, while preserving the tachyon free low-energy gravitational field theory limit. We verify that the super partners of the massless dilaton-graviton multiplet obtain a mass which is linear in the temperature. In addition, we show that the free energy for the superstring canonical ensemble at weak coupling is always strongly convergent in the ultraviolet, high-temperature, regime dominated by the highest mass level number states. We derive the precise form of the exponential suppression as a linear power of the mass level, which erases the exponential Hagedorn growth of the degeneracies as the square root of mass level number. Finally, we close a gap in previous research giving an unambiguous derivation of the normalization of the one-loop vacuum energy density of the spin(32)$/Z_2$ perturbative heterotic string theory. Invoking the O(32) type IB--heterotic strong-weak duality, we match the normalization of the one loop vacuum energy densities of the $T$-dual O(32) type IA open and closed string with that of the Spin(32)$/Z_2$ heterotic string on $R^9 \\times S^1$, for values of the compactification radius, $R_{\\rm [O(32)]}, ~ R_{\\rm IB}$ $>>$ $ \\alpha^{\\prime 1/2}$, with $R_{\\rm IA} $ $type IA thermal solitonic winding spectrum is a simple model for finite temperature pure QCD, transitioning above the critical duality phase transformation temperature to the deconfined ensemble of thermally excited IB gluons.
LARGE DEXTRAL OFFSET ACROSS OWENS VALLEY, CALIFORNIA FROM 148 MA TO 1872 A.D.
Lee, Jeff
River Plain Tertiary volcanic cover Cascades San A n d reasf. Pacific Plate Juan de Fuca Plate Colorado, the prevail- ing view has been that offset across the valley is no more than a few km. This was based on Snake
Commonality in Complex Product Families: Implications of Divergence and Lifecycle Offsets
de Weck, Olivier L.
Commonality in Complex Product Families: Implications of Divergence and Lifecycle Offsets by Ryan C Committee #12;2 #12;3 Commonality in Complex Product Families: Implications of Divergence and Lifecycle product family planning and lifecycle management, and ultimately, to improving corporate profitability
The Role of Offsets in Meeting Duke University's Commitment to `Climate
Zhou, Pei
................................................................................................................................................21 4. Greenhouse Gas Markets: the State of Play this Report This report examines the potential role of carbon offsets in meeting Duke University`s and other from within North Carolina, the international and national market context, and the potential
Band offsets at zincblende-wurtzite GaAs nanowire sidewall surfaces P. Capiod,1
Dunin-Borkowski, Rafal E.
Band offsets at zincblende-wurtzite GaAs nanowire sidewall surfaces P. Capiod,1 T. Xu,1,2 J. P. Nys of zincblende (ZB)-wurtzite (WZ) GaAs nanowires are investigated by scanning tunneling spectroscopy and density inclusions consisting of zinc-blende (ZB) and wurtzite (WZ) segments form during the growth of NWs and where
A Programmable 210 V Offset Rail-to-Rail GMC Filter
Rincon-Mora, Gabriel A.
milli-Volts glitch at the input of a high- speed high-resolution comparator, for instance, may1 A Programmable 210 µV Offset Rail-to-Rail GMC Filter H. Pooya Forghani-zadeh1 , Student Member. Programmability is also a feature of growing significance because high performance state-of-the-art systems must
CARBON SEQUESTRATION IN ARABLE SOILS IS LIKELY TO INCREASE NITROUS OXIDE EMISSIONS, OFFSETTING
CARBON SEQUESTRATION IN ARABLE SOILS IS LIKELY TO INCREASE NITROUS OXIDE EMISSIONS, OFFSETTING in strategies for climate protection. 1. Introduction Carbon sequestration has been highlighted recently concentration of carbon dioxide (CO2) in the atmo- sphere include sequestering carbon (C) in soils
Chu, Xi; Chu, Shih-I
2001-11-14T23:59:59.000Z
We present a time-dependent density-functional theory (TDDFT) with proper asymptotic long-range potential for nonperturbative treatment of multiphoton processes of many-electron molecular systems in intense laser fields. ...
Challacombe, Matt [Los Alamos National Laboratory
2009-01-01T23:59:59.000Z
An algorithm for solution of the Time-Dependent Self-Consistent-Field (TD-SCF) equations is developed, based on dual solution channels for non-linear optimization of the Tsiper functional [J.Phys.B, 34 L401 (2001)]. This formulation poses the TD-SCF problem as two Rayleigh quotients, coupled weakly through biorthogonality. Convergence rates for the Random Phase Approximation (RPA) are found to be equivalent to the Tamm-Dancoff approximation (TDA). Moreover, the variational nature of the quotient is robust to approximation errors, allowing linear scaling solution to the bulk limit of the RPA matrix-eigenvalue and exchange operator problem for molecular wires with extended conjugation, including polyphenylene vinylene and the (4,3) nanotube.
Barrash, Warren
A field comparison of Fresnel zone and ray-based GPR attenuation-difference tomography for time the medium. These sensitivities occupy the first Fresnel zone, account for the finite frequency nature
Ho, Tak-San; Wang, Kwanghsi; Chu, Shih-I
1986-03-01T23:59:59.000Z
A Floquet-Liouville supermatrix (FLSM) approach is presented for nonperturbative treatment of the time development of the density-matrix operator of atoms and molecules exposed to intense polychromatic fields. By extending ...
Khare, H. S.; Burris, D. L. [126 Spencer Laboratory, Department of Mechanical Engineering, University of Delaware, Newark, Delaware 19716 (United States)
2013-05-15T23:59:59.000Z
One of the major challenges in understanding and controlling friction is the difficulty in bridging the length and time scales of macroscale contacts and those of the single asperity interactions they comprise. While the atomic force microscope (AFM) offers a unique ability to probe tribological surfaces in a wear-free single-asperity contact, instrument calibration challenges have limited the usefulness of this technique for quantitative nanotribological studies. A number of lateral force calibration techniques have been proposed and used, but none has gained universal acceptance due to practical considerations, configuration limitations, or sensitivities to unknowable error sources. This paper describes a simple extension of the classic wedge method of AFM lateral force calibration which: (1) allows simultaneous calibration and measurement on any substrate, thus eliminating prior tip damage and confounding effects of instrument setup adjustments; (2) is insensitive to adhesion, PSD cross-talk, transducer/piezo-tube axis misalignment, and shear-center offset; (3) is applicable to integrated tips and colloidal probes; and (4) is generally applicable to any reciprocating friction coefficient measurement. The method was applied to AFM measurements of polished carbon (99.999% graphite) and single crystal MoS{sub 2} to demonstrate the technique. Carbon and single crystal MoS{sub 2} had friction coefficients of {mu}= 0.20 {+-} 0.04 and {mu}= 0.006 {+-} 0.001, respectively, against an integrated Si probe. Against a glass colloidal sphere, MoS{sub 2} had a friction coefficient of {mu}= 0.005 {+-} 0.001. Generally, the measurement uncertainties ranged from 10%-20% and were driven by the effect of actual frictional variation on the calibration rather than calibration error itself (i.e., due to misalignment, tip-offset, or probe radius).
Using Measurements of Fill Factor at High Irradiance to Deduce Heterobarrier Band Offsets: Preprint
Olson, J. M.; Steiner, M. A.; Kanevce, A.
2011-07-01T23:59:59.000Z
Using a 2D device simulation tool, we examine the high irradiance behavior of a single junction, GaAs concentrator cell as a function of the doping in the back surface confinement layer. The confinement layer is designed to be a barrier for both holes and electrons in the base of the solar cell. For a p-type base we show that the FF of the cell at high concentrations is a strong function of both the magnitude of the valence band offset and the doping level in the barrier. In short, for a given valence band offset (VBO), there is a critical barrier doping, below which the FF drops rapidly with lower doping. This behavior is confirmed experimentally for a GaInP/GaAs double heterostructure solar cell where the critical doping concentration (at 500 suns) in the back surface confinement layer is ~1e18 cm-3 for a VBO of 300 meV.
2001-01-01T23:59:59.000Z
Real-Time Laser-Based Non-Intrusive Detection System forof a laser-based non-intrusive detection system for real-Real-Time Laser-Based Non-Intrusive Detection System for
Cheng, Harry H.; Shaw, Ben; Palen, Joe; Wang, Zhaoqing; Chen, Bo
2002-01-01T23:59:59.000Z
Real-Time Laser-Based Non-Intrusive Detection System forJoe Palen, "A Laser-Based Non-Intrusive Detection System forReal-Time Laser-Based Non-Intrusive Detection System for
Rossi, D. M., E-mail: rossi@nscl.msu.edu; Davis, M.; Ringle, R.; Rodriguez, J. A.; Ryder, C. A.; Schwarz, S.; Sumithrarachchi, C.; Zhao, S. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Minamisono, K., E-mail: minamiso@nscl.msu.edu; Barquest, B. R.; Bollen, G.; Hughes, M.; Strum, R.; Tarazona, D. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Cooper, K.; Hammerton, K.; Mantica, P. F.; Morrissey, D. J. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Chemistry, Michigan State University, East Lansing, Michigan 48824 (United States)
2014-09-15T23:59:59.000Z
A new data acquisition system including a Field Programmable Gate Array (FPGA) based time-resolved scaler was developed for laser-induced fluorescence and beam bunch coincidence measurements. The FPGA scaler was tested in a collinear laser-spectroscopy experiment on radioactive {sup 37}K at the BEam COoler and LAser spectroscopy (BECOLA) facility at the National Superconducting Cyclotron Laboratory at Michigan State University. A 1.29 ?s bunch width from the buncher and a bunch repetition rate of 2.5 Hz led to a background suppression factor of 3.1 × 10{sup 5} in resonant photon detection measurements. The hyperfine structure of {sup 37}K and its isotope shift relative to the stable {sup 39}K were determined using 5 × 10{sup 4} s{sup ?1} {sup 37}K ions injected into the BECOLA beam line. The obtained hyperfine coupling constants A({sup 2}S{sub 1/2}) = 120.3(1.4) MHz, A({sup 2}P{sub 1/2}) = 15.2(1.1) MHz, and A({sup 2}P{sub 3/2}) = 1.4(8) MHz, and the isotope shift ??{sup 39,} {sup 37} = ?264(3) MHz are consistent with the previously determined values, where available.
Miyagi, Haruhide; Bojer Madsen, Lars [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)] [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C (Denmark)
2014-04-28T23:59:59.000Z
The time-dependent restricted-active-space self-consistent-field singles (TD-RASSCF-S) method is presented for investigating TD many-electron dynamics in atoms and molecules. Adopting the SCF notion from the muticonfigurational TD Hartree-Fock (MCTDHF) method and the RAS scheme (single-orbital excitation concept) from the TD configuration-interaction singles (TDCIS) method, the TD-RASSCF-S method can be regarded as a hybrid of them. We prove that, for closed-shell N{sub e}-electron systems, the TD-RASSCF-S wave function can be fully converged using only N{sub e}/2 + 1 ? M ? N{sub e} spatial orbitals. Importantly, based on the TD variational principle, the converged TD-RASSCF-S wave function with M = N{sub e} is more accurate than the TDCIS wave function. The accuracy of the TD-RASSCF-S approach over the TDCIS is illustrated by the calculation of high-order harmonic generation spectra for one-dimensional models of atomic helium, beryllium, and carbon in an intense laser pulse. The electronic dynamics during the process is investigated by analyzing the behavior of electron density and orbitals. The TD-RASSCF-S method is accurate, numerically tractable, and applicable for large systems beyond the capability of the MCTDHF method.
Influence of GaAs surface termination on GaSb/GaAs quantum dot structure and band offsets
Zech, E. S.; Chang, A. S.; Martin, A. J.; Canniff, J. C.; Millunchick, J. M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Lin, Y. H. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)] [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Goldman, R. S. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States) [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)
2013-08-19T23:59:59.000Z
We have investigated the influence of GaAs surface termination on the nanoscale structure and band offsets of GaSb/GaAs quantum dots (QDs) grown by molecular-beam epitaxy. Transmission electron microscopy reveals both coherent and semi-coherent clusters, as well as misfit dislocations, independent of surface termination. Cross-sectional scanning tunneling microscopy and spectroscopy reveal clustered GaSb QDs with type I band offsets at the GaSb/GaAs interfaces. We discuss the relative influences of strain and QD clustering on the band offsets at GaSb/GaAs interfaces.
Emittance growth due to beam-beam effects with a static offset in collision in the LHC
Pieloni, T; Qiang, J
2010-01-01T23:59:59.000Z
Under nominal operational conditions, the LHC bunches experience small unavoidable offset at the collision points caused by long range beam-beam interactions. Although the geometrical loss of luminosity is small, one may have to consider an increase of the beam transverse emittance, leading to a deterioration of the experimental conditions. In this work we evaluate and understand the dynamics of beam-beam interactions with static offsets at the collision point. A study of the emittance growth as a function of the offset amplitude in collisions is presented. Moreover, we address the effects coming from the beam parameters such as the initial transverse beam size, bunch intensity and tune.
Moon, Un-Ku
-converted signal in the form of a DC offset. Coupling of the LO to the LNA and RF port of the mixer cause static conversion mixer incorporating adaptive offset cancellation. The basic circuit structure is that of a Gilbert cell mixer. Offsets are cancelled by dynamically varying the bias on the loads, which are designed
A frequency compensated real time DSP GMSK modem
Aziz, Ahsan Ul
1998-01-01T23:59:59.000Z
In low-earth-orbit (LEO) satellite applications, frequency offsets due to Doppler can be large, and can degrade significantly receiver performance. In this thesis real-time implementation trade-offs are analyzed for a GMSK modem operating under...
Brizard, Alain J. [Department of Physics, Saint Michael's College, Colchester, Vermont 05439 (United States); Guillebon, Loiec de [Centre de Physique Theorique Aix-Marseille Universite, CNRS (UMR 7332), 13288 Marseille Cedex 09 (France)
2012-09-15T23:59:59.000Z
The geometric analysis of the gyromotion for charged particles in a time-dependent magnetic field by Liu and Qin [Phys. Plasmas 18, 072505 (2011)] is reformulated in terms of the spatial angles that represent the instantaneous orientation of the magnetic field. This new formulation, which includes the equation of motion for the pitch angle, clarifies the decomposition of the gyroangle-averaged equation of motion for the gyrophase into its dynamic and geometric contributions.
Brandt, Riley E.
The development of cuprous oxide (Cu [subscript 2]O) photovoltaics (PVs) is limited by low device open-circuit voltages. A strong contributing factor to this underperformance is the conduction-band offset between Cu ...
Xavier Busch
2014-11-06T23:59:59.000Z
The two main predictions of quantum field theory in curved space-time, namely Hawking radiation and cosmological pair production, have not been directly tested and involve ultra high energy configurations. As a consequence, they should be considered with caution. Using the analogy with condensed matter systems, their analogue versions could be tested in the lab. Moreover, the high energy behavior of these systems is known and involves dispersion and dissipation, which regulate the theory at short distances. When considering experiments which aim to test the above predictions, there will also be a competition between the stimulated emission from thermal noise and the spontaneous emission out of vacuum. In order to measure these effects, one should thus compute the consequences of UV dispersion and dissipation, and identify observables able to establish that the spontaneous emission took place. In this thesis, we first analyze the effects of dispersion and dissipation on both Hawking radiation and pair particle production. To get explicit results, we work in the context of de Sitter space. Using the extended symmetries of the theory in such a background, exact results are obtained. These are then transposed to the context of black holes using the correspondence between de Sitter space and the black hole near horizon region. To introduce dissipation, we consider an exactly solvable model producing any decay rate. We also study the quantum entanglement of the particles so produced. In a second part, we consider explicit condensed matter systems, namely Bose Einstein condensates and exciton-polariton systems. We analyze the effects of dissipation on entanglement produced by the dynamical Casimir effect. As a final step, we study the entanglement of Hawking radiation in the presence of dispersion for a generic analogue system.
Alex Kaivarainen
2006-07-14T23:59:59.000Z
New concept of Bivacuum is introduced, as a dynamic matrix of the Universe, composed from sub-quantum particles and antiparticles, forming vortical structures. These structures are presented by continuum of dipoles, each dipole containing a pair of correlated torus and antitorus: V(+) and V(-) of the opposite energy/mass, spin, charge and magnetic moments, compensating each other. The rest mass and charge of sub-elementary fermions or antifermions is a result of Bivacuum dipoles opposite symmetry shifts. Their fusion to triplets follows by elementary particles and antiparticles origination. The [corpuscle (C) - wave (W)] duality is a result of correlated beats between the 'actual' and 'complementary' states of sub-elementary fermions of triplets. It is shown, that Principle of least action, the 2d and 3d laws of thermodynamics can be a consequences of forced combinational resonance between positive and negative virtual pressure waves (VPW+/-) of Bivacuum and [C-W] pulsation of elementary particles. The quantum entanglement, mediated by virtual microtubules, composed from Bivacuum dipoles, connecting remote particles, is a result of such Bivacuum-matter interaction. The pace of time for any closed system is determined by pace of kinetic energy change of this system. The proposed mechanism of overunity devices can be provided by the electrons acceleration, induced by their resonant interaction with high frequency positive and negative VPW+/- in pull-in range conditions. The latter can be excited by pulsing currents and fields. The mechanism of overheating and cold fusion in electrolytic cells without violation of energy conservation is proposed also.
Wysin, Gary
styrofoam ball? a. It has a negative net charge b. It has zero net charge. c. It has positive net charge. d at finite x where the electric field is zero. c) (8) Determine the magnitude of the net electric field. Its net charge changes when then rods are placed near it. 2. (6) An excess charge of -88 pC is placed
Salah Menouar; Mustapha Maamache; Jeong Ryeol Choi
2010-10-14T23:59:59.000Z
A general treatment of the quantal time-dependent coupled oscillators in presence of the variable magnetic field is presented. The treatment is based on the use of an alternative canonical transformations, time-dependent unitary transformations and the invariant methods. Exact wave functions for Schr\\"{o}dinger equations of this system are constructed.We applied our theory to a particular case and, co,sequently, showed that our results recovers to the perviously known one.
Halden In-Reactor Test to Exhibit PWR Axial Offset Anomaly
P.Bennett, B. Beverskog, R.Suther
2004-12-01T23:59:59.000Z
Many PWRs have encountered the axial offset anomaly (AOA) since the early 1990s, and these experiences have been reported widely. AOA is a phenomenon associated with localized boron hideout in corrosion product deposits (crud) on fuel surfaces. Several mitigation approaches have been developed or are underway to either delay the onset of AOA or avoid it entirely. This study describes the first phase of an experimental program designed to investigate whether the use of enriched boric acid (EBA) in the reactor coolant can mitigate AOA.
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (Million Cubic Feet) Natural Gas Delivered toNew6 ANL/EVS/NL-06-10CSU -GlobusOnline/HPSSweOffset
Rotating black hole in asymptotic de Sitter space: Perturbation of the space-time with spin fields
Khanal, U.
1983-09-15T23:59:59.000Z
The Newman-Penrose formalism is used to work with gravitational, electromagnetic, and Dirac field perturbations of the Kerr--de Sitter space. It is shown that the resulting equations are separable, and the radial parts (for the massless fields) combine into a master equation resembling that of Teukolsky. This master equation includes the Teukolsky equation and the equation arising from the de Sitter--Schwarzschild universe, and can be reduced to these cases under appropriate limiting conditions. Finally, the radial parts of the electromagnetic and neutrino fields are transformed to the form of the one-dimensional barrier-penetration equation.
Paris-Sud XI, Université de
CAMI-AFT: A SCIENTIFIC FIELD EXPERIMENT TO CALIBRATE REAL-TIME MONITORING SYSTEMS DEDICATED the source energy to the sensor energy. KEYWORDS: Microseismic monitoring, Post-mining risks. RESUME : les TO THE MANAGEMENT OF POST-MINING RISKS CONTRUCCI Isabelle1 , KLEIN Emmanuelle1 , BIGARRE Pascal1 , LIZEUR Armand1
Smith, David E.
Tracking of the Mars Global Surveyor spacecraft has been used to measure changes in the long-wavelength gravity field of Mars and to estimate the seasonal mass of carbon dioxide that is deposited in the polar regions each ...
Venables, John
methods. Programs are coded in MatlabP ® P6.5; the calculation is fast, and the evolving diffusion field and island shapes can be seen visually in the form of MatLab movies. Capture numbers are calculated
Time-resolved observation of discrete and continuous MHD dynamo in the reversed-field pinch edge
Ji, H.; Almagri, A.F.; Prager, S.C.; Sarff, J.S.
1994-01-06T23:59:59.000Z
We report the first experimental verification of the MHD dynamo in the RFP. A burst of magnetohydrodynamic (MHD) dynamo electric field is observed during the sawtooth crash, followed by an increase in the local parallel current in the MST RFP edge. By measuring each term, the parallel MHD mean-field Ohm`s law is observed to hold within experimental error bars both between and during sawtooth crashes.
Tachyonic field interacting with Scalar (Phantom) Field
Surajit Chattopadhyay; Ujjal Debnath
2009-01-29T23:59:59.000Z
In this letter, we have considered the universe is filled with the mixture of tachyonic field and scalar or phantom field. If the tachyonic field interacts with scalar or phantom field, the interaction term decays with time and the energy for scalar field is transferred to tachyonic field or the energy for phantom field is transferred to tachyonic field. The tachyonic field and scalar field potentials always decrease, but phantom field potential always increases.
McDonald, Kirk
than the retarded forms of the Coulomb and the BiotSavart laws. Of course, it was Maxwell who first of the Coulomb and BiotSavart laws as their leading terms, but their relation to radiation is not as manifest greater emphasis to the radiation fields. This article presents a derivation of the various expressions
Sorina Lazanu; Ionel Lazanu
2006-11-08T23:59:59.000Z
The bulk displacement damage in the detector, produces effects at the device level that limits the long time utilisation of detectors as position sensitive devices and thus the lifetime of detector systems. So, the prediction of time behaviour of detectors in hostile radiation environments represents a very useful tool. In this contribution we predict the time degradation of silicon detectors in the radiation environments expected in the LHC machine upgrade in luminosity and energy as SLHC, for detectors fabricated from silicon crystals obtained by different growth technologies, in the frame of the model developed by the authors, and which takes into account the contribution of primary defects.
.5 km/s Depth(km) Offset (km) True velocity model Depth(km) Offset (km) Migration velocity model Figure 2. Kirchhoff depth migration image (a), RTM depth image (b), and IM depth imageReducedTimeMigrationandInterferometricMigrationofCDPData ABSTRACT One of the difficulties in seeing beneath salt is that the migration velocity in the salt
Rai-Dastidar, T K; Dastidar, Krishna Rai
1999-01-01T23:59:59.000Z
It has been demonstrated in a recent paper (Mod.Phys.Lett. A13, 1265 (1998); hep-th/9902020) that the existence of a non-thermodynamic arrow of time at the atomic level is a fundamental requirement for conservation of energy in matter-radiation interaction. Since the universe consists of two things only --- energy and massive matter --- we argue that as a consequence of this earlier result, particles and antiparticles must necessarily move in opposite directions in time. Our result further indicates that the CPT theorem can be extended to cover non-local gauge fields.
Pryor, C. [Sierra Center for Physics, 939 North Van Ness Avenue, Suite 2, Fresno, California 93728 (United States)] [Sierra Center for Physics, 939 North Van Ness Avenue, Suite 2, Fresno, California 93728 (United States)
1996-02-01T23:59:59.000Z
The phase diagram of an SU(2){sub {ital L}}{times}SU(2){sub {ital R}} lattice Higgs-Yukawa model with finite {lambda} is constructed using mean field theory. The phase diagram bears a superficial resemblance to that for {lambda}={infinity}; however, as {lambda} is decreased the paramagnetic region shrinks in size. For small {lambda} the phase transitions remain second order, and no new first order transitions are seen. {copyright} {ital 1996 The American Physical Society.}
Offset-free rail-to-rail derandomizing peak detect-and-hold circuit
DeGeronimo, Gianluigi (Nesconset, NY); O'Connor, Paul (Bellport, NY); Kandasamy, Anand (Coram, NY)
2003-01-01T23:59:59.000Z
A peak detect-and-hold circuit eliminates errors introduced by conventional amplifiers, such as common-mode rejection and input voltage offset. The circuit includes an amplifier, three switches, a transistor, and a capacitor. During a detect-and-hold phase, a hold voltage at a non-inverting in put terminal of the amplifier tracks an input voltage signal and when a peak is reached, the transistor is switched off, thereby storing a peak voltage in the capacitor. During a readout phase, the circuit functions as a unity gain buffer, in which the voltage stored in the capacitor is provided as an output voltage. The circuit is able to sense signals rail-to-rail and can readily be modified to sense positive, negative, or peak-to-peak voltages. Derandomization may be achieved by using a plurality of peak detect-and-hold circuits electrically connected in parallel.
Swisher, J.N.
1991-01-01T23:59:59.000Z
This dissertation presents a case study analysis in which the costs to a US electric utility of reducing its carbon dioxide (CO{sub 2}) emissions are compared with the costs of carbon-saving forestry projects in Costa Rica and Guatemala. The results show that a large electric utility in the south-central US would find it relatively inexpensive, even profitable given a conducive regulatory treatment, to reduce its CO{sub 2} emissions by a few percent over the next ten years, through direct investment in energy end-use efficiency improvements. In comparison, the costs of the forestry projects studied in Central America range from $1/TC to a worst-case value of about $55/TC, with most project costs between $5 and $13/TC, depending on the type of project, the climate, and the opportunity cost of land. The total amount of CO{sub 2} storage potential is significant, about 100 million tons per country, but not enough to suggest that forestry can offset more than a few percent of global CO{sub 2} emissions from fossil fuel use. These case studies suggest that international trade in the environmental service of reducing global CO{sub 2} accumulation could have significant economic and ecological benefits. A transaction in which a utility pays for forestry projects in exchange for credit against an emission reduction policy is an example of an international carbon emission offset (ICEO). ICEO's could provide a currency for funding carbon-saving services as a way to comply with national policies to reduce CO{sub 2} emissions, as long as compliance is allowed through investments in other countries. This type of North-South transfer is necessary to reconcile economic efficiency and international equity, because of the disparity between the national allocations of responsibility for greenhouse gas emissions and opportunities for emission reductions.
Bernadett, Lauren
2013-01-01T23:59:59.000Z
offset credits for installing “a biogas control system thatemissions by installing biogas control systems (BCS), whichin exchange for installing biogas control systems (BCS), a
C. J. Schrijver; M. L. DeRosa; T. Metcalf; G. Barnes; B. Lites; T. Tarbell; J. McTiernan; G. Valori; T. Wiegelmann; M. S. Wheatland; T. Amari; G. Aulanier; P. Demoulin; M. Fuhrmann; K. Kusano; S. Regnier; J. K. Thalmann
2007-11-30T23:59:59.000Z
Solar flares and coronal mass ejections are associated with rapid changes in field connectivity and powered by the partial dissipation of electrical currents in the solar atmosphere. A critical unanswered question is whether the currents involved are induced by the motion of pre-existing atmospheric magnetic flux subject to surface plasma flows, or whether these currents are associated with the emergence of flux from within the solar convective zone. We address this problem by applying state-of-the-art nonlinear force-free field (NLFFF) modeling to the highest resolution and quality vector-magnetographic data observed by the recently launched Hinode satellite on NOAA Active Region 10930 around the time of a powerful X3.4 flare. We compute 14 NLFFF models with 4 different codes and a variety of boundary conditions. We find that the model fields differ markedly in geometry, energy content, and force-freeness. We discuss the relative merits of these models in a general critique of present abilities to model the coronal magnetic field based on surface vector field measurements. For our application in particular, we find a fair agreement of the best-fit model field with the observed coronal configuration, and argue (1) that strong electrical currents emerge together with magnetic flux preceding the flare, (2) that these currents are carried in an ensemble of thin strands, (3) that the global pattern of these currents and of field lines are compatible with a large-scale twisted flux rope topology, and (4) that the ~10^32 erg change in energy associated with the coronal electrical currents suffices to power the flare and its associated coronal mass ejection.
Palazzo, S.; Vagliasindi, G.; Arena, P. [Dipartimento di Ingegneria Elettrica Elettronica e dei Sistemi, Universita degli Studi di Catania, 95125 Catania (Italy); Murari, A. [Consorzio RFX-Associazione EURATOM ENEA per la Fusione, I-35127 Padova (Italy); Mazon, D. [Association EURATOM-CEA, CEA Cadarache, 13108 Saint-Paul-lez-Durance (France); De Maack, A. [Arts et Metiers Paris Tech Engineering College (ENSAM), 13100 Aix-en-Provence (France); Collaboration: JET-EFDA Contributors
2010-08-15T23:59:59.000Z
In the past years cameras have become increasingly common tools in scientific applications. They are now quite systematically used in magnetic confinement fusion, to the point that infrared imaging is starting to be used systematically for real-time machine protection in major devices. However, in order to guarantee that the control system can always react rapidly in case of critical situations, the time required for the processing of the images must be as predictable as possible. The approach described in this paper combines the new computational paradigm of cellular nonlinear networks (CNNs) with field-programmable gate arrays and has been tested in an application for the detection of hot spots on the plasma facing components in JET. The developed system is able to perform real-time hot spot recognition, by processing the image stream captured by JET wide angle infrared camera, with the guarantee that computational time is constant and deterministic. The statistical results obtained from a quite extensive set of examples show that this solution approximates very well an ad hoc serial software algorithm, with no false or missed alarms and an almost perfect overlapping of alarm intervals. The computational time can be reduced to a millisecond time scale for 8 bit 496x560-sized images. Moreover, in our implementation, the computational time, besides being deterministic, is practically independent of the number of iterations performed by the CNN - unlike software CNN implementations.
Sato, Fumihiro; Shinohe, Kohta; Takura, Tetsuya [Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aramaki aza, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Matsuki, Hidetoshi [Graduate School of Biomedical Engineering, Tohoku University, 6-6-05 Aoba, Aramaki aza, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Yamada, Syogo [Graduate School of Medicine, Tohoku University, 1-1 Seiryou-cyo, Aoba-ku, Sendai 980-8575 (Japan); Sato, Tadakuni [NEC Tokin Corp., 6-7-1 Koriyama, Taihaku-ku, Sendai 982-8510 (Japan)
2009-04-01T23:59:59.000Z
In radiation therapy, excessive radiation occurs because the actual delivered dose to the tumor is unknown. To overcome this problem, we need a system in which the delivered dose is measured inside the body, and the dose data are transmitted from the inside to the outside of the body. In this study, a wireless communication system, using magnetic fields was studied, and an internal circuit for obtaining radiation dose data from an x-ray detector was examined. As a result, a communication distance of 200 mm was obtained. An internal circuit was developed, and a signal transmission experiment was performed using the wireless communication system. As a result, the radiation dose data from an x-ray detector was transmitted over a communication distance of 200 mm, and the delivered dose was determined from the received signal.
Feenstra, Randall
1 Band Offsets of InGaP/GaAs Heterojunctions by Scanning Tunneling Spectroscopy Y. Dong and R. M Abstract Scanning tunneling microscopy and spectroscopy are used to study InGaP/GaAs heterojunctions computation of the tunnel current. Curve fitting of theory to experiment is performed. Using an InGaP band gap
Single-band and Dual-band Beam Switching Systems and Offset-fed Beam Scanning Reflectarray
Lee, Jungkyu
2012-07-16T23:59:59.000Z
for multi-band applications. A modified Butler matrix is used to reduce a size and a sidelobe level. The bandwidth of the microstrip antenna is inherently small. A broadband circularly polarized microstrip antenna with dual-offset feedlines is introduced...
Dynamic and Static Characteristics of a Rocker-Pivot, Tilting-Pad Bearing with 50% and 60% Offsets.
Kulhanek, Chris David
2012-02-14T23:59:59.000Z
Static performance and rotordynamic coefficients are provided for a rocker-pivot, tilting-pad journal bearing with 50 and 60 percent offset pads in a load-between-pad configuration. The bearing uses leading-edge-groove lubrication and has...
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5(Million Cubic Feet) Oregon (Including Vehicle Fuel) (MillionStructural Basis of WntSupportB 18B()The57 Please note that3 IrimpanTime to Start3, NUMBER
Ling, Junpu; Zhang, Jiande; He, Juntao, E-mail: hejuntao12@163.com; Wang, Lei; Deng, Bingfang [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)
2014-08-15T23:59:59.000Z
Based on the theoretical analysis of the intense relativistic electron beam propagation in the coaxial drift-tube, a focusing electrode and a coaxial reflector is proposed to lessen the demand of the coaxial Ku-band foilless transit-time oscillator (TTO) for the guiding magnetic field. Moreover, a Ku-band TTO with the focusing electrode and the coaxial reflector is designed and studied by particle in cell simulation. When the diode voltage is 390 kV, the beam current 7.8 kA, and the guiding magnetic field is only 0.3 T, the device can output 820 MW microwave pulse at 14.25 GHz by means of the simulation. However, for the device without them, the output power is only 320 MW. The primary experiments are also carried out. When the guiding magnetic field is 0.3 T, the output power of the device with the focusing electrode and the coaxial reflector is double that of the one without them. The simulation and experimental results prove that the focusing electrode and the coaxial reflector are effective on reducing the guiding magnetic field of the device.
Rucci, A.; Vasco, D.W.; Novali, F.
2010-04-01T23:59:59.000Z
Deformation in the overburden proves useful in deducing spatial and temporal changes in the volume of a producing reservoir. Based upon these changes we estimate diffusive travel times associated with the transient flow due to production, and then, as the solution of a linear inverse problem, the effective permeability of the reservoir. An advantage an approach based upon travel times, as opposed to one based upon the amplitude of surface deformation, is that it is much less sensitive to the exact geomechanical properties of the reservoir and overburden. Inequalities constrain the inversion, under the assumption that the fluid production only results in pore volume decreases within the reservoir. We apply the formulation to satellite-based estimates of deformation in the material overlying a thin gas production zone at the Krechba field in Algeria. The peak displacement after three years of gas production is approximately 0.5 cm, overlying the eastern margin of the anticlinal structure defining the gas field. Using data from 15 irregularly-spaced images of range change, we calculate the diffusive travel times associated with the startup of a gas production well. The inequality constraints are incorporated into the estimates of model parameter resolution and covariance, improving the resolution by roughly 30 to 40%.
Edinburgh, University of
scheme for process- ing a multicomponent vertical seismic profile (VSP). This sequence is applied near-offset vertical seismic profiles (VSPs) are of particular value since the directly trans- mitted-component near-offset VSP for seismic anisotropy Colin MacBeth*, Xiang-Yang Li*, Xinwu Zeng*, Dale Coxs, and John
Alexandrova, Ivana
and to invest in emerging technologies and proven ways of negating a carbon footprint. Of course, reducing48 8 Lighten the LoadTM Carbon Neutral Laundry Rooms Mac-Gray Campus Solutions recognizes that carbon offsetting is not without controversy, but also understands that offsetting is a viable short
Coelho, R.; Alves, D. [Associacao Euratom/IST, Centro de Fusao Nuclear, 1049-001 Lisboa (Portugal)
2008-03-12T23:59:59.000Z
The real-time amplitude estimation of selective harmonics from an Avalanche Photo Diode (APD) signal of a Motion Stark Effect diagnostic is addressed using a Kalman filter. The proposed technique is shown to be much more robust and provide less noisy estimates than a lock-in amplifier scheme. In addition, the negative impact of Edge Localised Modes (ELMs) is minimized, reducing significantly the biasing in the amplitude estimation and ultimately allowing for the pitch angle estimation in the vicinity of the ELM. The inherent biasing in the amplitude estimation due to the 50Hz modulation in the NBI power grid is also easily circumvented with such a technique, rendering dispensable any further filtering of the data.
Coelho, R.; Alves, D. [Instituto de Plasmas e Fusao Nuclear, Associacao Euratom/IST, 1049-001 Lisboa (Portugal); Hawkes, N.; Brix, M. [Euratom/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon, OX14 3DB (United Kingdom); Collaboration: JET EFDA Contributors
2009-06-15T23:59:59.000Z
A novel technique for the real-time measurement of the magnetic field pitch angle in JET discharges using the motional Stark effect diagnostic is presented. Kalman filtering techniques are adopted to estimate the amplitude of the avalanche photodiode signals' harmonics that are relevant for the pitch angle calculation. The proposed technique {l_brace}for extended technical details of the generic algorithm see [R. Coelho and D. Alves, IEEE Trans. Plasma Sci. 37, 164 (2009)]{r_brace} is shown to be much more robust and provides less noisy estimates than an equivalent lock-in amplifier scheme, in particular when dealing with edge localized modes.
Javier Ortensi; Abderrafi M Ougouag
2009-07-01T23:59:59.000Z
The Doppler feedback mechanism is a major contributor to the passive safety of gas-cooled, graphite-moderated high temperature reactors that use fuel based on Tristructural-Isotropic coated particles. It follows that the correct prediction of the magnitude and time-dependence of this feedback effect is essential to the conduct of safety analyses for these reactors. We present a fuel conduction model for obtaining better estimates of the temperature feedback during moderate and fast transients. The fuel model has been incorporated in the CYNOD-THERMIX-KONVEK suite of coupled codes as a single TRISO particle within each calculation cell. The heat generation rate is scaled down from the neutronic solution and a Dirichlet boundary condition is imposed as the bulk graphite temperature from the thermal-hydraulic solution. This simplified approach yields similar results to those obtained with more complex methods, requiring multi-TRISO calculations within one control volume, but with much less computational effort. We provide an analysis of the hypothetical total control ejection event in the PBMR-400 design that clearly depicts the improvement in the predictions of the fuel temperature.
Conduction-Band-Offset Rule Governing J-V Distortion in CdS/CI(G)S Solar Cells
Sites, James R.
Conduction-Band-Offset Rule Governing J-V Distortion in CdS/CI(G)S Solar Cells A. Kanevce, MV at the n/p interface of a solar cell can lead to significant distortion of the current-voltage (J-V) curve-layer [TCO/CdS/CI(G)S] approximation for the solar cell. The parameters that influence the barrier height
.1063/1.4789855] The toxicity of Cd and the scarcity of Te, In, and Ga used in CdTe and Cu(In,Ga)S2 (CIGS) thin-film solar cellsEnhancing the efficiency of SnS solar cells via band-offset engineering with a zinc oxysulfideS is a promising earth-abundant material for photovoltaic applications. Heterojuction solar cells were made
Band offset between cubic GaN and AlN from intra- and interband spectroscopy of superlattices
Mietze, C.; Lischka, K.; As, D. J. [University of Paderborn, Faculty of Science, Department of Physics, Warburger Strasse 100 D-33098 Paderborn (Germany); DeCuir, E. A. Jr.; Manasreh, M. O. [Department of Electrical Engineering, University of Arkansas, 3217 Bell Engineering Center, Fayetteville, Arkansas 72701 (United States)
2010-11-01T23:59:59.000Z
By the analysis of intra- and intersubband transitions in GaN/AlN superlattices the band offset is determined experimentally. Superlattice structures with different period lengths were fabricated by plasma-assisted molecular beam epitaxy 3C-SiC substrates. The structural properties were studied by high resolution X-ray diffraction, revealing a high structural perfection of the superlattice region with several peaks in the X-ray spectra. Infrared absorbance spectroscopy revealed clear intrasubband transitions in the spectral region of 1.55 {mu}m measured at room temperature. Clear intersubband transitions were observed by photoluminescence at room temperature. These transition energies were compared to calculated energies using a 1D Poisson Schroedinger solver. For the calculations standard parameters for cubic GaN and AlN were used, while the band offset between GaN and AlN was varied. Optimal agreement between experimental and theoretical data was obtained for a band offset {Delta}E{sub C}:{Delta} E{sub V} of 55:45.
Acoustic And Elastic Reverse-Time Migration: Novel Angle-Domain Imaging Conditions And Applications
Yan, Rui
2013-01-01T23:59:59.000Z
synthetic offset vertical seismic profiles: Proceedings ofsynthetic offset vertical seismic profiles: Proceedings of
Tong, Xiao-Min; Chu, Shih-I
1998-01-01T23:59:59.000Z
We present a self-interaction-free time-dependent density-functional theory (TDDFT) for nonperturbative treatment of multiphoton processes of many-electron atomic systems in intense laser fields. The theory is based on the ...
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chang, Jingbo; Zhou, Guihua; Gao, Xianfeng; Mao, Shun; Cui, Shumao; Ocola, Leonidas E.; Yuan, Chris; Chen, Junhong
2015-08-01T23:59:59.000Z
Field-effect transistor (FET) sensors based on reduced graphene oxide (rGO) for detecting chemical species provide a number of distinct advantages, such as ultrasensitivity, label-free, and real-time response. However, without a passivation layer, channel materials directly exposed to an ionic solution could generate multiple signals from ionic conduction through the solution droplet, doping effect, and gating effect. Therefore, a method that provides a passivation layer on the surface of rGO without degrading device performance will significantly improve device sensitivity, in which the conductivity changes solely with the gating effect. In this work, we report rGO FET sensor devices with Hg2+-dependent DNAmore »as a probe and the use of an Al2O3 layer to separate analytes from conducting channel materials. The device shows good electronic stability, excellent lower detection limit (1 nM), and high sensitivity for real-time detection of Hg2+ in an underwater environment. Our work shows that optimization of an rGO FET structure can provide significant performance enhancement and profound fundamental understanding for the sensor mechanism.« less
Broader source: Energy.gov [DOE]
Fining Large Aperture Fractures in Geothermal Resource Areas Using A Three-Component Long-Offset Surface Seismic Survey, PSInSAR, and Kinematic Analysis presentation at the April 2013 peer review meeting held in Denver, Colorado.
Bernadett, Lauren
2013-01-01T23:59:59.000Z
pdf; Section 3: Emissions Trading/Offset Credits – A Market1, 2013. 19 Under the Emissions Trading Program , L EGAL Pand-ab-32s- emissions-trading-program/. Additionally,
Urquiza, Eugenio
2009-01-01T23:59:59.000Z
intermediate heat exchanger used high pressure helium not asexchanger performance: predictive model for heat transfer and pressurePressure Drop Correlations for the Rectangular Offset Strip Fin Compact Heat Exchanger. ”
Band offsets of TiZnSnO/Si heterojunction determined by x-ray photoelectron spectroscopy
Sun, R. J.; Jiang, Q. J.; Yan, W. C.; Feng, L. S.; Lu, B.; Ye, Z. Z. [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Li, X. F. [Key Laboratory of Advanced Display and System Application, Ministry of Education, Shanghai University, Shanghai 200072 (China); Li, X. D. [Xinyi PV Products (Anhui) Holdings LTD, Xinyi PV Glass Industrial Zone, No. 2 Xinyi Road, ETDZ, Wuhu 241009 (China); Lu, J. G., E-mail: lujianguo@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Key Laboratory of Advanced Display and System Application, Ministry of Education, Shanghai University, Shanghai 200072 (China)
2014-09-28T23:59:59.000Z
X-ray photoelectron spectroscopy (XPS) was utilized to measure the valence band offset (?E{sub V}) of the TiZnSnO (TZTO)/Si heterojunction. TZTO films were deposited on Si (100) substrates using magnetron sputtering at room temperature. By using the Zn 2p{sub 3/2} and Sn 3d{sub 5/2} energy levels as references, the value of ?E{sub V} was calculated to be 2.69 ± 0.1 eV. Combining with the experimental optical energy band gap of 3.98 eV for TZTO extracted from the UV-vis transmittance spectrum, the conduction band offset (?E{sub C}) was deduced to be 0.17 ± 0.1 eV at the interface. Hence, the energy band alignment of the heterojunction was determined accurately, showing a type-I form. This will be beneficial for the design and application of TZTO/Si hybrid devices.
Sari, Ilkay
2009-06-02T23:59:59.000Z
Every individual node in a network has its own clock. The clock consists of hardware and software parts. The hardware part includes an oscillator and a counter. The counter is incremented in accordance with the zero-crossings or the edges of the periodic... in time-synchronization protocols is a rather simple process, one node tells the other one its time in a controlled manner just like saying \\it?s ten past flve according to my clock". There are two main methods to exchange time-stamps. The flrst method...
LF411LowOffsetLowDriftJFETInputOperationalAmplifier February 1995
Wedeward, Kevin
10 k0 02% RLe10k VOe20 Vp-p BWe20 Hzb20 kHz Y Low 1 f noise corner 50 Hz Y Fast settling time to 0 01
Lindeman, Robert W.
the problem of wind field computation out of the scope of the paper. We instead, developed an editor for the developer to manually define a wind field given a virtual environment. Figure 1: The WindCube. Small a small pilot study asking the human subjects about one's feeling about the wind generated in number
2001-01-01T23:59:59.000Z
Real-Time Laser-Based Non-Intrusive Detection System forReal-Time Laser-Based Non-Intrusive Detection System foroptics. The laser-based non-intrusive detection system uses
Kowalsky, Michael B.; Finsterle, Stefan; Peterson, John; Hubbard,Susan; Rubin, Yoram; Majer, Ernest; Ward, Andy; Gee, Glendon
2005-05-05T23:59:59.000Z
A method is described for jointly using time-lapse multiple-offset cross-borehole ground-penetrating radar (GPR) travel time measurements and hydrological measurements to estimate field-scale soil hydraulic parameters and parameters of the petrophysical function, which relates soil porosity and water saturation to the effective dielectric constant. We build upon previous work to take advantage of a wide range of GPR data acquisition configurations and to accommodate uncertainty in the petrophysical function. Within the context of water injection experiments in the vadose zone, we test our inversion methodology with synthetic examples and apply it to field data. The synthetic examples show that while realistic errors in the petrophysical function cause substantial errors in the soil hydraulic parameter estimates,simultaneously estimating petrophysical parameters allows for these errors to be minimized. Additionally, we observe in some cases that inaccuracy in the GPR simulator causes systematic error in simulated travel times, making necessary the simultaneous estimation of a correction parameter. We also apply the method to a three-dimensional field setting using time-lapse GPR and neutron probe (NP) data sets collected during an infiltration experiment at the U.S. Department of Energy (DOE) Hanford site in Washington. We find that inclusion of GPR data in the inversion procedure allows for improved predictions of water content, compared to predictions made using NP data alone.
Electronic properties of InP (001)/HfO{sub 2} (001) interface: Band offsets and oxygen dependence
KC, Santosh; Dong, Hong; Longo, Roberto C.; Xiong, Ka [Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080 (United States); Wang, Weichao [Department of Electronics and Microelectronics and Tianjin Key Laboratory of Photo-Electronic Thin Film Device and Technology, Nankai University, Tianjin 300071 (China); Wallace, Robert M.; Cho, Kyeongjae, E-mail: kjcho@utdallas.edu [Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, Texas 75080 (United States); Department of Physics, The University of Texas at Dallas, Richardson, Texas 75080 (United States)
2014-01-14T23:59:59.000Z
Using ab-initio methods, atomic structures and electronic properties of InP (001)/HfO{sub 2} (001) interface are studied within the framework of density functional theory. We examine the InP/HfO{sub 2} model interface electronic structures under varying oxidation conditions. The effects of indium and phosphorous concentrations on interfacial bonding, defect states, band offsets, and the thermodynamic stability at the interface are also investigated. The origin of interfacial gap states in InP (001)/HfO{sub 2} (001) interface are proposed, mainly from the P-rich oxides, which is validated by our experimental work. This highlights the importance of surface passivation prior to high-? deposition based on the in situ spectroscopic results of atomic layer deposition of HfO{sub 2} on InP.
Bellur Ramaswamy, Ravi S.; Tortorelli, Daniel A. [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, 1206 W. Green Street, Urbana, IL 61801 (United States); Fried, Eliot [Department of Mechanical and Aerospace Engineering, Washington University, Campus Box 1185, St. Louis, MO 63130-4899 (United States); Jiao Xiangmin [Computational Science and Engineering Division, College of Computing, Georgia Institute of Technology, 801 Atlantic Drive, Atlanta, GA 30332 (United States)
2008-02-15T23:59:59.000Z
Advances in the understanding of martensitic transformations (diffusionless, solid-solid phase transformations) have been instrumental to the recent discovery of new low hysteresis alloys. However, some key fundamental issues must be better understood to design still better alloys. Restricting attention to antiplane shear, we use finite element analysis to model the shape-memory alloy microstructure within the Abeyaratne-Knowles continuum thermomechanical framework and use an interface kinetic relation of the kind proposed by Rosakis and Tsai. Geometric singularities and topological changes associated with microstructural evolution pose significant numerical challenges. We address such challenges with a recently developed front-tracking scheme called the face-offsetting method (FOM) to explicitly model phase interfaces. Initial results demonstrate the effectiveness of FOM in resolving needle-like twinned microstructures.
Tong, Xiao-Min; Chu, Shih-I
2000-02-01T23:59:59.000Z
We present a general time-dependent approach for efficient and accurate treatment of high-resolution spectrocopy and quantum dynamics. The procedure is applied to an ab initio time-dependent study of three-dimensional ...
Chu, Shih-I; Tong, Xiao-Min
2001-06-12T23:59:59.000Z
We present a detailed study of the multiphoton ionization and high-order harmonic generation (HHG) processes of rare-gas atoms (He, Ne, and Ar) in intense pulsed laser fields by means of a self-interaction-free time-dependent density...
John Ashmead
2010-05-05T23:59:59.000Z
Normally we quantize along the space dimensions but treat time classically. But from relativity we expect a high level of symmetry between time and space. What happens if we quantize time using the same rules we use to quantize space? To do this, we generalize the paths in the Feynman path integral to include paths that vary in time as well as in space. We use Morlet wavelet decomposition to ensure convergence and normalization of the path integrals. We derive the Schr\\"odinger equation in four dimensions from the short time limit of the path integral expression. We verify that we recover standard quantum theory in the non-relativistic, semi-classical, and long time limits. Quantum time is an experiment factory: most foundational experiments in quantum mechanics can be modified in a way that makes them tests of quantum time. We look at single and double slits in time, scattering by time-varying electric and magnetic fields, and the Aharonov-Bohm effect in time.
Weis, Arthur
-LEVEL VARIATION IN THE FIELD AND THE GREENHOUSE Denise M. Franke, Allan G. Ellis, Manisha Dharjwa, Melinda. Greenhouse experiments using other populations along the cline and conducted under different photoperiod
Rufenach, C.L.; Schaper, J. (NOAA Space Environmental Lab., Boulder, CO (United States)); McPherron, R.L. (Univ. of California, Los Angeles (United States))
1992-01-01T23:59:59.000Z
Vector magnetic fields at geosynchronous orbit were measured during 1980-1984 using the operational GOES 2, GOES 5, and GOES 6 spacecraft magnetometers. The authors corrected these spacecraft measurements for offsets due to spacecraft state and then used these field estimates to create a data base with 1-min resolution. Hourly quiet field values were calculated for these years from this data base using the ground-based geomagnetic index criteria AE < 120 nT and {vert bar}Dst{vert bar} < 20 nT. These quiet field components, rotated into dipole HVD coordinates, were approximated by the first two coefficients of a two-dimensional Fourier series in time of day and season. The quiet geosynchronous field components, to first order, are given by mean values of about 90 nT, {minus}60 nT, and 5 nT; and sinusoidal diurnal amplitudes of about 21 nT, 5 nT, and 5 nT, respectively, for H, V, and D where the spacecraft magnetometer was located near the geomagnetic meridian. The second harmonic diurnal amplitudes and the first and second harmonic seasonal amplitudes are typically of the order of a few nanoteslas or less except for the D component, which exhibits a larger seasonal variation. Furthermore, a one-dimensional Fourier series in time of day was used to study the quiet field dependence on solar wind dynamic pressure, P{sub d}, by indexing the measurements into five pressure ranges during 1980. These quiet H measurements, including the pressure dependence, are compared with a first-order field model superimposed with a tail current, resulting in magnetospheric currents (magnetopause and tail) in agreement with previous model values.
Introduction Classical Field Theory
Baer, Christian
Introduction Classical Field Theory Locally Covariant Quantum Field Theory Renormalization Time evolution Conclusions and outlook Locality and Algebraic Structures in Field Theory Klaus Fredenhagen IIÂ¨utsch and Pedro Lauridsen Ribeiro) Klaus Fredenhagen Locality and Algebraic Structures in Field Theory #12
Fleming, Paul D. "Dan"
SCREENING ON AN OFFSET PRESS Introduction: AM and FM screening take two totally different approaches"diffusiondither"arealsooftenusedtodescribethisprocess. This paper shows the on-press production of both AM and FM screened images,simultaneously,from the same plates and on the same press sheets. In addition, we show that FM, or stochasticallyscreenedimages
Kaspar, Tiffany C.; Droubay, Timothy C.
2012-07-01T23:59:59.000Z
Rational design and optimization of efficient photovoltaics requires fundamental knowledge of both the materials properties of the individual components and the conduction and valence band alignments at the materials interfaces. Efficient collection of electrons photogenerated in the absorber material requires a small or zero conduction band offset at both the absorber/n-type semiconductor and the n-type semiconductor/electrode interfaces. Negative conduction band offsets result in an energy barrier to electron injection, while large positive conduction band offsets (a “cliff” arrangement) result in too much energy lost during injection. However, it is difficult to predict heterojunction band offsets from bulk materials properties. Experimental band alignments of semiconductor heterojunctions rarely conform to the Anderson model,1 which assumes the band alignments are determined solely by differences in the electron affinity of the two semiconductors. Chemical bonds at the heterojunction interface give rise to an interfacial dipole which influences the interfacial band alignment. Thus, the complex interplay between electron affinity differences, Fermi level matching, interface-induced gap states, and band bending determine heterojunction band alignments.2-5 Band alignments can also be modified by doping, point defects, or control of non-stoichiometry at the interface; since these parameters can be affected by processing conditions, they offer a mechanism to modify the band alignments of a given heterojunction system.
Wysin, Gary
Physics II Exam 2 - Chs. 18A,19,20 - Electric Current, Magnetic Field Feb. 23, 2009 Name Rec. Instr-hours, the quantity 850 amp-hours must be a. power. b. energy. c. current. d. charge. b) (4) Give 850 amp-hours in SI
Wysin, Gary
the best answer. Questions about charges. 1. (2) T F Good conductors are materials that have a lot of free energy a. decreases. b. increases. c. does not change. Questions about electric fields. 9. (2) T F- leased from rest at point A and accelerates to point B by moving through the equipotentials shown
Yousef Ghazi-Tabatabai
2012-11-19T23:59:59.000Z
While Quantum Gravity remains elusive and Quantum Field Theory retains the interpretational difficulties of Quantum Mechanics, we have introduced an alternate approach to the unification of particles, fields, space and time, suggesting that the concept of matter as space without time provides a framework which unifies matter with spacetime and in which we anticipate the development of complete theories (ideally a single unified theory) describing observed 'particles, charges, fields and forces' solely with the geometry of our matter-space-time universe.
Unknown
2011-08-17T23:59:59.000Z
and Constraint Conditions ........................................... 20 2.3.2 Flexural Rigidity ........................................................................ 25 2.4 Vibration Analyses... and shear webs construction [4] ..................... 9 1.6 Architecture of computational blade model [11,30,31] ................................ 11 2.1 Boundary conditions for static analyses in the blade models ........................ 21 2.2 (a...
Li Lin; Qiu Jijun; Weng Binbin; Yuan Zijian; Shi Zhisheng [School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Li Xiaomin; Gan Xiaoyan [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Sellers, Ian R. [Deparment of Physics, University of Oklahoma, Norman, Oklahoma 73019 (United States)
2012-12-24T23:59:59.000Z
A heterojunction of PbSe/ZnO has been grown by molecular beam epitaxy. X-ray photoelectron spectroscopy was used to directly measure the valence-band offset (VBO) of the heterojunction. The VBO, {Delta}E{sub V}, was determined as 2.51 {+-} 0.05 eV using the Pb 4p{sup 3/2} and Zn 2p{sup 3/2} core levels as a reference. The conduction-band offset, {Delta}E{sub C}, was, therefore, determined to be 0.59 {+-} 0.05 eV based on the above {Delta}E{sub V} value. This analysis indicates that the PbSe/ZnO heterojunction forms a type I (Straddling Gap) heterostructure.
Goddard III, William A.
Predicted roles of defects on band offsets and energetics at CIGS (Cu(In,Ga)Se2/CdS) solar cell ZnO sputtering on the performance of Cu(In,Ga)Se2 thin film solar cells Appl. Phys. Lett. 105, 083906 alignment at the CdS Cu ( In , Ga ) S 2 interface in thin-film solar cells Appl. Phys. Lett. 86, 062109
Sub-20-Attosecond Timing Jitter Mode-Locked Fiber Lasers
Kim, Hyoji; Song, Youjian; Yang, Heewon; Shin, Junho; Kim, Chur; Jung, Kwangyun; Wang, Chingyue; Kim, Jungwon
2014-01-01T23:59:59.000Z
We demonstrate 14.3-attosecond timing jitter [integrated from 10 kHz to 94 MHz offset frequency] optical pulse trains from 188-MHz repetition-rate mode-locked Yb-fiber lasers. In order to minimize the timing jitter, we shorten the non-gain fiber length to shorten the pulsewidth and reduce excessive higher-order nonlinearity and nonlinear chirp in the fiber laser. The measured jitter spectrum is limited by the amplified spontaneous emission limited quantum noise in the 100 kHz - 1 MHz offset frequency range, while it was limited by the relative intensity noise-converted jitter in the lower offset frequency range. This intrinsically low timing jitter enables sub-100-attosecond synchronization between the two mode-locked Yb-fiber lasers over the full Nyquist frequency with a modest 10-kHz locking bandwidth. The demonstrated performance is the lowest timing jitter measured from any free-running mode-locked fiber lasers, comparable to the performance of the lowest-jitter Ti:sapphire solid-state lasers.
Washington Taylor
2006-06-28T23:59:59.000Z
This elementary introduction to string field theory highlights the features and the limitations of this approach to quantum gravity as it is currently understood. String field theory is a formulation of string theory as a field theory in space-time with an infinite number of massive fields. Although existing constructions of string field theory require expanding around a fixed choice of space-time background, the theory is in principle background-independent, in the sense that different backgrounds can be realized as different field configurations in the theory. String field theory is the only string formalism developed so far which, in principle, has the potential to systematically address questions involving multiple asymptotically distinct string backgrounds. Thus, although it is not yet well defined as a quantum theory, string field theory may eventually be helpful for understanding questions related to cosmology in string theory.
Noncommutative Two Time Physics
W. Chagas-Filho
2006-05-10T23:59:59.000Z
We present a classical formalism describing two-time physics with Abelian canonical gauge field backgrounds. The formalism can be used as a starting point for the construction of an interacting quantized two-time physics theory in a noncommutative soace-time.
De-Xing Kong; Kefeng Liu; Ming Shen
2008-08-30T23:59:59.000Z
In this letter we construct a new time-periodic solution of the vacuum Einstein's field equations whose Riemann curvature norm takes the infinity at some points. We show that this solution is intrinsically time-periodic and describes a time-periodic universe with the "black hole". New physical phenomena are investigated and new singularities are analyzed for this universal model.
Ernest A. Mancini; Joe Benson; David Hilton; David Cate; Lewis Brown
2006-05-29T23:59:59.000Z
The principal research efforts for Phase II of the project were drilling an infill well strategically located in Section 13, T. 10 N., R. 2 W., of the Womack Hill Field, Choctaw and Clarke Counties, Alabama, and obtaining fresh core from the upper Smackover reservoir to test the feasibility of implementing an immobilized enzyme technology project in this field. The Turner Land and Timber Company 13-10 No. 1 well was successfully drilled and tested at a daily rate of 132 barrels of oil in Section 13. The well has produced 27,720 barrels of oil, and is currently producing at a rate of 60 barrels of oil per day. The 13-10 well confirmed the presence of 175,000 barrels of attic (undrained) oil in Section 13. As predicted from reservoir characterization, modeling and simulation, the top of the Smackover reservoir in the 13-10 well is structurally high to the tops of the Smackover in offsetting wells, and the 13-10 well has significantly more net pay than the offsetting wells. The drilling and testing of the 13-10 well showed that the eastern part of the field continues to have a strong water drive and that there is no need to implement a pressure maintenance program in this part of the Womack Hill Field at this time. The success achieved in drilling and testing the 13-10 infill well demonstrates the benefits of building a geologic model to target areas in mature fields that have the potential to contain undrained oil, thus increasing the productivity and profitability of these fields. Microbial cultures that grew at 90 C and converted ethanol to acid were recovered from fresh cuttings from the Smackover carbonate reservoir in an analogous field to the Womack Hill Field in southwest Alabama; however, no viable microorganisms were found in the Smackover cores recovered from the drilling of the 13-10 well in Womack Hill Field. Further evaluation is, therefore, required prior to implementing an immobilized enzyme technology project in the Womack Hill Field.
Campiglia, Andres D. [UCF; Hernandez, Florencio E. [UCF
2014-08-28T23:59:59.000Z
The detrimental effects on human health caused by long-term exposure to trace contamination of toxic metals have been documented in numerous epidemiological and toxicological studies. The fact that metals are non-biodegradable and accumulate in the food chain poses a severe threat to the environment and human health. Their monitoring in drinking water, aquatic ecosystems, food and biological fluids samples is then essential for global sustainability. While research efforts employing established methodology continue to advance conceptual/computational models of contaminant behavior, the increasing awareness and public concern with environmental and occupational exposure to toxic metals calls for sensing devices capable to handle on-site elemental analysis in short analysis time. Field analysis with potable methodology prevents unnecessary scrutiny of un-contaminated samples via laboratory-bound methods, reduces analysis cost and expedites turnaround time for decision making and remediation purposes. Of particular toxicological interest are mercury and its species. Mercury is recognized as a major environmental pollution issue. The field-portable sensor developed in this project provides a unique and valuable tool for the on-site, real-time determination of inorganic mercury in surface waters. The ability to perform on-site analysis of mercury should prove useful in remote locations with difficult accessibility. It should facilitate data collection from statistically meaningful population sizes for a better understanding of the dose-effect role and the water-soil-plant-animal-human transfer mechanisms. The acquired knowledge should benefit the development of efficient environmental remediation processes, which is extremely relevant for a globally sustainable environment.
A Tile/Scenario Algorithm for Real-Time 3D Environments Vaibhav Govil and Ronald R. Mourant
properties: 1) offsets in X and Z from the tile's entry point to the tile's exit point, and 2) the angle between its entry point and exit point. We call this angle the tile's exit angle (EA). At load time, using is placed at X = 0, Z = 0 with zero rotation, since the entry road of all tiles was designed to point down
Shekhar, Ravi
2009-05-15T23:59:59.000Z
and amplitude variation with offset (AVO) results for our example model predicts that CO2 is easier to detect than brine in the fractured reservoirs. The effects of geochemical processes on seismics are simulated by time-lapse modeling for t = 1000 years. My...
van Kessel, Chris
Tillage and seasonal emissions of CO2, N2O and NO across a seed bed and at the field scale tillage may increase N2O emissions under certain circumstances, thereby offsetting C sequestration manage- ment accounted for almost 94% of total US N2O emissions from 1990 to 2004 (USEPA, 2006). In 2004
Duan, T. L.; Ang, D. S. [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore)] [School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore); Pan, J. S. [Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore)] [Institute of Materials Research and Engineering, A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore)
2013-05-20T23:59:59.000Z
The interface region between Ga-face n-type GaN and Al{sub 2}O{sub 3} dielectric (achieved via atomic-layer deposition or ALD) is investigated by X-ray photoelectron spectroscopy (XPS). An increase in the Ga-O to Ga-N bond intensity ratio following Al{sub 2}O{sub 3} deposition implies that the growth of an interfacial gallium sub-oxide (GaO{sub x}) layer occurred during the ALD process. This finding may be ascribed to GaN oxidation, which may still happen following the reduction of a thin native GaO{sub x} by trimethylaluminum (TMA) in the initial TMA-only cycles. The valence band offset between GaN and Al{sub 2}O{sub 3}, obtained using both core-level and valence band spectra, is found to vary with the thickness of the deposited Al{sub 2}O{sub 3}. This observation may be explained by an upward energy band bending at the GaN surface (due to the spontaneous polarization induced negative bound charge on the Ga-face GaN) and the intrinsic limitation of the XPS method for band offset determination.
Covariant Hamiltonian Field Theory
Jürgen Struckmeier; Andreas Redelbach
2012-05-22T23:59:59.000Z
A consistent, local coordinate formulation of covariant Hamiltonian field theory is presented. Whereas the covariant canonical field equations are equivalent to the Euler-Lagrange field equations, the covariant canonical transformation theory offers more general means for defining mappings that preserve the form of the field equations than the usual Lagrangian description. It is proved that Poisson brackets, Lagrange brackets, and canonical 2-forms exist that are invariant under canonical transformations of the fields. The technique to derive transformation rules for the fields from generating functions is demonstrated by means of various examples. In particular, it is shown that the infinitesimal canonical transformation furnishes the most general form of Noether's theorem. We furthermore specify the generating function of an infinitesimal space-time step that conforms to the field equations.
Guenter Nimtz
2009-01-26T23:59:59.000Z
How much time does a tunneling wave packet spent in traversing a barrier? Quantum mechanical calculations result in zero time inside a barrier . In the nineties analogous tunneling experiments with microwaves were carried out. The results agreed with quantum mechanical calculations. Electron tunneling time is hard to measure being extremely short and parasitic effects due to the electric charge of electrons may be dominant. However, quite recently the atomic ionization tunneling time has been measured. Experimental data of photonic, phononic, and electronic tunneling time is available now and will be presented. It appears that the tunneling time is a universal property independent of the field in question.
Léger, Emmanuel; Coquet, Yves
2013-01-01T23:59:59.000Z
In this study we show how to use GPR data acquired along the infiltration of water inside a single ring infiltrometer to inverse the saturated hydraulic conductivity. We used Hydrus-1D to simulate the water infiltration. We generated water content profiles at each time step of infiltration, based on a particular value of the saturated hydraulic conductivity, knowing the other van Genuchten parameters. Water content profiles were converted to dielectric permittivity profiles using the Complex Refractive Index Method relation. We then used the GprMax suite of programs to generate radargrams and to follow the wetting front using arrival time of electromagnetic waves recorded by a Ground-Penetrating Radar (GPR). Theoretically, the 1D time convolution between reflectivity and GPR signal at any infiltration time step is related to the peak of the reflected amplitude recorded in the corresponding trace in the radargram. We used this relation ship to invert the saturated hydraulic conductivity for constant and fallin...
Time-resolved x-ray scattering instrumentation
Borso, C.S.
1985-11-21T23:59:59.000Z
An apparatus and method for increased speed and efficiency of data compilation and analysis in real time is presented in this disclosure. Data is sensed and grouped in combinations in accordance with predetermined logic. The combinations are grouped so that a simplified reduced signal results, such as pairwise summing of data values having offsetting algebraic signs, thereby reducing the magnitude of the net pair sum. Bit storage requirements are reduced and speed of data compilation and analysis is increased by manipulation of shorter bit length data values, making real time evaluation possible.
Mitigated-force carriage for high magnetic field environments
Ludtka, Gerard M; Ludtka, Gail M; Wilgen, John B; Murphy, Bart L
2014-05-20T23:59:59.000Z
A carriage for high magnetic field environments includes a first work-piece holding means for holding a first work-piece, the first work-piece holding means being disposed in an operable relationship with a work-piece processing magnet having a magnetic field strength of at least 1 Tesla. The first work-piece holding means is further disposed in operable connection with a second work-piece holding means for holding a second work-piece so that, as the first work-piece is inserted into the magnetic field, the second work-piece is simultaneously withdrawn from the magnetic field, so that an attractive magnetic force imparted on the first work-piece offsets a resistive magnetic force imparted on the second work-piece.
Exposure guidelines for magnetic fields
Miller, G.
1987-12-01T23:59:59.000Z
The powerful magnetic fields produced by a controlled fusion experiment at Lawrence Livermore National Laboratory (LLNL) necessitated the development of personnel-exposure guidelines for steady magnetic fields. A literature search and conversations with active researchers showed that it is currently possible to develop preliminary exposure guidelines for steady magnetic fields. An overview of the results of past research into the bioeffects of magnetic fields was compiled, along with a discussion of hazards that may be encountered by people with sickle-cell anemia or medical electronic and prosthetic implants. The LLNL steady magnetic-field exposure guidelines along with a review of developments concerning the safety of time-varying fields were also presented in this compilation. Guidelines developed elsewhere for time varying fields were also given. Further research is needed to develop exposure standards for both steady or time-varying fields.
Determination of Band Offsets between the High-k Dielectric LaAlO3 Film and
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41clothThe Bonneville Power Administration wouldDecember 2014Field Campaign: Potential Application to ARMsearchSources
Blanchard, Peter K; Fong, Wen-fai
2015-01-01T23:59:59.000Z
[Abridged] We present the results of an extensive Hubble Space Telescope (HST) imaging study of ~100 Swift long-duration gamma-ray bursts (LGRBs) spanning 0.03 0.6 while bursts at R/R_h > 0.5 uniformly trace the light of their hosts. This indicates that the spatial correlation of LGRB locations with bright star forming regions seen in the full sample is dominated by the contribution from bursts at small offset and that LGRBs in the outer parts of galaxies show no preference for unusually bright star forming regions. We conclude that LGRBs strongly prefer the bright, inner regions of their hosts indicating that the star formation taking place there is more favorable for LGRB progenitor production. This indicates that another environmental factor beyond metallicity, such as binary interactions or IMF differences, may be operating in the central regions of LGRB hosts.
Irreducibility of the set of field operators in Noncommutative Quantum Field Theory
M. N. Mnatsakanova; Yu. S. Vernov
2012-09-02T23:59:59.000Z
Irreducibility of the set of quantum field operators has been proved in noncommutative quantum field theory in the general case when time does not commute with spatial variables.
Fleming, Paul D. "Dan"
Process Color Profiling: Syncing a Digital Press with an Offset Press Laura Kraft, Kate Blout, Michigan Abstract For both printers and clients, accurate proofs are needed before going to press. The proof should predict what the job would look like on the press. Press proofing is an integral part
The Electromagnetic Field as a Synchrony Gauge Field
Bock, Robert D
2015-01-01T23:59:59.000Z
Building on our previous work, we investigate the identification of the electromagnetic field as a local gauge field of a restricted group of synchrony transformations. We begin by arguing that the inability to measure the one-way speed of light independent of a synchronization scheme necessitates that physical laws must be reformulated without distant simultaneity. As a result, we are forced to introduce a new operational definition of time which leads to a fundamental space-time invariance principle that is related to a subset of the synchrony group. We identify the gauge field associated with this new invariance principle with the electromagnetic field. Consequently, the electromagnetic field acquires a space-time interpretation, as suggested in our previous work. In addition, we investigate the static, spherically symmetric solution of the resulting field equations. Also, we discuss implications of the present work for understanding the tension between classical and quantum theory.
Wayne Pennington; Mohamed Ibrahim; Roger Turpening; Sean Trisch; Josh Richardson; Carol Asiala; Walid Mabrouk
2008-09-30T23:59:59.000Z
Crosswell seismic surveys were conducted at two fields in northern Michigan. One of these, Springdale, included two monitor wells that are located external to the reef, and the other, Coldspring, employed two production wells within the reef. The Springdale wells extended to much greater depths than the reef, and imaging was conducted from above and from beneath the reef. The resulting seismic images provide the best views of pinnacle Niagaran reefs obtained to date. The tops of the reservoirs can be clearly distinguished, and their lateral extent or dipping edges can be observed along the profile. Reflecting events internal to the reef are evident; some of them are fairly continuous across the reef and others are discontinuous. Inversion of the seismic data indicates which events represent zones of higher porosity and which are lower porosity or even anhydrite plugged. The full stacked image includes angles that are beyond critical for many of the interfaces, and some reflections are visible only for a small range of angles, presumably near their critical angle. Stacking these angles in provides an opportunity for these events to be seen on the stacked image, where otherwise they would have been unrecognized. For inversion, however, the complexity associated with phase changes beyond critical can lead to poor results, and elastic inversion of partial angle stacks may be best conducted with restrictions to angles less than critical. Strong apparent attenuation of signals occurs when seismic ray paths pass through the upper part of the Springdale reservoir; this may be due to intrinsic attenuation and/or scattering of events due to the locally strongly varying gas saturation and extremely low fluid pressures. Signal-to-noise limitations become evident far from the source well in the Coldspring study, probably because the raw data were strongly affected by tube-wave noise generated by flow through the perforation of the receiver well. The seismic images obtained, and interpretations of them, as assisted by Amplitude-versus-Angle studies and accompanying inversion, provide additional insight into the internal geometry of these two reefs and provide data that should be useful for reservoir management.
The Ness field: An integrated field study
Karasek, R.M.; Kean, K.R.; Richards, M.L. (Mobil North Sea Ltd., London (England))
1990-05-01T23:59:59.000Z
The Ness oil field, located in UK Block 9/13, was discovered in May 1986 by well 9/13b-28A. The field comprises a high-quality Middle Jurassic reservoir with an average 148-ft oil column trapped in a west-dipping, fault-bounded closure. The oil is substantially undersaturated. The field was brought on production as a subsea satellite development tied back to the Beryl B Platform. Oil was first delivered on August 11, 1987, just over a year from discovery. Initial producing rates from the 9/13B-28A well averaged about 10,000 BOPD. Since this well, another producer and water injector have been completed. Based on the frequent and accurate pressure data available from permanent downhole gauges installed in all three wells of the Ness field, material balance was used to calculate initial oil in place. These calculations gave an oil in place value consistent with recent calculations of 87 {times} 166 STB after less than 3% of the oil-in-place had been produced, compared with 55 {times} 106 STB initially mapped. Pressure monitoring enabled reservoir drive mechanisms to be tracked and a high offtake rate to be maintained by balancing water injection with withdrawals. A reevaluation of the mapped structure was prompted by a revision of the geological model following the 9/13b-38/38Z appraisal wells, together with the discrepancy between the oil in place from mapping and material balance. The seismic data was reinterpreted using the additional well control, and the field remapped. This resulted in a revised volume of 129 {times} 106 STB. Additional insight into the differentiation between oil and water volumes in this low compressibility system and a resolution of the differences between material balance and volumetrics were obtained through a black-oil simulation.
Burra G. Sidharth
2008-09-03T23:59:59.000Z
We briefly review two concepts of time - the usual time associated with "being" and more recent ideas, answering to the description of "becoming". The approximation involved in the former is examined. Finally we argue that it is (unpredictable) fluctuations that underlie time.
M. Heller; W. Sasin
1997-11-17T23:59:59.000Z
In the groupoid approach to noncommutative quantization of gravity, gravitational field is quantized in terms of a C*-algebra A of complex valued funcions on a groupoid G (with convolution as multiplication). In the noncommutative quantum gravitational regime the concepts of space and time are meaningless. We study the "emergence of time" in the transition process from the noncommutative regime to the standard space-time geometry. Precise conditions are specified under which modular groups of the von Neumann algebra generated by A can be defined. These groups are interpreted as a state depending time flow. If the above conditions are further refined one obtains a state independent time flow. We show that quantum gravitational dynamics can be expressed in terms of modular groups.
Kwak, Seung Ki
2012-01-01T23:59:59.000Z
The existence of momentum and winding modes of closed string on a torus leads to a natural idea that the field theoretical approach of string theory should involve winding type coordinates as well as the usual space-time ...
Field ionization from carbon nanofibers
Adeoti, Bosun J
2008-01-01T23:59:59.000Z
The Micro Gas Analyzer project aims to develop power-efficient, high resolution, high sensitivity, portable and real-time gas sensors. We developed a field ionizer array based on gated CNTs. Arrays of CNTs are used because ...
Noncommutative Quantum Field Theories
H. O. Girotti
2003-03-19T23:59:59.000Z
We start by reviewing the formulation of noncommutative quantum mechanics as a constrained system. Then, we address to the problem of field theories defined on a noncommutative space-time manifold. The Moyal product is introduced and the appearance of the UV/IR mechanism is exemplified. The emphasis is on finding and analyzing noncommutative quantum field theories which are renormalizable and free of nonintegrable infrared singularities. In this last connection we give a detailed discussion of the quantization of the noncommutative Wess-Zumino model as well as of its low energy behavior.
Kinsy, Michel A.
This paper details the design and application of a new ultra-high speed real-time simulation for Hardware-in-the-Loop (HiL) testing and design of high-power power electronics systems. Our real-time hardware emulation for ...
Abreu, Gabriel
2010-01-01T23:59:59.000Z
In a general time-dependent (3+1)-dimensional spherically symmetric spacetime, the so-called Kodama vector is a naturally defined geometric quantity that is timelike outside the evolving horizon and so defines a preferred class of fiducial observers. However the Kodama vector does not by itself define any preferred notion of time. We demonstrate that a preferred time coordinate - which we shall call Kodama time - can be introduced by taking the additional step of applying the Clebsch decomposition theorem to the Kodama vector. We thus construct a geometrically preferred coordinate system for any time-dependent spherically symmetric spacetime, and explore its properties. In particular we use this formalism to construct a general class of conservation laws, generalizing Kodama's energy flux. We study the geometrically preferred fiducial observers, and demonstrate that it is possible to define and calculate a generalized notion of surface gravity that is valid throughout the entire evolving spacetime. Furthermor...
Irreducibility of the set of field operators in NC QFT
Mnatsakanova, M. N., E-mail: mnatsak@theory.sinp.msu.ru [Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Vernov, Yu. S. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)] [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)
2013-10-15T23:59:59.000Z
Irreducibility of the set of quantum field operators has been proved in noncommutative quantum field theory in the general case when time does not commute with spatial variables.
Smooth Field Theories and Homotopy Field Theories
Wilder, Alan Cameron
2011-01-01T23:59:59.000Z
1 . . . . . . . . 4 Categories of Field Theories 4.1 Functorto super symmetric field theories. CRM Proceedings and0-dimensional super symmetric field theories. preprint 2008.
Carrera, Juan J.; Chu, Shih-I; Tong, Xiao-Min
2005-06-21T23:59:59.000Z
We present an ab initio nonpertubative investigation of the mechanisms responsible for the production of very-high-order harmonic generation (HHG) from Ar atoms and Ar+ ions by means of the self-interaction-free time-dependent density...
Chu, Shih-I; Telnov, Dmitry A.
2009-04-03T23:59:59.000Z
We present a time-dependent density-functional-theory approach for the ab initio study of the effect of correlated multielectron responses on the multiphoton ionization (MPI) of diatomic molecules N2, O2, and F2 in intense ...
Giovannetti, Vittorio
We give a consistent quantum description of time, based on Page and Wootters’s conditional probabilities mechanism, which overcomes the criticisms that were raised against similar previous proposals. In particular we show ...
Unknown
2011-09-05T23:59:59.000Z
-1 THE PREDICTION OF BUS ARRIVAL TIME USING AUTOMATIC VEHICLE LOCATION SYSTEMS DATA A Dissertation by RAN HEE JEONG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of DOCTOR OF PHILOSOPHY December 2004 Major Subject: Civil Engineering THE PREDICTION OF BUS ARRIVAL TIME USING AUTOMATIC VEHICLE LOCATION SYSTEMS DATA A Dissertation by RAN HEE JEONG Submitted to Texas A...
E. Minguzzi
2009-09-04T23:59:59.000Z
Every time function on spacetime gives a (continuous) total preordering of the spacetime events which respects the notion of causal precedence. The problem of the existence of a (semi-)time function on spacetime and the problem of recovering the causal structure starting from the set of time functions are studied. It is pointed out that these problems have an analog in the field of microeconomics known as utility theory. In a chronological spacetime the semi-time functions correspond to the utilities for the chronological relation, while in a K-causal (stably causal) spacetime the time functions correspond to the utilities for the K^+ relation (Seifert's relation). By exploiting this analogy, we are able to import some mathematical results, most notably Peleg's and Levin's theorems, to the spacetime framework. As a consequence, we prove that a K-causal (i.e. stably causal) spacetime admits a time function and that the time or temporal functions can be used to recover the K^+ (or Seifert) relation which indeed turns out to be the intersection of the time or temporal orderings. This result tells us in which circumstances it is possible to recover the chronological or causal relation starting from the set of time or temporal functions allowed by the spacetime. Moreover, it is proved that a chronological spacetime in which the closure of the causal relation is transitive (for instance a reflective spacetime) admits a semi-time function. Along the way a new proof avoiding smoothing techniques is given that the existence of a time function implies stable causality, and a new short proof of the equivalence between K-causality and stable causality is given which takes advantage of Levin's theorem and smoothing techniques.
The WSRT wide-field HI survey: I. The background galaxy sample
Robert Braun; David Thilker; Rene Walterbos
2003-05-21T23:59:59.000Z
We have used the Westerbork array to carry out an unbiased wide-field survey for HI emission features, achieving an RMS sensitivity of about 18 mJy/Beam at a velocity resolution of 17 km/s over 1800 deg^2 and between -1000 < V_Hel<+6500 km/s. The primary data consists of auto-correlation spectra with an effective angular resolution of 49' FWHM. We detect 155 external galaxies in excess of 8 sigma in integrated HI flux density. Plausible optical associations are found within a 30' search radius for all but one of our HI detections in DSS images, although several are not previously cataloged or do not have published red-shift determinations. Twenty-three of our objects are detected in HI for the first time. We classify almost half of our detections as ``confused'', since one or more companions is cataloged within a radius of 30' and a velocity interval of 400 km/s. We identify a handful of instances of significant positional offsets exceeding 10 kpc of unconfused optical galaxies with the associated HI centroid, possibly indicative of severe tidal distortions or uncataloged gas-rich companions. A possible trend is found for an excess of detected HI flux in unconfused galaxies within our large survey beam relative to that detected previously in smaller telescope beams, both as function of increasing distance and increasing gas mass. This may be an indication for a diffuse gaseous component on 100 kpc scales in the environment of massive galaxies or a population of uncataloged low mass companions. We use our galaxy sample to estimate the HI mass function from our survey volume. Good agreement is found with the HIPASS BGC results, but only after explicit correction for galaxy density variations with distance.
Elliott, C.J.; McVey, B. (Los Alamos National Lab., NM (USA)); Quimby, D.C. (Spectra Technology, Inc., Bellevue, WA (USA))
1990-01-01T23:59:59.000Z
The level of field errors in an FEL is an important determinant of its performance. We have computed 3D performance of a large laser subsystem subjected to field errors of various types. These calculations have been guided by simple models such as SWOOP. The technique of choice is utilization of the FELEX free electron laser code that now possesses extensive engineering capabilities. Modeling includes the ability to establish tolerances of various types: fast and slow scale field bowing, field error level, beam position monitor error level, gap errors, defocusing errors, energy slew, displacement and pointing errors. Many effects of these errors on relative gain and relative power extraction are displayed and are the essential elements of determining an error budget. The random errors also depend on the particular random number seed used in the calculation. The simultaneous display of the performance versus error level of cases with multiple seeds illustrates the variations attributable to stochasticity of this model. All these errors are evaluated numerically for comprehensive engineering of the system. In particular, gap errors are found to place requirements beyond mechanical tolerances of {plus minus}25{mu}m, and amelioration of these may occur by a procedure utilizing direct measurement of the magnetic fields at assembly time. 4 refs., 12 figs.
Quantum Field and Cosmic Field-Finite Geometrical Field Theory of Matter Motion Part Three
Jianhua Xiao
2005-12-20T23:59:59.000Z
This research establishes an operational measurement way to express the quantum field theory in a geometrical form. In four-dimensional spacetime continuum, the orthogonal rotation is defined. It forms two sets of equations: one set is geometrical equations, another set is the motion equations. The Lorentz transformation can be directly derived from the geometrical equations, and the proper time of general relativity is well expressed by time displacement field. By the motion equations, the typical time displacement field of matter motion is discussed. The research shows that the quantum field theory can be established based on the concept of orthogonal rotation. On this sense, the quantum matter motion in physics is viewed as the orthogonal rotation of spacetime continuum. In this paper, it shows that there are three typical quantum solutions. One is particle-like solution, one is generation-type solution, and one is pure wave type solution. For each typical solution, the force fields are different. Many features of quantum field can be well explained by this theoretic form. Finally, the general matter motion is discussed, the main conclusions are: (1). Geometrically, cosmic vacuum field can be described by the curvature spacetime; (2). The spatial deformation of planet is related with a planet electromagnetic field; (3). For electric charge less matter, the volume of matter will be expanding infinitely; (4).For strong electric charge matter, it shows that the volume of matter will be contracting infinitely.
Tular Lake Field, Kings County, California - a significant onshore development
Lindblom, R.G.; Waldron, J.M.
1985-04-01T23:59:59.000Z
The Tulare Lake field is located in Kings County, California, on the west side of the San Joaquin Valley and 10 mi east of the Kettleman Hills (North Dome) field and 30 mi souuheast of the city of Coalinga. The field was discovered by Husky Oil Co. (Marathon) in October 1981 with the completion of the Boswell 22-16, Sec. 16, T22S, R20E from sands in the Burbank formation of Oligocene geologic age. Chevron USA offset the Husky discovery well with the completion of the Salyer 678X, Sec. 8, T22S, R20E, in May 1983. Both Chevron and Husky have continued an orderly development of the field, and to date Chevron has 9 producing wells and Husky 10 producing wells. Production is found in the Burbank formation at a vertical depth below 12,800 ft. The entrapment of hydrocarbons is caused by a low amplitude, seismically subtle, anticlinal fold trending northwest/southeast. Isochore maps of the Burbank formation show that stratigraphy is important in the distribution of the four producing sand intervals. Oil gravities form the sands vary 39/sup 0/ API to 51/sup 0/ API and the GOR ranges from 1050 to over 5500. As of January 1, 1984, the field has a cumulative production of 1.7 million bbl of oil and 3.5 billion ft/sup 3/ of gas.
Near-field single molecule spectroscopy
Xie, X.S.; Dunn, R.C.
1995-02-01T23:59:59.000Z
The high spatial resolution and sensitivity of near-field fluorescence microscopy allows one to study spectroscopic and dynamical properties of individual molecules at room temperature. Time-resolved experiments which probe the dynamical behavior of single molecules are discussed. Ground rules for applying near-field spectroscopy and the effect of the aluminum coated near-field probe on spectroscopic measurements are presented.
A. Steffens; C. A. Riofrío; R. Hübener; J. Eisert
2014-11-06T23:59:59.000Z
We introduce the concept of quantum field tomography, the efficient and reliable reconstruction of unknown quantum fields based on data of correlation functions. At the basis of the analysis is the concept of continuous matrix product states, a complete set of variational states grasping states in quantum field theory. We innovate a practical method, making use of and developing tools in estimation theory used in the context of compressed sensing such as Prony methods and matrix pencils, allowing us to faithfully reconstruct quantum field states based on low-order correlation functions. In the absence of a phase reference, we highlight how specific higher order correlation functions can still be predicted. We exemplify the functioning of the approach by reconstructing randomised continuous matrix product states from their correlation data and study the robustness of the reconstruction for different noise models. We also apply the method to data generated by simulations based on continuous matrix product states and using the time-dependent variational principle. The presented approach is expected to open up a new window into experimentally studying continuous quantum systems, such as encountered in experiments with ultra-cold atoms on top of atom chips. By virtue of the analogy with the input-output formalism in quantum optics, it also allows for studying open quantum systems.
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirtA Journey InsideMicroBooNE LArTPC Sarah Lockwitz, FNAL 2013 DPFTheses 2014No.7 D I STime Off Time Off A
Smooth Field Theories and Homotopy Field Theories
Wilder, Alan Cameron
2011-01-01T23:59:59.000Z
CHAPTER 3. FIELD THEORIES Definition 3.2.1. A smooth fielda ’top down’ definition of field theories. Taking as ourin the following. Definition A field theory is a symmetric
Graphene field emission devices
Kumar, S., E-mail: shishirk@gmail.com; Raghavan, S. [Centre for Nanoscience and Engineering, Indian Institute of Science, Bengaluru (India); Duesberg, G. S. [Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and School of Chemistry, Trinity College Dublin, Dublin, D2 (Ireland); Pratap, R. [Centre for Nanoscience and Engineering, Indian Institute of Science, Bengaluru (India); Department of Mechanical Engineering, Indian Institute of Science, Bengaluru (India)
2014-09-08T23:59:59.000Z
Graphene field emission devices are fabricated using a scalable process. The field enhancement factors, determined from the Fowler-Nordheim plots, are within few hundreds and match the theoretical predictions. The devices show high emission current density of ?10?nA ?m{sup ?1} at modest voltages of tens of volts. The emission is stable with time and repeatable over long term, whereas the noise in the emission current is comparable to that from individual carbon nanotubes emitting under similar conditions. We demonstrate a power law dependence of emission current on pressure which can be utilized for sensing. The excellent characteristics and relative ease of making the devices promise their great potential for sensing and electronic applications.
Mathematical quantization of Hamiltonian field theories
A. V. Stoyanovsky
2015-02-04T23:59:59.000Z
We define the renormalized evolution operator of the Schr\\"odinger equation in the infinite dimensional Weyl-Moyal algebra during a time interval for a wide class of Hamiltonians depending on time. This leads to a mathematical definition of quantum field theory $S$-matrix and Green functions. We show that for renormalizable field theories, our theory yields the renormalized perturbation series of perturbative quantum field theory. All the results are based on the Feynman graph series technique.
Timing analysis of PWR fuel pin failures
Jones, K.R.; Wade, N.L.; Katsma, K.R.; Siefken, L.J. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Straka, M. (Halliburton NUS, Idaho Falls, ID (United States))
1992-09-01T23:59:59.000Z
This report discusses research conducted to develop and demonstrate a methodology for calculation of the time interval between receipt of the containment isolation signals and the first fuel pin failure for loss-of-coolant accidents (LOCAs). Demonstration calculations were performed for a Babcock and Wilcox (B W) design (Oconee) and a Westinghouse (W) four-loop design (Seabrook). Sensitivity studies were performed to assess the impacts of fuel pin burnup, axial peaking factor, break size, emergency core cooling system availability, and main coolant pump trip on these times. The analysis was performed using the following codes: FRAPCON-2, for the calculation of steady-state fuel behavior; SCDAP/RELAP5/MOD3 and TRACPF1/MOD1, for the calculation of the transient thermal-hydraulic conditions in the reactor system; and FRAP-T6, for the calculation of transient fuel behavior. In addition to the calculation of fuel pin failure timing, this analysis provides a comparison of the predicted results of SCDAP/RELAP5/MOD3 and TRAC-PF1/MOD1 for large-break LOCA analysis. Using SCDAP/RELAP5/MOD3 thermal-hydraulic data, the shortest time intervals calculated between initiation of containment isolation and fuel pin failure are 10.4 seconds and 19.1 seconds for the B W and W plants, respectively. Using data generated by TRAC-PF1/MOD1, the shortest intervals are 10.3 seconds and 29.1 seconds for the B W and W plants, respectively. These intervals are for a double-ended, offset-shear, cold leg break, using the technical specification maximum peaking factor and applied to fuel with maximum design burnup. Using peaking factors commensurate with actual burnups would result in longer intervals for both reactor designs. This document provides appendices K and L of this report which provide plots for the timing analysis of PWR fuel pin failures for Oconee and Seabrook respectively.
Negative Energies and Field Theory
Gerald E. Marsh
2008-11-20T23:59:59.000Z
The assumption that the vacuum is the minimum energy state, invariant under unitary transformations, is fundamental to quantum field theory. However, the assertion that the conservation of charge implies that the equal time commutator of the charge density and its time derivative vanish for two spatially separated points is inconsistent with the requirement that the vacuum be the lowest energy state. Yet, for quantum field theory to be gauge invariant, this commutator must vanish. This essay explores how this conundrum is resolved in quantum electrodynamics.
Daiqin Su; T. C. Ralph
2015-07-02T23:59:59.000Z
We show that the particle number distribution of diamond modes, modes that are localised in a finite space-time region, are thermal for the Minkowski vacuum state of a massless scalar field, an analogue to the Unruh effect. The temperature of the diamond is inversely proportional to its size. An inertial observer can detect this thermal radiation by coupling to the diamond modes using an appropriate energy scaled detector. We further investigate the correlations between various diamonds and find that entanglement between adjacent diamonds dominates.
Thermo--hydrodynamics As a Field Theory
Jacek Jezierski; Jerzy Kijowski
2011-12-26T23:59:59.000Z
The field theoretical description of thermo-hydrodynamics is given. It is based on the duality between the physical space--time and the "material space-time" which we construct here. The material space appearing in a natural way in the canonical formulation of the hydrodynamics is completed with a material time playing role of the field potential for temperature. Both Lagrangian and Hamiltonian formulations, the canonical structure, Poisson bracket, N\\"other theorem and conservation laws are discussed.
Dispatch R427 Time perception: Brain time or event time?
Johnston, Alan
Dispatch R427 Time perception: Brain time or event time? Alan Johnston* and Shin'ya Nishida Recent experiments show that synchronous events can appear to an observer to occur at different times. Neural processing time delays are offered as an explanation of these temporal illusions, but equating perceived time
Timing analysis of PWR fuel pin failures
Jones, K.R.; Wade, N.L.; Katsma, K.R.; Siefken, L.J. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Straka, M. (Halliburton NUS, Idaho Falls, ID (United States))
1992-09-01T23:59:59.000Z
Research has been conducted to develop and demonstrate a methodology for calculation of the time interval between receipt of the containment isolation signals and the first fuel pin failure for loss-of-coolant accidents (LOCAs). Demonstration calculations were performed for a Babcock and Wilcox (B W) design (Oconee) and a Westinghouse (W) four-loop design (Seabrook). Sensitivity studies were performed to assess the impacts of fuel pin bumup, axial peaking factor, break size, emergency core cooling system availability, and main coolant pump trip on these times. The analysis was performed using the following codes: FRAPCON-2, for the calculation of steady-state fuel behavior; SCDAP/RELAP5/MOD3 and TRACPF1/MOD1, for the calculation of the transient thermal-hydraulic conditions in the reactor system; and FRAP-T6, for the calculation of transient fuel behavior. In addition to the calculation of fuel pin failure timing, this analysis provides a comparison of the predicted results of SCDAP/RELAP5/MOD3 and TRAC-PFL/MOD1 for large-break LOCA analysis. Using SCDAP/RELAP5/MOD3 thermal-hydraulic data, the shortest time intervals calculated between initiation of containment isolation and fuel pin failure are 10.4 seconds and 19.1 seconds for the B W and W plants, respectively. Using data generated by TRAC-PF1/MOD1, the shortest intervals are 10.3 seconds and 29.1 seconds for the B W and W plants, respectively. These intervals are for a double-ended, offset-shear, cold leg break, using the technical specification maximum peaking factor and applied to fuel with maximum design bumup. Using peaking factors commensurate widi actual bumups would result in longer intervals for both reactor designs. This document also contains appendices A through J of this report.
Time Management Managing Time and Tasks
Kunkle, Tom
Time Management Managing Time and Tasks What is time management? Time can't be managed Â but you can manage the amount of time you use each day for fun, work, rest, and time spent with others. Why is time management important? You have responsibilities to yourself, to your family and friends, to your
Internal split field generator
Thundat; Thomas George (Knoxville, TN); Van Neste, Charles W. (Kingston, TN); Vass, Arpad Alexander (Oak Ridge, TN)
2012-01-03T23:59:59.000Z
A generator includes a coil of conductive material. A stationary magnetic field source applies a stationary magnetic field to the coil. An internal magnetic field source is disposed within a cavity of the coil to apply a moving magnetic field to the coil. The stationary magnetic field interacts with the moving magnetic field to generate an electrical energy in the coil.
Eddy-current-induced multipole field calculations.
Sereno, N. S.; Kim, S. H.
2003-10-15T23:59:59.000Z
Time-varying magnetic fields of magnets in booster accelerators induce substantial eddy currents in the vacuum chambers. The eddy currents in turn act to produce various multipole fields that act on the beam. These fields must be taken into account when doing a lattice design. In the APS booster, the relatively long dipole magnets (3 meters) are linearly ramped to accelerate the injected 325 MeV beam to 7 GeV. Substantial dipole and sextupole fields are generated in the elliptical vacuum chamber from the induced eddy currents. In this note, formulas for the induced dipole and sextupole fields are derived for elliptical and rectangular vacuum chambers for a time-varying dipole field. A discussion is given on how to generalize this derivation method to include eddy-current-induced multipole fields from higher multipole magnets (quadrupole, sextupole, etc.). Finally, transient effects are considered.
Mark, J. Abraham Hudson, E-mail: a.john.peter@gmail.com; Peter, A. John, E-mail: a.john.peter@gmail.com [Dept. of Physics, SSM Institute of Engineering and Technology, Dindigul-624002 (India)
2014-04-24T23:59:59.000Z
Third order susceptibility of third order harmonic generation is investigated in a Zn{sub 0.1}Mg{sub 0.9}Se/Zn{sub 0.8}Mg{sub 0.2}Se/Zn{sub 0.1}Mg{sub 0.9}Se quantum well in the presence of magnetic field strength. The confinement potential is considered as the addition of energy offsets of the conduction band (or valence band) and the strain-induced potential in our calculations. The material dependent effective mass is followed throughout the computation because it has a high influence on the electron energy levels in low dimensional semiconductor systems.
Linear electric field mass spectrometry
McComas, D.J.; Nordholt, J.E.
1992-12-01T23:59:59.000Z
A mass spectrometer and methods for mass spectrometry are described. The apparatus is compact and of low weight and has a low power requirement, making it suitable for use on a space satellite and as a portable detector for the presence of substances. High mass resolution measurements are made by timing ions moving through a gridless cylindrically symmetric linear electric field. 8 figs.
Quantum Field Theory Mark Srednicki
Akhmedov, Azer
The Spin-Statistics Theorem (3) 45 5 The LSZ Reduction Formula (3) 49 6 Path Integrals in Quantum Mechanics Quantization of Spinor Fields II (38) 246 40 Parity, Time Reversal, and Charge Conjugation (23, 39) 254 #12, 59) 369 #12;6 63 The Vertex Function in Spinor Electrodynamics (62) 378 64 The Magnetic Moment
Applicability of post-ionization theory to laser-assisted field evaporation of magnetite
Schreiber, Daniel K.; Chiaramonti, Ann N.; Gordon, Lyle M.; Kruska, Karen
2014-12-15T23:59:59.000Z
Analysis of the mean Fe ion charge state from laser-assisted field evaporation of magnetite (Fe3O4) reveals unexpected trends as a function of laser pulse energy that break from conventional post-ionization theory for metals. For Fe ions evaporated from magnetite, the effects of post-ionization are partially offset by the increased prevalence of direct evaporation into higher charge states with increasing laser pulse energy. Therefore the final charge state is related to both the field strength and the laser pulse energy, despite those variables themselves being intertwined when analyzing at a constant detection rate. Comparison of data collected at different base temperatures also show that the increased prevalence of Fe2+ at higher laser energies is possibly not a direct thermal effect. Conversely, the ratio of 16O+:16O2+ is well-correlated with field strength and unaffected by laser pulse energy on its own, making it a better overall indicator of the field evaporation conditions than the mean Fe charge state. Plotting the normalized field strength versus laser pulse energy also elucidates a non-linear dependence, in agreement with previous observations on semiconductors, that suggests a field-dependent laser absorption efficiency. Together these observations demonstrate that the field evaporation process for laser-pulsed oxides exhibits fundamental differences from metallic specimens that cannot be completely explained by post-ionization theory. Further theoretical studies, combined with detailed analytical observations, are required to understand fully the field evaporation process of non-metallic samples.
Time parallel gravitational collapse simulation
Kreienbuehl, Andreas; Ruprecht, Daniel; Krause, Rolf
2015-01-01T23:59:59.000Z
This article demonstrates the applicability of the parallel-in-time method Parareal to the numerical solution of the Einstein gravity equations for the spherical collapse of a massless scalar field. To account for the shrinking of the spatial domain in time, a tailored load balancing scheme is proposed and compared to load balancing based on number of time steps alone. The performance of Parareal is studied for both the sub-critical and black hole case; our experiments show that Parareal generates substantial speedup and, in the super-critical regime, can also reproduce the black hole mass scaling law.
Quantum gravity, the origin of time and time's arrow
Moffat, J.W. (Univ. of Toronto, Ontario (Canada))
1993-03-01T23:59:59.000Z
The local Lorentz and diffeomorphism symmetries of Einstein's gravitational theory are spontaneously broken by a Higgs mechanism by invoking a phase transition in the early universe, at a critical temperature [Tc] below which the symmetry is restored. The spontaneous breakdown of the vacuum state generates an external time, and the wave function of the universe satisfies a time-dependent Schroedinger equation, which reduces to the Wheeler-deWitt equation in the classical regime for T<[Tc], allowing a semiclassical WKB approximation to the wave function. The conservation of energy is spontaneously violated for T>[Tc], and matter is created fractions of seconds after the big bang, generating the matter in the Universe. The time direction of the vacuum expectation value of the scalar Higgs field generates a time asymmetry, which defines the cosmological arrow of time and the direction of increasing entropy as the Lorentz symmetry is restored at low temperatures. 52 refs.
Quantum Gravity, the Origin of Time and Time's Arrow
J. W. Moffat
1992-09-02T23:59:59.000Z
The local Lorentz and diffeomorphism symmetries of Einstein's gravitational theory are spontaneously broken by a Higgs mechanism by invoking a phase transition in the early Universe, at a critical temperature $T_c$ below which the symmetry is restored. The spontaneous breakdown of the vacuum state generates an external time and the wave function of the Universe satisfies a time dependent Schrodinger equation, which reduces to the Wheeler-deWitt equation in the classical regime for $T T_c$ and matter is created fractions of seconds after the big bang, generating the matter in the Universe. The time direction of the vacuum expectation value of the scalar Higgs field generates a time asymmetry, which defines the cosmological arrow of time and the direction of increasing entropy as the Lorentz symmetry is restored at low temperatures.
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.
Boltzmann Equation for Relativistic Neutral Scalar Field in Non-equilibrium Thermo Field Dynamics
Yuichi Mizutani; Tomohiro Inagaki
2011-03-18T23:59:59.000Z
A relativistic neutral scalar field is investigated on the basis of the Schwinger-Dyson equation in the non-equilibrium thermo field dynamics. A time evolution equation for a distribution function is obtained from a diagonalization condition for the Schwinger-Dyson equation. An explicit expression of the time evolution equation is calculated in the $\\lambda\\phi^4$ interaction model at the 2-loop level. The Boltzmann equation is derived for the relativistic scalar field. We set a simple initial condition and numerically solve the Boltzmann equation and show the time evolution of the distribution function and the relaxation time.
Motional Spin Relaxation in Large Electric Fields
Riccardo Schmid; B. Plaster; B. W. Filippone
2008-07-02T23:59:59.000Z
We discuss the precession of spin-polarized Ultra Cold Neutrons (UCN) and $^{3}$He atoms in uniform and static magnetic and electric fields and calculate the spin relaxation effects from motional $v\\times E$ magnetic fields. Particle motion in an electric field creates a motional $v\\times E$ magnetic field, which when combined with collisions, produces variations of the total magnetic field and results in spin relaxation of neutron and $^{3}$He samples. The spin relaxation times $T_{1}$ (longitudinal) and $T_{2}$ (transverse) of spin-polarized UCN and $^{3}$He atoms are important considerations in a new search for the neutron Electric Dipole Moment at the SNS \\emph{nEDM} experiment. We use a Monte Carlo approach to simulate the relaxation of spins due to the motional $v\\times E$ field for UCN and for $^{3}$He atoms at temperatures below $600,\\mathrm{mK}$. We find the relaxation times for the neutron due to the $v\\times E$ effect to be long compared to the neutron lifetime, while the $^{3}$He relaxation times may be important for the \\emph{nEDM} experiment.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
UGE Scheduler Cycle Time UGE Scheduler Cycle Time Genepool Cycle Time Genepool Daily Genepool Weekly Phoebe Cycle Time Phoebe Daily Phoebe Weekly What is the Scheduler Cycle? The...
Visualization of time-dependent seismic vector fields with glyphs
McQuinn, Emmett
2010-01-01T23:59:59.000Z
for rigorous seismic data exploration. Thus the mo- tivationsliprate for rich exploration of seismic data. Related Worksand interactive exploration of seismic data. The proposed
Differences in Impact Factor Across Fields and Over Time
Althouse, Benjamin M.; West, Jevin D.; Bergstrom, Ted C; Bergstrom, Carl T.
2008-01-01T23:59:59.000Z
Pharmacology Agriculture Crop Science Geography SociologyPharmacology Agriculture Crop Science Ecology & EvolutionPharmacology Agriculture Crop Science Geography Sociology
Differences in Impact Factor Across Fields and Over Time
Althouse, Benjamin M.; West, Jevin D.; Bergstrom, Ted C; Bergstrom, Carl T.
2008-01-01T23:59:59.000Z
Applied Acoustics Environmental Chemistry & MicrobiologyApplied Acoustics Environmental Chemistry & MicrobiologyApplied Acoustics Environmental Chemistry & Microbiology
Time Commitments Where Does Your Time Go
Kunkle, Tom
Time Commitments Where Does Your Time Go Everyone starts the week with the same number of hours. So, why does your time go so fast? Let's find out! Number of hours of sleep each night ____ x 7 preparation/clean-up time) ____ x 7 = ____ Travel time to and from campus ___ x __ = ____ Number of hours per
Space and time from translation symmetry
Albert Schwarz
2009-05-16T23:59:59.000Z
We show that the notions of space and time in algebraic quantum field theory arise from translation symmetry if we assume asymptotic commutativity. We argue that this construction can be applied to string theory.
Kemner, Ken
Eddy-Current-Induced Multipole Field Calculations September 29, 2003 1 Eddy-Current-Induced Multipole Field Calculations Nicholas S. Sereno, Suk H. Kim 1.0 Abstract Time-varying magnetic fields-current-induced multipole fields from higher multipole magnets (quadrupole, sextupole, etc.). Finally, transient effects
Space-time Curvature of Classical Electromagnetism
R. W. M. Woodside
2004-10-08T23:59:59.000Z
The space-time curvature carried by electromagnetic fields is discovered and a new unification of geometry and electromagnetism is found. Curvature is invariant under charge reversal symmetry. Electromagnetic field equations are examined with De Rham co homology theory. Radiative electromagnetic fields must be exact and co exact to preclude unobserved massless topological charges. Weyl's conformal tensor, here called ``the gravitational field'', is decomposed into a divergence-free non-local piece with support everywhere and a local piece with the same support as the matter. By tuning a local gravitational field to a Maxwell field the electromagnetic field's local gravitational field is discovered. This gravitational field carries the electromagnetic field's polarization or phase information, unlike Maxwell's stress-energy tensor. The unification assumes Einstein's equations and derives Maxwell's equations from curvature assumptions. Gravity forbids magnetic monopoles! This unification is stronger than the Einstein-Maxwell equations alone, as those equations must produce the electromagnetic field's local gravitational field and not just any conformal tensor. Charged black holes are examples. Curvature of radiative null electromagnetic fields is characterized.
Renormalization and quantum field theory
R. E. Borcherds
2011-03-09T23:59:59.000Z
The aim of this paper is to describe how to use regularization and renormalization to construct a perturbative quantum field theory from a Lagrangian. We first define renormalizations and Feynman measures, and show that although there need not exist a canonical Feynman measure, there is a canonical orbit of Feynman measures under renormalization. We then construct a perturbative quantum field theory from a Lagrangian and a Feynman measure, and show that it satisfies perturbative analogues of the Wightman axioms, extended to allow time-ordered composite operators over curved spacetimes.
Haag's theorem in noncommutative quantum field theory
Antipin, K. V. [Moscow State University, Faculty of Physics (Russian Federation)] [Moscow State University, Faculty of Physics (Russian Federation); Mnatsakanova, M. N., E-mail: mnatsak@theory.sinp.msu.ru [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation); Vernov, Yu. S. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)] [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)
2013-08-15T23:59:59.000Z
Haag's theorem was extended to the general case of noncommutative quantum field theory when time does not commute with spatial variables. It was proven that if S matrix is equal to unity in one of two theories related by unitary transformation, then the corresponding one in the other theory is equal to unity as well. In fact, this result is valid in any SO(1, 1)-invariant quantum field theory, an important example of which is noncommutative quantum field theory.
Haag's Theorem in Noncommutative Quantum Field Theory
K. V. Antipin; M. N. Mnatsakanova; Yu. S. Vernov
2012-02-05T23:59:59.000Z
Haag's theorem was extended to noncommutative quantum field theory in a general case when time does not commute with spatial variables. It was proven that if S-matrix is equal to unity in one of two theories related by unitary transformation, then the corresponding one in another theory is equal to unity as well. In fact this result is valid in any SO(1,1) invariant quantum field theory, of which an important example is noncommutative quantum field theory.
Hyperbolic statics in space-time
Dmitry Pavlov; Sergey Kokarev
2014-12-11T23:59:59.000Z
Based on the concept of material event as an elementary material source that is concentrated on metric sphere of zero radius --- light-cone of Minkowski space-time, we deduce the analog of Coulomb's law for hyperbolic space-time field universally acting between the events of space-time. Collective field that enables interaction of world lines of a pair of particles at rest contains a standard 3-dimensional Coulomb's part and logarithmic addendum. We've found that the Coulomb's part depends on a fine balance between causal and geometric space-time characteristics (the two regularizations concordance).
External split field generator
Thundat, Thomas George (Knoxville, TN); Van Neste, Charles W. (Kingston, TN); Vass, Arpad Alexander (Oak Ridge, TN)
2012-02-21T23:59:59.000Z
A generator includes a coil disposed about a core. A first stationary magnetic field source may be disposed on a first end portion of the core and a second stationary magnetic field source may be disposed on a second end portion of core. The first and second stationary magnetic field sources apply a stationary magnetic field to the coil. An external magnetic field source may be disposed outside the coil to apply a moving magnetic field to the coil. Electrical energy is generated in response to an interaction between the coil, the moving magnetic field, and the stationary magnetic field.
Chiral effective field theory and nuclear forces
R. Machleidt; D. R. Entem
2011-05-15T23:59:59.000Z
We review how nuclear forces emerge from low-energy QCD via chiral effective field theory. The presentation is accessible to the non-specialist. At the same time, we also provide considerable detailed information (mostly in appendices) for the benefit of researchers who wish to start working in this field.
Electric Field Quench, Equilibration and Universal Behavior
M. Ali-Akbari; S. Amiri-Sharifi; H. R. Sepangi
2015-04-14T23:59:59.000Z
We study electric field quench in N=2 strongly coupled gauge theory, using the AdS/CFT correspondence. To do so, we consider the aforementioned system which is subjected to a time-dependent electric field indicating an out of equilibrium system. Defining the equilibration time t_{eq}, at which the system relaxes to its final equilibrium state after injecting the energy, we find that the rescaled equilibriation time k^{-1}t_{eq} decreases as the transition time k increases. Therefore, we expect that for sufficiently large transition time, k ->infinity, the relaxation of the system to its final equilibrium can be an adiabatic process. On the other hand, we observe a universal behavior for the fast quenches, k electric field. Our calculations generalized to systems in various dimensions also confirm universalization process which seems to be a typical feature of all strongly coupled gauge theories that admit a gravitational dual.
Exterior Differential Systems for Field Theories
Frank B. Estabrook
2015-02-24T23:59:59.000Z
Exterior Differential Systems (EDS) and Cartan forms, set in the state space of field variables taken together with four space-time variables, are formulated for classical gauge theories of Maxwell and SU(2) Yang-Mills fields minimally coupled to Dirac spinor multiplets. Cartan character tables are calculated, showing whether the EDS, and so the Euler-Lagrange partial differential equations, is well-posed. The first theory, with 22 dimensional state space (10 Maxwell field and potential components and 8 components of a Dirac field), anticipates QED. In the second, non-Abelian, case (30 Yang-Mills field components and 16 Dirac), only if three additional "ghost" fields are included (15 more scalar variables) is a well-posed EDS found. This classical formulation anticipates the need for introduction of Fadeev-Popov ghost fields in the quantum standard model.
Noncommutative field theory from twisted Fock space
Bu, Jong-Geon; Kim, Hyeong-Chan; Lee, Youngone; Vac, Chang Hyon; Yee, Jae Hyung [Department of Physics, Yonsei University, Seoul (Korea, Republic of)
2006-06-15T23:59:59.000Z
We construct a quantum field theory in noncommutative space time by twisting the algebra of quantum operators (especially, creation and annihilation operators) of the corresponding quantum field theory in commutative space time. The twisted Fock space and S-matrix consistent with this algebra have been constructed. The resultant S-matrix is consistent with that of Filk [Tomas Filk, Phys. Lett. B 376, 53 (1996).]. We find from this formulation that the spin-statistics relation is not violated in the canonical noncommutative field theories.
Pavlovic, M. Z.; Urosevic, D.; Arbutina, B. [Department of Astronomy, Faculty of Mathematics, University of Belgrade, Studentski trg 16, 11000 Belgrade (Serbia); Vukotic, B. [Astronomical Observatory, Volgina 7, 11060 Belgrade 38 (Serbia); Goeker, Ue. D., E-mail: marko@math.rs [Physics Department, Bogazici University, Bebek 34342, Istanbul (Turkey)
2013-01-15T23:59:59.000Z
In this paper, we present new empirical radio surface-brightness-to-diameter ({Sigma}-D) relations for supernova remnants (SNRs) in our Galaxy. We also present new theoretical derivations of the {Sigma}-D relation based on equipartition or on a constant ratio between cosmic rays and magnetic field energy. A new calibration sample of 60 Galactic SNRs with independently determined distances is created. Instead of (standard) vertical regression, used in previous papers, different fitting procedures are applied to the calibration sample in the log {Sigma}-log D plane. Non-standard regressions are used to satisfy the requirement that values of parameters obtained from the fitting of {Sigma}-D and D-{Sigma} relations should be invariant within estimated uncertainties. We impose symmetry between {Sigma}-D and D-{Sigma} due to the existence of large scatter in both D and {Sigma}. Using four fitting methods that treat {Sigma} and D symmetrically, different {Sigma}-D slopes {beta} are obtained for the calibration sample. Monte Carlo simulations verify that the slopes of the empirical {Sigma}-D relation should be determined by using orthogonal regression because of its good performance in data sets with severe scatter. The slope derived here ({beta} = 4.8) is significantly steeper than those derived in previous studies. This new slope is closer to the updated theoretically predicted surface-brightness-diameter slope in the radio range of the Sedov phase. We also analyze the empirical {Sigma}-D relations for SNRs in a dense environment of molecular clouds and for SNRs evolving in the lower-density interstellar medium. Applying new empirical relations to estimate distances of Galactic SNRs results in a dramatically changed distance scale.
The Time Evolution of Aerosol Size Distribution Over the Mexico...
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Size Distribution Over the Mexico City Plateau. The Time Evolution of Aerosol Size Distribution Over the Mexico City Plateau. Abstract: As part of the MILAGRO field campaign, the...
Sensor for detecting changes in magnetic fields
Praeg, W.F.
1980-02-26T23:59:59.000Z
A sensor is described for detecting changes in the magnetic field of the equilibrium-field coil of a Tokamak plasma device that comprises a pair of bifilar wires disposed circumferentially, one inside and one outside the equilibrium-field coil. Each is shorted at one end. The difference between the voltages detected at the other ends of the bifilar wires provides a measure of changing flux in the equilibrium-field coil. This difference can be used to detect faults in the coil in time to take action to protect the coil.
Sensor for detecting changes in magnetic fields
Praeg, Walter F. (Palos Park, IL)
1981-01-01T23:59:59.000Z
A sensor for detecting changes in the magnetic field of the equilibrium-field coil of a Tokamak plasma device comprises a pair of bifilar wires disposed circumferentially, one inside and one outside the equilibrium-field coil. Each is shorted at one end. The difference between the voltages detected at the other ends of the bifilar wires provides a measure of changing flux in the equilibrium-field coil. This difference can be used to detect faults in the coil in time to take action to protect the coil.
Non-Equilibrium Thermo Field Dynamics for Relativistic Complex Scalar and Dirac Fields
Yuichi Mizutani; Tomohiro Inagaki
2012-05-02T23:59:59.000Z
Relativistic quantum field theories for complex scalar and Dirac fields are investigated in non-equilibrium thermo field dynamics. The thermal vacuum is defined by the Bogoliubov transformed creation and annihilation operators. Two independent Bogoliubov parameters are introduced for a charged field. Its difference naturally induces the chemical potential. Time-dependent thermal Bogoliubov transformation generates the thermal counter terms. We fix the terms by the self-consistency renormalization condition. Evaluating the thermal self-energy under the self-consistency renormalization condition, we derive the quantum Boltzmann equations for the relativistic fields.
Noncommutative field gas driven inflation
Luciano Barosi; Francisco A. Brito; Amilcar R. Queiroz
2008-03-14T23:59:59.000Z
We investigate early time inflationary scenarios in an Universe filled with a dilute noncommutative bosonic gas at high temperature. A noncommutative bosonic gas is a gas composed of bosonic scalar field with noncommutative field space on a commutative spacetime. Such noncommutative field theories was recently introduced as a generalization of quantum mechanics on a noncommutative spacetime. As key features of these theories are Lorentz invariance violation and CPT violation. In the present study we use a noncommutative bosonic field theory that besides the noncommutative parameter $\\theta$ shows up a further parameter $\\sigma$. This parameter $\\sigma$ controls the range of the noncommutativity and acts as a regulator for the theory. Both parameters play a key role in the modified dispersion relations of the noncommutative bosonic field, leading to possible striking consequences for phenomenology. In this work we obtain an equation of state $p=\\omega(\\sigma,\\theta;\\beta)\\rho$ for the noncommutative bosonic gas relating pressure $p$ and energy density $\\rho$, in the limit of high temperature. We analyse possible behaviours for this gas parameters $\\sigma$, $\\theta$ and $\\beta$, so that $-1\\leq\\omega<-1/3$, which is the region where the Universe enters an accelerated phase.
Noncommutative field gas driven inflation
Barosi, Luciano; Brito, Francisco A [Departamento de Fisica, Universidade Federal de Campina Grande, Caixa Postal 10071, 58109-970 Campina Grande, Paraiba (Brazil); Queiroz, Amilcar R, E-mail: lbarosi@ufcg.edu.br, E-mail: fabrito@df.ufcg.edu.br, E-mail: amilcarq@gmail.com [Centro Internacional de Fisica da Materia Condensada, Universidade de Brasilia, Caixa Postal 04667, Brasilia, DF (Brazil)
2008-04-15T23:59:59.000Z
We investigate early time inflationary scenarios in a Universe filled with a dilute noncommutative bosonic gas at high temperature. A noncommutative bosonic gas is a gas composed of a bosonic scalar field with noncommutative field space on a commutative spacetime. Such noncommutative field theories were recently introduced as a generalization of quantum mechanics on a noncommutative spacetime. Key features of these theories are Lorentz invariance violation and CPT violation. In the present study we use a noncommutative bosonic field theory that, besides the noncommutative parameter {theta}, shows up a further parameter {sigma}. This parameter {sigma} controls the range of the noncommutativity and acts as a regulator for the theory. Both parameters play a key role in the modified dispersion relations of the noncommutative bosonic field, leading to possible striking consequences for phenomenology. In this work we obtain an equation of state p = {omega}({sigma},{theta};{beta}){rho} for the noncommutative bosonic gas relating pressure p and energy density {rho}, in the limit of high temperature. We analyse possible behaviours for these gas parameters {sigma}, {theta} and {beta}, so that -1{<=}{omega}<-1/3, which is the region where the Universe enters an accelerated phase.
Electromagnetic field with constraints and Papapetrou equation
Z. Ya. Turakulov; A. T. Muminov
2006-01-12T23:59:59.000Z
It is shown that geometric optical description of electromagnetic wave with account of its polarization in curved space-time can be obtained straightforwardly from the classical variational principle for electromagnetic field. For this end the entire functional space of electromagnetic fields must be reduced to its subspace of locally plane monochromatic waves. We have formulated the constraints under which the entire functional space of electromagnetic fields reduces to its subspace of locally plane monochromatic waves. These constraints introduce variables of another kind which specify a field of local frames associated to the wave and contain some congruence of null-curves. The Lagrangian for constrained electromagnetic field contains variables of two kinds, namely, a congruence of null-curves and the field itself. This yields two kinds of Euler-Lagrange equations. Equations of first kind are trivial due to the constraints imposed. Variation of the curves yields the Papapetrou equations for a classical massless particle with helicity 1.
Lillaney, Prasheel; Pelc, Norbert [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Bioengineering, Stanford University, Stanford, California 94305 (United States); Shin Mihye [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Hinshaw, Waldo; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Bennett, N. Robert [Department of Radiology, Stanford University, Stanford, California 94305 and Qualcomm MEMS Technologies, San Jose, California 95134 (United States)
2013-02-15T23:59:59.000Z
Purpose: Using hybrid x-ray/MR (XMR) systems for image guidance during interventional procedures could enhance the diagnosis and treatment of neurologic, oncologic, cardiovascular, and other disorders. The authors propose a close proximity hybrid system design in which a C-arm fluoroscopy unit is placed immediately adjacent to the solenoid magnet of a MR system with a minimum distance of 1.2 m between the x-ray and MR imaging fields of view. Existing rotating anode x-ray tube designs fail within MR fringe field environments because the magnetic fields alter the electron trajectories in the x-ray tube and act as a brake on the induction motor, reducing the rotation speed of the anode. In this study the authors propose a novel motor design that avoids the anode rotation speed reduction. Methods: The proposed design replaces the permanent magnet stator found in brushed dc motors with the radial component of the MR fringe field. The x-ray tube is oriented such that the radial component of the MR fringe field is orthogonal to the cathode-anode axis. Using a feedback position sensor and the support bearings as electrical slip rings, the authors use electrical commutation to eliminate the need for mechanical brushes and commutators. A vacuum compatible prototype of the proposed motor design was assembled, and its performance was evaluated at various operating conditions. The prototype consisted of a 3.1 in. diameter anode rated at 300 kHU with a ceramic rotor that was 5.6 in. in length and had a 2.9 in. diameter. The material chosen for all ceramic components was MACOR, a machineable glass ceramic developed by Corning Inc. The approximate weight of the entire assembly was 1750 g. The maximum rotation speed, angular acceleration, and acceleration time of the motor design were investigated, as well as the dependence of these parameters on rotor angular offset, magnetic field strength, and field orientation. The resonance properties of the authors' assembly were also evaluated to determine its stability during acceleration, and a pulse width modulation algorithm was implemented to control the rotation speed of the motor. Results: At a magnetic flux density of 41 mT orthogonal to the axis of rotation (on the lower end of the expected flux density in the MR suite) the maximum speed of the motor was found to be 5150 revolutions per minute (rpm). The acceleration time necessary to reach 3000 rpm was found to be approximately 10 s at 59 mT. The resonance frequency of the assembly with the anode attached was 1310 rpm (21.8 Hz) which is far below the desired operating speeds. Pulse width modulation provides an effective method to control the speed of the motor with a resolution of 100 rpm. Conclusions: The proposed design can serve as a direct replacement to the conventional induction motor used in rotating anode x-ray tubes. It does not suffer from a reduced rotation speed when operating in a MR environment. The presence of chromic steel bearings in the prototype prevented testing at the higher field strengths, and future iterations of the design could eliminate this shortcoming. The prototype assembly demonstrates proof of concept of the authors' design and overcomes one of the major obstacles for a MR compatible rotating anode x-ray tube.
Time Crystals from Minimum Time Uncertainty
Mir Faizal; Mohammed M. Khalil; Saurya Das
2014-12-29T23:59:59.000Z
Motivated by the Generalized Uncertainty Principle, covariance, and a minimum measurable time, we propose a deformation of the Heisenberg algebra, and show that this leads to corrections to all quantum mechanical systems. We also demonstrate that such a deformation implies a discrete spectrum for time. In other words, time behaves like a crystal.
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OIL & GAS FIELD OUTLINES FROM BUFFERED WELLS The VBA Code below builds oil & gas field boundary outlines (polygons) from buffered wells (points). Input well points layer must be a...
Hull, Chris
The zero modes of closed strings on a torus — the torus coordinates plus dual coordinates conjugate to winding number — parameterize a doubled torus. In closed string field theory, the string field depends on all zero-modes ...
Covariant Noncommutative Field Theory
Estrada-Jimenez, S. [Licenciaturas en Fisica y en Matematicas, Facultad de Ingenieria, Universidad Autonoma de Chiapas Calle 4a Ote. Nte. 1428, Tuxtla Gutierrez, Chiapas (Mexico); Garcia-Compean, H. [Departamento de Fisica, Centro de Investigacion y de Estudios Avanzados del IPN P.O. Box 14-740, 07000 Mexico D.F., Mexico and Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Monterrey Via del Conocimiento 201, Parque de Investigacion e Innovacion Tecnologica (PIIT) Autopista nueva al Aeropuerto km 9.5, Lote 1, Manzana 29, cp. 66600 Apodaca Nuevo Leon (Mexico); Obregon, O. [Instituto de Fisica de la Universidad de Guanajuato P.O. Box E-143, 37150 Leon Gto. (Mexico); Ramirez, C. [Facultad de Ciencias Fisico Matematicas, Universidad Autonoma de Puebla, P.O. Box 1364, 72000 Puebla (Mexico)
2008-07-02T23:59:59.000Z
The covariant approach to noncommutative field and gauge theories is revisited. In the process the formalism is applied to field theories invariant under diffeomorphisms. Local differentiable forms are defined in this context. The lagrangian and hamiltonian formalism is consistently introduced.
Kaiser, David I.
Particle cosmology is among the hottest of hot topics in physics today. The field investigates the smallest units of matter and their role in determining the shape and fate of the entire universe. In recent years the field ...
Renormalisation of Noncommutative Quantum Field Harald Grosse1
Wulkenhaar, Raimar
Renormalisation of Noncommutative Quantum Field Theory Harald Grosse1 and Raimar Wulkenhaar2 1 recall some models for noncommutative space-time and discuss quantum field theories on these deformed. Keywords: noncommutative geometry; quantum field theory; renormalisation AMS Subject Classification: 81T15
Electric field divertor plasma pump
Schaffer, M.J.
1994-10-04T23:59:59.000Z
An electric field plasma pump includes a toroidal ring bias electrode positioned near the divertor strike point of a poloidal divertor of a tokamak, or similar plasma-confining apparatus. For optimum plasma pumping, the separatrix of the poloidal divertor contacts the ring electrode, which then also acts as a divertor plate. A plenum or other duct near the electrode includes an entrance aperture open to receive electrically-driven plasma. The electrode is insulated laterally with insulators, one of which is positioned opposite the electrode at the entrance aperture. An electric field E is established between the ring electrode and a vacuum vessel wall, with the polarity of the bias applied to the electrode being relative to the vessel wall selected such that the resultant electric field E interacts with the magnetic field B already existing in the tokamak to create an E [times] B/B[sup 2] drift velocity that drives plasma into the entrance aperture. The pumped plasma flow into the entrance aperture is insensitive to variations, intentional or otherwise, of the pump and divertor geometry. Pressure buildups in the plenum or duct connected to the entrance aperture in excess of 10 mtorr are achievable. 11 figs.
Electric field divertor plasma pump
Schaffer, Michael J. (San Diego, CA)
1994-01-01T23:59:59.000Z
An electric field plasma pump includes a toroidal ring bias electrode (56) positioned near the divertor strike point of a poloidal divertor of a tokamak (20), or similar plasma-confining apparatus. For optimum plasma pumping, the separatrix (40) of the poloidal divertor contacts the ring electrode (56), which then also acts as a divertor plate. A plenum (54) or other duct near the electrode (56) includes an entrance aperture open to receive electrically-driven plasma. The electrode (56) is insulated laterally with insulators (63,64), one of which (64) is positioned opposite the electrode at the entrance aperture. An electric field E is established between the ring electrode (56) and a vacuum vessel wall (22), with the polarity of the bias applied to the electrode being relative to the vessel wall selected such that the resultant electric field E interacts with the magnetic field B already existing in the tokamak to create an E.times.B/B.sup.2 drift velocity that drives plasma into the entrance aperture. The pumped plasma flow into the entrance aperture is insensitive to variations, intentional or otherwise, of the pump and divertor geometry. Pressure buildups in the plenum or duct connected to the entrance aperture in excess of 10 mtorr are achievable.
Space time and the passage of time
George F. R. Ellis; Rituparno Goswami
2012-08-26T23:59:59.000Z
This paper examines the various arguments that have been put forward suggesting either that time does not exist, or that it exists but its flow is not real. I argue that (i) time both exists and flows; (ii) an Evolving Block Universe (`EBU') model of spacetime adequately captures this feature, emphasizing the key differences between the past, present, and future; (iii) the associated surfaces of constant time are uniquely geometrically and physically determined in any realistic spacetime model based in General Relativity Theory; (iv) such a model is needed in order to capture the essential aspects of what is happening in circumstances where initial data does not uniquely determine the evolution of spacetime structure because quantum uncertainty plays a key role in that development. Assuming that the functioning of the mind is based in the physical brain, evidence from the way that the mind apprehends the flow of time prefers this evolving time model over those where there is no flow of time.
Four-dimensional deformed special relativity from group field theories
Girelli, Florian [SISSA, Via Beirut 2-4, 34014 Trieste, Italy and INFN, Sezione di Trieste (Italy); School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia); Livine, Etera R. [Laboratoire de Physique, ENS Lyon, CNRS UMR 5672, 46 Allee d'Italie, 69007 Lyon (France); Oriti, Daniele [Perimeter Institute for Theoretical Physics, 31 Caroline St, Waterloo, Ontario N2L 2Y5 (Canada); Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, Utrecht 3584 TD (Netherlands); Albert Einstein Institute, Am Muehlenberg 4, Golm (Germany)
2010-01-15T23:59:59.000Z
We derive a scalar field theory of the deformed special relativity type, living on noncommutative {kappa}-Minkowski space-time and with a {kappa}-deformed Poincare symmetry, from the SO(4,1) group field theory defining the transition amplitudes for topological BF theory in 4 space-time dimensions. This is done at a nonperturbative level of the spin foam formalism working directly with the group field theory (GFT). We show that matter fields emerge from the fundamental model as perturbations around a specific phase of the GFT, corresponding to a solution of the fundamental equations of motion, and that the noncommutative field theory governs their effective dynamics.
Magnetic helicity generation from the cosmic axion field
Campanelli, L.; Giannotti, M. [Dipartimento di Fisica, Universita di Ferrara, I-44100 Ferrara (Italy); INFN-Sezione di Ferrara, I-44100 Ferrara (Italy)
2005-12-15T23:59:59.000Z
The coupling between a primordial magnetic field and the cosmic axion field generates a helical component of the magnetic field around the time in which the axion starts to oscillate. If the energy density of the seed magnetic field is comparable to the energy density of the universe at that time, then the resulting magnetic helicity is about vertical bar H{sub B} vertical bar {approx_equal}(10{sup -20}G){sup 2} kpc and remains constant after its generation. As a corollary, we find that the standard properties of the oscillating axion remain unchanged even in the presence of very strong magnetic fields.
Magnetic Helicity Generation from the Cosmic Axion Field
L. Campanelli; M. Giannotti
2005-12-12T23:59:59.000Z
The coupling between a primordial magnetic field and the cosmic axion field generates a helical component of the magnetic field around the time in which the axion starts to oscillate. If the energy density of the seed magnetic field is comparable to the energy density of the universe at that time, then the resulting magnetic helicity is about |H_B| \\simeq (10^{-20} G)^2 kpc and remains constant after its generation. As a corollary, we find that the standard properties of the oscillating axion remain unchanged even in the presence of very strong magnetic fields.
Noncommutative scalar fields from symplectic deformation
Daoud, M. [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34014 Trieste (Italy); Hamama, A. [High Energy Laboratory, Faculty of Sciences, University Mohamed V, P.O. Box 1014, Rabat (Morocco)
2008-02-15T23:59:59.000Z
This paper is concerned with the quantum theory of noncommutative scalar fields in two dimensional space-time. It is shown that the noncommutativity originates from the the deformation of symplectic structures. The quantization is performed and the modes expansions of the fields, in the presence of an electromagnetic background, are derived. The Hamiltonian of the theory is given and the degeneracies lifting, induced by the deformation, is also discussed.
Localized Axion Photon States in a Strong Magnetic Field
E. I. Guendelman
2008-01-04T23:59:59.000Z
We consider the axion field and electromagnetic waves with rapid time dependence, coupled to a strong time independent, asymptotically approaching a constant at infinity "mean" magnetic field, which takes into account the back reaction from the axion field and electromagnetic waves with rapid time dependence in a time averaged way. The direction of the self consistent mean field is orthogonal to the common direction of propagation of the axion and electromagnetic waves with rapid time dependence and parallel to the polarization of these electromagnetic waves. Then, there is an effective U(1) symmetry mixing axions and photons. Using the natural complex variables that this U(1) symmetry suggests we find localized planar soliton solutions. These solutions appear to be stable since they produce a different magnetic flux than the state with only a constant magnetic field, which we take as our "ground state". The solitons also have non trivial U(1) charge defined before, different from the uncharged vacuum.
Alexander N. Jourjine
2010-03-12T23:59:59.000Z
We develop further the formalism of the non-Abelian gauge field theory on a cell complex space-time and show how the gauge-invariant action and the equations of motion for gauge fields interacting with spinors can be written without a reference to the geometrical nature of the cells of the cell complex. The general results are illustrated with examples of solutions of equations of motion for U(N) and SU(N) gauge groups.
Yuichi Mizutani; Tomohiro Inagaki; Yusuke Nakamura; Yoshiya Yamanaka
2011-09-05T23:59:59.000Z
A relativistic neutral scalar field is investigated in non-equilibrium thermo field dynamics. The canonical quantization is applied to the fields out of equilibrium. Because the thermal Bogoliubov transformation becomes time-dependent, the equations of motion for the ordinary unperturbed creation and annihilation operators are modified. This forces us to introduce a thermal counter term in the interaction Hamiltonian which generates additional radiative corrections. Imposing the self-consistency renormalization condition on the total radiative corrections, we obtain the quantum Boltzmann equation for the relativistic scalar field.
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Insights from Agricultural GHG Offset studies
McCarl, Bruce A.
Ron Sands PNNL Maryland Man Keun Kim PNNL Maryland Francisco de Lachesnaye EPA Heng-Chi Lee Waterloo
Financing Residential Energy Efficiency with Carbon Offsets
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankShale_Gas.pdfServiceDepartmentEnergy 9: AugustFinancial Statement:Alternatives for
Discounts, Fungibility and Agricultural GHG Offset projects
McCarl, Bruce A.
in MMT of Carbon Equivalents Soil Carbon Sequestration Discount for Saturating Sinks No Sink Discounting of Carbon Equivalents Carbon Sequestration from Trees Discount for Saturating Sinks No Sink Discounting 0.S. Agricultural and Forest Carbon Sequestration," 2003. #12;FungibilityFungibility A number of concepts have
Experience with Offset Collisions in the LHC
Papotti, G; Calaga, R; Follin, F; Giachino, R; Herr, W; Miyamoto, R; Pieloni, T; Schaumann, M
2011-01-01T23:59:59.000Z
To keep the luminosity under control, some experiments require the adjustment of the luminosity during a fill, socalled luminosity levelling. One option is the separate the beams transversely and adjust the separation to the desired collision rate. The results from controlled experiments are reported and interpreted. The feasibility of this method for ultimate luminosities is discussed.
Explaining the Price of Voluntary Carbon Offsets
Conte, Marc N.; Kotchen, Matthew
2009-01-01T23:59:59.000Z
on fuel efficiency, hydropower, fuel substitution, solarbiomass methane, wind, hydropower, solar, and other. 8 OECDtypes of biomass methane, hydropower, so- lar, and wind. All
Homebuyer Solar Option and Solar Offset Program
Broader source: Energy.gov [DOE]
Senate Bill 1 of 2006, which established the statewide California Solar Initiative, also required the California Energy Commission (CEC) to implement regulations that require sellers of production...
Shape Smoothing using Double Offsets Frederic Chazal
Thibert, Boris
. Assuming the solid to be made of a hard material (like steel) one embed it in a bloc of wax. Then one uses a ball of given radius to remove as #12;much wax as possible to obtain the solid on the middle of the fig it with wax and remove (from the inside!) as much wax as possible with a ball. Taking again the complement
?-Decay in Ultra-Intense Laser Fields
Serban Misicu; Margarit Rizea
2013-07-05T23:59:59.000Z
We investigate the \\alpha-decay of a spherical nucleus under the influence of an ultra-intense laser field for the case when the radius vector joining the center-of-masses of the \\alpha-particle and the daughter is aligned with the direction of the external field. The time-independent part of the \\alpha-daughter interaction is taken from elastic scattering compilations whereas the time-varying part describes the interaction between the decaying system with the laser field. The time-dependent Schr\\"odinger equation is solved numerically by appealing to a modified scheme of the Crank-Nicolson type where an additional first-order time derivative appears compared to the field-free case. The tunneling probability of the \\alpha-cluster, and derived quantities (decay rate, total flux) is determined for various laser intensities and frequencies for either continous waves or few-cycle pulses of envelope function F(t)=1. We show that in the latter case pulse sequences containing an odd number of half-cycles determine an enhancement of the tunneling probability compared to the field-free case and the continuous wave case. The present study is carried out taking as example the alpha decaying nucleus $^{106}$Te.
Neutron Interferometry constrains dark energy chameleon fields
Lemmel, H; Ivanov, A N; Jenke, T; Pignol, G; Pitschmann, M; Potocar, T; Wellenzohn, M; Zawisky, M; Abele, H
2015-01-01T23:59:59.000Z
We present phase shift measurements for neutron matter waves in vacuum and in low pressure Helium using a method originally developed for neutron scattering length measurements in neutron interferometry. We search for phase shifts associated with a coupling to scalar fields. We set stringent limits for a scalar chameleon field, a prominent quintessence dark energy candidate. We find that the coupling constant $\\beta$ is less than 1.9 $\\times10^7$~for $n=1$ at 95\\% confidence level, where $n$ is an input parameter of the self--interaction of the chameleon field $\\varphi$ inversely proportional to $\\varphi^n$.
Three approaches to classical thermal field theory
Gozzi, E., E-mail: gozzi@ts.infn.it [Department of Physics, University of Trieste, Strada Costiera 11, Miramare - Grignano, 34151 Trieste (Italy); INFN, Sezione di Trieste (Italy); Penco, R., E-mail: rpenco@syr.edu [Department of Physics, Syracuse University, Syracuse, NY 13244-1130 (United States)
2011-04-15T23:59:59.000Z
Research Highlights: > Classical thermal field theory admits three equivalent path integral formulations. > Classical Feynman rules can be derived for all three formulations. > Quantum Feynman rules reduce to classical ones at high temperatures. > Classical Feynman rules become much simpler when superfields are introduced. - Abstract: In this paper we study three different functional approaches to classical thermal field theory, which turn out to be the classical counterparts of three well-known different formulations of quantum thermal field theory: the closed-time path (CTP) formalism, the thermofield dynamics (TFD) and the Matsubara approach.
Neutron Interferometry constrains dark energy chameleon fields
H. Lemmel; Ph. Brax; A. N. Ivanov; T. Jenke; G. Pignol; M. Pitschmann; T. Potocar; M. Wellenzohn; M. Zawisky; H. Abele
2015-02-20T23:59:59.000Z
We present phase shift measurements for neutron matter waves in vacuum and in low pressure Helium using a method originally developed for neutron scattering length measurements in neutron interferometry. We search for phase shifts associated with a coupling to scalar fields. We set stringent limits for a scalar chameleon field, a prominent quintessence dark energy candidate. We find that the coupling constant $\\beta$ is less than 1.9 $\\times10^7$~for $n=1$ at 95\\% confidence level, where $n$ is an input parameter of the self--interaction of the chameleon field $\\varphi$ inversely proportional to $\\varphi^n$.
Field emission electron source
Zettl, Alexander Karlwalter (Kensington, CA); Cohen, Marvin Lou (Berkeley, CA)
2000-01-01T23:59:59.000Z
A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.
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.
A general perspective on time observables
Bryan W. Roberts
2014-04-19T23:59:59.000Z
I propose a general geometric framework in which to discuss the existence of time observables. This frameworks allows one to describe a local sense in which time observables always exist, and a global sense in which they can sometimes exist subject to a restriction on the vector fields that they generate. Pauli's prohibition on quantum time observables is derived as a corollary to this result. I will then discuss how time observables can be regained in modest extensions of quantum theory beyond its standard formulation.
Environmental education: A time of change, a time for change Matt Keene a,
Blumstein, Daniel T.
Environmental education: A time of change, a time for change§ Matt Keene a, *, Daniel T. Blumstein b,1 a United States Environmental Protection Agency, 1200 Pennsylvania Avenue, NW (1807T) Washington, 621 Young Drive South, Los Angeles, CA 90095-1606, United States The field of environmental education
Bulk from Bi-locals in Thermo Field CFT
Jevicki, Antal
2015-01-01T23:59:59.000Z
We study the Large $N$ dynamics of the $O(N)$ field theory in the Thermo field approach. Concentrating on the singlet bi-local space within the systematic $1/N$ framework of collective field theory we discuss the emergent bulk space-time and construct the associated (Higher spin) fields. We note the presence of `evanescent' modes in this construction and also the mixing of spins at finite temperature.
Bulk from Bi-locals in Thermo Field CFT
Antal Jevicki; Junggi Yoon
2015-03-29T23:59:59.000Z
We study the Large $N$ dynamics of the $O(N)$ field theory in the Thermo field approach. Concentrating on the singlet bi-local space within the systematic $1/N$ framework of collective field theory we discuss the emergent bulk space-time and construct the associated (Higher spin) fields. We note the presence of `evanescent' modes in this construction and also the mixing of spins at finite temperature.
Constructive Quantum Field Theory
Giovanni Gallavotti
2005-10-04T23:59:59.000Z
A review of the renormalization group approach to the proof of non perturbative ultraviolet stability in scalar field theories in dimension d=2,3.
Lane, Michael
2013-06-28T23:59:59.000Z
Map of field observations including depressions, springs, evidence of former springs, travertine terraces and vegetation patterns. Map also contains interpretation of possible spring alignments.
H. C. Potter
2008-12-16T23:59:59.000Z
Gauge transformations are potential transformations that leave only specific Maxwell fields invariant. To reveal more, I develop Lorenz field equations with full Maxwell form for nongauge, sans gauge function, transformations yielding mixed, superposed retarded and outgoing, potentials. The form invariant Lorenz condition is then a charge conservation equivalent. This allows me to define three transformation classes that screen for Lorenz relevance. The nongauge Lorentz conditions add polarization fields which support emergent, light-like rays that convey energy on charge conserving phase points. These localized rays escape discovery in modern Maxwell fields where the polarizations are suppressed by gauge transformations.
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Lane, Michael
Map of field observations including depressions, springs, evidence of former springs, travertine terraces and vegetation patterns. Map also contains interpretation of possible spring alignments.
Field emission chemical sensor
Panitz, J.A.
1983-11-22T23:59:59.000Z
A field emission chemical sensor for specific detection of a chemical entity in a sample includes a closed chamber enclosing two field emission electrode sets, each field emission electrode set comprising (a) an electron emitter electrode from which field emission electrons can be emitted when an effective voltage is connected to the electrode set; and (b) a collector electrode which will capture said electrons emitted from said emitter electrode. One of the electrode sets is passive to the chemical entity and the other is active thereto and has an active emitter electrode which will bind the chemical entity when contacted therewith.
Timing the Parkes Multibeam Pulsars
R. N. Manchester; A. G. Lyne; F. Camilo; V. M. Kaspi; I. H. Stairs; F. Crawford; D. J. Morris; J. F. Bell; N. D'Amico
1999-11-17T23:59:59.000Z
Measurement of accurate positions, pulse periods and period derivatives is an essential follow-up to any pulsar survey. The procedures being used to obtain timing parameters for the pulsars discovered in the Parkes multibeam pulsar survey are described. Completed solutions have been obtained so far for about 80 pulsars. They show that the survey is preferentially finding pulsars with higher than average surface dipole magnetic fields. Eight pulsars have been shown to be members of binary systems and some of the more interesting results relating to these are presented.
Time evolution of cascade decay
Daniel Boyanovsky; Louis Lello
2014-06-25T23:59:59.000Z
We study non-perturbatively the time evolution of cascade decay for generic fields $\\pi \\rightarrow \\phi_1\\phi_2\\rightarrow \\phi_2\\chi_1\\chi_2$ and obtain the time dependence of amplitudes and populations for the resonant and final states. We analyze in detail the different time scales and the manifestation of unitary time evolution in the dynamics of production and decay of resonant intermediate and final states. The probability of occupation (population) "flows" as a function of time from the initial to the final states. When the decay width of the parent particle $\\Gamma_\\pi$ is much larger than that of the intermediate resonant state $\\Gamma_{\\phi_1}$ there is a "bottleneck" in the flow, the population of resonant states builds up to a maximum at $t^* = \\ln[\\Gamma_\\pi/\\Gamma_{\\phi_1}]/(\\Gamma_\\pi-\\Gamma_{\\phi_1})$ nearly saturating unitarity and decays to the final state on the longer time scale $1/\\Gamma_{\\phi_1}$. As a consequence of the wide separation of time scales in this case the cascade decay can be interpreted as evolving sequentially $\\pi \\rightarrow \\phi_1\\phi_2; ~ \\phi_1\\phi_2\\rightarrow \\phi_2\\chi_1\\chi_2$. In the opposite limit the population of resonances ($\\phi_1$) does not build up substantially and the cascade decay proceeds almost directly from the initial parent to the final state without resulting in a large amplitude of the resonant state. An alternative but equivalent non-perturbative method useful in cosmology is presented. Possible phenomenological implications for heavy sterile neutrinos as resonant states and consequences of quantum entanglement and correlations in the final state are discussed.
On Time. 6b: Quantum Mechanical Time
C. K. Raju
2008-08-09T23:59:59.000Z
The existence of small amounts of advanced radiation, or a tilt in the arrow of time, makes the basic equations of physics mixed-type functional differential equations. The novel features of such equations point to a microphysical structure of time. This corresponds to a change of logic at the microphysical level. We show that the resulting logic is a quantum logic. This provides a natural and rigorous explanation of quantum interference. This structured-time interpretation of quantum mechanics is briefly compared with various other interpretations of q.m.
Nakano, M; Kida, S; Masutani, Y; Shiraki, T; Yamamoto, K; Shiraishi, K; Nakagawa, K; Haga, A [University of Tokyo Hospital, Bunkyo-ku, Tokyo (Japan)
2014-06-01T23:59:59.000Z
Purpose: In the previous study, we developed time-ordered fourdimensional (4D) cone-beam CT (CBCT) technique to visualize nonperiodic organ motion, such as peristaltic motion of gastrointestinal organs and adjacent area, using half-scan reconstruction method. One important obstacle was that truncation of projection was caused by asymmetric location of flat-panel detector (FPD) in order to cover whole abdomen or pelvis in one rotation. In this study, we propose image mosaicing to extend projection data to make possible to reconstruct full field-of-view (FOV) image using half-scan reconstruction. Methods: The projections of prostate cancer patients were acquired using the X-ray Volume Imaging system (XVI, version 4.5) on Synergy linear accelerator system (Elekta, UK). The XVI system has three options of FOV, S, M and L, and M FOV was chosen for pelvic CBCT acquisition, with a FPD panel 11.5 cm offset. The method to produce extended projections consists of three main steps: First, normal three-dimensional (3D) reconstruction which contains whole pelvis was implemented using real projections. Second, virtual projections were produced by reprojection process of the reconstructed 3D image. Third, real and virtual projections in each angle were combined into one extended mosaic projection. Then, 4D CBCT images were reconstructed using our inhouse reconstruction software based on Feldkamp, Davis and Kress algorithm. The angular range of each reconstruction phase in the 4D reconstruction was 180 degrees, and the range moved as time progressed. Results: Projection data were successfully extended without discontinuous boundary between real and virtual projections. Using mosaic projections, 4D CBCT image sets were reconstructed without artifacts caused by the truncation, and thus, whole pelvis was clearly visible. Conclusion: The present method provides extended projections which contain whole pelvis. The presented reconstruction method also enables time-ordered 4D CBCT reconstruction of organs with non-periodic motion with full FOV without projection-truncation artifacts. This work was partly supported by the JSPS Core-to-Core Program(No. 23003). This work was partly supported by JSPS KAKENHI 24234567.
221B Lecture Notes Quantum Field Theory III (Radiation Field)
Murayama, Hitoshi
221B Lecture Notes Quantum Field Theory III (Radiation Field) 1 Quantization of Radiation Field was quantized: photons. Now that we have gone through quantization of a classical field (Schr¨odinger field so far), we can proceed to quantize the Maxwell field. The basic idea is pretty much the same, except
221B Lecture Notes Quantum Field Theory IV (Radiation Field)
Murayama, Hitoshi
221B Lecture Notes Quantum Field Theory IV (Radiation Field) 1 Quantization of Radiation Field was quantized: photons. Now that we have gone through quantization of a classical field (Schr¨odinger field so far), we can proceed to quantize the Maxwell field. The basic idea is pretty much the same, except
Magnetic Fields Analogous to electric field, a magnet
Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University
Magnetic Fields Analogous to electric field, a magnet produces a magnetic field, B Set up a B field two ways: Moving electrically charged particles Current in a wire Intrinsic magnetic field Basic) Opposite magnetic poles attract like magnetic poles repel #12;Like the electric field lines
Peter G. O. Freund
2010-08-24T23:59:59.000Z
Erik Verlinde's proposal of the emergence of the gravitational force as an entropic force is extended to abelian and non-abelian gauge fields and to matter fields. This suggests a picture with no fundamental forces or forms of matter whatsoever.
Topological quantum field theories
Albert Schwarz
2000-11-29T23:59:59.000Z
Following my plenary lecture on ICMP2000 I review my results concerning two closely related topics: topological quantum field theories and the problem of quantization of gauge theories. I start with old results (first examples of topological quantum field theories were constructed in my papers in late seventies) and I come to some new results, that were not published yet.
Scalar Field Inhomogeneous Cosmologies
A. Feinstein; J. Ibáñez; P. Labraga
1995-11-24T23:59:59.000Z
Some exact solutions for the Einstein field equations corresponding to inhomogeneous $G_2$ cosmologies with an exponential-potential scalar field which generalize solutions obtained previously are considered. Several particular cases are studied and the properties related to generalized inflation and asymptotic behaviour of the models are discussed.
Heel effect adaptive flat field correction of digital x-ray detectors
Yu, Yongjian [X-ray Products, Varian Medical Systems Inc., Liverpool, New York 13088 (United States)] [X-ray Products, Varian Medical Systems Inc., Liverpool, New York 13088 (United States); Wang, Jue [Department of Mathematics, Union College, Schenectady, New York 12308 (United States)] [Department of Mathematics, Union College, Schenectady, New York 12308 (United States)
2013-08-15T23:59:59.000Z
Purpose: Anode heel effect renders large-scale background nonuniformities in digital radiographs. Conventional offset/gain calibration is performed at mono source-to-image distance (SID), and disregards the SID-dependent characteristic of heel effect. It results in a residual nonuniform background in the corrected radiographs when the SID settings for calibration and correction differ. In this work, the authors develop a robust and efficient computational method for digital x-ray detector gain correction adapted to SID-variant heel effect, without resorting to physical filters, phantoms, complicated heel effect models, or multiple-SID calibration and interpolation.Methods: The authors present the Duo-SID projection correction method. In our approach, conventional offset/gain calibrations are performed only twice, at the minimum and maximum SIDs of the system in typical clinical use. A fast iterative separation algorithm is devised to extract the detector gain and basis heel patterns from the min/max SID calibrations. The resultant detector gain is independent of SID, while the basis heel patterns are parameterized by the min- and max-SID. The heel pattern at any SID is obtained from the min-SID basis heel pattern via projection imaging principles. The system gain desired at a specific acquisition SID is then constructed using the projected heel pattern and detector gain map.Results: The method was evaluated for flat field and anatomical phantom image corrections. It demonstrated promising improvements over interpolation and conventional gain calibration/correction methods, lowering their correction errors by approximately 70% and 80%, respectively. The separation algorithm was able to extract the detector gain and heel patterns with less than 2% error, and the Duo-SID corrected images showed perceptually appealing uniform background across the detector.Conclusions: The Duo-SID correction method has substantially improved on conventional offset/gain corrections for digital x-ray imaging in an SID-variant environment. The technique is relatively simple, and can be easily incorporated into multiple-point gain calibration/correction techniques. It offers a potentially valuable tool for preprocessing digital x-ray images to boost image quality of mammography, chest and cardiac radiography, as well as automated computer aided diagnostic radiology.
Scattering Polarization in the Presence of Magnetic and Electric Fields
Yee Yee Oo; M. Sampoorna; K. N. Nagendra; Sharath Ananthamurthy; G. Ramachandran
2007-02-12T23:59:59.000Z
The polarization of radiation by scattering on an atom embedded in combined external quadrupole electric and uniform magnetic fields is studied theoretically. Limiting cases of scattering under Zeeman effect and Hanle effect in weak magnetic fields are discussed. The theory is general enough to handle scattering in intermediate magnetic fields (Hanle-Zeeman effect) and for arbitrary orientation of magnetic field. The quadrupolar electric field produces asymmetric line shifts and causes interesting level-crossing phenomena either in the absence of an ambient magnetic field or in its presence. It is shown that the quadrupolar electric field produces an additional depolarization in the $Q/I$ profiles and rotation of the plane of polarization in the $U/I$ profile over and above that arising from magnetic field itself. This characteristic may have a diagnostic potential to detect steady state and time varying electric fields that surround radiating atoms in Solar atmospheric layers.
Encoding field theories into gravities
Aoki, Sinya; Onogi, Tetsuya
2015-01-01T23:59:59.000Z
We propose a method, which encodes the information of a $d$ dimensional quantum field theory into a $d+1$ dimensional gravity in the $1/N$ expansion. We first construct a $d+1$ dimensional field theory from the $d$ dimensional one via the gradient flow equation, whose flow time $t$ represents the energy scale of the system such that $t\\rightarrow 0$ corresponds to the ultra-violet (UV) while $t\\rightarrow\\infty$ to the infra-red (IR). We then define the induced metric from $d+1$ dimensional field operators. We show that the metric defined in this way becomes classical in the large $N$ limit, in a sense that quantum fluctuations of the metric are suppressed as $1/N$ due to the large $N$ factorization property. As a concrete example, we apply our method to the O(N) non-linear $\\sigma$ model in two dimensions. We calculate the induced metric in three dimensions, which is shown to describe De Sitter (dS) or Anti De Sitter (AdS) space in the massless limit, where the mass is dynamically generated in the O(N) non-l...
TIME-RESOLVED VIBRATIONAL SPECTROSCOPY
Andrei Tokmakoff, MIT (Conference Chair) [Conference Chair; Paul Champion, Northeastern University; Edwin J. Heilweil, NIST; Keith A. Nelson, MIT; Larry Ziegler, Boston University
2009-05-14T23:59:59.000Z
This document contains the Proceedings from the 14th International Conference on Time-Resolved Vibrational Spectroscopy, which was held in Meredith, NH from May 9-14, 2009. The study of molecular dynamics in chemical reaction and biological processes using time-resolved spectroscopy plays an important role in our understanding of energy conversion, storage, and utilization problems. Fundamental studies of chemical reactivity, molecular rearrangements, and charge transport are broadly supported by the DOEÃ¢Â?Â?s Office of Science because of their role in the development of alternative energy sources, the understanding of biological energy conversion processes, the efficient utilization of existing energy resources, and the mitigation of reactive intermediates in radiation chemistry. In addition, time-resolved spectroscopy is central to all five of DOEÃ¢Â?Â?s grand challenges for fundamental energy science. The Time-Resolved Vibrational Spectroscopy conference is organized biennially to bring the leaders in this field from around the globe together with young scientists to discuss the most recent scientific and technological advances. The latest technology in ultrafast infrared, Raman, and terahertz spectroscopy and the scientific advances that these methods enable were covered. Particular emphasis was placed on new experimental methods used to probe molecular dynamics in liquids, solids, interfaces, nanostructured materials, and biomolecules.
Yet another time about time - Part I
Plamen L. Simeonov
2015-08-29T23:59:59.000Z
This paper presents yet another personal reflection on one the most important concepts in both science and the humanities: time. This elusive notion has been not only bothering philosophers since Plato and Aristotle. It goes throughout human history embracing all analytical and creative (anthropocentric) disciplines. Time has been a central theme in physical and life sciences, philosophy, psychology, music, art and many more. This theme is known with a vast body of knowledge across different theories and categories. What has been explored concerns its nature (rational, irrational, arational), appearances/qualia, degrees, dimensions and scales of conceptualization (internal, external, fractal, discrete, continuous, mechanical, quantum, local, global, etc.). Of particular interest have been parameters of time such as duration ranges, resolutions, modes (present, now, past, future), varieties of tenses (e.g. present perfect, present progressive, etc.) and some intuitive, but also fancy phenomenological characteristics such as arrow, stream, texture, width, depth, density, even scent. Perhaps the most distinct characteristic of this fundamental concept is the absolute time constituting the flow of consciousness according to Husserl, the reflection of pure (human) nature without having the distinction between exo and endo. This essay is a personal reflection upon the meaning of time in modern physics and phenomenological philosophy.
Jansson, Ronnie; Farrar, Glennys R. [Center for Cosmology and Particle Physics, Department of Physics, New York University, New York, NY 10003 (United States)
2012-12-10T23:59:59.000Z
With this Letter, we complete our model of the Galactic magnetic field (GMF), by using the WMAP7 22 GHz total synchrotron intensity map and our earlier results to obtain a 13-parameter model of the Galactic random field, and to determine the strength of the striated random field. In combination with our 22-parameter description of the regular GMF, we obtain a very good fit to more than 40,000 extragalactic Faraday rotation measures and the WMAP7 22 GHz polarized and total intensity synchrotron emission maps. The data call for a striated component to the random field whose orientation is aligned with the regular field, having zero mean and rms strength Almost-Equal-To 20% larger than the regular field. A noteworthy feature of the new model is that the regular field has a significant out-of-plane component, which had not been considered earlier. The new GMF model gives a much better description of the totality of data than previous models in the literature.
Lightweight Time Modeling in Timed Creol
Bjørk, Joakim; Owe, Olaf; Schlatte, Rudolf; 10.4204/EPTCS.36.4
2010-01-01T23:59:59.000Z
Creol is an object-oriented modeling language in which inherently concurrent objects exchange asynchronous method calls. The operational semantics of Creol is written in an actor-based style, formulated in rewriting logic. The operational semantics yields a language interpreter in the Maude system, which can be used to analyze models. Recently, Creol has been applied to the modeling of systems with radio communication, such as sensor systems. With radio communication, messages expire and, if sent simultaneously, they may collide in the air. In order to capture these and other properties of distributed systems, we extended Creol's operational semantics with a notion of time. We exploit the framework of a language interpreter to use a lightweight notion of time, in contrast to that needed for a general purpose specification language. This paper presents a timed extension of Creol, including the semantics and the implementation strategy, and discusses its properties using an extended example. The approach can be...
Cosmology of Bifundamental Fields
Tanmay Vachaspati
2008-12-17T23:59:59.000Z
If a field theory contains gauged, non-Abelian, bi-fundamental fields i.e. fields that are charged under two separate non-Abelian gauge groups, the transition from a deconfined phase to a hadronic phase may be frustrated. Similar frustration may occur in non-Abelian gauge models containing matter only in higher dimensional representations e.g. models with pure glue, or if ordinary quarks are confined by two flux tubes, as implied in the triangular configuration of baryons within QCD. In a cosmological setting, such models can lead to the formation of a web of confining electric flux tubes that can potentially have observational signatures.
Time Asymmetric Quantum Physics
A. Bohm
1999-02-26T23:59:59.000Z
Mathematical and phenomenological arguments in favor of asymmetric time evolution of micro-physical states are presented.
viii Contents. Three Field Theory. 87—89. 90—95. 96—97. 98—107. 108—114. 115—121. De?nition and examples of ?eld structure 67. Vector spaces, bases ...
Manager, Carlsbad Field Office
Broader source: Energy.gov [DOE]
The U.S. Department of Energy (DOE), Office of Environmental Management (EM), Carlsbad Field Office (CBFO) is seeking a highly experienced and motivated executive-minded individual to fill its...
Duble, Richard L.
1995-07-31T23:59:59.000Z
Coaches are often more concerned with injuries, personnel problems and opponents than with the condition of the turf on their playing fields. This publication discusses management strategies, including mowing, fertilizing, watering and renovating...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
please contact Mr. Anthony Stone at (575) 234-7475. flose R. FrManager Carlsbad Field Office Enclosure cc: wenclosure K. Roberts, NMED *ED R. Maestas, NMED ED S. Holmes, NMED ED...
2010-08-05T23:59:59.000Z
dfield8 Direction Fields. • The routine dfield8 is already loaded on all ITaP machines as standard software. To access MAtlAB from any ITaP machine: Start
Measuring Oscillatory Velocity Fields Due to Swimming Algae
Guasto, Jeffrey S; Gollub, J P
2010-01-01T23:59:59.000Z
In this fluid dynamics video, we present the first time-resolved measurements of the oscillatory velocity field induced by swimming unicellular microorganisms. Confinement of the green alga C. reinhardtii in stabilized thin liquid films allows simultaneous tracking of cells and tracer particles. The measured velocity field reveals complex time-dependent flow structures, and scales inversely with distance. The instantaneous mechanical power generated by the cells is measured from the velocity fields and peaks at 15 fW. The dissipation per cycle is more than four times what steady swimming would require.
Oldham, D.W.; Smosna, R.A. [West Virginia Univ., Morgantown, WV (United States)
1996-06-01T23:59:59.000Z
Subsurface analysis of Permian salt and related strata in the shallow Niobrara gas area on the eastern flank of the Denver basin reveals that the location of faulted anticlines which produce gas from porous chalk is related to the occurrence of six Nippewalla Group (Leonardian) salt zones. Salt distribution is controlled by the configuration of evaporate basins during the Leonardian, truncation at a sub-Jurassic unconformity (which has completely removed Guadalupian salts), and post-Jurassic subsurface dissolution. Significant dissolution took place in response to Laramide orogeny and subsequent eastward regional groundwater flow within the Lyons (Cedar Hills) Sandstone aquifer. Initially, dissolution occurred along a regional facies change from sandstone to salt. Solution collapse allowed for cross-formational flow and removal of younger salts. Shallow Niobrara gas fields are situated above salt outliers or along regionally updip salt edges. No significant Niobrara production exists in areas where salt is absent. Structural relief across fields is related to Leonardian thickness variations, rather than subsalt offset. Seismic data reveal abrupt Leonardian thinning at the regionally updip limit of Eckley field, which has produced over 33 BCFG. Thickness of residual salt may be important in controlling the amount of gas trapped within the Niobrara. Where thick salts are preserved, structural relief is greater, the gas-water transition zone is thicker, and gas saturation is higher at the crests of faulted anticlines.
Continuous time-of-flight ion mass spectrometer
Funsten, Herbert O.; Feldman, William C.
2004-10-19T23:59:59.000Z
A continuous time-of-flight mass spectrometer having an evacuated enclosure with means for generating an electric field located in the evacuated enclosure and means for injecting a sample material into the electric field. A source of continuous ionizing radiation injects ionizing radiation into the electric field to ionize atoms or molecules of the sample material, and timing means determine the time elapsed between arrival of a secondary electron out of said ionized atoms or molecules at a first predetermined location and arrival of a sample ion out of said ionized atoms or molecules at a second predetermined location.
Quasi light fields: extending the light field to coherent radiation
Wornell, Gregory W.
Quasi light fields: extending the light field to coherent radiation Anthony Accardi1,2 and Gregory light field, and for coherent radiation using electromagnetic field theory. We present a model of coherent image formation that strikes a balance between the utility of the light field
T. Matolcsi; P. Van
2006-10-23T23:59:59.000Z
A four dimensional treatment of nonrelativistic space-time gives a natural frame to deal with objective time derivatives. In this framework some well known objective time derivatives of continuum mechanics appear as Lie-derivatives. Their coordinatized forms depends on the tensorial properties of the relevant physical quantities. We calculate the particular forms of objective time derivatives for scalars, vectors, covectors and different second order tensors from the point of view of a rotating observer. The relation of substantial, material and objective time derivatives is treated.
S. Pireaux
2007-03-23T23:59:59.000Z
The LISA mission is a space interferometer aiming at the detection of gravitational waves in the [$10^{-4}$,$10^{-1}$] Hz frequency band. In order to reach the gravitational wave detection level, a Time Delay Interferometry (TDI) method must be applied to get rid of (most of) the laser frequency noise and optical bench noise. This TDI analysis is carried out in terms of the coordinate time corresponding to the Barycentric Coordinate Reference System (BCRS), TCB, whereas the data at each of the three LISA stations is recorded in terms of each station proper time. We provide here the required proper time versus BCRS time transformation. We show that the difference in rate of station proper time versus TCB is of the order of $5 10^{-8}$. The difference between station proper times and TCB exhibits an oscillatory trend with a maximum amplitude of about $10^{-3}$ s.
Coherent hybrid electromagnetic field imaging
Cooke, Bradly J. (Jemez Springs, NM); Guenther, David C. (Los Alamos, NM)
2008-08-26T23:59:59.000Z
An apparatus and corresponding method for coherent hybrid electromagnetic field imaging of a target, where an energy source is used to generate a propagating electromagnetic beam, an electromagnetic beam splitting means to split the beam into two or more coherently matched beams of about equal amplitude, and where the spatial and temporal self-coherence between each two or more coherently matched beams is preserved. Two or more differential modulation means are employed to modulate each two or more coherently matched beams with a time-varying polarization, frequency, phase, and amplitude signal. An electromagnetic beam combining means is used to coherently combine said two or more coherently matched beams into a coherent electromagnetic beam. One or more electromagnetic beam controlling means are used for collimating, guiding, or focusing the coherent electromagnetic beam. One or more apertures are used for transmitting and receiving the coherent electromagnetic beam to and from the target. A receiver is used that is capable of square-law detection of the coherent electromagnetic beam. A waveform generator is used that is capable of generation and control of time-varying polarization, frequency, phase, or amplitude modulation waveforms and sequences. A means of synchronizing time varying waveform is used between the energy source and the receiver. Finally, a means of displaying the images created by the interaction of the coherent electromagnetic beam with target is employed.
Nonlinear Spinor Fields in Bianchi type-$VI_0$ spacetime
Bijan Saha
2015-04-15T23:59:59.000Z
Within the scope of Bianchi type-$VI_0$ space time we study the role of spinor field on the evolution of the Universe. It is found that the presence of nontrivial non-diagonal components of energy-momentum tensor of the spinor field plays vital role on the evolution of the Universe. As a result of their mutual influence the invariants constructed from the bilinear forms of the spinor field become trivial, thus giving rise to a massless and linear spinor field Lagrangian. This result shows that the spinor field is highly sensitive to the gravitational one.
Particle acceleration by fluctuating electric fields at a magnetic field null point
P. Petkaki; A. L. MacKinnon
2007-07-09T23:59:59.000Z
Particle acceleration consequences from fluctuating electric fields superposed on an X-type magnetic field in collisionless solar plasma are studied. Such a system is chosen to mimic generic features of dynamic reconnection, or the reconnective dissipation of a linear disturbance. We explore numerically the consequences for charged particle distributions of fluctuating electric fields superposed on an X-type magnetic field. Particle distributions are obtained by numerically integrating individual charged particle orbits when a time varying electric field is superimposed on a static X-type neutral point. This configuration represents the effects of the passage of a generic MHD disturbance through such a system. Different frequencies of the electric field are used, representing different possible types of wave. The electric field reduces with increasing distance from the X-type neutral point as in linear dynamic magnetic reconnection. The resulting particle distributions have properties that depend on the amplitude and frequency of the electric field. In many cases a bimodal form is found. Depending on the timescale for variation of the electric field, electrons and ions may be accelerated to different degrees and often have energy distributions of different forms. Protons are accelerated to $\\gamma$-ray producing energies and electrons to and above hard X-ray producing energies in timescales of 1 second. The acceleration mechanism is possibly important for solar flares and solar noise storms but is also applicable to all collisionless plasmas.
Gravitational Field of the Early Universe: I.Non-linear Scalar Field as the Source
S. V. Chervon
1997-06-10T23:59:59.000Z
In this review article we consider three most important sources of the gravitational field of the Early Universe: self-interacting scalar field, chiral field and gauge field. The correspondence between all of them are pointed out. More attention is payed to nonlinear scalar field source of gravity. The progress in finding the exact solutions in inflationary universe is reviewed. The basic idea of `fine turning of the potential' method is discussed and computational background is presented in details. A set of new exact solutions for standard inflationary model and conformally-flat space-times are obtained. Special attention payed to relations between `fine turning of the potential' and Barrow's approaches. As the example of a synthesis of both methods new exact solution is obtained.
Relaxation times calculated from angular deflections
E. Athanassoula; Ch. L. Vozikis; J. C. Lambert
2001-08-21T23:59:59.000Z
In this paper we measure the two-body relaxation time from the angular deflection of test particles launched in a rigid configuration of field particles. We find that centrally concentrated configurations have relaxation times that can be shorter than those of the corresponding homogeneous distributions by an order of magnitude or more. For homogeneous distributions we confirm that the relaxation time is proportional to the number of particles. On the other hand centrally concentrated configurations have a much shallower dependence, particularly for small values of the softening. The relaxation time increases with the inter-particle velocities and with softening. The latter dependence is not very strong, of the order of a factor of two when the softening is increased by an order of magnitude. Finally we show that relaxation times are the same on GRAPE-3 and GRAPE-4, dedicated computer boards with limited and high precision respectively.
A new attitude determination approach using split field of view star camera
Singla, Puneet
2002-01-01T23:59:59.000Z
the attitude, principal point offset and the focal length with the help of two Kalman filters working in tandem. Occasionally, we find that the correlation of attitude and principal point offset can make this algorithm somewhat unstable. A novel algorithm has...
System Design of a Wide Bandwidth Continuous-Time Sigma-Delta Modulator
Periasamy, Vijayaramalingam
2010-07-14T23:59:59.000Z
.................................................................... 39 4.3.2 Offset voltage.......................................................................... 39 4.4 Clock jitter ......................................................................................... 41 4.4.1 Modeling jitter... with peaking ................................................................. 37 23 Monte-Carlo simulations for offset voltage of comparators ...................... 40 24 Effect of clock jitter on different feedback DAC pulses...
Intrinsic Time Quantum Geometrodynamics
Ita, Eyo Eyo; Yu, Hoi-Lai
2015-01-01T23:59:59.000Z
Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of time' point in the same direction. Ricci scalar potential corresponding to Einstein's General Relativity emerges as a zero-point energy contribution. A new set of fundamental canonical commutation relations without Planck's constant emerges from the unification of Gravitation and Quantum Mechanics.
White, Lynn
2000-06-27T23:59:59.000Z
, you expect unused time to come around again, so that when the same opportunities appear you will be wiser about how to use it. Consider how your cultural background af_fects the w ay you plan and manage time. W *Both cited in Bauer, J. It?s Time.... Effective time management means decid- ing which activity should be done from all the possibilities available, and then doing it. It is a matter of setting priorities. Deciding which jobs are most important and working on those may be better than doing less...
Intrinsic Time Quantum Geometrodynamics
Eyo Eyo Ita III; Chopin Soo; Hoi-Lai Yu
2015-02-06T23:59:59.000Z
Quantum Geometrodynamics with intrinsic time development and momentric variables is presented. An underlying SU(3) group structure at each spatial point regulates the theory. The intrinsic time behavior of the theory is analyzed, together with its ground state and primordial quantum fluctuations. Cotton-York potential dominates at early times when the universe was small; the ground state naturally resolves Penrose's Weyl Curvature Hypothesis, and thermodynamic and gravitational `arrows of time' point in the same direction. Ricci scalar potential corresponding to Einstein's General Relativity emerges as a zero-point energy contribution. A new set of fundamental commutation relations without Planck's constant emerges from the unification of Gravitation and Quantum Mechanics.
High-frequency electric field measurement using a toroidal antenna
Lee, Ki Ha (Lafayette, CA)
2002-01-01T23:59:59.000Z
A simple and compact method and apparatus for detecting high frequency electric fields, particularly in the frequency range of 1 MHz to 100 MHz, uses a compact toroidal antenna. For typical geophysical applications the sensor will be used to detect electric fields for a wide range of spectrum starting from about 1 MHz, in particular in the frequency range between 1 to 100 MHz, to detect small objects in the upper few meters of the ground. Time-varying magnetic fields associated with time-varying electric fields induce an emf (voltage) in a toroidal coil. The electric field at the center of (and perpendicular to the plane of) the toroid is shown to be linearly related to this induced voltage. By measuring the voltage across a toroidal coil one can easily and accurately determine the electric field.
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.
Kristan Jensen
2014-12-24T23:59:59.000Z
We initiate a systematic study of `t Hooft anomalies in Galilean field theories, focusing on two questions therein. In the first, we consider the non-relativistic theories obtained from a discrete light-cone quantization (DLCQ) of a relativistic theory with flavor or gravitational anomalies. We find that these anomalies survive the DLCQ, becoming mixed flavor/boost or gravitational/boost anomalies. We also classify the pure Weyl anomalies of Schr\\"odinger theories, which are Galilean conformal field theories (CFTs) with $z=2$. There are no pure Weyl anomalies in even spacetime dimension, and the lowest-derivative anomalies in odd dimension are in one-to-one correspondence with those of a relativistic CFT in one dimension higher. These results classify many of the anomalies that arise in the field theories dual to string theory on Schr\\"odinger spacetimes.
Sampayan, S.E.
1998-03-03T23:59:59.000Z
A hybrid emitter exploits the electric field created by a rapidly depoled ferroelectric material. Combining the emission properties of a planar thin film diamond emitter with a ferroelectric alleviates the present technological problems associated with both types of emitters and provides a robust, extremely long life, high current density cathode of the type required by emerging microwave power generation, accelerator technology and display applications. This new hybrid emitter is easy to fabricate and not susceptible to the same failures which plague microstructure field emitter technology. Local electrode geometries and electric field are determined independently from those for optimum transport and brightness preservation. Due to the large amount of surface charge created on the ferroelectric, the emitted electrons have significant energy, thus eliminating the requirement for specialized phosphors in emissive flat-panel displays. 11 figs.
Sampayan, Stephen E. (Manteca, CA)
1998-01-01T23:59:59.000Z
A hybrid emitter exploits the electric field created by a rapidly depoled ferroelectric material. Combining the emission properties of a planar thin film diamond emitter with a ferroelectric alleviates the present technological problems associated with both types of emitters and provides a robust, extremely long life, high current density cathode of the type required by emerging microwave power generation, accelerator technology and display applications. This new hybrid emitter is easy to fabricate and not susceptible to the same failures which plague microstructure field emitter technology. Local electrode geometries and electric field are determined independently from those for optimum transport and brightness preservation. Due to the large amount of surface charge created on the ferroelectric, the emitted electrons have significant energy, thus eliminating the requirement for specialized phosphors in emissive flat-panel displays.
STATISTICAL MECHANICS AND FIELD THEORY
Samuel, S.A.
2010-01-01T23:59:59.000Z
York. K. Bardakci, Field Theory for Solitons, II, BerkeleyFart I Applications of Field Theory Methods to StatisticalStatistical Mechanics to Field Theory Chapter IV The Grand
Hamilton-Jacobi theory in k-cosymplectic field theories
M. de León; S. Vilariño
2013-04-11T23:59:59.000Z
In this paper we extend the geometric formalism of the Hamilton-Jacobi theory for time dependent Mechanics to the case of classical field theories in the k-cosymplectic framework.
Pulse homodyne field disturbance sensor
McEwan, T.E.
1997-10-28T23:59:59.000Z
A field disturbance sensor operates with relatively low power, provides an adjustable operating range, is not hypersensitive at close range, allows co-location of multiple sensors, and is inexpensive to manufacture. The sensor includes a transmitter that transmits a sequence of transmitted bursts of electromagnetic energy. The transmitter frequency is modulated at an intermediate frequency. The sequence of bursts has a burst repetition rate, and each burst has a burst width and comprises a number of cycles at a transmitter frequency. The sensor includes a receiver which receives electromagnetic energy at the transmitter frequency, and includes a mixer which mixes a transmitted burst with reflections of the same transmitted burst to produce an intermediate frequency signal. Circuitry, responsive to the intermediate frequency signal indicates disturbances in the sensor field. Because the mixer mixes the transmitted burst with reflections of the transmitted burst, the burst width defines the sensor range. The burst repetition rate is randomly or pseudo-randomly modulated so that bursts in the sequence of bursts have a phase which varies. A second range-defining mode transmits two radio frequency bursts, where the time spacing between the bursts defines the maximum range divided by two. 12 figs.
Pulse homodyne field disturbance sensor
McEwan, Thomas E. (Livermore, CA)
1997-01-01T23:59:59.000Z
A field disturbance sensor operates with relatively low power, provides an adjustable operating range, is not hypersensitive at close range, allows co-location of multiple sensors, and is inexpensive to manufacture. The sensor includes a transmitter that transmits a sequence of transmitted bursts of electromagnetic energy. The transmitter frequency is modulated at an intermediate frequency. The sequence of bursts has a burst repetition rate, and each burst has a burst width and comprises a number of cycles at a transmitter frequency. The sensor includes a receiver which receives electromagnetic energy at the transmitter frequency, and includes a mixer which mixes a transmitted burst with reflections of the same transmitted burst to produce an intermediate frequency signal. Circuitry, responsive to the intermediate frequency signal indicates disturbances in the sensor field. Because the mixer mixes the transmitted burst with reflections of the transmitted burst, the burst width defines the sensor range. The burst repetition rate is randomly or pseudo-randomly modulated so that bursts in the sequence of bursts have a phase which varies. A second range-defining mode transmits two radio frequency bursts, where the time spacing between the bursts defines the maximum range divided by two.
Developing Improved Travel Time Reliability Measures For Real-time
Bertini, Robert L.
reliability Use for prioritizing improvements Outline #12; 95th Percentile Travel Time Travel Time Index: mean travel time divided by free flow travel time Buffer Index: difference between 95th percentile travel time and mean travel time, divided by mean travel time Planning Time Index: 95th percentile
Decoupled Sampling for Real-Time Graphics Pipelines
Ragan-Kelley, Jonathan
2010-03-29T23:59:59.000Z
We propose decoupled sampling, an approach that decouples shading from visibility sampling in order to enable motion blur and depth-of-field at reduced cost. More generally, it enables extensions of modern real-time graphics ...
Washington Taylor
2000-04-19T23:59:59.000Z
This note focuses on the coupling of a type IIA D2-brane to a background B field. It is shown that the D0-brane charge arising from the integral over the D2-brane of the pullback of the B field is cancelled by bulk contributions, for a compact D2-brane wrapping a homotopically trivial cycle in space-time. In M-theory this cancellation is a straightforward consequence of momentum conservation. This result resolves a puzzle recently posed by Bachas, Douglas and Schweigert related to the quantization of R-R charges on stable spherical D2-branes on the group manifold SU(2).
Schwinger functions in noncommutative quantum field theory
Dorothea Bahns
2009-08-31T23:59:59.000Z
It is shown that the $n$-point functions of scalar massive free fields on the noncommutative Minkowski space are distributions which are boundary values of analytic functions. Contrary to what one might expect, this construction does not provide a connection to the popular traditional Euclidean approach to noncommutative field theory (unless the time variable is assumed to commute). Instead, one finds Schwinger functions with twistings involving only momenta that are on the mass-shell. This explains why renormalization in the traditional Euclidean noncommutative framework crudely differs from renormalization in the Minkowskian regime.
A. Boyarsky; P Gora
2007-05-07T23:59:59.000Z
We present a definition of time measurement based on high energy photons and the fundamental length scale, and show that, for macroscopic time, it is in accord with the Lorentz transformation of special relativity. To do this we define observer in a different way than in special relativity.
Why Field Reversed Configurations (FRC's)? Superior Reactor Potential
Washington at Seattle, University of
$r osin(t+) $ Rotating Magnetic Field (BRMF) Axial Magnetic Field (Baxial) Cylindrical Plasma Column (FRC Stays Off Wall. #12;RMF's, Existing FRC's and Plasma Ionization: An RMF can be used to drive current in an existing FRC. This has not been tried. There are penetration issues since the plasma is hot. On what time
Fresnel approximations for acoustic fields of rectangularly symmetric sources
Mast, T. Douglas
Fresnel approximations for acoustic fields of rectangularly symmetric sources T. Douglas Masta for determining the acoustic fields of rectangularly symmetric, baffled, time-harmonic sources under the Fresnel. The expressions presented are generalized to three different Fresnel approximations that correspond, respectively
The quantum field theory interpretation of quantum mechanics
Alberto C. de la Torre
2015-03-02T23:59:59.000Z
It is shown that adopting the \\emph{Quantum Field} ---extended entity in space-time build by dynamic appearance propagation and annihilation of virtual particles--- as the primary ontology the astonishing features of quantum mechanics can be rendered intuitive. This interpretation of quantum mechanics follows from the formalism of the most successful theory in physics: quantum field theory.
Noncommutative field theories: The noncommutative Chern-Simons model
Gomes, M.; Silva, A. J. da [Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318, 05315-970, Sao Paulo (Brazil)
2006-11-03T23:59:59.000Z
We present some results on the ultraviolet/infrared mixing for canonical field theory in three and four space-time dimensions. Special emphasis is given to the analysis of theories containing the Chern-Simons field and it is argued that for supersymmetric models the effect of the mixing is in general mild leading to consistent theories as far as renormalization is concerned.
Running of scalar spectral index in multi-field inflation
Jinn-Ouk Gong
2015-05-20T23:59:59.000Z
We compute the running of the scalar spectral index in general multi-field slow-roll inflation. By incorporating explicit momentum dependence at the moment of horizon crossing, we can find the running straightforwardly. At the same time, we can distinguish the contributions from the quasi de Sitter background and the super-horizon evolution of the field fluctuations.
OPTIMAL DEVELOPMENT PLANNING OF OFFSHORE OIL AND GAS FIELD
Grossmann, Ignacio E.
, well drilling schedule and production profiles of oil, water and gas in each time period. The model can and how many wells are to be drilled in those fields and in what order, which field to be connected, limitation on the number of wells that can be drilled each year due to availability of the drilling rigs
Twists of quantum groups and noncommutative field theory
P. P. Kulish
2006-06-07T23:59:59.000Z
The role of quantum universal enveloping algebras of symmetries in constructing a noncommutative geometry of space-time and corresponding field theory is discussed. It is shown that in the framework of the twist theory of quantum groups, the noncommutative (super) space-time defined by coordinates with Heisenberg commutation relations, is (super) Poincar\\'e invariant, as well as the corresponding field theory. Noncommutative parameters of global transformations are introduced.
Andrei Linde
2015-04-02T23:59:59.000Z
I describe a simple class of $\\alpha$-attractors, generalizing the single-field GL model of inflation in supergravity. The new class of models is defined for $0<\\alpha \\lesssim 1$, providing a good match to the present cosmological data. I also present a generalized version of these models which can describe not only inflation but also dark energy and supersymmetry breaking.
Algebraic Quantum Field Theory
Hans Halvorson; Michael Mueger
2006-02-14T23:59:59.000Z
Algebraic quantum field theory provides a general, mathematically precise description of the structure of quantum field theories, and then draws out consequences of this structure by means of various mathematical tools -- the theory of operator algebras, category theory, etc.. Given the rigor and generality of AQFT, it is a particularly apt tool for studying the foundations of QFT. This paper is a survey of AQFT, with an orientation towards foundational topics. In addition to covering the basics of the theory, we discuss issues related to nonlocality, the particle concept, the field concept, and inequivalent representations. We also provide a detailed account of the analysis of superselection rules by S. Doplicher, R. Haag, and J. E. Roberts (DHR); and we give an alternative proof of Doplicher and Roberts' reconstruction of fields and gauge group from the category of physical representations of the observable algebra. The latter is based on unpublished ideas due to Roberts and the abstract duality theorem for symmetric tensor *-categories, a self-contained proof of which is given in the appendix.
Sorghum Ergot - Field Identification
Krausz, Joseph P.
1997-07-21T23:59:59.000Z
stream_source_info pdf_835.pdf.txt stream_content_type text/plain stream_size 1934 Content-Encoding ISO-8859-1 stream_name pdf_835.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Sorghum Ergot Field Identif_ication...
Experimental quantum field theory
Bell, J S
1977-01-01T23:59:59.000Z
Presented here, is, in the opinion of the author, the essential minimum of quantum field theory that should be known to cultivated experimental particle physicists. The word experimental describes not only the audience aimed at but also the level of mathematical rigour aspired to. (0 refs).
The polarization field for pulsed Raman transitions
Shore, B.W.; Sacks, R.; Karr, T.
1987-05-15T23:59:59.000Z
This memo discusses the induced polarization field that occurs in the presence of Raman processes, and the propagation equations that result from this field. First the paper summarizes the relationship between the macroscopic polarization field and the microscopic dipole-moment expectation value. It summarizes expressions for the induced dipole moment that result from the adiabatic elimination of non-resonant molecular transitions, to produce an effective two-photon (Raman) Hamiltonian. Then it shows that the polarization field has a similar mode expansion to the electric field. Using this result the equations for pulse propagation of the electric field are described. These equations involve a generalized gain matrix and mode velocity, as well as a refractive index, each of which depends upon position and time. Finally the paper summarizes these results and exhibits succinctly the pulse propagation equations in the plane-wave slowly-varying envelope approximation. The equations presented here must be supplemented with excitation equations (or by steady-state results) for the molecules. The material presented here is a portion of a more extensive treatment of propagation to be presented separately.
Field/source duality in topological field theories
David Delphenich
2007-02-13T23:59:59.000Z
The relationship between the sources of physical fields and the fields themselves is investigated with regard to the coupling of topological information between them. A class of field theories that we call topological field theories is defined such that both the field and its source represent de Rham cocycles in varying dimensions over complementary subspaces and the coupling of one to the other is by way of an isomorphism of the those cohomology spaces, which we refer to as field/source duality. The deeper basis for such an isomorphism is investigated and the process is described for various elementary physical examples of topological field theories.
Martin, A.D.
1986-05-09T23:59:59.000Z
Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay provides a first output signal at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits latch the high resolution data to form a first synchronizing data set. A selected time interval has been preset to internal counters and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses count down the counters to generate an internal pulse delayed by an internal which is functionally related to the preset time interval. A second LCD corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD to generate a second set of synchronizing data which is complementary with the first set of synchronizing data for presentation to logic circuits. The logic circuits further delay the internal output signal with the internal pulses. The final delayed output signal thereafter enables the output pulse generator to produce the desired output pulse at the preset time delay interval following input of the trigger pulse.
Magnetic fields in Neutron Stars
Viganò, Daniele; Miralles, Juan A; Rea, Nanda
2015-01-01T23:59:59.000Z
Isolated neutron stars show a diversity in timing and spectral properties, which has historically led to a classification in different sub-classes. The magnetic field plays a key role in many aspects of the neutron star phenomenology: it regulates the braking torque responsible for their timing properties and, for magnetars, it provides the energy budget for the outburst activity and high quiescent luminosities (usually well above the rotational energy budget). We aim at unifying this observational variety by linking the results of the state-of-the-art 2D magneto-thermal simulations with observational data. The comparison between theory and observations allows to place two strong constraints on the physical properties of the inner crust. First, strong electrical currents must circulate in the crust, rather than in the star core. Second, the innermost part of the crust must be highly resistive, which is in principle in agreement with the presence of a novel phase of matter so-called nuclear pasta phase.
Dynamics of oscillating scalar field in thermal environment
Kyohei Mukaida; Kazunori Nakayama
2013-04-24T23:59:59.000Z
There often appear coherently oscillating scalar fields in particle physics motivated cosmological scenarios, which may have rich phenomenological consequences. Scalar fields should somehow interact with background thermal bath in order to decay into radiation at an appropriate epoch, but introducing some couplings to the scalar field makes the dynamics complicated. We investigate in detail the dynamics of a coherently oscillating scalar field, which has renormalizable couplings to another field interacting with thermal background. The scalar field dynamics and its resultant abundance are significantly modified by taking account of following effects : (1) thermal correction to the effective potential, (2) dissipation effect on the scalar field in thermal bath, (3) non-perturbative particle production events and (4) formation of non-topological solitons. There appear many time scales depending on the scalar mass, amplitude, couplings and the background temperature, which make the efficiencies of these effects non-trivial.
An observational test of magnetospheric field models at geosynchronous orbit
Thomsen, M.F.; Weiss, L.A.; McComas, D.J.; Moldwin, M.B.; Reeves, G.D.
1994-07-01T23:59:59.000Z
The configuration of the geomagnetic field is an indicator of the response of the magnetosphere to the solar wind input. A number of empirical magnetospheric field models are currently in use which estimate the magnetic field direction and magnitude at any point within the magnetosphere under a variety of conditions. Here, the global nature of the Tsyganenko 89 [Tsyganenko, 1989] magnetospheric magnetic field model is tested by comparison of the model-predicted field orientations with the field orientations derived simultaneously at two different locations in geosynchronous orbit from the axis of symmetry of the plasma electron distribution function (30 eV--40 keV). The results for the particular time interval studied are inconclusive because the Tsyganenko 89 model does not describe the field at one of the satellites well enough, but the procedure itself appears promising.
Tunneling time in attosecond experiments and time-energy uncertainty relation
Ossama Kullie
2015-07-24T23:59:59.000Z
In this work we present a theoretical model supported with a physical reasoning leading to a relation which performs an excellent estimation for the tunneling time in attosecond and strong field experiments, where we address the important case of the He-atom \\cite{Eckle:2008s,Eckle:2008}. Our tunneling time estimation is found by utilizing the time-energy uncertainty relation and represents a quantum clock. The tunneling time is also featured as the time of passage (at the exit of the tunnel) similarly to the Einstein's {\\it photon box Gedanken experiment}. Our work tackles an important study case for the theory of time in quantum mechanics and is very promising for the search for a (general) time operator in quantum mechanics. The work can be seen as a new fundamental step in dealing with the tunneling time in strong field and ultra-fast science, and is appealing for more elaborate treatments using quantum wave packet dynamics and especially for complex atoms and molecules.
BASHIR et al.: GAIT REPRESENTATION USING FLOW FIELDS 1 Gait Representation Using Flow Fields
Gong, Shaogang
the human body configuration (e.g. 2D/3D skeletons) and the model parameters estimated over time encode approaches such as Gait Energy Image (GEI) and Motion Silhouettes Image (MSI) capture only the motion inten unchanged freely in print or electronic forms. #12;2 BASHIR et al.: GAIT REPRESENTATION USING FLOW FIELDS
Quantum Field Theory in de Sitter Universe: Ambient Space Formalism
Mohammad Vahid Takook
2014-09-03T23:59:59.000Z
Quantum field theory in the $4$-dimensional de Sitter space-time is constructed on a unique Bunch-Davies vacuum state in the ambient space formalism in a rigorous mathematical framework. This work is based on the group representation theory and the analyticity of the complexified pseudo-Riemannian manifolds. The unitary irreducible representations of de Sitter group and their corresponding Hilbert spaces are reformulated in the ambient space formalism. Defining the creation and annihilation operators, quantum field operators and their corresponding analytic two-point functions for various spin fields ($s=0,\\frac{1}{2},1,\\frac{3}{2}, 2$) have been constructed. The various spin massless fields can be constructed in terms of the massless conformally coupled scalar field in this formalism. Then the quantum massless minimally coupled scalar field operator, for the first time, is also constructed on Bunch-Davies vacuum state which preserve the analyticity. We show that the massless fields with $s\\leq 2$ can only propagate in de Sitter ambient space formalism. The massless gauge invariant field equations with $s=1, \\frac{3}{2}, 2$ are studied by using the gauge principle. The conformal quantum spin-$2$ field, based on the gauge gravity model, is studied. The gauge spin-$\\frac{3}{2}$ fields satisfy the Grassmannian algebra, and hence, naturally provoke one to couple them with the gauge spin-$2$ field and the super-algebra is automatically appeared. We conclude that the gravitational field may be constructed by three parts, namely, the de Sitter background, the gauge spin-$2$ field and the gauge spin-$\\frac{3}{2}$ field.
Center for Human Reliability Studies
2007-05-01T23:59:59.000Z
The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user
Center for Human Reliability Studies
2007-05-01T23:59:59.000Z
The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.
Rubinfeld, Ronitt
Sublinear time algorithms represent a new paradigm in computing, where an algorithm must give some sort of an answer after inspecting only a very small portion of the input. We discuss the types of answers that one can ...
McInnis, Martha Jane
1982-01-01T23:59:59.000Z
Physical manifestations of time occur in natural forms of all sizes. Architectural form serves as shelter while providing a built envelope of human life, simultaneously influencing and influenced by energetic activities ...
Viscosity, Black Holes, and Quantum Field Theory
D. T. Son; A. O. Starinets
2007-07-11T23:59:59.000Z
We review recent progress in applying the AdS/CFT correspondence to finite-temperature field theory. In particular, we show how the hydrodynamic behavior of field theory is reflected in the low-momentum limit of correlation functions computed through a real-time AdS/CFT prescription, which we formulate. We also show how the hydrodynamic modes in field theory correspond to the low-lying quasinormal modes of the AdS black p-brane metric. We provide a proof of the universality of the viscosity/entropy ratio within a class of theories with gravity duals and formulate a viscosity bound conjecture. Possible implications for real systems are mentioned.
Dark energy as a massive vector field
C. G. Boehmer; T. Harko
2007-01-11T23:59:59.000Z
We propose that the Universe is filled with a massive vector field, non-minimally coupled to gravitation. The field equations of the model are consistently derived and their application to cosmology is considered. The Friedmann equations acquire an extra dark-energy component, which is proportional to the mass of the vector particle. This leads to a late-time accelerated de Sitter type expansion. The free parameters of the model (gravitational coupling constants and initial value of the cosmological vector field) can be estimated by using the PPN solar system constraints. The mass of the cosmological massive vector particle, which may represent the main component of the Universe, is of the order of 10^-63 g.
Electric field induced spin-polarized current
Murakami, Shuichi; Nagaosa, Naoto; Zhang, Shoucheng
2006-05-02T23:59:59.000Z
A device and a method for generating an electric-field-induced spin current are disclosed. A highly spin-polarized electric current is generated using a semiconductor structure and an applied electric field across the semiconductor structure. The semiconductor structure can be a hole-doped semiconductor having finite or zero bandgap or an undoped semiconductor of zero bandgap. In one embodiment, a device for injecting spin-polarized current into a current output terminal includes a semiconductor structure including first and second electrodes, along a first axis, receiving an applied electric field and a third electrode, along a direction perpendicular to the first axis, providing the spin-polarized current. The semiconductor structure includes a semiconductor material whose spin orbit coupling energy is greater than room temperature (300 Kelvin) times the Boltzmann constant. In one embodiment, the semiconductor structure is a hole-doped semiconductor structure, such as a p-type GaAs semiconductor layer.
Massless Dirac Fermions in Electromagnetic Field
Ahmed Jellal; Abderrahim El Mouhafid; Mohammed Daoud
2012-02-12T23:59:59.000Z
We study the relations between massless Dirac fermions in an electromagnetic field and atoms in quantum optics. After getting the solutions of the energy spectrum, we show that it is possible to reproduce the 2D Dirac Hamiltonian, with all its quantum relativistic effects, in a controllable system as a single trapped ion through the Jaynes--Cummings and anti-Jaynes--Cummings models. Also we show that under certain conditions the evolution of the Dirac Hamiltonian provides us with Rashba spin-orbit and linear Dresselhaus couplings. Considering the multimode multiphoton Jaynes-Cummings model interacting with N modes of electromagnetic field prepared in general pure quantum states, we analyze the Rabi oscillation. Evaluating time evolution of the Dirac position operator, we determine the Zitterbewegung frequency and the corresponding oscillating term as function of the electromagnetic field.
Dynamical view of pair creation in uniform electric and magnetic fields
Naoto Tanji
2009-05-12T23:59:59.000Z
Pair creation in a uniform classical electromagnetic field (Schwinger mechanism) is studied focusing on the time evolution of the distribution of created particles. The time evolution of the distribution in time-dependent fields is also presented as well as effects of back reaction. Motivated by the Glasma flux tube, which may be formed at the initial stage of heavy-ion collisions, we investigate effects of a magnetic field parallel to an electric field, and find that the magnetic field makes the evolution of a fermion system faster.
Chapin, Kimberly R.
1997-01-01T23:59:59.000Z
TIME IN QUANTUM MECHANICS A Thesis by KIMBERLY R. CHAPIN Submitted to Texas A8M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved as to style and content by: Marian O. Scully (Chair... of Committee) Edward S. Fry (Member) aan Laane (Member) Thomas W. Adair, III (Head of Department) August 1997 Major Subject: Physics TIME IN QIJANTUM MECHANICS A Thesis by KIMBERLY R. CHAPIN Submitted to the Oflice of Graduate Studies of Texas A...
On the nature of cosmological time
Magain, Pierre
2015-01-01T23:59:59.000Z
Time is a parameter playing a central role in our most fundamental modeling of natural laws. Relativity theory shows that the comparison of times measured by different clocks depends on their relative motions and on the strength of the gravitational field in which they are embedded. In standard cosmology, the time parameter is the one measured by fundamental clocks, i.e. clocks at rest with respect to the expanding space. This proper time is assumed to flow at a constant rate throughout the whole history of the Universe. We make the alternative hypothesis that the rate at which cosmological time flows depends on the dynamical state of the Universe. In thermodynamics, the arrow of time is strongly related to the second law, which states that the entropy of an isolated system will always increase with time or, at best, stay constant. Hence, we assume that time measured by fundamental clocks is proportional to the entropy of the region of the Universe that is causally connected to them. Under that simple assumpt...
None
2013-12-31T23:59:59.000Z
This final report document summarizes the activities undertaken and the output from three primary deliverables generated during this project. This fifteen month effort comprised numerous key steps including the creation of an international methane hydrate science team, determining and reporting the current state of marine methane hydrate research, convening an international workshop to collect the ideas needed to write a comprehensive Marine Methane Hydrate Field Research Plan and the development and publication of that plan. The following documents represent the primary deliverables of this project and are discussed in summary level detail in this final report. • Historical Methane Hydrate Project Review Report • Methane Hydrate Workshop Report • Topical Report: Marine Methane Hydrate Field Research Plan • Final Scientific/Technical Report
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) | SciTechDatastreamsmplDatastreamsxsacrspeccmaskxpol7, 2013 [Facility News, Feature StoriesField Participants Campaign
Noncommutative Dipole Field Theories
K. Dasgupta; M. M. Sheikh-Jabbari
2002-02-05T23:59:59.000Z
Assigning an intrinsic constant dipole moment to any field, we present a new kind of associative star product, the dipole star product, which was first introduced in [hep-th/0008030]. We develop the mathematics necessary to study the corresponding noncommutative dipole field theories. These theories are sensible non-local field theories with no IR/UV mixing. In addition we discuss that the Lorentz symmetry in these theories is ``softly'' broken and in some particular cases the CP (and even CPT) violation in these theories may become observable. We show that a non-trivial dipole extension of N=4, D=4 gauge theories can only be obtained if we break the SU(4) R (and hence super)-symmetry. Such noncommutative dipole extensions, which in the maximal supersymmetric cases are N=2 gauge theories with matter, can be embedded in string theory as the theories on D3-branes probing a smooth Taub-NUT space with three form fluxes turned on or alternatively by probing a space with R-symmetry twists. We show the equivalences between the two approaches and also discuss the M-theory realization.
Polymer Parametrised Field Theory
Alok Laddha; Madhavan Varadarajan
2008-05-02T23:59:59.000Z
Free scalar field theory on 2 dimensional flat spacetime, cast in diffeomorphism invariant guise by treating the inertial coordinates of the spacetime as dynamical variables, is quantized using LQG type `polymer' representations for the matter field and the inertial variables. The quantum constraints are solved via group averaging techniques and, analogous to the case of spatial geometry in LQG, the smooth (flat) spacetime geometry is replaced by a discrete quantum structure. An overcomplete set of Dirac observables, consisting of (a) (exponentials of) the standard free scalar field creation- annihilation modes and (b) canonical transformations corresponding to conformal isometries, are represented as operators on the physical Hilbert space. None of these constructions suffer from any of the `triangulation' dependent choices which arise in treatments of LQG. In contrast to the standard Fock quantization, the non- Fock nature of the representation ensures that the algebra of conformal isometries as well as that of spacetime diffeomorphisms are represented in an anomaly free manner. Semiclassical states can be analysed at the gauge invariant level. It is shown that `physical weaves' necessarily underly such states and that such states display semiclassicality with respect to, at most, a countable subset of the (uncountably large) set of observables of type (a). The model thus offers a fertile testing ground for proposed definitions of quantum dynamics as well as semiclassical states in LQG.
Unbalanced field RF electron gun
Hofler, Alicia
2013-11-12T23:59:59.000Z
A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.
Optical analogs of model atoms in fields
Milonni, P.W.
1991-05-02T23:59:59.000Z
The equivalence of the paraxial wave equation to a time-dependent Schroedinger equation is exploited to construct optical analogs of model atoms in monochromatic fields. The approximation of geometrical optics provides the analog of the corresponding classical mechanics. Optical analogs of Rabi oscillations, photoionization, stabilization, and the Kramers-Henneberger transformation are discussed. One possibility for experimental realization of such optical analogs is proposed. These analogs may be useful for studies of quantum chaos'' when the ray trajectories are chaotic. 9 refs.
Transient magnetic field and temperature modeling in large magnet applications
Gurol, H.; Hardy, G.E.; Peck, S.D.; Leung, E. (General Dynamics Corp., San Diego, CA (USA). Space Systems Div.)
1989-07-01T23:59:59.000Z
This paper discusses a coupled magnetic/thermal model developed to study heat and magnetic field diffusion in conducting materials subject to time-varying external fields. There are numerous applications, both military and commercial. These include: energy storage devices, pulsed power transformers, and electromagnetic launchers. The time scales of interest may range from a magnetic field pulse of a microsecond in an electromagnetic launcher, to hundreds of seconds in an energy storage magnet. The problem can be dominated by either the magnetic field or heat diffusion, depending on the temperature and the material properties of the conductor. In general, heat diffuses much more rapidly in high electrical conductivity materials of cryogenic temperatures. The magnetic field takes longer to diffuse, since screening currents can be rapidly set up which shield the interior of the material from further magnetic field penetration. Conversely, in high resistivity materials, the magnetic field diffuses much more rapidly. A coupled two-dimensional thermal/magnetic model has been developed. The results of this model, showing the time and spatial variation of the magnetic field and temperature, are discussed for the projectile of an electromagnetic launcher.
Electron Dynamics in Nanostructures in Strong Laser Fields
Kling, Matthias
2014-09-11T23:59:59.000Z
The goal of our research was to gain deeper insight into the collective electron dynamics in nanosystems in strong, ultrashort laser fields. The laser field strengths will be strong enough to extract and accelerate electrons from the nanoparticles and to transiently modify the materials electronic properties. We aimed to observe, with sub-cycle resolution reaching the attosecond time domain, how collective electronic excitations in nanoparticles are formed, how the strong field influences the optical and electrical properties of the nanomaterial, and how the excitations in the presence of strong fields decay.
Non-commutative Field Theory with Twistor-like Coordinates
Tomasz R. Taylor
2007-09-16T23:59:59.000Z
We consider quantum field theory in four-dimensional Minkowski spacetime, with the position coordinates represented by twistors instead of the usual world-vectors. Upon imposing canonical commutation relations between twistors and dual twistors, quantum theory of fields described by non-holomorphic functions of twistor variables becomes manifestly non-commutative, with Lorentz symmetry broken by a time-like vector. We discuss the free field propagation and its impact on the short- and long-distance behavior of physical amplitudes in perturbation theory. In the ultraviolet limit, quantum field theories in twistor space are generically less divergent than their commutative counterparts. Furthermore, there is no infrared--ultraviolet mixing problem.
Toward an axiomatic formulation of noncommutative quantum field theory
Chaichian, M.; Tureanu, A. [Department of Physics, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki (Finland); Mnatsakanova, M. N. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, 119992 Vorobyevy Gory, Moscow (Russian Federation); Nishijima, K. [Department of Physics, University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Vernov, Yu. S. [Institute for Nuclear Research, Russian Academy of Sciences, 60th October Anniversary prospect 7a, 117312 Moscow (Russian Federation)
2011-03-15T23:59:59.000Z
We propose new Wightman functions as vacuum expectation values of products of field operators in the noncommutative space-time. These Wightman functions involve the *-product among the fields, compatible with the twisted Poincare symmetry of the noncommutative quantum field theory (NC QFT). In the case of only space-space noncommutativity ({theta}{sub 0i}= 0), we prove the CPT theorem using the noncommutative form of the Wightman functions. We also show that the spin-statistics theorem, demonstrated for the simplest case of a scalar field, holds in NC QFT within this formalism.
The force exerting on cosmic bodies in a quaternionc field
V. Majernik
2003-09-03T23:59:59.000Z
The expression of a time-dependent cosmological constant $\\lambda \\propto 1/t^2$ is interpreted as the energy density of a special type of the quaternionic field. The Lorenz-like force acting on the moving body in the presence of this quaternionic field is determined. The astronomical and terrestrial effects of this field are presented, and the ways how it can be observably detected is discussed. Finally, a new mechanism of the particle creation and an alternative cosmological scenario in the presence of the cosmic quatertionic field is suggested.
Nature of Electric and Magnetic Fields; How the Fields Transform
Tomislav Ivezic
2015-08-10T23:59:59.000Z
In this paper the proofs are given that the electric and magnetic fields are properly defined vectors on the four-dimensional (4D) spacetime (the 4-vectors in the usual notation) and not the usual 3D fields. Furthermore, the proofs are presented that under the mathematically correct Lorentz transformations (LT), e.g., the electric field vector transforms as any other vector transforms, i.e., again to the electric field vector; there is no mixing with the magnetic field vector B, as in the usual transformations (UT) of the 3D fields. The derivations of the UT from some well-known textbooks are discussed and objected.
Generalized Gravitational Entropy of Interacting Scalar Field and Maxwell Field
Wung-Hong Huang
2014-11-11T23:59:59.000Z
The generalized gravitational entropy proposed by Lewkowycz and Maldacena in recent is extended to the interacting real scalar field and Maxwell field system. Using the BTZ geometry we first investigate the case of free real scalar field and then show a possible way to calculate the entropy of the interacting scalar field. Next, we investigate the Maxwell field system. We exactly solve the wave equation and calculate the analytic value of the generalized gravitational entropy. We also use the Einstein equation to find the effect of backreaction of the Maxwell field on the area of horizon. The associated modified area law is consistent with the generalized gravitational entropy.
Nature of Electric and Magnetic Fields; How the Fields Transform
Ivezic, Tomislav
2015-01-01T23:59:59.000Z
In this paper the proofs are given that the electric and magnetic fields are properly defined vectors on the four-dimensional (4D) spacetime (the 4-vectors in the usual notation) and not the usual 3D fields. Furthermore, the proofs are presented that under the mathematically correct Lorentz transformations (LT), e.g., the electric field vector transforms as any other vector transforms, i.e., again to the electric field vector; there is no mixing with the magnetic field vector B, as in the usual transformations (UT) of the 3D fields. The derivations of the UT from some well-known textbooks are discussed and objected.
Cauwenberghs, Gert
similar to those of the Gabor filter simultaneously. Test results indicate that the chips work as expected like to thank K. K. Lau and K. Poon for their help in making measurements of the chip reported here. REFERENCES [1] J. G. Daugman, "Two-dimensional spectral analysis of cortical receptive field profiles
Real-Time Plasma Control Tools for Advanced Tokamak Operation
Varandas, C. A. F.; Sousa, J.; Rodrigues, A. P.; Carvalho, B. B.; Fernandes, H.; Batista, A. J.; Cruz, N.; Combo, A.; Pereira, R. C. [Centro de FuSao Nuclear, Associacao Euratom/IST, Instituto Superior Tecnico, Av. Rovisco Pais, P-1049-001 Lisbon (Portugal)
2006-12-04T23:59:59.000Z
Real-time control will play an important role in the operation and scientific exploitation of the new generation fusion devices. This paper summarizes the real-time systems and diagnostics developed by the Portuguese Fusion Euratom Association based on digital signal processors and field programmable gate arrays.
Visualization of Very Large Oceanography Time-Varying Volume Datasets
Laidlaw, David
Visualization of Very Large Oceanography Time-Varying Volume Datasets Sanghun Park1 , Chandrajit://grmanet.sogang.ac.kr/~ihm Abstract. This paper presents two visualization techniques suitable for huge oceanography time generated in the field of oceanography. The model has a resolution of 1/6 degree (2160 by 960 points
WIDE-FIELD ASTRONOMICAL MULTISCALE CAMERAS
Marks, Daniel L.; Brady, David J., E-mail: dbrady@ee.duke.edu [Department of Electrical and Computer Engineering and Fitzpatrick Institute for Photonics, Box 90291, Duke University, Durham, NC 27708 (United States)
2013-05-15T23:59:59.000Z
In order to produce sufficiently low aberrations with a large aperture, telescopes have a limited field of view. Because of this narrow field, large areas of the sky at a given time are unobserved. We propose several telescopes based on monocentric reflective, catadioptric, and refractive objectives that may be scaled to wide fields of view and achieve 1.''1 resolution, which in most locations is the practical seeing limit of the atmosphere. The reflective and Schmidt catadioptric objectives have relatively simple configurations and enable large fields to be captured at the expense of the obscuration of the mirror by secondary optics, a defect that may be managed by image plane design. The refractive telescope design does not have an obscuration but the objective has substantial bulk. The refractive design is a 38 gigapixel camera which consists of a single monocentric objective and 4272 microcameras. Monocentric multiscale telescopes, with their wide fields of view, may observe phenomena that might otherwise be unnoticed, such as supernovae, glint from orbital space debris, and near-earth objects.
Timed Alternating-Time Temporal Logic Thomas A. Henzinger1
Henzinger, Thomas A.
equally powerful options for updating the state of the game, advancing time, or blocking time. Second, we in order to specify real-time objectives for games played on timed structures. We define the semantics Timed games are a formal model for the synthesis of real-time systems [22, 20]. While much research