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Sample records for electromagnetic induction part

  1. The law of electromagnetic induction

    Directory of Open Access Journals (Sweden)

    V.J. Kutkovetskyy

    2014-09-01

    Full Text Available Mathematical models of the electromagnetic induction law which do not take into account Faraday’s restrictions are not in full accordance with the physical phenomenon and so they are not laws. Their incomplete correspondence with real devices results in such "paradoxes" as unlimited magnetic field of unipolar generators, infinite sizes of inductors for DC and AC machines modeled, and so on.

  2. Analyzing high school students’ reasoning about electromagnetic induction

    Directory of Open Access Journals (Sweden)

    Katarina Jelicic

    2017-02-01

    Full Text Available Electromagnetic induction is an important, yet complex, physics topic that is a part of Croatian high school curriculum. Nine Croatian high school students of different abilities in physics were interviewed using six demonstration experiments from electromagnetism (three of them concerned the topic of electromagnetic induction. Students were asked to observe, describe, and explain the experiments. The analysis of students’ explanations indicated the existence of many conceptual and reasoning difficulties with the basic concepts of electromagnetism, and especially with recognizing and explaining the phenomenon of electromagnetic induction. Three student mental models of electromagnetic induction, formed during the interviews, which reoccurred among students, are described and analyzed within the knowledge-in-pieces framework.

  3. Physic basis of electromagnetic induction low

    Directory of Open Access Journals (Sweden)

    V.J. Kutkovetskyy

    2015-03-01

    Full Text Available The statement on the macro level of EMF dependence on change in magnetic flux in time wrong reflects the physical phenomenon of electromagnetic induction low by Faraday, because EMF can be inducted if the magnetic flux of the circuit does not change. Changing magnetic flux of the circuit when the electromotive force arises is only a result of crossing the magnetic field lines by conductor and is an exception, which applies only to certain classes of electric machines.

  4. Combined Approach for Solving the Electromagnetic Induction ...

    African Journals Online (AJOL)

    Nafiisah

    approaches to the reconstruction problem: the pixel-based approach and the parameter-based approach. This paper describes how both approaches may be combined for a more systematic reconstruction. Keywords: Electromagnetic induction, inverse problem, image reconstruction. *For correspondences and reprints ...

  5. Combined Approach for Solving the Electromagnetic Induction ...

    African Journals Online (AJOL)

    Inverse electromagnetic induction is an imaging technique for reconstructing the conductivity and permeability distributions in a region of interest from measurements of impedance made at its boundary. In general, there are two approaches to the reconstruction problem: the pixel-based approach and the parameter-based ...

  6. Electromagnetic segregation of cast parts

    Science.gov (United States)

    Langejurgen, M.; Nacke, B.

    2007-06-01

    The Electromagnetic Induced Segregation (EIS) of cast parts is an innovative technology for diecasting aluminium alloys. Using numerical simulation, an inductor system has been developed to produce a primary silicon concentration gradient during casting. The report shows the advantages of numerical simulation in research and development. A suitable inductor has been designed and its electromagnetic field optimized for the EIS. The numerical model is 2D for geometries with cylindrical symmetry and 3D for non-symmetric products. The inductor system is implemented in a pilot installation. With the metallurgical results, the interaction between the electromagnetic field and the location of primary silicon is investigated. Figs 7, Refs 1.

  7. Penetrating power of resonant electromagnetic induction imaging

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    Roberta Guilizzoni

    2016-09-01

    Full Text Available The possibility of revealing the presence and identifying the nature of conductive targets is of central interest in many fields, including security, medicine, industry, archaeology and geophysics. In many applications, these targets are shielded by external materials and thus cannot be directly accessed. Hence, interrogation techniques are required that allow penetration through the shielding materials, in order for the target to be identified. Electromagnetic interrogation techniques represent a powerful solution to this challenge, as they enable penetration through conductive shields. In this work, we demonstrate the power of resonant electromagnetic induction imaging to penetrate through metallic shields (1.5-mm-thick and image targets (having conductivities σ ranging from 0.54 to 59.77 MSm−1 concealed behind them.

  8. University Students' Understanding of Electromagnetic Induction

    Science.gov (United States)

    Guisasola, Jenaro; Almudi, Jose M.; Zuza, Kristina

    2013-11-01

    This study examined engineering and physical science students' understanding of the electromagnetic induction (EMI) phenomena. It is assumed that significant knowledge of the EMI theory is a basic prerequisite when students have to think about electromagnetic phenomena. To analyse students' conceptions, we have taken into account the fact that individuals build mental representations to help them understand how a physical system works. Individuals use these representations to explain reality, depending on the context and the contents involved. Therefore, we have designed a questionnaire with an emphasis on explanations and an interview, so as to analyse students' reasoning. We found that most of the students failed to distinguish between macroscopic levels described in terms of fields and microscopic levels described in terms of the actions of fields. It is concluded that although the questionnaire and interviews involved a limited range of phenomena, the identified explanations fall into three main categories that can provide information for curriculum development by identifying the strengths and weaknesses of students' conceptions.

  9. On electromagnetic induction in electric conductors

    CERN Document Server

    Korolev, Alexander I

    2013-01-01

    Experimental validation of the Faraday's law of electromagnetic induction (EMI) is performed when an electromotive force is generated in thin copper turns, located inside a large magnetic coil. It has been established that the electromotive force (emf) value should be dependent not only on changes of the magnetic induction flux through a turn and on symmetry of its crossing by magnetic power lines also. The law of EMI is applicable in sufficient approximation in case of the changes of the magnetic field near the turn are symmetrical. Experimental study of the induced emf in arcs and a direct section of the conductor placed into the variable field has been carried out. Linear dependence of the induced emf on the length of the arc has been ascertained in case of the magnetic field distribution symmetry about it. Influence of the magnetic field symmetry on the induced emf in the arc has been observed. The curve of the induced emf in the direct section over period of current pulse is similar to this one for the t...

  10. Investigating Electromagnetic Induction through a Microcomputer-Based Laboratory.

    Science.gov (United States)

    Trumper, Ricardo; Gelbman, Moshe

    2000-01-01

    Describes a microcomputer-based laboratory experiment designed for high school students that very accurately analyzes Faraday's law of electromagnetic induction, addressing each variable separately while the others are kept constant. (Author/CCM)

  11. Model of electrical activity in cardiac tissue under electromagnetic induction.

    Science.gov (United States)

    Wu, Fuqiang; Wang, Chunni; Xu, Ying; Ma, Jun

    2016-12-23

    Complex electrical activities in cardiac tissue can set up time-varying electromagnetic field. Magnetic flux is introduced into the Fitzhugh-Nagumo model to describe the effect of electromagnetic induction, and then memristor is used to realize the feedback of magnetic flux on the membrane potential in cardiac tissue. It is found that a spiral wave can be triggered and developed by setting specific initials in the media, that is to say, the media still support the survival of standing spiral waves under electromagnetic induction. Furthermore, electromagnetic radiation is considered on this model as external stimuli, it is found that spiral waves encounter breakup and turbulent electrical activities are observed, and it can give guidance to understand the occurrence of sudden heart disorder subjected to heavily electromagnetic radiation.

  12. Electromagnetic induction moisture measurement system acceptance test report

    Energy Technology Data Exchange (ETDEWEB)

    Vargo, G.J.

    1996-10-07

    This document presents the results of the acceptance test for the hardware and software that was developed to operate the ElectroMagnetic Induction (EMI) moisture measurement system to be used for in-tank moisture measurements. This document satisfies EP 4.1, ``Design Verification Requirements``.

  13. ASPECTS REGARDING THE ELECTROTHERMAL HEATING THROUGH ELECTROMAGNETIC INDUCTION

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    Teodor LEUCA

    2009-05-01

    Full Text Available The paper present the numerical modeling of the electromagnetic phenomena coupled with the thermic ones when processing the semi-finished products made up of non-ferrous alloy, through electromagnetic induction with the purpose to obtain a homogenous heating of the pieces in the shortest time. Maxwell’s equations that describe the heating process through induction, show that the important quantity, basically important to determine the eddy currents induced in the piece, is the intensity of the magnetic field, resulting the electromagnetic losses, due to their transformation in thermic energy. So far the results of the experiments have show that the intensity of the magnetic field considering a long inductor is more intense in the center of the inductor and weaker at its extremes. The purpose of the numerical modeling is to render solution to homogenize the intensity of the magnetic field according to the geometry of the inductor.

  14. Innovation for soil studies with electromagnetic induction techniques

    Science.gov (United States)

    Aditama, Iqbal F.; Widodo, Setiawan, Tedy; Bijaksana, Satria; Sanny, Teuku A.

    2017-07-01

    Electromagnetic methods for soil research have been applied in the worldwide over the decades. In particular Electromagnetic induction (EMI) techniques have been developed to provide more accurately soil maps. Present EMI methods can identify, characterize, and map spatially-varying soil types and properties offers better than traditional methods. In the future, the EMI techniques will be integrated with agricultural machinery and will be more effective to mapping of both lateral and vertical variations in soil properties. With that advantages, the systems should be utilized in precision agriculture more often in Indonesia. In addition, forward modelling also included in this research as a survey design tool before the outset of field campaign.

  15. Instability in electromagnetically driven flows Part II

    CERN Document Server

    Imazio, Paola Rodriguez

    2016-01-01

    In a previous paper, we have reported numerical simulations of the MHD flow driven by a travelling magnetic field (TMF) in an annular channel, at low Reynolds number. It was shown that the stalling of such induction pump is strongly related to magnetic flux expulsion. In the present article, we show that for larger hydrodynamic Reynolds number, and with more realistic boundary conditions, this instability takes the form of a large axisymmetric vortex flow in the (r,z)-plane, in which the fluid is locally pumped in the direction opposite to the one of the magnetic field. Close to the marginal stability of this vortex flow, a low-frequency pulsation is generated. Finally, these results are compared to theoretical predictions and are discussed within the framework of experimental annular linear induction electromagnetic pumps.

  16. Electromagnetic-induction logging to monitor changing chloride concentrations.

    Science.gov (United States)

    Metzger, Loren F; Izbicki, John A

    2013-01-01

    Water from the San Joaquin Delta, having chloride concentrations up to 3590 mg/L, has intruded fresh water aquifers underlying Stockton, California. Changes in chloride concentrations at depth within these aquifers were evaluated using sequential electromagnetic (EM) induction logs collected during 2004 through 2007 at seven multiple-well sites as deep as 268 m. Sequential EM logging is useful for identifying changes in groundwater quality through polyvinyl chloride-cased wells in intervals not screened by wells. These unscreened intervals represent more than 90% of the aquifer at the sites studied. Sequential EM logging suggested degrading groundwater quality in numerous thin intervals, typically between 1 and 7 m in thickness, especially in the northern part of the study area. Some of these intervals were unscreened by wells, and would not have been identified by traditional groundwater sample collection. Sequential logging also identified intervals with improving water quality-possibly due to groundwater management practices that have limited pumping and promoted artificial recharge. EM resistivity was correlated with chloride concentrations in sampled wells and in water from core material. Natural gamma log data were used to account for the effect of aquifer lithology on EM resistivity. Results of this study show that a sequential EM logging is useful for identifying and monitoring the movement of high-chloride water, having lower salinities and chloride concentrations than sea water, in aquifer intervals not screened by wells, and that increases in chloride in water from wells in the area are consistent with high-chloride water originating from the San Joaquin Delta rather than from the underlying saline aquifer. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

  17. Design and test of a simple fast electromagnetic inductive gas valve for planar pulsed inductive plasma thruster

    Science.gov (United States)

    Guo, Dawei; Cheng, Mousen; Li, Xiaokang

    2017-10-01

    In support of our planar pulsed inductive plasma thruster research, a fast electromagnetic inductive valve for a gas propellant injection system has been built and tested. A new and important design feature is the use of a conical diaphragm as the action part, which greatly contributes to the virtue of simplicity for adopting the resultant force of the diaphragm deformation as the closing force. An optical transmission technique is adopted to measure the opening and closing characters of the valve while the gas throughput is determined by measuring the pressure change per pulse in a test chamber with a capacitance manometer. The experimental results revealed that the delay time before the valve reaction is less than 40 μs, and the valve pulse width is no longer than 160 μs full width at half maximum. The valve delivers 0-2.5 mg of argon gas per pulse varied by adjusting the drive voltage and gas pressure.

  18. Analysis of Arguments Constructed by First-Year Engineering Students Addressing Electromagnetic Induction Problems

    Science.gov (United States)

    Almudi, Jose Manuel; Ceberio, Mikel

    2015-01-01

    This study explored the quality of arguments used by first-year engineering university students enrolled in a traditional physics course dealing with electromagnetic induction and related problem solving where they had to assess whether the electromagnetic induction phenomenon would occur. Their conclusions were analyzed for the relevance of the…

  19. EMC of Electrical Systems - Electromagnetic Coupling ( Part II

    Directory of Open Access Journals (Sweden)

    KOVACOVA, I.

    2007-04-01

    Full Text Available The paper deals with the general analysis of one part of the electromagnetic compatibility (EMC problem - the electromagnetic coupling applied in the field of power electrical systems. The verification simulation analyses and practical measurements of the electromagnetic coupling, which are confirming the correctness of results obtained from theoretical analyses (part I., are presented in part II. So they can be used for predictive stating of EMC quality of individual new electrotechnical products.

  20. Summary of sensor evaluation for the Fusion ELectromagnetic Induction eXperiment (FELIX)

    Energy Technology Data Exchange (ETDEWEB)

    Knott, M.J.

    1982-08-01

    As part of the First Wall/Blanket/Shield Engineering Test Program, a test bed called FELIX (Fusion ELectromagnetic Induction eXperiment) is now under construction at ANL. Its purpose will be to test, evaluate, and develop computer codes for the prediction of electromagnetically induced phenomenon in a magnetic environment modeling that of a fusion reaction. Crucial to this process is the sensing and recording of the various induced effects. Sensor evaluation for FELIX has reached the point where most sensor types have been evaluated and preliminary decisions are being made as to type and quantity for the initial FELIX experiments. These early experiments, the first, flat plate experiment in particular, will be aimed at testing the sensors as well as the pertinent theories involved. The reason for these evaluations, decisions, and proof tests is the harsh electrical and magnetic environment that FELIX presents.

  1. Using computer simulations to facilitate conceptual understanding of electromagnetic induction

    Science.gov (United States)

    Lee, Yu-Fen

    This study investigated the use of computer simulations to facilitate conceptual understanding in physics. The use of computer simulations in the present study was grounded in a conceptual framework drawn from findings related to the use of computer simulations in physics education. To achieve the goal of effective utilization of computers for physics education, I first reviewed studies pertaining to computer simulations in physics education categorized by three different learning frameworks and studies comparing the effects of different simulation environments. My intent was to identify the learning context and factors for successful use of computer simulations in past studies and to learn from the studies which did not obtain a significant result. Based on the analysis of reviewed literature, I proposed effective approaches to integrate computer simulations in physics education. These approaches are consistent with well established education principles such as those suggested by How People Learn (Bransford, Brown, Cocking, Donovan, & Pellegrino, 2000). The research based approaches to integrated computer simulations in physics education form a learning framework called Concept Learning with Computer Simulations (CLCS) in the current study. The second component of this study was to examine the CLCS learning framework empirically. The participants were recruited from a public high school in Beijing, China. All participating students were randomly assigned to two groups, the experimental (CLCS) group and the control (TRAD) group. Research based computer simulations developed by the physics education research group at University of Colorado at Boulder were used to tackle common conceptual difficulties in learning electromagnetic induction. While interacting with computer simulations, CLCS students were asked to answer reflective questions designed to stimulate qualitative reasoning and explanation. After receiving model reasoning online, students were asked to submit

  2. Characterizing subsurface textural properties using electromagnetic induction mapping and geostatistics

    Science.gov (United States)

    Abdu, Hiruy

    Knowledge of the spatial distribution of soil textural properties at the watershed scale is important for understanding spatial patterns of water movement, and in determining soil moisture storage and soil hydraulic transport properties. Capturing the heterogeneous nature of the subsurface without exhaustive and costly sampling presents a significant challenge. Soil scientists and geologists have adapted geophysical methods that measure a surrogate property related to the vital underlying process. Apparent electrical conductivity (ECa) is such a proxy, providing a measure of charge mobility due to application of an electric field, and is highly correlated to the electrical conductivity of the soil solution, clay percentage, and water content. Electromagnetic induction (EMI) provides the possibility of obtaining high resolution images of ECa across a landscape to identify subtle changes in subsurface properties. The aim of this study was to better characterize subsurface textural properties using EMI mapping and geostatistical analysis techniques. The effect of variable temperature environments on EMI instrumental response, and EC a -- depth relationship were first determined. Then a procedure of repeated EMI mapping at varying soil water content was developed and integrated with temporal stability analysis to capture the time invariant properties of spatial soil texture on an agricultural field. In addition, an EMI imaging approach of densely sampling the subsurface of the Reynolds Mountain East watershed was presented using kriging to interpolate, and Sequential Gaussian Simulation to estimate the uncertainty in the maps. Due to the relative time-invariant characteristics of textural properties, it was possible to correlate clay samples collected over three seasons to ECa data of one mapping event. Kriging methods [ordinary kriging (OK), cokriging (CK), and regression kriging (RK)] were then used to integrate various levels of information (clay percentage, ECa

  3. OPTIMAL CONTROL OF A NONLINEAR COUPLED ELECTROMAGNETIC INDUCTION HEATING SYSTEM WITH POINTWISE STATE CONSTRAINTS

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    Irwin Yousept

    2010-07-01

    Full Text Available An optimal control problem arising in the context of 3D electromagnetic induction heating is investigated. The state equation is given by a quasilinear stationary heat equation coupled with a semilinear time harmonic eddy current equation. The temperature-dependent electrical conductivity and the presence of pointwise inequality state-constraints represent the main challenge of the paper. In the first part of the paper, the existence and regularity of the state are addressed. The second part of the paper deals with the analysis of the corresponding linearized equation. Some suffcient conditions are presented which guarantee thesolvability of the linearized system. The final part of the paper is concerned with the optimal control. The aim of the optimization is to find the optimal voltage such that a desired temperature can be achieved optimally. The corresponding first-order necessary optimality condition is presented.

  4. Electromagnetic induction for mapping textural contrasts of mine tailing deposits

    Science.gov (United States)

    Nearing, Grey S.; Tuller, Markus; Jones, Scott B.; Heinse, Robert; Meding, Mercer S.

    2013-02-01

    Mine tailings present an important legacy of past and present ore-extraction activities in the Desert Southwest. Inactive mine tailings have no immediate economic role in current mining operations, yet from an environmental point of view it is important that such deposits are stabilized to prevent mass movement, wind or water erosion, leaching of chemicals such as acid mine drainage, and to reduce visual blight. In the presented study, we assess the potential for inferring textural properties of mine tailing deposits with electromagnetic induction (EMI) mapping as a means of informing efforts to establish vegetation at mine waste sites. EMI measurements of apparent electrical conductivity (ECa) and tailing samples were collected at a mine waste site in Southern Arizona, USA and used to test empirical and theoretical relationships between ECa and physical and mineralogical properties using linear and Gaussian process regression. Sensitivity analyses of a semi-theoretical and a regression model of ECa as a function of tailing properties indicated that volumetric clay fraction in the top 60 cm was a primary influence on bulk electrical conductivity along with water content, conductivity of the soil water and the presence of conductive minerals hematite and pyrite. At this site, latitude and longitude were better predictors of clay content than ECa, and while it was possible to obtain information about the spatial distribution of tailing texture using EMI, simple Kriging of texture data was a more powerful textural mapping technique. We conclude that EMI is a useful tool for mapping tailing texture at waste deposit sites, but due to physical and chemical heterogeneity of tailing deposits, it is necessary to collect more in situ samples than are needed for agricultural applications.

  5. Electromagnetic induction and radiation-induced abnormality of wave propagation in excitable media

    Science.gov (United States)

    Ma, Jun; Wu, Fuqiang; Hayat, Tasawar; Zhou, Ping; Tang, Jun

    2017-11-01

    Continuous wave emitting from sinus node of the heart plays an important role in wave propagating among cardiac tissue, while the heart beating can be terminated when the target wave is broken into turbulent states by electromagnetic radiation. In this investigation, local periodical forcing is applied on the media to induce continuous target wave in the improved cardiac model, which the effect of electromagnetic induction is considered by using magnetic flux, then external electromagnetic radiation is imposed on the media. It is found that target wave propagation can be blocked to stand in a local area and the excitability of media is suppressed to approach quiescent but homogeneous state when electromagnetic radiation is imposed on the media. The sampled time series for membrane potentials decrease to quiescent state due to the electromagnetic radiation. It could accounts for the mechanism of abnormality in heart failure exposed to continuous electromagnetic field.

  6. Integrated design method of MR damper and electromagnetic induction system for structural control

    Science.gov (United States)

    Lee, Heon-Jae; Moon, Seok-Jun; Jung, Hyung-Jo; Huh, Young-Cheol; Jang, Dong-Doo

    2008-03-01

    Magnetorheological (MR) dampers are one of the most advantageous control devices for civil engineering applications to natural hazard mitigation due to many good features such as small power requirement, reliability, and low price to manufacture. To reduce the responses of a structural system by using MR dampers, a control system including a power supply, control algorithm, and sensors is needed. The control system becomes complex, however, when a lot of MR dampers are applied to large-scale civil structures, such as cable-stayed bridges and high-rise buildings. Thus, it is difficult to install and/or maintain the MR damper-based control system. To overcome the above difficulties, a smart passive system was proposed, which is based on an MR damper system. The smart passive system consists of an MR damper and an electromagnetic induction (EMI) system that uses a permanent magnet and a coil. According to the Faraday law of induction, the EMI system that is attached to the MR damper can produce electric energy and the produced energy is applied to the MR damper to vary the damping characteristics of the damper. Thus, the smart passive system does not require any power at all. Besides the output of electric energy is proportional to input loads such as earthquakes, which means the smart passive system has adaptability by itself without any controller or sensors. In this paper, the integrated design method of a large-scale MR damper and Electromagnetic Induction (EMI) system is presented. Since the force of an MR damper is controllable by altering the input current generated from an EMI part, it is necessary to design an MR damper and an EMI part simultaneously. To do this, design parameters of an EMI part consisting of permanent magnet and coil as well as those of an MR damper consisting of a hydraulic-type cylinder and a magnetic circuit that controls the magnetic flux density in a fluid-flow path are considered in the integrated design procedure. As an example, a

  7. An analytic electromagnetic calculation method for performance evolution of doubly fed induction generators for wind turbines

    DEFF Research Database (Denmark)

    Zhang, Wen-juan; Huang, Shou-dao; Chen, Zhe

    2013-01-01

    was established, which consisted of three iterative calculation loops, including magnetic saturation coefficient, electromotive force and total output power. All of the electromagnetic and performance data of DIFG can be calculated conveniently by the established calculation procedure, which can be used......An analytic electromagnetic calculation method for doubly fed induction generator (DFIG) in wind turbine system was presented. Based on the operation principles, steady state equivalent circuit and basic equations of DFIG, the modeling for electromagnetic calculation of DFIG was proposed....... The electromagnetic calculation of DFIG was divided into three steps: the magnetic flux calculation, parameters derivation and performance checks. For each step, the detailed numeric calculation formulas were all derived. Combining the calculation formulas, the whole electromagnetic calculation procedure...

  8. Induction of Cell Activation Processes by Low Frequency Electromagnetic Fields

    OpenAIRE

    Myrtill Simkó

    2004-01-01

    Electromagnetic fields (EMF) such as those from electric power transmission and distribution lines (50/60 Hz) have been associated with increased risk of childhood leukemia, cancer of the nervous system, and lymphomas. Several in vitro studies on EMF effects were performed to clarify the existing controversies, define the risks, and determine the possible mechanisms of adverse effects. In some of these reports, the effects were related to other mechanisms of carcinogenesis. Modification in ce...

  9. Appraisal of electromagnetic induction effects on magnetic pulsation studies

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    B. R. Arora

    Full Text Available The quantification of wave polarization characteristics of ULF waves from the geomagnetic field variations is done under ‘a priori’ assumption that fields of internal induced currents are in-phase with the external inducing fields. Such approximation is invalidated in the regions marked by large lateral conductivity variations that perturb the flow pattern of induced currents. The amplitude and phase changes that these perturbations produce, in the resultant fields at the Earth’s surface, make determination of polarization and phase of the oscillating external signals problematic. In this paper, with the help of a classical Pc5 magnetic pulsation event of 24 March 1991, recorded by dense network of magnetometers in the equatorial belt of Brazil, we document the nature and extent of the possible influence of anomalous induction effects in the wave polarization of ULF waves. The presence of anomalous induction effects at selected sites lead to an over estimation of the equatorial enhancement at pulsation period and also suggest changes in the azimuth of ULF waves as they propagate through the equatorial electrojet. Through numerical calculations, it is shown that anomalous horizontal fields, that result from induction in the lateral conductivity distribution in the study region, vary in magnitude and phase with the polarization of external source field. Essentially, the induction response is also a function of the period of external inducing source field. It is further shown that when anomalous induction fields corresponding to the magnitude and polarization of the 24 March 1991 pulsation event are eliminated from observed fields, corrected amplitude in the X and Y horizontal components allows for true characterisation of ULF wave parameters.

    Key words. Geomagnetism and paleomagnetism (geomagnetic induction – Ionosphere (equatorial ionosphere – Magnetospheric physics (magnetosphere-ionosphere interactions

  10. Division of the momentum of electromagnetic waves in linear media into electromagnetic and material parts.

    Science.gov (United States)

    Saldanha, Pablo L

    2010-02-01

    It is proposed a natural and consistent division of the momentum of electromagnetic waves in linear, non-dispersive and non-absorptive dielectric and magnetic media into material and electromagnetic parts. The material part is calculated using directly the Lorentz force law and the electromagnetic momentum density has the form epsilon(0)E x B, without an explicit dependence on the properties of the media. The consistency of the treatment is verified through the obtention of a correct momentum balance equation in many examples and showing the compatibility of the division with the Einstein's theory of relativity by the use of a gedanken experiment. An experimental prediction for the radiation pressure on mirrors immersed in linear dielectric and magnetic media is also made.

  11. Introduction to the special section ‘Applications of electromagnetic induction to digital soil mapping’

    Science.gov (United States)

    Use of electromagnetic induction (EMI) instruments has increased as a tool to map soils because it provides a means of locating suitable sampling sites that provide the basis for mapping the spatial variability of various soil properties either directly or indirectly measured with EMI, including sa...

  12. Effects of Physical Models and Simulations to Understand Daily Life Applications of Electromagnetic Induction

    Science.gov (United States)

    Tural, Güner; Tarakçi, Demet

    2017-01-01

    Background: One of the topics students have difficulties in understanding is electromagnetic induction. Active learning methods instead of traditional learning method may be able to help facilitate students' understanding such topics more effectively. Purpose: The study investigated the effectiveness of physical models and simulations on students'…

  13. Effects of Gender and Collaborative Learning Approach on Students' Conceptual Understanding of Electromagnetic Induction

    Science.gov (United States)

    Adolphus, Telima; Omeodu, Doris

    The study investigates the effect of gender and collaborative learning approach on students' conceptual understanding of electromagnetic induction in Secondary Schools in Nigeria. Three research questions and 2 hypotheses were formulated to guide the research. The research design adopted for this study is the quasi-experimental design. In…

  14. Electrical Activity in a Time-Delay Four-Variable Neuron Model under Electromagnetic Induction

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    Keming Tang

    2017-11-01

    Full Text Available To investigate the effect of electromagnetic induction on the electrical activity of neuron, the variable for magnetic flow is used to improve Hindmarsh–Rose neuron model. Simultaneously, due to the existence of time-delay when signals are propagated between neurons or even in one neuron, it is important to study the role of time-delay in regulating the electrical activity of the neuron. For this end, a four-variable neuron model is proposed to investigate the effects of electromagnetic induction and time-delay. Simulation results suggest that the proposed neuron model can show multiple modes of electrical activity, which is dependent on the time-delay and external forcing current. It means that suitable discharge mode can be obtained by selecting the time-delay or external forcing current, which could be helpful for further investigation of electromagnetic radiation on biological neuronal system.

  15. Enhanced UXO Discrimination Using Frequency Domain Electromagnetic Induction

    Science.gov (United States)

    2010-05-01

    Geophex Ltd. I.J. Won, Alex Oren, Frank Funak, and Bill San Filipo were responsible for the development of the EMI sensor technology on which the GEMTADS...Induction,” ESTCP MM-0033 Final Report, submitted May, 2007. H. Nelson, D. Steinhurst, B. Barrow, T. Bell, N. Khadr, W. San Filipo , I. Won. 9. “Moving

  16. Buried explosive hazard characterization using advanced magnetic and electromagnetic induction sensors

    Science.gov (United States)

    Miller, Jonathan S.; Schultz, Gregory; Shah, Vishal

    2013-06-01

    Advanced electromagnetic induction arrays that feature high sensitivity wideband magnetic field and electromagnetic induction receivers provide significant capability enhancement to landmine, unexploded ordnance, and buried explosives detection applications. Specifically, arrays that are easily and quickly configured for integration with a variety of ground vehicles and mobile platforms offer improved safety and efficiency to personnel conducting detection operations including route clearance, explosive ordnance disposal, and humanitarian demining missions. We present experimental results for explosives detection sensor concepts that incorporate both magnetic and electromagnetic modalities. Key technology components include a multi-frequency continuous wave EMI transmitter, multi-axis induction coil receivers, and a high sensitivity chip scale atomic magnetometer. The use of multi-frequency transmitters provides excitation of metal encased threats as well as low conductivity non-metallic explosive constituents. The integration of a radio frequency tunable atomic magnetometer receiver adds increased sensitivity to lower frequency components of the electromagnetic response. This added sensitivity provides greater capability for detecting deeply buried targets. We evaluate the requirements for incorporating these sensor modalities in forward mounted ground vehicle operations. Specifically, the ability to detect target features in near real-time is critical to non-overpass modes. We consider the requirements for incorporating these sensor technologies in a system that enables detection of a broad range of explosive threats that include both metallic and non-metallic components.

  17. Numerical simulation of induction hardening of a cylindrical part based on multi-physics coupling

    Science.gov (United States)

    Tong, Daming; Gu, Jianfeng; Totten, George Edward

    2017-04-01

    An induction hardening process was simulated based on an electromagnetic-thermal-transformation coupled numerical model. Calculation of the microstructure fraction was introduced using a coupled electromagnetic-thermal field during heating and the temperature field of the subsequent cooling process. The isoconversional method was used to formulate the austenitization process during heating, model parameters were determined by continuous heating dilatometric curves, and JMAK and K-M equations were adopted to calculate the fraction of new phases formed during cooling. The temperature and microstructure evolution in a cylindrical part of JIS-SCM440 steel were simulated during the induction hardening process and the simulated temperature and final microstructure distribution fit well with experimental data. Simulation results also showed that the free cooling prior to spray quenching could be optimized to decrease the temperature gradient in the surface layer to avoid decomposition of austenite into non-martensite microstructure.

  18. Research on Design of Plate-type Electromagnetic Coupler in Underwater Inductive Power Transmission

    Directory of Open Access Journals (Sweden)

    Qu Li-yan

    2015-01-01

    Full Text Available Magnetic coupler has a good application in the field of underwater sensor. Magnetic coupler at work, interference by underwater complex situation, stability and efficiency of charging device of the gap is larger fluctuations. The traditional electromagnetic coupling is charging for the stability of the clearance to demand higher. Charging for underwater, as a result of the existence of ocean currents, electromagnetic coupling clearance may not remain very stable. When there is deviation gap, a larger electromagnetic coupling performance deviation. On this particular problem, it puts forward the design method of a new type of plate type electromagnetic coupling. First of all, the leakage inductance of the finite element method to calculate system and excitation inductance, establish electromagnetic coupler with compensation capacitor equivalent circuit, and the primary circuit and secondary circuit was designed. On the basis, the voltage gain and efficiency of the system are carrying on the theoretical derivation and calculation. The simulation experimental results show that the magnetic coupler has a stable voltage gain and charging efficiency, when the partial core within 10 mm, voltage gain remains steady at 5.8%, efficiency remain at around 90%.

  19. Radial electromagnetic force calculation of induction motor based on multi-loop theory

    Directory of Open Access Journals (Sweden)

    HE Haibo

    2017-12-01

    Full Text Available [Objectives] In order to study the vibration and noise of induction motors, a method of radial electromagnetic force calculation is established on the basis of the multi-loop model.[Methods] Based on the method of calculating air-gap magneto motive force according to stator and rotor fundamental wave current, the analytic formulas are deduced for calculating the air-gap magneto motive force and radial electromagnetic force generated in accordance with any stator winding and rotor conducting bar current. The multi-loop theory and calculation method for the electromagnetic parameters of a motor are introduced, and a dynamic simulation model of an induction motor built to achieve the current of the stator winding and rotor conducting bars, and obtain the calculation formula of radial electromagnetic force. The radial electromagnetic force and vibration are then estimated.[Results] The experimental results indicate that the vibration acceleration frequency and amplitude of the motor are consistent with the experimental results.[Conclusions] The results and calculation method can support the low noise design of converters.

  20. Induction of Cell Activation Processes by Low Frequency Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    Myrtill Simkó

    2004-01-01

    Full Text Available Electromagnetic fields (EMF such as those from electric power transmission and distribution lines (50/60 Hz have been associated with increased risk of childhood leukemia, cancer of the nervous system, and lymphomas. Several in vitro studies on EMF effects were performed to clarify the existing controversies, define the risks, and determine the possible mechanisms of adverse effects. In some of these reports, the effects were related to other mechanisms of carcinogenesis. Modification in cell proliferation was observed after EMF exposure and a few reports on cytotoxic effects have also been published. This limited review gives an overview of the current results of scientific research regarding in vitro studies on the effects of power line frequency EMF, but also cell biological mechanisms and their potential involvement in genotoxicity and cytotoxicity are discussed. Cell cycle control and signal transduction processes are included to elucidate the biochemical background of possible interactions. Exposure to EMF has been also linked to the incidence of leukemia and other tumors in some epidemiological studies and is considered as “possibly carcinogenic to humans”, but there is no well-established biological mechanism that explains such a relation. Furthermore, EMF is also shown as a stimulus for immune relevant cells (e.g., macrophages to release free radicals. It is known that chronic activation of macrophages is associated with the onset of phagocytosis and leads to increased formation of reactive oxygen species, which themselves may cause DNA damage and are suggested to lead to carcinogenesis. To demonstrate a possible interaction between EMF and cellular systems, we present a mechanistic model describing cell activation as a major importance for cellular response.

  1. Electromagnetic induction sounding and 3D laser imaging in support of a Mars methane analogue mission

    Science.gov (United States)

    Boivin, A.; Lai, P.; Samson, C.; Cloutis, E.; Holladay, S.; Monteiro Santos, F. A.

    2013-07-01

    The Mars Methane Analogue Mission simulates a micro-rover mission whose purpose is to detect, analyze, and determine the source of methane emissions on the planet's surface. As part of this project, both an electromagnetic induction sounder (EMIS) and a high-resolution triangulation-based 3D laser scanner were tested at the Jeffrey open-pit asbestos mine to identify and characterize geological environments favourable to the occurrence of methane. The presence of serpentinite in the form of chrysotile (asbestos), magnesium carbonate, and iron oxyhydroxides make the mine a likely location for methane production. The EMIS clearly delineated the contacts between the two geological units found at the mine, peridotite and slate, which are separated by a shear zone. Both the peridotite and slate units have low and uniform apparent electrical conductivity and magnetic susceptibility, while the shear zone has much higher conductivity and susceptibility, with greater variability. The EMIS data were inverted and the resulting model captured lateral conductivity variations through the different bedrock geological units buried beneath a gravel road. The 3D point cloud data acquired by the laser scanner were fitted with triangular meshes where steeply dipping triangles were plotted in dark grey to accentuate discontinuities. The resulting images were further processed using Sobel edge detection to highlight networks of fractures which are potential pathways for methane seepage.

  2. Magnetic and Electromagnetic Induction Effects in the Annual Means of Geomagnetic Elements

    Science.gov (United States)

    Demetrescu, Crisan; Andreescu, Maria

    1992-01-01

    The solar-cycle related (SC) variation in the annual means of the horizontal and vertical components of the geomagnetic field at European observatories is used to infer information on the magnetic and electric properties of the interior, characteristic of the observatory location, by identifying and analyzing the magnetic induction component and respectively the electromagnetic induction component of the SC variation. The obtained results and the method can be used to better constrain the anomaly bias in main field modelling and to improve the reliability of secular variation models beyond the time interval covered by data.

  3. NUMERICAL MODELING OF THE ELECTROMAGNETIC FIELD WITHIN THE INDUCTION HARDENING OF INNER CYLINDRICAL SURFACES

    Directory of Open Access Journals (Sweden)

    C. O. MOLNAR

    2008-05-01

    Full Text Available The paper presents the numerical modeling ofelectromagnetic field within the induction hardening ofinner cylindrical surface. The numerical computation hasbeen done by means of finite element method in order tosolve the coupled electromagnetic and thermal fieldquestion. The obtained results provide informationregarding the heating process taking into account therelative movement between the inductor and workpiece,the over heating of thin layers, the geometricalconfiguration of the inductor as well the technologicalrequirements correlated with electrical parameters andrepresents an active tool to setup the induction heatingequipment in order to get best results during hardeningprocess .

  4. Usefulness of electromagnetic induction type of force transducer and actuator for myofibril mechanics.

    Science.gov (United States)

    Kimura, Kazushige; Abe, Takahiro; Phan, Kien Nguyen; Kobayashi, Takakazu

    2012-01-01

    A high performance device for measuring force and length change during myofibril contraction is fabricated. The principle of a device depends on the law of electromagnetic induction. Homogenized myofibrils were attached between two wires exposed in the uniform magnetic field by silicon adhesive under an inverted microscope. The purpose of this study is to examine performance whether the electromagnetic induction type of device actually works. Sensitivity and time resolution of force transducer was 50nN and 1ms respectively. Working displacement and time resolution of actuator as length transducer was 1-20 µm and 1.2 ms. We confirmed the performance of the device by showing appropriate force response to changes in length during myofibrils contraction, and possibility of application of the device to myofibril mechanics is discussed.

  5. Carbon fiber and void detection using high-frequency electromagnetic induction techniques

    Science.gov (United States)

    Barrowes, Benjamin E.; Sigman, John B.; Wang, YinLin; O'Neill, Kevin A.; Shubitidze, Fridon; Simms, Janet; Bennett, Hollis J.; Yule, Donald E.

    2016-05-01

    Ultrawide band electromagnetic induction (EMI) instruments have been traditionally used to detect high electric conductivity discrete targets such as metal unexploded ordnance. The frequencies used for this EMI regime have typically been less than 100 kHz. To detect intermediate conductivity objects like carbon fiber, even less conductive saturated salts, and even voids embedded in conducting soils, higher frequencies up to the low megahertz range are required in order to capture characteristic responses. To predict EMI phenomena at frequencies up to 15 MHz, we first modeled the response of intermediate conductivity targets using a rigorous, first-principles approach, the Method of Auxiliary Sources. A newly fabricated benchtop high-frequency electromagnetic induction instrument produced EMI data at frequencies up to that same high limit. Modeled and measured characteristic relaxation signatures compare favorably and indicate new sensing possibilities in a variety of scenarios.

  6. Electromagnetic compatibility and safety design of a patient compliance-free, inductive implant charger.

    Science.gov (United States)

    Theodoridis, Michael P; Mollov, Stefan V

    2014-10-01

    This article presents the design of a domestic, radiofrequency induction charger for implants toward compliance with the Federal Communications Commission safety and electromagnetic compatibility regulations. The suggested arrangement does not impose any patient compliance requirements other than the use of a designated bed for night sleep, and therefore can find a domestic use. The method can be applied to a number of applications; a rechargeable pacemaker is considered as a case study. The presented work has proven that it is possible to realize a fully compliant inductive charging system with minimal patient interaction, and has generated important information for consideration by the designers of inductive charging systems. Experimental results have verified the validity of the theoretical findings.

  7. Detailed predictive mapping of acid sulfate soil occurrence using electromagnetic induction data

    DEFF Research Database (Denmark)

    Beucher, Amélie; Boman, A; Mattbäck, S

    Acid sulfate soils are often called the nastiest soils in the world (Dent & Pons 1995). Releasing a toxic combination of acidity and metals into the recipient watercourses and estuaries, these soils represent a crucial environmental problem. Moreover, these soils can have a considerable economic.......e. soil sampling and subsequent pH measurements) has typically been used for acid sulfate soils. Nonetheless, spatial modelling techniques have recently been assessed, demonstrating promising results at catchment or regional extent (Beucher et al. 2014, 2015). Furthermore, electromagnetic induction data...... machine learning approaches will be assessed using soil and environmental data, in particular proximal sensing electromagnetic data collected from a DUALEM. The measurements of the apparent soil electrical conductivity can provide data on the spatial variation of soil salinity, which is associated...

  8. Application of Electromagnetic Induction to Monitor Changes in Soil Electrical Conductivity Profiles in Arid Agriculture

    KAUST Repository

    Jadoon, K.Z.

    2015-09-06

    In this research, multi-configuration electromagnetic induction (EMI) measurements were conducted in a corn field to estimate variation in soil electrical conductivity profiles in the roots zone. Electromagnetic forward model based on the full solution of Maxwell\\'s equation was used to simulate the apparent electrical conductivity measured with EMI system (the CMD mini-Explorer). Joint inversion of multi-configuration EMI measurements were performed to estimate the vertical soil electrical conductivity profiles. The inversion minimizes the misfit between the measured and modeled soil apparent electrical conductivity by DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm, which is based on Bayesain approach. Results indicate that soil electrical conductivity profiles have low values close to the corn plants, which indicates loss of soil moisture due to the root water uptake. These results offer valuable insights into future potential and emerging challenges in the development of joint analysis of multi-configuration EMI measurements to retrieve effective soil electrical conductivity profiles.

  9. Electromagnetic forward and inverse problems of non-rotating magnetoacoustic tomography with magnetic induction.

    Science.gov (United States)

    Zhang, Yang; Liu, Guoqiang; Tao, Chunjing; Wang, Hao; He, Wenjing

    2009-01-01

    The analysis of electromagnetic forward and inverse problems is very important in the process of image reconstruction for magnetoacoustic tomography with magnetic induction (MAT-MI). A new analysis method was introduced in this paper. It breaks through some illogical supposes that the existing methods applied and can improve the spatial resolution of the image availably. Besides it can avoid rotating the static magnetic field which is very difficult to come true in application, therefore the development of MAT-MI technique can be promoted greatly. To test the validity of the new method, two test models were analyzed, and the availability of the method was demonstrated.

  10. Detailed predictive mapping of acid sulfate soil occurrence using electromagnetic induction data

    DEFF Research Database (Denmark)

    Beucher, Amélie; Boman, A; Mattbäck, S

    Acid sulfate soils are often called the nastiest soils in the world (Dent & Pons, 1995). Releasing a toxic combination of acidity and metals into the recipient watercourses and estuaries, these soils represent a crucial environmental problem. Moreover, these soils can have a considerable economic......).Since acid sulfate soils contain large amounts of soluble salts, they yield strong electromagnetic (EM) anomalies, appearing as diffuse and round-shaped high electrical conductivity (EC) areas. EM induction data collected from an EM38 proximal sensor hence enabled the refined mapping of acid sulfate...

  11. Model of the double-rotor induction motor in terms of electromagnetic differential

    Directory of Open Access Journals (Sweden)

    Adamczyk Dominik

    2016-12-01

    Full Text Available The paper presents a concept, a construction, a circuit model and experimental results of the double-rotor induction motor. This type of a motor is to be implemented in the concept of the electromagnetic differential. At the same time it should fulfill the function of differential mechanism and the vehicle drive. One of the motor shafts is coupled to the direction changing mechanical transmission. The windings of the external rotor are powered by slip rings and brushes. The inner rotor has the squirrel-cage windings. The circuit model parameters were calculated based on the 7.5 kW real single-rotor induction motor (2p = 4. Experimental verification of the model was based on comparison between the mentioned single-rotor motor and double-rotor model with the outer rotor blocked. The presented results showed relatively good compliance between the model and real motor.

  12. Electromagnetic receiver with capacitive electrodes and triaxial induction coil for tunnel exploration

    Science.gov (United States)

    Kai, Chen; Sheng, Jin; Wang, Shun

    2017-09-01

    A new type of electromagnetic (EM) receiver has been developed by integrating four capacitive electrodes and a triaxial induction coil with an advanced data logger for tunnel exploration. The new EM receiver can conduct EM observations in tunnels, which is one of the principal goals of surface-tunnel-borehole EM detection for deep ore deposit mapping. The use of capacitive electrodes enables us to record the electrical field (E-field) signals from hard rock surfaces, which are high-resistance terrains. A compact triaxial induction coil integrates three independent induction coils for narrow-tunnel exploration applications. A low-time-drift-error clock source is developed for tunnel applications where GPS signals are unavailable. The three main components of our tunnel EM receiver are: (1) four capacitive electrodes for measuring the E-field signal without digging in hard rock regions; (2) a triaxial induction coil sensor for audio-frequency magnetotelluric and controlled-source audio-frequency magnetotelluric signal measurements; and (3) a data logger that allows us to record five-component MT signals with low noise levels, low time-drift-error for the clock source, and high dynamic range. The proposed tunnel EM receiver was successfully deployed in a mine that exhibited with typical noise characteristics. [Figure not available: see fulltext. Caption: The new EM receiver can conduct EM observations in tunnels, which is one of the principal goals of the surface-tunnel-borehole EM (STBEM) detection for deep ore deposit mapping. The use of a capacitive electrode enables us to record the electrical field (E-field) signals from hard rock surfaces. A compact triaxial induction coil integrated three induction coils, for narrow-tunnel applications.

  13. The application of magnetic gradiometry and electromagnetic induction at a former radioactive waste disposal site.

    Science.gov (United States)

    Rucker, Dale Franklin

    2010-04-01

    A former radioactive waste disposal site is surveyed with two non-intrusive geophysical techniques, including magnetic gradiometry and electromagnetic induction. Data were gathered over the site by towing the geophysical equipment mounted to a non-electrically conductive and non-magnetic fibre-glass cart. Magnetic gradiometry, which detects the location of ferromagnetic material, including iron and steel, was used to map the existence of a previously unknown buried pipeline formerly used in the delivery of liquid waste to a number of surface disposal trenches and concrete vaults. The existence of a possible pipeline is reinforced by historical engineering drawing and photographs. The electromagnetic induction (EMI) technique was used to map areas of high and low electrical conductivity, which coincide with the magnetic gradiometry data. The EMI also provided information on areas of high electrical conductivity unrelated to a pipeline network. Both data sets demonstrate the usefulness of surface geophysical surveillance techniques to minimize the risk of exposure in the event of future remediation efforts.

  14. Vibration control of a cable-stayed bridge using electromagnetic induction based sensor integrated MR dampers

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sang Won [University of Western Ontario, London (Canada); Koo, Jeong Hoi [Miami University, Oxford (United States); Jo, Ji Seong [POSCO, Seongnam (Korea, Republic of)

    2007-06-15

    This paper presents a novel electromagnetic induction (EMI) system integrated in magneto rheological (MR) dampers: The added EMI system converts reciprocal motions of MR damper into electiral energy (electromotive force or emf) according to the Faraday's law of electromagnetic induction. Maximum energy dissipation algorithm (MEDA) is employed to regulate the MR dampers because it strives to simplify a complex design process by employing the Lyapunov's direct approach. The emf signal, produced from the EMI, provides the necessary measurement information (i.e., realtive velocity across the damper) for the MEDA controller. Thus, the EMI acts as a sensor in the proposed MR-EMI system. In order to evaluate the performance and robustness of the MR-EMI sensor system with the MEDA control, this study performed an extensive simulation study using the first generation benchmark cable-stayed bridge. Moreover, it compared the performance and the robustness of proposed system with those of Clipped-Optimal Control (COC) and Sliding Mode Control (SMC), which were previously studied for the benchmark cable-stayed bridge. The results show that the MR-EMI system reduced the vibrations of the bridge structure more than those of COC and SMC and show more robust performance than that of SMC. These results suggest that EMIs can be used cost-effective sensing devices for MR damper control systems without compromising the performance of them.

  15. Research on Stabilization Properties of Inductive-Capacitive Transducers Based on Hybrid Electromagnetic Elements

    Science.gov (United States)

    Konesev, S. G.; Khazieva, R. T.; Kirllov, R. V.; Konev, A. A.

    2017-01-01

    Some electrical consumers (the charge system of storage capacitor, powerful pulse generators, electrothermal systems, gas-discharge lamps, electric ovens, plasma torches) require constant power consumption, while their resistance changes in the limited range. Current stabilization systems (CSS) with inductive-capacitive transducers (ICT) provide constant power, when the load resistance changes over a wide range and increaseы the efficiency of high-power loads’ power supplies. ICT elements are selected according to the maximum load, which leads to exceeding a predetermined value of capacity. The paper suggests carrying load power by the ICT based on multifunction integrated electromagnetic components (MIEC) to reduce the predetermined capacity of ICT elements and CSS weights and dimensions. The authors developed and patented ICT based on MIEC that reduces the CSS weights and dimensions by reducing components number with the possibility of device’s electric energy transformation and resonance frequency changing. An ICT mathematical model was produced. The model determines the width of the load stabilization range. Electromagnetic processes study model was built with the MIEC integral parameters (full inductance of the electrical lead, total capacity, current of electrical lead). It shows independence of the load current from the load resistance for different ways of MIEC connection.

  16. Multi-objective optimization of the induction machine with minimization of audible electromagnetic noise

    Science.gov (United States)

    Le Besnerais, J.; Hecquet, M.; Lanfranchi, V.; Brochet, P.

    2007-08-01

    Induction motors optimal design can involve many variables and objectives, and generally requires to make several trade-offs, especially when including the audible electromagnetic noise criterion beyond the usual performance criteria. Multiobjective optimization techniques based on Pareto optimality are useful to help us finding the most interesting solutions and decide which one(s) to adopt. However, it is not always easy to analyse the Pareto-optimal solutions obtained with such methods, especially when treating more than three objectives, and Pareto fronts may contain more data than we might think. This paper briefly describes an analytical model of the variable-speed squirrel-cage induction machine which computes both its performances and sound power level of electromagnetic origin. The model is then coupled to the Non-dominated Sorting Genetic Algorithm (NSGA-II) in order to perform global optimization with respect to several objectives (e.g. noise level, efficiency and material cost). Finally, an optimization problem is solved and analysed, and some useful visualization tools of the Pareto optimal solutions and their characteristics are presented.

  17. Initial-Value Approach to the Electromagnetic Induction in a~Heterogeneous Sphere

    Science.gov (United States)

    Velímský, J.; Martinec, Z.

    2001-12-01

    We present an initial-value (IV) approach to the forward problem of large-scale electromagnetic induction in a heterogeneous sphere with 3-D conductivity structure, excited by an external source current. The formulation in the time domain is suitable to study the Earth's electromagnetic response to arbitrary variations of the external source currents, in particular to transient signals, which are difficultly treated by the traditional frequency-domain approach. The parabolic partial differential equation of electromagnetic induction is reformulated in the weak sense. The magnetic field is parameterized by vector spherical harmonic functions in lateral coordinates and by piecewise linear finite elements in radial coordinate. A semi-implicit Euler scheme is applied for the time integration. The terms containing the radial conductivity profile are treated implicitly, while the effect of lateral variations is taken explicitly from the previous time step. Conductivity models consisting of multiple homogeneous off-axis nested spheres are used to test the IV method and computer code against the known semi-analytic (SA) solutions for periodic external source signals. The differences between the results of IV and SA solutions can be attributed solely to the numerical errors and diminish as the spatial and temporal resolution is increased. The ability to treat arbitrary external source signals, which is the most important advantage of the IV approach over the frequency-domain methods comes at the cost of two drawbacks. Firstly, an initial magnetic field has to be specified in the whole sphere.Secondly, the common concept of frequency-dependent skin-depth can not be directly employed,because frequency is not introduced at all.

  18. Collection, processing, and quality assurance of time-series electromagnetic-induction log datasets, 1995–2016, south Florida

    Science.gov (United States)

    Prinos, Scott T.; Valderrama, Robert

    2016-12-13

    Time-series electromagnetic-induction log (TSEMIL) datasets are collected from polyvinyl-chloride cased or uncased monitoring wells to evaluate changes in water conductivity over time. TSEMIL datasets consist of a series of individual electromagnetic-induction logs, generally collected at a frequency of once per month or once per year that have been compiled into a dataset by eliminating small uniform offsets in bulk conductivity between logs probably caused by minor variations in calibration. These offsets are removed by selecting a depth at which no changes are apparent from year to year, and by adjusting individual logs to the median of all logs at the selected depth. Generally, the selected depths are within the freshwater saturated part of the aquifer, well below the water table. TSEMIL datasets can be used to monitor changes in water conductivity throughout the full thickness of an aquifer, without the need for long open-interval wells which have, in some instances, allowed vertical water flow within the well bore that has biased water conductivity profiles. The TSEMIL dataset compilation process enhances the ability to identify small differences between logs that were otherwise obscured by the offsets. As a result of TSEMIL dataset compilation, the root mean squared error of the linear regression between bulk conductivity of the electromagnetic-induction log measurements and the chloride concentration of water samples decreased from 17.4 to 1.7 millisiemens per meter in well G–3611 and from 3.7 to 2.2 millisiemens per meter in well G–3609. The primary use of the TSEMIL datasets in south Florida is to detect temporal changes in bulk conductivity associated with saltwater intrusion in the aquifer; however, other commonly observed changes include (1) variations in bulk conductivity near the water table where water saturation of pore spaces might vary and water temperature might be more variable, and (2) dissipation of conductive water in high-porosity rock

  19. Spatial relationship between the productivity of cane sugar and soil electrical conductivity measured by electromagnetic induction

    Science.gov (United States)

    Siqueira, Glecio; Silva, Jucicléia; Bezerra, Joel; Silva, Enio; Montenegro, Abelardo

    2013-04-01

    The cultivation of sugar cane in Brazil occupies a prominent place in national production chain, because the country is the main world producer of sugar and ethanol. Accordingly, studies are needed that allow an integrated production and technified, and especially that estimates of crops are consistent with the actual production of each region. The objective of this study was to determine the spatial relationship between the productivity of cane sugar and soil electrical conductivity measured by electromagnetic induction. The field experiment was conducted at an agricultural research site located in Goiana municipality, Pernambuco State, north-east of Brazil (Latitude 07 ° 34 '25 "S, Longitude 34 ° 55' 39" W). The surface of the studied field is 6.5 ha, and its mean height 8.5 m a.s.l. This site has been under sugarcane (Saccharum officinarum sp.) monoculture during the last 24 years and it was managed burning the straw each year after harvesting, renewal of plantation was performed every 7 years. Studied the field is located 10 km east from Atlantic Ocean and it is representative of the regional landscape lowlands, whose soils are affected by salinity seawater, sugarcane plantations with the main economical activity. Soil was classified an orthic the Podsol. The productivity of cane sugar and electrical conductivity were measured in 90 sampling points. The productivity of cane sugar was determined in each of the sampling points in plots of 9 m2. The Apparent soil electrical conductivity (ECa, mS m-1) was measured with an electromagnetic induction device EM38-DD (Geonics Limited). The equipment consists of two units of measurement, one in a horizontal dipole (ECa-H) to provide effective measurement distance of 1.5 m approximately and other one in vertical dipole (ECa-V) with an effective measurement depth of approximately 0.75 m. Data were analyzed using descriptive statistics and geostatistical tools. The results showed that productivity in the study area

  20. Anomalous directional behaviour of the real parts of the induction arrows in the Eastern Alps: tectonic and palaeogeographic implications

    Directory of Open Access Journals (Sweden)

    P. A. Schnegg

    2001-06-01

    Full Text Available The electromagnetic induction pattern in the Eastern Alps is characterised by a (continuous large-scale zone on which the real parts of the induction arrows show anomalous directional behaviour. This zone extends from the Penninic Domain of Eastern Switzerland (Graubünden probably into the Carpathian ranges. A coarse mesh of a Magnetotelluric (MT and Geomagnetic Deep Sounding (GDS station in the Alps of Graubünden and Valais (Western Switzerland indicates that this electromagnetic anomaly is restricted to the Mesozoic sediments of the North Penninic Bündnerschiefer-facies that begins in Eastern Switzerland and extends towards the east beneath Austroalpine, South Penninic and Southalpine units. Striking similarities in position and arrangement between this zone and the magnetic signature in the Eastern Alps are found. The analysis of the GDS data with the method of the Hypothetical Event Analysis (HEA shows that current channelling affects the electromagnetic fields in this zone and causes the anomalous direction of induction arrows. Based on the combined interpretation of GDS data from the Eastern Alps and West Hungary together with our recent data from Switzerland, the following geological implications are discussed: i a spatial decoupling of induction processes from the upper to the lower crust; ii a lower crustal conductive structure caused by the indentation of the Northern Adriatic promontory or terrane; iii the eastward continuation of the Bündnerschiefer-facies at least to the tectonic window of Rechnitz.

  1. Hardware design of a submerged buoy system based on electromagnetic inductive coupling

    Directory of Open Access Journals (Sweden)

    Song Dalei

    2016-01-01

    Full Text Available This paper mainly introduces the hardware design of a new type of ocean buoy for multi-scale marine dynamic process. The buoy system can collect a number of real-time marine environment data and then transmit all the data back to the landing site through wireless module. The authors mainly designed the hardware circuit of the buoy system, including data collection system, data communication system, data storage system. Due to the buoy system will complete the marine observation work continuously for at least a month, so we add the low power consumption function which can realize the intermittent work for the data collection system. This paper also introduces the electromagnetic induction coupling technology of underwater sensors, the sea surface communication network technology, etc. The system can also extends to the ecological regional anomaly monitoring and the early warning of disaster weather.

  2. Nonlinear electromagnetic fields in 0.5 MHz inductively coupled plasmas

    DEFF Research Database (Denmark)

    Ostrikov, K.N.; Tsakadze, E.L.; Xu, S.

    2003-01-01

    Radial profiles of magnetic fields in the electrostatic (E) and electromagnetic (H) modes of low-frequency (similar to500 kHz) inductively coupled plasmas have been measured using miniature magnetic probes. In the low-power (similar to170 W) E-mode, the magnetic field pattern is purely linear......, with the fundamental frequency harmonics only. After transition to higher-power (similar to1130 W) H-mode, the second-harmonic nonlinear azimuthal magnetic field B-phi(2omega) that is in 4-6 times larger than the fundamental frequency component B-phi(omega), has been observed. A simplified plasma fluid model...... explaining the generation of the second harmonics of the azimuthal magnetic field in the plasma source is proposed. The nonlinear second harmonic poloidal (r-z) rf current generating the azimuthal magnetic field B-phi(2omega) is attributed to nonlinear interactions between the fundamental frequency radial...

  3. Modelling of resonant MEMS magnetic field sensor with electromagnetic induction sensing

    Science.gov (United States)

    Liu, Song; Xu, Huaying; Xu, Dehui; Xiong, Bin

    2017-06-01

    This paper presents an analytical model of resonant MEMS magnetic field sensor with electromagnetic induction sensing. The resonant structure vibrates in square extensional (SE) mode. By analyzing the vibration amplitude and quality factor of the resonant structure, the magnetic field sensitivity as a function of device structure parameters and encapsulation pressure is established. The developed analytical model has been verified by comparing calculated results with experiment results and the deviation between them is only 10.25%, which shows the feasibility of the proposed device model. The model can provide theoretical guidance for further design optimization of the sensor. Moreover, a quantitative study of the magnetic field sensitivity is conducted with respect to the structure parameters and encapsulation pressure based on the proposed model.

  4. Urban soil exploration through multi-receiver electromagnetic induction and stepped-frequency ground penetrating radar.

    Science.gov (United States)

    Van De Vijver, Ellen; Van Meirvenne, Marc; Vandenhaute, Laura; Delefortrie, Samuël; De Smedt, Philippe; Saey, Timothy; Seuntjens, Piet

    2015-07-01

    In environmental assessments, the characterization of urban soils relies heavily on invasive investigation, which is often insufficient to capture their full spatial heterogeneity. Non-invasive geophysical techniques enable rapid collection of high-resolution data and provide a cost-effective alternative to investigate soil in a spatially comprehensive way. This paper presents the results of combining multi-receiver electromagnetic induction and stepped-frequency ground penetrating radar to characterize a former garage site contaminated with petroleum hydrocarbons. The sensor combination showed the ability to identify and accurately locate building remains and a high-density soil layer, thus demonstrating the high potential to investigate anthropogenic disturbances of physical nature. In addition, a correspondence was found between an area of lower electrical conductivity and elevated concentrations of petroleum hydrocarbons, suggesting the potential to detect specific chemical disturbances. We conclude that the sensor combination provides valuable information for preliminary assessment of urban soils.

  5. A physical pattern recognition approach for 2D electromagnetic induction studies

    Directory of Open Access Journals (Sweden)

    D. Patella

    2000-06-01

    Full Text Available We present a new tomographic procedure for the analysis of natural source electromagnetic (EM induction field data collected over any complex 2D buried structure beneath a flat air-earth boundary. The tomography is developed in a pure physical context and the primary goal is the depiction of the space distribution of two occurrence probability functions for the induced electrical charge accumulations on resistivity discontinuities and current channelling inside conductive bodies, respectively. The procedure to obtain tomographic image consists of a scanning operation governed analytically by a set of multiple interference cross-correlations between the observed EM components and the corresponding synthetic components of a pair of elementary charge and dipole. To show the potentiality of the proposed physical tomography, we discuss the results from three 2D synthetic examples.

  6. Modeling of High-Frequency Electromagnetic Effects on an Ironless Inductive Position Sensor

    CERN Document Server

    Danisi, Alessandro; Masi, Alessandro; Perriard, Yves

    2013-01-01

    The ironless inductive position sensor (I2PS) is a five-coil air-cored structure that senses the variation of flux linkage between supply and sense coils and relates it to the linear position of a moving coil. In air-cored structures, the skin and proximity effect can bring substantial variations of the electrical resistance, leading to important deviations from the low-frequency functioning. In this paper, an analysis of the effect of high-frequency phenomena on the I2PS functioning is described. The key-element is the modeling of the resistance as a function of the frequency, which starts from the analytical resolution of Maxwell's equations in the coil's geometry. The analysis is validated by means of experimental measurements on custom sensor coils. The resulting model is integrated with the existing low-frequency analysis and represents a complete tool for the design of an I2PS sensor, framing its electromagnetic behavior.

  7. Application of Induction Heating for Brazing Parts of Solar Collectors

    Directory of Open Access Journals (Sweden)

    Kristína Demianová

    2012-01-01

    Full Text Available This paper reports on the application of induction heating for brazing parts of solar collectors made of Al alloys. The tube-flange joint is a part of the collecting pipe of a solar collector. The main task was to design an induction coil for this type of joint, and to select the optimum brazing parameters. Brazing was performed with AlSi12 brazing alloy, and corrosive and non-corrosive flux types were also applied. The optimum brazing parameters were determined on the basis of testing the fabricated brazed joints by visual inspection, by leakage tests, and by macro- and micro-analysis of the joint boundary. The following conditions can be considered to be the best for brazing Al materials: power 2.69 kW,brazing time 24 s, flux BrazeTec F32/80.

  8. Research on an Automatic Measurement of Impulse Electromagnetic Noise (IV) : Relation of Electromagnetic Induction Noise and Malfunction of Print Circuits

    OpenAIRE

    佐野, 博也; 松本, 史生; サノ, ヒロヤ; マツモト, フミオ; Hiroya, SANO; Fumio, MATUMOTO

    1993-01-01

    Experimental studies were made on electromagnetic susceptibility and malfunction of high speed CMOS digital printed circuit boards (PCB). We measured the induced noise voltage on a printed loop circuit caused by electromagnetic emission from an adjacent digital PCB. Electromagnetic susceptibility of a bus circuit was measured with a TEM cell in frequency range of 10 to 250 MHz. The induced noise increased near the resonance frequency of the circuit. We also measured the amplitude of noise vol...

  9. Promoting Conceptual Development in Physics Teacher Education: Cognitive-Historical Reconstruction of Electromagnetic Induction Law

    Science.gov (United States)

    Mäntylä, Terhi

    2013-06-01

    In teaching physics, the history of physics offers fruitful starting points for designing instruction. I introduce here an approach that uses historical cognitive processes to enhance the conceptual development of pre-service physics teachers' knowledge. It applies a method called cognitive-historical approach, introduced to the cognitive sciences by Nersessian (Cognitive Models of Science. University of Minnesota Press, Minneapolis, pp. 3-45, 1992). The approach combines the analyses of actual scientific practices in the history of science with the analytical tools and theories of contemporary cognitive sciences in order to produce knowledge of how conceptual structures are constructed and changed in science. Hence, the cognitive-historical analysis indirectly produces knowledge about the human cognition. Here, a way to use the cognitive-historical approach for didactical purposes is introduced. In this application, the cognitive processes in the history of physics are combined with current physics knowledge in order to create a cognitive-historical reconstruction of a certain quantity or law for the needs of physics teacher education. A principal aim of developing the approach has been that pre-service physics teachers must know how the physical concepts and laws are or can be formed and justified. As a practical example of the developed approach, a cognitive-historical reconstruction of the electromagnetic induction law was produced. For evaluating the uses of the cognitive-historical reconstruction, a teaching sequence for pre-service physics teachers was conducted. The initial and final reports of twenty-four students were analyzed through a qualitative categorization of students' justifications of knowledge. The results show a conceptual development in the students' explanations and justifications of how the electromagnetic induction law can be formed.

  10. Vito Volterra and his commemoration for the centenary of Faraday's discovery of electromagnetic induction

    CERN Document Server

    Sparavigna, Amelia Carolina

    2016-01-01

    The paper presents a memoir of 1931 written by Vito Volterra on the Italian physicists of the nineteenth century and the researches these scientists made after the discoveries of Michael Faraday on electromagnetism. Here, the memoir entitled "I fisici italiani e le ricerche di Faraday" is translated from Italian. It was written to commemorate the centenary of Faraday's discovery of the electromagnetic induction. Besides being a remarkable article on the history of science, it was also, in a certain extent, a political paper. In fact, in 1931, the same year of the publication of this article, Mussolini imposed a mandatory oath of loyalty to Italian academies. Volterra was one of the very few professors who refused to take this oath of loyalty. Because of the political situation in Italy, Volterra wanted to end his paper sending a message to the scientists of the world, telling that the feeling of admiration and gratitude that in Italy the scientists had towards "the great thinker and British experimentalist" w...

  11. The Electrical Activity of Neurons Subject to Electromagnetic Induction and Gaussian White Noise

    Science.gov (United States)

    Wang, Ya; Ma, Jun; Xu, Ying; Wu, Fuqiang; Zhou, Ping

    Neurons can give appropriate response to external electrical stimuli and the modes in electrical activities can be carefully selected. Most of the neuron models mainly emphasize on the ion channel currents embedded into the membrane and the properties in electrical activities can be produced in the theoretical models. Indeed, some physical effect should be considered during the model setting for neuronal activities. In fact, induced current and the electrical field will cause the membrane potential to change and an exchange of charged ions during the fluctuation of ion concentration in cell. As a result, the effect of electromagnetic induction should be seriously considered. In this paper, magnetic flux is proposed to describe the effect of electromagnetic field, and the memristor is used to realize coupling on membrane by inputting induced current based on consensus of physical unit. Noise is also considered to detect the dynamical response in electrical activities and stochastic resonance, it is found that multiple modes can be selected in the electrical activities and it could be associated with memory effect and self-adaption in neurons.

  12. Joint inversion of multi-configuration electromagnetic induction data to characterize subsurface electrical conductivity

    KAUST Repository

    Jadoon, Khan

    2012-01-01

    Electromagnetic induction (EMI) devices are capable of measuring the cumulative electrical conductivity over a certain depth range. In this study, a numerical experiment has been performed to test a novel join inversion approach for the Geonics EM34 instrument, by considering different coil offsets (10, 20 and 40 m), different coil orientations (vertical and horizontal), and different frequencies (6.4, 1.6 and 0.4 kHz). The subsurface is considered as four-layer model having different conductivities. The global multilevel coordinate search optimization algorithm is sequentially combination with the local optimization algorithm to minimize the misfit between the measured and modeled data. The layer conductivities are well predicted by the join inversion of electromagnetic data. The response surface of the objective function was investigated to assess the sensitivity of the subsurface layer conductivities. The sensitivity of the conductivity for the top two layers is less as compared to the deeper layers. The proposed approach is promising for the fast mapping of true conductivity distributions over large areas.

  13. Cone-shaped source characteristics and inductance effect of transient electromagnetic method

    Science.gov (United States)

    Yang, Hai-Yan; Li, Feng-Ping; Yue, Jian-Hua; Guo, Fu-Sheng; Liu, Xu-Hua; Zhang, Hua

    2017-03-01

    Small multi-turn coil devices are used with the transient electromagnetic method (TEM) in areas with limited space, particularly in underground environments such as coal mines roadways and engineering tunnels, and for detecting shallow geological targets in environmental and engineering fields. However, the equipment involved has strong mutual inductance coupling, which causes a lengthy turn-offtime and a deep "blind zone". This study proposes a new transmitter device with a conical-shape source and derives the radius formula of each coil and the mutual inductance coefficient of the cone. According to primary field characteristics, results of the two fields created, calculation of the conical-shaped source in a uniform medium using theoretical analysis, and a comparison of the inductance of the new device with that of the multi-turn coil, show that inductance of the multi-turn coil is nine times greater than that of the conical source with the same equivalent magnetic moment of 926.1 A·m2. This indicates that the new source leads to a much shallower "blind zone." Furthermore, increasing the bottom radius and turn of the cone creates a larger mutual inductance but increasing the cone height results in a lower mutual inductance. Using the superposition principle, the primary and secondary magnetic fields for a conical source in a homogeneous medium are calculated; results indicate that the magnetic behavior of the cone is the same as that of the multi-turn coils, but the transient responses of the secondary field and the total field are more stronger than those of the multi-turn coils. To study the transient response characteristics using a cone-shaped source in a layered earth, a numerical filtering algorithm is then developed using the fast Hankel transform and the improved cosine transform, again using the superposition principle. During development, an average apparent resistivity inverted from the induced electromotive force using each coil is defined to

  14. Comparing bulk electrical conductivities spatial series obtained by Time Domain Reflectometry and Electromagnetic Induction sensors

    Science.gov (United States)

    Saeed, Ali; Ajeel, Ali; dragonetti, giovanna; Comegna, Alessandro; Lamaddalena, Nicola; Coppola, Antonio

    2016-04-01

    solution (and of the water content) induced by natural soil heterogeneity. Thus, the variability of TDR readings is expected to come from a combination of smaller and larger-scale variations. By contrast, an EMI sensor reading partly smoothes the small-scale variability seen by a TDR probe. As a consequence, the variability revealed by profile-integrated EMI and local (within a given depth interval) TDR readings may have completely different characteristics. In this study, a comparison between the variability patterns of σb revealed by TDR and EMI sensors was carried out. The database came from a field experiment conducted in the Mediterranean Agronomic Institute (MAI) of Valenzano (Bari). The soil was pedologically classified as Colluvic Regosol, consisting of a silty loam with an average depth of 60 cm on a shallow fractured calcareous rock. The experimental field (30m x 15.6 m; for a total area of 468 m2) consisted of three transects of 30 m length and 4.2 width, cultivated with green bean and irrigated with three different salinity levels (1 dS/m, 3dS/m, 6dS/m). Each transect consisted of seven crop rows irrigated by a drip irrigation system (dripper discharge q=2 l/h.). Water salinity was induced by adding CaCl2 to the tap water. All crop-soil measurements were conducted along the middle row at 24 monitoring sites, 1m apart. The spatial and temporal evolution of bulk electrical conductivity (σb) of soil was monitored by i) an Electromagnetic Induction method (EM38-DD) and ii) Time Domain Reflectometry (TDR). Herein we will focus on the methodology we used to elaborate the database of this experiment. Mostly, the data elaboration was devoted to make TDR and EMI data actually comparable. Specifically, we analysed the effect of the different observation windows of TDR and EMI sensors on the different spatial and temporal variability observed in the data series coming from the two sensors. After exploring the different patterns and structures of variability of the

  15. Electromagnetics

    CERN Document Server

    Rothwell, Edward J

    2009-01-01

    Introductory concepts Notation, conventions, and symbology The field concept of electromagneticsThe sources of the electromagnetic field Problems Maxwell's theory of electromagnetism The postulate Maxwell's equations in moving frames The Maxwell-Boffi equations Large-scale form of Maxwell's equationsThe nature of the four field quantities Maxwell's equations with magnetic sources Boundary (jump) conditions Fundamental theorems The wave nature of the electromagnetic field ProblemsThe static electromagnetic field Static fields and steady currents ElectrostaticsMagnetostatics Static field theorem

  16. A Missile-Borne Angular Velocity Sensor Based on Triaxial Electromagnetic Induction Coils

    Directory of Open Access Journals (Sweden)

    Jian Li

    2016-09-01

    Full Text Available Aiming to solve the problem of the limited measuring range for angular motion parameters of high-speed rotating projectiles in the field of guidance and control, a self-adaptive measurement method for angular motion parameters based on the electromagnetic induction principle is proposed. First, a framework with type bent “I-shape” is used to design triaxial coils in a mutually orthogonal way. Under the condition of high rotational speed of a projectile, the induction signal of the projectile moving across a geomagnetic field is acquired by using coils. Second, the frequency of the pulse signal is adjusted self-adaptively. Angular velocity and angular displacement are calculated in the form of periodic pulse counting and pulse accumulation, respectively. Finally, on the basis of that principle prototype of the sensor is researched and developed, performance of measuring angular motion parameters are tested on the sensor by semi-physical and physical simulation experiments, respectively. Experimental results demonstrate that the sensor has a wide measuring range of angular velocity from 1 rps to 100 rps with a measurement error of less than 0.3%, and the angular displacement measurement error is lower than 0.2°. The proposed method satisfies measurement requirements for high-speed rotating projectiles with an extremely high dynamic range of rotational speed and high precision, and has definite value to engineering applications in the fields of attitude determination and geomagnetic navigation.

  17. Improved Geoarchaeological Mapping with Electromagnetic Induction Instruments from Dedicated Processing and Inversion

    Directory of Open Access Journals (Sweden)

    Anders Vest Christiansen

    2016-12-01

    Full Text Available Increasingly, electromagnetic induction methods (EMI are being used within the area of archaeological prospecting for mapping soil structures or for studying paleo-landscapes. Recent hardware developments have made fast data acquisition, combined with precise positioning, possible, thus providing interesting possibilities for archaeological prospecting. However, it is commonly assumed that the instrument operates in what is referred to as Low Induction Number, or LIN. Here, we detail the problems of the approximations while discussing a best practice for EMI measurements, data processing, and inversion for understanding a paleo-landscape at an Iron Age human bone depositional site (Alken Enge in Denmark. On synthetic as well as field data we show that soil mapping based on EMI instruments can be improved by applying data processing methodologies from adjacent scientific fields. Data from a 10 hectare study site was collected with a line spacing of 1–4 m, resulting in roughly 13,000 processed soundings, which were inverted with a full non-linear algorithm. The models had higher dynamic range in the retrieved resistivity values, as well as sharper contrasts between structural elements than we could obtain by looking at data alone. We show that the pre-excavation EMI mapping facilitated an archaeological prospecting where traditional trenching could be replaced by a few test pits at selected sites, hereby increasing the chance of finding human bones. In a general context we show that (1 dedicated processing of EMI data is necessary to remove coupling from anthropogenic structures (fences, phone cables, paved roads, etc., and (2 that carrying out a dedicated full non-linear inversion with spatial coherency constraints improves the accuracy of resistivities and structures over using the data as they are or using the Low Induction Number (LIN approximation.

  18. Algorithm for Identification Electromagnetic Parameters of an Induction Motor When Running on a Three-Phase Power Plant

    Directory of Open Access Journals (Sweden)

    D. Odnolko

    2013-01-01

    Full Text Available Synthesized algorithm for electromagnetic rotor time constant, active resistance and equivalent leakage inductance of stator induction motor for free rotating rotor. The problem is solved for induction motor model in the stationary stator frame α-β. The algorithm is based on the use of recursive least squares method, which ensures high accuracy of the parameter estimates for the minimum time. The observer does not assume prior information about the technical data machine and individual parameters of its equivalent circuit. Results of simulation demonstrated how effective of the proposed method of identification. The flexible structure of the algorithm allows it to be used for preliminary identification of an induction motor, and in the process operative work induction motor in the frequency-controlled electric drive with vector control.

  19. Electromagnetic wave attenuation measurements in a ring-shaped inductively coupled air plasma

    Energy Technology Data Exchange (ETDEWEB)

    Xiaolong, Wei; Haojun, Xu; Min, Lin; Chen, Su [Science and Technology on Plasma Dynamics Laboratory, Air Force Engineering University, Xi' an 710038 (China); Jianhai, Li [Institute of Aerospace Engineering, Air Force Engineering University, Xi' an 710038 (China)

    2015-05-28

    An aerocraft with the surface, inlet and radome covered large-area inductive coupled plasma (ICP) can attenuate its radar echo effectively. The shape, thickness, and electron density (N{sub e}) distribution of ICP are critical to electromagnetic wave attenuation. In the paper, an air all-quartz ICP generator in size of 20 × 20 × 7 cm{sup 3} without magnetic confinement is designed. The discharge results show that the ICP is amorphous in E-mode and ring-shaped in H-mode. The structure of ICP stratifies into core region and edge halo in H-mode, and its width and thickness changes from power and pressure. Such phenomena are explained by the distribution of RF magnetic field, the diffusion of negative ions plasma and the variation of skin depth. In addition, the theoretical analysis shows that the N{sub e} achieves nearly uniform within the electronegative core and sharply steepens in the edge. The N{sub e} of core region is diagnosed by microwave interferometer under varied conditions (pressure in range of 10–50 Pa, power in 300–700 W). Furthermore, the electromagnetic wave attenuation measurements were carried out with the air ICP in the frequencies of 4–5 GHz. The results show that the interspaced ICP is still effective to wave attenuation, and the wave attenuation increases with the power and pressure. The measured attenuation is approximately in accordance with the calculation data of finite-different time-domain simulations.

  20. Vacuum Polarisation Tensors in Constant Electromagnetic Fields Part III

    CERN Document Server

    Gies, Holger; Gies, Holger; Schubert, Christian

    2001-01-01

    The string-inspired technique is used for a first calculation of the one-loop axialvector vacuum polarisation in a general constant electromagnetic field. A compact result is reached for the difference between this tensor and the corresponding vector vacuum polarisation. This result is confirmed by a Feynman diagram calculation. Its physical relevance is briefly discussed.

  1. A Novel Tactile Sensor with Electromagnetic Induction and Its Application on Stick-Slip Interaction Detection

    Directory of Open Access Journals (Sweden)

    Yanjie Liu

    2016-03-01

    Full Text Available Real-time detection of contact states, such as stick-slip interaction between a robot and an object on its end effector, is crucial for the robot to grasp and manipulate the object steadily. This paper presents a novel tactile sensor based on electromagnetic induction and its application on stick-slip interaction. An equivalent cantilever-beam model of the tactile sensor was built and capable of constructing the relationship between the sensor output and the friction applied on the sensor. With the tactile sensor, a new method to detect stick-slip interaction on the contact surface between the object and the sensor is proposed based on the characteristics of friction change. Furthermore, a prototype was developed for a typical application, stable wafer transferring on a wafer transfer robot, by considering the spatial magnetic field distribution and the sensor size according to the requirements of wafer transfer. The experimental results validate the sensing mechanism of the tactile sensor and verify its feasibility of detecting stick-slip on the contact surface between the wafer and the sensor. The sensing mechanism also provides a new approach to detect the contact state on the soft-rigid surface in other robot-environment interaction systems.

  2. Explaining electromagnetic induction: a critical re-examination. The clinical value of history in physics

    Science.gov (United States)

    Roche, J.

    1987-03-01

    The study of the historical evolution of a theory or explanation in physics can help to improve the present understanding of it. Superseded theories sometimes linger on in modern physics literature. Technical terms devised more than a century ago, perhaps, may now be misleading or inappropriate. Well established conventional explanations or auxiliary constructions may become so familiar that they may occasionally be mistaken for correct physical explanations. Students who fail to recognise the historical origins and present status of such concepts may find themselves unable to fit them into a coherent picture, and may become perplexed or even discouraged as a result. History can often help to clarify such problems and it may even suggest a solution. As a case history illustrating this approach, the author briefly examines the more qualitative aspects of some of the explanations which leading physicists have offered for electromagnetic induction during the past one hundred and fifty years or so. He uses the term 'correct' physical explanation to mean an explanation which is in close agreement with experimental evidence and with modern fundamental theory and also one which is logically sound and accurately worded.

  3. Physics Almost Saved the President! Electromagnetic Induction and the Assassination of James Garfield: A Teaching Opportunity in Introductory Physics

    Science.gov (United States)

    Overduin, James; Molloy, Dana; Selway, Jim

    2014-03-01

    Electromagnetic induction is probably one of the most challenging subjects for students in the introductory physics sequence, especially in algebra-based courses. Yet it is at the heart of many of the devices we rely on today. To help students grasp and retain the concept, we have put together a simple and dramatic classroom demonstration that combines sight and sound with a compelling personal story from U.S. history. Other classroom activities dealing with induction have been discussed in this journal, but we believe that this one will be especially likely to attract and retain student interest, particularly in courses geared toward medical, biological, and other non-physics majors.

  4. An analysis of how electromagnetic induction and Faraday's law are presented in general physics textbooks, focusing on learning difficulties

    Science.gov (United States)

    Guisasola, Jenaro; Zuza, Kristina; Almudi, José-Manuel

    2013-07-01

    Textbooks are a very important tool in the teaching-learning process and influence important aspects of the process. This paper presents an analysis of the chapter on electromagnetic induction and Faraday's law in 19 textbooks on general physics for first-year university courses for scientists and engineers. This analysis was based on criteria formulated from the theoretical framework of electromagnetic induction in classical physics and students' learning difficulties concerning these concepts. The aim of the work presented here is not to compare a textbook against the ideal book, but rather to try and find a series of explanations, examples, questions, etc that provide evidence on how the topic is presented in relation to the criteria above. It concludes that despite many aspects being covered properly, there are others that deserve greater attention.

  5. Experimental and computational investigation of an electromagnetic pump used for manufacturing aluminium parts

    Science.gov (United States)

    Morinigo, D.; Rodrigues, M. A.; Rivas, A.; Duque, O.; Vazquez, V.; Maroto, J. A.; Cuesta, R.

    2007-03-01

    An experimental and computational investigation was carried out on an electromagnetic pump for molten aluminum. The electromagnetic pump is a MHD device to drive molten metals by means of electromagnetic fields and without mechanical parts in contact with the metal at high temperature. An exact computer simulation of the electromagnetic pump would require the simultaneous solution of electromagnetic and fluid dynamics problems. However, in this study we divide the simulation into two independent stages. First, the electromagnetic system is simulated by ANSYS considering the secondary of the pump as a solid. This simulation is experimentally validated in a test bed with a solid secondary replacing the molten metal. Secondly, a 3D field of electromagnetic forces provided by the ANSYS simulation is imported into the FLUENT CFD code to simulate the fluid dynamic problem, considering now the secondary of the pump as a liquid. This second simulation is also experimentally validated by measuring the static head provided by the pump. This simulation process is valid only if the electromagnetic system and the fluid dynamic problem are uncoupled, which has been verified by calculating the magnetic Reynolds number and the interaction parameter. Tables 4, Figs 14, Refs 15.

  6. Electromagnetic Induction Survey at an Archaeological Site in Chapingo (Central Mexico)

    Science.gov (United States)

    Salas, J. L.; Arango, C.; Cabral-Cano, E.; Arciniega-Ceballos, A.; Vergara, F.; Novo, X.

    2013-05-01

    The aim of this work is to locate buried remains of ancient civil constructions belonging to the Teotihuacan culture in Chapingo, Central Mexico. Several housing structures of this culture have been found during the excavation of a pipe trench within the University of Chapingo campus in the town of Chapingo. These units were found at 6 m deep covered by recent lacustrine sediments. In order to further explore the extension of this settlement that could guide further excavations and shed more light into these settlements, we have initiated a multi technique geophysical exploration. Here we present the initial results from this survey. An electromagnetic induction survey (EMI) was carried out to characterize the subsurface in an area of about 16,000 m2. We used a GF Instruments CMD-4 conductivity meter to map the horizontal distribution of the subsurface electrical conductivity. This instrument was operated in a continuous mode and linked to a single frequency GPS receiver attached to the probe to georeference the survey. The distance between the probe coils was 3.77 m and the investigation depth range was 4-6 m. The resulting electrical conductivity map shows two low conductivity zones with a NW-SE orientation. The inphase map also presented these characteristics. Since the electrical conductivity is associated with the material compaction, low conductivity values are expected for highly consolidated material; thus our results suggest that these low conductivity features could be related to areas that were the soil was compacted to serve as foundation of these ancient structures. The EMI survey present good initial results and will be expanded along with other techniques such as electrical tomography and ground penetrating radar in the near future in order to better map the extend of Teotihuacan culture in the region.

  7. Inversion of multi-frequency electromagnetic induction data for 3D characterization of hydraulic conductivity

    Science.gov (United States)

    Brosten, T.R.; Day-Lewis, F. D.; Schultz, G.M.; Curtis, G.P.; Lane, J.W.

    2011-01-01

    Electromagnetic induction (EMI) instruments provide rapid, noninvasive, and spatially dense data for characterization of soil and groundwater properties. Data from multi-frequency EMI tools can be inverted to provide quantitative electrical conductivity estimates as a function of depth. In this study, multi-frequency EMI data collected across an abandoned uranium mill site near Naturita, Colorado, USA, are inverted to produce vertical distribution of electrical conductivity (EC) across the site. The relation between measured apparent electrical conductivity (ECa) and hydraulic conductivity (K) is weak (correlation coefficient of 0.20), whereas the correlation between the depth dependent EC obtained from the inversions, and K is sufficiently strong to be used for hydrologic estimation (correlation coefficient of -0.62). Depth-specific EC values were correlated with co-located K measurements to develop a site-specific ln(EC)-ln(K) relation. This petrophysical relation was applied to produce a spatially detailed map of K across the study area. A synthetic example based on ECa values at the site was used to assess model resolution and correlation loss given variations in depth and/or measurement error. Results from synthetic modeling indicate that optimum correlation with K occurs at ~0.5m followed by a gradual correlation loss of 90% at 2.3m. These results are consistent with an analysis of depth of investigation (DOI) given the range of frequencies, transmitter-receiver separation, and measurement errors for the field data. DOIs were estimated at 2.0??0.5m depending on the soil conductivities. A 4-layer model, with varying thicknesses, was used to invert the ECa to maximize available information within the aquifer region for improved correlations with K. Results show improved correlation between K and the corresponding inverted EC at similar depths, underscoring the importance of inversion in using multi-frequency EMI data for hydrologic estimation. ?? 2011.

  8. A Brief History of the use of Electromagnetic Induction Techniques in Soil Survey

    Science.gov (United States)

    Brevik, Eric C.; Doolittle, James

    2017-04-01

    Electromagnetic induction (EMI) has been used to characterize the spatial variability of soil properties since the late 1970s. Initially used to assess soil salinity, the use of EMI in soil studies has expanded to include: mapping soil types; characterizing soil water content and flow patterns; assessing variations in soil texture, compaction, organic matter content, and pH; and determining the depth to subsurface horizons, stratigraphic layers or bedrock, among other uses. In all cases the soil property being investigated must influence soil apparent electrical conductivity (ECa) either directly or indirectly for EMI techniques to be effective. An increasing number and diversity of EMI sensors have been developed in response to users' needs and the availability of allied technologies, which have greatly improved the functionality of these tools and increased the amount and types of data that can be gathered with a single pass. EMI investigations provide several benefits for soil studies. The large amount of georeferenced data that can be rapidly and inexpensively collected with EMI provides more complete characterization of the spatial variations in soil properties than traditional sampling techniques. In addition, compared to traditional soil survey methods, EMI can more effectively characterize diffuse soil boundaries and identify included areas of dissimilar soils within mapped soil units, giving soil scientists greater confidence when collecting spatial soil information. EMI techniques do have limitations; results are site-specific and can vary depending on the complex interactions among multiple and variable soil properties. Despite this, EMI techniques are increasingly being used to investigate the spatial variability of soil properties at field and landscape scales. The future should witness a greater use of multiple-frequency and multiple-coil EMI sensors and integration with other sensors to assess the spatial variability of soil properties. Data analysis

  9. Comparison of different techniques for the FLUENTpyright-based treatment of the electromagnetic field in inductively coupled plasma torches

    Science.gov (United States)

    Bernardi, D.; Colombo, V.; Ghedini, E.; Mentrelli, A.

    2003-11-01

    A new technique for using the CFD commercial code FLUENT^{\\copyright} to simulate inductively coupled plasma torches by means of two-dimensional axisymmetric models is presented. The method is based on an external user-defined function (UDF) which fully solves the electromagnetic field equations, letting the FLUENT^{\\copyright} built-in module calculate only the plasma temperature and velocity fields inside the torch region. In this framework, computations have been carried out for LTE, optica lly thin argon plasmas at atmospheric pressure, using extended grid models with either magnetic dipole or vanishing vector potential boundary conditions for the electromagnetic field. It is shown that our newly developed technique is up to 60% faster on each iteration than that using user-defined scalars (UDS) previously proposed in the literature, as the need of solving flow field equations also outside the plasma zone is eliminated. Calculations are also performed using exact integral boundary conditions for the vector potential, as given by the standard electromagnetic field approach, taking into account the effects of both exciting and induced currents. The corresponding results are compared with the approximate ones obtained by employing extended grid models, showing that for small radial dimensions of the electromagnetic field domain, the magnetic dipole boundary conditions give more realistic solutions than those assuming a vanish ing vector potential.

  10. An innovative experimental sequence on electromagnetic induction and eddy currents based on video analysis and cheap data acquisition

    Science.gov (United States)

    Bonanno, A.; Bozzo, G.; Sapia, P.

    2017-11-01

    In this work, we present a coherent sequence of experiments on electromagnetic (EM) induction and eddy currents, appropriate for university undergraduate students, based on a magnet falling through a drilled aluminum disk. The sequence, leveraging on the didactical interplay between the EM and mechanical aspects of the experiments, allows us to exploit the students’ awareness of mechanics to elicit their comprehension of EM phenomena. The proposed experiments feature two kinds of measurements: (i) kinematic measurements (performed by means of high-speed video analysis) give information on the system’s kinematics and, via appropriate numerical data processing, allow us to get dynamic information, in particular on energy dissipation; (ii) induced electromagnetic field (EMF) measurements (by using a homemade multi-coil sensor connected to a cheap data acquisition system) allow us to quantitatively determine the inductive effects of the moving magnet on its neighborhood. The comparison between experimental results and the predictions from an appropriate theoretical model (of the dissipative coupling between the moving magnet and the conducting disk) offers many educational hints on relevant topics related to EM induction, such as Maxwell’s displacement current, magnetic field flux variation, and the conceptual link between induced EMF and induced currents. Moreover, the didactical activity gives students the opportunity to be trained in video analysis, data acquisition and numerical data processing.

  11. Electromagnetic induction in the oceans and the anomalous behaviour of coastal C-responses for periods up to 20 days

    DEFF Research Database (Denmark)

    Kuvshinov, A.V.; Olsen, Nils; Avdeev, D.B.

    2002-01-01

    [1] Electromagnetic transfer functions at coastal sites are known to be strongly distorted by the conductivity of the seawater. This ocean effect is generally considered to be small for periods greater than a few days. We revise this statement by detailed and systematic model studies in the period...... range from 1 to 64 days, with subsequent comparison of the modelled and observed electromagnetic responses. The conductivity model consists of a radial symmetric (1-D) section that is overlaid by a thin spherical surface shell, the conductance of which is compiled using the NOAA ETOPO topography...... that peculiarities in the observed coastal responses in the period range from 1 to 20 days can be explained to a large amount by induction in the oceans. We show that correction for the ocean effect results in responses that are much better interpretable by 1-D conductivity models compared to the uncorrected...

  12. Revealing the connectivity of groundwater and surface water using electromagnetic induction measurements

    Science.gov (United States)

    Binley, A. M.; McLachlan, P.; Chambers, J. E.; Uhlemann, S.

    2016-12-01

    It is now widely recognised that hydrological and biogeochemical processes that occur at the interface of groundwater (GW) and surface water (SW) can have a significant impact on catchment water quality and ecosystem health. Significant heterogeneity in the fabric of the subsurface at the GW-SW interface can lead to complex fluid flow pathways, both of which can exert a strong control on biogeochemical cycling. Revealing such heterogeneity remains a challenge because of the limitations of traditional field experimental processes. Such traditional techniques are often invasive, which often prevents their use in ecologically sensitive environments. Furthermore, they are often limited to localised characterisation. Studies to date have thus focussed on relatively small (easily accessible) stream environments, at short reach, or plot, scales. There is a clear demand for techniques that can capture the heterogeneity of sediments and pore fluids over larger scales. Geophysical methods may offer valuable information at such scales, particularly when used in combination with traditional sampling approaches. The value of electrical methods for revealing detailed information about the heterogeneity of sediments at the GW-SW interface has been demonstrated, and in a few studies such methods have assisted tracer tests in mapping the solute pathways. However, most investigations have been confined to relatively small scale (tens of metres). There is growing (and renewed) interest in the use of frequency domain electromagnetic induction (EMI) techniques in hydrogeophysics. At the GW-SW interface these methods allow rapid, non-invasive exploration of the top few metres. Relatively recent technological developments have provided multi-coil instrumentation, permitting rapid assessment of electrical conductivity at multiple depths of investigation. Here, we demonstrate the effectiveness of EMI for revealing the heterogeneity of sediments and flow pathways at the GW-SW interface. We

  13. Can we quantify the variability of soil moisture across scales using Electromagnetic Induction ?

    Science.gov (United States)

    Robinet, Jérémy; von Hebel, Christian; van der Kruk, Jan; Govers, Gerard; Vanderborght, Jan

    2017-04-01

    Soil moisture is a key variable in many natural processes. Therefore, technological and methodological advancements are of primary importance to provide accurate measurements of spatial and temporal variability of soil moisture. In that context, ElectroMagnetic Induction (EMI) instruments are often cited as a hydrogeophysical method with a large potential, through the measurement of the soil apparent electrical conductivity (ECa). To our knowledge, no studies have evaluated the potential of EMI to characterize variability of soil moisture on both agricultural and forested land covers in a (sub-) tropical environment. These differences in land use could be critical as differences in temperature, transpiration and root water uptake can have significant effect, notably on the electrical conductivity of the pore water. In this study, we used an EMI instrument to carry out a first assessment of the impact of deforestation and agriculture on soil moisture in a subtropical region in the south of Brazil. We selected slopes of different topographies (gentle vs. steep) and contrasting land uses (natural forest vs. agriculture) within two nearby catchments. At selected locations on the slopes, we measured simultaneously ECa using EMI and a depth-weighted average of the soil moisture using TDR probes installed within soil pits. We found that the temporal variability of the soil moisture could not be measured accurately with EMI, probably because of important temporal variations of the pore water electrical conductivity and the relatively small temporal variations in soil moisture content. However, we found that its spatial variability could be effectively quantified using a non-linear relationship, for both intra- and inter-slopes variations. Within slopes, the ECa could explained between 67 and 90% of the variability of the soil moisture, while a single non-linear model for all the slopes could explain 55% of the soil moisture variability. We eventually showed that combining

  14. Design of Circular, Square, Single, and Multi-layer Induction Coils for Electromagnetic Priming Using Inductance Estimates

    Science.gov (United States)

    Fritzsch, Robert; Kennedy, Mark W.; Aune, Ragnhild E.

    2018-02-01

    Special induction coils used for electro magnetic priming of ceramic foam filters in liquid metal filtration have been designed using a combination of analytical and finite element modeling. Relatively simple empirical equations published by Wheeler in 1928 and 1982 have been used during the design process. The equations were found to accurately predict the z-component of the magnetic flux densities of both single- and multi-layer coils as verified both experimentally and by using COMSOL® 5.1 multiphysics simulations.

  15. Coupling of electromagnetic and thermal codes. Induction heating; Couplage des codes electromagnetique et thermique. Le chauffage par induction

    Energy Technology Data Exchange (ETDEWEB)

    Colombani, M. [CEDRAT, (France)

    1997-12-31

    The development and adjustment of induction heating systems is quite delicate because two different subjects of physics are involved: magnetism (Foucault currents) and thermal engineering. Moreover, the magnetic and electrical properties depends on the temperature and the dissipated power depends on the magnetic and electrical properties and on the electrical excitation sources (geometry, intensity, frequency). The CEDRAT company has been involved since several years in the development of modeling softwares which allow to analyze these kind of problems. The most used is the FLUX2D software, developed by CEDRAT RECHERCHE in collaboration with the LEG (CNRS-INPG) and EdF, and which is used in several domains of applications (electric motors, actuators, high-voltage devices, magnetic recording, induction heating etc..). This software is based on a finite-element calculation method and, in the case of induction heating, it can perform different types of modeling: magnetic, thermal, temperature-dependant properties, weak and strong coupling, coupling with the electric circuit equations etc.. (J.S.)

  16. Electromagnetism

    CERN Document Server

    Grant, Ian S

    1990-01-01

    The Manchester Physics Series General Editors: D. J. Sandiford; F. Mandl; A. C. Phillips Department of Physics and Astronomy, University of Manchester Properties of Matter B. H. Flowers and E. Mendoza Optics Second Edition F. G. Smith and J. H. Thomson Statistical Physics Second Edition F. Mandl Electromagnetism Second Edition I. S. Grant and W. R. Phillips Statistics R. J. Barlow Solid State Physics Second Edition J. R. Hook and H. E. Hall Quantum Mechanics F. Mandl Particle Physics Second Edition B. R. Martin and G. Shaw the Physics of Stars Second Edition A. C. Phillips Computing for Scient

  17. Experimental verification of sensing capability of an electromagnetic induction system for an MR fluid damper-based control system

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H J; Jang, D D [Department of Civil and Environmental Engineering, KAIST, 305-701, Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Cho, S W [Samsung SDS Co., Ltd., Yeoksam-dong, Gangnam-gu, Seoul 135-918 (Korea, Republic of); Koo, J H [Department of Mechanical and Manufacturing Engineering, Miami University, Oxford, Ohio 45056 (United States)], E-mail: hjung@kaist.ac.kr

    2009-02-01

    This paper investigates the sensing capability of an Electromagnetic Induction (EMI) system that is incorporated in a vibration control system based on MR fluid dampers. The EMI system, consisting of permanent magnets and coils, converts reciprocal motions (kinetic energy) of MR damper into electrical energy (electromotive force or emf). According to the Faraday's law of electromagnetic induction, the emf signal, produced from the EMI, is proportional to the velocity of the motion. Thus, the induced voltage (emf) signal is able to provide the necessary measurement information (i.e., relative velocity across the damper). In other words, the EMI can act as a sensor in the MR damper system. In order to evaluate the proposed concept of the EMI sensor, an EMI system was constructed and integrated into an MR damper system. The emf signal is experimentally compared with the velocity signal by conducting a series of shaking table tests. The results show that the induced emf voltage signal well agreed with the relative velocity.

  18. Mapping Depth to Argillic Horizon Using Electromagnetic Induction on Historically Farmed Soils within the Piedmont Region of the United States

    Science.gov (United States)

    Ryland, R.; Markewitz, D.; Thompson, A.

    2016-12-01

    Historic agricultural practices throughout the Piedmont region of the southeastern United States from 1820 to 1940 led to accelerated erosion. Practices, such as tilling, degraded soil quality altering hydrologic processes on the landscape by limiting infiltration and leading to overland flow and erosion. Erosion due to these practices has substantially redistributed sediment from upper to lower landscape positions, causing a change in the depth-to-argillic horizon along hillslopes. By mapping the depth to argillic horizon within watersheds that have a history of farming and watersheds with little evidence of agricultural disturbance, a better understanding of the effects of farming practices on erosion and sediment redistribution can be made. This study uses extensive soil sampling within historically farmed and unfarmed watersheds to map spatial variations in the depth to argillic horizon. In addition to sampling, Electro-magnetic Induction (EMI) is being tested and calibrated to clay content and other topographic characteristic (i.e. landscape position, aspect, percent slope) from which the depth to argillic horizon can be predicted. Current hillslope and watershed hydrologic models use characteristics from soil classification maps for parameterization, however, these soil maps may lack sufficient spatial detail and may not accurately represent landscapes that have been eroded from historical farming. The results from this study will improve understanding of previous erosion on sediment redistribution and will characterize the potential use of electromagnetic induction as an accurate and efficient means to predict the depth to the argillic horizon. This information will improve parameterization of hillslope and watershed hydrologic models.

  19. Geophysical investigation of Red Devil mine using direct-current resistivity and electromagnetic induction, Red Devil, Alaska, August 2010

    Science.gov (United States)

    Burton, Bethany L.; Ball, Lyndsay B.

    2011-01-01

    Red Devil Mine, located in southwestern Alaska near the Village of Red Devil, was the state's largest producer of mercury and operated from 1933 to 1971. Throughout the lifespan of the mine, various generations of mills and retort buildings existed on both sides of Red Devil Creek, and the tailings and waste rock were deposited across the site. The mine was located on public Bureau of Land Management property, and the Bureau has begun site remediation by addressing mercury, arsenic, and antimony contamination caused by the minerals associated with the ore deposit (cinnabar, stibnite, realgar, and orpiment). In August 2010, the U.S. Geological Survey completed a geophysical survey at the site using direct-current resistivity and electromagnetic induction surface methods. Eight two-dimensional profiles and one three-dimensional grid of direct-current resistivity data as well as about 5.7 kilometers of electromagnetic induction profile data were acquired across the site. On the basis of the geophysical data and few available soil borings, there is not sufficient electrical or electromagnetic contrast to confidently distinguish between tailings, waste rock, and weathered bedrock. A water table is interpreted along the two-dimensional direct-current resistivity profiles based on correlation with monitoring well water levels and a relatively consistent decrease in resistivity typically at 2-6 meters depth. Three settling ponds used in the last few years of mine operation to capture silt and sand from a flotation ore processing technique possessed conductive values above the interpreted water level but more resistive values below the water level. The cause of the increased resistivity below the water table is unknown, but the increased resistivity may indicate that a secondary mechanism is affecting the resistivity structure under these ponds if the depth of the ponds is expected to extend below the water level. The electromagnetic induction data clearly identified the

  20. Multi-configuration electromagnetic induction measurements at long term agricultural test sites in Germany with different fertilizer and irrigation managements

    Science.gov (United States)

    Kaufmann, Manuela Sarah; von Hebel, Christian; Brogi, Cosimo; Baumecker, Michael; Döring, Thomas; Amelung, Wulf; Vereecken, Harry; van der Kruk, Jan

    2017-04-01

    Electromagnetic induction (EMI) data are often being used to investigate large scale soil properties including clay content, soil water content, and salinity changes for a wide range of applications. For agricultural sites, different management practices such as organic/mineral fertilization, tillage, and/or irrigation are important when interpreting the measured apparent electrical conductivity (ECa). Here, we present EMI data recorded at two long term field experiment (LTFE) agricultural test sites in Thyrow near Berlin (Germany), where different long term fertilizer and irrigation management practices were applied. We used two fixed-boom multi-coil EMI instruments that simultaneously measure over nine different depths of investigation (DOI), recording information ranging between the very shallow (0-0.25 m) ploughing zone including the organic matter and the surface soil (A-Horizon) down to the relatively deep (0-2.7 m) subsoil (B-Horizon) or even substratum (C-Horizon). At both test sites, the prevailing sandy to silty sand in the A- and B-Horizon is underlain by a glacial till C-Horizon resulting in generally low ECa values between 0.5 and 5 mS/m. At one test site, a "static nutrient deficiency experiment" is performed since 1937, where organic fertilizer (farm yard manure) and mineral fertilizers (nitrogen-phosphate-potassium (NPK) and liming) are applied at specific grids. Comparing the fertilizer application grid to the measured EMI data, the lowest ECa values coincide to unfertilized grids whereas the ECa values increase with liming, farm yard manure, and NPK. The visually observed correlation between ECa and the liming treatment was possibly due to the increased pH of the soil, because the fertilizer application increases ion contents that increase the soil electrical conductivity. At the second test site, a "Static Irrigation and Fertilizer Experiment" is conducted, where next to the fertilizer treatment (farm yard manure and nitrogen) part of the field

  1. Digital Mapping of Soil Salinity and Crop Yield across a Coastal Agricultural Landscape Using Repeated Electromagnetic Induction (EMI Surveys.

    Directory of Open Access Journals (Sweden)

    Rongjiang Yao

    Full Text Available Reliable and real-time information on soil and crop properties is important for the development of management practices in accordance with the requirements of a specific soil and crop within individual field units. This is particularly the case in salt-affected agricultural landscape where managing the spatial variability of soil salinity is essential to minimize salinization and maximize crop output. The primary objectives were to use linear mixed-effects model for soil salinity and crop yield calibration with horizontal and vertical electromagnetic induction (EMI measurements as ancillary data, to characterize the spatial distribution of soil salinity and crop yield and to verify the accuracy of spatial estimation. Horizontal and vertical EMI (type EM38 measurements at 252 locations were made during each survey, and root zone soil samples and crop samples at 64 sampling sites were collected. This work was periodically conducted on eight dates from June 2012 to May 2013 in a coastal salt-affected mud farmland. Multiple linear regression (MLR and restricted maximum likelihood (REML were applied to calibrate root zone soil salinity (ECe and crop annual output (CAO using ancillary data, and spatial distribution of soil ECe and CAO was generated using digital soil mapping (DSM and the precision of spatial estimation was examined using the collected meteorological and groundwater data. Results indicated that a reduced model with EMh as a predictor was satisfactory for root zone ECe calibration, whereas a full model with both EMh and EMv as predictors met the requirement of CAO calibration. The obtained distribution maps of ECe showed consistency with those of EMI measurements at the corresponding time, and the spatial distribution of CAO generated from ancillary data showed agreement with that derived from raw crop data. Statistics of jackknifing procedure confirmed that the spatial estimation of ECe and CAO exhibited reliability and high accuracy

  2. Induction of deep, local hyperthermia by ultrasound and electromagnetic fields: problems and choices.

    Science.gov (United States)

    Lele, P P

    1980-01-01

    The feasibility, and the biophysical and engineering concepts underlying the use of electromagnetic energy and ultrasound for production of deep, local hyperthermia are discussed. Focused ultrasound currently is the only modality that can be used for producing controllable levels of hyperthermia localized to deep seated tumors, non-invasively and safely. The ultrasonic focus needs to moved within the tissues around the periphery of the tumor to achieve uniform temperature distributions.

  3. Part of Speech Induction from Distributional Features : Balancing Vocabulary and Context

    NARCIS (Netherlands)

    Datla, V.V.; Louwerse, M.M.; Lin, King-Ip; Eberle, William; Boonthum-Denecke, Chutima

    2014-01-01

    Past research on grammar induction has found promising results in predicting parts-of-speech from n-grams using a fixed vocabulary and a fixed context. In this study, we investigated grammar induction whereby we varied vocabulary size and context size. Results indicated that as context increased for

  4. Numerical simulation of nonequilibrium inductive plasma flow coupled with electromagnetic field calculation

    Science.gov (United States)

    Yu, Minghao; Takahashi, Yusuke; Kihara, Hisashi; Abe, Ken-ichi; Yamada, Kazuhiko; Abe, Takashi

    2014-12-01

    Numerical investigation of nonequilibrium inductively coupled plasma (ICP) flow was carried out to study the physical properties of the flow inside a 10-kW ICP torch with the working gas being nitrogen. The flow field was described by two-dimensional compressible axisymmetric Navier-Stokes (N-S) equations that took into account 5 species and 8 chemical reactions. The magnetic vector-potential equations were tightly coupled with the flow-field equations to describe the heating process by inductive discharge. A four-temperature model was adopted to model thermal nonequilibrium process in the discharge torch. The characteristics of ICP flow such as thermal nonequilibrium, inductive discharge, and strong effects of Lorentz forces became clear through the present study.

  5. Electromagnetic induction in the oceans and the anomalous behaviour of coastal C-responses for periods up to 20 days

    Science.gov (United States)

    Kuvshinov, Alexei V.; Olsen, Nils; Avdeev, Dmitry B.; Pankratov, Oleg V.

    2002-06-01

    Electromagnetic transfer functions at coastal sites are known to be strongly distorted by the conductivity of the seawater. This ocean effect is generally considered to be small for periods greater than a few days. We revise this statement by detailed and systematic model studies in the period range from 1 to 64 days, with subsequent comparison of the modelled and observed electromagnetic responses. The conductivity model consists of a radial symmetric (1-D) section that is overlaid by a thin spherical surface shell, the conductance of which is compiled using the NOAA ETOPO topography/bathymetry and map of sediment thicknesses. The simulations were performed for spatial resolutions of the surface shell of 5° × 5°, 2° × 2° and 1° × 1°, respectively, and for two, continental and oceanic, underlying 1-D conductivity models. The inducing source is described by the spherical harmonic P10 in dipole coordinates. Comparisons are made for the coastal geomagnetic observatories Apia, Hermanus, Kakioka, Kanoya, and Simosato where an anomalous behaviour of the local response has been previously detected. From the comparison of observed and modelled responses we conclude that peculiarities in the observed coastal responses in the period range from 1 to 20 days can be explained to a large amount by induction in the oceans. We show that correction for the ocean effect results in responses that are much better interpretable by 1-D conductivity models compared to the uncorrected responses.

  6. From 1D-Multi-Layer-Conductivity-Inversion to Pseudo-3D-Imaging of Quantified Electromagnetic Induction Data Acquired at a Heterogeneous Test Site

    Science.gov (United States)

    von Hebel, Christian; Rudolph, Sebastian; Huisman, Johan A.; van der Kruk, Jan; Vereecken, Harry

    2013-04-01

    Electromagnetic induction (EMI) systems enable the non-invasive spatial characterization of soil structural and hydrogeological variations, since the measured apparent electrical conductivity (ECa) can be related to changes in soil moisture, soil water, clay content and/or salinity. Due to the contactless operation, ECa maps of relatively large areas, i.e. field to (small) catchment scale, can be measured in reasonably short times. A multi-configuration EMI system with one electromagnetic field transmitter and various receivers with different offsets provide simultaneous ECa measurements that are representative of different sensing depths. Unfortunately, measured ECa values can only be considered as qualitative values due to external influences like the operator, cables or other metal objects. Of course, a better vertical characterization of the subsurface is possible when quantitative measurement values could be obtained. To obtain such quantitative ECa values, the measured EMI apparent conductivities are calibrated using a linear regression approach with predicted apparent conductivities obtained from a Maxwell-based full-solution forward model using inverted electrical resistivity tomography (ERT) data as input. These calibrated apparent conductivities enable a quantitative multi-layer-inversion to resolve for the electrical conductivity of certain layers. To invert for a large scale three-layer model, a one-dimensional (1D) shuffled-complex-evolution inversion scheme was parallelized and run on JUROPA - one of the supercomputers of the Forschungszentrum Jülich. This novel inversion routine was applied to calibrated electromagnetic induction data acquired at the Selhausen test site (Germany), which has a size of about 190 x 70 m. The test site is weakly inclined and a distinct gradient in soil texture is present with considerably higher gravel content at the upper part of the field. Parallel profiles with approximately three meter distance were measured using

  7. Effect of 900 MHz Electromagnetic Radiation on the Induction of ROS in Human Peripheral Blood Mononuclear Cells

    Science.gov (United States)

    Kazemi, E.; Mortazavi, S. M. J.; Ali-Ghanbari, A.; Sharifzadeh, S.; Ranjbaran, R.; Mostafavi-pour, Z.; Zal, F.; Haghani, M.

    2015-01-01

    Background Despite numerous studies over a decade, it still remains controversial about the biological effects of RF EMF emitted by mobile phone telephony. Objective Here we investigated the effect of 900 MHz GSM on the induction of oxidative stress and the level of intracellular reactive oxygen species (ROS) in human mononuclear cells, monocytes and lymphocytes as defence system cells. Method 6 ml Peripheral Blood samples were obtained from 13 healthy volunteers (21-30 year-old). Each sample was devided into 2 groups: one was exposed RF radiation emitted from a mobile phone simulator for 2 hour and the other used as control group which was not exposed to any fields. After that, mononuclear cells were isolated from peripheral blood by density gradient centrifugation in Ficoll-Paque. The intracellular ROS content in monocytes and lymphocytes was measured by the CM-H2DCFDA fluorescence probe using flowcytometry technique. Results Our results showed significant increase in  ROS production after exposure in population rich in monocytes. This effect was not significant in population rich in lymphocytes in comparison with non exposed cells. Conclusion The results obtained in this study clearly showed the oxidative stress induction capability of RF electromagnetic field in the portion of PBMCs mostly in monocytes, like the case of exposure to micro organisms, although the advantages or disadvantages of this effect should be evaluated. PMID:26396966

  8. Effect of 900 MHz Electromagnetic Radiation on the Induction of ROS in Human Peripheral Blood Mononuclear Cells.

    Science.gov (United States)

    Kazemi, E; Mortazavi, S M J; Ali-Ghanbari, A; Sharifzadeh, S; Ranjbaran, R; Mostafavi-Pour, Z; Zal, F; Haghani, M

    2015-09-01

    Despite numerous studies over a decade, it still remains controversial about the biological effects of RF EMF emitted by mobile phone telephony. Here we investigated the effect of 900 MHz GSM on the induction of oxidative stress and the level of intracellular reactive oxygen species (ROS) in human mononuclear cells, monocytes and lymphocytes as defence system cells. 6 ml Peripheral Blood samples were obtained from 13 healthy volunteers (21-30 year-old). Each sample was devided into 2 groups: one was exposed RF radiation emitted from a mobile phone simulator for 2 hour and the other used as control group which was not exposed to any fields. After that, mononuclear cells were isolated from peripheral blood by density gradient centrifugation in Ficoll-Paque. The intracellular ROS content in monocytes and lymphocytes was measured by the CM-H2DCFDA fluorescence probe using flowcytometry technique. Our results showed significant increase in  ROS production after exposure in population rich in monocytes. This effect was not significant in population rich in lymphocytes in comparison with non exposed cells. The results obtained in this study clearly showed the oxidative stress induction capability of RF electromagnetic field in the portion of PBMCs mostly in monocytes, like the case of exposure to micro organisms, although the advantages or disadvantages of this effect should be evaluated.

  9. Effect of 900 MHz Electromagnetic Radiation on the Induction of ROS in Human Peripheral Blood Mononuclear Cells

    Directory of Open Access Journals (Sweden)

    Mortazavi S.M.J.

    2015-09-01

    Full Text Available Background: Despite numerous studies over a decade, it still remains controversial about the biological effects of RF EMF emitted by mobile phone telephony. Objective: Here we investigated the effect of 900 MHz GSM on the induction of oxidative stress and the level of intracellular reactive oxygen species (ROS in human mononuclear cells, monocytes and lymphocytes as defence system cells. Method: 6 ml Peripheral Blood samples were obtained from 13 healthy volunteers (21-30 year-old. Each sample was devided into 2 groups: one was exposed RF radiation emitted from a mobile phone simulator for 2 hour and the other used as control group which was not exposed to any fields. After that, mononuclear cells were isolated from peripheral blood by density gradient centrifugation in Ficoll-Paque. The intracellular ROS content in monocytes and lymphocytes was measured by the CM-H2DCFDA fluorescence probe using flowcytometry technique. Results: Our results showed significant increase in ROS production after exposure in population rich in monocytes. This effect was not significant in population rich in lymphocytes in comparison with non exposed cells. Conclusion: The results obtained in this study clearly showed the oxidative stress induction capability of RF electromagnetic field in the portion of PBMCs mostly in monocytes, like the case of exposure to micro organisms, although the advantages or disadvantages of this effect should be evaluated.

  10. Study on Using Concentrators in the Induction-Hardening Process of a Cylindrical Part

    Directory of Open Access Journals (Sweden)

    BURCA Adrian

    2013-05-01

    Full Text Available Currently the tendency in industry is to reduce the production price of the finished product. One of the most costly components of the final product is electricity. By lowering energy consumption, withoutchanging the quality of the product, production costs may become more reduced while environment will also be protected. Using the ELTA 1D commercial software, this paper has looked at the possibility to reduce energy consumption while tempering (hardening a piece byelectromagnetic induction. It will make a comparison of the electrical parameters of a surface thermal treatment (hardening installation when using a concentrator for electromagnetic field lines and in the situation when the concentrator is not used.

  11. Induction and Conduction Electromagnetic Waves Caused by Lightning Strike on the Low Voltage Network

    Directory of Open Access Journals (Sweden)

    Reynaldo Zoro

    2010-10-01

    Full Text Available Direct and indirect lightning strikes can disturb and induce low voltage overheadlines and it can produced overvoltage due to traveling waves along the lines. This overvoltage can damage the equipments connected to it. It was recorded that there were already a lot of damages of electronic equipments and arrestesr located inside the building of Lightning Measurement Station at Mnt. Tangkuban Perahu. Most of the overvoltage which was developed on the low voltage lines were coming from indirect lightning strike nearby due to the fact that most of the lines were covered by trees. Research was carried out to study and evaluate the induction and conduction of the lightning strikes to the LV lines that can lead to the cause of equipment and arrester damages inside the building. Local lightning data for the analysis were derived from measurement system installed at the stations and historical lightning data from lightning detection network called Jadpen (National Lightning Detection Network. The data was used for calculating and evaluating the voltage elevation, induction voltage profiles and conduction in the form of traveling waves using Rusck Model. Two damaged arresters were evaluated and compared and it give the better understanding on how the protection system work.Keywords: 

  12. Three-dimensional imaging of subsurface structural patterns using quantitative large-scale multiconfiguration electromagnetic induction data

    Science.gov (United States)

    von Hebel, Christian; Rudolph, Sebastian; Mester, Achim; Huisman, Johan A.; Kumbhar, Pramod; Vereecken, Harry; van der Kruk, Jan

    2014-03-01

    Electromagnetic induction (EMI) systems measure the soil apparent electrical conductivity (ECa), which is related to the soil water content, texture, and salinity changes. Large-scale EMI measurements often show relevant areal ECa patterns, but only few researchers have attempted to resolve vertical changes in electrical conductivity that in principle can be obtained using multiconfiguration EMI devices. In this work, we show that EMI measurements can be used to determine the lateral and vertical distribution of the electrical conductivity at the field scale and beyond. Processed ECa data for six coil configurations measured at the Selhausen (Germany) test site were calibrated using inverted electrical resistivity tomography (ERT) data from a short transect with a high ECa range, and regridded using a nearest neighbor interpolation. The quantitative ECa data at each grid node were inverted using a novel three-layer inversion that uses the shuffled complex evolution (SCE) optimization and a Maxwell-based electromagnetic forward model. The obtained 1-D results were stitched together to form a 3-D subsurface electrical conductivity model that showed smoothly varying electrical conductivities and layer thicknesses, indicating the stability of the inversion. The obtained electrical conductivity distributions were validated with low-resolution grain size distribution maps and two 120 m long ERT transects that confirmed the obtained lateral and vertical large-scale electrical conductivity patterns. Observed differences in the EMI and ERT inversion results were attributed to differences in soil water content between acquisition days. These findings indicate that EMI inversions can be used to infer hydrologically active layers.

  13. Induction

    DEFF Research Database (Denmark)

    Sprogøe, Jonas; Elkjaer, Bente

    2010-01-01

    The purpose of this paper is to explore how induction of newcomers can be understood as both organizational renewal and the maintenance of status quo, and to develop ways of describing this in terms of learning.......The purpose of this paper is to explore how induction of newcomers can be understood as both organizational renewal and the maintenance of status quo, and to develop ways of describing this in terms of learning....

  14. Thermomechanical Effects during Direct Chill and Electromagnetic Casting of Aluminum Alloys Part II : Numerical Simulation

    Science.gov (United States)

    Drezet, J.-M.; Rappaz, M.; Krähenbühl, Y.

    The prediction of the ingot deformation during direct chill (DC) and electromagnetic (EM) casting of aluminum alloy slabs would allow the optimization of the mold/inductor shape capable of producing flat ingots. The transient thermomechanical model presented here predicts the deformation and the temperature field evolution during DC/EM casting. Deformation in the solid is assumed to obey a viscoplastic law. The model is validated on the basis of the measurements presented in part I. It enables to predict the influence of casting parameters on butt curl and swell, rolling faces pull-in and residual stress state for DC and EM-cast ingots.

  15. Delineation of salt water intrusion through use of electromagnetic-induction logging: A case study in Southern Manhattan Island, New York

    Science.gov (United States)

    Stumm, Frederick; Como, Michael D.

    2017-01-01

    Groundwater with chloride concentrations up to 15,000 mg/L has intruded the freshwater aquifer underlying southern Manhattan Island, New York. Historical (1940–1950) chloride concentration data of glacial aquifer wells in the study area indicate the presence of four wedges of saltwater intrusion that may have been caused by industrial pumpage. The limited recharge capability of the aquifer, due to impervious surfaces and the 22.7 million liters per day (mld) of reported industrial pumpage early in the 20th Century was probably the cause for the saltwater intrusion and the persistence of the historical saltwater intrusion wedges over time. Recent drilling of wells provided new information on the hydrogeology and extent of saltwater intrusion of the glacial aquifer overlying bedrock. The new observation wells provided ground-water level, chloride concentration, hydraulic conductivity, and borehole geophysical data of the glacial aquifer. The glacial sediments range in thickness from less than 0.3 m to more than 76.2 m within the study area. A linear relation between Electromagnetic-induction (EM) conductivity log response and measured chloride concentration was determined. Using this relation, chloride concentration was estimated in parts of the glacial aquifer where sampling was not possible. EM logging is an effective tool to monitor changes in saltwater intrusion wedges.

  16. A novel method for photo-oxidative degradation of diatrizoate in water via electromagnetic induction electrodeless lamp.

    Science.gov (United States)

    Meng, Lingjun; Yang, Shaogui; Sun, Cheng; He, Huan; Xian, Qiming; Li, Shiyin; Wang, Guoxiang; Zhang, Limin; Jiang, Dong

    2017-09-05

    In this study, an electromagnetic induction electrodeless lamp (EIEL) was first introduced into UV advanced oxidation processes (AOPs) for photodegradation of Diatrizoate (DTZ), which was the most persistent iodinated X-ray contrast medium (ICM), and traditional Hg lamps were taken as references. Direct photolysis rate of DTZ under EIEL irradiation was 1.34 times as that under Hg irradiation, but the electric energy consumption was 0.87 times. In this sense, the combination of EIEL and oxidants (O2, H2O2 and S2O8(2-)(PS)) was further investigated. The remarkably increased photodegradation rates were observed in UV/PS system due to primary contribution rate of SO4(-) (62.5%) based on the results of radical concentrations and second-order rate constants of DTZ with SO4(-) and OH. Inorganic ions influencing the photodegradation process were investigated. The effect of natural organic materials (NOMs) in UV/PS system was studied based on contribution ratios of light screening effect and quenching. Transformation mechanisms of DTZ in UV/PS system included deiodination, intramolecular cyclization, decarboxylation, deacetylation and deamination, which were further confirmed by frontier electron density calculations. The study indicated that UV/PS with EIEL irradiation has the potential to remove pharmaceuticals in contaminated aquatic environments. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Electromagnetic and thermal modelling of induction motors, by accounting for space harmonics; Modelisation electromagnetique et thermique des moteurs a induction, en tenant compte des harmoniques d'espace

    Energy Technology Data Exchange (ETDEWEB)

    Mezani, S.

    2004-07-15

    This work is interested in the study of the electromagnetic and thermal behaviors of the induction motor. A state of the art is initially drawn up, where we have presented and discussed the current methods dealing with electromagnetic and thermal modeling of induction motors. An electromagnetic model, that uses the 2D complex finite element method to solve the field equations, is developed. The rotor movement is accounted for by coupling the air gap field, for each space harmonic, using the double air gap method. The superposition principle permits the determination of the final solution. To deal with non linear problems, an approach that introduces equivalent reluctivities, is proposed. We have assumed that the saturation is only due to the first space harmonic. A thermal model is elaborated by using the nodal method. The machine is cut up into 11 cylindrical lumped elements, the thermal model represents the juxtaposition of these lumped elements. The electromagnetic and thermal models are, weakly, coupled together for a more precise determination of the temperature distribution inside the motor. In the validation phase of our work, we have designed a test bench that allows specific torque and temperature measurements. The comparison of the calculations and the measurements is satisfactory. (author)

  18. 10 CFR Appendix H to Part 110 - Illustrative List of Electromagnetic Enrichment Plant Equipment and Components Under NRC Export...

    Science.gov (United States)

    2010-01-01

    ... Equipment and Components Under NRC Export Licensing Authority H Appendix H to Part 110 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) EXPORT AND IMPORT OF NUCLEAR EQUIPMENT AND MATERIAL Pt. 110, App. H Appendix H to Part 110—Illustrative List of Electromagnetic Enrichment Plant Equipment and Components Under...

  19. The controlled-source electromagnetic response of two buried plates, including mutual inductance and interaction with the host medium

    Science.gov (United States)

    Stalnaker, J. L.; Everett, M. E.

    2002-12-01

    A solution for the response of multiple buried plates in a host medium to controlled-source electromagnetic (CSEM) stimulation has been found. This solution accounts for the interaction between the plates and the host medium. The solution for a plate in free space is well-known and analytic. However, adding a second plate or a conducting host medium increases the complexity of the solution. Time-varying currents induced by the source in the plates and the host medium introduce new magnetic flux to the system that in turn modify the currents via mutual inductance. This solution is obtained by solving the (A,φ ) potential formulation of Maxwell's equations using the finite element method. The finite element mesh generator allows for local refinement of the mesh in regions where greater resolution is desirable. This allows finer meshing in the region of the plates, which allows for more accurate modeling of the nuances in the induced currents caused by the interaction between the plates and the host medium. The effect of mutual induction and the efficacy of the locally refined finite element solution are demonstrated. The response of a model containing two plates within a host medium is compared to the sum of the responses of the two plates modeled separately. The plates are 2 m by 2 m, with a separation distance of 1 m, buried at a depth of 1 m. The plates have a conductivity of 100 S/m, and are within a host medium of conductivity 0.01 S/m. The system is excited by a source with a frequency between 1 and 100 kHz. It is shown that the model response of a two-plate system differs from the sum of the responses of two one-plate systems. The interaction between the two plates and the host medium must be properly modeled. An accurate model of the interaction of buried conductors excited by a controlled source is necessary to properly discriminate and classify buried targets. This is particularly true in the near-surface region of the earth where complex heterogeneity is

  20. Calibration and large-scale inversion of fixed-boom multi-configuration electromagnetic induction data for soil characterization

    Science.gov (United States)

    von Hebel, Christian; van der Kruk, Jan; Mester, Achim; Altdorff, Daniel; Endres, Anthony; Huisman, Johann A.; Vereecken, Harry

    2017-04-01

    Fixed-boom multi-configuration electromagnetic induction (EMI) devices can be used as non-invasive large-scale shallow subsurface imaging tools. Commercially available devices convert the measured magnetic fields into an apparent electrical conductivity (ECa), which can be shifted due to the presence of the operator and the system setup, e.g., GPS, cables, etc. When measuring the same transect either by hand or by using a sled using an EMI device with coil offsets between 32 and 118 cm oriented vertical or horizontal coplanar (VCP, HCP), we found significant ECa shifts up to 12 mS/m, i.e., 70% of maximum measured ECa. To investigate and remove these ECa shifts, 43 collocated EMI and electrical resistivity tomography (ERT) measurements were performed using different field setups, where 18 data sets using the identical sled setup showed consistent shifts that were largest for VCP and small coil offsets and decreased for increasing coil offsets and HCP mode. The ERT data were used to calibrate and thus obtain quantitative ECa values. In this way, multi-layered EMI inversions could be successfully performed, which would not have been possible without the calibration. By combining multiple multi-configuration EMI devices having different coil offsets and orientations, the initial three-layer inversion using six EMI coil configurations (offsets between 32 und 118 cm) for the upper 2 meter has been extended to a five-layer inversion using 24 EMI coil configurations (offsets between 32 and 410 cm) for the upper 4 meter. The multi-layer inversion uses the L1-norm and a global optimization algorithm that respects the non-linearity that is present between the magnetic fields and the electrical conductivity as described by the Maxwell's equations. In this way, no low induction number approximation is made such that the approach is accurate for a wide range of subsurface electrical conductivities. The parallelized inversion scheme inverts each measurement position separately

  1. Identifying soil management zones in a sugarcane field using proximal sensed electromagnetic induction and gamma-ray spectrometry data

    Science.gov (United States)

    Dennerley, Claire; Huang, Jingyi; Nielson, Rod; Sefton, Michael; Triantafilis, John

    2017-04-01

    Over 70% of the Australian sugarcane industry operates in alluvial-estuarine areas characterised by sodic and infertile soils. There is a need to supply ameliorants and improve fertilisers and minimise off-farm pollution to the Great Barrier Reef. Therefore, information is required about the spatial variation in soils. However, traditional approaches are cost-prohibitive. Herein we showed how a digital soil mapping (DSM) approach can be used to identify soil management zones. In the first instance, ancillary data, including electromagnetic induction and gamma-ray spectrometry data were collected. Using a fuzzy k-means clustering algorithm management zones from two to six were identified. Using restricted maximum likelihood (REML) analysis of various topsoil (0-0.3m) and subsoil (0.6-0.9m) physical (e.g. clay) and chemical (e.g. exchangeable sodium percentage [ESP], exchangeable calcium and magnesium) properties, 3 zones were determined from minimising the mean squared prediction error. To manage the moderately sodic topsoil ESP of zones 3A and 3C and sodic 3B, different gypsum requirements were prescribed. Lime can also be added differentially to address low exchangeable Ca in zone 3A, 3B and 3C. With regard to exchangeable Mg, zones 3A and 3C do not require any fertiliser, whereas zone 3A requires the addition of a moderate amount. The results were consistent with percentage yield variance, suggesting the lower yield in 3C due to topsoil sodicity and strongly sodic subsoil with higher clay content. We concluded that the DSM approach was successful in identifying soil management zones and can be used to improve structural stability and soil fertility.

  2. Enhanced signal processing algorithms for buried unexploded ordnance detection and location estimation with magnetometer and electromagnetic induction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Witten, A.

    1993-09-01

    Enhanced signal processing algorithms have been developed for the detection and location of buried unexploded ordnance using magnetometry and electromagnetic induction (EMI) measurements. These signal processing algorithms are related to those used to image with geophysical diffraction tomography (GDT) employing wave-based measurements. The underlying relationship of GDT is the Generalized Projection Slice Theorem (GPST) that relates the spatial Fourier transform of acquired data to the spatial Fourier transform of subsurface inhomogeneities of one higher dimension. This relationship can be used to simulate data templates for known targets and, by virtue of the shift property of Fourier transforms, a data simulation need only be computed for one reference target location. All other target locations are generated by an appropriate phase shift. These data templates can be correlated with acquired data to determine the spatial distribution of probable target location. This approach to target detection and location estimation, referred to as a maximum likelihood estimation, can be used to produce an {open_quotes}image{close_quotes} of the likelihood of a specified target`s position. For non wave-based methods, the relationship between data and target characteristics is not strictly associated with Fourier transforms. In the case of magnetometry, the appropriate GPST requires a Fourier-Laplace transform of the target characteristics while the EMI GPST is based on an integral transform with a complex wavenumber. Nevertheless, the shift rule for integral transforms can be invoked to yield GPST`s for these tools and the associated computationally efficient maximum likelihood estimators. The EMI detection algorithm was applied to data acquired at a known underground storage tank site and the algorithms for both magnetometry and EMI were applied to data acquired at the Magnetic Range of the Naval EOD Tech Center in Indian Head, Maryland.

  3. Estimation of soil salinity in a drip irrigation system by using joint inversion of multicoil electromagnetic induction measurements

    KAUST Repository

    Jadoon, Khan Zaib

    2015-05-12

    Low frequency electromagnetic induction (EMI) is becoming a useful tool for soil characterization due to its fast measurement capability and sensitivity to soil moisture and salinity. In this research, a new EMI system (the CMD mini-Explorer) is used for subsurface characterization of soil salinity in a drip irrigation system via a joint inversion approach of multiconfiguration EMI measurements. EMI measurements were conducted across a farm where Acacia trees are irrigated with brackish water. In situ measurements of vertical bulk electrical conductivity (σb) were recorded in different pits along one of the transects to calibrate the EMI measurements and to compare with the modeled electrical conductivity (σ) obtained by the joint inversion of multiconfiguration EMI measurements. Estimates of σ were then converted into the universal standard of soil salinity measurement (i.e., electrical conductivity of a saturated soil paste extract – ECe). Soil apparent electrical conductivity (ECa) was repeatedly measured with the CMD mini-Explorer to investigate the temperature stability of the new system at a fixed location, where the ambient air temperature increased from 26°C to 46°C. Results indicate that the new EMI system is very stable in high temperature environments, especially above 40°C, where most other approaches give unstable measurements. In addition, the distribution pattern of soil salinity is well estimated quantitatively by the joint inversion of multicomponent EMI measurements. The approach of joint inversion of EMI measurements allows for the quantitative mapping of the soil salinity distribution pattern and can be utilized for the management of soil salinity.

  4. Electromagnetic NDT to characterize usage properties of flat steel products - Part 3

    Energy Technology Data Exchange (ETDEWEB)

    Altpeter, I.; Dobmann, G.; Szielasko, K., E-mail: iab.altlau@t-online.de, E-mail: gerd.dobmann@t-online.de, E-mail: klaus.szielasko@izfp.fraunhofer.de [Fraunhofer Inst. - IZFP, Saarbruecken (Germany)

    2015-11-15

    The Fraunhofer Institute for Nondestructive Testing (IZFP) in Saarbruecken, Germany, started its activities in materials characterization of flat steel products in the eighties of the last century in the basic program of the European Community of Coal and Steel (ECCS). Throughout the years, continuous research and development were performed. The objective of the work, presented within this three-part series of reports, is to discuss the history of an innovation that began in 1988 with R&D in the area of texture characterization in steel sheets produced for car-body manufacturing (Part 1). In the following years the activities were to automate online property determination in terms of yield strength, tensile strength, planar- and vertical-anisotropy factors. Again, steel sheets were the focus of the developments and first NDT systems came into industrial application. Parallel research was performed to characterize the mechanical properties and hardness on heavy steel plates, mainly produced for pipeline manufacturing and offshore applications (Part 2). The final report in the series (Part 3) discusses steel sheet characterization and presents the successful development of a combination transducer that combines ultrasonics with electromagnetic NDT. (author)

  5. Thermomechanical Effects during Direct Chill and Electromagnetic Casting of Aluminum Alloys Part I : Experimental Investigation

    Science.gov (United States)

    Drezet, J.-M.; Plata, M.

    The deformation and the temperature field evolution within direct chill (DC) and electromagnetic (EM) cast aluminum ingots have been measured in-situ using a simple experimental set-up. The deformation of the cross section of the cold ingots has also been characterized as a function of the casting speed, alloy composition and inoculation condition. The pull-in of the lateral rolling faces has been found to occur in two sequences for DC cast ingots whereas that associated with EMC was continuous. The pull-in was maximum at the center of these faces (about 7-9 %) and strongly depended upon the casting speed. The present results constitute a basis for the validation of the model presented in part II.

  6. Mean-Adaptive Real-Coding Genetic Algorithm and its Applications to Electromagnetic Optimization (Part One

    Directory of Open Access Journals (Sweden)

    Z. Raida

    2007-09-01

    Full Text Available In the paper, a novel instance of the real-coding steady-state genetic algorithm, called the Mean-adaptive real-coding genetic algorithm, is put forward. In this instance, three novel implementations of evolution operators are incorporated. Those are a recombination and two mutation operators. All of the evolution operators are designed with the aim of possessing a big explorative power. Moreover, one of the mutation operators exhibits self-adaptive behavior and the other exhibits adaptive behavior, thereby allowing the algorithm to self-control its own mutability as the search advances. This algorithm also takes advantage of population-elitist selection, acting as a replacement policy, being adopted from evolution strategies. The purpose of this paper (i.e., the first part is to provide theoretical foundations of a robust and advanced instance of the real-coding genetic algorithm having the big potential of being successfully applied to electromagnetic optimization.

  7. Algorithm for Identification Electromagnetic Parameters of an Induction Motor When Running on a Three-Phase Power Plant

    National Research Council Canada - National Science Library

    D. Odnolko

    2013-01-01

    .... The flexible structure of the algorithm allows it to be used for preliminary identification of an induction motor, and in the process operative work induction motor in the frequency-controlled electric drive with vector control.

  8. Novel quantitative calibration approach for multi-configuration electromagnetic induction (EMI) systems using data acquired at multiple elevations

    Science.gov (United States)

    Tan, Xihe; Mester, Achim; von Hebel, Christian; van der Kruk, Jan; Zimmermann, Egon; Vereecken, Harry; van Waasen, Stefan

    2017-04-01

    Electromagnetic induction (EMI) systems offer a great potential to obtain highly resolved layered electrical conductivity models of the shallow subsurface. State-of-the-art inversion procedures require quantitative calibration of EMI data, especially for short-offset EMI systems where significant data shifts are often observed. These shifts are caused by external influences such as the presence of the operator, zero-leveling procedures, the field setup used to move the EMI system and/or cables close by. Calibrations can be performed by using collocated electrical resistivity measurements or taking soil samples, however, these two methods take a lot of time in the field. To improve the calibration in a fast and concise way, we introduce a novel on-site calibration method using a series of apparent electrical conductivity (ECa) values acquired at multiple elevations for a multi-configuration EMI system. No additional instrument or pre-knowledge of the subsurface is needed to acquire quantitative ECa data. By using this calibration method, we correct each coil configuration, i.e., transmitter and receiver coil separation and the horizontal or vertical coplanar (HCP or VCP) coil orientation with a unique set of calibration parameters. A multi-layer soil structure at the corresponding measurement location is inverted together with the calibration parameters using full-solution Maxwell equations for the forward modelling within the shuffled complex evolution (SCE) algorithm to find the optimum solution under a user-defined parameter space. Synthetic data verified the feasibility for calibrating HCP and VCP measurements of a custom made six-coil EMI system with coil offsets between 0.35 m and 1.8 m for quantitative data inversions. As a next step, we applied the calibration approach on acquired experimental data from a bare soil test field (Selhausen, Germany) for the considered EMI system. The obtained calibration parameters were applied to measurements over a 30 m

  9. Full-waveform modeling of Zero-Offset Electromagnetic Induction for Accurate Characterization of Subsurface Electrical Properties

    Science.gov (United States)

    Moghadas, D.; André, F.; Vereecken, H.; Lambot, S.

    2009-04-01

    Water is a vital resource for human needs, agriculture, sanitation and industrial supply. The knowledge of soil water dynamics and solute transport is essential in agricultural and environmental engineering as it controls plant growth, hydrological processes, and the contamination of surface and subsurface water. Increased irrigation efficiency has also an important role for water conservation, reducing drainage and mitigating some of the water pollution and soil salinity. Geophysical methods are effective techniques for monitoring the vadose zone. In particular, electromagnetic induction (EMI) can provide in a non-invasive way important information about the soil electrical properties at the field scale, which are mainly correlated to important variables such as soil water content, salinity, and texture. EMI is based on the radiation of a VLF EM wave into the soil. Depending on its electrical conductivity, Foucault currents are generated and produce a secondary EM field which is then recorded by the EMI system. Advanced techniques for EMI data interpretation resort to inverse modeling. Yet, a major gap in current knowledge is the limited accuracy of the forward model used for describing the EMI-subsurface system, usually relying on strongly simplifying assumptions. We present a new low frequency EMI method based on Vector Network Analyzer (VNA) technology and advanced forward modeling using a linear system of complex transfer functions for describing the EMI loop antenna and a three-dimensional solution of Maxwell's equations for wave propagation in multilayered media. VNA permits simple, international standard calibration of the EMI system. We derived a Green's function for the zero-offset, off-ground horizontal loop antenna and also proposed an optimal integration path for faster evaluation of the spatial-domain Green's function from its spectral counterpart. This new integration path shows fewer oscillations compared with the real path and permits to avoid the

  10. A Comparison of Electromagnetic Induction and Electrical Resistivity Tomography Techniques for Monitoring of Shallow Soil Moisture Dynamics

    Science.gov (United States)

    Endres, A. L.; Toy, C.; Van-Lane, P. R.; Campbell, W. J.; Steelman, C. M.

    2014-12-01

    While the capacity of both electromagnetic induction (EMI) and electrical resistivity tomography (ERT) to monitor shallow soil moisture dynamics has been extensively examined, there have been few studies comparing the results of these two techniques. These comparative studies have primarily treated ERT as the more reliable method and focussed on the potential shortcoming (i.e., calibration and stability) of EMI devices. Further, these studies have been very limited in terms of their duration and the range of soil moisture conditions observed. Concurrent EMI and ERT surveys we acquired during a 36-month period to monitor changes in shallow moisture conditions at a clayey vineyard located in Vineland, Ontario, Canada is an excellent data set for such a comparison between these geoelectrical techniques. A wide range of soil moisture conditions were encountered during this monitoring program including wet spring and fall, dry summer, and frozen winter periods. Also, the effects of variations in hydrological processes between contrasting annual cycles (e.g., wet versus dry summer conditions) can be seen in these hydrogeophysical data. In addition, procedures were followed during the EMI data acquisition to minimize calibration and stability issues. We found very good agreement between these two geoelectrical techniques during the relatively wet conditions during fall to spring period. However, there is significant deviation between these methods during the summer period with the EMI data indicating less conductive (i.e., drier) conditions than the ERT data. This deviation is larger for the EMI horizontal dipole data, indicating that the source of this discrepancy is located in shallow near-surface. In addition, the comparison of gravimetric soil moisture measurements with both geoelectrical data sets shows a substantially better correlation between soil moisture and the EMI data, implying that there are significant limitations with the ERT technique in this application

  11. Seismo-electromagnetic phenomena in the western part of the Eurasia-Nubia plate boundary

    Science.gov (United States)

    Gonçalves da Silva, Hugo; Bezzeghoud, Mourad; Biagi, Pier; Namorado Rosa, Rui; Salgueiro da Silva, Manuel; Caldeira, Bento; Heitor Reis, Artur; Borges, José Fernando; Tlemçani, Mouhaydine; Manso, Marco

    2010-05-01

    This paper presents a future research plan that aims to monitor Seismo-electromagnetic (SEM) phenomena in the western part of the Eurasia-Nubia plate boundary (WENP). This region has a significant tectonic activity [1] combined with relatively low electromagnetic noise levels and for that reason presents the possibility to perform high quality SEM measurements. Further, it is known that low-frequency [ultra (ULF), very (VLF), and low-frequencies (LF)] electromagnetic (EM) waves produce more convincing earthquake precursors (compared to higher frequencies) because of less contamination, large skin depth, and low attenuation [2]. Thus, two SEM effects will be considered: ULF electromagnetic field emissions [3], and VLF/LF radio broadcastings [4]. With respect to the ULF measurements, as a start, three ULF sensors are planned to be installed in the South of Iberian Peninsula supported by the existing networks of seismic research stations. Subsequent development of this initial plan could result in the implementation of a lager ULF monitoring network not only in the Iberian Peninsula, but also in the rest of Europe. Possible integration in the SEGMA array is now under consideration. Another perspective is to use a portable station to track seismic events. Regarding the VLF/LF radio broadcastings, a receiver is planned to be mounted in University of Évora. Radio signals from up to 10 transmitters (in these bands) of interest to study the seismic activity in the WENP region will be monitored. Actually, the radio path from the transmitter to the receiver should cross the epicentral area, therefore two possible transmitters are the ones installed in Monaco (France) and Sicily (Italy). Furthermore, the system will integrate the INFREP network and in this context it will not be restricted to WENP region. With the development of these research plans we aim to collect novel SEM data emerging from the seismic activity in the WENP region. We expect to address the time

  12. Mars Methane Analogue Mission (M3): Near Subsurface Electromagnetic Techniques and Analysis

    Science.gov (United States)

    Boivin, A.; Samson, C.; Holladay, J. S.; Cloutis, E. A.; Ernst, R. E.

    2012-03-01

    As part of the Canadian Space Agency's Mars Methane Analogue Mission, a micro-rover mission, an Electromagnetic Induction Sounder (EMIS) was used with the goal of demonstrating its value as a potential science instrument onboard future rovers.

  13. Selecting the induction heating for normalization of deposited surfaces of cylindrical parts

    Directory of Open Access Journals (Sweden)

    Олена Валеріївна Бережна

    2017-07-01

    Full Text Available The machine parts recovered by electric contact surfacing with metal strip are characterized by high loading of the surface layer, which has a significant impact on their performance. Therefore, the improvement of the operational stability of fast-wearing machine parts through the use of combined treatment technologies is required. Not all the work-piece but just the worn zones are subjected to recovery with electric contact surfacing; the tape thickness and depth of the heat affected zone being not more than a few millimeters. Therefore, the most optimal in this case is the use of a local surface heating method of high frequency currents. This method has economical benefits because there is no need to heat the entire work-piece. The induction heating mode at a constant power density has been proposed and analytically investigated. The ratios that make it possible to determine the main heating parameters ensuring calculation of the inductor for the normalization of the reconstructed surface of cylindrical parts have been given. These parameters are: specific power, frequency and warm-up time. The proposed induction heating mode is intermediate between the quenching and cross-cutting heating and makes it possible to simultaneously obtain the required temperatures at the surface and at the predetermined depth of the heated layer of cylindrical parts with the normalization of their surfaces restored with electric contact surfacing

  14. Radiofrequency identification and medical devices: the regulatory framework on electromagnetic compatibility. Part I: medical devices.

    Science.gov (United States)

    Censi, Federica; Mattei, Eugenio; Triventi, Michele; Bartolini, Pietro; Calcagnini, Giovanni

    2012-05-01

    Radiofrequency identification (RFID) technology has acheived significant success and has penetrated into various areas of healthcare. Several RFID-based applications are used in various modalities with the ultimate aim of improving patient care. When a wireless technology is used in a healthcare environment, attention must be paid to the potential risks deriving from its use; one of the most important being electromagnetic interference with medical devices. In this paper, the regulatory framework concerning the electromagnetic compatibility between RFID and medical devices is analyzed to understand whether and how the application of the current standards allows for the effective control of the risks of electromagnetic interference.

  15. Development of multi-frequency array induction logging (MAIL) tool. Part 4; Multi shuhasu array gata induction kenso (MAIL) tool no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sato, T.; Otsuka, K.; Takasugi, S. [GERD Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan); Uchida, T. [New Energy and Industrial Technology Development Organization, Tokyo, (Japan)

    1997-05-27

    NEDO is now carrying out `the deep-seated geothermal resource survey` with the aim of surveying deep geothermal resource lying 3,000m below sea level. `The development of resistivity use investigation technology` being carried out as element technology for this survey conducts well surveys and earth surface-well surveys using the drilled deep wells. By analyzing these surveys together with electromagnetic method surveys including the MT method carried out on the earth surface, the survey was aimed at grasping in high resolution resistivity structures from the shallow underground to the deep underground. The multi-frequency array induction logging being researched as the well survey is a method to grasp resistivity structures within a radius of several meters of the well using the electromagnetic logging method. The paper reported the field test conducted this time using the improved tool. A comparison of the data obtained in the test with the results of the normal logging showed consistency, and therefore, it showed that the tool itself fully grasped responses from strata. 3 refs., 5 figs., 1 tab.

  16. Asymmetric Ultrasonic Pulse Radiation Using Electromagnetic-Induction Transducer and PZT(Pb(Zr-Ti)O3) Transducer with Wave Synthesis Method

    Science.gov (United States)

    Endoh, Nobuyuki; Yamamoto, Koji

    1993-05-01

    In medical applications, especially in urology, we use a fragmentation calculus technique with shock waves. This technique is very profitable because of no abdominal surgery for a human being. Large negative sound amplitude pulses, however, can cause problems such as internal hemorrhage or pain in the human body. The final goal of this study is to develop a means to project an intense positive unipolar pulse without negative sound pressure. We improved a composite transducer consisting of an electromagnetic-induction-type (EMI) transducer and PZT (Pb(Zr-Ti)O3) transducers. An EMI transducer consisting of a metal coil and vibration membrane can project intense sound pulses into water. In order to suppress its negative sound pressure, we project a compensation pulse with PZT transducers using an inverse filtering method. An asymmetric pulse whose P+ to P- amplitude ratio was very high was projected in water.

  17. Feasibility study of a swept frequency electromagnetic probe (SWEEP) using inductive coupling for the determination of subsurface conductivity of the earth and water prospecting in arid regions

    Science.gov (United States)

    Latorraca, G. A.; Bannister, L. H.

    1974-01-01

    Techniques developed for electromagnetic probing of the lunar interior, and techniques developed for the generation of high power audio frequencies were combined to make practical a magnetic inductive coupling system for the rapid measurement of ground conductivity profiles which are helpful when prospecting for the presence and quality of subsurface water. A system which involves the measurement of the direction, intensity, and time phase of the magnetic field observed near the surface of the earth at a distance from a horizontal coil energized so as to create a field that penetrates the earth was designed and studied to deduce the conductivity and stratification of the subsurface. Theoretical studies and a rudimentary experiment in an arid region showed that the approach is conceptually valid and that this geophysical prospecting technique can be developed for the economical exploration of subterranean water resources.

  18. In vitro studies on callus induction in both vegetative and generative parts in Alstroemeria for further application to transformation

    NARCIS (Netherlands)

    Kim, J.B.; Jeu, de M.J.; Raemakers, C.J.J.M.; Jacobsen, E.; Visser, R.G.F.

    2001-01-01

    We compared both vegetative and generative parts of Alstroemeria in friable embryogenic callus induction, and subsequent production of somatic embryos and regeneration of plants because there exist only a few protocols with low efficiency for application to transformation. Nodal parts of the plant

  19. Detection of near-surface horizontal anisotropy in a weathered metamorphic schist at Llano Uplift (Texas) by transient electromagnetic induction

    Science.gov (United States)

    Collins, Jamie L.; Everett, Mark E.; Johnson, Brann

    2006-10-01

    The use of transient controlled-source electromagnetic prospecting to detect buried, steeply dipping foliation in metamorphic rocks is illustrated with data acquired over the Precambrian Packsaddle schist in the Llano Uplift of central Texas. The azimuthal variation of the transient voltage at a given transmitter-receiver separation about a fixed central point is consistent with the forward model response of a homogeneous halfspace exhibiting horizontal electrical anisotropy. The loop-loop exploration configuration is ideally suited to probe horizontal anisotropy. A quantitative match of the forward response to the observed data produces reasonable electrical conductivity values and coefficient of anisotropy for resistive, crystalline geological materials. The most conductive direction consistently lies within a few degrees of the geologically mapped foliation strike direction. The electrical anisotropy is strongest below the near-surface weathered layer, within the more competent bedrock. The agent responsible for generating the anistropy cannot be definitively determined, because it is likely to be a combination of geological factors, such as weathering, compositional banding and microcracking, all of which enhance electrical conductivity parallel to the plane of foliation. The transient electromagnetics is supplemented by DC resistivity and seismic surveys. The elastic anisotropy is evident in the near-surface weathered layer, but it may not persist very deep into the underlying competent schist. The exposure of foliated schist at the surface is not sufficient to rule out a possible role for systematically aligned macrofracture sets as a secondary cause of the observed anisotropy.

  20. An Electromagnetic Sensor for the Autonomous Running of Visually Impaired and Blind Athletes (Part II: The Wearable Device).

    Science.gov (United States)

    Pieralisi, Marco; Di Mattia, Valentina; Petrini, Valerio; De Leo, Alfredo; Manfredi, Giovanni; Russo, Paola; Scalise, Lorenzo; Cerri, Graziano

    2017-02-16

    Currently, the availability of technology developed to increase the autonomy of visually impaired athletes during sports is limited. The research proposed in this paper (Part I and Part II) focuses on the realization of an electromagnetic system that can guide a blind runner along a race track without the need for a sighted guide. In general, the system is composed of a transmitting unit (widely described in Part I) and a receiving unit, whose components and main features are described in this paper. Special attention is paid to the definition of an electromagnetic model able to faithfully represent the physical mechanisms of interaction between the two units, as well as between the receiving magnetic sensor and the body of the user wearing the device. This theoretical approach allows for an estimation of the signals to be detected, and guides the design of a suitable signal processing board. This technology has been realized, patented, and tested with a blind volunteer with successful results and this paper presents interesting suggestions for further improvements.

  1. A Study of Active Rotor-Blade Vibration Control using Electro-Magnetic Actuation - Part II: Experiment

    DEFF Research Database (Denmark)

    Christensen, Rene Hardam; Santos, Ilmar

    2004-01-01

    mistuning, can easily be generated by substitution or rearranging the blades. Six sets of electro-magnetic actuators are applied to the system in order to control the blades as well as the rotor vibrations. Four sets of actuators are mounted in the rotating disc acting directly onto each one of the blades......This is the second paper in a two-part study on active rotor-blade vibration control. This part presents an experimental contribution into the work of active controller design for rotor-blade systems. The primary aim is to give an experimental validation and show the applicability...... of the theoretical results presented in part 1 of the study. A test rig of a coupled rotor-blade system, where blades flexible motion is coupled to rotor lateral motion, is build for the experimental research. The rig is build by four flexible blades radially attached onto a rotating rigid disc and shaft. The rigid...

  2. Gunshot residue testing in suicides: Part II: Analysis by inductive coupled plasma-atomic emission spectrometry.

    Science.gov (United States)

    Molina, D Kimberley; Castorena, Joe L; Martinez, Michael; Garcia, James; DiMaio, Vincent J M

    2007-09-01

    Several different methods can be employed to test for gunshot residue (GSR) on a decedent's hands, including scanning electron microscopy with energy dispersive x-ray (SEM/EDX) and inductive coupled plasma-atomic emission spectrometry (ICP-AES). In part I of this 2-part series, GSR results performed by SEM/EDX in undisputed cases of suicidal handgun wounds were studied. In part II, the same population was studied, deceased persons with undisputed suicidal handgun wounds, but GSR testing was performed using ICP-AES. A total of 102 cases were studied and analyzed for caliber of weapon, proximity of wound, and the results of the GSR testing. This study found that 50% of cases where the deceased was known to have fired a handgun immediately prior to death had positive GSR results by ICP/AES, which did not differ from the results of GSR testing by SEM/EDX. Since only 50% of cases where the person is known to have fired a weapon were positive for GSR by either method, this test should not be relied upon to determine whether someone has discharged a firearm and is not useful as a determining factor of whether or not a wound is self-inflicted or non-self-inflicted. While a positive GSR result may be of use, a negative result is not helpful in the medical examiner setting as a negative result indicates that either a person fired a weapon prior to death or a person did not fire a weapon prior to death.

  3. Electromagnetic Field Analysis of the Performance of Single-Phase Capacitor-Run Induction Motor Using Composite Rotor Conductor

    Directory of Open Access Journals (Sweden)

    Mohd Afaque Iqbal

    2014-06-01

    Full Text Available Single-phase induction motor (SPIM has very crucial role in industrial, domestic and commercial sectors. So, the efficient SPIM is a major requirement of today’s market. For efficient motors, many research methodologies and suggestions have been given by researchers in past. Various parameters like as stator/rotor slot variation, size and shape of stator/rotor slots, stator/rotor winding configuration, choice of core material etc. have significant impact on machine design. Rotor slot geometry influences the distribution of the magnetic field to a degree. Even a little difference of the magnetic field distribution can make big difference on the performance of the induction motor. The rotor slot geometry influences the skin effect and slot leakage flux in order to increase the torque and efficiency. In this paper, three types of rotor slot configurations are designed and simulated with different rotor slot configuration and rotor bars composition by changing the rotor slot configuration of base model. Aluminum and Copper are used simultaneously as rotor winding material. The rotor bar is a composite conductor which carries Aluminum as well as Copper sub-conductors running parallel in the same slot. Overall cross section area of rotor bar in each model kept same and work is carried out with difference proportion of Aluminum and Copper sub conductors. All models are investigated and simulated in FEMM and finally the simulated results are compared for optimal solution.

  4. Multiconfiguration electromagnetic induction survey for paleochannel internal structure imaging: a case study in the alluvial plain of the River Seine, France

    Science.gov (United States)

    Rejiba, Fayçal; Schamper, Cyril; Chevalier, Antoine; Deleplancque, Benoit; Hovhannissian, Gaghik; Thiesson, Julien; Weill, Pierre

    2018-01-01

    The La Bassée floodplain area is a large groundwater reservoir controlling most of the water exchanged between local aquifers and hydrographic networks within the Seine River basin (France). Preferential flows depend essentially on the heterogeneity of alluvial plain infilling, whose characteristics are strongly influenced by the presence of mud plugs (paleomeander clayey infilling). These mud plugs strongly contrast with the coarse sand material that composes most of the alluvial plain, and can create permeability barriers to groundwater flows. A detailed knowledge of the global and internal geometry of such paleomeanders can thus lead to a comprehensive understanding of the long-term hydrogeological processes of the alluvial plain. A geophysical survey based on the use of electromagnetic induction was performed on a wide paleomeander, situated close to the city of Nogent-sur-Seine in France. In the present study we assess the advantages of combining several spatial offsets, together with both vertical and horizontal dipole orientations (six apparent conductivities), thereby mapping not only the spatial distribution of the paleomeander derived from lidar data but also its vertical extent and internal variability.

  5. Conductivity gradients as inferred by electromagnetic-induction meter (EM38) readings within a salt-affected wetland in Saskatchewan, Canada

    Science.gov (United States)

    Mirck, Jaconette; Schroeder, William

    2018-01-01

    The change from deep-rooted grass and shrub vegetation to annual-cropping dryland farming has contributed to serious soil salinization challenges on the semi-arid North American Great Plains. In some cases, cultivation of the Great Plains has increased the availability of water, causing dominant sulfate salts to travel from the uphill areas to depressions where it will surface when water evaporates at the soil surface. A potential solution could include the replanting of the native deep-rooted vegetation, which requires knowledge of the spatial distribution of soil salinity. This study tested the soil factors influencing electromagnetic-induction meter (EM38) readings of soil salinity distribution around wetlands. The objectives were to: (1) predict growth and survival of Salix dasyclados Wimm. (cv. `India') along a salinity gradient in a small wetland, and (2) investigate whether newly established willows affected water-table fluctuations, which would indicate their phreatophytic nature or their ability to obtain their water supply from the zone of saturation. Results indicated significantly lower salinity values for sampling points with EM38 readings above 175 and 250 mS m-1 for height and survival, respectively. In addition, diurnal fluxes of the water table in areas of good willow growth and lower salinity indicated that cultivar `India' was phreatophytic in these areas and therefore has great potential for being used to combat saline seeps.

  6. Case Study Regarding the Design of a Direct Current Electromagnet for the MIG Welding of Metallic Materials Part II: Constructive-Electromagnetic Dimension and Verification of the Electromagnet Operation

    Directory of Open Access Journals (Sweden)

    Tudorel Ene

    2016-10-01

    Full Text Available The paper refers to the design of a direct current electromagnet, located on the head of a swan neck welding gun of a MIG welding equipment and used for magnetising the rotation space of two additional electric arches, in order to preheat the electrode wire and of the protective gas, partially turned into plasma jet. We present the constructive - electromagnetic dimensioning and the verification of the electromagnet operation.

  7. Performance of Prototypes for the Barrel Part of the ANDA Electromagnetic Calorimeter

    Science.gov (United States)

    Rosenbaum, Christoph; Diehl, S.; Dormenev, V.; Drexler, P.; Kavatsyuk, M.; Kuske, T.; Nazarenko, S.; Novotny, R.; Rosier, P.; Ryazantsev, A.; Wieczorek, P.; Wilms, A.; Zaunick, H.-G.; P¯ANDA Collaboration

    2016-08-01

    The performance of the most recent prototypes of the ANDA barrel electromagnetic calorimeter (EMC) will be compared. The first large scale prototype PROTO60 was designed to test the performance of the improved tapered lead tungstate crystals (PWO-II). The PROTO60 which consists of 6 × 10 crystals was tested at various accelerator facilities over the complete envisaged energy range fulfilling the requirements of the TDR of the ANDA EMC in terms of energy, position and time resolution. To realize the final barrel geometry and to test the final front end electronics, a second prototype PROTO120 has been constructed. It represents a larger section of a barrel slice, containing the most tapered crystals and the close to final components for the ANDA EMC. The performance of both prototypes will be compared with a focus on the analysis procedure including the signal extraction, noise rejection, calibration and the energy resolution. In addition, the influence of the non-uniformity of the crystal on the energy resolution will be discussed.

  8. A Study of Active Rotor-Blade Vibration Control using Electro-Magnetic Actuation - Part I: Theory

    DEFF Research Database (Denmark)

    Christensen, Rene Hardam; Santos, Ilmar

    2004-01-01

    actuators fixed directly in the blades. However, due to the impracticability and problems by fixing actuators in the rotating blades, it is for practical application of great interest to study whether the vibrations can be controlled using shaft-based actuators, i.e. electro-magnetic bearings......This is the first paper in a two-part study on active rotor-blade vibration control. Blade faults are a major problem in bladed machines, such as turbines and compressors. Moreover, increasing demands for higher efficiency, lower weight and higher speed imply that blades become even more...... susceptible to vibrational problems. Passive damping methods, such as frictional damping, are typically used for this kind of machines, working very well at the specific design conditions. However, when the running conditions exceed the design specification, then passive damping devices become inefficient...

  9. Electromagnetic compatibility (EMC) part 6-2 : generic standards : immunity for industrial environments

    CERN Document Server

    International Electrotechnical Commission. Geneva

    1999-01-01

    Applies to electrical and electronic apparatus intended for use in industrial environments, for which no designed product or product-family immunity standard exists. Immunity requirements in the frequency range 0 Hz to 400 GHz are covered, in relation to continuous and transient, conducted and radiated disturbances, including electrostatic discharges. Test requirements are specified for each port considered. Apparatus intended to be used in industrial locations are characterized by the existence of one or more of the following: - a power network exists powered by a high or medium voltage power transformer for the supply of an installation feeding manufacturing or similar plant; - industrial, scientific and medical (ISM) apparatus; - heavy inductive or capacitive loads are frequently switched; - currents and associated magnetic fields are high.

  10. Electromagnetic compatibility (EMC) part 6-2 : generic standards : immunity for industrial environments

    CERN Document Server

    International Electrotechnical Commission. Geneva

    2005-01-01

    Applies to electrical and electronic apparatus intended for use in industrial environments, for which no designed product or product-family immunity standard exists. Immunity requirements in the frequency range 0 Hz to 400 GHz are covered, in relation to continuous and transient, conducted and radiated disturbances, including electrostatic discharges. Test requirements are specified for each port considered. Apparatus intended to be used in industrial locations are characterized by the existence of one or more of the following: - a power network exists powered by a high or medium voltage power transformer for the supply of an installation feeding manufacturing or similar plant; - industrial, scientific and medical (ISM) apparatus; - heavy inductive or capacitive loads are frequently switched; - currents and associated magnetic fields are high.

  11. Electromagnetic modeling of the rings of the squirrel cage of an induction motor; Modelado electromagnetico de los anillos de la jaula de ardilla de un motor de induccion

    Energy Technology Data Exchange (ETDEWEB)

    Limones Montoya, Juan Carlos

    2004-03-15

    An electromagnetic lineal model of a three-phase induction motor was developed in this thesis. The Finite element method in two dimensions was used. The model formulation takes into account the coupling with the stator wires and solid conductors of the rotor. In other words, the stator phases and squirrel-cage end-rings are considered in the model. The resulting set of electric-circuit and magnetic-field equations are solved simultaneously with the Incomplete Cholesky Bi-Conjugate Gradient Method using a matrix storage technique known as symmetric coordinate storage. The model was programmed in the C programming language. The magnetic field model is represented by the diffusion equation, which allows to compute the induced Eddy currents in the conducting material due to the sinusoidal stator excitation. The modelled induction motor has a rated power of 2.2 kW, 220 V, 9.6/11.0 A, 60 Hz and it can be operated at the speeds of 1750/1150 rpm. It is located in the Laboratorio de Propulsion at the Instituto Tecnologico de la Laguna. [Spanish] En este trabajo de tesis se desarrollo un modelo electromagnetico lineal de un motor de induccion trifasico utilizando el Metodo de Elemento Finito en dos dimensiones, en el cual se incluye la formulacion de sistemas acoplados para los conductores delgados y gruesos presentes en el estator y rotor respectivamente. Es decir, se incluyen en el modelo las fases de alimentacion y los anillos de cortocircuito del rotor de jaula de ardilla. Las ecuaciones electricas y magneticas derivadas del modelo se resuelven de manera acoplada con el Metodo del Gradiente BiConjugado con Precondicionamiento de Cholesky Incompleto empleando el sistema de Empaquetamiento de Coordenadas, cuyo codigo se desarrollo en el lenguaje de programacion C. En este modelo se resuelve la ecuacion de difusion, mediante la cual se determinan las corrientes de Eddy que se inducen en el material conductor debido a la presencia de fuentes de alimentacion senoidales. El

  12. Electromagnetic model of a three phase induction motor using finite elements; Modelo electromagnetico de un motor de induccion trifasico usando elementos finitos

    Energy Technology Data Exchange (ETDEWEB)

    Ruvalcaba Marquez, Carlos

    2003-02-15

    This thesis shows a non-linear electromagnetic analysis of a three-phase induction machine using the two-dimensional finite element method (2D FEM). It is necessary to solve the diffusion equation to obtain the average magnetic vector potential of the FE machine model. The solution of this equation gives the induced eddy currents locally or globally inside the FE machine model. The induction machine is rated at 2.2 kw, 220 V, 60 Hz, and it can handle two different speeds, 1750/1150 rpm with a current consumption of 9.6/11.0 A, respectively. This machine is at the Laboratorio de Propulsion of the Instituto Tecnologico de la Laguna. The eddy currents induced in the conducting material appear because the FE model of the machine model is supplied by a sinusoidal current; finally, the depth penetration factor is considered on the FE mesh to achieve a better skin effect representation. [Spanish] En este trabajo de tesis se realiza un analisis electromagnetico no lineal de un motor de induccion trifasico empleando el metodo del elemento finito en dos dimensiones. De manera especifica, se calcula el potencial magnetico vectorial promedio del modelo de elemento finito del motor mediante la solucion de la ecuacion de difusion. Al resolver la ecuacion de difusion se obtiene la densidad de corrientes de eddy que se inducen ya sea en sentido local o global en el modelo del motor. El motor de induccion analizado esta disenado para operar a dos velocidades, 1750/1150 rpm, tiene una capacidad de 2.2 kW, 220 V, 9.6/11.0 A, 60 Hz, y se encuentra instalado en el Laboratorio de Propulsion del Instituto Tecnologico de la Laguna. Debido a que el modelo electromagnetico del motor de induccion es alimentado por una fuente de corriente senoidal, se tiene una induccion de corrientes de eddy en el material conductor. En el diseno de la malla se considero el factor de penetracion para lograr una mejor representacion del efecto piel.

  13. Project APhiD: A Lorenz-gauged A-Φ decomposition for parallelized computation of ultra-broadband electromagnetic induction in a fully heterogeneous Earth

    Science.gov (United States)

    Weiss, Chester J.

    2013-08-01

    An essential element for computational hypothesis testing, data inversion and experiment design for electromagnetic geophysics is a robust forward solver, capable of easily and quickly evaluating the electromagnetic response of arbitrary geologic structure. The usefulness of such a solver hinges on the balance among competing desires like ease of use, speed of forward calculation, scalability to large problems or compute clusters, parsimonious use of memory access, accuracy and by necessity, the ability to faithfully accommodate a broad range of geologic scenarios over extremes in length scale and frequency content. This is indeed a tall order. The present study addresses recent progress toward the development of a forward solver with these properties. Based on the Lorenz-gauged Helmholtz decomposition, a new finite volume solution over Cartesian model domains endowed with complex-valued electrical properties is shown to be stable over the frequency range 10-2-1010 Hz and range 10-3-105 m in length scale. Benchmark examples are drawn from magnetotellurics, exploration geophysics, geotechnical mapping and laboratory-scale analysis, showing excellent agreement with reference analytic solutions. Computational efficiency is achieved through use of a matrix-free implementation of the quasi-minimum-residual (QMR) iterative solver, which eliminates explicit storage of finite volume matrix elements in favor of "on the fly" computation as needed by the iterative Krylov sequence. Further efficiency is achieved through sparse coupling matrices between the vector and scalar potentials whose non-zero elements arise only in those parts of the model domain where the conductivity gradient is non-zero. Multi-thread parallelization in the QMR solver through OpenMP pragmas is used to reduce the computational cost of its most expensive step: the single matrix-vector product at each iteration. High-level MPI communicators farm independent processes to available compute nodes for

  14. [Measurement and study report as a part of the control system for human safety and health protection against electromagnetic fields and electromagnetic radiation (0 Hz-300 GHz)].

    Science.gov (United States)

    Aniołczyk, Halina

    2007-01-01

    The National Control System for safety and health protection against electromagnetic fields (EMF) and electromagnetic radiation (EMR) (0 Hz-300 GHz) is constantly analyzed in view of Directive 2004/40/EC. Reports on the effects of investments (at the designing stage or at the stage of looking for their localization) on the environment and measurement and study reports on the objects already existing or being put into operation are important elements of this system. These documents should meet both national and European Union's legislation requirements. The overriding goal of the control system is safety and health protection of humans against electromagnetic fields in the environment and in occupational settings. The author pays a particular attention to provisions made in directives issued by relevant ministers and to Polish standards, which should be documented in measurement and study reports published by the accredited laboratories and relating to the problems of human safety and health protection. Similar requirements are valid for the Reports. Therefore, along with measurement outcomes, the reports should include data on the EMF exposure classification at work-posts and the assessment of occupational risk resulting from EMF exposure or at least thorough data facilitating such a classification.

  15. The Use and Management of the Electromagnetic Spectrum, Part I. President's Task Force on Communications Policy. Staff Paper Seven, Part I.

    Science.gov (United States)

    Rostow, Eugene V.

    A staff paper to the President's Task Force on Communications Policy analyses the use of the electromagnetic spectrum for communications and suggests improvements. The evolution of spectrum use and its present federal management are described together with the problem of achieving efficient use in the areas of electromagnetic congestion. Criticism…

  16. Electromagnetic Interference Issues of A Wireless Power Transmission Converter

    DEFF Research Database (Denmark)

    Khazraj, Hesam; Haji Bashi, Mazaher; Silva, Filipe Miguel Faria da

    2018-01-01

    Many recent studies have focused on the inductive charging to transfer electrical power from a source to batteries without any electrical interface. The main problem with them is that inductive charging technologies may have electromagnetic compatibility (EMC) issues caused by the leakage magnetic...... for each part of the inductive charger are presented. At the first, the lowest EMI technology for wireless charging is chosen and simulated. To overcome the EMI and leakage current problems, this paper also suggests using a new passive EMI filter topology. Simulation results show the necessity...

  17. An Electromagnetic Sensor for the Autonomous Running of Visually Impaired and Blind Athletes (Part I: The Fixed Infrastructure).

    Science.gov (United States)

    Pieralisi, Marco; Di Mattia, Valentina; Petrini, Valerio; De Leo, Alfredo; Manfredi, Giovanni; Russo, Paola; Scalise, Lorenzo; Cerri, Graziano

    2017-02-14

    Sport is one of the best ways to promote the social integration of people affected by physical disability, because it helps them to increase their self-esteem by facing difficulties and overcoming their disabilities. Nowadays, a large number of sports can be easily played by visually impaired and blind athletes without any special supports, but, there are some disciplines that require the presence of a sighted guide. In this work, the attention will be focused on marathons, during which athletes with visual disorders have to be linked to the sighted guide by means of a non-stretchable elbow tether, with an evident reduction of their performance and autonomy. In this context, this paper presents a fixed electromagnetic infrastructure to equip a standard running racetrack in order to help a blind athlete to safely run without the presence of a sighted guide. The athlete runs inside an invisible hallway, just wearing a light and a comfortable sensor unit. The patented system has been homemade, designed, realized and finally tested by a blind Paralympic marathon champion with encouraging results and interesting suggestions for technical improvements. In this paper (Part I), the transmitting unit, whose main task is to generate the two magnetic fields that delimit the safe hallway, is presented and discussed.

  18. An Electromagnetic Sensor for the Autonomous Running of Visually Impaired and Blind Athletes (Part I: The Fixed Infrastructure

    Directory of Open Access Journals (Sweden)

    Marco Pieralisi

    2017-02-01

    Full Text Available Sport is one of the best ways to promote the social integration of people affected by physical disability, because it helps them to increase their self-esteem by facing difficulties and overcoming their disabilities. Nowadays, a large number of sports can be easily played by visually impaired and blind athletes without any special supports, but, there are some disciplines that require the presence of a sighted guide. In this work, the attention will be focused on marathons, during which athletes with visual disorders have to be linked to the sighted guide by means of a non-stretchable elbow tether, with an evident reduction of their performance and autonomy. In this context, this paper presents a fixed electromagnetic infrastructure to equip a standard running racetrack in order to help a blind athlete to safely run without the presence of a sighted guide. The athlete runs inside an invisible hallway, just wearing a light and a comfortable sensor unit. The patented system has been homemade, designed, realized and finally tested by a blind Paralympic marathon champion with encouraging results and interesting suggestions for technical improvements. In this paper (Part I, the transmitting unit, whose main task is to generate the two magnetic fields that delimit the safe hallway, is presented and discussed.

  19. Hybrid synchronous motor electromagnetic torque research

    Directory of Open Access Journals (Sweden)

    Suvorkova Elena E.

    2014-01-01

    Full Text Available Electromagnetic field distribution models in reluctance and permanent magnet parts were made by means of Elcut. Dependences of electromagnetic torque on torque angle were obtained.

  20. Radiofrequency identification and medical devices: the regulatory framework on electromagnetic compatibility. Part II: active implantable medical devices.

    Science.gov (United States)

    Mattei, Eugenio; Censi, Federica; Triventi, Michele; Bartolini, Pietro; Calcagnini, Giovanni

    2012-05-01

    The number and the types of electromagnetic emitters to which patients with active implantable medical devices (AIMD) are exposed to in their daily activities have proliferated over the last decade. Radiofrequency identification (RFID) is an example of wireless technology applied in many fields. The interaction between RFID emitters and AIMD is an important issue for patients, industry and regulators, because of the risks associated with such interactions. The different AIMDs refer to different standards that address the electromagnetic immunity issue in different ways. Indeed, different test setups, immunity levels and rationales are used to guarantee that AIMDs are immune to electromagnetic nonionizing radiation. In this article, the regulatory framework concerning electromagnetic compatibility between RFID systems and AIMDs is analyzed to understand whether and how the application of the current AIMD standards allows for the effective control of the possible risks associated with RFID technology.

  1. Electromagnetic Waves

    DEFF Research Database (Denmark)

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis...

  2. Electromagnetic compatibility overview

    Science.gov (United States)

    Davis, K. C.

    1980-01-01

    An assessment of the electromagnetic compatibility impact of the Satellite Power System is discussed. The discussion is divided into two parts: determination of the emission expected from SPS including their spatial and spectral distributions, and evaluation of the impact of such emissions on electromagnetic systems including considerations of means for mitigating effects.

  3. Electromagnetic Waves

    OpenAIRE

    Blok, H.; van den Berg, P.M.

    2011-01-01

    This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, etc.

  4. Calculation of the electromagnetic fields in electric machines through the use of the finite element. Algorithms for the solution of induction problems. Pt. 3; Calculo de campos electromagneticos en maquinas electricas mediante elemento finito. Algoritmos para la solucion de problemas de induccion. Pt. 3

    Energy Technology Data Exchange (ETDEWEB)

    Rosales, Mario F. [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    This article is based in the electromagnetic modeling presented in the first part of the series for the indirect solution of partial differential equations. Magnetic systems in closed regions with moving or axial symmetry, whose total current density is partially known (induction problems) are considered. Includes the ability to deal with means in movement and a sinusoidal behavior for the source density current is assumed. Some algorithms are developed that are implanted in the software CALIIE-2D of the Instituto de Investigaciones Electricas (IIE) to obtain the numerical solutions of these problems. The basic systems of algebraic equations are obtained through the application of the Galerkin method in the discreteness of the finite element with first order triangular elements. [Espanol] Este articulo se basa en la modelacion electromagnetica presentada en la primera parte de la serie y en el planteamiento proporcionado en la segunda parte para la solucion indirecta de ecuaciones diferenciales parciales. Se consideran sistemas magneticos en regiones cerradas con simetria traslacional o axial, cuya densidad de corriente total es parcialmente conocida (problemas de induccion). Incluye la capacidad para tratar medios con movimiento y se supone un comportamiento senoidal para la densidad de corriente fuente. Se desarrollan los algoritmos que se implantan en el programa de computo CALIIE-2D del Instituto de Investigaciones Electricas (IIE) para obtener las soluciones numericas de estos problemas. Los sistemas basicos de ecuaciones algebraicas se obtienen mediante la aplicacion del metodo de Galerkin en la discretizacion de elemento finito con elementos triangulares de primer orden.

  5. Electromagnetic clutches and couplings

    CERN Document Server

    Vorob'Yeva, T M; Fry, D W; Higinbotham, W

    2013-01-01

    Electromagnetic Clutches and Couplings contains a detailed description of U.S.S.R. electromagnetic friction clutches, magnetic couplings, and magnetic particle couplings. This book is divided into four chapters. The first chapter discusses the design and construction of magnetic (solenoid-operated) couplings, which are very quick-acting devices and used in low power high-speed servo-systems. Chapter 2 describes the possible fields of application, design, construction, and utilization of magnetic particle couplings. The aspects of construction, design, and utilization of induction clutches (sli

  6. Oxidative stress and apoptosis induction in human thyroid carcinoma cells exposed to the essential oil from Pistacia lentiscus aerial parts.

    Directory of Open Access Journals (Sweden)

    Simona Catalani

    Full Text Available Essential oils from the aerial parts (leaves, twigs and berries of Pistacia lentiscus (PLEO have been well characterized for their antibacterial and anti-inflammatory properties; however, poor information exists on their potential anticancer activity.Increasing concentrations of PLEO (0.01-0.1% v/v, 80-800 μg/ml were administered to a wide variety of cultured cancer cells from breast, cervix, colon, liver, lung, prostate, and thyroid carcinomas. Fibroblasts were also included as healthy control cells. Cell viability was monitored by WST-8 assay up to 72 hours after PLEO administration. The intracellular formation of reactive oxygen species (ROS, the induction of apoptosis, and the enhancement of chemotherapeutic drug cytotoxicity by PLEO were further investigated in the most responsive cancer cell line.A dose-dependent reduction of tumor cell viability was observed upon PLEO exposure; while no cytotoxic effect was revealed in healthy fibroblasts. FTC-133 thyroid cancer cells were found to be the most sensitive cells to PLEO treatment; accordingly, an intracellular accumulation of ROS and an activation of both the extrinsic and intrinsic apoptotic pathways were evidenced in FTC-133 cells after PLEO administration. Furthermore, the cytotoxic effect of the antineoplastic drugs cisplatin, 5-fluorouracil and etoposide was enhanced in PLEO-exposed FTC-133 cells.Taking into account its mode of action, PLEO might be considered as a promising source of natural antitumor agents which might have therapeutic potential in integrated oncology.

  7. Oxidative stress and apoptosis induction in human thyroid carcinoma cells exposed to the essential oil from Pistacia lentiscus aerial parts.

    Science.gov (United States)

    Catalani, Simona; Palma, Francesco; Battistelli, Serafina; Benedetti, Serena

    2017-01-01

    Essential oils from the aerial parts (leaves, twigs and berries) of Pistacia lentiscus (PLEO) have been well characterized for their antibacterial and anti-inflammatory properties; however, poor information exists on their potential anticancer activity. Increasing concentrations of PLEO (0.01-0.1% v/v, 80-800 μg/ml) were administered to a wide variety of cultured cancer cells from breast, cervix, colon, liver, lung, prostate, and thyroid carcinomas. Fibroblasts were also included as healthy control cells. Cell viability was monitored by WST-8 assay up to 72 hours after PLEO administration. The intracellular formation of reactive oxygen species (ROS), the induction of apoptosis, and the enhancement of chemotherapeutic drug cytotoxicity by PLEO were further investigated in the most responsive cancer cell line. A dose-dependent reduction of tumor cell viability was observed upon PLEO exposure; while no cytotoxic effect was revealed in healthy fibroblasts. FTC-133 thyroid cancer cells were found to be the most sensitive cells to PLEO treatment; accordingly, an intracellular accumulation of ROS and an activation of both the extrinsic and intrinsic apoptotic pathways were evidenced in FTC-133 cells after PLEO administration. Furthermore, the cytotoxic effect of the antineoplastic drugs cisplatin, 5-fluorouracil and etoposide was enhanced in PLEO-exposed FTC-133 cells. Taking into account its mode of action, PLEO might be considered as a promising source of natural antitumor agents which might have therapeutic potential in integrated oncology.

  8. Implications of various intensities of radio frequency electromagnetic radiation (462 MHz in the induction of oxidative stress during the germination of Hippophae rhamnoides seeds

    Directory of Open Access Journals (Sweden)

    Calin Lucian Maniu

    2010-02-01

    Full Text Available The data accumulated by now shows that the topic of biological effects of electromagnetic radiation is far from being exhausted. Is undoubtedly that a non-ionizing radiation field maintained on a biological entity has some effects on it. To try shaping issues regarding this, this work aims to study the impact of radiation generated by an emission-reception radio station that emits on 462.6875 MHz frequency. For this purpose, were used Hippophae rhamnoides L. seeds which germinated in the laboratory, under controlled conditions, concentrically arranged around the radiation source, in which case electromagnetic radiation has a different impact. Seed germination lasted 35 days, while the device has continuously worked, and the seeds were constantly irradiated. It was precisely measured the intensity of the magnetic component of the field in all places where the seeds were placed for germination. It was calculated the percentage of germination and it was determined the enzyme activity involved in eliminating the oxidative stress effects. It was found significant variations of the parameters mentioned above in conjunction with the radiation intensity depending on the distance from the source.

  9. Improving the electromagnetic compatibility of track circuits with electric rolling stock of double power supply with induction traction motors and electrictraction network

    Directory of Open Access Journals (Sweden)

    N.G. Visin

    2012-04-01

    Full Text Available In this article the research results of many authors on the effect of current interference from the existing electric rolling stock with induction traction motors (ITM on the track circuits and the possibility of exceeding the train traffic safety standards are used. The new promising scheme of power circuit for electric locomotive of double power supply with an ITM applying the intermediary high-frequency transformer for reducing significantly the interference effects to SCB and communication devices is developed.

  10. Electromagnet. Elektromagnet

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Amaya, N.; Weiss, F.; Schmitt, A.

    1991-04-18

    An electromagnet, particularly for use in switching valves for the direct control of a fuel injection quantity on fuel injection pumps, has a magnet pot (25) made of soft magnetic material, an annular excitation coil (30) and a magnet armature (29), which is situated with a working air gap in front of the magnet pot (25). To improve the dynamic behaviour of the electromagnet (20), ie: to achieve extremely low switching times with simple manufacture of the magnetic circuit, the magnet pot (25) and/or the magnet armature (29) made as a solid part is provided with an even number of at least four radial slots (41), which pass through the magnet pot (25) or the magnet armature (29) over their whole axial length. Successive radial slots (41a, 41b) extend alternately from the outside or from the inside jacket surface (311 or 321) to near the inside or the outside jacket surface (321 or 311) respectively and end there, always leaving a bar of material (42 or 43).

  11. Study of the Plasma Turbulence Dynamics by Measurements of Diagnostic Stimulated Electromagnetic Emission. Part II. Results of Numerical Simulation

    Science.gov (United States)

    Sergeev, E. N.; Grach, S. M.

    2017-07-01

    The data on measured dynamic characteristics of diagnostic stimulated electromagnetic emission (SEE) of the ionosphere are presented. Numerical simulations of the SEE evolution within the framework of a theoretical model of the broad-continuum SEE feature with the use of improved (3D) empirical model of the spatial spectrum of artificial irregularities of the HF pumped ionospheric plasma are performed and compared with the measurement data. Possible applications of such a comparison for determining the spectrum parameters and studying the evolution of the geomagnetic field-aligned artificial irregularities (striations) are discussed. It is concluded that changes in the intensity and spectrum shape of the striations, mainly for transverse scales l ⊥ 2-18 m, play the decisive role in the observed variations of the magnitude and temporal characteristics of the overshoot effect (formation of the intensity maximum followed by the suppression of the ionospheric SEE intensity).

  12. Induction accelerators

    CERN Document Server

    Takayama, Ken

    2011-01-01

    A broad class of accelerators rests on the induction principle whereby the accelerating electrical fields are generated by time-varying magnetic fluxes. Particularly suitable for the transport of bright and high-intensity beams of electrons, protons or heavy ions in any geometry (linear or circular) the research and development of induction accelerators is a thriving subfield of accelerator physics. This text is the first comprehensive account of both the fundamentals and the state of the art about the modern conceptual design and implementation of such devices. Accordingly, the first part of the book is devoted to the essential features of and key technologies used for induction accelerators at a level suitable for postgraduate students and newcomers to the field. Subsequent chapters deal with more specialized and advanced topics.

  13. Induction électromagnétique dans la terre. Problème à trois dimensions. Modèles réduits Electromagnetic Induction in the Ground. Three-Dimensional Problems. Scale Models

    Directory of Open Access Journals (Sweden)

    Launay L.

    2006-11-01

    Full Text Available L'interprétation des phénomènes électromagnétiques naturels conduit à proposer relativement à la conductivité électrique des structures théoriques se prêtant au calcul ou à la simulation expérimentale. Pour traiter les cas tridimensionnels, il convient de procéder par réduction analogique. Un mode de réalisation dit de « symétrie » permet d'obtenir la résolution quantitative de tels problèmes magnétotelluriques. II s'appuie sur le principe des images électriques pour représenter un substratum lan infiniment conducteur. A propos de ces modèles réduits, la technique à utiliser pour satisfaire aux conditions exigées par la symétrie a été précisée par études successives des éléments inducteurs, de la maquette et des circuits de mesure. Les expériences menées ont montré la validité du procédé et certaines applications ont mis en évidence différents aspects de « l'effet de bord ». For interpreting natural electromagnetic phenomena, theoretical structures suitable for calculating or experimental simulation have been proposed with regard to electrical conductivity. For treating three-dimensional cases, analog reduction cari be used. A procedural mode called « symmetry » cari be used for quantitatively solving such magnetotelluric problems. It is based on the principle of electrical images to represent an infinitely conducting substratum plane. With regard to such scale models, the technique ta be used to fulfill the conditions required by symmetry has been specified by successive analyses of the inductor elements, of the model and of the measuring circuits. Experiments have been carried out to show the validity of the process, and some applications have revealed various aspects of the K edge effect».

  14. Case Study Regarding the Design of a Direct Current Electromagnet for the MIG Welding of Metallic Materials Part I: Description of the Welding Methods and Preliminary Calculus of the Electromagnet

    Directory of Open Access Journals (Sweden)

    Tudorel Ene

    2016-10-01

    Full Text Available The paper refers to the design of a direct current electromagnet, located on the head of a swan neck welding gun of a MIG welding equipment and used for magnetising the rotation space of two additional electric arches, in order to preheat the electrode wire and of the protective gas, partially turned into plasma jet. One describes the MIG welding method in which the electromagnet is used as well as its preliminary calculus.

  15. Electromagnetic Attraction.

    Science.gov (United States)

    Milson, James L.

    1990-01-01

    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)

  16. Techniques in Gas-Phase Thermolyses. Part 6. Pulse Pyrolysis: Gas Kinetic Studies in an Inductively Heated Flow Reactor

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Bo, P.; Carlsen, Lars

    1985-01-01

    A prototype of an inductively heated flow reactor for gas kinetic studies is presented. The applicability of the system, which is based on a direct coupling between the reactor and the ion source of a mass spectrometer, is illustrated by investigations of a series of simple bond fission reactions....... The method permits the direct determination of low-pressure rate constants, the transformation to high-pressure values, and correspondingly evaluation of activation parameters, being derived by means of an empirical effective temperature approach.......A prototype of an inductively heated flow reactor for gas kinetic studies is presented. The applicability of the system, which is based on a direct coupling between the reactor and the ion source of a mass spectrometer, is illustrated by investigations of a series of simple bond fission reactions...

  17. Electromagnetic mapping of buried paleochannels in eastern Abu Dhabi Emirate, U.A.E.

    Science.gov (United States)

    Fitterman, D.V.; Menges, C.M.; Al Kamali, A.M.; Essa, Jama F.

    1991-01-01

    Transient electromagnetic soundings and terrain conductivity meter measurements were used to map paleochannel geometry in the Al Jaww Plain of eastern Abu Dhabi Emirate, U.A.E. as part of an integrated hydrogeologic study of the Quaternary alluvial aquifer system. Initial interpretation of the data without benefit of well log information was able to map the depth to a conductive clay layer of Tertiary age that forms the base of the aquifer. Comparison of the results with induction logs reveals that a resistive zone exists that was incorporated into the interpretation and its lateral extent mapped with the transient electromagnetic sounding data. ?? 1991.

  18. Electromagnetic interactions

    CERN Document Server

    Bosanac, Slobodan Danko

    2016-01-01

    This book is devoted to theoretical methods used in the extreme circumstances of very strong electromagnetic fields. The development of high power lasers, ultrafast processes, manipulation of electromagnetic fields and the use of very fast charged particles interacting with other charges requires an adequate theoretical description. Because of the very strong electromagnetic field, traditional theoretical approaches, which have primarily a perturbative character, have to be replaced by descriptions going beyond them. In the book an extension of the semi-classical radiation theory and classical dynamics for particles is performed to analyze single charged atoms and dipoles submitted to electromagnetic pulses. Special attention is given to the important problem of field reaction and controlling dynamics of charges by an electromagnetic field.

  19. Inductive dielectric analyzer

    Science.gov (United States)

    Agranovich, Daniel; Polygalov, Eugene; Popov, Ivan; Ben Ishai, Paul; Feldman, Yuri

    2017-03-01

    One of the approaches to bypass the problem of electrode polarization in dielectric measurements is the free electrode method. The advantage of this technique is that, the probing electric field in the material is not supplied by contact electrodes, but rather by electromagnetic induction. We have designed an inductive dielectric analyzer based on a sensor comprising two concentric toroidal coils. In this work, we present an analytic derivation of the relationship between the impedance measured by the sensor and the complex dielectric permittivity of the sample. The obtained relationship was successfully employed to measure the dielectric permittivity and conductivity of various alcohols and aqueous salt solutions.

  20. Ascorbic acid partly antagonizes resveratrol mediated heme oxygenase-1 but not paraoxonase-1 induction in cultured hepatocytes - role of the redox-regulated transcription factor Nrf2

    Directory of Open Access Journals (Sweden)

    Hori Osamu

    2011-01-01

    Full Text Available Abstract Background Both resveratrol and vitamin C (ascorbic acid are frequently used in complementary and alternative medicine. However, little is known about the underlying mechanisms for potential health benefits of resveratrol and its interactions with ascorbic acid. Methods The antioxidant enzymes heme oxygenase-1 and paraoxonase-1 were analysed for their mRNA and protein levels in HUH7 liver cells treated with 10 and 25 μmol/l resveratrol in the absence and presence of 100 and 1000 μmol/l ascorbic acid. Additionally the transactivation of the transcription factor Nrf2 and paraoxonase-1 were determined by reporter gene assays. Results Here, we demonstrate that resveratrol induces the antioxidant enzymes heme oxygenase-1 and paraoxonase-1 in cultured hepatocytes. Heme oxygenase-1 induction by resveratrol was accompanied by an increase in Nrf2 transactivation. Resveratrol mediated Nrf2 transactivation as well as heme oxygenase-1 induction were partly antagonized by 1000 μmol/l ascorbic acid. Conclusions Unlike heme oxygenase-1 (which is highly regulated by Nrf2 paraoxonase-1 (which exhibits fewer ARE/Nrf2 binding sites in its promoter induction by resveratrol was not counteracted by ascorbic acid. Addition of resveratrol to the cell culture medium produced relatively low levels of hydrogen peroxide which may be a positive hormetic redox-signal for Nrf2 dependent gene expression thereby driving heme oxygenase-1 induction. However, high concentrations of ascorbic acid manifold increased hydrogen peroxide production in the cell culture medium which may be a stress signal thereby disrupting the Nrf2 signalling pathway.

  1. Progress in antenna coupled kinetic inductance detectors

    NARCIS (Netherlands)

    Baryshev, A.; Baselmans, J.J.A.; Freni, A.; Gerini, G.; Hoevers, H.; Iacono, A.; Neto, A.

    2011-01-01

    This paper describes the combined Dutch efforts toward the development of large wideband focal plane array receivers based on kinetic inductance detectors (KIDs). Taking into account strict electromagnetic and detector sensitivity requirements for future ground and space based observatories, this

  2. Engineering electromagnetics

    CERN Document Server

    Thomas, David T; Hartnett, James P; Hughes, William F

    1973-01-01

    The applications involving electromagnetic fields are so pervasive that it is difficult to estimate their contribution to the industrial output: generation of electricity, power transmission lines, electric motors, actuators, relays, radio, TV and microwave transmission and reception, magnetic storage, and even the mundane little magnet used to hold a paper note on the refrigerator are all electromagnetic in nature. One would be hard pressed to find a device that works without relaying on any electromagnetic principle or effect. This text provides a good theoretical understanding of the electromagnetic field equations but also treats a large number of applications. In fact, no topic is presented unless it is directly applicable to engineering design or unless it is needed for the understanding of another topic. In electrostatics, for example, the text includes discussions of photocopying, ink-jet printing, electrostatic separation and deposition, sandpaper production, paint spraying, and powder coating. In ma...

  3. Electromagnetic Landscape

    DEFF Research Database (Denmark)

    Cermak, Daniel; Okutsu, Ayaka; Jørgensen, Stina Marie Hasse

    2015-01-01

    Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015.......Daniel Cermak-Sassenrath, Ayaka Okutsu, Stina Hasse. Electromagnetic Landscape - In-between Signal, Noise and Environment. Installation and artist talk. 21th International Symposium on Electronic Art (ISEA) 2015, Vancouver, CAN, Aug 14-18, 2015....

  4. The theory of electromagnetism

    CERN Document Server

    Jones, D S

    1964-01-01

    The Theory of the Electomagnetism covers the behavior of electromagnetic fields and those parts of applied mathematics necessary to discover this behavior. This book is composed of 11 chapters that emphasize the Maxwell's equations. The first chapter is concerned with the general properties of solutions of Maxwell's equations in matter, which has certain macroscopic properties. The succeeding chapters consider specific problems in electromagnetism, including the determination of the field produced by a variable charge, first in isolation and then in the surface distributions of an antenna. The

  5. Volcano-electromagnetic effects

    Science.gov (United States)

    Johnston, Malcolm J. S.

    2007-01-01

    Volcano-electromagnetic effects—electromagnetic (EM) signals generated by volcanic activity—derive from a variety of physical processes. These include piezomagnetic effects, electrokinetic effects, fluid vaporization, thermal demagnetization/remagnetization, resistivity changes, thermochemical effects, magnetohydrodynamic effects, and blast-excited traveling ionospheric disturbances (TIDs). Identification of different physical processes and their interdependence is often possible with multiparameter monitoring, now common on volcanoes, since many of these processes occur with different timescales and some are simultaneously identified in other geophysical data (deformation, seismic, gas, ionospheric disturbances, etc.). EM monitoring plays an important part in understanding these processes.

  6. Aircraft electromagnetic compatibility

    Science.gov (United States)

    Clarke, Clifton A.; Larsen, William E.

    1987-06-01

    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.

  7. Aircraft electromagnetic compatibility

    Science.gov (United States)

    Clarke, Clifton A.; Larsen, William E.

    1987-01-01

    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.

  8. Improved Electromagnetic Brake

    Science.gov (United States)

    Martin, Toby B.

    2004-01-01

    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

  9. Portable Electromagnetic Induction Sensor with Integrated Positioning

    Science.gov (United States)

    2013-08-20

    of our advanced EMI codes we conducted comparisons between actual and measured data for a permeable 4-inch-diameter sphere. The sphere was placed 36...of Elkton Series type soil[53]. The Elkton Series consist of very deep, slowly permeable , poorly drained soils. These soils formed in silty aeolian...A 105-m m U X O and a box of nails are in- terrogated by the sensoron the 5 5 grid of Fig.8.Tw o separate experim ents, involving different box/U X O

  10. Investigation of an Electromagnetic Induction Sensor

    Science.gov (United States)

    2011-12-01

    Osborne and G. K. Smyth, “A modified Prony algorithm for expo- nential function fitting,” SIAM J. Sci. Comput., vol. 16, no. 1, pp. 119–138, Jan. 1995...Osborne, M. R. and Smyth, G. K., “A modified Prony algorithm for exponential function fitting,” SIAM J. Sci. Comp., vol. 16, no. 1, pp. 119–138, 1995. [26

  11. Electromagnetic Induction: A Computer-Assisted Experiment

    Science.gov (United States)

    Fredrickson, J. E.; Moreland, L.

    1972-01-01

    By using minimal equipment it is possible to demonstrate Faraday's Law. An electronic desk calculator enables sophomore students to solve a difficult mathematical expression for the induced EMF. Polaroid pictures of the plot of induced EMF, together with the computer facility, enables students to make comparisons. (PS)

  12. TESTING OF FRAMED STRUCTURE PARTS OF COMPACT MUON SOLENOID BY NONDESTRUCTIVE METHOD

    Directory of Open Access Journals (Sweden)

    L. Larchenkov

    2013-01-01

    Full Text Available Suspension parts of a compact muon solenoid for Large Hadron Collider have been tested in the paper. The paper describes a steady-state and cyclic “tension-compression” load created by superconducting electromagnet with energy of 3 GJ and magnetic induction of 4 tesla. A nondestructive testing method has been applied in the paper.

  13. Labor Induction

    Science.gov (United States)

    ... QUESTIONS FAQ154 LABOR, DELIVERY, AND POSTPARTUM CARE Labor Induction • What is labor induction? • Why is labor induced? • What is the Bishop ... oxytocin? • What are the risks associated with labor induction? • Is labor induction always effective? •Glossary What is ...

  14. A System for Electromagnetic Field Conversion

    DEFF Research Database (Denmark)

    2003-01-01

    A system is provided for conversion of a first electromagnetic field into a desired second electromagnetic field, for example for coupling modes between waveguides or into microstructured waveguides. The system comprises a complex spatial electromagnetic field converter that is positioned...... for reception of at least a part of the first electromagnetic field and that is adapted for conversion of the received field into the desired electromagnetic field, and wherein at least one of the first and second fields matches a mode of a microstructured waveguide. It is an important advantage of the present...

  15. Electromagnetic Compatibility of Devices on Hybrid Electromagnetic Components

    Science.gov (United States)

    Konesev, S. G.; Khazieva, R. T.; Kirillov, R. V.; Gainutdinov, I. Z.; Kondratyev, E. Y.

    2018-01-01

    There is a general tendency to reduce the weight and dimensions, the consumption of conductive and electrical insulating materials, increase the reliability and energy efficiency of electrical devices. In recent years, designers have been actively developing devices based on hybrid electromagnetic components (HEMC) such as inductive-capacitive converters (ICC), voltages pulse generators (VPG), secondary power supplies (SPS), capacitive storage devices (CSD), induction heating systems (IHS). Sources of power supplies of similar electrical devices contain, as a rule, links of increased frequency and function in key (pulse) modes, which leads to an increase in electromagnetic interference (EMI). Nonlinear and periodic (impulse) loads, non-sinusoidal (pulsation) of the electromotive force and nonlinearity of the internal parameters of the source and input circuits of consumers distort the shape of the input voltage lead to an increase in thermal losses from the higher harmonic currents, aging of the insulation, increase in the weight of the power supply filter units, resonance at higher harmonics. The most important task is to analyze the operation of electrotechnical devices based on HEMC from the point of view of creating EMIs and assessing their electromagnetic compatibility (EMC) with power supply systems (PSS). The article presents the results of research on the operation of an IHS, the operation principle of a secondary power supply source of which is based on the operation of a half-bridge autonomous inverter, the switching circuit of which is made in the form of a HEMC, called the «multifunctional integrated electromagnetic component»" (MIEC).

  16. Electromagnetic Landscape

    DEFF Research Database (Denmark)

    Cermak, Daniel; Okutsu, Ayaka; Hasse, Stina

    2015-01-01

    Electromagnetic Landscape demonstrates in direct, tangible and immediate ways effects of the disruption of the familiar. An ubiquitous technological medium, FM radio, is turned into an alien and unfamiliar one. Audience participation, the environment, radio signals and noise create a site...

  17. Electromagnetic Fields

    Science.gov (United States)

    ... cancers. Studies in adults did not prove that EMF exposure causes cancer. Some people worry that wireless and cellular phones cause cancer or other health problems. The phones do give off radio-frequency energy (RF), a form of electromagnetic radiation. So far, scientific evidence has not found a ...

  18. AN ANTHOLOGY OF THE DISTINGUISHED ACHIEVEMENTS IN SCIENCE AND TECHNIQUE. PART 33: ELECTROMAGNETIC COMPATIBILITY AND PROTECTION FROM ACTION OF POWERFUL ELECTROMAGNETIC INTERFERENCE OF RADIOELECTRONIC, ELECTRICAL ENGINEERING AND ELECTRIC POWER EQUIPMENT

    Directory of Open Access Journals (Sweden)

    M.I. Baranov

    2016-09-01

    Full Text Available Purpose. Implementation of brief analytical review of basic scientific and technical achievements in area of electromagnetic compatibility (EMC and protection from destabilizing and striking action of powerful electromagnetic interference (PEMI of natural and artificial origin of radioelectronic, electrical engineering and electric power equipment. Methodology. Scientific methods of collection, analysis and analytical treatment of scientific and technical information in a sphere EMC and such areas of knowledge’s as radioelectronics, electrical engineering and electric power engineering. Results. A brief scientific and technical review is resulted modern positions problems EMC and protection of equipment from action on them PEMI. It is shown that PEMI can result in failures in-process and death of examined equipment. Annual harm in the industrially developed countries of the world from the striking affecting of PEMI modern equipment with integral microcircuits and semiconductor devices can make ten of milliards of USD. The basic methods of protection of equipment are resulted from PEMI and protective devices (PD, intended for the increase of effectiveness of modern equipment to the action of external PEMI. Principles of work of the resulted PD and their basic technical descriptions are described. Originality. On the basis of materials of scientific monographs, journal publications, normative documents and internet-reports systematization of basic PD, in-use presently in an area EMC and protection of different equipment from the hazard agency of external PEMI is executed. Practical value. Popularization of scientific and technical knowledge’s in an area EMC and protection of modern equipment from a dangerous action on them PEMI. Formulation of important for society scientific and technical problems and tasks, arising up in an area EMC and providing of the reliable functioning of modern equipment in power electromagnetic interference.

  19. INVESTIGATION OF ELECTROMAGNETIC FIELDS IN RESIDENTIAL AREAS

    Directory of Open Access Journals (Sweden)

    Dušan MEDVEĎ

    2017-09-01

    Full Text Available This article is devoted to investigation of impact of electromagnetic fields around the electrical equipment used in a residential area and their impact on the human body. This paper was based on sets of measurements of magnetic induction B with magnetometer and on computational simulations in ANSYS for particular appliances often used in household. The results from measurements and simulations led to setting out the recommendations for practical action in the form of elimination of harmful electromagnetic radiation.

  20. TORO II: A finite element computer program for nonlinear quasi-static problems in electromagnetics: Part 2, User`s manual

    Energy Technology Data Exchange (ETDEWEB)

    Gartling, D.K.

    1996-05-01

    User instructions are given for the finite element, electromagnetics program, TORO II. The theoretical background and numerical methods used in the program are documented in SAND95-2472. The present document also describes a number of example problems that have been analyzed with the code and provides sample input files for typical simulations. 20 refs., 34 figs., 3 tabs.

  1. Gravitation and electromagnetism

    OpenAIRE

    Sidharth, B. G.

    2002-01-01

    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...

  2. Computational Electromagnetics

    CERN Document Server

    Rylander, Thomas; Bondeson, Anders

    2013-01-01

    Computational Electromagnetics is a young and growing discipline, expanding as a result of the steadily increasing demand for software for the design and analysis of electrical devices. This book introduces three of the most popular numerical methods for simulating electromagnetic fields: the finite difference method, the finite element method and the method of moments. In particular it focuses on how these methods are used to obtain valid approximations to the solutions of Maxwell's equations, using, for example, "staggered grids" and "edge elements." The main goal of the book is to make the reader aware of different sources of errors in numerical computations, and also to provide the tools for assessing the accuracy of numerical methods and their solutions. To reach this goal, convergence analysis, extrapolation, von Neumann stability analysis, and dispersion analysis are introduced and used frequently throughout the book. Another major goal of the book is to provide students with enough practical understan...

  3. Introduction of organic/hydro-organic matrices in inductively coupled plasma optical emission spectrometry and mass spectrometry: a tutorial review. Part II. Practical considerations.

    Science.gov (United States)

    Leclercq, Amélie; Nonell, Anthony; Todolí Torró, José Luis; Bresson, Carole; Vio, Laurent; Vercouter, Thomas; Chartier, Frédéric

    2015-07-23

    Inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are increasingly used to carry out analyses in organic/hydro-organic matrices. The introduction of such matrices into ICP sources is particularly challenging and can be the cause of numerous drawbacks. This tutorial review, divided in two parts, explores the rich literature related to the introduction of organic/hydro-organic matrices in ICP sources. Part I provided theoretical considerations associated with the physico-chemical properties of such matrices, in an attempt to understand the induced phenomena. Part II of this tutorial review is dedicated to more practical considerations on instrumentation, instrumental and operating parameters, as well as analytical strategies for elemental quantification in such matrices. Two important issues are addressed in this part: the first concerns the instrumentation and optimization of instrumental and operating parameters, pointing out (i) the description, benefits and drawbacks of different kinds of nebulization and desolvation devices and the impact of more specific instrumental parameters such as the injector characteristics and the material used for the cone; and, (ii) the optimization of operating parameters, for both ICP-OES and ICP-MS. Even if it is at the margin of this tutorial review, Electrothermal Vaporization and Laser Ablation will also be shortly described. The second issue is devoted to the analytical strategies for elemental quantification in such matrices, with particular insight into the isotope dilution technique, particularly used in speciation analysis by ICP-coupled separation techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Electromagnetic Reciprocity.

    Energy Technology Data Exchange (ETDEWEB)

    Aldridge, David F.

    2014-11-01

    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

  5. Electromagnetic theory for electromagnetic compatibility engineers

    CERN Document Server

    Toh, Tze-Chuen

    2013-01-01

    Engineers and scientists who develop and install electronic devices and circuits need to have a solid understanding of electromagnetic theory and the electromagnetic behavior of devices and circuits. In particular, they must be well-versed in electromagnetic compatibility, which minimizes and controls the side effects of interconnected electric devices. Designed to entice the practical engineer to explore some worthwhile mathematical methods, and to reorient the theoretical scientist to industrial applications, Electromagnetic Theory for Electromagnetic Compatibility Engineers is based on the

  6. Engineering electromagnetics

    CERN Document Server

    Ida, Nathan

    2015-01-01

    This book provides students with a thorough theoretical understanding of electromagnetic field equations and it also treats a large number of applications. The text is a comprehensive two-semester textbook. The work treats most topics in two steps – a short, introductory chapter followed by a second chapter with in-depth extensive treatment; between 10 to 30 applications per topic; examples and exercises throughout the book; experiments, problems  and summaries.   The new edition includes: updated end of chapter problems; a new introduction to electromagnetics based on behavior of charges; a new section on units; MATLAB tools for solution of problems and demonstration of subjects; most chapters include a summary. The book is an undergraduate textbook at the Junior level, intended for required classes in electromagnetics. It is written in simple terms with all details of derivations included and all steps in solutions listed. It requires little beyond basic calculus and can be used for self-study. The weal...

  7. Using Some Coupled Numerical Models in Problems of Designing an Inductive Electrothermal Equipment

    Directory of Open Access Journals (Sweden)

    LEUCA Teodor

    2014-05-01

    Full Text Available This paper focuses on the numerical modeling of coupling the electromagnetic and the thermal field, in the process of inductive heating, for inductive electrothermal equipments. Numerical results are carried out by using a FLUX2D application.

  8. Electromagnetic microactuators

    Science.gov (United States)

    Büttgenbach, S.; Al-Halhouli, A. T.; Feldmann, M.; Seidemann, V.; Waldschik, A.

    2013-05-01

    High precision microactuators have become key elements for many applications of MEMS, for example for positioning and handling systems as well as for microfluidic devices. Electromagnetic microactuators exhibit considerable benefits such as high forces, large deflections, low input impedances and thus, the involvement of only low voltages. Most of the magnetic microactuators developed so far are based on the variable reluctance principle and use soft magnetic materials. Since the driving force of such actuators is proportional to their volume, they require structures with rather great heights and aspect ratios. Therefore, the development of new photo resists, which allow UV exposure of thick layers of resist, has been essential for the advancement of variable reluctance microactuators. On the other hand, hard magnetic materials have the potential for larger forces and larger deflections. Accordingly, polymer magnets, in which micro particles of hard magnetic material are suspended in a polymer matrix, have been used to fabricate permanent magnet microactuators. In this paper we give an overview of sophisticated electromagnetic microactuators which have been developed in our laboratory in the framework of the Collaborative Research Center "Design and Manufacturing of Active Microsystems". In particular, concept, fabrication and test of variable reluctance micro stepper motors, of permanent magnet synchronous micromotors and of microactuators based on the Lorentz force principle will be described. Special emphasis will be given to applications in lab-on-chip systems.

  9. Introduction of organic/hydro-organic matrices in inductively coupled plasma optical emission spectrometry and mass spectrometry: A tutorial review. Part II. Practical considerations

    Energy Technology Data Exchange (ETDEWEB)

    Leclercq, Amélie, E-mail: amelie.leclercq@cea.fr [CEA Saclay, DEN, DANS, DPC, SEARS, Laboratoire de développement Analytique Nucléaire Isotopique et Elémentaire, 91191 Gif-sur-Yvette (France); Nonell, Anthony, E-mail: anthony.nonell@cea.fr [CEA Saclay, DEN, DANS, DPC, SEARS, Laboratoire de développement Analytique Nucléaire Isotopique et Elémentaire, 91191 Gif-sur-Yvette (France); Todolí Torró, José Luis, E-mail: jose.todoli@ua.es [Universidad de Alicante, Departamento de Quimica Analitica, Nutricion y Bromatología, Ap. de Correos, 99, 03080 Alicante (Spain); Bresson, Carole, E-mail: carole.bresson@cea.fr [CEA Saclay, DEN, DANS, DPC, SEARS, Laboratoire de développement Analytique Nucléaire Isotopique et Elémentaire, 91191 Gif-sur-Yvette (France); Vio, Laurent, E-mail: laurent.vio@cea.fr [CEA Saclay, DEN, DANS, DPC, SEARS, Laboratoire de développement Analytique Nucléaire Isotopique et Elémentaire, 91191 Gif-sur-Yvette (France); Vercouter, Thomas, E-mail: thomas.vercouter@cea.fr [CEA Saclay, DEN, DANS, DPC, SEARS, Laboratoire de développement Analytique Nucléaire Isotopique et Elémentaire, 91191 Gif-sur-Yvette (France); Chartier, Frédéric, E-mail: frederic.chartier@cea.fr [CEA Saclay, DEN, DANS, DPC, 91191 Gif-sur-Yvette (France)

    2015-07-23

    Graphical abstract: This tutorial review is dedicated to the analysis of organic/hydro-organic matrices by ICP techniques. A state-of-the-art focusing on sample introduction, relevant operating parameters optimization and analytical strategies for elemental quantification is provided. - Highlights: • Practical considerations to perform analyses in organic/hydro-organic matrices. • Description, benefits and drawbacks of recent introduction devices. • Optimization to improve plasma tolerance towards organic/hydro-organic matrices. • Analytical strategies for elemental quantification in organic/hydro-organic matrices. - Abstract: Inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are increasingly used to carry out analyses in organic/hydro-organic matrices. The introduction of such matrices into ICP sources is particularly challenging and can be the cause of numerous drawbacks. This tutorial review, divided in two parts, explores the rich literature related to the introduction of organic/hydro-organic matrices in ICP sources. Part I provided theoretical considerations associated with the physico-chemical properties of such matrices, in an attempt to understand the induced phenomena. Part II of this tutorial review is dedicated to more practical considerations on instrumentation, instrumental and operating parameters, as well as analytical strategies for elemental quantification in such matrices. Two important issues are addressed in this part: the first concerns the instrumentation and optimization of instrumental and operating parameters, pointing out (i) the description, benefits and drawbacks of different kinds of nebulization and desolvation devices and the impact of more specific instrumental parameters such as the injector characteristics and the material used for the cone; and, (ii) the optimization of operating parameters, for both ICP-OES and ICP-MS. Even if it is at the margin of this tutorial review

  10. Introduction of organic/hydro-organic matrices in inductively coupled plasma optical emission spectrometry and mass spectrometry: A tutorial review. Part I. Theoretical considerations

    Energy Technology Data Exchange (ETDEWEB)

    Leclercq, Amélie, E-mail: amelie.leclercq@cea.fr [CEA Saclay, DEN, DANS, DPC, SEARS, Laboratoire de développement Analytique Nucléaire Isotopique et Elémentaire, 91191 Gif-sur-Yvette (France); Nonell, Anthony, E-mail: anthony.nonell@cea.fr [CEA Saclay, DEN, DANS, DPC, SEARS, Laboratoire de développement Analytique Nucléaire Isotopique et Elémentaire, 91191 Gif-sur-Yvette (France); Todolí Torró, José Luis, E-mail: jose.todoli@ua.es [Universidad de Alicante, Departamento de Quimica Analitica, Nutricion y Bromatología, Ap. de Correos, 99, 03080 Alicante (Spain); Bresson, Carole, E-mail: carole.bresson@cea.fr [CEA Saclay, DEN, DANS, DPC, SEARS, Laboratoire de développement Analytique Nucléaire Isotopique et Elémentaire, 91191 Gif-sur-Yvette (France); Vio, Laurent, E-mail: laurent.vio@cea.fr [CEA Saclay, DEN, DANS, DPC, SEARS, Laboratoire de développement Analytique Nucléaire Isotopique et Elémentaire, 91191 Gif-sur-Yvette (France); Vercouter, Thomas, E-mail: thomas.vercouter@cea.fr [CEA Saclay, DEN, DANS, DPC, SEARS, Laboratoire de développement Analytique Nucléaire Isotopique et Elémentaire, 91191 Gif-sur-Yvette (France); Chartier, Frédéric, E-mail: frederic.chartier@cea.fr [CEA Saclay, DEN, DANS, DPC, 91191 Gif-sur-Yvette (France)

    2015-07-23

    Highlights: • Tutorial review addressed to beginners or more experienced analysts. • Theoretical background of effects caused by organic matrices on ICP techniques. • Spatial distribution of carbon species and analytes in plasma. • Carbon spectroscopic and non-spectroscopic interferences in ICP. - Abstract: Due to their outstanding analytical performances, inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are widely used for multi-elemental measurements and also for isotopic characterization in the case of ICP-MS. While most studies are carried out in aqueous matrices, applications involving organic/hydro-organic matrices become increasingly widespread. This kind of matrices is introduced in ICP based instruments when classical “matrix removal” approaches such as acid digestion or extraction procedures cannot be implemented. Due to the physico-chemical properties of organic/hydro-organic matrices and their associated effects on instrumentation and analytical performances, their introduction into ICP sources is particularly challenging and has become a full topic. In this framework, numerous theoretical and phenomenological studies of these effects have been performed in the past, mainly by ICP-OES, while recent literature is more focused on applications and associated instrumental developments. This tutorial review, divided in two parts, explores the rich literature related to the introduction of organic/hydro-organic matrices in ICP-OES and ICP-MS. The present Part I, provides theoretical considerations in connection with the physico-chemical properties of organic/hydro-organic matrices, in order to better understand the induced phenomena. This focal point is divided in four chapters highlighting: (i) the impact of organic/hydro-organic matrices from aerosol generation to atomization/excitation/ionization processes; (ii) the production of carbon molecular constituents and their spatial distribution in the

  11. Introduction of organic/hydro-organic matrices in inductively coupled plasma optical emission spectrometry and mass spectrometry: a tutorial review. Part I. Theoretical considerations.

    Science.gov (United States)

    Leclercq, Amélie; Nonell, Anthony; Todolí Torró, José Luis; Bresson, Carole; Vio, Laurent; Vercouter, Thomas; Chartier, Frédéric

    2015-07-23

    Due to their outstanding analytical performances, inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are widely used for multi-elemental measurements and also for isotopic characterization in the case of ICP-MS. While most studies are carried out in aqueous matrices, applications involving organic/hydro-organic matrices become increasingly widespread. This kind of matrices is introduced in ICP based instruments when classical "matrix removal" approaches such as acid digestion or extraction procedures cannot be implemented. Due to the physico-chemical properties of organic/hydro-organic matrices and their associated effects on instrumentation and analytical performances, their introduction into ICP sources is particularly challenging and has become a full topic. In this framework, numerous theoretical and phenomenological studies of these effects have been performed in the past, mainly by ICP-OES, while recent literature is more focused on applications and associated instrumental developments. This tutorial review, divided in two parts, explores the rich literature related to the introduction of organic/hydro-organic matrices in ICP-OES and ICP-MS. The present Part I, provides theoretical considerations in connection with the physico-chemical properties of organic/hydro-organic matrices, in order to better understand the induced phenomena. This focal point is divided in four chapters highlighting: (i) the impact of organic/hydro-organic matrices from aerosol generation to atomization/excitation/ionization processes; (ii) the production of carbon molecular constituents and their spatial distribution in the plasma with respect to analytes repartition; (iii) the subsequent modifications of plasma fundamental properties; and (iv) the resulting spectroscopic and non spectroscopic interferences. This first part of this tutorial review is addressed either to beginners or to more experienced scientists who are interested in the

  12. Finite Element Analysis in the Estimation of Air-Gap Torque and Surface Temperature of Induction Machine

    Science.gov (United States)

    Mr., J. Ravi Kumar; Banakara, Basavaraja, Dr.

    2017-08-01

    This paper presents electromagnetic and thermal behavior of Induction Motor (IM) through the modeling and analysis by applying multiphysics coupled Finite Element Analysis (FEA). Therefore prediction of the magnetic flux, electromagnetic torque, stator and rotor losses and temperature distribution inside an operating electric motor are the most important issues during its design. Prediction and estimation of these parameters allows design engineers to decide capability of the machine for the proposed load, temperature rating and its application for which it is being designed ensuring normal motor operation at rated conditions. In this work, multiphysics coupled electromagnetic - thermal modeling and analysis of induction motor at rated and high frequency has carried out applying Arkkio’s torque method. COMSOL Multiphysics software is used for modeling and finite element analysis of IM. Transient electromagnetic torque, magnetic field distribution, speed-torque characteristics of IM were plotted and studied at different frequencies. This proposed work helps in the design and prediction of accurate performance of induction motor specific to various industrial drive applications. Results obtained are also validated with experimental analysis. The main purpose of this model is to use it as an integral part of the design aiming to system optimization of Variable Speed Drive (VSD) and its components using coupled simulations.

  13. Electromagnetic pulses bone healing booster

    Science.gov (United States)

    Sintea, S. R.; Pomazan, V. M.; Bica, D.; Grebenisan, D.; Bordea, N.

    2015-11-01

    Posttraumatic bone restoration triggered by the need to assist and stimulate compensatory bone growth in periodontal condition. Recent studies state that specific electromagnetic stimulation can boost the bone restoration, reaching up to 30% decrease in recovery time. Based on the existing data on the electromagnetic parameters, a digital electronic device is proposed for intra oral mounting and bone restoration stimulation in periodontal condition. The electrical signal is applied to an inductive mark that will create and impregnate magnetic field in diseased tissue. The device also monitors the status of the electromagnetic field. Controlled wave forms and pulse frequency signal at programmable intervals are obtained with optimized number of components and miniaturized using surface mounting devices (SMD) circuits and surface mounting technology (SMT), with enhanced protection against abnormal current growth, given the intra-oral environment. The system is powered by an autonomous power supply (battery), to limit the problems caused by powering medical equipment from the main power supply. Currently the device is used in clinical testing, in cycles of six up to twelve months. Basic principles for the electrical scheme and algorithms for pulse generation, pulse control, electromagnetic field control and automation of current monitoring are presented, together with the friendly user interface, suitable for medical data and patient monitoring.

  14. Properties of dynamical electromagnetic metamaterials

    Science.gov (United States)

    Padilla, Willie J.; Averitt, Richard D.

    2017-08-01

    Electromagnetic metamaterials consist of two or three dimensional arrays of tailored metallic and/or dielectric inclusions and provide unprecedented sub-wavelength control over light-matter interactions. Metamaterials are fashioned to yield a specific response to the electric and magnetic components of light and may be treated as effective media, described by effective optical constants {μ }{{eff}} and {{ɛ }}{{eff}}, and have realized a multitude of exotic properties difficult to achieve with natural materials. An inductive-capacitive unit cell geometry provides enhanced values of optical constants, as well as the ability to dynamically control the novel responses exhibited by electromagnetic metamaterials. The ability of metamaterials to achieve real-time dynamic properties has realized novel applications and has made them relevant for the next revolution in advanced materials and related devices.

  15. Hydrological Aspects of Electromagnetic Surveys

    Directory of Open Access Journals (Sweden)

    Baden G. Williams

    2014-01-01

    Full Text Available Interpreting Electromagnetic (EM surveys - Electromagnetic induction techniques have now largely replaced previous descriptive, and largely subjective, techniques used for soil salinity surveys. The question then is a matter of how to interpret the EM data. A very clear linkage exists between Apparent Electrical Conductivity (ECa and the total soluble salts in the upper soil profile. This, in turn, can be interpreted as reflecting the degree of vertical/ lateral leaching of soluble salts, or of salt accumulation in the profile. Topography, depth to groundwater and groundwater salinity also appear to affect ECa, although they are not suited to rapid survey techniques and do not necessarily have a direct relationship with either the total salt content of the upper soil profile or the ECa values. The interpretation of isoconductivity maps in terms of the degree of leaching of the soil profile from point to point provides an added hydrological management perspective to EM soil salinity surveys.

  16. Topological Foundations of Electromagnetism

    CERN Document Server

    Barrett, Terrence W

    2008-01-01

    Topological Foundations of Electromagnetism seeks a fundamental understanding of the dynamics of electromagnetism; and marshals the evidence that in certain precisely defined topological conditions, electromagnetic theory (Maxwell's theory) must be extended or generalized in order to provide an explanation and understanding of, until now, unusual electromagnetic phenomena. Key to this generalization is an understanding of the circumstances under which the so-called A potential fields have physical effects. Basic to the approach taken is that the topological composition of electromagnetic field

  17. Morgantown People Mover Electromagnetic Compatibility Program

    Science.gov (United States)

    1980-09-01

    Electromagnetic Compatibility (EMC) of a transit system is the absence of interference between all parts of the system, and between the system and the community which it serves. This report documents the EMC experience obtained during the design and ...

  18. Electromagnetic reciprocity in antenna theory

    CERN Document Server

    Stumpf, Martin

    2018-01-01

    The reciprocity theorem is among the most intriguing concepts in wave field theory and has become an integral part of almost all standard textbooks on electromagnetic (EM) theory. This book makes use of the theorem to quantitatively describe EM interactions concerning general multiport antenna systems. It covers a general reciprocity-based description of antenna systems, their EM scattering properties, and further related aspects. Beginning with an introduction to the subject, Electromagnetic Reciprocity in Antenna Theory provides readers first with the basic prerequisites before offering coverage of the equivalent multiport circuit antenna representations, EM coupling between multiport antenna systems and their EM interactions with scatterers, accompanied with the corresponding EM compensation theorems.

  19. Electromagnetic compatibility and interference metrology

    Science.gov (United States)

    Ma, M. T.; Kanda, M.

    1986-07-01

    The material included in the report is intended for a short course on electromagnetic compatibility/interference (EMC/EM) metrology. The entire course is presented in nine chapters with the introductory part given as Chapter 1. The particular measurement topics to be covered are: (1) open sites (Chapters 2 and 6), (2) transverse electromagnetic cells (Chapter 3), (3) techniques for measuring the electromagnetic shielding of materials (Chapter 4), (4) anechoic chambers (Chapter 5), and (5) reverberating chambers (Chapter 8). In addition, since small probe antennas play an important role in some of the EMC/EMI measurements discussed, a separate chapter on various probe systems developed at NBS is given in Chapter 7. Selected contemporary EMI topics such as the characterization and measurement of a complex EM environment, interferences in the form of out-of-band receptions to an antenna, and some conducted EMI problems are also briefly discussed (Chapter 9).

  20. Practicing induction:

    DEFF Research Database (Denmark)

    Sprogøe, Jonas; Rohde, Nicolas

    2009-01-01

    We claim that induction potentially triggers both individual and organizational learning and by drawing on practice-based theory we discuss how the interplay between individual and organization, what we call a generative dance, ignites both kinds of learning....

  1. Induction heating using induction coils in series-parallel circuits

    Energy Technology Data Exchange (ETDEWEB)

    Matsen, Marc Rollo; Geren, William Preston; Miller, Robert James; Negley, Mark Alan; Dykstra, William Chet

    2017-11-14

    A part is inductively heated by multiple, self-regulating induction coil circuits having susceptors, coupled together in parallel and in series with an AC power supply. Each of the circuits includes a tuning capacitor that tunes the circuit to resonate at the frequency of AC power supply.

  2. COHERENCE PROPERTIES OF ELECTROMAGNETIC RADIATION,

    Science.gov (United States)

    ELECTROMAGNETIC RADIATION , COHERENT SCATTERING), (*COHERENT SCATTERING, ELECTROMAGNETIC RADIATION ), LIGHT, INTERFERENCE, INTENSITY, STATISTICAL FUNCTIONS, QUANTUM THEORY, BOSONS, INTERFEROMETERS, CHINA

  3. Induction Brazing

    DEFF Research Database (Denmark)

    Henningsen, Poul

    Induction brazing is a fast and appropriate method for industrial joining of complex geometries and metal combinations. In all types of brazing processes it is important to heat the joint interface of the two materials to the same, high temperature. If one of the specimens is warmer than the other...... materials has large influence on the heating time and temperature distribution in induction heating. In order to ensure high and uniform temperature distribution near the interface of a joint between dissimilar materials the precise coil geometry and position is of great importance. The present report...... presents a combined numerical and experimental method for determination of appropriate/optimiged coil geometry and position in induction brazing tube-to-plate joints of different ratios between tube and plate thickness and different combinations of the materials stainless steel, brass and copper...

  4. Electromagnetic Education in India

    Science.gov (United States)

    Bajpai, Shrish; Asif, Siddiqui Sajida; Akhtar, Syed Adnan

    2016-01-01

    Out of the four fundamental interactions in nature, electromagnetics is one of them along with gravitation, strong interaction and weak interaction. The field of electromagnetics has made much of the modern age possible. Electromagnets are common in day-to-day appliances and are becoming more conventional as the need for technology increases.…

  5. Velocity damper for electromagnetically levitated materials

    Science.gov (United States)

    Fox, Richard J.

    1994-01-01

    A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation.

  6. Induction, complexity, and economic methodology

    OpenAIRE

    Smith, Peter

    2009-01-01

    This paper focuses on induction, because the supposed weaknesses of that process are the main reason for favouring falsificationism, which plays an important part in scientific methodology generally; the paper is part of a wider study of economic methodology. The standard objections to, and paradoxes of, induction are reviewed, and this leads to the conclusion that the supposed ‘problem’ or ‘riddle’ of induction is a false one. It is an artefact of two assumptions: that the classic two-valued...

  7. Leaf spring, and electromagnetic actuator provided with a leaf spring

    NARCIS (Netherlands)

    Berkhoff, Arthur P.; Lemmen, Remco Louis Christiaan

    2002-01-01

    The invention relates to a leaf spring for an electromagnetic actuator and to such an electromagnetic actuator. The leaf spring is formed as a whole from a disc of plate-shaped, resilient material. The leaf spring comprises a central fastening part, an outer fastening part extending therearound and

  8. HIGH POWER APPLICATIONS OF ELECTROMAGNETIC DEVICES

    Directory of Open Access Journals (Sweden)

    VASILE DOBREF

    2016-06-01

    Full Text Available For the next generation, conventional weapon will touch the best performance limits and will became more and more what in what more an important part plans of improvement systems of weapon to the future. Physical laws that govern electromagnetic propulsion of guns, enabling them higher speeds than those of conventional arms projectiles. This is substantially benefit electromagnetic weapons - using electricity as energy for an lectromagnetic weapons.

  9. Health effects of electromagnetic fields.

    OpenAIRE

    Peter Gajšek

    1990-01-01

    Abstract: Devices that emit electromagnetic fields (EMF) have become a part of our daily life and can be found in telecommunications, industry, traffic, science, medicine and in every household. Due to the fact that general public is massively exposed to the EMF, even very small health effects could become a serious public health problem. Many studies show that the EMF above a certain threshold can have a negative health impact. The studies, which could explain the question of health risks as...

  10. An electrospray/inductively coupled plasma dual-source time-of-flight mass spectrometer for rapid metallomic and speciation analysis. Part 1. Molecular channel characterization.

    Science.gov (United States)

    Rogers, Duane A; Ray, Steven J; Hieftje, Gary M

    2010-04-01

    A new time-of-flight mass spectrometer has been developed that uses an electrospray source and an inductively coupled plasma to extract molecular, atomic, and isotopic information simultaneously from a single sample. This paper will focus on characterization of the ESI channel. Sensitivities are reported for hexadecyltrimethylammonium, tetrahexylammonium, tetraoctylammonium, myoglobin, insulin, cyanocobalamin, leucine enkephalin, and alcohol dehydrogenase. Skimmer-nozzle collisionally induced dissociation is explored for adduct removal and analyte fragmentation on the ESI channel for tetraoctylammonium ion and leucine enkephalin. Long-term and short-term spray stability is also examined.

  11. Increased Expression of a myo-Inositol Methyl Transferase in Mesembryanthemum crystallinum Is Part of a Stress Response Distinct from Crassulacean Acid Metabolism Induction 1

    Science.gov (United States)

    Vernon, Daniel M.; Bohnert, Hans J.

    1992-01-01

    The facultative halophyte Mesembryanthemum crystallinum responds to osmotic stress by switching from C3 photosynthesis to Crassulacean acid metabolism (CAM). This shift to CAM involves the stress-initiated up-regulation of mRNAs encoding CAM enzymes. The capability of the plants to induce a key CAM enzyme, phosphoenolpyruvate carboxylase, is influenced by plant age, and it has been suggested that adaptation to salinity in M. crystallinum may be modulated by a developmental program that controls molecular responses to stress. We have compared the effects of plant age on the expression of two salinity-induced genes: Gpdl, which encodes the photosynthesis-related enzyme glyceraldehyde 3-phosphate dehydrogenase, and Imtl, which encodes a methyl transferase involved in the biosynthesis of a putative osmoprotectant, pinitol. Imtl mRNA accumulation and the accompanying increase in pinitol in stressed Mesembryanthemum exhibit a pattern of induction distinct from that observed for CAM-related genes. We conclude that the molecular mechanisms that trigger Imtl and pinitol accumulation in response to salt stress in M. crystallinum differ in some respects from those that lead to CAM induction. There may be multiple signals or pathways that regulate inducible components of salinity tolerance in this facultative halophyte. ImagesFigure 1Figure 2 PMID:16669095

  12. Induction practice -

    DEFF Research Database (Denmark)

    Rohde, Nicolas; Sprogøe, Jonas

    2007-01-01

    of learning. We focus on and describe the interplay that takes place in particular induction events and analyze the "dance" through the lens of learning. The paper concludes with a brief discussion about the implications for practitioners and the challenges and future research prospects we have encountered....... We draw on an empirical enquiry in two organizational settings, a Danish management consulting company and a German retail bank....

  13. COMPARATIVE ANALYSIS OF ACTIVE POWER LOSSES OF INDUCTION MOTORS WITH CYLINDRICAL AND AXIAL AIR GAPS

    Directory of Open Access Journals (Sweden)

    А.А. Stavinskii

    2015-11-01

    Full Text Available Purpose. To find the analytical expressions of determining the optimum geometric dimensions by criteria of the losses minimum of axial field squirrel-cage induction motors and to compare traditional and axial field motors. Methodology. We have applied the method of the relative indications of the technical level with relative controlled variables. We have used the approximation of the experimental dependence of the distribution of the induction in the air gap and the integral averaging of the magnetic flux. Results. We have developed the mathematical model for determining the optimum geometric dimensions by criteria of the losses minimum of the active part of axial field squirrel-cage induction motors taking into account the radial distribution of the induction in the air gap and teeth. We have considered the comparative analysis of the indications of active power losses of traditional and axial designs of electromagnetic equivalent motors. Originality. For the first time we have created the mathematical model of the active power losses of the active part of axial field squirrel-cage induction motors with the uneven distribution of the magnetic flux in the core and investigated the effect of the geometric relationships on the energy efficiency of axial field motors. Practical value. Based on the superior parametric compatibility and the high energy efficiency of axial motors the expediency of replacing traditional induction motors to axial field induction motors has been proved in the special drives, which operates in continuous duty. Also obtained by simulation optimal geometric relationships of the magnetic circuit can be used in the manufacture and design of axial motors by criteria of the losses minimum.

  14. Basic Electromagnetism and Materials

    CERN Document Server

    Moliton, André

    2007-01-01

    Basic Electromagnetism and Materials is the product of many years of teaching basic and applied electromagnetism. This textbook can be used to teach electromagnetism to a wide range of undergraduate science majors in physics, electrical engineering or materials science. However, by making lesser demands on mathematical knowledge than competing texts, and by emphasizing electromagnetic properties of materials and their applications, this textbook is uniquely suited to students of materials science. Many competing texts focus on the study of propagation waves either in the microwave or optical domain, whereas Basic Electromagnetism and Materials covers the entire electromagnetic domain and the physical response of materials to these waves. Professor André Moliton is Director of the Unité de Microélectronique, Optoélectronique et Polymères (Université de Limoges, France), which brings together three groups studying the optoelectronics of molecular and polymer layers, micro-optoelectronic systems for teleco...

  15. Electromagnetic ultrasonic guided waves

    CERN Document Server

    Huang, Songling; Li, Weibin; Wang, Qing

    2016-01-01

    This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

  16. Review of the Maxwell-Heaviside-Hertz form classical electromagnetic theory.

    OpenAIRE

    日高, 建彦

    2009-01-01

    We review the Maxwell-Heaviside-Hertz classical electromagnetic theory constructed with magnetic filed B and electricfield E. The theory is incomplete because it can not give the correct electromagnetic induction outside of the ideal longsolenoid coil. Another classical electromagnetic theory, constructed with a suitable Lagrangian including the potentials Aand φ and the action principle, would produce satisfactory results. The potentials A and φ are the main roles in, not onlyquantum mechani...

  17. Kinetic analysis of spin current contribution to spectrum of electromagnetic waves in spin-1/2 plasma, Part II: Dispersion dependencies

    CERN Document Server

    Andreev, Pavel A

    2016-01-01

    The dielectric permeability tensor for spin polarized plasmas derived in terms of the spin-1/2 quantum kinetic model in six-dimensional phase space in Part I of this work is applied for study of spectra of high-frequency transverse and transverse-longitudinal waves propagating perpendicular to the external magnetic field. Cyclotron waves are studied at consideration of waves with electric field directed parallel to the external magnetic field. It is found that the separate spin evolution modifies the spectrum of cyclotron waves. These modifications increase with the increase of the spin polarization and the number of the cyclotron resonance. Spin dynamics with no account of the anomalous magnetic moment gives a considerable modification of spectra either. The account of anomalous magnetic moment leads to a fine structure of each cyclotron resonance. So, each cyclotron resonance splits on three waves. Details of this spectrum and its changes with the change of spin polarization are studied for the first and se...

  18. Static electromagnetic frequency changers

    CERN Document Server

    Rozhanskii, L L

    1963-01-01

    Static Electromagnetic Frequency Changers is about the theory, design, construction, and applications of static electromagnetic frequency changers, devices that used for multiplication or division of alternating current frequency. It is originally published in the Russian language. This book is organized into five chapters. The first three chapters introduce the readers to the principles of operation, the construction, and the potential applications of static electromagnetic frequency changers and to the principles of their design. The two concluding chapters use some hitherto unpublished work

  19. Review on Computational Electromagnetics

    Directory of Open Access Journals (Sweden)

    P. Sumithra

    2017-03-01

    Full Text Available Computational electromagnetics (CEM is applied to model the interaction of electromagnetic fields with the objects like antenna, waveguides, aircraft and their environment using Maxwell equations.  In this paper the strength and weakness of various computational electromagnetic techniques are discussed. Performance of various techniques in terms accuracy, memory and computational time for application specific tasks such as modeling RCS (Radar cross section, space applications, thin wires, antenna arrays are presented in this paper.

  20. Electromagnetic Radiation Analysis

    Science.gov (United States)

    1978-04-10

    A methodology is given for determining whether electromagnetic radiation of sufficient strength to cause performance degradation to the test item...exists at the test item location. The results of an electromagnetic radiation effects test are used to identify the radio frequencies and electromagnetic ... radiation levels to which the test item is susceptible. Further, using a test bed, comparisons are made with the representative signal levels to

  1. NASA EEE Parts 2014 Year in Review

    Science.gov (United States)

    Lee, Sara-Anne

    2015-01-01

    The NASA Electronic Parts and Packaging Program continue to support Electrical, Electronic and Electromagnetic Parts for the agency with an eventful year of workshops, innovations, testing and challenges.

  2. Electromagnetic Interface Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Electromagnetic Interface Testing facilitysupports such testing asEmissions, Field Strength, Mode Stirring, EMP Pulser, 4 Probe Monitoring/Leveling System, and...

  3. Study on the induction heating of the workpiece before gear rolling process

    Science.gov (United States)

    Ji, Hongchao; Wang, Baoyu; Fu, Xiaobin

    2017-10-01

    Gear forming by cross rolling with local induction heating process is an alternative method to manufacturing large diameter gear parts, and the distribution of the temperature has a great influence on the subsequently gear forming process. To get a satisfied temperature distribution of the heated workpiece, the model of induction heating process by coupling the electromagnetic and thermal field combing the rotational motion is established and the heating rate and temperature distribution along the axial and circumferential has been investigated. Moreover, corresponding experiment was carried out and the heating parameter and temperature distribution were measured by multi meter and infrared thermographic imaging. According to the comparison of the experimental and simulation results, the established model was verified and the simulation results are reliable.

  4. Effect Of Turbulence Modelling In Numerical Analysis Of Melting Process In An Induction Furnace

    Directory of Open Access Journals (Sweden)

    Buliński P.

    2015-09-01

    Full Text Available In this paper, the velocity field and turbulence effects that occur inside a crucible of a typical induction furnace were investigated. In the first part of this work, a free surface shape of the liquid metal was measured in a ceramic crucible. Then a numerical model of aluminium melting process was developed. It took into account coupling of electromagnetic and thermofluid fields that was performed using commercial codes. In the next step, the sensitivity analysis of turbulence modelling in the liquid domain was performed. The obtained numerical results were compared with the measurement data. The performed analysis can be treated as a preliminary approach for more complex mathematical modelling for the melting process optimisation in crucible induction furnaces of different types.

  5. Electromagnetic sounding of the Earth's interior

    CERN Document Server

    Spichak, Viacheslav V

    2015-01-01

    Electromagnetic Sounding of the Earth's Interior 2nd edition provides a comprehensive up-to-date collection of contributions, covering methodological, computational and practical aspects of Electromagnetic sounding of the Earth by different techniques at global, regional and local scales. Moreover, it contains new developments such as the concept of self-consistent tasks of geophysics and , 3-D interpretation of the TEM sounding which, so far, have not all been covered by one book. Electromagnetic Sounding of the Earth's Interior 2nd edition consists of three parts: I- EM sounding methods, II- Forward modelling and inversion techniques, and III - Data processing, analysis, modelling and interpretation. The new edition includes brand new chapters on Pulse and frequency electromagnetic sounding for hydrocarbon offshore exploration. Additionally all other chapters have been extensively updated to include new developments. Presents recently developed methodological findings of the earth's study, including seism...

  6. Integration of basic electromagnetism and engineering technology

    DEFF Research Database (Denmark)

    Bentz, Sigurd

    1995-01-01

    and retain much of the course material, which in turn makes their subsequent studies more difficult. We describe a freshman course in electromagnetism which alleviates these problems. Our hypothesis is that the course material is difficult to grasp because of its abstract nature. Consequently the purely...... and their application in technology students get a more comprehensive understanding of electromagnetism, and they are able to apply the physical principles to problems they encounter later in their careers......The theory of electromagnetism is taught as a part of most contemporary electrical engineering curricula. Usually a basic course is intended to cover all the fundamental electromagnetic theory which is needed in later engineering courses. However it is often found that students fail to understand...

  7. POSSIBILITIES FOR OPTIMIZATION OF CIRCUIT ACCELERATING OPERATION OF ELECTROMAGNETS

    Directory of Open Access Journals (Sweden)

    S. S. Stoyanova

    2005-01-01

    Full Text Available The paper reveals an accelerating circuit for electromagnet operation with the help of an additional resistor R that is shunted with a capacitor C. Resistor R is connected in series with the electromagnet winding. The possibility of the circuit optimization has been substantiated with the purpose to limit the final speed with which a movable part of the electromagnet reaches a limiter. Such circuit may find its application in relay protection.

  8. High frequency electromagnetic dosimetry

    CERN Document Server

    Sánchez-Hernández, David A

    2009-01-01

    Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.

  9. Electromagnetically Operated Counter

    Science.gov (United States)

    Goldberg, H D; Goldberg, M I

    1951-12-18

    An electromagnetically operated counter wherein signals to be counted are applied to cause stepwise rotation of a rotatable element which is connected to a suitable register. The mechanism involved consists of a rotatable armature having three spaced cores of magnetic material and a pair of diametrically opposed electromagnets with a suitable pulsing circuit to actuate the magnets.

  10. Tunability enhanced electromagnetic wiggler

    Science.gov (United States)

    Schlueter, R.D.; Deis, G.A.

    1992-03-24

    The invention discloses a wiggler used in synchrotron radiation sources and free electron lasers, where each pole is surrounded by at least two electromagnetic coils. The electromagnetic coils are energized with different amounts of current to provide a wide tunable range of the on-axis magnetic flux density, while preventing magnetic saturation of the poles. 14 figs.

  11. Classical electromagnetic radiation

    CERN Document Server

    Heald, Mark A

    2012-01-01

    Newly corrected, this highly acclaimed text is suitable for advanced physics courses. The author presents a very accessible macroscopic view of classical electromagnetics that emphasizes integrating electromagnetic theory with physical optics. The survey follows the historical development of physics, culminating in the use of four-vector relativity to fully integrate electricity with magnetism.

  12. An Electromagnetic Beam Converter

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to an electromagnetic beam converter and a method for conversion of an input beam of electromagnetic radiation having a bell shaped intensity profile a(x,y) into an output beam having a prescribed target intensity profile l(x',y') based on a further development...

  13. Physics of classical electromagnetism

    CERN Document Server

    Fujimoto, Minoru

    2007-01-01

    The classical electromagnetism described by the Maxwell equations constitutes a fundamental law in contemporary physics. Even with the advent of sophisticated new materials, the principles of classical electromagnetism are still active in various applied areas in today’s advanced communication techniques. Physics of Classical Electromagnetism, by Minoru Fujimoto, is written with concise introductory arguments emphasizing the original field concept, with an aim at understanding objectives in modern information technology. Following basic discussions of electromagnetism with a modernized approach, this book will provide readers with an overview of current problems in high-frequency physics. To further the reader’s understanding of the concepts and applications discussed, each illustration within the book shows the location of all active charges, and the author has provided many worked-out examples throughout the book. Physics of Classical Electromagnetism is intended for students in physics and engineering ...

  14. Panobinostat as part of induction and maintenance for elderly patients with newly diagnosed acute myeloid leukemia: phase Ib/II panobidara study.

    Science.gov (United States)

    Ocio, Enrique M; Herrera, Pilar; Olave, María-Teresa; Castro, Nerea; Pérez-Simón, José A; Brunet, Salut; Oriol, Albert; Mateo, Marta; Sanz, Miguel-Ángel; López, Javier; Montesinos, Pau; Chillón, María-Carmen; Prieto-Conde, María-Isabel; Díez-Campelo, María; González, Marcos; Vidriales, María-Belén; Mateos, María-Victoria; San Miguel, Jesús F

    2015-10-01

    This phase Ib/II trial combined the pan-deacetylase inhibitor panobinostat with chemotherapy followed by panobinostat maintenance in elderly patients with newly diagnosed acute myeloid leukemia. Patients with prior history of myelodysplastic syndrome were excluded and 38 evaluable patients were included in the study (median age: 71 years; range: 65-83). Study patients received an induction with idarubicin (8 mg/m(2) iv days 1-3) plus cytarabine (100 mg/m(2) iv days 1-7) plus panobinostat po at escalating doses (days 8, 10, 12, 15, 17 and 19) that could be repeated in non-responding patients. Patients achieving complete remission received a consolidation cycle with the same schema, followed by panobinostat maintenance (40 mg po 3 days/week) every other week until progression. Thirty-one patients were treated at the maximum tolerated dose of panobinostat in the combination (10 mg) with good tolerability. Complete remission rate was 64% with a time to relapse of 17.0 months (12.8-21.1). Median overall survival for the whole series was 17 months (5.5-28.4). Moreover, in 4 of 5 patients with persistent minimal residual disease before maintenance, panobinostat monotherapy reduced its levels, with complete negativization in two of them. Maintenance phase was well tolerated. The most frequent adverse events were thrombocytopenia (25% grades 3/4), and gastrointestinal toxicity, asthenia and anorexia (mainly grades 1/2). Five patients required dose reduction during this phase, but only one discontinued therapy due to toxicity. These results suggest that panobinostat is one of the first novel agents with activity in elderly acute myeloid leukemia patients, and suggest further investigation is warranted, particularly in the context of maintenance therapy. This trial is registered at clinicaltrials.gov identifier: 00840346. Copyright© Ferrata Storti Foundation.

  15. Micro Pulsed Inductive Thruster with Solid Fuel Option (uPIT_SF) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Micro Pulsed Inductive Thruster with Solid Fuel Option (5PIT_SF) is a high-precision impulse bit electromagnetic plasma micro-thruster. The 5PIT prototype is a...

  16. Broadband electromagnetic analysis of compacted kaolin

    Science.gov (United States)

    Bore, Thierry; Wagner, Norman; Cai, Caifang; Scheuermann, Alexander

    2017-01-01

    The mechanical compaction of soil influences not only the mechanical strength and compressibility but also the hydraulic behavior in terms of hydraulic conductivity and soil suction. At the same time, electric and dielectric parameters are increasingly used to characterize soil and to relate them with mechanic and hydraulic parameters. In the presented study electromagnetic soil properties and suction were measured under defined conditions of standardized compaction tests. The impact of external mechanical stress conditions of nearly pure kaolinite was analyzed on soil suction and broadband electromagnetic soil properties. An experimental procedure was developed and validated to simultaneously determine mechanical, hydraulic and broadband (1 MHz-3 GHz) electromagnetic properties of the porous material. The frequency dependent electromagnetic properties were modeled with a classical mixture equation (advanced Lichtenecker and Rother model, ALRM) and a hydraulic-mechanical-electromagnetic coupling approach was introduced considering water saturation, soil structure (bulk density, porosity), soil suction (pore size distribution, water sorption) as well as electrical conductivity of the aqueous pore solution. Moreover, the relaxation behavior was analyzed with a generalized fractional relaxation model concerning a high-frequency water process and two interface processes extended with an apparent direct current conductivity contribution. The different modeling approaches provide a satisfactory agreement with experimental data for the real part. These results show the potential of broadband electromagnetic approaches for quantitative estimation of the hydraulic state of the soil during densification.

  17. Instability in electromagnetically driven flows Part I

    CERN Document Server

    Gissinger, Christophe; Fauve, Stephan

    2016-01-01

    The MHD flow driven by a travelling magnetic field (TMF) in an annular channel is investigated numerically. For sufficiently large magnetic Reynolds number Rm, or if a large enough pressure gradient is externally applied, the system undergoes an instability in which the flow rate in the channel dramatically drops from synchronism with the wave to much smaller velocities. This transition takes the form of a saddle-node bifurcation for the time-averaged quantities. In this first paper, we characterize the bifurcation, and study the stability of the flow as a function of several parameters. We show that the bifurcation of the flow involves a bistability between Poiseuille-like and Hartman-like regimes, and relies on magnetic flux expulsion. Based on this observation, new predictions are made for the occurrence of this stalling instability.

  18. Lexicographic Path Induction

    DEFF Research Database (Denmark)

    Schürmann, Carsten; Sarnat, Jeffrey

    2009-01-01

    an induction principle that combines the comfort of structural induction with the expressive strength of transfinite induction. Using lexicographic path induction, we give a consistency proof of Martin-Löf’s intuitionistic theory of inductive definitions. The consistency of Heyting arithmetic follows directly...

  19. Nonlinear surface electromagnetic phenomena

    CERN Document Server

    Ponath, H-E

    1991-01-01

    In recent years the physics of electromagnetic surface phenomena has developed rapidly, evolving into technologies for communications and industry, such as fiber and integrated optics. The variety of phenomena based on electromagnetism at surfaces is rich and this book was written with the aim of summarizing the available knowledge in selected areas of the field. The book contains reviews written by solid state and optical physicists on the nonlinear interaction of electromagnetic waves at and with surfaces and films. Both the physical phenomena and some potential applications are

  20. Computer techniques for electromagnetics

    CERN Document Server

    Mittra, R

    1973-01-01

    Computer Techniques for Electromagnetics discusses the ways in which computer techniques solve practical problems in electromagnetics. It discusses the impact of the emergence of high-speed computers in the study of electromagnetics. This text provides a brief background on the approaches used by mathematical analysts in solving integral equations. It also demonstrates how to use computer techniques in computing current distribution, radar scattering, and waveguide discontinuities, and inverse scattering. This book will be useful for students looking for a comprehensive text on computer techni

  1. Two fluxes multistage induction coilgun

    Science.gov (United States)

    Gherman, L.; Pearsica, M.; Circiu, I.; Rotaru, C.

    2017-05-01

    This paper presents a brand new induction electromagnetic launcher, which uses two magnetic fluxes in order to accelerate a projectile. One magnetic flux induce a current in the armature and the second magnetic flux is creating a radial magnetic field. This aproach offer multiple advantages over single flux designs. First we are able to control the induced current in armature because we use the coil just to induce current inside the ring with a great efficiency. Second advantage is the angle of 900 between magnetic field density B and the ring. We used the induction to avoid contact between armature and accelerator. In order to create the magnetic field radial we used four coils perpendicular on armature. This approach alove us to control the phase difference between induced current in armature and current in magnetic field coils for a maximum force. The phase difference is obtained by changing the frequency of magnetic field coils power source. We used simulation software to analyze, and simulate a multistage induction coilgun design with two fluxes. The simulation results demonstrated the theoretical results.

  2. BGO* electromagnetic calorimeter

    CERN Multimedia

    CERN

    1988-01-01

    * Short for Bismuth-Germanium-Oxyde, a scintillator of high atomic number Z used in electromagnetic crystal calorimeters. BGO is characterized by fast rise time (a few nanoseconds) and short radiation length (1.11 cm).

  3. Broadband Electromagnetic Technology

    Science.gov (United States)

    2011-06-23

    The objectives of this project are to continue the enhancements to the combined Broadband Electromagnetic and Full Encirclement Unit (BEM-FEU) technologies and to evaluate the systems capability in the laboratory and the field. The BEM instrument ...

  4. Computational electromagnetic-aerodynamics

    CERN Document Server

    Shang, Joseph J S

    2016-01-01

    Presents numerical algorithms, procedures, and techniques required to solve engineering problems relating to the interactions between electromagnetic fields, fluid flow, and interdisciplinary technology for aerodynamics, electromagnetics, chemical-physics kinetics, and plasmadynamics This book addresses modeling and simulation science and technology for studying ionized gas phenomena in engineering applications. Computational Electromagnetic-Aerodynamics is organized into ten chapters. Chapter one to three introduce the fundamental concepts of plasmadynamics, chemical-physics of ionization, classical magnetohydrodynamics, and their extensions to plasma-based flow control actuators, high-speed flows of interplanetary re-entry, and ion thrusters in space exploration. Chapter four to six explain numerical algorithms and procedures for solving Maxwell’s equation in the time domain for computational electromagnetics, plasma wave propagation, and the time-dependent c mpressible Navier-Stokes equation for aerodyn...

  5. The classical electromagnetic field

    CERN Document Server

    Eyges, Leonard

    2010-01-01

    This excellent text covers a year's course in advanced theoretical electromagnetism, first introducing theory, then its application. Topics include vectors D and H inside matter, conservation laws for energy, momentum, invariance, form invariance, covariance in special relativity, and more.

  6. Purely electromagnetic spacetimes

    OpenAIRE

    Ivanov, B. V.

    2007-01-01

    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.

  7. Electromagnetic physical modeling. 11; Denji yudoho no model jikken. 11

    Energy Technology Data Exchange (ETDEWEB)

    Noguchi, K.; Endo, M.; Yoshimori, M.; Ogura, W. [Waseda University, Tokyo (Japan). School of Science and Engineering; Saito, A. [Mitsui Mineral Development Engineering Co. Ltd., Tokyo (Japan)

    1997-05-27

    A model experiment on the well electromagnetic induction method was studied. Experimental apparatus consisted chiefly of A/D boards of 16 bit and 100 kHz. In the transmitting part, the transistor inverter and relay switch controlled by computer with car battery as current source generate rectangular wave current and make it run to the transmitter loop. In the receiving part, after electromotive force induced to the receiver coil was amplified by amplifier, it is A/D converted and recorded by computer. As a result of the experiment, the depth, plane position and shape of the structure could be caught by studying data on the well and earth surface together. Further, it was confirmed that in case the disk tilted, the response regularly changes according to the tilt. Moreover, it was found that even in case the structure is just under the inside of the transmitter loop, the thickness and tilt of the structure are influenced by the positional relation with the receiver loop. 2 refs., 18 figs.

  8. Electromagnetic reverberation chambers

    CERN Document Server

    Besnier, Philippe

    2013-01-01

    Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

  9. Electromagnetic Education in India

    Directory of Open Access Journals (Sweden)

    Bajpai Shrish

    2016-06-01

    Full Text Available Out of the four fundamental interactions in nature, electromagnetics is one of them along with gravitation, strong interaction and weak interaction. The field of electromagnetics has made much of the modern age possible. Electromagnets are common in day-to-day appliances and are becoming more conventional as the need for technology increases. Electromagnetism has played a vital role in the progress of human kind ever since it has been understood. Electromagnets are found everywhere. One can find them in speakers, doorbells, home security systems, anti-shoplifting systems, hard drives, mobiles, microphones, Maglev trains, motors and many other everyday appliances and products. Before diving into the education system, it is necessary to reiterate its importance in various technologies that have evolved over time. Almost every domain of social life has electromagnetic playing its role. Be it the mobile vibrators you depend upon, a water pump, windshield wipers during rain and the power windows of your car or even the RFID tags that may ease your job during shopping. A flavor of electromagnetics is essential during primary level of schooling for the student to understand its future prospects and open his/her mind to a broad ocean of ideas. Due to such advancements this field can offer, study on such a field is highly beneficial for a developing country like India. The paper presents the scenario of electromagnetic education in India, its importance and numerous schemes taken by the government of India to uplift and acquaint the people about the importance of EM and its applications.

  10. Electromagnetic rotational actuation.

    Energy Technology Data Exchange (ETDEWEB)

    Hogan, Alexander Lee

    2010-08-01

    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.

  11. Grid computing for electromagnetics

    CERN Document Server

    Tarricone, Luciano

    2004-01-01

    Today, more and more practitioners, researchers, and students are utilizing the power and efficiency of grid computing for their increasingly complex electromagnetics applications. This cutting-edge book offers you the practical and comprehensive guidance you need to use this new approach to supercomputing for your challenging projects. Supported with over 110 illustrations, the book clearly describes a high-performance, low-cost method to solving huge numerical electromagnetics problems.

  12. Mapping saltwater intrusion in the Biscayne Aquifer, Miami-Dade County, Florida using transient electromagnetic sounding

    Science.gov (United States)

    Fitterman, David V.

    2014-01-01

    Saltwater intrusion in southern Florida poses a potential threat to the public drinking-water supply that is typically monitored using water samples and electromagnetic induction logs collected from a network of wells. Transient electromagnetic (TEM) soundings are a complementary addition to the monitoring program because of their ease of use, low cost, and ability to fill in data gaps between wells. TEM soundings have been used to map saltwater intrusion in the Biscayne aquifer over a large part of south Florida including eastern Miami-Dade County and the Everglades. These two areas are very different with one being urban and the other undeveloped. Each poses different conditions that affect data collection and data quality. In the developed areas, finding sites large enough to make soundings is difficult. The presence of underground pipes further restricts useable locations. Electromagnetic noise, which reduces data quality, is also an issue. In the Everglades, access to field sites is difficult and working in water-covered terrain is challenging. Nonetheless, TEM soundings are an effective tool for mapping saltwater intrusion. Direct estimates of water quality can be obtained from the inverted TEM data using a formation factor determined for the Biscayne aquifer. This formation factor is remarkably constant over Miami-Dade County owing to the uniformity of the aquifer and the absence of clay. Thirty-six TEM soundings were collected in the Model Land area of southeast Miami-Dade County to aid in calibration of a helicopter electromagnetic (HEM) survey. The soundings and HEM survey revealed an area of saltwater intrusion aligned with canals and drainage ditches along U.S. Highway 1 and the Card Sound Road. These canals and ditches likely reduced freshwater levels through unregulated drainage and provided pathways for seawater to flow at least 12.4 km inland.

  13. Entropy generation analysis of magnetohydrodynamic induction devices

    Energy Technology Data Exchange (ETDEWEB)

    Salas, Hugo [UAEMor., Facultad de Ciencias, Cuernavaca (Mexico); Cuevas, Sergio; Haro, Mariano Lopez de [UNAM, Centro de Investigacion en Energia, Temixco (Mexico)

    1999-10-21

    Magnetohydrodynamic (MHD) induction devices such as electromagnetic pumps or electric generators are analysed within the approach of entropy generation. The flow of an electrically-conducting incompressible fluid in an MHD induction machine is described through the well known Hartmann model. Irreversibilities in the system due to ohmic dissipation, flow friction and heat flow are included in the entropy-generation rate. This quantity is used to define an overall efficiency for the induction machine that considers the total loss caused by process irreversibility. For an MHD generator working at maximum power output with walls at constant temperature, an optimum magnetic field strength (i.e., Hartmann number) is found based on the maximum overall efficiency. (Author)

  14. Sulfur mustard analog, 2-chloroethyl ethyl sulfide-induced skin injury involves DNA damage and induction of inflammatory mediators, in part via oxidative stress, in SKH-1 hairless mouse skin.

    Science.gov (United States)

    Jain, Anil K; Tewari-Singh, Neera; Gu, Mallikarjuna; Inturi, Swetha; White, Carl W; Agarwal, Rajesh

    2011-09-10

    Bifunctional alkyalating agent, sulfur mustard (SM)-induced cutaneous injury is characterized by inflammation and delayed blistering. Our recent studies demonstrated that 2-chloroethyl ethyl sulfide (CEES), a monofunctional analog of SM that can be used in laboratory settings, induces oxidative stress. This could be the major cause of the activation of Akt/MAP kinase and AP1/NF-κB pathways that are linked to the inflammation and microvesication, and histopathological alterations in SKH-1 hairless mouse skin. To further establish a link between CEES-induced DNA damage and signaling pathways and inflammatory responses, skin samples from mice exposed to 2 mg or 4 mg CEES for 9-48 h were subjected to molecular analysis. Our results show a strong CEES-induced phosphorylation of H2A.X and an increase in cyclooxygenase-2 (COX-2), inducible NOS (iNOS), and matrix metalloproteinase-9 (MMP-9) levels, indicating the involvement of DNA damage and inflammation in CEES-induced skin injury in male and female mice. Since, our recent studies showed reduction in CEES-induced inflammatory responses by glutathione (GSH), we further assessed the role of oxidative stress in CEES-related DNA damage and the induction of inflammatory molecules. Oral GSH (300 mg/kg) administration 1h before CEES exposure attenuated the increase in both CEES-induced H2A.X phosphorylation (59%) as well as expression of COX-2 (68%), iNOS (53%) and MMP-9 (54%). Collectively, our results indicate that CEES-induced skin injury involves DNA damage and an induction of inflammatory mediators, at least in part via oxidative stress. This study could help in identifying countermeasures that alone or in combination, can target the unveiled pathways for reducing skin injury in humans by SM. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  15. Use of Blended Approach in the Learning of Electromagnetic Induction

    OpenAIRE

    Chew, Charles; Wee, Loo Kang

    2015-01-01

    This paper traces the importance of pedagogical content knowledge in the digital age to prepare today students for the 21st century. It highlights the need for ICT-based pedagogical models that are grounded in both the learning theories of constructivism and connectivism. One such suitable ICT-based pedagogical model is the TSOI Hybrid Learning Model. By means of a physics blended learning exemplar based on the TSOI Hybrid Learning Model, this paper argues for the use of blended learning appr...

  16. Electromagnetic Induction Spectroscopy for the Detection of Subsurface Targets

    Science.gov (United States)

    2012-12-01

    vol. 38, no. 5, pp. 814–824, 1990. [26] T. K. Sarkar and O. Pereira , “Using the matrix pencil method to estimate the param- eters of a sum of complex...for compressed sensing,” in ICIP, vol. 3, San Antonio , TX, Sep. 2007, pp. 117–120. [43] B. Fisher. (2012, Apr.) The earth mover’s distance. [Online

  17. Soil salinity prediction using electromagnetic induction method in gypsiferous soil

    Science.gov (United States)

    Bouksila, Fethi; Persson, Magnus; Bahri, Akiça; Berndtsson, Ronny; Ben Slimane, Abir

    2017-04-01

    In arid and semiarid regions, secondary soil salinization is considered a main danger to the sustainability of irrigated land and agricultural production. Thus, accurate and rapid estimation of soil salinity should be readily available to farmers during crop development to increase productivity and to contribute to sustainable land planning aimed at mitigating soil degradation. Measurement of electrical conductivity in saturated paste extracts (ECe) is a standard method for which other salinity estimation methods are referenced. In the present study, we investigated the possibilities to use the EM38 to predict field ECe in a saline gypsiferous soil of the Saharian-climate Fatnassa oasis (Tunisia) under shallow and saline groundwater. On the 114 ha oasis, an experimental network system of 27 agricultural plots was chosen for monitoring soil properties (ECa-EM38, soil particle size, gypsum content, soil moisture, and ECe) and groundwater (depth, Dgw, electrical conductivity, and ECgw). Samples were taken during 4 years (2001 to 2004) at experimental plots and soil profiles were sampled at 0.2 m depth intervals to 1.2 m for physical and chemical analysis. The results showed that significant lnECe-EM relationships could be developed. However, results also indicated that for better accuracy of soil salinity prediction using the EM38, it is advisable to perform calibrations for each measurement period.

  18. ALLTEM Multi-Axis Electromagnetic Induction System Demonstration and Validation

    Science.gov (United States)

    2011-11-17

    ALLTEM calibration tests have been compiled into a graphical display of background with no target and with a stainless steel ball set on the top (Tx-Z...25 October A1-1 Appendix 1 ALLTEM Calibration Data: Background and with Stainless Steel 4” Ball Data are presented in the following...and the current waveform that we apply to these loops is symmetric about zero amperes. In 2008 we replaced the CROWN power amplifier used to developed

  19. Use of Blended Approach in the Learning of Electromagnetic Induction

    CERN Document Server

    Chew, Charles

    2015-01-01

    This paper traces the importance of pedagogical content knowledge in the digital age to prepare today students for the 21st century. It highlights the need for ICT-based pedagogical models that are grounded in both the learning theories of constructivism and connectivism. One such suitable ICT-based pedagogical model is the TSOI Hybrid Learning Model. By means of a physics blended learning exemplar based on the TSOI Hybrid Learning Model, this paper argues for the use of blended learning approach as the way forward for 21st century teaching.

  20. Faraday's Investigation of Electromagnetic Induction. Experiment No. 21.

    Science.gov (United States)

    Devons, Samuel

    This paper focuses on Michael Faraday's experimental research in electricity in the 1830's. Historical notes related to his work are included as well as experiments, his objectives, and illustrations of equipment for the experiments. Examples from his diary are given so that students can attempt to emulate his honest and systematic manner of…

  1. Effect of the rate of temperature increase on water quality during heating in electromagnetic- and gas-heated pans.

    Science.gov (United States)

    Hiratsuka, Hiroshi; Sasaki, Ken

    2004-04-01

    More rapid increases in the pH value and hardness during electromagnetic heating of a pan of water were observed than when the pan was heated by LNG or LPG. The water quality changed universally in several tap water samples across Japan. This quality change was closely correlated with the rate of temperature increase, irrespective of heating by electromagnetic induction, LNG or LPG.

  2. Operator theory for electromagnetics an introduction

    CERN Document Server

    Hanson, George W

    2002-01-01

    The purpose of this book is to describe methods for solving problems in applied electromagnetic theory using basic concepts from functional anal­ ysis and the theory of operators. Although the book focuses on certain mathematical fundamentals, it is written from an applications perspective for engineers and applied scientists working in this area. Part I is intended to be a somewhat self-contained introduction to op­ erator theory and functional analysis, especially those elements necessary for application to problems in electromagnetics. The goal of Part I is to ex­ plain and synthesize these topics in a logical manner. Examples principally geared toward electromagnetics are provided. With the exception of Chapter 1, which serves as a review of basic electromagnetic theory, Part I presents definitions and theorems along with associated discussion and examples. This style was chosen because it allows one to readily identify the main concepts in a particular section. A proof is provided for all theorems who...

  3. Electromagnetic characteristics of carbon nanotube film materials

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2015-08-01

    Full Text Available Carbon nanotube (CNT possesses remarkable electrical conductivity, which shows great potential for the application as electromagnetic shielding material. This paper aims to characterize the electromagnetic parameters of a high CNT loading film by using waveguide method. The effects of layer number of CNT laminate, CNT alignment and resin impregnation on the electromagnetic characteristics were analyzed. It is shown that CNT film exhibits anisotropic electromagnetic characteristic. Pristine CNT film shows higher real part of complex permittivity, conductivity and shielding effectiveness when the polarized direction of incident wave is perpendicular to the winding direction of CNT film. For the CNT film laminates, complex permittivity increases with increasing layer number, and correspondingly, shielding effectiveness decreases. The five-layer CNT film shows extraordinary shielding performance with shielding effectiveness ranging from 67 dB to 78 dB in X-band. Stretching process induces the alignment of CNTs. When aligned direction of CNTs is parallel to the electric field, CNT film shows negative permittivity and higher conductivity. Moreover, resin impregnation into CNT film leads to the decrease of conductivity and shielding effectiveness. This research will contribute to the structural design for the application of CNT film as electromagnetic shielding materials.

  4. Magnetic flimmers: 'light in the electromagnetic darkness'.

    Science.gov (United States)

    Martens, Johannes W; Koehler, Peter J; Vijselaar, Joost

    2013-03-01

    Transcranial magnetic stimulation has become an important field for both research in neuroscience and for therapy since Barker in 1985 showed that it was possible to stimulate the human motor cortex with an electromagnet. Today for instance, transcranial magnetic stimulation can be used to measure nerve conduction velocities and to create virtual lesions in the brain. The latter option creates the possibility to inactivate parts of the brain temporarily without permanent damage. In 2008, the American Food and Drugs Administration approved repetitive transcranial magnetic stimulation as a therapy for major depression under strict conditions. Repetitive transcranial magnetic stimulation has not yet been cleared for treatment of other diseases, including schizophrenia, anxiety disorders, obesity and Parkinson's disease, but results seem promising. Transcranial magnetic stimulation, however, was not invented at the end of the 20th century. The discovery of electromagnetism, the enthusiasm for electricity and electrotherapy, and the interest in Beard's concept of neurasthenia already resulted in the first electromagnetic treatments in the late 19th and early 20th century. In this article, we provide a history of electromagnetic stimulation circa 1900. From the data, we conclude that Mesmer's late 18th century ideas of 'animal magnetism' and the 19th century absence of physiological proof had a negative influence on the acceptance of this therapy during the first decades of the 20th century. Electromagnetism disappeared from neurological textbooks in the early 20th century to recur at the end of that century.

  5. Mathematical Model and Computational Analysis of Selected Transient States of Cylindrical Linear Induction Motor Fed via Frequency Converter

    Directory of Open Access Journals (Sweden)

    Andrzej Rusek

    2008-01-01

    Full Text Available The mathematical model of cylindrical linear induction motor (C-LIM fed via frequency converter is presented in the paper. The model was developed in order to analyze numerically the transient states. Problems concerning dynamics of ac-machines especially linear induction motor are presented in [1 – 7]. Development of C-LIM mathematical model is based on circuit method and analogy to rotary induction motor. The analogy between both: (a stator and rotor windings of rotary induction motor and (b winding of primary part of C-LIM (inductor and closed current circuits in external secondary part of C-LIM (race is taken into consideration. The equations of C-LIM mathematical model are presented as matrix together with equations expressing each vector separately. A computational analysis of selected transient states of C-LIM fed via frequency converter is presented in the paper. Two typical examples of C-LIM operation are considered for the analysis: (a starting the motor at various static loads and various synchronous velocities and (b reverse of the motor at the same operation conditions. Results of simulation are presented as transient responses including transient electromagnetic force, transient linear velocity and transient phase current.

  6. Magnetic fields, special relativity and potential theory elementary electromagnetic theory

    CERN Document Server

    Chirgwin, B H; Kilmister, C W

    1972-01-01

    Magnetic Fields, Special Relativity and Potential Theory is an introduction to electromagnetism, special relativity, and potential theory, with emphasis on the magnetic field of steady currents (magnetostatics). Topics covered range from the origin of the magnetic field and the magnetostatic scalar potential to magnetization, electromagnetic induction and magnetic energy, and the displacement current and Maxwell's equations. This volume is comprised of five chapters and begins with an overview of magnetostatics, followed by a chapter on the methods of solving potential problems drawn from elec

  7. Selective Induction of Optical Magnetism.

    Science.gov (United States)

    Manna, Uttam; Lee, Jung-Hoon; Deng, Tian-Song; Parker, John; Shepherd, Nolan; Weizmann, Yossi; Scherer, Norbert F

    2017-12-13

    An extension of the Maxwell-Faraday law of electromagnetic induction to optical frequencies requires spatially appropriate materials and optical beams to create resonances and excitations with curl. Here we employ cylindrical vector beams with azimuthal polarization to create electric fields that selectively drive magnetic responses in dielectric core-metal nanoparticle "satellite" nanostructures. These optical frequency magnetic resonances are induced in materials that do not possess spin or orbital angular momentum. Multipole expansion analysis of the scattered fields obtained from electrodynamics simulations show that the excitation with azimuthally polarized beams selectively enhances magnetic vs electric dipole resonances by nearly 100-fold in experiments. Multipolar resonances (e.g., quadrupole and octupole) are enhanced 5-fold by focused azimuthally versus linearly polarized beams. We also selectively excite electric multipolar resonances in the same identical nanostructures with radially polarized light. This work opens new opportunities for spectroscopic investigation and control of "dark modes", Fano resonances, and magnetic modes in nanomaterials and engineered metamaterials.

  8. Electromagnetic fields and their impacts

    Science.gov (United States)

    Prša, M. A.; Kasaš-Lažetić, K. K.

    2018-01-01

    The main goal of this paper is to briefly recall some different electromagnetic field definitions, some macroscopic sources of electromagnetic fields, electromagnetic fields classification regarding time dependences, and the ways of field determination in concrete cases. After that, all the mechanisms of interaction between electromagnetic field and substance, on atomic level, are described in details. Interaction between substance and electric field is investigated separately from the substance and magnetic field interaction. It is demonstrated that, in all cases of the unique electromagnetic field, total interaction can be treated as a superposition of two separated interactions. Finally, the main electromagnetic fields surrounding us is cited and discussed.

  9. Predictive Direct Torque Control for Induction Motor Drive

    Science.gov (United States)

    Benzaioua, A.; Ouhrouche, M.; Merabet, A.

    2008-06-01

    A predictive control combined with the direct torque control (DTC) to induction motor drive is presented. A new switching strategy is used in DTC, where the constant switching frequency is taken constant, and the speed tracking is done by a predictive controller. The scheme control is applied to induction motor drive in order to perform the dynamic responses of electromagnetic torque, stator flux and speed. A comparison between the PI controller and predictive controller for speed tracking is done. Results of simulation show that the performance of the proposed control scheme for induction motor drive is accurately achieved.

  10. Metamaterial electromagnetic wave absorbers.

    Science.gov (United States)

    Watts, Claire M; Liu, Xianliang; Padilla, Willie J

    2012-06-19

    The advent of negative index materials has spawned extensive research into metamaterials over the past decade. Metamaterials are attractive not only for their exotic electromagnetic properties, but also their promise for applications. A particular branch-the metamaterial perfect absorber (MPA)-has garnered interest due to the fact that it can achieve unity absorptivity of electromagnetic waves. Since its first experimental demonstration in 2008, the MPA has progressed significantly with designs shown across the electromagnetic spectrum, from microwave to optical. In this Progress Report we give an overview of the field and discuss a selection of examples and related applications. The ability of the MPA to exhibit extreme performance flexibility will be discussed and the theory underlying their operation and limitations will be established. Insight is given into what we can expect from this rapidly expanding field and future challenges will be addressed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Applied electromagnetic scattering theory

    CERN Document Server

    Osipov, Andrey A

    2017-01-01

    Besides classical applications (radar and stealth, antennas, microwave engineering), scattering and diffraction are enabling phenomena for some emerging research fields (artificial electromagnetic materials or metamaterials, terahertz technologies, electromagnetic aspects of nano-science). This book is a tutorial for advanced students who need to study diffraction theory. The textbook gives fundamental knowledge about scattering and diffraction of electromagnetic waves and provides some working examples of solutions for practical high-frequency scattering and diffraction problems. The book focuses on the most important diffraction effects and mechanisms influencing the scattering process and describes efficient and physically justified simulation methods - physical optics (PO) and the physical theory of diffraction (PTD) - applicable in typical remote sensing scenarios. The material is presented in a comprehensible and logical form, which relates the presented results to the basic principles of electromag...

  12. Electromagnetic Basis of Metabolism and Heredity

    Science.gov (United States)

    Freund, Friedemann; Stolc, Viktor

    2016-01-01

    Living organisms control their cellular biological clocks to maintain functional oscillation of the redox cycle, also called the "metabolic cycle" or "respiratory cycle". Organization of cellular processes requires parallel processing on a synchronized time-base. These clocks coordinate the timing of all biochemical processes in the cell, including energy production, DNA replication, and RNA transcription. When this universal time keeping function is perturbed by exogenous induction of reactive oxygen species (ROS), the rate of metabolism changes. This causes oxidative stress, aging and mutations. Therefore, good temporal coordination of the redox cycle not only actively prevents chemical conflict between the reductive and oxidative partial reactions; it also maintains genome integrity and lifespan. Moreover, this universal biochemical rhythm can be disrupted by ROS induction in vivo. This in turn can be achieved by blocking the electron transport chain either endogenously or exogenously by various metabolites, e.g. hydrogen sulfide (H2S), highly diffusible drugs, and carbon monoxide (CO). Alternatively, the electron transport in vivo can be attenuated via a coherent or interfering transfer of energy from exogenous ultralow frequency (ULF) and extremely low frequency (ELF) electromagnetic (EM) fields, suggesting that-on Earth-such ambient fields are an omnipresent (and probably crucially important) factor for the time-setting basis of universal biochemical reactions in living cells. Our work demonstrated previously un-described evidence for quantum effects in biology by electromagnetic coupling below thermal noise at the universal electron transport chain (ETC) in vivo.

  13. Effect of Slot Combination and Skewed Slot on Electromagnetic Vibration of Capacitor Motor under Load

    Science.gov (United States)

    Hirotsuka, Isao; Tsuboi, Kazuo

    The capacitor motor (CRM) is widely used to drive industrial equipments and electric home appliances. Recently, the reduction in the vibration and noise of the CRM has become increasingly important from the standpoint of environmental improvement. However, the electromagnetic vibration of the CRM under load has not been analyzed sufficiently. Therefore, we have studied the electromagnetic vibration of CRM for the purpose of reducing it. In a previous paper, the relationships for a backward magnetic field, the equivalent circuit current, and the vibration of the CRM were clarified. The present paper theoretically and experimentally discusses the effect of the slot combination and skewed slot on the electromagnetic vibration of CRM under load. The primary conclusions are as follows: (1) In the case of 4-pole and 6-pole CRMs, the dominant electromagnetic vibration of CRMs was theoretically attributed to three types of electromagnetic force waves. Two types of electromagnetic force waves are generated: one wave is generated by the interaction of two forward magnetic fluxes, such as those of a three-phase squirrel-cage induction motor, and the other wave is generated under the influence of a backward magnetic flux. (2) The characteristics of dominant electromagnetic vibration depending on load and running capacitor were classified theoretically and experimentally into three types based on the characteristics of the electromagnetic force wave and equivalent circuit current. (3) The influences of magnetic saturation in dominant electromagnetic vibration were verified experimentally and their causes were clarified theoretically in relation to electromagnetic force waves.

  14. Development of Numerical Codes for Modeling Electromagnetic Behavior at High Frequencies Near Large Objects

    Science.gov (United States)

    Joshi, R. P.

    2003-01-01

    A study into the problem of determining electromagnetic solutions at high frequencies for problems involving complex geometries, large sizes and multiple sources (e.g. antennas) has been initiated. Typical applications include the behavior of antennas (and radiators) installed on complex conducting structures (e.g. ships, aircrafts, etc..) with strong interactions between antennas, the radiation patterns, and electromagnetic signals is of great interest for electromagnetic compatibility control. This includes the overall performance evaluation and control of all on-board radiating systems, electromagnetic interference, and personnel radiation hazards. Electromagnetic computational capability exists at NASA LaRC, and many of the codes developed are based on the Moment Method (MM). However, the MM is computationally intensive, and this places a limit on the size of objects and structures that can be modeled. Here, two approaches are proposed: (i) a current-based hybrid scheme that combines the MM with Physical optics, and (ii) an Alternating Direction Implicit-Finite Difference Time Domain (ADI-FDTD) method. The essence of a hybrid technique is to split the overall scattering surface(s) into two regions: (a) a MM zone (MMZ) which can be used over any part of the given geometry, but is most essential over irregular and "non-smooth" geometries, and (b) a PO sub-region (POSR). Currents induced on the scattering and reflecting surfaces can then be computed in two ways depending on whether the region belonged to the MMZ or was part of the POSR. For the MMZ, the current calculations proceed in terms of basis functions with undetermined coefficients (as in the usual MM method), and the answer obtained by solving a system of linear equations. Over the POSR, conduction is obtained as a superposition of two contributions: (i) currents due to the incident magnetic field, and (ii) currents produced by the mutual induction from conduction within the MMZ. This effectively leads to

  15. Electromagnetic fields stress living cells.

    Science.gov (United States)

    Blank, Martin; Goodman, Reba

    2009-08-01

    Electromagnetic fields (EMF), in both ELF (extremely low frequency) and radio frequency (RF) ranges, activate the cellular stress response, a protective mechanism that induces the expression of stress response genes, e.g., HSP70, and increased levels of stress proteins, e.g., hsp70. The 20 different stress protein families are evolutionarily conserved and act as 'chaperones' in the cell when they 'help' repair and refold damaged proteins and transport them across cell membranes. Induction of the stress response involves activation of DNA, and despite the large difference in energy between ELF and RF, the same cellular pathways respond in both frequency ranges. Specific DNA sequences on the promoter of the HSP70 stress gene are responsive to EMF, and studies with model biochemical systems suggest that EMF could interact directly with electrons in DNA. While low energy EMF interacts with DNA to induce the stress response, increasing EMF energy in the RF range can lead to breaks in DNA strands. It is clear that in order to protect living cells, EMF safety limits must be changed from the current thermal standard, based on energy, to one based on biological responses that occur long before the threshold for thermal changes.

  16. Electromagnetic compatibility engineering

    CERN Document Server

    Ott, Henry W

    2009-01-01

    Praise for Noise Reduction Techniques IN electronic systems ""Henry Ott has literally 'written the book' on the subject of EMC. . . . He not only knows the subject, but has the rare ability to communicate that knowledge to others.""-EE Times Electromagnetic Compatibility Engineering is a completely revised, expanded, and updated version of Henry Ott's popular book Noise Reduction Techniques in Electronic Systems. It reflects the most recent developments in the field of electromagnetic compatibility (EMC) and noise reduction¿and their practical applications t

  17. Electromagnetic fields and interactions

    CERN Document Server

    Becker, Richard L

    1964-01-01

    For more than a century, ""Becker"" and its forerunner, ""Abraham-Becker,"" have served as the bible of electromagnetic theory for countless students. This definitive translation of the physics classic features both volumes of the original text.Volume I, on electromagnetic theory, includes an introduction to vector and tensor calculus, the electrostatic field, electric current and the field, and the theory of relativity. The second volume comprises a self-contained introduction to quantum theory that covers the classical principles of electron theory and quantum mechanics, problems involving

  18. Lectures on electromagnetism

    CERN Document Server

    Das, Ashok

    2013-01-01

    These lecture notes on electromagnetism have evolved from graduate and undergraduate EM theory courses given by the author at the University of Rochester, with the basics presented with clarity and his characteristic attention to detail. The thirteen chapters cover, in logical sequence, topics ranging from electrostatics, magnetostatics and Maxwell's equations to plasmas and radiation. Boundary value problems are treated extensively, as are wave guides, electromagnetic interactions and fields. This second edition comprises many of the topics expanded with more details on the derivation of vari

  19. Electromagnetic fields in stratified media

    CERN Document Server

    Li, Kai

    2009-01-01

    Dealing with an important branch of electromagnetic theory with many useful applications in subsurface communication, radar, and geophysical prospecting and diagnostics, this book introduces electromagnetic theory and wave propagation in complex media.

  20. ABOUT THE URBAN ELECTROMAGNETIC POLLUTION

    National Research Council Canada - National Science Library

    Marius Lolea; Simona Dzitac

    2016-01-01

      This paper presents a brief statement of electromagnetic pollution generated by public sources of electromagnetic field, wich are distributed on the territory of City of Oradea, Bihor County, Romania...

  1. Millimeter waves: acoustic and electromagnetic.

    Science.gov (United States)

    Ziskin, Marvin C

    2013-01-01

    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. Copyright © 2012 Wiley Periodicals, Inc.

  2. The technology of electromagnetic radiation danger estimation using the hardware-software module

    Directory of Open Access Journals (Sweden)

    Titov Eugene

    2017-01-01

    Full Text Available The article describes the principles of functioning of the hardware-software module, whose purpose is the estimation of a danger level of the combined electromagnetic field influence on a human organism. The module consists of the hardware and the software parts. The hardware part is an array of electromagnetic parameter detectors; the software part is an electromagnetic field modelling program based on OpenEMS. The module creates so-called images of electromagnetic environment danger. The results show practical applicability of the technological module for the stated purpose.

  3. Ideal and nonideal electromagnetic cloaks

    OpenAIRE

    Zharova, Nina A.; Shadrivov, Ilya V.; Zharov, Alexander A.; Kivshar, Yuri S.

    2008-01-01

    We employ the analytical results for the spatial transformation of the electromagnetic fields to obtain and analyze explicit expressions for the structure of the electromagnetic fields in invisibility cloaks, beam splitters, and field concentrators. We study the efficiency of nonideal electromagnetic cloaks and discuss the effect of scattering losses on the cloak invisibility.

  4. Induction interview form in EDH

    CERN Multimedia

    Information technology Department, AIS (Administrative Information Services) Group,

    2007-01-01

    As part of the efforts to rationalise administrative procedures, the IT and HR Departments have developed a new EDH form for induction interviews, which can be accessed using the link below. In accordance with Administrative Circular No. 2 ('Recruitment, Appointment and possible developments regarding the contractual position of Staff Members', Rev. 3), the work and training objectives to be achieved during the probation period shall be specified in writing to all new staff members during an induction interview. The interview shall take place between the new staff member and his supervisor within six weeks of him taking up his duties at the latest. https://edh.cern.ch/Document/MAPS/Induction (or from the EDH desktop, by clicking on 'Other Tasks' and going to the 'HR & Training' heading) Please note that this form is to be used exclusively for new staff members. A separate EDH form will be developed for fellows. Information technology Department, AIS (Administrative Information Services) Group Human...

  5. Induction interview form in EDH

    CERN Multimedia

    Information technology Department, AIS (Administrative Information Services) Group

    2007-01-01

    As part of the efforts to rationalise administrative procedures, the IT and HR Departments have developed a new EDH form for induction interviews, which can be accessed using the link below. In accordance with Administrative Circular No. 2 ('Recruitment, Appointment and possible developments regarding the contractual position of Staff Members', Rev. 3), the work and training objectives to be achieved during the probation period shall be specified in writing to all new staff members during an induction interview. The interview shall take place between the new staff member and his supervisor within six weeks of his taking up his duties at the latest. https://edh.cern.ch/Document/MAPS/Induction1) (or from the EDH desktop, by clicking on 'Other Tasks' and going to the 'HR & Training' heading) Please note that this form is to be used exclusively for new staff members. A separate EDH form will be developed for fellows.Information technology Department, AIS (Administrative Information Services) Group Human Re...

  6. Self-Sensing Electromagnets for Robotic Tooling Systems: Combining Sensor and Actuator

    Directory of Open Access Journals (Sweden)

    Tobias Kamf

    2016-08-01

    Full Text Available A low-cost method, which integrates distance sensing functionality into a switched electromagnet by using a hybrid switching mode and current ripple measurements, is proposed. The electromagnet is controlled by a micro-controller via a MOSFET H bridge, utilizing a comparator-based current control. Additionally, a method for calculating the inductance of the electromagnet and approximating the magnetic contact between the electromagnet and its target is also presented. The resulting tool is attached to an industrial robot, and the system performance using this setup is evaluated. Distance sensing in the range of 0 mm to 5.2 mm is demonstrated. It is also shown that the relation between magnetic contact, coil current and calculated inductance can be reduced to a predictive look-up table, enabling the quality of the magnetic contact to be estimated using minimal computational effort.

  7. Induction and direct resistance heating theory and numerical modeling

    CERN Document Server

    Lupi, Sergio; Aliferov, Aleksandr

    2015-01-01

    This book offers broad, detailed coverage of theoretical developments in induction and direct resistance heating and presents new material on the solution of problems in the application of such heating. The physical basis of induction and conduction heating processes is explained, and electromagnetic phenomena in direct resistance and induction heating of flat workpieces and cylindrical bodies are examined in depth. The calculation of electrical and energetic characteristics of induction and conduction heating systems is then thoroughly reviewed. The final two chapters consider analytical solutions and numerical modeling of problems in the application of induction and direct resistance heating, providing industrial engineers with the knowledge needed in order to use numerical tools in the modern design of installations. Other engineers, scientists, and technologists will find the book to be an invaluable reference that will assist in the efficient utilization of electrical energy.

  8. Electromagnetic radiation detector

    Science.gov (United States)

    Benson, Jay L.; Hansen, Gordon J.

    1976-01-01

    An electromagnetic radiation detector including a collimating window, a cathode member having a photoelectric emissive material surface angularly disposed to said window whereby radiation is impinged thereon at acute angles, an anode, separated from the cathode member by an evacuated space, for collecting photoelectrons emitted from the emissive cathode surface, and a negatively biased, high transmissive grid disposed between the cathode member and anode.

  9. Introduction to electromagnetic compatibility

    Science.gov (United States)

    Paul, Clayton R.

    A formal and extensive treatment of electromagnetic compatibility (EMC) is presented. Basic principles are reviewed in detail, including reasons for EMC in electronic design. Also discussed are: nonideal behavior of components, signal spectra, radiated emission and susceptibility, conducted emissions and susceptibility, crosstalk, shielding, electrostatic discharge, and system design for EMC.

  10. What Are Electromagnetic Fields?

    Science.gov (United States)

    ... them to quickly heat food. At radio frequencies, electric and magnetic fields are closely interrelated and we typically measure their levels as power densities in watts per square metre (W/m 2 ). Key points: The electromagnetic spectrum encompasses both natural and ...

  11. Electromagnetic distance measurement

    CERN Document Server

    1967-01-01

    This book brings together the work of forty-eight geodesists from twenty-five countries. They discuss various new electromagnetic distance measurement (EDM) instruments - among them the Tellurometer, Geodimeter, and air- and satellite-borne systems - and investigate the complex sources of error.

  12. Simple Superconducting "Permanent" Electromagnet

    Science.gov (United States)

    Israelson, Ulf E.; Strayer, Donald M.

    1992-01-01

    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.

  13. Nanofocusing of electromagnetic radiation

    DEFF Research Database (Denmark)

    Gramotnev, D. K.; Bozhevolnyi, Sergey I.

    2014-01-01

    Nanofocusing of electromagnetic radiation, that is, reducing the cross sections of propagating optical modes far beyond the diffraction limit in dielectric media, can be achieved in tapered metal-dielectric waveguides that support surface plasmon-polariton modes. Although the main principles...

  14. "Hearing" Electromagnetic Waves

    Science.gov (United States)

    Rojo, Marta; Munoz, Juan

    2014-01-01

    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…

  15. Electromagnetic structure of nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R.G.

    1986-07-01

    A brief review is given of selected topics in the electromagnetic structure of nucleons and nuclei, including nucleon form factors from both quantum chromodynamics and electron scattering data, measurements of the deuteron and triton form factors, quasi-elastic scattering, and the EMC effect. 47 refs., 13 figs. (LEW)

  16. Faraday: Father of Electromagnetism

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 7; Issue 3. Faraday: Father of Electromagnetism. S V Bhat. General Article Volume 7 Issue 3 March 2002 pp 46-50. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/007/03/0046-0050. Keywords. Faraday ...

  17. Low inductance gas switching.

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, Ray; Harjes, Henry Charles III; Wallace, Zachariah; Elizondo, Juan E.

    2007-10-01

    The laser trigger switch (LTS) is a key component in ZR-type pulsed power systems. In ZR, the pulse rise time through the LTS is > 200 ns and additional stages of pulse compression are required to achieve the desired <100 ns rise time. The inductance of the LTS ({approx}500nH) in large part determines the energy transfer time through the switch and there is much to be gained in improving system performance and reducing system costs by reducing this inductance. The current path through the cascade section of the ZR LTS is at a diameter of {approx} 6-inches which is certainly not optimal from an inductance point of view. The LTS connects components of much greater diameter (typically 4-5 feet). In this LDRD the viability of switch concepts in which the diameter of cascade section is greatly increased have been investigated. The key technical question to be answered was, will the desired multi-channel behavior be maintained in a cascade section of larger diameter. This LDRD proceeded in 2 distinct phases. The original plan for the LDRD was to develop a promising switch concept and then design, build, and test a moderate scale switch which would demonstrate the key features of the concept. In phase I, a switch concept which meet all electrical design criteria and had a calculated inductance of 150 nH was developed. A 1.5 MV test switch was designed and fabrication was initiated. The LDRD was then redirected due to budgetary concerns. The fabrication of the switch was halted and the focus of the LDRD was shifted to small scale experiments designed to answer the key technical question concerning multi-channel behavior. In phase II, the Multi-channel switch test bed (MCST) was designed and constructed. The purpose of MCST was to provide a versatile, fast turn around facility for the study the multi-channel electrical breakdown behavior of a ZR type cascade switch gap in a parameter space near that of a ZR LTS. Parameter scans on source impedance, gap tilt, gap spacing and

  18. FEATURES OF THREE-DIMENSIONAL SIMULATION OF THE ELECTROMAGNETIC FIELDS OF THE ASYNCHRONOUS MOTORS

    Directory of Open Access Journals (Sweden)

    D. S. Yarymbash

    2016-12-01

    Full Text Available Purpose. Development of new effective approach for the realization of three-dimensional mathematical model of transient electrical and magnetic fields in induction motors, which based on their design features, the nonlinearity of the electrical and magnetic properties of the active and structural materials, which provides adequacy or high simulation accuracy. Research methods. Numerical simulation of the conjugate spatial transient electrical and magnetic fields of the induction motor in the mode of short-circuit, with the help of methods of the theory of electromagnetic fields, finite element, theory of electrical machines and electrical circuits. The obtained results. Theoretical researches and simulation results, which based on numerical realization of the finite element method of three-dimensional mathematical model of the induction motor are obtained. Theoretical researches indicate the features of electrical and magnetic processes of AC power conversion in a short circuit mode. In the area of the coil ends of the low power asynchronous motor it is allocated to 12,5% of the total energy of its magnetic field, which is mainly localized in the active part of the stator, the rotor and the air gap. In the central area of the active part of the induction motor, the length is up to 60% of the total length of the stator and rotor core, the magnetic field has plane-parallel form, but is transformed into zones of coil ends of the stator windings, and near of its core end. The features of the magnetic field and energy distribution, which have a significant effect on the parameters of a short-circuit of small power induction motor and its operating modes are defined. Scientific novelty. The regularities of the distribution of the induction and magnetic field energy in the short-circuit mode and their quantitative relation for active zone and the area of the coil ends of the stator windings of the low-power asynchronous motors are defined. Practical

  19. Constraining the Composition of the Earth from Long-period Electromagnetic Sounding of the Lower Mantle

    DEFF Research Database (Denmark)

    Khan, A.; Connolly, J.; Olsen, Nils

    We reexamine the problem of inverting global transfer functions to constrain the internal structure of the Earth. We go beyond the conventional approach of inverting electromagnetic induction data by inverting directly for chemical composition and thermal state, using the model system Ca...... measurements to estimate the bulk lunar electrical conductivity structure from which transfer functions are calculated. To further constrain the radial density profile in the inversion we added constraints imposed by mass and moment of inertia. Our results indicate that electromagnetic sounding...

  20. The plane wave spectrum representation of electromagnetic fields

    CERN Document Server

    Clemmow, P C

    1966-01-01

    The Plane Wave Spectrum Representation of Electromagnetic Fields presents the theory of the electromagnetic field with emphasis to the plane wave. This book explains how fundamental electromagnetic fields can be represented by the superstition of plane waves traveling in different directions. Organized into two parts encompassing eight chapters, this book starts with an overview of the methods whereby plane wave spectrum representation can be used in attacking different characteristic problems belonging to the theories of radiation, diffraction, and propagation. This book then discusses the co

  1. Applied Computational Electromagnetics Society Journal, Volume 9, Number 2

    Science.gov (United States)

    1994-07-01

    of the element software construction.’ International quasilinear Poisson equation on a nonuniform Journal for Applied Electromagnetics in triangle mesh...eigenvectors of H we orthogoaul, bodi sides of (14) can be multiplied by each of Aguaw 8 Doube aided motor with erlwanent tem eganvecton; to obtain...of induction, dicted by (1) the continuity equation and Poisson -s the other solving the complete lossy wave equation) equation and by (2) the

  2. Health Effects of Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    Peter Gajšek

    2011-02-01

    Full Text Available Abstract: Devices that emit electromagnetic fields (EMF have become a part of our daily life and can be found in telecommunications, industry, traffic, science, medicine and in every household. Due to the fact that general public is massively exposed to the EMF, even very small health effects could become a serious public health problem. Many studies show that the EMF above a certain threshold can have a negative health impact. The studies, which could explain the question of health risks as a result of chronic exposure to low intensities, are often contradictory and deficient. In this review the state of the art in the field of health risks associated with the EMF exposure in our environment is presented.

  3. Effect of coupling currents on the dynamic inductance during fast transient in superconducting magnets

    Directory of Open Access Journals (Sweden)

    V. Marinozzi

    2015-03-01

    Full Text Available We present electromagnetic models aiming to calculate the variation of the inductance in a magnet due to dynamic effects such as the variation of magnetization or the coupling with eddy currents. The models are studied with special regard to the calculation of the inductance in superconducting magnets which are affected by interfilament coupling currents. The developed models have been compared with experimental data coming from tests of prototype Nb_{3}Sn magnets designed for the new generation of accelerators. This work is relevant for the quench protection study of superconducting magnets: quench is an unwanted event, when part of the magnet becomes resistive; in these cases, the current should be discharged as fast as possible, in order to maintain the resistive zone temperature under a safe limit. The magnet inductance is therefore a relevant term for the description of the current discharge, especially for the high-field new generation superconducting magnets for accelerators, and this work shows how to calculate the correct value during rapid current changes, providing a mean for simulations of the reached temperature.

  4. Inductive Monitoring System (IMS)

    Data.gov (United States)

    National Aeronautics and Space Administration — IMS: Inductive Monitoring System The Inductive Monitoring System (IMS) is a tool that uses a data mining technique called clustering to extract models of normal...

  5. Electromagnetic interference with cardiac pacemakers and implantable cardioverter-defibrillators from low-frequency electromagnetic fields in vivo.

    Science.gov (United States)

    Tiikkaja, Maria; Aro, Aapo L; Alanko, Tommi; Lindholm, Harri; Sistonen, Heli; Hartikainen, Juha E K; Toivonen, Lauri; Juutilainen, Jukka; Hietanen, Maila

    2013-03-01

    Electromagnetic interference (EMI) can pose a danger to workers with pacemakers and implantable cardioverter-defibrillators (ICDs). At some workplaces electromagnetic fields are high enough to potentially inflict EMI. The purpose of this in vivo study was to evaluate the susceptibility of pacemakers and ICDs to external electromagnetic fields. Eleven volunteers with a pacemaker and 13 with an ICD were exposed to sine, pulse, ramp, and square waveform magnetic fields with frequencies of 2-200 Hz using Helmholtz coil. The magnetic field flux densities varied to 300 µT. We also tested the occurrence of EMI from an electronic article surveillance (EAS) gate, an induction cooktop, and a metal inert gas (MIG) welding machine. All pacemakers were tested with bipolar settings and three of them also with unipolar sensing configurations. None of the bipolar pacemakers or ICDs tested experienced interference in any of the exposure situations. The three pacemakers with unipolar settings were affected by the highest fields of the Helmholtz coil, and one of them also by the EAS gate and the welding cable. The induction cooktop did not interfere with any of the unipolarly programmed pacemakers. Magnetic fields with intensities as high as those used in this study are rare even in industrial working environments. In most cases, employees can return to work after implantation of a bipolar pacemaker or an ICD, after an appropriate risk assessment. Pacemakers programmed to unipolar configurations can cause danger to their users in environments with high electromagnetic fields, and should be avoided, if possible.

  6. CALCULATION OF INDUCTANCE OF THE INTERIOR PERMANENT MAGNET SYNCHRONOUS MOTOR

    Directory of Open Access Journals (Sweden)

    Phyong Le Ngo

    2017-01-01

    Full Text Available Interior permanent magnet synchronous motor (IPMSM refers to salient-pole synchronous motors, characterized by inequality of inductances of longitudinal (d and transverse (q axes. Electromagnetic torque of IPMSM consists of two components: active torque and reactive torque; the latter depends on inductances of d and q axes. An analytical method to calculate own inductances and mutual inductances of a three-phase IPMSM is presented. Distributed windings of the stator are substituted by equivalent sine distributed windings. An interior permanent magnets rotor is substituted by an equivalent salient-pole rotor. Sections of a magnetic circuit comprising interior permanent magnets, air barriers and steel bridges are substituted by equivalent air-gap. The expressions of the magnetic induction created by current of the stator windings at each point of the air gap as well as of magnetic flux linkage of the stator windings have been obtained. The equations of the self-inductances of phases A, B, C, and of inductance of mutual induction are determined from magnetic flux linkage. The inductance of the d and q axes have been obtained as a result of transformation of the axes abc–dq. The results obtained with the use of the proposed analytical method and the finite element method are presented in the form of a graph; the calculations that have been obtained by these two methods were compared. 

  7. Electromagnetic radiation related to dislocation dynamics in a seismic preparation zone

    Directory of Open Access Journals (Sweden)

    T. Ernst

    2002-06-01

    Full Text Available Electromagnetic emission is observed frequently before earthquakes as high noise level in VLF and ULF bands. We present theoretical considerations on electromagnetic radiation caused by dislocation dynamics in the preseismic micro-sources (micro-crackings located in an earthquake preparation zone. Some of these micro-sources could be located near the ground surface and their electromagnetic signals could be accesible in some recording stations. The examples of the numerically simulated induction and radiation fields are given and one example of the observed radio-noise recording is shown.

  8. Electromagnetic wave energy converter

    Science.gov (United States)

    Bailey, R. L. (Inventor)

    1973-01-01

    Electromagnetic wave energy is converted into electric power with an array of mutually insulated electromagnetic wave absorber elements each responsive to an electric field component of the wave as it impinges thereon. Each element includes a portion tapered in the direction of wave propagation to provide a relatively wideband response spectrum. Each element includes an output for deriving a voltage replica of the electric field variations intercepted by it. Adjacent elements are positioned relative to each other so that an electric field subsists between adjacent elements in response to the impinging wave. The electric field results in a voltage difference between adjacent elements that is fed to a rectifier to derive dc output power.

  9. Electromagnetic Polarizabilities of Mesons

    Science.gov (United States)

    Aleksejevs, A.; Barkanova, S.

    2016-04-01

    The Chiral Perturbation Theory (CHPT) has been very successful in describing low-energy hadronic properties in the non-perturbative regime of Quantum Chromodynamics. The results of ChPT, many of which are currently under active experimental investigation, provide stringent predictions of many fundamental properties of hadrons, including quantities such as electromagnetic polarizabilities. Yet, even for the simplest hadronic system, a pion, we still have a broad spectrum of polarizability measurements (MARK II, VENUS, ALEPH, TPC/2g, CELLO, Belle, Crystal Ball). The meson polarizability can be accessed through Compton scattering, so we can measure it through Primakoff reaction. This paper will provide an analysis of the CHPT predictions of the SU(3) meson electromagnetic polarizabilities and outline their relationship to the Primakoff cross section at the kinematics relevant to the planned JLab experiments.

  10. The KLOE electromagnetic calorimeter

    CERN Document Server

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

    2002-01-01

    The KLOE detector was designed primarily for the study of CP violation in neutral kaon decays at DAPHINE, the Frascati phi-factory. The detector consists of a tracker and an electromagnetic calorimeter. A lead-scintillating-fiber sampling calorimeter satisfies best the requirements of the experiment, providing adequate energy resolution and superior timing accuracy. We describe in the following the construction of the calorimeter, its calibration and how the calorimeter information is used to obtain energy, point of entry and time of the arrival of photons, electrons and charged particles. With e sup + e sup - collision data at DAPHINE for an integrated luminosity of some 2 pb sup - sup 1 we find for electromagnetic showers, an energy resolution of 5.7%/sq root E(GeV) and a time resolution of 54/sq root E(GeV) ps. We also present a measurement of efficiency for low energy photons.

  11. Electromagnetic fields and waves

    CERN Document Server

    Iskander, Magdy F

    2013-01-01

    The latest edition of Electromagnetic Fields and Waves retains an authoritative, balanced approach, in-depth coverage, extensive analysis, and use of computational techniques to provide a complete understanding of electromagnetic—important to all electrical engineering students. An essential feature of this innovative text is the early introduction of Maxwell's equations, together with the quantifying experimental observations made by the pioneers who discovered electromagnetics. This approach directly links the mathematical relations in Maxwell's equations to real experiments and facilitates a fundamental understanding of wave propagation and use in modern practical applications, especially in today's wireless world. New and expanded topics include the conceptual relationship between Coulomb's law and Gauss's law for calculating electric fields, the relationship between Biot-Savart's and Ampere's laws and their use in calculating magnetic fields from current sources, the development of Faraday's law from e...

  12. Introduction to electromagnetic theory

    CERN Document Server

    Owen, George E

    2003-01-01

    A direct, stimulating approach to electromagnetic theory, this text employs matrices and matrix methods for the simple development of broad theorems. The author uses vector representation throughout the book, with numerous applications of Poisson's equation and the Laplace equation (the latter occurring in both electronics and magnetic media). Contents include the electrostatics of point charges, distributions of charge, conductors and dielectrics, currents and circuits, and the Lorentz force and the magnetic field. Additional topics comprise the magnetic field of steady currents, induced ele

  13. Electromagnetic Interaction Equations

    OpenAIRE

    Zinoviev, Yury M.

    2009-01-01

    For the electromagnetic interaction of two particles the relativistic quantum mechanics equations are proposed. These equations are solved for the case when one particle has a small mass and moves freely. The initial wave functions are supposed to be concentrated at the coordinates origin. The energy spectrum of another particle wave function is defined by the initial wave function of the free moving particle. Choosing the initial wave function of the free moving particle it is possible to ob...

  14. Induction machine handbook

    CERN Document Server

    Boldea, Ion

    2002-01-01

    Often called the workhorse of industry, the advent of power electronics and advances in digital control are transforming the induction motor into the racehorse of industrial motion control. Now, the classic texts on induction machines are nearly three decades old, while more recent books on electric motors lack the necessary depth and detail on induction machines.The Induction Machine Handbook fills industry's long-standing need for a comprehensive treatise embracing the many intricate facets of induction machine analysis and design. Moving gradually from simple to complex and from standard to

  15. Electromagnetic absorption properties of spacecraft and space debris

    Science.gov (United States)

    Micheli, D.; Santoni, F.; Giusti, A.; Delfini, A.; Pastore, R.; Vricella, A.; Albano, M.; Arena, L.; Piergentili, F.; Marchetti, M.

    2017-04-01

    Aim of the work is to present a method to evaluate the electromagnetic absorption properties of spacecraft and space debris. For these objects, the radar detection ability depends mainly on volume, shape, materials type and other electromagnetic reflecting behaviour of spacecraft surface components, such as antennas or thermal blankets, and of metallic components in space debris. The higher the electromagnetic reflection coefficient of such parts, the greater the radar detection possibility. In this research an electromagnetic reverberation chamber is used to measure the absorption cross section (ACS) of four objects which may represent space structure operating components as well as examples of space debris: a small satellite, a composite antenna dish, a Thermal Protection System (TPS) tile and a carbon-based composite missile shell. The ACS mainly depends on geometrical characteristics like apertures, face numbers and bulk porosity, as well as on the type of the material itself. The ACS, which is an electromagnetic measurement, is expressed in squared meters and thus can be compared with the objects geometrical cross section. A small ACS means a quite electromagnetic reflective tendency, which is beneficial for radar observations; on the contrary, high values of ACS indicate a strong absorption of the electromagnetic field, which in turn can result a critical hindering of radar tracking.

  16. Electromagnetic field and cosmic censorship

    CERN Document Server

    Düztaş, Koray

    2013-01-01

    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.

  17. Electromagnetic Scattering and Material Characterization

    CERN Document Server

    Omar, Abbas

    2011-01-01

    Based on the author's more-than 30 years of experience, this first-of-its-kind volume presents a comprehensive and systematic analysis of electromagnetic fields and their scattering by material objects. The book considers all three categories of scattering environments commonly used for material measurements – unbounded regions, waveguides, and cavity resonators. The book covers such essential topics as electromagnetic field propagation, radiation, and scattering, containing mathematically rigorous approaches for the computation of electromagnetic fields and the explanation of their behavior.

  18. Electromagnetic Meissner-Effect Launcher

    Science.gov (United States)

    Robertson, Glen A.

    1990-01-01

    Proposed electromagnetic Meissner-effect launching apparatus differs from previous electromagnetic launchers; no need for electromagnet coil on projectile. Result, no need for brush contacts and high-voltage commutation equipment to supply current directly to projectile coil, or for pulse circuitry to induce current in projectile coil if brush contacts not used. Compresses magnetic field surrounding rear surface of projectile, creating gradient of magnetic pressure pushing projectile forward.

  19. Induction Heating Model of Cermet Fuel Element Environmental Test (CFEET)

    Science.gov (United States)

    Gomez, Carlos F.; Bradley, D. E.; Cavender, D. P.; Mireles, O. R.; Hickman, R. R.; Trent, D.; Stewart, E.

    2013-01-01

    Deep space missions with large payloads require high specific impulse and relatively high thrust to achieve mission goals in reasonable time frames. Nuclear Thermal Rockets (NTR) are capable of producing a high specific impulse by employing heat produced by a fission reactor to heat and therefore accelerate hydrogen through a rocket nozzle providing thrust. Fuel element temperatures are very high (up to 3000 K) and hydrogen is highly reactive with most materials at high temperatures. Data covering the effects of high-temperature hydrogen exposure on fuel elements are limited. The primary concern is the mechanical failure of fuel elements due to large thermal gradients; therefore, high-melting-point ceramics-metallic matrix composites (cermets) are one of the fuels under consideration as part of the Nuclear Cryogenic Propulsion Stage (NCPS) Advance Exploration System (AES) technology project at the Marshall Space Flight Center. The purpose of testing and analytical modeling is to determine their ability to survive and maintain thermal performance in a prototypical NTR reactor environment of exposure to hydrogen at very high temperatures and obtain data to assess the properties of the non-nuclear support materials. The fission process and the resulting heating performance are well known and do not require that active fissile material to be integrated in this testing. A small-scale test bed; Compact Fuel Element Environmental Tester (CFEET), designed to heat fuel element samples via induction heating and expose samples to hydrogen is being developed at MSFC to assist in optimal material and manufacturing process selection without utilizing fissile material. This paper details the analytical approach to help design and optimize the test bed using COMSOL Multiphysics for predicting thermal gradients induced by electromagnetic heating (Induction heating) and Thermal Desktop for radiation calculations.

  20. Electromagnetic fields in biological systems

    National Research Council Canada - National Science Library

    Lin, James C

    2012-01-01

    "Focusing on exposure, induced fields, and absorbed energy, this volume covers the interaction of electromagnetic fields and waves with biological systems, spanning static fields to terahertz waves...

  1. Electromagnetic waves in stratified media

    CERN Document Server

    Wait, James R; Fock, V A; Wait, J R

    2013-01-01

    International Series of Monographs in Electromagnetic Waves, Volume 3: Electromagnetic Waves in Stratified Media provides information pertinent to the electromagnetic waves in media whose properties differ in one particular direction. This book discusses the important feature of the waves that enables communications at global distances. Organized into 13 chapters, this volume begins with an overview of the general analysis for the electromagnetic response of a plane stratified medium comprising of any number of parallel homogeneous layers. This text then explains the reflection of electromagne

  2. Battlefield Electromagnetic Environments Office (BEEO)

    Data.gov (United States)

    Federal Laboratory Consortium — The Battlefield Electromagnetic Environments Office (BEEO) develops, maintains, and operates the Army Materiel Command (AMC) databases for spectrum management, per...

  3. Method of moments in electromagnetics

    CERN Document Server

    Gibson, Walton C

    2007-01-01

    Responding to the need for a clear, up-to-date introduction to the field, The Method of Moments in Electromagnetics explores surface integral equations in electromagnetics and presents their numerical solution using the method of moments (MOM) technique. It provides the numerical implementation aspects at a nuts-and-bolts level while discussing integral equations and electromagnetic theory at a higher level. The author covers a range of topics in this area, from the initial underpinnings of the MOM to its current applications. He first reviews the frequency-domain electromagnetic theory and t

  4. Forward modeling. Route to electromagnetic inversion

    Energy Technology Data Exchange (ETDEWEB)

    Groom, R.; Walker, P. [PetRos EiKon Incorporated, Ontario (Canada)

    1996-05-01

    Inversion of electromagnetic data is a topical subject in the literature, and much time has been devoted to understanding the convergence properties of various inverse methods. The relative lack of success of electromagnetic inversion techniques is partly attributable to the difficulties in the kernel forward modeling software. These difficulties come in two broad classes: (1) Completeness and robustness, and (2) convergence, execution time and model simplicity. If such problems exist in the forward modeling kernel, it was demonstrated that inversion can fail to generate reasonable results. It was suggested that classical inversion techniques, which are based on minimizing a norm of the error between data and the simulated data, will only be successful when these difficulties in forward modeling kernels are properly dealt with. 4 refs., 5 figs.

  5. Mathematical models and numerical simulation in electromagnetism

    CERN Document Server

    Bermúdez, Alfredo; Salgado, Pilar

    2014-01-01

    The book represents a basic support for a master course in electromagnetism oriented to numerical simulation. The main goal of the book is that the reader knows the boundary-value problems of partial differential equations that should be solved in order to perform computer simulation of electromagnetic processes. Moreover it includes a part devoted to electric circuit theory  based on ordinary differential equations. The book is mainly oriented to electric engineering applications, going from the general to the specific, namely, from the full Maxwell’s equations to the particular cases of electrostatics, direct current, magnetostatics and eddy currents models. Apart from standard exercises related to analytical calculus, the book includes some others oriented to real-life applications solved with MaxFEM free simulation software.

  6. Electromagnetic probes in heavy-ion collisions

    Directory of Open Access Journals (Sweden)

    van Hees H.

    2015-01-01

    Full Text Available Due to their penetrating nature, electromagnetic probes, i.e., lepton-antilepton pairs (dileptons and photons are unique tools to gain insight into the nature of the hot and dense medium of strongly-interacting particles created in relativistic heavy-ion collisions, including hints to the nature of the restoration of chiral symmetry of QCD. Of particular interest are the spectral properties of the electromagnetic current-correlation function of these particles within the dense and/or hot medium. The related theoretical investigations of the in-medium properties of the involved particles in both the partonic and hadronic part of the QCD phase diagram underline the importance of a proper understanding of the properties of various hadron resonances in the medium.

  7. Handbook of electromagnetic compatibility

    CERN Document Server

    1995-01-01

    This""know-how""book gives readers a concise understanding of the fundamentals of EMC, from basic mathematical and physical concepts through present, computer-age methods used in analysis, design, and tests. With contributions from leading experts in their fields, the text provides a comprehensive overview. Fortified with information on how to solve potential electromagnetic interference (EMI) problems that may arise in electronic design, practitioners will be betterable to grasp the latest techniques, trends, and applications of this increasingly important engineering discipline.Handbook of E

  8. Introduction to electromagnetic engineering

    CERN Document Server

    Harrington, Roger E

    2003-01-01

    This study of electromagnetic theory introduces students to a broad range of quantities and concepts, imparting the necessary vector analysis and associated mathematics and reinforcing its teachings with several elementary field problems. Based on circuit theory rather than on the classical force-relationship approach, the text uses the theory of electric circuits to provide a system of experiments already familiar to the electrical engineer; a series of field concepts are then introduced as a logical extension of circuit theory. Virtually unobtainable elsewhere, this text was written by a pr

  9. Electromagnetic Meissner effect launcher

    Science.gov (United States)

    Robertson, Glen A. (Inventor)

    1991-01-01

    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.

  10. Information Architecture without Internal Theory: An Inductive Design Process.

    Science.gov (United States)

    Haverty, Marsha

    2002-01-01

    Suggests that information architecture design is primarily an inductive process, partly because it lacks internal theory and partly because it is an activity that supports emergent phenomena (user experiences) from basic design components. Suggests a resemblance to Constructive Induction, a design process that locates the best representational…

  11. Genotoxic effects of exposure to radiofrequency electromagnetic fields (RF-EMF) in HL-60 cells are not reproducible.

    Science.gov (United States)

    Speit, Günter; Gminski, Richard; Tauber, Rudolf

    2013-08-15

    Conflicting results have been published regarding the induction of genotoxic effects by exposure to radiofrequency electromagnetic fields (RF-EMF). Various results indicating a genotoxic potential of RF-EMF were reported by the collaborative EU-funded REFLEX (Risk Evaluation of Potential Environmental Hazards From Low Energy Electromagnetic Field Exposure Using Sensitive in vitro Methods) project. There has been a long-lasting scientific debate about the reliability of the reported results and an attempt to reproduce parts of the results obtained with human fibroblasts failed. Another part of the REFLEX study was performed in Berlin with the human lymphoblastoid cell line HL-60; genotoxic effects of RF-EMF were measured by means of the comet assay and the micronucleus test. The plausibility and reliability of these results were also questioned. In order to contribute to a clarification of the biological significance of the reported findings, a repeat study was performed, involving scientists of the original study. Comet-assay experiments and micronucleus tests were performed under the same experimental conditions that had led to genotoxic effects in the REFLEX study. Here we report that the attempts to reproduce the induction of genotoxic effects by RF-EMF in HL-60 cells failed. No genotoxic effects of RF-EMF were measured in the repeat experiments. We could not find an explanation for the conflicting results. However, the negative repeat experiments suggest that the biological significance of genotoxic effects of RF-EMF reported by the REFLEX study should be re-assessed. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Metamaterials beyond electromagnetism

    Science.gov (United States)

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

    2013-12-01

    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.

  13. Device for side induction sensing

    Energy Technology Data Exchange (ETDEWEB)

    Bilibin, S.I.; Byalyy, Yu.V.; Malyshev, D.A.; Orlov, V.N.; Ovchinnikov, A.Ye.; Plyusnin, N.I.

    1982-01-01

    The device can be used to determine geophysical parameters of the beds at the zone of penetration of the drilling mud filtrate. Improvement in information content of sensing is attained by increasing the quantity of induction probes formed by the coils, and improvement in sensing accuracy by conducting measurements on one fixed part with time separation of the signals from different induction probes. The system of separation of the measurable signals is done in the form of a group of commutators and a block of cyclic control of commutation. The controlling outlets of it are connected to the controllable inlets of the commutators and the inlet of the remote measurement system for transmission of information to the surface.

  14. Electromagnetic Environmental Effects System Testing

    Science.gov (United States)

    2013-11-20

    K-1 L. INTRA SYSTEM ELECTROMAGNETIC COMPATIBILITY ( EMC ) SOURCE/VICTIM ................... L-1 M. PERSONNEL...TEMPEST and test guidance for the addition of test procedures for implementing Electromagnetic Compatibility ( EMC ), Radiated Emissions (RE...for Grounds and Bonds is not addressed since it is sufficiently discussed in MIL-STD-464C. For Shielding Effectiveness, reference American Society

  15. Exploration of the Electromagnetic Environment

    Science.gov (United States)

    Fullekrug, M.

    2009-01-01

    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…

  16. Electromagnetic actuation in MEMS switches

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de; Mátéfi-Tempfli, Mária; Chemnitz, Steffen

    . Electromagnetic actuation is a very promising approach to operate such MEMS and Power MEMS devices, due to the long range, reproducible and strong forces generated by this method, among other advantages. However, the use of electromagnetic actuation in such devices requires the use of thick magnetic films, which...

  17. Electromagnetic compatibility in power electronics

    CERN Document Server

    Costa , François; Revol , Bertrand

    2014-01-01

    Scientists largely attribute the recent deterioration of the electromagnetic environment to power electronics. This realization has spurred the study of methodical approaches to electromagnetic compatibility designs as explored in this text. The book addresses major challenges, such as handling numerous parameters vital to predicting electro magnetic effects and achieving compliance with line-harmonics norms, while proposing potential solutions.

  18. EM Induction Experiment to Determine the Moment of a Magnet

    Science.gov (United States)

    Najiya Maryam, K. M.

    2014-01-01

    If we drop a magnet through a coil, an emf is induced in the coil according to Faraday's law of electromagnetic induction. Here, such an experiment is done using expEYES kit. The plot of emf versus time has a specific shape with two peaks. A theoretical analysis of this graph is discussed here for both short and long cylindrical magnets.…

  19. Recent simulation results of the magnetic induction tomography forward problem

    Directory of Open Access Journals (Sweden)

    Stawicki Krzysztof

    2016-06-01

    Full Text Available In this paper we present the results of simulations of the Magnetic Induction Tomography (MIT forward problem. Two complementary calculation techniques have been implemented and coupled, namely: the finite element method (applied in commercial software Comsol Multiphysics and the second, algebraic manipulations on basic relationships of electromagnetism in Matlab. The developed combination saves a lot of time and makes a better use of the available computer resources.

  20. Monitoring scale-specific and temporal variation in electromagnetic conductivity images

    Science.gov (United States)

    In the semi-arid and arid landscapes of southwest USA, irrigation sustains agricultural activity; however, there are increasing demands on water resources. As such spatial temporal variation of soil moisture needs to be monitored. One way to do this is to use electromagnetic (EM) induction instrumen...

  1. Time-lapse monitoring of soil water content using electromagnetic conductivity imaging

    Science.gov (United States)

    The volumetric soil water content (VWC) is fundamental to agriculture. Unfortunately, the universally accepted thermogravimetric method is labour intensive and time-consuming to use for field-scale monitoring. Electromagnetic (EM) induction instruments have proven to be useful in mapping the spatio-...

  2. Electromagnetic Interference (EMI) and TEMPEST Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Electromagnetic Interference (EMI), Electromagnetic Compatibility (EMC) and TEMPEST testing are conducted at EPG's Blacktail Canyon Test Facility in one of its two...

  3. Radiofrequency Electromagnetic Field Map of Timisoara

    National Research Council Canada - National Science Library

    N. Stefu; I. Solyom; A. Arama

    2015-01-01

    There are many electromagnetic field (EMF) sources nowadays acting simultaneously, especially in urban areas, making the theoretical estimation of electromagnetic power at ground level very difficult...

  4. Cryogenic pulsed inductive microwave magnetometer

    Science.gov (United States)

    Kos, A. B.; Nibarger, J. P.; Lopusnik, R.; Silva, T. J.; Celinski, Z.

    2003-05-01

    A cryogenic pulsed inductive microwave magnetometer is used to characterize the switching dynamics in thin-film magnetic materials at low temperatures and microwave frequencies. The system is contained inside a 20-cm-diam ultrahigh vacuum chamber and cooled by a cryopump that allows measurements between 20 and 350 K. A temperature controller regulates the sample temperature using two silicon diodes as sensors. Applied magnetic fields of up to 36 kA/m (450 Oe) are generated by a four-pole, water-cooled electromagnet with independent control of each axis. Magnetic switching in the sample is driven by high-speed current step pulses in a coplanar waveguide structure with the sample placed in a flip-chip configuration. A 20 GHz sampling oscilloscope is used to record the dynamics of the magnetic reorientation. The switching dynamics are given for a 10-nm-thick Ni-Fe film at 30 K in response to a 1 kA/m field step.

  5. CONSIDERATIONS ON ELECTROMAGNETIC HUMIDITY MEASUREMENT IN SIMPLE MASONRY WALLS

    Directory of Open Access Journals (Sweden)

    Tudor BURLAN-ROTAR

    2016-05-01

    Full Text Available Humidity measurement in thick walls indicate under what conditions is exploited a building. Any type of moisture walls, superficial or deep, give information about possible cracks or infiltration of water. The electromagnetic techniques for measuring soil humidity (by resistivity has been known for a long time. It can be used to measure walls moisture. Conductivity is preferable in inductive techniques, as instrumentation readings are generally directly proportional to conductivity and inversely proportional to resistivity. The operating principle of this method is: a Tx coil transmitter, supplied with alternatingcurrent at an audio frequency, is placed on the wall. An Rx coil receiver is located at a short distance, s, (on the wall away from the Tx coil. The magnetic field varies in time and the Tx coil induces very small currents in the wall. These currents generate a secondary magnetic field, Hs, which is sensed by the Rx receiver coil, together, with primary magnetic field Hp. The ratio of the secondary field, Hs, to the primary magnetic field, Hp, (Hs/Hp is directly proportional to wall conductivity. Measuring this ratio, it is possible to construct a device which measures the wall conductivity by contactless, direct-reading electromagnetic technique (linear meter. This technique for measuring conductivity by electromagnetic induction, using Very Low Frequency (VLF, is a non-intrusive, non-destructive sampling method. The measurements can be done quickly and are not expensive.

  6. Gravitational scattering of electromagnetic radiation

    Science.gov (United States)

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

    1980-01-01

    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.

  7. Electromagnetic containerless processing requirements and recommended facility concept and capabilities for space lab

    Science.gov (United States)

    Frost, R. T.; Bloom, H. L.; Napaluch, L. J.; Stockhoff, E. H.; Wouch, G.

    1974-01-01

    Containerless melting, reaction, and solidification experiments and processes which potentially can lead to new understanding of material science and production of new or improved materials in the weightless space environment are reviewed in terms of planning for spacelab. Most of the experiments and processes discussed are amenable to the employment of electromagnetic position control and electromagnetic induction or electron beam heating and melting. The spectrum of relevant properties of materials, which determine requirements for a space laboratory electromagnetic containerless processing facility are reviewed. Appropriate distributions and associated coil structures are analyzed and compared on the basis of efficiency, for providing the functions of position sensing, control, and induction heating. Several coil systems are found capable of providing these functions. Exchangeable modular coils in appropriate sizes are recommended to achieve the maximum power efficiencies, for a wide range of specimen sizes and resistivities, in order to conserve total facility power.

  8. Numerical investigation of melting and solidification processes in modified surface layers of metal at induction heating

    Science.gov (United States)

    Shchukin, V. G.; Popov, V. N.

    2017-10-01

    One of the perspective ways to improve the operational properties of parts of machines during induction treatment of their surfaces is the modification of the melt by specially prepared nanoscale particles of refractory compounds (carbides, nitrides, carbonitrides, etc.). This approach allows us to increase the number of crystallization centers and to refine the structural components of the solidified metal. The resulting high dispersity and homogeneity of crystalline grains favorably affect the quality of the treated surfaces. 3D numerical simulation of thermophysical processes in the modification of the surface layer of metal in a moving substrate was carried out. It is assumed that the surface of the substrate is covered with a layer of specially prepared nanoscale particles of a refractory compound, which, upon penetration into the melt, are uniformly distributed in it. The possibility of applying a high-frequency electromagnetic field of high power for heating and melting of a metal (iron) for the purpose of its subsequent modification is investigated. The distribution of electromagnetic energy in the metal is described by empirical formulas. Melting of the metal is considered in the Stefan approximation, and upon solidification it is assumed that all nanoparticles serve as centers for volume-sequential crystallization. Calculations were carried out with the following parameters: specific power p0 = 35 and 40 kW/cm2 at frequency f = 440 and 1200 kHz, the substrate velocity V = 0.5-2.5 cm/s, the nanoparticles' size is 50 nm and concentration Np = 2.0 . 109 cm-3. Based on the results obtained in a quasi-stationary formulation, the distribution of the temperature field, the dimensions of the melting and crystallization zones, the change in the solid fraction in the two-phase zone, the area of the treated substrate surface, depending on the speed of its movement and induction heating characteristics were estimated.

  9. Induction Therapy for Mesothelioma.

    Science.gov (United States)

    Opitz, Isabelle; Weder, Walter

    2015-01-01

    One particular approach of multimodality treatment for mesothelioma is induction therapy followed by surgery. Among its several advantages, the most important is downstaging of the tumor into a resectable stage, although morbidity and mortality might be increased. In this article we review the principles and outcome of different modalities for induction treatment of mesothelioma. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Design and analysis of electromagnetic interference filters and shields

    Science.gov (United States)

    McDowell, Andrew Joel

    Electromagnetic interference (EMI) is a problem of rising prevalence as electronic devices become increasingly ubiquitous. EMI filters are low pass filters intended to prevent the conducted electric currents and radiated electromagnetic fields of a device from interfering with the proper operation of other devices. Shielding is a method, often complementary to filtering, that typically involves enclosing a device in a conducting box in order to prevent radiated EMI. This dissertation includes three chapters related to the use of filtering and shielding for preventing electromagnetic interference. The first chapter deals with improving the high frequency EMI filtering performance of surface mount capacitors on printed circuit boards (PCBs). At high frequencies, the impedance of a capacitor is dominated by a parasitic inductance, thus leading to poor high frequency filtering performance. Other researchers have introduced the concept of parasitic inductance cancellation and have applied this concept to improving the filtering performance of volumetrically large capacitors at frequencies up to 100 MHz. The work in this chapter applies the concept of parasitic inductance cancellation to much smaller surface mount capacitors at frequencies up to several gigahertz. The second chapter introduces a much more compact design for applying parasitic inductance cancellation to surface mount capacitors that uses inductive coupling between via pairs as well as coplanar traces. This new design is suited for PCBs having three or more layers including solid ground and/or power plane(s). This design is demonstrated to be considerably more effective in filtering high frequency noise due to crosstalk than a comparable conventional shunt capacitor filter configuration. Finally, chapter 3 presents a detailed analysis of the methods that are used to decompose the measure of plane wave shielding effectiveness into measures of absorption and reflection. Textbooks on electromagnetic

  11. Progress in Induction Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Caporaso, G J

    2000-09-27

    This presentation will be a broad survey of progress in induction technology over the past four years. Much work has been done on accelerators for hydrodynamic test radiography and other applications. Solid-state pulsers have been developed which can provide unprecedented flexibility and precision in pulse format and accelerating voltage for both ion and electron induction machines. Induction linacs can now be built which can operate with MHz repetition rates. Solid-state technology has also made possible the development of fast kickers for precision control of high current beams. New insulator technology has been developed which will improve conventional induction linacs in addition to enabling a new class of high gradient induction linacs.

  12. Study on the adjustment capability of the excitation system located inside superconducting machine electromagnetic shield

    Science.gov (United States)

    Xia, D.; Xia, Z.

    2017-12-01

    The ability for the excitation system to adjust quickly plays a very important role in maintaining the normal operation of superconducting machines and power systems. However, the eddy currents in the electromagnetic shield of superconducting machines hinder the exciting magnetic field change and weaken the adjustment capability of the excitation system. To analyze this problem, a finite element calculation model for the transient electromagnetic field with moving parts is established. The effects of three different electromagnetic shields on the exciting magnetic field are analyzed using finite element method. The results show that the electromagnetic shield hinders the field changes significantly, the better its conductivity, the greater the effect on the superconducting machine excitation.

  13. Electromagnetic field generated by a charge moving along a helical orbit inside a dielectric cylinder

    OpenAIRE

    Saharian, A. A.; Kotanjyan, A.S.; Grigoryan, M. L.

    2006-01-01

    The electromagnetic field generated by a charged particle moving along a helical orbit inside a dielectric cylinder immersed into a homogeneous medium is investigated. Expressions are derived for the electromagnetic potentials, electric and magnetic fields in the region inside the cylinder. The parts corresponding to the radiation field are separated. The radiation intensity on the lowest azimuthal mode is studied.

  14. Agile Production of Sheet Metal Aviation Components Using Disposable Electromagnetic Actuators

    OpenAIRE

    CARSON, B.; Daehn, G.; Psyk, V.; Tekkaya, A.E.; Weddeling, C.; Woodward, S.

    2010-01-01

    Electromagnetic forming is a process used to produce high strain rates that improve the formability of sheet metal. The objective of this paper is to discuss the feasibility of the use of disposable actuators during electromagnetic forming of two aluminum components: an industry part whose main feature is a convex flange with two joggles, and a simple part with a one-dimensional curve throughout. The main forming complications after the parts were formed using conventional methods were the pr...

  15. Anomalous electromagnetic coupling via entanglement at the nanoscale

    Science.gov (United States)

    Slepyan, Gregory; Boag, Amir; Mordachev, Vladimir; Sinkevich, Eugene; Maksimenko, Sergey; Kuzhir, Polina; Miano, Giovanni; Portnoi, Mikhail E.; Maffucci, Antonio

    2017-02-01

    Understanding unwanted mutual interactions between devices at the nanoscale is crucial for the study of the electromagnetic compatibility in nanoelectronic and nanophotonic systems. Anomalous electromagnetic coupling (crosstalk) between nanodevices may arise from the combination of electromagnetic interaction and quantum entanglement. In this paper we study in detail the crosstalk between two identical nanodevices, each consisting of a quantum emitter (atom, quantum dot, etc), capacitively coupled to a pair of nanoelectrodes. Using the generalized susceptibility concept, the overall system is modeled as a two-port within the framework of the electrical circuit theory and it is characterized by the admittance matrix. We show that the entanglement changes dramatically the physical picture of the electromagnetic crosstalk. In particular, the excitation produced in one of the ports may be redistributed in equal parts between both the ports, in spite of the rather small electromagnetic interactions. Such an anomalous crosstalk is expected to appear at optical frequencies in lateral GaAs double quantum dots. A possible experimental set up is also discussed. The classical concepts of interference in the operation of electronic devices, which have been known since the early days of radio-communications and are associated with electromagnetic compatibility, should then be reconsidered at the nanoscale.

  16. Split Octonion Reformulation for Electromagnetic Chiral Media of Massive Dyons

    Science.gov (United States)

    Chanyal, B. C.

    2017-12-01

    In an explicit, unified, and covariant formulation of an octonion algebra, we study and generalize the electromagnetic chiral fields equations of massive dyons with the split octonionic representation. Starting with 2×2 Zorn’s vector matrix realization of split-octonion and its dual Euclidean spaces, we represent the unified structure of split octonionic electric and magnetic induction vectors for chiral media. As such, in present paper, we describe the chiral parameter and pairing constants in terms of split octonionic matrix representation of Drude-Born-Fedorov constitutive relations. We have expressed a split octonionic electromagnetic field vector for chiral media, which exhibits the unified field structure of electric and magnetic chiral fields of dyons. The beauty of split octonionic representation of Zorn vector matrix realization is that, the every scalar and vector components have its own meaning in the generalized chiral electromagnetism of dyons. Correspondingly, we obtained the alternative form of generalized Proca–Maxwell’s equations of massive dyons in chiral media. Furthermore, the continuity equations, Poynting theorem and wave propagation for generalized electromagnetic fields of chiral media of massive dyons are established by split octonionic form of Zorn vector matrix algebra.

  17. Electromagnetic fields and life

    CERN Document Server

    Presman, A S

    1970-01-01

    A broad region of the electromagnetic spectrum long assumed to have no influence on living systems under natural conditions has been critically re-examined over the past decade. This spectral region extends from the superhigh radio frequencies, through de­ creasing frequencies, to and including essentially static electric and magnetic fields. The author of this monograph, A. S. Presman, has reviewed not only the extensive Russian literatur!;"l, but also al­l most equally comprehensively the non-Russian literature, dealing with biological influences of these fields. Treated also is literature shedding some light on possible theoretical foundations for these phenomena. A substantial, rapidly increasing number of studies in many laboratories and countries has now clearly established bio­ logical influences which are independent of the theoretically predictable, simple thermal effects. Indeed many of the effects are produced by field strengths very close to those within the natural environment. The author has,...

  18. Electromagnetically Clean Solar Arrays

    Science.gov (United States)

    Stem, Theodore G.; Kenniston, Anthony E.

    2008-01-01

    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

  19. Electromagnetic scattering theory

    Science.gov (United States)

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

    1986-01-01

    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.

  20. Focusing of electromagnetic waves

    Energy Technology Data Exchange (ETDEWEB)

    Dhayalan, V.

    1996-12-31

    The focusing of electromagnetic waves inside a slab has been examined together with two special cases in which the slab is reduced to a single interface or a single medium. To that end the exact solutions for the fields inside a layered medium have been used, given in terms of the outside current source in order to obtain the solutions for the focused electric field inside a slab. Both exact and asymptotic solutions of the problem have been considered, and the validity of the latter has been discussed. The author has developed a numerical algorithm for evaluation of the diffraction integral with special emphasis on reducing the computing time. The numerical techniques in the paper can be readily applied to evaluate similar diffraction integrals occurring e.g. in microstrip antennas. 46 refs.

  1. Solved problems in electromagnetics

    CERN Document Server

    Salazar Bloise, Félix; Bayón Rojo, Ana; Gascón Latasa, Francisco

    2017-01-01

    This book presents the fundamental concepts of electromagnetism through problems with a brief theoretical introduction at the beginning of each chapter. The present book has a strong  didactic character. It explains all the mathematical steps and the theoretical concepts connected with the development of the problem. It guides the reader to understand the employed procedures to learn to solve the exercises independently. The exercises are structured in a similar way: The chapters begin with easy problems increasing progressively in the level of difficulty. This book is written for students of physics and engineering in the framework of the new European Plans of Study for Bachelor and Master and also for tutors and lecturers. .

  2. On steady electromagnetic equilibria

    Science.gov (United States)

    Lehnert, B.

    1986-12-01

    The existence of steady electromagnetic equilibrium states predicted by an extended Lorentz invariant formulation of Maxwell's equations is analyzed. General equilibrium solutions are outlined which lead to integrated field quantities of the system, such as total charge qo, magnetic moment Mo, mass mo and angular momentum so. The quantization of moMo/qo in terms of Bohr magnetons is shown to be equivalent to the proposed resonance condition of circulating self-confined radiation. Exact equilibrium solutions were deduced in two simple cases, thereby leading to a so of the same order as that of the electron, and to a qo one order of magnitude larger than the electronic charge. A variational procedure is suggested in search for states of minimum charge, under the subsidiary quantum conditions on moMo/qo and so, i.e., by varying the profile of the electric space charge distribution.

  3. Nucleon Electromagnetic Form Factors

    Energy Technology Data Exchange (ETDEWEB)

    Marc Vanderhaeghen; Charles Perdrisat; Vina Punjabi

    2007-10-01

    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.

  4. Electromagnetic properties of neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Ould-Saada, F. [Zurich Univ. (Switzerland). Inst. fuer Physik

    1996-11-01

    Electromagnetic properties of neutrinos and their implications are discussed, and the experimental situation summarised. Spin precession in solar magnetic fields presents a solution of the solar neutrino problem. A magnetic moment, {mu}{sub {nu}}, of the order of 10{sup -11} {mu}{sub B} would be needed. In the simplest extension of the standard model, with no-vanishing neutrino masses, dipole moment interactions are allowed through higher order processes. A neutrino mass of {approx_equal}10 eV would give {mu}{sub {nu}}{approx_equal}10{sup -18} {mu}{sub B}, much smaller than the present experimental upper limit of 2x10{sup -10} {mu}{sub B}. Although model-dependent, upper bounds on dipole moments from astrophysics and cosmology are 10 to 100 times more stringent. Any values of {mu}{sub {nu}}, larger than the SM predictions, would then signal the onset of new physics. Among the processes sensitive to the magnetic moment, {nu}e{sup -} scattering presents two advantages: it is a pure weak, theoretically well understood process, and the recoil electron can be easily measured. A hypothetical electromagnetic contribution to the cross-section would dominate at low energies. A low background detector, MUNU, being built at the Bugey nuclear reactor is presented.It is based on a gas TPC, surrounded by a scintillator. The threshold on the electron recoil energy can be set very low, around 500 keV, giving the experiment a good sensitivity to the magnetic moment of the {nu}{sub e}, extending down to 2x10{sup -11} {mu}{sub B}. (author) 15 figs., 5 tabs., 96 refs.

  5. KEKB electromagnet power supply

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Masato; Kubo, Tadashi [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan)

    2000-01-01

    Numbers of electromagnet power supply for KEKB are 2,243 except BT. To satisfy stability, DAC in the current control circuit, current detector, R and D of small thermostatic bath and a calibration method of current using CPU were introduced. They satisfied needs. With producing R and D apparatus of switching source, problems of ripple, stability and noise were solved, so that we began mass production. In this paper, many kinds of R and D and performance and troubles after operation of KEKB power source are described. A plan of design of power supply consisted of seven items such as high accuracy, serial communication of interface, small type, high affectivity, easy maintenance, independence of current setting and current detector for monitor and control of radiation and conduction noise of switching power supply. These items were satisfied by development of interface board of ARCNET communication, introduction of double buffer method for interface through CPU, power supply unit by air-cooled method using a switching method and small thermostatic oven for bending and quadrupole electromagnet. R and D of DCCT, burden and shunt resistance, DAC, thermostatic bath, power supply, offset and gain calibration by double buffer method, specification of power supply, various kinds of measurements of mass production apparatus at rising, after long operation and problems before and after operation are reported. The results of R and D made satisfy the specification of stability and ripple of power supply. Although many switching power supply were operated, there was no noise and troubles at the initial period decreased. However, in order to use many power supply, the performance measurement and maintenance are very important at long shut down. (S.Y.)

  6. Magnetic flux distribution in a ferromagnetic material magnetized by U-shaped electromagnets of different geometric dimensions types

    Directory of Open Access Journals (Sweden)

    Povolotskaya Anna

    2018-01-01

    Full Text Available A model experiment has been carried out on studying the type of changes in the magnetic induction in a homogeneous isotropic sample that is locally magnetized with attached U-type electromagnets of different geometrical dimensions. The study was aimed at finding out magnetic flux distribution at different locations within the sample and determining the effect that the geometry of attached electromagnets has on this distribution.

  7. Numerical analysis of high strain rate failure of electro-magnetically loaded steel sheets

    Directory of Open Access Journals (Sweden)

    Erice Borja

    2015-01-01

    Full Text Available Electro-magnetic forces provide a potentially power full means in designing dynamic experiments with active control of the loading conditions. This article deals with the development of computational models to simulate the thermo-mechanical response of electro-magnetically loaded metallic structures. The model assumes linear electromagnetic constitutive equations and time-independent electric induction to estimate the Joule heating and the Lorentz forces. The latter are then taken into account when evaluating stress equilibrium. A thermo-visco-plastic model with Johnson-Cook type of temperature and strain rate dependence and combined Swift-Voce hardening is used to evaluate the material's thermo-mechanical response. As a first application, the model is used to analyse the effect of electro-magnetic loading on the ductility of advanced high strength steels.

  8. Coupling capacitor voltage transformer: A model for electromagnetic transient studies

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, D.; Neves, W.L.A. [Department of Electrical Engineering, Federal University of Campina Grande, Av. Aprigio Veloso, 882 Bodocongo, 58.109-970 Campina Grande, PB (Brazil); Vasconcelos, J.C.A. [Companhia Hidro Eletrica do Sao Francisco, Rua Delmiro Gouveia, 333 Bongi, 50.761-901 Recife, PE (Brazil)

    2007-02-15

    In this work, an accurate coupling capacitor voltage transformer (CCVT) model for electromagnetic transient studies is presented. The model takes into account linear and nonlinear elements. A support routine was developed to compute the linear 230kV CCVT parameters (resistances, inductances and capacitances) from frequency response data. The magnetic core and surge arrester nonlinear characteristics were estimated from laboratory measurements as well. The model is used in connection with the electromagnetic transients program (EMTP) to predict the CCVT performance when it is submitted to transient overvoltages, as are the cases of voltages due to the ferroresonance phenomenon and circuit breaker switching. The difference between simulated and measured results is fairly small. Simulations had shown that transient overvoltages produced inside the CCVT, when a short circuit is cleared at the CCVT secondary side, are effectively damped out by the ferroresonance suppression circuit and the protection circuit. (author)

  9. Electromagnetic environment and telecommunications: towards a cognitive electromagnetic compatibility

    Science.gov (United States)

    Zeddam, Ahmed; Avril, Gautier; Tlich, Mohamed

    2009-01-01

    This article deals with the electromagnetic environment management problem within the context of high speed digital transmissions deployed in wired telecommunication networks. Traditionally, Electromagnetic Compatibility (EMC) is assured by filtering for better electromagnetic immunity, and by cable shielding for emission limitation. However, like cognitive radio, we can also, for high speed wired transmissions, treat the EMC as an intelligent and autonomous system capable of perceiving its environment, interpreting it, making suited decisions, and reacting according to the constraints related to the electromagnetic environment. In this context, some application examples are here given in order to illustrate this evolution towards a cognitive EMC in wired networks. To cite this article: A. Zeddam et al., C. R. Physique 10 (2009).

  10. Effect of Inductive Coil Geometry and Current Sheet Trajectory of a Conical Theta Pinch Pulsed Inductive Plasma Accelerator

    Science.gov (United States)

    Hallock, Ashley K.; Polzin, Kurt A.; Bonds, Kevin W.; Emsellem, Gregory D.

    2011-01-01

    Results are presented demonstrating the e ect of inductive coil geometry and current sheet trajectory on the exhaust velocity of propellant in conical theta pinch pulsed induc- tive plasma accelerators. The electromagnetic coupling between the inductive coil of the accelerator and a plasma current sheet is simulated, substituting a conical copper frustum for the plasma. The variation of system inductance as a function of plasma position is obtained by displacing the simulated current sheet from the coil while measuring the total inductance of the coil. Four coils of differing geometries were employed, and the total inductance of each coil was measured as a function of the axial displacement of two sep- arate copper frusta both having the same cone angle and length as the coil but with one compressed to a smaller size relative to the coil. The measured relationship between total coil inductance and current sheet position closes a dynamical circuit model that is used to calculate the resulting current sheet velocity for various coil and current sheet con gura- tions. The results of this model, which neglects the pinching contribution to thrust, radial propellant con nement, and plume divergence, indicate that in a conical theta pinch ge- ometry current sheet pinching is detrimental to thruster performance, reducing the kinetic energy of the exhausting propellant by up to 50% (at the upper bound for the parameter range of the study). The decrease in exhaust velocity was larger for coils and simulated current sheets of smaller half cone angles. An upper bound for the pinching contribution to thrust is estimated for typical operating parameters. Measurements of coil inductance for three di erent current sheet pinching conditions are used to estimate the magnetic pressure as a function of current sheet radial compression. The gas-dynamic contribution to axial acceleration is also estimated and shown to not compensate for the decrease in axial electromagnetic acceleration

  11. Differential forms on electromagnetic networks

    CERN Document Server

    Balasubramanian, N V; Sen Gupta, D P

    2013-01-01

    Differential Forms on Electromagnetic Networks deals with the use of combinatorial techniques in electrical circuit, machine analysis, and the relationship between circuit quantities and electromagnetic fields. The monograph is also an introduction to the organization of field equations by the methods of differential forms. The book covers topics such as algebraic structural relations in an electric circuit; mesh and node-pair analysis; exterior differential structures; generalized Stoke's theorem and tensor analysis; and Maxwell's electromagnetic equation. Also covered in the book are the app

  12. Electromagnetic transients in power cables

    CERN Document Server

    da Silva, Filipe Faria

    2013-01-01

    From the more basic concepts to the most advanced ones where long and laborious simulation models are required, Electromagnetic Transients in Power Cables provides a thorough insight into the study of electromagnetic transients and underground power cables. Explanations and demonstrations of different electromagnetic transient phenomena are provided, from simple lumped-parameter circuits to complex cable-based high voltage networks, as well as instructions on how to model the cables.Supported throughout by illustrations, circuit diagrams and simulation results, each chapter contains exercises,

  13. Electromagnetic foundations of electrical engineering

    CERN Document Server

    Faria, J A Brandao

    2008-01-01

    The applications of electromagnetic phenomena within electrical engineering have been evolving and progressing at a fast pace. In contrast, the underlying principles have been stable for a long time and are not expected to undergo any changes. It is these electromagnetic field fundamentals that are the subject of discussion in this book with an emphasis on basic principles, concepts and governing laws that apply across the electrical engineering discipline. Electromagnetic Foundations of Electrical Engineering begins with an explanation of Maxwell's equations, from which the fundament

  14. A primer on electromagnetic fields

    CERN Document Server

    Frezza, Fabrizio

    2015-01-01

    This book is a concise introduction to electromagnetics and electromagnetic fields that covers the aspects of most significance for engineering applications by means of a rigorous, analytical treatment. After an introduction to equations and basic theorems, topics of fundamental theoretical and applicative importance, including plane waves, transmission lines, waveguides, and Green's functions, are discussed in a deliberately general way. Care has been taken to ensure that the text is readily accessible and self-consistent, with conservation of the intermediate steps in the analytical derivations. The book offers the reader a clear, succinct course in basic electromagnetic theory. It will also be a useful lookup tool for students and designers.

  15. Field models and numerical dosimetry inside an extremely-low-frequency electromagnetic bioreactor: the theoretical link between the electromagnetically induced mechanical forces and the biological mechanisms of the cell tensegrity.

    Science.gov (United States)

    Mognaschi, Maria Evelina; Di Barba, Paolo; Magenes, Giovanni; Lenzi, Andrea; Naro, Fabio; Fassina, Lorenzo

    2014-01-01

    We have implemented field models and performed a detailed numerical dosimetry inside our extremely-low-frequency electromagnetic bioreactor which has been successfully used in in vitro Biotechnology and Tissue Engineering researches. The numerical dosimetry permitted to map the magnetic induction field (maximum module equal to about 3.3 mT) and to discuss its biological effects in terms of induced electric currents and induced mechanical forces (compression and traction). So, in the frame of the tensegrity-mechanotransduction theory of Ingber, the study of these electromagnetically induced mechanical forces could be, in our opinion, a powerful tool to understand some effects of the electromagnetic stimulation whose mechanisms remain still elusive.

  16. [Electromagnetic pollution (electrosmog)--potential hazards of our electromagnetic future].

    Science.gov (United States)

    Nowak, D; Radon, K

    2004-02-26

    The term electromagnetic environment encompasses the totality of all electric, magnetic and electromagnetic fields generated by natural and technical sources. A differentiation is made between low- and high-frequency electromagnetic fields. Typical sources of the former are domestic electricity Exposure to the latter is, for example, associated with the sue of mobile telephones. Studies on the health-related effects of electromagnetic fields are available in particular for the low-frequency range, based on an appropriate estimation of exposure. A number of these studies reveal an association between exposure to this type of electromagnetic fields and the occurrence of infantile leukemia in the highest exposure category. For high-frequency electromagnetic fields the number of epidemiological studies is limited. An increased risk of an accident occurring through the use of a cellular phone while driving has consistently been shown. Against the background of our limited knowledge about possible adverse effects of exposure to mobile phone transmitters, and the inability of the public to influence such exposure, transparency in the communication of the risks involved is of great importance.

  17. Gallilei covariant quantum mechanics in electromagnetic fields

    Directory of Open Access Journals (Sweden)

    H. E. Wilhelm

    1985-01-01

    Full Text Available A formulation of the quantum mechanics of charged particles in time-dependent electromagnetic fields is presented, in which both the Schroedinger equation and wave equations for the electromagnetic potentials are Galilei covariant, it is shown that the Galilean relativity principle leads to the introduction of the electromagnetic substratum in which the matter and electromagnetic waves propagate. The electromagnetic substratum effects are quantitatively significant for quantum mechanics in reference frames, in which the substratum velocity w is in magnitude comparable with the velocity of light c. The electromagnetic substratum velocity w occurs explicitly in the wave equations for the electromagnetic potentials but not in the Schroedinger equation.

  18. A novel induction motor starting method using superconduction

    Science.gov (United States)

    Silva, F. B. B.; Orlando, M. T. D.; Fardin, J. F.; Simonetti, D. S.; Baldan, C. A.

    2014-12-01

    In this paper, an alternative method for starting up induction motors is proposed, taking into account experimental measurements. The new starting current limitation method is based on using a high-temperature superconductor. A prototype of the superconducting starting current limiter was constructed with a commercially available second-generation high-temperature superconductor YBCO tape, and this was tested with a 55-kW industrial induction motor in a 440-V/60-Hz three-phase power grid. Performance evaluations of the superconducting limiter method (applied to startup of the induction motor) were performed and were compared with a direct-on-line starter and an electronic soft starter. In addition, a computational model was developed and used for electromagnetic torque analysis of the system. As significant characteristics, our method offers the ability to limit the starting current of the induction motor with greater electromagnetic torque, reduced current waveform distortion and therefore lower harmonic pollution during startup when compared to the soft starter method.

  19. Unfolding the procedure of characterizing recorded ultra low frequency, kHZ and MHz electromagnetic anomalies prior to the L'Aquila earthquake as pre-seismic ones - Part 2

    Directory of Open Access Journals (Sweden)

    K. Eftaxias

    2010-02-01

    Full Text Available Ultra low frequency-ULF (1 Hz or lower, kHz and MHz electromagnetic (EM anomalies were recorded prior to the L'Aquila catastrophic earthquake (EQ that occurred on 6 April 2009. The detected anomalies followed this temporal scheme. (i The MHz EM anomalies were detected on 26 March 2009 and 2 April 2009. The kHz EM anomalies were emerged on 4 April 2009. The ULF EM anomaly was appeared from 29 March 2009 up to 3 April 2009. The question effortlessly arises as to whether the observed anomalies before the L'Aquila EQ were seismogenic or not. The main goal of this work is to provide some insight into this issue. More precisely, the main aims of this contribution are threefold: How can we recognize an EM observation as pre-seismic one? We aim, through a multidisciplinary analysis to provide some elements of a definition. How can we link an individual EM anomaly with a distinctive stage of the EQ preparation process? The present analysis is consistent with the hypothesis that the kHz EM anomalies were associated with the fracture of asperities that were distributed along the L'Aquila fault sustaining the system, while the MHz EM anomalies could be triggered by fractures in the highly disordered system that surrounded the backbone of asperities of the activated fault. How can we identify precursory symptoms in an individual EM precursor that indicate that the occurrence of the EQ is unavoidable? We clearly state that the detection of a MHz EM precursor does not mean that the occurrence of EQ is unavoidable; the abrupt emergence of kHz EM emissions indicate the fracture of asperities. The observed ULF EM anomaly supports the hypothesis of a relationship between processes produced by increasing tectonic stresses in the Earth's crust and attendant EM interactions between the crust and ionosphere. We emphasize that we attempt to specify not only whether or not a single EM anomaly is pre-seismic in itself, but mainly whether a combination of emergent ULF

  20. Interaction of electromagnetic radiation in the 20-200 GHz frequency range with arrays of carbon nanotubes with ferromagnetic nanoparticles.

    Science.gov (United States)

    Atdayev, Agylych; Danilyuk, Alexander L; Prischepa, Serghej L

    2015-01-01

    The interaction of electromagnetic radiation with a magnetic nanocomposite based on carbon nanotubes (CNT) is considered within the model of distributed random nanoparticles with a core-shell morphology. The approach is based on a system composed of a CNT conducting resistive matrix, ferromagnetic inductive nanoparticles and the capacitive interface between the CNT matrix and the nanoparticles, which form resonance resistive-inductive-capacitive circuits. It is shown that the influence of the resonant circuits leads to the emergence of specific resonances, namely peaks and valleys in the frequency dependence of the permeability of the nanocomposite, and in the frequency dependence of the reflection and transmission of electromagnetic radiation.

  1. Induction melter apparatus

    Science.gov (United States)

    Roach, Jay A [Idaho Falls, ID; Richardson, John G [Idaho Falls, ID; Raivo, Brian D [Idaho Falls, ID; Soelberg, Nicholas R [Idaho Falls, ID

    2008-06-17

    Apparatus and methods of operation are provided for a cold-crucible-induction melter for vitrifying waste wherein a single induction power supply may be used to effect a selected thermal distribution by independently energizing at least two inductors. Also, a bottom drain assembly may be heated by an inductor and may include an electrically resistive heater. The bottom drain assembly may be cooled to solidify molten material passing therethrough to prevent discharge of molten material therefrom. Configurations are provided wherein the induction flux skin depth substantially corresponds with the central longitudinal axis of the crucible. Further, the drain tube may be positioned within the induction flux skin depth in relation to material within the crucible or may be substantially aligned with a direction of flow of molten material within the crucible. An improved head design including four shells forming thermal radiation shields and at least two gas-cooled plenums is also disclosed.

  2. Thermal kinetic inductance detector

    Science.gov (United States)

    Cecil, Thomas; Gades, Lisa; Miceli, Antonio; Quaranta, Orlando

    2016-12-20

    A microcalorimeter for radiation detection that uses superconducting kinetic inductance resonators as the thermometers. The detector is frequency-multiplexed which enables detector systems with a large number of pixels.

  3. An Apparatus for Constructing an Electromagnetic Plane Wave Model

    Science.gov (United States)

    Kneubil, Fabiana Botelho; Loures, Marcus Vinicius Russo; Amado, William

    2015-01-01

    In this paper we report on an activity aimed at building an electromagnetic wave. This was part of a class on the concept of mass offered to a group of 20 pre-service Brazilian physics teachers. The activity consisted of building a plane wave using an apparatus in which it is possible to fit some rods representing electric and magnetic fields into…

  4. What can we Learn from the Electromagnetic Spectrum?

    Indian Academy of Sciences (India)

    Ultraviolet rays. Visible light. Infrared rays. Microwaves. Radio waves. Table 1. The spectrum of electromagnetic radiation, with its seven main parts and their .... Thus plants reflect. EM radiation in the range of 500 to 600 nm. This wavelength region falls in green colour. No wonder the tree leaves mostly appear green when ...

  5. Conical electromagnetic radiation flux concentrator

    Science.gov (United States)

    Miller, E. R.

    1972-01-01

    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.

  6. Earthquake prediction with electromagnetic phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Masashi, E-mail: hayakawa@hi-seismo-em.jp [Hayakawa Institute of Seismo Electomagnetics, Co. Ltd., University of Electro-Communications (UEC) Incubation Center, 1-5-1 Chofugaoka, Chofu Tokyo, 182-8585 (Japan); Advanced Wireless & Communications Research Center, UEC, Chofu Tokyo (Japan); Earthquake Analysis Laboratory, Information Systems Inc., 4-8-15, Minami-aoyama, Minato-ku, Tokyo, 107-0062 (Japan); Fuji Security Systems. Co. Ltd., Iwato-cho 1, Shinjyuku-ku, Tokyo (Japan)

    2016-02-01

    Short-term earthquake (EQ) prediction is defined as prospective prediction with the time scale of about one week, which is considered to be one of the most important and urgent topics for the human beings. If this short-term prediction is realized, casualty will be drastically reduced. Unlike the conventional seismic measurement, we proposed the use of electromagnetic phenomena as precursors to EQs in the prediction, and an extensive amount of progress has been achieved in the field of seismo-electromagnetics during the last two decades. This paper deals with the review on this short-term EQ prediction, including the impossibility myth of EQs prediction by seismometers, the reason why we are interested in electromagnetics, the history of seismo-electromagnetics, the ionospheric perturbation as the most promising candidate of EQ prediction, then the future of EQ predictology from two standpoints of a practical science and a pure science, and finally a brief summary.

  7. Monte Carlo methods for electromagnetics

    CERN Document Server

    Sadiku, Matthew NO

    2009-01-01

    Until now, novices had to painstakingly dig through the literature to discover how to use Monte Carlo techniques for solving electromagnetic problems. Written by one of the foremost researchers in the field, Monte Carlo Methods for Electromagnetics provides a solid understanding of these methods and their applications in electromagnetic computation. Including much of his own work, the author brings together essential information from several different publications.Using a simple, clear writing style, the author begins with a historical background and review of electromagnetic theory. After addressing probability and statistics, he introduces the finite difference method as well as the fixed and floating random walk Monte Carlo methods. The text then applies the Exodus method to Laplace's and Poisson's equations and presents Monte Carlo techniques for handing Neumann problems. It also deals with whole field computation using the Markov chain, applies Monte Carlo methods to time-varying diffusion problems, and ...

  8. Electromagnetic field theories for engineering

    CERN Document Server

    Salam, Md Abdus

    2014-01-01

    A four year Electrical and Electronic engineering curriculum normally contains two modules of electromagnetic field theories during the first two years. However, some curricula do not have enough slots to accommodate the two modules. This book, Electromagnetic Field Theories, is designed for Electrical and Electronic engineering undergraduate students to provide fundamental knowledge of electromagnetic fields and waves in a structured manner. A comprehensive fundamental knowledge of electric and magnetic fields is required to understand the working principles of generators, motors and transformers. This knowledge is also necessary to analyze transmission lines, substations, insulator flashover mechanism, transient phenomena, etc. Recently, academics and researches are working for sending electrical power to a remote area by designing a suitable antenna. In this case, the knowledge of electromagnetic fields is considered as important tool.

  9. Classical electromagnetism in a nutshell

    CERN Document Server

    Garg, Anupam

    2012-01-01

    This graduate-level physics textbook provides a comprehensive treatment of the basic principles and phenomena of classical electromagnetism. While many electromagnetism texts use the subject to teach mathematical methods of physics, here the emphasis is on the physical ideas themselves. Anupam Garg distinguishes between electromagnetism in vacuum and that in material media, stressing that the core physical questions are different for each. In vacuum, the focus is on the fundamental content of electromagnetic laws, symmetries, conservation laws, and the implications for phenomena such as radiation and light. In material media, the focus is on understanding the response of the media to imposed fields, the attendant constitutive relations, and the phenomena encountered in different types of media such as dielectrics, ferromagnets, and conductors. The text includes applications to many topical subjects, such as magnetic levitation, plasmas, laser beams, and synchrotrons.

  10. Wave propagation in electromagnetic media

    CERN Document Server

    Davis, Julian L

    1990-01-01

    This is the second work of a set of two volumes on the phenomena of wave propagation in nonreacting and reacting media. The first, entitled Wave Propagation in Solids and Fluids (published by Springer-Verlag in 1988), deals with wave phenomena in nonreacting media (solids and fluids). This book is concerned with wave propagation in reacting media-specifically, in electro­ magnetic materials. Since these volumes were designed to be relatively self­ contained, we have taken the liberty of adapting some of the pertinent material, especially in the theory of hyperbolic partial differential equations (concerned with electromagnetic wave propagation), variational methods, and Hamilton-Jacobi theory, to the phenomena of electromagnetic waves. The purpose of this volume is similar to that of the first, except that here we are dealing with electromagnetic waves. We attempt to present a clear and systematic account of the mathematical methods of wave phenomena in electromagnetic materials that will be readily accessi...

  11. Frequency electromagnetic sounding with industrial power lines on Karelia-Kola geotraverse

    Directory of Open Access Journals (Sweden)

    А. Н. Шевцов

    2017-04-01

    Full Text Available The paper describes theory, method and first experimental results of research on the interaction between electromagnetic waves of extremely low and ultra low frequency (0.1-200 Hz, the Earth crust and ionosphere in the field of two mutually orthogonal industrial power lines, 109 and 120 km long, in the course of FENICS experiment (Fennoscandian Electrical conductivity from Natural and Induction Control Source soundings. The main focus was on the observation results along the line of Karelia-Kola geotraverse over a distance of 700 km from the source. High horizontal homogeneity of geoelectrical lithosphere section has been detected in the eastern part of the Baltic shield at depth range from 10-15 to 50-70 km. Parameters of «regular» lithosphere section have been specified to the depth of 60-70 km. As a result of inverse problem solution for the western part of Karelia and Central Finland, a zone of decreased transverse resistivity has been detected at the depth of 50-60 km, corresponding to the area, detected by seismic methods, where Moho boundary reaches the same depth.

  12. Radiation and propagation of electromagnetic waves

    CERN Document Server

    Tyras, George; Declaris, Nicholas

    1969-01-01

    Radiation and Propagation of Electromagnetic Waves serves as a text in electrical engineering or electrophysics. The book discusses the electromagnetic theory; plane electromagnetic waves in homogenous isotropic and anisotropic media; and plane electromagnetic waves in inhomogenous stratified media. The text also describes the spectral representation of elementary electromagnetic sources; the field of a dipole in a stratified medium; and radiation in anisotropic plasma. The properties and the procedures of Green's function method of solution, axial currents, as well as cylindrical boundaries a

  13. Advanced Model of Electromagnetic Launcher

    Directory of Open Access Journals (Sweden)

    Karel Leubner

    2015-01-01

    Full Text Available An advanced 2D model of electromagnetic launcher is presented respecting the influence of eddy currents induced in the accelerated ferromagnetic body. The time evolution of electromagnetic field in the system, corresponding forces acting on the projectile and time evolutions of its velocity and current in the field circuit are solved numerically using own application Agros2d. The results are then processed and evaluated in Wolfram Mathematica. The methodology is illustrated with an example whose results are discussed.

  14. Self-dual electromagnetic fields

    Science.gov (United States)

    Chubykalo, Andrew E.; Espinoza, Augusto; Kosyakov, B. P.

    2010-08-01

    We demonstrate the utility of self-dual fields in electrodynamics. Stable configurations of free electromagnetic fields can be represented as superpositions of standing waves, each possessing zero Poynting vector and zero orbital angular momentum. The standing waves are themselves superpositions of self-dual and anti-self-dual solutions. The idea of self-duality provides additional insights into the geometrical and spectral properties of stable electromagnetic configurations, such as those responsible for the formation of ball lightning.

  15. The law of electromagnetic force

    Directory of Open Access Journals (Sweden)

    V.J. Kutkovetskyy

    2014-06-01

    Full Text Available Calculation peculiarities for Lorentz force, Ampere force, interaction of parallel electric currents, and the moment of electrical machines are analyzed. They have exceptions on application, and they are the rules which result from the law of electromagnetic force as coordinate derivative of the operating magnetic flow. An addition to the direction of electromagnetic force action is proposed. Standards of salient-pole electrical machine designing are considered.

  16. Circuit oriented electromagnetic modeling using the PEEC techniques

    CERN Document Server

    Ruehli, Albert; Jiang, Lijun

    2017-01-01

    This book provides intuitive solutions to electromagnetic problems by using the Partial Eelement Eequivalent Ccircuit (PEEC) method. This book begins with an introduction to circuit analysis techniques, laws, and frequency and time domain analyses. The authors also treat Maxwell's equations, capacitance computations, and inductance computations through the lens of the PEEC method. Next, readers learn to build PEEC models in various forms: equivalent circuit models, non orthogonal PEEC models, skin-effect models, PEEC models for dielectrics, incident and radiate field models, and scattering PEEC models. The book concludes by considering issues like such as stability and passivity, and includes five appendices some with formulas for partial elements.

  17. THE PHASE REACTOR INDUCTANCE SELECTION TECHNIQUE FOR POWER ACTIVE FILTER

    Directory of Open Access Journals (Sweden)

    D. V. Tugay

    2016-12-01

    Full Text Available Purpose. The goal is to develop technique of the phase inductance power reactors selection for parallel active filter based on the account both low-frequency and high-frequency components of the electromagnetic processes in a power circuit. Methodology. We have applied concepts of the electrical circuits theory, vector analysis, mathematical simulation in Matlab package. Results. We have developed a new technique of the phase reactors inductance selection for parallel power active filter. It allows us to obtain the smallest possible value of THD network current. Originality. We have increased accuracy of methods of the phase reactor inductance selection for power active filter. Practical value. The proposed technique can be used in the design and manufacture of the active power filter for real objects of energy supply.

  18. The Mechanism Study of Alternating Arc(ACMagnetic Levitation Induction Motor

    Directory of Open Access Journals (Sweden)

    Li Zeng

    2015-01-01

    Full Text Available Magnetic levitation (no bearings motor by using magnetic force to make rotor suspend and drive realize its high or ultra-high speed rotating. The stator’s structure of traditional no bearing magnetic levitation motor is double winding which is polar logarithmic difference 1 of 2 sets of winding (torque winding and suspension winding and embedded in the stator. Using two inverter respectively for the two sets of winding to go into the same frequency current in order to realize the suspension of the rotor and motor’s driven, small carrying capacity of motor’s structure, controlling complex system. This paper based on the traditional motor technology puts forward a kind of arc principle and respectively decorates two arc motors in horizontal and vertical direction symmetric to rotor according to the electromagnetic bearing suspension technology that is constituted the arc magnetic levitation induction motor. Establishing air-gap transformation regular between rotor and stator (air-gap length motor is under the effect of interference. Based on the electromagnetic theory establishing distribution regular of the air-gap magnetic induction intensity. Virtual displacement principle is used to establish electromagnetism mathematical model and motor electromagnetism levitation. By the finite element analysis carrying on simulation research to the magnetic induction intensity, electric magnetic levitation force and distribution features of electromagnetic torque and so on.

  19. Introduction to engineering electromagnetics

    CERN Document Server

    Lee, Yeon Ho

    2013-01-01

    This text provides students with the missing link that can help them master the basic principles of electromagnetics. The concept of vector fields is introduced by starting with clear definitions of position, distance, and base vectors. The symmetries of typical configurations are discussed in detail, including cylindrical, spherical, translational, and two-fold rotational symmetries. To avoid serious confusion between symbols with two indices, the text adopts a new notation: a letter with subscript 1-2 for the work done in moving a unit charge from point 2 to point 1, in which the subscript 1-2 mimics the difference in potentials, while the hyphen implies a sense of backward direction, from 2 to 1. This text includes 300 figures in which real data are drawn to scale. Many figures provide a three-dimensional view. Each subsection includes a number of examples that are solved by examining rigorous approaches in steps. Each subsection ends with straightforward exercises and answers through which students can c...

  20. ELECTROMAGNET CALORIMETER (ECAL)

    CERN Multimedia

    R. Rusack

    Installation is under way of the last piece of the electromagnetic calorimeter. This is the preshower (ES) that sits in front of the two endcap calorimeters. The construction of the ES was completed in December and went through a detailed set of tests in December and January. The two preshower detectors have a total of 4300 silicon sensors with 137,000 strips. After final assembly and system testing in January, only two of the strips were found to be defective. Once CMS was fully opened a new support structure (‘Gazprom’) was put into place underneath the beam pipe, to support the Surkov platform, on which the preshower installation takes place. In the early hours of 26th February the first two Dees, which form the ‘ES+’ endcap,  were transported to P5 , a journey that took two and a half hours. The Dees, still inside environmental protection boxes, were then lowered  underground and moved to the ‘+’ end of CMS. Installation start...

  1. Electromagnetism of Bacterial Growth

    Science.gov (United States)

    Ainiwaer, Ailiyasi

    2011-10-01

    There has been increasing concern from the public about personal health due to the significant rise in the daily use of electrical devices such as cell phones, radios, computers, GPS, video games and television. All of these devices create electromagnetic (EM) fields, which are simply magnetic and electric fields surrounding the appliances that simultaneously affect the human bio-system. Although these can affect the human system, obstacles can easily shield or weaken the electrical fields; however, magnetic fields cannot be weakened and can pass through walls, human bodies and most other objects. The present study was conducted to examine the possible effects of bacteria when exposed to magnetic fields. The results indicate that a strong causal relationship is not clear, since different magnetic fields affect the bacteria differently, with some causing an increase in bacterial cells, and others causing a decrease in the same cells. This phenomenon has yet to be explained, but the current study attempts to offer a mathematical explanation for this occurrence. The researchers added cultures to the magnetic fields to examine any effects to ion transportation. Researchers discovered ions such as potassium and sodium are affected by the magnetic field. A formula is presented in the analysis section to explain this effect.

  2. SOLAR NANTENNA ELECTROMAGNETIC COLLECTORS

    Energy Technology Data Exchange (ETDEWEB)

    Steven D. Novack; Dale K. Kotter; Dennis Slafer; Patrick Pinhero

    2008-08-01

    This research explores a new efficient approach for producing electricity from the abundant energy of the sun. A nanoantenna electromagnetic collector (NEC) has been designed, prototyped, and tested. Proof of concept has been validated. The device targets mid-infrared wavelengths where conventional photovoltaic (PV) solar cells do not respond but is abundant in solar energy. The initial concept of designing NEC antennas was based on scaling of radio frequency antenna theory. This approach has proven unsuccessful by many due to not fully understanding and accounting for the optical behavior of materials in the THz region. Also until recent years the nanofabrication methods were not available to fabricate the optical antenna elements. We have addressed and overcome both technology barriers. Several factors were critical in successful implementation of NEC including: 1) frequency-dependent modeling of antenna elements, 2) selection of materials with proper THz properties and 3) novel manufacturing methods that enable economical large-scale manufacturing. The work represents an important step toward the ultimate realization of a low-cost device that will collect as well as convert this radiation into electricity, which will lead to a wide spectrum, high conversion efficiency, and low cost solution to complement conventional PVs.

  3. Designing screened enclosures: Part II.

    Science.gov (United States)

    Bearpark, J

    2006-03-01

    Techniques to achieve cost-effective emissions and immunity screening solutions that meet electromagnetic compatibility requirements were provided in Part I of this article, which covered design options for seams and gaskets. Part II continues with a discussion of materials compatibility, corrosion and apertures.

  4. Small electromagnetically clean satellite platform and advanced space instruments

    Science.gov (United States)

    Korepanov, Valery; Makarov, Oleksander; Belyayev, Serhiy; Lukenyuk, Adolf; Marusenkov, Andriy

    The Ukrainian space program in the branch of space scientific research is based on recent achievements in the development of small microsatellite platforms and advanced onboard instrumentation. The present state of both these activities is outlined in the report. First, the design and composition peculiarities of a new microsatellite platform dedicated to carry the high sensitive electromagnetic sensors and mass-spectrometers are presented. An open nonhermetic construction gives possibilities to divide efficiently service and scientific payload. This feature as well as special measures foreseen by the solar panels and cable harness layout allows electromagnetic interference decreasing and easy introducing of shielding and compensating facilities. Up to 4 booms deployment is foreseen by the platform construction to move away far enough the electromagnetic sensors from the satellite body allow realizing the ultimate sensors sensitivity up to highest international standards. An onboard data collection and processing unit is organized in such a way that it controls efficiently both service and scientific systems. Second, some recent advances are reported in the branch of onboard electromagnetic instrumentation creation. New combined sensor - wave probe - is developed and experimentally tested in laboratory plasma chamber and in spatial experiment. This is a unique device which permits measuring simultaneously in one point three physical values - spatial current density, magnetic field fluctuations and electric potential. Other recent versions of super-light flux-gate and induction coil sensors are described. The performances of both microsatellite platform and mentioned electromagnetic sensors are discussed and the results of experimental verification of their parameters are presented. This works were supported by NSAU contract No 1-02/03 and STCU grant 3165.

  5. EMC characteristics of composite structure - Electric/electromagnetic shielding attenuation

    Science.gov (United States)

    Wegertseder, P.; Breitsameter, R.

    1989-09-01

    The paper reports electric/electromagnetic shielding-attenuation experiments performed on different test boxes built with the same materials and processes as those to be used for the construction of a helicopter. The measurements are performed in the frequency range of 14 to 18 GHz, and the effects of different composite materials, jointing and bonding of structure parts of the boxes, application and bonding of the mesh, the construction of access panels, and conductive seals on these panels are assessed. It is demonstrated that moderate electric/electromagnetic shielding-attenuation values can be achieved by composite structures made from carbon, and materials and procedures required for high shielding attenuation are discussed.

  6. Response of Electrical Activity in an Improved Neuron Model under Electromagnetic Radiation and Noise.

    Science.gov (United States)

    Zhan, Feibiao; Liu, Shenquan

    2017-01-01

    Electrical activities are ubiquitous neuronal bioelectric phenomena, which have many different modes to encode the expression of biological information, and constitute the whole process of signal propagation between neurons. Therefore, we focus on the electrical activities of neurons, which is also causing widespread concern among neuroscientists. In this paper, we mainly investigate the electrical activities of the Morris-Lecar (M-L) model with electromagnetic radiation or Gaussian white noise, which can restore the authenticity of neurons in realistic neural network. First, we explore dynamical response of the whole system with electromagnetic induction (EMI) and Gaussian white noise. We find that there are slight differences in the discharge behaviors via comparing the response of original system with that of improved system, and electromagnetic induction can transform bursting or spiking state to quiescent state and vice versa. Furthermore, we research bursting transition mode and the corresponding periodic solution mechanism for the isolated neuron model with electromagnetic induction by using one-parameter and bi-parameters bifurcation analysis. Finally, we analyze the effects of Gaussian white noise on the original system and coupled system, which is conducive to understand the actual discharge properties of realistic neurons.

  7. Response of Electrical Activity in an Improved Neuron Model under Electromagnetic Radiation and Noise

    Science.gov (United States)

    Zhan, Feibiao; Liu, Shenquan

    2017-01-01

    Electrical activities are ubiquitous neuronal bioelectric phenomena, which have many different modes to encode the expression of biological information, and constitute the whole process of signal propagation between neurons. Therefore, we focus on the electrical activities of neurons, which is also causing widespread concern among neuroscientists. In this paper, we mainly investigate the electrical activities of the Morris-Lecar (M-L) model with electromagnetic radiation or Gaussian white noise, which can restore the authenticity of neurons in realistic neural network. First, we explore dynamical response of the whole system with electromagnetic induction (EMI) and Gaussian white noise. We find that there are slight differences in the discharge behaviors via comparing the response of original system with that of improved system, and electromagnetic induction can transform bursting or spiking state to quiescent state and vice versa. Furthermore, we research bursting transition mode and the corresponding periodic solution mechanism for the isolated neuron model with electromagnetic induction by using one-parameter and bi-parameters bifurcation analysis. Finally, we analyze the effects of Gaussian white noise on the original system and coupled system, which is conducive to understand the actual discharge properties of realistic neurons. PMID:29209192

  8. Response of Electrical Activity in an Improved Neuron Model under Electromagnetic Radiation and Noise

    Directory of Open Access Journals (Sweden)

    Feibiao Zhan

    2017-11-01

    Full Text Available Electrical activities are ubiquitous neuronal bioelectric phenomena, which have many different modes to encode the expression of biological information, and constitute the whole process of signal propagation between neurons. Therefore, we focus on the electrical activities of neurons, which is also causing widespread concern among neuroscientists. In this paper, we mainly investigate the electrical activities of the Morris-Lecar (M-L model with electromagnetic radiation or Gaussian white noise, which can restore the authenticity of neurons in realistic neural network. First, we explore dynamical response of the whole system with electromagnetic induction (EMI and Gaussian white noise. We find that there are slight differences in the discharge behaviors via comparing the response of original system with that of improved system, and electromagnetic induction can transform bursting or spiking state to quiescent state and vice versa. Furthermore, we research bursting transition mode and the corresponding periodic solution mechanism for the isolated neuron model with electromagnetic induction by using one-parameter and bi-parameters bifurcation analysis. Finally, we analyze the effects of Gaussian white noise on the original system and coupled system, which is conducive to understand the actual discharge properties of realistic neurons.

  9. Effect of 910-MHz Electromagnetic Field on Rat Bone Marrow

    Directory of Open Access Journals (Sweden)

    George Demsia

    2004-01-01

    Full Text Available Aiming to investigate the possibility of electromagnetic fields (EMF developed by nonionizing radiation to be a noxious agent capable of inducing genotoxicity to humans, in the current study we have investigated the effect of 910-MHz EMF in rat bone marrow. Rats were exposed daily for 2 h over a period of 30 consecutive days. Studying bone marrow smears from EMF-exposed and sham-exposed animals, we observed an almost threefold increase of micronuclei (MN in polychromatic erythrocytes (PCEs after EMF exposure. An induction of MN was also observed in polymorphonuclear cells. The induction of MN in female rats was less than that in male rats. The results indicate that 910-MHz EMF could be considered as a noxious agent capable of producing genotoxic effects.

  10. Electromagnetic acoustic transducers noncontacting ultrasonic measurements using EMATS

    CERN Document Server

    Hirao, Masahiko

    2017-01-01

    This second edition provides comprehensive information on electromagnetic acoustic transducers (EMATs), from the theory and physical principles of EMATs to the construction of systems and their applications to scientific and industrial ultrasonic measurements on materials. The original version has been complemented with selected ideas on ultrasonic measurement that have emerged since the first edition was released. The book is divided into four parts: PART I offers a self-contained description of the basic elements of coupling mechanisms along with the practical designing of EMATs for various purposes. Several implementations to compensate for EMATs’ low transfer efficiency are provided, along with useful tips on how to make an EMAT. PART II describes the principle of electromagnetic acoustic resonance (EMAR), which makes the most of EMATs’ contactless nature and is the most successful amplification mechanism for precise measurements of velocity and attenuation. PART III applies EMAR to studying physical ...

  11. Application of induction heating in food processing and cooking: A Review

    Science.gov (United States)

    Induction heating is an electromagnetic heating technology that has several advantages such as high safety, scalability, and high energy efficiency. It has been applied for a long time in metal processing, medical applications, and cooking. However, the application of this technology in the food pro...

  12. A framework for simulation and inversion in electromagnetics

    Science.gov (United States)

    Heagy, Lindsey J.; Cockett, Rowan; Kang, Seogi; Rosenkjaer, Gudni K.; Oldenburg, Douglas W.

    2017-10-01

    Simulations and inversions of electromagnetic geophysical data are paramount for discerning meaningful information about the subsurface from these data. Depending on the nature of the source electromagnetic experiments may be classified as time-domain or frequency-domain. Multiple heterogeneous and sometimes anisotropic physical properties, including electrical conductivity and magnetic permeability, may need be considered in a simulation. Depending on what one wants to accomplish in an inversion, the parameters which one inverts for may be a voxel-based description of the earth or some parametric representation that must be mapped onto a simulation mesh. Each of these permutations of the electromagnetic problem has implications in a numerical implementation of the forward simulation as well as in the computation of the sensitivities, which are required when considering gradient-based inversions. This paper proposes a framework for organizing and implementing electromagnetic simulations and gradient-based inversions in a modular, extensible fashion. We take an object-oriented approach for defining and organizing each of the necessary elements in an electromagnetic simulation, including: the physical properties, sources, formulation of the discrete problem to be solved, the resulting fields and fluxes, and receivers used to sample to the electromagnetic responses. A corresponding implementation is provided as part of the open source simulation and parameter estimation project SIMPEG (http://simpeg.xyz). The application of the framework is demonstrated through two synthetic examples and one field example. The first example shows the application of the common framework for 1D time domain and frequency domain inversions. The second is a field example that demonstrates a 1D inversion of electromagnetic data collected over the Bookpurnong Irrigation District in Australia. The final example is a 3D example which shows how the modular implementation is used to compute the

  13. Butterfly-valve inductive orientation detector

    Science.gov (United States)

    Garrett, Steven

    1980-04-01

    Relative changes of inductance ΔL/L of a single layer coil surrounding a thin electrically conducting disk which can rotate about an axis perpendicular to the coil axis are studied experimentally as a means of measuring angular displacements. ΔL/L is found to be a strong function of disk diameter and is weakly dependent on the ratio of disk thickness to electromagnetic skin depth when this ratio is of the order unity. Values of ΔL/L as a function of disk diameter are given for lead, brass and copper. Detection sensitivities using a resonant tank circuit or an astatic transformer are given in terms of ΔL/L and it is shown that sensitivities of the order of 10-3 to 10-4 deg are practical. Application of this system to the Rayleigh disk and cryogenic environments are emphasized and an expression for the magnetic torque due to detection currents is given.

  14. Induction in a Modular Learner.

    Science.gov (United States)

    Carroll, Susanne E.

    2002-01-01

    Presents a theory of inductive learning--Autonomous Induction Theory--a form of induction that takes place within the autonomous and modular representational systems of the language faculty. Argues that Autonomous Induction Theory is constrained enough to be taken seriously as a plausible approach to explaining second language acquisition.…

  15. Effect of Inductive Coil Geometry on the Thrust Efficiency of a Microwave Assisted Discharge Inductive Plasma Accelerator

    Science.gov (United States)

    Hallock, Ashley; Polzin, Kurt; Emsellem, Gregory

    2012-01-01

    Pulsed inductive plasma thrusters [1-3] are spacecraft propulsion devices in which electrical energy is capacitively stored and then discharged through an inductive coil. The thruster is electrodeless, with a time-varying current in the coil interacting with a plasma covering the face of the coil to induce a plasma current. Propellant is accelerated and expelled at a high exhaust velocity (O(10-100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, pulsed inductive plasma thrusters require high pulse energies to inductively ionize propellant. The Microwave Assisted Discharge Inductive Plasma Accelerator (MAD-IPA) [4, 5] is a pulsed inductive plasma thruster that addressees this issue by partially ionizing propellant inside a conical inductive coil via an electron cyclotron resonance (ECR) discharge. The ECR plasma is produced using microwaves and permanent magnets that are arranged to create a thin resonance region along the inner surface of the coil, restricting plasma formation, and in turn current sheet formation, to a region where the magnetic coupling between the plasma and the inductive coil is high. The use of a conical theta-pinch coil is under investigation. The conical geometry serves to provide neutral propellant containment and plasma plume focusing that is improved relative to the more common planar geometry of the Pulsed Inductive Thruster (PIT) [2, 3], however a conical coil imparts a direct radial acceleration of the current sheet that serves to rapidly decouple the propellant from the coil, limiting the direct axial electromagnetic acceleration in favor of an indirect acceleration mechanism that requires significant heating of the propellant within the volume bounded by the current sheet. In this paper, we describe thrust stand measurements performed to characterize the performance

  16. THE GENERATION OF THERMOELASTIC STRESS WAVES BY IMPULSIVE ELECTROMAGNETIC RADIATION.

    Science.gov (United States)

    ELECTROMAGNETIC RADIATION , ABSORPTION), (*STRESSES, ELECTROMAGNETIC RADIATION ), SURFACE PROPERTIES, INTERACTIONS, HEAT TRANSFER, ELASTIC PROPERTIES, ELECTROMAGNETIC PULSES, LASERS, MATHEMATICAL ANALYSIS, BOUNDARY VALUE PROBLEMS, SOLIDS

  17. Complex analysis of electromagnetic machines for vibro-impact technologies

    Science.gov (United States)

    Neyman, L. A.; Neyman, V. Yu

    2017-10-01

    For the implementation of high-energy impulse technologies of mechanical shock methods of secondary rock destruction, electromagnetic machines of vibro-impact action are of particular interest. Linear synchronous electromagnetic impact machine designs as a part of progress trend are considered where the head reciprocal motion is synchronized with 50 Hz power source pulses frequency applied to a winding or a system of windings. On the basis of identified differences of the head forced mechanical oscillation processes, merits and demerits of the work cycles of single or two-winding synchronous machine design variants are analyzed. Synchronous electromagnetic machines of a new design and principles of their control in a work cycle are presented. The specific half-wave interleaving of voltages applied to the windings allows reducing current amplitude and the influence of the impact drive on the power grid. To improve forced oscillation mode stability and precision, the new engineering solutions improving machines performances and exploitation conditions are proposed.

  18. Test beam results from the CMS electromagnetic calorimeter

    CERN Document Server

    Brunelière, R

    2004-01-01

    A precision lead tungstate crystal calorimeter is being constructed by the CMS collaboration. As a key part of the future CMS detector at the LHC, the electromagnetic calorimeter will play a major role in probing electroweak symmetry-breaking and searches for new physics. In order to check that the required performance of the electromagnetic calorimeter is attainable, every prototype is tested in real conditions within a beam of particles. In 2003 two modules of the electromagnetic calorimeter featuring the final mechanical design and electronic architecture have been tested with two different versions of the front-end electronics. In this paper a review of the main results of test beam campaigns in 2002 and 2003 are given. (7 refs).

  19. The electromagnetic and acoustic properties of smoke particulates

    Science.gov (United States)

    Churches, David K.

    The research work explores the Electromagnetic and Acoustic Properties of Smoke Particulates from real fires, and the initial development of an alternative method of smoke detection based on the study work. The research was entirely self-funded including the purchase of the experimental apparatus, test equipment and calibration to international standards. The study includes the properties of solid and liquid post combustion particulates in air suspension forming smoke plumes, and the associated fluid flow dynamics. As part of the study the electromagnetic and acoustic properties of smoke particulates, a somewhat unique detection method described as the ``Double Matrix Board System'' was developed and used. It was initially developed to assist in the electromagnetic study work, and was later modified to examine the acoustic properties. The published results of the research on the ``Double Matrix Board System'' and the details of the patent application for the device are included in the Appendices to the Thesis document.

  20. The combined method for uncertainty evaluation in electromagnetic radiation measurement

    Directory of Open Access Journals (Sweden)

    Kovačević Aleksandar M.

    2014-01-01

    Full Text Available Electromagnetic radiation of all frequencies represents one of the most common and fastest growing environmental influence. All populations are now exposed to varying degrees of electromagnetic radiation and the levels will continue to increase as technology advances. An electronic or electrical product should not generate electromagnetic radiation which may impact the environment. In addition, electromagnetic radiation measurement results need to be accompanied by quantitative statements about their accuracy. This is particularly important when decisions about product specifications are taken. This paper presents an uncertainty budget for disturbance power measurements of the equipment as part of electromagnetic radiation. We propose a model which uses a mixed distribution for uncertainty evaluation. The evaluation of the probability density function for the measurand has been done using the Monte Carlo method and a modified least-squares method (combined method. For illustration, this paper presents mixed distributions of two normal distributions, normal and rectangular, respectively. [Projekat Ministarstva nauke Republike Srbije, br. III 43009 i br. 171007

  1. Reasearch and Evaluation of Electromagnetic Fields of Refrigerators

    Directory of Open Access Journals (Sweden)

    Pranas Baltrėnas

    2013-12-01

    Full Text Available The use of refrigerators causes the occurence of electromagnetic fields that are invisible and intangible, which therefore makes difficulties in protecting ourselves from them. A refrigerator is an irreplaceable item in domestic household and thus can be hardly ignored by a modern way of human life. In order to preserve the characteristics of products, the refrigerator must operate continuously (24 hrs a day, regardless of the time of the year. This results in a huge increase in electricity consumption, which leads to energy consumption related pollution of the environment emitting CO2 gas. On these grounds, it is necessary to assess electromagnetic fields created by the refrigerator. Studies on electromagnetic fields produced by refrigerators were conducted in domestic premises where people spent a significant part of the day. For comparison purposes, five different power refrigerators were chosen (1 – 0.20 kW; 2 – 0.25 kW; 3 – 0.30 kW; 4 – 0.35 kW; 5 – 0.40 kW. The obtained results, according to the parameters of their electromagnetic fields, were presented in graphs and charts and showed that the values of electric and magnetic intensity of refrigerators depended on the distance and the power of the refrigerator. The conducted research also disclosed that none of tested refrigerators exceeded the permissible limits of electromagnetic fields.Article in Lithuanian

  2. The electromagnetic force field, fluid flow field and temperature profiles in levitated metal droplets

    Science.gov (United States)

    El-Kaddah, N.; Szekely, J.

    1982-01-01

    A mathematical representation was developed for the electromagnetic force field, the flow field, the temperature field (and for transport controlled kinetics), in a levitation melted metal droplet. The technique of mutual inductances was employed for the calculation of the electromagnetic force field, while the turbulent Navier - Stokes equations and the turbulent convective transport equations were used to represent the fluid flow field, the temperature field and the concentration field. The governing differential equations, written in spherical coordinates, were solved numerically. The computed results were in good agreement with measurements, regarding the lifting force, and the average temperature of the specimen and carburization rates, which were transport controlled.

  3. DESING OF AN INDUCTION HEATING SYSTEM WITH A HALF BRIDGE SERIES RESONANT INVERTER FOR DOMESTIC COOKING APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Selim KÖROĞLU

    2002-02-01

    Full Text Available The technique of heating by electromagnetic induction is a well established and an invaluable tool for industries engaged in the heat treatment of hot working of metals. In this study, it is shown that induction heating can succesfully be applied for domestic cooking applications. For this purpose, a complete induction heating system has been designed and a prototype of the proposed system has been built and tested. By the use of resonant technique, switching losses have been reduced significantly. Coil design procedure of the proposed system was also given. It is shown that induction heating system has many advantages among the conventional heaters.

  4. Electromagnetic aquametry electromagnetic wave interaction with water and moist substances

    CERN Document Server

    Kupfer, Klaus

    2006-01-01

    This book covers all aspects of Electromagnetic Aquametry. It summarizes the wide area of metrology and its applications in electromagnetic sensing of moist materials. The physical properties of water in various degrees of binding interacting with electromagnetic fields is presented by model systems. The book describes measurement methods and sensors in the frequency domain, TDR-techniques for environmental problems, methods and sensors for quality assessment of biological substances, and nuclear magnetic resonance techniques. Environmental sciences, as well as civil and geoengineering, fossil fuels, food and pharmaceutical science are the main fields of application. A very wide frequency sprectrum is used for dielectric measurement methods, but the microwave range is clearly dominant. Multiparameter methods as well as methods of principal components and artificial neural networks for density independent measurements are described.

  5. Induction and Natural Kinds

    Directory of Open Access Journals (Sweden)

    Howard Sankey

    1997-12-01

    Full Text Available The paper sketches an ontological solution to an epistemological problem in the philosophy of science. Taking the work of Hilary Kornblith and Brian Ellis as a point of departure, it presents a realist solution to the Humean problem of induction, which is based on a scientific essentialist interpretation of the principle of the uniformity of nature. More specifically, it is argued that use of inductive inference in science is rationally justified because of the existence of real, natural kinds of things, which are characterized as such by the essential properties which all members of a kind necessarily possess in common. The proposed response to inductive scepticism combines the insights of epistemic naturalism with a metaphysical outlook that is due to s cientific realism.

  6. Inductively Coupled Plasma Etching of III-V Semiconductors in BCl(3)-Based Chemistries: Part 1: GaAs, GaN, GaP, GaSb and AlGaAs

    Energy Technology Data Exchange (ETDEWEB)

    Abernathy, C.R,; Han, J.; Hobson, W.S.; Hong, J.; Lambers, E.S.; Lee, J.W.; Maeda, T.; Pearton, S.J.; Shul, R.J.

    1998-12-04

    BC13, with addition of Nz, Ar or Hz, is found to provide smooth anisotropic pattern transfer in GaAs, GaN, GaP, GaSb and AIGriAs under Inductively Coupled Plasma conditions, Maxima in the etch rates for these materials are observed at 33% N2 or 87$'40 Hz (by flow) addition to BC13, whereas Ar addition does not show this behavior. Maximum etch rates are typically much higher for GaAs, Gap, GaSb and AIGaAs (-1,2 @rein) than for GaN (-0.3 ymu'min) due to the higher bond energies of the iatter. The rates decrease at higher pressure, saturate with source power (ion flux) and tend to show maxima with chuck power (ion energy). The etched surfaces remain stoichiometric over abroad range of plasma conditions.

  7. COMPARISON OF ADJUSTABLE HIGH-PHASE ORDER INDUCTION MOTORS’ MERITS

    Directory of Open Access Journals (Sweden)

    V.S. Petrushin

    2016-03-01

    Full Text Available Purpose. Development of mathematical models of adjustable electrical drives with high-phase order induction motors for their merits analysis at static and dynamical modes. Methodology. At the mathematical modeling main kinds of physical processes taking place in the high-phase order induction motors are considered: electromagnetic, electromechanical, energetic, thermal, mechanical, vibroacoustic ones. Besides, functional as well as mass, frame and value indicators of frequency converters are taking into account which permits to consider technical and economical aspects of the adjustable induction electrical drives. Creation of high-phase order induction motors’ modifications in possible on the base of a stock 3-phase motors of basic design. Polyphase supply of induction motors is guaranteed by a number of the adjustable electrical drives’ power circuits. Results. Modelling of a number of adjustable electrical drives with induction motors of different phase number working on the same load by its character, value and required adjustment range is carried out. At the utilization of the family of characteristics including mechanical ones at different adjustment parameters on which loading mechanism’s characteristics are superimposed regulation curves representing dependences of electrical, energetic, thermal, mechanical, vibroacoustic quantities on the motors’ number of revolutions are obtained. Originality. The proposed complex models of adjustable electrical drives with high-phase order induction motors give a possibility to carry out the grounded choice of the drive’s acceptable variant. Besides, they can be used as design models at the development of adjustable high-phase order induction motors. Practical value. The investigated change of vibroacoustic indicators at static and dynamical modes has been determined decrease of these indicators in the drives with number of phase exceeding 3.

  8. The Impact of the Rotor Slot Number on the Behaviour of the Induction Motor

    Directory of Open Access Journals (Sweden)

    Konstantinos N. Gyftakis

    2013-01-01

    Full Text Available The impact of the rotor slot number selection on the induction motors is investigated. Firstly, analytical equations will reveal the spatial harmonic index of the air gap magnetic flux density, connected to the geometrical features and the saturation of the induction motor. Then, six motors with different rotor slot numbers are simulated and studied with FEM. The stator is identical in all motors. The motors are examined under time-harmonic analysis at starting and at 1440 rpm. Their electromagnetic characteristics, such as electromagnetic torque, stator current, and magnetic flux density, are extracted and compared to each other. The analysis will reveal that the proper rotor slot number selection has a strong impact on the induction motor performance.

  9. Electromagnetic fields in biological systems

    CERN Document Server

    Lin, James C

    2016-01-01

    As wireless technology becomes more sophisticated and accessible to more users, the interactions of electromagnetic fields with biological systems have captured the interest not only of the scientific community but also the general public. Unintended or deleterious biological effects of electromagnetic fields and radiation may indicate grounds for health and safety precautions in their use. Spanning static fields to terahertz waves, Electromagnetic Fields in Biological Systems explores the range of consequences these fields have on the human body. With contributions by an array of experts, topics discussed include: Essential interactions and field coupling phenomena, highlighting their importance in research on biological effects and in scientific, industrial, and medical applications Electric field interactions in cells, focusing on ultrashort, pulsed high-intensity fields The effect of exposure to naturally occurring and human-made static, low-frequency, and pulsed magnetic fields in biological systems Dosi...

  10. Electromagnetic Transients in Power Cables

    DEFF Research Database (Denmark)

    Silva, Filipe Faria Da; Bak, Claus Leth

    of electromagnetic phenomena associated to their operation, among them electromagnetic transients, increased as well. Transient phenomena have been studied since the beginning of power systems, at first using only analytical approaches, which limited studies to more basic phenomena; but as computational tools became...... more powerful, the analyses started to expand for the more complex phenomena. Being old phenomena, electromagnetic transients are covered in many publications, and classic books such as the 40-year-old Greenwood’s ‘‘Electric Transients in Power Systems’’ are still used to this day. However...... example.However, the book is not only intended for students . It can also be used by engineers who work in this area and need to understand the challenges/problems they are facing or who need to learn how to prepare their simulation models as well as their function. It also shows how to calculate...

  11. Objects of maximum electromagnetic chirality

    CERN Document Server

    Fernandez-Corbaton, Ivan

    2015-01-01

    We introduce a definition of the electromagnetic chirality of an object and show that it has an upper bound. The upper bound is attained if and only if the object is transparent for fields of one handedness (helicity). Additionally, electromagnetic duality symmetry, i.e. helicity preservation upon scattering, turns out to be a necessary condition for reciprocal scatterers to attain the upper bound. We use these results to provide requirements for the design of such extremal scatterers. The requirements can be formulated as constraints on the polarizability tensors for dipolar scatterers or as material constitutive relations. We also outline two applications for objects of maximum electromagnetic chirality: A twofold resonantly enhanced and background free circular dichroism measurement setup, and angle independent helicity filtering glasses.

  12. Electromagnetic contributions to pseudoscalar masses

    CERN Document Server

    Basak, S; Bernard, C; DeTar, C; Freeland, E; Freeman, W; Foley, J; Gottlieb, Steven; Heller, U M; Hetrick, J E; Laiho, J; Levkova, L; Oktay, M; Osborn, J; Sugar, R L; Torok, A; Toussaint, D; Van de Water, R S; Zhou, R

    2013-01-01

    We report on the calculation by the MILC Collaboration of the electromagnetic effects on kaon and pion masses. These masses are computed in QCD with dynamical (asqtad staggered) quarks plus quenched photons at three lattice spacings varying from 0.12 to 0.06 fm. The masses are fit to staggered chiral perturbation theory with NLO electromagnetic terms, as well as analytic terms at higher order. We extrapolate the results to physical light-quark masses and to the continuum limit. At the current stage of the analysis, most, but not all, of the systematic errors have been estimated. The main goal is the comparison of kaon electromagnetic splittings to those of the pion, i.e., an evaluation of the corrections to "Dashen's theorem." This in turn will allow us to significantly reduce the systematic errors in our determination of m_u/m_d.

  13. Moving Manifolds in Electromagnetic Fields

    Directory of Open Access Journals (Sweden)

    David V. Svintradze

    2017-08-01

    Full Text Available We propose dynamic non-linear equations for moving surfaces in an electromagnetic field. The field is induced by a material body with a boundary of the surface. Correspondingly the potential energy, set by the field at the boundary can be written as an addition of four-potential times four-current to a contraction of the electromagnetic tensor. Proper application of the minimal action principle to the system Lagrangian yields dynamic non-linear equations for moving three dimensional manifolds in electromagnetic fields. The equations in different conditions simplify to Maxwell equations for massless three surfaces, to Euler equations for a dynamic fluid, to magneto-hydrodynamic equations and to the Poisson-Boltzmann equation.

  14. CIME School on "Computational Electromagnetism"

    CERN Document Server

    Valli, Alberto

    2015-01-01

    Presenting topics that have not previously been contained in a single volume, this book offers an up-to-date review of computational methods in electromagnetism, with a focus on recent results in the numerical simulation of real-life electromagnetic problems and on theoretical results that are useful in devising and analyzing approximation algorithms. Based on four courses delivered in Cetraro in June 2014, the material covered includes the spatial discretization of Maxwell’s equations in a bounded domain, the numerical approximation of the eddy current model in harmonic regime, the time domain integral equation method (with an emphasis on the electric-field integral equation) and an overview of qualitative methods for inverse electromagnetic scattering problems. Assuming some knowledge of the variational formulation of PDEs and of finite element/boundary element methods, the book is suitable for PhD students and researchers interested in numerical approximation of partial differential equations and scienti...

  15. Theory of an Electromagnetic Mass Accelerator for Achieving Hypervelocities

    Science.gov (United States)

    Thom, Karlheinz; Norwood, Joseph., Jr.

    1961-01-01

    It is shown that for any electromagnetic accelerator which employs an electromagnetic force for driving the projectile and uses the projectile as the heat sink for the energy dissipated in it by ohmic heating, the maximum velocity attainable without melting is a function of the mass of the projectile. Therefore, for hypervelocities a large projectile mass is required and thus a power supply of very large capacity is necessary. It is shown that the only means for reducing the power requirement is maximizing the gradient of the mutual inductance. In the scheme of the sliding-coil accelerator investigated herein, the gradient of the mutual inductance is continuously maintained at a high value. It is also shown that for minimum length of the accelerator, the current must be kept constant despite the rise in induced voltage during acceleration. The use of a capacitor bank as an energy source with the condition that the current be kept constant is investigated. Experiments at low velocities are described.

  16. CONSIDERATIONS ON CONTACTLESS ELECTROMAGNETIC MEASUREMENT OF HUMIDITY IN PEDOLOGY

    Directory of Open Access Journals (Sweden)

    Tudor BURLAN-ROTAR

    2017-05-01

    Full Text Available To put into practice the conventional determination of resistivity by the galvanic method, requires a relatively large amount of labor and is, therefore, expensive. At the basis of any interpretation are the lateral or vertical variations of re sistivity. The high cost of resistivity maps execution generally means that fewer measurements are made than desirable, with the result that, either (i the explored area is not large enough to establish a reasonable background, against which the anomaly areas are to be delineated, or (ii the anomaly areas are obscure and lack definition. The application of electromagnetic techniques (EM for measuring soil resistivity or conductivity has been known for a long time. Conductivity is preferable in inductive techniques, as instrumentation readings are generally directly proportional to conductivity and inversely proportional to resistivity. The operating principle of this method is: a Tx coil transmitter, supplied with alternating current at an audio frequency, is placed on the ground. An Rx coil receiver is located at a short distance, s, away from the Tx coil. The magnetic field varies in time and the Tx coil induces very small currents in the ground. These currents generate a secondary magnetic field, Hs, which is sensed by the Rx receiver coil, together with primary magnetic field Hp. The ratio of the secondary field, Hs, to the primary magnetic field, Hp, (Hs/Hp is directly proportional to terrain conductivity. Measuring this ratio, it is possible to construct a device which measures the terrain conductivity by contactless, direct-reading electromagnetic technique. (linear meter. This latest technique for measuring conductivity by electromagnetic induction, using Very Low Frequency (VLF, is a non-invasive, non-destructive sampling method. The measurements can be done quickly and are not expensive. The Electromagnetic induction technology was originally developed for the mining industry, and has been used

  17. Mass transfers through electromagnetically stirred interfaces - nuclear wastes application

    Energy Technology Data Exchange (ETDEWEB)

    Courtessole, C.; Etay, J. [CNRS-SIMAP-EPM ENSEEG BP75 38402 St Martin d' Heres Cedex (France); SAADI, B.; Allibert, M. [23 Av. Marcellin Berthelot 38100 Grenoble (France)

    2009-06-15

    Molten salts are good heat conductors. They are identified for future applications such as the implementation of a GEN IV nuclear reactor, heat transportation between 650 deg. and 850 deg. C for the hydrogen generation purpose, and electrolysis of aluminum between 850 deg. and 950 deg. C. Generally speaking, these salts are aggressive for materials that maintain them such as transportation, mixing and chemical composition. That is why we want to study and implement induction devices to replace the functions of these materials by electromagnetic forces. This will allow a dual benefit: improving the longevity and reduce secondary wastes. In the present work, we use a specific electromagnetic device for accelerating mass transfers through liquid / liquid interface. To reduce barriers to transfer, the interface is shacked at a frequency near of one of its natural frequencies. To achieve this, we use an adapted dual-frequency electromagnetic field. A pyrometallurgy pre-industrial graded facility, based on cold crucible technique, is used to carry out numerous experiments on the extraction of actinides and other elements from a fluorinated salt into a liquid metal phase containing a reducing agent such as magnesium, aluminium or lithium. At time t = 0, the metallic alloy is poured under the molten salt. Metallic samples are taken from the bulk at known time intervals. Later, the samples are analysed using optical ICP. Transfer rate and kinetics are deduced from obtained experimental data. Compare to other treatment, the present one is found to lead faster to a higher rate of transfer. (authors)

  18. Studies in electromagnetic compatibility of optical and digital current and voltage transformers

    Science.gov (United States)

    Lebedev, V. D.; Yablokov, A. A.

    2017-02-01

    The use of microprocessor devices for relay protection and automation, devices for measuring and determining electric power quality permits the introduction and development of digital circuits leading from primary current and voltage transformers. The use of optical channels for digital circuits addresses the problem of offsetting electromagnetic interference and voltage shift. Creating optical and digital current and voltage transformers with digitization of signals already at high measuring transformer voltage is the best solution for the above problem of mechanical engineering in the field of electromagnetic compatibility of high voltage measuring transformers. However, a difficulty arises in ensuring electromagnetic compatibility of sensors and microelectronic equipment adjoining live parts. The present study is devoted to examining the impact of electromagnetic fields on sensors and solving the problems of electromagnetic compatibility of optical and digital current and voltage transformers.

  19. Application of COMSOL Multiphysics in Thermal Effect Analysis of Electromagnetic Active Vibration Absorber

    Science.gov (United States)

    Hang, Su; Xue-tao, Weng

    2017-11-01

    At present, there are some researches in the thermal analysis of electromagnetic absorbers. The heating principle of electromagnetic absorber magnetic circuit is analysed, and the finite element method is used to numerically solve the temperature field in the working process of electromagnetic vibration absorber. The magnetic circuit simulation model of electromagnetic vibration absorber is established in Comsol Multiphysics finite element analysis software. And the grid Division, simulation analysis of the vibration absorber magnetic circuit structure of the internal temperature distribution, you can get the vibration absorber magnetic circuit in the working process of the temperature field of two-dimensional distribution graphics and magnetic circuit structure of different parts of the temperature rise contrast chart. The conclusion provides some theoretical reference for the design and research of electromagnetic active vibration absorber.

  20. Ultraregular inductive limits

    Directory of Open Access Journals (Sweden)

    Jan Kucera

    1990-01-01

    Full Text Available An inductive limit E=indlim En is ultraregular if it is regular and each set B⊂En, which is bounded in E, is also bounded in En. A necessary and sufficient condition for ultraregularity of E is given provided each En is an LF-space which is closed in En+1.

  1. Modeling Induction Motor Imbalances

    DEFF Research Database (Denmark)

    Armah, Kabenla; Jouffroy, Jerome; Duggen, Lars

    2016-01-01

    This paper gives a study into the development of a generalized model for a three-phase induction motor that offers flexibility of simulating balanced and unbalanced parameter scenarios. By analyzing the interaction of forces within the motor, we achieve our main objective of deriving the system...

  2. Using Continuity Induction

    Science.gov (United States)

    Hathaway, Dan

    2011-01-01

    Here is a technique for proving the fundamental theorems of analysis that provides a unified way to pass from local properties to global properties on the real line, just as ordinary induction passes from local implication (if true for "k", the theorem is true for "k" + 1) to a global conclusion in the natural numbers.

  3. Electromagnetic Compatibility of Matrix Converter System

    Directory of Open Access Journals (Sweden)

    S. Fligl

    2006-12-01

    Full Text Available The presented paper deals with matrix converters pulse width modulation strategies design with emphasis on the electromagnetic compatibility. Matrix converters provide an all-silicon solution to the problem of converting AC power from one frequency to another, offering almost all the features required of an ideal static frequency changer. They possess many advantages compared to the conventional voltage or current source inverters. A matrix converter does not require energy storage components as a bulky capacitor or an inductance in the DC-link, and enables the bi-directional power flow between the power supply and load. The most of the contemporary modulation strategies are able to provide practically sinusoidal waveforms of the input and output currents with negligible low order harmonics, and to control the input displacement factor. The perspective of matrix converters regarding EMC in comparison with other types of converters is brightly evident because it is no need to use any equipment for power factor correction and current and voltage harmonics reduction. Such converter with proper control is properly compatible both with the supply mains and with the supplied load. A special digital control system was developed for the realized experimental test bed which makes it possible to achieve greater throughput of the digital control system and its variability.

  4. Electromagnetic pulsed thermography for natural cracks inspection

    Science.gov (United States)

    Gao, Yunlai; Tian, Gui Yun; Wang, Ping; Wang, Haitao; Gao, Bin; Woo, Wai Lok; Li, Kongjing

    2017-02-01

    Emerging integrated sensing and monitoring of material degradation and cracks are increasingly required for characterizing the structural integrity and safety of infrastructure. However, most conventional nondestructive evaluation (NDE) methods are based on single modality sensing which is not adequate to evaluate structural integrity and natural cracks. This paper proposed electromagnetic pulsed thermography for fast and comprehensive defect characterization. It hybrids multiple physical phenomena i.e. magnetic flux leakage, induced eddy current and induction heating linking to physics as well as signal processing algorithms to provide abundant information of material properties and defects. New features are proposed using 1st derivation that reflects multiphysics spatial and temporal behaviors to enhance the detection of cracks with different orientations. Promising results that robust to lift-off changes and invariant features for artificial and natural cracks detection have been demonstrated that the proposed method significantly improves defect detectability. It opens up multiphysics sensing and integrated NDE with potential impact for natural understanding and better quantitative evaluation of natural cracks including stress corrosion crack (SCC) and rolling contact fatigue (RCF).

  5. Electromagnetic pulsed thermography for natural cracks inspection

    Science.gov (United States)

    Gao, Yunlai; Tian, Gui Yun; Wang, Ping; Wang, Haitao; Gao, Bin; Woo, Wai Lok; Li, Kongjing

    2017-01-01

    Emerging integrated sensing and monitoring of material degradation and cracks are increasingly required for characterizing the structural integrity and safety of infrastructure. However, most conventional nondestructive evaluation (NDE) methods are based on single modality sensing which is not adequate to evaluate structural integrity and natural cracks. This paper proposed electromagnetic pulsed thermography for fast and comprehensive defect characterization. It hybrids multiple physical phenomena i.e. magnetic flux leakage, induced eddy current and induction heating linking to physics as well as signal processing algorithms to provide abundant information of material properties and defects. New features are proposed using 1st derivation that reflects multiphysics spatial and temporal behaviors to enhance the detection of cracks with different orientations. Promising results that robust to lift-off changes and invariant features for artificial and natural cracks detection have been demonstrated that the proposed method significantly improves defect detectability. It opens up multiphysics sensing and integrated NDE with potential impact for natural understanding and better quantitative evaluation of natural cracks including stress corrosion crack (SCC) and rolling contact fatigue (RCF). PMID:28169361

  6. Circuit modeling for electromagnetic compatibility

    CERN Document Server

    Darney, Ian B

    2013-01-01

    Very simply, electromagnetic interference (EMI) costs money, reduces profits, and generally wreaks havoc for circuit designers in all industries. This book shows how the analytic tools of circuit theory can be used to simulate the coupling of interference into, and out of, any signal link in the system being reviewed. The technique is simple, systematic and accurate. It enables the design of any equipment to be tailored to meet EMC requirements. Every electronic system consists of a number of functional modules interconnected by signal links and power supply lines. Electromagnetic interference

  7. Electromagnetic compatibility principles and applications

    CERN Document Server

    Weston, David A

    2001-01-01

    This totally revised and expanded reference/text provides comprehensive, single-source coverage of the design, problem solving, and specifications of electromagnetic compatibility (EMC) into electrical equipment/systems-including new information on basic theories, applications, evaluations, prediction techniques, and practical diagnostic options for preventing EMI through cost-effective solutions. Offers the most recent guidelines, safety limits, and standards for human exposure to electromagnetic fields! Containing updated data on EMI diagnostic verification measurements, as well as over 900 drawings, photographs, tables, and equations-500 more than the previous edition

  8. Mathematical methods of electromagnetic theory

    CERN Document Server

    Friedrichs, Kurt O

    2014-01-01

    This text provides a mathematically precise but intuitive introduction to classical electromagnetic theory and wave propagation, with a brief introduction to special relativity. While written in a distinctive, modern style, Friedrichs manages to convey the physical intuition and 19th century basis of the equations, with an emphasis on conservation laws. Particularly striking features of the book include: (a) a mathematically rigorous derivation of the interaction of electromagnetic waves with matter, (b) a straightforward explanation of how to use variational principles to solve problems in el

  9. Electromagnetic geothermometry theory, modeling, practice

    CERN Document Server

    Spichak, Viacheslav V

    2015-01-01

    Electromagnetic Geothermometry explores, presents and explains the new technique of temperature estimation within the Earth's interior; the Electromagnetic technique will identify zones of geothermal anomalies and thus provides locations for deep drilling. This book includes many case studies from geothermal areas such as Travale (Italy), Soultz-sous-Forêts (France) and Hengill (Iceland), allowing the author and reader to draw conclusions regarding the dominating heat transfer mechanisms, location of its sources and to constrain the locations for drilling of the new boreholes. Covering a to

  10. Integral equation methods for electromagnetics

    CERN Document Server

    Volakis, John

    2012-01-01

    This text/reference is a detailed look at the development and use of integral equation methods for electromagnetic analysis, specifically for antennas and radar scattering. Developers and practitioners will appreciate the broad-based approach to understanding and utilizing integral equation methods and the unique coverage of historical developments that led to the current state-of-the-art. In contrast to existing books, Integral Equation Methods for Electromagnetics lays the groundwork in the initial chapters so students and basic users can solve simple problems and work their way up to the mo

  11. Measurement of advanced electromagnetic radiation

    OpenAIRE

    Bajlo, Darko

    2017-01-01

    For the purpose of detecting advanced electromagnetic radiation predicted by Wheeler-Feynman absorber theory for the case of incomplete absorption of retarded electromagnetic radiation, pulses in duration of 6 ns to 24 ns, wavelength from 91 cm to 200 cm where supplied to three different transmitting antennas. Detection was done with a λ/20 monopole antenna in the advanced time window at a time 2r/c before the arrival of the center of the retarded pulse. At distances ranging from 430 cm to 18...

  12. Time domain electromagnetic method for petroleum exploration. Part 3. Case study in Yoneyama area; Sekiyu tansa ni okeru TDEM ho data shutoku to kaiseki ni tsuite. 3. Niigataken Yoneyama chiiki deno tekiyorei

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, H.; Mitsuhata, Y. [Japan National Oil Corp., Tokyo (Japan); Shiga, N. [Mitsui Mineral Development Engineering Co. Ltd., Tokyo (Japan)

    1996-05-01

    The result is reported of a TDEM method-based survey for oil exploration conducted in the Yoneyama district, Niigata Prefecture. The survey covered the southern part of the sedimentary basin in the prefecture, known for the poor quality of the seismic prospecting data that had been recorded. The purpose of the TDEM method-assisted survey was to probe the high-resistivity volcanic rock structure and low-resistivity sedimentary layer, and to know their details. The obtained data were subjected to interpretation by use of the 1D inversion method. A 4000m-deep level was subjected to interpretation, 34 data were inputted, and the early model consisted of 20 layers. As the result, it was found that there was a high-resistivity layer ranging from the ground surface down to a depth of approximately 500m, that a low-resistivity layer 2500-3000m in thickness lay thereunder, and that the lowest layer had a high resistivity of approximately 100 Ohm m. By comparing these data with the geological structure, structures were disclosed corresponding to the rock bed depth, Ukawa syncline, Ishiguro anticline, and Yoneyama mountain mass. 3 refs., 10 figs., 1 tab.

  13. On the Divergenceless Property of the Magnetic Induction Field

    Directory of Open Access Journals (Sweden)

    Sergio Severini

    2013-01-01

    Full Text Available Maxwell's equations beautifully describe the electromagnetic fields properties. In what follows we will be interested in giving a new perspective to divergence-free Maxwell’s equations regarding the magnetic induction field: ∇·B→(r→,t=0. To this end we will consider some physical aspects of a system consisting of massive nonrelativistic charged particles, as sources of an electromagnetic field (e.m. propagating in free space. In particular the link between conservation of total momentum and divergence-free condition for the magnetic induction B→ field will be deeply investigated. This study presents a new context in which the necessary condition for the divergence-free property of the magnetic induction field in the whole space, known as solenoidality condition, directly comes from the conservation of total momentum for the system, that is, sources and field. This work, in general, leads to results that leave some open questions on the existence, or at least the observability, of magnetic monopoles, theoretically plausible only under suitable symmetry assumptions as we will show.

  14. An approach to calculating metal particle detection in lubrication oil based on a micro inductive sensor

    Science.gov (United States)

    Wu, Yu; Zhang, Hongpeng

    2017-12-01

    A new microfluidic chip is presented to enhance the sensitivity of a micro inductive sensor, and an approach to coil inductance change calculation is introduced for metal particle detection in lubrication oil. Electromagnetic knowledge is used to establish a mathematical model of an inductive sensor for metal particle detection, and the analytic expression of coil inductance change is obtained by a magnetic vector potential. Experimental verification is carried out. The results show that copper particles 50–52 µm in diameter have been detected; the relative errors between the theoretical and experimental values are 7.68% and 10.02% at particle diameters of 108–110 µm and 50–52 µm, respectively. The approach presented here can provide a theoretical basis for an inductive sensor in metal particle detection in oil and other areas of application.

  15. Parametric Instabilities of Electromagnetic Waves in Plasmas,

    Science.gov (United States)

    A simple formalism for the parametric decay of an intense, coherent electromagnetic wave into an electrostatic wave and scattered electromagnetic ... waves in a homogeneous plasma is developed. Various instabilities including Brillouin and Raman backscattering, Compton scattering, filamentation and

  16. Higher-order techniques in computational electromagnetics

    CERN Document Server

    Graglia, Roberto D

    2016-01-01

    Higher-Order Techniques in Computational Electromagnetics explains 'high-order' techniques that can significantly improve the accuracy, computational cost, and reliability of computational techniques for high-frequency electromagnetics, such as antennas, microwave devices and radar scattering applications.

  17. Bathymetry, electromagnetic streamlines and the marine controlled source electromagnetic method

    Science.gov (United States)

    Pethick, Andrew; Harris, Brett

    2014-07-01

    Seafloor topography must influence the strength and direction of electromagnetic fields generated during deep ocean controlled source electromagnetic surveying. Neither mathematical equation nor rules of thumb provide a clear perspective of how changes in water column thickness alters electromagnetic fields that engulf hundreds of cubic kilometres of air, ocean, host and reservoir. We use streamline visualisation to provide a generalised representation of how electromagnetic fields propagate into a 2D geo-electrical setting that includes strong bathymetry. Of particular interest are: (i)' dead zones' where electric fields at the ocean floor are demonstrated to be weak and (ii) the 'airwave' that appears in the electric field streamlines as circulating vortices with a shape that is clearly influenced by changes in ocean depth. Our analysis of the distribution of electric fields for deep and shallow water examples alludes to potential benefits from placement of receivers and/or transmitters higher in the water column as is the case for towed receiver geometries. Real-time streamline representation probably holds the most value at the survey planning stage, especially for shallow water marine EM surveys where ocean bottom topography is likely to be consequential.

  18. ORDNANCE CORPS VIEWS ELECTROMAGNETIC RADIATION HAZARDS TO WEAPONS SYSTEMS,

    Science.gov (United States)

    EXPLOSIVES INITIATORS, * ELECTROMAGNETIC RADIATION ), HAZARDS, ELECTROMAGNETIC SHIELDING, RADIOFREQUENCY POWER, ANTENNAS, ATTENUATORS, IMPEDANCE MATCHING, SENSITIVITY, WEAPON SYSTEMS, MODULATION, CIRCUITS, BROADBAND

  19. The measurable distinction between the spin and orbital angular momenta of electromagnetic radiation

    Directory of Open Access Journals (Sweden)

    James H. Crichton

    2000-07-01

    Full Text Available We show how the angular momentum of electromagnetic radiation may be decomposed into spin and orbital parts, of which the spin part is measurable in terms of Stokes parameters, thereby providing an unambiguous, gauge-invariant, distinction between the two parts.

  20. Electromagnetic Fields Exposure Limits

    Science.gov (United States)

    2018-01-01

    justified. This report documents the findings and the consensus reached. Published January 2018 Distribution and Availability on Back Cover...scientifically justified. This report documents the findings and the consensus reached. ii STO-TR-HFM-189 The NATO Science and...Reserved ISBN 978-92-837-2041-6 Single copies of this publication or of a part of it may be made for individual use only by those organisations or

  1. Landau levels for electromagnetic wave

    CERN Document Server

    Zyuzin, Vladimir A

    2016-01-01

    In this paper we show that the frequencies of propagating electromagnetic wave (photon) in rotating dielectric media obey Landau quantization. We show that the degeneracy of right and left helicities of photons is broken on the lowest Landau level. In spatially homogeneous system this level is shown to be helical, i.e. left and right helical photons counter-propagate.

  2. Solved problems in classical electromagnetism

    CERN Document Server

    Franklin, Jerrold

    2018-01-01

    This original Dover publication is the companion to a new edition of the author's Classical Electromagnetism: Second Edition. The latter volume will feature only basic answers; this book will contain some problems from the reissue as well as many other new ones. All feature complete, worked-out solutions and form a valuable source of problem-solving material for students.

  3. Nanocomposites for electromagnetic radiation protection

    Science.gov (United States)

    Petrunin, V. F.

    2016-12-01

    Specific features that characterize nanoparticles and which are due to their small size and allow one to enhance the interaction between the electromagnetic radiation and nanostructured materials and to develop the effective protection of man and equipment against harmful uncontrolled radiation are reported. Examples of the development of nanocomposite radar absorbing materials that can be used for protection of man and equipment are presented.

  4. Electromagnetic Levitation of a Disc

    Science.gov (United States)

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

    2012-01-01

    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…

  5. Airborne electro-magnetic system

    Energy Technology Data Exchange (ETDEWEB)

    1977-09-01

    Tridem is a three-frequency in-phase and quadrature measuring, fixed configuration, airborne electromagnetic system developed by Scintrex. It has been in operation in Canada since 1975. It is expected that the system will be used in high resolution, multiple natural resource surveys for base metals, uranium, sand and gravel, coal, lignite, groundwater and civil engineering purposes.

  6. Explanations, Education, and Electromagnetic Fields.

    Science.gov (United States)

    Friedman, Sharon M.

    Explaining complex scientific and environmental subjects in the mass media is difficult to do, particularly under such constraints as short deadlines and lack of space or time. When a scientific controversy and human health risk are involved, this becomes an even harder task to accomplish. The subject of electromagnetic fields (EMF) involves…

  7. Contributions of Maxwell to Electromagnetism

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 8; Issue 5. Contributions of Maxwell to Electromagnetism. P V Panat. General Article Volume 8 Issue 5 May 2003 pp 17-29. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/008/05/0017-0029. Keywords.

  8. Radiation leakage from electromagnetic oven

    Directory of Open Access Journals (Sweden)

    Abdurrahman Khalil

    2015-10-01

    Results & Discussions: The measurements have been done at some houses in Erbil city, according to the source of background radiation exist before measuring data. Our data compared with standard safe range of radiation data. Results showed that there is radiation leak form all type of electromagnetic oven and all at the order of safety compared with standard value.

  9. Cardiovascular Responses to Electromagnetic Radiation

    African Journals Online (AJOL)

    Dr Olaleye Samuel

    fatigue. ABSTRACT. Electromagnetic signaling has recently greatly increased due to mobile telephony and computers some of which radiate much and have wide spectra. The radiations are also reflected and thus form standing waves with incoming ones. In cities both the direct and reflected radiations form complex ...

  10. Nanocomposites for electromagnetic radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Petrunin, V. F., E-mail: VFPetrunin@mephi.ru [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute) (Russian Federation)

    2016-12-15

    Specific features that characterize nanoparticles and which are due to their small size and allow one to enhance the interaction between the electromagnetic radiation and nanostructured materials and to develop the effective protection of man and equipment against harmful uncontrolled radiation are reported. Examples of the development of nanocomposite radar absorbing materials that can be used for protection of man and equipment are presented.

  11. Numerical computation of electromagnetic field for general static and axisymmetric current distribution

    Science.gov (United States)

    Fukushima, Toshio

    2017-12-01

    We developed a numerical method to compute the electromagnetic field of arbitrary static and axisymmetric current distribution. The method (i) numerically evaluates a double integral of the electrostatic and magnetostatic potentials of an infinitely thin ring current by the split quadrature method using the double exponential rules, and (ii) derives the electrostatic field and the magnetostatic induction by numerically differentiating the numerically integrated potentials by the central difference formula. A comparison with the exact solution for a poloidal current distribution with an anisotropic Gaussian damping confirmed the 14- and 9-digit accuracy of the potential and the field/induction computed by the new method.

  12. Effects of Pulsed Electromagnetic Fields on Osteoporosis Model

    Science.gov (United States)

    Xiaowei, Yang; Liming, Wang; Guan, Z. C.; Yaou, Zhang; Xiangpeng, Wang

    The purpose of this paper was to investigate the preventive effects and long term effects of extremely low frequency pulsed electromagnetic fields (PEMFs), generated by circular coils and pulsed electromagnetic fields stimulators, on osteoporosis in bilaterally ovariectomized rats. In preventive experiment, thirty three-month old female Sprague-Dawley rats were randomly divided into three different groups: sham (SHAM), ovariectomy (OVX), PEMFs stimulation (PEMFs). All rats were subjected to bilaterally ovariectomy except those in SHAM group. The PEMFs group was exposed to pulsed electromagnetic fields with frequency 15 Hz, peak magnetic induction density 2.2mT and exposure time 2 hours per day. The bone mineral density (BMD) of vertebra and left femur were measured by dual energy X-ray absorptiometry at eighth week, twelfth week and sixteenth week after surgery. In long term effects experiment, forty four rats were randomly divided into sham (14 rats, SHAM), ovariectomy group (10 rats, OVX), 15Hz PEMFs group(10 rats, 15Hz) and 30Hz PEMFs group(10 rats, 30Hz) at twenty-sixth week after surgery. Rats in PEMFs groups were stimulated sixteen weeks. In preventive experiment, the Corrected BMD of vertebra and femur was significantly higher than that of OVX group after 16 weeks (P<0.001, P<0.001 respectively). In long term effects experiment, the vertebral BMD of 15Hz PEMFs group and 30Hz PEMFs group was significantly higher than that of OVX groups (P<0.01, P<0.05 respectively). The experimental results demonstrated that extremely low intensity, low frequency, single pulsed electromagnetic fields significantly slowed down the loss of corrected vertebral and femoral BMD in bilaterally ovariectomized rats and suggest that PEMFs may be beneficial in the treatment of osteoporosis.

  13. Inductive Communication System Design Summary

    Science.gov (United States)

    1978-09-01

    The report documents the experience obtained during the design and development of the Inductive Communications System used in the Morgantown People Mover. The Inductive Communications System is used to provide wayside-to-vehicle and vehicle-to-waysid...

  14. Induction technique in manufacturing preforms

    Science.gov (United States)

    Frauenhofer, M.; Ströhlein, T.; Fabig, S.; Böhm, S.; Herbeck, L.; Dilger, K.

    2008-09-01

    The prepreg technology is a state-of-the-art method to produce high-performance CFRP parts. Due to the high material prices, the restricted process rate, and limitations to the component complexity, in future, more and more parts will be assembled by using liquid composite moulding. Especially in the case of series larger than 100 parts per year, the LCM technology offers the best cost-effectiveness. This technology is based on resin injection into dry multilayer fibre textiles (preforms). The Institute of Joining and Welding (TU, Braunschweig), together with the Institute of Composite Structures and Adaptive Systems (DLR), has elaborated a new technology to speed up the preform process, which is the most labour-intensive step within the LCM process chain. A novel concept to consolidate binder-coated fabrics is under development. By applying the high energy transfer rate of induction technology, it is possible to heat up a preform with rates up to 50 K/s to melt the binder and consolidate the preform.

  15. CONSIDERATIONS ON CONTACTLESS MEASUREMENTS IN HYDROGEOLOGY USING VERY LOW FREQUENCY ELECTROMAGNETIC TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Tudor BURLAN-ROTAR

    2017-05-01

    Full Text Available Studies of groundwater consist in data acquisition, their processing and interpretation. In areas of interest hydrogeological is assumed that there is a network of wells drilled. This network provides a first in the hydrogeological information. Electromagnetic (EM mapping through the use of such areas, using data obtained from existing network of wells drilled, calibration and confirmation. Measurements using the EM can highlight the existence of several layers with different characteristics: clay, limestone, sand, etc. Studies of groundwater interpretation are used for developing a regional hydrogeologic model. The application of electromagnetic techniques for measuring soil resistivity or conductivity has been known for a long time. Conductivity is preferable in inductive techniques, as instrumentation readings are generally directly proportional to conductivity and inversely proportional to resistivity. The operating principle of this method is: a Tx coil transmitter, supplied with alternating current at an audio frequency, is placed on the ground. An Rx coil receiver is located at a short distance, s, away from the Tx coil. The magnetic field varies in time and the Tx coil induces very small currents in the ground. These currents generate a secondary magnetic field, Hs, which is sensed by the Rx receiver coil, together, with primary magnetic field Hp. The ratio of the secondary field, Hs, to the primary magnetic field, Hp, (Hs/Hp is directly proportional to terrain conductivity. Measuring this ratio, it is possible to construct a device which measures the terrain conductivity by contactless, direct-reading electromagnetic technique (linear meter. This technique for measuring conductivity by electromagnetic induction, using Very Low Frequency (VLF, is a non-intrusive, non-destructive sampling method. The measurements can be done quickly and are not expensive. The Electromagnetic induction technology was originally developed for the mining

  16. Health hazards and electromagnetic fields.

    Science.gov (United States)

    Saunders, T

    2003-11-01

    Biological rhythms, physical wellbeing and mental states are dependent on our electrical brainwave system interacting with the extremely weak electromagnetic fields generated by the Earth's telluric and Cosmic radiations. In a single generation, since the evolution of humankind over millions of years, we are exposed to a wide range of powerful, artificially generated electromagnetic radiation which adversely affects the subtle balance in nature's energy fields and has become the source of so-called 'diseases of civilization'. This also includes electromagnetic sensitivity. Generally, there is a lack of awareness and understanding of the impact electromagnetic fields can have upon health and wellbeing.Our ancestors were acutely aware that certain locations, were perceived to have a positive energy field which was beneficial to health and vitality. Over time, these areas are now referred to as sacred sites for spiritual ceremony and as healing centres. In contrast, there are other geographical locations that can have a negative effect upon health and these are known as geopathic stress zones. It is believed that such zones can interfere with the brain's normal function that inhibits the release of melatonin and other endocrine secretions needed to replenish the immune system. Geopathic stress can affect animals and plant life as well as human beings and significantly contributes to sick building syndrome (SBS). Whilst there is an increasing body of opinion amongst eminent researchers and scientists who are addressing these issues, the establishment professions are slow to change. However, very gradually, modern allopathic medicine and attitudes are beginning to recognise the extraordinary wisdom and efficacy of ancient traditions such as acupuncture, light, colour and other therapies based on the understanding and treatment of the interaction of a person's electromagnetic subtle body and the immediate environment. These and many other 'complementary' therapies may

  17. Inductive Supervised Quantum Learning

    Science.gov (United States)

    Monràs, Alex; Sentís, Gael; Wittek, Peter

    2017-05-01

    In supervised learning, an inductive learning algorithm extracts general rules from observed training instances, then the rules are applied to test instances. We show that this splitting of training and application arises naturally, in the classical setting, from a simple independence requirement with a physical interpretation of being nonsignaling. Thus, two seemingly different definitions of inductive learning happen to coincide. This follows from the properties of classical information that break down in the quantum setup. We prove a quantum de Finetti theorem for quantum channels, which shows that in the quantum case, the equivalence holds in the asymptotic setting, that is, for large numbers of test instances. This reveals a natural analogy between classical learning protocols and their quantum counterparts, justifying a similar treatment, and allowing us to inquire about standard elements in computational learning theory, such as structural risk minimization and sample complexity.

  18. Induction motor control

    Science.gov (United States)

    Hansen, Irving G.

    1990-01-01

    Electromechanical actuators developed to date have commonly ultilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilized induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high-frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high-frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  19. Induction motor control

    Science.gov (United States)

    Hansen, Irving G.

    Electromechanical actuators developed to date have commonly ultilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilized induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high-frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high-frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  20. [Mood induction procedures: a critical review].

    Science.gov (United States)

    Gilet, A-L

    2008-06-01

    For a long period in the history of psychological research, emotion and cognition have been studied independently, as if one were irrelevant to the other. The renewed interest of researchers for the study of the relations between cognition and emotion has led to the development of a range of laboratory methods for inducing temporary mood states. This paper aims to review the main mood induction procedures allowing the induction of a negative mood as well as a positive mood, developed since the pioneer study of Schachter and Singer [Psychol Rev 69 (1962) 379-399] and to account for the usefulness and problems related to the use of such techniques. The first part of this paper deals with the detailed presentation of some of the most popular mood induction procedures according to their type: simple (use of only one mood induction technique) or combined (association of two or more techniques at once). The earliest of the modern techniques is the Velten Mood Induction Procedure [Behav Res Ther 6 (1968) 473-482], which involves reading aloud sixty self-referent statements progressing from relative neutral mood to negative mood or dysphoria. Some researchers have varied the procedure slightly by changing the number of the statements [Behav Res Ther 21 (1983) 233-239, Br J Clin Psychol 21 (1982) 111-117, J Pers Soc Psychol 35 (1977) 625-636]. Various other mood induction procedures have been developed including music induction [Cogn Emotion 11 (1997) 403-432, Br J Med Psychol 55 (1982) 127-138], film clip induction [J Pers Soc Psychol 20 (1971) 37-43, Cogn Emotion 7 (1993) 171-193, Rottenberg J, Ray RR, Gross JJ. Emotion elicitation using films. In: Coan JA, Allen JJB, editors. The handbook of emotion elicitation and assessment. New York: Oxford University Press, 2007], autobiographical recall [J Clin Psychol 36 (1980) 215-226, Jallais C. Effets des humeurs positives et négatives sur les structures de connaissances de type script. Thèse de doctorat non publi