james clerk maxwell: Topics by WorldWideScience.org

On duality of the noncommutative supersymmetric Maxwell-Chern-Simons theory

NASA Nebula in Action: Cloud Computing Case Examples. James Williams, NASA Ames Research Center, james.f.williams@nasa.gov. Abstract In 2009 ...

Recursive AR Spectral Estimation.

No abstract prepared.

2008-07-01

T - Stardust | JPL | NASA

... ENGINEERING. Personal Author(s) : Ogino,Koji ; Cadzow,James A. Report Date : 1980. Pagination or Media Count : 18. ...

NASA - IT Summit 2011 Speaker Bios

Jul 16, 2001... HAROLD DAVID TASKIS KIRIL TASKOV STEVEN P. TASLER F. .... SHEILA THACKERAY JAMES S. THACKRAY KEITH THACKREY JUDE ...

Inverse Scattering and Applications. Proceedings of ...

Aug 1, 2011 ... James holds a Bachelor of Science degree in Computer Science and certifications as CISSP, CCNA, and CCDA. show hide. Phillip A. Newman ...

Influence of JA-Me in biosynthesis of phospholipids in germinating yellow lupin (Lupinus luteus) seeds

... Richrd Bals andLina PrissJames Lepowsky and Mirko Primc Richard Beaals, and Linda Preiss Rothschild, Editors 47 Linear algebra and its role in ...

2011-05-14

An ecological analysis of knowing by wielding.

English 2008 p. 216 Poland Zalewski, K. Nitkiewicz, B. Department of

2008-09-07

UK PubMed Central (United Kingdom)

The ecological approach to perception, as developed by James Gibson, is described and applied to how one knows, by means of the haptic perceptual system, various properties of hand-held objects. Four...Full Text Available

1989-11-01

Adaptive ARMA Spectral Estimation,

APOD: 2005 November 25 - Moon Over Antarctica

... ENGINEERING. Personal Author(s) : Cadzow,James A. ; Ogino,Koji. Report Date : 1981. Pagination or Media Count : 7. Abstract ...

A Call for an Official Naval Doctrine

on the picture will download the highest resolution version available. Moon Over Antarctica Credit & Copyright: James Behrens (IGPP, Scripps Institution of Oceanography)...

2011-10-14

Maxwell-Podolsky theory with higher order Chern-Simons term: a model without tachyons?; Teoria de Maxwell-Podolsky com termo de Chern-Simons de ordem superior: um modelo sem taquions?

... 1. Major Grover E. Myers, Aerospace Power: The Case for Indivisible ... 19. Admiral James D. Watkins, The Maritime Strategy (Annapolis: US Naval ...

1992-02-13

Use of Microelectrode Arrays to Directly Measure Diffusion of ...

Short communication.

1994-12-31

Seal is successful at Italys largest pumped storage plant

... F.; Murray, R. W. J. Am. Chem. ... 14. Thackeray, J. W.; White, H. S.; Wrighton, M. SJ Phys. ... Dr. James S. Murday (1) Dr. Harold H. Singerman (i) ...

1990-05-16

British Library Electronic Table of Contents (United Kingdom)

A HydroSele S seal from James Walker has provided more than two years maintenance-free service at the large Entracque pumped-storage hydroelectric scheme in Italy.

2008-01-01

IDEAS: Agricultural Systems, Elsevier

Wastenet

... (restricted)] 256-264 Influence of likelihood function choice for estimating crop model parameters using the generalized likelihood uncertainty estimation method by He, Jianqiang & Jones, James W. & Graham, Wendy D. & Dukes, Michael D. [Downloadable! (restricted)]...

1 Transcript of Presidential Meeting in the ... - NASA History Office

Global existence for the Euler-Maxwell system

increased knowledge as result of about a year's work, has led us first to ...... James Webb: And the advanced technology on which military power is going to be ..... on the road and I've been with the real big dogs and I know the deal ...

Computer Algebra meets Finite Elements: an Efficient Implementation for Maxwell's Equations

The Euler-Maxwell system describes the evolution of a plasma when the collisions are important enough that each species is in a hydrodynamic equilibrium. In this paper we prove global existence of small solutions to this system set in the whole three-dimensional space, by combining the space-time resonance method, dispersive estimates, localization estimates and energy estimates. An important novelty is that we can prove a very slow growth of high derivatives even with a nonintegrable decay by reiterating the energy estimate.

2011-01-01

Implications of the Electrostatic Approximation in the Beam Frame on the Nonlinear Vlasov-Maxwell Equations for Intense Beam Propagation

We consider the numerical discretization of the time-domain Maxwell's equations with an energy-conserving discontinuous Galerkin finite element formulation. This particular formulation allows for higher order approximations of the electric and magnetic field. Special emphasis is placed on an efficient implementation which is achieved by taking advantage of recurrence properties and the tensor-product structure of the chosen shape functions. These recurrences have been derived symbolically with computer algebra methods reminiscent of the holonomic systems approach.

2011-01-01

On the Approach to Spherical Harmonics by Maxwell, Thomson and Tait

This paper develops a clear procedure for solving the nonlinear Vlasov-Maxwell equations for a one-component intense charged particle beam or finite-length charge bunch propagating through a cylindrical conducting pipe (radius r = r(subscript)w = const.), and confined by an applied focusing force. In particular, the nonlinear Vlasov-Maxwell equations are Lorentz-transformed to the beam frame ('primed' variables) moving with axial velocity relative to the laboratory. In the beam frame, the particle motions are nonrelativistic for the applications of practical interest, already a major simplification. Then, in the beam frame, we make the electrostatic approximation which fully incorporates beam space-charge effects, but neglects any fast electromagnetic processes with transverse polarization (e.g., light waves). The resulting Vlasov-Maxwell equations are then Lorentz-transformed back to the laboratory frame, ...

2001-11-08

1 2 3 4

Second primary cancers of the breast: incidence and risk factors.

We present a unified self-consistent review of the approach to spherical harmonics developed in the second half of the 19th century by Maxwell and by Thomson and Tait. We remark how this spherical coordinate-free approach straightforwardly leads to physically very important results of the theory of solid and surface harmonics which become rather tedious to work out when using spherical coordinates and associated Legendre functions. These results include, among others, the addition theorem, spherical wave expansions, the construction of the standard set of normalized spherical harmonics, Y_lm - together with their rotational properties-, and recursion relations. We provide new proofs for Maxwell's theorem, the addition theorem and Hobson's theorem, respectively, using in the latter some elementary notions of the symbolic techniques proper of the theory of invariants. Also, we give an approach based on compact vector methods to express the ...

2008-01-01

UK PubMed Central (United Kingdom)

Between 1946 and 1976 over 9,000 women with breast cancer were seen within one year of diagnosis at the A. Maxwell Evans Clinic (AMEC) in Vancouver, British Columbia. By 1978, 275 had a subsequent diagnosis...Full Text Available

1984-01-01

Quaternionic formulation for electromagnetic-field equations

Deforming the Maxwell-Sim algebra

The quaternionic formalism for subluminal field equations (Maxwell's equations) and its interrelationship with complex superluminal Lorentz transformations have been given and it has been shown that the quaternionic forms of relativistic equations describe tachyons.

1983-07-02

Strong Convergence towards homogeneous cooling states for dissipative Maxwell models

The Maxwell algebra is a noncentral extension of the Poincare algebra, in which the momentum generators no longer commute, but satisfy [P?,P?]=Z??. The charges Z?? commute with the momenta, and transform tensorially under the action of the angular momentum generators. If one constructs an action for a massive particle, invariant under these symmetries, one finds that it satisfies the equations of motion of a charged particle interacting with a constant electromagnetic field via the Lorentz force. In this paper, we explore the analogous constructions where one starts instead with the ISim subalgebra of Poincare, this being the symmetry algebra of very special relativity. It admits an analogous noncentral extension, and we find that a particle action invariant under this Maxwell-Sim algebra again describes a particle subject to the ordinary Lorentz force. One can also deform the ISim algebra to DISimb, where b is a nontrivial dimensionless ...

2010-09-15

A nonmolecular derivation of Maxwell's thermal-creep boundary condition in gases and liquids via application of the LeChatelier-Braun principle to Maxwell's thermal stress

We show the propagation of regularity, uniformly in time, for the scaled solutions of the inelastic Maxwell model for small inelasticity. This result together with the weak convergence towards the homogenous cooling state present in the literature implies the strong convergence in Sobolev norms and in the $L^1$ norm towards it depending on the regularity of the initial data. The strategy of the proof is based on a precise control of the growth of the Fisher information for the inelastic Boltzmann equation. Moreover, as an application we obtain a bound in the $L^1$ distance between the homogeneous cooling state and the corresponding Maxwellian distribution vanishing as the inelasticity goes to zero.

2008-01-01

Large cardinals with few measures

According to the LeChatelier-Braun principle, when a closed quiescent system initially in an equilibrium or unstressed steady state is subjected to an externally imposed ``stress'' it responds in a manner tending to alleviate that stress. Use of this entropically based qualitative rule, in combination with the notion of Maxwell thermal stresses existing in nonisothermal gases and liquids, enables one to (i) derive Maxwell's thermal-creep boundary condition prevailing at the boundary between a solid and a fluid (either gas or liquid) and (ii) rationalize the phenomenon of thermophoresis in liquids, for which, in contrast with the case of gases, an elementary explanation is currently lacking. These two objectives are achieved by quantitatively interpreting the heretofore qualitative LeChatelier-Braun notion of stress in the present context as being the fluid's stress tensor, the latter including Maxwell's thermal stress. In ...

2009-05-01

Characterization of carbon-based electrochemical capacitor technology from Maxwell Energy Products, Inc.

We show, assuming the consistency of one measurable cardinal, that it is consistent for there to be exactly kappa+ many normal measures on the least measurable cardinal kappa. This answers a question of Stewart Baldwin. The methods generalize to higher cardinals, showing that the number of lambda strong compactness or lambda supercompactness measures on P_kappa(lambda) can be exactly lambda+, if lambda>kappa is a regular cardinal. We conclude with a list of open questions. Our proofs use a critical observation due to James Cummings.

2006-01-01

From Whitney Forms to Metamaterials: a Rigorous Homogenization Theory

The electrochemical capacitor devices described in this report were deliverables from the US Department of Energy--Idaho Operations Office (DOE-ID) Contract No. DE-AC07-92ID13404 as part of the US Department of Energy`s (DOE) High Power Energy Storage Program. The Idaho national Engineering and Environmental Laboratory (INEEL) has responsibility for technical management, testing, and evaluation of high-power batteries and electrochemical capacitors under this Program. The DOE has developed various electrochemical capacitors as candidate power assist devices for the Partnership for a New Generation of Vehicles (PNGV) fast response engine requirement. This contract with Maxwell Energy Products, Inc. (Maxwell) was intended to develop a high-energy-density, high-power-density ultracapacitor that is capable of load leveling batteries in electric vehicles. The performance criteria for this device are delivery of 5 W {center_dot} h/kg of useful energy ...

1998-04-01

Analysis of microwave induced natural convection in a single mode cavity (Influence of sample volume, placement, and microwave power level)

A rigorous homogenization theory of metamaterials -- artificial periodic structures judiciously designed to control the propagation of electromagnetic waves -- is developed. All coarse-grained fields are unambiguously defined and effective parameters are then derived without any heuristic assumptions. The theory is an amalgamation of two concepts: Smith & Pendry's physical insight into field averaging and the mathematical framework of Whitney-Nedelec-Bossavit-Kotiuga interpolation. All coarse-grained fields are defined via Whitney forms and satisfy Maxwell's equations exactly. The new approach is illustrated with several analytical and numerical examples and agrees well with the established results (e.g. the Maxwell-Garnett formula and the zero cell-size limit) within the range of applicability of the latter. The sources of approximation error and the respective suitable error indicators are clearly identified, along with systematic routes ...

2010-01-01

British Library Electronic Table of Contents (United Kingdom)

The heating of water layer using microwave oven with a rectangular waveguide has been studied both numerically and experimentally. The mathematical model is validated with the experimental data. The transient Maxwell's equations are solved by using the Finite Difference Time Domain (FDTD) method to describe the electromagnetic field inside the waveguide and sample. The temperature profile and velocity field within sample are determined by the solutions of the momentum, energy and Maxwell's equations. In this study, the effects of physical parameters, e.g. microwave power level, placement of sample inside the waveguide, volume of sample, are studied. The distribution of electric field, temperature profile and velocity field are presented in details. The results show good agreement between s...

2012-01-01

The arts of indigenous online dissent: Negotiating technology, indigeneity, and activism in the Cordillera

British Library Electronic Table of Contents (United Kingdom)

The online communicative environment is expected to revolutionize political discourse as it expands to cover underrepresented groups and ideas. In this platform, marginalized groups such as indigenous communities from the developing world can articulate claims, strategically mobilize and participate in the forms of meaning-making that constitute them. However, there is skepticism on the actual value of online spaces in effecting agency in an internet-mediated environment. Using James Scott's notion of 'hidden transcripts' and Andrew Feenberg's 'democratic rationalization of technology', the paper explores strategic approaches and historical, social, and political conditions embedded in the construction, negotiation, and transformation of indigenous online activist media. In-depth interview...

2012-01-01

IDEAS: Networks and Spatial Economics, Springer

Wastenet

... (restricted)] 255-269 Inefficiency of Logit-Based Stochastic User Equilibrium in a Traffic Network Under ATIS by Hai-Jun Huang & Tian-Liang Liu & Xiaolei ...Hub-catchment Areas, Existing Hubs, and Simulation: A Case Study of Serbian Intermodal Terminals by Milorad Vidovic & Slobodan Zecevic & Milorad Kilibarda ... (restricted)] 389-410 Stochastic Location-assignment on an Interval with Sequential Arrivals by Kannan Viswanath & James Ward [Downloadable! (restricted)] ... (restricted)] 193-208 Solving Stochastic Transportation Network Protection Problems Using the Progressive Hedging-based Method by Yueyue Fan & Changzheng Liu [Downloadable! (...

Tachyons and magnetic monopoles in the De Sitter universe

Statistical mechanics and thermodynamics for tachyons

The author examines the place of tachyons and magnetic monopoles in the 'projective relativity' theory, which is based on the De Sitter universe and which has special relativity as a limiting case. A link with a generalized form of Maxwell's equations is examined in detail, the connection being through the rotation group R_5. (W.D.L.).

Reduction of four-vector field in terms of standard helicity representation of inhomogeneous Lorentz group for imaginary mass system

Momentum- and speed-dependent Maxwell-Boltzmann equilibrium distributions have been derived for tachyons and compared with the corresponding relativistic distributions. This is followed by a calculation of the mean, most probable and r.m.s. speeds for both the relativistic and tachyonic distributions. The ideal gas of tachyons is discussed, including calculations of the internal energy and entropy. In each case a comparison is made with the corresponding bradyonic results. It is found that tachyons behave just like bradyons in the high-temperature limit, but have markedly different behaviour at low temperatures.

Numerical Modeling of the RF Plasma Production in URAGAN-2M Stellarator with Crankshaft Antenna

The reduction of four-vector and electromagnetic fields produced by spin-1 tachyons has been derived in terms of standard helicity representations of inhomogeneous Lorentz group, and the conditions for these superluminal electromagnetic fields to satisfy the Maxwell's field equations have been derived. 16 refs.

1981-11-01

British Library Electronic Table of Contents (United Kingdom)

The qualitative technique of the analysis of the efficiency of the RF plasma production is presented in which the solution of boundary problem for Maxwell's equations is only necessary. The analysis of the character of the plasma production process with the crankshaft antenna in Uragan-2M stellarator is carried out. The discussion of the calculations results is presented.

2006-01-01

W.E.B. Du Bois

Abstract This article introduces some of the key philosophical contributions of W. E. B. Du Bois. Du Bois studied with Santayana and William James (among others), but chose social science, social theory, journalism, and activism over academic philosophy. Despite this detour, the philosophic depth of his work has won the attention of scholars in fields such as history, English, post colonial theory, African American Studies, American philosophy, and Africana philosophy, and it has belatedly begun to attract the interest of philosophers more generally. This brief overview will explore the philosophical dimensions of some of Du Bois s best known positions his claims about the color line and the Talented Tenth, his argument with Booker T. Washington, and his account of double consciousness. Th...

2010-01-01

Nuclear War. The moral dimension

Meeting report: A celebration of the work of Professor Tony Hart, Liverpool, United Kingdom, 7 March 2009

U.S. nuclear policy has become the target of increasing criticism during the past decade. Critics often argue that the use of nuclear weapons would be irrational, would destroy humankind, and thus could not serve any rational policy goal. Other critics point to the immortality of the use of nuclear weapons. Both groups condemn U.S. military policy. In Nuclear War, James Child considers and rejects both these lines of criticism. He argues that a policy of deterrence can be both rational and moral; that U.S. nuclear policy is, on balance, based on rational and moral foundations. Child examines near-term consequences of a nuclear war and finds them ghastly but not unthinkable or incomparable to the havoc produced by previous wars. He also analyzes long-term consequences, such as those proposed by the ''nuclear winter'' theory, and finds the fear of total annihilation of humankind to be unfounded.

1985-01-01

British Library Electronic Table of Contents (United Kingdom)

Over 300 delegates participated in this scientific meeting to celebrate the career of the late Professor Tony Hart, who was Head of Department of Medical Microbiology, University of Liverpool, from 1986 until his death in September 2007. The meeting, which was opened by Professor James Stewart (Head, School of Infection and Host Defence, University of Liverpool) and closed by Professor Bernard Brabin (Head of the Child Health Group, Liverpool School of Tropical Medicine), captured some of the major elements that distinguished Tony Harts remarkable career. These included: broad research interests spanning both human and veterinary medicine; the ability to conduct both clinical and basic science research with equal skill and vigour; and his phenomenal mentorship of postgraduate students. Eac...

2010-01-01

Striped instability of a holographic Fermi-like liquid

Impact of an initial energy chirp and an initial energy curvature on a seeded free electron laser: free electron laser properties

We consider a holographic description of a system of strongly-coupled fermions in 2+1 dimensions based on a D7-brane probe in the background of D3-branes. The black hole embedding represents a Fermi-like liquid. We study the excitations of the Fermi liquid system. Above a critical density which depends on the temperature, the system becomes unstable towards an inhomogeneous modulated phase which is similar to a charge density and spin wave state. The essence of this instability can be effectively described by a Maxwell-axion theory with a background electric field. We also consider the fate of zero sound at non-zero temperature.

2011-01-01

1 2 3 4

Dirac Fields in Loop Quantum Gravity and Big Bang Nucleosynthesis

In a free electron laser (FEL), the electron bunch energy profile at the undulator entrance can have temporal structures. In this paper, we derive analytical expressions for the FEL in the undulator, in the case of the electron bunch having both energy chirp and energy curvature. The FEL properties are studied analytically by convoluting a Gaussian seed laser with the FEL Green's function obtained by solving the coupled Vlasov-Maxwell equations. In particular, for different ratios of the temporal duration of the seed laser and that of the Green's function, interesting behavior is revealed.

2009-02-27

Big Bang nucleosynthesis requires a fine balance between equations of state for photons and relativistic fermions. Several corrections to equation of state parameters arise from classical and quantum physics, which are derived here from a canonical perspective. In particular, loop quantum gravity allows one to compute quantum gravity corrections for Maxwell and Dirac fields. Although the classical actions are very different, quantum corrections to the equation of state are remarkably similar. To lowest order, these corrections take the form of an overall expansion-dependent multiplicative factor in the total density. We use these results, along with the predictions of Big Bang nucleosynthesis, to place bounds on these corrections.

2007-01-01

Quantum Thermodynamic Cycles and quantum heat engines

In this paper, we discuss the large--time behavior of solution of a simple kinetic model of Boltzmann--Maxwell type, such that the temperature is time decreasing and/or time increasing. We show that, under the combined effects of the nonlinearity and of the time--monotonicity of the temperature, the kinetic model has non trivial quasi-stationary states with power law tails. In order to do this we consider a suitable asymptotic limit of the model yielding a Fokker-Planck equation for the distribution. The same idea is applied to investigate the large-time behavior of an elementary kinetic model of economy involving both exchanges between agents and increasing and/or decreasing of the mean wealth. In this last case, the large-time behavior of the solution shows a Pareto power law tail. Numerical results confirm the previous analysis.

2010-01-01

Post-lens tear-film depletion due to evaporative dehydration of a soft contact lens

In order to describe quantum heat engines, here we systematically study isothermal and isochoric processes for quantum thermodynamic cycles. Based on these results the quantum versions of both the Carnot heat engine and the Otto heat engine are defined without ambiguities. We also study the properties of quantum Carnot and Otto heat engines in comparison with their classical counterparts. Relations and mappings between these two quantum heat engines are also investigated by considering their respective quantum thermodynamic processes. In addition, we discuss the role of Maxwell's demon in quantum thermodynamic cycles. We find that there is no violation of the second law, even in the existence of such a demon, when the demon is included correctly as part of the working substance of the heat engine.

2006-01-01

British Library Electronic Table of Contents (United Kingdom)

For a soft-contact-lens (SCL) wearer, corneal health and comfort are strongly influenced by water transport through the polymeric materials used in lens fabrication. In particular, evaporative water loss at the anterior lens surface is a potential cause of contact-lens dehydration and of post-lens tear-film depletion, which in turn, may lead to discomfort, dryness syndrome, and/or lens adhesion.We present a solution-diffusion model for transport of water through soft-contact-lens materials to mimic evaporative dehydration from a contact lens during blinking and to access possible SCL adhesion to the corneal surface under a variety of environmental conditions (e.g., wind speed and relative humidity). To describe the water-transport process, we use an extended version of the Maxwell-Stefan m...

2006-01-01

On the electrodynamics of tachyons

On Essential Incompleteness of Hertz's Experiments on Propagation of Electromagnetic Interactions

Electrodynamic properties of processes involving charged tachyons are considered in connection with the real superluminal Lorentz transformations. These transformations are interpreted without making use of a tachon corridor and so that the interaction of tachyons from subluminal sources with ordinary matter is Lorentz invariant. Transformations of the electromagnetic fields are deduced from the extended principle of relativity. They are necessary in order to obtain the field equations that are satisfied by fields obeying Maxwell equations relative to superluminal inertial frames with respect to subluminal inertial frames. The field equations allow one to get the dependence of the field energy density and its current on the field strengths. The resulting equations are applied in a discussion of plane electromegnetic waves, sent out by a superluminal source. The obtained electrodynamics allows the existence of charged tatric charges do not behave as magnetic ...

Numerical modeling of a MEMS actuator considering several magnetic force calculation methods

The historical background of the 19th century electromagnetic theory is revisited from the standpoint of the opposition between alternative approaches in respect to the problem of interactions. The 19th century electrodynamics became the battle-field of a paramount importance to test existing conceptions of interactions. Hertz's experiments were designed to bring a solid experimental evidence in favor of one of them. The modern scientific method applied to analyze Hertz's experimental approach as well as the analysis of his laboratory notes, dairy and private letters show that Hertz's "\\textit{crucial}" experiments cannot be considered as conclusive at many points as it is generally implied. We found that alternative Helmholtz's electrodynamics did not contradict any of Hertz's experimental observations of transverse components as Maxwell's theory predicted. Moreover, as we now know from recently published Hertz's dairy and private notes, his first experimental ...

2005-01-01

British Library Electronic Table of Contents (United Kingdom)

Purpose - The purpose of this paper is to investigate the accuracy of different force calculation methods and their impact on mechanical deformations. For this purpose, a micrometer scaled actuator is considered, which consists of a micro-coil and of a permanent magnet (PM) embedded in a deformable elastomeric layer. Design/methodology/approach - For the magnetic field evaluation a hybrid numerical approach (finite element method/boundary element method (FEM/BEM) coupling and a FEM/BEM/Biot-Savart approach) is used, whereas FEM is implemented for the mechanical deformation analysis. Furthermore, for the magneto-mechanical coupling several force calculation methods, namely the Maxwell stress tensor, the virtual work approach and the equivalent magnetic sources methods, are considered and co...

2011-01-01

Magnetotelluric inversion via reverse time migration algorithm of seismic data

Generation of synthetic seasonal hydrographs for a large river basin

We propose a new algorithm for two-dimensional magnetotelluric (MT) inversion. Our algorithm is an MT inversion based on the steepest descent method, borrowed from the backpropagation technique of seismic inversion or reverse time migration, introduced in the middle 1980s by Lailly and Tarantola. The steepest descent direction can be calculated efficiently by using the symmetry of numerical Green's function derived from a mixed finite element method proposed by Nedelec for Maxwell's equation, without calculating the Jacobian matrix explicitly. We construct three different objective functions by taking the logarithm of the complex apparent resistivity as introduced in the recent waveform inversion algorithm by Shin and Min. These objective functions can be naturally separated into amplitude inversion, phase inversion and simultaneous inversion. We demonstrate our algorithm by showing three inversion results for synthetic data.

2007-07-01

British Library Electronic Table of Contents (United Kingdom)

Summary This paper describes a methodology for the generation of synthetic seasonal stage hydrographs with a number of flood waves for a large braided river basin based on statistical analysis of the historical stage records. The synthetic seasonal hydrographs in a river is required for different purposes such as assessing the hydraulic performances of various river training structures, morphological predictions, environmental impact analysis. The typical stage hydrograph of such a river has two components: flood waves and seasonal (monsoonal) response. Using historical stage records, flood waves in a seasonal stage record were identified and their characteristics were approximated using Maxwell distribution. The extracted characteristics of flood waves such as time of occurrence and succe...

2010-01-01

External quality control for immunocytochemistry on cytology samples: a review of UK NEQAS ICC (cytology module) results

British Library Electronic Table of Contents (United Kingdom)

I. S. Kirbis, P. Maxwell, M. S. Flear, K. Miller and M. Ibrahim External quality control for immunocytochemistry on cytology samples: a review of UK NEQAS ICC (cytology module) results Objective:- To date, external quality control for immunocytochemistry on cytology samples is provided only by the United Kingdom national external quality assessment service for immunocytochemistry and in situ hybridisation (UK NEQAS ICC & ISH). For the purpose of this study a retrospective analysis of a comprehensive collection of quality-related data regarding immunocytochemistry on cytology samples collected through this service was analysed. Methods:- The quality of immunocytochemical reactions, using on-line collected data, was analysed for the last 23 UK NEQAS ICC cytology module external quality asses...

2011-01-01

Design and development of an innovative hybrid powder based on a computer simulation and its application to foundation makeup products

British Library Electronic Table of Contents (United Kingdom)

An innovative hybrid powder prepared using computer simulation allowed development of a new foundation having a fine, smooth texture that has never been achieved before. The optical structure/design of the powder was based on the results of measurements and analyses conducted on the optical characteristics of a baby's delicate skin, which is the envy of many women. To obtain the optimal optical characteristics, the finite differential time domain (FDTD) method for solving Maxwell's differential equation by difference and time domain was applied to the computer simulation method. For synthesis of the hybrid powder based on the optical model, a proprietary shape regulation coating technology was used in which flaky substrates were coated with microspherical forms of barium sulfate crystals. ...

2008-01-01

Body-and-cad Geometric Constraint Systems

A one-dimensional, two-phase model for direct methanol fuel cells - Part I: Model development and parametric study

Motivated by constraint-based CAD software, we develop the foundation for the rigidity theory of a very general model: the body-and-cad structure, composed of rigid bodies in 3D constrained by pairwise coincidence, angular and distance constraints. We identify 21 relevant geometric constraints and develop the corresponding infinitesimal rigidity theory for these structures. The classical body-and-bar rigidity model can be viewed as a body-and-cad structure that uses only one constraint from this new class. As a consequence, we identify a new, necessary, but not sufficient, counting condition for minimal rigidity of body-and-cad structures: nested sparsity. This is a slight generalization of the well-known sparsity condition of Maxwell.

2010-01-01

British Library Electronic Table of Contents (United Kingdom)

A one-dimensional, steady-state, two-phase direct methanol fuel cell (DMFC) model is developed to precisely investigate complex physiochemical phenomena inside DMFCs. In this model, two-phase species transport through the porous components of a DMFC is formulated based on Maxwell-Stefan multi-component diffusion equations, while capillary-induced liquid flow in the porous media is described by Darcy's equation. In addition, the model fully accounts for water and methanol crossover through the membrane, which is driven by the effects of electro-osmotic drag, diffusion, and the hydraulic pressure gradient. The developed model is validated against readily available experimental data in the literature. Then, a parametric study is carried out to investigate the effects of the operating temperat...

2010-01-01

Theoretical nuclear physics. Final report

Alternative methods to determine headwater benefits

As the three-year period FY93-FY96 ended, there were six senior investigators on the grant full-time: Bulgac, Henley, Miller, Savage, van Kolck and Wilets. This represents an increase of two members from the previous three-year period, achieved with only a two percent increase over the budget for FY90-FY93. In addition, the permanent staff of the Institute for Nuclear Theory (George Bertsch, Wick Haxton, and David Kaplan) continued to be intimately associated with our physics research efforts. Aurel Bulgac joined the Group in September, 1993 as an assistant professor, with promotion requested by the Department and College of Arts and Sciences by September, 1997. Martin Savage, who was at Carnegie-Mellon University, jointed the Physics Department in September, 1996. U. van Kolck continued as research assistant professor, and we were supporting one postdoctoral research associate, Vesteinn Thorssen, who joined us in September, 1995. Seven graduate students were being supported by the ...

1997-05-01

Field simulation of axisymmetric plasma screw pinches by alternating-direction-implicit methods

In 1992, the Federal Energy Regulatory Commission (FERC) began using a Flow Duration Analysis (FDA) methodology to assess headwater benefits in river basins where use of the Headwater Benefits Energy Gains (HWBEG) model may not result in significant improvements in modeling accuracy. The purpose of this study is to validate the accuracy and appropriateness of the FDA method for determining energy gains in less complex basins. This report presents the results of Oak Ridge National Laboratory`s (ORNL`s) validation of the FDA method. The validation is based on a comparison of energy gains using the FDA method with energy gains calculated using the MWBEG model. Comparisons of energy gains are made on a daily and monthly basis for a complex river basin (the Alabama River Basin) and a basin that is considered relatively simple hydrologically (the Stanislaus River Basin). In addition to validating the FDA method, ORNL was asked to suggest refinements and improvements to the FDA method. ...

1997-11-10

Electron density and collision frequency of microwave resonant cavity produced discharges. [Progress report

An axisymmetric plasma screw pinch is an axisymmetric column of ionized gaseous plasma radially confined by forces from axial and azimuthal currents driven in the plasma and its surroundings. This dissertation is a contribution to detailed, high resolution computer simulation of dynamic plasma screw pinches in 2-d {ital rz}-coordinates. The simulation algorithm combines electron fluid and particle-in-cell (PIC) ion models to represent the plasma in a hybrid fashion. The plasma is assumed to be quasineutral; along with the Darwin approximation to the Maxwell equations, this implies application of Ampere`s law without displacement current. Electron inertia is assumed negligible so that advective terms in the electron momentum equation are ignored. Electrons and ions have separate scalar temperatures, and a scalar plasma electrical resistivity is assumed. Altemating-direction-implicit (ADI) methods are used to advance the electron fluid drift velocity and the magnetic ...

1996-06-01

Reverse time migration for ground penetrating radar using finite difference time domain method; Jikan ryoiki yugenn sabunho ni yoru chichu reda no ribasu taimu maigureshon

This progress report consists of an article, the abstract of which follows, and apparently the references and vita from a proposal. A review of perturbation diagnostics applied to microwave resonant cavity discharges is presented. The classical microwave perturbation technique examines the shift in the resonant frequency and cavity quality factor of the resonant cavity caused by low electron density discharges. However, modifications presented here allow the analysis to be applied to discharges with electron densities beyond the limit predicted by perturbation theory. An {open_quote}exact{close_quote} perturbation analysis is presented which models the discharge as a separate dielectric, thereby removing the restrictions on electron density imposed by the classical technique. The {open_quote}exact{close_quote} method also uses measurements of the shifts in the resonant conditions of the cavity. Thirdly, an electromagnetic analysis is presented which uses a characteristic equation, ...

1992-12-31

Observation of high permittivity in Ho substituted BaZr_0_._1Ti_0_._9O_3 ceramics

The reversion time migration, as one of reflection seismic prospecting migration, reverse propagates a wave equation by reverse promoting the differential time, and conducts the migration. The method has such merits as no limit to the inclined angle of a reflection, correspondence to a complex topography etc. And, there is a finite difference time domain (FDTD) that uses the Maxwell equation as it is and makes a difference approximation in the methods differentiating and resolving electro-magnetic fields. It is also possible to apply the reverse time migration onto it. In this speech, using an explosive reflection face, a slope 2 layer structure and models of its reflection points are synthesized by a ground penetrating radar using the FDTD, and reverse time migration is conducted. As a result, it is clarified that the reverse time migration is valid for the ground penetrating radar recording. And, the cases including a diffusion item in the equation are also ...

1999-02-01

Neutron and gamma transport in air by TRIPOLI-2 time dependent energy deposition and electron current calculation

The authors observed an extremely high permittivity (#approx#35 000 at T_C) in barium zirconate titanate (BaZr_0_._1Ti_0_._9O_3) ceramics with holmium substitution (1-5 mol %) in Ba site. Careful microstructural investigation and energy dispersive spectroscopy analysis of the 1-2 mol % of Ho substituted ceramics showed the enrichment of a Ho-phase along the grain boundaries with a composition close to the Ho_2Ti_2O_7 pyrochlore. The formation of Ho rich phase resulted in the Maxwell-Wagner polarization mechanism, which leads to this unusually high permittivity. Ceramics with 3 mol % or higher Ho content showed lesser permittivity values compared to 1-2 mol %, probably due to the increase in pyrochlore phase. These high dielectric constant ceramics are useful in nanoscale devices.

2007-07-09

1 2 3 4

Morphology of wood species affecting wood-thermoplastic interaction: microstructure and mechanical adhesion

The electromagnetic field due to an air explosion is here studied: neutron and the gamma-rays, generated by neutronic reactions, deposit energy which ionizes atmosphere; recoil electrons are also created by gamma collisions. This data set allows to solve the Maxwell equations which manage the electromagnetic field. The TRIPOLI-2 code studies the coupled neutron-gamma transport in 3D- geometries by the Monte Carlo method. The code has been modified to calculate the photon energy deposited in matter and the recoil electron current created by Compton effect. The method is tested wiht a simple case; then neutron and gamma transport is studied in air kerma, deposited photon energy, electron current are calculated as functions of space and time and the contributions of the different neutronic reactions are separately evaluated. The calculations presented here are only part of studies about this subject. Developments will relate three dimensional calculations and the ...

1988-09-12

Scientific Electronic Library Online (English)

Abstract in english The main objective of the research presented here is to relate anatomical features of wood species that affect the interactions between polymeric phases and performance of wood plastic composites (WPC). These interactions are related to the probable interlocking volume and surface area for stress transfer in a WPC. Composites were produced from different wood species and analyzed using SEM (scanning electron microscopy). Results showed that wood species with high interfac (more) ial areas may increase mechanical interlocking, reflected in the viscous constant of the Maxwell model. A complicating factor is that the relation of cell wall thickness-lumen diameter and the interconnectivity between wood cells in a wood, affect the potential for cell collapse. When wood cells collapse, the penetration of the thermoplastic into the wood structure is almost always ceased. The collapse of wood cells during extrusion-injection molding processes reduced ...

2009-01-01

Future limits on isotropic Lorentz violation in the photon sector from UHECRs and TeV gamma rays

Experimental electrochemical capacitor test results

Present and future ultra-high-energy-cosmic-ray facilities (e.g., the Pierre Auger Observatory with South and North components) and TeV-gamma-ray telescope arrays (e.g., HESS/VERITAS and CTA) have the potential to set stringent indirect bounds on the nine Lorentz-violating parameters of nonbirefringent modified Maxwell theory minimally coupled to standard Dirac theory. Theoretically, the most interesting case is isotropic Lorentz violation, which is described by a single parameter [taken to vanish for the case of the standard Lorentz-invariant theory]. It appears possible to obtain in the future an upper (lower) indirect bound on this single isotropic Lorentz-violating parameter at the +10^{-21} (-10^{-17}) level. Comparison is made with existing and future direct bounds from laboratory experiments. The possible physics implications of upper bounds at the 10^{-21} level are also briefly discussed.

2011-01-01

Electric-field-induced deformation of biological cells

Various electrochemical capacitors (ultracapacitors) are being developed for hybrid vehicles as candidate power assist devices for the fast response engine. The primary functions of the ultracapacitor are to level the dynamic power loads on the primary propulsion device and recover available energy from regenerative breaking during off-peak power periods. Ultracapacitors show promise toward being able to accept high regenerative pulses while exhibiting very high cycle life. This paper will present test data from selected US Department of Energy (DOE) supported ultracapacitor projects designed to meet the fast response engine requirements. Devices containing carbon, conducting polymers, and metal oxide electrode materials in combination with aqueous or organic electrolytes are being supported by the DOE. This paper will present and discuss testing data obtained from recent prototype capacitors supplied by Maxwell Energy Products, Inc., SAFT America, Inc., Federal ...

1997-11-01

The Euro-Quebec Hydro-Hydrogen Pilot Project (EQHHPP). Rationale, concept, realisation

The cell is modeled as an ellipsoid with shell and the surface stress distribution calculated by means of the Maxwell Stress Tensor. The cell membrane is treated as incompressible material having both bending and shear energies of deformation. Employing the principle of virtual work, cell volume (and hence shape) is computed as a function of the external field strength and orientation with respect to the field. The following results were obtained: (1) The surface stresses that develop or the cell membrane are distributed having both normal and tangential components that act together to produce a rounding of the cell. (2) If the tangential component of the stress is ignored, then higher field strengths are needed to produce similar deformation (shape change) of cells. (3) The threshold value of the applied field, i.e, the field strength at which the volume (shape) of the cell changes abruptly, occurs at approximately 55V/cm. Above the threshold value further ...

1989-01-01

LOOP Inc. (Louisiana Offshore Oil Port Inc. ) to start onshore construction this year

Back in 1985 it was the European Commission's intention to demonstrate on rather large scale the provision of clean and renewable energy with hydrogen as energy vector and fuel. The cheapest and technologically available form of renewable electricity, the primary energy for electrolytic hydrogen, is hydropower. Most of the hydroenergy sources are oversea's. The World's topologically and technically exploitable hydroenergy potential is estimated to be in the order of 20.10{sup 3} TWh/y, i.e. 0.0057% of the hydraulic cycle energy. Today's hydroelectricity generation is {approx}2500 TWh/y i.e. {approx}21% of the World's electricity generation. Quebec's installed hydroelectricity is 33.5 GW, its residual potential is 50 GW or 190 TWh/y and 285 TWh/y, respectively (load factor 0.65). The construction of hydropower installation is rather clean. The construction of La Grande at James Bay with an installed rating of ...

1998-07-01

International Safeguards Technology and Policy Education and Training Pilot Programs

A discussion covers the LOOP project to construct an offshore pipeline system, which will connect with onshore facilities at Fourchon, La., and two onshore pipelines (26 mi 48 in. Clovelly line and 53 mi 48 in. LOCAP line) connecting Fourchon with the existing Capline system at St. James, La.; the three-phase construction schedule, the first phase due to begin in the third quarter of 1978 with, e.g., onshore pipeline and salt dome storage facility construction which will yield an expected initial throughput of 1.4 million bbl/day; the marine terminal complex, consisting of control and pumping platforms, and three 7000 hp pumps to operate the system at 45,000-100,000 bbl/hr; the offshore lines, including lines between single-point mooring units and the pumping platform, the 21 mi 48 in. pipe to Fourchon, and corrosion protection of lines by an asphalt-sand mixture or a semiplasticized coal-tar enamel; the onshore system, including the Fourchon booster station, ...

1978-06-01

On the Gravito-Electromagnetic Analogy

A major focus of the National Nuclear Security Administration-led Next Generation Safeguards Initiative (NGSI) is the development of human capital to meet present and future challenges to the safeguards regime. An effective university-level education in safeguards and related disciplines is an essential element in a layered strategy to rebuild the safeguards human resource capacity. NNSA launched two pilot programs in 2008 to develop university level courses and internships in association with James, Martin Center for Nonproliferation Studies (CNS) at the Monterey Institute of International Studies (MIIS) and Texas A&M University (TAMU). These pilot efforts involved 44 students in total and were closely linked to hands-on internships at Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). The Safeguards and Nuclear Material Management pilot program was a collaboration between TAMU, LANL, and LLNL. The LANL-based ...

2009-06-16

New Forming Limits For Light Alloys By Means Of Electromagnetic Forming And Numerical Simulation Of The Process

Earlier research by Zel'manov and by Hoenl and Dehnen has shown how the geodesic equation for a charged test particle can be written as a Lorentz force law in which the four-velocity u"i of an observer in the physical three-space #gamma#_#alpha#_#beta# = -g_#alpha#_#beta# + g_0_#alpha# g_0_#beta# / g_0_0 is regarded as a gravitational vector potential. Analysing this analogy further, we write the four ("i_0) components of the Einstein equations in a form resembling a non-linear Maxwell system, which, for a stationary field, is most clearly understood from the Kaluza-Klein perspective, the projection being from four dimensions to three, rather than from five dimensions to four. For the vacuum theory defined by vanishing energy-momentum tensor, T_i_j = 0, these equations exhibit the structure of a non-linear sigma model, found by Ernst, and investigated by Gibbons and Hawking and by Sanchez, the scalar potentials of which we here relate to the gravito-electromagnetic ...

2011-08-01

New Forming Limits For Light Alloys By Means Of Electromagnetic Forming And Numerical Simulation Of The Process

It is well known that one of the main advantages of the high speed forming (HSF) processes is the improvement in the forming limits of the used materials.Using the Electromagnetic Forming (EMF) technology two materials have been tested with different mechanical and physical properties: the AA5754 aluminium and the AZ31B magnesium alloys.The EMF process principle can be described as follows: A significant amount of electrical energy is stored in a bank of capacitors which are suddenly discharged releasing all the stored energy. This electric discharge runs through a coil which generates an intense transient magnetic field. At the same time transient Eddy currents are induced in the electrically conductive part placed some millimetres far from the coil. Another intense magnetic field is generated due to those Eddy currents but on the opposite direction as the one generated by the coil. A big magnetic repulsion force is created between the part and the coil. This magnetic repulsion ...

2007-04-07

Heat transfer augmentation using a magnetic fluid under the influence of a line dipole

2007-04-07

Heat transfer augmentation using a magnetic fluid under the influence of a line dipole

Ferrofluids have promising potential for heat transfer applications, since advective transport in a ferrofluid can be readily controlled by using an external magnetic field. However, unlike conventional free or forced convection, ferrohydrodynamic convection is not yet well characterized. A full understanding of the relationship between an imposed magnetic field, the resulting ferrofluid flow, and the temperature distribution is a prerequisite for the proper design and implementation of applications involving thermomagnetic convection. The literature variously assumes constant magnetic fields, does not completely represent the variation in the imposed field, or its descriptions are inaccurate, since the fields do not comply with the Maxwell's equations of electromagnetism. We address this by simulating two-dimensional forced convection heat transfer in a channel with a ferrofluid that is under the influence of a two-dimensional magnetic field created by a ...

2004-04-01

Exact and variational calculations of eigenmodes for three-dimensional free electron laser interaction with a warm electron beam

2004-04-01

Development of a 3-D model for eddy current testing: application for fastened structures in aeronautics; Developpement d'un modele pour le controle non destructif par courants de Foucault de structures rivetees en aeronautique

I present an exact calculation of free-electron-laser (FEL) eigenmodes (fundamental as well as higher order modes) in the exponential-gain regime. These eigenmodes specify transverse profiles and exponential growth rates of the laser field, and they are self-consistent solutions of the coupled Maxwell-Vlasov equations describing the FEL interaction taking into account the effects due to energy spread, emittance and betatron oscillations of the electron beam, and diffraction and guiding of the laser field. The unperturbed electron distribution is assumed to be of Gaussian shape in four dimensional transverse phase space and in the energy variable, but uniform in longitudinal coordinate. The focusing of the electron beam is assumed to be matched to the natural wiggler focusing in both transverse planes. With these assumptions the eigenvalue problem can be reduced to a numerically manageable integral equation and solved exactly with a kernel iteration method. An ...

1995-08-21

Computer modelling of eddy current probes for ISI of pressure tube/calandria tube assemblies in PHWRs

One of the Eddy Current Testing issues in aeronautics is the inspection of fastened structures to detect flaws nearby rivets which can grow because of mechanical stress. EADS and the CEA LIST have started a collaborative work with the support of the Ile-de-France Region to develop a simulation tool of EC fastened structures testing, integrated to the CIVA platform, aimed at conceiving testing methods, optimizing and qualifying it. The volume integral method using the Green dyadics formalism has been chosen in order to get a fast resolution of Maxwell equations. A first milestone was to build a simulation model of multilayer structures testing, thanks to the use of the multilayer Green dyads. Because of the rivet volume, 60 times bigger than the one of a typical flaw, a large number of discretization cells are needed. Therefore an iterative method has been developed in order to numerically solve large calculation zones. Finally, the flaw response simulation mostly ...

2007-12-15

Coal compilation project - entrance NTS 83F/5

Non-destructive Evaluation (NDE) plays a major role in ensuring the safe and reliable operation of PHWRs which are the mainstay of India's nuclear power programme. An important in-service inspection (ISI) requirement in these reactors is carried out through Eddy Current Testing (ECT) of the pressure tube (PT)/calandria tube (CT) assemblies. The material of construction of these assemblies is zircaloy-2. The two main objectives of this ISI are the detection of garter spring between CT and PT and the profiling of gap between CT and PT. The paper discusses the work carried out at the authors' laboratory on the development of ECT probes for ISI of PT/CT assemblies. Emphasis has been given on the work done on the design and optimisation of the probes using computer modeling. A 2-D finite element code has been developed for this purpose. The code is developed around a diffusion equation which can be derived from Maxwell's equations governing the electromagnetic ...

1991-12-01