Modeling and characterization of an electromagnetic system for the estimation of Frequency Response Function of spindle

NASA Astrophysics Data System (ADS)

Tlalolini, David; Ritou, Mathieu; Rabréau, Clément; Le Loch, Sébastien; Furet, Benoit

2018-05-01

The paper presents an electromagnetic system that has been developed to measure the quasi-static and dynamic behavior of machine-tool spindle, at different spindle speeds. This system consists in four Pulse Width Modulation amplifiers and four electromagnets to produce magnetic forces of ± 190 N for the static mode and ± 80 N for the dynamic mode up to 5 kHz. In order to measure the Frequency Response Function (FRF) of spindle, the applied force is required, which is a key issue. A dynamic force model is proposed in order to obtain the load from the measured current in the amplifiers. The model depends on the exciting frequency and on the magnetic characteristics of the system. The predicted force at high speed is validated with a specific experiment and the performance limits of the experimental device are investigated. The FRF obtained with the electromagnetic system is compared to a classical tap test measurement.

Footwear scanning systems and methods

DOEpatents

Fernandes, Justin L.; McMakin, Douglas L.; Sheen, David M.; Tedeschi, Jonathan R.

2017-07-25

Methods and apparatus for scanning articles, such as footwear, to provide information regarding the contents of the articles are described. According to one aspect, a footwear scanning system includes a platform configured to contact footwear to be scanned, an antenna array configured to transmit electromagnetic waves through the platform into the footwear and to receive electromagnetic waves from the footwear and the platform, a transceiver coupled with antennas of the antenna array and configured to apply electrical signals to at least one of the antennas to generate the transmitted electromagnetic waves and to receive electrical signals from at least another of the antennas corresponding to the electromagnetic waves received by the others of the antennas, and processing circuitry configured to process the received electrical signals from the transceiver to provide information regarding contents within the footwear.

Phase control of squeezed state in double electromagnetically induced transparency system with a loop-transition structure

NASA Astrophysics Data System (ADS)

Li, Yuan; Zhou, Yusheng; Wang, Yong; Ling, Qiang; Chen, Bing; Dou, Yan; Zhang, Wei; Gao, Weiqing; Guo, Zhiqiang; Zhang, Junxiang

2018-03-01

We theoretically study the squeezed probe light passing through a double electromagnetically induced transparency (DEIT) system, in which a microwave field and two coupling lights drive a loop transition. It is shown that the output squeezing can be maintained in both two transparency windows of DEIT, and it can also be manipulated by the relative phase of the three driving fields. The influence of the intensity of applied fields and the optical depth of atoms on the squeezing is also investigated. This study offers possibilities to manipulate the squeezing propagation in atomic media by the phase of electromagnetic fields.

Real-time wideband cylindrical holographic surveillance system

DOEpatents

Sheen, D.M.; McMakin, D.L.; Hall, T.E.; Severtsen, R.H.

1999-01-12

A wideband holographic cylindrical surveillance system is disclosed including a transceiver for generating a plurality of electromagnetic waves; antenna for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; the transceiver also receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; a computer for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and a display for displaying the processed information to determine nature of the target. The computer has instructions to apply Fast Fourier Transforms and obtain a three dimensional cylindrical image. 13 figs.

Real-time holographic surveillance system

DOEpatents

Collins, H.D.; McMakin, D.L.; Hall, T.E.; Gribble, R.P.

1995-10-03

A holographic surveillance system is disclosed including means for generating electromagnetic waves; means for transmitting the electromagnetic waves toward a target at a plurality of predetermined positions in space; means for receiving and converting electromagnetic waves reflected from the target to electrical signals at a plurality of predetermined positions in space; means for processing the electrical signals to obtain signals corresponding to a holographic reconstruction of the target; and means for displaying the processed information to determine nature of the target. The means for processing the electrical signals includes means for converting analog signals to digital signals followed by a computer means to apply a backward wave algorithm. 21 figs.

An electromagnetic method for removing the communication blackout with a space vehicle upon re-entry into the atmosphere

NASA Astrophysics Data System (ADS)

Cheng, Jianjun; Jin, Ke; Kou, Yong; Hu, Ruifeng; Zheng, Xiaojing

2017-03-01

When a hypersonic vehicle travels in the Earth and Mars atmosphere, the surface of the vehicle is surrounded by a plasma layer, which is an envelope of ionized air, created from the compression and heat of the atmosphere by the shock wave. The vehicles will lose contact with ground stations known as the reentry communication blackout. Based on the magnetohydrodynamic framework and electromagnetic wave propagation theory, an analytical model is proposed to describe the effect of the effectiveness of electromagnetic mitigation scheme on removing the reentry communication blackout. C and Global Positioning System (GPS) bands, two commonly used radio bands for communication, are taken as the cases to discuss the effectiveness of the electromagnetic field mitigation scheme. The results show that the electron density near the antenna of vehicles can be reduced by the electromagnetic field, and the required external magnetic field strength is far below the one in the magnetic window method. The directions of the external electric field and magnetic field have a significant impact on the effectiveness of the mitigation scheme. Furthermore, the effect of electron collisions on the required applied electromagnetic field is discussed, and the result indicates that electron collisions are a key factor to analyze the electromagnetic mitigation scheme. Finally, the feasible regions of the applied electromagnetic field for eliminating blackout are given. These investigations could have a significant benefit on the design and optimization of electromagnetic mitigation scheme for the blackout problem.

Computational Electromagnetic Modeling of SansEC(Trade Mark) Sensors

NASA Technical Reports Server (NTRS)

Smith, Laura J.; Dudley, Kenneth L.; Szatkowski, George N.

2011-01-01

This paper describes the preliminary effort to apply computational design tools to aid in the development of an electromagnetic SansEC resonant sensor composite materials damage detection system. The computational methods and models employed on this research problem will evolve in complexity over time and will lead to the development of new computational methods and experimental sensor systems that demonstrate the capability to detect, diagnose, and monitor the damage of composite materials and structures on aerospace vehicles.

Engaging Students in Applied Electromagnetics at the University of San Diego

ERIC Educational Resources Information Center

Lumori, M. L. D.; Kim, E. M.

2010-01-01

Two possible topical approaches that have been applied to teaching an upper-division undergraduate electrical engineering applied electromagnetics course are presented. Each approach was applied to one of two offerings of the course, taught in different semesters. In either case, the course includes the study of electromagnetic theory and…

System engineering study of electrodynamic tether as a spaceborne generator and radiator of electromagnetic waves in the ULF/ELF frequency band

NASA Technical Reports Server (NTRS)

Estes, R. D.; Grossi, M. D.; Lorenzini, E. C.

1986-01-01

The transmission and generation by orbiting tethered satellite systems of information carrying electromagnetic waves in the ULF/ELF frequency band to the Earth at suitably high signal intensities was examined and the system maintaining these intensities in their orbits for long periods of time without excessive onboard power requirements was investigated. The injection quantity power into electromagnetic waves as a function of system parameters such as tether length and orbital height was estimated. The basic equations needed to evaluate alternataing current tethered systems for external energy requirements are presented. The energy equations to tethered systems with various lengths, tether resistances, and radiation resistances, operating at different current values are applied. Radiation resistance as a function of tether length and orbital height is discussed. It is found that ULF/ELF continuously radiating systems could be maintained in orbit with moderate power requirements. The effect of tether length on the power going into electromagnetic waves and whether a single or dual tether system is preferable for the self-driven mode is discussed. It is concluded that the single tether system is preferable over the dual system.

EMC analysis of MOS-1

NASA Astrophysics Data System (ADS)

Ishizawa, Y.; Abe, K.; Shirako, G.; Takai, T.; Kato, H.

The electromagnetic compatibility (EMC) control method, system EMC analysis method, and system test method which have been applied to test the components of the MOS-1 satellite are described. The merits and demerits of the problem solving, specification, and system approaches to EMC control are summarized, and the data requirements of the SEMCAP (specification and electromagnetic compatibility analysis program) computer program for verifying the EMI safety margin of the components are sumamrized. Examples of EMC design are mentioned, and the EMC design process and selection method for EMC critical points are shown along with sample EMC test results.

Application of superconducting technology to earth-to-orbit electromagnetic launch systems

NASA Technical Reports Server (NTRS)

Hull, J. R.; Carney, L. M.

1988-01-01

Benefits may occur by incorporating superconductors, both existing and those currently under development, in one or more parts of a large-scale electromagnetic launch (EML) system that is capable of delivering payloads from the surface of the Earth to space. The use of superconductors for many of the EML components results in lower system losses; consequently, reductions in the size and number of energy storage devices are possible. Applied high-temperature superconductivity may eventually enable novel design concepts for energy distribution and switching. All of these technical improvements have the potential to reduce system complexity and lower payload launch costs.

Optical Phased Array Using Guided Resonance with Backside Reflectors

NASA Technical Reports Server (NTRS)

Horie, Yu (Inventor); Arbabi, Amir (Inventor); Faraon, Andrei (Inventor)

2016-01-01

Methods and systems for controlling the phase of electromagnetic waves are disclosed. A device can consist of a guided resonance grating layer, a spacer, and a reflector. A plurality of devices, arranged in a grid pattern, can control the phase of reflected electromagnetic phase, through refractive index control. Carrier injection, temperature control, and optical beams can be applied to control the refractive index.

Optical phased array using guided resonance with backside reflectors

DOEpatents

Horie, Yu; Arbabi, Amir; Faraon, Andrei

2016-11-01

Methods and systems for controlling the phase of electromagnetic waves are disclosed. A device can consist of a guided resonance grating layer, a spacer, and a reflector. A plurality of devices, arranged in a grid pattern, can control the phase of reflected electromagnetic phase, through refractive index control. Carrier injection, temperature control, and optical beams can be applied to control the refractive index.

Optical phased array using guided resonance with backside reflectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horie, Yu; Arbabi, Amir; Faraon, Andrei

2018-03-13

Methods and systems for controlling the phase of electromagnetic waves are disclosed. A device can consist of a guided resonance grating layer, a spacer, and a reflector. A plurality of devices, arranged in a grid pattern, can control the phase of reflected electromagnetic phase, through refractive index control. Carrier injection, temperature control, and optical beams can be applied to control the refractive index.

Optical Phased Array Using Guided Resonance with Backside Reflectors

NASA Technical Reports Server (NTRS)

Horie, Yu (Inventor); Arbabi, Amir (Inventor); Faraon, Andrei (Inventor)

2018-01-01

Methods and systems for controlling the phase of electromagnetic waves are disclosed. A device can consist of a guided resonance grating layer, a spacer, and a reflector. A plurality of devices, arranged in a grid pattern, can control the phase of reflected electromagnetic phase, through refractive index control. Carrier injection, temperature control, and optical beams can be applied to control the refractive index.

A Systems-Based Risk Assessment Framework for Intentional Electromagnetic Interference (IEMI) on Critical Infrastructures.

PubMed

Oakes, Benjamin Donald; Mattsson, Lars-Göran; Näsman, Per; Glazunov, Andrés Alayón

2018-06-01

Modern infrastructures are becoming increasingly dependent on electronic systems, leaving them more vulnerable to electrical surges or electromagnetic interference. Electromagnetic disturbances appear in nature, e.g., lightning and solar wind; however, they may also be generated by man-made technology to maliciously damage or disturb electronic equipment. This article presents a systematic risk assessment framework for identifying possible, consequential, and plausible intentional electromagnetic interference (IEMI) attacks on an arbitrary distribution network infrastructure. In the absence of available data on IEMI occurrences, we find that a systems-based risk assessment is more useful than a probabilistic approach. We therefore modify the often applied definition of risk, i.e., a set of triplets containing scenario, probability, and consequence, to a set of quadruplets: scenario, resource requirements, plausibility, and consequence. Probability is "replaced" by resource requirements and plausibility, where the former is the minimum amount and type of equipment necessary to successfully carry out an attack scenario and the latter is a subjective assessment of the extent of the existence of attackers who possess the motivation, knowledge, and resources necessary to carry out the scenario. We apply the concept of intrusion areas and classify electromagnetic source technology according to key attributes. Worst-case scenarios are identified for different quantities of attacker resources. The most plausible and consequential of these are deemed the most important scenarios and should provide useful decision support in a countermeasures effort. Finally, an example of the proposed risk assessment framework, based on notional data, is provided on a hypothetical water distribution network. © 2017 Society for Risk Analysis.

Shuttle Communications and Tracking, Avionics, and Electromagnetic Compatibility

NASA Technical Reports Server (NTRS)

deSilva, K.; Hwu, Shian; Kindt, Kaylene; Kroll, Quin; Nuss, Ray; Romero, Denise; Schuler, Diana; Sham, Catherine; Scully, Robert

2011-01-01

By definition, electromagnetic compatibility (EMC) is the capability of components, sub-systems, and systems, to operate in their intended electromagnetic environment, within an established margin of safety, and at design levels of performance. Practice of the discipline itself incorporates knowledge of various aspects of applied physics, materials science, and engineering across the board, and includes control and mitigation of undesirable electromagnetic interaction between intentional and unintentional emitters and receivers of radio frequency energy, both within and external to the vehicle; identification and control of the hazards of non-ionizing electromagnetic radiation to personnel, ordnance, and fuels and propellants; and vehicle and system protection from the direct and indirect effects of lightning and various other forms of electrostatic discharge (ESD) threats, such as triboelectrification and plasma charging. EMC is extremely complex and far-reaching, affecting in some degree every aspect of the vehicle s design and operation. The most successful efforts incorporate EMC design features and techniques throughout design and fabrication of the vehicle s structure and components, as well as appropriate operational considerations with regard to electromagnetic threats in the operational environment, from the beginning of the design effort to the end of the life cycle of the manufactured product. This approach yields the highest design performance with the lowest cost and schedule impact.

Sample levitation and melt in microgravity

NASA Technical Reports Server (NTRS)

Moynihan, Philip I. (Inventor)

1990-01-01

A system is described for maintaining a sample material in a molten state and away from the walls of a container in a microgravity environment, as in a space vehicle. A plurality of sources of electromagnetic radiation, such as an infrared wavelength, are spaced about the object, with the total net electromagnetic radiation applied to the object being sufficient to maintain it in a molten state, and with the vector sum of the applied radiation being in a direction to maintain the sample close to a predetermined location away from the walls of a container surrounding the sample. For a processing system in a space vehicle that orbits the Earth, the net radiation vector is opposite the velocity of the orbiting vehicle.

Sample levitation and melt in microgravity

NASA Technical Reports Server (NTRS)

Moynihan, Philip I. (Inventor)

1987-01-01

A system is described for maintaining a sample material in a molten state and away from the walls of a container in a microgravity environment, as in a space vehicle. A plurality of sources of electromagnetic radiation, such as of an infrared wavelength, are spaced about the object, with the total net electromagnetic radiation applied to the object being sufficient to maintain it in a molten state, and with the vector sum of the applied radiation being in a direction to maintain the sample close to a predetermined location away from the walls of a container surrounding the sample. For a processing system in a space vehicle that orbits the Earth, the net radiation vector is opposite the velocity of the orbiting vehicle.

A summary of the research program in the broad field of electronics

NASA Technical Reports Server (NTRS)

1972-01-01

Summary reports of research projects covering solid state materials, semiconductors and devices, quantum electronics, plasmas, applied electromagnetics, electrical engineering systems to include control communication, computer and power systems, biomedical engineering and mathematical biosciences.

EM Modelling of RF Propagation Through Plasma Plumes

NASA Astrophysics Data System (ADS)

Pandolfo, L.; Bandinelli, M.; Araque Quijano, J. L.; Vecchi, G.; Pawlak, H.; Marliani, F.

2012-05-01

Electric propulsion is a commercially attractive solution for attitude and position control of geostationary satellites. Hall-effect ion thrusters generate a localized plasma flow in the surrounding of the satellite, whose impact on the communication system needs to be qualitatively and quantitatively assessed. An electromagnetic modelling tool has been developed and integrated into the Antenna Design Framework- ElectroMagnetic Satellite (ADF-EMS). The system is able to guide the user from the plume definition phases through plume installation and simulation. A validation activity has been carried out and the system has been applied to the plume modulation analysis of SGEO/Hispasat mission.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beer, Neil Reginald; Lee, Abraham; Hatch, Andrew

A non-contact system for sorting monodisperse water-in-oil emulsion droplets in a microfluidic device based on the droplet's contents and their interaction with an applied electromagnetic field or by identification and sorting.

High-Fidelity Simulations of Electromagnetic Propagation and RF Communication Systems

DTIC Science & Technology

2017-05-01

addition to high -fidelity RF propagation modeling, lower-fidelity mod- els, which are less computationally burdensome, are available via a C++ API...expensive to perform, requiring roughly one hour of computer time with 36 available cores and ray tracing per- formed by a single high -end GPU...ER D C TR -1 7- 2 Military Engineering Applied Research High -Fidelity Simulations of Electromagnetic Propagation and RF Communication

A 65-kV insulated gate bipolar transistor switch applied in damped AC voltages partial discharge detection system.

PubMed

Jiang, J; Ma, G M; Luo, D P; Li, C R; Li, Q M; Wang, W

2014-02-01

Damped AC voltages detection system (DAC) is a productive way to detect the faults in power cables. To solve the problems of large volume, complicated structure and electromagnetic interference in existing switches, this paper developed a compact solid state switch based on electromagnetic trigger, which is suitable for DAC test system. Synchronous electromagnetic trigger of 32 Insulated Gate Bipolar Transistors (IGBTs) in series was realized by the topological structure of single line based on pulse width modulation control technology. In this way, external extension was easily achieved. Electromagnetic trigger and resistor-capacitor-diode snubber circuit were optimized to reduce the switch turn-on time and circular layout. Epoxy encapsulating was chosen to enhance the level of partial discharge initial voltage (PDIV). The combination of synchronous trigger and power supply is proposed to reduce the switch volume. Moreover, we have overcome the drawback of the electromagnetic interference and improved the detection sensitivity of DAC by using capacitor storage energy to maintain IGBT gate driving voltage. The experimental results demonstrated that the solid-state switch, with compact size, whose turn-on time was less than 400 ns and PDIV was more than 65 kV, was able to meet the actual demands of 35 kV DAC test system.

Multimode electromagnetic target discriminator: preliminary data results

NASA Astrophysics Data System (ADS)

Black, Christopher J.; McMichael, Ian T.; Nelson, Carl V.

2004-09-01

This paper describes the Multi-mode Electromagnetic Target Discriminator (METD) sensor and presents preliminary results from recent field experiments. The METD sensor was developed for the US Army RDECOM NVESD by The Johns Hopkins University Applied Physics Laboratory. The METD, based on the technology of the previously developed Electromagnetic Target Discriminator (ETD), is a spatial scanning electromagnetic induction (EMI) sensor that uses both the time-domain (TD) and the frequency-domain (FD) for target detection and classification. Data is collected with a custom data acquisition system and wirelessly transmitted to a base computer. We show that the METD has a high signal-to-noise ratio (SNR), the ability to detect voids created by plastic anti-tank (AT) mines, and is practical for near real-time data processing.

Cooling systems and hybrid A/C systems using an electromagnetic radiation-absorbing complex

DOEpatents

Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

2015-05-19

A method for powering a cooling unit. The method including applying electromagnetic (EM) radiation to a complex, where the complex absorbs the EM radiation to generate heat, transforming, using the heat generated by the complex, a fluid to vapor, and sending the vapor from the vessel to a turbine coupled to a generator by a shaft, where the vapor causes the turbine to rotate, which turns the shaft and causes the generator to generate the electric power, wherein the electric powers supplements the power needed to power the cooling unit

Guidance of Magnetic Nanocontainers for Treating Alzheimer's Disease Using an Electromagnetic, Targeted Drug-Delivery Actuator.

PubMed

Do, Ton Duc; Ul Amin, Faiz; Noh, Yeongil; Kim, Myeong Ok; Yoon, Jungwon

2016-03-01

The "impermeability" of the blood-brain barrier (BBB) has hindered effective treatment of central nervous system (CNS) disorders such as Alzheimer's disease (AD), which is one of the most common neurodegenerative disorders. A drug can be delivered to a targeted disease site effectively by applying a strong electromagnetic force to the conjugate of a drug and magnetic nanocontainers. This study developed a novel nanotechnology-based strategy to deliver therapeutic agents to the brain via the BBB as a possible therapeutic approach for AD. First, a novel approach for an electromagnetic actuator for guiding nanocontainers is introduced. Then, we analyzed the in vivo uptake in mice experimentally to evaluate the capacity of the nanocontainers. In the mouse model, we demonstrated that magnetic particles can cross the normal BBB when subjected to external electromagnetic fields of 28 mT (0.43 T/m) and 79.8 mT (1.39 T/m). Our study also assessed the differential effects of pulsed (0.25, 0.5, and 1 Hz) and constant magnetic fields on the transport of particles across the BBB in mice injected with magnetic nanoparticles (MNPs) via a tail vein. The applied magnetic field was either kept constant or pulsed on and off. Relative to a constant magnetic field, the rate of MNP uptake and transport across the BBB was enhanced significantly by a pulsed magnetic field. Localization inside the brain was established using fluorescent MNPs. These results using 770-nm fluorescent carboxyl magnetic nanocontainers demonstrated the feasibility of the proposed electromagnetic targeted drug delivery actuator. These results establish an effective strategy for regulating the biodistribution of MNPs in the brain through the application of an external electromagnetic field. This might be a valuable targeting system for AD diagnosis and therapy.

Electromagnetic information transfer through aqueous system.

PubMed

Foletti, Alberto; Ledda, Mario; Lolli, Maria Grazia; Grimaldi, Settimio; Lisi, Antonella

2017-01-01

Several beneficial effects of the electromagnetic information transfer through aqueous system (EMITTAS) procedure have previously been reported in vitro. The clinical potential of this procedure has also started to be evaluated. Information flow in biological systems can be investigated through chemical and molecular approaches or by a biophysical approach focused on endogenous electrodynamic activities. Electromagnetic signals are endogenously generated at different levels of the biological organization and, likely, play an active role in synchronizing internal cell function or local/systemic adaptive response. Consequently, each adaptive response can be described by its specific electromagnetic pattern and, therefore, correlates with a unique and specific electromagnetic signature. A biophysical procedure synchronously integrating the EMITTAS procedure has already been applied for the treatment of articular pain, low-back pain, neck pain and mobility, fluctuating asymmetry, early-stage chronic kidney disease, refractory gynecological infections, minor anxiety and depression disorders. This clinical strategy involves a single treatment, since the EMITTAS procedure allows the patient to continue his/her own personal treatment at home by means of self-administration of the recorded aqueous system. A significant and long-lasting improvement has been reported, showing a potential beneficial use of this biophysical procedure in the management of common illnesses in an efficient, effective and personalized way. Data from recent studies suggest that aqueous systems may play a key role in providing the basis for recording, storing, transferring and retrieving clinically effective quanta of biological information. These features likely enable to trigger local and systemic self-regulation and self-regeneration potential of the organism.

Transient coherence of media under strong phase modulation exploiting electromagnetically induced transparency

NASA Astrophysics Data System (ADS)

Shwa, David; Katz, Nadav

2014-08-01

When quantum systems are shifted faster than their transition and coupling time scales, their susceptibility is dramatically modified. We measure the optical susceptibility of a strongly modulated electromagnetically induced transparency system. Time vs detuning plots for different pump modulation frequencies reveal a transition between an adiabatic regime where a series of smooth pulses are created and a nonadiabatic regime where a strong transient oscillating response is added. Applying a magnetic field lifts the hyperfine level degeneracy, revealing an interference effect between the different magnetic level transients. We explore the dynamics of the magnetic and nonmagnetic cases and discuss their coherent nature. We finally combine the global phase of the transmitted pulses with the transient interference to achieve broadband magnetic sensing without losing the sensitivity of a single electromagnetically induced transparency line.

A Variational Method in Out-of-Equilibrium Physical Systems

PubMed Central

Pinheiro, Mario J.

2013-01-01

We propose a new variational principle for out-of-equilibrium dynamic systems that are fundamentally based on the method of Lagrange multipliers applied to the total entropy of an ensemble of particles. However, we use the fundamental equation of thermodynamics on differential forms, considering U and S as 0-forms. We obtain a set of two first order differential equations that reveal the same formal symplectic structure shared by classical mechanics, fluid mechanics and thermodynamics. From this approach, a topological torsion current emerges of the form , where Aj and ωk denote the components of the vector potential (gravitational and/or electromagnetic) and where ω denotes the angular velocity of the accelerated frame. We derive a special form of the Umov-Poynting theorem for rotating gravito-electromagnetic systems. The variational method is then applied to clarify the working mechanism of particular devices. PMID:24316718

Applied Computational Electromagnetics Society Journal. Volume 13, No. 1

DTIC Science & Technology

1998-03-01

APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL March 1998 Vol. 13 No. 1 ISSN 1054-4887 MBTMBUTION BTATCICEHt 1 ’ | Appcofd for...public rdtooMf DUrtrlbnttoo Unlimited 1 19980709 083 GENERAL PURPOSE AND SCOPE. The Applied Computational Electromagnetics Society Journal...SOCIETY Journal March 1998 Vol. 13 No. 1 ISSN 1054-4887 The ACES Journal is abstracted in INSPEC, in Engineering Index, and in DTIC. The second

Microwave Imaging with Infrared 2-D Lock-in Amplifier

NASA Astrophysics Data System (ADS)

Chiyo, Noritaka; Arai, Mizuki; Tanaka, Yasuhiro; Nishikata, Atsuhiro; Maeno, Takashi

We have developed a 3-D electromagnetic field measurement system using 2-D lock-in amplifier. This system uses an amplitude modulated electromagnetic wave source to heat a resistive screen. A very small change of temperature on a screen illuminated with the modulated electromagnetic wave is measured using an infrared thermograph camera. In this paper, we attempted to apply our system to microwave imaging. By placing conductor patches in front of the resistive screen and illuminating with microwave, the shape of each conductor was clearly observed as the temperature difference image of the screen. In this way, the conductor pattern inside the non-contact type IC card could be visualized. Moreover, we could observe the temperature difference image reflecting the shape of a Konnyaku (a gelatinous food made from devil's-tonge starch) or a dried fishbone, both as non-conducting material resembling human body. These results proved that our method is applicable to microwave see-through imaging.

Active magnetic bearings used as exciters for rolling element bearing outer race defect diagnosis.

PubMed

Xu, Yuanping; Di, Long; Zhou, Jin; Jin, Chaowu; Guo, Qintao

2016-03-01

The active health monitoring of rotordynamic systems in the presence of bearing outer race defect is considered in this paper. The shaft is assumed to be supported by conventional mechanical bearings and an active magnetic bearing (AMB) is used in the mid of the shaft location as an exciter to apply electromagnetic force to the system. We investigate a nonlinear bearing-pedestal system model with the outer race defect under the electromagnetic force. The nonlinear differential equations are integrated using the fourth-order Runge-Kutta algorithm. The simulation and experimental results show that the characteristic signal of outer race incipient defect is significantly amplified under the electromagnetic force through the AMBs, which is helpful to improve the diagnosis accuracy of rolling element bearing׳s incipient outer race defect. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Research on EME of real-time monitoring system

NASA Astrophysics Data System (ADS)

Meng, Ke; Guo, Jiang; Chai, Wei; Wu, Hongyan

2018-01-01

With the increase of the number of substations, the precision of electromagnetic environment parameters is higher. At present, there are many defects in the electromagnetic environment measuring system, such as the nonstandard data and the difficult reutilization. And many circuits with self-scale are controlled by switch, it has a great impact on the switching time and the service life of the device. A method of magnetic field range smooth switching is provided in this paper which is based on the magneto resistivity and the control of MCU, applying this method to the monitoring system which has functions of distributed data, real time data display, data storage and unified management etc.

Reflection Coefficients.

ERIC Educational Resources Information Center

Greenslade, Thomas B., Jr.

1994-01-01

Discusses and provides an example of reflectivity approximation to determine whether reflection will occur. Provides a method to show thin-film interference on a projection screen. Also applies the reflectivity concepts to electromagnetic wave systems. (MVL)

Chip-based droplet sorting

DOEpatents

Beer, Neil Reginald; Lee, Abraham; Hatch, Andrew

2014-07-01

A non-contact system for sorting monodisperse water-in-oil emulsion droplets in a microfluidic device based on the droplet's contents and their interaction with an applied electromagnetic field or by identification and sorting.

Goaf water detection using the grounded electrical source airborne transient electromagnetic system

NASA Astrophysics Data System (ADS)

Li, D.; Ji, Y.; Guan, S.; Wu, Y.; Wang, A.

2017-12-01

To detect the geoelectric characteristic of goaf water, the grounded electrical source airborne transient electromagnetic (GREATEM) system (developed by Jilin University, China) is applied to the goaf water detection since its advantages of considerable prospecting depth, lateral resolution and detection efficiency. For the test of GREATEM system in goaf water detection, an experimental survey was conducted at Qinshui coal mine (Shanxi province, China). After data acquisition, noise reduction and inversion, the resistivity profiles of survey area is presented. The results highly agree the investigation information provided by Shanxi Coal Geology Geophysical Surveying Exploration Institute (China), conforming that the GREATEM system is an effective technique for resistivity detection of goaf water.

Difficulties in applying numerical simulations to an evaluation of occupational hazards caused by electromagnetic fields

PubMed Central

Zradziński, Patryk

2015-01-01

Due to the various physical mechanisms of interaction between a worker's body and the electromagnetic field at various frequencies, the principles of numerical simulations have been discussed for three areas of worker exposure: to low frequency magnetic field, to low and intermediate frequency electric field and to radiofrequency electromagnetic field. This paper presents the identified difficulties in applying numerical simulations to evaluate physical estimators of direct and indirect effects of exposure to electromagnetic fields at various frequencies. Exposure of workers operating a plastic sealer have been taken as an example scenario of electromagnetic field exposure at the workplace for discussion of those difficulties in applying numerical simulations. The following difficulties in reliable numerical simulations of workers’ exposure to the electromagnetic field have been considered: workers’ body models (posture, dimensions, shape and grounding conditions), working environment models (objects most influencing electromagnetic field distribution) and an analysis of parameters for which exposure limitations are specified in international guidelines and standards. PMID:26323781

An Attachable Electromagnetic Energy Harvester Driven Wireless Sensing System Demonstrating Milling-Processes and Cutter-Wear/Breakage-Condition Monitoring.

PubMed

Chung, Tien-Kan; Yeh, Po-Chen; Lee, Hao; Lin, Cheng-Mao; Tseng, Chia-Yung; Lo, Wen-Tuan; Wang, Chieh-Min; Wang, Wen-Chin; Tu, Chi-Jen; Tasi, Pei-Yuan; Chang, Jui-Wen

2016-02-23

An attachable electromagnetic-energy-harvester driven wireless vibration-sensing system for monitoring milling-processes and cutter-wear/breakage-conditions is demonstrated. The system includes an electromagnetic energy harvester, three single-axis Micro Electro-Mechanical Systems (MEMS) accelerometers, a wireless chip module, and corresponding circuits. The harvester consisting of magnets with a coil uses electromagnetic induction to harness mechanical energy produced by the rotating spindle in milling processes and consequently convert the harnessed energy to electrical output. The electrical output is rectified by the rectification circuit to power the accelerometers and wireless chip module. The harvester, circuits, accelerometer, and wireless chip are integrated as an energy-harvester driven wireless vibration-sensing system. Therefore, this completes a self-powered wireless vibration sensing system. For system testing, a numerical-controlled machining tool with various milling processes is used. According to the test results, the system is fully self-powered and able to successfully sense vibration in the milling processes. Furthermore, by analyzing the vibration signals (i.e., through analyzing the electrical outputs of the accelerometers), criteria are successfully established for the system for real-time accurate simulations of the milling-processes and cutter-conditions (such as cutter-wear conditions and cutter-breaking occurrence). Due to these results, our approach can be applied to most milling and other machining machines in factories to realize more smart machining technologies.

An Attachable Electromagnetic Energy Harvester Driven Wireless Sensing System Demonstrating Milling-Processes and Cutter-Wear/Breakage-Condition Monitoring

PubMed Central

Chung, Tien-Kan; Yeh, Po-Chen; Lee, Hao; Lin, Cheng-Mao; Tseng, Chia-Yung; Lo, Wen-Tuan; Wang, Chieh-Min; Wang, Wen-Chin; Tu, Chi-Jen; Tasi, Pei-Yuan; Chang, Jui-Wen

2016-01-01

An attachable electromagnetic-energy-harvester driven wireless vibration-sensing system for monitoring milling-processes and cutter-wear/breakage-conditions is demonstrated. The system includes an electromagnetic energy harvester, three single-axis Micro Electro-Mechanical Systems (MEMS) accelerometers, a wireless chip module, and corresponding circuits. The harvester consisting of magnets with a coil uses electromagnetic induction to harness mechanical energy produced by the rotating spindle in milling processes and consequently convert the harnessed energy to electrical output. The electrical output is rectified by the rectification circuit to power the accelerometers and wireless chip module. The harvester, circuits, accelerometer, and wireless chip are integrated as an energy-harvester driven wireless vibration-sensing system. Therefore, this completes a self-powered wireless vibration sensing system. For system testing, a numerical-controlled machining tool with various milling processes is used. According to the test results, the system is fully self-powered and able to successfully sense vibration in the milling processes. Furthermore, by analyzing the vibration signals (i.e., through analyzing the electrical outputs of the accelerometers), criteria are successfully established for the system for real-time accurate simulations of the milling-processes and cutter-conditions (such as cutter-wear conditions and cutter-breaking occurrence). Due to these results, our approach can be applied to most milling and other machining machines in factories to realize more smart machining technologies. PMID:26907297

Theoretical study on the ultra-narrow bandwidth tunable atomic filter with electromagnetically induced transparency

NASA Astrophysics Data System (ADS)

Liu, Yang; Li, Shu-qing; Feng, Zhong-ying; Liu, Xiao-fei; Gao, Jin-yue

2016-12-01

To obtain the weak signal light detection from the high background noise, we present a theoretical study on the ultra-narrow bandwidth tunable atomic filter with electromagnetically induced transparency. In a three-level Λ -type atomic system in the rubidium D1 line, the bandwidth of the EIT atomic filter is narrowed to ~6.5 \\text{MHz} . And the single peak transmission of the filter can be up to 86% . Moreover, the transmission wavelength can be tuned by changing the coupling light frequency. This theoretical scheme can also be applied to other alkali atomic systems.

Applied Computational Electromagnetics Society Journal, volume 9, number 1, March 1994

NASA Astrophysics Data System (ADS)

1994-03-01

The partial contents of this document include the following: On the Use of Bivariate Spline Interpolation of Slot Data in the Design of Slotted Waveguide Arrays; A Technique for Determining Non-Integer Eigenvalues for Solutions of Ordinary Differential Equations; Antenna Modeling and Characterization of a VLF Airborne Dual Trailing Wire Antenna System; Electromagnetic Scattering from Two-Dimensional Composite Objects; and Use of a Stealth Boundary with Finite Difference Frequency Domain Simulations of Simple Antenna Problems.

Bianisotropic metamaterial

DOEpatents

El-Kady, Ihab F.; Reinke, Charles M.

2017-07-18

The topology of the elements of a metamaterial can be engineered from its desired electromagnetic constitutive tensor using an inverse group theory method. Therefore, given a desired electromagnetic response and a generic metamaterial elemental design, group theory is applied to predict the various ways that the element can be arranged in three dimensions to produce the desired functionality. An optimizer can then be applied to an electromagnetic modeling tool to fine tune the values of the electromagnetic properties of the resulting metamaterial topology.

Doomed to Repeat It How the United States Air Force Can Apply History via Counterinsurgency Lessons Learned to Meet Anti-Access/Area Denial Challenges

DTIC Science & Technology

2012-08-01

technology used in the COIN fight are not readily transferable to conflicts against enemies using A2/AD tactics, such as heavy electromagnetic attack...particularly when matched against a technology advanced enemy. Technologies unsuitable for an opposed electromagnetic spectrum are unsurvivable...increased numbers of weapons systems such as the MQ-1, MQ-9, and MC-12. Additionally, open-ended deployments of ISR assets such as the RC-135 RIVET

Treatment of Diabetic Foot Ulcers through Systemic Effects of Extremely Low Frequency Electromagnetic Fields

NASA Astrophysics Data System (ADS)

Trejo-Núñez, A. D.; Pérez-Chávez, F.; García-Sánchez, C.; Serrano-Luna, G.; Cañendo-Dorantes, L.

2008-08-01

This study was designed to, investigate the healing effects of extremely low frequency electromagnetic fields (ELF-EMF) on diabetic foot ulcers and test two different exposure systems aimed at reducing the ELF-EMF exposure time of patients. In the first system the ELF-EMF were applied to the arm where only 3% of the total blood volume/min circulates at any given time. In the second system the ELF-EMF were applied to the thorax where more than 100% of the total blood volume/minute circulates at any given time. Twenty-six diabetic patients, with superficial neuropathic ulcers unresponsive to medical treatment were included in this preliminary report. In the first group (17 patients), the arm was exposed two hours twice a week to a extremely low frequency electromagnetic field of 0.45-0.9 mTrms, 120 Hz generated inside a solenoid coil of 10.1 cm by 20.5 cm long. In the second group the thorax of 7 patients was exposed 25 minutes twice a week to an electromagnetic field of 0.4-0.85 mTrms, 120 Hz generated in the center of a squared quasi-Helmholtz coil 52 cm by side. One patient was assigned to a placebo configuration of each exposure system with identical appearance as the active equipment but without magnetic field. Patients with deep ulcers, infected ulcers, cancer, or auto-immune disease were excluded. These preliminary results showed that the two exposure systems accelerate the healing process of neuropathic ulcers. Complete healing of the ulcer had a median duration of 90 days in both exposure systems. Therefore thorax exposure where more blood is exposed to ELF-EMF per unit of time was able to reduce 4.8 times the patient treatment time. In those patients assigned to the placebo equipment no healing effects were observed. This study will continue with a parallel, double blind placebo controlled protocol.

Propulsive Efficiencies of Magnetohydrodynamic Submerged Vehicular Propulsors

DTIC Science & Technology

1990-04-01

TERMS (Con’we on mrae . neoaay and kWerty by back nLt.) FIELD GROUP SUB-GROUP Magnetohydrodynamic propulsion, marine propulsion, seawater pump ...propelling a vehicular structure by a seawater elec- tromagnetic pump . This propulsion system can be applied to a surface ship or a submerged vehicle; however...structure by a seawater electromagnetic pump . This propulsion system can be applied to a surface ship or a submerged vehicle; however, in this work only

Electromagnetic driving units for complex microrobotic systems

NASA Astrophysics Data System (ADS)

Michel, Frank; Ehrfeld, Wolfgang; Berg, Udo; Degen, Reinhard; Schmitz, Felix

1998-10-01

Electromagnetic actuators play an important role in macroscopic robotic systems. In combination with motion transformers, like reducing gear units, angular gears or spindle-screw drives, electromagnetic motors in large product lines ensure the rotational or linear motion of robot driving units and grippers while electromagnets drive valves or part conveyors. In this paper micro actuators and miniaturized motion transformers are introduced which allow a similar development in microrobotics. An electromagnetic motor and a planetary gear box, both with a diameter of 1.9 mm, are already commercially available from the cooperation partner of IMM, the company Dr. Fritz Faulhaber GmbH in Schonaich, Germany. In addition, a motor with a diameter of 2.4 mm is in development. The motors successfully drive an angular gear and a belt drive. A linear stage with a motion range of 7 mm and an overall size as small as 5 X 3.5 X 24 mm3 has been realized involving the motor, a stationary spur gear with zero backlash and a spindle-screw drive. By the use of these commercially available elements complex microrobots can be built up cost-efficiently and rapidly. Furthermore, a batch process has been developed to produce the coils of micro actuator arrays using lithographic techniques with SU-8 resin. In applying these components, the modular construction of complex microrobotic systems becomes feasible.

Thunderstorm monitoring and lightning warning, operational applications of the Safir system

NASA Technical Reports Server (NTRS)

Richard, Philippe

1991-01-01

During the past years a new range of studies have been opened by the application of electromagnetic localization techniques to the field of thunderstorm remote sensing. VHF localization techniques were used in particular for the analysis of lightning discharges and gave access to time resolved 3-D images of lightning discharges within thunderclouds. Detection and localization techniques developed have been applied to the design of the SAFIR system. This development's main objective was the design of an operational system capable of assessing and warning in real time for lightning hazards and potential thunderstorm hazards. The SAFIR system main detection technique is the long range interferometric localization of thunderstorm electromagnetic activity; the system performs the localization of intracloud and cloud to ground lightning discharges and the analysis of the characteristics of the activity.

Design and analysis of magneto rheological fluid brake for an all terrain vehicle

NASA Astrophysics Data System (ADS)

George, Luckachan K.; Tamilarasan, N.; Thirumalini, S.

2018-02-01

This work presents an optimised design for a magneto rheological fluid brake for all terrain vehicles. The actuator consists of a disk which is immersed in the magneto rheological fluid surrounded by an electromagnet. The braking torque is controlled by varying the DC current applied to the electromagnet. In the presence of a magnetic field, the magneto rheological fluid particle aligns in a chain like structure, thus increasing the viscosity. The shear stress generated causes friction in the surfaces of the rotating disk. Electromagnetic analysis of the proposed system is carried out using finite element based COMSOL multi-physics software and the amount of magnetic field generated is calculated with the help of COMSOL. The geometry is optimised and performance of the system in terms of braking torque is carried out. Proposed design reveals better performance in terms of braking torque from the existing literature.

A New Intraoperative Real-time Monitoring System for Reconstructive Middle Ear Surgery: An Experimental and Clinical Feasibility Study.

PubMed

Zahnert, Thomas; Metasch, Marie-Luise; Seidler, Hannes; Bornitz, Matthias; Lasurashvili, Nicoloz; Neudert, Marcus

2016-12-01

Electromagnetical excitation of ossicular vibration is suitable for middle ear transmission measurements in the experimental and clinical setting. Thereby, it can be used as a real-time monitoring system for quality control in ossiculoplasty. Positioning and coupling of middle ear prosthesis are a precondition for good postoperative hearing results, but at the same time completely dependent upon the surgeon's subjective judgment during surgery. We evaluated an electromagnetically driven measurement system that enables for in vitro and in vivo transmission measurements and thus can be used as a real-time monitoring tool in ossicular reconstruction. For electromagnetical excitation a magnet was placed on the umbo of the malleus handle and driven by a magnetic field. The induced stapes displacement was picked up by laser Doppler vibrometry on the footplate. Measurements were performed on the intact ossicular chain in five cadaveric temporal bones and during five cochlear implant surgeries. Additionally, two ossiculoplasties were performed under real-time transmission feedback with the monitoring system. Experimentally, the equivalent sound pressure level of the electromagnetic excitation was about 70 to 80 dB which is 10 to 20 dB less than the acoustic stimulation. In the intraoperative setup the generated stapes displacements were about 5 to 20 dB smaller compared with the temporal bone experiments. Applied as real-time feedback system, an improvement in the middle ear transfer function of 4.5 dB in total and 20 dB in partial ossicular reconstruction were achieved. The electromagnetical excitation and measurement system is comparable to the gold standard with acoustical stimulation in both, the experimental setup in temporal bones as well as in vivo. The technical feasibility of the electromagnetical excitation method has been proven and it is shown that it can be used as a real-time monitoring system for ossiculoplasty in the operation room.

Preliminary Study of 2-D Time Domain Electromagnetic (TDEM) Modeling to Analyze Subsurface Resistivity Distribution and its Application to the Geothermal Systems

NASA Astrophysics Data System (ADS)

Aji Hapsoro, Cahyo; Purqon, Acep; Srigutomo, Wahyu

2017-07-01

2-D Time Domain Electromagnetic (TDEM) has been successfully conducted to illustrate the value of Electric field distribution under the Earth surface. Electric field compared by magnetic field is used to analyze resistivity and resistivity is one of physical properties which very important to determine the reservoir potential area of geothermal systems as one of renewable energy. In this modeling we used Time Domain Electromagnetic method because it can solve EM field interaction problem with complex geometry and to analyze transient problems. TDEM methods used to model the value of electric and magnetic fields as a function of the time combined with the function of distance and depth. The result of this modeling is Electric field intensity value which is capable to describe the structure of the Earth’s subsurface. The result of this modeling can be applied to describe the Earths subsurface resistivity values to determine the reservoir potential of geothermal systems.

Electromagnetic packable technology (EMPACT) for detection and characterization of ordnance in post-conflict areas

NASA Astrophysics Data System (ADS)

Schultz, Gregory; Miller, Jonathan; Keranen, Joe

2013-06-01

Land reclamation efforts in post-conflict regions are often hampered by the presence of Unexploded Ordnance (UXO) or other Explosive Remnants of War (ERW). Surface geophysical methods, such as Electromagnetic Induction (EMI) and magnetometry, are typically applied to screen rehabilitation areas for UXO prior to excavation; however, the prevalence of innocuous magnetic clutter related to indigenous scrap, fragmentation, or geology can severely impede the progress and efficiency of these remediation efforts. Additionally, the variability in surface conditions and local topography necessitates the development of sensor technologies that can be applied to a range of sites including those that prohibit the use of vehicle-mounted or large array systems. We present a man-portable EMI sensor known as the Electromagnetic Packable Technology (EMPACT) system that features a multi-axis sensor configuration in a compact form factor. The system is designed for operation in challenging site conditions and can be used in low ground-standoff modes to detect small and low-metal content objects. The EMPACT acquires high spatial density, multi-axis data that enable high resolution of small objects. This high density data can also be used to provide characterization of target physical features, such as size, material content, and shape. We summarize the development of this system for humanitarian demining operations and present results from preliminary system evaluations against a range of target types. Specifically, we assess the general detection capabilities of the EMPACT system and we evaluate the potential for target classification based on analysis of data and target model features.

Monitoring of breathing motion in image-guided PBS proton therapy: comparative analysis of optical and electromagnetic technologies.

PubMed

Fattori, Giovanni; Safai, Sairos; Carmona, Pablo Fernández; Peroni, Marta; Perrin, Rosalind; Weber, Damien Charles; Lomax, Antony John

2017-03-31

Motion monitoring is essential when treating non-static tumours with pencil beam scanned protons. 4D medical imaging typically relies on the detected body surface displacement, considered as a surrogate of the patient's anatomical changes, a concept similarly applied by most motion mitigation techniques. In this study, we investigate benefits and pitfalls of optical and electromagnetic tracking, key technologies for non-invasive surface motion monitoring, in the specific environment of image-guided, gantry-based proton therapy. Polaris SPECTRA optical tracking system and the Aurora V3 electromagnetic tracking system from Northern Digital Inc. (NDI, Waterloo, CA) have been compared both technically, by measuring tracking errors and system latencies under laboratory conditions, and clinically, by assessing their practicalities and sensitivities when used with imaging devices and PBS treatment gantries. Additionally, we investigated the impact of using different surrogate signals, from different systems, on the reconstructed 4D CT images. Even though in controlled laboratory conditions both technologies allow for the localization of static fiducials with sub-millimetre jitter and low latency (31.6 ± 1 msec worst case), significant dynamic and environmental distortions limit the potential of the electromagnetic approach in a clinical setting. The measurement error in case of close proximity to a CT scanner is up to 10.5 mm and precludes its use for the monitoring of respiratory motion during 4DCT acquisitions. Similarly, the motion of the treatment gantry distorts up to 22 mm the tracking result. Despite the line of sight requirement, the optical solution offers the best potential, being the most robust against environmental factors and providing the highest spatial accuracy. The significant difference in the temporal location of the reconstructed phase points is used to speculate on the need to apply the same monitoring system for imaging and treatment to ensure the consistency of detected phases.

Integrated interpretation of overlapping AEM datasets achieved through standardisation

NASA Astrophysics Data System (ADS)

Sørensen, Camilla C.; Munday, Tim; Heinson, Graham

2015-12-01

Numerous airborne electromagnetic surveys have been acquired in Australia using a variety of systems. It is not uncommon to find two or more surveys covering the same ground, but acquired using different systems and at different times. Being able to combine overlapping datasets and get a spatially coherent resistivity-depth image of the ground can assist geological interpretation, particularly when more subtle geophysical responses are important. Combining resistivity-depth models obtained from the inversion of airborne electromagnetic (AEM) data can be challenging, given differences in system configuration, geometry, flying height and preservation or monitoring of system acquisition parameters such as waveform. In this study, we define and apply an approach to overlapping AEM surveys, acquired by fixed wing and helicopter time domain electromagnetic (EM) systems flown in the vicinity of the Goulds Dam uranium deposit in the Frome Embayment, South Australia, with the aim of mapping the basement geometry and the extent of the Billeroo palaeovalley. Ground EM soundings were used to standardise the AEM data, although results indicated that only data from the REPTEM system needed to be corrected to bring the two surveys into agreement and to achieve coherent spatial resistivity-depth intervals.

Quantum kinetic theory of the filamentation instability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bret, A.; Haas, F.

2011-07-15

The quantum electromagnetic dielectric tensor for a multi-species plasma is re-derived from the gauge-invariant Wigner-Maxwell system and presented under a form very similar to the classical one. The resulting expression is then applied to a quantum kinetic theory of the electromagnetic filamentation instability. Comparison is made with the quantum fluid theory including a Bohm pressure term and with the cold classical plasma result. A number of analytical expressions are derived for the cutoff wave vector, the largest growth rate, and the most unstable wave vector.

Unconditionally stable WLP-FDTD method for the modeling of electromagnetic wave propagation in gyrotropic materials.

PubMed

Li, Zheng-Wei; Xi, Xiao-Li; Zhang, Jin-Sheng; Liu, Jiang-fan

2015-12-14

The unconditional stable finite-difference time-domain (FDTD) method based on field expansion with weighted Laguerre polynomials (WLPs) is applied to model electromagnetic wave propagation in gyrotropic materials. The conventional Yee cell is modified to have the tightly coupled current density components located at the same spatial position. The perfectly matched layer (PML) is formulated in a stretched-coordinate (SC) system with the complex-frequency-shifted (CFS) factor to achieve good absorption performance. Numerical examples are shown to validate the accuracy and efficiency of the proposed method.

40 CFR 60.721 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... include conductive sensitizers or electromagnetic interference/radio frequency interference shielding.... Electromagnetic interference/radio frequency interference (EMI/RFI) shielding coating means a conductive coating... coating is applied, not including conductive sensitizers or electromagnetic interference/radio frequency...

40 CFR 60.721 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... include conductive sensitizers or electromagnetic interference/radio frequency interference shielding.... Electromagnetic interference/radio frequency interference (EMI/RFI) shielding coating means a conductive coating... coating is applied, not including conductive sensitizers or electromagnetic interference/radio frequency...

40 CFR 60.721 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... include conductive sensitizers or electromagnetic interference/radio frequency interference shielding.... Electromagnetic interference/radio frequency interference (EMI/RFI) shielding coating means a conductive coating... coating is applied, not including conductive sensitizers or electromagnetic interference/radio frequency...

40 CFR 60.721 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... include conductive sensitizers or electromagnetic interference/radio frequency interference shielding.... Electromagnetic interference/radio frequency interference (EMI/RFI) shielding coating means a conductive coating... coating is applied, not including conductive sensitizers or electromagnetic interference/radio frequency...

40 CFR 60.721 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... include conductive sensitizers or electromagnetic interference/radio frequency interference shielding.... Electromagnetic interference/radio frequency interference (EMI/RFI) shielding coating means a conductive coating... coating is applied, not including conductive sensitizers or electromagnetic interference/radio frequency...

Electromagnetic interference modeling and suppression techniques in variable-frequency drive systems

NASA Astrophysics Data System (ADS)

Yang, Le; Wang, Shuo; Feng, Jianghua

2017-11-01

Electromagnetic interference (EMI) causes electromechanical damage to the motors and degrades the reliability of variable-frequency drive (VFD) systems. Unlike fundamental frequency components in motor drive systems, high-frequency EMI noise, coupled with the parasitic parameters of the trough system, are difficult to analyze and reduce. In this article, EMI modeling techniques for different function units in a VFD system, including induction motors, motor bearings, and rectifierinverters, are reviewed and evaluated in terms of applied frequency range, model parameterization, and model accuracy. The EMI models for the motors are categorized based on modeling techniques and model topologies. Motor bearing and shaft models are also reviewed, and techniques that are used to eliminate bearing current are evaluated. Modeling techniques for conventional rectifierinverter systems are also summarized. EMI noise suppression techniques, including passive filter, Wheatstone bridge balance, active filter, and optimized modulation, are reviewed and compared based on the VFD system models.

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

NASA Astrophysics Data System (ADS)

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.

Scalable High Performance Computing: Direct and Large-Eddy Turbulent Flow Simulations Using Massively Parallel Computers

NASA Technical Reports Server (NTRS)

Morgan, Philip E.

2004-01-01

This final report contains reports of research related to the tasks "Scalable High Performance Computing: Direct and Lark-Eddy Turbulent FLow Simulations Using Massively Parallel Computers" and "Devleop High-Performance Time-Domain Computational Electromagnetics Capability for RCS Prediction, Wave Propagation in Dispersive Media, and Dual-Use Applications. The discussion of Scalable High Performance Computing reports on three objectives: validate, access scalability, and apply two parallel flow solvers for three-dimensional Navier-Stokes flows; develop and validate a high-order parallel solver for Direct Numerical Simulations (DNS) and Large Eddy Simulation (LES) problems; and Investigate and develop a high-order Reynolds averaged Navier-Stokes turbulence model. The discussion of High-Performance Time-Domain Computational Electromagnetics reports on five objectives: enhancement of an electromagnetics code (CHARGE) to be able to effectively model antenna problems; utilize lessons learned in high-order/spectral solution of swirling 3D jets to apply to solving electromagnetics project; transition a high-order fluids code, FDL3DI, to be able to solve Maxwell's Equations using compact-differencing; develop and demonstrate improved radiation absorbing boundary conditions for high-order CEM; and extend high-order CEM solver to address variable material properties. The report also contains a review of work done by the systems engineer.

Bio-soliton model that predicts non-thermal electromagnetic frequency bands, that either stabilize or destabilize living cells.

PubMed

Geesink, J H; Meijer, D K F

2017-01-01

Solitons, as self-reinforcing solitary waves, interact with complex biological phenomena such as cellular self-organization. A soliton model is able to describe a spectrum of electromagnetism modalities that can be applied to understand the physical principles of biological effects in living cells, as caused by endogenous and exogenous electromagnetic fields and is compatible with quantum coherence. A bio-soliton model is proposed, that enables to predict which eigen-frequencies of non-thermal electromagnetic waves are life-sustaining and which are, in contrast, detrimental for living cells. The particular effects are exerted by a range of electromagnetic wave eigen-frequencies of one-tenth of a Hertz till Peta Hertz that show a pattern of 12 bands, and can be positioned on an acoustic reference frequency scale. The model was substantiated by a meta-analysis of 240 published articles of biological electromagnetic experiments, in which a spectrum of non-thermal electromagnetic waves were exposed to living cells and intact organisms. These data support the concept of coherent quantized electromagnetic states in living organisms and the theories of Fröhlich, Davydov and Pang. It is envisioned that a rational control of shape by soliton-waves and related to a morphogenetic field and parametric resonance provides positional information and cues to regulate organism-wide systems properties like anatomy, control of reproduction and repair.

Observation of unidirectional backscattering-immune topological electromagnetic states.

PubMed

Wang, Zheng; Chong, Yidong; Joannopoulos, J D; Soljacić, Marin

2009-10-08

One of the most striking phenomena in condensed-matter physics is the quantum Hall effect, which arises in two-dimensional electron systems subject to a large magnetic field applied perpendicular to the plane in which the electrons reside. In such circumstances, current is carried by electrons along the edges of the system, in so-called chiral edge states (CESs). These are states that, as a consequence of nontrivial topological properties of the bulk electronic band structure, have a unique directionality and are robust against scattering from disorder. Recently, it was theoretically predicted that electromagnetic analogues of such electronic edge states could be observed in photonic crystals, which are materials having refractive-index variations with a periodicity comparable to the wavelength of the light passing through them. Here we report the experimental realization and observation of such electromagnetic CESs in a magneto-optical photonic crystal fabricated in the microwave regime. We demonstrate that, like their electronic counterparts, electromagnetic CESs can travel in only one direction and are very robust against scattering from disorder; we find that even large metallic scatterers placed in the path of the propagating edge modes do not induce reflections. These modes may enable the production of new classes of electromagnetic device and experiments that would be impossible using conventional reciprocal photonic states alone. Furthermore, our experimental demonstration and study of photonic CESs provides strong support for the generalization and application of topological band theories to classical and bosonic systems, and may lead to the realization and observation of topological phenomena in a generally much more controlled and customizable fashion than is typically possible with electronic systems.

A multiscale quantum mechanics/electromagnetics method for device simulations.

PubMed

Yam, ChiYung; Meng, Lingyi; Zhang, Yu; Chen, GuanHua

2015-04-07

Multiscale modeling has become a popular tool for research applying to different areas including materials science, microelectronics, biology, chemistry, etc. In this tutorial review, we describe a newly developed multiscale computational method, incorporating quantum mechanics into electronic device modeling with the electromagnetic environment included through classical electrodynamics. In the quantum mechanics/electromagnetics (QM/EM) method, the regions of the system where active electron scattering processes take place are treated quantum mechanically, while the surroundings are described by Maxwell's equations and a semiclassical drift-diffusion model. The QM model and the EM model are solved, respectively, in different regions of the system in a self-consistent manner. Potential distributions and current densities at the interface between QM and EM regions are employed as the boundary conditions for the quantum mechanical and electromagnetic simulations, respectively. The method is illustrated in the simulation of several realistic systems. In the case of junctionless field-effect transistors, transfer characteristics are obtained and a good agreement between experiments and simulations is achieved. Optical properties of a tandem photovoltaic cell are studied and the simulations demonstrate that multiple QM regions are coupled through the classical EM model. Finally, the study of a carbon nanotube-based molecular device shows the accuracy and efficiency of the QM/EM method.

Scaling and characterisation of a 2-DoF velocity amplified electromagnetic vibration energy harvester

NASA Astrophysics Data System (ADS)

O’Donoghue, D.; Frizzell, R.; Punch, J.

2018-07-01

Vibration energy harvesters (VEHs) offer an alternative to batteries for the autonomous operation of low-power electronics. Understanding the influence of scaling on VEHs is of great importance in the design of reduced scale harvesters. The nonlinear harvesters investigated here employ velocity amplification, a technique used to increase velocity through impacts, to improve the power output of multiple-degree-of-freedom VEHs, compared to linear resonators. Such harvesters, employing electromagnetic induction, are referred to as velocity amplified electromagnetic generators (VAEGs), with gains in power achieved by increasing the relative velocity between the magnet and coil in the transducer. The influence of scaling on a nonlinear 2-DoF VAEG is presented. Due to the increased complexity of VAEGs, compared to linear systems, linear scaling theory cannot be directly applied to VAEGs. Therefore, a detailed nonlinear scaling method is utilised. Experimental and numerical methods are employed. This nonlinear scaling method can be used for analysing the scaling behaviour of all nonlinear electromagnetic VEHs. It is demonstrated that the electromagnetic coupling coefficient degrades more rapidly with scale for systems with larger displacement amplitudes, meaning that systems operating at low frequencies will scale poorly compared to those operating at higher frequencies. The load power of the 2-DoF VAEG is predicted to scale as {P}L\\propto {s}5.51 (s = volume1/3), suggesting that achieving high power densities in a VAEG with low device volume is extremely challenging.

Electromagnetic methods for mapping freshwater lenses on Micronesian atoll islands

USGS Publications Warehouse

Anthony, S.S.

1992-01-01

The overall shape of freshwater lenses can be determined by applying electromagnetic methods and inverse layered-earth modeling to the mapping of atoll island freshwater lenses. Conductivity profiles were run across the width of the inhabited islands at Mwoakilloa, Pingelap, and Sapwuahfik atolls of the Pohnpei State, Federated States of Micronesia using a dual-loop, frequency-domain, electromagnetic profiling system. Six values of apparent conductivity were recorded at each sounding station and were used to interpret layer conductivities and/or thicknesses. A three-layer model that includes the unsaturated, freshwater, and saltwater zones was used to simulate apparent-conductivity data measured in the field. Interpreted results were compared with chloride-concentration data from monitoring wells and indicate that the interface between freshwater and saltwater layers, defined from electromagnetic data, is located in the upper part of the transition zone, where the chloride-concentration profile shows a rapid increase with depth. The electromagnetic method can be used to interpret the thickness of the freshwater between monitoring wells, but can not be used to interpret the thickness of freshwater from monitoring wells to the margin of an island. ?? 1992.

Global electromagnetic induction in the moon and planets. [poloidal eddy current transient response

NASA Technical Reports Server (NTRS)

Dyal, P.; Parkin, C. W.

1973-01-01

Experiments and analyses concerning electromagnetic induction in the moon and other extraterrestrial bodies are summarized. The theory of classical electromagnetic induction in a sphere is first considered, and this treatment is extended to the case of the moon, where poloidal eddy-current response has been found experimentally to dominate other induction modes. Analysis of lunar poloidal induction yields lunar internal electrical conductivity and temperature profiles. Two poloidal-induction analytical techniques are discussed: a transient-response method applied to time-series magnetometer data, and a harmonic-analysis method applied to data numerically Fourier-transformed to the frequency domain, with emphasis on the former technique. Attention is given to complicating effects of the solar wind interaction with both induced poloidal fields and remanent steady fields. The static magnetization field induction mode is described, from which are calculated bulk magnetic permeability profiles. Magnetic field measurements obtained from the moon and from fly-bys of Venus and Mars are studied to determine the feasibility of extending theoretical and experimental induction techniques to other bodies in the solar system.

Inhibition of electron thermal conduction by electromagnetic instabilities. [in stellar coronas

NASA Technical Reports Server (NTRS)

Levinson, Amir; Eichler, David

1992-01-01

Heat flux inhibition by electromagnetic instabilities in a hot magnetized plasma is investigated. Low-frequency electromagnetic waves become unstable due to anisotropy of the electron distribution function. The chaotic magnetic field thus generated scatters the electrons with a specific effective mean free path. Saturation of the instability due to wave-wave interaction, nonlinear scattering, wave propagation, and collisional damping is considered. The effective mean free path is found self-consistently, using a simple model to estimate saturation level and scattering, and is shown to decrease with the temperature gradient length. The results, limited to the assumptions of the model, are applied to astrophysical systems. For some interstellar clouds the instability is found to be important. Collisional damping stabilizes the plasma, and the heat conduction can be dominated by superthermal electrons.

Theoretical investigations of energy harvesting efficiency from structural vibrations using piezoelectric and electromagnetic oscillators.

PubMed

Harne, Ryan L

2012-07-01

Conversion of ambient vibrational energy into electric power has been the impetus of much modern research. The traditional analysis has focused on absolute electrical power output from the harvesting devices and efficiency defined as the convertibility of an infinite resource of vibration excitation into power. This perspective has limited extensibility when applying resonant harvesters to host resonant structures when the inertial influence of the harvester is more significant. Instead, this work pursues a fundamental understanding of the coupled dynamics of a main mass-spring-damper system to which an electromagnetic or piezoelectric mass-spring-damper is attached. The governing equations are derived, a metric of efficiency is presented, and analysis is undertaken. It is found that electromagnetic energy harvesting efficiency and maximum power output is limited by the strength of the coupling such that no split system resonances are induced for a given mass ratio. For piezoelectric harvesters, only the coupling strength and certain design requirements dictate maximum power and efficiency achievable. Since the harvesting circuitry must "follow" the split resonances as the piezoelectric harvesters become more massive, the optimum design of piezoelectric harvesters appears to be more involved than for electromagnetic devices.

Applied Computational Electromagnetics Society Journal, Volume 9, Number 1, March 1994

DTIC Science & Technology

1994-03-01

AD-A7 5 I..... * APPLIED COMPUrA77ONAL ELECTROMAGNETICS SOCIETY Journal FjLECTE TI S*...*....March 1994 Vol. 9 No. 1 .... .. .. .ISSN 1054-4887...25.00. REMIT BY: ( 1 ) BANK DRAFTS (MUST BE DRAWN ON U.S. BANK). (2) INTERNATIONAL MONEY ORDER, (3) TRAVELER’S CHECKS IN U.S. DOLLARS, (4) ELECTRONIC...COMPUTATIONAL ELECTROMAGNETICS SOCIETY "Accesion For Joumal NTIS CRAM OTIC TAB Urannounced Justification. March 1994 By ................ Vol. 9 No. 1

Anechoic Chamber test of the Electromagnetic Measurement System ground test unit

NASA Astrophysics Data System (ADS)

Stevenson, L. E.; Scott, L. D.; Oakes, E. T.

1987-04-01

The Electromagnetic Measurement System (EMMS) will acquire data on electromagnetic (EM) environments at key weapon locations on various aircraft certified for nuclear weapons. The high-frequency ground unit of the EMMS consists of an instrumented B61 bomb case that will measure (with current probes) the localized current density resulting from an applied EM field. For this portion of the EMMS, the first system test was performed in the Anechoic Chamber Facility at Sandia National Laboratories, Albuquerque, New Mexico. The EMMS pod was subjected to EM radiation at microwave frequencies of 1, 3, and 10 GHz. At each frequency, the EMMS pod was rotated at many positions relative to the microwave source so that the individual current probes were exposed to a direct line-of-sight illumination. The variations between the measured and calculated electric fields for the current probes with direct illumination by the EM source are within a few db. The results obtained from the anechoic test were better than expected and verify that the high frequency ground portion of the EMMS will accurately measure the EM environments for which it was designed.

Integrated Logistic Support Concerns, Electromagnetic Environmental Effects

DTIC Science & Technology

1991-12-19

AVSCOM Directorate for Engineering, AVSCOM ATTN: AMSAV-ES 4300 Goodfellow Blvd St. Louis, MO 63120-1798 OGDEN/ERC Government Systems, Applied ... Engineering Group, analysis tools for the PM E3 Test Facilities: Picatinny Arsenal Aberdeen Proving Ground White Sands Missile Range TRADOC E3 Awareness

Tethered satellite system control using electromagnetic forces and reaction wheels

NASA Astrophysics Data System (ADS)

Alandi Hallaj, Mohammad Amin; Assadian, Nima

2015-12-01

In this paper a novel non-rotating space tethered configuration is introduced which its relative positions controlled using electromagnetic forces. The attitude dynamics is controlled by three reaction wheels in the body axes. The nonlinear coupled orbital dynamics of a dumbbell tethered satellite formation flight are derived through a constrained Lagrangian approach. These equations are presented in the leader satellite orbital frame. The tether is assumed to be mass-less and straight, and the J2 perturbation is included to the analysis. The forces and the moments of the electromagnetic coils are modeled based on the far-filed model of the magnetic dipoles. A guidance scheme for generating the desired positions as a function of time in Cartesian form is presented. The satellite tethered formation with variable length is controlled utilizing a linear controller. This approach is applied to a specified scenario and it is shown that the nonlinear guidance method and the linear controller can control the nonlinear system of the tethered formation and the results are compared with optimal control approach.

Advanced Electron Holography Applied to Electromagnetic Field Study in Materials Science.

PubMed

Shindo, Daisuke; Tanigaki, Toshiaki; Park, Hyun Soon

2017-07-01

Advances and applications of electron holography to the study of electromagnetic fields in various functional materials are presented. In particular, the development of split-illumination electron holography, which introduces a biprism in the illumination system of a holography electron microscope, enables highly accurate observations of electromagnetic fields and the expansion of the observable area. First, the charge distributions on insulating materials were studied by using split-illumination electron holography and including a mask in the illumination system. Second, the three-dimensional spin configurations of skyrmion lattices in a helimagnet were visualized by using a high-voltage holography electron microscope. Third, the pinning of the magnetic flux lines in a high-temperature superconductor YBa 2 Cu 3 O 7-y was analyzed by combining electron holography and scanning ion microscopy. Finally, the dynamic accumulation and collective motions of electrons around insulating biomaterial surfaces were observed by utilizing the amplitude reconstruction processes of electron holography. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Selective wave-transmitting electromagnetic absorber through composite metasurface

NASA Astrophysics Data System (ADS)

Sun, Zhiwei; Zhao, Junming; Zhu, Bo; Jiang, Tian; Feng, Yijun

2017-11-01

Selective wave-transmitting absorbers which have one or more narrow transmission bands inside a wide absorption band are often demanded in wireless communication and radome applications for reducing the coupling between different systems, improving anti-jamming capability, and reducing antennas' radar cross section. Here we propose a feasible method that utilizing composite of two metasurfaces with different polarization dependent characteristics, one works as electromagnetic polarization rotator and the other as a wideband polarization dependent electromagnetic wave absorber. The polarization rotator produces a cross polarization output in the wave-transmitting band, while preserves the polarization of the incidence outside the band. The metasurface absorber works for certain linear polarization with a much wider absorption band covering the wave-transmitting frequency. When combining these two metasurfaces properly, the whole structure behaves as a wideband absorber with a certain frequency transmission window. The proposal may be applied in radome designs to reduce the radar cross section of antenna or improving the electromagnetic compatibility in communication devices.

Applicability of an electrosurgical device based on electromagnetics in neurosurgery.

PubMed

Gharabaghi, Alireza; Rosahl, Steffen K; Samii, Amir; Feigl, Guenther C; Safavi-Abbasi, Sam; Bundschuh, Otto; Tatagiba, Marcos; Samii, Madjid

2006-07-01

Because of electrical and thermal spread to healthy nervous tissue, the application of electrosurgical tools in neurosurgery has specific limitations. This is true for both bipolar and monopolar devices. These limitations are not inherent to an instrument in which action is based on electromagnetic interaction with human tissue. We evaluated the indications and the clinical applicability of a new radiofrequency electrosurgical unit that works on this biophysical principle. The system was found to be a useful addition for the resection of morphologically tougher tissue with keyhole approaches in which the ultrasound aspirator cannot easily be applied.

Research on Dynamic Torque Measurement of High Speed Rotating Axis Based on Whole Optical Fiber Technique

NASA Astrophysics Data System (ADS)

Ma, H. P.; Jin, Y. Q.; Ha, Y. W.; Liu, L. H.

2006-10-01

Non-contact torque measurement system of fiber grating is proposed in this paper. It is used for the dynamic torque measurement of the rotating axis in the spaceflight servo system. Optical fiber is used as sensing probe with high sensitivity, anti-electromagnetic interference, resistance to high temperature and corrosion. It is suitable to apply in a bad environment. Signals are processed by digital circuit and Single Chip Microcomputer. This project can realize super speed dynamic measurement and it is the first time to apply the project in the spaceflight system.

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

PubMed

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.

Nondestructive evaluation of the preservation state of stone columns in the Hospital Real of Granada

NASA Astrophysics Data System (ADS)

Moreno de Jong van Coevorden, C.; Cobos Sánchez, C.; Rubio Bretones, A.; Fernández Pantoja, M.; García, Salvador G.; Gómez Martín, R.

2012-12-01

This paper describes the results of the employment of two nondestructive evaluation methods for the diagnostic of the preservation state of stone elements. The first method is based on ultrasonic (US) pulses while the second method uses short electromagnetic pulses. Specifically, these methods were applied to some columns, some of them previously restored. These columns are part of the architectonic heritage of the University of Granada, in particular they are located at the patio de la capilla del Hospital Real of Granada. The objective of this work was the application of systems based on US pulses (in transmission mode) and the ground-penetrating radar systems (electromagnetic tomography) in the diagnosis and detection of possible faults in the interior of columns.

Electromagnetic bonding of plastics to aluminum

NASA Technical Reports Server (NTRS)

Sheppard, A. T.; Silbert, L.

1980-01-01

Electromagnetic curing is used to bond strain gage to aluminum tensile bar. Electromagnetic energy heats only plastic/metal interface by means of skin effect, preventing degradation of heat-treated aluminum. Process can be easily applied to other metals joined by high-temperature-curing plastic adhesives.

On Electromagnetic Modulation of Flow Instabilities, Mixing and Heat Transfer in Conducting and Magnetized Fluids

NASA Astrophysics Data System (ADS)

Kenjeres, S.

2016-09-01

In the present paper we give a concise review of some recent highlights of our research dealing with electromagnetic control of flow, mixing and heat transfer of electrically conductive or magnetized fluids. We apply a combination of state-of-art numerical (DNS and LES) and experimental (PIV and LIF) techniques to provide fundamental insights into the complex phenomena of interactions between imposed (or induced) electromagnetic fields and underlying fluid flow. Our analysis covers an extensive range of working fluids, i.e. weakly- and highly-electrically-conductive, as well as magnetized fluids. These interactions are defined through the presence of different types of body forces acting per volume of fluid. A fully closed system of governing equations containing an extended set of the Navier-Stokes and a simplified set of the Maxwell equations is presented. The four characteristic examples are selected: the electromagnetic control of self-sustained jet oscillations, the electromagnetic enhancement of heat transfer in thermal convection, the wake interactions behind magnetic obstacles and finally, the thermo-magnetic convection in differentially heated cubical enclosure. The comparative assessment between experimental and numerical results is presented. It is concluded that generally good agreement between simulations and experiments is obtained for all cases considered, proving the concept of electromagnetic modulation, which can be used in numerous technological applications.

Interaction between pancreatic β cell and electromagnetic fields: A systematic study toward finding the natural frequency spectrum of β cell system.

PubMed

Farashi, Sajjad

2017-01-01

Interaction between biological systems and environmental electric or magnetic fields has gained attention during the past few decades. Although there are a lot of studies that have been conducted for investigating such interaction, the reported results are considerably inconsistent. Besides the complexity of biological systems, the important reason for such inconsistent results may arise due to different excitation protocols that have been applied in different experiments. In order to investigate carefully the way that external electric or magnetic fields interact with a biological system, the parameters of excitation, such as intensity or frequency, should be selected purposefully due to the influence of these parameters on the system response. In this study, pancreatic β cell, the main player of blood glucose regulating system, is considered and the study is focused on finding the natural frequency spectrum of the system using modeling approach. Natural frequencies of a system are important characteristics of the system when external excitation is applied. The result of this study can help researchers to select proper frequency parameter for electrical excitation of β cell system. The results show that there are two distinct frequency ranges for natural frequency of β cell system, which consist of extremely low (or near zero) and 100-750 kHz frequency ranges. There are experimental works on β cell exposure to electromagnetic fields that support such finding.

The use of a robotic tibial rotation device and an electromagnetic tracking system to accurately reproduce the clinical dial test.

PubMed

Stinton, S K; Siebold, R; Freedberg, H; Jacobs, C; Branch, T P

2016-03-01

The purpose of this study was to: (1) determine whether a robotic tibial rotation device and an electromagnetic tracking system could accurately reproduce the clinical dial test at 30° of knee flexion; (2) compare rotation data captured at the footplates of the robotic device to tibial rotation data measured using an electromagnetic sensor on the proximal tibia. Thirty-two unilateral ACL-reconstructed patients were examined using a robotic tibial rotation device that mimicked the dial test. The data reported in this study is only from the healthy legs of these patients. Torque was applied through footplates and was measured using servomotors. Lower leg motion was measured at the foot using the motors. Tibial motion was also measured through an electromagnetic tracking system and a sensor on the proximal tibia. Load-deformation curves representing rotational motion of the foot and tibia were compared using Pearson's correlation coefficients. Off-axis motions including medial-lateral translation and anterior-posterior translation were also measured using the electromagnetic system. The robotic device and electromagnetic system were able to provide axial rotation data and translational data for the tibia during the dial test. Motion measured at the foot was not correlated to motion of the tibial tubercle in internal rotation or in external rotation. The position of the tibial tubercle was 26.9° ± 11.6° more internally rotated than the foot at torque 0 Nm. Medial-lateral translation and anterior-posterior translation were combined to show the path of the tubercle in the coronal plane during tibial rotation. The information captured during a manual dial test includes both rotation of the tibia and proximal tibia translation. All of this information can be captured using a robotic tibial axial rotation device with an electromagnetic tracking system. The pathway of the tibial tubercle during tibial axial rotation can provide additional information about knee instability without relying on side-to-side comparison between knees. The translation of the proximal tibia is important information that must be considered in addition to axial rotation of the tibia when performing a dial test whether done manually or with a robotic device. Instrumented foot position cannot provide the same information. IV.

Ultrastructural Study on Ultra-Low Frequency Electromagnetic Fields and Transfer Factor Effects on Skin Ulcers

NASA Astrophysics Data System (ADS)

Cadena, M. S. Reyes; Chapul, L. Sánchez; Pérez, Javiér; García, M. N. Jiménez; López, M. A. Jiménez; Espíndola, M. E. Sánchez; Perez, R. Paniagua; Hernández, N. A.; Paniagua, G.; Uribe, F.; Nava, J. J. Godina; Segura, M. A. Rodríguez

2008-08-01

We determined the effect of 120Hz ultra low frequency electromagnetic field (ELF) on the healing process of skin in 20 Wistar rats distributed in four groups in which chronic dermal ulcers had been produced. The first two groups received a dose of the transfer factor and interferon-beta (IFN-β) every 24 h during 12 days. The third group (positive control) received only electromagnetic field (ELF) sessions, and in the fourth group (negative control), no treatment was applied. The electromagnetic field was applied through a Helmholtz coils; 30 Gauss of intensity. Results shown histological changes that improve the healing process in animals subjected to ELF together with the transfer factor.

Estimating the power-law distribution of Earth electrical conductivity from low-frequency, controlled-source electromagnetic responses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beskardes, G. D.; Weiss, Chester J.; Everett, M. E.

Electromagnetic responses reflect the interaction between applied electromagnetic fields and heterogeneous geoelectrical structures. Here by quantifying the relationship between multi-scale electrical properties and the observed electromagnetic response is therefore important for meaningful geologic interpretation. Furthermore, we present here examples of near-surface electromagnetic responses whose spatial fluctuations appear on all length scales, are repeatable and fractally distributed, suggesting that the spatial fluctuations may be considered as “geologic noise”.

Estimating the power-law distribution of Earth electrical conductivity from low-frequency, controlled-source electromagnetic responses

DOE PAGES

Beskardes, G. D.; Weiss, Chester J.; Everett, M. E.

2016-11-30

Electromagnetic responses reflect the interaction between applied electromagnetic fields and heterogeneous geoelectrical structures. Here by quantifying the relationship between multi-scale electrical properties and the observed electromagnetic response is therefore important for meaningful geologic interpretation. Furthermore, we present here examples of near-surface electromagnetic responses whose spatial fluctuations appear on all length scales, are repeatable and fractally distributed, suggesting that the spatial fluctuations may be considered as “geologic noise”.

40 CFR Appendix A to Subpart Gg of... - Specialty Coating Definitions

Code of Federal Regulations, 2012 CFR

2012-07-01

... electromagnetic energy spectrum, such as the ultraviolet, visible, infrared, or microwave regions. Uses include, but are not limited to, lightning strike protection, electromagnetic pulse (EMP) protection, and radar.... Electrostatic discharge and electromagnetic interference (EMI) coating—A coating applied to space vehicles...

40 CFR Appendix A to Subpart Gg of... - Specialty Coating Definitions

Code of Federal Regulations, 2011 CFR

2011-07-01

... electromagnetic energy spectrum, such as the ultraviolet, visible, infrared, or microwave regions. Uses include, but are not limited to, lightning strike protection, electromagnetic pulse (EMP) protection, and radar.... Electrostatic discharge and electromagnetic interference (EMI) coating—A coating applied to space vehicles...

40 CFR Appendix A to Subpart Gg of... - Specialty Coating Definitions

Code of Federal Regulations, 2010 CFR

2010-07-01

... electromagnetic energy spectrum, such as the ultraviolet, visible, infrared, or microwave regions. Uses include, but are not limited to, lightning strike protection, electromagnetic pulse (EMP) protection, and radar.... Electrostatic discharge and electromagnetic interference (EMI) coating—A coating applied to space vehicles...

40 CFR Appendix A to Subpart Gg of... - Specialty Coating Definitions

Code of Federal Regulations, 2014 CFR

2014-07-01

... electromagnetic energy spectrum, such as the ultraviolet, visible, infrared, or microwave regions. Uses include, but are not limited to, lightning strike protection, electromagnetic pulse (EMP) protection, and radar.... Electrostatic discharge and electromagnetic interference (EMI) coating—A coating applied to space vehicles...

40 CFR Appendix A to Subpart Gg of... - Specialty Coating Definitions

Code of Federal Regulations, 2013 CFR

2013-07-01

... electromagnetic energy spectrum, such as the ultraviolet, visible, infrared, or microwave regions. Uses include, but are not limited to, lightning strike protection, electromagnetic pulse (EMP) protection, and radar.... Electrostatic discharge and electromagnetic interference (EMI) coating—A coating applied to space vehicles...

Time-dependent entropy evolution in microscopic and macroscopic electromagnetic relaxation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker-Jarvis, James

This paper is a study of entropy and its evolution in the time and frequency domains upon application of electromagnetic fields to materials. An understanding of entropy and its evolution in electromagnetic interactions bridges the boundaries between electromagnetism and thermodynamics. The approach used here is a Liouville-based statistical-mechanical theory. I show that the microscopic entropy is reversible and the macroscopic entropy satisfies an H theorem. The spectral entropy development can be very useful for studying the frequency response of materials. Using a projection-operator based nonequilibrium entropy, different equations are derived for the entropy and entropy production and are applied tomore » the polarization, magnetization, and macroscopic fields. I begin by proving an exact H theorem for the entropy, progress to application of time-dependent entropy in electromagnetics, and then apply the theory to relevant applications in electromagnetics. The paper concludes with a discussion of the relationship of the frequency-domain form of the entropy to the permittivity, permeability, and impedance.« less

Mutual interferences and design principles for mechatronic devices in magnetic resonance imaging.

PubMed

Yu, Ningbo; Gassert, Roger; Riener, Robert

2011-07-01

Robotic and mechatronic devices that work compatibly with magnetic resonance imaging (MRI) are applied in diagnostic MRI, image-guided surgery, neurorehabilitation and neuroscience. MRI-compatible mechatronic systems must address the challenges imposed by the scanner's electromagnetic fields. We have developed objective quantitative evaluation criteria for device characteristics needed to formulate design guidelines that ensure MRI-compatibility based on safety, device functionality and image quality. The mutual interferences between an MRI system and mechatronic devices working in its vicinity are modeled and tested. For each interference, the involved components are listed, and a numerical measure for "MRI-compatibility" is proposed. These interferences are categorized into an MRI-compatibility matrix, with each element representing possible interactions between one part of the mechatronic system and one component of the electromagnetic fields. Based on this formulation, design principles for MRI-compatible mechatronic systems are proposed. Furthermore, test methods are developed to examine whether a mechatronic device indeed works without interferences within an MRI system. Finally, the proposed MRI-compatibility criteria and design guidelines have been applied to an actual design process that has been validated by the test procedures. Objective and quantitative MRI-compatibility measures for mechatronic and robotic devices have been established. Applying the proposed design principles, potential problems in safety, device functionality and image quality can be considered in the design phase to ensure that the mechatronic system will fulfill the MRI-compatibility criteria. New guidelines and test procedures for MRI instrument compatibility provide a rational basis for design and evaluation of mechatronic devices in various MRI applications. Designers can apply these criteria and use the tests, so that MRI-compatibility results can accrue to build an experiential database.

Electromagnetic pulses bone healing booster

NASA Astrophysics Data System (ADS)

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.

Electromagnetic Compatibility (EMC) in Microelectronics.

DTIC Science & Technology

1983-02-01

Fault Tree Analysis", System Saftey Symposium, June 8-9, 1965, Seattle: The Boeing Company . 12. Fussell, J.B., "Fault Tree Analysis-Concepts and...procedure for assessing EMC in microelectronics and for applying DD, 1473 EOiTO OP I, NOV6 IS OESOL.ETE UNCLASSIFIED SECURITY CLASSIFICATION OF THIS...CRITERIA 2.1 Background 2 2.2 The Probabilistic Nature of EMC 2 2.3 The Probabilistic Approach 5 2.4 The Compatibility Factor 6 3 APPLYING PROBABILISTIC

Thermophotovoltaic energy generation

DOEpatents

Celanovic, Ivan; Chan, Walker; Bermel, Peter; Yeng, Adrian Y. X.; Marton, Christopher; Ghebrebrhan, Michael; Araghchini, Mohammad; Jensen, Klavs F.; Soljacic, Marin; Joannopoulos, John D.; Johnson, Steven G.; Pilawa-Podgurski, Robert; Fisher, Peter

2015-08-25

Inventive systems and methods for the generation of energy using thermophotovoltaic cells are described. Also described are systems and methods for selectively emitting electromagnetic radiation from an emitter for use in thermophotovoltaic energy generation systems. In at least some of the inventive energy generation systems and methods, a voltage applied to the thermophotovoltaic cell (e.g., to enhance the power produced by the cell) can be adjusted to enhance system performance. Certain embodiments of the systems and methods described herein can be used to generate energy relatively efficiently.

75 FR 5009 - Proximity Detection Systems for Underground Mines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-01

... electromagnetic field based systems. After reviewing the different types of systems, MSHA determined that the electromagnetic field based system offers the greatest potential for reducing pinning, crushing, and striking... near RCCMs. An electromagnetic field based system consists of a combination of electromagnetic field...

Electromagnetic fields in curved spacetimes

NASA Astrophysics Data System (ADS)

Tsagas, Christos G.

2005-01-01

We consider the evolution of electromagnetic fields in curved spacetimes and calculate the exact wave equations for the associated electric and magnetic components. Our analysis is fully covariant, applies to a general spacetime and isolates all the sources that affect the propagation of these waves. Among others, we explicitly show how the different components of the gravitational field act as driving sources of electromagnetic disturbances. When applied to perturbed Friedmann Robertson Walker cosmologies, our results argue for a superadiabatic-type amplification of large-scale cosmological magnetic fields in Friedmann models with open spatial curvature.

Electronic systems failures and anomalies attributed to electromagnetic interference

NASA Technical Reports Server (NTRS)

Leach, R. D. (Editor); Alexander, M. B. (Editor)

1995-01-01

The effects of electromagnetic interference can be very detrimental to electronic systems utilized in space missions. Assuring that subsystems and systems are electrically compatible is an important engineering function necessary to assure mission success. This reference publication will acquaint the reader with spacecraft electronic systems failures and anomalies caused by electromagnetic interference and will show the importance of electromagnetic compatibility activities in conjunction with space flight programs. It is also hoped that the report will illustrate that evolving electronic systems are increasingly sensitive to electromagnetic interference and that NASA personnel must continue to diligently pursue electromagnetic compatibility on space flight systems.

Near Field HF Antenna Pattern Measurement Method Using an Antenna Pattern Range

DTIC Science & Technology

2015-12-01

Year 2015 by the Applied Electromagnetics Branch (Code 52250) of the System of Systems (SoS) & Platform Design Division (Code 52200), Space and...Head SoS & Platform Design Division iii EXECUTIVE SUMMARY The Antenna Pattern Range (APR) is an essential measurement facility operated at Space...14 1 INTRODUCTION Accurate characterization of antennas designed to support the warfighter is a critical

Engineering electromagnetic metamaterials and methanol fuel cells

NASA Astrophysics Data System (ADS)

Yen, Tajen

2005-07-01

Electromagnetic metamaterials represent a group of artificial structures, whose dimensions are smaller than subwavelength. Due to electromagnetic metamaterials' collective response to the applied fields, they can exhibit unprecedented properties to fascinate researchers' eyes. For instance, artificial magnetism above terahertz frequencies and beyond, negative magnetic response, and artificial plasma lower than ultraviolet and visible frequencies. Our goal is to engineer those novel properties aforementioned at interested frequency regions and further optimize their performance. To fulfill this task, we developed exclusive micro/nano fabrication techniques to construct magnetic metamaterials (i.e., split-ring resonators and L-shaped resonators) and electric metamaterials (i.e., plasmonic wires) and also employed Taguchi method to study the optimal design of electromagnetic metamaterials. Moreover, by integrating magnetic and electric metamaterials, we have been pursuing to fabricate so-called negative index media---the Holy Grail enables not only to reverse conventional optical rules such as Snell's law, Doppler shift, and Cerenkov radiation, but also to smash the diffraction limit to realize the superlensing effect. In addition to electromagnetic metamaterials, in this dissertation we also successfully miniaturize silicon-based methanol fuel cells by means of micro-electrical-mechanical-system technique, which promise to provide an integrated micro power source with excellent performance. Our demonstrated power density and energy density are one of the highest in reported documents. Finally, based on the results of metamaterials and micro fuel cells, we intend to supply building blocks to complete an omnipotent device---a system with sensing, communication, computing, power, control, and actuation functions.

Ultrastructural Study on Ultra-Low Frequency Electromagnetic Fields and Transfer Factor Effects on Skin Ulcers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cadena, M. S. Reyes; Chapul, L. Sanchez; Perez, Javier

2008-08-11

We determined the effect of 120Hz ultra low frequency electromagnetic field (ELF) on the healing process of skin in 20 Wistar rats distributed in four groups in which chronic dermal ulcers had been produced. The first two groups received a dose of the transfer factor and interferon-beta (IFN-{beta}) every 24 h during 12 days. The third group (positive control) received only electromagnetic field (ELF) sessions, and in the fourth group (negative control), no treatment was applied. The electromagnetic field was applied through a Helmholtz coils; 30 Gauss of intensity. Results shown histological changes that improve the healing process in animalsmore » subjected to ELF together with the transfer factor.« less

Electromagnetic Launch Vehicle Fairing and Acoustic Blanket Model of Received Power Using FEKO

NASA Technical Reports Server (NTRS)

Trout, Dawn H.; Stanley, James E.; Wahid, Parveen F.

2011-01-01

Evaluating the impact of radio frequency transmission in vehicle fairings is important to electromagnetically sensitive spacecraft. This study employs the multilevel fast multipole method (MLFMM) from a commercial electromagnetic tool, FEKO, to model the fairing electromagnetic environment in the presence of an internal transmitter with improved accuracy over industry applied techniques. This fairing model includes material properties representative of acoustic blanketing commonly used in vehicles. Equivalent surface material models within FEKO were successfully applied to simulate the test case. Finally, a simplified model is presented using Nicholson Ross Weir derived blanket material properties. These properties are implemented with the coated metal option to reduce the model to one layer within the accuracy of the original three layer simulation.

Investigation of Woven Characteristics on Electromagnetic Shielding Behaviour

NASA Astrophysics Data System (ADS)

Javadi Toghchi, M.; Loghin, C.; Cristian, I.; Campagne, C.; Bruniaux, P.; Cayla, A.

2018-06-01

Textiles have been highly applied for electromagnetic shielding purposes due to the increasing concern about health issues caused by human exposure to radiation. Properties of conductive yarn, fabric structure, and garment design have extreme effects on the electromagnetic behaviour and comfort of the final product. Lots of electromagnetic shielding textiles are made of metallic yarns regarding their high electrical conductivity. Therefore, some researchers have worked on electromagnetic shielding textiles made of metals. For example; the shielding effectiveness of woven fabrics made of hybrid yarns containing stainless steel wire was investigated. As discussed earlier, the fabric structure has significant effects on electromagnetic protection. Consequently, woven samples were produced using two different commercial electroconductive yarns (PA12 coated with Ag and Inox) to investigate the effects of the fabric structure. The main purpose was to define the best pattern among three basic woven patterns leads to the highest electromagnetic shielding. Moreover, the different weft yarn densities were applied to examine the effects of yarn density on the level of electromagnetic shielding. The electromagnetic shielding effectiveness of all the 2-layer samples was evaluated in the frequency range from 0.8 to10 GHz in an anechoic chamber. The woven sample with higher yarn density of PA12 coated with Ag yarns shows higher protection against radiation. To conclude, the results show that the yarn properties play the main role in shielding as well as yarn density and fabric pattern.

Electromagnetic environmental criteria for US Army missile systems - EMC, EMR, EMI, EMP, ESD, and lightning

NASA Astrophysics Data System (ADS)

Ponds, Charles D.; Knaur, James A.

1988-01-01

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

Electromagnetic interference in electrical systems of motor vehicles

NASA Astrophysics Data System (ADS)

Dziubiński, M.; Drozd, A.; Adamiec, M.; Siemionek, E.

2016-09-01

Electronic ignition system affects the electronic equipment of the vehicle by electric and magnetic fields. The measurement of radio electromagnetic interference originating from the ignition system affecting the audiovisual test bench was carried out with a variable speed of the ignition system. The paper presents measurements of radio electromagnetic interference in automobiles. In order to determine the level of electromagnetic interference, the audiovisual test bench was equipped with a set of meters for power consumption and assessment of the level of electromagnetic interference. Measurements of the electromagnetic interference level within the audiovisual system were performed on an experimental test bench consisting of the ignition system, starting system and charging system with an alternator and regulator.

Method of eliminating the training effect in superconducting coils by post-wind preload

DOEpatents

Heim, Joseph R.

1976-01-01

The training effect in superconducting coils is eliminated by winding the coil with a composite material that includes both a superconductor and a normal material and then applying stresses to the wound coil in the direction that electromagnetic stresses will be applied to the coil during normal use and in a magnitude greater than the calculated magnitude of the greatest electromagnetic stresses to be applied to the coil.

Enrichment of magnetic particles using temperature and magnetic field gradients induced by benchtop fabricated micro-electromagnets.

PubMed

Hosseini, A; Philpott, D N; Soleymani, L

2017-11-21

The active transport of analytes inside biosensing systems is important for reducing the response time and enhancing the limit-of-detection of these systems. Due to the ease of functionalization with bio-recognition agents and manipulation with magnetic fields, magnetic particles are widely used for active and directed transport of biological analytes. On-chip active electromagnets are ideally suited for manipulating magnetic particles in an automated and miniaturized fashion inside biosensing systems. Unfortunately, the magnetic force exerted by these devices decays rapidly as we move away from the device edges, and increasing the generated force to the levels necessary for particle manipulation requires a parallel increase in the applied current and the resultant Joule heating. In this paper, we designed a study to understand the combined role of thermal and magnetic forces on the movement of magnetic particles in order to extend the interaction distance of on-chip magnetic devices beyond the device edges. For this purpose, we used a rapid prototyping method to create an active/passive on-chip electromagnet with a micro/nano-structured active layer and a patterned ferromagnetic passive layer. We demonstrated that the measured terminal velocities of particles positioned near the electromagnet edge (∼5.5 μm) closely reflect the values obtained by multi-physics modelling. Interestingly, we observed a two orders of magnitude deviation between the experimental and modelling results for the terminal velocities of particles far from the electromagnet edge (∼55.5 μm). Heat modelling of the system using experimentally-measured thermal gradients indicates that this discrepancy is related to the enhanced fluid movement caused by thermal forces. This study enables the rational design of thermo-magnetic systems for thermally driving and magnetically capturing particles that are positioned at distances tens to hundreds of microns away from the edges of on-chip magnetic devices.

Electromagnetic disturbance of electric drive system signal is extracted based on PLS

NASA Astrophysics Data System (ADS)

Wang, Yun; Wang, Chuanqi; Yang, Weidong; Zhang, Xu; Jiang, Li; Hou, Shuai; Chen, Xichen

2018-05-01

At present ISO11452 and GB/T33014 specified by electromagnetic immunity are narrowband electromagnetic radiation, but our exposure to electromagnetic radiation at ordinary times is not only a narrowband electromagnetic radiation, and some broadband electromagnetic radiation, and even some of the more complex electromagnetic environment. In terms of Electric vehicles, electric drive system is a kind of complex electromagnetic disturbance source, is not only a narrow-band signal, there are a lot of broadband signal, this paper puts forward PLS data processing method is adopted to analyze the electric drive system of electromagnetic disturbance, this kind of method to extract the data can be provide reliable data support for future standards.

Design and fabrication of planar structures with graded electromagnetic properties

NASA Astrophysics Data System (ADS)

Good, Brandon Lowell

Successfully integrating electromagnetic properties in planar structures offers numerous benefits to the microwave and optical communities. This work aims at formulating new analytic and optimized design methods, creating new fabrication techniques for achieving those methods, and matching appropriate implementation of methods to fabrication techniques. The analytic method consists of modifying an approach that realizes perfect antireflective properties from graded profiles. This method is shown for all-dielectric and magneto-dielectric grading profiles. The optimized design methods are applied to transformer (discrete) or taper (continuous) designs. From these methods, a subtractive and an additive manufacturing technique were established and are described. The additive method, dry powder dot deposition, enables three dimensional varying electromagnetic properties in a structural composite. Combining the methods and fabrication is shown in two applied methodologies. The first uses dry powder dot deposition to design one dimensionally graded electromagnetic profiles in a planar fiberglass composite. The second method simultaneously applies antireflective properties and adjusts directivity through a slab through the use of subwavelength structures to achieve a flat antireflective lens. The end result of this work is a complete set of methods, formulations, and fabrication techniques to achieve integrated electromagnetic properties in planar structures.

Distributed source model for the full-wave electromagnetic simulation of nonlinear terahertz generation.

PubMed

Fumeaux, Christophe; Lin, Hungyen; Serita, Kazunori; Withayachumnankul, Withawat; Kaufmann, Thomas; Tonouchi, Masayoshi; Abbott, Derek

2012-07-30

The process of terahertz generation through optical rectification in a nonlinear crystal is modeled using discretized equivalent current sources. The equivalent terahertz sources are distributed in the active volume and computed based on a separately modeled near-infrared pump beam. This approach can be used to define an appropriate excitation for full-wave electromagnetic numerical simulations of the generated terahertz radiation. This enables predictive modeling of the near-field interactions of the terahertz beam with micro-structured samples, e.g. in a near-field time-resolved microscopy system. The distributed source model is described in detail, and an implementation in a particular full-wave simulation tool is presented. The numerical results are then validated through a series of measurements on square apertures. The general principle can be applied to other nonlinear processes with possible implementation in any full-wave numerical electromagnetic solver.

Biomolecular structure manipulation using tailored electromagnetic radiation: a proof of concept on a simplified model of the active site of bacterial DNA topoisomerase.

PubMed

Jarukanont, Daungruthai; Coimbra, João T S; Bauerhenne, Bernd; Fernandes, Pedro A; Patel, Shekhar; Ramos, Maria J; Garcia, Martin E

2014-10-21

We report on the viability of breaking selected bonds in biological systems using tailored electromagnetic radiation. We first demonstrate, by performing large-scale simulations, that pulsed electric fields cannot produce selective bond breaking. Then, we present a theoretical framework for describing selective energy concentration on particular bonds of biomolecules upon application of tailored electromagnetic radiation. The theory is based on the mapping of biomolecules to a set of coupled harmonic oscillators and on optimal control schemes to describe optimization of temporal shape, the phase and polarization of the external radiation. We have applied this theory to demonstrate the possibility of selective bond breaking in the active site of bacterial DNA topoisomerase. For this purpose, we have focused on a model that was built based on a case study. Results are given as a proof of concept.

Basic EMC (Electromagnetic compatibility) technology advancement for C3 (Command, control, and communications) systems. Volume 6

NASA Astrophysics Data System (ADS)

Weiner, D.; Paul, C. R.; Whalen, J.

1985-04-01

This research effort was devoted to eliminating some of the basic technological gaps in the two important areas of: (1) electromagnetic effects (EM) on microelectronic circuits and (2) EM coupling and testing. The results are presented in fourteen reports which have been organized into six volumes. The reports are briefly summarized in this volume. In addition, an experiment is described which was performed to demonstrate the feasibility of applying several of the results to a problem involving electromagnetic interference. Specifically, experimental results are provided for the randomness associated with: (1) crosstalk in cable harnesses and (2) demodulation of amplitude modulated (AM) signals in operational amplifiers. These results are combined to predict candidate probability density functions (pdf's) for the amplitude of an AM interfering signal required to turn on a light emitting diode. The candidate pdf's are shown to be statistically consistent with measured data.

Simultaneous localization and calibration for electromagnetic tracking systems.

PubMed

Sadjadi, Hossein; Hashtrudi-Zaad, Keyvan; Fichtinger, Gabor

2016-06-01

In clinical environments, field distortion can cause significant electromagnetic tracking errors. Therefore, dynamic calibration of electromagnetic tracking systems is essential to compensate for measurement errors. It is proposed to integrate the motion model of the tracked instrument with redundant EM sensor observations and to apply a simultaneous localization and mapping algorithm in order to accurately estimate the pose of the instrument and create a map of the field distortion in real-time. Experiments were conducted in the presence of ferromagnetic and electrically-conductive field distorting objects and results compared with those of a conventional sensor fusion approach. The proposed method reduced the tracking error from 3.94±1.61 mm to 1.82±0.62 mm in the presence of steel, and from 0.31±0.22 mm to 0.11±0.14 mm in the presence of aluminum. With reduced tracking error and independence from external tracking devices or pre-operative calibrations, the approach is promising for reliable EM navigation in various clinical procedures. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Oxidative response of human monocytes and macrophages cultured under low oxygen culture conditions to ion parametric resonance magnetic fields.

EPA Science Inventory

INTRODUCTION One proposed mechanism of action of electromagnetic fields (EMFs) on biological systems is the Ion Parametric Resonance (IPR) model, which has been experimentally validated in neuronal PC-12 cells [1, 2]. It proposes that when applied EMFs are tuned to resonate with...

ELECTROMAGNETICALLY INDUCED DISTORTION OF A FIBRIN MATRIX WITH EMBEDDED MICROPARTICLES

PubMed Central

SCOGIN, TYLER; YESUDASAN, SUMITH; WALKER, MITCHELL L. R.

2018-01-01

Blood clots occur in the human body when they are required to prevent bleeding. In pathological states such as diabetes and sickle cell disease, blood clots can also form undesirably due to hypercoagulable plasma conditions. With the continued effort in developing fibrin therapies for potential life-saving solutions, more mechanical modeling is needed to understand the properties of fibrin structures with inclusions. In this study, a fibrin matrix embedded with magnetic micro particles (MMPs) was subjected to a magnetic field to determine the magnitude of the required force to create plastic deformation within the fibrin clot. Using finite element (FE) analysis, we estimated the magnetic force from an electromagnet at a sample space located approximately 3 cm away from the coil center. This electromagnetic force coupled with gravity was applied on a fibrin mechanical system with MMPs to calculate the stresses and displacements. Using appropriate coil parameters, it was determined that application of a magnetic field of 730 A/m on the fibrin surface was necessary to achieve an electromagnetic force of 36 nN (to engender plastic deformation). PMID:29628543

No effects of pulsed radio frequency electromagnetic fields on melatonin, cortisol, and selected markers of the immune system in man.

PubMed

Radon, K; Parera, D; Rose, D M; Jung, D; Vollrath, L

2001-05-01

There is growing public concern that radio frequency electromagnetic fields may have adverse biological effects. In the present study eight healthy male students were tested to see whether or not radio frequency electromagnetic fields as used in modern digital wireless telecommunication (GSM standard) have noticeable effects on salivary melatonin, cortisol, neopterin, and immunoglobulin A (sIgA) levels during and several hours after exposure. In a specifically designed, shielded experimental chamber, the circularly polarized electromagnetic field applied was transmitted by an antenna positioned 10 cm behind the head of upright sitting test persons. The carrier frequency of 900 MHz was pulsed with 217 Hz (average power flux density 1 W/m2). In double blind trials, each test person underwent a total of 20 randomly allotted 4 hour periods of exposure and sham exposure, equally distributed at day and night. The results obtained show that the salivary concentrations of melatonin, cortisol, neopterin and sIgA did not differ significantly between exposure and sham exposure. Copyright 2001 Wiley-Liss, Inc.

Multi-resonant electromagnetic shunt in base isolation for vibration damping and energy harvesting

NASA Astrophysics Data System (ADS)

Pei, Yalu; Liu, Yilun; Zuo, Lei

2018-06-01

This paper investigates multi-resonant electromagnetic shunts applied to base isolation for dual-function vibration damping and energy harvesting. Two multi-mode shunt circuit configurations, namely parallel and series, are proposed and optimized based on the H2 criteria. The root-mean-square (RMS) value of the relative displacement between the base and the primary structure is minimized. Practically, this will improve the safety of base-isolated buildings subjected the broad bandwidth ground acceleration. Case studies of a base-isolated building are conducted in both the frequency and time domains to investigate the effectiveness of multi-resonant electromagnetic shunts under recorded earthquake signals. It shows that both multi-mode shunt circuits outperform traditional single mode shunt circuits by suppressing the first and the second vibration modes simultaneously. Moreover, for the same stiffness ratio, the parallel shunt circuit is more effective at harvesting energy and suppressing vibration, and can more robustly handle parameter mistuning than the series shunt circuit. Furthermore, this paper discusses experimental validation of the effectiveness of multi-resonant electromagnetic shunts for vibration damping and energy harvesting on a scaled-down base isolation system.

Development and Application of a Wireless Sensor for Space Charge Density Measurement in an Ultra-High-Voltage, Direct-Current Environment

PubMed Central

Xin, Encheng; Ju, Yong; Yuan, Haiwen

2016-01-01

A space charge density wireless measurement system based on the idea of distributed measurement is proposed for collecting and monitoring the space charge density in an ultra-high-voltage direct-current (UHVDC) environment. The proposed system architecture is composed of a number of wireless nodes connected with space charge density sensors and a base station. The space charge density sensor based on atmospheric ion counter method is elaborated and developed, and the ARM microprocessor and Zigbee radio frequency module are applied. The wireless network communication quality and the relationship between energy consumption and transmission distance in the complicated electromagnetic environment is tested. Based on the experimental results, the proposed measurement system demonstrates that it can adapt to the complex electromagnetic environment under the UHVDC transmission lines and can accurately measure the space charge density. PMID:27775627

Development and Application of a Wireless Sensor for Space Charge Density Measurement in an Ultra-High-Voltage, Direct-Current Environment.

PubMed

Xin, Encheng; Ju, Yong; Yuan, Haiwen

2016-10-20

A space charge density wireless measurement system based on the idea of distributed measurement is proposed for collecting and monitoring the space charge density in an ultra-high-voltage direct-current (UHVDC) environment. The proposed system architecture is composed of a number of wireless nodes connected with space charge density sensors and a base station. The space charge density sensor based on atmospheric ion counter method is elaborated and developed, and the ARM microprocessor and Zigbee radio frequency module are applied. The wireless network communication quality and the relationship between energy consumption and transmission distance in the complicated electromagnetic environment is tested. Based on the experimental results, the proposed measurement system demonstrates that it can adapt to the complex electromagnetic environment under the UHVDC transmission lines and can accurately measure the space charge density.

Feasibility results of an electromagnetic compatibility test protocol to evaluate medical devices to radio frequency identification exposure

PubMed Central

2014-01-01

Background The use of radio frequency identification (RFID) systems in healthcare is increasing, and concerns for electromagnetic compatibility (EMC) pose one of the biggest obstacles for widespread adoption. Numerous studies have demonstrated that RFID systems can interfere with medical devices; however, the majority of past studies relied on time-consuming and burdensome test schemes based on ad hoc test methods applied to individual RFID systems. Methods This paper presents the results of using an RFID simulator that allows for faster evaluation of RFID-medical device EMC against a library of RFID test signals at various field strengths. Results The results of these tests demonstrate the feasibility and adequacy of simulator testing and can be used to support its incorporation into applicable consensus standards. Conclusions This work can aid the medical device community in better assessing the risks associated with medical device exposure to RFID. PMID:25086451

Feasibility results of an electromagnetic compatibility test protocol to evaluate medical devices to radio frequency identification exposure.

PubMed

Seidman, Seth J; Bekdash, Omar; Guag, Joshua; Mehryar, Maryam; Booth, Paul; Frisch, Paul

2014-08-03

The use of radio frequency identification (RFID) systems in healthcare is increasing, and concerns for electromagnetic compatibility (EMC) pose one of the biggest obstacles for widespread adoption. Numerous studies have demonstrated that RFID systems can interfere with medical devices; however, the majority of past studies relied on time-consuming and burdensome test schemes based on ad hoc test methods applied to individual RFID systems. This paper presents the results of using an RFID simulator that allows for faster evaluation of RFID-medical device EMC against a library of RFID test signals at various field strengths. The results of these tests demonstrate the feasibility and adequacy of simulator testing and can be used to support its incorporation into applicable consensus standards. This work can aid the medical device community in better assessing the risks associated with medical device exposure to RFID.

Large-stroke convex micromirror actuated by electromagnetic force for optical power control.

PubMed

Hossain, Md Mahabub; Bin, Wu; Kong, Seong Ho

2015-11-02

This paper contributes a novel design and the corresponding fabrication process to research on the unique topic of micro-electro-mechanical systems (MEMS) deformable convex micromirror used for focusing-power control. In this design, the shape of a thin planar metal-coated polymer-membrane mirror is controlled electromagnetically by using the repulsive force between two magnets, a permanent magnet and a coil solenoid, installed in an actuator system. The 5 mm effective aperture of a large-stroke micromirror showed a maximum center displacement of 30.08 µm, which enabled control of optical power across a wide range that could extend up to around 20 diopters. Specifically, utilizing the maximum optical power of 20 diopter by applying a maximum controlling current of 0.8 A yielded consumption of at most 2 W of electrical power. It was also demonstrated that this micromirror could easily be integrated in miniature tunable optical imaging systems.

Numerical analysis of the shifting slabs applied in a wireless power transfer system to enhance magnetic coupling

NASA Astrophysics Data System (ADS)

Dong, Yayun; Yang, Xijun; Jin, Nan; Li, Wenwen; Yao, Chen; Tang, Houjun

2017-05-01

Shifting medium is a kind of metamaterial, which can optically shift a space or an object a certain distance away from its original position. Based on the shifting medium, we propose a concise pair of shifting slabs covering the transmitting or receiving coil in a two-coil wireless power transfer system to decrease the equivalent distance between the coils. The electromagnetic parameters of the shifting slabs are calculated by transformation optics. Numerical simulations validate that the shifting slabs can approximately shift the electromagnetic fields generated by the covered coil; thus, the magnetic coupling and the efficiency of the system are enhanced while remaining the physical transmission distance unchanged. We also verify the advantages of the shifting slabs over the magnetic superlens. Finally, we provide two methods to fabricate shifting slabs based on split-ring resonators.

Adiabatic description of capture into resonance and surfatron acceleration of charged particles by electromagnetic waves.

PubMed

Artemyev, A V; Neishtadt, A I; Zelenyi, L M; Vainchtein, D L

2010-12-01

We present an analytical and numerical study of the surfatron acceleration of nonrelativistic charged particles by electromagnetic waves. The acceleration is caused by capture of particles into resonance with one of the waves. We investigate capture for systems with one or two waves and provide conditions under which the obtained results can be applied to systems with more than two waves. In the case of a single wave, the once captured particles never leave the resonance and their velocity grows linearly with time. However, if there are two waves in the system, the upper bound of the energy gain may exist and we find the analytical value of that bound. We discuss several generalizations including the relativistic limit, different wave amplitudes, and a wide range of the waves' wavenumbers. The obtained results are used for qualitative description of some phenomena observed in the Earth's magnetosphere. © 2010 American Institute of Physics.

Electromagnetically Operated Counter

DOEpatents

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.

Natural Crack Sizing Based on Eddy Current Image and Electromagnetic Field Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Endo, H.; Uchimoto, T.; Takagi, T.

2006-03-06

An eddy current testing (ECT) system with multi-coil type probes is applied to size up cracks fabricated on austenite stainless plates. We have developed muti-channel ECT system to produce data as digital images. The probes consist of transmit-receive type sensors as elements to classify crack directions, working as two scan direction modes simultaneously. Template matching applied to the ECT images determines regions of interest in sizing up cracks. Finite element based inversion sizes up the crack depth from the measured ECT signal. The present paper demonstrates this approach for fatigue crack and stress corrosion cracking.

Waste remediation

DOEpatents

Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

2017-01-17

A system including a steam generation system and a chamber. The steam generation system includes a complex and the steam generation system is configured to receive water, concentrate electromagnetic (EM) radiation received from an EM radiation source, apply the EM radiation to the complex, where the complex absorbs the EM radiation to generate heat, and transform, using the heat generated by the complex, the water to steam. The chamber is configured to receive the steam and an object, wherein the object is of medical waste, medical equipment, fabric, and fecal matter.

Waste remediation

DOEpatents

Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

2015-12-29

A system including a steam generation system and a chamber. The steam generation system includes a complex and the steam generation system is configured to receive water, concentrate electromagnetic (EM) radiation received from an EM radiation source, apply the EM radiation to the complex, where the complex absorbs the EM radiation to generate heat, and transform, using the heat generated by the complex, the water to steam. The chamber is configured to receive the steam and an object, wherein the object is of medical waste, medical equipment, fabric, and fecal matter.

Electromagnetically induced acoustic emission—novel NDT technique for damage evaluation

NASA Astrophysics Data System (ADS)

Finkel, P.; Godinez, V.; Miller, R.; Finlayson, R.

2001-04-01

A recently developed electromagnetically induced acoustic emission technique (EM AE) which can be used for damage assessment of thin walled conducting structures is described. This technique allows a structure to be loaded locally by applying an electromagnetic field in order to produce an AE response, which may be captured by conventional or fiber optic (FO) AE sensors. The advantage of this technique is that the localized dynamic stresses induced by a short current pulse in the presence of an external magnetic field aid in the detection of cracks. Also, it is shown that electromagnetic stimulation can be applied to enhance conventional ultrasonics by modulation of the scattered signal from the defect (EM UT). Experimental data is presented for the case of a fatigue crack near rivet holes in thin walled aluminum structures.

77 FR 39953 - Effective Date of Requirement for Premarket Approval for Shortwave Diathermy for All Other Uses

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-06

... body electromagnetic energy in the radio frequency bands of 13 megahertz to 27.12 megahertz and is... device that applies to the body electromagnetic energy in the radio frequency bands of 13 megahertz to 27... other uses. Cellular or Tissue Injury: There is uncertainty concerning the effects of electromagnetic...

Underwater Advanced Time-Domain Electromagnetic System

DTIC Science & Technology

2017-03-03

SUPPLEMENTARY NOTES 14. ABSTRACT The overall objective of the project is to design , build and demonstrate an underwater advanced time -domain...Description The overall objective of the project is to design , build and demonstrate an underwater advanced time - domain electromagnetic (TEM) system...Electromagnetic System Design (July, 2015), and in the Underwater Advanced Time -Domain Electromagnetic System Evaluation Plan (October, 2016). A

Nonlinear oscillation of a rigid body over high- Tc superconductors supported by electro-magnetic forces

NASA Astrophysics Data System (ADS)

Sugiura, T.; Ogawa, S.; Ura, H.

2005-10-01

Characteristics of high- Tc superconducting levitation systems are no contact support and stable levitation without control. They can be applied to supporting mechanisms in machines, such as linear-drives and magnetically levitated trains. But small damping due to noncontact support and nonlinearity in the magnetic force can easily cause complicated phenomena of nonlinear dynamics. This research deals with nonlinear oscillation of a rigid bar supported at its both ends by electro-magnetic forces between superconductors and permanent magnets as a simple modeling of the above application. Deriving the equation of motion, we discussed an effect of nonlinearity in the magnetic force on dynamics of the levitated body: occurrence of combination resonance in the asymmetrical system. Numerical analyses and experiments were also carried out, and their results confirmed the above theoretical prediction.

Amplitude control of the track-induced self-excited vibration for a maglev system.

PubMed

Zhou, Danfeng; Li, Jie; Zhang, Kun

2014-09-01

The Electromagnet Suspension (EMS) maglev train uses controlled electromagnetic forces to achieve suspension, and self-excited vibration may occur due to the flexibility of the track. In this article, the harmonic balance method is applied to investigate the amplitude of the self-excited vibration, and it is found that the amplitude of the vibration depends on the voltage of the power supplier. Based on this observation, a vibration amplitude control method, which controls the amplitude of the vibration by adjusting the voltage of the power supplier, is proposed to attenuate the vibration. A PI controller is designed to control the amplitude of the vibration at a given level. The effectiveness of this method shows a good prospect for its application to commercial maglev systems. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

A multi-purpose electromagnetic actuator for magnetic resonance elastography.

PubMed

Feng, Yuan; Zhu, Mo; Qiu, Suhao; Shen, Ping; Ma, Shengyuan; Zhao, Xuefeng; Hu, Chun-Hong; Guo, Liang

2018-04-19

An electromagnetic actuator was designed for magnetic resonance elastography (MRE). The actuator is unique in that it is simple, portable, and capable of brain, abdomen, and phantom imagings. A custom-built control unit was used for controlling the vibration frequency and synchronizing the trigger signals. An actuation unit was built and mounted on the specifically designed clamp and holders for different imaging applications. MRE experiments with respect to gel phantoms, brain, and liver showed that the actuator could produce stable and consistent mechanical waves. Estimated shear modulus using local frequency estimate method demonstrated that the measurement results were in line with that from MRE studies using different actuation systems. The relatively easy setup procedure and simple design indicated that the actuator system had the potential to be applied in many different clinical studies. Copyright © 2018 Elsevier Inc. All rights reserved.

A Low Frequency Electromagnetic Sensor for Underwater Geo-Location

DTIC Science & Technology

2011-05-01

used a set of commercially available fluxgate magnetometers to measure the magnetic field gradients associated with a magnetic dipole transmitter...insight into the operational capabilities of commercial fluxgate sensors. Figure 42. Applied Physics Systems 1540 magnetometer ...a magnetic field gradient receiver array. Highest quality gradient estimates were achieved with three vector magnetometers equally spaced and

[The physical methods for the prevention and management of weather-dependent pathological reactions (a literature review)].

PubMed

Vasilenko, A M; Agasarov, L G; Sharipova, M M

The review presents data on the non-pharmacological methods and technologies for the prevention and management of meteopathic reactions (MPR) applied in Russia for the treatment of the patients suffering from obstructive and cardiovascular diseases. It is assumed, based on the concept of heliogeophysical imprinting, that the major factors responsible for the development of MPR are the disturbances of electromagnetic homeostasis. The acupuncture points and channels are regarded as a system designed for the maintenance of electromagnetic balance in the human body. In this context, it is proposed to encourage the application of the methods of electro-diagnostics and reflexology for the prevention and correction of meteopathic reactions.

21 CFR 890.5275 - Microwave diathermy.

Code of Federal Regulations, 2012 CFR

2012-04-01

... medical conditions is a device that applies to specific areas of the body electromagnetic energy in the... electromagnetic energy in the microwave frequency bands of 915 megahertz to 2,450 megahertz and that is intended...

21 CFR 890.5275 - Microwave diathermy.

Code of Federal Regulations, 2010 CFR

2010-04-01

... medical conditions is a device that applies to specific areas of the body electromagnetic energy in the... electromagnetic energy in the microwave frequency bands of 915 megahertz to 2,450 megahertz and that is intended...

21 CFR 890.5275 - Microwave diathermy.

Code of Federal Regulations, 2011 CFR

2011-04-01

... medical conditions is a device that applies to specific areas of the body electromagnetic energy in the... electromagnetic energy in the microwave frequency bands of 915 megahertz to 2,450 megahertz and that is intended...

21 CFR 890.5275 - Microwave diathermy.

Code of Federal Regulations, 2013 CFR

2013-04-01

... medical conditions is a device that applies to specific areas of the body electromagnetic energy in the... electromagnetic energy in the microwave frequency bands of 915 megahertz to 2,450 megahertz and that is intended...

21 CFR 890.5275 - Microwave diathermy.

Code of Federal Regulations, 2014 CFR

2014-04-01

... medical conditions is a device that applies to specific areas of the body electromagnetic energy in the... electromagnetic energy in the microwave frequency bands of 915 megahertz to 2,450 megahertz and that is intended...

Magneto acoustic emission apparatus for testing materials for embrittlement

NASA Technical Reports Server (NTRS)

Allison, Sidney G. (Inventor); Min, Namkung (Inventor); Yost, William T. (Inventor); Cantrell, John H. (Inventor)

1990-01-01

A method and apparatus for testing steel components for temper embrittlement uses magneto-acoustic emission to nondestructively evaluate the component. Acoustic emission signals occur more frequently at higher levels in embrittled components. A pair of electromagnets are used to create magnetic induction in the test component. Magneto-acoustic emission signals may be generated by applying an ac current to the electromagnets. The acoustic emission signals are analyzed to provide a comparison between a component known to be unembrittled and a test component. Magnetic remanence is determined by applying a dc current to the electromagnets, then turning the magnets off and observing the residual magnetic induction.

Applied Computational Electromagnetics Society Journal, Volume 9, Number 2

DTIC Science & Technology

1994-07-01

input/output standardization; code or technique optimization and error minimization; innovations in solution technique or in data input/output...THE APPLIED COMPUTATIONAL ELECTROMAGNETICS SOCIETY JOURNAL EDITORS 3DITOR-IN-CH•IF/ACES EDITOR-IN-CHIEP/JOURNAL MANAGING EDITOR W. Perry Wheless...Adalbert Konrad and Paul P. Biringer Department of Electrical and Computer Engineering, University of Toronto Toronto, Ontario, CANADA M5S 1A4 Ailiwir

High speed data transmission coaxial-cable in the space communication system

NASA Astrophysics Data System (ADS)

Su, Haohang; Huang, Jing

2018-01-01

An effective method is proved based on the scattering parameter of high speed 8-core coaxial-cable measured by vector network analyzer, and the semi-physical simulation is made to receive the eye diagram at different data transmission rate. The result can be apply to analysis decay and distortion of the signal through the coaxial-cable at high frequency, and can extensively design for electromagnetic compatibility of high-speed data transmission system.

Preliminary investigations of design philosophies and features applicable to large magnetic suspension and balance systems

NASA Technical Reports Server (NTRS)

Britcher, C. P.; Fortescue, P. W.; Allcock, G. A.; Goodyer, M. J.

1979-01-01

The technology which is required to allow the principles of magnetic suspension and balance systems (MSBS) to be applied to the high Reynolds number transonic testing of aircraft models is examined. A test facility is presented as comprising a pressurized transonic cryogenic wind tunnel, with the MSBS providing full six degree of freedom control. The electro-magnets which are superconducting and fed from quiet, bipolar power supplies are examined. A model control system having some self adaptive characteristics is discussed.

Applied Computational Electromagnetics Society Journal. Volume 7, Number 1, Summer 1992

DTIC Science & Technology

1992-01-01

previously-solved computational problem in electrical engineering, physics, or related fields of study. The technical activities promoted by this...in solution technique or in data input/output; identification of new applica- tions for electromagnetics modeling codes and techniques; integration of...papers will represent the computational electromagnetics aspects of research in electrical engineering, physics, or related disciplines. However, papers

High temperature electromagnetic characterization of thermal protection system tile materials

NASA Technical Reports Server (NTRS)

Heil, Garrett G.

1993-01-01

This study investigated the impact of elevated temperatures on the electromagnetic performance of the LI-2200 thermal protection system. A 15-kilowatt CO2 laser was used to heat an LI-2200 specimen to 3000 F while electromagnetic measurements were performed over the frequency range of l9 to 21 GHz. The electromagnetic measurement system consisted of two Dual-Lens Spot-Focusing (DLSF) antennas, a sample support structure, and an HP-8510B vector network analyzer. Calibration of the electromagnetic system was accomplished with a Transmission-Reflection-Line (TRL) procedure and was verified with measurements on a two-layer specimen of known properties. The results of testing indicated that the LI-2200 system's electromagnetic performance is slightly temperature dependent at temperatures up to 3000 F.

Selective microrobot control using a thermally responsive microclamper for microparticle manipulation

NASA Astrophysics Data System (ADS)

Go, Gwangjun; Choi, Hyunchul; Jeong, Semi; Ko, Seong Young; Park, Jong-Oh; Park, Sukho

2016-03-01

Microparticle manipulation using a microrobot in an enclosed environment, such as a lab-on-a-chip, has been actively studied because an electromagnetic actuated microrobot can have accurate motility and wireless controllability. In most studies on electromagnetic actuated microrobots, only a single microrobot has been used to manipulate cells or microparticles. However, the use of a single microrobot can pose several limitations when performing multiple roles in microparticle manipulation. To overcome the limitations associated with using a single microrobot, we propose a new method for the control of multiple microrobots. Multiple microrobots can be controlled independently by an electromagnetic actuation system and multiple microclampers combined with microheaters. To select a specific microrobot among multiple microrobots, we propose a microclamper composed of a clamper structure using thermally responsive hydrogel and a microheater for controlling the microclamper. A fundamental test of the proposed microparticle manipulation system is performed by selecting a specific microrobot among multiple microrobots. Through the independent locomotion of multiple microrobots with U- and V-shaped tips, heterogeneous microparticle manipulation is demonstrated in the creation of a two-dimensional structure. In the future, our proposed multiple-microrobot system can be applied to tasks that are difficult to perform using a single microrobot, such as cell manipulation, cargo delivery, tissue assembly, and cloning.

A motionless actuation system for magnetic shape memory devices

NASA Astrophysics Data System (ADS)

Armstrong, Andrew; Finn, Kevin; Hobza, Anthony; Lindquist, Paul; Rafla, Nader; Müllner, Peter

2017-10-01

Ni-Mn-Ga is a Magnetic Shape Memory (MSM) alloy that changes shape in response to a variable magnetic field. We can intentionally manipulate the shape of the material to function as an actuator, and the material can thus replace complicated small electromechanical systems. In previous work, a very simple and precise solid-state micropump was developed, but a mechanical rotation was required to translate the position of the magnetic field. This mechanical rotation defeats the purpose of the motionless solid-state device. Here we present a solid-state electromagnetic driver to linearly progress the position of the applied magnetic field and the associated shrinkage. The generated magnetic field was focused at either of two pole pieces, providing a mechanism for moving the localized shrinkage in the MSM element. We confirmed that our driver has sufficient strength to actuate the MSM element using optical microscopy. We validated the whole design by comparing results obtained with finite element analysis with the experimentally measured flux density. This drive system serves as a possible replacement to the mechanical rotation of the magnetic field by using a multi-pole electromagnet that sweeps the magnetic field across the MSM micropump element, solid-state switching the current to each pole piece in the multi-pole electromagnet.

Applying TM-polarization geoelectric exploration for study of low-contrast three-dimensional targets

NASA Astrophysics Data System (ADS)

Zlobinskiy, Arkadiy; Mogilatov, Vladimir; Shishmarev, Roman

2018-03-01

With using new field and theoretical data, it has been shown that applying the electromagnetic field of transverse magnetic (TM) polarization will give new opportunities for electrical prospecting by the method of transient processes. Only applying a pure field of the TM polarization permits poor three-dimensional objects (required metalliferous deposits) to be revealed in a host horizontally-layered medium. This position has good theoretical grounds. There is given the description of the transient electromagnetic method, that uses only the TM polarization field. The pure TM mode is excited by a special source, which is termed as a circular electric dipole (CED). The results of three-dimensional simulation (by the method of finite elements) are discussed for three real geological situations for which applying electromagnetic fields of transverse electric (TE) and transverse magnetic (TM) polarizations are compared. It has been shown that applying the TE mode gives no positive results, while applying the TM polarization field permits the problem to be tackled. Finally, the results of field works are offered, which showed inefficiency of application of the classical TEM method, whereas in contrast, applying the field of TM polarization makes it easy to identify the target.

21 CFR 890.5290 - Shortwave diathermy.

Code of Federal Regulations, 2014 CFR

2014-04-01

... medical conditions is a device that applies to specific areas of the body electromagnetic energy in the... electromagnetic energy in the radio frequency bands of 13 megahertz to 27.12 megahertz and that is intended for...

21 CFR 890.5290 - Shortwave diathermy.

Code of Federal Regulations, 2013 CFR

2013-04-01

... medical conditions is a device that applies to specific areas of the body electromagnetic energy in the... electromagnetic energy in the radio frequency bands of 13 megahertz to 27.12 megahertz and that is intended for...

21 CFR 890.5290 - Shortwave diathermy.

Code of Federal Regulations, 2010 CFR

2010-04-01

... medical conditions is a device that applies to specific areas of the body electromagnetic energy in the... electromagnetic energy in the radio frequency bands of 13 megahertz to 27.12 megahertz and that is intended for...

21 CFR 890.5290 - Shortwave diathermy.

Code of Federal Regulations, 2011 CFR

2011-04-01

... medical conditions is a device that applies to specific areas of the body electromagnetic energy in the... electromagnetic energy in the radio frequency bands of 13 megahertz to 27.12 megahertz and that is intended for...

Electrical wire insulation and electromagnetic coil

DOEpatents

Bich, George J.; Gupta, Tapan K.

1984-01-01

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

21 CFR 890.5290 - Shortwave diathermy.

Code of Federal Regulations, 2012 CFR

2012-04-01

... medical conditions is a device that applies to specific areas of the body electromagnetic energy in the... electromagnetic energy in the radio frequency bands of 13 megahertz to 27.12 megahertz and that is intended for...

Electromagnetic Environmental Effects System Testing

DTIC Science & Technology

2009-09-02

Procedure (TOP) 1-2-511 Electromagnetic Environmental Effects System Testing 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...airborne, sea, space, and ground systems , including associated ordnance, as stated in military standard (MIL-STD)-464A “Electromagnetic Environmental...Effects Requirement for Systems ”, as well as ADS-37A-PRF “Aeronautical Design Standard for the Electromagnetic Environmental Effects (E3) Performance and

Illumination system having a plurality of movable sources

DOEpatents

Sweatt, William C.; Kubiak, Glenn D.

2002-01-01

An illumination system includes several discharge sources that are multiplexed together to reduce the amount of debris generated. The system includes: (a) a first electromagnetic radiation source array that includes a plurality of first activatable radiation source elements that are positioned on a first movable carriage; (b) a second electromagnetic radiation source array that includes a plurality of second activatable radiation source elements that are positioned on a second movable carriage; (c) means for directing electromagnetic radiation from the first electromagnetic radiation source array and electromagnetic radiation from the second electromagnetic radiation source array toward a common optical path; (d) means for synchronizing (i) the movements of the first movable carriage and of the second movable carriage and (ii) the activation of the first electromagnetic radiation source array and of the second electromagnetic radiation source array to provide an essentially continuous illumination of electromagnetic radiation along the common optical path.

Electromagnetics and Antenna Technology, Chapters 4 and 5

DTIC Science & Technology

2017-03-07

potential future application is for performing radio astronomy missions [9–16]. The antenna technology described here could be applied to other platforms...vector sensor antenna for radio astronomy [11] is depicted in the photograph shown in Figure 5.1. This electromagnetic vector Figure 5.1 Photograph of...for performing radio astronomy missions. The antenna technology described here could be applied to other platforms such as airborne vehicles, towers

14 CFR 417.303 - Command control system requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... flight termination system used for each launch. (f) Electromagnetic interference. Each command control system component must function within the electromagnetic environment to which it is exposed. A command... must prevent electromagnetic interference. (g) Command transmitter failover. A command control system...

14 CFR 417.303 - Command control system requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... flight termination system used for each launch. (f) Electromagnetic interference. Each command control system component must function within the electromagnetic environment to which it is exposed. A command... must prevent electromagnetic interference. (g) Command transmitter failover. A command control system...

14 CFR 417.303 - Command control system requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... flight termination system used for each launch. (f) Electromagnetic interference. Each command control system component must function within the electromagnetic environment to which it is exposed. A command... must prevent electromagnetic interference. (g) Command transmitter failover. A command control system...

14 CFR 417.303 - Command control system requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... flight termination system used for each launch. (f) Electromagnetic interference. Each command control system component must function within the electromagnetic environment to which it is exposed. A command... must prevent electromagnetic interference. (g) Command transmitter failover. A command control system...

14 CFR 417.303 - Command control system requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... flight termination system used for each launch. (f) Electromagnetic interference. Each command control system component must function within the electromagnetic environment to which it is exposed. A command... must prevent electromagnetic interference. (g) Command transmitter failover. A command control system...

Electromagnetically Induced Transparency in Circuit Quantum Electrodynamics with Nested Polariton States

NASA Astrophysics Data System (ADS)

Long, Junling; Ku, H. S.; Wu, Xian; Gu, Xiu; Lake, Russell E.; Bal, Mustafa; Liu, Yu-xi; Pappas, David P.

2018-02-01

Quantum networks will enable extraordinary capabilities for communicating and processing quantum information. These networks require a reliable means of storage, retrieval, and manipulation of quantum states at the network nodes. A node receives one or more coherent inputs and sends a conditional output to the next cascaded node in the network through a quantum channel. Here, we demonstrate this basic functionality by using the quantum interference mechanism of electromagnetically induced transparency in a transmon qubit coupled to a superconducting resonator. First, we apply a microwave bias, i.e., drive, to the qubit-cavity system to prepare a Λ -type three-level system of polariton states. Second, we input two interchangeable microwave signals, i.e., a probe tone and a control tone, and observe that transmission of the probe tone is conditional upon the presence of the control tone that switches the state of the device with up to 99.73% transmission extinction. Importantly, our electromagnetically induced transparency scheme uses all dipole allowed transitions. We infer high dark state preparation fidelities of >99.39 % and negative group velocities of up to -0.52 ±0.09 km /s based on our data.

Electromagnetically Induced Transparency in Circuit Quantum Electrodynamics with Nested Polariton States.

PubMed

Long, Junling; Ku, H S; Wu, Xian; Gu, Xiu; Lake, Russell E; Bal, Mustafa; Liu, Yu-Xi; Pappas, David P

2018-02-23

Quantum networks will enable extraordinary capabilities for communicating and processing quantum information. These networks require a reliable means of storage, retrieval, and manipulation of quantum states at the network nodes. A node receives one or more coherent inputs and sends a conditional output to the next cascaded node in the network through a quantum channel. Here, we demonstrate this basic functionality by using the quantum interference mechanism of electromagnetically induced transparency in a transmon qubit coupled to a superconducting resonator. First, we apply a microwave bias, i.e., drive, to the qubit-cavity system to prepare a Λ-type three-level system of polariton states. Second, we input two interchangeable microwave signals, i.e., a probe tone and a control tone, and observe that transmission of the probe tone is conditional upon the presence of the control tone that switches the state of the device with up to 99.73% transmission extinction. Importantly, our electromagnetically induced transparency scheme uses all dipole allowed transitions. We infer high dark state preparation fidelities of >99.39% and negative group velocities of up to -0.52±0.09  km/s based on our data.

High speed displacement measurement based on electro-magnetic induction applied to electromagnetically driven ring expansion

NASA Astrophysics Data System (ADS)

Han, Xiaotao; Wu, Jiawei; Huang, Lantao; Qiu, Lei; Chen, Qi; Cao, Quanliang; Herlach, Fritz; Li, Liang

2017-11-01

Investigating the mechanism of electromagnetic forming (EMF) becomes a hot topic in the field of metal forming. The high speed up to 200 m/s in EMF makes it a real challenge to capture the forming process. To this end, a new method for measuring displacement at high speed based on electromagnetic induction has been developed. Specifically this is used to measure the displacement of an expanding metal ring driven by a pulsed magnetic field; this is one of the basic EMF processes. The new method is simple and practical, and it combines high-speed response with adequate precision. The new measurement system consists of a printed circuit board (PCB) and a Rogowski probe. Eleven coaxial annular detecting probes are arranged in the PCB plate to acquire induced voltage at different positions, and a Rogowski probe is used to measure the current in the driving coil. The displacement of the ring is deduced by analyzing the output voltages of the detecting probes and the Rogowski probe. The feasibility of the method is verified by comparing the results with pictures from a high speed camera taken simultaneously.

The DESMEX Project - Deep Electromagnetic Sounding for Mineral EXploration

NASA Astrophysics Data System (ADS)

Meyer, U.; Becken, M.; Stolz, R.; Nittinger, C.; Cherevatova, M.; Siemon, B.; Martin, T.; Petersen, H.; Steuer, A.

2017-12-01

The DESMEX project (Deep Electromagnetic Sounding for Mineral Exploration) aims to develop independent semi-airborne frequency domain systems for mineral exploration down to depths of 1 km and deeper. Two different helicopter-towed systems are being designed and tested using source installations on ground. One system uses among other equipment conventional three axis induction coils, a 3D-fluxgate and a high precision inertial motion unit. The use of the two different magnetometers allows to record data in a broad frequency range from 1 Hz to 10 kHz. The second system uses a newly developed SQUID-based sensing system of a similar frequency range and a self made inertial motion unit. Horizontal electric dipole transmitters provided by the Leibniz Institute for Applied Geophysics in Hannover and the Institute of Geophysics and Meteorology of the University in Cologne are used as ground based sources. First system tests showed a good performance of both systems with general noise levels below 50 pT/root(Hz). Test flights above the common survey area proved that the desired depth of investigation can be achieved and that the data is consistent with the subsurface conductivity structures. In order to verify the data acquired from the newly developed system at shallow depths and to provide a better starting model for later inversion calculations helicopter borne frequency domain electromagnetics has been acquired and fully processed over the test site Schleiz - Greiz in Germany. To further relate the subsurface conductivity models to the subsurface geology and mineralogy, petrophysical investigations have been performed on rock samples from the site of investigation and analogue samples.

Dynamic target ionization using an ultrashort pulse of a laser field

NASA Astrophysics Data System (ADS)

Makarov, D. N.; Matveev, V. I.; Makarova, K. A.

2014-09-01

Ionization processes under the interaction of an ultrashort pulse of an electromagnetic field with atoms in nonstationary states are considered. As an example, the ionization probability of the hydrogen-like atom upon the decay of quasi-stationary state is calculated. The method developed can be applied to complex systems, including targets in collisional states and various chemical reactions.

Hadron Spectra, Decays and Scattering Properties Within Basis Light Front Quantization

NASA Astrophysics Data System (ADS)

Vary, James P.; Adhikari, Lekha; Chen, Guangyao; Jia, Shaoyang; Li, Meijian; Li, Yang; Maris, Pieter; Qian, Wenyang; Spence, John R.; Tang, Shuo; Tuchin, Kirill; Yu, Anji; Zhao, Xingbo

2018-07-01

We survey recent progress in calculating properties of the electron and hadrons within the basis light front quantization (BLFQ) approach. We include applications to electromagnetic and strong scattering processes in relativistic heavy ion collisions. We present an initial investigation into the glueball states by applying BLFQ with multigluon sectors, introducing future research possibilities on multi-quark and multi-gluon systems.

A Novel Technique Applying Spectral Estimation to Johnson Noise Thermometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ezell, N. Dianne Bull; Britton, Chuck; Ericson, Nance

Johnson noise thermometry is one of many important measurement techniques used to monitor the safety levels and stability in a nuclear reactor. However, this measurement is very dependent on the minimal electromagnetic environment. Properly removing unwanted electromagnetic interference (EMI) is critical for accurate drift-free temperature measurements. The two techniques developed by Oak Ridge National Laboratory (ORNL) to remove transient and periodic EMI are briefly discussed here. Spectral estimation is a key component in the signal processing algorithm used for EMI removal and temperature calculation. The cross-power spectral density is a key component in the Johnson noise temperature computation. Applying eithermore » technique requires the simple addition of electronics and signal processing to existing resistive thermometers. With minimal installation changes, the system discussed here can be installed on existing nuclear power plants. The Johnson noise system developed is tested at three locations: ORNL, Sandia National Laboratory, and the Tennessee Valley Authority’s Kingston Fossil Plant. Each of these locations enabled improvement on the EMI removal algorithm. Finally, the conclusions made from the results at each of these locations is discussed, as well as possible future work.« less

A Novel Technique Applying Spectral Estimation to Johnson Noise Thermometry

DOE PAGES

Ezell, N. Dianne Bull; Britton, Chuck; Ericson, Nance; ...

2018-03-30

Johnson noise thermometry is one of many important measurement techniques used to monitor the safety levels and stability in a nuclear reactor. However, this measurement is very dependent on the minimal electromagnetic environment. Properly removing unwanted electromagnetic interference (EMI) is critical for accurate drift-free temperature measurements. The two techniques developed by Oak Ridge National Laboratory (ORNL) to remove transient and periodic EMI are briefly discussed here. Spectral estimation is a key component in the signal processing algorithm used for EMI removal and temperature calculation. The cross-power spectral density is a key component in the Johnson noise temperature computation. Applying eithermore » technique requires the simple addition of electronics and signal processing to existing resistive thermometers. With minimal installation changes, the system discussed here can be installed on existing nuclear power plants. The Johnson noise system developed is tested at three locations: ORNL, Sandia National Laboratory, and the Tennessee Valley Authority’s Kingston Fossil Plant. Each of these locations enabled improvement on the EMI removal algorithm. Finally, the conclusions made from the results at each of these locations is discussed, as well as possible future work.« less

A bronchoscopic navigation system using bronchoscope center calibration for accurate registration of electromagnetic tracker and CT volume without markers.

PubMed

Luo, Xiongbiao

2014-06-01

Various bronchoscopic navigation systems are developed for diagnosis, staging, and treatment of lung and bronchus cancers. To construct electromagnetically navigated bronchoscopy systems, registration of preoperative images and an electromagnetic tracker must be performed. This paper proposes a new marker-free registration method, which uses the centerlines of the bronchial tree and the center of a bronchoscope tip where an electromagnetic sensor is attached, to align preoperative images and electromagnetic tracker systems. The chest computed tomography (CT) volume (preoperative images) was segmented to extract the bronchial centerlines. An electromagnetic sensor was fixed at the bronchoscope tip surface. A model was designed and printed using a 3D printer to calibrate the relationship between the fixed sensor and the bronchoscope tip center. For each sensor measurement that includes sensor position and orientation information, its corresponding bronchoscope tip center position was calculated. By minimizing the distance between each bronchoscope tip center position and the bronchial centerlines, the spatial alignment of the electromagnetic tracker system and the CT volume was determined. After obtaining the spatial alignment, an electromagnetic navigation bronchoscopy system was established to real-timely track or locate a bronchoscope inside the bronchial tree during bronchoscopic examinations. The electromagnetic navigation bronchoscopy system was validated on a dynamic bronchial phantom that can simulate respiratory motion with a breath rate range of 0-10 min(-1). The fiducial and target registration errors of this navigation system were evaluated. The average fiducial registration error was reduced from 8.7 to 6.6 mm. The average target registration error, which indicates all tracked or navigated bronchoscope position accuracy, was much reduced from 6.8 to 4.5 mm compared to previous registration methods. An electromagnetically navigated bronchoscopy system was constructed with accurate registration of an electromagnetic tracker and the CT volume on the basis of an improved marker-free registration approach that uses the bronchial centerlines and bronchoscope tip center information. The fiducial and target registration errors of our electromagnetic navigation system were about 6.6 and 4.5 mm in dynamic bronchial phantom validation.

A bronchoscopic navigation system using bronchoscope center calibration for accurate registration of electromagnetic tracker and CT volume without markers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Xiongbiao, E-mail: xiongbiao.luo@gmail.com

2014-06-15

Purpose: Various bronchoscopic navigation systems are developed for diagnosis, staging, and treatment of lung and bronchus cancers. To construct electromagnetically navigated bronchoscopy systems, registration of preoperative images and an electromagnetic tracker must be performed. This paper proposes a new marker-free registration method, which uses the centerlines of the bronchial tree and the center of a bronchoscope tip where an electromagnetic sensor is attached, to align preoperative images and electromagnetic tracker systems. Methods: The chest computed tomography (CT) volume (preoperative images) was segmented to extract the bronchial centerlines. An electromagnetic sensor was fixed at the bronchoscope tip surface. A model wasmore » designed and printed using a 3D printer to calibrate the relationship between the fixed sensor and the bronchoscope tip center. For each sensor measurement that includes sensor position and orientation information, its corresponding bronchoscope tip center position was calculated. By minimizing the distance between each bronchoscope tip center position and the bronchial centerlines, the spatial alignment of the electromagnetic tracker system and the CT volume was determined. After obtaining the spatial alignment, an electromagnetic navigation bronchoscopy system was established to real-timely track or locate a bronchoscope inside the bronchial tree during bronchoscopic examinations. Results: The electromagnetic navigation bronchoscopy system was validated on a dynamic bronchial phantom that can simulate respiratory motion with a breath rate range of 0–10 min{sup −1}. The fiducial and target registration errors of this navigation system were evaluated. The average fiducial registration error was reduced from 8.7 to 6.6 mm. The average target registration error, which indicates all tracked or navigated bronchoscope position accuracy, was much reduced from 6.8 to 4.5 mm compared to previous registration methods. Conclusions: An electromagnetically navigated bronchoscopy system was constructed with accurate registration of an electromagnetic tracker and the CT volume on the basis of an improved marker-free registration approach that uses the bronchial centerlines and bronchoscope tip center information. The fiducial and target registration errors of our electromagnetic navigation system were about 6.6 and 4.5 mm in dynamic bronchial phantom validation.« less

Field-programmable beam reconfiguring based on digitally-controlled coding metasurface

NASA Astrophysics Data System (ADS)

Wan, Xiang; Qi, Mei Qing; Chen, Tian Yi; Cui, Tie Jun

2016-02-01

Digital phase shifters have been applied in traditional phased array antennas to realize beam steering. However, the phase shifter deals with the phase of the induced current; hence, it has to be in the path of each element of the antenna array, making the phased array antennas very expensive. Metamaterials and/or metasurfaces enable the direct modulation of electromagnetic waves by designing subwavelength structures, which opens a new way to control the beam scanning. Here, we present a direct digital mechanism to control the scattered electromagnetic waves using coding metasurface, in which each unit cell loads a pin diode to produce binary coding states of “1” and “0”. Through data lines, the instant communications are established between the coding metasurface and the internal memory of field-programmable gate arrays (FPGA). Thus, we realize the digital modulation of electromagnetic waves, from which we present the field-programmable reflective antenna with good measurement performance. The proposed mechanism and functional device have great application potential in new-concept radar and communication systems.

Spontaneous reorientations of meta-atoms and electromagnetic spatial solitons in a liquid metacrystal.

PubMed

Zharov, Alexander A; Zharov, Alexander A; Zharova, Nina A

2014-08-01

We show that transverse electromagnetic waves propagating along an external static electric field in liquid metacrystal (LMC) can provoke spontaneous rearrangement of elongated meta-atoms that changes the direction of the anisotropy axis of the LMC. This kind of instability may reorient the meta-atoms from the equilibrium state parallel to a static field to the state along a high-frequency field and back at the different threshold intensities of electromagnetic waves in such a way that bistability in the system takes place. Reorientation of meta-atoms causes a change in the effective refraction index of LMC that creates, in turn, the conditions for the formation of bright spatial solitons. Such spatial solitons are the self-consistent domains of redirected meta-atoms with trapped photons. We find that the instability thresholds as well as energy flux captured by the spatial soliton can be easily managed by variation of the static electric field applied to the LMC. We study the effects of soliton excitation and collisions via numerical simulations.

Surface defects evaluation system based on electromagnetic model simulation and inverse-recognition calibration method

NASA Astrophysics Data System (ADS)

Yang, Yongying; Chai, Huiting; Li, Chen; Zhang, Yihui; Wu, Fan; Bai, Jian; Shen, Yibing

2017-05-01

Digitized evaluation of micro sparse defects on large fine optical surfaces is one of the challenges in the field of optical manufacturing and inspection. The surface defects evaluation system (SDES) for large fine optical surfaces is developed based on our previously reported work. In this paper, the electromagnetic simulation model based on Finite-Difference Time-Domain (FDTD) for vector diffraction theory is firstly established to study the law of microscopic scattering dark-field imaging. Given the aberration in actual optical systems, point spread function (PSF) approximated by a Gaussian function is introduced in the extrapolation from the near field to the far field and the scatter intensity distribution in the image plane is deduced. Analysis shows that both diffraction-broadening imaging and geometrical imaging should be considered in precise size evaluation of defects. Thus, a novel inverse-recognition calibration method is put forward to avoid confusion caused by diffraction-broadening effect. The evaluation method is applied to quantitative evaluation of defects information. The evaluation results of samples of many materials by SDES are compared with those by OLYMPUS microscope to verify the micron-scale resolution and precision. The established system has been applied to inspect defects on large fine optical surfaces and can achieve defects inspection of surfaces as large as 850 mm×500 mm with the resolution of 0.5 μm.

Dynamically tunable electromagnetically-induced-transparency-like resonances in graphene nanoring and nanodisk hybrid metamaterials

NASA Astrophysics Data System (ADS)

Chen, De-Chao; Li, Hong-Ju; Xia, Sheng-Xuan; Qin, Meng; Zhai, Xiang; Wang, Ling-Ling

2017-08-01

A tunable electromagnetically-induced-transparency-like (EIT-like) device is proposed numerically and theoretically in the mid-infrared region, which is composed of periodically patterned ring and disk graphene. Distinguished from the commonly used three-level system, the hybridization of the plasmon mode is applied to describing and explaining the EIT-like phenomenon in the proposed systems. What is more, further researches have revealed that the spectral position of the transparency window can be tuned not only by geometrically changing the couple distance in graphene nanostructures, but also by dynamically altering the radius of the graphene nanodisk and the chemical potential of the graphene. At the transparency window, there exist large optical delays, which can slow down the speed of light in vacuum. This work may pave the way to the development of applications including tunable sensors, slow-light devices, and optical switches.

Dynamic Modulation of Radiative Heat Transfer beyond the Blackbody Limit.

PubMed

Ito, Kota; Nishikawa, Kazutaka; Miura, Atsushi; Toshiyoshi, Hiroshi; Iizuka, Hideo

2017-07-12

Dynamic control of electromagnetic heat transfer without changing mechanical configuration opens possibilities in intelligent thermal management in nanoscale systems. We confirmed by experiment that the radiative heat transfer is dynamically modulated beyond the blackbody limit. The near-field electromagnetic heat exchange mediated by phonon-polariton is controlled by the metal-insulator transition of tungsten-doped vanadium dioxide. The functionalized heat flux is transferred over an area of 1.6 cm 2 across a 370 nm gap, which is maintained by the microfabricated spacers and applied pressure. The uniformity of the gap is validated by optical interferometry, and the measured heat transfer is well modeled as the sum of the radiative and the parasitic conductive components. The presented methodology to form a nanometric gap with functional heat flux paves the way to the smart thermal management in various scenes ranging from highly integrated systems to macroscopic apparatus.

Method and apparatus for using magneto-acoustic remanence to determine embrittlement

NASA Technical Reports Server (NTRS)

Allison, Sidney G. (Inventor); Namkung, Min (Inventor); Yost, William T. (Inventor); Cantrell, John H. (Inventor)

1992-01-01

A method and apparatus for testing steel components for temperature embrittlement uses magneto-acoustic emission to nondestructively evaluate the component are presented. Acoustic emission signals occur more frequently at higher levels in embrittled components. A pair of electromagnets are used to create magnetic induction in the test component. Magneto-acoustic emission signals may be generated by applying an AC current to the electromagnets. The acoustic emission signals are analyzed to provide a comparison between a component known to be unembrittled and a test component. Magnetic remanence is determined by applying a DC current to the electromagnets and then by turning the magnets off and observing the residual magnetic induction.

Effects of low-intensity pulsed electromagnetic fields on the early development of sea urchins.

PubMed Central

Falugi, C; Grattarola, M; Prestipino, G

1987-01-01

The effects of weak electromagnetic signals on the early development of the sea urchin Paracentrotus lividus have been studied. The duration and repetition of the pulses were similar to those used for bone healing in clinical practice. A sequence of pulses, applied for a time ranging from 2 to 4 h, accelerates the cleavages of sea urchin embryo cells. This effect can be quantitatively assessed by determining the time shifts induced by the applied electromagnetic field on the completion of the first and second cleavages in a population of fertilized eggs. The exposed embryos were allowed to develop up to the pluteus stage, showing no abnormalities. Images FIGURE 3 FIGURE 4 PMID:3607217

Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands.

PubMed

Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

2016-06-21

The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich's flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands

NASA Astrophysics Data System (ADS)

Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

2016-06-01

The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich’s flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

Electromagnetic Compatibility Design of the Computer Circuits

NASA Astrophysics Data System (ADS)

Zitai, Hong

2018-02-01

Computers and the Internet have gradually penetrated into every aspect of people’s daily work. But with the improvement of electronic equipment as well as electrical system, the electromagnetic environment becomes much more complex. Electromagnetic interference has become an important factor to hinder the normal operation of electronic equipment. In order to analyse the computer circuit compatible with the electromagnetic compatibility, this paper starts from the computer electromagnetic and the conception of electromagnetic compatibility. And then, through the analysis of the main circuit and system of computer electromagnetic compatibility problems, we can design the computer circuits in term of electromagnetic compatibility. Finally, the basic contents and methods of EMC test are expounded in order to ensure the electromagnetic compatibility of equipment.

Experimental College Physics Course Based on Ausubel's Learning Theory.

ERIC Educational Resources Information Center

Moreira, Marco Antonio

1978-01-01

Compares the Ausubelian approach and the traditional one to the content organization of an introductory course in electromagnetism. States the differences between these approaches in terms of the student's ability to apply, relate, and differentiate electromagnetic concepts. (GA)

[Personal experience in the use of magnetotherapy in diseases of the musculoskeletal system].

PubMed

Sadlonova, J; Korpas, J

1999-12-01

Therapeutic application of pulsatile electromagnetic field in disorders of motility is recently becoming more frequent. Despite this fact information about the effectiveness of this therapy in the literature are rare. The aim of this study was therefore the treatment of 576 patients who suffered from vertebral syndrome, gonarthritis and coxarthritis. For application of pulsatile electromagnetic field MTU 500H Therapy System was used. Pulsatile electromagnetic field had a frequency valve of 4.5 mT in all studied groups and magnetic induction valve 12.5-18.75 mT in the 1st group. In the 2nd group the intensity was 5.8-7.3 mT and in the 3rd group it was 7.6-11.4 mT. The time of inclination/declination in the 1st group was 20/60 ms, in the 2nd group 40/80 ms and in the 3rd group 40/90 ms. The electromagnetic field was applied during 10 days. In the 1st-3rd day during 20 minutes and in the 4th-10th day during 30 minutes. The therapy was repeated in every patient after 3 months with values of intensity higher by 50%. In the time of pulsatile electro-magnetotherapy the patients were without pharmacotherapy or other physiotherapy. The application of pulsatile electromagnetic field is a very effective therapy of vertebral syndrome, gonarthritis and coxarthritis. The results have shown that the therapy was more effective in patients suffering from gonarthrosis, than in patients with vertebral syndrome and least effective in patients with coxarthosis. Owing to regression of oedema and pain relieve the motility of patients improved. (Tab. 3, Ref. 19.)

International Symposium on Electromagnetic Compatibility, Wakefield, MA, August 20-22, 1985, Record

NASA Astrophysics Data System (ADS)

Various papers on electromagnetic compatibility are presented. The general topics addressed include: EMI transient/impulsive disturbances, electromagnetic shielding, antennas and propagation, measurement technology, anechoic chamber/open site measurements, communications systems, electrostatic discahrge, cables/transmission lines. Also considered are: elecromagnetic environments, antennas, electromagnetic pulse, nonlinear effect, computer/data transmission systems, EMI standards and requirements, enclosures/TEM cells, systems EMC, and test site measurements.

Equilibrium Shape of Ferrofluid in the Uniform External Field

DTIC Science & Technology

2017-07-14

applied external electromagnetic fields. Even in the static regimes, they demonstrate a variety of qualitative and quantitative transformations often...ellipsoidal solutions in the problems of electromagnetism , can be found in the works of Stratton,3 Landau and Lifshitz,4 and Akhiezer et al.5 Fig...controversies, the “static” approaches are much older and face less objections than the “dynamics” of electromagnetic media. This report will analyze the

Portable Electromagnetic Induction Sensor with Integrated Positioning

DTIC Science & Technology

2013-08-20

Subsurface electromagnetic induction imaging for unexploded ordnance detection. Journal of Applied Geophysics, 79:38 – 45, 2012. ISSN 09269851. URL http...Portable Electromagnetic Induction Sensor with Integrated Positioning MR-1712 Final Report Submitted to Strategic Environmental Research and...19a. NAME OF RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (include area code) Standard Form 298 (Rev. 8–98) Prescribed by ANSI Std. Z39.18 06–25–2013

Effects of stochastic time-delayed feedback on a dynamical system modeling a chemical oscillator.

PubMed

González Ochoa, Héctor O; Perales, Gualberto Solís; Epstein, Irving R; Femat, Ricardo

2018-05-01

We examine how stochastic time-delayed negative feedback affects the dynamical behavior of a model oscillatory reaction. We apply constant and stochastic time-delayed negative feedbacks to a point Field-Körös-Noyes photosensitive oscillator and compare their effects. Negative feedback is applied in the form of simulated inhibitory electromagnetic radiation with an intensity proportional to the concentration of oxidized light-sensitive catalyst in the oscillator. We first characterize the system under nondelayed inhibitory feedback; then we explore and compare the effects of constant (deterministic) versus stochastic time-delayed feedback. We find that the oscillatory amplitude, frequency, and waveform are essentially preserved when low-dispersion stochastic delayed feedback is used, whereas small but measurable changes appear when a large dispersion is applied.

Effects of stochastic time-delayed feedback on a dynamical system modeling a chemical oscillator

NASA Astrophysics Data System (ADS)

González Ochoa, Héctor O.; Perales, Gualberto Solís; Epstein, Irving R.; Femat, Ricardo

2018-05-01

We examine how stochastic time-delayed negative feedback affects the dynamical behavior of a model oscillatory reaction. We apply constant and stochastic time-delayed negative feedbacks to a point Field-Körös-Noyes photosensitive oscillator and compare their effects. Negative feedback is applied in the form of simulated inhibitory electromagnetic radiation with an intensity proportional to the concentration of oxidized light-sensitive catalyst in the oscillator. We first characterize the system under nondelayed inhibitory feedback; then we explore and compare the effects of constant (deterministic) versus stochastic time-delayed feedback. We find that the oscillatory amplitude, frequency, and waveform are essentially preserved when low-dispersion stochastic delayed feedback is used, whereas small but measurable changes appear when a large dispersion is applied.

Effect of metal shielding on a wireless power transfer system

NASA Astrophysics Data System (ADS)

Li, Jiacheng; Huang, Xueliang; Chen, Chen; Tan, Linlin; Wang, Wei; Guo, Jinpeng

2017-05-01

In this paper, the effect of non-ferromagnetic metal shielding (NFMS) material on the resonator of wireless power transfer (WPT) is studied by modeling, simulation and experimental analysis. And, the effect of NFMS material on the power transfer efficiency (PTE) of WPT systems is investigated by circuit model. Meanwhile, the effect of ferromagnetic metal shielding material on the PTE of WPT systems is analyzed through simulation. A double layer metal shield structure is designed. Experimental results demonstrate that by applying the novel double layer metal shielding method, the system PTE increases significantly while the electromagnetic field of WPT systems declines dramatically.

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

NASA Astrophysics Data System (ADS)

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.

Rashba and Dresselhaus spin-orbit couplings effects on electromagnetically induced transparency of a lens-shaped quantum dot: External electric and magnetic fields

NASA Astrophysics Data System (ADS)

Zamani, A.; Setareh, F.; Azargoshasb, T.; Niknam, E.; Mohammadhosseini, E.

2017-06-01

In this article the spin of electron as well as simultaneous effects of Rashba and Dresselhaus spin-orbit interactions are considered for a lens-shaped GaAs quantum dot and the influences of applied electric field and Zeeman effect on the electromagnetically induced transparency (EIT) of this system are investigated. To do so, the absorption, refractive index as well as the group velocity of the probe light pulse are presented and discussed. Study of the absorption and refractive index reveals that, at a particular frequency of probe field, absorption diminishes, refractive index becomes unity and so the EIT occurs. Furthermore, the investigation of group velocity show that, around such frequency the probe propagation is sub-luminal, which shifts to super-luminal for higher and lower frequencies. Our results illustrate that the EIT frequency, transparency window and sub(super)-luminal frequency intervals are strongly sensitive to applied fields in the presence of spin-orbit couplings. It is found that, in comparison with the investigations with negligence of spin, the EIT behavior under the effects of applied fields are quite different.

A convergent 2D finite-difference scheme for the Dirac–Poisson system and the simulation of graphene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brinkman, D., E-mail: Daniel.Brinkman@asu.edu; School of Mathematical and Statistical Sciences, Arizona State University, Tempe, AZ 85287; Heitzinger, C., E-mail: Clemens.Heitzinger@asu.edu

2014-01-15

We present a convergent finite-difference scheme of second order in both space and time for the 2D electromagnetic Dirac equation. We apply this method in the self-consistent Dirac–Poisson system to the simulation of graphene. The model is justified for low energies, where the particles have wave vectors sufficiently close to the Dirac points. In particular, we demonstrate that our method can be used to calculate solutions of the Dirac–Poisson system where potentials act as beam splitters or Veselago lenses.

Artificial immune system for effective properties optimization of magnetoelectric composites

NASA Astrophysics Data System (ADS)

Poteralski, Arkadiusz; Dziatkiewicz, Grzegorz

2018-01-01

The optimization problem of the effective properties for magnetoelectric composites is considered. The effective properties are determined by the semi-analytical Mori-Tanaka approach. The generalized Eshelby tensor components are calculated numerically by using the Gauss quadrature method for the integral representation of the inclusion problem. The linear magnetoelectric constitutive equation is used. The effect of orientation of the electromagnetic materials components is taken into account. The optimization problem of the design is formulated and the artificial immune system is applied to solve it.

Electromagnetic thrusters for spacecraft prime propulsion

NASA Technical Reports Server (NTRS)

Rudolph, L. K.; King, D. Q.

1984-01-01

The benefits of electromagnetic propulsion systems for the next generation of US spacecraft are discussed. Attention is given to magnetoplasmadynamic (MPD) and arc jet thrusters, which form a subset of a larger group of electromagnetic propulsion systems including pulsed plasma thrusters, Hall accelerators, and electromagnetic launchers. Mission/system study results acquired over the last twenty years suggest that for future prime propulsion applications high-power self-field MPD thrusters and low-power arc jets have the greatest potential of all electromagnetic thruster systems. Some of the benefits they are expected to provide include major reductions in required launch mass compared to chemical propulsion systems (particularly in geostationary orbit transfer) and lower life-cycle costs (almost 50 percent less). Detailed schematic drawings are provided which describe some possible configurations for the various systems.

Lorentz Force on Sodium and Chlorine Ions in a Salt Water Solution Flow under a Transverse Magnetic Field

ERIC Educational Resources Information Center

De Luca, R.

2009-01-01

It is shown that, by applying elementary concepts in electromagnetism and electrochemistry to a system consisting of salt water flowing in a thin rectangular pipe at an average velocity v[subscript A] under the influence of a transverse magnetic field B[subscript 0], an electromotive force generator can be conceived. In fact, the Lorentz force…

Research on the effect of the external magnetic field in the joule balance at NIM

NASA Astrophysics Data System (ADS)

Xu, Jinxin; You, Qiang; Li, Zhengkun; Bai, Yang; Lu, Yunfeng; Zhang, Zhonghua; He, Qing

2018-06-01

The first determination of the Planck constant with the second generation of the joule balance, NIM-2, was completed in 2017 with an uncertainty of 2.4  ×  10‑7. Due to the movement of the magnet during the measurement process, the effect of the external field is a critical problem in NIM-2. At present, the electromagnet system is used in NIM-2. By taking the average of the results with positive and negative exciting currents, the uncertainty from the external field is reduced to 1.7  ×  10‑7, which is still the largest source in the uncertainty budget as all the other items are less than 1  ×  10‑7. In the near future, a permanent magnet system will be applied in NIM-2 and the main field cannot be reversed. Although the coupling of the external magnetic field in the permanent magnet system is about 40 times less than that in the electromagnet system, further reduction of this effect is still required in the permanent magnet system. In this paper, the effect of the external field is analyzed in both an electromagnet system and a permanent magnet system based on simulations and experiments. Then, the methods of magnetic shielding and compensation coils are proposed and simulated in the permanent magnet system. The results show that it may be possible to reduce the uncertainty of the external field to less than 2  ×  10‑8 in the permanent magnet system by employing the two methods.

Shallow groundwater investigation using time-domain electromagnetic (TEM) method at Itay El-Baroud, Nile Delta, Egypt

NASA Astrophysics Data System (ADS)

Shaaban, H.; El-Qady, G.; Al-Sayed, E.; Ghazala, H.; Taha, A. I.

2016-12-01

The Nile Delta is one of the oldest known ancient delta, largest and most important depositional complex in the Mediterranean sedimentary basin. Furthermore, it is a unique site in Egypt that is suitable for accumulation and preservation of the Quaternary sediments. In this work we applied time-domain electromagnetic (TEM) method to investigate the Quaternary sediments sequence as well as detecting the groundwater aquifer in the area of study. A suite of 232 TEM sounding at 43 stations were carried out using a ;SIROTEM MK-3; time-domain electromagnetic system. A simple coincident loop configuration, in which the same loop transmits and receives signals, was employed with loop side length of 25 m. The 1-D modeling technique was applied to estimate the depth and the apparent resistivity of the interpreted geoelectrical data. Based on the interpretation of the acquired geophysical data, four geoelectric cross-sections were constructed. These sections show that the Upper Quaternary sequence consists of three geoelectric layers. The Holocene Nile mud is separated into two layers: the agricultural root zone (Layer 1) and thick water saturated mud (Layer 2). The Upper Pleistocene sandy aquifer (Layer 3) is very complicated non-linear boundary. This aquifer is the most important unit since it is considered as the main water bearing unit in the study area.

Concurrent electromagnetic scattering analysis

NASA Technical Reports Server (NTRS)

Patterson, Jean E.; Cwik, Tom; Ferraro, Robert D.; Jacobi, Nathan; Liewer, Paulett C.; Lockhart, Thomas G.; Lyzenga, Gregory A.; Parker, Jay

1989-01-01

The computational power of the hypercube parallel computing architecture is applied to the solution of large-scale electromagnetic scattering and radiation problems. Three analysis codes have been implemented. A Hypercube Electromagnetic Interactive Analysis Workstation was developed to aid in the design and analysis of metallic structures such as antennas and to facilitate the use of these analysis codes. The workstation provides a general user environment for specification of the structure to be analyzed and graphical representations of the results.

On the estimation of heating effects in the atmosphere because of seismic activities

NASA Astrophysics Data System (ADS)

Meister, Claudia-Veronika; Hoffmann, Dieter H. H.

2014-05-01

The dielectric model for waves in the Earth's ionosphere is further developed and applied to possible electro-magnetic phenomena in seismic regions. In doing so, in comparison to the well-known dielectric wave model by R.O. Dendy [Plasma dynamics, Oxford University Press, 1990] for homogeneous systems, the stratification of the atmosphere is taken into account. Moreover, within the frame of many-fluid magnetohydrodynamics also the momentum transfer between the charged and neutral particles is considered. Discussed are the excitation of Alfvén and magnetoacoustic waves, but also their variations by the neutral gas winds. Further, also other current driven waves like Farley-Buneman ones are studied. In the work, models of the altitudinal scales of the plasma parameters and the electromagnetic wave field are derived. In case of the electric wave field, a method is given to calculate the altitudinal scale based on the Poisson equation for the electric field and the magnetohydrodynamic description of the particles. Further, expressions are derived to estimate density, pressure, and temperatur changes in the E-layer because of the generation of the electromagnetic waves. Last not least, formulas are obtained to determine the dispersion and polarisation of the excited electromagnetic waves. These are applied to find quantitative results for the turbulent heating of the ionospheric E-layer. Concerning the calculation of the dispersion relation, in comparison to a former work by Meister et al. [Contr. Plasma Phys. 53 (4-5), 406-413, 2013], where a numerical double-iteration method was suggested to obtain results for the wave dispersion relations, now further analytical calculations are performed. In doing so, different polynomial dependencies of the wave frequencies from the wave vectors are treated. This helped to restrict the numerical calculations to only one iteration process.

Gravitational scattering of electromagnetic radiation

NASA Technical Reports Server (NTRS)

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.

SYSTEMS FOR EXPOSING MICE TO 2,450-MHZ ELECTROMAGNETIC FIELDS

EPA Science Inventory

Two systems for exposing mice to 2,450-MHz electromagnetic fields are described. In a waveguide system, four mice were placed in a Styrofoam cage and exposed dorsally to circularly polarized electromagnetic fields. The temperature and humidity in the mouse holder were kept consta...

Array analysis of electromagnetic radiation from radio transmitters for submarine communication

NASA Astrophysics Data System (ADS)

Füllekrug, Martin; Mezentsev, Andrew; Watson, Robert; Gaffet, Stéphane; Astin, Ivan; Evans, Adrian

2014-12-01

The array analyses used for seismic and infrasound research are adapted and applied here to the electromagnetic radiation from radio transmitters for submarine communication. It is found that the array analysis enables a determination of the slowness and the arrival azimuth of the wave number vectors associated with the electromagnetic radiation. The array analysis is applied to measurements of ˜20-24 kHz radio waves from transmitters for submarine communication with an array of 10 radio receivers distributed over an area of ˜1 km ×1 km. The observed slowness of the observed wave number vectors range from ˜2.7 ns/m to ˜4.1 ns/m, and the deviations between the expected arrival azimuths and the observed arrival azimuths range from ˜-9.7° to ˜14.5°. The experimental results suggest that it is possible to determine the locations of radio sources from transient luminous events above thunderclouds with an array of radio receivers toward detailed investigations of the electromagnetic radiation from sprites.

Microfabricated sensors for the measurement of electromagnetic fields in biological tissues

NASA Astrophysics Data System (ADS)

Monberg, James; Henning, Albert K.

1995-09-01

Public awareness of the risks of exposure to electromagnetic radiation has grown over the past ten yeras. The effects of power lines on human and animal health have drawn particular attention. Some longitudinal studies of cancer rates near power lines show a significant correlation, while others show a null result. The studies have suffered from inadequate sensors for the measurement of electromagnetic radiation in vivo. In this work, we describe the design, construction, and testing of electrically passive, microfabricated single-pole antennas and coils. These sensors will be used in vivo to study the effects of electromagnetic radiation on animals. Our testing to date has been limited to in vitro studies of the magnetic field probes. Magnetic field pickup coils were fabricated with up to 100 turns, over a length of up to 1000 micrometers . Measurements were carried out with the sensors in air, and in water of various saline concentrations. Magnetic fields were applied using a Helmholtz coil. Both dc and ac fields were applied. The results indicate that small-area measurements of electromagnetic fields in vitro can be made successfully, provided adequate shielding and amplification are used.

Nanomechanical electric and electromagnetic field sensor

DOEpatents

Datskos, Panagiotis George; Lavrik, Nickolay

2015-03-24

The present invention provides a system for detecting and analyzing at least one of an electric field and an electromagnetic field. The system includes a micro/nanomechanical oscillator which oscillates in the presence of at least one of the electric field and the electromagnetic field. The micro/nanomechanical oscillator includes a dense array of cantilevers mounted to a substrate. A charge localized on a tip of each cantilever interacts with and oscillates in the presence of the electric and/or electromagnetic field. The system further includes a subsystem for recording the movement of the cantilever to extract information from the electric and/or electromagnetic field. The system further includes a means of adjusting a stiffness of the cantilever to heterodyne tune an operating frequency of the system over a frequency range.

Motivating Non-science Majors: The Technology of Electromagnetic Waves

NASA Astrophysics Data System (ADS)

Henrich, Victor E.

2018-01-01

To address the need for physics courses that stimulate non-STEM majors' interest in, and appreciation of, science, the Department of Applied Physics has developed a popular course for Yale College undergraduates, The Technological World, that explains the physics behind technologies that students use every day. The course provides an in-depth development of electromagnetic waves, applying them to technologies as diverse as LCD displays, GPS, fiber optics, CAT scans, LEDs, and stealth aircraft. It utilizes a conventional lecture format, with many in-class demonstrations.

The argument for a unified approach to non-ionizing radiation protection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perala, R.A.; Rigden, G.J.; Pfeffer, R.A.

1993-12-01

In the next decade military equipment will be required to operate in severe electromagnetic environments. These environments are expected to contain most non-ionizing frequencies (D.C. to GHz), from hostile and/or non-hostile sources, and be severe enough to cause temporary upset or even catastrophic failure of electronic equipment. Over the past thirty years considerable emphasis has been placed on hardening critical systems to one or more of these non-ionizing radiation environments, the most prevalent being the nuclear-induced electromagnetic pulse (EMD). From this technology development there has evolved a hardening philosophy that applies to most of these non-ionizing radiation environments. The philosophy,more » which stresses the application of zonal shields plus penetration protection, can provide low-cost hardening against such diverse non-ionizing radiation as p-static, lightning, electromagnetic interference (EMI), EMP, high intensity radiated fields (HIRF), electromagnetic radiation (EMR), and high power microwaves (HPM). The objective in this paper is to describe the application of this philosophy to Army helicopters. The authors develop a unified specification complete with threat definitions and test methods which illustrates integration of EMP, lightning, and HIRF at the box qualification level. This paper is a summary of the effort documented in a cited reference.« less

An electromagnetic microvalve for pneumatic control of microfluidic systems.

PubMed

Liu, Xuling; Li, Songjing

2014-10-01

An electromagnetic microvalve for pneumatic control of microfluidic devices has been designed, fabricated, and tested. The microvalve is composed of two parts: a miniature electromagnetic actuator and a valve body. The electromagnetic actuator consists mainly of a thin polydimethylsiloxane (PDMS)-based elastomer, which acts as the valve diaphragm. The diaphragm, used as a solid hydraulic medium, converts the large contact area of a valve core into a small contact area of valve head while maintaining a large stroking force. This microvalve remains closed because of a compressed mechanical spring force generated by the actuator. On the other hand, when a voltage is applied, the valve core moves up, relaxing the thin PDMS membrane, opening the microvalve. The fast open response (~17 ms) of the valve was achieved with a leak rate as low as 0.026 sccm at 200 KPa (N2) pressure. We tested the pertinent dynamic parameters such as flow rate in on/off mode, flow rate of duty cycles, and actuated frequencies in pulse width modulation (PWM) mode. Our method provides a simple, cheap, and small microvalve that avoids the bulky and expensive external pressure control solenoid manifold. This allows it to be easily integrated into portable and disposable devices. © 2014 Society for Laboratory Automation and Screening.

Interaction of Low Frequency External Electric Fields and Pancreatic β-Cell: A Mathematical Modeling Approach to Identify the Influence of Excitation Parameters.

PubMed

Farashi, Sajjad; Sasanpour, Pezhman; Rafii-Tabar, Hashem

2018-05-24

Purpose-Although the effect of electromagnetic fields on biological systems has attracted attraction in recent years, there has not been any conclusive result concerning the effects of interaction and the underlying mechanisms involved. Besides the complexity of biological systems, the parameters of the applied electromagnetic field have not been estimated in most of the experiments. Material and Method-In this study, we have used computational approach in order to find the excitation parameters of an external electric field which produces sensible effects in the function of insulin secretory machinery, whose failure triggers the diabetes disease. A mathematical model of the human β-cell has been used and the effects of external electric fields with different amplitudes, frequencies and wave shapes have been studied. Results-The results from our simulations show that the external electric field can influence the membrane electrical activity and perhaps the insulin secretion when its amplitude exceeds a threshold value. Furthermore, our simulations reveal that different waveforms have distinct effects on the β-cell membrane electrical activity and the characteristic features of the excitation like frequency would change the interaction mechanism. Conclusion-The results could help the researchers to investigate the possible role of the environmental electromagnetic fields on the promotion of diabetes disease.

Positioning and Microvibration Control by Electromagnets of an Air Spring Vibration Isolation System

NASA Technical Reports Server (NTRS)

Watanabe, Katsuhide; Cui, Weimin; Haga, Takahide; Kanemitsu, Yoichi; Yano, Kenichi

1996-01-01

Active positioning and microvibration control has been attempted by electromagnets equipped in a bellows-type, air-spring vibration isolation system. Performance tests have been carried out to study the effects. The main components of the system's isolation table were four electromagnetic actuators and controllers. The vibration isolation table was also equipped with six acceleration sensors for detecting microvibration of the table. The electromagnetic actuators were equipped with bellows-type air springs for passive support of the weight of the item placed on the table, with electromagnets for active positioning, as well as for microvibration control, and relative displacement sensors. The controller constituted a relative feedback system for positioning control and an absolute feedback system for vibration isolation control. In the performance test, a 1,490 kg load (net weight of 1,820 kg) was placed on the vibration isolation table, and both the positioning and microvibration control were carried out electromagnetically. Test results revealed that the vibration transmission was reduced by 95%.

Study on processing immiscible materials in zero gravity

NASA Technical Reports Server (NTRS)

Reger, J. L.; Mendelson, R. A.

1975-01-01

An experimental investigation was conducted to evaluate mixing immiscible metal combinations under several process conditions. Under one-gravity, these included thermal processing, thermal plus electromagnetic mixing, and thermal plus acoustic mixing. The same process methods were applied during free fall on the MSFC drop tower facility. The design is included of drop tower apparatus to provide the electromagnetic and acoustic mixing equipment, and a thermal model was prepared to design the specimen and cooling procedure. Materials systems studied were Ca-La, Cd-Ga and Al-Bi; evaluation of the processed samples included the morphology and electronic property measurements. The morphology was developed using optical and scanning electron microscopy and microprobe analyses. Electronic property characterization of the superconducting transition temperatures were made using an impedance change-tuned coil method.

High order volume-preserving algorithms for relativistic charged particles in general electromagnetic fields

NASA Astrophysics Data System (ADS)

He, Yang; Sun, Yajuan; Zhang, Ruili; Wang, Yulei; Liu, Jian; Qin, Hong

2016-09-01

We construct high order symmetric volume-preserving methods for the relativistic dynamics of a charged particle by the splitting technique with processing. By expanding the phase space to include the time t, we give a more general construction of volume-preserving methods that can be applied to systems with time-dependent electromagnetic fields. The newly derived methods provide numerical solutions with good accuracy and conservative properties over long time of simulation. Furthermore, because of the use of an accuracy-enhancing processing technique, the explicit methods obtain high-order accuracy and are more efficient than the methods derived from standard compositions. The results are verified by the numerical experiments. Linear stability analysis of the methods shows that the high order processed method allows larger time step size in numerical integrations.

Generation and control of optical frequency combs using cavity electromagnetically induced transparency

NASA Astrophysics Data System (ADS)

Li, Jiahua; Qu, Ye; Yu, Rong; Wu, Ying

2018-02-01

We explore theoretically the generation and all-optical control of optical frequency combs (OFCs) in photon transmission based on a combination of single-atom-cavity quantum electrodynamics (CQED) and electromagnetically induced transparency (EIT). Here an external control field is used to form the cavity dark mode of the CQED system. When the strengths of the applied EIT control field are appropriately tuned, enhanced comb generation can be achieved. We discuss the properties of the dark mode and clearly show that the formation of the dark mode enables the efficient generation of OFCs. In our approach, the comb spacing is determined by the beating frequency between the driving pump and seed lasers. Our demonstrated theory may pave the way towards all-optical coherent control of OFCs using a CQED architecture.

The Electromagnetic Impact of Wind Turbines

DTIC Science & Technology

2015-07-06

Applied Project 4. TITLE AND SUBTITLE THE ELECTROMAGNETIC IMPACT OF WIND TURBINES 5. FUNDING NUMBERS 6. AUTHOR(S) Gregory Sasarita and Charles R...DISTRIBUTION CODE A 13. ABSTRACT (maximum 200 words) The objective of this project was to investigate the impact that a wind turbine can have on

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

NASA Astrophysics Data System (ADS)

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.

49 CFR 238.425 - Electrical system.

Code of Federal Regulations, 2013 CFR

2013-10-01

... insulated from the supports that hold them. (d) Electromagnetic interference and compatibility. (1) The operating railroad shall ensure electromagnetic compatibility of the safety-critical equipment systems with their environment. Electromagnetic compatibility can be achieved through equipment design or changes to...

49 CFR 238.425 - Electrical system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... insulated from the supports that hold them. (d) Electromagnetic interference and compatibility. (1) The operating railroad shall ensure electromagnetic compatibility of the safety-critical equipment systems with their environment. Electromagnetic compatibility can be achieved through equipment design or changes to...

49 CFR 238.425 - Electrical system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... insulated from the supports that hold them. (d) Electromagnetic interference and compatibility. (1) The operating railroad shall ensure electromagnetic compatibility of the safety-critical equipment systems with their environment. Electromagnetic compatibility can be achieved through equipment design or changes to...

49 CFR 238.225 - Electrical system.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., and the frames shall be electrically insulated from the supports that hold them. (d) Electromagnetic interference and compatibility. (1) The operating railroad shall ensure electromagnetic compatibility of the safety-critical equipment systems with their environment. Electromagnetic compatibility may be achieved...

49 CFR 238.425 - Electrical system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... insulated from the supports that hold them. (d) Electromagnetic interference and compatibility. (1) The operating railroad shall ensure electromagnetic compatibility of the safety-critical equipment systems with their environment. Electromagnetic compatibility can be achieved through equipment design or changes to...

49 CFR 238.225 - Electrical system.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., and the frames shall be electrically insulated from the supports that hold them. (d) Electromagnetic interference and compatibility. (1) The operating railroad shall ensure electromagnetic compatibility of the safety-critical equipment systems with their environment. Electromagnetic compatibility may be achieved...

49 CFR 238.225 - Electrical system.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., and the frames shall be electrically insulated from the supports that hold them. (d) Electromagnetic interference and compatibility. (1) The operating railroad shall ensure electromagnetic compatibility of the safety-critical equipment systems with their environment. Electromagnetic compatibility may be achieved...

49 CFR 238.225 - Electrical system.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., and the frames shall be electrically insulated from the supports that hold them. (d) Electromagnetic interference and compatibility. (1) The operating railroad shall ensure electromagnetic compatibility of the safety-critical equipment systems with their environment. Electromagnetic compatibility may be achieved...

49 CFR 238.225 - Electrical system.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., and the frames shall be electrically insulated from the supports that hold them. (d) Electromagnetic interference and compatibility. (1) The operating railroad shall ensure electromagnetic compatibility of the safety-critical equipment systems with their environment. Electromagnetic compatibility may be achieved...

49 CFR 238.425 - Electrical system.

Code of Federal Regulations, 2011 CFR

2011-10-01

... insulated from the supports that hold them. (d) Electromagnetic interference and compatibility. (1) The operating railroad shall ensure electromagnetic compatibility of the safety-critical equipment systems with their environment. Electromagnetic compatibility can be achieved through equipment design or changes to...

Study on the electromagnetic radiation characteristics of discharging excimer laser system

NASA Astrophysics Data System (ADS)

Zhao, Duliang; Liang, Xu; Fang, Xiaodong; Wang, Qingsheng

2016-10-01

Excimer laser in condition of high voltage, large current and fast discharge will produce strong electromagnetic pulse radiation and electromagnetic interference on the around electrical equipment. The research on characteristics and distribution of excimer laser electromagnetic radiation could provide important basis for electromagnetic shielding and suppressing electromagnetic interference, and further improving the electromagnetic compatibility of system. Firstly, electromagnetic radiation source is analyzed according to the working principle of excimer laser. The key test points of the electromagnetic radiation, hydrogen thyratron, main discharge circuit and laser outlet, are determined by the mechanical structure and the theory of electromagnetic radiation. Secondly, characteristics of electromagnetic field were tested using a near field probe on the key positions of the vertical direction at 20, 50, and 80 cm, respectively. The main radiation frequencies and the radiation field characteristics in the near field are obtained. The experimental results show that the main radiation frequencies distribute in 47, 65, and 130 MHz for electric field and the main radiation frequencies distribute in 34, 100, and 165 MHz for magnetic field. The intensity of electromagnetic field decreases rapidly with the increase of test distance. The higher the frequency increases, the faster the amplitude attenuate. Finally, several electromagnetic interference suppression measurement methods are proposed from the perspective of electromagnetic compatibility according to the test results.

Integrated Analysis of Piezoelectric Resonators as Components of Electronic Systems

DTIC Science & Technology

2015-09-07

Transient thickness-shear vibration of apiezoelectric plate of monoclinic crystals, International Journal of Applied Electromagnetics and Mechanics 38...52, 1461-1467 (2005)., (04 2012): 811. doi: N Liu, J S Yang, F Jin. Transient thickness-shear vibration of a piezoelectric plate of monoclinic...2012) 27–37, (02 2012): 27. doi: Zhi Wang, Minghao Zhao, Jiashi Yang. Amplitude evolution equation and transient effects in piezoelectric crystal

A hybrid power system for unmanned aerial vehicle electromagnetic launcher

NASA Astrophysics Data System (ADS)

Wang, Zhiren; Wu, Jun; Huang, Shengjun

2018-06-01

According to the UAV electromagnetic catapult with fixed timing, a hybrid energy storage system consist with battery and super capacitor is designed, in order to reduce the volume and weight of the energy storage system. The battery is regarded as the energy storage device and the super capacitor as power release device. Firstly, the battery charges the super capacitor, and then the super capacitor supplies power to electromagnetic catapult separately. The strategy is using the Buck circuit to charge the super capacitor with constant current and using the Boost circuit to make super capacitor provide a stable voltage circuit for electromagnetic catapult. The Simulink simulation results show that the designed hybrid energy storage system can meet the requirements of electromagnetic catapult. Compared with the system powered by the battery alone, the proposed scheme can reduce the number of batteries, and greatly reduce the volume and weight of the energy storage system.

Cervical Spine Mechanism for Reproduction of the Biomechanical Behaviours of the Human Neck during Rotation-Traction Manipulation

PubMed Central

Zhu, Liguo

2017-01-01

Rotation-traction (RT) manipulation is a commonly used physical therapy procedure in TCM (traditional Chinese medicine) for cervical spondylosis. This procedure temporarily separates the C3 and C4 cervical vertebrae from each other when a physician applies a jerky action while the neck is voluntarily turned by the patient to a specific position as instructed by the physician, where the cervical vertebrae are twisted and locked. However, a high rate of cervical injury occurs due to inexperienced physician interns who lack sufficient training. Therefore, we developed a cervical spine mechanism that imitates the dynamic behaviours of the human neck during RT manipulation. First, in vivo and in vitro experiments were performed to acquire the biomechanical feature curves of the human neck during RT manipulation. Second, a mass-spring-damper system with an electromagnetic clutch was designed to emulate the entire dynamic response of the human neck. In this system, a spring is designed as rectilinear and nonlinear to capture the viscoelasticity of soft tissues, and an electromagnetic clutch is used to simulate the sudden disengagement of the cervical vertebrae. Test results show that the mechanism can exhibit the desired behaviour when RT manipulation is applied in the same manner as on humans. PMID:29259395

Recognition of isotropic plane target from RCS diagram

NASA Astrophysics Data System (ADS)

Saillard, J.; Chassay, G.

1981-06-01

The use of electromagnetic waves for the recognition of a structure represented by point scatterers is seen as posing a fundamental problem. It is noted that much research has been done on this subject and that the study of aircraft observed in the yaw plane gives interesting results. To apply these methods, however, it is necessary to use many sophisticated acquisition systems. A method is proposed which can be applied to plane structures composed of isotropic scatterers. The method is considered to be of interest because it uses only power measurements and requires only a classical tracking radar.

Vertical electromagnetic profiling (VEMP)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lytle, R.J.

1984-08-01

Vertical seismic profiling (VSP) is based upon reception measurements performed in a borehole with a source near the ground surface. This technology has seen a surge in application and development in the last decade. The analogous concept of vertical electromagnetic profiling (VEMP) consists of reception measurements performed in a borehole with a source near the ground surface. Although the electromagnetic concept has seen some application, this technology has not been as systematically developed and applied as VSP. Vertical electromagnetic profiling provides distinct and complementary data due to sensing different physical parameters than seismic profiling. Certain of the advantages of VEMPmore » are presented. 28 references, 7 figures.« less

An Optimization System with Parallel Processing for Reducing Common-Mode Current on Electronic Control Unit

NASA Astrophysics Data System (ADS)

Okazaki, Yuji; Uno, Takanori; Asai, Hideki

In this paper, we propose an optimization system with parallel processing for reducing electromagnetic interference (EMI) on electronic control unit (ECU). We adopt simulated annealing (SA), genetic algorithm (GA) and taboo search (TS) to seek optimal solutions, and a Spice-like circuit simulator to analyze common-mode current. Therefore, the proposed system can determine the adequate combinations of the parasitic inductance and capacitance values on printed circuit board (PCB) efficiently and practically, to reduce EMI caused by the common-mode current. Finally, we apply the proposed system to an example circuit to verify the validity and efficiency of the system.

Impact of Electromagnetic Field upon Temperature Measurement of Induction Heated Charges

NASA Astrophysics Data System (ADS)

Smalcerz, A.; Przylucki, R.

2013-04-01

The use of thermoelements is a commonly applied method in industry and engineering. It provides a wide measurement range of temperature, a direct voltage signal from the transducer, low cost of the thermoelement, and its resistance to many unfavorable factors which occur in an industrial environment. Unfortunately, thermoelements may not be resistant to interferences of a strong electromagnetic field because of the nature and design of a transducer. Induction heating is the most commonly used type of heating, at present, for metals. In order to guarantee the correctness of the carried out heating process, it is essential to control the temperature of the heated element. The impact of a strong electromagnetic field upon the thermocouple temperature measurement of the inductively heated elements has been analyzed in this paper. The experiment includes dozens of measurements where the following parameters have been varied: frequency of the current which feeds the heating inductor, power supplied to the heating system, geometry of heat inductor, and the charge material and its geometrical dimensions. Interferences of the power-line frequency have been eliminated in part of the carried out measurements.

3-D Forward modeling of Induced Polarization Effects of Transient Electromagnetic Method

NASA Astrophysics Data System (ADS)

Wu, Y.; Ji, Y.; Guan, S.; Li, D.; Wang, A.

2017-12-01

In transient electromagnetic (TEM) detection, Induced polarization (IP) effects are so important that they cannot be ignored. The authors simulate the three-dimensional (3-D) induced polarization effects in time-domain directly by applying the finite-difference time-domain method (FDTD) based on Cole-Cole model. Due to the frequency dispersion characteristics of the electrical conductivity, the computations of convolution in the generalized Ohm's law of fractional order system makes the forward modeling particularly complicated. Firstly, we propose a method to approximate the fractional order function of Cole-Cole model using a lower order rational transfer function based on error minimum theory in the frequency domain. In this section, two auxiliary variables are introduced to transform nonlinear least square fitting problem of the fractional order system into a linear programming problem, thus avoiding having to solve a system of equations and nonlinear problems. Secondly, the time-domain expression of Cole-Cole model is obtained by using Inverse Laplace transform. Then, for the calculation of Ohm's law, we propose an e-index auxiliary equation of conductivity to transform the convolution to non-convolution integral; in this section, the trapezoid rule is applied to compute the integral. We then substitute the recursion equation into Maxwell's equations to derive the iterative equations of electromagnetic field using the FDTD method. Finally, we finish the stimulation of 3-D model and evaluate polarization parameters. The results are compared with those obtained from the digital filtering solution of the analytical equation in the homogeneous half space, as well as with the 3-D model results from the auxiliary ordinary differential equation method (ADE). Good agreements are obtained across the three methods. In terms of the 3-D model, the proposed method has higher efficiency and lower memory requirements as execution times and memory usage were reduced by 20% compared with ADE method.

Absorption coefficient and relative refractive index change for a double δ-doped GaAs MIGFET-like structure: Electric and magnetic field effects

NASA Astrophysics Data System (ADS)

Martínez-Orozco, J. C.; Rodríguez-Magdaleno, K. A.; Suárez-López, J. R.; Duque, C. A.; Restrepo, R. L.

2016-04-01

In this work we present theoretical results for the electronic structure as well as for the absorption coefficient and relative refractive index change for an asymmetric double δ-doped like confining potential in the active region of a Multiple Independent Gate Field Effect Transistor (MIGFET) system. We model the potential profile as a double δ-doped like potential profile between two Schottky (parabolic) potential barriers that are just the main characteristics of the MIGFET configuration. We investigate the effect of external electromagnetic fields in this kind of quantum structures, in particular we applied a homogeneous constant electric field in the growth direction z as well as a homogeneous constant magnetic field in the x-direction. In general we conclude that by applying electromagnetic fields we can modulate the resonant peaks of the absorption coefficient as well as their energy position. Also with such probes it is possible to control the nodes and amplitude of the relative refractive index changes related to resonant intersubband optical transitions.

Design and analysis of an electromagnetic turnout for the superconducting Maglev system

NASA Astrophysics Data System (ADS)

Li, Y. J.; Dai, Q.; Zhang, Y.; Wang, H.; Chen, Z.; Sun, R. X.; Zheng, J.; Deng, C. Y.; Deng, Z. G.

2016-09-01

Turnout is a crucial track junction device of the ground rail transportation system. For high temperature superconducting (HTS) Maglev system, the permanent magnet guideway (PMG) makes the strong magnetic force existing between rail segments, which may cause moving difficulties and increase the operation cost when switching a PMG. In this paper, a non-mechanical 'Y' shaped Halbach-type electromagnetic turnout was proposed. By replacing the PMs with electromagnets, the turnout can guide the maglev vehicle running into another PMG by simply controlling the current direction of electromagnets. The material and structure parameters of the electromagnets were optimized by simulation. The results show that the optimized electromagnet can keep the magnetic field above it as strong as the PMs', meanwhile feasible for design and manufacture. This work provides valuable references for the future design in non-mechanical PMG turnout.

Limits on new forces coexisting with electromagnetism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kloor, H.; Fischbach, E.; Talmadge, C.

1994-02-15

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

Investigation of coastal areas in Northern Germany using airborne geophysical surveys

NASA Astrophysics Data System (ADS)

Miensopust, Marion; Siemon, Bernhard; Wiederhold, Helga; Steuer, Annika; Ibs-von Seht, Malte; Voß, Wolfgang; Meyer, Uwe

2014-05-01

Since 2000, the German Federal Institute for Geosciences and Natural Resources (BGR) carried out several airborne geophysical surveys in Northern Germany to investigate the coastal areas of the North Sea and some of the North and East Frisian Islands. Several of those surveys were conducted in cooperation with the Leibniz Institute for Applied Geophysics (LIAG). Two helicopter-borne geophysical systems were used, namely the BGR system, which collects simultaneously frequency-domain electromagnetic, magnetic and radiometric data, and the SkyTEM system, a time-domain electromagnetic system developed by the University of Aarhus. Airborne geophysical surveys enable to investigate huge areas almost completely with high lateral resolution in a relatively short time at economic cost. In general, the results can support geological and hydrogeological mapping. Of particular importance are the airborne electromagnetic results, as the surveyed parameter - the electrical conductivity - depends on both lithology and groundwater status. Therefore, they can reveal buried valleys and the distribution of sandy and clayey sediments as well as salinization zones and fresh-water occurrences. The often simultaneously recorded magnetic and radiometric data support the electromagnetic results. Lateral changes of Quaternary and Tertiary sediments (shallow source - several tens of metres) as well as evidences of the North German Basin (deep source - several kilometres) are revealed by the magnetic results. The radiometric data indicate the various mineral compositions of the soil sediments. This BGR/LIAG project aims to build up a geophysics data base (http://geophysics-database.de/) which contains all airborne geophysical data sets. However, the more significant effort is to create a reference data set as basis for monitoring climate or man-made induced changes of the salt-water/fresh-water interface at the German North Sea coast. The significance of problems for groundwater extraction and treatment caused by groundwater salinization is more and more increasing and particularly coastal areas are affected by a latent risk for the sustainable usage of aquifers.

High Bandwidth Rotary Fast Tool Servos and a Hybrid Rotary/Linear Electromagnetic Actuator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montesanti, Richard Clement

2005-09-01

This thesis describes the development of two high bandwidth short-stroke rotary fast tool servos and the hybrid rotary/linear electromagnetic actuator developed for one of them. Design insights, trade-o® methodologies, and analytical tools are developed for precision mechanical systems, power and signal electronic systems, control systems, normal-stress electromagnetic actuators, and the dynamics of the combined systems.

Underwater Advanced Time-Domain Electromagnetic System

DTIC Science & Technology

2017-03-01

distribution statement initially submitted with AD1042986, entitled Underwater Advanced Time Domain Electromagnetic System (MR-201313), has been appealed...Advanced Time -Domain Electromagnetic System ESTCP Project MR-201313 MARCH 2017 Mr. Steve Saville CH2M Distribution Statement D: Distribution...is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and

Treatment of winery wastewater by electrochemical methods and advanced oxidation processes.

PubMed

Orescanin, Visnja; Kollar, Robert; Nad, Karlo; Mikelic, Ivanka Lovrencic; Gustek, Stefica Findri

2013-01-01

The aim of this research was development of new system for the treatment of highly polluted wastewater (COD = 10240 mg/L; SS = 2860 mg/L) originating from vine-making industry. The system consisted of the main treatment that included electrochemical methods (electro oxidation, electrocoagulation using stainless steel, iron and aluminum electrode sets) with simultaneous sonication and recirculation in strong electromagnetic field. Ozonation combined with UV irradiation in the presence of added hydrogen peroxide was applied for the post-treatment of the effluent. Following the combined treatment, the final removal efficiencies of the parameters color, turbidity, suspended solids and phosphates were over 99%, Fe, Cu and ammonia approximately 98%, while the removal of COD and sulfates was 77% and 62%, respectively. A new approach combining electrochemical methods with ultrasound in the strong electromagnetic field resulted in significantly better removal efficiencies for majority of the measured parameters compared to the biological methods, advanced oxidation processes or electrocoagulation. Reduction of the treatment time represents another advantage of this new approach.

Invisibility problem in acoustics, electromagnetism and heat transfer. Inverse design method

NASA Astrophysics Data System (ADS)

Alekseev, G.; Tokhtina, A.; Soboleva, O.

2017-10-01

Two approaches (direct design and inverse design methods) for solving problems of designing devices providing invisibility of material bodies of detection using different physical fields - electromagnetic, acoustic and static are discussed. The second method is applied for solving problems of designing cloaking devices for the 3D stationary thermal scattering model. Based on this method the design problems under study are reduced to respective control problems. The material parameters (radial and tangential heat conductivities) of the inhomogeneous anisotropic medium filling the thermal cloak and the density of auxiliary heat sources play the role of controls. A unique solvability of direct thermal scattering problem in the Sobolev space is proved and the new estimates of solutions are established. Using these results, the solvability of control problem is proved and the optimality system is derived. Based on analysis of optimality system, the stability estimates of optimal solutions are established and numerical algorithms for solving particular thermal cloaking problem are proposed.

Development and program implementation of elements for identification of the electromagnet condition for movable element position control

NASA Astrophysics Data System (ADS)

Leukhin, R. I.; Shaykhutdinov, D. V.; Shirokov, K. M.; Narakidze, N. D.; Vlasov, A. S.

2017-02-01

Developing the experimental design of new electromagnetic constructions types in engineering industry enterprises requires solutions of two major problems: regulator’s parameters setup and comprehensive testing of electromagnets. A weber-ampere characteristic as a data source for electromagnet condition identification was selected. Present article focuses on development and implementation of the software for electromagnetic drive control system based on the weber-ampere characteristic measuring. The software for weber-ampere characteristic data processing based on artificial neural network is developed. Results of the design have been integrated into the program code in LabVIEW environment. The license package of LabVIEW graphic programming was used. The hardware is chosen and possibility of its use for control system implementation was proved. The trained artificial neural network defines electromagnetic drive effector position with minimal error. Developed system allows to control the electromagnetic drive powered by the voltage source, the current source and hybrid sources.

Natural time analysis of critical phenomena: The case of pre-fracture electromagnetic emissions

NASA Astrophysics Data System (ADS)

Potirakis, S. M.; Karadimitrakis, A.; Eftaxias, K.

2013-06-01

Criticality of complex systems reveals itself in various ways. One way to monitor a system at critical state is to analyze its observable manifestations using the recently introduced method of natural time. Pre-fracture electromagnetic (EM) emissions, in agreement to laboratory experiments, have been consistently detected in the MHz band prior to significant earthquakes. It has been proposed that these emissions stem from the fracture of the heterogeneous materials surrounding the strong entities (asperities) distributed along the fault, preventing the relative slipping. It has also been proposed that the fracture of heterogeneous material could be described in analogy to the critical phase transitions in statistical physics. In this work, the natural time analysis is for the first time applied to the pre-fracture MHz EM signals revealing their critical nature. Seismicity and pre-fracture EM emissions should be two sides of the same coin concerning the earthquake generation process. Therefore, we also examine the corresponding foreshock seismic activity, as another manifestation of the same complex system at critical state. We conclude that the foreshock seismicity data present criticality features as well.

Sensing mode atomic force microscope

DOEpatents

Hough, Paul V. C.; Wang, Chengpu

2003-01-01

An atomic force microscope utilizes a pulse release system and improved method of operation to minimize contact forces between a probe tip affixed to a flexible cantilever and a specimen being measured. The pulse release system includes a magnetic particle affixed proximate the probe tip and an electromagnetic coil. When energized, the electromagnetic coil generates a magnetic field which applies a driving force on the magnetic particle sufficient to overcome adhesive forces exhibited between the probe tip and specimen. The atomic force microscope includes two independently displaceable piezo elements operable along a Z-axis. A controller drives the first Z-axis piezo element to provide a controlled approach between the probe tip and specimen up to a point of contact between the probe tip and specimen. The controller then drives the first Z-axis piezo element to withdraw the cantilever from the specimen. The controller also activates the pulse release system which drives the probe tip away from the specimen during withdrawal. Following withdrawal, the controller adjusts the height of the second Z-axis piezo element to maintain a substantially constant approach distance between successive samples.

Biological processes, quantum mechanics and electromagnetic fields: the possibility of device-encapsulated human intention in medical therapies.

PubMed

Kohane, M J; Tiller, W A

2001-06-01

The general hypothesis that quantum mechanics (QM) and thermodynamic concepts relate to biological systems is discussed and applied to the biological influence of: (1) electromagnetic fields (EMFs); and (2) EMFs that have been exposed to human intention. We illustrate our hypothesis with experiments involving four simultaneous treatments: exposure to ambient EMFs in the laboratory environment (C), exposure in a Faraday cage (F) and exposure in a Faraday cage with either: (i) an electronic device (IIED) which had been exposed to a specific human intention (d,j); or (ii) a non-exposed, physically identical, device (d,o). Experimental systems were fitness and energy metabolism in Drosophila melanogaster, in vitro enzyme activity and molecular concentration variability over time. Results indicated that shielding from ambient EMFs via a Faraday cage (F) made a significant difference relative to the unshielded control (C). Further, (d,o) had a significant lowering effect in the shielded environment. Finally, there was a strong 'intention' effect with the IIED (d,j) producing significant and positive effects in comparison to (d,o) in each experimental system. Copyright 2001 Harcourt Publishers Ltd.

Natural time analysis of critical phenomena: the case of pre-fracture electromagnetic emissions.

PubMed

Potirakis, S M; Karadimitrakis, A; Eftaxias, K

2013-06-01

Criticality of complex systems reveals itself in various ways. One way to monitor a system at critical state is to analyze its observable manifestations using the recently introduced method of natural time. Pre-fracture electromagnetic (EM) emissions, in agreement to laboratory experiments, have been consistently detected in the MHz band prior to significant earthquakes. It has been proposed that these emissions stem from the fracture of the heterogeneous materials surrounding the strong entities (asperities) distributed along the fault, preventing the relative slipping. It has also been proposed that the fracture of heterogeneous material could be described in analogy to the critical phase transitions in statistical physics. In this work, the natural time analysis is for the first time applied to the pre-fracture MHz EM signals revealing their critical nature. Seismicity and pre-fracture EM emissions should be two sides of the same coin concerning the earthquake generation process. Therefore, we also examine the corresponding foreshock seismic activity, as another manifestation of the same complex system at critical state. We conclude that the foreshock seismicity data present criticality features as well.

Damage assessment of long-range rocket system by electromagnetic pulse weapon

NASA Astrophysics Data System (ADS)

Cao, Lingyu; Liu, Guoqing; Li, Jinming

2017-08-01

This paper analyzes the damage mechanism and characteristics of electromagnetic pulse weapon, establishes the index system of survivability of long-range rocket launcher system, and uses AHP method to establish the combat effectiveness model of long-range rocket missile system. According to the damage mechanism and characteristics of electromagnetic pulse weapon, the damage effect of the remote rocket system is established by using the exponential method to realize the damage efficiency of the remote rocket system.

76 FR 72686 - 36(b)(1) Arms Sales Notification

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-25

... Electromagnetic Aircraft Launch System/Advanced Arresting Gear (EMALS/AAG). The EMALS long lead sub-assemblies... United Kingdom--Electromagnetic Aircraft Launch System Long Lead Sub- Assemblies The Government of the United Kingdom (UK) has requested the long lead sub-assemblies for the Electromagnetic Aircraft Launch...

The Effects of Electromagnetic Fields on The Nervous System,

DTIC Science & Technology

Superior Cervical Ganglia: Design of Waveguide Apparatus, and Calculation of Specific Absorption Rate; Effects of Electromagnetic Fields on Muscle ... Contraction ; Effects of Electromagnetic Fields on Auditory System: Effect of Noise Masking on Threshold of Evoked Auditory Responses, Microwave-induced Cochlear Microphonics in Guinea Pigs.

Relativistic theory for picosecond time transfer in the vicinity of Earth

NASA Technical Reports Server (NTRS)

Petit, G.; Wolf, P.

1994-01-01

The problem of light propagation is treated in a geocentric reference system with the goal of ensuring picosecond accuracy for time transfer techniques using electromagnetic signals in the vicinity of the Earth. We give an explicit formula for a one way time transfer, to be applied when the spatial coordinates of the time transfer stations are known in a geocentric reference system rotating with the Earth. This expression is extended, at the same accuracy level of one picosecond, to the special cases of two way and LASSO time transfers via geostationary satellites.

Electromagnetic Radiation Hazards Testing for Non-Ionizing Radio Frequency Transmitting Equipment

DTIC Science & Technology

2012-12-19

Hazards of Electromagnetic Radiation to Ordnance (HERO), Personnel (HERP), and Fuel (HERF) protection guidance for intentional non-ionizing Radio...HERO Hazards of Electromagnetic Radiation to Ordnance HERP Hazards of Electromagnetic Radiation to Personnel IEEE Institute of Electrical and...Systems Command Technical Manual, Electromagnetic Radiation Hazards ( Hazards to Ordnance ), 1 July 2008.

Reflector for efficient coupling of a laser beam to air or other fluids

DOEpatents

Kare, Jordin T.

1992-01-01

A reflector array is disclosed herein that provides a controlled region or regions of plasma breakdowns from a laser beam produced at a remotely-based laser source. The plasma may be applied to produce thrust to propel a spacecraft, or to diagnose a laser beam, or to produce shockwaves. The spacecraft propulsion system comprises a reflector array attached to the vehicle. The reflector array comprises a plurality of reflectors spaced apart on a reflective surface, with each reflector acting as an independent focusing mirror. The reflectors are spaced closely together to form a continuous or partially-continuous surface. The reflector array may be formed from a sheet of reflective material, such as copper or aluminum. In operation, a beam of electromagnetic energy, such as a laser beam, is directed at the reflectors which focus the reflected electromagnetic energy at a plurality of regions off the surface. The energy concentrated in the focal region causes a breakdown of the air or other fluid in the focal region, creating a plasma. Electromagnetic energy is absorbed in the plasma and it grows in volume, compressing and heating the adjacent fluid thereby providing thrust. Laser pulses may be applied repetitively. After each such thrust pulse, fresh air can be introduced next to the surface either laterally, or through a perforated surface. If air or some other gas or vapor is supplied, for example from a tank carried on board a vehicle, this invention may also be used to provide thrust in a vacuum environment.

Final Technical Report for "Applied Mathematics Research: Simulation Based Optimization and Application to Electromagnetic Inverse Problems"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haber, Eldad

2014-03-17

The focus of research was: Developing adaptive mesh for the solution of Maxwell's equations; Developing a parallel framework for time dependent inverse Maxwell's equations; Developing multilevel methods for optimization problems with inequality constraints; A new inversion code for inverse Maxwell's equations in the 0th frequency (DC resistivity); A new inversion code for inverse Maxwell's equations in low frequency regime. Although the research concentrated on electromagnetic forward and in- verse problems the results of the research was applied to the problem of image registration.

An electromagnetic compressive force by cell exciter stimulates chondrogenic differentiation of bone marrow-derived mesenchymal stem cells.

PubMed

Park, Sang-Hyug; Sim, Woo Young; Park, Sin Wook; Yang, Sang Sik; Choi, Byung Hyune; Park, So Ra; Park, Kwideok; Min, Byoung-Hyun

2006-11-01

In this study, we present a biological micro-electromechanical system and its application to the chondrogenic differentiation of rabbit bone marrow-derived mesenchymal stem cells (MSCs). Actuated by an electromagnetic force, the micro cell exciter was designed to deliver a cyclic compressive load (CCL) with various magnitudes. Two major parts in the system are an actuator and a cartridge-type chamber. The former has a permanent magnet and coil, and the latter is equipped with 7 sample dishes and 7 metal caps. Mixed with a 2.4% alginate solution, the alginate/MSC layers were positioned in the sample dishes; the caps contained chondrogenic defined medium without transforming growth factor-beta (TGF-beta). Once powered, the actuator coil-derived electromagnetic force pulled the metal caps down, compressing the samples. The cyclic load was given at 1-Hz frequency for 10 min twice a day. Samples in the dishes without a cap served as a control. The samples were analyzed at 3, 5, and 7 days after stimulation for cell viability, biochemical assays, histologic features, immunohistochemistry, and gene expression of the chondrogenic markers. Applied to the alginate/MSC layer, the CCL system enhanced the synthesis of cartilage-specific matrix proteins and the chondrogenic markers, such as aggrecan, type II collagen, and Sox9. We found that the micromechanically exerted CCL by the cell exciter was very effective in enhancing the chondrogenic differentiation of MSCs, even without using exogenous TGF-beta.

Soft magnetic tweezers: a proof of principle.

PubMed

Mosconi, Francesco; Allemand, Jean François; Croquette, Vincent

2011-03-01

We present here the principle of soft magnetic tweezers which improve the traditional magnetic tweezers allowing the simultaneous application and measurement of an arbitrary torque to a deoxyribonucleic acid (DNA) molecule. They take advantage of a nonlinear coupling regime that appears when a fast rotating magnetic field is applied to a superparamagnetic bead immersed in a viscous fluid. In this work, we present the development of the technique and we compare it with other techniques capable of measuring the torque applied to the DNA molecule. In this proof of principle, we use standard electromagnets to achieve our experiments. Despite technical difficulties related to the present implementation of these electromagnets, the agreement of measurements with previous experiments is remarkable. Finally, we propose a simple way to modify the experimental design of electromagnets that should bring the performances of the device to a competitive level.

The invariance of classical electromagnetism under Charge-conjugation, Parity and Time-reversal (CPT) transformations

NASA Technical Reports Server (NTRS)

Norbury, John W.

1989-01-01

The invariance of classical electromagnetism under charge-conjugation, parity, and time-reversal (CPT) is studied by considering the motion of a charged particle in electric and magnetic fields. Upon applying CPT transformations to various physical quantities and noting that the motion still behaves physically demonstrates invariance.

Hybrid Contactless Heating and Levitation

NASA Technical Reports Server (NTRS)

Lee, M. C.

1985-01-01

Acoustic and electromagnetic fields applied. In contactless processing apparatus, acoustic and electromagnetic levitating fields employed alternately or simultaneously with amplitude of each controlled to produce various combinations of heating, cooling, and levitation. Apparatus provides rapid heating and cooling or slow heating and cooling for such processes as nucleation, crystallization, incubation, deep undercooling, and heterogeneity control.

International Symposium on Electromagnetic Compatibility, 25th, Arlington, VA, August 23-25, 1983, Symposium Record

NASA Astrophysics Data System (ADS)

Subjects related to electromagnetic compatibility (EMC) analysis are discussed, taking into account forcing terms of line equations for externally excited transmission lines, E-fields over ground, electromagnetic near fields as a function of electrical size, a program for experimental verification of EMC analysis models, random susceptability of an IC 7400 TTL NAND gate, and a comparison of IEMCAP and SEMCAP. Other topics explored are concerned with EMC measurements, spectrum management, the electromagnetic pulse (EMP), a Navy EMC program, measurement systems, filters, EMC design, electromagnetic vulnerability (EMV) assessment of weapon systems, FCC rules and regulations, shielding, and electromagnetic interference (EMI) in communication systems. Attention is also given to nonsinusoidal functions in radar and communications, transients/electrostatic discharge, open field testing, cables and connectors, interference effects of induced and conducted earth current at dc and ELF, test cells, and cable coupling.

Basic and Applied Research in the Field of Electronics and Communications

DTIC Science & Technology

1998-02-18

Epitaxy on Semiconductor Surfaces Song, S. Ph.D., 1996 Optical Frequency Metrology Lutwak , R. Ph.D., 1996 Precision Physical Measurements...Systems." J. Opt. Soc. Am. 514(8): 2167-2173 (1997). Lutwak , R., J. Holley, P.P. Chang, S. Paine, D. Kleppner, and T. Ducas. "Circular States of...Domain Analysis of Electromagnetic Interference and Radiation Problems. Ph.D. diss., Dept. of Electr. Eng. and Comput. Sei., MIT, 1995. Lutwak , R

Broadening and Simplifying the First SETI Protocol

NASA Astrophysics Data System (ADS)

Michaud, M. A. G.

The Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence, known informally as the First SETI Protocol, is the primary existing international guidance on this subject. During the fifteen years since the document was issued, several people have suggested revisions or additional protocols. This article proposes a broadened and simplified text that would apply to the detection of alien technology in our solar system as well as to electromagnetic signals from more remote sources.

Extremely Low Frequency (ELF) Communications Program: Non-Ionizing Electromagnetic Radiation Literature Evaluation and Assessment, 1986-1987 Literature Review.

DTIC Science & Technology

1987-11-01

and Carsteen E L (1985). Growth Rate and Mitotic Index Analysis of Vicia Faba L. Roots Exposed to 60-Hz Electric Fields. Bioelectromagnetics, Vol. 6...the observed effects. The mitotic index was also influenced. 5) In monkeys, central nervous system excitability was influenced by applying fields...Literature Search and Retrieval ...................... 16 2.2 Literature Culling and Indexing ...................... 18 2.3 Foreign Literature

Electromagnetic tracking system with reduced distortion using quadratic excitation.

PubMed

Bien, Tomasz; Li, Mengfei; Salah, Zein; Rose, Georg

2014-03-01

Electromagnetic tracking systems, frequently used in minimally invasive surgery, are affected by conductive distorters. The influence of conductive distorters on electromagnetic tracking system accuracy can be reduced through magnetic field modifications. This approach was developed and tested. The voltage induced directly by the emitting coil in the sensing coil without additional influence by the conductive distorter depends on the first derivative of the voltage on the emitting coil. The voltage which is induced indirectly by the emitting coil across the conductive distorter in the sensing coil, however, depends on the second derivative of the voltage on the emitting coil. The electromagnetic tracking system takes advantage of this difference by supplying the emitting coil with a quadratic excitation voltage. The method is adaptive relative to the amount of distortion cause by the conductive distorters. This approach is evaluated with an experimental setup of the electromagnetic tracking system. In vitro testing showed that the maximal error decreased from 10.9 to 3.8 mm when the quadratic voltage was used to excite the emitting coil instead of the sinusoidal voltage. Furthermore, the root mean square error in the proximity of the aluminum disk used as a conductive distorter was reduced from 3.5 to 1.6 mm when the electromagnetic tracking system used the quadratic instead of sinusoidal excitation. Electromagnetic tracking with quadratic excitation is immune to the effects of a conductive distorter, especially compared with sinusoidal excitation of the emitting coil. Quadratic excitation of electromagnetic tracking for computer-assisted surgery is promising for clinical applications.

Simulation study of localization of electromagnetic waves in two-dimensional random dipolar systems.

PubMed

Wang, Ken Kang-Hsin; Ye, Zhen

2003-12-01

We study the propagation and scattering of electromagnetic waves by random arrays of dipolar cylinders in a uniform medium. A set of self-consistent equations, incorporating all orders of multiple scattering of the electromagnetic waves, is derived from first principles and then solved numerically for electromagnetic fields. For certain ranges of frequencies, spatially localized electromagnetic waves appear in such a simple but realistic disordered system. Dependence of localization on the frequency, radiation damping, and filling factor is shown. The spatial behavior of the total, coherent, and diffusive waves is explored in detail, and found to comply with a physical intuitive picture. A phase diagram characterizing localization is presented, in agreement with previous investigations on other systems.

Systems and strippable coatings for decontaminating structures that include porous material

DOEpatents

Fox, Robert V [Idaho Falls, ID; Avci, Recep [Bozeman, MT; Groenewold, Gary S [Idaho Falls, ID

2011-12-06

Methods of removing contaminant matter from porous materials include applying a polymer material to a contaminated surface, irradiating the contaminated surface to cause redistribution of contaminant matter, and removing at least a portion of the polymer material from the surface. Systems for decontaminating a contaminated structure comprising porous material include a radiation device configured to emit electromagnetic radiation toward a surface of a structure, and at least one spray device configured to apply a capture material onto the surface of the structure. Polymer materials that can be used in such methods and systems include polyphosphazine-based polymer materials having polyphosphazine backbone segments and side chain groups that include selected functional groups. The selected functional groups may include iminos, oximes, carboxylates, sulfonates, .beta.-diketones, phosphine sulfides, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, monothio phosphinic acids, and dithio phosphinic acids.

Electromagnetic Safety of Spacecraft During Active Experiments with the Use of Plasma Accelerators and Ion Injectors

NASA Astrophysics Data System (ADS)

Plokhikh, Andrey; Popov, Garri; Shishkin, Gennady; Antropov, Nikolay; Vazhenin, Nikolay; Soganova, Galina

Works under the development and application of stationary and pulsed plasma accelerators of charged particles conducted at the Moscow Aviation Institute and Research Institute of Applied Mechanics and Electrodynamics during over 40 years, active experiments on board meteorological rockets, artificial Earth satellites and "Mir" orbital station including [1], allowed to obtain data on the influence of pulsed and continuous plasma injection with the given parameters on the drop of energetic particles out of the radiation belts, efficiency of artificial excitation and propagation of electromagnetic waves in ELF and VLF ranges, and evolution of artificial plasma formations in different regions of ionosphere. Variation of the near-spacecraft electromagnetic environment related to the operation of plasma injectors was registered during active experiments along with the global electrodynamic processes. The measured electromagnetic fields are of rather high intensity and occupy frequency spectrum from some Hz to tens of GHz that may be of definite danger for the operation of spacecraft and its onboard systems. Analysis for the known test data is presented in the paper and methods are discussed for the diagnostics and modeling under laboratory conditions of radiative processes proceeding at the operation of plasma accelerators and ion injectors used while making active space experiments. Great attention is paid to the methodological and metrological bases for making radio measurements in vacuum chambers, design concept and hardware configuration of ground special-purpose instrumentation scientific complexes [2]. Basic requirements are formulated for the measurements and analysis of electromagnetic fields originating during the operation of plasma accelerators, including the radiative induced and conductive components inside the spacecraft, as well as the wave emission and excitation outside the spacecraft, in the ionosphere including. Measurement results for the intrinsic electromagnetic emission of stationary and pulsed plasma injectors and of the electric propulsions developed on their basis are discussed. Predictive estimates are presented for the influence of originating electromagnetic fields and emissions on the electromagnetic safety of spacecraft and its systems and for the reliability of communication with ground command and tracking stations, and recommendations are given on the reduction of destructive effects. 1. S. Avdyushin, I. Podgorny, G. Popov, A. Porotnikov, "Plasma Accelerator Use for Studying Physical Processes in Space." Plasma Accelerators and Ion Injectors, Nauka, 1984. 2. A. Plokhikh, "Peculiarities of Radio Measurements in the Metal Vacuum Chambers." Vestnik moskovskogo aviatsionnogo instituta. v. 11, No. 2, 2004, pp. 66-78.

Electromagnetic fields in medicine - The state of art.

PubMed

Pasek, Jarosław; Pasek, Tomasz; Sieroń-Stołtny, Karolina; Cieślar, Grzegorz; Sieroń, Aleksander

2016-01-01

Intense development of methods belonging to physical medicine has been noted recently. There are treatment methods, which in many cases lead to reduction treatment time and positively influence on quality of life treatment patients. The present physical medicine systematically extends their therapeutic possibilities. This above applies to illnesses and injuries of locomotor system, diseases affecting of soft tissues, as well as chronic wounds. The evidence on this are the results of basic and clinical examinations relating the practical use of electromagnetic fields in medicine. In this work the authors introduced the procedure using the current knowledge relating to physical characteristic and biological effects of the magnetic fields. In the work the following methods were used: static magnetic fields, spatial magnetic fields, the variable magnetic fields both with laser therapy (magnetolaserotherapy) and variable magnetic fields both with light optical non-laser (magnetoledtherapy) talked.

Semiconductor crystal growth in crossed electric and magnetic fields: Center Director's Discretionary Fund

NASA Technical Reports Server (NTRS)

Mazuruk, K.; Volz, M. P.

1996-01-01

A unique growth cell was designed in which crossed electric and magnetic fields could be separately or simultaneously applied during semiconductor crystal growth. A thermocouple was inserted into an InSb melt inside the growth cell to examine the temperature response of the fluid to applied electromagnetic fields. A static magnetic field suppressed time-dependent convection when a destabilizing thermal field was applied. The simultaneous application of electric and magnetic fields resulted in forced convection in the melt. The InSb ingots grown in the cell were polycrystalline. An InGaSb crystal, 0.5 cm in diameter and 23-cm long, was grown without electromagnetic fields applied. The axial composition results indicated that complete mixing in the melt occurred for this large aspect ratio.

The distinguishing effects of low-intensity electromagnetic radiation of different extremely high frequencies on Enterococcus hirae: growth rate inhibition and scanning electron microscopy analysis.

PubMed

Hovnanyan, K; Kalantaryan, V; Trchounian, A

2017-09-01

A low-intensity electromagnetic field of extremely high frequency has inhibitory and stimulatory effects on bacteria, including Enterococcus hirae. It was shown that the low-intensity (the incident power density of 0·06 mW cm -2 ) electromagnetic field at the frequencies of 51·8 GHz and 53 GHz inhibited E. hirae ATCC 9790 bacterial growth rate; a stronger effect was observed with 53 GHz, regardless of exposure duration (0·5 h, 1 h or 2 h). Scanning electron microscopy analysis of these effects has been done; the cells were of spherical shape. Electromagnetic field at 53 GHz, but not 51·8 GHz, changed the cell size-the diameter was enlarged 1·3 fold at 53 GHz. These results suggest the difference in mechanisms of action on bacteria for electromagnetic fields at 51·8 GHz and 53 GHz. A stronger inhibitory effect of low-intensity electromagnetic field on Enterococcus hirae ATCC 9790 bacterial growth rate was observed with 53 GHz vs 51·8 GHz, regardless of exposure duration. Scanning electron microscopy analysis showed that almost all irradiated cells in the population have spherical shapes similar to nonirradiated ones, but they have increased diameters in case of irradiated cells at 53 GHz, but not 51·8 GHz. The results are novel, showing distinguishing effects of low-intensity electromagnetic field of different frequencies. They could be applied in treatment of food and different products in medicine and veterinary, where E. hirae plays an important role. © 2017 The Society for Applied Microbiology.

Generating a heated fluid using an electromagnetic radiation-absorbing complex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

A vessel including a concentrator configured to concentrate electromagnetic (EM) radiation received from an EM radiation source and a complex configured to absorb EM radiation to generate heat. The vessel is configured to receive a cool fluid from the cool fluid source, concentrate the EM radiation using the concentrator, apply the EM radiation to the complex, and transform, using the heat generated by the complex, the cool fluid to the heated fluid. The complex is at least one of consisting of copper nanoparticles, copper oxide nanoparticles, nanoshells, nanorods, carbon moieties, encapsulated nanoshells, encapsulated nanoparticles, and branched nanostructures. Further, the EMmore » radiation is at least one of EM radiation in an ultraviolet region of an electromagnetic spectrum, in a visible region of the electromagnetic spectrum, and in an infrared region of the electromagnetic spectrum.« less

Effect of radio frequency waves of electromagnetic field on the tubulin.

PubMed

Taghi, Mousavi; Gholamhosein, Riazi; Saeed, Rezayi-Zarchi

2013-09-01

Microtubules (MTs) are macromolecular structures consisting of tubulin heterodimers and present in almost every eukaryotic cell. MTs fulfill all conditions for generation of electromagnetic field and are electrically polar due to the electrical polarity of a tubulin heterodimer. The calculated static electric dipole moment of about 1000 Debye makes them capable of being aligned parallel to the applied electromagnetic field direction. In the present study, the tubulin heterodimers were extracted and purified from the rat brains. MTs were obtained by polymerization in vitro. Samples of microtubules were adsorbed in the absence and in the presence of electromagnetic fields with radio frequency of 900 Hz. Our results demonstrate the effect of electromagnetic field with 900 Hz frequency to change the structure of MTs. In this paper, a related patent was used that will help to better understand the studied subject.

Immunity of medical electrical equipment to radiated RF disturbances

NASA Astrophysics Data System (ADS)

Mocha, Jan; Wójcik, Dariusz; Surma, Maciej

2018-04-01

Immunity of medical equipment to radiated radio frequency (RF) electromagnetic (EM) fields is a priority issue owing to the functions that the equipment is intended to perform. This is reflected in increasingly stringent normative requirements that medical electrical equipment has to conform to. A new version of the standard concerning electromagnetic compatibility of medical electrical equipment IEC 60601-1-2:2014 has recently been published. The paper discusses major changes introduced in this edition of the standard. The changes comprise more rigorous immunity requirements for medical equipment as regards radiated RF EM fields and a new requirement for testing the immunity of medical electrical equipment to disturbances coming from digital radio communication systems. Further on, the paper presents two typical designs of the input block: involving a multi-level filtering and amplification circuit and including a solution which integrates an input amplifier and an analog-to-digital converter in one circuit. Regardless of the applied solution, presence of electromagnetic disturbances in the input block leads to demodulation of the disturbance signal envelope. The article elaborates on mechanisms of amplitude detection occurring in such cases. Electromagnetic interferences penetration from the amplifier's input to the output is also described in the paper. If the aforementioned phenomena are taken into account, engineers will be able to develop a more conscious approach towards the issue of immunity to RF EM fields in the process of designing input circuits in medical electrical equipment.

Entanglement control in a superconducting qubit system by an electromagnetic field

NASA Astrophysics Data System (ADS)

Zhang, Y. Q.; Xu, J. B.

2011-08-01

By making use of the dynamical algebraic method we investigate a quantum system consisting of superconducting qubits interacting with data buses, where the qubits are driven by time-dependent electromagnetic field and obtain an explicit expression of time evolution operator. Furthermore, we explore the entanglement dynamics and the influence of the time-dependent electromagnetic field and the initial state on the entanglement sudden death and birth for the system. It is shown that the entanglement between the qubit and bus as well as the entanglement sudden death and birth can be controlled by the time-dependent electromagnetic field.

Statistical EMC: A new dimension electromagnetic compatibility of digital electronic systems

NASA Astrophysics Data System (ADS)

Tsaliovich, Anatoly

Electromagnetic compatibility compliance test results are used as a database for addressing three classes of electromagnetic-compatibility (EMC) related problems: statistical EMC profiles of digital electronic systems, the effect of equipment-under-test (EUT) parameters on the electromagnetic emission characteristics, and EMC measurement specifics. Open area test site (OATS) and absorber line shielded room (AR) results are compared for equipment-under-test highest radiated emissions. The suggested statistical evaluation methodology can be utilized to correlate the results of different EMC test techniques, characterize the EMC performance of electronic systems and components, and develop recommendations for electronic product optimal EMC design.

Electromagnetic emission experiences using electric propulsion systems: A survey

NASA Technical Reports Server (NTRS)

Sovey, James S.; Zana, Lynnette M.; Knowles, Steven C.

1987-01-01

As electric propulsion systems become ready to integrate with spacecraft systems, the impact of propulsion system radiated emissions are of significant interest. Radiated emissions from electromagnetic, electrostatic, and electrothermal systems have been characterized and results synopsized from the literature describing 21 space flight programs. Electromagnetic radiated emission results from ground tests and flight experiences are presented with particular attention paid to the performance of spacecraft subsystems and payloads during thruster operations. The impacts to transmission of radio frequency signals through plasma plumes are also reviewed.

The accuracy of an electromagnetic navigation system in lateral skull base approaches.

PubMed

Komune, Noritaka; Matsushima, Ken; Matsuo, Satoshi; Safavi-Abbasi, Sam; Matsumoto, Nozomu; Rhoton, Albert L

2017-02-01

Image-guided optical tracking systems are being used with increased frequency in lateral skull base surgery. Recently, electromagnetic tracking systems have become available for use in this region. However, the clinical accuracy of the electromagnetic tracking system has not been examined in lateral skull base surgery. This study evaluates the accuracy of electromagnetic navigation in lateral skull base surgery. Cadaveric and radiographic study. Twenty cadaveric temporal bones were dissected in a surgical setting under a commercially available, electromagnetic surgical navigation system. The target registration error (TRE) was measured at 28 surgical landmarks during and after performing the standard translabyrinthine and middle cranial fossa surgical approaches to the internal acoustic canal. In addition, three demonstrative procedures that necessitate navigation with high accuracy were performed; that is, canalostomy of the superior semicircular canal from the middle cranial fossa, 1 cochleostomy from the middle cranial fossa, 2 and infralabyrinthine approach to the petrous apex. 3 RESULTS: Eleven of 17 (65%) of the targets in the translabyrinthine approach and five of 11 (45%) of the targets in the middle fossa approach could be identified in the navigation system with TRE of less than 0.5 mm. Three accuracy-dependent procedures were completed without anatomical injury of important anatomical structures. The electromagnetic navigation system had sufficient accuracy to be used in the surgical setting. It was possible to perform complex procedures in the lateral skull base under the guidance of the electromagnetically tracked navigation system. N/A. Laryngoscope, 2016 127:450-459, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Numerical Technology for Large-Scale Computational Electromagnetics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharpe, R; Champagne, N; White, D

The key bottleneck of implicit computational electromagnetics tools for large complex geometries is the solution of the resulting linear system of equations. The goal of this effort was to research and develop critical numerical technology that alleviates this bottleneck for large-scale computational electromagnetics (CEM). The mathematical operators and numerical formulations used in this arena of CEM yield linear equations that are complex valued, unstructured, and indefinite. Also, simultaneously applying multiple mathematical modeling formulations to different portions of a complex problem (hybrid formulations) results in a mixed structure linear system, further increasing the computational difficulty. Typically, these hybrid linear systems aremore » solved using a direct solution method, which was acceptable for Cray-class machines but does not scale adequately for ASCI-class machines. Additionally, LLNL's previously existing linear solvers were not well suited for the linear systems that are created by hybrid implicit CEM codes. Hence, a new approach was required to make effective use of ASCI-class computing platforms and to enable the next generation design capabilities. Multiple approaches were investigated, including the latest sparse-direct methods developed by our ASCI collaborators. In addition, approaches that combine domain decomposition (or matrix partitioning) with general-purpose iterative methods and special purpose pre-conditioners were investigated. Special-purpose pre-conditioners that take advantage of the structure of the matrix were adapted and developed based on intimate knowledge of the matrix properties. Finally, new operator formulations were developed that radically improve the conditioning of the resulting linear systems thus greatly reducing solution time. The goal was to enable the solution of CEM problems that are 10 to 100 times larger than our previous capability.« less

Plasmons and Polaritons in Low Dimensional Systems

NASA Astrophysics Data System (ADS)

Sun, Zhiyuan

Nearly everything relies on the electromagnetic (EM) force to be in its current form. Therefore, light-matter interaction is both a fundamental and a practical subject in physics. Focusing on the electromagnetic field, the matter degrees of freedom can be encoded into its response to the EM field in the form of charge density and urrent. Reshaped by the EM response, the photons in condensed matter systems appear as various collective modes. In this doctoral dissertation, I present our investigation of the linear and nonlinear EM response theory especially in the hydrodynamic regime of electron systems. Electrons in pristine solids behave as a hydrodynamic fluid in a certain range of temperatures and frequencies. We show that the response of such a fluid to electromagnetic field is different from what is predicted by the usual kinetic theory. Certain aspects of this response are universal, for example, a direct relation between the linear and second-order nonlinear optical conductivities. Discovery of this relation enriches our understanding of the light-matter interaction in diverse electron systems and new materials such as graphene. Subsequently, I study the properties of the charged collective modes, the plasmons and demons in 2D Dirac fluids, e.g., the electron-hole system in graphene. Under non-equilibrium situation, the amplitudes of these collective modes could possibly grow due to an effect of adiabatic amplification. I also present our study of the hyperbolic polaritons, the EM modes in hyperbolic materials. When confined in cavities, they develop isolated eigen modes which could be efficiently predicted by applying semi-classical quantization rules to fictitious particles. We demonstrate this Hamiltonian Optics analytically for cavities of spheroidal shapes, and predict novel geometric patterns of the electric field distribution due to classical periodic orbits.

Real-time closed-loop simulation and upset evaluation of control systems in harsh electromagnetic environments

NASA Technical Reports Server (NTRS)

Belcastro, Celeste M.

1989-01-01

Digital control systems for applications such as aircraft avionics and multibody systems must maintain adequate control integrity in adverse as well as nominal operating conditions. For example, control systems for advanced aircraft, and especially those with relaxed static stability, will be critical to flight and will, therefore, have very high reliability specifications which must be met regardless of operating conditions. In addition, multibody systems such as robotic manipulators performing critical functions must have control systems capable of robust performance in any operating environment in order to complete the assigned task reliably. Severe operating conditions for electronic control systems can result from electromagnetic disturbances caused by lightning, high energy radio frequency (HERF) transmitters, and nuclear electromagnetic pulses (NEMP). For this reason, techniques must be developed to evaluate the integrity of the control system in adverse operating environments. The most difficult and illusive perturbations to computer-based control systems that can be caused by an electromagnetic environment (EME) are functional error modes that involve no component damage. These error modes are collectively known as upset, can occur simultaneously in all of the channels of a redundant control system, and are software dependent. Upset studies performed to date have not addressed the assessment of fault tolerant systems and do not involve the evaluation of a control system operating in a closed-loop with the plant. A methodology for performing a real-time simulation of the closed-loop dynamics of a fault tolerant control system with a simulated plant operating in an electromagnetically harsh environment is presented. In particular, considerations for performing upset tests on the controller are discussed. Some of these considerations are the generation and coupling of analog signals representative of electromagnetic disturbances to a control system under test, analog data acquisition, and digital data acquisition from fault tolerant systems. In addition, a case study of an upset test methodology for a fault tolerant electromagnetic aircraft engine control system is presented.

Aircraft Electromagnetic Compatibility.

DTIC Science & Technology

1987-06-01

Human Exposure to Radio Frequency Electromagnetic Fields , 300 KiloHertz to 100 GigaHertz." 6. ARINC 429-8, "Digital Information Transfer System (DITS...142 V EXECUTIVE SUMMARY The Aircraft Electromagnetic Compatibility guidelines document deals with electromagnetic compatibility in a... electromagnetic interference paths (figure EI. TYPE PATH 400 Hz Electrostatic MagneticCharge Electric Field Transients 5 R d t Coupling 150/i 300o Wire

The stress system generated by an electromagnetic field in a suspension of drops

NASA Technical Reports Server (NTRS)

Erdogan, M. E.

1982-01-01

The stress generated in a suspension of drops in the presence of a uniform electric field and a pure straining motion, taking into account that the magnetohydrodynamic effects are dominant was calculated. It was found that the stress generated in the suspension depended on the direction of the applied electric field, the dielectric constants, the vicosity coefficients, the conductivities, and the permeabilities of fluids inside and outside the drops. The expression of the particle stress shows that for fluids which are good conductors and poor dielectrics, especially for larger drops, magnetohydrodynamic effects end to reduce the dependence on the direction of the applied electric field.

Voltage-Induced Nonlinear Conduction Properties of Epoxy Resin/Micron-Silver Particles Composites

NASA Astrophysics Data System (ADS)

Qu, Zhaoming; Lu, Pin; Yuan, Yang; Wang, Qingguo

2018-01-01

The nonlinear conduction properties of epoxy resin (ER)/micron-silver particles (MP) composites were investigated. Under sufficient high intensity applied constant voltage, the obvious nonlinear conduction properties of the samples with volume fraction 25% were found. With increments in the voltage, the conductive switching effect was observed. The nonlinear conduction mechanism of the ER/MP composites under high applied voltages could be attributed to the electrical current conducted via discrete paths of conductive particles induced by the electric field. The test results show that the ER/MP composites with nonlinear conduction properties are of great potential application in electromagnetic protection of electron devices and systems.

Gauge-invariant expectation values of the energy of a molecule in an electromagnetic field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mandal, Anirban; Hunt, Katharine L. C.

In this paper, we show that the full Hamiltonian for a molecule in an electromagnetic field can be separated into a molecular Hamiltonian and a field Hamiltonian, both with gauge-invariant expectation values. The expectation value of the molecular Hamiltonian gives physically meaningful results for the energy of a molecule in a time-dependent applied field. In contrast, the usual partitioning of the full Hamiltonian into molecular and field terms introduces an arbitrary gauge-dependent potential into the molecular Hamiltonian and leaves a gauge-dependent form of the Hamiltonian for the field. With the usual partitioning of the Hamiltonian, this same problem of gaugemore » dependence arises even in the absence of an applied field, as we show explicitly by considering a gauge transformation from zero applied field and zero external potentials to zero applied field, but non-zero external vector and scalar potentials. We resolve this problem and also remove the gauge dependence from the Hamiltonian for a molecule in a non-zero applied field and from the field Hamiltonian, by repartitioning the full Hamiltonian. It is possible to remove the gauge dependence because the interaction of the molecular charges with the gauge potential cancels identically with a gauge-dependent term in the usual form of the field Hamiltonian. We treat the electromagnetic field classically and treat the molecule quantum mechanically, but nonrelativistically. Our derivation starts from the Lagrangian for a set of charged particles and an electromagnetic field, with the particle coordinates, the vector potential, the scalar potential, and their time derivatives treated as the variables in the Lagrangian. We construct the full Hamiltonian using a Lagrange multiplier method originally suggested by Dirac, partition this Hamiltonian into a molecular term H{sub m} and a field term H{sub f}, and show that both H{sub m} and H{sub f} have gauge-independent expectation values. Any gauge may be chosen for the calculations; but following our partitioning, the expectation values of the molecular Hamiltonian are identical to those obtained directly in the Coulomb gauge. As a corollary of this result, the power absorbed by a molecule from a time-dependent, applied electromagnetic field is equal to the time derivative of the non-adiabatic term in the molecular energy, in any gauge.« less

The detection of brain ischaemia in rats by inductive phase shift spectroscopy.

PubMed

González, C A; Villanueva, C; Vera, C; Flores, O; Reyes, R D; Rubinsky, B

2009-08-01

Ischaemia in the brain is an important clinical problem that is often monitored and studied with expensive devices such as MRI and PET, which are not readily available in low economical resource parts of the world. We have developed a new less expensive tool for non-invasive monitoring of ischaemia in the brain. This is a first feasibility study describing the concept. The system is based on the hypothesis that electromagnetic properties of the tissue change during ischaemia and that measuring the electromagnetic properties of the bulk of the brain with non-contact means can detect these changes. The apparatus we have built and whose design we describe here consists of two electromagnetic coils placed around the head. The system measures the bulk change in time of the phase difference between the electromagnetic signal on the two coils in a range of frequencies. A mathematical model simulating the device and the measurement is also introduced. Ischaemia was induced in the brain of rats by occlusion of the right cerebral and carotid arteries. Experimental subjects were monitored for 24 h. Inductive phase shift measurements were made at five frequencies in the range of 0.1-50 MHz eight times during the observation period. An ex vivo estimation of the percentage of necrosis in the ischemic subjects at t = 24 h was done. The mathematical model was also applied to the experimental tested situation. The results of both experiments and theory show significant phase shifts increase as a function of frequency and ischaemia time. The theoretical and experimental results suggest that the tested technique has the potential to detect the processes and level of ischaemia in the brain by non-invasive, continuous, bulk volumetric monitoring with a simple and inexpensive apparatus.

Narrow field electromagnetic sensor system and method

DOEpatents

McEwan, Thomas E.

1996-01-01

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

Discriminating electromagnetic radiation based on angle of incidence

DOEpatents

Hamam, Rafif E.; Bermel, Peter; Celanovic, Ivan; Soljacic, Marin; Yeng, Adrian Y. X.; Ghebrebrhan, Michael; Joannopoulos, John D.

2015-06-16

The present invention provides systems, articles, and methods for discriminating electromagnetic radiation based upon the angle of incidence of the electromagnetic radiation. In some cases, the materials and systems described herein can be capable of inhibiting reflection of electromagnetic radiation (e.g., the materials and systems can be capable of transmitting and/or absorbing electromagnetic radiation) within a given range of angles of incidence at a first incident surface, while substantially reflecting electromagnetic radiation outside the range of angles of incidence at a second incident surface (which can be the same as or different from the first incident surface). A photonic material comprising a plurality of periodically occurring separate domains can be used, in some cases, to selectively transmit and/or selectively absorb one portion of incoming electromagnetic radiation while reflecting another portion of incoming electromagnetic radiation, based upon the angle of incidence. In some embodiments, one domain of the photonic material can include an isotropic dielectric function, while another domain of the photonic material can include an anisotropic dielectric function. In some instances, one domain of the photonic material can include an isotropic magnetic permeability, while another domain of the photonic material can include an anisotropic magnetic permeability. In some embodiments, non-photonic materials (e.g., materials with relatively large scale features) can be used to selectively absorb incoming electromagnetic radiation based on angle of incidence.

Narrow field electromagnetic sensor system and method

DOEpatents

McEwan, T.E.

1996-11-19

A narrow field electromagnetic sensor system and method of sensing a characteristic of an object provide the capability to realize a characteristic of an object such as density, thickness, or presence, for any desired coordinate position on the object. One application is imaging. The sensor can also be used as an obstruction detector or an electronic trip wire with a narrow field without the disadvantages of impaired performance when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter for transmitting a sequence of electromagnetic signals in response to a transmit timing signal, a receiver for sampling only the initial direct RF path of the electromagnetic signal while excluding all other electromagnetic signals in response to a receive timing signal, and a signal processor for processing the sampled direct RF path electromagnetic signal and providing an indication of the characteristic of an object. Usually, the electromagnetic signal is a short RF burst and the obstruction must provide a substantially complete eclipse of the direct RF path. By employing time-of-flight techniques, a timing circuit controls the receiver to sample only the initial direct RF path of the electromagnetic signal while not sampling indirect path electromagnetic signals. The sensor system also incorporates circuitry for ultra-wideband spread spectrum operation that reduces interference to and from other RF services while allowing co-location of multiple electronic sensors without the need for frequency assignments. 12 figs.

Systems, Apparatuses and Methods for Beamforming RFID Tags

NASA Technical Reports Server (NTRS)

Fink, Patrick W. (Inventor); Lin, Gregory Y. (Inventor); Ngo, Phong H. (Inventor); Kennedy, Timothy F. (Inventor)

2017-01-01

A radio frequency identification (RFID) system includes an RFID interrogator and an RFID tag having a plurality of information sources and a beamforming network. The tag receives electromagnetic radiation from the interrogator. The beamforming network directs the received electromagnetic radiation to a subset of the plurality of information sources. The RFID tag transmits a response to the received electromagnetic radiation, based on the subset of the plurality of information sources to which the received electromagnetic radiation was directed. Method and other embodiments are also disclosed.

CORRIGENDUM: A new algorithm for the shape reconstruction of perfectly conducting objects A new algorithm for the shape reconstruction of perfectly conducting objects

NASA Astrophysics Data System (ADS)

Çayören, M.; Akduman, I.; Yapar, A.; Crocco, L.

2010-03-01

The reference list should have included the conference communications [1] and [2], wherein we introduced the algorithm described in this paper. Note that a less complete description of the algorithm was given in [1]. However, the example considering a bean-shaped target is the same in the two papers and it is reused in this paper by kind permission of the Applied Computational Electromagnetics Society. References [1] Crocco L, Akduman I, Çayören M and Yapar A 2007 A new method for shape reconstruction of perfectly conducting targets The 23rd Annual Review of Progress in Applied Computational Electromagnetics (Verona, Italy) [2] Çayören M, Akduman I, Yapar A and Crocco L 2007 A new algorithm for the shape reconstruction of perfectly conducting objects Progress in Electromagnetics Research Symposium (PIERS) (Beijing, PRC)

Superconducting magnet and fabrication method

NASA Technical Reports Server (NTRS)

Israelsson, Ulf E. (Inventor); Strayer, Donald M. (Inventor)

1994-01-01

A method of trapping a field in a block of superconductor material, includes providing (i) a block of material defining a bore, (ii) a high permeability core within the bore that defines a low reluctance path through the bore, (iii) a high permeability external structure on the exterior of the block of material that defines a low reluctance path between opposite ends of the core, and (iv) an electromagnet configured to apply a magnetic field around the high permeability core. The method proceeds by energizing the electromagnet to produce an applied magnetic field around the high permeability core, cooling the block of material sufficiently to render the block of material superconducting, de-energizing the electromagnet to result in a trapped magnetic field, and at least partially removing the low reluctance path defined by the core and the external structure in order to increase the magnetic flux density of the trapped magnetic field.

Electrodynamic properties of a hypercrystal with ferrite and semiconductor layers in an external magnetic field

NASA Astrophysics Data System (ADS)

Fedorin, Illia V.

2018-01-01

Electrodynamic properties of a photonic hypercrystal formed by periodically alternating two types of anisotropic metamaterials are studied. The first metamaterial consists of ferrite and dielectric layers, while the second metamaterial consists of semiconductor and dielectric layers. The system is assumed to be placed in an external magnetic field, which applied parallel to the boundaries of the layers. An effective medium theory which is suitable for calculation of properties of long-wavelength electromagnetic modes is applied in order to derive averaged expressions for effective constitutive parameters. It has been shown that providing a conscious choice of the constitutive parameters and material fractions of magnetic, semiconductor, and dielectric layers, the system under study shows hypercrystal properties for both TE and TM waves in the different frequency ranges.

Polyphosphazine-based polymer materials

DOEpatents

Fox, Robert V.; Avci, Recep; Groenewold, Gary S.

2010-05-25

Methods of removing contaminant matter from porous materials include applying a polymer material to a contaminated surface, irradiating the contaminated surface to cause redistribution of contaminant matter, and removing at least a portion of the polymer material from the surface. Systems for decontaminating a contaminated structure comprising porous material include a radiation device configured to emit electromagnetic radiation toward a surface of a structure, and at least one spray device configured to apply a capture material onto the surface of the structure. Polymer materials that can be used in such methods and systems include polyphosphazine-based polymer materials having polyphosphazine backbone segments and side chain groups that include selected functional groups. The selected functional groups may include iminos, oximes, carboxylates, sulfonates, .beta.-diketones, phosphine sulfides, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, monothio phosphinic acids, and dithio phosphinic acids.

High-frequency magnetodielectric response in yttrium iron garnet at room temperature

NASA Astrophysics Data System (ADS)

Zhu, Jie; Liu, Yuan; Jia, Longfei; Zhang, Baoshan; Yang, Yi; Tang, Dongming

2018-05-01

Magnetic and dielectric properties of Yttrium Iron Garnet are measured over a frequency ranging from 0.5 GHz to 10 GHz with a magnetic field applied parallel to the propagation direction of the microwave. At the same time, the magnetodielectric phenomena are detected quantitatively. The maximum amplitude of the magnetodielectric coefficient is acquired at the ferromagnetic resonance frequency, and the value is up to 1.2% with the magnetic field of 1500 Oe applied. The phenomena have been explained by the Faraday's electromagnetic induction of the precession of the magnetic moments in the electromagnetic field at the ferromagnetic resonance frequency.

Reverberant Microwave Propagation

DTIC Science & Technology

2008-10-01

HERO Hazards of Electromagnetic Radiation to Ordnance HP Hewlett Packard HWD Half-Wave Dipole IEC International Electrotechnical Commission IEE...composite panels used in new ship design; Hazards of Electromagnetic Radiation to Ordnance ( HERO ) analyses; and digital wireless system performance...Electro-Explosive Device EMC Electromagnetic Compatibility ft Foot (feet) GHz Gigahertz HERO Hazards of Electromagnetic

E.M.I Effects of Cathodic Protection on Electromagnetic Flowmeters

PubMed Central

Gundogdu, Serdar; Sahin, Ozge

2007-01-01

Electromagnetic flowmeters are used to measure the speed of water flow in water distribution systems. Corrosion problem in metal pipelines can be solved by cathodic protection methods. This paper presents a research on corruptive effects of the cathodic protection system on electromagnetic flowmeter depending on its measuring principle. Experimental measurements are realized on the water distribution pipelines of the Izmir Municipality, Department of Water and Drainage Administration (IZSU) in Turkey and measurement results are given. Experimental results proved that the values measured by the electromagnetic flowmeter (EMF) are affected by cathodic protection system current. Comments on the measurement results are made and precautions to be taken are proposed.

Modeling of Stability of Electrostatic and Magnetostatic Systems

DTIC Science & Technology

2017-06-01

unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Electromagnetic systems undergo a variety of different instabilities. A broad class of those...15. SUBJECT TERMS electromagnetism , morphological instabilities, computational algorithm, gradient minimization, morphology patterns, motion by mean...Nordmark AB. Magnetic field and current are zero inside ideal conductors. Prog Electromagn Res B. 2011(27):187–212. 4. Stratton JA. Electromagnetic theory

System and Network Security Acronyms and Abbreviations

DTIC Science & Technology

2009-09-01

hazards of electromagnetic radiation to fuel HERO hazards of electromagnetic radiation to ordnance HERP hazards of electromagnetic ...ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 System and Network Security Acronyms...authentication and key management ALG application layer gateway ANSI American National Standards Institute AP access point API application

Electromagnetic image-guided orbital decompression: technique, principles, and preliminary experience with 6 consecutive cases.

PubMed

Servat, Juan J; Elia, Maxwell Dominic; Gong, Dan; Manes, R Peter; Black, Evan H; Levin, Flora

2014-12-01

To assess the feasibility of routine use of electromagnetic image guidance systems in orbital decompression. Six consecutive patients underwent stereotactic-guided three wall orbital decompression using the novel Fusion ENT Navigation System (Medtronic), a portable and expandable electromagnetic guidance system with multi-instrument tracking capabilities. The system consists of the Medtronic LandmarX System software-enabled computer station, signal generator, field-generating magnet, head-mounted marker coil, and surgical tracking instruments. In preparation for use of the LandmarX/Fusion protocol, all patients underwent preoperative non-contrast CT scan from the superior aspect of the frontal sinuses to the inferior aspect of the maxillary sinuses that includes the nasal tip. The Fusion ENT Navigation System (Medtronic™) was used in 6 patients undergoing maximal 3-wall orbital decompression for Graves' orbitopthy after a minimum of six months of disease inactivity. Preoperative Hertel exophthalmometry measured more than 27 mm in all patients. The navigation system proved to be no more difficult technically than the traditional orbital decompression approach. Electromagnetic image guidance is a stereotactic surgical navigation system that provides additional intraoperative flexibility in orbital surgery. Electromagnetic image-guidance offers the ability to perform more aggressive orbital decompressions with reduced risk.

Airborne electromagnetic bathymetry investigations in Port Lincoln, South Australia - comparison with an equivalent floating transient electromagnetic system

NASA Astrophysics Data System (ADS)

Vrbancich, Julian

2011-09-01

Helicopter time-domain airborne electromagnetic (AEM) methodology is being investigated as a reconnaissance technique for bathymetric mapping in shallow coastal waters, especially in areas affected by water turbidity where light detection and ranging (LIDAR) and hyperspectral techniques may be limited. Previous studies in Port Lincoln, South Australia, used a floating AEM time-domain system to provide an upper limit to the expected bathymetric accuracy based on current technology for AEM systems. The survey lines traced by the towed floating system were also flown with an airborne system using the same transmitter and receiver electronic instrumentation, on two separate occasions. On the second occasion, significant improvements had been made to the instrumentation to reduce the system self-response at early times. A comparison of the interpreted water depths obtained from the airborne and floating systems is presented, showing the degradation in bathymetric accuracy obtained from the airborne data. An empirical data correction method based on modelled and observed EM responses over deep seawater (i.e. a quasi half-space response) at varying survey altitudes, combined with known seawater conductivity measured during the survey, can lead to significant improvements in interpreted water depths and serves as a useful method for checking system calibration. Another empirical data correction method based on observed and modelled EM responses in shallow water was shown to lead to similar improvements in interpreted water depths; however, this procedure is notably inferior to the quasi half-space response because more parameters need to be assumed in order to compute the modelled EM response. A comparison between the results of the two airborne surveys in Port Lincoln shows that uncorrected data obtained from the second airborne survey gives good agreement with known water depths without the need to apply any empirical corrections to the data. This result significantly decreases the data-processing time thereby enabling the AEM method to serve as a rapid reconnaissance technique for bathymetric mapping.

A new topology and control method for electromagnetic transmitter power supplies

NASA Astrophysics Data System (ADS)

Zhang, Yiming; Zhang, Jialin; Yuan, Dakang

2017-04-01

As essential equipment for electromagnetic exploration, electromagnetic transmitter reverse the steady power supply with desired frequency and transmit the power through grounding electrodes. To obtain effective geophysical data during deep exploration, the transmitter needs to be high-voltage, high-current, with high-accuracy output, and yet compact and light. The researches on the power supply technologies for high-voltage high-power electromagnetic transmitter is of significant importance to the deep geophysical explorations. Therefore, the performance of electromagnetic transmitter is mainly subject to the following two aspects: the performance of emission current and voltage, and the power density. These requirements bring technical difficulties to the development of power supplies. Conventionally, high-frequency switching power supplies are applied in the design of a high-power transmitter power supply. However, the structure of the topology is complicate, which may reduce the controllability of the output voltage and the reliability of the system. Without power factor control, the power factor of the structure is relatively low. Moreover high switching frequency causes high loss. With the development of the PWM (pulse width modulation) technique, its merits of simple structure, low loss, convenient control and unit power factor have made it popular in electrical energy feedback, active filter, and power factor compensation. Studies have shown that using PWM converters and space vector modulation have become the trend in designing transmitter power supply. However, the earth load exhibits different impedances at different frequencies. Thus ensuing high-accuracy and a stable output from a transmitter power supply in harsh environment has become a key topic in the design of geophysical exploration instruments. Based on SVPWM technology, an electromagnetic transmitter power supply has been designed and its control strategy has been studied. The transmitting system is composed of power supply, SVPWM converter, and power inverter units. The functions of the units are as follows: (1) power supply: a generator providing power with three phase; (2) SVPWM converter: convert AC to DC output; (3) power inverter unit: the inverter is used to convert DC to AC output whose frequency, amplitude and waveform are variable. In the SVPWM technique, the active current and the reactive current are controlled separately, and each variable is analyzed individually, thus the power factor of the system is improved. Through controlling the PWM converter at the generation side, we can get any power factor. Usually the power factor of the generation side is set to 1. Finally, simulation and experimental results validate both the correctness of the established model and the effectiveness of the control method. We can acquire unity power factor for the input and steady current for the output. They also demonstrated that the electromagnetic transmitter power supply designed in this study can meet the practical needs of field geological exploration. We can improve the utilization of the transmitter system.

Design and simulation of printed spiral coil used in wireless power transmission systems for implant medical devices.

PubMed

Wu, Wei; Fang, Qiang

2011-01-01

Printed Spiral Coil (PSC) is a coil antenna for near-field wireless power transmission to the next generation implant medical devices. PSC for implant medical device should be power efficient and low electromagnetic radiation to human tissues. We utilized a physical model of printed spiral coil and applied our algorithm to design PSC operating at 13.56 MHz. Numerical and electromagnetic simulation of power transfer efficiency of PSC in air medium is 77.5% and 71.1%, respectively. The simulation results show that the printed spiral coil which is optimized for air will keep 15.2% power transfer efficiency in human subcutaneous tissues. In addition, the Specific Absorption Ratio (SAR) for this coil antenna in subcutaneous at 13.56 MHz is below 1.6 W/Kg, which suggests this coil is implantable safe based on IEEE C95.1 safety guideline.

Advantages and Challenges of 10-Gbps Transmission on High-Density Interconnect Boards

NASA Astrophysics Data System (ADS)

Yee, Chang Fei; Jambek, Asral Bahari; Al-Hadi, Azremi Abdullah

2016-06-01

This paper provides a brief introduction to high-density interconnect (HDI) technology and its implementation on printed circuit boards (PCBs). The advantages and challenges of implementing 10-Gbps signal transmission on high-density interconnect boards are discussed in detail. The advantages (e.g., smaller via dimension and via stub removal) and challenges (e.g., crosstalk due to smaller interpair separation) of HDI are studied by analyzing the S-parameter, time-domain reflectometry (TDR), and transmission-line eye diagrams obtained by three-dimensional electromagnetic modeling (3DEM) and two-dimensional electromagnetic modeling (2DEM) using Mentor Graphics HyperLynx and Keysight Advanced Design System (ADS) electronic computer-aided design (ECAD) software. HDI outperforms conventional PCB technology in terms of signal integrity, but proper routing topology should be applied to overcome the challenge posed by crosstalk due to the tight spacing between traces.

Prediction of the Electromagnetic Field Distribution in a Typical Aircraft Using the Statistical Energy Analysis

NASA Astrophysics Data System (ADS)

Kovalevsky, Louis; Langley, Robin S.; Caro, Stephane

2016-05-01

Due to the high cost of experimental EMI measurements significant attention has been focused on numerical simulation. Classical methods such as Method of Moment or Finite Difference Time Domain are not well suited for this type of problem, as they require a fine discretisation of space and failed to take into account uncertainties. In this paper, the authors show that the Statistical Energy Analysis is well suited for this type of application. The SEA is a statistical approach employed to solve high frequency problems of electromagnetically reverberant cavities at a reduced computational cost. The key aspects of this approach are (i) to consider an ensemble of system that share the same gross parameter, and (ii) to avoid solving Maxwell's equations inside the cavity, using the power balance principle. The output is an estimate of the field magnitude distribution in each cavity. The method is applied on a typical aircraft structure.

Effects of Electromagnetic Stimulation on Cell Density and Neural Markers in Murine Enteric Cell Cultures

NASA Astrophysics Data System (ADS)

Carreón-Rodríguez, A.; Belkind-Gerson, J.; Serrano-Luna, G.; Cañedo-Dorantes, L.

2008-08-01

Availability of adult stem cells from several organs like bone marrow, umbilical cord blood or peripheral blood has become a powerful therapeutic tool for many chronic diseases. Potential of adult stem cells for regeneration extents to other tissues among them the nervous system. However two obstacles should be resolved before such cells could be currently applied in clinical practice: a) slow growth rate and b) ability to form enough dense colonies in order to populate a specific injury or cellular deficiency. Many approaches have been explored as genetic differentiation programs, growth factors, and supplemented culture media, among others. Electromagnetic field stimulation of differentiation, proliferation, migration, and particularly on neurogenesis is little known. Since the biological effects of ELF-EMF are well documented, we hypothesize ELF-EMF could affect growth and maturation of stem cells derived of enteric tissue.

Delay-bandwidth product of electromagnetically induced transparency media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tidstroem, Jonas; Jaenes, Peter; Andersson, L. Mauritz

2007-05-15

The limitations on the delay-bandwidth product (DBP) in an electromagnetically induced transparency medium are investigated analytically by studying the susceptibility of the system, derived through Lindblad's master equation, including dephasing. The effect of inhomogeneous broadening is treated. It is shown that the DBP for a given material is fundamentally limited by the frequency-dependent absorption, while the residual absorption limits the penetration length of a pulse. Simple expression for the optimal choice of parameters to maximize the DBP are derived. Also, the length of a device is presented as a function of DBP and control-field Rabi frequency. Supporting these results, numericalmore » calculations are carried out through the Maxwell-Bloch equations in the slowly varying envelope approximation. The results are scalable, hence they apply to the case of atoms or molecules in a gas as well as quantum dots and wells.« less

Shielding Effectiveness in a Two-Dimensional Reverberation Chamber Using Finite-Element Techniques

NASA Technical Reports Server (NTRS)

Bunting, Charles F.

2006-01-01

Reverberation chambers are attaining an increased importance in determination of electromagnetic susceptibility of avionics equipment. Given the nature of the variable boundary condition, the ability of a given source to couple energy into certain modes and the passband characteristic due the chamber Q, the fields are typically characterized by statistical means. The emphasis of this work is to apply finite-element techniques at cutoff to the analysis of a two-dimensional structure to examine the notion of shielding-effectiveness issues in a reverberating environment. Simulated mechanical stirring will be used to obtain the appropriate statistical field distribution. The shielding effectiveness (SE) in a simulated reverberating environment is compared to measurements in a reverberation chamber. A log-normal distribution for the SE is observed with implications for system designers. The work is intended to provide further refinement in the consideration of SE in a complex electromagnetic environment.

Wind Field Extractions from SAR Sentinel-1 Images Using Electromagnetic Models

NASA Astrophysics Data System (ADS)

La, Tran Vu; Khenchaf, Ali; Comblet, Fabrice; Nahum, Carole

2016-08-01

Among available wind sources, i.e. measured data, numeric weather models, the retrieval of wind vectors from Synthetic Aperture Radar (SAR) data / images is particularly preferred due to a lot of SAR systems (available data in most meteorological conditions, revisit mode, high resolution, etc.). For this purpose, the retrieval of wind vectors is principally based on the empirical (EP) models, e.g. CMOD series in C-band. Little studies have been reported about the use of the electromagnetic (EM) models for wind vector retrieval, since it is quite complicated to invert. However, the EM models can be applied for most cases of polarization, frequency and wind regime. In order to evaluate the advantages and limits of the EM models for wind vector retrieval, we compare in this study estimated results by the EM and EP models for both cases of polarization (vertical-vertical, or VV-pol and horizontal- horizontal, or HH-pol).

[Lossless ECG compression algorithm with anti- electromagnetic interference].

PubMed

Guan, Shu-An

2005-03-01

Based on the study of ECG signal features, a new lossless ECG compression algorithm is put forward here. We apply second-order difference operation with anti- electromagnetic interference to original ECG signals and then, compress the result by the escape-based coding model. In spite of serious 50Hz-interference, the algorithm is still capable of obtaining a high compression ratio.

Sensing network for electromagnetic fields generated by seismic activities

NASA Astrophysics Data System (ADS)

Gershenzon, Naum I.; Bambakidis, Gust; Ternovskiy, Igor V.

2014-06-01

The sensors network is becoming prolific and play now increasingly more important role in acquiring and processing information. Cyber-Physical Systems are focusing on investigation of integrated systems that includes sensing, networking, and computations. The physics of the seismic measurement and electromagnetic field measurement requires special consideration how to design electromagnetic field measurement networks for both research and detection earthquakes and explosions along with the seismic measurement networks. In addition, the electromagnetic sensor network itself could be designed and deployed, as a research tool with great deal of flexibility, the placement of the measuring nodes must be design based on systematic analysis of the seismic-electromagnetic interaction. In this article, we review the observations of the co-seismic electromagnetic field generated by earthquakes and man-made sources such as vibrations and explosions. The theoretical investigation allows the distribution of sensor nodes to be optimized and could be used to support existing geological networks. The placement of sensor nodes have to be determined based on physics of electromagnetic field distribution above the ground level. The results of theoretical investigations of seismo-electromagnetic phenomena are considered in Section I. First, we compare the relative contribution of various types of mechano-electromagnetic mechanisms and then analyze in detail the calculation of electromagnetic fields generated by piezomagnetic and electrokinetic effects.

A Proposal of B to B Collaboration Process Model based on a Concept of Service and its Application to Energy Saving Service Business

NASA Astrophysics Data System (ADS)

Zhang, Qi; Kosaka, Michitaka; Shirahada, Kunio; Yabutani, Takashi

This paper proposes a new framework for B to B collaboration process based on a concept of service. Service value, which gives users satisfaction for provided services, depends on the situation, user characteristics, and user objectives in seeking the service. Vargo proposed Service Dominant Logic (SDL), which determines service value according to “value in use”. This concept illustrates the importance of the relationship between the service itself and its situation. This relationship is analogous to electro-magnetic field theory in physics. We developed the concept of service fields to create service value based on an analogy of the electro-magnetic field. By applying this concept to B to B collaboration, a model of service value co-creation in the collaboration can be formulated. Then, the collaboration can be described by 4 steps of KIKI model (Knowledge sharing related to service system, Identification of service field, Knowledge creation for new service idea, Implementation of service idea). As its application to B to B collaboration, the energy saving service business is reported to demonstrate the validity of the proposed collaboration model. This concept can be applied to make a collaboration process effective.

LDRD Report: Topological Design Optimization of Convolutes in Next Generation Pulsed Power Devices.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cyr, Eric C.; von Winckel, Gregory John; Kouri, Drew Philip

This LDRD project was developed around the ambitious goal of applying PDE-constrained opti- mization approaches to design Z-machine components whose performance is governed by elec- tromagnetic and plasma models. This report documents the results of this LDRD project. Our differentiating approach was to use topology optimization methods developed for structural design and extend them for application to electromagnetic systems pertinent to the Z-machine. To achieve this objective a suite of optimization algorithms were implemented in the ROL library part of the Trilinos framework. These methods were applied to standalone demonstration problems and the Drekar multi-physics research application. Out of thismore » exploration a new augmented Lagrangian approach to structural design problems was developed. We demonstrate that this approach has favorable mesh-independent performance. Both the final design and the algorithmic performance were independent of the size of the mesh. In addition, topology optimization formulations for the design of conducting networks were developed and demonstrated. Of note, this formulation was used to develop a design for the inner magnetically insulated transmission line on the Z-machine. The resulting electromagnetic device is compared with theoretically postulated designs.« less

Reflector for efficient coupling of a laser beam to air or other fluids

DOEpatents

Kare, J.T.

1992-10-06

A reflector array is disclosed herein that provides a controlled region or regions of plasma breakdowns from a laser beam produced at a remotely-based laser source. The plasma may be applied to produce thrust to propel a spacecraft, or to diagnose a laser beam, or to produce shock waves. The spacecraft propulsion system comprises a reflector array attached to the vehicle. The reflector array comprises a plurality of reflectors spaced apart on a reflective surface, with each reflector acting as an independent focusing mirror. The reflectors are spaced closely together to form a continuous or partially-continuous surface. The reflector array may be formed from a sheet of reflective material, such as copper or aluminum. In operation, a beam of electromagnetic energy, such as a laser beam, is directed at the reflectors which focus the reflected electromagnetic energy at a plurality of regions off the surface. The energy concentrated in the focal region causes a breakdown of the air or other fluid in the focal region, creating a plasma. Electromagnetic energy is absorbed in the plasma and it grows in volume, compressing and heating the adjacent fluid thereby providing thrust. Laser pulses may be applied repetitively. After each such thrust pulse, fresh air can be introduced next to the surface either laterally, or through a perforated surface. If air or some other gas or vapor is supplied, for example from a tank carried on board a vehicle, this invention may also be used to provide thrust in a vacuum environment. 10 figs.

40 CFR 85.2225 - Steady state test exhaust analysis system-EPA 91.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Electromagnetic isolation and interference. Electromagnetic signals found in an automotive service environment may... instrument design must ensure that readings do not vary as a result of electromagnetic radiation and...

40 CFR 85.2225 - Steady state test exhaust analysis system-EPA 91.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Electromagnetic isolation and interference. Electromagnetic signals found in an automotive service environment may... instrument design must ensure that readings do not vary as a result of electromagnetic radiation and...

40 CFR 85.2225 - Steady state test exhaust analysis system-EPA 91.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Electromagnetic isolation and interference. Electromagnetic signals found in an automotive service environment may... instrument design must ensure that readings do not vary as a result of electromagnetic radiation and...

40 CFR 85.2225 - Steady state test exhaust analysis system-EPA 91.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Electromagnetic isolation and interference. Electromagnetic signals found in an automotive service environment may... instrument design must ensure that readings do not vary as a result of electromagnetic radiation and...

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

NASA Astrophysics Data System (ADS)

Smith, V.

2000-11-01

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

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

NASA Technical Reports Server (NTRS)

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

2000-01-01

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

Threats to ultra-high-field MRI

NASA Astrophysics Data System (ADS)

Le Bihan, Denis

2009-08-01

In 2004 the European Commission (EC) adopted a directive restricting occupational exposure to electromagnetic fields. This directive (2004/40/CE), which examines the possible health risks of the electromagnetic fields from mobile phones, Wi-Fi, Bluetooth and other devices, concluded that upper limits on radiation and applied electromagnetic fields are necessary to prevent workers from suffering any undue acute health effects. But although not initially intended, the biggest impact of the directive could be on magnetic resonance imaging (MRI), which is used in hospitals worldwide to produce images of unrivalled quality of the brain and other soft tissues.

Master equation for open two-band systems and its applications to Hall conductance

NASA Astrophysics Data System (ADS)

Shen, H. Z.; Zhang, S. S.; Dai, C. M.; Yi, X. X.

2018-02-01

Hall conductivity in the presence of a dephasing environment has recently been investigated with a dissipative term introduced phenomenologically. In this paper, we study the dissipative topological insulator (TI) and its topological transition in the presence of quantized electromagnetic environments. A Lindblad-type equation is derived to determine the dynamics of a two-band system. When the two-band model describes TIs, the environment may be the fluctuations of radiation that surround the TIs. We find the dependence of decay rates in the master equation on Bloch vectors in the two-band system, which leads to a mixing of the band occupations. Hence the environment-induced current is in general not perfectly topological in the presence of coupling to the environment, although deviations are small in the weak limit. As an illustration, we apply the Bloch-vector-dependent master equation to TIs and calculate the Hall conductance of tight-binding electrons in a two-dimensional lattice. The influence of environments on the Hall conductance is presented and discussed. The calculations show that the phase transition points of the TIs are robust against the quantized electromagnetic environment. The results might bridge the gap between quantum optics and topological photonic materials.

The polarization evolution of electromagnetic waves as a diagnostic method for a motional plasma

NASA Astrophysics Data System (ADS)

Shahrokhi, Alireza; Mehdian, Hassan; Hajisharifi, Kamal; Hasanbeigi, Ali

2017-12-01

The polarization evolution of electromagnetic (EM) radiation propagating through an electron beam-ion channel system is studied in the presence of self-magnetic field. Solving the fluid-Maxwell equations to obtain the medium dielectric tensor, the Stokes vector-Mueller matrix approach is employed to determine the polarization of the launched EM wave at any point in the propagation direction, applying the space-dependent Mueller matrix on the initial polarization vector of the wave at the plasma-vacuum interface. Results show that the polarization evolution of the wave is periodic in space along the beam axis with the specified polarization wavelength. Using the obtained results, a novel diagnostic method based on the polarization evolution of the EM waves is proposed to evaluate the electron beam density and velocity. Moreover, to use the mentioned plasma system as a polarizer, the fraction of the output radiation power transmitted through a motional plasma crossed with the input polarization is calculated. The results of the present investigation will greatly contribute to design a new EM amplifier with fixed polarization or EM polarizer, as well as a new diagnostic approach for the electron beam system where the polarimetric method is employed.

Electromagnetic navigated condylar positioning after high oblique sagittal split osteotomy of the mandible: a guided method to attain pristine temporomandibular joint conditions.

PubMed

Berger, Moritz; Nova, Igor; Kallus, Sebastian; Ristow, Oliver; Eisenmann, Urs; Dickhaus, Hartmut; Engel, Michael; Freudlsperger, Christian; Hoffmann, Jürgen; Seeberger, Robin

2018-05-01

Reproduction of the exact preoperative proximal-mandible position after osteotomy in orthognathic surgery is difficult to achieve. This clinical pilot study evaluated an electromagnetic (EM) navigation system for condylar positioning after high-oblique sagittal split osteotomy (HSSO). After HSSO as part of 2-jaw surgery, the position of 10 condyles was intraoperatively guided by an EM navigation system. As controls, 10 proximal segments were positioned by standard manual replacement. Accuracy was measured by pre- and postoperative cone beam computed tomography imaging. Overall, EM condyle repositioning was equally accurate compared with manual repositioning (P > .05). Subdivided into 3 axes, significant differences could be identified (P < .05). Nevertheless, no significantly and clinically relevant dislocations of the proximal segment of either the EM or the manual repositioning method could be shown (P > .05). This pilot study introduces a guided method for proximal segment positioning after HSSO by applying the intraoperative EM system. The data demonstrate the high accuracy of EM navigation, although manual replacement of the condyles could not be surpassed. However, EM navigation can avoid clinically hidden, severe malpositioning of the condyles. Copyright © 2017 Elsevier Inc. All rights reserved.

Successful application of frequency-domain airborne electromagnetic system with a grounded electric source

NASA Astrophysics Data System (ADS)

Kang, L.; Lin, J.; Liu, C.; Zhou, H.; Ren, T.; Yao, Y.

2017-12-01

A new frequency-domain AEM system with a grounded electric source, which was called ground-airborne frequency-domain electromagnetic (GAFEM) system, was proposed to extend penetration depth without compromising the resolution and detection efficiency. In GAFEM system, an electric source was placed on the ground to enlarge the strength of response signals. UVA was chosen as aircraft to reduce interaction noise and improve its ability to adapt to complex terrain. Multi-source and multi-frequency emission method has been researched and applied to improve the efficiency of GAFEM system. 2n pseudorandom sequence was introduced as transmitting waveform, to ensure resolution and detection efficiency. Inversion-procedure based on full-space apparent resistivity formula was built to realize GAFEM method and extend the survey area to non-far field. Based on GAFEM system, two application was conducted in Changchun, China, to map the deep conductive structure. As shown in the results of this exploration, GAFEM system shows its effectiveness to conductive structure, obtaining a depth of about 1km with a source-receiver distance of over 6km. And it shows the same level of resolution with CSAMT method with an over 10 times of efficiency. This extended a range of important applications where the terrain is too complex to be accessed or large penetration depth is required in a large survey area.

Detecting the position of the moving-iron solenoid by non-displacement sensor based on parameter identification of flux linkage characteristics

NASA Astrophysics Data System (ADS)

Wang, Xuping; Quan, Long; Xiong, Guangyu

2013-11-01

Currently, most researches use signals, such as the coil current or voltage of solenoid, to identify parameters; typically, parameter identification method based on variation rate of coil current is applied for position estimation. The problem exists in these researches that the detected signals are prone to interference and difficult to obtain. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which adds a new group of secondary winding to the coil of the ordinary switching electromagnet. On the basis of electromagnetic coupling theory analysis and simulation research of the magnetic field regarding the primary and secondary winding coils, and in accordance with the fact that under PWM control mode varying core position and operating current of windings produce different characteristic of flux increment of the secondary winding. The flux increment of the electromagnet winding can be obtained by conducting time domain integration for the induced voltage signal of the extracted secondary winding, and the core position from the two-dimensional fitting curve of the operating winding current and flux-linkage characteristic quantity of solenoid are calculated. The detecting and testing system of solenoid core position is developed based on the theoretical research. The testing results show that the flux characteristic quantity of switching electromagnet magnetic circuit is able to effectively show the core position and thus to accomplish the non-displacement transducer detection of the said core position of the switching electromagnet. This paper proposes a new method for detecting the core position by using flux characteristic quantity, which provides a new theory and method for switch solenoid to control the proportional valve.

Principle design and actuation of a dual chamber electromagnetic micropump with coaxial cantilever valves.

PubMed

Zordan, Enrico; Amirouche, Farid; Zhou, Yu

2010-02-01

This paper deals with the design and characterization of an electromagnetic actuation micropump with superimposed dual chambers. An integral part of microfluidic system includes micropumps which have become a critical design focus and have the potential to alter treatment and drug delivery requirements to patients. In this paper, conceptual design of variable geometrical nozzle/diffuser elements, coaxial cantilever valve, is proposed. It takes advantages of cantilever fluctuating valves with preset geometry to optimize and control fluid flow. The integration of this conceptual valve into a dual chamber micropump has increased the flow rate when compared to a single chamber micropump. This technique also allows for the fluid flow to be actively controlled by adjusting the movement of the intermediate membrane and the cantilever valves due to their fast response and large deflection properties when subjected to an electromagnetic field. To ensure reliability and performance of both the membrane and electromagnets, finite element method was used to perform the stress-strain analysis and optimize the membrane structure and electromagnet configuration. The frequency-dependent flow rates and backpressure are investigated for different frequencies by varying the applied currents from 1A to 1.75A. The current micropump design exhibits a backpressure of 58 mmH(2)O and has a water flow rate that reaches maximum at 1.985 ml/s under a 1.75A current with a resonance frequency of 45 Hz. This proposed micropump while at its initial prototype stage can satisfy the requirements of wide flow rate drug delivery applications. Its controllability and process design are attractive for high volume fabrication and low cost.

Morgantown People Mover Electromagnetic Compatibility Program

DOT National Transportation Integrated Search

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 ...

Information system building of the urban electromagnetic environment

NASA Astrophysics Data System (ADS)

Wang, Jiechen; Rui, Yikang; Shen, Dingtao; Yu, Qing

2007-06-01

The pollution of urban electromagnetic radiation has become more serious, however, there is still lack of a perfect and interactive User System to manage, analyze and issue the information. In this study, taking the electromagnetic environment of Nanjing as an example, an information system based on WebGIS with the techniques of ArcIMS and JSP has been developed, in order to provide the services and technique supports for information query of public and decision making of relevant departments.

3-D Electromagnetic field analysis of wireless power transfer system using K computer

NASA Astrophysics Data System (ADS)

Kawase, Yoshihiro; Yamaguchi, Tadashi; Murashita, Masaya; Tsukada, Shota; Ota, Tomohiro; Yamamoto, Takeshi

2018-05-01

We analyze the electromagnetic field of a wireless power transfer system using the 3-D parallel finite element method on K computer, which is a super computer in Japan. It is clarified that the electromagnetic field of the wireless power transfer system can be analyzed in a practical time using the parallel computation on K computer, moreover, the accuracy of the loss calculation becomes better as the mesh division of the shield becomes fine.

Comparison of Precision between Optical and Electromagnetic Navigation Systems in Total Knee Arthroplasty

PubMed Central

Rhee, Seung Joon; Park, Shi Hwan; Cho, He Myung

2014-01-01

Purpose The purpose of this study is to compare and analyze the precision of optical and electromagnetic navigation systems in total knee arthroplasty (TKA). Materials and Methods We retrospectively reviewed 60 patients who underwent TKA using an optical navigation system and 60 patients who underwent TKA using an electromagnetic navigation system from June 2010 to March 2012. The mechanical axis that was measured on preoperative radiographs and by the intraoperative navigation systems were compared between the groups. The postoperative positions of the femoral and tibial components in the sagittal and coronal plane were assessed. Results The difference of the mechanical axis measured on the preoperative radiograph and by the intraoperative navigation systems was 0.6 degrees more varus in the electromagnetic navigation system group than in the optical navigation system group, but showed no statistically significant difference between the two groups (p>0.05). The positions of the femoral and tibial components in the sagittal and coronal planes on the postoperative radiographs also showed no statistically significant difference between the two groups (p>0.05). Conclusions In TKA, both optical and electromagnetic navigation systems showed high accuracy and reproducibility, and the measurements from the postoperative radiographs showed no significant difference between the two groups. PMID:25505703

Optimization of an electromagnetic linear actuator using a network and a finite element model

NASA Astrophysics Data System (ADS)

Neubert, Holger; Kamusella, Alfred; Lienig, Jens

2011-03-01

Model based design optimization leads to robust solutions only if the statistical deviations of design, load and ambient parameters from nominal values are considered. We describe an optimization methodology that involves these deviations as stochastic variables for an exemplary electromagnetic actuator used to drive a Braille printer. A combined model simulates the dynamic behavior of the actuator and its non-linear load. It consists of a dynamic network model and a stationary magnetic finite element (FE) model. The network model utilizes lookup tables of the magnetic force and the flux linkage computed by the FE model. After a sensitivity analysis using design of experiment (DoE) methods and a nominal optimization based on gradient methods, a robust design optimization is performed. Selected design variables are involved in form of their density functions. In order to reduce the computational effort we use response surfaces instead of the combined system model obtained in all stochastic analysis steps. Thus, Monte-Carlo simulations can be applied. As a result we found an optimum system design meeting our requirements with regard to function and reliability.

Directly tailoring photon-electron coupling for sensitive photoconductance

NASA Astrophysics Data System (ADS)

Huang, Zhiming; Zhou, Wei; Huang, Jingguo; Wu, Jing; Gao, Yanqing; Qu, Yue; Chu, Junhao

2016-03-01

The coupling between photons and electrons is at the heart of many fundamental phenomena in nature. Despite tremendous advances in controlling electrons by photons in engineered energy-band systems, control over their coupling is still widely lacking. Here we demonstrate an unprecedented ability to couple photon-electron interactions in real space, in which the incident electromagnetic wave directly tailors energy bands of solid to generate carriers for sensitive photoconductance. By spatially coherent manipulation of metal-wrapped material system through anti-symmetric electric field of the irradiated electromagnetic wave, electrons in the metals are injected and accumulated in the induced potential well (EIW) produced in the solid. Respective positive and negative electric conductances are easily observed in n-type and p-type semiconductors into which electrons flow down from the two metallic sides under light irradiation. The photoconductivity is further confirmed by sweeping the injected electrons out of the semiconductor before recombination applied by sufficiently strong electric fields. Our work opens up new perspectives for tailoring energy bands of solids and is especially relevant to develop high effective photon detection, spin injection, and energy harvesting in optoelectronics and electronics.

Concepts in Electromagnetic Scattering for Particulate-Systems Characterization

DTIC Science & Technology

2013-04-29

scientists attended and 19 presentations were given. Specific topics included remote sensing, polarimetry , analytic and numeric electromagnetic...presentations were given. Specific topics included remote sensing, polarimetry , ana- lytic and numeric electromagnetic theory, camouflage in nature

Microscale Electromagnetic Heating in Heterogeneous Energetic Materials Based on X-ray Computed Tomography

NASA Astrophysics Data System (ADS)

Kort-Kamp, W. J. M.; Cordes, N. L.; Ionita, A.; Glover, B. B.; Duque, A. L. Higginbotham; Perry, W. L.; Patterson, B. M.; Dalvit, D. A. R.; Moore, D. S.

2016-04-01

Electromagnetic stimulation of energetic materials provides a noninvasive and nondestructive tool for detecting and identifying explosives. We combine structural information based on x-ray computed tomography, experimental dielectric data, and electromagnetic full-wave simulations to study microscale electromagnetic heating of realistic three-dimensional heterogeneous explosives. We analyze the formation of electromagnetic hot spots and thermal gradients in the explosive-binder mesostructures and compare the heating rate for various binder systems.

Working principle of an electromagnetic wiping system

NASA Astrophysics Data System (ADS)

Ernst, R.; Fautrelle, Y.; Bianchi, A.-M.; Iliescu, M.

2009-03-01

In galvanizing lines, the gas knife wiping device works well for controlling the zinc coating thickness up to 2 to 3 m/s strip velocities. But for higher velocities, a strong liquid zinc splash risk forbids the gas pressure increase, which would be necessary to keep the same thickness control efficiency of the knives. That is why a complementary electromagnetic wiping system, whose purpose is to pre-wipe the liquid zinc before the gas knives take over, is presented here. After mentioning different kinds of AC and DC possible electromagnetic solutions, a DC field electromagnetic brake (EMB) system based on the use of permanent magnets is selected for a future experimental implementation. In order to better understand the electromagnetic and fluid mechanics phenomena, an analytical model and then different numerical models are presented here. These models show an interesting wiping effect on the liquid zinc, which seems promising for a future experimental pilot design. Figs 8, Refs 9.

Electromagnetic holographic sensitivity field of two-phase flow in horizontal wells

NASA Astrophysics Data System (ADS)

Zhang, Kuo; Wu, Xi-Ling; Yan, Jing-Fu; Cai, Jia-Tie

2017-03-01

Electromagnetic holographic data are characterized by two modes, suggesting that image reconstruction requires a dual-mode sensitivity field as well. We analyze an electromagnetic holographic field based on tomography theory and Radon inverse transform to derive the expression of the electromagnetic holographic sensitivity field (EMHSF). Then, we apply the EMHSF calculated by using finite-element methods to flow simulations and holographic imaging. The results suggest that the EMHSF based on the partial derivative of radius of the complex electric potential φ is closely linked to the Radon inverse transform and encompasses the sensitivities of the amplitude and phase data. The flow images obtained with inversion using EMHSF better agree with the actual flow patterns. The EMHSF overcomes the limitations of traditional single-mode sensitivity fields.

Modeling of electromagnetic brakes for enhanced braking capabilities

NASA Astrophysics Data System (ADS)

Kachroo, Pushkin; Ming, Qian

1998-01-01

In automatic highway systems, automatic brake actuation is a very important part of the overall control of the vehicle. Hence, a faster response and a robust braking system are crucial. This paper describes electromagnetic brakes as a supplementary system for regular friction brakes. This system provides better response time for emergency situations, and in general keeps the friction brake working longer and safer. A new mathematical model for electromagnetic brakes is proposed to describe their static characteristics. The performance of the new mathematical model is better than the other three models available in the literature.

Helical and tubular lipid microstructures that are electroless-coated with CoNiReP for wireless magnetic manipulation.

PubMed

Schuerle, Simone; Pané, Salvador; Pellicer, Eva; Sort, Jordi; Baró, Maria D; Nelson, Bradley J

2012-05-21

Hybrid magnetic phospholipidic-based tubular and helical microagents are wirelessly manipulated by means of a 5-DOF electromagnetic system. Two different strategies are used to manipulate these nanostructures in simulated biologic capillaries. Tubules are pulled by applying magnetic field gradients and oriented by magnetic fields. Helices exhibit a cork-screw motion similar to the swimming strategy used by motile bacteria such as E. coli. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Approach to intraoperative electromagnetic navigation in orthognathic surgery: A phantom skull based trial.

PubMed

Berger, Moritz; Kallus, Sebastian; Nova, Igor; Ristow, Oliver; Eisenmann, Urs; Dickhaus, Hartmut; Kuhle, Reinald; Hoffmann, Jürgen; Seeberger, Robin

2015-11-01

Intraoperative guidance using electromagnetic navigation is an upcoming method in maxillofacial surgery. However, due to their unwieldy structures, especially the line-of-sight problem, optical navigation devices are not used for daily orthognathic surgery. Therefore, orthognathic surgery was simulated on study phantom skulls, evaluating the accuracy and handling of a new electromagnetic tracking system. Le-Fort I osteotomies were performed on 10 plastic skulls. Orthognathic surgical planning was done in the conventional way using plaster models. Accuracy of the gold standard, splint-based model surgery versus an electromagnetic tracking system was evaluated by measuring the actual maxillary deviation using bimaxillary splints and preoperative and postoperative cone beam computer tomography imaging. The distance of five anatomical marker points were compared pre- and postoperatively. The electromagnetic tracking system was significantly more accurate in all measured parameters compared with the gold standard using bimaxillary splints (p < 0.01). The data shows a discrepancy between the model surgical plans and the actual correction of the upper jaw of 0.8 mm. Using the electromagnetic tracking, we could reduce the discrepancy of the maxillary transposition between the planned and actual orthognathic surgery to 0.3 mm on average. The data of this preliminary study shows a high level of accuracy in surgical orthognathic performance using electromagnetic navigation, and may offer greater precision than the conventional plaster model surgery with bimaxillary splints. This preliminary work shows great potential for the establishment of an intraoperative electromagnetic navigation system for maxillofacial surgery. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Bi-Level Demand-Sensitive LED Street Lighting Systems

DTIC Science & Technology

2013-10-01

Hazards of Electromagnetic Radiation to Fuel HERO : Hazards of Electromagnetic Radiation to Ordnance ...we followed the following guidelines very strictly: 68 • For Hazards of Electromagnetic Radiation to Ordnance (HERO), RF device to be brought in...should be used at least 5 feet from ordnance /explosives. • For, Hazards of Electromagnetic Radiation to Personnel (HERP), HERP Controlled and

Flat profile laser beam shaper

DOEpatents

Johnson, Todd R.

2017-09-12

A system for shaping a beam comprises an emitter for emitting coherent electromagnetic radiation. Birefringent displacers are configured between the emitter and a target wherein the at least two birefringent displacers split the coherent electromagnetic radiation into a plurality of coherent parallel beams of electromagnetic radiation thereby producing a shaped wave front of the coherent parallel beams of electromagnetic radiation.

Binary black holes' effects on electromagnetic fields.

PubMed

Palenzuela, Carlos; Anderson, Matthew; Lehner, Luis; Liebling, Steven L; Neilsen, David

2009-08-21

In addition to producing gravitational waves, the dynamics of a binary black hole system could induce emission of electromagnetic radiation by affecting the behavior of plasmas and electromagnetic fields in their vicinity. We here study how the electromagnetic fields are affected by a pair of orbiting black holes through the merger. In particular, we show how the binary's dynamics induce a variability in possible electromagnetically induced emissions as well as a possible enhancement of electromagnetic fields during the late-merge and merger epochs. These time dependent features will likely leave their imprint in processes generating detectable emissions and can be exploited in the detection of electromagnetic counterparts of gravitational waves.

Decoupling suspension controller based on magnetic flux feedback.

PubMed

Zhang, Wenqing; Li, Jie; Zhang, Kun; Cui, Peng

2013-01-01

The suspension module control system model has been established based on MIMO (multiple input and multiple output) state feedback linearization. We have completed decoupling between double suspension points, and the new decoupling method has been applied to CMS04 magnetic suspension vehicle in national mid-low-speed maglev experiment field of Tangshan city in China. Double suspension system model is very accurate for investigating stability property of maglev control system. When magnetic flux signal is taken back to the suspension control system, the suspension module's antijamming capacity for resisting suspension load variety has been proved. Also, the external force interference has been enhanced. As a result, the robustness and stability properties of double-electromagnet suspension control system have been enhanced.

Decoupling Suspension Controller Based on Magnetic Flux Feedback

PubMed Central

Zhang, Wenqing; Li, Jie; Zhang, Kun; Cui, Peng

2013-01-01

The suspension module control system model has been established based on MIMO (multiple input and multiple output) state feedback linearization. We have completed decoupling between double suspension points, and the new decoupling method has been applied to CMS04 magnetic suspension vehicle in national mid-low-speed maglev experiment field of Tangshan city in China. Double suspension system model is very accurate for investigating stability property of maglev control system. When magnetic flux signal is taken back to the suspension control system, the suspension module's antijamming capacity for resisting suspension load variety has been proved. Also, the external force interference has been enhanced. As a result, the robustness and stability properties of double-electromagnet suspension control system have been enhanced. PMID:23844415

Liquid Level Sensing System

NASA Technical Reports Server (NTRS)

Korman, Valentin (Inventor); Wiley, John T. (Inventor); Duffell, Amanda G. (Inventor)

2014-01-01

A liquid level sensing system includes waveguides disposed in a liquid and distributed along a path with a gap between adjacent waveguides. A source introduces electromagnetic energy into the waveguides at a first end of the path. A portion of the electromagnetic energy exits the waveguides at a second end of the path. A detector measures the portion of the electromagnetic energy exiting the second end of the path.

16TH Annual Review of Progress in Applied Computational Electromagnetics of the Naval Postgraduate School, Monterey, CA. Volume I

DTIC Science & Technology

2000-03-24

Element Method for Designing Plasma Reactors" Leo Kempel, Paul Rummel, Tim Grotjohn and John Amrhein ............................................ 28...34Finite Element Method for Designing Plasma Reactors" Leo Kempel, Paul Rummel, Tim Grotjohn and John Amrhein...548 "lime-Domain Simulation of Electromagnetic Wave Propagation in a Magnetized Plasma" J. Paul , C. Christopoulos, and

Conference Proceedings: 7th Annual Review of Progress in Applied Computational Electromagnetics at the Naval Postgraduate School, Monterey, California, March 18-22, 1991

DTIC Science & Technology

1991-03-01

34Volume integral Equations and Conjugate Gradient Methods in Electromagnetic Non destructive Evaluation’ by Dr. Harold P.. Sabbagh, Sabbagh Associates...8217 Experimental Demonstrations far teaching Electroamgnetic Folods and Energy’ M. Zathn, J. Mectrer...8217-....................................... . ...................................................... 329 ’PoalarimetrIc Scattering and Control at Radar Crass Section of Chirat Targets at Simple

Motion of dust in a planetary magnetosphere - Orbit-averaged equations for oblateness, electromagnetic, and radiation forces with application to Saturn's E ring

NASA Technical Reports Server (NTRS)

Hamilton, Douglas P.

1993-01-01

The orbital dynamics of micrometer-sized dust grains is explored numerically and analytically, treating the strongest perturbation forces acting on close circumplanetary dust grains: higher-order gravity, radiation pressure, and the electromagnetic force. The appropriate orbit-average equations are derived and applied to the E ring. Arguments are made for the existence of azimuthal and vertical asymmetries in the E ring. New understanding of the dynamics of E ring dust grains is applied to problems of the ring's breadth and height. The possibility for further ground-based and spacecraft observations is considered.

A NOVEL TECHNIQUE APPLYING SPECTRAL ESTIMATION TO JOHNSON NOISE THERMOMETRY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ezell, N Dianne Bull; Britton Jr, Charles L; Roberts, Michael

Johnson noise thermometry (JNT) is one of many important measurements used to monitor the safety levels and stability in a nuclear reactor. However, this measurement is very dependent on the electromagnetic environment. Properly removing unwanted electromagnetic interference (EMI) is critical for accurate drift free temperature measurements. The two techniques developed by Oak Ridge National Laboratory (ORNL) to remove transient and periodic EMI are briefly discussed in this document. Spectral estimation is a key component in the signal processing algorithm utilized for EMI removal and temperature calculation. Applying these techniques requires the simple addition of the electronics and signal processing tomore » existing resistive thermometers.« less

Influence of a source line position on results of EM observations applied to the diagnostics of underground heating system pipelines in urban area

NASA Astrophysics Data System (ADS)

Vetrov, A.

2009-05-01

The condition of underground constructions, communication and supply systems in the cities has to be periodically monitored and controlled in order to prevent their breakage, which can result in serious accident, especially in urban area. The most risk of damage have the underground construction made of steal such as pipelines widely used for water, gas and heat supply. To ensure the pipeline survivability it is necessary to carry out the operative and inexpensive control of pipelines condition. Induced electromagnetic methods of geophysics can be applied to provide such diagnostics. The highly developed surface in urbane area is one of cause hampering the realization of electromagnetic methods of diagnostics. The main problem is in finding of an appropriate place for the source line and electrodes on a limited surface area and their optimal position relative to the observation path to minimize their influence on observed data. Author made a number of experiments of an underground heating system pipeline diagnostics using different position of the source line and electrodes. The experiments were made on a 200 meters section over 2 meters deep pipeline. The admissible length of the source line and angle between the source line and the observation path were determined. The minimal length of the source line for the experiment conditions and accuracy made 30 meters, the maximum admissible angle departure from the perpendicular position made 30 degrees. The work was undertaken in cooperation with diagnostics company DIsSO, Saint-Petersburg, Russia.

System and Method for Obtaining Simultaneous Levitation and Rotation of a Ferromagnetic Object

NASA Astrophysics Data System (ADS)

Banerjee, Subrata; Sarkar, Mrinal Kanti; Ghosh, Arnab

2017-02-01

In this work a practical demonstration for simultaneous levitation and rotation for a ferromagnetic cylindrical object is presented. A hollow steel cylinder has been arranged to remain suspended stably under I-core electromagnet utilizing dc attraction type levitation principle and then arranged to rotate the levitated object around 1000 rpm speed based on eddy current based energy meter principle. Since the object is to be rotating during levitated condition the device will be frictionless, energy-efficient and robust. This technology may be applied to frictionless energy meter, wind turbine, machine tool applications, precision instruments and many other devices where easy energy-efficient stable rotation will be required. The cascade lead compensation control scheme has been applied for stabilization of unstable levitation system. The proposed device is successfully tested in the laboratory and experimental results have been produced.

Methods for removing contaminant matter from a porous material

DOEpatents

Fox, Robert V [Idaho Falls, ID; Avci, Recep [Bozeman, MT; Groenewold, Gary S [Idaho Falls, ID

2010-11-16

Methods of removing contaminant matter from porous materials include applying a polymer material to a contaminated surface, irradiating the contaminated surface to cause redistribution of contaminant matter, and removing at least a portion of the polymer material from the surface. Systems for decontaminating a contaminated structure comprising porous material include a radiation device configured to emit electromagnetic radiation toward a surface of a structure, and at least one spray device configured to apply a capture material onto the surface of the structure. Polymer materials that can be used in such methods and systems include polyphosphazine-based polymer materials having polyphosphazine backbone segments and side chain groups that include selected functional groups. The selected functional groups may include iminos, oximes, carboxylates, sulfonates, .beta.-diketones, phosphine sulfides, phosphates, phosphites, phosphonates, phosphinates, phosphine oxides, monothio phosphinic acids, and dithio phosphinic acids.

The Radio Frequency Fragment Separator for Rare Isotope Beams at the NSCL

NASA Astrophysics Data System (ADS)

Stoker, Joshua; Andreev, Vladimir; Bazin, Daniel; Becerril, Ana; Doleans, Marc; Gorelov, Dimitry; Glennon, Patrick; Grimm, Terry; Lawton, Don; Mantica, Paul; Marti, Felix; Ottarson, Jack; Schatz, Hendrik; Vincent, John; Wagner, Jim; Wu, Xiaoyu; Zeller, Al

2006-10-01

Secondary beams at the National Superconducting Cyclotron Laboratory (NSCL) are separated through a combined application of magnetic rigidity and energy loss filtering. Design and construction of a Radio Frequency Fragment Separator (RFFS) for further beam purification is underway. The RFFS will apply a time-varying electromagnetic field to induce transverse beam separation. This method relies on velocity differences of the beam species to selectivey apply separation to unwanted fragments. The technical design of the RFFS and the expected purification of exotic beams are shown in detail[1]. [1] Gorelev, D. et al., ``RF Kicker System for Secondary Beams at the NSCL'' Proc of Part Accel Conf 2005, Knoxville, TN

Microscale electromagnetic heating in heterogeneous energetic materials based on x-ray computed tomography

DOE PAGES

Kort-Kamp, W. J. M.; Cordes, N. L.; Ionita, A.; ...

2016-04-01

Electromagnetic stimulation of energetic materials provides a noninvasive and nondestructive tool for detecting and identifying explosives. We combine structural information based on x-ray computed tomography, experimental dielectric data, and electromagnetic full-wave simulations to study microscale electromagnetic heating of realistic three-dimensional heterogeneous explosives. In conclusion, we analyze the formation of electromagnetic hot spots and thermal gradients in the explosive-binder mesostructures and compare the heating rate for various binder systems.

Microscale electromagnetic heating in heterogeneous energetic materials based on x-ray computed tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kort-Kamp, W. J. M.; Cordes, N. L.; Ionita, A.

Electromagnetic stimulation of energetic materials provides a noninvasive and nondestructive tool for detecting and identifying explosives. We combine structural information based on x-ray computed tomography, experimental dielectric data, and electromagnetic full-wave simulations to study microscale electromagnetic heating of realistic three-dimensional heterogeneous explosives. In conclusion, we analyze the formation of electromagnetic hot spots and thermal gradients in the explosive-binder mesostructures and compare the heating rate for various binder systems.

Detection of buried targets using a new enhanced very early time electromagnetic (VETEM) prototype system

USGS Publications Warehouse

Cui, T.J.; Chew, W.C.; Aydiner, A.A.; Wright, D.L.; Smith, D.V.

2001-01-01

In this paper, numerical simulations of a new enhanced very early time electromagnetic (VETEM) prototype system are presented, where a horizontal transmitting loop and two horizontal receiving loops are used to detect buried targets, in which three loops share the same axis and the transmitter is located at the center of receivers. In the new VETEM system, the difference of signals from two receivers is taken to eliminate strong direct-signals from the transmitter and background clutter and furthermore to obtain a better SNR for buried targets. Because strong coupling exists between the transmitter and receivers, accurate analysis of the three-loop antenna system is required, for which a loop-tree basis function method has been utilized to overcome the low-frequency breakdown problem. In the analysis of scattering problem from buried targets, a conjugate gradient (CG) method with fast Fourier transform (FFT) is applied to solve the electric field integral equation. However, the convergence of such CG-FFT algorithm is extremely slow at very low frequencies. In order to increase the convergence rate, a frequency-hopping approach has been used. Finally, the primary, coupling, reflected, and scattered magnetic fields are evaluated at receiving loops to calculate the output electric current. Numerous simulation results are given to interpret the new VETEM system. Comparing with other single-transmitter-receiver systems, the new VETEM has better SNR and ability to reduce the clutter.

Superconducting magnetic energy storage and superconducting self-supplied electromagnetic launcher

NASA Astrophysics Data System (ADS)

Ciceron, Jérémie; Badel, Arnaud; Tixador, Pascal

2017-10-01

Superconductors can be used to build energy storage systems called Superconducting Magnetic Energy Storage (SMES), which are promising as inductive pulse power source and suitable for powering electromagnetic launchers. The second generation of high critical temperature superconductors is called coated conductors or REBCO (Rare Earth Barium Copper Oxide) tapes. Their current carrying capability in high magnetic field and their thermal stability are expanding the SMES application field. The BOSSE (Bobine Supraconductrice pour le Stockage d'Energie) project aims to develop and to master the use of these superconducting tapes through two prototypes. The first one is a SMES with high energy density. Thanks to the performances of REBCO tapes, the volume energy and specific energy of existing SMES systems can be surpassed. A study has been undertaken to make the best use of the REBCO tapes and to determine the most adapted topology in order to reach our objective, which is to beat the world record of mass energy density for a superconducting coil. This objective is conflicting with the classical strategies of superconducting coil protection. A different protection approach is proposed. The second prototype of the BOSSE project is a small-scale demonstrator of a Superconducting Self-Supplied Electromagnetic Launcher (S3EL), in which a SMES is integrated around the launcher which benefits from the generated magnetic field to increase the thrust applied to the projectile. The S3EL principle and its design are presented. Contribution to the topical issue "Electrical Engineering Symposium (SGE 2016)", edited by Adel Razek

Electricity generation using electromagnetic radiation

DOEpatents

Halas, Nancy J.; Nordlander, Peter; Neumann, Oara

2017-08-22

In general, in one aspect, the invention relates to a system to create vapor for generating electric power. The system includes a vessel comprising a fluid and a complex and a turbine. The vessel of the system is configured to concentrate EM radiation received from an EM radiation source. The vessel of the system is further configured to apply the EM radiation to the complex, where the complex absorbs the EM radiation to generate heat. The vessel of the system is also configured to transform, using the heat generated by the complex, the fluid to vapor. The vessel of the system is further configured to sending the vapor to a turbine. The turbine of the system is configured to receive, from the vessel, the vapor used to generate the electric power.

Deep prospecting electromagnetic system and its application

NASA Astrophysics Data System (ADS)

Lin, J.; Liu, C.; Zhou, F.; Zhang, W.; Chen, J.; Xue, K.; Sun, C.; Xu, W.; Hu, R.

2011-12-01

Today mineral resource is becoming the impediment to the society development because less and less mineral resource can be available. People are trying all kinds of technological tools to find the mineral deposit concealed in deep lithosphere. Unfortunately, current technology can not meet the exploration requirement completely and it is still difficult to know whether a deep mineral deposit exists and how it is presented at a considered site. In order to meet the requirement of discovering the mineral deposit in the second mine prospecting space (500-2000m under earth surface), we developed a deep prospecting electromagnetic system (DPS-I). This system consists of an electromagnetic receiver array and a high-power transmitter. The receiver array consists of 24 sub-receivers and one controller and has up to 53 electromagnetic channels. The sub-receivers can be extended conveniently if the user would like and they communicate with the controller through a cable or wireless antenna. When the channel interval is set to typical value of 50 m, the system can cover 2500 m survey line at one arrangement with two magnetic records. Since the signals are collected at the same time some disturbances, such as time variable but space invariable noise, will be suppressed because they have almost the same effect to all channels. The transmitter is designed to be 45 KW of upper power limit so that strong signals will be detected. Series transmission technology is adopted to avoid unwieldiness of transmitter. In fact it is made of three portable transmission units and each one can work independently. The system can transmit several kinds of waves and records all samples of signals in time sequences. So it can work for different electromagnetic methods. The prior methods for our application are the combination of IP, CSAMT and MT. Utilizing joint inversion and model restriction, we can obtain more refined model at large depth than conventional exploration. We have applied this system in China to detect nickel ore, iron ore, geothermic water and formation buried in deep earth successfully with high resolution power and the largest depth of investigation exceeded 2000 m. The nickel ore is located at Hongqiling hill, Jilin province. The depth of its top surface is about 600 m and that of its bottom surface is about 900 m. The iron ore is located at Dataigou, Liaoning province. Its top surface is buried about 1200 m beneath the ground and its bottom surface is still not assured because the deepest bore didn't reach its bottom. According to the known information, the bottom surface is inferred to be deeper than 2000 m. The geothermic water is buried deeply about 1600 m beneath the ground, located at Baishan, Jilin province. A bore of 2200 m depth was dilled after our exploration and hot water flowed out from the bore. Although several power lines exist nearby the survey lines, we still observed obvious signals and find low resistivity region at the place where the ore and the water exist. These experiments show that our electromagnetic system is successful.

Laboratory test methodology for evaluating the effects of electromagnetic disturbances on fault-tolerant control systems

NASA Technical Reports Server (NTRS)

Belcastro, Celeste M.

1989-01-01

Control systems for advanced aircraft, especially those with relaxed static stability, will be critical to flight and will, therefore, have very high reliability specifications which must be met for adverse as well as nominal operating conditions. Adverse conditions can result from electromagnetic disturbances caused by lightning, high energy radio frequency transmitters, and nuclear electromagnetic pulses. Tools and techniques must be developed to verify the integrity of the control system in adverse operating conditions. The most difficult and illusive perturbations to computer based control systems caused by an electromagnetic environment (EME) are functional error modes that involve no component damage. These error modes are collectively known as upset, can occur simultaneously in all of the channels of a redundant control system, and are software dependent. A methodology is presented for performing upset tests on a multichannel control system and considerations are discussed for the design of upset tests to be conducted in the lab on fault tolerant control systems operating in a closed loop with a simulated plant.

Data Analysis of Airborne Electromagnetic Bathymetry.

DTIC Science & Technology

1985-04-01

7 AD-R 58 889 DATA ANALYSIS OF AIRBORNE ELECTROMAGNETIC BRTHYMETRY i/i (U) NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY NSTL STRTION MS R ZOLLINGER...Naval Ocean Research and Development Activity NSTL, Mississippi 39529 NORDA Report 93 April 1985 AD-A158 809 - Data Analysis of Airborne Electromagnetic ...8217 - Foreword CI Airborne electromagnetic (AEM) systems have traditionally been used for detecting anomalous conductors in the

Base-Level Guide for Electromagnetic Frequency Radiation

DTIC Science & Technology

2012-12-01

hazards of EMF-producing systems and equipment, e.g., hazard of electromagnetic radiation to ordnance (HERO), and hazard ...AFRL-SA-WP-SR-2013-0003 BASE-LEVEL GUIDE FOR ELECTROMAGNETIC FREQUENCY RADIATION Matthew W. Uelen Battelle Memorial Institute...COVERED (From – To) Dec 2011 – Dec 2012 4. TITLE AND SUBTITLE Base-Level Guide for Electromagnetic Frequency Radiation 5a. CONTRACT NUMBER

Architecting the Safety Assessment of Large-scale Systems Integration

DTIC Science & Technology

2009-12-01

Electromagnetic Radiation to Ordnance ( HERO )  Hazards of Electromagnetic Radiation to Fuel (HERF) The main reason that this particular safety study... radiation , high voltage electric shocks and explosives safety. 1. Radiation Hazards (RADHAZ) RADHAZ describes the hazards of electromagnetic radiation ...OP3565/NAVAIR 16-1-529 [19 and 20], these hazards are segregated as follows:  Hazards of Electromagnetic

Generalized theoretical method for the interaction between arbitrary nonuniform electric field and molecular vibrations: Toward near-field infrared spectroscopy and microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iwasa, Takeshi, E-mail: tiwasa@mail.sci.hokudai.ac.jp; Takenaka, Masato; Taketsugu, Tetsuya

A theoretical method to compute infrared absorption spectra when a molecule is interacting with an arbitrary nonuniform electric field such as near-fields is developed and numerically applied to simple model systems. The method is based on the multipolar Hamiltonian where the light-matter interaction is described by a spatial integral of the inner product of the molecular polarization and applied electric field. The computation scheme is developed under the harmonic approximation for the molecular vibrations and the framework of modern electronic structure calculations such as the density functional theory. Infrared reflection absorption and near-field infrared absorption are considered as model systems.more » The obtained IR spectra successfully reflect the spatial structure of the applied electric field and corresponding vibrational modes, demonstrating applicability of the present method to analyze modern nanovibrational spectroscopy using near-fields. The present method can use arbitral electric fields and thus can integrate two fields such as computational chemistry and electromagnetics.« less

Generalized theoretical method for the interaction between arbitrary nonuniform electric field and molecular vibrations: Toward near-field infrared spectroscopy and microscopy.

PubMed

Iwasa, Takeshi; Takenaka, Masato; Taketsugu, Tetsuya

2016-03-28

A theoretical method to compute infrared absorption spectra when a molecule is interacting with an arbitrary nonuniform electric field such as near-fields is developed and numerically applied to simple model systems. The method is based on the multipolar Hamiltonian where the light-matter interaction is described by a spatial integral of the inner product of the molecular polarization and applied electric field. The computation scheme is developed under the harmonic approximation for the molecular vibrations and the framework of modern electronic structure calculations such as the density functional theory. Infrared reflection absorption and near-field infrared absorption are considered as model systems. The obtained IR spectra successfully reflect the spatial structure of the applied electric field and corresponding vibrational modes, demonstrating applicability of the present method to analyze modern nanovibrational spectroscopy using near-fields. The present method can use arbitral electric fields and thus can integrate two fields such as computational chemistry and electromagnetics.

Multiple Frequency Contrast Source Inversion Method for Vertical Electromagnetic Profiling: 2D Simulation Results and Analyses

NASA Astrophysics Data System (ADS)

Li, Jinghe; Song, Linping; Liu, Qing Huo

2016-02-01

A simultaneous multiple frequency contrast source inversion (CSI) method is applied to reconstructing hydrocarbon reservoir targets in a complex multilayered medium in two dimensions. It simulates the effects of a salt dome sedimentary formation in the context of reservoir monitoring. In this method, the stabilized biconjugate-gradient fast Fourier transform (BCGS-FFT) algorithm is applied as a fast solver for the 2D volume integral equation for the forward computation. The inversion technique with CSI combines the efficient FFT algorithm to speed up the matrix-vector multiplication and the stable convergence of the simultaneous multiple frequency CSI in the iteration process. As a result, this method is capable of making quantitative conductivity image reconstruction effectively for large-scale electromagnetic oil exploration problems, including the vertical electromagnetic profiling (VEP) survey investigated here. A number of numerical examples have been demonstrated to validate the effectiveness and capacity of the simultaneous multiple frequency CSI method for a limited array view in VEP.

Calculation of electromagnetic force in electromagnetic forming process of metal sheet

NASA Astrophysics Data System (ADS)

Xu, Da; Liu, Xuesong; Fang, Kun; Fang, Hongyuan

2010-06-01

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

Avionics System Design for High Energy Fields

DTIC Science & Technology

1988-07-01

this report describes design practices which will lead to reducc electromagnetic susceptibility of avionics systems in high energy fields . A second...nuclear reactions. Tn most cases the radiation which causes electromagnetic interference Is completely harmless to humans . Many techniqteq are used in...variety of electromagnetic compatibility problems. 1,e fIrst use EMCad to preeict the field strength from a discharge. Next, we usc’e r. a second

Non-Existence of Black Hole Solutionsfor a Spherically Symmetric, Static Einstein-Dirac-Maxwell System

NASA Astrophysics Data System (ADS)

Finster, Felix; Smoller, Joel; Yau, Shing-Tung

We consider for j=1/2, 3/2,... a spherically symmetric, static system of (2j+1) Dirac particles, each having total angular momentum j. The Dirac particles interact via a classical gravitational and electromagnetic field. The Einstein-Dirac-Maxwell equations for this system are derived. It is shown that, under weak regularity conditions on the form of the horizon, the only black hole solutions of the EDM equations are the Reissner-Nordstrom solutions. In other words, the spinors must vanish identically. Applied to the gravitational collapse of a "cloud" of spin-1/2-particles to a black hole, our result indicates that the Dirac particles must eventually disappear inside the event horizon.

An Investigation of EME as a Potential Cause of Fuel Tank Ignition

NASA Technical Reports Server (NTRS)

Ely, Jay J.; Nguyen, Truong X.; Dudley, Kenneth L.; Scearce, Stephen A.; Beck, Fred B.; Deshpande, Manohar D.; Cockrell, C. R.

2000-01-01

NASA researchers were tasked to study the potential for radio signals to excite an aircraft fuel quantity indication system (FQIS) enough to cause arcing, sparking or excessive heating within a fuel tank. Computational techniques were used to determine the threat from external high intensity radiated field (HIRF) transmitters nearby, like shipboard and airborne RADAR systems. Experimental methods were used to determine the threat from Portable Electronic Devices (PEDs) carried aboard by passengers. To support this work, unique electromagnetic coupling measurements were performed on a retired Boeing 747 aircraft, and new test and analysis methods were developed that may be applied to other FQIS designs as well as other aircraft electronic systems.

Spiral-like multi-beam emission via transformation electromagnetics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tichit, Paul-Henri, E-mail: paul-henri.tichit@u-psud.fr; Burokur, Shah Nawaz, E-mail: shah-nawaz.burokur@u-psud.fr; Lustrac, André de, E-mail: andre.de-lustrac@u-psud.fr

Transformation electromagnetics offers an unconventional approach for the design of novel radiating devices. Here, we propose an electromagnetic metamaterial able to split an isotropic radiation into multiple directive beams. By applying transformations that modify distance and angles, we show how the multiple directive beams can be steered at will. We describe transformation of the metric space and the calculation of the material parameters. Different transformations are proposed for a possible physical realization through the use of engineered artificial metamaterials. Full wave simulations are performed to validate the proposed approach. The idea paves the way to interesting applications in various domainsmore » in microwave and optical regimes.« less

Electromagnetic processes in nucleus-nucleus collisions relating to space radiation research

NASA Technical Reports Server (NTRS)

Norbury, John W.

1992-01-01

Most of the papers within this report deal with electromagnetic processes in nucleus-nucleus collisions which are of concern in the space radiation program. In particular, the removal of one and two nucleons via both electromagnetic and strong interaction processes has been extensively investigated. The theory of relativistic Coulomb fission has also been developed. Several papers on quark models also appear. Finally, note that the theoretical methods developed in this work have been directly applied to the task of radiation protection of astronauts. This has been done by parameterizing the theoretical formalism in such a fashion that it can be used in cosmic ray transport codes.

Stability of stationary-axisymmetric black holes in vacuum general relativity to axisymmetric electromagnetic perturbations

NASA Astrophysics Data System (ADS)

Prabhu, Kartik; Wald, Robert M.

2018-01-01

We consider arbitrary stationary and axisymmetric black holes in general relativity in (d +1) dimensions (with d ≥slant 3 ) that satisfy the vacuum Einstein equation and have a non-degenerate horizon. We prove that the canonical energy of axisymmetric electromagnetic perturbations is positive definite. This establishes that all vacuum black holes are stable to axisymmetric electromagnetic perturbations. Our results also hold for asymptotically de Sitter black holes that satisfy the vacuum Einstein equation with a positive cosmological constant. Our results also apply to extremal black holes provided that the initial perturbation vanishes in a neighborhood of the horizon.

Transcranial stimulability of phosphenes by long lightning electromagnetic pulses

NASA Astrophysics Data System (ADS)

Peer, J.; Kendl, A.

2010-06-01

The electromagnetic pulses of rare long (order of seconds) repetitive lightning discharges near strike point (order of 100 m) are analyzed and compared to magnetic fields applied in standard clinical transcranial magnetic stimulation (TMS) practice. It is shown that the time-varying lightning magnetic fields and locally induced electric fields are in the same order of magnitude and frequency as those established in TMS experiments to study stimulated perception phenomena, like magnetophosphenes. Lightning electromagnetic pulse induced transcranial magnetic stimulation of phosphenes in the visual cortex is concluded to be a plausible interpretation of a large class of reports on luminous perceptions during thunderstorms.

Nonlinear electromagnetic interactions in energetic materials

DOE PAGES

Wood, Mitchell Anthony; Dalvit, Diego Alejandro; Moore, David Steven

2016-01-12

We study the scattering of electromagnetic waves in anisotropic energetic materials. Nonlinear light-matter interactions in molecular crystals result in frequency-conversion and polarization changes. Applied electromagnetic fields of moderate intensity can induce these nonlinear effects without triggering chemical decomposition, offering a mechanism for the nonionizing identification of explosives. We use molecular-dynamics simulations to compute such two-dimensional THz spectra for planar slabs made of pentaerythritol tetranitrate and ammonium nitrate. Finally, we discuss third-harmonic generation and polarization-conversion processes in such materials. These observed far-field spectral features of the reflected or transmitted light may serve as an alternative tool for standoff explosive detection.

Quality assurance for clinical implementation of an electromagnetic tracking system.

PubMed

Santanam, Lakshmi; Noel, Camille; Willoughby, Twyla R; Esthappan, Jacqueline; Mutic, Sasa; Klein, Eric E; Low, Daniel A; Parikh, Parag J

2009-08-01

The Calypso Medical 4D localization system utilizes alternating current electromagnetics for accurate, real-time tumor tracking. A quality assurance program to clinically implement this system is described here. Testing of the continuous electromagnetic tracking system (Calypso Medical Technologies, Seattle, WA) was performed using an in-house developed four-dimensional stage and a quality assurance fixture containing three radiofrequency transponders at independently measured locations. The following tests were performed to validate the Calypso system: (a) Localization and tracking accuracy, (b) system reproducibility, (c) measurement of the latency of the tracking system, and (d) measurement of transmission through the Calypso table overlay and the electromagnetic array. The translational and rotational localization accuracies were found to be within 0.01 cm and 1.0 degree, respectively. The reproducibility was within 0.1 cm. The average system latency was measured to be within 303 ms. The attenuation by the Calypso overlay was measured to be 1.0% for both 6 and 18 MV photons. The attenuations by the Calypso array were measured to be 2% and 1.5% for 6 and 18 MV photons, respectively. For oblique angles, the transmission was measured to be 3% for 6 MV, while it was 2% for 18 MV photons. A quality assurance process has been developed for the clinical implementation of an electromagnetic tracking system in radiation therapy.

The Teaching of Electromagnetism at University Level

ERIC Educational Resources Information Center

Houldin, J. E.

1974-01-01

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

Differential form representation of stochastic electromagnetic fields

NASA Astrophysics Data System (ADS)

Haider, Michael; Russer, Johannes A.

2017-09-01

In this work, we revisit the theory of stochastic electromagnetic fields using exterior differential forms. We present a short overview as well as a brief introduction to the application of differential forms in electromagnetic theory. Within the framework of exterior calculus we derive equations for the second order moments, describing stochastic electromagnetic fields. Since the resulting objects are continuous quantities in space, a discretization scheme based on the Method of Moments (MoM) is introduced for numerical treatment. The MoM is applied in such a way, that the notation of exterior calculus is maintained while we still arrive at the same set of algebraic equations as obtained for the case of formulating the theory using the traditional notation of vector calculus. We conclude with an analytic calculation of the radiated electric field of two Hertzian dipole, excited by uncorrelated random currents.

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

PubMed Central

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

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

PubMed

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.

Interaction of Electromagnetic Fields with Chondrocytes in Gel Culture

DTIC Science & Technology

1990-02-01

biosynthesis due to applied electromagnetic fields. The results suggest that both normal chondrocytes and swarm rat chondrosarcoma cells in agarose Culture...and Swarm rat chondrosarcoma cells in agarose iii culture can, under proper culture conditions, continue to synthesize ma- trix macromolecules at a...cartilagc, and in rat chondrosarcoma cells (a continuous cell line). The overt gene expression of chondrocytes results in the synthesis and deposition of a

Dipole Models for UXO Discrimination at Live Sites

DTIC Science & Technology

2017-05-01

Discriminator CCR Combined Classifier Ranking cm Centimeter(s) EM Electromagnetic EMI Electromagnetic Induction ESTCP Environmental Security Technology...fraction of the anomalies as arising from non-hazardous items that could be safely left in the ground. Of particular note, the contractor EM -61-MK2 cart...use of classification metrics applied to production quality EM - 61 data, it was possible to significantly reduce the number of clutter items excavated

Microwave Remote Sensing of Falling Snow

NASA Technical Reports Server (NTRS)

Kim, Min-Jeong; Wang, J. R.; Meneghini, R.; Johnson, B.; Tanelli, S.; Roman-Nieves, J. I.; Sekelsky, S. M.; Skofronick-Jackson, G.

2005-01-01

This study analyzes passive and active microwave measurements during the 2003 Wakasa Bay field experiment for understanding of the electromagnetic characteristics of frozen hydrometeors at millimeter-wave frequencies. Based on these understandings, parameterizations of the electromagnetic scattering properties of snow at millimeter-wave frequencies are developed and applied to the hydrometeor profiles obtained by airborne radar measurements. Calculated brightness temperatures and radar reflectivity are compared with the millimeter-wave measurements.

Excitation of Surface Electromagnetic Waves on Railroad Rail

DOT National Transportation Integrated Search

1978-03-31

UMTA's Office of Rail Technology research programs aim to improve urban rail transportation systems safety. This rail-transit research study attempts to develop an onboard, separate and independent obstacle-detection system--Surface Electromagnetic W...

Design and analysis of an MR rotary brake for self-regulating braking torques.

PubMed

Yun, Dongwon; Koo, Jeong-Hoi

2017-05-01

This paper presents a novel Magneto-rheological (MR) brake system that can self-regulate the output braking torques. The proposed MR brake can generate a braking torque at a critical rotation speed without an external power source, sensors, or controllers, making it a simple and cost-effective device. The brake system consists of a rotary disk, permanent magnets, springs, and MR fluid. The permanent magnets are attached to the rotary disk via the springs, and they move outward through grooves with two different gap distances along the radial direction of the stator due to the centrifugal force. Thus, the position of the magnets is dependent on the spin speed, and it can determine the magnetic fields applied to MR fluids. Proper design of the stator geometry gives the system unique torque characteristics. To show the performance of an MR brake system, the electromagnetic characteristics of the system are analyzed, and the torques generated by the brake are calculated using the result of the electromagnetic analysis. Using a baseline model, a parametric study is conducted to investigate how the design parameters (geometric shapes and material selection) affect the performance of the brake system. After the simulation study, a prototype brake system is constructed and its performance is experimentally evaluated. The experimental results show that the prototype produced the maximum torque of 1.2 N m at the rotational speed of 100 rpm. The results demonstrate the feasibility of the proposed MR brake as a speed regulator in rotating systems.

Department of Defense Interface Standard Electromagnetic Environmental Effects Requirements for Systems

DTIC Science & Technology

2002-12-19

effective tool in evaluating IMI. A5.2.2 Shipboard internal electromagnetic environment (EME). For ship applications, electric fields (peak V/m-rms...effects waveform parameters ........................................ 9 MIL-STD-464A v CONTENTS Page TABLES 2B Electromagnetic fields from near...blasting of hardware. 3.8 Lightning indirect effects. Electrical transients induced by lightning due to coupling of electromagnetic fields . 3.9

Evaluation of Honeywell Recoverable Computer System (RCS) in Presence of Electromagnetic Effects

NASA Technical Reports Server (NTRS)

Malekpour, Mahyar

1997-01-01

The design and development of a Closed-Loop System to study and evaluate the performance of the Honeywell Recoverable Computer System (RCS) in electromagnetic environments (EME) is presented. The development of a Windows-based software package to handle the time critical communication of data and commands between the RCS and flight simulation code in real-time, while meeting the stringent hard deadlines is also presented. The performance results of the RCS while exercising flight control laws under ideal conditions as well as in the presence of electromagnetic fields is also discussed.

Use of pupil size to determine the effect of electromagnetic acupuncture on activation level of the autonomic nervous system.

PubMed

Kim, Soo-Byeong; Choi, Woo-Hyuk; Liu, Wen-Xue; Lee, Na-Ra; Shin, Tae-Min; Lee, Yong-Heum

2014-06-01

Magnetic fields are widely considered as a method of treatment to increase the therapeutic effect when applied to acupoints. Hence, this study proposes a new method which creates significant stimulation of acupoints by using weak magnetic fields. We conducted this experiment in order to confirm the effect on the activation level of the autonomic nervous system by measuring pupil sizes in cases of stimulation by using manual acupuncture and electromagnetic acupuncture (EMA) at BL15. We selected 30 Hz of biphasic wave form with 570.1 Gauss. To confirm the biopotential by the magnetic flux density occurring in EMA that affected the activation of the autonomic nervous system, we observed the biopotential induced at the upper and the mid left and right trapezius. We observed a significant decrease in pupil size only in the EMA group (p < 0.05), thus confirming that EMA decreased the pupil size through activation of the parasympathetic nerve in the autonomic nervous system. Moreover, we confirmed that the amplitude of the biopotential which was caused by 570.1 Gauss was higher than ±20 μA. Thus, we can conclude that EMA treatment successfully activates the parasympathetic nerve in the autonomic nervous system by inducing a biotransformation by the induced biopotential. Copyright © 2014. Published by Elsevier B.V.

A new array system for multiphysics (MT, LOTEM, and microseismics) with focus on reservoir monitoring

NASA Astrophysics Data System (ADS)

Strack, K.; Davydycheva, S.; Hanstein, T.; Smirnov, M.

2017-07-01

Over the last 6 years we developed an array system for electromagnetic acquisition (magnetotelluric & long offset transient electromagnetics [LOTEM]) that includes microseismic acquisition. While predominantly used for magnetotellurics, we focus on the autonomous operation as reservoir monitoring system including a shallow borehole receiver and 100/150 KVA transmitter. A marine extension is also under development. For Enhanced Oil recovery (EOR), in addition to reservoir flood front movements, reservoir seal integrity has become an issue [1]. Seal integrity is best addressed with microseismics while the water flood front is best addressed with electromagnetics. Since the flooded reservoir is conductive and the hydrocarbon saturated part is resistive, you need both magnetic and electric fields. The fluid imaging is addressed using electromagnetics. To overcome the volume-focus inherent to electromagnetics a new methodology to focus the sensitivity under the receiver is proposed. Field data and 3D modeling confirm this could increase the efficiency of LOTEM to reservoir monitoring.

Scattering from fractals

NASA Astrophysics Data System (ADS)

Hurd, Alan J.

The realization that structures in Nature often can be described by Mandelbrot's fractals has led to a revolution in many areas of physics. The interaction of waves with fractal systems has, understandably, become intensely studied since scattering is the method of choice to probe delicate fractal structures such as chainlike particle aggregates. Not all of these waves are electromagnetic. Neutron scattering, for example, is an important complementary tool to structural studies by X-ray and light scattering. Since the phenomenology of small-angle neutron scattering (SANS), as it is applied to fractal systems, is identical to that of small-angle X-ray scattering (SAXS), it falls within the scope of this paper.

Terrain modeling for microwave landing system

NASA Technical Reports Server (NTRS)

Poulose, M. M.

1991-01-01

A powerful analytical approach for evaluating the terrain effects on a microwave landing system (MLS) is presented. The approach combines a multiplate model with a powerful and exhaustive ray tracing technique and an accurate formulation for estimating the electromagnetic fields due to the antenna array in the presence of terrain. Both uniform theory of diffraction (UTD) and impedance UTD techniques have been employed to evaluate these fields. Innovative techniques are introduced at each stage to make the model versatile to handle most general terrain contours and also to reduce the computational requirement to a minimum. The model is applied to several terrain geometries, and the results are discussed.

Numerical Simulation of Partially-Coherent Broadband Optical Imaging Using the FDTD Method

PubMed Central

Çapoğlu, İlker R.; White, Craig A.; Rogers, Jeremy D.; Subramanian, Hariharan; Taflove, Allen; Backman, Vadim

2012-01-01

Rigorous numerical modeling of optical systems has attracted interest in diverse research areas ranging from biophotonics to photolithography. We report the full-vector electromagnetic numerical simulation of a broadband optical imaging system with partially-coherent and unpolarized illumination. The scattering of light from the sample is calculated using the finite-difference time-domain (FDTD) numerical method. Geometrical optics principles are applied to the scattered light to obtain the intensity distribution at the image plane. Multilayered object spaces are also supported by our algorithm. For the first time, numerical FDTD calculations are directly compared to and shown to agree well with broadband experimental microscopy results. PMID:21540939

[pi][sup 0] electromagnetic self-energy and its implications for incorporating electromagnetism in few-body systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maltman, K.

1994-08-01

By investigating the electromagnetic (EM) chiral series for the pseudoscalar mesons at next-to-leading order, it is shown that the [pi][sup 0] EM self-energy is [ital O]([alpha][sub EM][ital m][sub [ital u],][ital d]), and hence small. This observation completes the crucial step in an earlier argument, which employed previously the vanishing of the [pi][sup 0] EM self-energy in the chiral limit, and which demonstrates that the effects of not only one-photon-exchange- but also one-photon-loop graphs must be included in order to incorporate the effects of electromagnetism in hadronic systems.

[Effects of extremely low frequency electromagnetic radiation on cardiovascular system of workers].

PubMed

Zhao, Long-yu; Song, Chun-xiao; Yu, Duo; Liu, Xiao-liang; Guo, Jian-qiu; Wang, Chuan; Ding, Yuan-wei; Zhou, Hong-xia; Ma, Shu-mei; Liu, Xiao-dong; Liu, Xin

2012-03-01

To observe the exposure levels of extremely low frequency electromagnetic fields in workplaces and to analyze the effects of extremely low frequency electromagnetic radiation on cardiovascular system of occupationally exposed people. Intensity of electromagnetic fields in two workplaces (control and exposure groups) was detected with EFA-300 frequency electromagnetic field strength tester, and intensity of the noise was detected with AWA5610D integral sound level. The information of health physical indicators of 188 controls and 642 occupationally exposed workers was collected. Data were analyzed by SPSS17.0 statistic software. The intensity of electric fields and the magnetic fields in exposure groups was significantly higher than that in control group (P < 0.05), but there was no significant difference of noise between two workplaces (P > 0.05). The results of physical examination showed that the abnormal rates of HCY, ALT, AST, GGT, ECG in the exposure group were significantly higher than those in control group (P < 0.05). There were no differences of sex, age, height, weight between two groups (P > 0.05). Exposure to extremely low frequency electromagnetic radiation may have some effects on the cardiovascular system of workers.

Automatic box loader

DOEpatents

Eldridge, Harry H.; Jones, Robert A.; Lindner, Gordon M.; Hight, Paul H.

1976-01-01

This invention relates to a system for repetitively forming an assembly consisting of a single layer of tubes and a row of ferromagnetic armatures underlying the same, electromagnetically conveying the resulting assembly to a position overlying a storage box, and depositing the assembly in the box. The system includes means for simultaneously depositing a row of the armatures on the inclined surface of a tube retainer. Tubes then are rolled down the surface to form a single tube layer bridging the armatures. A magnet assembly carrying electromagnets respectively aligned with the armatures is advanced close to the tube layer, and in the course of this advance is angularly displaced to bring the pole pieces of the electromagnets into parallelism with the tube layer. The magnets then are energized to pick up the assembly. The loaded magnet assembly is retracted to a position overlying the box, and during this retraction is again displaced to bring the pole pieces of the electromagnets into a horizontal plane. Means are provided for inserting the loaded electromagnets in the box and then de-energizing the electromagnets to deposit the assembly therein. The system accomplishes the boxing of fragile tubes at relatively high rates. Because the tubes are boxed as separated uniform layers, subsequent unloading operations are facilitated.

IMMUNOLOGICAL AND HEMATOLOGICAL EFFECTS OF MICROWAVE POWER TRANSMISSION FROM A SATELLITE POWER SYSTEM (PART 1 AND PART 2)

EPA Science Inventory

Two systems for exposing mice to 2450 MHz electromagnetic fields are described. The first system was used to expose mice dorsally to circularly polarized electromagnetic fields. The second system was a minature anechoic chamber modified from the original design. Mice were exposed...

Optimal power, power limit, and damping of vibration piezoelectric power harvesters

NASA Astrophysics Data System (ADS)

Liao, Yabin; Sodano, Henry

2018-03-01

Power harvesting describes the process of acquiring the ambient energy surrounding a system and converting it into usable electrical energy. Much of the work over the past two decades has focused on the conversion of ambient vibration energy sources using piezoelectric, electromagnetic and electrostatic transduction. Attempts were made to obtain a general model that could be applied to any transduction mechanism. Of the most interest is an electromagnetic generator model that was used by many researchers to model piezoelectric power harvesters. Two major results from the model are the power limit expression and the equal relationship between the electrically induced damping and the mechanical damping to reach the power limit. However, piezoelectric power harvesters cannot be accurately modeled by this electromagnetic model due to the essential difference in physics. There have also been attempts to obtain the power limit expression based on piezoelectric relationships, but they either neglect the piezoelectric backward coupling to the structure, or assume the power limit occurs at the resonance of the system. This paper obtains the power limit expression based on the piezoelectric coupled equations without those assumptions. In addition, the relationship between the electrically induced damping and mechanical damping at the power limit is studied. Furthermore, a closed-form criterion is derived and proposed to define strongly and weakly coupling power harvesters, whose differences in power characteristics are explained through analytical and numerical analysis. While most of the discussion is focused on linear power harvesters connected to a resistive circuit, the aim of this paper is to provide a comprehensive and deep understanding of this simple configuration, answers to important questions, and a starting point to develop a more general theory on power harvesters because similar system characteristics are observed in power harvesters with more complexities.

Study to assess the effects of magnetohydrodynamic electromagnetic pulse on electric power systems, phase 1, volume 3

NASA Astrophysics Data System (ADS)

Legro, J. R.; Abi-Samra, N. C.; Tesche, F. M.

1985-05-01

In addition to the initial transients designated as fast transient high-altitude EMP (HEMP) and intermediate time EMP, electromagnetic signals are also perceived at times from seconds to hundreds of seconds after a high-altitude nuclear burst. This signal was defined by the term magnetohydrodynamic-electromagnetic pulse (MHD-EMP). The MHD-EMP phenomena was detected in actual weapon tests and predicted from theoretical models. A preliminary research effort to investigate the nature and coupling of the MHD-EMP environments to electric power systems documented the construction of approximate system response network models, and the development of a unified methodology to assess equipment and systematic vulnerability are defined. The MHD-EMP environment is compared to a qualitatively similar natural event, the electromagnetic environment produced by geomagnetic storms.

Performance of cardiopulmonary resuscitation feedback systems in a long-distance train with distributed traction.

PubMed

González-Otero, Digna M; de Gauna, Sofía Ruiz; Ruiz, Jesus; Rivero, Raquel; Gutierrez, J J; Saiz, Purificación; Russell, James K

2018-04-20

Out-of-hospital cardiac arrest is common in public locations, including public transportation sites. Feedback devices are increasingly being used to improve chest-compression quality. However, their performance during public transportation has not been studied yet. To test two CPR feedback devices representative of the current technologies (accelerometer and electromag- netic-field) in a long-distance train. Volunteers applied compressions on a manikin during the train route using both feedback devices. Depth and rate measurements computed by the devices were compared to the gold-standard values. Sixty-four 4-min records were acquired. The accelerometer-based device provided visual help in all experiments. Median absolute errors in depth and rate were 2.4 mm and 1.3 compressions per minute (cpm) during conventional speed, and 2.5 mm and 1.2 cpm during high speed. The electromagnetic-field-based device never provided CPR feedback; alert messages were shown instead. However, measurements were stored in its internal memory. Absolute errors for depth and rate were 2.6 mm and 0.7 cpm during conventional speed, and 2.6 mm and 0.7 cpm during high speed. Both devices were accurate despite the accelerations and the electromagnetic interferences induced by the train. However, the electromagnetic-field-based device would require modifications to avoid excessive alerts impeding feedback.

A hybrid Boundary Element Unstructured Transmission-line (BEUT) method for accurate 2D electromagnetic simulation

NASA Astrophysics Data System (ADS)

Simmons, Daniel; Cools, Kristof; Sewell, Phillip

2016-11-01

Time domain electromagnetic simulation tools have the ability to model transient, wide-band applications, and non-linear problems. The Boundary Element Method (BEM) and the Transmission Line Modeling (TLM) method are both well established numerical techniques for simulating time-varying electromagnetic fields. The former surface based method can accurately describe outwardly radiating fields from piecewise uniform objects and efficiently deals with large domains filled with homogeneous media. The latter volume based method can describe inhomogeneous and non-linear media and has been proven to be unconditionally stable. Furthermore, the Unstructured TLM (UTLM) enables modelling of geometrically complex objects by using triangular meshes which removes staircasing and unnecessary extensions of the simulation domain. The hybridization of BEM and UTLM which is described in this paper is named the Boundary Element Unstructured Transmission-line (BEUT) method. It incorporates the advantages of both methods. The theory and derivation of the 2D BEUT method is described in this paper, along with any relevant implementation details. The method is corroborated by studying its correctness and efficiency compared to the traditional UTLM method when applied to complex problems such as the transmission through a system of Luneburg lenses and the modelling of antenna radomes for use in wireless communications.

Single & Multiprobe Apertureless Thermal Imaging of Electromagnetic Excitation Over A Wide Range of Wavelengths

NASA Astrophysics Data System (ADS)

Dekhter, Rimma; Lewis, Aaron; Kokotov, Sophia; Hamra, Patricia; Fleischman, Boaz; Taha, Hesham

2013-03-01

Near-field optical effects have generally been detected using photodetectors. There are no reports on the use of the temperature changes caused by electromagnetic radiation using thermal sensing probes for scanned probe microscopy. In this paper we apply our development of such probes to monitor the effects of electromagnetic radiation at a number of different wavelengths using the heating caused in a sample by specific wavelengths and their propagation. The paper will catalogue effects over a wide spectrum of wavelengths from the near to mid infrared. The thermal sensing probes are based on glass nanopipettes that have metal wires that make a contact at the very tip of a tapered glass structure. These probes are cantilevered and use normal force tuning fork methodology to bring them either into contact or near-contact since this feedback method has no jump to contact instability associated with it. Data will be shown that defines the resolution of such thermal sensing to at least the 32 nm level. In addition the probes have the important attribute of having a highly exposed tip that allows for either optical sensing methodologies with a lens either from directly above or below or heat sensing with a single or additional probe in a multiprobe scanning probe system.

Coupling of electromagnetics and structural/fluid dynamics - application to the dual coolant blanket subjected to plasma disruptions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jordan, T.

Some aspects concerning the coupling of quasi-stationary electromagnetics and the dynamics of structure and fluid are investigated. The necessary equations are given in a dimensionless form. The dimensionless parameters in these equations are used to evaluate the importance of the different coupling effects. A finite element formulation of the eddy-current damping in solid structures is developed. With this formulation, an existing finite element method (FEM) structural dynamics code is extended and coupled to an FEM eddy-current code. With this program system, the influence of the eddy-current damping on the dynamic loading of the dual coolant blanket during a centered plasmamore » disruption is determined. The analysis proves that only in loosely fixed or soft structures will eddy-current damping considerably reduce the resulting stresses. Additionally, the dynamic behavior of the liquid metal in the blankets` poloidal channels is described with a simple two-dimensional magnetohydrodynamic approach. The analysis of the dimensionless parameters shows that for small-scale experiments, which are designed to model the coupled electromagnetic and structural/fluid dynamic effects in such a blanket, the same magnetic fields must be applied as in the real fusion device. This will be the easiest way to design experiments that produce transferable results. 10 refs., 7 figs.« less

A hybrid Boundary Element Unstructured Transmission-line (BEUT) method for accurate 2D electromagnetic simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simmons, Daniel, E-mail: daniel.simmons@nottingham.ac.uk; Cools, Kristof; Sewell, Phillip

Time domain electromagnetic simulation tools have the ability to model transient, wide-band applications, and non-linear problems. The Boundary Element Method (BEM) and the Transmission Line Modeling (TLM) method are both well established numerical techniques for simulating time-varying electromagnetic fields. The former surface based method can accurately describe outwardly radiating fields from piecewise uniform objects and efficiently deals with large domains filled with homogeneous media. The latter volume based method can describe inhomogeneous and non-linear media and has been proven to be unconditionally stable. Furthermore, the Unstructured TLM (UTLM) enables modelling of geometrically complex objects by using triangular meshes which removesmore » staircasing and unnecessary extensions of the simulation domain. The hybridization of BEM and UTLM which is described in this paper is named the Boundary Element Unstructured Transmission-line (BEUT) method. It incorporates the advantages of both methods. The theory and derivation of the 2D BEUT method is described in this paper, along with any relevant implementation details. The method is corroborated by studying its correctness and efficiency compared to the traditional UTLM method when applied to complex problems such as the transmission through a system of Luneburg lenses and the modelling of antenna radomes for use in wireless communications. - Graphical abstract:.« less

Coupling of electromagnetic and structural dynamics for a wind turbine generator

NASA Astrophysics Data System (ADS)

Matzke, D.; Rick, S.; Hollas, S.; Schelenz, R.; Jacobs, G.; Hameyer, K.

2016-09-01

This contribution presents a model interface of a wind turbine generator to represent the reciprocal effects between the mechanical and the electromagnetic system. Therefore, a multi-body-simulation (MBS) model in Simpack is set up and coupled with a quasi-static electromagnetic (EM) model of the generator in Matlab/Simulink via co-simulation. Due to lack of data regarding the structural properties of the generator the modal properties of the MBS model are fitted with respect to results of an experimental modal analysis (EMA) on the reference generator. The used method and the results of this approach are presented in this paper. The MB S model and the interface are set up in such a way that the EM forces can be applied to the structure and the response of the structure can be fed back to the EM model. The results of this cosimulation clearly show an influence of the feedback of the mechanical response which is mainly damping in the torsional degree of freedom and effects due to eccentricity in radial direction. The accuracy of these results will be validated via test bench measurements and presented in future work. Furthermore it is suggested that the EM model should be adjusted in future works so that transient effects are represented.

Inductive Interference in Rapid Transit Signaling Systems. Volume 3. Data and Test Results.

DOT National Transportation Integrated Search

1986-11-01

This report presents comparative inductive interference data obtained from four U.S. rapid transit systems employing chopper propulsion control, as part of the Rail Transit Electromagnetic Interference/Electromagnetic Compatibility program conducted ...

Metamaterial Absorber for Electromagnetic Waves in Periodic Water Droplets

PubMed Central

Yoo, Young Joon; Ju, Sanghyun; Park, Sang Yoon; Ju Kim, Young; Bong, Jihye; Lim, Taekyung; Kim, Ki Won; Rhee, Joo Yull; Lee, YoungPak

2015-01-01

Perfect metamaterial absorber (PMA) can intercept electromagnetic wave harmful for body in Wi-Fi, cell phones and home appliances that we are daily using and provide stealth function that military fighter, tank and warship can avoid radar detection. We reported new concept of water droplet-based PMA absorbing perfectly electromagnetic wave with water, an eco-friendly material which is very plentiful on the earth. If arranging water droplets with particular height and diameter on material surface through the wettability of material surface, meta-properties absorbing electromagnetic wave perfectly in GHz wide-band were shown. It was possible to control absorption ratio and absorption wavelength band of electromagnetic wave according to the shape of water droplet–height and diameter– and apply to various flexible and/or transparent substrates such as plastic, glass and paper. In addition, this research examined how electromagnetic wave can be well absorbed in water droplets with low electrical conductivity unlike metal-based metamaterials inquiring highly electrical conductivity. Those results are judged to lead broad applications to variously civilian and military products in the future by providing perfect absorber of broadband in all products including transparent and bendable materials. PMID:26354891

Terahertz electromagnetic fields (0.106 THz) do not induce manifest genomic damage in vitro.

PubMed

Hintzsche, Henning; Jastrow, Christian; Kleine-Ostmann, Thomas; Kärst, Uwe; Schrader, Thorsten; Stopper, Helga

2012-01-01

Terahertz electromagnetic fields are non-ionizing electromagnetic fields in the frequency range from 0.1 to 10 THz. Potential applications of these electromagnetic fields include the whole body scanners, which currently apply millimeter waves just below the terahertz range, but future scanners will use higher frequencies in the terahertz range. These and other applications will bring along human exposure to these fields. Up to now, only a limited number of investigations on biological effects of terahertz electromagnetic fields have been performed. Therefore, research is strongly needed to enable reliable risk assessment.Cells were exposed for 2 h, 8 h, and 24 h with different power intensities ranging from 0.04 mW/cm(2) to 2 mW/cm(2), representing levels below, at, and above current safety limits. Genomic damage on the chromosomal level was measured as micronucleus formation. DNA strand breaks and alkali-labile sites were quantified with the comet assay. No DNA strand breaks or alkali-labile sites were observed as a consequence of exposure to terahertz electromagnetic fields in the comet assay. The fields did not cause chromosomal damage in the form of micronucleus induction.

Terahertz Electromagnetic Fields (0.106 THz) Do Not Induce Manifest Genomic Damage In Vitro

PubMed Central

Hintzsche, Henning; Jastrow, Christian; Kleine-Ostmann, Thomas; Kärst, Uwe; Schrader, Thorsten; Stopper, Helga

2012-01-01

Terahertz electromagnetic fields are non-ionizing electromagnetic fields in the frequency range from 0.1 to 10 THz. Potential applications of these electromagnetic fields include the whole body scanners, which currently apply millimeter waves just below the terahertz range, but future scanners will use higher frequencies in the terahertz range. These and other applications will bring along human exposure to these fields. Up to now, only a limited number of investigations on biological effects of terahertz electromagnetic fields have been performed. Therefore, research is strongly needed to enable reliable risk assessment. Cells were exposed for 2 h, 8 h, and 24 h with different power intensities ranging from 0.04 mW/cm2 to 2 mW/cm2, representing levels below, at, and above current safety limits. Genomic damage on the chromosomal level was measured as micronucleus formation. DNA strand breaks and alkali-labile sites were quantified with the comet assay. No DNA strand breaks or alkali-labile sites were observed as a consequence of exposure to terahertz electromagnetic fields in the comet assay. The fields did not cause chromosomal damage in the form of micronucleus induction. PMID:23029508

Metamaterial Absorber for Electromagnetic Waves in Periodic Water Droplets

NASA Astrophysics Data System (ADS)

Yoo, Young Joon; Ju, Sanghyun; Park, Sang Yoon; Ju Kim, Young; Bong, Jihye; Lim, Taekyung; Kim, Ki Won; Rhee, Joo Yull; Lee, Youngpak

2015-09-01

Perfect metamaterial absorber (PMA) can intercept electromagnetic wave harmful for body in Wi-Fi, cell phones and home appliances that we are daily using and provide stealth function that military fighter, tank and warship can avoid radar detection. We reported new concept of water droplet-based PMA absorbing perfectly electromagnetic wave with water, an eco-friendly material which is very plentiful on the earth. If arranging water droplets with particular height and diameter on material surface through the wettability of material surface, meta-properties absorbing electromagnetic wave perfectly in GHz wide-band were shown. It was possible to control absorption ratio and absorption wavelength band of electromagnetic wave according to the shape of water droplet-height and diameter- and apply to various flexible and/or transparent substrates such as plastic, glass and paper. In addition, this research examined how electromagnetic wave can be well absorbed in water droplets with low electrical conductivity unlike metal-based metamaterials inquiring highly electrical conductivity. Those results are judged to lead broad applications to variously civilian and military products in the future by providing perfect absorber of broadband in all products including transparent and bendable materials.

Metamaterial Absorber for Electromagnetic Waves in Periodic Water Droplets.

PubMed

Yoo, Young Joon; Ju, Sanghyun; Park, Sang Yoon; Ju Kim, Young; Bong, Jihye; Lim, Taekyung; Kim, Ki Won; Rhee, Joo Yull; Lee, YoungPak

2015-09-10

Perfect metamaterial absorber (PMA) can intercept electromagnetic wave harmful for body in Wi-Fi, cell phones and home appliances that we are daily using and provide stealth function that military fighter, tank and warship can avoid radar detection. We reported new concept of water droplet-based PMA absorbing perfectly electromagnetic wave with water, an eco-friendly material which is very plentiful on the earth. If arranging water droplets with particular height and diameter on material surface through the wettability of material surface, meta-properties absorbing electromagnetic wave perfectly in GHz wide-band were shown. It was possible to control absorption ratio and absorption wavelength band of electromagnetic wave according to the shape of water droplet-height and diameter- and apply to various flexible and/or transparent substrates such as plastic, glass and paper. In addition, this research examined how electromagnetic wave can be well absorbed in water droplets with low electrical conductivity unlike metal-based metamaterials inquiring highly electrical conductivity. Those results are judged to lead broad applications to variously civilian and military products in the future by providing perfect absorber of broadband in all products including transparent and bendable materials.

The measurement procedure in the SEMONT monitoring system.

PubMed

Djuric, Nikola; Kljajic, Dragan; Kasas-Lazetic, Karolina; Bajovic, Vera

2014-03-01

The measurement procedure of the open area in situ electric field strength is presented, acquiring the real field data for testing of the Serbian electromagnetic field monitoring network (SEMONT) and its Internet portal. The SEMONT monitoring system introduces an advanced approach of wireless sensor network utilization for the continuous supervision of overall and cumulative level of electromagnetic field over the observed area. The aim of the SEMONT system is to become a useful tool for the national and municipal agencies for the environmental protection, regarding the electromagnetic pollution monitoring and the exposure assessment of the general population. Considering the public concern on the potentially harmful effects of the long-term exposure to electromagnetic radiation, as well as the public transparency principle that is incorporated into the Serbian law on non-ionizing radiation protection, the SEMONT monitoring system is designed for the long-term continuous monitoring, presenting real-time measurement results, and corresponding exposure assessment over the public Internet network.

Electromagnetic Radiation Disturbed the Photosynthesis of Microcystis aeruginosa at the Proteomics Level.

PubMed

Tang, Chao; Yang, Chuanjun; Yu, Hui; Tian, Shen; Huang, Xiaomei; Wang, Weiyi; Cai, Peng

2018-01-11

Photosynthesis of Microcystis aeruginosa under Electromagnetic Radiation (1.8 GHz, 40 V/m) was studied by using the proteomics. A total of 30 differentially expressed proteins, including 15 up-regulated and 15 down-regulated proteins, were obtained in this study. The differentially expressed proteins were significantly enriched in the photosynthesis pathway, in which the protein expression levels of photosystems II cytochrome b559 α subunit, cytochrome C550, PsbY, and F-type ATP synthase (a, b) decreased. Our results indicated that electromagnetic radiation altered the photosynthesis-related protein expression levels, and aimed at the function of photosynthetic pigments, photosystems II potential activity, photosynthetic electron transport process, and photosynthetic phosphorylation process of M. aeruginosa. Based on the above evidence, that photoreaction system may be deduced as a target of electromagnetic radiation on the photosynthesis in cyanobacteria; the photoreaction system of cyanobacteria is a hypothetical "shared target effector" that responds to light and electromagnetic radiation; moreover, electromagnetic radiation does not act on the functional proteins themselves but their expression processes.

Synthetic electromagnetic knot in a three-dimensional skyrmion

PubMed Central

Lee, Wonjae; Gheorghe, Andrei H.; Tiurev, Konstantin; Ollikainen, Tuomas; Möttönen, Mikko; Hall, David S.

2018-01-01

Classical electromagnetism and quantum mechanics are both central to the modern understanding of the physical world and its ongoing technological development. Quantum simulations of electromagnetic forces have the potential to provide information about materials and systems that do not have conveniently solvable theoretical descriptions, such as those related to quantum Hall physics, or that have not been physically observed, such as magnetic monopoles. However, quantum simulations that simultaneously implement all of the principal features of classical electromagnetism have thus far proved elusive. We experimentally realize a simulation in which a charged quantum particle interacts with the knotted electromagnetic fields peculiar to a topological model of ball lightning. These phenomena are induced by precise spatiotemporal control of the spin field of an atomic Bose-Einstein condensate, simultaneously creating a Shankar skyrmion—a topological excitation that was theoretically predicted four decades ago but never before observed experimentally. Our results reveal the versatile capabilities of synthetic electromagnetism and provide the first experimental images of topological three-dimensional skyrmions in a quantum system. PMID:29511735

Control and monitoring method and system for electromagnetic forming process

DOEpatents

Kunerth, Dennis C.; Lassahn, Gordon D.

1990-01-01

A process, system, and improvement for a process for electromagnetic forming of a workpiece in which characteristics of the workpiece such as its geometry, electrical conductivity, quality, and magnetic permeability can be determined by monitoring the current and voltage in the workcoil. In an electromagnet forming process in which a power supply provides current to a workcoil and the electromagnetic field produced by the workcoil acts to form the workpiece, the dynamic interaction of the electromagnetic fields produced by the workcoil with the geometry, electrical conductivity, and magnetic permeability of the workpiece, provides information pertinent to the physical condition of the workpiece that is available for determination of quality and process control. This information can be obtained by deriving in real time the first several time derivatives of the current and voltage in the workcoil. In addition, the process can be extended by injecting test signals into the workcoil during the electromagnetic forming and monitoring the response to the test signals in the workcoil.

Electromagnetic tracking of motion in the proximity of computer generated graphical stimuli: a tutorial.

PubMed

Schnabel, Ulf H; Hegenloh, Michael; Müller, Hermann J; Zehetleitner, Michael

2013-09-01

Electromagnetic motion-tracking systems have the advantage of capturing the tempo-spatial kinematics of movements independently of the visibility of the sensors. However, they are limited in that they cannot be used in the proximity of electromagnetic field sources, such as computer monitors. This prevents exploiting the tracking potential of the sensor system together with that of computer-generated visual stimulation. Here we present a solution for presenting computer-generated visual stimulation that does not distort the electromagnetic field required for precise motion tracking, by means of a back projection medium. In one experiment, we verify that cathode ray tube monitors, as well as thin-film-transistor monitors, distort electro-magnetic sensor signals even at a distance of 18 cm. Our back projection medium, by contrast, leads to no distortion of the motion-tracking signals even when the sensor is touching the medium. This novel solution permits combining the advantages of electromagnetic motion tracking with computer-generated visual stimulation.

The application of contraction theory to an iterative formulation of electromagnetic scattering

NASA Technical Reports Server (NTRS)

Brand, J. C.; Kauffman, J. F.

1985-01-01

Contraction theory is applied to an iterative formulation of electromagnetic scattering from periodic structures and a computational method for insuring convergence is developed. A short history of spectral (or k-space) formulation is presented with an emphasis on application to periodic surfaces. To insure a convergent solution of the iterative equation, a process called the contraction corrector method is developed. Convergence properties of previously presented iterative solutions to one-dimensional problems are examined utilizing contraction theory and the general conditions for achieving a convergent solution are explored. The contraction corrector method is then applied to several scattering problems including an infinite grating of thin wires with the solution data compared to previous works.

Influence of electromagnetic field on soliton-mediated charge transport in biological systems.

PubMed

Brizhik, Larissa

2015-01-01

It is shown that electromagnetic fields affect dynamics of Davydov's solitons which provide charge transport processes in macromolecules during metabolism of the system. There is a resonant frequency of the field at which it can cause the transition of electrons from bound soliton states into delocalised states. Such decay of solitons reduces the effectiveness of charge transport, and, therefore, inhibits redox processes. Solitons radiate their own electromagnetic field of characteristic frequency determined by their average velocity. This self-radiated field leads to synchronization of soliton dynamics and charge transport processes, and is the source of the coherence in the system. Exposition of the system to the oscillating electromagnetic field of the frequency, which coincides with the eigen-frequency of solitons can enhance eigen-radiation of solitons, and, therefore, will enhance synchronization of charge transpor, stimulate the redox processes and increase coherence in the system. Electromagnetic oscillating field causes also ratchet phenomenon of solitons, i.e., drift of solitons in macromolecules in the presence of unbiased periodic field. Such additional drift enhances the charge transport processes. It is shown that temperature facilitates the ratchet drift. In particular, temperature fluctuations lead to the lowering of the critical value of the intensity and period of the field, above which the drift of solitons takes place. Moreover, there is a stochastic resonance in the soliton dynamics in external electromagnetic fields. This means, that there is some optimal temperature at which the drift of solitons is maximal.

Study on electromagnetic radiation and mechanical characteristics of coal during an SHPB test

NASA Astrophysics Data System (ADS)

Chengwu, Li; Qifei, Wang; Pingyang, Lyu

2016-06-01

Dynamic loads provided by a Split Hopkinson pressure bar are applied in the impact failure experiment on coal with an impact velocity of 4.174-17.652 m s-1. The mechanical property characteristics of coal and an electromagnetic radiation signal can be detected and measured during the experiment. The variation of coal stress, strain, incident energy, dissipated energy and other mechanical parameters are analyzed by the unidimensional stress wave theory. It suggests that with an increase of the impact velocity, the mechanical parameters and electromagnetic radiation increased significantly and the dissipated energy of the coal sample has a high discrete growing trend during the failure process of coal impact. Combined with the received energy of the electromagnetic radiation signal, the relationship between these mechanical parameters and electromagnetic radiation during the failure process of coal burst could be analyzed by the grey correlation model. The results show that the descending order of the gray correlation degree between the mechanical characteristics and electromagnetic radiation energy are impact velocity, maximum stress, the average stress, incident energy, the average strain, maximum strain, the average strain rate and dissipation energy. Due to the correlation degree, the impact velocity and incident energy are relatively large, and the main factor affecting the electromagnetic radiation energy of coal is the energy magnitude. While the relationship between extreme stress and the radiation energy change trend is closed, the stress state of coal has a greater impact on electromagnetic radiation than the strain and destruction which can deepen the research of the coal-rock dynamic disaster electromagnetic monitoring technique.

Electromagnetic radiation from beam-plasma instabilities

NASA Technical Reports Server (NTRS)

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

1982-01-01

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

Environmental Assessment for North Warning System (Alaska)

DTIC Science & Technology

1986-11-10

With Respect to Human Exposure to Radio Frequency Electromagnetic Fields , 300 kHz to 100 GHz, ANSI C95.1-1982, IEEE, New York. CH 2M Hill, 1981...Council on Radiation Protection and Measurements), 1986.Biological Effects and Exposure Criteria for Radiofrequency Electromagnetic Fields . NCRP Report...6 4.1.3.1 Radiofrequency Radiation ..................... 4-7 4.1.3.1.1 Electromagnetic Hazards.......... 4-7 4.1.3.1.2 Electromagnetic Interference

Design, manufacture and performance evaluation of HTS electromagnets for the hybrid magnetic levitation system

NASA Astrophysics Data System (ADS)

Chu, S. Y.; Hwang, Y. J.; Choi, S.; Na, J. B.; Kim, Y. J.; Chang, K. S.; Bae, D. K.; Lee, C. Y.; Ko, T. K.

2011-11-01

A high speed electromagnetic suspension (EMS) maglev has emerged as the solution to speed limit problem that conventional high-speed railroad has. In the EMS maglev, small levitation gap needs uniform guide-way which leads to increase the construction cost. The large levitation gap can reduce the construction cost. However it is hard for normal conducting electromagnet to produce larger magneto-motive force (MMF) for generating levitation force as increased levitation gap. This is because normal conductors have limited rating current to their specific volume. Therefore, the superconducting electromagnet can be one of the solutions for producing both large levitation gap and sufficient MMF. The superconducting electromagnets have incomparably high allowable current density than what normal conductors have. In this paper, the prototype of high temperature superconducting (HTS) electromagnets were designed and manufactured applicable to hybrid electromagnetic suspension system (H-EMS). The H-EMS consists of control coils for levitation control and superconducting coils for producing MMF for levitation. The required MMF for generating given levitation force was calculated by both equations of ideal U-core magnet and magnetic field analysis using the finite element method (FEM). The HTS electromagnets were designed as double pancakes with Bi-2223/Ag tapes. Experiments to confirm its operating performance were performed in liquid nitrogen (LN2).

Effects of chronic exposure to electromagnetic waves on the auditory system.

PubMed

Özgür, Abdulkadir; Tümkaya, Levent; Terzi, Suat; Kalkan, Yıldıray; Erdivanlı, Özlem Çelebi; Dursun, Engin

2015-08-01

The results support that chronic electromagnetic field exposure may cause damage by leading to neuronal degeneration of the auditory system. Numerous researches have been done about the risks of exposure to the electromagnetic fields that occur during the use of these devices, especially the effects on hearing. The aim of this study is to evaluate the effects of the electromagnetic waves emitted by the mobile phones through the electrophysiological and histological methods. Twelve adult Wistar albino rats were included in the study. The rats were divided into two groups of six rats. The study group was exposed to the electromagnetic waves over a period of 30 days. The control group was not given any exposure to the electromagnetic fields. After the completion of the electromagnetic wave application, the auditory brainstem responses of both groups were recorded under anesthesia. The degeneration of cochlear nuclei was graded by two different histologists, both of whom were blinded to group information. The histopathologic and immunohistochemical analysis showed neuronal degeneration signs, such as increased vacuolization in the cochlear nucleus, pyknotic cell appearance, and edema in the group exposed to the electromagnetic fields compared to the control group. The average latency of wave in the ABR was similar in both groups (p > 0.05).

Electromagnetic environment measurements of PRT systems at "TRANSPO 72" : volume V, TTI System

DOT National Transportation Integrated Search

1974-01-01

An X-Y plot is made of the radiated Electromagnetic signals and noise between 1KHz and 50KHz at each of the four Personalized Rapid Transit (PRT) sites at Dulles International Airport. The PRT systems were operated individually to establish the signa...

Electromagnetic environment measurements of PRT systems at "TRANSPO 72" : volume IV, Monocab System

DOT National Transportation Integrated Search

1974-01-01

An X-Y plot is made of the radiated Electromagnetic signals and noise between 1 KHz and 50KHz at each of the four Personalized Rapid Transit (PRT) sites at Dulles International Airport. The PRT systems were operated individually to establish the sign...

Electromagnetic environment measurements of PRT systems at "TRANSPO 72" : volume II, Dashaveyor System

DOT National Transportation Integrated Search

1974-01-01

An X-Y plot is made of the radiated electromagnetic signals and noise between 1 KHz and 50 KHz at each of the four Personalized Rapid Transit (PRT) sites at Dulles International Airport. The PRT systems were operated individually to establish the sig...

Electromagnetic environment measurements of PRT systems at "TRANSPO 72" : volume III, Ford System

DOT National Transportation Integrated Search

1974-01-01

An X-Y plot is made of the radiated electromagnetic signals and noise between 1 KHz and 50 KHz at each of the four Personalized Rapid Transit (PRT) sites at Dulles International Airport. The PRT systems were operated individually to establish the sig...

Electromagnetic compatibility test report for the tethered satellite data acquisition and control assembly

NASA Astrophysics Data System (ADS)

Hoskins, Douglas; Snead, Robert

1988-05-01

This report details the results of an electromagnetic compatibility test on the SCI Systems Data Acquisition and Control Assembly (DACA). This assembly is an electronic processor which controls the central communication link from the Tethered Satellite System (TSS) to the Space Transportation System Orbiter Space Shuttle.

Interaction of biological systems with static and ELF electric and magnetic fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, L.E.; Kelman, B.J.; Weigel, R.J.

1987-01-01

Although background levels of atmospheric electric and geomagnetic field levels are extremely low, over the past several decades, human beings and other life forms on this planet have been subjected to a dramatically changing electromagnetic milieu. An exponential increase in exposure to electromagnetic fields has occurred, largely because of such technological advances as the growth of electrical power generation and transmission systems, the increased use of wireless communications, and the use of radar. In addition, electromagnetic field generating devices have proliferated in industrial plants, office buildings, homes, public transportation systems, and elsewhere. Although significant increases have occurred in electromagnetic fieldmore » strenghths spanning all frequency ranges, this symposium addresses only the impact of these fields at static and extremely low frequencies (ELF), primarily 50 and 60 Hz. This volume contains the proceedings of the symposium entitled /open quotes/Interaction of biological systems with static and ELF electric and magnetic fields/close quotes/. The purpose of the symposium was to provide a forum for discussions of all aspects of research on the interaction of static and ELF electromagnetic fields with biological systems. These systems include simple biophysical models, cell and organ preparations, whole animals, and man. Dosimetry, exposure system design, and artifacts in ELF bioeffects research were also addressed, along with current investigations that examine fundamental mechanisms of interactions between the fields and biological processes. Papers are indexed separately.« less

Analyses of electromagnetic and piezoelectric systems for efficient vibration energy harvesting

NASA Astrophysics Data System (ADS)

Hadas, Z.; Smilek, J.; Rubes, O.

2017-05-01

The paper deals with analyses and evaluation of vibration energy harvesting systems which are based on electromagnetic and piezoelectric physical principles off electro-mechanical conversion. Energy harvesting systems are associated with wireless sensors and a monitoring of engineering objects. The most of engineering objects operate with unwanted mechanical vibrations. However, vibrations could provide an ambient source of energy which is converted into useful electricity. The use of electromagnetic and piezoelectric vibration energy harvesters is analyzed in this paper. Thee evaluated output power is used for a choice of the efficient system with respect to the character of vibrations and thee required power output.

Generation of Fine Scale Wind and Wave Climatologies

NASA Astrophysics Data System (ADS)

Vandenberghe, F. C.; Filipot, J.; Mouche, A.

2013-12-01

A tool to generate 'on demand' large databases of atmospheric parameters at high resolution has been developed for defense applications. The approach takes advantage of the zooming and relocation capabilities of the embedded domains that can be found in regional models like the community Weather Research and Forecast model (WRF). The WRF model is applied to dynamically downscale NNRP, CFSR and ERA40 global analyses and to generate long records, up to 30 years, of hourly gridded data over 200km2 domains at 3km grid increment. To insure accuracy, observational data from the NCAR ADP historical database are used in combination with the Four-Dimensional Data Assimilation (FDDA) techniques to constantly nudge the model analysis toward observations. The atmospheric model is coupled to secondary applications such as the NOAA's Wave Watch III model the Navy's APM Electromagnetic Propagation model, allowing the creation of high-resolution climatologies of surface winds, waves and electromagnetic propagation parameters. The system was applied at several coastal locations of the Mediterranean Sea where SAR wind and wave observations were available during the entire year of 2008. Statistical comparisons between the model output and SAR observations are presented. Issues related to the global input data, and the model drift, as well as the impact of the wind biases on wave simulations will be discussed.

General Navier–Stokes-like momentum and mass-energy equations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Monreal, Jorge, E-mail: jmonreal@mail.usf.edu

2015-03-15

A new system of general Navier–Stokes-like equations is proposed to model electromagnetic flow utilizing analogues of hydrodynamic conservation equations. Such equations are intended to provide a different perspective and, potentially, a better understanding of electromagnetic mass, energy and momentum behaviour. Under such a new framework additional insights into electromagnetism could be gained. To that end, we propose a system of momentum and mass-energy conservation equations coupled through both momentum density and velocity vectors.

MR 201104: Evaluation of Discrimination Technologies and Classification Results and MR 201157: Demonstration of MetalMapper Static Data Acquisition and Data Analysis

DTIC Science & Technology

2016-09-23

Acquisition and Data Analysis). EMI sensors, MetalMapper, man-portable Time-domain Electromagnetic Multi-sensor Towed Array Detection System (TEMTADS...California Department of Toxic Substances Control EM61 EM61-MK2 EMI electromagnetic induction ESTCP Environmental Security Technology Certification...SOP Standard Operating Procedure v TEMTADS Time-domain Electromagnetic Multi-sensor Towed Array Detection System man-portable 2x2 TOI target(s

77 FR 54848 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-06

... damage to the operation of other critical airplane systems due to electromagnetic coupling and large... strike to the tail strobe light, electromagnetic coupling and large transient voltages can be transmitted... electromagnetic coupling, since the tail strobe light is located in a flammable leakage zone, electrical current...

Advanced Composite Aircraft Electromagnetic Design and Synthesis

DTIC Science & Technology

1980-05-01

Naval Air Systems Command, July 1978. 9. J.L. Bogdanor , R.A. Pearlman, and M.D. Siegel, Intrasystem Electromagnetic Compatibility Analysis Program...F30602-72-C-0277, RADC-TR-74-342, December 1974. 11. J.L. Bogdanor , R.A. Pearlman, and M.D. Siegel, Intrasystem Electromagnetic Comptibility Analysis

Comparison of the Effects of Manual Acupuncture, Laser Acupuncture, and Electromagnetic Field Stimulation at Acupuncture Point BL15 on Heart Rate Variability.

PubMed

Lee, Na Ra; Kim, Soo Byeong; Heo, Hyun; Lee, Yong Heum

2016-10-01

The aim of this study was to compare the influences of manual acupuncture, laser acupuncture, and electromagnetic field stimulation on the autonomic nervous system. We monitored the heart rate variability before and after stimulation to check the influence on the autonomic nervous system. The heart rate variabilities at low frequency (LF; 0.04-0.15 Hz) and high frequency (HF; 0.15-0.4 Hz) were analyzed to acquire LF/HF ratio. Xinshu (BL15) was selected as the stimulation point. Methods included manual acupuncture with a 1-cm depth and laser acupuncture at a wavelength of 660 nm and output power of 50 mW. An electromagnetic field of 2 Hz and 460 gauss (46 mT) was chosen. The LF and the LF/HF ratio were found to be lower in the manual acupuncture and the electromagnetic field groups, but to be higher in the laser acupuncture group. The HF was found to be lower in the laser acupuncture group, but higher in the manual acupuncture and the electromagnetic field groups. In conclusion, we found that manual acupuncture and electromagnetic field stimulation at BL15 activated the parasympathetic nervous system, whereas laser acupuncture at BL15 activated the sympathetic nervous system. Copyright © 2016. Published by Elsevier B.V.

Avionics system design for high energy fields: A guide for the designer and airworthiness specialist

NASA Technical Reports Server (NTRS)

Mcconnell, Roger A.

1987-01-01

Because of the significant differences in transient susceptibility, the use of digital electronics in flight critical systems, and the reduced shielding effects of composite materials, there is a definite need to define pracitices which will minimize electromagnetic susceptibility, to investigate the operational environment, and to develop appropriate testing methods for flight critical systems. The design practices which will lead to reduced electromagnetic susceptibility of avionics systems in high energy fields is described. The levels of emission that can be anticipated from generic digital devices. It is assumed that as data processing equipment becomes an ever larger part of the avionics package, the construction methods of the data processing industry will increasingly carry over into aircraft. In Appendix 1 tentative revisions to RTCA DO-160B, Environmental Conditions and Test Procedures for Airborne Equipment, are presented. These revisions are intended to safeguard flight critical systems from the effects of high energy electromagnetic fields. A very extensive and useful bibliography on both electromagnetic compatibility and avionics issues is included.

A comparison of helicopter-borne electromagnetic systems for hydrogeologic studies

USGS Publications Warehouse

Bedrosian, Paul A.; Schamper, Cyril; Auken, Esben

2016-01-01

The increased application of airborne electromagnetic surveys to hydrogeological studies is driving a demand for data that can consistently be inverted for accurate subsurface resistivity structure from the near surface to depths of several hundred metres. We present an evaluation of three commercial airborne electromagnetic systems over two test blocks in western Nebraska, USA. The selected test blocks are representative of shallow and deep alluvial aquifer systems with low groundwater salinity and an electrically conductive base of aquifer. The aquifer units show significant lithologic heterogeneity and include both modern and ancient river systems. We compared the various data sets to one another and inverted resistivity models to borehole lithology and to ground geophysical models. We find distinct differences among the airborne electromagnetic systems as regards the spatial resolution of models, the depth of investigation, and the ability to recover near-surface resistivity variations. We further identify systematic biases in some data sets, which we attribute to incomplete or inexact calibration or compensation procedures.

Out of time: a possible link between mirror neurons, autism and electromagnetic radiation.

PubMed

Thornton, Ian M

2006-01-01

Recent evidence suggests a link between autism and the human mirror neuron system. In this paper, I argue that temporal disruption from the environment may play an important role in the observed mirror neuron dysfunction, leading in turn to the pattern of deficits associated with autism. I suggest that the developing nervous system of an infant may be particularly prone to temporal noise that can interfere with the initial calibration of brain networks such as the mirror neuron system. The most likely source of temporal noise in the environment is artificially generated electromagnetic radiation. To date, there has been little evidence that electromagnetic radiation poses a direct biological hazard. It is clear, however, that time-varying electromagnetic waves have the potential to temporally modulate the nervous system, particularly when populations of neurons are required to act together. This modulation may be completely harmless for the fully developed nervous system of an adult. For an infant, this same temporal disruption might act to severely delay or disrupt vital calibration processes.

[National system of protection against electromagnetic fields 0 Hz-300 GHz in the light of current legal regulations].

PubMed

Aniołczyk, Halina

2006-01-01

Exposure to electromagnetic fields (EMF) occurs when man is exposed to the effect of electric, magnetic and electromagnetic fields and contact currents different from those resulting from physiological processes in the organism or other natural phenomena. In Poland, the system of protection against EMF has been functioning for over 35 years. In 2001, when the Minister of Labor and Social Policy issued the regulation introducing the maximum admissible intensities (MAI) for electromagnetic fields and radiation within the range of 0 Hz-300 GHz, the system was directed mainly towards evaluation of exposure to EMF occurring in the occupational environment. The system is linked via MAI values with human protection in the natural environment. In this paper, the background, principles and the range of the national system of protection against EMF and its monitoring are presented. The project of implementation of EU directives, following Poland's accession to the European Union is also discussed.

Electromagnetic-field effects on structure and dynamics of amyloidogenic peptides

NASA Astrophysics Data System (ADS)

Todorova, Nevena; Bentvelzen, Alan; English, Niall J.; Yarovsky, Irene

2016-02-01

Electromagnetic fields (EMFs) are ever-present, and so is the need to better understand their influence on human health and biological matter in general. The interaction between a molecular system and external EMF can alter the structure, and dynamical behaviour, and, hence, biological function of proteins with uncertain health consequences. This urges a detailed investigation of EMF-induced effects on basic protein biophysics. Here, we used all-atom non-equilibrium molecular dynamics simulations to understand and quantify the response mechanisms of the amyloidogenic apoC-II(60-70) peptides to non-ionising radiation by modelling their behaviour under external electromagnetic and electric fields of different strengths. Our simulations show high strength fields (>0.04 V/nm) cause structural changes in apoC-II(60-70) due to the peptide dipole alignment along the applied field direction, which disrupts the inherent β-hairpin conformation known to be the intermediate state for fibril formation. The intermediate field-strength range (0.04-0.004 V/nm) causes a significant acceleration in peptide dynamics, which leads to the increased population of structures with fibril-inhibiting characteristics, such as the separated N- and C-termini and colocation of the aromatic residues at the same peptide face. In contrast, lower field strengths (<0.004 V/nm) promote the formation of the amyloid-prone hairpin structures relative to the ambient conditions. These findings suggest that intermediate-strength electromagnetic fields could be considered for designing alternative treatments of amyloid diseases, while the very high and low field strengths could be employed for engineering well-ordered fibrillar aggregates for non-medicinal applications.

A few categories of electromagnetic field problems treated through Fuzzy Logic

NASA Astrophysics Data System (ADS)

Lolea, M. S.; Dzitac, S.

2018-01-01

The paper deals with the problems of fuzzy logic applied in the field of electromagnetism. In the first part, there are presented some theoretical aspects regarding the characteristics and the application of the fuzzy logic in the general case. Are presented then, some categories of electromagnetic field problems treated by fuzzy logic. The accent is on the effects of exposure to the electromagnetic field on the human body. For this approach is dedicated a paragraph at the end of the paper. There is an application on how to treat by fuzzy logic the effects of electric field exposure. For this purpose, the fuzzy toolbox existing in the Matlab software and the results of some electric field strength measurements into a power substation are used. The results of the study and its conclusions are analyzed and exposed at the end of the paper.

Radio Frequency Electromagnetic Radiation From Streamer Collisions

NASA Astrophysics Data System (ADS)

Luque, Alejandro

2017-10-01

We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer collisions emit electromagnetic pulses that, at atmospheric pressure, dominate the radio frequency spectrum of an extended corona in the range from about 100 MHz to a few gigahertz. We also investigate the fast penetration, after a collision, of electromagnetic fields into the streamer heads and show that these fields are capable of accelerating electrons up to about 100 keV. By substantiating the link between X-rays and high-frequency radio emissions and by describing a mechanism for the early acceleration of runaway electrons, our results support the hypothesis that streamer collisions are essential precursors of high-energy processes in electric discharges.

Radio Frequency Electromagnetic Radiation From Streamer Collisions.

PubMed

Luque, Alejandro

2017-10-16

We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer collisions emit electromagnetic pulses that, at atmospheric pressure, dominate the radio frequency spectrum of an extended corona in the range from about 100 MHz to a few gigahertz. We also investigate the fast penetration, after a collision, of electromagnetic fields into the streamer heads and show that these fields are capable of accelerating electrons up to about 100 keV. By substantiating the link between X-rays and high-frequency radio emissions and by describing a mechanism for the early acceleration of runaway electrons, our results support the hypothesis that streamer collisions are essential precursors of high-energy processes in electric discharges.

Airborne electromagnetic data and processing within Leach Lake Basin, Fort Irwin, California: Chapter G in Geology and geophysics applied to groundwater hydrology at Fort Irwin, California

USGS Publications Warehouse

Bedrosian, Paul A.; Ball, Lyndsay B.; Bloss, Benjamin R.; Buesch, David C.

2014-01-01

From December 2010 to January 2011, the U.S. Geological Survey conducted airborne electromagnetic and magnetic surveys of Leach Lake Basin within the National Training Center, Fort Irwin, California. These data were collected to characterize the subsurface and provide information needed to understand and manage groundwater resources within Fort Irwin. A resistivity stratigraphy was developed using ground-based time-domain electromagnetic soundings together with laboratory resistivity measurements on hand samples and borehole geophysical logs from nearby basins. This report releases data associated with the airborne surveys, as well as resistivity cross-sections and depth slices derived from inversion of the airborne electromagnetic data. The resulting resistivity models confirm and add to the geologic framework, constrain the hydrostratigraphy and the depth to basement, and reveal the distribution of faults and folds within the basin.

Systems and methods for locating and imaging proppant in an induced fracture

DOEpatents

Aldridge, David F.; Bartel, Lewis C.

2016-02-02

Born Scattering Inversion (BSI) systems and methods are disclosed. A BSI system may be incorporated in a well system for accessing natural gas, oil and geothermal reserves in a geologic formation beneath the surface of the Earth. The BSI system may be used to generate a three-dimensional image of a proppant-filled hydraulically-induced fracture in the geologic formation. The BSI system may include computing equipment and sensors for measuring electromagnetic fields in the vicinity of the fracture before and after the fracture is generated, adjusting the parameters of a first Born approximation model of a scattered component of the surface electromagnetic fields using the measured electromagnetic fields, and generating the image of the proppant-filled fracture using the adjusted parameters.

Cavity detection and delineation research. Report 5: Electromagnetic (Radar) techniques applied to cavity detection

NASA Astrophysics Data System (ADS)

Ballard, R. F., Jr.

1983-07-01

This study evaluated four different radar systems to determine their effectiveness in locating subterranean cavities. Tests were conducted at three well-documented sites: Vicksburg, Miss.; Medford Cave, Fla. (near Ocala); and Manatee Springs, Fla. (near Chiefland). None of the radar systems was effective at the Vicksburg, Miss., site because of extremely high conductivities encountered in the overburden materials which were comprised primarily of silts (loess) and clays. The following radar systems were used in this study: (a) A pulsed system fabricated and operated by personnel from Texas A/M University; (b) A pulsed system commercially manufactured by GSSI operated by the owners, Technos, Inc.; (c) A pulsed system developed, fabricated, and operated by personnel from SwRI; and (d) A continuous wave system development, fabricated and operated by personnel from LLNL.

Electromagnetically induced transparency and Autler-Townes splitting in superconducting flux quantum circuits

NASA Astrophysics Data System (ADS)

Sun, Hui-Chen; Liu, Yu-xi; Ian, Hou; You, J. Q.; Il'ichev, E.; Nori, Franco

2014-06-01

We study the microwave absorption of a driven three-level quantum system, which is realized by a superconducting flux quantum circuit (SFQC), with a magnetic driving field applied to the two upper levels. The interaction between the three-level system and its environment is studied within the Born-Markov approximation, and we take into account the effects of the driving field on the damping rates of the three-level system. We study the linear response of the driven three-level SFQC to a weak probe field. The linear magnetic susceptibility of the SFQC can be changed by both the driving field and the bias magnetic flux. When the bias magnetic flux is at the optimal point, the transition from the ground state to the second-excited state is forbidden and the three-level SFQC has a ladder-type transition. Thus, the SFQC responds to the probe field like natural atoms with ladder-type transitions. However, when the bias magnetic flux deviates from the optimal point, the three-level SFQC has a cyclic transition, thus it responds to the probe field like a combination of natural atoms with ladder-type transitions and natural atoms with Λ-type transitions. In particular, we provide detailed discussions on the conditions for realizing electromagnetically induced transparency and Autler-Townes splitting in three-level SFQCs.

Research of an electromagnetically actuated spark gap switch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Tianyang; Chen, Dongqun, E-mail: csycdq@163.com; Liu, Jinliang

2013-11-15

As an important part of pulsed power systems, high-voltage and high-current triggered spark gap switch and its trigger system are expected to achieve a compact structure. In this paper, a high-voltage, high-current, and compact electromagnetically actuated spark gap switch is put forward, and it can be applied as a part of an intense electron-beam accelerator (IEBA). A 24 V DC power supply is used to trigger the switch. The characteristics of the switch were measured for N{sub 2} when the gas pressure is 0.10–0.30 MPa. The experimental results showed that the voltage/pressure (V/p) curve of the switch was linear relationship.more » The operating ranges of the switch were 21%–96%, 21%–95%, 21%–95%, 19%–95%, 17%–95%, and 16%–96% of the switch's self-breakdown voltage when the gas pressures were 0.10, 0.14, 0.18, 0.22, 0.26, and 0.30 MPa, respectively. The switch and its trigger system worked steadily and reliably with a peak voltage of 30 kV, a peak current of 60 kA in the IEBA when the pressure of N{sub 2} in the switch was 0.30 MPa.« less

Quantum and classical dissipation of charged particles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ibarra-Sierra, V.G.; Anzaldo-Meneses, A.; Cardoso, J.L.

2013-08-15

A Hamiltonian approach is presented to study the two dimensional motion of damped electric charges in time dependent electromagnetic fields. The classical and the corresponding quantum mechanical problems are solved for particular cases using canonical transformations applied to Hamiltonians for a particle with variable mass. Green’s function is constructed and, from it, the motion of a Gaussian wave packet is studied in detail. -- Highlights: •Hamiltonian of a damped charged particle in time dependent electromagnetic fields. •Exact Green’s function of a charged particle in time dependent electromagnetic fields. •Time evolution of a Gaussian wave packet of a damped charged particle.more » •Classical and quantum dynamics of a damped electric charge.« less

Application of NASTRAN to TFTR toroidal field coil structures

NASA Technical Reports Server (NTRS)

Chen, S. J.; Lee, E.

1978-01-01

The primary applied loads on the TF coils were electromagnetic and thermal. The complex structure and the tremendous applied loads necessitated computer type of solutions for the design problems. In the early stage of the TF coil design, many simplified finite element models were developed for the purpose of investigating the effects of material properties, supporting schemes, and coil case material on the stress levels in the case and in the copper coil. In the more sophisticated models that followed the parametric and scoping studies, the isoparametric elements, such as QUAD4, HEX8, and HEXA, were used. The analysis results from using these finite element models and the NASTRAN system were considered accurate enough to provide timely design information.

Pre-processing of data coming from a laser-EMAT system for non-destructive testing of steel slabs.

PubMed

Sgarbi, Mirko; Colla, Valentina; Cateni, Sivia; Higson, Stuart

2012-01-01

Non destructive test systems are increasingly applied in the industrial context for their strong potentialities in improving and standardizing quality control. Especially in the intermediate manufacturing stages, early detection of defects on semi-finished products allow their direction towards later production processes according to their quality, with consequent considerable savings in time, energy, materials and work. However, the raw data coming from non destructive test systems are not always immediately suitable for sophisticated defect detection algorithms, due to noise and disturbances which are unavoidable, especially in harsh operating conditions, such as the ones which are typical of the steelmaking cycle. The paper describes some pre-processing operations which are required in order to exploit the data coming from a non destructive test system. Such a system is based on the joint exploitation of Laser and Electro-Magnetic Acoustic Transducer technologies and is applied to the detection of surface and sub-surface cracks in cold and hot steel slabs. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Manipulating ion-atom collisions with coherent electromagnetic radiation.

PubMed

Kirchner, Tom

2002-08-26

Laser-assisted ion-atom collisions are considered in terms of a nonperturbative quantum mechanical description of the electronic motion. It is shown for the system He(2+) - H at 2 keV/amu that the collision dynamics depend strongly on the initial phase of the laser field and the applied wavelength. Whereas electronic transitions are caused by the concurrent action of the field and the projectile ion at relatively low frequencies, they can be separated into modified collisional capture and field ionization events in the region above the one-photon ionization threshold.

Microwave-Assisted Extraction of Fucoidan from Marine Algae.

PubMed

Mussatto, Solange I

2015-01-01

Microwave-assisted extraction (MAE) is a technique that can be applied to extract compounds from different natural resources. In this chapter, the use of this technique to extract fucoidan from marine algae is described. The method involves a closed MAE system, ultrapure water as extraction solvent, and suitable conditions of time, pressure, and algal biomass/water ratio. By using this procedure under the specified conditions, the penetration of the electromagnetic waves into the material structure occurs in an efficient manner, generating a distributed heat source that promotes the fucoidan extraction from the algal biomass.

[Combined application of balneotherapy to the medical rehabilitation of patients with seronegative spondyloarthrites].

PubMed

Barnatskiĭ, V V

2008-01-01

A rehabilitative complex combining radon baths and ultra-high frequency electromagnetic fields exerted a well-apparent beneficial effect on the clinical picture of articular and vertebral syndromes and greatly contributed to the correction of disturbances in the immune system of patients with seronegative spondyloarthritis. At the same time, combination of radon baths with low-frequency ultrasound treatment and hydrocortisone ultraphonophoresis reduced clinical activity of the disease, improved the patients' immune status, and had more prominent general anti-inflammatory action than the same physical factors applied as monotherapy.

Phase-sensitive atomic dynamics in quantum light

NASA Astrophysics Data System (ADS)

Balybin, S. N.; Zakharov, R. V.; Tikhonova, O. V.

2018-05-01

Interaction between a quantum electromagnetic field and a model Ry atom with possible transitions to the continuum and to the low-lying resonant state is investigated. Strong sensitivity of atomic dynamics to the phase of applied coherent and squeezed vacuum light is found. Methods to extract the quantum field phase performing the measurements on the atomic system are proposed. In the case of the few-photon coherent state high accuracy of the phase determination is demonstrated, which appears to be much higher in comparison to the usually used quantum-optical methods such as homodyne detection.

Proceedings of the Joint Conference on Magnetism and Magnetic Materials (6th) Held at Albuquerque, New Mexico on 20-23 June 1994. (Journal of Applied Physics. Volume 76, Number 10, Part 2)

DTIC Science & Technology

1994-06-23

4728 Levitation, Propulsion, and Power and Control Magnetics Optimal Design of the Electromagnetic Levitation with Permanent and Electro Magnets-Y-K...Germany M. Richter and H. Eschrig MGP Research Group "Electron Systems," Technical University Dresden, D-01062 Dresden, Germany Magnetic and specific... designed to achieve the desired 6M. G. Abele, Tenth International Workshop on Rare-Earth Magnets and field configuration. The ability to control the

Electromagnet Weight Reduction in a Magnetic Levitation System for Contactless Delivery Applications

PubMed Central

Hong, Do-Kwan; Woo, Byung-Chul; Koo, Dae-Hyun; Lee, Ki-Chang

2010-01-01

This paper presents an optimum design of a lightweight vehicle levitation electromagnet, which also provides a passive guide force in a magnetic levitation system for contactless delivery applications. The split alignment of C-shaped electromagnets about C-shaped rails has a bad effect on the lateral deviation force, therefore, no-split positioning of electromagnets is better for lateral performance. This is verified by simulations and experiments. This paper presents a statistically optimized design with a high number of the design variables to reduce the weight of the electromagnet under the constraint of normal force using response surface methodology (RSM) and the kriging interpolation method. 2D and 3D magnetostatic analysis of the electromagnet are performed using ANSYS. The most effective design variables are extracted by a Pareto chart. The most desirable set is determined and the influence of each design variable on the objective function can be obtained. The generalized reduced gradient (GRG) algorithm is adopted in the kriging model. This paper’s procedure is validated by a comparison between experimental and calculation results, which shows that the predicted performance of the electromagnet designed by RSM is in good agreement with the simulation results. PMID:22163572

Module Eight: Induction; Basic Electricity and Electronics Individualized Learning System.

ERIC Educational Resources Information Center

Bureau of Naval Personnel, Washington, DC.

The module covers in greater depth electromagnetic induction, its effects, and how it is used to advantage in electrical circuits; and the physical components, called inductors, designed to take advantage of the phenomenon of electromagnetic induction. This module is divided into four lessons: electromagnetism; inductors and flux density, inducing…

Introducing Electromagnetic Field Momentum

ERIC Educational Resources Information Center

Hu, Ben Yu-Kuang

2012-01-01

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

77 FR 64935 - Reliability Standards for Geomagnetic Disturbances

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-24

... Ridge Study'') on the effects of electromagnetic pulses on the Bulk-Power System. Available at http... . \\6\\ Oak Ridge National Laboratory, Electromagnetic Pulse: Effects on the U.S. Power Grid: Meta-R-319... issued reports assessing the threat to the United States from Electromagnetic Pulse (EMP) attack in 2004...

Validating electromagnetic walking stick rail surface crack measuring systems : final report.

DOT National Transportation Integrated Search

2016-06-01

A series of field studies were undertaken to evaluate electromagnetic walking stick systems and their ability to measure the depth : of damage from surface breaking cracks. In total, four railroads, and four suppliers participated in the project. The...

Electromagnetic Analysis of ITER Diagnostic Equatorial Port Plugs During Plasma Disruptions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Y. Zhai, R. Feder, A. Brooks, M. Ulrickson, C.S. Pitcher and G.D. Loesser

2012-08-27

ITER diagnostic port plugs perform many functionsincluding structural support of diagnostic systems under high electromagnetic loads while allowing for diagnostic access to the plasma. The design of diagnostic equatorial port plugs (EPP) are largely driven by electromagnetic loads and associate responses of EPP structure during plasma disruptions and VDEs. This paper summarizes results of transient electromagnetic analysis using Opera 3d in support of the design activities for ITER diagnostic EPP. A complete distribution of disruption loads on the Diagnostic First Walls (DFWs), Diagnostic Shield Modules (DSMs) and the EPP structure, as well as impact on the system design integration duemore » to electrical contact among various EPP structural components are discussed.« less

Electromagnetic malfunction of semiconductor-type electronic personal dosimeters caused by access control systems for radiation facilities.

PubMed

Deji, Shizuhiko; Ito, Shigeki; Ariga, Eiji; Mori, Kazuyuki; Hirota, Masahiro; Saze, Takuya; Nishizawa, Kunihide

2006-08-01

High frequency electromagnetic fields in the 120 kHz band emitted from card readers for access control systems in radiation control areas cause abnormally high and erroneous indicated dose readings on semiconductor-type electronic personal dosimeters (SEPDs). All SEPDs malfunctioned but recovered their normal performance by resetting after the exposure ceased. The minimum distances required to prevent electromagnetic interference varied from 5.0 to 38.0 cm. The electric and magnetic immunity levels ranged from 35.1 to 267.6 V m(-1) and from 1.0 to 16.6 A m(-1), respectively. Electromagnetic immunity levels of SEPDs should be strengthened from the standpoint of radiation protection.

Lecture Series on Electromagnetic Interference and Electromagnetic Compatibility Presented on 10-11 June 1991 in Kjeller, Norway, 13-14 June 1991 in Konigswinter, Germany and 17-18 June 1991 in Lisbon, Portugal.

DTIC Science & Technology

1991-06-01

assessing EMC characteristics of EM systems in a lecture on "Measuremazzenvironments and testing".The various test en - vronments available will be described...severe in a dual-diversity system gains at least 10 dB in SNR relative to a maritime situation where salt water corrosion has for many non-diversity...environment having great significance for NATO systems are: (a) electromagnetic interference (EMT) arising from both natural and man-made sources; (b

Three-dimensional analysis of the surface registration accuracy of electromagnetic navigation systems in live endoscopic sinus surgery.

PubMed

Chang, C M; Fang, K M; Huang, T W; Wang, C T; Cheng, P W

2013-12-01

Studies on the performance of surface registration with electromagnetic tracking systems are lacking in both live surgery and the laboratory setting. This study presents the efficiency in time of the system preparation as well as the navigational accuracy of surface registration using electromagnetic tracking systems. Forty patients with bilateral chronic paranasal pansinusitis underwent endoscopic sinus surgery after undergoing sinus computed tomography scans. The surgeries were performed under electromagnetic navigation guidance after the surface registration had been carried out on all of the patients. The intraoperative measurements indicate the time taken for equipment set-up, surface registration and surgical procedure, as well as the degree of navigation error along 3 axes. The time taken for equipment set-up, surface registration and the surgical procedure was 179 +- 23 seconds, 39 +- 4.8 seconds and 114 +- 36 minutes, respectively. A comparison of the navigation error along the 3 axes showed that the deviation in the medial-lateral direction was significantly less than that in the anterior-posterior and cranial-caudal directions. The procedures of equipment set-up and surface registration in electromagnetic navigation tracking are efficient, convenient and easy to manipulate. The system accuracy is within the acceptable ranges, especially on the medial-lateral axis.

Electromagnetic structure of the proton within the CP-violation hypothesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krutov, A. F., E-mail: krutov@ssu.samara.ru; Kudinov, M. Yu., E-mail: kudinov@ssu.samara.ru

2013-11-15

The so-called non-Rosenbluth behavior of the proton electromagnetic form factors can be explained within the hypothesis of CP violation in electromagnetic processes involving composite systems of strongly interacting particles. It is shown that this hypothesis leads to the appearance of an additional, anapole, form factor of the proton. The proton electromagnetic form factors, including the anapole form factor, are estimated on the basis of experimental data on elastic electron-proton scattering.

A new method for motion capture of the scapula using an optoelectronic tracking device: a feasibility study.

PubMed

Šenk, Miroslav; Chèze, Laurence

2010-06-01

Optoelectronic tracking systems are rarely used in 3D studies examining shoulder movements including the scapula. Among the reasons is the important slippage of skin markers with respect to scapula. Methods using electromagnetic tracking devices are validated and frequently applied. Thus, the aim of this study was to develop a new method for in vivo optoelectronic scapular capture dealing with the accepted accuracy issues of validated methods. Eleven arm positions in three anatomical planes were examined using five subjects in static mode. The method was based on local optimisation, and recalculation procedures were made using a set of five scapular surface markers. The scapular rotations derived from the recalculation-based method yielded RMS errors comparable with the frequently used electromagnetic scapular methods (RMS up to 12.6° for 150° arm elevation). The results indicate that the present method can be used under careful considerations for 3D kinematical studies examining different shoulder movements.

Particle-In-Cell simulation concerning heat-flux mitigation using electromagnetic fields

NASA Astrophysics Data System (ADS)

Lüskow, Karl Felix; Duras, Julia; Kemnitz, Stefan; Kahnfeld, Daniel; Matthias, Paul; Bandelow, Gunnas; Schneider, Ralf; Konigorski, Detlev

2016-10-01

In space missions enormous amount of money is spent for the thermal protection system for re-entry. To avoid complex materials and save money one idea is to reduce the heat-flux towards the spacecraft. The partially-ionized gas can be controlled by electromagnetic fields. For first-principle tests partially ionized argon flow from an arc-jet was used to measure the heat-flux mitigation created by an external magnetic field. In the successful experiment a reduction of 85% was measured. In this work the Particle-in-Cell (PIC) method was used to simulate this experiment. PIC is able to reproduce the heat flux mitigation qualitatively. The main mechanism is identified as a changed electron transport and by this, modified electron density due to the reaction to the applied magnetic field. Ions follow due to quasi-neutrality and influence then strongly by charge exchange collisions the neutrals dynamics and heat deposition. This work was supported by the German Space Agency DLR through Project 50RS1508.

Characterization of biofilm formation in natural water subjected to low-frequency electromagnetic fields.

PubMed

Mercier, Anne; Bertaux, Joanne; Lesobre, Jérôme; Gravouil, Kevin; Verdon, Julien; Imbert, Christine; Valette, Eric; Héchard, Yann

2016-01-01

Electromagnetic field (EMF) treatment has proven to be effective against mineral scaling in water systems. Therefore, it should be assessed for the treatment of other deposits such as biofilms. In this study, a commercial device producing low-frequency EMF (1-10 kHz) was applied to a reactor fed with natural water for 45 days. The treatment promoted the concentration of microorganisms in suspension and limited the amount of sessile microorganisms in the biofilm, as determined by the measurement of total DNA, qPCR and microscopy. The structure of the bacterial community was assessed by t-RFLP and pyrosequencing analysis. The results showed that EMF treatment affected both planktonic and sessile community composition. EMFs were responsible for a shift in classes of Proteobacteria during development of the biofilm. It may be speculated that the EMF treatment affected particle solubility and/or microorganism hydration. This study indicated that EMFs modulated biofilm formation in natural water.

Rigorous electromagnetic simulation applied to alignment systems

NASA Astrophysics Data System (ADS)

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

2001-09-01

Rigorous electromagnetic simulation with TEMPEST is used to provide benchmark data and understanding of key parameters in the design of topographical features of alignment marks. Periodic large silicon trenches are analyzed as a function of wavelength (530-800 nm), duty cycle, depth, slope and angle of incidence. The signals are well behaved except when the trench width becomes about 1 micrometers or smaller. Segmentation of the trenches to form 3D marks shows that a segmentation period of 2-5 wavelengths makes the diffraction in the (1,1) direction about 1/3 to 1/2 of that in the main first order (1,0). Transmission alignment marks nanoimprint lithography using the difference between the +1 and -1 reflected orders showed a sensitivity of the difference signal to misalignment of 0.7%/nm for rigorous simulation and 0.5%/nm for simple ray-tracing. The sensitivity to a slanted substrate indentation was 10 nm off-set per degree of tilt from horizontal.

High power microwave hazard facing smart ammunitions

NASA Astrophysics Data System (ADS)

Bohl, J.

1995-03-01

The battle field of the present and even more the one in future will be characterized by the use of weapon systems with a high degree of electronics, computers, and sensors, designed and built to keep not only the man out of the loop. But the higher the technology used for smart weapon systems, the more these systems are endangered by numerous sources of hazard. One of those sources is the threat caused by induced or natural electromagnetic fields. These threat factors can be generated by natural, civil and military environment. In principle there are two main applications which must be considered in military applications: Firstly, weapon systems, that is, high power microwave sources as well as intelligent electromagnetic radiation systems to defeat ammunition on the battle field and secondly, the hardening of the own smart ammunition systems and missiles against the interference sources created by the different types of electromagnetic fields. This report will discuss the possible electromagnetic coupling effects on smart ammunition and missiles and their typical interference caused on the electronics and sensor level. Real time 6-DOF simulations show the flight mission which may be compromised depending on the coupled electromagnetic fields. The German MOD has established a research program where smart ammunitions with different seeker systems are investigated in respect of the coupling effects on smart ammunition caused by high power microwaves. This program considers all available resources and know how in Germany. The systems are investigated by analytical, numerical, and experimental methods with passive and activated missiles.

Prediction and measurement of the electromagnetic environment of high-power medium-wave and short-wave broadcast antennas in far field.

PubMed

Tang, Zhanghong; Wang, Qun; Ji, Zhijiang; Shi, Meiwu; Hou, Guoyan; Tan, Danjun; Wang, Pengqi; Qiu, Xianbo

2014-12-01

With the increasing city size, high-power electromagnetic radiation devices such as high-power medium-wave (MW) and short-wave (SW) antennas have been inevitably getting closer and closer to buildings, which resulted in the pollution of indoor electromagnetic radiation becoming worsened. To avoid such radiation exceeding the exposure limits by national standards, it is necessary to predict and survey the electromagnetic radiation by MW and SW antennas before constructing the buildings. In this paper, a modified prediction method for the far-field electromagnetic radiation is proposed and successfully applied to predict the electromagnetic environment of an area close to a group of typical high-power MW and SW wave antennas. Different from currently used simplified prediction method defined in the Radiation Protection Management Guidelines (H J/T 10. 3-1996), the new method in this article makes use of more information such as antennas' patterns to predict the electromagnetic environment. Therefore, it improves the prediction accuracy significantly by the new feature of resolution at different directions. At the end of this article, a comparison between the prediction data and the measured results is given to demonstrate the effectiveness of the proposed new method. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Electromagnetic perception and individual features of human beings.

PubMed

Lebedeva, N N; Kotrovskaya, T I

2001-01-01

An investigation was made of the individual reactions of human subjects exposed to electromagnetic fields. We performed the study on 86 volunteers separated into two groups. The first group was exposed to the electromagnetic field of infralow frequencies, whereas the second group was exposed to the electromagnetic field of extremely high frequencies. We found that the electromagnetic perception of human beings correlated with their individual features, such as EEG parameters, the critical frequency of flash merging, and the electric current sensitivity. Human subjects who had a high-quality perception of electromagnetic waves showed an optimal balance of cerebral processes, an excellent functional state of the central nervous system, and a good decision criterion.

Electromagnetically induced transparency in circuit quantum electrodynamics with nested polariton states

PubMed Central

Long, Junling; Ku, H. S.; Wu, Xian; Gu, Xiu; Lake, Russell E.; Bal, Mustafa; Liu, Yu-xi; Pappas, David P.

2018-01-01

Quantum networks will enable extraordinary capabilities for communicating and processing quantum information. These networks require a reliable means of storage, retrieval, and manipulation of quantum states at the network nodes. A node receives one or more coherent inputs and sends a conditional output to the next cascaded node in the network through a quantum channel. Here, we demonstrate this basic functionality by using the quantum interference mechanism of electromagnetically induced transparency in a transmon qubit coupled to a superconducting resonator. First, we apply a microwave bias, i.e., drive, to the the qubit–cavity system to prepare a Λ-type three-level system of polariton states. Second, we input two interchangeable microwave signals, i.e., a probe tone and a control tone, and observe that transmission of the probe tone is conditional upon the presence of the control tone that switches the state of the device with up to 99.73 % transmission extinction. Importantly, our EIT scheme uses all dipole allowed transitions. We infer high dark state preparation fidelities of > 99.39 % and negative group velocities of up to −0.52 ± 0.09 km/s based on our data. PMID:29543019

[Cell phone communication: hygienic characteristics, biological action, standardization (a review)].

PubMed

Gudina, M V; Volkotrub, L P

2010-01-01

The paper considers the topical issues concerning the functioning of the cellular communication system. It provides the hygienic characteristics of its individual elements. The factors influencing the size of an electromagnetic field generated by mobile phones are stated. Research data on the impact of electromagnetic radiation from a mobile phone on users' health are reviewed. The pivots of present-day Russian hygienic rating regarding the permissible exposures to nonionizing electromagnetic energy generated by the elements of the cellular communication system are identified.