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1

Electromagnets  

NSDL National Science Digital Library

This is an activity about the properties of electromagnets, which is a crucial underpinning for understanding how magnetic fields are generated in nature, in the surface of the Sun, and in the interior of Earth. Learners will create an electromagnet by letting an electric current flow through a wire to generate a magnetic field, which is then detected using a compass. This activity requires a thin insulated wire, pencil, battery, compass and paper clips. This is Activity 2 of the Magnetism and Electromagnetism teachers guide.

2

Electromagnets  

NSDL National Science Digital Library

In this investigation, students will construct electromagnets and test to see which variables make them stronger. Although elementary and middle school teachers are expected to have done this activity with their classes, teachers of younger students often

Horton, Michael

2009-05-30

3

Electromagnets  

NSDL National Science Digital Library

In this activity, the students will complete the grand challenge and design an electromagnet to separate steel from aluminum for the recycler. In order to do this, students compare the induced magnetic field of an electric current with the magnetic field of a permanent magnet and must make the former look like the latter. They discover that looping the current produces the desired effect and find ways to further strengthen the magnetic field.

Vu Bioengineering Ret Program

4

Electromagnetic fasteners  

Microsoft Academic Search

An electromagnetic fastener for manipulating objects in space uses the matic attraction of various metals. An end effector is attached to a robotic manipulating system having an electromagnet such that when current is supplied to the electromagnet, the object is drawn and affixed to the end effector, and when the current is withheld, the object is released. The object to

Randolph W. Crane; Donna J. Marts

1994-01-01

5

Virtual Electromagnet  

NSDL National Science Digital Library

This is an interactive online activity, in which learners equip a virtual electromagnet and see how many iron filings it can pick up. Learners change various characteristics of the electromagnet including the number of windings, the gage of the wire, the current type (AC or DC), the material used in the wire, and the voltage on the power supply.

The University of California Regents

2014-01-01

6

Electromagnetic Attraction.  

ERIC Educational Resources Information Center

Three activities involving electromagnetism are presented. Discussed are investigations involving the construction of an electromagnet, the effect of the number of turns of wire in the magnet, and the effect of the number of batteries in the circuit. Extension activities are suggested. (CW)

Milson, James L.

1990-01-01

7

Electromagnetic fasteners  

DOEpatents

An electromagnetic fastener for manipulating objects in space uses the matic attraction of various metals. An end effector is attached to a robotic manipulating system having an electromagnet such that when current is supplied to the electromagnet, the object is drawn and affixed to the end effector, and when the current is withheld, the object is released. The object to be manipulated includes a multiplicity of ferromagnetic patches at various locations to provide multiple areas for the effector on the manipulator to become affixed to the object. The ferromagnetic patches are sized relative to the object's geometry and mass.

Crane, Randolph W. (Idaho Falls, ID); Marts, Donna J. (Idaho Falls, ID)

1994-01-01

8

Electromagnetic Theory 1 /56 Electromagnetic Theory  

E-print Network

Electromagnetic Theory 1 /56 Electromagnetic Theory Summary: · Maxwell's equations · EM Potentials · Equations of motion of particles in electromagnetic fields · Green's functions · Lienard-Weichert potentials · Spectral distribution of electromagnetic energy from an arbitrarily moving charge #12;Electromagnetic

Bicknell, Geoff

9

Electromagnetic Geometry  

E-print Network

We show that Maxwell's electromagnetism can be mapped into the Born-Infeld theory in a curved space-time, which depends only on the electromagnetic field in a specific way. This map is valid for any value of the two lorentz invariants $F$ and $G$ confirming that we have included all possible solutions of Maxwell's equations. Our result seems to show that specifying the dynamics and the space-time structure of a given theory can be viewed merely as a choice of representation to describe the physical system.

M. Novello; F. T. Falciano; E. Goulart

2011-11-08

10

Electromagnet Lesson  

NSDL National Science Digital Library

This hands-on classroom activity will help students understand the connections between magnets and electricity generation. The learning cycle planner includes an exploration phase with a hands-on activity and a suggested video. The concept development phase suggests showing the film "Who Killed the Electric Car?" The main part of this learning unit is the electromagnet lesson, which is a two day small group activity in which students will create an electromagnet. This document may be downloaded in PDF file format; student worksheets are included.

Orzali, Joe

2011-12-08

11

Electromagnetic Survey  

USGS Multimedia Gallery

USGS hydrologist conducts a broadband electromagnetic survey in New Orleans, Louisiana. The survey was one of several geophysical methods used during USGS applied research on the utility of the multi-channel analysis of surface waves (MASW) seismic method for non-invasive assessment of earthen levee...

12

Electromagnetic Survey  

USGS Multimedia Gallery

A USGS hydrologist conducts a near-surface electromagnetic induction survey to characterize the shallow earth. The survey was conducted as part of an applied research effort by the USGS Office of Groundwater Branch of Geophysics at Camp Rell, Connecticut, in 2008....

13

Electromagnetic Reciprocity.  

SciTech Connect

A reciprocity theorem is an explicit mathematical relationship between two different wavefields that can exist within the same space - time configuration. Reciprocity theorems provi de the theoretical underpinning for mod ern full waveform inversion solutions, and also suggest practical strategies for speed ing up large - scale numerical modeling of geophysical datasets . In the present work, several previously - developed electromagnetic r eciprocity theorems are generalized to accommodate a broader range of medi um, source , and receiver types. Reciprocity relations enabling the interchange of various types of point sources and point receivers within a three - dimensional electromagnetic model are derived. Two numerical modeling algorithms in current use are successfully tested for adherence to reciprocity. Finally, the reciprocity theorem forms the point of departure for a lengthy derivation of electromagnetic Frechet derivatives. These mathe matical objects quantify the sensitivity of geophysical electromagnetic data to variatio ns in medium parameters, and thus constitute indispensable tools for solution of the full waveform inverse problem. ACKNOWLEDGEMENTS Sandia National Labor atories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000. Signif icant portions of the work reported herein were conducted under a Cooperative Research and Development Agreement (CRADA) between Sandia National Laboratories (SNL) and CARBO Ceramics Incorporated. The author acknowledges Mr. Chad Cannan and Mr. Terry Pa lisch of CARBO Ceramics, and Ms. Amy Halloran, manager of SNL's Geophysics and Atmospheric Sciences Department, for their interest in and encouragement of this work. Special thanks are due to Dr . Lewis C. Bartel ( recently retired from Sandia National Labo ratories and now a geophysical consultant ) and Dr. Chester J. Weiss (recently rejoined with Sandia National Laboratories) for many stimulating (and reciprocal!) discussions regar ding the topic at hand.

Aldridge, David F.

2014-11-01

14

Creating an Electromagnet  

NSDL National Science Digital Library

Student teams investigate the properties of electromagnets. They create their own small electromagnet and experiment with ways to change its strength to pick up more paper clips. Students learn about ways that engineers use electromagnets in everyday applications.

Integrated Teaching And Learning Program

15

Electromagnetic topology: Characterization of internal electromagnetic coupling  

NASA Technical Reports Server (NTRS)

The main principles are presented of a method dealing with the resolution of electromagnetic internal problems: Electromagnetic Topology. A very interesting way is to generalize the multiconductor transmission line network theory to the basic equation of the Electromagnetic Topology: the BLT equation. This generalization is illustrated by the treatment of an aperture as a four port junction. Analytical and experimental derivations of the scattering parameters are presented. These concepts are used to study the electromagnetic coupling in a scale model of an aircraft, and can be seen as a convenient means to test internal electromagnetic interference.

Parmantier, J. P.; Aparicio, J. P.; Faure, F.

1991-01-01

16

Electromagnetic Field Theory  

E-print Network

Electromagnetic Field Theory BO THID? UPSILON BOOKS #12;#12;ELECTROMAGNETIC FIELD THEORY #12;#12;Electromagnetic Field Theory BO THID? Swedish Institute of Space Physics and Department of Astronomy and Space, Sweden UPSILON BOOKS · COMMUNA AB · UPPSALA · SWEDEN #12;Also available ELECTROMAGNETIC FIELD THEORY

Hart, Gus

17

7. Electromagnetic relations 1 7. ELECTROMAGNETIC RELATIONS  

E-print Network

7. Electromagnetic relations 1 7. ELECTROMAGNETIC RELATIONS Revised September 2005 by H.G. Spieler = 10-7 N A-2 ; c = 1 0 0 = 2.997 924 58 ? 108 m s-1 #12;2 7. Electromagnetic relations 7.1. Impedances of self-inductance L: Z = jL . Impedance of capacitance C: Z = 1/jC . Impedance of free space: Z = 0/ 0

18

Electromagnetic induction methods  

Technology Transfer Automated Retrieval System (TEKTRAN)

Electromagnetic induction geophysical methods are finding greater and greater use for agricultural purposes. Electromagnetic induction methods measure the electrical conductivity (or resistivity) for a bulk volume of soil directly beneath the surface. An instrument called a ground conductivity meter...

19

Electromagnetic properties of neutrinos  

E-print Network

A short review on electromagnetic properties of neutrinos is presented. In spite of many efforts in the theoretical and experimental studies of neutrino electromagnetic properties, they still remain one of the main puzzles related to neutrinos.

Carlo Giunti; Alexander Studenikin

2010-06-08

20

Electromagnetic Abdulaziz Hanif  

E-print Network

Electromagnetic Propulsion Abdulaziz Hanif Electrical Engineering Department King Fahd University of spacecraft, which would be jolted through space by electromagnets, could take us farther than any of these other methods. When cooled to extremely low temperatures, electromagnets demonstrate an unusual behavior

Masoudi, Husain M.

21

Electromagnetic Measurements at RHIC  

E-print Network

Electromagnetic Measurements at RHIC Hideki Hamagaki Center for Nuclear Study University of Tokyo #12;2/10/2005 "Electromagnetic measurements at RHIC"@ICPAQGP 05 Hideki Hamagaki 2 Prologue · EM probe and where they are produced; #12;2/10/2005 "Electromagnetic measurements at RHIC"@ICPAQGP 05 Hideki Hamagaki

Hamagaki, Hideki

22

Electromagnetic Measurements at RHIC  

E-print Network

Electromagnetic Measurements at RHIC Hideki Hamagaki Center for Nuclear Study Graduate School of Science the University of Tokyo #12;2006/06/29 "Electromagnetic measurements at RHIC"@ATHIC 2006 Hideki;2006/06/29 "Electromagnetic measurements at RHIC"@ATHIC 2006 Hideki Hamagaki 3 Prologue ­ scope of EM measurements · EM

Hamagaki, Hideki

23

Electromagnetic Radiation: On Trial  

NSDL National Science Digital Library

This activity introduces students to the properties of electromagnetic radiation in a variety of ways. For example, they put the different types of the electromagnetic radiation on trial, selecting the judge, prosecutor, defense counsel, and jury, and learning about electromagnetic energy by arguing the pros and cons of each wavelength. During this activity, students are introduced to the general properties of electromagnetic waves, learn to analyze the relation between the specific properties of waves and their position in the electromagnetic spectrum, and discuss methods used to detect and analyze different waves. Students also learn about scientists whose work contributed to our understanding of electromagnetic energy. Students are encouraged to use an electronic bulletin board to communicate with each other, posting insights, ideas, evidence and questions on electromagnetic energy.

24

Electromagnetic structure of pion  

SciTech Connect

In this work, we analyze the electromagnetic structure of the pion, an elementary particle composed by a quark-antiquark bound state, by considering the calculation of its electromagnetic radius and its electromagnetic form factor in low and intermediate energy range. Such observables are determined by means of a theoretical model that takes into account the constituent quark and antiquark of the pion, in the formalism of the light-front field theory. In particular, it is considered a nonsymmetrical vertex for such a model, in which we have calculated the electromagnetic form factor of the pion in an optimized way, by varying its regulator mass, so that we can obtain the best value for the pion electromagnetic radius when compared with the experimental one. The theoretical calculations are also compared with the most recent experimental data involving the pion electromagnetic form factor and the results show very good agreement.

Mello, Clayton S.; Cruz Filho, Jose P.; Da Silva, Edson O.; El-Bennich, Bruno; De Melo, J. P.; Filho, Victo S. [Laboratorio de Fisica Teorica e Computacional (LFTC), Universidade Cruzeiro do Sul, 01506-000, Sao Paulo (Brazil)

2013-03-25

25

8.07 Electromagnetism II, Fall 2002  

E-print Network

Survey of basic electromagnetic phenomena: electrostatics, magnetostatics; electromagnetic properties of matter. Time-dependent electromagnetic fields and Maxwell's equations. Electromagnetic waves, emission, absorption, ...

Zwiebach, Barton

26

Exploring the Electromagnetic Spectrum  

NSDL National Science Digital Library

Students learn the basics of the electromagnetic spectrum and how various types of electromagnetic waves are related in terms of wavelength and energy. In addition, they are introduced to the various types of waves that make up the electromagnetic spectrum including, radio waves, ultraviolet waves, visible light and infrared waves. These topics help inform students before they turn to designing solutions to an overarching engineering challenge question.

2014-09-18

27

"Hearing" Electromagnetic Waves  

NASA Astrophysics Data System (ADS)

In this work, an educational experience is described in which a microwave communication link is used to make students aware that all electromagnetic waves have the same physical nature and properties. Experimental demonstrations are linked to theoretical concepts to increase comprehension of the physical principles underlying electromagnetic waves. Moreover, students learn about the importance and historical development of communication systems, the basic principles of communication links, and the procedure to send information through an electromagnetic wave.1,2

Rojo, Marta; Muoz, Juan

2014-12-01

28

Meson electromagnetic form factors  

E-print Network

The electromagnetic structure of the pseudoscalar meson nonet is completely described by the sophisticated Unitary&Analytic model, respecting all known theoretical properties of the corresponding form factors.

Stanislav Dubnicka; Anna Z. Dubnickova

2012-10-23

29

How Strong are Electromagnets?  

NSDL National Science Digital Library

This is an activity about electromagnetism. Using a battery and a length of wire, learners will construct an electromagnet and investigate the number of paperclips the electromagnet can hold for an electromagnet with twenty loops of wire versus one with forty loops of wire. A six to twelve volt battery, a large nail or metal rod, and insulated wire are required for this activity. This is the fourth activity in the Exploring the Earth's Magnetic Field: An IMAGE Satellite Guide to the Magnetosphere educators guide.

30

NISTHB 150-11 Electromagnetic  

E-print Network

NISTHB 150-11 NVLAP Electromagnetic Compatibility and Telecommunications Bethany Hackett Bradley. #12;NISTHB 150-11 NVLAP Electromagnetic Compatibility and Telecommunications Bethany Hackett Bradley Programs Dennis Camell Electromagnetics Division Physical Measurement Laboratory http://dx.doi.org/10

31

Building an Electromagnet  

NSDL National Science Digital Library

Students design and construct an electromagnet that must pick up 10 staples. They begin with only minimal guidance, and after the basic concept is understood, are informed of the properties that affect the strength of that magnet. They conclude by designing their own electromagnet to complete the challenge of separating scrap steel from scrap aluminum for recycling and share it with the class.

Vu Bioengineering Ret Program

32

Electromagnetic Wave Dynamics in  

E-print Network

possibilities for strong localization of electromagnetic radiation in a dense and ultracold atomic gas sample the localization of light in ultracold samples of gas-phase Rb atoms has, until now, been focused on lightMesoscopic Electromagnetic Wave Dynamics in Ultracold Atomic Gases Robin Kaiser and Mark D. Havey

33

The Electromagnetic Spectrum  

NSDL National Science Digital Library

This tutorial introduces students to the concepts of electromagnetic waves, wavelength, and the electromagnetic spectrum. Diagrams and written descriptions explain how wavelength is measured and explore the traditional divisions of the spectrum: radio, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

34

Electromagnetic Analysis: Concrete Results  

Microsoft Academic Search

Abstract Although the possibility of attacking smart - cards by analyz - ing their electromagnetic power radiation repeatedly appears in research papers, all accessible references evade the essence of reporting conclusive experiments where actual cryptographic algorithms such as des or rsa were successfully attacked This work describes electromagnetic experiments conducted on three dif - ferent cmos chips, featuring di erent

Karine Gandolfi; Christophe Mourtel; Francis Olivier

2001-01-01

35

The Electromagnetic Spectrum  

NSDL National Science Digital Library

This is a lesson about the electromagnetic spectrum. Learners will read two pages of information about the electromagnetic spectrum and answer questions in an accompanying worksheet. This activity is from the Stanford Solar Center's All About the Sun: Sun and Stars activity guide for Grades 5-8 and can also accompany the Stanford Solar Center's Build Your Own Spectroscope activity.

36

SMILE Lab: Electromagnets  

NSDL National Science Digital Library

This site contains instructions for a fairly simple lab or demonstration using electromagnets. The electromagnets are made with nails, copper wire, and batteries. The lab includes a list of needed materials, the procedure that the students should follow, and a brief discussion of the physical concepts involved.

Johnson, Porter

2006-07-18

37

Introducing Electromagnetic Field Momentum  

ERIC Educational Resources Information Center

I describe an elementary way of introducing electromagnetic field momentum. By considering a system of a long solenoid and line charge, the dependence of the field momentum on the electric and magnetic fields can be deduced. I obtain the electromagnetic angular momentum for a point charge and magnetic monopole pair partially through dimensional

Hu, Ben Yu-Kuang

2012-01-01

38

Electromagnetic interference in balanced converters .  

E-print Network

??In this dissertation, an investigation into reducing Electromagnetic Interference (EMI) through design is presented. Root generation mechanisms of Electromagnetic Interference are often neglected during the (more)

Burford, Steven Trefor

2014-01-01

39

I. What is electromagnetic radiation and the electromagnetic spectrum?  

E-print Network

i­1 I. What is electromagnetic radiation and the electromagnetic spectrum? What do light, X effects on matter. This "stuff" is called electromagnetic radiation, because it travels (radiates) and has electrical and magnetic effects. Electromagnetic radiation is the means for many of our interactions

Sitko, Michael L.

40

Microslots : scalable electromagnetic instrumentation  

E-print Network

This thesis explores spin manipulation, fabrication techniques and boundary conditions of electromagnetism to bridge the macroscopic and microscopic worlds of biology, chemistry and electronics. This work is centered around ...

Maguire, Yael G., 1975-

2004-01-01

41

The classical geometrization electromagnetism  

E-print Network

Following the line of the history, if by one side the electromagnetic theory was consolidated on the 19th century, the emergence of the special and the general relativity theories on the 20th century opened possibilities of further developments, with the search for the unification of the gravitation and the electromagnetism on a single unified theory. Some attempts to the geometrization of the electromagnetism emerged in this context, where these first models resided strictly on a classical basis. Posteriorly, they were followed by more complete and embracing quantum field theories. The present work reconsiders the classical viewpoint, with the purpose of showing that in a first order of approximation the electromagnetism constitutes a geometric structure aside other phenomena as gravitation. Even though being limited, the model is consistent and offers the possibility of an experimental test of validity.

C. A. Duarte

2015-02-11

42

Inverse problems in electromagnetics  

E-print Network

Two inverse problems in electromagnetics are investigated in this thesis. The first is the retrieval of the effective constitutive parameters of metamaterials from the measurement of the reflection and the transmission ...

Chen, Xudong, 1977-

2005-01-01

43

Electromagnetism in the Movies.  

ERIC Educational Resources Information Center

Describes how the authors used portions of popular movies to help students review concepts related to electromagnetism. Movies used and concepts covered in the review are listed, and a sample activity is described. (WRM)

Everitt, Lori R.; Patterson, Evelyn T.

1999-01-01

44

Purely electromagnetic spacetimes  

E-print Network

Electrovacuum solutions devoid of usual mass sources are classified in the case of one, two and three commuting Killing vectors. Three branches of solutions exist. Electromagnetically induced mass terms appear in some of them.

B. V. Ivanov

2007-12-15

45

An opening electromagnetic transducer  

NASA Astrophysics Data System (ADS)

Tubular solenoids have been widely used without any change since an electrical wire was discovered to create magnetic fields by Hans Christian Oersted in 1820 and thereby the wire was first coiled as a helix into a solenoid coil by William Sturgeon in 1823 and was improved by Joseph Henry in 1829 [see http://www.myetymology.com/encyclopedia/History_of_the_electricity.html; J. M. D. Coey, Magnetism and Magnetic Materials (Cambridge University Press, New York, 2010); and F. Winterberg, Plasma Phys. 8, 541553 (1996)]. A magnetic control method of C-shaped carrying-current wire is proposed, and thereby a new opening electromagnetic transducer evidently differing from the traditional tubular solenoid is created, capable of directly encircling and centering the acted objects in it, bringing about convenient and innovative electromagnetic energy conversion for electromagnetic heating, electromagnetic excitation, physical information capture, and electro-mechanical motion used in science research, industry, and even biomedical activities.

Sun, Yanhua; Kang, Yihua

2013-12-01

46

Electromagnetic rotational actuation.  

SciTech Connect

There are many applications that need a meso-scale rotational actuator. These applications have been left by the wayside because of the lack of actuation at this scale. Sandia National Laboratories has many unique fabrication technologies that could be used to create an electromagnetic actuator at this scale. There are also many designs to be explored. In this internship exploration of the designs and fabrications technologies to find an inexpensive design that can be used for prototyping the electromagnetic rotational actuator.

Hogan, Alexander Lee

2010-08-01

47

Electromagnetic properties of baryons  

SciTech Connect

We discuss the chiral behavior of the nucleon and {Delta}(1232) electromagnetic properties within the framework of a SU(2) covariant baryon chiral perturbation theory. Our one-loop calculation is complete to the order p{sup 3} and p{sup 4}/{Delta} with {Delta} as the {Delta}(1232)-nucleon energy gap. We show that the magnetic moment of a resonance can be defined by the linear energy shift only when an additional relation between the involved masses and the applied magnetic field strength is fulfilled. Singularities and cusps in the pion mass dependence of the {Delta}(1232) electromagnetic moments reflect a non-fulfillment. We show results for the pion mass dependence of the nucleon iso-vector electromagnetic quantities and present preliminary results for finite volume effects on the iso-vector anomalous magnetic moment.

Ledwig, T.; Pascalutsa, V.; Vanderhaeghen, M. [Institut fuer Kernphysik, Universitaet Mainz, D-55099 Mainz (Germany); Martin-Camalich, J. [Departamento de Fisica Teorica and IFIC, Universidad de Valencia-CSIC, Spain and Department of Physics and Astronomy, University of Sussex, BN1 9Qh, Brighton (United Kingdom)

2011-10-21

48

Aircraft electromagnetic compatibility  

NASA Technical Reports Server (NTRS)

Illustrated are aircraft architecture, electromagnetic interference environments, electromagnetic compatibility protection techniques, program specifications, tasks, and verification and validation procedures. The environment of 400 Hz power, electrical transients, and radio frequency fields are portrayed and related to thresholds of avionics electronics. Five layers of protection for avionics are defined. Recognition is given to some present day electromagnetic compatibility weaknesses and issues which serve to reemphasize the importance of EMC verification of equipment and parts, and their ultimate EMC validation on the aircraft. Proven standards of grounding, bonding, shielding, wiring, and packaging are laid out to help provide a foundation for a comprehensive approach to successful future aircraft design and an understanding of cost effective EMC in an aircraft setting.

Clarke, Clifton A.; Larsen, William E.

1987-01-01

49

Electromagnetic particle simulation codes  

NASA Technical Reports Server (NTRS)

Electromagnetic particle simulations solve the full set of Maxwell's equations. They thus include the effects of self-consistent electric and magnetic fields, magnetic induction, and electromagnetic radiation. The algorithms for an electromagnetic code which works directly with the electric and magnetic fields are described. The fields and current are separated into transverse and longitudinal components. The transverse E and B fields are integrated in time using a leapfrog scheme applied to the Fourier components. The particle pushing is performed via the relativistic Lorentz force equation for the particle momentum. As an example, simulation results are presented for the electron cyclotron maser instability which illustrate the importance of relativistic effects on the wave-particle resonance condition and on wave dispersion.

Pritchett, P. L.

1985-01-01

50

Electromagnetic propulsion test facility  

NASA Technical Reports Server (NTRS)

A test facility for the exploration of electromagnetic propulsion concept is described. The facility is designed to accommodate electromagnetic rail accelerators of various lengths (1 to 10 meters) and to provide accelerating energies of up to 240 kiloJoules. This accelerating energy is supplied as a current pulse of hundreds of kiloAmps lasting as long as 1 millisecond. The design, installation, and operating characteristics of the pulsed energy system are discussed. The test chamber and its operation at pressures down to 1300 Pascals (10 mm of mercury) are described. Some aspects of safety (interlocking, personnel protection, and operating procedures) are included.

Gooder, S. T.

1984-01-01

51

Improved Electromagnetic Brake  

NASA Technical Reports Server (NTRS)

A proposed design for an electromagnetic brake would increase the reliability while reducing the number of parts and the weight, relative to a prior commercially available electromagnetic brake. The reductions of weight and the number of parts could also lead to a reduction of cost. A description of the commercial brake is prerequisite to a description of the proposed electromagnetic brake. The commercial brake (see upper part of figure) includes (1) a permanent magnet and an electromagnet coil on a stator and (2) a rotor that includes a steel contact plate mounted, with tension spring loading, on an aluminum hub. The stator is mounted securely on a stationary object, which would ordinarily be the housing of a gear drive or a motor. The rotor is mounted on the shaft of the gear drive or motor. The commercial brake nominally operates in a fail-safe (in the sense of normally braking) mode: In the absence of current in the electromagnet coil, the permanent magnet pulls the contact plate, against the spring tension, into contact with the stator. To release the brake, one excites the electromagnet with a current of the magnitude and polarity chosen to cancel the magnetic flux of the permanent magnet, thereby enabling the spring tension to pull the contact plate out of contact with the stator. The fail-safe operation of the commercial brake depends on careful mounting of the rotor in relation to the stator. The rotor/stator gap must be set with a tolerance between 10 and 15 mils (between about 0.25 and about 0.38 mm). If the gap or the contact pad is thicker than the maximum allowable value, then the permanent magnetic field will not be strong enough to pull the steel plate across the gap. (For this reason, any contact pad between the contact plate and the stator must also be correspondingly thin.) If the gap exceeds the maximum allowable value because of shaft end play, it becomes impossible to set the brake by turning off the electromagnet current. Although it may still be possible to set the brake by applying an electromagnet current to aid the permanent magnetic field instead of canceling it, this action can mask an out-of-tolerance condition in the brake and it does not restore the fail-safe function of setting the brake when current is lost.

Martin, Toby B.

2004-01-01

52

Electromagnetic power absorber  

NASA Technical Reports Server (NTRS)

A structure is presented with a surface portion of dielectric material which passes electromagnetic radiation and with a portion below the surface which includes material that absorbs the radiation, the face of the structure being formed with numerous steep ridges. The steepness of the dielectric material results in a high proportion of the electromagnetic energy passing through the surface for absorption by the absorbing material under the surface. A backing of aluminum or other highly heat-conductive and reflective material lies under the face and has very steep protuberances supporting the absorbing and dielectric materials.

Iwasaki, R. S. (inventor)

1979-01-01

53

3. ELECTROMAGNETIC COMPATIBILITY Abstract --The electromagnetic interference between the  

E-print Network

3. ELECTROMAGNETIC COMPATIBILITY Abstract -- The electromagnetic interference between the electromagnetic fields in 3D, assuming that the field is computed outside a sphere of radius r that contains impedance of the considered environment. - and are the magnetic and electric multipoles, respectively

Paris-Sud XI, Université de

54

Canceling Electromagnetic Interference During Tests  

NASA Technical Reports Server (NTRS)

Old technique solves modern problem. Simple amplitude-and-phase-cancellation technique removes strong electromagnetic interference from received test signal, enabling recovery of relatively weak signal from device under test. Useful in outdoor tests of devices for electromagnetic compatibility.

Robinson, Paul A., Jr.; Edmonds, Larry D.

1988-01-01

55

8.07 Electromagnetism II, Fall 2005  

E-print Network

This course is the second in a series on Electromagnetism beginning with Electromagnetism I (8.02 or 8.022). It is a survey of basic electromagnetic phenomena: electrostatics; magnetostatics; electromagnetic properties of ...

Bertschinger, Edmund

56

Electromagnetic Radiation REFERENCE: Remote Sensing of  

E-print Network

1 CHAPTER 2: Electromagnetic Radiation Principles REFERENCE: Remote Sensing of the Environment John;2 Electromagnetic Energy Interactions Energy recorded by remote sensing systems undergoes fundamental interactions, creating convectional currents in the atmosphere. c) Electromagnetic energy in the form of electromagnetic

Gilbes, Fernando

57

Electromagnetically Induced Flows Michiel de Reus  

E-print Network

Electromagnetically Induced Flows in Water Michiel de Reus 8 maart 2013 () Electromagnetically Conclusion and future research () Electromagnetically Induced Flows 2 / 56 #12;1 Introduction 2 Maxwell Navier Stokes equations 5 Simulations 6 Conclusion and future research () Electromagnetically Induced

Vuik, Kees

58

Electromagnetic radiations from rocks  

Microsoft Academic Search

To test the possibility of the emission of electromagnetic waves from rocks, experiments have been made to measure the electric field by using mainly granite samples that were struck together or struck by a hammer or a weight and were fractured by a bending moment. The wide-band (10 Hz to 100 kHz) waveforms of electric signals were digitally recorded. Roughly

Toshio Ogawa; Kazuo Oike; Taiji Miura

1985-01-01

59

Simple Superconducting "Permanent" Electromagnet  

NASA Technical Reports Server (NTRS)

Proposed short tube of high-temperature-superconducting material like YBa2Cu3O7 acts as strong electromagnet that flows as long as magnetic field remains below critical value and temperature of cylinder maintained sufficiently below superconducting-transition temperature. Design exploits maximally anisotropy of high-temperature-superconducting material.

Israelson, Ulf E.; Strayer, Donald M.

1992-01-01

60

Electromagnetic ultrasonic transducers  

Microsoft Academic Search

Direct electromagnetic generation is a relatively recent addition to the list of techniques available for the generation of ultrasonic waves for nondestructive evaluation purposes. The history and physics of the generation technique will be discussed. In addition, transducer designs for the generation of various types of sound waves (longitudinal, shear and surface) will be presented. In particular, surface wave transducer

T. J. Moran

1979-01-01

61

Electromagnetism and Gravitation  

E-print Network

The classical concept of "mass density" is not fundamental to the quantum theory of matter. Therefore, mass density cannot be the source of gravitation. Here, we treat electromagnetic energy, momentum, and stress as its source. The resulting theory predicts that the gravitational potential near any charged elementary particle is many orders of magnitude greater than the Newtonian value.

Kenneth Dalton

1995-12-12

62

Electromagnetic pulsar spindown  

E-print Network

We evaluate the result of the recent pioneering numerical simulations in Spitkovsky~2006 on the spindown of an oblique relativistic magnetic dipole rotator. Our discussion is based on our experience from two idealized cases, that of an aligned dipole rotator, and that of an oblique split-monopole rotator. We conclude that the issue of electromagnetic pulsar spindown may not have been resolved yet.

I. Contopoulos

2007-01-10

63

Electromagnetic brain mapping  

Microsoft Academic Search

There has been tremendous advances in our ability to produce images of human brain function. Applications of functional brain imaging extend from improving our understanding of the basic mechanisms of cognitive processes to better characterization of pathologies that impair normal function. Magnetoencephalography (MEG) and electroencephalography (EEG) (MEG\\/EEG) localize neural electrical activity using noninvasive measurements of external electromagnetic signals. Among the

S. Baillet; J. C. Mosher; R. M. Leahy

2001-01-01

64

Equivalence principles and electromagnetism  

NASA Technical Reports Server (NTRS)

The implications of the weak equivalence principles are investigated in detail for electromagnetic systems in a general framework. In particular, it is shown that the universality of free-fall trajectories (Galileo weak equivalence principle) does not imply the validity of the Einstein equivalence principle. However, the Galileo principle plus the universality of free-fall rotation states does imply the Einstein principle.

Ni, W.-T.

1977-01-01

65

Nucleon electromagnetic form factors  

SciTech Connect

A review of data on the nucleon electromagnetic form factors in the space-like region is presented. Recent results from experiments using polarized beams and polarized targets or nucleon recoil polarimeters have yielded a significant improvement on the precision of the data obtained with the traditional Rosenbluth separation. Future plans for extended measurements are outlined.

Kees de Jager

2000-01-01

66

Noncontact Electromagnetic Vibration Source  

NASA Technical Reports Server (NTRS)

Metal aircraft skins scanned rapidly in vibration tests. Relatively simple combination of permanent magnets and electromagnet serves as noncontact vibration source for nondestructive testing of metal aircraft skins. In test, source excites vibrations, and vibration waveforms measured, then analyzed for changes in resonances signifying cracks and other flaws.

Namkung, Min; Fulton, James P.; Wincheski, Buzz A.

1994-01-01

67

Spectroscopy Interaction of electromagnetic radiation  

E-print Network

Spectroscopy 691 Interaction of electromagnetic radiation with atoms or molecules #12;Bacteriorhodopsin: a light-driven proton pump 486 #12;Electromagnetic Radiation 692 harmonic wave (Maxwell): y;Spectroscopy 691 Interaction of electromagnetic radiation with atoms or molecules two processes: emission

Gerwert, Klaus

68

Electromagnetic environment of RFID systems  

Microsoft Academic Search

In this paper, the influence of the electromagnetic environment on RFID (radio frequency identification) systems is studied. By electromagnetic environment, we consider the electromagnetic waves interference on a RFID system performance produced by applications located nearby. In particular, we analyze the effects of using a GSM mobile phone near an UHF-868 MHz RFID system. For the tested configurations, the results

Delia Arnaud-Cormos; Thierry Letertre; Antoine Diet; Alain Azoulay

2007-01-01

69

Computational Electronics and Electromagnetics  

SciTech Connect

The Computational Electronics and Electromagnetics thrust area is a focal point for computer modeling activities in electronics and electromagnetics in the Electronics Engineering Department of Lawrence Livermore National Laboratory (LLNL). Traditionally, they have focused their efforts in technical areas of importance to existing and developing LLNL programs, and this continues to form the basis for much of their research. A relatively new and increasingly important emphasis for the thrust area is the formation of partnerships with industry and the application of their simulation technology and expertise to the solution of problems faced by industry. The activities of the thrust area fall into three broad categories: (1) the development of theoretical and computational models of electronic and electromagnetic phenomena, (2) the development of useful and robust software tools based on these models, and (3) the application of these tools to programmatic and industrial problems. In FY-92, they worked on projects in all of the areas outlined above. The object of their work on numerical electromagnetic algorithms continues to be the improvement of time-domain algorithms for electromagnetic simulation on unstructured conforming grids. The thrust area is also investigating various technologies for conforming-grid mesh generation to simplify the application of their advanced field solvers to design problems involving complicated geometries. They are developing a major code suite based on the three-dimensional (3-D), conforming-grid, time-domain code DSI3D. They continue to maintain and distribute the 3-D, finite-difference time-domain (FDTD) code TSAR, which is installed at several dozen university, government, and industry sites.

DeFord, J.F.

1993-03-01

70

Electromagnetic Environment of Grounding Systems  

NASA Astrophysics Data System (ADS)

Electromagnetic compatibility (EMC) and lightning protection studies in large installations require knowledge of spatial and temporal distribution of electromagnetic fields in case of lightning and power system faults. A new hybrid method for modeling electromagnetic environment of grounding systems is developed in this work. The electromagnetic fields in the surrounding soil are determined from the previously calculated current distribution using dipoles theory with analytical formulas. The model can be used to predict the EM environment of grounding systems because it can calculate electromagnetic fields in any points of interest.

Lefouili, M.; Hafsaoui, I.; Kerroum, K.; Drissi, K. El Khamlichi

71

Magnetism and Electromagnetism  

NSDL National Science Digital Library

All About Circuits is a website that âprovides a series of online textbooks covering electricity and electronics.â Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Magnetism and Electromagnetism, is the fourteenth chapter in Volume I â Direct Current. A few of the topics covered in this chapter include: Permanent magnets; Electromagnetic induction; and Mutual inductance. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

2008-07-07

72

Environmental and space electromagnetics  

NASA Astrophysics Data System (ADS)

The present volume on environmental and space electromagnetics discusses spacecraft EM environment, natural and triggered lightning, atmospherics, whistlers, and emissions, and natural VLF/ELF radio noise. Attention is given to terrestrial and extraterrestrial noise environment, planetary lightning and cosmic plasma noise, noise and communication statistics, and space communication and measurement. Topics addressed include high-power electromagnetics, seismoelectric emissions, ball lightning, and meteorologico-electric phenomena and EHD. Also discussed are the characteristics of winter lightning strokes observed with video camera systems, polar VLF emissions observed by ISIS satellites, ray focusing of whistler-mode waves in a magnetoplasma, radio sky mapping from satellites at VLFs, and MW observations of the sun during the 22nd solar activity cycle.

Kikuchi, Hiroshi

73

Faraday's Electromagnetic Lab  

NSDL National Science Digital Library

Play with a bar magnet and coils to learn about Faraday's law. Move a bar magnet near one or two coils to make a light bulb glow. View the magnetic field lines. A meter shows the direction and magnitude of the current. View the magnetic field lines or use a meter to show the direction and magnitude of the current. You can also play with electromagnets, generators and transformers!

Simulations, Phet I.; Dubson, Michael; Malley, Chris; Perkins, Kathy; Wieman, Carl; Harlow, Danielle

2005-04-01

74

The KLOE electromagnetic calorimeter  

Microsoft Academic Search

The KLOE calorimeter is a fine lead-scintillating fiber sampling calorimeter. We describe in the following the calibration procedures and the calorimeter performances obtained after 3 years of data taking. We get an energy resolution for electromagnetic showers of 5.4%\\/E(GeV) and a time resolution of 56 ps\\/E(GeV). We also present a measurement of efficiency for low-energy photons.

M. Adinolfi; F. Ambrosino; A. Antonelli; M. Antonelli; F. Anulli; G. Barbiellini; G. Bencivenni; S. Bertolucci; C. Bini; C. Bloise; V. Bocci; F. Bossi; P. Branchini; G. Cabibbo; R. Caloi; P. Campana; M. Casarsa; G. Cataldi; F. Ceradini; F. Cervelli; P. Ciambrone; E. De Lucia; P. De Simone; G. De Zorzi; S. Dell'Agnello; A. Denig; A. di Domenico; C. di Donato; S. Di Falco; A. Doria; O. Erriquez; A. Farilla; A. Ferrari; M. L. Ferrer; G. Finocchiaro; C. Forti; A. Franceschi; P. Franzini; M. L. Gao; C. Gatti; P. Gauzzi; A. Giannasi; S. Giovannella; E. Graziani; H. G. Han; S. W. Han; X. Huang; M. Incagli; L. Ingrosso; L. Keeble; W. Kim; C. Kuo; G. Lanfranchi; J. Lee-Franzini; T. Lomtadze; C. S. Mao; M. Martemianov; W. Mei; R. Messi; S. Miscetti; S. Moccia; M. Moulson; S. Mller; F. Murtas; L. Pacciani; M. Palomba; M. Palutan; E. Pasqualucci; L. Passalacqua; A. Passeri; D. Picca; G. Pirozzi; L. Pontecorvo; M. Primavera; P. Santangelo; E. Santovetti; G. Saracino; R. D. Schamberger; B. Sciascia; F. Scuri; I. Sfiligoi; P. Silano; T. Spadaro; E. Spiriti; L. Tortora; P. Valente; B. Valeriani; G. Venanzoni; A. Ventura; S. Wlfle; Y. Wu; Y. G. Xie; P. F. Zema; C. D. Zhang; J. Q. Zhang; P. P. Zhao

2002-01-01

75

Electromagnetic detection of axions  

E-print Network

Photon-to-axion conversions in the static electromagnetic fields are reconsidered in detail by using the Feynman diagram techniques. The differential cross sections are presented for the conversions in the presence of the electric field of the flat condenser as well as in the magnetic field of the solenoid. Based on our results a laboratory experiment for the production and the detection of the axions is described. This experiment will exploit the axion decay constant as well as the axion mass.

Hoang Ngoc Long; Dang Van Soa; Tuan A. Tran

1995-07-24

76

Banded electromagnetic stator core  

DOEpatents

A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

Fanning, Alan W. (San Jose, CA); Gonzales, Aaron A. (San Jose, CA); Patel, Mahadeo R. (San Jose, CA); Olich, Eugene E. (Aptos, CA)

1994-01-01

77

Banded electromagnetic stator core  

DOEpatents

A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups.

Fanning, Alan W. (San Jose, CA); Gonzales, Aaron A. (San Jose, CA); Patel, Mahadeo R. (San Jose, CA); Olich, Eugene E. (Aptos, CA)

1996-01-01

78

Banded electromagnetic stator core  

DOEpatents

A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figures.

Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

1994-04-05

79

Banded electromagnetic stator core  

DOEpatents

A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figs.

Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

1996-06-11

80

Quaternion Gravi-Electromagnetism  

E-print Network

Defining the generalized charge, potential, current and generalized fields as complex quantities where real and imaginary parts represent gravitation and electromagnetism respectively, corresponding field equation, equation of motion and other quantum equations are derived in manifestly covariant manner. It has been shown that the field equations are invariant under Lorentz as well as duality transformations. It has been shown that the quaternionic formulation presented here remains invariant under quaternion transformations.

A. S. Rawat; O. P. S. Negi

2011-07-05

81

Gravitation and Electromagnetism  

E-print Network

The realms of gravitation, belonging to Classical Physics, and Electromagnetism, belonging to the Theory of the Electron and Quantum Mechanics have remained apart as two separate pillars, inspite of a century of effort by Physicists to reconcile them. In this paper it is argued that if we extend ideas of Classical spacetime to include in addition to non integrability non commutavity also, then such a reconcilation is possible.

B. G. Sidharth

2001-06-16

82

Fractional Electromagnetic Waves  

E-print Network

In the present work we consider the electromagnetic wave equation in terms of the fractional derivative of the Caputo type. The order of the derivative being considered is 0 <\\gamma<1. A new parameter \\sigma, is introduced which characterizes the existence of the fractional components in the system. We analyze the fractional derivative with respect to time and space, for \\gamma = 1 and \\gamma = 1/2 cases.

J. F. Gmez; J. J. Rosales; J. J. Bernal; V. I. Tkach; M. Gua

2011-08-31

83

Electromagnetic tornadoes in space  

SciTech Connect

The exotic phenomenon of energetic-ion conic formation by plasma waves in the magnetosphere is considered. Two particular transverse heating mechanisms are reviewed in detail; lower-hybrid energization of ions in the boundary layer of the plasma sheet and electromagnetic ion cyclotron resonance heating in the central region of the plasma sheet. Mean particle calculations, plasma simulations and analytical treatments of the heating processes are described.

Chang, T.; Crew, G.B.; Retterer, J.M.

1988-01-01

84

Gravito-electromagnetic analogies  

NASA Astrophysics Data System (ADS)

We reexamine and further develop different gravito-electromagnetic (GEM) analogies found in the literature, and clarify the connection between them. Special emphasis is placed in two exact physical analogies: the analogy based on inertial fields from the so-called "1+3 formalism", and the analogy based on tidal tensors. Both are reformulated, extended and generalized. We write in both formalisms the Maxwell and the full exact Einstein field equations with sources, plus the algebraic Bianchi identities, which are cast as the source-free equations for the gravitational field. New results within each approach are unveiled. The well known analogy between linearized gravity and electromagnetism in Lorentz frames is obtained as a limiting case of the exact ones. The formal analogies between the Maxwell and Weyl tensors are also discussed, and, together with insight from the other approaches, used to physically interpret gravitational radiation. The precise conditions under which a similarity between gravity and electromagnetism occurs are discussed, and we conclude by summarizing the main outcome of each approach.

Costa, L. Filipe O.; Natrio, Jos

2014-10-01

85

Coherent hybrid electromagnetic field imaging  

DOEpatents

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.

Cooke, Bradly J. (Jemez Springs, NM); Guenther, David C. (Los Alamos, NM)

2008-08-26

86

Electromagnetic WavesElectromagnetic Waves In this chapter we will review selected properties of electromagnetic waves since  

E-print Network

Electromagnetic WavesElectromagnetic Waves In this chapter we will review selected properties of electromagnetic waves since radar involves the transmission, propagation and scattering of EM waves by various is the electrostatic force between two point charges. #12;Electromagnetic WavesElectromagnetic Waves Electric fields

Rutledge, Steven

87

Electromagnetic field and cosmic censorship  

E-print Network

We construct a gedanken experiment in which an extremal Kerr black hole interacts with a test electromagnetic field. Using Teukolsky's solutions for electromagnetic perturbations in Kerr spacetime, and the conservation laws imposed by the energy momentum tensor of the electromagnetic field and the Killing vectors of the spacetime, we prove that this interaction cannot convert the black hole into a naked singularity, thus cosmic censorship conjecture is not violated in this case.

Koray Dzta?

2013-12-27

88

Statistical Properties of Electromagnetic Environment in Wireless Networks, Intra-Network Electromagnetic Compatibility and Safety  

E-print Network

Statistical Properties of Electromagnetic Environment in Wireless Networks, Intra of electromagnetic environment in wireless networks affecting its intra- network electromagnetic compatibility-Network Electromagnetic Compatibility and Safety Vladimir Mordachev Belorussian State University of Informatics

Loyka, Sergey

89

Electromagnetism on Anisotropic Fractals  

E-print Network

We derive basic equations of electromagnetic fields in fractal media which are specified by three indepedent fractal dimensions {\\alpha}_{i} in the respective directions x_{i} (i=1,2,3) of the Cartesian space in which the fractal is embedded. To grasp the generally anisotropic structure of a fractal, we employ the product measure, so that the global forms of governing equations may be cast in forms involving conventional (integer-order) integrals, while the local forms are expressed through partial differential equations with derivatives of integer order but containing coefficients involving the {\\alpha}_{i}'s. First, a formulation based on product measures is shown to satisfy the four basic identities of vector calculus. This allows a generalization of the Green-Gauss and Stokes theorems as well as the charge conservation equation on anisotropic fractals. Then, pursuing the conceptual approach, we derive the Faraday and Amp\\`ere laws for such fractal media, which, along with two auxiliary null-divergence conditions, effectively give the modified Maxwell equations. Proceeding on a separate track, we employ a variational principle for electromagnetic fields, appropriately adapted to fractal media, to independently derive the same forms of these two laws. It is next found that the parabolic (for a conducting medium) and the hyperbolic (for a dielectric medium) equations involve modified gradient operators, while the Poynting vector has the same form as in the non-fractal case. Finally, Maxwell's electromagnetic stress tensor is reformulated for fractal systems. In all the cases, the derived equations for fractal media depend explicitly on fractal dimensions and reduce to conventional forms for continuous media with Euclidean geometries upon setting the dimensions to integers.

Martin Ostoja-Starzewski

2011-06-08

90

Electromagnetic pump stator coil  

DOEpatents

An electrical stator coil for an electromagnetic pump includes a continuous conductor strip having first and second terminals at opposite ends thereof and an intermediate section disposed therebetween. The strip is configured in first and second coil halves, with the first coil half including a plurality of windings extending from the first terminal to the intermediate section, and the second coil half including a plurality of windings extending from the second terminal to the intermediate section. The first and second coil halves are disposed coaxially, and the first and second terminals are disposed radially inwardly therefrom with the intermediate section being disposed radially outwardly therefrom.

Fanning, Alan W. (San Jose, CA); Dahl, Leslie R. (Livermore, CA)

1996-01-01

91

Electromagnetic pump stator coil  

DOEpatents

An electrical stator coil for an electromagnetic pump includes a continuous conductor strip having first and second terminals at opposite ends thereof and an intermediate section disposed therebetween. The strip is configured in first and second coil halves, with the first coil half including a plurality of windings extending from the first terminal to the intermediate section, and the second coil half including a plurality of windings extending from the second terminal to the intermediate section. The first and second coil halves are disposed coaxially, and the first and second terminals are disposed radially inwardly therefrom with the intermediate section being disposed radially outwardly therefrom. 9 figs.

Fanning, A.W.; Dahl, L.R.

1996-06-25

92

Gravitation and electromagnetism  

E-print Network

Maxwell's equations comprise both electromagnetic and gravitational fields. The transverse part of the vector potential belongs to magnetism, the longitudinal one is concerned with gravitation. The Coulomb gauge indicates that longitudinal components of the fields propagate instantaneously. The delta-function singularity of the field of the divergence of the vector potential, referred to as the dilatation center, represents an elementary agent of gravitation. Viewing a particle as a source or a scattering center of the point dilatation, the Newton's gravitation law can be reproduced.

V. P. Dmitriyev

2002-07-23

93

Electromagnetic Probes in PHENIX  

E-print Network

Electromagnetic probes are arguably the most universal tools to study the different physics processes in high energy hadron and heavy ion collisions. In this paper we summarize recent measurements of real and virtual direct photons at central rapidity by the PHENIX experiment at RHIC in p+p, d+Au and Au+Au collisions. We also discuss the impact of the results and the constraints they put on theoretical models. At the end we report on the immediate as well as on the mid-term future of photon measurements at RHIC.

Gabor David

2006-09-21

94

Electromagnetic Meissner effect launcher  

NASA Technical Reports Server (NTRS)

An electromagnetic projectile launcher provides acceleration of a superconducting projectile through the diamagnetic repulsion of the superconducting projectile. A superconducting layer is provided aft of the projectile, either directly on the projectile or on a platform upon which the projectile is carried, and a traveling magnetic field is caused to propagate along a magnetic field drive coil in which the projectile is disposed. The resulting diamagnetic repulsion between the superconducting projectile and the traveling magnetic field causes the projectile to be propelled along the coil. In one embodiment, a segmented drive coil is used to generate the traveling magnetic field.

Robertson, Glen A. (inventor)

1991-01-01

95

Metamaterials beyond electromagnetism.  

PubMed

Metamaterials are rationally designed man-made structures composed of functional building blocks that are densely packed into an effective (crystalline) material. While metamaterials are mostly associated with negative refractive indices and invisibility cloaking in electromagnetism or optics, the deceptively simple metamaterial concept also applies to rather different areas such as thermodynamics, classical mechanics (including elastostatics, acoustics, fluid dynamics and elastodynamics), and, in principle, also to quantum mechanics. We review the basic concepts, analogies and differences to electromagnetism, and give an overview on the current state of the art regarding theory and experiment-all from the viewpoint of an experimentalist. This review includes homogeneous metamaterials as well as intentionally inhomogeneous metamaterial architectures designed by coordinate-transformation-based approaches analogous to transformation optics. Examples are laminates, transient thermal cloaks, thermal concentrators and inverters, 'space-coiling' metamaterials, anisotropic acoustic metamaterials, acoustic free-space and carpet cloaks, cloaks for gravitational surface waves, auxetic mechanical metamaterials, pentamode metamaterials ('meta-liquids'), mechanical metamaterials with negative dynamic mass density, negative dynamic bulk modulus, or negative phase velocity, seismic metamaterials, cloaks for flexural waves in thin plates and three-dimensional elastostatic cloaks. PMID:24190877

Kadic, Muamer; Bckmann, Tiemo; Schittny, Robert; Wegener, Martin

2013-12-01

96

Metamaterials beyond electromagnetism  

NASA Astrophysics Data System (ADS)

Metamaterials are rationally designed man-made structures composed of functional building blocks that are densely packed into an effective (crystalline) material. While metamaterials are mostly associated with negative refractive indices and invisibility cloaking in electromagnetism or optics, the deceptively simple metamaterial concept also applies to rather different areas such as thermodynamics, classical mechanics (including elastostatics, acoustics, fluid dynamics and elastodynamics), and, in principle, also to quantum mechanics. We review the basic concepts, analogies and differences to electromagnetism, and give an overview on the current state of the art regarding theory and experimentall from the viewpoint of an experimentalist. This review includes homogeneous metamaterials as well as intentionally inhomogeneous metamaterial architectures designed by coordinate-transformation-based approaches analogous to transformation optics. Examples are laminates, transient thermal cloaks, thermal concentrators and inverters, space-coiling metamaterials, anisotropic acoustic metamaterials, acoustic free-space and carpet cloaks, cloaks for gravitational surface waves, auxetic mechanical metamaterials, pentamode metamaterials (meta-liquids), mechanical metamaterials with negative dynamic mass density, negative dynamic bulk modulus, or negative phase velocity, seismic metamaterials, cloaks for flexural waves in thin plates and three-dimensional elastostatic cloaks.

Kadic, Muamer; Bckmann, Tiemo; Schittny, Robert; Wegener, Martin

2013-12-01

97

Electromagnetic Field Penetration Studies  

NASA Technical Reports Server (NTRS)

A numerical method is presented to determine electromagnetic shielding effectiveness of rectangular enclosure with apertures on its wall used for input and output connections, control panels, visual-access windows, ventilation panels, etc. Expressing EM fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential electric and magnetic fields across the apertures. Using the Method of Moments, the integral equations are solved for unknown aperture fields. From these aperture fields, the EM field inside a rectangular enclosure due to external electromagnetic sources are determined. Numerical results on electric field shielding of a rectangular cavity with a thin rectangular slot obtained using the present method are compared with the results obtained using simple transmission line technique for code validation. The present technique is applied to determine field penetration inside a Boeing-757 by approximating its passenger cabin as a rectangular cavity filled with a homogeneous medium and its passenger windows by rectangular apertures. Preliminary results for, two windows, one on each side of fuselage were considered. Numerical results for Boeing-757 at frequencies 26 MHz, 171-175 MHz, and 428-432 MHz are presented.

Deshpande, M.D.

2000-01-01

98

Televisions, Video Privacy, and Powerline Electromagnetic Interference  

E-print Network

Televisions, Video Privacy, and Powerline Electromagnetic Interference Miro Enev University that the power supplies of modern TVs produce discernible electromagnetic interference (EMI) signatures security, electromagnetic in- terference 1. INTRODUCTION It is known that consumer electronic devices can

Matsuoka, Yoky

99

Electromagnetic Characterization of MIMO Communication Systems  

E-print Network

electromagnetic interactions between the antenna arrays and the environment. To dissect the influence of various and the complex electromagnetic interactions between the antennas and the environment. SingleElectromagnetic Characterization of MIMO Communication Systems Kapil R. Dandekar, Sumant Kawale

Dong, Liang

100

TWO UNCONVENTIONAL APPROACHES TO ELECTROMAGNETIC INVERSION  

E-print Network

TWO UNCONVENTIONAL APPROACHES TO ELECTROMAGNETIC INVERSION Hierarchical Bayesian Inversion and Head, Department of Geophysics ii #12;ABSTRACT Electromagnetic methods are effective complementary approaches of electromagnetic inversion: hier- archical Bayesian inversion and inverse scattering series. We

Snieder, Roel

101

Exploration of the Electromagnetic Environment  

ERIC Educational Resources Information Center

The electromagnetic environment is composed of electric and magnetic fields which result from man-made and natural sources. An elementary experiment is described to explore the electromagnetic environment by measuring electric fields in the frequency range from approximately equal to 10 to 24 000 Hz. The equipment required to conduct the

Fullekrug, M.

2009-01-01

102

Engineering Sciences 151 Electromagnetic Communication  

E-print Network

) pyramidal horn antennas, Narda, Model 640 Large aperture (9 cm x 15 cm) pyramidal horn antennas, homemade-99 ELECTROMAGNETIC RADIATION CHARACTERISTICS Microwave Antenna Measurements OBJECTIVE: To study the radiation patterns and other characteristics of a variety of electromagnetic radiators (antennas). EXPERIMENTAL

Jones, R. Victor

103

On spin 2 electromagnetic interactions  

E-print Network

In this paper we (re)consider the problem of electromagnetic interactions for massless spin 2 particles and show that in $(A)dS$ spaces with non-zero cosmological constant it is indeed possible (at least in linear approximation) to switch on minimal electromagnetic interactions supplemented by third derivative non-minimal ones which are necessary to restore gauge invariance.

Yu. M. Zinoviev

2008-06-25

104

Electromagnetic neutrino: a short review  

E-print Network

A short review on selected issues related to the problem of neutrino electromagnetic properties is given. After a flash look at the theoretical basis of neutrino electromagnetic form factors, constraints on neutrino magnetic moments and electric millicharge from terrestrial experiments and astrophysical observations are discussed. We also focus on some recent studies of the problem and on perspectives.

Alexander I. Studenikin

2014-11-09

105

Electromagnetic neutrino: a short review  

E-print Network

A short review on selected issues related to the problem of neutrino electromagnetic properties is given. After a flash look at the theoretical basis of neutrino electromagnetic form factors, constraints on neutrino magnetic moments and electric millicharge from terrestrial experiments and astrophysical observations are discussed. We also focus on some recent studies of the problem and on perspectives.

Studenikin, Alexander I

2014-01-01

106

Particle swarm optimization in electromagnetics  

Microsoft Academic Search

The particle swarm optimization (PSO), new to the electromagnetics community, is a robust stochastic evolutionary computation technique based on the movement and intelligence of swarms. This paper introduces a conceptual overview and detailed explanation of the PSO algorithm, as well as how it can be used for electromagnetic optimizations. This paper also presents several results illustrating the swarm behavior in

Jacob Robinson; Yahya Rahmat-Samii

2004-01-01

107

The Electromagnetic Spectrum: Infrared Waves  

NSDL National Science Digital Library

This webpage, part of a NASA site on the electromagnetic spectrum, presents information on infrared light. An explanation of how objects emit infrared is provided, along with a diagram of the electromagnetic spectrum. The site contains a number of photos made with infrared light.

2007-06-24

108

Gravitational scattering of electromagnetic radiation  

NASA Technical Reports Server (NTRS)

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

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

1980-01-01

109

Electromagnetic reactions on light nuclei  

E-print Network

Electromagnetic reactions on light nuclei are fundamental to advance our understanding of nuclear structure and dynamics. The perturbative nature of the electromagnetic probes allows to clearly connect measured cross sections with the calculated structure properties of nuclear targets. We present an overview on recent theoretical ab-initio calculations of electron-scattering and photonuclear reactions involving light nuclei. We encompass both the conventional approach and the novel theoretical framework provided by chiral effective field theories. Because both strong and electromagnetic interactions are involved in the processes under study, comparison with available experimental data provides stringent constraints on both many-body nuclear Hamiltonians and electromagnetic currents. We discuss what we have learned from studies on electromagnetic observables of light nuclei, starting from the deuteron and reaching up to nuclear systems with mass number A=16.

Sonia Bacca; Saori Pastore

2014-07-13

110

Parallel algorithms for electromagnetic moment method formulations.  

E-print Network

??ENGLISH ABSTRACT: This dissertation investigates the moment method solution of electromagnetic radiation and scattering problems using parallel computers. In particular, electromagnetically large problems with arbitrary (more)

Davidson, David Bruce

1991-01-01

111

Electromagnetic propulsion for spacecraft  

NASA Technical Reports Server (NTRS)

Three electromagnetic propulsion technologies, solid propellant pulsed plasma thrusters (PPT), magnetoplasmadynamic (MPD) thrusters, and pulsed inductive thrusters (PIT) have been developed for application to auxiliary and primary spacecraft propulsion. Both the PPT and MPD thrusters have been flown in space, though only PPTs have been used on operational satellites. The performance of operational PPTs is quite poor, providing only about 8 percent efficiency at about 1000 sec specific impulse. Laboratory PPTs yielding 34 percent efficiency at 5170 sec specific impulse have been demonstrated. Laboratory MPD thrusters have been demonstrated with up to 70 percent efficiency and 7000 sec specific impulse. Recent PIT performance measurements using ammonia and hydrazine propellants are extremely encouraging, reaching 50 percent efficiency for specific impulses between 4000 and 8000 sec.

Myers, Roger M.

1993-01-01

112

Computational electronics and electromagnetics  

SciTech Connect

The Computational Electronics and Electromagnetics thrust area at Lawrence Livermore National Laboratory serves as the focal point for engineering R&D activities for developing computer-based design, analysis, and tools for theory. Key representative applications include design of particle accelerator cells and beamline components; engineering analysis and design of high-power components, photonics, and optoelectronics circuit design; EMI susceptibility analysis; and antenna synthesis. The FY-96 technology-base effort focused code development on (1) accelerator design codes; (2) 3-D massively parallel, object-oriented time-domain EM codes; (3) material models; (4) coupling and application of engineering tools for analysis and design of high-power components; (5) 3-D spectral-domain CEM tools; and (6) enhancement of laser drilling codes. Joint efforts with the Power Conversion Technologies thrust area include development of antenna systems for compact, high-performance radar, in addition to novel, compact Marx generators. 18 refs., 25 figs., 1 tab.

Shang, C. C.

1997-02-01

113

Electromagnetically Clean Solar Arrays  

NASA Technical Reports Server (NTRS)

The term 'electromagnetically clean solar array' ('EMCSA') refers to a panel that contains a planar array of solar photovoltaic cells and that, in comparison with a functionally equivalent solar-array panel of a type heretofore used on spacecraft, (1) exhibits less electromagnetic interferences to and from other nearby electrical and electronic equipment and (2) can be manufactured at lower cost. The reduction of electromagnetic interferences is effected through a combination of (1) electrically conductive, electrically grounded shielding and (2) reduction of areas of current loops (in order to reduce magnetic moments). The reduction of cost is effected by designing the array to be fabricated as a more nearly unitary structure, using fewer components and fewer process steps. Although EMCSAs were conceived primarily for use on spacecraft they are also potentially advantageous for terrestrial applications in which there are requirements to limit electromagnetic interference. In a conventional solar panel of the type meant to be supplanted by an EMCSA panel, the wiring is normally located on the back side, separated from the cells, thereby giving rise to current loops having significant areas and, consequently, significant magnetic moments. Current-loop geometries are chosen in an effort to balance opposing magnetic moments to limit far-0field magnetic interactions, but the relatively large distances separating current loops makes full cancellation of magnetic fields problematic. The panel is assembled from bare photovoltaic cells by means of multiple sensitive process steps that contribute significantly to cost, especially if electomagnetic cleanliness is desired. The steps include applying a cover glass and electrical-interconnect-cell (CIC) sub-assemble, connecting the CIC subassemblies into strings of series-connected cells, laying down and adhesively bonding the strings onto a panel structure that has been made in a separate multi-step process, and mounting the wiring on the back of the panel. Each step increases the potential for occurrence of latent defects, loss of process control, and attrition of components. An EMCSA panel includes an integral cover made from a transparent material. The silicone cover supplants the individual cover glasses on the cells and serves as an additional unitary structural support that offers the advantage, relative to glass, of the robust, forgiving nature of the silcone material. The cover contains pockets that hold the solar cells in place during the lamination process. The cover is coated with indium tin oxide to make its surface electrically conductive, so that it serves as a contiguous, electrically grounded shield over the entire panel surface. The cells are mounted in proximity to metallic printed wiring. The painted-wiring layer comprises metal-film traces on a sheet of Kapton (or equivalent) polyimide. The traces include contact pads on one side of the sheet for interconnecting the cells. Return leads are on the opposite side of the sheet, positioned to form the return currents substantially as mirror images of, and in proximity to, the cell sheet currents, thereby minimizing magnetic moments. The printed-wiring arrangement mimics the back-wiring arrangement of conventional solar arrays, but the current-loop areas and the resulting magnetic moments are much smaller because the return-current paths are much closer to the solar-cell sheet currents. The contact pads are prepared with solder fo electrical and mechanical bonding to the cells. The pocketed cover/shield, the solar cells, the printed-wiring layer, an electrical bonding agent, a mechanical-bonding agent, a composite structural front-side face sheet, an aluminum honeycomb core, and a composite back-side face sheet are all assembled, then contact pads are soldered to the cells and the agents are cured in a single lamination process.

Stem, Theodore G.; Kenniston, Anthony E.

2008-01-01

114

Wavelets and electromagnetics  

NASA Technical Reports Server (NTRS)

Wavelets are an exciting new topic in applied mathematics and signal processing. This paper will provide a brief review of wavelets which are also known as families of functions with an emphasis on interpretation rather than rigor. We will derive an indirect use of wavelets for the solution of integral equations based techniques adapted from image processing. Examples for resistive strips will be given illustrating the effect of these techniques as well as their promise in reducing dramatically the requirement in order to solve an integral equation for large bodies. We also will present a direct implementation of wavelets to solve an integral equation. Both methods suggest future research topics and may hold promise for a variety of uses in computational electromagnetics.

Kempel, Leo C.

1992-01-01

115

Electromagnetically revolving sphere viscometer  

NASA Astrophysics Data System (ADS)

In this paper, we propose a new method of low viscosity measurement, in which the rolling of a probe sphere on the flat solid bottom of a sample cell is driven remotely and the revolution speed of the probe in a sample liquid gives the viscosity measurements. The principle of this method is based on the electromagnetically spinning technique that we developed, and the method is effective especially for viscosity measurements at levels below 100 mPas with an accuracy higher than 1%. The probe motion is similar to that in the well-known rolling sphere (ball) method. However, our system enables a steady and continuous measurement of viscosity, which is problematic using the conventional method. We also discuss the limits of the measurable viscosity range common to rolling-sphere-type viscometers by considering the accelerating motion of a probe sphere due to gravity, and we demonstrate the performance of our methods.

Hosoda, Maiko; Sakai, Keiji

2014-12-01

116

Causal electromagnetic interaction equations  

SciTech Connect

For the electromagnetic interaction of two particles the relativistic causal quantum mechanics equations are proposed. These equations are solved for the case when the second particle moves freely. The initial wave functions are supposed to be smooth and rapidly decreasing at the infinity. This condition is important for the convergence of the integrals similar to the integrals of quantum electrodynamics. We also consider the singular initial wave functions in the particular case when the second particle mass is equal to zero. The discrete energy spectrum of the first particle wave function is defined by the initial wave function of the free-moving second particle. Choosing the initial wave functions of the free-moving second particle it is possible to obtain a practically arbitrary discrete energy spectrum.

Zinoviev, Yury M. [Steklov Mathematical Institute, Gubkin Street 8, 119991, Moscow (Russian Federation)

2011-02-15

117

Electromagnetic inverse scattering  

NASA Technical Reports Server (NTRS)

A three-dimensional electromagnetic inverse scattering identity, based on the physical optics approximation, is developed for the monostatic scattered far field cross section of perfect conductors. Uniqueness of this inverse identity is proven. This identity requires complete scattering information for all frequencies and aspect angles. A nonsingular integral equation is developed for the arbitrary case of incomplete frequence and/or aspect angle scattering information. A general closed-form solution to this integral equation is developed, which yields the shape of the scatterer from such incomplete information. A specific practical radar solution is presented. The resolution of this solution is developed, yielding short-pulse target resolution radar system parameter equations. The special cases of two- and one-dimensional inverse scattering and the special case of a priori knowledge of scatterer symmetry are treated in some detail. The merits of this solution over the conventional radar imaging technique are discussed.

Bojarski, N. N.

1972-01-01

118

Electromagnetic scattering theory  

NASA Technical Reports Server (NTRS)

Electromagnetic scattering theory is discussed with emphasis on the general stochastic variational principle (SVP) and its applications. The stochastic version of the Schwinger-type variational principle is presented, and explicit expressions for its integrals are considered. Results are summarized for scalar wave scattering from a classic rough-surface model and for vector wave scattering from a random dielectric-body model. Also considered are the selection of trial functions and the variational improvement of the Kirchhoff short-wave approximation appropriate to large size-parameters. Other applications of vector field theory discussed include a general vision theory and the analysis of hydromagnetism induced by ocean motion across the geomagnetic field. Levitational force-torque in the magnetic suspension of the disturbance compensation system (DISCOS), now deployed in NOVA satellites, is also analyzed using the developed theory.

Bird, J. F.; Farrell, R. A.

1986-01-01

119

Pulsed electromagnetic gas acceleration  

NASA Technical Reports Server (NTRS)

Experimental data were combined with one-dimensional conservation relations to yield information on the energy deposition ratio in a parallel-plate accelerator, where the downstream flow was confined to a constant area channel. Approximately 70% of the total input power was detected in the exhaust flow, of which only about 20% appeared as directed kinetic energy, thus implying that a downstream expansion to convert chamber enthalpy into kinetic energy must be an important aspect of conventional high power MPD arcs. Spectroscopic experiments on a quasi-steady MPD argon accelerator verified the presence of A(III) and the absence of A(I), and indicated an azimuthal structure in the jet related to the mass injection locations. Measurements of pressure in the arc chamber and impact pressure in the exhaust jet using a piezocrystal backed by a Plexiglas rod were in good agreement with the electromagnetic thrust model.

Jahn, R. G.; Vonjaskowsky, W. F.; Clark, K. E.

1971-01-01

120

Nucleon Electromagnetic Form Factors  

SciTech Connect

There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has greatly improved by performing double polarization experiments, in comparison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at JLab, MAMI, and MIT-Bates. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed, including the recent progress in the determination of the valence quark generalized parton distributions of the nucleon, as well as the steady rate of improvements made in the lattice QCD calculations.

Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi

2007-10-01

121

Adjoint charge in electromagnetic field  

E-print Network

Making use of the octonion operator, the electromagnetic field generates an adjoint field theoretically. The source of adjoint field includes the adjoint charge and the adjoint current. The adjoint charge has an impact on the gravitational mass and the mass distribution in the electromagnetic field with its adjoint field, and causes further the predictions to departure slightly from the conservation of mass. The inferences can explain why the adjoint charge will influence the mass distribution in the gravitational field and electromagnetic field of celestial bodies. And then the adjoint charge can be considered as one kind of candidate for the dark matter.

Zi-Hua Weng

2009-10-07

122

PHYSICS 417. Electromagnetism. Lecturer: Tim Gorringe.  

E-print Network

PHYSICS 417. Electromagnetism. Lecturer: Tim Gorringe. Office: CP273. Phone: 257-8740. Textbook: Electromagnetic Fields, R. Wangsness, 2nd Ed. Web page www.pa.uky.edu/gorringe/phy417/index.html Class hours: MWF-semester sequence on electromagnetic theory. 1 Course Objectives. The electromagnetic field binds electrons

MacAdam, Keith

123

PHYSICS 416. Electromagnetism. Lecturer: Tim Gorringe.  

E-print Network

PHYSICS 416. Electromagnetism. Lecturer: Tim Gorringe. Office: CP 273. Phone: 257-8740. Textbook: Electromagnetic Fields, R. Wangsness, 2nd Ed. Web page www.pa.uky.edu/gorringe/phy416/index.html Class hours: MWF-semester sequence on electromagnetic theory. 1 416/417 Course Objectives. The electromagnetic field binds electrons

MacAdam, Keith

124

Electromagnetic Dissociation and Space Radiation  

E-print Network

Relativistic nucleus-nucleus reactions occur mainly through the Strong or Electromagnetic (EM) interactions. Transport codes often neglect the latter. This work shows the importance of including EM interactions for space radiation applications.

John W. Norbury; Khin Maung Maung

2006-12-08

125

Conical electromagnetic radiation flux concentrator  

NASA Technical Reports Server (NTRS)

Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

Miller, E. R.

1972-01-01

126

Electromagnetic Signals from Bacterial DNA  

E-print Network

Chemical reactions can be induced at a distance due to the propagation of electromagnetic signals during intermediate chemical stages. Although is is well known at optical frequencies, e.g. photosynthetic reactions, electromagnetic signals hold true for muck lower frequencies. In E. coli bacteria such electromagnetic signals can be generated by electric transitions between energy levels describing electrons moving around DNA loops. The electromagnetic signals between different bacteria within a community is a "wireless" version of intercellular communication found in bacterial communities connected by "nanowires". The wireless broadcasts can in principle be of both the AM and FM variety due to the magnetic flux periodicity in electron energy spectra in bacterial DNA orbital motions.

A. Widom; J. Swain; Y. N. Srivastava; S. Sivasubramanian

2012-02-09

127

Electromagnetic Interference In New Aircraft  

NASA Technical Reports Server (NTRS)

Report reviews plans to develop tests and standards to ensure that digital avionics systems in new civil aircraft immune to electromagnetic interference (EMI). Updated standards reflect more severe environment and vulnerabilities of modern avionics.

Larsen, William E.

1991-01-01

128

Materials for electromagnetic interference shielding  

Microsoft Academic Search

Materials for the electromagnetic interference (EMI) shielding of electronics and radiation sources are reviewed, with emphasis\\u000a on composite materials and resilient EMI gasket materials, which shield mainly by reflection of the radiation at a high frequency.

D. D. L. Chung

2000-01-01

129

Electromagnetic Showers at High Energy  

ERIC Educational Resources Information Center

Some of the properties of electromagnetic showers observed in an experimental study are illustrated. Experimental data and results from quantum electrodynamics are discussed. Data and theory are compared using computer simulation. (BB)

Loos, J. S.; Dawson, S. L.

1978-01-01

130

Seismo-Electromagnetic Study in China  

NASA Astrophysics Data System (ADS)

In this paper, I made a brief review on the earthquake-related electromagnetic study in China, especially focusing on geo-electromagnetic observation and empirical prediction based on the observation data. After introducing briefly the roles of China Earthquake Administration (CEA) in seismo-electromagnetic study in China, I summarized various electromagnetic observations (e.g., apparent resistivity, geoelectric potential, geomagnetic field, electromagnetic disturbance, etc.). As the potential application, I showed the cases of the empirical prediction based on the observed electromagnetic data associated with some earthquakes in China. This paper may provide some useful information for those who want to know the general situation of seismo-electromagnetic study in China.

Huang, Qinghua

131

Electromagnetic Effects in SDF Explosions  

Microsoft Academic Search

The notion of high ion and electron concentrations in the detonation of aluminized explosive mixtures has aroused some interest in electro-magnetic effects that the SDF charges might generate when detonated. Motivated by this interest we have started to investigate whether significant electro-magnetic effects show up in our small-scale experiments. However, the design of instrumentation for this purpose is far from

H Reichenbach; P Neuwald; A L Kuhl

2010-01-01

132

Black Hole Thermodynamics and Electromagnetism  

E-print Network

We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.

Burra G. Sidharth

2005-07-15

133

The Nature of Electromagnetic Radiation  

NSDL National Science Digital Library

This web site is a reference page on electromagnetic radiation. It discusses the spectrum of light and both the wave and quantum nature of radiation. Also included are descriptions of the physics and applications of the different frequency bands, from gamma rays through radio waves, plus links to interactive Java simulations on the topic. See Related Materials on this page for a simpler student tutorial by the same authors on the topic of electromagnetic radiation.

Davidson, Michael; Abramowitz, Mortimer; Fellers, Thomas J.

2008-08-21

134

Electromagnetic suspension and levitation techniques  

Microsoft Academic Search

A comprehensive account is given of state-of-the-art and prospective electromagnetic and electromechanical suspension\\/levitation technologies, using both conventional and superconducting materials, with a view both to their performance improvements over differently grounded technologies and their economic feasibility. In addition to passenger-carrying vehicles, controlled DC electromagnet technologies have been applied to frictionless magnetic bearings, flow meters, conveyor systems, high-speed machine tool spindles,

B. V. Jayawant

1988-01-01

135

Electromagnetically driven peristaltic pump  

DOEpatents

An electromagnetic peristaltic pump apparatus may comprise a main body section having an inlet end and an outlet end and a flexible membrane which divides the main body section into a first cavity and a second cavity. The first cavity is in fluid communication with the inlet and outlet ends of the main body section. The second cavity is not in fluid communication with the first cavity and contains an electrically conductive fluid. The second cavity includes a plurality of electrodes which are positioned within the second cavity generally adjacent the flexible membrane. A magnetic field generator produces a magnetic field having a plurality of flux lines at least some of which are contained within the second cavity of the main body section and which are oriented generally parallel to a flow direction in which a material flows between the inlet and outlet ends of the main body section. A control system selectively places a voltage potential across selected ones of the plurality of electrodes to deflect the flexible membrane in a wave-like manner to move material contained in the first cavity between the inlet and outlet ends of the main body section.

Marshall, Douglas W. (Blackfoot, ID)

2000-01-01

136

Electromagnetic Calorimeter for HADES  

E-print Network

We propose to build the Electromagnetic calorimeter for the HADES di-lepton spectrometer. It will enable to measure the data on neutral meson production from nucleus-nucleus collisions, which are essential for interpretation of dilepton data, but are unknown in the energy range of planned experiments (2-10 GeV per nucleon). The calorimeter will improve the electron-hadron separation, and will be used for detection of photons from strange resonances in elementary and HI reactions. Detailed description of the detector layout, the support structure, the electronic readout and its performance studied via Monte Carlo simulations and series of dedicated test experiments is presented. The device will cover the total area of about 8 m^2 at polar angles between 12 and 45 degrees with almost full azimuthal coverage. The photon and electron energy resolution achieved in test experiments amounts to 5-6%/sqrt(E[GeV]) which is sufficient for the eta meson reconstruction with S/B ratio of 0.4% in Ni+Ni collisions at 8 AGeV. A purity of the identified leptons after the hadron rejection, resulting from simulations based on the test measurements, is better than 80% at momenta above 500 MeV/c, where time-of-flight cannot be used.

W. Czyzycki; E. Epple; L. Fabbietti; M. Golubeva; F. Guber; A. Ivashkin; M. Kajetanowicz; A. Krasa; F. Krizek; A. Kugler; K. Lapidus; E. Lisowski; J. Pietraszko; A. Reshetin; P. Salabura; Y. Sobolev; J. Stanislav; P. Tlusty; T. Torrieri; M. Traxler

2011-09-26

137

Pulsed electromagnetic gas acceleration  

NASA Technical Reports Server (NTRS)

Detailed measurements of the axial velocity profile and electromagnetic structure of a high power, quasi-steady MPD discharge are used to formulate a gasdynamic model of the acceleration process. Conceptually dividing the accelerated plasma into an inner flow and an outer flow, it is found that more than two-thirds of the total power in the plasma is deposited in the inner flow, accelerating it to an exhaust velocity of 12.5 km/sec. The outer flow, which is accelerated to a velocity of only 6.2 km/sec, appears to provide a current conduction path between the inner flow and the anode. Related cathode studies have shown that the critical current for the onset of terminal voltage fluctuations, which was recently shown to be a function of the cathode area, appears to reach an asymptote for cathodes of very large surface area. Detailed floating potential measurements show that the fluctuations are confined to the vicinity of the cathode and hence reflect a cathode emission process rather than a fundamental limit on MPD performance.

Jahn, R. G.; Vonjaskowsky, W. F.; Clark, K. E.

1974-01-01

138

The CPLEAR electromagnetic calorimeter  

NASA Astrophysics Data System (ADS)

A large-acceptance lead/gas sampling electromagnetic calorimeter (ECAL) was constructed for the CPLEAR experiment to detect photons from decays of ? 0s with momentum p?0 ? 800 MeV/ c. The main purpose of the ECAL is to determine the decay vertex of neutral-kaon decays K 0 ? ? 0? 0 ? 4? and K 0 ? ? 0? 0? 0 ? 6?. This requires a position-sensitive photon detector with high spatial granularity in r-, ?-, and z-coordinates. The ECAL - a barrel without end-caps located inside a magnetic field of 0.44 T - consists of 18 identical concentric layers. Each layer of {1}/{3} radiation length ( X0) contains a converter plate followed by small cross-section high-gain tubes of 2640 mm active length which are sandwiched by passive pick-up strip plates. The ECAL, with a total of 6 X0 has an energy resolution of {?(E)}/{E} ? {13%}/{(E( GeV) }and a position resolution of 4.5 mm for the shower foot. The shower topology allows separation of electrons from pions. The design, construction, read-out electronics, and performance of the detector are described.

Adler, R.; Backenstoss, G.; Bal, F.; Behnke, O.; Bloch, P.; Damianoglou, D.; Dechelette, P.; Drge, M.; Eckart, B.; Felder, C.; Fetscher, W.; Fidecaro, M.; Garreta, D.; Gerber, H.-J.; Gumplinger, P.; Guyon, D.; Johner, H. U.; Lofstedt, B.; Kern, J.; Kokkas, P.; Krause, H.; Mall, U.; Marin, C.; Nanni, F.; Pagels, B.; Pavlopoulos, P.; Petit, P.; Polivka, G.; Rheme, Ch.; Ruf, T.; Santoni, C.; Schaller, L. A.; Schopper, A.; Tauscher, L.; Tschopp, H.; Weber, P.; Wendler, H.; Witzig, C.; Wolter, M.; Cplear Collaboration

1997-02-01

139

Megawatt Electromagnetic Plasma Propulsion  

NASA Technical Reports Server (NTRS)

The NASA Glenn Research Center program in megawatt level electric propulsion is centered on electromagnetic acceleration of quasi-neutral plasmas. Specific concepts currently being examined are the Magnetoplasmadynamic (MPD) thruster and the Pulsed Inductive Thruster (PIT). In the case of the MPD thruster, a multifaceted approach of experiments, computational modeling, and systems-level models of self field MPD thrusters is underway. The MPD thruster experimental research consists of a 1-10 MWe, 2 ms pulse-forming-network, a vacuum chamber with two 32 diffusion pumps, and voltage, current, mass flow rate, and thrust stand diagnostics. Current focus is on obtaining repeatable thrust measurements of a Princeton Benchmark type self field thruster operating at 0.5-1 gls of argon. Operation with hydrogen is the ultimate goal to realize the increased efficiency anticipated using the lighter gas. Computational modeling is done using the MACH2 MHD code, which can include real gas effects for propellants of interest to MPD operation. The MACH2 code has been benchmarked against other MPD thruster data, and has been used to create a point design for a 3000 second specific impulse (Isp) MPD thruster. This design is awaiting testing in the experimental facility. For the PIT, a computational investigation using MACH2 has been initiated, with experiments awaiting further funding. Although the calculated results have been found to be sensitive to the initial ionization assumptions, recent results have agreed well with experimental data. Finally, a systems level self-field MPD thruster model has been developed that allows for a mission planner or system designer to input Isp and power level into the model equations and obtain values for efficiency, mass flow rate, and input current and voltage. This model emphasizes algebraic simplicity to allow its incorporation into larger trajectory or system optimization codes. The systems level approach will be extended to the pulsed inductive thruster and other electrodeless thrusters at a future date.

Gilland, James; Lapointe, Michael; Mikellides, Pavlos

2003-01-01

140

Perturbations in electromagnetic dark energy  

SciTech Connect

It has been recently proposed that the presence of a temporal electromagnetic field on cosmological scales could explain the phase of accelerated expansion that the universe is currently undergoing. The field contributes as a cosmological constant and therefore, the homogeneous cosmology produced by such a model is exactly the same as that of ?CDM. However, unlike a cosmological constant term, electromagnetic fields can acquire perturbations which in principle could affect CMB anisotropies and structure formation. In this work, we study the evolution of inhomogeneous scalar perturbations in this model. We show that provided the initial electromagnetic fluctuations generated during inflation are small, the model is perfectly compatible with both CMB and large scale structure observations at the same level of accuracy as ?CDM.

Jimnez, Jose Beltrn; Maroto, Antonio L. [Departamento de Fsica Terica, Universidad Complutense de Madrid, 28040 Madrid (Spain); Koivisto, Tomi S. [Institute for Theoretical Physics, University of Heidelberg, 69120 Heidelberg (Germany); Mota, David F., E-mail: jobeltra@fis.ucm.es, E-mail: T.Koivisto@thphys.uni-heidelberg.de, E-mail: maroto@fis.ucm.es, E-mail: d.f.mota@astro.uio.no [Institute of Theoretical Astrophysics, University of Oslo, 0315 Oslo (Norway)

2009-10-01

141

Perturbations in electromagnetic dark energy  

E-print Network

It has been recently proposed that the presence of a temporal electromagnetic field on cosmological scales could explain the phase of accelerated expansion that the universe is currently undergoing. The field contributes as a cosmological constant and therefore, the homogeneous cosmology produced by such a model is exactly the same as that of $\\Lambda$CDM. However, unlike a cosmological constant term, electromagnetic fields can acquire perturbations which in principle could affect CMB anisotropies and structure formation. In this work, we study the evolution of inhomogeneous scalar perturbations in this model. We show that provided the initial electromagnetic fluctuations generated during inflation are small, the model is perfectly compatible with both CMB and large scale structure observations at the same level of accuracy as $\\Lambda$CDM.

Jose Beltran Jimenez; Tomi S. Koivisto; Antonio L. Maroto; David F. Mota

2009-07-21

142

Dipole-Induced Electromagnetic Transparency  

E-print Network

We determine the optical response of a thin and dense layer of interacting quantum emitters. We show that in such a dense system, the Lorentz redshift and the associated interaction broadening can be used to control the transmission and reflection spectra. In the presence of overlapping resonances, a Dipole-Induced Electromagnetic Transparency (DIET) regime, similar to Electromagnetically Induced Transparency (EIT), may be achieved. DIET relies on destructive interference between the electromagnetic waves emitted by quantum emitters. Carefully tuning material parameters allows to achieve narrow transmission windows in otherwise completely opaque media. We analyze in details this coherent and collective effect using a generalized Lorentz model and show how it can be controlled. Several potential applications of the phenomenon, such as slow light, are proposed.

Raiju Puthumpally-Joseph; Maxim Sukharev; Osman Atabek; Eric Charron

2014-07-08

143

Dipole-induced electromagnetic transparency.  

PubMed

We determine the optical response of a thin and dense layer of interacting quantum emitters. We show that, in such a dense system, the Lorentz redshift and the associated interaction broadening can be used to control the transmission and reflection spectra. In the presence of overlapping resonances, a dipole-induced electromagnetic transparency (DIET) regime, similar to electromagnetically induced transparency (EIT), may be achieved. DIET relies on destructive interference between the electromagnetic waves emitted by quantum emitters. Carefully tuning material parameters allows us to achieve narrow transmission windows in, otherwise, completely opaque media. We analyze in detail this coherent and collective effect using a generalized Lorentz model and show how it can be controlled. Several potential applications of the phenomenon, such as slow light, are proposed. PMID:25361258

Puthumpally-Joseph, Raiju; Sukharev, Maxim; Atabek, Osman; Charron, Eric

2014-10-17

144

Un-renormalized classical electromagnetism  

SciTech Connect

This paper follows in the tradition of direct-action versions of electromagnetism having the aim of avoiding a balance of infinities wherein a mechanical mass offsets an infinite electromagnetic mass so as to arrive at a finite observed value. However, the direct-action approach ultimately failed in that respect because its initial exclusion of self-action was later found to be untenable in the relativistic domain. Pursing the same end, this paper examines instead a version of electromagnetism wherein mechanical action is excluded and self-action is retained. It is shown that the resulting theory is effectively interacting due to the presence of infinite forces. A vehicle for the investigation is a pair of classical point charges in a positronium-like arrangement for which the orbits are found to be self-sustaining and naturally quantized.

Ibison, Michael [Institute for Advanced Studies at Austin, 4030 West Braker Lane, Suite 300, Austin, TX 78759 (United States)]. E-mail: ibison@earthtech.org

2006-02-15

145

Dipole-Induced Electromagnetic Transparency  

NASA Astrophysics Data System (ADS)

We determine the optical response of a thin and dense layer of interacting quantum emitters. We show that, in such a dense system, the Lorentz redshift and the associated interaction broadening can be used to control the transmission and reflection spectra. In the presence of overlapping resonances, a dipole-induced electromagnetic transparency (DIET) regime, similar to electromagnetically induced transparency (EIT), may be achieved. DIET relies on destructive interference between the electromagnetic waves emitted by quantum emitters. Carefully tuning material parameters allows us to achieve narrow transmission windows in, otherwise, completely opaque media. We analyze in detail this coherent and collective effect using a generalized Lorentz model and show how it can be controlled. Several potential applications of the phenomenon, such as slow light, are proposed.

Puthumpally-Joseph, Raiju; Sukharev, Maxim; Atabek, Osman; Charron, Eric

2014-10-01

146

Tensor theory of electromagnetic radiometry  

NASA Astrophysics Data System (ADS)

A theory of electromagnetic radiometry is built on the premise that the electromagnetic generalised radiance has a tensor structure, represented by the electric, magnetic and mixed generalised radiance tensors as fundamental quantities. They allow overcoming the limitations due to the scalar generalised radiances, proposed for characterizing stationary random electromagnetic sources. Furthermore, they provide a unified framework for completely describing the energy flux and the states of spatial coherence and polarization of random electromagnetic fields. So, the fundamental quantities of both the scalar generalised radiometry and the classical radiometry or photometry are deduced as particular cases of the tensor theory. A new procedure of analysis of (second-order) correlations, subject to the accomplishment of conservation laws, is also introduced. It reveals that (1) the primary sources of the measurable radiometric quantities associated to the random electromagnetic fields in any states of spatial coherence and polarization are the individual radiators of the radiant source (the correlations of the electric and magnetic field vectors only modulate the contributions given by those radiators) and (2) there are two physical mechanisms for the transport of measurable radiometric quantities by the electromagnetic field, i.e. the propagation of the contributions from individual radiators and their redistribution over each wavefront on propagation. The term redistribution refers to the transfer of portions of the measurable quantity over the wavefronts on propagation, without change its total value over each wavefront. In this context, a physical meaning is given to the negative values of the generalised radiance, which gives new insight about the Poynting's theory of energy transport.

Castaneda, Roman

2007-08-01

147

Electromagnetic Gun With Commutated Coils  

NASA Technical Reports Server (NTRS)

Proposed electromagnetic gun includes electromagnet coil, turns of which commutated in sequence along barrel. Electrical current fed to two armatures by brushes sliding on bus bars in barrel. Interaction between armature currents and magnetic field from coil produces force accelerating armature, which in turn, pushes on projectile. Commutation scheme chosen so magnetic field approximately coincides and moves with cylindrical region defined by armatures. Scheme has disadvantage of complexity, but in return, enables designer to increase driving magnetic field without increasing armature current. Attainable muzzle velocity increased substantially.

Elliott, David G.

1991-01-01

148

Electromagnetic Models of Extragalactic Jets  

SciTech Connect

Relativistic jets may be confined by large-scale, anisotropic electromagnetic stresses that balance isotropic particle pressure and disordered magnetic field. A class of axisymmetric equilibrium jet models will be described and their radiative properties outlined under simple assumptions. The partition of the jet power between electromagnetic and mechanical forms and the comoving energy density between particles and magnetic field will be discussed. Current carrying jets may be recognized by their polarization patterns. Progress and prospects for measuring this using VLBI and GLAST observations will be summarized.

Lisanti, M.; Blandford, R.; /KIPAC, Menlo Park

2007-10-22

149

Electromagnetic radiation by gravitating bodies  

E-print Network

Gravitating bodies in motion, regardless of their constitution, always produce electromagnetic radiation in the form of photon pairs. This phenomenon is an analog of the radiation caused by the motion of dielectric (or magnetic) bodies. It is a member of a wide class of phenomena named dynamical Casimir effects, and it may be viewed as the squeezing of the electromagnetic vacuum. Production of photon pairs is a purely quantum-mechanical effect. Unfortunately, as we show, the emitted radiation is extremely weak as compared to radiation produced by other mechanisms.

Iwo Bialynicki-Birula; Zofia Bialynicka-Birula

2008-04-06

150

Electromagnetic computations for fusion devices  

SciTech Connect

Among the difficulties in making nuclear fusion a useful energy source, two important ones are producing the magnetic fields needed to drive and confine the plasma, and controlling the eddy currents induced in electrically conducting components by changing fields. All over the world, researchers are developing electromagnetic codes and employing them to compute electromagnetic effects. Ferromagnetic components of a fusion reactor introduce field distortions. Eddy currents are induced in the vacuum vessel, blanket and other torus components of a tokamak when the plasma current disrupts. These eddy currents lead to large forces, and 3-D codes are being developed to study the currents and forces. 35 refs., 6 figs.

Turner, L.R.

1989-09-01

151

Project no. 516369 Electromagnetic compatibility between rolling stock and  

E-print Network

satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment. Electromagnetic interference (EMI): Degradation of the performanceProject no. 516369 Electromagnetic compatibility between rolling stock and rail

Paris-Sud XI, Université de

152

The electromagnetic spectrum : waves of energy  

NSDL National Science Digital Library

In this lesson, students will (1) understand that the sun energy is transferred to Earth by electromagnetic waves, which are transverse waves, (2) understand that there are eight main types of electromagnetic waves, classified on the electromagnetic spectrum according to their wavelengths, and (3) understand how each of the types of electromagnetic radiation is used or found in our everyday lives. This would be a suitable activity for small groups.

Coulson, Tracy; Kennedy, Karen

2002-01-01

153

Electromagnetic effects on geodesic acoustic modes  

SciTech Connect

By using the full electromagnetic drift kinetic equations for electrons and ions, the general dispersion relation for geodesic acoustic modes (GAMs) is derived incorporating the electromagnetic effects. It is shown that m?=?1 harmonic of the GAM mode has a finite electromagnetic component. The electromagnetic corrections appear for finite values of the radial wave numbers and modify the GAM frequency. The effects of plasma pressure ?{sub e}, the safety factor q, and the temperature ratio ? on GAM dispersion are analyzed.

Bashir, M. F., E-mail: frazbashir@yahoo.com [Salam Chair in Physics, G. C. University Lahore, Katchery Road, Lahore 54000 (Pakistan); Department of Physics, G. C. University Lahore, Katchery Road, Lahore 54000 (Pakistan); Smolyakov, A. I. [University of Saskatchewan, 116 Science Place, Saskatoon S7N 5E2 (Canada); Institute of Tokamak Physics, NRC Kurchatov Institute, 123182 Moscow (Russian Federation); Elfimov, A. G. [Institute of Physics, University of So Paulo, So Paulo 05508-090 (Brazil); Melnikov, A. V. [Institute of Tokamak Physics, NRC Kurchatov Institute, 123182 Moscow (Russian Federation); National Research Nuclear University MEPhI, 115409, Moscow (Russian Federation); Murtaza, G. [Visiting Professor, Department of Physics, Quaid-e-Azam University, Islamabad (Pakistan)

2014-08-15

154

STIMULATED ELECTROMAGNETIC EMISSIONS BY HIGH-FREQUENCY ELECTROMAGNETIC PUMPING OF THE  

E-print Network

STIMULATED ELECTROMAGNETIC EMISSIONS BY HIGH-FREQUENCY ELECTROMAGNETIC PUMPING OF THE IONOSPHERIC.S.A. Abstract. A high frequency electromagnetic pump wave transmitted into the ionospheric plasma from the ground can stimulate electromagnetic radiation with frequencies around that of the ionospher- ically

155

Name of the Presentation Fundamental Properties of Electromagnetic RadiationFundamental Properties of Electromagnetic Radiation  

E-print Network

between the Sun and the Earth. Electromagnetic Spectrum Electromagnetic Spectrum The Sun produces Wavelength in meters (m) Electromagnetic Spectrum and the Photon Energy of Visible Light Visible 10 -12 34/9/2004 1 Name of the Presentation Fundamental Properties of Electromagnetic Radiation

156

IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY, VOL. 55, NO. 2, APRIL 2013 395 Electromagnetic Interference Analysis of  

E-print Network

to electromagnetic interference (EMI) is becoming a critical aspect of signal integrity analysis. For mod- eling in high-speed packages [2]. As a result, effi- cient and accurate electromagnetic interference (EMIIEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY, VOL. 55, NO. 2, APRIL 2013 395 Electromagnetic

Roy, Sourajeet

157

EE335 Electromagnetic Theory II Text: Fundamentals of Applied Electromagnetics 5e  

E-print Network

EE335 Electromagnetic Theory II Text: Fundamentals of Applied Electromagnetics 5e Author: Fawwaz T://www.coe.montana.edu/ee/tjkaiser/EE335/ Office Hours: M 9am, W 10am Prerequisites: EE334 Electromagnetic Theory I or permission from: Exam 1 100 Exam 2 100 Exam 3 100 Term paper 100 Homework 100 Final Exam 200 #12;EE 335 Electromagnetic

Kaiser, Todd J.

158

Electromagnetic scattering by indented screens  

Microsoft Academic Search

The problem of three dimensional electromagnetic scattering from a perfectly conducting screen with a bounded indentation is formulated as a system of boundary integral equations for the electric current density on the cavity wall and the interface between the cavity and free space. It is shown how the fictitious current density on the interface may be eliminated resulting in an

John S. Asvestas; R. E. Kleinman

1994-01-01

159

The kaon electromagnetic form factor  

E-print Network

We use recent data on K^+ -> pi^+ e^+ e^-, together with known values for the pion form factor, to derive experimental values for the kaon electromagnetic form factor for 0 < q^2 < 0.125 (GeV/c)^2. The results are then compared with the predictions of the Vector Meson Dominance model, which gives a good fit to the experimental results.

J. Lowe; M. D. Scadron

2005-09-28

160

Electromagnetic Levitation of a Disc  

ERIC Educational Resources Information Center

This paper presents a teaching experiment that explores the levitation of a disc of ferromagnetic material in the presence of the magnetic field produced by a single electromagnet. In comparison to the classical experiment of the levitation of a sphere, the main advantage of the proposed laboratory bench is that the uniform magnetic field

Valle, R.; Neves, F.; de Andrade, R., Jr.; Stephan, R. M.

2012-01-01

161

Using Mathcad in electromagnetics education  

Microsoft Academic Search

Mathcad is an effective learning tool in electromagnetics courses. Use of Mathcad by students in such courses at the University of Denver incorporate four essential ingredients needed for the successful integration of computer aided learning into a curriculum component: (1) involvement by the student in establishing what is to be analyzed by the computer; (2) a general purpose tool rather

Ronald R. DeLyser

1996-01-01

162

Transient electromagnetic interference in substations  

Microsoft Academic Search

Electromagnetic interference levels on sensitive electronic equipment are quantified experimentally and theoretically in air and gas insulated substations of different voltages. Measurement techniques for recording interference voltages and currents and electric and magnetic fields are reviewed and actual interference data are summarized. Conducted and radiated interference coupling mechanisms and levels in substation control wiring are described using both measurement results

C. M. Wiggins; D. E. Thomas; F. S. Nickel; T. M. Salas; S. E. Wright

1994-01-01

163

Electromagnetic interference from wind turbines  

Microsoft Academic Search

Summary form only given. During the late nineteen seventies and eighties the University of Michigan Radiation Laboratory, under sponsorship from the US Department of Energy, studied theoretically and experimentally the effects of wind turbines (WTs) on the performance of various electromagnetic systems. The article summarizes selected portions of the fundamental work carried out and techniques developed under the program which

D. L. Sengupta

1999-01-01

164

Electromagnetic Properties of Binary Composites  

Microsoft Academic Search

This dissertation contains theoretical studies of electromagnetic properties of three different binary granular composites: Dilute conductor-insulator mixtures with conducting fractal clusters in a long-wavelength limit; dense disordered mixtures of dielectrics in a short-wavelength limit; and optically anisotropic \\

Ingrid Helena Hoffmann Zabel; I. H. H

1992-01-01

165

Winged reentrant electromagnetic combustion chamber  

Microsoft Academic Search

An internal combustion engine combustion chamber suitable for electromagnetic stimulation of combustion which has been improved by the addition of combustion chamber periphery extensions (wings) filled with dielectric material. The wing dimensions and filler dielectric material are chosen to allow for specification of the chamber EM resonant frequency, preferably at a frequency in the UHF range (where low cost DC

M. A. V

1985-01-01

166

Electromagnetic methods in applied geophysics  

Microsoft Academic Search

Applied electromagnetic research in recent years has been influenced by the growing importance of geothermal energy, coal, and permafrost, in addition to the traditional area of minerals. The interest in near-insulators such as coal and ice encouraged development of radars and other VHF-UHF techniques. Interpreting such measurements required reliable physical properties data for those materials over a frequency range of

K. Vozoff

1980-01-01

167

Electromagnetic Corrections in Staggered Chiral Perturbation Theory  

E-print Network

Electromagnetic Corrections in Staggered Chiral Perturbation Theory C. Bernard and E.D. Freeland perturbation theory including electromagnetism, and discuss the extent to which quenched-photon simulations can-lat]17Nov2010 #12;Electromagnetic Corrections in Staggered Chiral Perturbation Theory E.D. Freeland 1

Bernard, Claude

168

Acousto-electromagnetic Tomography Habib Ammari  

E-print Network

Acousto-electromagnetic Tomography Habib Ammari Emmanuel Bossy Josselin Garnier§ Laurent Seppecher June 28, 2012 Abstract The aim of this paper is to develop a mathematical framework for acousto-electromagnetic tomography and to introduce an efficient reconstruction algorithm. In electromagnetic wave imaging

Garnier, Josselin

169

Studies on a passive electromagnetic damper  

Microsoft Academic Search

The passive electromagnetic damper has the same configuration as that of the electromagnetic bearing, but no sensors and no closed loop control are needed. Its robustness and no-contact structure are its great advantages. When the rotor vibrates, the electromagnetic field intensity in the air gap is altered, then fluctuating currents in the damper coils and eddy currents inside the surface

ZHENG Shui-ying; PAN Xiao-hong; MA Zhen-fei

170

EMG #121471 Electromagnetics, 25:679693, 2005  

E-print Network

Park, Maryland, USA This paper presents the novel use of resistive sheets to reduce electromagnetic that will be discussed in this paper. Significant reduction of electromagnetic leakage is possible by using loading to function as shields of electromagnetic energy. Metallic enclosures are commonly used to reduce emission

Ramahi, Omar

171

Dynamics and Control of Electromagnetic Satellite Formations  

E-print Network

concept that uses superconducting electromagnetic coils to provide forces and torques between differentDynamics and Control of Electromagnetic Satellite Formations Umair Ahsun, David W. Miller June 2007 SSL # 12-07 #12;2 #12;Dynamics and Control of Electromagnetic Satellite Formations by Umair Ahsun B

172

Galerkin Boundary Element Methods for Electromagnetic Scattering  

E-print Network

on boundary integral equations are widely used in the numeri- cal simulation of electromagnetic scatteringGalerkin Boundary Element Methods for Electromagnetic Scattering A. Buffa1 and R. Hiptmair2 1 acous- tic and electromagnetic scattering. The derivation of various boundary integral equations

Buffa, Annalisa

173

OPTIMIZATION USING TAGUCHI METHOD FOR ELECTROMAGNETIC APPLICATIONS  

E-print Network

OPTIMIZATION USING TAGUCHI METHOD FOR ELECTROMAGNETIC APPLICATIONS Wei-Chung Weng, Fan Yang, Veysel electromagnetic optimization technique based on Taguchi method. Using the concept of the orthogonal array (OA. This study uses a new electromagnetic optimization technique, Taguchi method [1], to design a linear antenna

Elsherbeni, Atef Z.

174

Localization of Classical Waves II: Electromagnetic Waves.  

E-print Network

of electromagnetic waves. This phenomenon arises from coherent multiple scattering and interference, when the scaleLocalization of Classical Waves II: Electromagnetic Waves. Alexander Figotin \\Lambda Department We consider electromagnetic waves in a medium described by a position dependent dielectric constant

175

611: Electromagnetic Theory Problem Sheet 5  

E-print Network

611: Electromagnetic Theory Problem Sheet 5 (1a) Show that the energy-momentum tensor for the electromagnetic field is tracefree, i.e. Tµ µ = 0. What would happen, in a spacetime dimension d = 4? (Assume) Show that the energy-momentum tensor for the electromagnetic field can be written as Tµ = 1 8 (Fµ F

Pope, Christopher

176

611: Electromagnetic Theory Problem Sheet 5  

E-print Network

611: Electromagnetic Theory Problem Sheet 5 (1a) The Null Energy Condition on an energy = (k, 0, 0, k), show that the energy-momentum tensor Tµ = 1 4 Fµ F - 1 4µ F F (1) for electromagnetism if the equality kµ k Tµ = 0 is attained. (2) Show that the energy-momentum tensor for electromagnetism can

Pope, Christopher

177

Physics 4: Introductory Physics Electromagnetism and Light  

E-print Network

Physics 4: Introductory Physics Electromagnetism and Light Professor Jeffrey D. Richman Department: Electromagnetism and Light Welcome to Physics 4! What is your goal in life? If it is to become an engineer or to pursue a career in science, this is a key class for you. Understanding electromagnetism and light

Fygenson, Deborah Kuchnir

178

611: Electromagnetic Theory Problem Sheet 6  

E-print Network

611: Electromagnetic Theory Problem Sheet 6 (1) Consider the expression for the electric field due · dS over a spherical surface that encloses the moving charge. (2a) Consider an electromagnetic wave density and the Poynting vector. (2c) Repeat the steps in (2a) and (2b) for an electromagnetic wave

Pope, Christopher

179

Course Outline Physics 433: Electromagnetism II  

E-print Network

Course Outline Physics 433: Electromagnetism II Spring 2014 Prof. Keun Hyuk "Ken" Ahn 483 Tiernan of this course is on the elementary concepts of electromagnetic fields. Upon completion of the course, students are expected to be capable of using the Maxwell equations to calculate simple electromagnetic problems, ranging

180

Electromagnetics from Simulation to Optimal Design  

E-print Network

1 Electromagnetics from Simulation to Optimal Design Christian Hafner Laboratory for Electromagnetic Fields and Microwave Electronics (IFH) ETH Zurich (Switzerland) Lab: http://www.ifh.ee.ethz.ch COG 23, 2013 #12;2 IFH courses · Advanced engineering electromagnetics (Leuchtmann, start spring 2014

Lang, Annika

181

Electromagnetic Interrogation of Dielectric Materials 1  

E-print Network

Electromagnetic Interrogation of Dielectric Materials 1 H.T. Banks M.W. Buksas Center for Research grant P200A40730. #12; Abstract We investigate time domain based electromagnetic inverse problems electromagnetic phenomenon. For our purposes, we categorize the materials and the models employed to describe them

182

611: Electromagnetic Theory Problem Sheet 5  

E-print Network

611: Electromagnetic Theory Problem Sheet 5 (1) Consider the expression for the electric field due · dS over a spherical surface that encloses the moving charge. (2a) Consider an electromagnetic wave density and the Poynting vector. (2c) Repeat the steps in (2a) and (2b) for an electromagnetic wave

Pope, Christopher

183

Electromagnetic Formation Flight of Satellite Arrays  

E-print Network

Electromagnetic Formation Flight of Satellite Arrays Daniel W. Kwon and David W. Miller February 2005 SSL # 2-05 #12;#12;Electromagnetic Formation Flight of Satellite Arrays By DANIEL W. KWON S;#12;Electromagnetic Formation Flight of Satellite Arrays by DANIEL W. KWON Submitted to the Department of Aeronautics

184

Geant4 low energy electromagnetic physics  

Microsoft Academic Search

The Geant4 simulation toolkit includes a specialised package, implementing a precise treatment of electromagnetic interactions of particles with matter below 1 keV. The Geant4 low energy electromagnetic package provides a variety of models describing the electromagnetic processes of electrons and positrons, photons, charged hadrons and ions, taking into account detailed features, such as atomic shell effects and charge dependence. Those

S. Chauvie; S. Guatelli; V. Ivanchenko; F. Longo; A. Mantero; B. Mascialino; P. Nieminen; L. Pandola; S. Parlati; L. Peralta; M. G. Pia; M. Piergentili; P. Rodrigues; S. Saliceti; A. Trindade

2004-01-01

185

A technology that squeezes electromagnetic waves  

E-print Network

A technology that squeezes electromagnetic waves into minuscule structures may yield a new and manipulate visible light and other electromagnetic waves--could someday replace electronic circuits in micro match those of the electromagnetic field outside the metal. The result is the generation of surface

Atwater, Harry

186

221A Lecture Notes Electromagnetic Couplings  

E-print Network

221A Lecture Notes Electromagnetic Couplings 1 Classical Mechanics The coupling of the electromagnetic field with a charged point particle of charge e is given by a term in the action (MKSA system.1 Electromagnetic field's story One way to introduce the coupling Eq. (1) is by starting with Maxwell's equations

Murayama, Hitoshi

187

COPYRIGHT NOTICE: Robert J. Gould: Electromagnetic Processes  

E-print Network

COPYRIGHT NOTICE: Robert J. Gould: Electromagnetic Processes is published by Princeton University rules) for the calculation of rates of electromagnetic processes. Instead of trying to "derive of electromagnetic radiation begin to be considered seriously.1 In 1922, the par ticle character of the photon

Landweber, Laura

188

Some Student Conceptions of Electromagnetic Induction  

ERIC Educational Resources Information Center

Introductory electromagnetism is a central part of undergraduate physics. Although there has been some research into student conceptions of electromagnetism, studies have been sparse and separated. This study sought to explore second year physics students' conceptions of electromagnetism, to investigate to what extent the results from the present

Thong, Wai Meng; Gunstone, Richard

2008-01-01

189

Computational design for electromagnetic simulations  

NASA Astrophysics Data System (ADS)

An automatic computational procedure has been developed to efficiently and accurately design the shape of complicated electromagnetic objects. These electromagnetic objects can be simulated for operation at high frequencies (10 GHz), and can be comprised of dissimilar materials. The automated design procedure consists of linking together an original electromagnetic field simulation tool, an original adjoint routine for obtaining sensitivity derivatives, and an original grid-smoothing tool with an existing optimization package. The electromagnetic field simulation software employs a temporally and spatially higher-order accurate Streamline Upwind/Petrov-Galerkin finite-element method that numerically solves Maxwell's equations in the time domain using implicit time stepping. The software for computing sensitivity derivatives employs a reverse-mode time-accurate discrete adjoint methodology that is formulated to automatically maintain consistency with the electromagnetic field simulation software. Grid smoothing is achieved using a spatially higher-order accurate Galerkin finite-element method that generates a numerical solution to the linear elastic equations. All computational solutions to the linear systems present in each software tool are obtained using the Generalized Minimum Residual algorithm with block diagonal preconditioning. Each software tool is implemented using a parallel processing paradigm and is therefore capable of being executed on a distributed memory supercomputer. The order of accuracy of the electromagnetic field simulation software has been determined by using comparisons with exact solutions. The field software's results were compared to the exact solution of a rectangular resonant cavity. In all cases, the order properties of the field software exceed theoretical expectations when linear, quadratic, and cubic tetrahedral elements are employed to discretize the field. To demonstrate the consistency of the adjoint-based sensitivity derivates with those obtained directly from the field solver, derivatives have been extracted from the field software using a complex variable technique. The sensitivity derivatives from the reverse-mode time-accurate discrete adjoint method were then compared and demonstrated to agree to at least seven decimal places. As a demonstration of the assembled technologies, the optimization procedure successfully and efficiently modified the shape of two electromagnetic objects to reduce a specified cost function. A dielectric cube, under the influence of a propagating plane wave, was repositioned within a larger free space volume so that the field variables on the surface of the cube match desired values at a specified time. A similar demonstration case has also been conducted to modify the shape of a dielectric ellipsoid, under the same conditions as the cube.

Glasby, Ryan Steven

190

Electromagnetic environmental criteria for US Army missile systems: EMC (electromagnetic compatibility), EMR (electromagnetic radiation), EMI (electromagnetic interference), EMP (electromagnetic pulse), ESD (electrostatic discharge), and lightning. Final report for period ending October 1986  

SciTech Connect

This report presents the design and test requirements in developing an electromagnetic compatibility missile system. Environmental levels are presented for electromagnetic radiation hazards, electromagnetic radiation operational electrostatic discharge, lightning, and electromagnetic pulse (nuclear). Testing techniques and facility capabilities are presented for research and development testing of missile systems.

Kilpatrick, M.; Ponds, C.D.

1987-02-01

191

Strong permanent magnet-assisted electromagnetic undulator  

DOEpatents

This invention discloses an improved undulator comprising a plurality of electromagnet poles located along opposite sides of a particle beam axis with alternate north and south poles on each side of the beam to cause the beam to wiggle or undulate as it travels generally along the beam axis and permanent magnets spaced adjacent the electromagnetic poles on each side of the axis of said particle beam in an orientation sufficient to reduce the saturation of the electromagnet poles whereby the field strength of the electromagnet poles can be increased beyond the normal saturation levels of the electromagnetic poles.

Halbach, Klaus (Berkeley, CA)

1988-01-01

192

Some Wave Equations for Electromagnetism and Gravitation  

E-print Network

The paper studies the inferences of wave equations for electromagnetic fields when there are gravitational fields at the same time. In the description with the algebra of octonions, the inferences of wave equations are identical with that in conventional electromagnetic theory with vector terminology. By means of the octonion exponential function, we can draw out that the electromagnetic waves are transverse waves in a vacuum, and rephrase the law of reflection, Snell's law, Fresnel formula, and total internal reflection etc. The study claims that the theoretical results of wave equations for electromagnetic strength keep unchanged in the case for coexistence of gravitational and electromagnetic fields. Meanwhile the electric and magnetic components of electromagnetic waves can not be determined simultaneously in electromagnetic fields.

Zi-Hua Weng

2010-08-11

193

Electromagnetic response of Weyl semimetals.  

PubMed

It has been suggested recently, based on subtle field-theoretical considerations, that the electromagnetic response of Weyl semimetals and the closely related Weyl insulators can be characterized by an axion term ?EB with space and time dependent axion angle ?(r,t). Here we construct a minimal lattice model of the Weyl medium and study its electromagnetic response by a combination of analytical and numerical techniques. We confirm the existence of the anomalous Hall effect expected on the basis of the field theory treatment. We find, contrary to the latter, that chiral magnetic effect (that is, ground state charge current induced by the applied magnetic field) is absent in both the semimetal and the insulator phase. We elucidate the reasons for this discrepancy. PMID:23889433

Vazifeh, M M; Franz, M

2013-07-12

194

Electromagnetics from a quasistatic perspective  

E-print Network

Quasistatics is introduced so that it fits smoothly into the standard textbook presentation of electrodynamics. The usual path from statics to general electrodynamics is rather short and surprisingly simple. A closer look reveals however that it is not without confusing issues as has been illustrated by many contributions to this Journal. Quasistatic theory is conceptually useful by providing an intermediate level in between statics and the full set of Maxwell's equations. Quasistatics is easier than general electrodynamics and in some ways more similar to statics. It is however, in terms of interesting physics and important applications, far richer than statics. Quasistatics is much used in electromagnetic modeling, an activity that today is possible on a PC and which also has great pedagogical potential. The use of electromagnetic simulations in teaching gives additional support for the importance of quasistatics. This activity may also motivate some change of focus in the presentation of basic electrodynam...

Larsson, J

2006-01-01

195

Electromagnetics from a quasistatic perspective  

E-print Network

Quasistatics is introduced so that it fits smoothly into the standard textbook presentation of electrodynamics. The usual path from statics to general electrodynamics is rather short and surprisingly simple. A closer look reveals however that it is not without confusing issues as has been illustrated by many contributions to this Journal. Quasistatic theory is conceptually useful by providing an intermediate level in between statics and the full set of Maxwell's equations. Quasistatics is easier than general electrodynamics and in some ways more similar to statics. It is however, in terms of interesting physics and important applications, far richer than statics. Quasistatics is much used in electromagnetic modeling, an activity that today is possible on a PC and which also has great pedagogical potential. The use of electromagnetic simulations in teaching gives additional support for the importance of quasistatics. This activity may also motivate some change of focus in the presentation of basic electrodynamics.

Jonas Larsson

2006-06-13

196

Electromagnetic instability in holographic QCD  

E-print Network

Using the AdS/CFT correspondence, we calculate the vacuum decay rate for the Schwinger effect in confining large $N_{c}$ gauge theories. The instability is induced by the quark antiquark pair creation triggered by strong electromagnetic fields. The decay rate is obtained as the imaginary part of the Euler-Heisenberg effective Lagrangian evaluated from the D-brane action with a constant electromagnetic field in holographic QCD models such as the Sakai-Sugimoto model and the deformed Sakai-Sugimoto model. The decay rate is found to increase with the magnetic field parallel to the electric field, while it decreases with the magnetic field perpendicular to the electric field. We discuss generic features of a critical electric field as a function of the magnetic field and the QCD string tension in the Sakai-Sugimoto model.

Hashimoto, Koji; Sonoda, Akihiko

2014-01-01

197

GENETIC EFFECTS OF ELECTROMAGNETIC WAVES  

Microsoft Academic Search

The genetic effects of electromagnetic waves can be detected by different test-systems. The mutagenic effect of ionizing radiation\\u000a can be developed on the levels of DNA and\\/or chromosomes. In numerous researches efficiency of micronucleus assay, alkaline\\u000a single-cell gel electrophoresis, chromosomal aberrations test and FISH-technique and their different combinations for the\\u000a detection of ionizing radiation-induced genotoxic effects are discussed. Also some

Rouben Aroutiounian; Galina Hovhannisyan; Gennady Gasparian

198

Teaching Electromagnetism Using Advanced Technologies  

NSDL National Science Digital Library

Michael Faraday was the first to realize that the shape of electromagnetic field lines is extraordinarily expressive of their dynamical effects. We can understand intuitively many things about the forces transmitted by the fields by looking at the topology of the field lines. This is especially true when the field lines are animated. This NSF-funded site has many examples of EM field lines.

Belcher, John

2003-10-10

199

Electromagnetic Spectrum from QGP Fluid  

Microsoft Academic Search

We calculate thermal photon and electron pairdistribution from hot QCD matter produced in high energy heavy-ion collisions, based on a hydrodynamical model which is so tuned as to reproduce the recent experimental data at CERN SPS, and compare these electromagnetic spectra with experimental data given by CERN WA80 and CERES. We investigate mainly the effects of the off-shell properties of

Tetsufumi Hirano; Shin Muroya; Mikio Namiki

1997-01-01

200

Electromagnetic Spectrum of Radium D  

Microsoft Academic Search

The electromagnetic spectrum of RaD has been studied by the proportional counter spectrometry technique. The work of the Curie Laboratory on the gamma-ray spectrum has been generally confirmed. However, the presumed K x-ray lines are of much lower intensity and occur at a lower energy than previously reported. The L x-ray intensity is 22 per hundred disintegrations, indicating 0.63 conversion

P. E. Damon; R. R. Edwards

1953-01-01

201

Electromagnetic Spectrum of Am241  

Microsoft Academic Search

The electromagnetic spectrum of Am241 has been studied with a ten-inch bent-crystal spectrometer and a sodium iodide scintillation counter. Twelve gamma rays, sixteen Np L x-rays, and eight Am L x-rays have been measured. The gamma rays in Np have energies of 26.363, 33.199, 43.463, 59.568, 103, 113, 130, 159, 210, 270, 328, and 370 kev. The x-ray energies establish

Paul P. Day

1955-01-01

202

Laminated electromagnetic pump stator core  

DOEpatents

A stator core for an electromagnetic pump includes a plurality of circumferentially abutting tapered laminations extending radially outwardly from a centerline axis to collectively define a radially inner bore and a radially outer circumference. Each of the laminations includes radially inner and outer edges and has a thickness increasing from the inner edge toward the outer edge to provide a substantially continuous path adjacent the circumference. This pump is used in nuclear fission reactors. 19 figs.

Fanning, A.W.

1995-08-08

203

Dynamical Bridges: The Electromagnetic Case  

NASA Astrophysics Data System (ADS)

We present the main line of the Dynamical Bridge method applied to electromagnetic (EM) fields. In this framework, we show the equivalence between the Born- Infeld theory written in a given curved space to the Maxwell's one written in the flat space. In the limit of weak EM fields, we obtain a geometrical contribution to the anomalous magnetic moment of the leptons and, finally, we compare it with experimental data.

Bittencourt, Eduardo

2014-12-01

204

Dark Energy, Gravitation and Electromagnetism  

E-print Network

In the context of the fact that the existence of dark energy causing the accelerated expansion of the universe has been confirmed by the WMAP and the Sloan Digital Sky Survey, we re-examine gravitation itself, starting with the formulation of Sakharov and show that it is possible to obtain gravitation in terms of the electromagnetic charge of elementary particles, once the ZPF and its effects at the Compton scale are taken into account.

B. G. Sidharth

2004-01-08

205

Electromagnetic Activation of Capillary Switches  

Microsoft Academic Search

By designing coupled droplet pairs with the appropriate length scale to promote surface tension as the dominant force, one can create bi-stable capillary switches. This bi-stability can be triggered by pressure pulses, surface chemistry, electroosmosis, or body forces. To exploit the latter, we designed a capillary switch with electromagnetic activation. The resulting setup consists of a sub-millimeter tube, overfilled with

Bernie Malouin; Rohan Dayal; Leila Parsa; Amir Hirsa

2008-01-01

206

Hospital emergency room electromagnetic environment  

Microsoft Academic Search

The electromagnetic environment of the emergency room of an urban hospital was estimated, characterizing electric fields over a 4.4-day period. Measured fields did not exceed 1 V\\/m over the 0.1-1 GHz range, but exhibited substantial day-night variation. Such temporal variation was characterized with respect to intensity and frequency of emissions. The observed field level variation implied a substantial temporal variation

D. Davis; B. Skulic; B. Segal; P. Vlach; T. Pavlasek

1997-01-01

207

Analytical Prediction of Electromagnetic Environments  

Microsoft Academic Search

The problem of transmitting digital data through electromagnetic environments of high ambient-pulse density is one of growing concern. The appearance of pulsed radar in the lO-Mw range, and sensitive receivers in the - 100-dbm range, will aggravate this situation. This paper discusses three efforts made by the government to predict the status of future environments. In all cases, the basic

W. H. TETLEYt

1961-01-01

208

Genetic algorithms in engineering electromagnetics  

Microsoft Academic Search

This paper presents a tutorial and overview of genetic algorithms for electromagnetic optimization. Genetic-algorithm (GA) optimizers are robust, stochastic search methods modeled on the concepts of natural selection and evolution. The relationship between traditional optimization techniques and the GA is discussed. Step-by-step implementation aspects of the GA are detailed, through an example with the objective of providing useful guidelines for

J. Michael Johnson; V. Rahmat-Samii

1997-01-01

209

Laminated electromagnetic pump stator core  

SciTech Connect

A stator core for an electromagnetic pump includes a plurality of circumferentially abutting tapered laminations extending radially outwardly from a centerline axis to collectively define a radially inner bore and a radially outer circumference. Each of the laminations includes radially inner and outer edges and has a thickness increasing from the inner edge toward the outer edge to provide a substantially continuous path adjacent the circumference.

Fanning, Alan W. (San Jose, CA)

1995-01-01

210

Electromagnetically induced spatial light modulation  

E-print Network

We theoretically report that, utilizing electromagnetically induced transparency (EIT), the transverse spatial properties of weak probe fields can be fast modulated by using optical patterns (e.g. images) with desired intensity distributions in the coupling fields. Consequently, EIT systems can function as high-speed optically addressed spatial light modulators. To exemplify our proposal, we indicate the generation and manipulation of Laguerre-Gaussian beams based on either phase or amplitude modulation in hot vapor EIT systems.

L. Zhao; T. Wang; S. F. Yelin

2008-12-14

211

Wind measurements by electromagnetic probes  

NASA Technical Reports Server (NTRS)

The emerging technology of electromagnetic probing of the atmosphere to measure winds used in a space vehicle ascent winds load calculations is presented. The frequency range, altitude, and resolution for the following probes are presented: lidars, microwave radars, and clear-air Doppler radars (popularly known as wind profilers). The electromagnetic probing of the atmosphere by clear-air radars and lasers is the new technology to supplement balloon-borne wind sensors used to determine ascent wind loads of space vehicles. The electromagnetic probes measure the wind velocity using the Doppler effect. This is the radar technology used in MSFC's Radar Wind Profiler, and is similar to the technology used in conventional Doppler systems except that the frequency is generally lower, antenna is bigger, and dwell time much longer. Designed for unattended and automated instrumentation in providing measurements of the wind in the troposphere, the profiler employs Doppler radar technology and is currently being put in operation at NASA Kennedy Space Center, Florida.

Susko, Michael

1988-01-01

212

Electromagnetism on anisotropic fractal media  

NASA Astrophysics Data System (ADS)

Basic equations of electromagnetic fields in anisotropic fractal media are obtained using a dimensional regularization approach. First, a formulation based on product measures is shown to satisfy the four basic identities of the vector calculus. This allows a generalization of the Green-Gauss and Stokes theorems as well as the charge conservation equation on anisotropic fractals. Then, pursuing the conceptual approach, we derive the Faraday and Ampre laws for such fractal media, which, along with two auxiliary null-divergence conditions, effectively give the modified Maxwell equations. Proceeding on a separate track, we employ a variational principle for electromagnetic fields, appropriately adapted to fractal media, so as to independently derive the same forms of these two laws. It is next found that the parabolic (for a conducting medium) and the hyperbolic (for a dielectric medium) equations involve modified gradient operators, while the Poynting vector has the same form as in the non-fractal case. Finally, Maxwell's electromagnetic stress tensor is reformulated for fractal systems. In all the cases, the derived equations for fractal media depend explicitly on fractal dimensions in three different directions and reduce to conventional forms for continuous media with Euclidean geometries upon setting these each of dimensions equal to unity.

Ostoja-Starzewski, Martin

2013-04-01

213

Fluctuating electromagnetic fields of solids  

NASA Astrophysics Data System (ADS)

Various theoretical methods to calculate the spectral and correlation properties of fluctuating electromagnetic fields generated by solids are reviewed, all of which essentially reduce to solving the Maxwell equations for a specified geometry and boundary conditions and then using the fluctuation-dissipation theorem. The spectral and correlation properties of thermally stimulated fields of a system in equilibrium and out of equilibrium with surrounding bodies are described. A special attention is put to the difference between the spectral and correlation properties of the propagating and evanescent waves of the thermally stimulated fields of solids. The dispersion interaction between solid bodies in different thermodynamic states, the resonance dispersion interaction in a three-body system, the fluctuating fields as a means of body-to-body energy transfer, and the shift, broadening, and deexcitation of energy levels in a particle near a solid surface are discussed using the theory of thermally stimulated electromagnetic fields. Thermally stimulated emission of infrared radiation of semiconductor crystals and films (heated up to 150 C) on metal substrates are measured in frequency range of vibrational polaritons both for propagating waves and for evanescent waves transformed into propagating waves due to ATR prism over the samples. The experimental results on thermally stimulated electromagnetic fields from solids are in qualitative and quantitative agreement with model calculations and theoretical expectations.

Dorofeyev, I. A.; Vinogradov, E. A.

2011-07-01

214

Electromagnetic Effects in SDF Explosions  

SciTech Connect

The notion of high ion and electron concentrations in the detonation of aluminized explosive mixtures has aroused some interest in electro-magnetic effects that the SDF charges might generate when detonated. Motivated by this interest we have started to investigate whether significant electro-magnetic effects show up in our small-scale experiments. However, the design of instrumentation for this purpose is far from straightforward, since there are a number of open questions. Thus the main aim of the feasibility tests is to find - if possible - a simple and reliable method that can be used as a diagnostic tool for electro-magnetic effects. SDF charges with a 0.5-g PETN booster and a filling of 1 g aluminum flakes have been investigated in three barometric bomb calorimeters with volumes ranging from 6.3 l to of 6.6 l. Though similar in volume, the barometric bombs differed in the length-to-diameter ratio. The tests were carried out with the bombs filled with either air or nitrogen at ambient pressure. The comparison of the test in air to those in nitrogen shows that the combustion of TNT detonation products or aluminum generates a substantial increase of the quasi-steady overpressure in the bombs. Repeated tests in the same configuration resulted in some scatter of the experimental results. The most likely reason is that the aluminum combustion in most or all cases is incomplete and that the amount of aluminum actually burned varies from test to test. The mass fraction burned apparently decreases with increasing aspect ratio L/D. Thus an L/D-ratio of about 1 is optimal for the performance of shock-dispersed-fuel combustion. However, at an L/D-ratio of about 5 the combustion still yields appreciable overpressure in excess of the detonation. For a multi-burst scenario in a tunnel environment with a number of SDF charges distributed along a tunnel section a spacing of 5 tunnel diameter and a fuel-specific volume of around 7 l/g might provide an acceptable compromise between optimizing the combustion performance and keeping the number of elementary charges low. Further tests in a barometric bomb calorimeter of 21.2 l volume were performed with four types of aluminum. The mass fraction burned in this case appeared to depend on the morphology of the aluminum particles. Flake aluminum exhibited a better performance than granulated aluminum with particle sizes ranging from below 25 {micro}m to 125 {micro}m for the coarsest material. In addition, a feasibility study on electro-magnetic effects from SDF charges detonated in a tunnel has been performed. A method was developed to measure the local, unsteady electro-conductivity in the detonation/combustion products cloud. This method proved to yield reproducible results. A variety of methods were tested with regard to probing electro-magnetic pulses from the detonation of SDF charges. The results showed little reproducibility and were small compared to the effect from pulsed high voltage discharges of comparatively small energy (around 32 J). Thus either no significant electromagnetic pulse is generated in our small-scale tests or the tested techniques have to be discarded as too insensitive or too limited in bandwidth to detect possibly very high frequency electro-magnetic disturbances.

Reichenbach, H; Neuwald, P; Kuhl, A L

2010-02-12

215

Gravito-electromagnetic resonances in Minkowski space  

NASA Astrophysics Data System (ADS)

We consider the interaction between gravitational and electromagnetic radiation propagating on a Minkowski background and look into the effects of the former upon the latter. Not surprisingly, the coupling between these two sources leads to gravitationally driven electromagnetic waves. At the second perturbative level, the driving force appears as the superposition of two waves, the properties of which are decided by the initial conditions. We find that the Weyl-Maxwell interaction typically leads to electromagnetic beatlike signals and, in some cases, to the resonant amplification of the driven electromagnetic wave. For physically reasonable initial conditions, we show that these resonances imply a linear (in time) growth for the amplitude of the electromagnetic signal, with the overall amplification also depending on the strength of the driving gravity wave. Finally, we provide order-of-magnitude estimates of the achieved amplification by applying our analysis to astrophysical environments where both gravitational and electromagnetic waves are expected to coexist.

Kouretsis, Alexandros P.; Tsagas, Christos G.

2013-08-01

216

An omnidirectional electromagnetic absorber made of metamaterials  

NASA Astrophysics Data System (ADS)

In a recent theoretical work by Narimanov and Kildishev (2009 Appl. Phys. Lett. 95 041106) an optical omnidirectional light absorber based on metamaterials was proposed, in which theoretical analysis and numerical simulations showed that all optical waves hitting the absorber are trapped and absorbed. Here we report the first experimental demonstration of an omnidirectional electromagnetic absorber in the microwave frequency. The proposed device is composed of non-resonant and resonant metamaterial structures, which can trap and absorb electromagnetic waves coming from all directions spirally inwards without any reflections due to the local control of electromagnetic fields. It is shown that the absorption rate can reach 99 per cent in the microwave frequency. The all-directional full absorption property makes the device behave like an 'electromagnetic black body', and the wave trapping and absorbing properties simulate, to some extent, an 'electromagnetic black hole.' We expect that such a device could be used as a thermal emitting source and to harvest electromagnetic waves.

Cheng, Qiang; Cui, Tie Jun; Jiang, Wei Xiang; Cai, Ben Geng

2010-06-01

217

Studies on a passive electromagnetic damper  

Microsoft Academic Search

The passive electromagnetic damper has the same configuration as that of the electromagnetic bearing, but no sensors and no\\u000a closed loop control are needed. Its robustness and no-contact structure are its great advantages. When the rotor vibrates,\\u000a the electromagnetic field intensity in the air gap is altered, then fluctuating currents in the damper coils and eddy currents\\u000a inside the surface

Shui-ying Zheng; Xiao-hong Pan; Zhen-fei Ma

2006-01-01

218

Pulsed Electromagnet Emat for High Temperatures  

NASA Astrophysics Data System (ADS)

We presented recently a design of Electromagnetic Acoustic Transducer (EMAT) that uses a pulsed electromagnet to provide the required magnetic field for operation. This new EMAT exhibited a significant improvement in the generated ultrasonic signal amplitude and signal to noise ratio, for operation on mild steel samples at room temperature, compared to equivalent EMATs that use permanent magnets. Results for using the pulsed electromagnet EMAT to generate and detect shear waves in mild steel at elevated temperatures are presented here.

Hernandez-Valle, F.; Dixon, S.

2010-02-01

219

Electromagnetic interactions at RHIC and LHC  

E-print Network

At LHC energies the Lorentz factor will be 3400 for the Pb + Pb collisions and the electromagnetic interactions will play important roles. Cross sections for the electromagnetic particle productions are very large and can not be ignored for the lifetimes of the beams and background. In this article, we are going to study some of the electromagnetic processes at RHIC and LHC and show the cross section calculations of the electron-positron pair production with the giant dipole resonance of the ions.

M. C. Guclu

2008-11-15

220

Electromagnetic wave scattering by Schwarzschild black holes  

E-print Network

We analyze the scattering of a planar monochromatic electromagnetic wave incident upon a Schwarzschild black hole. We obtain accurate numerical results from the partial wave method for the electromagnetic scattering cross section, and show that they are in excellent agreement with analytical approximations. The scattering of electromagnetic waves is compared with the scattering of scalar, spinor and gravitational waves. We present a unified picture of the scattering of all massless fields for the first time.

Lus C. B. Crispino; Sam R. Dolan; Ednilton S. Oliveira

2009-05-20

221

Electromagnetic Imaging Methods for Nondestructive Evaluation Applications  

PubMed Central

Electromagnetic nondestructive tests are important and widely used within the field of nondestructive evaluation (NDE). The recent advances in sensing technology, hardware and software development dedicated to imaging and image processing, and material sciences have greatly expanded the application fields, sophisticated the systems design and made the potential of electromagnetic NDE imaging seemingly unlimited. This review provides a comprehensive summary of research works on electromagnetic imaging methods for NDE applications, followed by the summary and discussions on future directions. PMID:22247693

Deng, Yiming; Liu, Xin

2011-01-01

222

Manager's Role in Electromagnetic Interference (EMI) Control  

NASA Technical Reports Server (NTRS)

This presentation captures the essence of electromagnetic compatibility (EMC) engineering from a project manager's perspective. It explains the basics of EMC and the benefits to the project of early incorporation of EMC best practices. The EMC requirement products during a project life cycle are identified, along with the requirement verification methods that should be utilized. The goal of the presentation is to raise awareness and simplify the mystique surrounding electromagnetic compatibility for managers that have little or no electromagnetics background

Sargent, Noel B.; Lewis, Catherine C.

2013-01-01

223

Some Student Conceptions of Electromagnetic Induction  

Microsoft Academic Search

Introductory electromagnetism is a central part of undergraduate physics. Although there has been some research into student\\u000a conceptions of electromagnetism, studies have been sparse and separated. This study sought to explore second year physics\\u000a students conceptions of electromagnetism, to investigate to what extent the results from the present study are similar to\\u000a these results from other studies, and to uncover

Wai Meng Thong; Richard Gunstone

2008-01-01

224

Thin sheet casting with electromagnetic pressurization  

SciTech Connect

An apparatus, method and system for the casting of thin strips or strips of metal upon a moving chill block that includes an electromagnet located so that molten metal poured from a reservoir onto the chill block passes into the magnetic field produced by the electromagnet. The electromagnet produces a force on the molten metal on said chill block in the direction toward said chill block in order to enhance thermal contact between the molten metal and the chill block.

Walk, Steven R. (Winterport, ME); Slepian, R. Michael (Pittsburgh, PA); Nathenson, Richard D. (Pittsburgh, PA); Williams, Robert S. (Fairfield, OH)

1991-01-01

225

Electromagnetic Scattering from Foliage Camouflaged Hard Targets,  

E-print Network

Electromagnetic Scattering from Foliage Camouflaged Hard Targets, in VHF-band Mojtaba Dehmollaian. Then using this formulation, and single scattering theory the backscattered field from a camouflaged complex

Sarabandi, Kamal

226

Electromagnetic compatibility of nuclear power plants  

SciTech Connect

Lately, there has been a mounting concern about the electromagnetic compatibility of nuclear-power-plant systems mainly because of the effects due to the nuclear electromagnetic pulse, and also because of the introduction of more-sophisticated and, therefore, more-susceptible solid-state devices into the plants. Questions have been raised about the adequacy of solid-state-device protection against plant electromagnetic-interference sources and transients due to the nuclear electromagnetic pulse. In this paper, the author briefly reviews the environment, and the coupling, susceptibility, and vulnerability assessment issues of commercial nuclear power plants.

Cabayan, H.S.

1983-01-01

227

Noncontacting ultrasonic and electromagnetic HTS tape NDE  

SciTech Connect

Two noncontacting nondestructive evaluation techniques (electromagnetic and ultrasonic) for inspection of high temperature superconducting tapes are described. Results for Ag-clad BSCCO tapes are given.

Telschow, K.L.; Bruneel, F.W.; Walter, J.B.; Koo, L.S.

1996-10-01

228

Phase-space representation of electromagnetic radiometry  

NASA Astrophysics Data System (ADS)

The phase-space representation of electromagnetic radiometry is founded on the electromagnetic generalized radiance tensors, which allow overcoming the limitations due to the scalar electromagnetic generalized radiances. The fundamental quantities of both scalar generalized radiometry and classical radiometry or photometry become particular cases. The transport of measurable radiometric quantities by the electromagnetic field is described in terms of the propagation of the contributions from individual radiators and their redistribution over each wavefront on propagation. A physical meaning is given to the negative values of the generalized radiance, which gives new insights into Poynting's theory of energy transport.

Castaneda, Roman

2009-03-01

229

Detection of electromagnetic waves using MEMS antennas  

SciTech Connect

We describe the design, fabrication and characterization of simple micromechanical structures that are capable of sensing static electric time varying electromagnetic fields. Time varying electric field sensing is usually achieved using an electromagnetic antenna and a receiver. However, these antenna-based approaches do not exhibit high sensitivity over a broad frequency (or wavelength) range. An important aspect of the present work is that, in contrast to traditional antennas, the dimensions of these micromechanical oscillators can be much smaller than the wavelength of the electromagnetic wave. We characterized the fabricated micromechanical oscillators by measuring their responses to time varying electric and electromagnetic fields.

Lavrik, Nickolay V [ORNL] [ORNL; Tobin, [Oak Ridge National Laboratory (ORNL)] [Oak Ridge National Laboratory (ORNL); Bowland, Landon T [ORNL] [ORNL

2011-01-01

230

6.630 Electromagnetic Theory, Fall 2002  

E-print Network

6.630 is an introductory subject on electromagnetics, emphasizing fundamental concepts and applications of Maxwell equations. Topics covered include: polarization, dipole antennas, wireless communications, forces and energy, ...

Kong, Jin Au, 1942-

231

Calculation principles for a synchronous electromagnetic clutch  

NASA Technical Reports Server (NTRS)

A detailed explanation of the calculation principles, for a synchronous salient-pole electromagnetic clutch with lumped excitation windings is supplied by direct current. Practical recommendations are given.

Panasenkov, M. A.

1978-01-01

232

22.105 Electromagnetic Interactions, Fall 1998  

E-print Network

Principles and applications of electromagnetism, starting from Maxwell's equations, with emphasis on phenomena important to nuclear engineering and radiation sciences. Solution methods for electrostatic and magnetostatic ...

Hutchinson, I. H. (Ian H.)

233

Fundamental Properties of Electromagnetic RadiationFundamental Properties of Electromagnetic Radiation Energy is the ability to do work. In the process of doing work, energy is often transferred  

E-print Network

;Electromagnetic Spectrum Electromagnetic Spectrum The Sun produces a continuous spectrum of energy from gamma rays-ray Ultraviolet Infrared Microwave and radio waves Wavelength in meters (m) Electromagnetic SpectrumFundamental Properties of Electromagnetic RadiationFundamental Properties of Electromagnetic

234

Electromagnetic properties of massive neutrinos  

SciTech Connect

The vertex function for a virtual massive neutrino is calculated in the limit of soft real photons. A method based on employing the neutrino self-energy operator in a weak external electromagnetic field in the approximation linear in the field is developed in order to render this calculation of the vertex function convenient. It is shown that the electric charge and the electric dipole moment of the real neutrino are zero; only the magnetic moment is nonzero for massive neutrinos. A fourth-generation heavy neutrino of mass not less than half of the Z-boson mass is considered as a massive neutrino.

Dobrynina, A. A., E-mail: aleksandradobrynina@rambler.ru; Mikheev, N. V.; Narynskaya, E. N. [Demidov Yaroslavl State University (Russian Federation)] [Demidov Yaroslavl State University (Russian Federation)

2013-10-15

235

Extremely low frequency electromagnetic fields  

SciTech Connect

The authors focus on that which seems to be the central scientific issue emerging from current ELF research in epidemiology and in the laboratory; namely, can ELF electromagnetic fields interact with biological systems in such a way as to increase cancer risk The authors examine how cancer risk might be related to two reproducible biological effects of ELF exposure: effects on the pineal gland and circadian biology, and effects on calcium homeostasis in cells. Because they are concerned with the possible biological mechanisms of carcinogenesis, epidemiological studies are only briefly reviewed.

Wilson, B.W. (Pacific Northwest Lab., Richland, WA (USA). Chemical Sciences Dept.); Stevens, R.G. (Pacific Northwest Lab., Richland, WA (USA)); Anderson, L.E. (Pacific Northwest Lab., Richland, WA (USA). Life Sciences Center)

1990-01-01

236

Electromagnetic weak turbulence theory revisited  

SciTech Connect

The statistical mechanical reformulation of weak turbulence theory for unmagnetized plasmas including fully electromagnetic effects was carried out by Yoon [Phys. Plasmas 13, 022302 (2006)]. However, the wave kinetic equation for the transverse wave ignores the nonlinear three-wave interaction that involves two transverse waves and a Langmuir wave, the incoherent analogue of the so-called Raman scattering process, which may account for the third and higher-harmonic plasma emissions. The present paper extends the previous formalism by including such a term.

Yoon, P. H. [IPST, University of Maryland, College Park, Maryland 20742 (United States); Ziebell, L. F. [Instituto de Fisica, UFRGS, Porto Alegre, RS (Brazil); Gaelzer, R.; Pavan, J. [Instituto de Fisica e Matematica, UFPel, Pelotas, RS (Brazil)

2012-10-15

237

Quantum modulation against electromagnetic interference  

E-print Network

Periodic signals in electrical and electronic equipment can cause interference in nearby devices. Randomized modulation of those signals spreads their energy through the frequency spectrum and can help to mitigate electromagnetic interference problems. The inherently random nature of quantum phenomena makes them a good control signal. I present a quantum modulation method based on the random statistics of quantum light. The paper describes pulse width modulation schemes where a Poissonian light source acts as a random control that spreads the energy of the potential interfering signals. I give an example application for switching-mode power supplies and comment the further possibilities of the method.

Juan Carlos Garcia-Escartin

2014-11-26

238

Logic for electromagnetic field patterns  

E-print Network

It is assumed that the digital-like spatio-time brain activity might be caused by non-topological transformations of patterns in the cortex which is a linear, analog and active system. Such an effect can be modeled by topologically modulated spatio-time electromagnetic signals which theory is proposed in this paper. The logical operations are performed by passive components, and a theory of them is considered. Two gates of this sort are simulated. A short review on semiconductor hardware for this type of spatial digital processing and computing is given.

G. a. Kouzaev

2008-05-29

239

Electromagnetic fields and health outcomes.  

PubMed

Over the past two decades, there has been increasing interest in the biological effects and possible health outcomes of weak, low-frequency electric and magnetic fields. Epidemiological studies on magnetic fields and cancer, reproduction and neurobehavioural reactions have been presented. More recently, neurological, degenerative and heart diseases have also been reported to be related to such electromagnetic fields. Furthermore, the increased use of mobile phones worldwide has focussed interest on the possible effects of radiofrequency fields of higher frequencies. In this paper, a summary is given on electromagnetic fields and health outcomes and what policy is appropriate--"no restriction to exposure", "prudent avoidance" or "expensive interventions"? The results of research studies have not been unambiguous; studies indicating these fields as being a health hazard have been published and so were studies indicating no risk at all. In "positive" studies, different types of effects have been reported despite the use of the same study design, e.g., in epidemiological cancer studies. There are uncertainties as to exposure characteristics, e.g., magnetic field frequency and exposure intermittence, and not much is known about possible confounding or effect-modifying factors. The few animal cancer studies reported have not given much help in risk assessment; and in spite of a large number of experimental cell studies, no plausible and understandable mechanisms have been presented by which a carcinogenic effect could be explained. Exposure to electromagnetic fields occurs everywhere: in the home, at work, in school, etc. Wherever there are electric wires, electric motors and electronic equipment, electromagnetic fields are created. This is one of the reasons why exposure assessment is difficult. For epidemiologists, the problems is not on the effect side as registers of diseases exist in many countries today. The problem is that epidemiologists do not know the relevant exposure characteristics to be used in their studies. In international guidelines, limits for restrictions of field exposure are several orders of magnitude above what can be measured from overhead power lines and found in "electrical" occupations. These guidelines emphasize that the state of scientific knowledge today does not warrant limiting exposure levels for the public and the work force, and that further data are required to confirm whether health hazards are present. In some countries, however, the "principle of caution" or "prudent avoidance" has been adopted; meaning the low-cost avoidance of unnecessary exposure as long as there is scientific uncertainty about its health effects. PMID:11603131

Knave, B

2001-09-01

240

Electromagnetic effects on transportation systems  

SciTech Connect

Electronic and electrical system protection design can be used to eliminate deleterious effects from lightning, electromagnetic interference, and electrostatic discharges. Evaluation of conventional lightning protection systems using advanced computational modeling in conjunction with rocket-triggered lightning tests suggests that currently used lightning protection system design rules are inadequate and that significant improvements in best practices used for electronic and electrical system protection designs are possible. A case study of lightning induced upset and failure of a railway signal and control system is sketched.

Morris, M.E.; Dinallo, M.A.

1996-05-01

241

Introduction to the special issue on high-power electromagnetics (HPEM) and intentional electromagnetic interference (IEMI)  

Microsoft Academic Search

A new threat to civil society has recently emerged. It is known as intentional electromagnetic interference (IEMI) and covers the threat of intense electromagnetic disturbances that may be applied to the sophisticated electronic systems that are so important to our daily lives. This paper provides a brief background for the threat, defines important terms, describes the different types of electromagnetic

William A. Radasky; Carl E. Baum; Manuem W. Wik

2004-01-01

242

Special Section --Marine Controlled-Source Electromagnetic Methods 2D marine controlled-source electromagnetic modeling  

E-print Network

Special Section -- Marine Controlled-Source Electromagnetic Methods 2D marine controlled-source electromagnetic modeling: Part 1 -- An adaptive finite-element algorithm Yuguo Li1 and Kerry Key1 ABSTRACT In Part of the frequency-domain, ma- rine controlled-source electromagnetic CSEM response of a 2D conductivity structure

Key, Kerry

243

Electromagnetic scattering from buried objects  

SciTech Connect

Radar imaging and detection of objects buried in soil has potentially important applications in the areas of nonproliferation of weapons, environmental monitoring, hazardous-waste site location and assessment, and even archeology. In order to understand and exploit this potential, it is first necessary to understand how the soil responds to an electromagnetic wave, and how targets buried within the soil scatter the electromagnetic wave. We examine the response of the soil to a short pulse, and illustrate the roll of the complex dielectric permittivity of the soil in determining radar range resolution. This leads to a concept of an optimum frequency and bandwidth for imaging in a particular soil. We then propose a new definition for radar cross section which is consistent with the modified radar equation for use with buried targets. This radar cross section plays the same roll in the modified radar equation as the traditional radar cross section does in the free-space radar equation, and is directly comparable to it. The radar cross section of several canonical objects in lossy media is derived, and examples are given for several object/soil combinations.

Brock, B.C.; Sorensen, K.W.

1994-10-01

244

Parameters characterizing electromagnetic wave polarization  

NASA Astrophysics Data System (ADS)

In this paper, generalizations of the Stokes parameters and alternative characterizations of three-dimensional (3D) time-varying electromagnetic fields is introduced. One of these characteristics is the normal of the polarization plane, which, in many cases of interest, is parallel (or antiparallel) to the direction of propagation. Others are the two spectral density Stokes parameters which describe spectral intensity and circular polarization. The analysis is based on the spectral density tensor. This tensor is expanded in a base composed of the generators of the SU(3) symmetry group, as given by Gell-Mann and Y. Ne'eman [The Eight-fold Way (Benjamin, New York, 1964)] and the coefficients of this expansion are identified as generalized spectral density polarization parameters. The generators have the advantage that they obey the same algebra as the Pauli spin matrices, which is the base for expanding the 2D spectral density tensor with the Stokes parameters as coefficients. The polarization parameters introduced are formulated in the frequency domain, thereby further generalizing the theory to allow for wide-band electromagnetic waves in contrast to the traditional quasi-monochromatic formulation.

Carozzi, T.; Karlsson, R.; Bergman, J.

2000-02-01

245

Electromagnetic probes of the QGP  

E-print Network

We investigate the properties of the QCD matter across the deconfinement phase transition in the scope of the parton-hadron string dynamics (PHSD) transport approach. We present here in particular the results on the electromagnetic radiation, i.e. photon and dilepton production, in relativistic heavy-ion collisions. By comparing our calculations for the heavy-ion collisions to the available data, we determine the relative importance of the various production sources and address the possible origin of the observed strong elliptic flow $v_2$ of direct photons. We argue that the different centrality dependence of the hadronic and partonic sources for direct photon production in nucleus-nucleus collisions can be employed to shed some more light on the origin of the photon $v_2$ "puzzle". While the dilepton spectra at low invariant mass show in-medium effects like an enhancement from multiple baryonic resonance formation or a collisional broadening of the vector meson spectral functions, the dilepton yield at high invariant masses (above 1.1 GeV) is dominated by QGP contributions for central heavy-ion collisions at ultra-relativistic energies. This allows to have an independent view on the parton dynamics via their electromagnetic massive radiation.

E. L. Bratkovskaya; O. Linnyk; W. Cassing

2014-09-15

246

Electromagnetic wave energy conversion research  

NASA Technical Reports Server (NTRS)

Known electromagnetic wave absorbing structures found in nature were first studied for clues of how one might later design large area man-made radiant-electric converters. This led to the study of the electro-optics of insect dielectric antennae. Insights were achieved into how these antennae probably operate in the infrared 7-14um range. EWEC theoretical models and relevant cases were concisely formulated and justified for metal and dielectric absorber materials. Finding the electromagnetic field solutions to these models is a problem not yet solved. A rough estimate of losses in metal, solid dielectric, and hollow dielectric waveguides indicates future radiant-electric EWEC research should aim toward dielectric materials for maximum conversion efficiency. It was also found that the absorber bandwidth is a theoretical limitation on radiant-electric conversion efficiency. Ideally, the absorbers' wavelength would be centered on the irradiating spectrum and have the same bandwith as the irradiating wave. The EWEC concept appears to have a valid scientific basis, but considerable more research is needed before it is thoroughly understood, especially for the complex randomly polarized, wide band, phase incoherent spectrum of the sun. Specific recommended research areas are identified.

Bailey, R. L.; Callahan, P. S.

1975-01-01

247

Electromagnetic Methods of Lightning Detection  

NASA Astrophysics Data System (ADS)

Both cloud-to-ground and cloud lightning discharges involve a number of processes that produce electromagnetic field signatures in different regions of the spectrum. Salient characteristics of measured wideband electric and magnetic fields generated by various lightning processes at distances ranging from tens to a few hundreds of kilometers (when at least the initial part of the signal is essentially radiation while being not influenced by ionospheric reflections) are reviewed. An overview of the various lightning locating techniques, including magnetic direction finding, time-of-arrival technique, and interferometry, is given. Lightning location on global scale, when radio-frequency electromagnetic signals are dominated by ionospheric reflections, is also considered. Lightning locating system performance characteristics, including flash and stroke detection efficiencies, percentage of misclassified events, location accuracy, and peak current estimation errors, are discussed. Both cloud and cloud-to-ground flashes are considered. Representative examples of modern lightning locating systems are reviewed. Besides general characterization of each system, the available information on its performance characteristics is given with emphasis on those based on formal ground-truth studies published in the peer-reviewed literature.

Rakov, V. A.

2013-11-01

248

Millimeter Waves: Acoustic and Electromagnetic  

PubMed Central

This article is the presentation I gave at the D'Arsonval Award Ceremony on June 14, 2011 at the Bioelectromagnetics Society Annual Meeting in Halifax, Nova Scotia. It summarizes my research activities in acoustic and electromagnetic millimeter waves over the past 47 years. My earliest research involved acoustic millimeter waves, with a special interest in diagnostic ultrasound imaging and its safety. For the last 21 years my research expanded to include electromagnetic millimeter waves, with a special interest in the mechanisms underlying millimeter wave therapy. Millimeter wave therapy has been widely used in the former Soviet Union with great reported success for many diseases, but is virtually unknown to Western physicians. I and the very capable members of my laboratory were able to demonstrate that the local exposure of skin to low intensity millimeter waves caused the release of endogenous opioids, and the transport of these agents by blood flow to all parts of the body resulted in pain relief and other beneficial effects. PMID:22926874

Ziskin, Marvin C.

2012-01-01

249

Electromagnetic Visibility and Invisibility Massachusetts Institute of Technology  

E-print Network

Electromagnetic Visibility and Invisibility Ting Zhou Massachusetts Institute of Technology of determining the internal properties of a medium by mak- ing electromagnetic measurements at the boundary- neous isotropic electromagnetic background medium using the enclosure method. The second part

Ciocan-Fontanine, Ionut

250

Electromagnets 1: Turn on the Power. Science in a Box.  

ERIC Educational Resources Information Center

The article presents inexpensive activities to teach elementary school students about electromagnets. Students learn to make an electromagnet with a battery, nail, and wire, then different activities help them explore the difference between permanent magnets and electromagnets. (SM)

Whitman, Betsy Blizard

1992-01-01

251

THE ELECTROMAGNETIC INTERIOR TRANSMISSION PROBLEM FOR REGIONS WITH CAVITIES  

E-print Network

THE ELECTROMAGNETIC INTERIOR TRANSMISSION PROBLEM FOR REGIONS WITH CAVITIES ANNE COSSONNI`ERE AND HOUSSEM HADDAR Abstract. We consider the electromagnetic interior transmission problem in the case when address the configuration where the electromagnetic permeability is constant while the electric

Boyer, Edmond

252

AN ELECTROMAGNETIC INVERSE PROBLEM IN CHIRAL STEPHEN R. MCDOWALL  

E-print Network

AN ELECTROMAGNETIC INVERSE PROBLEM IN CHIRAL MEDIA STEPHEN R. MCDOWALL Abstract. We consider determines the electromagnetic parameters, namely the conductivity, electric permittivity, magnetic to the electromagnetic fields, the equations governing these fields change from a single second order elliptic partial

McDowall, Stephen

253

THE ELECTROMAGNETIC INVERSE SCATTERING PROBLEM FOR PARTIALLY COATED LIPSCHITZ DOMAINS  

E-print Network

THE ELECTROMAGNETIC INVERSE SCATTERING PROBLEM FOR PARTIALLY COATED LIPSCHITZ DOMAINS FIORALBA electromagnetic plane wave and the electric far field pattern of the scattered wave. A justification is given method. Key words. Electromagnetic inverse scattering, Lipschitz domain, mixed boundary conditions

Cakoni, Fioralba

254

Symmetries and currents of massless neutrino fields, electromagnetic and  

E-print Network

] obtained for the electromagnetic case s = 1. As this classification uses the spinorial formulation Symmetries and currents of massless neutrino fields, electromagnetic interesting cases, are also presented in tensorial form for electromagnetic and graviton fields

Pohjanpelto, Juha

255

Elsevier Science 1 Particle identification with the ATLAS electromagnetic  

E-print Network

Elsevier Science 1 Particle identification with the ATLAS electromagnetic calorimeter Sylvain The design constraints and the target performances of the ATLAS electromagnetic calorimeter are reviewed detector, are summarized. Some recent updates concerning the use of the electromagnetic calorimeter

Boyer, Edmond

256

The Inverse Electromagnetic Scattering Problem for Anisotropic Media  

E-print Network

The Inverse Electromagnetic Scattering Problem for Anisotropic Media Fioralba Cakoni1 , David. The inverse electromagnetic scattering problem for anisotropic media plays a special role in inverse. Introduction The inverse electromagnetic scattering problem for anisotropic media plays a special role

Cakoni, Fioralba

257

ELECTROMAGNETIC SUBSURFACE IMAGING AT VLF WITH DISTRIBUTED OPTIMIZATION  

E-print Network

that are considered interference. We formulate electromagnetic subsurface imaging as an optimization problem conELECTROMAGNETIC SUBSURFACE IMAGING AT VLF WITH DISTRIBUTED OPTIMIZATION A DISSERTATION SUBMITTED to electromagnetic subsurface imaging. We describe a signal processing technique, known as sparse separation

258

Understanding stable levitation of superconductors from intermediate electromagnetics  

E-print Network

Understanding stable levitation of superconductors from intermediate electromagnetics A. Bad for electromagnetic energy related quantities. Comprehensible illustrations, based on the calculated lines of magnetic at students who have followed an intermediate course on Electromagnetics and have some background in Classical

Majós, Antonio Badía

259

Long Pulse Fusion Physics Experiments Without Superconducting Electromagnets  

E-print Network

Long Pulse Fusion Physics Experiments Without Superconducting Electromagnets Robert D. Woolley fusion physics experiments can be performed economically via resistive electromagnets designed for thermally steady-state operation. Possible fusion experiments using resistive electromagnets include long

260

College of Engineering Electromagnetically Enhanced Hydrocyclone for Magnetite Separation during  

E-print Network

PENNSTATE College of Engineering Electromagnetically Enhanced Hydrocyclone for Magnetite Separation, but pose a safety risk due to the constant magnetic field. The Spring 2011 team des electromagnetic Electromagnetically Enhanced Hydrocyclone for Magnetite Separation during Coal Beneficiation Magnetite is used

Demirel, Melik C.

261

Electromagnetic signature of human cortical dynamics during wakefulness and sleep  

E-print Network

Electromagnetic signature of human cortical dynamics during wakefulness and sleep Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 2.5 Spatial reach of LFP & Electromagnetic Lead field . . . . . . . . . . . . . . . 35 2 Studies 45 4 Overview 47 4.1 Electromagnetic properties of the extracellular medium

Destexhe, Alain

262

Long Pulse Fusion Physics Experiments Without Superconducting Electromagnets  

E-print Network

Long Pulse Fusion Physics Experiments Without Superconducting Electromagnets Robert D. Woolley fusion physics experiments can be performed economically via resistive electromagnets designed for thermally steady­state operation. Possible fusion experiments using resistive electromagnets include long

263

Marine Electromagnetic Studies of Seafloor Resources and Tectonics  

E-print Network

Marine Electromagnetic Studies of Seafloor Resources and Tectonics Kerry Key Received: 3 December been a period of rapid growth for marine electromagnetic (EM) methods, predominantly due physical and geo- logical insights learned from recent data sets. Keywords Marine electromagnetics Á

Key, Kerry

264

Improved Magnetic Fusion Energy Economics Via Massive Resistive Electromagnets  

E-print Network

Improved Magnetic Fusion Energy Economics Via Massive Resistive Electromagnets Robert D. Woolley using superconducting electromagnets, the recirculating power fraction needed to operate resistive electromagnets can be made as close to zero as needed for economy without requiring superconductors. Other

265

Electromagnetic formulation of global gyrokinetic particle simulation in toroidal geometry  

E-print Network

Electromagnetic formulation of global gyrokinetic particle simulation in toroidal geometry I. Holod online 9 December 2009 The fluid-kinetic hybrid electron model for global electromagnetic gyrokinetic the capabilities to describe low frequency processes in electromagnetic turbulence with electron dynamics

Lin, Zhihong

266

DETECTING UNEXPLODED ORDNANCE WITH TIME DOMAIN ELECTROMAGNETIC Leonard Rodriguez Pasion  

E-print Network

DETECTING UNEXPLODED ORDNANCE WITH TIME DOMAIN ELECTROMAGNETIC INDUCTION By Leonard Rodriguez Assumption '(')'(')'('(')'('(')'('(')'('(')'('(')'(')'('(')'('(')'(' 10 2.2 Electromagnetic Induction;Abstract In this thesis I assume that the Time Domain Electromagnetic (TEM) response of a buried axisymmet

Oldenburg, Douglas W.

267

The physical optics method in electromagnetic scattering  

Microsoft Academic Search

The purpose of this work is to analyze the physical optics method as applied to electromagnetic scattering theory and to point out its physical and mathematical drawbacks. The main conclusions are (1) that the boundary values assumed by physical optics lead to electromagnetic fields that do not satisfy the finiteness of energy condition and, as a consequence, that integral representations

John S. Asvestas

1980-01-01

268

Electromagnetic Attenuation by Solid Particle Aerosols  

Microsoft Academic Search

Theories of electromagnetic attenuation by absorption and scattering from aerosols of solid particles were evaluated and experimentally verified. Particles having specific physical and morphological properties were tested to maximize the mass extinction coefficients of the aerosols in several bands of the electromagnetic spectrum. Particulate materials were chosen based on theoretical predictions and compatible aerosolization schemes were developed for each material.

Erica Ray Petersen

1991-01-01

269

Suppressing electromagnetic interference in direct current converters  

Microsoft Academic Search

Since James Clerk Maxwell established the electromagnetic field theory in 1865, multifarious electrical and electronic products have been invented, designed, produced, and widely deployed, such as wireless communication devices, electrical machines and motors. This has profoundly changed our world and our lives. Now we cannot live without electrical products anymore and, thus, we are surrounded with electromagnetic fields generated. On

Hong Li; Zhong Li; Bo Zhang; Wallace Tang; Wolfgang Halang

2009-01-01

270

Electromagnetic concepts in mathematical representation of physics  

NSDL National Science Digital Library

This articles addresses the use of mathematics when studying the physics of electromagnetism. The authors focus on common electromagnetic concepts and their associated mathematical representation and arithmetical tools. The authors conclude that most students do not understand the significant aspects of physical situations and have difficulty using relationships and models specific to magnetic phenomenon.

Albe, Virginie; Venturini, Patrice; Lascours, Jean

2006-12-06

271

Electromagnetic fast firing for ultrashallow junction formation  

Microsoft Academic Search

The creation of low resistivity, ultrashallow source\\/drain regions in MOS device structures requires rapid thermal processing (RTP) techniques that restrict diffusion and activate a significant percentage of the implanted dopant species. While current heating techniques depend upon illumination based heating, a new technology, electromagnetic induction heating (EMIH), achieves a rapid heating of the silicon by coupling electromagnetic radiation directly into

Keith Thompson; John H. Booske; Reid F. Cooper; Yogesh B. Gianchandani

2003-01-01

272

Enhanced electromagnetic emission from a dusty plasma  

Microsoft Academic Search

It is shown how enhanced electromagnetic emission (EEE) is induced when large amplitude electromagnetic waves scatter off acoustic-like modes in a dusty plasma. Following the formalism of standard parametric interactions and using the Rostoker superposition principle, a general expression for the ensemble average of the square of the vector potential of EEE is derived. The result should be useful in

P. K. Shukla; L. Stenflo; D. P. Resendes

2002-01-01

273

Diffraction of Electromagnetic Waves in Dusty Magnetoplasma  

Microsoft Academic Search

It is known, that the plasma in an external magnetic field (magnetoplasma) becomes anisotropy. For example, the Earth ionosphere has such properties. It's possible to present the interaction of electromagnetic waves with dusty magnetoplasma as a diffraction of electromagnetic waves on the macroscopic particles located in the anisotropic plasma. This problem solved by a method of the integral equations of

Andrey Yatsenko; Nikolay Gorobets

2008-01-01

274

NASA Applications for Computational Electromagnetic Analysis  

NASA Technical Reports Server (NTRS)

Computational Electromagnetic Software is used by NASA to analyze the compatibility of systems too large or too complex for testing. Recent advances in software packages and computer capabilities have made it possible to determine the effects of a transmitter inside a launch vehicle fairing, better analyze the environment threats, and perform on-orbit replacements with assured electromagnetic compatibility.

Lewis, Catherine C.; Trout, Dawn H.; Krome, Mark E.; Perry, Thomas A.

2011-01-01

275

Quantization of Electromagnetic Fields in Cavities  

NASA Technical Reports Server (NTRS)

A quantization procedure for the electromagnetic field in a rectangular cavity with perfect conductor walls is presented, where a decomposition formula of the field plays an essential role. All vector mode functions are obtained by using the decomposition. After expanding the field in terms of the vector mode functions, we get the quantized electromagnetic Hamiltonian.

Kakazu, Kiyotaka; Oshiro, Kazunori

1996-01-01

276

2002 by CRC Press LLC Electromagnetic  

E-print Network

© 2002 by CRC Press LLC 17 Electromagnetic Vector Sensors with Beamforming Applications* 17.1 Introduction Advantages of Using Electromagnetic Vector Sensors · Historical Development · Contents-Message Signal · Assumptions · Performance Measures · A Useful Result 17.3 Signal to Interference

Nehorai, Arye

277

Studies Of Apnea Monitor Radiofrequency Electromagnetic Interference  

Microsoft Academic Search

Reports that radiofrequency (RF) electromagnetic interference (EMI) was responsible for infant apnea (breath cessation) monitor disfunction have prompted an in-depth engineering investigation by the Center for Devices and Radiological Health (CDRH). Two studies were undertaken using several apnea monitors currently in use in the U.S. A laboratory study was done under controlled, repeatable conditions using a transverse electromagnetic (\\

P. S. Ruggera; Eugene R O'Bryan

1991-01-01

278

Yurij Yaremko Interference of outgoing electromagnetic waves  

E-print Network

i i ¡ ¢ £ ¤¥ I I ' & $ % Yurij Yaremko Interference of outgoing electromagnetic waves, i "i" iii . , i- i i-i i, - i i i, i i i, . - , ii (i 'i i-i) i i . Interference of outgoing electromagnetic waves generated by two point-like sources Yu.Yaremko Abstract. An energy

279

Narrow field electromagnetic sensor system and method  

DOEpatents

A narrow field electromagnetic sensor system and method of sensing a characteristic of an object provide the capability to realize a characteristic of an object such as density, thickness, or presence, for any desired coordinate position on the object. One application is imaging. The sensor can also be used as an obstruction detector or an electronic trip wire with a narrow field without the disadvantages of impaired performance when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter for transmitting a sequence of electromagnetic signals in response to a transmit timing signal, a receiver for sampling only the initial direct RF path of the electromagnetic signal while excluding all other electromagnetic signals in response to a receive timing signal, and a signal processor for processing the sampled direct RF path electromagnetic signal and providing an indication of the characteristic of an object. Usually, the electromagnetic signal is a short RF burst and the obstruction must provide a substantially complete eclipse of the direct RF path. By employing time-of-flight techniques, a timing circuit controls the receiver to sample only the initial direct RF path of the electromagnetic signal while not sampling indirect path electromagnetic signals. The sensor system also incorporates circuitry for ultra-wideband spread spectrum operation that reduces interference to and from other RF services while allowing co-location of multiple electronic sensors without the need for frequency assignments.

McEwan, Thomas E. (Livermore, CA)

1996-01-01

280

Space-time Curvature of Classical Electromagnetism  

E-print Network

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.

R. W. M. Woodside

2004-10-08

281

Wavelets and electromagnetic power system transients  

Microsoft Academic Search

The wavelet transform is introduced as a method for analyzing electromagnetic transients associated with power system faults and switching. This method, like the fourier transform, provides information related to the frequency composition of a waveform, but it is more appropriate than the familiar Fourier methods for the non-periodic, wide-band signals associated with electromagnetic transients. It appears that the frequency domain

D. C. Robertson; O. I. Camps; J. S. Mayer; W. B. Gish

1996-01-01

282

Electromagnetic corrections to light hadron masses  

E-print Network

At the precision reached in current lattice QCD calculations, electromagnetic effects are becoming numerically relevant. We will present preliminary results for electromagnetic corrections to light hadron masses, based on simulations in which a $\\mathrm{U}(1)$ degree of freedom is superimposed on $N_f=2+1$ QCD configurations from the BMW collaboration.

A. Portelli; S. Drr; Z. Fodor; J. Frison; C. Hoelbling; S. D. Katz; S. Krieg; T. Kurth; L. Lellouch; T. Lippert; K. K. Szab; A. Ramos

2010-11-18

283

Upper High School Students' Understanding of Electromagnetism  

ERIC Educational Resources Information Center

Although electromagnetism is an important component of upper secondary school physics syllabuses in many countries, there has been relatively little research on students' understanding of the topic. A written test consisting of 16 diagnostic questions was developed and used to survey the understanding of electromagnetism of upper secondary school

Saglam, Murat; Millar, Robin

2006-01-01

284

Electromagnetic Modelling of Superconducting Sensor Designs  

E-print Network

DEPARTMENT OF MATERIALS SCIENCE AND METALLURGY Electromagnetic Modelling of Superconducting Sensor Designs Guido Gerra Clare Hall, University of Cambridge 1 Preface The present dissertation has been submitted... small changes in the current circulating in it to the magnetic field the SQUID is subjected to. This possibility arises from the dynamics of electromagnetic fields in superconductors combined with the Josephson effect, and appropriate coupling schemes...

Gerra, Guido

285

Electromagnetic Concepts in Mathematical Representation of Physics.  

ERIC Educational Resources Information Center

Addresses the use of mathematics when studying the physics of electromagnetism. Focuses on common electromagnetic concepts and their associated mathematical representation and arithmetical tools. Concludes that most students do not understand the significant aspects of physical situations and have difficulty using relationships and models specific

Albe, Virginie; Venturini, Patrice; Lascours, Jean

2001-01-01

286

The Teaching of Electromagnetism at University Level  

ERIC Educational Resources Information Center

Discusses different kinds of material presentation in the teaching of electromagnetism at the university level, including three "classical" approaches and the Keller personalized proctorial system. Indicates that a general introduction to generators and motors may be useful in an electromagnetism course. (CC)

Houldin, J. E.

1974-01-01

287

The electromagnetic environment: implications for bodywork  

Microsoft Academic Search

Rhythmically changing electric, magnetic and electromagnetic fields are ubiquitous in our environment. Some of these fields are natural, others are produced by household appliances and technologies (see Part 1). Many people are adversely affected by natural and\\/or artificial energy fields (clinically termed weather or electromagnetic sensitivity). Often affected individuals. do not recognize the sources of their ailments. Disturbances in geomagnetic

James L. Oschman

2000-01-01

288

Classification of intentional electromagnetic environments (IEME)  

Microsoft Academic Search

One can classify potential intentional electromagnetic environments (IEME) threat environments into four categories, based on frequency coverage. Yet another way of categorizing IEME is based on the level of sophistication of the underlying technologies involved in producing the electromagnetic environment, as low, medium, and high-tech systems. A third way of classifying IEME is by the effects that it can have

D. V. Giri; F. M. Tesche

2004-01-01

289

Optimizing Electromagnetic Hotspots in Plasmonic Bowtie Nanoantennae  

E-print Network

Optimizing Electromagnetic Hotspots in Plasmonic Bowtie Nanoantennae Stephanie Dodson, Mohamed for their effects on the optical and electromagnetic properties. Bowties were characterized using LSPR, SERS of the sensitivity of plasmonic devices to their dielectric environment to detect binding events between biomolecules

Xiong, Qihua

290

Electromagnetic Propagation Modeling in Office Environment  

E-print Network

Electromagnetic Propagation Modeling in Office Environment Z. Sayegh1,3 M. Latrach1 F. Costen2 G the electromagnetic fields in time domain at any locations in the environment, field distribution in spatial domain is more and more needed for optimal indoor coverage in complex environment (such as offices, classrooms

Paris-Sud XI, Université de

291

Seismic and electromagnetic tunnel detection investigation  

Microsoft Academic Search

This report describes the major areas of tunnel detection investigations conducted by USAMERDC during the period December 1966 through December 1969. A short discussion of the tunnel problem is presented, and two technical approaches, seismic and electromagnetic, are discussed. Both seismic and electromagnetic detector systems were developed and evaluation tests were conducted to determine capabilities and limitations of the devices.

H. F. Knauf

1975-01-01

292

Project Physics Tests 4, Light and Electromagnetism.  

ERIC Educational Resources Information Center

Test items relating to Project Physics Unit 4 are presented in this booklet. Included are 70 multiple-choice and 22 problem-and-essay questions. Concepts of light and electromagnetism are examined on charges, reflection, electrostatic forces, electric potential, speed of light, electromagnetic waves and radiations, Oersted's and Faraday's work,

Harvard Univ., Cambridge, MA. Harvard Project Physics.

293

Electromagnetic Induction Rediscovered Using Original Texts.  

ERIC Educational Resources Information Center

Describes a teaching unit on electromagnetic induction using historic texts. Uses some of Faraday's diary entries from 1831 to introduce the phenomenon of electromagnetic induction and teach about the properties of electricity, of taking conclusions from experiment, and scientific methodology. (ASK)

Barth, Michael

2000-01-01

294

Series and Parallel Experimenting with Electromagnets  

Microsoft Academic Search

The pull of electromagnets on weights acts through the magnetism evoked in iron by current flowing in wires coiled around that iron. Learning to work with this instrument entails engaging with how effects of current show different behavior under series and parallel connections of the wire windings. This experience was new for Joseph Henry when, around 1830, he devised electromagnets

Elizabeth Cavicchi

295

Signal characteristics from electromagnetic cascades in ice  

NASA Astrophysics Data System (ADS)

We investigate the development of electromagnetic cascades in ice using a GEANT Monte Carlo simulation. We examine the Cherenkov pulse that is generated by the charge excess that develops and propagates with the shower. This study is important for the RICE experiment at the South Pole, as well as any test beam experiment which seeks to measure coherent Cherenkov radiation from an electromagnetic shower. .

Razzaque, Soebur; Seunarine, Surujhdeo; Besson, David Z.; McKay, Douglas W.

2001-07-01

296

Limits on new forces coexisting with electromagnetism  

SciTech Connect

We consider the limits arising from different electromagnetic systems on the existence of a possible new electromagnetic analogue of the fifth force. Although such a force may have no intrinsic connection to electromagnetism (or gravity), its effects could be manifested through various anomalies in electromagnetic systems, for appropriate values of the coupling strength and range. Our work generalizes that of Bartlett and Loegl (who considered the case of a massive vector field coexisting with massless electrodynamics) to encompass a broad class of phenomenological interactions mediated by both scalar and vector exchanges. By combining data from both gravitational and electromagnetic systems, one can eventually set limits on a new force whose range [lambda] extends from the subatomic scale ([lambda][approx]10[sup [minus]15] m) to the astrophysical scale ([lambda][approx]10[sup 12] m).

Kloor, H.; Fischbach, E.; Talmadge, C. (Physics Department, Purdue University, West Lafayette, Indiana 47907 (United States)); Greene, G.L. (National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States))

1994-02-15

297

Electromagnetic field with constraints and Papapetrou equation  

E-print Network

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.

Z. Ya. Turakulov; A. T. Muminov

2006-01-12

298

Charging Ahead: An Introduction to Electromagnetism  

NSDL National Science Digital Library

Charging Ahead: An Introduction to Electromagnetism is a set of hands-on activities designed to help teachers introduce middle and high school students to electromagnetism, one of the most fascinating and life changing phenomenon humankind has witnessed. In 1820, Hans Oersted, a Danish physicist and school teacher, discovered that an electrical current produces magnetism. This set the stage for the development of the electrical motor and generating electricity from motion and magnets. Charging Ahead uses readily available materials to introduce students to electromagnetism, to the factors that determine the strength of electrical coils, to the application of electromagnetism in the construction of an electrical motor, and to the production of electricity through the construction of a generator. Throughout the book, students are introduced to historical perspectives and to technological applications (circuit breakers, mag-lev trains, superconducting generators, etc.) of electromagnetism.

Schafer, Larry E.

2001-01-01

299

Noninvasive valve monitor using alternating electromagnetic field  

DOEpatents

One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

Eissenberg, D.M.; Haynes, H.D.; Casada, D.A.

1993-03-16

300

Electromagnetic effects on quasilinear turbulent particle transport  

SciTech Connect

It is well known that a nonadiabatic part of the electron density response is needed for particle transport in tokamaks. Such main reactive effects are electron trapping and electromagnetic induction. Although electron trapping has been studied rather extensively, electromagnetic effects have hardly been studied at all although they are already included in transport codes. Here the electromagnetic effects have been analyzed and parameter studies have been performed, showing that an electromagnetic particle pinch may appear in the flat density regime, just as for the case of electron trapping although the conditions are more restrictive. The particle pinch is particularly sensitive to the direction of propagation of the eigenmode. The electromagnetic particle flux is found to be outward for modes propagating in the ion drift direction and inward for modes propagating in the electron drift direction. A pinch may be obtained rather close to the axis for International Thermonuclear Experimental Reactor simulation data.

Eriksson, Annika; Weiland, Jan [Radio and Space Science, Chalmers University of Technology and EURATOM-VR Association, S-412 96 Goeteborg (Sweden)

2005-09-15

301

Noninvasive valve monitor using alternating electromagnetic field  

DOEpatents

One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

Eissenberg, David M. (Oak Ridge, TN); Haynes, Howard D. (Knoxville, TN); Casada, Donald A. (Knoxville, TN)

1993-01-01

302

Progress In Electromagnetics Research Symposium Proceedings, Marrakesh, Morocco, Mar. 2023, 2011 305 Asymmetrical Stripline Based Method for the Electromagnetic  

E-print Network

Progress In Electromagnetics Research Symposium Proceedings, Marrakesh, Morocco, Mar. 20­23, 2011 305 Asymmetrical Stripline Based Method for the Electromagnetic Characterization of Metamaterials S. G, France Abstract-- An experimental method for obtaining the effective electromagnetic parameters

Brest, Université de

303

Electromagnetic studies in geothermal regions  

NASA Astrophysics Data System (ADS)

During the past 25 yr, nearly all available electromagnetic and geoelectric techniques have been tested for their usefulness in geothermal exploration and exploitation. Dipole-dipole profiling, audiomagnetotellurics and controlled source electromagnetic methods are examples of those which have proven to be rather efficient for geothermal exploration. From the hundreds of field surveys which have been performed in many geothermal regions of the world, a large variety of geothermal regions and local geothermal systems, with different geological, hydrological and heat transfer characteristics, has been found to exist. Depending on the combination of these different characteristics each geothermal region or system presents a new problem which may need a different field technique or group of field techniques for optimal exploration. Despite these problems, new geothermal regions have been detected and structures and processes in geothermal systems are now much better understood. For example, advances have been made in the study of (a) the characteristics of porous/permeable hot water/vapor reservoirs and of fractioned zones for hot water/vapor circulation and production (b) the distribution and movement of cold meteoric and of hot water (c) the thermal insulation of reservoirs by cap-rocks (d) convective and/or conductive heat transfer and (e) the thermal influence of magma intrusions to high crustal levels. New exploration techniques, data analysis procedures and model calculations have been developed in the course of research in geothermal areas. They include the controlled source electromagnetic methods, the remote reference field technique and the development of better and faster algorithms for direct and inverse model calculations. Problems for the future are (a) the development and improvement of equipment and field techniques for more precise delineation and resolution of the conductivity distribution in geothermal areas especially those with productive zones of high porosity/permeability and fracturing, (b) the improvement of computerised data analysis in the field to optimise progress during the field measurements and (c) the development of more efficient interpretation procedures for the rather inhomogeneous conductivity distribution which exists in most geothermal areas.

Berktold, A.

1983-07-01

304

Modelling of electromagnetic shielding structures for radiated EMI analysis.  

E-print Network

??Electromagnetic (EM) shielding has been used extensively in electronic products to reduce the radiated electromagnetic interference (EMI) from high-speed digital circuits so that the products (more)

Wang, Zheng.

2008-01-01

305

12 Current approaches to mapping language in electromagnetic space  

E-print Network

12 Current approaches to mapping language in electromagnetic space Marta Kutas, Kara D. Federmeier the spatial distributions of electromagnetic data and for decomposing those distributions into subparts. We

Coulson, Seana

306

ELVIS - ELectromagnetic Vector Information Sensor  

E-print Network

The ELVIS instrument was recently proposed by the authors for the Indian Chandrayaan-1 mission to the Moon and is presently under consideration by the Indian Space Research Organisation (ISRO). The scientific objective of ELVIS is to explore the electromagnetic environment of the moon. ELVIS samples the full three-dimensional (3D) electric field vector, E(x,t), up to 18 MHz, with selective Nyqvist frequency bandwidths down to 5 kHz, and one component of the magnetic field vector, B(x,t), from a few Hz up to 100 kHz.As a transient detector, ELVIS is capable of detecting pulses with a minimum pulse width of 5 ns. The instrument comprises three orthogonal electric dipole antennas, one magnetic search coil antenna and a four-channel digital sampling system, utilising flexible digital down conversion and filtering together with state-of-the-art onboard digital signal processing.

J. E. S. Bergman; L. hln; O. Stl; B. Thid; S. Ananthakrishnan; J. -E. Wahlund; R. L. Karlsson; W. Puccio; T. D. Carozzi; P. Kale

2005-09-29

307

Electromagnetic Induction with Neodymium Magnets  

NASA Astrophysics Data System (ADS)

In April 1820, Hans Christian rsted noticed that the needle of a nearby compass deflected briefly from magnetic north each time the electric current of the battery he was using for an unrelated experiment was turned on or off. Upon further investigation, he showed that an electric current flowing through a wire produces a magnetic field. In 1831 Michael Faraday and Joseph Henry separately expanded on rsted's discovery by showing that a changing magnetic field produces an electric current. Heinrich Lenz found in 1833 that an induced current has the opposite direction from the electromagnetic force that produced it. This paper describes an experiment that can help students to develop an understanding of Faraday's law and Lenz's law by studying the emf generated as a magnet drops through a set of coils having increasing numbers of turns.

Wood, Deborah; Sebranek, John

2013-09-01

308

Tracking Electromagnetic Energy With SQUIDs  

NASA Technical Reports Server (NTRS)

A superconducting quantum interference device (SQUID) is a gadget used to measure extremely weak signals, specifically magnetic flux. It can detect subtle changes in energy, up to 100 billion times weaker than the electromagnetic energy required to move a compass needle. SQUIDs are used for a variety of testing procedures where extreme sensitivity is required and where the test instrument need not come into direct contact with the test subject. NASA uses SQUIDs for remote, noncontact sensing in a variety of venues, including monitoring the Earth s magnetic field and tracking brain activity of pilots. Scientists at NASA s Goddard Space Flight Center have been making extensive use of this technology, from astrophysical research, to tracking the navigational paths of bees in flight to determine if they are using internal compasses. These very sensitive measurement devices have a wide variety of uses within NASA and even more uses within the commercial realm.

2005-01-01

309

Electromagnetic modeling of plasmonic nanostructures  

NASA Astrophysics Data System (ADS)

In this thesis, plasmonic properties of metal nanostructures are investigated by electromagnetic simulations using the finite difference time domain (FDTD) method. Chapter 1 covers the background knowledge required to read this thesis. It talks about the fundamentals of the FDTD method, the physics of plasmonics and a brief description of photocatalysis. In chapter 2, we perform optimization of plasmonic nanoparticle geometries. An iterative optimization algorithm is used to determine the configuration of the nanoparticles that gives the maximum electric field intensity at the center of the cluster. We observe that the optimum configurations of these clusters have mirror symmetry about the axis of planewave propagation, but are otherwise non-symmetric and non-intuitive. The maximum field intensity is found to increase monotonically with the number nanoparticles in the cluster, producing intensities that are 2500 times larger than the incident electromagnetic field. In chapter 3, evaporated thin films are imaged with high resolution transmission electron microscopy (HRTEM), to reveal the structure of the semicontinuous metal island film with sub-nm resolution. The electric field distributions and the absorption spectra of these semicontinuous island film geometries are calculated using the finite difference time domain (FDTD) method and compared with the experimentally measured absorption spectra. In addition to that, we calculate the SERS enhancement factors and photocatalytic enhancement factors of these films. We also study the effect of annealing on these films, which results in a large reduction in electric field strength due to increased nanoparticle spacing. In chapter 4, we study the effects of surrounding nanoparticles on a plasmonic hot spot. From our simulations, we show that the surrounding film contributes significantly to the electric field intensity at the hot spot by focusing energy to it. Widening of the gap size causes a decrease in the intensity at the hot spot. However, these island-like nanoparticle hot spots are shown to be robust to gap size than nanoparticle dimer geometries, studied previously. In fact, the main factor in determining the hot spot intensity is the focusing effect of the surrounding nano-islands. In chapter 5, we demonstrate plasmon-enhanced photocatalytic water splitting, and reduction of CO2 with H2O to form hydrocarbon fuels. Under visible illumination, we observe enhancements of up to 66X in the photocatalytic splitting of water in TiO2 with the addition of Au nanoparticles. We also perform a systematic study of the mechanisms of Au nanoparticle/TiO 2-catalyzed photoreduction of CO2 and water vapor over a wide range of wavelengths. In this case, under visible light illumination, we observe a 24-fold enhancement in the photocatalytic activity due to the intense local electromagnetic fields created by the surface plasmons of the Au nanoparticles. Above the plasmon resonance, under ultraviolet radiation we observe a reduction in the photocatalytic activity. Electromagnetic simulations indicate that the improvement of photocatalytic activity in the visible range is caused by the local electric field enhancement near the TiO2 surface, rather than by the direct transfer of charge between the two materials. In chapter 6, I will talk about a method for fabricating arrays of plasmonic nanoparticles with separations on the order of 1nm using an angle evaporation technique. High resolution transmission electron microscopy (HRTEM) is used to resolve the small separations achieved between nanoparticles fabricated on thin SiN membranes. These nearly touching metal nanoparticles produce extremely high electric field intensities when irradiated with laser light. We perform surface enhanced Raman spectroscopy (SERS) a non-resonant dye molecule (p-ATP) deposited on the nanoparticle arrays using confocal micro-Raman spectroscopy. Our results show significant enhancement when the incident laser is polarized parallel to the axis of the nanoparticle pairs, whereas no enhancement is observed for the p

Pavaskar, Prathamesh

310

Electromagnetic Signatures of SMBH Coalescence  

NASA Technical Reports Server (NTRS)

When two supermassive black holes (SMBHs) approach within 1-10 mpc, gravitational wave (GW) losses begin to dominate the evolution of the binary, pushing the system to merge in a relatively small time. During this final inspiral regime, the system will emit copious energy in GWs, which should be directly detectable by pulsar timing arrays and space-based interferometers. At the same time, any gas or stars in the immediate vicinity of the merging 5MBHs can get heated and produce bright electromagnetic (EM) counterparts to the GW signals. We present here a number of possible mechanisms by which simultaneous EM and GW signals will yield valuable new information about galaxy evolution, accretion disk dynamics, and fundamental physics in the most extreme gravitational fields.

Schnittman, Jeremy

2012-01-01

311

Broadband cavity electromagnetically induced transparency  

SciTech Connect

Cavity electromagnetically induced transparency (EIT) is created in a three-level atomic system confined in a cavity and coupled to a free-space control laser and is manifested as a narrow transmission peak of a probe laser coupled into the cavity mode and tuned to the two-photon Raman resonance with the control laser. Cavity EIT can be observed with a control laser detuned from the atomic transition frequency in a range limited by the vacuum Rabi splitting of two cavity-atom normal modes. This leads to the broadband cavity EIT obtained in the coupled-cavity-atom system with a free-space, broadband control laser. We report an experimental observation of broadband cavity EIT in cold Rb atoms with a frequency-modulated control laser and discuss its application in multichannel and multifrequency light memory.

Wei Xiaogang [Department of Physics, Florida International University, Miami, Florida 33199 (United States); College of Physics, Jilin University, Changchun 130023 (China); Wang Yanhua [Department of Physics, Florida International University, Miami, Florida 33199 (United States); College of Physics and Electronics, Shanxi University, Taiyuan 030006 (China); Zhang Jiepeng [Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Physics Division P-23, Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Zhu Yifu [Department of Physics, Florida International University, Miami, Florida 33199 (United States)

2011-10-15

312

Electromagnetic-gravitational energy systems  

NASA Technical Reports Server (NTRS)

Two methods are considered to 'tap' the earth's rotational energy. This ancient 'collapsed gravitational energy' exceeds the earth-lunar binding energy. One involves an orbiting 'electromagnetic-gravitational' coupling system whereby the earth's rotation, with its nonuniform mass distribution, first uses gravity to add orbital energy to a satellite, similar to a planetary 'flyby'. The second stage involves enhanced satellite 'drag' as current-carrying coils withdraw the added orbital energy as they pass through the earth's nonuniform magnetic field. A second more direct method couples the earth's rotational motion using conducting wires moving through the noncorotating part (ionospheric current systems) of the geomagnetic field. These methods, although not immediately feasible, are considerably more efficient than using pure gravitational coupling to earth-moon tides.

Schatten, K. H.

1981-01-01

313

Electromagnetic Decay of Molecular States  

E-print Network

Electromagnetic transitions from deformed structures based on $\\alpha$ configurations or on heavier clusters are discussed, drawing the link between multiparticle-multihole excited bands and cluster structures. Enhanced E2 and E1 transitions are reviewed in the light nuclei, $^8$Be, $^{10}$Be, $^{12}$C, $^{16}$O, $^{18}$O and heavier ones like $^{212}$Po. Connections between cluster structures and superdeformed configurations in $^{36}$Ar and $^{40}$Ca are discussed. What the cluster states based on heavier substructures like $^{12}$C and $^{16}$O are concerned, recent results on the resonant radiative capture reaction $^{12}$C($^{16}$O,$\\gamma$)$^{28}$Si are presented, in particular the strong decay mode involving the feeding of low-lying $^{28}$Si 1$^+$ and 2$^+$ T=1 states by enhanced M1 isovector transitions.

S. Courtin; A. Goasduff; F. Haas

2013-03-18

314

Advanced studies of electromagnetic scattering  

NASA Technical Reports Server (NTRS)

In radar signature applications it is often desirable to generate the range profiles and inverse synthetic aperture radar (ISAR) images of a target. They can be used either as identification tools to distinguish and classify the target from a collection of possible targets, or as diagnostic/design tools to pinpoint the key scattering centers on the target. The simulation of synthetic range profiles and ISAR images is usually a time intensive task and computation time is of prime importance. Our research has been focused on the development of fast simulation algorithms for range profiles and ISAR images using the shooting and bouncing ray (SBR) method, a high frequency electromagnetic simulation technique for predicting the radar returns from realistic aerospace vehicles and the scattering by complex media.

Ling, Hao

1994-01-01

315

Electromagnetic launchers for space applications  

NASA Technical Reports Server (NTRS)

An electromagnetic launcher (EML) was designed for NASA-Langley to boost large models to hypervelocity for flight evaluation. Two different concepts were developed using railgun and coilgun principles. A coilgun was designed to accelerate a 14-kg mass to 6 km/s and, by adding additional equipment, to accelerate a 10-kg mass to 11 km/s. The railgun system was designed to accelerate only 14 kg to 6 km/s. Of significance in this development is the opportunity to use the launcher for aeroballistic research of the upper atmosphere, eventually placing packages in low earth orbit using a small rocket. The authors describe the railgun and coilgun launch designs and suggest a reconfiguration for placement of 150-kg parcels into low earth orbit for aeroballistic studies and possible space lab support. Each design is detailed along with the performance adjustments which would be required for circular orbit payload placement.

Schroeder, J. M.; Gully, J. H.; Driga, M. D.

1989-01-01

316

An electromagnetic black hole made of metamaterials  

E-print Network

Traditionally, a black hole is a region of space with huge gravitational field, which absorbs everything hitting it. In history, the black hole was first discussed by Laplace under the Newton mechanics, whose event horizon radius is the same as the Schwarzschild's solution of the Einstein's vacuum field equations. If all those objects having such an event horizon radius but different gravitational fields are called as black holes, then one can simulate certain properties of the black holes using electromagnetic fields and metamaterials due to the similar propagation behaviours of electromagnetic waves in curved space and in inhomogeneous metamaterials. In a recent theoretical work by Narimanov and Kildishev, an optical black hole has been proposed based on metamaterials, in which the theoretical analysis and numerical simulations showed that all electromagnetic waves hitting it are trapped and absorbed. Here we report the first experimental demonstration of such an electromagnetic black hole in the microwave frequencies. The proposed black hole is composed of non-resonant and resonant metamaterial structures, which can trap and absorb electromagnetic waves coming from all directions spirally inwards without any reflections due to the local control of electromagnetic fields and the event horizon corresponding to the device boundary. It is shown that the absorption rate can reach 99% in the microwave frequencies. We expect that the electromagnetic black hole could be used as the thermal emitting source and to harvest the solar light.

Qiang Cheng; Tie Jun Cui; Wei Xiang Jiang; Ben Geng Cai

2010-04-30

317

An AWE Implementation for Electromagnetic Analysis  

NASA Technical Reports Server (NTRS)

Although full wave electromagnetic systems are large and cumbersome to solve, typically only a few parameters, such as input impedance, S parameters, and far field pattern, are needed by the designer or analyst. A reduced order modeling of these parameters is therefore an important consideration in minimizing the the CPU requirements. The Asymptotic Waveform Evaluation (AWE) method is one approach to construct a reduced order model of the input impedance or other useful electromagnetic parameters. We demonstrate its application and validity when used in conjunction with the finite element method to simulate full wave electromagnetic problems.

Gong, Jian; Volakis, John L.

1996-01-01

318

On the Axioms of Topological Electromagnetism  

E-print Network

The axioms of topological electromagnetism are refined by the introduction of the de Rham homology of k-vector fields on orientable manifolds and the use of Poincare duality in place of Hodge duality. The central problem of defining the electromagnetic constitutive law is elaborated upon in the linear and nonlinear cases. The manner by which the spacetime metric might follow from the constitutive law is examined in the linear case. The possibility that the intersection form of the spacetime manifold might play a role in defining a topological basis for the constitutive law is explored. The manner by which wave motion might follow from the electromagnetic structure is also discussed.

D. H. Delphenich

2003-11-26

319

Spinors and pre-metric electromagnetism  

E-print Network

The basic concepts of the formulation of Maxwellian electromagnetism in the absence of a Minkowski scalar product on spacetime are summarized, with particular emphasis on the way that the electromagnetic constitutive law on the space of bivectors over spacetime supplants the role of the Minkowski scalar product on spacetime itself. The complex geometry of the space of bivectors is summarized, with the intent of showing how an isomorphic copy of the Lorentz group appears in that context. The use of complex 3-spinors to represent electromagnetic fields is then discussed, as well as the expansion of scope that the more general complex projective geometry of the space of bivectors suggests.

David Delphenich

2005-12-22

320

Mechanics background influences students' conceptions in electromagnetism  

NSDL National Science Digital Library

The understanding of different aspects of the 'field' concept in electromagnetism was tested with high school students and prospective teachers of technological disciplines. Some of the observed difficulties could be interpreted as originating from the change in methodological approaches employed in different domains of physics: electromagnetism vis-a-vis mechanics. This may have encouraged students to misinterpret the nature of force interactions and work-energy conversions in the presence of electromagnetic fields. Clarification of the rationale for introducing the 'field' concept, especially in its historical aspect, could be useful in coping with the teaching-learning problems evidenced in this study and other research.

Galili, Igal

2006-05-08

321

Scattering by an electromagnetic radiation field  

E-print Network

Motion of test particles in the gravitational field associated with an electromagnetic plane wave is investigated. The interaction with the radiation field is modeled by a force term {\\it \\`a la} Poynting-Robertson entering the equations of motion given by the 4-momentum density of radiation observed in the particle's rest frame with a multiplicative constant factor expressing the strength of the interaction itself. Explicit analytical solutions are obtained. Scattering of fields by the electromagnetic wave, i.e., scalar (spin 0), massless spin $\\frac12$ and electromagnetic (spin 1) fields, is studied too.

Donato Bini; Andrea Geralico

2014-08-21

322

Modeling Electromagnetic Scattering From Complex Inhomogeneous Objects  

NASA Technical Reports Server (NTRS)

This software innovation is designed to develop a mathematical formulation to estimate the electromagnetic scattering characteristics of complex, inhomogeneous objects using the finite-element-method (FEM) and method-of-moments (MoM) concepts, as well as to develop a FORTRAN code called FEMOM3DS (Finite Element Method and Method of Moments for 3-Dimensional Scattering), which will implement the steps that are described in the mathematical formulation. Very complex objects can be easily modeled, and the operator of the code is not required to know the details of electromagnetic theory to study electromagnetic scattering.

Deshpande, Manohar; Reddy, C. J.

2011-01-01

323

Development of the strong electromagnet wiggler  

SciTech Connect

The Strong Electromagnet (SEM) wiggler is a permanent magnet-assisted electromagnet under development at the Lawrence Livermore National Laboratory (LLNL) as part of the Induction Linac Free-Electron-Laser (IFEL) program. This concept uses permanent magnets within the wiggler to provide a reverse bias flux in the iron and thus delay the onset of magnetic saturation. The electromagnet coils determine th4e wiggler field and operate at low current densities by virtue of their placement away from the midplane. The authors describe the design approach used and test data from a 7-period wiggler prototype that includes curved pole tips to provide wiggler-plane focusing.

Burns, M.J.; Deis, G.A.; Holmes, R.H.; Van Maren, R.D.; Halbach, K.

1988-03-01

324

Electromagnetic Properties for Arbitrary Spin Particles: Part 1 $-$ Electromagnetic Current and Multipole Decomposition  

E-print Network

In a set of two papers, we propose to study an old-standing problem, namely the electromagnetic interaction for particles of arbitrary spin. Based on the assumption that light-cone helicity at tree level and $Q^2=0$ should be conserved non-trivially by the electromagnetic interaction, we are able to derive \\emph{all} the natural electromagnetic moments for a pointlike particle of \\emph{any} spin. In this first paper, we propose a transparent decomposition of the electromagnetic current in terms of covariant vertex functions. We also define in a general way the electromagnetic multipole form factors, and show their relation with the electromagnetic moments. Finally, by considering the Breit frame, we relate the covariant vertex functions to multipole form factors.

Cdric Lorc

2009-01-27

325

Electromagnetic field radiation model for lightning strokes to tall structures  

Microsoft Academic Search

This paper describes observation and analysis of electromagnetic field radiation from lightning strokes to tall structures. Electromagnetic field waveforms and current waveforms of lightning strokes to the CN Tower have been simultaneously measured since 1991. A new calculation model of electromagnetic field radiation is proposed. The proposed model consists of the lightning current propagation and distribution model and the electromagnetic

H. Motoyama; W. Janischewskyj; A. M. Hussein; W. A. Chisholm; J. S. Chang; R. Rusan

1996-01-01

326

CONTROL ORIENTATED SYNTHESIS OF ELECTROMAGNETIC SHUNT IMPEDANCES FOR  

E-print Network

an electromagnetic transducer is used as an actuator. Electromagnetic transducers can be used as sensorsCONTROL ORIENTATED SYNTHESIS OF ELECTROMAGNETIC SHUNT IMPEDANCES FOR VIBRATION ISOLATION 1 S an electromagnetic transducer to develop the required control forces. In this paper, the technique of sensor

Fleming, Andrew J.

327

Title: Inverse Electromagnetic Problems Name: Gunther Uhlmann, Ting Zhou  

E-print Network

Title: Inverse Electromagnetic Problems Name: Gunther Uhlmann, Ting Zhou Affil./Addr. 1: University/University of California Irvine/tzhouuw@gmail.com Inverse Electromagnetic Problems Introduction In this chapter we consider inverse boundary problems for electromagnetic waves. The goal is to determine the electromagnetic

Uhlmann, Gunther

328

PHYS 4500, Winter 2014 1 Electromagnetic Fields II  

E-print Network

PHYS 4500, Winter 2014 1 PHYS 4500 Electromagnetic Fields II 1. What is this course all about's theorem, reflection and transmission of electromagnetic waves, cavity resonators, wave guides. Electromagnetic Radiation: dipoles, antennas, quantum mechanics and electro-magnetic interactions. 2. Textbook

Quirion, Guy

329

Quantitative interpretation of geophysical electromagnetic data for groundwater investigations  

E-print Network

of the subsurface. Electromagnetic induction. Sensitivity of airborne EM measurements. Interpretation ­ apparent of the subsurface. Electromagnetic induction. Sensitivity of airborne EM measurements. Interpretation ­ apparent orders of magnitude. #12;Electromagnetic induction I(t) sin t b #12;Electromagnetic induction Primary H

Farquharson, Colin G.

330

The Eyjafjallajkull volcanic system, Iceland: insights from electromagnetic measurements  

E-print Network

and ELECTROMAGNETISM, Geomagnetic induction ELECTROMAGNETISM, Remote sensing of volcanoesThe Eyjafjallajökull volcanic system, Iceland: insights from electromagnetic measurements Journal system, Iceland: insights from1 electromagnetic measurements2 Marion P. Miensopust1,2, , Alan G. Jones1

Jones, Alan G.

331

ECE 1228 Electromagnetics Theory Instructor Name: Mo Mojahedi  

E-print Network

ECE 1228 Electromagnetics Theory Instructor Name: Mo Mojahedi Office Location: Room SF2001D Tel: 416-978-0908 Email: mojahedi@waves.utoronto.ca Course Name and number: Electromagnetics Theory, ECE in Electromagnetics and Photonics. It revisits and expands some of the more fundamental electromagnetic laws

Mojahedi, Mohammad

332

Scalability of the Channel Capacity of Electromagnetic NanonetworksScalability of the Channel Capacity of Electromagnetic NanonetworksScalability of the Channel Capacity of Electromagnetic NanonetworksScalability of the Channel Capacity of Electromagnetic  

E-print Network

Scalability of the Channel Capacity of Electromagnetic NanonetworksScalability of the Channel Capacity of Electromagnetic NanonetworksScalability of the Channel Capacity of Electromagnetic NanonetworksScalability of the Channel Capacity of Electromagnetic Nanonetworks I. Llatser, A. CabellosI. Llatser, A. Cabellos

Politècnica de Catalunya, Universitat

333

Electromagnetic radiation from beam-plasma instabilities  

NASA Technical Reports Server (NTRS)

The mechanism by which unstable electrostatic waves of an electron-beam plasma system are converted into observed electromagnetic waves is of great current interest in space plasma physics. Electromagnetic radiation arises from both natural beam-plasma systems, e.g., type III solar bursts and kilometric radiation, and from man-made electron beams injected from rockets and spacecraft. In the present investigation the diagnostic difficulties encountered in space plasmas are overcome by using a large laboratory plasma. A finite diameter (d approximately equal to 0.8 cm) electron beam is injected into a uniform quiescent magnetized afterglow plasma of dimensions large compared with electromagnetic wavelength. Electrostatic waves grow, saturate and decay within the uniform central region of the plasma volume so that linear mode conversion on density gradients can be excluded as a possible generation mechanism for electromagnetic waves.

Stenzel, R. L.; Whelan, D. A.

1982-01-01

334

Method and apparatus for measuring electromagnetic radiation  

NASA Technical Reports Server (NTRS)

An apparatus and method are described in which the capacitance of a semiconductor junction subjected to an electromagnetic radiation field is utilized to indicate the intensity or strength of the radiation.

Been, J. F. (inventor)

1973-01-01

335

Tour of the Electromagnetic Spectrum Book  

NSDL National Science Digital Library

This booklet introduces electromagnetic waves, their behaviors, and how scientists visualize these data. Each region of the spectrum is described and illustrated with examples of NASA science. It is a companion piece to the video series under the same title.

336

Cartan's Supersymmetry and Weak and Electromagnetic Interactions  

E-print Network

We apply the Cartan's supersymmetric model to the weak interaction of hadrons. The electromagnetic currents are transformed by $G_{12},G_{123},G_{13},G_{132}$ and the factor$(1-\\gamma_5)$ is inserted between $l \\bar\

Furui, Sadataka

2015-01-01

337

Cartan's Supersymmetry and Weak and Electromagnetic Interactions  

E-print Network

We apply the Cartan's supersymmetric model to the weak interaction of hadrons. The electromagnetic currents are transformed by $G_{12},G_{123},G_{13},G_{132}$ and the factor$(1-\\gamma_5)$ is inserted between $l \\bar\

Sadataka Furui

2015-02-16

338

Electrical wire insulation and electromagnetic coil  

DOEpatents

An electromagnetic coil for high temperature and high radiation application in which glass is used to insulate the electrical wire. A process for applying the insulation to the wire is disclosed which results in improved insulation properties.

Bich, George J. (Penn Hills, PA); Gupta, Tapan K. (Monroeville, PA)

1984-01-01

339

Avionics electromagnetic interference immunity and environment  

NASA Technical Reports Server (NTRS)

Aircraft electromagnetic spectrum and radio frequency (RF) field strengths are charted, profiling the higher levels of electromagnetic voltages encountered by the commercial aircraft wiring. Selected military, urban, and rural electromagnetic field levels are plotted and provide a comparison of radiation amplitudes. Low frequency magnetic fields and electric fields from 400 H(Z) power systems are charted versus frequency and wire separation to indicate induced voltages on adjacent or neighboring circuits. Induced EMI levels and attenuation characteristics of electric, magnetic, RF fields, and transients are plotted and graphed for common types of wire circuits. The significance of wire circuit returns and shielding is emphasized to highlight the techniques that help block the paths of electromagnetic interference and maintain avionic interface signal quality.

Clarke, C. A.

1986-01-01

340

Electromagnetic Fields and Public Health: Mobile Phones  

MedlinePLUS

... sheets Features Commentaries Multimedia Contacts Electromagnetic fields and public health: mobile phones Fact sheet N193 Reviewed October ... important to investigate, understand and monitor any potential public health impact. Mobile phones communicate by transmitting radio waves ...

341

Scaling law describes Earth's electromagnetic environment  

NASA Astrophysics Data System (ADS)

The electromagnetic environment surrounding Earth, including the geomagnetic field and atmospheric electric fields, varies on all time scales, but this frequency dependence has not been well studied. Analyzing observations compiled from several published sources, Fllekrug and Fraser-Smith found that the energy density of the electromagnetic fields at the surface of the Earth follows a simple, fundamental scaling law: The energy density of the fields at a given frequency is inversely proportional to the square of the frequency. This relationship extends over a wide range of frequencies16 orders of magnitude. The authors note that this is somewhat surprising, given the many different processes that cause electromagnetic field variations, including lightning discharge in the atmosphere, geomagnetic storms in the ionosphere, and many other electromagnetic effects, such as sprites in the middle atmosphere.

Balcerak, Ernie

2012-01-01

342

Advances in non-planar electromagnetic prototyping  

E-print Network

The advent of metamaterials has introduced new ways to manipulate how electromagnetic waves reflect, refract and radiate in systems where the range of available material properties now includes negative permittivity, ...

Ehrenberg, Isaac M

2013-01-01

343

Advanced high-temperature electromagnetic pump  

NASA Technical Reports Server (NTRS)

Three phase helical, electromagnetic induction pump for use as boiler feed pump in potassium Rankine-cycle power system is described. Techniques for fabricating components of pump are discussed. Specifications of pump are analyzed.

Gahan, J. W.; Powell, A. H.

1972-01-01

344

Tabletop Models for Electrical and Electromagnetic Geophysics.  

ERIC Educational Resources Information Center

Details the use of tabletop models that demonstrate concepts in direct current electrical resistivity, self-potential, and electromagnetic geophysical models. Explains how data profiles of the models are obtained. (DDR)

Young, Charles T.

2002-01-01

345

Calculation of electromagnetic force in electromagnetic forming process of metal sheet  

SciTech Connect

Electromagnetic forming (EMF) is a forming process that relies on the inductive electromagnetic force to deform metallic workpiece at high speed. Calculation of the electromagnetic force is essential to understand the EMF process. However, accurate calculation requires complex numerical solution, in which the coupling between the electromagnetic process and the deformation of workpiece needs be considered. In this paper, an appropriate formula has been developed to calculate the electromagnetic force in metal work-piece in the sheet EMF process. The effects of the geometric size of coil, the material properties, and the parameters of discharge circuit on electromagnetic force are taken into consideration. Through the formula, the electromagnetic force at different time and in different positions of the workpiece can be predicted. The calculated electromagnetic force and magnetic field are in good agreement with the numerical and experimental results. The accurate prediction of the electromagnetic force provides an insight into the physical process of the EMF and a powerful tool to design optimum EMF systems.

Xu Da; Liu Xuesong; Fang Kun; Fang Hongyuan [State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001 (China)

2010-06-15

346

Geometric phases in multidirectional electromagnetic coupling theory  

NASA Astrophysics Data System (ADS)

Geometric phases are determined for N coupled electromagnetic wave amplitudes evolving in their projective Hilbert space. Multidirectional coupling systems subject to SU ( N) dynamical symmetry are proposed and Aharonov-Anandan phases are evaluated in a spinorial representation, for both closed and partial circuits described by the SU(2) group. Following closely Bhandari's idea, this kind of systems enlarges the general framework of topological phases for electromagnetic waves.

L?nares, J.; Nistal, M. C.

1992-01-01

347

Apparatus and Methods for Mitigating Electromagnetic Emissions  

NASA Technical Reports Server (NTRS)

Apparatus, methods, and other embodiments associated with mitigation of magnetic fields are described herein. In an embodiment, a method for mitigating an electromagnetic field includes positioning a mitigating coil around a linear alternator of linear motor so that the mitigating coil is coaxially located with an alternator coil; arranging the mitigating coil to generate a field to mitigate an electromagnetic field generated by the alternator coil; and passing an induced current from the alternator coil through the mitigating coil.

Geng, Steven M. (Inventor); Niedra, Janis M. (Inventor)

2013-01-01

348

Protecting the Power Grid From Electromagnetic Pulses  

NASA Astrophysics Data System (ADS)

A nuclear explosion high in the Earth's atmosphere does no immediate known harm to living things, but the resulting electromagnetic pulse (EMP) from a single detonation could degrade 70 percent or more of the country's electrical service in an instant, warns the Commission to Assess the Threat to the United States from Electromagnetic Pulse Attack, which presented its findings to the U.S. Congress in July.

Simpson, Sarah

2004-10-01

349

Control of Flow Separation Using Electromagnetic Forces  

Microsoft Academic Search

If a fluid is electrically conductive, its flow may be controlled using electromagnetic forces. Meanwhile, this technique\\u000a is a recognized tool even on an industrial scale for handling highly conductive materials like liquid metals. However, also\\u000a fluids of low electrical conductivity as considered in the present study, like sea-water and other electrolytes, permit electromagnetic\\u000a flow control. Experimental results on the

Tom Weier; Gunther Gerbeth; Gerd Mutschke; Olgerts Lielausis; Gerd Lammers

2003-01-01

350

Generating highly uniform electromagnetic field characteristics  

DOEpatents

An apparatus and method for generating homogeneous electromagnetic fields within a volume is disclosed. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set. 39 figs.

Crow, J.T.

1998-02-10

351

Generating highly uniform electromagnetic field characteristics  

DOEpatents

An apparatus and method for generating homogenous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set.

Crow, James Terry (Albuquerque, NM)

1998-01-01

352

Generating highly uniform electromagnetic field characteristics  

DOEpatents

An apparatus and method for generating homogenous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially cancelling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set.

Crow, James T. (Albuquerque, NM)

1997-01-01

353

Generating highly uniform electromagnetic field characteristics  

DOEpatents

An apparatus and method are disclosed for generating homogeneous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented mirror symmetrically about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set. 26 figs.

Crow, J.T.

1997-06-24

354

Generating highly uniform electromagnetic field characteristics  

DOEpatents

An apparatus and method for generating homogenous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set.

Crow, James T. (Albuquerque, NM)

1998-01-01

355

Generating highly uniform electromagnetic field characteristics  

DOEpatents

An apparatus and method are disclosed for generating homogeneous electromagnetic fields within a volume. The homogeneity provided may be for magnetic and/or electric fields, and for field magnitude, radial gradient, or higher order radial derivative. The invention comprises conductive pathways oriented about a desired region of homogeneity. A corresponding apparatus and method is provided for substantially canceling the electromagnetic field outside of the apparatus, comprising a second set of conductive pathways placed outside the first set. 55 figs.

Crow, J.T.

1998-05-05

356

Hybrid genetic algorithm for electromagnetic topology optimization  

Microsoft Academic Search

This paper proposes a hybrid genetic algorithm (GA) for electromagnetic topology optimization. A two-dimensional (2-D) encoding technique, which considers the geometrical topology, is first applied to electromagnetics. Then, a 2-D geographic crossover is used as the crossover operator. A novel local optimization algorithm, called the on\\/off sensitivity method, hybridized with the 2-D encoded GA, improves the convergence characteristics. The algorithm

Chang-Hwan Im; Hyun-Kyo Jung; Yong-Joo Kim

2003-01-01

357

Characterization of electromagnetic transients in power substations  

E-print Network

of the Electrical Environment in High Voltage Substations Project Background The TRUCC System Characterization of Electromagnetic Transients in Power Substations. II. SAMPLED DATA SYSTEMS Page V111 12 13 The Acquisition Model Sampled Continuous...CHARACTERIZATION OF ELECTROMAGNETIC TRANSIENTS IN POWER SUBSTATIONS A Thesis by WILLIAM CHESTER CiOERS, JR. Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER...

Goers, William Chester

2012-06-07

358

Electromagnetic and spin polarisabilities in lattice QCD  

E-print Network

We discuss the extraction of the electromagnetic and spin polarisabilities of nucleons from lattice QCD. We show that the external field method can be used to measure all the electromagnetic and spin polarisabilities including those of charged particles. We then turn to the extrapolations required to connect such calculations to experiment in the context of chiral perturbation theory, finding a strong dependence on the lattice volume and quark masses.

W. Detmold; B. C. Tiburzi; A. Walker-Loud

2006-10-02

359

Electromagnetic Corrections in Staggered Chiral Perturbation Theory  

E-print Network

To reduce errors in light-quark mass determinations, it is now necessary to consider electromagnetic contributions to light-meson masses. Calculations using staggered quarks and quenched photons are currently underway. Suitably-extended chiral perturbation theory is necessary to extrapolate the lattice data to the physical limit. Here we give (preliminary) results for light-meson masses using staggered chiral perturbation theory including electromagnetism, and discuss the extent to which quenched-photon simulations can improve quark-mass calculations.

C. Bernard; E. D. Freeland

2010-11-17

360

How living systems recognize applied electromagnetic fields  

Microsoft Academic Search

Natural and man-made magnetic and electromagnetic fields are important factors in the contemporary life. The paper discusses\\u000a the role of environmental magnetic and electromagnetic fields in origin and evolution of life. A brief review of the characteristics\\u000a of Earth magnetic field, Earth magnetosphere, and their role as a shield for cosmic radiation follows. The role of endogenous\\u000a and exogenous magnetic

Marko S. Markov

2011-01-01

361

Quantum computing algorithm for electromagnetic field simulation  

Microsoft Academic Search

Quantum computing offers new concepts for the simulation of complex physical systems. A quantum computing algorithm for electromagnetic\\u000a field simulation is presented here. The electromagnetic field simulation is performed on the basis of the Transmission Line\\u000a Matrix (TLM) method. The Hilbert space formulation of TLM allows us to obtain a time evolution operator for the TLM method,\\u000a which can then

Siddhartha Sinha; Peter Russer

2010-01-01

362

Electromagnetic probes of the QGP  

E-print Network

We investigate the properties of the QCD matter across the deconfinement phase transition in the scope of the parton-hadron string dynamics (PHSD) transport approach. We present here in particular the results on the electromagnetic radiation, i.e. photon and dilepton production, in relativistic heavy-ion collisions. By comparing our calculations for the heavy-ion collisions to the available data, we determine the relative importance of the various production sources and address the possible origin of the observed strong elliptic flow $v_2$ of direct photons. We argue that the different centrality dependence of the hadronic and partonic sources for direct photon production in nucleus-nucleus collisions can be employed to shed some more light on the origin of the photon $v_2$ "puzzle". While the dilepton spectra at low invariant mass show in-medium effects like an enhancement from multiple baryonic resonance formation or a collisional broadening of the vector meson spectral functions, the dilepton yield at high...

Bratkovskaya, E L; Cassing, W

2014-01-01

363

Parallel computation of electromagnetic fields  

SciTech Connect

The DSI3D code is designed to numerically solve electromagnetics problems involving complex objects by solving Maxwell`s curl equations in the time-domain and in three space dimensions. The code has been designed to run on the new parallel processing computers as well as on conventional serial computers. The DSI3D code is unique for the following reasons: It runs efficiently on a variety of parallel computers, Allows the use of unstructured non-orthogonal grids, Allows a variety of cell or element types, Reduces to be the Finite Difference Time Domain (FDID) method when orthogonal grids are used, Preserves charge or divergence locally (and globally), Is non- dissipative, and Is accurate for non-orthogonal grids. This method is derived using a Discrete Surface Integration (DSI) technique. As formulated, the DSI technique can be used with essentially arbitrary unstructured grids composed of convex polyhedral cells. This implementation of the DSI algorithm allows the use of unstructured grids that are composed of combinations of non-orthogonal hexahedrons, tetrahedrons, triangular prisms and pyramids. This algorithm reduces to the conventional FDTD method when applied on a structured orthogonal hexahedral grid.

Madsen, N.K.

1997-05-21

364

Aircraft Lightning Electromagnetic Environment Measurement  

NASA Technical Reports Server (NTRS)

This paper outlines a NASA project plan for demonstrating a prototype lightning strike measurement system that is suitable for installation onto research aircraft that already operate in thunderstorms. This work builds upon past data from the NASA F106, FAA CV-580, and Transall C-180 flight projects, SAE ARP5412, and the European ILDAS Program. The primary focus is to capture airframe current waveforms during attachment, but may also consider pre and post-attachment current, electric field, and radiated field phenomena. New sensor technologies are being developed for this system, including a fiber-optic Faraday polarization sensor that measures lightning current waveforms from DC to over several Megahertz, and has dynamic range covering hundreds-of-volts to tens-of-thousands-of-volts. A study of the electromagnetic emission spectrum of lightning (including radio wave, microwave, optical, X-Rays and Gamma-Rays), and a compilation of aircraft transfer-function data (including composite aircraft) are included, to aid in the development of other new lightning environment sensors, their placement on-board research aircraft, and triggering of the onboard instrumentation system. The instrumentation system will leverage recent advances in high-speed, high dynamic range, deep memory data acquisition equipment, and fiber-optic interconnect.

Ely, Jay J.; Nguyen, Truong X.; Szatkowski, George N.

2011-01-01

365

Nde: Surfing the Electromagnetic Spectrum  

NASA Astrophysics Data System (ADS)

Advances in Nondestructive Evaluation demand an arsenal of techniques. This was as true twenty years ago as it is today. As materials and their associated technologies progress, so must the strategy for evaluating the quality of the product. Nondestructive Evaluation is a constant struggle to extract, from classical and quantum physics, the quintessential elements that will optimally address an inspection requirement, apart from purely academic interest. It must work to be useful and thereby advance the field. The electromagnetic spectrum, from Roentgen to Maxwell/Hertz, lies at the foundation of both classical and quantum physics. Not only has NDE plucked pearls form every nook of the spectrum ranging from X-rays to T-rays but also has managed to utilize virtually every known coupling of the spectrum to the classical mechanics of heat and sound. I will "surf" the spectrum to provide a sampling of what NDE has extracted past and present as well as try to couple to its future.

Ringermacher, Harry I.

2010-02-01

366

Octonionic matrix representation and electromagnetism  

NASA Astrophysics Data System (ADS)

Keeping in mind the important role of octonion algebra, we have obtained the electromagnetic field equations of dyons with an octonionic 88 matrix representation. In this paper, we consider the eight dimensional octonionic space as a combination of two (external and internal) four-dimensional spaces for the existence of magnetic monopoles (dyons) in a higher-dimensional formalism. As such, we describe the octonion wave equations in terms of eight components from the 8 8 matrix representation. The octonion forms of the generalized potential, fields and current source of dyons in terms of 8 8 matrix are discussed in a consistent manner. Thus, we have obtained the generalized Dirac-Maxwell equations of dyons from an 88 matrix representation of the octonion wave equations in a compact and consistent manner. The generalized Dirac-Maxwell equations are fully symmetric Maxwell equations and allow for the possibility of magnetic charges and currents, analogous to electric charges and currents. Accordingly, we have obtained the octonionic Dirac wave equations in an external field from the matrix representation of the octonion-valued potentials of dyons.

Chanyal, B. C.

2014-12-01

367

Elec Eng 2FH3 Electromagnetics I COURSE NUMBER & TITLE: Elec Eng 2FH3 Electromagnetics I  

E-print Network

Elec Eng 2FH3 ­ Electromagnetics I COURSE NUMBER & TITLE: Elec Eng 2FH3 ­ Electromagnetics I field 6. Inductance 7. Faraday's law CALENDAR DESCRIPTION: Electromagnetics Part I is an introduction into engineering electromagnetics. It covers the mathematical foundations such as selected topics of vector

Haykin, Simon

368

Large Dynamic Range Electromagnetic FieldLarge Dynamic Range Electromagnetic Field Sensor based on Domain Inverted Electro-Optic  

E-print Network

Large Dynamic Range Electromagnetic FieldLarge Dynamic Range Electromagnetic Field Sensor based Sensors:Application of Electric Field Sensors: Electromagnetic Attack AlarmingElectromagnetic Attack simulation work · Full spectrum coverage n n n dV Vfd n h )( ! 1 = are the Taylor coefficients · Full

Texas at Austin, University of

369

High-frequency seismo-electromagnetic effects  

NASA Astrophysics Data System (ADS)

Electromagnetic perturbations caused by natural geophysical activity, such as earthquakes and volcanic eruptions, have been studied since the great Alaskan earthquake in 1964. In recent years, interest has been increasing because, when a precursor event occurs, it normally does so less than a few hours before the shock. This paper presents a review of the high-frequency seismo-electromagnetic phenomena already observed, and occurring before, as well as after the shock. The term 'high frequency' is to be taken in the seismic sense, i.e. larger than a few Hertz. Mechanisms that might produce these seismo-electromagnetic emissions will be described. It is shown that, at the moment, a causal relationship between electromagnetic signals and seismic activity still remains to be demonstrated. Theoretical as well as intensive experimental studies are necessary to understand the physical processes responsible for seismo or volcano-electric variations, electrical resistivity variations, electromagnetic effects associated with dilatance, as well as electromagnetic fields generated during laboratory experiments, or ionospheric disturbances.

Parrot, M.; Achache, J.; Berthelier, J. J.; Blanc, E.; Deschamps, A.; Lefeuvre, F.; Menvielle, M.; Plantet, J. L.; Tarits, P.; Villain, J. P.

1993-04-01

370

Is Electromagnetic Gravity Control Possible?  

SciTech Connect

We study the interplay of Einstein's Gravitation (GR) and Maxwell's Electromagnetism, where the distribution of energy-momentum is not presently known (The Feynman Lectures, Vol 2, Chapter 27, section 4). As Feynman himself stated, one might in principle use Einstein's equations of GR to find such a distribution. GR (born in 1915) presently uses the Levi-Civita connection, LCC (the LCC was born two years after GR as a new concept, and not just as the pre-existing Christoffel symbols that represent it). Around 1927, Einstein proposed for physics an alternative to the LCC that constitutes a far more sensible and powerful affine enrichment of metric Riemannian geometry. It is called teleparallelism (TP). Its Finslerian version (i.e. in the space-time-velocity arena) permits an unequivocal identification of the EM field as a geometric quantity. This in turn permits one to identify a completely geometric set of Einstein equations from curvature equations. From their right hand side, one may obtain the actual distribution of EM energy-momentum. It is consistent with Maxwell's equations, since these also are implied by the equations of structure of TP. We find that the so-far-unknown terms in this distribution amount to a total differential and do not, therefore, alter the value of the total EM energy-momentum. And yet these extra terms are at macroscopic distances enormously larger than the standard quadratic terms. This allows for the generation of measurable gravitational fields by EM fields. We thus answer affirmatively the question of the title.

Vargas, Jose G. [PST Associates, 600 Westover Rd, Columbia, SC 29210 (United States); Torr, Douglas G. [PST Associates, 5221 Tern Place, Fayetteville, NC 28311-1967 (United States)

2004-02-04

371

Electromagnetic Properties of Binary Composites  

NASA Astrophysics Data System (ADS)

This dissertation contains theoretical studies of electromagnetic properties of three different binary granular composites: Dilute conductor-insulator mixtures with conducting fractal clusters in a long-wavelength limit; dense disordered mixtures of dielectrics in a short-wavelength limit; and optically anisotropic "photonic crystals"--periodic arrays of anisotropic dielectric scatterers--in several wavelength regimes. The key results of this dissertation are: (1) Numerical studies show that fractal clustering of metallic particles in metal-insulator granular composites can lead to the extremely large far-infrared absorptions observed experimentally but not predicted by classical effective-medium theories. Exact calculations for two -dimensional model composites show that both fractal clusters which are random in structure and which are deterministic in structure produce this effect at far-infrared frequencies. At higher frequencies deterministic fractals can give rise to a clear series of absorption resonances that is not evident in composites with random fractal clusters. Conducting fractal clusters are also used to represent the brine-saturated pore space of sedimentary rocks, and the low-frequency dielectric response of real rocks is reproduced. (2) Two simple models, one analytical and one numerical, are used to explain short wavelength optical transmission experiments through dense, disordered, fluid-saturated packings of dielectric grains. Calculations show that the transmitted light can serve as a probe of length scales and dielectric contrast within the composite. In addition, for a thin, weakly scattering sample, the light propagates ballistically rather than diffusively. (3) A novel way of manipulating photonic band gaps in ordered arrays of dielectric scatterers is introduced, involving scatterers with anisotropic dielectric functions. Photonic band structure calculations are carried out for diamond-structure arrays of spheres which are optically uniaxial and biaxial, Faraday-active, and naturally optically active. Anisotropy can lead to narrowing and closing of photonic gaps, converting photonic "insulators" into photonic "semimetals.".

Zabel, Ingrid Helena Hoffmann

372

Relativistic electromagnetic ion cyclotron instabilities.  

PubMed

The relativistic instabilities of electromagnetic ion cyclotron waves driven by MeV ions are analytically and numerically studied. As caused by wave magnetic field and in sharp contrast to the electrostatic case, interesting characteristics such as Alfve nic behavior and instability transition are discovered and illuminated in detail. The instabilities are reactive and are raised from the coupling of slow ions' first-order resonance and fast ions' second-order resonance, that is an essential extra mechanism due to relativistic effect. Because of the wave magnetic field, the nonresonant plasma dielectric is usually negative and large, that affects the instability conditions and scaling laws. A negative harmonic cyclotron frequency mismatch between the fast and slow ions is required for driving a cubic (and a coupled quadratic) instability; the cubic (square) root scaling of the peak growth rate makes the relativistic effect more important than classical mechanism, especially for low fast ion density and Lorentz factor being close to unity. For the cubic instability, there is a threshold (ceiling) on the slow ion temperature and density (the external magnetic field and the fast ion energy); the Alfve n velocity is required to be low. This Alfve nic behavior is interesting in physics and important for its applications. The case of fast protons in thermal deuterons is numerically studied and compared with the analytical results. When the slow ion temperature or density (the external magnetic field or the fast ion energy) is increased (reduced) to about twice (half) the threshold (ceiling), the same growth rate peak transits from the cubic instability to the coupled quadratic instability and a different cubic instability branch appears. The instability transition is an interesting new phenomenon for instability. PMID:15903591

Chen, K R; Huang, R D; Wang, J C; Chen, Y Y

2005-03-01

373

Progress In Electromagnetics Research, PIER 79, 387399, 2008 ELECTROMAGNETIC SCATTERING ANALYSIS USING  

E-print Network

Progress In Electromagnetics Research, PIER 79, 387­399, 2008 ELECTROMAGNETIC SCATTERING ANALYSIS is further expanded to the analysis of open space problems in the context of scattering from two-Daubechies- Feauveau family of wavelets [9], in particular the CDF (2,2) wavelet, which accommodates all the desired

Elsherbeni, Atef Z.

374

Electromagnetic compatibility management for fast diagnostic design  

NASA Astrophysics Data System (ADS)

This article presents an overview of electromagnetic compatibility (EMC) management for fast diagnostic design. We will present and detail the classical approach in EMC. This approach can be successfully applied for installations where a single engineering entity has the authority to prescribe and enforce a certain compatibility level. Most of the time, strict application of generic standards is required for fast diagnostics. Nethertheless, the pulse perturbation must be synchronized to the fast diagnostic operation. Some "traditional" techniques, such as star-earthing and bonding cable screens at one end, have been shown to be inadequate for fast diagnostic design. Our laser facility, the LIL, will be able to focus up to 60 kJ into a volume of less than 1 mm3. We have to evaluate the electromagnetic pulse (EMP) where diagnostics, cables, and oscilloscopes will be installed. We performed electromagnetic measurements inside and outside the OMEGA target chamber. The electromagnetic pulse generated by the target chamber contains very high frequency components above 1 GHz. The electric field is around a few kV/m outside and goes up to 20 kV/m inside the target. We designed a specific electromagnetic probe for pulse measurement with a rise time down to 100 ps. An ultrashort rise time EMP bench test was built to test apparatus before installation around a target chamber. It produces an electric field higher than 5 kV/m with a rise time under 100 ps.

Raimbourg, J.

2004-10-01

375

Power law inflation with electromagnetism  

SciTech Connect

We generalize Ringstrms global future causal stability results (Ringstrm 2009) [11] for certain expanding cosmological solutions of the Einstein-scalar field equations to solutions of the EinsteinMaxwell-scalar field system. In particular, after noting that the power law inflationary spacetimes (M{sup n+1},g{sup -hat}, ?{sup -hat}) considered by Ringstrm (2009) in [11] are solutions of the EinsteinMaxwell-scalar field system (with exponential potential) as well as of the Einstein-scalar field system (with the same exponential potential), we consider (nonlinear) perturbations of initial data sets of these spacetimes which include electromagnetic perturbations as well as gravitational and scalar perturbations. We show that if (as in Ringstrm (2009) [11]) we focus on pairs of relatively scaled open sets U{sub R{sub 0}}?U{sub 4R{sub 0}} on an initial slice of (M{sup n+1},g{sup -hat}), and if we choose a set of perturbed data which on U{sub 4R{sub 0}} is sufficiently close to that of (M{sup n+1},g{sup -hat},?{sup -hat}, A{sup -hat} = 0), then in the maximal globally hyperbolic spacetime development (M{sup n+1},g,?,A) of this data via the EinsteinMaxwell-scalar field equations, all causal geodesics emanating from U{sub R{sub 0}} are future complete (just as in (M{sup n+1},g{sup -hat})). We also verify that, in a certain sense, the future asymptotic behavior of the fields in the spacetime developments of the perturbed data sets does not differ significantly from the future asymptotic behavior of (M{sup n+1},g{sup -hat}, ?{sup -hat}, A{sup -hat} = 0). -- Highlights: We prove stability of expanding solutions of the EinsteinMaxwell-scalar field equations. All nearby solutions are geodesically complete. The topology of the initial slice is irrelevant to our stability results.

Luo, Xianghui; Isenberg, James, E-mail: isenberg@uoregon.edu

2013-07-15

376

Electromagnetics for Detecting Shallow Tunnels  

NASA Astrophysics Data System (ADS)

Detecting tunnels by geophysical means, even very shallow ones, has been difficult, to say the least. Despite heavy R&D funding from the military since the early 70s, geophysicists have not produced tools that are simple and practical enough to meet the military needs. The initial interest and R&D funding on the subject perhaps started with the Vietcong tunnels in the 60s. Tunnels in the Korean DMZ, first found in the mid 70s, sharply escalated the R&D spending. During the 90s, covert tunnels along the US-Mexico border have kept the topic alive but at a minimal funding level. Most recent interest appears to be in the terrorism-related shallow tunnels, more or less anywhere in the regions of conflict. Despite the longstanding effort in the geophysical community under heavy public funding, there is a dearth of success stories where geophysicists can actually claim to have found hitherto unknown tunnels. For instance, geophysics has not discovered a single tunnel in Vietnam or in Korea! All tunnels across the Korean DMZ were found from human intelligence. The same is true to all illicit tunnels found along the southwestern border. The tunnels under discussion are clandestine, which implies that the people who built them do not wish others to succeed in finding them. The place around the tunnel, therefore, may not be the friendliest venue for surveyors to linger around. The situation requires tools that are fast, little noticeable, and hardly intrusive. Many geophysical sensors that require ground contacts, such as geophones and electrodes that are connected by a myriad of cables, may not be ideal in this situation. On the other hand, a sensor that can be carried by vehicle without stopping, and is nothing obviously noticeable to bystanders, could be much more acceptable. Working at unfriendly environment also requires forgoing our usual practices where we collect data leisurely and make pretty maps later. To be useful, geophysical tools must be able to process observed data and translate them into actionable results. They may in forms of audio (similar to the beeper of a landmine detector), strip chart, or even a 2D graphic display on a computer screen. In short, the tool must be able to declare a contact, audibly or graphically, in real time or shortly thereafter. In summary, we have two questions here. The first one is if any of the available geophysical tools can detect tunnels. If the answer is yes, then the next question is if any of them are able to perform fast in an unfriendly environment. Electromagnetic sensors may be able to meet the operational requirements: under what circumstances it can find tunnels would be another outstanding question.

Won, I.

2006-05-01

377

Apparatus for processing electromagnetic radiation and method  

NASA Technical Reports Server (NTRS)

Measuring apparatus including a ruled member having alternate transparent and opaque zones. An optical coupler connecting the ruled member with electromagnetic radiation-conversion apparatus. The conversion apparatus may include a photomultiplier and a discriminator. Radiation impinging on the ruled member will, in part, be converted to electrical pulses which correspond to the intensity of the radiation. A method of processing electromagnetic radiation includes providing a member having alternating dark and light zones, establishing movement of the member through the beam of electromagnetic radiation with the dark zones interrupting passage of radiation through the rule, providing an optical coupler to connect a portion of the radiation with a conversion station where the radiation portion is converted into an electrical pulse which is related to the intensity of the radiation received at the conversion station. The electrical pulses may be counted and the digitized signals stored or permanently recorded to produce positional information.

Gatewood, George D. (Inventor)

1983-01-01

378

An Introduction to Classical Electromagnetic Radiation  

NASA Astrophysics Data System (ADS)

A fundamental and thorough description of classical electromagnetic radiation, this book is a balance of physical and mathematical explanation and includes over 300 illustrations. Starting from Maxwell's equations, the author demonstrates how fundamental concepts are applied in a wide variety of examples from areas such as classical optics, antenna analysis, and electromagnetic scattering. An interweaving of theoretical and experimental results gives insight into the physical and historical foundations of the subject. The book gives equal footing to the radiation of pulses and the more conventional time harmonic signals. With more than 140 problems, it can be used as a textbook for advanced undergraduate and graduate courses in electrical engineering and physics, and will also be of interest to scientists and engineers working in applied electromagnetics. A solutions manual is available for instructors.

Smith, Glenn S.

1997-08-01

379

Advanced electromagnetic methods for aerospace vehicles  

NASA Technical Reports Server (NTRS)

The Advanced Helicopter Electromagnetics (AHE) Industrial Associates Program continues its research on variety of main topics identified and recommended by the Advisory Task Force of the program. The research activities center on issues that advance technology related to helicopter electromagnetics. While most of the topics are a continuation of previous works, special effort has been focused on some of the areas due to recommendations from the last annual conference. The main topics addressed in this report are: composite materials, and antenna technology. The area of composite materials continues getting special attention in this period. The research has focused on: (1) measurements of the electrical properties of low-conductivity materials; (2) modeling of material discontinuity and their effects on the scattering patterns; (3) preliminary analysis on interaction of electromagnetic fields with multi-layered graphite fiberglass plates; and (4) finite difference time domain (FDTD) modeling of fields penetration through composite panels of a helicopter.

Balanis, Constantine A.; Sun, Weimin; El-Sharawy, El-Budawy; Aberle, James T.; Birtcher, Craig R.; Peng, Jian; Tirkas, Panayiotis A.

1992-01-01

380

Electromagnetic energy momentum in dispersive media  

SciTech Connect

The standard derivations of electromagnetic energy and momentum in media take Maxwell's equations as the starting point. It is well known that for dispersive media this approach does not directly yield exact expressions for the energy and momentum densities. Although Maxwell's equations fully describe electromagnetic fields, the general approach to conserved quantities in field theory is not based on the field equations, but rather on the action. Here an action principle for macroscopic electromagnetism in dispersive, lossless media is used to derive the exact conserved energy-momentum tensor. The time-averaged energy density reduces to Brillouin's simple formula when the fields are monochromatic. The time-averaged momentum density for monochromatic fields corresponds to the familiar Minkowski expression DxB, but for general fields in dispersive media the momentum density does not have the Minkowski value. The results are unaffected by the debate over momentum balance in light-matter interactions.

Philbin, T. G. [School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9SS, Scotland (United Kingdom)

2011-01-15

381

Electromagnetically induced absorption via incoherent collisions  

SciTech Connect

We conduct theoretical studies on electromagnetically induced absorption via incoherent collisions in an inhomogeneously broadened ladder-type three-level system with the density-matrix approach. The effects of the collision-induced coherence decay rates as well as the probe laser field intensity on the probe field absorption are examined. It is shown that with the increase of the collisional decay rates in a moderate range, a narrow dip due to electromagnetically induced transparency superimposed on the Doppler-broadened absorption background can be turned into a narrow peak under the conditions that the probe field intensity is not very weak as compared to the pump field, which results from the enhancement of constructive interference and suppression of destructive interference between one-photon and multiphoton transition pathways. The physical origin of the collision-assisted electromagnetically induced absorption is analyzed with a power-series solution of the density-matrix equations.

Yang Xihua [Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701 (United States); Department of Physics, Shanghai University, Shanghai 200444 (China); Sheng Jiteng; Xiao Min [Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701 (United States)

2011-10-15

382

Merging electromagnetism with space-time metric  

E-print Network

In the present work, it is shown that the electromagnetism may be directly associated to the four-dimensional space-time geometry. The starting point is an analysis of the geodesic equation of general relativity where it is verified that it contains implicitly the effects of the Coulomb and the Lorentz forces. Consequently, some components of the metric tensor are identified with the components of the four-vector electromagnetic potential. Then, it is constructed a low-field equation for the electromagnetism in the same structure of the Einstein field equations for the gravitation, relating the curvature of space-time to sources of charge and current density. In this framework, all the Maxwell equations are implicit. A proof of consistency with the framework of quantum mechanics is shown.

C. A. Duarte

2014-01-29

383

Electromagnetic Radiations as a Fluid Flow  

E-print Network

We combine Maxwell's equations with Eulers's equation, related to a velocity field of an immaterial fluid, where the density of mass is replaced by a charge density. We come out with a differential system able to describe a relevant quantity of electromagnetic phenomena, ranging from classical dipole waves to solitary wave-packets with compact support. The clue is the construction of an energy tensor summing up both the electromagnetic stress and a suitable mass tensor. With this right-hand side, explicit solutions of the full Einstein's equation are computed for a wide class of wave phenomena. Since our electromagnetic waves may behave and interact exactly as a material fluid, they can create vortex structures. We then explicitly analyze some vortex ring configurations and examine the possibility to build a model for the electron.

Daniele Funaro

2009-11-25

384

Complex geometry and pre-metric electromagnetism  

E-print Network

The intimate link between complex geometry and the problem of the pre-metric formulation of electromagnetism is explored. In particular, the relationship between 3+1 decompositions of R4 and the decompositions of the vector space of bivectors over R4 into real and imaginary subspaces relative to a choice of complex structure is emphasized. The role of the various scalar products on the space of bivectors that are defined in terms of a volume element on R4 and a complex structure on the space of bivectors that makes it C-linear isomorphic to C3 is discussed in the context of formulation of a theory of electromagnetism in which the Lorentzian metric on spacetime follows as a consequence of the existence of electromagnetic waves, not a prior assumption.

D. H. Delphenich

2004-12-10

385

PhET Simulation: Magnets and Electromagnets  

NSDL National Science Digital Library

In this interactive simulation, users explore the interactions between a compass and a bar magnet and investigate characteristics of electromagnets. This resource was developed to help students build a foundation to understand electromagnetism and factors affecting magnetic field strength. It is appropriate for use in middle school and high school, and could also be adapted for use in college physics preparatory courses. This resource is part of the PhET project (Physics Education Technology) a growing collection of simulations and curriculum support for teachers and learners of physics, biology, chemistry, and earth science. See Related Items for a link to a standards-based lesson plan and elicitation questions developed specifically to accompany the "Magnets and Electromagnets" simulation.

2010-12-02

386

Tracing buried pipelines using multi frequency electromagnetic  

NASA Astrophysics Data System (ADS)

In this paper the application of multi frequency electromagnetic techniques to locate buried pipelines is described. The survey site has two pipelines of SUMED, one of the world chokepoints. At desert or arid areas, regular geophysical surveys usually are difficult to carry out. EM techniques could be the best among geophysical techniques to be used for this target at these conditions. The EM survey was performed using a GEM-300 multi-frequency electromagnetic profiler. It is of handheld electromagnetic induction-type that measures in-phase and quadrature terrain conductivity without electrodes or direct soil contact. An area of 60 15 m was surveyed, that supposed SUMED pipeline existed. Six different frequencies, typically 2025, 2875, 4125, 5875, 8425, 12,025 Hz, have been used simultaneously. The slice maps for in-phase and conductivity distribution at each frequency could help to trace the extension of the pipeline. Two pipelines were traced successfully with 20 m spacing of each others.

El-Qady, Gad; Metwaly, Mohamed; Khozaym, Ashraf

2014-06-01

387

Massless Dirac fermions in an electromagnetic field  

NASA Astrophysics Data System (ADS)

We study the relations between massless Dirac fermions in an electromagnetic field and atoms in quantum optics. After getting the solutions for 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 such 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 an electromagnetic field prepared in general pure quantum states, we analyze the Rabi oscillation. Evaluating the time evolution of the Dirac position operator, we determine the Zitterbewegung frequency and the corresponding oscillating term as a function of the electromagnetic field.

Jellal, Ahmed; El Mouhafid, Abderrahim; Daoud, Mohammed

2012-01-01

388

Electromagnetic properties of viscous charged fluids  

E-print Network

We provide a general theoretical framework to describe the electromagnetic properties of viscous charged fluids, consisting for example of electrons in certain solids or plasmas. We confirm that finite viscosity leads to multiple modes of evanescent electromagnetic waves at a given frequency, one of which is characterized by a negative index of refraction, as previously discussed in a simplified model by one of the authors. In particular we explain how optical spectroscopy can be used to probe the viscosity. We concentrate on the impact of this on the coefficients of refraction and reflection at the sample-vacuum interface. Analytical expressions are obtained relating the viscosity parameter to the reflection and transmission coefficients of light. We demonstrate that finite viscosity has the effect to decrease the reflectivity of a metallic surface, while the electromagnetic field penetrates more deeply. While on a phenomenological level there are similarities to the anomalous skin effect, the model presente...

Forcella, Davide; Valentinis, Davide; van der Marel, Dirk

2014-01-01

389

Electromagnetic wave collapse in a radiation background  

E-print Network

The nonlinear interaction, due to quantum electrodynamical (QED) effects, between an electromagnetic pulse and a radiation background is investigated, by combining the methods of radiation hydrodynamics with the QED theory for photon-photon scattering. For the case of a single coherent electromagnetic pulse we obtain a Zakharov-like system, where the radiation pressure of the pulse acts as a driver of acoustic waves in the photon gas. For a sufficiently intense pulse and/or background energy density there is focusing and subsequent collapse of the pulse. The relevance of our results for various astrophysical applications are discussed.

Mattias Marklund; Gert Brodin; Lennart Stenflo

2003-10-17

390

Null electromagnetic fields and relative CR embeddings  

E-print Network

This paper applies the notion of relative CR embeddings to study two related questions. First, it answers negatively the question posed by Penrose whether every shear-free null rotating congruence is analytic. Second, it proves that given any shear-free null rotating congruence, there exists a null electromagnetic field which is null with respect to the given congruence. In the course of answering these questions, we introduce some new techniques for studying null electromagnetic fields and shear-free congruences in general based on the notion of a relative CR embedding.

Jonathan Earl Holland; George Sparling

2012-02-06

391

Electromagnetic waves, gravitational coupling and duality analysis  

E-print Network

In this letter we introduce a particular solution for parallel electric and magnetic fields, in a gravitational background, which satisfy free-wave equations and the phenomenology suggested by astrophysical plasma physics. These free-wave equations are computed such that the electric field does not induce the magnetic field and vice-versa. In a gravitational field, we analyze the Maxwell equations and the corresponding electromagnetic waves. A continuity equation is presented. A commutative and noncommutative analysis of the electromagnetic duality is described.

E. M. C. Abreu; C. Pinheiro; S. A. Diniz; F. C. Khanna

2005-10-27

392

Device and method for redirecting electromagnetic signals  

DOEpatents

A device fabricated to redirect electromagnetic signals, the device including a primary driver adapted to provide a predetermined force, a linkage system coupled to the primary driver, a pusher rod rotationally coupled to the linkage system, a flexible rod element attached to the pusher rod and adapted to buckle upon the application of the predetermined force, and a mirror structure attached to the flexible rod element at one end and to the substrate at another end. When the predetermined force buckles the flexible rod element, the mirror structure and the flexible rod element both move to thereby allow a remotely-located electromagnetic signal directed towards the device to be redirected.

Garcia, Ernest J. (823 Piedra Larga, NE., Albuquerque, NM 87123)

1999-01-01

393

The Electromagnetic Duality Formulation of Geometric Phases  

NASA Astrophysics Data System (ADS)

This paper focuses on the electromagnetic(EM) duality formulation of geometric phases of Aharonov-Bohm(A-B) effect and Aharonov-Casher(A-C) effect. Through the two four-vector potential formulation of electromagnetic theory, we construct a EM duality formulation for both A-B effect and A-C effect. The He-McKellar-Wilkens(HMW) effect is included as a EM duality counterpart of the A-C effect, and also the EM duality counterpart of the A-B effect is also predicted.

Zhang, Yuchao; Li, Kang

2014-11-01

394

Asymmetric transmission for linearly polarized electromagnetic radiation.  

PubMed

Metamaterials have shown to support the intriguing phenomenon of asymmetric electromagnetic transmission in the opposite propagation directions, for both circular and linear polarizations. In the present article, we propose a criterion on the relationship among the elements of transmission matrix, which allows asymmetrical transmission for linearly polarized electromagnetic radiation only while the reciprocal transmission for circularly one. Asymmetric hybridized metamaterials are shown to satisfy this criterion. The influence from the rotation of the sample around the radiation propagation direction is discussed. A special structure design is proposed, and its characteristics are analyzed by using numerical simulation. PMID:21643086

Kang, Ming; Chen, Jing; Cui, Hai-Xu; Li, Yongnan; Wang, Hui-Tian

2011-04-25

395

Phenomenology of the Deuteron Electromagnetic Form Factors  

E-print Network

A rigorous extraction of the deuteron charge form factors from tensor polarization data in elastic electron-deuteron scattering, at given values of the 4-momentum transfer, is presented. Then the world data for elastic electron-deuteron scattering is used to parameterize, in three different ways, the three electromagnetic form factors of the deuteron in the 4-momentum transfer range 0-7 fm^-1. This procedure is made possible with the advent of recent polarization measurements. The parameterizations allow a phenomenological characterization of the deuteron electromagnetic structure. They can be used to remove ambiguities in the form factors extraction from future polarization data.

TheJLAB t20 collaboration; D. Abbott

2000-02-04

396

Scanning evanescent electro-magnetic microscope  

DOEpatents

A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.

Xiang, Xiao-Dong (Alameda, CA); Gao, Chen (Anhui, CN); Schultz, Peter G. (La Jolla, CA); Wei, Tao (Sunnyvale, CA)

2003-01-01

397

Scanning evanescent electro-magnetic microscope  

DOEpatents

A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.

Xiang, Xiao-Dong (Alameda, CA); Gao, Chen (Alameda, CA)

2001-01-01

398

Electromagnetic Observables in Few-Nucleon Systems  

E-print Network

The electromagnetic probe is a very valuable tool to study the dynamics of few nucleons. It can be very helpful in shedding light on the not yet fully understood three-nucleon forces. We present an update on the theoretical studies of electromagnetic induced reactions, such as photo-disintegration and electron scattering off 4He. We will show that they potentially represent a tool to discriminate among three-nucleon forces. Then, we will discuss the charge radius and the nuclear electric polarizability of the 6He halo nucleus.

Sonia Bacca

2012-10-10

399

Duality in Off-Shell Electromagnetism  

E-print Network

In this paper, we examine the Dirac monopole in the framework of Off-Shell Electromagnetism, the five dimensional U(1) gauge theory associated with Stueckelberg-Schrodinger relativistic quantum theory. After reviewing the Dirac model in four dimensions, we show that the structure of the five dimensional theory prevents a natural generalization of the Dirac monopole, since the theory is not symmetric under duality transformations. It is shown that the duality symmetry can be restored by generalizing the electromagnetic field strength to an element of a Clifford algebra. Nevertheless, the generalized framework does not permit us to recover the phenomenological (or conventional) absence of magnetic monopoles.

Martin Land

2006-03-21

400

Classical quarks in dual electromagnetic fields  

E-print Network

Electromagnetic properties of quark-like particles are examined in a classical field model involving extended dual electromagnetic fields. These can have fractional charges and a confining potential that derives essentially completely from a short-range weaker potential. The combined potentials exhibit an asymptotically free spherical surface and contribute to the masses of the particles. The quarks are shown to have an intrinsic symmetry that describes their structures in hadrons. Multi- quark solutions are easily obtained for both stable and unstable particles. Each quark can undergo simple harmonic motion in a range of frequencies.

Harry Schiff

2010-12-05

401

NASA GRC High Power Electromagnetic Thruster Program  

NASA Technical Reports Server (NTRS)

High-power electromagnetic thrusters have been proposed as primary in-space propulsion options for several bold new interplanetary and deep-space missions. As the lead center for electric propulsion, the NASA Glenn Research Center designs, develops, and tests high-power electromagnetic technologies to meet these demanding mission requirements. Two high-power thruster concepts currently under investigation by Glenn are the magnetoplasmadynamic (MPD) thruster and the Pulsed Inductive Thruster (PIT). This paper describes the MPD thruster and the test facility.

LaPointe, Michael R.; Pensil, Eric J.

2004-01-01

402

Electromagnetic continuous casting project: Final report  

SciTech Connect

This report describes the work on development of an electromagnetic casting process for steel, which was carried out at Argonne National Laboratory between January 1985 and December 1987. This effort was concerned principally with analysis and design work on magnet technology, liquid metal feed system, coolant system, and sensors and process controllers. Experimentation primarily involved (1) electromagnetic studies to determine the conditions and controlling parameters for stable levitation and (2) feed-system studies to establish important parameters that control and influence fluid flow from the liquid metal source to the caster. 73 refs., 91 figs., 11 tabs.

Battles, J.E.; Rote, D.M.; Misra, B.; Praeg, W.F.; Hull, J.R.; Turner, L.R.; Shah, V.L.; Lari, R.J.; Gopalsami, N.; Wiencek, T.

1988-10-01

403

Passive electromagnetic damping device for motion control of building structures  

E-print Network

The research presented in this thesis develops a new device for the passive control of motion in building structures: an electromagnetic damper. The electromagnetic damper is a self-excited device that provides a reaction ...

Palomera-Arias, Rogelio, 1972-

2005-01-01

404

Evolution of electromagnetic waves radiated by a Hertzian dipole  

Microsoft Academic Search

Evolution of electromagnetic waves, despite their use for more than century, is still not known. It was written much about poor understanding of the nature of electromagnetic waves. For example, Nobel Prize R. Feynman [1] writes: \\

V. I. Naidenko

2011-01-01

405

An overview of electromagnetic interference problems in spacecraft  

NASA Technical Reports Server (NTRS)

Electromagnetic Interference Workshop held at JPL /Feb., 1968/ permitted an exchange of information on electromagnetic interference problems encountered in aerospace programs. The experiences related at this workshop dealt primarily with Surveyor, Lunar Orbiter, OGO, ATS, and Mariner unmanned programs.

Bastow, J. G.

1969-01-01

406

Electromagnetic Interference in Wireless Communications: Behavioral-Level Simulation  

E-print Network

Electromagnetic Interference in Wireless Communications: Behavioral-Level Simulation Approach in electromagnetic interference (EMI) modeling and simulation for modern and future wireless communication systems and networks taking into account nonlinear interference effects are discussed in this paper. It is emphasized

Loyka, Sergey

407

Electromagnetic Light in Medium of Polarized Atoms $^3$He  

E-print Network

First, it is predicted that polarized atoms $^3$He increase a value of speed electromagnetic waves. This reasoning implies that the velocity of electromagnetic waves into gas consisting of polarized atoms $^3$He is rather than one in vacuum.

V. N. Minasyan

2008-09-01

408

Accurate Estimation of Electromagnetic Wave Extinction through Foliage  

E-print Network

for estimation of electromagnetic wave extinction in forested environment over long distances.Accurate Estimation of Electromagnetic Wave Extinction through Foliage Feinian Wang Radiation is introduced to model the wave propagation behavior through long distance forested environments. It divides

Sarabandi, Kamal

409

Fractional Diffusion Modeling of Electromagnetic Induction in Fractured Rocks  

E-print Network

The controlled-source electromagnetic (CSEM) technique is well-established for non-invasive geophysical survey. Due to the strong attenuation of earth materials to electromagnetic signals, the effective depth of most CSEM surveys is restricted to 1...

Ge, Jianchao

2014-08-11

410

Electromagnetic drift modes in an inhomogeneous electron gas  

Microsoft Academic Search

A pair of nonlinear equations is derived which describes the dynamics of the electromagnetic drift oscillations in a nonuniform magnetized electron gas. It is shown that the nonlinear electromagnetic drift modes can propagate in the form of dipole vortices.

P. K. Shukla; H. L. Pcseli; J. Juul Rasmussen

1986-01-01

411

Broadband electromagnetic scattering by particles Michael I. Mishchenko  

E-print Network

Broadband electromagnetic scattering by particles Michael I. Mishchenko NASA Goddard Institute, in fact, questionable and do not fol- low from the fundamental concept of electromagnetic scattering constitutive relations, which state that the electric displacement D, the magnetic induction B

412

ECE 341: Electromagnetic Fields I EM devices and systems  

E-print Network

in material media - Electromagnetic induction - Inductance - Magnetic energy Applications: - ElectronicsECE 341: Electromagnetic Fields I EM devices and systems - Can compute and analyze potentials compositions - Can evaluate capacitance, inductance, resistance, and conductance of EM structures - Understands

Schumacher, Russ

413

Evaluation of Electromagnetic Induction as a Reconnaissance Technique to Characterize  

E-print Network

296 Evaluation of Electromagnetic Induction as a Reconnaissance Technique to Characterize The use of apparent electrical conductivity (ECa) measured with electromagnetic (EM) induction Introduction Noninvasive techniques such as EM induction are becoming increasingly popular because they can

Scanlon, Bridget R.

414

Target Detection and Characterization from Electromagnetic Induction Data  

E-print Network

Target Detection and Characterization from Electromagnetic Induction Data Habib Ammari Junqing Chen for imaging small volume conduc- tive inclusions of arbitrary shapes from electromagnetic induction data, induction data, asymptotic formula, detection test, localization, charac- terization, Hadamard technique

415

Ben Zion Steinberg Electromagnetic Waves -Propagation and Scattering  

E-print Network

Ben Zion Steinberg Electromagnetic Waves - Propagation and Scattering Nano photonics] Mazor , Steinberg, PRB 86 045120 (2012) #12; Photonic Crystals Structural Disorder Optical and Microwave Devices Antennas Miniaturization and Isolation Electromagnetic Waves - Propagation and Scattering

Steinberg, Ben

416

ECE-360: Electromagnetic Fields and Waves Spring 2011  

E-print Network

: "Fundamentals of Applied Electromagnetics", 6th edition by Fawwaz T. Ulaby Chapter- 1) Introduction Chapter- 2ECE-360: Electromagnetic Fields and Waves Spring 2011 Instructor: Mani Hossein-Zadeh Office hour

New Mexico, University of

417

611: Electromagnetic Theory II Special relativity; Lorentz covariance of Maxwell equations  

E-print Network

611: Electromagnetic Theory II CONTENTS · Special relativity; Lorentz covariance of Maxwell · Action principle for electromagnetism; energy-momentum tensor · Electromagnetic waves; waveguides Electromagnetic Fields 42 3.1 Description in terms of potentials

Pope, Christopher

418

611: Electromagnetic Theory II Special relativity; Lorentz covariance of Maxwell equations  

E-print Network

611: Electromagnetic Theory II CONTENTS #15; Special relativity; Lorentz covariance of Maxwell particles #15; Action principle for electromagnetism; energy-momentum tensor #15; Electromagnetic waves Electromagnetic Fields 38 3.1 Description in terms of potentials

Pope, Christopher

419

611: Electromagnetic Theory II . Special relativity; Lorentz covariance of Maxwell equations  

E-print Network

611: Electromagnetic Theory II CONTENTS . Special relativity; Lorentz covariance of Maxwell . Action principle for electromagnetism; energy­momentum tensor . Electromagnetic waves; waveguides Electromagnetic Fields 42 3.1 Description in terms of potentials

Pope, Christopher

420

Vibration Isolation using a Shunted Electromagnetic S. Behrens, A. J. Fleming, S. O. R. Moheimani  

E-print Network

Vibration Isolation using a Shunted Electromagnetic Transducer S. Behrens, A. J. Fleming, S. O. R transducer, and actuate using an electromagnetic transducer. Electromagnetic transducers can be used ABSTRACT By attaching an electromagnetic transducer to a mechanical isolation system and shunting

Fleming, Andrew J.

421

Interactions between Electromagnetic Fields and Biological Tissues: Questions, Some Answers and Future Trends.  

E-print Network

The daily exposure to an electromagnetic environment raises the question of the effects of electromagneticInteractions between Electromagnetic Fields and Biological Tissues: Questions, Some Answers and Future Trends. Abstract This paper deals with the electromagnetic field computation in biological

Poignard, Clair

422

ARMY ELECTROMAGNETIC SPECTRUM DISTRIBUTION RESTRICTION. Approved for public release; distribution is unlimited.  

E-print Network

FM 6-02.70 ARMY ELECTROMAGNETIC SPECTRUM OPERATIONS May 2010 DISTRIBUTION RESTRICTION. Approved ELECTROMAGNETIC SPECTRUM OPERATIONS Contents Page PREFACE .............................................................................................................iii Chapter 1 ELECTROMAGNETIC SPECTRUM OPERATIONS INTRODUCTION............ 1-1 What is Electromagnetic

US Army Corps of Engineers

423

Neutrino electromagnetic interactions: a window to new physics  

E-print Network

We review the theory and phenomenology of neutrino electromagnetic interactions, which give us powerful tools to probe the physics beyond the Standard Model. After a derivation of the general structure of the electromagnetic interactions of Dirac and Majorana neutrinos in the one-photon approximation, we discuss the effects of neutrino electromagnetic interactions in terrestrial experiments and in astrophysical environments. We present the experimental bounds on neutrino electromagnetic properties and we confront them with the predictions of theories beyond the Standard Model.

Carlo Giunti; Alexander Studenikin

2014-03-25

424

Analysis and simulation of electromagnetic transients in  

E-print Network

Analysis and simulation of electromagnetic transients in HVAC cable transmission grids Filipe in Electrical Engineering. The research was conducted at the Department of Energy Technology for Energinet.dk, of which I was hired as an employee for the entire project. The project has been followed full time

Silva, Filipe Faria Da

425

Electromagnetic Radiation and Motion of Real Particle  

E-print Network

Relativistically covariant equation of motion for real dust particle under the action of electromagnetic radiation is derived. The particle is neutral in charge. Equation of motion is expressed in terms of particle's optical properties, standardly used in optics for stationary particles.

Jozef Klacka

2001-06-21

426

Out-of-equilibrium electromagnetic radiation  

E-print Network

We derive general formulas for photon and dilepton production rates from an arbitrary non-equilibrated medium from first principles in quantum field theory. At lowest order in the electromagnetic coupling constant, these relate the rates to the unequal-time in-medium photon polarization tensor and generalize the corresponding expressions for a system in thermodynamic equilibrium. We formulate the question of electromagnetic radiation in real time as an initial value problem and consistently describe the virtual electromagnetic dressing of the initial state. In the limit of slowly evolving systems, we recover known expressions for the emission rates and work out the first correction to the static formulas in a systematic gradient expansion. Finally, we discuss the possible application of recently developed techniques in non-equilibrium quantum field theory to the problem of electromagnetic radiation. We argue, in particular, that the two-particle-irreducible (2PI) effective action formalism provides a powerful resummation scheme for the description of multiple scattering effects, such as the Landau-Pomeranchuk-Migdal suppression recently discussed in the context of equilibrium QCD.

Julien Serreau

2004-06-22

427

The wave structure of monochromatic electromagnetic radiation  

Microsoft Academic Search

The paper considers a general field of electromagnetic waves of a single frequency and identifies the salient structurally stable features of the three-dimensional pattern of polarization. The approach is geometrical rather than analytical, and it differs from previous treatments of this kind by being applicable even when the constituent plane waves are travelling in all directions. Lines and surfaces exist

J. F. Nye; J. V. Hajnal

1987-01-01

428

CONTINUUM ELECTROMAGNETIC RADIATION FROM SOLAR FLARES  

Microsoft Academic Search

Continuum electromagnetic radiation from solar flares is discussed in ; terms of the energy loss processes of electrons in the solar atmosphere. It is ; shown that it is possible to attribute the continuum radiation both at radio ; frequencies and at visible frequencies to synchrotron radiation by exponential ; rigidity distributions of electrons. (auth);

W. A. Stein; E. P. Ney

1963-01-01

429

Influence of Absorbers on the Electromagnetic Radiation  

E-print Network

The phenomenon of the electromagnetic absorption by arbitrarily distributed discrete absorbers is analyzed from the photon point of view. It is shown that apart from the decrease in the intensity of the signal the net effect of absorption includes a relative increase in the photon bunching.

Neil V. Budko

2007-12-05

430

Electromagnetic scattering by perfectly conducting open surfaces  

Microsoft Academic Search

The behavior of simple layer potentials and their spatial derivatives near the edge of an open surface is analyzed. Conditions are determined on the surface geometry and on the density distributions for which the potentials have locally finite energy. These results are applied to the formulation problems of electromagnetic scattering from open surface as integral equations. It is shown that

J. S. Asvestas

1977-01-01

431

Electromagnetic particle codes on unstructured grids  

NASA Astrophysics Data System (ADS)

The most widely used computational model of collisionless plasmas is the Lagrangian-Eulerian hybrid technique known as particle-in-cell or PIC. In the electromagnetic version, Maxwell's equations are solved on an Eulerian grid and electromagnetic forces are interpolated from the grid to particle locations. Particles are then moved in Lagrangian fashion while their currents are interpolated back onto the grid to provide sources for the fields on the next cycle. There are many applications where one needs to model plasmas and electromagnetic waves inside regions of complicated shape. Traditional methods for solving Maxwell's equations employ finite differences on regular grids to replace differential operators. These methods are awkward for complicated boundary shapes, often replacing smoothly curved or slanted boundaries with stairsteps. The desire to incorporate realistic boundaries into plasma simulations is motivated by a host of situations in which proper representation of the boundary shape is expected to be critical. The approach to solving this problem is to design electromagnetic particle codes based on the use of unstructured grids. The arbitrary connectivity of unstructured grids provides the flexibility to place nodes wherever needed to fit the most complex boundary shapes. The most significant problems that must be addressed as a result of this strategy are grid generation, field solution, and particle tracking. The solutions to these problems, along with a few preliminary results, are presented.

Ambrosiano, John J.; Brandon, Scott T.; Loehner, Rainald

1990-06-01

432

Electromagnetic compatibility design guideline for STADAN  

NASA Technical Reports Server (NTRS)

Procedures for achieving electromagnetic compatibility in electronic and electrical equipment for aerospace ground stations are investigated. The application of shielding theory to good design is treated and standards of good practice are outlined for bonding, grounding, wiring, and cabling. Some aspects of filter design are explained, and suggestions are given for the application of filters to electronic and electrical equipment.

Cowdell, R. B.; Hill, J. S.; Senn, J. C.; Shifman, J. C.; Skaggs, J. W.

1971-01-01

433

-59 -llc1 LIGHTNING ELECTROMAGNETIC FIELDS  

E-print Network

- 59 - llc1 LIGHTNING ELECTROMAGNETIC FIELDS: MODELING AND MEASUREMENTS V. A. Rakov University of Florida, Gainesville, FL, USA Abs&&: Modeling of lightning return strokes as sourcesof elwc fields is reviewed. Validation of the models using measured fields due to natural and triggered lightning

Florida, University of

434

Relativistic strings and electromagnetic flux tubes  

Microsoft Academic Search

The physical significance of electromagnetic fields with rank 2 - i.e. for which E.B=0 - and which are obtained from the relativistic string via Plcker's coordinates, is discussed, especially the relation of the resulting flux tubes to electric and magnetic confinement.

H. A. Kastrup

1979-01-01

435

Generalized Electromagnetic fields in Chiral Medium  

E-print Network

The time dependent Dirac-Maxwell's Equations in presence of electric and magnetic sources are written in chiral media and the solutions for the classical problem are obtained in unique simple and consistent manner. The quaternion reformulation of generalized electromagnetic fields in chiral media has also been developed in compact, simple and consistent manner.

P. S. Bisht; Jivan Singh; O. P. S. Negi

2007-03-12

436

Electromagnetic Siegert states for periodic dielectric structures  

E-print Network

The formalism of Siegert states to describe the resonant scattering in quantum theory is extended to the resonant scattering of electromagnetic waves on periodic dielectric arrays. The excitation of electromagnetic Siegert states by an incident wave packet and their decay is studied. The formalism is applied to develop a theory of coupled electromagnetic resonances arising in the electromagnetic scattering problem for two such arrays separated by a distance 2h (or, generally, when the physical properties of the scattering array depend on a real coupling parameter h). Analytic properties of Siegert states as functions of the coupling parameter h are established by the Regular Perturbation Theorem which is an extension the Kato-Rellich theorem to the present case. By means of this theorem, it is proved that if the scattering structure admits a bound state in the radiation continuum at a certain value of the coupling parameter h, then there always exist regions within the structure in which the near field can be amplified as much as desired by adjusting the value of h. This establishes a rather general mechanism to control and amplify optical nonlinear effects in periodically structured planar structures possessing a nonlinear dielectric susceptibility.

Friends R. Ndangali; Sergei V. Shabanov

2011-08-09

437

Electromagnetic Transducer for Hybrid Electric Vehicles  

Microsoft Academic Search

This paper describes a novel electromagnetic transducer called the Four Quadrant Transducer (4QT) for hybrid electric vehicles. The system consists of one electrical machine unit (including two rotors) and two inverters, which enable the vehicle's Internal Combustion Engine (ICE) to run at its optimum working points regarding efficiency, almost independently of the changing load requirements at the wheels. In other

Freddy Magnussen; Chandur Sadarangani

2002-01-01

438

The electromagnetic calorimeter for the OBELIX experiment  

Microsoft Academic Search

We describe the electromagnetic calorimeter of the OBELIX detector installed on the LEAR facility at CERN: the criteria followed to design its structure and the tests and preparation work performed on the different components are discussed, to conclude with the description of the main control procedures operating on the assembled detector during the first tests of the apparatus on the

S. Affatato; G. Artusi; G. Avoni; O. Baglioni; A. Bertin; M. Bruschi; D. Bulgarelli; M. Capponi; I. D'Antone; S. de Castro; D. Galli; U. Marconi; I. Massa; M. Morganti; G. Paolucci; M. Piccinini; M. Poli; N. Semprini-Cesari; R. Spighi; S. Tuffanelli; S. Vecchi; M. Villa; A. Vitale; S. Zagato; G. Zavattini; A. Zoccoli

1993-01-01

439

Effects of hydrometeors on electromagnetic wave propagation  

NASA Astrophysics Data System (ADS)

Attenuation of electromagnetic (EM) waves by Hydrometers such as rain, snow, clouds, and fog, can cause serious degradation of EM wave systems. This report describes such attenuation of radio waves to X-rays, with primary applications to communications in the microwave and millimeter wave portions of the EM spectrum.

Ebersole, J. F.; Cheng, W. K.; Hallett, J.; Hohlfeld, R. G.

1985-01-01

440

Electromagnetic-wave propagation along curved surfaces  

SciTech Connect

We show that Maxwell's equations for a nonmagnetic, isotropic, but electrically inhomogeneous medium in the absence of charges or current sources lead to a wave equation governing surface electromagnetic wave propagation along a general curved, smooth surface which, when recasted using an appropriate choice of curvilinear coordinates u{sup 1},u{sup 2},u{sup 3}, can be fully separated in the spatial dimensions. It is shown that surface electromagnetic wave solutions decay exponentially away from the surface (along the u{sup 3} coordinate) with the same decay rate independent of the shape of the surface. Transmission and reflection coefficients governing scattering of electromagnetic waves on a varying surface shape are derived. Two test cases of a Gaussian-shaped and a sinusoidal-shaped surface are solved in details and discussed numerically in terms of transmission and reflection coefficients including dependencies on surface-shape parameters in the wavelength range 250-750 nm. The present method for determining surface electromagnetic wave propagation along complex-shaped metal-dielectric surfaces allows better insight into the importance of surface geometry as well as considerably faster computational speeds than those provided by standard numerical methods.

Willatzen, M. [Mads Clausen Institute for Product Innovation, University of Southern Denmark, Alsion 2, DK-6400 Soenderborg (Denmark)

2009-10-15

441

Electromagnetic Spectrum: Distribution of Radiant Energies  

NSDL National Science Digital Library

This item is a beginning tutorial on the electromagnetic spectrum designed for students of introductory physics. It provides multiple plots of the spectrum to aid users in understanding various EM spectrum classifications. This item is part of a larger tutorial on the topic of Remote Sensing, sponsored by the NASA Goddard Program office.

Short, Nicholas M.

2008-06-12

442

Electromagnetic Generation of Ultrasonic Waves in Bismuth  

Microsoft Academic Search

Measurements were made of electromagnetic generation of ultrasonic shear and longitudinal waves at liquid-helium temperatures in several single crystals of bismuth for each of the three principal crystallographic axes. Measurements were made over the frequency range 5-50 MHz. In addition to giant quantum oscillations (GQO) in the generation efficiency, which were observed in all cases, detailed studies of a pronounced

D. Hsu; R. L. Thomas

1972-01-01

443

Electromagnetic wave scattering in dusty plasmas  

Microsoft Academic Search

The cross section for transition scattering of electromagnetic waves on charged dust particles in a plasma is calculated. For the case of nonlinear screening of the charged dust by the plasma particles, numerical and analytical results are presented, showing a significant enhancement, proportional to the square of the grain surface charge, in the cross section with respect to scattering by

R. Bingham; U. de Angelis; V. N. Tsytovich; O. Havnes

1991-01-01

444

Controlling photons using electromagnetically induced transparency  

Microsoft Academic Search

It is well known that a dielectric medium can be used to manipulate properties of light pulses. However, optical absorption limits the extent of possible control: this is especially important for weak light pulses. Absorption in an opaque medium can be eliminated via quantum mechanical interference, an effect known as electromagnetically induced transparency. Theoretical and experimental work has demonstrated that

M. D. Lukin; A. Imamoglu

2001-01-01

445

The radiative transfer approach in electromagnetic imaging  

Microsoft Academic Search

After presenting the general formulation of the complete electromagnetic imaging radiative transfer equation using the Stokes' vectors, including the extinction matrix and the Mueller scattering matrix, the coherent and incoherent Stokes' vectors corresponding to the coherent and incoherent fields are defined. The coherent Stokes' vector has a depolarization effect; solutions for the vector radiative transfer equation require Fourier decomposition to

A. Ishimaru

1985-01-01

446

The Good, the Bad and the Electromagnet  

NSDL National Science Digital Library

Using plastic straws, wire, batteries and iron nails, student teams build and test two versions of electromagnetsone with and one without an iron nail at its core. They test each magnet's ability pick up loose staples, which reveals the importance of an iron core to the magnet's strength. Students also learn about the prevalence and importance of electromagnets in their everyday lives.

STARS GK-12 Program,

447

Finite element modeling of electromagnetic NDT phenomena  

Microsoft Academic Search

The development of computer-based defect characterization schemes for automated electromagnetic methods of nondestructive testing (NDT) requires adequate mathematical models to describe the complicated interactions of currents, fields and defects in materials. This paper describes the finite element equations governing active, residual and eddy current phenomena in materials with discontinuities and magnetic nonlinearity. It is suggested that the resulting magnetic vector

R. Palanisamy; W. Lord

1979-01-01

448

The ElectroMagnet a Receiving Telephone  

Microsoft Academic Search

THE experiment of Mr. F. G. Lloyd, described in NATURE, vol. xviii. p. 488, is simply a repetition of Page's original experiment, the basis, of all telephony. The electro-magnets of ordinary relays and Morse apparatus mate capital telephone receivers when their armatures are screwed up, and it is a common thing for operators at intermediate stations in America to enjoy

W. H. Preece

1878-01-01

449

Accuracy Assessment for AG500, Electromagnetic Articulograph  

ERIC Educational Resources Information Center

Purpose: The goal of this article was to evaluate the accuracy and reliability of the AG500 (Carstens Medizinelectronik, Lenglern, Germany), an electromagnetic device developed recently to register articulatory movements in three dimensions. This technology seems to have unprecedented capabilities to provide rich information about time-varying

Yunusova, Yana; Green, Jordan R.; Mefferd, Antje

2009-01-01

450

Electromagnetic interactions of cosmic rays with nuclei  

NASA Technical Reports Server (NTRS)

Parameterizations of single nucleon emission from the electromagnetic interactions of cosmic rays with nuclei are presented. These parameterizations are based upon the most accurate theoretical calculations available today. When coupled with Strong interaction parameterizations, they should be very suitable for use in cosmic ray propagation through intersteller space, the Earth's atmosphere, lunar samples, meteorites and spacecraft walls.

Norbury, John W.

1989-01-01

451

Electromagnetic interference shielding effectiveness of carbon materials  

Microsoft Academic Search

Carbon materials for electromagnetic interference (EMI) shielding are reviewed. They include composite materials, colloidal graphite and flexible graphite. Carbon filaments of submicron diameter are effective for use in composite materials, especially after electroplating with nickel. Flexible graphite is attractive for EMI gaskets.

D. D. L. Chung

2001-01-01

452

Electromagnetic interference and solid state protective relays  

Microsoft Academic Search

This paper presents new information on the nature of the electromagnetic environment in an electric power station which can influence the performance of modern solid state protective relays and other sensitive electronic control and data processing equipments. Present industry standard tests do not simulate the full range of this environment and may need to be revised. The frequency spectrum of

W. C. Kotheimer; L. L. Mankoff

1977-01-01

453

Electromagnetic Composites at the Compton Scale  

E-print Network

A new class of electromagnetic composite particles is proposed. The composites are very small (the Compton scale), potentially long-lived, would have unique interactions with atomic and nuclear systems, and, if they exist, could explain a number of otherwise anomalous and conflicting observations in diverse research areas.

Frederick J. Mayer; John R. Reitz

2011-09-10

454

The behavior of electromagnetic fields at edges  

Microsoft Academic Search

The behavior of an electromagnetic field in the neighborhood of the common edge of angular dielectric or conducting regions is determined from the condition that the energy density must be integrable over any finite domain (the so-called edge condition). Two cases are treated in detail 1) A region consisting of a conducting wedge and two different dielectric wedges with a

J. Meixner

1972-01-01

455

Relations Among Systems of Electromagnetic Equations  

ERIC Educational Resources Information Center

Contends that the equations of electromagnetism, whether in rationalized or non-rationalized form, express an invariant set of physical relationships. The relationships among corresponding symbols are given and applied to precise statements about the relation between the oersted and the amphere per meter, the abampere and the ampere, etc.

page, Chester H.

1970-01-01

456

Electromagnetism Adapted for Life Science Students  

ERIC Educational Resources Information Center

Describes the study of electronics as a terminal course in electromagnetism. A lecture-laboratory approach is used with a strong emphasis on practical experience. Outlines the major topics of the lecture program and describes the activities used in the laboratory. (GS)

Gurr, F. M.; And Others

1974-01-01

457

Charging Ahead: An Introduction to Electromagnetism.  

ERIC Educational Resources Information Center

This guide explores the connection between electricity and magnetism with middle level and high school students. The phenomenon of electromagnetism is broken down into four lesson plans that provide students and teachers with a carefully constructed yet easy way to learn about their history. All four activities prompt students to use inexpensive,

Shafer, Larry E.

458

Electromagnetic optimization exploiting aggressive space mapping  

Microsoft Academic Search

We propose a significantly improved space mapping (SM) strategy for electromagnetic (EM) optimization. Instead of waiting for upfront EM analyses at several base points, our new approach aggressively exploits every available EM analysis, producing dramatic results right from the first step. We establish a relationship between the novel SM optimization and the quasi-Newton iteration for solving a system of nonlinear

John W. Bandler; R. M. Biernacki; Shao Hua Chen; Ronald H. Hemmers; Kaj Madsen

1995-01-01

459

Energy Mental Models: Mechanics through Electromagnetism  

NSDL National Science Digital Library

We investigated students' mental models for energy, and changes in these models in going from mechanics to electromagnetism contexts. We interviewed students in a two-semester calculus-based physics course. Our research design included semi-structured interviews with demonstration. Based on our findings in the interviews we are developing a first version of an 'Energy Mental Model Inventory.'

Itza-Ortiz, Salomon F.; Lawrence, Benjamin; Zollman, Dean A.

2005-11-02

460

Line geometry and electromagnetism I: basic structures  

E-print Network

Some key notions of line geometry are recalled, along with their application to mechanics. It is then shown that most of the basic structures that one introduces in the pre-metric formulation of electromagnetism can be interpreted directly in terms of corresponding concepts in line geometry. The results are summarized in a table.

D. H. Delphenich

2013-09-11

461

Electromagnetic field interactions with biological systems  

SciTech Connect

This is a report on Symposia organized by the International Society for Bioelectricity and presented at the 1992 FASEB Meeting. The presentations summarized here were intended to provide a sampling of new and fruitful lines of research. The theme topics for the Symposia were cancer, neural function, cell signaling, pineal gland function, and immune system interactions. Living organisms are complex electrochemical systems that evolved over billions of years in a world with a relatively simple weak magnetic field and with few electromagnetic energy emitters. As is characteristic of living organisms, they interacted with and adapted to this environment of electric and magnetic fields. In recent years there has been a massive introduction of equipment that emits electromagnetic fields in an enormous range of new frequencies, modulations, and intensities. As living organisms have only recently found themselves immersed in this new and virtually ubiquitous environment, they have not had the opportunity to adapt to it. This gives biologists the opportunity to use these electromagnetic fields as probes to study the functioning of living systems. This is a significant opportunity, as new approaches to studying living systems so often provide the means to make great leaps in science. In recent years, a diversity of biologists have carried out experiments using electromagnetic fields to study the function of living cells and systems. This approach is now becoming quite fruitful and is yielding data that are advancing our knowledge in diverse areas of biology. 25 refs., 6 figs., 3 tabs.

Frey, A.H. (Randomline Inc., Huntingdon Valley, PA (United States))

1993-02-01

462

Electromagnetically-driven capillary switches and oscillators  

Microsoft Academic Search

By designing pinned-contact, coupled droplet pairs at the appropriate length scale to promote surface tension as the dominant force, one can create bi-stable capillary switches and natural oscillators. These systems have been triggered by pressure pulses, electrochemistry, and electroosmosis. These methods are typically accompanied by bulky setups or slow response times. An alternate approach exploits electromagnetic activation. Our device consists

Bernard Malouin; Amir Hirsa; Michael Vogel

2009-01-01

463

Directional scanning of complex electromagnetic environments  

Microsoft Academic Search

A directional scanning technique is formulated for determining characteristics of an electromagnetic (EM) environment with a relatively small number of measurements, and results of a simulated application are presented. The method relies on measurements with a directional probe to obtain information about the coefficients in a planewave expansion of the field within a large volume. The simulation indicates that although

J. Randa; M. Kanda

1985-01-01

464

Electromagnetic Environment of UHF-RFID  

Microsoft Academic Search

The number of applications that use radio-frequency identification (RFID) technology has grown continually in the last few years. In this presentation we will present the results of research on the electromagnetic environment on RFID systems. We analyze the effects of UHF MHz China RFID system near a GSM frequency bands. Kurokawa's method of calculating the power reflection coefficient from the

Song Li; Xue-tao Weng

2008-01-01

465

Correlation singularities in partially coherent electromagnetic beams.  

PubMed

We demonstrate that coherence vortices, singularities of the correlation function, generally occur in partially coherent electromagnetic beams. In successive cross sections of Gaussian Schell-model beams, their locus is found to be a closed string. These coherence singularities have implications for both interference experiments and correlation of intensity fluctuation measurements performed with such beams. PMID:23073403

Raghunathan, Shreyas B; Schouten, Hugo F; Visser, Taco D

2012-10-15

466

Fractal two-dimensional electromagnetic bandgap structures  

Microsoft Academic Search

Fractal two-dimensional electromagnetic bandgap (EBG) materials are proposed and studied by means of a full-wave method developed for diffraction gratings. Such technique allows us to characterize, In an accurate and rapidly convergent way, the transmission and reflection properties of periodic fractal structures with an arbitrary geometry in the unit cell. Both polarization cases can be treated. A validation of the

Fabrizio Frezza; Lara Pajewski; Giuseppe Schettini

2004-01-01

467

Aspect on Bifurcation of Electromagnetic Vortex Line  

NASA Astrophysics Data System (ADS)

Vortex lines of electromagnetic field are classified by Hopf index, Brouwer degree in geometry. A mechanism of generation or annihilation of the vortex line is given by method of phase singularity theory. The bifurcation behavior at the critical points is discussed in detail.

Xu, Tao; Su, Hongling; Zhou, Gang; Hu, Xiwei

468

Nucleon Electromagnetic Form Factors and Densities  

NASA Astrophysics Data System (ADS)

We review data for nucleon electromagnetic form factors, emphasizing recent measurements of GE/GM that use recoil or target polarization to minimize systematic errors and model dependence. The data are parametrized in terms of densities that are consistent with the Lorentz contraction of the Breit frame and with pQCD.

Kelly, James J.

2004-02-01

469

Transition electromagnetic fields in particle physics  

Microsoft Academic Search

We present a computation of one-loop effective potentials for elementary systems placed in a strong magnetic or a laser-produced electromagnetic environment. This permits a determination in principle of a hierarchy of transition field strengths, for which the systems concerned may (for appropriate values of the parameters in the theory) make transitions from a spontaneously broken asymmetric phase to one of

Abdus Salam; J. Strathdee

1975-01-01

470

FMM Code Libraries for Computational Electromagnetics  

E-print Network

Max Optics, Inc. #12;MadMax Optics 2 · Stealth · Electromagnetic interference · Antennas on complex platforms minutes (Pentium IV, 1.6GHz) #12;MadMax Optics 13 #12;MadMax Optics 14 · Core FMM technology is reasonably

Maryland at College Park, University of

471

Quantized electromagnetic tornado in pulsar vacuum gap  

E-print Network

The solution for the electromagnetic tornado in a vacuum gap of a pulsar that could serve as an explanation of the observed circular polarization of giant pulses from pulsars and might also explain the frequency strips observed in giant pulses spectrum is found.

Kontorovich, V M

2009-01-01

472

Pullback transformation in gyrokinetic electromagnetic simulations  

SciTech Connect

It is shown that a considerable mitigation of the cancellation problem can be achieved by a slight modification of the simulation scheme. The new scheme is verified, simulating a Toroidal Alfvn Eigenmode in tokamak geometry at low perpendicular mode numbers, the so-called MHD limit. Also, an electromagnetic drift mode has been successfully simulated in a stellarator.

Mishchenko, Alexey, E-mail: alexey.mishchenko@ipp.mpg.de; Knies, Axel; Kleiber, Ralf; Cole, Michael [Max Planck Institute for Plasma Physics, D-17491 Greifswald (Germany)

2014-09-15

473

Electromagnetic Dissociation of Light Exotic Nuclei  

Microsoft Academic Search

Reactions of secondary beams at energies of several hundred MeV\\/u are utilized at the GSI radioactive beam facility to explore the structure of unstable nuclei. Scattering of radioactive nuclei can be studied by kine- matically complete measurements with the LAND reaction setup. In the present article, experiments concerning inelastic excitations to the con- tinuum will be discussed utilizing the electromagnetic

Thomas Aumann

474

Electromagnetic Force on a Moving Dipole  

ERIC Educational Resources Information Center

We analyse the force acting on a moving dipole due to an external electromagnetic field and show that the expression derived in Vekstein (1997 "Eur. J. Phys." 18 113) is erroneous and suggest the correct equation for the description of this force. We also discuss the physical meaning of the relativistic transformation of current for a closed

Kholmetskii, Alexander L.; Missevitch, Oleg V.; Yarman, T.

2011-01-01

475

Estimates for Electromagnetically Exciting Nuclear Isomers  

NASA Astrophysics Data System (ADS)

There has been recent interest in the possible roles that nuclear isomers (both spin and shape) might play in high temperature, high neutron flux environments. Such environments are readily available in both applied physics and astrophysical settings. For example, in certain astrophysical environments, a significant change in the effective lifetimes of certain even-even nuclei can occur if their shape isomers are strongly populated. Such events can strongly effect the roles of 'waiting point' nuclei of proton-rich reactions in thermo-nuclear explosions, such as those that cause Type-I X-ray bursts. More mundane examples include the use of spin-isomers as a post-diagnostic tool for studying ignited ICF capsules or terra-based nuclear explosions. Isomers are strongly populated by nucleonic interactions. If temperatures are high enough, there is the additional possibility of populating isomers electromagnetically. Here we examine the the rates for electromagnetic excitation of several spin isomers relevant both in astrophysics and applied physics. We consider six possible electromagnetic processes, namely, photo-absorption, inverse internal conversion, inelastic electron scattering, Coulomb excitation, (?,?') and (e,e'?) reactions. We find that for plasma temperatures T 1-10 keV the electromagnetic reactions rates are negligible compared to neutron reaction rates. Thus, we conclude that these isomers are only populated by neutron excitation.

Luu, Thomas; Friar, James; Hayes, Anna

2004-10-01

476

Ultrafast semiconductor spectroscopy using terahertz electromagnetic pulses  

Microsoft Academic Search

Terahertz electromagnetic pulses can serve as a new and unique tool for various types of spectroscopy. We first characterized the temporal and spatial properties of THz pulses generated from a large-aperture photoconductive antena, and then used them for the study of the ultrafast dynamics of electrons in semiconductros. We studied the dynamics of electrons generated by femtosecond optical pulses with

Toshiaki Hattori; Satoshi Arai; Keisuke Ohta; Aya Mochiduki; Shin-ichi Ookuma; Keiji Tukamoto; Rakchanok Rungsawang

2005-01-01

477

(Revised May 25, 2012) Electromagnetic Induction  

E-print Network

(Revised May 25, 2012) Electromagnetic Induction GOALS (1) To understand what it means to have in the "induction" process precisely through words and pictures for several different cases. INTRODUCTION Magnetic a voltage that drives the flow of current around the circuit. This is simply the induction process. Lenz

Collins, Gary S.

478

(Revised May 25, 2012) Electromagnetic Induction  

E-print Network

(Revised May 25, 2012) Electromagnetic Induction GOALS (1) To understand what it means to have in the "induction" process precisely through words and pictures for several different cases. INTRODUCTION Magnetic that drives the flow of current around the circuit. This is simply the induction process. Lenz's Law

Collins, Gary S.

479

Project Physics Text 4, Light and Electromagnetism.  

ERIC Educational Resources Information Center

Optical and electromagnetic fundamentals are presented in this fourth unit of the Project Physics text for use by senior high students. Development of the wave theory in the first half of the 19th Century is described to deal with optical problems at the early stage. Following explanations of electric charges and forces, field concepts are

Harvard Univ., Cambridge, MA. Harvard Project Physics.

480

Alternating current electromagnetic servo induction meter  

NASA Technical Reports Server (NTRS)

Electromagnetic device accurately indicates the responses of various sensors in high performance flight research aircraft to conditions encountered in flight. The device responds to sensor inputs to move a slideable armature along an indicator scale by the force of currents induced in the armature winding.

Bogue, R. K.

1968-01-01

481

On the Laws of Electromagnetic Induction  

E-print Network

The Faraday-Ampere laws of electro-magnetic induction are formulated in terms of plain and twisted differential forms, taking in due account the body motion in terms of Lie time-derivatives. Covariance of Lie derivatives with respect to arbitrary relative motions, and Galilei invariance of the electro-magnetic fields, imply Galilei invariance of the induction laws, contrary to most claims in literature. A noteworthy outcome of the theory is the conclusion that the so called Lorentz force on a charged particle is not an additional law of electromagnetism, but rather, when corrected by a factor one-half, a contribution to the electric field evaluated, according to Faraday law, by an observer testing a translating charged body crossing a region of uniform magnetic field. The formulation of the laws of electromagnetism in the four dimensional classical space-time, by stating the observer-dependent splitting for bodies in motions, provides a proof of Galilei invariance of all the electric and magnetic fields involved in the analysis.

Giovanni Romano

2012-01-14

482

On the Laws of Electromagnetic Induction  

E-print Network

The Faraday-Ampere laws of electro-magnetic induction are formulated in terms of plain and twisted differential forms, taking in due account the body motion in terms of Lie time-derivatives. Covariance of Lie derivatives with respect to arbitrary relative motions, and Galilei invariance of the electro-magnetic fields, imply Galilei invariance of the induction laws, contrary to most claims in literature. A noteworthy outcome of the theory is the conclusion that the so called Lorentz force on a charged particle is not an additional law of electromagnetism, but rather, when corrected by a factor one-half, a contribution to the electric field evaluated, according to Faraday law, by an observer testing a translating charged body crossing a region of uniform magnetic field. The formulation of the laws of electromagnetism in the four dimensional classical space-time, by stating the observer-dependent splitting for bodies in motions, provides a proof of Galilei invariance of all the electric and magnetic fields invol...

Romano, Giovanni

2011-01-01

483

Subsurface discrimination using electromagnetic induction sensors  

Microsoft Academic Search

This paper reviews the problem of subsurface discrimination using electromagnetic induction (EMI) sensors. Typically, discrimination is based on differences in the multiaxis magnetic polarizability between different objects. They review work on frequency and time domain systems, and their interrelationship. They present the results of comprehensive measurements of the multiaxis EMI response of a variety of inert ordnance items, ordnance fragments,

Thomas H. Bell; Bruce J. Barrow; Jonathan T. Miller

2001-01-01

484

Electromagnetic induction spectroscopy for clearing landmines  

Microsoft Academic Search

An estimated 110 million landmines, mostly antipersonnel mines laid in over 60 countries, kill or maim over 26000 people a year. One of the dilemmas for removing landmines is the amount of false alarms in a typical minefield. Broadband electromagnetic induction spectroscopy (EMIS) is a promising technology that can both detect and identify buried objects as landmines. By reducing the

I. J. Won; Dean A. Keiswetter; Thomas H. Bell

2001-01-01

485

Electromagnetic properties of viscous charged fluids  

E-print Network

We provide a general theoretical framework to describe the electromagnetic properties of viscous charged fluids, consisting for example of electrons in certain solids or plasmas. We confirm that finite viscosity leads to multiple modes of evanescent electromagnetic waves at a given frequency, one of which is characterized by a negative index of refraction, as previously discussed in a simplified model by one of the authors. In particular we explain how optical spectroscopy can be used to probe the viscosity. We concentrate on the impact of this on the coefficients of refraction and reflection at the sample-vacuum interface. Analytical expressions are obtained relating the viscosity parameter to the reflection and transmission coefficients of light. We demonstrate that finite viscosity has the effect to decrease the reflectivity of a metallic surface, while the electromagnetic field penetrates more deeply. While on a phenomenological level there are similarities to the anomalous skin effect, the model presented here requires no particular assumptions regarding the corpuscular nature of the charge liquid. A striking consequence of the branching phenomenon into two degenerate modes is the occurrence in a half-infinite sample of oscillations of the electromagnetic field intensity as a function of distance from the interface.

Davide Forcella; Jan Zaanen; Davide Valentinis; Dirk van der Marel

2014-08-01

486

Strangeness Electromagnetic Production on Nucleons and Nuclei  

E-print Network

Isobar models for the electromagnetic production of kaons are discussed with emphasis on the K^+ photoproduction at very small kaon angles and K^0 photoproduction on deuteron. Distorted-wave impuls approximation calculations of the cross sections for the electroproduction of hypernuclei are presented on the case of the ^{12}B_\\Lambda production.

Petr Bydzovsky; Miloslav Sotona

2009-12-02

487

Structural composites with integrated electromagnetic functionality  

E-print Network

Structural composites with integrated electromagnetic functionality Syrus C. Nemat-Nasser, Alireza, such as wires, into polymer-based or ceramic-based composites. In addition to desired structural properties, these materials may be leveraged for active tasks such as filtering. The advantages of such hybrid composites

Nemat-Nasser, Sia

488

PRODUCTION AND DISTRIBUTION OF ELECTROMAGNETICALLY ENRICHED ISOTOPES  

Microsoft Academic Search

The production and distribution of stable isotopes have been highlighted ; by the recent separation of dysprosium, erbium, and ytterbium isotopes for the ; first time. Highpurity collections of Li⁶ Li⁷, B¹°, and B\\/sup ; 11\\/ have also be en carried out using the large electromagnetic separators. The ; need for samples of ultra-high isotopic purity has led to the

P. S. Baker; W. A. Jr. Bell; W. C. Davis; C. V. Ketron; L. O. Love; J. A. Martin; E. B. Olszewski; W. K. Prater; K. A. Spainhour

1958-01-01

489

Electromagnets applied to thin steel plate  

Microsoft Academic Search

To depress the vibration and meandering of a thin steel plate in a steel making plant, electromagnets are applied to the plate. According to the results of numerical calculation, the different pole arrangement is superior to the same pole arrangement for the vertical position control, though the same pole arrangement is superior to the different pole arrangement for the lateral

Keisuke Fujisaki; Takatsugu Ueyama; Kiyoshi Wajima

1996-01-01

490

Rigorous electromagnetic simulation applied to alignment systems  

Microsoft Academic Search

Rigorous electromagnetic simulation with TEMPEST is used to provide benchmark data and understanding of key parameters in the design of topographical features of alignment marks. Periodic large silicon trenches are analyzed as a function of wavelength (530-800 nm), duty cycle, depth, slope and angle of incidence. The signals are well behaved except when the trench width becomes about 1 micrometers

Yunfei Deng; Thomas V. Pistor; Andrew R. Neureuther

2001-01-01

491

Analysis of waveguides containing EMCs (electromagnetic conductors) or PEMCs (perfect electromagnetic conductors)  

NASA Astrophysics Data System (ADS)

The concept of a perfect electromagnetic conductor (PEMC) was introduced to generalize and unify two well-known and apparently disjoint concepts in electromagnetics: the perfect electric conductor (PEC) and the perfect magnetic conductor (PMC). Although the PEMC has proven a fertile tool in electromagnetic analyses dealing with new and complex boundaries, its corresponding definition as a medium has, nevertheless, raised several problems. In fact, according to its initial 3D definition, the PEMC cannot be considered a unique and well-defined medium: it leads to extraneous fields without physical meaning. By using a previously published generalization of a PEMC that regards this concept both as a boundary and as a medium - which was dubbed an MIM (Minkowskian isotropic medium) and acts, in practice, as an actual electromagnetic conductor (EMC) - it is herein presented a straightforward analysis of waveguides containing PEMCs that readily and systematically follows from the general framework of waveguides containing EMCs.

Prudncio, Filipa R.; Matos, Srgio A.; Paiva, Carlos R.

2014-11-01

492

Comparison of Commercial Electromagnetic Interface Test Techniques to NASA Electromagnetic Interference Test Techniques  

NASA Technical Reports Server (NTRS)

This report documents the development of analytical techniques required for interpreting and comparing space systems electromagnetic interference test data with commercial electromagnetic interference test data using NASA Specification SSP 30237A "Space Systems Electromagnetic Emission and Susceptibility Requirements for Electromagnetic Compatibility." The PSpice computer simulation results and the laboratory measurements for the test setups under study compare well. The study results, however, indicate that the transfer function required to translate test results of one setup to another is highly dependent on cables and their actual layout in the test setup. Since cables are equipment specific and are not specified in the test standards, developing a transfer function that would cover all cable types (random, twisted, or coaxial), sizes (gauge number and length), and layouts (distance from the ground plane) is not practical.

Smith, V.; Minor, J. L. (Technical Monitor)

2000-01-01

493

Effects of current frequency on electromagnetic tube compression  

Microsoft Academic Search

Current frequency is one of the most important parameters that must be analyzed and optimized for the analysis and design of electromagnetic forming process, and its effects on the electromagnetic forming process are very complicated. The influence of frequency on electromagnetic tube compression has been investigated by means of the sequential coupling numerical simulation. The delaying and the total time

Y. U. Haiping; L. I. Chunfeng

2009-01-01

494

Electromagnetic actuator to reduce vibration sources Thibaut Chailloux*  

E-print Network

Electromagnetic actuator to reduce vibration sources Thibaut Chailloux* , L. Morel* , F. Sixdenier), hydraulic or pneumatic actuators, electromagnetic actuators [1], piezoelectric actuators. As part of a study to compensate a vibration on an aircraft engine for which an electromagnetic actuator was recommended. (The

Paris-Sud XI, Université de

495

Electromagnetic Crack Detection Inverse Problems using Terahertz Interrogating Signals  

E-print Network

Electromagnetic Crack Detection Inverse Problems using Terahertz Interrogating Signals H. T. Banks formulation to determine characteristics of a defect from a perturbed electromagnetic interrogating signal of the interfaces, of the windowed interrogating signal. We model the electromagnetic waves inside the material

496

The Electromagnetically Sustained Rhodes Piano Media Arts & Technology (MAT)  

E-print Network

The Electromagnetically Sustained Rhodes Piano Greg Shear Media Arts & Technology (MAT) University Santa Barbara, CA 93106 matt@create.ucsb.edu ABSTRACT The Electromagnetically Sustained Rhodes Piano in the high-gain signal path. Keywords Rhodes, keyboard, electromagnetic, sustain, augmented in- strument

California at Santa Barbara, University of

497

Synthetic aperture controlled source electromagnetics R. Snieder,1  

E-print Network

; accepted 7 June 2010; published 9 July 2010. [1] Controlled source electromagnetics (CSEM) has been used survey, a horizontal current dipole is used as the source to generate an electromagnetic fieldClick Here for Full Article Synthetic aperture controlled source electromagnetics Y. Fan,1 R

Snieder, Roel

498

Soft Tempest: Hidden Data Transmission Using Electromagnetic Emanations  

E-print Network

Soft Tempest: Hidden Data Transmission Using Electromagnetic Emanations Markus G. Kuhn and Ross J on a computer to control the electromagnetic radiation it transmits. This can be used for both attack Using Electromagnetic Emanations 125 handles or transmits unclassified data. Equipment with both `red

Kuhn, Markus

499

Dynamic and Thermal Control of an Electromagnetic Formation Flight Testbed  

E-print Network

the mission. An alternative method for providing this relative position control is to use electromagnetic vehicle position and attitude using only electromagnetic forces and reaction wheels. A thorough. Innovations to the thermal system, used to cool the superconducting wire of the electromagnet, are described

500

A Time Domain Formulation for Identification in Electromagnetic Dispersion  

E-print Network

such as living tis­ #12; sue using incident and scattered electromagnetic signals. The functions of permittivity are commonly used as electromagnetic characteristics. Since our approach is in the time domain, we focusA Time Domain Formulation for Identification in Electromagnetic Dispersion H. T. Banks and M. W